xref: /illumos-gate/usr/src/uts/common/vm/seg_vn.c (revision 58bc78c7a7ad65c04aaa3ef379a396df23988691)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 /*
40  * VM - shared or copy-on-write from a vnode/anonymous memory.
41  */
42 
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <sys/t_lock.h>
46 #include <sys/errno.h>
47 #include <sys/systm.h>
48 #include <sys/mman.h>
49 #include <sys/debug.h>
50 #include <sys/cred.h>
51 #include <sys/vmsystm.h>
52 #include <sys/tuneable.h>
53 #include <sys/bitmap.h>
54 #include <sys/swap.h>
55 #include <sys/kmem.h>
56 #include <sys/sysmacros.h>
57 #include <sys/vtrace.h>
58 #include <sys/cmn_err.h>
59 #include <sys/callb.h>
60 #include <sys/vm.h>
61 #include <sys/dumphdr.h>
62 #include <sys/lgrp.h>
63 
64 #include <vm/hat.h>
65 #include <vm/as.h>
66 #include <vm/seg.h>
67 #include <vm/seg_vn.h>
68 #include <vm/pvn.h>
69 #include <vm/anon.h>
70 #include <vm/page.h>
71 #include <vm/vpage.h>
72 #include <sys/proc.h>
73 #include <sys/task.h>
74 #include <sys/project.h>
75 #include <sys/zone.h>
76 #include <sys/shm_impl.h>
77 /*
78  * Private seg op routines.
79  */
80 static int	segvn_dup(struct seg *seg, struct seg *newseg);
81 static int	segvn_unmap(struct seg *seg, caddr_t addr, size_t len);
82 static void	segvn_free(struct seg *seg);
83 static faultcode_t segvn_fault(struct hat *hat, struct seg *seg,
84 		    caddr_t addr, size_t len, enum fault_type type,
85 		    enum seg_rw rw);
86 static faultcode_t segvn_faulta(struct seg *seg, caddr_t addr);
87 static int	segvn_setprot(struct seg *seg, caddr_t addr,
88 		    size_t len, uint_t prot);
89 static int	segvn_checkprot(struct seg *seg, caddr_t addr,
90 		    size_t len, uint_t prot);
91 static int	segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta);
92 static size_t	segvn_swapout(struct seg *seg);
93 static int	segvn_sync(struct seg *seg, caddr_t addr, size_t len,
94 		    int attr, uint_t flags);
95 static size_t	segvn_incore(struct seg *seg, caddr_t addr, size_t len,
96 		    char *vec);
97 static int	segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
98 		    int attr, int op, ulong_t *lockmap, size_t pos);
99 static int	segvn_getprot(struct seg *seg, caddr_t addr, size_t len,
100 		    uint_t *protv);
101 static u_offset_t	segvn_getoffset(struct seg *seg, caddr_t addr);
102 static int	segvn_gettype(struct seg *seg, caddr_t addr);
103 static int	segvn_getvp(struct seg *seg, caddr_t addr,
104 		    struct vnode **vpp);
105 static int	segvn_advise(struct seg *seg, caddr_t addr, size_t len,
106 		    uint_t behav);
107 static void	segvn_dump(struct seg *seg);
108 static int	segvn_pagelock(struct seg *seg, caddr_t addr, size_t len,
109 		    struct page ***ppp, enum lock_type type, enum seg_rw rw);
110 static int	segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len,
111 		    uint_t szc);
112 static int	segvn_getmemid(struct seg *seg, caddr_t addr,
113 		    memid_t *memidp);
114 static lgrp_mem_policy_info_t	*segvn_getpolicy(struct seg *, caddr_t);
115 static int	segvn_capable(struct seg *seg, segcapability_t capable);
116 
117 struct	seg_ops segvn_ops = {
118 	segvn_dup,
119 	segvn_unmap,
120 	segvn_free,
121 	segvn_fault,
122 	segvn_faulta,
123 	segvn_setprot,
124 	segvn_checkprot,
125 	segvn_kluster,
126 	segvn_swapout,
127 	segvn_sync,
128 	segvn_incore,
129 	segvn_lockop,
130 	segvn_getprot,
131 	segvn_getoffset,
132 	segvn_gettype,
133 	segvn_getvp,
134 	segvn_advise,
135 	segvn_dump,
136 	segvn_pagelock,
137 	segvn_setpagesize,
138 	segvn_getmemid,
139 	segvn_getpolicy,
140 	segvn_capable,
141 };
142 
143 /*
144  * Common zfod structures, provided as a shorthand for others to use.
145  */
146 static segvn_crargs_t zfod_segvn_crargs =
147 	SEGVN_ZFOD_ARGS(PROT_ZFOD, PROT_ALL);
148 static segvn_crargs_t kzfod_segvn_crargs =
149 	SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_USER,
150 	PROT_ALL & ~PROT_USER);
151 static segvn_crargs_t stack_noexec_crargs =
152 	SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_EXEC, PROT_ALL);
153 
154 caddr_t	zfod_argsp = (caddr_t)&zfod_segvn_crargs;	/* user zfod argsp */
155 caddr_t	kzfod_argsp = (caddr_t)&kzfod_segvn_crargs;	/* kernel zfod argsp */
156 caddr_t	stack_exec_argsp = (caddr_t)&zfod_segvn_crargs;	/* executable stack */
157 caddr_t	stack_noexec_argsp = (caddr_t)&stack_noexec_crargs; /* noexec stack */
158 
159 #define	vpgtob(n)	((n) * sizeof (struct vpage))	/* For brevity */
160 
161 size_t	segvn_comb_thrshld = UINT_MAX;	/* patchable -- see 1196681 */
162 
163 size_t	segvn_pglock_comb_thrshld = (1UL << 16);	/* 64K */
164 size_t	segvn_pglock_comb_balign = (1UL << 16);		/* 64K */
165 uint_t	segvn_pglock_comb_bshift;
166 size_t	segvn_pglock_comb_palign;
167 
168 static int	segvn_concat(struct seg *, struct seg *, int);
169 static int	segvn_extend_prev(struct seg *, struct seg *,
170 		    struct segvn_crargs *, size_t);
171 static int	segvn_extend_next(struct seg *, struct seg *,
172 		    struct segvn_crargs *, size_t);
173 static void	segvn_softunlock(struct seg *, caddr_t, size_t, enum seg_rw);
174 static void	segvn_pagelist_rele(page_t **);
175 static void	segvn_setvnode_mpss(vnode_t *);
176 static void	segvn_relocate_pages(page_t **, page_t *);
177 static int	segvn_full_szcpages(page_t **, uint_t, int *, uint_t *);
178 static int	segvn_fill_vp_pages(struct segvn_data *, vnode_t *, u_offset_t,
179     uint_t, page_t **, page_t **, uint_t *, int *);
180 static faultcode_t segvn_fault_vnodepages(struct hat *, struct seg *, caddr_t,
181     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
182 static faultcode_t segvn_fault_anonpages(struct hat *, struct seg *, caddr_t,
183     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
184 static faultcode_t segvn_faultpage(struct hat *, struct seg *, caddr_t,
185     u_offset_t, struct vpage *, page_t **, uint_t,
186     enum fault_type, enum seg_rw, int);
187 static void	segvn_vpage(struct seg *);
188 static size_t	segvn_count_swap_by_vpages(struct seg *);
189 
190 static void segvn_purge(struct seg *seg);
191 static int segvn_reclaim(void *, caddr_t, size_t, struct page **,
192     enum seg_rw, int);
193 static int shamp_reclaim(void *, caddr_t, size_t, struct page **,
194     enum seg_rw, int);
195 
196 static int sameprot(struct seg *, caddr_t, size_t);
197 
198 static int segvn_demote_range(struct seg *, caddr_t, size_t, int, uint_t);
199 static int segvn_clrszc(struct seg *);
200 static struct seg *segvn_split_seg(struct seg *, caddr_t);
201 static int segvn_claim_pages(struct seg *, struct vpage *, u_offset_t,
202     ulong_t, uint_t);
203 
204 static void segvn_hat_rgn_unload_callback(caddr_t, caddr_t, caddr_t,
205     size_t, void *, u_offset_t);
206 
207 static struct kmem_cache *segvn_cache;
208 static struct kmem_cache **segvn_szc_cache;
209 
210 #ifdef VM_STATS
211 static struct segvnvmstats_str {
212 	ulong_t	fill_vp_pages[31];
213 	ulong_t fltvnpages[49];
214 	ulong_t	fullszcpages[10];
215 	ulong_t	relocatepages[3];
216 	ulong_t	fltanpages[17];
217 	ulong_t pagelock[2];
218 	ulong_t	demoterange[3];
219 } segvnvmstats;
220 #endif /* VM_STATS */
221 
222 #define	SDR_RANGE	1		/* demote entire range */
223 #define	SDR_END		2		/* demote non aligned ends only */
224 
225 #define	CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr) {	    \
226 		if ((len) != 0) { 		      	      		      \
227 			lpgaddr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);  \
228 			ASSERT(lpgaddr >= (seg)->s_base);	      	      \
229 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)((addr) +    \
230 			    (len)), pgsz);				      \
231 			ASSERT(lpgeaddr > lpgaddr);		      	      \
232 			ASSERT(lpgeaddr <= (seg)->s_base + (seg)->s_size);    \
233 		} else {					      	      \
234 			lpgeaddr = lpgaddr = (addr);	      		      \
235 		}							      \
236 	}
237 
238 /*ARGSUSED*/
239 static int
240 segvn_cache_constructor(void *buf, void *cdrarg, int kmflags)
241 {
242 	struct segvn_data *svd = buf;
243 
244 	rw_init(&svd->lock, NULL, RW_DEFAULT, NULL);
245 	mutex_init(&svd->segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
246 	svd->svn_trnext = svd->svn_trprev = NULL;
247 	return (0);
248 }
249 
250 /*ARGSUSED1*/
251 static void
252 segvn_cache_destructor(void *buf, void *cdrarg)
253 {
254 	struct segvn_data *svd = buf;
255 
256 	rw_destroy(&svd->lock);
257 	mutex_destroy(&svd->segfree_syncmtx);
258 }
259 
260 /*ARGSUSED*/
261 static int
262 svntr_cache_constructor(void *buf, void *cdrarg, int kmflags)
263 {
264 	bzero(buf, sizeof (svntr_t));
265 	return (0);
266 }
267 
268 /*
269  * Patching this variable to non-zero allows the system to run with
270  * stacks marked as "not executable".  It's a bit of a kludge, but is
271  * provided as a tweakable for platforms that export those ABIs
272  * (e.g. sparc V8) that have executable stacks enabled by default.
273  * There are also some restrictions for platforms that don't actually
274  * implement 'noexec' protections.
275  *
276  * Once enabled, the system is (therefore) unable to provide a fully
277  * ABI-compliant execution environment, though practically speaking,
278  * most everything works.  The exceptions are generally some interpreters
279  * and debuggers that create executable code on the stack and jump
280  * into it (without explicitly mprotecting the address range to include
281  * PROT_EXEC).
282  *
283  * One important class of applications that are disabled are those
284  * that have been transformed into malicious agents using one of the
285  * numerous "buffer overflow" attacks.  See 4007890.
286  */
287 int noexec_user_stack = 0;
288 int noexec_user_stack_log = 1;
289 
290 int segvn_lpg_disable = 0;
291 uint_t segvn_maxpgszc = 0;
292 
293 ulong_t segvn_vmpss_clrszc_cnt;
294 ulong_t segvn_vmpss_clrszc_err;
295 ulong_t segvn_fltvnpages_clrszc_cnt;
296 ulong_t segvn_fltvnpages_clrszc_err;
297 ulong_t segvn_setpgsz_align_err;
298 ulong_t segvn_setpgsz_anon_align_err;
299 ulong_t segvn_setpgsz_getattr_err;
300 ulong_t segvn_setpgsz_eof_err;
301 ulong_t segvn_faultvnmpss_align_err1;
302 ulong_t segvn_faultvnmpss_align_err2;
303 ulong_t segvn_faultvnmpss_align_err3;
304 ulong_t segvn_faultvnmpss_align_err4;
305 ulong_t segvn_faultvnmpss_align_err5;
306 ulong_t	segvn_vmpss_pageio_deadlk_err;
307 
308 int segvn_use_regions = 1;
309 
310 /*
311  * Segvn supports text replication optimization for NUMA platforms. Text
312  * replica's are represented by anon maps (amp). There's one amp per text file
313  * region per lgroup. A process chooses the amp for each of its text mappings
314  * based on the lgroup assignment of its main thread (t_tid = 1). All
315  * processes that want a replica on a particular lgroup for the same text file
316  * mapping share the same amp. amp's are looked up in svntr_hashtab hash table
317  * with vp,off,size,szc used as a key. Text replication segments are read only
318  * MAP_PRIVATE|MAP_TEXT segments that map vnode. Replication is achieved by
319  * forcing COW faults from vnode to amp and mapping amp pages instead of vnode
320  * pages. Replication amp is assigned to a segment when it gets its first
321  * pagefault. To handle main thread lgroup rehoming segvn_trasync_thread
322  * rechecks periodically if the process still maps an amp local to the main
323  * thread. If not async thread forces process to remap to an amp in the new
324  * home lgroup of the main thread. Current text replication implementation
325  * only provides the benefit to workloads that do most of their work in the
326  * main thread of a process or all the threads of a process run in the same
327  * lgroup. To extend text replication benefit to different types of
328  * multithreaded workloads further work would be needed in the hat layer to
329  * allow the same virtual address in the same hat to simultaneously map
330  * different physical addresses (i.e. page table replication would be needed
331  * for x86).
332  *
333  * amp pages are used instead of vnode pages as long as segment has a very
334  * simple life cycle.  It's created via segvn_create(), handles S_EXEC
335  * (S_READ) pagefaults and is fully unmapped.  If anything more complicated
336  * happens such as protection is changed, real COW fault happens, pagesize is
337  * changed, MC_LOCK is requested or segment is partially unmapped we turn off
338  * text replication by converting the segment back to vnode only segment
339  * (unmap segment's address range and set svd->amp to NULL).
340  *
341  * The original file can be changed after amp is inserted into
342  * svntr_hashtab. Processes that are launched after the file is already
343  * changed can't use the replica's created prior to the file change. To
344  * implement this functionality hash entries are timestamped. Replica's can
345  * only be used if current file modification time is the same as the timestamp
346  * saved when hash entry was created. However just timestamps alone are not
347  * sufficient to detect file modification via mmap(MAP_SHARED) mappings. We
348  * deal with file changes via MAP_SHARED mappings differently. When writable
349  * MAP_SHARED mappings are created to vnodes marked as executable we mark all
350  * existing replica's for this vnode as not usable for future text
351  * mappings. And we don't create new replica's for files that currently have
352  * potentially writable MAP_SHARED mappings (i.e. vn_is_mapped(V_WRITE) is
353  * true).
354  */
355 
356 #define	SEGVN_TEXTREPL_MAXBYTES_FACTOR	(20)
357 size_t	segvn_textrepl_max_bytes_factor = SEGVN_TEXTREPL_MAXBYTES_FACTOR;
358 
359 static ulong_t			svntr_hashtab_sz = 512;
360 static svntr_bucket_t		*svntr_hashtab = NULL;
361 static struct kmem_cache	*svntr_cache;
362 static svntr_stats_t		*segvn_textrepl_stats;
363 static ksema_t 			segvn_trasync_sem;
364 
365 int				segvn_disable_textrepl = 1;
366 size_t				textrepl_size_thresh = (size_t)-1;
367 size_t				segvn_textrepl_bytes = 0;
368 size_t				segvn_textrepl_max_bytes = 0;
369 clock_t				segvn_update_textrepl_interval = 0;
370 int				segvn_update_tr_time = 10;
371 int				segvn_disable_textrepl_update = 0;
372 
373 static void segvn_textrepl(struct seg *);
374 static void segvn_textunrepl(struct seg *, int);
375 static void segvn_inval_trcache(vnode_t *);
376 static void segvn_trasync_thread(void);
377 static void segvn_trupdate_wakeup(void *);
378 static void segvn_trupdate(void);
379 static void segvn_trupdate_seg(struct seg *, segvn_data_t *, svntr_t *,
380     ulong_t);
381 
382 /*
383  * Initialize segvn data structures
384  */
385 void
386 segvn_init(void)
387 {
388 	uint_t maxszc;
389 	uint_t szc;
390 	size_t pgsz;
391 
392 	segvn_cache = kmem_cache_create("segvn_cache",
393 	    sizeof (struct segvn_data), 0,
394 	    segvn_cache_constructor, segvn_cache_destructor, NULL,
395 	    NULL, NULL, 0);
396 
397 	if (segvn_lpg_disable == 0) {
398 		szc = maxszc = page_num_pagesizes() - 1;
399 		if (szc == 0) {
400 			segvn_lpg_disable = 1;
401 		}
402 		if (page_get_pagesize(0) != PAGESIZE) {
403 			panic("segvn_init: bad szc 0");
404 			/*NOTREACHED*/
405 		}
406 		while (szc != 0) {
407 			pgsz = page_get_pagesize(szc);
408 			if (pgsz <= PAGESIZE || !IS_P2ALIGNED(pgsz, pgsz)) {
409 				panic("segvn_init: bad szc %d", szc);
410 				/*NOTREACHED*/
411 			}
412 			szc--;
413 		}
414 		if (segvn_maxpgszc == 0 || segvn_maxpgszc > maxszc)
415 			segvn_maxpgszc = maxszc;
416 	}
417 
418 	if (segvn_maxpgszc) {
419 		segvn_szc_cache = (struct kmem_cache **)kmem_alloc(
420 		    (segvn_maxpgszc + 1) * sizeof (struct kmem_cache *),
421 		    KM_SLEEP);
422 	}
423 
424 	for (szc = 1; szc <= segvn_maxpgszc; szc++) {
425 		char	str[32];
426 
427 		(void) sprintf(str, "segvn_szc_cache%d", szc);
428 		segvn_szc_cache[szc] = kmem_cache_create(str,
429 		    page_get_pagecnt(szc) * sizeof (page_t *), 0,
430 		    NULL, NULL, NULL, NULL, NULL, KMC_NODEBUG);
431 	}
432 
433 
434 	if (segvn_use_regions && !hat_supported(HAT_SHARED_REGIONS, NULL))
435 		segvn_use_regions = 0;
436 
437 	/*
438 	 * For now shared regions and text replication segvn support
439 	 * are mutually exclusive. This is acceptable because
440 	 * currently significant benefit from text replication was
441 	 * only observed on AMD64 NUMA platforms (due to relatively
442 	 * small L2$ size) and currently we don't support shared
443 	 * regions on x86.
444 	 */
445 	if (segvn_use_regions && !segvn_disable_textrepl) {
446 		segvn_disable_textrepl = 1;
447 	}
448 
449 #if defined(_LP64)
450 	if (lgrp_optimizations() && textrepl_size_thresh != (size_t)-1 &&
451 	    !segvn_disable_textrepl) {
452 		ulong_t i;
453 		size_t hsz = svntr_hashtab_sz * sizeof (svntr_bucket_t);
454 
455 		svntr_cache = kmem_cache_create("svntr_cache",
456 		    sizeof (svntr_t), 0, svntr_cache_constructor, NULL,
457 		    NULL, NULL, NULL, 0);
458 		svntr_hashtab = kmem_zalloc(hsz, KM_SLEEP);
459 		for (i = 0; i < svntr_hashtab_sz; i++) {
460 			mutex_init(&svntr_hashtab[i].tr_lock,  NULL,
461 			    MUTEX_DEFAULT, NULL);
462 		}
463 		segvn_textrepl_max_bytes = ptob(physmem) /
464 		    segvn_textrepl_max_bytes_factor;
465 		segvn_textrepl_stats = kmem_zalloc(NCPU *
466 		    sizeof (svntr_stats_t), KM_SLEEP);
467 		sema_init(&segvn_trasync_sem, 0, NULL, SEMA_DEFAULT, NULL);
468 		(void) thread_create(NULL, 0, segvn_trasync_thread,
469 		    NULL, 0, &p0, TS_RUN, minclsyspri);
470 	}
471 #endif
472 
473 	if (!ISP2(segvn_pglock_comb_balign) ||
474 	    segvn_pglock_comb_balign < PAGESIZE) {
475 		segvn_pglock_comb_balign = 1UL << 16; /* 64K */
476 	}
477 	segvn_pglock_comb_bshift = highbit(segvn_pglock_comb_balign) - 1;
478 	segvn_pglock_comb_palign = btop(segvn_pglock_comb_balign);
479 }
480 
481 #define	SEGVN_PAGEIO	((void *)0x1)
482 #define	SEGVN_NOPAGEIO	((void *)0x2)
483 
484 static void
485 segvn_setvnode_mpss(vnode_t *vp)
486 {
487 	int err;
488 
489 	ASSERT(vp->v_mpssdata == NULL ||
490 	    vp->v_mpssdata == SEGVN_PAGEIO ||
491 	    vp->v_mpssdata == SEGVN_NOPAGEIO);
492 
493 	if (vp->v_mpssdata == NULL) {
494 		if (vn_vmpss_usepageio(vp)) {
495 			err = VOP_PAGEIO(vp, (page_t *)NULL,
496 			    (u_offset_t)0, 0, 0, CRED(), NULL);
497 		} else {
498 			err = ENOSYS;
499 		}
500 		/*
501 		 * set v_mpssdata just once per vnode life
502 		 * so that it never changes.
503 		 */
504 		mutex_enter(&vp->v_lock);
505 		if (vp->v_mpssdata == NULL) {
506 			if (err == EINVAL) {
507 				vp->v_mpssdata = SEGVN_PAGEIO;
508 			} else {
509 				vp->v_mpssdata = SEGVN_NOPAGEIO;
510 			}
511 		}
512 		mutex_exit(&vp->v_lock);
513 	}
514 }
515 
516 int
517 segvn_create(struct seg *seg, void *argsp)
518 {
519 	struct segvn_crargs *a = (struct segvn_crargs *)argsp;
520 	struct segvn_data *svd;
521 	size_t swresv = 0;
522 	struct cred *cred;
523 	struct anon_map *amp;
524 	int error = 0;
525 	size_t pgsz;
526 	lgrp_mem_policy_t mpolicy = LGRP_MEM_POLICY_DEFAULT;
527 	int use_rgn = 0;
528 	int trok = 0;
529 
530 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
531 
532 	if (a->type != MAP_PRIVATE && a->type != MAP_SHARED) {
533 		panic("segvn_create type");
534 		/*NOTREACHED*/
535 	}
536 
537 	/*
538 	 * Check arguments.  If a shared anon structure is given then
539 	 * it is illegal to also specify a vp.
540 	 */
541 	if (a->amp != NULL && a->vp != NULL) {
542 		panic("segvn_create anon_map");
543 		/*NOTREACHED*/
544 	}
545 
546 	if (a->type == MAP_PRIVATE && (a->flags & MAP_TEXT) &&
547 	    a->vp != NULL && a->prot == (PROT_USER | PROT_READ | PROT_EXEC) &&
548 	    segvn_use_regions) {
549 		use_rgn = 1;
550 	}
551 
552 	/* MAP_NORESERVE on a MAP_SHARED segment is meaningless. */
553 	if (a->type == MAP_SHARED)
554 		a->flags &= ~MAP_NORESERVE;
555 
556 	if (a->szc != 0) {
557 		if (segvn_lpg_disable != 0 || (a->szc == AS_MAP_NO_LPOOB) ||
558 		    (a->amp != NULL && a->type == MAP_PRIVATE) ||
559 		    (a->flags & MAP_NORESERVE) || seg->s_as == &kas) {
560 			a->szc = 0;
561 		} else {
562 			if (a->szc > segvn_maxpgszc)
563 				a->szc = segvn_maxpgszc;
564 			pgsz = page_get_pagesize(a->szc);
565 			if (!IS_P2ALIGNED(seg->s_base, pgsz) ||
566 			    !IS_P2ALIGNED(seg->s_size, pgsz)) {
567 				a->szc = 0;
568 			} else if (a->vp != NULL) {
569 				extern struct vnode kvp;
570 				if (IS_SWAPFSVP(a->vp) || VN_ISKAS(a->vp)) {
571 					/*
572 					 * paranoid check.
573 					 * hat_page_demote() is not supported
574 					 * on swapfs pages.
575 					 */
576 					a->szc = 0;
577 				} else if (map_addr_vacalign_check(seg->s_base,
578 				    a->offset & PAGEMASK)) {
579 					a->szc = 0;
580 				}
581 			} else if (a->amp != NULL) {
582 				pgcnt_t anum = btopr(a->offset);
583 				pgcnt_t pgcnt = page_get_pagecnt(a->szc);
584 				if (!IS_P2ALIGNED(anum, pgcnt)) {
585 					a->szc = 0;
586 				}
587 			}
588 		}
589 	}
590 
591 	/*
592 	 * If segment may need private pages, reserve them now.
593 	 */
594 	if (!(a->flags & MAP_NORESERVE) && ((a->vp == NULL && a->amp == NULL) ||
595 	    (a->type == MAP_PRIVATE && (a->prot & PROT_WRITE)))) {
596 		if (anon_resv_zone(seg->s_size,
597 		    seg->s_as->a_proc->p_zone) == 0)
598 			return (EAGAIN);
599 		swresv = seg->s_size;
600 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
601 		    seg, swresv, 1);
602 	}
603 
604 	/*
605 	 * Reserve any mapping structures that may be required.
606 	 *
607 	 * Don't do it for segments that may use regions. It's currently a
608 	 * noop in the hat implementations anyway.
609 	 */
610 	if (!use_rgn) {
611 		hat_map(seg->s_as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
612 	}
613 
614 	if (a->cred) {
615 		cred = a->cred;
616 		crhold(cred);
617 	} else {
618 		crhold(cred = CRED());
619 	}
620 
621 	/* Inform the vnode of the new mapping */
622 	if (a->vp != NULL) {
623 		error = VOP_ADDMAP(a->vp, a->offset & PAGEMASK,
624 		    seg->s_as, seg->s_base, seg->s_size, a->prot,
625 		    a->maxprot, a->type, cred, NULL);
626 		if (error) {
627 			if (swresv != 0) {
628 				anon_unresv_zone(swresv,
629 				    seg->s_as->a_proc->p_zone);
630 				TRACE_3(TR_FAC_VM, TR_ANON_PROC,
631 				    "anon proc:%p %lu %u", seg, swresv, 0);
632 			}
633 			crfree(cred);
634 			if (!use_rgn) {
635 				hat_unload(seg->s_as->a_hat, seg->s_base,
636 				    seg->s_size, HAT_UNLOAD_UNMAP);
637 			}
638 			return (error);
639 		}
640 		/*
641 		 * svntr_hashtab will be NULL if we support shared regions.
642 		 */
643 		trok = ((a->flags & MAP_TEXT) &&
644 		    (seg->s_size > textrepl_size_thresh ||
645 		    (a->flags & _MAP_TEXTREPL)) &&
646 		    lgrp_optimizations() && svntr_hashtab != NULL &&
647 		    a->type == MAP_PRIVATE && swresv == 0 &&
648 		    !(a->flags & MAP_NORESERVE) &&
649 		    seg->s_as != &kas && a->vp->v_type == VREG);
650 
651 		ASSERT(!trok || !use_rgn);
652 	}
653 
654 	/*
655 	 * If more than one segment in the address space, and they're adjacent
656 	 * virtually, try to concatenate them.  Don't concatenate if an
657 	 * explicit anon_map structure was supplied (e.g., SystemV shared
658 	 * memory) or if we'll use text replication for this segment.
659 	 */
660 	if (a->amp == NULL && !use_rgn && !trok) {
661 		struct seg *pseg, *nseg;
662 		struct segvn_data *psvd, *nsvd;
663 		lgrp_mem_policy_t ppolicy, npolicy;
664 		uint_t	lgrp_mem_policy_flags = 0;
665 		extern lgrp_mem_policy_t lgrp_mem_default_policy;
666 
667 		/*
668 		 * Memory policy flags (lgrp_mem_policy_flags) is valid when
669 		 * extending stack/heap segments.
670 		 */
671 		if ((a->vp == NULL) && (a->type == MAP_PRIVATE) &&
672 		    !(a->flags & MAP_NORESERVE) && (seg->s_as != &kas)) {
673 			lgrp_mem_policy_flags = a->lgrp_mem_policy_flags;
674 		} else {
675 			/*
676 			 * Get policy when not extending it from another segment
677 			 */
678 			mpolicy = lgrp_mem_policy_default(seg->s_size, a->type);
679 		}
680 
681 		/*
682 		 * First, try to concatenate the previous and new segments
683 		 */
684 		pseg = AS_SEGPREV(seg->s_as, seg);
685 		if (pseg != NULL &&
686 		    pseg->s_base + pseg->s_size == seg->s_base &&
687 		    pseg->s_ops == &segvn_ops) {
688 			/*
689 			 * Get memory allocation policy from previous segment.
690 			 * When extension is specified (e.g. for heap) apply
691 			 * this policy to the new segment regardless of the
692 			 * outcome of segment concatenation.  Extension occurs
693 			 * for non-default policy otherwise default policy is
694 			 * used and is based on extended segment size.
695 			 */
696 			psvd = (struct segvn_data *)pseg->s_data;
697 			ppolicy = psvd->policy_info.mem_policy;
698 			if (lgrp_mem_policy_flags ==
699 			    LGRP_MP_FLAG_EXTEND_UP) {
700 				if (ppolicy != lgrp_mem_default_policy) {
701 					mpolicy = ppolicy;
702 				} else {
703 					mpolicy = lgrp_mem_policy_default(
704 					    pseg->s_size + seg->s_size,
705 					    a->type);
706 				}
707 			}
708 
709 			if (mpolicy == ppolicy &&
710 			    (pseg->s_size + seg->s_size <=
711 			    segvn_comb_thrshld || psvd->amp == NULL) &&
712 			    segvn_extend_prev(pseg, seg, a, swresv) == 0) {
713 				/*
714 				 * success! now try to concatenate
715 				 * with following seg
716 				 */
717 				crfree(cred);
718 				nseg = AS_SEGNEXT(pseg->s_as, pseg);
719 				if (nseg != NULL &&
720 				    nseg != pseg &&
721 				    nseg->s_ops == &segvn_ops &&
722 				    pseg->s_base + pseg->s_size ==
723 				    nseg->s_base)
724 					(void) segvn_concat(pseg, nseg, 0);
725 				ASSERT(pseg->s_szc == 0 ||
726 				    (a->szc == pseg->s_szc &&
727 				    IS_P2ALIGNED(pseg->s_base, pgsz) &&
728 				    IS_P2ALIGNED(pseg->s_size, pgsz)));
729 				return (0);
730 			}
731 		}
732 
733 		/*
734 		 * Failed, so try to concatenate with following seg
735 		 */
736 		nseg = AS_SEGNEXT(seg->s_as, seg);
737 		if (nseg != NULL &&
738 		    seg->s_base + seg->s_size == nseg->s_base &&
739 		    nseg->s_ops == &segvn_ops) {
740 			/*
741 			 * Get memory allocation policy from next segment.
742 			 * When extension is specified (e.g. for stack) apply
743 			 * this policy to the new segment regardless of the
744 			 * outcome of segment concatenation.  Extension occurs
745 			 * for non-default policy otherwise default policy is
746 			 * used and is based on extended segment size.
747 			 */
748 			nsvd = (struct segvn_data *)nseg->s_data;
749 			npolicy = nsvd->policy_info.mem_policy;
750 			if (lgrp_mem_policy_flags ==
751 			    LGRP_MP_FLAG_EXTEND_DOWN) {
752 				if (npolicy != lgrp_mem_default_policy) {
753 					mpolicy = npolicy;
754 				} else {
755 					mpolicy = lgrp_mem_policy_default(
756 					    nseg->s_size + seg->s_size,
757 					    a->type);
758 				}
759 			}
760 
761 			if (mpolicy == npolicy &&
762 			    segvn_extend_next(seg, nseg, a, swresv) == 0) {
763 				crfree(cred);
764 				ASSERT(nseg->s_szc == 0 ||
765 				    (a->szc == nseg->s_szc &&
766 				    IS_P2ALIGNED(nseg->s_base, pgsz) &&
767 				    IS_P2ALIGNED(nseg->s_size, pgsz)));
768 				return (0);
769 			}
770 		}
771 	}
772 
773 	if (a->vp != NULL) {
774 		VN_HOLD(a->vp);
775 		if (a->type == MAP_SHARED)
776 			lgrp_shm_policy_init(NULL, a->vp);
777 	}
778 	svd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
779 
780 	seg->s_ops = &segvn_ops;
781 	seg->s_data = (void *)svd;
782 	seg->s_szc = a->szc;
783 
784 	svd->seg = seg;
785 	svd->vp = a->vp;
786 	/*
787 	 * Anonymous mappings have no backing file so the offset is meaningless.
788 	 */
789 	svd->offset = a->vp ? (a->offset & PAGEMASK) : 0;
790 	svd->prot = a->prot;
791 	svd->maxprot = a->maxprot;
792 	svd->pageprot = 0;
793 	svd->type = a->type;
794 	svd->vpage = NULL;
795 	svd->cred = cred;
796 	svd->advice = MADV_NORMAL;
797 	svd->pageadvice = 0;
798 	svd->flags = (ushort_t)a->flags;
799 	svd->softlockcnt = 0;
800 	svd->softlockcnt_sbase = 0;
801 	svd->softlockcnt_send = 0;
802 	svd->rcookie = HAT_INVALID_REGION_COOKIE;
803 	svd->pageswap = 0;
804 
805 	if (a->szc != 0 && a->vp != NULL) {
806 		segvn_setvnode_mpss(a->vp);
807 	}
808 	if (svd->type == MAP_SHARED && svd->vp != NULL &&
809 	    (svd->vp->v_flag & VVMEXEC) && (svd->prot & PROT_WRITE)) {
810 		ASSERT(vn_is_mapped(svd->vp, V_WRITE));
811 		segvn_inval_trcache(svd->vp);
812 	}
813 
814 	amp = a->amp;
815 	if ((svd->amp = amp) == NULL) {
816 		svd->anon_index = 0;
817 		if (svd->type == MAP_SHARED) {
818 			svd->swresv = 0;
819 			/*
820 			 * Shared mappings to a vp need no other setup.
821 			 * If we have a shared mapping to an anon_map object
822 			 * which hasn't been allocated yet,  allocate the
823 			 * struct now so that it will be properly shared
824 			 * by remembering the swap reservation there.
825 			 */
826 			if (a->vp == NULL) {
827 				svd->amp = anonmap_alloc(seg->s_size, swresv,
828 				    ANON_SLEEP);
829 				svd->amp->a_szc = seg->s_szc;
830 			}
831 		} else {
832 			/*
833 			 * Private mapping (with or without a vp).
834 			 * Allocate anon_map when needed.
835 			 */
836 			svd->swresv = swresv;
837 		}
838 	} else {
839 		pgcnt_t anon_num;
840 
841 		/*
842 		 * Mapping to an existing anon_map structure without a vp.
843 		 * For now we will insure that the segment size isn't larger
844 		 * than the size - offset gives us.  Later on we may wish to
845 		 * have the anon array dynamically allocated itself so that
846 		 * we don't always have to allocate all the anon pointer slots.
847 		 * This of course involves adding extra code to check that we
848 		 * aren't trying to use an anon pointer slot beyond the end
849 		 * of the currently allocated anon array.
850 		 */
851 		if ((amp->size - a->offset) < seg->s_size) {
852 			panic("segvn_create anon_map size");
853 			/*NOTREACHED*/
854 		}
855 
856 		anon_num = btopr(a->offset);
857 
858 		if (a->type == MAP_SHARED) {
859 			/*
860 			 * SHARED mapping to a given anon_map.
861 			 */
862 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
863 			amp->refcnt++;
864 			if (a->szc > amp->a_szc) {
865 				amp->a_szc = a->szc;
866 			}
867 			ANON_LOCK_EXIT(&amp->a_rwlock);
868 			svd->anon_index = anon_num;
869 			svd->swresv = 0;
870 		} else {
871 			/*
872 			 * PRIVATE mapping to a given anon_map.
873 			 * Make sure that all the needed anon
874 			 * structures are created (so that we will
875 			 * share the underlying pages if nothing
876 			 * is written by this mapping) and then
877 			 * duplicate the anon array as is done
878 			 * when a privately mapped segment is dup'ed.
879 			 */
880 			struct anon *ap;
881 			caddr_t addr;
882 			caddr_t eaddr;
883 			ulong_t	anon_idx;
884 			int hat_flag = HAT_LOAD;
885 
886 			if (svd->flags & MAP_TEXT) {
887 				hat_flag |= HAT_LOAD_TEXT;
888 			}
889 
890 			svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
891 			svd->amp->a_szc = seg->s_szc;
892 			svd->anon_index = 0;
893 			svd->swresv = swresv;
894 
895 			/*
896 			 * Prevent 2 threads from allocating anon
897 			 * slots simultaneously.
898 			 */
899 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
900 			eaddr = seg->s_base + seg->s_size;
901 
902 			for (anon_idx = anon_num, addr = seg->s_base;
903 			    addr < eaddr; addr += PAGESIZE, anon_idx++) {
904 				page_t *pp;
905 
906 				if ((ap = anon_get_ptr(amp->ahp,
907 				    anon_idx)) != NULL)
908 					continue;
909 
910 				/*
911 				 * Allocate the anon struct now.
912 				 * Might as well load up translation
913 				 * to the page while we're at it...
914 				 */
915 				pp = anon_zero(seg, addr, &ap, cred);
916 				if (ap == NULL || pp == NULL) {
917 					panic("segvn_create anon_zero");
918 					/*NOTREACHED*/
919 				}
920 
921 				/*
922 				 * Re-acquire the anon_map lock and
923 				 * initialize the anon array entry.
924 				 */
925 				ASSERT(anon_get_ptr(amp->ahp,
926 				    anon_idx) == NULL);
927 				(void) anon_set_ptr(amp->ahp, anon_idx, ap,
928 				    ANON_SLEEP);
929 
930 				ASSERT(seg->s_szc == 0);
931 				ASSERT(!IS_VMODSORT(pp->p_vnode));
932 
933 				ASSERT(use_rgn == 0);
934 				hat_memload(seg->s_as->a_hat, addr, pp,
935 				    svd->prot & ~PROT_WRITE, hat_flag);
936 
937 				page_unlock(pp);
938 			}
939 			ASSERT(seg->s_szc == 0);
940 			anon_dup(amp->ahp, anon_num, svd->amp->ahp,
941 			    0, seg->s_size);
942 			ANON_LOCK_EXIT(&amp->a_rwlock);
943 		}
944 	}
945 
946 	/*
947 	 * Set default memory allocation policy for segment
948 	 *
949 	 * Always set policy for private memory at least for initialization
950 	 * even if this is a shared memory segment
951 	 */
952 	(void) lgrp_privm_policy_set(mpolicy, &svd->policy_info, seg->s_size);
953 
954 	if (svd->type == MAP_SHARED)
955 		(void) lgrp_shm_policy_set(mpolicy, svd->amp, svd->anon_index,
956 		    svd->vp, svd->offset, seg->s_size);
957 
958 	if (use_rgn) {
959 		ASSERT(!trok);
960 		ASSERT(svd->amp == NULL);
961 		svd->rcookie = hat_join_region(seg->s_as->a_hat, seg->s_base,
962 		    seg->s_size, (void *)svd->vp, svd->offset, svd->prot,
963 		    (uchar_t)seg->s_szc, segvn_hat_rgn_unload_callback,
964 		    HAT_REGION_TEXT);
965 	}
966 
967 	ASSERT(!trok || !(svd->prot & PROT_WRITE));
968 	svd->tr_state = trok ? SEGVN_TR_INIT : SEGVN_TR_OFF;
969 
970 	return (0);
971 }
972 
973 /*
974  * Concatenate two existing segments, if possible.
975  * Return 0 on success, -1 if two segments are not compatible
976  * or -2 on memory allocation failure.
977  * If amp_cat == 1 then try and concat segments with anon maps
978  */
979 static int
980 segvn_concat(struct seg *seg1, struct seg *seg2, int amp_cat)
981 {
982 	struct segvn_data *svd1 = seg1->s_data;
983 	struct segvn_data *svd2 = seg2->s_data;
984 	struct anon_map *amp1 = svd1->amp;
985 	struct anon_map *amp2 = svd2->amp;
986 	struct vpage *vpage1 = svd1->vpage;
987 	struct vpage *vpage2 = svd2->vpage, *nvpage = NULL;
988 	size_t size, nvpsize;
989 	pgcnt_t npages1, npages2;
990 
991 	ASSERT(seg1->s_as && seg2->s_as && seg1->s_as == seg2->s_as);
992 	ASSERT(AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
993 	ASSERT(seg1->s_ops == seg2->s_ops);
994 
995 	if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie) ||
996 	    HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
997 		return (-1);
998 	}
999 
1000 	/* both segments exist, try to merge them */
1001 #define	incompat(x)	(svd1->x != svd2->x)
1002 	if (incompat(vp) || incompat(maxprot) ||
1003 	    (!svd1->pageadvice && !svd2->pageadvice && incompat(advice)) ||
1004 	    (!svd1->pageprot && !svd2->pageprot && incompat(prot)) ||
1005 	    incompat(type) || incompat(cred) || incompat(flags) ||
1006 	    seg1->s_szc != seg2->s_szc || incompat(policy_info.mem_policy) ||
1007 	    (svd2->softlockcnt > 0) || svd1->softlockcnt_send > 0)
1008 		return (-1);
1009 #undef incompat
1010 
1011 	/*
1012 	 * vp == NULL implies zfod, offset doesn't matter
1013 	 */
1014 	if (svd1->vp != NULL &&
1015 	    svd1->offset + seg1->s_size != svd2->offset) {
1016 		return (-1);
1017 	}
1018 
1019 	/*
1020 	 * Don't concatenate if either segment uses text replication.
1021 	 */
1022 	if (svd1->tr_state != SEGVN_TR_OFF || svd2->tr_state != SEGVN_TR_OFF) {
1023 		return (-1);
1024 	}
1025 
1026 	/*
1027 	 * Fail early if we're not supposed to concatenate
1028 	 * segments with non NULL amp.
1029 	 */
1030 	if (amp_cat == 0 && (amp1 != NULL || amp2 != NULL)) {
1031 		return (-1);
1032 	}
1033 
1034 	if (svd1->vp == NULL && svd1->type == MAP_SHARED) {
1035 		if (amp1 != amp2) {
1036 			return (-1);
1037 		}
1038 		if (amp1 != NULL && svd1->anon_index + btop(seg1->s_size) !=
1039 		    svd2->anon_index) {
1040 			return (-1);
1041 		}
1042 		ASSERT(amp1 == NULL || amp1->refcnt >= 2);
1043 	}
1044 
1045 	/*
1046 	 * If either seg has vpages, create a new merged vpage array.
1047 	 */
1048 	if (vpage1 != NULL || vpage2 != NULL) {
1049 		struct vpage *vp, *evp;
1050 
1051 		npages1 = seg_pages(seg1);
1052 		npages2 = seg_pages(seg2);
1053 		nvpsize = vpgtob(npages1 + npages2);
1054 
1055 		if ((nvpage = kmem_zalloc(nvpsize, KM_NOSLEEP)) == NULL) {
1056 			return (-2);
1057 		}
1058 
1059 		if (vpage1 != NULL) {
1060 			bcopy(vpage1, nvpage, vpgtob(npages1));
1061 		} else {
1062 			evp = nvpage + npages1;
1063 			for (vp = nvpage; vp < evp; vp++) {
1064 				VPP_SETPROT(vp, svd1->prot);
1065 				VPP_SETADVICE(vp, svd1->advice);
1066 			}
1067 		}
1068 
1069 		if (vpage2 != NULL) {
1070 			bcopy(vpage2, nvpage + npages1, vpgtob(npages2));
1071 		} else {
1072 			evp = nvpage + npages1 + npages2;
1073 			for (vp = nvpage + npages1; vp < evp; vp++) {
1074 				VPP_SETPROT(vp, svd2->prot);
1075 				VPP_SETADVICE(vp, svd2->advice);
1076 			}
1077 		}
1078 
1079 		if (svd2->pageswap && (!svd1->pageswap && svd1->swresv)) {
1080 			ASSERT(svd1->swresv == seg1->s_size);
1081 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1082 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1083 			evp = nvpage + npages1;
1084 			for (vp = nvpage; vp < evp; vp++) {
1085 				VPP_SETSWAPRES(vp);
1086 			}
1087 		}
1088 
1089 		if (svd1->pageswap && (!svd2->pageswap && svd2->swresv)) {
1090 			ASSERT(svd2->swresv == seg2->s_size);
1091 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1092 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1093 			vp = nvpage + npages1;
1094 			evp = vp + npages2;
1095 			for (; vp < evp; vp++) {
1096 				VPP_SETSWAPRES(vp);
1097 			}
1098 		}
1099 	}
1100 	ASSERT((vpage1 != NULL || vpage2 != NULL) ||
1101 	    (svd1->pageswap == 0 && svd2->pageswap == 0));
1102 
1103 	/*
1104 	 * If either segment has private pages, create a new merged anon
1105 	 * array. If mergeing shared anon segments just decrement anon map's
1106 	 * refcnt.
1107 	 */
1108 	if (amp1 != NULL && svd1->type == MAP_SHARED) {
1109 		ASSERT(amp1 == amp2 && svd1->vp == NULL);
1110 		ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1111 		ASSERT(amp1->refcnt >= 2);
1112 		amp1->refcnt--;
1113 		ANON_LOCK_EXIT(&amp1->a_rwlock);
1114 		svd2->amp = NULL;
1115 	} else if (amp1 != NULL || amp2 != NULL) {
1116 		struct anon_hdr *nahp;
1117 		struct anon_map *namp = NULL;
1118 		size_t asize;
1119 
1120 		ASSERT(svd1->type == MAP_PRIVATE);
1121 
1122 		asize = seg1->s_size + seg2->s_size;
1123 		if ((nahp = anon_create(btop(asize), ANON_NOSLEEP)) == NULL) {
1124 			if (nvpage != NULL) {
1125 				kmem_free(nvpage, nvpsize);
1126 			}
1127 			return (-2);
1128 		}
1129 		if (amp1 != NULL) {
1130 			/*
1131 			 * XXX anon rwlock is not really needed because
1132 			 * this is a private segment and we are writers.
1133 			 */
1134 			ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1135 			ASSERT(amp1->refcnt == 1);
1136 			if (anon_copy_ptr(amp1->ahp, svd1->anon_index,
1137 			    nahp, 0, btop(seg1->s_size), ANON_NOSLEEP)) {
1138 				anon_release(nahp, btop(asize));
1139 				ANON_LOCK_EXIT(&amp1->a_rwlock);
1140 				if (nvpage != NULL) {
1141 					kmem_free(nvpage, nvpsize);
1142 				}
1143 				return (-2);
1144 			}
1145 		}
1146 		if (amp2 != NULL) {
1147 			ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1148 			ASSERT(amp2->refcnt == 1);
1149 			if (anon_copy_ptr(amp2->ahp, svd2->anon_index,
1150 			    nahp, btop(seg1->s_size), btop(seg2->s_size),
1151 			    ANON_NOSLEEP)) {
1152 				anon_release(nahp, btop(asize));
1153 				ANON_LOCK_EXIT(&amp2->a_rwlock);
1154 				if (amp1 != NULL) {
1155 					ANON_LOCK_EXIT(&amp1->a_rwlock);
1156 				}
1157 				if (nvpage != NULL) {
1158 					kmem_free(nvpage, nvpsize);
1159 				}
1160 				return (-2);
1161 			}
1162 		}
1163 		if (amp1 != NULL) {
1164 			namp = amp1;
1165 			anon_release(amp1->ahp, btop(amp1->size));
1166 		}
1167 		if (amp2 != NULL) {
1168 			if (namp == NULL) {
1169 				ASSERT(amp1 == NULL);
1170 				namp = amp2;
1171 				anon_release(amp2->ahp, btop(amp2->size));
1172 			} else {
1173 				amp2->refcnt--;
1174 				ANON_LOCK_EXIT(&amp2->a_rwlock);
1175 				anonmap_free(amp2);
1176 			}
1177 			svd2->amp = NULL; /* needed for seg_free */
1178 		}
1179 		namp->ahp = nahp;
1180 		namp->size = asize;
1181 		svd1->amp = namp;
1182 		svd1->anon_index = 0;
1183 		ANON_LOCK_EXIT(&namp->a_rwlock);
1184 	}
1185 	/*
1186 	 * Now free the old vpage structures.
