1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93 35 * 36 * 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 * 62 * $FreeBSD$ 63 */ 64 65 /* 66 * Resident memory system definitions. 67 */ 68 69 #ifndef _VM_PAGE_ 70 #define _VM_PAGE_ 71 72 #include <vm/pmap.h> 73 74 /* 75 * Management of resident (logical) pages. 76 * 77 * A small structure is kept for each resident 78 * page, indexed by page number. Each structure 79 * is an element of several collections: 80 * 81 * A radix tree used to quickly 82 * perform object/offset lookups 83 * 84 * A list of all pages for a given object, 85 * so they can be quickly deactivated at 86 * time of deallocation. 87 * 88 * An ordered list of pages due for pageout. 89 * 90 * In addition, the structure contains the object 91 * and offset to which this page belongs (for pageout), 92 * and sundry status bits. 93 * 94 * In general, operations on this structure's mutable fields are 95 * synchronized using either one of or a combination of locks. If a 96 * field is annotated with two of these locks then holding either is 97 * sufficient for read access but both are required for write access. 98 * The physical address of a page is used to select its page lock from 99 * a pool. The queue lock for a page depends on the value of its queue 100 * field and is described in detail below. 101 * 102 * The following annotations are possible: 103 * (A) the field is atomic and may require additional synchronization. 104 * (B) the page busy lock. 105 * (C) the field is immutable. 106 * (F) the per-domain lock for the free queues 107 * (M) Machine dependent, defined by pmap layer. 108 * (O) the object that the page belongs to. 109 * (P) the page lock. 110 * (Q) the page's queue lock. 111 * 112 * The busy lock is an embedded reader-writer lock that protects the 113 * page's contents and identity (i.e., its <object, pindex> tuple) as 114 * well as certain valid/dirty modifications. To avoid bloating the 115 * the page structure, the busy lock lacks some of the features available 116 * the kernel's general-purpose synchronization primitives. As a result, 117 * busy lock ordering rules are not verified, lock recursion is not 118 * detected, and an attempt to xbusy a busy page or sbusy an xbusy page 119 * results will trigger a panic rather than causing the thread to block. 120 * vm_page_sleep_if_busy() can be used to sleep until the page's busy 121 * state changes, after which the caller must re-lookup the page and 122 * re-evaluate its state. vm_page_busy_acquire() will block until 123 * the lock is acquired. 124 * 125 * The valid field is protected by the page busy lock (B) and object 126 * lock (O). Transitions from invalid to valid are generally done 127 * via I/O or zero filling and do not require the object lock. 128 * These must be protected with the busy lock to prevent page-in or 129 * creation races. Page invalidation generally happens as a result 130 * of truncate or msync. When invalidated, pages must not be present 131 * in pmap and must hold the object lock to prevent concurrent 132 * speculative read-only mappings that do not require busy. I/O 133 * routines may check for validity without a lock if they are prepared 134 * to handle invalidation races with higher level locks (vnode) or are 135 * unconcerned with races so long as they hold a reference to prevent 136 * recycling. When a valid bit is set while holding a shared busy 137 * lock (A) atomic operations are used to protect against concurrent 138 * modification. 139 * 140 * In contrast, the synchronization of accesses to the page's 141 * dirty field is a mix of machine dependent (M) and busy (B). In 142 * the machine-independent layer, the page busy must be held to 143 * operate on the field. However, the pmap layer is permitted to 144 * set all bits within the field without holding that lock. If the 145 * underlying architecture does not support atomic read-modify-write 146 * operations on the field's type, then the machine-independent 147 * layer uses a 32-bit atomic on the aligned 32-bit word that 148 * contains the dirty field. In the machine-independent layer, 149 * the implementation of read-modify-write operations on the 150 * field is encapsulated in vm_page_clear_dirty_mask(). An 151 * exclusive busy lock combined with pmap_remove_{write/all}() is the 152 * only way to ensure a page can not become dirty. I/O generally 153 * removes the page from pmap to ensure exclusive access and atomic 154 * writes. 