xref: /illumos-gate/usr/src/uts/common/vm/seg_spt.c (revision c5bab7026b8e0ac44b25ee08507ea360f177d844)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2015, Joyent, Inc. All rights reserved.
24  * Copyright (c) 2016 by Delphix. All rights reserved.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/user.h>
29 #include <sys/mman.h>
30 #include <sys/kmem.h>
31 #include <sys/sysmacros.h>
32 #include <sys/cmn_err.h>
33 #include <sys/systm.h>
34 #include <sys/tuneable.h>
35 #include <vm/hat.h>
36 #include <vm/seg.h>
37 #include <vm/as.h>
38 #include <vm/anon.h>
39 #include <vm/page.h>
40 #include <sys/buf.h>
41 #include <sys/swap.h>
42 #include <sys/atomic.h>
43 #include <vm/seg_spt.h>
44 #include <sys/debug.h>
45 #include <sys/vtrace.h>
46 #include <sys/shm.h>
47 #include <sys/shm_impl.h>
48 #include <sys/lgrp.h>
49 #include <sys/vmsystm.h>
50 #include <sys/policy.h>
51 #include <sys/project.h>
52 #include <sys/tnf_probe.h>
53 #include <sys/zone.h>
54 
55 #define	SEGSPTADDR	(caddr_t)0x0
56 
57 /*
58  * # pages used for spt
59  */
60 size_t	spt_used;
61 
62 /*
63  * segspt_minfree is the memory left for system after ISM
64  * locked its pages; it is set up to 5% of availrmem in
65  * sptcreate when ISM is created.  ISM should not use more
66  * than ~90% of availrmem; if it does, then the performance
67  * of the system may decrease. Machines with large memories may
68  * be able to use up more memory for ISM so we set the default
69  * segspt_minfree to 5% (which gives ISM max 95% of availrmem.
70  * If somebody wants even more memory for ISM (risking hanging
71  * the system) they can patch the segspt_minfree to smaller number.
72  */
73 pgcnt_t segspt_minfree = 0;
74 
75 static int segspt_create(struct seg *seg, caddr_t argsp);
76 static int segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize);
77 static void segspt_free(struct seg *seg);
78 static void segspt_free_pages(struct seg *seg, caddr_t addr, size_t len);
79 static lgrp_mem_policy_info_t *segspt_getpolicy(struct seg *seg, caddr_t addr);
80 
81 static void
82 segspt_badop()
83 {
84 	panic("segspt_badop called");
85 	/*NOTREACHED*/
86 }
87 
88 #define	SEGSPT_BADOP(t)	(t(*)())segspt_badop
89 
90 struct seg_ops segspt_ops = {
91 	SEGSPT_BADOP(int),		/* dup */
92 	segspt_unmap,
93 	segspt_free,
94 	SEGSPT_BADOP(int),		/* fault */
95 	SEGSPT_BADOP(faultcode_t),	/* faulta */
96 	SEGSPT_BADOP(int),		/* setprot */
97 	SEGSPT_BADOP(int),		/* checkprot */
98 	SEGSPT_BADOP(int),		/* kluster */
99 	SEGSPT_BADOP(size_t),		/* swapout */
100 	SEGSPT_BADOP(int),		/* sync */
101 	SEGSPT_BADOP(size_t),		/* incore */
102 	SEGSPT_BADOP(int),		/* lockop */
103 	SEGSPT_BADOP(int),		/* getprot */
104 	SEGSPT_BADOP(u_offset_t), 	/* getoffset */
105 	SEGSPT_BADOP(int),		/* gettype */
106 	SEGSPT_BADOP(int),		/* getvp */
107 	SEGSPT_BADOP(int),		/* advise */
108 	SEGSPT_BADOP(void),		/* dump */
109 	SEGSPT_BADOP(int),		/* pagelock */
110 	SEGSPT_BADOP(int),		/* setpgsz */
111 	SEGSPT_BADOP(int),		/* getmemid */
112 	segspt_getpolicy,		/* getpolicy */
113 	SEGSPT_BADOP(int),		/* capable */
114 	seg_inherit_notsup		/* inherit */
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 	seg_inherit_notsup
175 };
176 
177 static void segspt_purge(struct seg *seg);
178 static int segspt_reclaim(void *, caddr_t, size_t, struct page **,
179 		enum seg_rw, int);
180 static int spt_anon_getpages(struct seg *seg, caddr_t addr, size_t len,
181 		page_t **ppa);
182 
183 
184 
185 /*ARGSUSED*/
186 int
187 sptcreate(size_t size, struct seg **sptseg, struct anon_map *amp,
188     uint_t prot, uint_t flags, uint_t share_szc)
189 {
190 	int 	err;
191 	struct  as	*newas;
192 	struct	segspt_crargs sptcargs;
193 
194 #ifdef DEBUG
195 	TNF_PROBE_1(sptcreate, "spt", /* CSTYLED */,
196 			tnf_ulong, size, size );
197 #endif
198 	if (segspt_minfree == 0)	/* leave min 5% of availrmem for */
199 		segspt_minfree = availrmem/20;	/* for the system */
200 
201 	if (!hat_supported(HAT_SHARED_PT, (void *)0))
202 		return (EINVAL);
203 
204 	/*
205 	 * get a new as for this shared memory segment
206 	 */
207 	newas = as_alloc();
208 	newas->a_proc = NULL;
209 	sptcargs.amp = amp;
210 	sptcargs.prot = prot;
211 	sptcargs.flags = flags;
212 	sptcargs.szc = share_szc;
213 	/*
214 	 * create a shared page table (spt) segment
215 	 */
216 
217 	if (err = as_map(newas, SEGSPTADDR, size, segspt_create, &sptcargs)) {
218 		as_free(newas);
219 		return (err);
220 	}
221 	*sptseg = sptcargs.seg_spt;
222 	return (0);
223 }
224 
225 void
226 sptdestroy(struct as *as, struct anon_map *amp)
227 {
228 
229 #ifdef DEBUG
230 	TNF_PROBE_0(sptdestroy, "spt", /* CSTYLED */);
231 #endif
232 	(void) as_unmap(as, SEGSPTADDR, amp->size);
233 	as_free(as);
234 }
235 
236 /*
237  * called from seg_free().
238  * free (i.e., unlock, unmap, return to free list)
239  *  all the pages in the given seg.
240  */
241 void
242 segspt_free(struct seg	*seg)
243 {
244 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
245 
246 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
247 
248 	if (sptd != NULL) {
249 		if (sptd->spt_realsize)
250 			segspt_free_pages(seg, seg->s_base, sptd->spt_realsize);
251 
252 		if (sptd->spt_ppa_lckcnt) {
253 			kmem_free(sptd->spt_ppa_lckcnt,
254 			    sizeof (*sptd->spt_ppa_lckcnt)
255 			    * btopr(sptd->spt_amp->size));
256 		}
257 		kmem_free(sptd->spt_vp, sizeof (*sptd->spt_vp));
258 		cv_destroy(&sptd->spt_cv);
259 		mutex_destroy(&sptd->spt_lock);
260 		kmem_free(sptd, sizeof (*sptd));
261 	}
262 }
263 
264 /*ARGSUSED*/
265 static int
266 segspt_shmsync(struct seg *seg, caddr_t addr, size_t len, int attr,
267     uint_t flags)
268 {
269 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
270 
271 	return (0);
272 }
273 
274 /*ARGSUSED*/
275 static size_t
276 segspt_shmincore(struct seg *seg, caddr_t addr, size_t len, char *vec)
277 {
278 	caddr_t	eo_seg;
279 	pgcnt_t	npages;
280 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
281 	struct seg	*sptseg;
282 	struct spt_data *sptd;
283 
284 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
285 #ifdef lint
286 	seg = seg;
287 #endif
288 	sptseg = shmd->shm_sptseg;
289 	sptd = sptseg->s_data;
290 
291 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
292 		eo_seg = addr + len;
293 		while (addr < eo_seg) {
294 			/* page exists, and it's locked. */
295 			*vec++ = SEG_PAGE_INCORE | SEG_PAGE_LOCKED |
296 			    SEG_PAGE_ANON;
297 			addr += PAGESIZE;
298 		}
299 		return (len);
300 	} else {
301 		struct  anon_map *amp = shmd->shm_amp;
302 		struct  anon	*ap;
303 		page_t		*pp;
304 		pgcnt_t 	anon_index;
305 		struct vnode 	*vp;
306 		u_offset_t 	off;
307 		ulong_t		i;
308 		int		ret;
309 		anon_sync_obj_t	cookie;
310 
311 		addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
312 		anon_index = seg_page(seg, addr);
313 		npages = btopr(len);
314 		if (anon_index + npages > btopr(shmd->shm_amp->size)) {
315 			return (EINVAL);
316 		}
317 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
318 		for (i = 0; i < npages; i++, anon_index++) {
319 			ret = 0;
320 			anon_array_enter(amp, anon_index, &cookie);
321 			ap = anon_get_ptr(amp->ahp, anon_index);
322 			if (ap != NULL) {
323 				swap_xlate(ap, &vp, &off);
324 				anon_array_exit(&cookie);
325 				pp = page_lookup_nowait(vp, off, SE_SHARED);
326 				if (pp != NULL) {
327 					ret |= SEG_PAGE_INCORE | SEG_PAGE_ANON;
328 					page_unlock(pp);
329 				}
330 			} else {
331 				anon_array_exit(&cookie);
332 			}
333 			if (shmd->shm_vpage[anon_index] & DISM_PG_LOCKED) {
334 				ret |= SEG_PAGE_LOCKED;
335 			}
336 			*vec++ = (char)ret;
337 		}
338 		ANON_LOCK_EXIT(&amp->a_rwlock);
339 		return (len);
340 	}
341 }
342 
343 static int
344 segspt_unmap(struct seg *seg, caddr_t raddr, size_t ssize)
345 {
346 	size_t share_size;
347 
348 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
349 
350 	/*
351 	 * seg.s_size may have been rounded up to the largest page size
352 	 * in shmat().
353 	 * XXX This should be cleanedup. sptdestroy should take a length
354 	 * argument which should be the same as sptcreate. Then
355 	 * this rounding would not be needed (or is done in shm.c)
356 	 * Only the check for full segment will be needed.
357 	 *
358 	 * XXX -- shouldn't raddr == 0 always? These tests don't seem
359 	 * to be useful at all.
360 	 */
361 	share_size = page_get_pagesize(seg->s_szc);
362 	ssize = P2ROUNDUP(ssize, share_size);
363 
364 	if (raddr == seg->s_base && ssize == seg->s_size) {
365 		seg_free(seg);
366 		return (0);
367 	} else
368 		return (EINVAL);
369 }
370 
371 int
372 segspt_create(struct seg *seg, caddr_t argsp)
373 {
374 	int		err;
375 	caddr_t		addr = seg->s_base;
376 	struct spt_data *sptd;
377 	struct 	segspt_crargs *sptcargs = (struct segspt_crargs *)argsp;
378 	struct anon_map *amp = sptcargs->amp;
379 	struct kshmid	*sp = amp->a_sp;
380 	struct	cred	*cred = CRED();
381 	ulong_t		i, j, anon_index = 0;
382 	pgcnt_t		npages = btopr(amp->size);
383 	struct vnode	*vp;
384 	page_t		**ppa;
385 	uint_t		hat_flags;
386 	size_t		pgsz;
387 	pgcnt_t		pgcnt;
388 	caddr_t		a;
389 	pgcnt_t		pidx;
390 	size_t		sz;
391 	proc_t		*procp = curproc;
392 	rctl_qty_t	lockedbytes = 0;
393 	kproject_t	*proj;
394 
395 	/*
396 	 * We are holding the a_lock on the underlying dummy as,
397 	 * so we can make calls to the HAT layer.
398 	 */
399 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
400 	ASSERT(sp != NULL);
401 
402 #ifdef DEBUG
403 	TNF_PROBE_2(segspt_create, "spt", /* CSTYLED */,
404 	    tnf_opaque, addr, addr, tnf_ulong, len, seg->s_size);
405 #endif
406 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
407 		if (err = anon_swap_adjust(npages))
408 			return (err);
409 	}
410 	err = ENOMEM;
411 
412 	if ((sptd = kmem_zalloc(sizeof (*sptd), KM_NOSLEEP)) == NULL)
413 		goto out1;
414 
415 	if ((sptcargs->flags & SHM_PAGEABLE) == 0) {
416 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * npages),
417 		    KM_NOSLEEP)) == NULL)
418 			goto out2;
419 	}
420 
421 	mutex_init(&sptd->spt_lock, NULL, MUTEX_DEFAULT, NULL);
422 
423 	if ((vp = kmem_zalloc(sizeof (*vp), KM_NOSLEEP)) == NULL)
424 		goto out3;
425 
426 	seg->s_ops = &segspt_ops;
427 	sptd->spt_vp = vp;
428 	sptd->spt_amp = amp;
429 	sptd->spt_prot = sptcargs->prot;
430 	sptd->spt_flags = sptcargs->flags;
431 	seg->s_data = (caddr_t)sptd;
432 	sptd->spt_ppa = NULL;
433 	sptd->spt_ppa_lckcnt = NULL;
434 	seg->s_szc = sptcargs->szc;
435 	cv_init(&sptd->spt_cv, NULL, CV_DEFAULT, NULL);
436 	sptd->spt_gen = 0;
437 
438 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
439 	if (seg->s_szc > amp->a_szc) {
440 		amp->a_szc = seg->s_szc;
441 	}
442 	ANON_LOCK_EXIT(&amp->a_rwlock);
443 
444 	/*
445 	 * Set policy to affect initial allocation of pages in
446 	 * anon_map_createpages()
447 	 */
448 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, amp, anon_index,
449 	    NULL, 0, ptob(npages));
450 
451 	if (sptcargs->flags & SHM_PAGEABLE) {
452 		size_t  share_sz;
453 		pgcnt_t new_npgs, more_pgs;
454 		struct anon_hdr *nahp;
455 		zone_t *zone;
456 
457 		share_sz = page_get_pagesize(seg->s_szc);
458 		if (!IS_P2ALIGNED(amp->size, share_sz)) {
459 			/*
460 			 * We are rounding up the size of the anon array
461 			 * on 4 M boundary because we always create 4 M
462 			 * of page(s) when locking, faulting pages and we
463 			 * don't have to check for all corner cases e.g.
464 			 * if there is enough space to allocate 4 M
465 			 * page.
466 			 */
467 			new_npgs = btop(P2ROUNDUP(amp->size, share_sz));
468 			more_pgs = new_npgs - npages;
469 
470 			/*
471 			 * The zone will never be NULL, as a fully created
472 			 * shm always has an owning zone.