1187 	 */
1188 	if (nvpage != NULL) {
1189 		if (vpage1 != NULL) {
1190 			kmem_free(vpage1, vpgtob(npages1));
1191 		}
1192 		if (vpage2 != NULL) {
1193 			svd2->vpage = NULL;
1194 			kmem_free(vpage2, vpgtob(npages2));
1195 		}
1196 		if (svd2->pageprot) {
1197 			svd1->pageprot = 1;
1198 		}
1199 		if (svd2->pageadvice) {
1200 			svd1->pageadvice = 1;
1201 		}
1202 		if (svd2->pageswap) {
1203 			svd1->pageswap = 1;
1204 		}
1205 		svd1->vpage = nvpage;
1206 	}
1207 
1208 	/* all looks ok, merge segments */
1209 	svd1->swresv += svd2->swresv;
1210 	svd2->swresv = 0;  /* so seg_free doesn't release swap space */
1211 	size = seg2->s_size;
1212 	seg_free(seg2);
1213 	seg1->s_size += size;
1214 	return (0);
1215 }
1216 
1217 /*
1218  * Extend the previous segment (seg1) to include the
1219  * new segment (seg2 + a), if possible.
1220  * Return 0 on success.
1221  */
1222 static int
1223 segvn_extend_prev(seg1, seg2, a, swresv)
1224 	struct seg *seg1, *seg2;
1225 	struct segvn_crargs *a;
1226 	size_t swresv;
1227 {
1228 	struct segvn_data *svd1 = (struct segvn_data *)seg1->s_data;
1229 	size_t size;
1230 	struct anon_map *amp1;
1231 	struct vpage *new_vpage;
1232 
1233 	/*
1234 	 * We don't need any segment level locks for "segvn" data
1235 	 * since the address space is "write" locked.
1236 	 */
1237 	ASSERT(seg1->s_as && AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
1238 
1239 	if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie)) {
1240 		return (-1);
1241 	}
1242 
1243 	/* second segment is new, try to extend first */
1244 	/* XXX - should also check cred */
1245 	if (svd1->vp != a->vp || svd1->maxprot != a->maxprot ||
1246 	    (!svd1->pageprot && (svd1->prot != a->prot)) ||
1247 	    svd1->type != a->type || svd1->flags != a->flags ||
1248 	    seg1->s_szc != a->szc || svd1->softlockcnt_send > 0)
1249 		return (-1);
1250 
1251 	/* vp == NULL implies zfod, offset doesn't matter */
1252 	if (svd1->vp != NULL &&
1253 	    svd1->offset + seg1->s_size != (a->offset & PAGEMASK))
1254 		return (-1);
1255 
1256 	if (svd1->tr_state != SEGVN_TR_OFF) {
1257 		return (-1);
1258 	}
1259 
1260 	amp1 = svd1->amp;
1261 	if (amp1) {
1262 		pgcnt_t newpgs;
1263 
1264 		/*
1265 		 * Segment has private pages, can data structures
1266 		 * be expanded?
1267 		 *
1268 		 * Acquire the anon_map lock to prevent it from changing,
1269 		 * if it is shared.  This ensures that the anon_map
1270 		 * will not change while a thread which has a read/write
1271 		 * lock on an address space references it.
1272 		 * XXX - Don't need the anon_map lock at all if "refcnt"
1273 		 * is 1.
1274 		 *
1275 		 * Can't grow a MAP_SHARED segment with an anonmap because
1276 		 * there may be existing anon slots where we want to extend
1277 		 * the segment and we wouldn't know what to do with them
1278 		 * (e.g., for tmpfs right thing is to just leave them there,
1279 		 * for /dev/zero they should be cleared out).
1280 		 */
1281 		if (svd1->type == MAP_SHARED)
1282 			return (-1);
1283 
1284 		ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1285 		if (amp1->refcnt > 1) {
1286 			ANON_LOCK_EXIT(&amp1->a_rwlock);
1287 			return (-1);
1288 		}
1289 		newpgs = anon_grow(amp1->ahp, &svd1->anon_index,
1290 		    btop(seg1->s_size), btop(seg2->s_size), ANON_NOSLEEP);
1291 
1292 		if (newpgs == 0) {
1293 			ANON_LOCK_EXIT(&amp1->a_rwlock);
1294 			return (-1);
1295 		}
1296 		amp1->size = ptob(newpgs);
1297 		ANON_LOCK_EXIT(&amp1->a_rwlock);
1298 	}
1299 	if (svd1->vpage != NULL) {
1300 		struct vpage *vp, *evp;
1301 		new_vpage =
1302 		    kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1303 			KM_NOSLEEP);
1304 		if (new_vpage == NULL)
1305 			return (-1);
1306 		bcopy(svd1->vpage, new_vpage, vpgtob(seg_pages(seg1)));
1307 		kmem_free(svd1->vpage, vpgtob(seg_pages(seg1)));
1308 		svd1->vpage = new_vpage;
1309 
1310 		vp = new_vpage + seg_pages(seg1);
1311 		evp = vp + seg_pages(seg2);
1312 		for (; vp < evp; vp++)
1313 			VPP_SETPROT(vp, a->prot);
1314 		if (svd1->pageswap && swresv) {
1315 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1316 			ASSERT(swresv == seg2->s_size);
1317 			vp = new_vpage + seg_pages(seg1);
1318 			for (; vp < evp; vp++) {
1319 				VPP_SETSWAPRES(vp);
1320 			}
1321 		}
1322 	}
1323 	ASSERT(svd1->vpage != NULL || svd1->pageswap == 0);
1324 	size = seg2->s_size;
1325 	seg_free(seg2);
1326 	seg1->s_size += size;
1327 	svd1->swresv += swresv;
1328 	if (svd1->pageprot && (a->prot & PROT_WRITE) &&
1329 	    svd1->type == MAP_SHARED && svd1->vp != NULL &&
1330 	    (svd1->vp->v_flag & VVMEXEC)) {
1331 		ASSERT(vn_is_mapped(svd1->vp, V_WRITE));
1332 		segvn_inval_trcache(svd1->vp);
1333 	}
1334 	return (0);
1335 }
1336 
1337 /*
1338  * Extend the next segment (seg2) to include the
1339  * new segment (seg1 + a), if possible.
1340  * Return 0 on success.
1341  */
1342 static int
1343 segvn_extend_next(
1344 	struct seg *seg1,
1345 	struct seg *seg2,
1346 	struct segvn_crargs *a,
1347 	size_t swresv)
1348 {
1349 	struct segvn_data *svd2 = (struct segvn_data *)seg2->s_data;
1350 	size_t size;
1351 	struct anon_map *amp2;
1352 	struct vpage *new_vpage;
1353 
1354 	/*
1355 	 * We don't need any segment level locks for "segvn" data
1356 	 * since the address space is "write" locked.
1357 	 */
1358 	ASSERT(seg2->s_as && AS_WRITE_HELD(seg2->s_as, &seg2->s_as->a_lock));
1359 
1360 	if (HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
1361 		return (-1);
1362 	}
1363 
1364 	/* first segment is new, try to extend second */
1365 	/* XXX - should also check cred */
1366 	if (svd2->vp != a->vp || svd2->maxprot != a->maxprot ||
1367 	    (!svd2->pageprot && (svd2->prot != a->prot)) ||
1368 	    svd2->type != a->type || svd2->flags != a->flags ||
1369 	    seg2->s_szc != a->szc || svd2->softlockcnt_sbase > 0)
1370 		return (-1);
1371 	/* vp == NULL implies zfod, offset doesn't matter */
1372 	if (svd2->vp != NULL &&
1373 	    (a->offset & PAGEMASK) + seg1->s_size != svd2->offset)
1374 		return (-1);
1375 
1376 	if (svd2->tr_state != SEGVN_TR_OFF) {
1377 		return (-1);
1378 	}
1379 
1380 	amp2 = svd2->amp;
1381 	if (amp2) {
1382 		pgcnt_t newpgs;
1383 
1384 		/*
1385 		 * Segment has private pages, can data structures
1386 		 * be expanded?
1387 		 *
1388 		 * Acquire the anon_map lock to prevent it from changing,
1389 		 * if it is shared.  This ensures that the anon_map
1390 		 * will not change while a thread which has a read/write
1391 		 * lock on an address space references it.
1392 		 *
1393 		 * XXX - Don't need the anon_map lock at all if "refcnt"
1394 		 * is 1.
1395 		 */
1396 		if (svd2->type == MAP_SHARED)
1397 			return (-1);
1398 
1399 		ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1400 		if (amp2->refcnt > 1) {
1401 			ANON_LOCK_EXIT(&amp2->a_rwlock);
1402 			return (-1);
1403 		}
1404 		newpgs = anon_grow(amp2->ahp, &svd2->anon_index,
1405 		    btop(seg2->s_size), btop(seg1->s_size),
1406 		    ANON_NOSLEEP | ANON_GROWDOWN);
1407 
1408 		if (newpgs == 0) {
1409 			ANON_LOCK_EXIT(&amp2->a_rwlock);
1410 			return (-1);
1411 		}
1412 		amp2->size = ptob(newpgs);
1413 		ANON_LOCK_EXIT(&amp2->a_rwlock);
1414 	}
1415 	if (svd2->vpage != NULL) {
1416 		struct vpage *vp, *evp;
1417 		new_vpage =
1418 		    kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1419 		    KM_NOSLEEP);
1420 		if (new_vpage == NULL) {
1421 			/* Not merging segments so adjust anon_index back */
1422 			if (amp2)
1423 				svd2->anon_index += seg_pages(seg1);
1424 			return (-1);
1425 		}
1426 		bcopy(svd2->vpage, new_vpage + seg_pages(seg1),
1427 		    vpgtob(seg_pages(seg2)));
1428 		kmem_free(svd2->vpage, vpgtob(seg_pages(seg2)));
1429 		svd2->vpage = new_vpage;
1430 
1431 		vp = new_vpage;
1432 		evp = vp + seg_pages(seg1);
1433 		for (; vp < evp; vp++)
1434 			VPP_SETPROT(vp, a->prot);
1435 		if (svd2->pageswap && swresv) {
1436 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1437 			ASSERT(swresv == seg1->s_size);
1438 			vp = new_vpage;
1439 			for (; vp < evp; vp++) {
1440 				VPP_SETSWAPRES(vp);
1441 			}
1442 		}
1443 	}
1444 	ASSERT(svd2->vpage != NULL || svd2->pageswap == 0);
1445 	size = seg1->s_size;
1446 	seg_free(seg1);
1447 	seg2->s_size += size;
1448 	seg2->s_base -= size;
1449 	svd2->offset -= size;
1450 	svd2->swresv += swresv;
1451 	if (svd2->pageprot && (a->prot & PROT_WRITE) &&
1452 	    svd2->type == MAP_SHARED && svd2->vp != NULL &&
1453 	    (svd2->vp->v_flag & VVMEXEC)) {
1454 		ASSERT(vn_is_mapped(svd2->vp, V_WRITE));
1455 		segvn_inval_trcache(svd2->vp);
1456 	}
1457 	return (0);
1458 }
1459 
1460 static int
1461 segvn_dup(struct seg *seg, struct seg *newseg)
1462 {
1463 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1464 	struct segvn_data *newsvd;
1465 	pgcnt_t npages = seg_pages(seg);
1466 	int error = 0;
1467 	uint_t prot;
1468 	size_t len;
1469 	struct anon_map *amp;
1470 
1471 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1472 	ASSERT(newseg->s_as->a_proc->p_parent == curproc);
1473 
1474 	/*
1475 	 * If segment has anon reserved, reserve more for the new seg.
1476 	 * For a MAP_NORESERVE segment swresv will be a count of all the
1477 	 * allocated anon slots; thus we reserve for the child as many slots
1478 	 * as the parent has allocated. This semantic prevents the child or
1479 	 * parent from dieing during a copy-on-write fault caused by trying
1480 	 * to write a shared pre-existing anon page.
1481 	 */
1482 	if ((len = svd->swresv) != 0) {
1483 		if (anon_resv(svd->swresv) == 0)
1484 			return (ENOMEM);
1485 
1486 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
1487 		    seg, len, 0);
1488 	}
1489 
1490 	newsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
1491 
1492 	newseg->s_ops = &segvn_ops;
1493 	newseg->s_data = (void *)newsvd;
1494 	newseg->s_szc = seg->s_szc;
1495 
1496 	newsvd->seg = newseg;
1497 	if ((newsvd->vp = svd->vp) != NULL) {
1498 		VN_HOLD(svd->vp);
1499 		if (svd->type == MAP_SHARED)
1500 			lgrp_shm_policy_init(NULL, svd->vp);
1501 	}
1502 	newsvd->offset = svd->offset;
1503 	newsvd->prot = svd->prot;
1504 	newsvd->maxprot = svd->maxprot;
1505 	newsvd->pageprot = svd->pageprot;
1506 	newsvd->type = svd->type;
1507 	newsvd->cred = svd->cred;
1508 	crhold(newsvd->cred);
1509 	newsvd->advice = svd->advice;
1510 	newsvd->pageadvice = svd->pageadvice;
1511 	newsvd->swresv = svd->swresv;
1512 	newsvd->pageswap = svd->pageswap;
1513 	newsvd->flags = svd->flags;
1514 	newsvd->softlockcnt = 0;
1515 	newsvd->softlockcnt_sbase = 0;
1516 	newsvd->softlockcnt_send = 0;
1517 	newsvd->policy_info = svd->policy_info;
1518 	newsvd->rcookie = HAT_INVALID_REGION_COOKIE;
1519 
1520 	if ((amp = svd->amp) == NULL || svd->tr_state == SEGVN_TR_ON) {
1521 		/*
1522 		 * Not attaching to a shared anon object.
1523 		 */
1524 		ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie) ||
1525 		    svd->tr_state == SEGVN_TR_OFF);
1526 		if (svd->tr_state == SEGVN_TR_ON) {
1527 			ASSERT(newsvd->vp != NULL && amp != NULL);
1528 			newsvd->tr_state = SEGVN_TR_INIT;
1529 		} else {
1530 			newsvd->tr_state = svd->tr_state;
1531 		}
1532 		newsvd->amp = NULL;
1533 		newsvd->anon_index = 0;
1534 	} else {
1535 		/* regions for now are only used on pure vnode segments */
1536 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
1537 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1538 		newsvd->tr_state = SEGVN_TR_OFF;
1539 		if (svd->type == MAP_SHARED) {
1540 			newsvd->amp = amp;
1541 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1542 			amp->refcnt++;
1543 			ANON_LOCK_EXIT(&amp->a_rwlock);
1544 			newsvd->anon_index = svd->anon_index;
1545 		} else {
1546 			int reclaim = 1;
1547 
1548 			/*
1549 			 * Allocate and initialize new anon_map structure.
1550 			 */
1551 			newsvd->amp = anonmap_alloc(newseg->s_size, 0,
1552 			    ANON_SLEEP);
1553 			newsvd->amp->a_szc = newseg->s_szc;
1554 			newsvd->anon_index = 0;
1555 
1556 			/*
1557 			 * We don't have to acquire the anon_map lock
1558 			 * for the new segment (since it belongs to an
1559 			 * address space that is still not associated
1560 			 * with any process), or the segment in the old
1561 			 * address space (since all threads in it
1562 			 * are stopped while duplicating the address space).
1563 			 */
1564 
1565 			/*
1566 			 * The goal of the following code is to make sure that
1567 			 * softlocked pages do not end up as copy on write
1568 			 * pages.  This would cause problems where one
1569 			 * thread writes to a page that is COW and a different
1570 			 * thread in the same process has softlocked it.  The
1571 			 * softlock lock would move away from this process
1572 			 * because the write would cause this process to get
1573 			 * a copy (without the softlock).
1574 			 *
1575 			 * The strategy here is to just break the
1576 			 * sharing on pages that could possibly be
1577 			 * softlocked.
1578 			 */
1579 retry:
1580 			if (svd->softlockcnt) {
1581 				struct anon *ap, *newap;
1582 				size_t i;
1583 				uint_t vpprot;
1584 				page_t *anon_pl[1+1], *pp;
1585 				caddr_t addr;
1586 				ulong_t old_idx = svd->anon_index;
1587 				ulong_t new_idx = 0;
1588 
1589 				/*
1590 				 * The softlock count might be non zero
1591 				 * because some pages are still stuck in the
1592 				 * cache for lazy reclaim. Flush the cache
1593 				 * now. This should drop the count to zero.
1594 				 * [or there is really I/O going on to these
1595 				 * pages]. Note, we have the writers lock so
1596 				 * nothing gets inserted during the flush.
1597 				 */
1598 				if (reclaim == 1) {
1599 					segvn_purge(seg);
1600 					reclaim = 0;
1601 					goto retry;
1602 				}
1603 				i = btopr(seg->s_size);
1604 				addr = seg->s_base;
1605 				/*
1606 				 * XXX break cow sharing using PAGESIZE
1607 				 * pages. They will be relocated into larger
1608 				 * pages at fault time.
1609 				 */
1610 				while (i-- > 0) {
1611 					if (ap = anon_get_ptr(amp->ahp,
1612 					    old_idx)) {
1613 						error = anon_getpage(&ap,
1614 						    &vpprot, anon_pl, PAGESIZE,
1615 						    seg, addr, S_READ,
1616 						    svd->cred);
1617 						if (error) {
1618 							newsvd->vpage = NULL;
1619 							goto out;
1620 						}
1621 						/*
1622 						 * prot need not be computed
1623 						 * below 'cause anon_private is
1624 						 * going to ignore it anyway
1625 						 * as child doesn't inherit
1626 						 * pagelock from parent.
1627 						 */
1628 						prot = svd->pageprot ?
1629 						    VPP_PROT(
1630 						    &svd->vpage[
1631 						    seg_page(seg, addr)])
1632 						    : svd->prot;
1633 						pp = anon_private(&newap,
1634 						    newseg, addr, prot,
1635 						    anon_pl[0],	0,
1636 						    newsvd->cred);
1637 						if (pp == NULL) {
1638 							/* no mem abort */
1639 							newsvd->vpage = NULL;
1640 							error = ENOMEM;
1641 							goto out;
1642 						}
1643 						(void) anon_set_ptr(
1644 						    newsvd->amp->ahp, new_idx,
1645 						    newap, ANON_SLEEP);
1646 						page_unlock(pp);
1647 					}
1648 					addr += PAGESIZE;
1649 					old_idx++;
1650 					new_idx++;
1651 				}
1652 			} else {	/* common case */
1653 				if (seg->s_szc != 0) {
1654 					/*
1655 					 * If at least one of anon slots of a
1656 					 * large page exists then make sure
1657 					 * all anon slots of a large page
1658 					 * exist to avoid partial cow sharing
1659 					 * of a large page in the future.
1660 					 */
1661 					anon_dup_fill_holes(amp->ahp,
1662 					    svd->anon_index, newsvd->amp->ahp,
1663 					    0, seg->s_size, seg->s_szc,
1664 					    svd->vp != NULL);
1665 				} else {
1666 					anon_dup(amp->ahp, svd->anon_index,
1667 					    newsvd->amp->ahp, 0, seg->s_size);
1668 				}
1669 
1670 				hat_clrattr(seg->s_as->a_hat, seg->s_base,
1671 				    seg->s_size, PROT_WRITE);
1672 			}
1673 		}
1674 	}
1675 	/*
1676 	 * If necessary, create a vpage structure for the new segment.
1677 	 * Do not copy any page lock indications.
1678 	 */
1679 	if (svd->vpage != NULL) {
1680 		uint_t i;
1681 		struct vpage *ovp = svd->vpage;
1682 		struct vpage *nvp;
1683 
1684 		nvp = newsvd->vpage =
1685 		    kmem_alloc(vpgtob(npages), KM_SLEEP);
1686 		for (i = 0; i < npages; i++) {
1687 			*nvp = *ovp++;
1688 			VPP_CLRPPLOCK(nvp++);
1689 		}
1690 	} else
1691 		newsvd->vpage = NULL;
1692 
1693 	/* Inform the vnode of the new mapping */
1694 	if (newsvd->vp != NULL) {
1695 		error = VOP_ADDMAP(newsvd->vp, (offset_t)newsvd->offset,
1696 		    newseg->s_as, newseg->s_base, newseg->s_size, newsvd->prot,
1697 		    newsvd->maxprot, newsvd->type, newsvd->cred, NULL);
1698 	}
1699 out:
1700 	if (error == 0 && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1701 		ASSERT(newsvd->amp == NULL);
1702 		ASSERT(newsvd->tr_state == SEGVN_TR_OFF);
1703 		newsvd->rcookie = svd->rcookie;
1704 		hat_dup_region(newseg->s_as->a_hat, newsvd->rcookie);
1705 	}
1706 	return (error);
1707 }
1708 
1709 
1710 /*
1711  * callback function to invoke free_vp_pages() for only those pages actually
1712  * processed by the HAT when a shared region is destroyed.
1713  */
1714 extern int free_pages;
1715 
1716 static void
1717 segvn_hat_rgn_unload_callback(caddr_t saddr, caddr_t eaddr, caddr_t r_saddr,
1718     size_t r_size, void *r_obj, u_offset_t r_objoff)
1719 {
1720 	u_offset_t off;
1721 	size_t len;
1722 	vnode_t *vp = (vnode_t *)r_obj;
1723 
1724 	ASSERT(eaddr > saddr);
1725 	ASSERT(saddr >= r_saddr);
1726 	ASSERT(saddr < r_saddr + r_size);
1727 	ASSERT(eaddr > r_saddr);
1728 	ASSERT(eaddr <= r_saddr + r_size);
1729 	ASSERT(vp != NULL);
1730 
1731 	if (!free_pages) {
1732 		return;
1733 	}
1734 
1735 	len = eaddr - saddr;
1736 	off = (saddr - r_saddr) + r_objoff;
1737 	free_vp_pages(vp, off, len);
1738 }
1739 
1740 /*
1741  * callback function used by segvn_unmap to invoke free_vp_pages() for only
1742  * those pages actually processed by the HAT
1743  */
1744 static void
1745 segvn_hat_unload_callback(hat_callback_t *cb)
1746 {
1747 	struct seg		*seg = cb->hcb_data;
1748 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
1749 	size_t			len;
1750 	u_offset_t		off;
1751 
1752 	ASSERT(svd->vp != NULL);
1753 	ASSERT(cb->hcb_end_addr > cb->hcb_start_addr);
1754 	ASSERT(cb->hcb_start_addr >= seg->s_base);
1755 
1756 	len = cb->hcb_end_addr - cb->hcb_start_addr;
1757 	off = cb->hcb_start_addr - seg->s_base;
1758 	free_vp_pages(svd->vp, svd->offset + off, len);
1759 }
1760 
1761 /*
1762  * This function determines the number of bytes of swap reserved by
1763  * a segment for which per-page accounting is present. It is used to
1764  * calculate the correct value of a segvn_data's swresv.
1765  */
1766 static size_t
1767 segvn_count_swap_by_vpages(struct seg *seg)
1768 {
1769 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1770 	struct vpage *vp, *evp;
1771 	size_t nswappages = 0;
1772 
1773 	ASSERT(svd->pageswap);
1774 	ASSERT(svd->vpage != NULL);
1775 
1776 	evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
1777 
1778 	for (vp = svd->vpage; vp < evp; vp++) {
1779 		if (VPP_ISSWAPRES(vp))
1780 			nswappages++;
1781 	}
1782 
1783 	return (nswappages << PAGESHIFT);
1784 }
1785 
1786 static int
1787 segvn_unmap(struct seg *seg, caddr_t addr, size_t len)
1788 {
1789 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1790 	struct segvn_data *nsvd;
1791 	struct seg *nseg;
1792 	struct anon_map *amp;
1793 	pgcnt_t	opages;		/* old segment size in pages */
1794 	pgcnt_t	npages;		/* new segment size in pages */
1795 	pgcnt_t	dpages;		/* pages being deleted (unmapped) */
1796 	hat_callback_t callback;	/* used for free_vp_pages() */
1797 	hat_callback_t *cbp = NULL;
1798 	caddr_t nbase;
1799 	size_t nsize;
1800 	size_t oswresv;
1801 	int reclaim = 1;
1802 
1803 	/*
1804 	 * We don't need any segment level locks for "segvn" data
1805 	 * since the address space is "write" locked.
1806 	 */
1807 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1808 
1809 	/*
1810 	 * Fail the unmap if pages are SOFTLOCKed through this mapping.
1811 	 * softlockcnt is protected from change by the as write lock.
1812 	 */
1813 retry:
1814 	if (svd->softlockcnt > 0) {
1815 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1816 
1817 		/*
1818 		 * If this is shared segment non 0 softlockcnt
1819 		 * means locked pages are still in use.
1820 		 */
1821 		if (svd->type == MAP_SHARED) {
1822 			return (EAGAIN);
1823 		}
1824 
1825 		/*
1826 		 * since we do have the writers lock nobody can fill
1827 		 * the cache during the purge. The flush either succeeds
1828 		 * or we still have pending I/Os.
1829 		 */
1830 		if (reclaim == 1) {
1831 			segvn_purge(seg);
1832 			reclaim = 0;
1833 			goto retry;
1834 		}
1835 		return (EAGAIN);
1836 	}
1837 
1838 	/*
1839 	 * Check for bad sizes
1840 	 */
1841 	if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
1842 	    (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
1843 		panic("segvn_unmap");
1844 		/*NOTREACHED*/
1845 	}
1846 
1847 	if (seg->s_szc != 0) {
1848 		size_t pgsz = page_get_pagesize(seg->s_szc);
1849 		int err;
1850 		if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
1851 			ASSERT(seg->s_base != addr || seg->s_size != len);
1852 			if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1853 				ASSERT(svd->amp == NULL);
1854 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
1855 				hat_leave_region(seg->s_as->a_hat,
1856 				    svd->rcookie, HAT_REGION_TEXT);
1857 				svd->rcookie = HAT_INVALID_REGION_COOKIE;
1858 				/*
1859 				 * could pass a flag to segvn_demote_range()
1860 				 * below to tell it not to do any unloads but
1861 				 * this case is rare enough to not bother for
1862 				 * now.
1863 				 */
1864 			} else if (svd->tr_state == SEGVN_TR_INIT) {
1865 				svd->tr_state = SEGVN_TR_OFF;
1866 			} else if (svd->tr_state == SEGVN_TR_ON) {
1867 				ASSERT(svd->amp != NULL);
1868 				segvn_textunrepl(seg, 1);
1869 				ASSERT(svd->amp == NULL);
1870 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
1871 			}
1872 			VM_STAT_ADD(segvnvmstats.demoterange[0]);
1873 			err = segvn_demote_range(seg, addr, len, SDR_END, 0);
1874 			if (err == 0) {
1875 				return (IE_RETRY);
1876 			}
1877 			return (err);
1878 		}
1879 	}
1880 
1881 	/* Inform the vnode of the unmapping. */
1882 	if (svd->vp) {
1883 		int error;
1884 
1885 		error = VOP_DELMAP(svd->vp,
1886 		    (offset_t)svd->offset + (uintptr_t)(addr - seg->s_base),
1887 		    seg->s_as, addr, len, svd->prot, svd->maxprot,
1888 		    svd->type, svd->cred, NULL);
1889 
1890 		if (error == EAGAIN)
1891 			return (error);
1892 	}
1893 
1894 	/*
1895 	 * Remove any page locks set through this mapping.
1896 	 * If text replication is not off no page locks could have been
1897 	 * established via this mapping.
1898 	 */
1899 	if (svd->tr_state == SEGVN_TR_OFF) {
1900 		(void) segvn_lockop(seg, addr, len, 0, MC_UNLOCK, NULL, 0);
1901 	}
1902 
1903 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1904 		ASSERT(svd->amp == NULL);
1905 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1906 		ASSERT(svd->type == MAP_PRIVATE);
1907 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
1908 		    HAT_REGION_TEXT);
1909 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
1910 	} else if (svd->tr_state == SEGVN_TR_ON) {
1911 		ASSERT(svd->amp != NULL);
1912 		ASSERT(svd->pageprot == 0 && !(svd->prot & PROT_WRITE));
1913 		segvn_textunrepl(seg, 1);
1914 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
1915 	} else {
1916 		if (svd->tr_state != SEGVN_TR_OFF) {
1917 			ASSERT(svd->tr_state == SEGVN_TR_INIT);
1918 			svd->tr_state = SEGVN_TR_OFF;
1919 		}
1920 		/*
1921 		 * Unload any hardware translations in the range to be taken
1922 		 * out. Use a callback to invoke free_vp_pages() effectively.
1923 		 */
1924 		if (svd->vp != NULL && free_pages != 0) {
1925 			callback.hcb_data = seg;
1926 			callback.hcb_function = segvn_hat_unload_callback;
1927 			cbp = &callback;
1928 		}
1929 		hat_unload_callback(seg->s_as->a_hat, addr, len,
1930 		    HAT_UNLOAD_UNMAP, cbp);
1931 
1932 		if (svd->type == MAP_SHARED && svd->vp != NULL &&
1933 		    (svd->vp->v_flag & VVMEXEC) &&
1934 		    ((svd->prot & PROT_WRITE) || svd->pageprot)) {
1935 			segvn_inval_trcache(svd->vp);
1936 		}
1937 	}
1938 
1939 	/*
1940 	 * Check for entire segment
1941 	 */
1942 	if (addr == seg->s_base && len == seg->s_size) {
1943 		seg_free(seg);
1944 		return (0);
1945 	}
1946 
1947 	opages = seg_pages(seg);
1948 	dpages = btop(len);
1949 	npages = opages - dpages;
1950 	amp = svd->amp;
1951 	ASSERT(amp == NULL || amp->a_szc >= seg->s_szc);
1952 
1953 	/*
1954 	 * Check for beginning of segment
1955 	 */
1956 	if (addr == seg->s_base) {
1957 		if (svd->vpage != NULL) {
1958 			size_t nbytes;
1959 			struct vpage *ovpage;
1960 
1961 			ovpage = svd->vpage;	/* keep pointer to vpage */
1962 
1963 			nbytes = vpgtob(npages);
1964 			svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
1965 			bcopy(&ovpage[dpages], svd->vpage, nbytes);
1966 
1967 			/* free up old vpage */
1968 			kmem_free(ovpage, vpgtob(opages));
1969 		}
1970 		if (amp != NULL) {
1971 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1972 			if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
1973 				/*
1974 				 * Shared anon map is no longer in use. Before
1975 				 * freeing its pages purge all entries from
1976 				 * pcache that belong to this amp.
1977 				 */
1978 				if (svd->type == MAP_SHARED) {
1979 					ASSERT(amp->refcnt == 1);
1980 					ASSERT(svd->softlockcnt == 0);
1981 					anonmap_purge(amp);
1982 				}
1983 				/*
1984 				 * Free up now unused parts of anon_map array.
1985 				 */
1986 				if (amp->a_szc == seg->s_szc) {
1987 					if (seg->s_szc != 0) {
1988 						anon_free_pages(amp->ahp,
1989 						    svd->anon_index, len,
1990 						    seg->s_szc);
1991 					} else {
1992 						anon_free(amp->ahp,
1993 						    svd->anon_index,
1994 						    len);
1995 					}
1996 				} else {
1997 					ASSERT(svd->type == MAP_SHARED);
1998 					ASSERT(amp->a_szc > seg->s_szc);
1999 					anon_shmap_free_pages(amp,
2000 					    svd->anon_index, len);
2001 				}
2002 
2003 				/*
2004 				 * Unreserve swap space for the
2005 				 * unmapped chunk of this segment in
2006 				 * case it's MAP_SHARED
2007 				 */
2008 				if (svd->type == MAP_SHARED) {
2009 					anon_unresv_zone(len,
2010 					    seg->s_as->a_proc->p_zone);
2011 					amp->swresv -= len;
2012 				}
2013 			}
2014 			ANON_LOCK_EXIT(&amp->a_rwlock);
2015 			svd->anon_index += dpages;
2016 		}
2017 		if (svd->vp != NULL)
2018 			svd->offset += len;
2019 
2020 		seg->s_base += len;
2021 		seg->s_size -= len;
2022 
2023 		if (svd->swresv) {
2024 			if (svd->flags & MAP_NORESERVE) {
2025 				ASSERT(amp);
2026 				oswresv = svd->swresv;
2027 
2028 				svd->swresv = ptob(anon_pages(amp->ahp,
2029 				    svd->anon_index, npages));
2030 				anon_unresv_zone(oswresv - svd->swresv,
2031 				    seg->s_as->a_proc->p_zone);
2032 			} else {
2033 				size_t unlen;
2034 
2035 				if (svd->pageswap) {
2036 					oswresv = svd->swresv;
2037 					svd->swresv =
2038 					    segvn_count_swap_by_vpages(seg);
2039 					ASSERT(oswresv >= svd->swresv);
2040 					unlen = oswresv - svd->swresv;
2041 				} else {
2042 					svd->swresv -= len;
2043 					ASSERT(svd->swresv == seg->s_size);
2044 					unlen = len;
2045 				}
2046 				anon_unresv_zone(unlen,
2047 				    seg->s_as->a_proc->p_zone);
2048 			}
2049 			TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2050 			    seg, len, 0);
2051 		}
2052 
2053 		return (0);
2054 	}
2055 
2056 	/*
2057 	 * Check for end of segment
2058 	 */
2059 	if (addr + len == seg->s_base + seg->s_size) {
2060 		if (svd->vpage != NULL) {
2061 			size_t nbytes;
2062 			struct vpage *ovpage;
2063 
2064 			ovpage = svd->vpage;	/* keep pointer to vpage */
2065 
2066 			nbytes = vpgtob(npages);
2067 			svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2068 			bcopy(ovpage, svd->vpage, nbytes);
2069 
2070 			/* free up old vpage */
2071 			kmem_free(ovpage, vpgtob(opages));
2072 
2073 		}
2074 		if (amp != NULL) {
2075 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2076 			if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2077 				/*
2078 				 * Free up now unused parts of anon_map array.
2079 				 */
2080 				ulong_t an_idx = svd->anon_index + npages;
2081 
2082 				/*
2083 				 * Shared anon map is no longer in use. Before
2084 				 * freeing its pages purge all entries from
2085 				 * pcache that belong to this amp.
2086 				 */
2087 				if (svd->type == MAP_SHARED) {
2088 					ASSERT(amp->refcnt == 1);
2089 					ASSERT(svd->softlockcnt == 0);
2090 					anonmap_purge(amp);
2091 				}
2092 
2093 				if (amp->a_szc == seg->s_szc) {
2094 					if (seg->s_szc != 0) {
2095 						anon_free_pages(amp->ahp,
2096 						    an_idx, len,
2097 						    seg->s_szc);
2098 					} else {
2099 						anon_free(amp->ahp, an_idx,
2100 						    len);
2101 					}
2102 				} else {
2103 					ASSERT(svd->type == MAP_SHARED);
2104 					ASSERT(amp->a_szc > seg->s_szc);
2105 					anon_shmap_free_pages(amp,
2106 					    an_idx, len);
2107 				}
2108 
2109 				/*
2110 				 * Unreserve swap space for the
2111 				 * unmapped chunk of this segment in
2112 				 * case it's MAP_SHARED
2113 				 */
2114 				if (svd->type == MAP_SHARED) {
2115 					anon_unresv_zone(len,
2116 					    seg->s_as->a_proc->p_zone);
2117 					amp->swresv -= len;
2118 				}
2119 			}
2120 			ANON_LOCK_EXIT(&amp->a_rwlock);
2121 		}
2122 
2123 		seg->s_size -= len;
2124 
2125 		if (svd->swresv) {
2126 			if (svd->flags & MAP_NORESERVE) {
2127 				ASSERT(amp);
2128 				oswresv = svd->swresv;
2129 				svd->swresv = ptob(anon_pages(amp->ahp,
2130 				    svd->anon_index, npages));
2131 				anon_unresv_zone(oswresv - svd->swresv,
2132 				    seg->s_as->a_proc->p_zone);
2133 			} else {
2134 				size_t unlen;
2135 
2136 				if (svd->pageswap) {
2137 					oswresv = svd->swresv;
2138 					svd->swresv =
2139 					    segvn_count_swap_by_vpages(seg);
2140 					ASSERT(oswresv >= svd->swresv);
2141 					unlen = oswresv - svd->swresv;
2142 				} else {
2143 					svd->swresv -= len;
2144 					ASSERT(svd->swresv == seg->s_size);
2145 					unlen = len;
2146 				}
2147 				anon_unresv_zone(unlen,
2148 				    seg->s_as->a_proc->p_zone);
2149 			}
2150 			TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2151 			    "anon proc:%p %lu %u", seg, len, 0);
2152 		}
2153 
2154 		return (0);
2155 	}
2156 
2157 	/*
2158 	 * The section to go is in the middle of the segment,
2159 	 * have to make it into two segments.  nseg is made for
2160 	 * the high end while seg is cut down at the low end.
2161 	 */
2162 	nbase = addr + len;				/* new seg base */
2163 	nsize = (seg->s_base + seg->s_size) - nbase;	/* new seg size */
2164 	seg->s_size = addr - seg->s_base;		/* shrink old seg */
2165 	nseg = seg_alloc(seg->s_as, nbase, nsize);
2166 	if (nseg == NULL) {
2167 		panic("segvn_unmap seg_alloc");
2168 		/*NOTREACHED*/
2169 	}
2170 	nseg->s_ops = seg->s_ops;
2171 	nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
2172 	nseg->s_data = (void *)nsvd;
2173 	nseg->s_szc = seg->s_szc;
2174 	*nsvd = *svd;
2175 	nsvd->seg = nseg;
2176 	nsvd->offset = svd->offset + (uintptr_t)(nseg->s_base - seg->s_base);
2177 	nsvd->swresv = 0;
2178 	nsvd->softlockcnt = 0;
2179 	nsvd->softlockcnt_sbase = 0;
2180 	nsvd->softlockcnt_send = 0;
2181 	ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
2182 
2183 	if (svd->vp != NULL) {
2184 		VN_HOLD(nsvd->vp);
2185 		if (nsvd->type == MAP_SHARED)
2186 			lgrp_shm_policy_init(NULL, nsvd->vp);
2187 	}
2188 	crhold(svd->cred);
2189 
2190 	if (svd->vpage == NULL) {
2191 		nsvd->vpage = NULL;
2192 	} else {
2193 		/* need to split vpage into two arrays */
2194 		size_t nbytes;
2195 		struct vpage *ovpage;
2196 
2197 		ovpage = svd->vpage;		/* keep pointer to vpage */
2198 
2199 		npages = seg_pages(seg);	/* seg has shrunk */
2200 		nbytes = vpgtob(npages);
2201 		svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2202 
2203 		bcopy(ovpage, svd->vpage, nbytes);
2204 
2205 		npages = seg_pages(nseg);
2206 		nbytes = vpgtob(npages);
2207 		nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2208 
2209 		bcopy(&ovpage[opages - npages], nsvd->vpage, nbytes);
2210 
2211 		/* free up old vpage */
2212 		kmem_free(ovpage, vpgtob(opages));
2213 	}
2214 
2215 	if (amp == NULL) {
2216 		nsvd->amp = NULL;
2217 		nsvd->anon_index = 0;
2218 	} else {
2219 		/*
2220 		 * Need to create a new anon map for the new segment.
2221 		 * We'll also allocate a new smaller array for the old
2222 		 * smaller segment to save space.
2223 		 */
2224 		opages = btop((uintptr_t)(addr - seg->s_base));
2225 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2226 		if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2227 			/*
2228 			 * Free up now unused parts of anon_map array.
2229 			 */
2230 			ulong_t an_idx = svd->anon_index + opages;
2231 
2232 			/*
2233 			 * Shared anon map is no longer in use. Before
2234 			 * freeing its pages purge all entries from
2235 			 * pcache that belong to this amp.
2236 			 */
2237 			if (svd->type == MAP_SHARED) {
2238 				ASSERT(amp->refcnt == 1);
2239 				ASSERT(svd->softlockcnt == 0);
2240 				anonmap_purge(amp);
2241 			}
2242 
2243 			if (amp->a_szc == seg->s_szc) {
2244 				if (seg->s_szc != 0) {
2245 					anon_free_pages(amp->ahp, an_idx, len,
2246 					    seg->s_szc);
2247 				} else {
2248 					anon_free(amp->ahp, an_idx,
2249 					    len);
2250 				}
2251 			} else {
2252 				ASSERT(svd->type == MAP_SHARED);
2253 				ASSERT(amp->a_szc > seg->s_szc);
2254 				anon_shmap_free_pages(amp, an_idx, len);
2255 			}
2256 
2257 			/*
2258 			 * Unreserve swap space for the
2259 			 * unmapped chunk of this segment in
2260 			 * case it's MAP_SHARED
2261 			 */
2262 			if (svd->type == MAP_SHARED) {
2263 				anon_unresv_zone(len,
2264 				    seg->s_as->a_proc->p_zone);
2265 				amp->swresv -= len;
2266 			}
2267 		}
2268 		nsvd->anon_index = svd->anon_index +
2269 		    btop((uintptr_t)(nseg->s_base - seg->s_base));
2270 		if (svd->type == MAP_SHARED) {
2271 			amp->refcnt++;
2272 			nsvd->amp = amp;
2273 		} else {
2274 			struct anon_map *namp;
2275 			struct anon_hdr *nahp;
2276 
2277 			ASSERT(svd->type == MAP_PRIVATE);
2278 			nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
2279 			namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
2280 			namp->a_szc = seg->s_szc;
2281 			(void) anon_copy_ptr(amp->ahp, svd->anon_index, nahp,
2282 			    0, btop(seg->s_size), ANON_SLEEP);
2283 			(void) anon_copy_ptr(amp->ahp, nsvd->anon_index,
2284 			    namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
2285 			anon_release(amp->ahp, btop(amp->size));
2286 			svd->anon_index = 0;
2287 			nsvd->anon_index = 0;
2288 			amp->ahp = nahp;
2289 			amp->size = seg->s_size;
2290 			nsvd->amp = namp;
2291 		}
2292 		ANON_LOCK_EXIT(&amp->a_rwlock);
2293 	}
2294 	if (svd->swresv) {
2295 		if (svd->flags & MAP_NORESERVE) {
2296 			ASSERT(amp);
2297 			oswresv = svd->swresv;
2298 			svd->swresv = ptob(anon_pages(amp->ahp,
2299 			    svd->anon_index, btop(seg->s_size)));
2300 			nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
2301 			    nsvd->anon_index, btop(nseg->s_size)));
2302 			ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2303 			anon_unresv_zone(oswresv - (svd->swresv + nsvd->swresv),
2304 			    seg->s_as->a_proc->p_zone);
2305 		} else {
2306 			size_t unlen;
2307 
2308 			if (svd->pageswap) {
2309 				oswresv = svd->swresv;
2310 				svd->swresv = segvn_count_swap_by_vpages(seg);
2311 				nsvd->swresv = segvn_count_swap_by_vpages(nseg);
2312 				ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2313 				unlen = oswresv - (svd->swresv + nsvd->swresv);
2314 			} else {
2315 				if (seg->s_size + nseg->s_size + len !=
2316 				    svd->swresv) {
2317 					panic("segvn_unmap: cannot split "
2318 					    "swap reservation");
2319 					/*NOTREACHED*/
2320 				}
2321 				svd->swresv = seg->s_size;
2322 				nsvd->swresv = nseg->s_size;
2323 				unlen = len;
2324 			}
2325 			anon_unresv_zone(unlen,
2326 			    seg->s_as->a_proc->p_zone);
2327 		}
2328 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2329 		    seg, len, 0);
2330 	}
2331 
2332 	return (0);			/* I'm glad that's all over with! */
2333 }
2334 
2335 static void
2336 segvn_free(struct seg *seg)
2337 {
2338 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2339 	pgcnt_t npages = seg_pages(seg);
2340 	struct anon_map *amp;
2341 	size_t len;
2342 
2343 	/*
2344 	 * We don't need any segment level locks for "segvn" data
2345 	 * since the address space is "write" locked.
2346 	 */
2347 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
2348 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
2349 
2350 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2351 
2352 	/*
2353 	 * Be sure to unlock pages. XXX Why do things get free'ed instead
2354 	 * of unmapped? XXX
2355 	 */
2356 	(void) segvn_lockop(seg, seg->s_base, seg->s_size,
2357 	    0, MC_UNLOCK, NULL, 0);
2358 
2359 	/*
2360 	 * Deallocate the vpage and anon pointers if necessary and possible.
2361 	 */
2362 	if (svd->vpage != NULL) {
2363 		kmem_free(svd->vpage, vpgtob(npages));
2364 		svd->vpage = NULL;
2365 	}
2366 	if ((amp = svd->amp) != NULL) {
2367 		/*
2368 		 * If there are no more references to this anon_map
2369 		 * structure, then deallocate the structure after freeing
2370 		 * up all the anon slot pointers that we can.
2371 		 */
2372 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2373 		ASSERT(amp->a_szc >= seg->s_szc);
2374 		if (--amp->refcnt == 0) {
2375 			if (svd->type == MAP_PRIVATE) {
2376 				/*
2377 				 * Private - we only need to anon_free
2378 				 * the part that this segment refers to.
2379 				 */
2380 				if (seg->s_szc != 0) {
2381 					anon_free_pages(amp->ahp,
2382 					    svd->anon_index, seg->s_size,
2383 					    seg->s_szc);
2384 				} else {
2385 					anon_free(amp->ahp, svd->anon_index,
2386 					    seg->s_size);
2387 				}
2388 			} else {
2389 
2390 				/*
2391 				 * Shared anon map is no longer in use. Before
2392 				 * freeing its pages purge all entries from
2393 				 * pcache that belong to this amp.
2394 				 */
2395 				ASSERT(svd->softlockcnt == 0);
2396 				anonmap_purge(amp);
2397 
2398 				/*
2399 				 * Shared - anon_free the entire
2400 				 * anon_map's worth of stuff and
2401 				 * release any swap reservation.
2402 				 */
2403 				if (amp->a_szc != 0) {
2404 					anon_shmap_free_pages(amp, 0,
2405 					    amp->size);
2406 				} else {
2407 					anon_free(amp->ahp, 0, amp->size);
2408 				}
2409 				if ((len = amp->swresv) != 0) {
2410 					anon_unresv_zone(len,
2411 					    seg->s_as->a_proc->p_zone);
2412 					TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2413 					    "anon proc:%p %lu %u", seg, len, 0);
2414 				}
2415 			}
2416 			svd->amp = NULL;
2417 			ANON_LOCK_EXIT(&amp->a_rwlock);
2418 			anonmap_free(amp);
2419 		} else if (svd->type == MAP_PRIVATE) {
2420 			/*
2421 			 * We had a private mapping which still has
2422 			 * a held anon_map so just free up all the
2423 			 * anon slot pointers that we were using.
2424 			 */
2425 			if (seg->s_szc != 0) {
2426 				anon_free_pages(amp->ahp, svd->anon_index,
2427 				    seg->s_size, seg->s_szc);
2428 			} else {
2429 				anon_free(amp->ahp, svd->anon_index,
2430 				    seg->s_size);
2431 			}
2432 			ANON_LOCK_EXIT(&amp->a_rwlock);
2433 		} else {
2434 			ANON_LOCK_EXIT(&amp->a_rwlock);
2435 		}
2436 	}
2437 
2438 	/*
2439 	 * Release swap reservation.
2440 	 */
2441 	if ((len = svd->swresv) != 0) {
2442 		anon_unresv_zone(svd->swresv,
2443 		    seg->s_as->a_proc->p_zone);
2444 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2445 		    seg, len, 0);
2446 		svd->swresv = 0;
2447 	}
2448 	/*
2449 	 * Release claim on vnode, credentials, and finally free the
2450 	 * private data.
2451 	 */
2452 	if (svd->vp != NULL) {
2453 		if (svd->type == MAP_SHARED)
2454 			lgrp_shm_policy_fini(NULL, svd->vp);
2455 		VN_RELE(svd->vp);
2456 		svd->vp = NULL;
2457 	}
2458 	crfree(svd->cred);
2459 	svd->pageprot = 0;
2460 	svd->pageadvice = 0;
2461 	svd->pageswap = 0;
2462 	svd->cred = NULL;
2463 
2464 	/*
2465 	 * Take segfree_syncmtx lock to let segvn_reclaim() finish if it's
2466 	 * still working with this segment without holding as lock (in case
2467 	 * it's called by pcache async thread).
2468 	 */
2469 	ASSERT(svd->softlockcnt == 0);
2470 	mutex_enter(&svd->segfree_syncmtx);
2471 	mutex_exit(&svd->segfree_syncmtx);
2472 
2473 	seg->s_data = NULL;
2474 	kmem_cache_free(segvn_cache, svd);
2475 }
2476 
2477 /*
2478  * Do a F_SOFTUNLOCK call over the range requested.  The range must have
2479  * already been F_SOFTLOCK'ed.
2480  * Caller must always match addr and len of a softunlock with a previous
2481  * softlock with exactly the same addr and len.
