xref: /titanic_41/usr/src/uts/common/vm/vm_as.c (revision 4aac33d31b41cc7e3ac6fb66747ff2cae63d08cf)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 #pragma ident	"%Z%%M%	%I%	%E% SMI"
40 
41 /*
42  * VM - address spaces.
43  */
44 
45 #include <sys/types.h>
46 #include <sys/t_lock.h>
47 #include <sys/param.h>
48 #include <sys/errno.h>
49 #include <sys/systm.h>
50 #include <sys/mman.h>
51 #include <sys/sysmacros.h>
52 #include <sys/cpuvar.h>
53 #include <sys/sysinfo.h>
54 #include <sys/kmem.h>
55 #include <sys/vnode.h>
56 #include <sys/vmsystm.h>
57 #include <sys/cmn_err.h>
58 #include <sys/debug.h>
59 #include <sys/tnf_probe.h>
60 #include <sys/vtrace.h>
61 
62 #include <vm/hat.h>
63 #include <vm/xhat.h>
64 #include <vm/as.h>
65 #include <vm/seg.h>
66 #include <vm/seg_vn.h>
67 #include <vm/seg_dev.h>
68 #include <vm/seg_kmem.h>
69 #include <vm/seg_map.h>
70 #include <vm/seg_spt.h>
71 #include <vm/page.h>
72 
73 clock_t deadlk_wait = 1; /* number of ticks to wait before retrying */
74 
75 static struct kmem_cache *as_cache;
76 
77 static void as_setwatchprot(struct as *, caddr_t, size_t, uint_t);
78 static void as_clearwatchprot(struct as *, caddr_t, size_t);
79 int as_map_locked(struct as *, caddr_t, size_t, int ((*)()), void *);
80 
81 
82 /*
83  * Verifying the segment lists is very time-consuming; it may not be
84  * desirable always to define VERIFY_SEGLIST when DEBUG is set.
85  */
86 #ifdef DEBUG
87 #define	VERIFY_SEGLIST
88 int do_as_verify = 0;
89 #endif
90 
91 /*
92  * Allocate a new callback data structure entry and fill in the events of
93  * interest, the address range of interest, and the callback argument.
94  * Link the entry on the as->a_callbacks list. A callback entry for the
95  * entire address space may be specified with vaddr = 0 and size = -1.
96  *
97  * CALLERS RESPONSIBILITY: If not calling from within the process context for
98  * the specified as, the caller must guarantee persistence of the specified as
99  * for the duration of this function (eg. pages being locked within the as
100  * will guarantee persistence).
101  */
102 int
103 as_add_callback(struct as *as, void (*cb_func)(), void *arg, uint_t events,
104 		caddr_t vaddr, size_t size, int sleepflag)
105 {
106 	struct as_callback 	*current_head, *cb;
107 	caddr_t 		saddr;
108 	size_t 			rsize;
109 
110 	/* callback function and an event are mandatory */
111 	if ((cb_func == NULL) || ((events & AS_ALL_EVENT) == 0))
112 		return (EINVAL);
113 
114 	/* Adding a callback after as_free has been called is not allowed */
115 	if (as == &kas)
116 		return (ENOMEM);
117 
118 	/*
119 	 * vaddr = 0 and size = -1 is used to indicate that the callback range
120 	 * is the entire address space so no rounding is done in that case.
121 	 */
122 	if (size != -1) {
123 		saddr = (caddr_t)((uintptr_t)vaddr & (uintptr_t)PAGEMASK);
124 		rsize = (((size_t)(vaddr + size) + PAGEOFFSET) & PAGEMASK) -
125 			(size_t)saddr;
126 		/* check for wraparound */
127 		if (saddr + rsize < saddr)
128 			return (ENOMEM);
129 	} else {
130 		if (vaddr != 0)
131 			return (EINVAL);
132 		saddr = vaddr;
133 		rsize = size;
134 	}
135 
136 	/* Allocate and initialize a callback entry */
137 	cb = kmem_zalloc(sizeof (struct as_callback), sleepflag);
138 	if (cb == NULL)
139 		return (EAGAIN);
140 
141 	cb->ascb_func = cb_func;
142 	cb->ascb_arg = arg;
143 	cb->ascb_events = events;
144 	cb->ascb_saddr = saddr;
145 	cb->ascb_len = rsize;
146 
147 	/* Add the entry to the list */
148 	mutex_enter(&as->a_contents);
149 	current_head = as->a_callbacks;
150 	as->a_callbacks = cb;
151 	cb->ascb_next = current_head;
152 
153 	/*
154 	 * The call to this function may lose in a race with
155 	 * a pertinent event - eg. a thread does long term memory locking
156 	 * but before the callback is added another thread executes as_unmap.
157 	 * A broadcast here resolves that.
158 	 */
159 	if ((cb->ascb_events & AS_UNMAPWAIT_EVENT) && AS_ISUNMAPWAIT(as)) {
160 		AS_CLRUNMAPWAIT(as);
161 		cv_broadcast(&as->a_cv);
162 	}
163 
164 	mutex_exit(&as->a_contents);
165 	return (0);
166 }
167 
168 /*
169  * Search the callback list for an entry which pertains to arg.
170  *
171  * This is called from within the client upon completion of the callback.
172  * RETURN VALUES:
173  *	AS_CALLBACK_DELETED  (callback entry found and deleted)
174  *	AS_CALLBACK_NOTFOUND (no callback entry found - this is ok)
175  *	AS_CALLBACK_DELETE_DEFERRED (callback is in process, delete of this
176  *			entry will be made in as_do_callbacks)
177  *
178  * If as_delete_callback encounters a matching entry with AS_CALLBACK_CALLED
179  * set, it indicates that as_do_callbacks is processing this entry.  The
180  * AS_ALL_EVENT events are cleared in the entry, and a broadcast is made
181  * to unblock as_do_callbacks, in case it is blocked.
182  *
183  * CALLERS RESPONSIBILITY: If not calling from within the process context for
184  * the specified as, the caller must guarantee persistence of the specified as
185  * for the duration of this function (eg. pages being locked within the as
186  * will guarantee persistence).
187  */
188 uint_t
189 as_delete_callback(struct as *as, void *arg)
190 {
191 	struct as_callback **prevcb = &as->a_callbacks;
192 	struct as_callback *cb;
193 	uint_t rc = AS_CALLBACK_NOTFOUND;
194 
195 	mutex_enter(&as->a_contents);
196 	for (cb = as->a_callbacks; cb; prevcb = &cb->ascb_next, cb = *prevcb) {
197 		if (cb->ascb_arg != arg)
198 			continue;
199 
200 		/*
201 		 * If the events indicate AS_CALLBACK_CALLED, just clear
202 		 * AS_ALL_EVENT in the events field and wakeup the thread
203 		 * that may be waiting in as_do_callbacks.  as_do_callbacks
204 		 * will take care of removing this entry from the list.  In
205 		 * that case, return AS_CALLBACK_DELETE_DEFERRED.  Otherwise
206 		 * (AS_CALLBACK_CALLED not set), just remove it from the
207 		 * list, return the memory and return AS_CALLBACK_DELETED.
208 		 */
209 		if ((cb->ascb_events & AS_CALLBACK_CALLED) != 0) {
210 			/* leave AS_CALLBACK_CALLED */
211 			cb->ascb_events &= ~AS_ALL_EVENT;
212 			rc = AS_CALLBACK_DELETE_DEFERRED;
213 			cv_broadcast(&as->a_cv);
214 		} else {
215 			*prevcb = cb->ascb_next;
216 			kmem_free(cb, sizeof (struct as_callback));
217 			rc = AS_CALLBACK_DELETED;
218 		}
219 		break;
220 	}
221 	mutex_exit(&as->a_contents);
222 	return (rc);
223 }
224 
225 /*
226  * Searches the as callback list for a matching entry.
227  * Returns a pointer to the first matching callback, or NULL if
228  * nothing is found.
229  * This function never sleeps so it is ok to call it with more
230  * locks held but the (required) a_contents mutex.
231  *
232  * See also comment on as_do_callbacks below.
233  */
234 static struct as_callback *
235 as_find_callback(struct as *as, uint_t events, caddr_t event_addr,
236 			size_t event_len)
237 {
238 	struct as_callback	*cb;
239 
240 	ASSERT(MUTEX_HELD(&as->a_contents));
241 	for (cb = as->a_callbacks; cb != NULL; cb = cb->ascb_next) {
242 		/*
243 		 * If the callback has not already been called, then
244 		 * check if events or address range pertains.  An event_len
245 		 * of zero means do an unconditional callback.
246 		 */
247 		if (((cb->ascb_events & AS_CALLBACK_CALLED) != 0) ||
248 		    ((event_len != 0) && (((cb->ascb_events & events) == 0) ||
249 		    (event_addr + event_len < cb->ascb_saddr) ||
250 		    (event_addr > (cb->ascb_saddr + cb->ascb_len))))) {
251 			continue;
252 		}
253 		break;
254 	}
255 	return (cb);
256 }
257 
258 /*
259  * Executes a given callback and removes it from the callback list for
260  * this address space.
261  * This function may sleep so the caller must drop all locks except
262  * a_contents before calling this func.
263  *
264  * See also comments on as_do_callbacks below.
265  */
266 static void
267 as_execute_callback(struct as *as, struct as_callback *cb,
268 				uint_t events)
269 {
270 	struct as_callback **prevcb;
271 	void	*cb_arg;
272 
273 	ASSERT(MUTEX_HELD(&as->a_contents) && (cb->ascb_events & events));
274 	cb->ascb_events |= AS_CALLBACK_CALLED;
275 	mutex_exit(&as->a_contents);
276 	(*cb->ascb_func)(as, cb->ascb_arg, events);
277 	mutex_enter(&as->a_contents);
278 	/*
279 	 * the callback function is required to delete the callback
280 	 * when the callback function determines it is OK for
281 	 * this thread to continue. as_delete_callback will clear
282 	 * the AS_ALL_EVENT in the events field when it is deleted.
283 	 * If the callback function called as_delete_callback,
284 	 * events will already be cleared and there will be no blocking.
285 	 */
286 	while ((cb->ascb_events & events) != 0) {
287 		cv_wait(&as->a_cv, &as->a_contents);
288 	}
289 	/*
290 	 * This entry needs to be taken off the list. Normally, the
291 	 * callback func itself does that, but unfortunately the list
292 	 * may have changed while the callback was running because the
293 	 * a_contents mutex was dropped and someone else other than the
294 	 * callback func itself could have called as_delete_callback,
295 	 * so we have to search to find this entry again.  The entry
296 	 * must have AS_CALLBACK_CALLED, and have the same 'arg'.
297 	 */
298 	cb_arg = cb->ascb_arg;
299 	prevcb = &as->a_callbacks;
300 	for (cb = as->a_callbacks; cb != NULL;
301 	    prevcb = &cb->ascb_next, cb = *prevcb) {
302 		if (((cb->ascb_events & AS_CALLBACK_CALLED) == 0) ||
303 		    (cb_arg != cb->ascb_arg)) {
304 			continue;
305 		}
306 		*prevcb = cb->ascb_next;
307 		kmem_free(cb, sizeof (struct as_callback));
308 		break;
309 	}
310 }
311 
312 /*
313  * Check the callback list for a matching event and intersection of
314  * address range. If there is a match invoke the callback.  Skip an entry if:
315  *    - a callback is already in progress for this entry (AS_CALLBACK_CALLED)
316  *    - not event of interest
317  *    - not address range of interest
318  *
319  * An event_len of zero indicates a request for an unconditional callback
320  * (regardless of event), only the AS_CALLBACK_CALLED is checked.  The
321  * a_contents lock must be dropped before a callback, so only one callback
322  * can be done before returning. Return -1 (true) if a callback was
323  * executed and removed from the list, else return 0 (false).
324  *
325  * The logically separate parts, i.e. finding a matching callback and
326  * executing a given callback have been separated into two functions
327  * so that they can be called with different sets of locks held beyond
328  * the always-required a_contents. as_find_callback does not sleep so
329  * it is ok to call it if more locks than a_contents (i.e. the a_lock
330  * rwlock) are held. as_execute_callback on the other hand may sleep
331  * so all locks beyond a_contents must be dropped by the caller if one
332  * does not want to end comatose.
333  */
334 static int
335 as_do_callbacks(struct as *as, uint_t events, caddr_t event_addr,
336 			size_t event_len)
337 {
338 	struct as_callback *cb;
339 
340 	if ((cb = as_find_callback(as, events, event_addr, event_len))) {
341 		as_execute_callback(as, cb, events);
342 		return (-1);
343 	}
344 	return (0);
345 }
346 
347 /*
348  * Search for the segment containing addr. If a segment containing addr
349  * exists, that segment is returned.  If no such segment exists, and
350  * the list spans addresses greater than addr, then the first segment
351  * whose base is greater than addr is returned; otherwise, NULL is
352  * returned unless tail is true, in which case the last element of the
353  * list is returned.
354  *
355  * a_seglast is used to cache the last found segment for repeated
356  * searches to the same addr (which happens frequently).
357  */
358 struct seg *
359 as_findseg(struct as *as, caddr_t addr, int tail)
360 {
361 	struct seg *seg = as->a_seglast;
362 	avl_index_t where;
363 
364 	ASSERT(AS_LOCK_HELD(as, &as->a_lock));
365 
366 	if (seg != NULL &&
367 	    seg->s_base <= addr &&
368 	    addr < seg->s_base + seg->s_size)
369 		return (seg);
370 
371 	seg = avl_find(&as->a_segtree, &addr, &where);
372 	if (seg != NULL)
373 		return (as->a_seglast = seg);
374 
375 	seg = avl_nearest(&as->a_segtree, where, AVL_AFTER);
376 	if (seg == NULL && tail)
377 		seg = avl_last(&as->a_segtree);
378 	return (as->a_seglast = seg);
379 }
380 
381 #ifdef VERIFY_SEGLIST
382 /*
383  * verify that the linked list is coherent
384  */
385 static void
386 as_verify(struct as *as)
387 {
388 	struct seg *seg, *seglast, *p, *n;
389 	uint_t nsegs = 0;
390 
391 	if (do_as_verify == 0)
392 		return;
393 
394 	seglast = as->a_seglast;
395 
396 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
397 		ASSERT(seg->s_as == as);
398 		p = AS_SEGPREV(as, seg);
399 		n = AS_SEGNEXT(as, seg);
400 		ASSERT(p == NULL || p->s_as == as);
401 		ASSERT(p == NULL || p->s_base < seg->s_base);
402 		ASSERT(n == NULL || n->s_base > seg->s_base);
403 		ASSERT(n != NULL || seg == avl_last(&as->a_segtree));
404 		if (seg == seglast)
405 			seglast = NULL;
406 		nsegs++;
407 	}
408 	ASSERT(seglast == NULL);
409 	ASSERT(avl_numnodes(&as->a_segtree) == nsegs);
410 }
411 #endif /* VERIFY_SEGLIST */
412 
413 /*
414  * Add a new segment to the address space. The avl_find()
415  * may be expensive so we attempt to use last segment accessed
416  * in as_gap() as an insertion point.
