FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_map.c
1 /* $NetBSD: uvm_map.c,v 1.232.2.1 2007/10/12 22:29:36 riz Exp $ */
2
3 /*
4 * Copyright (c) 1997 Charles D. Cranor and Washington University.
5 * Copyright (c) 1991, 1993, The Regents of the University of California.
6 *
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * The Mach Operating System project at Carnegie-Mellon University.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by Charles D. Cranor,
23 * Washington University, the University of California, Berkeley and
24 * its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94
42 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp
43 *
44 *
45 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
46 * All rights reserved.
47 *
48 * Permission to use, copy, modify and distribute this software and
49 * its documentation is hereby granted, provided that both the copyright
50 * notice and this permission notice appear in all copies of the
51 * software, derivative works or modified versions, and any portions
52 * thereof, and that both notices appear in supporting documentation.
53 *
54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
57 *
58 * Carnegie Mellon requests users of this software to return to
59 *
60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
61 * School of Computer Science
62 * Carnegie Mellon University
63 * Pittsburgh PA 15213-3890
64 *
65 * any improvements or extensions that they make and grant Carnegie the
66 * rights to redistribute these changes.
67 */
68
69 /*
70 * uvm_map.c: uvm map operations
71 */
72
73 #include <sys/cdefs.h>
74 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.232.2.1 2007/10/12 22:29:36 riz Exp $");
75
76 #include "opt_ddb.h"
77 #include "opt_uvmhist.h"
78 #include "opt_uvm.h"
79 #include "opt_sysv.h"
80
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/mman.h>
84 #include <sys/proc.h>
85 #include <sys/malloc.h>
86 #include <sys/pool.h>
87 #include <sys/kernel.h>
88 #include <sys/mount.h>
89 #include <sys/vnode.h>
90
91 #ifdef SYSVSHM
92 #include <sys/shm.h>
93 #endif
94
95 #include <uvm/uvm.h>
96 #undef RB_AUGMENT
97 #define RB_AUGMENT(x) uvm_rb_augment(x)
98
99 #ifdef DDB
100 #include <uvm/uvm_ddb.h>
101 #endif
102
103 #if defined(UVMMAP_NOCOUNTERS)
104
105 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */
106 #define UVMMAP_EVCNT_INCR(ev) /* nothing */
107 #define UVMMAP_EVCNT_DECR(ev) /* nothing */
108
109 #else /* defined(UVMMAP_NOCOUNTERS) */
110
111 #include <sys/evcnt.h>
112 #define UVMMAP_EVCNT_DEFINE(name) \
113 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \
114 "uvmmap", #name); \
115 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name);
116 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++
117 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count--
118
119 #endif /* defined(UVMMAP_NOCOUNTERS) */
120
121 UVMMAP_EVCNT_DEFINE(ubackmerge)
122 UVMMAP_EVCNT_DEFINE(uforwmerge)
123 UVMMAP_EVCNT_DEFINE(ubimerge)
124 UVMMAP_EVCNT_DEFINE(unomerge)
125 UVMMAP_EVCNT_DEFINE(kbackmerge)
126 UVMMAP_EVCNT_DEFINE(kforwmerge)
127 UVMMAP_EVCNT_DEFINE(kbimerge)
128 UVMMAP_EVCNT_DEFINE(knomerge)
129 UVMMAP_EVCNT_DEFINE(map_call)
130 UVMMAP_EVCNT_DEFINE(mlk_call)
131 UVMMAP_EVCNT_DEFINE(mlk_hint)
132
133 UVMMAP_EVCNT_DEFINE(uke_alloc)
134 UVMMAP_EVCNT_DEFINE(uke_free)
135 UVMMAP_EVCNT_DEFINE(ukh_alloc)
136 UVMMAP_EVCNT_DEFINE(ukh_free)
137
138 const char vmmapbsy[] = "vmmapbsy";
139
140 /*
141 * pool for vmspace structures.
142 */
143
144 POOL_INIT(uvm_vmspace_pool, sizeof(struct vmspace), 0, 0, 0, "vmsppl",
145 &pool_allocator_nointr);
146
147 /*
148 * pool for dynamically-allocated map entries.
149 */
150
151 POOL_INIT(uvm_map_entry_pool, sizeof(struct vm_map_entry), 0, 0, 0, "vmmpepl",
152 &pool_allocator_nointr);
153
154 MALLOC_DEFINE(M_VMMAP, "VM map", "VM map structures");
155 MALLOC_DEFINE(M_VMPMAP, "VM pmap", "VM pmap");
156
157 #ifdef PMAP_GROWKERNEL
158 /*
159 * This global represents the end of the kernel virtual address
160 * space. If we want to exceed this, we must grow the kernel
161 * virtual address space dynamically.
162 *
163 * Note, this variable is locked by kernel_map's lock.
164 */
165 vaddr_t uvm_maxkaddr;
166 #endif
167
168 /*
169 * macros
170 */
171
172 /*
173 * VM_MAP_USE_KMAPENT: determine if uvm_kmapent_alloc/free is used
174 * for the vm_map.
175 */
176 extern struct vm_map *pager_map; /* XXX */
177 #define VM_MAP_USE_KMAPENT_FLAGS(flags) \
178 (((flags) & VM_MAP_INTRSAFE) != 0)
179 #define VM_MAP_USE_KMAPENT(map) \
180 (VM_MAP_USE_KMAPENT_FLAGS((map)->flags) || (map) == kernel_map)
181
182 /*
183 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging
184 */
185
186 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \
187 prot, maxprot, inh, adv, wire) \
188 ((ent)->etype == (type) && \
189 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE | UVM_MAP_QUANTUM)) \
190 == 0 && \
191 (ent)->object.uvm_obj == (uobj) && \
192 (ent)->protection == (prot) && \
193 (ent)->max_protection == (maxprot) && \
194 (ent)->inheritance == (inh) && \
195 (ent)->advice == (adv) && \
196 (ent)->wired_count == (wire))
197
198 /*
199 * uvm_map_entry_link: insert entry into a map
200 *
201 * => map must be locked
202 */
203 #define uvm_map_entry_link(map, after_where, entry) do { \
204 uvm_mapent_check(entry); \
205 (map)->nentries++; \
206 (entry)->prev = (after_where); \
207 (entry)->next = (after_where)->next; \
208 (entry)->prev->next = (entry); \
209 (entry)->next->prev = (entry); \
210 uvm_rb_insert((map), (entry)); \
211 } while (/*CONSTCOND*/ 0)
212
213 /*
214 * uvm_map_entry_unlink: remove entry from a map
215 *
216 * => map must be locked
217 */
218 #define uvm_map_entry_unlink(map, entry) do { \
219 KASSERT((entry) != (map)->first_free); \
220 KASSERT((entry) != (map)->hint); \
221 uvm_mapent_check(entry); \
222 (map)->nentries--; \
223 (entry)->next->prev = (entry)->prev; \
224 (entry)->prev->next = (entry)->next; \
225 uvm_rb_remove((map), (entry)); \
226 } while (/*CONSTCOND*/ 0)
227
228 /*
229 * SAVE_HINT: saves the specified entry as the hint for future lookups.
230 *
231 * => map need not be locked (protected by hint_lock).
232 */
233 #define SAVE_HINT(map,check,value) do { \
234 simple_lock(&(map)->hint_lock); \
235 if ((map)->hint == (check)) \
236 (map)->hint = (value); \
237 simple_unlock(&(map)->hint_lock); \
238 } while (/*CONSTCOND*/ 0)
239
240 /*
241 * clear_hints: ensure that hints don't point to the entry.
242 *
243 * => map must be write-locked.
244 */
245 static void
246 clear_hints(struct vm_map *map, struct vm_map_entry *ent)
247 {
248
249 SAVE_HINT(map, ent, ent->prev);
250 if (map->first_free == ent) {
251 map->first_free = ent->prev;
252 }
253 }
254
255 /*
256 * VM_MAP_RANGE_CHECK: check and correct range
257 *
258 * => map must at least be read locked
259 */
260
261 #define VM_MAP_RANGE_CHECK(map, start, end) do { \
262 if (start < vm_map_min(map)) \
263 start = vm_map_min(map); \
264 if (end > vm_map_max(map)) \
265 end = vm_map_max(map); \
266 if (start > end) \
267 start = end; \
268 } while (/*CONSTCOND*/ 0)
269
270 /*
271 * local prototypes
272 */
273
274 static struct vm_map_entry *
275 uvm_mapent_alloc(struct vm_map *, int);
276 static struct vm_map_entry *
277 uvm_mapent_alloc_split(struct vm_map *,
278 const struct vm_map_entry *, int,
279 struct uvm_mapent_reservation *);
280 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *);
281 static void uvm_mapent_free(struct vm_map_entry *);
282 #if defined(DEBUG)
283 static void _uvm_mapent_check(const struct vm_map_entry *, const char *,
284 int);
285 #define uvm_mapent_check(map) _uvm_mapent_check(map, __FILE__, __LINE__)
286 #else /* defined(DEBUG) */
287 #define uvm_mapent_check(e) /* nothing */
288 #endif /* defined(DEBUG) */
289 static struct vm_map_entry *
290 uvm_kmapent_alloc(struct vm_map *, int);
291 static void uvm_kmapent_free(struct vm_map_entry *);
292 static vsize_t uvm_kmapent_overhead(vsize_t);
293
294 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *);
295 static void uvm_map_reference_amap(struct vm_map_entry *, int);
296 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int,
297 struct vm_map_entry *);
298 static void uvm_map_unreference_amap(struct vm_map_entry *, int);
299
300 int _uvm_map_sanity(struct vm_map *);
301 int _uvm_tree_sanity(struct vm_map *);
302 static vsize_t uvm_rb_subtree_space(const struct vm_map_entry *);
303
304 static inline int
305 uvm_compare(const struct vm_map_entry *a, const struct vm_map_entry *b)
306 {
307
308 if (a->start < b->start)
309 return (-1);
310 else if (a->start > b->start)
311 return (1);
312
313 return (0);
314 }
315
316 static inline void
317 uvm_rb_augment(struct vm_map_entry *entry)
318 {
319
320 entry->space = uvm_rb_subtree_space(entry);
321 }
322
323 RB_PROTOTYPE(uvm_tree, vm_map_entry, rb_entry, uvm_compare);
324
325 RB_GENERATE(uvm_tree, vm_map_entry, rb_entry, uvm_compare);
326
327 static inline vsize_t
328 uvm_rb_space(const struct vm_map *map, const struct vm_map_entry *entry)
329 {
330 /* XXX map is not used */
331
332 KASSERT(entry->next != NULL);
333 return entry->next->start - entry->end;
334 }
335
336 static vsize_t
337 uvm_rb_subtree_space(const struct vm_map_entry *entry)
338 {
339 vaddr_t space, tmp;
340
341 space = entry->ownspace;
342 if (RB_LEFT(entry, rb_entry)) {
343 tmp = RB_LEFT(entry, rb_entry)->space;
344 if (tmp > space)
345 space = tmp;
346 }
347
348 if (RB_RIGHT(entry, rb_entry)) {
349 tmp = RB_RIGHT(entry, rb_entry)->space;
350 if (tmp > space)
351 space = tmp;
352 }
353
354 return (space);
355 }
356
357 static inline void
358 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry)
359 {
360 /* We need to traverse to the very top */
361 do {
362 entry->ownspace = uvm_rb_space(map, entry);
363 entry->space = uvm_rb_subtree_space(entry);
364 } while ((entry = RB_PARENT(entry, rb_entry)) != NULL);
365 }
366
367 static void
368 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry)
369 {
370 vaddr_t space = uvm_rb_space(map, entry);
371 struct vm_map_entry *tmp;
372
373 entry->ownspace = entry->space = space;
374 tmp = RB_INSERT(uvm_tree, &(map)->rbhead, entry);
375 #ifdef DIAGNOSTIC
376 if (tmp != NULL)
377 panic("uvm_rb_insert: duplicate entry?");
378 #endif
379 uvm_rb_fixup(map, entry);
380 if (entry->prev != &map->header)
381 uvm_rb_fixup(map, entry->prev);
382 }
383
384 static void
385 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry)
386 {
387 struct vm_map_entry *parent;
388
389 parent = RB_PARENT(entry, rb_entry);
390 RB_REMOVE(uvm_tree, &(map)->rbhead, entry);
391 if (entry->prev != &map->header)
392 uvm_rb_fixup(map, entry->prev);
393 if (parent)
394 uvm_rb_fixup(map, parent);
395 }
396
397 #if defined(DEBUG)
398 int uvm_debug_check_map = 0;
399 int uvm_debug_check_rbtree = 0;
400 #define uvm_map_check(map, name) \
401 _uvm_map_check((map), (name), __FILE__, __LINE__)
402 static void
403 _uvm_map_check(struct vm_map *map, const char *name,
404 const char *file, int line)
405 {
406
407 if ((uvm_debug_check_map && _uvm_map_sanity(map)) ||
408 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) {
409 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)",
410 name, map, file, line);
411 }
412 }
413 #else /* defined(DEBUG) */
414 #define uvm_map_check(map, name) /* nothing */
415 #endif /* defined(DEBUG) */
416
417 #if defined(DEBUG) || defined(DDB)
418 int
419 _uvm_map_sanity(struct vm_map *map)
420 {
421 boolean_t first_free_found = FALSE;
422 boolean_t hint_found = FALSE;
423 const struct vm_map_entry *e;
424
425 e = &map->header;
426 for (;;) {
427 if (map->first_free == e) {
428 first_free_found = TRUE;
429 } else if (!first_free_found && e->next->start > e->end) {
430 printf("first_free %p should be %p\n",
431 map->first_free, e);
432 return -1;
433 }
434 if (map->hint == e) {
435 hint_found = TRUE;
436 }
437
438 e = e->next;
439 if (e == &map->header) {
440 break;
441 }
442 }
443 if (!first_free_found) {
444 printf("stale first_free\n");
445 return -1;
446 }
447 if (!hint_found) {
448 printf("stale hint\n");
449 return -1;
450 }
451 return 0;
452 }
453
454 int
455 _uvm_tree_sanity(struct vm_map *map)
456 {
457 struct vm_map_entry *tmp, *trtmp;
458 int n = 0, i = 1;
459
460 RB_FOREACH(tmp, uvm_tree, &map->rbhead) {
461 if (tmp->ownspace != uvm_rb_space(map, tmp)) {
462 printf("%d/%d ownspace %lx != %lx %s\n",
463 n + 1, map->nentries,
464 (ulong)tmp->ownspace, (ulong)uvm_rb_space(map, tmp),
465 tmp->next == &map->header ? "(last)" : "");
466 goto error;
467 }
468 }
469 trtmp = NULL;
470 RB_FOREACH(tmp, uvm_tree, &map->rbhead) {
471 if (tmp->space != uvm_rb_subtree_space(tmp)) {
472 printf("space %lx != %lx\n",
473 (ulong)tmp->space,
474 (ulong)uvm_rb_subtree_space(tmp));
475 goto error;
476 }
477 if (trtmp != NULL && trtmp->start >= tmp->start) {
478 printf("corrupt: 0x%lx >= 0x%lx\n",
479 trtmp->start, tmp->start);
480 goto error;
481 }
482 n++;
483
484 trtmp = tmp;
485 }
486
487 if (n != map->nentries) {
488 printf("nentries: %d vs %d\n", n, map->nentries);
489 goto error;
490 }
491
492 for (tmp = map->header.next; tmp && tmp != &map->header;
493 tmp = tmp->next, i++) {
494 trtmp = RB_FIND(uvm_tree, &map->rbhead, tmp);
495 if (trtmp != tmp) {
496 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp,
497 RB_PARENT(tmp, rb_entry));
498 goto error;
499 }
500 }
501
502 return (0);
503 error:
504 return (-1);
505 }
506 #endif /* defined(DEBUG) || defined(DDB) */
507
508 #ifdef DIAGNOSTIC
509 static struct vm_map *uvm_kmapent_map(struct vm_map_entry *);
510 #endif
511
512 /*
513 * uvm_mapent_alloc: allocate a map entry
514 */
515
516 static struct vm_map_entry *
517 uvm_mapent_alloc(struct vm_map *map, int flags)
518 {
519 struct vm_map_entry *me;
520 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK;
521 UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist);
522
523 if (VM_MAP_USE_KMAPENT(map)) {
524 me = uvm_kmapent_alloc(map, flags);
525 } else {
526 me = pool_get(&uvm_map_entry_pool, pflags);
527 if (__predict_false(me == NULL))
528 return NULL;
529 me->flags = 0;
530 }
531
532 UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", me,
533 ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map), 0, 0);
534 return (me);
535 }
536
537 /*
538 * uvm_mapent_alloc_split: allocate a map entry for clipping.
539 */
540
541 static struct vm_map_entry *
542 uvm_mapent_alloc_split(struct vm_map *map,
543 const struct vm_map_entry *old_entry, int flags,
544 struct uvm_mapent_reservation *umr)
545 {
546 struct vm_map_entry *me;
547
548 KASSERT(!VM_MAP_USE_KMAPENT(map) ||
549 (old_entry->flags & UVM_MAP_QUANTUM) || !UMR_EMPTY(umr));
550
551 if (old_entry->flags & UVM_MAP_QUANTUM) {
552 int s;
553 struct vm_map_kernel *vmk = vm_map_to_kernel(map);
554
555 s = splvm();
556 simple_lock(&uvm.kentry_lock);
557 me = vmk->vmk_merged_entries;
558 KASSERT(me);
559 vmk->vmk_merged_entries = me->next;
560 simple_unlock(&uvm.kentry_lock);
561 splx(s);
562 KASSERT(me->flags & UVM_MAP_QUANTUM);
563 } else {
564 me = uvm_mapent_alloc(map, flags);
565 }
566
567 return me;
568 }
569
570 /*
571 * uvm_mapent_free: free map entry
572 */
573
574 static void
575 uvm_mapent_free(struct vm_map_entry *me)
576 {
577 UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist);
578
579 UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]",
580 me, me->flags, 0, 0);
581 if (me->flags & UVM_MAP_KERNEL) {
582 uvm_kmapent_free(me);
583 } else {
584 pool_put(&uvm_map_entry_pool, me);
585 }
586 }
587
588 /*
589 * uvm_mapent_free_merged: free merged map entry
590 *
591 * => keep the entry if needed.
592 * => caller shouldn't hold map locked if VM_MAP_USE_KMAPENT(map) is true.
593 */
594
595 static void
596 uvm_mapent_free_merged(struct vm_map *map, struct vm_map_entry *me)
597 {
598
599 KASSERT(!(me->flags & UVM_MAP_KERNEL) || uvm_kmapent_map(me) == map);
600
601 if (me->flags & UVM_MAP_QUANTUM) {
602 /*
603 * keep this entry for later splitting.
604 */
605 struct vm_map_kernel *vmk;
606 int s;
607
608 KASSERT(VM_MAP_IS_KERNEL(map));
609 KASSERT(!VM_MAP_USE_KMAPENT(map) ||
610 (me->flags & UVM_MAP_KERNEL));
611
612 vmk = vm_map_to_kernel(map);
613 s = splvm();
614 simple_lock(&uvm.kentry_lock);
615 me->next = vmk->vmk_merged_entries;
616 vmk->vmk_merged_entries = me;
617 simple_unlock(&uvm.kentry_lock);
618 splx(s);
619 } else {
620 uvm_mapent_free(me);
621 }
622 }
623
624 /*
625 * uvm_mapent_copy: copy a map entry, preserving flags
626 */
627
628 static inline void
629 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst)
630 {
631
632 memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) -
633 ((char *)src));
634 }
635
636 /*
637 * uvm_mapent_overhead: calculate maximum kva overhead necessary for
638 * map entries.