2482  */
2483 static void
2484 segvn_softunlock(struct seg *seg, caddr_t addr, size_t len, enum seg_rw rw)
2485 {
2486 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2487 	page_t *pp;
2488 	caddr_t adr;
2489 	struct vnode *vp;
2490 	u_offset_t offset;
2491 	ulong_t anon_index;
2492 	struct anon_map *amp;
2493 	struct anon *ap = NULL;
2494 
2495 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2496 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
2497 
2498 	if ((amp = svd->amp) != NULL)
2499 		anon_index = svd->anon_index + seg_page(seg, addr);
2500 
2501 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
2502 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
2503 		hat_unlock_region(seg->s_as->a_hat, addr, len, svd->rcookie);
2504 	} else {
2505 		hat_unlock(seg->s_as->a_hat, addr, len);
2506 	}
2507 	for (adr = addr; adr < addr + len; adr += PAGESIZE) {
2508 		if (amp != NULL) {
2509 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2510 			if ((ap = anon_get_ptr(amp->ahp, anon_index++))
2511 			    != NULL) {
2512 				swap_xlate(ap, &vp, &offset);
2513 			} else {
2514 				vp = svd->vp;
2515 				offset = svd->offset +
2516 				    (uintptr_t)(adr - seg->s_base);
2517 			}
2518 			ANON_LOCK_EXIT(&amp->a_rwlock);
2519 		} else {
2520 			vp = svd->vp;
2521 			offset = svd->offset +
2522 			    (uintptr_t)(adr - seg->s_base);
2523 		}
2524 
2525 		/*
2526 		 * Use page_find() instead of page_lookup() to
2527 		 * find the page since we know that it is locked.
2528 		 */
2529 		pp = page_find(vp, offset);
2530 		if (pp == NULL) {
2531 			panic(
2532 			    "segvn_softunlock: addr %p, ap %p, vp %p, off %llx",
2533 			    (void *)adr, (void *)ap, (void *)vp, offset);
2534 			/*NOTREACHED*/
2535 		}
2536 
2537 		if (rw == S_WRITE) {
2538 			hat_setrefmod(pp);
2539 			if (seg->s_as->a_vbits)
2540 				hat_setstat(seg->s_as, adr, PAGESIZE,
2541 				    P_REF | P_MOD);
2542 		} else if (rw != S_OTHER) {
2543 			hat_setref(pp);
2544 			if (seg->s_as->a_vbits)
2545 				hat_setstat(seg->s_as, adr, PAGESIZE, P_REF);
2546 		}
2547 		TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2548 		    "segvn_fault:pp %p vp %p offset %llx", pp, vp, offset);
2549 		page_unlock(pp);
2550 	}
2551 	ASSERT(svd->softlockcnt >= btop(len));
2552 	if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -btop(len))) {
2553 		/*
2554 		 * All SOFTLOCKS are gone. Wakeup any waiting
2555 		 * unmappers so they can try again to unmap.
2556 		 * Check for waiters first without the mutex
2557 		 * held so we don't always grab the mutex on
2558 		 * softunlocks.
2559 		 */
2560 		if (AS_ISUNMAPWAIT(seg->s_as)) {
2561 			mutex_enter(&seg->s_as->a_contents);
2562 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2563 				AS_CLRUNMAPWAIT(seg->s_as);
2564 				cv_broadcast(&seg->s_as->a_cv);
2565 			}
2566 			mutex_exit(&seg->s_as->a_contents);
2567 		}
2568 	}
2569 }
2570 
2571 #define	PAGE_HANDLED	((page_t *)-1)
2572 
2573 /*
2574  * Release all the pages in the NULL terminated ppp list
2575  * which haven't already been converted to PAGE_HANDLED.
2576  */
2577 static void
2578 segvn_pagelist_rele(page_t **ppp)
2579 {
2580 	for (; *ppp != NULL; ppp++) {
2581 		if (*ppp != PAGE_HANDLED)
2582 			page_unlock(*ppp);
2583 	}
2584 }
2585 
2586 static int stealcow = 1;
2587 
2588 /*
2589  * Workaround for viking chip bug.  See bug id 1220902.
2590  * To fix this down in pagefault() would require importing so
2591  * much as and segvn code as to be unmaintainable.
2592  */
2593 int enable_mbit_wa = 0;
2594 
2595 /*
2596  * Handles all the dirty work of getting the right
2597  * anonymous pages and loading up the translations.
2598  * This routine is called only from segvn_fault()
2599  * when looping over the range of addresses requested.
2600  *
2601  * The basic algorithm here is:
2602  * 	If this is an anon_zero case
2603  *		Call anon_zero to allocate page
2604  *		Load up translation
2605  *		Return
2606  *	endif
2607  *	If this is an anon page
2608  *		Use anon_getpage to get the page
2609  *	else
2610  *		Find page in pl[] list passed in
2611  *	endif
2612  *	If not a cow
2613  *		Load up the translation to the page
2614  *		return
2615  *	endif
2616  *	Call anon_private to handle cow
2617  *	Load up (writable) translation to new page
2618  */
2619 static faultcode_t
2620 segvn_faultpage(
2621 	struct hat *hat,		/* the hat to use for mapping */
2622 	struct seg *seg,		/* seg_vn of interest */
2623 	caddr_t addr,			/* address in as */
2624 	u_offset_t off,			/* offset in vp */
2625 	struct vpage *vpage,		/* pointer to vpage for vp, off */
2626 	page_t *pl[],			/* object source page pointer */
2627 	uint_t vpprot,			/* access allowed to object pages */
2628 	enum fault_type type,		/* type of fault */
2629 	enum seg_rw rw,			/* type of access at fault */
2630 	int brkcow)			/* we may need to break cow */
2631 {
2632 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2633 	page_t *pp, **ppp;
2634 	uint_t pageflags = 0;
2635 	page_t *anon_pl[1 + 1];
2636 	page_t *opp = NULL;		/* original page */
2637 	uint_t prot;
2638 	int err;
2639 	int cow;
2640 	int claim;
2641 	int steal = 0;
2642 	ulong_t anon_index;
2643 	struct anon *ap, *oldap;
2644 	struct anon_map *amp;
2645 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
2646 	int anon_lock = 0;
2647 	anon_sync_obj_t cookie;
2648 
2649 	if (svd->flags & MAP_TEXT) {
2650 		hat_flag |= HAT_LOAD_TEXT;
2651 	}
2652 
2653 	ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
2654 	ASSERT(seg->s_szc == 0);
2655 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
2656 
2657 	/*
2658 	 * Initialize protection value for this page.
2659 	 * If we have per page protection values check it now.
2660 	 */
2661 	if (svd->pageprot) {
2662 		uint_t protchk;
2663 
2664 		switch (rw) {
2665 		case S_READ:
2666 			protchk = PROT_READ;
2667 			break;
2668 		case S_WRITE:
2669 			protchk = PROT_WRITE;
2670 			break;
2671 		case S_EXEC:
2672 			protchk = PROT_EXEC;
2673 			break;
2674 		case S_OTHER:
2675 		default:
2676 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
2677 			break;
2678 		}
2679 
2680 		prot = VPP_PROT(vpage);
2681 		if ((prot & protchk) == 0)
2682 			return (FC_PROT);	/* illegal access type */
2683 	} else {
2684 		prot = svd->prot;
2685 	}
2686 
2687 	if (type == F_SOFTLOCK) {
2688 		atomic_add_long((ulong_t *)&svd->softlockcnt, 1);
2689 	}
2690 
2691 	/*
2692 	 * Always acquire the anon array lock to prevent 2 threads from
2693 	 * allocating separate anon slots for the same "addr".
2694 	 */
2695 
2696 	if ((amp = svd->amp) != NULL) {
2697 		ASSERT(RW_READ_HELD(&amp->a_rwlock));
2698 		anon_index = svd->anon_index + seg_page(seg, addr);
2699 		anon_array_enter(amp, anon_index, &cookie);
2700 		anon_lock = 1;
2701 	}
2702 
2703 	if (svd->vp == NULL && amp != NULL) {
2704 		if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL) {
2705 			/*
2706 			 * Allocate a (normally) writable anonymous page of
2707 			 * zeroes. If no advance reservations, reserve now.
2708 			 */
2709 			if (svd->flags & MAP_NORESERVE) {
2710 				if (anon_resv_zone(ptob(1),
2711 				    seg->s_as->a_proc->p_zone)) {
2712 					atomic_add_long(&svd->swresv, ptob(1));
2713 				} else {
2714 					err = ENOMEM;
2715 					goto out;
2716 				}
2717 			}
2718 			if ((pp = anon_zero(seg, addr, &ap,
2719 			    svd->cred)) == NULL) {
2720 				err = ENOMEM;
2721 				goto out;	/* out of swap space */
2722 			}
2723 			/*
2724 			 * Re-acquire the anon_map lock and
2725 			 * initialize the anon array entry.
2726 			 */
2727 			(void) anon_set_ptr(amp->ahp, anon_index, ap,
2728 			    ANON_SLEEP);
2729 
2730 			ASSERT(pp->p_szc == 0);
2731 
2732 			/*
2733 			 * Handle pages that have been marked for migration
2734 			 */
2735 			if (lgrp_optimizations())
2736 				page_migrate(seg, addr, &pp, 1);
2737 
2738 			if (enable_mbit_wa) {
2739 				if (rw == S_WRITE)
2740 					hat_setmod(pp);
2741 				else if (!hat_ismod(pp))
2742 					prot &= ~PROT_WRITE;
2743 			}
2744 			/*
2745 			 * If AS_PAGLCK is set in a_flags (via memcntl(2)
2746 			 * with MC_LOCKAS, MCL_FUTURE) and this is a
2747 			 * MAP_NORESERVE segment, we may need to
2748 			 * permanently lock the page as it is being faulted
2749 			 * for the first time. The following text applies
2750 			 * only to MAP_NORESERVE segments:
2751 			 *
2752 			 * As per memcntl(2), if this segment was created
2753 			 * after MCL_FUTURE was applied (a "future"
2754 			 * segment), its pages must be locked.  If this
2755 			 * segment existed at MCL_FUTURE application (a
2756 			 * "past" segment), the interface is unclear.
2757 			 *
2758 			 * We decide to lock only if vpage is present:
2759 			 *
2760 			 * - "future" segments will have a vpage array (see
2761 			 *    as_map), and so will be locked as required
2762 			 *
2763 			 * - "past" segments may not have a vpage array,
2764 			 *    depending on whether events (such as
2765 			 *    mprotect) have occurred. Locking if vpage
2766 			 *    exists will preserve legacy behavior.  Not
2767 			 *    locking if vpage is absent, will not break
2768 			 *    the interface or legacy behavior.  Note that
2769 			 *    allocating vpage here if it's absent requires
2770 			 *    upgrading the segvn reader lock, the cost of
2771 			 *    which does not seem worthwhile.
2772 			 *
2773 			 * Usually testing and setting VPP_ISPPLOCK and
2774 			 * VPP_SETPPLOCK requires holding the segvn lock as
2775 			 * writer, but in this case all readers are
2776 			 * serializing on the anon array lock.
2777 			 */
2778 			if (AS_ISPGLCK(seg->s_as) && vpage != NULL &&
2779 			    (svd->flags & MAP_NORESERVE) &&
2780 			    !VPP_ISPPLOCK(vpage)) {
2781 				proc_t *p = seg->s_as->a_proc;
2782 				ASSERT(svd->type == MAP_PRIVATE);
2783 				mutex_enter(&p->p_lock);
2784 				if (rctl_incr_locked_mem(p, NULL, PAGESIZE,
2785 				    1) == 0) {
2786 					claim = VPP_PROT(vpage) & PROT_WRITE;
2787 					if (page_pp_lock(pp, claim, 0)) {
2788 						VPP_SETPPLOCK(vpage);
2789 					} else {
2790 						rctl_decr_locked_mem(p, NULL,
2791 						    PAGESIZE, 1);
2792 					}
2793 				}
2794 				mutex_exit(&p->p_lock);
2795 			}
2796 
2797 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2798 			hat_memload(hat, addr, pp, prot, hat_flag);
2799 
2800 			if (!(hat_flag & HAT_LOAD_LOCK))
2801 				page_unlock(pp);
2802 
2803 			anon_array_exit(&cookie);
2804 			return (0);
2805 		}
2806 	}
2807 
2808 	/*
2809 	 * Obtain the page structure via anon_getpage() if it is
2810 	 * a private copy of an object (the result of a previous
2811 	 * copy-on-write).
2812 	 */
2813 	if (amp != NULL) {
2814 		if ((ap = anon_get_ptr(amp->ahp, anon_index)) != NULL) {
2815 			err = anon_getpage(&ap, &vpprot, anon_pl, PAGESIZE,
2816 			    seg, addr, rw, svd->cred);
2817 			if (err)
2818 				goto out;
2819 
2820 			if (svd->type == MAP_SHARED) {
2821 				/*
2822 				 * If this is a shared mapping to an
2823 				 * anon_map, then ignore the write
2824 				 * permissions returned by anon_getpage().
2825 				 * They apply to the private mappings
2826 				 * of this anon_map.
2827 				 */
2828 				vpprot |= PROT_WRITE;
2829 			}
2830 			opp = anon_pl[0];
2831 		}
2832 	}
2833 
2834 	/*
2835 	 * Search the pl[] list passed in if it is from the
2836 	 * original object (i.e., not a private copy).
2837 	 */
2838 	if (opp == NULL) {
2839 		/*
2840 		 * Find original page.  We must be bringing it in
2841 		 * from the list in pl[].
2842 		 */
2843 		for (ppp = pl; (opp = *ppp) != NULL; ppp++) {
2844 			if (opp == PAGE_HANDLED)
2845 				continue;
2846 			ASSERT(opp->p_vnode == svd->vp); /* XXX */
2847 			if (opp->p_offset == off)
2848 				break;
2849 		}
2850 		if (opp == NULL) {
2851 			panic("segvn_faultpage not found");
2852 			/*NOTREACHED*/
2853 		}
2854 		*ppp = PAGE_HANDLED;
2855 
2856 	}
2857 
2858 	ASSERT(PAGE_LOCKED(opp));
2859 
2860 	TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2861 	    "segvn_fault:pp %p vp %p offset %llx", opp, NULL, 0);
2862 
2863 	/*
2864 	 * The fault is treated as a copy-on-write fault if a
2865 	 * write occurs on a private segment and the object
2866 	 * page (i.e., mapping) is write protected.  We assume
2867 	 * that fatal protection checks have already been made.
2868 	 */
2869 
2870 	if (brkcow) {
2871 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
2872 		cow = !(vpprot & PROT_WRITE);
2873 	} else if (svd->tr_state == SEGVN_TR_ON) {
2874 		/*
2875 		 * If we are doing text replication COW on first touch.
2876 		 */
2877 		ASSERT(amp != NULL);
2878 		ASSERT(svd->vp != NULL);
2879 		ASSERT(rw != S_WRITE);
2880 		cow = (ap == NULL);
2881 	} else {
2882 		cow = 0;
2883 	}
2884 
2885 	/*
2886 	 * If not a copy-on-write case load the translation
2887 	 * and return.
2888 	 */
2889 	if (cow == 0) {
2890 
2891 		/*
2892 		 * Handle pages that have been marked for migration
2893 		 */
2894 		if (lgrp_optimizations())
2895 			page_migrate(seg, addr, &opp, 1);
2896 
2897 		if (IS_VMODSORT(opp->p_vnode) || enable_mbit_wa) {
2898 			if (rw == S_WRITE)
2899 				hat_setmod(opp);
2900 			else if (rw != S_OTHER && !hat_ismod(opp))
2901 				prot &= ~PROT_WRITE;
2902 		}
2903 
2904 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
2905 		    (!svd->pageprot && svd->prot == (prot & vpprot)));
2906 		ASSERT(amp == NULL ||
2907 		    svd->rcookie == HAT_INVALID_REGION_COOKIE);
2908 		hat_memload_region(hat, addr, opp, prot & vpprot, hat_flag,
2909 		    svd->rcookie);
2910 
2911 		if (!(hat_flag & HAT_LOAD_LOCK))
2912 			page_unlock(opp);
2913 
2914 		if (anon_lock) {
2915 			anon_array_exit(&cookie);
2916 		}
2917 		return (0);
2918 	}
2919 
2920 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2921 
2922 	hat_setref(opp);
2923 
2924 	ASSERT(amp != NULL && anon_lock);
2925 
2926 	/*
2927 	 * Steal the page only if it isn't a private page
2928 	 * since stealing a private page is not worth the effort.
2929 	 */
2930 	if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL)
2931 		steal = 1;
2932 
2933 	/*
2934 	 * Steal the original page if the following conditions are true:
2935 	 *
2936 	 * We are low on memory, the page is not private, page is not large,
2937 	 * not shared, not modified, not `locked' or if we have it `locked'
2938 	 * (i.e., p_cowcnt == 1 and p_lckcnt == 0, which also implies
2939 	 * that the page is not shared) and if it doesn't have any
2940 	 * translations. page_struct_lock isn't needed to look at p_cowcnt
2941 	 * and p_lckcnt because we first get exclusive lock on page.
2942 	 */
2943 	(void) hat_pagesync(opp, HAT_SYNC_DONTZERO | HAT_SYNC_STOPON_MOD);
2944 
2945 	if (stealcow && freemem < minfree && steal && opp->p_szc == 0 &&
2946 	    page_tryupgrade(opp) && !hat_ismod(opp) &&
2947 	    ((opp->p_lckcnt == 0 && opp->p_cowcnt == 0) ||
2948 	    (opp->p_lckcnt == 0 && opp->p_cowcnt == 1 &&
2949 	    vpage != NULL && VPP_ISPPLOCK(vpage)))) {
2950 		/*
2951 		 * Check if this page has other translations
2952 		 * after unloading our translation.
2953 		 */
2954 		if (hat_page_is_mapped(opp)) {
2955 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2956 			hat_unload(seg->s_as->a_hat, addr, PAGESIZE,
2957 			    HAT_UNLOAD);
2958 		}
2959 
2960 		/*
2961 		 * hat_unload() might sync back someone else's recent
2962 		 * modification, so check again.
2963 		 */
2964 		if (!hat_ismod(opp) && !hat_page_is_mapped(opp))
2965 			pageflags |= STEAL_PAGE;
2966 	}
2967 
2968 	/*
2969 	 * If we have a vpage pointer, see if it indicates that we have
2970 	 * ``locked'' the page we map -- if so, tell anon_private to
2971 	 * transfer the locking resource to the new page.
2972 	 *
2973 	 * See Statement at the beginning of segvn_lockop regarding
2974 	 * the way lockcnts/cowcnts are handled during COW.
2975 	 *
2976 	 */
2977 	if (vpage != NULL && VPP_ISPPLOCK(vpage))
2978 		pageflags |= LOCK_PAGE;
2979 
2980 	/*
2981 	 * Allocate a private page and perform the copy.
2982 	 * For MAP_NORESERVE reserve swap space now, unless this
2983 	 * is a cow fault on an existing anon page in which case
2984 	 * MAP_NORESERVE will have made advance reservations.
2985 	 */
2986 	if ((svd->flags & MAP_NORESERVE) && (ap == NULL)) {
2987 		if (anon_resv_zone(ptob(1), seg->s_as->a_proc->p_zone)) {
2988 			atomic_add_long(&svd->swresv, ptob(1));
2989 		} else {
2990 			page_unlock(opp);
2991 			err = ENOMEM;
2992 			goto out;
2993 		}
2994 	}
2995 	oldap = ap;
2996 	pp = anon_private(&ap, seg, addr, prot, opp, pageflags, svd->cred);
2997 	if (pp == NULL) {
2998 		err = ENOMEM;	/* out of swap space */
2999 		goto out;
3000 	}
3001 
3002 	/*
3003 	 * If we copied away from an anonymous page, then
3004 	 * we are one step closer to freeing up an anon slot.
3005 	 *
3006 	 * NOTE:  The original anon slot must be released while
3007 	 * holding the "anon_map" lock.  This is necessary to prevent
3008 	 * other threads from obtaining a pointer to the anon slot
3009 	 * which may be freed if its "refcnt" is 1.
3010 	 */
3011 	if (oldap != NULL)
3012 		anon_decref(oldap);
3013 
3014 	(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
3015 
3016 	/*
3017 	 * Handle pages that have been marked for migration
3018 	 */
3019 	if (lgrp_optimizations())
3020 		page_migrate(seg, addr, &pp, 1);
3021 
3022 	ASSERT(pp->p_szc == 0);
3023 
3024 	ASSERT(!IS_VMODSORT(pp->p_vnode));
3025 	if (enable_mbit_wa) {
3026 		if (rw == S_WRITE)
3027 			hat_setmod(pp);
3028 		else if (!hat_ismod(pp))
3029 			prot &= ~PROT_WRITE;
3030 	}
3031 
3032 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
3033 	hat_memload(hat, addr, pp, prot, hat_flag);
3034 
3035 	if (!(hat_flag & HAT_LOAD_LOCK))
3036 		page_unlock(pp);
3037 
3038 	ASSERT(anon_lock);
3039 	anon_array_exit(&cookie);
3040 	return (0);
3041 out:
3042 	if (anon_lock)
3043 		anon_array_exit(&cookie);
3044 
3045 	if (type == F_SOFTLOCK) {
3046 		atomic_add_long((ulong_t *)&svd->softlockcnt, -1);
3047 	}
3048 	return (FC_MAKE_ERR(err));
3049 }
3050 
3051 /*
3052  * relocate a bunch of smaller targ pages into one large repl page. all targ
3053  * pages must be complete pages smaller than replacement pages.
3054  * it's assumed that no page's szc can change since they are all PAGESIZE or
3055  * complete large pages locked SHARED.
3056  */
3057 static void
3058 segvn_relocate_pages(page_t **targ, page_t *replacement)
3059 {
3060 	page_t *pp;
3061 	pgcnt_t repl_npgs, curnpgs;
3062 	pgcnt_t i;
3063 	uint_t repl_szc = replacement->p_szc;
3064 	page_t *first_repl = replacement;
3065 	page_t *repl;
3066 	spgcnt_t npgs;
3067 
3068 	VM_STAT_ADD(segvnvmstats.relocatepages[0]);
3069 
3070 	ASSERT(repl_szc != 0);
3071 	npgs = repl_npgs = page_get_pagecnt(repl_szc);
3072 
3073 	i = 0;
3074 	while (repl_npgs) {
3075 		spgcnt_t nreloc;
3076 		int err;
3077 		ASSERT(replacement != NULL);
3078 		pp = targ[i];
3079 		ASSERT(pp->p_szc < repl_szc);
3080 		ASSERT(PAGE_EXCL(pp));
3081 		ASSERT(!PP_ISFREE(pp));
3082 		curnpgs = page_get_pagecnt(pp->p_szc);
3083 		if (curnpgs == 1) {
3084 			VM_STAT_ADD(segvnvmstats.relocatepages[1]);
3085 			repl = replacement;
3086 			page_sub(&replacement, repl);
3087 			ASSERT(PAGE_EXCL(repl));
3088 			ASSERT(!PP_ISFREE(repl));
3089 			ASSERT(repl->p_szc == repl_szc);
3090 		} else {
3091 			page_t *repl_savepp;
3092 			int j;
3093 			VM_STAT_ADD(segvnvmstats.relocatepages[2]);
3094 			repl_savepp = replacement;
3095 			for (j = 0; j < curnpgs; j++) {
3096 				repl = replacement;
3097 				page_sub(&replacement, repl);
3098 				ASSERT(PAGE_EXCL(repl));
3099 				ASSERT(!PP_ISFREE(repl));
3100 				ASSERT(repl->p_szc == repl_szc);
3101 				ASSERT(page_pptonum(targ[i + j]) ==
3102 				    page_pptonum(targ[i]) + j);
3103 			}
3104 			repl = repl_savepp;
3105 			ASSERT(IS_P2ALIGNED(page_pptonum(repl), curnpgs));
3106 		}
3107 		err = page_relocate(&pp, &repl, 0, 1, &nreloc, NULL);
3108 		if (err || nreloc != curnpgs) {
3109 			panic("segvn_relocate_pages: "
3110 			    "page_relocate failed err=%d curnpgs=%ld "
3111 			    "nreloc=%ld", err, curnpgs, nreloc);
3112 		}
3113 		ASSERT(curnpgs <= repl_npgs);
3114 		repl_npgs -= curnpgs;
3115 		i += curnpgs;
3116 	}
3117 	ASSERT(replacement == NULL);
3118 
3119 	repl = first_repl;
3120 	repl_npgs = npgs;
3121 	for (i = 0; i < repl_npgs; i++) {
3122 		ASSERT(PAGE_EXCL(repl));
3123 		ASSERT(!PP_ISFREE(repl));
3124 		targ[i] = repl;
3125 		page_downgrade(targ[i]);
3126 		repl++;
3127 	}
3128 }
3129 
3130 /*
3131  * Check if all pages in ppa array are complete smaller than szc pages and
3132  * their roots will still be aligned relative to their current size if the
3133  * entire ppa array is relocated into one szc page. If these conditions are
3134  * not met return 0.
3135  *
3136  * If all pages are properly aligned attempt to upgrade their locks
3137  * to exclusive mode. If it fails set *upgrdfail to 1 and return 0.
3138  * upgrdfail was set to 0 by caller.
3139  *
3140  * Return 1 if all pages are aligned and locked exclusively.
3141  *
3142  * If all pages in ppa array happen to be physically contiguous to make one
3143  * szc page and all exclusive locks are successfully obtained promote the page
3144  * size to szc and set *pszc to szc. Return 1 with pages locked shared.
3145  */
3146 static int
3147 segvn_full_szcpages(page_t **ppa, uint_t szc, int *upgrdfail, uint_t *pszc)
3148 {
3149 	page_t *pp;
3150 	pfn_t pfn;
3151 	pgcnt_t totnpgs = page_get_pagecnt(szc);
3152 	pfn_t first_pfn;
3153 	int contig = 1;
3154 	pgcnt_t i;
3155 	pgcnt_t j;
3156 	uint_t curszc;
3157 	pgcnt_t curnpgs;
3158 	int root = 0;
3159 
3160 	ASSERT(szc > 0);
3161 
3162 	VM_STAT_ADD(segvnvmstats.fullszcpages[0]);
3163 
3164 	for (i = 0; i < totnpgs; i++) {
3165 		pp = ppa[i];
3166 		ASSERT(PAGE_SHARED(pp));
3167 		ASSERT(!PP_ISFREE(pp));
3168 		pfn = page_pptonum(pp);
3169 		if (i == 0) {
3170 			if (!IS_P2ALIGNED(pfn, totnpgs)) {
3171 				contig = 0;
3172 			} else {
3173 				first_pfn = pfn;
3174 			}
3175 		} else if (contig && pfn != first_pfn + i) {
3176 			contig = 0;
3177 		}
3178 		if (pp->p_szc == 0) {
3179 			if (root) {
3180 				VM_STAT_ADD(segvnvmstats.fullszcpages[1]);
3181 				return (0);
3182 			}
3183 		} else if (!root) {
3184 			if ((curszc = pp->p_szc) >= szc) {
3185 				VM_STAT_ADD(segvnvmstats.fullszcpages[2]);
3186 				return (0);
3187 			}
3188 			if (curszc == 0) {
3189 				/*
3190 				 * p_szc changed means we don't have all pages
3191 				 * locked. return failure.
3192 				 */
3193 				VM_STAT_ADD(segvnvmstats.fullszcpages[3]);
3194 				return (0);
3195 			}
3196 			curnpgs = page_get_pagecnt(curszc);
3197 			if (!IS_P2ALIGNED(pfn, curnpgs) ||
3198 			    !IS_P2ALIGNED(i, curnpgs)) {
3199 				VM_STAT_ADD(segvnvmstats.fullszcpages[4]);
3200 				return (0);
3201 			}
3202 			root = 1;
3203 		} else {
3204 			ASSERT(i > 0);
3205 			VM_STAT_ADD(segvnvmstats.fullszcpages[5]);
3206 			if (pp->p_szc != curszc) {
3207 				VM_STAT_ADD(segvnvmstats.fullszcpages[6]);
3208 				return (0);
3209 			}
3210 			if (pfn - 1 != page_pptonum(ppa[i - 1])) {
3211 				panic("segvn_full_szcpages: "
3212 				    "large page not physically contiguous");
3213 			}
3214 			if (P2PHASE(pfn, curnpgs) == curnpgs - 1) {
3215 				root = 0;
3216 			}
3217 		}
3218 	}
3219 
3220 	for (i = 0; i < totnpgs; i++) {
3221 		ASSERT(ppa[i]->p_szc < szc);
3222 		if (!page_tryupgrade(ppa[i])) {
3223 			for (j = 0; j < i; j++) {
3224 				page_downgrade(ppa[j]);
3225 			}
3226 			*pszc = ppa[i]->p_szc;
3227 			*upgrdfail = 1;
3228 			VM_STAT_ADD(segvnvmstats.fullszcpages[7]);
3229 			return (0);
3230 		}
3231 	}
3232 
3233 	/*
3234 	 * When a page is put a free cachelist its szc is set to 0.  if file
3235 	 * system reclaimed pages from cachelist targ pages will be physically
3236 	 * contiguous with 0 p_szc.  in this case just upgrade szc of targ
3237 	 * pages without any relocations.
3238 	 * To avoid any hat issues with previous small mappings
3239 	 * hat_pageunload() the target pages first.
3240 	 */
3241 	if (contig) {
3242 		VM_STAT_ADD(segvnvmstats.fullszcpages[8]);
3243 		for (i = 0; i < totnpgs; i++) {
3244 			(void) hat_pageunload(ppa[i], HAT_FORCE_PGUNLOAD);
3245 		}
3246 		for (i = 0; i < totnpgs; i++) {
3247 			ppa[i]->p_szc = szc;
3248 		}
3249 		for (i = 0; i < totnpgs; i++) {
3250 			ASSERT(PAGE_EXCL(ppa[i]));
3251 			page_downgrade(ppa[i]);
3252 		}
3253 		if (pszc != NULL) {
3254 			*pszc = szc;
3255 		}
3256 	}
3257 	VM_STAT_ADD(segvnvmstats.fullszcpages[9]);
3258 	return (1);
3259 }
3260 
3261 /*
3262  * Create physically contiguous pages for [vp, off] - [vp, off +
3263  * page_size(szc)) range and for private segment return them in ppa array.
3264  * Pages are created either via IO or relocations.
3265  *
3266  * Return 1 on success and 0 on failure.
3267  *
3268  * If physically contiguous pages already exist for this range return 1 without
3269  * filling ppa array. Caller initializes ppa[0] as NULL to detect that ppa
3270  * array wasn't filled. In this case caller fills ppa array via VOP_GETPAGE().
3271  */
3272 
3273 static int
3274 segvn_fill_vp_pages(struct segvn_data *svd, vnode_t *vp, u_offset_t off,
3275     uint_t szc, page_t **ppa, page_t **ppplist, uint_t *ret_pszc,
3276     int *downsize)
3277 
3278 {
3279 	page_t *pplist = *ppplist;
3280 	size_t pgsz = page_get_pagesize(szc);
3281 	pgcnt_t pages = btop(pgsz);
3282 	ulong_t start_off = off;
3283 	u_offset_t eoff = off + pgsz;
3284 	spgcnt_t nreloc;
3285 	u_offset_t io_off = off;
3286 	size_t io_len;
3287 	page_t *io_pplist = NULL;
3288 	page_t *done_pplist = NULL;
3289 	pgcnt_t pgidx = 0;
3290 	page_t *pp;
3291 	page_t *newpp;
3292 	page_t *targpp;
3293 	int io_err = 0;
3294 	int i;
3295 	pfn_t pfn;
3296 	ulong_t ppages;
3297 	page_t *targ_pplist = NULL;
3298 	page_t *repl_pplist = NULL;
3299 	page_t *tmp_pplist;
3300 	int nios = 0;
3301 	uint_t pszc;
3302 	struct vattr va;
3303 
3304 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[0]);
3305 
3306 	ASSERT(szc != 0);
3307 	ASSERT(pplist->p_szc == szc);
3308 
3309 	/*
3310 	 * downsize will be set to 1 only if we fail to lock pages. this will
3311 	 * allow subsequent faults to try to relocate the page again. If we
3312 	 * fail due to misalignment don't downsize and let the caller map the
3313 	 * whole region with small mappings to avoid more faults into the area
3314 	 * where we can't get large pages anyway.
3315 	 */
3316 	*downsize = 0;
3317 
3318 	while (off < eoff) {
3319 		newpp = pplist;
3320 		ASSERT(newpp != NULL);
3321 		ASSERT(PAGE_EXCL(newpp));
3322 		ASSERT(!PP_ISFREE(newpp));
3323 		/*
3324 		 * we pass NULL for nrelocp to page_lookup_create()
3325 		 * so that it doesn't relocate. We relocate here
3326 		 * later only after we make sure we can lock all
3327 		 * pages in the range we handle and they are all
3328 		 * aligned.
3329 		 */
3330 		pp = page_lookup_create(vp, off, SE_SHARED, newpp, NULL, 0);
3331 		ASSERT(pp != NULL);
3332 		ASSERT(!PP_ISFREE(pp));
3333 		ASSERT(pp->p_vnode == vp);
3334 		ASSERT(pp->p_offset == off);
3335 		if (pp == newpp) {
3336 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[1]);
3337 			page_sub(&pplist, pp);
3338 			ASSERT(PAGE_EXCL(pp));
3339 			ASSERT(page_iolock_assert(pp));
3340 			page_list_concat(&io_pplist, &pp);
3341 			off += PAGESIZE;
3342 			continue;
3343 		}
3344 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[2]);
3345 		pfn = page_pptonum(pp);
3346 		pszc = pp->p_szc;
3347 		if (pszc >= szc && targ_pplist == NULL && io_pplist == NULL &&
3348 		    IS_P2ALIGNED(pfn, pages)) {
3349 			ASSERT(repl_pplist == NULL);
3350 			ASSERT(done_pplist == NULL);
3351 			ASSERT(pplist == *ppplist);
3352 			page_unlock(pp);
3353 			page_free_replacement_page(pplist);
3354 			page_create_putback(pages);
3355 			*ppplist = NULL;
3356 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[3]);
3357 			return (1);
3358 		}
3359 		if (pszc >= szc) {
3360 			page_unlock(pp);
3361 			segvn_faultvnmpss_align_err1++;
3362 			goto out;
3363 		}
3364 		ppages = page_get_pagecnt(pszc);
3365 		if (!IS_P2ALIGNED(pfn, ppages)) {
3366 			ASSERT(pszc > 0);
3367 			/*
3368 			 * sizing down to pszc won't help.
3369 			 */
3370 			page_unlock(pp);
3371 			segvn_faultvnmpss_align_err2++;
3372 			goto out;
3373 		}
3374 		pfn = page_pptonum(newpp);
3375 		if (!IS_P2ALIGNED(pfn, ppages)) {
3376 			ASSERT(pszc > 0);
3377 			/*
3378 			 * sizing down to pszc won't help.
3379 			 */
3380 			page_unlock(pp);
3381 			segvn_faultvnmpss_align_err3++;
3382 			goto out;
3383 		}
3384 		if (!PAGE_EXCL(pp)) {
3385 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[4]);
3386 			page_unlock(pp);
3387 			*downsize = 1;
3388 			*ret_pszc = pp->p_szc;
3389 			goto out;
3390 		}
3391 		targpp = pp;
3392 		if (io_pplist != NULL) {
3393 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[5]);
3394 			io_len = off - io_off;
3395 			/*
3396 			 * Some file systems like NFS don't check EOF
3397 			 * conditions in VOP_PAGEIO(). Check it here
3398 			 * now that pages are locked SE_EXCL. Any file
3399 			 * truncation will wait until the pages are
3400 			 * unlocked so no need to worry that file will
3401 			 * be truncated after we check its size here.
3402 			 * XXX fix NFS to remove this check.
3403 			 */
3404 			va.va_mask = AT_SIZE;
3405 			if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL)) {
3406 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[6]);
3407 				page_unlock(targpp);
3408 				goto out;
3409 			}
3410 			if (btopr(va.va_size) < btopr(io_off + io_len)) {
3411 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[7]);
3412 				*downsize = 1;
3413 				*ret_pszc = 0;
3414 				page_unlock(targpp);
3415 				goto out;
3416 			}
3417 			io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3418 				B_READ, svd->cred, NULL);
3419 			if (io_err) {
3420 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[8]);
3421 				page_unlock(targpp);
3422 				if (io_err == EDEADLK) {
3423 					segvn_vmpss_pageio_deadlk_err++;
3424 				}
3425 				goto out;
3426 			}
3427 			nios++;
3428 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[9]);
3429 			while (io_pplist != NULL) {
3430 				pp = io_pplist;
3431 				page_sub(&io_pplist, pp);
3432 				ASSERT(page_iolock_assert(pp));
3433 				page_io_unlock(pp);
3434 				pgidx = (pp->p_offset - start_off) >>
3435 				    PAGESHIFT;
3436 				ASSERT(pgidx < pages);
3437 				ppa[pgidx] = pp;
3438 				page_list_concat(&done_pplist, &pp);
3439 			}
3440 		}
3441 		pp = targpp;
3442 		ASSERT(PAGE_EXCL(pp));
3443 		ASSERT(pp->p_szc <= pszc);
3444 		if (pszc != 0 && !group_page_trylock(pp, SE_EXCL)) {
3445 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[10]);
3446 			page_unlock(pp);
3447 			*downsize = 1;
3448 			*ret_pszc = pp->p_szc;
3449 			goto out;
3450 		}
3451 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[11]);
3452 		/*
3453 		 * page szc chould have changed before the entire group was
3454 		 * locked. reread page szc.
3455 		 */
3456 		pszc = pp->p_szc;
3457 		ppages = page_get_pagecnt(pszc);
3458 
3459 		/* link just the roots */
3460 		page_list_concat(&targ_pplist, &pp);
3461 		page_sub(&pplist, newpp);
3462 		page_list_concat(&repl_pplist, &newpp);
3463 		off += PAGESIZE;
3464 		while (--ppages != 0) {
3465 			newpp = pplist;
3466 			page_sub(&pplist, newpp);
3467 			off += PAGESIZE;
3468 		}
3469 		io_off = off;
3470 	}
3471 	if (io_pplist != NULL) {
3472 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[12]);
3473 		io_len = eoff - io_off;
3474 		va.va_mask = AT_SIZE;
3475 		if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL) != 0) {
3476 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[13]);
3477 			goto out;
3478 		}
3479 		if (btopr(va.va_size) < btopr(io_off + io_len)) {
3480 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[14]);
3481 			*downsize = 1;
3482 			*ret_pszc = 0;
3483 			goto out;
3484 		}
3485 		io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3486 		    B_READ, svd->cred, NULL);
3487 		if (io_err) {
3488 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[15]);
3489 			if (io_err == EDEADLK) {
3490 				segvn_vmpss_pageio_deadlk_err++;
3491 			}
3492 			goto out;
3493 		}
3494 		nios++;
3495 		while (io_pplist != NULL) {
3496 			pp = io_pplist;
3497 			page_sub(&io_pplist, pp);
3498 			ASSERT(page_iolock_assert(pp));
3499 			page_io_unlock(pp);
3500 			pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3501 			ASSERT(pgidx < pages);
3502 			ppa[pgidx] = pp;
3503 		}
3504 	}
3505 	/*
3506 	 * we're now bound to succeed or panic.
3507 	 * remove pages from done_pplist. it's not needed anymore.
3508 	 */
3509 	while (done_pplist != NULL) {
3510 		pp = done_pplist;
3511 		page_sub(&done_pplist, pp);
3512 	}
3513 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[16]);
3514 	ASSERT(pplist == NULL);
3515 	*ppplist = NULL;
3516 	while (targ_pplist != NULL) {
3517 		int ret;
3518 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[17]);
3519 		ASSERT(repl_pplist);
3520 		pp = targ_pplist;
3521 		page_sub(&targ_pplist, pp);
3522 		pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3523 		newpp = repl_pplist;
3524 		page_sub(&repl_pplist, newpp);
3525 #ifdef DEBUG
3526 		pfn = page_pptonum(pp);
3527 		pszc = pp->p_szc;
3528 		ppages = page_get_pagecnt(pszc);
3529 		ASSERT(IS_P2ALIGNED(pfn, ppages));
3530 		pfn = page_pptonum(newpp);
3531 		ASSERT(IS_P2ALIGNED(pfn, ppages));
3532 		ASSERT(P2PHASE(pfn, pages) == pgidx);
3533 #endif
3534 		nreloc = 0;
3535 		ret = page_relocate(&pp, &newpp, 0, 1, &nreloc, NULL);
3536 		if (ret != 0 || nreloc == 0) {
3537 			panic("segvn_fill_vp_pages: "
3538 			    "page_relocate failed");
3539 		}
3540 		pp = newpp;
3541 		while (nreloc-- != 0) {
3542 			ASSERT(PAGE_EXCL(pp));
3543 			ASSERT(pp->p_vnode == vp);
3544 			ASSERT(pgidx ==
3545 			    ((pp->p_offset - start_off) >> PAGESHIFT));
3546 			ppa[pgidx++] = pp;
3547 			pp++;
3548 		}
3549 	}
3550 
3551 	if (svd->type == MAP_PRIVATE) {
3552 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[18]);
3553 		for (i = 0; i < pages; i++) {
3554 			ASSERT(ppa[i] != NULL);
3555 			ASSERT(PAGE_EXCL(ppa[i]));
3556 			ASSERT(ppa[i]->p_vnode == vp);
3557 			ASSERT(ppa[i]->p_offset ==
3558 			    start_off + (i << PAGESHIFT));
3559 			page_downgrade(ppa[i]);
3560 		}
3561 		ppa[pages] = NULL;
3562 	} else {
3563 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[19]);
3564 		/*
3565 		 * the caller will still call VOP_GETPAGE() for shared segments
3566 		 * to check FS write permissions. For private segments we map
3567 		 * file read only anyway.  so no VOP_GETPAGE is needed.
3568 		 */
3569 		for (i = 0; i < pages; i++) {
3570 			ASSERT(ppa[i] != NULL);
3571 			ASSERT(PAGE_EXCL(ppa[i]));
3572 			ASSERT(ppa[i]->p_vnode == vp);
3573 			ASSERT(ppa[i]->p_offset ==
3574 			    start_off + (i << PAGESHIFT));
3575 			page_unlock(ppa[i]);
3576 		}
3577 		ppa[0] = NULL;
3578 	}
3579 
3580 	return (1);
3581 out:
3582 	/*
3583 	 * Do the cleanup. Unlock target pages we didn't relocate. They are
3584 	 * linked on targ_pplist by root pages. reassemble unused replacement
3585 	 * and io pages back to pplist.
3586 	 */
3587 	if (io_pplist != NULL) {
3588 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[20]);
3589 		pp = io_pplist;
3590 		do {
3591 			ASSERT(pp->p_vnode == vp);
3592 			ASSERT(pp->p_offset == io_off);
3593 			ASSERT(page_iolock_assert(pp));
3594 			page_io_unlock(pp);
3595 			page_hashout(pp, NULL);
3596 			io_off += PAGESIZE;
3597 		} while ((pp = pp->p_next) != io_pplist);
3598 		page_list_concat(&io_pplist, &pplist);
3599 		pplist = io_pplist;
3600 	}
3601 	tmp_pplist = NULL;
3602 	while (targ_pplist != NULL) {
3603 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[21]);
3604 		pp = targ_pplist;
3605 		ASSERT(PAGE_EXCL(pp));
3606 		page_sub(&targ_pplist, pp);
3607 
3608 		pszc = pp->p_szc;
3609 		ppages = page_get_pagecnt(pszc);
3610 		ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3611 
3612 		if (pszc != 0) {
3613 			group_page_unlock(pp);
3614 		}
3615 		page_unlock(pp);
3616 
3617 		pp = repl_pplist;
3618 		ASSERT(pp != NULL);
3619 		ASSERT(PAGE_EXCL(pp));
3620 		ASSERT(pp->p_szc == szc);
3621 		page_sub(&repl_pplist, pp);
3622 
3623 		ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3624 
3625 		/* relink replacement page */
3626 		page_list_concat(&tmp_pplist, &pp);
3627 		while (--ppages != 0) {
3628 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[22]);
3629 			pp++;
3630 			ASSERT(PAGE_EXCL(pp));
3631 			ASSERT(pp->p_szc == szc);
3632 			page_list_concat(&tmp_pplist, &pp);
3633 		}
3634 	}
3635 	if (tmp_pplist != NULL) {
3636 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[23]);
3637 		page_list_concat(&tmp_pplist, &pplist);
3638 		pplist = tmp_pplist;
3639 	}
3640 	/*
3641 	 * at this point all pages are either on done_pplist or
3642 	 * pplist. They can't be all on done_pplist otherwise
3643 	 * we'd've been done.
3644 	 */
3645 	ASSERT(pplist != NULL);
3646 	if (nios != 0) {
3647 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[24]);
3648 		pp = pplist;
3649 		do {
3650 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[25]);
3651 			ASSERT(pp->p_szc == szc);
3652 			ASSERT(PAGE_EXCL(pp));
3653 			ASSERT(pp->p_vnode != vp);
3654 			pp->p_szc = 0;
3655 		} while ((pp = pp->p_next) != pplist);
3656 
3657 		pp = done_pplist;
3658 		do {
3659 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[26]);
3660 			ASSERT(pp->p_szc == szc);
3661 			ASSERT(PAGE_EXCL(pp));
3662 			ASSERT(pp->p_vnode == vp);
3663 			pp->p_szc = 0;
3664 		} while ((pp = pp->p_next) != done_pplist);
3665 
3666 		while (pplist != NULL) {
3667 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[27]);
3668 			pp = pplist;
3669 			page_sub(&pplist, pp);
3670 			page_free(pp, 0);
3671 		}
3672 
3673 		while (done_pplist != NULL) {
3674 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[28]);
3675 			pp = done_pplist;
3676 			page_sub(&done_pplist, pp);
3677 			page_unlock(pp);
3678 		}
3679 		*ppplist = NULL;
3680 		return (0);
3681 	}
3682 	ASSERT(pplist == *ppplist);
3683 	if (io_err) {
3684 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[29]);
3685 		/*
3686 		 * don't downsize on io error.
3687 		 * see if vop_getpage succeeds.
3688 		 * pplist may still be used in this case
3689 		 * for relocations.
3690 		 */
3691 		return (0);
3692 	}
3693 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[30]);
3694 	page_free_replacement_page(pplist);
3695 	page_create_putback(pages);
3696 	*ppplist = NULL;
3697 	return (0);
3698 }
3699 
3700 int segvn_anypgsz = 0;
3701 
3702 #define	SEGVN_RESTORE_SOFTLOCK_VP(type, pages) 				\
3703 		if ((type) == F_SOFTLOCK) {				\
3704 			atomic_add_long((ulong_t *)&(svd)->softlockcnt, \
3705 			    -(pages));					\
3706 		}
3707 
3708 #define	SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot)		\
3709 		if (IS_VMODSORT((ppa)[0]->p_vnode)) {			\
3710 			if ((rw) == S_WRITE) {				\
3711 				for (i = 0; i < (pages); i++) {		\
3712 					ASSERT((ppa)[i]->p_vnode ==	\
3713 					    (ppa)[0]->p_vnode);		\
3714 					hat_setmod((ppa)[i]);		\
3715 				}					\
3716 			} else if ((rw) != S_OTHER &&			\
3717 			    ((prot) & (vpprot) & PROT_WRITE)) {		\
3718 				for (i = 0; i < (pages); i++) {		\
3719 					ASSERT((ppa)[i]->p_vnode ==	\
3720 					    (ppa)[0]->p_vnode);		\
3721 					if (!hat_ismod((ppa)[i])) {	\
3722 						prot &= ~PROT_WRITE;	\
3723 						break;			\
3724 					}				\
3725 				}					\
3726 			}						\
3727 		}
3728 
3729 #ifdef  VM_STATS
3730 
3731 #define	SEGVN_VMSTAT_FLTVNPAGES(idx)					\
3732 		VM_STAT_ADD(segvnvmstats.fltvnpages[(idx)]);
3733 
3734 #else /* VM_STATS */
3735 
3736 #define	SEGVN_VMSTAT_FLTVNPAGES(idx)
3737 
3738 #endif
3739 
3740 static faultcode_t
3741 segvn_fault_vnodepages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
3742     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
3743     caddr_t eaddr, int brkcow)
3744 {
3745 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
3746 	struct anon_map *amp = svd->amp;
3747 	uchar_t segtype = svd->type;
3748 	uint_t szc = seg->s_szc;
3749 	size_t pgsz = page_get_pagesize(szc);
3750 	size_t maxpgsz = pgsz;
3751 	pgcnt_t pages = btop(pgsz);
3752 	pgcnt_t maxpages = pages;
3753 	size_t ppasize = (pages + 1) * sizeof (page_t *);
3754 	caddr_t a = lpgaddr;
3755 	caddr_t	maxlpgeaddr = lpgeaddr;
3756 	u_offset_t off = svd->offset + (uintptr_t)(a - seg->s_base);
3757 	ulong_t aindx = svd->anon_index + seg_page(seg, a);
3758 	struct vpage *vpage = (svd->vpage != NULL) ?