417  */
418 int
419 as_addseg(struct as  *as, struct seg *newseg)
420 {
421 	struct seg *seg;
422 	caddr_t addr;
423 	caddr_t eaddr;
424 	avl_index_t where;
425 
426 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
427 
428 	as->a_updatedir = 1;	/* inform /proc */
429 	gethrestime(&as->a_updatetime);
430 
431 	if (as->a_lastgaphl != NULL) {
432 		struct seg *hseg = NULL;
433 		struct seg *lseg = NULL;
434 
435 		if (as->a_lastgaphl->s_base > newseg->s_base) {
436 			hseg = as->a_lastgaphl;
437 			lseg = AVL_PREV(&as->a_segtree, hseg);
438 		} else {
439 			lseg = as->a_lastgaphl;
440 			hseg = AVL_NEXT(&as->a_segtree, lseg);
441 		}
442 
443 		if (hseg && lseg && lseg->s_base < newseg->s_base &&
444 		    hseg->s_base > newseg->s_base) {
445 			avl_insert_here(&as->a_segtree, newseg, lseg,
446 			    AVL_AFTER);
447 			as->a_lastgaphl = NULL;
448 			as->a_seglast = newseg;
449 			return (0);
450 		}
451 		as->a_lastgaphl = NULL;
452 	}
453 
454 	addr = newseg->s_base;
455 	eaddr = addr + newseg->s_size;
456 again:
457 
458 	seg = avl_find(&as->a_segtree, &addr, &where);
459 
460 	if (seg == NULL)
461 		seg = avl_nearest(&as->a_segtree, where, AVL_AFTER);
462 
463 	if (seg == NULL)
464 		seg = avl_last(&as->a_segtree);
465 
466 	if (seg != NULL) {
467 		caddr_t base = seg->s_base;
468 
469 		/*
470 		 * If top of seg is below the requested address, then
471 		 * the insertion point is at the end of the linked list,
472 		 * and seg points to the tail of the list.  Otherwise,
473 		 * the insertion point is immediately before seg.
474 		 */
475 		if (base + seg->s_size > addr) {
476 			if (addr >= base || eaddr > base) {
477 #ifdef __sparc
478 				extern struct seg_ops segnf_ops;
479 
480 				/*
481 				 * no-fault segs must disappear if overlaid.
482 				 * XXX need new segment type so
483 				 * we don't have to check s_ops
484 				 */
485 				if (seg->s_ops == &segnf_ops) {
486 					seg_unmap(seg);
487 					goto again;
488 				}
489 #endif
490 				return (-1);	/* overlapping segment */
491 			}
492 		}
493 	}
494 	as->a_seglast = newseg;
495 	avl_insert(&as->a_segtree, newseg, where);
496 
497 #ifdef VERIFY_SEGLIST
498 	as_verify(as);
499 #endif
500 	return (0);
501 }
502 
503 struct seg *
504 as_removeseg(struct as *as, struct seg *seg)
505 {
506 	avl_tree_t *t;
507 
508 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
509 
510 	as->a_updatedir = 1;	/* inform /proc */
511 	gethrestime(&as->a_updatetime);
512 
513 	if (seg == NULL)
514 		return (NULL);
515 
516 	t = &as->a_segtree;
517 	if (as->a_seglast == seg)
518 		as->a_seglast = NULL;
519 	as->a_lastgaphl = NULL;
520 
521 	/*
522 	 * if this segment is at an address higher than
523 	 * a_lastgap, set a_lastgap to the next segment (NULL if last segment)
524 	 */
525 	if (as->a_lastgap &&
526 	    (seg == as->a_lastgap || seg->s_base > as->a_lastgap->s_base))
527 		as->a_lastgap = AVL_NEXT(t, seg);
528 
529 	/*
530 	 * remove the segment from the seg tree
531 	 */
532 	avl_remove(t, seg);
533 
534 #ifdef VERIFY_SEGLIST
535 	as_verify(as);
536 #endif
537 	return (seg);
538 }
539 
540 /*
541  * Find a segment containing addr.
542  */
543 struct seg *
544 as_segat(struct as *as, caddr_t addr)
545 {
546 	struct seg *seg = as->a_seglast;
547 
548 	ASSERT(AS_LOCK_HELD(as, &as->a_lock));
549 
550 	if (seg != NULL && seg->s_base <= addr &&
551 	    addr < seg->s_base + seg->s_size)
552 		return (seg);
553 
554 	seg = avl_find(&as->a_segtree, &addr, NULL);
555 	return (seg);
556 }
557 
558 /*
559  * Serialize all searches for holes in an address space to
560  * prevent two or more threads from allocating the same virtual
561  * address range.  The address space must not be "read/write"
562  * locked by the caller since we may block.
563  */
564 void
565 as_rangelock(struct as *as)
566 {
567 	mutex_enter(&as->a_contents);
568 	while (AS_ISCLAIMGAP(as))
569 		cv_wait(&as->a_cv, &as->a_contents);
570 	AS_SETCLAIMGAP(as);
571 	mutex_exit(&as->a_contents);
572 }
573 
574 /*
575  * Release hold on a_state & AS_CLAIMGAP and signal any other blocked threads.
576  */
577 void
578 as_rangeunlock(struct as *as)
579 {
580 	mutex_enter(&as->a_contents);
581 	AS_CLRCLAIMGAP(as);
582 	cv_signal(&as->a_cv);
583 	mutex_exit(&as->a_contents);
584 }
585 
586 /*
587  * compar segments (or just an address) by segment address range
588  */
589 static int
590 as_segcompar(const void *x, const void *y)
591 {
592 	struct seg *a = (struct seg *)x;
593 	struct seg *b = (struct seg *)y;
594 
595 	if (a->s_base < b->s_base)
596 		return (-1);
597 	if (a->s_base >= b->s_base + b->s_size)
598 		return (1);
599 	return (0);
600 }
601 
602 
603 void
604 as_avlinit(struct as *as)
605 {
606 	avl_create(&as->a_segtree, as_segcompar, sizeof (struct seg),
607 	    offsetof(struct seg, s_tree));
608 	avl_create(&as->a_wpage, wp_compare, sizeof (struct watched_page),
609 	    offsetof(struct watched_page, wp_link));
610 }
611 
612 /*ARGSUSED*/
613 static int
614 as_constructor(void *buf, void *cdrarg, int kmflags)
615 {
616 	struct as *as = buf;
617 
618 	mutex_init(&as->a_contents, NULL, MUTEX_DEFAULT, NULL);
619 	cv_init(&as->a_cv, NULL, CV_DEFAULT, NULL);
620 	rw_init(&as->a_lock, NULL, RW_DEFAULT, NULL);
621 	as_avlinit(as);
622 	return (0);
623 }
624 
625 /*ARGSUSED1*/
626 static void
627 as_destructor(void *buf, void *cdrarg)
628 {
629 	struct as *as = buf;
630 
631 	avl_destroy(&as->a_segtree);
632 	mutex_destroy(&as->a_contents);
633 	cv_destroy(&as->a_cv);
634 	rw_destroy(&as->a_lock);
635 }
636 
637 void
638 as_init(void)
639 {
640 	as_cache = kmem_cache_create("as_cache", sizeof (struct as), 0,
641 		as_constructor, as_destructor, NULL, NULL, NULL, 0);
642 }
643 
644 /*
645  * Allocate and initialize an address space data structure.
646  * We call hat_alloc to allow any machine dependent
647  * information in the hat structure to be initialized.
648  */
649 struct as *
650 as_alloc(void)
651 {
652 	struct as *as;
653 
654 	as = kmem_cache_alloc(as_cache, KM_SLEEP);
655 
656 	as->a_flags		= 0;
657 	as->a_vbits		= 0;
658 	as->a_hrm		= NULL;
659 	as->a_seglast		= NULL;
660 	as->a_size		= 0;
661 	as->a_updatedir		= 0;
662 	gethrestime(&as->a_updatetime);
663 	as->a_objectdir		= NULL;
664 	as->a_sizedir		= 0;
665 	as->a_userlimit		= (caddr_t)USERLIMIT;
666 	as->a_lastgap		= NULL;
667 	as->a_lastgaphl		= NULL;
668 	as->a_callbacks		= NULL;
669 
670 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
671 	as->a_hat = hat_alloc(as);	/* create hat for default system mmu */
672 	AS_LOCK_EXIT(as, &as->a_lock);
673 
674 	as->a_xhat = NULL;
675 
676 	return (as);
677 }
678 
679 /*
680  * Free an address space data structure.
681  * Need to free the hat first and then
682  * all the segments on this as and finally
683  * the space for the as struct itself.
684  */
685 void
686 as_free(struct as *as)
687 {
688 	struct hat *hat = as->a_hat;
689 	struct seg *seg, *next;
690 	int called = 0;
691 
692 top:
693 	/*
694 	 * Invoke ALL callbacks. as_do_callbacks will do one callback
695 	 * per call, and not return (-1) until the callback has completed.
696 	 * When as_do_callbacks returns zero, all callbacks have completed.
697 	 */
698 	mutex_enter(&as->a_contents);
699 	while (as->a_callbacks && as_do_callbacks(as, AS_ALL_EVENT, 0, 0));
700 
701 	/* This will prevent new XHATs from attaching to as */
702 	if (!called)
703 		AS_SETBUSY(as);
704 	mutex_exit(&as->a_contents);
705 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
706 
707 	if (!called) {
708 		called = 1;
709 		hat_free_start(hat);
710 		if (as->a_xhat != NULL)
711 			xhat_free_start_all(as);
712 	}
713 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = next) {
714 		int err;
715 
716 		next = AS_SEGNEXT(as, seg);
717 		err = SEGOP_UNMAP(seg, seg->s_base, seg->s_size);
718 		if (err == EAGAIN) {
719 			mutex_enter(&as->a_contents);
720 			if (as->a_callbacks) {
721 				AS_LOCK_EXIT(as, &as->a_lock);
722 			} else {
723 				/*
724 				 * Memory is currently locked. Wait for a
725 				 * cv_signal that it has been unlocked, then
726 				 * try the operation again.
727 				 */
728 				if (AS_ISUNMAPWAIT(as) == 0)
729 					cv_broadcast(&as->a_cv);
730 				AS_SETUNMAPWAIT(as);
731 				AS_LOCK_EXIT(as, &as->a_lock);
732 				while (AS_ISUNMAPWAIT(as))
733 					cv_wait(&as->a_cv, &as->a_contents);
734 			}
735 			mutex_exit(&as->a_contents);
736 			goto top;
737 		} else {
738 			/*
739 			 * We do not expect any other error return at this
740 			 * time. This is similar to an ASSERT in seg_unmap()
741 			 */
742 			ASSERT(err == 0);
743 		}
744 	}
745 	hat_free_end(hat);
746 	if (as->a_xhat != NULL)
747 		xhat_free_end_all(as);
748 	AS_LOCK_EXIT(as, &as->a_lock);
749 
750 	/* /proc stuff */
751 	ASSERT(avl_numnodes(&as->a_wpage) == 0);
752 	if (as->a_objectdir) {
753 		kmem_free(as->a_objectdir, as->a_sizedir * sizeof (vnode_t *));
754 		as->a_objectdir = NULL;
755 		as->a_sizedir = 0;
756 	}
757 
758 	/*
759 	 * Free the struct as back to kmem.  Assert it has no segments.
760 	 */
761 	ASSERT(avl_numnodes(&as->a_segtree) == 0);
762 	kmem_cache_free(as_cache, as);
763 }
764 
765 int
766 as_dup(struct as *as, struct as **outas)
767 {
768 	struct as *newas;
769 	struct seg *seg, *newseg;
770 	int error;
771 
772 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
773 	as_clearwatch(as);
774 	newas = as_alloc();
775 	newas->a_userlimit = as->a_userlimit;
776 	AS_LOCK_ENTER(newas, &newas->a_lock, RW_WRITER);
777 
778 	/* This will prevent new XHATs from attaching */
779 	mutex_enter(&as->a_contents);
780 	AS_SETBUSY(as);
781 	mutex_exit(&as->a_contents);
782 	mutex_enter(&newas->a_contents);
783 	AS_SETBUSY(newas);
784 	mutex_exit(&newas->a_contents);
785 
786 
787 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
788 
789 		if (seg->s_flags & S_PURGE)
790 			continue;
791 
792 		newseg = seg_alloc(newas, seg->s_base, seg->s_size);
793 		if (newseg == NULL) {
794 			AS_LOCK_EXIT(newas, &newas->a_lock);
795 			as_setwatch(as);
796 			mutex_enter(&as->a_contents);
797 			AS_CLRBUSY(as);
798 			mutex_exit(&as->a_contents);
799 			AS_LOCK_EXIT(as, &as->a_lock);
800 			as_free(newas);
801 			return (-1);
802 		}
803 		if ((error = SEGOP_DUP(seg, newseg)) != 0) {
804 			/*
805 			 * We call seg_free() on the new seg
806 			 * because the segment is not set up
807 			 * completely; i.e. it has no ops.
808 			 */
809 			as_setwatch(as);
810 			mutex_enter(&as->a_contents);
811 			AS_CLRBUSY(as);
812 			mutex_exit(&as->a_contents);
813 			AS_LOCK_EXIT(as, &as->a_lock);
814 			seg_free(newseg);
815 			AS_LOCK_EXIT(newas, &newas->a_lock);
816 			as_free(newas);
817 			return (error);
818 		}
819 		newas->a_size += seg->s_size;
820 	}
821 
822 	error = hat_dup(as->a_hat, newas->a_hat, NULL, 0, HAT_DUP_ALL);
823 	if (as->a_xhat != NULL)
824 		error |= xhat_dup_all(as, newas, NULL, 0, HAT_DUP_ALL);
825 
826 	mutex_enter(&newas->a_contents);
827 	AS_CLRBUSY(newas);
828 	mutex_exit(&newas->a_contents);
829 	AS_LOCK_EXIT(newas, &newas->a_lock);
830 
831 	as_setwatch(as);
832 	mutex_enter(&as->a_contents);
833 	AS_CLRBUSY(as);
834 	mutex_exit(&as->a_contents);
835 	AS_LOCK_EXIT(as, &as->a_lock);
836 	if (error != 0) {
837 		as_free(newas);
838 		return (error);
839 	}
840 	*outas = newas;
841 	return (0);
842 }
843 
844 /*
845  * Handle a ``fault'' at addr for size bytes.
846  */
847 faultcode_t
848 as_fault(struct hat *hat, struct as *as, caddr_t addr, size_t size,
849 	enum fault_type type, enum seg_rw rw)
850 {
851 	struct seg *seg;
852 	caddr_t raddr;			/* rounded down addr */
853 	size_t rsize;			/* rounded up size */
854 	size_t ssize;
855 	faultcode_t res = 0;
856 	caddr_t addrsav;
857 	struct seg *segsav;
858 	int as_lock_held;
859 	klwp_t *lwp = ttolwp(curthread);
860 	int is_xhat = 0;
861 	int holding_wpage = 0;
862 	extern struct seg_ops   segdev_ops;
863 
864 
865 
866 	if (as->a_hat != hat) {
867 		/* This must be an XHAT then */
868 		is_xhat = 1;
869 
870 		if ((type != F_INVAL) || (as == &kas))
871 			return (FC_NOSUPPORT);
872 	}
873 
874 retry:
875 	if (!is_xhat) {
876 		/*
877 		 * Indicate that the lwp is not to be stopped while waiting
878 		 * for a pagefault.  This is to avoid deadlock while debugging
879 		 * a process via /proc over NFS (in particular).
880 		 */
881 		if (lwp != NULL)
882 			lwp->lwp_nostop++;
883 
884 		/*
885 		 * same length must be used when we softlock and softunlock.
886 		 * We don't support softunlocking lengths less than
887 		 * the original length when there is largepage support.
888 		 * See seg_dev.c for more comments.
