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 the lock on the 96 * object that the page belongs to (O), the page lock (P), 97 * the per-domain lock for the free queues (F), or the page's queue 98 * lock (Q). The physical address of a page is used to select its page 99 * lock from a pool. The queue lock for a page depends on the value of 100 * its queue field and described in detail below. If a field is 101 * annotated below with two of these locks, then holding either lock is 102 * sufficient for read access, but both locks are required for write 103 * access. An annotation of (C) indicates that the field is immutable. 104 * 105 * In contrast, the synchronization of accesses to the page's 106 * dirty field is machine dependent (M). In the 107 * machine-independent layer, the lock on the object that the 108 * page belongs to must be held in order to operate on the field. 109 * However, the pmap layer is permitted to set all bits within 110 * the field without holding that lock. If the underlying 111 * architecture does not support atomic read-modify-write 112 * operations on the field's type, then the machine-independent 113 * layer uses a 32-bit atomic on the aligned 32-bit word that 114 * contains the dirty field. In the machine-independent layer, 115 * the implementation of read-modify-write operations on the 116 * field is encapsulated in vm_page_clear_dirty_mask(). 117 * 118 * The ref_count field tracks references to the page. References that 119 * prevent the page from being reclaimable are called wirings and are 120 * counted in the low bits of ref_count. The containing object's 121 * reference, if one exists, is counted using the VPRC_OBJREF bit in the 122 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to 123 * atomically check for wirings and prevent new wirings via 124 * pmap_extract_and_hold(). When a page belongs to an object, it may be 125 * wired only when the object is locked, or the page is busy, or by 126 * pmap_extract_and_hold(). As a result, if the object is locked and the 127 * page is not busy (or is exclusively busied by the current thread), and 128 * the page is unmapped, its wire count will not increase. The ref_count 129 * field is updated using atomic operations in most cases, except when it 130 * is known that no other references to the page exist, such as in the page 131 * allocator. A page may be present in the page queues, or even actively 132 * scanned by the page daemon, without an explicitly counted referenced. 133 * The page daemon must therefore handle the possibility of a concurrent 134 * free of the page. 135 * 136 * The busy lock is an embedded reader-writer lock which protects the 137 * page's contents and identity (i.e., its <object, pindex> tuple) and 138 * interlocks with the object lock (O). In particular, a page may be 139 * busied or unbusied only with the object write lock held. To avoid 140 * bloating the page structure, the busy lock lacks some of the 141 * features available to the kernel's general-purpose synchronization 142 * primitives. As a result, busy lock ordering rules are not verified, 143 * lock recursion is not detected, and an attempt to xbusy a busy page 144 * or sbusy an xbusy page results will trigger a panic rather than 145 * causing the thread to block. vm_page_sleep_if_busy() can be used to 146 * sleep until the page's busy state changes, after which the caller 147 * must re-lookup the page and re-evaluate its state. 148 * 149 * The queue field is the index of the page queue containing the page, 150 * or PQ_NONE if the page is not enqueued. The queue lock of a page is 151 * the page queue lock corresponding to the page queue index, or the 152 * page lock (P) for the page if it is not enqueued. To modify the 153 * queue field, the queue lock for the old value of the field must be 154 * held. There is one exception to this rule: the page daemon may 155 * transition the queue field from PQ_INACTIVE to PQ_NONE immediately 156 * prior to freeing a page during an inactive queue scan. At that 157 * point the page has already been physically dequeued and no other 158 * references to that vm_page structure exist. 