155 * 156 * The ref_count field tracks references to the page. References that 157 * prevent the page from being reclaimable are called wirings and are 158 * counted in the low bits of ref_count. The containing object's 159 * reference, if one exists, is counted using the VPRC_OBJREF bit in the 160 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to 161 * atomically check for wirings and prevent new wirings via 162 * pmap_extract_and_hold(). When a page belongs to an object, it may be 163 * wired only when the object is locked, or the page is busy, or by 164 * pmap_extract_and_hold(). As a result, if the object is locked and the 165 * page is not busy (or is exclusively busied by the current thread), and 166 * the page is unmapped, its wire count will not increase. The ref_count 167 * field is updated using atomic operations in most cases, except when it 168 * is known that no other references to the page exist, such as in the page 169 * allocator. A page may be present in the page queues, or even actively 170 * scanned by the page daemon, without an explicitly counted referenced. 171 * The page daemon must therefore handle the possibility of a concurrent 172 * free of the page. 173 * 174 * The queue state of a page consists of the queue and act_count fields of 175 * its atomically updated state, and the subset of atomic flags specified 176 * by PGA_QUEUE_STATE_MASK. The queue field contains the page's page queue 177 * index, or PQ_NONE if it does not belong to a page queue. To modify the 178 * queue field, the page queue lock corresponding to the old value must be 179 * held, unless that value is PQ_NONE, in which case the queue index must 180 * be updated using an atomic RMW operation. There is one exception to 181 * this rule: the page daemon may transition the queue field from 182 * PQ_INACTIVE to PQ_NONE immediately prior to freeing the page during an 183 * inactive queue scan. At that point the page is already dequeued and no 184 * other references to that vm_page structure can exist. The PGA_ENQUEUED 185 * flag, when set, indicates that the page structure is physically inserted 186 * into the queue corresponding to the page's queue index, and may only be 187 * set or cleared with the corresponding page queue lock held. 188 * 189 * To avoid contention on page queue locks, page queue operations (enqueue, 190 * dequeue, requeue) are batched using fixed-size per-CPU queues. A 191 * deferred operation is requested by setting one of the flags in 192 * PGA_QUEUE_OP_MASK and inserting an entry into a batch queue. When a 193 * queue is full, an attempt to insert a new entry will lock the page 194 * queues and trigger processing of the pending entries. The 195 * type-stability of vm_page structures is crucial to this scheme since the 196 * processing of entries in a given batch queue may be deferred 197 * indefinitely. In particular, a page may be freed with pending batch 198 * queue entries. The page queue operation flags must be set using atomic 199 * RWM operations. 200 */ 201 202 #if PAGE_SIZE == 4096 203 #define VM_PAGE_BITS_ALL 0xffu 204 typedef uint8_t vm_page_bits_t; 205 #elif PAGE_SIZE == 8192 206 #define VM_PAGE_BITS_ALL 0xffffu 207 typedef uint16_t vm_page_bits_t; 208 #elif PAGE_SIZE == 16384 209 #define VM_PAGE_BITS_ALL 0xffffffffu 210 typedef uint32_t vm_page_bits_t; 211 #elif PAGE_SIZE == 32768 212 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 213 typedef uint64_t vm_page_bits_t; 214 #endif 215 216 typedef union vm_page_astate { 217 struct { 218 uint16_t flags; 219 uint8_t queue; 220 uint8_t act_count; 221 }; 222 uint32_t _bits; 223 } vm_page_astate_t; 224 225 struct vm_page { 226 union { 227 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */ 228 struct { 229 SLIST_ENTRY(vm_page) ss; /* private slists */ 230 } s; 231 struct { 232 u_long p; 233 u_long v; 234 } memguard; 235 struct { 236 void *slab; 237 void *zone; 238 } uma; 239 } plinks; 240 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 241 vm_object_t object; /* which object am I in (O) */ 242 vm_pindex_t pindex; /* offset into object (O,P) */ 243 vm_paddr_t phys_addr; /* physical address of page (C) */ 244 struct md_page md; /* machine dependent stuff */ 245 u_int ref_count; /* page references (A) */ 246 volatile u_int busy_lock; /* busy owners lock */ 247 union vm_page_astate a; /* state accessed atomically */ 248 uint8_t order; /* index of the buddy queue (F) */ 249 uint8_t pool; /* vm_phys freepool index (F) */ 250 uint8_t flags; /* page PG_* flags (P) */ 251 uint8_t oflags; /* page VPO_* flags (O) */ 252 int8_t psind; /* pagesizes[] index (O) */ 253 int8_t segind; /* vm_phys segment index (C) */ 254 /* NOTE that these must support one bit per DEV_BSIZE in a page */ 255 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 256 vm_page_bits_t valid; /* valid DEV_BSIZE chunk map (O,B) */ 257 vm_page_bits_t dirty; /* dirty DEV_BSIZE chunk map (M,B) */ 258 }; 259 260 /* 261 * Special bits used in the ref_count field. 