1 /* $NetBSD: uvm_map.h,v 1.50 2006/01/21 13:34:15 yamt 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 0x01 /* remove mapping from old map */ 106 #define UVM_EXTRACT_CONTIG 0x02 /* try to keep it contig */ 107 #define UVM_EXTRACT_QREF 0x04 /* use quick refs */ 108 #define UVM_EXTRACT_FIXPROT 0x08 /* set prot to maxprot as we go */ 109 #define UVM_EXTRACT_RESERVED 0x10 /* caller did uvm_map_reserve() */ 110 111 #endif /* _KERNEL */ 112 113 #include <sys/tree.h> 114 #include <sys/pool.h> 115 116 #include <uvm/uvm_anon.h> 117 118 /* 119 * Address map entries consist of start and end addresses, 120 * a VM object (or sharing map) and offset into that object, 121 * and user-exported inheritance and protection information. 122 * Also included is control information for virtual copy operations. 123 */ 124 struct vm_map_entry { 125 RB_ENTRY(vm_map_entry) rb_entry; /* tree information */ 126 vaddr_t ownspace; /* free space after */ 127 vaddr_t space; /* space in subtree */ 128 struct vm_map_entry *prev; /* previous entry */ 129 struct vm_map_entry *next; /* next entry */ 130 vaddr_t start; /* start address */ 131 vaddr_t end; /* end address */ 132 union { 133 struct uvm_object *uvm_obj; /* uvm object */ 134 struct vm_map *sub_map; /* belongs to another map */ 135 } object; /* object I point to */ 136 voff_t offset; /* offset into object */ 137 int etype; /* entry type */ 138 vm_prot_t protection; /* protection code */ 139 vm_prot_t max_protection; /* maximum protection */ 140 vm_inherit_t inheritance; /* inheritance */ 141 int wired_count; /* can be paged if == 0 */ 142 struct vm_aref aref; /* anonymous overlay */ 143 int advice; /* madvise advice */ 144 #define uvm_map_entry_stop_copy flags 145 u_int8_t flags; /* flags */ 146 147 #define UVM_MAP_KERNEL 0x01 /* kernel map entry */ 148 #define UVM_MAP_KMAPENT 0x02 /* contains map entries */ 149 #define UVM_MAP_FIRST 0x04 /* the first special entry */ 150 #define UVM_MAP_QUANTUM 0x08 /* allocated with 151 * UVM_FLAG_QUANTUM */ 152 #define UVM_MAP_NOMERGE 0x10 /* this entry is not mergable */ 153 154 }; 155 156 #define VM_MAPENT_ISWIRED(entry) ((entry)->wired_count != 0) 157 158 /* 159 * Maps are doubly-linked lists of map entries, kept sorted 160 * by address. A single hint is provided to start 161 * searches again from the last successful search, 162 * insertion, or removal. 163 * 164 * LOCKING PROTOCOL NOTES: 165 * ----------------------- 166 * 167 * VM map locking is a little complicated. There are both shared 168 * and exclusive locks on maps. However, it is sometimes required 169 * to downgrade an exclusive lock to a shared lock, and upgrade to 170 * an exclusive lock again (to perform error recovery). However, 171 * another thread *must not* queue itself to receive an exclusive 172 * lock while before we upgrade back to exclusive, otherwise the 173 * error recovery becomes extremely difficult, if not impossible. 174 * 175 * In order to prevent this scenario, we introduce the notion of 176 * a `busy' map. A `busy' map is read-locked, but other threads 177 * attempting to write-lock wait for this flag to clear before 178 * entering the lock manager. A map may only be marked busy 179 * when the map is write-locked (and then the map must be downgraded 180 * to read-locked), and may only be marked unbusy by the thread 181 * which marked it busy (holding *either* a read-lock or a 182 * write-lock, the latter being gained by an upgrade). 