xref: /titanic_41/usr/src/uts/common/vm/seg_spt.c (revision ba7b222e36bac28710a7f43739283302b617e7f5)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
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 };
114 
115 static int segspt_shmdup(struct seg *seg, struct seg *newseg);
116 static int segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize);
117 static void segspt_shmfree(struct seg *seg);
118 static faultcode_t segspt_shmfault(struct hat *hat, struct seg *seg,
119 		caddr_t addr, size_t len, enum fault_type type, enum seg_rw rw);
120 static faultcode_t segspt_shmfaulta(struct seg *seg, caddr_t addr);
121 static int segspt_shmsetprot(register struct seg *seg, register caddr_t addr,
122 			register size_t len, register uint_t prot);
123 static int segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size,
124 			uint_t prot);
125 static int	segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta);
126 static size_t	segspt_shmswapout(struct seg *seg);
127 static size_t segspt_shmincore(struct seg *seg, caddr_t addr, size_t len,
128 			register char *vec);
129 static int segspt_shmsync(struct seg *seg, register caddr_t addr, size_t len,
130 			int attr, uint_t flags);
131 static int segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
132 			int attr, int op, ulong_t *lockmap, size_t pos);
133 static int segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len,
134 			uint_t *protv);
135 static u_offset_t segspt_shmgetoffset(struct seg *seg, caddr_t addr);
136 static int segspt_shmgettype(struct seg *seg, caddr_t addr);
137 static int segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp);
138 static int segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len,
139 			uint_t behav);
140 static void segspt_shmdump(struct seg *seg);
141 static int segspt_shmpagelock(struct seg *, caddr_t, size_t,
142 			struct page ***, enum lock_type, enum seg_rw);
143 static int segspt_shmsetpgsz(struct seg *, caddr_t, size_t, uint_t);
144 static int segspt_shmgetmemid(struct seg *, caddr_t, memid_t *);
145 static lgrp_mem_policy_info_t *segspt_shmgetpolicy(struct seg *, caddr_t);
146 static int segspt_shmcapable(struct seg *, segcapability_t);
147 
148 struct seg_ops segspt_shmops = {
149 	segspt_shmdup,
150 	segspt_shmunmap,
151 	segspt_shmfree,
152 	segspt_shmfault,
153 	segspt_shmfaulta,
154 	segspt_shmsetprot,
155 	segspt_shmcheckprot,
156 	segspt_shmkluster,
157 	segspt_shmswapout,
158 	segspt_shmsync,
159 	segspt_shmincore,
160 	segspt_shmlockop,
161 	segspt_shmgetprot,
162 	segspt_shmgetoffset,
163 	segspt_shmgettype,
164 	segspt_shmgetvp,
165 	segspt_shmadvise,	/* advise */
166 	segspt_shmdump,
167 	segspt_shmpagelock,
168 	segspt_shmsetpgsz,
169 	segspt_shmgetmemid,
170 	segspt_shmgetpolicy,
171 	segspt_shmcapable,
172 };
173 
174 static void segspt_purge(struct seg *seg);
175 static int segspt_reclaim(void *, caddr_t, size_t, struct page **,
176 		enum seg_rw, int);
177 static int spt_anon_getpages(struct seg *seg, caddr_t addr, size_t len,
178 		page_t **ppa);
179 
180 
181 
182 /*ARGSUSED*/
183 int
184 sptcreate(size_t size, struct seg **sptseg, struct anon_map *amp,
185 	uint_t prot, uint_t flags, uint_t share_szc)
186 {
187 	int 	err;
188 	struct  as	*newas;
189 	struct	segspt_crargs sptcargs;
190 
191 #ifdef DEBUG
192 	TNF_PROBE_1(sptcreate, "spt", /* CSTYLED */,
193 			tnf_ulong, size, size );
194 #endif
195 	if (segspt_minfree == 0)	/* leave min 5% of availrmem for */
196 		segspt_minfree = availrmem/20;	/* for the system */
197 
198 	if (!hat_supported(HAT_SHARED_PT, (void *)0))
199 		return (EINVAL);
200 
201 	/*
202 	 * get a new as for this shared memory segment
203 	 */
204 	newas = as_alloc();
205 	newas->a_proc = NULL;
206 	sptcargs.amp = amp;
207 	sptcargs.prot = prot;
208 	sptcargs.flags = flags;
209 	sptcargs.szc = share_szc;
210 	/*
211 	 * create a shared page table (spt) segment
212 	 */
213 
214 	if (err = as_map(newas, SEGSPTADDR, size, segspt_create, &sptcargs)) {
215 		as_free(newas);
216 		return (err);
217 	}
218 	*sptseg = sptcargs.seg_spt;
219 	return (0);
220 }
221 
222 void
223 sptdestroy(struct as *as, struct anon_map *amp)
224 {
225 
226 #ifdef DEBUG
227 	TNF_PROBE_0(sptdestroy, "spt", /* CSTYLED */);
228 #endif
229 	(void) as_unmap(as, SEGSPTADDR, amp->size);
230 	as_free(as);
231 }
232 
233 /*
234  * called from seg_free().
235  * free (i.e., unlock, unmap, return to free list)
236  *  all the pages in the given seg.
237  */
238 void
239 segspt_free(struct seg	*seg)
240 {
241 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
242 
243 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
244 
245 	if (sptd != NULL) {
246 		if (sptd->spt_realsize)
247 			segspt_free_pages(seg, seg->s_base, sptd->spt_realsize);
248 
249 	if (sptd->spt_ppa_lckcnt)
250 		kmem_free(sptd->spt_ppa_lckcnt,
251 		    sizeof (*sptd->spt_ppa_lckcnt)
252 		    * btopr(sptd->spt_amp->size));
253 		kmem_free(sptd->spt_vp, sizeof (*sptd->spt_vp));
254 		cv_destroy(&sptd->spt_cv);
255 		mutex_destroy(&sptd->spt_lock);
256 		kmem_free(sptd, sizeof (*sptd));
257 	}
258 }
259 
260 /*ARGSUSED*/
261 static int
262 segspt_shmsync(struct seg *seg, caddr_t addr, size_t len, int attr,
263 	uint_t flags)
264 {
265 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
266 
267 	return (0);
268 }
269 
270 /*ARGSUSED*/
271 static size_t
272 segspt_shmincore(struct seg *seg, caddr_t addr, size_t len, char *vec)
273 {
274 	caddr_t	eo_seg;
275 	pgcnt_t	npages;
276 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
277 	struct seg	*sptseg;
278 	struct spt_data *sptd;
279 
280 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
281 #ifdef lint
282 	seg = seg;
283 #endif
284 	sptseg = shmd->shm_sptseg;
285 	sptd = sptseg->s_data;
286 
287 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
288 		eo_seg = addr + len;
289 		while (addr < eo_seg) {
290 			/* page exists, and it's locked. */
291 			*vec++ = SEG_PAGE_INCORE | SEG_PAGE_LOCKED |
292 			    SEG_PAGE_ANON;
293 			addr += PAGESIZE;
294 		}
295 		return (len);
296 	} else {
297 		struct  anon_map *amp = shmd->shm_amp;
298 		struct  anon	*ap;
299 		page_t		*pp;
300 		pgcnt_t 	anon_index;
301 		struct vnode 	*vp;
302 		u_offset_t 	off;
303 		ulong_t		i;
304 		int		ret;
305 		anon_sync_obj_t	cookie;
306 
307 		addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
308 		anon_index = seg_page(seg, addr);
309 		npages = btopr(len);
310 		if (anon_index + npages > btopr(shmd->shm_amp->size)) {
311 			return (EINVAL);
312 		}
313 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
314 		for (i = 0; i < npages; i++, anon_index++) {
315 			ret = 0;
316 			anon_array_enter(amp, anon_index, &cookie);
317 			ap = anon_get_ptr(amp->ahp, anon_index);
318 			if (ap != NULL) {
319 				swap_xlate(ap, &vp, &off);
320 				anon_array_exit(&cookie);
321 				pp = page_lookup_nowait(vp, off, SE_SHARED);
322 				if (pp != NULL) {
323 					ret |= SEG_PAGE_INCORE | SEG_PAGE_ANON;
324 					page_unlock(pp);
325 				}
326 			} else {
327 				anon_array_exit(&cookie);
328 			}
329 			if (shmd->shm_vpage[anon_index] & DISM_PG_LOCKED) {
330 				ret |= SEG_PAGE_LOCKED;
331 			}
332 			*vec++ = (char)ret;
333 		}
334 		ANON_LOCK_EXIT(&amp->a_rwlock);
335 		return (len);
336 	}
337 }
338 
339 static int
340 segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize)
341 {
342 	size_t share_size;
343 
344 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
345 
346 	/*
347 	 * seg.s_size may have been rounded up to the largest page size
348 	 * in shmat().
349 	 * XXX This should be cleanedup. sptdestroy should take a length
350 	 * argument which should be the same as sptcreate. Then
351 	 * this rounding would not be needed (or is done in shm.c)
352 	 * Only the check for full segment will be needed.
353 	 *
354 	 * XXX -- shouldn't raddr == 0 always? These tests don't seem
355 	 * to be useful at all.
356 	 */
357 	share_size = page_get_pagesize(seg->s_szc);
358 	ssize = P2ROUNDUP(ssize, share_size);
359 
360 	if (raddr == seg->s_base && ssize == seg->s_size) {
361 		seg_free(seg);
362 		return (0);
363 	} else
364 		return (EINVAL);
365 }
366 
367 int
368 segspt_create(struct seg *seg, caddr_t argsp)
369 {
370 	int		err;
371 	caddr_t		addr = seg->s_base;
372 	struct spt_data *sptd;
373 	struct 	segspt_crargs *sptcargs = (struct segspt_crargs *)argsp;
374 	struct anon_map *amp = sptcargs->amp;
375 	struct kshmid	*sp = amp->a_sp;
376 	struct	cred	*cred = CRED();
377 	ulong_t		i, j, anon_index = 0;
378 	pgcnt_t		npages = btopr(amp->size);
379 	struct vnode	*vp;
380 	page_t		**ppa;
381 	uint_t		hat_flags;
382 	size_t		pgsz;
383 	pgcnt_t		pgcnt;
384 	caddr_t		a;
385 	pgcnt_t		pidx;
386 	size_t		sz;
387 	proc_t		*procp = curproc;
388 	rctl_qty_t	lockedbytes = 0;
389 	kproject_t	*proj;
390 
391 	/*
392 	 * We are holding the a_lock on the underlying dummy as,
393 	 * so we can make calls to the HAT layer.
394 	 */
395 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
396 	ASSERT(sp != NULL);
397 
398 #ifdef DEBUG
399 	TNF_PROBE_2(segspt_create, "spt", /* CSTYLED */,
400 	    tnf_opaque, addr, addr, tnf_ulong, len, seg->s_size);
401 #endif
402 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
403 		if (err = anon_swap_adjust(npages))
404 			return (err);
405 	}
406 	err = ENOMEM;
407 
408 	if ((sptd = kmem_zalloc(sizeof (*sptd), KM_NOSLEEP)) == NULL)
409 		goto out1;
410 
411 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
412 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * npages),
413 		    KM_NOSLEEP)) == NULL)
414 			goto out2;
415 	}
416 
417 	mutex_init(&sptd->spt_lock, NULL, MUTEX_DEFAULT, NULL);
418 
419 	if ((vp = kmem_zalloc(sizeof (*vp), KM_NOSLEEP)) == NULL)
420 		goto out3;
421 
422 	seg->s_ops = &segspt_ops;
423 	sptd->spt_vp = vp;
424 	sptd->spt_amp = amp;
425 	sptd->spt_prot = sptcargs->prot;
426 	sptd->spt_flags = sptcargs->flags;
427 	seg->s_data = (caddr_t)sptd;
428 	sptd->spt_ppa = NULL;
429 	sptd->spt_ppa_lckcnt = NULL;
430 	seg->s_szc = sptcargs->szc;
431 	cv_init(&sptd->spt_cv, NULL, CV_DEFAULT, NULL);
432 	sptd->spt_gen = 0;
433 
434 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
435 	if (seg->s_szc > amp->a_szc) {
436 		amp->a_szc = seg->s_szc;
437 	}
438 	ANON_LOCK_EXIT(&amp->a_rwlock);
439 
440 	/*
441 	 * Set policy to affect initial allocation of pages in
442 	 * anon_map_createpages()
443 	 */
444 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, amp, anon_index,
445 	    NULL, 0, ptob(npages));
446 
447 	if (sptcargs->flags & SHM_PAGEABLE) {
448 		size_t  share_sz;
449 		pgcnt_t new_npgs, more_pgs;
450 		struct anon_hdr *nahp;
451 		zone_t *zone;
452 
453 		share_sz = page_get_pagesize(seg->s_szc);
454 		if (!IS_P2ALIGNED(amp->size, share_sz)) {
455 			/*
456 			 * We are rounding up the size of the anon array
457 			 * on 4 M boundary because we always create 4 M
458 			 * of page(s) when locking, faulting pages and we
459 			 * don't have to check for all corner cases e.g.
460 			 * if there is enough space to allocate 4 M
461 			 * page.
462 			 */
463 			new_npgs = btop(P2ROUNDUP(amp->size, share_sz));
464 			more_pgs = new_npgs - npages;
465 
466 			/*
467 			 * The zone will never be NULL, as a fully created
468 			 * shm always has an owning zone.