262 * 263 * ref_count is normally used to count wirings that prevent the page from being 264 * reclaimed, but also supports several special types of references that do not 265 * prevent reclamation. Accesses to the ref_count field must be atomic unless 266 * the page is unallocated. 267 * 268 * VPRC_OBJREF is the reference held by the containing object. It can set or 269 * cleared only when the corresponding object's write lock is held. 270 * 271 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while 272 * attempting to tear down all mappings of a given page. The page lock and 273 * object write lock must both be held in order to set or clear this bit. 274 */ 275 #define VPRC_BLOCKED 0x40000000u /* mappings are being removed */ 276 #define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */ 277 #define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF)) 278 #define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF)) 279 280 /* 281 * Page flags stored in oflags: 282 * 283 * Access to these page flags is synchronized by the lock on the object 284 * containing the page (O). 285 * 286 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG) 287 * indicates that the page is not under PV management but 288 * otherwise should be treated as a normal page. Pages not 289 * under PV management cannot be paged out via the 290 * object/vm_page_t because there is no knowledge of their pte 291 * mappings, and such pages are also not on any PQ queue. 292 * 293 */ 294 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */ 295 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */ 296 #define VPO_UNMANAGED 0x04 /* no PV management for page */ 297 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */ 298 299 /* 300 * Busy page implementation details. 301 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation, 302 * even if the support for owner identity is removed because of size 303 * constraints. Checks on lock recursion are then not possible, while the 304 * lock assertions effectiveness is someway reduced. 305 */ 306 #define VPB_BIT_SHARED 0x01 307 #define VPB_BIT_EXCLUSIVE 0x02 308 #define VPB_BIT_WAITERS 0x04 309 #define VPB_BIT_FLAGMASK \ 310 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS) 311 312 #define VPB_SHARERS_SHIFT 3 313 #define VPB_SHARERS(x) \ 314 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT) 315 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED) 316 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT) 317 318 #define VPB_SINGLE_EXCLUSIVE VPB_BIT_EXCLUSIVE 319 #ifdef INVARIANTS 320 #define VPB_CURTHREAD_EXCLUSIVE \ 321 (VPB_BIT_EXCLUSIVE | ((u_int)(uintptr_t)curthread & ~VPB_BIT_FLAGMASK)) 322 #else 323 #define VPB_CURTHREAD_EXCLUSIVE VPB_SINGLE_EXCLUSIVE 324 #endif 325 326 #define VPB_UNBUSIED VPB_SHARERS_WORD(0) 327 328 /* Freed lock blocks both shared and exclusive. */ 329 #define VPB_FREED (0xffffffff - VPB_BIT_SHARED) 330 331 #define PQ_NONE 255 332 #define PQ_INACTIVE 0 333 #define PQ_ACTIVE 1 334 #define PQ_LAUNDRY 2 335 #define PQ_UNSWAPPABLE 3 336 #define PQ_COUNT 4 337 338 #ifndef VM_PAGE_HAVE_PGLIST 339 TAILQ_HEAD(pglist, vm_page); 340 #define VM_PAGE_HAVE_PGLIST 341 #endif 342 SLIST_HEAD(spglist, vm_page); 343 344 #ifdef _KERNEL 345 extern vm_page_t bogus_page; 346 #endif /* _KERNEL */ 347 348 extern struct mtx_padalign pa_lock[]; 349 350 #if defined(__arm__) 351 #define PDRSHIFT PDR_SHIFT 352 #elif !defined(PDRSHIFT) 353 #define PDRSHIFT 21 354 #endif 355 356 #define pa_index(pa) ((pa) >> PDRSHIFT) 357 #define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT])) 358 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa))) 359 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa)) 360 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa)) 361 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa)) 362 #define PA_UNLOCK_COND(pa) \ 363 do { \ 364 if ((pa) != 0) { \ 365 PA_UNLOCK((pa)); \ 366 (pa) = 0; \ 367 } \ 368 } while (0) 369 370 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a)) 