183 * 184 * Access to the map `flags' member is controlled by the `flags_lock' 185 * simple lock. Note that some flags are static (set once at map 186 * creation time, and never changed), and thus require no locking 187 * to check those flags. All flags which are r/w must be set or 188 * cleared while the `flags_lock' is asserted. Additional locking 189 * requirements are: 190 * 191 * VM_MAP_PAGEABLE r/o static flag; no locking required 192 * 193 * VM_MAP_INTRSAFE r/o static flag; no locking required 194 * 195 * VM_MAP_WIREFUTURE r/w; may only be set or cleared when 196 * map is write-locked. may be tested 197 * without asserting `flags_lock'. 198 * 199 * VM_MAP_BUSY r/w; may only be set when map is 200 * write-locked, may only be cleared by 201 * thread which set it, map read-locked 202 * or write-locked. must be tested 203 * while `flags_lock' is asserted. 204 * 205 * VM_MAP_WANTLOCK r/w; may only be set when the map 206 * is busy, and thread is attempting 207 * to write-lock. must be tested 208 * while `flags_lock' is asserted. 209 * 210 * VM_MAP_DYING r/o; set when a vmspace is being 211 * destroyed to indicate that updates 212 * to the pmap can be skipped. 213 * 214 * VM_MAP_TOPDOWN r/o; set when the vmspace is 215 * created if the unspecified map 216 * allocations are to be arranged in 217 * a "top down" manner. 218 */ 219 struct vm_map { 220 struct pmap * pmap; /* Physical map */ 221 struct lock lock; /* Lock for map data */ 222 RB_HEAD(uvm_tree, vm_map_entry) rbhead; /* Tree for entries */ 223 struct vm_map_entry header; /* List of entries */ 224 int nentries; /* Number of entries */ 225 vsize_t size; /* virtual size */ 226 int ref_count; /* Reference count */ 227 struct simplelock ref_lock; /* Lock for ref_count field */ 228 struct vm_map_entry * hint; /* hint for quick lookups */ 229 struct simplelock hint_lock; /* lock for hint storage */ 230 struct vm_map_entry * first_free; /* First free space hint */ 231 int flags; /* flags */ 232 struct simplelock flags_lock; /* Lock for flags field */ 233 unsigned int timestamp; /* Version number */ 234 }; 235 236 #if defined(_KERNEL) 237 struct vm_map_kernel { 238 struct vm_map vmk_map; 239 LIST_HEAD(, uvm_kmapent_hdr) vmk_kentry_free; 240 /* Freelist of map entry */ 241 struct vm_map_entry *vmk_merged_entries; 242 /* Merged entries, kept for later splitting */ 243 244 #if !defined(PMAP_MAP_POOLPAGE) 245 struct pool vmk_vacache; /* kva cache */ 246 struct pool_allocator vmk_vacache_allocator; /* ... and its allocator */ 247 #endif 248 }; 249 #endif /* defined(_KERNEL) */ 250 251 #define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel()) 252 253 /* vm_map flags */ 254 #define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */ 255 #define VM_MAP_INTRSAFE 0x02 /* ro: interrupt safe map */ 256 #define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */ 257 #define VM_MAP_BUSY 0x08 /* rw: map is busy */ 258 #define VM_MAP_WANTLOCK 0x10 /* rw: want to write-lock */ 259 #define VM_MAP_DYING 0x20 /* rw: map is being destroyed */ 260 #define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */ 261 #define VM_MAP_VACACHE 0x80 /* ro: use kva cache */ 262 #define VM_MAP_WANTVA 0x100 /* rw: want va */ 263 264 #ifdef _KERNEL 265 struct uvm_mapent_reservation { 266 struct vm_map_entry *umr_entries[2]; 267 int umr_nentries; 268 }; 269 #define UMR_EMPTY(umr) ((umr) == NULL || (umr)->umr_nentries == 0) 270 #define UMR_GETENTRY(umr) ((umr)->umr_entries[--(umr)->umr_nentries]) 271 #define UMR_PUTENTRY(umr, ent) \ 272 (umr)->umr_entries[(umr)->umr_nentries++] = (ent) 273 274 struct uvm_map_args { 275 struct vm_map_entry *uma_prev; 276 277 vaddr_t uma_start; 278 vsize_t uma_size; 279 280 struct uvm_object *uma_uobj; 281 voff_t uma_uoffset; 282 283 uvm_flag_t uma_flags; 284 }; 285 #endif /* _KERNEL */ 286 287 #ifdef _KERNEL 288 #define vm_map_modflags(map, set, clear) \ 289 do { \ 290 