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 queue lock for a page depends on the value of its queue field and is 99 * described in detail below. 100 * 101 * The following annotations are possible: 102 * (A) the field must be accessed using atomic(9) and may require 103 * 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 * (Q) the page's queue lock. 110 * 111 * The busy lock is an embedded reader-writer lock that protects the 112 * page's contents and identity (i.e., its <object, pindex> tuple) as 113 * well as certain valid/dirty modifications. To avoid bloating the 114 * the page structure, the busy lock lacks some of the features available 115 * the kernel's general-purpose synchronization primitives. As a result, 116 * busy lock ordering rules are not verified, lock recursion is not 117 * detected, and an attempt to xbusy a busy page or sbusy an xbusy page 118 * results will trigger a panic rather than causing the thread to block. 119 * vm_page_sleep_if_busy() can be used to sleep until the page's busy 120 * state changes, after which the caller must re-lookup the page and 121 * re-evaluate its state. vm_page_busy_acquire() will block until 122 * the lock is acquired. 123 * 124 * The valid field is protected by the page busy lock (B) and object 125 * lock (O). Transitions from invalid to valid are generally done 126 * via I/O or zero filling and do not require the object lock. 127 * These must be protected with the busy lock to prevent page-in or 128 * creation races. Page invalidation generally happens as a result 129 * of truncate or msync. When invalidated, pages must not be present 130 * in pmap and must hold the object lock to prevent concurrent 131 * speculative read-only mappings that do not require busy. I/O 132 * routines may check for validity without a lock if they are prepared 133 * to handle invalidation races with higher level locks (vnode) or are 134 * unconcerned with races so long as they hold a reference to prevent 135 * recycling. When a valid bit is set while holding a shared busy 136 * lock (A) atomic operations are used to protect against concurrent 137 * modification. 138 * 139 * In contrast, the synchronization of accesses to the page's 140 * dirty field is a mix of machine dependent (M) and busy (B). In 141 * the machine-independent layer, the page busy must be held to 142 * operate on the field. However, the pmap layer is permitted to 143 * set all bits within the field without holding that lock. If the 144 * underlying architecture does not support atomic read-modify-write 145 * operations on the field's type, then the machine-independent 146 * layer uses a 32-bit atomic on the aligned 32-bit word that 147 * contains the dirty field. In the machine-independent layer, 148 * the implementation of read-modify-write operations on the 149 * field is encapsulated in vm_page_clear_dirty_mask(). An 150 * exclusive busy lock combined with pmap_remove_{write/all}() is the 151 * only way to ensure a page can not become dirty. I/O generally 152 * removes the page from pmap to ensure exclusive access and atomic 153 * writes. 154 * 155 * The ref_count field tracks references to the page. References that 156 * prevent the page from being reclaimable are called wirings and are 157 * counted in the low bits of ref_count. The containing object's 158 * reference, if one exists, is counted using the VPRC_OBJREF bit in the 159 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to 160 * atomically check for wirings and prevent new wirings via 161 * pmap_extract_and_hold(). When a page belongs to an object, it may be 162 * wired only when the object is locked, or the page is busy, or by 163 * pmap_extract_and_hold(). As a result, if the object is locked and the 164 * page is not busy (or is exclusively busied by the current thread), and 165 * the page is unmapped, its wire count will not increase. The ref_count 166 * field is updated using atomic operations in most cases, except when it 167 * is known that no other references to the page exist, such as in the page 168 * allocator. A page may be present in the page queues, or even actively 169 * scanned by the page daemon, without an explicitly counted referenced. 