469 			 */
470 			zone = sp->shm_perm.ipc_zone;
471 			ASSERT(zone != NULL);
472 			if (anon_resv_zone(ptob(more_pgs), zone) == 0) {
473 				err = ENOMEM;
474 				goto out4;
475 			}
476 
477 			nahp = anon_create(new_npgs, ANON_SLEEP);
478 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
479 			(void) anon_copy_ptr(amp->ahp, 0, nahp, 0, npages,
480 			    ANON_SLEEP);
481 			anon_release(amp->ahp, npages);
482 			amp->ahp = nahp;
483 			ASSERT(amp->swresv == ptob(npages));
484 			amp->swresv = amp->size = ptob(new_npgs);
485 			ANON_LOCK_EXIT(&amp->a_rwlock);
486 			npages = new_npgs;
487 		}
488 
489 		sptd->spt_ppa_lckcnt = kmem_zalloc(npages *
490 		    sizeof (*sptd->spt_ppa_lckcnt), KM_SLEEP);
491 		sptd->spt_pcachecnt = 0;
492 		sptd->spt_realsize = ptob(npages);
493 		sptcargs->seg_spt = seg;
494 		return (0);
495 	}
496 
497 	/*
498 	 * get array of pages for each anon slot in amp
499 	 */
500 	if ((err = anon_map_createpages(amp, anon_index, ptob(npages), ppa,
501 	    seg, addr, S_CREATE, cred)) != 0)
502 		goto out4;
503 
504 	mutex_enter(&sp->shm_mlock);
505 
506 	/* May be partially locked, so, count bytes to charge for locking */
507 	for (i = 0; i < npages; i++)
508 		if (ppa[i]->p_lckcnt == 0)
509 			lockedbytes += PAGESIZE;
510 
511 	proj = sp->shm_perm.ipc_proj;
512 
513 	if (lockedbytes > 0) {
514 		mutex_enter(&procp->p_lock);
515 		if (rctl_incr_locked_mem(procp, proj, lockedbytes, 0)) {
516 			mutex_exit(&procp->p_lock);
517 			mutex_exit(&sp->shm_mlock);
518 			for (i = 0; i < npages; i++)
519 				page_unlock(ppa[i]);
520 			err = ENOMEM;
521 			goto out4;
522 		}
523 		mutex_exit(&procp->p_lock);
524 	}
525 
526 	/*
527 	 * addr is initial address corresponding to the first page on ppa list
528 	 */
529 	for (i = 0; i < npages; i++) {
530 		/* attempt to lock all pages */
531 		if (page_pp_lock(ppa[i], 0, 1) == 0) {
532 			/*
533 			 * if unable to lock any page, unlock all
534 			 * of them and return error
535 			 */
536 			for (j = 0; j < i; j++)
537 				page_pp_unlock(ppa[j], 0, 1);
538 			for (i = 0; i < npages; i++)
539 				page_unlock(ppa[i]);
540 			rctl_decr_locked_mem(NULL, proj, lockedbytes, 0);
541 			mutex_exit(&sp->shm_mlock);
542 			err = ENOMEM;
543 			goto out4;
544 		}
545 	}
546 	mutex_exit(&sp->shm_mlock);
547 
548 	/*
549 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
550 	 * for the entire life of the segment. For example platforms
551 	 * that do not support Dynamic Reconfiguration.
552 	 */
553 	hat_flags = HAT_LOAD_SHARE;
554 	if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, NULL))
555 		hat_flags |= HAT_LOAD_LOCK;
556 
557 	/*
558 	 * Load translations one lare page at a time
559 	 * to make sure we don't create mappings bigger than
560 	 * segment's size code in case underlying pages
561 	 * are shared with segvn's segment that uses bigger
562 	 * size code than we do.
563 	 */
564 	pgsz = page_get_pagesize(seg->s_szc);
565 	pgcnt = page_get_pagecnt(seg->s_szc);
566 	for (a = addr, pidx = 0; pidx < npages; a += pgsz, pidx += pgcnt) {
567 		sz = MIN(pgsz, ptob(npages - pidx));
568 		hat_memload_array(seg->s_as->a_hat, a, sz,
569 		    &ppa[pidx], sptd->spt_prot, hat_flags);
570 	}
571 
572 	/*
573 	 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
574 	 * we will leave the pages locked SE_SHARED for the life
575 	 * of the ISM segment. This will prevent any calls to
576 	 * hat_pageunload() on this ISM segment for those platforms.
577 	 */
578 	if (!(hat_flags & HAT_LOAD_LOCK)) {
579 		/*
580 		 * On platforms that support HAT_DYNAMIC_ISM_UNMAP,
581 		 * we no longer need to hold the SE_SHARED lock on the pages,
582 		 * since L_PAGELOCK and F_SOFTLOCK calls will grab the
583 		 * SE_SHARED lock on the pages as necessary.
584 		 */
585 		for (i = 0; i < npages; i++)
586 			page_unlock(ppa[i]);
587 	}
588 	sptd->spt_pcachecnt = 0;
589 	kmem_free(ppa, ((sizeof (page_t *)) * npages));
590 	sptd->spt_realsize = ptob(npages);
591 	atomic_add_long(&spt_used, npages);
592 	sptcargs->seg_spt = seg;
593 	return (0);
594 
595 out4:
596 	seg->s_data = NULL;
597 	kmem_free(vp, sizeof (*vp));
598 	cv_destroy(&sptd->spt_cv);
599 out3:
600 	mutex_destroy(&sptd->spt_lock);
601 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
602 		kmem_free(ppa, (sizeof (*ppa) * npages));
603 out2:
604 	kmem_free(sptd, sizeof (*sptd));
605 out1:
606 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
607 		anon_swap_restore(npages);
608 	return (err);
609 }
610 
611 /*ARGSUSED*/
612 void
613 segspt_free_pages(struct seg *seg, caddr_t addr, size_t len)
614 {
615 	struct page 	*pp;
616 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
617 	pgcnt_t		npages;
618 	ulong_t		anon_idx;
619 	struct anon_map *amp;
620 	struct anon 	*ap;
621 	struct vnode 	*vp;
622 	u_offset_t 	off;
623 	uint_t		hat_flags;
624 	int		root = 0;
625 	pgcnt_t		pgs, curnpgs = 0;
626 	page_t		*rootpp;
627 	rctl_qty_t	unlocked_bytes = 0;
628 	kproject_t	*proj;
629 	kshmid_t	*sp;
630 
631 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
632 
633 	len = P2ROUNDUP(len, PAGESIZE);
634 
635 	npages = btop(len);
636 
637 	hat_flags = HAT_UNLOAD_UNLOCK | HAT_UNLOAD_UNMAP;
638 	if ((hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) ||
639 	    (sptd->spt_flags & SHM_PAGEABLE)) {
640 		hat_flags = HAT_UNLOAD_UNMAP;
641 	}
642 
643 	hat_unload(seg->s_as->a_hat, addr, len, hat_flags);
644 
645 	amp = sptd->spt_amp;
646 	if (sptd->spt_flags & SHM_PAGEABLE)
647 		npages = btop(amp->size);
648 
649 	ASSERT(amp != NULL);
650 
651 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
652 		sp = amp->a_sp;
653 		proj = sp->shm_perm.ipc_proj;
654 		mutex_enter(&sp->shm_mlock);
655 	}
656 	for (anon_idx = 0; anon_idx < npages; anon_idx++) {
657 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
658 			if ((ap = anon_get_ptr(amp->ahp, anon_idx)) == NULL) {
659 				panic("segspt_free_pages: null app");
660 				/*NOTREACHED*/
661 			}
662 		} else {
663 			if ((ap = anon_get_next_ptr(amp->ahp, &anon_idx))
664 			    == NULL)
665 				continue;
666 		}
667 		ASSERT(ANON_ISBUSY(anon_get_slot(amp->ahp, anon_idx)) == 0);
668 		swap_xlate(ap, &vp, &off);
669 
670 		/*
671 		 * If this platform supports HAT_DYNAMIC_ISM_UNMAP,
672 		 * the pages won't be having SE_SHARED lock at this
673 		 * point.
674 		 *
675 		 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
676 		 * the pages are still held SE_SHARED locked from the
677 		 * original segspt_create()
678 		 *
679 		 * Our goal is to get SE_EXCL lock on each page, remove
680 		 * permanent lock on it and invalidate the page.
681 		 */
682 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
683 			if (hat_flags == HAT_UNLOAD_UNMAP)
684 				pp = page_lookup(vp, off, SE_EXCL);
685 			else {
686 				if ((pp = page_find(vp, off)) == NULL) {
687 					panic("segspt_free_pages: "
688 					    "page not locked");
689 					/*NOTREACHED*/
690 				}
691 				if (!page_tryupgrade(pp)) {
692 					page_unlock(pp);
693 					pp = page_lookup(vp, off, SE_EXCL);
694 				}
695 			}
696 			if (pp == NULL) {
697 				panic("segspt_free_pages: "
698 				    "page not in the system");
699 				/*NOTREACHED*/
700 			}
701 			ASSERT(pp->p_lckcnt > 0);
702 			page_pp_unlock(pp, 0, 1);
703 			if (pp->p_lckcnt == 0)
704 				unlocked_bytes += PAGESIZE;
705 		} else {
706 			if ((pp = page_lookup(vp, off, SE_EXCL)) == NULL)
707 				continue;
708 		}
709 		/*
710 		 * It's logical to invalidate the pages here as in most cases
711 		 * these were created by segspt.
712 		 */
713 		if (pp->p_szc != 0) {
714 			if (root == 0) {
715 				ASSERT(curnpgs == 0);
716 				root = 1;
717 				rootpp = pp;
718 				pgs = curnpgs = page_get_pagecnt(pp->p_szc);
719 				ASSERT(pgs > 1);
720 				ASSERT(IS_P2ALIGNED(pgs, pgs));
721 				ASSERT(!(page_pptonum(pp) & (pgs - 1)));
722 				curnpgs--;
723 			} else if ((page_pptonum(pp) & (pgs - 1)) == pgs - 1) {
724 				ASSERT(curnpgs == 1);
725 				ASSERT(page_pptonum(pp) ==
726 				    page_pptonum(rootpp) + (pgs - 1));
727 				page_destroy_pages(rootpp);
728 				root = 0;
729 				curnpgs = 0;
730 			} else {
731 				ASSERT(curnpgs > 1);
732 				ASSERT(page_pptonum(pp) ==
733 				    page_pptonum(rootpp) + (pgs - curnpgs));
734 				curnpgs--;
735 			}
736 		} else {
737 			if (root != 0 || curnpgs != 0) {
738 				panic("segspt_free_pages: bad large page");
739 				/*NOTREACHED*/
740 			}
741 			/*
742 			 * Before destroying the pages, we need to take care
743 			 * of the rctl locked memory accounting. For that
744 			 * we need to calculte the unlocked_bytes.
745 			 */
746 			if (pp->p_lckcnt > 0)
747 				unlocked_bytes += PAGESIZE;
748 			/*LINTED: constant in conditional context */
749 			VN_DISPOSE(pp, B_INVAL, 0, kcred);
750 		}
751 	}
752 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
753 		if (unlocked_bytes > 0)
754 			rctl_decr_locked_mem(NULL, proj, unlocked_bytes, 0);
755 		mutex_exit(&sp->shm_mlock);
756 	}
757 	if (root != 0 || curnpgs != 0) {
758 		panic("segspt_free_pages: bad large page");
759 		/*NOTREACHED*/
760 	}
761 
762 	/*
763 	 * mark that pages have been released
764 	 */
765 	sptd->spt_realsize = 0;
766 
767 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
768 		atomic_add_long(&spt_used, -npages);
769 		anon_swap_restore(npages);
770 	}
771 }
772 
773 /*
774  * Get memory allocation policy info for specified address in given segment
775  */
776 static lgrp_mem_policy_info_t *
777 segspt_getpolicy(struct seg *seg, caddr_t addr)
778 {
779 	struct anon_map		*amp;
780 	ulong_t			anon_index;
781 	lgrp_mem_policy_info_t	*policy_info;
782 	struct spt_data		*spt_data;
783 
784 	ASSERT(seg != NULL);
785 
786 	/*
787 	 * Get anon_map from segspt
788 	 *
789 	 * Assume that no lock needs to be held on anon_map, since
790 	 * it should be protected by its reference count which must be
791 	 * nonzero for an existing segment
792 	 * Need to grab readers lock on policy tree though
793 	 */
794 	spt_data = (struct spt_data *)seg->s_data;
795 	if (spt_data == NULL)
796 		return (NULL);
797 	amp = spt_data->spt_amp;
798 	ASSERT(amp->refcnt != 0);
799 
800 	/*
801 	 * Get policy info
802 	 *
803 	 * Assume starting anon index of 0
804 	 */
805 	anon_index = seg_page(seg, addr);
806 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
807 
808 	return (policy_info);
809 }
810 
811 /*
812  * DISM only.
813  * Return locked pages over a given range.
814  *
815  * We will cache all DISM locked pages and save the pplist for the
816  * entire segment in the ppa field of the underlying DISM segment structure.
817  * Later, during a call to segspt_reclaim() we will use this ppa array
818  * to page_unlock() all of the pages and then we will free this ppa list.
819  */
820 /*ARGSUSED*/
821 static int
822 segspt_dismpagelock(struct seg *seg, caddr_t addr, size_t len,
823     struct page ***ppp, enum lock_type type, enum seg_rw rw)
824 {
825 	struct  shm_data *shmd = (struct shm_data *)seg->s_data;
826 	struct  seg	*sptseg = shmd->shm_sptseg;
827 	struct  spt_data *sptd = sptseg->s_data;
828 	pgcnt_t pg_idx, npages, tot_npages, npgs;
829 	struct  page **pplist, **pl, **ppa, *pp;
830 	struct  anon_map *amp;
831 	spgcnt_t	an_idx;
832 	int 	ret = ENOTSUP;
833 	uint_t	pl_built = 0;
834 	struct  anon *ap;
835 	struct  vnode *vp;
836 	u_offset_t off;
837 	pgcnt_t claim_availrmem = 0;
838 	uint_t	szc;
839 
840 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
841 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
842 
843 	/*
844 	 * We want to lock/unlock the entire ISM segment. Therefore,
845 	 * we will be using the underlying sptseg and it's base address
846 	 * and length for the caching arguments.