889 		 */
890 		switch (type) {
891 
892 		case F_SOFTLOCK:
893 			CPU_STATS_ADD_K(vm, softlock, 1);
894 			break;
895 
896 		case F_SOFTUNLOCK:
897 			break;
898 
899 		case F_PROT:
900 			CPU_STATS_ADD_K(vm, prot_fault, 1);
901 			break;
902 
903 		case F_INVAL:
904 			CPU_STATS_ENTER_K();
905 			CPU_STATS_ADDQ(CPU, vm, as_fault, 1);
906 			if (as == &kas)
907 				CPU_STATS_ADDQ(CPU, vm, kernel_asflt, 1);
908 			CPU_STATS_EXIT_K();
909 			break;
910 		}
911 	}
912 
913 	/* Kernel probe */
914 	TNF_PROBE_3(address_fault, "vm pagefault", /* CSTYLED */,
915 		tnf_opaque,	address,	addr,
916 		tnf_fault_type,	fault_type,	type,
917 		tnf_seg_access,	access,		rw);
918 
919 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
920 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
921 		(size_t)raddr;
922 
923 	/*
924 	 * XXX -- Don't grab the as lock for segkmap. We should grab it for
925 	 * correctness, but then we could be stuck holding this lock for
926 	 * a LONG time if the fault needs to be resolved on a slow
927 	 * filesystem, and then no-one will be able to exec new commands,
928 	 * as exec'ing requires the write lock on the as.
929 	 */
930 	if (as == &kas && segkmap && segkmap->s_base <= raddr &&
931 	    raddr + size < segkmap->s_base + segkmap->s_size) {
932 		/*
933 		 * if (as==&kas), this can't be XHAT: we've already returned
934 		 * FC_NOSUPPORT.
935 		 */
936 		seg = segkmap;
937 		as_lock_held = 0;
938 	} else {
939 		AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
940 		if (is_xhat && avl_numnodes(&as->a_wpage) != 0) {
941 			/*
942 			 * Grab and hold the writers' lock on the as
943 			 * if the fault is to a watched page.
944 			 * This will keep CPUs from "peeking" at the
945 			 * address range while we're temporarily boosting
946 			 * the permissions for the XHAT device to
947 			 * resolve the fault in the segment layer.
948 			 *
949 			 * We could check whether faulted address
950 			 * is within a watched page and only then grab
951 			 * the writer lock, but this is simpler.
952 			 */
953 			AS_LOCK_EXIT(as, &as->a_lock);
954 			AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
955 		}
956 
957 		seg = as_segat(as, raddr);
958 		if (seg == NULL) {
959 			AS_LOCK_EXIT(as, &as->a_lock);
960 			if ((lwp != NULL) && (!is_xhat))
961 				lwp->lwp_nostop--;
962 			return (FC_NOMAP);
963 		}
964 
965 		as_lock_held = 1;
966 	}
967 
968 	addrsav = raddr;
969 	segsav = seg;
970 
971 	for (; rsize != 0; rsize -= ssize, raddr += ssize) {
972 		if (raddr >= seg->s_base + seg->s_size) {
973 			seg = AS_SEGNEXT(as, seg);
974 			if (seg == NULL || raddr != seg->s_base) {
975 				res = FC_NOMAP;
976 				break;
977 			}
978 		}
979 		if (raddr + rsize > seg->s_base + seg->s_size)
980 			ssize = seg->s_base + seg->s_size - raddr;
981 		else
982 			ssize = rsize;
983 
984 		if (!is_xhat || (seg->s_ops != &segdev_ops)) {
985 
986 			if (is_xhat && avl_numnodes(&as->a_wpage) != 0 &&
987 			    pr_is_watchpage_as(raddr, rw, as)) {
988 				/*
989 				 * Handle watch pages.  If we're faulting on a
990 				 * watched page from an X-hat, we have to
991 				 * restore the original permissions while we
992 				 * handle the fault.
993 				 */
994 				as_clearwatch(as);
995 				holding_wpage = 1;
996 			}
997 
998 			res = SEGOP_FAULT(hat, seg, raddr, ssize, type, rw);
999 
1000 			/* Restore watchpoints */
1001 			if (holding_wpage) {
1002 				as_setwatch(as);
1003 				holding_wpage = 0;
1004 			}
1005 
1006 			if (res != 0)
1007 				break;
1008 		} else {
1009 			/* XHAT does not support seg_dev */
1010 			res = FC_NOSUPPORT;
1011 			break;
1012 		}
1013 	}
1014 
1015 	/*
1016 	 * If we were SOFTLOCKing and encountered a failure,
1017 	 * we must SOFTUNLOCK the range we already did. (Maybe we
1018 	 * should just panic if we are SOFTLOCKing or even SOFTUNLOCKing
1019 	 * right here...)
1020 	 */
1021 	if (res != 0 && type == F_SOFTLOCK) {
1022 		for (seg = segsav; addrsav < raddr; addrsav += ssize) {
1023 			if (addrsav >= seg->s_base + seg->s_size)
1024 				seg = AS_SEGNEXT(as, seg);
1025 			ASSERT(seg != NULL);
1026 			/*
1027 			 * Now call the fault routine again to perform the
1028 			 * unlock using S_OTHER instead of the rw variable
1029 			 * since we never got a chance to touch the pages.
1030 			 */
1031 			if (raddr > seg->s_base + seg->s_size)
1032 				ssize = seg->s_base + seg->s_size - addrsav;
1033 			else
1034 				ssize = raddr - addrsav;
1035 			(void) SEGOP_FAULT(hat, seg, addrsav, ssize,
1036 			    F_SOFTUNLOCK, S_OTHER);
1037 		}
1038 	}
1039 	if (as_lock_held)
1040 		AS_LOCK_EXIT(as, &as->a_lock);
1041 	if ((lwp != NULL) && (!is_xhat))
1042 		lwp->lwp_nostop--;
1043 
1044 	/*
1045 	 * If the lower levels returned EDEADLK for a fault,
1046 	 * It means that we should retry the fault.  Let's wait
1047 	 * a bit also to let the deadlock causing condition clear.
1048 	 * This is part of a gross hack to work around a design flaw
1049 	 * in the ufs/sds logging code and should go away when the
1050 	 * logging code is re-designed to fix the problem. See bug
1051 	 * 4125102 for details of the problem.
1052 	 */
1053 	if (FC_ERRNO(res) == EDEADLK) {
1054 		delay(deadlk_wait);
1055 		res = 0;
1056 		goto retry;
1057 	}
1058 	return (res);
1059 }
1060 
1061 
1062 
1063 /*
1064  * Asynchronous ``fault'' at addr for size bytes.
1065  */
1066 faultcode_t
1067 as_faulta(struct as *as, caddr_t addr, size_t size)
1068 {
1069 	struct seg *seg;
1070 	caddr_t raddr;			/* rounded down addr */
1071 	size_t rsize;			/* rounded up size */
1072 	faultcode_t res = 0;
1073 	klwp_t *lwp = ttolwp(curthread);
1074 
1075 retry:
1076 	/*
1077 	 * Indicate that the lwp is not to be stopped while waiting
1078 	 * for a pagefault.  This is to avoid deadlock while debugging
1079 	 * a process via /proc over NFS (in particular).
1080 	 */
1081 	if (lwp != NULL)
1082 		lwp->lwp_nostop++;
1083 
1084 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
1085 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
1086 		(size_t)raddr;
1087 
1088 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
1089 	seg = as_segat(as, raddr);
1090 	if (seg == NULL) {
1091 		AS_LOCK_EXIT(as, &as->a_lock);
1092 		if (lwp != NULL)
1093 			lwp->lwp_nostop--;
1094 		return (FC_NOMAP);
1095 	}
1096 
1097 	for (; rsize != 0; rsize -= PAGESIZE, raddr += PAGESIZE) {
1098 		if (raddr >= seg->s_base + seg->s_size) {
1099 			seg = AS_SEGNEXT(as, seg);
1100 			if (seg == NULL || raddr != seg->s_base) {
1101 				res = FC_NOMAP;
1102 				break;
1103 			}
1104 		}
1105 		res = SEGOP_FAULTA(seg, raddr);
1106 		if (res != 0)
1107 			break;
1108 	}
1109 	AS_LOCK_EXIT(as, &as->a_lock);
1110 	if (lwp != NULL)
1111 		lwp->lwp_nostop--;
1112 	/*
1113 	 * If the lower levels returned EDEADLK for a fault,
1114 	 * It means that we should retry the fault.  Let's wait
1115 	 * a bit also to let the deadlock causing condition clear.
1116 	 * This is part of a gross hack to work around a design flaw
1117 	 * in the ufs/sds logging code and should go away when the
1118 	 * logging code is re-designed to fix the problem. See bug
1119 	 * 4125102 for details of the problem.
1120 	 */
1121 	if (FC_ERRNO(res) == EDEADLK) {
1122 		delay(deadlk_wait);
1123 		res = 0;
1124 		goto retry;
1125 	}
1126 	return (res);
1127 }
1128 
1129 /*
1130  * Set the virtual mapping for the interval from [addr : addr + size)
1131  * in address space `as' to have the specified protection.
1132  * It is ok for the range to cross over several segments,
1133  * as long as they are contiguous.
1134  */
1135 int
1136 as_setprot(struct as *as, caddr_t addr, size_t size, uint_t prot)
1137 {
1138 	struct seg *seg;
1139 	struct as_callback *cb;
1140 	size_t ssize;
1141 	caddr_t raddr;			/* rounded down addr */
1142 	size_t rsize;			/* rounded up size */
1143 	int error = 0, writer = 0;
1144 	caddr_t saveraddr;
1145 	size_t saversize;
1146 
1147 setprot_top:
1148 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
1149 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
1150 		(size_t)raddr;
1151 
1152 	if (raddr + rsize < raddr)		/* check for wraparound */
1153 		return (ENOMEM);
1154 
1155 	saveraddr = raddr;
1156 	saversize = rsize;
1157 
1158 	/*
1159 	 * Normally we only lock the as as a reader. But
1160 	 * if due to setprot the segment driver needs to split
1161 	 * a segment it will return IE_RETRY. Therefore we re-aquire
1162 	 * the as lock as a writer so the segment driver can change
1163 	 * the seg list. Also the segment driver will return IE_RETRY
1164 	 * after it has changed the segment list so we therefore keep
1165 	 * locking as a writer. Since these opeartions should be rare
1166 	 * want to only lock as a writer when necessary.
1167 	 */
1168 	if (writer || avl_numnodes(&as->a_wpage) != 0) {
1169 		AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
1170 	} else {
1171 		AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
1172 	}
1173 
1174 	as_clearwatchprot(as, raddr, rsize);
1175 	seg = as_segat(as, raddr);
1176 	if (seg == NULL) {
1177 		as_setwatch(as);
1178 		AS_LOCK_EXIT(as, &as->a_lock);
1179 		return (ENOMEM);
1180 	}
1181 
1182 	for (; rsize != 0; rsize -= ssize, raddr += ssize) {
1183 		if (raddr >= seg->s_base + seg->s_size) {
1184 			seg = AS_SEGNEXT(as, seg);
1185 			if (seg == NULL || raddr != seg->s_base) {
1186 				error = ENOMEM;
1187 				break;
1188 			}
1189 		}
1190 		if ((raddr + rsize) > (seg->s_base + seg->s_size))
1191 			ssize = seg->s_base + seg->s_size - raddr;
1192 		else
1193 			ssize = rsize;
1194 		error = SEGOP_SETPROT(seg, raddr, ssize, prot);
1195 
1196 		if (error == IE_NOMEM) {
1197 			error = EAGAIN;
1198 			break;
1199 		}
1200 
1201 		if (error == IE_RETRY) {
1202 			AS_LOCK_EXIT(as, &as->a_lock);
1203 			writer = 1;
1204 			goto setprot_top;
1205 		}
1206 
1207 		if (error == EAGAIN) {
1208 			/*
1209 			 * Make sure we have a_lock as writer.
1210 			 */
1211 			if (writer == 0) {
1212 				AS_LOCK_EXIT(as, &as->a_lock);
1213 				writer = 1;
1214 				goto setprot_top;
1215 			}
1216 
1217 			/*
1218 			 * Memory is currently locked.  It must be unlocked
1219 			 * before this operation can succeed through a retry.
1220 			 * The possible reasons for locked memory and
1221 			 * corresponding strategies for unlocking are:
1222 			 * (1) Normal I/O
1223 			 *	wait for a signal that the I/O operation
1224 			 *	has completed and the memory is unlocked.
1225 			 * (2) Asynchronous I/O
1226 			 *	The aio subsystem does not unlock pages when
1227 			 *	the I/O is completed. Those pages are unlocked
1228 			 *	when the application calls aiowait/aioerror.
1229 			 *	So, to prevent blocking forever, cv_broadcast()
1230 			 *	is done to wake up aio_cleanup_thread.
1231 			 *	Subsequently, segvn_reclaim will be called, and
1232 			 *	that will do AS_CLRUNMAPWAIT() and wake us up.
1233 			 * (3) Long term page locking:
1234 			 *	Drivers intending to have pages locked for a
1235 			 *	period considerably longer than for normal I/O
1236 			 *	(essentially forever) may have registered for a
1237 			 *	callback so they may unlock these pages on
1238 			 *	request. This is needed to allow this operation
1239 			 *	to succeed. Each entry on the callback list is
1240 			 *	examined. If the event or address range pertains
1241 			 *	the callback is invoked (unless it already is in
1242 			 *	progress). The a_contents lock must be dropped
1243 			 *	before the callback, so only one callback can
1244 			 *	be done at a time. Go to the top and do more
1245 			 *	until zero is returned. If zero is returned,
1246 			 *	either there were no callbacks for this event
1247 			 *	or they were already in progress.
1248 			 */
1249 			mutex_enter(&as->a_contents);
1250 			if (as->a_callbacks &&
1251 				(cb = as_find_callback(as, AS_SETPROT_EVENT,
1252 						seg->s_base, seg->s_size))) {
1253 				AS_LOCK_EXIT(as, &as->a_lock);
1254 				as_execute_callback(as, cb, AS_SETPROT_EVENT);
1255 			} else {
1256 				if (AS_ISUNMAPWAIT(as) == 0)
1257 					cv_broadcast(&as->a_cv);
1258 				AS_SETUNMAPWAIT(as);
1259 				AS_LOCK_EXIT(as, &as->a_lock);
1260 				while (AS_ISUNMAPWAIT(as))
1261 					cv_wait(&as->a_cv, &as->a_contents);
1262 			}
1263 			mutex_exit(&as->a_contents);
1264 			goto setprot_top;
1265 		} else if (error != 0)
1266 			break;
1267 	}
1268 	if (error != 0) {
1269 		as_setwatch(as);
1270 	} else {
1271 		as_setwatchprot(as, saveraddr, saversize, prot);
1272 	}
1273 	AS_LOCK_EXIT(as, &as->a_lock);
1274 	return (error);
1275 }
1276 
1277 /*
1278  * Check to make sure that the interval [addr, addr + size)
1279  * in address space `as' has at least the specified protection.
1280  * It is ok for the range to cross over several segments, as long
1281  * as they are contiguous.
1282  */
1283 int
1284 as_checkprot(struct as *as, caddr_t addr, size_t size, uint_t prot)
1285 {
1286 	struct seg *seg;
1287 	size_t ssize;
1288 	caddr_t raddr;			/* rounded down addr */
1289 	size_t rsize;			/* rounded up size */
1290 	int error = 0;
1291 
1292 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
1293 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
1294 		(size_t)raddr;
1295 
1296 	if (raddr + rsize < raddr)		/* check for wraparound */
1297 		return (ENOMEM);
1298 
1299 	/*
1300 	 * This is ugly as sin...
1301 	 * Normally, we only acquire the address space readers lock.
1302 	 * However, if the address space has watchpoints present,
1303 	 * we must acquire the writer lock on the address space for
1304 	 * the benefit of as_clearwatchprot() and as_setwatchprot().
