xref: /titanic_41/usr/src/uts/common/vm/seg_spt.c (revision 0bb073995ac5a95bd35f2dd790df1ea3d8c2d507)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/param.h>
29 #include <sys/user.h>
30 #include <sys/mman.h>
31 #include <sys/kmem.h>
32 #include <sys/sysmacros.h>
33 #include <sys/cmn_err.h>
34 #include <sys/systm.h>
35 #include <sys/tuneable.h>
36 #include <vm/hat.h>
37 #include <vm/seg.h>
38 #include <vm/as.h>
39 #include <vm/anon.h>
40 #include <vm/page.h>
41 #include <sys/buf.h>
42 #include <sys/swap.h>
43 #include <sys/atomic.h>
44 #include <vm/seg_spt.h>
45 #include <sys/debug.h>
46 #include <sys/vtrace.h>
47 #include <sys/shm.h>
48 #include <sys/shm_impl.h>
49 #include <sys/lgrp.h>
50 #include <sys/vmsystm.h>
51 #include <sys/policy.h>
52 #include <sys/project.h>
53 #include <sys/tnf_probe.h>
54 #include <sys/zone.h>
55 
56 #define	SEGSPTADDR	(caddr_t)0x0
57 
58 /*
59  * # pages used for spt
60  */
61 size_t	spt_used;
62 
63 /*
64  * segspt_minfree is the memory left for system after ISM
65  * locked its pages; it is set up to 5% of availrmem in
66  * sptcreate when ISM is created.  ISM should not use more
67  * than ~90% of availrmem; if it does, then the performance
68  * of the system may decrease. Machines with large memories may
69  * be able to use up more memory for ISM so we set the default
70  * segspt_minfree to 5% (which gives ISM max 95% of availrmem.
71  * If somebody wants even more memory for ISM (risking hanging
72  * the system) they can patch the segspt_minfree to smaller number.
73  */
74 pgcnt_t segspt_minfree = 0;
75 
76 static int segspt_create(struct seg *seg, caddr_t argsp);
77 static int segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize);
78 static void segspt_free(struct seg *seg);
79 static void segspt_free_pages(struct seg *seg, caddr_t addr, size_t len);
80 static lgrp_mem_policy_info_t *segspt_getpolicy(struct seg *seg, caddr_t addr);
81 
82 static void
83 segspt_badop()
84 {
85 	panic("segspt_badop called");
86 	/*NOTREACHED*/
87 }
88 
89 #define	SEGSPT_BADOP(t)	(t(*)())segspt_badop
90 
91 struct seg_ops segspt_ops = {
92 	SEGSPT_BADOP(int),		/* dup */
93 	segspt_unmap,
94 	segspt_free,
95 	SEGSPT_BADOP(int),		/* fault */
96 	SEGSPT_BADOP(faultcode_t),	/* faulta */
97 	SEGSPT_BADOP(int),		/* setprot */
98 	SEGSPT_BADOP(int),		/* checkprot */
99 	SEGSPT_BADOP(int),		/* kluster */
100 	SEGSPT_BADOP(size_t),		/* swapout */
101 	SEGSPT_BADOP(int),		/* sync */
102 	SEGSPT_BADOP(size_t),		/* incore */
103 	SEGSPT_BADOP(int),		/* lockop */
104 	SEGSPT_BADOP(int),		/* getprot */
105 	SEGSPT_BADOP(u_offset_t), 	/* getoffset */
106 	SEGSPT_BADOP(int),		/* gettype */
107 	SEGSPT_BADOP(int),		/* getvp */
108 	SEGSPT_BADOP(int),		/* advise */
109 	SEGSPT_BADOP(void),		/* dump */
110 	SEGSPT_BADOP(int),		/* pagelock */
111 	SEGSPT_BADOP(int),		/* setpgsz */
112 	SEGSPT_BADOP(int),		/* getmemid */
113 	segspt_getpolicy,		/* getpolicy */
114 	SEGSPT_BADOP(int),		/* capable */
115 };
116 
117 static int segspt_shmdup(struct seg *seg, struct seg *newseg);
118 static int segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize);
119 static void segspt_shmfree(struct seg *seg);
120 static faultcode_t segspt_shmfault(struct hat *hat, struct seg *seg,
121 		caddr_t addr, size_t len, enum fault_type type, enum seg_rw rw);
122 static faultcode_t segspt_shmfaulta(struct seg *seg, caddr_t addr);
123 static int segspt_shmsetprot(register struct seg *seg, register caddr_t addr,
124 			register size_t len, register uint_t prot);
125 static int segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size,
126 			uint_t prot);
127 static int	segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta);
128 static size_t	segspt_shmswapout(struct seg *seg);
129 static size_t segspt_shmincore(struct seg *seg, caddr_t addr, size_t len,
130 			register char *vec);
131 static int segspt_shmsync(struct seg *seg, register caddr_t addr, size_t len,
132 			int attr, uint_t flags);
133 static int segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
134 			int attr, int op, ulong_t *lockmap, size_t pos);
135 static int segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len,
136 			uint_t *protv);
137 static u_offset_t segspt_shmgetoffset(struct seg *seg, caddr_t addr);
138 static int segspt_shmgettype(struct seg *seg, caddr_t addr);
139 static int segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp);
140 static int segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len,
141 			uint_t behav);
142 static void segspt_shmdump(struct seg *seg);
143 static int segspt_shmpagelock(struct seg *, caddr_t, size_t,
144 			struct page ***, enum lock_type, enum seg_rw);
145 static int segspt_shmsetpgsz(struct seg *, caddr_t, size_t, uint_t);
146 static int segspt_shmgetmemid(struct seg *, caddr_t, memid_t *);
147 static lgrp_mem_policy_info_t *segspt_shmgetpolicy(struct seg *, caddr_t);
148 static int segspt_shmcapable(struct seg *, segcapability_t);
149 
150 struct seg_ops segspt_shmops = {
151 	segspt_shmdup,
152 	segspt_shmunmap,
153 	segspt_shmfree,
154 	segspt_shmfault,
155 	segspt_shmfaulta,
156 	segspt_shmsetprot,
157 	segspt_shmcheckprot,
158 	segspt_shmkluster,
159 	segspt_shmswapout,
160 	segspt_shmsync,
161 	segspt_shmincore,
162 	segspt_shmlockop,
163 	segspt_shmgetprot,
164 	segspt_shmgetoffset,
165 	segspt_shmgettype,
166 	segspt_shmgetvp,
167 	segspt_shmadvise,	/* advise */
168 	segspt_shmdump,
169 	segspt_shmpagelock,
170 	segspt_shmsetpgsz,
171 	segspt_shmgetmemid,
172 	segspt_shmgetpolicy,
173 	segspt_shmcapable,
174 };
175 
176 static void segspt_purge(struct seg *seg);
177 static int segspt_reclaim(void *, caddr_t, size_t, struct page **,
178 		enum seg_rw, int);
179 static int spt_anon_getpages(struct seg *seg, caddr_t addr, size_t len,
180 		page_t **ppa);
181 
182 
183 
184 /*ARGSUSED*/
185 int
186 sptcreate(size_t size, struct seg **sptseg, struct anon_map *amp,
187 	uint_t prot, uint_t flags, uint_t share_szc)
188 {
189 	int 	err;
190 	struct  as	*newas;
191 	struct	segspt_crargs sptcargs;
192 
193 #ifdef DEBUG
194 	TNF_PROBE_1(sptcreate, "spt", /* CSTYLED */,
195 			tnf_ulong, size, size );
196 #endif
197 	if (segspt_minfree == 0)	/* leave min 5% of availrmem for */
198 		segspt_minfree = availrmem/20;	/* for the system */
199 
200 	if (!hat_supported(HAT_SHARED_PT, (void *)0))
201 		return (EINVAL);
202 
203 	/*
204 	 * get a new as for this shared memory segment
205 	 */
206 	newas = as_alloc();
207 	newas->a_proc = NULL;
208 	sptcargs.amp = amp;
209 	sptcargs.prot = prot;
210 	sptcargs.flags = flags;
211 	sptcargs.szc = share_szc;
212 	/*
213 	 * create a shared page table (spt) segment
214 	 */
215 
216 	if (err = as_map(newas, SEGSPTADDR, size, segspt_create, &sptcargs)) {
217 		as_free(newas);
218 		return (err);
219 	}
220 	*sptseg = sptcargs.seg_spt;
221 	return (0);
222 }
223 
224 void
225 sptdestroy(struct as *as, struct anon_map *amp)
226 {
227 
228 #ifdef DEBUG
229 	TNF_PROBE_0(sptdestroy, "spt", /* CSTYLED */);
230 #endif
231 	(void) as_unmap(as, SEGSPTADDR, amp->size);
232 	as_free(as);
233 }
234 
235 /*
236  * called from seg_free().
237  * free (i.e., unlock, unmap, return to free list)
238  *  all the pages in the given seg.
239  */
240 void
241 segspt_free(struct seg	*seg)
242 {
243 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
244 
245 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
246 
247 	if (sptd != NULL) {
248 		if (sptd->spt_realsize)
249 			segspt_free_pages(seg, seg->s_base, sptd->spt_realsize);
250 
251 	if (sptd->spt_ppa_lckcnt)
252 		kmem_free(sptd->spt_ppa_lckcnt,
253 		    sizeof (*sptd->spt_ppa_lckcnt)
254 		    * btopr(sptd->spt_amp->size));
255 		kmem_free(sptd->spt_vp, sizeof (*sptd->spt_vp));
256 		cv_destroy(&sptd->spt_cv);
257 		mutex_destroy(&sptd->spt_lock);
258 		kmem_free(sptd, sizeof (*sptd));
259 	}
260 }
261 
262 /*ARGSUSED*/
263 static int
264 segspt_shmsync(struct seg *seg, caddr_t addr, size_t len, int attr,
265 	uint_t flags)
266 {
267 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
268 
269 	return (0);
270 }
271 
272 /*ARGSUSED*/
273 static size_t
274 segspt_shmincore(struct seg *seg, caddr_t addr, size_t len, char *vec)
275 {
276 	caddr_t	eo_seg;
277 	pgcnt_t	npages;
278 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
279 	struct seg	*sptseg;
280 	struct spt_data *sptd;
281 
282 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
283 #ifdef lint
284 	seg = seg;
285 #endif
286 	sptseg = shmd->shm_sptseg;
287 	sptd = sptseg->s_data;
288 
289 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
290 		eo_seg = addr + len;
291 		while (addr < eo_seg) {
292 			/* page exists, and it's locked. */
293 			*vec++ = SEG_PAGE_INCORE | SEG_PAGE_LOCKED |
294 			    SEG_PAGE_ANON;
295 			addr += PAGESIZE;
296 		}
297 		return (len);
298 	} else {
299 		struct  anon_map *amp = shmd->shm_amp;
300 		struct  anon	*ap;
301 		page_t		*pp;
302 		pgcnt_t 	anon_index;
303 		struct vnode 	*vp;
304 		u_offset_t 	off;
305 		ulong_t		i;
306 		int		ret;
307 		anon_sync_obj_t	cookie;
308 
309 		addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
310 		anon_index = seg_page(seg, addr);
311 		npages = btopr(len);
312 		if (anon_index + npages > btopr(shmd->shm_amp->size)) {
313 			return (EINVAL);
314 		}
315 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
316 		for (i = 0; i < npages; i++, anon_index++) {
317 			ret = 0;
318 			anon_array_enter(amp, anon_index, &cookie);
319 			ap = anon_get_ptr(amp->ahp, anon_index);
320 			if (ap != NULL) {
321 				swap_xlate(ap, &vp, &off);
322 				anon_array_exit(&cookie);
323 				pp = page_lookup_nowait(vp, off, SE_SHARED);
324 				if (pp != NULL) {
325 					ret |= SEG_PAGE_INCORE | SEG_PAGE_ANON;
326 					page_unlock(pp);
327 				}
328 			} else {
329 				anon_array_exit(&cookie);
330 			}
331 			if (shmd->shm_vpage[anon_index] & DISM_PG_LOCKED) {
332 				ret |= SEG_PAGE_LOCKED;
333 			}
334 			*vec++ = (char)ret;
335 		}
336 		ANON_LOCK_EXIT(&amp->a_rwlock);
337 		return (len);
338 	}
339 }
340 
341 static int
342 segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize)
343 {
344 	size_t share_size;
345 
346 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
347 
348 	/*
349 	 * seg.s_size may have been rounded up to the largest page size
350 	 * in shmat().
351 	 * XXX This should be cleanedup. sptdestroy should take a length
352 	 * argument which should be the same as sptcreate. Then
353 	 * this rounding would not be needed (or is done in shm.c)
354 	 * Only the check for full segment will be needed.
355 	 *
356 	 * XXX -- shouldn't raddr == 0 always? These tests don't seem
357 	 * to be useful at all.
358 	 */
359 	share_size = page_get_pagesize(seg->s_szc);
360 	ssize = P2ROUNDUP(ssize, share_size);
361 
362 	if (raddr == seg->s_base && ssize == seg->s_size) {
363 		seg_free(seg);
364 		return (0);
365 	} else
366 		return (EINVAL);
367 }
368 
369 int
370 segspt_create(struct seg *seg, caddr_t argsp)
371 {
372 	int		err;
373 	caddr_t		addr = seg->s_base;
374 	struct spt_data *sptd;
375 	struct 	segspt_crargs *sptcargs = (struct segspt_crargs *)argsp;
376 	struct anon_map *amp = sptcargs->amp;
377 	struct kshmid	*sp = amp->a_sp;
378 	struct	cred	*cred = CRED();
379 	ulong_t		i, j, anon_index = 0;
380 	pgcnt_t		npages = btopr(amp->size);
381 	struct vnode	*vp;
382 	page_t		**ppa;
383 	uint_t		hat_flags;
384 	size_t		pgsz;
385 	pgcnt_t		pgcnt;
386 	caddr_t		a;
387 	pgcnt_t		pidx;
388 	size_t		sz;
389 	proc_t		*procp = curproc;
390 	rctl_qty_t	lockedbytes = 0;
391 	kproject_t	*proj;
392 
393 	/*
394 	 * We are holding the a_lock on the underlying dummy as,
395 	 * so we can make calls to the HAT layer.