159 * 160 * To avoid contention on page queue locks, page queue operations 161 * (enqueue, dequeue, requeue) are batched using per-CPU queues. A 162 * deferred operation is requested by inserting an entry into a batch 163 * queue; the entry is simply a pointer to the page, and the request 164 * type is encoded in the page's aflags field using the values in 165 * PGA_QUEUE_STATE_MASK. The type-stability of struct vm_pages is 166 * crucial to this scheme since the processing of entries in a given 167 * batch queue may be deferred indefinitely. In particular, a page may 168 * be freed before its pending batch queue entries have been processed. 169 * The page lock (P) must be held to schedule a batched queue 170 * operation, and the page queue lock must be held in order to process 171 * batch queue entries for the page queue. There is one exception to 172 * this rule: the thread freeing a page may schedule a dequeue without 173 * holding the page lock. In this scenario the only other thread which 174 * may hold a reference to the page is the page daemon, which is 175 * careful to avoid modifying the page's queue state once the dequeue 176 * has been requested by setting PGA_DEQUEUE. 177 */ 178 179 #if PAGE_SIZE == 4096 180 #define VM_PAGE_BITS_ALL 0xffu 181 typedef uint8_t vm_page_bits_t; 182 #elif PAGE_SIZE == 8192 183 #define VM_PAGE_BITS_ALL 0xffffu 184 typedef uint16_t vm_page_bits_t; 185 #elif PAGE_SIZE == 16384 186 #define VM_PAGE_BITS_ALL 0xffffffffu 187 typedef uint32_t vm_page_bits_t; 188 #elif PAGE_SIZE == 32768 189 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 190 typedef uint64_t vm_page_bits_t; 191 #endif 192 193 struct vm_page { 194 union { 195 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */ 196 struct { 197 SLIST_ENTRY(vm_page) ss; /* private slists */ 198 void *pv; 199 } s; 200 struct { 201 u_long p; 202 u_long v; 203 } memguard; 204 } plinks; 205 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */ 206 vm_object_t object; /* which object am I in (O) */ 207 vm_pindex_t pindex; /* offset into object (O,P) */ 208 vm_paddr_t phys_addr; /* physical address of page (C) */ 209 struct md_page md; /* machine dependent stuff */ 210 union { 211 u_int wire_count; 212 u_int ref_count; /* page references */ 213 }; 214 volatile u_int busy_lock; /* busy owners lock */ 215 uint16_t flags; /* page PG_* flags (P) */ 216 uint8_t order; /* index of the buddy queue (F) */ 217 uint8_t pool; /* vm_phys freepool index (F) */ 218 uint8_t aflags; /* access is atomic */ 219 uint8_t oflags; /* page VPO_* flags (O) */ 220 uint8_t queue; /* page queue index (Q) */ 221 int8_t psind; /* pagesizes[] index (O) */ 222 int8_t segind; /* vm_phys segment index (C) */ 223 u_char act_count; /* page usage count (P) */ 224 /* NOTE that these must support one bit per DEV_BSIZE in a page */ 225 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 226 vm_page_bits_t valid; /* map of valid DEV_BSIZE chunks (O) */ 227 vm_page_bits_t dirty; /* map of dirty DEV_BSIZE chunks (M) */ 228 }; 229 230 /* 231 * Special bits used in the ref_count field. 232 * 233 * ref_count is normally used to count wirings that prevent the page from being 234 * reclaimed, but also supports several special types of references that do not 235 * prevent reclamation. Accesses to the ref_count field must be atomic unless 236 * the page is unallocated. 237 * 238 * VPRC_OBJREF is the reference held by the containing object. It can set or 239 * cleared only when the corresponding object's write lock is held. 240 * 241 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while 242 * attempting to tear down all mappings of a given page. The page lock and 243 * object write lock must both be held in order to set or clear this bit. 244 */ 245 #define VPRC_BLOCKED 0x40000000u /* mappings are being removed */ 246 #define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */ 247 #define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF)) 248 #define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF)) 249 250 /* 251 * Page flags stored in oflags: 252 * 253 * Access to these page flags is synchronized by the lock on the object 254 * containing the page (O). 