639 *
640 * => size and flags are the same as uvm_km_suballoc's ones.
641 */
642
643 vsize_t
644 uvm_mapent_overhead(vsize_t size, int flags)
645 {
646
647 if (VM_MAP_USE_KMAPENT_FLAGS(flags)) {
648 return uvm_kmapent_overhead(size);
649 }
650 return 0;
651 }
652
653 #if defined(DEBUG)
654 static void
655 _uvm_mapent_check(const struct vm_map_entry *entry, const char *file, int line)
656 {
657
658 if (entry->start >= entry->end) {
659 goto bad;
660 }
661 if (UVM_ET_ISOBJ(entry)) {
662 if (entry->object.uvm_obj == NULL) {
663 goto bad;
664 }
665 } else if (UVM_ET_ISSUBMAP(entry)) {
666 if (entry->object.sub_map == NULL) {
667 goto bad;
668 }
669 } else {
670 if (entry->object.uvm_obj != NULL ||
671 entry->object.sub_map != NULL) {
672 goto bad;
673 }
674 }
675 if (!UVM_ET_ISOBJ(entry)) {
676 if (entry->offset != 0) {
677 goto bad;
678 }
679 }
680
681 return;
682
683 bad:
684 panic("%s: bad entry %p (%s:%d)", __func__, entry, file, line);
685 }
686 #endif /* defined(DEBUG) */
687
688 /*
689 * uvm_map_entry_unwire: unwire a map entry
690 *
691 * => map should be locked by caller
692 */
693
694 static inline void
695 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry)
696 {
697
698 entry->wired_count = 0;
699 uvm_fault_unwire_locked(map, entry->start, entry->end);
700 }
701
702
703 /*
704 * wrapper for calling amap_ref()
705 */
706 static inline void
707 uvm_map_reference_amap(struct vm_map_entry *entry, int flags)
708 {
709
710 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff,
711 (entry->end - entry->start) >> PAGE_SHIFT, flags);
712 }
713
714
715 /*
716 * wrapper for calling amap_unref()
717 */
718 static inline void
719 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags)
720 {
721
722 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff,
723 (entry->end - entry->start) >> PAGE_SHIFT, flags);
724 }
725
726
727 /*
728 * uvm_map_init: init mapping system at boot time. note that we allocate
729 * and init the static pool of struct vm_map_entry *'s for the kernel here.
730 */
731
732 void
733 uvm_map_init(void)
734 {
735 #if defined(UVMHIST)
736 static struct uvm_history_ent maphistbuf[100];
737 static struct uvm_history_ent pdhistbuf[100];
738 #endif
739
740 /*
741 * first, init logging system.
742 */
743
744 UVMHIST_FUNC("uvm_map_init");
745 UVMHIST_INIT_STATIC(maphist, maphistbuf);
746 UVMHIST_INIT_STATIC(pdhist, pdhistbuf);
747 UVMHIST_CALLED(maphist);
748 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0);
749
750 /*
751 * initialize the global lock for kernel map entry.
752 *
753 * XXX is it worth to have per-map lock instead?
754 */
755
756 simple_lock_init(&uvm.kentry_lock);
757 }
758
759 /*
760 * clippers
761 */
762
763 /*
764 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy.
765 */
766
767 static void
768 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2,
769 vaddr_t splitat)
770 {
771 vaddr_t adj;
772
773 KASSERT(entry1->start < splitat);
774 KASSERT(splitat < entry1->end);
775
776 adj = splitat - entry1->start;
777 entry1->end = entry2->start = splitat;
778
779 if (entry1->aref.ar_amap) {
780 amap_splitref(&entry1->aref, &entry2->aref, adj);
781 }
782 if (UVM_ET_ISSUBMAP(entry1)) {
783 /* ... unlikely to happen, but play it safe */
784 uvm_map_reference(entry1->object.sub_map);
785 } else if (UVM_ET_ISOBJ(entry1)) {
786 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */
787 entry2->offset += adj;
788 if (entry1->object.uvm_obj->pgops &&
789 entry1->object.uvm_obj->pgops->pgo_reference)
790 entry1->object.uvm_obj->pgops->pgo_reference(
791 entry1->object.uvm_obj);
792 }
793 }
794
795 /*
796 * uvm_map_clip_start: ensure that the entry begins at or after
797 * the starting address, if it doesn't we split the entry.
798 *
799 * => caller should use UVM_MAP_CLIP_START macro rather than calling
800 * this directly
801 * => map must be locked by caller
802 */
803
804 void
805 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry,
806 vaddr_t start, struct uvm_mapent_reservation *umr)
807 {
808 struct vm_map_entry *new_entry;
809
810 /* uvm_map_simplify_entry(map, entry); */ /* XXX */
811
812 uvm_map_check(map, "clip_start entry");
813 uvm_mapent_check(entry);
814
815 /*
816 * Split off the front portion. note that we must insert the new
817 * entry BEFORE this one, so that this entry has the specified
818 * starting address.
819 */
820 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr);
821 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
822 uvm_mapent_splitadj(new_entry, entry, start);
823 uvm_map_entry_link(map, entry->prev, new_entry);
824
825 uvm_map_check(map, "clip_start leave");
826 }
827
828 /*
829 * uvm_map_clip_end: ensure that the entry ends at or before
830 * the ending address, if it does't we split the reference
831 *
832 * => caller should use UVM_MAP_CLIP_END macro rather than calling
833 * this directly
834 * => map must be locked by caller
835 */
836
837 void
838 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end,
839 struct uvm_mapent_reservation *umr)
840 {
841 struct vm_map_entry *new_entry;
842
843 uvm_map_check(map, "clip_end entry");
844 uvm_mapent_check(entry);
845
846 /*
847 * Create a new entry and insert it
848 * AFTER the specified entry
849 */
850 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr);
851 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
852 uvm_mapent_splitadj(entry, new_entry, end);
853 uvm_map_entry_link(map, entry, new_entry);
854
855 uvm_map_check(map, "clip_end leave");
856 }
857
858 static void
859 vm_map_drain(struct vm_map *map, uvm_flag_t flags)
860 {
861
862 if (!VM_MAP_IS_KERNEL(map)) {
863 return;
864 }
865
866 uvm_km_va_drain(map, flags);
867 }
868
869 /*
870 * M A P - m a i n e n t r y p o i n t
871 */
872 /*
873 * uvm_map: establish a valid mapping in a map
874 *
875 * => assume startp is page aligned.
876 * => assume size is a multiple of PAGE_SIZE.
877 * => assume sys_mmap provides enough of a "hint" to have us skip
878 * over text/data/bss area.
879 * => map must be unlocked (we will lock it)
880 * => <uobj,uoffset> value meanings (4 cases):
881 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER
882 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER
883 * [3] <uobj,uoffset> == normal mapping
884 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA
885 *
886 * case [4] is for kernel mappings where we don't know the offset until
887 * we've found a virtual address. note that kernel object offsets are
888 * always relative to vm_map_min(kernel_map).
889 *
890 * => if `align' is non-zero, we align the virtual address to the specified
891 * alignment.
892 * this is provided as a mechanism for large pages.
893 *
894 * => XXXCDC: need way to map in external amap?
895 */
896
897 int
898 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size,
899 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags)
900 {
901 struct uvm_map_args args;
902 struct vm_map_entry *new_entry;
903 int error;
904
905 KASSERT((flags & UVM_FLAG_QUANTUM) == 0 || VM_MAP_IS_KERNEL(map));
906 KASSERT((size & PAGE_MASK) == 0);
907
908 /*
909 * for pager_map, allocate the new entry first to avoid sleeping
910 * for memory while we have the map locked.
911 *
912 * besides, because we allocates entries for in-kernel maps
913 * a bit differently (cf. uvm_kmapent_alloc/free), we need to
914 * allocate them before locking the map.
915 */
916
917 new_entry = NULL;
918 if (VM_MAP_USE_KMAPENT(map) || (flags & UVM_FLAG_QUANTUM) ||
919 map == pager_map) {
920 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT));
921 if (__predict_false(new_entry == NULL))
922 return ENOMEM;
923 if (flags & UVM_FLAG_QUANTUM)
924 new_entry->flags |= UVM_MAP_QUANTUM;
925 }
926 if (map == pager_map)
927 flags |= UVM_FLAG_NOMERGE;
928
929 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align,
930 flags, &args);
931 if (!error) {
932 error = uvm_map_enter(map, &args, new_entry);
933 *startp = args.uma_start;
934 } else if (new_entry) {
935 uvm_mapent_free(new_entry);
936 }
937
938 #if defined(DEBUG)
939 if (!error && VM_MAP_IS_KERNEL(map)) {
940 uvm_km_check_empty(*startp, *startp + size,
941 (map->flags & VM_MAP_INTRSAFE) != 0);
942 }
943 #endif /* defined(DEBUG) */
944
945 return error;
946 }
947
948 int
949 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size,
950 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags,
951 struct uvm_map_args *args)
952 {
953 struct vm_map_entry *prev_entry;
954 vm_prot_t prot = UVM_PROTECTION(flags);
955 vm_prot_t maxprot = UVM_MAXPROTECTION(flags);
956
957 UVMHIST_FUNC("uvm_map_prepare");
958 UVMHIST_CALLED(maphist);
959
960 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)",
961 map, start, size, flags);
962 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0);
963
964 /*
965 * detect a popular device driver bug.
966 */
967
968 KASSERT(doing_shutdown || curlwp != NULL ||
969 (map->flags & VM_MAP_INTRSAFE));
970
971 /*
972 * zero-sized mapping doesn't make any sense.
973 */
974 KASSERT(size > 0);
975
976 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0);
977
978 uvm_map_check(map, "map entry");
979
980 /*
981 * check sanity of protection code
982 */
983
984 if ((prot & maxprot) != prot) {
985 UVMHIST_LOG(maphist, "<- prot. failure: prot=0x%x, max=0x%x",
986 prot, maxprot,0,0);
987 return EACCES;
988 }
989
990 /*
991 * figure out where to put new VM range
992 */
993
994 retry:
995 if (vm_map_lock_try(map) == FALSE) {
996 if (flags & UVM_FLAG_TRYLOCK) {
997 return EAGAIN;
998 }
999 vm_map_lock(map); /* could sleep here */
1000 }
1001 prev_entry = uvm_map_findspace(map, start, size, &start,
1002 uobj, uoffset, align, flags);
1003 if (prev_entry == NULL) {
1004 unsigned int timestamp;
1005
1006 timestamp = map->timestamp;
1007 UVMHIST_LOG(maphist,"waiting va timestamp=0x%x",
1008 timestamp,0,0,0);
1009 simple_lock(&map->flags_lock);
1010 map->flags |= VM_MAP_WANTVA;
1011 simple_unlock(&map->flags_lock);
1012 vm_map_unlock(map);
1013
1014 /*
1015 * try to reclaim kva and wait until someone does unmap.
1016 * XXX fragile locking
1017 */
1018
1019 vm_map_drain(map, flags);
1020
1021 simple_lock(&map->flags_lock);
1022 while ((map->flags & VM_MAP_WANTVA) != 0 &&
1023 map->timestamp == timestamp) {
1024 if ((flags & UVM_FLAG_WAITVA) == 0) {
1025 simple_unlock(&map->flags_lock);
1026 UVMHIST_LOG(maphist,
1027 "<- uvm_map_findspace failed!", 0,0,0,0);
1028 return ENOMEM;
1029 } else {
1030 ltsleep(&map->header, PVM, "vmmapva", 0,
1031 &map->flags_lock);
1032 }
1033 }
1034 simple_unlock(&map->flags_lock);
1035 goto retry;
1036 }
1037
1038 #ifdef PMAP_GROWKERNEL
1039 /*
1040 * If the kernel pmap can't map the requested space,
1041 * then allocate more resources for it.
1042 */
1043 if (map == kernel_map && uvm_maxkaddr < (start + size))
1044 uvm_maxkaddr = pmap_growkernel(start + size);
1045 #endif
1046
1047 UVMMAP_EVCNT_INCR(map_call);
1048
1049 /*
1050 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER
1051 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in
1052 * either case we want to zero it before storing it in the map entry
1053 * (because it looks strange and confusing when debugging...)
1054 *
1055 * if uobj is not null
1056 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping
1057 * and we do not need to change uoffset.
1058 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset
1059 * now (based on the starting address of the map). this case is
1060 * for kernel object mappings where we don't know the offset until
1061 * the virtual address is found (with uvm_map_findspace). the
1062 * offset is the distance we are from the start of the map.
1063 */
1064
1065 if (uobj == NULL) {
1066 uoffset = 0;
1067 } else {
1068 if (uoffset == UVM_UNKNOWN_OFFSET) {
1069 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj));
1070 uoffset = start - vm_map_min(kernel_map);
1071 }
1072 }
1073
1074 args->uma_flags = flags;
1075 args->uma_prev = prev_entry;
1076 args->uma_start = start;
1077 args->uma_size = size;
1078 args->uma_uobj = uobj;
1079 args->uma_uoffset = uoffset;
1080
1081 return 0;
1082 }
1083
1084 int
1085 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args,
1086 struct vm_map_entry *new_entry)
1087 {
1088 struct vm_map_entry *prev_entry = args->uma_prev;
1089 struct vm_map_entry *dead = NULL;
1090
1091 const uvm_flag_t flags = args->uma_flags;
1092 const vm_prot_t prot = UVM_PROTECTION(flags);
1093 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags);
1094 const vm_inherit_t inherit = UVM_INHERIT(flags);
1095 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ?
1096 AMAP_EXTEND_NOWAIT : 0;
1097 const int advice = UVM_ADVICE(flags);
1098 const int meflagval = (flags & UVM_FLAG_QUANTUM) ?
1099 UVM_MAP_QUANTUM : 0;
1100
1101 vaddr_t start = args->uma_start;
1102 vsize_t size = args->uma_size;
1103 struct uvm_object *uobj = args->uma_uobj;
1104 voff_t uoffset = args->uma_uoffset;
1105
1106 const int kmap = (vm_map_pmap(map) == pmap_kernel());
1107 int merged = 0;
1108 int error;
1109 int newetype;
1110
1111 UVMHIST_FUNC("uvm_map_enter");
1112 UVMHIST_CALLED(maphist);
1113
1114 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)",
1115 map, start, size, flags);
1116 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0);
1117
1118 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */
1119
1120 if (flags & UVM_FLAG_QUANTUM) {
1121 KASSERT(new_entry);
1122 KASSERT(new_entry->flags & UVM_MAP_QUANTUM);
1123 }
1124
1125 if (uobj)
1126 newetype = UVM_ET_OBJ;
1127 else
1128 newetype = 0;
1129
1130 if (flags & UVM_FLAG_COPYONW) {
1131 newetype |= UVM_ET_COPYONWRITE;
1132 if ((flags & UVM_FLAG_OVERLAY) == 0)
1133 newetype |= UVM_ET_NEEDSCOPY;
1134 }
1135
1136 /*
1137 * try and insert in map by extending previous entry, if possible.
1138 * XXX: we don't try and pull back the next entry. might be useful
1139 * for a stack, but we are currently allocating our stack in advance.
1140 */
1141
1142 if (flags & UVM_FLAG_NOMERGE)
1143 goto nomerge;
1144
1145 if (prev_entry->end == start &&
1146 prev_entry != &map->header &&
1147 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, meflagval,
1148 prot, maxprot, inherit, advice, 0)) {
1149
1150 if (uobj && prev_entry->offset +
1151 (prev_entry->end - prev_entry->start) != uoffset)
1152 goto forwardmerge;
1153
1154 /*
1155 * can't extend a shared amap. note: no need to lock amap to
1156 * look at refs since we don't care about its exact value.
1157 * if it is one (i.e. we have only reference) it will stay there
1158 */
1159
1160 if (prev_entry->aref.ar_amap &&
1161 amap_refs(prev_entry->aref.ar_amap) != 1) {
1162 goto forwardmerge;
1163 }
1164
1165 if (prev_entry->aref.ar_amap) {
1166 error = amap_extend(prev_entry, size,
1167 amapwaitflag | AMAP_EXTEND_FORWARDS);
1168 if (error)
1169 goto nomerge;
1170 }
1171
1172 if (kmap)
1173 UVMMAP_EVCNT_INCR(kbackmerge);
1174 else
1175 UVMMAP_EVCNT_INCR(ubackmerge);
1176 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0);
1177
1178 /*
1179 * drop our reference to uobj since we are extending a reference
1180 * that we already have (the ref count can not drop to zero).
1181 */
1182
1183 if (uobj && uobj->pgops->pgo_detach)
1184 uobj->pgops->pgo_detach(uobj);
1185
1186 prev_entry->end += size;
1187 uvm_rb_fixup(map, prev_entry);
1188
1189 uvm_map_check(map, "map backmerged");
1190
1191 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0);
1192 merged++;
1193 }
1194
1195 forwardmerge:
1196 if (prev_entry->next->start == (start + size) &&
1197 prev_entry->next != &map->header &&
1198 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, meflagval,
1199 prot, maxprot, inherit, advice, 0)) {
1200
1201 if (uobj && prev_entry->next->offset != uoffset + size)
1202 goto nomerge;
1203
1204 /*
1205 * can't extend a shared amap. note: no need to lock amap to
1206 * look at refs since we don't care about its exact value.
1207 * if it is one (i.e. we have only reference) it will stay there.
1208 *
1209 * note that we also can't merge two amaps, so if we
1210 * merged with the previous entry which has an amap,
1211 * and the next entry also has an amap, we give up.
1212 *
1213 * Interesting cases:
1214 * amap, new, amap -> give up second merge (single fwd extend)
1215 * amap, new, none -> double forward extend (extend again here)
1216 * none, new, amap -> double backward extend (done here)
1217 * uobj, new, amap -> single backward extend (done here)
1218 *
1219 * XXX should we attempt to deal with someone refilling
1220 * the deallocated region between two entries that are
1221 * backed by the same amap (ie, arefs is 2, "prev" and
1222 * "next" refer to it, and adding this allocation will
1223 * close the hole, thus restoring arefs to 1 and
1224 * deallocating the "next" vm_map_entry)? -- @@@
1225 */
1226
1227 if (prev_entry->next->aref.ar_amap &&
1228 (amap_refs(prev_entry->next->aref.ar_amap) != 1 ||
1229 (merged && prev_entry->aref.ar_amap))) {
1230 goto nomerge;
1231 }
1232
1233 if (merged) {
1234 /*
1235 * Try to extend the amap of the previous entry to
1236 * cover the next entry as well. If it doesn't work
1237 * just skip on, don't actually give up, since we've
1238 * already completed the back merge.
1239 */
1240 if (prev_entry->aref.ar_amap) {
1241 if (amap_extend(prev_entry,
1242 prev_entry->next->end -
1243 prev_entry->next->start,
1244 amapwaitflag | AMAP_EXTEND_FORWARDS))
1245 goto nomerge;
1246 }
1247
1248 /*
1249 * Try to extend the amap of the *next* entry
1250 * back to cover the new allocation *and* the
1251 * previous entry as well (the previous merge
1252 * didn't have an amap already otherwise we
1253 * wouldn't be checking here for an amap). If
1254 * it doesn't work just skip on, again, don't
1255 * actually give up, since we've already
1256 * completed the back merge.
1257 */
1258 else if (prev_entry->next->aref.ar_amap) {
1259 if (amap_extend(prev_entry->next,
1260 prev_entry->end -
1261 prev_entry->start,
1262 amapwaitflag | AMAP_EXTEND_BACKWARDS))
1263 goto nomerge;
1264 }
1265 } else {
1266 /*
1267 * Pull the next entry's amap backwards to cover this
1268 * new allocation.
