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.
73 #include <vm/_vm_phys.h>
76 * Management of resident (logical) pages.
78 * A small structure is kept for each resident
79 * page, indexed by page number. Each structure
80 * is an element of several collections:
82 * A radix tree used to quickly
83 * perform object/offset lookups
85 * A list of all pages for a given object,
86 * so they can be quickly deactivated at
87 * time of deallocation.
89 * An ordered list of pages due for pageout.
91 * In addition, the structure contains the object
92 * and offset to which this page belongs (for pageout),
93 * and sundry status bits.
95 * In general, operations on this structure's mutable fields are
96 * synchronized using either one of or a combination of locks. If a
97 * field is annotated with two of these locks then holding either is
98 * sufficient for read access but both are required for write access.
99 * The queue lock for a page depends on the value of its queue field and is
100 * described in detail below.
102 * The following annotations are possible:
103 * (A) the field must be accessed using atomic(9) and may require
104 * additional synchronization.
105 * (B) the page busy lock.
106 * (C) the field is immutable.
107 * (F) the per-domain lock for the free queues.
108 * (M) Machine dependent, defined by pmap layer.
109 * (O) the object that the page belongs to.
110 * (Q) the page's queue lock.
112 * The busy lock is an embedded reader-writer lock that protects the
113 * page's contents and identity (i.e., its <object, pindex> tuple) as
114 * well as certain valid/dirty modifications. To avoid bloating the
115 * the page structure, the busy lock lacks some of the features available
116 * the kernel's general-purpose synchronization primitives. As a result,
117 * busy lock ordering rules are not verified, lock recursion is not
118 * detected, and an attempt to xbusy a busy page or sbusy an xbusy page
119 * results will trigger a panic rather than causing the thread to block.
120 * vm_page_sleep_if_busy() can be used to sleep until the page's busy
121 * state changes, after which the caller must re-lookup the page and
122 * re-evaluate its state. vm_page_busy_acquire() will block until
123 * the lock is acquired.
125 * The valid field is protected by the page busy lock (B) and object
126 * lock (O). Transitions from invalid to valid are generally done
127 * via I/O or zero filling and do not require the object lock.
128 * These must be protected with the busy lock to prevent page-in or
129 * creation races. Page invalidation generally happens as a result
130 * of truncate or msync. When invalidated, pages must not be present
131 * in pmap and must hold the object lock to prevent concurrent
132 * speculative read-only mappings that do not require busy. I/O
133 * routines may check for validity without a lock if they are prepared
134 * to handle invalidation races with higher level locks (vnode) or are
135 * unconcerned with races so long as they hold a reference to prevent
136 * recycling. When a valid bit is set while holding a shared busy
137 * lock (A) atomic operations are used to protect against concurrent
140 * In contrast, the synchronization of accesses to the page's
141 * dirty field is a mix of machine dependent (M) and busy (B). In
142 * the machine-independent layer, the page busy must be held to
143 * operate on the field. However, the pmap layer is permitted to
144 * set all bits within the field without holding that lock. If the
145 * underlying architecture does not support atomic read-modify-write
146 * operations on the field's type, then the machine-independent
147 * layer uses a 32-bit atomic on the aligned 32-bit word that
148 * contains the dirty field. In the machine-independent layer,
149 * the implementation of read-modify-write operations on the
150 * field is encapsulated in vm_page_clear_dirty_mask(). An
151 * exclusive busy lock combined with pmap_remove_{write/all}() is the
152 * only way to ensure a page can not become dirty. I/O generally
153 * removes the page from pmap to ensure exclusive access and atomic
156 * The ref_count field tracks references to the page. References that
157 * prevent the page from being reclaimable are called wirings and are
158 * counted in the low bits of ref_count. The containing object's
159 * reference, if one exists, is counted using the VPRC_OBJREF bit in the
160 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to
161 * atomically check for wirings and prevent new wirings via
162 * pmap_extract_and_hold(). When a page belongs to an object, it may be
163 * wired only when the object is locked, or the page is busy, or by
164 * pmap_extract_and_hold(). As a result, if the object is locked and the
165 * page is not busy (or is exclusively busied by the current thread), and
166 * the page is unmapped, its wire count will not increase. The ref_count
167 * field is updated using atomic operations in most cases, except when it
168 * is known that no other references to the page exist, such as in the page
169 * allocator. A page may be present in the page queues, or even actively
170 * scanned by the page daemon, without an explicitly counted referenced.