396 	 */
397 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
398 	ASSERT(sp != NULL);
399 
400 #ifdef DEBUG
401 	TNF_PROBE_2(segspt_create, "spt", /* CSTYLED */,
402 	    tnf_opaque, addr, addr, tnf_ulong, len, seg->s_size);
403 #endif
404 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
405 		if (err = anon_swap_adjust(npages))
406 			return (err);
407 	}
408 	err = ENOMEM;
409 
410 	if ((sptd = kmem_zalloc(sizeof (*sptd), KM_NOSLEEP)) == NULL)
411 		goto out1;
412 
413 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
414 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * npages),
415 		    KM_NOSLEEP)) == NULL)
416 			goto out2;
417 	}
418 
419 	mutex_init(&sptd->spt_lock, NULL, MUTEX_DEFAULT, NULL);
420 
421 	if ((vp = kmem_zalloc(sizeof (*vp), KM_NOSLEEP)) == NULL)
422 		goto out3;
423 
424 	seg->s_ops = &segspt_ops;
425 	sptd->spt_vp = vp;
426 	sptd->spt_amp = amp;
427 	sptd->spt_prot = sptcargs->prot;
428 	sptd->spt_flags = sptcargs->flags;
429 	seg->s_data = (caddr_t)sptd;
430 	sptd->spt_ppa = NULL;
431 	sptd->spt_ppa_lckcnt = NULL;
432 	seg->s_szc = sptcargs->szc;
433 	cv_init(&sptd->spt_cv, NULL, CV_DEFAULT, NULL);
434 	sptd->spt_gen = 0;
435 
436 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
437 	if (seg->s_szc > amp->a_szc) {
438 		amp->a_szc = seg->s_szc;
439 	}
440 	ANON_LOCK_EXIT(&amp->a_rwlock);
441 
442 	/*
443 	 * Set policy to affect initial allocation of pages in
444 	 * anon_map_createpages()
445 	 */
446 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, amp, anon_index,
447 	    NULL, 0, ptob(npages));
448 
449 	if (sptcargs->flags & SHM_PAGEABLE) {
450 		size_t  share_sz;
451 		pgcnt_t new_npgs, more_pgs;
452 		struct anon_hdr *nahp;
453 		zone_t *zone;
454 
455 		share_sz = page_get_pagesize(seg->s_szc);
456 		if (!IS_P2ALIGNED(amp->size, share_sz)) {
457 			/*
458 			 * We are rounding up the size of the anon array
459 			 * on 4 M boundary because we always create 4 M
460 			 * of page(s) when locking, faulting pages and we
461 			 * don't have to check for all corner cases e.g.
462 			 * if there is enough space to allocate 4 M
463 			 * page.
464 			 */
465 			new_npgs = btop(P2ROUNDUP(amp->size, share_sz));
466 			more_pgs = new_npgs - npages;
467 
468 			/*
469 			 * The zone will never be NULL, as a fully created
470 			 * shm always has an owning zone.
471 			 */
472 			zone = sp->shm_perm.ipc_zone;
473 			ASSERT(zone != NULL);
474 			if (anon_resv_zone(ptob(more_pgs), zone) == 0) {
475 				err = ENOMEM;
476 				goto out4;
477 			}
478 
479 			nahp = anon_create(new_npgs, ANON_SLEEP);
480 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
481 			(void) anon_copy_ptr(amp->ahp, 0, nahp, 0, npages,
482 			    ANON_SLEEP);
483 			anon_release(amp->ahp, npages);
484 			amp->ahp = nahp;
485 			ASSERT(amp->swresv == ptob(npages));
486 			amp->swresv = amp->size = ptob(new_npgs);
487 			ANON_LOCK_EXIT(&amp->a_rwlock);
488 			npages = new_npgs;
489 		}
490 
491 		sptd->spt_ppa_lckcnt = kmem_zalloc(npages *
492 		    sizeof (*sptd->spt_ppa_lckcnt), KM_SLEEP);
493 		sptd->spt_pcachecnt = 0;
494 		sptd->spt_realsize = ptob(npages);
495 		sptcargs->seg_spt = seg;
496 		return (0);
497 	}
498 
499 	/*
500 	 * get array of pages for each anon slot in amp
501 	 */
502 	if ((err = anon_map_createpages(amp, anon_index, ptob(npages), ppa,
503 	    seg, addr, S_CREATE, cred)) != 0)
504 		goto out4;
505 
506 	mutex_enter(&sp->shm_mlock);
507 
508 	/* May be partially locked, so, count bytes to charge for locking */
509 	for (i = 0; i < npages; i++)
510 		if (ppa[i]->p_lckcnt == 0)
511 			lockedbytes += PAGESIZE;
512 
513 	proj = sp->shm_perm.ipc_proj;
514 
515 	if (lockedbytes > 0) {
516 		mutex_enter(&procp->p_lock);
517 		if (rctl_incr_locked_mem(procp, proj, lockedbytes, 0)) {
518 			mutex_exit(&procp->p_lock);
519 			mutex_exit(&sp->shm_mlock);
520 			for (i = 0; i < npages; i++)
521 				page_unlock(ppa[i]);
522 			err = ENOMEM;
523 			goto out4;
524 		}
525 		mutex_exit(&procp->p_lock);
526 	}
527 
528 	/*
529 	 * addr is initial address corresponding to the first page on ppa list
530 	 */
531 	for (i = 0; i < npages; i++) {
532 		/* attempt to lock all pages */
533 		if (page_pp_lock(ppa[i], 0, 1) == 0) {
534 			/*
535 			 * if unable to lock any page, unlock all
536 			 * of them and return error
537 			 */
538 			for (j = 0; j < i; j++)
539 				page_pp_unlock(ppa[j], 0, 1);
540 			for (i = 0; i < npages; i++)
541 				page_unlock(ppa[i]);
542 			rctl_decr_locked_mem(NULL, proj, lockedbytes, 0);
543 			mutex_exit(&sp->shm_mlock);
544 			err = ENOMEM;
545 			goto out4;
546 		}
547 	}
548 	mutex_exit(&sp->shm_mlock);
549 
550 	/*
551 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
552 	 * for the entire life of the segment. For example platforms
553 	 * that do not support Dynamic Reconfiguration.
554 	 */
555 	hat_flags = HAT_LOAD_SHARE;
556 	if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, NULL))
557 		hat_flags |= HAT_LOAD_LOCK;
558 
559 	/*
560 	 * Load translations one lare page at a time
561 	 * to make sure we don't create mappings bigger than
562 	 * segment's size code in case underlying pages
563 	 * are shared with segvn's segment that uses bigger
564 	 * size code than we do.
565 	 */
566 	pgsz = page_get_pagesize(seg->s_szc);
567 	pgcnt = page_get_pagecnt(seg->s_szc);
568 	for (a = addr, pidx = 0; pidx < npages; a += pgsz, pidx += pgcnt) {
569 		sz = MIN(pgsz, ptob(npages - pidx));
570 		hat_memload_array(seg->s_as->a_hat, a, sz,
571 		    &ppa[pidx], sptd->spt_prot, hat_flags);
572 	}
573 
574 	/*
575 	 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
576 	 * we will leave the pages locked SE_SHARED for the life
577 	 * of the ISM segment. This will prevent any calls to
578 	 * hat_pageunload() on this ISM segment for those platforms.
579 	 */
580 	if (!(hat_flags & HAT_LOAD_LOCK)) {
581 		/*
582 		 * On platforms that support HAT_DYNAMIC_ISM_UNMAP,
583 		 * we no longer need to hold the SE_SHARED lock on the pages,
584 		 * since L_PAGELOCK and F_SOFTLOCK calls will grab the
585 		 * SE_SHARED lock on the pages as necessary.
586 		 */
587 		for (i = 0; i < npages; i++)
588 			page_unlock(ppa[i]);
589 	}
590 	sptd->spt_pcachecnt = 0;
591 	kmem_free(ppa, ((sizeof (page_t *)) * npages));
592 	sptd->spt_realsize = ptob(npages);
593 	atomic_add_long(&spt_used, npages);
594 	sptcargs->seg_spt = seg;
595 	return (0);
596 
597 out4:
598 	seg->s_data = NULL;
599 	kmem_free(vp, sizeof (*vp));
600 	cv_destroy(&sptd->spt_cv);
601 out3:
602 	mutex_destroy(&sptd->spt_lock);
603 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
604 		kmem_free(ppa, (sizeof (*ppa) * npages));
605 out2:
606 	kmem_free(sptd, sizeof (*sptd));
607 out1:
608 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
609 		anon_swap_restore(npages);
610 	return (err);
611 }
612 
613 /*ARGSUSED*/
614 void
615 segspt_free_pages(struct seg *seg, caddr_t addr, size_t len)
616 {
617 	struct page 	*pp;
618 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
619 	pgcnt_t		npages;
620 	ulong_t		anon_idx;
621 	struct anon_map *amp;
622 	struct anon 	*ap;
623 	struct vnode 	*vp;
624 	u_offset_t 	off;
625 	uint_t		hat_flags;
626 	int		root = 0;
627 	pgcnt_t		pgs, curnpgs = 0;
628 	page_t		*rootpp;
629 	rctl_qty_t	unlocked_bytes = 0;
630 	kproject_t	*proj;
631 	kshmid_t	*sp;
632 
633 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
634 
635 	len = P2ROUNDUP(len, PAGESIZE);
636 
637 	npages = btop(len);
638 
639 	hat_flags = HAT_UNLOAD_UNLOCK | HAT_UNLOAD_UNMAP;
640 	if ((hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) ||
641 	    (sptd->spt_flags & SHM_PAGEABLE)) {
642 		hat_flags = HAT_UNLOAD_UNMAP;
643 	}
644 
645 	hat_unload(seg->s_as->a_hat, addr, len, hat_flags);
646 
647 	amp = sptd->spt_amp;
648 	if (sptd->spt_flags & SHM_PAGEABLE)
649 		npages = btop(amp->size);
650 
651 	ASSERT(amp != NULL);
652 
653 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
654 		sp = amp->a_sp;
655 		proj = sp->shm_perm.ipc_proj;
656 		mutex_enter(&sp->shm_mlock);
657 	}
658 	for (anon_idx = 0; anon_idx < npages; anon_idx++) {
659 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
660 			if ((ap = anon_get_ptr(amp->ahp, anon_idx)) == NULL) {
661 				panic("segspt_free_pages: null app");
662 				/*NOTREACHED*/
663 			}
664 		} else {
665 			if ((ap = anon_get_next_ptr(amp->ahp, &anon_idx))
666 			    == NULL)
667 				continue;
668 		}
669 		ASSERT(ANON_ISBUSY(anon_get_slot(amp->ahp, anon_idx)) == 0);
670 		swap_xlate(ap, &vp, &off);
671 
672 		/*
673 		 * If this platform supports HAT_DYNAMIC_ISM_UNMAP,
674 		 * the pages won't be having SE_SHARED lock at this
675 		 * point.
676 		 *
677 		 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
678 		 * the pages are still held SE_SHARED locked from the
679 		 * original segspt_create()
680 		 *
681 		 * Our goal is to get SE_EXCL lock on each page, remove
682 		 * permanent lock on it and invalidate the page.
683 		 */
684 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
685 			if (hat_flags == HAT_UNLOAD_UNMAP)
686 				pp = page_lookup(vp, off, SE_EXCL);
687 			else {
688 				if ((pp = page_find(vp, off)) == NULL) {
689 					panic("segspt_free_pages: "
690 					    "page not locked");
691 					/*NOTREACHED*/
692 				}
693 				if (!page_tryupgrade(pp)) {
694 					page_unlock(pp);
695 					pp = page_lookup(vp, off, SE_EXCL);
696 				}
697 			}
698 			if (pp == NULL) {
699 				panic("segspt_free_pages: "
700 				    "page not in the system");
701 				/*NOTREACHED*/
702 			}
703 			ASSERT(pp->p_lckcnt > 0);
704 			page_pp_unlock(pp, 0, 1);
705 			if (pp->p_lckcnt == 0)
706 				unlocked_bytes += PAGESIZE;
707 		} else {
708 			if ((pp = page_lookup(vp, off, SE_EXCL)) == NULL)
709 				continue;
710 		}
711 		/*
712 		 * It's logical to invalidate the pages here as in most cases
713 		 * these were created by segspt.
714 		 */
715 		if (pp->p_szc != 0) {
716 			if (root == 0) {
717 				ASSERT(curnpgs == 0);
718 				root = 1;
719 				rootpp = pp;
720 				pgs = curnpgs = page_get_pagecnt(pp->p_szc);
721 				ASSERT(pgs > 1);
722 				ASSERT(IS_P2ALIGNED(pgs, pgs));
723 				ASSERT(!(page_pptonum(pp) & (pgs - 1)));
724 				curnpgs--;
725 			} else if ((page_pptonum(pp) & (pgs - 1)) == pgs - 1) {
726 				ASSERT(curnpgs == 1);
727 				ASSERT(page_pptonum(pp) ==
728 				    page_pptonum(rootpp) + (pgs - 1));
729 				page_destroy_pages(rootpp);
730 				root = 0;
731 				curnpgs = 0;
732 			} else {
733 				ASSERT(curnpgs > 1);
734 				ASSERT(page_pptonum(pp) ==
735 				    page_pptonum(rootpp) + (pgs - curnpgs));
736 				curnpgs--;
737 			}
738 		} else {
739 			if (root != 0 || curnpgs != 0) {
740 				panic("segspt_free_pages: bad large page");
741 				/*NOTREACHED*/
742 			}
743 			/*LINTED: constant in conditional context */
744 			VN_DISPOSE(pp, B_INVAL, 0, kcred);
745 		}
746 	}
747 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
748 		if (unlocked_bytes > 0)
749 			rctl_decr_locked_mem(NULL, proj, unlocked_bytes, 0);
750 		mutex_exit(&sp->shm_mlock);
751 	}
752 	if (root != 0 || curnpgs != 0) {
753 		panic("segspt_free_pages: bad large page");
754 		/*NOTREACHED*/
755 	}
756 
757 	/*
758 	 * mark that pages have been released
759 	 */
760 	sptd->spt_realsize = 0;
761 
762 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
763 		atomic_add_long(&spt_used, -npages);
764 		anon_swap_restore(npages);
765 	}
766 }
767 
768 /*
769  * Get memory allocation policy info for specified address in given segment
770  */
771 static lgrp_mem_policy_info_t *
772 segspt_getpolicy(struct seg *seg, caddr_t addr)
773 {
774 	struct anon_map		*amp;
775 	ulong_t			anon_index;
776 	lgrp_mem_policy_info_t	*policy_info;
777 	struct spt_data		*spt_data;
778 
779 	ASSERT(seg != NULL);
780 
781 	/*
782 	 * Get anon_map from segspt
783 	 *
784 	 * Assume that no lock needs to be held on anon_map, since
785 	 * it should be protected by its reference count which must be
786 	 * nonzero for an existing segment
787 	 * Need to grab readers lock on policy tree though
788 	 */
789 	spt_data = (struct spt_data *)seg->s_data;
790 	if (spt_data == NULL)
791 		return (NULL);
792 	amp = spt_data->spt_amp;
793 	ASSERT(amp->refcnt != 0);
794 
795 	/*
796 	 * Get policy info
797 	 *
798 	 * Assume starting anon index of 0
799 	 */
800 	anon_index = seg_page(seg, addr);
801 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
802 
803 	return (policy_info);
804 }
805 
806 /*
807  * DISM only.