1305 	 */
1306 	if (avl_numnodes(&as->a_wpage) != 0)
1307 		AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
1308 	else
1309 		AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
1310 	as_clearwatchprot(as, raddr, rsize);
1311 	seg = as_segat(as, raddr);
1312 	if (seg == NULL) {
1313 		as_setwatch(as);
1314 		AS_LOCK_EXIT(as, &as->a_lock);
1315 		return (ENOMEM);
1316 	}
1317 
1318 	for (; rsize != 0; rsize -= ssize, raddr += ssize) {
1319 		if (raddr >= seg->s_base + seg->s_size) {
1320 			seg = AS_SEGNEXT(as, seg);
1321 			if (seg == NULL || raddr != seg->s_base) {
1322 				error = ENOMEM;
1323 				break;
1324 			}
1325 		}
1326 		if ((raddr + rsize) > (seg->s_base + seg->s_size))
1327 			ssize = seg->s_base + seg->s_size - raddr;
1328 		else
1329 			ssize = rsize;
1330 
1331 		error = SEGOP_CHECKPROT(seg, raddr, ssize, prot);
1332 		if (error != 0)
1333 			break;
1334 	}
1335 	as_setwatch(as);
1336 	AS_LOCK_EXIT(as, &as->a_lock);
1337 	return (error);
1338 }
1339 
1340 int
1341 as_unmap(struct as *as, caddr_t addr, size_t size)
1342 {
1343 	struct seg *seg, *seg_next;
1344 	struct as_callback *cb;
1345 	caddr_t raddr, eaddr;
1346 	size_t ssize;
1347 	int err;
1348 
1349 top:
1350 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
1351 	eaddr = (caddr_t)(((uintptr_t)(addr + size) + PAGEOFFSET) &
1352 	    (uintptr_t)PAGEMASK);
1353 
1354 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
1355 
1356 	as->a_updatedir = 1;	/* inform /proc */
1357 	gethrestime(&as->a_updatetime);
1358 
1359 	/*
1360 	 * Use as_findseg to find the first segment in the range, then
1361 	 * step through the segments in order, following s_next.
1362 	 */
1363 	as_clearwatchprot(as, raddr, eaddr - raddr);
1364 
1365 	for (seg = as_findseg(as, raddr, 0); seg != NULL; seg = seg_next) {
1366 		if (eaddr <= seg->s_base)
1367 			break;		/* eaddr was in a gap; all done */
1368 
1369 		/* this is implied by the test above */
1370 		ASSERT(raddr < eaddr);
1371 
1372 		if (raddr < seg->s_base)
1373 			raddr = seg->s_base; 	/* raddr was in a gap */
1374 
1375 		if (eaddr > (seg->s_base + seg->s_size))
1376 			ssize = seg->s_base + seg->s_size - raddr;
1377 		else
1378 			ssize = eaddr - raddr;
1379 
1380 		/*
1381 		 * Save next segment pointer since seg can be
1382 		 * destroyed during the segment unmap operation.
1383 		 */
1384 		seg_next = AS_SEGNEXT(as, seg);
1385 
1386 		err = SEGOP_UNMAP(seg, raddr, ssize);
1387 		if (err == EAGAIN) {
1388 			/*
1389 			 * Memory is currently locked.  It must be unlocked
1390 			 * before this operation can succeed through a retry.
1391 			 * The possible reasons for locked memory and
1392 			 * corresponding strategies for unlocking are:
1393 			 * (1) Normal I/O
1394 			 *	wait for a signal that the I/O operation
1395 			 *	has completed and the memory is unlocked.
1396 			 * (2) Asynchronous I/O
1397 			 *	The aio subsystem does not unlock pages when
1398 			 *	the I/O is completed. Those pages are unlocked
1399 			 *	when the application calls aiowait/aioerror.
1400 			 *	So, to prevent blocking forever, cv_broadcast()
1401 			 *	is done to wake up aio_cleanup_thread.
1402 			 *	Subsequently, segvn_reclaim will be called, and
1403 			 *	that will do AS_CLRUNMAPWAIT() and wake us up.
1404 			 * (3) Long term page locking:
1405 			 *	Drivers intending to have pages locked for a
1406 			 *	period considerably longer than for normal I/O
1407 			 *	(essentially forever) may have registered for a
1408 			 *	callback so they may unlock these pages on
1409 			 *	request. This is needed to allow this operation
1410 			 *	to succeed. Each entry on the callback list is
1411 			 *	examined. If the event or address range pertains
1412 			 *	the callback is invoked (unless it already is in
1413 			 *	progress). The a_contents lock must be dropped
1414 			 *	before the callback, so only one callback can
1415 			 *	be done at a time. Go to the top and do more
1416 			 *	until zero is returned. If zero is returned,
1417 			 *	either there were no callbacks for this event
1418 			 *	or they were already in progress.
1419 			 */
1420 			as_setwatch(as);
1421 			mutex_enter(&as->a_contents);
1422 			if (as->a_callbacks &&
1423 				(cb = as_find_callback(as, AS_UNMAP_EVENT,
1424 						seg->s_base, seg->s_size))) {
1425 				AS_LOCK_EXIT(as, &as->a_lock);
1426 				as_execute_callback(as, cb, AS_UNMAP_EVENT);
1427 			} else {
1428 				if (AS_ISUNMAPWAIT(as) == 0)
1429 					cv_broadcast(&as->a_cv);
1430 				AS_SETUNMAPWAIT(as);
1431 				AS_LOCK_EXIT(as, &as->a_lock);
1432 				while (AS_ISUNMAPWAIT(as))
1433 					cv_wait(&as->a_cv, &as->a_contents);
1434 			}
1435 			mutex_exit(&as->a_contents);
1436 			goto top;
1437 		} else if (err == IE_RETRY) {
1438 			as_setwatch(as);
1439 			AS_LOCK_EXIT(as, &as->a_lock);
1440 			goto top;
1441 		} else if (err) {
1442 			as_setwatch(as);
1443 			AS_LOCK_EXIT(as, &as->a_lock);
1444 			return (-1);
1445 		}
1446 
1447 		as->a_size -= ssize;
1448 		raddr += ssize;
1449 	}
1450 	AS_LOCK_EXIT(as, &as->a_lock);
1451 	return (0);
1452 }
1453 
1454 static int
1455 as_map_segvn_segs(struct as *as, caddr_t addr, size_t size, uint_t szcvec,
1456     int (*crfp)(), struct segvn_crargs *vn_a, int *segcreated)
1457 {
1458 	uint_t szc;
1459 	uint_t nszc;
1460 	int error;
1461 	caddr_t a;
1462 	caddr_t eaddr;
1463 	size_t segsize;
1464 	struct seg *seg;
1465 	size_t pgsz;
1466 	int do_off = (vn_a->vp != NULL || vn_a->amp != NULL);
1467 	uint_t save_szcvec;
1468 
1469 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
1470 	ASSERT(IS_P2ALIGNED(addr, PAGESIZE));
1471 	ASSERT(IS_P2ALIGNED(size, PAGESIZE));
1472 	ASSERT(vn_a->vp == NULL || vn_a->amp == NULL);
1473 	if (!do_off) {
1474 		vn_a->offset = 0;
1475 	}
1476 
1477 	if (szcvec <= 1) {
1478 		seg = seg_alloc(as, addr, size);
1479 		if (seg == NULL) {
1480 			return (ENOMEM);
1481 		}
1482 		vn_a->szc = 0;
1483 		error = (*crfp)(seg, vn_a);
1484 		if (error != 0) {
1485 			seg_free(seg);
1486 		}
1487 		return (error);
1488 	}
1489 
1490 	eaddr = addr + size;
1491 	save_szcvec = szcvec;
1492 	szcvec >>= 1;
1493 	szc = 0;
1494 	nszc = 0;
1495 	while (szcvec) {
1496 		if ((szcvec & 0x1) == 0) {
1497 			nszc++;
1498 			szcvec >>= 1;
1499 			continue;
1500 		}
1501 		nszc++;
1502 		pgsz = page_get_pagesize(nszc);
1503 		a = (caddr_t)P2ROUNDUP((uintptr_t)addr, pgsz);
1504 		if (a != addr) {
1505 			ASSERT(a < eaddr);
1506 			segsize = a - addr;
1507 			seg = seg_alloc(as, addr, segsize);
1508 			if (seg == NULL) {
1509 				return (ENOMEM);
1510 			}
1511 			vn_a->szc = szc;
1512 			error = (*crfp)(seg, vn_a);
1513 			if (error != 0) {
1514 				seg_free(seg);
1515 				return (error);
1516 			}
1517 			*segcreated = 1;
1518 			if (do_off) {
1519 				vn_a->offset += segsize;
1520 			}
1521 			addr = a;
1522 		}
1523 		szc = nszc;
1524 		szcvec >>= 1;
1525 	}
1526 
1527 	ASSERT(addr < eaddr);
1528 	szcvec = save_szcvec | 1; /* add 8K pages */
1529 	while (szcvec) {
1530 		a = (caddr_t)P2ALIGN((uintptr_t)eaddr, pgsz);
1531 		ASSERT(a >= addr);
1532 		if (a != addr) {
1533 			segsize = a - addr;
1534 			seg = seg_alloc(as, addr, segsize);
1535 			if (seg == NULL) {
1536 				return (ENOMEM);
1537 			}
1538 			vn_a->szc = szc;
1539 			error = (*crfp)(seg, vn_a);
1540 			if (error != 0) {
1541 				seg_free(seg);
1542 				return (error);
1543 			}
1544 			*segcreated = 1;
1545 			if (do_off) {
1546 				vn_a->offset += segsize;
1547 			}
1548 			addr = a;
1549 		}
1550 		szcvec &= ~(1 << szc);
1551 		if (szcvec) {
1552 			szc = highbit(szcvec) - 1;
1553 			pgsz = page_get_pagesize(szc);
1554 		}
1555 	}
1556 	ASSERT(addr == eaddr);
1557 
1558 	return (0);
1559 }
1560 
1561 static int
1562 as_map_vnsegs(struct as *as, caddr_t addr, size_t size,
1563     int (*crfp)(), struct segvn_crargs *vn_a, int *segcreated)
1564 {
1565 	uint_t mapflags = vn_a->flags & (MAP_TEXT | MAP_INITDATA);
1566 	int type = (vn_a->type == MAP_SHARED) ? MAPPGSZC_SHM : MAPPGSZC_PRIVM;
1567 	uint_t szcvec = map_pgszcvec(addr, size, (uintptr_t)addr, mapflags,
1568 	    type, 0);
1569 	int error;
1570 	struct seg *seg;
1571 	struct vattr va;
1572 	u_offset_t eoff;
1573 	size_t save_size = 0;
1574 
1575 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
1576 	ASSERT(IS_P2ALIGNED(addr, PAGESIZE));
1577 	ASSERT(IS_P2ALIGNED(size, PAGESIZE));
1578 	ASSERT(vn_a->vp != NULL);
1579 	ASSERT(vn_a->amp == NULL);
1580 
1581 again:
1582 	if (szcvec <= 1) {
1583 		seg = seg_alloc(as, addr, size);
1584 		if (seg == NULL) {
1585 			return (ENOMEM);
1586 		}
1587 		vn_a->szc = 0;
1588 		error = (*crfp)(seg, vn_a);
1589 		if (error != 0) {
1590 			seg_free(seg);
1591 		}
1592 		return (error);
1593 	}
1594 
1595 	va.va_mask = AT_SIZE;
1596 	if (VOP_GETATTR(vn_a->vp, &va, ATTR_HINT, vn_a->cred) != 0) {
1597 		szcvec = 0;
1598 		goto again;
1599 	}
1600 	eoff = vn_a->offset & PAGEMASK;
1601 	if (eoff >= va.va_size) {
1602 		szcvec = 0;
1603 		goto again;
1604 	}
1605 	eoff += size;
1606 	if (btopr(va.va_size) < btopr(eoff)) {
1607 		save_size = size;
1608 		size = va.va_size - (vn_a->offset & PAGEMASK);
1609 		size = P2ROUNDUP_TYPED(size, PAGESIZE, size_t);
1610 		szcvec = map_pgszcvec(addr, size, (uintptr_t)addr, mapflags,
1611 		    type, 0);
1612 		if (szcvec <= 1) {
1613 			size = save_size;
1614 			goto again;
1615 		}
1616 	}
1617 
1618 	error = as_map_segvn_segs(as, addr, size, szcvec, crfp, vn_a,
1619 	    segcreated);
1620 	if (error != 0) {
1621 		return (error);
1622 	}
1623 	if (save_size) {
1624 		addr += size;
1625 		size = save_size - size;
1626 		szcvec = 0;
1627 		goto again;
1628 	}
1629 	return (0);
1630 }
1631 
1632 /*
1633  * as_map_ansegs: shared or private anonymous memory.  Note that the flags
1634  * passed to map_pgszvec cannot be MAP_INITDATA, for anon.
1635  */
1636 static int
1637 as_map_ansegs(struct as *as, caddr_t addr, size_t size,
1638     int (*crfp)(), struct segvn_crargs *vn_a, int *segcreated)
1639 {
1640 	uint_t szcvec;
1641 	uchar_t type;
1642 
1643 	ASSERT(vn_a->type == MAP_SHARED || vn_a->type == MAP_PRIVATE);
1644 	if (vn_a->type == MAP_SHARED) {
1645 		type = MAPPGSZC_SHM;
1646 	} else if (vn_a->type == MAP_PRIVATE) {
1647 		if (vn_a->szc == AS_MAP_HEAP) {
1648 			type = MAPPGSZC_HEAP;
1649 		} else if (vn_a->szc == AS_MAP_STACK) {
1650 			type = MAPPGSZC_STACK;
1651 		} else {
1652 			type = MAPPGSZC_PRIVM;
1653 		}
1654 	}
1655 	szcvec = map_pgszcvec(addr, size, vn_a->amp == NULL ?
1656 	    (uintptr_t)addr : (uintptr_t)P2ROUNDUP(vn_a->offset, PAGESIZE),
1657 	    (vn_a->flags & MAP_TEXT), type, 0);
1658 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
1659 	ASSERT(IS_P2ALIGNED(addr, PAGESIZE));
1660 	ASSERT(IS_P2ALIGNED(size, PAGESIZE));
1661 	ASSERT(vn_a->vp == NULL);
1662 
1663 	return (as_map_segvn_segs(as, addr, size, szcvec,
1664 	    crfp, vn_a, segcreated));
1665 }
1666 
1667 int
1668 as_map(struct as *as, caddr_t addr, size_t size, int (*crfp)(), void *argsp)
1669 {
1670 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
1671 	return (as_map_locked(as, addr, size, crfp, argsp));
1672 }
1673 
1674 int
1675 as_map_locked(struct as *as, caddr_t addr, size_t size, int (*crfp)(),
1676 		void *argsp)
1677 {
1678 	struct seg *seg = NULL;
1679 	caddr_t raddr;			/* rounded down addr */
1680 	size_t rsize;			/* rounded up size */
1681 	int error;
1682 	int unmap = 0;
1683 	struct proc *p = curproc;
1684 	struct segvn_crargs crargs;
1685 
1686 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
1687 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
1688 		(size_t)raddr;
1689 
1690 	/*
1691 	 * check for wrap around
1692 	 */
1693 	if ((raddr + rsize < raddr) || (as->a_size > (ULONG_MAX - size))) {
1694 		AS_LOCK_EXIT(as, &as->a_lock);
1695 		return (ENOMEM);
1696 	}
1697 
1698 	as->a_updatedir = 1;	/* inform /proc */
1699 	gethrestime(&as->a_updatetime);
1700 
1701 	if (as != &kas && as->a_size + rsize > (size_t)p->p_vmem_ctl) {
1702 		AS_LOCK_EXIT(as, &as->a_lock);
1703 
1704 		(void) rctl_action(rctlproc_legacy[RLIMIT_VMEM], p->p_rctls, p,
1705 		    RCA_UNSAFE_ALL);
1706 
1707 		return (ENOMEM);
1708 	}
1709 
1710 	if (AS_MAP_CHECK_VNODE_LPOOB(crfp, argsp)) {
1711 		crargs = *(struct segvn_crargs *)argsp;
1712 		error = as_map_vnsegs(as, raddr, rsize, crfp, &crargs, &unmap);
1713 		if (error != 0) {
1714 			AS_LOCK_EXIT(as, &as->a_lock);
1715 			if (unmap) {
1716 				(void) as_unmap(as, addr, size);
1717 			}
1718 			return (error);
1719 		}
1720 	} else if (AS_MAP_CHECK_ANON_LPOOB(crfp, argsp)) {
1721 		crargs = *(struct segvn_crargs *)argsp;
1722 		error = as_map_ansegs(as, raddr, rsize, crfp, &crargs, &unmap);
1723 		if (error != 0) {
1724 			AS_LOCK_EXIT(as, &as->a_lock);
1725 			if (unmap) {
1726 				(void) as_unmap(as, addr, size);
1727 			}
1728 			return (error);
1729 		}
1730 	} else {
1731 		seg = seg_alloc(as, addr, size);
1732 		if (seg == NULL) {
1733 			AS_LOCK_EXIT(as, &as->a_lock);
1734 			return (ENOMEM);
1735 		}
1736 
1737 		error = (*crfp)(seg, argsp);
1738 		if (error != 0) {
1739 			seg_free(seg);
1740 			AS_LOCK_EXIT(as, &as->a_lock);
1741 			return (error);
1742 		}
1743 	}
1744 
1745 	/*
1746 	 * Add size now so as_unmap will work if as_ctl fails.
