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 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Resident memory system definitions. 63 */ 64 65 #ifndef _VM_PAGE_ 66 #define _VM_PAGE_ 67 68 #include <vm/pmap.h> 69 #include <vm/_vm_phys.h> 70 71 /* 72 * Management of resident (logical) pages. 73 * 74 * A small structure is kept for each resident 75 * page, indexed by page number. Each structure 76 * is an element of several collections: 77 * 78 * A radix tree used to quickly 79 * perform object/offset lookups 80 * 81 * An ordered list of pages due for pageout. 82 * 83 * In addition, the structure contains the object 84 * and offset to which this page belongs (for pageout), 85 * and sundry status bits. 86 * 87 * In general, operations on this structure's mutable fields are 88 * synchronized using either one of or a combination of locks. If a 89 * field is annotated with two of these locks then holding either is 90 * sufficient for read access but both are required for write access. 91 * The queue lock for a page depends on the value of its queue field and is 92 * described in detail below. 93 * 94 * The following annotations are possible: 95 * (A) the field must be accessed using atomic(9) and may require 96 * additional synchronization. 97 * (B) the page busy lock. 98 * (C) the field is immutable. 99 * (F) the per-domain lock for the free queues. 100 * (M) Machine dependent, defined by pmap layer. 101 * (O) the object that the page belongs to. 102 * (Q) the page's queue lock. 103 * 104 * The busy lock is an embedded reader-writer lock that protects the 105 * page's contents and identity (i.e., its <object, pindex> tuple) as 106 * well as certain valid/dirty modifications. To avoid bloating the 107 * the page structure, the busy lock lacks some of the features available 108 * the kernel's general-purpose synchronization primitives. As a result, 109 * busy lock ordering rules are not verified, lock recursion is not 110 * detected, and an attempt to xbusy a busy page or sbusy an xbusy page 111 * results will trigger a panic rather than causing the thread to block. 112 * vm_page_sleep_if_busy() can be used to sleep until the page's busy 113 * state changes, after which the caller must re-lookup the page and 114 * re-evaluate its state. vm_page_busy_acquire() will block until 115 * the lock is acquired. 116 * 117 * The valid field is protected by the page busy lock (B) and object 118 * lock (O). Transitions from invalid to valid are generally done 119 * via I/O or zero filling and do not require the object lock. 120 * These must be protected with the busy lock to prevent page-in or 121 * creation races. Page invalidation generally happens as a result 122 * of truncate or msync. When invalidated, pages must not be present 123 * in pmap and must hold the object lock to prevent concurrent 124 * speculative read-only mappings that do not require busy. I/O 125 * routines may check for validity without a lock if they are prepared 126 * to handle invalidation races with higher level locks (vnode) or are 127 * unconcerned with races so long as they hold a reference to prevent 128 * recycling. When a valid bit is set while holding a shared busy 129 * lock (A) atomic operations are used to protect against concurrent 130 * modification. 131 * 132 * In contrast, the synchronization of accesses to the page's 133 * dirty field is a mix of machine dependent (M) and busy (B). In 134 * the machine-independent layer, the page busy must be held to 135 * operate on the field. However, the pmap layer is permitted to 136 * set all bits within the field without holding that lock. If the 137 * underlying architecture does not support atomic read-modify-write 138 * operations on the field's type, then the machine-independent 139 * layer uses a 32-bit atomic on the aligned 32-bit word that 140 * contains the dirty field. In the machine-independent layer, 141 * the implementation of read-modify-write operations on the 142 * field is encapsulated in vm_page_clear_dirty_mask(). An 143 * exclusive busy lock combined with pmap_remove_{write/all}() is the 144 * only way to ensure a page can not become dirty. I/O generally 145 * removes the page from pmap to ensure exclusive access and atomic 146 * writes. 