473 			 */
474 			zone = sp->shm_perm.ipc_zone_ref.zref_zone;
475 			ASSERT(zone != NULL);
476 			if (anon_resv_zone(ptob(more_pgs), zone) == 0) {
477 				err = ENOMEM;
478 				goto out4;
479 			}
480 
481 			nahp = anon_create(new_npgs, ANON_SLEEP);
482 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
483 			(void) anon_copy_ptr(amp->ahp, 0, nahp, 0, npages,
484 			    ANON_SLEEP);
485 			anon_release(amp->ahp, npages);
486 			amp->ahp = nahp;
487 			ASSERT(amp->swresv == ptob(npages));
488 			amp->swresv = amp->size = ptob(new_npgs);
489 			ANON_LOCK_EXIT(&amp->a_rwlock);
490 			npages = new_npgs;
491 		}
492 
493 		sptd->spt_ppa_lckcnt = kmem_zalloc(npages *
494 		    sizeof (*sptd->spt_ppa_lckcnt), KM_SLEEP);
495 		sptd->spt_pcachecnt = 0;
496 		sptd->spt_realsize = ptob(npages);
497 		sptcargs->seg_spt = seg;
498 		return (0);
499 	}
500 
501 	/*
502 	 * get array of pages for each anon slot in amp
503 	 */
504 	if ((err = anon_map_createpages(amp, anon_index, ptob(npages), ppa,
505 	    seg, addr, S_CREATE, cred)) != 0)
506 		goto out4;
507 
508 	mutex_enter(&sp->shm_mlock);
509 
510 	/* May be partially locked, so, count bytes to charge for locking */
511 	for (i = 0; i < npages; i++)
512 		if (ppa[i]->p_lckcnt == 0)
513 			lockedbytes += PAGESIZE;
514 
515 	proj = sp->shm_perm.ipc_proj;
516 
517 	if (lockedbytes > 0) {
518 		mutex_enter(&procp->p_lock);
519 		if (rctl_incr_locked_mem(procp, proj, lockedbytes, 0)) {
520 			mutex_exit(&procp->p_lock);
521 			mutex_exit(&sp->shm_mlock);
522 			for (i = 0; i < npages; i++)
523 				page_unlock(ppa[i]);
524 			err = ENOMEM;
525 			goto out4;
526 		}
527 		mutex_exit(&procp->p_lock);
528 	}
529 
530 	/*
531 	 * addr is initial address corresponding to the first page on ppa list
532 	 */
533 	for (i = 0; i < npages; i++) {
534 		/* attempt to lock all pages */
535 		if (page_pp_lock(ppa[i], 0, 1) == 0) {
536 			/*
537 			 * if unable to lock any page, unlock all
538 			 * of them and return error
539 			 */
540 			for (j = 0; j < i; j++)
541 				page_pp_unlock(ppa[j], 0, 1);
542 			for (i = 0; i < npages; i++)
543 				page_unlock(ppa[i]);
544 			rctl_decr_locked_mem(NULL, proj, lockedbytes, 0);
545 			mutex_exit(&sp->shm_mlock);
546 			err = ENOMEM;
547 			goto out4;
548 		}
549 	}
550 	mutex_exit(&sp->shm_mlock);
551 
552 	/*
553 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
554 	 * for the entire life of the segment. For example platforms
555 	 * that do not support Dynamic Reconfiguration.
556 	 */
557 	hat_flags = HAT_LOAD_SHARE;
558 	if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, NULL))
559 		hat_flags |= HAT_LOAD_LOCK;
560 
561 	/*
562 	 * Load translations one lare page at a time
563 	 * to make sure we don't create mappings bigger than
564 	 * segment's size code in case underlying pages
565 	 * are shared with segvn's segment that uses bigger
566 	 * size code than we do.
567 	 */
568 	pgsz = page_get_pagesize(seg->s_szc);
569 	pgcnt = page_get_pagecnt(seg->s_szc);
570 	for (a = addr, pidx = 0; pidx < npages; a += pgsz, pidx += pgcnt) {
571 		sz = MIN(pgsz, ptob(npages - pidx));
572 		hat_memload_array(seg->s_as->a_hat, a, sz,
573 		    &ppa[pidx], sptd->spt_prot, hat_flags);
574 	}
575 
576 	/*
577 	 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
578 	 * we will leave the pages locked SE_SHARED for the life
579 	 * of the ISM segment. This will prevent any calls to
580 	 * hat_pageunload() on this ISM segment for those platforms.
581 	 */
582 	if (!(hat_flags & HAT_LOAD_LOCK)) {
583 		/*
584 		 * On platforms that support HAT_DYNAMIC_ISM_UNMAP,
585 		 * we no longer need to hold the SE_SHARED lock on the pages,
586 		 * since L_PAGELOCK and F_SOFTLOCK calls will grab the
587 		 * SE_SHARED lock on the pages as necessary.
588 		 */
589 		for (i = 0; i < npages; i++)
590 			page_unlock(ppa[i]);
591 	}
592 	sptd->spt_pcachecnt = 0;
593 	kmem_free(ppa, ((sizeof (page_t *)) * npages));
594 	sptd->spt_realsize = ptob(npages);
595 	atomic_add_long(&spt_used, npages);
596 	sptcargs->seg_spt = seg;
597 	return (0);
598 
599 out4:
600 	seg->s_data = NULL;
601 	kmem_free(vp, sizeof (*vp));
602 	cv_destroy(&sptd->spt_cv);
603 out3:
604 	mutex_destroy(&sptd->spt_lock);
605 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
606 		kmem_free(ppa, (sizeof (*ppa) * npages));
607 out2:
608 	kmem_free(sptd, sizeof (*sptd));
609 out1:
610 	if ((sptcargs->flags & SHM_PAGEABLE) == 0)
611 		anon_swap_restore(npages);
612 	return (err);
613 }
614 
615 /*ARGSUSED*/
616 void
617 segspt_free_pages(struct seg *seg, caddr_t addr, size_t len)
618 {
619 	struct page 	*pp;
620 	struct spt_data *sptd = (struct spt_data *)seg->s_data;
621 	pgcnt_t		npages;
622 	ulong_t		anon_idx;
623 	struct anon_map *amp;
624 	struct anon 	*ap;
625 	struct vnode 	*vp;
626 	u_offset_t 	off;
627 	uint_t		hat_flags;
628 	int		root = 0;
629 	pgcnt_t		pgs, curnpgs = 0;
630 	page_t		*rootpp;
631 	rctl_qty_t	unlocked_bytes = 0;
632 	kproject_t	*proj;
633 	kshmid_t	*sp;
634 
635 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
636 
637 	len = P2ROUNDUP(len, PAGESIZE);
638 
639 	npages = btop(len);
640 
641 	hat_flags = HAT_UNLOAD_UNLOCK | HAT_UNLOAD_UNMAP;
642 	if ((hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) ||
643 	    (sptd->spt_flags & SHM_PAGEABLE)) {
644 		hat_flags = HAT_UNLOAD_UNMAP;
645 	}
646 
647 	hat_unload(seg->s_as->a_hat, addr, len, hat_flags);
648 
649 	amp = sptd->spt_amp;
650 	if (sptd->spt_flags & SHM_PAGEABLE)
651 		npages = btop(amp->size);
652 
653 	ASSERT(amp != NULL);
654 
655 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
656 		sp = amp->a_sp;
657 		proj = sp->shm_perm.ipc_proj;
658 		mutex_enter(&sp->shm_mlock);
659 	}
660 	for (anon_idx = 0; anon_idx < npages; anon_idx++) {
661 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
662 			if ((ap = anon_get_ptr(amp->ahp, anon_idx)) == NULL) {
663 				panic("segspt_free_pages: null app");
664 				/*NOTREACHED*/
665 			}
666 		} else {
667 			if ((ap = anon_get_next_ptr(amp->ahp, &anon_idx))
668 			    == NULL)
669 				continue;
670 		}
671 		ASSERT(ANON_ISBUSY(anon_get_slot(amp->ahp, anon_idx)) == 0);
672 		swap_xlate(ap, &vp, &off);
673 
674 		/*
675 		 * If this platform supports HAT_DYNAMIC_ISM_UNMAP,
676 		 * the pages won't be having SE_SHARED lock at this
677 		 * point.
678 		 *
679 		 * On platforms that do not support HAT_DYNAMIC_ISM_UNMAP,
680 		 * the pages are still held SE_SHARED locked from the
681 		 * original segspt_create()
682 		 *
683 		 * Our goal is to get SE_EXCL lock on each page, remove
684 		 * permanent lock on it and invalidate the page.
685 		 */
686 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
687 			if (hat_flags == HAT_UNLOAD_UNMAP)
688 				pp = page_lookup(vp, off, SE_EXCL);
689 			else {
690 				if ((pp = page_find(vp, off)) == NULL) {
691 					panic("segspt_free_pages: "
692 					    "page not locked");
693 					/*NOTREACHED*/
694 				}
695 				if (!page_tryupgrade(pp)) {
696 					page_unlock(pp);
697 					pp = page_lookup(vp, off, SE_EXCL);
698 				}
699 			}
700 			if (pp == NULL) {
701 				panic("segspt_free_pages: "
702 				    "page not in the system");
703 				/*NOTREACHED*/
704 			}
705 			ASSERT(pp->p_lckcnt > 0);
706 			page_pp_unlock(pp, 0, 1);
707 			if (pp->p_lckcnt == 0)
708 				unlocked_bytes += PAGESIZE;
709 		} else {
710 			if ((pp = page_lookup(vp, off, SE_EXCL)) == NULL)
711 				continue;
712 		}
713 		/*
714 		 * It's logical to invalidate the pages here as in most cases
715 		 * these were created by segspt.
716 		 */
717 		if (pp->p_szc != 0) {
718 			if (root == 0) {
719 				ASSERT(curnpgs == 0);
720 				root = 1;
721 				rootpp = pp;
722 				pgs = curnpgs = page_get_pagecnt(pp->p_szc);
723 				ASSERT(pgs > 1);
724 				ASSERT(IS_P2ALIGNED(pgs, pgs));
725 				ASSERT(!(page_pptonum(pp) & (pgs - 1)));
726 				curnpgs--;
727 			} else if ((page_pptonum(pp) & (pgs - 1)) == pgs - 1) {
728 				ASSERT(curnpgs == 1);
729 				ASSERT(page_pptonum(pp) ==
730 				    page_pptonum(rootpp) + (pgs - 1));
731 				page_destroy_pages(rootpp);
732 				root = 0;
733 				curnpgs = 0;
734 			} else {
735 				ASSERT(curnpgs > 1);
736 				ASSERT(page_pptonum(pp) ==
737 				    page_pptonum(rootpp) + (pgs - curnpgs));
738 				curnpgs--;
739 			}
740 		} else {
741 			if (root != 0 || curnpgs != 0) {
742 				panic("segspt_free_pages: bad large page");
743 				/*NOTREACHED*/
744 			}
745 			/*
746 			 * Before destroying the pages, we need to take care
747 			 * of the rctl locked memory accounting. For that
748 			 * we need to calculte the unlocked_bytes.
749 			 */
750 			if (pp->p_lckcnt > 0)
751 				unlocked_bytes += PAGESIZE;
752 			/*LINTED: constant in conditional context */
753 			VN_DISPOSE(pp, B_INVAL, 0, kcred);
754 		}
755 	}
756 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
757 		if (unlocked_bytes > 0)
758 			rctl_decr_locked_mem(NULL, proj, unlocked_bytes, 0);
759 		mutex_exit(&sp->shm_mlock);
760 	}
761 	if (root != 0 || curnpgs != 0) {
762 		panic("segspt_free_pages: bad large page");
763 		/*NOTREACHED*/
764 	}
765 
766 	/*
767 	 * mark that pages have been released
768 	 */
769 	sptd->spt_realsize = 0;
770 
771 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
772 		atomic_add_long(&spt_used, -npages);
773 		anon_swap_restore(npages);
774 	}
775 }
776 
777 /*
778  * Get memory allocation policy info for specified address in given segment
779  */
780 static lgrp_mem_policy_info_t *
781 segspt_getpolicy(struct seg *seg, caddr_t addr)
782 {
783 	struct anon_map		*amp;
784 	ulong_t			anon_index;
785 	lgrp_mem_policy_info_t	*policy_info;
786 	struct spt_data		*spt_data;
787 
788 	ASSERT(seg != NULL);
789 
790 	/*
791 	 * Get anon_map from segspt
792 	 *
793 	 * Assume that no lock needs to be held on anon_map, since
794 	 * it should be protected by its reference count which must be
795 	 * nonzero for an existing segment
796 	 * Need to grab readers lock on policy tree though
797 	 */
798 	spt_data = (struct spt_data *)seg->s_data;
799 	if (spt_data == NULL)
800 		return (NULL);
801 	amp = spt_data->spt_amp;
802 	ASSERT(amp->refcnt != 0);
803 
804 	/*
805 	 * Get policy info
806 	 *
807 	 * Assume starting anon index of 0
808 	 */
809 	anon_index = seg_page(seg, addr);
810 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
811 
812 	return (policy_info);
813 }
814 
815 /*
816  * DISM only.
817  * Return locked pages over a given range.
818  *
819  * We will cache all DISM locked pages and save the pplist for the
820  * entire segment in the ppa field of the underlying DISM segment structure.
821  * Later, during a call to segspt_reclaim() we will use this ppa array
822  * to page_unlock() all of the pages and then we will free this ppa list.
823  */
824 /*ARGSUSED*/
825 static int
826 segspt_dismpagelock(struct seg *seg, caddr_t addr, size_t len,
827     struct page ***ppp, enum lock_type type, enum seg_rw rw)
828 {
829 	struct  shm_data *shmd = (struct shm_data *)seg->s_data;
830 	struct  seg	*sptseg = shmd->shm_sptseg;
831 	struct  spt_data *sptd = sptseg->s_data;
832 	pgcnt_t pg_idx, npages, tot_npages, npgs;
833 	struct  page **pplist, **pl, **ppa, *pp;
834 	struct  anon_map *amp;
835 	spgcnt_t	an_idx;
836 	int 	ret = ENOTSUP;
837 	uint_t	pl_built = 0;
838 	struct  anon *ap;
839 	struct  vnode *vp;
840 	u_offset_t off;
841 	pgcnt_t claim_availrmem = 0;
842 	uint_t	szc;
843 
844 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
845 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
846 
847 	/*
848 	 * We want to lock/unlock the entire ISM segment. Therefore,
849 	 * we will be using the underlying sptseg and it's base address
850 	 * and length for the caching arguments.