1747 	 */
1748 	as->a_size += rsize;
1749 
1750 	as_setwatch(as);
1751 
1752 	/*
1753 	 * If the address space is locked,
1754 	 * establish memory locks for the new segment.
1755 	 */
1756 	mutex_enter(&as->a_contents);
1757 	if (AS_ISPGLCK(as)) {
1758 		mutex_exit(&as->a_contents);
1759 		AS_LOCK_EXIT(as, &as->a_lock);
1760 		error = as_ctl(as, addr, size, MC_LOCK, 0, 0, NULL, 0);
1761 		if (error != 0)
1762 			(void) as_unmap(as, addr, size);
1763 	} else {
1764 		mutex_exit(&as->a_contents);
1765 		AS_LOCK_EXIT(as, &as->a_lock);
1766 	}
1767 	return (error);
1768 }
1769 
1770 
1771 /*
1772  * Delete all segments in the address space marked with S_PURGE.
1773  * This is currently used for Sparc V9 nofault ASI segments (seg_nf.c).
1774  * These segments are deleted as a first step before calls to as_gap(), so
1775  * that they don't affect mmap() or shmat().
1776  */
1777 void
1778 as_purge(struct as *as)
1779 {
1780 	struct seg *seg;
1781 	struct seg *next_seg;
1782 
1783 	/*
1784 	 * the setting of NEEDSPURGE is protect by as_rangelock(), so
1785 	 * no need to grab a_contents mutex for this check
1786 	 */
1787 	if ((as->a_flags & AS_NEEDSPURGE) == 0)
1788 		return;
1789 
1790 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
1791 	next_seg = NULL;
1792 	seg = AS_SEGFIRST(as);
1793 	while (seg != NULL) {
1794 		next_seg = AS_SEGNEXT(as, seg);
1795 		if (seg->s_flags & S_PURGE)
1796 			SEGOP_UNMAP(seg, seg->s_base, seg->s_size);
1797 		seg = next_seg;
1798 	}
1799 	AS_LOCK_EXIT(as, &as->a_lock);
1800 
1801 	mutex_enter(&as->a_contents);
1802 	as->a_flags &= ~AS_NEEDSPURGE;
1803 	mutex_exit(&as->a_contents);
1804 }
1805 
1806 /*
1807  * Find a hole of at least size minlen within [base, base + len).
1808  *
1809  * If flags specifies AH_HI, the hole will have the highest possible address
1810  * in the range.  We use the as->a_lastgap field to figure out where to
1811  * start looking for a gap.
1812  *
1813  * Otherwise, the gap will have the lowest possible address.
1814  *
1815  * If flags specifies AH_CONTAIN, the hole will contain the address addr.
1816  *
1817  * If an adequate hole is found, base and len are set to reflect the part of
1818  * the hole that is within range, and 0 is returned, otherwise,
1819  * -1 is returned.
1820  *
1821  * NOTE: This routine is not correct when base+len overflows caddr_t.
1822  */
1823 int
1824 as_gap(struct as *as, size_t minlen, caddr_t *basep, size_t *lenp, uint_t flags,
1825     caddr_t addr)
1826 {
1827 	caddr_t lobound = *basep;
1828 	caddr_t hibound = lobound + *lenp;
1829 	struct seg *lseg, *hseg;
1830 	caddr_t lo, hi;
1831 	int forward;
1832 	caddr_t save_base;
1833 	size_t save_len;
1834 
1835 	save_base = *basep;
1836 	save_len = *lenp;
1837 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
1838 	if (AS_SEGFIRST(as) == NULL) {
1839 		if (valid_va_range(basep, lenp, minlen, flags & AH_DIR)) {
1840 			AS_LOCK_EXIT(as, &as->a_lock);
1841 			return (0);
1842 		} else {
1843 			AS_LOCK_EXIT(as, &as->a_lock);
1844 			*basep = save_base;
1845 			*lenp = save_len;
1846 			return (-1);
1847 		}
1848 	}
1849 
1850 	/*
1851 	 * Set up to iterate over all the inter-segment holes in the given
1852 	 * direction.  lseg is NULL for the lowest-addressed hole and hseg is
1853 	 * NULL for the highest-addressed hole.  If moving backwards, we reset
1854 	 * sseg to denote the highest-addressed segment.
1855 	 */
1856 	forward = (flags & AH_DIR) == AH_LO;
1857 	if (forward) {
1858 		hseg = as_findseg(as, lobound, 1);
1859 		lseg = AS_SEGPREV(as, hseg);
1860 	} else {
1861 
1862 		/*
1863 		 * If allocating at least as much as the last allocation,
1864 		 * use a_lastgap's base as a better estimate of hibound.
1865 		 */
1866 		if (as->a_lastgap &&
1867 		    minlen >= as->a_lastgap->s_size &&
1868 		    hibound >= as->a_lastgap->s_base)
1869 			hibound = as->a_lastgap->s_base;
1870 
1871 		hseg = as_findseg(as, hibound, 1);
1872 		if (hseg->s_base + hseg->s_size < hibound) {
1873 			lseg = hseg;
1874 			hseg = NULL;
1875 		} else {
1876 			lseg = AS_SEGPREV(as, hseg);
1877 		}
1878 	}
1879 
1880 	for (;;) {
1881 		/*
1882 		 * Set lo and hi to the hole's boundaries.  (We should really
1883 		 * use MAXADDR in place of hibound in the expression below,
1884 		 * but can't express it easily; using hibound in its place is
1885 		 * harmless.)
1886 		 */
1887 		lo = (lseg == NULL) ? 0 : lseg->s_base + lseg->s_size;
1888 		hi = (hseg == NULL) ? hibound : hseg->s_base;
1889 		/*
1890 		 * If the iteration has moved past the interval from lobound
1891 		 * to hibound it's pointless to continue.
1892 		 */
1893 		if ((forward && lo > hibound) || (!forward && hi < lobound))
1894 			break;
1895 		else if (lo > hibound || hi < lobound)
1896 			goto cont;
1897 		/*
1898 		 * Candidate hole lies at least partially within the allowable
1899 		 * range.  Restrict it to fall completely within that range,
1900 		 * i.e., to [max(lo, lobound), min(hi, hibound)].
1901 		 */
1902 		if (lo < lobound)
1903 			lo = lobound;
1904 		if (hi > hibound)
1905 			hi = hibound;
1906 		/*
1907 		 * Verify that the candidate hole is big enough and meets
1908 		 * hardware constraints.
1909 		 */
1910 		*basep = lo;
1911 		*lenp = hi - lo;
1912 		if (valid_va_range(basep, lenp, minlen,
1913 		    forward ? AH_LO : AH_HI) &&
1914 		    ((flags & AH_CONTAIN) == 0 ||
1915 		    (*basep <= addr && *basep + *lenp > addr))) {
1916 			if (!forward)
1917 				as->a_lastgap = hseg;
1918 			if (hseg != NULL)
1919 				as->a_lastgaphl = hseg;
1920 			else
1921 				as->a_lastgaphl = lseg;
1922 			AS_LOCK_EXIT(as, &as->a_lock);
1923 			return (0);
1924 		}
1925 	cont:
1926 		/*
1927 		 * Move to the next hole.
1928 		 */
1929 		if (forward) {
1930 			lseg = hseg;
1931 			if (lseg == NULL)
1932 				break;
1933 			hseg = AS_SEGNEXT(as, hseg);
1934 		} else {
1935 			hseg = lseg;
1936 			if (hseg == NULL)
1937 				break;
1938 			lseg = AS_SEGPREV(as, lseg);
1939 		}
1940 	}
1941 	*basep = save_base;
1942 	*lenp = save_len;
1943 	AS_LOCK_EXIT(as, &as->a_lock);
1944 	return (-1);
1945 }
1946 
1947 /*
1948  * Return the next range within [base, base + len) that is backed
1949  * with "real memory".  Skip holes and non-seg_vn segments.
1950  * We're lazy and only return one segment at a time.
1951  */
1952 int
1953 as_memory(struct as *as, caddr_t *basep, size_t *lenp)
1954 {
1955 	extern struct seg_ops segspt_shmops;	/* needs a header file */
1956 	struct seg *seg;
1957 	caddr_t addr, eaddr;
1958 	caddr_t segend;
1959 
1960 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
1961 
1962 	addr = *basep;
1963 	eaddr = addr + *lenp;
1964 
1965 	seg = as_findseg(as, addr, 0);
1966 	if (seg != NULL)
1967 		addr = MAX(seg->s_base, addr);
1968 
1969 	for (;;) {
1970 		if (seg == NULL || addr >= eaddr || eaddr <= seg->s_base) {
1971 			AS_LOCK_EXIT(as, &as->a_lock);
1972 			return (EINVAL);
1973 		}
1974 
1975 		if (seg->s_ops == &segvn_ops) {
1976 			segend = seg->s_base + seg->s_size;
1977 			break;
1978 		}
1979 
1980 		/*
1981 		 * We do ISM by looking into the private data
1982 		 * to determine the real size of the segment.
1983 		 */
1984 		if (seg->s_ops == &segspt_shmops) {
1985 			segend = seg->s_base + spt_realsize(seg);
1986 			if (addr < segend)
1987 				break;
1988 		}
1989 
1990 		seg = AS_SEGNEXT(as, seg);
1991 
1992 		if (seg != NULL)
1993 			addr = seg->s_base;
1994 	}
1995 
1996 	*basep = addr;
1997 
1998 	if (segend > eaddr)
1999 		*lenp = eaddr - addr;
2000 	else
2001 		*lenp = segend - addr;
2002 
2003 	AS_LOCK_EXIT(as, &as->a_lock);
2004 	return (0);
2005 }
2006 
2007 /*
2008  * Swap the pages associated with the address space as out to
2009  * secondary storage, returning the number of bytes actually
2010  * swapped.
2011  *
2012  * The value returned is intended to correlate well with the process's
2013  * memory requirements.  Its usefulness for this purpose depends on
2014  * how well the segment-level routines do at returning accurate
2015  * information.
2016  */
2017 size_t
2018 as_swapout(struct as *as)
2019 {
2020 	struct seg *seg;
2021 	size_t swpcnt = 0;
2022 
2023 	/*
2024 	 * Kernel-only processes have given up their address
2025 	 * spaces.  Of course, we shouldn't be attempting to
2026 	 * swap out such processes in the first place...
2027 	 */
2028 	if (as == NULL)
2029 		return (0);
2030 
2031 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
2032 
2033 	/* Prevent XHATs from attaching */
2034 	mutex_enter(&as->a_contents);
2035 	AS_SETBUSY(as);
2036 	mutex_exit(&as->a_contents);
2037 
2038 
2039 	/*
2040 	 * Free all mapping resources associated with the address
2041 	 * space.  The segment-level swapout routines capitalize
2042 	 * on this unmapping by scavanging pages that have become
2043 	 * unmapped here.
2044 	 */
2045 	hat_swapout(as->a_hat);
2046 	if (as->a_xhat != NULL)
2047 		xhat_swapout_all(as);
2048 
2049 	mutex_enter(&as->a_contents);
2050 	AS_CLRBUSY(as);
2051 	mutex_exit(&as->a_contents);
2052 
2053 	/*
2054 	 * Call the swapout routines of all segments in the address
2055 	 * space to do the actual work, accumulating the amount of
2056 	 * space reclaimed.
2057 	 */
2058 	for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
2059 		struct seg_ops *ov = seg->s_ops;
2060 
2061 		/*
2062 		 * We have to check to see if the seg has
2063 		 * an ops vector because the seg may have
2064 		 * been in the middle of being set up when
2065 		 * the process was picked for swapout.
2066 		 */
2067 		if ((ov != NULL) && (ov->swapout != NULL))
2068 			swpcnt += SEGOP_SWAPOUT(seg);
2069 	}
2070 	AS_LOCK_EXIT(as, &as->a_lock);
2071 	return (swpcnt);
2072 }
2073 
2074 /*
2075  * Determine whether data from the mappings in interval [addr, addr + size)
2076  * are in the primary memory (core) cache.
2077  */
2078 int
2079 as_incore(struct as *as, caddr_t addr,
2080     size_t size, char *vec, size_t *sizep)
2081 {
2082 	struct seg *seg;
2083 	size_t ssize;
2084 	caddr_t raddr;		/* rounded down addr */
2085 	size_t rsize;		/* rounded up size */
2086 	size_t isize;			/* iteration size */
2087 	int error = 0;		/* result, assume success */
2088 
2089 	*sizep = 0;
2090 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2091 	rsize = ((((size_t)addr + size) + PAGEOFFSET) & PAGEMASK) -
2092 		(size_t)raddr;
2093 
2094 	if (raddr + rsize < raddr)		/* check for wraparound */
2095 		return (ENOMEM);
2096 
2097 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
2098 	seg = as_segat(as, raddr);
2099 	if (seg == NULL) {
2100 		AS_LOCK_EXIT(as, &as->a_lock);
2101 		return (-1);
2102 	}
2103 
2104 	for (; rsize != 0; rsize -= ssize, raddr += ssize) {
2105 		if (raddr >= seg->s_base + seg->s_size) {
2106 			seg = AS_SEGNEXT(as, seg);
2107 			if (seg == NULL || raddr != seg->s_base) {
2108 				error = -1;
2109 				break;
2110 			}
2111 		}
2112 		if ((raddr + rsize) > (seg->s_base + seg->s_size))
2113 			ssize = seg->s_base + seg->s_size - raddr;
2114 		else
2115 			ssize = rsize;
2116 		*sizep += isize = SEGOP_INCORE(seg, raddr, ssize, vec);
2117 		if (isize != ssize) {
2118 			error = -1;
2119 			break;
2120 		}
2121 		vec += btopr(ssize);
2122 	}
2123 	AS_LOCK_EXIT(as, &as->a_lock);
2124 	return (error);
2125 }
2126 
2127 static void
2128 as_segunlock(struct seg *seg, caddr_t addr, int attr,
2129 	ulong_t *bitmap, size_t position, size_t npages)
2130 {
2131 	caddr_t	range_start;
2132 	size_t	pos1 = position;
2133 	size_t	pos2;
2134 	size_t	size;
2135 	size_t  end_pos = npages + position;
2136 
2137 	while (bt_range(bitmap, &pos1, &pos2, end_pos)) {
2138 		size = ptob((pos2 - pos1));
2139 		range_start = (caddr_t)((uintptr_t)addr +
2140 			ptob(pos1 - position));
2141 
2142 		(void) SEGOP_LOCKOP(seg, range_start, size, attr, MC_UNLOCK,
2143 			(ulong_t *)NULL, (size_t)NULL);
2144 		pos1 = pos2;
2145 	}
2146 }
2147 
2148 static void
2149 as_unlockerr(struct as *as, int attr, ulong_t *mlock_map,
2150 	caddr_t raddr, size_t rsize)
2151 {
2152 	struct seg *seg = as_segat(as, raddr);
2153 	size_t ssize;
2154 
2155 	while (rsize != 0) {
2156 		if (raddr >= seg->s_base + seg->s_size)
2157 			seg = AS_SEGNEXT(as, seg);
2158 
2159 		if ((raddr + rsize) > (seg->s_base + seg->s_size))
2160 			ssize = seg->s_base + seg->s_size - raddr;
2161 		else
2162 			ssize = rsize;
2163 
2164 		as_segunlock(seg, raddr, attr, mlock_map, 0, btopr(ssize));
2165 
2166 		rsize -= ssize;
2167 		raddr += ssize;
2168 	}
2169 }
2170 
2171 /*
2172  * Cache control operations over the interval [addr, addr + size) in
2173  * address space "as".