808  * Return locked pages over a given range.
809  *
810  * We will cache all DISM locked pages and save the pplist for the
811  * entire segment in the ppa field of the underlying DISM segment structure.
812  * Later, during a call to segspt_reclaim() we will use this ppa array
813  * to page_unlock() all of the pages and then we will free this ppa list.
814  */
815 /*ARGSUSED*/
816 static int
817 segspt_dismpagelock(struct seg *seg, caddr_t addr, size_t len,
818     struct page ***ppp, enum lock_type type, enum seg_rw rw)
819 {
820 	struct  shm_data *shmd = (struct shm_data *)seg->s_data;
821 	struct  seg	*sptseg = shmd->shm_sptseg;
822 	struct  spt_data *sptd = sptseg->s_data;
823 	pgcnt_t pg_idx, npages, tot_npages, npgs;
824 	struct  page **pplist, **pl, **ppa, *pp;
825 	struct  anon_map *amp;
826 	spgcnt_t	an_idx;
827 	int 	ret = ENOTSUP;
828 	uint_t	pl_built = 0;
829 	struct  anon *ap;
830 	struct  vnode *vp;
831 	u_offset_t off;
832 	pgcnt_t claim_availrmem = 0;
833 	uint_t	szc;
834 
835 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
836 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
837 
838 	/*
839 	 * We want to lock/unlock the entire ISM segment. Therefore,
840 	 * we will be using the underlying sptseg and it's base address
841 	 * and length for the caching arguments.
842 	 */
843 	ASSERT(sptseg);
844 	ASSERT(sptd);
845 
846 	pg_idx = seg_page(seg, addr);
847 	npages = btopr(len);
848 
849 	/*
850 	 * check if the request is larger than number of pages covered
851 	 * by amp
852 	 */
853 	if (pg_idx + npages > btopr(sptd->spt_amp->size)) {
854 		*ppp = NULL;
855 		return (ENOTSUP);
856 	}
857 
858 	if (type == L_PAGEUNLOCK) {
859 		ASSERT(sptd->spt_ppa != NULL);
860 
861 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
862 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
863 
864 		/*
865 		 * If someone is blocked while unmapping, we purge
866 		 * segment page cache and thus reclaim pplist synchronously
867 		 * without waiting for seg_pasync_thread. This speeds up
868 		 * unmapping in cases where munmap(2) is called, while
869 		 * raw async i/o is still in progress or where a thread
870 		 * exits on data fault in a multithreaded application.
871 		 */
872 		if ((sptd->spt_flags & DISM_PPA_CHANGED) ||
873 		    (AS_ISUNMAPWAIT(seg->s_as) &&
874 		    shmd->shm_softlockcnt > 0)) {
875 			segspt_purge(seg);
876 		}
877 		return (0);
878 	}
879 
880 	/* The L_PAGELOCK case ... */
881 
882 	if (sptd->spt_flags & DISM_PPA_CHANGED) {
883 		segspt_purge(seg);
884 		/*
885 		 * for DISM ppa needs to be rebuild since
886 		 * number of locked pages could be changed
887 		 */
888 		*ppp = NULL;
889 		return (ENOTSUP);
890 	}
891 
892 	/*
893 	 * First try to find pages in segment page cache, without
894 	 * holding the segment lock.
895 	 */
896 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
897 	    S_WRITE, SEGP_FORCE_WIRED);
898 	if (pplist != NULL) {
899 		ASSERT(sptd->spt_ppa != NULL);
900 		ASSERT(sptd->spt_ppa == pplist);
901 		ppa = sptd->spt_ppa;
902 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
903 			if (ppa[an_idx] == NULL) {
904 				seg_pinactive(seg, NULL, seg->s_base,
905 				    sptd->spt_amp->size, ppa,
906 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
907 				*ppp = NULL;
908 				return (ENOTSUP);
909 			}
910 			if ((szc = ppa[an_idx]->p_szc) != 0) {
911 				npgs = page_get_pagecnt(szc);
912 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
913 			} else {
914 				an_idx++;
915 			}
916 		}
917 		/*
918 		 * Since we cache the entire DISM segment, we want to
919 		 * set ppp to point to the first slot that corresponds
920 		 * to the requested addr, i.e. pg_idx.
921 		 */
922 		*ppp = &(sptd->spt_ppa[pg_idx]);
923 		return (0);
924 	}
925 
926 	mutex_enter(&sptd->spt_lock);
927 	/*
928 	 * try to find pages in segment page cache with mutex
929 	 */
930 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
931 	    S_WRITE, SEGP_FORCE_WIRED);
932 	if (pplist != NULL) {
933 		ASSERT(sptd->spt_ppa != NULL);
934 		ASSERT(sptd->spt_ppa == pplist);
935 		ppa = sptd->spt_ppa;
936 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
937 			if (ppa[an_idx] == NULL) {
938 				mutex_exit(&sptd->spt_lock);
939 				seg_pinactive(seg, NULL, seg->s_base,
940 				    sptd->spt_amp->size, ppa,
941 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
942 				*ppp = NULL;
943 				return (ENOTSUP);
944 			}
945 			if ((szc = ppa[an_idx]->p_szc) != 0) {
946 				npgs = page_get_pagecnt(szc);
947 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
948 			} else {
949 				an_idx++;
950 			}
951 		}
952 		/*
953 		 * Since we cache the entire DISM segment, we want to
954 		 * set ppp to point to the first slot that corresponds
955 		 * to the requested addr, i.e. pg_idx.
956 		 */
957 		mutex_exit(&sptd->spt_lock);
958 		*ppp = &(sptd->spt_ppa[pg_idx]);
959 		return (0);
960 	}
961 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
962 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
963 		mutex_exit(&sptd->spt_lock);
964 		*ppp = NULL;
965 		return (ENOTSUP);
966 	}
967 
968 	/*
969 	 * No need to worry about protections because DISM pages are always rw.
970 	 */
971 	pl = pplist = NULL;
972 	amp = sptd->spt_amp;
973 
974 	/*
975 	 * Do we need to build the ppa array?
976 	 */
977 	if (sptd->spt_ppa == NULL) {
978 		pgcnt_t lpg_cnt = 0;
979 
980 		pl_built = 1;
981 		tot_npages = btopr(sptd->spt_amp->size);
982 
983 		ASSERT(sptd->spt_pcachecnt == 0);
984 		pplist = kmem_zalloc(sizeof (page_t *) * tot_npages, KM_SLEEP);
985 		pl = pplist;
986 
987 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
988 		for (an_idx = 0; an_idx < tot_npages; ) {
989 			ap = anon_get_ptr(amp->ahp, an_idx);
990 			/*
991 			 * Cache only mlocked pages. For large pages
992 			 * if one (constituent) page is mlocked
993 			 * all pages for that large page
994 			 * are cached also. This is for quick
995 			 * lookups of ppa array;
996 			 */
997 			if ((ap != NULL) && (lpg_cnt != 0 ||
998 			    (sptd->spt_ppa_lckcnt[an_idx] != 0))) {
999 
1000 				swap_xlate(ap, &vp, &off);
1001 				pp = page_lookup(vp, off, SE_SHARED);
1002 				ASSERT(pp != NULL);
1003 				if (lpg_cnt == 0) {
1004 					lpg_cnt++;
1005 					/*
1006 					 * For a small page, we are done --
1007 					 * lpg_count is reset to 0 below.
1008 					 *
1009 					 * For a large page, we are guaranteed
1010 					 * to find the anon structures of all
1011 					 * constituent pages and a non-zero
1012 					 * lpg_cnt ensures that we don't test
1013 					 * for mlock for these. We are done
1014 					 * when lpg_count reaches (npgs + 1).
1015 					 * If we are not the first constituent
1016 					 * page, restart at the first one.
1017 					 */
1018 					npgs = page_get_pagecnt(pp->p_szc);
1019 					if (!IS_P2ALIGNED(an_idx, npgs)) {
1020 						an_idx = P2ALIGN(an_idx, npgs);
1021 						page_unlock(pp);
1022 						continue;
1023 					}
1024 				}
1025 				if (++lpg_cnt > npgs)
1026 					lpg_cnt = 0;
1027 
1028 				/*
1029 				 * availrmem is decremented only
1030 				 * for unlocked pages
1031 				 */
1032 				if (sptd->spt_ppa_lckcnt[an_idx] == 0)
1033 					claim_availrmem++;
1034 				pplist[an_idx] = pp;
1035 			}
1036 			an_idx++;
1037 		}
1038 		ANON_LOCK_EXIT(&amp->a_rwlock);
1039 
1040 		if (claim_availrmem) {
1041 			mutex_enter(&freemem_lock);
1042 			if (availrmem < tune.t_minarmem + claim_availrmem) {
1043 				mutex_exit(&freemem_lock);
1044 				ret = ENOTSUP;
1045 				claim_availrmem = 0;
1046 				goto insert_fail;
1047 			} else {
1048 				availrmem -= claim_availrmem;
1049 			}
1050 			mutex_exit(&freemem_lock);
1051 		}
1052 
1053 		sptd->spt_ppa = pl;
1054 	} else {
1055 		/*
1056 		 * We already have a valid ppa[].
1057 		 */
1058 		pl = sptd->spt_ppa;
1059 	}
1060 
1061 	ASSERT(pl != NULL);
1062 
1063 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1064 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1065 	    segspt_reclaim);
1066 	if (ret == SEGP_FAIL) {
1067 		/*
1068 		 * seg_pinsert failed. We return
1069 		 * ENOTSUP, so that the as_pagelock() code will
1070 		 * then try the slower F_SOFTLOCK path.
1071 		 */
1072 		if (pl_built) {
1073 			/*
1074 			 * No one else has referenced the ppa[].
1075 			 * We created it and we need to destroy it.
1076 			 */
1077 			sptd->spt_ppa = NULL;
1078 		}
1079 		ret = ENOTSUP;
1080 		goto insert_fail;
1081 	}
1082 
1083 	/*
1084 	 * In either case, we increment softlockcnt on the 'real' segment.
1085 	 */
1086 	sptd->spt_pcachecnt++;
1087 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), 1);
1088 
1089 	ppa = sptd->spt_ppa;
1090 	for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
1091 		if (ppa[an_idx] == NULL) {
1092 			mutex_exit(&sptd->spt_lock);
1093 			seg_pinactive(seg, NULL, seg->s_base,
1094 			    sptd->spt_amp->size,
1095 			    pl, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1096 			*ppp = NULL;
1097 			return (ENOTSUP);
1098 		}
1099 		if ((szc = ppa[an_idx]->p_szc) != 0) {
1100 			npgs = page_get_pagecnt(szc);
1101 			an_idx = P2ROUNDUP(an_idx + 1, npgs);
1102 		} else {
1103 			an_idx++;
1104 		}
1105 	}
1106 	/*
1107 	 * We can now drop the sptd->spt_lock since the ppa[]
1108 	 * exists and he have incremented pacachecnt.
1109 	 */
1110 	mutex_exit(&sptd->spt_lock);
1111 
1112 	/*
1113 	 * Since we cache the entire segment, we want to
1114 	 * set ppp to point to the first slot that corresponds
1115 	 * to the requested addr, i.e. pg_idx.
1116 	 */
1117 	*ppp = &(sptd->spt_ppa[pg_idx]);
1118 	return (0);
1119 
1120 insert_fail:
1121 	/*
1122 	 * We will only reach this code if we tried and failed.
1123 	 *
1124 	 * And we can drop the lock on the dummy seg, once we've failed
1125 	 * to set up a new ppa[].
1126 	 */
1127 	mutex_exit(&sptd->spt_lock);
1128 
1129 	if (pl_built) {
1130 		if (claim_availrmem) {
1131 			mutex_enter(&freemem_lock);
1132 			availrmem += claim_availrmem;
1133 			mutex_exit(&freemem_lock);
1134 		}
1135 
1136 		/*
1137 		 * We created pl and we need to destroy it.
1138 		 */
1139 		pplist = pl;
1140 		for (an_idx = 0; an_idx < tot_npages; an_idx++) {
1141 			if (pplist[an_idx] != NULL)
1142 				page_unlock(pplist[an_idx]);
1143 		}
1144 		kmem_free(pl, sizeof (page_t *) * tot_npages);
1145 	}
1146 
1147 	if (shmd->shm_softlockcnt <= 0) {
1148 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1149 			mutex_enter(&seg->s_as->a_contents);
1150 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1151 				AS_CLRUNMAPWAIT(seg->s_as);
1152 				cv_broadcast(&seg->s_as->a_cv);
1153 			}
1154 			mutex_exit(&seg->s_as->a_contents);
1155 		}
1156 	}
1157 	*ppp = NULL;
1158 	return (ret);
1159 }
1160 
1161 
1162 
1163 /*
1164  * return locked pages over a given range.
1165  *
1166  * We will cache the entire ISM segment and save the pplist for the
1167  * entire segment in the ppa field of the underlying ISM segment structure.