847 	 */
848 	ASSERT(sptseg);
849 	ASSERT(sptd);
850 
851 	pg_idx = seg_page(seg, addr);
852 	npages = btopr(len);
853 
854 	/*
855 	 * check if the request is larger than number of pages covered
856 	 * by amp
857 	 */
858 	if (pg_idx + npages > btopr(sptd->spt_amp->size)) {
859 		*ppp = NULL;
860 		return (ENOTSUP);
861 	}
862 
863 	if (type == L_PAGEUNLOCK) {
864 		ASSERT(sptd->spt_ppa != NULL);
865 
866 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
867 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
868 
869 		/*
870 		 * If someone is blocked while unmapping, we purge
871 		 * segment page cache and thus reclaim pplist synchronously
872 		 * without waiting for seg_pasync_thread. This speeds up
873 		 * unmapping in cases where munmap(2) is called, while
874 		 * raw async i/o is still in progress or where a thread
875 		 * exits on data fault in a multithreaded application.
876 		 */
877 		if ((sptd->spt_flags & DISM_PPA_CHANGED) ||
878 		    (AS_ISUNMAPWAIT(seg->s_as) &&
879 		    shmd->shm_softlockcnt > 0)) {
880 			segspt_purge(seg);
881 		}
882 		return (0);
883 	}
884 
885 	/* The L_PAGELOCK case ... */
886 
887 	if (sptd->spt_flags & DISM_PPA_CHANGED) {
888 		segspt_purge(seg);
889 		/*
890 		 * for DISM ppa needs to be rebuild since
891 		 * number of locked pages could be changed
892 		 */
893 		*ppp = NULL;
894 		return (ENOTSUP);
895 	}
896 
897 	/*
898 	 * First try to find pages in segment page cache, without
899 	 * holding the segment lock.
900 	 */
901 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
902 	    S_WRITE, SEGP_FORCE_WIRED);
903 	if (pplist != NULL) {
904 		ASSERT(sptd->spt_ppa != NULL);
905 		ASSERT(sptd->spt_ppa == pplist);
906 		ppa = sptd->spt_ppa;
907 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
908 			if (ppa[an_idx] == NULL) {
909 				seg_pinactive(seg, NULL, seg->s_base,
910 				    sptd->spt_amp->size, ppa,
911 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
912 				*ppp = NULL;
913 				return (ENOTSUP);
914 			}
915 			if ((szc = ppa[an_idx]->p_szc) != 0) {
916 				npgs = page_get_pagecnt(szc);
917 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
918 			} else {
919 				an_idx++;
920 			}
921 		}
922 		/*
923 		 * Since we cache the entire DISM segment, we want to
924 		 * set ppp to point to the first slot that corresponds
925 		 * to the requested addr, i.e. pg_idx.
926 		 */
927 		*ppp = &(sptd->spt_ppa[pg_idx]);
928 		return (0);
929 	}
930 
931 	mutex_enter(&sptd->spt_lock);
932 	/*
933 	 * try to find pages in segment page cache with mutex
934 	 */
935 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
936 	    S_WRITE, SEGP_FORCE_WIRED);
937 	if (pplist != NULL) {
938 		ASSERT(sptd->spt_ppa != NULL);
939 		ASSERT(sptd->spt_ppa == pplist);
940 		ppa = sptd->spt_ppa;
941 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
942 			if (ppa[an_idx] == NULL) {
943 				mutex_exit(&sptd->spt_lock);
944 				seg_pinactive(seg, NULL, seg->s_base,
945 				    sptd->spt_amp->size, ppa,
946 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
947 				*ppp = NULL;
948 				return (ENOTSUP);
949 			}
950 			if ((szc = ppa[an_idx]->p_szc) != 0) {
951 				npgs = page_get_pagecnt(szc);
952 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
953 			} else {
954 				an_idx++;
955 			}
956 		}
957 		/*
958 		 * Since we cache the entire DISM segment, we want to
959 		 * set ppp to point to the first slot that corresponds
960 		 * to the requested addr, i.e. pg_idx.
961 		 */
962 		mutex_exit(&sptd->spt_lock);
963 		*ppp = &(sptd->spt_ppa[pg_idx]);
964 		return (0);
965 	}
966 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
967 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
968 		mutex_exit(&sptd->spt_lock);
969 		*ppp = NULL;
970 		return (ENOTSUP);
971 	}
972 
973 	/*
974 	 * No need to worry about protections because DISM pages are always rw.
975 	 */
976 	pl = pplist = NULL;
977 	amp = sptd->spt_amp;
978 
979 	/*
980 	 * Do we need to build the ppa array?
981 	 */
982 	if (sptd->spt_ppa == NULL) {
983 		pgcnt_t lpg_cnt = 0;
984 
985 		pl_built = 1;
986 		tot_npages = btopr(sptd->spt_amp->size);
987 
988 		ASSERT(sptd->spt_pcachecnt == 0);
989 		pplist = kmem_zalloc(sizeof (page_t *) * tot_npages, KM_SLEEP);
990 		pl = pplist;
991 
992 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
993 		for (an_idx = 0; an_idx < tot_npages; ) {
994 			ap = anon_get_ptr(amp->ahp, an_idx);
995 			/*
996 			 * Cache only mlocked pages. For large pages
997 			 * if one (constituent) page is mlocked
998 			 * all pages for that large page
999 			 * are cached also. This is for quick
1000 			 * lookups of ppa array;
1001 			 */
1002 			if ((ap != NULL) && (lpg_cnt != 0 ||
1003 			    (sptd->spt_ppa_lckcnt[an_idx] != 0))) {
1004 
1005 				swap_xlate(ap, &vp, &off);
1006 				pp = page_lookup(vp, off, SE_SHARED);
1007 				ASSERT(pp != NULL);
1008 				if (lpg_cnt == 0) {
1009 					lpg_cnt++;
1010 					/*
1011 					 * For a small page, we are done --
1012 					 * lpg_count is reset to 0 below.
1013 					 *
1014 					 * For a large page, we are guaranteed
1015 					 * to find the anon structures of all
1016 					 * constituent pages and a non-zero
1017 					 * lpg_cnt ensures that we don't test
1018 					 * for mlock for these. We are done
1019 					 * when lpg_count reaches (npgs + 1).
1020 					 * If we are not the first constituent
1021 					 * page, restart at the first one.
1022 					 */
1023 					npgs = page_get_pagecnt(pp->p_szc);
1024 					if (!IS_P2ALIGNED(an_idx, npgs)) {
1025 						an_idx = P2ALIGN(an_idx, npgs);
1026 						page_unlock(pp);
1027 						continue;
1028 					}
1029 				}
1030 				if (++lpg_cnt > npgs)
1031 					lpg_cnt = 0;
1032 
1033 				/*
1034 				 * availrmem is decremented only
1035 				 * for unlocked pages
1036 				 */
1037 				if (sptd->spt_ppa_lckcnt[an_idx] == 0)
1038 					claim_availrmem++;
1039 				pplist[an_idx] = pp;
1040 			}
1041 			an_idx++;
1042 		}
1043 		ANON_LOCK_EXIT(&amp->a_rwlock);
1044 
1045 		if (claim_availrmem) {
1046 			mutex_enter(&freemem_lock);
1047 			if (availrmem < tune.t_minarmem + claim_availrmem) {
1048 				mutex_exit(&freemem_lock);
1049 				ret = ENOTSUP;
1050 				claim_availrmem = 0;
1051 				goto insert_fail;
1052 			} else {
1053 				availrmem -= claim_availrmem;
1054 			}
1055 			mutex_exit(&freemem_lock);
1056 		}
1057 
1058 		sptd->spt_ppa = pl;
1059 	} else {
1060 		/*
1061 		 * We already have a valid ppa[].
1062 		 */
1063 		pl = sptd->spt_ppa;
1064 	}
1065 
1066 	ASSERT(pl != NULL);
1067 
1068 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1069 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1070 	    segspt_reclaim);
1071 	if (ret == SEGP_FAIL) {
1072 		/*
1073 		 * seg_pinsert failed. We return
1074 		 * ENOTSUP, so that the as_pagelock() code will
1075 		 * then try the slower F_SOFTLOCK path.
1076 		 */
1077 		if (pl_built) {
1078 			/*
1079 			 * No one else has referenced the ppa[].
1080 			 * We created it and we need to destroy it.
1081 			 */
1082 			sptd->spt_ppa = NULL;
1083 		}
1084 		ret = ENOTSUP;
1085 		goto insert_fail;
1086 	}
1087 
1088 	/*
1089 	 * In either case, we increment softlockcnt on the 'real' segment.
1090 	 */
1091 	sptd->spt_pcachecnt++;
1092 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), 1);
1093 
1094 	ppa = sptd->spt_ppa;
1095 	for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
1096 		if (ppa[an_idx] == NULL) {
1097 			mutex_exit(&sptd->spt_lock);
1098 			seg_pinactive(seg, NULL, seg->s_base,
1099 			    sptd->spt_amp->size,
1100 			    pl, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1101 			*ppp = NULL;
1102 			return (ENOTSUP);
1103 		}
1104 		if ((szc = ppa[an_idx]->p_szc) != 0) {
1105 			npgs = page_get_pagecnt(szc);
1106 			an_idx = P2ROUNDUP(an_idx + 1, npgs);
1107 		} else {
1108 			an_idx++;
1109 		}
1110 	}
1111 	/*
1112 	 * We can now drop the sptd->spt_lock since the ppa[]
1113 	 * exists and he have incremented pacachecnt.
1114 	 */
1115 	mutex_exit(&sptd->spt_lock);
1116 
1117 	/*
1118 	 * Since we cache the entire segment, we want to
1119 	 * set ppp to point to the first slot that corresponds
1120 	 * to the requested addr, i.e. pg_idx.
1121 	 */
1122 	*ppp = &(sptd->spt_ppa[pg_idx]);
1123 	return (0);
1124 
1125 insert_fail:
1126 	/*
1127 	 * We will only reach this code if we tried and failed.
1128 	 *
1129 	 * And we can drop the lock on the dummy seg, once we've failed
1130 	 * to set up a new ppa[].
1131 	 */
1132 	mutex_exit(&sptd->spt_lock);
1133 
1134 	if (pl_built) {
1135 		if (claim_availrmem) {
1136 			mutex_enter(&freemem_lock);
1137 			availrmem += claim_availrmem;
1138 			mutex_exit(&freemem_lock);
1139 		}
1140 
1141 		/*
1142 		 * We created pl and we need to destroy it.
1143 		 */
1144 		pplist = pl;
1145 		for (an_idx = 0; an_idx < tot_npages; an_idx++) {
1146 			if (pplist[an_idx] != NULL)
1147 				page_unlock(pplist[an_idx]);
1148 		}
1149 		kmem_free(pl, sizeof (page_t *) * tot_npages);
1150 	}
1151 
1152 	if (shmd->shm_softlockcnt <= 0) {
1153 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1154 			mutex_enter(&seg->s_as->a_contents);
1155 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1156 				AS_CLRUNMAPWAIT(seg->s_as);
1157 				cv_broadcast(&seg->s_as->a_cv);
1158 			}
1159 			mutex_exit(&seg->s_as->a_contents);
1160 		}
1161 	}
1162 	*ppp = NULL;
1163 	return (ret);
1164 }
1165 
1166 
1167 
1168 /*
1169  * return locked pages over a given range.
1170  *
1171  * We will cache the entire ISM segment and save the pplist for the
1172  * entire segment in the ppa field of the underlying ISM segment structure.
1173  * Later, during a call to segspt_reclaim() we will use this ppa array
1174  * to page_unlock() all of the pages and then we will free this ppa list.
1175  */
1176 /*ARGSUSED*/
1177 static int
1178 segspt_shmpagelock(struct seg *seg, caddr_t addr, size_t len,
1179     struct page ***ppp, enum lock_type type, enum seg_rw rw)
1180 {
1181 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1182 	struct seg	*sptseg = shmd->shm_sptseg;
1183 	struct spt_data *sptd = sptseg->s_data;
1184 	pgcnt_t np, page_index, npages;
1185 	caddr_t a, spt_base;
1186 	struct page **pplist, **pl, *pp;
1187 	struct anon_map *amp;
1188 	ulong_t anon_index;
1189 	int ret = ENOTSUP;
1190 	uint_t	pl_built = 0;
1191 	struct anon *ap;
1192 	struct vnode *vp;
1193 	u_offset_t off;
1194 
1195 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1196 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
1197 
1198 
1199 	/*
1200 	 * We want to lock/unlock the entire ISM segment. Therefore,
1201 	 * we will be using the underlying sptseg and it's base address
1202 	 * and length for the caching arguments.
1203 	 */
1204 	ASSERT(sptseg);
1205 	ASSERT(sptd);
1206 
1207 	if (sptd->spt_flags & SHM_PAGEABLE) {
1208 		return (segspt_dismpagelock(seg, addr, len, ppp, type, rw));
1209 	}
1210 
1211 	page_index = seg_page(seg, addr);
1212 	npages = btopr(len);
1213 
1214 	/*
1215 	 * check if the request is larger than number of pages covered
1216 	 * by amp
1217 	 */
1218 	if (page_index + npages > btopr(sptd->spt_amp->size)) {
1219 		*ppp = NULL;
1220 		return (ENOTSUP);
1221 	}
1222 
1223 	if (type == L_PAGEUNLOCK) {
1224 
1225 		ASSERT(sptd->spt_ppa != NULL);
1226 
1227 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
1228 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1229 
1230 		/*
1231 		 * If someone is blocked while unmapping, we purge
1232 		 * segment page cache and thus reclaim pplist synchronously
1233 		 * without waiting for seg_pasync_thread. This speeds up
1234 		 * unmapping in cases where munmap(2) is called, while
1235 		 * raw async i/o is still in progress or where a thread
1236 		 * exits on data fault in a multithreaded application.
