xref: /titanic_44/usr/src/uts/common/vm/seg_spt.c (revision 48a4016cae8aa2b8b3d8b258eb22e0c781912bed)
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 (c) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2015, Joyent, Inc. All rights reserved.
24  */
25 
26 #include <sys/param.h>
27 #include <sys/user.h>
28 #include <sys/mman.h>
29 #include <sys/kmem.h>
30 #include <sys/sysmacros.h>
31 #include <sys/cmn_err.h>
32 #include <sys/systm.h>
33 #include <sys/tuneable.h>
34 #include <vm/hat.h>
35 #include <vm/seg.h>
36 #include <vm/as.h>
37 #include <vm/anon.h>
38 #include <vm/page.h>
39 #include <sys/buf.h>
40 #include <sys/swap.h>
41 #include <sys/atomic.h>
42 #include <vm/seg_spt.h>
43 #include <sys/debug.h>
44 #include <sys/vtrace.h>
45 #include <sys/shm.h>
46 #include <sys/shm_impl.h>
47 #include <sys/lgrp.h>
48 #include <sys/vmsystm.h>
49 #include <sys/policy.h>
50 #include <sys/project.h>
51 #include <sys/tnf_probe.h>
52 #include <sys/zone.h>
53 
54 #define	SEGSPTADDR	(caddr_t)0x0
55 
56 /*
57  * # pages used for spt
58  */
59 size_t	spt_used;
60 
61 /*
62  * segspt_minfree is the memory left for system after ISM
63  * locked its pages; it is set up to 5% of availrmem in
64  * sptcreate when ISM is created.  ISM should not use more
65  * than ~90% of availrmem; if it does, then the performance
66  * of the system may decrease. Machines with large memories may
67  * be able to use up more memory for ISM so we set the default
68  * segspt_minfree to 5% (which gives ISM max 95% of availrmem.
69  * If somebody wants even more memory for ISM (risking hanging
70  * the system) they can patch the segspt_minfree to smaller number.
71  */
72 pgcnt_t segspt_minfree = 0;
73 
74 static int segspt_create(struct seg *seg, caddr_t argsp);
75 static int segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize);
76 static void segspt_free(struct seg *seg);
77 static void segspt_free_pages(struct seg *seg, caddr_t addr, size_t len);
78 static lgrp_mem_policy_info_t *segspt_getpolicy(struct seg *seg, caddr_t addr);
79 
80 static void
81 segspt_badop()
82 {
83 	panic("segspt_badop called");
84 	/*NOTREACHED*/
85 }
86 
87 #define	SEGSPT_BADOP(t)	(t(*)())segspt_badop
88 
89 struct seg_ops segspt_ops = {
90 	SEGSPT_BADOP(int),		/* dup */
91 	segspt_unmap,
92 	segspt_free,
93 	SEGSPT_BADOP(int),		/* fault */
94 	SEGSPT_BADOP(faultcode_t),	/* faulta */
95 	SEGSPT_BADOP(int),		/* setprot */
96 	SEGSPT_BADOP(int),		/* checkprot */
97 	SEGSPT_BADOP(int),		/* kluster */
98 	SEGSPT_BADOP(size_t),		/* swapout */
99 	SEGSPT_BADOP(int),		/* sync */
100 	SEGSPT_BADOP(size_t),		/* incore */
101 	SEGSPT_BADOP(int),		/* lockop */
102 	SEGSPT_BADOP(int),		/* getprot */
103 	SEGSPT_BADOP(u_offset_t), 	/* getoffset */
104 	SEGSPT_BADOP(int),		/* gettype */
105 	SEGSPT_BADOP(int),		/* getvp */
106 	SEGSPT_BADOP(int),		/* advise */
107 	SEGSPT_BADOP(void),		/* dump */
108 	SEGSPT_BADOP(int),		/* pagelock */
109 	SEGSPT_BADOP(int),		/* setpgsz */
110 	SEGSPT_BADOP(int),		/* getmemid */
111 	segspt_getpolicy,		/* getpolicy */
112 	SEGSPT_BADOP(int),		/* capable */
113 	seg_inherit_notsup		/* inherit */
114 };
115 
116 static int segspt_shmdup(struct seg *seg, struct seg *newseg);
117 static int segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize);
118 static void segspt_shmfree(struct seg *seg);
119 static faultcode_t segspt_shmfault(struct hat *hat, struct seg *seg,
120 		caddr_t addr, size_t len, enum fault_type type, enum seg_rw rw);
121 static faultcode_t segspt_shmfaulta(struct seg *seg, caddr_t addr);
122 static int segspt_shmsetprot(register struct seg *seg, register caddr_t addr,
123 			register size_t len, register uint_t prot);
124 static int segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size,
125 			uint_t prot);
126 static int	segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta);
127 static size_t	segspt_shmswapout(struct seg *seg);
128 static size_t segspt_shmincore(struct seg *seg, caddr_t addr, size_t len,
129 			register char *vec);
130 static int segspt_shmsync(struct seg *seg, register caddr_t addr, size_t len,
131 			int attr, uint_t flags);
132 static int segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
133 			int attr, int op, ulong_t *lockmap, size_t pos);
134 static int segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len,
135 			uint_t *protv);
136 static u_offset_t segspt_shmgetoffset(struct seg *seg, caddr_t addr);
137 static int segspt_shmgettype(struct seg *seg, caddr_t addr);
138 static int segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp);
139 static int segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len,
140 			uint_t behav);
141 static void segspt_shmdump(struct seg *seg);
142 static int segspt_shmpagelock(struct seg *, caddr_t, size_t,
143 			struct page ***, enum lock_type, enum seg_rw);
144 static int segspt_shmsetpgsz(struct seg *, caddr_t, size_t, uint_t);
145 static int segspt_shmgetmemid(struct seg *, caddr_t, memid_t *);
146 static lgrp_mem_policy_info_t *segspt_shmgetpolicy(struct seg *, caddr_t);
147 static int segspt_shmcapable(struct seg *, segcapability_t);
148 
149 struct seg_ops segspt_shmops = {
150 	segspt_shmdup,
151 	segspt_shmunmap,
152 	segspt_shmfree,
153 	segspt_shmfault,
154 	segspt_shmfaulta,
155 	segspt_shmsetprot,
156 	segspt_shmcheckprot,
157 	segspt_shmkluster,
158 	segspt_shmswapout,
159 	segspt_shmsync,
160 	segspt_shmincore,
161 	segspt_shmlockop,
162 	segspt_shmgetprot,
163 	segspt_shmgetoffset,
164 	segspt_shmgettype,
165 	segspt_shmgetvp,
166 	segspt_shmadvise,	/* advise */
167 	segspt_shmdump,
168 	segspt_shmpagelock,
169 	segspt_shmsetpgsz,
170 	segspt_shmgetmemid,
171 	segspt_shmgetpolicy,
172 	segspt_shmcapable,
173 	seg_inherit_notsup
174 };
175 
176 static void segspt_purge(struct seg *seg);
177 static int segspt_reclaim(void *, caddr_t, size_t, struct page **,
178 		enum seg_rw, int);
179 static int spt_anon_getpages(struct seg *seg, caddr_t addr, size_t len,
180 		page_t **ppa);
181 
182 
183 
184 /*ARGSUSED*/
185 int
186 sptcreate(size_t size, struct seg **sptseg, struct anon_map *amp,
187 	uint_t prot, uint_t flags, uint_t share_szc)
188 {
189 	int 	err;
190 	struct  as	*newas;
191 	struct	segspt_crargs sptcargs;
192 
193 #ifdef DEBUG
194 	TNF_PROBE_1(sptcreate, "spt", /* CSTYLED */,
195 			tnf_ulong, size, size );
196 #endif
197 	if (segspt_minfree == 0)	/* leave min 5% of availrmem for */
198 		segspt_minfree = availrmem/20;	/* for the system */
199 
200 	if (!hat_supported(HAT_SHARED_PT, (void *)0))
201 		return (EINVAL);
202 
203 	/*
204 	 * get a new as for this shared memory segment
205 	 */
206 	newas = as_alloc();
207 	newas->a_proc = NULL;
208 	sptcargs.amp = amp;
209 	sptcargs.prot = prot;
210 	sptcargs.flags = flags;
211 	sptcargs.szc = share_szc;
212 	/*
213 	 * create a shared page table (spt) segment
214 	 */
215 
216 	if (err = as_map(newas, SEGSPTADDR, size, segspt_create, &sptcargs)) {
217 		as_free(newas);
218 		return (err);
219 	}
220 	*sptseg = sptcargs.seg_spt;
221 	return (0);
222 }
223 
224 void
225 sptdestroy(struct as *as, struct anon_map *amp)
226 {
227 
228 #ifdef DEBUG
229 	TNF_PROBE_0(sptdestroy, "spt", /* CSTYLED */);
230 #endif
231 	(void) as_unmap(as, SEGSPTADDR, amp->size);
232 	as_free(as);
233 }
234 
235 /*
236  * called from seg_free().
237  * free (i.e., unlock, unmap, return to free list)
238  *  all the pages in the given seg.
239  */
240 void
241 segspt_free(struct seg	*seg)
242 {
243 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
244 
245 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
246 
247 	if (sptd != NULL) {
248 		if (sptd->spt_realsize)
249 			segspt_free_pages(seg, seg->s_base, sptd->spt_realsize);
250 
251 	if (sptd->spt_ppa_lckcnt)
252 		kmem_free(sptd->spt_ppa_lckcnt,
253 		    sizeof (*sptd->spt_ppa_lckcnt)
254 		    * btopr(sptd->spt_amp->size));
255 		kmem_free(sptd->spt_vp, sizeof (*sptd->spt_vp));
256 		cv_destroy(&sptd->spt_cv);
257 		mutex_destroy(&sptd->spt_lock);
258 		kmem_free(sptd, sizeof (*sptd));
259 	}
260 }
261 
262 /*ARGSUSED*/
263 static int
264 segspt_shmsync(struct seg *seg, caddr_t addr, size_t len, int attr,
265 	uint_t flags)
266 {
267 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
268 
269 	return (0);
270 }
271 
272 /*ARGSUSED*/
273 static size_t
274 segspt_shmincore(struct seg *seg, caddr_t addr, size_t len, char *vec)
275 {
276 	caddr_t	eo_seg;
277 	pgcnt_t	npages;
278 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
279 	struct seg	*sptseg;
280 	struct spt_data *sptd;
281 
282 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
283 #ifdef lint
284 	seg = seg;
285 #endif
286 	sptseg = shmd->shm_sptseg;
287 	sptd = sptseg->s_data;
288 
289 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
290 		eo_seg = addr + len;
291 		while (addr < eo_seg) {
292 			/* page exists, and it's locked. */
293 			*vec++ = SEG_PAGE_INCORE | SEG_PAGE_LOCKED |
294 			    SEG_PAGE_ANON;
295 			addr += PAGESIZE;
296 		}
297 		return (len);
298 	} else {
299 		struct  anon_map *amp = shmd->shm_amp;
300 		struct  anon	*ap;
301 		page_t		*pp;
302 		pgcnt_t 	anon_index;
303 		struct vnode 	*vp;
304 		u_offset_t 	off;
305 		ulong_t		i;
306 		int		ret;
307 		anon_sync_obj_t	cookie;
308 
309 		addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
310 		anon_index = seg_page(seg, addr);
311 		npages = btopr(len);
312 		if (anon_index + npages > btopr(shmd->shm_amp->size)) {
313 			return (EINVAL);
314 		}
315 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
316 		for (i = 0; i < npages; i++, anon_index++) {
317 			ret = 0;
318 			anon_array_enter(amp, anon_index, &cookie);
319 			ap = anon_get_ptr(amp->ahp, anon_index);
320 			if (ap != NULL) {
321 				swap_xlate(ap, &vp, &off);
322 				anon_array_exit(&cookie);
323 				pp = page_lookup_nowait(vp, off, SE_SHARED);
324 				if (pp != NULL) {
325 					ret |= SEG_PAGE_INCORE | SEG_PAGE_ANON;
326 					page_unlock(pp);
327 				}
328 			} else {
329 				anon_array_exit(&cookie);
330 			}
331 			if (shmd->shm_vpage[anon_index] & DISM_PG_LOCKED) {
332 				ret |= SEG_PAGE_LOCKED;
333 			}
334 			*vec++ = (char)ret;
335 		}
336 		ANON_LOCK_EXIT(&amp->a_rwlock);
337 		return (len);
338 	}
339 }
340 
341 static int
342 segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize)
343 {
344 	size_t share_size;
345 
346 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
347 
348 	/*
349 	 * seg.s_size may have been rounded up to the largest page size
350 	 * in shmat().
351 	 * XXX This should be cleanedup. sptdestroy should take a length
352 	 * argument which should be the same as sptcreate. Then
353 	 * this rounding would not be needed (or is done in shm.c)
354 	 * Only the check for full segment will be needed.
355 	 *
356 	 * XXX -- shouldn't raddr == 0 always? These tests don't seem
357 	 * to be useful at all.
358 	 */
359 	share_size = page_get_pagesize(seg->s_szc);
360 	ssize = P2ROUNDUP(ssize, share_size);
361 
362 	if (raddr == seg->s_base && ssize == seg->s_size) {
363 		seg_free(seg);
364 		return (0);
365 	} else
366 		return (EINVAL);
367 }
368 
369 int
370 segspt_create(struct seg *seg, caddr_t argsp)
371 {
372 	int		err;
373 	caddr_t		addr = seg->s_base;
374 	struct spt_data *sptd;
375 	struct 	segspt_crargs *sptcargs = (struct segspt_crargs *)argsp;
376 	struct anon_map *amp = sptcargs->amp;
377 	struct kshmid	*sp = amp->a_sp;
378 	struct	cred	*cred = CRED();
379 	ulong_t		i, j, anon_index = 0;
380 	pgcnt_t		npages = btopr(amp->size);
381 	struct vnode	*vp;
382 	page_t		**ppa;
383 	uint_t		hat_flags;
384 	size_t		pgsz;
385 	pgcnt_t		pgcnt;
386 	caddr_t		a;
387 	pgcnt_t		pidx;
388 	size_t		sz;
389 	proc_t		*procp = curproc;
390 	rctl_qty_t	lockedbytes = 0;
391 	kproject_t	*proj;
392 
393 	/*
394 	 * We are holding the a_lock on the underlying dummy as,
395 	 * so we can make calls to the HAT layer.