171 * The page daemon must therefore handle the possibility of a concurrent
174 * The queue state of a page consists of the queue and act_count fields of
175 * its atomically updated state, and the subset of atomic flags specified
176 * by PGA_QUEUE_STATE_MASK. The queue field contains the page's page queue
177 * index, or PQ_NONE if it does not belong to a page queue. To modify the
178 * queue field, the page queue lock corresponding to the old value must be
179 * held, unless that value is PQ_NONE, in which case the queue index must
180 * be updated using an atomic RMW operation. There is one exception to
181 * this rule: the page daemon may transition the queue field from
182 * PQ_INACTIVE to PQ_NONE immediately prior to freeing the page during an
183 * inactive queue scan. At that point the page is already dequeued and no
184 * other references to that vm_page structure can exist. The PGA_ENQUEUED
185 * flag, when set, indicates that the page structure is physically inserted
186 * into the queue corresponding to the page's queue index, and may only be
187 * set or cleared with the corresponding page queue lock held.
189 * To avoid contention on page queue locks, page queue operations (enqueue,
190 * dequeue, requeue) are batched using fixed-size per-CPU queues. A
191 * deferred operation is requested by setting one of the flags in
192 * PGA_QUEUE_OP_MASK and inserting an entry into a batch queue. When a
193 * queue is full, an attempt to insert a new entry will lock the page
194 * queues and trigger processing of the pending entries. The
195 * type-stability of vm_page structures is crucial to this scheme since the
196 * processing of entries in a given batch queue may be deferred
197 * indefinitely. In particular, a page may be freed with pending batch
198 * queue entries. The page queue operation flags must be set using atomic
202 #if PAGE_SIZE == 4096
203 #define VM_PAGE_BITS_ALL 0xffu
204 typedef uint8_t vm_page_bits_t;
205 #elif PAGE_SIZE == 8192
206 #define VM_PAGE_BITS_ALL 0xffffu
207 typedef uint16_t vm_page_bits_t;
208 #elif PAGE_SIZE == 16384
209 #define VM_PAGE_BITS_ALL 0xffffffffu
210 typedef uint32_t vm_page_bits_t;
211 #elif PAGE_SIZE == 32768
212 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
213 typedef uint64_t vm_page_bits_t;
216 typedef union vm_page_astate {
227 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */
229 SLIST_ENTRY(vm_page) ss; /* private slists */
240 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
241 vm_object_t object; /* which object am I in (O) */
242 vm_pindex_t pindex; /* offset into object (O,P) */
243 vm_paddr_t phys_addr; /* physical address of page (C) */
244 struct md_page md; /* machine dependent stuff */
245 u_int ref_count; /* page references (A) */
246 u_int busy_lock; /* busy owners lock (A) */
247 union vm_page_astate a; /* state accessed atomically (A) */
248 uint8_t order; /* index of the buddy queue (F) */
249 uint8_t pool; /* vm_phys freepool index (F) */
250 uint8_t flags; /* page PG_* flags (P) */
251 uint8_t oflags; /* page VPO_* flags (O) */
252 int8_t psind; /* pagesizes[] index (O) */
253 int8_t segind; /* vm_phys segment index (C) */
254 /* NOTE that these must support one bit per DEV_BSIZE in a page */
255 /* so, on normal X86 kernels, they must be at least 8 bits wide */
256 vm_page_bits_t valid; /* valid DEV_BSIZE chunk map (O,B) */
257 vm_page_bits_t dirty; /* dirty DEV_BSIZE chunk map (M,B) */
261 * Special bits used in the ref_count field.