simple_lock(&(map)->flags_lock); \ 291 (map)->flags = ((map)->flags | (set)) & ~(clear); \ 292 simple_unlock(&(map)->flags_lock); \ 293 } while (/*CONSTCOND*/ 0) 294 #endif /* _KERNEL */ 295 296 /* 297 * handle inline options 298 */ 299 300 #ifdef UVM_MAP_INLINE 301 #define MAP_INLINE static inline 302 #else 303 #define MAP_INLINE /* nothing */ 304 #endif /* UVM_MAP_INLINE */ 305 306 /* 307 * globals: 308 */ 309 310 #ifdef _KERNEL 311 312 #ifdef PMAP_GROWKERNEL 313 extern vaddr_t uvm_maxkaddr; 314 #endif 315 316 /* 317 * protos: the following prototypes define the interface to vm_map 318 */ 319 320 MAP_INLINE 321 void uvm_map_deallocate(struct vm_map *); 322 323 int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int); 324 void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *, 325 vaddr_t, struct uvm_mapent_reservation *); 326 void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *, 327 vaddr_t, struct uvm_mapent_reservation *); 328 MAP_INLINE 329 struct vm_map *uvm_map_create(pmap_t, vaddr_t, vaddr_t, int); 330 int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t, 331 struct vm_map *, vaddr_t *, int); 332 struct vm_map_entry * 333 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t, 334 vaddr_t *, struct uvm_object *, voff_t, vsize_t, int); 335 int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t, 336 vm_inherit_t); 337 int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int); 338 void uvm_map_init(void); 339 boolean_t uvm_map_lookup_entry(struct vm_map *, vaddr_t, 340 struct vm_map_entry **); 341 MAP_INLINE 342 void uvm_map_reference(struct vm_map *); 343 int uvm_map_replace(struct vm_map *, vaddr_t, vaddr_t, 344 struct vm_map_entry *, int); 345 int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t, 346 vaddr_t *, uvm_flag_t); 347 void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int); 348 void uvm_map_setup_kernel(struct vm_map_kernel *, 349 vaddr_t, vaddr_t, int); 350 MAP_INLINE 351 struct vm_map_kernel * 352 vm_map_to_kernel(struct vm_map *); 353 int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t, 354 struct vm_map *); 355 MAP_INLINE 356 void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int); 357 #define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0) 358 void uvm_unmap_detach(struct vm_map_entry *,int); 359 void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t, 360 struct vm_map_entry **, struct uvm_mapent_reservation *, 361 int); 362 363 int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t, 364 struct uvm_object *, voff_t, vsize_t, uvm_flag_t, 365 struct uvm_map_args *); 366 int uvm_map_enter(struct vm_map *, const struct uvm_map_args *, 367 struct vm_map_entry *); 368 369 int uvm_mapent_reserve(struct vm_map *, 370 struct uvm_mapent_reservation *, int, int); 371 void uvm_mapent_unreserve(struct vm_map *, 372 struct uvm_mapent_reservation *); 373 374 int uvm_mapent_trymerge(struct vm_map *, 375 struct vm_map_entry *, int); 376 #define UVM_MERGE_COPYING 1 377 378 #endif /* _KERNEL */ 379 380 /* 381 * VM map locking operations: 382 * 383 * These operations perform locking on the data portion of the 384 * map. 385 * 386 * vm_map_lock_try: try to lock a map, failing if it is already locked. 