170 * The page daemon must therefore handle the possibility of a concurrent 171 * free of the page. 172 * 173 * The queue state of a page consists of the queue and act_count fields of 174 * its atomically updated state, and the subset of atomic flags specified 175 * by PGA_QUEUE_STATE_MASK. The queue field contains the page's page queue 176 * index, or PQ_NONE if it does not belong to a page queue. To modify the 177 * queue field, the page queue lock corresponding to the old value must be 178 * held, unless that value is PQ_NONE, in which case the queue index must 179 * be updated using an atomic RMW operation. There is one exception to 180 * this rule: the page daemon may transition the queue field from 181 * PQ_INACTIVE to PQ_NONE immediately prior to freeing the page during an 182 * inactive queue scan. At that point the page is already dequeued and no 183 * other references to that vm_page structure can exist. The PGA_ENQUEUED 184 * flag, when set, indicates that the page structure is physically inserted 185 * into the queue corresponding to the page's queue index, and may only be 186 * set or cleared with the corresponding page queue lock held. 187 * 188 * To avoid contention on page queue locks, page queue operations (enqueue, 189 * dequeue, requeue) are batched using fixed-size per-CPU queues. A 190 * deferred operation is requested by setting one of the flags in 191 * PGA_QUEUE_OP_MASK and inserting an entry into a batch queue. When a 192 * queue is full, an attempt to insert a new entry will lock the page 193 * queues and trigger processing of the pending entries. The 194 * type-stability of vm_page structures is crucial to this scheme since the 195 * processing of entries in a given batch queue may be deferred 196 * indefinitely. In particular, a page may be freed with pending batch 197 * queue entries. The page queue operation flags must be set using atomic 198 * RWM operations. 199 */ 200 201 #if PAGE_SIZE == 4096 202 #define VM_PAGE_BITS_ALL 0xffu 203 typedef uint8_t vm_page_bits_t; 204 #elif PAGE_SIZE == 8192 205 #define VM_PAGE_BITS_ALL 0xffffu 206 typedef uint16_t vm_page_bits_t; 207 #elif PAGE_SIZE == 16384 208 #define VM_PAGE_BITS_ALL 0xffffffffu 209 typedef uint32_t vm_page_bits_t; 210 #elif PAGE_SIZE == 32768 211 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 212 typedef uint64_t vm_page_bits_t; 213 #endif 214 215 typedef union vm_page_astate { 216 struct { 217 uint16_t flags; 218 uint8_t queue; 219 uint8_t act_count; 220 }; 221 uint32_t _bits; 222 } vm_page_astate_t; 223 224 struct vm_page { 225 union { 226 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */ 227 struct { 228 SLIST_ENTRY(vm_page) ss; /* private slists */ 229 } s; 230 struct { 231 u_long p; 232 u_long v; 233 } memguard; 234 struct { 235 void *slab; 236 void *zone; 237 } uma; 238 } plinks; 239 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 240 vm_object_t object; /* which object am I in (O) */ 241 vm_pindex_t pindex; /* offset into object (O,P) */ 242 vm_paddr_t phys_addr; /* physical address of page (C) */ 243 struct md_page md; /* machine dependent stuff */ 244 u_int ref_count; /* page references (A) */ 245 u_int busy_lock; /* busy owners lock (A) */ 246 union vm_page_astate a; /* state accessed atomically (A) */ 247 uint8_t order; /* index of the buddy queue (F) */ 248 uint8_t pool; /* vm_phys freepool index (F) */ 249 uint8_t flags; /* page PG_* flags (P) */ 250 uint8_t oflags; /* page VPO_* flags (O) */ 251 int8_t psind; /* pagesizes[] index (O) */ 252 int8_t segind; /* vm_phys segment index (C) */ 253 /* NOTE that these must support one bit per DEV_BSIZE in a page */ 254 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 255 vm_page_bits_t valid; /* valid DEV_BSIZE chunk map (O,B) */ 256 vm_page_bits_t dirty; /* dirty DEV_BSIZE chunk map (M,B) */ 257 }; 258 259 /* 260 * Special bits used in the ref_count field. 