371 372 #if defined(KLD_MODULE) && !defined(KLD_TIED) 373 #define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE) 374 #define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE) 375 #define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE) 376 #else /* !KLD_MODULE */ 377 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m)))) 378 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m))) 379 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m))) 380 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m))) 381 #endif 382 #if defined(INVARIANTS) 383 #define vm_page_assert_locked(m) \ 384 vm_page_assert_locked_KBI((m), __FILE__, __LINE__) 385 #define vm_page_lock_assert(m, a) \ 386 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__) 387 #else 388 #define vm_page_assert_locked(m) 389 #define vm_page_lock_assert(m, a) 390 #endif 391 392 /* 393 * The vm_page's aflags are updated using atomic operations. To set or clear 394 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear() 395 * must be used. Neither these flags nor these functions are part of the KBI. 396 * 397 * PGA_REFERENCED may be cleared only if the page is locked. It is set by 398 * both the MI and MD VM layers. However, kernel loadable modules should not 399 * directly set this flag. They should call vm_page_reference() instead. 400 * 401 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). 402 * When it does so, the object must be locked, or the page must be 403 * exclusive busied. The MI VM layer must never access this flag 404 * directly. Instead, it should call pmap_page_is_write_mapped(). 405 * 406 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has 407 * at least one executable mapping. It is not consumed by the MI VM layer. 408 * 409 * PGA_NOSYNC must be set and cleared with the page busy lock held. 410 * 411 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed 412 * from a page queue, respectively. It determines whether the plinks.q field 413 * of the page is valid. To set or clear this flag, the queue lock for the 414 * page must be held: the page queue lock corresponding to the page's "queue" 415 * field if its value is not PQ_NONE, and the page lock otherwise. 416 * 417 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page 418 * queue, and cleared when the dequeue request is processed. A page may 419 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue 420 * is requested after the page is scheduled to be enqueued but before it is 421 * actually inserted into the page queue. For allocated pages, the page lock 422 * must be held to set this flag, but it may be set by vm_page_free_prep() 423 * without the page lock held. The page queue lock must be held to clear the 424 * PGA_DEQUEUE flag. 425 * 426 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued 427 * in its page queue. The page lock must be held to set this flag, and the 428 * queue lock for the page must be held to clear it. 429 * 430 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of 431 * the inactive queue, thus bypassing LRU. The page lock must be held to 432 * set this flag, and the queue lock for the page must be held to clear it. 433 * 434 * PGA_SWAP_FREE is used to defer freeing swap space to the pageout daemon 435 * when the context that dirties the page does not have the object write lock 436 * held. 437 */ 438 #define PGA_WRITEABLE 0x0001 /* page may be mapped writeable */ 439 #define PGA_REFERENCED 0x0002 /* page has been referenced */ 440 #define PGA_EXECUTABLE 0x0004 /* page may be mapped executable */ 441 #define PGA_ENQUEUED 0x0008 /* page is enqueued in a page queue */ 442 #define PGA_DEQUEUE 0x0010 /* page is due to be dequeued */ 443 #define PGA_REQUEUE 0x0020 /* page is due to be requeued */ 444 #define PGA_REQUEUE_HEAD 0x0040 /* page requeue should bypass LRU */ 445 #define PGA_NOSYNC 0x0080 /* do not collect for syncer */ 446 #define PGA_SWAP_FREE 0x0100 /* page with swap space was dirtied */ 447 #define PGA_SWAP_SPACE 0x0200 /* page has allocated swap space */ 448 449 #define PGA_QUEUE_OP_MASK (PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD) 450 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_QUEUE_OP_MASK) 451 452 /* 453 * Page flags. If changed at any other time than page allocation or 454 * freeing, the modification must be protected by the vm_page lock. 455 * 456 * The PG_PCPU_CACHE flag is set at allocation time if the page was 457 * allocated from a per-CPU cache. It is cleared the next time that the 458 * page is allocated from the physical memory allocator. 