851 	 */
852 	ASSERT(sptseg);
853 	ASSERT(sptd);
854 
855 	pg_idx = seg_page(seg, addr);
856 	npages = btopr(len);
857 
858 	/*
859 	 * check if the request is larger than number of pages covered
860 	 * by amp
861 	 */
862 	if (pg_idx + npages > btopr(sptd->spt_amp->size)) {
863 		*ppp = NULL;
864 		return (ENOTSUP);
865 	}
866 
867 	if (type == L_PAGEUNLOCK) {
868 		ASSERT(sptd->spt_ppa != NULL);
869 
870 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
871 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
872 
873 		/*
874 		 * If someone is blocked while unmapping, we purge
875 		 * segment page cache and thus reclaim pplist synchronously
876 		 * without waiting for seg_pasync_thread. This speeds up
877 		 * unmapping in cases where munmap(2) is called, while
878 		 * raw async i/o is still in progress or where a thread
879 		 * exits on data fault in a multithreaded application.
880 		 */
881 		if ((sptd->spt_flags & DISM_PPA_CHANGED) ||
882 		    (AS_ISUNMAPWAIT(seg->s_as) &&
883 		    shmd->shm_softlockcnt > 0)) {
884 			segspt_purge(seg);
885 		}
886 		return (0);
887 	}
888 
889 	/* The L_PAGELOCK case ... */
890 
891 	if (sptd->spt_flags & DISM_PPA_CHANGED) {
892 		segspt_purge(seg);
893 		/*
894 		 * for DISM ppa needs to be rebuild since
895 		 * number of locked pages could be changed
896 		 */
897 		*ppp = NULL;
898 		return (ENOTSUP);
899 	}
900 
901 	/*
902 	 * First try to find pages in segment page cache, without
903 	 * holding the segment lock.
904 	 */
905 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
906 	    S_WRITE, SEGP_FORCE_WIRED);
907 	if (pplist != NULL) {
908 		ASSERT(sptd->spt_ppa != NULL);
909 		ASSERT(sptd->spt_ppa == pplist);
910 		ppa = sptd->spt_ppa;
911 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
912 			if (ppa[an_idx] == NULL) {
913 				seg_pinactive(seg, NULL, seg->s_base,
914 				    sptd->spt_amp->size, ppa,
915 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
916 				*ppp = NULL;
917 				return (ENOTSUP);
918 			}
919 			if ((szc = ppa[an_idx]->p_szc) != 0) {
920 				npgs = page_get_pagecnt(szc);
921 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
922 			} else {
923 				an_idx++;
924 			}
925 		}
926 		/*
927 		 * Since we cache the entire DISM segment, we want to
928 		 * set ppp to point to the first slot that corresponds
929 		 * to the requested addr, i.e. pg_idx.
930 		 */
931 		*ppp = &(sptd->spt_ppa[pg_idx]);
932 		return (0);
933 	}
934 
935 	mutex_enter(&sptd->spt_lock);
936 	/*
937 	 * try to find pages in segment page cache with mutex
938 	 */
939 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
940 	    S_WRITE, SEGP_FORCE_WIRED);
941 	if (pplist != NULL) {
942 		ASSERT(sptd->spt_ppa != NULL);
943 		ASSERT(sptd->spt_ppa == pplist);
944 		ppa = sptd->spt_ppa;
945 		for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
946 			if (ppa[an_idx] == NULL) {
947 				mutex_exit(&sptd->spt_lock);
948 				seg_pinactive(seg, NULL, seg->s_base,
949 				    sptd->spt_amp->size, ppa,
950 				    S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
951 				*ppp = NULL;
952 				return (ENOTSUP);
953 			}
954 			if ((szc = ppa[an_idx]->p_szc) != 0) {
955 				npgs = page_get_pagecnt(szc);
956 				an_idx = P2ROUNDUP(an_idx + 1, npgs);
957 			} else {
958 				an_idx++;
959 			}
960 		}
961 		/*
962 		 * Since we cache the entire DISM segment, we want to
963 		 * set ppp to point to the first slot that corresponds
964 		 * to the requested addr, i.e. pg_idx.
965 		 */
966 		mutex_exit(&sptd->spt_lock);
967 		*ppp = &(sptd->spt_ppa[pg_idx]);
968 		return (0);
969 	}
970 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
971 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
972 		mutex_exit(&sptd->spt_lock);
973 		*ppp = NULL;
974 		return (ENOTSUP);
975 	}
976 
977 	/*
978 	 * No need to worry about protections because DISM pages are always rw.
979 	 */
980 	pl = pplist = NULL;
981 	amp = sptd->spt_amp;
982 
983 	/*
984 	 * Do we need to build the ppa array?
985 	 */
986 	if (sptd->spt_ppa == NULL) {
987 		pgcnt_t lpg_cnt = 0;
988 
989 		pl_built = 1;
990 		tot_npages = btopr(sptd->spt_amp->size);
991 
992 		ASSERT(sptd->spt_pcachecnt == 0);
993 		pplist = kmem_zalloc(sizeof (page_t *) * tot_npages, KM_SLEEP);
994 		pl = pplist;
995 
996 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
997 		for (an_idx = 0; an_idx < tot_npages; ) {
998 			ap = anon_get_ptr(amp->ahp, an_idx);
999 			/*
1000 			 * Cache only mlocked pages. For large pages
1001 			 * if one (constituent) page is mlocked
1002 			 * all pages for that large page
1003 			 * are cached also. This is for quick
1004 			 * lookups of ppa array;
1005 			 */
1006 			if ((ap != NULL) && (lpg_cnt != 0 ||
1007 			    (sptd->spt_ppa_lckcnt[an_idx] != 0))) {
1008 
1009 				swap_xlate(ap, &vp, &off);
1010 				pp = page_lookup(vp, off, SE_SHARED);
1011 				ASSERT(pp != NULL);
1012 				if (lpg_cnt == 0) {
1013 					lpg_cnt++;
1014 					/*
1015 					 * For a small page, we are done --
1016 					 * lpg_count is reset to 0 below.
1017 					 *
1018 					 * For a large page, we are guaranteed
1019 					 * to find the anon structures of all
1020 					 * constituent pages and a non-zero
1021 					 * lpg_cnt ensures that we don't test
1022 					 * for mlock for these. We are done
1023 					 * when lpg_count reaches (npgs + 1).
1024 					 * If we are not the first constituent
1025 					 * page, restart at the first one.
1026 					 */
1027 					npgs = page_get_pagecnt(pp->p_szc);
1028 					if (!IS_P2ALIGNED(an_idx, npgs)) {
1029 						an_idx = P2ALIGN(an_idx, npgs);
1030 						page_unlock(pp);
1031 						continue;
1032 					}
1033 				}
1034 				if (++lpg_cnt > npgs)
1035 					lpg_cnt = 0;
1036 
1037 				/*
1038 				 * availrmem is decremented only
1039 				 * for unlocked pages
1040 				 */
1041 				if (sptd->spt_ppa_lckcnt[an_idx] == 0)
1042 					claim_availrmem++;
1043 				pplist[an_idx] = pp;
1044 			}
1045 			an_idx++;
1046 		}
1047 		ANON_LOCK_EXIT(&amp->a_rwlock);
1048 
1049 		if (claim_availrmem) {
1050 			mutex_enter(&freemem_lock);
1051 			if (availrmem < tune.t_minarmem + claim_availrmem) {
1052 				mutex_exit(&freemem_lock);
1053 				ret = ENOTSUP;
1054 				claim_availrmem = 0;
1055 				goto insert_fail;
1056 			} else {
1057 				availrmem -= claim_availrmem;
1058 			}
1059 			mutex_exit(&freemem_lock);
1060 		}
1061 
1062 		sptd->spt_ppa = pl;
1063 	} else {
1064 		/*
1065 		 * We already have a valid ppa[].
1066 		 */
1067 		pl = sptd->spt_ppa;
1068 	}
1069 
1070 	ASSERT(pl != NULL);
1071 
1072 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1073 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1074 	    segspt_reclaim);
1075 	if (ret == SEGP_FAIL) {
1076 		/*
1077 		 * seg_pinsert failed. We return
1078 		 * ENOTSUP, so that the as_pagelock() code will
1079 		 * then try the slower F_SOFTLOCK path.
1080 		 */
1081 		if (pl_built) {
1082 			/*
1083 			 * No one else has referenced the ppa[].
1084 			 * We created it and we need to destroy it.
1085 			 */
1086 			sptd->spt_ppa = NULL;
1087 		}
1088 		ret = ENOTSUP;
1089 		goto insert_fail;
1090 	}
1091 
1092 	/*
1093 	 * In either case, we increment softlockcnt on the 'real' segment.
1094 	 */
1095 	sptd->spt_pcachecnt++;
1096 	atomic_inc_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
1097 
1098 	ppa = sptd->spt_ppa;
1099 	for (an_idx = pg_idx; an_idx < pg_idx + npages; ) {
1100 		if (ppa[an_idx] == NULL) {
1101 			mutex_exit(&sptd->spt_lock);
1102 			seg_pinactive(seg, NULL, seg->s_base,
1103 			    sptd->spt_amp->size,
1104 			    pl, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1105 			*ppp = NULL;
1106 			return (ENOTSUP);
1107 		}
1108 		if ((szc = ppa[an_idx]->p_szc) != 0) {
1109 			npgs = page_get_pagecnt(szc);
1110 			an_idx = P2ROUNDUP(an_idx + 1, npgs);
1111 		} else {
1112 			an_idx++;
1113 		}
1114 	}
1115 	/*
1116 	 * We can now drop the sptd->spt_lock since the ppa[]
1117 	 * exists and we have incremented pacachecnt.
1118 	 */
1119 	mutex_exit(&sptd->spt_lock);
1120 
1121 	/*
1122 	 * Since we cache the entire segment, we want to
1123 	 * set ppp to point to the first slot that corresponds
1124 	 * to the requested addr, i.e. pg_idx.
1125 	 */
1126 	*ppp = &(sptd->spt_ppa[pg_idx]);
1127 	return (0);
1128 
1129 insert_fail:
1130 	/*
1131 	 * We will only reach this code if we tried and failed.
1132 	 *
1133 	 * And we can drop the lock on the dummy seg, once we've failed
1134 	 * to set up a new ppa[].
1135 	 */
1136 	mutex_exit(&sptd->spt_lock);
1137 
1138 	if (pl_built) {
1139 		if (claim_availrmem) {
1140 			mutex_enter(&freemem_lock);
1141 			availrmem += claim_availrmem;
1142 			mutex_exit(&freemem_lock);
1143 		}
1144 
1145 		/*
1146 		 * We created pl and we need to destroy it.
1147 		 */
1148 		pplist = pl;
1149 		for (an_idx = 0; an_idx < tot_npages; an_idx++) {
1150 			if (pplist[an_idx] != NULL)
1151 				page_unlock(pplist[an_idx]);
1152 		}
1153 		kmem_free(pl, sizeof (page_t *) * tot_npages);
1154 	}
1155 
1156 	if (shmd->shm_softlockcnt <= 0) {
1157 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1158 			mutex_enter(&seg->s_as->a_contents);
1159 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1160 				AS_CLRUNMAPWAIT(seg->s_as);
1161 				cv_broadcast(&seg->s_as->a_cv);
1162 			}
1163 			mutex_exit(&seg->s_as->a_contents);
1164 		}
1165 	}
1166 	*ppp = NULL;
1167 	return (ret);
1168 }
1169 
1170 
1171 
1172 /*
1173  * return locked pages over a given range.
1174  *
1175  * We will cache the entire ISM segment and save the pplist for the
1176  * entire segment in the ppa field of the underlying ISM segment structure.
1177  * Later, during a call to segspt_reclaim() we will use this ppa array
1178  * to page_unlock() all of the pages and then we will free this ppa list.
1179  */
1180 /*ARGSUSED*/
1181 static int
1182 segspt_shmpagelock(struct seg *seg, caddr_t addr, size_t len,
1183     struct page ***ppp, enum lock_type type, enum seg_rw rw)
1184 {
1185 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1186 	struct seg	*sptseg = shmd->shm_sptseg;
1187 	struct spt_data *sptd = sptseg->s_data;
1188 	pgcnt_t np, page_index, npages;
1189 	caddr_t a, spt_base;
1190 	struct page **pplist, **pl, *pp;
1191 	struct anon_map *amp;
1192 	ulong_t anon_index;
1193 	int ret = ENOTSUP;
1194 	uint_t	pl_built = 0;
1195 	struct anon *ap;
1196 	struct vnode *vp;
1197 	u_offset_t off;
1198 
1199 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1200 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
1201 
1202 
1203 	/*
1204 	 * We want to lock/unlock the entire ISM segment. Therefore,
1205 	 * we will be using the underlying sptseg and it's base address
1206 	 * and length for the caching arguments.
1207 	 */
1208 	ASSERT(sptseg);
1209 	ASSERT(sptd);
1210 
1211 	if (sptd->spt_flags & SHM_PAGEABLE) {
1212 		return (segspt_dismpagelock(seg, addr, len, ppp, type, rw));
1213 	}
1214 
1215 	page_index = seg_page(seg, addr);
1216 	npages = btopr(len);
1217 
1218 	/*
1219 	 * check if the request is larger than number of pages covered
1220 	 * by amp
1221 	 */
1222 	if (page_index + npages > btopr(sptd->spt_amp->size)) {
1223 		*ppp = NULL;
1224 		return (ENOTSUP);
1225 	}
1226 
1227 	if (type == L_PAGEUNLOCK) {
1228 
1229 		ASSERT(sptd->spt_ppa != NULL);
1230 
1231 		seg_pinactive(seg, NULL, seg->s_base, sptd->spt_amp->size,
1232 		    sptd->spt_ppa, S_WRITE, SEGP_FORCE_WIRED, segspt_reclaim);
1233 
1234 		/*
1235 		 * If someone is blocked while unmapping, we purge
1236 		 * segment page cache and thus reclaim pplist synchronously
1237 		 * without waiting for seg_pasync_thread. This speeds up
1238 		 * unmapping in cases where munmap(2) is called, while
1239 		 * raw async i/o is still in progress or where a thread
1240 		 * exits on data fault in a multithreaded application.
1241 		 */
1242 		if (AS_ISUNMAPWAIT(seg->s_as) && (shmd->shm_softlockcnt > 0)) {
1243 			segspt_purge(seg);
1244 		}
1245 		return (0);
1246 	}
1247 
1248 	/* The L_PAGELOCK case... */
1249 
1250 	/*
1251 	 * First try to find pages in segment page cache, without
1252 	 * holding the segment lock.