255 * 256 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG) 257 * indicates that the page is not under PV management but 258 * otherwise should be treated as a normal page. Pages not 259 * under PV management cannot be paged out via the 260 * object/vm_page_t because there is no knowledge of their pte 261 * mappings, and such pages are also not on any PQ queue. 262 * 263 */ 264 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */ 265 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */ 266 #define VPO_UNMANAGED 0x04 /* no PV management for page */ 267 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */ 268 #define VPO_NOSYNC 0x10 /* do not collect for syncer */ 269 270 /* 271 * Busy page implementation details. 272 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation, 273 * even if the support for owner identity is removed because of size 274 * constraints. Checks on lock recursion are then not possible, while the 275 * lock assertions effectiveness is someway reduced. 276 */ 277 #define VPB_BIT_SHARED 0x01 278 #define VPB_BIT_EXCLUSIVE 0x02 279 #define VPB_BIT_WAITERS 0x04 280 #define VPB_BIT_FLAGMASK \ 281 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS) 282 283 #define VPB_SHARERS_SHIFT 3 284 #define VPB_SHARERS(x) \ 285 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT) 286 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED) 287 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT) 288 289 #define VPB_SINGLE_EXCLUSIVER VPB_BIT_EXCLUSIVE 290 291 #define VPB_UNBUSIED VPB_SHARERS_WORD(0) 292 293 #define PQ_NONE 255 294 #define PQ_INACTIVE 0 295 #define PQ_ACTIVE 1 296 #define PQ_LAUNDRY 2 297 #define PQ_UNSWAPPABLE 3 298 #define PQ_COUNT 4 299 300 #ifndef VM_PAGE_HAVE_PGLIST 301 TAILQ_HEAD(pglist, vm_page); 302 #define VM_PAGE_HAVE_PGLIST 303 #endif 304 SLIST_HEAD(spglist, vm_page); 305 306 #ifdef _KERNEL 307 extern vm_page_t bogus_page; 308 #endif /* _KERNEL */ 309 310 extern struct mtx_padalign pa_lock[]; 311 312 #if defined(__arm__) 313 #define PDRSHIFT PDR_SHIFT 314 #elif !defined(PDRSHIFT) 315 #define PDRSHIFT 21 316 #endif 317 318 #define pa_index(pa) ((pa) >> PDRSHIFT) 319 #define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT])) 320 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa))) 321 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa)) 322 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa)) 323 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa)) 324 #define PA_UNLOCK_COND(pa) \ 325 do { \ 326 if ((pa) != 0) { \ 327 PA_UNLOCK((pa)); \ 328 (pa) = 0; \ 329 } \ 330 } while (0) 331 332 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a)) 333 334 #if defined(KLD_MODULE) && !defined(KLD_TIED) 335 #define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE) 336 #define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE) 337 #define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE) 338 #else /* !KLD_MODULE */ 339 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m)))) 340 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m))) 341 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m))) 342 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m))) 343 #endif 344 #if defined(INVARIANTS) 345 #define vm_page_assert_locked(m) \ 346 vm_page_assert_locked_KBI((m), __FILE__, __LINE__) 347 #define vm_page_lock_assert(m, a) \ 348 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__) 349 #else 350 #define vm_page_assert_locked(m) 351 #define vm_page_lock_assert(m, a) 352 #endif 353 354 /* 355 * The vm_page's aflags are updated using atomic operations. To set or clear 356 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear() 357 * must be used. Neither these flags nor these functions are part of the KBI. 358 * 359 * PGA_REFERENCED may be cleared only if the page is locked. It is set by 360 * both the MI and MD VM layers. However, kernel loadable modules should not 361 * directly set this flag. They should call vm_page_reference() instead. 