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 field is the index of the page queue containing the page, 175 * or PQ_NONE if the page is not enqueued. The queue lock of a page is 176 * the page queue lock corresponding to the page queue index, or the 177 * page lock (P) for the page if it is not enqueued. To modify the 178 * queue field, the queue lock for the old value of the field must be 179 * held. There is one exception to this rule: the page daemon may 180 * transition the queue field from PQ_INACTIVE to PQ_NONE immediately 181 * prior to freeing a page during an inactive queue scan. At that 182 * point the page has already been physically dequeued and no other 183 * references to that vm_page structure exist. 184 * 185 * To avoid contention on page queue locks, page queue operations 186 * (enqueue, dequeue, requeue) are batched using per-CPU queues. A 187 * deferred operation is requested by inserting an entry into a batch 188 * queue; the entry is simply a pointer to the page, and the request 189 * type is encoded in the page's aflags field using the values in 190 * PGA_QUEUE_STATE_MASK. The type-stability of struct vm_pages is 191 * crucial to this scheme since the processing of entries in a given 192 * batch queue may be deferred indefinitely. In particular, a page may 193 * be freed before its pending batch queue entries have been processed. 194 * The page lock (P) must be held to schedule a batched queue 195 * operation, and the page queue lock must be held in order to process 196 * batch queue entries for the page queue. There is one exception to 197 * this rule: the thread freeing a page may schedule a dequeue without 198 * holding the page lock. In this scenario the only other thread which 199 * may hold a reference to the page is the page daemon, which is 200 * careful to avoid modifying the page's queue state once the dequeue 201 * has been requested by setting PGA_DEQUEUE. 202 */ 203 204 #if PAGE_SIZE == 4096 205 #define VM_PAGE_BITS_ALL 0xffu 206 typedef uint8_t vm_page_bits_t; 207 #elif PAGE_SIZE == 8192 208 #define VM_PAGE_BITS_ALL 0xffffu 209 typedef uint16_t vm_page_bits_t; 210 #elif PAGE_SIZE == 16384 211 #define VM_PAGE_BITS_ALL 0xffffffffu 212 typedef uint32_t vm_page_bits_t; 213 #elif PAGE_SIZE == 32768 214 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 215 typedef uint64_t vm_page_bits_t; 216 #endif 217 218 typedef union vm_page_astate { 219 struct { 220 uint16_t flags; 221 uint8_t queue; 222 uint8_t act_count; 223 }; 224 uint32_t _bits; 225 } vm_page_astate_t; 226 227 struct vm_page { 228 union { 229 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */ 230 struct { 231 SLIST_ENTRY(vm_page) ss; /* private slists */ 232 } s; 233 struct { 234 u_long p; 235 u_long v; 236 } memguard; 237 struct { 238 void *slab; 239 void *zone; 240 } uma; 241 } plinks; 242 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 243 vm_object_t object; /* which object am I in (O) */ 244 vm_pindex_t pindex; /* offset into object (O,P) */ 245 vm_paddr_t phys_addr; /* physical address of page (C) */ 246 struct md_page md; /* machine dependent stuff */ 247 u_int ref_count; /* page references (A) */ 248 volatile u_int busy_lock; /* busy owners lock */ 249 union vm_page_astate a; /* state accessed atomically */ 250 uint8_t order; /* index of the buddy queue (F) */ 251 uint8_t pool; /* vm_phys freepool index (F) */ 252 uint8_t flags; /* page PG_* flags (P) */ 253 uint8_t oflags; /* page VPO_* flags (O) */ 254 int8_t psind; /* pagesizes[] index (O) */ 255 int8_t segind; /* vm_phys segment index (C) */ 256 /* NOTE that these must support one bit per DEV_BSIZE in a page */ 257 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 258 vm_page_bits_t valid; /* valid DEV_BSIZE chunk map (O,B) */ 259 vm_page_bits_t dirty; /* dirty DEV_BSIZE chunk map (M,B) */ 260 }; 261 262 /* 263 * Special bits used in the ref_count field. 