1269 */
1270 if (prev_entry->next->aref.ar_amap) {
1271 error = amap_extend(prev_entry->next, size,
1272 amapwaitflag | AMAP_EXTEND_BACKWARDS);
1273 if (error)
1274 goto nomerge;
1275 }
1276 }
1277
1278 if (merged) {
1279 if (kmap) {
1280 UVMMAP_EVCNT_DECR(kbackmerge);
1281 UVMMAP_EVCNT_INCR(kbimerge);
1282 } else {
1283 UVMMAP_EVCNT_DECR(ubackmerge);
1284 UVMMAP_EVCNT_INCR(ubimerge);
1285 }
1286 } else {
1287 if (kmap)
1288 UVMMAP_EVCNT_INCR(kforwmerge);
1289 else
1290 UVMMAP_EVCNT_INCR(uforwmerge);
1291 }
1292 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0);
1293
1294 /*
1295 * drop our reference to uobj since we are extending a reference
1296 * that we already have (the ref count can not drop to zero).
1297 * (if merged, we've already detached)
1298 */
1299 if (uobj && uobj->pgops->pgo_detach && !merged)
1300 uobj->pgops->pgo_detach(uobj);
1301
1302 if (merged) {
1303 dead = prev_entry->next;
1304 prev_entry->end = dead->end;
1305 uvm_map_entry_unlink(map, dead);
1306 if (dead->aref.ar_amap != NULL) {
1307 prev_entry->aref = dead->aref;
1308 dead->aref.ar_amap = NULL;
1309 }
1310 } else {
1311 prev_entry->next->start -= size;
1312 if (prev_entry != &map->header)
1313 uvm_rb_fixup(map, prev_entry);
1314 if (uobj)
1315 prev_entry->next->offset = uoffset;
1316 }
1317
1318 uvm_map_check(map, "map forwardmerged");
1319
1320 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0);
1321 merged++;
1322 }
1323
1324 nomerge:
1325 if (!merged) {
1326 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0);
1327 if (kmap)
1328 UVMMAP_EVCNT_INCR(knomerge);
1329 else
1330 UVMMAP_EVCNT_INCR(unomerge);
1331
1332 /*
1333 * allocate new entry and link it in.
1334 */
1335
1336 if (new_entry == NULL) {
1337 new_entry = uvm_mapent_alloc(map,
1338 (flags & UVM_FLAG_NOWAIT));
1339 if (__predict_false(new_entry == NULL)) {
1340 error = ENOMEM;
1341 goto done;
1342 }
1343 }
1344 new_entry->start = start;
1345 new_entry->end = new_entry->start + size;
1346 new_entry->object.uvm_obj = uobj;
1347 new_entry->offset = uoffset;
1348
1349 new_entry->etype = newetype;
1350
1351 if (flags & UVM_FLAG_NOMERGE) {
1352 new_entry->flags |= UVM_MAP_NOMERGE;
1353 }
1354
1355 new_entry->protection = prot;
1356 new_entry->max_protection = maxprot;
1357 new_entry->inheritance = inherit;
1358 new_entry->wired_count = 0;
1359 new_entry->advice = advice;
1360 if (flags & UVM_FLAG_OVERLAY) {
1361
1362 /*
1363 * to_add: for BSS we overallocate a little since we
1364 * are likely to extend
1365 */
1366
1367 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ?
1368 UVM_AMAP_CHUNK << PAGE_SHIFT : 0;
1369 struct vm_amap *amap = amap_alloc(size, to_add,
1370 (flags & UVM_FLAG_NOWAIT));
1371 if (__predict_false(amap == NULL)) {
1372 error = ENOMEM;
1373 goto done;
1374 }
1375 new_entry->aref.ar_pageoff = 0;
1376 new_entry->aref.ar_amap = amap;
1377 } else {
1378 new_entry->aref.ar_pageoff = 0;
1379 new_entry->aref.ar_amap = NULL;
1380 }
1381 uvm_map_entry_link(map, prev_entry, new_entry);
1382
1383 /*
1384 * Update the free space hint
1385 */
1386
1387 if ((map->first_free == prev_entry) &&
1388 (prev_entry->end >= new_entry->start))
1389 map->first_free = new_entry;
1390
1391 new_entry = NULL;
1392 }
1393
1394 map->size += size;
1395
1396 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
1397
1398 error = 0;
1399 done:
1400 vm_map_unlock(map);
1401 if (new_entry) {
1402 if (error == 0) {
1403 KDASSERT(merged);
1404 uvm_mapent_free_merged(map, new_entry);
1405 } else {
1406 uvm_mapent_free(new_entry);
1407 }
1408 }
1409 if (dead) {
1410 KDASSERT(merged);
1411 uvm_mapent_free_merged(map, dead);
1412 }
1413 return error;
1414 }
1415
1416 /*
1417 * uvm_map_lookup_entry: find map entry at or before an address
1418 *
1419 * => map must at least be read-locked by caller
1420 * => entry is returned in "entry"
1421 * => return value is true if address is in the returned entry
1422 */
1423
1424 boolean_t
1425 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address,
1426 struct vm_map_entry **entry /* OUT */)
1427 {
1428 struct vm_map_entry *cur;
1429 boolean_t use_tree = FALSE;
1430 UVMHIST_FUNC("uvm_map_lookup_entry");
1431 UVMHIST_CALLED(maphist);
1432
1433 UVMHIST_LOG(maphist,"(map=0x%x,addr=0x%x,ent=0x%x)",
1434 map, address, entry, 0);
1435
1436 /*
1437 * start looking either from the head of the
1438 * list, or from the hint.
1439 */
1440
1441 simple_lock(&map->hint_lock);
1442 cur = map->hint;
1443 simple_unlock(&map->hint_lock);
1444
1445 if (cur == &map->header)
1446 cur = cur->next;
1447
1448 UVMMAP_EVCNT_INCR(mlk_call);
1449 if (address >= cur->start) {
1450
1451 /*
1452 * go from hint to end of list.
1453 *
1454 * but first, make a quick check to see if
1455 * we are already looking at the entry we
1456 * want (which is usually the case).
1457 * note also that we don't need to save the hint
1458 * here... it is the same hint (unless we are
1459 * at the header, in which case the hint didn't
1460 * buy us anything anyway).
1461 */
1462
1463 if (cur != &map->header && cur->end > address) {
1464 UVMMAP_EVCNT_INCR(mlk_hint);
1465 *entry = cur;
1466 UVMHIST_LOG(maphist,"<- got it via hint (0x%x)",
1467 cur, 0, 0, 0);
1468 uvm_mapent_check(*entry);
1469 return (TRUE);
1470 }
1471
1472 if (map->nentries > 30)
1473 use_tree = TRUE;
1474 } else {
1475
1476 /*
1477 * invalid hint. use tree.
1478 */
1479 use_tree = TRUE;
1480 }
1481
1482 uvm_map_check(map, __func__);
1483
1484 if (use_tree) {
1485 struct vm_map_entry *prev = &map->header;
1486 cur = RB_ROOT(&map->rbhead);
1487
1488 /*
1489 * Simple lookup in the tree. Happens when the hint is
1490 * invalid, or nentries reach a threshold.
1491 */
1492 while (cur) {
1493 if (address >= cur->start) {
1494 if (address < cur->end) {
1495 *entry = cur;
1496 goto got;
1497 }
1498 prev = cur;
1499 cur = RB_RIGHT(cur, rb_entry);
1500 } else
1501 cur = RB_LEFT(cur, rb_entry);
1502 }
1503 *entry = prev;
1504 goto failed;
1505 }
1506
1507 /*
1508 * search linearly
1509 */
1510
1511 while (cur != &map->header) {
1512 if (cur->end > address) {
1513 if (address >= cur->start) {
1514 /*
1515 * save this lookup for future
1516 * hints, and return
1517 */
1518
1519 *entry = cur;
1520 got:
1521 SAVE_HINT(map, map->hint, *entry);
1522 UVMHIST_LOG(maphist,"<- search got it (0x%x)",
1523 cur, 0, 0, 0);
1524 KDASSERT((*entry)->start <= address);
1525 KDASSERT(address < (*entry)->end);
1526 uvm_mapent_check(*entry);
1527 return (TRUE);
1528 }
1529 break;
1530 }
1531 cur = cur->next;
1532 }
1533 *entry = cur->prev;
1534 failed:
1535 SAVE_HINT(map, map->hint, *entry);
1536 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0);
1537 KDASSERT((*entry) == &map->header || (*entry)->end <= address);
1538 KDASSERT((*entry)->next == &map->header ||
1539 address < (*entry)->next->start);
1540 return (FALSE);
1541 }
1542
1543 /*
1544 * See if the range between start and start + length fits in the gap
1545 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't
1546 * fit, and -1 address wraps around.
1547 */
1548 static int
1549 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset,
1550 vsize_t align, int topdown, struct vm_map_entry *entry)
1551 {
1552 vaddr_t end;
1553
1554 #ifdef PMAP_PREFER
1555 /*
1556 * push start address forward as needed to avoid VAC alias problems.
1557 * we only do this if a valid offset is specified.
1558 */
1559
1560 if (uoffset != UVM_UNKNOWN_OFFSET)
1561 PMAP_PREFER(uoffset, start, length, topdown);
1562 #endif
1563 if (align != 0) {
1564 if ((*start & (align - 1)) != 0) {
1565 if (topdown)
1566 *start &= ~(align - 1);
1567 else
1568 *start = roundup(*start, align);
1569 }
1570 /*
1571 * XXX Should we PMAP_PREFER() here again?
1572 * eh...i think we're okay
1573 */
1574 }
1575
1576 /*
1577 * Find the end of the proposed new region. Be sure we didn't
1578 * wrap around the address; if so, we lose. Otherwise, if the
1579 * proposed new region fits before the next entry, we win.
1580 */
1581
1582 end = *start + length;
1583 if (end < *start)
1584 return (-1);
1585
1586 if (entry->next->start >= end && *start >= entry->end)
1587 return (1);
1588
1589 return (0);
1590 }
1591
1592 /*
1593 * uvm_map_findspace: find "length" sized space in "map".
1594 *
1595 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is
1596 * set in "flags" (in which case we insist on using "hint").
1597 * => "result" is VA returned
1598 * => uobj/uoffset are to be used to handle VAC alignment, if required
1599 * => if "align" is non-zero, we attempt to align to that value.
1600 * => caller must at least have read-locked map
1601 * => returns NULL on failure, or pointer to prev. map entry if success
1602 * => note this is a cross between the old vm_map_findspace and vm_map_find
1603 */
1604
1605 struct vm_map_entry *
1606 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length,
1607 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset,
1608 vsize_t align, int flags)
1609 {
1610 struct vm_map_entry *entry;
1611 struct vm_map_entry *child, *prev, *tmp;
1612 vaddr_t orig_hint;
1613 const int topdown = map->flags & VM_MAP_TOPDOWN;
1614 UVMHIST_FUNC("uvm_map_findspace");
1615 UVMHIST_CALLED(maphist);
1616
1617 UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, flags=0x%x)",
1618 map, hint, length, flags);
1619 KASSERT((align & (align - 1)) == 0);
1620 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0);
1621
1622 uvm_map_check(map, "map_findspace entry");
1623
1624 /*
1625 * remember the original hint. if we are aligning, then we
1626 * may have to try again with no alignment constraint if
1627 * we fail the first time.
1628 */
1629
1630 orig_hint = hint;
1631 if (hint < vm_map_min(map)) { /* check ranges ... */
1632 if (flags & UVM_FLAG_FIXED) {
1633 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0);
1634 return (NULL);
1635 }
1636 hint = vm_map_min(map);
1637 }
1638 if (hint > vm_map_max(map)) {
1639 UVMHIST_LOG(maphist,"<- VA 0x%x > range [0x%x->0x%x]",
1640 hint, vm_map_min(map), vm_map_max(map), 0);
1641 return (NULL);
1642 }
1643
1644 /*
1645 * Look for the first possible address; if there's already
1646 * something at this address, we have to start after it.
1647 */
1648
1649 /*
1650 * @@@: there are four, no, eight cases to consider.
1651 *
1652 * 0: found, fixed, bottom up -> fail
1653 * 1: found, fixed, top down -> fail
1654 * 2: found, not fixed, bottom up -> start after entry->end,
1655 * loop up
1656 * 3: found, not fixed, top down -> start before entry->start,
1657 * loop down
1658 * 4: not found, fixed, bottom up -> check entry->next->start, fail
1659 * 5: not found, fixed, top down -> check entry->next->start, fail
1660 * 6: not found, not fixed, bottom up -> check entry->next->start,
1661 * loop up
1662 * 7: not found, not fixed, top down -> check entry->next->start,
1663 * loop down
1664 *
1665 * as you can see, it reduces to roughly five cases, and that
1666 * adding top down mapping only adds one unique case (without
1667 * it, there would be four cases).
1668 */
1669
1670 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) {
1671 entry = map->first_free;
1672 } else {
1673 if (uvm_map_lookup_entry(map, hint, &entry)) {
1674 /* "hint" address already in use ... */
1675 if (flags & UVM_FLAG_FIXED) {
1676 UVMHIST_LOG(maphist, "<- fixed & VA in use",
1677 0, 0, 0, 0);
1678 return (NULL);
1679 }
1680 if (topdown)
1681 /* Start from lower gap. */
1682 entry = entry->prev;
1683 } else if (flags & UVM_FLAG_FIXED) {
1684 if (entry->next->start >= hint + length &&
1685 hint + length > hint)
1686 goto found;
1687
1688 /* "hint" address is gap but too small */
1689 UVMHIST_LOG(maphist, "<- fixed mapping failed",
1690 0, 0, 0, 0);
1691 return (NULL); /* only one shot at it ... */
1692 } else {
1693 /*
1694 * See if given hint fits in this gap.
1695 */
1696 switch (uvm_map_space_avail(&hint, length,
1697 uoffset, align, topdown, entry)) {
1698 case 1:
1699 goto found;
1700 case -1:
1701 goto wraparound;
1702 }
1703
1704 if (topdown) {
1705 /*
1706 * Still there is a chance to fit
1707 * if hint > entry->end.
1708 */
1709 } else {
1710 /* Start from higher gap. */
1711 entry = entry->next;
1712 if (entry == &map->header)
1713 goto notfound;
1714 goto nextgap;
1715 }
1716 }
1717 }
1718
1719 /*
1720 * Note that all UVM_FLAGS_FIXED case is already handled.
1721 */
1722 KDASSERT((flags & UVM_FLAG_FIXED) == 0);
1723
1724 /* Try to find the space in the red-black tree */
1725
1726 /* Check slot before any entry */
1727 hint = topdown ? entry->next->start - length : entry->end;
1728 switch (uvm_map_space_avail(&hint, length, uoffset, align,
1729 topdown, entry)) {
1730 case 1:
1731 goto found;
1732 case -1:
1733 goto wraparound;
1734 }
1735
1736 nextgap:
1737 KDASSERT((flags & UVM_FLAG_FIXED) == 0);
1738 /* If there is not enough space in the whole tree, we fail */
1739 tmp = RB_ROOT(&map->rbhead);
1740 if (tmp == NULL || tmp->space < length)
1741 goto notfound;
1742
1743 prev = NULL; /* previous candidate */
1744
1745 /* Find an entry close to hint that has enough space */
1746 for (; tmp;) {
1747 KASSERT(tmp->next->start == tmp->end + tmp->ownspace);
1748 if (topdown) {
1749 if (tmp->next->start < hint + length &&
1750 (prev == NULL || tmp->end > prev->end)) {
1751 if (tmp->ownspace >= length)
1752 prev = tmp;
1753 else if ((child = RB_LEFT(tmp, rb_entry))
1754 != NULL && child->space >= length)
1755 prev = tmp;
1756 }
1757 } else {
1758 if (tmp->end >= hint &&
1759 (prev == NULL || tmp->end < prev->end)) {
1760 if (tmp->ownspace >= length)
1761 prev = tmp;
1762 else if ((child = RB_RIGHT(tmp, rb_entry))
1763 != NULL && child->space >= length)
1764 prev = tmp;
1765 }
1766 }
1767 if (tmp->next->start < hint + length)
1768 child = RB_RIGHT(tmp, rb_entry);
1769 else if (tmp->end > hint)
1770 child = RB_LEFT(tmp, rb_entry);
1771 else {
1772 if (tmp->ownspace >= length)
1773 break;
1774 if (topdown)
1775 child = RB_LEFT(tmp, rb_entry);
1776 else
1777 child = RB_RIGHT(tmp, rb_entry);
1778 }
1779 if (child == NULL || child->space < length)
1780 break;
1781 tmp = child;
1782 }
1783
1784 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) {
1785 /*
1786 * Check if the entry that we found satifies the
1787 * space requirement
1788 */
1789 if (topdown) {
1790 if (hint > tmp->next->start - length)
1791 hint = tmp->next->start - length;
1792 } else {
1793 if (hint < tmp->end)
1794 hint = tmp->end;
1795 }
1796 switch (uvm_map_space_avail(&hint, length, uoffset, align,
1797 topdown, tmp)) {
1798 case 1:
1799 entry = tmp;
1800 goto found;
1801 case -1:
1802 goto wraparound;
1803 }
1804 if (tmp->ownspace >= length)
1805 goto listsearch;
1806 }
1807 if (prev == NULL)
1808 goto notfound;
1809
1810 if (topdown) {
1811 KASSERT(orig_hint >= prev->next->start - length ||
1812 prev->next->start - length > prev->next->start);
1813 hint = prev->next->start - length;
1814 } else {
1815 KASSERT(orig_hint <= prev->end);
1816 hint = prev->end;
1817 }
1818 switch (uvm_map_space_avail(&hint, length, uoffset, align,
1819 topdown, prev)) {
1820 case 1:
1821 entry = prev;
1822 goto found;
1823 case -1:
1824 goto wraparound;
1825 }
1826 if (prev->ownspace >= length)
1827 goto listsearch;
1828
1829 if (topdown)
1830 tmp = RB_LEFT(prev, rb_entry);
1831 else
1832 tmp = RB_RIGHT(prev, rb_entry);
1833 for (;;) {
1834 KASSERT(tmp && tmp->space >= length);
1835 if (topdown)
1836 child = RB_RIGHT(tmp, rb_entry);
1837 else
1838 child = RB_LEFT(tmp, rb_entry);
1839 if (child && child->space >= length) {
1840 tmp = child;
1841 continue;
1842 }
1843 if (tmp->ownspace >= length)
1844 break;
1845 if (topdown)
1846 tmp = RB_LEFT(tmp, rb_entry);
1847 else
1848 tmp = RB_RIGHT(tmp, rb_entry);
1849 }
1850
1851 if (topdown) {
1852 KASSERT(orig_hint >= tmp->next->start - length ||
1853 tmp->next->start - length > tmp->next->start);
1854 hint = tmp->next->start - length;
1855 } else {
1856 KASSERT(orig_hint <= tmp->end);
1857 hint = tmp->end;
1858 }
1859 switch (uvm_map_space_avail(&hint, length, uoffset, align,
1860 topdown, tmp)) {
1861 case 1:
1862 entry = tmp;
1863 goto found;
1864 case -1:
1865 goto wraparound;
1866 }
1867
1868 /*
1869 * The tree fails to find an entry because of offset or alignment
1870 * restrictions. Search the list instead.
1871 */
1872 listsearch:
1873 /*
1874 * Look through the rest of the map, trying to fit a new region in
1875 * the gap between existing regions, or after the very last region.