362 * 363 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). 364 * When it does so, the object must be locked, or the page must be 365 * exclusive busied. The MI VM layer must never access this flag 366 * directly. Instead, it should call pmap_page_is_write_mapped(). 367 * 368 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has 369 * at least one executable mapping. It is not consumed by the MI VM layer. 370 * 371 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed 372 * from a page queue, respectively. It determines whether the plinks.q field 373 * of the page is valid. To set or clear this flag, the queue lock for the 374 * page must be held: the page queue lock corresponding to the page's "queue" 375 * field if its value is not PQ_NONE, and the page lock otherwise. 376 * 377 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page 378 * queue, and cleared when the dequeue request is processed. A page may 379 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue 380 * is requested after the page is scheduled to be enqueued but before it is 381 * actually inserted into the page queue. For allocated pages, the page lock 382 * must be held to set this flag, but it may be set by vm_page_free_prep() 383 * without the page lock held. The page queue lock must be held to clear the 384 * PGA_DEQUEUE flag. 385 * 386 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued 387 * in its page queue. The page lock must be held to set this flag, and the 388 * queue lock for the page must be held to clear it. 389 * 390 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of 391 * the inactive queue, thus bypassing LRU. The page lock must be held to 392 * set this flag, and the queue lock for the page must be held to clear it. 393 */ 394 #define PGA_WRITEABLE 0x01 /* page may be mapped writeable */ 395 #define PGA_REFERENCED 0x02 /* page has been referenced */ 396 #define PGA_EXECUTABLE 0x04 /* page may be mapped executable */ 397 #define PGA_ENQUEUED 0x08 /* page is enqueued in a page queue */ 398 #define PGA_DEQUEUE 0x10 /* page is due to be dequeued */ 399 #define PGA_REQUEUE 0x20 /* page is due to be requeued */ 400 #define PGA_REQUEUE_HEAD 0x40 /* page requeue should bypass LRU */ 401 402 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_DEQUEUE | PGA_REQUEUE | \ 403 PGA_REQUEUE_HEAD) 404 405 /* 406 * Page flags. If changed at any other time than page allocation or 407 * freeing, the modification must be protected by the vm_page lock. 408 * 409 * The PG_PCPU_CACHE flag is set at allocation time if the page was 410 * allocated from a per-CPU cache. It is cleared the next time that the 411 * page is allocated from the physical memory allocator. 412 */ 413 #define PG_PCPU_CACHE 0x0001 /* was allocated from per-CPU caches */ 414 #define PG_FICTITIOUS 0x0004 /* physical page doesn't exist */ 415 #define PG_ZERO 0x0008 /* page is zeroed */ 416 #define PG_MARKER 0x0010 /* special queue marker page */ 417 #define PG_NODUMP 0x0080 /* don't include this page in a dump */ 418 419 /* 420 * Misc constants. 421 */ 422 #define ACT_DECLINE 1 423 #define ACT_ADVANCE 3 424 #define ACT_INIT 5 425 #define ACT_MAX 64 426 427 #ifdef _KERNEL 428 429 #include <sys/systm.h> 430 431 #include <machine/atomic.h> 432 433 /* 434 * Each pageable resident page falls into one of five lists: 435 * 436 * free 437 * Available for allocation now. 438 * 439 * inactive 440 * Low activity, candidates for reclamation. 441 * This list is approximately LRU ordered. 442 * 443 * laundry 444 * This is the list of pages that should be 445 * paged out next. 446 * 447 * unswappable 448 * Dirty anonymous pages that cannot be paged 449 * out because no swap device is configured. 450 * 451 * active 452 * Pages that are "active", i.e., they have been 453 * recently referenced. 454 * 455 */ 456 457 extern vm_page_t vm_page_array; /* First resident page in table */ 458 extern long vm_page_array_size; /* number of vm_page_t's */ 459 extern long first_page; /* first physical page number */ 460 461 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 462 463 /* 464 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory 465 * page to which the given physical address belongs. The correct vm_page_t 466 * object is returned for addresses that are not page-aligned. 