2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
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11 * modification, are permitted provided that the following conditions
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
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19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
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
34 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
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.
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.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
66 * Resident memory system definitions.
75 * Management of resident (logical) pages.
77 * A small structure is kept for each resident
78 * page, indexed by page number. Each structure
79 * is an element of several collections:
81 * A radix tree used to quickly
82 * perform object/offset lookups
84 * A list of all pages for a given object,
85 * so they can be quickly deactivated at
86 * time of deallocation.
88 * An ordered list of pages due for pageout.
90 * In addition, the structure contains the object
91 * and offset to which this page belongs (for pageout),
92 * and sundry status bits.
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 * An annotation of (A) indicates that modifications to the field must
105 * be atomic. Accesses to such fields may require additional
106 * synchronization depending on the context.
108 * In contrast, the synchronization of accesses to the page's
109 * dirty field is machine dependent (M). In the
110 * machine-independent layer, the lock on the object that the
111 * page belongs to must be held in order to operate on the field.
112 * However, the pmap layer is permitted to set all bits within
113 * the field without holding that lock. If the underlying
114 * architecture does not support atomic read-modify-write
115 * operations on the field's type, then the machine-independent
116 * layer uses a 32-bit atomic on the aligned 32-bit word that
117 * contains the dirty field. In the machine-independent layer,
118 * the implementation of read-modify-write operations on the
119 * field is encapsulated in vm_page_clear_dirty_mask().
121 * The ref_count field tracks references to the page. References that
122 * prevent the page from being reclaimable are called wirings and are
123 * counted in the low bits of ref_count. The containing object's
124 * reference, if one exists, is counted using the VPRC_OBJREF bit in the
125 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to
126 * atomically check for wirings and prevent new wirings via
127 * pmap_extract_and_hold(). When a page belongs to an object, it may be
128 * wired only when the object is locked, or the page is busy, or by
129 * pmap_extract_and_hold(). As a result, if the object is locked and the
130 * page is not busy (or is exclusively busied by the current thread), and
131 * the page is unmapped, its wire count will not increase. The ref_count
132 * field is updated using atomic operations in most cases, except when it
133 * is known that no other references to the page exist, such as in the page
134 * allocator. A page may be present in the page queues, or even actively
135 * scanned by the page daemon, without an explicitly counted referenced.
136 * The page daemon must therefore handle the possibility of a concurrent
139 * The busy lock is an embedded reader-writer lock which protects the
140 * page's contents and identity (i.e., its <object, pindex> tuple) and
141 * interlocks with the object lock (O). In particular, a page may be
142 * busied or unbusied only with the object write lock held. To avoid
143 * bloating the page structure, the busy lock lacks some of the
144 * features available to the kernel's general-purpose synchronization
145 * primitives. As a result, busy lock ordering rules are not verified,
146 * lock recursion is not detected, and an attempt to xbusy a busy page
147 * or sbusy an xbusy page results will trigger a panic rather than
148 * causing the thread to block. vm_page_sleep_if_busy() can be used to
149 * sleep until the page's busy state changes, after which the caller
150 * must re-lookup the page and re-evaluate its state.
152 * The queue field is the index of the page queue containing the page,
153 * or PQ_NONE if the page is not enqueued. The queue lock of a page is
154 * the page queue lock corresponding to the page queue index, or the
155 * page lock (P) for the page if it is not enqueued. To modify the
156 * queue field, the queue lock for the old value of the field must be
157 * held. There is one exception to this rule: the page daemon may
158 * transition the queue field from PQ_INACTIVE to PQ_NONE immediately
159 * prior to freeing a page during an inactive queue scan. At that
160 * point the page has already been physically dequeued and no other
161 * references to that vm_page structure exist.
163 * To avoid contention on page queue locks, page queue operations
164 * (enqueue, dequeue, requeue) are batched using per-CPU queues. A
165 * deferred operation is requested by inserting an entry into a batch
166 * queue; the entry is simply a pointer to the page, and the request
167 * type is encoded in the page's aflags field using the values in
168 * PGA_QUEUE_STATE_MASK. The type-stability of struct vm_pages is
169 * crucial to this scheme since the processing of entries in a given
170 * batch queue may be deferred indefinitely. In particular, a page may
171 * be freed before its pending batch queue entries have been processed.