1168  * Later, during a call to segspt_reclaim() we will use this ppa array
1169  * to page_unlock() all of the pages and then we will free this ppa list.
1170  */
1171 /*ARGSUSED*/
1172 static int
1173 segspt_shmpagelock(struct seg *seg, caddr_t addr, size_t len,
1174     struct page ***ppp, enum lock_type type, enum seg_rw rw)
1175 {
1176 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1177 	struct seg	*sptseg = shmd->shm_sptseg;
1178 	struct spt_data *sptd = sptseg->s_data;
1179 	pgcnt_t np, page_index, npages;
1180 	caddr_t a, spt_base;
1181 	struct page **pplist, **pl, *pp;
1182 	struct anon_map *amp;
1183 	ulong_t anon_index;
1184 	int ret = ENOTSUP;
1185 	uint_t	pl_built = 0;
1186 	struct anon *ap;
1187 	struct vnode *vp;
1188 	u_offset_t off;
1189 
1190 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1191 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
1192 
1193 
1194 	/*
1195 	 * We want to lock/unlock the entire ISM segment. Therefore,
1196 	 * we will be using the underlying sptseg and it's base address
1197 	 * and length for the caching arguments.
1198 	 */
1199 	ASSERT(sptseg);
1200 	ASSERT(sptd);
1201 
1202 	if (sptd->spt_flags & SHM_PAGEABLE) {
1203 		return (segspt_dismpagelock(seg, addr, len, ppp, type, rw));
1204 	}
1205 
1206 	page_index = seg_page(seg, addr);
1207 	npages = btopr(len);
1208 
1209 	/*
1210 	 * check if the request is larger than number of pages covered
1211 	 * by amp
1212 	 */
1213 	if (page_index + npages > btopr(sptd->spt_amp->size)) {
1214 		*ppp = NULL;
1215 		return (ENOTSUP);
1216 	}
1217 
1218 	if (type == L_PAGEUNLOCK) {
1219 
1220 		ASSERT(sptd->spt_ppa != NULL);
1221 
1222 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
1223 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1224 
1225 		/*
1226 		 * If someone is blocked while unmapping, we purge
1227 		 * segment page cache and thus reclaim pplist synchronously
1228 		 * without waiting for seg_pasync_thread. This speeds up
1229 		 * unmapping in cases where munmap(2) is called, while
1230 		 * raw async i/o is still in progress or where a thread
1231 		 * exits on data fault in a multithreaded application.
1232 		 */
1233 		if (AS_ISUNMAPWAIT(seg->s_as) && (shmd->shm_softlockcnt > 0)) {
1234 			segspt_purge(seg);
1235 		}
1236 		return (0);
1237 	}
1238 
1239 	/* The L_PAGELOCK case... */
1240 
1241 	/*
1242 	 * First try to find pages in segment page cache, without
1243 	 * holding the segment lock.
1244 	 */
1245 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1246 	    S_WRITE, SEGP_FORCE_WIRED);
1247 	if (pplist != NULL) {
1248 		ASSERT(sptd->spt_ppa == pplist);
1249 		ASSERT(sptd->spt_ppa[page_index]);
1250 		/*
1251 		 * Since we cache the entire ISM segment, we want to
1252 		 * set ppp to point to the first slot that corresponds
1253 		 * to the requested addr, i.e. page_index.
1254 		 */
1255 		*ppp = &(sptd->spt_ppa[page_index]);
1256 		return (0);
1257 	}
1258 
1259 	mutex_enter(&sptd->spt_lock);
1260 
1261 	/*
1262 	 * try to find pages in segment page cache
1263 	 */
1264 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1265 	    S_WRITE, SEGP_FORCE_WIRED);
1266 	if (pplist != NULL) {
1267 		ASSERT(sptd->spt_ppa == pplist);
1268 		/*
1269 		 * Since we cache the entire segment, we want to
1270 		 * set ppp to point to the first slot that corresponds
1271 		 * to the requested addr, i.e. page_index.
1272 		 */
1273 		mutex_exit(&sptd->spt_lock);
1274 		*ppp = &(sptd->spt_ppa[page_index]);
1275 		return (0);
1276 	}
1277 
1278 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
1279 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
1280 		mutex_exit(&sptd->spt_lock);
1281 		*ppp = NULL;
1282 		return (ENOTSUP);
1283 	}
1284 
1285 	/*
1286 	 * No need to worry about protections because ISM pages
1287 	 * are always rw.
1288 	 */
1289 	pl = pplist = NULL;
1290 
1291 	/*
1292 	 * Do we need to build the ppa array?
1293 	 */
1294 	if (sptd->spt_ppa == NULL) {
1295 		ASSERT(sptd->spt_ppa == pplist);
1296 
1297 		spt_base = sptseg->s_base;
1298 		pl_built = 1;
1299 
1300 		/*
1301 		 * availrmem is decremented once during anon_swap_adjust()
1302 		 * and is incremented during the anon_unresv(), which is
1303 		 * called from shm_rm_amp() when the segment is destroyed.
1304 		 */
1305 		amp = sptd->spt_amp;
1306 		ASSERT(amp != NULL);
1307 
1308 		/* pcachecnt is protected by sptd->spt_lock */
1309 		ASSERT(sptd->spt_pcachecnt == 0);
1310 		pplist = kmem_zalloc(sizeof (page_t *)
1311 		    * btopr(sptd->spt_amp->size), KM_SLEEP);
1312 		pl = pplist;
1313 
1314 		anon_index = seg_page(sptseg, spt_base);
1315 
1316 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1317 		for (a = spt_base; a < (spt_base + sptd->spt_amp->size);
1318 		    a += PAGESIZE, anon_index++, pplist++) {
1319 			ap = anon_get_ptr(amp->ahp, anon_index);
1320 			ASSERT(ap != NULL);
1321 			swap_xlate(ap, &vp, &off);
1322 			pp = page_lookup(vp, off, SE_SHARED);
1323 			ASSERT(pp != NULL);
1324 			*pplist = pp;
1325 		}
1326 		ANON_LOCK_EXIT(&amp->a_rwlock);
1327 
1328 		if (a < (spt_base + sptd->spt_amp->size)) {
1329 			ret = ENOTSUP;
1330 			goto insert_fail;
1331 		}
1332 		sptd->spt_ppa = pl;
1333 	} else {
1334 		/*
1335 		 * We already have a valid ppa[].
1336 		 */
1337 		pl = sptd->spt_ppa;
1338 	}
1339 
1340 	ASSERT(pl != NULL);
1341 
1342 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1343 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1344 	    segspt_reclaim);
1345 	if (ret == SEGP_FAIL) {
1346 		/*
1347 		 * seg_pinsert failed. We return
1348 		 * ENOTSUP, so that the as_pagelock() code will
1349 		 * then try the slower F_SOFTLOCK path.
1350 		 */
1351 		if (pl_built) {
1352 			/*
1353 			 * No one else has referenced the ppa[].
1354 			 * We created it and we need to destroy it.
1355 			 */
1356 			sptd->spt_ppa = NULL;
1357 		}
1358 		ret = ENOTSUP;
1359 		goto insert_fail;
1360 	}
1361 
1362 	/*
1363 	 * In either case, we increment softlockcnt on the 'real' segment.
1364 	 */
1365 	sptd->spt_pcachecnt++;
1366 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), 1);
1367 
1368 	/*
1369 	 * We can now drop the sptd->spt_lock since the ppa[]
1370 	 * exists and he have incremented pacachecnt.
1371 	 */
1372 	mutex_exit(&sptd->spt_lock);
1373 
1374 	/*
1375 	 * Since we cache the entire segment, we want to
1376 	 * set ppp to point to the first slot that corresponds
1377 	 * to the requested addr, i.e. page_index.
1378 	 */
1379 	*ppp = &(sptd->spt_ppa[page_index]);
1380 	return (0);
1381 
1382 insert_fail:
1383 	/*
1384 	 * We will only reach this code if we tried and failed.
1385 	 *
1386 	 * And we can drop the lock on the dummy seg, once we've failed
1387 	 * to set up a new ppa[].
1388 	 */
1389 	mutex_exit(&sptd->spt_lock);
1390 
1391 	if (pl_built) {
1392 		/*
1393 		 * We created pl and we need to destroy it.
1394 		 */
1395 		pplist = pl;
1396 		np = (((uintptr_t)(a - spt_base)) >> PAGESHIFT);
1397 		while (np) {
1398 			page_unlock(*pplist);
1399 			np--;
1400 			pplist++;
1401 		}
1402 		kmem_free(pl, sizeof (page_t *) * btopr(sptd->spt_amp->size));
1403 	}
1404 	if (shmd->shm_softlockcnt <= 0) {
1405 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1406 			mutex_enter(&seg->s_as->a_contents);
1407 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1408 				AS_CLRUNMAPWAIT(seg->s_as);
1409 				cv_broadcast(&seg->s_as->a_cv);
1410 			}
1411 			mutex_exit(&seg->s_as->a_contents);
1412 		}
1413 	}
1414 	*ppp = NULL;
1415 	return (ret);
1416 }
1417 
1418 /*
1419  * purge any cached pages in the I/O page cache
1420  */
1421 static void
1422 segspt_purge(struct seg *seg)
1423 {
1424 	seg_ppurge(seg, NULL, SEGP_FORCE_WIRED);
1425 }
1426 
1427 static int
1428 segspt_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
1429 	enum seg_rw rw, int async)
1430 {
1431 	struct seg *seg = (struct seg *)ptag;
1432 	struct	shm_data *shmd = (struct shm_data *)seg->s_data;
1433 	struct	seg	*sptseg;
1434 	struct	spt_data *sptd;
1435 	pgcnt_t npages, i, free_availrmem = 0;
1436 	int	done = 0;
1437 
1438 #ifdef lint
1439 	addr = addr;
1440 #endif
1441 	sptseg = shmd->shm_sptseg;
1442 	sptd = sptseg->s_data;
1443 	npages = (len >> PAGESHIFT);
1444 	ASSERT(npages);
1445 	ASSERT(sptd->spt_pcachecnt != 0);
1446 	ASSERT(sptd->spt_ppa == pplist);
1447 	ASSERT(npages == btopr(sptd->spt_amp->size));
1448 	ASSERT(async || AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1449 
1450 	/*
1451 	 * Acquire the lock on the dummy seg and destroy the
1452 	 * ppa array IF this is the last pcachecnt.
1453 	 */
1454 	mutex_enter(&sptd->spt_lock);
1455 	if (--sptd->spt_pcachecnt == 0) {
1456 		for (i = 0; i < npages; i++) {
1457 			if (pplist[i] == NULL) {
1458 				continue;
1459 			}
1460 			if (rw == S_WRITE) {
1461 				hat_setrefmod(pplist[i]);
1462 			} else {
1463 				hat_setref(pplist[i]);
1464 			}
1465 			if ((sptd->spt_flags & SHM_PAGEABLE) &&
1466 			    (sptd->spt_ppa_lckcnt[i] == 0))
1467 				free_availrmem++;
1468 			page_unlock(pplist[i]);
1469 		}
1470 		if ((sptd->spt_flags & SHM_PAGEABLE) && free_availrmem) {
1471 			mutex_enter(&freemem_lock);
1472 			availrmem += free_availrmem;
1473 			mutex_exit(&freemem_lock);
1474 		}
1475 		/*
1476 		 * Since we want to cach/uncache the entire ISM segment,
1477 		 * we will track the pplist in a segspt specific field
1478 		 * ppa, that is initialized at the time we add an entry to
1479 		 * the cache.
1480 		 */
1481 		ASSERT(sptd->spt_pcachecnt == 0);
1482 		kmem_free(pplist, sizeof (page_t *) * npages);
1483 		sptd->spt_ppa = NULL;
1484 		sptd->spt_flags &= ~DISM_PPA_CHANGED;
1485 		sptd->spt_gen++;
1486 		cv_broadcast(&sptd->spt_cv);
1487 		done = 1;
1488 	}
1489 	mutex_exit(&sptd->spt_lock);
1490 
1491 	/*
1492 	 * If we are pcache async thread or called via seg_ppurge_wiredpp() we
1493 	 * may not hold AS lock (in this case async argument is not 0). This
1494 	 * means if softlockcnt drops to 0 after the decrement below address
1495 	 * space may get freed. We can't allow it since after softlock
1496 	 * derement to 0 we still need to access as structure for possible
1497 	 * wakeup of unmap waiters. To prevent the disappearance of as we take
1498 	 * this segment's shm_segfree_syncmtx. segspt_shmfree() also takes
1499 	 * this mutex as a barrier to make sure this routine completes before
1500 	 * segment is freed.
1501 	 *
1502 	 * The second complication we have to deal with in async case is a
1503 	 * possibility of missed wake up of unmap wait thread. When we don't
1504 	 * hold as lock here we may take a_contents lock before unmap wait
1505 	 * thread that was first to see softlockcnt was still not 0. As a
1506 	 * result we'll fail to wake up an unmap wait thread. To avoid this
1507 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
1508 	 * to 0 if async is not 0.  unmapwait thread
1509 	 * will not block if this flag is set.
1510 	 */
1511 	if (async)
1512 		mutex_enter(&shmd->shm_segfree_syncmtx);
1513 
1514 	/*
1515 	 * Now decrement softlockcnt.
1516 	 */
1517 	ASSERT(shmd->shm_softlockcnt > 0);
1518 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -1);
1519 
1520 	if (shmd->shm_softlockcnt <= 0) {
1521 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
1522 			mutex_enter(&seg->s_as->a_contents);
1523 			if (async)
1524 				AS_SETNOUNMAPWAIT(seg->s_as);
1525 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1526 				AS_CLRUNMAPWAIT(seg->s_as);
1527 				cv_broadcast(&seg->s_as->a_cv);
1528 			}
1529 			mutex_exit(&seg->s_as->a_contents);
1530 		}
1531 	}
1532 
1533 	if (async)
1534 		mutex_exit(&shmd->shm_segfree_syncmtx);
1535 
1536 	return (done);
1537 }
1538 
1539 /*
1540  * Do a F_SOFTUNLOCK call over the range requested.
1541  * The range must have already been F_SOFTLOCK'ed.