264 * 265 * ref_count is normally used to count wirings that prevent the page from being 266 * reclaimed, but also supports several special types of references that do not 267 * prevent reclamation. Accesses to the ref_count field must be atomic unless 268 * the page is unallocated. 269 * 270 * VPRC_OBJREF is the reference held by the containing object. It can set or 271 * cleared only when the corresponding object's write lock is held. 272 * 273 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while 274 * attempting to tear down all mappings of a given page. The page lock and 275 * object write lock must both be held in order to set or clear this bit. 276 */ 277 #define VPRC_BLOCKED 0x40000000u /* mappings are being removed */ 278 #define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */ 279 #define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF)) 280 #define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF)) 281 282 /* 283 * Page flags stored in oflags: 284 * 285 * Access to these page flags is synchronized by the lock on the object 286 * containing the page (O). 287 * 288 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG) 289 * indicates that the page is not under PV management but 290 * otherwise should be treated as a normal page. Pages not 291 * under PV management cannot be paged out via the 292 * object/vm_page_t because there is no knowledge of their pte 293 * mappings, and such pages are also not on any PQ queue. 294 * 295 */ 296 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */ 297 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */ 298 #define VPO_UNMANAGED 0x04 /* no PV management for page */ 299 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */ 300 301 /* 302 * Busy page implementation details. 303 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation, 304 * even if the support for owner identity is removed because of size 305 * constraints. Checks on lock recursion are then not possible, while the 306 * lock assertions effectiveness is someway reduced. 307 */ 308 #define VPB_BIT_SHARED 0x01 309 #define VPB_BIT_EXCLUSIVE 0x02 310 #define VPB_BIT_WAITERS 0x04 311 #define VPB_BIT_FLAGMASK \ 312 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS) 313 314 #define VPB_SHARERS_SHIFT 3 315 #define VPB_SHARERS(x) \ 316 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT) 317 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED) 318 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT) 319 320 #define VPB_SINGLE_EXCLUSIVE VPB_BIT_EXCLUSIVE 321 #ifdef INVARIANTS 322 #define VPB_CURTHREAD_EXCLUSIVE \ 323 (VPB_BIT_EXCLUSIVE | ((u_int)(uintptr_t)curthread & ~VPB_BIT_FLAGMASK)) 324 #else 325 #define VPB_CURTHREAD_EXCLUSIVE VPB_SINGLE_EXCLUSIVE 326 #endif 327 328 #define VPB_UNBUSIED VPB_SHARERS_WORD(0) 329 330 #define PQ_NONE 255 331 #define PQ_INACTIVE 0 332 #define PQ_ACTIVE 1 333 #define PQ_LAUNDRY 2 334 #define PQ_UNSWAPPABLE 3 335 #define PQ_COUNT 4 336 337 #ifndef VM_PAGE_HAVE_PGLIST 338 TAILQ_HEAD(pglist, vm_page); 339 #define VM_PAGE_HAVE_PGLIST 340 #endif 341 SLIST_HEAD(spglist, vm_page); 342 343 #ifdef _KERNEL 344 extern vm_page_t bogus_page; 345 #endif /* _KERNEL */ 346 347 extern struct mtx_padalign pa_lock[]; 348 349 #if defined(__arm__) 350 #define PDRSHIFT PDR_SHIFT 351 #elif !defined(PDRSHIFT) 352 #define PDRSHIFT 21 353 #endif 354 355 #define pa_index(pa) ((pa) >> PDRSHIFT) 356 #define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT])) 357 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa))) 358 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa)) 359 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa)) 360 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa)) 361 #define PA_UNLOCK_COND(pa) \ 362 do { \ 363 if ((pa) != 0) { \ 364 PA_UNLOCK((pa)); \ 365 (pa) = 0; \ 