396 	 */
397 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
398 	ASSERT(sp != NULL);
399 
400 #ifdef DEBUG
401 	TNF_PROBE_2(segspt_create, "spt", /* CSTYLED */,
402 	    tnf_opaque, addr, addr, tnf_ulong, len, seg->s_size);
403 #endif
404 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
405 		if (err = anon_swap_adjust(npages))
406 			return (err);
407 	}
408 	err = ENOMEM;
409 
410 	if ((sptd = kmem_zalloc(sizeof (*sptd), KM_NOSLEEP)) == NULL)
411 		goto out1;
412 
413 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
414 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * npages),
415 		    KM_NOSLEEP)) == NULL)
416 			goto out2;
417 	}
418 
419 	mutex_init(&sptd->spt_lock, NULL, MUTEX_DEFAULT, NULL);
420 
421 	if ((vp = kmem_zalloc(sizeof (*vp), KM_NOSLEEP)) == NULL)
422 		goto out3;
423 
424 	seg->s_ops = &segspt_ops;
425 	sptd->spt_vp = vp;
426 	sptd->spt_amp = amp;
427 	sptd->spt_prot = sptcargs->prot;
428 	sptd->spt_flags = sptcargs->flags;
429 	seg->s_data = (caddr_t)sptd;
430 	sptd->spt_ppa = NULL;
431 	sptd->spt_ppa_lckcnt = NULL;
432 	seg->s_szc = sptcargs->szc;
433 	cv_init(&sptd->spt_cv, NULL, CV_DEFAULT, NULL);
434 	sptd->spt_gen = 0;
435 
436 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
437 	if (seg->s_szc > amp->a_szc) {
438 		amp->a_szc = seg->s_szc;
439 	}
440 	ANON_LOCK_EXIT(&amp->a_rwlock);
441 
442 	/*
443 	 * Set policy to affect initial allocation of pages in
444 	 * anon_map_createpages()
445 	 */
446 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, amp, anon_index,
447 	    NULL, 0, ptob(npages));
448 
449 	if (sptcargs->flags & SHM_PAGEABLE) {
450 		size_t  share_sz;
451 		pgcnt_t new_npgs, more_pgs;
452 		struct anon_hdr *nahp;
453 		zone_t *zone;
454 
455 		share_sz = page_get_pagesize(seg->s_szc);
456 		if (!IS_P2ALIGNED(amp->size, share_sz)) {
457 			/*
458 			 * We are rounding up the size of the anon array
459 			 * on 4 M boundary because we always create 4 M
460 			 * of page(s) when locking, faulting pages and we
461 			 * don't have to check for all corner cases e.g.
462 			 * if there is enough space to allocate 4 M
463 			 * page.
464 			 */
465 			new_npgs = btop(P2ROUNDUP(amp->size, share_sz));
466 			more_pgs = new_npgs - npages;
467 
468 			/*
469 			 * The zone will never be NULL, as a fully created
470 			 * shm always has an owning zone.
471 			 */
472 			zone = sp->shm_perm.ipc_zone_ref.zref_zone;
473 			ASSERT(zone != NULL);
474 			if (anon_resv_zone(ptob(more_pgs), zone) == 0) {
475 				err = ENOMEM;
476 				goto out4;
477 			}
478 
479 			nahp = anon_create(new_npgs, ANON_SLEEP);
480 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
481 			(void) anon_copy_ptr(amp->ahp, 0, nahp, 0, npages,
482 			    ANON_SLEEP);
483 			anon_release(amp->ahp, npages);
484 			amp->ahp = nahp;
485 			ASSERT(amp->swresv == ptob(npages));
486 			amp->swresv = amp->size = ptob(new_npgs);
487 			ANON_LOCK_EXIT(&amp->a_rwlock);
488 			npages = new_npgs;
489 		}
490 
491 		sptd->spt_ppa_lckcnt = kmem_zalloc(npages *
492 		    sizeof (*sptd->spt_ppa_lckcnt), KM_SLEEP);
493 		sptd->spt_pcachecnt = 0;
494 		sptd->spt_realsize = ptob(npages);
495 		sptcargs->seg_spt = seg;
496 		return (0);
497 	}
498 
499 	/*
500 	 * get array of pages for each anon slot in amp
501 	 */
502 	if ((err = anon_map_createpages(amp, anon_index, ptob(npages), ppa,
503 	    seg, addr, S_CREATE, cred)) != 0)
504 		goto out4;
505 
506 	mutex_enter(&sp->shm_mlock);
507 
508 	/* May be partially locked, so, count bytes to charge for locking */
509 	for (i = 0; i < npages; i++)
510 		if (ppa[i]->p_lckcnt == 0)
511 			lockedbytes += PAGESIZE;
512 
513 	proj = sp->shm_perm.ipc_proj;
514 
515 	if (lockedbytes > 0) {
516 		mutex_enter(&procp->p_lock);
517 		if (rctl_incr_locked_mem(procp, proj, lockedbytes, 0)) {
518 			mutex_exit(&procp->p_lock);
519 			mutex_exit(&sp->shm_mlock);
520 			for (i = 0; i < npages; i++)
521 				page_unlock(ppa[i]);
522 			err = ENOMEM;
523 			goto out4;
524 		}
525 		mutex_exit(&procp->p_lock);
526 	}
527 
528 	/*
529 	 * addr is initial address corresponding to the first page on ppa list
530 	 */
531 	for (i = 0; i < npages; i++) {
532 		/* attempt to lock all pages */
533 		if (page_pp_lock(ppa[i], 0, 1) == 0) {
534 			/*
535 			 * if unable to lock any page, unlock all
536 			 * of them and return error
537 			 */
538 			for (j = 0; j < i; j++)
539 				page_pp_unlock(ppa[j], 0, 1);
540 			for (i = 0; i < npages; i++)
541 				page_unlock(ppa[i]);
542 			rctl_decr_locked_mem(NULL, proj, lockedbytes, 0);
543 			mutex_exit(&sp->shm_mlock);
544 			err = ENOMEM;
545 			goto out4;
546 		}
547 	}
548 	mutex_exit(&sp->shm_mlock);
549 
550 	/*
551 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
552 	 * for the entire life of the segment. For example platforms
553 	 * that do not support Dynamic Reconfiguration.
554 	 */
555 	hat_flags = HAT_LOAD_SHARE;
556 	if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, NULL))
557 		hat_flags |= HAT_LOAD_LOCK;
558 
559 	/*
560 	 * Load translations one lare page at a time
561 	 * to make sure we don't create mappings bigger than
562 	 * segment's size code in case underlying pages
563 	 * are shared with segvn's segment that uses bigger
564 	 * size code than we do.
565 	 */
566 	pgsz = page_get_pagesize(seg->s_szc);
567 	pgcnt = page_get_pagecnt(seg->s_szc);
568 	for (a = addr, pidx = 0; pidx < npages; a += pgsz, pidx += pgcnt) {
569 		sz = MIN(pgsz, ptob(npages - pidx));
570 		hat_memload_array(seg->s_as->a_hat, a, sz,
571 		    &ppa[pidx], sptd->spt_prot, hat_flags);
572 	}
573 
574 	/*
575 	 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
576 	 * we will leave the pages locked SE_SHARED for the life
577 	 * of the ISM segment. This will prevent any calls to
578 	 * hat_pageunload() on this ISM segment for those platforms.
579 	 */
580 	if (!(hat_flags & HAT_LOAD_LOCK)) {
581 		/*
582 		 * On platforms that support HAT_DYNAMIC_ISM_UNMAP,
583 		 * we no longer need to hold the SE_SHARED lock on the pages,
584 		 * since L_PAGELOCK and F_SOFTLOCK calls will grab the
585 		 * SE_SHARED lock on the pages as necessary.
586 		 */
587 		for (i = 0; i < npages; i++)
588 			page_unlock(ppa[i]);
589 	}
590 	sptd->spt_pcachecnt = 0;
591 	kmem_free(ppa, ((sizeof (page_t *)) * npages));
592 	sptd->spt_realsize = ptob(npages);
593 	atomic_add_long(&spt_used, npages);
594 	sptcargs->seg_spt = seg;
595 	return (0);
596 
597 out4:
598 	seg->s_data = NULL;
599 	kmem_free(vp, sizeof (*vp));
600 	cv_destroy(&sptd->spt_cv);
601 out3:
602 	mutex_destroy(&sptd->spt_lock);
603 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
604 		kmem_free(ppa, (sizeof (*ppa) * npages));
605 out2:
606 	kmem_free(sptd, sizeof (*sptd));
607 out1:
608 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
609 		anon_swap_restore(npages);
610 	return (err);
611 }
612 
613 /*ARGSUSED*/
614 void
615 segspt_free_pages(struct seg *seg, caddr_t addr, size_t len)
616 {
617 	struct page 	*pp;
618 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
619 	pgcnt_t		npages;
620 	ulong_t		anon_idx;
621 	struct anon_map *amp;
622 	struct anon 	*ap;
623 	struct vnode 	*vp;
624 	u_offset_t 	off;
625 	uint_t		hat_flags;
626 	int		root = 0;
627 	pgcnt_t		pgs, curnpgs = 0;
628 	page_t		*rootpp;
629 	rctl_qty_t	unlocked_bytes = 0;
630 	kproject_t	*proj;
631 	kshmid_t	*sp;
632 
633 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
634 
635 	len = P2ROUNDUP(len, PAGESIZE);
636 
637 	npages = btop(len);
638 
639 	hat_flags = HAT_UNLOAD_UNLOCK | HAT_UNLOAD_UNMAP;
640 	if ((hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) ||
641 	    (sptd->spt_flags & SHM_PAGEABLE)) {
642 		hat_flags = HAT_UNLOAD_UNMAP;
643 	}
644 
645 	hat_unload(seg->s_as->a_hat, addr, len, hat_flags);
646 
647 	amp = sptd->spt_amp;
648 	if (sptd->spt_flags & SHM_PAGEABLE)
649 		npages = btop(amp->size);
650 
651 	ASSERT(amp != NULL);
652 
653 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
654 		sp = amp->a_sp;
655 		proj = sp->shm_perm.ipc_proj;
656 		mutex_enter(&sp->shm_mlock);
657 	}
658 	for (anon_idx = 0; anon_idx < npages; anon_idx++) {
659 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
660 			if ((ap = anon_get_ptr(amp->ahp, anon_idx)) == NULL) {
661 				panic("segspt_free_pages: null app");
662 				/*NOTREACHED*/
663 			}
664 		} else {
665 			if ((ap = anon_get_next_ptr(amp->ahp, &anon_idx))
666 			    == NULL)
667 				continue;
668 		}
669 		ASSERT(ANON_ISBUSY(anon_get_slot(amp->ahp, anon_idx)) == 0);
670 		swap_xlate(ap, &vp, &off);
671 
672 		/*
673 		 * If this platform supports HAT_DYNAMIC_ISM_UNMAP,
674 		 * the pages won't be having SE_SHARED lock at this
675 		 * point.
676 		 *
677 		 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
678 		 * the pages are still held SE_SHARED locked from the
679 		 * original segspt_create()
680 		 *
681 		 * Our goal is to get SE_EXCL lock on each page, remove
682 		 * permanent lock on it and invalidate the page.
683 		 */
684 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
685 			if (hat_flags == HAT_UNLOAD_UNMAP)
686 				pp = page_lookup(vp, off, SE_EXCL);
687 			else {
688 				if ((pp = page_find(vp, off)) == NULL) {
689 					panic("segspt_free_pages: "
690 					    "page not locked");
691 					/*NOTREACHED*/
692 				}
693 				if (!page_tryupgrade(pp)) {
694 					page_unlock(pp);
695 					pp = page_lookup(vp, off, SE_EXCL);
696 				}
697 			}
698 			if (pp == NULL) {
699 				panic("segspt_free_pages: "
700 				    "page not in the system");
701 				/*NOTREACHED*/
702 			}
703 			ASSERT(pp->p_lckcnt > 0);
704 			page_pp_unlock(pp, 0, 1);
705 			if (pp->p_lckcnt == 0)
706 				unlocked_bytes += PAGESIZE;
707 		} else {
708 			if ((pp = page_lookup(vp, off, SE_EXCL)) == NULL)
709 				continue;
710 		}
711 		/*
712 		 * It's logical to invalidate the pages here as in most cases
713 		 * these were created by segspt.
714 		 */
715 		if (pp->p_szc != 0) {
716 			if (root == 0) {
717 				ASSERT(curnpgs == 0);
718 				root = 1;
719 				rootpp = pp;
720 				pgs = curnpgs = page_get_pagecnt(pp->p_szc);
721 				ASSERT(pgs > 1);
722 				ASSERT(IS_P2ALIGNED(pgs, pgs));
723 				ASSERT(!(page_pptonum(pp) & (pgs - 1)));
724 				curnpgs--;
725 			} else if ((page_pptonum(pp) & (pgs - 1)) == pgs - 1) {
726 				ASSERT(curnpgs == 1);
727 				ASSERT(page_pptonum(pp) ==
728 				    page_pptonum(rootpp) + (pgs - 1));
729 				page_destroy_pages(rootpp);
730 				root = 0;
731 				curnpgs = 0;
732 			} else {
733 				ASSERT(curnpgs > 1);
734 				ASSERT(page_pptonum(pp) ==
735 				    page_pptonum(rootpp) + (pgs - curnpgs));
736 				curnpgs--;
737 			}
738 		} else {
739 			if (root != 0 || curnpgs != 0) {
740 				panic("segspt_free_pages: bad large page");
741 				/*NOTREACHED*/
742 			}
743 			/*
744 			 * Before destroying the pages, we need to take care
745 			 * of the rctl locked memory accounting. For that
746 			 * we need to calculte the unlocked_bytes.
747 			 */
748 			if (pp->p_lckcnt > 0)
749 				unlocked_bytes += PAGESIZE;
750 			/*LINTED: constant in conditional context */
751 			VN_DISPOSE(pp, B_INVAL, 0, kcred);
752 		}
753 	}
754 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
755 		if (unlocked_bytes > 0)
756 			rctl_decr_locked_mem(NULL, proj, unlocked_bytes, 0);
757 		mutex_exit(&sp->shm_mlock);
758 	}
759 	if (root != 0 || curnpgs != 0) {
760 		panic("segspt_free_pages: bad large page");
761 		/*NOTREACHED*/
762 	}
763 
764 	/*
765 	 * mark that pages have been released
766 	 */
767 	sptd->spt_realsize = 0;
768 
769 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
770 		atomic_add_long(&spt_used, -npages);
771 		anon_swap_restore(npages);
772 	}
773 }
774 
775 /*
776  * Get memory allocation policy info for specified address in given segment
777  */
778 static lgrp_mem_policy_info_t *
779 segspt_getpolicy(struct seg *seg, caddr_t addr)
780 {
781 	struct anon_map		*amp;
782 	ulong_t			anon_index;
783 	lgrp_mem_policy_info_t	*policy_info;
784 	struct spt_data		*spt_data;
785 
786 	ASSERT(seg != NULL);
787 
788 	/*
789 	 * Get anon_map from segspt
790 	 *
791 	 * Assume that no lock needs to be held on anon_map, since
792 	 * it should be protected by its reference count which must be
793 	 * nonzero for an existing segment
794 	 * Need to grab readers lock on policy tree though
795 	 */
796 	spt_data = (struct spt_data *)seg->s_data;
797 	if (spt_data == NULL)
798 		return (NULL);
799 	amp = spt_data->spt_amp;
800 	ASSERT(amp->refcnt != 0);
801 
802 	/*
803 	 * Get policy info
804 	 *
805 	 * Assume starting anon index of 0
806 	 */
807 	anon_index = seg_page(seg, addr);
808 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
809 
810 	return (policy_info);
811 }
812 
813 /*
814  * DISM only.