172 * The page lock (P) must be held to schedule a batched queue
173 * operation, and the page queue lock must be held in order to process
174 * batch queue entries for the page queue. There is one exception to
175 * this rule: the thread freeing a page may schedule a dequeue without
176 * holding the page lock. In this scenario the only other thread which
177 * may hold a reference to the page is the page daemon, which is
178 * careful to avoid modifying the page's queue state once the dequeue
179 * has been requested by setting PGA_DEQUEUE.
182 #if PAGE_SIZE == 4096
183 #define VM_PAGE_BITS_ALL 0xffu
184 typedef uint8_t vm_page_bits_t;
185 #elif PAGE_SIZE == 8192
186 #define VM_PAGE_BITS_ALL 0xffffu
187 typedef uint16_t vm_page_bits_t;
188 #elif PAGE_SIZE == 16384
189 #define VM_PAGE_BITS_ALL 0xffffffffu
190 typedef uint32_t vm_page_bits_t;
191 #elif PAGE_SIZE == 32768
192 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
193 typedef uint64_t vm_page_bits_t;
198 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */
200 SLIST_ENTRY(vm_page) ss; /* private slists */
208 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
209 vm_object_t object; /* which object am I in (O) */
210 vm_pindex_t pindex; /* offset into object (O,P) */
211 vm_paddr_t phys_addr; /* physical address of page (C) */
212 struct md_page md; /* machine dependent stuff */
213 u_int ref_count; /* page references (A) */
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) */
231 * Special bits used in the ref_count field.
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.
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.
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.
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))
251 * Page flags stored in oflags:
253 * Access to these page flags is synchronized by the lock on the object
254 * containing the page (O).
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.
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 */
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.
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)
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)
289 #define VPB_SINGLE_EXCLUSIVER VPB_BIT_EXCLUSIVE
291 #define VPB_UNBUSIED VPB_SHARERS_WORD(0)
294 #define PQ_INACTIVE 0
297 #define PQ_UNSWAPPABLE 3
300 #ifndef VM_PAGE_HAVE_PGLIST
301 TAILQ_HEAD(pglist, vm_page);
302 #define VM_PAGE_HAVE_PGLIST
304 SLIST_HEAD(spglist, vm_page);
307 extern vm_page_t bogus_page;
310 extern struct mtx_padalign pa_lock[];
313 #define PDRSHIFT PDR_SHIFT
314 #elif !defined(PDRSHIFT)
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) \
332 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
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)))
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__)
350 #define vm_page_assert_locked(m)
351 #define vm_page_lock_assert(m, a)
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.
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.
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().
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.
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.
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
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.
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.
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 */
402 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_DEQUEUE | PGA_REQUEUE | \
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.
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.
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 */
422 #define ACT_DECLINE 1
423 #define ACT_ADVANCE 3
429 #include <sys/systm.h>
431 #include <machine/atomic.h>
434 * Each pageable resident page falls into one of five lists:
437 * Available for allocation now.
440 * Low activity, candidates for reclamation.
441 * This list is approximately LRU ordered.
444 * This is the list of pages that should be
448 * Dirty anonymous pages that cannot be paged
449 * out because no swap device is configured.
452 * Pages that are "active", i.e., they have been
453 * recently referenced.
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 */
461 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
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.
468 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
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.
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.
479 * Bits 0 - 1 define class.
480 * Bits 2 - 15 dedicated for flags.
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.
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)
510 malloc2vm_flags(int malloc_flags)
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 :
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;
532 * Predicates supported by vm_page_ps_test():
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.
539 #define PS_ALL_DIRTY 0x1
540 #define PS_ALL_VALID 0x2
541 #define PS_NONE_BUSY 0x4
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);
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,
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,
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,
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);
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);
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__))
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__))
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__))
659 #define vm_page_busied(m) \
660 ((m)->busy_lock != VPB_UNBUSIED)
662 #define vm_page_sbusy(m) do { \
663 if (!vm_page_trysbusy(m)) \
664 panic("%s: page %p failed shared busying", __func__, \
668 #define vm_page_tryxbusy(m) \
669 (atomic_cmpset_acq_int(&(m)->busy_lock, VPB_UNBUSIED, \
670 VPB_SINGLE_EXCLUSIVER))
672 #define vm_page_xbusied(m) \
673 (((m)->busy_lock & VPB_SINGLE_EXCLUSIVER) != 0)
675 #define vm_page_xbusy(m) do { \
676 if (!vm_page_tryxbusy(m)) \
677 panic("%s: page %p failed exclusive busying", __func__, \
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); \
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)
695 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0
696 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0
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.