3759 	    &svd->vpage[seg_page(seg, a)] : NULL;
3760 	vnode_t *vp = svd->vp;
3761 	page_t **ppa;
3762 	uint_t	pszc;
3763 	size_t	ppgsz;
3764 	pgcnt_t	ppages;
3765 	faultcode_t err = 0;
3766 	int ierr;
3767 	int vop_size_err = 0;
3768 	uint_t protchk, prot, vpprot;
3769 	ulong_t i;
3770 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
3771 	anon_sync_obj_t an_cookie;
3772 	enum seg_rw arw;
3773 	int alloc_failed = 0;
3774 	int adjszc_chk;
3775 	struct vattr va;
3776 	int xhat = 0;
3777 	page_t *pplist;
3778 	pfn_t pfn;
3779 	int physcontig;
3780 	int upgrdfail;
3781 	int segvn_anypgsz_vnode = 0; /* for now map vnode with 2 page sizes */
3782 	int tron = (svd->tr_state == SEGVN_TR_ON);
3783 
3784 	ASSERT(szc != 0);
3785 	ASSERT(vp != NULL);
3786 	ASSERT(brkcow == 0 || amp != NULL);
3787 	ASSERT(tron == 0 || amp != NULL);
3788 	ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
3789 	ASSERT(!(svd->flags & MAP_NORESERVE));
3790 	ASSERT(type != F_SOFTUNLOCK);
3791 	ASSERT(IS_P2ALIGNED(a, maxpgsz));
3792 	ASSERT(amp == NULL || IS_P2ALIGNED(aindx, maxpages));
3793 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
3794 	ASSERT(seg->s_szc < NBBY * sizeof (int));
3795 	ASSERT(type != F_SOFTLOCK || lpgeaddr - a == maxpgsz);
3796 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
3797 
3798 	VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltvnpages[0]);
3799 	VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltvnpages[1]);
3800 
3801 	if (svd->flags & MAP_TEXT) {
3802 		hat_flag |= HAT_LOAD_TEXT;
3803 	}
3804 
3805 	if (svd->pageprot) {
3806 		switch (rw) {
3807 		case S_READ:
3808 			protchk = PROT_READ;
3809 			break;
3810 		case S_WRITE:
3811 			protchk = PROT_WRITE;
3812 			break;
3813 		case S_EXEC:
3814 			protchk = PROT_EXEC;
3815 			break;
3816 		case S_OTHER:
3817 		default:
3818 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
3819 			break;
3820 		}
3821 	} else {
3822 		prot = svd->prot;
3823 		/* caller has already done segment level protection check. */
3824 	}
3825 
3826 	if (seg->s_as->a_hat != hat) {
3827 		xhat = 1;
3828 	}
3829 
3830 	if (rw == S_WRITE && segtype == MAP_PRIVATE) {
3831 		SEGVN_VMSTAT_FLTVNPAGES(2);
3832 		arw = S_READ;
3833 	} else {
3834 		arw = rw;
3835 	}
3836 
3837 	ppa = kmem_alloc(ppasize, KM_SLEEP);
3838 
3839 	VM_STAT_COND_ADD(amp != NULL, segvnvmstats.fltvnpages[3]);
3840 
3841 	for (;;) {
3842 		adjszc_chk = 0;
3843 		for (; a < lpgeaddr; a += pgsz, off += pgsz, aindx += pages) {
3844 			if (adjszc_chk) {
3845 				while (szc < seg->s_szc) {
3846 					uintptr_t e;
3847 					uint_t tszc;
3848 					tszc = segvn_anypgsz_vnode ? szc + 1 :
3849 					    seg->s_szc;
3850 					ppgsz = page_get_pagesize(tszc);
3851 					if (!IS_P2ALIGNED(a, ppgsz) ||
3852 					    ((alloc_failed >> tszc) & 0x1)) {
3853 						break;
3854 					}
3855 					SEGVN_VMSTAT_FLTVNPAGES(4);
3856 					szc = tszc;
3857 					pgsz = ppgsz;
3858 					pages = btop(pgsz);
3859 					e = P2ROUNDUP((uintptr_t)eaddr, pgsz);
3860 					lpgeaddr = (caddr_t)e;
3861 				}
3862 			}
3863 
3864 		again:
3865 			if (IS_P2ALIGNED(a, maxpgsz) && amp != NULL) {
3866 				ASSERT(IS_P2ALIGNED(aindx, maxpages));
3867 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
3868 				anon_array_enter(amp, aindx, &an_cookie);
3869 				if (anon_get_ptr(amp->ahp, aindx) != NULL) {
3870 					SEGVN_VMSTAT_FLTVNPAGES(5);
3871 					ASSERT(anon_pages(amp->ahp, aindx,
3872 					    maxpages) == maxpages);
3873 					anon_array_exit(&an_cookie);
3874 					ANON_LOCK_EXIT(&amp->a_rwlock);
3875 					err = segvn_fault_anonpages(hat, seg,
3876 					    a, a + maxpgsz, type, rw,
3877 					    MAX(a, addr),
3878 					    MIN(a + maxpgsz, eaddr), brkcow);
3879 					if (err != 0) {
3880 						SEGVN_VMSTAT_FLTVNPAGES(6);
3881 						goto out;
3882 					}
3883 					if (szc < seg->s_szc) {
3884 						szc = seg->s_szc;
3885 						pgsz = maxpgsz;
3886 						pages = maxpages;
3887 						lpgeaddr = maxlpgeaddr;
3888 					}
3889 					goto next;
3890 				} else {
3891 					ASSERT(anon_pages(amp->ahp, aindx,
3892 					    maxpages) == 0);
3893 					SEGVN_VMSTAT_FLTVNPAGES(7);
3894 					anon_array_exit(&an_cookie);
3895 					ANON_LOCK_EXIT(&amp->a_rwlock);
3896 				}
3897 			}
3898 			ASSERT(!brkcow || IS_P2ALIGNED(a, maxpgsz));
3899 			ASSERT(!tron || IS_P2ALIGNED(a, maxpgsz));
3900 
3901 			if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
3902 				ASSERT(vpage != NULL);
3903 				prot = VPP_PROT(vpage);
3904 				ASSERT(sameprot(seg, a, maxpgsz));
3905 				if ((prot & protchk) == 0) {
3906 					SEGVN_VMSTAT_FLTVNPAGES(8);
3907 					err = FC_PROT;
3908 					goto out;
3909 				}
3910 			}
3911 			if (type == F_SOFTLOCK) {
3912 				atomic_add_long((ulong_t *)&svd->softlockcnt,
3913 				    pages);
3914 			}
3915 
3916 			pplist = NULL;
3917 			physcontig = 0;
3918 			ppa[0] = NULL;
3919 			if (!brkcow && !tron && szc &&
3920 			    !page_exists_physcontig(vp, off, szc,
3921 			    segtype == MAP_PRIVATE ? ppa : NULL)) {
3922 				SEGVN_VMSTAT_FLTVNPAGES(9);
3923 				if (page_alloc_pages(vp, seg, a, &pplist, NULL,
3924 				    szc, 0, 0) && type != F_SOFTLOCK) {
3925 					SEGVN_VMSTAT_FLTVNPAGES(10);
3926 					pszc = 0;
3927 					ierr = -1;
3928 					alloc_failed |= (1 << szc);
3929 					break;
3930 				}
3931 				if (pplist != NULL &&
3932 				    vp->v_mpssdata == SEGVN_PAGEIO) {
3933 					int downsize;
3934 					SEGVN_VMSTAT_FLTVNPAGES(11);
3935 					physcontig = segvn_fill_vp_pages(svd,
3936 					    vp, off, szc, ppa, &pplist,
3937 					    &pszc, &downsize);
3938 					ASSERT(!physcontig || pplist == NULL);
3939 					if (!physcontig && downsize &&
3940 					    type != F_SOFTLOCK) {
3941 						ASSERT(pplist == NULL);
3942 						SEGVN_VMSTAT_FLTVNPAGES(12);
3943 						ierr = -1;
3944 						break;
3945 					}
3946 					ASSERT(!physcontig ||
3947 					    segtype == MAP_PRIVATE ||
3948 					    ppa[0] == NULL);
3949 					if (physcontig && ppa[0] == NULL) {
3950 						physcontig = 0;
3951 					}
3952 				}
3953 			} else if (!brkcow && !tron && szc && ppa[0] != NULL) {
3954 				SEGVN_VMSTAT_FLTVNPAGES(13);
3955 				ASSERT(segtype == MAP_PRIVATE);
3956 				physcontig = 1;
3957 			}
3958 
3959 			if (!physcontig) {
3960 				SEGVN_VMSTAT_FLTVNPAGES(14);
3961 				ppa[0] = NULL;
3962 				ierr = VOP_GETPAGE(vp, (offset_t)off, pgsz,
3963 				    &vpprot, ppa, pgsz, seg, a, arw,
3964 				    svd->cred, NULL);
3965 #ifdef DEBUG
3966 				if (ierr == 0) {
3967 					for (i = 0; i < pages; i++) {
3968 						ASSERT(PAGE_LOCKED(ppa[i]));
3969 						ASSERT(!PP_ISFREE(ppa[i]));
3970 						ASSERT(ppa[i]->p_vnode == vp);
3971 						ASSERT(ppa[i]->p_offset ==
3972 						    off + (i << PAGESHIFT));
3973 					}
3974 				}
3975 #endif /* DEBUG */
3976 				if (segtype == MAP_PRIVATE) {
3977 					SEGVN_VMSTAT_FLTVNPAGES(15);
3978 					vpprot &= ~PROT_WRITE;
3979 				}
3980 			} else {
3981 				ASSERT(segtype == MAP_PRIVATE);
3982 				SEGVN_VMSTAT_FLTVNPAGES(16);
3983 				vpprot = PROT_ALL & ~PROT_WRITE;
3984 				ierr = 0;
3985 			}
3986 
3987 			if (ierr != 0) {
3988 				SEGVN_VMSTAT_FLTVNPAGES(17);
3989 				if (pplist != NULL) {
3990 					SEGVN_VMSTAT_FLTVNPAGES(18);
3991 					page_free_replacement_page(pplist);
3992 					page_create_putback(pages);
3993 				}
3994 				SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
3995 				if (a + pgsz <= eaddr) {
3996 					SEGVN_VMSTAT_FLTVNPAGES(19);
3997 					err = FC_MAKE_ERR(ierr);
3998 					goto out;
3999 				}
4000 				va.va_mask = AT_SIZE;
4001 				if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL)) {
4002 					SEGVN_VMSTAT_FLTVNPAGES(20);
4003 					err = FC_MAKE_ERR(EIO);
4004 					goto out;
4005 				}
4006 				if (btopr(va.va_size) >= btopr(off + pgsz)) {
4007 					SEGVN_VMSTAT_FLTVNPAGES(21);
4008 					err = FC_MAKE_ERR(ierr);
4009 					goto out;
4010 				}
4011 				if (btopr(va.va_size) <
4012 				    btopr(off + (eaddr - a))) {
4013 					SEGVN_VMSTAT_FLTVNPAGES(22);
4014 					err = FC_MAKE_ERR(ierr);
4015 					goto out;
4016 				}
4017 				if (brkcow || tron || type == F_SOFTLOCK) {
4018 					/* can't reduce map area */
4019 					SEGVN_VMSTAT_FLTVNPAGES(23);
4020 					vop_size_err = 1;
4021 					goto out;
4022 				}
4023 				SEGVN_VMSTAT_FLTVNPAGES(24);
4024 				ASSERT(szc != 0);
4025 				pszc = 0;
4026 				ierr = -1;
4027 				break;
4028 			}
4029 
4030 			if (amp != NULL) {
4031 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4032 				anon_array_enter(amp, aindx, &an_cookie);
4033 			}
4034 			if (amp != NULL &&
4035 			    anon_get_ptr(amp->ahp, aindx) != NULL) {
4036 				ulong_t taindx = P2ALIGN(aindx, maxpages);
4037 
4038 				SEGVN_VMSTAT_FLTVNPAGES(25);
4039 				ASSERT(anon_pages(amp->ahp, taindx,
4040 				    maxpages) == maxpages);
4041 				for (i = 0; i < pages; i++) {
4042 					page_unlock(ppa[i]);
4043 				}
4044 				anon_array_exit(&an_cookie);
4045 				ANON_LOCK_EXIT(&amp->a_rwlock);
4046 				if (pplist != NULL) {
4047 					page_free_replacement_page(pplist);
4048 					page_create_putback(pages);
4049 				}
4050 				SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4051 				if (szc < seg->s_szc) {
4052 					SEGVN_VMSTAT_FLTVNPAGES(26);
4053 					/*
4054 					 * For private segments SOFTLOCK
4055 					 * either always breaks cow (any rw
4056 					 * type except S_READ_NOCOW) or
4057 					 * address space is locked as writer
4058 					 * (S_READ_NOCOW case) and anon slots
4059 					 * can't show up on second check.
4060 					 * Therefore if we are here for
4061 					 * SOFTLOCK case it must be a cow
4062 					 * break but cow break never reduces
4063 					 * szc. text replication (tron) in
4064 					 * this case works as cow break.
4065 					 * Thus the assert below.
4066 					 */
4067 					ASSERT(!brkcow && !tron &&
4068 					    type != F_SOFTLOCK);
4069 					pszc = seg->s_szc;
4070 					ierr = -2;
4071 					break;
4072 				}
4073 				ASSERT(IS_P2ALIGNED(a, maxpgsz));
4074 				goto again;
4075 			}
4076 #ifdef DEBUG
4077 			if (amp != NULL) {
4078 				ulong_t taindx = P2ALIGN(aindx, maxpages);
4079 				ASSERT(!anon_pages(amp->ahp, taindx, maxpages));
4080 			}
4081 #endif /* DEBUG */
4082 
4083 			if (brkcow || tron) {
4084 				ASSERT(amp != NULL);
4085 				ASSERT(pplist == NULL);
4086 				ASSERT(szc == seg->s_szc);
4087 				ASSERT(IS_P2ALIGNED(a, maxpgsz));
4088 				ASSERT(IS_P2ALIGNED(aindx, maxpages));
4089 				SEGVN_VMSTAT_FLTVNPAGES(27);
4090 				ierr = anon_map_privatepages(amp, aindx, szc,
4091 				    seg, a, prot, ppa, vpage, segvn_anypgsz,
4092 				    tron ? PG_LOCAL : 0, svd->cred);
4093 				if (ierr != 0) {
4094 					SEGVN_VMSTAT_FLTVNPAGES(28);
4095 					anon_array_exit(&an_cookie);
4096 					ANON_LOCK_EXIT(&amp->a_rwlock);
4097 					SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4098 					err = FC_MAKE_ERR(ierr);
4099 					goto out;
4100 				}
4101 
4102 				ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4103 				/*
4104 				 * p_szc can't be changed for locked
4105 				 * swapfs pages.
4106 				 */
4107 				ASSERT(svd->rcookie ==
4108 				    HAT_INVALID_REGION_COOKIE);
4109 				hat_memload_array(hat, a, pgsz, ppa, prot,
4110 				    hat_flag);
4111 
4112 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4113 					SEGVN_VMSTAT_FLTVNPAGES(29);
4114 					for (i = 0; i < pages; i++) {
4115 						page_unlock(ppa[i]);
4116 					}
4117 				}
4118 				anon_array_exit(&an_cookie);
4119 				ANON_LOCK_EXIT(&amp->a_rwlock);
4120 				goto next;
4121 			}
4122 
4123 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
4124 			    (!svd->pageprot && svd->prot == (prot & vpprot)));
4125 
4126 			pfn = page_pptonum(ppa[0]);
4127 			/*
4128 			 * hat_page_demote() needs an SE_EXCL lock on one of
4129 			 * constituent page_t's and it decreases root's p_szc
4130 			 * last. This means if root's p_szc is equal szc and
4131 			 * all its constituent pages are locked
4132 			 * hat_page_demote() that could have changed p_szc to
4133 			 * szc is already done and no new have page_demote()
4134 			 * can start for this large page.
4135 			 */
4136 
4137 			/*
4138 			 * we need to make sure same mapping size is used for
4139 			 * the same address range if there's a possibility the
4140 			 * adddress is already mapped because hat layer panics
4141 			 * when translation is loaded for the range already
4142 			 * mapped with a different page size.  We achieve it
4143 			 * by always using largest page size possible subject
4144 			 * to the constraints of page size, segment page size
4145 			 * and page alignment.  Since mappings are invalidated
4146 			 * when those constraints change and make it
4147 			 * impossible to use previously used mapping size no
4148 			 * mapping size conflicts should happen.
4149 			 */
4150 
4151 		chkszc:
4152 			if ((pszc = ppa[0]->p_szc) == szc &&
4153 			    IS_P2ALIGNED(pfn, pages)) {
4154 
4155 				SEGVN_VMSTAT_FLTVNPAGES(30);
4156 #ifdef DEBUG
4157 				for (i = 0; i < pages; i++) {
4158 					ASSERT(PAGE_LOCKED(ppa[i]));
4159 					ASSERT(!PP_ISFREE(ppa[i]));
4160 					ASSERT(page_pptonum(ppa[i]) ==
4161 					    pfn + i);
4162 					ASSERT(ppa[i]->p_szc == szc);
4163 					ASSERT(ppa[i]->p_vnode == vp);
4164 					ASSERT(ppa[i]->p_offset ==
4165 					    off + (i << PAGESHIFT));
4166 				}
4167 #endif /* DEBUG */
4168 				/*
4169 				 * All pages are of szc we need and they are
4170 				 * all locked so they can't change szc. load
4171 				 * translations.
4172 				 *
4173 				 * if page got promoted since last check
4174 				 * we don't need pplist.
4175 				 */
4176 				if (pplist != NULL) {
4177 					page_free_replacement_page(pplist);
4178 					page_create_putback(pages);
4179 				}
4180 				if (PP_ISMIGRATE(ppa[0])) {
4181 					page_migrate(seg, a, ppa, pages);
4182 				}
4183 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4184 				    prot, vpprot);
4185 				if (!xhat) {
4186 					hat_memload_array_region(hat, a, pgsz,
4187 					    ppa, prot & vpprot, hat_flag,
4188 					    svd->rcookie);
4189 				} else {
4190 					/*
4191 					 * avoid large xhat mappings to FS
4192 					 * pages so that hat_page_demote()
4193 					 * doesn't need to check for xhat
4194 					 * large mappings.
4195 					 * Don't use regions with xhats.
4196 					 */
4197 					for (i = 0; i < pages; i++) {
4198 						hat_memload(hat,
4199 						    a + (i << PAGESHIFT),
4200 						    ppa[i], prot & vpprot,
4201 						    hat_flag);
4202 					}
4203 				}
4204 
4205 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4206 					for (i = 0; i < pages; i++) {
4207 						page_unlock(ppa[i]);
4208 					}
4209 				}
4210 				if (amp != NULL) {
4211 					anon_array_exit(&an_cookie);
4212 					ANON_LOCK_EXIT(&amp->a_rwlock);
4213 				}
4214 				goto next;
4215 			}
4216 
4217 			/*
4218 			 * See if upsize is possible.
4219 			 */
4220 			if (pszc > szc && szc < seg->s_szc &&
4221 			    (segvn_anypgsz_vnode || pszc >= seg->s_szc)) {
4222 				pgcnt_t aphase;
4223 				uint_t pszc1 = MIN(pszc, seg->s_szc);
4224 				ppgsz = page_get_pagesize(pszc1);
4225 				ppages = btop(ppgsz);
4226 				aphase = btop(P2PHASE((uintptr_t)a, ppgsz));
4227 
4228 				ASSERT(type != F_SOFTLOCK);
4229 
4230 				SEGVN_VMSTAT_FLTVNPAGES(31);
4231 				if (aphase != P2PHASE(pfn, ppages)) {
4232 					segvn_faultvnmpss_align_err4++;
4233 				} else {
4234 					SEGVN_VMSTAT_FLTVNPAGES(32);
4235 					if (pplist != NULL) {
4236 						page_t *pl = pplist;
4237 						page_free_replacement_page(pl);
4238 						page_create_putback(pages);
4239 					}
4240 					for (i = 0; i < pages; i++) {
4241 						page_unlock(ppa[i]);
4242 					}
4243 					if (amp != NULL) {
4244 						anon_array_exit(&an_cookie);
4245 						ANON_LOCK_EXIT(&amp->a_rwlock);
4246 					}
4247 					pszc = pszc1;
4248 					ierr = -2;
4249 					break;
4250 				}
4251 			}
4252 
4253 			/*
4254 			 * check if we should use smallest mapping size.
4255 			 */
4256 			upgrdfail = 0;
4257 			if (szc == 0 || xhat ||
4258 			    (pszc >= szc &&
4259 			    !IS_P2ALIGNED(pfn, pages)) ||
4260 			    (pszc < szc &&
4261 			    !segvn_full_szcpages(ppa, szc, &upgrdfail,
4262 			    &pszc))) {
4263 
4264 				if (upgrdfail && type != F_SOFTLOCK) {
4265 					/*
4266 					 * segvn_full_szcpages failed to lock
4267 					 * all pages EXCL. Size down.
4268 					 */
4269 					ASSERT(pszc < szc);
4270 
4271 					SEGVN_VMSTAT_FLTVNPAGES(33);
4272 
4273 					if (pplist != NULL) {
4274 						page_t *pl = pplist;
4275 						page_free_replacement_page(pl);
4276 						page_create_putback(pages);
4277 					}
4278 
4279 					for (i = 0; i < pages; i++) {
4280 						page_unlock(ppa[i]);
4281 					}
4282 					if (amp != NULL) {
4283 						anon_array_exit(&an_cookie);
4284 						ANON_LOCK_EXIT(&amp->a_rwlock);
4285 					}
4286 					ierr = -1;
4287 					break;
4288 				}
4289 				if (szc != 0 && !xhat && !upgrdfail) {
4290 					segvn_faultvnmpss_align_err5++;
4291 				}
4292 				SEGVN_VMSTAT_FLTVNPAGES(34);
4293 				if (pplist != NULL) {
4294 					page_free_replacement_page(pplist);
4295 					page_create_putback(pages);
4296 				}
4297 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4298 				    prot, vpprot);
4299 				if (upgrdfail && segvn_anypgsz_vnode) {
4300 					/* SOFTLOCK case */
4301 					hat_memload_array_region(hat, a, pgsz,
4302 					    ppa, prot & vpprot, hat_flag,
4303 					    svd->rcookie);
4304 				} else {
4305 					for (i = 0; i < pages; i++) {
4306 						hat_memload_region(hat,
4307 						    a + (i << PAGESHIFT),
4308 						    ppa[i], prot & vpprot,
4309 						    hat_flag, svd->rcookie);
4310 					}
4311 				}
4312 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4313 					for (i = 0; i < pages; i++) {
4314 						page_unlock(ppa[i]);
4315 					}
4316 				}
4317 				if (amp != NULL) {
4318 					anon_array_exit(&an_cookie);
4319 					ANON_LOCK_EXIT(&amp->a_rwlock);
4320 				}
4321 				goto next;
4322 			}
4323 
4324 			if (pszc == szc) {
4325 				/*
4326 				 * segvn_full_szcpages() upgraded pages szc.
4327 				 */
4328 				ASSERT(pszc == ppa[0]->p_szc);
4329 				ASSERT(IS_P2ALIGNED(pfn, pages));
4330 				goto chkszc;
4331 			}
4332 
4333 			if (pszc > szc) {
4334 				kmutex_t *szcmtx;
4335 				SEGVN_VMSTAT_FLTVNPAGES(35);
4336 				/*
4337 				 * p_szc of ppa[0] can change since we haven't
4338 				 * locked all constituent pages. Call
4339 				 * page_lock_szc() to prevent szc changes.
4340 				 * This should be a rare case that happens when
4341 				 * multiple segments use a different page size
4342 				 * to map the same file offsets.
4343 				 */
4344 				szcmtx = page_szc_lock(ppa[0]);
4345 				pszc = ppa[0]->p_szc;
4346 				ASSERT(szcmtx != NULL || pszc == 0);
4347 				ASSERT(ppa[0]->p_szc <= pszc);
4348 				if (pszc <= szc) {
4349 					SEGVN_VMSTAT_FLTVNPAGES(36);
4350 					if (szcmtx != NULL) {
4351 						mutex_exit(szcmtx);
4352 					}
4353 					goto chkszc;
4354 				}
4355 				if (pplist != NULL) {
4356 					/*
4357 					 * page got promoted since last check.
4358 					 * we don't need preaalocated large
4359 					 * page.
4360 					 */
4361 					SEGVN_VMSTAT_FLTVNPAGES(37);
4362 					page_free_replacement_page(pplist);
4363 					page_create_putback(pages);
4364 				}
4365 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4366 				    prot, vpprot);
4367 				hat_memload_array_region(hat, a, pgsz, ppa,
4368 				    prot & vpprot, hat_flag, svd->rcookie);
4369 				mutex_exit(szcmtx);
4370 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4371 					for (i = 0; i < pages; i++) {
4372 						page_unlock(ppa[i]);
4373 					}
4374 				}
4375 				if (amp != NULL) {
4376 					anon_array_exit(&an_cookie);
4377 					ANON_LOCK_EXIT(&amp->a_rwlock);
4378 				}
4379 				goto next;
4380 			}
4381 
4382 			/*
4383 			 * if page got demoted since last check
4384 			 * we could have not allocated larger page.
4385 			 * allocate now.
4386 			 */
4387 			if (pplist == NULL &&
4388 			    page_alloc_pages(vp, seg, a, &pplist, NULL,
4389 			    szc, 0, 0) && type != F_SOFTLOCK) {
4390 				SEGVN_VMSTAT_FLTVNPAGES(38);
4391 				for (i = 0; i < pages; i++) {
4392 					page_unlock(ppa[i]);
4393 				}
4394 				if (amp != NULL) {
4395 					anon_array_exit(&an_cookie);
4396 					ANON_LOCK_EXIT(&amp->a_rwlock);
4397 				}
4398 				ierr = -1;
4399 				alloc_failed |= (1 << szc);
4400 				break;
4401 			}
4402 
4403 			SEGVN_VMSTAT_FLTVNPAGES(39);
4404 
4405 			if (pplist != NULL) {
4406 				segvn_relocate_pages(ppa, pplist);
4407 #ifdef DEBUG
4408 			} else {
4409 				ASSERT(type == F_SOFTLOCK);
4410 				SEGVN_VMSTAT_FLTVNPAGES(40);
4411 #endif /* DEBUG */
4412 			}
4413 
4414 			SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot);
4415 
4416 			if (pplist == NULL && segvn_anypgsz_vnode == 0) {
4417 				ASSERT(type == F_SOFTLOCK);
4418 				for (i = 0; i < pages; i++) {
4419 					ASSERT(ppa[i]->p_szc < szc);
4420 					hat_memload_region(hat,
4421 					    a + (i << PAGESHIFT),
4422 					    ppa[i], prot & vpprot, hat_flag,
4423 					    svd->rcookie);
4424 				}
4425 			} else {
4426 				ASSERT(pplist != NULL || type == F_SOFTLOCK);
4427 				hat_memload_array_region(hat, a, pgsz, ppa,
4428 				    prot & vpprot, hat_flag, svd->rcookie);
4429 			}
4430 			if (!(hat_flag & HAT_LOAD_LOCK)) {
4431 				for (i = 0; i < pages; i++) {
4432 					ASSERT(PAGE_SHARED(ppa[i]));
4433 					page_unlock(ppa[i]);
4434 				}
4435 			}
4436 			if (amp != NULL) {
4437 				anon_array_exit(&an_cookie);
4438 				ANON_LOCK_EXIT(&amp->a_rwlock);
4439 			}
4440 
4441 		next:
4442 			if (vpage != NULL) {
4443 				vpage += pages;
4444 			}
4445 			adjszc_chk = 1;
4446 		}
4447 		if (a == lpgeaddr)
4448 			break;
4449 		ASSERT(a < lpgeaddr);
4450 
4451 		ASSERT(!brkcow && !tron && type != F_SOFTLOCK);
4452 
4453 		/*
4454 		 * ierr == -1 means we failed to map with a large page.
4455 		 * (either due to allocation/relocation failures or
4456 		 * misalignment with other mappings to this file.
4457 		 *
4458 		 * ierr == -2 means some other thread allocated a large page
4459 		 * after we gave up tp map with a large page.  retry with
4460 		 * larger mapping.
4461 		 */
4462 		ASSERT(ierr == -1 || ierr == -2);
4463 		ASSERT(ierr == -2 || szc != 0);
4464 		ASSERT(ierr == -1 || szc < seg->s_szc);
4465 		if (ierr == -2) {
4466 			SEGVN_VMSTAT_FLTVNPAGES(41);
4467 			ASSERT(pszc > szc && pszc <= seg->s_szc);
4468 			szc = pszc;
4469 		} else if (segvn_anypgsz_vnode) {
4470 			SEGVN_VMSTAT_FLTVNPAGES(42);
4471 			szc--;
4472 		} else {
4473 			SEGVN_VMSTAT_FLTVNPAGES(43);
4474 			ASSERT(pszc < szc);
4475 			/*
4476 			 * other process created pszc large page.
4477 			 * but we still have to drop to 0 szc.
4478 			 */
4479 			szc = 0;
4480 		}
4481 
4482 		pgsz = page_get_pagesize(szc);
4483 		pages = btop(pgsz);
4484 		if (ierr == -2) {
4485 			/*
4486 			 * Size up case. Note lpgaddr may only be needed for
4487 			 * softlock case so we don't adjust it here.
4488 			 */
4489 			a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4490 			ASSERT(a >= lpgaddr);
4491 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4492 			off = svd->offset + (uintptr_t)(a - seg->s_base);
4493 			aindx = svd->anon_index + seg_page(seg, a);
4494 			vpage = (svd->vpage != NULL) ?
4495 			    &svd->vpage[seg_page(seg, a)] : NULL;
4496 		} else {
4497 			/*
4498 			 * Size down case. Note lpgaddr may only be needed for
4499 			 * softlock case so we don't adjust it here.
4500 			 */
4501 			ASSERT(IS_P2ALIGNED(a, pgsz));
4502 			ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4503 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4504 			ASSERT(a < lpgeaddr);
4505 			if (a < addr) {
4506 				SEGVN_VMSTAT_FLTVNPAGES(44);
4507 				/*
4508 				 * The beginning of the large page region can
4509 				 * be pulled to the right to make a smaller
4510 				 * region. We haven't yet faulted a single
4511 				 * page.
4512 				 */
4513 				a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4514 				ASSERT(a >= lpgaddr);
4515 				off = svd->offset +
4516 				    (uintptr_t)(a - seg->s_base);
4517 				aindx = svd->anon_index + seg_page(seg, a);
4518 				vpage = (svd->vpage != NULL) ?
4519 				    &svd->vpage[seg_page(seg, a)] : NULL;
4520 			}
4521 		}
4522 	}
4523 out:
4524 	kmem_free(ppa, ppasize);
4525 	if (!err && !vop_size_err) {
4526 		SEGVN_VMSTAT_FLTVNPAGES(45);
4527 		return (0);
4528 	}
4529 	if (type == F_SOFTLOCK && a > lpgaddr) {
4530 		SEGVN_VMSTAT_FLTVNPAGES(46);
4531 		segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4532 	}
4533 	if (!vop_size_err) {
4534 		SEGVN_VMSTAT_FLTVNPAGES(47);
4535 		return (err);
4536 	}
4537 	ASSERT(brkcow || tron || type == F_SOFTLOCK);
4538 	/*
4539 	 * Large page end is mapped beyond the end of file and it's a cow
4540 	 * fault (can be a text replication induced cow) or softlock so we can't
4541 	 * reduce the map area.  For now just demote the segment. This should
4542 	 * really only happen if the end of the file changed after the mapping
4543 	 * was established since when large page segments are created we make
4544 	 * sure they don't extend beyond the end of the file.
4545 	 */
4546 	SEGVN_VMSTAT_FLTVNPAGES(48);
4547 
4548 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4549 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4550 	err = 0;
4551 	if (seg->s_szc != 0) {
4552 		segvn_fltvnpages_clrszc_cnt++;
4553 		ASSERT(svd->softlockcnt == 0);
4554 		err = segvn_clrszc(seg);
4555 		if (err != 0) {
4556 			segvn_fltvnpages_clrszc_err++;
4557 		}
4558 	}
4559 	ASSERT(err || seg->s_szc == 0);
4560 	SEGVN_LOCK_DOWNGRADE(seg->s_as, &svd->lock);
4561 	/* segvn_fault will do its job as if szc had been zero to begin with */
4562 	return (err == 0 ? IE_RETRY : FC_MAKE_ERR(err));
4563 }
4564 
4565 /*
4566  * This routine will attempt to fault in one large page.
4567  * it will use smaller pages if that fails.
4568  * It should only be called for pure anonymous segments.
4569  */
4570 static faultcode_t
4571 segvn_fault_anonpages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
4572     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
4573     caddr_t eaddr, int brkcow)
4574 {
4575 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4576 	struct anon_map *amp = svd->amp;
4577 	uchar_t segtype = svd->type;
4578 	uint_t szc = seg->s_szc;
4579 	size_t pgsz = page_get_pagesize(szc);
4580 	size_t maxpgsz = pgsz;
4581 	pgcnt_t pages = btop(pgsz);
4582 	uint_t ppaszc = szc;
4583 	caddr_t a = lpgaddr;
4584 	ulong_t aindx = svd->anon_index + seg_page(seg, a);
4585 	struct vpage *vpage = (svd->vpage != NULL) ?
4586 	    &svd->vpage[seg_page(seg, a)] : NULL;
4587 	page_t **ppa;
4588 	uint_t	ppa_szc;
4589 	faultcode_t err;
4590 	int ierr;
4591 	uint_t protchk, prot, vpprot;
4592 	ulong_t i;
4593 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
4594 	anon_sync_obj_t cookie;
4595 	int adjszc_chk;
4596 	int pgflags = (svd->tr_state == SEGVN_TR_ON) ? PG_LOCAL : 0;
4597 
4598 	ASSERT(szc != 0);
4599 	ASSERT(amp != NULL);
4600 	ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
4601 	ASSERT(!(svd->flags & MAP_NORESERVE));
4602 	ASSERT(type != F_SOFTUNLOCK);
4603 	ASSERT(IS_P2ALIGNED(a, maxpgsz));
4604 	ASSERT(!brkcow || svd->tr_state == SEGVN_TR_OFF);
4605 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
4606 
4607 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
4608 
4609 	VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltanpages[0]);
4610 	VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltanpages[1]);
4611 
4612 	if (svd->flags & MAP_TEXT) {
4613 		hat_flag |= HAT_LOAD_TEXT;
4614 	}
4615 
4616 	if (svd->pageprot) {
4617 		switch (rw) {
4618 		case S_READ:
4619 			protchk = PROT_READ;
4620 			break;
4621 		case S_WRITE:
4622 			protchk = PROT_WRITE;
4623 			break;
4624 		case S_EXEC:
4625 			protchk = PROT_EXEC;
4626 			break;
4627 		case S_OTHER:
4628 		default:
4629 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4630 			break;
4631 		}
4632 		VM_STAT_ADD(segvnvmstats.fltanpages[2]);
4633 	} else {
4634 		prot = svd->prot;
4635 		/* caller has already done segment level protection check. */
4636 	}
4637 
4638 	ppa = kmem_cache_alloc(segvn_szc_cache[ppaszc], KM_SLEEP);
4639 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4640 	for (;;) {
4641 		adjszc_chk = 0;
4642 		for (; a < lpgeaddr; a += pgsz, aindx += pages) {
4643 			if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
4644 				VM_STAT_ADD(segvnvmstats.fltanpages[3]);
4645 				ASSERT(vpage != NULL);
4646 				prot = VPP_PROT(vpage);
4647 				ASSERT(sameprot(seg, a, maxpgsz));
4648 				if ((prot & protchk) == 0) {
4649 					err = FC_PROT;
4650 					goto error;
4651 				}
4652 			}
4653 			if (adjszc_chk && IS_P2ALIGNED(a, maxpgsz) &&
4654 			    pgsz < maxpgsz) {
4655 				ASSERT(a > lpgaddr);
4656 				szc = seg->s_szc;
4657 				pgsz = maxpgsz;
4658 				pages = btop(pgsz);
4659 				ASSERT(IS_P2ALIGNED(aindx, pages));
4660 				lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr,
4661 				    pgsz);
4662 			}
4663 			if (type == F_SOFTLOCK) {
4664 				atomic_add_long((ulong_t *)&svd->softlockcnt,
4665 				    pages);
4666 			}
4667 			anon_array_enter(amp, aindx, &cookie);
4668 			ppa_szc = (uint_t)-1;
4669 			ierr = anon_map_getpages(amp, aindx, szc, seg, a,
4670 			    prot, &vpprot, ppa, &ppa_szc, vpage, rw, brkcow,
4671 			    segvn_anypgsz, pgflags, svd->cred);
4672 			if (ierr != 0) {
4673 				anon_array_exit(&cookie);
4674 				VM_STAT_ADD(segvnvmstats.fltanpages[4]);
4675 				if (type == F_SOFTLOCK) {
4676 					atomic_add_long(
4677 					    (ulong_t *)&svd->softlockcnt,
4678 					    -pages);
4679 				}
4680 				if (ierr > 0) {
4681 					VM_STAT_ADD(segvnvmstats.fltanpages[6]);
4682 					err = FC_MAKE_ERR(ierr);
4683 					goto error;
4684 				}
4685 				break;
4686 			}
4687 
4688 			ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4689 
4690 			ASSERT(segtype == MAP_SHARED ||
4691 			    ppa[0]->p_szc <= szc);
4692 			ASSERT(segtype == MAP_PRIVATE ||
4693 			    ppa[0]->p_szc >= szc);
4694 
4695 			/*
4696 			 * Handle pages that have been marked for migration
4697 			 */
4698 			if (lgrp_optimizations())
4699 				page_migrate(seg, a, ppa, pages);
4700 
4701 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
4702 
4703 			if (segtype == MAP_SHARED) {
4704 				vpprot |= PROT_WRITE;
4705 			}
4706 
4707 			hat_memload_array(hat, a, pgsz, ppa,
4708 			    prot & vpprot, hat_flag);
4709 
4710 			if (hat_flag & HAT_LOAD_LOCK) {
4711 				VM_STAT_ADD(segvnvmstats.fltanpages[7]);
4712 			} else {
4713 				VM_STAT_ADD(segvnvmstats.fltanpages[8]);
4714 				for (i = 0; i < pages; i++)
4715 					page_unlock(ppa[i]);
4716 			}
4717 			if (vpage != NULL)
4718 				vpage += pages;
4719 
4720 			anon_array_exit(&cookie);
4721 			adjszc_chk = 1;
4722 		}
4723 		if (a == lpgeaddr)
4724 			break;
4725 		ASSERT(a < lpgeaddr);
4726 		/*
4727 		 * ierr == -1 means we failed to allocate a large page.
4728 		 * so do a size down operation.
4729 		 *
4730 		 * ierr == -2 means some other process that privately shares
4731 		 * pages with this process has allocated a larger page and we
4732 		 * need to retry with larger pages. So do a size up
4733 		 * operation. This relies on the fact that large pages are
4734 		 * never partially shared i.e. if we share any constituent
4735 		 * page of a large page with another process we must share the
4736 		 * entire large page. Note this cannot happen for SOFTLOCK
4737 		 * case, unless current address (a) is at the beginning of the
4738 		 * next page size boundary because the other process couldn't
4739 		 * have relocated locked pages.
4740 		 */
4741 		ASSERT(ierr == -1 || ierr == -2);
4742 
4743 		if (segvn_anypgsz) {
4744 			ASSERT(ierr == -2 || szc != 0);
4745 			ASSERT(ierr == -1 || szc < seg->s_szc);
4746 			szc = (ierr == -1) ? szc - 1 : szc + 1;
4747 		} else {
4748 			/*
4749 			 * For non COW faults and segvn_anypgsz == 0
4750 			 * we need to be careful not to loop forever
4751 			 * if existing page is found with szc other
4752 			 * than 0 or seg->s_szc. This could be due
4753 			 * to page relocations on behalf of DR or
4754 			 * more likely large page creation. For this
4755 			 * case simply re-size to existing page's szc
4756 			 * if returned by anon_map_getpages().
4757 			 */
4758 			if (ppa_szc == (uint_t)-1) {
4759 				szc = (ierr == -1) ? 0 : seg->s_szc;
4760 			} else {
4761 				ASSERT(ppa_szc <= seg->s_szc);
4762 				ASSERT(ierr == -2 || ppa_szc < szc);
4763 				ASSERT(ierr == -1 || ppa_szc > szc);
4764 				szc = ppa_szc;
4765 			}
4766 		}
4767 
4768 		pgsz = page_get_pagesize(szc);
4769 		pages = btop(pgsz);
4770 		ASSERT(type != F_SOFTLOCK || ierr == -1 ||
4771 		    (IS_P2ALIGNED(a, pgsz) && IS_P2ALIGNED(lpgeaddr, pgsz)));
4772 		if (type == F_SOFTLOCK) {
4773 			/*
4774 			 * For softlocks we cannot reduce the fault area
4775 			 * (calculated based on the largest page size for this
4776 			 * segment) for size down and a is already next
4777 			 * page size aligned as assertted above for size
4778 			 * ups. Therefore just continue in case of softlock.
4779 			 */
4780 			VM_STAT_ADD(segvnvmstats.fltanpages[9]);
4781 			continue; /* keep lint happy */
4782 		} else if (ierr == -2) {
4783 
4784 			/*
4785 			 * Size up case. Note lpgaddr may only be needed for
4786 			 * softlock case so we don't adjust it here.
4787 			 */
4788 			VM_STAT_ADD(segvnvmstats.fltanpages[10]);
4789 			a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4790 			ASSERT(a >= lpgaddr);
4791 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4792 			aindx = svd->anon_index + seg_page(seg, a);
4793 			vpage = (svd->vpage != NULL) ?
4794 			    &svd->vpage[seg_page(seg, a)] : NULL;
4795 		} else {
4796 			/*
4797 			 * Size down case. Note lpgaddr may only be needed for
4798 			 * softlock case so we don't adjust it here.
4799 			 */
4800 			VM_STAT_ADD(segvnvmstats.fltanpages[11]);
4801 			ASSERT(IS_P2ALIGNED(a, pgsz));
4802 			ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4803 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4804 			ASSERT(a < lpgeaddr);
4805 			if (a < addr) {
4806 				/*
4807 				 * The beginning of the large page region can
4808 				 * be pulled to the right to make a smaller
4809 				 * region. We haven't yet faulted a single
4810 				 * page.
4811 				 */
4812 				VM_STAT_ADD(segvnvmstats.fltanpages[12]);
4813 				a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4814 				ASSERT(a >= lpgaddr);
4815 				aindx = svd->anon_index + seg_page(seg, a);
4816 				vpage = (svd->vpage != NULL) ?
4817 				    &svd->vpage[seg_page(seg, a)] : NULL;
4818 			}
4819 		}
4820 	}
4821 	VM_STAT_ADD(segvnvmstats.fltanpages[13]);
4822 	ANON_LOCK_EXIT(&amp->a_rwlock);
4823 	kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4824 	return (0);
4825 error:
4826 	VM_STAT_ADD(segvnvmstats.fltanpages[14]);
4827 	ANON_LOCK_EXIT(&amp->a_rwlock);
4828 	kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4829 	if (type == F_SOFTLOCK && a > lpgaddr) {
4830 		VM_STAT_ADD(segvnvmstats.fltanpages[15]);
4831 		segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4832 	}
4833 	return (err);
4834 }
4835 
4836 int fltadvice = 1;	/* set to free behind pages for sequential access */
4837 
4838 /*
4839  * This routine is called via a machine specific fault handling routine.
4840  * It is also called by software routines wishing to lock or unlock
4841  * a range of addresses.
4842  *
4843  * Here is the basic algorithm:
4844  *	If unlocking
4845  *		Call segvn_softunlock
4846  *		Return
4847  *	endif
4848  *	Checking and set up work
4849  *	If we will need some non-anonymous pages
4850  *		Call VOP_GETPAGE over the range of non-anonymous pages
4851  *	endif
4852  *	Loop over all addresses requested
4853  *		Call segvn_faultpage passing in page list
4854  *		    to load up translations and handle anonymous pages
4855  *	endloop
4856  *	Load up translation to any additional pages in page list not
4857  *	    already handled that fit into this segment
4858  */
4859 static faultcode_t
4860 segvn_fault(struct hat *hat, struct seg *seg, caddr_t addr, size_t len,
4861     enum fault_type type, enum seg_rw rw)
4862 {
4863 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4864 	page_t **plp, **ppp, *pp;
4865 	u_offset_t off;
4866 	caddr_t a;
4867 	struct vpage *vpage;
4868 	uint_t vpprot, prot;
4869 	int err;
4870 	page_t *pl[PVN_GETPAGE_NUM + 1];
4871 	size_t plsz, pl_alloc_sz;
4872 	size_t page;
4873 	ulong_t anon_index;
4874 	struct anon_map *amp;
4875 	int dogetpage = 0;
4876 	caddr_t	lpgaddr, lpgeaddr;
4877 	size_t pgsz;
4878 	anon_sync_obj_t cookie;
4879 	int brkcow = BREAK_COW_SHARE(rw, type, svd->type);
4880 
4881 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
4882 	ASSERT(svd->amp == NULL || svd->rcookie == HAT_INVALID_REGION_COOKIE);
4883 
4884 	/*
4885 	 * First handle the easy stuff
4886 	 */
4887 	if (type == F_SOFTUNLOCK) {
4888 		if (rw == S_READ_NOCOW) {
4889 			rw = S_READ;
4890 			ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
4891 		}
4892 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4893 		pgsz = (seg->s_szc == 0) ? PAGESIZE :
4894 		    page_get_pagesize(seg->s_szc);
4895 		VM_STAT_COND_ADD(pgsz > PAGESIZE, segvnvmstats.fltanpages[16]);
4896 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
4897 		segvn_softunlock(seg, lpgaddr, lpgeaddr - lpgaddr, rw);
4898 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4899 		return (0);
4900 	}
4901 
4902 	ASSERT(svd->tr_state == SEGVN_TR_OFF ||
4903 	    !HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
4904 	if (brkcow == 0) {
4905 		if (svd->tr_state == SEGVN_TR_INIT) {
4906 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4907 			if (svd->tr_state == SEGVN_TR_INIT) {
4908 				ASSERT(svd->vp != NULL && svd->amp == NULL);
4909 				ASSERT(svd->flags & MAP_TEXT);
4910 				ASSERT(svd->type == MAP_PRIVATE);
4911 				segvn_textrepl(seg);
4912 				ASSERT(svd->tr_state != SEGVN_TR_INIT);
4913 				ASSERT(svd->tr_state != SEGVN_TR_ON ||
4914 				    svd->amp != NULL);
4915 			}
4916 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4917 		}
4918 	} else if (svd->tr_state != SEGVN_TR_OFF) {
4919 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4920 
4921 		if (rw == S_WRITE && svd->tr_state != SEGVN_TR_OFF) {
4922 			ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
4923 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4924 			return (FC_PROT);
4925 		}
4926 
4927 		if (svd->tr_state == SEGVN_TR_ON) {
4928 			ASSERT(svd->vp != NULL && svd->amp != NULL);
4929 			segvn_textunrepl(seg, 0);
4930 			ASSERT(svd->amp == NULL &&
4931 			    svd->tr_state == SEGVN_TR_OFF);
4932 		} else if (svd->tr_state != SEGVN_TR_OFF) {
4933 			svd->tr_state = SEGVN_TR_OFF;
4934 		}
4935 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
4936 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4937 	}
4938 
4939 top:
4940 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4941 
4942 	/*
4943 	 * If we have the same protections for the entire segment,
4944 	 * insure that the access being attempted is legitimate.
4945 	 */
4946 
4947 	if (svd->pageprot == 0) {
4948 		uint_t protchk;
4949 
4950 		switch (rw) {
4951 		case S_READ:
4952 		case S_READ_NOCOW:
4953 			protchk = PROT_READ;
4954 			break;
4955 		case S_WRITE:
4956 			protchk = PROT_WRITE;
4957 			break;
4958 		case S_EXEC:
4959 			protchk = PROT_EXEC;
4960 			break;
4961 		case S_OTHER:
4962 		default:
4963 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4964 			break;
4965 		}
4966 
4967 		if ((svd->prot & protchk) == 0) {
4968 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4969 			return (FC_PROT);	/* illegal access type */
4970 		}
4971 	}
4972 
4973 	if (brkcow && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
4974 		/* this must be SOFTLOCK S_READ fault */
4975 		ASSERT(svd->amp == NULL);
4976 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
4977 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4978 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4979 		if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
4980 			/*
4981 			 * this must be the first ever non S_READ_NOCOW
4982 			 * softlock for this segment.