815  * Return locked pages over a given range.
816  *
817  * We will cache all DISM locked pages and save the pplist for the
818  * entire segment in the ppa field of the underlying DISM segment structure.
819  * Later, during a call to segspt_reclaim() we will use this ppa array
820  * to page_unlock() all of the pages and then we will free this ppa list.
821  */
822 /*ARGSUSED*/
823 static int
824 segspt_dismpagelock(struct seg *seg, caddr_t addr, size_t len,
825     struct page ***ppp, enum lock_type type, enum seg_rw rw)
826 {
827 	struct  shm_data *shmd = (struct shm_data *)seg->s_data;
828 	struct  seg	*sptseg = shmd->shm_sptseg;
829 	struct  spt_data *sptd = sptseg->s_data;
830 	pgcnt_t pg_idx, npages, tot_npages, npgs;
831 	struct  page **pplist, **pl, **ppa, *pp;
832 	struct  anon_map *amp;
833 	spgcnt_t	an_idx;
834 	int 	ret = ENOTSUP;
835 	uint_t	pl_built = 0;
836 	struct  anon *ap;
837 	struct  vnode *vp;
838 	u_offset_t off;
839 	pgcnt_t claim_availrmem = 0;
840 	uint_t	szc;
841 
842 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
843 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
844 
845 	/*
846 	 * We want to lock/unlock the entire ISM segment. Therefore,
847 	 * we will be using the underlying sptseg and it's base address
848 	 * and length for the caching arguments.
849 	 */
850 	ASSERT(sptseg);
851 	ASSERT(sptd);
852 
853 	pg_idx = seg_page(seg, addr);
854 	npages = btopr(len);
855 
856 	/*
857 	 * check if the request is larger than number of pages covered
858 	 * by amp
859 	 */
860 	if (pg_idx + npages > btopr(sptd->spt_amp->size)) {
861 		*ppp = NULL;
862 		return (ENOTSUP);
863 	}
864 
865 	if (type == L_PAGEUNLOCK) {
866 		ASSERT(sptd->spt_ppa != NULL);
867 
868 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
869 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
870 
871 		/*
872 		 * If someone is blocked while unmapping, we purge
873 		 * segment page cache and thus reclaim pplist synchronously
874 		 * without waiting for seg_pasync_thread. This speeds up
875 		 * unmapping in cases where munmap(2) is called, while
876 		 * raw async i/o is still in progress or where a thread
877 		 * exits on data fault in a multithreaded application.
878 		 */
879 		if ((sptd->spt_flags & DISM_PPA_CHANGED) ||
880 		    (AS_ISUNMAPWAIT(seg->s_as) &&
881 		    shmd->shm_softlockcnt > 0)) {
882 			segspt_purge(seg);
883 		}
884 		return (0);
885 	}
886 
887 	/* The L_PAGELOCK case ... */
888 
889 	if (sptd->spt_flags & DISM_PPA_CHANGED) {
890 		segspt_purge(seg);
891 		/*
892 		 * for DISM ppa needs to be rebuild since
893 		 * number of locked pages could be changed
894 		 */
895 		*ppp = NULL;
896 		return (ENOTSUP);
897 	}
898 
899 	/*
900 	 * First try to find pages in segment page cache, without
901 	 * holding the segment lock.
902 	 */
903 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
904 	    S_WRITE, SEGP_FORCE_WIRED);
905 	if (pplist != NULL) {
906 		ASSERT(sptd->spt_ppa != NULL);
907 		ASSERT(sptd->spt_ppa == pplist);
908 		ppa = sptd->spt_ppa;
909 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
910 			if (ppa[an_idx] == NULL) {
911 				seg_pinactive(seg, NULL, seg->s_base,
912 				    sptd->spt_amp->size, ppa,
913 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
914 				*ppp = NULL;
915 				return (ENOTSUP);
916 			}
917 			if ((szc = ppa[an_idx]->p_szc) != 0) {
918 				npgs = page_get_pagecnt(szc);
919 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
920 			} else {
921 				an_idx++;
922 			}
923 		}
924 		/*
925 		 * Since we cache the entire DISM segment, we want to
926 		 * set ppp to point to the first slot that corresponds
927 		 * to the requested addr, i.e. pg_idx.
928 		 */
929 		*ppp = &(sptd->spt_ppa[pg_idx]);
930 		return (0);
931 	}
932 
933 	mutex_enter(&sptd->spt_lock);
934 	/*
935 	 * try to find pages in segment page cache with mutex
936 	 */
937 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
938 	    S_WRITE, SEGP_FORCE_WIRED);
939 	if (pplist != NULL) {
940 		ASSERT(sptd->spt_ppa != NULL);
941 		ASSERT(sptd->spt_ppa == pplist);
942 		ppa = sptd->spt_ppa;
943 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
944 			if (ppa[an_idx] == NULL) {
945 				mutex_exit(&sptd->spt_lock);
946 				seg_pinactive(seg, NULL, seg->s_base,
947 				    sptd->spt_amp->size, ppa,
948 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
949 				*ppp = NULL;
950 				return (ENOTSUP);
951 			}
952 			if ((szc = ppa[an_idx]->p_szc) != 0) {
953 				npgs = page_get_pagecnt(szc);
954 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
955 			} else {
956 				an_idx++;
957 			}
958 		}
959 		/*
960 		 * Since we cache the entire DISM segment, we want to
961 		 * set ppp to point to the first slot that corresponds
962 		 * to the requested addr, i.e. pg_idx.
963 		 */
964 		mutex_exit(&sptd->spt_lock);
965 		*ppp = &(sptd->spt_ppa[pg_idx]);
966 		return (0);
967 	}
968 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
969 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
970 		mutex_exit(&sptd->spt_lock);
971 		*ppp = NULL;
972 		return (ENOTSUP);
973 	}
974 
975 	/*
976 	 * No need to worry about protections because DISM pages are always rw.
977 	 */
978 	pl = pplist = NULL;
979 	amp = sptd->spt_amp;
980 
981 	/*
982 	 * Do we need to build the ppa array?
983 	 */
984 	if (sptd->spt_ppa == NULL) {
985 		pgcnt_t lpg_cnt = 0;
986 
987 		pl_built = 1;
988 		tot_npages = btopr(sptd->spt_amp->size);
989 
990 		ASSERT(sptd->spt_pcachecnt == 0);
991 		pplist = kmem_zalloc(sizeof (page_t *) * tot_npages, KM_SLEEP);
992 		pl = pplist;
993 
994 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
995 		for (an_idx = 0; an_idx < tot_npages; ) {
996 			ap = anon_get_ptr(amp->ahp, an_idx);
997 			/*
998 			 * Cache only mlocked pages. For large pages
999 			 * if one (constituent) page is mlocked
1000 			 * all pages for that large page
1001 			 * are cached also. This is for quick
1002 			 * lookups of ppa array;
1003 			 */
1004 			if ((ap != NULL) && (lpg_cnt != 0 ||
1005 			    (sptd->spt_ppa_lckcnt[an_idx] != 0))) {
1006 
1007 				swap_xlate(ap, &vp, &off);
1008 				pp = page_lookup(vp, off, SE_SHARED);
1009 				ASSERT(pp != NULL);
1010 				if (lpg_cnt == 0) {
1011 					lpg_cnt++;
1012 					/*
1013 					 * For a small page, we are done --
1014 					 * lpg_count is reset to 0 below.
1015 					 *
1016 					 * For a large page, we are guaranteed
1017 					 * to find the anon structures of all
1018 					 * constituent pages and a non-zero
1019 					 * lpg_cnt ensures that we don't test
1020 					 * for mlock for these. We are done
1021 					 * when lpg_count reaches (npgs + 1).
1022 					 * If we are not the first constituent
1023 					 * page, restart at the first one.
1024 					 */
1025 					npgs = page_get_pagecnt(pp->p_szc);
1026 					if (!IS_P2ALIGNED(an_idx, npgs)) {
1027 						an_idx = P2ALIGN(an_idx, npgs);
1028 						page_unlock(pp);
1029 						continue;
1030 					}
1031 				}
1032 				if (++lpg_cnt > npgs)
1033 					lpg_cnt = 0;
1034 
1035 				/*
1036 				 * availrmem is decremented only
1037 				 * for unlocked pages
1038 				 */
1039 				if (sptd->spt_ppa_lckcnt[an_idx] == 0)
1040 					claim_availrmem++;
1041 				pplist[an_idx] = pp;
1042 			}
1043 			an_idx++;
1044 		}
1045 		ANON_LOCK_EXIT(&amp->a_rwlock);
1046 
1047 		if (claim_availrmem) {
1048 			mutex_enter(&freemem_lock);
1049 			if (availrmem < tune.t_minarmem + claim_availrmem) {
1050 				mutex_exit(&freemem_lock);
1051 				ret = ENOTSUP;
1052 				claim_availrmem = 0;
1053 				goto insert_fail;
1054 			} else {
1055 				availrmem -= claim_availrmem;
1056 			}
1057 			mutex_exit(&freemem_lock);
1058 		}
1059 
1060 		sptd->spt_ppa = pl;
1061 	} else {
1062 		/*
1063 		 * We already have a valid ppa[].
1064 		 */
1065 		pl = sptd->spt_ppa;
1066 	}
1067 
1068 	ASSERT(pl != NULL);
1069 
1070 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1071 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1072 	    segspt_reclaim);
1073 	if (ret == SEGP_FAIL) {
1074 		/*
1075 		 * seg_pinsert failed. We return
1076 		 * ENOTSUP, so that the as_pagelock() code will
1077 		 * then try the slower F_SOFTLOCK path.
1078 		 */
1079 		if (pl_built) {
1080 			/*
1081 			 * No one else has referenced the ppa[].
1082 			 * We created it and we need to destroy it.
1083 			 */
1084 			sptd->spt_ppa = NULL;
1085 		}
1086 		ret = ENOTSUP;
1087 		goto insert_fail;
1088 	}
1089 
1090 	/*
1091 	 * In either case, we increment softlockcnt on the 'real' segment.
1092 	 */
1093 	sptd->spt_pcachecnt++;
1094 	atomic_inc_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
1095 
1096 	ppa = sptd->spt_ppa;
1097 	for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
1098 		if (ppa[an_idx] == NULL) {
1099 			mutex_exit(&sptd->spt_lock);
1100 			seg_pinactive(seg, NULL, seg->s_base,
1101 			    sptd->spt_amp->size,
1102 			    pl, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1103 			*ppp = NULL;
1104 			return (ENOTSUP);
1105 		}
1106 		if ((szc = ppa[an_idx]->p_szc) != 0) {
1107 			npgs = page_get_pagecnt(szc);
1108 			an_idx = P2ROUNDUP(an_idx + 1, npgs);
1109 		} else {
1110 			an_idx++;
1111 		}
1112 	}
1113 	/*
1114 	 * We can now drop the sptd->spt_lock since the ppa[]
1115 	 * exists and he have incremented pacachecnt.
1116 	 */
1117 	mutex_exit(&sptd->spt_lock);
1118 
1119 	/*
1120 	 * Since we cache the entire segment, we want to
1121 	 * set ppp to point to the first slot that corresponds
1122 	 * to the requested addr, i.e. pg_idx.
1123 	 */
1124 	*ppp = &(sptd->spt_ppa[pg_idx]);
1125 	return (0);
1126 
1127 insert_fail:
1128 	/*
1129 	 * We will only reach this code if we tried and failed.
1130 	 *
1131 	 * And we can drop the lock on the dummy seg, once we've failed
1132 	 * to set up a new ppa[].
1133 	 */
1134 	mutex_exit(&sptd->spt_lock);
1135 
1136 	if (pl_built) {
1137 		if (claim_availrmem) {
1138 			mutex_enter(&freemem_lock);
1139 			availrmem += claim_availrmem;
1140 			mutex_exit(&freemem_lock);
1141 		}
1142 
1143 		/*
1144 		 * We created pl and we need to destroy it.
1145 		 */
1146 		pplist = pl;
1147 		for (an_idx = 0; an_idx < tot_npages; an_idx++) {
1148 			if (pplist[an_idx] != NULL)
1149 				page_unlock(pplist[an_idx]);
1150 		}
1151 		kmem_free(pl, sizeof (page_t *) * tot_npages);
1152 	}
1153 
1154 	if (shmd->shm_softlockcnt <= 0) {
1155 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1156 			mutex_enter(&seg->s_as->a_contents);
1157 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1158 				AS_CLRUNMAPWAIT(seg->s_as);
1159 				cv_broadcast(&seg->s_as->a_cv);
1160 			}
1161 			mutex_exit(&seg->s_as->a_contents);
1162 		}
1163 	}
1164 	*ppp = NULL;
1165 	return (ret);
1166 }
1167 
1168 
1169 
1170 /*
1171  * return locked pages over a given range.
1172  *
1173  * We will cache the entire ISM segment and save the pplist for the
1174  * entire segment in the ppa field of the underlying ISM segment structure.
1175  * Later, during a call to segspt_reclaim() we will use this ppa array
1176  * to page_unlock() all of the pages and then we will free this ppa list.
1177  */
1178 /*ARGSUSED*/
1179 static int
1180 segspt_shmpagelock(struct seg *seg, caddr_t addr, size_t len,
1181     struct page ***ppp, enum lock_type type, enum seg_rw rw)
1182 {
1183 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1184 	struct seg	*sptseg = shmd->shm_sptseg;
1185 	struct spt_data *sptd = sptseg->s_data;
1186 	pgcnt_t np, page_index, npages;
1187 	caddr_t a, spt_base;
1188 	struct page **pplist, **pl, *pp;
1189 	struct anon_map *amp;
1190 	ulong_t anon_index;
1191 	int ret = ENOTSUP;
1192 	uint_t	pl_built = 0;
1193 	struct anon *ap;
1194 	struct vnode *vp;
1195 	u_offset_t off;
1196 
1197 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1198 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
1199 
1200 
1201 	/*
1202 	 * We want to lock/unlock the entire ISM segment. Therefore,
1203 	 * we will be using the underlying sptseg and it's base address
1204 	 * and length for the caching arguments.