705 _Static_assert(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0,
706 "aflags field is not 32-bit aligned");
709 * We want to be able to update the aflags and queue fields atomically in
710 * the same operation.
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");
720 #if BYTE_ORDER == LITTLE_ENDIAN
721 #define VM_PAGE_AFLAG_SHIFT 0
722 #define VM_PAGE_QUEUE_SHIFT 16
724 #define VM_PAGE_AFLAG_SHIFT 24
725 #define VM_PAGE_QUEUE_SHIFT 8
727 #define VM_PAGE_QUEUE_MASK (0xff << VM_PAGE_QUEUE_SHIFT)
730 * Clear the given bits in the specified page.
733 vm_page_aflag_clear(vm_page_t m, uint8_t bits)
738 * The PGA_REFERENCED flag can only be cleared if the page is locked.
740 if ((bits & PGA_REFERENCED) != 0)
741 vm_page_assert_locked(m);
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.
748 addr = (void *)&m->aflags;
749 val = bits << VM_PAGE_AFLAG_SHIFT;
750 atomic_clear_32(addr, val);
754 * Set the given bits in the specified page.
757 vm_page_aflag_set(vm_page_t m, uint8_t bits)
761 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits);
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.
768 addr = (void *)&m->aflags;
769 val = bits << VM_PAGE_AFLAG_SHIFT;
770 atomic_set_32(addr, val);
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
781 vm_page_pqstate_cmpset(vm_page_t m, uint32_t oldq, uint32_t newq,
782 uint32_t fflags, uint32_t nflags)
784 uint32_t *addr, nval, oval, qsmask;
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;
793 addr = (void *)&m->aflags;
794 oval = atomic_load_32(addr);
796 if ((oval & fflags) != 0)
798 if ((oval & VM_PAGE_QUEUE_MASK) != oldq)
800 nval = (oval & ~qsmask) | nflags | newq;
801 } while (!atomic_fcmpset_32(addr, &oval, nval));
809 * Set all bits in the page's dirty field.
811 * The object containing the specified page must be locked if the
812 * call is made from the machine-independent layer.
814 * See vm_page_clear_dirty_mask().
817 vm_page_dirty(vm_page_t m)
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);
824 m->dirty = VM_PAGE_BITS_ALL;
831 * Set page to not be dirty. Note: does not clear pmap modify bits
834 vm_page_undirty(vm_page_t m)
837 VM_PAGE_OBJECT_LOCK_ASSERT(m);
842 vm_page_replace_checked(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex,
847 mret = vm_page_replace(mnew, object, pindex);
848 KASSERT(mret == mold,
849 ("invalid page replacement, mold=%p, mret=%p", mold, mret));
851 /* Unused if !INVARIANTS. */
859 * Return the index of the queue containing m. This index is guaranteed
860 * not to change while the page lock is held.
862 static inline uint8_t
863 vm_page_queue(vm_page_t m)
866 vm_page_assert_locked(m);
868 if ((m->aflags & PGA_DEQUEUE) != 0)
870 atomic_thread_fence_acq();
875 vm_page_active(vm_page_t m)
878 return (vm_page_queue(m) == PQ_ACTIVE);
882 vm_page_inactive(vm_page_t m)
885 return (vm_page_queue(m) == PQ_INACTIVE);
889 vm_page_in_laundry(vm_page_t m)
893 queue = vm_page_queue(m);
894 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE);
900 * Release a reference to a page and return the old reference count.
903 vm_page_drop(vm_page_t m, u_int val)
908 * Synchronize with vm_page_free_prep(): ensure that all updates to the
909 * page structure are visible before it is freed.
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));
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.
927 vm_page_wired(vm_page_t m)
930 return (VPRC_WIRE_COUNT(m->ref_count) > 0);
934 #endif /* !_VM_PAGE_ */