FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_map.h
1 /* $NetBSD: uvm_map.h,v 1.45 2005/02/11 02:12:03 chs 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.h 8.3 (Berkeley) 3/15/94
42 * from: Id: uvm_map.h,v 1.1.2.3 1998/02/07 01:16:55 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 #ifndef _UVM_UVM_MAP_H_
70 #define _UVM_UVM_MAP_H_
71
72 /*
73 * uvm_map.h
74 */
75
76 #ifdef _KERNEL
77
78 /*
79 * macros
80 */
81
82 /*
83 * UVM_MAP_CLIP_START: ensure that the entry begins at or after
84 * the starting address, if it doesn't we split the entry.
85 *
86 * => map must be locked by caller
87 */
88
89 #define UVM_MAP_CLIP_START(MAP,ENTRY,VA,UMR) { \
90 if ((VA) > (ENTRY)->start) uvm_map_clip_start(MAP,ENTRY,VA,UMR); }
91
92 /*
93 * UVM_MAP_CLIP_END: ensure that the entry ends at or before
94 * the ending address, if it does't we split the entry.
95 *
96 * => map must be locked by caller
97 */
98
99 #define UVM_MAP_CLIP_END(MAP,ENTRY,VA,UMR) { \
100 if ((VA) < (ENTRY)->end) uvm_map_clip_end(MAP,ENTRY,VA,UMR); }
101
102 /*
103 * extract flags
104 */
105 #define UVM_EXTRACT_REMOVE 0x1 /* remove mapping from old map */
106 #define UVM_EXTRACT_CONTIG 0x2 /* try to keep it contig */
107 #define UVM_EXTRACT_QREF 0x4 /* use quick refs */
108 #define UVM_EXTRACT_FIXPROT 0x8 /* set prot to maxprot as we go */
109
110 #endif /* _KERNEL */
111
112 #include <sys/tree.h>
113 #include <sys/pool.h>
114
115 #include <uvm/uvm_anon.h>
116
117 /*
118 * Address map entries consist of start and end addresses,
119 * a VM object (or sharing map) and offset into that object,
120 * and user-exported inheritance and protection information.
121 * Also included is control information for virtual copy operations.
122 */
123 struct vm_map_entry {
124 RB_ENTRY(vm_map_entry) rb_entry; /* tree information */
125 vaddr_t ownspace; /* free space after */
126 vaddr_t space; /* space in subtree */
127 struct vm_map_entry *prev; /* previous entry */
128 struct vm_map_entry *next; /* next entry */
129 vaddr_t start; /* start address */
130 vaddr_t end; /* end address */
131 union {
132 struct uvm_object *uvm_obj; /* uvm object */
133 struct vm_map *sub_map; /* belongs to another map */
134 } object; /* object I point to */
135 voff_t offset; /* offset into object */
136 int etype; /* entry type */
137 vm_prot_t protection; /* protection code */
138 vm_prot_t max_protection; /* maximum protection */
139 vm_inherit_t inheritance; /* inheritance */
140 int wired_count; /* can be paged if == 0 */
141 struct vm_aref aref; /* anonymous overlay */
142 int advice; /* madvise advice */
143 #define uvm_map_entry_stop_copy flags
144 u_int8_t flags; /* flags */
145
146 #define UVM_MAP_KERNEL 0x01 /* kernel map entry */
147 #define UVM_MAP_KMAPENT 0x02 /* contains map entries */
148 #define UVM_MAP_FIRST 0x04 /* the first special entry */
149 #define UVM_MAP_QUANTUM 0x08 /* allocated with
150 * UVM_FLAG_QUANTUM */
151 #define UVM_MAP_NOMERGE 0x10 /* this entry is not mergable */
152
153 };
154
155 #define VM_MAPENT_ISWIRED(entry) ((entry)->wired_count != 0)
156
157 /*
158 * Maps are doubly-linked lists of map entries, kept sorted
159 * by address. A single hint is provided to start
160 * searches again from the last successful search,
161 * insertion, or removal.
162 *
163 * LOCKING PROTOCOL NOTES:
164 * -----------------------
165 *
166 * VM map locking is a little complicated. There are both shared
167 * and exclusive locks on maps. However, it is sometimes required
168 * to downgrade an exclusive lock to a shared lock, and upgrade to
169 * an exclusive lock again (to perform error recovery). However,
170 * another thread *must not* queue itself to receive an exclusive
171 * lock while before we upgrade back to exclusive, otherwise the
172 * error recovery becomes extremely difficult, if not impossible.