1205 	 */
1206 	ASSERT(sptseg);
1207 	ASSERT(sptd);
1208 
1209 	if (sptd->spt_flags & SHM_PAGEABLE) {
1210 		return (segspt_dismpagelock(seg, addr, len, ppp, type, rw));
1211 	}
1212 
1213 	page_index = seg_page(seg, addr);
1214 	npages = btopr(len);
1215 
1216 	/*
1217 	 * check if the request is larger than number of pages covered
1218 	 * by amp
1219 	 */
1220 	if (page_index + npages > btopr(sptd->spt_amp->size)) {
1221 		*ppp = NULL;
1222 		return (ENOTSUP);
1223 	}
1224 
1225 	if (type == L_PAGEUNLOCK) {
1226 
1227 		ASSERT(sptd->spt_ppa != NULL);
1228 
1229 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
1230 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1231 
1232 		/*
1233 		 * If someone is blocked while unmapping, we purge
1234 		 * segment page cache and thus reclaim pplist synchronously
1235 		 * without waiting for seg_pasync_thread. This speeds up
1236 		 * unmapping in cases where munmap(2) is called, while
1237 		 * raw async i/o is still in progress or where a thread
1238 		 * exits on data fault in a multithreaded application.
1239 		 */
1240 		if (AS_ISUNMAPWAIT(seg->s_as) && (shmd->shm_softlockcnt > 0)) {
1241 			segspt_purge(seg);
1242 		}
1243 		return (0);
1244 	}
1245 
1246 	/* The L_PAGELOCK case... */
1247 
1248 	/*
1249 	 * First try to find pages in segment page cache, without
1250 	 * holding the segment lock.
1251 	 */
1252 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1253 	    S_WRITE, SEGP_FORCE_WIRED);
1254 	if (pplist != NULL) {
1255 		ASSERT(sptd->spt_ppa == pplist);
1256 		ASSERT(sptd->spt_ppa[page_index]);
1257 		/*
1258 		 * Since we cache the entire ISM segment, we want to
1259 		 * set ppp to point to the first slot that corresponds
1260 		 * to the requested addr, i.e. page_index.
1261 		 */
1262 		*ppp = &(sptd->spt_ppa[page_index]);
1263 		return (0);
1264 	}
1265 
1266 	mutex_enter(&sptd->spt_lock);
1267 
1268 	/*
1269 	 * try to find pages in segment page cache
1270 	 */
1271 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1272 	    S_WRITE, SEGP_FORCE_WIRED);
1273 	if (pplist != NULL) {
1274 		ASSERT(sptd->spt_ppa == pplist);
1275 		/*
1276 		 * Since we cache the entire segment, we want to
1277 		 * set ppp to point to the first slot that corresponds
1278 		 * to the requested addr, i.e. page_index.
1279 		 */
1280 		mutex_exit(&sptd->spt_lock);
1281 		*ppp = &(sptd->spt_ppa[page_index]);
1282 		return (0);
1283 	}
1284 
1285 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
1286 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
1287 		mutex_exit(&sptd->spt_lock);
1288 		*ppp = NULL;
1289 		return (ENOTSUP);
1290 	}
1291 
1292 	/*
1293 	 * No need to worry about protections because ISM pages
1294 	 * are always rw.
1295 	 */
1296 	pl = pplist = NULL;
1297 
1298 	/*
1299 	 * Do we need to build the ppa array?
1300 	 */
1301 	if (sptd->spt_ppa == NULL) {
1302 		ASSERT(sptd->spt_ppa == pplist);
1303 
1304 		spt_base = sptseg->s_base;
1305 		pl_built = 1;
1306 
1307 		/*
1308 		 * availrmem is decremented once during anon_swap_adjust()
1309 		 * and is incremented during the anon_unresv(), which is
1310 		 * called from shm_rm_amp() when the segment is destroyed.
1311 		 */
1312 		amp = sptd->spt_amp;
1313 		ASSERT(amp != NULL);
1314 
1315 		/* pcachecnt is protected by sptd->spt_lock */
1316 		ASSERT(sptd->spt_pcachecnt == 0);
1317 		pplist = kmem_zalloc(sizeof (page_t *)
1318 		    * btopr(sptd->spt_amp->size), KM_SLEEP);
1319 		pl = pplist;
1320 
1321 		anon_index = seg_page(sptseg, spt_base);
1322 
1323 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1324 		for (a = spt_base; a < (spt_base + sptd->spt_amp->size);
1325 		    a += PAGESIZE, anon_index++, pplist++) {
1326 			ap = anon_get_ptr(amp->ahp, anon_index);
1327 			ASSERT(ap != NULL);
1328 			swap_xlate(ap, &vp, &off);
1329 			pp = page_lookup(vp, off, SE_SHARED);
1330 			ASSERT(pp != NULL);
1331 			*pplist = pp;
1332 		}
1333 		ANON_LOCK_EXIT(&amp->a_rwlock);
1334 
1335 		if (a < (spt_base + sptd->spt_amp->size)) {
1336 			ret = ENOTSUP;
1337 			goto insert_fail;
1338 		}
1339 		sptd->spt_ppa = pl;
1340 	} else {
1341 		/*
1342 		 * We already have a valid ppa[].
1343 		 */
1344 		pl = sptd->spt_ppa;
1345 	}
1346 
1347 	ASSERT(pl != NULL);
1348 
1349 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1350 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1351 	    segspt_reclaim);
1352 	if (ret == SEGP_FAIL) {
1353 		/*
1354 		 * seg_pinsert failed. We return
1355 		 * ENOTSUP, so that the as_pagelock() code will
1356 		 * then try the slower F_SOFTLOCK path.
1357 		 */
1358 		if (pl_built) {
1359 			/*
1360 			 * No one else has referenced the ppa[].
1361 			 * We created it and we need to destroy it.
1362 			 */
1363 			sptd->spt_ppa = NULL;
1364 		}
1365 		ret = ENOTSUP;
1366 		goto insert_fail;
1367 	}
1368 
1369 	/*
1370 	 * In either case, we increment softlockcnt on the 'real' segment.
1371 	 */
1372 	sptd->spt_pcachecnt++;
1373 	atomic_inc_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
1374 
1375 	/*
1376 	 * We can now drop the sptd->spt_lock since the ppa[]
1377 	 * exists and he have incremented pacachecnt.
1378 	 */
1379 	mutex_exit(&sptd->spt_lock);
1380 
1381 	/*
1382 	 * Since we cache the entire segment, we want to
1383 	 * set ppp to point to the first slot that corresponds
1384 	 * to the requested addr, i.e. page_index.
1385 	 */
1386 	*ppp = &(sptd->spt_ppa[page_index]);
1387 	return (0);
1388 
1389 insert_fail:
1390 	/*
1391 	 * We will only reach this code if we tried and failed.
1392 	 *
1393 	 * And we can drop the lock on the dummy seg, once we've failed
1394 	 * to set up a new ppa[].
1395 	 */
1396 	mutex_exit(&sptd->spt_lock);
1397 
1398 	if (pl_built) {
1399 		/*
1400 		 * We created pl and we need to destroy it.
1401 		 */
1402 		pplist = pl;
1403 		np = (((uintptr_t)(a - spt_base)) >> PAGESHIFT);
1404 		while (np) {
1405 			page_unlock(*pplist);
1406 			np--;
1407 			pplist++;
1408 		}
1409 		kmem_free(pl, sizeof (page_t *) * btopr(sptd->spt_amp->size));
1410 	}
1411 	if (shmd->shm_softlockcnt <= 0) {
1412 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1413 			mutex_enter(&seg->s_as->a_contents);
1414 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1415 				AS_CLRUNMAPWAIT(seg->s_as);
1416 				cv_broadcast(&seg->s_as->a_cv);
1417 			}
1418 			mutex_exit(&seg->s_as->a_contents);
1419 		}
1420 	}
1421 	*ppp = NULL;
1422 	return (ret);
1423 }
1424 
1425 /*
1426  * purge any cached pages in the I/O page cache
1427  */
1428 static void
1429 segspt_purge(struct seg *seg)
1430 {
1431 	seg_ppurge(seg, NULL, SEGP_FORCE_WIRED);
1432 }
1433 
1434 static int
1435 segspt_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
1436 	enum seg_rw rw, int async)
1437 {
1438 	struct seg *seg = (struct seg *)ptag;
1439 	struct	shm_data *shmd = (struct shm_data *)seg->s_data;
1440 	struct	seg	*sptseg;
1441 	struct	spt_data *sptd;
1442 	pgcnt_t npages, i, free_availrmem = 0;
1443 	int	done = 0;
1444 
1445 #ifdef lint
1446 	addr = addr;
1447 #endif
1448 	sptseg = shmd->shm_sptseg;
1449 	sptd = sptseg->s_data;
1450 	npages = (len >> PAGESHIFT);
1451 	ASSERT(npages);
1452 	ASSERT(sptd->spt_pcachecnt != 0);
1453 	ASSERT(sptd->spt_ppa == pplist);
1454 	ASSERT(npages == btopr(sptd->spt_amp->size));
1455 	ASSERT(async || AS_LOCK_HELD(seg->s_as));
1456 
1457 	/*
1458 	 * Acquire the lock on the dummy seg and destroy the
1459 	 * ppa array IF this is the last pcachecnt.
1460 	 */
1461 	mutex_enter(&sptd->spt_lock);
1462 	if (--sptd->spt_pcachecnt == 0) {
1463 		for (i = 0; i < npages; i++) {
1464 			if (pplist[i] == NULL) {
1465 				continue;
1466 			}
1467 			if (rw == S_WRITE) {
1468 				hat_setrefmod(pplist[i]);
1469 			} else {
1470 				hat_setref(pplist[i]);
1471 			}
1472 			if ((sptd->spt_flags & SHM_PAGEABLE) &&
1473 			    (sptd->spt_ppa_lckcnt[i] == 0))
1474 				free_availrmem++;
1475 			page_unlock(pplist[i]);
1476 		}
1477 		if ((sptd->spt_flags & SHM_PAGEABLE) && free_availrmem) {
1478 			mutex_enter(&freemem_lock);
1479 			availrmem += free_availrmem;
1480 			mutex_exit(&freemem_lock);
1481 		}
1482 		/*
1483 		 * Since we want to cach/uncache the entire ISM segment,
1484 		 * we will track the pplist in a segspt specific field
1485 		 * ppa, that is initialized at the time we add an entry to
1486 		 * the cache.
1487 		 */
1488 		ASSERT(sptd->spt_pcachecnt == 0);
1489 		kmem_free(pplist, sizeof (page_t *) * npages);
1490 		sptd->spt_ppa = NULL;
1491 		sptd->spt_flags &= ~DISM_PPA_CHANGED;
1492 		sptd->spt_gen++;
1493 		cv_broadcast(&sptd->spt_cv);
1494 		done = 1;
1495 	}
1496 	mutex_exit(&sptd->spt_lock);
1497 
1498 	/*
1499 	 * If we are pcache async thread or called via seg_ppurge_wiredpp() we
1500 	 * may not hold AS lock (in this case async argument is not 0). This
1501 	 * means if softlockcnt drops to 0 after the decrement below address
1502 	 * space may get freed. We can't allow it since after softlock
1503 	 * derement to 0 we still need to access as structure for possible
1504 	 * wakeup of unmap waiters. To prevent the disappearance of as we take
1505 	 * this segment's shm_segfree_syncmtx. segspt_shmfree() also takes
1506 	 * this mutex as a barrier to make sure this routine completes before
1507 	 * segment is freed.
1508 	 *
1509 	 * The second complication we have to deal with in async case is a
1510 	 * possibility of missed wake up of unmap wait thread. When we don't
1511 	 * hold as lock here we may take a_contents lock before unmap wait
1512 	 * thread that was first to see softlockcnt was still not 0. As a
1513 	 * result we'll fail to wake up an unmap wait thread. To avoid this
1514 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
1515 	 * to 0 if async is not 0.  unmapwait thread
1516 	 * will not block if this flag is set.
1517 	 */
1518 	if (async)
1519 		mutex_enter(&shmd->shm_segfree_syncmtx);
1520 
1521 	/*
1522 	 * Now decrement softlockcnt.
1523 	 */
1524 	ASSERT(shmd->shm_softlockcnt > 0);
1525 	atomic_dec_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
1526 
1527 	if (shmd->shm_softlockcnt <= 0) {
1528 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
1529 			mutex_enter(&seg->s_as->a_contents);
1530 			if (async)
1531 				AS_SETNOUNMAPWAIT(seg->s_as);
1532 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1533 				AS_CLRUNMAPWAIT(seg->s_as);
1534 				cv_broadcast(&seg->s_as->a_cv);
1535 			}
1536 			mutex_exit(&seg->s_as->a_contents);
1537 		}
1538 	}
1539 
1540 	if (async)
1541 		mutex_exit(&shmd->shm_segfree_syncmtx);
1542 
1543 	return (done);
1544 }
1545 
1546 /*
1547  * Do a F_SOFTUNLOCK call over the range requested.
1548  * The range must have already been F_SOFTLOCK'ed.
1549  *
1550  * The calls to acquire and release the anon map lock mutex were
1551  * removed in order to avoid a deadly embrace during a DR
1552  * memory delete operation.  (Eg. DR blocks while waiting for a
1553  * exclusive lock on a page that is being used for kaio; the
1554  * thread that will complete the kaio and call segspt_softunlock
1555  * blocks on the anon map lock; another thread holding the anon
1556  * map lock blocks on another page lock via the segspt_shmfault
1557  * -> page_lookup -> page_lookup_create -> page_lock_es code flow.)
1558  *
1559  * The appropriateness of the removal is based upon the following:
1560  * 1. If we are holding a segment's reader lock and the page is held
1561  * shared, then the corresponding element in anonmap which points to
1562  * anon struct cannot change and there is no need to acquire the
1563  * anonymous map lock.
1564  * 2. Threads in segspt_softunlock have a reader lock on the segment
1565  * and already have the shared page lock, so we are guaranteed that
1566  * the anon map slot cannot change and therefore can call anon_get_ptr()
1567  * without grabbing the anonymous map lock.
1568  * 3. Threads that softlock a shared page break copy-on-write, even if
1569  * its a read.  Thus cow faults can be ignored with respect to soft
1570  * unlocking, since the breaking of cow means that the anon slot(s) will
1571  * not be shared.