366 } \ 367 } while (0) 368 369 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a)) 370 371 #if defined(KLD_MODULE) && !defined(KLD_TIED) 372 #define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE) 373 #define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE) 374 #define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE) 375 #else /* !KLD_MODULE */ 376 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m)))) 377 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m))) 378 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m))) 379 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m))) 380 #endif 381 #if defined(INVARIANTS) 382 #define vm_page_assert_locked(m) \ 383 vm_page_assert_locked_KBI((m), __FILE__, __LINE__) 384 #define vm_page_lock_assert(m, a) \ 385 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__) 386 #else 387 #define vm_page_assert_locked(m) 388 #define vm_page_lock_assert(m, a) 389 #endif 390 391 /* 392 * The vm_page's aflags are updated using atomic operations. To set or clear 393 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear() 394 * must be used. Neither these flags nor these functions are part of the KBI. 395 * 396 * PGA_REFERENCED may be cleared only if the page is locked. It is set by 397 * both the MI and MD VM layers. However, kernel loadable modules should not 398 * directly set this flag. They should call vm_page_reference() instead. 399 * 400 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). 401 * When it does so, the object must be locked, or the page must be 402 * exclusive busied. The MI VM layer must never access this flag 403 * directly. Instead, it should call pmap_page_is_write_mapped(). 404 * 405 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has 406 * at least one executable mapping. It is not consumed by the MI VM layer. 407 * 408 * PGA_NOSYNC must be set and cleared with the page busy lock held. 409 * 410 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed 411 * from a page queue, respectively. It determines whether the plinks.q field 412 * of the page is valid. To set or clear this flag, the queue lock for the 413 * page must be held: the page queue lock corresponding to the page's "queue" 414 * field if its value is not PQ_NONE, and the page lock otherwise. 415 * 416 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page 417 * queue, and cleared when the dequeue request is processed. A page may 418 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue 419 * is requested after the page is scheduled to be enqueued but before it is 420 * actually inserted into the page queue. For allocated pages, the page lock 421 * must be held to set this flag, but it may be set by vm_page_free_prep() 422 * without the page lock held. The page queue lock must be held to clear the 423 * PGA_DEQUEUE flag. 424 * 425 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued 426 * in its page queue. The page lock must be held to set this flag, and the 427 * queue lock for the page must be held to clear it. 428 * 429 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of 430 * the inactive queue, thus bypassing LRU. The page lock must be held to 431 * set this flag, and the queue lock for the page must be held to clear it. 432 * 433 * PGA_SWAP_FREE is used to defer freeing swap space to the pageout daemon 434 * when the context that dirties the page does not have the object write lock 435 * held. 436 */ 437 #define PGA_WRITEABLE 0x0001 /* page may be mapped writeable */ 438 #define PGA_REFERENCED 0x0002 /* page has been referenced */ 439 #define PGA_EXECUTABLE 0x0004 /* page may be mapped executable */ 440 #define PGA_ENQUEUED 0x0008 /* page is enqueued in a page queue */ 441 #define PGA_DEQUEUE 0x0010 /* page is due to be dequeued */ 442 #define PGA_REQUEUE 0x0020 /* page is due to be requeued */ 443 #define PGA_REQUEUE_HEAD 