147 * 148 * The ref_count field tracks references to the page. References that 149 * prevent the page from being reclaimable are called wirings and are 150 * counted in the low bits of ref_count. The containing object's 151 * reference, if one exists, is counted using the VPRC_OBJREF bit in the 152 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to 153 * atomically check for wirings and prevent new wirings via 154 * pmap_extract_and_hold(). When a page belongs to an object, it may be 155 * wired only when the object is locked, or the page is busy, or by 156 * pmap_extract_and_hold(). As a result, if the object is locked and the 157 * page is not busy (or is exclusively busied by the current thread), and 158 * the page is unmapped, its wire count will not increase. The ref_count 159 * field is updated using atomic operations in most cases, except when it 160 * is known that no other references to the page exist, such as in the page 161 * allocator. A page may be present in the page queues, or even actively 162 * scanned by the page daemon, without an explicitly counted referenced. 163 * The page daemon must therefore handle the possibility of a concurrent 164 * free of the page. 165 * 166 * The queue state of a page consists of the queue and act_count fields of 167 * its atomically updated state, and the subset of atomic flags specified 168 * by PGA_QUEUE_STATE_MASK. The queue field contains the page's page queue 169 * index, or PQ_NONE if it does not belong to a page queue. To modify the 170 * queue field, the page queue lock corresponding to the old value must be 171 * held, unless that value is PQ_NONE, in which case the queue index must 172 * be updated using an atomic RMW operation. There is one exception to 173 * this rule: the page daemon may transition the queue field from 174 * PQ_INACTIVE to PQ_NONE immediately prior to freeing the page during an 175 * inactive queue scan. At that point the page is already dequeued and no 176 * other references to that vm_page structure can exist. The PGA_ENQUEUED 177 * flag, when set, indicates that the page structure is physically inserted 178 * into the queue corresponding to the page's queue index, and may only be 179 * set or cleared with the corresponding page queue lock held. 180 * 181 * To avoid contention on page queue locks, page queue operations (enqueue, 182 * dequeue, requeue) are batched using fixed-size per-CPU queues. A 183 * deferred operation is requested by setting one of the flags in 184 * PGA_QUEUE_OP_MASK and inserting an entry into a batch queue. When a 185 * queue is full, an attempt to insert a new entry will lock the page 186 * queues and trigger processing of the pending entries. The 187 * type-stability of vm_page structures is crucial to this scheme since the 188 * processing of entries in a given batch queue may be deferred 189 * indefinitely. In particular, a page may be freed with pending batch 190 * queue entries. The page queue operation flags must be set using atomic 191 * RWM operations. 192 */ 193 194 #if PAGE_SIZE == 4096 195 #define VM_PAGE_BITS_ALL 0xffu 196 typedef uint8_t vm_page_bits_t; 197 #elif PAGE_SIZE == 8192 198 #define VM_PAGE_BITS_ALL 0xffffu 199 typedef uint16_t vm_page_bits_t; 200 #elif PAGE_SIZE == 16384 201 #define VM_PAGE_BITS_ALL 0xffffffffu 202 typedef uint32_t vm_page_bits_t; 203 #elif PAGE_SIZE == 32768 204 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu 205 typedef uint64_t vm_page_bits_t; 206 #endif 207 208 typedef union vm_page_astate { 209 struct { 210 uint16_t flags; 211 uint8_t queue; 212 uint8_t act_count; 213 }; 214 uint32_t _bits; 215 } vm_page_astate_t; 216 217 struct vm_page { 218 union { 219 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */ 220 struct { 221 SLIST_ENTRY(vm_page) ss; /* private slists */ 222 } s; 223 struct { 224 u_long p; 225 u_long v; 226 } memguard; 227 struct { 228 void *slab; 229 void *zone; 230 } uma; 231 } plinks; 232 vm_object_t object; /* which object am I in (O) */ 233 vm_pindex_t pindex; /* offset into object (O,P) */ 234 vm_paddr_t phys_addr; /* physical address of page (C) */ 235 struct md_page md; /* machine dependent stuff */ 236 u_int ref_count; /* page references (A) */ 237 u_int busy_lock; /* busy owners lock (A) */ 238 union vm_page_astate a; /* state accessed atomically (A) */ 239 uint8_t order; /* index of the buddy queue (F) */ 240 uint8_t pool; /* vm_phys freepool index (F) */ 241 uint8_t flags; /* page PG_* flags (P) */ 242 uint8_t oflags; /* page VPO_* flags (O) */ 243 int8_t psind; /* pagesizes[] index (O) */ 244 int8_t segind; /* vm_phys segment index (C) */ 245 /* NOTE that these must support one bit per DEV_BSIZE in a page */ 246 /* so, on normal X86 kernels, they must be at least 8 bits wide */ 247 vm_page_bits_t valid; /* valid DEV_BSIZE chunk map (O,B) */ 248 vm_page_bits_t dirty; /* dirty DEV_BSIZE chunk map (M,B) */ 249 }; 250 251 /* 252 * Special bits used in the ref_count field. 