1876 * note: entry->end = base VA of current gap,
1877 * entry->next->start = VA of end of current gap
1878 */
1879
1880 for (;;) {
1881 /* Update hint for current gap. */
1882 hint = topdown ? entry->next->start - length : entry->end;
1883
1884 /* See if it fits. */
1885 switch (uvm_map_space_avail(&hint, length, uoffset, align,
1886 topdown, entry)) {
1887 case 1:
1888 goto found;
1889 case -1:
1890 goto wraparound;
1891 }
1892
1893 /* Advance to next/previous gap */
1894 if (topdown) {
1895 if (entry == &map->header) {
1896 UVMHIST_LOG(maphist, "<- failed (off start)",
1897 0,0,0,0);
1898 goto notfound;
1899 }
1900 entry = entry->prev;
1901 } else {
1902 entry = entry->next;
1903 if (entry == &map->header) {
1904 UVMHIST_LOG(maphist, "<- failed (off end)",
1905 0,0,0,0);
1906 goto notfound;
1907 }
1908 }
1909 }
1910
1911 found:
1912 SAVE_HINT(map, map->hint, entry);
1913 *result = hint;
1914 UVMHIST_LOG(maphist,"<- got it! (result=0x%x)", hint, 0,0,0);
1915 KASSERT( topdown || hint >= orig_hint);
1916 KASSERT(!topdown || hint <= orig_hint);
1917 KASSERT(entry->end <= hint);
1918 KASSERT(hint + length <= entry->next->start);
1919 return (entry);
1920
1921 wraparound:
1922 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0);
1923
1924 return (NULL);
1925
1926 notfound:
1927 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0);
1928
1929 return (NULL);
1930 }
1931
1932 /*
1933 * U N M A P - m a i n h e l p e r f u n c t i o n s
1934 */
1935
1936 /*
1937 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop")
1938 *
1939 * => caller must check alignment and size
1940 * => map must be locked by caller
1941 * => we return a list of map entries that we've remove from the map
1942 * in "entry_list"
1943 */
1944
1945 void
1946 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end,
1947 struct vm_map_entry **entry_list /* OUT */,
1948 struct uvm_mapent_reservation *umr, int flags)
1949 {
1950 struct vm_map_entry *entry, *first_entry, *next;
1951 vaddr_t len;
1952 UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist);
1953
1954 UVMHIST_LOG(maphist,"(map=0x%x, start=0x%x, end=0x%x)",
1955 map, start, end, 0);
1956 VM_MAP_RANGE_CHECK(map, start, end);
1957
1958 uvm_map_check(map, "unmap_remove entry");
1959
1960 /*
1961 * find first entry
1962 */
1963
1964 if (uvm_map_lookup_entry(map, start, &first_entry) == TRUE) {
1965 /* clip and go... */
1966 entry = first_entry;
1967 UVM_MAP_CLIP_START(map, entry, start, umr);
1968 /* critical! prevents stale hint */
1969 SAVE_HINT(map, entry, entry->prev);
1970 } else {
1971 entry = first_entry->next;
1972 }
1973
1974 /*
1975 * Save the free space hint
1976 */
1977
1978 if (map->first_free != &map->header && map->first_free->start >= start)
1979 map->first_free = entry->prev;
1980
1981 /*
1982 * note: we now re-use first_entry for a different task. we remove
1983 * a number of map entries from the map and save them in a linked
1984 * list headed by "first_entry". once we remove them from the map
1985 * the caller should unlock the map and drop the references to the
1986 * backing objects [c.f. uvm_unmap_detach]. the object is to
1987 * separate unmapping from reference dropping. why?
1988 * [1] the map has to be locked for unmapping
1989 * [2] the map need not be locked for reference dropping
1990 * [3] dropping references may trigger pager I/O, and if we hit
1991 * a pager that does synchronous I/O we may have to wait for it.
1992 * [4] we would like all waiting for I/O to occur with maps unlocked
1993 * so that we don't block other threads.
1994 */
1995
1996 first_entry = NULL;
1997 *entry_list = NULL;
1998
1999 /*
2000 * break up the area into map entry sized regions and unmap. note
2001 * that all mappings have to be removed before we can even consider
2002 * dropping references to amaps or VM objects (otherwise we could end
2003 * up with a mapping to a page on the free list which would be very bad)
2004 */
2005
2006 while ((entry != &map->header) && (entry->start < end)) {
2007 KASSERT((entry->flags & UVM_MAP_FIRST) == 0);
2008
2009 UVM_MAP_CLIP_END(map, entry, end, umr);
2010 next = entry->next;
2011 len = entry->end - entry->start;
2012
2013 /*
2014 * unwire before removing addresses from the pmap; otherwise
2015 * unwiring will put the entries back into the pmap (XXX).
2016 */
2017
2018 if (VM_MAPENT_ISWIRED(entry)) {
2019 uvm_map_entry_unwire(map, entry);
2020 }
2021 if (flags & UVM_FLAG_VAONLY) {
2022
2023 /* nothing */
2024
2025 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) {
2026
2027 /*
2028 * if the map is non-pageable, any pages mapped there
2029 * must be wired and entered with pmap_kenter_pa(),
2030 * and we should free any such pages immediately.
2031 * this is mostly used for kmem_map and mb_map.
2032 */
2033
2034 if ((entry->flags & UVM_MAP_KMAPENT) == 0) {
2035 uvm_km_pgremove_intrsafe(entry->start,
2036 entry->end);
2037 pmap_kremove(entry->start, len);
2038 }
2039 } else if (UVM_ET_ISOBJ(entry) &&
2040 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) {
2041 KASSERT(vm_map_pmap(map) == pmap_kernel());
2042
2043 /*
2044 * note: kernel object mappings are currently used in
2045 * two ways:
2046 * [1] "normal" mappings of pages in the kernel object
2047 * [2] uvm_km_valloc'd allocations in which we
2048 * pmap_enter in some non-kernel-object page
2049 * (e.g. vmapbuf).
2050 *
2051 * for case [1], we need to remove the mapping from
2052 * the pmap and then remove the page from the kernel
2053 * object (because, once pages in a kernel object are
2054 * unmapped they are no longer needed, unlike, say,
2055 * a vnode where you might want the data to persist
2056 * until flushed out of a queue).
2057 *
2058 * for case [2], we need to remove the mapping from
2059 * the pmap. there shouldn't be any pages at the
2060 * specified offset in the kernel object [but it
2061 * doesn't hurt to call uvm_km_pgremove just to be
2062 * safe?]
2063 *
2064 * uvm_km_pgremove currently does the following:
2065 * for pages in the kernel object in range:
2066 * - drops the swap slot
2067 * - uvm_pagefree the page
2068 */
2069
2070 /*
2071 * remove mappings from pmap and drop the pages
2072 * from the object. offsets are always relative
2073 * to vm_map_min(kernel_map).
2074 */
2075
2076 pmap_remove(pmap_kernel(), entry->start,
2077 entry->start + len);
2078 uvm_km_pgremove(entry->start, entry->end);
2079
2080 /*
2081 * null out kernel_object reference, we've just
2082 * dropped it
2083 */
2084
2085 entry->etype &= ~UVM_ET_OBJ;
2086 entry->object.uvm_obj = NULL;
2087 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) {
2088
2089 /*
2090 * remove mappings the standard way.
2091 */
2092
2093 pmap_remove(map->pmap, entry->start, entry->end);
2094 }
2095
2096 #if defined(DEBUG)
2097 if ((entry->flags & UVM_MAP_KMAPENT) == 0) {
2098
2099 /*
2100 * check if there's remaining mapping,
2101 * which is a bug in caller.
2102 */
2103
2104 vaddr_t va;
2105 for (va = entry->start; va < entry->end;
2106 va += PAGE_SIZE) {
2107 if (pmap_extract(vm_map_pmap(map), va, NULL)) {
2108 panic("uvm_unmap_remove: has mapping");
2109 }
2110 }
2111
2112 if (VM_MAP_IS_KERNEL(map)) {
2113 uvm_km_check_empty(entry->start, entry->end,
2114 (map->flags & VM_MAP_INTRSAFE) != 0);
2115 }
2116 }
2117 #endif /* defined(DEBUG) */
2118
2119 /*
2120 * remove entry from map and put it on our list of entries
2121 * that we've nuked. then go to next entry.
2122 */
2123
2124 UVMHIST_LOG(maphist, " removed map entry 0x%x", entry, 0, 0,0);
2125
2126 /* critical! prevents stale hint */
2127 SAVE_HINT(map, entry, entry->prev);
2128
2129 uvm_map_entry_unlink(map, entry);
2130 KASSERT(map->size >= len);
2131 map->size -= len;
2132 entry->prev = NULL;
2133 entry->next = first_entry;
2134 first_entry = entry;
2135 entry = next;
2136 }
2137 if ((map->flags & VM_MAP_DYING) == 0) {
2138 pmap_update(vm_map_pmap(map));
2139 }
2140
2141 uvm_map_check(map, "unmap_remove leave");
2142
2143 /*
2144 * now we've cleaned up the map and are ready for the caller to drop
2145 * references to the mapped objects.
2146 */
2147
2148 *entry_list = first_entry;
2149 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
2150
2151 simple_lock(&map->flags_lock);
2152 if (map->flags & VM_MAP_WANTVA) {
2153 map->flags &= ~VM_MAP_WANTVA;
2154 wakeup(&map->header);
2155 }
2156 simple_unlock(&map->flags_lock);
2157 }
2158
2159 /*
2160 * uvm_unmap_detach: drop references in a chain of map entries
2161 *
2162 * => we will free the map entries as we traverse the list.
2163 */
2164
2165 void
2166 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags)
2167 {
2168 struct vm_map_entry *next_entry;
2169 UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist);
2170
2171 while (first_entry) {
2172 KASSERT(!VM_MAPENT_ISWIRED(first_entry));
2173 UVMHIST_LOG(maphist,
2174 " detach 0x%x: amap=0x%x, obj=0x%x, submap?=%d",
2175 first_entry, first_entry->aref.ar_amap,
2176 first_entry->object.uvm_obj,
2177 UVM_ET_ISSUBMAP(first_entry));
2178
2179 /*
2180 * drop reference to amap, if we've got one
2181 */
2182
2183 if (first_entry->aref.ar_amap)
2184 uvm_map_unreference_amap(first_entry, flags);
2185
2186 /*
2187 * drop reference to our backing object, if we've got one
2188 */
2189
2190 KASSERT(!UVM_ET_ISSUBMAP(first_entry));
2191 if (UVM_ET_ISOBJ(first_entry) &&
2192 first_entry->object.uvm_obj->pgops->pgo_detach) {
2193 (*first_entry->object.uvm_obj->pgops->pgo_detach)
2194 (first_entry->object.uvm_obj);
2195 }
2196 next_entry = first_entry->next;
2197 uvm_mapent_free(first_entry);
2198 first_entry = next_entry;
2199 }
2200 UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
2201 }
2202
2203 /*
2204 * E X T R A C T I O N F U N C T I O N S
2205 */
2206
2207 /*
2208 * uvm_map_reserve: reserve space in a vm_map for future use.
2209 *
2210 * => we reserve space in a map by putting a dummy map entry in the
2211 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE)
2212 * => map should be unlocked (we will write lock it)
2213 * => we return true if we were able to reserve space
2214 * => XXXCDC: should be inline?
2215 */
2216
2217 int
2218 uvm_map_reserve(struct vm_map *map, vsize_t size,
2219 vaddr_t offset /* hint for pmap_prefer */,
2220 vsize_t align /* alignment hint */,
2221 vaddr_t *raddr /* IN:hint, OUT: reserved VA */,
2222 uvm_flag_t flags /* UVM_FLAG_FIXED or 0 */)
2223 {
2224 UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist);
2225
2226 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x, offset=0x%x,addr=0x%x)",
2227 map,size,offset,raddr);
2228
2229 size = round_page(size);
2230
2231 /*
2232 * reserve some virtual space.
2233 */
2234
2235 if (uvm_map(map, raddr, size, NULL, offset, 0,
2236 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
2237 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) {
2238 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
2239 return (FALSE);
2240 }
2241
2242 UVMHIST_LOG(maphist, "<- done (*raddr=0x%x)", *raddr,0,0,0);
2243 return (TRUE);
2244 }
2245
2246 /*
2247 * uvm_map_replace: replace a reserved (blank) area of memory with
2248 * real mappings.
2249 *
2250 * => caller must WRITE-LOCK the map
2251 * => we return TRUE if replacement was a success
2252 * => we expect the newents chain to have nnewents entrys on it and
2253 * we expect newents->prev to point to the last entry on the list
2254 * => note newents is allowed to be NULL
2255 */
2256
2257 int
2258 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end,
2259 struct vm_map_entry *newents, int nnewents)
2260 {
2261 struct vm_map_entry *oldent, *last;
2262
2263 uvm_map_check(map, "map_replace entry");
2264
2265 /*
2266 * first find the blank map entry at the specified address
2267 */
2268
2269 if (!uvm_map_lookup_entry(map, start, &oldent)) {
2270 return (FALSE);
2271 }
2272
2273 /*
2274 * check to make sure we have a proper blank entry
2275 */
2276
2277 if (end < oldent->end && !VM_MAP_USE_KMAPENT(map)) {
2278 UVM_MAP_CLIP_END(map, oldent, end, NULL);
2279 }
2280 if (oldent->start != start || oldent->end != end ||
2281 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) {
2282 return (FALSE);
2283 }
2284
2285 #ifdef DIAGNOSTIC
2286
2287 /*
2288 * sanity check the newents chain
2289 */
2290
2291 {
2292 struct vm_map_entry *tmpent = newents;
2293 int nent = 0;
2294 vaddr_t cur = start;
2295
2296 while (tmpent) {
2297 nent++;
2298 if (tmpent->start < cur)
2299 panic("uvm_map_replace1");
2300 if (tmpent->start > tmpent->end || tmpent->end > end) {
2301 printf("tmpent->start=0x%lx, tmpent->end=0x%lx, end=0x%lx\n",
2302 tmpent->start, tmpent->end, end);
2303 panic("uvm_map_replace2");
2304 }
2305 cur = tmpent->end;
2306 if (tmpent->next) {
2307 if (tmpent->next->prev != tmpent)
2308 panic("uvm_map_replace3");
2309 } else {
2310 if (newents->prev != tmpent)
2311 panic("uvm_map_replace4");
2312 }
2313 tmpent = tmpent->next;
2314 }
2315 if (nent != nnewents)
2316 panic("uvm_map_replace5");
2317 }
2318 #endif
2319
2320 /*
2321 * map entry is a valid blank! replace it. (this does all the
2322 * work of map entry link/unlink...).
2323 */
2324
2325 if (newents) {
2326 last = newents->prev;
2327
2328 /* critical: flush stale hints out of map */
2329 SAVE_HINT(map, map->hint, newents);
2330 if (map->first_free == oldent)
2331 map->first_free = last;
2332
2333 last->next = oldent->next;
2334 last->next->prev = last;
2335
2336 /* Fix RB tree */
2337 uvm_rb_remove(map, oldent);
2338
2339 newents->prev = oldent->prev;
2340 newents->prev->next = newents;
2341 map->nentries = map->nentries + (nnewents - 1);
2342
2343 /* Fixup the RB tree */
2344 {
2345 int i;
2346 struct vm_map_entry *tmp;
2347
2348 tmp = newents;
2349 for (i = 0; i < nnewents && tmp; i++) {
2350 uvm_rb_insert(map, tmp);
2351 tmp = tmp->next;
2352 }
2353 }
2354 } else {
2355 /* NULL list of new entries: just remove the old one */
2356 clear_hints(map, oldent);
2357 uvm_map_entry_unlink(map, oldent);
2358 }
2359
2360 uvm_map_check(map, "map_replace leave");
2361
2362 /*
2363 * now we can free the old blank entry and return.
2364 */
2365
2366 uvm_mapent_free(oldent);
2367 return (TRUE);
2368 }
2369
2370 /*
2371 * uvm_map_extract: extract a mapping from a map and put it somewhere
2372 * (maybe removing the old mapping)
2373 *
2374 * => maps should be unlocked (we will write lock them)
2375 * => returns 0 on success, error code otherwise
2376 * => start must be page aligned
2377 * => len must be page sized
2378 * => flags:
2379 * UVM_EXTRACT_REMOVE: remove mappings from srcmap
2380 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only)
2381 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs
2382 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go
2383 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<<
2384 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only
2385 * be used from within the kernel in a kernel level map <<<
2386 */
2387
2388 int
2389 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len,
2390 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags)
2391 {
2392 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge;
2393 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry,
2394 *deadentry, *oldentry;
2395 vsize_t elen;
2396 int nchain, error, copy_ok;
2397 UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist);
2398
2399 UVMHIST_LOG(maphist,"(srcmap=0x%x,start=0x%x, len=0x%x", srcmap, start,
2400 len,0);
2401 UVMHIST_LOG(maphist," ...,dstmap=0x%x, flags=0x%x)", dstmap,flags,0,0);
2402
2403 uvm_map_check(srcmap, "map_extract src enter");
2404 uvm_map_check(dstmap, "map_extract dst enter");
2405
2406 /*
2407 * step 0: sanity check: start must be on a page boundary, length
2408 * must be page sized. can't ask for CONTIG/QREF if you asked for
2409 * REMOVE.
2410 */
2411
2412 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0);
2413 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 ||
2414 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0);
2415
2416 /*
2417 * step 1: reserve space in the target map for the extracted area
2418 */
2419
2420 if ((flags & UVM_EXTRACT_RESERVED) == 0) {
2421 dstaddr = vm_map_min(dstmap);
2422 if (!uvm_map_reserve(dstmap, len, start, 0, &dstaddr, 0))
2423 return (ENOMEM);
2424 *dstaddrp = dstaddr; /* pass address back to caller */
2425 UVMHIST_LOG(maphist, " dstaddr=0x%x", dstaddr,0,0,0);
2426 } else {
2427 dstaddr = *dstaddrp;
2428 }
2429
2430 /*
2431 * step 2: setup for the extraction process loop by init'ing the
2432 * map entry chain, locking src map, and looking up the first useful
2433 * entry in the map.
2434 */
2435
2436 end = start + len;
2437 newend = dstaddr + len;
2438 chain = endchain = NULL;
2439 nchain = 0;
2440 vm_map_lock(srcmap);
2441
2442 if (uvm_map_lookup_entry(srcmap, start, &entry)) {
2443
2444 /* "start" is within an entry */
2445 if (flags & UVM_EXTRACT_QREF) {
2446
2447 /*
2448 * for quick references we don't clip the entry, so
2449 * the entry may map space "before" the starting
2450 * virtual address... this is the "fudge" factor
2451 * (which can be non-zero only the first time
2452 * through the "while" loop in step 3).
2453 */
2454
2455 fudge = start - entry->start;
2456 } else {
2457
2458 /*
2459 * normal reference: we clip the map to fit (thus
2460 * fudge is zero)
2461 */
2462
2463 UVM_MAP_CLIP_START(srcmap, entry, start, NULL);
2464 SAVE_HINT(srcmap, srcmap->hint, entry->prev);
2465 fudge = 0;
2466 }
2467 } else {
2468
2469 /* "start" is not within an entry ... skip to next entry */
2470 if (flags & UVM_EXTRACT_CONTIG) {
2471 error = EINVAL;
2472 goto bad; /* definite hole here ... */
2473 }
2474
2475 entry = entry->next;
2476 fudge = 0;
2477 }
2478
2479 /* save values from srcmap for step 6 */
2480 orig_entry = entry;
2481 orig_fudge = fudge;
2482
2483 /*
2484 * step 3: now start looping through the map entries, extracting
2485 * as we go.