459 */ 460 #define PG_PCPU_CACHE 0x01 /* was allocated from per-CPU caches */ 461 #define PG_FICTITIOUS 0x02 /* physical page doesn't exist */ 462 #define PG_ZERO 0x04 /* page is zeroed */ 463 #define PG_MARKER 0x08 /* special queue marker page */ 464 #define PG_NODUMP 0x10 /* don't include this page in a dump */ 465 466 /* 467 * Misc constants. 468 */ 469 #define ACT_DECLINE 1 470 #define ACT_ADVANCE 3 471 #define ACT_INIT 5 472 #define ACT_MAX 64 473 474 #ifdef _KERNEL 475 476 #include <sys/systm.h> 477 478 #include <machine/atomic.h> 479 480 /* 481 * Each pageable resident page falls into one of five lists: 482 * 483 * free 484 * Available for allocation now. 485 * 486 * inactive 487 * Low activity, candidates for reclamation. 488 * This list is approximately LRU ordered. 489 * 490 * laundry 491 * This is the list of pages that should be 492 * paged out next. 493 * 494 * unswappable 495 * Dirty anonymous pages that cannot be paged 496 * out because no swap device is configured. 497 * 498 * active 499 * Pages that are "active", i.e., they have been 500 * recently referenced. 501 * 502 */ 503 504 extern vm_page_t vm_page_array; /* First resident page in table */ 505 extern long vm_page_array_size; /* number of vm_page_t's */ 506 extern long first_page; /* first physical page number */ 507 508 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 509 510 /* 511 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory 512 * page to which the given physical address belongs. The correct vm_page_t 513 * object is returned for addresses that are not page-aligned. 514 */ 515 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 516 517 /* 518 * Page allocation parameters for vm_page for the functions 519 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and 520 * vm_page_alloc_freelist(). Some functions support only a subset 521 * of the flags, and ignore others, see the flags legend. 522 * 523 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*() 524 * and the vm_page_grab*() functions. See these functions for details. 525 * 526 * Bits 0 - 1 define class. 527 * Bits 2 - 15 dedicated for flags. 528 * Legend: 529 * (a) - vm_page_alloc() supports the flag. 530 * (c) - vm_page_alloc_contig() supports the flag. 531 * (f) - vm_page_alloc_freelist() supports the flag. 532 * (g) - vm_page_grab() supports the flag. 533 * (p) - vm_page_grab_pages() supports the flag. 534 * Bits above 15 define the count of additional pages that the caller 535 * intends to allocate. 536 */ 537 #define VM_ALLOC_NORMAL 0 538 #define VM_ALLOC_INTERRUPT 1 539 #define VM_ALLOC_SYSTEM 2 540 #define VM_ALLOC_CLASS_MASK 3 541 #define VM_ALLOC_WAITOK 0x0008 /* (acf) Sleep and retry */ 542 #define VM_ALLOC_WAITFAIL 0x0010 /* (acf) Sleep and return error */ 543 #define VM_ALLOC_WIRED 0x0020 /* (acfgp) Allocate a wired page */ 544 #define VM_ALLOC_ZERO 0x0040 /* (acfgp) Allocate a prezeroed page */ 545 #define VM_ALLOC_NOOBJ 0x0100 /* (acg) No associated object */ 546 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */ 547 #define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */ 548 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */ 549 #define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */ 550 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */ 551 #define VM_ALLOC_NOWAIT 0x8000 /* (acfgp) Do not sleep */ 552 #define VM_ALLOC_COUNT_SHIFT 16 553 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) 554 555 #ifdef M_NOWAIT 556 static inline int 557 malloc2vm_flags(int malloc_flags) 558 { 559 int pflags; 560 561 KASSERT((malloc_flags & M_USE_RESERVE) == 0 || 562 (malloc_flags & M_NOWAIT) != 0, 563 ("M_USE_RESERVE requires M_NOWAIT")); 564 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT : 565 VM_ALLOC_SYSTEM; 566 if ((malloc_flags & M_ZERO) != 0) 567 pflags |= VM_ALLOC_ZERO; 568 if ((malloc_flags & M_NODUMP) != 0) 569 pflags |= VM_ALLOC_NODUMP; 570 if ((malloc_flags & M_NOWAIT)) 571 pflags |= VM_ALLOC_NOWAIT; 572 if ((malloc_flags & M_WAITOK)) 573 pflags |= VM_ALLOC_WAITOK; 574 return (pflags); 575 } 576 #endif 577 578 /* 579 * Predicates supported by vm_page_ps_test(): 580 * 581 * PS_ALL_DIRTY is true only if the entire (super)page is dirty. 582 * However, it can be spuriously false when the (super)page has become 583 * dirty in the pmap but that information has not been propagated to the 584 * machine-independent layer. 