253 * 254 * ref_count is normally used to count wirings that prevent the page from being 255 * reclaimed, but also supports several special types of references that do not 256 * prevent reclamation. Accesses to the ref_count field must be atomic unless 257 * the page is unallocated. 258 * 259 * VPRC_OBJREF is the reference held by the containing object. It can set or 260 * cleared only when the corresponding object's write lock is held. 261 * 262 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while 263 * attempting to tear down all mappings of a given page. The page busy lock and 264 * object write lock must both be held in order to set or clear this bit. 265 */ 266 #define VPRC_BLOCKED 0x40000000u /* mappings are being removed */ 267 #define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */ 268 #define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF)) 269 #define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF)) 270 271 /* 272 * Page flags stored in oflags: 273 * 274 * Access to these page flags is synchronized by the lock on the object 275 * containing the page (O). 276 * 277 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG) 278 * indicates that the page is not under PV management but 279 * otherwise should be treated as a normal page. Pages not 280 * under PV management cannot be paged out via the 281 * object/vm_page_t because there is no knowledge of their pte 282 * mappings, and such pages are also not on any PQ queue. 283 * 284 */ 285 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */ 286 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */ 287 #define VPO_UNMANAGED 0x04 /* no PV management for page */ 288 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */ 289 290 /* 291 * Busy page implementation details. 292 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation, 293 * even if the support for owner identity is removed because of size 294 * constraints. Checks on lock recursion are then not possible, while the 295 * lock assertions effectiveness is someway reduced. 296 */ 297 #define VPB_BIT_SHARED 0x01 298 #define VPB_BIT_EXCLUSIVE 0x02 299 #define VPB_BIT_WAITERS 0x04 300 #define VPB_BIT_FLAGMASK \ 301 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS) 302 303 #define VPB_SHARERS_SHIFT 3 304 #define VPB_SHARERS(x) \ 305 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT) 306 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED) 307 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT) 308 309 #define VPB_SINGLE_EXCLUSIVE VPB_BIT_EXCLUSIVE 310 #ifdef INVARIANTS 311 #define VPB_CURTHREAD_EXCLUSIVE \ 312 (VPB_BIT_EXCLUSIVE | ((u_int)(uintptr_t)curthread & ~VPB_BIT_FLAGMASK)) 313 #else 314 #define VPB_CURTHREAD_EXCLUSIVE VPB_SINGLE_EXCLUSIVE 315 #endif 316 317 #define VPB_UNBUSIED VPB_SHARERS_WORD(0) 318 319 /* Freed lock blocks both shared and exclusive. */ 320 #define VPB_FREED (0xffffffff - VPB_BIT_SHARED) 321 322 #define PQ_NONE 255 323 #define PQ_INACTIVE 0 324 #define PQ_ACTIVE 1 325 #define PQ_LAUNDRY 2 326 #define PQ_UNSWAPPABLE 3 327 #define PQ_COUNT 4 328 329 #ifndef VM_PAGE_HAVE_PGLIST 330 TAILQ_HEAD(pglist, vm_page); 331 #define VM_PAGE_HAVE_PGLIST 332 #endif 333 SLIST_HEAD(spglist, vm_page); 334 335 #ifdef _KERNEL 336 extern vm_page_t bogus_page; 337 #endif /* _KERNEL */ 338 339 /* 340 * The vm_page's aflags are updated using atomic operations. To set or clear 341 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear() 342 * must be used. Neither these flags nor these functions are part of the KBI. 343 * 344 * PGA_REFERENCED may be cleared only if the page is locked. It is set by 345 * both the MI and MD VM layers. However, kernel loadable modules should not 346 * directly set this flag. They should call vm_page_reference() instead. 347 * 348 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). 349 * When it does so, the object must be locked, or the page must be 350 * exclusive busied. The MI VM layer must never access this flag 351 * directly. Instead, it should call pmap_page_is_write_mapped(). 352 * 353 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has 354 * at least one executable mapping. It is not consumed by the MI VM layer. 