1253 	 */
1254 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1255 	    S_WRITE, SEGP_FORCE_WIRED);
1256 	if (pplist != NULL) {
1257 		ASSERT(sptd->spt_ppa == pplist);
1258 		ASSERT(sptd->spt_ppa[page_index]);
1259 		/*
1260 		 * Since we cache the entire ISM segment, we want to
1261 		 * set ppp to point to the first slot that corresponds
1262 		 * to the requested addr, i.e. page_index.
1263 		 */
1264 		*ppp = &(sptd->spt_ppa[page_index]);
1265 		return (0);
1266 	}
1267 
1268 	mutex_enter(&sptd->spt_lock);
1269 
1270 	/*
1271 	 * try to find pages in segment page cache
1272 	 */
1273 	pplist = seg_plookup(seg, NULL, seg->s_base, sptd->spt_amp->size,
1274 	    S_WRITE, SEGP_FORCE_WIRED);
1275 	if (pplist != NULL) {
1276 		ASSERT(sptd->spt_ppa == pplist);
1277 		/*
1278 		 * Since we cache the entire segment, we want to
1279 		 * set ppp to point to the first slot that corresponds
1280 		 * to the requested addr, i.e. page_index.
1281 		 */
1282 		mutex_exit(&sptd->spt_lock);
1283 		*ppp = &(sptd->spt_ppa[page_index]);
1284 		return (0);
1285 	}
1286 
1287 	if (seg_pinsert_check(seg, NULL, seg->s_base, sptd->spt_amp->size,
1288 	    SEGP_FORCE_WIRED) == SEGP_FAIL) {
1289 		mutex_exit(&sptd->spt_lock);
1290 		*ppp = NULL;
1291 		return (ENOTSUP);
1292 	}
1293 
1294 	/*
1295 	 * No need to worry about protections because ISM pages
1296 	 * are always rw.
1297 	 */
1298 	pl = pplist = NULL;
1299 
1300 	/*
1301 	 * Do we need to build the ppa array?
1302 	 */
1303 	if (sptd->spt_ppa == NULL) {
1304 		ASSERT(sptd->spt_ppa == pplist);
1305 
1306 		spt_base = sptseg->s_base;
1307 		pl_built = 1;
1308 
1309 		/*
1310 		 * availrmem is decremented once during anon_swap_adjust()
1311 		 * and is incremented during the anon_unresv(), which is
1312 		 * called from shm_rm_amp() when the segment is destroyed.
1313 		 */
1314 		amp = sptd->spt_amp;
1315 		ASSERT(amp != NULL);
1316 
1317 		/* pcachecnt is protected by sptd->spt_lock */
1318 		ASSERT(sptd->spt_pcachecnt == 0);
1319 		pplist = kmem_zalloc(sizeof (page_t *)
1320 		    * btopr(sptd->spt_amp->size), KM_SLEEP);
1321 		pl = pplist;
1322 
1323 		anon_index = seg_page(sptseg, spt_base);
1324 
1325 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1326 		for (a = spt_base; a < (spt_base + sptd->spt_amp->size);
1327 		    a += PAGESIZE, anon_index++, pplist++) {
1328 			ap = anon_get_ptr(amp->ahp, anon_index);
1329 			ASSERT(ap != NULL);
1330 			swap_xlate(ap, &vp, &off);
1331 			pp = page_lookup(vp, off, SE_SHARED);
1332 			ASSERT(pp != NULL);
1333 			*pplist = pp;
1334 		}
1335 		ANON_LOCK_EXIT(&amp->a_rwlock);
1336 
1337 		if (a < (spt_base + sptd->spt_amp->size)) {
1338 			ret = ENOTSUP;
1339 			goto insert_fail;
1340 		}
1341 		sptd->spt_ppa = pl;
1342 	} else {
1343 		/*
1344 		 * We already have a valid ppa[].
1345 		 */
1346 		pl = sptd->spt_ppa;
1347 	}
1348 
1349 	ASSERT(pl != NULL);
1350 
1351 	ret = seg_pinsert(seg, NULL, seg->s_base, sptd->spt_amp->size,
1352 	    sptd->spt_amp->size, pl, S_WRITE, SEGP_FORCE_WIRED,
1353 	    segspt_reclaim);
1354 	if (ret == SEGP_FAIL) {
1355 		/*
1356 		 * seg_pinsert failed. We return
1357 		 * ENOTSUP, so that the as_pagelock() code will
1358 		 * then try the slower F_SOFTLOCK path.
1359 		 */
1360 		if (pl_built) {
1361 			/*
1362 			 * No one else has referenced the ppa[].
1363 			 * We created it and we need to destroy it.
1364 			 */
1365 			sptd->spt_ppa = NULL;
1366 		}
1367 		ret = ENOTSUP;
1368 		goto insert_fail;
1369 	}
1370 
1371 	/*
1372 	 * In either case, we increment softlockcnt on the 'real' segment.
1373 	 */
1374 	sptd->spt_pcachecnt++;
1375 	atomic_inc_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
1376 
1377 	/*
1378 	 * We can now drop the sptd->spt_lock since the ppa[]
1379 	 * exists and we have incremented pacachecnt.
1380 	 */
1381 	mutex_exit(&sptd->spt_lock);
1382 
1383 	/*
1384 	 * Since we cache the entire segment, we want to
1385 	 * set ppp to point to the first slot that corresponds
1386 	 * to the requested addr, i.e. page_index.
1387 	 */
1388 	*ppp = &(sptd->spt_ppa[page_index]);
1389 	return (0);
1390 
1391 insert_fail:
1392 	/*
1393 	 * We will only reach this code if we tried and failed.
1394 	 *
1395 	 * And we can drop the lock on the dummy seg, once we've failed
1396 	 * to set up a new ppa[].
1397 	 */
1398 	mutex_exit(&sptd->spt_lock);
1399 
1400 	if (pl_built) {
1401 		/*
1402 		 * We created pl and we need to destroy it.
1403 		 */
1404 		pplist = pl;
1405 		np = (((uintptr_t)(a - spt_base)) >> PAGESHIFT);
1406 		while (np) {
1407 			page_unlock(*pplist);
1408 			np--;
1409 			pplist++;
1410 		}
1411 		kmem_free(pl, sizeof (page_t *) * btopr(sptd->spt_amp->size));
1412 	}
1413 	if (shmd->shm_softlockcnt <= 0) {
1414 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1415 			mutex_enter(&seg->s_as->a_contents);
1416 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1417 				AS_CLRUNMAPWAIT(seg->s_as);
1418 				cv_broadcast(&seg->s_as->a_cv);
1419 			}
1420 			mutex_exit(&seg->s_as->a_contents);
1421 		}
1422 	}
1423 	*ppp = NULL;
1424 	return (ret);
1425 }
1426 
1427 /*
1428  * purge any cached pages in the I/O page cache
1429  */
1430 static void
1431 segspt_purge(struct seg *seg)
1432 {
1433 	seg_ppurge(seg, NULL, SEGP_FORCE_WIRED);
1434 }
1435 
1436 static int
1437 segspt_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
1438     enum seg_rw rw, int async)
1439 {
1440 	struct seg *seg = (struct seg *)ptag;
1441 	struct	shm_data *shmd = (struct shm_data *)seg->s_data;
1442 	struct	seg	*sptseg;
1443 	struct	spt_data *sptd;
1444 	pgcnt_t npages, i, free_availrmem = 0;
1445 	int	done = 0;
1446 
1447 #ifdef lint
1448 	addr = addr;
1449 #endif
1450 	sptseg = shmd->shm_sptseg;
1451 	sptd = sptseg->s_data;
1452 	npages = (len >> PAGESHIFT);
1453 	ASSERT(npages);
1454 	ASSERT(sptd->spt_pcachecnt != 0);
1455 	ASSERT(sptd->spt_ppa == pplist);
1456 	ASSERT(npages == btopr(sptd->spt_amp->size));
1457 	ASSERT(async || AS_LOCK_HELD(seg->s_as));
1458 
1459 	/*
1460 	 * Acquire the lock on the dummy seg and destroy the
1461 	 * ppa array IF this is the last pcachecnt.
1462 	 */
1463 	mutex_enter(&sptd->spt_lock);
1464 	if (--sptd->spt_pcachecnt == 0) {
1465 		for (i = 0; i < npages; i++) {
1466 			if (pplist[i] == NULL) {
1467 				continue;
1468 			}
1469 			if (rw == S_WRITE) {
1470 				hat_setrefmod(pplist[i]);
1471 			} else {
1472 				hat_setref(pplist[i]);
1473 			}
1474 			if ((sptd->spt_flags & SHM_PAGEABLE) &&
1475 			    (sptd->spt_ppa_lckcnt[i] == 0))
1476 				free_availrmem++;
1477 			page_unlock(pplist[i]);
1478 		}
1479 		if ((sptd->spt_flags & SHM_PAGEABLE) && free_availrmem) {
1480 			mutex_enter(&freemem_lock);
1481 			availrmem += free_availrmem;
1482 			mutex_exit(&freemem_lock);
1483 		}
1484 		/*
1485 		 * Since we want to cach/uncache the entire ISM segment,
1486 		 * we will track the pplist in a segspt specific field
1487 		 * ppa, that is initialized at the time we add an entry to
1488 		 * the cache.
1489 		 */
1490 		ASSERT(sptd->spt_pcachecnt == 0);
1491 		kmem_free(pplist, sizeof (page_t *) * npages);
1492 		sptd->spt_ppa = NULL;
1493 		sptd->spt_flags &= ~DISM_PPA_CHANGED;
1494 		sptd->spt_gen++;
1495 		cv_broadcast(&sptd->spt_cv);
1496 		done = 1;
1497 	}
1498 	mutex_exit(&sptd->spt_lock);
1499 
1500 	/*
1501 	 * If we are pcache async thread or called via seg_ppurge_wiredpp() we
1502 	 * may not hold AS lock (in this case async argument is not 0). This
1503 	 * means if softlockcnt drops to 0 after the decrement below address
1504 	 * space may get freed. We can't allow it since after softlock
1505 	 * derement to 0 we still need to access as structure for possible
1506 	 * wakeup of unmap waiters. To prevent the disappearance of as we take
1507 	 * this segment's shm_segfree_syncmtx. segspt_shmfree() also takes
1508 	 * this mutex as a barrier to make sure this routine completes before
1509 	 * segment is freed.
1510 	 *
1511 	 * The second complication we have to deal with in async case is a
1512 	 * possibility of missed wake up of unmap wait thread. When we don't
1513 	 * hold as lock here we may take a_contents lock before unmap wait
1514 	 * thread that was first to see softlockcnt was still not 0. As a
1515 	 * result we'll fail to wake up an unmap wait thread. To avoid this
1516 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
1517 	 * to 0 if async is not 0.  unmapwait thread
1518 	 * will not block if this flag is set.
1519 	 */
1520 	if (async)
1521 		mutex_enter(&shmd->shm_segfree_syncmtx);
1522 
1523 	/*
1524 	 * Now decrement softlockcnt.
1525 	 */
1526 	ASSERT(shmd->shm_softlockcnt > 0);
1527 	atomic_dec_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
1528 
1529 	if (shmd->shm_softlockcnt <= 0) {
1530 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
1531 			mutex_enter(&seg->s_as->a_contents);
1532 			if (async)
1533 				AS_SETNOUNMAPWAIT(seg->s_as);
1534 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1535 				AS_CLRUNMAPWAIT(seg->s_as);
1536 				cv_broadcast(&seg->s_as->a_cv);
1537 			}
1538 			mutex_exit(&seg->s_as->a_contents);
1539 		}
1540 	}
1541 
1542 	if (async)
1543 		mutex_exit(&shmd->shm_segfree_syncmtx);
1544 
1545 	return (done);
1546 }
1547 
1548 /*
1549  * Do a F_SOFTUNLOCK call over the range requested.
1550  * The range must have already been F_SOFTLOCK'ed.
1551  *
1552  * The calls to acquire and release the anon map lock mutex were
1553  * removed in order to avoid a deadly embrace during a DR
1554  * memory delete operation.  (Eg. DR blocks while waiting for a
1555  * exclusive lock on a page that is being used for kaio; the
1556  * thread that will complete the kaio and call segspt_softunlock
1557  * blocks on the anon map lock; another thread holding the anon
1558  * map lock blocks on another page lock via the segspt_shmfault
1559  * -> page_lookup -> page_lookup_create -> page_lock_es code flow.)
1560  *
1561  * The appropriateness of the removal is based upon the following:
1562  * 1. If we are holding a segment's reader lock and the page is held
1563  * shared, then the corresponding element in anonmap which points to
1564  * anon struct cannot change and there is no need to acquire the
1565  * anonymous map lock.
1566  * 2. Threads in segspt_softunlock have a reader lock on the segment
1567  * and already have the shared page lock, so we are guaranteed that
1568  * the anon map slot cannot change and therefore can call anon_get_ptr()
1569  * without grabbing the anonymous map lock.
1570  * 3. Threads that softlock a shared page break copy-on-write, even if
1571  * its a read.  Thus cow faults can be ignored with respect to soft
1572  * unlocking, since the breaking of cow means that the anon slot(s) will
1573  * not be shared.
1574  */
1575 static void
1576 segspt_softunlock(struct seg *seg, caddr_t sptseg_addr,
1577     size_t len, enum seg_rw rw)
1578 {
1579 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1580 	struct seg	*sptseg;
1581 	struct spt_data *sptd;
1582 	page_t *pp;
1583 	caddr_t adr;
1584 	struct vnode *vp;
1585 	u_offset_t offset;
1586 	ulong_t anon_index;
1587 	struct anon_map *amp;		/* XXX - for locknest */
1588 	struct anon *ap = NULL;
1589 	pgcnt_t npages;
1590 
1591 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1592 
1593 	sptseg = shmd->shm_sptseg;
1594 	sptd = sptseg->s_data;
1595 
1596 	/*
1597 	 * Some platforms assume that ISM mappings are HAT_LOAD_LOCK
1598 	 * and therefore their pages are SE_SHARED locked
1599 	 * for the entire life of the segment.
1600 	 */
1601 	if ((!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) &&
1602 	    ((sptd->spt_flags & SHM_PAGEABLE) == 0)) {
1603 		goto softlock_decrement;
1604 	}
1605 
1606 	/*
1607 	 * Any thread is free to do a page_find and
1608 	 * page_unlock() on the pages within this seg.
1609 	 *
1610 	 * We are already holding the as->a_lock on the user's
1611 	 * real segment, but we need to hold the a_lock on the
1612 	 * underlying dummy as. This is mostly to satisfy the
1613 	 * underlying HAT layer.