585 */ 586 #define PS_ALL_DIRTY 0x1 587 #define PS_ALL_VALID 0x2 588 #define PS_NONE_BUSY 0x4 589 590 bool vm_page_busy_acquire(vm_page_t m, int allocflags); 591 void vm_page_busy_downgrade(vm_page_t m); 592 int vm_page_busy_tryupgrade(vm_page_t m); 593 void vm_page_busy_sleep(vm_page_t m, const char *msg, bool nonshared); 594 void vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, 595 vm_pindex_t pindex, const char *wmesg, bool nonshared); 596 void vm_page_free(vm_page_t m); 597 void vm_page_free_zero(vm_page_t m); 598 599 void vm_page_activate (vm_page_t); 600 void vm_page_advise(vm_page_t m, int advice); 601 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int); 602 vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int); 603 vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t); 604 vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int, 605 vm_page_t); 606 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 607 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 608 vm_paddr_t boundary, vm_memattr_t memattr); 609 vm_page_t vm_page_alloc_contig_domain(vm_object_t object, 610 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low, 611 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 612 vm_memattr_t memattr); 613 vm_page_t vm_page_alloc_freelist(int, int); 614 vm_page_t vm_page_alloc_freelist_domain(int, int, int); 615 void vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set); 616 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose); 617 vm_page_t vm_page_grab(vm_object_t, vm_pindex_t, int); 618 vm_page_t vm_page_grab_unlocked(vm_object_t, vm_pindex_t, int); 619 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 620 vm_page_t *ma, int count); 621 int vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 622 int allocflags, vm_page_t *ma, int count); 623 int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 624 int allocflags); 625 int vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 626 vm_pindex_t pindex, int allocflags); 627 void vm_page_deactivate(vm_page_t); 628 void vm_page_deactivate_noreuse(vm_page_t); 629 void vm_page_dequeue(vm_page_t m); 630 void vm_page_dequeue_deferred(vm_page_t m); 631 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t); 632 void vm_page_free_invalid(vm_page_t); 633 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 634 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 635 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 636 void vm_page_invalid(vm_page_t m); 637 void vm_page_launder(vm_page_t m); 638 vm_page_t vm_page_lookup(vm_object_t, vm_pindex_t); 639 vm_page_t vm_page_next(vm_page_t m); 640 void vm_page_pqbatch_drain(void); 641 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue); 642 bool vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, 643 vm_page_astate_t new); 644 vm_page_t vm_page_prev(vm_page_t m); 645 bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m); 646 void vm_page_putfake(vm_page_t m); 647 void vm_page_readahead_finish(vm_page_t m); 648 bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, 649 vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 650 bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 651 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 652 void vm_page_reference(vm_page_t m); 653 #define VPR_TRYFREE 0x01 654 #define VPR_NOREUSE 0x02 655 void vm_page_release(vm_page_t m, int flags); 656 void vm_page_release_locked(vm_page_t m, int flags); 657 vm_page_t vm_page_relookup(vm_object_t, vm_pindex_t); 658 bool vm_page_remove(vm_page_t); 659 bool vm_page_remove_xbusy(vm_page_t); 660 int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t); 661 void vm_page_replace(vm_page_t mnew, vm_object_t object, 662 vm_pindex_t pindex, vm_page_t mold); 663 int vm_page_sbusied(vm_page_t m); 664 vm_page_t vm_page_scan_contig(u_long npages, vm_page_t m_start, 665 vm_page_t m_end, u_long alignment, vm_paddr_t boundary, int options); 666 vm_page_bits_t vm_page_set_dirty(vm_page_t m); 667 void vm_page_set_valid_range(vm_page_t m, int base, int size); 668 int vm_page_sleep_if_busy(vm_page_t m, const char *msg); 669 int vm_page_sleep_if_xbusy(vm_page_t m, const char *msg); 670 vm_offset_t vm_page_startup(vm_offset_t vaddr); 671 void vm_page_sunbusy(vm_page_t m); 672 bool vm_page_try_remove_all(vm_page_t m); 673 bool vm_page_try_remove_write(vm_page_t m); 674 int vm_page_trysbusy(vm_page_t m); 675 int vm_page_tryxbusy(vm_page_t m); 676 void vm_page_unhold_pages(vm_page_t *ma, int count); 677 void vm_page_unswappable(vm_page_t