1237 		 */
1238 		if (AS_ISUNMAPWAIT(seg->s_as) && (shmd->shm_softlockcnt > 0)) {
1239 			segspt_purge(seg);
1240 		}
1241 		return (0);
1242 	}
1243 
1244 	/* The L_PAGELOCK case... */
1245 
1246 	/*
1247 	 * First try to find pages in segment page cache, without
1248 	 * holding the segment lock.
1249 	 */
1250 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1251 	    S_WRITE, SEGP_FORCE_WIRED);
1252 	if (pplist != NULL) {
1253 		ASSERT(sptd->spt_ppa == pplist);
1254 		ASSERT(sptd->spt_ppa[page_index]);
1255 		/*
1256 		 * Since we cache the entire ISM segment, we want to
1257 		 * set ppp to point to the first slot that corresponds
1258 		 * to the requested addr, i.e. page_index.
1259 		 */
1260 		*ppp = &(sptd->spt_ppa[page_index]);
1261 		return (0);
1262 	}
1263 
1264 	mutex_enter(&sptd->spt_lock);
1265 
1266 	/*
1267 	 * try to find pages in segment page cache
1268 	 */
1269 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1270 	    S_WRITE, SEGP_FORCE_WIRED);
1271 	if (pplist != NULL) {
1272 		ASSERT(sptd->spt_ppa == pplist);
1273 		/*
1274 		 * Since we cache the entire segment, we want to
1275 		 * set ppp to point to the first slot that corresponds
1276 		 * to the requested addr, i.e. page_index.
1277 		 */
1278 		mutex_exit(&sptd->spt_lock);
1279 		*ppp = &(sptd->spt_ppa[page_index]);
1280 		return (0);
1281 	}
1282 
1283 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
1284 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
1285 		mutex_exit(&sptd->spt_lock);
1286 		*ppp = NULL;
1287 		return (ENOTSUP);
1288 	}
1289 
1290 	/*
1291 	 * No need to worry about protections because ISM pages
1292 	 * are always rw.
1293 	 */
1294 	pl = pplist = NULL;
1295 
1296 	/*
1297 	 * Do we need to build the ppa array?
1298 	 */
1299 	if (sptd->spt_ppa == NULL) {
1300 		ASSERT(sptd->spt_ppa == pplist);
1301 
1302 		spt_base = sptseg->s_base;
1303 		pl_built = 1;
1304 
1305 		/*
1306 		 * availrmem is decremented once during anon_swap_adjust()
1307 		 * and is incremented during the anon_unresv(), which is
1308 		 * called from shm_rm_amp() when the segment is destroyed.
1309 		 */
1310 		amp = sptd->spt_amp;
1311 		ASSERT(amp != NULL);
1312 
1313 		/* pcachecnt is protected by sptd->spt_lock */
1314 		ASSERT(sptd->spt_pcachecnt == 0);
1315 		pplist = kmem_zalloc(sizeof (page_t *)
1316 		    * btopr(sptd->spt_amp->size), KM_SLEEP);
1317 		pl = pplist;
1318 
1319 		anon_index = seg_page(sptseg, spt_base);
1320 
1321 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1322 		for (a = spt_base; a < (spt_base + sptd->spt_amp->size);
1323 		    a += PAGESIZE, anon_index++, pplist++) {
1324 			ap = anon_get_ptr(amp->ahp, anon_index);
1325 			ASSERT(ap != NULL);
1326 			swap_xlate(ap, &vp, &off);
1327 			pp = page_lookup(vp, off, SE_SHARED);
1328 			ASSERT(pp != NULL);
1329 			*pplist = pp;
1330 		}
1331 		ANON_LOCK_EXIT(&amp->a_rwlock);
1332 
1333 		if (a < (spt_base + sptd->spt_amp->size)) {
1334 			ret = ENOTSUP;
1335 			goto insert_fail;
1336 		}
1337 		sptd->spt_ppa = pl;
1338 	} else {
1339 		/*
1340 		 * We already have a valid ppa[].
1341 		 */
1342 		pl = sptd->spt_ppa;
1343 	}
1344 
1345 	ASSERT(pl != NULL);
1346 
1347 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1348 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1349 	    segspt_reclaim);
1350 	if (ret == SEGP_FAIL) {
1351 		/*
1352 		 * seg_pinsert failed. We return
1353 		 * ENOTSUP, so that the as_pagelock() code will
1354 		 * then try the slower F_SOFTLOCK path.
1355 		 */
1356 		if (pl_built) {
1357 			/*
1358 			 * No one else has referenced the ppa[].
1359 			 * We created it and we need to destroy it.
1360 			 */
1361 			sptd->spt_ppa = NULL;
1362 		}
1363 		ret = ENOTSUP;
1364 		goto insert_fail;
1365 	}
1366 
1367 	/*
1368 	 * In either case, we increment softlockcnt on the 'real' segment.
1369 	 */
1370 	sptd->spt_pcachecnt++;
1371 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), 1);
1372 
1373 	/*
1374 	 * We can now drop the sptd->spt_lock since the ppa[]
1375 	 * exists and he have incremented pacachecnt.
1376 	 */
1377 	mutex_exit(&sptd->spt_lock);
1378 
1379 	/*
1380 	 * Since we cache the entire segment, we want to
1381 	 * set ppp to point to the first slot that corresponds
1382 	 * to the requested addr, i.e. page_index.
1383 	 */
1384 	*ppp = &(sptd->spt_ppa[page_index]);
1385 	return (0);
1386 
1387 insert_fail:
1388 	/*
1389 	 * We will only reach this code if we tried and failed.
1390 	 *
1391 	 * And we can drop the lock on the dummy seg, once we've failed
1392 	 * to set up a new ppa[].
1393 	 */
1394 	mutex_exit(&sptd->spt_lock);
1395 
1396 	if (pl_built) {
1397 		/*
1398 		 * We created pl and we need to destroy it.
1399 		 */
1400 		pplist = pl;
1401 		np = (((uintptr_t)(a - spt_base)) >> PAGESHIFT);
1402 		while (np) {
1403 			page_unlock(*pplist);
1404 			np--;
1405 			pplist++;
1406 		}
1407 		kmem_free(pl, sizeof (page_t *) * btopr(sptd->spt_amp->size));
1408 	}
1409 	if (shmd->shm_softlockcnt <= 0) {
1410 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1411 			mutex_enter(&seg->s_as->a_contents);
1412 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1413 				AS_CLRUNMAPWAIT(seg->s_as);
1414 				cv_broadcast(&seg->s_as->a_cv);
1415 			}
1416 			mutex_exit(&seg->s_as->a_contents);
1417 		}
1418 	}
1419 	*ppp = NULL;
1420 	return (ret);
1421 }
1422 
1423 /*
1424  * purge any cached pages in the I/O page cache
1425  */
1426 static void
1427 segspt_purge(struct seg *seg)
1428 {
1429 	seg_ppurge(seg, NULL, SEGP_FORCE_WIRED);
1430 }
1431 
1432 static int
1433 segspt_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
1434 	enum seg_rw rw, int async)
1435 {
1436 	struct seg *seg = (struct seg *)ptag;
1437 	struct	shm_data *shmd = (struct shm_data *)seg->s_data;
1438 	struct	seg	*sptseg;
1439 	struct	spt_data *sptd;
1440 	pgcnt_t npages, i, free_availrmem = 0;
1441 	int	done = 0;
1442 
1443 #ifdef lint
1444 	addr = addr;
1445 #endif
1446 	sptseg = shmd->shm_sptseg;
1447 	sptd = sptseg->s_data;
1448 	npages = (len >> PAGESHIFT);
1449 	ASSERT(npages);
1450 	ASSERT(sptd->spt_pcachecnt != 0);
1451 	ASSERT(sptd->spt_ppa == pplist);
1452 	ASSERT(npages == btopr(sptd->spt_amp->size));
1453 	ASSERT(async || AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1454 
1455 	/*
1456 	 * Acquire the lock on the dummy seg and destroy the
1457 	 * ppa array IF this is the last pcachecnt.
1458 	 */
1459 	mutex_enter(&sptd->spt_lock);
1460 	if (--sptd->spt_pcachecnt == 0) {
1461 		for (i = 0; i < npages; i++) {
1462 			if (pplist[i] == NULL) {
1463 				continue;
1464 			}
1465 			if (rw == S_WRITE) {
1466 				hat_setrefmod(pplist[i]);
1467 			} else {
1468 				hat_setref(pplist[i]);
1469 			}
1470 			if ((sptd->spt_flags & SHM_PAGEABLE) &&
1471 			    (sptd->spt_ppa_lckcnt[i] == 0))
1472 				free_availrmem++;
1473 			page_unlock(pplist[i]);
1474 		}
1475 		if ((sptd->spt_flags & SHM_PAGEABLE) && free_availrmem) {
1476 			mutex_enter(&freemem_lock);
1477 			availrmem += free_availrmem;
1478 			mutex_exit(&freemem_lock);
1479 		}
1480 		/*
1481 		 * Since we want to cach/uncache the entire ISM segment,
1482 		 * we will track the pplist in a segspt specific field
1483 		 * ppa, that is initialized at the time we add an entry to
1484 		 * the cache.
1485 		 */
1486 		ASSERT(sptd->spt_pcachecnt == 0);
1487 		kmem_free(pplist, sizeof (page_t *) * npages);
1488 		sptd->spt_ppa = NULL;
1489 		sptd->spt_flags &= ~DISM_PPA_CHANGED;
1490 		sptd->spt_gen++;
1491 		cv_broadcast(&sptd->spt_cv);
1492 		done = 1;
1493 	}
1494 	mutex_exit(&sptd->spt_lock);
1495 
1496 	/*
1497 	 * If we are pcache async thread or called via seg_ppurge_wiredpp() we
1498 	 * may not hold AS lock (in this case async argument is not 0). This
1499 	 * means if softlockcnt drops to 0 after the decrement below address
1500 	 * space may get freed. We can't allow it since after softlock
1501 	 * derement to 0 we still need to access as structure for possible
1502 	 * wakeup of unmap waiters. To prevent the disappearance of as we take
1503 	 * this segment's shm_segfree_syncmtx. segspt_shmfree() also takes
1504 	 * this mutex as a barrier to make sure this routine completes before
1505 	 * segment is freed.
1506 	 *
1507 	 * The second complication we have to deal with in async case is a
1508 	 * possibility of missed wake up of unmap wait thread. When we don't
1509 	 * hold as lock here we may take a_contents lock before unmap wait
1510 	 * thread that was first to see softlockcnt was still not 0. As a
1511 	 * result we'll fail to wake up an unmap wait thread. To avoid this
1512 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
1513 	 * to 0 if async is not 0.  unmapwait thread
1514 	 * will not block if this flag is set.
1515 	 */
1516 	if (async)
1517 		mutex_enter(&shmd->shm_segfree_syncmtx);
1518 
1519 	/*
1520 	 * Now decrement softlockcnt.
1521 	 */
1522 	ASSERT(shmd->shm_softlockcnt > 0);
1523 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -1);
1524 
1525 	if (shmd->shm_softlockcnt <= 0) {
1526 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
1527 			mutex_enter(&seg->s_as->a_contents);
1528 			if (async)
1529 				AS_SETNOUNMAPWAIT(seg->s_as);
1530 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1531 				AS_CLRUNMAPWAIT(seg->s_as);
1532 				cv_broadcast(&seg->s_as->a_cv);
1533 			}
1534 			mutex_exit(&seg->s_as->a_contents);
1535 		}
1536 	}
1537 
1538 	if (async)
1539 		mutex_exit(&shmd->shm_segfree_syncmtx);
1540 
1541 	return (done);
1542 }
1543 
1544 /*
1545  * Do a F_SOFTUNLOCK call over the range requested.
1546  * The range must have already been F_SOFTLOCK'ed.
1547  *
1548  * The calls to acquire and release the anon map lock mutex were
1549  * removed in order to avoid a deadly embrace during a DR
1550  * memory delete operation.  (Eg. DR blocks while waiting for a
1551  * exclusive lock on a page that is being used for kaio; the
1552  * thread that will complete the kaio and call segspt_softunlock
1553  * blocks on the anon map lock; another thread holding the anon
1554  * map lock blocks on another page lock via the segspt_shmfault
1555  * -> page_lookup -> page_lookup_create -> page_lock_es code flow.)
1556  *
1557  * The appropriateness of the removal is based upon the following:
1558  * 1. If we are holding a segment's reader lock and the page is held
1559  * shared, then the corresponding element in anonmap which points to
1560  * anon struct cannot change and there is no need to acquire the
1561  * anonymous map lock.
1562  * 2. Threads in segspt_softunlock have a reader lock on the segment
1563  * and already have the shared page lock, so we are guaranteed that
1564  * the anon map slot cannot change and therefore can call anon_get_ptr()
1565  * without grabbing the anonymous map lock.
1566  * 3. Threads that softlock a shared page break copy-on-write, even if
1567  * its a read.  Thus cow faults can be ignored with respect to soft
1568  * unlocking, since the breaking of cow means that the anon slot(s) will
1569  * not be shared.