2174  */
2175 /*ARGSUSED*/
2176 int
2177 as_ctl(struct as *as, caddr_t addr, size_t size, int func, int attr,
2178     uintptr_t arg, ulong_t *lock_map, size_t pos)
2179 {
2180 	struct seg *seg;	/* working segment */
2181 	caddr_t raddr;		/* rounded down addr */
2182 	caddr_t initraddr;	/* saved initial rounded down addr */
2183 	size_t rsize;		/* rounded up size */
2184 	size_t initrsize;	/* saved initial rounded up size */
2185 	size_t ssize;		/* size of seg */
2186 	int error = 0;			/* result */
2187 	size_t mlock_size;	/* size of bitmap */
2188 	ulong_t *mlock_map;	/* pointer to bitmap used */
2189 				/* to represent the locked */
2190 				/* pages. */
2191 retry:
2192 	if (error == IE_RETRY)
2193 		AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
2194 	else
2195 		AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
2196 
2197 	/*
2198 	 * If these are address space lock/unlock operations, loop over
2199 	 * all segments in the address space, as appropriate.
2200 	 */
2201 	if (func == MC_LOCKAS) {
2202 		size_t npages, idx;
2203 		size_t rlen = 0;	/* rounded as length */
2204 
2205 		idx = pos;
2206 
2207 		if (arg & MCL_FUTURE) {
2208 			mutex_enter(&as->a_contents);
2209 			AS_SETPGLCK(as);
2210 			mutex_exit(&as->a_contents);
2211 		}
2212 		if ((arg & MCL_CURRENT) == 0) {
2213 			AS_LOCK_EXIT(as, &as->a_lock);
2214 			return (0);
2215 		}
2216 
2217 		seg = AS_SEGFIRST(as);
2218 		if (seg == NULL) {
2219 			AS_LOCK_EXIT(as, &as->a_lock);
2220 			return (0);
2221 		}
2222 
2223 		do {
2224 			raddr = (caddr_t)((uintptr_t)seg->s_base &
2225 			    (uintptr_t)PAGEMASK);
2226 			rlen += (((uintptr_t)(seg->s_base + seg->s_size) +
2227 				PAGEOFFSET) & PAGEMASK) - (uintptr_t)raddr;
2228 		} while ((seg = AS_SEGNEXT(as, seg)) != NULL);
2229 
2230 		mlock_size = BT_BITOUL(btopr(rlen));
2231 		if ((mlock_map = (ulong_t *)kmem_zalloc(mlock_size *
2232 			sizeof (ulong_t), KM_NOSLEEP)) == NULL) {
2233 				AS_LOCK_EXIT(as, &as->a_lock);
2234 				return (EAGAIN);
2235 		}
2236 
2237 		for (seg = AS_SEGFIRST(as); seg; seg = AS_SEGNEXT(as, seg)) {
2238 			error = SEGOP_LOCKOP(seg, seg->s_base,
2239 			    seg->s_size, attr, MC_LOCK, mlock_map, pos);
2240 			if (error != 0)
2241 				break;
2242 			pos += seg_pages(seg);
2243 		}
2244 
2245 		if (error) {
2246 			for (seg = AS_SEGFIRST(as); seg != NULL;
2247 				seg = AS_SEGNEXT(as, seg)) {
2248 
2249 				raddr = (caddr_t)((uintptr_t)seg->s_base &
2250 					(uintptr_t)PAGEMASK);
2251 				npages = seg_pages(seg);
2252 				as_segunlock(seg, raddr, attr, mlock_map,
2253 					idx, npages);
2254 				idx += npages;
2255 			}
2256 		}
2257 
2258 		kmem_free(mlock_map, mlock_size * sizeof (ulong_t));
2259 		AS_LOCK_EXIT(as, &as->a_lock);
2260 		goto lockerr;
2261 	} else if (func == MC_UNLOCKAS) {
2262 		mutex_enter(&as->a_contents);
2263 		AS_CLRPGLCK(as);
2264 		mutex_exit(&as->a_contents);
2265 
2266 		for (seg = AS_SEGFIRST(as); seg; seg = AS_SEGNEXT(as, seg)) {
2267 			error = SEGOP_LOCKOP(seg, seg->s_base,
2268 			    seg->s_size, attr, MC_UNLOCK, NULL, 0);
2269 			if (error != 0)
2270 				break;
2271 		}
2272 
2273 		AS_LOCK_EXIT(as, &as->a_lock);
2274 		goto lockerr;
2275 	}
2276 
2277 	/*
2278 	 * Normalize addresses and sizes.
2279 	 */
2280 	initraddr = raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2281 	initrsize = rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
2282 		(size_t)raddr;
2283 
2284 	if (raddr + rsize < raddr) {		/* check for wraparound */
2285 		AS_LOCK_EXIT(as, &as->a_lock);
2286 		return (ENOMEM);
2287 	}
2288 
2289 	/*
2290 	 * Get initial segment.
2291 	 */
2292 	if ((seg = as_segat(as, raddr)) == NULL) {
2293 		AS_LOCK_EXIT(as, &as->a_lock);
2294 		return (ENOMEM);
2295 	}
2296 
2297 	if (func == MC_LOCK) {
2298 		mlock_size = BT_BITOUL(btopr(rsize));
2299 		if ((mlock_map = (ulong_t *)kmem_zalloc(mlock_size *
2300 			sizeof (ulong_t), KM_NOSLEEP)) == NULL) {
2301 				AS_LOCK_EXIT(as, &as->a_lock);
2302 				return (EAGAIN);
2303 		}
2304 	}
2305 
2306 	/*
2307 	 * Loop over all segments.  If a hole in the address range is
2308 	 * discovered, then fail.  For each segment, perform the appropriate
2309 	 * control operation.
2310 	 */
2311 	while (rsize != 0) {
2312 
2313 		/*
2314 		 * Make sure there's no hole, calculate the portion
2315 		 * of the next segment to be operated over.
2316 		 */
2317 		if (raddr >= seg->s_base + seg->s_size) {
2318 			seg = AS_SEGNEXT(as, seg);
2319 			if (seg == NULL || raddr != seg->s_base) {
2320 				if (func == MC_LOCK) {
2321 					as_unlockerr(as, attr, mlock_map,
2322 						initraddr, initrsize - rsize);
2323 					kmem_free(mlock_map,
2324 						mlock_size * sizeof (ulong_t));
2325 				}
2326 				AS_LOCK_EXIT(as, &as->a_lock);
2327 				return (ENOMEM);
2328 			}
2329 		}
2330 		if ((raddr + rsize) > (seg->s_base + seg->s_size))
2331 			ssize = seg->s_base + seg->s_size - raddr;
2332 		else
2333 			ssize = rsize;
2334 
2335 		/*
2336 		 * Dispatch on specific function.
2337 		 */
2338 		switch (func) {
2339 
2340 		/*
2341 		 * Synchronize cached data from mappings with backing
2342 		 * objects.
2343 		 */
2344 		case MC_SYNC:
2345 			if (error = SEGOP_SYNC(seg, raddr, ssize,
2346 			    attr, (uint_t)arg)) {
2347 				AS_LOCK_EXIT(as, &as->a_lock);
2348 				return (error);
2349 			}
2350 			break;
2351 
2352 		/*
2353 		 * Lock pages in memory.
2354 		 */
2355 		case MC_LOCK:
2356 			if (error = SEGOP_LOCKOP(seg, raddr, ssize,
2357 				attr, func, mlock_map, pos)) {
2358 				as_unlockerr(as, attr, mlock_map, initraddr,
2359 					initrsize - rsize + ssize);
2360 				kmem_free(mlock_map, mlock_size *
2361 					sizeof (ulong_t));
2362 				AS_LOCK_EXIT(as, &as->a_lock);
2363 				goto lockerr;
2364 			}
2365 			break;
2366 
2367 		/*
2368 		 * Unlock mapped pages.
2369 		 */
2370 		case MC_UNLOCK:
2371 			(void) SEGOP_LOCKOP(seg, raddr, ssize, attr, func,
2372 				(ulong_t *)NULL, (size_t)NULL);
2373 			break;
2374 
2375 		/*
2376 		 * Store VM advise for mapped pages in segment layer.
2377 		 */
2378 		case MC_ADVISE:
2379 			error = SEGOP_ADVISE(seg, raddr, ssize, (uint_t)arg);
2380 
2381 			/*
2382 			 * Check for regular errors and special retry error
2383 			 */
2384 			if (error) {
2385 				if (error == IE_RETRY) {
2386 					/*
2387 					 * Need to acquire writers lock, so
2388 					 * have to drop readers lock and start
2389 					 * all over again
2390 					 */
2391 					AS_LOCK_EXIT(as, &as->a_lock);
2392 					goto retry;
2393 				} else if (error == IE_REATTACH) {
2394 					/*
2395 					 * Find segment for current address
2396 					 * because current segment just got
2397 					 * split or concatenated
2398 					 */
2399 					seg = as_segat(as, raddr);
2400 					if (seg == NULL) {
2401 						AS_LOCK_EXIT(as, &as->a_lock);
2402 						return (ENOMEM);
2403 					}
2404 				} else {
2405 					/*
2406 					 * Regular error
2407 					 */
2408 					AS_LOCK_EXIT(as, &as->a_lock);
2409 					return (error);
2410 				}
2411 			}
2412 			break;
2413 
2414 		/*
2415 		 * Can't happen.
2416 		 */
2417 		default:
2418 			panic("as_ctl: bad operation %d", func);
2419 			/*NOTREACHED*/
2420 		}
2421 
2422 		rsize -= ssize;
2423 		raddr += ssize;
2424 	}
2425 
2426 	if (func == MC_LOCK)
2427 		kmem_free(mlock_map, mlock_size * sizeof (ulong_t));
2428 	AS_LOCK_EXIT(as, &as->a_lock);
2429 	return (0);
2430 lockerr:
2431 
2432 	/*
2433 	 * If the lower levels returned EDEADLK for a segment lockop,
2434 	 * it means that we should retry the operation.  Let's wait
2435 	 * a bit also to let the deadlock causing condition clear.
2436 	 * This is part of a gross hack to work around a design flaw
2437 	 * in the ufs/sds logging code and should go away when the
2438 	 * logging code is re-designed to fix the problem. See bug
2439 	 * 4125102 for details of the problem.
2440 	 */
2441 	if (error == EDEADLK) {
2442 		delay(deadlk_wait);
2443 		error = 0;
2444 		goto retry;
2445 	}
2446 	return (error);
2447 }
2448 
2449 /*
2450  * Special code for exec to move the stack segment from its interim
2451  * place in the old address to the right place in the new address space.
2452  */
2453 /*ARGSUSED*/
2454 int
2455 as_exec(struct as *oas, caddr_t ostka, size_t stksz,
2456     struct as *nas, caddr_t nstka, uint_t hatflag)
2457 {
2458 	struct seg *stkseg;
2459 
2460 	AS_LOCK_ENTER(oas, &oas->a_lock, RW_WRITER);
2461 	stkseg = as_segat(oas, ostka);
2462 	stkseg = as_removeseg(oas, stkseg);
2463 	ASSERT(stkseg != NULL);
2464 	ASSERT(stkseg->s_base == ostka && stkseg->s_size == stksz);
2465 	stkseg->s_as = nas;
2466 	stkseg->s_base = nstka;
2467 
2468 	/*
2469 	 * It's ok to lock the address space we are about to exec to.
2470 	 */
2471 	AS_LOCK_ENTER(nas, &nas->a_lock, RW_WRITER);
2472 	ASSERT(avl_numnodes(&nas->a_wpage) == 0);
2473 	nas->a_size += stkseg->s_size;
2474 	oas->a_size -= stkseg->s_size;
2475 	(void) as_addseg(nas, stkseg);
2476 	AS_LOCK_EXIT(nas, &nas->a_lock);
2477 	AS_LOCK_EXIT(oas, &oas->a_lock);
2478 	return (0);
2479 }
2480 
2481 static int
2482 f_decode(faultcode_t fault_err)
2483 {
2484 	int error = 0;
2485 
2486 	switch (FC_CODE(fault_err)) {
2487 	case FC_OBJERR:
2488 		error = FC_ERRNO(fault_err);
2489 		break;
2490 	case FC_PROT:
2491 		error = EACCES;
2492 		break;
2493 	default:
2494 		error = EFAULT;
2495 		break;
2496 	}
2497 	return (error);
2498 }
2499 
2500 /*
2501  * lock pages in a given address space. Return shadow list. If
2502  * the list is NULL, the MMU mapping is also locked.
2503  */
2504 int
2505 as_pagelock(struct as *as, struct page ***ppp, caddr_t addr,
2506     size_t size, enum seg_rw rw)
2507 {
2508 	size_t rsize;
2509 	caddr_t base;
2510 	caddr_t raddr;
2511 	faultcode_t fault_err;
2512 	struct seg *seg;
2513 	int res;
2514 	int prefaulted = 0;
2515 
2516 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_AS_LOCK_START,
2517 	    "as_pagelock_start: addr %p size %ld", addr, size);
2518 
2519 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2520 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
2521 		(size_t)raddr;
2522 top:
2523 	/*
2524 	 * if the request crosses two segments let
2525 	 * as_fault handle it.
2526 	 */
2527 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
2528 	seg = as_findseg(as, addr, 0);
2529 	if ((seg == NULL) || ((base = seg->s_base) > addr) ||
2530 	    (addr + size) > base + seg->s_size) {
2531 		AS_LOCK_EXIT(as, &as->a_lock);
2532 		goto slow;
2533 	}
2534 
2535 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEG_LOCK_START,
2536 	    "seg_lock_1_start: raddr %p rsize %ld", raddr, rsize);
2537 
2538 	/*
2539 	 * try to lock pages and pass back shadow list
2540 	 */
2541 	res = SEGOP_PAGELOCK(seg, raddr, rsize, ppp, L_PAGELOCK, rw);
2542 
2543 	TRACE_0(TR_FAC_PHYSIO, TR_PHYSIO_SEG_LOCK_END, "seg_lock_1_end");
2544 	AS_LOCK_EXIT(as, &as->a_lock);
2545 	if (res == 0) {
2546 		return (0);
2547 	} else if (res == ENOTSUP || prefaulted) {
2548 		/*
2549 		 * (1) segment driver doesn't support PAGELOCK fastpath, or
2550 		 * (2) we've already tried fast path unsuccessfully after
2551 		 *    faulting in the addr range below; system might be
2552 		 *    thrashing or there may not be enough availrmem.