261 * 262 * ref_count is normally used to count wirings that prevent the page from being 263 * reclaimed, but also supports several special types of references that do not 264 * prevent reclamation. Accesses to the ref_count field must be atomic unless 265 * the page is unallocated. 266 * 267 * VPRC_OBJREF is the reference held by the containing object. It can set or 268 * cleared only when the corresponding object's write lock is held. 269 * 270 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while 271 * attempting to tear down all mappings of a given page. The page busy lock and 272 * object write lock must both be held in order to set or clear this bit. 273 */ 274 #define VPRC_BLOCKED 0x40000000u /* mappings are being removed */ 275 #define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */ 276 #define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF)) 277 #define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF)) 278 279 /* 280 * Page flags stored in oflags: 281 * 282 * Access to these page flags is synchronized by the lock on the object 283 * containing the page (O). 284 * 285 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG) 286 * indicates that the page is not under PV management but 287 * otherwise should be treated as a normal page. Pages not 288 * under PV management cannot be paged out via the 289 * object/vm_page_t because there is no knowledge of their pte 290 * mappings, and such pages are also not on any PQ queue. 291 * 292 */ 293 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */ 294 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */ 295 #define VPO_UNMANAGED 0x04 /* no PV management for page */ 296 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */ 297 298 /* 299 * Busy page implementation details. 300 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation, 301 * even if the support for owner identity is removed because of size 302 * constraints. Checks on lock recursion are then not possible, while the 303 * lock assertions effectiveness is someway reduced. 304 */ 305 #define VPB_BIT_SHARED 0x01 306 #define VPB_BIT_EXCLUSIVE 0x02 307 #define VPB_BIT_WAITERS 0x04 308 #define VPB_BIT_FLAGMASK \ 309 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS) 310 311 #define VPB_SHARERS_SHIFT 3 312 #define VPB_SHARERS(x) \ 313 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT) 314 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED) 315 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT) 316 317 #define VPB_SINGLE_EXCLUSIVE VPB_BIT_EXCLUSIVE 318 #ifdef INVARIANTS 319 #define VPB_CURTHREAD_EXCLUSIVE \ 320 (VPB_BIT_EXCLUSIVE | ((u_int)(uintptr_t)curthread & ~VPB_BIT_FLAGMASK)) 321 #else 322 #define VPB_CURTHREAD_EXCLUSIVE VPB_SINGLE_EXCLUSIVE 323 #endif 324 325 #define VPB_UNBUSIED VPB_SHARERS_WORD(0) 326 327 /* Freed lock blocks both shared and exclusive. */ 328 #define VPB_FREED (0xffffffff - VPB_BIT_SHARED) 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, page's "queue" field must 413 * be a valid queue index, and the corresponding page queue lock must be held. 414 * 415 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page 416 * queue, and cleared when the dequeue request is processed. A page may 417 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue 418 * is requested after the page is scheduled to be enqueued but before it is 419 * actually inserted into the page queue. 420 * 421 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued 422 * in its page queue. 423 * 424 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of 425 * the inactive queue, thus bypassing LRU. 426 * 427 * The PGA_DEQUEUE, PGA_REQUEUE and PGA_REQUEUE_HEAD flags must be set using an 428 * atomic RMW operation to ensure that the "queue" field is a valid queue index, 429 * and the corresponding page queue lock must be held when clearing any of the 430 * flags. 