355 * 356 * PGA_NOSYNC must be set and cleared with the page busy lock held. 357 * 358 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed 359 * from a page queue, respectively. It determines whether the plinks.q field 360 * of the page is valid. To set or clear this flag, page's "queue" field must 361 * be a valid queue index, and the corresponding page queue lock must be held. 362 * 363 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page 364 * queue, and cleared when the dequeue request is processed. A page may 365 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue 366 * is requested after the page is scheduled to be enqueued but before it is 367 * actually inserted into the page queue. 368 * 369 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued 370 * in its page queue. 371 * 372 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of 373 * the inactive queue, thus bypassing LRU. 374 * 375 * The PGA_DEQUEUE, PGA_REQUEUE and PGA_REQUEUE_HEAD flags must be set using an 376 * atomic RMW operation to ensure that the "queue" field is a valid queue index, 377 * and the corresponding page queue lock must be held when clearing any of the 378 * flags. 379 * 380 * PGA_SWAP_FREE is used to defer freeing swap space to the pageout daemon 381 * when the context that dirties the page does not have the object write lock 382 * held. 383 */ 384 #define PGA_WRITEABLE 0x0001 /* page may be mapped writeable */ 385 #define PGA_REFERENCED 0x0002 /* page has been referenced */ 386 #define PGA_EXECUTABLE 0x0004 /* page may be mapped executable */ 387 #define PGA_ENQUEUED 0x0008 /* page is enqueued in a page queue */ 388 #define PGA_DEQUEUE 0x0010 /* page is due to be dequeued */ 389 #define PGA_REQUEUE 0x0020 /* page is due to be requeued */ 390 #define PGA_REQUEUE_HEAD 0x0040 /* page requeue should bypass LRU */ 391 #define PGA_NOSYNC 0x0080 /* do not collect for syncer */ 392 #define PGA_SWAP_FREE 0x0100 /* page with swap space was dirtied */ 393 #define PGA_SWAP_SPACE 0x0200 /* page has allocated swap space */ 394 395 #define PGA_QUEUE_OP_MASK (PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD) 396 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_QUEUE_OP_MASK) 397 398 /* 399 * Page flags. Updates to these flags are not synchronized, and thus they must 400 * be set during page allocation or free to avoid races. 401 * 402 * The PG_PCPU_CACHE flag is set at allocation time if the page was 403 * allocated from a per-CPU cache. It is cleared the next time that the 404 * page is allocated from the physical memory allocator. 405 */ 406 #define PG_PCPU_CACHE 0x01 /* was allocated from per-CPU caches */ 407 #define PG_FICTITIOUS 0x02 /* physical page doesn't exist */ 408 #define PG_ZERO 0x04 /* page is zeroed */ 409 #define PG_MARKER 0x08 /* special queue marker page */ 410 #define PG_NODUMP 0x10 /* don't include this page in a dump */ 411 #define PG_NOFREE 0x20 /* page should never be freed. */ 412 413 /* 414 * Misc constants. 415 */ 416 #define ACT_DECLINE 1 417 #define ACT_ADVANCE 3 418 #define ACT_INIT 5 419 #define ACT_MAX 64 420 421 #ifdef _KERNEL 422 423 #include <sys/kassert.h> 424 #include <machine/atomic.h> 425 struct pctrie_iter; 426 427 /* 428 * Each pageable resident page falls into one of five lists: 429 * 430 * free 431 * Available for allocation now. 432 * 433 * inactive 434 * Low activity, candidates for reclamation. 435 * This list is approximately LRU ordered. 436 * 437 * laundry 438 * This is the list of pages that should be 439 * paged out next. 440 * 441 * unswappable 442 * Dirty anonymous pages that cannot be paged 443 * out because no swap device is configured. 444 * 445 * active 446 * Pages that are "active", i.e., they have been 447 * recently referenced. 448 * 449 */ 450 451 extern vm_page_t vm_page_array; /* First resident page in table */ 452 extern long vm_page_array_size; /* number of vm_page_t's */ 453 extern long first_page; /* first physical page number */ 454 455 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr) 456 457 /* 458 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory 459 * page to which the given physical address belongs. The correct vm_page_t 460 * object is returned for addresses that are not page-aligned. 461 */ 462 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa); 463 464 /* 465 * vm_page allocation arguments for the functions vm_page_alloc(), 466 * vm_page_alloc_contig(), vm_page_alloc_noobj(), vm_page_grab(), and 467 * vm_page_grab_pages(). Each function supports only a subset of the flags. 468 * See the flags legend. 469 * 470 * The meaning of VM_ALLOC_ZERO varies: vm_page_alloc_noobj(), vm_page_grab(), 471 * and vm_page_grab_pages() guarantee that the returned pages are zeroed; in 472 * contrast vm_page_alloc() and vm_page_alloc_contig() do not, leaving it to 473 * the caller to test the page's flags for PG_ZERO. 474 * 475 * Bits 0 - 1 define class. 