1570  */
1571 static void
1572 segspt_softunlock(struct seg *seg, caddr_t sptseg_addr,
1573 	size_t len, enum seg_rw rw)
1574 {
1575 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1576 	struct seg	*sptseg;
1577 	struct spt_data *sptd;
1578 	page_t *pp;
1579 	caddr_t adr;
1580 	struct vnode *vp;
1581 	u_offset_t offset;
1582 	ulong_t anon_index;
1583 	struct anon_map *amp;		/* XXX - for locknest */
1584 	struct anon *ap = NULL;
1585 	pgcnt_t npages;
1586 
1587 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1588 
1589 	sptseg = shmd->shm_sptseg;
1590 	sptd = sptseg->s_data;
1591 
1592 	/*
1593 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
1594 	 * and therefore their pages are SE_SHARED locked
1595 	 * for the entire life of the segment.
1596 	 */
1597 	if ((!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) &&
1598 	    ((sptd->spt_flags & SHM_PAGEABLE) == 0)) {
1599 		goto softlock_decrement;
1600 	}
1601 
1602 	/*
1603 	 * Any thread is free to do a page_find and
1604 	 * page_unlock() on the pages within this seg.
1605 	 *
1606 	 * We are already holding the as->a_lock on the user's
1607 	 * real segment, but we need to hold the a_lock on the
1608 	 * underlying dummy as. This is mostly to satisfy the
1609 	 * underlying HAT layer.
1610 	 */
1611 	AS_LOCK_ENTER(sptseg->s_as, &sptseg->s_as->a_lock, RW_READER);
1612 	hat_unlock(sptseg->s_as->a_hat, sptseg_addr, len);
1613 	AS_LOCK_EXIT(sptseg->s_as, &sptseg->s_as->a_lock);
1614 
1615 	amp = sptd->spt_amp;
1616 	ASSERT(amp != NULL);
1617 	anon_index = seg_page(sptseg, sptseg_addr);
1618 
1619 	for (adr = sptseg_addr; adr < sptseg_addr + len; adr += PAGESIZE) {
1620 		ap = anon_get_ptr(amp->ahp, anon_index++);
1621 		ASSERT(ap != NULL);
1622 		swap_xlate(ap, &vp, &offset);
1623 
1624 		/*
1625 		 * Use page_find() instead of page_lookup() to
1626 		 * find the page since we know that it has a
1627 		 * "shared" lock.
1628 		 */
1629 		pp = page_find(vp, offset);
1630 		ASSERT(ap == anon_get_ptr(amp->ahp, anon_index - 1));
1631 		if (pp == NULL) {
1632 			panic("segspt_softunlock: "
1633 			    "addr %p, ap %p, vp %p, off %llx",
1634 			    (void *)adr, (void *)ap, (void *)vp, offset);
1635 			/*NOTREACHED*/
1636 		}
1637 
1638 		if (rw == S_WRITE) {
1639 			hat_setrefmod(pp);
1640 		} else if (rw != S_OTHER) {
1641 			hat_setref(pp);
1642 		}
1643 		page_unlock(pp);
1644 	}
1645 
1646 softlock_decrement:
1647 	npages = btopr(len);
1648 	ASSERT(shmd->shm_softlockcnt >= npages);
1649 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -npages);
1650 	if (shmd->shm_softlockcnt == 0) {
1651 		/*
1652 		 * All SOFTLOCKS are gone. Wakeup any waiting
1653 		 * unmappers so they can try again to unmap.
1654 		 * Check for waiters first without the mutex
1655 		 * held so we don't always grab the mutex on
1656 		 * softunlocks.
1657 		 */
1658 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1659 			mutex_enter(&seg->s_as->a_contents);
1660 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1661 				AS_CLRUNMAPWAIT(seg->s_as);
1662 				cv_broadcast(&seg->s_as->a_cv);
1663 			}
1664 			mutex_exit(&seg->s_as->a_contents);
1665 		}
1666 	}
1667 }
1668 
1669 int
1670 segspt_shmattach(struct seg *seg, caddr_t *argsp)
1671 {
1672 	struct shm_data *shmd_arg = (struct shm_data *)argsp;
1673 	struct shm_data *shmd;
1674 	struct anon_map *shm_amp = shmd_arg->shm_amp;
1675 	struct spt_data *sptd;
1676 	int error = 0;
1677 
1678 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1679 
1680 	shmd = kmem_zalloc((sizeof (*shmd)), KM_NOSLEEP);
1681 	if (shmd == NULL)
1682 		return (ENOMEM);
1683 
1684 	shmd->shm_sptas = shmd_arg->shm_sptas;
1685 	shmd->shm_amp = shm_amp;
1686 	shmd->shm_sptseg = shmd_arg->shm_sptseg;
1687 
1688 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, shm_amp, 0,
1689 	    NULL, 0, seg->s_size);
1690 
1691 	mutex_init(&shmd->shm_segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
1692 
1693 	seg->s_data = (void *)shmd;
1694 	seg->s_ops = &segspt_shmops;
1695 	seg->s_szc = shmd->shm_sptseg->s_szc;
1696 	sptd = shmd->shm_sptseg->s_data;
1697 
1698 	if (sptd->spt_flags & SHM_PAGEABLE) {
1699 		if ((shmd->shm_vpage = kmem_zalloc(btopr(shm_amp->size),
1700 		    KM_NOSLEEP)) == NULL) {
1701 			seg->s_data = (void *)NULL;
1702 			kmem_free(shmd, (sizeof (*shmd)));
1703 			return (ENOMEM);
1704 		}
1705 		shmd->shm_lckpgs = 0;
1706 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
1707 			if ((error = hat_share(seg->s_as->a_hat, seg->s_base,
1708 			    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1709 			    seg->s_size, seg->s_szc)) != 0) {
1710 				kmem_free(shmd->shm_vpage,
1711 				    btopr(shm_amp->size));
1712 			}
1713 		}
1714 	} else {
1715 		error = hat_share(seg->s_as->a_hat, seg->s_base,
1716 		    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1717 		    seg->s_size, seg->s_szc);
1718 	}
1719 	if (error) {
1720 		seg->s_szc = 0;
1721 		seg->s_data = (void *)NULL;
1722 		kmem_free(shmd, (sizeof (*shmd)));
1723 	} else {
1724 		ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1725 		shm_amp->refcnt++;
1726 		ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1727 	}
1728 	return (error);
1729 }
1730 
1731 int
1732 segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize)
1733 {
1734 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1735 	int reclaim = 1;
1736 
1737 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1738 retry:
1739 	if (shmd->shm_softlockcnt > 0) {
1740 		if (reclaim == 1) {
1741 			segspt_purge(seg);
1742 			reclaim = 0;
1743 			goto retry;
1744 		}
1745 		return (EAGAIN);
1746 	}
1747 
1748 	if (ssize != seg->s_size) {
1749 #ifdef DEBUG
1750 		cmn_err(CE_WARN, "Incompatible ssize %lx s_size %lx\n",
1751 		    ssize, seg->s_size);
1752 #endif
1753 		return (EINVAL);
1754 	}
1755 
1756 	(void) segspt_shmlockop(seg, raddr, shmd->shm_amp->size, 0, MC_UNLOCK,
1757 	    NULL, 0);
1758 	hat_unshare(seg->s_as->a_hat, raddr, ssize, seg->s_szc);
1759 
1760 	seg_free(seg);
1761 
1762 	return (0);
1763 }
1764 
1765 void
1766 segspt_shmfree(struct seg *seg)
1767 {
1768 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1769 	struct anon_map *shm_amp = shmd->shm_amp;
1770 
1771 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1772 
1773 	(void) segspt_shmlockop(seg, seg->s_base, shm_amp->size, 0,
1774 	    MC_UNLOCK, NULL, 0);
1775 
1776 	/*
1777 	 * Need to increment refcnt when attaching
1778 	 * and decrement when detaching because of dup().
1779 	 */
1780 	ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1781 	shm_amp->refcnt--;
1782 	ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1783 
1784 	if (shmd->shm_vpage) {	/* only for DISM */
1785 		kmem_free(shmd->shm_vpage, btopr(shm_amp->size));
1786 		shmd->shm_vpage = NULL;
1787 	}
1788 
1789 	/*
1790 	 * Take shm_segfree_syncmtx lock to let segspt_reclaim() finish if it's
1791 	 * still working with this segment without holding as lock.
1792 	 */
1793 	ASSERT(shmd->shm_softlockcnt == 0);
1794 	mutex_enter(&shmd->shm_segfree_syncmtx);
1795 	mutex_destroy(&shmd->shm_segfree_syncmtx);
1796 
1797 	kmem_free(shmd, sizeof (*shmd));
1798 }
1799 
1800 /*ARGSUSED*/
1801 int
1802 segspt_shmsetprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
1803 {
1804 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1805 
1806 	/*
1807 	 * Shared page table is more than shared mapping.
1808 	 *  Individual process sharing page tables can't change prot
1809 	 *  because there is only one set of page tables.
1810 	 *  This will be allowed after private page table is
1811 	 *  supported.
1812 	 */
1813 /* need to return correct status error? */
1814 	return (0);
1815 }
1816 
1817 
1818 faultcode_t
1819 segspt_dismfault(struct hat *hat, struct seg *seg, caddr_t addr,
1820     size_t len, enum fault_type type, enum seg_rw rw)
1821 {
1822 	struct  shm_data 	*shmd = (struct shm_data *)seg->s_data;
1823 	struct  seg		*sptseg = shmd->shm_sptseg;
1824 	struct  as		*curspt = shmd->shm_sptas;
1825 	struct  spt_data 	*sptd = sptseg->s_data;
1826 	pgcnt_t npages;
1827 	size_t  size;
1828 	caddr_t segspt_addr, shm_addr;
1829 	page_t  **ppa;
1830 	int	i;
1831 	ulong_t an_idx = 0;
1832 	int	err = 0;
1833 	int	dyn_ism_unmap = hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0);
1834 	size_t	pgsz;
1835 	pgcnt_t	pgcnt;
1836 	caddr_t	a;
1837 	pgcnt_t	pidx;
1838 
1839 #ifdef lint
1840 	hat = hat;
1841 #endif
1842 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1843 
1844 	/*
1845 	 * Because of the way spt is implemented
1846 	 * the realsize of the segment does not have to be
1847 	 * equal to the segment size itself. The segment size is
1848 	 * often in multiples of a page size larger than PAGESIZE.
1849 	 * The realsize is rounded up to the nearest PAGESIZE
1850 	 * based on what the user requested. This is a bit of
1851 	 * ungliness that is historical but not easily fixed
1852 	 * without re-designing the higher levels of ISM.
1853 	 */
1854 	ASSERT(addr >= seg->s_base);
1855 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
1856 		return (FC_NOMAP);
1857 	/*
1858 	 * For all of the following cases except F_PROT, we need to
1859 	 * make any necessary adjustments to addr and len
1860 	 * and get all of the necessary page_t's into an array called ppa[].
1861 	 *
1862 	 * The code in shmat() forces base addr and len of ISM segment
1863 	 * to be aligned to largest page size supported. Therefore,
1864 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
1865 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
1866 	 * in large pagesize chunks, or else we will screw up the HAT
1867 	 * layer by calling hat_memload_array() with differing page sizes
1868 	 * over a given virtual range.
1869 	 */
1870 	pgsz = page_get_pagesize(sptseg->s_szc);
1871 	pgcnt = page_get_pagecnt(sptseg->s_szc);
1872 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
1873 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
1874 	npages = btopr(size);
1875 
1876 	/*
1877 	 * Now we need to convert from addr in segshm to addr in segspt.
1878 	 */
1879 	an_idx = seg_page(seg, shm_addr);
1880 	segspt_addr = sptseg->s_base + ptob(an_idx);
1881 
1882 	ASSERT((segspt_addr + ptob(npages)) <=
1883 	    (sptseg->s_base + sptd->spt_realsize));
1884 	ASSERT(segspt_addr < (sptseg->s_base + sptseg->s_size));
1885 
1886 	switch (type) {
1887 
1888 	case F_SOFTLOCK:
1889 
1890 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
1891 		/*
1892 		 * Fall through to the F_INVAL case to load up the hat layer
1893 		 * entries with the HAT_LOAD_LOCK flag.
1894 		 */
1895 		/* FALLTHRU */
1896 	case F_INVAL:
1897 
1898 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
1899 			return (FC_NOMAP);
1900 
1901 		ppa = kmem_zalloc(npages * sizeof (page_t *), KM_SLEEP);
1902 
1903 		err = spt_anon_getpages(sptseg, segspt_addr, size, ppa);
1904 		if (err != 0) {
1905 			if (type == F_SOFTLOCK) {
1906 				atomic_add_long((ulong_t *)(
1907 				    &(shmd->shm_softlockcnt)), -npages);
1908 			}
1909 			goto dism_err;
1910 		}
1911 		AS_LOCK_ENTER(sptseg->s_as, &sptseg->s_as->a_lock, RW_READER);
1912 		a = segspt_addr;
1913 		pidx = 0;
1914 		if (type == F_SOFTLOCK) {
1915 
1916 			/*
1917 			 * Load up the translation keeping it
1918 			 * locked and don't unlock the page.
1919 			 */
1920 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
1921 				hat_memload_array(sptseg->s_as->a_hat,
1922 				    a, pgsz, &ppa[pidx], sptd->spt_prot,
1923 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
1924 			}
1925 		} else {
1926 			if (hat == seg->s_as->a_hat) {
1927 
1928 				/*
1929 				 * Migrate pages marked for migration
1930 				 */
1931 				if (lgrp_optimizations())
1932 					page_migrate(seg, shm_addr, ppa,
1933 					    npages);
1934 
1935 				/* CPU HAT */
1936 				for (; pidx < npages;
1937 				    a += pgsz, pidx += pgcnt) {
1938 					hat_memload_array(sptseg->s_as->a_hat,
1939 					    a, pgsz, &ppa[pidx],
1940 					    sptd->spt_prot,
1941 					    HAT_LOAD_SHARE);
1942 				}
1943 			} else {
1944 				/* XHAT. Pass real address */
1945 				hat_memload_array(hat, shm_addr,
1946 				    size, ppa, sptd->spt_prot, HAT_LOAD_SHARE);
1947 			}
1948 
1949 			/*
1950 			 * And now drop the SE_SHARED lock(s).