1542  *
1543  * The calls to acquire and release the anon map lock mutex were
1544  * removed in order to avoid a deadly embrace during a DR
1545  * memory delete operation.  (Eg. DR blocks while waiting for a
1546  * exclusive lock on a page that is being used for kaio; the
1547  * thread that will complete the kaio and call segspt_softunlock
1548  * blocks on the anon map lock; another thread holding the anon
1549  * map lock blocks on another page lock via the segspt_shmfault
1550  * -> page_lookup -> page_lookup_create -> page_lock_es code flow.)
1551  *
1552  * The appropriateness of the removal is based upon the following:
1553  * 1. If we are holding a segment's reader lock and the page is held
1554  * shared, then the corresponding element in anonmap which points to
1555  * anon struct cannot change and there is no need to acquire the
1556  * anonymous map lock.
1557  * 2. Threads in segspt_softunlock have a reader lock on the segment
1558  * and already have the shared page lock, so we are guaranteed that
1559  * the anon map slot cannot change and therefore can call anon_get_ptr()
1560  * without grabbing the anonymous map lock.
1561  * 3. Threads that softlock a shared page break copy-on-write, even if
1562  * its a read.  Thus cow faults can be ignored with respect to soft
1563  * unlocking, since the breaking of cow means that the anon slot(s) will
1564  * not be shared.
1565  */
1566 static void
1567 segspt_softunlock(struct seg *seg, caddr_t sptseg_addr,
1568 	size_t len, enum seg_rw rw)
1569 {
1570 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1571 	struct seg	*sptseg;
1572 	struct spt_data *sptd;
1573 	page_t *pp;
1574 	caddr_t adr;
1575 	struct vnode *vp;
1576 	u_offset_t offset;
1577 	ulong_t anon_index;
1578 	struct anon_map *amp;		/* XXX - for locknest */
1579 	struct anon *ap = NULL;
1580 	pgcnt_t npages;
1581 
1582 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1583 
1584 	sptseg = shmd->shm_sptseg;
1585 	sptd = sptseg->s_data;
1586 
1587 	/*
1588 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
1589 	 * and therefore their pages are SE_SHARED locked
1590 	 * for the entire life of the segment.
1591 	 */
1592 	if ((!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) &&
1593 	    ((sptd->spt_flags & SHM_PAGEABLE) == 0)) {
1594 		goto softlock_decrement;
1595 	}
1596 
1597 	/*
1598 	 * Any thread is free to do a page_find and
1599 	 * page_unlock() on the pages within this seg.
1600 	 *
1601 	 * We are already holding the as->a_lock on the user's
1602 	 * real segment, but we need to hold the a_lock on the
1603 	 * underlying dummy as. This is mostly to satisfy the
1604 	 * underlying HAT layer.
1605 	 */
1606 	AS_LOCK_ENTER(sptseg->s_as, &sptseg->s_as->a_lock, RW_READER);
1607 	hat_unlock(sptseg->s_as->a_hat, sptseg_addr, len);
1608 	AS_LOCK_EXIT(sptseg->s_as, &sptseg->s_as->a_lock);
1609 
1610 	amp = sptd->spt_amp;
1611 	ASSERT(amp != NULL);
1612 	anon_index = seg_page(sptseg, sptseg_addr);
1613 
1614 	for (adr = sptseg_addr; adr < sptseg_addr + len; adr += PAGESIZE) {
1615 		ap = anon_get_ptr(amp->ahp, anon_index++);
1616 		ASSERT(ap != NULL);
1617 		swap_xlate(ap, &vp, &offset);
1618 
1619 		/*
1620 		 * Use page_find() instead of page_lookup() to
1621 		 * find the page since we know that it has a
1622 		 * "shared" lock.
1623 		 */
1624 		pp = page_find(vp, offset);
1625 		ASSERT(ap == anon_get_ptr(amp->ahp, anon_index - 1));
1626 		if (pp == NULL) {
1627 			panic("segspt_softunlock: "
1628 			    "addr %p, ap %p, vp %p, off %llx",
1629 			    (void *)adr, (void *)ap, (void *)vp, offset);
1630 			/*NOTREACHED*/
1631 		}
1632 
1633 		if (rw == S_WRITE) {
1634 			hat_setrefmod(pp);
1635 		} else if (rw != S_OTHER) {
1636 			hat_setref(pp);
1637 		}
1638 		page_unlock(pp);
1639 	}
1640 
1641 softlock_decrement:
1642 	npages = btopr(len);
1643 	ASSERT(shmd->shm_softlockcnt >= npages);
1644 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -npages);
1645 	if (shmd->shm_softlockcnt == 0) {
1646 		/*
1647 		 * All SOFTLOCKS are gone. Wakeup any waiting
1648 		 * unmappers so they can try again to unmap.
1649 		 * Check for waiters first without the mutex
1650 		 * held so we don't always grab the mutex on
1651 		 * softunlocks.
1652 		 */
1653 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1654 			mutex_enter(&seg->s_as->a_contents);
1655 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1656 				AS_CLRUNMAPWAIT(seg->s_as);
1657 				cv_broadcast(&seg->s_as->a_cv);
1658 			}
1659 			mutex_exit(&seg->s_as->a_contents);
1660 		}
1661 	}
1662 }
1663 
1664 int
1665 segspt_shmattach(struct seg *seg, caddr_t *argsp)
1666 {
1667 	struct shm_data *shmd_arg = (struct shm_data *)argsp;
1668 	struct shm_data *shmd;
1669 	struct anon_map *shm_amp = shmd_arg->shm_amp;
1670 	struct spt_data *sptd;
1671 	int error = 0;
1672 
1673 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1674 
1675 	shmd = kmem_zalloc((sizeof (*shmd)), KM_NOSLEEP);
1676 	if (shmd == NULL)
1677 		return (ENOMEM);
1678 
1679 	shmd->shm_sptas = shmd_arg->shm_sptas;
1680 	shmd->shm_amp = shm_amp;
1681 	shmd->shm_sptseg = shmd_arg->shm_sptseg;
1682 
1683 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, shm_amp, 0,
1684 	    NULL, 0, seg->s_size);
1685 
1686 	mutex_init(&shmd->shm_segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
1687 
1688 	seg->s_data = (void *)shmd;
1689 	seg->s_ops = &segspt_shmops;
1690 	seg->s_szc = shmd->shm_sptseg->s_szc;
1691 	sptd = shmd->shm_sptseg->s_data;
1692 
1693 	if (sptd->spt_flags & SHM_PAGEABLE) {
1694 		if ((shmd->shm_vpage = kmem_zalloc(btopr(shm_amp->size),
1695 		    KM_NOSLEEP)) == NULL) {
1696 			seg->s_data = (void *)NULL;
1697 			kmem_free(shmd, (sizeof (*shmd)));
1698 			return (ENOMEM);
1699 		}
1700 		shmd->shm_lckpgs = 0;
1701 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
1702 			if ((error = hat_share(seg->s_as->a_hat, seg->s_base,
1703 			    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1704 			    seg->s_size, seg->s_szc)) != 0) {
1705 				kmem_free(shmd->shm_vpage,
1706 				    btopr(shm_amp->size));
1707 			}
1708 		}
1709 	} else {
1710 		error = hat_share(seg->s_as->a_hat, seg->s_base,
1711 		    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1712 		    seg->s_size, seg->s_szc);
1713 	}
1714 	if (error) {
1715 		seg->s_szc = 0;
1716 		seg->s_data = (void *)NULL;
1717 		kmem_free(shmd, (sizeof (*shmd)));
1718 	} else {
1719 		ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1720 		shm_amp->refcnt++;
1721 		ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1722 	}
1723 	return (error);
1724 }
1725 
1726 int
1727 segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize)
1728 {
1729 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1730 	int reclaim = 1;
1731 
1732 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1733 retry:
1734 	if (shmd->shm_softlockcnt > 0) {
1735 		if (reclaim == 1) {
1736 			segspt_purge(seg);
1737 			reclaim = 0;
1738 			goto retry;
1739 		}
1740 		return (EAGAIN);
1741 	}
1742 
1743 	if (ssize != seg->s_size) {
1744 #ifdef DEBUG
1745 		cmn_err(CE_WARN, "Incompatible ssize %lx s_size %lx\n",
1746 		    ssize, seg->s_size);
1747 #endif
1748 		return (EINVAL);
1749 	}
1750 
1751 	(void) segspt_shmlockop(seg, raddr, shmd->shm_amp->size, 0, MC_UNLOCK,
1752 	    NULL, 0);
1753 	hat_unshare(seg->s_as->a_hat, raddr, ssize, seg->s_szc);
1754 
1755 	seg_free(seg);
1756 
1757 	return (0);
1758 }
1759 
1760 void
1761 segspt_shmfree(struct seg *seg)
1762 {
1763 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1764 	struct anon_map *shm_amp = shmd->shm_amp;
1765 
1766 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1767 
1768 	(void) segspt_shmlockop(seg, seg->s_base, shm_amp->size, 0,
1769 	    MC_UNLOCK, NULL, 0);
1770 
1771 	/*
1772 	 * Need to increment refcnt when attaching
1773 	 * and decrement when detaching because of dup().
1774 	 */
1775 	ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1776 	shm_amp->refcnt--;
1777 	ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1778 
1779 	if (shmd->shm_vpage) {	/* only for DISM */
1780 		kmem_free(shmd->shm_vpage, btopr(shm_amp->size));
1781 		shmd->shm_vpage = NULL;
1782 	}
1783 
1784 	/*
1785 	 * Take shm_segfree_syncmtx lock to let segspt_reclaim() finish if it's
1786 	 * still working with this segment without holding as lock.
1787 	 */
1788 	ASSERT(shmd->shm_softlockcnt == 0);
1789 	mutex_enter(&shmd->shm_segfree_syncmtx);
1790 	mutex_destroy(&shmd->shm_segfree_syncmtx);
1791 
1792 	kmem_free(shmd, sizeof (*shmd));
1793 }
1794 
1795 /*ARGSUSED*/
1796 int
1797 segspt_shmsetprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
1798 {
1799 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1800 
1801 	/*
1802 	 * Shared page table is more than shared mapping.
1803 	 *  Individual process sharing page tables can't change prot
1804 	 *  because there is only one set of page tables.
1805 	 *  This will be allowed after private page table is
1806 	 *  supported.
1807 	 */
1808 /* need to return correct status error? */
1809 	return (0);
1810 }
1811 
1812 
1813 faultcode_t
1814 segspt_dismfault(struct hat *hat, struct seg *seg, caddr_t addr,
1815     size_t len, enum fault_type type, enum seg_rw rw)
1816 {
1817 	struct  shm_data 	*shmd = (struct shm_data *)seg->s_data;
1818 	struct  seg		*sptseg = shmd->shm_sptseg;
1819 	struct  as		*curspt = shmd->shm_sptas;
1820 	struct  spt_data 	*sptd = sptseg->s_data;
1821 	pgcnt_t npages;
1822 	size_t  size;
1823 	caddr_t segspt_addr, shm_addr;
1824 	page_t  **ppa;
1825 	int	i;
1826 	ulong_t an_idx = 0;
1827 	int	err = 0;
1828 	int	dyn_ism_unmap = hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0);
1829 	size_t	pgsz;
1830 	pgcnt_t	pgcnt;
1831 	caddr_t	a;
1832 	pgcnt_t	pidx;
1833 
1834 #ifdef lint
1835 	hat = hat;
1836 #endif
1837 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
1838 
1839 	/*
1840 	 * Because of the way spt is implemented
1841 	 * the realsize of the segment does not have to be
1842 	 * equal to the segment size itself. The segment size is
1843 	 * often in multiples of a page size larger than PAGESIZE.
1844 	 * The realsize is rounded up to the nearest PAGESIZE
1845 	 * based on what the user requested. This is a bit of
1846 	 * ungliness that is historical but not easily fixed
1847 	 * without re-designing the higher levels of ISM.
1848 	 */
1849 	ASSERT(addr >= seg->s_base);
1850 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
1851 		return (FC_NOMAP);
1852 	/*
1853 	 * For all of the following cases except F_PROT, we need to
1854 	 * make any necessary adjustments to addr and len
1855 	 * and get all of the necessary page_t's into an array called ppa[].
1856 	 *
1857 	 * The code in shmat() forces base addr and len of ISM segment
1858 	 * to be aligned to largest page size supported. Therefore,
1859 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
1860 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
1861 	 * in large pagesize chunks, or else we will screw up the HAT
1862 	 * layer by calling hat_memload_array() with differing page sizes
1863 	 * over a given virtual range.
1864 	 */
1865 	pgsz = page_get_pagesize(sptseg->s_szc);
1866 	pgcnt = page_get_pagecnt(sptseg->s_szc);
1867 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
1868 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
1869 	npages = btopr(size);
1870 
1871 	/*
1872 	 * Now we need to convert from addr in segshm to addr in segspt.
1873 	 */
1874 	an_idx = seg_page(seg, shm_addr);
1875 	segspt_addr = sptseg->s_base + ptob(an_idx);
1876 
1877 	ASSERT((segspt_addr + ptob(npages)) <=
1878 	    (sptseg->s_base + sptd->spt_realsize));
1879 	ASSERT(segspt_addr < (sptseg->s_base + sptseg->s_size));
1880 
1881 	switch (type) {
1882 
1883 	case F_SOFTLOCK:
1884 
1885 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
1886 		/*
1887 		 * Fall through to the F_INVAL case to load up the hat layer
1888 		 * entries with the HAT_LOAD_LOCK flag.
1889 		 */
1890 		/* FALLTHRU */
1891 	case F_INVAL:
1892 
1893 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
1894 			return (FC_NOMAP);
1895 
1896 		ppa = kmem_zalloc(npages * sizeof (page_t *), KM_SLEEP);
1897 
1898 		err = spt_anon_getpages(sptseg, segspt_addr, size, ppa);
1899 		if (err != 0) {
1900 			if (type == F_SOFTLOCK) {
1901 				atomic_add_long((ulong_t *)(
1902 				    &(shmd->shm_softlockcnt)), -npages);
1903 			}
1904 			goto dism_err;
1905 		}
1906 		AS_LOCK_ENTER(sptseg->s_as, &sptseg->s_as->a_lock, RW_READER);
1907 		a = segspt_addr;
1908 		pidx = 0;
1909 		if (type == F_SOFTLOCK) {
1910 
1911 			/*
1912 			 * Load up the translation keeping it
1913 			 * locked and don't unlock the page.