173 *
174 * In order to prevent this scenario, we introduce the notion of
175 * a `busy' map. A `busy' map is read-locked, but other threads
176 * attempting to write-lock wait for this flag to clear before
177 * entering the lock manager. A map may only be marked busy
178 * when the map is write-locked (and then the map must be downgraded
179 * to read-locked), and may only be marked unbusy by the thread
180 * which marked it busy (holding *either* a read-lock or a
181 * write-lock, the latter being gained by an upgrade).
182 *
183 * Access to the map `flags' member is controlled by the `flags_lock'
184 * simple lock. Note that some flags are static (set once at map
185 * creation time, and never changed), and thus require no locking
186 * to check those flags. All flags which are r/w must be set or
187 * cleared while the `flags_lock' is asserted. Additional locking
188 * requirements are:
189 *
190 * VM_MAP_PAGEABLE r/o static flag; no locking required
191 *
192 * VM_MAP_INTRSAFE r/o static flag; no locking required
193 *
194 * VM_MAP_WIREFUTURE r/w; may only be set or cleared when
195 * map is write-locked. may be tested
196 * without asserting `flags_lock'.
197 *
198 * VM_MAP_BUSY r/w; may only be set when map is
199 * write-locked, may only be cleared by
200 * thread which set it, map read-locked
201 * or write-locked. must be tested
202 * while `flags_lock' is asserted.
203 *
204 * VM_MAP_WANTLOCK r/w; may only be set when the map
205 * is busy, and thread is attempting
206 * to write-lock. must be tested
207 * while `flags_lock' is asserted.
208 *
209 * VM_MAP_DYING r/o; set when a vmspace is being
210 * destroyed to indicate that updates
211 * to the pmap can be skipped.
212 *
213 * VM_MAP_TOPDOWN r/o; set when the vmspace is
214 * created if the unspecified map
215 * allocations are to be arranged in
216 * a "top down" manner.
217 */
218 struct vm_map {
219 struct pmap * pmap; /* Physical map */
220 struct lock lock; /* Lock for map data */
221 RB_HEAD(uvm_tree, vm_map_entry) rbhead; /* Tree for entries */
222 struct vm_map_entry header; /* List of entries */
223 int nentries; /* Number of entries */
224 vsize_t size; /* virtual size */
225 int ref_count; /* Reference count */
226 struct simplelock ref_lock; /* Lock for ref_count field */
227 struct vm_map_entry * hint; /* hint for quick lookups */
228 struct simplelock hint_lock; /* lock for hint storage */
229 struct vm_map_entry * first_free; /* First free space hint */
230 int flags; /* flags */
231 struct simplelock flags_lock; /* Lock for flags field */
232 unsigned int timestamp; /* Version number */
233 };
234
235 #if defined(_KERNEL)
236 struct vm_map_kernel {
237 struct vm_map vmk_map;
238 LIST_HEAD(, uvm_kmapent_hdr) vmk_kentry_free;
239 /* Freelist of map entry */
240 struct vm_map_entry *vmk_merged_entries;
241 /* Merged entries, kept for later splitting */
242
243 #if !defined(PMAP_MAP_POOLPAGE)
244 struct pool vmk_vacache; /* kva cache */
245 struct pool_allocator vmk_vacache_allocator; /* ... and its allocator */
246 #endif
247 };
248 #endif /* defined(_KERNEL) */
249
250 #define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel())
251
252 /* vm_map flags */
253 #define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */
254 #define VM_MAP_INTRSAFE 0x02 /* ro: interrupt safe map */
255 #define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */
256 #define VM_MAP_BUSY 0x08 /* rw: map is busy */
257 #define VM_MAP_WANTLOCK 0x10 /* rw: want to write-lock */
258 #define VM_MAP_DYING 0x20 /* rw: map is being destroyed */
259 #define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */
260 #define VM_MAP_VACACHE 0x80 /* ro: use kva cache */
261 #define VM_MAP_WANTVA 0x100 /* rw: want va */
262
263 #ifdef _KERNEL
264 struct uvm_mapent_reservation {
265 struct vm_map_entry *umr_entries[2];
266 int umr_nentries;
267 };
268 #define UMR_EMPTY(umr) ((umr) == NULL || (umr)->umr_nentries == 0)
269 #define UMR_GETENTRY(umr) ((umr)->umr_entries[--(umr)->umr_nentries])
270 #define UMR_PUTENTRY(umr, ent) \
271 (umr)->umr_entries[(umr)->umr_nentries++] = (ent)