1614 	 */
1615 	AS_LOCK_ENTER(sptseg->s_as, RW_READER);
1616 	hat_unlock(sptseg->s_as->a_hat, sptseg_addr, len);
1617 	AS_LOCK_EXIT(sptseg->s_as);
1618 
1619 	amp = sptd->spt_amp;
1620 	ASSERT(amp != NULL);
1621 	anon_index = seg_page(sptseg, sptseg_addr);
1622 
1623 	for (adr = sptseg_addr; adr < sptseg_addr + len; adr += PAGESIZE) {
1624 		ap = anon_get_ptr(amp->ahp, anon_index++);
1625 		ASSERT(ap != NULL);
1626 		swap_xlate(ap, &vp, &offset);
1627 
1628 		/*
1629 		 * Use page_find() instead of page_lookup() to
1630 		 * find the page since we know that it has a
1631 		 * "shared" lock.
1632 		 */
1633 		pp = page_find(vp, offset);
1634 		ASSERT(ap == anon_get_ptr(amp->ahp, anon_index - 1));
1635 		if (pp == NULL) {
1636 			panic("segspt_softunlock: "
1637 			    "addr %p, ap %p, vp %p, off %llx",
1638 			    (void *)adr, (void *)ap, (void *)vp, offset);
1639 			/*NOTREACHED*/
1640 		}
1641 
1642 		if (rw == S_WRITE) {
1643 			hat_setrefmod(pp);
1644 		} else if (rw != S_OTHER) {
1645 			hat_setref(pp);
1646 		}
1647 		page_unlock(pp);
1648 	}
1649 
1650 softlock_decrement:
1651 	npages = btopr(len);
1652 	ASSERT(shmd->shm_softlockcnt >= npages);
1653 	atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), -npages);
1654 	if (shmd->shm_softlockcnt == 0) {
1655 		/*
1656 		 * All SOFTLOCKS are gone. Wakeup any waiting
1657 		 * unmappers so they can try again to unmap.
1658 		 * Check for waiters first without the mutex
1659 		 * held so we don't always grab the mutex on
1660 		 * softunlocks.
1661 		 */
1662 		if (AS_ISUNMAPWAIT(seg->s_as)) {
1663 			mutex_enter(&seg->s_as->a_contents);
1664 			if (AS_ISUNMAPWAIT(seg->s_as)) {
1665 				AS_CLRUNMAPWAIT(seg->s_as);
1666 				cv_broadcast(&seg->s_as->a_cv);
1667 			}
1668 			mutex_exit(&seg->s_as->a_contents);
1669 		}
1670 	}
1671 }
1672 
1673 int
1674 segspt_shmattach(struct seg *seg, caddr_t *argsp)
1675 {
1676 	struct shm_data *shmd_arg = (struct shm_data *)argsp;
1677 	struct shm_data *shmd;
1678 	struct anon_map *shm_amp = shmd_arg->shm_amp;
1679 	struct spt_data *sptd;
1680 	int error = 0;
1681 
1682 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
1683 
1684 	shmd = kmem_zalloc((sizeof (*shmd)), KM_NOSLEEP);
1685 	if (shmd == NULL)
1686 		return (ENOMEM);
1687 
1688 	shmd->shm_sptas = shmd_arg->shm_sptas;
1689 	shmd->shm_amp = shm_amp;
1690 	shmd->shm_sptseg = shmd_arg->shm_sptseg;
1691 
1692 	(void) lgrp_shm_policy_set(LGRP_MEM_POLICY_DEFAULT, shm_amp, 0,
1693 	    NULL, 0, seg->s_size);
1694 
1695 	mutex_init(&shmd->shm_segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
1696 
1697 	seg->s_data = (void *)shmd;
1698 	seg->s_ops = &segspt_shmops;
1699 	seg->s_szc = shmd->shm_sptseg->s_szc;
1700 	sptd = shmd->shm_sptseg->s_data;
1701 
1702 	if (sptd->spt_flags & SHM_PAGEABLE) {
1703 		if ((shmd->shm_vpage = kmem_zalloc(btopr(shm_amp->size),
1704 		    KM_NOSLEEP)) == NULL) {
1705 			seg->s_data = (void *)NULL;
1706 			kmem_free(shmd, (sizeof (*shmd)));
1707 			return (ENOMEM);
1708 		}
1709 		shmd->shm_lckpgs = 0;
1710 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
1711 			if ((error = hat_share(seg->s_as->a_hat, seg->s_base,
1712 			    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1713 			    seg->s_size, seg->s_szc)) != 0) {
1714 				kmem_free(shmd->shm_vpage,
1715 				    btopr(shm_amp->size));
1716 			}
1717 		}
1718 	} else {
1719 		error = hat_share(seg->s_as->a_hat, seg->s_base,
1720 		    shmd_arg->shm_sptas->a_hat, SEGSPTADDR,
1721 		    seg->s_size, seg->s_szc);
1722 	}
1723 	if (error) {
1724 		seg->s_szc = 0;
1725 		seg->s_data = (void *)NULL;
1726 		kmem_free(shmd, (sizeof (*shmd)));
1727 	} else {
1728 		ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1729 		shm_amp->refcnt++;
1730 		ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1731 	}
1732 	return (error);
1733 }
1734 
1735 int
1736 segspt_shmunmap(struct seg *seg, caddr_t raddr, size_t ssize)
1737 {
1738 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1739 	int reclaim = 1;
1740 
1741 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
1742 retry:
1743 	if (shmd->shm_softlockcnt > 0) {
1744 		if (reclaim == 1) {
1745 			segspt_purge(seg);
1746 			reclaim = 0;
1747 			goto retry;
1748 		}
1749 		return (EAGAIN);
1750 	}
1751 
1752 	if (ssize != seg->s_size) {
1753 #ifdef DEBUG
1754 		cmn_err(CE_WARN, "Incompatible ssize %lx s_size %lx\n",
1755 		    ssize, seg->s_size);
1756 #endif
1757 		return (EINVAL);
1758 	}
1759 
1760 	(void) segspt_shmlockop(seg, raddr, shmd->shm_amp->size, 0, MC_UNLOCK,
1761 	    NULL, 0);
1762 	hat_unshare(seg->s_as->a_hat, raddr, ssize, seg->s_szc);
1763 
1764 	seg_free(seg);
1765 
1766 	return (0);
1767 }
1768 
1769 void
1770 segspt_shmfree(struct seg *seg)
1771 {
1772 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
1773 	struct anon_map *shm_amp = shmd->shm_amp;
1774 
1775 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
1776 
1777 	(void) segspt_shmlockop(seg, seg->s_base, shm_amp->size, 0,
1778 	    MC_UNLOCK, NULL, 0);
1779 
1780 	/*
1781 	 * Need to increment refcnt when attaching
1782 	 * and decrement when detaching because of dup().
1783 	 */
1784 	ANON_LOCK_ENTER(&shm_amp->a_rwlock, RW_WRITER);
1785 	shm_amp->refcnt--;
1786 	ANON_LOCK_EXIT(&shm_amp->a_rwlock);
1787 
1788 	if (shmd->shm_vpage) {	/* only for DISM */
1789 		kmem_free(shmd->shm_vpage, btopr(shm_amp->size));
1790 		shmd->shm_vpage = NULL;
1791 	}
1792 
1793 	/*
1794 	 * Take shm_segfree_syncmtx lock to let segspt_reclaim() finish if it's
1795 	 * still working with this segment without holding as lock.
1796 	 */
1797 	ASSERT(shmd->shm_softlockcnt == 0);
1798 	mutex_enter(&shmd->shm_segfree_syncmtx);
1799 	mutex_destroy(&shmd->shm_segfree_syncmtx);
1800 
1801 	kmem_free(shmd, sizeof (*shmd));
1802 }
1803 
1804 /*ARGSUSED*/
1805 int
1806 segspt_shmsetprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
1807 {
1808 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1809 
1810 	/*
1811 	 * Shared page table is more than shared mapping.
1812 	 *  Individual process sharing page tables can't change prot
1813 	 *  because there is only one set of page tables.
1814 	 *  This will be allowed after private page table is
1815 	 *  supported.
1816 	 */
1817 /* need to return correct status error? */
1818 	return (0);
1819 }
1820 
1821 
1822 faultcode_t
1823 segspt_dismfault(struct hat *hat, struct seg *seg, caddr_t addr,
1824     size_t len, enum fault_type type, enum seg_rw rw)
1825 {
1826 	struct  shm_data 	*shmd = (struct shm_data *)seg->s_data;
1827 	struct  seg		*sptseg = shmd->shm_sptseg;
1828 	struct  as		*curspt = shmd->shm_sptas;
1829 	struct  spt_data 	*sptd = sptseg->s_data;
1830 	pgcnt_t npages;
1831 	size_t  size;
1832 	caddr_t segspt_addr, shm_addr;
1833 	page_t  **ppa;
1834 	int	i;
1835 	ulong_t an_idx = 0;
1836 	int	err = 0;
1837 	int	dyn_ism_unmap = hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0);
1838 	size_t	pgsz;
1839 	pgcnt_t	pgcnt;
1840 	caddr_t	a;
1841 	pgcnt_t	pidx;
1842 
1843 #ifdef lint
1844 	hat = hat;
1845 #endif
1846 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
1847 
1848 	/*
1849 	 * Because of the way spt is implemented
1850 	 * the realsize of the segment does not have to be
1851 	 * equal to the segment size itself. The segment size is
1852 	 * often in multiples of a page size larger than PAGESIZE.
1853 	 * The realsize is rounded up to the nearest PAGESIZE
1854 	 * based on what the user requested. This is a bit of
1855 	 * ungliness that is historical but not easily fixed
1856 	 * without re-designing the higher levels of ISM.
1857 	 */
1858 	ASSERT(addr >= seg->s_base);
1859 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
1860 		return (FC_NOMAP);
1861 	/*
1862 	 * For all of the following cases except F_PROT, we need to
1863 	 * make any necessary adjustments to addr and len
1864 	 * and get all of the necessary page_t's into an array called ppa[].
1865 	 *
1866 	 * The code in shmat() forces base addr and len of ISM segment
1867 	 * to be aligned to largest page size supported. Therefore,
1868 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
1869 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
1870 	 * in large pagesize chunks, or else we will screw up the HAT
1871 	 * layer by calling hat_memload_array() with differing page sizes
1872 	 * over a given virtual range.
1873 	 */
1874 	pgsz = page_get_pagesize(sptseg->s_szc);
1875 	pgcnt = page_get_pagecnt(sptseg->s_szc);
1876 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
1877 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
1878 	npages = btopr(size);
1879 
1880 	/*
1881 	 * Now we need to convert from addr in segshm to addr in segspt.
1882 	 */
1883 	an_idx = seg_page(seg, shm_addr);
1884 	segspt_addr = sptseg->s_base + ptob(an_idx);
1885 
1886 	ASSERT((segspt_addr + ptob(npages)) <=
1887 	    (sptseg->s_base + sptd->spt_realsize));
1888 	ASSERT(segspt_addr < (sptseg->s_base + sptseg->s_size));
1889 
1890 	switch (type) {
1891 
1892 	case F_SOFTLOCK:
1893 
1894 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
1895 		/*
1896 		 * Fall through to the F_INVAL case to load up the hat layer
1897 		 * entries with the HAT_LOAD_LOCK flag.
1898 		 */
1899 		/* FALLTHRU */
1900 	case F_INVAL:
1901 
1902 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
1903 			return (FC_NOMAP);
1904 
1905 		ppa = kmem_zalloc(npages * sizeof (page_t *), KM_SLEEP);
1906 
1907 		err = spt_anon_getpages(sptseg, segspt_addr, size, ppa);
1908 		if (err != 0) {
1909 			if (type == F_SOFTLOCK) {
1910 				atomic_add_long((ulong_t *)(
1911 				    &(shmd->shm_softlockcnt)), -npages);
1912 			}
1913 			goto dism_err;
1914 		}
1915 		AS_LOCK_ENTER(sptseg->s_as, RW_READER);
1916 		a = segspt_addr;
1917 		pidx = 0;
1918 		if (type == F_SOFTLOCK) {
1919 
1920 			/*
1921 			 * Load up the translation keeping it
1922 			 * locked and don't unlock the page.
1923 			 */
1924 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
1925 				hat_memload_array(sptseg->s_as->a_hat,
1926 				    a, pgsz, &ppa[pidx], sptd->spt_prot,
1927 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
1928 			}
1929 		} else {
1930 			/*
1931 			 * Migrate pages marked for migration
1932 			 */
1933 			if (lgrp_optimizations())
1934 				page_migrate(seg, shm_addr, ppa, npages);
1935 
1936 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
1937 				hat_memload_array(sptseg->s_as->a_hat,
1938 				    a, pgsz, &ppa[pidx],
1939 				    sptd->spt_prot,
1940 				    HAT_LOAD_SHARE);
1941 			}
1942 
1943 			/*
1944 			 * And now drop the SE_SHARED lock(s).
1945 			 */
1946 			if (dyn_ism_unmap) {
1947 				for (i = 0; i < npages; i++) {
1948 					page_unlock(ppa[i]);
1949 				}
1950 			}
1951 		}
1952 
1953 		if (!dyn_ism_unmap) {
1954 			if (hat_share(seg->s_as->a_hat, shm_addr,
1955 			    curspt->a_hat, segspt_addr, ptob(npages),
1956 			    seg->s_szc) != 0) {
1957 				panic("hat_share err in DISM fault");
1958 				/* NOTREACHED */
1959 			}
1960 			if (type == F_INVAL) {
1961 				for (i = 0; i < npages; i++) {
1962 					page_unlock(ppa[i]);
1963 				}
1964 			}
1965 		}
1966 		AS_LOCK_EXIT(sptseg->s_as);
1967 dism_err:
1968 		kmem_free(ppa, npages * sizeof (page_t *));
1969 		return (err);
1970 
1971 	case F_SOFTUNLOCK:
1972 
1973 		/*
1974 		 * This is a bit ugly, we pass in the real seg pointer,
1975 		 * but the segspt_addr is the virtual address within the
1976 		 * dummy seg.
1977 		 */
1978 		segspt_softunlock(seg, segspt_addr, size, rw);
1979 		return (0);
1980 
1981 	case F_PROT:
1982 
1983 		/*
1984 		 * This takes care of the unusual case where a user
1985 		 * allocates a stack in shared memory and a register
1986 		 * window overflow is written to that stack page before
1987 		 * it is otherwise modified.
1988 		 *
1989 		 * We can get away with this because ISM segments are
1990 		 * always rw. Other than this unusual case, there
1991 		 * should be no instances of protection violations.