4983 			 */
4984 			ASSERT(svd->softlockcnt == 0);
4985 			hat_leave_region(seg->s_as->a_hat, svd->rcookie,
4986 			    HAT_REGION_TEXT);
4987 			svd->rcookie = HAT_INVALID_REGION_COOKIE;
4988 		}
4989 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4990 		goto top;
4991 	}
4992 
4993 	/*
4994 	 * We can't allow the long term use of softlocks for vmpss segments,
4995 	 * because in some file truncation cases we should be able to demote
4996 	 * the segment, which requires that there are no softlocks.  The
4997 	 * only case where it's ok to allow a SOFTLOCK fault against a vmpss
4998 	 * segment is S_READ_NOCOW, where the caller holds the address space
4999 	 * locked as writer and calls softunlock before dropping the as lock.
5000 	 * S_READ_NOCOW is used by /proc to read memory from another user.
5001 	 *
5002 	 * Another deadlock between SOFTLOCK and file truncation can happen
5003 	 * because segvn_fault_vnodepages() calls the FS one pagesize at
5004 	 * a time. A second VOP_GETPAGE() call by segvn_fault_vnodepages()
5005 	 * can cause a deadlock because the first set of page_t's remain
5006 	 * locked SE_SHARED.  To avoid this, we demote segments on a first
5007 	 * SOFTLOCK if they have a length greater than the segment's
5008 	 * page size.
5009 	 *
5010 	 * So for now, we only avoid demoting a segment on a SOFTLOCK when
5011 	 * the access type is S_READ_NOCOW and the fault length is less than
5012 	 * or equal to the segment's page size. While this is quite restrictive,
5013 	 * it should be the most common case of SOFTLOCK against a vmpss
5014 	 * segment.
5015 	 *
5016 	 * For S_READ_NOCOW, it's safe not to do a copy on write because the
5017 	 * caller makes sure no COW will be caused by another thread for a
5018 	 * softlocked page.
5019 	 */
5020 	if (type == F_SOFTLOCK && svd->vp != NULL && seg->s_szc != 0) {
5021 		int demote = 0;
5022 
5023 		if (rw != S_READ_NOCOW) {
5024 			demote = 1;
5025 		}
5026 		if (!demote && len > PAGESIZE) {
5027 			pgsz = page_get_pagesize(seg->s_szc);
5028 			CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr,
5029 			    lpgeaddr);
5030 			if (lpgeaddr - lpgaddr > pgsz) {
5031 				demote = 1;
5032 			}
5033 		}
5034 
5035 		ASSERT(demote || AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5036 
5037 		if (demote) {
5038 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5039 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5040 			if (seg->s_szc != 0) {
5041 				segvn_vmpss_clrszc_cnt++;
5042 				ASSERT(svd->softlockcnt == 0);
5043 				err = segvn_clrszc(seg);
5044 				if (err) {
5045 					segvn_vmpss_clrszc_err++;
5046 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5047 					return (FC_MAKE_ERR(err));
5048 				}
5049 			}
5050 			ASSERT(seg->s_szc == 0);
5051 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5052 			goto top;
5053 		}
5054 	}
5055 
5056 	/*
5057 	 * Check to see if we need to allocate an anon_map structure.
5058 	 */
5059 	if (svd->amp == NULL && (svd->vp == NULL || brkcow)) {
5060 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5061 		/*
5062 		 * Drop the "read" lock on the segment and acquire
5063 		 * the "write" version since we have to allocate the
5064 		 * anon_map.
5065 		 */
5066 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5067 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5068 
5069 		if (svd->amp == NULL) {
5070 			svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
5071 			svd->amp->a_szc = seg->s_szc;
5072 		}
5073 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5074 
5075 		/*
5076 		 * Start all over again since segment protections
5077 		 * may have changed after we dropped the "read" lock.
5078 		 */
5079 		goto top;
5080 	}
5081 
5082 	/*
5083 	 * S_READ_NOCOW vs S_READ distinction was
5084 	 * only needed for the code above. After
5085 	 * that we treat it as S_READ.
5086 	 */
5087 	if (rw == S_READ_NOCOW) {
5088 		ASSERT(type == F_SOFTLOCK);
5089 		ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5090 		rw = S_READ;
5091 	}
5092 
5093 	amp = svd->amp;
5094 
5095 	/*
5096 	 * MADV_SEQUENTIAL work is ignored for large page segments.
5097 	 */
5098 	if (seg->s_szc != 0) {
5099 		pgsz = page_get_pagesize(seg->s_szc);
5100 		ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
5101 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
5102 		if (svd->vp == NULL) {
5103 			err = segvn_fault_anonpages(hat, seg, lpgaddr,
5104 			    lpgeaddr, type, rw, addr, addr + len, brkcow);
5105 		} else {
5106 			err = segvn_fault_vnodepages(hat, seg, lpgaddr,
5107 			    lpgeaddr, type, rw, addr, addr + len, brkcow);
5108 			if (err == IE_RETRY) {
5109 				ASSERT(seg->s_szc == 0);
5110 				ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
5111 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5112 				goto top;
5113 			}
5114 		}
5115 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5116 		return (err);
5117 	}
5118 
5119 	page = seg_page(seg, addr);
5120 	if (amp != NULL) {
5121 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5122 		anon_index = svd->anon_index + page;
5123 
5124 		if (type == F_PROT && rw == S_READ &&
5125 		    svd->tr_state == SEGVN_TR_OFF &&
5126 		    svd->type == MAP_PRIVATE && svd->pageprot == 0) {
5127 			size_t index = anon_index;
5128 			struct anon *ap;
5129 
5130 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5131 			/*
5132 			 * The fast path could apply to S_WRITE also, except
5133 			 * that the protection fault could be caused by lazy
5134 			 * tlb flush when ro->rw. In this case, the pte is
5135 			 * RW already. But RO in the other cpu's tlb causes
5136 			 * the fault. Since hat_chgprot won't do anything if
5137 			 * pte doesn't change, we may end up faulting
5138 			 * indefinitely until the RO tlb entry gets replaced.
5139 			 */
5140 			for (a = addr; a < addr + len; a += PAGESIZE, index++) {
5141 				anon_array_enter(amp, index, &cookie);
5142 				ap = anon_get_ptr(amp->ahp, index);
5143 				anon_array_exit(&cookie);
5144 				if ((ap == NULL) || (ap->an_refcnt != 1)) {
5145 					ANON_LOCK_EXIT(&amp->a_rwlock);
5146 					goto slow;
5147 				}
5148 			}
5149 			hat_chgprot(seg->s_as->a_hat, addr, len, svd->prot);
5150 			ANON_LOCK_EXIT(&amp->a_rwlock);
5151 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5152 			return (0);
5153 		}
5154 	}
5155 slow:
5156 
5157 	if (svd->vpage == NULL)
5158 		vpage = NULL;
5159 	else
5160 		vpage = &svd->vpage[page];
5161 
5162 	off = svd->offset + (uintptr_t)(addr - seg->s_base);
5163 
5164 	/*
5165 	 * If MADV_SEQUENTIAL has been set for the particular page we
5166 	 * are faulting on, free behind all pages in the segment and put
5167 	 * them on the free list.
5168 	 */
5169 
5170 	if ((page != 0) && fltadvice && svd->tr_state != SEGVN_TR_ON) {
5171 		struct vpage *vpp;
5172 		ulong_t fanon_index;
5173 		size_t fpage;
5174 		u_offset_t pgoff, fpgoff;
5175 		struct vnode *fvp;
5176 		struct anon *fap = NULL;
5177 
5178 		if (svd->advice == MADV_SEQUENTIAL ||
5179 		    (svd->pageadvice &&
5180 		    VPP_ADVICE(vpage) == MADV_SEQUENTIAL)) {
5181 			pgoff = off - PAGESIZE;
5182 			fpage = page - 1;
5183 			if (vpage != NULL)
5184 				vpp = &svd->vpage[fpage];
5185 			if (amp != NULL)
5186 				fanon_index = svd->anon_index + fpage;
5187 
5188 			while (pgoff > svd->offset) {
5189 				if (svd->advice != MADV_SEQUENTIAL &&
5190 				    (!svd->pageadvice || (vpage &&
5191 				    VPP_ADVICE(vpp) != MADV_SEQUENTIAL)))
5192 					break;
5193 
5194 				/*
5195 				 * If this is an anon page, we must find the
5196 				 * correct <vp, offset> for it
5197 				 */
5198 				fap = NULL;
5199 				if (amp != NULL) {
5200 					ANON_LOCK_ENTER(&amp->a_rwlock,
5201 					    RW_READER);
5202 					anon_array_enter(amp, fanon_index,
5203 					    &cookie);
5204 					fap = anon_get_ptr(amp->ahp,
5205 					    fanon_index);
5206 					if (fap != NULL) {
5207 						swap_xlate(fap, &fvp, &fpgoff);
5208 					} else {
5209 						fpgoff = pgoff;
5210 						fvp = svd->vp;
5211 					}
5212 					anon_array_exit(&cookie);
5213 					ANON_LOCK_EXIT(&amp->a_rwlock);
5214 				} else {
5215 					fpgoff = pgoff;
5216 					fvp = svd->vp;
5217 				}
5218 				if (fvp == NULL)
5219 					break;	/* XXX */
5220 				/*
5221 				 * Skip pages that are free or have an
5222 				 * "exclusive" lock.
5223 				 */
5224 				pp = page_lookup_nowait(fvp, fpgoff, SE_SHARED);
5225 				if (pp == NULL)
5226 					break;
5227 				/*
5228 				 * We don't need the page_struct_lock to test
5229 				 * as this is only advisory; even if we
5230 				 * acquire it someone might race in and lock
5231 				 * the page after we unlock and before the
5232 				 * PUTPAGE, then VOP_PUTPAGE will do nothing.
5233 				 */
5234 				if (pp->p_lckcnt == 0 && pp->p_cowcnt == 0) {
5235 					/*
5236 					 * Hold the vnode before releasing
5237 					 * the page lock to prevent it from
5238 					 * being freed and re-used by some
5239 					 * other thread.
5240 					 */
5241 					VN_HOLD(fvp);
5242 					page_unlock(pp);
5243 					/*
5244 					 * We should build a page list
5245 					 * to kluster putpages XXX
5246 					 */
5247 					(void) VOP_PUTPAGE(fvp,
5248 					    (offset_t)fpgoff, PAGESIZE,
5249 					    (B_DONTNEED|B_FREE|B_ASYNC),
5250 					    svd->cred, NULL);
5251 					VN_RELE(fvp);
5252 				} else {
5253 					/*
5254 					 * XXX - Should the loop terminate if
5255 					 * the page is `locked'?
5256 					 */
5257 					page_unlock(pp);
5258 				}
5259 				--vpp;
5260 				--fanon_index;
5261 				pgoff -= PAGESIZE;
5262 			}
5263 		}
5264 	}
5265 
5266 	plp = pl;
5267 	*plp = NULL;
5268 	pl_alloc_sz = 0;
5269 
5270 	/*
5271 	 * See if we need to call VOP_GETPAGE for
5272 	 * *any* of the range being faulted on.
5273 	 * We can skip all of this work if there
5274 	 * was no original vnode.
5275 	 */
5276 	if (svd->vp != NULL) {
5277 		u_offset_t vp_off;
5278 		size_t vp_len;
5279 		struct anon *ap;
5280 		vnode_t *vp;
5281 
5282 		vp_off = off;
5283 		vp_len = len;
5284 
5285 		if (amp == NULL)
5286 			dogetpage = 1;
5287 		else {
5288 			/*
5289 			 * Only acquire reader lock to prevent amp->ahp
5290 			 * from being changed.  It's ok to miss pages,
5291 			 * hence we don't do anon_array_enter
5292 			 */
5293 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5294 			ap = anon_get_ptr(amp->ahp, anon_index);
5295 
5296 			if (len <= PAGESIZE)
5297 				/* inline non_anon() */
5298 				dogetpage = (ap == NULL);
5299 			else
5300 				dogetpage = non_anon(amp->ahp, anon_index,
5301 				    &vp_off, &vp_len);
5302 			ANON_LOCK_EXIT(&amp->a_rwlock);
5303 		}
5304 
5305 		if (dogetpage) {
5306 			enum seg_rw arw;
5307 			struct as *as = seg->s_as;
5308 
5309 			if (len > ptob((sizeof (pl) / sizeof (pl[0])) - 1)) {
5310 				/*
5311 				 * Page list won't fit in local array,
5312 				 * allocate one of the needed size.
5313 				 */
5314 				pl_alloc_sz =
5315 				    (btop(len) + 1) * sizeof (page_t *);
5316 				plp = kmem_alloc(pl_alloc_sz, KM_SLEEP);
5317 				plp[0] = NULL;
5318 				plsz = len;
5319 			} else if (rw == S_WRITE && svd->type == MAP_PRIVATE ||
5320 			    svd->tr_state == SEGVN_TR_ON || rw == S_OTHER ||
5321 			    (((size_t)(addr + PAGESIZE) <
5322 			    (size_t)(seg->s_base + seg->s_size)) &&
5323 			    hat_probe(as->a_hat, addr + PAGESIZE))) {
5324 				/*
5325 				 * Ask VOP_GETPAGE to return the exact number
5326 				 * of pages if
5327 				 * (a) this is a COW fault, or
5328 				 * (b) this is a software fault, or
5329 				 * (c) next page is already mapped.
5330 				 */
5331 				plsz = len;
5332 			} else {
5333 				/*
5334 				 * Ask VOP_GETPAGE to return adjacent pages
5335 				 * within the segment.
5336 				 */
5337 				plsz = MIN((size_t)PVN_GETPAGE_SZ, (size_t)
5338 				    ((seg->s_base + seg->s_size) - addr));
5339 				ASSERT((addr + plsz) <=
5340 				    (seg->s_base + seg->s_size));
5341 			}
5342 
5343 			/*
5344 			 * Need to get some non-anonymous pages.
5345 			 * We need to make only one call to GETPAGE to do
5346 			 * this to prevent certain deadlocking conditions
5347 			 * when we are doing locking.  In this case
5348 			 * non_anon() should have picked up the smallest
5349 			 * range which includes all the non-anonymous
5350 			 * pages in the requested range.  We have to
5351 			 * be careful regarding which rw flag to pass in
5352 			 * because on a private mapping, the underlying
5353 			 * object is never allowed to be written.
5354 			 */
5355 			if (rw == S_WRITE && svd->type == MAP_PRIVATE) {
5356 				arw = S_READ;
5357 			} else {
5358 				arw = rw;
5359 			}
5360 			vp = svd->vp;
5361 			TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5362 			    "segvn_getpage:seg %p addr %p vp %p",
5363 			    seg, addr, vp);
5364 			err = VOP_GETPAGE(vp, (offset_t)vp_off, vp_len,
5365 			    &vpprot, plp, plsz, seg, addr + (vp_off - off), arw,
5366 			    svd->cred, NULL);
5367 			if (err) {
5368 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5369 				segvn_pagelist_rele(plp);
5370 				if (pl_alloc_sz)
5371 					kmem_free(plp, pl_alloc_sz);
5372 				return (FC_MAKE_ERR(err));
5373 			}
5374 			if (svd->type == MAP_PRIVATE)
5375 				vpprot &= ~PROT_WRITE;
5376 		}
5377 	}
5378 
5379 	/*
5380 	 * N.B. at this time the plp array has all the needed non-anon
5381 	 * pages in addition to (possibly) having some adjacent pages.
5382 	 */
5383 
5384 	/*
5385 	 * Always acquire the anon_array_lock to prevent
5386 	 * 2 threads from allocating separate anon slots for
5387 	 * the same "addr".
5388 	 *
5389 	 * If this is a copy-on-write fault and we don't already
5390 	 * have the anon_array_lock, acquire it to prevent the
5391 	 * fault routine from handling multiple copy-on-write faults
5392 	 * on the same "addr" in the same address space.
5393 	 *
5394 	 * Only one thread should deal with the fault since after
5395 	 * it is handled, the other threads can acquire a translation
5396 	 * to the newly created private page.  This prevents two or
5397 	 * more threads from creating different private pages for the
5398 	 * same fault.
5399 	 *
5400 	 * We grab "serialization" lock here if this is a MAP_PRIVATE segment
5401 	 * to prevent deadlock between this thread and another thread
5402 	 * which has soft-locked this page and wants to acquire serial_lock.
5403 	 * ( bug 4026339 )
5404 	 *
5405 	 * The fix for bug 4026339 becomes unnecessary when using the
5406 	 * locking scheme with per amp rwlock and a global set of hash
5407 	 * lock, anon_array_lock.  If we steal a vnode page when low
5408 	 * on memory and upgrad the page lock through page_rename,
5409 	 * then the page is PAGE_HANDLED, nothing needs to be done
5410 	 * for this page after returning from segvn_faultpage.
5411 	 *
5412 	 * But really, the page lock should be downgraded after
5413 	 * the stolen page is page_rename'd.
5414 	 */
5415 
5416 	if (amp != NULL)
5417 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5418 
5419 	/*
5420 	 * Ok, now loop over the address range and handle faults
5421 	 */
5422 	for (a = addr; a < addr + len; a += PAGESIZE, off += PAGESIZE) {
5423 		err = segvn_faultpage(hat, seg, a, off, vpage, plp, vpprot,
5424 		    type, rw, brkcow);
5425 		if (err) {
5426 			if (amp != NULL)
5427 				ANON_LOCK_EXIT(&amp->a_rwlock);
5428 			if (type == F_SOFTLOCK && a > addr) {
5429 				segvn_softunlock(seg, addr, (a - addr),
5430 				    S_OTHER);
5431 			}
5432 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5433 			segvn_pagelist_rele(plp);
5434 			if (pl_alloc_sz)
5435 				kmem_free(plp, pl_alloc_sz);
5436 			return (err);
5437 		}
5438 		if (vpage) {
5439 			vpage++;
5440 		} else if (svd->vpage) {
5441 			page = seg_page(seg, addr);
5442 			vpage = &svd->vpage[++page];
5443 		}
5444 	}
5445 
5446 	/* Didn't get pages from the underlying fs so we're done */
5447 	if (!dogetpage)
5448 		goto done;
5449 
5450 	/*
5451 	 * Now handle any other pages in the list returned.
5452 	 * If the page can be used, load up the translations now.
5453 	 * Note that the for loop will only be entered if "plp"
5454 	 * is pointing to a non-NULL page pointer which means that
5455 	 * VOP_GETPAGE() was called and vpprot has been initialized.
5456 	 */
5457 	if (svd->pageprot == 0)
5458 		prot = svd->prot & vpprot;
5459 
5460 
5461 	/*
5462 	 * Large Files: diff should be unsigned value because we started
5463 	 * supporting > 2GB segment sizes from 2.5.1 and when a
5464 	 * large file of size > 2GB gets mapped to address space
5465 	 * the diff value can be > 2GB.
5466 	 */
5467 
5468 	for (ppp = plp; (pp = *ppp) != NULL; ppp++) {
5469 		size_t diff;
5470 		struct anon *ap;
5471 		int anon_index;
5472 		anon_sync_obj_t cookie;
5473 		int hat_flag = HAT_LOAD_ADV;
5474 
5475 		if (svd->flags & MAP_TEXT) {
5476 			hat_flag |= HAT_LOAD_TEXT;
5477 		}
5478 
5479 		if (pp == PAGE_HANDLED)
5480 			continue;
5481 
5482 		if (svd->tr_state != SEGVN_TR_ON &&
5483 		    pp->p_offset >=  svd->offset &&
5484 		    pp->p_offset < svd->offset + seg->s_size) {
5485 
5486 			diff = pp->p_offset - svd->offset;
5487 
5488 			/*
5489 			 * Large Files: Following is the assertion
5490 			 * validating the above cast.
5491 			 */
5492 			ASSERT(svd->vp == pp->p_vnode);
5493 
5494 			page = btop(diff);
5495 			if (svd->pageprot)
5496 				prot = VPP_PROT(&svd->vpage[page]) & vpprot;
5497 
5498 			/*
5499 			 * Prevent other threads in the address space from
5500 			 * creating private pages (i.e., allocating anon slots)
5501 			 * while we are in the process of loading translations
5502 			 * to additional pages returned by the underlying
5503 			 * object.
5504 			 */
5505 			if (amp != NULL) {
5506 				anon_index = svd->anon_index + page;
5507 				anon_array_enter(amp, anon_index, &cookie);
5508 				ap = anon_get_ptr(amp->ahp, anon_index);
5509 			}
5510 			if ((amp == NULL) || (ap == NULL)) {
5511 				if (IS_VMODSORT(pp->p_vnode) ||
5512 				    enable_mbit_wa) {
5513 					if (rw == S_WRITE)
5514 						hat_setmod(pp);
5515 					else if (rw != S_OTHER &&
5516 					    !hat_ismod(pp))
5517 						prot &= ~PROT_WRITE;
5518 				}
5519 				/*
5520 				 * Skip mapping read ahead pages marked
5521 				 * for migration, so they will get migrated
5522 				 * properly on fault
5523 				 */
5524 				ASSERT(amp == NULL ||
5525 				    svd->rcookie == HAT_INVALID_REGION_COOKIE);
5526 				if ((prot & PROT_READ) && !PP_ISMIGRATE(pp)) {
5527 					hat_memload_region(hat,
5528 					    seg->s_base + diff,
5529 					    pp, prot, hat_flag,
5530 					    svd->rcookie);
5531 				}
5532 			}
5533 			if (amp != NULL)
5534 				anon_array_exit(&cookie);
5535 		}
5536 		page_unlock(pp);
5537 	}
5538 done:
5539 	if (amp != NULL)
5540 		ANON_LOCK_EXIT(&amp->a_rwlock);
5541 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5542 	if (pl_alloc_sz)
5543 		kmem_free(plp, pl_alloc_sz);
5544 	return (0);
5545 }
5546 
5547 /*
5548  * This routine is used to start I/O on pages asynchronously.  XXX it will
5549  * only create PAGESIZE pages. At fault time they will be relocated into
5550  * larger pages.
5551  */
5552 static faultcode_t
5553 segvn_faulta(struct seg *seg, caddr_t addr)
5554 {
5555 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5556 	int err;
5557 	struct anon_map *amp;
5558 	vnode_t *vp;
5559 
5560 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5561 
5562 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
5563 	if ((amp = svd->amp) != NULL) {
5564 		struct anon *ap;
5565 
5566 		/*
5567 		 * Reader lock to prevent amp->ahp from being changed.
5568 		 * This is advisory, it's ok to miss a page, so
5569 		 * we don't do anon_array_enter lock.
5570 		 */
5571 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5572 		if ((ap = anon_get_ptr(amp->ahp,
5573 		    svd->anon_index + seg_page(seg, addr))) != NULL) {
5574 
5575 			err = anon_getpage(&ap, NULL, NULL,
5576 			    0, seg, addr, S_READ, svd->cred);
5577 
5578 			ANON_LOCK_EXIT(&amp->a_rwlock);
5579 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5580 			if (err)
5581 				return (FC_MAKE_ERR(err));
5582 			return (0);
5583 		}
5584 		ANON_LOCK_EXIT(&amp->a_rwlock);
5585 	}
5586 
5587 	if (svd->vp == NULL) {
5588 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5589 		return (0);			/* zfod page - do nothing now */
5590 	}
5591 
5592 	vp = svd->vp;
5593 	TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5594 	    "segvn_getpage:seg %p addr %p vp %p", seg, addr, vp);
5595 	err = VOP_GETPAGE(vp,
5596 	    (offset_t)(svd->offset + (uintptr_t)(addr - seg->s_base)),
5597 	    PAGESIZE, NULL, NULL, 0, seg, addr,
5598 	    S_OTHER, svd->cred, NULL);
5599 
5600 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5601 	if (err)
5602 		return (FC_MAKE_ERR(err));
5603 	return (0);
5604 }
5605 
5606 static int
5607 segvn_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
5608 {
5609 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5610 	struct vpage *cvp, *svp, *evp;
5611 	struct vnode *vp;
5612 	size_t pgsz;
5613 	pgcnt_t pgcnt;
5614 	anon_sync_obj_t cookie;
5615 	int unload_done = 0;
5616 
5617 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5618 
5619 	if ((svd->maxprot & prot) != prot)
5620 		return (EACCES);			/* violated maxprot */
5621 
5622 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5623 
5624 	/* return if prot is the same */
5625 	if (!svd->pageprot && svd->prot == prot) {
5626 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5627 		return (0);
5628 	}
5629 
5630 	/*
5631 	 * Since we change protections we first have to flush the cache.
5632 	 * This makes sure all the pagelock calls have to recheck
5633 	 * protections.
5634 	 */
5635 	if (svd->softlockcnt > 0) {
5636 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
5637 
5638 		/*
5639 		 * If this is shared segment non 0 softlockcnt
5640 		 * means locked pages are still in use.
5641 		 */
5642 		if (svd->type == MAP_SHARED) {
5643 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5644 			return (EAGAIN);
5645 		}
5646 
5647 		/*
5648 		 * Since we do have the segvn writers lock nobody can fill
5649 		 * the cache with entries belonging to this seg during
5650 		 * the purge. The flush either succeeds or we still have
5651 		 * pending I/Os.
5652 		 */
5653 		segvn_purge(seg);
5654 		if (svd->softlockcnt > 0) {
5655 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5656 			return (EAGAIN);
5657 		}
5658 	}
5659 
5660 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
5661 		ASSERT(svd->amp == NULL);
5662 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
5663 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
5664 		    HAT_REGION_TEXT);
5665 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
5666 		unload_done = 1;
5667 	} else if (svd->tr_state == SEGVN_TR_INIT) {
5668 		svd->tr_state = SEGVN_TR_OFF;
5669 	} else if (svd->tr_state == SEGVN_TR_ON) {
5670 		ASSERT(svd->amp != NULL);
5671 		segvn_textunrepl(seg, 0);
5672 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
5673 		unload_done = 1;
5674 	}
5675 
5676 	if ((prot & PROT_WRITE) && svd->type == MAP_SHARED &&
5677 	    svd->vp != NULL && (svd->vp->v_flag & VVMEXEC)) {
5678 		ASSERT(vn_is_mapped(svd->vp, V_WRITE));
5679 		segvn_inval_trcache(svd->vp);
5680 	}
5681 	if (seg->s_szc != 0) {
5682 		int err;
5683 		pgsz = page_get_pagesize(seg->s_szc);
5684 		pgcnt = pgsz >> PAGESHIFT;
5685 		ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
5686 		if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
5687 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5688 			ASSERT(seg->s_base != addr || seg->s_size != len);
5689 			/*
5690 			 * If we are holding the as lock as a reader then
5691 			 * we need to return IE_RETRY and let the as
5692 			 * layer drop and re-acquire the lock as a writer.
5693 			 */
5694 			if (AS_READ_HELD(seg->s_as, &seg->s_as->a_lock))
5695 				return (IE_RETRY);
5696 			VM_STAT_ADD(segvnvmstats.demoterange[1]);
5697 			if (svd->type == MAP_PRIVATE || svd->vp != NULL) {
5698 				err = segvn_demote_range(seg, addr, len,
5699 				    SDR_END, 0);
5700 			} else {
5701 				uint_t szcvec = map_pgszcvec(seg->s_base,
5702 				    pgsz, (uintptr_t)seg->s_base,
5703 				    (svd->flags & MAP_TEXT), MAPPGSZC_SHM, 0);
5704 				err = segvn_demote_range(seg, addr, len,
5705 				    SDR_END, szcvec);
5706 			}
5707 			if (err == 0)
5708 				return (IE_RETRY);
5709 			if (err == ENOMEM)
5710 				return (IE_NOMEM);
5711 			return (err);
5712 		}
5713 	}
5714 
5715 
5716 	/*
5717 	 * If it's a private mapping and we're making it writable then we
5718 	 * may have to reserve the additional swap space now. If we are
5719 	 * making writable only a part of the segment then we use its vpage
5720 	 * array to keep a record of the pages for which we have reserved
5721 	 * swap. In this case we set the pageswap field in the segment's
5722 	 * segvn structure to record this.
5723 	 *
5724 	 * If it's a private mapping to a file (i.e., vp != NULL) and we're
5725 	 * removing write permission on the entire segment and we haven't
5726 	 * modified any pages, we can release the swap space.
5727 	 */
5728 	if (svd->type == MAP_PRIVATE) {
5729 		if (prot & PROT_WRITE) {
5730 			if (!(svd->flags & MAP_NORESERVE) &&
5731 			    !(svd->swresv && svd->pageswap == 0)) {
5732 				size_t sz = 0;
5733 
5734 				/*
5735 				 * Start by determining how much swap
5736 				 * space is required.
5737 				 */
5738 				if (addr == seg->s_base &&
5739 				    len == seg->s_size &&
5740 				    svd->pageswap == 0) {
5741 					/* The whole segment */
5742 					sz = seg->s_size;
5743 				} else {
5744 					/*
5745 					 * Make sure that the vpage array
5746 					 * exists, and make a note of the
5747 					 * range of elements corresponding
5748 					 * to len.
5749 					 */
5750 					segvn_vpage(seg);
5751 					svp = &svd->vpage[seg_page(seg, addr)];
5752 					evp = &svd->vpage[seg_page(seg,
5753 					    addr + len)];
5754 
5755 					if (svd->pageswap == 0) {
5756 						/*
5757 						 * This is the first time we've
5758 						 * asked for a part of this
5759 						 * segment, so we need to
5760 						 * reserve everything we've
5761 						 * been asked for.
5762 						 */
5763 						sz = len;
5764 					} else {
5765 						/*
5766 						 * We have to count the number
5767 						 * of pages required.
5768 						 */
5769 						for (cvp = svp;  cvp < evp;
5770 						    cvp++) {
5771 							if (!VPP_ISSWAPRES(cvp))
5772 								sz++;
5773 						}
5774 						sz <<= PAGESHIFT;
5775 					}
5776 				}
5777 
5778 				/* Try to reserve the necessary swap. */
5779 				if (anon_resv_zone(sz,
5780 				    seg->s_as->a_proc->p_zone) == 0) {
5781 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5782 					return (IE_NOMEM);
5783 				}
5784 
5785 				/*
5786 				 * Make a note of how much swap space
5787 				 * we've reserved.
5788 				 */
5789 				if (svd->pageswap == 0 && sz == seg->s_size) {
5790 					svd->swresv = sz;
5791 				} else {
5792 					ASSERT(svd->vpage != NULL);
5793 					svd->swresv += sz;
5794 					svd->pageswap = 1;
5795 					for (cvp = svp; cvp < evp; cvp++) {
5796 						if (!VPP_ISSWAPRES(cvp))
5797 							VPP_SETSWAPRES(cvp);
5798 					}
5799 				}
5800 			}
5801 		} else {
5802 			/*
5803 			 * Swap space is released only if this segment
5804 			 * does not map anonymous memory, since read faults
5805 			 * on such segments still need an anon slot to read
5806 			 * in the data.
5807 			 */
5808 			if (svd->swresv != 0 && svd->vp != NULL &&
5809 			    svd->amp == NULL && addr == seg->s_base &&
5810 			    len == seg->s_size && svd->pageprot == 0) {
5811 				ASSERT(svd->pageswap == 0);
5812 				anon_unresv_zone(svd->swresv,
5813 				    seg->s_as->a_proc->p_zone);
5814 				svd->swresv = 0;
5815 				TRACE_3(TR_FAC_VM, TR_ANON_PROC,
5816 				    "anon proc:%p %lu %u", seg, 0, 0);
5817 			}
5818 		}
5819 	}
5820 
5821 	if (addr == seg->s_base && len == seg->s_size && svd->vpage == NULL) {
5822 		if (svd->prot == prot) {
5823 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5824 			return (0);			/* all done */
5825 		}
5826 		svd->prot = (uchar_t)prot;
5827 	} else if (svd->type == MAP_PRIVATE) {
5828 		struct anon *ap = NULL;
5829 		page_t *pp;
5830 		u_offset_t offset, off;
5831 		struct anon_map *amp;
5832 		ulong_t anon_idx = 0;
5833 
5834 		/*
5835 		 * A vpage structure exists or else the change does not
5836 		 * involve the entire segment.  Establish a vpage structure
5837 		 * if none is there.  Then, for each page in the range,
5838 		 * adjust its individual permissions.  Note that write-
5839 		 * enabling a MAP_PRIVATE page can affect the claims for
5840 		 * locked down memory.  Overcommitting memory terminates
5841 		 * the operation.
5842 		 */
5843 		segvn_vpage(seg);
5844 		svd->pageprot = 1;
5845 		if ((amp = svd->amp) != NULL) {
5846 			anon_idx = svd->anon_index + seg_page(seg, addr);
5847 			ASSERT(seg->s_szc == 0 ||
5848 			    IS_P2ALIGNED(anon_idx, pgcnt));
5849 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5850 		}
5851 
5852 		offset = svd->offset + (uintptr_t)(addr - seg->s_base);
5853 		evp = &svd->vpage[seg_page(seg, addr + len)];
5854 
5855 		/*
5856 		 * See Statement at the beginning of segvn_lockop regarding
5857 		 * the way cowcnts and lckcnts are handled.
5858 		 */
5859 		for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5860 
5861 			if (seg->s_szc != 0) {
5862 				if (amp != NULL) {
5863 					anon_array_enter(amp, anon_idx,
5864 					    &cookie);
5865 				}
5866 				if (IS_P2ALIGNED(anon_idx, pgcnt) &&
5867 				    !segvn_claim_pages(seg, svp, offset,
5868 				    anon_idx, prot)) {
5869 					if (amp != NULL) {
5870 						anon_array_exit(&cookie);
5871 					}
5872 					break;
5873 				}
5874 				if (amp != NULL) {
5875 					anon_array_exit(&cookie);
5876 				}
5877 				anon_idx++;
5878 			} else {
5879 				if (amp != NULL) {
5880 					anon_array_enter(amp, anon_idx,
5881 					    &cookie);
5882 					ap = anon_get_ptr(amp->ahp, anon_idx++);
5883 				}
5884 
5885 				if (VPP_ISPPLOCK(svp) &&
5886 				    VPP_PROT(svp) != prot) {
5887 
5888 					if (amp == NULL || ap == NULL) {
5889 						vp = svd->vp;
5890 						off = offset;
5891 					} else
5892 						swap_xlate(ap, &vp, &off);
5893 					if (amp != NULL)
5894 						anon_array_exit(&cookie);
5895 
5896 					if ((pp = page_lookup(vp, off,
5897 					    SE_SHARED)) == NULL) {
5898 						panic("segvn_setprot: no page");
5899 						/*NOTREACHED*/
5900 					}
5901 					ASSERT(seg->s_szc == 0);
5902 					if ((VPP_PROT(svp) ^ prot) &
5903 					    PROT_WRITE) {
5904 						if (prot & PROT_WRITE) {
5905 							if (!page_addclaim(
5906 							    pp)) {
5907 								page_unlock(pp);
5908 								break;
5909 							}
5910 						} else {
5911 							if (!page_subclaim(
5912 							    pp)) {
5913 								page_unlock(pp);
5914 								break;
5915 							}
5916 						}
5917 					}
5918 					page_unlock(pp);
5919 				} else if (amp != NULL)
5920 					anon_array_exit(&cookie);
5921 			}
5922 			VPP_SETPROT(svp, prot);
5923 			offset += PAGESIZE;
5924 		}
5925 		if (amp != NULL)
5926 			ANON_LOCK_EXIT(&amp->a_rwlock);
5927 
5928 		/*
5929 		 * Did we terminate prematurely?  If so, simply unload
5930 		 * the translations to the things we've updated so far.
5931 		 */
5932 		if (svp != evp) {
5933 			if (unload_done) {
5934 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5935 				return (IE_NOMEM);
5936 			}
5937 			len = (svp - &svd->vpage[seg_page(seg, addr)]) *
5938 			    PAGESIZE;
5939 			ASSERT(seg->s_szc == 0 || IS_P2ALIGNED(len, pgsz));
5940 			if (len != 0)
5941 				hat_unload(seg->s_as->a_hat, addr,
5942 				    len, HAT_UNLOAD);
5943 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5944 			return (IE_NOMEM);
5945 		}
5946 	} else {
5947 		segvn_vpage(seg);
5948 		svd->pageprot = 1;
5949 		evp = &svd->vpage[seg_page(seg, addr + len)];
5950 		for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5951 			VPP_SETPROT(svp, prot);
5952 		}
5953 	}
5954 
5955 	if (unload_done) {
5956 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5957 		return (0);
5958 	}
5959 
5960 	if (((prot & PROT_WRITE) != 0 &&
5961 	    (svd->vp != NULL || svd->type == MAP_PRIVATE)) ||
5962 	    (prot & ~PROT_USER) == PROT_NONE) {
5963 		/*
5964 		 * Either private or shared data with write access (in
5965 		 * which case we need to throw out all former translations
5966 		 * so that we get the right translations set up on fault
5967 		 * and we don't allow write access to any copy-on-write pages
5968 		 * that might be around or to prevent write access to pages
5969 		 * representing holes in a file), or we don't have permission
5970 		 * to access the memory at all (in which case we have to
5971 		 * unload any current translations that might exist).
5972 		 */
5973 		hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
5974 	} else {
5975 		/*
5976 		 * A shared mapping or a private mapping in which write
5977 		 * protection is going to be denied - just change all the
5978 		 * protections over the range of addresses in question.
5979 		 * segvn does not support any other attributes other
5980 		 * than prot so we can use hat_chgattr.
5981 		 */
5982 		hat_chgattr(seg->s_as->a_hat, addr, len, prot);
5983 	}
5984 
5985 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5986 
5987 	return (0);
5988 }
5989 
5990 /*
5991  * segvn_setpagesize is called via SEGOP_SETPAGESIZE from as_setpagesize,
5992  * to determine if the seg is capable of mapping the requested szc.
5993  */
5994 static int
5995 segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
5996 {
5997 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5998 	struct segvn_data *nsvd;
5999 	struct anon_map *amp = svd->amp;
6000 	struct seg *nseg;
6001 	caddr_t eaddr = addr + len, a;
6002 	size_t pgsz = page_get_pagesize(szc);
6003 	pgcnt_t pgcnt = page_get_pagecnt(szc);
6004 	int err;
6005 	u_offset_t off = svd->offset + (uintptr_t)(addr - seg->s_base);
6006 	extern struct vnode kvp;
6007 
6008 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6009 	ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6010 
6011 	if (seg->s_szc == szc || segvn_lpg_disable != 0) {
6012 		return (0);
6013 	}
6014 
6015 	/*
6016 	 * addr should always be pgsz aligned but eaddr may be misaligned if
6017 	 * it's at the end of the segment.
6018 	 *
6019 	 * XXX we should assert this condition since as_setpagesize() logic
6020 	 * guarantees it.
6021 	 */
6022 	if (!IS_P2ALIGNED(addr, pgsz) ||
6023 	    (!IS_P2ALIGNED(eaddr, pgsz) &&
6024 	    eaddr != seg->s_base + seg->s_size)) {
6025 
6026 		segvn_setpgsz_align_err++;
6027 		return (EINVAL);
6028 	}
6029 
6030 	if (amp != NULL && svd->type == MAP_SHARED) {
6031 		ulong_t an_idx = svd->anon_index + seg_page(seg, addr);
6032 		if (!IS_P2ALIGNED(an_idx, pgcnt)) {
6033 
6034 			segvn_setpgsz_anon_align_err++;
6035 			return (EINVAL);
6036 		}
6037 	}
6038 
6039 	if ((svd->flags & MAP_NORESERVE) || seg->s_as == &kas ||
6040 	    szc > segvn_maxpgszc) {
6041 		return (EINVAL);
6042 	}
6043 
6044 	/* paranoid check */
6045 	if (svd->vp != NULL &&
6046 	    (IS_SWAPFSVP(svd->vp) || VN_ISKAS(svd->vp))) {
6047 		return (EINVAL);
6048 	}
6049 
6050 	if (seg->s_szc == 0 && svd->vp != NULL &&
6051 	    map_addr_vacalign_check(addr, off)) {
6052 		return (EINVAL);
6053 	}
6054 
6055 	/*
6056 	 * Check that protections are the same within new page
6057 	 * size boundaries.
6058 	 */
6059 	if (svd->pageprot) {
6060 		for (a = addr; a < eaddr; a += pgsz) {
6061 			if ((a + pgsz) > eaddr) {
6062 				if (!sameprot(seg, a, eaddr - a)) {
6063 					return (EINVAL);
6064 				}
6065 			} else {
6066 				if (!sameprot(seg, a, pgsz)) {
6067 					return (EINVAL);
6068 				}
6069 			}
6070 		}
6071 	}
6072 
6073 	/*
6074 	 * Since we are changing page size we first have to flush
6075 	 * the cache. This makes sure all the pagelock calls have
6076 	 * to recheck protections.
6077 	 */
6078 	if (svd->softlockcnt > 0) {
6079 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6080 
6081 		/*
6082 		 * If this is shared segment non 0 softlockcnt
6083 		 * means locked pages are still in use.
6084 		 */
6085 		if (svd->type == MAP_SHARED) {
6086 			return (EAGAIN);
6087 		}
6088 
6089 		/*
6090 		 * Since we do have the segvn writers lock nobody can fill
6091 		 * the cache with entries belonging to this seg during
6092 		 * the purge. The flush either succeeds or we still have
6093 		 * pending I/Os.
6094 		 */
6095 		segvn_purge(seg);
6096 		if (svd->softlockcnt > 0) {
6097 			return (EAGAIN);
6098 		}
6099 	}
6100 
6101 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6102 		ASSERT(svd->amp == NULL);
6103 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6104 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6105 		    HAT_REGION_TEXT);
6106 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
6107 	} else if (svd->tr_state == SEGVN_TR_INIT) {
6108 		svd->tr_state = SEGVN_TR_OFF;
6109 	} else if (svd->tr_state == SEGVN_TR_ON) {
6110 		ASSERT(svd->amp != NULL);
6111 		segvn_textunrepl(seg, 1);
6112 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6113 		amp = NULL;
6114 	}
6115 
6116 	/*
6117 	 * Operation for sub range of existing segment.
6118 	 */
6119 	if (addr != seg->s_base || eaddr != (seg->s_base + seg->s_size)) {
6120 		if (szc < seg->s_szc) {
6121 			VM_STAT_ADD(segvnvmstats.demoterange[2]);
6122 			err = segvn_demote_range(seg, addr, len, SDR_RANGE, 0);
6123 			if (err == 0) {
6124 				return (IE_RETRY);
6125 			}
6126 			if (err == ENOMEM) {
6127 				return (IE_NOMEM);
6128 			}
6129 			return (err);
6130 		}
6131 		if (addr != seg->s_base) {
6132 			nseg = segvn_split_seg(seg, addr);
6133 			if (eaddr != (nseg->s_base + nseg->s_size)) {
6134 				/* eaddr is szc aligned */
6135 				(void) segvn_split_seg(nseg, eaddr);
6136 			}
6137 			return (IE_RETRY);
6138 		}
6139 		if (eaddr != (seg->s_base + seg->s_size)) {
6140 			/* eaddr is szc aligned */
6141 			(void) segvn_split_seg(seg, eaddr);
6142 		}
6143 		return (IE_RETRY);
6144 	}
6145 
6146 	/*
6147 	 * Break any low level sharing and reset seg->s_szc to 0.
6148 	 */
6149 	if ((err = segvn_clrszc(seg)) != 0) {
6150 		if (err == ENOMEM) {
6151 			err = IE_NOMEM;
6152 		}
6153 		return (err);
6154 	}
6155 	ASSERT(seg->s_szc == 0);
6156 
6157 	/*
6158 	 * If the end of the current segment is not pgsz aligned
6159 	 * then attempt to concatenate with the next segment.
6160 	 */
6161 	if (!IS_P2ALIGNED(eaddr, pgsz)) {
6162 		nseg = AS_SEGNEXT(seg->s_as, seg);
6163 		if (nseg == NULL || nseg == seg || eaddr != nseg->s_base) {
6164 			return (ENOMEM);
6165 		}
6166 		if (nseg->s_ops != &segvn_ops) {
6167 			return (EINVAL);
6168 		}
6169 		nsvd = (struct segvn_data *)nseg->s_data;
6170 		if (nsvd->softlockcnt > 0) {
6171 			/*
6172 			 * If this is shared segment non 0 softlockcnt
6173 			 * means locked pages are still in use.
6174 			 */
6175 			if (nsvd->type == MAP_SHARED) {
6176 				return (EAGAIN);
6177 			}
6178 			segvn_purge(nseg);
6179 			if (nsvd->softlockcnt > 0) {
6180 				return (EAGAIN);
6181 			}
6182 		}
6183 		err = segvn_clrszc(nseg);
6184 		if (err == ENOMEM) {
6185 			err = IE_NOMEM;
6186 		}
6187 		if (err != 0) {
6188 			return (err);
6189 		}
6190 		ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6191 		err = segvn_concat(seg, nseg, 1);
6192 		if (err == -1) {
6193 			return (EINVAL);
6194 		}
6195 		if (err == -2) {
6196 			return (IE_NOMEM);
6197 		}
6198 		return (IE_RETRY);
6199 	}
6200 
6201 	/*
6202 	 * May need to re-align anon array to
6203 	 * new szc.
6204 	 */
6205 	if (amp != NULL) {
6206 		if (!IS_P2ALIGNED(svd->anon_index, pgcnt)) {
6207 			struct anon_hdr *nahp;
6208 
6209 			ASSERT(svd->type == MAP_PRIVATE);
6210 
6211 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6212 			ASSERT(amp->refcnt == 1);
6213 			nahp = anon_create(btop(amp->size), ANON_NOSLEEP);
6214 			if (nahp == NULL) {
6215 				ANON_LOCK_EXIT(&amp->a_rwlock);
6216 				return (IE_NOMEM);
6217 			}
6218 			if (anon_copy_ptr(amp->ahp, svd->anon_index,
6219 			    nahp, 0, btop(seg->s_size), ANON_NOSLEEP)) {
6220 				anon_release(nahp, btop(amp->size));
6221 				ANON_LOCK_EXIT(&amp->a_rwlock);
6222 				return (IE_NOMEM);
6223 			}
6224 			anon_release(amp->ahp, btop(amp->size));
6225 			amp->ahp = nahp;
6226 			svd->anon_index = 0;
6227 			ANON_LOCK_EXIT(&amp->a_rwlock);
6228 		}
6229 	}
6230 	if (svd->vp != NULL && szc != 0) {
6231 		struct vattr va;
6232 		u_offset_t eoffpage = svd->offset;
6233 		va.va_mask = AT_SIZE;
6234 		eoffpage += seg->s_size;
6235 		eoffpage = btopr(eoffpage);
6236 		if (VOP_GETATTR(svd->vp, &va, 0, svd->cred, NULL) != 0) {
6237 			segvn_setpgsz_getattr_err++;
6238 			return (EINVAL);
6239 		}
6240 		if (btopr(va.va_size) < eoffpage) {
6241 			segvn_setpgsz_eof_err++;
6242 			return (EINVAL);
6243 		}
6244 		if (amp != NULL) {
6245 			/*
6246 			 * anon_fill_cow_holes() may call VOP_GETPAGE().
6247 			 * don't take anon map lock here to avoid holding it
6248 			 * across VOP_GETPAGE() calls that may call back into
6249 			 * segvn for klsutering checks. We don't really need
6250 			 * anon map lock here since it's a private segment and
6251 			 * we hold as level lock as writers.
6252 			 */
6253 			if ((err = anon_fill_cow_holes(seg, seg->s_base,
6254 			    amp->ahp, svd->anon_index, svd->vp, svd->offset,
6255 			    seg->s_size, szc, svd->prot, svd->vpage,
6256 			    svd->cred)) != 0) {
6257 				return (EINVAL);
6258 			}
6259 		}
6260 		segvn_setvnode_mpss(svd->vp);
6261 	}
6262 
6263 	if (amp != NULL) {
6264 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6265 		if (svd->type == MAP_PRIVATE) {
6266 			amp->a_szc = szc;
6267 		} else if (szc > amp->a_szc) {
6268 			amp->a_szc = szc;
6269 		}
6270 		ANON_LOCK_EXIT(&amp->a_rwlock);
6271 	}
6272 
6273 	seg->s_szc = szc;
6274 
6275 	return (0);
6276 }
6277 
6278 static int
6279 segvn_clrszc(struct seg *seg)
6280 {
6281 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6282 	struct anon_map *amp = svd->amp;
6283 	size_t pgsz;
6284 	pgcnt_t pages;
6285 	int err = 0;
6286 	caddr_t a = seg->s_base;
6287 	caddr_t ea = a + seg->s_size;
6288 	ulong_t an_idx = svd->anon_index;
6289 	vnode_t *vp = svd->vp;
6290 	struct vpage *vpage = svd->vpage;
6291 	page_t *anon_pl[1 + 1], *pp;
6292 	struct anon *ap, *oldap;
6293 	uint_t prot = svd->prot, vpprot;
6294 	int pageflag = 0;
6295 
6296 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6297 	    SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
6298 	ASSERT(svd->softlockcnt == 0);
6299 
6300 	if (vp == NULL && amp == NULL) {
6301 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6302 		seg->s_szc = 0;
6303 		return (0);
6304 	}
6305 
6306 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6307 		ASSERT(svd->amp == NULL);
6308 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6309 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6310 		    HAT_REGION_TEXT);
6311 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
6312 	} else if (svd->tr_state == SEGVN_TR_ON) {
6313 		ASSERT(svd->amp != NULL);
6314 		segvn_textunrepl(seg, 1);
6315 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6316 		amp = NULL;
6317 	} else {
6318 		if (svd->tr_state != SEGVN_TR_OFF) {
6319 			ASSERT(svd->tr_state == SEGVN_TR_INIT);
6320 			svd->tr_state = SEGVN_TR_OFF;
6321 		}
6322 
6323 		/*
6324 		 * do HAT_UNLOAD_UNMAP since we are changing the pagesize.