0x0040 /* page requeue should bypass LRU */ 444 #define PGA_NOSYNC 0x0080 /* do not collect for syncer */ 445 #define PGA_SWAP_FREE 0x0100 /* page with swap space was dirtied */ 446 #define PGA_SWAP_SPACE 0x0200 /* page has allocated swap space */ 447 448 #define PGA_QUEUE_OP_MASK (PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD) 449 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_QUEUE_OP_MASK) 450 451 /* 452 * Page flags. If changed at any other time than page allocation or 453 * freeing, the modification must be protected by the vm_page lock. 454 * 455 * The PG_PCPU_CACHE flag is set at allocation time if the page was 456 * allocated from a per-CPU cache. It is cleared the next time that the 457 * page is allocated from the physical memory allocator. 458 */ 459 #define PG_PCPU_CACHE 0x01 /* was allocated from per-CPU caches */ 460 #define PG_FICTITIOUS 0x02 /* physical page doesn't exist */ 461 #define PG_ZERO 0x04 /* page is zeroed */ 462 #define PG_MARKER 0x08 /* special queue marker page */ 463 #define PG_NODUMP 0x10 /* don't include this page in a dump */ 464 465 /* 466 * Misc constants. 467 */ 468 #define ACT_DECLINE 1 469 #define ACT_ADVANCE 3 470 #define ACT_INIT 5 471 #define ACT_MAX 64 472 473 #ifdef _KERNEL 474 475 #include <sys/systm.h> 476 477 #include <machine/atomic.h> 478 479 /* 480 * Each pageable resident page falls into one of five lists: 481 * 482 * free 483 * Available for allocation now. 484 * 485 * inactive 486 * Low activity, candidates for reclamation. 487 * This list is approximately LRU ordered. 488 * 489 * laundry 490 * This is the list of pages that should be 491 * paged out next. 492 * 493 * unswappable 494 * Dirty anonymous pages that cannot be paged 495 * out because no swap device is configured. 496 * 497 * active 498 * Pages that are "active", i.e., they have been 499 * recently referenced. 500 * 501 */ 502 503 extern vm_page_t vm_page_array; /* First resident page in table */ 504 extern long vm_page_array_size; /* number of vm_page_t's */ 505 extern long first_page; /* first physical page number */ 506 507 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 508 509 /* 510 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory 511 * page to which the given physical address belongs. The correct vm_page_t 512 * object is returned for addresses that are not page-aligned. 513 */ 514 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 515 516 /* 517 * Page allocation parameters for vm_page for the functions 518 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and 519 * vm_page_alloc_freelist(). Some functions support only a subset 520 * of the flags, and ignore others, see the flags legend. 521 * 522 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*() 523 * and the vm_page_grab*() functions. See these functions for details. 524 * 525 * Bits 0 - 1 define class. 526 * Bits 2 - 15 dedicated for flags. 527 * Legend: 528 * (a) - vm_page_alloc() supports the flag. 529 * (c) - vm_page_alloc_contig() supports the flag. 530 * (f) - vm_page_alloc_freelist() supports the flag. 531 * (g) - vm_page_grab() supports the flag. 532 * (p) - vm_page_grab_pages() supports the flag. 533 * Bits above 15 define the count of additional pages that the caller 534 * intends to allocate. 535 */ 536 #define VM_ALLOC_NORMAL 0 537 #define VM_ALLOC_INTERRUPT 1 538 #define VM_ALLOC_SYSTEM 2 539 #define VM_ALLOC_CLASS_MASK 3 540 #define VM_ALLOC_WAITOK 0x0008 /* (acf) Sleep and retry */ 541 #define VM_ALLOC_WAITFAIL 0x0010 /* (acf) Sleep and return error */ 542 #define VM_ALLOC_WIRED 0x0020 /* (acfgp) Allocate a wired page */ 543 #define VM_ALLOC_ZERO 0x0040 /* (acfgp) Allocate a prezeroed page */ 544 #define VM_ALLOC_NOOBJ 0x0100 /* (acg) No associated object */ 545 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */ 546 #define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */ 547 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */ 548 #define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */ 549 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */ 550 #define VM_ALLOC_NOWAIT 0x8000 /* (acfgp) Do not sleep */ 551 #define VM_ALLOC_COUNT_SHIFT 16 552 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) 553 554 #ifdef M_NOWAIT 555 static inline int 556 malloc2vm_flags(int malloc_flags) 557 { 558 int pflags; 559 560 KASSERT((malloc_flags & M_USE_RESERVE) == 0 || 561 (malloc_flags & M_NOWAIT) != 0, 562 ("M_USE_RESERVE requires M_NOWAIT")); 563 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT : 564 VM_ALLOC_SYSTEM; 565 if ((malloc_flags & M_ZERO) != 0) 566 pflags |= VM_ALLOC_ZERO; 567 if ((malloc_flags & M_NODUMP) != 0) 568 pflags |= VM_ALLOC_NODUMP; 569 if ((malloc_flags & M_NOWAIT)) 570 pflags |= VM_ALLOC_NOWAIT; 571 if ((malloc_flags & M_WAITOK)) 572 pflags |= VM_ALLOC_WAITOK; 573 return (pflags); 574 } 575 #endif 576 577 /* 578 * Predicates supported by vm_page_ps_test(): 579 * 580 * PS_ALL_DIRTY is true only if the entire (super)page is dirty. 581 * However, it can be spuriously false when the (super)page has become 582 * dirty in the pmap but that information has not been propagated to the 583 * machine-independent layer. 584 */ 585 #define PS_ALL_DIRTY 0x1 586 #define PS_ALL_VALID 0x2 587 #define PS_NONE_BUSY 0x4 588 589 bool vm_page_busy_acquire(vm_page_t m, int allocflags); 590 void vm_page_busy_downgrade(vm_page_t m); 591 int vm_page_busy_tryupgrade(vm_page_t m); 592 void vm_page_busy_sleep(vm_page_t m, const char *msg, bool nonshared); 593 void vm_page_free(vm_page_t m); 594 void vm_page_free_zero(vm_page_t m); 595 596 void vm_page_activate (vm_page_t); 597 void vm_page_advise(vm_page_t m, int advice); 598 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int); 599 vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int); 600 vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t); 601 vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int, 602 vm_page_t); 603 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 604 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 605 vm_paddr_t boundary, vm_memattr_t memattr); 606 vm_page_t vm_page_alloc_contig_domain(vm_object_t object, 607 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low, 608 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 609 vm_memattr_t memattr); 610 vm_page_t vm_page_alloc_freelist(int, int); 611 vm_page_t vm_page_alloc_freelist_domain(int, int, int); 612 void vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set); 613 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose); 614 void vm_page_change_lock(vm_page_t m, struct mtx **mtx); 615 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int); 616 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 617 vm_page_t *ma, int count); 618 int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 619 int allocflags); 620 void vm_page_deactivate(vm_page_t); 621 void vm_page_deactivate_noreuse(vm_page_t); 622 void vm_page_dequeue(vm_page_t m); 623 void vm_page_dequeue_deferred(vm_page_t m); 624 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t); 625 bool vm_page_free_prep(vm_page_t m); 626 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 627 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 628 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 629 void vm_page_invalid(vm_page_t m); 630 void vm_page_launder(vm_page_t m); 631 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t); 632 vm_page_t vm_page_next(vm_page_t m); 633 void vm_page_pqbatch_drain(void); 634 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue); 635 vm_page_t vm_page_prev(vm_page_t m); 636 bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m); 637 void vm_page_putfake(vm_page_t m); 638 void