1992 		 */
1993 		return (0);
1994 
1995 	default:
1996 #ifdef DEBUG
1997 		panic("segspt_dismfault default type?");
1998 #else
1999 		return (FC_NOMAP);
2000 #endif
2001 	}
2002 }
2003 
2004 
2005 faultcode_t
2006 segspt_shmfault(struct hat *hat, struct seg *seg, caddr_t addr,
2007     size_t len, enum fault_type type, enum seg_rw rw)
2008 {
2009 	struct shm_data 	*shmd = (struct shm_data *)seg->s_data;
2010 	struct seg		*sptseg = shmd->shm_sptseg;
2011 	struct as		*curspt = shmd->shm_sptas;
2012 	struct spt_data 	*sptd   = sptseg->s_data;
2013 	pgcnt_t npages;
2014 	size_t size;
2015 	caddr_t sptseg_addr, shm_addr;
2016 	page_t *pp, **ppa;
2017 	int	i;
2018 	u_offset_t offset;
2019 	ulong_t anon_index = 0;
2020 	struct vnode *vp;
2021 	struct anon_map *amp;		/* XXX - for locknest */
2022 	struct anon *ap = NULL;
2023 	size_t		pgsz;
2024 	pgcnt_t		pgcnt;
2025 	caddr_t		a;
2026 	pgcnt_t		pidx;
2027 	size_t		sz;
2028 
2029 #ifdef lint
2030 	hat = hat;
2031 #endif
2032 
2033 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2034 
2035 	if (sptd->spt_flags & SHM_PAGEABLE) {
2036 		return (segspt_dismfault(hat, seg, addr, len, type, rw));
2037 	}
2038 
2039 	/*
2040 	 * Because of the way spt is implemented
2041 	 * the realsize of the segment does not have to be
2042 	 * equal to the segment size itself. The segment size is
2043 	 * often in multiples of a page size larger than PAGESIZE.
2044 	 * The realsize is rounded up to the nearest PAGESIZE
2045 	 * based on what the user requested. This is a bit of
2046 	 * ungliness that is historical but not easily fixed
2047 	 * without re-designing the higher levels of ISM.
2048 	 */
2049 	ASSERT(addr >= seg->s_base);
2050 	if (((addr + len) - seg->s_base) > sptd->spt_realsize)
2051 		return (FC_NOMAP);
2052 	/*
2053 	 * For all of the following cases except F_PROT, we need to
2054 	 * make any necessary adjustments to addr and len
2055 	 * and get all of the necessary page_t's into an array called ppa[].
2056 	 *
2057 	 * The code in shmat() forces base addr and len of ISM segment
2058 	 * to be aligned to largest page size supported. Therefore,
2059 	 * we are able to handle F_SOFTLOCK and F_INVAL calls in "large
2060 	 * pagesize" chunks. We want to make sure that we HAT_LOAD_LOCK
2061 	 * in large pagesize chunks, or else we will screw up the HAT
2062 	 * layer by calling hat_memload_array() with differing page sizes
2063 	 * over a given virtual range.
2064 	 */
2065 	pgsz = page_get_pagesize(sptseg->s_szc);
2066 	pgcnt = page_get_pagecnt(sptseg->s_szc);
2067 	shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);
2068 	size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)), pgsz);
2069 	npages = btopr(size);
2070 
2071 	/*
2072 	 * Now we need to convert from addr in segshm to addr in segspt.
2073 	 */
2074 	anon_index = seg_page(seg, shm_addr);
2075 	sptseg_addr = sptseg->s_base + ptob(anon_index);
2076 
2077 	/*
2078 	 * And now we may have to adjust npages downward if we have
2079 	 * exceeded the realsize of the segment or initial anon
2080 	 * allocations.
2081 	 */
2082 	if ((sptseg_addr + ptob(npages)) >
2083 	    (sptseg->s_base + sptd->spt_realsize))
2084 		size = (sptseg->s_base + sptd->spt_realsize) - sptseg_addr;
2085 
2086 	npages = btopr(size);
2087 
2088 	ASSERT(sptseg_addr < (sptseg->s_base + sptseg->s_size));
2089 	ASSERT((sptd->spt_flags & SHM_PAGEABLE) == 0);
2090 
2091 	switch (type) {
2092 
2093 	case F_SOFTLOCK:
2094 
2095 		/*
2096 		 * availrmem is decremented once during anon_swap_adjust()
2097 		 * and is incremented during the anon_unresv(), which is
2098 		 * called from shm_rm_amp() when the segment is destroyed.
2099 		 */
2100 		atomic_add_long((ulong_t *)(&(shmd->shm_softlockcnt)), npages);
2101 		/*
2102 		 * Some platforms assume that ISM pages are SE_SHARED
2103 		 * locked for the entire life of the segment.
2104 		 */
2105 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0))
2106 			return (0);
2107 		/*
2108 		 * Fall through to the F_INVAL case to load up the hat layer
2109 		 * entries with the HAT_LOAD_LOCK flag.
2110 		 */
2111 
2112 		/* FALLTHRU */
2113 	case F_INVAL:
2114 
2115 		if ((rw == S_EXEC) && !(sptd->spt_prot & PROT_EXEC))
2116 			return (FC_NOMAP);
2117 
2118 		/*
2119 		 * Some platforms that do NOT support DYNAMIC_ISM_UNMAP
2120 		 * may still rely on this call to hat_share(). That
2121 		 * would imply that those hat's can fault on a
2122 		 * HAT_LOAD_LOCK translation, which would seem
2123 		 * contradictory.
2124 		 */
2125 		if (!hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2126 			if (hat_share(seg->s_as->a_hat, seg->s_base,
2127 			    curspt->a_hat, sptseg->s_base,
2128 			    sptseg->s_size, sptseg->s_szc) != 0) {
2129 				panic("hat_share error in ISM fault");
2130 				/*NOTREACHED*/
2131 			}
2132 			return (0);
2133 		}
2134 		ppa = kmem_zalloc(sizeof (page_t *) * npages, KM_SLEEP);
2135 
2136 		/*
2137 		 * I see no need to lock the real seg,
2138 		 * here, because all of our work will be on the underlying
2139 		 * dummy seg.
2140 		 *
2141 		 * sptseg_addr and npages now account for large pages.
2142 		 */
2143 		amp = sptd->spt_amp;
2144 		ASSERT(amp != NULL);
2145 		anon_index = seg_page(sptseg, sptseg_addr);
2146 
2147 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2148 		for (i = 0; i < npages; i++) {
2149 			ap = anon_get_ptr(amp->ahp, anon_index++);
2150 			ASSERT(ap != NULL);
2151 			swap_xlate(ap, &vp, &offset);
2152 			pp = page_lookup(vp, offset, SE_SHARED);
2153 			ASSERT(pp != NULL);
2154 			ppa[i] = pp;
2155 		}
2156 		ANON_LOCK_EXIT(&amp->a_rwlock);
2157 		ASSERT(i == npages);
2158 
2159 		/*
2160 		 * We are already holding the as->a_lock on the user's
2161 		 * real segment, but we need to hold the a_lock on the
2162 		 * underlying dummy as. This is mostly to satisfy the
2163 		 * underlying HAT layer.
2164 		 */
2165 		AS_LOCK_ENTER(sptseg->s_as, RW_READER);
2166 		a = sptseg_addr;
2167 		pidx = 0;
2168 		if (type == F_SOFTLOCK) {
2169 			/*
2170 			 * Load up the translation keeping it
2171 			 * locked and don't unlock the page.
2172 			 */
2173 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
2174 				sz = MIN(pgsz, ptob(npages - pidx));
2175 				hat_memload_array(sptseg->s_as->a_hat, a,
2176 				    sz, &ppa[pidx], sptd->spt_prot,
2177 				    HAT_LOAD_LOCK | HAT_LOAD_SHARE);
2178 			}
2179 		} else {
2180 			/*
2181 			 * Migrate pages marked for migration.
2182 			 */
2183 			if (lgrp_optimizations())
2184 				page_migrate(seg, shm_addr, ppa, npages);
2185 
2186 			for (; pidx < npages; a += pgsz, pidx += pgcnt) {
2187 				sz = MIN(pgsz, ptob(npages - pidx));
2188 				hat_memload_array(sptseg->s_as->a_hat,
2189 				    a, sz, &ppa[pidx],
2190 				    sptd->spt_prot, HAT_LOAD_SHARE);
2191 			}
2192 
2193 			/*
2194 			 * And now drop the SE_SHARED lock(s).
2195 			 */
2196 			for (i = 0; i < npages; i++)
2197 				page_unlock(ppa[i]);
2198 		}
2199 		AS_LOCK_EXIT(sptseg->s_as);
2200 
2201 		kmem_free(ppa, sizeof (page_t *) * npages);
2202 		return (0);
2203 	case F_SOFTUNLOCK:
2204 
2205 		/*
2206 		 * This is a bit ugly, we pass in the real seg pointer,
2207 		 * but the sptseg_addr is the virtual address within the
2208 		 * dummy seg.
2209 		 */
2210 		segspt_softunlock(seg, sptseg_addr, ptob(npages), rw);
2211 		return (0);
2212 
2213 	case F_PROT:
2214 
2215 		/*
2216 		 * This takes care of the unusual case where a user
2217 		 * allocates a stack in shared memory and a register
2218 		 * window overflow is written to that stack page before
2219 		 * it is otherwise modified.
2220 		 *
2221 		 * We can get away with this because ISM segments are
2222 		 * always rw. Other than this unusual case, there
2223 		 * should be no instances of protection violations.
2224 		 */
2225 		return (0);
2226 
2227 	default:
2228 #ifdef DEBUG
2229 		cmn_err(CE_WARN, "segspt_shmfault default type?");
2230 #endif
2231 		return (FC_NOMAP);
2232 	}
2233 }
2234 
2235 /*ARGSUSED*/
2236 static faultcode_t
2237 segspt_shmfaulta(struct seg *seg, caddr_t addr)
2238 {
2239 	return (0);
2240 }
2241 
2242 /*ARGSUSED*/
2243 static int
2244 segspt_shmkluster(struct seg *seg, caddr_t addr, ssize_t delta)
2245 {
2246 	return (0);
2247 }
2248 
2249 /*ARGSUSED*/
2250 static size_t
2251 segspt_shmswapout(struct seg *seg)
2252 {
2253 	return (0);
2254 }
2255 
2256 /*
2257  * duplicate the shared page tables
2258  */
2259 int
2260 segspt_shmdup(struct seg *seg, struct seg *newseg)
2261 {
2262 	struct shm_data		*shmd = (struct shm_data *)seg->s_data;
2263 	struct anon_map 	*amp = shmd->shm_amp;
2264 	struct shm_data 	*shmd_new;
2265 	struct seg		*spt_seg = shmd->shm_sptseg;
2266 	struct spt_data		*sptd = spt_seg->s_data;
2267 	int			error = 0;
2268 
2269 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as));
2270 
2271 	shmd_new = kmem_zalloc((sizeof (*shmd_new)), KM_SLEEP);
2272 	newseg->s_data = (void *)shmd_new;
2273 	shmd_new->shm_sptas = shmd->shm_sptas;
2274 	shmd_new->shm_amp = amp;
2275 	shmd_new->shm_sptseg = shmd->shm_sptseg;
2276 	newseg->s_ops = &segspt_shmops;
2277 	newseg->s_szc = seg->s_szc;
2278 	ASSERT(seg->s_szc == shmd->shm_sptseg->s_szc);
2279 
2280 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2281 	amp->refcnt++;
2282 	ANON_LOCK_EXIT(&amp->a_rwlock);
2283 
2284 	if (sptd->spt_flags & SHM_PAGEABLE) {
2285 		shmd_new->shm_vpage = kmem_zalloc(btopr(amp->size), KM_SLEEP);
2286 		shmd_new->shm_lckpgs = 0;
2287 		if (hat_supported(HAT_DYNAMIC_ISM_UNMAP, (void *)0)) {
2288 			if ((error = hat_share(newseg->s_as->a_hat,
2289 			    newseg->s_base, shmd->shm_sptas->a_hat, SEGSPTADDR,
2290 			    seg->s_size, seg->s_szc)) != 0) {
2291 				kmem_free(shmd_new->shm_vpage,
2292 				    btopr(amp->size));
2293 			}
2294 		}
2295 		return (error);
2296 	} else {
2297 		return (hat_share(newseg->s_as->a_hat, newseg->s_base,
2298 		    shmd->shm_sptas->a_hat, SEGSPTADDR, seg->s_size,
2299 		    seg->s_szc));
2300 
2301 	}
2302 }
2303 
2304 /*ARGSUSED*/
2305 int
2306 segspt_shmcheckprot(struct seg *seg, caddr_t addr, size_t size, uint_t prot)
2307 {
2308 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2309 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2310 
2311 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2312 
2313 	/*
2314 	 * ISM segment is always rw.
2315 	 */
2316 	return (((sptd->spt_prot & prot) != prot) ? EACCES : 0);
2317 }
2318 
2319 /*
2320  * Return an array of locked large pages, for empty slots allocate
2321  * private zero-filled anon pages.
2322  */
2323 static int
2324 spt_anon_getpages(
2325 	struct seg *sptseg,
2326 	caddr_t sptaddr,
2327 	size_t len,
2328 	page_t *ppa[])
2329 {
2330 	struct  spt_data *sptd = sptseg->s_data;
2331 	struct  anon_map *amp = sptd->spt_amp;
2332 	enum 	seg_rw rw = sptd->spt_prot;
2333 	uint_t	szc = sptseg->s_szc;
2334 	size_t	pg_sz, share_sz = page_get_pagesize(szc);
2335 	pgcnt_t	lp_npgs;
2336 	caddr_t	lp_addr, e_sptaddr;
2337 	uint_t	vpprot, ppa_szc = 0;
2338 	struct  vpage *vpage = NULL;
2339 	ulong_t	j, ppa_idx;
2340 	int	err, ierr = 0;
2341 	pgcnt_t	an_idx;
2342 	anon_sync_obj_t cookie;
2343 	int anon_locked = 0;
2344 	pgcnt_t amp_pgs;
2345 
2346 
2347 	ASSERT(IS_P2ALIGNED(sptaddr, share_sz) && IS_P2ALIGNED(len, share_sz));
2348 	ASSERT(len != 0);
2349 
2350 	pg_sz = share_sz;
2351 	lp_npgs = btop(pg_sz);
2352 	lp_addr = sptaddr;
2353 	e_sptaddr = sptaddr + len;
2354 	an_idx = seg_page(sptseg, sptaddr);
2355 	ppa_idx = 0;
2356 
2357 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2358 
2359 	amp_pgs = page_get_pagecnt(amp->a_szc);
2360 
2361 	/*CONSTCOND*/
2362 	while (1) {
2363 		for (; lp_addr < e_sptaddr;
2364 		    an_idx += lp_npgs, lp_addr += pg_sz, ppa_idx += lp_npgs) {
2365 
2366 			/*
2367 			 * If we're currently locked, and we get to a new
2368 			 * page, unlock our current anon chunk.