1572  */
1573 static void
1574 segspt_softunlock(struct seg *seg, caddr_t sptseg_addr,
1575 	size_t len, enum seg_rw rw)
1576 {
1577 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1578 	struct seg	*sptseg;
1579 	struct spt_data *sptd;
1580 	page_t *pp;
1581 	caddr_t adr;
1582 	struct vnode *vp;
1583 	u_offset_t offset;
1584 	ulong_t anon_index;
1585 	struct anon_map *amp;		/* XXX - for locknest */
1586 	struct anon *ap = NULL;
1587 	pgcnt_t npages;
1588 
1589 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1590 
1591 	sptseg = shmd->shm_sptseg;
1592 	sptd = sptseg->s_data;
1593 
1594 	/*
1595 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
1596 	 * and therefore their pages are SE_SHARED locked
1597 	 * for the entire life of the segment.
1598 	 */
1599 	if ((!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) &&
1600 	    ((sptd->spt_flags & SHM_PAGEABLE) == 0)) {
1601 		goto softlock_decrement;
1602 	}
1603 
1604 	/*
1605 	 * Any thread is free to do a page_find and
1606 	 * page_unlock() on the pages within this seg.
1607 	 *
1608 	 * We are already holding the as->a_lock on the user's
1609 	 * real segment, but we need to hold the a_lock on the
1610 	 * underlying dummy as. This is mostly to satisfy the
1611 	 * underlying HAT layer.
1612 	 */
1613 	AS_LOCK_ENTER(sptseg->s_as, RW_READER);
1614 	hat_unlock(sptseg->s_as->a_hat, sptseg_addr, len);
1615 	AS_LOCK_EXIT(sptseg->s_as);
1616 
1617 	amp = sptd->spt_amp;
1618 	ASSERT(amp != NULL);
1619 	anon_index = seg_page(sptseg, sptseg_addr);
1620 
1621 	for (adr = sptseg_addr; adr < sptseg_addr + len; adr += PAGESIZE) {
1622 		ap = anon_get_ptr(amp->ahp, anon_index++);
1623 		ASSERT(ap != NULL);
1624 		swap_xlate(ap, &vp, &offset);
1625 
1626 		/*
1627 		 * Use page_find() instead of page_lookup() to
1628 		 * find the page since we know that it has a
1629 		 * "shared" lock.
1630 		 */
1631 		pp = page_find(vp, offset);
1632 		ASSERT(ap == anon_get_ptr(amp->ahp, anon_index - 1));
1633 		if (pp == NULL) {
1634 			panic("segspt_softunlock: "
1635 			    "addr %p, ap %p, vp %p, off %llx",
1636 			    (void *)adr, (void *)ap, (void *)vp, offset);
1637 			/*NOTREACHED*/
1638 		}
1639 
1640 		if (rw == S_WRITE) {
1641 			hat_setrefmod(pp);
1642 		} else if (rw != S_OTHER) {
1643 			hat_setref(pp);
1644 		}
1645 		page_unlock(pp);
1646 	}
1647 
1648 softlock_decrement:
1649 	npages = btopr(len);
1650 	ASSERT(shmd->shm_softlockcnt >= npages);
1651 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -npages);
1652 	if (shmd->shm_softlockcnt == 0) {
1653 		/*
1654 		 * All SOFTLOCKS are gone. Wakeup any waiting
1655 		 * unmappers so they can try again to unmap.
1656 		 * Check for waiters first without the mutex
1657 		 * held so we don't always grab the mutex on
1658 		 * softunlocks.
1659 		 */
1660 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1661 			mutex_enter(&seg->s_as->a_contents);
1662 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1663 				AS_CLRUNMAPWAIT(seg->s_as);
1664 				cv_broadcast(&seg->s_as->a_cv);
1665 			}
1666 			mutex_exit(&seg->s_as->a_contents);
1667 		}
1668 	}
1669 }
1670 
1671 int
1672 segspt_shmattach(struct seg *seg, caddr_t *argsp)
1673 {
1674 	struct shm_data *shmd_arg = (struct shm_data *)argsp;
1675 	struct shm_data *shmd;
1676 	struct anon_map *shm_amp = shmd_arg->shm_amp;
1677 	struct spt_data *sptd;
1678 	int error = 0;
1679 
1680 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
1681 
1682 	shmd = kmem_zalloc((sizeof (*shmd)), KM_NOSLEEP);
1683 	if (shmd == NULL)
1684 		return (ENOMEM);
1685 
1686 	shmd->shm_sptas = shmd_arg->shm_sptas;
1687 	shmd->shm_amp = shm_amp;
1688 	shmd->shm_sptseg = shmd_arg->shm_sptseg;
1689 
1690 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, shm_amp, 0,
1691 	    NULL, 0, seg->s_size);
1692 
1693 	mutex_init(&shmd->shm_segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
1694 
1695 	seg->s_data = (void *)shmd;
1696 	seg->s_ops = &segspt_shmops;
1697 	seg->s_szc = shmd->shm_sptseg->s_szc;
1698 	sptd = shmd->shm_sptseg->s_data;
1699 
1700 	if (sptd->spt_flags & SHM_PAGEABLE) {
1701 		if ((shmd->shm_vpage = kmem_zalloc(btopr(shm_amp->size),
1702 		    KM_NOSLEEP)) == NULL) {
1703 			seg->s_data = (void *)NULL;
1704 			kmem_free(shmd, (sizeof (*shmd)));
1705 			return (ENOMEM);
1706 		}
1707 		shmd->shm_lckpgs = 0;
1708 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
1709 			if ((error = hat_share(seg->s_as->a_hat, seg->s_base,
1710 			    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1711 			    seg->s_size, seg->s_szc)) != 0) {
1712 				kmem_free(shmd->shm_vpage,
1713 				    btopr(shm_amp->size));
1714 			}
1715 		}
1716 	} else {
1717 		error = hat_share(seg->s_as->a_hat, seg->s_base,
1718 		    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1719 		    seg->s_size, seg->s_szc);
1720 	}
1721 	if (error) {
1722 		seg->s_szc = 0;
1723 		seg->s_data = (void *)NULL;
1724 		kmem_free(shmd, (sizeof (*shmd)));
1725 	} else {
1726 		ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1727 		shm_amp->refcnt++;
1728 		ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1729 	}
1730 	return (error);
1731 }
1732 
1733 int
1734 segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize)
1735 {
1736 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1737 	int reclaim = 1;
1738 
1739 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
1740 retry:
1741 	if (shmd->shm_softlockcnt > 0) {
1742 		if (reclaim == 1) {
1743 			segspt_purge(seg);
1744 			reclaim = 0;
1745 			goto retry;
1746 		}
1747 		return (EAGAIN);
1748 	}
1749 
1750 	if (ssize != seg->s_size) {
1751 #ifdef DEBUG
1752 		cmn_err(CE_WARN, "Incompatible ssize %lx s_size %lx\n",
1753 		    ssize, seg->s_size);
1754 #endif
1755 		return (EINVAL);
1756 	}
1757 
1758 	(void) segspt_shmlockop(seg, raddr, shmd->shm_amp->size, 0, MC_UNLOCK,
1759 	    NULL, 0);
1760 	hat_unshare(seg->s_as->a_hat, raddr, ssize, seg->s_szc);
1761 
1762 	seg_free(seg);
1763 
1764 	return (0);
1765 }
1766 
1767 void
1768 segspt_shmfree(struct seg *seg)
1769 {
1770 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1771 	struct anon_map *shm_amp = shmd->shm_amp;
1772 
1773 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
1774 
1775 	(void) segspt_shmlockop(seg, seg->s_base, shm_amp->size, 0,
1776 	    MC_UNLOCK, NULL, 0);
1777 
1778 	/*
1779 	 * Need to increment refcnt when attaching
1780 	 * and decrement when detaching because of dup().
1781 	 */
1782 	ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1783 	shm_amp->refcnt--;
1784 	ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1785 
1786 	if (shmd->shm_vpage) {	/* only for DISM */
1787 		kmem_free(shmd->shm_vpage, btopr(shm_amp->size));
1788 		shmd->shm_vpage = NULL;
1789 	}
1790 
1791 	/*
1792 	 * Take shm_segfree_syncmtx lock to let segspt_reclaim() finish if it's
1793 	 * still working with this segment without holding as lock.
1794 	 */
1795 	ASSERT(shmd->shm_softlockcnt == 0);
1796 	mutex_enter(&shmd->shm_segfree_syncmtx);
1797 	mutex_destroy(&shmd->shm_segfree_syncmtx);
1798 
1799 	kmem_free(shmd, sizeof (*shmd));
1800 }
1801 
1802 /*ARGSUSED*/
1803 int
1804 segspt_shmsetprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
1805 {
1806 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1807 
1808 	/*
1809 	 * Shared page table is more than shared mapping.
1810 	 *  Individual process sharing page tables can't change prot
1811 	 *  because there is only one set of page tables.
1812 	 *  This will be allowed after private page table is
1813 	 *  supported.
1814 	 */
1815 /* need to return correct status error? */
1816 	return (0);
1817 }
1818 
1819 
1820 faultcode_t
1821 segspt_dismfault(struct hat *hat, struct seg *seg, caddr_t addr,
1822     size_t len, enum fault_type type, enum seg_rw rw)
1823 {
1824 	struct  shm_data 	*shmd = (struct shm_data *)seg->s_data;
1825 	struct  seg		*sptseg = shmd->shm_sptseg;
1826 	struct  as		*curspt = shmd->shm_sptas;
1827 	struct  spt_data 	*sptd = sptseg->s_data;
1828 	pgcnt_t npages;
1829 	size_t  size;
1830 	caddr_t segspt_addr, shm_addr;
1831 	page_t  **ppa;
1832 	int	i;
1833 	ulong_t an_idx = 0;
1834 	int	err = 0;
1835 	int	dyn_ism_unmap = hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0);
1836 	size_t	pgsz;
1837 	pgcnt_t	pgcnt;
1838 	caddr_t	a;
1839 	pgcnt_t	pidx;
1840 
1841 #ifdef lint
1842 	hat = hat;
1843 #endif
1844 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1845 
1846 	/*
1847 	 * Because of the way spt is implemented
1848 	 * the realsize of the segment does not have to be
1849 	 * equal to the segment size itself. The segment size is
1850 	 * often in multiples of a page size larger than PAGESIZE.
1851 	 * The realsize is rounded up to the nearest PAGESIZE
1852 	 * based on what the user requested. This is a bit of
1853 	 * ungliness that is historical but not easily fixed
1854 	 * without re-designing the higher levels of ISM.
1855 	 */
1856 	ASSERT(addr >= seg->s_base);
1857 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
1858 		return (FC_NOMAP);
1859 	/*
1860 	 * For all of the following cases except F_PROT, we need to
1861 	 * make any necessary adjustments to addr and len
1862 	 * and get all of the necessary page_t's into an array called ppa[].
1863 	 *
1864 	 * The code in shmat() forces base addr and len of ISM segment
1865 	 * to be aligned to largest page size supported. Therefore,
1866 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
1867 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
1868 	 * in large pagesize chunks, or else we will screw up the HAT
1869 	 * layer by calling hat_memload_array() with differing page sizes
1870 	 * over a given virtual range.
1871 	 */
1872 	pgsz = page_get_pagesize(sptseg->s_szc);
1873 	pgcnt = page_get_pagecnt(sptseg->s_szc);
1874 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
1875 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
1876 	npages = btopr(size);
1877 
1878 	/*
1879 	 * Now we need to convert from addr in segshm to addr in segspt.
1880 	 */
1881 	an_idx = seg_page(seg, shm_addr);
1882 	segspt_addr = sptseg->s_base + ptob(an_idx);
1883 
1884 	ASSERT((segspt_addr + ptob(npages)) <=
1885 	    (sptseg->s_base + sptd->spt_realsize));
1886 	ASSERT(segspt_addr < (sptseg->s_base + sptseg->s_size));
1887 
1888 	switch (type) {
1889 
1890 	case F_SOFTLOCK:
1891 
1892 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
1893 		/*
1894 		 * Fall through to the F_INVAL case to load up the hat layer
1895 		 * entries with the HAT_LOAD_LOCK flag.
1896 		 */
1897 		/* FALLTHRU */
1898 	case F_INVAL:
1899 
1900 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
1901 			return (FC_NOMAP);
1902 
1903 		ppa = kmem_zalloc(npages * sizeof (page_t *), KM_SLEEP);
1904 
1905 		err = spt_anon_getpages(sptseg, segspt_addr, size, ppa);
1906 		if (err != 0) {
1907 			if (type == F_SOFTLOCK) {
1908 				atomic_add_long((ulong_t *)(
1909 				    &(shmd->shm_softlockcnt)), -npages);
1910 			}
1911 			goto dism_err;
1912 		}
1913 		AS_LOCK_ENTER(sptseg->s_as, RW_READER);
1914 		a = segspt_addr;
1915 		pidx = 0;
1916 		if (type == F_SOFTLOCK) {
1917 
1918 			/*
1919 			 * Load up the translation keeping it
1920 			 * locked and don't unlock the page.
1921 			 */
1922 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
1923 				hat_memload_array(sptseg->s_as->a_hat,
1924 				    a, pgsz, &ppa[pidx], sptd->spt_prot,
1925 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
1926 			}
1927 		} else {
1928 			if (hat == seg->s_as->a_hat) {
1929 
1930 				/*
1931 				 * Migrate pages marked for migration
1932 				 */
1933 				if (lgrp_optimizations())
1934 					page_migrate(seg, shm_addr, ppa,
1935 					    npages);
1936 
1937 				/* CPU HAT */
1938 				for (; pidx < npages;
1939 				    a += pgsz, pidx += pgcnt) {
1940 					hat_memload_array(sptseg->s_as->a_hat,
1941 					    a, pgsz, &ppa[pidx],
1942 					    sptd->spt_prot,
1943 					    HAT_LOAD_SHARE);
1944 				}
1945 			} else {
1946 				/* XHAT. Pass real address */
1947 				hat_memload_array(hat, shm_addr,
1948 				    size, ppa, sptd->spt_prot, HAT_LOAD_SHARE);
1949 			}
1950 
1951 			/*
1952 			 * And now drop the SE_SHARED lock(s).
1953 			 */
1954 			if (dyn_ism_unmap) {
1955 				for (i = 0; i < npages; i++) {
1956 					page_unlock(ppa[i]);
1957 				}
1958 			}
1959 		}
1960 
1961 		if (!dyn_ism_unmap) {
1962 			if (hat_share(seg->s_as->a_hat, shm_addr,
1963 			    curspt->a_hat, segspt_addr, ptob(npages),
1964 			    seg->s_szc) != 0) {
1965 				panic("hat_share err in DISM fault");
1966 				/* NOTREACHED */
1967 			}
1968 			if (type == F_INVAL) {
1969 				for (i = 0; i < npages; i++) {
1970 					page_unlock(ppa[i]);
1971 				}
1972 			}
1973 		}
1974 		AS_LOCK_EXIT(sptseg->s_as);
1975 dism_err:
1976 		kmem_free(ppa, npages * sizeof (page_t *));
1977 		return (err);
1978 
1979 	case F_SOFTUNLOCK:
1980 
1981 		/*
1982 		 * This is a bit ugly, we pass in the real seg pointer,
1983 		 * but the segspt_addr is the virtual address within the
1984 		 * dummy seg.
