1 /* $NetBSD: uvm_map.h,v 1.49 2005/12/24 20:45:10 perry 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 int); 361 362 int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t, 363 struct uvm_object *, voff_t, vsize_t, uvm_flag_t, 364 struct uvm_map_args *); 365 int uvm_map_enter(struct vm_map *, const struct uvm_map_args *, 366 struct vm_map_entry *); 367 368 int uvm_mapent_reserve(struct vm_map *, 369 struct uvm_mapent_reservation *, int, int); 370 void uvm_mapent_unreserve(struct vm_map *, 371 struct uvm_mapent_reservation *); 372 373 int uvm_mapent_trymerge(struct vm_map *, 374 struct vm_map_entry *, int); 375 #define UVM_MERGE_COPYING 1 376 377 #endif /* _KERNEL */ 378 379 /* 380 * VM map locking operations: 381 * 382 * These operations perform locking on the data portion of the 383 * map. 384 * 385 * vm_map_lock_try: try to lock a map, failing if it is already locked. 386 * 387 * vm_map_lock: acquire an exclusive (write) lock on a map. 388 * 389 * vm_map_lock_read: acquire a shared (read) lock on a map. 390 * 391 * vm_map_unlock: release an exclusive lock on a map. 392 * 393 * vm_map_unlock_read: release a shared lock on a map. 394 * 395 * vm_map_downgrade: downgrade an exclusive lock to a shared lock. 396 * 397 * vm_map_upgrade: upgrade a shared lock to an exclusive lock. 398 * 399 * vm_map_busy: mark a map as busy. 400 * 401 * vm_map_unbusy: clear busy status on a map. 402 * 403 * Note that "intrsafe" maps use only exclusive, spin locks. We simply 404 * use the sleep lock's interlock for this. 405 */ 406 407 #ifdef _KERNEL 408 /* XXX: clean up later */ 409 #include <sys/time.h> 410 #include <sys/proc.h> /* for tsleep(), wakeup() */ 411 #include <sys/systm.h> /* for panic() */ 412 413 static inline boolean_t vm_map_lock_try(struct vm_map *); 414 static inline void vm_map_lock(struct vm_map *); 415 extern const char vmmapbsy[]; 416 417 static inline boolean_t 418 vm_map_lock_try(struct vm_map *map) 419 { 420 boolean_t rv; 421 422 if (map->flags & VM_MAP_INTRSAFE) 423 rv = simple_lock_try(&map->lock.lk_interlock); 424 else { 425 simple_lock(&map->flags_lock); 426 if (map->flags & VM_MAP_BUSY) { 427 simple_unlock(&map->flags_lock); 428 return (FALSE); 429 } 430 rv = (lockmgr(&map->lock, LK_EXCLUSIVE|LK_NOWAIT|LK_INTERLOCK, 431 &map->flags_lock) == 0); 432 } 433 434 if (rv) 435 map->timestamp++; 436 437 return (rv); 438 } 439 440 static inline void 441 vm_map_lock(struct vm_map *map) 442 { 443 int error; 444 445 if (map->flags & VM_MAP_INTRSAFE) { 446 simple_lock(&map->lock.lk_interlock); 447 return; 448 } 449 450 try_again: 451 simple_lock(&map->flags_lock); 452 while (map->flags & VM_MAP_BUSY) { 453 map->flags |= VM_MAP_WANTLOCK; 454 ltsleep(&map->flags, PVM, vmmapbsy, 0, &map->flags_lock); 455 } 456 457 error = lockmgr(&map->lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_INTERLOCK, 458 &map->flags_lock); 459 460 if (error) { 461 KASSERT(error == ENOLCK); 462 goto try_again; 463 } 464 465 (map)->timestamp++; 466 } 467 468 #ifdef DIAGNOSTIC 469 #define vm_map_lock_read(map) \ 470 do { \ 471 if ((map)->flags & VM_MAP_INTRSAFE) \ 472 panic("vm_map_lock_read: intrsafe Map"); \ 473 (void) lockmgr(&(map)->lock, LK_SHARED, NULL); \ 474 } while (/*CONSTCOND*/ 0) 475 #else 476 #define vm_map_lock_read(map) \ 477 (void) lockmgr(&(map)->lock, LK_SHARED, NULL) 478 #endif 479 480 #define vm_map_unlock(map) \ 481 do { \ 482 if ((map)->flags & VM_MAP_INTRSAFE) \ 483 simple_unlock(&(map)->lock.lk_interlock); \ 484 else \ 485 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL); \ 486 } while (/*CONSTCOND*/ 0) 487 488 #define vm_map_unlock_read(map) \ 489 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL) 490 491 #define vm_map_downgrade(map) \ 492 (void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL) 493 494 #ifdef DIAGNOSTIC 495 #define vm_map_upgrade(map) \ 496 do { \ 497 if (lockmgr(&(map)->lock, LK_UPGRADE, NULL) != 0) \ 498 panic("vm_map_upgrade: failed to upgrade lock"); \ 499 } while (/*CONSTCOND*/ 0) 500 #else 501 #define vm_map_upgrade(map) \ 502 (void) lockmgr(&(map)->lock, LK_UPGRADE, NULL) 503 #endif 504 505 #define vm_map_busy(map) \ 506 do { \ 507 simple_lock(&(map)->flags_lock); \ 508 (map)->flags |= VM_MAP_BUSY; \ 509 simple_unlock(&(map)->flags_lock); \ 510 } while (/*CONSTCOND*/ 0) 511 512 #define vm_map_unbusy(map) \ 513 do { \ 514 int oflags; \ 515 \ 516 simple_lock(&(map)->flags_lock); \ 517 oflags = (map)->flags; \ 518 (map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK); \ 519 simple_unlock(&(map)->flags_lock); \ 520 if (oflags & VM_MAP_WANTLOCK) \ 521 wakeup(&(map)->flags); \ 522 } while (/*CONSTCOND*/ 0) 523 524 #endif /* _KERNEL */ 525 526 /* 527 * Functions implemented as macros 528 */ 529 #define vm_map_min(map) ((map)->header.end) 530 #define vm_map_max(map) ((map)->header.start) 531 #define vm_map_setmin(map, v) ((map)->header.end = (v)) 532 #define vm_map_setmax(map, v) ((map)->header.start = (v)) 533 534 #define vm_map_pmap(map) ((map)->pmap) 535 536 #endif /* _UVM_UVM_MAP_H_ */ 537