1 /* $NetBSD: uvm_map.h,v 1.54 2006/05/25 14:27:28 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) 237 238 #include <sys/callback.h> 239 240 struct vm_map_kernel { 241 struct vm_map vmk_map; 242 LIST_HEAD(, uvm_kmapent_hdr) vmk_kentry_free; 243 /* Freelist of map entry */ 244 struct vm_map_entry *vmk_merged_entries; 245 /* Merged entries, kept for later splitting */ 246 247 struct callback_head vmk_reclaim_callback; 248 #if !defined(PMAP_MAP_POOLPAGE) 249 struct pool vmk_vacache; /* kva cache */ 250 struct pool_allocator vmk_vacache_allocator; /* ... and its allocator */ 251 #endif 252 }; 253 #endif /* defined(_KERNEL) */ 254 255 #define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel()) 256 257 /* vm_map flags */ 258 #define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */ 259 #define VM_MAP_INTRSAFE 0x02 /* ro: interrupt safe map */ 260 #define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */ 261 #define VM_MAP_BUSY 0x08 /* rw: map is busy */ 262 #define VM_MAP_WANTLOCK 0x10 /* rw: want to write-lock */ 263 #define VM_MAP_DYING 0x20 /* rw: map is being destroyed */ 264 #define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */ 265 #define VM_MAP_VACACHE 0x80 /* ro: use kva cache */ 266 #define VM_MAP_WANTVA 0x100 /* rw: want va */ 267 268 #ifdef _KERNEL 269 struct uvm_mapent_reservation { 270 struct vm_map_entry *umr_entries[2]; 271 int umr_nentries; 272 }; 273 #define UMR_EMPTY(umr) ((umr) == NULL || (umr)->umr_nentries == 0) 274 #define UMR_GETENTRY(umr) ((umr)->umr_entries[--(umr)->umr_nentries]) 275 #define UMR_PUTENTRY(umr, ent) \ 276 (umr)->umr_entries[(umr)->umr_nentries++] = (ent) 277 278 struct uvm_map_args { 279 struct vm_map_entry *uma_prev; 280 281 vaddr_t uma_start; 282 vsize_t uma_size; 283 284 struct uvm_object *uma_uobj; 285 voff_t uma_uoffset; 286 287 uvm_flag_t uma_flags; 288 }; 289 #endif /* _KERNEL */ 290 291 #ifdef _KERNEL 292 #define vm_map_modflags(map, set, clear) \ 293 do { \ 294 simple_lock(&(map)->flags_lock); \ 295 (map)->flags = ((map)->flags | (set)) & ~(clear); \ 296 simple_unlock(&(map)->flags_lock); \ 297 } while (/*CONSTCOND*/ 0) 298 #endif /* _KERNEL */ 299 300 /* 301 * globals: 302 */ 303 304 #ifdef _KERNEL 305 306 #ifdef PMAP_GROWKERNEL 307 extern vaddr_t uvm_maxkaddr; 308 #endif 309 310 /* 311 * protos: the following prototypes define the interface to vm_map 312 */ 313 314 void uvm_map_deallocate(struct vm_map *); 315 316 int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int); 317 void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *, 318 vaddr_t, struct uvm_mapent_reservation *); 319 void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *, 320 vaddr_t, struct uvm_mapent_reservation *); 321 struct vm_map *uvm_map_create(pmap_t, vaddr_t, vaddr_t, int); 322 int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t, 323 struct vm_map *, vaddr_t *, int); 324 struct vm_map_entry * 325 uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t, 326 vaddr_t *, struct uvm_object *, voff_t, vsize_t, int); 327 int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t, 328 vm_inherit_t); 329 int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int); 330 void uvm_map_init(void); 331 boolean_t uvm_map_lookup_entry(struct vm_map *, vaddr_t, 332 struct vm_map_entry **); 333 void uvm_map_reference(struct vm_map *); 334 int uvm_map_replace(struct vm_map *, vaddr_t, vaddr_t, 335 struct vm_map_entry *, int); 336 int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t, 337 vaddr_t *, uvm_flag_t); 338 void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int); 339 void uvm_map_setup_kernel(struct vm_map_kernel *, 340 vaddr_t, vaddr_t, int); 341 struct vm_map_kernel * 342 vm_map_to_kernel(struct vm_map *); 343 int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t, 344 struct vm_map *); 345 void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int); 346 #define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0) 347 void uvm_unmap_detach(struct vm_map_entry *,int); 348 void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t, 349 struct vm_map_entry **, struct uvm_mapent_reservation *, 350 int); 351 352 int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t, 353 struct uvm_object *, voff_t, vsize_t, uvm_flag_t, 354 struct uvm_map_args *); 355 int uvm_map_enter(struct vm_map *, const struct uvm_map_args *, 356 struct vm_map_entry *); 357 358 int uvm_mapent_reserve(struct vm_map *, 359 struct uvm_mapent_reservation *, int, int); 360 void uvm_mapent_unreserve(struct vm_map *, 361 struct uvm_mapent_reservation *); 362 363 vsize_t uvm_mapent_overhead(vsize_t, int); 364 365 int uvm_mapent_trymerge(struct vm_map *, 366 struct vm_map_entry *, int); 367 #define UVM_MERGE_COPYING 1 368 369 #endif /* _KERNEL */ 370 371 /* 372 * VM map locking operations: 373 * 374 * These operations perform locking on the data portion of the 375 * map. 376 * 377 * vm_map_lock_try: try to lock a map, failing if it is already locked. 