431 * 432 * PGA_SWAP_FREE is used to defer freeing swap space to the pageout daemon 433 * when the context that dirties the page does not have the object write lock 434 * held. 435 */ 436 #define PGA_WRITEABLE 0x0001 /* page may be mapped writeable */ 437 #define PGA_REFERENCED 0x0002 /* page has been referenced */ 438 #define PGA_EXECUTABLE 0x0004 /* page may be mapped executable */ 439 #define PGA_ENQUEUED 0x0008 /* page is enqueued in a page queue */ 440 #define PGA_DEQUEUE 0x0010 /* page is due to be dequeued */ 441 #define PGA_REQUEUE 0x0020 /* page is due to be requeued */ 442 #define PGA_REQUEUE_HEAD 0x0040 /* page requeue should bypass LRU */ 443 #define PGA_NOSYNC 0x0080 /* do not collect for syncer */ 444 #define PGA_SWAP_FREE 0x0100 /* page with swap space was dirtied */ 445 #define PGA_SWAP_SPACE 0x0200 /* page has allocated swap space */ 446 447 #define PGA_QUEUE_OP_MASK (PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD) 448 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_QUEUE_OP_MASK) 449 450 /* 451 * Page flags. Updates to these flags are not synchronized, and thus they must 452 * be set during page allocation or free to avoid races. 453 * 454 * The PG_PCPU_CACHE flag is set at allocation time if the page was 455 * allocated from a per-CPU cache. It is cleared the next time that the 456 * page is allocated from the physical memory allocator. 457 */ 458 #define PG_PCPU_CACHE 0x01 /* was allocated from per-CPU caches */ 459 #define PG_FICTITIOUS 0x02 /* physical page doesn't exist */ 460 #define PG_ZERO 0x04 /* page is zeroed */ 461 #define PG_MARKER 0x08 /* special queue marker page */ 462 #define PG_NODUMP 0x10 /* don't include this page in a dump */ 463 464 /* 465 * Misc constants. 466 */ 467 #define ACT_DECLINE 1 468 #define ACT_ADVANCE 3 469 #define ACT_INIT 5 470 #define ACT_MAX 64 471 472 #ifdef _KERNEL 473 474 #include <sys/systm.h> 475 476 #include <machine/atomic.h> 477 478 /* 479 * Each pageable resident page falls into one of five lists: 480 * 481 * free 482 * Available for allocation now. 483 * 484 * inactive 485 * Low activity, candidates for reclamation. 486 * This list is approximately LRU ordered. 487 * 488 * laundry 489 * This is the list of pages that should be 490 * paged out next. 491 * 492 * unswappable 493 * Dirty anonymous pages that cannot be paged 494 * out because no swap device is configured. 495 * 496 * active 497 * Pages that are "active", i.e., they have been 498 * recently referenced. 499 * 500 */ 501 502 extern vm_page_t vm_page_array; /* First resident page in table */ 503 extern long vm_page_array_size; /* number of vm_page_t's */ 504 extern long first_page; /* first physical page number */ 505 506 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 507 508 /* 509 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory 510 * page to which the given physical address belongs. The correct vm_page_t 511 * object is returned for addresses that are not page-aligned. 512 */ 513 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 514 515 /* 516 * Page allocation parameters for vm_page for the functions 517 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and 518 * vm_page_alloc_freelist(). Some functions support only a subset 519 * of the flags, and ignore others, see the flags legend. 520 * 521 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*() 522 * and the vm_page_grab*() functions. See these functions for details. 523 * 524 * Bits 0 - 1 define class. 525 * Bits 2 - 15 dedicated for flags. 526 * Legend: 527 * (a) - vm_page_alloc() supports the flag. 528 * (c) - vm_page_alloc_contig() supports the flag. 529 * (f) - vm_page_alloc_freelist() supports the flag. 530 * (g) - vm_page_grab() supports the flag. 531 * (p) - vm_page_grab_pages() supports the flag. 532 * Bits above 15 define the count of additional pages that the caller 533 * intends to allocate. 