6325 		 * unload argument is 0 when we are freeing the segment
6326 		 * and unload was already done.
6327 		 */
6328 		hat_unload(seg->s_as->a_hat, seg->s_base, seg->s_size,
6329 		    HAT_UNLOAD_UNMAP);
6330 	}
6331 
6332 	if (amp == NULL || svd->type == MAP_SHARED) {
6333 		seg->s_szc = 0;
6334 		return (0);
6335 	}
6336 
6337 	pgsz = page_get_pagesize(seg->s_szc);
6338 	pages = btop(pgsz);
6339 
6340 	/*
6341 	 * XXX anon rwlock is not really needed because this is a
6342 	 * private segment and we are writers.
6343 	 */
6344 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6345 
6346 	for (; a < ea; a += pgsz, an_idx += pages) {
6347 		if ((oldap = anon_get_ptr(amp->ahp, an_idx)) != NULL) {
6348 			ASSERT(vpage != NULL || svd->pageprot == 0);
6349 			if (vpage != NULL) {
6350 				ASSERT(sameprot(seg, a, pgsz));
6351 				prot = VPP_PROT(vpage);
6352 				pageflag = VPP_ISPPLOCK(vpage) ? LOCK_PAGE : 0;
6353 			}
6354 			if (seg->s_szc != 0) {
6355 				ASSERT(vp == NULL || anon_pages(amp->ahp,
6356 				    an_idx, pages) == pages);
6357 				if ((err = anon_map_demotepages(amp, an_idx,
6358 				    seg, a, prot, vpage, svd->cred)) != 0) {
6359 					goto out;
6360 				}
6361 			} else {
6362 				if (oldap->an_refcnt == 1) {
6363 					continue;
6364 				}
6365 				if ((err = anon_getpage(&oldap, &vpprot,
6366 				    anon_pl, PAGESIZE, seg, a, S_READ,
6367 				    svd->cred))) {
6368 					goto out;
6369 				}
6370 				if ((pp = anon_private(&ap, seg, a, prot,
6371 				    anon_pl[0], pageflag, svd->cred)) == NULL) {
6372 					err = ENOMEM;
6373 					goto out;
6374 				}
6375 				anon_decref(oldap);
6376 				(void) anon_set_ptr(amp->ahp, an_idx, ap,
6377 				    ANON_SLEEP);
6378 				page_unlock(pp);
6379 			}
6380 		}
6381 		vpage = (vpage == NULL) ? NULL : vpage + pages;
6382 	}
6383 
6384 	amp->a_szc = 0;
6385 	seg->s_szc = 0;
6386 out:
6387 	ANON_LOCK_EXIT(&amp->a_rwlock);
6388 	return (err);
6389 }
6390 
6391 static int
6392 segvn_claim_pages(
6393 	struct seg *seg,
6394 	struct vpage *svp,
6395 	u_offset_t off,
6396 	ulong_t anon_idx,
6397 	uint_t prot)
6398 {
6399 	pgcnt_t	pgcnt = page_get_pagecnt(seg->s_szc);
6400 	size_t ppasize = (pgcnt + 1) * sizeof (page_t *);
6401 	page_t	**ppa;
6402 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6403 	struct anon_map *amp = svd->amp;
6404 	struct vpage *evp = svp + pgcnt;
6405 	caddr_t addr = ((uintptr_t)(svp - svd->vpage) << PAGESHIFT)
6406 	    + seg->s_base;
6407 	struct anon *ap;
6408 	struct vnode *vp = svd->vp;
6409 	page_t *pp;
6410 	pgcnt_t pg_idx, i;
6411 	int err = 0;
6412 	anoff_t aoff;
6413 	int anon = (amp != NULL) ? 1 : 0;
6414 
6415 	ASSERT(svd->type == MAP_PRIVATE);
6416 	ASSERT(svd->vpage != NULL);
6417 	ASSERT(seg->s_szc != 0);
6418 	ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
6419 	ASSERT(amp == NULL || IS_P2ALIGNED(anon_idx, pgcnt));
6420 	ASSERT(sameprot(seg, addr, pgcnt << PAGESHIFT));
6421 
6422 	if (VPP_PROT(svp) == prot)
6423 		return (1);
6424 	if (!((VPP_PROT(svp) ^ prot) & PROT_WRITE))
6425 		return (1);
6426 
6427 	ppa = kmem_alloc(ppasize, KM_SLEEP);
6428 	if (anon && vp != NULL) {
6429 		if (anon_get_ptr(amp->ahp, anon_idx) == NULL) {
6430 			anon = 0;
6431 			ASSERT(!anon_pages(amp->ahp, anon_idx, pgcnt));
6432 		}
6433 		ASSERT(!anon ||
6434 		    anon_pages(amp->ahp, anon_idx, pgcnt) == pgcnt);
6435 	}
6436 
6437 	for (*ppa = NULL, pg_idx = 0; svp < evp; svp++, anon_idx++) {
6438 		if (!VPP_ISPPLOCK(svp))
6439 			continue;
6440 		if (anon) {
6441 			ap = anon_get_ptr(amp->ahp, anon_idx);
6442 			if (ap == NULL) {
6443 				panic("segvn_claim_pages: no anon slot");
6444 			}
6445 			swap_xlate(ap, &vp, &aoff);
6446 			off = (u_offset_t)aoff;
6447 		}
6448 		ASSERT(vp != NULL);
6449 		if ((pp = page_lookup(vp,
6450 		    (u_offset_t)off, SE_SHARED)) == NULL) {
6451 			panic("segvn_claim_pages: no page");
6452 		}
6453 		ppa[pg_idx++] = pp;
6454 		off += PAGESIZE;
6455 	}
6456 
6457 	if (ppa[0] == NULL) {
6458 		kmem_free(ppa, ppasize);
6459 		return (1);
6460 	}
6461 
6462 	ASSERT(pg_idx <= pgcnt);
6463 	ppa[pg_idx] = NULL;
6464 
6465 	if (prot & PROT_WRITE)
6466 		err = page_addclaim_pages(ppa);
6467 	else
6468 		err = page_subclaim_pages(ppa);
6469 
6470 	for (i = 0; i < pg_idx; i++) {
6471 		ASSERT(ppa[i] != NULL);
6472 		page_unlock(ppa[i]);
6473 	}
6474 
6475 	kmem_free(ppa, ppasize);
6476 	return (err);
6477 }
6478 
6479 /*
6480  * Returns right (upper address) segment if split occurred.
6481  * If the address is equal to the beginning or end of its segment it returns
6482  * the current segment.
6483  */
6484 static struct seg *
6485 segvn_split_seg(struct seg *seg, caddr_t addr)
6486 {
6487 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6488 	struct seg *nseg;
6489 	size_t nsize;
6490 	struct segvn_data *nsvd;
6491 
6492 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6493 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
6494 
6495 	ASSERT(addr >= seg->s_base);
6496 	ASSERT(addr <= seg->s_base + seg->s_size);
6497 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6498 
6499 	if (addr == seg->s_base || addr == seg->s_base + seg->s_size)
6500 		return (seg);
6501 
6502 	nsize = seg->s_base + seg->s_size - addr;
6503 	seg->s_size = addr - seg->s_base;
6504 	nseg = seg_alloc(seg->s_as, addr, nsize);
6505 	ASSERT(nseg != NULL);
6506 	nseg->s_ops = seg->s_ops;
6507 	nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
6508 	nseg->s_data = (void *)nsvd;
6509 	nseg->s_szc = seg->s_szc;
6510 	*nsvd = *svd;
6511 	ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6512 	nsvd->seg = nseg;
6513 	rw_init(&nsvd->lock, NULL, RW_DEFAULT, NULL);
6514 
6515 	if (nsvd->vp != NULL) {
6516 		VN_HOLD(nsvd->vp);
6517 		nsvd->offset = svd->offset +
6518 		    (uintptr_t)(nseg->s_base - seg->s_base);
6519 		if (nsvd->type == MAP_SHARED)
6520 			lgrp_shm_policy_init(NULL, nsvd->vp);
6521 	} else {
6522 		/*
6523 		 * The offset for an anonymous segment has no signifigance in
6524 		 * terms of an offset into a file. If we were to use the above
6525 		 * calculation instead, the structures read out of
6526 		 * /proc/<pid>/xmap would be more difficult to decipher since
6527 		 * it would be unclear whether two seemingly contiguous
6528 		 * prxmap_t structures represented different segments or a
6529 		 * single segment that had been split up into multiple prxmap_t
6530 		 * structures (e.g. if some part of the segment had not yet
6531 		 * been faulted in).
6532 		 */
6533 		nsvd->offset = 0;
6534 	}
6535 
6536 	ASSERT(svd->softlockcnt == 0);
6537 	ASSERT(svd->softlockcnt_sbase == 0);
6538 	ASSERT(svd->softlockcnt_send == 0);
6539 	crhold(svd->cred);
6540 
6541 	if (svd->vpage != NULL) {
6542 		size_t bytes = vpgtob(seg_pages(seg));
6543 		size_t nbytes = vpgtob(seg_pages(nseg));
6544 		struct vpage *ovpage = svd->vpage;
6545 
6546 		svd->vpage = kmem_alloc(bytes, KM_SLEEP);
6547 		bcopy(ovpage, svd->vpage, bytes);
6548 		nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
6549 		bcopy(ovpage + seg_pages(seg), nsvd->vpage, nbytes);
6550 		kmem_free(ovpage, bytes + nbytes);
6551 	}
6552 	if (svd->amp != NULL && svd->type == MAP_PRIVATE) {
6553 		struct anon_map *oamp = svd->amp, *namp;
6554 		struct anon_hdr *nahp;
6555 
6556 		ANON_LOCK_ENTER(&oamp->a_rwlock, RW_WRITER);
6557 		ASSERT(oamp->refcnt == 1);
6558 		nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
6559 		(void) anon_copy_ptr(oamp->ahp, svd->anon_index,
6560 		    nahp, 0, btop(seg->s_size), ANON_SLEEP);
6561 
6562 		namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
6563 		namp->a_szc = nseg->s_szc;
6564 		(void) anon_copy_ptr(oamp->ahp,
6565 		    svd->anon_index + btop(seg->s_size),
6566 		    namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
6567 		anon_release(oamp->ahp, btop(oamp->size));
6568 		oamp->ahp = nahp;
6569 		oamp->size = seg->s_size;
6570 		svd->anon_index = 0;
6571 		nsvd->amp = namp;
6572 		nsvd->anon_index = 0;
6573 		ANON_LOCK_EXIT(&oamp->a_rwlock);
6574 	} else if (svd->amp != NULL) {
6575 		pgcnt_t pgcnt = page_get_pagecnt(seg->s_szc);
6576 		ASSERT(svd->amp == nsvd->amp);
6577 		ASSERT(seg->s_szc <= svd->amp->a_szc);
6578 		nsvd->anon_index = svd->anon_index + seg_pages(seg);
6579 		ASSERT(IS_P2ALIGNED(nsvd->anon_index, pgcnt));
6580 		ANON_LOCK_ENTER(&svd->amp->a_rwlock, RW_WRITER);
6581 		svd->amp->refcnt++;
6582 		ANON_LOCK_EXIT(&svd->amp->a_rwlock);
6583 	}
6584 
6585 	/*
6586 	 * Split the amount of swap reserved.
6587 	 */
6588 	if (svd->swresv) {
6589 		/*
6590 		 * For MAP_NORESERVE, only allocate swap reserve for pages
6591 		 * being used.  Other segments get enough to cover whole
6592 		 * segment.
6593 		 */
6594 		if (svd->flags & MAP_NORESERVE) {
6595 			size_t	oswresv;
6596 
6597 			ASSERT(svd->amp);
6598 			oswresv = svd->swresv;
6599 			svd->swresv = ptob(anon_pages(svd->amp->ahp,
6600 			    svd->anon_index, btop(seg->s_size)));
6601 			nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
6602 			    nsvd->anon_index, btop(nseg->s_size)));
6603 			ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
6604 		} else {
6605 			if (svd->pageswap) {
6606 				svd->swresv = segvn_count_swap_by_vpages(seg);
6607 				ASSERT(nsvd->swresv >= svd->swresv);
6608 				nsvd->swresv -= svd->swresv;
6609 			} else {
6610 				ASSERT(svd->swresv == seg->s_size +
6611 				    nseg->s_size);
6612 				svd->swresv = seg->s_size;
6613 				nsvd->swresv = nseg->s_size;
6614 			}
6615 		}
6616 	}
6617 
6618 	return (nseg);
6619 }
6620 
6621 /*
6622  * called on memory operations (unmap, setprot, setpagesize) for a subset
6623  * of a large page segment to either demote the memory range (SDR_RANGE)
6624  * or the ends (SDR_END) by addr/len.
6625  *
6626  * returns 0 on success. returns errno, including ENOMEM, on failure.
6627  */
6628 static int
6629 segvn_demote_range(
6630 	struct seg *seg,
6631 	caddr_t addr,
6632 	size_t len,
6633 	int flag,
6634 	uint_t szcvec)
6635 {
6636 	caddr_t eaddr = addr + len;
6637 	caddr_t lpgaddr, lpgeaddr;
6638 	struct seg *nseg;
6639 	struct seg *badseg1 = NULL;
6640 	struct seg *badseg2 = NULL;
6641 	size_t pgsz;
6642 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6643 	int err;
6644 	uint_t szc = seg->s_szc;
6645 	uint_t tszcvec;
6646 
6647 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6648 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
6649 	ASSERT(szc != 0);
6650 	pgsz = page_get_pagesize(szc);
6651 	ASSERT(seg->s_base != addr || seg->s_size != len);
6652 	ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6653 	ASSERT(svd->softlockcnt == 0);
6654 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6655 	ASSERT(szcvec == 0 || (flag == SDR_END && svd->type == MAP_SHARED));
6656 
6657 	CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
6658 	ASSERT(flag == SDR_RANGE || eaddr < lpgeaddr || addr > lpgaddr);
6659 	if (flag == SDR_RANGE) {
6660 		/* demote entire range */
6661 		badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6662 		(void) segvn_split_seg(nseg, lpgeaddr);
6663 		ASSERT(badseg1->s_base == lpgaddr);
6664 		ASSERT(badseg1->s_size == lpgeaddr - lpgaddr);
6665 	} else if (addr != lpgaddr) {
6666 		ASSERT(flag == SDR_END);
6667 		badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6668 		if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz &&
6669 		    eaddr < lpgaddr + 2 * pgsz) {
6670 			(void) segvn_split_seg(nseg, lpgeaddr);
6671 			ASSERT(badseg1->s_base == lpgaddr);
6672 			ASSERT(badseg1->s_size == 2 * pgsz);
6673 		} else {
6674 			nseg = segvn_split_seg(nseg, lpgaddr + pgsz);
6675 			ASSERT(badseg1->s_base == lpgaddr);
6676 			ASSERT(badseg1->s_size == pgsz);
6677 			if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz) {
6678 				ASSERT(lpgeaddr - lpgaddr > 2 * pgsz);
6679 				nseg = segvn_split_seg(nseg, lpgeaddr - pgsz);
6680 				badseg2 = nseg;
6681 				(void) segvn_split_seg(nseg, lpgeaddr);
6682 				ASSERT(badseg2->s_base == lpgeaddr - pgsz);
6683 				ASSERT(badseg2->s_size == pgsz);
6684 			}
6685 		}
6686 	} else {
6687 		ASSERT(flag == SDR_END);
6688 		ASSERT(eaddr < lpgeaddr);
6689 		badseg1 = nseg = segvn_split_seg(seg, lpgeaddr - pgsz);
6690 		(void) segvn_split_seg(nseg, lpgeaddr);
6691 		ASSERT(badseg1->s_base == lpgeaddr - pgsz);
6692 		ASSERT(badseg1->s_size == pgsz);
6693 	}
6694 
6695 	ASSERT(badseg1 != NULL);
6696 	ASSERT(badseg1->s_szc == szc);
6697 	ASSERT(flag == SDR_RANGE || badseg1->s_size == pgsz ||
6698 	    badseg1->s_size == 2 * pgsz);
6699 	ASSERT(sameprot(badseg1, badseg1->s_base, pgsz));
6700 	ASSERT(badseg1->s_size == pgsz ||
6701 	    sameprot(badseg1, badseg1->s_base + pgsz, pgsz));
6702 	if (err = segvn_clrszc(badseg1)) {
6703 		return (err);
6704 	}
6705 	ASSERT(badseg1->s_szc == 0);
6706 
6707 	if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6708 		uint_t tszc = highbit(tszcvec) - 1;
6709 		caddr_t ta = MAX(addr, badseg1->s_base);
6710 		caddr_t te;
6711 		size_t tpgsz = page_get_pagesize(tszc);
6712 
6713 		ASSERT(svd->type == MAP_SHARED);
6714 		ASSERT(flag == SDR_END);
6715 		ASSERT(tszc < szc && tszc > 0);
6716 
6717 		if (eaddr > badseg1->s_base + badseg1->s_size) {
6718 			te = badseg1->s_base + badseg1->s_size;
6719 		} else {
6720 			te = eaddr;
6721 		}
6722 
6723 		ASSERT(ta <= te);
6724 		badseg1->s_szc = tszc;
6725 		if (!IS_P2ALIGNED(ta, tpgsz) || !IS_P2ALIGNED(te, tpgsz)) {
6726 			if (badseg2 != NULL) {
6727 				err = segvn_demote_range(badseg1, ta, te - ta,
6728 				    SDR_END, tszcvec);
6729 				if (err != 0) {
6730 					return (err);
6731 				}
6732 			} else {
6733 				return (segvn_demote_range(badseg1, ta,
6734 				    te - ta, SDR_END, tszcvec));
6735 			}
6736 		}
6737 	}
6738 
6739 	if (badseg2 == NULL)
6740 		return (0);
6741 	ASSERT(badseg2->s_szc == szc);
6742 	ASSERT(badseg2->s_size == pgsz);
6743 	ASSERT(sameprot(badseg2, badseg2->s_base, badseg2->s_size));
6744 	if (err = segvn_clrszc(badseg2)) {
6745 		return (err);
6746 	}
6747 	ASSERT(badseg2->s_szc == 0);
6748 
6749 	if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6750 		uint_t tszc = highbit(tszcvec) - 1;
6751 		size_t tpgsz = page_get_pagesize(tszc);
6752 
6753 		ASSERT(svd->type == MAP_SHARED);
6754 		ASSERT(flag == SDR_END);
6755 		ASSERT(tszc < szc && tszc > 0);
6756 		ASSERT(badseg2->s_base > addr);
6757 		ASSERT(eaddr > badseg2->s_base);
6758 		ASSERT(eaddr < badseg2->s_base + badseg2->s_size);
6759 
6760 		badseg2->s_szc = tszc;
6761 		if (!IS_P2ALIGNED(eaddr, tpgsz)) {
6762 			return (segvn_demote_range(badseg2, badseg2->s_base,
6763 			    eaddr - badseg2->s_base, SDR_END, tszcvec));
6764 		}
6765 	}
6766 
6767 	return (0);
6768 }
6769 
6770 static int
6771 segvn_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
6772 {
6773 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6774 	struct vpage *vp, *evp;
6775 
6776 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6777 
6778 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6779 	/*
6780 	 * If segment protection can be used, simply check against them.
6781 	 */
6782 	if (svd->pageprot == 0) {
6783 		int err;
6784 
6785 		err = ((svd->prot & prot) != prot) ? EACCES : 0;
6786 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6787 		return (err);
6788 	}
6789 
6790 	/*
6791 	 * Have to check down to the vpage level.
6792 	 */
6793 	evp = &svd->vpage[seg_page(seg, addr + len)];
6794 	for (vp = &svd->vpage[seg_page(seg, addr)]; vp < evp; vp++) {
6795 		if ((VPP_PROT(vp) & prot) != prot) {
6796 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6797 			return (EACCES);
6798 		}
6799 	}
6800 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6801 	return (0);
6802 }
6803 
6804 static int
6805 segvn_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
6806 {
6807 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6808 	size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
6809 
6810 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6811 
6812 	if (pgno != 0) {
6813 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6814 		if (svd->pageprot == 0) {
6815 			do {
6816 				protv[--pgno] = svd->prot;
6817 			} while (pgno != 0);
6818 		} else {
6819 			size_t pgoff = seg_page(seg, addr);
6820 
6821 			do {
6822 				pgno--;
6823 				protv[pgno] = VPP_PROT(&svd->vpage[pgno+pgoff]);
6824 			} while (pgno != 0);
6825 		}
6826 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6827 	}
6828 	return (0);
6829 }
6830 
6831 static u_offset_t
6832 segvn_getoffset(struct seg *seg, caddr_t addr)
6833 {
6834 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6835 
6836 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6837 
6838 	return (svd->offset + (uintptr_t)(addr - seg->s_base));
6839 }
6840 
6841 /*ARGSUSED*/
6842 static int
6843 segvn_gettype(struct seg *seg, caddr_t addr)
6844 {
6845 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6846 
6847 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6848 
6849 	return (svd->type | (svd->flags & (MAP_NORESERVE | MAP_TEXT |
6850 	    MAP_INITDATA)));
6851 }
6852 
6853 /*ARGSUSED*/
6854 static int
6855 segvn_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
6856 {
6857 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6858 
6859 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6860 
6861 	*vpp = svd->vp;
6862 	return (0);
6863 }
6864 
6865 /*
6866  * Check to see if it makes sense to do kluster/read ahead to
6867  * addr + delta relative to the mapping at addr.  We assume here
6868  * that delta is a signed PAGESIZE'd multiple (which can be negative).
6869  *
6870  * For segvn, we currently "approve" of the action if we are
6871  * still in the segment and it maps from the same vp/off,
6872  * or if the advice stored in segvn_data or vpages allows it.
6873  * Currently, klustering is not allowed only if MADV_RANDOM is set.
6874  */
6875 static int
6876 segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta)
6877 {
6878 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6879 	struct anon *oap, *ap;
6880 	ssize_t pd;
6881 	size_t page;
6882 	struct vnode *vp1, *vp2;
6883 	u_offset_t off1, off2;
6884 	struct anon_map *amp;
6885 
6886 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6887 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6888 	    SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
6889 
6890 	if (addr + delta < seg->s_base ||
6891 	    addr + delta >= (seg->s_base + seg->s_size))
6892 		return (-1);		/* exceeded segment bounds */
6893 
6894 	pd = delta / (ssize_t)PAGESIZE;	/* divide to preserve sign bit */
6895 	page = seg_page(seg, addr);
6896 
6897 	/*
6898 	 * Check to see if either of the pages addr or addr + delta
6899 	 * have advice set that prevents klustering (if MADV_RANDOM advice
6900 	 * is set for entire segment, or MADV_SEQUENTIAL is set and delta
6901 	 * is negative).
6902 	 */
6903 	if (svd->advice == MADV_RANDOM ||
6904 	    svd->advice == MADV_SEQUENTIAL && delta < 0)
6905 		return (-1);
6906 	else if (svd->pageadvice && svd->vpage) {
6907 		struct vpage *bvpp, *evpp;
6908 
6909 		bvpp = &svd->vpage[page];
6910 		evpp = &svd->vpage[page + pd];
6911 		if (VPP_ADVICE(bvpp) == MADV_RANDOM ||
6912 		    VPP_ADVICE(evpp) == MADV_SEQUENTIAL && delta < 0)
6913 			return (-1);
6914 		if (VPP_ADVICE(bvpp) != VPP_ADVICE(evpp) &&
6915 		    VPP_ADVICE(evpp) == MADV_RANDOM)
6916 			return (-1);
6917 	}
6918 
6919 	if (svd->type == MAP_SHARED)
6920 		return (0);		/* shared mapping - all ok */
6921 
6922 	if ((amp = svd->amp) == NULL)
6923 		return (0);		/* off original vnode */
6924 
6925 	page += svd->anon_index;
6926 
6927 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
6928 
6929 	oap = anon_get_ptr(amp->ahp, page);
6930 	ap = anon_get_ptr(amp->ahp, page + pd);
6931 
6932 	ANON_LOCK_EXIT(&amp->a_rwlock);
6933 
6934 	if ((oap == NULL && ap != NULL) || (oap != NULL && ap == NULL)) {
6935 		return (-1);		/* one with and one without an anon */
6936 	}
6937 
6938 	if (oap == NULL) {		/* implies that ap == NULL */
6939 		return (0);		/* off original vnode */
6940 	}
6941 
6942 	/*
6943 	 * Now we know we have two anon pointers - check to
6944 	 * see if they happen to be properly allocated.
6945 	 */
6946 
6947 	/*
6948 	 * XXX We cheat here and don't lock the anon slots. We can't because
6949 	 * we may have been called from the anon layer which might already
6950 	 * have locked them. We are holding a refcnt on the slots so they
6951 	 * can't disappear. The worst that will happen is we'll get the wrong
6952 	 * names (vp, off) for the slots and make a poor klustering decision.
6953 	 */
6954 	swap_xlate(ap, &vp1, &off1);
6955 	swap_xlate(oap, &vp2, &off2);
6956 
6957 
6958 	if (!VOP_CMP(vp1, vp2, NULL) || off1 - off2 != delta)
6959 		return (-1);
6960 	return (0);
6961 }
6962 
6963 /*
6964  * Swap the pages of seg out to secondary storage, returning the
6965  * number of bytes of storage freed.
6966  *
6967  * The basic idea is first to unload all translations and then to call
6968  * VOP_PUTPAGE() for all newly-unmapped pages, to push them out to the
6969  * swap device.  Pages to which other segments have mappings will remain
6970  * mapped and won't be swapped.  Our caller (as_swapout) has already
6971  * performed the unloading step.
6972  *
6973  * The value returned is intended to correlate well with the process's
6974  * memory requirements.  However, there are some caveats:
6975  * 1)	When given a shared segment as argument, this routine will
6976  *	only succeed in swapping out pages for the last sharer of the
6977  *	segment.  (Previous callers will only have decremented mapping
6978  *	reference counts.)
6979  * 2)	We assume that the hat layer maintains a large enough translation
6980  *	cache to capture process reference patterns.
6981  */
6982 static size_t
6983 segvn_swapout(struct seg *seg)
6984 {
6985 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6986 	struct anon_map *amp;
6987 	pgcnt_t pgcnt = 0;
6988 	pgcnt_t npages;
6989 	pgcnt_t page;
6990 	ulong_t anon_index;
6991 
6992 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6993 
6994 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6995 	/*
6996 	 * Find pages unmapped by our caller and force them
6997 	 * out to the virtual swap device.
6998 	 */
6999 	if ((amp = svd->amp) != NULL)
7000 		anon_index = svd->anon_index;
7001 	npages = seg->s_size >> PAGESHIFT;
7002 	for (page = 0; page < npages; page++) {
7003 		page_t *pp;
7004 		struct anon *ap;
7005 		struct vnode *vp;
7006 		u_offset_t off;
7007 		anon_sync_obj_t cookie;
7008 
7009 		/*
7010 		 * Obtain <vp, off> pair for the page, then look it up.
7011 		 *
7012 		 * Note that this code is willing to consider regular
7013 		 * pages as well as anon pages.  Is this appropriate here?
7014 		 */
7015 		ap = NULL;
7016 		if (amp != NULL) {
7017 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7018 			if (anon_array_try_enter(amp, anon_index + page,
7019 			    &cookie)) {
7020 				ANON_LOCK_EXIT(&amp->a_rwlock);
7021 				continue;
7022 			}
7023 			ap = anon_get_ptr(amp->ahp, anon_index + page);
7024 			if (ap != NULL) {
7025 				swap_xlate(ap, &vp, &off);
7026 			} else {
7027 				vp = svd->vp;
7028 				off = svd->offset + ptob(page);
7029 			}
7030 			anon_array_exit(&cookie);
7031 			ANON_LOCK_EXIT(&amp->a_rwlock);
7032 		} else {
7033 			vp = svd->vp;
7034 			off = svd->offset + ptob(page);
7035 		}
7036 		if (vp == NULL) {		/* untouched zfod page */
7037 			ASSERT(ap == NULL);
7038 			continue;
7039 		}
7040 
7041 		pp = page_lookup_nowait(vp, off, SE_SHARED);
7042 		if (pp == NULL)
7043 			continue;
7044 
7045 
7046 		/*
7047 		 * Examine the page to see whether it can be tossed out,
7048 		 * keeping track of how many we've found.
7049 		 */
7050 		if (!page_tryupgrade(pp)) {
7051 			/*
7052 			 * If the page has an i/o lock and no mappings,
7053 			 * it's very likely that the page is being
7054 			 * written out as a result of klustering.
7055 			 * Assume this is so and take credit for it here.
7056 			 */
7057 			if (!page_io_trylock(pp)) {
7058 				if (!hat_page_is_mapped(pp))
7059 					pgcnt++;
7060 			} else {
7061 				page_io_unlock(pp);
7062 			}
7063 			page_unlock(pp);
7064 			continue;
7065 		}
7066 		ASSERT(!page_iolock_assert(pp));
7067 
7068 
7069 		/*
7070 		 * Skip if page is locked or has mappings.
7071 		 * We don't need the page_struct_lock to look at lckcnt
7072 		 * and cowcnt because the page is exclusive locked.
7073 		 */
7074 		if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0 ||
7075 		    hat_page_is_mapped(pp)) {
7076 			page_unlock(pp);
7077 			continue;
7078 		}
7079 
7080 		/*
7081 		 * dispose skips large pages so try to demote first.
7082 		 */
7083 		if (pp->p_szc != 0 && !page_try_demote_pages(pp)) {
7084 			page_unlock(pp);
7085 			/*
7086 			 * XXX should skip the remaining page_t's of this
7087 			 * large page.
7088 			 */
7089 			continue;
7090 		}
7091 
7092 		ASSERT(pp->p_szc == 0);
7093 
7094 		/*
7095 		 * No longer mapped -- we can toss it out.  How
7096 		 * we do so depends on whether or not it's dirty.
7097 		 */
7098 		if (hat_ismod(pp) && pp->p_vnode) {
7099 			/*
7100 			 * We must clean the page before it can be
7101 			 * freed.  Setting B_FREE will cause pvn_done
7102 			 * to free the page when the i/o completes.
7103 			 * XXX:	This also causes it to be accounted
7104 			 *	as a pageout instead of a swap: need
7105 			 *	B_SWAPOUT bit to use instead of B_FREE.
7106 			 *
7107 			 * Hold the vnode before releasing the page lock
7108 			 * to prevent it from being freed and re-used by
7109 			 * some other thread.
7110 			 */
7111 			VN_HOLD(vp);
7112 			page_unlock(pp);
7113 
7114 			/*
7115 			 * Queue all i/o requests for the pageout thread
7116 			 * to avoid saturating the pageout devices.
7117 			 */
7118 			if (!queue_io_request(vp, off))
7119 				VN_RELE(vp);
7120 		} else {
7121 			/*
7122 			 * The page was clean, free it.
7123 			 *
7124 			 * XXX:	Can we ever encounter modified pages
7125 			 *	with no associated vnode here?
7126 			 */
7127 			ASSERT(pp->p_vnode != NULL);
7128 			/*LINTED: constant in conditional context*/
7129 			VN_DISPOSE(pp, B_FREE, 0, kcred);
7130 		}
7131 
7132 		/*
7133 		 * Credit now even if i/o is in progress.
7134 		 */
7135 		pgcnt++;
7136 	}
7137 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7138 
7139 	/*
7140 	 * Wakeup pageout to initiate i/o on all queued requests.
7141 	 */
7142 	cv_signal_pageout();
7143 	return (ptob(pgcnt));
7144 }
7145 
7146 /*
7147  * Synchronize primary storage cache with real object in virtual memory.
7148  *
7149  * XXX - Anonymous pages should not be sync'ed out at all.
7150  */
7151 static int
7152 segvn_sync(struct seg *seg, caddr_t addr, size_t len, int attr, uint_t flags)
7153 {
7154 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7155 	struct vpage *vpp;
7156 	page_t *pp;
7157 	u_offset_t offset;
7158 	struct vnode *vp;
7159 	u_offset_t off;
7160 	caddr_t eaddr;
7161 	int bflags;
7162 	int err = 0;
7163 	int segtype;
7164 	int pageprot;
7165 	int prot;
7166 	ulong_t anon_index;
7167 	struct anon_map *amp;
7168 	struct anon *ap;
7169 	anon_sync_obj_t cookie;
7170 
7171 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7172 
7173 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7174 
7175 	if (svd->softlockcnt > 0) {
7176 		/*
7177 		 * If this is shared segment non 0 softlockcnt
7178 		 * means locked pages are still in use.
7179 		 */
7180 		if (svd->type == MAP_SHARED) {
7181 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7182 			return (EAGAIN);
7183 		}
7184 
7185 		/*
7186 		 * flush all pages from seg cache
7187 		 * otherwise we may deadlock in swap_putpage
7188 		 * for B_INVAL page (4175402).
7189 		 *
7190 		 * Even if we grab segvn WRITER's lock
7191 		 * here, there might be another thread which could've
7192 		 * successfully performed lookup/insert just before
7193 		 * we acquired the lock here.  So, grabbing either
7194 		 * lock here is of not much use.  Until we devise
7195 		 * a strategy at upper layers to solve the
7196 		 * synchronization issues completely, we expect
7197 		 * applications to handle this appropriately.
7198 		 */
7199 		segvn_purge(seg);
7200 		if (svd->softlockcnt > 0) {
7201 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7202 			return (EAGAIN);
7203 		}
7204 	} else if (svd->type == MAP_SHARED && svd->amp != NULL &&
7205 	    svd->amp->a_softlockcnt > 0) {
7206 		/*
7207 		 * Try to purge this amp's entries from pcache. It will
7208 		 * succeed only if other segments that share the amp have no
7209 		 * outstanding softlock's.
7210 		 */
7211 		segvn_purge(seg);
7212 		if (svd->amp->a_softlockcnt > 0 || svd->softlockcnt > 0) {
7213 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7214 			return (EAGAIN);
7215 		}
7216 	}
7217 
7218 	vpp = svd->vpage;
7219 	offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7220 	bflags = ((flags & MS_ASYNC) ? B_ASYNC : 0) |
7221 	    ((flags & MS_INVALIDATE) ? B_INVAL : 0);
7222 
7223 	if (attr) {
7224 		pageprot = attr & ~(SHARED|PRIVATE);
7225 		segtype = (attr & SHARED) ? MAP_SHARED : MAP_PRIVATE;
7226 
7227 		/*
7228 		 * We are done if the segment types don't match
7229 		 * or if we have segment level protections and
7230 		 * they don't match.
7231 		 */
7232 		if (svd->type != segtype) {
7233 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7234 			return (0);
7235 		}
7236 		if (vpp == NULL) {
7237 			if (svd->prot != pageprot) {
7238 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7239 				return (0);
7240 			}
7241 			prot = svd->prot;
7242 		} else
7243 			vpp = &svd->vpage[seg_page(seg, addr)];
7244 
7245 	} else if (svd->vp && svd->amp == NULL &&
7246 	    (flags & MS_INVALIDATE) == 0) {
7247 
7248 		/*
7249 		 * No attributes, no anonymous pages and MS_INVALIDATE flag
7250 		 * is not on, just use one big request.
7251 		 */
7252 		err = VOP_PUTPAGE(svd->vp, (offset_t)offset, len,
7253 		    bflags, svd->cred, NULL);
7254 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7255 		return (err);
7256 	}
7257 
7258 	if ((amp = svd->amp) != NULL)
7259 		anon_index = svd->anon_index + seg_page(seg, addr);
7260 
7261 	for (eaddr = addr + len; addr < eaddr; addr += PAGESIZE) {
7262 		ap = NULL;
7263 		if (amp != NULL) {
7264 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7265 			anon_array_enter(amp, anon_index, &cookie);
7266 			ap = anon_get_ptr(amp->ahp, anon_index++);
7267 			if (ap != NULL) {
7268 				swap_xlate(ap, &vp, &off);
7269 			} else {
7270 				vp = svd->vp;
7271 				off = offset;
7272 			}
7273 			anon_array_exit(&cookie);
7274 			ANON_LOCK_EXIT(&amp->a_rwlock);
7275 		} else {
7276 			vp = svd->vp;
7277 			off = offset;
7278 		}
7279 		offset += PAGESIZE;
7280 
7281 		if (vp == NULL)		/* untouched zfod page */
7282 			continue;
7283 
7284 		if (attr) {
7285 			if (vpp) {
7286 				prot = VPP_PROT(vpp);
7287 				vpp++;
7288 			}
7289 			if (prot != pageprot) {
7290 				continue;
7291 			}
7292 		}
7293 
7294 		/*
7295 		 * See if any of these pages are locked --  if so, then we
7296 		 * will have to truncate an invalidate request at the first
7297 		 * locked one. We don't need the page_struct_lock to test
7298 		 * as this is only advisory; even if we acquire it someone
7299 		 * might race in and lock the page after we unlock and before
7300 		 * we do the PUTPAGE, then PUTPAGE simply does nothing.
7301 		 */
7302 		if (flags & MS_INVALIDATE) {
7303 			if ((pp = page_lookup(vp, off, SE_SHARED)) != NULL) {
7304 				if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0) {
7305 					page_unlock(pp);
7306 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7307 					return (EBUSY);
7308 				}
7309 				if (ap != NULL && pp->p_szc != 0 &&
7310 				    page_tryupgrade(pp)) {
7311 					if (pp->p_lckcnt == 0 &&
7312 					    pp->p_cowcnt == 0) {
7313 						/*
7314 						 * swapfs VN_DISPOSE() won't
7315 						 * invalidate large pages.
7316 						 * Attempt to demote.
7317 						 * XXX can't help it if it
7318 						 * fails. But for swapfs
7319 						 * pages it is no big deal.
7320 						 */
7321 						(void) page_try_demote_pages(
7322 						    pp);
7323 					}
7324 				}
7325 				page_unlock(pp);
7326 			}
7327 		} else if (svd->type == MAP_SHARED && amp != NULL) {
7328 			/*
7329 			 * Avoid writing out to disk ISM's large pages
7330 			 * because segspt_free_pages() relies on NULL an_pvp
7331 			 * of anon slots of such pages.
7332 			 */
7333 
7334 			ASSERT(svd->vp == NULL);
7335 			/*
7336 			 * swapfs uses page_lookup_nowait if not freeing or
7337 			 * invalidating and skips a page if
7338 			 * page_lookup_nowait returns NULL.
7339 			 */
7340 			pp = page_lookup_nowait(vp, off, SE_SHARED);
7341 			if (pp == NULL) {
7342 				continue;
7343 			}
7344 			if (pp->p_szc != 0) {
7345 				page_unlock(pp);
7346 				continue;
7347 			}
7348 
7349 			/*
7350 			 * Note ISM pages are created large so (vp, off)'s
7351 			 * page cannot suddenly become large after we unlock
7352 			 * pp.
7353 			 */
7354 			page_unlock(pp);
7355 		}
7356 		/*
7357 		 * XXX - Should ultimately try to kluster
7358 		 * calls to VOP_PUTPAGE() for performance.
7359 		 */
7360 		VN_HOLD(vp);
7361 		err = VOP_PUTPAGE(vp, (offset_t)off, PAGESIZE,
7362 		    (bflags | (IS_SWAPFSVP(vp) ? B_PAGE_NOWAIT : 0)),
7363 		    svd->cred, NULL);
7364 
7365 		VN_RELE(vp);
7366 		if (err)
7367 			break;
7368 	}
7369 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7370 	return (err);
7371 }
7372 
7373 /*
7374  * Determine if we have data corresponding to pages in the
7375  * primary storage virtual memory cache (i.e., "in core").
7376  */
7377 static size_t
7378 segvn_incore(struct seg *seg, caddr_t addr, size_t len, char *vec)
7379 {
7380 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7381 	struct vnode *vp, *avp;
7382 	u_offset_t offset, aoffset;
7383 	size_t p, ep;
7384 	int ret;
7385 	struct vpage *vpp;
7386 	page_t *pp;
7387 	uint_t start;
7388 	struct anon_map *amp;		/* XXX - for locknest */
7389 	struct anon *ap;
7390 	uint_t attr;
7391 	anon_sync_obj_t cookie;
7392 
7393 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7394 
7395 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7396 	if (svd->amp == NULL && svd->vp == NULL) {
7397 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7398 		bzero(vec, btopr(len));
7399 		return (len);	/* no anonymous pages created yet */
7400 	}
7401 
7402 	p = seg_page(seg, addr);
7403 	ep = seg_page(seg, addr + len);
7404 	start = svd->vp ? SEG_PAGE_VNODEBACKED : 0;
7405 
7406 	amp = svd->amp;
7407 	for (; p < ep; p++, addr += PAGESIZE) {
7408 		vpp = (svd->vpage) ? &svd->vpage[p]: NULL;
7409 		ret = start;
7410 		ap = NULL;
7411 		avp = NULL;
7412 		/* Grab the vnode/offset for the anon slot */
7413 		if (amp != NULL) {
7414 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7415 			anon_array_enter(amp, svd->anon_index + p, &cookie);
7416 			ap = anon_get_ptr(amp->ahp, svd->anon_index + p);
7417 			if (ap != NULL) {
7418 				swap_xlate(ap, &avp, &aoffset);
7419 			}
7420 			anon_array_exit(&cookie);
7421 			ANON_LOCK_EXIT(&amp->a_rwlock);
7422 		}
7423 		if ((avp != NULL) && page_exists(avp, aoffset)) {
7424 			/* A page exists for the anon slot */
7425 			ret |= SEG_PAGE_INCORE;
7426 
7427 			/*
7428 			 * If page is mapped and writable
7429 			 */
7430 			attr = (uint_t)0;
7431 			if ((hat_getattr(seg->s_as->a_hat, addr,
7432 			    &attr) != -1) && (attr & PROT_WRITE)) {
7433 				ret |= SEG_PAGE_ANON;
7434 			}
7435 			/*
7436 			 * Don't get page_struct lock for lckcnt and cowcnt,
7437 			 * since this is purely advisory.
7438 			 */
7439 			if ((pp = page_lookup_nowait(avp, aoffset,
7440 			    SE_SHARED)) != NULL) {
7441 				if (pp->p_lckcnt)
7442 					ret |= SEG_PAGE_SOFTLOCK;
7443 				if (pp->p_cowcnt)
7444 					ret |= SEG_PAGE_HASCOW;
7445 				page_unlock(pp);
7446 			}
7447 		}
7448 
7449 		/* Gather vnode statistics */
7450 		vp = svd->vp;
7451 		offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7452 
7453 		if (vp != NULL) {
7454 			/*
7455 			 * Try to obtain a "shared" lock on the page
7456 			 * without blocking.  If this fails, determine
7457 			 * if the page is in memory.
7458 			 */
7459 			pp = page_lookup_nowait(vp, offset, SE_SHARED);
7460 			if ((pp == NULL) && (page_exists(vp, offset))) {
7461 				/* Page is incore, and is named */
7462 				ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7463 			}
7464 			/*
7465 			 * Don't get page_struct lock for lckcnt and cowcnt,
7466 			 * since this is purely advisory.
7467 			 */
7468 			if (pp != NULL) {
7469 				ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7470 				if (pp->p_lckcnt)
7471 					ret |= SEG_PAGE_SOFTLOCK;
7472 				if (pp->p_cowcnt)
7473 					ret |= SEG_PAGE_HASCOW;
7474 				page_unlock(pp);
7475 			}
7476 		}
7477 
7478 		/* Gather virtual page information */
7479 		if (vpp) {
7480 			if (VPP_ISPPLOCK(vpp))
7481 				ret |= SEG_PAGE_LOCKED;
7482 			vpp++;
7483 		}
7484 
7485 		*vec++ = (char)ret;
7486 	}
7487 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7488 	return (len);
7489 }
7490 
7491 /*
7492  * Statement for p_cowcnts/p_lckcnts.
7493  *
7494  * p_cowcnt is updated while mlock/munlocking MAP_PRIVATE and PROT_WRITE region
7495  * irrespective of the following factors or anything else:
7496  *
7497  *	(1) anon slots are populated or not
7498  *	(2) cow is broken or not
7499  *	(3) refcnt on ap is 1 or greater than 1
7500  *
7501  * If it's not MAP_PRIVATE and PROT_WRITE, p_lckcnt is updated during mlock
7502  * and munlock.
7503  *
7504  *
7505  * Handling p_cowcnts/p_lckcnts during copy-on-write fault:
7506  *
7507  *	if vpage has PROT_WRITE
7508  *		transfer cowcnt on the oldpage -> cowcnt on the newpage
7509  *	else
7510  *		transfer lckcnt on the oldpage -> lckcnt on the newpage
7511  *
7512  *	During copy-on-write, decrement p_cowcnt on the oldpage and increment
7513  *	p_cowcnt on the newpage *if* the corresponding vpage has PROT_WRITE.
7514  *
7515  *	We may also break COW if softlocking on read access in the physio case.
7516  *	In this case, vpage may not have PROT_WRITE. So, we need to decrement
7517  *	p_lckcnt on the oldpage and increment p_lckcnt on the newpage *if* the
7518  *	vpage doesn't have PROT_WRITE.
7519  *
7520  *
7521  * Handling p_cowcnts/p_lckcnts during mprotect on mlocked region:
7522  *
7523  * 	If a MAP_PRIVATE region loses PROT_WRITE, we decrement p_cowcnt and
7524  *	increment p_lckcnt by calling page_subclaim() which takes care of
7525  * 	availrmem accounting and p_lckcnt overflow.
7526  *
7527  *	If a MAP_PRIVATE region gains PROT_WRITE, we decrement p_lckcnt and
7528  *	increment p_cowcnt by calling page_addclaim() which takes care of
7529  *	availrmem availability and p_cowcnt overflow.
7530  */
7531 
7532 /*
7533  * Lock down (or unlock) pages mapped by this segment.
7534  *
7535  * XXX only creates PAGESIZE pages if anon slots are not initialized.
7536  * At fault time they will be relocated into larger pages.
7537  */
7538 static int
7539 segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
7540     int attr, int op, ulong_t *lockmap, size_t pos)
7541 {
7542 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7543 	struct vpage *vpp;
7544 	struct vpage *evp;
7545 	page_t *pp;
7546 	u_offset_t offset;
7547 	u_offset_t off;
7548 	int segtype;
7549 	int pageprot;
7550 	int claim;
7551 	struct vnode *vp;
7552 	ulong_t anon_index;
7553 	struct anon_map *amp;
7554 	struct anon *ap;
7555 	struct vattr va;
7556 	anon_sync_obj_t cookie;
7557 	struct kshmid *sp = NULL;
7558 	struct proc	*p = curproc;
7559 	kproject_t	*proj = NULL;
7560 	int chargeproc = 1;
7561 	size_t locked_bytes = 0;
7562 	size_t unlocked_bytes = 0;
7563 	int err = 0;
7564 
7565 	/*
7566 	 * Hold write lock on address space because may split or concatenate
7567 	 * segments
7568 	 */
7569 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7570 
7571 	/*
7572 	 * If this is a shm, use shm's project and zone, else use
7573 	 * project and zone of calling process
7574 	 */
7575 
7576 	/* Determine if this segment backs a sysV shm */
7577 	if (svd->amp != NULL && svd->amp->a_sp != NULL) {
7578 		ASSERT(svd->type == MAP_SHARED);
7579 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
7580 		sp = svd->amp->a_sp;
7581 		proj = sp->shm_perm.ipc_proj;
7582 		chargeproc = 0;
7583 	}
7584 
7585 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
7586 	if (attr) {
7587 		pageprot = attr & ~(SHARED|PRIVATE);
7588 		segtype = attr & SHARED ? MAP_SHARED : MAP_PRIVATE;
7589 
7590 		/*
7591 		 * We are done if the segment types don't match
7592 		 * or if we have segment level protections and
7593 		 * they don't match.
7594 		 */
7595 		if (svd->type != segtype) {
7596 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7597 			return (0);
7598 		}
7599 		if (svd->pageprot == 0 && svd->prot != pageprot) {
7600 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7601 			return (0);
7602 		}
7603 	}
7604 
7605 	if (op == MC_LOCK) {
7606 		if (svd->tr_state == SEGVN_TR_INIT) {
7607 			svd->tr_state = SEGVN_TR_OFF;
7608 		} else if (svd->tr_state == SEGVN_TR_ON) {
7609 			ASSERT(svd->amp != NULL);
7610 			segvn_textunrepl(seg, 0);
7611 			ASSERT(svd->amp == NULL &&
7612 			    svd->tr_state == SEGVN_TR_OFF);
7613 		}
7614 	}
7615 
7616 	/*
7617 	 * If we're locking, then we must create a vpage structure if
7618 	 * none exists.  If we're unlocking, then check to see if there
7619 	 * is a vpage --  if not, then we could not have locked anything.