2486 */
2487
2488 while (entry->start < end && entry != &srcmap->header) {
2489
2490 /* if we are not doing a quick reference, clip it */
2491 if ((flags & UVM_EXTRACT_QREF) == 0)
2492 UVM_MAP_CLIP_END(srcmap, entry, end, NULL);
2493
2494 /* clear needs_copy (allow chunking) */
2495 if (UVM_ET_ISNEEDSCOPY(entry)) {
2496 amap_copy(srcmap, entry,
2497 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end);
2498 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */
2499 error = ENOMEM;
2500 goto bad;
2501 }
2502
2503 /* amap_copy could clip (during chunk)! update fudge */
2504 if (fudge) {
2505 fudge = start - entry->start;
2506 orig_fudge = fudge;
2507 }
2508 }
2509
2510 /* calculate the offset of this from "start" */
2511 oldoffset = (entry->start + fudge) - start;
2512
2513 /* allocate a new map entry */
2514 newentry = uvm_mapent_alloc(dstmap, 0);
2515 if (newentry == NULL) {
2516 error = ENOMEM;
2517 goto bad;
2518 }
2519
2520 /* set up new map entry */
2521 newentry->next = NULL;
2522 newentry->prev = endchain;
2523 newentry->start = dstaddr + oldoffset;
2524 newentry->end =
2525 newentry->start + (entry->end - (entry->start + fudge));
2526 if (newentry->end > newend || newentry->end < newentry->start)
2527 newentry->end = newend;
2528 newentry->object.uvm_obj = entry->object.uvm_obj;
2529 if (newentry->object.uvm_obj) {
2530 if (newentry->object.uvm_obj->pgops->pgo_reference)
2531 newentry->object.uvm_obj->pgops->
2532 pgo_reference(newentry->object.uvm_obj);
2533 newentry->offset = entry->offset + fudge;
2534 } else {
2535 newentry->offset = 0;
2536 }
2537 newentry->etype = entry->etype;
2538 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ?
2539 entry->max_protection : entry->protection;
2540 newentry->max_protection = entry->max_protection;
2541 newentry->inheritance = entry->inheritance;
2542 newentry->wired_count = 0;
2543 newentry->aref.ar_amap = entry->aref.ar_amap;
2544 if (newentry->aref.ar_amap) {
2545 newentry->aref.ar_pageoff =
2546 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT);
2547 uvm_map_reference_amap(newentry, AMAP_SHARED |
2548 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0));
2549 } else {
2550 newentry->aref.ar_pageoff = 0;
2551 }
2552 newentry->advice = entry->advice;
2553
2554 /* now link it on the chain */
2555 nchain++;
2556 if (endchain == NULL) {
2557 chain = endchain = newentry;
2558 } else {
2559 endchain->next = newentry;
2560 endchain = newentry;
2561 }
2562
2563 /* end of 'while' loop! */
2564 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end &&
2565 (entry->next == &srcmap->header ||
2566 entry->next->start != entry->end)) {
2567 error = EINVAL;
2568 goto bad;
2569 }
2570 entry = entry->next;
2571 fudge = 0;
2572 }
2573
2574 /*
2575 * step 4: close off chain (in format expected by uvm_map_replace)
2576 */
2577
2578 if (chain)
2579 chain->prev = endchain;
2580
2581 /*
2582 * step 5: attempt to lock the dest map so we can pmap_copy.
2583 * note usage of copy_ok:
2584 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5)
2585 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7
2586 */
2587
2588 if (srcmap == dstmap || vm_map_lock_try(dstmap) == TRUE) {
2589 copy_ok = 1;
2590 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
2591 nchain)) {
2592 if (srcmap != dstmap)
2593 vm_map_unlock(dstmap);
2594 error = EIO;
2595 goto bad;
2596 }
2597 } else {
2598 copy_ok = 0;
2599 /* replace defered until step 7 */
2600 }
2601
2602 /*
2603 * step 6: traverse the srcmap a second time to do the following:
2604 * - if we got a lock on the dstmap do pmap_copy
2605 * - if UVM_EXTRACT_REMOVE remove the entries
2606 * we make use of orig_entry and orig_fudge (saved in step 2)
2607 */
2608
2609 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) {
2610
2611 /* purge possible stale hints from srcmap */
2612 if (flags & UVM_EXTRACT_REMOVE) {
2613 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev);
2614 if (srcmap->first_free != &srcmap->header &&
2615 srcmap->first_free->start >= start)
2616 srcmap->first_free = orig_entry->prev;
2617 }
2618
2619 entry = orig_entry;
2620 fudge = orig_fudge;
2621 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */
2622
2623 while (entry->start < end && entry != &srcmap->header) {
2624 if (copy_ok) {
2625 oldoffset = (entry->start + fudge) - start;
2626 elen = MIN(end, entry->end) -
2627 (entry->start + fudge);
2628 pmap_copy(dstmap->pmap, srcmap->pmap,
2629 dstaddr + oldoffset, elen,
2630 entry->start + fudge);
2631 }
2632
2633 /* we advance "entry" in the following if statement */
2634 if (flags & UVM_EXTRACT_REMOVE) {
2635 pmap_remove(srcmap->pmap, entry->start,
2636 entry->end);
2637 oldentry = entry; /* save entry */
2638 entry = entry->next; /* advance */
2639 uvm_map_entry_unlink(srcmap, oldentry);
2640 /* add to dead list */
2641 oldentry->next = deadentry;
2642 deadentry = oldentry;
2643 } else {
2644 entry = entry->next; /* advance */
2645 }
2646
2647 /* end of 'while' loop */
2648 fudge = 0;
2649 }
2650 pmap_update(srcmap->pmap);
2651
2652 /*
2653 * unlock dstmap. we will dispose of deadentry in
2654 * step 7 if needed
2655 */
2656
2657 if (copy_ok && srcmap != dstmap)
2658 vm_map_unlock(dstmap);
2659
2660 } else {
2661 deadentry = NULL;
2662 }
2663
2664 /*
2665 * step 7: we are done with the source map, unlock. if copy_ok
2666 * is 0 then we have not replaced the dummy mapping in dstmap yet
2667 * and we need to do so now.
2668 */
2669
2670 vm_map_unlock(srcmap);
2671 if ((flags & UVM_EXTRACT_REMOVE) && deadentry)
2672 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */
2673
2674 /* now do the replacement if we didn't do it in step 5 */
2675 if (copy_ok == 0) {
2676 vm_map_lock(dstmap);
2677 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
2678 nchain);
2679 vm_map_unlock(dstmap);
2680
2681 if (error == FALSE) {
2682 error = EIO;
2683 goto bad2;
2684 }
2685 }
2686
2687 uvm_map_check(srcmap, "map_extract src leave");
2688 uvm_map_check(dstmap, "map_extract dst leave");
2689
2690 return (0);
2691
2692 /*
2693 * bad: failure recovery
2694 */
2695 bad:
2696 vm_map_unlock(srcmap);
2697 bad2: /* src already unlocked */
2698 if (chain)
2699 uvm_unmap_detach(chain,
2700 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0);
2701
2702 uvm_map_check(srcmap, "map_extract src err leave");
2703 uvm_map_check(dstmap, "map_extract dst err leave");
2704
2705 if ((flags & UVM_EXTRACT_RESERVED) == 0) {
2706 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */
2707 }
2708 return (error);
2709 }
2710
2711 /* end of extraction functions */
2712
2713 /*
2714 * uvm_map_submap: punch down part of a map into a submap
2715 *
2716 * => only the kernel_map is allowed to be submapped
2717 * => the purpose of submapping is to break up the locking granularity
2718 * of a larger map
2719 * => the range specified must have been mapped previously with a uvm_map()
2720 * call [with uobj==NULL] to create a blank map entry in the main map.
2721 * [And it had better still be blank!]
2722 * => maps which contain submaps should never be copied or forked.
2723 * => to remove a submap, use uvm_unmap() on the main map
2724 * and then uvm_map_deallocate() the submap.
2725 * => main map must be unlocked.
2726 * => submap must have been init'd and have a zero reference count.
2727 * [need not be locked as we don't actually reference it]
2728 */
2729
2730 int
2731 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end,
2732 struct vm_map *submap)
2733 {
2734 struct vm_map_entry *entry;
2735 struct uvm_mapent_reservation umr;
2736 int error;
2737
2738 uvm_mapent_reserve(map, &umr, 2, 0);
2739
2740 vm_map_lock(map);
2741 VM_MAP_RANGE_CHECK(map, start, end);
2742
2743 if (uvm_map_lookup_entry(map, start, &entry)) {
2744 UVM_MAP_CLIP_START(map, entry, start, &umr);
2745 UVM_MAP_CLIP_END(map, entry, end, &umr); /* to be safe */
2746 } else {
2747 entry = NULL;
2748 }
2749
2750 if (entry != NULL &&
2751 entry->start == start && entry->end == end &&
2752 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL &&
2753 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) {
2754 entry->etype |= UVM_ET_SUBMAP;
2755 entry->object.sub_map = submap;
2756 entry->offset = 0;
2757 uvm_map_reference(submap);
2758 error = 0;
2759 } else {
2760 error = EINVAL;
2761 }
2762 vm_map_unlock(map);
2763
2764 uvm_mapent_unreserve(map, &umr);
2765
2766 return error;
2767 }
2768
2769 /*
2770 * uvm_map_setup_kernel: init in-kernel map
2771 *
2772 * => map must not be in service yet.
2773 */
2774
2775 void
2776 uvm_map_setup_kernel(struct vm_map_kernel *map,
2777 vaddr_t vmin, vaddr_t vmax, int flags)
2778 {
2779
2780 uvm_map_setup(&map->vmk_map, vmin, vmax, flags);
2781
2782 callback_head_init(&map->vmk_reclaim_callback);
2783 LIST_INIT(&map->vmk_kentry_free);
2784 map->vmk_merged_entries = NULL;
2785 }
2786
2787
2788 /*
2789 * uvm_map_protect: change map protection
2790 *
2791 * => set_max means set max_protection.
2792 * => map must be unlocked.
2793 */
2794
2795 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \
2796 ~VM_PROT_WRITE : VM_PROT_ALL)
2797
2798 int
2799 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end,
2800 vm_prot_t new_prot, boolean_t set_max)
2801 {
2802 struct vm_map_entry *current, *entry;
2803 int error = 0;
2804 UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist);
2805 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)",
2806 map, start, end, new_prot);
2807
2808 vm_map_lock(map);
2809 VM_MAP_RANGE_CHECK(map, start, end);
2810 if (uvm_map_lookup_entry(map, start, &entry)) {
2811 UVM_MAP_CLIP_START(map, entry, start, NULL);
2812 } else {
2813 entry = entry->next;
2814 }
2815
2816 /*
2817 * make a first pass to check for protection violations.
2818 */
2819
2820 current = entry;
2821 while ((current != &map->header) && (current->start < end)) {
2822 if (UVM_ET_ISSUBMAP(current)) {
2823 error = EINVAL;
2824 goto out;
2825 }
2826 if ((new_prot & current->max_protection) != new_prot) {
2827 error = EACCES;
2828 goto out;
2829 }
2830 /*
2831 * Don't allow VM_PROT_EXECUTE to be set on entries that
2832 * point to vnodes that are associated with a NOEXEC file
2833 * system.
2834 */
2835 if (UVM_ET_ISOBJ(current) &&
2836 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) {
2837 struct vnode *vp =
2838 (struct vnode *) current->object.uvm_obj;
2839
2840 if ((new_prot & VM_PROT_EXECUTE) != 0 &&
2841 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) {
2842 error = EACCES;
2843 goto out;
2844 }
2845 }
2846
2847 current = current->next;
2848 }
2849
2850 /* go back and fix up protections (no need to clip this time). */
2851
2852 current = entry;
2853 while ((current != &map->header) && (current->start < end)) {
2854 vm_prot_t old_prot;
2855
2856 UVM_MAP_CLIP_END(map, current, end, NULL);
2857 old_prot = current->protection;
2858 if (set_max)
2859 current->protection =
2860 (current->max_protection = new_prot) & old_prot;
2861 else
2862 current->protection = new_prot;
2863
2864 /*
2865 * update physical map if necessary. worry about copy-on-write
2866 * here -- CHECK THIS XXX
2867 */
2868
2869 if (current->protection != old_prot) {
2870 /* update pmap! */
2871 pmap_protect(map->pmap, current->start, current->end,
2872 current->protection & MASK(entry));
2873
2874 /*
2875 * If this entry points at a vnode, and the
2876 * protection includes VM_PROT_EXECUTE, mark
2877 * the vnode as VEXECMAP.
2878 */
2879 if (UVM_ET_ISOBJ(current)) {
2880 struct uvm_object *uobj =
2881 current->object.uvm_obj;
2882
2883 if (UVM_OBJ_IS_VNODE(uobj) &&
2884 (current->protection & VM_PROT_EXECUTE))
2885 vn_markexec((struct vnode *) uobj);
2886 }
2887 }
2888
2889 /*
2890 * If the map is configured to lock any future mappings,
2891 * wire this entry now if the old protection was VM_PROT_NONE
2892 * and the new protection is not VM_PROT_NONE.
2893 */
2894
2895 if ((map->flags & VM_MAP_WIREFUTURE) != 0 &&
2896 VM_MAPENT_ISWIRED(entry) == 0 &&
2897 old_prot == VM_PROT_NONE &&
2898 new_prot != VM_PROT_NONE) {
2899 if (uvm_map_pageable(map, entry->start,
2900 entry->end, FALSE,
2901 UVM_LK_ENTER|UVM_LK_EXIT) != 0) {
2902
2903 /*
2904 * If locking the entry fails, remember the
2905 * error if it's the first one. Note we
2906 * still continue setting the protection in
2907 * the map, but will return the error
2908 * condition regardless.
2909 *
2910 * XXX Ignore what the actual error is,
2911 * XXX just call it a resource shortage
2912 * XXX so that it doesn't get confused
2913 * XXX what uvm_map_protect() itself would
2914 * XXX normally return.
2915 */
2916
2917 error = ENOMEM;
2918 }
2919 }
2920 current = current->next;
2921 }
2922 pmap_update(map->pmap);
2923
2924 out:
2925 vm_map_unlock(map);
2926
2927 UVMHIST_LOG(maphist, "<- done, error=%d",error,0,0,0);
2928 return error;
2929 }
2930
2931 #undef MASK
2932
2933 /*
2934 * uvm_map_inherit: set inheritance code for range of addrs in map.
2935 *
2936 * => map must be unlocked
2937 * => note that the inherit code is used during a "fork". see fork
2938 * code for details.
2939 */
2940
2941 int
2942 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end,
2943 vm_inherit_t new_inheritance)
2944 {
2945 struct vm_map_entry *entry, *temp_entry;
2946 UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist);
2947 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_inh=0x%x)",
2948 map, start, end, new_inheritance);
2949
2950 switch (new_inheritance) {
2951 case MAP_INHERIT_NONE:
2952 case MAP_INHERIT_COPY:
2953 case MAP_INHERIT_SHARE:
2954 break;
2955 default:
2956 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
2957 return EINVAL;
2958 }
2959
2960 vm_map_lock(map);
2961 VM_MAP_RANGE_CHECK(map, start, end);
2962 if (uvm_map_lookup_entry(map, start, &temp_entry)) {
2963 entry = temp_entry;
2964 UVM_MAP_CLIP_START(map, entry, start, NULL);
2965 } else {
2966 entry = temp_entry->next;
2967 }
2968 while ((entry != &map->header) && (entry->start < end)) {
2969 UVM_MAP_CLIP_END(map, entry, end, NULL);
2970 entry->inheritance = new_inheritance;
2971 entry = entry->next;
2972 }
2973 vm_map_unlock(map);
2974 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
2975 return 0;
2976 }
2977
2978 /*
2979 * uvm_map_advice: set advice code for range of addrs in map.
2980 *
2981 * => map must be unlocked
2982 */
2983
2984 int
2985 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice)
2986 {
2987 struct vm_map_entry *entry, *temp_entry;
2988 UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist);
2989 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_adv=0x%x)",
2990 map, start, end, new_advice);
2991
2992 vm_map_lock(map);
2993 VM_MAP_RANGE_CHECK(map, start, end);
2994 if (uvm_map_lookup_entry(map, start, &temp_entry)) {
2995 entry = temp_entry;
2996 UVM_MAP_CLIP_START(map, entry, start, NULL);
2997 } else {
2998 entry = temp_entry->next;
2999 }
3000
3001 /*
3002 * XXXJRT: disallow holes?
3003 */
3004
3005 while ((entry != &map->header) && (entry->start < end)) {
3006 UVM_MAP_CLIP_END(map, entry, end, NULL);
3007
3008 switch (new_advice) {
3009 case MADV_NORMAL:
3010 case MADV_RANDOM:
3011 case MADV_SEQUENTIAL:
3012 /* nothing special here */
3013 break;
3014
3015 default:
3016 vm_map_unlock(map);
3017 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
3018 return EINVAL;
3019 }
3020 entry->advice = new_advice;
3021 entry = entry->next;
3022 }
3023
3024 vm_map_unlock(map);
3025 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
3026 return 0;
3027 }
3028
3029 /*
3030 * uvm_map_pageable: sets the pageability of a range in a map.
3031 *
3032 * => wires map entries. should not be used for transient page locking.
3033 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()).
3034 * => regions specified as not pageable require lock-down (wired) memory
3035 * and page tables.
3036 * => map must never be read-locked
3037 * => if islocked is TRUE, map is already write-locked
3038 * => we always unlock the map, since we must downgrade to a read-lock
3039 * to call uvm_fault_wire()
3040 * => XXXCDC: check this and try and clean it up.
3041 */
3042
3043 int
3044 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end,
3045 boolean_t new_pageable, int lockflags)
3046 {
3047 struct vm_map_entry *entry, *start_entry, *failed_entry;
3048 int rv;
3049 #ifdef DIAGNOSTIC
3050 u_int timestamp_save;
3051 #endif
3052 UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist);
3053 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_pageable=0x%x)",
3054 map, start, end, new_pageable);
3055 KASSERT(map->flags & VM_MAP_PAGEABLE);
3056
3057 if ((lockflags & UVM_LK_ENTER) == 0)
3058 vm_map_lock(map);
3059 VM_MAP_RANGE_CHECK(map, start, end);
3060
3061 /*
3062 * only one pageability change may take place at one time, since
3063 * uvm_fault_wire assumes it will be called only once for each
3064 * wiring/unwiring. therefore, we have to make sure we're actually
3065 * changing the pageability for the entire region. we do so before
3066 * making any changes.
3067 */
3068
3069 if (uvm_map_lookup_entry(map, start, &start_entry) == FALSE) {
3070 if ((lockflags & UVM_LK_EXIT) == 0)
3071 vm_map_unlock(map);
3072
3073 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0);
3074 return EFAULT;
3075 }
3076 entry = start_entry;
3077
3078 /*
3079 * handle wiring and unwiring separately.
3080 */
3081
3082 if (new_pageable) { /* unwire */
3083 UVM_MAP_CLIP_START(map, entry, start, NULL);
3084
3085 /*
3086 * unwiring. first ensure that the range to be unwired is
3087 * really wired down and that there are no holes.
3088 */
3089
3090 while ((entry != &map->header) && (entry->start < end)) {
3091 if (entry->wired_count == 0 ||
3092 (entry->end < end &&
3093 (entry->next == &map->header ||
3094 entry->next->start > entry->end))) {
3095 if ((lockflags & UVM_LK_EXIT) == 0)
3096 vm_map_unlock(map);
3097 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0);
3098 return EINVAL;
3099 }
3100 entry = entry->next;
3101 }
3102
3103 /*
3104 * POSIX 1003.1b - a single munlock call unlocks a region,
3105 * regardless of the number of mlock calls made on that
3106 * region.