476 * Bits 2 - 15 dedicated for flags. 477 * Legend: 478 * (a) - vm_page_alloc() supports the flag. 479 * (c) - vm_page_alloc_contig() supports the flag. 480 * (g) - vm_page_grab() supports the flag. 481 * (n) - vm_page_alloc_noobj() supports the flag. 482 * (p) - vm_page_grab_pages() supports the flag. 483 * Bits above 15 define the count of additional pages that the caller 484 * intends to allocate. 485 */ 486 #define VM_ALLOC_NORMAL 0 487 #define VM_ALLOC_INTERRUPT 1 488 #define VM_ALLOC_SYSTEM 2 489 #define VM_ALLOC_CLASS_MASK 3 490 #define VM_ALLOC_WAITOK 0x0008 /* (gnp) Sleep and retry */ 491 #define VM_ALLOC_WAITFAIL 0x0010 /* (acgnp) Sleep and return error */ 492 #define VM_ALLOC_WIRED 0x0020 /* (acgnp) Allocate a wired page */ 493 #define VM_ALLOC_ZERO 0x0040 /* (acgnp) Allocate a zeroed page */ 494 #define VM_ALLOC_NORECLAIM 0x0080 /* (c) Do not reclaim after failure */ 495 #define VM_ALLOC_NOFREE 0x0100 /* (agnp) Page will never be freed */ 496 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */ 497 #define VM_ALLOC_NOCREAT 0x0400 /* (gp) Do not allocate a page */ 498 #define VM_ALLOC_AVAIL1 0x0800 499 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy state */ 500 #define VM_ALLOC_NODUMP 0x2000 /* (acgnp) Do not include in dump */ 501 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */ 502 #define VM_ALLOC_NOWAIT 0x8000 /* (acgnp) Do not sleep */ 503 #define VM_ALLOC_COUNT_MAX 0xffff 504 #define VM_ALLOC_COUNT_SHIFT 16 505 #define VM_ALLOC_COUNT_MASK (VM_ALLOC_COUNT(VM_ALLOC_COUNT_MAX)) 506 #define VM_ALLOC_COUNT(count) ({ /* (acgn) Additional pages */ \ 507 KASSERT((count) <= VM_ALLOC_COUNT_MAX, \ 508 ("%s: invalid VM_ALLOC_COUNT value", __func__)); \ 509 (count) << VM_ALLOC_COUNT_SHIFT; \ 510 }) 511 512 #ifdef M_NOWAIT 513 static inline int 514 malloc2vm_flags(int malloc_flags) 515 { 516 int pflags; 517 518 KASSERT((malloc_flags & M_USE_RESERVE) == 0 || 519 (malloc_flags & M_NOWAIT) != 0, 520 ("M_USE_RESERVE requires M_NOWAIT")); 521 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT : 522 VM_ALLOC_SYSTEM; 523 if ((malloc_flags & M_ZERO) != 0) 524 pflags |= VM_ALLOC_ZERO; 525 if ((malloc_flags & M_NODUMP) != 0) 526 pflags |= VM_ALLOC_NODUMP; 527 if ((malloc_flags & M_NOWAIT)) 528 pflags |= VM_ALLOC_NOWAIT; 529 if ((malloc_flags & M_WAITOK)) 530 pflags |= VM_ALLOC_WAITOK; 531 if ((malloc_flags & M_NORECLAIM)) 532 pflags |= VM_ALLOC_NORECLAIM; 533 if ((malloc_flags & M_NEVERFREED)) 534 pflags |= VM_ALLOC_NOFREE; 535 return (pflags); 536 } 537 #endif 538 539 /* 540 * Predicates supported by vm_page_ps_test(): 541 * 542 * PS_ALL_DIRTY is true only if the entire (super)page is dirty. 543 * However, it can be spuriously false when the (super)page has become 544 * dirty in the pmap but that information has not been propagated to the 545 * machine-independent layer. 546 */ 547 #define PS_ALL_DIRTY 0x1 548 #define PS_ALL_VALID 0x2 549 #define PS_NONE_BUSY 0x4 550 551 void vm_page_activate (vm_page_t); 552 void vm_page_advise(vm_page_t m, int advice); 553 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int); 554 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, 555 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, 556 vm_paddr_t boundary, vm_memattr_t memattr); 557 vm_page_t vm_page_alloc_contig_domain(vm_object_t object, 558 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low, 559 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 560 vm_memattr_t memattr); 561 vm_page_t vm_page_alloc_domain_iter(vm_object_t object, vm_pindex_t pindex, 562 int domain, int req, struct pctrie_iter *pages); 563 vm_page_t vm_page_alloc_iter(vm_object_t object, vm_pindex_t pindex, int req, 564 struct pctrie_iter *pages); 565 vm_page_t vm_page_alloc_noobj(int); 566 vm_page_t vm_page_alloc_noobj_domain(int, int); 567 vm_page_t vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low, 568 vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 569 vm_memattr_t memattr); 570 vm_page_t vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages, 571 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 572 vm_memattr_t memattr); 573 void vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set); 574 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose); 575 bool vm_page_busy_acquire(vm_page_t m, int allocflags); 576 void vm_page_busy_downgrade(vm_page_t m); 577 int vm_page_busy_tryupgrade(vm_page_t m); 578 bool vm_page_busy_sleep(vm_page_t