7620 	 */
7621 
7622 	if ((vpp = svd->vpage) == NULL) {
7623 		if (op == MC_LOCK)
7624 			segvn_vpage(seg);
7625 		else {
7626 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7627 			return (0);
7628 		}
7629 	}
7630 
7631 	/*
7632 	 * The anonymous data vector (i.e., previously
7633 	 * unreferenced mapping to swap space) can be allocated
7634 	 * by lazily testing for its existence.
7635 	 */
7636 	if (op == MC_LOCK && svd->amp == NULL && svd->vp == NULL) {
7637 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
7638 		svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
7639 		svd->amp->a_szc = seg->s_szc;
7640 	}
7641 
7642 	if ((amp = svd->amp) != NULL) {
7643 		anon_index = svd->anon_index + seg_page(seg, addr);
7644 	}
7645 
7646 	offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7647 	evp = &svd->vpage[seg_page(seg, addr + len)];
7648 
7649 	if (sp != NULL)
7650 		mutex_enter(&sp->shm_mlock);
7651 
7652 	/* determine number of unlocked bytes in range for lock operation */
7653 	if (op == MC_LOCK) {
7654 
7655 		if (sp == NULL) {
7656 			for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7657 			    vpp++) {
7658 				if (!VPP_ISPPLOCK(vpp))
7659 					unlocked_bytes += PAGESIZE;
7660 			}
7661 		} else {
7662 			ulong_t		i_idx, i_edx;
7663 			anon_sync_obj_t	i_cookie;
7664 			struct anon	*i_ap;
7665 			struct vnode	*i_vp;
7666 			u_offset_t	i_off;
7667 
7668 			/* Only count sysV pages once for locked memory */
7669 			i_edx = svd->anon_index + seg_page(seg, addr + len);
7670 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7671 			for (i_idx = anon_index; i_idx < i_edx; i_idx++) {
7672 				anon_array_enter(amp, i_idx, &i_cookie);
7673 				i_ap = anon_get_ptr(amp->ahp, i_idx);
7674 				if (i_ap == NULL) {
7675 					unlocked_bytes += PAGESIZE;
7676 					anon_array_exit(&i_cookie);
7677 					continue;
7678 				}
7679 				swap_xlate(i_ap, &i_vp, &i_off);
7680 				anon_array_exit(&i_cookie);
7681 				pp = page_lookup(i_vp, i_off, SE_SHARED);
7682 				if (pp == NULL) {
7683 					unlocked_bytes += PAGESIZE;
7684 					continue;
7685 				} else if (pp->p_lckcnt == 0)
7686 					unlocked_bytes += PAGESIZE;
7687 				page_unlock(pp);
7688 			}
7689 			ANON_LOCK_EXIT(&amp->a_rwlock);
7690 		}
7691 
7692 		mutex_enter(&p->p_lock);
7693 		err = rctl_incr_locked_mem(p, proj, unlocked_bytes,
7694 		    chargeproc);
7695 		mutex_exit(&p->p_lock);
7696 
7697 		if (err) {
7698 			if (sp != NULL)
7699 				mutex_exit(&sp->shm_mlock);
7700 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7701 			return (err);
7702 		}
7703 	}
7704 	/*
7705 	 * Loop over all pages in the range.  Process if we're locking and
7706 	 * page has not already been locked in this mapping; or if we're
7707 	 * unlocking and the page has been locked.
7708 	 */
7709 	for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7710 	    vpp++, pos++, addr += PAGESIZE, offset += PAGESIZE, anon_index++) {
7711 		if ((attr == 0 || VPP_PROT(vpp) == pageprot) &&
7712 		    ((op == MC_LOCK && !VPP_ISPPLOCK(vpp)) ||
7713 		    (op == MC_UNLOCK && VPP_ISPPLOCK(vpp)))) {
7714 
7715 			if (amp != NULL)
7716 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7717 			/*
7718 			 * If this isn't a MAP_NORESERVE segment and
7719 			 * we're locking, allocate anon slots if they
7720 			 * don't exist.  The page is brought in later on.
7721 			 */
7722 			if (op == MC_LOCK && svd->vp == NULL &&
7723 			    ((svd->flags & MAP_NORESERVE) == 0) &&
7724 			    amp != NULL &&
7725 			    ((ap = anon_get_ptr(amp->ahp, anon_index))
7726 			    == NULL)) {
7727 				anon_array_enter(amp, anon_index, &cookie);
7728 
7729 				if ((ap = anon_get_ptr(amp->ahp,
7730 				    anon_index)) == NULL) {
7731 					pp = anon_zero(seg, addr, &ap,
7732 					    svd->cred);
7733 					if (pp == NULL) {
7734 						anon_array_exit(&cookie);
7735 						ANON_LOCK_EXIT(&amp->a_rwlock);
7736 						err = ENOMEM;
7737 						goto out;
7738 					}
7739 					ASSERT(anon_get_ptr(amp->ahp,
7740 					    anon_index) == NULL);
7741 					(void) anon_set_ptr(amp->ahp,
7742 					    anon_index, ap, ANON_SLEEP);
7743 					page_unlock(pp);
7744 				}
7745 				anon_array_exit(&cookie);
7746 			}
7747 
7748 			/*
7749 			 * Get name for page, accounting for
7750 			 * existence of private copy.
7751 			 */
7752 			ap = NULL;
7753 			if (amp != NULL) {
7754 				anon_array_enter(amp, anon_index, &cookie);
7755 				ap = anon_get_ptr(amp->ahp, anon_index);
7756 				if (ap != NULL) {
7757 					swap_xlate(ap, &vp, &off);
7758 				} else {
7759 					if (svd->vp == NULL &&
7760 					    (svd->flags & MAP_NORESERVE)) {
7761 						anon_array_exit(&cookie);
7762 						ANON_LOCK_EXIT(&amp->a_rwlock);
7763 						continue;
7764 					}
7765 					vp = svd->vp;
7766 					off = offset;
7767 				}
7768 				if (op != MC_LOCK || ap == NULL) {
7769 					anon_array_exit(&cookie);
7770 					ANON_LOCK_EXIT(&amp->a_rwlock);
7771 				}
7772 			} else {
7773 				vp = svd->vp;
7774 				off = offset;
7775 			}
7776 
7777 			/*
7778 			 * Get page frame.  It's ok if the page is
7779 			 * not available when we're unlocking, as this
7780 			 * may simply mean that a page we locked got
7781 			 * truncated out of existence after we locked it.
7782 			 *
7783 			 * Invoke VOP_GETPAGE() to obtain the page struct
7784 			 * since we may need to read it from disk if its
7785 			 * been paged out.
7786 			 */
7787 			if (op != MC_LOCK)
7788 				pp = page_lookup(vp, off, SE_SHARED);
7789 			else {
7790 				page_t *pl[1 + 1];
7791 				int error;
7792 
7793 				ASSERT(vp != NULL);
7794 
7795 				error = VOP_GETPAGE(vp, (offset_t)off, PAGESIZE,
7796 				    (uint_t *)NULL, pl, PAGESIZE, seg, addr,
7797 				    S_OTHER, svd->cred, NULL);
7798 
7799 				if (error && ap != NULL) {
7800 					anon_array_exit(&cookie);
7801 					ANON_LOCK_EXIT(&amp->a_rwlock);
7802 				}
7803 
7804 				/*
7805 				 * If the error is EDEADLK then we must bounce
7806 				 * up and drop all vm subsystem locks and then
7807 				 * retry the operation later
7808 				 * This behavior is a temporary measure because
7809 				 * ufs/sds logging is badly designed and will
7810 				 * deadlock if we don't allow this bounce to
7811 				 * happen.  The real solution is to re-design
7812 				 * the logging code to work properly.  See bug
7813 				 * 4125102 for details of the problem.
7814 				 */
7815 				if (error == EDEADLK) {
7816 					err = error;
7817 					goto out;
7818 				}
7819 				/*
7820 				 * Quit if we fail to fault in the page.  Treat
7821 				 * the failure as an error, unless the addr
7822 				 * is mapped beyond the end of a file.
7823 				 */
7824 				if (error && svd->vp) {
7825 					va.va_mask = AT_SIZE;
7826 					if (VOP_GETATTR(svd->vp, &va, 0,
7827 					    svd->cred, NULL) != 0) {
7828 						err = EIO;
7829 						goto out;
7830 					}
7831 					if (btopr(va.va_size) >=
7832 					    btopr(off + 1)) {
7833 						err = EIO;
7834 						goto out;
7835 					}
7836 					goto out;
7837 
7838 				} else if (error) {
7839 					err = EIO;
7840 					goto out;
7841 				}
7842 				pp = pl[0];
7843 				ASSERT(pp != NULL);
7844 			}
7845 
7846 			/*
7847 			 * See Statement at the beginning of this routine.
7848 			 *
7849 			 * claim is always set if MAP_PRIVATE and PROT_WRITE
7850 			 * irrespective of following factors:
7851 			 *
7852 			 * (1) anon slots are populated or not
7853 			 * (2) cow is broken or not
7854 			 * (3) refcnt on ap is 1 or greater than 1
7855 			 *
7856 			 * See 4140683 for details
7857 			 */
7858 			claim = ((VPP_PROT(vpp) & PROT_WRITE) &&
7859 			    (svd->type == MAP_PRIVATE));
7860 
7861 			/*
7862 			 * Perform page-level operation appropriate to
7863 			 * operation.  If locking, undo the SOFTLOCK
7864 			 * performed to bring the page into memory
7865 			 * after setting the lock.  If unlocking,
7866 			 * and no page was found, account for the claim
7867 			 * separately.
7868 			 */
7869 			if (op == MC_LOCK) {
7870 				int ret = 1;	/* Assume success */
7871 
7872 				ASSERT(!VPP_ISPPLOCK(vpp));
7873 
7874 				ret = page_pp_lock(pp, claim, 0);
7875 				if (ap != NULL) {
7876 					if (ap->an_pvp != NULL) {
7877 						anon_swap_free(ap, pp);
7878 					}
7879 					anon_array_exit(&cookie);
7880 					ANON_LOCK_EXIT(&amp->a_rwlock);
7881 				}
7882 				if (ret == 0) {
7883 					/* locking page failed */
7884 					page_unlock(pp);
7885 					err = EAGAIN;
7886 					goto out;
7887 				}
7888 				VPP_SETPPLOCK(vpp);
7889 				if (sp != NULL) {
7890 					if (pp->p_lckcnt == 1)
7891 						locked_bytes += PAGESIZE;
7892 				} else
7893 					locked_bytes += PAGESIZE;
7894 
7895 				if (lockmap != (ulong_t *)NULL)
7896 					BT_SET(lockmap, pos);
7897 
7898 				page_unlock(pp);
7899 			} else {
7900 				ASSERT(VPP_ISPPLOCK(vpp));
7901 				if (pp != NULL) {
7902 					/* sysV pages should be locked */
7903 					ASSERT(sp == NULL || pp->p_lckcnt > 0);
7904 					page_pp_unlock(pp, claim, 0);
7905 					if (sp != NULL) {
7906 						if (pp->p_lckcnt == 0)
7907 							unlocked_bytes
7908 							    += PAGESIZE;
7909 					} else
7910 						unlocked_bytes += PAGESIZE;
7911 					page_unlock(pp);
7912 				} else {
7913 					ASSERT(sp == NULL);
7914 					unlocked_bytes += PAGESIZE;
7915 				}
7916 				VPP_CLRPPLOCK(vpp);
7917 			}
7918 		}
7919 	}
7920 out:
7921 	if (op == MC_LOCK) {
7922 		/* Credit back bytes that did not get locked */
7923 		if ((unlocked_bytes - locked_bytes) > 0) {
7924 			if (proj == NULL)
7925 				mutex_enter(&p->p_lock);
7926 			rctl_decr_locked_mem(p, proj,
7927 			    (unlocked_bytes - locked_bytes), chargeproc);
7928 			if (proj == NULL)
7929 				mutex_exit(&p->p_lock);
7930 		}
7931 
7932 	} else {
7933 		/* Account bytes that were unlocked */
7934 		if (unlocked_bytes > 0) {
7935 			if (proj == NULL)
7936 				mutex_enter(&p->p_lock);
7937 			rctl_decr_locked_mem(p, proj, unlocked_bytes,
7938 			    chargeproc);
7939 			if (proj == NULL)
7940 				mutex_exit(&p->p_lock);
7941 		}
7942 	}
7943 	if (sp != NULL)
7944 		mutex_exit(&sp->shm_mlock);
7945 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7946 
7947 	return (err);
7948 }
7949 
7950 /*
7951  * Set advice from user for specified pages
7952  * There are 5 types of advice:
7953  *	MADV_NORMAL	- Normal (default) behavior (whatever that is)
7954  *	MADV_RANDOM	- Random page references
7955  *				do not allow readahead or 'klustering'
7956  *	MADV_SEQUENTIAL	- Sequential page references
7957  *				Pages previous to the one currently being
7958  *				accessed (determined by fault) are 'not needed'
7959  *				and are freed immediately
7960  *	MADV_WILLNEED	- Pages are likely to be used (fault ahead in mctl)
7961  *	MADV_DONTNEED	- Pages are not needed (synced out in mctl)
7962  *	MADV_FREE	- Contents can be discarded
7963  *	MADV_ACCESS_DEFAULT- Default access
7964  *	MADV_ACCESS_LWP	- Next LWP will access heavily
7965  *	MADV_ACCESS_MANY- Many LWPs or processes will access heavily
7966  */
7967 static int
7968 segvn_advise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
7969 {
7970 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7971 	size_t page;
7972 	int err = 0;
7973 	int already_set;
7974 	struct anon_map *amp;
7975 	ulong_t anon_index;
7976 	struct seg *next;
7977 	lgrp_mem_policy_t policy;
7978 	struct seg *prev;
7979 	struct vnode *vp;
7980 
7981 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7982 
7983 	/*
7984 	 * In case of MADV_FREE, we won't be modifying any segment private
7985 	 * data structures; so, we only need to grab READER's lock
7986 	 */
7987 	if (behav != MADV_FREE) {
7988 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
7989 		if (svd->tr_state != SEGVN_TR_OFF) {
7990 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7991 			return (0);
7992 		}
7993 	} else {
7994 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7995 	}
7996 
7997 	/*
7998 	 * Large pages are assumed to be only turned on when accesses to the
7999 	 * segment's address range have spatial and temporal locality. That
8000 	 * justifies ignoring MADV_SEQUENTIAL for large page segments.
8001 	 * Also, ignore advice affecting lgroup memory allocation
8002 	 * if don't need to do lgroup optimizations on this system
8003 	 */
8004 
8005 	if ((behav == MADV_SEQUENTIAL &&
8006 	    (seg->s_szc != 0 || HAT_IS_REGION_COOKIE_VALID(svd->rcookie))) ||
8007 	    (!lgrp_optimizations() && (behav == MADV_ACCESS_DEFAULT ||
8008 	    behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY))) {
8009 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8010 		return (0);
8011 	}
8012 
8013 	if (behav == MADV_SEQUENTIAL || behav == MADV_ACCESS_DEFAULT ||
8014 	    behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY) {
8015 		/*
8016 		 * Since we are going to unload hat mappings
8017 		 * we first have to flush the cache. Otherwise
8018 		 * this might lead to system panic if another
8019 		 * thread is doing physio on the range whose
8020 		 * mappings are unloaded by madvise(3C).
8021 		 */
8022 		if (svd->softlockcnt > 0) {
8023 			/*
8024 			 * If this is shared segment non 0 softlockcnt
8025 			 * means locked pages are still in use.
8026 			 */
8027 			if (svd->type == MAP_SHARED) {
8028 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8029 				return (EAGAIN);
8030 			}
8031 			/*
8032 			 * Since we do have the segvn writers lock
8033 			 * nobody can fill the cache with entries
8034 			 * belonging to this seg during the purge.
8035 			 * The flush either succeeds or we still
8036 			 * have pending I/Os. In the later case,
8037 			 * madvise(3C) fails.
8038 			 */
8039 			segvn_purge(seg);
8040 			if (svd->softlockcnt > 0) {
8041 				/*
8042 				 * Since madvise(3C) is advisory and
8043 				 * it's not part of UNIX98, madvise(3C)
8044 				 * failure here doesn't cause any hardship.
8045 				 * Note that we don't block in "as" layer.
8046 				 */
8047 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8048 				return (EAGAIN);
8049 			}
8050 		} else if (svd->type == MAP_SHARED && svd->amp != NULL &&
8051 		    svd->amp->a_softlockcnt > 0) {
8052 			/*
8053 			 * Try to purge this amp's entries from pcache. It
8054 			 * will succeed only if other segments that share the
8055 			 * amp have no outstanding softlock's.
8056 			 */
8057 			segvn_purge(seg);
8058 		}
8059 	}
8060 
8061 	amp = svd->amp;
8062 	vp = svd->vp;
8063 	if (behav == MADV_FREE) {
8064 		/*
8065 		 * MADV_FREE is not supported for segments with
8066 		 * underlying object; if anonmap is NULL, anon slots
8067 		 * are not yet populated and there is nothing for
8068 		 * us to do. As MADV_FREE is advisory, we don't
8069 		 * return error in either case.
8070 		 */
8071 		if (vp != NULL || amp == NULL) {
8072 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8073 			return (0);
8074 		}
8075 
8076 		segvn_purge(seg);
8077 
8078 		page = seg_page(seg, addr);
8079 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8080 		anon_disclaim(amp, svd->anon_index + page, len);
8081 		ANON_LOCK_EXIT(&amp->a_rwlock);
8082 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8083 		return (0);
8084 	}
8085 
8086 	/*
8087 	 * If advice is to be applied to entire segment,
8088 	 * use advice field in seg_data structure
8089 	 * otherwise use appropriate vpage entry.
8090 	 */
8091 	if ((addr == seg->s_base) && (len == seg->s_size)) {
8092 		switch (behav) {
8093 		case MADV_ACCESS_LWP:
8094 		case MADV_ACCESS_MANY:
8095 		case MADV_ACCESS_DEFAULT:
8096 			/*
8097 			 * Set memory allocation policy for this segment
8098 			 */
8099 			policy = lgrp_madv_to_policy(behav, len, svd->type);
8100 			if (svd->type == MAP_SHARED)
8101 				already_set = lgrp_shm_policy_set(policy, amp,
8102 				    svd->anon_index, vp, svd->offset, len);
8103 			else {
8104 				/*
8105 				 * For private memory, need writers lock on
8106 				 * address space because the segment may be
8107 				 * split or concatenated when changing policy
8108 				 */
8109 				if (AS_READ_HELD(seg->s_as,
8110 				    &seg->s_as->a_lock)) {
8111 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8112 					return (IE_RETRY);
8113 				}
8114 
8115 				already_set = lgrp_privm_policy_set(policy,
8116 				    &svd->policy_info, len);
8117 			}
8118 
8119 			/*
8120 			 * If policy set already and it shouldn't be reapplied,
8121 			 * don't do anything.
8122 			 */
8123 			if (already_set &&
8124 			    !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8125 				break;
8126 
8127 			/*
8128 			 * Mark any existing pages in given range for
8129 			 * migration
8130 			 */
8131 			page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8132 			    vp, svd->offset, 1);
8133 
8134 			/*
8135 			 * If same policy set already or this is a shared
8136 			 * memory segment, don't need to try to concatenate
8137 			 * segment with adjacent ones.
8138 			 */
8139 			if (already_set || svd->type == MAP_SHARED)
8140 				break;
8141 
8142 			/*
8143 			 * Try to concatenate this segment with previous
8144 			 * one and next one, since we changed policy for
8145 			 * this one and it may be compatible with adjacent
8146 			 * ones now.
8147 			 */
8148 			prev = AS_SEGPREV(seg->s_as, seg);
8149 			next = AS_SEGNEXT(seg->s_as, seg);
8150 
8151 			if (next && next->s_ops == &segvn_ops &&
8152 			    addr + len == next->s_base)
8153 				(void) segvn_concat(seg, next, 1);
8154 
8155 			if (prev && prev->s_ops == &segvn_ops &&
8156 			    addr == prev->s_base + prev->s_size) {
8157 				/*
8158 				 * Drop lock for private data of current
8159 				 * segment before concatenating (deleting) it
8160 				 * and return IE_REATTACH to tell as_ctl() that
8161 				 * current segment has changed
8162 				 */
8163 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8164 				if (!segvn_concat(prev, seg, 1))
8165 					err = IE_REATTACH;
8166 
8167 				return (err);
8168 			}
8169 			break;
8170 
8171 		case MADV_SEQUENTIAL:
8172 			/*
8173 			 * unloading mapping guarantees
8174 			 * detection in segvn_fault
8175 			 */
8176 			ASSERT(seg->s_szc == 0);
8177 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8178 			hat_unload(seg->s_as->a_hat, addr, len,
8179 			    HAT_UNLOAD);
8180 			/* FALLTHROUGH */
8181 		case MADV_NORMAL:
8182 		case MADV_RANDOM:
8183 			svd->advice = (uchar_t)behav;
8184 			svd->pageadvice = 0;
8185 			break;
8186 		case MADV_WILLNEED:	/* handled in memcntl */
8187 		case MADV_DONTNEED:	/* handled in memcntl */
8188 		case MADV_FREE:		/* handled above */
8189 			break;
8190 		default:
8191 			err = EINVAL;
8192 		}
8193 	} else {
8194 		caddr_t			eaddr;
8195 		struct seg		*new_seg;
8196 		struct segvn_data	*new_svd;
8197 		u_offset_t		off;
8198 		caddr_t			oldeaddr;
8199 
8200 		page = seg_page(seg, addr);
8201 
8202 		segvn_vpage(seg);
8203 
8204 		switch (behav) {
8205 			struct vpage *bvpp, *evpp;
8206 
8207 		case MADV_ACCESS_LWP:
8208 		case MADV_ACCESS_MANY:
8209 		case MADV_ACCESS_DEFAULT:
8210 			/*
8211 			 * Set memory allocation policy for portion of this
8212 			 * segment
8213 			 */
8214 
8215 			/*
8216 			 * Align address and length of advice to page
8217 			 * boundaries for large pages
8218 			 */
8219 			if (seg->s_szc != 0) {
8220 				size_t	pgsz;
8221 
8222 				pgsz = page_get_pagesize(seg->s_szc);
8223 				addr = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
8224 				len = P2ROUNDUP(len, pgsz);
8225 			}
8226 
8227 			/*
8228 			 * Check to see whether policy is set already
8229 			 */
8230 			policy = lgrp_madv_to_policy(behav, len, svd->type);
8231 
8232 			anon_index = svd->anon_index + page;
8233 			off = svd->offset + (uintptr_t)(addr - seg->s_base);
8234 
8235 			if (svd->type == MAP_SHARED)
8236 				already_set = lgrp_shm_policy_set(policy, amp,
8237 				    anon_index, vp, off, len);
8238 			else
8239 				already_set =
8240 				    (policy == svd->policy_info.mem_policy);
8241 
8242 			/*
8243 			 * If policy set already and it shouldn't be reapplied,
8244 			 * don't do anything.
8245 			 */
8246 			if (already_set &&
8247 			    !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8248 				break;
8249 
8250 			/*
8251 			 * For private memory, need writers lock on
8252 			 * address space because the segment may be
8253 			 * split or concatenated when changing policy
8254 			 */
8255 			if (svd->type == MAP_PRIVATE &&
8256 			    AS_READ_HELD(seg->s_as, &seg->s_as->a_lock)) {
8257 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8258 				return (IE_RETRY);
8259 			}
8260 
8261 			/*
8262 			 * Mark any existing pages in given range for
8263 			 * migration
8264 			 */
8265 			page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8266 			    vp, svd->offset, 1);
8267 
8268 			/*
8269 			 * Don't need to try to split or concatenate
8270 			 * segments, since policy is same or this is a shared
8271 			 * memory segment
8272 			 */
8273 			if (already_set || svd->type == MAP_SHARED)
8274 				break;
8275 
8276 			if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
8277 				ASSERT(svd->amp == NULL);
8278 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
8279 				ASSERT(svd->softlockcnt == 0);
8280 				hat_leave_region(seg->s_as->a_hat, svd->rcookie,
8281 				    HAT_REGION_TEXT);
8282 				svd->rcookie = HAT_INVALID_REGION_COOKIE;
8283 			}
8284 
8285 			/*
8286 			 * Split off new segment if advice only applies to a
8287 			 * portion of existing segment starting in middle
8288 			 */
8289 			new_seg = NULL;
8290 			eaddr = addr + len;
8291 			oldeaddr = seg->s_base + seg->s_size;
8292 			if (addr > seg->s_base) {
8293 				/*
8294 				 * Must flush I/O page cache
8295 				 * before splitting segment
8296 				 */
8297 				if (svd->softlockcnt > 0)
8298 					segvn_purge(seg);
8299 
8300 				/*
8301 				 * Split segment and return IE_REATTACH to tell
8302 				 * as_ctl() that current segment changed
8303 				 */
8304 				new_seg = segvn_split_seg(seg, addr);
8305 				new_svd = (struct segvn_data *)new_seg->s_data;
8306 				err = IE_REATTACH;
8307 
8308 				/*
8309 				 * If new segment ends where old one
8310 				 * did, try to concatenate the new
8311 				 * segment with next one.
8312 				 */
8313 				if (eaddr == oldeaddr) {
8314 					/*
8315 					 * Set policy for new segment
8316 					 */
8317 					(void) lgrp_privm_policy_set(policy,
8318 					    &new_svd->policy_info,
8319 					    new_seg->s_size);
8320 
8321 					next = AS_SEGNEXT(new_seg->s_as,
8322 					    new_seg);
8323 
8324 					if (next &&
8325 					    next->s_ops == &segvn_ops &&
8326 					    eaddr == next->s_base)
8327 						(void) segvn_concat(new_seg,
8328 						    next, 1);
8329 				}
8330 			}
8331 
8332 			/*
8333 			 * Split off end of existing segment if advice only
8334 			 * applies to a portion of segment ending before
8335 			 * end of the existing segment
8336 			 */
8337 			if (eaddr < oldeaddr) {
8338 				/*
8339 				 * Must flush I/O page cache
8340 				 * before splitting segment
8341 				 */
8342 				if (svd->softlockcnt > 0)
8343 					segvn_purge(seg);
8344 
8345 				/*
8346 				 * If beginning of old segment was already
8347 				 * split off, use new segment to split end off
8348 				 * from.
8349 				 */
8350 				if (new_seg != NULL && new_seg != seg) {
8351 					/*
8352 					 * Split segment
8353 					 */
8354 					(void) segvn_split_seg(new_seg, eaddr);
8355 
8356 					/*
8357 					 * Set policy for new segment
8358 					 */
8359 					(void) lgrp_privm_policy_set(policy,
8360 					    &new_svd->policy_info,
8361 					    new_seg->s_size);
8362 				} else {
8363 					/*
8364 					 * Split segment and return IE_REATTACH
8365 					 * to tell as_ctl() that current
8366 					 * segment changed
8367 					 */
8368 					(void) segvn_split_seg(seg, eaddr);
8369 					err = IE_REATTACH;
8370 
8371 					(void) lgrp_privm_policy_set(policy,
8372 					    &svd->policy_info, seg->s_size);
8373 
8374 					/*
8375 					 * If new segment starts where old one
8376 					 * did, try to concatenate it with
8377 					 * previous segment.
8378 					 */
8379 					if (addr == seg->s_base) {
8380 						prev = AS_SEGPREV(seg->s_as,
8381 						    seg);
8382 
8383 						/*
8384 						 * Drop lock for private data
8385 						 * of current segment before
8386 						 * concatenating (deleting) it
8387 						 */
8388 						if (prev &&
8389 						    prev->s_ops ==
8390 						    &segvn_ops &&
8391 						    addr == prev->s_base +
8392 						    prev->s_size) {
8393 							SEGVN_LOCK_EXIT(
8394 							    seg->s_as,
8395 							    &svd->lock);
8396 							(void) segvn_concat(
8397 							    prev, seg, 1);
8398 							return (err);
8399 						}
8400 					}
8401 				}
8402 			}
8403 			break;
8404 		case MADV_SEQUENTIAL:
8405 			ASSERT(seg->s_szc == 0);
8406 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8407 			hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
8408 			/* FALLTHROUGH */
8409 		case MADV_NORMAL:
8410 		case MADV_RANDOM:
8411 			bvpp = &svd->vpage[page];
8412 			evpp = &svd->vpage[page + (len >> PAGESHIFT)];
8413 			for (; bvpp < evpp; bvpp++)
8414 				VPP_SETADVICE(bvpp, behav);
8415 			svd->advice = MADV_NORMAL;
8416 			break;
8417 		case MADV_WILLNEED:	/* handled in memcntl */
8418 		case MADV_DONTNEED:	/* handled in memcntl */
8419 		case MADV_FREE:		/* handled above */
8420 			break;
8421 		default:
8422 			err = EINVAL;
8423 		}
8424 	}
8425 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8426 	return (err);
8427 }
8428 
8429 /*
8430  * Create a vpage structure for this seg.
8431  */
8432 static void
8433 segvn_vpage(struct seg *seg)
8434 {
8435 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8436 	struct vpage *vp, *evp;
8437 
8438 	ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
8439 
8440 	/*
8441 	 * If no vpage structure exists, allocate one.  Copy the protections
8442 	 * and the advice from the segment itself to the individual pages.
8443 	 */
8444 	if (svd->vpage == NULL) {
8445 		svd->pageadvice = 1;
8446 		svd->vpage = kmem_zalloc(seg_pages(seg) * sizeof (struct vpage),
8447 		    KM_SLEEP);
8448 		evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
8449 		for (vp = svd->vpage; vp < evp; vp++) {
8450 			VPP_SETPROT(vp, svd->prot);
8451 			VPP_SETADVICE(vp, svd->advice);
8452 		}
8453 	}
8454 }
8455 
8456 /*
8457  * Dump the pages belonging to this segvn segment.
8458  */
8459 static void
8460 segvn_dump(struct seg *seg)
8461 {
8462 	struct segvn_data *svd;
8463 	page_t *pp;
8464 	struct anon_map *amp;
8465 	ulong_t	anon_index;
8466 	struct vnode *vp;
8467 	u_offset_t off, offset;
8468 	pfn_t pfn;
8469 	pgcnt_t page, npages;
8470 	caddr_t addr;
8471 
8472 	npages = seg_pages(seg);
8473 	svd = (struct segvn_data *)seg->s_data;
8474 	vp = svd->vp;
8475 	off = offset = svd->offset;
8476 	addr = seg->s_base;
8477 
8478 	if ((amp = svd->amp) != NULL) {
8479 		anon_index = svd->anon_index;
8480 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8481 	}
8482 
8483 	for (page = 0; page < npages; page++, offset += PAGESIZE) {
8484 		struct anon *ap;
8485 		int we_own_it = 0;
8486 
8487 		if (amp && (ap = anon_get_ptr(svd->amp->ahp, anon_index++))) {
8488 			swap_xlate_nopanic(ap, &vp, &off);
8489 		} else {
8490 			vp = svd->vp;
8491 			off = offset;
8492 		}
8493 
8494 		/*
8495 		 * If pp == NULL, the page either does not exist
8496 		 * or is exclusively locked.  So determine if it
8497 		 * exists before searching for it.
8498 		 */
8499 
8500 		if ((pp = page_lookup_nowait(vp, off, SE_SHARED)))
8501 			we_own_it = 1;
8502 		else
8503 			pp = page_exists(vp, off);
8504 
8505 		if (pp) {
8506 			pfn = page_pptonum(pp);
8507 			dump_addpage(seg->s_as, addr, pfn);
8508 			if (we_own_it)
8509 				page_unlock(pp);
8510 		}
8511 		addr += PAGESIZE;
8512 		dump_timeleft = dump_timeout;
8513 	}
8514 
8515 	if (amp != NULL)
8516 		ANON_LOCK_EXIT(&amp->a_rwlock);
8517 }
8518 
8519 #ifdef DEBUG
8520 static uint32_t segvn_pglock_mtbf = 0;
8521 #endif
8522 
8523 #define	PCACHE_SHWLIST		((page_t *)-2)
8524 #define	NOPCACHE_SHWLIST	((page_t *)-1)
8525 
8526 /*
8527  * Lock/Unlock anon pages over a given range. Return shadow list. This routine
8528  * uses global segment pcache to cache shadow lists (i.e. pp arrays) of pages
8529  * to avoid the overhead of per page locking, unlocking for subsequent IOs to
8530  * the same parts of the segment. Currently shadow list creation is only
8531  * supported for pure anon segments. MAP_PRIVATE segment pcache entries are
8532  * tagged with segment pointer, starting virtual address and length. This
8533  * approach for MAP_SHARED segments may add many pcache entries for the same
8534  * set of pages and lead to long hash chains that decrease pcache lookup
8535  * performance. To avoid this issue for shared segments shared anon map and
8536  * starting anon index are used for pcache entry tagging. This allows all
8537  * segments to share pcache entries for the same anon range and reduces pcache
8538  * chain's length as well as memory overhead from duplicate shadow lists and
8539  * pcache entries.
8540  *
8541  * softlockcnt field in segvn_data structure counts the number of F_SOFTLOCK'd
8542  * pages via segvn_fault() and pagelock'd pages via this routine. But pagelock
8543  * part of softlockcnt accounting is done differently for private and shared
8544  * segments. In private segment case softlock is only incremented when a new
8545  * shadow list is created but not when an existing one is found via
8546  * seg_plookup(). pcache entries have reference count incremented/decremented
8547  * by each seg_plookup()/seg_pinactive() operation. Only entries that have 0
8548  * reference count can be purged (and purging is needed before segment can be
8549  * freed). When a private segment pcache entry is purged segvn_reclaim() will
8550  * decrement softlockcnt. Since in private segment case each of its pcache
8551  * entries only belongs to this segment we can expect that when
8552  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8553  * segment purge will succeed and softlockcnt will drop to 0. In shared
8554  * segment case reference count in pcache entry counts active locks from many
8555  * different segments so we can't expect segment purging to succeed even when
8556  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8557  * segment. To be able to determine when there're no pending pagelocks in
8558  * shared segment case we don't rely on purging to make softlockcnt drop to 0
8559  * but instead softlockcnt is incremented and decremented for every
8560  * segvn_pagelock(L_PAGELOCK/L_PAGEUNLOCK) call regardless if a new shadow
8561  * list was created or an existing one was found. When softlockcnt drops to 0
8562  * this segment no longer has any claims for pcached shadow lists and the
8563  * segment can be freed even if there're still active pcache entries
8564  * shared by this segment anon map. Shared segment pcache entries belong to
8565  * anon map and are typically removed when anon map is freed after all
8566  * processes destroy the segments that use this anon map.
8567  */
8568 static int
8569 segvn_pagelock(struct seg *seg, caddr_t addr, size_t len, struct page ***ppp,
8570     enum lock_type type, enum seg_rw rw)
8571 {
8572 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8573 	size_t np;
8574 	pgcnt_t adjustpages;
8575 	pgcnt_t npages;
8576 	ulong_t anon_index;
8577 	uint_t protchk = (rw == S_READ) ? PROT_READ : PROT_WRITE;
8578 	uint_t error;
8579 	struct anon_map *amp;
8580 	pgcnt_t anpgcnt;
8581 	struct page **pplist, **pl, *pp;
8582 	caddr_t a;
8583 	size_t page;
8584 	caddr_t lpgaddr, lpgeaddr;
8585 	anon_sync_obj_t cookie;
8586 	int anlock;
8587 	struct anon_map *pamp;
8588 	caddr_t paddr;
8589 	seg_preclaim_cbfunc_t preclaim_callback;
8590 	size_t pgsz;
8591 	int use_pcache;
8592 	size_t wlen;
8593 	uint_t pflags = 0;
8594 	int sftlck_sbase = 0;
8595 	int sftlck_send = 0;
8596 
8597 #ifdef DEBUG
8598 	if (type == L_PAGELOCK && segvn_pglock_mtbf) {
8599 		hrtime_t ts = gethrtime();
8600 		if ((ts % segvn_pglock_mtbf) == 0) {
8601 			return (ENOTSUP);
8602 		}
8603 		if ((ts % segvn_pglock_mtbf) == 1) {
8604 			return (EFAULT);
8605 		}
8606 	}
8607 #endif
8608 
8609 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_START,
8610 	    "segvn_pagelock: start seg %p addr %p", seg, addr);
8611 
8612 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
8613 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
8614 
8615 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8616 
8617 	/*
8618 	 * for now we only support pagelock to anon memory. We would have to
8619 	 * check protections for vnode objects and call into the vnode driver.
8620 	 * That's too much for a fast path. Let the fault entry point handle
8621 	 * it.
8622 	 */
8623 	if (svd->vp != NULL) {
8624 		if (type == L_PAGELOCK) {
8625 			error = ENOTSUP;
8626 			goto out;
8627 		}
8628 		panic("segvn_pagelock(L_PAGEUNLOCK): vp != NULL");
8629 	}
8630 	if ((amp = svd->amp) == NULL) {
8631 		if (type == L_PAGELOCK) {
8632 			error = EFAULT;
8633 			goto out;
8634 		}
8635 		panic("segvn_pagelock(L_PAGEUNLOCK): amp == NULL");
8636 	}
8637 	if (rw != S_READ && rw != S_WRITE) {
8638 		if (type == L_PAGELOCK) {
8639 			error = ENOTSUP;
8640 			goto out;
8641 		}
8642 		panic("segvn_pagelock(L_PAGEUNLOCK): bad rw");
8643 	}
8644 
8645 	if (seg->s_szc != 0) {
8646 		/*
8647 		 * We are adjusting the pagelock region to the large page size
8648 		 * boundary because the unlocked part of a large page cannot
8649 		 * be freed anyway unless all constituent pages of a large
8650 		 * page are locked. Bigger regions reduce pcache chain length
8651 		 * and improve lookup performance. The tradeoff is that the
8652 		 * very first segvn_pagelock() call for a given page is more
8653 		 * expensive if only 1 page_t is needed for IO. This is only
8654 		 * an issue if pcache entry doesn't get reused by several
8655 		 * subsequent calls. We optimize here for the case when pcache
8656 		 * is heavily used by repeated IOs to the same address range.
8657 		 *
8658 		 * Note segment's page size cannot change while we are holding
8659 		 * as lock.  And then it cannot change while softlockcnt is
8660 		 * not 0. This will allow us to correctly recalculate large
8661 		 * page size region for the matching pageunlock/reclaim call
8662 		 * since as_pageunlock() caller must always match
8663 		 * as_pagelock() call's addr and len.
8664 		 *
8665 		 * For pageunlock *ppp points to the pointer of page_t that
8666 		 * corresponds to the real unadjusted start address. Similar
8667 		 * for pagelock *ppp must point to the pointer of page_t that
8668 		 * corresponds to the real unadjusted start address.
8669 		 */
8670 		pgsz = page_get_pagesize(seg->s_szc);
8671 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
8672 		adjustpages = btop((uintptr_t)(addr - lpgaddr));
8673 	} else if (len < segvn_pglock_comb_thrshld) {
8674 		lpgaddr = addr;
8675 		lpgeaddr = addr + len;
8676 		adjustpages = 0;
8677 		pgsz = PAGESIZE;
8678 	} else {
8679 		/*
8680 		 * Align the address range of large enough requests to allow
8681 		 * combining of different shadow lists into 1 to reduce memory
8682 		 * overhead from potentially overlapping large shadow lists
8683 		 * (worst case is we have a 1MB IO into buffers with start
8684 		 * addresses separated by 4K).  Alignment is only possible if
8685 		 * padded chunks have sufficient access permissions. Note
8686 		 * permissions won't change between L_PAGELOCK and
8687 		 * L_PAGEUNLOCK calls since non 0 softlockcnt will force
8688 		 * segvn_setprot() to wait until softlockcnt drops to 0. This
8689 		 * allows us to determine in L_PAGEUNLOCK the same range we
8690 		 * computed in L_PAGELOCK.
8691 		 *
8692 		 * If alignment is limited by segment ends set
8693 		 * sftlck_sbase/sftlck_send flags. In L_PAGELOCK case when
8694 		 * these flags are set bump softlockcnt_sbase/softlockcnt_send
8695 		 * per segment counters. In L_PAGEUNLOCK case decrease
8696 		 * softlockcnt_sbase/softlockcnt_send counters if
8697 		 * sftlck_sbase/sftlck_send flags are set.  When
8698 		 * softlockcnt_sbase/softlockcnt_send are non 0
8699 		 * segvn_concat()/segvn_extend_prev()/segvn_extend_next()
8700 		 * won't merge the segments. This restriction combined with
8701 		 * restriction on segment unmapping and splitting for segments
8702 		 * that have non 0 softlockcnt allows L_PAGEUNLOCK to
8703 		 * correctly determine the same range that was previously
8704 		 * locked by matching L_PAGELOCK.
8705 		 */
8706 		pflags = SEGP_PSHIFT | (segvn_pglock_comb_bshift << 16);
8707 		pgsz = PAGESIZE;
8708 		if (svd->type == MAP_PRIVATE) {
8709 			lpgaddr = (caddr_t)P2ALIGN((uintptr_t)addr,
8710 			    segvn_pglock_comb_balign);
8711 			if (lpgaddr < seg->s_base) {
8712 				lpgaddr = seg->s_base;
8713 				sftlck_sbase = 1;
8714 			}
8715 		} else {
8716 			ulong_t aix = svd->anon_index + seg_page(seg, addr);
8717 			ulong_t aaix = P2ALIGN(aix, segvn_pglock_comb_palign);
8718 			if (aaix < svd->anon_index) {
8719 				lpgaddr = seg->s_base;
8720 				sftlck_sbase = 1;
8721 			} else {
8722 				lpgaddr = addr - ptob(aix - aaix);
8723 				ASSERT(lpgaddr >= seg->s_base);
8724 			}
8725 		}
8726 		if (svd->pageprot && lpgaddr != addr) {
8727 			struct vpage *vp = &svd->vpage[seg_page(seg, lpgaddr)];
8728 			struct vpage *evp = &svd->vpage[seg_page(seg, addr)];
8729 			while (vp < evp) {
8730 				if ((VPP_PROT(vp) & protchk) == 0) {
8731 					break;
8732 				}
8733 				vp++;
8734 			}
8735 			if (vp < evp) {
8736 				lpgaddr = addr;
8737 				pflags = 0;
8738 			}
8739 		}
8740 		lpgeaddr = addr + len;
8741 		if (pflags) {
8742 			if (svd->type == MAP_PRIVATE) {
8743 				lpgeaddr = (caddr_t)P2ROUNDUP(
8744 				    (uintptr_t)lpgeaddr,
8745 				    segvn_pglock_comb_balign);
8746 			} else {
8747 				ulong_t aix = svd->anon_index +
8748 				    seg_page(seg, lpgeaddr);
8749 				ulong_t aaix = P2ROUNDUP(aix,
8750 				    segvn_pglock_comb_palign);
8751 				if (aaix < aix) {
8752 					lpgeaddr = 0;
8753 				} else {
8754 					lpgeaddr += ptob(aaix - aix);
8755 				}
8756 			}
8757 			if (lpgeaddr == 0 ||
8758 			    lpgeaddr > seg->s_base + seg->s_size) {
8759 				lpgeaddr = seg->s_base + seg->s_size;
8760 				sftlck_send = 1;
8761 			}
8762 		}
8763 		if (svd->pageprot && lpgeaddr != addr + len) {
8764 			struct vpage *vp;
8765 			struct vpage *evp;
8766 
8767 			vp = &svd->vpage[seg_page(seg, addr + len)];
8768 			evp = &svd->vpage[seg_page(seg, lpgeaddr)];
8769 
8770 			while (vp < evp) {
8771 				if ((VPP_PROT(vp) & protchk) == 0) {
8772 					break;
8773 				}
8774 				vp++;
8775 			}
8776 			if (vp < evp) {
8777 				lpgeaddr = addr + len;
8778 			}
8779 		}
8780 		adjustpages = btop((uintptr_t)(addr - lpgaddr));
8781 	}
8782 
8783 	/*
8784 	 * For MAP_SHARED segments we create pcache entries tagged by amp and
8785 	 * anon index so that we can share pcache entries with other segments
8786 	 * that map this amp.  For private segments pcache entries are tagged
8787 	 * with segment and virtual address.
8788 	 */
8789 	if (svd->type == MAP_SHARED) {
8790 		pamp = amp;
8791 		paddr = (caddr_t)((lpgaddr - seg->s_base) +
8792 		    ptob(svd->anon_index));
8793 		preclaim_callback = shamp_reclaim;
8794 	} else {
8795 		pamp = NULL;
8796 		paddr = lpgaddr;
8797 		preclaim_callback = segvn_reclaim;
8798 	}
8799 
8800 	if (type == L_PAGEUNLOCK) {
8801 		VM_STAT_ADD(segvnvmstats.pagelock[0]);
8802 
8803 		/*
8804 		 * update hat ref bits for /proc. We need to make sure
8805 		 * that threads tracing the ref and mod bits of the
8806 		 * address space get the right data.
8807 		 * Note: page ref and mod bits are updated at reclaim time
8808 		 */
8809 		if (seg->s_as->a_vbits) {
8810 			for (a = addr; a < addr + len; a += PAGESIZE) {
8811 				if (rw == S_WRITE) {
8812 					hat_setstat(seg->s_as, a,
8813 					    PAGESIZE, P_REF | P_MOD);
8814 				} else {
8815 					hat_setstat(seg->s_as, a,
8816 					    PAGESIZE, P_REF);
8817 				}
8818 			}
8819 		}
8820 
8821 		/*
8822 		 * Check the shadow list entry after the last page used in
8823 		 * this IO request. If it's NOPCACHE_SHWLIST the shadow list
8824 		 * was not inserted into pcache and is not large page
8825 		 * adjusted.  In this case call reclaim callback directly and
8826 		 * don't adjust the shadow list start and size for large
8827 		 * pages.
8828 		 */
8829 		npages = btop(len);
8830 		if ((*ppp)[npages] == NOPCACHE_SHWLIST) {
8831 			void *ptag;
8832 			if (pamp != NULL) {
8833 				ASSERT(svd->type == MAP_SHARED);
8834 				ptag = (void *)pamp;
8835 				paddr = (caddr_t)((addr - seg->s_base) +
8836 				    ptob(svd->anon_index));
8837 			} else {
8838 				ptag = (void *)seg;
8839 				paddr = addr;
8840 			}
8841 			(*preclaim_callback)(ptag, paddr, len, *ppp, rw, 0);
8842 		} else {
8843 			ASSERT((*ppp)[npages] == PCACHE_SHWLIST ||
8844 			    IS_SWAPFSVP((*ppp)[npages]->p_vnode));
8845 			len = lpgeaddr - lpgaddr;
8846 			npages = btop(len);
8847 			seg_pinactive(seg, pamp, paddr, len,
8848 			    *ppp - adjustpages, rw, pflags, preclaim_callback);
8849 		}
8850 
8851 		if (pamp != NULL) {
8852 			ASSERT(svd->type == MAP_SHARED);
8853 			ASSERT(svd->softlockcnt >= npages);
8854 			atomic_add_long((ulong_t *)&svd->softlockcnt, -npages);
8855 		}
8856 
8857 		if (sftlck_sbase) {
8858 			ASSERT(svd->softlockcnt_sbase > 0);
8859 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, -1);
8860 		}
8861 		if (sftlck_send) {
8862 			ASSERT(svd->softlockcnt_send > 0);
8863 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, -1);
8864 		}
8865 
8866 		/*
8867 		 * If someone is blocked while unmapping, we purge
8868 		 * segment page cache and thus reclaim pplist synchronously
8869 		 * without waiting for seg_pasync_thread. This speeds up
8870 		 * unmapping in cases where munmap(2) is called, while
8871 		 * raw async i/o is still in progress or where a thread
8872 		 * exits on data fault in a multithreaded application.
8873 		 */
8874 		if (AS_ISUNMAPWAIT(seg->s_as)) {
8875 			if (svd->softlockcnt == 0) {
8876 				mutex_enter(&seg->s_as->a_contents);
8877 				if (AS_ISUNMAPWAIT(seg->s_as)) {
8878 					AS_CLRUNMAPWAIT(seg->s_as);
8879 					cv_broadcast(&seg->s_as->a_cv);
8880 				}
8881 				mutex_exit(&seg->s_as->a_contents);
8882 			} else if (pamp == NULL) {
8883 				/*
8884 				 * softlockcnt is not 0 and this is a
8885 				 * MAP_PRIVATE segment. Try to purge its
8886 				 * pcache entries to reduce softlockcnt.