272
273 struct uvm_map_args {
274 struct vm_map_entry *uma_prev;
275
276 vaddr_t uma_start;
277 vsize_t uma_size;
278
279 struct uvm_object *uma_uobj;
280 voff_t uma_uoffset;
281
282 uvm_flag_t uma_flags;
283 };
284 #endif /* _KERNEL */
285
286 #ifdef _KERNEL
287 #define vm_map_modflags(map, set, clear) \
288 do { \
289 simple_lock(&(map)->flags_lock); \
290 (map)->flags = ((map)->flags | (set)) & ~(clear); \
291 simple_unlock(&(map)->flags_lock); \
292 } while (/*CONSTCOND*/ 0)
293 #endif /* _KERNEL */
294
295 /*
296 * handle inline options
297 */
298
299 #ifdef UVM_MAP_INLINE
300 #define MAP_INLINE static __inline
301 #else
302 #define MAP_INLINE /* nothing */
303 #endif /* UVM_MAP_INLINE */
304
305 /*
306 * globals:
307 */
308
309 #ifdef _KERNEL
310
311 #ifdef PMAP_GROWKERNEL
312 extern vaddr_t uvm_maxkaddr;
313 #endif
314
315 /*
316 * protos: the following prototypes define the interface to vm_map
317 */
318
319 MAP_INLINE
320 void uvm_map_deallocate(struct vm_map *);
321
322 int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int);
323 void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *,
324 vaddr_t, struct uvm_mapent_reservation *);
325 void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *,
326 vaddr_t, struct uvm_mapent_reservation *);
327 MAP_INLINE
328 struct vm_map *uvm_map_create(pmap_t, vaddr_t, vaddr_t, int);
329 int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t,
330 struct vm_map *, vaddr_t *, int);
331 struct vm_map_entry *
332 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t,
333 vaddr_t *, struct uvm_object *, voff_t, vsize_t, int);
334 int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t,
335 vm_inherit_t);
336 int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int);
337 void uvm_map_init(void);
338 boolean_t uvm_map_lookup_entry(struct vm_map *, vaddr_t,
339 struct vm_map_entry **);
340 MAP_INLINE
341 void uvm_map_reference(struct vm_map *);
342 int uvm_map_replace(struct vm_map *, vaddr_t, vaddr_t,
343 struct vm_map_entry *, int);
344 int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t,
345 vaddr_t *);
346 void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int);
347 void uvm_map_setup_kernel(struct vm_map_kernel *,
348 vaddr_t, vaddr_t, int);
349 MAP_INLINE
350 struct vm_map_kernel *
351 vm_map_to_kernel(struct vm_map *);
352 int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t,
353 struct vm_map *);
354 MAP_INLINE
355 void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int);
356 #define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0)
357 void uvm_unmap_detach(struct vm_map_entry *,int);
358 void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t,
359 struct vm_map_entry **, struct uvm_mapent_reservation *);
360
361 int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t,
362 struct uvm_object *, voff_t, vsize_t, uvm_flag_t,
363 struct uvm_map_args *);
364 int uvm_map_enter(struct vm_map *, const struct uvm_map_args *,
365 struct vm_map_entry *);
366
367 int uvm_mapent_reserve(struct vm_map *,
368 struct uvm_mapent_reservation *, int, int);
369 void uvm_mapent_unreserve(struct vm_map *,
370 struct uvm_mapent_reservation *);
371
372
373 #endif /* _KERNEL */
374
375 /*
376 * VM map locking operations:
377 *
378 * These operations perform locking on the data portion of the
379 * map.
380 *
381 * vm_map_lock_try: try to lock a map, failing if it is already locked.
382 *
383 * vm_map_lock: acquire an exclusive (write) lock on a map.
384 *
385 * vm_map_lock_read: acquire a shared (read) lock on a map.
386 *
387 * vm_map_unlock: release an exclusive lock on a map.
388 *
389 * vm_map_unlock_read: release a shared lock on a map.
390 *
391 * vm_map_downgrade: downgrade an exclusive lock to a shared lock.
392 *
393 * vm_map_upgrade: upgrade a shared lock to an exclusive lock.
394 *
395 * vm_map_busy: mark a map as busy.
396 *
397 * vm_map_unbusy: clear busy status on a map.
398 *
399 * Note that "intrsafe" maps use only exclusive, spin locks. We simply
400 * use the sleep lock's interlock for this.