1951 			 */
1952 			if (dyn_ism_unmap) {
1953 				for (i = 0; i < npages; i++) {
1954 					page_unlock(ppa[i]);
1955 				}
1956 			}
1957 		}
1958 
1959 		if (!dyn_ism_unmap) {
1960 			if (hat_share(seg->s_as->a_hat, shm_addr,
1961 			    curspt->a_hat, segspt_addr, ptob(npages),
1962 			    seg->s_szc) != 0) {
1963 				panic("hat_share err in DISM fault");
1964 				/* NOTREACHED */
1965 			}
1966 			if (type == F_INVAL) {
1967 				for (i = 0; i < npages; i++) {
1968 					page_unlock(ppa[i]);
1969 				}
1970 			}
1971 		}
1972 		AS_LOCK_EXIT(sptseg->s_as, &sptseg->s_as->a_lock);
1973 dism_err:
1974 		kmem_free(ppa, npages * sizeof (page_t *));
1975 		return (err);
1976 
1977 	case F_SOFTUNLOCK:
1978 
1979 		/*
1980 		 * This is a bit ugly, we pass in the real seg pointer,
1981 		 * but the segspt_addr is the virtual address within the
1982 		 * dummy seg.
1983 		 */
1984 		segspt_softunlock(seg, segspt_addr, size, rw);
1985 		return (0);
1986 
1987 	case F_PROT:
1988 
1989 		/*
1990 		 * This takes care of the unusual case where a user
1991 		 * allocates a stack in shared memory and a register
1992 		 * window overflow is written to that stack page before
1993 		 * it is otherwise modified.
1994 		 *
1995 		 * We can get away with this because ISM segments are
1996 		 * always rw. Other than this unusual case, there
1997 		 * should be no instances of protection violations.
1998 		 */
1999 		return (0);
2000 
2001 	default:
2002 #ifdef DEBUG
2003 		panic("segspt_dismfault default type?");
2004 #else
2005 		return (FC_NOMAP);
2006 #endif
2007 	}
2008 }
2009 
2010 
2011 faultcode_t
2012 segspt_shmfault(struct hat *hat, struct seg *seg, caddr_t addr,
2013     size_t len, enum fault_type type, enum seg_rw rw)
2014 {
2015 	struct shm_data 	*shmd = (struct shm_data *)seg->s_data;
2016 	struct seg		*sptseg = shmd->shm_sptseg;
2017 	struct as		*curspt = shmd->shm_sptas;
2018 	struct spt_data 	*sptd   = sptseg->s_data;
2019 	pgcnt_t npages;
2020 	size_t size;
2021 	caddr_t sptseg_addr, shm_addr;
2022 	page_t *pp, **ppa;
2023 	int	i;
2024 	u_offset_t offset;
2025 	ulong_t anon_index = 0;
2026 	struct vnode *vp;
2027 	struct anon_map *amp;		/* XXX - for locknest */
2028 	struct anon *ap = NULL;
2029 	size_t		pgsz;
2030 	pgcnt_t		pgcnt;
2031 	caddr_t		a;
2032 	pgcnt_t		pidx;
2033 	size_t		sz;
2034 
2035 #ifdef lint
2036 	hat = hat;
2037 #endif
2038 
2039 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2040 
2041 	if (sptd->spt_flags & SHM_PAGEABLE) {
2042 		return (segspt_dismfault(hat, seg, addr, len, type, rw));
2043 	}
2044 
2045 	/*
2046 	 * Because of the way spt is implemented
2047 	 * the realsize of the segment does not have to be
2048 	 * equal to the segment size itself. The segment size is
2049 	 * often in multiples of a page size larger than PAGESIZE.
2050 	 * The realsize is rounded up to the nearest PAGESIZE
2051 	 * based on what the user requested. This is a bit of
2052 	 * ungliness that is historical but not easily fixed
2053 	 * without re-designing the higher levels of ISM.
2054 	 */
2055 	ASSERT(addr >= seg->s_base);
2056 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
2057 		return (FC_NOMAP);
2058 	/*
2059 	 * For all of the following cases except F_PROT, we need to
2060 	 * make any necessary adjustments to addr and len
2061 	 * and get all of the necessary page_t's into an array called ppa[].
2062 	 *
2063 	 * The code in shmat() forces base addr and len of ISM segment
2064 	 * to be aligned to largest page size supported. Therefore,
2065 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
2066 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
2067 	 * in large pagesize chunks, or else we will screw up the HAT
2068 	 * layer by calling hat_memload_array() with differing page sizes
2069 	 * over a given virtual range.
2070 	 */
2071 	pgsz = page_get_pagesize(sptseg->s_szc);
2072 	pgcnt = page_get_pagecnt(sptseg->s_szc);
2073 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
2074 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
2075 	npages = btopr(size);
2076 
2077 	/*
2078 	 * Now we need to convert from addr in segshm to addr in segspt.
2079 	 */
2080 	anon_index = seg_page(seg, shm_addr);
2081 	sptseg_addr = sptseg->s_base + ptob(anon_index);
2082 
2083 	/*
2084 	 * And now we may have to adjust npages downward if we have
2085 	 * exceeded the realsize of the segment or initial anon
2086 	 * allocations.
2087 	 */
2088 	if ((sptseg_addr + ptob(npages)) >
2089 	    (sptseg->s_base + sptd->spt_realsize))
2090 		size = (sptseg->s_base + sptd->spt_realsize) - sptseg_addr;
2091 
2092 	npages = btopr(size);
2093 
2094 	ASSERT(sptseg_addr < (sptseg->s_base + sptseg->s_size));
2095 	ASSERT((sptd->spt_flags & SHM_PAGEABLE) == 0);
2096 
2097 	switch (type) {
2098 
2099 	case F_SOFTLOCK:
2100 
2101 		/*
2102 		 * availrmem is decremented once during anon_swap_adjust()
2103 		 * and is incremented during the anon_unresv(), which is
2104 		 * called from shm_rm_amp() when the segment is destroyed.
2105 		 */
2106 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
2107 		/*
2108 		 * Some platforms assume that ISM pages are SE_SHARED
2109 		 * locked for the entire life of the segment.
2110 		 */
2111 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0))
2112 			return (0);
2113 		/*
2114 		 * Fall through to the F_INVAL case to load up the hat layer
2115 		 * entries with the HAT_LOAD_LOCK flag.
2116 		 */
2117 
2118 		/* FALLTHRU */
2119 	case F_INVAL:
2120 
2121 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
2122 			return (FC_NOMAP);
2123 
2124 		/*
2125 		 * Some platforms that do NOT support DYNAMIC_ISM_UNMAP
2126 		 * may still rely on this call to hat_share(). That
2127 		 * would imply that those hat's can fault on a
2128 		 * HAT_LOAD_LOCK translation, which would seem
2129 		 * contradictory.
2130 		 */
2131 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2132 			if (hat_share(seg->s_as->a_hat, seg->s_base,
2133 			    curspt->a_hat, sptseg->s_base,
2134 			    sptseg->s_size, sptseg->s_szc) != 0) {
2135 				panic("hat_share error in ISM fault");
2136 				/*NOTREACHED*/
2137 			}
2138 			return (0);
2139 		}
2140 		ppa = kmem_zalloc(sizeof (page_t *) * npages, KM_SLEEP);
2141 
2142 		/*
2143 		 * I see no need to lock the real seg,
2144 		 * here, because all of our work will be on the underlying
2145 		 * dummy seg.
2146 		 *
2147 		 * sptseg_addr and npages now account for large pages.
2148 		 */
2149 		amp = sptd->spt_amp;
2150 		ASSERT(amp != NULL);
2151 		anon_index = seg_page(sptseg, sptseg_addr);
2152 
2153 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2154 		for (i = 0; i < npages; i++) {
2155 			ap = anon_get_ptr(amp->ahp, anon_index++);
2156 			ASSERT(ap != NULL);
2157 			swap_xlate(ap, &vp, &offset);
2158 			pp = page_lookup(vp, offset, SE_SHARED);
2159 			ASSERT(pp != NULL);
2160 			ppa[i] = pp;
2161 		}
2162 		ANON_LOCK_EXIT(&amp->a_rwlock);
2163 		ASSERT(i == npages);
2164 
2165 		/*
2166 		 * We are already holding the as->a_lock on the user's
2167 		 * real segment, but we need to hold the a_lock on the
2168 		 * underlying dummy as. This is mostly to satisfy the
2169 		 * underlying HAT layer.
2170 		 */
2171 		AS_LOCK_ENTER(sptseg->s_as, &sptseg->s_as->a_lock, RW_READER);
2172 		a = sptseg_addr;
2173 		pidx = 0;
2174 		if (type == F_SOFTLOCK) {
2175 			/*
2176 			 * Load up the translation keeping it
2177 			 * locked and don't unlock the page.
2178 			 */
2179 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
2180 				sz = MIN(pgsz, ptob(npages - pidx));
2181 				hat_memload_array(sptseg->s_as->a_hat, a,
2182 				    sz, &ppa[pidx], sptd->spt_prot,
2183 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
2184 			}
2185 		} else {
2186 			if (hat == seg->s_as->a_hat) {
2187 
2188 				/*
2189 				 * Migrate pages marked for migration.
2190 				 */
2191 				if (lgrp_optimizations())
2192 					page_migrate(seg, shm_addr, ppa,
2193 					    npages);
2194 
2195 				/* CPU HAT */
2196 				for (; pidx < npages;
2197 				    a += pgsz, pidx += pgcnt) {
2198 					sz = MIN(pgsz, ptob(npages - pidx));
2199 					hat_memload_array(sptseg->s_as->a_hat,
2200 					    a, sz, &ppa[pidx],
2201 					    sptd->spt_prot, HAT_LOAD_SHARE);
2202 				}
2203 			} else {
2204 				/* XHAT. Pass real address */
2205 				hat_memload_array(hat, shm_addr,
2206 				    ptob(npages), ppa, sptd->spt_prot,
2207 				    HAT_LOAD_SHARE);
2208 			}
2209 
2210 			/*
2211 			 * And now drop the SE_SHARED lock(s).
2212 			 */
2213 			for (i = 0; i < npages; i++)
2214 				page_unlock(ppa[i]);
2215 		}
2216 		AS_LOCK_EXIT(sptseg->s_as, &sptseg->s_as->a_lock);
2217 
2218 		kmem_free(ppa, sizeof (page_t *) * npages);
2219 		return (0);
2220 	case F_SOFTUNLOCK:
2221 
2222 		/*
2223 		 * This is a bit ugly, we pass in the real seg pointer,
2224 		 * but the sptseg_addr is the virtual address within the
2225 		 * dummy seg.
2226 		 */
2227 		segspt_softunlock(seg, sptseg_addr, ptob(npages), rw);
2228 		return (0);
2229 
2230 	case F_PROT:
2231 
2232 		/*
2233 		 * This takes care of the unusual case where a user
2234 		 * allocates a stack in shared memory and a register
2235 		 * window overflow is written to that stack page before
2236 		 * it is otherwise modified.
2237 		 *
2238 		 * We can get away with this because ISM segments are
2239 		 * always rw. Other than this unusual case, there
2240 		 * should be no instances of protection violations.
2241 		 */
2242 		return (0);
2243 
2244 	default:
2245 #ifdef DEBUG
2246 		cmn_err(CE_WARN, "segspt_shmfault default type?");
2247 #endif
2248 		return (FC_NOMAP);
2249 	}
2250 }
2251 
2252 /*ARGSUSED*/
2253 static faultcode_t
2254 segspt_shmfaulta(struct seg *seg, caddr_t addr)
2255 {
2256 	return (0);
2257 }
2258 
2259 /*ARGSUSED*/
2260 static int
2261 segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta)
2262 {
2263 	return (0);
2264 }
2265 
2266 /*ARGSUSED*/
2267 static size_t
2268 segspt_shmswapout(struct seg *seg)
2269 {
2270 	return (0);
2271 }
2272 
2273 /*
2274  * duplicate the shared page tables
2275  */
2276 int
2277 segspt_shmdup(struct seg *seg, struct seg *newseg)
2278 {
2279 	struct shm_data		*shmd = (struct shm_data *)seg->s_data;
2280 	struct anon_map 	*amp = shmd->shm_amp;
2281 	struct shm_data 	*shmd_new;
2282 	struct seg		*spt_seg = shmd->shm_sptseg;
2283 	struct spt_data		*sptd = spt_seg->s_data;
2284 	int			error = 0;
2285 
2286 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
2287 
2288 	shmd_new = kmem_zalloc((sizeof (*shmd_new)), KM_SLEEP);
2289 	newseg->s_data = (void *)shmd_new;
2290 	shmd_new->shm_sptas = shmd->shm_sptas;
2291 	shmd_new->shm_amp = amp;
2292 	shmd_new->shm_sptseg = shmd->shm_sptseg;
2293 	newseg->s_ops = &segspt_shmops;
2294 	newseg->s_szc = seg->s_szc;
2295 	ASSERT(seg->s_szc == shmd->shm_sptseg->s_szc);
2296 
2297 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2298 	amp->refcnt++;
2299 	ANON_LOCK_EXIT(&amp->a_rwlock);
2300 
2301 	if (sptd->spt_flags & SHM_PAGEABLE) {
2302 		shmd_new->shm_vpage = kmem_zalloc(btopr(amp->size), KM_SLEEP);
2303 		shmd_new->shm_lckpgs = 0;
2304 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2305 			if ((error = hat_share(newseg->s_as->a_hat,
2306 			    newseg->s_base, shmd->shm_sptas->a_hat, SEGSPTADDR,
2307 			    seg->s_size, seg->s_szc)) != 0) {
2308 				kmem_free(shmd_new->shm_vpage,
2309 				    btopr(amp->size));
2310 			}
2311 		}
2312 		return (error);
2313 	} else {
2314 		return (hat_share(newseg->s_as->a_hat, newseg->s_base,
2315 		    shmd->shm_sptas->a_hat, SEGSPTADDR, seg->s_size,
2316 		    seg->s_szc));
2317 
2318 	}
2319 }
2320 
2321 /*ARGSUSED*/
2322 int
2323 segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size, uint_t prot)
2324 {
2325 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2326 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2327 
2328 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2329 
2330 	/*
2331 	 * ISM segment is always rw.