vm_page_readahead_finish(vm_page_t m); 639 bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, 640 vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 641 bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 642 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 643 void vm_page_reference(vm_page_t m); 644 #define VPR_TRYFREE 0x01 645 #define VPR_NOREUSE 0x02 646 void vm_page_release(vm_page_t m, int flags); 647 void vm_page_release_locked(vm_page_t m, int flags); 648 bool vm_page_remove(vm_page_t); 649 int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t); 650 vm_page_t vm_page_replace(vm_page_t mnew, vm_object_t object, 651 vm_pindex_t pindex); 652 void vm_page_requeue(vm_page_t m); 653 int vm_page_sbusied(vm_page_t m); 654 vm_page_t vm_page_scan_contig(u_long npages, vm_page_t m_start, 655 vm_page_t m_end, u_long alignment, vm_paddr_t boundary, int options); 656 vm_page_bits_t vm_page_set_dirty(vm_page_t m); 657 void vm_page_set_valid_range(vm_page_t m, int base, int size); 658 int vm_page_sleep_if_busy(vm_page_t m, const char *msg); 659 int vm_page_sleep_if_xbusy(vm_page_t m, const char *msg); 660 vm_offset_t vm_page_startup(vm_offset_t vaddr); 661 void vm_page_sunbusy(vm_page_t m); 662 void vm_page_swapqueue(vm_page_t m, uint8_t oldq, uint8_t newq); 663 bool vm_page_try_remove_all(vm_page_t m); 664 bool vm_page_try_remove_write(vm_page_t m); 665 int vm_page_trysbusy(vm_page_t m); 666 int vm_page_tryxbusy(vm_page_t m); 667 void vm_page_unhold_pages(vm_page_t *ma, int count); 668 void vm_page_unswappable(vm_page_t m); 669 void vm_page_unwire(vm_page_t m, uint8_t queue); 670 bool vm_page_unwire_noq(vm_page_t m); 671 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 672 void vm_page_wire(vm_page_t); 673 bool vm_page_wire_mapped(vm_page_t m); 674 void vm_page_xunbusy_hard(vm_page_t m); 675 void vm_page_xunbusy_hard_unchecked(vm_page_t m); 676 void vm_page_set_validclean (vm_page_t, int, int); 677 void vm_page_clear_dirty(vm_page_t, int, int); 678 void vm_page_set_invalid(vm_page_t, int, int); 679 void vm_page_valid(vm_page_t m); 680 int vm_page_is_valid(vm_page_t, int, int); 681 void vm_page_test_dirty(vm_page_t); 682 vm_page_bits_t vm_page_bits(int base, int size); 683 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 684 void vm_page_free_toq(vm_page_t m); 685 void vm_page_free_pages_toq(struct spglist *free, bool update_wire_count); 686 687 void vm_page_dirty_KBI(vm_page_t m); 688 void vm_page_lock_KBI(vm_page_t m, const char *file, int line); 689 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line); 690 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line); 691 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 692 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line); 693 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line); 694 #endif 695 696 #define vm_page_assert_busied(m) \ 697 KASSERT(vm_page_busied(m), \ 698 ("vm_page_assert_busied: page %p not busy @ %s:%d", \ 699 (m), __FILE__, __LINE__)) 700 701 #define vm_page_assert_sbusied(m) \ 702 KASSERT(vm_page_sbusied(m), \ 703 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \ 704 (m), __FILE__, __LINE__)) 705 706 #define vm_page_assert_unbusied(m) \ 707 KASSERT(!vm_page_busied(m), \ 708 ("vm_page_assert_unbusied: page %p busy @ %s:%d", \ 709 (m), __FILE__, __LINE__)) 710 711 #define vm_page_assert_xbusied_unchecked(m) do { \ 712 KASSERT(vm_page_xbusied(m), \ 713 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \ 714 (m), __FILE__, __LINE__)); \ 715 } while (0) 716 #define vm_page_assert_xbusied(m) do { \ 717 vm_page_assert_xbusied_unchecked(m); \ 718 KASSERT((m->busy_lock & ~VPB_BIT_WAITERS) == \ 719 VPB_CURTHREAD_EXCLUSIVE, \ 720 ("vm_page_assert_xbusied: page %p busy_lock %#x not owned" \ 721 " by me @ %s:%d", \ 722 (m), (m)->busy_lock, __FILE__, __LINE__)); \ 723 } while (0) 724 725 #define vm_page_busied(m) \ 726 ((m)->busy_lock != VPB_UNBUSIED) 727 728 #define vm_page_sbusy(m) do { \ 729 if (!vm_page_trysbusy(m)) \ 730 panic("%s: page %p failed shared busying", __func__, \ 731 (m)); \ 732 } while (0) 733 734 #define vm_page_xbusied(m) \ 735 (((m)->busy_lock & VPB_SINGLE_EXCLUSIVE) != 0) 736 737 #define vm_page_xbusy(m) do { \ 738 if (!vm_page_tryxbusy(m)) \ 739 panic("%s: page %p failed exclusive busying", __func__, \ 740 (m)); \ 741 } while (0) 742 743 /* Note: page m's lock must not be owned by the caller. */ 744 #define vm_page_xunbusy(m) do { \ 745 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 746 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 747 vm_page_xunbusy_hard(m); \ 748 } while (0) 749 #define vm_page_xunbusy_unchecked(m) do { \ 750 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 751 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 752 vm_page_xunbusy_hard_unchecked(m); \ 753 } while (0) 754 755 #ifdef INVARIANTS 756 void vm_page_object_busy_assert(vm_page_t m); 757 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) vm_page_object_busy_assert(m) 758 void vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits); 759 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \ 760 vm_page_assert_pga_writeable(m, bits) 761 #else 762 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) (void)0 763 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0 764 #endif 765 766 #if BYTE_ORDER == BIG_ENDIAN 767 #define VM_PAGE_AFLAG_SHIFT 16 768 #else 769 #define VM_PAGE_AFLAG_SHIFT 0 770 #endif 771 772 /* 773 * Load a snapshot of a page's 32-bit atomic state. 774 */ 775 static inline vm_page_astate_t 776 vm_page_astate_load(vm_page_t m) 777 { 778 vm_page_astate_t a; 779 780 a._bits = atomic_load_32(&m->a._bits); 781 return (a); 782 } 783 784 /* 785 * Atomically compare and set a page's atomic state. 786 */ 787 static inline bool 788 vm_page_astate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 789 { 790 791 KASSERT(new.queue == PQ_INACTIVE || (new.flags & PGA_REQUEUE_HEAD) == 0, 792 ("%s: invalid head requeue request for page %p", __func__, m)); 793 KASSERT((new.flags & PGA_ENQUEUED) == 0 || new.queue != PQ_NONE, 794 ("%s: setting PGA_ENQUEUED with PQ_NONE in page %p", __func__, m)); 795 KASSERT(new._bits != old->_bits, 796 ("%s: bits are unchanged", __func__)); 797 798 return (atomic_fcmpset_32(&m->a._bits, &old->_bits, new._bits) != 0); 799 } 800 801 /* 802 * Clear the given bits in the specified page. 803 */ 804 static inline void 805 vm_page_aflag_clear(vm_page_t m, uint16_t bits) 806 { 807 uint32_t *addr, val; 808 809 /* 810 * The PGA_REFERENCED flag can only be cleared if the page is locked. 811 */ 812 if ((bits & PGA_REFERENCED) != 0) 813 vm_page_assert_locked(m); 814 815 /* 816 * Access the whole 32-bit word containing the aflags field with an 817 * atomic update. Parallel non-atomic updates to the other fields 818 * within this word are handled properly by the atomic update. 819 */ 820 addr = (void *)&m->a; 821 val = bits << VM_PAGE_AFLAG_SHIFT; 822 atomic_clear_32(addr, val); 823 } 824 825 /* 826 * Set the given bits in the specified page. 827 */ 828 static inline void 829 vm_page_aflag_set(vm_page_t m, uint16_t bits) 830 { 831 uint32_t *addr, val; 832 833 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits); 834 835 /* 836 * Access the whole 32-bit word containing the aflags field with an 837 * atomic update. Parallel non-atomic updates to the other fields 838 * within this word are handled properly by the atomic update. 839 */ 840 addr = (void *)&m->a; 841 val = bits << VM_PAGE_AFLAG_SHIFT; 842 atomic_set_32(addr, val); 843 } 844 845 /* 846 * Atomically update the queue state of the page. The operation fails if 847 * any of the queue flags in "fflags" are set or if the "queue" field of 848 * the page does not match the expected value; if the operation is 849 * successful, the flags in "nflags" are set and all other queue state 850 * flags are cleared. 