534 */ 535 #define VM_ALLOC_NORMAL 0 536 #define VM_ALLOC_INTERRUPT 1 537 #define VM_ALLOC_SYSTEM 2 538 #define VM_ALLOC_CLASS_MASK 3 539 #define VM_ALLOC_WAITOK 0x0008 /* (acf) Sleep and retry */ 540 #define VM_ALLOC_WAITFAIL 0x0010 /* (acf) Sleep and return error */ 541 #define VM_ALLOC_WIRED 0x0020 /* (acfgp) Allocate a wired page */ 542 #define VM_ALLOC_ZERO 0x0040 /* (acfgp) Allocate a prezeroed page */ 543 #define VM_ALLOC_NOOBJ 0x0100 /* (acg) No associated object */ 544 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */ 545 #define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */ 546 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */ 547 #define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */ 548 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */ 549 #define VM_ALLOC_NOWAIT 0x8000 /* (acfgp) Do not sleep */ 550 #define VM_ALLOC_COUNT_SHIFT 16 551 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) 552 553 #ifdef M_NOWAIT 554 static inline int 555 malloc2vm_flags(int malloc_flags) 556 { 557 int pflags; 558 559 KASSERT((malloc_flags & M_USE_RESERVE) == 0 || 560 (malloc_flags & M_NOWAIT) != 0, 561 ("M_USE_RESERVE requires M_NOWAIT")); 562 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT : 563 VM_ALLOC_SYSTEM; 564 if ((malloc_flags & M_ZERO) != 0) 565 pflags |= VM_ALLOC_ZERO; 566 if ((malloc_flags & M_NODUMP) != 0) 567 pflags |= VM_ALLOC_NODUMP; 568 if ((malloc_flags & M_NOWAIT)) 569 pflags |= VM_ALLOC_NOWAIT; 570 if ((malloc_flags & M_WAITOK)) 571 pflags |= VM_ALLOC_WAITOK; 572 return (pflags); 573 } 574 #endif 575 576 /* 577 * Predicates supported by vm_page_ps_test(): 578 * 579 * PS_ALL_DIRTY is true only if the entire (super)page is dirty. 580 * However, it can be spuriously false when the (super)page has become 581 * dirty in the pmap but that information has not been propagated to the 582 * machine-independent layer. 583 */ 584 #define PS_ALL_DIRTY 0x1 585 #define PS_ALL_VALID 0x2 586 #define PS_NONE_BUSY 0x4 587 588 bool vm_page_busy_acquire(vm_page_t m, int allocflags); 589 void vm_page_busy_downgrade(vm_page_t m); 590 int vm_page_busy_tryupgrade(vm_page_t m); 591 void vm_page_busy_sleep(vm_page_t m, const char *msg, bool nonshared); 592 void vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, 593 vm_pindex_t pindex, const char *wmesg, bool nonshared); 594 void vm_page_free(vm_page_t m); 595 void vm_page_free_zero(vm_page_t m); 596 597 void vm_page_activate (vm_page_t); 598 void vm_page_advise(vm_page_t m, int advice); 599 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int); 600 vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int); 601 vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t); 602 vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int, 603 vm_page_t); 604 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 605 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 606 vm_paddr_t boundary, vm_memattr_t memattr); 607 vm_page_t vm_page_alloc_contig_domain(vm_object_t object, 608 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low, 609 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 610 vm_memattr_t memattr); 611 vm_page_t vm_page_alloc_freelist(int, int); 612 vm_page_t vm_page_alloc_freelist_domain(int, int, int); 613 void vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set); 614 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose); 615 vm_page_t vm_page_grab(vm_object_t, vm_pindex_t, int); 616 vm_page_t vm_page_grab_unlocked(vm_object_t, vm_pindex_t, int); 617 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 618 vm_page_t *ma, int count); 619 int vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 620 int allocflags, vm_page_t *ma, int count); 621 int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 622 int allocflags); 623 int vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 624 vm_pindex_t pindex, int allocflags); 625 void vm_page_deactivate(vm_page_t); 626 void vm_page_deactivate_noreuse(vm_page_t); 627 void vm_page_dequeue(vm_page_t m); 628 void