2369 			 */
2370 			if (anon_locked && P2PHASE(an_idx, amp_pgs) == 0) {
2371 				anon_array_exit(&cookie);
2372 				anon_locked = 0;
2373 			}
2374 			if (!anon_locked) {
2375 				anon_array_enter(amp, an_idx, &cookie);
2376 				anon_locked = 1;
2377 			}
2378 			ppa_szc = (uint_t)-1;
2379 			ierr = anon_map_getpages(amp, an_idx, szc, sptseg,
2380 			    lp_addr, sptd->spt_prot, &vpprot, &ppa[ppa_idx],
2381 			    &ppa_szc, vpage, rw, 0, segvn_anypgsz, 0, kcred);
2382 
2383 			if (ierr != 0) {
2384 				if (ierr > 0) {
2385 					err = FC_MAKE_ERR(ierr);
2386 					goto lpgs_err;
2387 				}
2388 				break;
2389 			}
2390 		}
2391 		if (lp_addr == e_sptaddr) {
2392 			break;
2393 		}
2394 		ASSERT(lp_addr < e_sptaddr);
2395 
2396 		/*
2397 		 * ierr == -1 means we failed to allocate a large page.
2398 		 * so do a size down operation.
2399 		 *
2400 		 * ierr == -2 means some other process that privately shares
2401 		 * pages with this process has allocated a larger page and we
2402 		 * need to retry with larger pages. So do a size up
2403 		 * operation. This relies on the fact that large pages are
2404 		 * never partially shared i.e. if we share any constituent
2405 		 * page of a large page with another process we must share the
2406 		 * entire large page. Note this cannot happen for SOFTLOCK
2407 		 * case, unless current address (lpaddr) is at the beginning
2408 		 * of the next page size boundary because the other process
2409 		 * couldn't have relocated locked pages.
2410 		 */
2411 		ASSERT(ierr == -1 || ierr == -2);
2412 		if (segvn_anypgsz) {
2413 			ASSERT(ierr == -2 || szc != 0);
2414 			ASSERT(ierr == -1 || szc < sptseg->s_szc);
2415 			szc = (ierr == -1) ? szc - 1 : szc + 1;
2416 		} else {
2417 			/*
2418 			 * For faults and segvn_anypgsz == 0
2419 			 * we need to be careful not to loop forever
2420 			 * if existing page is found with szc other
2421 			 * than 0 or seg->s_szc. This could be due
2422 			 * to page relocations on behalf of DR or
2423 			 * more likely large page creation. For this
2424 			 * case simply re-size to existing page's szc
2425 			 * if returned by anon_map_getpages().
2426 			 */
2427 			if (ppa_szc == (uint_t)-1) {
2428 				szc = (ierr == -1) ? 0 : sptseg->s_szc;
2429 			} else {
2430 				ASSERT(ppa_szc <= sptseg->s_szc);
2431 				ASSERT(ierr == -2 || ppa_szc < szc);
2432 				ASSERT(ierr == -1 || ppa_szc > szc);
2433 				szc = ppa_szc;
2434 			}
2435 		}
2436 		pg_sz = page_get_pagesize(szc);
2437 		lp_npgs = btop(pg_sz);
2438 		ASSERT(IS_P2ALIGNED(lp_addr, pg_sz));
2439 	}
2440 	if (anon_locked) {
2441 		anon_array_exit(&cookie);
2442 	}
2443 	ANON_LOCK_EXIT(&amp->a_rwlock);
2444 	return (0);
2445 
2446 lpgs_err:
2447 	if (anon_locked) {
2448 		anon_array_exit(&cookie);
2449 	}
2450 	ANON_LOCK_EXIT(&amp->a_rwlock);
2451 	for (j = 0; j < ppa_idx; j++)
2452 		page_unlock(ppa[j]);
2453 	return (err);
2454 }
2455 
2456 /*
2457  * count the number of bytes in a set of spt pages that are currently not
2458  * locked
2459  */
2460 static rctl_qty_t
2461 spt_unlockedbytes(pgcnt_t npages, page_t **ppa)
2462 {
2463 	ulong_t	i;
2464 	rctl_qty_t unlocked = 0;
2465 
2466 	for (i = 0; i < npages; i++) {
2467 		if (ppa[i]->p_lckcnt == 0)
2468 			unlocked += PAGESIZE;
2469 	}
2470 	return (unlocked);
2471 }
2472 
2473 extern	u_longlong_t randtick(void);
2474 /* number of locks to reserve/skip by spt_lockpages() and spt_unlockpages() */
2475 #define	NLCK	(NCPU_P2)
2476 /* Random number with a range [0, n-1], n must be power of two */
2477 #define	RAND_P2(n)	\
2478 	((((long)curthread >> PTR24_LSB) ^ (long)randtick()) & ((n) - 1))
2479 
2480 int
2481 spt_lockpages(struct seg *seg, pgcnt_t anon_index, pgcnt_t npages,
2482     page_t **ppa, ulong_t *lockmap, size_t pos,
2483     rctl_qty_t *locked)
2484 {
2485 	struct	shm_data *shmd = seg->s_data;
2486 	struct	spt_data *sptd = shmd->shm_sptseg->s_data;
2487 	ulong_t	i;
2488 	int	kernel;
2489 	pgcnt_t	nlck = 0;
2490 	int	rv = 0;
2491 	int	use_reserved = 1;
2492 
2493 	/* return the number of bytes actually locked */
2494 	*locked = 0;
2495 
2496 	/*
2497 	 * To avoid contention on freemem_lock, availrmem and pages_locked
2498 	 * global counters are updated only every nlck locked pages instead of
2499 	 * every time.  Reserve nlck locks up front and deduct from this
2500 	 * reservation for each page that requires a lock.  When the reservation
2501 	 * is consumed, reserve again.  nlck is randomized, so the competing
2502 	 * threads do not fall into a cyclic lock contention pattern. When
2503 	 * memory is low, the lock ahead is disabled, and instead page_pp_lock()
2504 	 * is used to lock pages.
2505 	 */
2506 	for (i = 0; i < npages; anon_index++, pos++, i++) {
2507 		if (nlck == 0 && use_reserved == 1) {
2508 			nlck = NLCK + RAND_P2(NLCK);
2509 			/* if fewer loops left, decrease nlck */
2510 			nlck = MIN(nlck, npages - i);
2511 			/*
2512 			 * Reserve nlck locks up front and deduct from this
2513 			 * reservation for each page that requires a lock.  When
2514 			 * the reservation is consumed, reserve again.
2515 			 */
2516 			mutex_enter(&freemem_lock);
2517 			if ((availrmem - nlck) < pages_pp_maximum) {
2518 				/* Do not do advance memory reserves */
2519 				use_reserved = 0;
2520 			} else {
2521 				availrmem	-= nlck;
2522 				pages_locked	+= nlck;
2523 			}
2524 			mutex_exit(&freemem_lock);
2525 		}
2526 		if (!(shmd->shm_vpage[anon_index] & DISM_PG_LOCKED)) {
2527 			if (sptd->spt_ppa_lckcnt[anon_index] <
2528 			    (ushort_t)DISM_LOCK_MAX) {
2529 				if (++sptd->spt_ppa_lckcnt[anon_index] ==
2530 				    (ushort_t)DISM_LOCK_MAX) {
2531 					cmn_err(CE_WARN,
2532 					    "DISM page lock limit "
2533 					    "reached on DISM offset 0x%lx\n",
2534 					    anon_index << PAGESHIFT);
2535 				}
2536 				kernel = (sptd->spt_ppa &&
2537 				    sptd->spt_ppa[anon_index]);
2538 				if (!page_pp_lock(ppa[i], 0, kernel ||
2539 				    use_reserved)) {
2540 					sptd->spt_ppa_lckcnt[anon_index]--;
2541 					rv = EAGAIN;
2542 					break;
2543 				}
2544 				/* if this is a newly locked page, count it */
2545 				if (ppa[i]->p_lckcnt == 1) {
2546 					if (kernel == 0 && use_reserved == 1)
2547 						nlck--;
2548 					*locked += PAGESIZE;
2549 				}
2550 				shmd->shm_lckpgs++;
2551 				shmd->shm_vpage[anon_index] |= DISM_PG_LOCKED;
2552 				if (lockmap != NULL)
2553 					BT_SET(lockmap, pos);
2554 			}
2555 		}
2556 	}
2557 	/* Return unused lock reservation */
2558 	if (nlck != 0 && use_reserved == 1) {
2559 		mutex_enter(&freemem_lock);
2560 		availrmem	+= nlck;
2561 		pages_locked	-= nlck;
2562 		mutex_exit(&freemem_lock);
2563 	}
2564 
2565 	return (rv);
2566 }
2567 
2568 int
2569 spt_unlockpages(struct seg *seg, pgcnt_t anon_index, pgcnt_t npages,
2570     rctl_qty_t *unlocked)
2571 {
2572 	struct shm_data	*shmd = seg->s_data;
2573 	struct spt_data	*sptd = shmd->shm_sptseg->s_data;
2574 	struct anon_map	*amp = sptd->spt_amp;
2575 	struct anon 	*ap;
2576 	struct vnode 	*vp;
2577 	u_offset_t 	off;
2578 	struct page	*pp;
2579 	int		kernel;
2580 	anon_sync_obj_t	cookie;
2581 	ulong_t		i;
2582 	pgcnt_t		nlck = 0;
2583 	pgcnt_t		nlck_limit = NLCK;
2584 
2585 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2586 	for (i = 0; i < npages; i++, anon_index++) {
2587 		if (shmd->shm_vpage[anon_index] & DISM_PG_LOCKED) {
2588 			anon_array_enter(amp, anon_index, &cookie);
2589 			ap = anon_get_ptr(amp->ahp, anon_index);
2590 			ASSERT(ap);
2591 
2592 			swap_xlate(ap, &vp, &off);
2593 			anon_array_exit(&cookie);
2594 			pp = page_lookup(vp, off, SE_SHARED);
2595 			ASSERT(pp);
2596 			/*
2597 			 * availrmem is decremented only for pages which are not
2598 			 * in seg pcache, for pages in seg pcache availrmem was
2599 			 * decremented in _dismpagelock()
2600 			 */
2601 			kernel = (sptd->spt_ppa && sptd->spt_ppa[anon_index]);
2602 			ASSERT(pp->p_lckcnt > 0);
2603 
2604 			/*
2605 			 * lock page but do not change availrmem, we do it
2606 			 * ourselves every nlck loops.
2607 			 */
2608 			page_pp_unlock(pp, 0, 1);
2609 			if (pp->p_lckcnt == 0) {
2610 				if (kernel == 0)
2611 					nlck++;
2612 				*unlocked += PAGESIZE;
2613 			}
2614 			page_unlock(pp);
2615 			shmd->shm_vpage[anon_index] &= ~DISM_PG_LOCKED;
2616 			sptd->spt_ppa_lckcnt[anon_index]--;
2617 			shmd->shm_lckpgs--;
2618 		}
2619 
2620 		/*
2621 		 * To reduce freemem_lock contention, do not update availrmem
2622 		 * until at least NLCK pages have been unlocked.
2623 		 * 1. No need to update if nlck is zero
2624 		 * 2. Always update if the last iteration
2625 		 */
2626 		if (nlck > 0 && (nlck == nlck_limit || i == npages - 1)) {
2627 			mutex_enter(&freemem_lock);
2628 			availrmem	+= nlck;
2629 			pages_locked	-= nlck;
2630 			mutex_exit(&freemem_lock);
2631 			nlck = 0;
2632 			nlck_limit = NLCK + RAND_P2(NLCK);
2633 		}
2634 	}
2635 	ANON_LOCK_EXIT(&amp->a_rwlock);
2636 
2637 	return (0);
2638 }
2639 
2640 /*ARGSUSED*/
2641 static int
2642 segspt_shmlockop(struct seg *seg, caddr_t addr, size_t len,
2643     int attr, int op, ulong_t *lockmap, size_t pos)
2644 {
2645 	struct shm_data *shmd = seg->s_data;
2646 	struct seg	*sptseg = shmd->shm_sptseg;
2647 	struct spt_data *sptd = sptseg->s_data;
2648 	struct kshmid	*sp = sptd->spt_amp->a_sp;
2649 	pgcnt_t		npages, a_npages;
2650 	page_t		**ppa;
2651 	pgcnt_t 	an_idx, a_an_idx, ppa_idx;
2652 	caddr_t		spt_addr, a_addr;	/* spt and aligned address */
2653 	size_t		a_len;			/* aligned len */
2654 	size_t		share_sz;
2655 	ulong_t		i;
2656 	int		sts = 0;
2657 	rctl_qty_t	unlocked = 0;
2658 	rctl_qty_t	locked = 0;
2659 	struct proc	*p = curproc;
2660 	kproject_t	*proj;
2661 
2662 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2663 	ASSERT(sp != NULL);
2664 
2665 	if ((sptd->spt_flags & SHM_PAGEABLE) == 0) {
2666 		return (0);
2667 	}
2668 
2669 	addr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2670 	an_idx = seg_page(seg, addr);
2671 	npages = btopr(len);
2672 
2673 	if (an_idx + npages > btopr(shmd->shm_amp->size)) {
2674 		return (ENOMEM);
2675 	}
2676 
2677 	/*
2678 	 * A shm's project never changes, so no lock needed.
2679 	 * The shm has a hold on the project, so it will not go away.
2680 	 * Since we have a mapping to shm within this zone, we know
2681 	 * that the zone will not go away.
2682 	 */
2683 	proj = sp->shm_perm.ipc_proj;
2684 
2685 	if (op == MC_LOCK) {
2686 
2687 		/*
2688 		 * Need to align addr and size request if they are not
2689 		 * aligned so we can always allocate large page(s) however
2690 		 * we only lock what was requested in initial request.
2691 		 */
2692 		share_sz = page_get_pagesize(sptseg->s_szc);
2693 		a_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_sz);
2694 		a_len = P2ROUNDUP((uintptr_t)(((addr + len) - a_addr)),
2695 		    share_sz);
2696 		a_npages = btop(a_len);
2697 		a_an_idx = seg_page(seg, a_addr);
2698 		spt_addr = sptseg->s_base + ptob(a_an_idx);
2699 		ppa_idx = an_idx - a_an_idx;
2700 
2701 		if ((ppa = kmem_zalloc(((sizeof (page_t *)) * a_npages),
2702 		    KM_NOSLEEP)) == NULL) {
2703 			return (ENOMEM);
2704 		}
2705 
2706 		/*
2707 		 * Don't cache any new pages for IO and
2708 		 * flush any cached pages.