1985 		 */
1986 		segspt_softunlock(seg, segspt_addr, size, rw);
1987 		return (0);
1988 
1989 	case F_PROT:
1990 
1991 		/*
1992 		 * This takes care of the unusual case where a user
1993 		 * allocates a stack in shared memory and a register
1994 		 * window overflow is written to that stack page before
1995 		 * it is otherwise modified.
1996 		 *
1997 		 * We can get away with this because ISM segments are
1998 		 * always rw. Other than this unusual case, there
1999 		 * should be no instances of protection violations.
2000 		 */
2001 		return (0);
2002 
2003 	default:
2004 #ifdef DEBUG
2005 		panic("segspt_dismfault default type?");
2006 #else
2007 		return (FC_NOMAP);
2008 #endif
2009 	}
2010 }
2011 
2012 
2013 faultcode_t
2014 segspt_shmfault(struct hat *hat, struct seg *seg, caddr_t addr,
2015     size_t len, enum fault_type type, enum seg_rw rw)
2016 {
2017 	struct shm_data 	*shmd = (struct shm_data *)seg->s_data;
2018 	struct seg		*sptseg = shmd->shm_sptseg;
2019 	struct as		*curspt = shmd->shm_sptas;
2020 	struct spt_data 	*sptd   = sptseg->s_data;
2021 	pgcnt_t npages;
2022 	size_t size;
2023 	caddr_t sptseg_addr, shm_addr;
2024 	page_t *pp, **ppa;
2025 	int	i;
2026 	u_offset_t offset;
2027 	ulong_t anon_index = 0;
2028 	struct vnode *vp;
2029 	struct anon_map *amp;		/* XXX - for locknest */
2030 	struct anon *ap = NULL;
2031 	size_t		pgsz;
2032 	pgcnt_t		pgcnt;
2033 	caddr_t		a;
2034 	pgcnt_t		pidx;
2035 	size_t		sz;
2036 
2037 #ifdef lint
2038 	hat = hat;
2039 #endif
2040 
2041 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2042 
2043 	if (sptd->spt_flags & SHM_PAGEABLE) {
2044 		return (segspt_dismfault(hat, seg, addr, len, type, rw));
2045 	}
2046 
2047 	/*
2048 	 * Because of the way spt is implemented
2049 	 * the realsize of the segment does not have to be
2050 	 * equal to the segment size itself. The segment size is
2051 	 * often in multiples of a page size larger than PAGESIZE.
2052 	 * The realsize is rounded up to the nearest PAGESIZE
2053 	 * based on what the user requested. This is a bit of
2054 	 * ungliness that is historical but not easily fixed
2055 	 * without re-designing the higher levels of ISM.
2056 	 */
2057 	ASSERT(addr >= seg->s_base);
2058 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
2059 		return (FC_NOMAP);
2060 	/*
2061 	 * For all of the following cases except F_PROT, we need to
2062 	 * make any necessary adjustments to addr and len
2063 	 * and get all of the necessary page_t's into an array called ppa[].
2064 	 *
2065 	 * The code in shmat() forces base addr and len of ISM segment
2066 	 * to be aligned to largest page size supported. Therefore,
2067 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
2068 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
2069 	 * in large pagesize chunks, or else we will screw up the HAT
2070 	 * layer by calling hat_memload_array() with differing page sizes
2071 	 * over a given virtual range.
2072 	 */
2073 	pgsz = page_get_pagesize(sptseg->s_szc);
2074 	pgcnt = page_get_pagecnt(sptseg->s_szc);
2075 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
2076 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
2077 	npages = btopr(size);
2078 
2079 	/*
2080 	 * Now we need to convert from addr in segshm to addr in segspt.
2081 	 */
2082 	anon_index = seg_page(seg, shm_addr);
2083 	sptseg_addr = sptseg->s_base + ptob(anon_index);
2084 
2085 	/*
2086 	 * And now we may have to adjust npages downward if we have
2087 	 * exceeded the realsize of the segment or initial anon
2088 	 * allocations.
2089 	 */
2090 	if ((sptseg_addr + ptob(npages)) >
2091 	    (sptseg->s_base + sptd->spt_realsize))
2092 		size = (sptseg->s_base + sptd->spt_realsize) - sptseg_addr;
2093 
2094 	npages = btopr(size);
2095 
2096 	ASSERT(sptseg_addr < (sptseg->s_base + sptseg->s_size));
2097 	ASSERT((sptd->spt_flags & SHM_PAGEABLE) == 0);
2098 
2099 	switch (type) {
2100 
2101 	case F_SOFTLOCK:
2102 
2103 		/*
2104 		 * availrmem is decremented once during anon_swap_adjust()
2105 		 * and is incremented during the anon_unresv(), which is
2106 		 * called from shm_rm_amp() when the segment is destroyed.
2107 		 */
2108 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
2109 		/*
2110 		 * Some platforms assume that ISM pages are SE_SHARED
2111 		 * locked for the entire life of the segment.
2112 		 */
2113 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0))
2114 			return (0);
2115 		/*
2116 		 * Fall through to the F_INVAL case to load up the hat layer
2117 		 * entries with the HAT_LOAD_LOCK flag.
2118 		 */
2119 
2120 		/* FALLTHRU */
2121 	case F_INVAL:
2122 
2123 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
2124 			return (FC_NOMAP);
2125 
2126 		/*
2127 		 * Some platforms that do NOT support DYNAMIC_ISM_UNMAP
2128 		 * may still rely on this call to hat_share(). That
2129 		 * would imply that those hat's can fault on a
2130 		 * HAT_LOAD_LOCK translation, which would seem
2131 		 * contradictory.
2132 		 */
2133 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2134 			if (hat_share(seg->s_as->a_hat, seg->s_base,
2135 			    curspt->a_hat, sptseg->s_base,
2136 			    sptseg->s_size, sptseg->s_szc) != 0) {
2137 				panic("hat_share error in ISM fault");
2138 				/*NOTREACHED*/
2139 			}
2140 			return (0);
2141 		}
2142 		ppa = kmem_zalloc(sizeof (page_t *) * npages, KM_SLEEP);
2143 
2144 		/*
2145 		 * I see no need to lock the real seg,
2146 		 * here, because all of our work will be on the underlying
2147 		 * dummy seg.
2148 		 *
2149 		 * sptseg_addr and npages now account for large pages.
2150 		 */
2151 		amp = sptd->spt_amp;
2152 		ASSERT(amp != NULL);
2153 		anon_index = seg_page(sptseg, sptseg_addr);
2154 
2155 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2156 		for (i = 0; i < npages; i++) {
2157 			ap = anon_get_ptr(amp->ahp, anon_index++);
2158 			ASSERT(ap != NULL);
2159 			swap_xlate(ap, &vp, &offset);
2160 			pp = page_lookup(vp, offset, SE_SHARED);
2161 			ASSERT(pp != NULL);
2162 			ppa[i] = pp;
2163 		}
2164 		ANON_LOCK_EXIT(&amp->a_rwlock);
2165 		ASSERT(i == npages);
2166 
2167 		/*
2168 		 * We are already holding the as->a_lock on the user's
2169 		 * real segment, but we need to hold the a_lock on the
2170 		 * underlying dummy as. This is mostly to satisfy the
2171 		 * underlying HAT layer.
2172 		 */
2173 		AS_LOCK_ENTER(sptseg->s_as, RW_READER);
2174 		a = sptseg_addr;
2175 		pidx = 0;
2176 		if (type == F_SOFTLOCK) {
2177 			/*
2178 			 * Load up the translation keeping it
2179 			 * locked and don't unlock the page.
2180 			 */
2181 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
2182 				sz = MIN(pgsz, ptob(npages - pidx));
2183 				hat_memload_array(sptseg->s_as->a_hat, a,
2184 				    sz, &ppa[pidx], sptd->spt_prot,
2185 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
2186 			}
2187 		} else {
2188 			if (hat == seg->s_as->a_hat) {
2189 
2190 				/*
2191 				 * Migrate pages marked for migration.
2192 				 */
2193 				if (lgrp_optimizations())
2194 					page_migrate(seg, shm_addr, ppa,
2195 					    npages);
2196 
2197 				/* CPU HAT */
2198 				for (; pidx < npages;
2199 				    a += pgsz, pidx += pgcnt) {
2200 					sz = MIN(pgsz, ptob(npages - pidx));
2201 					hat_memload_array(sptseg->s_as->a_hat,
2202 					    a, sz, &ppa[pidx],
2203 					    sptd->spt_prot, HAT_LOAD_SHARE);
2204 				}
2205 			} else {
2206 				/* XHAT. Pass real address */
2207 				hat_memload_array(hat, shm_addr,
2208 				    ptob(npages), ppa, sptd->spt_prot,
2209 				    HAT_LOAD_SHARE);
2210 			}
2211 
2212 			/*
2213 			 * And now drop the SE_SHARED lock(s).
2214 			 */
2215 			for (i = 0; i < npages; i++)
2216 				page_unlock(ppa[i]);
2217 		}
2218 		AS_LOCK_EXIT(sptseg->s_as);
2219 
2220 		kmem_free(ppa, sizeof (page_t *) * npages);
2221 		return (0);
2222 	case F_SOFTUNLOCK:
2223 
2224 		/*
2225 		 * This is a bit ugly, we pass in the real seg pointer,
2226 		 * but the sptseg_addr is the virtual address within the
2227 		 * dummy seg.
2228 		 */
2229 		segspt_softunlock(seg, sptseg_addr, ptob(npages), rw);
2230 		return (0);
2231 
2232 	case F_PROT:
2233 
2234 		/*
2235 		 * This takes care of the unusual case where a user
2236 		 * allocates a stack in shared memory and a register
2237 		 * window overflow is written to that stack page before
2238 		 * it is otherwise modified.
2239 		 *
2240 		 * We can get away with this because ISM segments are
2241 		 * always rw. Other than this unusual case, there
2242 		 * should be no instances of protection violations.
2243 		 */
2244 		return (0);
2245 
2246 	default:
2247 #ifdef DEBUG
2248 		cmn_err(CE_WARN, "segspt_shmfault default type?");
2249 #endif
2250 		return (FC_NOMAP);
2251 	}
2252 }
2253 
2254 /*ARGSUSED*/
2255 static faultcode_t
2256 segspt_shmfaulta(struct seg *seg, caddr_t addr)
2257 {
2258 	return (0);
2259 }
2260 
2261 /*ARGSUSED*/
2262 static int
2263 segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta)
2264 {
2265 	return (0);
2266 }
2267 
2268 /*ARGSUSED*/
2269 static size_t
2270 segspt_shmswapout(struct seg *seg)
2271 {
2272 	return (0);
2273 }
2274 
2275 /*
2276  * duplicate the shared page tables
2277  */
2278 int
2279 segspt_shmdup(struct seg *seg, struct seg *newseg)
2280 {
2281 	struct shm_data		*shmd = (struct shm_data *)seg->s_data;
2282 	struct anon_map 	*amp = shmd->shm_amp;
2283 	struct shm_data 	*shmd_new;
2284 	struct seg		*spt_seg = shmd->shm_sptseg;
2285 	struct spt_data		*sptd = spt_seg->s_data;
2286 	int			error = 0;
2287 
2288 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
2289 
2290 	shmd_new = kmem_zalloc((sizeof (*shmd_new)), KM_SLEEP);
2291 	newseg->s_data = (void *)shmd_new;
2292 	shmd_new->shm_sptas = shmd->shm_sptas;
2293 	shmd_new->shm_amp = amp;
2294 	shmd_new->shm_sptseg = shmd->shm_sptseg;
2295 	newseg->s_ops = &segspt_shmops;
2296 	newseg->s_szc = seg->s_szc;
2297 	ASSERT(seg->s_szc == shmd->shm_sptseg->s_szc);
2298 
2299 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2300 	amp->refcnt++;
2301 	ANON_LOCK_EXIT(&amp->a_rwlock);
2302 
2303 	if (sptd->spt_flags & SHM_PAGEABLE) {
2304 		shmd_new->shm_vpage = kmem_zalloc(btopr(amp->size), KM_SLEEP);
2305 		shmd_new->shm_lckpgs = 0;
2306 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2307 			if ((error = hat_share(newseg->s_as->a_hat,
2308 			    newseg->s_base, shmd->shm_sptas->a_hat, SEGSPTADDR,
2309 			    seg->s_size, seg->s_szc)) != 0) {
2310 				kmem_free(shmd_new->shm_vpage,
2311 				    btopr(amp->size));
2312 			}
2313 		}
2314 		return (error);
2315 	} else {
2316 		return (hat_share(newseg->s_as->a_hat, newseg->s_base,
2317 		    shmd->shm_sptas->a_hat, SEGSPTADDR, seg->s_size,
2318 		    seg->s_szc));
2319 
2320 	}
2321 }
2322 
2323 /*ARGSUSED*/
2324 int
2325 segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size, uint_t prot)
2326 {
2327 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2328 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2329 
2330 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2331 
2332 	/*
2333 	 * ISM segment is always rw.
2334 	 */
2335 	return (((sptd->spt_prot & prot) != prot) ? EACCES : 0);
2336 }
2337 
2338 /*
2339  * Return an array of locked large pages, for empty slots allocate
2340  * private zero-filled anon pages.