m); 678 void vm_page_unwire(vm_page_t m, uint8_t queue); 679 bool vm_page_unwire_noq(vm_page_t m); 680 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 681 void vm_page_wire(vm_page_t); 682 bool vm_page_wire_mapped(vm_page_t m); 683 void vm_page_xunbusy_hard(vm_page_t m); 684 void vm_page_xunbusy_hard_unchecked(vm_page_t m); 685 void vm_page_set_validclean (vm_page_t, int, int); 686 void vm_page_clear_dirty(vm_page_t, int, int); 687 void vm_page_set_invalid(vm_page_t, int, int); 688 void vm_page_valid(vm_page_t m); 689 int vm_page_is_valid(vm_page_t, int, int); 690 void vm_page_test_dirty(vm_page_t); 691 vm_page_bits_t vm_page_bits(int base, int size); 692 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 693 void vm_page_free_pages_toq(struct spglist *free, bool update_wire_count); 694 695 void vm_page_dirty_KBI(vm_page_t m); 696 void vm_page_lock_KBI(vm_page_t m, const char *file, int line); 697 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line); 698 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line); 699 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 700 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line); 701 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line); 702 #endif 703 704 #define vm_page_assert_busied(m) \ 705 KASSERT(vm_page_busied(m), \ 706 ("vm_page_assert_busied: page %p not busy @ %s:%d", \ 707 (m), __FILE__, __LINE__)) 708 709 #define vm_page_assert_sbusied(m) \ 710 KASSERT(vm_page_sbusied(m), \ 711 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \ 712 (m), __FILE__, __LINE__)) 713 714 #define vm_page_assert_unbusied(m) \ 715 KASSERT((m->busy_lock & ~VPB_BIT_WAITERS) != \ 716 VPB_CURTHREAD_EXCLUSIVE, \ 717 ("vm_page_assert_xbusied: page %p busy_lock %#x owned" \ 718 " by me @ %s:%d", \ 719 (m), (m)->busy_lock, __FILE__, __LINE__)); \ 720 721 #define vm_page_assert_xbusied_unchecked(m) do { \ 722 KASSERT(vm_page_xbusied(m), \ 723 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \ 724 (m), __FILE__, __LINE__)); \ 725 } while (0) 726 #define vm_page_assert_xbusied(m) do { \ 727 vm_page_assert_xbusied_unchecked(m); \ 728 KASSERT((m->busy_lock & ~VPB_BIT_WAITERS) == \ 729 VPB_CURTHREAD_EXCLUSIVE, \ 730 ("vm_page_assert_xbusied: page %p busy_lock %#x not owned" \ 731 " by me @ %s:%d", \ 732 (m), (m)->busy_lock, __FILE__, __LINE__)); \ 733 } while (0) 734 735 #define vm_page_busied(m) \ 736 ((m)->busy_lock != VPB_UNBUSIED) 737 738 #define vm_page_sbusy(m) do { \ 739 if (!vm_page_trysbusy(m)) \ 740 panic("%s: page %p failed shared busying", __func__, \ 741 (m)); \ 742 } while (0) 743 744 #define vm_page_xbusied(m) \ 745 (((m)->busy_lock & VPB_SINGLE_EXCLUSIVE) != 0) 746 747 #define vm_page_busy_freed(m) \ 748 ((m)->busy_lock == VPB_FREED) 749 750 #define vm_page_xbusy(m) do { \ 751 if (!vm_page_tryxbusy(m)) \ 752 panic("%s: page %p failed exclusive busying", __func__, \ 753 (m)); \ 754 } while (0) 755 756 /* Note: page m's lock must not be owned by the caller. */ 757 #define vm_page_xunbusy(m) do { \ 758 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 759 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 760 vm_page_xunbusy_hard(m); \ 761 } while (0) 762 #define vm_page_xunbusy_unchecked(m) do { \ 763 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 764 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 765 vm_page_xunbusy_hard_unchecked(m); \ 766 } while (0) 767 768 #ifdef INVARIANTS 769 void vm_page_object_busy_assert(vm_page_t m); 770 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) vm_page_object_busy_assert(m) 771 void vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits); 772 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \ 773 vm_page_assert_pga_writeable(m, bits) 774 #define vm_page_xbusy_claim(m) do { \ 775 vm_page_assert_xbusied_unchecked((m)); \ 776 (m)->busy_lock = VPB_CURTHREAD_EXCLUSIVE; \ 777 } while (0) 778 #else 779 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) (void)0 780 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0 781 #define vm_page_xbusy_claim(m) 782 #endif 783 784 #if BYTE_ORDER == BIG_ENDIAN 785 #define VM_PAGE_AFLAG_SHIFT 16 786 #else 787 #define VM_PAGE_AFLAG_SHIFT 0 788 #endif 789 790 /* 791 * Load a snapshot of a page's 32-bit atomic state. 792 */ 793 static inline vm_page_astate_t 794 vm_page_astate_load(vm_page_t m) 795 { 796 vm_page_astate_t a; 797 798 a._bits = atomic_load_32(&m->a._bits); 799 return (a); 800 } 801 802 /* 803 * Atomically compare and set a page's atomic state. 