3107 */
3108
3109 entry = start_entry;
3110 while ((entry != &map->header) && (entry->start < end)) {
3111 UVM_MAP_CLIP_END(map, entry, end, NULL);
3112 if (VM_MAPENT_ISWIRED(entry))
3113 uvm_map_entry_unwire(map, entry);
3114 entry = entry->next;
3115 }
3116 if ((lockflags & UVM_LK_EXIT) == 0)
3117 vm_map_unlock(map);
3118 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
3119 return 0;
3120 }
3121
3122 /*
3123 * wire case: in two passes [XXXCDC: ugly block of code here]
3124 *
3125 * 1: holding the write lock, we create any anonymous maps that need
3126 * to be created. then we clip each map entry to the region to
3127 * be wired and increment its wiring count.
3128 *
3129 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault
3130 * in the pages for any newly wired area (wired_count == 1).
3131 *
3132 * downgrading to a read lock for uvm_fault_wire avoids a possible
3133 * deadlock with another thread that may have faulted on one of
3134 * the pages to be wired (it would mark the page busy, blocking
3135 * us, then in turn block on the map lock that we hold). because
3136 * of problems in the recursive lock package, we cannot upgrade
3137 * to a write lock in vm_map_lookup. thus, any actions that
3138 * require the write lock must be done beforehand. because we
3139 * keep the read lock on the map, the copy-on-write status of the
3140 * entries we modify here cannot change.
3141 */
3142
3143 while ((entry != &map->header) && (entry->start < end)) {
3144 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
3145
3146 /*
3147 * perform actions of vm_map_lookup that need the
3148 * write lock on the map: create an anonymous map
3149 * for a copy-on-write region, or an anonymous map
3150 * for a zero-fill region. (XXXCDC: submap case
3151 * ok?)
3152 */
3153
3154 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
3155 if (UVM_ET_ISNEEDSCOPY(entry) &&
3156 ((entry->max_protection & VM_PROT_WRITE) ||
3157 (entry->object.uvm_obj == NULL))) {
3158 amap_copy(map, entry, 0, start, end);
3159 /* XXXCDC: wait OK? */
3160 }
3161 }
3162 }
3163 UVM_MAP_CLIP_START(map, entry, start, NULL);
3164 UVM_MAP_CLIP_END(map, entry, end, NULL);
3165 entry->wired_count++;
3166
3167 /*
3168 * Check for holes
3169 */
3170
3171 if (entry->protection == VM_PROT_NONE ||
3172 (entry->end < end &&
3173 (entry->next == &map->header ||
3174 entry->next->start > entry->end))) {
3175
3176 /*
3177 * found one. amap creation actions do not need to
3178 * be undone, but the wired counts need to be restored.
3179 */
3180
3181 while (entry != &map->header && entry->end > start) {
3182 entry->wired_count--;
3183 entry = entry->prev;
3184 }
3185 if ((lockflags & UVM_LK_EXIT) == 0)
3186 vm_map_unlock(map);
3187 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0);
3188 return EINVAL;
3189 }
3190 entry = entry->next;
3191 }
3192
3193 /*
3194 * Pass 2.
3195 */
3196
3197 #ifdef DIAGNOSTIC
3198 timestamp_save = map->timestamp;
3199 #endif
3200 vm_map_busy(map);
3201 vm_map_downgrade(map);
3202
3203 rv = 0;
3204 entry = start_entry;
3205 while (entry != &map->header && entry->start < end) {
3206 if (entry->wired_count == 1) {
3207 rv = uvm_fault_wire(map, entry->start, entry->end,
3208 entry->max_protection, 1);
3209 if (rv) {
3210
3211 /*
3212 * wiring failed. break out of the loop.
3213 * we'll clean up the map below, once we
3214 * have a write lock again.
3215 */
3216
3217 break;
3218 }
3219 }
3220 entry = entry->next;
3221 }
3222
3223 if (rv) { /* failed? */
3224
3225 /*
3226 * Get back to an exclusive (write) lock.
3227 */
3228
3229 vm_map_upgrade(map);
3230 vm_map_unbusy(map);
3231
3232 #ifdef DIAGNOSTIC
3233 if (timestamp_save != map->timestamp)
3234 panic("uvm_map_pageable: stale map");
3235 #endif
3236
3237 /*
3238 * first drop the wiring count on all the entries
3239 * which haven't actually been wired yet.
3240 */
3241
3242 failed_entry = entry;
3243 while (entry != &map->header && entry->start < end) {
3244 entry->wired_count--;
3245 entry = entry->next;
3246 }
3247
3248 /*
3249 * now, unwire all the entries that were successfully
3250 * wired above.
3251 */
3252
3253 entry = start_entry;
3254 while (entry != failed_entry) {
3255 entry->wired_count--;
3256 if (VM_MAPENT_ISWIRED(entry) == 0)
3257 uvm_map_entry_unwire(map, entry);
3258 entry = entry->next;
3259 }
3260 if ((lockflags & UVM_LK_EXIT) == 0)
3261 vm_map_unlock(map);
3262 UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0);
3263 return (rv);
3264 }
3265
3266 /* We are holding a read lock here. */
3267 if ((lockflags & UVM_LK_EXIT) == 0) {
3268 vm_map_unbusy(map);
3269 vm_map_unlock_read(map);
3270 } else {
3271
3272 /*
3273 * Get back to an exclusive (write) lock.
3274 */
3275
3276 vm_map_upgrade(map);
3277 vm_map_unbusy(map);
3278 }
3279
3280 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
3281 return 0;
3282 }
3283
3284 /*
3285 * uvm_map_pageable_all: special case of uvm_map_pageable - affects
3286 * all mapped regions.
3287 *
3288 * => map must not be locked.
3289 * => if no flags are specified, all regions are unwired.
3290 * => XXXJRT: has some of the same problems as uvm_map_pageable() above.
3291 */
3292
3293 int
3294 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit)
3295 {
3296 struct vm_map_entry *entry, *failed_entry;
3297 vsize_t size;
3298 int rv;
3299 #ifdef DIAGNOSTIC
3300 u_int timestamp_save;
3301 #endif
3302 UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist);
3303 UVMHIST_LOG(maphist,"(map=0x%x,flags=0x%x)", map, flags, 0, 0);
3304
3305 KASSERT(map->flags & VM_MAP_PAGEABLE);
3306
3307 vm_map_lock(map);
3308
3309 /*
3310 * handle wiring and unwiring separately.
3311 */
3312
3313 if (flags == 0) { /* unwire */
3314
3315 /*
3316 * POSIX 1003.1b -- munlockall unlocks all regions,
3317 * regardless of how many times mlockall has been called.
3318 */
3319
3320 for (entry = map->header.next; entry != &map->header;
3321 entry = entry->next) {
3322 if (VM_MAPENT_ISWIRED(entry))
3323 uvm_map_entry_unwire(map, entry);
3324 }
3325 vm_map_modflags(map, 0, VM_MAP_WIREFUTURE);
3326 vm_map_unlock(map);
3327 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
3328 return 0;
3329 }
3330
3331 if (flags & MCL_FUTURE) {
3332
3333 /*
3334 * must wire all future mappings; remember this.
3335 */
3336
3337 vm_map_modflags(map, VM_MAP_WIREFUTURE, 0);
3338 }
3339
3340 if ((flags & MCL_CURRENT) == 0) {
3341
3342 /*
3343 * no more work to do!
3344 */
3345
3346 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0);
3347 vm_map_unlock(map);
3348 return 0;
3349 }
3350
3351 /*
3352 * wire case: in three passes [XXXCDC: ugly block of code here]
3353 *
3354 * 1: holding the write lock, count all pages mapped by non-wired
3355 * entries. if this would cause us to go over our limit, we fail.
3356 *
3357 * 2: still holding the write lock, we create any anonymous maps that
3358 * need to be created. then we increment its wiring count.
3359 *
3360 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault
3361 * in the pages for any newly wired area (wired_count == 1).
3362 *
3363 * downgrading to a read lock for uvm_fault_wire avoids a possible
3364 * deadlock with another thread that may have faulted on one of
3365 * the pages to be wired (it would mark the page busy, blocking
3366 * us, then in turn block on the map lock that we hold). because
3367 * of problems in the recursive lock package, we cannot upgrade
3368 * to a write lock in vm_map_lookup. thus, any actions that
3369 * require the write lock must be done beforehand. because we
3370 * keep the read lock on the map, the copy-on-write status of the
3371 * entries we modify here cannot change.
3372 */
3373
3374 for (size = 0, entry = map->header.next; entry != &map->header;
3375 entry = entry->next) {
3376 if (entry->protection != VM_PROT_NONE &&
3377 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
3378 size += entry->end - entry->start;
3379 }
3380 }
3381
3382 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) {
3383 vm_map_unlock(map);
3384 return ENOMEM;
3385 }
3386
3387 if (limit != 0 &&
3388 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) {
3389 vm_map_unlock(map);
3390 return ENOMEM;
3391 }
3392
3393 /*
3394 * Pass 2.
3395 */
3396
3397 for (entry = map->header.next; entry != &map->header;
3398 entry = entry->next) {
3399 if (entry->protection == VM_PROT_NONE)
3400 continue;
3401 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
3402
3403 /*
3404 * perform actions of vm_map_lookup that need the
3405 * write lock on the map: create an anonymous map
3406 * for a copy-on-write region, or an anonymous map
3407 * for a zero-fill region. (XXXCDC: submap case
3408 * ok?)
3409 */
3410
3411 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
3412 if (UVM_ET_ISNEEDSCOPY(entry) &&
3413 ((entry->max_protection & VM_PROT_WRITE) ||
3414 (entry->object.uvm_obj == NULL))) {
3415 amap_copy(map, entry, 0, entry->start,
3416 entry->end);
3417 /* XXXCDC: wait OK? */
3418 }
3419 }
3420 }
3421 entry->wired_count++;
3422 }
3423
3424 /*
3425 * Pass 3.
3426 */
3427
3428 #ifdef DIAGNOSTIC
3429 timestamp_save = map->timestamp;
3430 #endif
3431 vm_map_busy(map);
3432 vm_map_downgrade(map);
3433
3434 rv = 0;
3435 for (entry = map->header.next; entry != &map->header;
3436 entry = entry->next) {
3437 if (entry->wired_count == 1) {
3438 rv = uvm_fault_wire(map, entry->start, entry->end,
3439 entry->max_protection, 1);
3440 if (rv) {
3441
3442 /*
3443 * wiring failed. break out of the loop.
3444 * we'll clean up the map below, once we
3445 * have a write lock again.
3446 */
3447
3448 break;
3449 }
3450 }
3451 }
3452
3453 if (rv) {
3454
3455 /*
3456 * Get back an exclusive (write) lock.
3457 */
3458
3459 vm_map_upgrade(map);
3460 vm_map_unbusy(map);
3461
3462 #ifdef DIAGNOSTIC
3463 if (timestamp_save != map->timestamp)
3464 panic("uvm_map_pageable_all: stale map");
3465 #endif
3466
3467 /*
3468 * first drop the wiring count on all the entries
3469 * which haven't actually been wired yet.
3470 *
3471 * Skip VM_PROT_NONE entries like we did above.
3472 */
3473
3474 failed_entry = entry;
3475 for (/* nothing */; entry != &map->header;
3476 entry = entry->next) {
3477 if (entry->protection == VM_PROT_NONE)
3478 continue;
3479 entry->wired_count--;
3480 }
3481
3482 /*
3483 * now, unwire all the entries that were successfully
3484 * wired above.
3485 *
3486 * Skip VM_PROT_NONE entries like we did above.
3487 */
3488
3489 for (entry = map->header.next; entry != failed_entry;
3490 entry = entry->next) {
3491 if (entry->protection == VM_PROT_NONE)
3492 continue;
3493 entry->wired_count--;
3494 if (VM_MAPENT_ISWIRED(entry))
3495 uvm_map_entry_unwire(map, entry);
3496 }
3497 vm_map_unlock(map);
3498 UVMHIST_LOG(maphist,"<- done (RV=%d)", rv,0,0,0);
3499 return (rv);
3500 }
3501
3502 /* We are holding a read lock here. */
3503 vm_map_unbusy(map);
3504 vm_map_unlock_read(map);
3505
3506 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
3507 return 0;
3508 }
3509
3510 /*
3511 * uvm_map_clean: clean out a map range
3512 *
3513 * => valid flags:
3514 * if (flags & PGO_CLEANIT): dirty pages are cleaned first
3515 * if (flags & PGO_SYNCIO): dirty pages are written synchronously
3516 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean
3517 * if (flags & PGO_FREE): any cached pages are freed after clean
3518 * => returns an error if any part of the specified range isn't mapped
3519 * => never a need to flush amap layer since the anonymous memory has
3520 * no permanent home, but may deactivate pages there
3521 * => called from sys_msync() and sys_madvise()
3522 * => caller must not write-lock map (read OK).
3523 * => we may sleep while cleaning if SYNCIO [with map read-locked]
3524 */
3525
3526 int
3527 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags)
3528 {
3529 struct vm_map_entry *current, *entry;
3530 struct uvm_object *uobj;
3531 struct vm_amap *amap;
3532 struct vm_anon *anon;
3533 struct vm_page *pg;
3534 vaddr_t offset;
3535 vsize_t size;
3536 voff_t uoff;
3537 int error, refs;
3538 UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist);
3539
3540 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,flags=0x%x)",
3541 map, start, end, flags);
3542 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) !=
3543 (PGO_FREE|PGO_DEACTIVATE));
3544
3545 vm_map_lock_read(map);
3546 VM_MAP_RANGE_CHECK(map, start, end);
3547 if (uvm_map_lookup_entry(map, start, &entry) == FALSE) {
3548 vm_map_unlock_read(map);
3549 return EFAULT;
3550 }
3551
3552 /*
3553 * Make a first pass to check for holes and wiring problems.
3554 */
3555
3556 for (current = entry; current->start < end; current = current->next) {
3557 if (UVM_ET_ISSUBMAP(current)) {
3558 vm_map_unlock_read(map);
3559 return EINVAL;
3560 }
3561 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) {
3562 vm_map_unlock_read(map);
3563 return EBUSY;
3564 }
3565 if (end <= current->end) {
3566 break;
3567 }
3568 if (current->end != current->next->start) {
3569 vm_map_unlock_read(map);
3570 return EFAULT;
3571 }
3572 }
3573
3574 error = 0;
3575 for (current = entry; start < end; current = current->next) {
3576 amap = current->aref.ar_amap; /* top layer */
3577 uobj = current->object.uvm_obj; /* bottom layer */
3578 KASSERT(start >= current->start);
3579
3580 /*
3581 * No amap cleaning necessary if:
3582 *
3583 * (1) There's no amap.
3584 *
3585 * (2) We're not deactivating or freeing pages.
3586 */
3587
3588 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0)
3589 goto flush_object;
3590
3591 amap_lock(amap);
3592 offset = start - current->start;
3593 size = MIN(end, current->end) - start;
3594 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) {
3595 anon = amap_lookup(¤t->aref, offset);
3596 if (anon == NULL)
3597 continue;
3598
3599 simple_lock(&anon->an_lock);
3600 pg = anon->an_page;
3601 if (pg == NULL) {
3602 simple_unlock(&anon->an_lock);
3603 continue;
3604 }
3605
3606 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
3607
3608 /*
3609 * In these first 3 cases, we just deactivate the page.
3610 */
3611
3612 case PGO_CLEANIT|PGO_FREE:
3613 case PGO_CLEANIT|PGO_DEACTIVATE:
3614 case PGO_DEACTIVATE:
3615 deactivate_it:
3616 /*
3617 * skip the page if it's loaned or wired,
3618 * since it shouldn't be on a paging queue
3619 * at all in these cases.
3620 */
3621
3622 uvm_lock_pageq();
3623 if (pg->loan_count != 0 ||
3624 pg->wire_count != 0) {
3625 uvm_unlock_pageq();
3626 simple_unlock(&anon->an_lock);
3627 continue;
3628 }
3629 KASSERT(pg->uanon == anon);
3630 pmap_clear_reference(pg);
3631 uvm_pagedeactivate(pg);
3632 uvm_unlock_pageq();
3633 simple_unlock(&anon->an_lock);
3634 continue;
3635
3636 case PGO_FREE:
3637
3638 /*
3639 * If there are multiple references to
3640 * the amap, just deactivate the page.
3641 */
3642
3643 if (amap_refs(amap) > 1)
3644 goto deactivate_it;
3645
3646 /* skip the page if it's wired */
3647 if (pg->wire_count != 0) {
3648 simple_unlock(&anon->an_lock);
3649 continue;
3650 }
3651 amap_unadd(¤t->aref, offset);
3652 refs = --anon->an_ref;
3653 simple_unlock(&anon->an_lock);
3654 if (refs == 0)
3655 uvm_anfree(anon);
3656 continue;
3657 }
3658 }
3659 amap_unlock(amap);
3660
3661 flush_object:
3662 /*
3663 * flush pages if we've got a valid backing object.
3664 * note that we must always clean object pages before
3665 * freeing them since otherwise we could reveal stale
3666 * data from files.
3667 */
3668
3669 uoff = current->offset + (start - current->start);
3670 size = MIN(end, current->end) - start;
3671 if (uobj != NULL) {
3672 simple_lock(&uobj->vmobjlock);
3673 if (uobj->pgops->pgo_put != NULL)
3674 error = (uobj->pgops->pgo_put)(uobj, uoff,
3675 uoff + size, flags | PGO_CLEANIT);
3676 else
3677 error = 0;
3678 }
3679 start += size;
3680 }
3681 vm_map_unlock_read(map);
3682 return (error);
3683 }
3684
3685
3686 /*
3687 * uvm_map_checkprot: check protection in map
3688 *
3689 * => must allow specified protection in a fully allocated region.
3690 * => map must be read or write locked by caller.
3691 */
3692
3693 boolean_t
3694 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end,
3695 vm_prot_t protection)
3696 {
3697 struct vm_map_entry *entry;
3698 struct vm_map_entry *tmp_entry;
3699
3700 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) {
3701 return (FALSE);
3702 }
3703 entry = tmp_entry;
3704 while (start < end) {
3705 if (entry == &map->header) {
3706 return (FALSE);
3707 }
3708
3709 /*
3710 * no holes allowed
3711 */
3712
3713 if (start < entry->start) {
3714 return (FALSE);
3715 }
3716
3717 /*
3718 * check protection associated with entry
3719 */
3720
3721 if ((entry->protection & protection) != protection) {
3722 return (FALSE);
3723 }
3724 start = entry->end;
3725 entry = entry->next;
3726 }
3727 return (TRUE);
3728 }
3729
3730 /*
3731 * uvmspace_alloc: allocate a vmspace structure.
3732 *
3733 * - structure includes vm_map and pmap
3734 * - XXX: no locking on this structure
3735 * - refcnt set to 1, rest must be init'd by caller
3736 */
3737 struct vmspace *
3738 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax)
3739 {
3740 struct vmspace *vm;
3741 UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist);
3742
3743 vm = pool_get(&uvm_vmspace_pool, PR_WAITOK);
3744 uvmspace_init(vm, NULL, vmin, vmax);
3745 UVMHIST_LOG(maphist,"<- done (vm=0x%x)", vm,0,0,0);
3746 return (vm);
3747 }
3748
3749 /*
3750 * uvmspace_init: initialize a vmspace structure.
3751 *
3752 * - XXX: no locking on this structure
3753 * - refcnt set to 1, rest must be init'd by caller
3754 */
3755 void
3756 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, vaddr_t vmax)
3757 {
3758 UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist);
3759
3760 memset(vm, 0, sizeof(*vm));
3761 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE
3762 #ifdef __USING_TOPDOWN_VM
3763 | VM_MAP_TOPDOWN
3764 #endif
3765 );
3766 if (pmap)
3767 pmap_reference(pmap);
3768 else
3769 pmap = pmap_create();
3770 vm->vm_map.pmap = pmap;
3771 vm->vm_refcnt = 1;
3772 UVMHIST_LOG(maphist,"<- done",0,0,0,0);
3773 }
3774
3775 /*
3776 * uvmspace_share: share a vmspace between two processes
3777 *
3778 * - used for vfork, threads(?)