1914 			 */
1915 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
1916 				hat_memload_array(sptseg->s_as->a_hat,
1917 				    a, pgsz, &ppa[pidx], sptd->spt_prot,
1918 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
1919 			}
1920 		} else {
1921 			if (hat == seg->s_as->a_hat) {
1922 
1923 				/*
1924 				 * Migrate pages marked for migration
1925 				 */
1926 				if (lgrp_optimizations())
1927 					page_migrate(seg, shm_addr, ppa,
1928 					    npages);
1929 
1930 				/* CPU HAT */
1931 				for (; pidx < npages;
1932 				    a += pgsz, pidx += pgcnt) {
1933 					hat_memload_array(sptseg->s_as->a_hat,
1934 					    a, pgsz, &ppa[pidx],
1935 					    sptd->spt_prot,
1936 					    HAT_LOAD_SHARE);
1937 				}
1938 			} else {
1939 				/* XHAT. Pass real address */
1940 				hat_memload_array(hat, shm_addr,
1941 				    size, ppa, sptd->spt_prot, HAT_LOAD_SHARE);
1942 			}
1943 
1944 			/*
1945 			 * And now drop the SE_SHARED lock(s).
1946 			 */
1947 			if (dyn_ism_unmap) {
1948 				for (i = 0; i < npages; i++) {
1949 					page_unlock(ppa[i]);
1950 				}
1951 			}
1952 		}
1953 
1954 		if (!dyn_ism_unmap) {
1955 			if (hat_share(seg->s_as->a_hat, shm_addr,
1956 			    curspt->a_hat, segspt_addr, ptob(npages),
1957 			    seg->s_szc) != 0) {
1958 				panic("hat_share err in DISM fault");
1959 				/* NOTREACHED */
1960 			}
1961 			if (type == F_INVAL) {
1962 				for (i = 0; i < npages; i++) {
1963 					page_unlock(ppa[i]);
1964 				}
1965 			}
1966 		}
1967 		AS_LOCK_EXIT(sptseg->s_as, &sptseg->s_as->a_lock);
1968 dism_err:
1969 		kmem_free(ppa, npages * sizeof (page_t *));
1970 		return (err);
1971 
1972 	case F_SOFTUNLOCK:
1973 
1974 		/*
1975 		 * This is a bit ugly, we pass in the real seg pointer,
1976 		 * but the segspt_addr is the virtual address within the
1977 		 * dummy seg.
1978 		 */
1979 		segspt_softunlock(seg, segspt_addr, size, rw);
1980 		return (0);
1981 
1982 	case F_PROT:
1983 
1984 		/*
1985 		 * This takes care of the unusual case where a user
1986 		 * allocates a stack in shared memory and a register
1987 		 * window overflow is written to that stack page before
1988 		 * it is otherwise modified.
1989 		 *
1990 		 * We can get away with this because ISM segments are
1991 		 * always rw. Other than this unusual case, there
1992 		 * should be no instances of protection violations.
1993 		 */
1994 		return (0);
1995 
1996 	default:
1997 #ifdef DEBUG
1998 		panic("segspt_dismfault default type?");
1999 #else
2000 		return (FC_NOMAP);
2001 #endif
2002 	}
2003 }
2004 
2005 
2006 faultcode_t
2007 segspt_shmfault(struct hat *hat, struct seg *seg, caddr_t addr,
2008     size_t len, enum fault_type type, enum seg_rw rw)
2009 {
2010 	struct shm_data 	*shmd = (struct shm_data *)seg->s_data;
2011 	struct seg		*sptseg = shmd->shm_sptseg;
2012 	struct as		*curspt = shmd->shm_sptas;
2013 	struct spt_data 	*sptd   = sptseg->s_data;
2014 	pgcnt_t npages;
2015 	size_t size;
2016 	caddr_t sptseg_addr, shm_addr;
2017 	page_t *pp, **ppa;
2018 	int	i;
2019 	u_offset_t offset;
2020 	ulong_t anon_index = 0;
2021 	struct vnode *vp;
2022 	struct anon_map *amp;		/* XXX - for locknest */
2023 	struct anon *ap = NULL;
2024 	size_t		pgsz;
2025 	pgcnt_t		pgcnt;
2026 	caddr_t		a;
2027 	pgcnt_t		pidx;
2028 	size_t		sz;
2029 
2030 #ifdef lint
2031 	hat = hat;
2032 #endif
2033 
2034 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2035 
2036 	if (sptd->spt_flags & SHM_PAGEABLE) {
2037 		return (segspt_dismfault(hat, seg, addr, len, type, rw));
2038 	}
2039 
2040 	/*
2041 	 * Because of the way spt is implemented
2042 	 * the realsize of the segment does not have to be
2043 	 * equal to the segment size itself. The segment size is
2044 	 * often in multiples of a page size larger than PAGESIZE.
2045 	 * The realsize is rounded up to the nearest PAGESIZE
2046 	 * based on what the user requested. This is a bit of
2047 	 * ungliness that is historical but not easily fixed
2048 	 * without re-designing the higher levels of ISM.
2049 	 */
2050 	ASSERT(addr >= seg->s_base);
2051 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
2052 		return (FC_NOMAP);
2053 	/*
2054 	 * For all of the following cases except F_PROT, we need to
2055 	 * make any necessary adjustments to addr and len
2056 	 * and get all of the necessary page_t's into an array called ppa[].
2057 	 *
2058 	 * The code in shmat() forces base addr and len of ISM segment
2059 	 * to be aligned to largest page size supported. Therefore,
2060 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
2061 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
2062 	 * in large pagesize chunks, or else we will screw up the HAT
2063 	 * layer by calling hat_memload_array() with differing page sizes
2064 	 * over a given virtual range.
2065 	 */
2066 	pgsz = page_get_pagesize(sptseg->s_szc);
2067 	pgcnt = page_get_pagecnt(sptseg->s_szc);
2068 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
2069 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
2070 	npages = btopr(size);
2071 
2072 	/*
2073 	 * Now we need to convert from addr in segshm to addr in segspt.
2074 	 */
2075 	anon_index = seg_page(seg, shm_addr);
2076 	sptseg_addr = sptseg->s_base + ptob(anon_index);
2077 
2078 	/*
2079 	 * And now we may have to adjust npages downward if we have
2080 	 * exceeded the realsize of the segment or initial anon
2081 	 * allocations.
2082 	 */
2083 	if ((sptseg_addr + ptob(npages)) >
2084 	    (sptseg->s_base + sptd->spt_realsize))
2085 		size = (sptseg->s_base + sptd->spt_realsize) - sptseg_addr;
2086 
2087 	npages = btopr(size);
2088 
2089 	ASSERT(sptseg_addr < (sptseg->s_base + sptseg->s_size));
2090 	ASSERT((sptd->spt_flags & SHM_PAGEABLE) == 0);
2091 
2092 	switch (type) {
2093 
2094 	case F_SOFTLOCK:
2095 
2096 		/*
2097 		 * availrmem is decremented once during anon_swap_adjust()
2098 		 * and is incremented during the anon_unresv(), which is
2099 		 * called from shm_rm_amp() when the segment is destroyed.
2100 		 */
2101 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
2102 		/*
2103 		 * Some platforms assume that ISM pages are SE_SHARED
2104 		 * locked for the entire life of the segment.
2105 		 */
2106 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0))
2107 			return (0);
2108 		/*
2109 		 * Fall through to the F_INVAL case to load up the hat layer
2110 		 * entries with the HAT_LOAD_LOCK flag.
2111 		 */
2112 
2113 		/* FALLTHRU */
2114 	case F_INVAL:
2115 
2116 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
2117 			return (FC_NOMAP);
2118 
2119 		/*
2120 		 * Some platforms that do NOT support DYNAMIC_ISM_UNMAP
2121 		 * may still rely on this call to hat_share(). That
2122 		 * would imply that those hat's can fault on a
2123 		 * HAT_LOAD_LOCK translation, which would seem
2124 		 * contradictory.
2125 		 */
2126 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2127 			if (hat_share(seg->s_as->a_hat, seg->s_base,
2128 			    curspt->a_hat, sptseg->s_base,
2129 			    sptseg->s_size, sptseg->s_szc) != 0) {
2130 				panic("hat_share error in ISM fault");
2131 				/*NOTREACHED*/
2132 			}
2133 			return (0);
2134 		}
2135 		ppa = kmem_zalloc(sizeof (page_t *) * npages, KM_SLEEP);
2136 
2137 		/*
2138 		 * I see no need to lock the real seg,
2139 		 * here, because all of our work will be on the underlying
2140 		 * dummy seg.
2141 		 *
2142 		 * sptseg_addr and npages now account for large pages.
2143 		 */
2144 		amp = sptd->spt_amp;
2145 		ASSERT(amp != NULL);
2146 		anon_index = seg_page(sptseg, sptseg_addr);
2147 
2148 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2149 		for (i = 0; i < npages; i++) {
2150 			ap = anon_get_ptr(amp->ahp, anon_index++);
2151 			ASSERT(ap != NULL);
2152 			swap_xlate(ap, &vp, &offset);
2153 			pp = page_lookup(vp, offset, SE_SHARED);
2154 			ASSERT(pp != NULL);
2155 			ppa[i] = pp;
2156 		}
2157 		ANON_LOCK_EXIT(&amp->a_rwlock);
2158 		ASSERT(i == npages);
2159 
2160 		/*
2161 		 * We are already holding the as->a_lock on the user's
2162 		 * real segment, but we need to hold the a_lock on the
2163 		 * underlying dummy as. This is mostly to satisfy the
2164 		 * underlying HAT layer.
2165 		 */
2166 		AS_LOCK_ENTER(sptseg->s_as, &sptseg->s_as->a_lock, RW_READER);
2167 		a = sptseg_addr;
2168 		pidx = 0;
2169 		if (type == F_SOFTLOCK) {
2170 			/*
2171 			 * Load up the translation keeping it
2172 			 * locked and don't unlock the page.
2173 			 */
2174 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
2175 				sz = MIN(pgsz, ptob(npages - pidx));
2176 				hat_memload_array(sptseg->s_as->a_hat, a,
2177 				    sz, &ppa[pidx], sptd->spt_prot,
2178 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
2179 			}
2180 		} else {
2181 			if (hat == seg->s_as->a_hat) {
2182 
2183 				/*
2184 				 * Migrate pages marked for migration.
2185 				 */
2186 				if (lgrp_optimizations())
2187 					page_migrate(seg, shm_addr, ppa,
2188 					    npages);
2189 
2190 				/* CPU HAT */
2191 				for (; pidx < npages;
2192 				    a += pgsz, pidx += pgcnt) {
2193 					sz = MIN(pgsz, ptob(npages - pidx));
2194 					hat_memload_array(sptseg->s_as->a_hat,
2195 					    a, sz, &ppa[pidx],
2196 					    sptd->spt_prot, HAT_LOAD_SHARE);
2197 				}
2198 			} else {
2199 				/* XHAT. Pass real address */
2200 				hat_memload_array(hat, shm_addr,
2201 				    ptob(npages), ppa, sptd->spt_prot,
2202 				    HAT_LOAD_SHARE);
2203 			}
2204 
2205 			/*
2206 			 * And now drop the SE_SHARED lock(s).
2207 			 */
2208 			for (i = 0; i < npages; i++)
2209 				page_unlock(ppa[i]);
2210 		}
2211 		AS_LOCK_EXIT(sptseg->s_as, &sptseg->s_as->a_lock);
2212 
2213 		kmem_free(ppa, sizeof (page_t *) * npages);
2214 		return (0);
2215 	case F_SOFTUNLOCK:
2216 
2217 		/*
2218 		 * This is a bit ugly, we pass in the real seg pointer,
2219 		 * but the sptseg_addr is the virtual address within the
2220 		 * dummy seg.
2221 		 */
2222 		segspt_softunlock(seg, sptseg_addr, ptob(npages), rw);
2223 		return (0);
2224 
2225 	case F_PROT:
2226 
2227 		/*
2228 		 * This takes care of the unusual case where a user
2229 		 * allocates a stack in shared memory and a register
2230 		 * window overflow is written to that stack page before
2231 		 * it is otherwise modified.
2232 		 *
2233 		 * We can get away with this because ISM segments are
2234 		 * always rw. Other than this unusual case, there
2235 		 * should be no instances of protection violations.
2236 		 */
2237 		return (0);
2238 
2239 	default:
2240 #ifdef DEBUG
2241 		cmn_err(CE_WARN, "segspt_shmfault default type?");
2242 #endif
2243 		return (FC_NOMAP);
2244 	}
2245 }
2246 
2247 /*ARGSUSED*/
2248 static faultcode_t
2249 segspt_shmfaulta(struct seg *seg, caddr_t addr)
2250 {
2251 	return (0);
2252 }
2253 
2254 /*ARGSUSED*/
2255 static int
2256 segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta)
2257 {
2258 	return (0);
2259 }
2260 
2261 /*ARGSUSED*/
2262 static size_t
2263 segspt_shmswapout(struct seg *seg)
2264 {
2265 	return (0);
2266 }
2267 
2268 /*
2269  * duplicate the shared page tables
2270  */
2271 int
2272 segspt_shmdup(struct seg *seg, struct seg *newseg)
2273 {
2274 	struct shm_data		*shmd = (struct shm_data *)seg->s_data;
2275 	struct anon_map 	*amp = shmd->shm_amp;
2276 	struct shm_data 	*shmd_new;
2277 	struct seg		*spt_seg = shmd->shm_sptseg;
2278 	struct spt_data		*sptd = spt_seg->s_data;
2279 	int			error = 0;
2280 
2281 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
2282 
2283 	shmd_new = kmem_zalloc((sizeof (*shmd_new)), KM_SLEEP);
2284 	newseg->s_data = (void *)shmd_new;
2285 	shmd_new->shm_sptas = shmd->shm_sptas;
2286 	shmd_new->shm_amp = amp;
2287 	shmd_new->shm_sptseg = shmd->shm_sptseg;
2288 	newseg->s_ops = &segspt_shmops;
2289 	newseg->s_szc = seg->s_szc;
2290 	ASSERT(seg->s_szc == shmd->shm_sptseg->s_szc);
2291 
2292 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2293 	amp->refcnt++;
2294 	ANON_LOCK_EXIT(&amp->a_rwlock);
2295 
2296 	if (sptd->spt_flags & SHM_PAGEABLE) {
2297 		shmd_new->shm_vpage = kmem_zalloc(btopr(amp->size), KM_SLEEP);
2298 		shmd_new->shm_lckpgs = 0;
2299 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2300 			if ((error = hat_share(newseg->s_as->a_hat,
2301 			    newseg->s_base, shmd->shm_sptas->a_hat, SEGSPTADDR,
2302 			    seg->s_size, seg->s_szc)) != 0) {
2303 				kmem_free(shmd_new->shm_vpage,
2304 				    btopr(amp->size));
2305 			}
2306 		}
2307 		return (error);
2308 	} else {
2309 		return (hat_share(newseg->s_as->a_hat, newseg->s_base,
2310 		    shmd->shm_sptas->a_hat, SEGSPTADDR, seg->s_size,
2311 		    seg->s_szc));
2312 
2313 	}
2314 }
2315 
2316 /*ARGSUSED*/
2317 int
2318 segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size, uint_t prot)
2319 {
2320 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2321 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2322 
2323 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2324 
2325 	/*
2326 	 * ISM segment is always rw.