8887 				 * If it drops to 0 segvn_reclaim()
8888 				 * will wake up a thread waiting on
8889 				 * unmapwait flag.
8890 				 *
8891 				 * We don't purge MAP_SHARED segments with non
8892 				 * 0 softlockcnt since IO is still in progress
8893 				 * for such segments.
8894 				 */
8895 				ASSERT(svd->type == MAP_PRIVATE);
8896 				segvn_purge(seg);
8897 			}
8898 		}
8899 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8900 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_UNLOCK_END,
8901 		    "segvn_pagelock: unlock seg %p addr %p", seg, addr);
8902 		return (0);
8903 	}
8904 
8905 	/* The L_PAGELOCK case ... */
8906 
8907 	VM_STAT_ADD(segvnvmstats.pagelock[1]);
8908 
8909 	/*
8910 	 * For MAP_SHARED segments we have to check protections before
8911 	 * seg_plookup() since pcache entries may be shared by many segments
8912 	 * with potentially different page protections.
8913 	 */
8914 	if (pamp != NULL) {
8915 		ASSERT(svd->type == MAP_SHARED);
8916 		if (svd->pageprot == 0) {
8917 			if ((svd->prot & protchk) == 0) {
8918 				error = EACCES;
8919 				goto out;
8920 			}
8921 		} else {
8922 			/*
8923 			 * check page protections
8924 			 */
8925 			caddr_t ea;
8926 
8927 			if (seg->s_szc) {
8928 				a = lpgaddr;
8929 				ea = lpgeaddr;
8930 			} else {
8931 				a = addr;
8932 				ea = addr + len;
8933 			}
8934 			for (; a < ea; a += pgsz) {
8935 				struct vpage *vp;
8936 
8937 				ASSERT(seg->s_szc == 0 ||
8938 				    sameprot(seg, a, pgsz));
8939 				vp = &svd->vpage[seg_page(seg, a)];
8940 				if ((VPP_PROT(vp) & protchk) == 0) {
8941 					error = EACCES;
8942 					goto out;
8943 				}
8944 			}
8945 		}
8946 	}
8947 
8948 	/*
8949 	 * try to find pages in segment page cache
8950 	 */
8951 	pplist = seg_plookup(seg, pamp, paddr, lpgeaddr - lpgaddr, rw, pflags);
8952 	if (pplist != NULL) {
8953 		if (pamp != NULL) {
8954 			npages = btop((uintptr_t)(lpgeaddr - lpgaddr));
8955 			ASSERT(svd->type == MAP_SHARED);
8956 			atomic_add_long((ulong_t *)&svd->softlockcnt,
8957 			    npages);
8958 		}
8959 		if (sftlck_sbase) {
8960 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, 1);
8961 		}
8962 		if (sftlck_send) {
8963 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, 1);
8964 		}
8965 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8966 		*ppp = pplist + adjustpages;
8967 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_HIT_END,
8968 		    "segvn_pagelock: cache hit seg %p addr %p", seg, addr);
8969 		return (0);
8970 	}
8971 
8972 	/*
8973 	 * For MAP_SHARED segments we already verified above that segment
8974 	 * protections allow this pagelock operation.
8975 	 */
8976 	if (pamp == NULL) {
8977 		ASSERT(svd->type == MAP_PRIVATE);
8978 		if (svd->pageprot == 0) {
8979 			if ((svd->prot & protchk) == 0) {
8980 				error = EACCES;
8981 				goto out;
8982 			}
8983 			if (svd->prot & PROT_WRITE) {
8984 				wlen = lpgeaddr - lpgaddr;
8985 			} else {
8986 				wlen = 0;
8987 				ASSERT(rw == S_READ);
8988 			}
8989 		} else {
8990 			int wcont = 1;
8991 			/*
8992 			 * check page protections
8993 			 */
8994 			for (a = lpgaddr, wlen = 0; a < lpgeaddr; a += pgsz) {
8995 				struct vpage *vp;
8996 
8997 				ASSERT(seg->s_szc == 0 ||
8998 				    sameprot(seg, a, pgsz));
8999 				vp = &svd->vpage[seg_page(seg, a)];
9000 				if ((VPP_PROT(vp) & protchk) == 0) {
9001 					error = EACCES;
9002 					goto out;
9003 				}
9004 				if (wcont && (VPP_PROT(vp) & PROT_WRITE)) {
9005 					wlen += pgsz;
9006 				} else {
9007 					wcont = 0;
9008 					ASSERT(rw == S_READ);
9009 				}
9010 			}
9011 		}
9012 		ASSERT(rw == S_READ || wlen == lpgeaddr - lpgaddr);
9013 		ASSERT(rw == S_WRITE || wlen <= lpgeaddr - lpgaddr);
9014 	}
9015 
9016 	/*
9017 	 * Only build large page adjusted shadow list if we expect to insert
9018 	 * it into pcache. For large enough pages it's a big overhead to
9019 	 * create a shadow list of the entire large page. But this overhead
9020 	 * should be amortized over repeated pcache hits on subsequent reuse
9021 	 * of this shadow list (IO into any range within this shadow list will
9022 	 * find it in pcache since we large page align the request for pcache
9023 	 * lookups). pcache performance is improved with bigger shadow lists
9024 	 * as it reduces the time to pcache the entire big segment and reduces
9025 	 * pcache chain length.
9026 	 */
9027 	if (seg_pinsert_check(seg, pamp, paddr,
9028 	    lpgeaddr - lpgaddr, pflags) == SEGP_SUCCESS) {
9029 		addr = lpgaddr;
9030 		len = lpgeaddr - lpgaddr;
9031 		use_pcache = 1;
9032 	} else {
9033 		use_pcache = 0;
9034 		/*
9035 		 * Since this entry will not be inserted into the pcache, we
9036 		 * will not do any adjustments to the starting address or
9037 		 * size of the memory to be locked.
9038 		 */
9039 		adjustpages = 0;
9040 	}
9041 	npages = btop(len);
9042 
9043 	pplist = kmem_alloc(sizeof (page_t *) * (npages + 1), KM_SLEEP);
9044 	pl = pplist;
9045 	*ppp = pplist + adjustpages;
9046 	/*
9047 	 * If use_pcache is 0 this shadow list is not large page adjusted.
9048 	 * Record this info in the last entry of shadow array so that
9049 	 * L_PAGEUNLOCK can determine if it should large page adjust the
9050 	 * address range to find the real range that was locked.
9051 	 */
9052 	pl[npages] = use_pcache ? PCACHE_SHWLIST : NOPCACHE_SHWLIST;
9053 
9054 	page = seg_page(seg, addr);
9055 	anon_index = svd->anon_index + page;
9056 
9057 	anlock = 0;
9058 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9059 	ASSERT(amp->a_szc >= seg->s_szc);
9060 	anpgcnt = page_get_pagecnt(amp->a_szc);
9061 	for (a = addr; a < addr + len; a += PAGESIZE, anon_index++) {
9062 		struct anon *ap;
9063 		struct vnode *vp;
9064 		u_offset_t off;
9065 
9066 		/*
9067 		 * Lock and unlock anon array only once per large page.
9068 		 * anon_array_enter() locks the root anon slot according to
9069 		 * a_szc which can't change while anon map is locked.  We lock
9070 		 * anon the first time through this loop and each time we
9071 		 * reach anon index that corresponds to a root of a large
9072 		 * page.
9073 		 */
9074 		if (a == addr || P2PHASE(anon_index, anpgcnt) == 0) {
9075 			ASSERT(anlock == 0);
9076 			anon_array_enter(amp, anon_index, &cookie);
9077 			anlock = 1;
9078 		}
9079 		ap = anon_get_ptr(amp->ahp, anon_index);
9080 
9081 		/*
9082 		 * We must never use seg_pcache for COW pages
9083 		 * because we might end up with original page still
9084 		 * lying in seg_pcache even after private page is
9085 		 * created. This leads to data corruption as
9086 		 * aio_write refers to the page still in cache
9087 		 * while all other accesses refer to the private
9088 		 * page.
9089 		 */
9090 		if (ap == NULL || ap->an_refcnt != 1) {
9091 			struct vpage *vpage;
9092 
9093 			if (seg->s_szc) {
9094 				error = EFAULT;
9095 				break;
9096 			}
9097 			if (svd->vpage != NULL) {
9098 				vpage = &svd->vpage[seg_page(seg, a)];
9099 			} else {
9100 				vpage = NULL;
9101 			}
9102 			ASSERT(anlock);
9103 			anon_array_exit(&cookie);
9104 			anlock = 0;
9105 			pp = NULL;
9106 			error = segvn_faultpage(seg->s_as->a_hat, seg, a, 0,
9107 			    vpage, &pp, 0, F_INVAL, rw, 1);
9108 			if (error) {
9109 				error = fc_decode(error);
9110 				break;
9111 			}
9112 			anon_array_enter(amp, anon_index, &cookie);
9113 			anlock = 1;
9114 			ap = anon_get_ptr(amp->ahp, anon_index);
9115 			if (ap == NULL || ap->an_refcnt != 1) {
9116 				error = EFAULT;
9117 				break;
9118 			}
9119 		}
9120 		swap_xlate(ap, &vp, &off);
9121 		pp = page_lookup_nowait(vp, off, SE_SHARED);
9122 		if (pp == NULL) {
9123 			error = EFAULT;
9124 			break;
9125 		}
9126 		if (ap->an_pvp != NULL) {
9127 			anon_swap_free(ap, pp);
9128 		}
9129 		/*
9130 		 * Unlock anon if this is the last slot in a large page.
9131 		 */
9132 		if (P2PHASE(anon_index, anpgcnt) == anpgcnt - 1) {
9133 			ASSERT(anlock);
9134 			anon_array_exit(&cookie);
9135 			anlock = 0;
9136 		}
9137 		*pplist++ = pp;
9138 	}
9139 	if (anlock) {		/* Ensure the lock is dropped */
9140 		anon_array_exit(&cookie);
9141 	}
9142 	ANON_LOCK_EXIT(&amp->a_rwlock);
9143 
9144 	if (a >= addr + len) {
9145 		atomic_add_long((ulong_t *)&svd->softlockcnt, npages);
9146 		if (pamp != NULL) {
9147 			ASSERT(svd->type == MAP_SHARED);
9148 			atomic_add_long((ulong_t *)&pamp->a_softlockcnt,
9149 			    npages);
9150 			wlen = len;
9151 		}
9152 		if (sftlck_sbase) {
9153 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, 1);
9154 		}
9155 		if (sftlck_send) {
9156 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, 1);
9157 		}
9158 		if (use_pcache) {
9159 			(void) seg_pinsert(seg, pamp, paddr, len, wlen, pl,
9160 			    rw, pflags, preclaim_callback);
9161 		}
9162 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9163 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_FILL_END,
9164 		    "segvn_pagelock: cache fill seg %p addr %p", seg, addr);
9165 		return (0);
9166 	}
9167 
9168 	pplist = pl;
9169 	np = ((uintptr_t)(a - addr)) >> PAGESHIFT;
9170 	while (np > (uint_t)0) {
9171 		ASSERT(PAGE_LOCKED(*pplist));
9172 		page_unlock(*pplist);
9173 		np--;
9174 		pplist++;
9175 	}
9176 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9177 out:
9178 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9179 	*ppp = NULL;
9180 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_MISS_END,
9181 	    "segvn_pagelock: cache miss seg %p addr %p", seg, addr);
9182 	return (error);
9183 }
9184 
9185 /*
9186  * purge any cached pages in the I/O page cache
9187  */
9188 static void
9189 segvn_purge(struct seg *seg)
9190 {
9191 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9192 
9193 	/*
9194 	 * pcache is only used by pure anon segments.
9195 	 */
9196 	if (svd->amp == NULL || svd->vp != NULL) {
9197 		return;
9198 	}
9199 
9200 	/*
9201 	 * For MAP_SHARED segments non 0 segment's softlockcnt means
9202 	 * active IO is still in progress via this segment. So we only
9203 	 * purge MAP_SHARED segments when their softlockcnt is 0.
9204 	 */
9205 	if (svd->type == MAP_PRIVATE) {
9206 		if (svd->softlockcnt) {
9207 			seg_ppurge(seg, NULL, 0);
9208 		}
9209 	} else if (svd->softlockcnt == 0 && svd->amp->a_softlockcnt != 0) {
9210 		seg_ppurge(seg, svd->amp, 0);
9211 	}
9212 }
9213 
9214 /*
9215  * If async argument is not 0 we are called from pcache async thread and don't
9216  * hold AS lock.
9217  */
9218 
9219 /*ARGSUSED*/
9220 static int
9221 segvn_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9222 	enum seg_rw rw, int async)
9223 {
9224 	struct seg *seg = (struct seg *)ptag;
9225 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9226 	pgcnt_t np, npages;
9227 	struct page **pl;
9228 
9229 	npages = np = btop(len);
9230 	ASSERT(npages);
9231 
9232 	ASSERT(svd->vp == NULL && svd->amp != NULL);
9233 	ASSERT(svd->softlockcnt >= npages);
9234 	ASSERT(async || AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9235 
9236 	pl = pplist;
9237 
9238 	ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9239 	ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9240 
9241 	while (np > (uint_t)0) {
9242 		if (rw == S_WRITE) {
9243 			hat_setrefmod(*pplist);
9244 		} else {
9245 			hat_setref(*pplist);
9246 		}
9247 		page_unlock(*pplist);
9248 		np--;
9249 		pplist++;
9250 	}
9251 
9252 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9253 
9254 	/*
9255 	 * If we are pcache async thread we don't hold AS lock. This means if
9256 	 * softlockcnt drops to 0 after the decrement below address space may
9257 	 * get freed. We can't allow it since after softlock derement to 0 we
9258 	 * still need to access as structure for possible wakeup of unmap
9259 	 * waiters. To prevent the disappearance of as we take this segment
9260 	 * segfree_syncmtx. segvn_free() also takes this mutex as a barrier to
9261 	 * make sure this routine completes before segment is freed.
9262 	 *
9263 	 * The second complication we have to deal with in async case is a
9264 	 * possibility of missed wake up of unmap wait thread. When we don't
9265 	 * hold as lock here we may take a_contents lock before unmap wait
9266 	 * thread that was first to see softlockcnt was still not 0. As a
9267 	 * result we'll fail to wake up an unmap wait thread. To avoid this
9268 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
9269 	 * to 0 when we were called by pcache async thread.  unmapwait thread
9270 	 * will not block if this flag is set.
9271 	 */
9272 	if (async) {
9273 		mutex_enter(&svd->segfree_syncmtx);
9274 	}
9275 
9276 	if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -npages)) {
9277 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
9278 			mutex_enter(&seg->s_as->a_contents);
9279 			if (async) {
9280 				AS_SETNOUNMAPWAIT(seg->s_as);
9281 			}
9282 			if (AS_ISUNMAPWAIT(seg->s_as)) {
9283 				AS_CLRUNMAPWAIT(seg->s_as);
9284 				cv_broadcast(&seg->s_as->a_cv);
9285 			}
9286 			mutex_exit(&seg->s_as->a_contents);
9287 		}
9288 	}
9289 
9290 	if (async) {
9291 		mutex_exit(&svd->segfree_syncmtx);
9292 	}
9293 	return (0);
9294 }
9295 
9296 /*ARGSUSED*/
9297 static int
9298 shamp_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9299 	enum seg_rw rw, int async)
9300 {
9301 	amp_t *amp = (amp_t *)ptag;
9302 	pgcnt_t np, npages;
9303 	struct page **pl;
9304 
9305 	npages = np = btop(len);
9306 	ASSERT(npages);
9307 	ASSERT(amp->a_softlockcnt >= npages);
9308 
9309 	pl = pplist;
9310 
9311 	ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9312 	ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9313 
9314 	while (np > (uint_t)0) {
9315 		if (rw == S_WRITE) {
9316 			hat_setrefmod(*pplist);
9317 		} else {
9318 			hat_setref(*pplist);
9319 		}
9320 		page_unlock(*pplist);
9321 		np--;
9322 		pplist++;
9323 	}
9324 
9325 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9326 
9327 	/*
9328 	 * If somebody sleeps in anonmap_purge() wake them up if a_softlockcnt
9329 	 * drops to 0. anon map can't be freed until a_softlockcnt drops to 0
9330 	 * and anonmap_purge() acquires a_purgemtx.
9331 	 */
9332 	mutex_enter(&amp->a_purgemtx);
9333 	if (!atomic_add_long_nv((ulong_t *)&amp->a_softlockcnt, -npages) &&
9334 	    amp->a_purgewait) {
9335 		amp->a_purgewait = 0;
9336 		cv_broadcast(&amp->a_purgecv);
9337 	}
9338 	mutex_exit(&amp->a_purgemtx);
9339 	return (0);
9340 }
9341 
9342 /*
9343  * get a memory ID for an addr in a given segment
9344  *
9345  * XXX only creates PAGESIZE pages if anon slots are not initialized.
9346  * At fault time they will be relocated into larger pages.
9347  */
9348 static int
9349 segvn_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
9350 {
9351 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9352 	struct anon 	*ap = NULL;
9353 	ulong_t		anon_index;
9354 	struct anon_map	*amp;
9355 	anon_sync_obj_t cookie;
9356 
9357 	if (svd->type == MAP_PRIVATE) {
9358 		memidp->val[0] = (uintptr_t)seg->s_as;
9359 		memidp->val[1] = (uintptr_t)addr;
9360 		return (0);
9361 	}
9362 
9363 	if (svd->type == MAP_SHARED) {
9364 		if (svd->vp) {
9365 			memidp->val[0] = (uintptr_t)svd->vp;
9366 			memidp->val[1] = (u_longlong_t)svd->offset +
9367 			    (uintptr_t)(addr - seg->s_base);
9368 			return (0);
9369 		} else {
9370 
9371 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
9372 			if ((amp = svd->amp) != NULL) {
9373 				anon_index = svd->anon_index +
9374 				    seg_page(seg, addr);
9375 			}
9376 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9377 
9378 			ASSERT(amp != NULL);
9379 
9380 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9381 			anon_array_enter(amp, anon_index, &cookie);
9382 			ap = anon_get_ptr(amp->ahp, anon_index);
9383 			if (ap == NULL) {
9384 				page_t		*pp;
9385 
9386 				pp = anon_zero(seg, addr, &ap, svd->cred);
9387 				if (pp == NULL) {
9388 					anon_array_exit(&cookie);
9389 					ANON_LOCK_EXIT(&amp->a_rwlock);
9390 					return (ENOMEM);
9391 				}
9392 				ASSERT(anon_get_ptr(amp->ahp, anon_index)
9393 				    == NULL);
9394 				(void) anon_set_ptr(amp->ahp, anon_index,
9395 				    ap, ANON_SLEEP);
9396 				page_unlock(pp);
9397 			}
9398 
9399 			anon_array_exit(&cookie);
9400 			ANON_LOCK_EXIT(&amp->a_rwlock);
9401 
9402 			memidp->val[0] = (uintptr_t)ap;
9403 			memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
9404 			return (0);
9405 		}
9406 	}
9407 	return (EINVAL);
9408 }
9409 
9410 static int
9411 sameprot(struct seg *seg, caddr_t a, size_t len)
9412 {
9413 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9414 	struct vpage *vpage;
9415 	spgcnt_t pages = btop(len);
9416 	uint_t prot;
9417 
9418 	if (svd->pageprot == 0)
9419 		return (1);
9420 
9421 	ASSERT(svd->vpage != NULL);
9422 
9423 	vpage = &svd->vpage[seg_page(seg, a)];
9424 	prot = VPP_PROT(vpage);
9425 	vpage++;
9426 	pages--;
9427 	while (pages-- > 0) {
9428 		if (prot != VPP_PROT(vpage))
9429 			return (0);
9430 		vpage++;
9431 	}
9432 	return (1);
9433 }
9434 
9435 /*
9436  * Get memory allocation policy info for specified address in given segment
9437  */
9438 static lgrp_mem_policy_info_t *
9439 segvn_getpolicy(struct seg *seg, caddr_t addr)
9440 {
9441 	struct anon_map		*amp;
9442 	ulong_t			anon_index;
9443 	lgrp_mem_policy_info_t	*policy_info;
9444 	struct segvn_data	*svn_data;
9445 	u_offset_t		vn_off;
9446 	vnode_t			*vp;
9447 
9448 	ASSERT(seg != NULL);
9449 
9450 	svn_data = (struct segvn_data *)seg->s_data;
9451 	if (svn_data == NULL)
9452 		return (NULL);
9453 
9454 	/*
9455 	 * Get policy info for private or shared memory
9456 	 */
9457 	if (svn_data->type != MAP_SHARED) {
9458 		if (svn_data->tr_state != SEGVN_TR_ON) {
9459 			policy_info = &svn_data->policy_info;
9460 		} else {
9461 			policy_info = &svn_data->tr_policy_info;
9462 			ASSERT(policy_info->mem_policy ==
9463 			    LGRP_MEM_POLICY_NEXT_SEG);
9464 		}
9465 	} else {
9466 		amp = svn_data->amp;
9467 		anon_index = svn_data->anon_index + seg_page(seg, addr);
9468 		vp = svn_data->vp;
9469 		vn_off = svn_data->offset + (uintptr_t)(addr - seg->s_base);
9470 		policy_info = lgrp_shm_policy_get(amp, anon_index, vp, vn_off);
9471 	}
9472 
9473 	return (policy_info);
9474 }
9475 
9476 /*ARGSUSED*/
9477 static int
9478 segvn_capable(struct seg *seg, segcapability_t capability)
9479 {
9480 	return (0);
9481 }
9482 
9483 /*
9484  * Bind text vnode segment to an amp. If we bind successfully mappings will be
9485  * established to per vnode mapping per lgroup amp pages instead of to vnode
9486  * pages. There's one amp per vnode text mapping per lgroup. Many processes
9487  * may share the same text replication amp. If a suitable amp doesn't already
9488  * exist in svntr hash table create a new one.  We may fail to bind to amp if
9489  * segment is not eligible for text replication.  Code below first checks for
9490  * these conditions. If binding is successful segment tr_state is set to on
9491  * and svd->amp points to the amp to use. Otherwise tr_state is set to off and
9492  * svd->amp remains as NULL.
9493  */
9494 static void
9495 segvn_textrepl(struct seg *seg)
9496 {
9497 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
9498 	vnode_t			*vp = svd->vp;
9499 	u_offset_t		off = svd->offset;
9500 	size_t			size = seg->s_size;
9501 	u_offset_t		eoff = off + size;
9502 	uint_t			szc = seg->s_szc;
9503 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9504 	svntr_t			*svntrp;
9505 	struct vattr		va;
9506 	proc_t			*p = seg->s_as->a_proc;
9507 	lgrp_id_t		lgrp_id;
9508 	lgrp_id_t		olid;
9509 	int			first;
9510 	struct anon_map		*amp;
9511 
9512 	ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9513 	ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9514 	ASSERT(p != NULL);
9515 	ASSERT(svd->tr_state == SEGVN_TR_INIT);
9516 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9517 	ASSERT(svd->flags & MAP_TEXT);
9518 	ASSERT(svd->type == MAP_PRIVATE);
9519 	ASSERT(vp != NULL && svd->amp == NULL);
9520 	ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
9521 	ASSERT(!(svd->flags & MAP_NORESERVE) && svd->swresv == 0);
9522 	ASSERT(seg->s_as != &kas);
9523 	ASSERT(off < eoff);
9524 	ASSERT(svntr_hashtab != NULL);
9525 
9526 	/*
9527 	 * If numa optimizations are no longer desired bail out.
9528 	 */
9529 	if (!lgrp_optimizations()) {
9530 		svd->tr_state = SEGVN_TR_OFF;
9531 		return;
9532 	}
9533 
9534 	/*
9535 	 * Avoid creating anon maps with size bigger than the file size.
9536 	 * If VOP_GETATTR() call fails bail out.
9537 	 */
9538 	va.va_mask = AT_SIZE | AT_MTIME | AT_CTIME;
9539 	if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL) != 0) {
9540 		svd->tr_state = SEGVN_TR_OFF;
9541 		SEGVN_TR_ADDSTAT(gaerr);
9542 		return;
9543 	}
9544 	if (btopr(va.va_size) < btopr(eoff)) {
9545 		svd->tr_state = SEGVN_TR_OFF;
9546 		SEGVN_TR_ADDSTAT(overmap);
9547 		return;
9548 	}
9549 
9550 	/*
9551 	 * VVMEXEC may not be set yet if exec() prefaults text segment. Set
9552 	 * this flag now before vn_is_mapped(V_WRITE) so that MAP_SHARED
9553 	 * mapping that checks if trcache for this vnode needs to be
9554 	 * invalidated can't miss us.
9555 	 */
9556 	if (!(vp->v_flag & VVMEXEC)) {
9557 		mutex_enter(&vp->v_lock);
9558 		vp->v_flag |= VVMEXEC;
9559 		mutex_exit(&vp->v_lock);
9560 	}
9561 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9562 	/*
9563 	 * Bail out if potentially MAP_SHARED writable mappings exist to this
9564 	 * vnode.  We don't want to use old file contents from existing
9565 	 * replicas if this mapping was established after the original file
9566 	 * was changed.
9567 	 */
9568 	if (vn_is_mapped(vp, V_WRITE)) {
9569 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9570 		svd->tr_state = SEGVN_TR_OFF;
9571 		SEGVN_TR_ADDSTAT(wrcnt);
9572 		return;
9573 	}
9574 	svntrp = svntr_hashtab[hash].tr_head;
9575 	for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9576 		ASSERT(svntrp->tr_refcnt != 0);
9577 		if (svntrp->tr_vp != vp) {
9578 			continue;
9579 		}
9580 
9581 		/*
9582 		 * Bail out if the file or its attributes were changed after
9583 		 * this replication entry was created since we need to use the
9584 		 * latest file contents. Note that mtime test alone is not
9585 		 * sufficient because a user can explicitly change mtime via
9586 		 * utimes(2) interfaces back to the old value after modifiying
9587 		 * the file contents. To detect this case we also have to test
9588 		 * ctime which among other things records the time of the last
9589 		 * mtime change by utimes(2). ctime is not changed when the file
9590 		 * is only read or executed so we expect that typically existing
9591 		 * replication amp's can be used most of the time.
9592 		 */
9593 		if (!svntrp->tr_valid ||
9594 		    svntrp->tr_mtime.tv_sec != va.va_mtime.tv_sec ||
9595 		    svntrp->tr_mtime.tv_nsec != va.va_mtime.tv_nsec ||
9596 		    svntrp->tr_ctime.tv_sec != va.va_ctime.tv_sec ||
9597 		    svntrp->tr_ctime.tv_nsec != va.va_ctime.tv_nsec) {
9598 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9599 			svd->tr_state = SEGVN_TR_OFF;
9600 			SEGVN_TR_ADDSTAT(stale);
9601 			return;
9602 		}
9603 		/*
9604 		 * if off, eoff and szc match current segment we found the
9605 		 * existing entry we can use.
9606 		 */
9607 		if (svntrp->tr_off == off && svntrp->tr_eoff == eoff &&
9608 		    svntrp->tr_szc == szc) {
9609 			break;
9610 		}
9611 		/*
9612 		 * Don't create different but overlapping in file offsets
9613 		 * entries to avoid replication of the same file pages more
9614 		 * than once per lgroup.
9615 		 */
9616 		if ((off >= svntrp->tr_off && off < svntrp->tr_eoff) ||
9617 		    (eoff > svntrp->tr_off && eoff <= svntrp->tr_eoff)) {
9618 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9619 			svd->tr_state = SEGVN_TR_OFF;
9620 			SEGVN_TR_ADDSTAT(overlap);
9621 			return;
9622 		}
9623 	}
9624 	/*
9625 	 * If we didn't find existing entry create a new one.
9626 	 */
9627 	if (svntrp == NULL) {
9628 		svntrp = kmem_cache_alloc(svntr_cache, KM_NOSLEEP);
9629 		if (svntrp == NULL) {
9630 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9631 			svd->tr_state = SEGVN_TR_OFF;
9632 			SEGVN_TR_ADDSTAT(nokmem);
9633 			return;
9634 		}
9635 #ifdef DEBUG
9636 		{
9637 			lgrp_id_t i;
9638 			for (i = 0; i < NLGRPS_MAX; i++) {
9639 				ASSERT(svntrp->tr_amp[i] == NULL);
9640 			}
9641 		}
9642 #endif /* DEBUG */
9643 		svntrp->tr_vp = vp;
9644 		svntrp->tr_off = off;
9645 		svntrp->tr_eoff = eoff;
9646 		svntrp->tr_szc = szc;
9647 		svntrp->tr_valid = 1;
9648 		svntrp->tr_mtime = va.va_mtime;
9649 		svntrp->tr_ctime = va.va_ctime;
9650 		svntrp->tr_refcnt = 0;
9651 		svntrp->tr_next = svntr_hashtab[hash].tr_head;
9652 		svntr_hashtab[hash].tr_head = svntrp;
9653 	}
9654 	first = 1;
9655 again:
9656 	/*
9657 	 * We want to pick a replica with pages on main thread's (t_tid = 1,
9658 	 * aka T1) lgrp. Currently text replication is only optimized for
9659 	 * workloads that either have all threads of a process on the same
9660 	 * lgrp or execute their large text primarily on main thread.
9661 	 */
9662 	lgrp_id = p->p_t1_lgrpid;
9663 	if (lgrp_id == LGRP_NONE) {
9664 		/*
9665 		 * In case exec() prefaults text on non main thread use
9666 		 * current thread lgrpid.  It will become main thread anyway
9667 		 * soon.
9668 		 */
9669 		lgrp_id = lgrp_home_id(curthread);
9670 	}
9671 	/*
9672 	 * Set p_tr_lgrpid to lgrpid if it hasn't been set yet.  Otherwise
9673 	 * just set it to NLGRPS_MAX if it's different from current process T1
9674 	 * home lgrp.  p_tr_lgrpid is used to detect if process uses text
9675 	 * replication and T1 new home is different from lgrp used for text
9676 	 * replication. When this happens asyncronous segvn thread rechecks if
9677 	 * segments should change lgrps used for text replication.  If we fail
9678 	 * to set p_tr_lgrpid with cas32 then set it to NLGRPS_MAX without cas
9679 	 * if it's not already NLGRPS_MAX and not equal lgrp_id we want to
9680 	 * use.  We don't need to use cas in this case because another thread
9681 	 * that races in between our non atomic check and set may only change
9682 	 * p_tr_lgrpid to NLGRPS_MAX at this point.
9683 	 */
9684 	ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9685 	olid = p->p_tr_lgrpid;
9686 	if (lgrp_id != olid && olid != NLGRPS_MAX) {
9687 		lgrp_id_t nlid = (olid == LGRP_NONE) ? lgrp_id : NLGRPS_MAX;
9688 		if (cas32((uint32_t *)&p->p_tr_lgrpid, olid, nlid) != olid) {
9689 			olid = p->p_tr_lgrpid;
9690 			ASSERT(olid != LGRP_NONE);
9691 			if (olid != lgrp_id && olid != NLGRPS_MAX) {
9692 				p->p_tr_lgrpid = NLGRPS_MAX;
9693 			}
9694 		}
9695 		ASSERT(p->p_tr_lgrpid != LGRP_NONE);
9696 		membar_producer();
9697 		/*
9698 		 * lgrp_move_thread() won't schedule async recheck after
9699 		 * p->p_t1_lgrpid update unless p->p_tr_lgrpid is not
9700 		 * LGRP_NONE. Recheck p_t1_lgrpid once now that p->p_tr_lgrpid
9701 		 * is not LGRP_NONE.
9702 		 */
9703 		if (first && p->p_t1_lgrpid != LGRP_NONE &&
9704 		    p->p_t1_lgrpid != lgrp_id) {
9705 			first = 0;
9706 			goto again;
9707 		}
9708 	}
9709 	/*
9710 	 * If no amp was created yet for lgrp_id create a new one as long as
9711 	 * we have enough memory to afford it.
9712 	 */
9713 	if ((amp = svntrp->tr_amp[lgrp_id]) == NULL) {
9714 		size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
9715 		if (trmem > segvn_textrepl_max_bytes) {
9716 			SEGVN_TR_ADDSTAT(normem);
9717 			goto fail;
9718 		}
9719 		if (anon_try_resv_zone(size, NULL) == 0) {
9720 			SEGVN_TR_ADDSTAT(noanon);
9721 			goto fail;
9722 		}
9723 		amp = anonmap_alloc(size, size, ANON_NOSLEEP);
9724 		if (amp == NULL) {
9725 			anon_unresv_zone(size, NULL);
9726 			SEGVN_TR_ADDSTAT(nokmem);
9727 			goto fail;
9728 		}
9729 		ASSERT(amp->refcnt == 1);
9730 		amp->a_szc = szc;
9731 		svntrp->tr_amp[lgrp_id] = amp;
9732 		SEGVN_TR_ADDSTAT(newamp);
9733 	}
9734 	svntrp->tr_refcnt++;
9735 	ASSERT(svd->svn_trnext == NULL);
9736 	ASSERT(svd->svn_trprev == NULL);
9737 	svd->svn_trnext = svntrp->tr_svnhead;
9738 	svd->svn_trprev = NULL;
9739 	if (svntrp->tr_svnhead != NULL) {
9740 		svntrp->tr_svnhead->svn_trprev = svd;
9741 	}
9742 	svntrp->tr_svnhead = svd;
9743 	ASSERT(amp->a_szc == szc && amp->size == size && amp->swresv == size);
9744 	ASSERT(amp->refcnt >= 1);
9745 	svd->amp = amp;
9746 	svd->anon_index = 0;
9747 	svd->tr_policy_info.mem_policy = LGRP_MEM_POLICY_NEXT_SEG;
9748 	svd->tr_policy_info.mem_lgrpid = lgrp_id;
9749 	svd->tr_state = SEGVN_TR_ON;
9750 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9751 	SEGVN_TR_ADDSTAT(repl);
9752 	return;
9753 fail:
9754 	ASSERT(segvn_textrepl_bytes >= size);
9755 	atomic_add_long(&segvn_textrepl_bytes, -size);
9756 	ASSERT(svntrp != NULL);
9757 	ASSERT(svntrp->tr_amp[lgrp_id] == NULL);
9758 	if (svntrp->tr_refcnt == 0) {
9759 		ASSERT(svntrp == svntr_hashtab[hash].tr_head);
9760 		svntr_hashtab[hash].tr_head = svntrp->tr_next;
9761 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9762 		kmem_cache_free(svntr_cache, svntrp);
9763 	} else {
9764 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9765 	}
9766 	svd->tr_state = SEGVN_TR_OFF;
9767 }
9768 
9769 /*
9770  * Convert seg back to regular vnode mapping seg by unbinding it from its text
9771  * replication amp.  This routine is most typically called when segment is
9772  * unmapped but can also be called when segment no longer qualifies for text
9773  * replication (e.g. due to protection changes). If unload_unmap is set use
9774  * HAT_UNLOAD_UNMAP flag in hat_unload_callback().  If we are the last user of
9775  * svntr free all its anon maps and remove it from the hash table.
9776  */
9777 static void
9778 segvn_textunrepl(struct seg *seg, int unload_unmap)
9779 {
9780 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
9781 	vnode_t			*vp = svd->vp;
9782 	u_offset_t		off = svd->offset;
9783 	size_t			size = seg->s_size;
9784 	u_offset_t		eoff = off + size;
9785 	uint_t			szc = seg->s_szc;
9786 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9787 	svntr_t			*svntrp;
9788 	svntr_t			**prv_svntrp;
9789 	lgrp_id_t		lgrp_id = svd->tr_policy_info.mem_lgrpid;
9790 	lgrp_id_t		i;
9791 
9792 	ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9793 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
9794 	    SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9795 	ASSERT(svd->tr_state == SEGVN_TR_ON);
9796 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9797 	ASSERT(svd->amp != NULL);
9798 	ASSERT(svd->amp->refcnt >= 1);
9799 	ASSERT(svd->anon_index == 0);
9800 	ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9801 	ASSERT(svntr_hashtab != NULL);
9802 
9803 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9804 	prv_svntrp = &svntr_hashtab[hash].tr_head;
9805 	for (; (svntrp = *prv_svntrp) != NULL; prv_svntrp = &svntrp->tr_next) {
9806 		ASSERT(svntrp->tr_refcnt != 0);
9807 		if (svntrp->tr_vp == vp && svntrp->tr_off == off &&
9808 		    svntrp->tr_eoff == eoff && svntrp->tr_szc == szc) {
9809 			break;
9810 		}
9811 	}
9812 	if (svntrp == NULL) {
9813 		panic("segvn_textunrepl: svntr record not found");
9814 	}
9815 	if (svntrp->tr_amp[lgrp_id] != svd->amp) {
9816 		panic("segvn_textunrepl: amp mismatch");
9817 	}
9818 	svd->tr_state = SEGVN_TR_OFF;
9819 	svd->amp = NULL;
9820 	if (svd->svn_trprev == NULL) {
9821 		ASSERT(svntrp->tr_svnhead == svd);
9822 		svntrp->tr_svnhead = svd->svn_trnext;
9823 		if (svntrp->tr_svnhead != NULL) {
9824 			svntrp->tr_svnhead->svn_trprev = NULL;
9825 		}
9826 		svd->svn_trnext = NULL;
9827 	} else {
9828 		svd->svn_trprev->svn_trnext = svd->svn_trnext;
9829 		if (svd->svn_trnext != NULL) {
9830 			svd->svn_trnext->svn_trprev = svd->svn_trprev;
9831 			svd->svn_trnext = NULL;
9832 		}
9833 		svd->svn_trprev = NULL;
9834 	}
9835 	if (--svntrp->tr_refcnt) {
9836 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9837 		goto done;
9838 	}
9839 	*prv_svntrp = svntrp->tr_next;
9840 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9841 	for (i = 0; i < NLGRPS_MAX; i++) {
9842 		struct anon_map *amp = svntrp->tr_amp[i];
9843 		if (amp == NULL) {
9844 			continue;
9845 		}
9846 		ASSERT(amp->refcnt == 1);
9847 		ASSERT(amp->swresv == size);
9848 		ASSERT(amp->size == size);
9849 		ASSERT(amp->a_szc == szc);
9850 		if (amp->a_szc != 0) {
9851 			anon_free_pages(amp->ahp, 0, size, szc);
9852 		} else {
9853 			anon_free(amp->ahp, 0, size);
9854 		}
9855 		svntrp->tr_amp[i] = NULL;
9856 		ASSERT(segvn_textrepl_bytes >= size);
9857 		atomic_add_long(&segvn_textrepl_bytes, -size);
9858 		anon_unresv_zone(amp->swresv, NULL);
9859 		amp->refcnt = 0;
9860 		anonmap_free(amp);
9861 	}
9862 	kmem_cache_free(svntr_cache, svntrp);
9863 done:
9864 	hat_unload_callback(seg->s_as->a_hat, seg->s_base, size,
9865 	    unload_unmap ? HAT_UNLOAD_UNMAP : 0, NULL);
9866 }
9867 
9868 /*
9869  * This is called when a MAP_SHARED writable mapping is created to a vnode
9870  * that is currently used for execution (VVMEXEC flag is set). In this case we
9871  * need to prevent further use of existing replicas.
9872  */
9873 static void
9874 segvn_inval_trcache(vnode_t *vp)
9875 {
9876 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9877 	svntr_t			*svntrp;
9878 
9879 	ASSERT(vp->v_flag & VVMEXEC);
9880 
9881 	if (svntr_hashtab == NULL) {
9882 		return;
9883 	}
9884 
9885 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9886 	svntrp = svntr_hashtab[hash].tr_head;
9887 	for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9888 		ASSERT(svntrp->tr_refcnt != 0);
9889 		if (svntrp->tr_vp == vp && svntrp->tr_valid) {
9890 			svntrp->tr_valid = 0;
9891 		}
9892 	}
9893 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9894 }
9895 
9896 static void
9897 segvn_trasync_thread(void)
9898 {
9899 	callb_cpr_t cpr_info;
9900 	kmutex_t cpr_lock;	/* just for CPR stuff */
9901 
9902 	mutex_init(&cpr_lock, NULL, MUTEX_DEFAULT, NULL);
9903 
9904 	CALLB_CPR_INIT(&cpr_info, &cpr_lock,
9905 	    callb_generic_cpr, "segvn_async");
9906 
9907 	if (segvn_update_textrepl_interval == 0) {
9908 		segvn_update_textrepl_interval = segvn_update_tr_time * hz;
9909 	} else {
9910 		segvn_update_textrepl_interval *= hz;
9911 	}
9912 	(void) timeout(segvn_trupdate_wakeup, NULL,
9913 	    segvn_update_textrepl_interval);
9914 
9915 	for (;;) {
9916 		mutex_enter(&cpr_lock);
9917 		CALLB_CPR_SAFE_BEGIN(&cpr_info);
9918 		mutex_exit(&cpr_lock);
9919 		sema_p(&segvn_trasync_sem);
9920 		mutex_enter(&cpr_lock);
9921 		CALLB_CPR_SAFE_END(&cpr_info, &cpr_lock);
9922 		mutex_exit(&cpr_lock);
9923 		segvn_trupdate();
9924 	}
9925 }
9926 
9927 static uint64_t segvn_lgrp_trthr_migrs_snpsht = 0;
9928 
9929 static void
9930 segvn_trupdate_wakeup(void *dummy)
9931 {
9932 	uint64_t cur_lgrp_trthr_migrs = lgrp_get_trthr_migrations();
9933 
9934 	if (cur_lgrp_trthr_migrs != segvn_lgrp_trthr_migrs_snpsht) {
9935 		segvn_lgrp_trthr_migrs_snpsht = cur_lgrp_trthr_migrs;
9936 		sema_v(&segvn_trasync_sem);
9937 	}
9938 
9939 	if (!segvn_disable_textrepl_update &&
9940 	    segvn_update_textrepl_interval != 0) {
9941 		(void) timeout(segvn_trupdate_wakeup, dummy,
9942 		    segvn_update_textrepl_interval);
9943 	}
9944 }
9945 
9946 static void
9947 segvn_trupdate(void)
9948 {
9949 	ulong_t		hash;
9950 	svntr_t		*svntrp;
9951 	segvn_data_t	*svd;
9952 
9953 	ASSERT(svntr_hashtab != NULL);
9954 
9955 	for (hash = 0; hash < svntr_hashtab_sz; hash++) {
9956 		mutex_enter(&svntr_hashtab[hash].tr_lock);
9957 		svntrp = svntr_hashtab[hash].tr_head;
9958 		for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9959 			ASSERT(svntrp->tr_refcnt != 0);
9960 			svd = svntrp->tr_svnhead;
9961 			for (; svd != NULL; svd = svd->svn_trnext) {
9962 				segvn_trupdate_seg(svd->seg, svd, svntrp,
9963 				    hash);
9964 			}
9965 		}
9966 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9967 	}
9968 }
9969 
9970 static void
9971 segvn_trupdate_seg(struct seg *seg,
9972 	segvn_data_t *svd,
9973 	svntr_t *svntrp,
9974 	ulong_t hash)
9975 {
9976 	proc_t			*p;
9977 	lgrp_id_t		lgrp_id;
9978 	struct as		*as;
9979 	size_t			size;
9980 	struct anon_map		*amp;
9981 
9982 	ASSERT(svd->vp != NULL);
9983 	ASSERT(svd->vp == svntrp->tr_vp);
9984 	ASSERT(svd->offset == svntrp->tr_off);
9985 	ASSERT(svd->offset + seg->s_size == svntrp->tr_eoff);
9986 	ASSERT(seg != NULL);
9987 	ASSERT(svd->seg == seg);
9988 	ASSERT(seg->s_data == (void *)svd);
9989 	ASSERT(seg->s_szc == svntrp->tr_szc);
9990 	ASSERT(svd->tr_state == SEGVN_TR_ON);
9991 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9992 	ASSERT(svd->amp != NULL);
9993 	ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
9994 	ASSERT(svd->tr_policy_info.mem_lgrpid != LGRP_NONE);
9995 	ASSERT(svd->tr_policy_info.mem_lgrpid < NLGRPS_MAX);
9996 	ASSERT(svntrp->tr_amp[svd->tr_policy_info.mem_lgrpid] == svd->amp);
9997 	ASSERT(svntrp->tr_refcnt != 0);
9998 	ASSERT(mutex_owned(&svntr_hashtab[hash].tr_lock));
9999 
10000 	as = seg->s_as;
10001 	ASSERT(as != NULL && as != &kas);
10002 	p = as->a_proc;
10003 	ASSERT(p != NULL);
10004 	ASSERT(p->p_tr_lgrpid != LGRP_NONE);
10005 	lgrp_id = p->p_t1_lgrpid;
10006 	if (lgrp_id == LGRP_NONE) {
10007 		return;
10008 	}
10009 	ASSERT(lgrp_id < NLGRPS_MAX);
10010 	if (svd->tr_policy_info.mem_lgrpid == lgrp_id) {
10011 		return;
10012 	}
10013 
10014 	/*
10015 	 * Use tryenter locking since we are locking as/seg and svntr hash
10016 	 * lock in reverse from syncrounous thread order.
10017 	 */
10018 	if (!AS_LOCK_TRYENTER(as, &as->a_lock, RW_READER)) {
10019 		SEGVN_TR_ADDSTAT(nolock);
10020 		if (segvn_lgrp_trthr_migrs_snpsht) {
10021 			segvn_lgrp_trthr_migrs_snpsht = 0;
10022 		}
10023 		return;
10024 	}
10025 	if (!SEGVN_LOCK_TRYENTER(seg->s_as, &svd->lock, RW_WRITER)) {
10026 		AS_LOCK_EXIT(as, &as->a_lock);
10027 		SEGVN_TR_ADDSTAT(nolock);
10028 		if (segvn_lgrp_trthr_migrs_snpsht) {
10029 			segvn_lgrp_trthr_migrs_snpsht = 0;
10030 		}
10031 		return;
10032 	}
10033 	size = seg->s_size;
10034 	if (svntrp->tr_amp[lgrp_id] == NULL) {
10035 		size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
10036 		if (trmem > segvn_textrepl_max_bytes) {
10037 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10038 			AS_LOCK_EXIT(as, &as->a_lock);
10039 			atomic_add_long(&segvn_textrepl_bytes, -size);
10040 			SEGVN_TR_ADDSTAT(normem);
10041 			return;
10042 		}
10043 		if (anon_try_resv_zone(size, NULL) == 0) {
10044 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10045 			AS_LOCK_EXIT(as, &as->a_lock);
10046 			atomic_add_long(&segvn_textrepl_bytes, -size);
10047 			SEGVN_TR_ADDSTAT(noanon);
10048 			return;
10049 		}
10050 		amp = anonmap_alloc(size, size, KM_NOSLEEP);
10051 		if (amp == NULL) {
10052 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10053 			AS_LOCK_EXIT(as, &as->a_lock);
10054 			atomic_add_long(&segvn_textrepl_bytes, -size);
10055 			anon_unresv_zone(size, NULL);
10056 			SEGVN_TR_ADDSTAT(nokmem);
10057 			return;
10058 		}
10059 		ASSERT(amp->refcnt == 1);
10060 		amp->a_szc = seg->s_szc;
10061 		svntrp->tr_amp[lgrp_id] = amp;
10062 	}
10063 	/*
10064 	 * We don't need to drop the bucket lock but here we give other
10065 	 * threads a chance.  svntr and svd can't be unlinked as long as
10066 	 * segment lock is held as a writer and AS held as well.  After we
10067 	 * retake bucket lock we'll continue from where we left. We'll be able
10068 	 * to reach the end of either list since new entries are always added
10069 	 * to the beginning of the lists.
10070 	 */
10071 	mutex_exit(&svntr_hashtab[hash].tr_lock);
10072 	hat_unload_callback(as->a_hat, seg->s_base, size, 0, NULL);
10073 	mutex_enter(&svntr_hashtab[hash].tr_lock);
10074 
10075 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10076 	ASSERT(svd->amp != NULL);
10077 	ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10078 	ASSERT(svd->tr_policy_info.mem_lgrpid != lgrp_id);
10079 	ASSERT(svd->amp != svntrp->tr_amp[lgrp_id]);
10080 
10081 	svd->tr_policy_info.mem_lgrpid = lgrp_id;
10082 	svd->amp = svntrp->tr_amp[lgrp_id];
10083 	p->p_tr_lgrpid = NLGRPS_MAX;
10084 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10085 	AS_LOCK_EXIT(as, &as->a_lock);
10086 
10087 	ASSERT(svntrp->tr_refcnt != 0);
10088 	ASSERT(svd->vp == svntrp->tr_vp);
10089 	ASSERT(svd->tr_policy_info.mem_lgrpid == lgrp_id);
10090 	ASSERT(svd->amp != NULL && svd->amp == svntrp->tr_amp[lgrp_id]);
10091 	ASSERT(svd->seg == seg);
10092 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10093 
10094 	SEGVN_TR_ADDSTAT(asyncrepl);
10095 }
10096