m, const char *msg, int allocflags); 579 void vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m, 580 vm_pindex_t pindex, const char *wmesg, int allocflags); 581 void vm_page_deactivate(vm_page_t m); 582 void vm_page_deactivate_noreuse(vm_page_t m); 583 void vm_page_dequeue(vm_page_t m); 584 void vm_page_dequeue_deferred(vm_page_t m); 585 void vm_page_free(vm_page_t m); 586 void vm_page_free_invalid(vm_page_t m); 587 int vm_page_free_pages_toq(struct spglist *free, bool update_wire_count); 588 void vm_page_free_zero(vm_page_t m); 589 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr); 590 int vm_page_grab_zero_partial(vm_object_t object, vm_pindex_t pindex, int base, 591 int end); 592 vm_page_t vm_page_grab(vm_object_t, vm_pindex_t, int); 593 vm_page_t vm_page_grab_iter(vm_object_t object, vm_pindex_t pindex, 594 int allocflags, struct pctrie_iter *pages); 595 vm_page_t vm_page_grab_unlocked(vm_object_t, vm_pindex_t, int); 596 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, 597 vm_page_t *ma, int count); 598 int vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex, 599 int allocflags, vm_page_t *ma, int count); 600 int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, 601 int allocflags); 602 int vm_page_grab_valid_iter(vm_page_t *mp, vm_object_t object, 603 vm_pindex_t pindex, int allocflags, struct pctrie_iter *pages); 604 int vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object, 605 vm_pindex_t pindex, int allocflags); 606 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 607 void vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags); 608 void vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind, int pool); 609 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t); 610 void vm_page_invalid(vm_page_t m); 611 void vm_page_iter_free(struct pctrie_iter *pages, vm_page_t m); 612 void vm_page_iter_init(struct pctrie_iter *, vm_object_t); 613 int vm_page_iter_insert(vm_page_t m, vm_object_t, vm_pindex_t, 614 struct pctrie_iter *); 615 void vm_page_iter_limit_init(struct pctrie_iter *, vm_object_t, vm_pindex_t); 616 bool vm_page_iter_remove(struct pctrie_iter *pages, vm_page_t m); 617 bool vm_page_iter_rename(struct pctrie_iter *old_pages, vm_page_t m, 618 vm_object_t new_object, vm_pindex_t new_pindex); 619 void vm_page_launder(vm_page_t m); 620 vm_page_t vm_page_lookup(vm_object_t, vm_pindex_t); 621 vm_page_t vm_page_lookup_unlocked(vm_object_t, vm_pindex_t); 622 void vm_page_pqbatch_drain(void); 623 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue); 624 bool vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old, 625 vm_page_astate_t new); 626 bool vm_page_ps_test(vm_page_t m, int psind, int flags, vm_page_t skip_m); 627 void vm_page_putfake(vm_page_t m); 628 void vm_page_readahead_finish(vm_page_t m); 629 int vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, 630 vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 631 int vm_page_reclaim_contig_domain(int domain, int req, u_long npages, 632 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary); 633 int vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages, 634 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, 635 int desired_runs); 636 void vm_page_reference(vm_page_t m); 637 #define VPR_TRYFREE 0x01 638 #define VPR_NOREUSE 0x02 639 void vm_page_release(vm_page_t m, int flags); 640 void vm_page_release_locked(vm_page_t m, int flags); 641 vm_page_t vm_page_relookup(vm_object_t, vm_pindex_t); 642 bool vm_page_remove(vm_page_t); 643 bool vm_page_remove_xbusy(vm_page_t); 644 void vm_page_replace(vm_page_t mnew, vm_object_t object, 645 vm_pindex_t pindex, vm_page_t mold); 646 int vm_page_sbusied(vm_page_t m); 647 vm_page_bits_t vm_page_set_dirty(vm_page_t m); 648 void vm_page_set_valid_range(vm_page_t m, int base, int size); 649 vm_offset_t vm_page_startup(vm_offset_t vaddr); 650 void vm_page_sunbusy(vm_page_t m); 651 bool vm_page_try_remove_all(vm_page_t m); 652 bool vm_page_try_remove_write(vm_page_t m); 653 int vm_page_trysbusy(vm_page_t m); 654 int vm_page_tryxbusy(vm_page_t m); 655 void vm_page_unhold_pages(vm_page_t *ma, int count); 656 void vm_page_unswappable(vm_page_t m); 657 void vm_page_unwire(vm_page_t m, uint8_t queue); 658 bool vm_page_unwire_noq(vm_page_t m); 659 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); 660 void vm_page_wire(vm_page_t); 661 bool vm_page_wire_mapped(vm_page_t m); 662 void vm_page_xunbusy_hard(vm_page_t m); 663 void vm_page_xunbusy_hard_unchecked(vm_page_t m); 664 void vm_page_set_validclean (vm_page_t, int, int); 665 void vm_page_clear_dirty(vm_page_t, int, int); 666 void vm_page_set_invalid(vm_page_t, int, int); 667 void vm_page_valid(vm_page_t m); 668 int vm_page_is_valid(vm_page_t, int, int); 669 void vm_page_test_dirty(vm_page_t); 670 vm_page_bits_t vm_page_bits(int base, int size); 671 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); 672 673 void vm_page_dirty_KBI(vm_page_t m); 674 675 #define vm_page_busy_fetch(m) atomic_load_int(&(m)->busy_lock) 676 677 #define vm_page_assert_busied(m) \ 678 KASSERT(vm_page_busied(m), \ 679 ("vm_page_assert_busied: page %p not busy @ %s:%d", \ 680 (m), __FILE__, __LINE__)) 681 682 #define vm_page_assert_sbusied(m) \ 683 KASSERT(vm_page_sbusied(m), \ 684 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \ 685 (m), __FILE__, __LINE__)) 686 687 #define vm_page_assert_unbusied(m) \ 688 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) != \ 689 VPB_CURTHREAD_EXCLUSIVE, \ 690 ("vm_page_assert_unbusied: page %p busy_lock %#x owned" \ 691 " by me (%p) @ %s:%d", \ 692 (m), (m)->busy_lock, curthread, __FILE__, __LINE__)); \ 693 694 #define vm_page_assert_xbusied_unchecked(m) do { \ 695 KASSERT(vm_page_xbusied(m), \ 696 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \ 697 (m), __FILE__, __LINE__)); \ 698 } while (0) 699 #define vm_page_assert_xbusied(m) do { \ 700 vm_page_assert_xbusied_unchecked(m); \ 701 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) == \ 702 VPB_CURTHREAD_EXCLUSIVE, \ 703 ("vm_page_assert_xbusied: page %p busy_lock %#x not owned" \ 704 " by me (%p) @ %s:%d", \ 705 (m), (m)->busy_lock, curthread, __FILE__, __LINE__)); \ 706 } while (0) 707 708 #define vm_page_busied(m) \ 709 (vm_page_busy_fetch(m) != VPB_UNBUSIED) 710 711 #define vm_page_xbusied(m) \ 712 ((vm_page_busy_fetch(m) & VPB_SINGLE_EXCLUSIVE) != 0) 713 714 #define vm_page_busy_freed(m) \ 715 (vm_page_busy_fetch(m) == VPB_FREED) 716 717 /* Note: page m's lock must not be owned by the caller. */ 718 #define vm_page_xunbusy(m) do { \ 719 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 720 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 721 vm_page_xunbusy_hard(m); \ 722 } while (0) 723 #define vm_page_xunbusy_unchecked(m) do { \ 724 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \ 725 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \ 726 vm_page_xunbusy_hard_unchecked(m); \ 727 } while (0) 728 729 #ifdef INVARIANTS 730 void vm_page_object_busy_assert(vm_page_t m); 731 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) vm_page_object_busy_assert(m) 732 void vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits); 733 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \ 734 vm_page_assert_pga_writeable(m, bits) 735 /* 736 * Claim ownership of a page's xbusy state. In non-INVARIANTS kernels this 737 * operation is a no-op since ownership is not tracked. In particular 738 * this macro does not provide any synchronization with the previous owner. 739 */ 740 #define vm_page_xbusy_claim(m) do { \ 741 u_int _busy_lock; \ 742 \ 743 vm_page_assert_xbusied_unchecked((m)); \ 744 do { \ 745 _busy_lock = vm_page_busy_fetch(m); \ 746 } while (!atomic_cmpset_int(&(m)->busy_lock, _busy_lock, \ 747 (_busy_lock & VPB_BIT_FLAGMASK) | VPB_CURTHREAD_EXCLUSIVE)); \ 748 } while (0) 749 #else 750 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) (void)0 751 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0 752 #define vm_page_xbusy_claim(m) 753 #endif 754 755 #if BYTE_ORDER == BIG_ENDIAN 756 #define VM_PAGE_AFLAG_SHIFT 16 757 #else 758 #define VM_PAGE_AFLAG_SHIFT 0 759 #endif 760 761 /* 762 * Load a snapshot of a page's 32-bit atomic state. 763 */ 764 static inline vm_page_astate_t 765 vm_page_astate_load(vm_page_t m) 766 { 767 vm_page_astate_t a; 768 769 a._bits = atomic_load_32(&m->a._bits); 770 return (a); 771 } 772 773 /* 774 * Atomically compare and set a page's atomic state. 775 */ 776 static inline bool 777 vm_page_astate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new) 778 { 779 780 KASSERT(new.queue == PQ_INACTIVE || (new.flags & PGA_REQUEUE_HEAD) == 0, 781 ("%s: invalid head requeue request for page %p", __func__, m)); 782 KASSERT((new.flags & PGA_ENQUEUED) == 0 || new.queue != PQ_NONE, 783 ("%s: setting PGA_ENQUEUED with PQ_NONE in page %p", __func__, m)); 784 KASSERT(new._bits != old->_bits, 785 ("%s: bits are unchanged", __func__)); 786 787 return (atomic_fcmpset_32(&m->a._bits, &old->_bits, new._bits) != 0); 788 } 789 790 /* 791 * Clear the given bits in the specified page. 792 */ 793 static inline void 794 vm_page_aflag_clear(vm_page_t m, uint16_t bits) 795 { 796 uint32_t *addr, val; 797 798 /* 799 * Access the whole 32-bit word containing the aflags field with an 800 * atomic update. Parallel non-atomic updates to the other fields 801 * within this word are handled properly by the atomic update. 