2341  */
2342 static int
2343 spt_anon_getpages(
2344 	struct seg *sptseg,
2345 	caddr_t sptaddr,
2346 	size_t len,
2347 	page_t *ppa[])
2348 {
2349 	struct  spt_data *sptd = sptseg->s_data;
2350 	struct  anon_map *amp = sptd->spt_amp;
2351 	enum 	seg_rw rw = sptd->spt_prot;
2352 	uint_t	szc = sptseg->s_szc;
2353 	size_t	pg_sz, share_sz = page_get_pagesize(szc);
2354 	pgcnt_t	lp_npgs;
2355 	caddr_t	lp_addr, e_sptaddr;
2356 	uint_t	vpprot, ppa_szc = 0;
2357 	struct  vpage *vpage = NULL;
2358 	ulong_t	j, ppa_idx;
2359 	int	err, ierr = 0;
2360 	pgcnt_t	an_idx;
2361 	anon_sync_obj_t cookie;
2362 	int anon_locked = 0;
2363 	pgcnt_t amp_pgs;
2364 
2365 
2366 	ASSERT(IS_P2ALIGNED(sptaddr, share_sz) && IS_P2ALIGNED(len, share_sz));
2367 	ASSERT(len != 0);
2368 
2369 	pg_sz = share_sz;
2370 	lp_npgs = btop(pg_sz);
2371 	lp_addr = sptaddr;
2372 	e_sptaddr = sptaddr + len;
2373 	an_idx = seg_page(sptseg, sptaddr);
2374 	ppa_idx = 0;
2375 
2376 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2377 
2378 	amp_pgs = page_get_pagecnt(amp->a_szc);
2379 
2380 	/*CONSTCOND*/
2381 	while (1) {
2382 		for (; lp_addr < e_sptaddr;
2383 		    an_idx += lp_npgs, lp_addr += pg_sz, ppa_idx += lp_npgs) {
2384 
2385 			/*
2386 			 * If we're currently locked, and we get to a new
2387 			 * page, unlock our current anon chunk.
2388 			 */
2389 			if (anon_locked && P2PHASE(an_idx, amp_pgs) == 0) {
2390 				anon_array_exit(&cookie);
2391 				anon_locked = 0;
2392 			}
2393 			if (!anon_locked) {
2394 				anon_array_enter(amp, an_idx, &cookie);
2395 				anon_locked = 1;
2396 			}
2397 			ppa_szc = (uint_t)-1;
2398 			ierr = anon_map_getpages(amp, an_idx, szc, sptseg,
2399 			    lp_addr, sptd->spt_prot, &vpprot, &ppa[ppa_idx],
2400 			    &ppa_szc, vpage, rw, 0, segvn_anypgsz, 0, kcred);
2401 
2402 			if (ierr != 0) {
2403 				if (ierr > 0) {
2404 					err = FC_MAKE_ERR(ierr);
2405 					goto lpgs_err;
2406 				}
2407 				break;
2408 			}
2409 		}
2410 		if (lp_addr == e_sptaddr) {
2411 			break;
2412 		}
2413 		ASSERT(lp_addr < e_sptaddr);
2414 
2415 		/*
2416 		 * ierr == -1 means we failed to allocate a large page.
2417 		 * so do a size down operation.
2418 		 *
2419 		 * ierr == -2 means some other process that privately shares
2420 		 * pages with this process has allocated a larger page and we
2421 		 * need to retry with larger pages. So do a size up
2422 		 * operation. This relies on the fact that large pages are
2423 		 * never partially shared i.e. if we share any constituent
2424 		 * page of a large page with another process we must share the
2425 		 * entire large page. Note this cannot happen for SOFTLOCK
2426 		 * case, unless current address (lpaddr) is at the beginning
2427 		 * of the next page size boundary because the other process
2428 		 * couldn't have relocated locked pages.
2429 		 */
2430 		ASSERT(ierr == -1 || ierr == -2);
2431 		if (segvn_anypgsz) {
2432 			ASSERT(ierr == -2 || szc != 0);
2433 			ASSERT(ierr == -1 || szc < sptseg->s_szc);
2434 			szc = (ierr == -1) ? szc - 1 : szc + 1;
2435 		} else {
2436 			/*
2437 			 * For faults and segvn_anypgsz == 0
2438 			 * we need to be careful not to loop forever
2439 			 * if existing page is found with szc other
2440 			 * than 0 or seg->s_szc. This could be due
2441 			 * to page relocations on behalf of DR or
2442 			 * more likely large page creation. For this
2443 			 * case simply re-size to existing page's szc
2444 			 * if returned by anon_map_getpages().
2445 			 */
2446 			if (ppa_szc == (uint_t)-1) {
2447 				szc = (ierr == -1) ? 0 : sptseg->s_szc;
2448 			} else {
2449 				ASSERT(ppa_szc <= sptseg->s_szc);
2450 				ASSERT(ierr == -2 || ppa_szc < szc);
2451 				ASSERT(ierr == -1 || ppa_szc > szc);
2452 				szc = ppa_szc;
2453 			}
2454 		}
2455 		pg_sz = page_get_pagesize(szc);
2456 		lp_npgs = btop(pg_sz);
2457 		ASSERT(IS_P2ALIGNED(lp_addr, pg_sz));
2458 	}
2459 	if (anon_locked) {
2460 		anon_array_exit(&cookie);
2461 	}
2462 	ANON_LOCK_EXIT(&amp->a_rwlock);
2463 	return (0);
2464 
2465 lpgs_err:
2466 	if (anon_locked) {
2467 		anon_array_exit(&cookie);
2468 	}
2469 	ANON_LOCK_EXIT(&amp->a_rwlock);
2470 	for (j = 0; j < ppa_idx; j++)
2471 		page_unlock(ppa[j]);
2472 	return (err);
2473 }
2474 
2475 /*
2476  * count the number of bytes in a set of spt pages that are currently not
2477  * locked
2478  */
2479 static rctl_qty_t
2480 spt_unlockedbytes(pgcnt_t npages, page_t **ppa)
2481 {
2482 	ulong_t	i;
2483 	rctl_qty_t unlocked = 0;
2484 
2485 	for (i = 0; i < npages; i++) {
2486 		if (ppa[i]->p_lckcnt == 0)
2487 			unlocked += PAGESIZE;
2488 	}
2489 	return (unlocked);
2490 }
2491 
2492 extern	u_longlong_t randtick(void);
2493 /* number of locks to reserve/skip by spt_lockpages() and spt_unlockpages() */
2494 #define	NLCK	(NCPU_P2)
2495 /* Random number with a range [0, n-1], n must be power of two */
2496 #define	RAND_P2(n)	\
2497 	((((long)curthread >> PTR24_LSB) ^ (long)randtick()) & ((n) - 1))
2498 
2499 int
2500 spt_lockpages(struct seg *seg, pgcnt_t anon_index, pgcnt_t npages,
2501     page_t **ppa, ulong_t *lockmap, size_t pos,
2502     rctl_qty_t *locked)
2503 {
2504 	struct	shm_data *shmd = seg->s_data;
2505 	struct	spt_data *sptd = shmd->shm_sptseg->s_data;
2506 	ulong_t	i;
2507 	int	kernel;
2508 	pgcnt_t	nlck = 0;
2509 	int	rv = 0;
2510 	int	use_reserved = 1;
2511 
2512 	/* return the number of bytes actually locked */
2513 	*locked = 0;
2514 
2515 	/*
2516 	 * To avoid contention on freemem_lock, availrmem and pages_locked
2517 	 * global counters are updated only every nlck locked pages instead of
2518 	 * every time.  Reserve nlck locks up front and deduct from this
2519 	 * reservation for each page that requires a lock.  When the reservation
2520 	 * is consumed, reserve again.  nlck is randomized, so the competing
2521 	 * threads do not fall into a cyclic lock contention pattern. When
2522 	 * memory is low, the lock ahead is disabled, and instead page_pp_lock()
2523 	 * is used to lock pages.
2524 	 */
2525 	for (i = 0; i < npages; anon_index++, pos++, i++) {
2526 		if (nlck == 0 && use_reserved == 1) {
2527 			nlck = NLCK + RAND_P2(NLCK);
2528 			/* if fewer loops left, decrease nlck */
2529 			nlck = MIN(nlck, npages - i);
2530 			/*
2531 			 * Reserve nlck locks up front and deduct from this
2532 			 * reservation for each page that requires a lock.  When
2533 			 * the reservation is consumed, reserve again.
2534 			 */
2535 			mutex_enter(&freemem_lock);
2536 			if ((availrmem - nlck) < pages_pp_maximum) {
2537 				/* Do not do advance memory reserves */
2538 				use_reserved = 0;
2539 			} else {
2540 				availrmem	-= nlck;
2541 				pages_locked	+= nlck;
2542 			}
2543 			mutex_exit(&freemem_lock);
2544 		}
2545 		if (!(shmd->shm_vpage[anon_index] & DISM_PG_LOCKED)) {
2546 			if (sptd->spt_ppa_lckcnt[anon_index] <
2547 			    (ushort_t)DISM_LOCK_MAX) {
2548 				if (++sptd->spt_ppa_lckcnt[anon_index] ==
2549 				    (ushort_t)DISM_LOCK_MAX) {
2550 					cmn_err(CE_WARN,
2551 					    "DISM page lock limit "
2552 					    "reached on DISM offset 0x%lx\n",
2553 					    anon_index << PAGESHIFT);
2554 				}
2555 				kernel = (sptd->spt_ppa &&
2556 				    sptd->spt_ppa[anon_index]);
2557 				if (!page_pp_lock(ppa[i], 0, kernel ||
2558 				    use_reserved)) {
2559 					sptd->spt_ppa_lckcnt[anon_index]--;
2560 					rv = EAGAIN;
2561 					break;
2562 				}
2563 				/* if this is a newly locked page, count it */
2564 				if (ppa[i]->p_lckcnt == 1) {
2565 					if (kernel == 0 && use_reserved == 1)
2566 						nlck--;
2567 					*locked += PAGESIZE;
2568 				}
2569 				shmd->shm_lckpgs++;
2570 				shmd->shm_vpage[anon_index] |= DISM_PG_LOCKED;
2571 				if (lockmap != NULL)
2572 					BT_SET(lockmap, pos);
2573 			}
2574 		}
2575 	}
2576 	/* Return unused lock reservation */
2577 	if (nlck != 0 && use_reserved == 1) {
2578 		mutex_enter(&freemem_lock);
2579 		availrmem	+= nlck;
2580 		pages_locked	-= nlck;
2581 		mutex_exit(&freemem_lock);
2582 	}
2583 
2584 	return (rv);
2585 }
2586 
2587 int
2588 spt_unlockpages(struct seg *seg, pgcnt_t anon_index, pgcnt_t npages,
2589     rctl_qty_t *unlocked)
2590 {
2591 	struct shm_data	*shmd = seg->s_data;
2592 	struct spt_data	*sptd = shmd->shm_sptseg->s_data;
2593 	struct anon_map	*amp = sptd->spt_amp;
2594 	struct anon 	*ap;
2595 	struct vnode 	*vp;
2596 	u_offset_t 	off;
2597 	struct page	*pp;
2598 	int		kernel;
2599 	anon_sync_obj_t	cookie;
2600 	ulong_t		i;
2601 	pgcnt_t		nlck = 0;
2602 	pgcnt_t		nlck_limit = NLCK;
2603 
2604 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2605 	for (i = 0; i < npages; i++, anon_index++) {
2606 		if (shmd->shm_vpage[anon_index] & DISM_PG_LOCKED) {
2607 			anon_array_enter(amp, anon_index, &cookie);
2608 			ap = anon_get_ptr(amp->ahp, anon_index);
2609 			ASSERT(ap);
2610 
2611 			swap_xlate(ap, &vp, &off);
2612 			anon_array_exit(&cookie);
2613 			pp = page_lookup(vp, off, SE_SHARED);
2614 			ASSERT(pp);
2615 			/*
2616 			 * availrmem is decremented only for pages which are not
2617 			 * in seg pcache, for pages in seg pcache availrmem was
2618 			 * decremented in _dismpagelock()
2619 			 */
2620 			kernel = (sptd->spt_ppa && sptd->spt_ppa[anon_index]);
2621 			ASSERT(pp->p_lckcnt > 0);
2622 
2623 			/*
2624 			 * lock page but do not change availrmem, we do it
2625 			 * ourselves every nlck loops.
2626 			 */
2627 			page_pp_unlock(pp, 0, 1);
2628 			if (pp->p_lckcnt == 0) {
2629 				if (kernel == 0)
2630 					nlck++;
2631 				*unlocked += PAGESIZE;
2632 			}
2633 			page_unlock(pp);
2634 			shmd->shm_vpage[anon_index] &= ~DISM_PG_LOCKED;
2635 			sptd->spt_ppa_lckcnt[anon_index]--;
2636 			shmd->shm_lckpgs--;
2637 		}
2638 
2639 		/*
2640 		 * To reduce freemem_lock contention, do not update availrmem
2641 		 * until at least NLCK pages have been unlocked.
2642 		 * 1. No need to update if nlck is zero
2643 		 * 2. Always update if the last iteration
2644 		 */
2645 		if (nlck > 0 && (nlck == nlck_limit || i == npages - 1)) {
2646 			mutex_enter(&freemem_lock);
2647 			availrmem	+= nlck;
2648 			pages_locked	-= nlck;
2649 			mutex_exit(&freemem_lock);
2650 			nlck = 0;
2651 			nlck_limit = NLCK + RAND_P2(NLCK);
2652 		}
2653 	}
2654 	ANON_LOCK_EXIT(&amp->a_rwlock);
2655 
2656 	return (0);
2657 }
2658 
2659 /*ARGSUSED*/
2660 static int
2661 segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
2662     int attr, int op, ulong_t *lockmap, size_t pos)
2663 {
2664 	struct shm_data *shmd = seg->s_data;
2665 	struct seg	*sptseg = shmd->shm_sptseg;
2666 	struct spt_data *sptd = sptseg->s_data;
2667 	struct kshmid	*sp = sptd->spt_amp->a_sp;
2668 	pgcnt_t		npages, a_npages;
2669 	page_t		**ppa;
2670 	pgcnt_t 	an_idx, a_an_idx, ppa_idx;
2671 	caddr_t		spt_addr, a_addr;	/* spt and aligned address */
2672 	size_t		a_len;			/* aligned len */
2673 	size_t		share_sz;
2674 	ulong_t		i;
2675 	int		sts = 0;
2676 	rctl_qty_t	unlocked = 0;
2677 	rctl_qty_t	locked = 0;
2678 	struct proc	*p = curproc;
2679 	kproject_t	*proj;
2680 
2681 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2682 	ASSERT(sp != NULL);
2683 
2684 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
2685 		return (0);
2686 	}
2687 
2688 	addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2689 	an_idx = seg_page(seg, addr);
2690 	npages = btopr(len);
2691 
2692 	if (an_idx + npages > btopr(shmd->shm_amp->size)) {
2693 		return (ENOMEM);
2694 	}
2695 
2696 	/*
2697 	 * A shm's project never changes, so no lock needed.
2698 	 * The shm has a hold on the project, so it will not go away.
2699 	 * Since we have a mapping to shm within this zone, we know
2700 	 * that the zone will not go away.
2701 	 */
2702 	proj = sp->shm_perm.ipc_proj;
2703 
2704 	if (op == MC_LOCK) {
2705 
2706 		/*
2707 		 * Need to align addr and size request if they are not
2708 		 * aligned so we can always allocate large page(s) however
2709 		 * we only lock what was requested in initial request.