2553 		 */
2554 		goto slow;
2555 	}
2556 
2557 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_AS_FAULT_START,
2558 	    "as_fault_start: addr %p size %ld", addr, size);
2559 
2560 	/*
2561 	 * we might get here because of some COW fault or non
2562 	 * existing page. Let as_fault deal with it. Just load
2563 	 * the page, don't lock the MMU mapping.
2564 	 */
2565 	fault_err = as_fault(as->a_hat, as, addr, size, F_INVAL, rw);
2566 	if (fault_err != 0) {
2567 		return (f_decode(fault_err));
2568 	}
2569 
2570 	prefaulted = 1;
2571 
2572 	/*
2573 	 * try fast path again; since we've dropped a_lock,
2574 	 * we need to try the dance from the start to see if
2575 	 * the addr range is still valid.
2576 	 */
2577 	goto top;
2578 slow:
2579 	/*
2580 	 * load the page and lock the MMU mapping.
2581 	 */
2582 	fault_err = as_fault(as->a_hat, as, addr, size, F_SOFTLOCK, rw);
2583 	if (fault_err != 0) {
2584 		return (f_decode(fault_err));
2585 	}
2586 	*ppp = NULL;
2587 
2588 	TRACE_0(TR_FAC_PHYSIO, TR_PHYSIO_AS_LOCK_END, "as_pagelock_end");
2589 	return (0);
2590 }
2591 
2592 /*
2593  * unlock pages in a given address range
2594  */
2595 void
2596 as_pageunlock(struct as *as, struct page **pp, caddr_t addr, size_t size,
2597     enum seg_rw rw)
2598 {
2599 	struct seg *seg;
2600 	size_t rsize;
2601 	caddr_t raddr;
2602 
2603 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_AS_UNLOCK_START,
2604 	    "as_pageunlock_start: addr %p size %ld", addr, size);
2605 
2606 	/*
2607 	 * if the shadow list is NULL, as_pagelock was
2608 	 * falling back to as_fault
2609 	 */
2610 	if (pp == NULL) {
2611 		(void) as_fault(as->a_hat, as, addr, size, F_SOFTUNLOCK, rw);
2612 		return;
2613 	}
2614 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2615 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
2616 		(size_t)raddr;
2617 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
2618 	seg = as_findseg(as, addr, 0);
2619 	ASSERT(seg);
2620 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEG_UNLOCK_START,
2621 	    "seg_unlock_start: raddr %p rsize %ld", raddr, rsize);
2622 	SEGOP_PAGELOCK(seg, raddr, rsize, &pp, L_PAGEUNLOCK, rw);
2623 	AS_LOCK_EXIT(as, &as->a_lock);
2624 	TRACE_0(TR_FAC_PHYSIO, TR_PHYSIO_AS_UNLOCK_END, "as_pageunlock_end");
2625 }
2626 
2627 /*
2628  * reclaim cached pages in a given address range
2629  */
2630 void
2631 as_pagereclaim(struct as *as, struct page **pp, caddr_t addr,
2632     size_t size, enum seg_rw rw)
2633 {
2634 	struct seg *seg;
2635 	size_t rsize;
2636 	caddr_t raddr;
2637 
2638 	ASSERT(AS_READ_HELD(as, &as->a_lock));
2639 	ASSERT(pp != NULL);
2640 
2641 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
2642 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
2643 		(size_t)raddr;
2644 	seg = as_findseg(as, addr, 0);
2645 	ASSERT(seg);
2646 	SEGOP_PAGELOCK(seg, raddr, rsize, &pp, L_PAGERECLAIM, rw);
2647 }
2648 
2649 #define	MAXPAGEFLIP	4
2650 #define	MAXPAGEFLIPSIZ	MAXPAGEFLIP*PAGESIZE
2651 
2652 int
2653 as_setpagesize(struct as *as, caddr_t addr, size_t size, uint_t szc,
2654     boolean_t wait)
2655 {
2656 	struct seg *seg;
2657 	size_t ssize;
2658 	caddr_t raddr;			/* rounded down addr */
2659 	size_t rsize;			/* rounded up size */
2660 	int error = 0;
2661 	size_t pgsz = page_get_pagesize(szc);
2662 
2663 setpgsz_top:
2664 	if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(size, pgsz)) {
2665 		return (EINVAL);
2666 	}
2667 
2668 	raddr = addr;
2669 	rsize = size;
2670 
2671 	if (raddr + rsize < raddr)		/* check for wraparound */
2672 		return (ENOMEM);
2673 
2674 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
2675 	as_clearwatchprot(as, raddr, rsize);
2676 	seg = as_segat(as, raddr);
2677 	if (seg == NULL) {
2678 		as_setwatch(as);
2679 		AS_LOCK_EXIT(as, &as->a_lock);
2680 		return (ENOMEM);
2681 	}
2682 
2683 	for (; rsize != 0; rsize -= ssize, raddr += ssize) {
2684 		if (raddr >= seg->s_base + seg->s_size) {
2685 			seg = AS_SEGNEXT(as, seg);
2686 			if (seg == NULL || raddr != seg->s_base) {
2687 				error = ENOMEM;
2688 				break;
2689 			}
2690 		}
2691 		if ((raddr + rsize) > (seg->s_base + seg->s_size)) {
2692 			ssize = seg->s_base + seg->s_size - raddr;
2693 		} else {
2694 			ssize = rsize;
2695 		}
2696 
2697 		error = SEGOP_SETPAGESIZE(seg, raddr, ssize, szc);
2698 
2699 		if (error == IE_NOMEM) {
2700 			error = EAGAIN;
2701 			break;
2702 		}
2703 
2704 		if (error == IE_RETRY) {
2705 			AS_LOCK_EXIT(as, &as->a_lock);
2706 			goto setpgsz_top;
2707 		}
2708 
2709 		if (error == ENOTSUP) {
2710 			error = EINVAL;
2711 			break;
2712 		}
2713 
2714 		if (wait && (error == EAGAIN)) {
2715 			/*
2716 			 * Memory is currently locked.  It must be unlocked
2717 			 * before this operation can succeed through a retry.
2718 			 * The possible reasons for locked memory and
2719 			 * corresponding strategies for unlocking are:
2720 			 * (1) Normal I/O
2721 			 *	wait for a signal that the I/O operation
2722 			 *	has completed and the memory is unlocked.
2723 			 * (2) Asynchronous I/O
2724 			 *	The aio subsystem does not unlock pages when
2725 			 *	the I/O is completed. Those pages are unlocked
2726 			 *	when the application calls aiowait/aioerror.
2727 			 *	So, to prevent blocking forever, cv_broadcast()
2728 			 *	is done to wake up aio_cleanup_thread.
2729 			 *	Subsequently, segvn_reclaim will be called, and
2730 			 *	that will do AS_CLRUNMAPWAIT() and wake us up.
2731 			 * (3) Long term page locking:
2732 			 *	This is not relevant for as_setpagesize()
2733 			 *	because we cannot change the page size for
2734 			 *	driver memory. The attempt to do so will
2735 			 *	fail with a different error than EAGAIN so
2736 			 *	there's no need to trigger as callbacks like
2737 			 *	as_unmap, as_setprot or as_free would do.
2738 			 */
2739 			mutex_enter(&as->a_contents);
2740 			if (AS_ISUNMAPWAIT(as) == 0) {
2741 				cv_broadcast(&as->a_cv);
2742 			}
2743 			AS_SETUNMAPWAIT(as);
2744 			AS_LOCK_EXIT(as, &as->a_lock);
2745 			while (AS_ISUNMAPWAIT(as)) {
2746 				cv_wait(&as->a_cv, &as->a_contents);
2747 			}
2748 			mutex_exit(&as->a_contents);
2749 			goto setpgsz_top;
2750 		} else if (error != 0) {
2751 			break;
2752 		}
2753 	}
2754 	as_setwatch(as);
2755 	AS_LOCK_EXIT(as, &as->a_lock);
2756 	return (error);
2757 }
2758 
2759 /*
2760  * as_iset3_default_lpsize() just calls SEGOP_SETPAGESIZE() on all segments
2761  * in its chunk where s_szc is less than the szc we want to set.
2762  */
2763 static int
2764 as_iset3_default_lpsize(struct as *as, caddr_t raddr, size_t rsize, uint_t szc,
2765     int *retry)
2766 {
2767 	struct seg *seg;
2768 	size_t ssize;
2769 	int error;
2770 
2771 	seg = as_segat(as, raddr);
2772 	if (seg == NULL) {
2773 		panic("as_iset3_default_lpsize: no seg");
2774 	}
2775 
2776 	for (; rsize != 0; rsize -= ssize, raddr += ssize) {
2777 		if (raddr >= seg->s_base + seg->s_size) {
2778 			seg = AS_SEGNEXT(as, seg);
2779 			if (seg == NULL || raddr != seg->s_base) {
2780 				panic("as_iset3_default_lpsize: as changed");
2781 			}
2782 		}
2783 		if ((raddr + rsize) > (seg->s_base + seg->s_size)) {
2784 			ssize = seg->s_base + seg->s_size - raddr;
2785 		} else {
2786 			ssize = rsize;
2787 		}
2788 
2789 		if (szc > seg->s_szc) {
2790 			error = SEGOP_SETPAGESIZE(seg, raddr, ssize, szc);
2791 			/* Only retry on EINVAL segments that have no vnode. */
2792 			if (error == EINVAL) {
2793 				vnode_t *vp = NULL;
2794 				if ((SEGOP_GETTYPE(seg, raddr) & MAP_SHARED) &&
2795 				    (SEGOP_GETVP(seg, raddr, &vp) != 0 ||
2796 				    vp == NULL)) {
2797 					*retry = 1;
2798 				} else {
2799 					*retry = 0;
2800 				}
2801 			}
2802 			if (error) {
2803 				return (error);
2804 			}
2805 		}
2806 	}
2807 	return (0);
2808 }
2809 
2810 /*
2811  * as_iset2_default_lpsize() calls as_iset3_default_lpsize() to set the
2812  * pagesize on each segment in its range, but if any fails with EINVAL,
2813  * then it reduces the pagesizes to the next size in the bitmap and
2814  * retries as_iset3_default_lpsize(). The reason why the code retries
2815  * smaller allowed sizes on EINVAL is because (a) the anon offset may not
2816  * match the bigger sizes, and (b) it's hard to get this offset (to begin
2817  * with) to pass to map_pgszcvec().
2818  */
2819 static int
2820 as_iset2_default_lpsize(struct as *as, caddr_t addr, size_t size, uint_t szc,
2821     uint_t szcvec)
2822 {
2823 	int error;
2824 	int retry;
2825 
2826 	for (;;) {
2827 		error = as_iset3_default_lpsize(as, addr, size, szc, &retry);
2828 		if (error == EINVAL && retry) {
2829 			szcvec &= ~(1 << szc);
2830 			if (szcvec <= 1) {
2831 				return (EINVAL);
2832 			}
2833 			szc = highbit(szcvec) - 1;
2834 		} else {
2835 			return (error);
2836 		}
2837 	}
2838 }
2839 
2840 /*
2841  * as_iset1_default_lpsize() breaks its chunk into areas where existing
2842  * segments have a smaller szc than we want to set. For each such area,
2843  * it calls as_iset2_default_lpsize()
2844  */
2845 static int
2846 as_iset1_default_lpsize(struct as *as, caddr_t raddr, size_t rsize, uint_t szc,
2847     uint_t szcvec)
2848 {
2849 	struct seg *seg;
2850 	size_t ssize;
2851 	caddr_t setaddr = raddr;
2852 	size_t setsize = 0;
2853 	int set;
2854 	int error;
2855 
2856 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
2857 
2858 	seg = as_segat(as, raddr);
2859 	if (seg == NULL) {
2860 		panic("as_iset1_default_lpsize: no seg");
2861 	}
2862 	if (seg->s_szc < szc) {
2863 		set = 1;
2864 	} else {
2865 		set = 0;
2866 	}
2867 
2868 	for (; rsize != 0; rsize -= ssize, raddr += ssize, setsize += ssize) {
2869 		if (raddr >= seg->s_base + seg->s_size) {
2870 			seg = AS_SEGNEXT(as, seg);
2871 			if (seg == NULL || raddr != seg->s_base) {
2872 				panic("as_iset1_default_lpsize: as changed");
2873 			}
2874 			if (seg->s_szc >= szc && set) {
2875 				ASSERT(setsize != 0);
2876 				error = as_iset2_default_lpsize(as,
2877 				    setaddr, setsize, szc, szcvec);
2878 				if (error) {
2879 					return (error);
2880 				}
2881 				set = 0;
2882 			} else if (seg->s_szc < szc && !set) {
2883 				setaddr = raddr;
2884 				setsize = 0;
2885 				set = 1;
2886 			}
2887 		}
2888 		if ((raddr + rsize) > (seg->s_base + seg->s_size)) {
2889 			ssize = seg->s_base + seg->s_size - raddr;
2890 		} else {
2891 			ssize = rsize;
2892 		}
2893 	}
2894 	error = 0;
2895 	if (set) {
2896 		ASSERT(setsize != 0);
2897 		error = as_iset2_default_lpsize(as, setaddr, setsize,
2898 		    szc, szcvec);
2899 	}
2900 	return (error);
2901 }
2902 
2903 /*
2904  * as_iset_default_lpsize() breaks its chunk according to the size code bitmap
2905  * returned by map_pgszcvec() (similar to as_map_segvn_segs()), and passes each
2906  * chunk to as_iset1_default_lpsize().