467 */ 468 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 469 470 /* 471 * Page allocation parameters for vm_page for the functions 472 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and 473 * vm_page_alloc_freelist(). Some functions support only a subset 474 * of the flags, and ignore others, see the flags legend. 475 * 476 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*() 477 * and the vm_page_grab*() functions. See these functions for details. 478 * 479 * Bits 0 - 1 define class. 480 * Bits 2 - 15 dedicated for flags. 481 * Legend: 482 * (a) - vm_page_alloc() supports the flag. 483 * (c) - vm_page_alloc_contig() supports the flag. 484 * (f) - vm_page_alloc_freelist() supports the flag. 485 * (g) - vm_page_grab() supports the flag. 486 * (p) - vm_page_grab_pages() supports the flag. 487 * Bits above 15 define the count of additional pages that the caller 488 * intends to allocate. 489 */ 490 #define VM_ALLOC_NORMAL 0 491 #define VM_ALLOC_INTERRUPT 1 492 #define VM_ALLOC_SYSTEM 2 493 #define VM_ALLOC_CLASS_MASK 3 494 #define VM_ALLOC_WAITOK 0x0008 /* (acf) Sleep and retry */ 495 #define VM_ALLOC_WAITFAIL 0x0010 /* (acf) Sleep and return error */ 496 #define VM_ALLOC_WIRED 0x0020 /* (acfgp) Allocate a wired page */ 497 #define VM_ALLOC_ZERO 0x0040 /* (acfgp) Allocate a prezeroed page */ 498 #define VM_ALLOC_NOOBJ 0x0100 /* (acg) No associated object */ 499 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */ 500 #define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */ 501 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */ 502 #define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */ 503 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */ 504 #define VM_ALLOC_NOWAIT 0x8000 /* (acfgp) Do not sleep */ 505 #define VM_ALLOC_COUNT_SHIFT 16 506 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT) 507 508 #ifdef M_NOWAIT 509 static inline int 510 malloc2vm_flags(int malloc_flags) 511 { 512 int pflags; 513 514 KASSERT((malloc_flags & M_USE_RESERVE) == 0 || 515 (malloc_flags & M_NOWAIT) != 0, 516 ("M_USE_RESERVE requires M_NOWAIT")); 517 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT : 518 VM_ALLOC_SYSTEM; 519 if ((malloc_flags & M_ZERO) != 0) 520 pflags |= VM_ALLOC_ZERO; 521 if ((malloc_flags & M_NODUMP) != 0) 522 pflags |= VM_ALLOC_NODUMP; 523 if ((malloc_flags & M_NOWAIT)) 524 pflags |= VM_ALLOC_NOWAIT; 525 if ((malloc_flags & M_WAITOK)) 526 pflags |= VM_ALLOC_WAITOK; 527 return (pflags); 528 } 529 #endif 530 531 /* 532 * Predicates supported by vm_page_ps_test(): 533 * 534 * PS_ALL_DIRTY is true only if the entire (super)page is dirty. 535 * However, it can be spuriously false when the (super)page has become 536 * dirty in the pmap but that information has not been propagated to the 537 * machine-independent layer. 538 */ 539 #define PS_ALL_DIRTY 0x1 540 #define PS_ALL_VALID 0x2 541 #define PS_NONE_BUSY 0x4 542 543 int vm_page_busy_acquire(vm_page_t m, int allocflags); 544 void vm_page_busy_downgrade(vm_page_t m); 545 void vm_page_busy_sleep(vm_page_t m, const char *msg, bool nonshared); 546 void vm_page_free(vm_page_t m); 547 void vm_page_free_zero(vm_page_t m); 548 549 void vm_page_activate (vm_page_t); 550 void vm_page_advise(vm_page_t m, int advice); 551 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int); 552 vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int); 553 vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t); 554 vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int, 555 vm_page_t); 556 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 557 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 558 vm_paddr_t boundary, vm_memattr_t memattr); 559 vm_page_t vm_page_alloc_contig_domain(vm_object_t object, 560 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low, 561 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 562 vm_memattr_t memattr); 563 vm_page_t vm_page_alloc_freelist(int, int); 564 vm_page_t