387 * 388 * vm_map_lock: acquire an exclusive (write) lock on a map. 389 * 390 * vm_map_lock_read: acquire a shared (read) lock on a map. 391 * 392 * vm_map_unlock: release an exclusive lock on a map. 393 * 394 * vm_map_unlock_read: release a shared lock on a map. 395 * 396 * vm_map_downgrade: downgrade an exclusive lock to a shared lock. 397 * 398 * vm_map_upgrade: upgrade a shared lock to an exclusive lock. 399 * 400 * vm_map_busy: mark a map as busy. 401 * 402 * vm_map_unbusy: clear busy status on a map. 403 * 404 * Note that "intrsafe" maps use only exclusive, spin locks. We simply 405 * use the sleep lock's interlock for this. 406 */ 407 408 #ifdef _KERNEL 409 /* XXX: clean up later */ 410 #include <sys/time.h> 411 #include <sys/proc.h> /* for tsleep(), wakeup() */ 412 #include <sys/systm.h> /* for panic() */ 413 414 static inline boolean_t vm_map_lock_try(struct vm_map *); 415 static inline void vm_map_lock(struct vm_map *); 416 extern const char vmmapbsy[]; 417 418 static inline boolean_t 419 vm_map_lock_try(struct vm_map *map) 420 { 421 boolean_t rv; 422 423 if (map->flags & VM_MAP_INTRSAFE) 424 rv = simple_lock_try(&map->lock.lk_interlock); 425 else { 426 simple_lock(&map->flags_lock); 427 if (map->flags & VM_MAP_BUSY) { 428 simple_unlock(&map->flags_lock); 429 return (FALSE); 430 } 431 rv = (lockmgr(&map->lock, LK_EXCLUSIVE|LK_NOWAIT|LK_INTERLOCK, 432 &map->flags_lock) == 0); 433 } 434 435 if (rv) 436 map->timestamp++; 437 438 return (rv); 439 } 440 441 static inline void 442 vm_map_lock(struct vm_map *map) 443 { 444 int error; 445 446 if (map->flags & VM_MAP_INTRSAFE) { 447 simple_lock(&map->lock.lk_interlock); 448 return; 449 } 450 451 try_again: 452 simple_lock(&map->flags_lock); 453 while (map->flags & VM_MAP_BUSY) { 454 map->flags |= VM_MAP_WANTLOCK; 455 ltsleep(&map->flags, PVM, vmmapbsy, 0, &map->flags_lock); 456 } 457 458 error = lockmgr(&map->lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_INTERLOCK, 459 &map->flags_lock); 460 461 if (error) { 462 KASSERT(error == ENOLCK); 463 goto try_again; 464 } 465 466 (map)->timestamp++; 467 } 468 469 #ifdef DIAGNOSTIC 470 #define vm_map_lock_read(map) \ 471 do { \ 472 if ((map)->flags & VM_MAP_INTRSAFE) \ 473 panic("vm_map_lock_read: intrsafe Map"); \ 474 (void) lockmgr(&(map)->lock, LK_SHARED, NULL); \ 475 } while (/*CONSTCOND*/ 0) 476 #else 477 #define vm_map_lock_read(map) \ 478 (void) lockmgr(&(map)->lock, LK_SHARED, NULL) 479 #endif 480 481 #define vm_map_unlock(map) \ 482 do { \ 483 if ((map)->flags & VM_MAP_INTRSAFE) \ 484 simple_unlock(&(map)->lock.lk_interlock); \ 485 else \ 486 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL); \ 487 } while (/*CONSTCOND*/ 0) 488 489 #define vm_map_unlock_read(map) \ 490 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL) 491 492 #define vm_map_downgrade(map) \ 493 (void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL) 494 495 #ifdef DIAGNOSTIC 496 #define vm_map_upgrade(map) \ 497 do { \ 498 if (lockmgr(&(map)->lock, LK_UPGRADE, NULL) != 0) \ 499 panic("vm_map_upgrade: failed to upgrade lock"); \ 500 } while (/*CONSTCOND*/ 0) 501 #else 502 #define vm_map_upgrade(map) \ 503 (void) lockmgr(&(map)->lock, LK_UPGRADE, NULL) 504 #endif 505 506 #define vm_map_busy(map) \ 507 do { \ 508 simple_lock(&(map)->flags_lock); \ 509 (map)->flags |= VM_MAP_BUSY; \ 510 simple_unlock(&(map)->flags_lock); \ 511 } while (/*CONSTCOND*/ 0) 512 513 #define vm_map_unbusy(map) \ 514 do { \ 515 int oflags; \ 516 \ 517 simple_lock(&(map)->flags_lock); \ 518 oflags = (map)->flags; \ 519 (map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK); \ 520 simple_unlock(&(map)->flags_lock); \ 521 if (oflags & VM_MAP_WANTLOCK) \ 522 wakeup(&(map)->flags); \ 523 } while (/*CONSTCOND*/ 0) 524 525 #endif /* _KERNEL */ 526 527 /* 528 * Functions implemented as macros 529 */ 530 #define vm_map_min(map) ((map)->header.end) 531 #define vm_map_max(map) ((map)->header.start) 532 #define vm_map_setmin(map, v) ((map)->header.end = (v)) 533 #define vm_map_setmax(map, v) ((map)->header.start = (v)) 534 535 #define vm_map_pmap(map) ((map)->pmap) 536 537 #endif /* _UVM_UVM_MAP_H_ */ 538