2907  */
2908 static int
2909 as_iset_default_lpsize(struct as *as, caddr_t addr, size_t size, int flags,
2910     int type)
2911 {
2912 	int rtype = (type & MAP_SHARED) ? MAPPGSZC_SHM : MAPPGSZC_PRIVM;
2913 	uint_t szcvec = map_pgszcvec(addr, size, (uintptr_t)addr,
2914 					flags, rtype, 1);
2915 	uint_t szc;
2916 	uint_t nszc;
2917 	int error;
2918 	caddr_t a;
2919 	caddr_t eaddr;
2920 	size_t segsize;
2921 	size_t pgsz;
2922 	uint_t save_szcvec;
2923 
2924 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
2925 	ASSERT(IS_P2ALIGNED(addr, PAGESIZE));
2926 	ASSERT(IS_P2ALIGNED(size, PAGESIZE));
2927 
2928 	szcvec &= ~1;
2929 	if (szcvec <= 1) {	/* skip if base page size */
2930 		return (0);
2931 	}
2932 
2933 	/* Get the pagesize of the first larger page size. */
2934 	szc = lowbit(szcvec) - 1;
2935 	pgsz = page_get_pagesize(szc);
2936 	eaddr = addr + size;
2937 	addr = (caddr_t)P2ROUNDUP((uintptr_t)addr, pgsz);
2938 	eaddr = (caddr_t)P2ALIGN((uintptr_t)eaddr, pgsz);
2939 
2940 	save_szcvec = szcvec;
2941 	szcvec >>= (szc + 1);
2942 	nszc = szc;
2943 	while (szcvec) {
2944 		if ((szcvec & 0x1) == 0) {
2945 			nszc++;
2946 			szcvec >>= 1;
2947 			continue;
2948 		}
2949 		nszc++;
2950 		pgsz = page_get_pagesize(nszc);
2951 		a = (caddr_t)P2ROUNDUP((uintptr_t)addr, pgsz);
2952 		if (a != addr) {
2953 			ASSERT(szc > 0);
2954 			ASSERT(a < eaddr);
2955 			segsize = a - addr;
2956 			error = as_iset1_default_lpsize(as, addr, segsize, szc,
2957 			    save_szcvec);
2958 			if (error) {
2959 				return (error);
2960 			}
2961 			addr = a;
2962 		}
2963 		szc = nszc;
2964 		szcvec >>= 1;
2965 	}
2966 
2967 	ASSERT(addr < eaddr);
2968 	szcvec = save_szcvec;
2969 	while (szcvec) {
2970 		a = (caddr_t)P2ALIGN((uintptr_t)eaddr, pgsz);
2971 		ASSERT(a >= addr);
2972 		if (a != addr) {
2973 			ASSERT(szc > 0);
2974 			segsize = a - addr;
2975 			error = as_iset1_default_lpsize(as, addr, segsize, szc,
2976 			    save_szcvec);
2977 			if (error) {
2978 				return (error);
2979 			}
2980 			addr = a;
2981 		}
2982 		szcvec &= ~(1 << szc);
2983 		if (szcvec) {
2984 			szc = highbit(szcvec) - 1;
2985 			pgsz = page_get_pagesize(szc);
2986 		}
2987 	}
2988 	ASSERT(addr == eaddr);
2989 
2990 	return (0);
2991 }
2992 
2993 /*
2994  * Set the default large page size for the range. Called via memcntl with
2995  * page size set to 0. as_set_default_lpsize breaks the range down into
2996  * chunks with the same type/flags, ignores-non segvn segments, and passes
2997  * each chunk to as_iset_default_lpsize().
2998  */
2999 int
3000 as_set_default_lpsize(struct as *as, caddr_t addr, size_t size)
3001 {
3002 	struct seg *seg;
3003 	caddr_t raddr;
3004 	size_t rsize;
3005 	size_t ssize;
3006 	int rtype, rflags;
3007 	int stype, sflags;
3008 	int error;
3009 	caddr_t	setaddr;
3010 	size_t setsize;
3011 	int segvn;
3012 
3013 	if (size == 0)
3014 		return (0);
3015 
3016 	AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
3017 again:
3018 	error = 0;
3019 
3020 	raddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
3021 	rsize = (((size_t)(addr + size) + PAGEOFFSET) & PAGEMASK) -
3022 	    (size_t)raddr;
3023 
3024 	if (raddr + rsize < raddr) {		/* check for wraparound */
3025 		AS_LOCK_EXIT(as, &as->a_lock);
3026 		return (ENOMEM);
3027 	}
3028 	as_clearwatchprot(as, raddr, rsize);
3029 	seg = as_segat(as, raddr);
3030 	if (seg == NULL) {
3031 		as_setwatch(as);
3032 		AS_LOCK_EXIT(as, &as->a_lock);
3033 		return (ENOMEM);
3034 	}
3035 	if (seg->s_ops == &segvn_ops) {
3036 		rtype = SEGOP_GETTYPE(seg, addr);
3037 		rflags = rtype & (MAP_TEXT | MAP_INITDATA);
3038 		rtype = rtype & (MAP_SHARED | MAP_PRIVATE);
3039 		segvn = 1;
3040 	} else {
3041 		segvn = 0;
3042 	}
3043 	setaddr = raddr;
3044 	setsize = 0;
3045 
3046 	for (; rsize != 0; rsize -= ssize, raddr += ssize, setsize += ssize) {
3047 		if (raddr >= (seg->s_base + seg->s_size)) {
3048 			seg = AS_SEGNEXT(as, seg);
3049 			if (seg == NULL || raddr != seg->s_base) {
3050 				error = ENOMEM;
3051 				break;
3052 			}
3053 			if (seg->s_ops == &segvn_ops) {
3054 				stype = SEGOP_GETTYPE(seg, raddr);
3055 				sflags = stype & (MAP_TEXT | MAP_INITDATA);
3056 				stype &= (MAP_SHARED | MAP_PRIVATE);
3057 				if (segvn && (rflags != sflags ||
3058 				    rtype != stype)) {
3059 					/*
3060 					 * The next segment is also segvn but
3061 					 * has different flags and/or type.
3062 					 */
3063 					ASSERT(setsize != 0);
3064 					error = as_iset_default_lpsize(as,
3065 					    setaddr, setsize, rflags, rtype);
3066 					if (error) {
3067 						break;
3068 					}
3069 					rflags = sflags;
3070 					rtype = stype;
3071 					setaddr = raddr;
3072 					setsize = 0;
3073 				} else if (!segvn) {
3074 					rflags = sflags;
3075 					rtype = stype;
3076 					setaddr = raddr;
3077 					setsize = 0;
3078 					segvn = 1;
3079 				}
3080 			} else if (segvn) {
3081 				/* The next segment is not segvn. */
3082 				ASSERT(setsize != 0);
3083 				error = as_iset_default_lpsize(as,
3084 				    setaddr, setsize, rflags, rtype);
3085 				if (error) {
3086 					break;
3087 				}
3088 				segvn = 0;
3089 			}
3090 		}
3091 		if ((raddr + rsize) > (seg->s_base + seg->s_size)) {
3092 			ssize = seg->s_base + seg->s_size - raddr;
3093 		} else {
3094 			ssize = rsize;
3095 		}
3096 	}
3097 	if (error == 0 && segvn) {
3098 		/* The last chunk when rsize == 0. */
3099 		ASSERT(setsize != 0);
3100 		error = as_iset_default_lpsize(as, setaddr, setsize,
3101 		    rflags, rtype);
3102 	}
3103 
3104 	if (error == IE_RETRY) {
3105 		goto again;
3106 	} else if (error == IE_NOMEM) {
3107 		error = EAGAIN;
3108 	} else if (error == ENOTSUP) {
3109 		error = EINVAL;
3110 	} else if (error == EAGAIN) {
3111 		mutex_enter(&as->a_contents);
3112 		if (AS_ISUNMAPWAIT(as) == 0) {
3113 			cv_broadcast(&as->a_cv);
3114 		}
3115 		AS_SETUNMAPWAIT(as);
3116 		AS_LOCK_EXIT(as, &as->a_lock);
3117 		while (AS_ISUNMAPWAIT(as)) {
3118 			cv_wait(&as->a_cv, &as->a_contents);
3119 		}
3120 		mutex_exit(&as->a_contents);
3121 		AS_LOCK_ENTER(as, &as->a_lock, RW_WRITER);
3122 		goto again;
3123 	}
3124 
3125 	as_setwatch(as);
3126 	AS_LOCK_EXIT(as, &as->a_lock);
3127 	return (error);
3128 }
3129 
3130 /*
3131  * Setup all of the uninitialized watched pages that we can.
3132  */
3133 void
3134 as_setwatch(struct as *as)
3135 {
3136 	struct watched_page *pwp;
3137 	struct seg *seg;
3138 	caddr_t vaddr;
3139 	uint_t prot;
3140 	int  err, retrycnt;
3141 
3142 	if (avl_numnodes(&as->a_wpage) == 0)
3143 		return;
3144 
3145 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
3146 
3147 	for (pwp = avl_first(&as->a_wpage); pwp != NULL;
3148 	    pwp = AVL_NEXT(&as->a_wpage, pwp)) {
3149 		retrycnt = 0;
3150 	retry:
3151 		vaddr = pwp->wp_vaddr;
3152 		if (pwp->wp_oprot != 0 ||	/* already set up */
3153 		    (seg = as_segat(as, vaddr)) == NULL ||
3154 		    SEGOP_GETPROT(seg, vaddr, 0, &prot) != 0)
3155 			continue;
3156 
3157 		pwp->wp_oprot = prot;
3158 		if (pwp->wp_read)
3159 			prot &= ~(PROT_READ|PROT_WRITE|PROT_EXEC);
3160 		if (pwp->wp_write)
3161 			prot &= ~PROT_WRITE;
3162 		if (pwp->wp_exec)
3163 			prot &= ~(PROT_READ|PROT_WRITE|PROT_EXEC);
3164 		if (!(pwp->wp_flags & WP_NOWATCH) && prot != pwp->wp_oprot) {
3165 			err = SEGOP_SETPROT(seg, vaddr, PAGESIZE, prot);
3166 			if (err == IE_RETRY) {
3167 				pwp->wp_oprot = 0;
3168 				ASSERT(retrycnt == 0);
3169 				retrycnt++;
3170 				goto retry;
3171 			}
3172 		}
3173 		pwp->wp_prot = prot;
3174 	}
3175 }
3176 
3177 /*
3178  * Clear all of the watched pages in the address space.
3179  */
3180 void
3181 as_clearwatch(struct as *as)
3182 {
3183 	struct watched_page *pwp;
3184 	struct seg *seg;
3185 	caddr_t vaddr;
3186 	uint_t prot;
3187 	int err, retrycnt;
3188 
3189 	if (avl_numnodes(&as->a_wpage) == 0)
3190 		return;
3191 
3192 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
3193 
3194 	for (pwp = avl_first(&as->a_wpage); pwp != NULL;
3195 	    pwp = AVL_NEXT(&as->a_wpage, pwp)) {
3196 		retrycnt = 0;
3197 	retry:
3198 		vaddr = pwp->wp_vaddr;
3199 		if (pwp->wp_oprot == 0 ||	/* not set up */
3200 		    (seg = as_segat(as, vaddr)) == NULL)
3201 			continue;
3202 
3203 		if ((prot = pwp->wp_oprot) != pwp->wp_prot) {
3204 			err = SEGOP_SETPROT(seg, vaddr, PAGESIZE, prot);
3205 			if (err == IE_RETRY) {
3206 				ASSERT(retrycnt == 0);
3207 				retrycnt++;
3208 				goto retry;
3209 			}
3210 		}
3211 		pwp->wp_oprot = 0;
3212 		pwp->wp_prot = 0;
3213 	}
3214 }
3215 
3216 /*
3217  * Force a new setup for all the watched pages in the range.
3218  */
3219 static void
3220 as_setwatchprot(struct as *as, caddr_t addr, size_t size, uint_t prot)
3221 {
3222 	struct watched_page *pwp;
3223 	struct watched_page tpw;
3224 	caddr_t eaddr = addr + size;
3225 	caddr_t vaddr;
3226 	struct seg *seg;
3227 	int err, retrycnt;
3228 	uint_t	wprot;
3229 	avl_index_t where;
3230 
3231 	if (avl_numnodes(&as->a_wpage) == 0)
3232 		return;
3233 
3234 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
3235 
3236 	tpw.wp_vaddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
3237 	if ((pwp = avl_find(&as->a_wpage, &tpw, &where)) == NULL)
3238 		pwp = avl_nearest(&as->a_wpage, where, AVL_AFTER);
3239 
3240 	while (pwp != NULL && pwp->wp_vaddr < eaddr) {
3241 		retrycnt = 0;
3242 		vaddr = pwp->wp_vaddr;
3243 
3244 		wprot = prot;
3245 		if (pwp->wp_read)
3246 			wprot &= ~(PROT_READ|PROT_WRITE|PROT_EXEC);
3247 		if (pwp->wp_write)
3248 			wprot &= ~PROT_WRITE;
3249 		if (pwp->wp_exec)
3250 			wprot &= ~(PROT_READ|PROT_WRITE|PROT_EXEC);
3251 		if (!(pwp->wp_flags & WP_NOWATCH) && wprot != pwp->wp_oprot) {
3252 		retry:
3253 			seg = as_segat(as, vaddr);
3254 			if (seg == NULL) {
3255 				panic("as_setwatchprot: no seg");
3256 				/*NOTREACHED*/
3257 			}
3258 			err = SEGOP_SETPROT(seg, vaddr, PAGESIZE, wprot);
3259 			if (err == IE_RETRY) {
3260 				ASSERT(retrycnt == 0);
3261 				retrycnt++;
3262 				goto retry;
3263 			}
3264 		}
3265 		pwp->wp_oprot = prot;
3266 		pwp->wp_prot = wprot;
3267 
3268 		pwp = AVL_NEXT(&as->a_wpage, pwp);
3269 	}
3270 }
3271 
3272 /*
3273  * Clear all of the watched pages in the range.
3274  */
3275 static void
3276 as_clearwatchprot(struct as *as, caddr_t addr, size_t size)
3277 {
3278 	caddr_t eaddr = addr + size;
3279 	struct watched_page *pwp;
3280 	struct watched_page tpw;
3281 	uint_t prot;
3282 	struct seg *seg;
3283 	int err, retrycnt;
3284 	avl_index_t where;
3285 
3286 	if (avl_numnodes(&as->a_wpage) == 0)
3287 		return;
3288 
3289 	tpw.wp_vaddr = (caddr_t)((uintptr_t)addr & (uintptr_t)PAGEMASK);
3290 	if ((pwp = avl_find(&as->a_wpage, &tpw, &where)) == NULL)
3291 		pwp = avl_nearest(&as->a_wpage, where, AVL_AFTER);
3292 
3293 	ASSERT(AS_WRITE_HELD(as, &as->a_lock));
3294 
3295 	while (pwp != NULL && pwp->wp_vaddr < eaddr) {
3296 		ASSERT(addr >= pwp->wp_vaddr);
3297 
3298 		if ((prot = pwp->wp_oprot) != 0) {
3299 			retrycnt = 0;
3300 
3301 			if (prot != pwp->wp_prot) {
3302 			retry:
3303 				seg = as_segat(as, pwp->wp_vaddr);
3304 				if (seg == NULL)
3305 					continue;
3306 				err = SEGOP_SETPROT(seg, pwp->wp_vaddr,
3307 				    PAGESIZE, prot);
3308 				if (err == IE_RETRY) {
3309 					ASSERT(retrycnt == 0);
3310 					retrycnt++;
3311 					goto retry;
3312 
3313 				}
3314 			}
3315 			pwp->wp_oprot = 0;
3316 			pwp->wp_prot = 0;
3317 		}
3318 
3319 		pwp = AVL_NEXT(&as->a_wpage, pwp);
3320 	}
3321 }
3322 
3323 void
3324 as_signal_proc(struct as *as, k_siginfo_t *siginfo)
3325 {
3326 	struct proc *p;
3327 
3328 	mutex_enter(&pidlock);
3329 	for (p = practive; p; p = p->p_next) {
3330 		if (p->p_as == as) {
3331 			mutex_enter(&p->p_lock);
3332 			if (p->p_as == as)
3333 				sigaddq(p, NULL, siginfo, KM_NOSLEEP);
3334 			mutex_exit(&p->p_lock);
3335 		}
3336 	}
3337 	mutex_exit(&pidlock);
3338 }
3339 
3340 /*
3341  * return memory object ID
3342  */
3343 int
3344 as_getmemid(struct as *as, caddr_t addr, memid_t *memidp)
3345 {
3346 	struct seg	*seg;
3347 	int		sts;
3348 
3349 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
3350 	seg = as_segat(as, addr);
3351 	if (seg == NULL) {
3352 		AS_LOCK_EXIT(as, &as->a_lock);
3353 		return (EFAULT);
3354 	}
3355 	/*
3356 	 * catch old drivers which may not support getmemid
3357 	 */
3358 	if (seg->s_ops->getmemid == NULL) {
3359 		AS_LOCK_EXIT(as, &as->a_lock);
3360 		return (ENODEV);
3361 	}
3362 
3363 	sts = SEGOP_GETMEMID(seg, addr, memidp);
3364 
3365 	AS_LOCK_EXIT(as, &as->a_lock);
3366 	return (sts);
3367 }
3368