vm_page_alloc_freelist_domain(int, int, int); 565 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose); 566 void vm_page_change_lock(vm_page_t m, struct mtx **mtx); 567 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int); 568 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 569 vm_page_t *ma, int count); 570 int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 571 int allocflags); 572 void vm_page_deactivate(vm_page_t); 573 void vm_page_deactivate_noreuse(vm_page_t); 574 void vm_page_dequeue(vm_page_t m); 575 void vm_page_dequeue_deferred(vm_page_t m); 576 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t); 577 bool vm_page_free_prep(vm_page_t m); 578 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 579 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 580 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 581 void vm_page_launder(vm_page_t m); 582 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t); 583 vm_page_t vm_page_next(vm_page_t m); 584 int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *); 585 void vm_page_pqbatch_drain(void); 586 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue); 587 vm_page_t vm_page_prev(vm_page_t m); 588 bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m); 589 void vm_page_putfake(vm_page_t m); 590 void vm_page_readahead_finish(vm_page_t m); 591 bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, 592 vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 593 bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 594 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 595 void vm_page_reference(vm_page_t m); 596 #define VPR_TRYFREE 0x01 597 #define VPR_NOREUSE 0x02 598 void vm_page_release(vm_page_t m, int flags); 599 void vm_page_release_locked(vm_page_t m, int flags); 600 bool vm_page_remove(vm_page_t); 601 int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t); 602 vm_page_t vm_page_replace(vm_page_t mnew, vm_object_t object, 603 vm_pindex_t pindex); 604 void vm_page_requeue(vm_page_t m); 605 int vm_page_sbusied(vm_page_t m); 606 vm_page_t vm_page_scan_contig(u_long npages, vm_page_t m_start, 607 vm_page_t m_end, u_long alignment, vm_paddr_t boundary, int options); 608 void vm_page_set_valid_range(vm_page_t m, int base, int size); 609 int vm_page_sleep_if_busy(vm_page_t m, const char *msg); 610 int vm_page_sleep_if_xbusy(vm_page_t m, const char *msg); 611 vm_offset_t vm_page_startup(vm_offset_t vaddr); 612 void vm_page_sunbusy(vm_page_t m); 613 void vm_page_swapqueue(vm_page_t m, uint8_t oldq, uint8_t newq); 614 bool vm_page_try_remove_all(vm_page_t m); 615 bool vm_page_try_remove_write(vm_page_t m); 616 int vm_page_trysbusy(vm_page_t m); 617 void vm_page_unhold_pages(vm_page_t *ma, int count); 618 void vm_page_unswappable(vm_page_t m); 619 void vm_page_unwire(vm_page_t m, uint8_t queue); 620 bool vm_page_unwire_noq(vm_page_t m); 621 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 622 void vm_page_wire(vm_page_t); 623 bool vm_page_wire_mapped(vm_page_t m); 624 void vm_page_xunbusy_hard(vm_page_t m); 625 void vm_page_set_validclean (vm_page_t, int, int); 626 void vm_page_clear_dirty (vm_page_t, int, int); 627 void vm_page_set_invalid (vm_page_t, int, int); 628 int vm_page_is_valid (vm_page_t, int, int); 629 void vm_page_test_dirty (vm_page_t); 630 vm_page_bits_t vm_page_bits(int base, int size); 631 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 632 void vm_page_free_toq(vm_page_t m); 633 void vm_page_free_pages_toq(struct spglist *free, bool update_wire_count); 634 635 void vm_page_dirty_KBI(vm_page_t m); 636 void vm_page_lock_KBI(vm_page_t m, const char *file, int line); 637 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line); 638 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line); 639 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) 640 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line); 641 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line); 642 #endif 643 644 #define vm_page_assert_sbusied(m) \ 645 KASSERT(vm_page_sbusied(m), \ 646 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \ 647 (m), __FILE__, __LINE__)) 648 649 #define vm_page_assert_unbusied(m) \ 650 KASSERT(!vm_page_busied(m), \ 651 ("vm_page_assert_unbusied: page %p busy @ %s:%d", \ 652 (m), __FILE__, __LINE__)) 653 654 #define vm_page_assert_xbusied(m) \ 655 KASSERT(vm_page_xbusied(m), \ 656 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \ 657 (m), __FILE__, __LINE__)) 658 659 #define vm_page_busied(m) \ 660 ((m)->busy_lock != VPB_UNBUSIED) 661 662 #define vm_page_sbusy(m) do { \ 663 if (!vm_page_trysbusy(m)) \ 664 panic("%s: page %p failed shared busying", __func__, \ 665 (m)); \ 666 } while (0) 667 668 #define vm_page_tryxbusy(m) \ 669 (atomic_cmpset_acq_int(&(m)->busy_lock, VPB_UNBUSIED, \ 670 VPB_SINGLE_EXCLUSIVER)) 671 672 #define vm_page_xbusied(m) \ 673 (((m)->busy_lock & VPB_SINGLE_EXCLUSIVER) != 0) 674 675 #define vm_page_xbusy(m) do { \ 676 if (!vm_page_tryxbusy(m)) \ 677 panic("%s: page %p failed exclusive busying", __func__, \ 678 (m)); \ 679 } while (0) 680 681 /* Note: page m's lock must not be owned by the caller. */ 682 #define vm_page_xunbusy(m) do { \ 683 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 684 VPB_SINGLE_EXCLUSIVER, VPB_UNBUSIED)) \ 685 vm_page_xunbusy_hard(m); \ 686 } while (0) 687 688 #ifdef INVARIANTS 689 void vm_page_object_lock_assert(vm_page_t m); 690 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m) 691 void vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits); 692 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \ 693 vm_page_assert_pga_writeable(m, bits) 694 #else 695 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0 696 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0 697 #endif 698 699 /* 700 * We want to use atomic updates for the aflags field, which is 8 bits wide. 701 * However, not all architectures support atomic operations on 8-bit 702 * destinations. In order that we can easily use a 32-bit operation, we 703 * require that the aflags field be 32-bit aligned. 704 */ 705 _Static_assert(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0, 706 "aflags field is not 32-bit aligned"); 707 708 /* 709 * We want to be able to update the aflags and queue fields atomically in 710 * the same operation. 711 */ 712 _Static_assert(offsetof(struct vm_page, aflags) / sizeof(uint32_t) == 713 offsetof(struct vm_page, queue) / sizeof(uint32_t), 714 "aflags and queue fields do not belong to the same 32-bit word"); 715 _Static_assert(offsetof(struct vm_page, queue) % sizeof(uint32_t) == 2, 716 "queue field is at an unexpected offset"); 717 _Static_assert(sizeof(((struct vm_page *)NULL)->queue) == 1, 718 "queue field has an unexpected size"); 719 720 #if BYTE_ORDER == LITTLE_ENDIAN 721 #define VM_PAGE_AFLAG_SHIFT 0 722 #define VM_PAGE_QUEUE_SHIFT 16 723 #else 724 #define VM_PAGE_AFLAG_SHIFT 24 725 #define VM_PAGE_QUEUE_SHIFT 8 726 #endif 727 #define VM_PAGE_QUEUE_MASK (0xff << VM_PAGE_QUEUE_SHIFT) 728 729 /* 730 * Clear the given bits in the specified page. 731 */ 732 static inline void 733 vm_page_aflag_clear(vm_page_t m, uint8_t bits) 734 { 735 uint32_t *addr, val; 736 737 /* 738 * The PGA_REFERENCED flag can only be cleared if the page is locked. 739 */ 740 if ((bits & PGA_REFERENCED) != 0) 741 vm_page_assert_locked(m); 742 743 /* 744 * Access the whole 32-bit word containing the aflags field with an 745 * atomic update. Parallel non-atomic updates to the other fields 746 * within this word are handled properly by the atomic update. 747 */ 748 addr = (void *)&m->aflags; 749 val = bits << VM_PAGE_AFLAG_SHIFT; 750 atomic_clear_32(addr, val); 751 } 752 753 /* 754 * Set the given bits in the specified page. 755 */ 756 static inline void 757 vm_page_aflag_set(vm_page_t m, uint8_t bits) 758 { 759 uint32_t *addr, val; 760 761 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits); 762 763 /* 764 * Access the whole 32-bit word containing the aflags field with an 765 * atomic update. Parallel non-atomic updates to the other fields 766 * within this word are handled properly by the atomic update. 