401 */
402
403 #ifdef _KERNEL
404 /* XXX: clean up later */
405 #include <sys/time.h>
406 #include <sys/proc.h> /* for tsleep(), wakeup() */
407 #include <sys/systm.h> /* for panic() */
408
409 static __inline boolean_t vm_map_lock_try(struct vm_map *);
410 static __inline void vm_map_lock(struct vm_map *);
411 extern const char vmmapbsy[];
412
413 static __inline boolean_t
414 vm_map_lock_try(struct vm_map *map)
415 {
416 boolean_t rv;
417
418 if (map->flags & VM_MAP_INTRSAFE)
419 rv = simple_lock_try(&map->lock.lk_interlock);
420 else {
421 simple_lock(&map->flags_lock);
422 if (map->flags & VM_MAP_BUSY) {
423 simple_unlock(&map->flags_lock);
424 return (FALSE);
425 }
426 rv = (lockmgr(&map->lock, LK_EXCLUSIVE|LK_NOWAIT|LK_INTERLOCK,
427 &map->flags_lock) == 0);
428 }
429
430 if (rv)
431 map->timestamp++;
432
433 return (rv);
434 }
435
436 static __inline void
437 vm_map_lock(struct vm_map *map)
438 {
439 int error;
440
441 if (map->flags & VM_MAP_INTRSAFE) {
442 simple_lock(&map->lock.lk_interlock);
443 return;
444 }
445
446 try_again:
447 simple_lock(&map->flags_lock);
448 while (map->flags & VM_MAP_BUSY) {
449 map->flags |= VM_MAP_WANTLOCK;
450 ltsleep(&map->flags, PVM, vmmapbsy, 0, &map->flags_lock);
451 }
452
453 error = lockmgr(&map->lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_INTERLOCK,
454 &map->flags_lock);
455
456 if (error) {
457 KASSERT(error == ENOLCK);
458 goto try_again;
459 }
460
461 (map)->timestamp++;
462 }
463
464 #ifdef DIAGNOSTIC
465 #define vm_map_lock_read(map) \
466 do { \
467 if ((map)->flags & VM_MAP_INTRSAFE) \
468 panic("vm_map_lock_read: intrsafe Map"); \
469 (void) lockmgr(&(map)->lock, LK_SHARED, NULL); \
470 } while (/*CONSTCOND*/ 0)
471 #else
472 #define vm_map_lock_read(map) \
473 (void) lockmgr(&(map)->lock, LK_SHARED, NULL)
474 #endif
475
476 #define vm_map_unlock(map) \
477 do { \
478 if ((map)->flags & VM_MAP_INTRSAFE) \
479 simple_unlock(&(map)->lock.lk_interlock); \
480 else \
481 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL); \
482 } while (/*CONSTCOND*/ 0)
483
484 #define vm_map_unlock_read(map) \
485 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL)
486
487 #define vm_map_downgrade(map) \
488 (void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL)
489
490 #ifdef DIAGNOSTIC
491 #define vm_map_upgrade(map) \
492 do { \
493 if (lockmgr(&(map)->lock, LK_UPGRADE, NULL) != 0) \
494 panic("vm_map_upgrade: failed to upgrade lock"); \
495 } while (/*CONSTCOND*/ 0)
496 #else
497 #define vm_map_upgrade(map) \
498 (void) lockmgr(&(map)->lock, LK_UPGRADE, NULL)
499 #endif
500
501 #define vm_map_busy(map) \
502 do { \
503 simple_lock(&(map)->flags_lock); \
504 (map)->flags |= VM_MAP_BUSY; \
505 simple_unlock(&(map)->flags_lock); \
506 } while (/*CONSTCOND*/ 0)
507
508 #define vm_map_unbusy(map) \
509 do { \
510 int oflags; \
511 \
512 simple_lock(&(map)->flags_lock); \
513 oflags = (map)->flags; \
514 (map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK); \
515 simple_unlock(&(map)->flags_lock); \
516 if (oflags & VM_MAP_WANTLOCK) \
517 wakeup(&(map)->flags); \
518 } while (/*CONSTCOND*/ 0)
519
520 #endif /* _KERNEL */
521
522 /*
523 * Functions implemented as macros
524 */
525 #define vm_map_min(map) ((map)->header.end)
526 #define vm_map_max(map) ((map)->header.start)
527 #define vm_map_setmin(map, v) ((map)->header.end = (v))
528 #define vm_map_setmax(map, v) ((map)->header.start = (v))
529
530 #define vm_map_pmap(map) ((map)->pmap)
531
532 #endif /* _UVM_UVM_MAP_H_ */
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