3779 */
3780
3781 void
3782 uvmspace_share(struct proc *p1, struct proc *p2)
3783 {
3784
3785 uvmspace_addref(p1->p_vmspace);
3786 p2->p_vmspace = p1->p_vmspace;
3787 }
3788
3789 /*
3790 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace
3791 *
3792 * - XXX: no locking on vmspace
3793 */
3794
3795 void
3796 uvmspace_unshare(struct lwp *l)
3797 {
3798 struct proc *p = l->l_proc;
3799 struct vmspace *nvm, *ovm = p->p_vmspace;
3800
3801 if (ovm->vm_refcnt == 1)
3802 /* nothing to do: vmspace isn't shared in the first place */
3803 return;
3804
3805 /* make a new vmspace, still holding old one */
3806 nvm = uvmspace_fork(ovm);
3807
3808 pmap_deactivate(l); /* unbind old vmspace */
3809 p->p_vmspace = nvm;
3810 pmap_activate(l); /* switch to new vmspace */
3811
3812 uvmspace_free(ovm); /* drop reference to old vmspace */
3813 }
3814
3815 /*
3816 * uvmspace_exec: the process wants to exec a new program
3817 */
3818
3819 void
3820 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end)
3821 {
3822 struct proc *p = l->l_proc;
3823 struct vmspace *nvm, *ovm = p->p_vmspace;
3824 struct vm_map *map = &ovm->vm_map;
3825
3826 #ifdef __sparc__
3827 /* XXX cgd 960926: the sparc #ifdef should be a MD hook */
3828 kill_user_windows(l); /* before stack addresses go away */
3829 #endif
3830
3831 /*
3832 * see if more than one process is using this vmspace...
3833 */
3834
3835 if (ovm->vm_refcnt == 1) {
3836
3837 /*
3838 * if p is the only process using its vmspace then we can safely
3839 * recycle that vmspace for the program that is being exec'd.
3840 */
3841
3842 #ifdef SYSVSHM
3843 /*
3844 * SYSV SHM semantics require us to kill all segments on an exec
3845 */
3846
3847 if (ovm->vm_shm)
3848 shmexit(ovm);
3849 #endif
3850
3851 /*
3852 * POSIX 1003.1b -- "lock future mappings" is revoked
3853 * when a process execs another program image.
3854 */
3855
3856 vm_map_modflags(map, 0, VM_MAP_WIREFUTURE);
3857
3858 /*
3859 * now unmap the old program
3860 */
3861
3862 pmap_remove_all(map->pmap);
3863 uvm_unmap(map, vm_map_min(map), vm_map_max(map));
3864 KASSERT(map->header.prev == &map->header);
3865 KASSERT(map->nentries == 0);
3866
3867 /*
3868 * resize the map
3869 */
3870
3871 vm_map_setmin(map, start);
3872 vm_map_setmax(map, end);
3873 } else {
3874
3875 /*
3876 * p's vmspace is being shared, so we can't reuse it for p since
3877 * it is still being used for others. allocate a new vmspace
3878 * for p
3879 */
3880
3881 nvm = uvmspace_alloc(start, end);
3882
3883 /*
3884 * install new vmspace and drop our ref to the old one.
3885 */
3886
3887 pmap_deactivate(l);
3888 p->p_vmspace = nvm;
3889 pmap_activate(l);
3890
3891 uvmspace_free(ovm);
3892 }
3893 }
3894
3895 /*
3896 * uvmspace_addref: add a referece to a vmspace.
3897 */
3898
3899 void
3900 uvmspace_addref(struct vmspace *vm)
3901 {
3902 struct vm_map *map = &vm->vm_map;
3903
3904 KASSERT((map->flags & VM_MAP_DYING) == 0);
3905
3906 simple_lock(&map->ref_lock);
3907 KASSERT(vm->vm_refcnt > 0);
3908 vm->vm_refcnt++;
3909 simple_unlock(&map->ref_lock);
3910 }
3911
3912 /*
3913 * uvmspace_free: free a vmspace data structure
3914 */
3915
3916 void
3917 uvmspace_free(struct vmspace *vm)
3918 {
3919 struct vm_map_entry *dead_entries;
3920 struct vm_map *map = &vm->vm_map;
3921 int n;
3922
3923 UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist);
3924
3925 UVMHIST_LOG(maphist,"(vm=0x%x) ref=%d", vm, vm->vm_refcnt,0,0);
3926 simple_lock(&map->ref_lock);
3927 n = --vm->vm_refcnt;
3928 simple_unlock(&map->ref_lock);
3929 if (n > 0)
3930 return;
3931
3932 /*
3933 * at this point, there should be no other references to the map.
3934 * delete all of the mappings, then destroy the pmap.
3935 */
3936
3937 map->flags |= VM_MAP_DYING;
3938 pmap_remove_all(map->pmap);
3939 #ifdef SYSVSHM
3940 /* Get rid of any SYSV shared memory segments. */
3941 if (vm->vm_shm != NULL)
3942 shmexit(vm);
3943 #endif
3944 if (map->nentries) {
3945 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map),
3946 &dead_entries, NULL, 0);
3947 if (dead_entries != NULL)
3948 uvm_unmap_detach(dead_entries, 0);
3949 }
3950 KASSERT(map->nentries == 0);
3951 KASSERT(map->size == 0);
3952 pmap_destroy(map->pmap);
3953 pool_put(&uvm_vmspace_pool, vm);
3954 }
3955
3956 /*
3957 * F O R K - m a i n e n t r y p o i n t
3958 */
3959 /*
3960 * uvmspace_fork: fork a process' main map
3961 *
3962 * => create a new vmspace for child process from parent.
3963 * => parent's map must not be locked.
3964 */
3965
3966 struct vmspace *
3967 uvmspace_fork(struct vmspace *vm1)
3968 {
3969 struct vmspace *vm2;
3970 struct vm_map *old_map = &vm1->vm_map;
3971 struct vm_map *new_map;
3972 struct vm_map_entry *old_entry;
3973 struct vm_map_entry *new_entry;
3974 UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist);
3975
3976 vm_map_lock(old_map);
3977
3978 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map));
3979 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy,
3980 (caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy);
3981 new_map = &vm2->vm_map; /* XXX */
3982
3983 old_entry = old_map->header.next;
3984 new_map->size = old_map->size;
3985
3986 /*
3987 * go entry-by-entry
3988 */
3989
3990 while (old_entry != &old_map->header) {
3991
3992 /*
3993 * first, some sanity checks on the old entry
3994 */
3995
3996 KASSERT(!UVM_ET_ISSUBMAP(old_entry));
3997 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) ||
3998 !UVM_ET_ISNEEDSCOPY(old_entry));
3999
4000 switch (old_entry->inheritance) {
4001 case MAP_INHERIT_NONE:
4002
4003 /*
4004 * drop the mapping, modify size
4005 */
4006 new_map->size -= old_entry->end - old_entry->start;
4007 break;
4008
4009 case MAP_INHERIT_SHARE:
4010
4011 /*
4012 * share the mapping: this means we want the old and
4013 * new entries to share amaps and backing objects.
4014 */
4015 /*
4016 * if the old_entry needs a new amap (due to prev fork)
4017 * then we need to allocate it now so that we have
4018 * something we own to share with the new_entry. [in
4019 * other words, we need to clear needs_copy]
4020 */
4021
4022 if (UVM_ET_ISNEEDSCOPY(old_entry)) {
4023 /* get our own amap, clears needs_copy */
4024 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK,
4025 0, 0);
4026 /* XXXCDC: WAITOK??? */
4027 }
4028
4029 new_entry = uvm_mapent_alloc(new_map, 0);
4030 /* old_entry -> new_entry */
4031 uvm_mapent_copy(old_entry, new_entry);
4032
4033 /* new pmap has nothing wired in it */
4034 new_entry->wired_count = 0;
4035
4036 /*
4037 * gain reference to object backing the map (can't
4038 * be a submap, already checked this case).
4039 */
4040
4041 if (new_entry->aref.ar_amap)
4042 uvm_map_reference_amap(new_entry, AMAP_SHARED);
4043
4044 if (new_entry->object.uvm_obj &&
4045 new_entry->object.uvm_obj->pgops->pgo_reference)
4046 new_entry->object.uvm_obj->
4047 pgops->pgo_reference(
4048 new_entry->object.uvm_obj);
4049
4050 /* insert entry at end of new_map's entry list */
4051 uvm_map_entry_link(new_map, new_map->header.prev,
4052 new_entry);
4053
4054 break;
4055
4056 case MAP_INHERIT_COPY:
4057
4058 /*
4059 * copy-on-write the mapping (using mmap's
4060 * MAP_PRIVATE semantics)
4061 *
4062 * allocate new_entry, adjust reference counts.
4063 * (note that new references are read-only).
4064 */
4065
4066 new_entry = uvm_mapent_alloc(new_map, 0);
4067 /* old_entry -> new_entry */
4068 uvm_mapent_copy(old_entry, new_entry);
4069
4070 if (new_entry->aref.ar_amap)
4071 uvm_map_reference_amap(new_entry, 0);
4072
4073 if (new_entry->object.uvm_obj &&
4074 new_entry->object.uvm_obj->pgops->pgo_reference)
4075 new_entry->object.uvm_obj->pgops->pgo_reference
4076 (new_entry->object.uvm_obj);
4077
4078 /* new pmap has nothing wired in it */
4079 new_entry->wired_count = 0;
4080
4081 new_entry->etype |=
4082 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY);
4083 uvm_map_entry_link(new_map, new_map->header.prev,
4084 new_entry);
4085
4086 /*
4087 * the new entry will need an amap. it will either
4088 * need to be copied from the old entry or created
4089 * from scratch (if the old entry does not have an
4090 * amap). can we defer this process until later
4091 * (by setting "needs_copy") or do we need to copy
4092 * the amap now?
4093 *
4094 * we must copy the amap now if any of the following
4095 * conditions hold:
4096 * 1. the old entry has an amap and that amap is
4097 * being shared. this means that the old (parent)
4098 * process is sharing the amap with another
4099 * process. if we do not clear needs_copy here
4100 * we will end up in a situation where both the
4101 * parent and child process are refering to the
4102 * same amap with "needs_copy" set. if the
4103 * parent write-faults, the fault routine will
4104 * clear "needs_copy" in the parent by allocating
4105 * a new amap. this is wrong because the
4106 * parent is supposed to be sharing the old amap
4107 * and the new amap will break that.
4108 *
4109 * 2. if the old entry has an amap and a non-zero
4110 * wire count then we are going to have to call
4111 * amap_cow_now to avoid page faults in the
4112 * parent process. since amap_cow_now requires
4113 * "needs_copy" to be clear we might as well
4114 * clear it here as well.
4115 *
4116 */
4117
4118 if (old_entry->aref.ar_amap != NULL) {
4119 if ((amap_flags(old_entry->aref.ar_amap) &
4120 AMAP_SHARED) != 0 ||
4121 VM_MAPENT_ISWIRED(old_entry)) {
4122
4123 amap_copy(new_map, new_entry,
4124 AMAP_COPY_NOCHUNK, 0, 0);
4125 /* XXXCDC: M_WAITOK ... ok? */
4126 }
4127 }
4128
4129 /*
4130 * if the parent's entry is wired down, then the
4131 * parent process does not want page faults on
4132 * access to that memory. this means that we
4133 * cannot do copy-on-write because we can't write
4134 * protect the old entry. in this case we
4135 * resolve all copy-on-write faults now, using
4136 * amap_cow_now. note that we have already
4137 * allocated any needed amap (above).
4138 */
4139
4140 if (VM_MAPENT_ISWIRED(old_entry)) {
4141
4142 /*
4143 * resolve all copy-on-write faults now
4144 * (note that there is nothing to do if
4145 * the old mapping does not have an amap).
4146 */
4147 if (old_entry->aref.ar_amap)
4148 amap_cow_now(new_map, new_entry);
4149
4150 } else {
4151
4152 /*
4153 * setup mappings to trigger copy-on-write faults
4154 * we must write-protect the parent if it has
4155 * an amap and it is not already "needs_copy"...
4156 * if it is already "needs_copy" then the parent
4157 * has already been write-protected by a previous
4158 * fork operation.
4159 */
4160
4161 if (old_entry->aref.ar_amap &&
4162 !UVM_ET_ISNEEDSCOPY(old_entry)) {
4163 if (old_entry->max_protection & VM_PROT_WRITE) {
4164 pmap_protect(old_map->pmap,
4165 old_entry->start,
4166 old_entry->end,
4167 old_entry->protection &
4168 ~VM_PROT_WRITE);
4169 pmap_update(old_map->pmap);
4170 }
4171 old_entry->etype |= UVM_ET_NEEDSCOPY;
4172 }
4173 }
4174 break;
4175 } /* end of switch statement */
4176 old_entry = old_entry->next;
4177 }
4178
4179 vm_map_unlock(old_map);
4180
4181 #ifdef SYSVSHM
4182 if (vm1->vm_shm)
4183 shmfork(vm1, vm2);
4184 #endif
4185
4186 #ifdef PMAP_FORK
4187 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap);
4188 #endif
4189
4190 UVMHIST_LOG(maphist,"<- done",0,0,0,0);
4191 return (vm2);
4192 }
4193
4194
4195 /*
4196 * in-kernel map entry allocation.
4197 */
4198
4199 struct uvm_kmapent_hdr {
4200 LIST_ENTRY(uvm_kmapent_hdr) ukh_listq;
4201 int ukh_nused;
4202 struct vm_map_entry *ukh_freelist;
4203 struct vm_map *ukh_map;
4204 struct vm_map_entry ukh_entries[0];
4205 };
4206
4207 #define UVM_KMAPENT_CHUNK \
4208 ((PAGE_SIZE - sizeof(struct uvm_kmapent_hdr)) \
4209 / sizeof(struct vm_map_entry))
4210
4211 #define UVM_KHDR_FIND(entry) \
4212 ((struct uvm_kmapent_hdr *)(((vaddr_t)entry) & ~PAGE_MASK))
4213
4214
4215 #ifdef DIAGNOSTIC
4216 static struct vm_map *
4217 uvm_kmapent_map(struct vm_map_entry *entry)
4218 {
4219 const struct uvm_kmapent_hdr *ukh;
4220
4221 ukh = UVM_KHDR_FIND(entry);
4222 return ukh->ukh_map;
4223 }
4224 #endif
4225
4226 static inline struct vm_map_entry *
4227 uvm_kmapent_get(struct uvm_kmapent_hdr *ukh)
4228 {
4229 struct vm_map_entry *entry;
4230
4231 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK);
4232 KASSERT(ukh->ukh_nused >= 0);
4233
4234 entry = ukh->ukh_freelist;
4235 if (entry) {
4236 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT))
4237 == UVM_MAP_KERNEL);
4238 ukh->ukh_freelist = entry->next;
4239 ukh->ukh_nused++;
4240 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK);
4241 } else {
4242 KASSERT(ukh->ukh_nused == UVM_KMAPENT_CHUNK);
4243 }
4244
4245 return entry;
4246 }
4247
4248 static inline void
4249 uvm_kmapent_put(struct uvm_kmapent_hdr *ukh, struct vm_map_entry *entry)
4250 {
4251
4252 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT))
4253 == UVM_MAP_KERNEL);
4254 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK);
4255 KASSERT(ukh->ukh_nused > 0);
4256 KASSERT(ukh->ukh_freelist != NULL ||
4257 ukh->ukh_nused == UVM_KMAPENT_CHUNK);
4258 KASSERT(ukh->ukh_freelist == NULL ||
4259 ukh->ukh_nused < UVM_KMAPENT_CHUNK);
4260
4261 ukh->ukh_nused--;
4262 entry->next = ukh->ukh_freelist;
4263 ukh->ukh_freelist = entry;
4264 }
4265
4266 /*
4267 * uvm_kmapent_alloc: allocate a map entry for in-kernel map
4268 */
4269
4270 static struct vm_map_entry *
4271 uvm_kmapent_alloc(struct vm_map *map, int flags)
4272 {
4273 struct vm_page *pg;
4274 struct uvm_map_args args;
4275 struct uvm_kmapent_hdr *ukh;
4276 struct vm_map_entry *entry;
4277 uvm_flag_t mapflags = UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL,
4278 UVM_INH_NONE, UVM_ADV_RANDOM, flags | UVM_FLAG_NOMERGE);
4279 vaddr_t va;
4280 int error;
4281 int i;
4282 int s;
4283
4284 KDASSERT(UVM_KMAPENT_CHUNK > 2);
4285 KDASSERT(kernel_map != NULL);
4286 KASSERT(vm_map_pmap(map) == pmap_kernel());
4287
4288 UVMMAP_EVCNT_INCR(uke_alloc);
4289 entry = NULL;
4290 again:
4291 /*
4292 * try to grab an entry from freelist.
4293 */
4294 s = splvm();
4295 simple_lock(&uvm.kentry_lock);
4296 ukh = LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free);
4297 if (ukh) {
4298 entry = uvm_kmapent_get(ukh);
4299 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK)
4300 LIST_REMOVE(ukh, ukh_listq);
4301 }
4302 simple_unlock(&uvm.kentry_lock);
4303 splx(s);
4304
4305 if (entry)
4306 return entry;
4307
4308 /*
4309 * there's no free entry for this vm_map.
4310 * now we need to allocate some vm_map_entry.
4311 * for simplicity, always allocate one page chunk of them at once.
4312 */
4313
4314 pg = uvm_pagealloc(NULL, 0, NULL, 0);
4315 if (__predict_false(pg == NULL)) {
4316 if (flags & UVM_FLAG_NOWAIT)
4317 return NULL;
4318 uvm_wait("kme_alloc");
4319 goto again;
4320 }
4321
4322 error = uvm_map_prepare(map, 0, PAGE_SIZE, NULL, UVM_UNKNOWN_OFFSET,
4323 0, mapflags, &args);
4324 if (error) {
4325 uvm_pagefree(pg);
4326 return NULL;
4327 }
4328
4329 va = args.uma_start;
4330
4331 pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), VM_PROT_READ|VM_PROT_WRITE);
4332 pmap_update(vm_map_pmap(map));
4333
4334 ukh = (void *)va;
4335
4336 /*
4337 * use the first entry for ukh itsself.
4338 */
4339
4340 entry = &ukh->ukh_entries[0];
4341 entry->flags = UVM_MAP_KERNEL | UVM_MAP_KMAPENT;
4342 error = uvm_map_enter(map, &args, entry);
4343 KASSERT(error == 0);
4344
4345 ukh->ukh_nused = UVM_KMAPENT_CHUNK;
4346 ukh->ukh_map = map;
4347 ukh->ukh_freelist = NULL;
4348 for (i = UVM_KMAPENT_CHUNK - 1; i >= 2; i--) {
4349 struct vm_map_entry *xentry = &ukh->ukh_entries[i];
4350
4351 xentry->flags = UVM_MAP_KERNEL;
4352 uvm_kmapent_put(ukh, xentry);
4353 }
4354 KASSERT(ukh->ukh_nused == 2);
4355
4356 s = splvm();
4357 simple_lock(&uvm.kentry_lock);
4358 LIST_INSERT_HEAD(&vm_map_to_kernel(map)->vmk_kentry_free,
4359 ukh, ukh_listq);
4360 simple_unlock(&uvm.kentry_lock);
4361 splx(s);
4362
4363 /*
4364 * return second entry.