378 * 379 * vm_map_lock: acquire an exclusive (write) lock on a map. 380 * 381 * vm_map_lock_read: acquire a shared (read) lock on a map. 382 * 383 * vm_map_unlock: release an exclusive lock on a map. 384 * 385 * vm_map_unlock_read: release a shared lock on a map. 386 * 387 * vm_map_downgrade: downgrade an exclusive lock to a shared lock. 388 * 389 * vm_map_upgrade: upgrade a shared lock to an exclusive lock. 390 * 391 * vm_map_busy: mark a map as busy. 392 * 393 * vm_map_unbusy: clear busy status on a map. 394 * 395 * Note that "intrsafe" maps use only exclusive, spin locks. We simply 396 * use the sleep lock's interlock for this. 397 */ 398 399 #ifdef _KERNEL 400 /* XXX: clean up later */ 401 #include <sys/time.h> 402 #include <sys/proc.h> /* for tsleep(), wakeup() */ 403 #include <sys/systm.h> /* for panic() */ 404 405 static __inline boolean_t vm_map_lock_try(struct vm_map *); 406 static __inline void vm_map_lock(struct vm_map *); 407 extern const char vmmapbsy[]; 408 409 static __inline boolean_t 410 vm_map_lock_try(struct vm_map *map) 411 { 412 boolean_t rv; 413 414 if (map->flags & VM_MAP_INTRSAFE) 415 rv = simple_lock_try(&map->lock.lk_interlock); 416 else { 417 simple_lock(&map->flags_lock); 418 if (map->flags & VM_MAP_BUSY) { 419 simple_unlock(&map->flags_lock); 420 return (FALSE); 421 } 422 rv = (lockmgr(&map->lock, LK_EXCLUSIVE|LK_NOWAIT|LK_INTERLOCK, 423 &map->flags_lock) == 0); 424 } 425 426 if (rv) 427 map->timestamp++; 428 429 return (rv); 430 } 431 432 static __inline void 433 vm_map_lock(struct vm_map *map) 434 { 435 int error; 436 437 if (map->flags & VM_MAP_INTRSAFE) { 438 simple_lock(&map->lock.lk_interlock); 439 return; 440 } 441 442 try_again: 443 simple_lock(&map->flags_lock); 444 while (map->flags & VM_MAP_BUSY) { 445 map->flags |= VM_MAP_WANTLOCK; 446 ltsleep(&map->flags, PVM, vmmapbsy, 0, &map->flags_lock); 447 } 448 449 error = lockmgr(&map->lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_INTERLOCK, 450 &map->flags_lock); 451 452 if (error) { 453 KASSERT(error == ENOLCK); 454 goto try_again; 455 } 456 457 (map)->timestamp++; 458 } 459 460 #ifdef DIAGNOSTIC 461 #define vm_map_lock_read(map) \ 462 do { \ 463 if ((map)->flags & VM_MAP_INTRSAFE) \ 464 panic("vm_map_lock_read: intrsafe Map"); \ 465 (void) lockmgr(&(map)->lock, LK_SHARED, NULL); \ 466 } while (/*CONSTCOND*/ 0) 467 #else 468 #define vm_map_lock_read(map) \ 469 (void) lockmgr(&(map)->lock, LK_SHARED, NULL) 470 #endif 471 472 #define vm_map_unlock(map) \ 473 do { \ 474 if ((map)->flags & VM_MAP_INTRSAFE) \ 475 simple_unlock(&(map)->lock.lk_interlock); \ 476 else \ 477 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL); \ 478 } while (/*CONSTCOND*/ 0) 479 480 #define vm_map_unlock_read(map) \ 481 (void) lockmgr(&(map)->lock, LK_RELEASE, NULL) 482 483 #define vm_map_downgrade(map) \ 484 (void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL) 485 486 #ifdef DIAGNOSTIC 487 #define vm_map_upgrade(map) \ 488 do { \ 489 if (lockmgr(&(map)->lock, LK_UPGRADE, NULL) != 0) \ 490 panic("vm_map_upgrade: failed to upgrade lock"); \ 491 } while (/*CONSTCOND*/ 0) 492 #else 493 #define vm_map_upgrade(map) \ 494 (void) lockmgr(&(map)->lock, LK_UPGRADE, NULL) 495 #endif 496 497 #define vm_map_busy(map) \ 498 do { \ 499 simple_lock(&(map)->flags_lock); \ 500 (map)->flags |= VM_MAP_BUSY; \ 501 simple_unlock(&(map)->flags_lock); \ 502 } while (/*CONSTCOND*/ 0) 503 504 #define vm_map_unbusy(map) \ 505 do { \ 506 int oflags; \ 507 \ 508 simple_lock(&(map)->flags_lock); \ 509 oflags = (map)->flags; \ 510 (map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK); \ 511 simple_unlock(&(map)->flags_lock); \ 512 if (oflags & VM_MAP_WANTLOCK) \ 513 wakeup(&(map)->flags); \ 514 } while (/*CONSTCOND*/ 0) 515 516 boolean_t vm_map_starved_p(struct vm_map *); 517 518 #endif /* _KERNEL */ 519 520 /* 521 * Functions implemented as macros 522 */ 523 #define vm_map_min(map) ((map)->header.end) 524 #define vm_map_max(map) ((map)->header.start) 525 #define vm_map_setmin(map, v) ((map)->header.end = (v)) 526 #define vm_map_setmax(map, v) ((map)->header.start = (v)) 527 528 #define vm_map_pmap(map) ((map)->pmap) 529 530 #endif /* _UVM_UVM_MAP_H_ */ 531