767 */ 768 addr = (void *)&m->aflags; 769 val = bits << VM_PAGE_AFLAG_SHIFT; 770 atomic_set_32(addr, val); 771 } 772 773 /* 774 * Atomically update the queue state of the page. The operation fails if 775 * any of the queue flags in "fflags" are set or if the "queue" field of 776 * the page does not match the expected value; if the operation is 777 * successful, the flags in "nflags" are set and all other queue state 778 * flags are cleared. 779 */ 780 static inline bool 781 vm_page_pqstate_cmpset(vm_page_t m, uint32_t oldq, uint32_t newq, 782 uint32_t fflags, uint32_t nflags) 783 { 784 uint32_t *addr, nval, oval, qsmask; 785 786 fflags <<= VM_PAGE_AFLAG_SHIFT; 787 nflags <<= VM_PAGE_AFLAG_SHIFT; 788 newq <<= VM_PAGE_QUEUE_SHIFT; 789 oldq <<= VM_PAGE_QUEUE_SHIFT; 790 qsmask = ((PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD) << 791 VM_PAGE_AFLAG_SHIFT) | VM_PAGE_QUEUE_MASK; 792 793 addr = (void *)&m->aflags; 794 oval = atomic_load_32(addr); 795 do { 796 if ((oval & fflags) != 0) 797 return (false); 798 if ((oval & VM_PAGE_QUEUE_MASK) != oldq) 799 return (false); 800 nval = (oval & ~qsmask) | nflags | newq; 801 } while (!atomic_fcmpset_32(addr, &oval, nval)); 802 803 return (true); 804 } 805 806 /* 807 * vm_page_dirty: 808 * 809 * Set all bits in the page's dirty field. 810 * 811 * The object containing the specified page must be locked if the 812 * call is made from the machine-independent layer. 813 * 814 * See vm_page_clear_dirty_mask(). 815 */ 816 static __inline void 817 vm_page_dirty(vm_page_t m) 818 { 819 820 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */ 821 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS) 822 vm_page_dirty_KBI(m); 823 #else 824 m->dirty = VM_PAGE_BITS_ALL; 825 #endif 826 } 827 828 /* 829 * vm_page_undirty: 830 * 831 * Set page to not be dirty. Note: does not clear pmap modify bits 832 */ 833 static __inline void 834 vm_page_undirty(vm_page_t m) 835 { 836 837 VM_PAGE_OBJECT_LOCK_ASSERT(m); 838 m->dirty = 0; 839 } 840 841 static inline void 842 vm_page_replace_checked(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex, 843 vm_page_t mold) 844 { 845 vm_page_t mret; 846 847 mret = vm_page_replace(mnew, object, pindex); 848 KASSERT(mret == mold, 849 ("invalid page replacement, mold=%p, mret=%p", mold, mret)); 850 851 /* Unused if !INVARIANTS. */ 852 (void)mold; 853 (void)mret; 854 } 855 856 /* 857 * vm_page_queue: 858 * 859 * Return the index of the queue containing m. This index is guaranteed 860 * not to change while the page lock is held. 861 */ 862 static inline uint8_t 863 vm_page_queue(vm_page_t m) 864 { 865 866 vm_page_assert_locked(m); 867 868 if ((m->aflags & PGA_DEQUEUE) != 0) 869 return (PQ_NONE); 870 atomic_thread_fence_acq(); 871 return (m->queue); 872 } 873 874 static inline bool 875 vm_page_active(vm_page_t m) 876 { 877 878 return (vm_page_queue(m) == PQ_ACTIVE); 879 } 880 881 static inline bool 882 vm_page_inactive(vm_page_t m) 883 { 884 885 return (vm_page_queue(m) == PQ_INACTIVE); 886 } 887 888 static inline bool 889 vm_page_in_laundry(vm_page_t m) 890 { 891 uint8_t queue; 892 893 queue = vm_page_queue(m); 894 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE); 895 } 896 897 /* 898 * vm_page_drop: 899 * 900 * Release a reference to a page and return the old reference count. 901 */ 902 static inline u_int 903 vm_page_drop(vm_page_t m, u_int val) 904 { 905 u_int old; 906 907 /* 908 * Synchronize with vm_page_free_prep(): ensure that all updates to the 909 * page structure are visible before it is freed. 910 */ 911 atomic_thread_fence_rel(); 912 old = atomic_fetchadd_int(&m->ref_count, -val); 913 KASSERT(old != VPRC_BLOCKED, 914 ("vm_page_drop: page %p has an invalid refcount value", m)); 915 return (old); 916 } 917 918 /* 919 * vm_page_wired: 920 * 921 * Perform a racy check to determine whether a reference prevents the page 922 * from being reclaimable. If the page's object is locked, and the page is 923 * unmapped and unbusied or exclusively busied by the current thread, no 924 * new wirings may be created. 925 */ 926 static inline bool 927 vm_page_wired(vm_page_t m) 928 { 929 930 return (VPRC_WIRE_COUNT(m->ref_count) > 0); 931 } 932 933 #endif /* _KERNEL */ 934 #endif /* !_VM_PAGE_ */ 935