2327 	 */
2328 	return (((sptd->spt_prot & prot) != prot) ? EACCES : 0);
2329 }
2330 
2331 /*
2332  * Return an array of locked large pages, for empty slots allocate
2333  * private zero-filled anon pages.
2334  */
2335 static int
2336 spt_anon_getpages(
2337 	struct seg *sptseg,
2338 	caddr_t sptaddr,
2339 	size_t len,
2340 	page_t *ppa[])
2341 {
2342 	struct  spt_data *sptd = sptseg->s_data;
2343 	struct  anon_map *amp = sptd->spt_amp;
2344 	enum 	seg_rw rw = sptd->spt_prot;
2345 	uint_t	szc = sptseg->s_szc;
2346 	size_t	pg_sz, share_sz = page_get_pagesize(szc);
2347 	pgcnt_t	lp_npgs;
2348 	caddr_t	lp_addr, e_sptaddr;
2349 	uint_t	vpprot, ppa_szc = 0;
2350 	struct  vpage *vpage = NULL;
2351 	ulong_t	j, ppa_idx;
2352 	int	err, ierr = 0;
2353 	pgcnt_t	an_idx;
2354 	anon_sync_obj_t cookie;
2355 	int anon_locked = 0;
2356 	pgcnt_t amp_pgs;
2357 
2358 
2359 	ASSERT(IS_P2ALIGNED(sptaddr, share_sz) && IS_P2ALIGNED(len, share_sz));
2360 	ASSERT(len != 0);
2361 
2362 	pg_sz = share_sz;
2363 	lp_npgs = btop(pg_sz);
2364 	lp_addr = sptaddr;
2365 	e_sptaddr = sptaddr + len;
2366 	an_idx = seg_page(sptseg, sptaddr);
2367 	ppa_idx = 0;
2368 
2369 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2370 
2371 	amp_pgs = page_get_pagecnt(amp->a_szc);
2372 
2373 	/*CONSTCOND*/
2374 	while (1) {
2375 		for (; lp_addr < e_sptaddr;
2376 		    an_idx += lp_npgs, lp_addr += pg_sz, ppa_idx += lp_npgs) {
2377 
2378 			/*
2379 			 * If we're currently locked, and we get to a new
2380 			 * page, unlock our current anon chunk.
2381 			 */
2382 			if (anon_locked && P2PHASE(an_idx, amp_pgs) == 0) {
2383 				anon_array_exit(&cookie);
2384 				anon_locked = 0;
2385 			}
2386 			if (!anon_locked) {
2387 				anon_array_enter(amp, an_idx, &cookie);
2388 				anon_locked = 1;
2389 			}
2390 			ppa_szc = (uint_t)-1;
2391 			ierr = anon_map_getpages(amp, an_idx, szc, sptseg,
2392 			    lp_addr, sptd->spt_prot, &vpprot, &ppa[ppa_idx],
2393 			    &ppa_szc, vpage, rw, 0, segvn_anypgsz, 0, kcred);
2394 
2395 			if (ierr != 0) {
2396 				if (ierr > 0) {
2397 					err = FC_MAKE_ERR(ierr);
2398 					goto lpgs_err;
2399 				}
2400 				break;
2401 			}
2402 		}
2403 		if (lp_addr == e_sptaddr) {
2404 			break;
2405 		}
2406 		ASSERT(lp_addr < e_sptaddr);
2407 
2408 		/*
2409 		 * ierr == -1 means we failed to allocate a large page.
2410 		 * so do a size down operation.
2411 		 *
2412 		 * ierr == -2 means some other process that privately shares
2413 		 * pages with this process has allocated a larger page and we
2414 		 * need to retry with larger pages. So do a size up
2415 		 * operation. This relies on the fact that large pages are
2416 		 * never partially shared i.e. if we share any constituent
2417 		 * page of a large page with another process we must share the
2418 		 * entire large page. Note this cannot happen for SOFTLOCK
2419 		 * case, unless current address (lpaddr) is at the beginning
2420 		 * of the next page size boundary because the other process
2421 		 * couldn't have relocated locked pages.
2422 		 */
2423 		ASSERT(ierr == -1 || ierr == -2);
2424 		if (segvn_anypgsz) {
2425 			ASSERT(ierr == -2 || szc != 0);
2426 			ASSERT(ierr == -1 || szc < sptseg->s_szc);
2427 			szc = (ierr == -1) ? szc - 1 : szc + 1;
2428 		} else {
2429 			/*
2430 			 * For faults and segvn_anypgsz == 0
2431 			 * we need to be careful not to loop forever
2432 			 * if existing page is found with szc other
2433 			 * than 0 or seg->s_szc. This could be due
2434 			 * to page relocations on behalf of DR or
2435 			 * more likely large page creation. For this
2436 			 * case simply re-size to existing page's szc
2437 			 * if returned by anon_map_getpages().
2438 			 */
2439 			if (ppa_szc == (uint_t)-1) {
2440 				szc = (ierr == -1) ? 0 : sptseg->s_szc;
2441 			} else {
2442 				ASSERT(ppa_szc <= sptseg->s_szc);
2443 				ASSERT(ierr == -2 || ppa_szc < szc);
2444 				ASSERT(ierr == -1 || ppa_szc > szc);
2445 				szc = ppa_szc;
2446 			}
2447 		}
2448 		pg_sz = page_get_pagesize(szc);
2449 		lp_npgs = btop(pg_sz);
2450 		ASSERT(IS_P2ALIGNED(lp_addr, pg_sz));
2451 	}
2452 	if (anon_locked) {
2453 		anon_array_exit(&cookie);
2454 	}
2455 	ANON_LOCK_EXIT(&amp->a_rwlock);
2456 	return (0);
2457 
2458 lpgs_err:
2459 	if (anon_locked) {
2460 		anon_array_exit(&cookie);
2461 	}
2462 	ANON_LOCK_EXIT(&amp->a_rwlock);
2463 	for (j = 0; j < ppa_idx; j++)
2464 		page_unlock(ppa[j]);
2465 	return (err);
2466 }
2467 
2468 /*
2469  * count the number of bytes in a set of spt pages that are currently not
2470  * locked
2471  */
2472 static rctl_qty_t
2473 spt_unlockedbytes(pgcnt_t npages, page_t **ppa)
2474 {
2475 	ulong_t	i;
2476 	rctl_qty_t unlocked = 0;
2477 
2478 	for (i = 0; i < npages; i++) {
2479 		if (ppa[i]->p_lckcnt == 0)
2480 			unlocked += PAGESIZE;
2481 	}
2482 	return (unlocked);
2483 }
2484 
2485 int
2486 spt_lockpages(struct seg *seg, pgcnt_t anon_index, pgcnt_t npages,
2487     page_t **ppa, ulong_t *lockmap, size_t pos,
2488     rctl_qty_t *locked)
2489 {
2490 	struct shm_data *shmd = seg->s_data;
2491 	struct spt_data *sptd = shmd->shm_sptseg->s_data;
2492 	ulong_t	i;
2493 	int	kernel;
2494 
2495 	/* return the number of bytes actually locked */
2496 	*locked = 0;
2497 	for (i = 0; i < npages; anon_index++, pos++, i++) {
2498 		if (!(shmd->shm_vpage[anon_index] & DISM_PG_LOCKED)) {
2499 			if (sptd->spt_ppa_lckcnt[anon_index] <
2500 			    (ushort_t)DISM_LOCK_MAX) {
2501 				if (++sptd->spt_ppa_lckcnt[anon_index] ==
2502 				    (ushort_t)DISM_LOCK_MAX) {
2503 					cmn_err(CE_WARN,
2504 					    "DISM page lock limit "
2505 					    "reached on DISM offset 0x%lx\n",
2506 					    anon_index << PAGESHIFT);
2507 				}
2508 				kernel = (sptd->spt_ppa &&
2509 				    sptd->spt_ppa[anon_index]) ? 1 : 0;
2510 				if (!page_pp_lock(ppa[i], 0, kernel)) {
2511 					sptd->spt_ppa_lckcnt[anon_index]--;
2512 					return (EAGAIN);
2513 				}
2514 				/* if this is a newly locked page, count it */
2515 				if (ppa[i]->p_lckcnt == 1) {
2516 					*locked += PAGESIZE;
2517 				}
2518 				shmd->shm_lckpgs++;
2519 				shmd->shm_vpage[anon_index] |= DISM_PG_LOCKED;
2520 				if (lockmap != NULL)
2521 					BT_SET(lockmap, pos);
2522 			}
2523 		}
2524 	}
2525 	return (0);
2526 }
2527 
2528 /*ARGSUSED*/
2529 static int
2530 segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
2531     int attr, int op, ulong_t *lockmap, size_t pos)
2532 {
2533 	struct shm_data *shmd = seg->s_data;
2534 	struct seg	*sptseg = shmd->shm_sptseg;
2535 	struct spt_data *sptd = sptseg->s_data;
2536 	struct kshmid	*sp = sptd->spt_amp->a_sp;
2537 	pgcnt_t		npages, a_npages;
2538 	page_t		**ppa;
2539 	pgcnt_t 	an_idx, a_an_idx, ppa_idx;
2540 	caddr_t		spt_addr, a_addr;	/* spt and aligned address */
2541 	size_t		a_len;			/* aligned len */
2542 	size_t		share_sz;
2543 	ulong_t		i;
2544 	int		sts = 0;
2545 	rctl_qty_t	unlocked = 0;
2546 	rctl_qty_t	locked = 0;
2547 	struct proc	*p = curproc;
2548 	kproject_t	*proj;
2549 
2550 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2551 	ASSERT(sp != NULL);
2552 
2553 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
2554 		return (0);
2555 	}
2556 
2557 	addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2558 	an_idx = seg_page(seg, addr);
2559 	npages = btopr(len);
2560 
2561 	if (an_idx + npages > btopr(shmd->shm_amp->size)) {
2562 		return (ENOMEM);
2563 	}
2564 
2565 	/*
2566 	 * A shm's project never changes, so no lock needed.
2567 	 * The shm has a hold on the project, so it will not go away.
2568 	 * Since we have a mapping to shm within this zone, we know
2569 	 * that the zone will not go away.
2570 	 */
2571 	proj = sp->shm_perm.ipc_proj;
2572 
2573 	if (op == MC_LOCK) {
2574 
2575 		/*
2576 		 * Need to align addr and size request if they are not
2577 		 * aligned so we can always allocate large page(s) however
2578 		 * we only lock what was requested in initial request.
2579 		 */
2580 		share_sz = page_get_pagesize(sptseg->s_szc);
2581 		a_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_sz);
2582 		a_len = P2ROUNDUP((uintptr_t)(((addr + len) - a_addr)),
2583 		    share_sz);
2584 		a_npages = btop(a_len);
2585 		a_an_idx = seg_page(seg, a_addr);
2586 		spt_addr = sptseg->s_base + ptob(a_an_idx);
2587 		ppa_idx = an_idx - a_an_idx;
2588 
2589 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * a_npages),
2590 		    KM_NOSLEEP)) == NULL) {
2591 			return (ENOMEM);
2592 		}
2593 
2594 		/*
2595 		 * Don't cache any new pages for IO and
2596 		 * flush any cached pages.
2597 		 */
2598 		mutex_enter(&sptd->spt_lock);
2599 		if (sptd->spt_ppa != NULL)
2600 			sptd->spt_flags |= DISM_PPA_CHANGED;
2601 
2602 		sts = spt_anon_getpages(sptseg, spt_addr, a_len, ppa);
2603 		if (sts != 0) {
2604 			mutex_exit(&sptd->spt_lock);
2605 			kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2606 			return (sts);
2607 		}
2608 
2609 		mutex_enter(&sp->shm_mlock);
2610 		/* enforce locked memory rctl */
2611 		unlocked = spt_unlockedbytes(npages, &ppa[ppa_idx]);
2612 
2613 		mutex_enter(&p->p_lock);
2614 		if (rctl_incr_locked_mem(p, proj, unlocked, 0)) {
2615 			mutex_exit(&p->p_lock);
2616 			sts = EAGAIN;
2617 		} else {
2618 			mutex_exit(&p->p_lock);
2619 			sts = spt_lockpages(seg, an_idx, npages,
2620 			    &ppa[ppa_idx], lockmap, pos, &locked);
2621 
2622 			/*
2623 			 * correct locked count if not all pages could be
2624 			 * locked
2625 			 */
2626 			if ((unlocked - locked) > 0) {
2627 				rctl_decr_locked_mem(NULL, proj,
2628 				    (unlocked - locked), 0);
2629 			}
2630 		}
2631 		/*
2632 		 * unlock pages
2633 		 */
2634 		for (i = 0; i < a_npages; i++)
2635 			page_unlock(ppa[i]);
2636 		if (sptd->spt_ppa != NULL)
2637 			sptd->spt_flags |= DISM_PPA_CHANGED;
2638 		mutex_exit(&sp->shm_mlock);
2639 		mutex_exit(&sptd->spt_lock);
2640 
2641 		kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2642 
2643 	} else if (op == MC_UNLOCK) { /* unlock */
2644 		struct anon_map *amp;
2645 		struct anon 	*ap;
2646 		struct vnode 	*vp;
2647 		u_offset_t 	off;
2648 		struct page	*pp;
2649 		int		kernel;
2650 		anon_sync_obj_t cookie;
2651 		rctl_qty_t	unlocked = 0;
2652 		page_t		**ppa;
2653 
2654 		amp = sptd->spt_amp;
2655 		mutex_enter(&sptd->spt_lock);
2656 		if (shmd->shm_lckpgs == 0) {
2657 			mutex_exit(&sptd->spt_lock);
2658 			return (0);
2659 		}
2660 		/*
2661 		 * Don't cache new IO pages.