vm_page_dequeue_deferred(vm_page_t m); 629 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t); 630 void vm_page_free_invalid(vm_page_t); 631 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 632 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 633 void vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags); 634 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 635 void vm_page_invalid(vm_page_t m); 636 void vm_page_launder(vm_page_t m); 637 vm_page_t vm_page_lookup(vm_object_t, vm_pindex_t); 638 vm_page_t vm_page_next(vm_page_t m); 639 void vm_page_pqbatch_drain(void); 640 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue); 641 bool vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, 642 vm_page_astate_t new); 643 vm_page_t vm_page_prev(vm_page_t m); 644 bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m); 645 void vm_page_putfake(vm_page_t m); 646 void vm_page_readahead_finish(vm_page_t m); 647 bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, 648 vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 649 bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 650 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 651 void vm_page_reference(vm_page_t m); 652 #define VPR_TRYFREE 0x01 653 #define VPR_NOREUSE 0x02 654 void vm_page_release(vm_page_t m, int flags); 655 void vm_page_release_locked(vm_page_t m, int flags); 656 vm_page_t vm_page_relookup(vm_object_t, vm_pindex_t); 657 bool vm_page_remove(vm_page_t); 658 bool vm_page_remove_xbusy(vm_page_t); 659 int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t); 660 void vm_page_replace(vm_page_t mnew, vm_object_t object, 661 vm_pindex_t pindex, vm_page_t mold); 662 int vm_page_sbusied(vm_page_t m); 663 vm_page_t vm_page_scan_contig(u_long npages, vm_page_t m_start, 664 vm_page_t m_end, u_long alignment, vm_paddr_t boundary, int options); 665 vm_page_bits_t vm_page_set_dirty(vm_page_t m); 666 void vm_page_set_valid_range(vm_page_t m, int base, int size); 667 int vm_page_sleep_if_busy(vm_page_t m, const char *msg); 668 int vm_page_sleep_if_xbusy(vm_page_t m, const char *msg); 669 vm_offset_t vm_page_startup(vm_offset_t vaddr); 670 void vm_page_sunbusy(vm_page_t m); 671 bool vm_page_try_remove_all(vm_page_t m); 672 bool vm_page_try_remove_write(vm_page_t m); 673 int vm_page_trysbusy(vm_page_t m); 674 int vm_page_tryxbusy(vm_page_t m); 675 void vm_page_unhold_pages(vm_page_t *ma, int count); 676 void vm_page_unswappable(vm_page_t m); 677 void vm_page_unwire(vm_page_t m, uint8_t queue); 678 bool vm_page_unwire_noq(vm_page_t m); 679 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 680 void vm_page_wire(vm_page_t); 681 bool vm_page_wire_mapped(vm_page_t m); 682 void vm_page_xunbusy_hard(vm_page_t m); 683 void vm_page_xunbusy_hard_unchecked(vm_page_t m); 684 void vm_page_set_validclean (vm_page_t, int, int); 685 void vm_page_clear_dirty(vm_page_t, int, int); 686 void vm_page_set_invalid(vm_page_t, int, int); 687 void vm_page_valid(vm_page_t m); 688 int vm_page_is_valid(vm_page_t, int, int); 689 void vm_page_test_dirty(vm_page_t); 690 vm_page_bits_t vm_page_bits(int base, int size); 691 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 692 void vm_page_free_pages_toq(struct spglist *free, bool update_wire_count); 693 694 void vm_page_dirty_KBI(vm_page_t m); 695 void vm_page_lock_KBI(vm_page_t m, const char *file, int line); 696 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line); 697 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line); 698 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 699 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line); 700 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line); 701 #endif 702 703 #define vm_page_busy_fetch(m) atomic_load_int(&(m)->busy_lock) 704 705 #define vm_page_assert_busied(m) \ 706 KASSERT(vm_page_busied(m), \ 707 ("vm_page_assert_busied: page %p not busy @ %s:%d", \ 708 (m), __FILE__, __LINE__)) 709 710 #define vm_page_assert_sbusied(m) \ 711 KASSERT(vm_page_sbusied(m), \ 