2709 		 */
2710 		mutex_enter(&sptd->spt_lock);
2711 		if (sptd->spt_ppa != NULL)
2712 			sptd->spt_flags |= DISM_PPA_CHANGED;
2713 
2714 		sts = spt_anon_getpages(sptseg, spt_addr, a_len, ppa);
2715 		if (sts != 0) {
2716 			mutex_exit(&sptd->spt_lock);
2717 			kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2718 			return (sts);
2719 		}
2720 
2721 		mutex_enter(&sp->shm_mlock);
2722 		/* enforce locked memory rctl */
2723 		unlocked = spt_unlockedbytes(npages, &ppa[ppa_idx]);
2724 
2725 		mutex_enter(&p->p_lock);
2726 		if (rctl_incr_locked_mem(p, proj, unlocked, 0)) {
2727 			mutex_exit(&p->p_lock);
2728 			sts = EAGAIN;
2729 		} else {
2730 			mutex_exit(&p->p_lock);
2731 			sts = spt_lockpages(seg, an_idx, npages,
2732 			    &ppa[ppa_idx], lockmap, pos, &locked);
2733 
2734 			/*
2735 			 * correct locked count if not all pages could be
2736 			 * locked
2737 			 */
2738 			if ((unlocked - locked) > 0) {
2739 				rctl_decr_locked_mem(NULL, proj,
2740 				    (unlocked - locked), 0);
2741 			}
2742 		}
2743 		/*
2744 		 * unlock pages
2745 		 */
2746 		for (i = 0; i < a_npages; i++)
2747 			page_unlock(ppa[i]);
2748 		if (sptd->spt_ppa != NULL)
2749 			sptd->spt_flags |= DISM_PPA_CHANGED;
2750 		mutex_exit(&sp->shm_mlock);
2751 		mutex_exit(&sptd->spt_lock);
2752 
2753 		kmem_free(ppa, ((sizeof (page_t *)) * a_npages));
2754 
2755 	} else if (op == MC_UNLOCK) { /* unlock */
2756 		page_t		**ppa;
2757 
2758 		mutex_enter(&sptd->spt_lock);
2759 		if (shmd->shm_lckpgs == 0) {
2760 			mutex_exit(&sptd->spt_lock);
2761 			return (0);
2762 		}
2763 		/*
2764 		 * Don't cache new IO pages.
2765 		 */
2766 		if (sptd->spt_ppa != NULL)
2767 			sptd->spt_flags |= DISM_PPA_CHANGED;
2768 
2769 		mutex_enter(&sp->shm_mlock);
2770 		sts = spt_unlockpages(seg, an_idx, npages, &unlocked);
2771 		if ((ppa = sptd->spt_ppa) != NULL)
2772 			sptd->spt_flags |= DISM_PPA_CHANGED;
2773 		mutex_exit(&sptd->spt_lock);
2774 
2775 		rctl_decr_locked_mem(NULL, proj, unlocked, 0);
2776 		mutex_exit(&sp->shm_mlock);
2777 
2778 		if (ppa != NULL)
2779 			seg_ppurge_wiredpp(ppa);
2780 	}
2781 	return (sts);
2782 }
2783 
2784 /*ARGSUSED*/
2785 int
2786 segspt_shmgetprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
2787 {
2788 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2789 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2790 	spgcnt_t pgno = seg_page(seg, addr+len) - seg_page(seg, addr) + 1;
2791 
2792 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2793 
2794 	/*
2795 	 * ISM segment is always rw.
2796 	 */
2797 	while (--pgno >= 0)
2798 		*protv++ = sptd->spt_prot;
2799 	return (0);
2800 }
2801 
2802 /*ARGSUSED*/
2803 u_offset_t
2804 segspt_shmgetoffset(struct seg *seg, caddr_t addr)
2805 {
2806 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2807 
2808 	/* Offset does not matter in ISM memory */
2809 
2810 	return ((u_offset_t)0);
2811 }
2812 
2813 /* ARGSUSED */
2814 int
2815 segspt_shmgettype(struct seg *seg, caddr_t addr)
2816 {
2817 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2818 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2819 
2820 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2821 
2822 	/*
2823 	 * The shared memory mapping is always MAP_SHARED, SWAP is only
2824 	 * reserved for DISM
2825 	 */
2826 	return (MAP_SHARED |
2827 	    ((sptd->spt_flags & SHM_PAGEABLE) ? 0 : MAP_NORESERVE));
2828 }
2829 
2830 /*ARGSUSED*/
2831 int
2832 segspt_shmgetvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
2833 {
2834 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
2835 	struct spt_data *sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2836 
2837 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2838 
2839 	*vpp = sptd->spt_vp;
2840 	return (0);
2841 }
2842 
2843 /*
2844  * We need to wait for pending IO to complete to a DISM segment in order for
2845  * pages to get kicked out of the seg_pcache.  120 seconds should be more
2846  * than enough time to wait.
2847  */
2848 static clock_t spt_pcache_wait = 120;
2849 
2850 /*ARGSUSED*/
2851 static int
2852 segspt_shmadvise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
2853 {
2854 	struct shm_data	*shmd = (struct shm_data *)seg->s_data;
2855 	struct spt_data	*sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2856 	struct anon_map	*amp;
2857 	pgcnt_t pg_idx;
2858 	ushort_t gen;
2859 	clock_t	end_lbolt;
2860 	int writer;
2861 	page_t **ppa;
2862 
2863 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as));
2864 
2865 	if (behav == MADV_FREE || behav == MADV_PURGE) {
2866 		if ((sptd->spt_flags & SHM_PAGEABLE) == 0)
2867 			return (0);
2868 
2869 		amp = sptd->spt_amp;
2870 		pg_idx = seg_page(seg, addr);
2871 
2872 		mutex_enter(&sptd->spt_lock);
2873 		if ((ppa = sptd->spt_ppa) == NULL) {
2874 			mutex_exit(&sptd->spt_lock);
2875 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2876 			(void) anon_disclaim(amp, pg_idx, len, behav, NULL);
2877 			ANON_LOCK_EXIT(&amp->a_rwlock);
2878 			return (0);
2879 		}
2880 
2881 		sptd->spt_flags |= DISM_PPA_CHANGED;
2882 		gen = sptd->spt_gen;
2883 
2884 		mutex_exit(&sptd->spt_lock);
2885 
2886 		/*
2887 		 * Purge all DISM cached pages
2888 		 */
2889 		seg_ppurge_wiredpp(ppa);
2890 
2891 		/*
2892 		 * Drop the AS_LOCK so that other threads can grab it
2893 		 * in the as_pageunlock path and hopefully get the segment
2894 		 * kicked out of the seg_pcache.  We bump the shm_softlockcnt
2895 		 * to keep this segment resident.
2896 		 */
2897 		writer = AS_WRITE_HELD(seg->s_as);
2898 		atomic_inc_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
2899 		AS_LOCK_EXIT(seg->s_as);
2900 
2901 		mutex_enter(&sptd->spt_lock);
2902 
2903 		end_lbolt = ddi_get_lbolt() + (hz * spt_pcache_wait);
2904 
2905 		/*
2906 		 * Try to wait for pages to get kicked out of the seg_pcache.
2907 		 */
2908 		while (sptd->spt_gen == gen &&
2909 		    (sptd->spt_flags & DISM_PPA_CHANGED) &&
2910 		    ddi_get_lbolt() < end_lbolt) {
2911 			if (!cv_timedwait_sig(&sptd->spt_cv,
2912 			    &sptd->spt_lock, end_lbolt)) {
2913 				break;
2914 			}
2915 		}
2916 
2917 		mutex_exit(&sptd->spt_lock);
2918 
2919 		/* Regrab the AS_LOCK and release our hold on the segment */
2920 		AS_LOCK_ENTER(seg->s_as, writer ? RW_WRITER : RW_READER);
2921 		atomic_dec_ulong((ulong_t *)(&(shmd->shm_softlockcnt)));
2922 		if (shmd->shm_softlockcnt <= 0) {
2923 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2924 				mutex_enter(&seg->s_as->a_contents);
2925 				if (AS_ISUNMAPWAIT(seg->s_as)) {
2926 					AS_CLRUNMAPWAIT(seg->s_as);
2927 					cv_broadcast(&seg->s_as->a_cv);
2928 				}
2929 				mutex_exit(&seg->s_as->a_contents);
2930 			}
2931 		}
2932 
2933 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2934 		(void) anon_disclaim(amp, pg_idx, len, behav, NULL);
2935 		ANON_LOCK_EXIT(&amp->a_rwlock);
2936 	} else if (lgrp_optimizations() && (behav == MADV_ACCESS_LWP ||
2937 	    behav == MADV_ACCESS_MANY || behav == MADV_ACCESS_DEFAULT)) {
2938 		int			already_set;
2939 		ulong_t			anon_index;
2940 		lgrp_mem_policy_t	policy;
2941 		caddr_t			shm_addr;
2942 		size_t			share_size;
2943 		size_t			size;
2944 		struct seg		*sptseg = shmd->shm_sptseg;
2945 		caddr_t			sptseg_addr;
2946 
2947 		/*
2948 		 * Align address and length to page size of underlying segment
2949 		 */
2950 		share_size = page_get_pagesize(shmd->shm_sptseg->s_szc);
2951 		shm_addr = (caddr_t)P2ALIGN((uintptr_t)(addr), share_size);
2952 		size = P2ROUNDUP((uintptr_t)(((addr + len) - shm_addr)),
2953 		    share_size);
2954 
2955 		amp = shmd->shm_amp;
2956 		anon_index = seg_page(seg, shm_addr);
2957 
2958 		/*
2959 		 * And now we may have to adjust size downward if we have
2960 		 * exceeded the realsize of the segment or initial anon
2961 		 * allocations.
2962 		 */
2963 		sptseg_addr = sptseg->s_base + ptob(anon_index);
2964 		if ((sptseg_addr + size) >
2965 		    (sptseg->s_base + sptd->spt_realsize))
2966 			size = (sptseg->s_base + sptd->spt_realsize) -
2967 			    sptseg_addr;
2968 
2969 		/*
2970 		 * Set memory allocation policy for this segment
2971 		 */
2972 		policy = lgrp_madv_to_policy(behav, len, MAP_SHARED);
2973 		already_set = lgrp_shm_policy_set(policy, amp, anon_index,
2974 		    NULL, 0, len);
2975 
2976 		/*
2977 		 * If random memory allocation policy set already,
2978 		 * don't bother reapplying it.
2979 		 */
2980 		if (already_set && !LGRP_MEM_POLICY_REAPPLICABLE(policy))
2981 			return (0);
2982 
2983 		/*
2984 		 * Mark any existing pages in the given range for
2985 		 * migration, flushing the I/O page cache, and using
2986 		 * underlying segment to calculate anon index and get
2987 		 * anonmap and vnode pointer from
2988 		 */
2989 		if (shmd->shm_softlockcnt > 0)
2990 			segspt_purge(seg);
2991 
2992 		page_mark_migrate(seg, shm_addr, size, amp, 0, NULL, 0, 0);
2993 	}
2994 
2995 	return (0);
2996 }
2997 
2998 /*ARGSUSED*/
2999 void
3000 segspt_shmdump(struct seg *seg)
3001 {
3002 	/* no-op for ISM segment */
3003 }
3004 
3005 /*ARGSUSED*/
3006 static faultcode_t
3007 segspt_shmsetpgsz(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
3008 {
3009 	return (ENOTSUP);
3010 }
3011 
3012 /*
3013  * get a memory ID for an addr in a given segment
3014  */
3015 static int
3016 segspt_shmgetmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
3017 {
3018 	struct shm_data *shmd = (struct shm_data *)seg->s_data;
3019 	struct anon 	*ap;
3020 	size_t		anon_index;
3021 	struct anon_map	*amp = shmd->shm_amp;
3022 	struct spt_data	*sptd = shmd->shm_sptseg->s_data;
3023 	struct seg	*sptseg = shmd->shm_sptseg;
3024 	anon_sync_obj_t	cookie;
3025 
3026 	anon_index = seg_page(seg, addr);
3027 
3028 	if (addr > (seg->s_base + sptd->spt_realsize)) {
3029 		return (EFAULT);
3030 	}
3031 
3032 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
3033 	anon_array_enter(amp, anon_index, &cookie);
3034 	ap = anon_get_ptr(amp->ahp, anon_index);
3035 	if (ap == NULL) {
3036 		struct page *pp;
3037 		caddr_t spt_addr = sptseg->s_base + ptob(anon_index);
3038 
3039 		pp = anon_zero(sptseg, spt_addr, &ap, kcred);
3040 		if (pp == NULL) {
3041 			anon_array_exit(&cookie);
3042 			ANON_LOCK_EXIT(&amp->a_rwlock);
3043 			return (ENOMEM);
3044 		}
3045 		(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
3046 		page_unlock(pp);
3047 	}
3048 	anon_array_exit(&cookie);
3049 	ANON_LOCK_EXIT(&amp->a_rwlock);
3050 	memidp->val[0] = (uintptr_t)ap;
3051 	memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
3052 	return (0);
3053 }
3054 
3055 /*
3056  * Get memory allocation policy info for specified address in given segment
3057  */
3058 static lgrp_mem_policy_info_t *
3059 segspt_shmgetpolicy(struct seg *seg, caddr_t addr)
3060 {
3061 	struct anon_map		*amp;
3062 	ulong_t			anon_index;
3063 	lgrp_mem_policy_info_t	*policy_info;
3064 	struct shm_data		*shm_data;
3065 
3066 	ASSERT(seg != NULL);
3067 
3068 	/*
3069 	 * Get anon_map from segshm
3070 	 *
3071 	 * Assume that no lock needs to be held on anon_map, since
3072 	 * it should be protected by its reference count which must be
3073 	 * nonzero for an existing segment
3074 	 * Need to grab readers lock on policy tree though
3075 	 */
3076 	shm_data = (struct shm_data *)seg->s_data;
3077 	if (shm_data == NULL)
3078 		return (NULL);
3079 	amp = shm_data->shm_amp;
3080 	ASSERT(amp->refcnt != 0);
3081 
3082 	/*
3083 	 * Get policy info
3084 	 *
3085 	 * Assume starting anon index of 0
3086 	 */
3087 	anon_index = seg_page(seg, addr);
3088 	policy_info = lgrp_shm_policy_get(amp, anon_index, NULL, 0);
3089 
3090 	return (policy_info);
3091 }
3092 
3093 /*ARGSUSED*/
3094 static int
3095 segspt_shmcapable(struct seg *seg, segcapability_t capability)
3096 {
3097 	return (0);
3098 }
3099