4365 */
4366
4367 entry = &ukh->ukh_entries[1];
4368 entry->flags = UVM_MAP_KERNEL;
4369 UVMMAP_EVCNT_INCR(ukh_alloc);
4370 return entry;
4371 }
4372
4373 /*
4374 * uvm_mapent_free: free map entry for in-kernel map
4375 */
4376
4377 static void
4378 uvm_kmapent_free(struct vm_map_entry *entry)
4379 {
4380 struct uvm_kmapent_hdr *ukh;
4381 struct vm_page *pg;
4382 struct vm_map *map;
4383 struct pmap *pmap;
4384 vaddr_t va;
4385 paddr_t pa;
4386 struct vm_map_entry *deadentry;
4387 int s;
4388
4389 UVMMAP_EVCNT_INCR(uke_free);
4390 ukh = UVM_KHDR_FIND(entry);
4391 map = ukh->ukh_map;
4392
4393 s = splvm();
4394 simple_lock(&uvm.kentry_lock);
4395 uvm_kmapent_put(ukh, entry);
4396 if (ukh->ukh_nused > 1) {
4397 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK - 1)
4398 LIST_INSERT_HEAD(
4399 &vm_map_to_kernel(map)->vmk_kentry_free,
4400 ukh, ukh_listq);
4401 simple_unlock(&uvm.kentry_lock);
4402 splx(s);
4403 return;
4404 }
4405
4406 /*
4407 * now we can free this ukh.
4408 *
4409 * however, keep an empty ukh to avoid ping-pong.
4410 */
4411
4412 if (LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free) == ukh &&
4413 LIST_NEXT(ukh, ukh_listq) == NULL) {
4414 simple_unlock(&uvm.kentry_lock);
4415 splx(s);
4416 return;
4417 }
4418 LIST_REMOVE(ukh, ukh_listq);
4419 simple_unlock(&uvm.kentry_lock);
4420 splx(s);
4421
4422 KASSERT(ukh->ukh_nused == 1);
4423
4424 /*
4425 * remove map entry for ukh itsself.
4426 */
4427
4428 va = (vaddr_t)ukh;
4429 KASSERT((va & PAGE_MASK) == 0);
4430 vm_map_lock(map);
4431 uvm_unmap_remove(map, va, va + PAGE_SIZE, &deadentry, NULL, 0);
4432 KASSERT(deadentry->flags & UVM_MAP_KERNEL);
4433 KASSERT(deadentry->flags & UVM_MAP_KMAPENT);
4434 KASSERT(deadentry->next == NULL);
4435 KASSERT(deadentry == &ukh->ukh_entries[0]);
4436
4437 /*
4438 * unmap the page from pmap and free it.
4439 */
4440
4441 pmap = vm_map_pmap(map);
4442 KASSERT(pmap == pmap_kernel());
4443 if (!pmap_extract(pmap, va, &pa))
4444 panic("%s: no mapping", __func__);
4445 pmap_kremove(va, PAGE_SIZE);
4446 vm_map_unlock(map);
4447 pg = PHYS_TO_VM_PAGE(pa);
4448 uvm_pagefree(pg);
4449 UVMMAP_EVCNT_INCR(ukh_free);
4450 }
4451
4452 static vsize_t
4453 uvm_kmapent_overhead(vsize_t size)
4454 {
4455
4456 /*
4457 * - the max number of unmerged entries is howmany(size, PAGE_SIZE)
4458 * as the min allocation unit is PAGE_SIZE.
4459 * - UVM_KMAPENT_CHUNK "kmapent"s are allocated from a page.
4460 * one of them are used to map the page itself.
4461 */
4462
4463 return howmany(howmany(size, PAGE_SIZE), (UVM_KMAPENT_CHUNK - 1)) *
4464 PAGE_SIZE;
4465 }
4466
4467 /*
4468 * map entry reservation
4469 */
4470
4471 /*
4472 * uvm_mapent_reserve: reserve map entries for clipping before locking map.
4473 *
4474 * => needed when unmapping entries allocated without UVM_FLAG_QUANTUM.
4475 * => caller shouldn't hold map locked.
4476 */
4477 int
4478 uvm_mapent_reserve(struct vm_map *map, struct uvm_mapent_reservation *umr,
4479 int nentries, int flags)
4480 {
4481
4482 umr->umr_nentries = 0;
4483
4484 if ((flags & UVM_FLAG_QUANTUM) != 0)
4485 return 0;
4486
4487 if (!VM_MAP_USE_KMAPENT(map))
4488 return 0;
4489
4490 while (nentries--) {
4491 struct vm_map_entry *ent;
4492 ent = uvm_kmapent_alloc(map, flags);
4493 if (!ent) {
4494 uvm_mapent_unreserve(map, umr);
4495 return ENOMEM;
4496 }
4497 UMR_PUTENTRY(umr, ent);
4498 }
4499
4500 return 0;
4501 }
4502
4503 /*
4504 * uvm_mapent_unreserve:
4505 *
4506 * => caller shouldn't hold map locked.
4507 * => never fail or sleep.
4508 */
4509 void
4510 uvm_mapent_unreserve(struct vm_map *map, struct uvm_mapent_reservation *umr)
4511 {
4512
4513 while (!UMR_EMPTY(umr))
4514 uvm_kmapent_free(UMR_GETENTRY(umr));
4515 }
4516
4517 /*
4518 * uvm_mapent_trymerge: try to merge an entry with its neighbors.
4519 *
4520 * => called with map locked.
4521 * => return non zero if successfully merged.
4522 */
4523
4524 int
4525 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags)
4526 {
4527 struct uvm_object *uobj;
4528 struct vm_map_entry *next;
4529 struct vm_map_entry *prev;
4530 vsize_t size;
4531 int merged = 0;
4532 boolean_t copying;
4533 int newetype;
4534
4535 if (VM_MAP_USE_KMAPENT(map)) {
4536 return 0;
4537 }
4538 if (entry->aref.ar_amap != NULL) {
4539 return 0;
4540 }
4541 if ((entry->flags & UVM_MAP_NOMERGE) != 0) {
4542 return 0;
4543 }
4544
4545 uobj = entry->object.uvm_obj;
4546 size = entry->end - entry->start;
4547 copying = (flags & UVM_MERGE_COPYING) != 0;
4548 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype;
4549
4550 next = entry->next;
4551 if (next != &map->header &&
4552 next->start == entry->end &&
4553 ((copying && next->aref.ar_amap != NULL &&
4554 amap_refs(next->aref.ar_amap) == 1) ||
4555 (!copying && next->aref.ar_amap == NULL)) &&
4556 UVM_ET_ISCOMPATIBLE(next, newetype,
4557 uobj, entry->flags, entry->protection,
4558 entry->max_protection, entry->inheritance, entry->advice,
4559 entry->wired_count) &&
4560 (uobj == NULL || entry->offset + size == next->offset)) {
4561 int error;
4562
4563 if (copying) {
4564 error = amap_extend(next, size,
4565 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS);
4566 } else {
4567 error = 0;
4568 }
4569 if (error == 0) {
4570 if (uobj) {
4571 if (uobj->pgops->pgo_detach) {
4572 uobj->pgops->pgo_detach(uobj);
4573 }
4574 }
4575
4576 entry->end = next->end;
4577 clear_hints(map, next);
4578 uvm_map_entry_unlink(map, next);
4579 if (copying) {
4580 entry->aref = next->aref;
4581 entry->etype &= ~UVM_ET_NEEDSCOPY;
4582 }
4583 uvm_map_check(map, "trymerge forwardmerge");
4584 uvm_mapent_free_merged(map, next);
4585 merged++;
4586 }
4587 }
4588
4589 prev = entry->prev;
4590 if (prev != &map->header &&
4591 prev->end == entry->start &&
4592 ((copying && !merged && prev->aref.ar_amap != NULL &&
4593 amap_refs(prev->aref.ar_amap) == 1) ||
4594 (!copying && prev->aref.ar_amap == NULL)) &&
4595 UVM_ET_ISCOMPATIBLE(prev, newetype,
4596 uobj, entry->flags, entry->protection,
4597 entry->max_protection, entry->inheritance, entry->advice,
4598 entry->wired_count) &&
4599 (uobj == NULL ||
4600 prev->offset + prev->end - prev->start == entry->offset)) {
4601 int error;
4602
4603 if (copying) {
4604 error = amap_extend(prev, size,
4605 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS);
4606 } else {
4607 error = 0;
4608 }
4609 if (error == 0) {
4610 if (uobj) {
4611 if (uobj->pgops->pgo_detach) {
4612 uobj->pgops->pgo_detach(uobj);
4613 }
4614 entry->offset = prev->offset;
4615 }
4616
4617 entry->start = prev->start;
4618 clear_hints(map, prev);
4619 uvm_map_entry_unlink(map, prev);
4620 if (copying) {
4621 entry->aref = prev->aref;
4622 entry->etype &= ~UVM_ET_NEEDSCOPY;
4623 }
4624 uvm_map_check(map, "trymerge backmerge");
4625 uvm_mapent_free_merged(map, prev);
4626 merged++;
4627 }
4628 }
4629
4630 return merged;
4631 }
4632
4633 #if defined(DDB)
4634
4635 /*
4636 * DDB hooks
4637 */
4638
4639 /*
4640 * uvm_map_printit: actually prints the map
4641 */
4642
4643 void
4644 uvm_map_printit(struct vm_map *map, boolean_t full,
4645 void (*pr)(const char *, ...))
4646 {
4647 struct vm_map_entry *entry;
4648
4649 (*pr)("MAP %p: [0x%lx->0x%lx]\n", map, vm_map_min(map),
4650 vm_map_max(map));
4651 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=0x%x\n",
4652 map->nentries, map->size, map->ref_count, map->timestamp,
4653 map->flags);
4654 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap,
4655 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap));
4656 if (!full)
4657 return;
4658 for (entry = map->header.next; entry != &map->header;
4659 entry = entry->next) {
4660 (*pr)(" - %p: 0x%lx->0x%lx: obj=%p/0x%llx, amap=%p/%d\n",
4661 entry, entry->start, entry->end, entry->object.uvm_obj,
4662 (long long)entry->offset, entry->aref.ar_amap,
4663 entry->aref.ar_pageoff);
4664 (*pr)(
4665 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, "
4666 "wc=%d, adv=%d\n",
4667 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F',
4668 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F',
4669 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F',
4670 entry->protection, entry->max_protection,
4671 entry->inheritance, entry->wired_count, entry->advice);
4672 }
4673 }
4674
4675 /*
4676 * uvm_object_printit: actually prints the object
4677 */
4678
4679 void
4680 uvm_object_printit(struct uvm_object *uobj, boolean_t full,
4681 void (*pr)(const char *, ...))
4682 {
4683 struct vm_page *pg;
4684 int cnt = 0;
4685
4686 (*pr)("OBJECT %p: locked=%d, pgops=%p, npages=%d, ",
4687 uobj, uobj->vmobjlock.lock_data, uobj->pgops, uobj->uo_npages);
4688 if (UVM_OBJ_IS_KERN_OBJECT(uobj))
4689 (*pr)("refs=<SYSTEM>\n");
4690 else
4691 (*pr)("refs=%d\n", uobj->uo_refs);
4692
4693 if (!full) {
4694 return;
4695 }
4696 (*pr)(" PAGES <pg,offset>:\n ");
4697 TAILQ_FOREACH(pg, &uobj->memq, listq) {
4698 cnt++;
4699 (*pr)("<%p,0x%llx> ", pg, (long long)pg->offset);
4700 if ((cnt % 3) == 0) {
4701 (*pr)("\n ");
4702 }
4703 }
4704 if ((cnt % 3) != 0) {
4705 (*pr)("\n");
4706 }
4707 }
4708
4709 /*
4710 * uvm_page_printit: actually print the page
4711 */
4712
4713 static const char page_flagbits[] = UVM_PGFLAGBITS;
4714 static const char page_pqflagbits[] = UVM_PQFLAGBITS;
4715
4716 void
4717 uvm_page_printit(struct vm_page *pg, boolean_t full,
4718 void (*pr)(const char *, ...))
4719 {
4720 struct vm_page *tpg;
4721 struct uvm_object *uobj;
4722 struct pglist *pgl;
4723 char pgbuf[128];
4724 char pqbuf[128];
4725
4726 (*pr)("PAGE %p:\n", pg);
4727 bitmask_snprintf(pg->flags, page_flagbits, pgbuf, sizeof(pgbuf));
4728 bitmask_snprintf(pg->pqflags, page_pqflagbits, pqbuf, sizeof(pqbuf));
4729 (*pr)(" flags=%s, pqflags=%s, wire_count=%d, pa=0x%lx\n",
4730 pgbuf, pqbuf, pg->wire_count, (long)VM_PAGE_TO_PHYS(pg));
4731 (*pr)(" uobject=%p, uanon=%p, offset=0x%llx loan_count=%d\n",
4732 pg->uobject, pg->uanon, (long long)pg->offset, pg->loan_count);
4733 #if defined(UVM_PAGE_TRKOWN)
4734 if (pg->flags & PG_BUSY)
4735 (*pr)(" owning process = %d, tag=%s\n",
4736 pg->owner, pg->owner_tag);
4737 else
4738 (*pr)(" page not busy, no owner\n");
4739 #else
4740 (*pr)(" [page ownership tracking disabled]\n");
4741 #endif
4742
4743 if (!full)
4744 return;
4745
4746 /* cross-verify object/anon */
4747 if ((pg->pqflags & PQ_FREE) == 0) {
4748 if (pg->pqflags & PQ_ANON) {
4749 if (pg->uanon == NULL || pg->uanon->an_page != pg)
4750 (*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n",
4751 (pg->uanon) ? pg->uanon->an_page : NULL);
4752 else
4753 (*pr)(" anon backpointer is OK\n");
4754 } else {
4755 uobj = pg->uobject;
4756 if (uobj) {
4757 (*pr)(" checking object list\n");
4758 TAILQ_FOREACH(tpg, &uobj->memq, listq) {
4759 if (tpg == pg) {
4760 break;
4761 }
4762 }
4763 if (tpg)
4764 (*pr)(" page found on object list\n");
4765 else
4766 (*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n");
4767 }
4768 }
4769 }
4770
4771 /* cross-verify page queue */
4772 if (pg->pqflags & PQ_FREE) {
4773 int fl = uvm_page_lookup_freelist(pg);
4774 int color = VM_PGCOLOR_BUCKET(pg);
4775 pgl = &uvm.page_free[fl].pgfl_buckets[color].pgfl_queues[
4776 ((pg)->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN];
4777 } else {
4778 pgl = NULL;
4779 }
4780
4781 if (pgl) {
4782 (*pr)(" checking pageq list\n");
4783 TAILQ_FOREACH(tpg, pgl, pageq) {
4784 if (tpg == pg) {
4785 break;
4786 }
4787 }
4788 if (tpg)
4789 (*pr)(" page found on pageq list\n");
4790 else
4791 (*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n");
4792 }
4793 }
4794
4795 /*
4796 * uvm_pages_printthem - print a summary of all managed pages
4797 */
4798
4799 void
4800 uvm_page_printall(void (*pr)(const char *, ...))
4801 {
4802 unsigned i;
4803 struct vm_page *pg;
4804
4805 (*pr)("%18s %4s %4s %18s %18s"
4806 #ifdef UVM_PAGE_TRKOWN
4807 " OWNER"
4808 #endif
4809 "\n", "PAGE", "FLAG", "PQ", "UOBJECT", "UANON");
4810 for (i = 0; i < vm_nphysseg; i++) {
4811 for (pg = vm_physmem[i].pgs; pg <= vm_physmem[i].lastpg; pg++) {
4812 (*pr)("%18p %04x %04x %18p %18p",
4813 pg, pg->flags, pg->pqflags, pg->uobject,
4814 pg->uanon);
4815 #ifdef UVM_PAGE_TRKOWN
4816 if (pg->flags & PG_BUSY)
4817 (*pr)(" %d [%s]", pg->owner, pg->owner_tag);
4818 #endif
4819 (*pr)("\n");
4820 }
4821 }
4822 }
4823
4824 #endif
4825
4826 /*
4827 * uvm_map_create: create map
4828 */
4829
4830 struct vm_map *
4831 uvm_map_create(pmap_t pmap, vaddr_t vmin, vaddr_t vmax, int flags)
4832 {
4833 struct vm_map *result;
4834
4835 MALLOC(result, struct vm_map *, sizeof(struct vm_map),
4836 M_VMMAP, M_WAITOK);
4837 uvm_map_setup(result, vmin, vmax, flags);
4838 result->pmap = pmap;
4839 return(result);
4840 }
4841
4842 /*
4843 * uvm_map_setup: init map
4844 *
4845 * => map must not be in service yet.
4846 */
4847
4848 void
4849 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags)
4850 {
4851
4852 RB_INIT(&map->rbhead);
4853 map->header.next = map->header.prev = &map->header;
4854 map->nentries = 0;
4855 map->size = 0;
4856 map->ref_count = 1;
4857 vm_map_setmin(map, vmin);
4858 vm_map_setmax(map, vmax);
4859 map->flags = flags;
4860 map->first_free = &map->header;
4861 map->hint = &map->header;
4862 map->timestamp = 0;
4863 lockinit(&map->lock, PVM, "vmmaplk", 0, 0);
4864 simple_lock_init(&map->ref_lock);
4865 simple_lock_init(&map->hint_lock);
4866 simple_lock_init(&map->flags_lock);
4867 }
4868
4869
4870 /*
4871 * U N M A P - m a i n e n t r y p o i n t
4872 */
4873
4874 /*
4875 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop")
4876 *
4877 * => caller must check alignment and size
4878 * => map must be unlocked (we will lock it)
4879 * => flags is UVM_FLAG_QUANTUM or 0.
4880 */
4881
4882 void
4883 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags)
4884 {
4885 struct vm_map_entry *dead_entries;
4886 struct uvm_mapent_reservation umr;
4887 UVMHIST_FUNC("uvm_unmap"); UVMHIST_CALLED(maphist);
4888
4889 UVMHIST_LOG(maphist, " (map=0x%x, start=0x%x, end=0x%x)",
4890 map, start, end, 0);
4891 /*
4892 * work now done by helper functions. wipe the pmap's and then
4893 * detach from the dead entries...
4894 */
4895 uvm_mapent_reserve(map, &umr, 2, flags);
4896 vm_map_lock(map);
4897 uvm_unmap_remove(map, start, end, &dead_entries, &umr, flags);
4898 vm_map_unlock(map);
4899 uvm_mapent_unreserve(map, &umr);
4900
4901 if (dead_entries != NULL)
4902 uvm_unmap_detach(dead_entries, 0);
4903
4904 UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
4905 }
4906
4907
4908 /*
4909 * uvm_map_reference: add reference to a map
4910 *
4911 * => map need not be locked (we use ref_lock).
4912 */
4913
4914 void
4915 uvm_map_reference(struct vm_map *map)
4916 {
4917 simple_lock(&map->ref_lock);
4918 map->ref_count++;
4919 simple_unlock(&map->ref_lock);
4920 }
4921
4922 struct vm_map_kernel *
4923 vm_map_to_kernel(struct vm_map *map)
4924 {
4925
4926 KASSERT(VM_MAP_IS_KERNEL(map));
4927
4928 return (struct vm_map_kernel *)map;
4929 }
4930
4931 boolean_t
4932 vm_map_starved_p(struct vm_map *map)
4933 {
4934
4935 if ((map->flags & VM_MAP_WANTVA) != 0) {
4936 return TRUE;
4937 }
4938 /* XXX */
4939 if ((vm_map_max(map) - vm_map_min(map)) / 16 * 15 < map->size) {
4940 return TRUE;
4941 }
4942 return FALSE;
4943 }
Cache object: fd7068a529214651b71ea5699e8c2d95
|