712 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \ 713 (m), __FILE__, __LINE__)) 714 715 #define vm_page_assert_unbusied(m) \ 716 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) != \ 717 VPB_CURTHREAD_EXCLUSIVE, \ 718 ("vm_page_assert_xbusied: page %p busy_lock %#x owned" \ 719 " by me @ %s:%d", \ 720 (m), (m)->busy_lock, __FILE__, __LINE__)); \ 721 722 #define vm_page_assert_xbusied_unchecked(m) do { \ 723 KASSERT(vm_page_xbusied(m), \ 724 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \ 725 (m), __FILE__, __LINE__)); \ 726 } while (0) 727 #define vm_page_assert_xbusied(m) do { \ 728 vm_page_assert_xbusied_unchecked(m); \ 729 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) == \ 730 VPB_CURTHREAD_EXCLUSIVE, \ 731 ("vm_page_assert_xbusied: page %p busy_lock %#x not owned" \ 732 " by me @ %s:%d", \ 733 (m), (m)->busy_lock, __FILE__, __LINE__)); \ 734 } while (0) 735 736 #define vm_page_busied(m) \ 737 (vm_page_busy_fetch(m) != VPB_UNBUSIED) 738 739 #define vm_page_sbusy(m) do { \ 740 if (!vm_page_trysbusy(m)) \ 741 panic("%s: page %p failed shared busying", __func__, \ 742 (m)); \ 743 } while (0) 744 745 #define vm_page_xbusied(m) \ 746 ((vm_page_busy_fetch(m) & VPB_SINGLE_EXCLUSIVE) != 0) 747 748 #define vm_page_busy_freed(m) \ 749 (vm_page_busy_fetch(m) == VPB_FREED) 750 751 #define vm_page_xbusy(m) do { \ 752 if (!vm_page_tryxbusy(m)) \ 753 panic("%s: page %p failed exclusive busying", __func__, \ 754 (m)); \ 755 } while (0) 756 757 /* Note: page m's lock must not be owned by the caller. */ 758 #define vm_page_xunbusy(m) do { \ 759 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 760 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 761 vm_page_xunbusy_hard(m); \ 762 } while (0) 763 #define vm_page_xunbusy_unchecked(m) do { \ 764 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 765 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 766 vm_page_xunbusy_hard_unchecked(m); \ 767 } while (0) 768 769 #ifdef INVARIANTS 770 void vm_page_object_busy_assert(vm_page_t m); 771 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) vm_page_object_busy_assert(m) 772 void vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits); 773 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \ 774 vm_page_assert_pga_writeable(m, bits) 775 /* 776 * Claim ownership of a page's xbusy state. In non-INVARIANTS kernels this 777 * operation is a no-op since ownership is not tracked. In particular 778 * this macro does not provide any synchronization with the previous owner. 779 */ 780 #define vm_page_xbusy_claim(m) do { \ 781 u_int _busy_lock; \ 782 \ 783 vm_page_assert_xbusied_unchecked((m)); \ 784 do { \ 785 _busy_lock = vm_page_busy_fetch(m); \ 786 } while (!atomic_cmpset_int(&(m)->busy_lock, _busy_lock, \ 787 (_busy_lock & VPB_BIT_FLAGMASK) | VPB_CURTHREAD_EXCLUSIVE)); \ 788 } while (0) 789 #else 790 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) (void)0 791 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0 792 #define vm_page_xbusy_claim(m) 793 #endif 794 795 #if BYTE_ORDER == BIG_ENDIAN 796 #define VM_PAGE_AFLAG_SHIFT 16 797 #else 798 #define VM_PAGE_AFLAG_SHIFT 0 799 #endif 800 801 /* 802 * Load a snapshot of a page's 32-bit atomic state. 803 */ 804 static inline vm_page_astate_t 805 vm_page_astate_load(vm_page_t m) 806 { 807 vm_page_astate_t a; 808 809 a._bits = atomic_load_32(&m->a._bits); 810 return (a); 811 } 812 813 /* 814 * Atomically compare and set a page's atomic state. 815 */ 816 static inline bool 817 vm_page_astate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 818 { 819 820 KASSERT(new.queue == PQ_INACTIVE || (new.flags & PGA_REQUEUE_HEAD) == 0, 821 ("%s: invalid head requeue request for page %p", __func__, m)); 822 KASSERT((new.flags & PGA_ENQUEUED) == 0 || new.queue != PQ_NONE, 823 ("%s: setting PGA_ENQUEUED with PQ_NONE in page %p", __func__, m)); 824 KASSERT(new._bits != old->_bits, 825 ("%s: bits are unchanged", __func__)); 826 827 return (atomic_fcmpset_32(&m->a._bits, &old->_bits, new._bits) != 0); 828 } 829 830 /* 831 * Clear the given bits in the specified page. 832 */ 833 static inline void 834 vm_page_aflag_clear(vm_page_t m, uint16_t bits) 835 { 836 uint32_t *addr, val; 837 838 /* 839 * Access the whole 32-bit word containing the aflags field with an 840 * atomic update. Parallel non-atomic updates to the other fields 841 * within this word are handled properly by the atomic update. 