804 */ 805 static inline bool 806 vm_page_astate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 807 { 808 809 KASSERT(new.queue == PQ_INACTIVE || (new.flags & PGA_REQUEUE_HEAD) == 0, 810 ("%s: invalid head requeue request for page %p", __func__, m)); 811 KASSERT((new.flags & PGA_ENQUEUED) == 0 || new.queue != PQ_NONE, 812 ("%s: setting PGA_ENQUEUED with PQ_NONE in page %p", __func__, m)); 813 KASSERT(new._bits != old->_bits, 814 ("%s: bits are unchanged", __func__)); 815 816 return (atomic_fcmpset_32(&m->a._bits, &old->_bits, new._bits) != 0); 817 } 818 819 /* 820 * Clear the given bits in the specified page. 821 */ 822 static inline void 823 vm_page_aflag_clear(vm_page_t m, uint16_t bits) 824 { 825 uint32_t *addr, val; 826 827 /* 828 * Access the whole 32-bit word containing the aflags field with an 829 * atomic update. Parallel non-atomic updates to the other fields 830 * within this word are handled properly by the atomic update. 831 */ 832 addr = (void *)&m->a; 833 val = bits << VM_PAGE_AFLAG_SHIFT; 834 atomic_clear_32(addr, val); 835 } 836 837 /* 838 * Set the given bits in the specified page. 839 */ 840 static inline void 841 vm_page_aflag_set(vm_page_t m, uint16_t bits) 842 { 843 uint32_t *addr, val; 844 845 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits); 846 847 /* 848 * Access the whole 32-bit word containing the aflags field with an 849 * atomic update. Parallel non-atomic updates to the other fields 850 * within this word are handled properly by the atomic update. 851 */ 852 addr = (void *)&m->a; 853 val = bits << VM_PAGE_AFLAG_SHIFT; 854 atomic_set_32(addr, val); 855 } 856 857 /* 858 * vm_page_dirty: 859 * 860 * Set all bits in the page's dirty field. 861 * 862 * The object containing the specified page must be locked if the 863 * call is made from the machine-independent layer. 864 * 865 * See vm_page_clear_dirty_mask(). 866 */ 867 static __inline void 868 vm_page_dirty(vm_page_t m) 869 { 870 871 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */ 872 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS) 873 vm_page_dirty_KBI(m); 874 #else 875 m->dirty = VM_PAGE_BITS_ALL; 876 #endif 877 } 878 879 /* 880 * vm_page_undirty: 881 * 882 * Set page to not be dirty. Note: does not clear pmap modify bits 883 */ 884 static __inline void 885 vm_page_undirty(vm_page_t m) 886 { 887 888 VM_PAGE_OBJECT_BUSY_ASSERT(m); 889 m->dirty = 0; 890 } 891 892 static inline uint8_t 893 _vm_page_queue(vm_page_astate_t as) 894 { 895 896 if ((as.flags & PGA_DEQUEUE) != 0) 897 return (PQ_NONE); 898 return (as.queue); 899 } 900 901 /* 902 * vm_page_queue: 903 * 904 * Return the index of the queue containing m. 905 */ 906 static inline uint8_t 907 vm_page_queue(vm_page_t m) 908 { 909 910 return (_vm_page_queue(vm_page_astate_load(m))); 911 } 912 913 static inline bool 914 vm_page_active(vm_page_t m) 915 { 916 917 return (vm_page_queue(m) == PQ_ACTIVE); 918 } 919 920 static inline bool 921 vm_page_inactive(vm_page_t m) 922 { 923 924 return (vm_page_queue(m) == PQ_INACTIVE); 925 } 926 927 static inline bool 928 vm_page_in_laundry(vm_page_t m) 929 { 930 uint8_t queue; 931 932 queue = vm_page_queue(m); 933 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE); 934 } 935 936 /* 937 * vm_page_drop: 938 * 939 * Release a reference to a page and return the old reference count. 940 */ 941 static inline u_int 942 vm_page_drop(vm_page_t m, u_int val) 943 { 944 u_int old; 945 946 /* 947 * Synchronize with vm_page_free_prep(): ensure that all updates to the 948 * page structure are visible before it is freed. 949 */ 950 atomic_thread_fence_rel(); 951 old = atomic_fetchadd_int(&m->ref_count, -val); 952 KASSERT(old != VPRC_BLOCKED, 953 ("vm_page_drop: page %p has an invalid refcount value", m)); 954 return (old); 955 } 956 957 /* 958 * vm_page_wired: 959 * 960 * Perform a racy check to determine whether a reference prevents the page 961 * from being reclaimable. If the page's object is locked, and the page is 962 * unmapped and exclusively busied by the current thread, no new wirings 963 * may be created. 964 */ 965 static inline bool 966 vm_page_wired(vm_page_t m) 967 { 968 969 return (VPRC_WIRE_COUNT(m->ref_count) > 0); 970 } 971 972 static inline bool 973 vm_page_all_valid(vm_page_t m) 974 { 975 976 return (m->valid == VM_PAGE_BITS_ALL); 977 } 978 979 static inline bool 980 vm_page_none_valid(vm_page_t m) 981 { 982 983 return (m->valid == 0); 984 } 985 986 #endif /* _KERNEL */ 987 #endif /* !_VM_PAGE_ */ 988