2332 	 */
2333 	return (((sptd->spt_prot & prot) != prot) ? EACCES : 0);
2334 }
2335 
2336 /*
2337  * Return an array of locked large pages, for empty slots allocate
2338  * private zero-filled anon pages.
2339  */
2340 static int
2341 spt_anon_getpages(
2342 	struct seg *sptseg,
2343 	caddr_t sptaddr,
2344 	size_t len,
2345 	page_t *ppa[])
2346 {
2347 	struct  spt_data *sptd = sptseg->s_data;
2348 	struct  anon_map *amp = sptd->spt_amp;
2349 	enum 	seg_rw rw = sptd->spt_prot;
2350 	uint_t	szc = sptseg->s_szc;
2351 	size_t	pg_sz, share_sz = page_get_pagesize(szc);
2352 	pgcnt_t	lp_npgs;
2353 	caddr_t	lp_addr, e_sptaddr;
2354 	uint_t	vpprot, ppa_szc = 0;
2355 	struct  vpage *vpage = NULL;
2356 	ulong_t	j, ppa_idx;
2357 	int	err, ierr = 0;
2358 	pgcnt_t	an_idx;
2359 	anon_sync_obj_t cookie;
2360 	int anon_locked = 0;
2361 	pgcnt_t amp_pgs;
2362 
2363 
2364 	ASSERT(IS_P2ALIGNED(sptaddr, share_sz) && IS_P2ALIGNED(len, share_sz));
2365 	ASSERT(len != 0);
2366 
2367 	pg_sz = share_sz;
2368 	lp_npgs = btop(pg_sz);
2369 	lp_addr = sptaddr;
2370 	e_sptaddr = sptaddr + len;
2371 	an_idx = seg_page(sptseg, sptaddr);
2372 	ppa_idx = 0;
2373 
2374 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2375 
2376 	amp_pgs = page_get_pagecnt(amp->a_szc);
2377 
2378 	/*CONSTCOND*/
2379 	while (1) {
2380 		for (; lp_addr < e_sptaddr;
2381 		    an_idx += lp_npgs, lp_addr += pg_sz, ppa_idx += lp_npgs) {
2382 
2383 			/*
2384 			 * If we're currently locked, and we get to a new
2385 			 * page, unlock our current anon chunk.
2386 			 */
2387 			if (anon_locked && P2PHASE(an_idx, amp_pgs) == 0) {
2388 				anon_array_exit(&cookie);
2389 				anon_locked = 0;
2390 			}
2391 			if (!anon_locked) {
2392 				anon_array_enter(amp, an_idx, &cookie);
2393 				anon_locked = 1;
2394 			}
2395 			ppa_szc = (uint_t)-1;
2396 			ierr = anon_map_getpages(amp, an_idx, szc, sptseg,
2397 			    lp_addr, sptd->spt_prot, &vpprot, &ppa[ppa_idx],
2398 			    &ppa_szc, vpage, rw, 0, segvn_anypgsz, 0, kcred);
2399 
2400 			if (ierr != 0) {
2401 				if (ierr > 0) {
2402 					err = FC_MAKE_ERR(ierr);
2403 					goto lpgs_err;
2404 				}
2405 				break;
2406 			}
2407 		}
2408 		if (lp_addr == e_sptaddr) {
2409 			break;
2410 		}
2411 		ASSERT(lp_addr < e_sptaddr);
2412 
2413 		/*
2414 		 * ierr == -1 means we failed to allocate a large page.
2415 		 * so do a size down operation.
2416 		 *
2417 		 * ierr == -2 means some other process that privately shares
2418 		 * pages with this process has allocated a larger page and we
2419 		 * need to retry with larger pages. So do a size up
2420 		 * operation. This relies on the fact that large pages are
2421 		 * never partially shared i.e. if we share any constituent
2422 		 * page of a large page with another process we must share the
2423 		 * entire large page. Note this cannot happen for SOFTLOCK
2424 		 * case, unless current address (lpaddr) is at the beginning
2425 		 * of the next page size boundary because the other process
2426 		 * couldn't have relocated locked pages.
2427 		 */
2428 		ASSERT(ierr == -1 || ierr == -2);
2429 		if (segvn_anypgsz) {
2430 			ASSERT(ierr == -2 || szc != 0);
2431 			ASSERT(ierr == -1 || szc < sptseg->s_szc);
2432 			szc = (ierr == -1) ? szc - 1 : szc + 1;
2433 		} else {
2434 			/*
2435 			 * For faults and segvn_anypgsz == 0
2436 			 * we need to be careful not to loop forever
2437 			 * if existing page is found with szc other
2438 			 * than 0 or seg->s_szc. This could be due
2439 			 * to page relocations on behalf of DR or
2440 			 * more likely large page creation. For this
2441 			 * case simply re-size to existing page's szc
2442 			 * if returned by anon_map_getpages().
2443 			 */
2444 			if (ppa_szc == (uint_t)-1) {
2445 				szc = (ierr == -1) ? 0 : sptseg->s_szc;
2446 			} else {
2447 				ASSERT(ppa_szc <= sptseg->s_szc);
2448 				ASSERT(ierr == -2 || ppa_szc < szc);
2449 				ASSERT(ierr == -1 || ppa_szc > szc);
2450 				szc = ppa_szc;
2451 			}
2452 		}
2453 		pg_sz = page_get_pagesize(szc);
2454 		lp_npgs = btop(pg_sz);
2455 		ASSERT(IS_P2ALIGNED(lp_addr, pg_sz));
2456 	}
2457 	if (anon_locked) {
2458 		anon_array_exit(&cookie);
2459 	}
2460 	ANON_LOCK_EXIT(&amp->a_rwlock);
2461 	return (0);
2462 
2463 lpgs_err:
2464 	if (anon_locked) {
2465 		anon_array_exit(&cookie);
2466 	}
2467 	ANON_LOCK_EXIT(&amp->a_rwlock);
2468 	for (j = 0; j < ppa_idx; j++)
2469 		page_unlock(ppa[j]);
2470 	return (err);
2471 }
2472 
2473 /*
2474  * count the number of bytes in a set of spt pages that are currently not
2475  * locked
2476  */
2477 static rctl_qty_t
2478 spt_unlockedbytes(pgcnt_t npages, page_t **ppa)
2479 {
2480 	ulong_t	i;
2481 	rctl_qty_t unlocked = 0;
2482 
2483 	for (i = 0; i < npages; i++) {
2484 		if (ppa[i]->p_lckcnt == 0)
2485 			unlocked += PAGESIZE;
2486 	}
2487 	return (unlocked);
2488 }
2489 
2490 int
2491 spt_lockpages(struct seg *seg, pgcnt_t anon_index, pgcnt_t npages,
2492     page_t **ppa, ulong_t *lockmap, size_t pos,
2493     rctl_qty_t *locked)
2494 {
2495 	struct shm_data *shmd = seg->s_data;
2496 	struct spt_data *sptd = shmd->shm_sptseg->s_data;
2497 	ulong_t	i;
2498 	int	kernel;
2499 
2500 	/* return the number of bytes actually locked */
2501 	*locked = 0;
2502 	for (i = 0; i < npages; anon_index++, pos++, i++) {
2503 		if (!(shmd->shm_vpage[anon_index] & DISM_PG_LOCKED)) {
2504 			if (sptd->spt_ppa_lckcnt[anon_index] <
2505 			    (ushort_t)DISM_LOCK_MAX) {
2506 				if (++sptd->spt_ppa_lckcnt[anon_index] ==
2507 				    (ushort_t)DISM_LOCK_MAX) {
2508 					cmn_err(CE_WARN,
2509 					    "DISM page lock limit "
2510 					    "reached on DISM offset 0x%lx\n",
2511 					    anon_index << PAGESHIFT);
2512 				}
2513 				kernel = (sptd->spt_ppa &&
2514 				    sptd->spt_ppa[anon_index]) ? 1 : 0;
2515 				if (!page_pp_lock(ppa[i], 0, kernel)) {
2516 					sptd->spt_ppa_lckcnt[anon_index]--;
2517 					return (EAGAIN);
2518 				}
2519 				/* if this is a newly locked page, count it */
2520 				if (ppa[i]->p_lckcnt == 1) {
2521 					*locked += PAGESIZE;
2522 				}
2523 				shmd->shm_lckpgs++;
2524 				shmd->shm_vpage[anon_index] |= DISM_PG_LOCKED;
2525 				if (lockmap != NULL)
2526 					BT_SET(lockmap, pos);
2527 			}
2528 		}
2529 	}
2530 	return (0);
2531 }
2532 
2533 /*ARGSUSED*/
2534 static int
2535 segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
2536     int attr, int op, ulong_t *lockmap, size_t pos)
2537 {
2538 	struct shm_data *shmd = seg->s_data;
2539 	struct seg	*sptseg = shmd->shm_sptseg;
2540 	struct spt_data *sptd = sptseg->s_data;
2541 	struct kshmid	*sp = sptd->spt_amp->a_sp;
2542 	pgcnt_t		npages, a_npages;
2543 	page_t		**ppa;
2544 	pgcnt_t 	an_idx, a_an_idx, ppa_idx;
2545 	caddr_t		spt_addr, a_addr;	/* spt and aligned address */
2546 	size_t		a_len;			/* aligned len */
2547 	size_t		share_sz;
2548 	ulong_t		i;
2549 	int		sts = 0;
2550 	rctl_qty_t	unlocked = 0;
2551 	rctl_qty_t	locked = 0;
2552 	struct proc	*p = curproc;
2553 	kproject_t	*proj;
2554 
2555 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2556 	ASSERT(sp != NULL);
2557 
2558 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
2559 		return (0);
2560 	}
2561 
2562 	addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2563 	an_idx = seg_page(seg, addr);
2564 	npages = btopr(len);
2565 
2566 	if (an_idx + npages > btopr(shmd->shm_amp->size)) {
2567 		return (ENOMEM);
2568 	}
2569 
2570 	/*
2571 	 * A shm's project never changes, so no lock needed.
2572 	 * The shm has a hold on the project, so it will not go away.
2573 	 * Since we have a mapping to shm within this zone, we know
2574 	 * that the zone will not go away.
2575 	 */
2576 	proj = sp->shm_perm.ipc_proj;
2577 
2578 	if (op == MC_LOCK) {
2579 
2580 		/*
2581 		 * Need to align addr and size request if they are not
2582 		 * aligned so we can always allocate large page(s) however
2583 		 * we only lock what was requested in initial request.
2584 		 */
2585 		share_sz = page_get_pagesize(sptseg->s_szc);
2586 		a_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_sz);
2587 		a_len = P2ROUNDUP((uintptr_t)(((addr + len) - a_addr)),
2588 		    share_sz);
2589 		a_npages = btop(a_len);
2590 		a_an_idx = seg_page(seg, a_addr);
2591 		spt_addr = sptseg->s_base + ptob(a_an_idx);
2592 		ppa_idx = an_idx - a_an_idx;
2593 
2594 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * a_npages),
2595 		    KM_NOSLEEP)) == NULL) {
2596 			return (ENOMEM);
2597 		}
2598 
2599 		/*
2600 		 * Don't cache any new pages for IO and
2601 		 * flush any cached pages.
2602 		 */
2603 		mutex_enter(&sptd->spt_lock);
2604 		if (sptd->spt_ppa != NULL)
2605 			sptd->spt_flags |= DISM_PPA_CHANGED;
2606 
2607 		sts = spt_anon_getpages(sptseg, spt_addr, a_len, ppa);
2608 		if (sts != 0) {
2609 			mutex_exit(&sptd->spt_lock);
2610 			kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2611 			return (sts);
2612 		}
2613 
2614 		mutex_enter(&sp->shm_mlock);
2615 		/* enforce locked memory rctl */
2616 		unlocked = spt_unlockedbytes(npages, &ppa[ppa_idx]);
2617 
2618 		mutex_enter(&p->p_lock);
2619 		if (rctl_incr_locked_mem(p, proj, unlocked, 0)) {
2620 			mutex_exit(&p->p_lock);
2621 			sts = EAGAIN;
2622 		} else {
2623 			mutex_exit(&p->p_lock);
2624 			sts = spt_lockpages(seg, an_idx, npages,
2625 			    &ppa[ppa_idx], lockmap, pos, &locked);
2626 
2627 			/*
2628 			 * correct locked count if not all pages could be
2629 			 * locked
2630 			 */
2631 			if ((unlocked - locked) > 0) {
2632 				rctl_decr_locked_mem(NULL, proj,
2633 				    (unlocked - locked), 0);
2634 			}
2635 		}
2636 		/*
2637 		 * unlock pages
2638 		 */
2639 		for (i = 0; i < a_npages; i++)
2640 			page_unlock(ppa[i]);
2641 		if (sptd->spt_ppa != NULL)
2642 			sptd->spt_flags |= DISM_PPA_CHANGED;
2643 		mutex_exit(&sp->shm_mlock);
2644 		mutex_exit(&sptd->spt_lock);
2645 
2646 		kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2647 
2648 	} else if (op == MC_UNLOCK) { /* unlock */
2649 		struct anon_map *amp;
2650 		struct anon 	*ap;
2651 		struct vnode 	*vp;
2652 		u_offset_t 	off;
2653 		struct page	*pp;
2654 		int		kernel;
2655 		anon_sync_obj_t cookie;
2656 		rctl_qty_t	unlocked = 0;
2657 		page_t		**ppa;
2658 
2659 		amp = sptd->spt_amp;
2660 		mutex_enter(&sptd->spt_lock);
2661 		if (shmd->shm_lckpgs == 0) {
2662 			mutex_exit(&sptd->spt_lock);
2663 			return (0);
2664 		}
2665 		/*
2666 		 * Don't cache new IO pages.