851 */ 852 static inline bool 853 vm_page_pqstate_cmpset(vm_page_t m, uint32_t oldq, uint32_t newq, 854 uint32_t fflags, uint32_t nflags) 855 { 856 vm_page_astate_t new, old; 857 858 old = vm_page_astate_load(m); 859 do { 860 if ((old.flags & fflags) != 0 || old.queue != oldq) 861 return (false); 862 new = old; 863 new.flags = (new.flags & ~PGA_QUEUE_OP_MASK) | nflags; 864 new.queue = newq; 865 } while (!vm_page_astate_fcmpset(m, &old, new)); 866 867 return (true); 868 } 869 870 /* 871 * vm_page_dirty: 872 * 873 * Set all bits in the page's dirty field. 874 * 875 * The object containing the specified page must be locked if the 876 * call is made from the machine-independent layer. 877 * 878 * See vm_page_clear_dirty_mask(). 879 */ 880 static __inline void 881 vm_page_dirty(vm_page_t m) 882 { 883 884 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */ 885 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS) 886 vm_page_dirty_KBI(m); 887 #else 888 m->dirty = VM_PAGE_BITS_ALL; 889 #endif 890 } 891 892 /* 893 * vm_page_undirty: 894 * 895 * Set page to not be dirty. Note: does not clear pmap modify bits 896 */ 897 static __inline void 898 vm_page_undirty(vm_page_t m) 899 { 900 901 VM_PAGE_OBJECT_BUSY_ASSERT(m); 902 m->dirty = 0; 903 } 904 905 static inline void 906 vm_page_replace_checked(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 907 vm_page_t mold) 908 { 909 vm_page_t mret; 910 911 mret = vm_page_replace(mnew, object, pindex); 912 KASSERT(mret == mold, 913 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 914 915 /* Unused if !INVARIANTS. */ 916 (void)mold; 917 (void)mret; 918 } 919 920 /* 921 * vm_page_queue: 922 * 923 * Return the index of the queue containing m. This index is guaranteed 924 * not to change while the page lock is held. 925 */ 926 static inline uint8_t 927 vm_page_queue(vm_page_t m) 928 { 929 930 vm_page_assert_locked(m); 931 932 if ((m->a.flags & PGA_DEQUEUE) != 0) 933 return (PQ_NONE); 934 atomic_thread_fence_acq(); 935 return (m->a.queue); 936 } 937 938 static inline bool 939 vm_page_active(vm_page_t m) 940 { 941 942 return (vm_page_queue(m) == PQ_ACTIVE); 943 } 944 945 static inline bool 946 vm_page_inactive(vm_page_t m) 947 { 948 949 return (vm_page_queue(m) == PQ_INACTIVE); 950 } 951 952 static inline bool 953 vm_page_in_laundry(vm_page_t m) 954 { 955 uint8_t queue; 956 957 queue = vm_page_queue(m); 958 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE); 959 } 960 961 /* 962 * vm_page_drop: 963 * 964 * Release a reference to a page and return the old reference count. 965 */ 966 static inline u_int 967 vm_page_drop(vm_page_t m, u_int val) 968 { 969 u_int old; 970 971 /* 972 * Synchronize with vm_page_free_prep(): ensure that all updates to the 973 * page structure are visible before it is freed. 974 */ 975 atomic_thread_fence_rel(); 976 old = atomic_fetchadd_int(&m->ref_count, -val); 977 KASSERT(old != VPRC_BLOCKED, 978 ("vm_page_drop: page %p has an invalid refcount value", m)); 979 return (old); 980 } 981 982 /* 983 * vm_page_wired: 984 * 985 * Perform a racy check to determine whether a reference prevents the page 986 * from being reclaimable. If the page's object is locked, and the page is 987 * unmapped and unbusied or exclusively busied by the current thread, no 988 * new wirings may be created. 989 */ 990 static inline bool 991 vm_page_wired(vm_page_t m) 992 { 993 994 return (VPRC_WIRE_COUNT(m->ref_count) > 0); 995 } 996 997 static inline bool 998 vm_page_all_valid(vm_page_t m) 999 { 1000 1001 return (m->valid == VM_PAGE_BITS_ALL); 1002 } 1003 1004 static inline bool 1005 vm_page_none_valid(vm_page_t m) 1006 { 1007 1008 return (m->valid == 0); 1009 } 1010 1011 #endif /* _KERNEL */ 1012 #endif /* !_VM_PAGE_ */ 1013