802 */ 803 addr = (void *)&m->a; 804 val = bits << VM_PAGE_AFLAG_SHIFT; 805 atomic_clear_32(addr, val); 806 } 807 808 /* 809 * Set the given bits in the specified page. 810 */ 811 static inline void 812 vm_page_aflag_set(vm_page_t m, uint16_t bits) 813 { 814 uint32_t *addr, val; 815 816 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits); 817 818 /* 819 * Access the whole 32-bit word containing the aflags field with an 820 * atomic update. Parallel non-atomic updates to the other fields 821 * within this word are handled properly by the atomic update. 822 */ 823 addr = (void *)&m->a; 824 val = bits << VM_PAGE_AFLAG_SHIFT; 825 atomic_set_32(addr, val); 826 } 827 828 /* 829 * vm_page_dirty: 830 * 831 * Set all bits in the page's dirty field. 832 * 833 * The object containing the specified page must be locked if the 834 * call is made from the machine-independent layer. 835 * 836 * See vm_page_clear_dirty_mask(). 837 */ 838 static __inline void 839 vm_page_dirty(vm_page_t m) 840 { 841 842 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */ 843 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS) 844 vm_page_dirty_KBI(m); 845 #else 846 m->dirty = VM_PAGE_BITS_ALL; 847 #endif 848 } 849 850 /* 851 * vm_page_undirty: 852 * 853 * Set page to not be dirty. Note: does not clear pmap modify bits 854 */ 855 static __inline void 856 vm_page_undirty(vm_page_t m) 857 { 858 859 VM_PAGE_OBJECT_BUSY_ASSERT(m); 860 m->dirty = 0; 861 } 862 863 static inline uint8_t 864 _vm_page_queue(vm_page_astate_t as) 865 { 866 867 if ((as.flags & PGA_DEQUEUE) != 0) 868 return (PQ_NONE); 869 return (as.queue); 870 } 871 872 /* 873 * vm_page_queue: 874 * 875 * Return the index of the queue containing m. 876 */ 877 static inline uint8_t 878 vm_page_queue(vm_page_t m) 879 { 880 881 return (_vm_page_queue(vm_page_astate_load(m))); 882 } 883 884 static inline bool 885 vm_page_active(vm_page_t m) 886 { 887 888 return (vm_page_queue(m) == PQ_ACTIVE); 889 } 890 891 static inline bool 892 vm_page_inactive(vm_page_t m) 893 { 894 895 return (vm_page_queue(m) == PQ_INACTIVE); 896 } 897 898 static inline bool 899 vm_page_in_laundry(vm_page_t m) 900 { 901 uint8_t queue; 902 903 queue = vm_page_queue(m); 904 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE); 905 } 906 907 static inline void 908 vm_page_clearref(vm_page_t m) 909 { 910 u_int r; 911 912 r = m->ref_count; 913 while (atomic_fcmpset_int(&m->ref_count, &r, r & (VPRC_BLOCKED | 914 VPRC_OBJREF)) == 0) 915 ; 916 } 917 918 /* 919 * vm_page_drop: 920 * 921 * Release a reference to a page and return the old reference count. 922 */ 923 static inline u_int 924 vm_page_drop(vm_page_t m, u_int val) 925 { 926 u_int old; 927 928 /* 929 * Synchronize with vm_page_free_prep(): ensure that all updates to the 930 * page structure are visible before it is freed. 931 */ 932 atomic_thread_fence_rel(); 933 old = atomic_fetchadd_int(&m->ref_count, -val); 934 KASSERT(old != VPRC_BLOCKED, 935 ("vm_page_drop: page %p has an invalid refcount value", m)); 936 return (old); 937 } 938 939 /* 940 * vm_page_wired: 941 * 942 * Perform a racy check to determine whether a reference prevents the page 943 * from being reclaimable. If the page's object is locked, and the page is 944 * unmapped and exclusively busied by the current thread, no new wirings 945 * may be created. 946 */ 947 static inline bool 948 vm_page_wired(vm_page_t m) 949 { 950 951 return (VPRC_WIRE_COUNT(m->ref_count) > 0); 952 } 953 954 static inline bool 955 vm_page_all_valid(vm_page_t m) 956 { 957 958 return (m->valid == VM_PAGE_BITS_ALL); 959 } 960 961 static inline bool 962 vm_page_any_valid(vm_page_t m) 963 { 964 965 return (m->valid != 0); 966 } 967 968 static inline bool 969 vm_page_none_valid(vm_page_t m) 970 { 971 972 return (m->valid == 0); 973 } 974 975 static inline int 976 vm_page_domain(vm_page_t m __numa_used) 977 { 978 #ifdef NUMA 979 int domn, segind; 980 981 segind = m->segind; 982 KASSERT(segind < vm_phys_nsegs, ("segind %d m %p", segind, m)); 983 domn = vm_phys_segs[segind].domain; 984 KASSERT(domn >= 0 && domn < vm_ndomains, ("domain %d m %p", domn, m)); 985 return (domn); 986 #else 987 return (0); 988 #endif 989 } 990 991 #endif /* _KERNEL */ 992 #endif /* !_VM_PAGE_ */ 993