842 */ 843 addr = (void *)&m->a; 844 val = bits << VM_PAGE_AFLAG_SHIFT; 845 atomic_clear_32(addr, val); 846 } 847 848 /* 849 * Set the given bits in the specified page. 850 */ 851 static inline void 852 vm_page_aflag_set(vm_page_t m, uint16_t bits) 853 { 854 uint32_t *addr, val; 855 856 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits); 857 858 /* 859 * Access the whole 32-bit word containing the aflags field with an 860 * atomic update. Parallel non-atomic updates to the other fields 861 * within this word are handled properly by the atomic update. 862 */ 863 addr = (void *)&m->a; 864 val = bits << VM_PAGE_AFLAG_SHIFT; 865 atomic_set_32(addr, val); 866 } 867 868 /* 869 * vm_page_dirty: 870 * 871 * Set all bits in the page's dirty field. 872 * 873 * The object containing the specified page must be locked if the 874 * call is made from the machine-independent layer. 875 * 876 * See vm_page_clear_dirty_mask(). 877 */ 878 static __inline void 879 vm_page_dirty(vm_page_t m) 880 { 881 882 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */ 883 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS) 884 vm_page_dirty_KBI(m); 885 #else 886 m->dirty = VM_PAGE_BITS_ALL; 887 #endif 888 } 889 890 /* 891 * vm_page_undirty: 892 * 893 * Set page to not be dirty. Note: does not clear pmap modify bits 894 */ 895 static __inline void 896 vm_page_undirty(vm_page_t m) 897 { 898 899 VM_PAGE_OBJECT_BUSY_ASSERT(m); 900 m->dirty = 0; 901 } 902 903 static inline uint8_t 904 _vm_page_queue(vm_page_astate_t as) 905 { 906 907 if ((as.flags & PGA_DEQUEUE) != 0) 908 return (PQ_NONE); 909 return (as.queue); 910 } 911 912 /* 913 * vm_page_queue: 914 * 915 * Return the index of the queue containing m. 916 */ 917 static inline uint8_t 918 vm_page_queue(vm_page_t m) 919 { 920 921 return (_vm_page_queue(vm_page_astate_load(m))); 922 } 923 924 static inline bool 925 vm_page_active(vm_page_t m) 926 { 927 928 return (vm_page_queue(m) == PQ_ACTIVE); 929 } 930 931 static inline bool 932 vm_page_inactive(vm_page_t m) 933 { 934 935 return (vm_page_queue(m) == PQ_INACTIVE); 936 } 937 938 static inline bool 939 vm_page_in_laundry(vm_page_t m) 940 { 941 uint8_t queue; 942 943 queue = vm_page_queue(m); 944 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE); 945 } 946 947 /* 948 * vm_page_drop: 949 * 950 * Release a reference to a page and return the old reference count. 951 */ 952 static inline u_int 953 vm_page_drop(vm_page_t m, u_int val) 954 { 955 u_int old; 956 957 /* 958 * Synchronize with vm_page_free_prep(): ensure that all updates to the 959 * page structure are visible before it is freed. 960 */ 961 atomic_thread_fence_rel(); 962 old = atomic_fetchadd_int(&m->ref_count, -val); 963 KASSERT(old != VPRC_BLOCKED, 964 ("vm_page_drop: page %p has an invalid refcount value", m)); 965 return (old); 966 } 967 968 /* 969 * vm_page_wired: 970 * 971 * Perform a racy check to determine whether a reference prevents the page 972 * from being reclaimable. If the page's object is locked, and the page is 973 * unmapped and exclusively busied by the current thread, no new wirings 974 * may be created. 975 */ 976 static inline bool 977 vm_page_wired(vm_page_t m) 978 { 979 980 return (VPRC_WIRE_COUNT(m->ref_count) > 0); 981 } 982 983 static inline bool 984 vm_page_all_valid(vm_page_t m) 985 { 986 987 return (m->valid == VM_PAGE_BITS_ALL); 988 } 989 990 static inline bool 991 vm_page_none_valid(vm_page_t m) 992 { 993 994 return (m->valid == 0); 995 } 996 997 #endif /* _KERNEL */ 998 #endif /* !_VM_PAGE_ */ 999