2667 		 */
2668 		if (sptd->spt_ppa != NULL)
2669 			sptd->spt_flags |= DISM_PPA_CHANGED;
2670 
2671 		mutex_enter(&sp->shm_mlock);
2672 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2673 		for (i = 0; i < npages; i++, an_idx++) {
2674 			if (shmd->shm_vpage[an_idx] & DISM_PG_LOCKED) {
2675 				anon_array_enter(amp, an_idx, &cookie);
2676 				ap = anon_get_ptr(amp->ahp, an_idx);
2677 				ASSERT(ap);
2678 
2679 				swap_xlate(ap, &vp, &off);
2680 				anon_array_exit(&cookie);
2681 				pp = page_lookup(vp, off, SE_SHARED);
2682 				ASSERT(pp);
2683 				/*
2684 				 * the availrmem is decremented only for
2685 				 * pages which are not in seg pcache,
2686 				 * for pages in seg pcache availrmem was
2687 				 * decremented in _dismpagelock() (if
2688 				 * they were not locked here)
2689 				 */
2690 				kernel = (sptd->spt_ppa &&
2691 				    sptd->spt_ppa[an_idx]) ? 1 : 0;
2692 				ASSERT(pp->p_lckcnt > 0);
2693 				page_pp_unlock(pp, 0, kernel);
2694 				if (pp->p_lckcnt == 0)
2695 					unlocked += PAGESIZE;
2696 				page_unlock(pp);
2697 				shmd->shm_vpage[an_idx] &= ~DISM_PG_LOCKED;
2698 				sptd->spt_ppa_lckcnt[an_idx]--;
2699 				shmd->shm_lckpgs--;
2700 			}
2701 		}
2702 		ANON_LOCK_EXIT(&amp->a_rwlock);
2703 		if ((ppa = sptd->spt_ppa) != NULL)
2704 			sptd->spt_flags |= DISM_PPA_CHANGED;
2705 		mutex_exit(&sptd->spt_lock);
2706 
2707 		rctl_decr_locked_mem(NULL, proj, unlocked, 0);
2708 		mutex_exit(&sp->shm_mlock);
2709 
2710 		if (ppa != NULL)
2711 			seg_ppurge_wiredpp(ppa);
2712 	}
2713 	return (sts);
2714 }
2715 
2716 /*ARGSUSED*/
2717 int
2718 segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
2719 {
2720 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2721 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2722 	spgcnt_t pgno = seg_page(seg, addr+len) - seg_page(seg, addr) + 1;
2723 
2724 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2725 
2726 	/*
2727 	 * ISM segment is always rw.
2728 	 */
2729 	while (--pgno >= 0)
2730 		*protv++ = sptd->spt_prot;
2731 	return (0);
2732 }
2733 
2734 /*ARGSUSED*/
2735 u_offset_t
2736 segspt_shmgetoffset(struct seg *seg, caddr_t addr)
2737 {
2738 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2739 
2740 	/* Offset does not matter in ISM memory */
2741 
2742 	return ((u_offset_t)0);
2743 }
2744 
2745 /* ARGSUSED */
2746 int
2747 segspt_shmgettype(struct seg *seg, caddr_t addr)
2748 {
2749 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2750 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2751 
2752 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2753 
2754 	/*
2755 	 * The shared memory mapping is always MAP_SHARED, SWAP is only
2756 	 * reserved for DISM
2757 	 */
2758 	return (MAP_SHARED |
2759 	    ((sptd->spt_flags & SHM_PAGEABLE) ? 0 : MAP_NORESERVE));
2760 }
2761 
2762 /*ARGSUSED*/
2763 int
2764 segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
2765 {
2766 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2767 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2768 
2769 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2770 
2771 	*vpp = sptd->spt_vp;
2772 	return (0);
2773 }
2774 
2775 /*
2776  * We need to wait for pending IO to complete to a DISM segment in order for
2777  * pages to get kicked out of the seg_pcache.  120 seconds should be more
2778  * than enough time to wait.
2779  */
2780 static clock_t spt_pcache_wait = 120;
2781 
2782 /*ARGSUSED*/
2783 static int
2784 segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
2785 {
2786 	struct shm_data	*shmd = (struct shm_data *)seg->s_data;
2787 	struct spt_data	*sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2788 	struct anon_map	*amp;
2789 	pgcnt_t pg_idx;
2790 	ushort_t gen;
2791 	clock_t	end_lbolt;
2792 	int writer;
2793 	page_t **ppa;
2794 
2795 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2796 
2797 	if (behav == MADV_FREE) {
2798 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0)
2799 			return (0);
2800 
2801 		amp = sptd->spt_amp;
2802 		pg_idx = seg_page(seg, addr);
2803 
2804 		mutex_enter(&sptd->spt_lock);
2805 		if ((ppa = sptd->spt_ppa) == NULL) {
2806 			mutex_exit(&sptd->spt_lock);
2807 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2808 			anon_disclaim(amp, pg_idx, len);
2809 			ANON_LOCK_EXIT(&amp->a_rwlock);
2810 			return (0);
2811 		}
2812 
2813 		sptd->spt_flags |= DISM_PPA_CHANGED;
2814 		gen = sptd->spt_gen;
2815 
2816 		mutex_exit(&sptd->spt_lock);
2817 
2818 		/*
2819 		 * Purge all DISM cached pages
2820 		 */
2821 		seg_ppurge_wiredpp(ppa);
2822 
2823 		/*
2824 		 * Drop the AS_LOCK so that other threads can grab it
2825 		 * in the as_pageunlock path and hopefully get the segment
2826 		 * kicked out of the seg_pcache.  We bump the shm_softlockcnt
2827 		 * to keep this segment resident.
2828 		 */
2829 		writer = AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock);
2830 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), 1);
2831 		AS_LOCK_EXIT(seg->s_as, &seg->s_as->a_lock);
2832 
2833 		mutex_enter(&sptd->spt_lock);
2834 
2835 		end_lbolt = lbolt + (hz * spt_pcache_wait);
2836 
2837 		/*
2838 		 * Try to wait for pages to get kicked out of the seg_pcache.
2839 		 */
2840 		while (sptd->spt_gen == gen &&
2841 		    (sptd->spt_flags & DISM_PPA_CHANGED) &&
2842 		    lbolt < end_lbolt) {
2843 			if (!cv_timedwait_sig(&sptd->spt_cv,
2844 			    &sptd->spt_lock, end_lbolt)) {
2845 				break;
2846 			}
2847 		}
2848 
2849 		mutex_exit(&sptd->spt_lock);
2850 
2851 		/* Regrab the AS_LOCK and release our hold on the segment */
2852 		AS_LOCK_ENTER(seg->s_as, &seg->s_as->a_lock,
2853 		    writer ? RW_WRITER : RW_READER);
2854 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -1);
2855 		if (shmd->shm_softlockcnt <= 0) {
2856 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2857 				mutex_enter(&seg->s_as->a_contents);
2858 				if (AS_ISUNMAPWAIT(seg->s_as)) {
2859 					AS_CLRUNMAPWAIT(seg->s_as);
2860 					cv_broadcast(&seg->s_as->a_cv);
2861 				}
2862 				mutex_exit(&seg->s_as->a_contents);
2863 			}
2864 		}
2865 
2866 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2867 		anon_disclaim(amp, pg_idx, len);
2868 		ANON_LOCK_EXIT(&amp->a_rwlock);
2869 	} else if (lgrp_optimizations() && (behav == MADV_ACCESS_LWP ||
2870 	    behav == MADV_ACCESS_MANY || behav == MADV_ACCESS_DEFAULT)) {
2871 		int			already_set;
2872 		ulong_t			anon_index;
2873 		lgrp_mem_policy_t	policy;
2874 		caddr_t			shm_addr;
2875 		size_t			share_size;
2876 		size_t			size;
2877 		struct seg		*sptseg = shmd->shm_sptseg;
2878 		caddr_t			sptseg_addr;
2879 
2880 		/*
2881 		 * Align address and length to page size of underlying segment
2882 		 */
2883 		share_size = page_get_pagesize(shmd->shm_sptseg->s_szc);
2884 		shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_size);
2885 		size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)),
2886 		    share_size);
2887 
2888 		amp = shmd->shm_amp;
2889 		anon_index = seg_page(seg, shm_addr);
2890 
2891 		/*
2892 		 * And now we may have to adjust size downward if we have
2893 		 * exceeded the realsize of the segment or initial anon
2894 		 * allocations.
2895 		 */
2896 		sptseg_addr = sptseg->s_base + ptob(anon_index);
2897 		if ((sptseg_addr + size) >
2898 		    (sptseg->s_base + sptd->spt_realsize))
2899 			size = (sptseg->s_base + sptd->spt_realsize) -
2900 			    sptseg_addr;
2901 
2902 		/*
2903 		 * Set memory allocation policy for this segment
2904 		 */
2905 		policy = lgrp_madv_to_policy(behav, len, MAP_SHARED);
2906 		already_set = lgrp_shm_policy_set(policy, amp, anon_index,
2907 		    NULL, 0, len);
2908 
2909 		/*
2910 		 * If random memory allocation policy set already,
2911 		 * don't bother reapplying it.
2912 		 */
2913 		if (already_set && !LGRP_MEM_POLICY_REAPPLICABLE(policy))
2914 			return (0);
2915 
2916 		/*
2917 		 * Mark any existing pages in the given range for
2918 		 * migration, flushing the I/O page cache, and using
2919 		 * underlying segment to calculate anon index and get
2920 		 * anonmap and vnode pointer from
2921 		 */
2922 		if (shmd->shm_softlockcnt > 0)
2923 			segspt_purge(seg);
2924 
2925 		page_mark_migrate(seg, shm_addr, size, amp, 0, NULL, 0, 0);
2926 	}
2927 
2928 	return (0);
2929 }
2930 
2931 /*ARGSUSED*/
2932 void
2933 segspt_shmdump(struct seg *seg)
2934 {
2935 	/* no-op for ISM segment */
2936 }
2937 
2938 /*ARGSUSED*/
2939 static faultcode_t
2940 segspt_shmsetpgsz(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
2941 {
2942 	return (ENOTSUP);
2943 }
2944 
2945 /*
2946  * get a memory ID for an addr in a given segment
2947  */
2948 static int
2949 segspt_shmgetmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
2950 {
2951 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2952 	struct anon 	*ap;
2953 	size_t		anon_index;
2954 	struct anon_map	*amp = shmd->shm_amp;
2955 	struct spt_data	*sptd = shmd->shm_sptseg->s_data;
2956 	struct seg	*sptseg = shmd->shm_sptseg;
2957 	anon_sync_obj_t	cookie;
2958 
2959 	anon_index = seg_page(seg, addr);
2960 
2961 	if (addr > (seg->s_base + sptd->spt_realsize)) {
2962 		return (EFAULT);
2963 	}
2964 
2965 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2966 	anon_array_enter(amp, anon_index, &cookie);
2967 	ap = anon_get_ptr(amp->ahp, anon_index);
2968 	if (ap == NULL) {
2969 		struct page *pp;
2970 		caddr_t spt_addr = sptseg->s_base + ptob(anon_index);
2971 
2972 		pp = anon_zero(sptseg, spt_addr, &ap, kcred);
2973 		if (pp == NULL) {
2974 			anon_array_exit(&cookie);
2975 			ANON_LOCK_EXIT(&amp->a_rwlock);
2976 			return (ENOMEM);
2977 		}
2978 		(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
2979 		page_unlock(pp);
2980 	}
2981 	anon_array_exit(&cookie);
2982 	ANON_LOCK_EXIT(&amp->a_rwlock);
2983 	memidp->val[0] = (uintptr_t)ap;
2984 	memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
2985 	return (0);
2986 }
2987 
2988 /*
2989  * Get memory allocation policy info for specified address in given segment
2990  */
2991 static lgrp_mem_policy_info_t *
2992 segspt_shmgetpolicy(struct seg *seg, caddr_t addr)
2993 {
2994 	struct anon_map		*amp;
2995 	ulong_t			anon_index;
2996 	lgrp_mem_policy_info_t	*policy_info;
2997 	struct shm_data		*shm_data;
2998 
2999 	ASSERT(seg != NULL);
3000 
3001 	/*
3002 	 * Get anon_map from segshm
3003 	 *
3004 	 * Assume that no lock needs to be held on anon_map, since
3005 	 * it should be protected by its reference count which must be
3006 	 * nonzero for an existing segment
3007 	 * Need to grab readers lock on policy tree though
3008 	 */
3009 	shm_data = (struct shm_data *)seg->s_data;
3010 	if (shm_data == NULL)
3011 		return (NULL);
3012 	amp = shm_data->shm_amp;
3013 	ASSERT(amp->refcnt != 0);
3014 
3015 	/*
3016 	 * Get policy info
3017 	 *
3018 	 * Assume starting anon index of 0
3019 	 */
3020 	anon_index = seg_page(seg, addr);
3021 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
3022 
3023 	return (policy_info);
3024 }
3025 
3026 /*ARGSUSED*/
3027 static int
3028 segspt_shmcapable(struct seg *seg, segcapability_t capability)
3029 {
3030 	return (0);
3031 }
3032