2710 		 */
2711 		share_sz = page_get_pagesize(sptseg->s_szc);
2712 		a_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_sz);
2713 		a_len = P2ROUNDUP((uintptr_t)(((addr + len) - a_addr)),
2714 		    share_sz);
2715 		a_npages = btop(a_len);
2716 		a_an_idx = seg_page(seg, a_addr);
2717 		spt_addr = sptseg->s_base + ptob(a_an_idx);
2718 		ppa_idx = an_idx - a_an_idx;
2719 
2720 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * a_npages),
2721 		    KM_NOSLEEP)) == NULL) {
2722 			return (ENOMEM);
2723 		}
2724 
2725 		/*
2726 		 * Don't cache any new pages for IO and
2727 		 * flush any cached pages.
2728 		 */
2729 		mutex_enter(&sptd->spt_lock);
2730 		if (sptd->spt_ppa != NULL)
2731 			sptd->spt_flags |= DISM_PPA_CHANGED;
2732 
2733 		sts = spt_anon_getpages(sptseg, spt_addr, a_len, ppa);
2734 		if (sts != 0) {
2735 			mutex_exit(&sptd->spt_lock);
2736 			kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2737 			return (sts);
2738 		}
2739 
2740 		mutex_enter(&sp->shm_mlock);
2741 		/* enforce locked memory rctl */
2742 		unlocked = spt_unlockedbytes(npages, &ppa[ppa_idx]);
2743 
2744 		mutex_enter(&p->p_lock);
2745 		if (rctl_incr_locked_mem(p, proj, unlocked, 0)) {
2746 			mutex_exit(&p->p_lock);
2747 			sts = EAGAIN;
2748 		} else {
2749 			mutex_exit(&p->p_lock);
2750 			sts = spt_lockpages(seg, an_idx, npages,
2751 			    &ppa[ppa_idx], lockmap, pos, &locked);
2752 
2753 			/*
2754 			 * correct locked count if not all pages could be
2755 			 * locked
2756 			 */
2757 			if ((unlocked - locked) > 0) {
2758 				rctl_decr_locked_mem(NULL, proj,
2759 				    (unlocked - locked), 0);
2760 			}
2761 		}
2762 		/*
2763 		 * unlock pages
2764 		 */
2765 		for (i = 0; i < a_npages; i++)
2766 			page_unlock(ppa[i]);
2767 		if (sptd->spt_ppa != NULL)
2768 			sptd->spt_flags |= DISM_PPA_CHANGED;
2769 		mutex_exit(&sp->shm_mlock);
2770 		mutex_exit(&sptd->spt_lock);
2771 
2772 		kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2773 
2774 	} else if (op == MC_UNLOCK) { /* unlock */
2775 		page_t		**ppa;
2776 
2777 		mutex_enter(&sptd->spt_lock);
2778 		if (shmd->shm_lckpgs == 0) {
2779 			mutex_exit(&sptd->spt_lock);
2780 			return (0);
2781 		}
2782 		/*
2783 		 * Don't cache new IO pages.
2784 		 */
2785 		if (sptd->spt_ppa != NULL)
2786 			sptd->spt_flags |= DISM_PPA_CHANGED;
2787 
2788 		mutex_enter(&sp->shm_mlock);
2789 		sts = spt_unlockpages(seg, an_idx, npages, &unlocked);
2790 		if ((ppa = sptd->spt_ppa) != NULL)
2791 			sptd->spt_flags |= DISM_PPA_CHANGED;
2792 		mutex_exit(&sptd->spt_lock);
2793 
2794 		rctl_decr_locked_mem(NULL, proj, unlocked, 0);
2795 		mutex_exit(&sp->shm_mlock);
2796 
2797 		if (ppa != NULL)
2798 			seg_ppurge_wiredpp(ppa);
2799 	}
2800 	return (sts);
2801 }
2802 
2803 /*ARGSUSED*/
2804 int
2805 segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
2806 {
2807 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2808 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2809 	spgcnt_t pgno = seg_page(seg, addr+len) - seg_page(seg, addr) + 1;
2810 
2811 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2812 
2813 	/*
2814 	 * ISM segment is always rw.
2815 	 */
2816 	while (--pgno >= 0)
2817 		*protv++ = sptd->spt_prot;
2818 	return (0);
2819 }
2820 
2821 /*ARGSUSED*/
2822 u_offset_t
2823 segspt_shmgetoffset(struct seg *seg, caddr_t addr)
2824 {
2825 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2826 
2827 	/* Offset does not matter in ISM memory */
2828 
2829 	return ((u_offset_t)0);
2830 }
2831 
2832 /* ARGSUSED */
2833 int
2834 segspt_shmgettype(struct seg *seg, caddr_t addr)
2835 {
2836 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2837 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2838 
2839 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2840 
2841 	/*
2842 	 * The shared memory mapping is always MAP_SHARED, SWAP is only
2843 	 * reserved for DISM
2844 	 */
2845 	return (MAP_SHARED |
2846 	    ((sptd->spt_flags & SHM_PAGEABLE) ? 0 : MAP_NORESERVE));
2847 }
2848 
2849 /*ARGSUSED*/
2850 int
2851 segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
2852 {
2853 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2854 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2855 
2856 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2857 
2858 	*vpp = sptd->spt_vp;
2859 	return (0);
2860 }
2861 
2862 /*
2863  * We need to wait for pending IO to complete to a DISM segment in order for
2864  * pages to get kicked out of the seg_pcache.  120 seconds should be more
2865  * than enough time to wait.
2866  */
2867 static clock_t spt_pcache_wait = 120;
2868 
2869 /*ARGSUSED*/
2870 static int
2871 segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
2872 {
2873 	struct shm_data	*shmd = (struct shm_data *)seg->s_data;
2874 	struct spt_data	*sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2875 	struct anon_map	*amp;
2876 	pgcnt_t pg_idx;
2877 	ushort_t gen;
2878 	clock_t	end_lbolt;
2879 	int writer;
2880 	page_t **ppa;
2881 
2882 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2883 
2884 	if (behav == MADV_FREE || behav == MADV_PURGE) {
2885 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0)
2886 			return (0);
2887 
2888 		amp = sptd->spt_amp;
2889 		pg_idx = seg_page(seg, addr);
2890 
2891 		mutex_enter(&sptd->spt_lock);
2892 		if ((ppa = sptd->spt_ppa) == NULL) {
2893 			mutex_exit(&sptd->spt_lock);
2894 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2895 			(void) anon_disclaim(amp, pg_idx, len, behav, NULL);
2896 			ANON_LOCK_EXIT(&amp->a_rwlock);
2897 			return (0);
2898 		}
2899 
2900 		sptd->spt_flags |= DISM_PPA_CHANGED;
2901 		gen = sptd->spt_gen;
2902 
2903 		mutex_exit(&sptd->spt_lock);
2904 
2905 		/*
2906 		 * Purge all DISM cached pages
2907 		 */
2908 		seg_ppurge_wiredpp(ppa);
2909 
2910 		/*
2911 		 * Drop the AS_LOCK so that other threads can grab it
2912 		 * in the as_pageunlock path and hopefully get the segment
2913 		 * kicked out of the seg_pcache.  We bump the shm_softlockcnt
2914 		 * to keep this segment resident.
2915 		 */
2916 		writer = AS_WRITE_HELD(seg->s_as);
2917 		atomic_inc_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
2918 		AS_LOCK_EXIT(seg->s_as);
2919 
2920 		mutex_enter(&sptd->spt_lock);
2921 
2922 		end_lbolt = ddi_get_lbolt() + (hz * spt_pcache_wait);
2923 
2924 		/*
2925 		 * Try to wait for pages to get kicked out of the seg_pcache.
2926 		 */
2927 		while (sptd->spt_gen == gen &&
2928 		    (sptd->spt_flags & DISM_PPA_CHANGED) &&
2929 		    ddi_get_lbolt() < end_lbolt) {
2930 			if (!cv_timedwait_sig(&sptd->spt_cv,
2931 			    &sptd->spt_lock, end_lbolt)) {
2932 				break;
2933 			}
2934 		}
2935 
2936 		mutex_exit(&sptd->spt_lock);
2937 
2938 		/* Regrab the AS_LOCK and release our hold on the segment */
2939 		AS_LOCK_ENTER(seg->s_as, writer ? RW_WRITER : RW_READER);
2940 		atomic_dec_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
2941 		if (shmd->shm_softlockcnt <= 0) {
2942 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2943 				mutex_enter(&seg->s_as->a_contents);
2944 				if (AS_ISUNMAPWAIT(seg->s_as)) {
2945 					AS_CLRUNMAPWAIT(seg->s_as);
2946 					cv_broadcast(&seg->s_as->a_cv);
2947 				}
2948 				mutex_exit(&seg->s_as->a_contents);
2949 			}
2950 		}
2951 
2952 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2953 		(void) anon_disclaim(amp, pg_idx, len, behav, NULL);
2954 		ANON_LOCK_EXIT(&amp->a_rwlock);
2955 	} else if (lgrp_optimizations() && (behav == MADV_ACCESS_LWP ||
2956 	    behav == MADV_ACCESS_MANY || behav == MADV_ACCESS_DEFAULT)) {
2957 		int			already_set;
2958 		ulong_t			anon_index;
2959 		lgrp_mem_policy_t	policy;
2960 		caddr_t			shm_addr;
2961 		size_t			share_size;
2962 		size_t			size;
2963 		struct seg		*sptseg = shmd->shm_sptseg;
2964 		caddr_t			sptseg_addr;
2965 
2966 		/*
2967 		 * Align address and length to page size of underlying segment
2968 		 */
2969 		share_size = page_get_pagesize(shmd->shm_sptseg->s_szc);
2970 		shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_size);
2971 		size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)),
2972 		    share_size);
2973 
2974 		amp = shmd->shm_amp;
2975 		anon_index = seg_page(seg, shm_addr);
2976 
2977 		/*
2978 		 * And now we may have to adjust size downward if we have
2979 		 * exceeded the realsize of the segment or initial anon
2980 		 * allocations.
2981 		 */
2982 		sptseg_addr = sptseg->s_base + ptob(anon_index);
2983 		if ((sptseg_addr + size) >
2984 		    (sptseg->s_base + sptd->spt_realsize))
2985 			size = (sptseg->s_base + sptd->spt_realsize) -
2986 			    sptseg_addr;
2987 
2988 		/*
2989 		 * Set memory allocation policy for this segment
2990 		 */
2991 		policy = lgrp_madv_to_policy(behav, len, MAP_SHARED);
2992 		already_set = lgrp_shm_policy_set(policy, amp, anon_index,
2993 		    NULL, 0, len);
2994 
2995 		/*
2996 		 * If random memory allocation policy set already,
2997 		 * don't bother reapplying it.
2998 		 */
2999 		if (already_set && !LGRP_MEM_POLICY_REAPPLICABLE(policy))
3000 			return (0);
3001 
3002 		/*
3003 		 * Mark any existing pages in the given range for
3004 		 * migration, flushing the I/O page cache, and using
3005 		 * underlying segment to calculate anon index and get
3006 		 * anonmap and vnode pointer from
3007 		 */
3008 		if (shmd->shm_softlockcnt > 0)
3009 			segspt_purge(seg);
3010 
3011 		page_mark_migrate(seg, shm_addr, size, amp, 0, NULL, 0, 0);
3012 	}
3013 
3014 	return (0);
3015 }
3016 
3017 /*ARGSUSED*/
3018 void
3019 segspt_shmdump(struct seg *seg)
3020 {
3021 	/* no-op for ISM segment */
3022 }
3023 
3024 /*ARGSUSED*/
3025 static faultcode_t
3026 segspt_shmsetpgsz(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
3027 {
3028 	return (ENOTSUP);
3029 }
3030 
3031 /*
3032  * get a memory ID for an addr in a given segment
3033  */
3034 static int
3035 segspt_shmgetmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
3036 {
3037 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
3038 	struct anon 	*ap;
3039 	size_t		anon_index;
3040 	struct anon_map	*amp = shmd->shm_amp;
3041 	struct spt_data	*sptd = shmd->shm_sptseg->s_data;
3042 	struct seg	*sptseg = shmd->shm_sptseg;
3043 	anon_sync_obj_t	cookie;
3044 
3045 	anon_index = seg_page(seg, addr);
3046 
3047 	if (addr > (seg->s_base + sptd->spt_realsize)) {
3048 		return (EFAULT);
3049 	}
3050 
3051 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
3052 	anon_array_enter(amp, anon_index, &cookie);
3053 	ap = anon_get_ptr(amp->ahp, anon_index);
3054 	if (ap == NULL) {
3055 		struct page *pp;
3056 		caddr_t spt_addr = sptseg->s_base + ptob(anon_index);
3057 
3058 		pp = anon_zero(sptseg, spt_addr, &ap, kcred);
3059 		if (pp == NULL) {
3060 			anon_array_exit(&cookie);
3061 			ANON_LOCK_EXIT(&amp->a_rwlock);
3062 			return (ENOMEM);
3063 		}
3064 		(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
3065 		page_unlock(pp);
3066 	}
3067 	anon_array_exit(&cookie);
3068 	ANON_LOCK_EXIT(&amp->a_rwlock);
3069 	memidp->val[0] = (uintptr_t)ap;
3070 	memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
3071 	return (0);
3072 }
3073 
3074 /*
3075  * Get memory allocation policy info for specified address in given segment
3076  */
3077 static lgrp_mem_policy_info_t *
3078 segspt_shmgetpolicy(struct seg *seg, caddr_t addr)
3079 {
3080 	struct anon_map		*amp;
3081 	ulong_t			anon_index;
3082 	lgrp_mem_policy_info_t	*policy_info;
3083 	struct shm_data		*shm_data;
3084 
3085 	ASSERT(seg != NULL);
3086 
3087 	/*
3088 	 * Get anon_map from segshm
3089 	 *
3090 	 * Assume that no lock needs to be held on anon_map, since
3091 	 * it should be protected by its reference count which must be
3092 	 * nonzero for an existing segment
3093 	 * Need to grab readers lock on policy tree though
3094 	 */
3095 	shm_data = (struct shm_data *)seg->s_data;
3096 	if (shm_data == NULL)
3097 		return (NULL);
3098 	amp = shm_data->shm_amp;
3099 	ASSERT(amp->refcnt != 0);
3100 
3101 	/*
3102 	 * Get policy info
3103 	 *
3104 	 * Assume starting anon index of 0
3105 	 */
3106 	anon_index = seg_page(seg, addr);
3107 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
3108 
3109 	return (policy_info);
3110 }
3111 
3112 /*ARGSUSED*/
3113 static int
3114 segspt_shmcapable(struct seg *seg, segcapability_t capability)
3115 {
3116 	return (0);
3117 }
3118