2662 		 */
2663 		if (sptd->spt_ppa != NULL)
2664 			sptd->spt_flags |= DISM_PPA_CHANGED;
2665 
2666 		mutex_enter(&sp->shm_mlock);
2667 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2668 		for (i = 0; i < npages; i++, an_idx++) {
2669 			if (shmd->shm_vpage[an_idx] & DISM_PG_LOCKED) {
2670 				anon_array_enter(amp, an_idx, &cookie);
2671 				ap = anon_get_ptr(amp->ahp, an_idx);
2672 				ASSERT(ap);
2673 
2674 				swap_xlate(ap, &vp, &off);
2675 				anon_array_exit(&cookie);
2676 				pp = page_lookup(vp, off, SE_SHARED);
2677 				ASSERT(pp);
2678 				/*
2679 				 * the availrmem is decremented only for
2680 				 * pages which are not in seg pcache,
2681 				 * for pages in seg pcache availrmem was
2682 				 * decremented in _dismpagelock() (if
2683 				 * they were not locked here)
2684 				 */
2685 				kernel = (sptd->spt_ppa &&
2686 				    sptd->spt_ppa[an_idx]) ? 1 : 0;
2687 				ASSERT(pp->p_lckcnt > 0);
2688 				page_pp_unlock(pp, 0, kernel);
2689 				if (pp->p_lckcnt == 0)
2690 					unlocked += PAGESIZE;
2691 				page_unlock(pp);
2692 				shmd->shm_vpage[an_idx] &= ~DISM_PG_LOCKED;
2693 				sptd->spt_ppa_lckcnt[an_idx]--;
2694 				shmd->shm_lckpgs--;
2695 			}
2696 		}
2697 		ANON_LOCK_EXIT(&amp->a_rwlock);
2698 		if ((ppa = sptd->spt_ppa) != NULL)
2699 			sptd->spt_flags |= DISM_PPA_CHANGED;
2700 		mutex_exit(&sptd->spt_lock);
2701 
2702 		rctl_decr_locked_mem(NULL, proj, unlocked, 0);
2703 		mutex_exit(&sp->shm_mlock);
2704 
2705 		if (ppa != NULL)
2706 			seg_ppurge_wiredpp(ppa);
2707 	}
2708 	return (sts);
2709 }
2710 
2711 /*ARGSUSED*/
2712 int
2713 segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
2714 {
2715 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2716 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2717 	spgcnt_t pgno = seg_page(seg, addr+len) - seg_page(seg, addr) + 1;
2718 
2719 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2720 
2721 	/*
2722 	 * ISM segment is always rw.
2723 	 */
2724 	while (--pgno >= 0)
2725 		*protv++ = sptd->spt_prot;
2726 	return (0);
2727 }
2728 
2729 /*ARGSUSED*/
2730 u_offset_t
2731 segspt_shmgetoffset(struct seg *seg, caddr_t addr)
2732 {
2733 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2734 
2735 	/* Offset does not matter in ISM memory */
2736 
2737 	return ((u_offset_t)0);
2738 }
2739 
2740 /* ARGSUSED */
2741 int
2742 segspt_shmgettype(struct seg *seg, caddr_t addr)
2743 {
2744 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2745 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2746 
2747 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2748 
2749 	/*
2750 	 * The shared memory mapping is always MAP_SHARED, SWAP is only
2751 	 * reserved for DISM
2752 	 */
2753 	return (MAP_SHARED |
2754 	    ((sptd->spt_flags & SHM_PAGEABLE) ? 0 : MAP_NORESERVE));
2755 }
2756 
2757 /*ARGSUSED*/
2758 int
2759 segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
2760 {
2761 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2762 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2763 
2764 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2765 
2766 	*vpp = sptd->spt_vp;
2767 	return (0);
2768 }
2769 
2770 /*
2771  * We need to wait for pending IO to complete to a DISM segment in order for
2772  * pages to get kicked out of the seg_pcache.  120 seconds should be more
2773  * than enough time to wait.
2774  */
2775 static clock_t spt_pcache_wait = 120;
2776 
2777 /*ARGSUSED*/
2778 static int
2779 segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
2780 {
2781 	struct shm_data	*shmd = (struct shm_data *)seg->s_data;
2782 	struct spt_data	*sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2783 	struct anon_map	*amp;
2784 	pgcnt_t pg_idx;
2785 	ushort_t gen;
2786 	clock_t	end_lbolt;
2787 	int writer;
2788 	page_t **ppa;
2789 
2790 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2791 
2792 	if (behav == MADV_FREE) {
2793 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0)
2794 			return (0);
2795 
2796 		amp = sptd->spt_amp;
2797 		pg_idx = seg_page(seg, addr);
2798 
2799 		mutex_enter(&sptd->spt_lock);
2800 		if ((ppa = sptd->spt_ppa) == NULL) {
2801 			mutex_exit(&sptd->spt_lock);
2802 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2803 			anon_disclaim(amp, pg_idx, len);
2804 			ANON_LOCK_EXIT(&amp->a_rwlock);
2805 			return (0);
2806 		}
2807 
2808 		sptd->spt_flags |= DISM_PPA_CHANGED;
2809 		gen = sptd->spt_gen;
2810 
2811 		mutex_exit(&sptd->spt_lock);
2812 
2813 		/*
2814 		 * Purge all DISM cached pages
2815 		 */
2816 		seg_ppurge_wiredpp(ppa);
2817 
2818 		/*
2819 		 * Drop the AS_LOCK so that other threads can grab it
2820 		 * in the as_pageunlock path and hopefully get the segment
2821 		 * kicked out of the seg_pcache.  We bump the shm_softlockcnt
2822 		 * to keep this segment resident.
2823 		 */
2824 		writer = AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock);
2825 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), 1);
2826 		AS_LOCK_EXIT(seg->s_as, &seg->s_as->a_lock);
2827 
2828 		mutex_enter(&sptd->spt_lock);
2829 
2830 		end_lbolt = lbolt + (hz * spt_pcache_wait);
2831 
2832 		/*
2833 		 * Try to wait for pages to get kicked out of the seg_pcache.
2834 		 */
2835 		while (sptd->spt_gen == gen &&
2836 		    (sptd->spt_flags & DISM_PPA_CHANGED) &&
2837 		    lbolt < end_lbolt) {
2838 			if (!cv_timedwait_sig(&sptd->spt_cv,
2839 			    &sptd->spt_lock, end_lbolt)) {
2840 				break;
2841 			}
2842 		}
2843 
2844 		mutex_exit(&sptd->spt_lock);
2845 
2846 		/* Regrab the AS_LOCK and release our hold on the segment */
2847 		AS_LOCK_ENTER(seg->s_as, &seg->s_as->a_lock,
2848 		    writer ? RW_WRITER : RW_READER);
2849 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -1);
2850 		if (shmd->shm_softlockcnt <= 0) {
2851 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2852 				mutex_enter(&seg->s_as->a_contents);
2853 				if (AS_ISUNMAPWAIT(seg->s_as)) {
2854 					AS_CLRUNMAPWAIT(seg->s_as);
2855 					cv_broadcast(&seg->s_as->a_cv);
2856 				}
2857 				mutex_exit(&seg->s_as->a_contents);
2858 			}
2859 		}
2860 
2861 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2862 		anon_disclaim(amp, pg_idx, len);
2863 		ANON_LOCK_EXIT(&amp->a_rwlock);
2864 	} else if (lgrp_optimizations() && (behav == MADV_ACCESS_LWP ||
2865 	    behav == MADV_ACCESS_MANY || behav == MADV_ACCESS_DEFAULT)) {
2866 		int			already_set;
2867 		ulong_t			anon_index;
2868 		lgrp_mem_policy_t	policy;
2869 		caddr_t			shm_addr;
2870 		size_t			share_size;
2871 		size_t			size;
2872 		struct seg		*sptseg = shmd->shm_sptseg;
2873 		caddr_t			sptseg_addr;
2874 
2875 		/*
2876 		 * Align address and length to page size of underlying segment
2877 		 */
2878 		share_size = page_get_pagesize(shmd->shm_sptseg->s_szc);
2879 		shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_size);
2880 		size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)),
2881 		    share_size);
2882 
2883 		amp = shmd->shm_amp;
2884 		anon_index = seg_page(seg, shm_addr);
2885 
2886 		/*
2887 		 * And now we may have to adjust size downward if we have
2888 		 * exceeded the realsize of the segment or initial anon
2889 		 * allocations.
2890 		 */
2891 		sptseg_addr = sptseg->s_base + ptob(anon_index);
2892 		if ((sptseg_addr + size) >
2893 		    (sptseg->s_base + sptd->spt_realsize))
2894 			size = (sptseg->s_base + sptd->spt_realsize) -
2895 			    sptseg_addr;
2896 
2897 		/*
2898 		 * Set memory allocation policy for this segment
2899 		 */
2900 		policy = lgrp_madv_to_policy(behav, len, MAP_SHARED);
2901 		already_set = lgrp_shm_policy_set(policy, amp, anon_index,
2902 		    NULL, 0, len);
2903 
2904 		/*
2905 		 * If random memory allocation policy set already,
2906 		 * don't bother reapplying it.
2907 		 */
2908 		if (already_set && !LGRP_MEM_POLICY_REAPPLICABLE(policy))
2909 			return (0);
2910 
2911 		/*
2912 		 * Mark any existing pages in the given range for
2913 		 * migration, flushing the I/O page cache, and using
2914 		 * underlying segment to calculate anon index and get
2915 		 * anonmap and vnode pointer from
2916 		 */
2917 		if (shmd->shm_softlockcnt > 0)
2918 			segspt_purge(seg);
2919 
2920 		page_mark_migrate(seg, shm_addr, size, amp, 0, NULL, 0, 0);
2921 	}
2922 
2923 	return (0);
2924 }
2925 
2926 /*ARGSUSED*/
2927 void
2928 segspt_shmdump(struct seg *seg)
2929 {
2930 	/* no-op for ISM segment */
2931 }
2932 
2933 /*ARGSUSED*/
2934 static faultcode_t
2935 segspt_shmsetpgsz(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
2936 {
2937 	return (ENOTSUP);
2938 }
2939 
2940 /*
2941  * get a memory ID for an addr in a given segment
2942  */
2943 static int
2944 segspt_shmgetmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
2945 {
2946 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2947 	struct anon 	*ap;
2948 	size_t		anon_index;
2949 	struct anon_map	*amp = shmd->shm_amp;
2950 	struct spt_data	*sptd = shmd->shm_sptseg->s_data;
2951 	struct seg	*sptseg = shmd->shm_sptseg;
2952 	anon_sync_obj_t	cookie;
2953 
2954 	anon_index = seg_page(seg, addr);
2955 
2956 	if (addr > (seg->s_base + sptd->spt_realsize)) {
2957 		return (EFAULT);
2958 	}
2959 
2960 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2961 	anon_array_enter(amp, anon_index, &cookie);
2962 	ap = anon_get_ptr(amp->ahp, anon_index);
2963 	if (ap == NULL) {
2964 		struct page *pp;
2965 		caddr_t spt_addr = sptseg->s_base + ptob(anon_index);
2966 
2967 		pp = anon_zero(sptseg, spt_addr, &ap, kcred);
2968 		if (pp == NULL) {
2969 			anon_array_exit(&cookie);
2970 			ANON_LOCK_EXIT(&amp->a_rwlock);
2971 			return (ENOMEM);
2972 		}
2973 		(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
2974 		page_unlock(pp);
2975 	}
2976 	anon_array_exit(&cookie);
2977 	ANON_LOCK_EXIT(&amp->a_rwlock);
2978 	memidp->val[0] = (uintptr_t)ap;
2979 	memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
2980 	return (0);
2981 }
2982 
2983 /*
2984  * Get memory allocation policy info for specified address in given segment
2985  */
2986 static lgrp_mem_policy_info_t *
2987 segspt_shmgetpolicy(struct seg *seg, caddr_t addr)
2988 {
2989 	struct anon_map		*amp;
2990 	ulong_t			anon_index;
2991 	lgrp_mem_policy_info_t	*policy_info;
2992 	struct shm_data		*shm_data;
2993 
2994 	ASSERT(seg != NULL);
2995 
2996 	/*
2997 	 * Get anon_map from segshm
2998 	 *
2999 	 * Assume that no lock needs to be held on anon_map, since
3000 	 * it should be protected by its reference count which must be
3001 	 * nonzero for an existing segment
3002 	 * Need to grab readers lock on policy tree though
3003 	 */
3004 	shm_data = (struct shm_data *)seg->s_data;
3005 	if (shm_data == NULL)
3006 		return (NULL);
3007 	amp = shm_data->shm_amp;
3008 	ASSERT(amp->refcnt != 0);
3009 
3010 	/*
3011 	 * Get policy info
3012 	 *
3013 	 * Assume starting anon index of 0
3014 	 */
3015 	anon_index = seg_page(seg, addr);
3016 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
3017 
3018 	return (policy_info);
3019 }
3020 
3021 /*ARGSUSED*/
3022 static int
3023 segspt_shmcapable(struct seg *seg, segcapability_t capability)
3024 {
3025 	return (0);
3026 }
3027