263 * ref_count is normally used to count wirings that prevent the page from being
264 * reclaimed, but also supports several special types of references that do not
265 * prevent reclamation. Accesses to the ref_count field must be atomic unless
266 * the page is unallocated.
268 * VPRC_OBJREF is the reference held by the containing object. It can set or
269 * cleared only when the corresponding object's write lock is held.
271 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while
272 * attempting to tear down all mappings of a given page. The page busy lock and
273 * object write lock must both be held in order to set or clear this bit.
275 #define VPRC_BLOCKED 0x40000000u /* mappings are being removed */
276 #define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */
277 #define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF))
278 #define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF))
281 * Page flags stored in oflags:
283 * Access to these page flags is synchronized by the lock on the object
284 * containing the page (O).
286 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
287 * indicates that the page is not under PV management but
288 * otherwise should be treated as a normal page. Pages not
289 * under PV management cannot be paged out via the
290 * object/vm_page_t because there is no knowledge of their pte
291 * mappings, and such pages are also not on any PQ queue.
294 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */
295 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */
296 #define VPO_UNMANAGED 0x04 /* no PV management for page */
297 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */
300 * Busy page implementation details.
301 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation,
302 * even if the support for owner identity is removed because of size
303 * constraints. Checks on lock recursion are then not possible, while the
304 * lock assertions effectiveness is someway reduced.
306 #define VPB_BIT_SHARED 0x01
307 #define VPB_BIT_EXCLUSIVE 0x02
308 #define VPB_BIT_WAITERS 0x04
309 #define VPB_BIT_FLAGMASK \
310 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS)
312 #define VPB_SHARERS_SHIFT 3
313 #define VPB_SHARERS(x) \
314 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT)
315 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED)
316 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT)
318 #define VPB_SINGLE_EXCLUSIVE VPB_BIT_EXCLUSIVE
320 #define VPB_CURTHREAD_EXCLUSIVE \
321 (VPB_BIT_EXCLUSIVE | ((u_int)(uintptr_t)curthread & ~VPB_BIT_FLAGMASK))
323 #define VPB_CURTHREAD_EXCLUSIVE VPB_SINGLE_EXCLUSIVE
326 #define VPB_UNBUSIED VPB_SHARERS_WORD(0)
328 /* Freed lock blocks both shared and exclusive. */
329 #define VPB_FREED (0xffffffff - VPB_BIT_SHARED)
332 #define PQ_INACTIVE 0
335 #define PQ_UNSWAPPABLE 3
338 #ifndef VM_PAGE_HAVE_PGLIST
339 TAILQ_HEAD(pglist, vm_page);
340 #define VM_PAGE_HAVE_PGLIST
342 SLIST_HEAD(spglist, vm_page);
345 extern vm_page_t bogus_page;
348 extern struct mtx_padalign pa_lock[];
351 #define PDRSHIFT PDR_SHIFT
352 #elif !defined(PDRSHIFT)
356 #define pa_index(pa) ((pa) >> PDRSHIFT)
357 #define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT]))
358 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
359 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
360 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
361 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
362 #define PA_UNLOCK_COND(pa) \
370 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
372 #if defined(KLD_MODULE) && !defined(KLD_TIED)
373 #define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
374 #define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
375 #define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
376 #else /* !KLD_MODULE */
377 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
378 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
379 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
380 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
382 #if defined(INVARIANTS)
383 #define vm_page_assert_locked(m) \
384 vm_page_assert_locked_KBI((m), __FILE__, __LINE__)
385 #define vm_page_lock_assert(m, a) \
386 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__)
388 #define vm_page_assert_locked(m)
389 #define vm_page_lock_assert(m, a)
393 * The vm_page's aflags are updated using atomic operations. To set or clear
394 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear()
395 * must be used. Neither these flags nor these functions are part of the KBI.
397 * PGA_REFERENCED may be cleared only if the page is locked. It is set by
398 * both the MI and MD VM layers. However, kernel loadable modules should not
399 * directly set this flag. They should call vm_page_reference() instead.
401 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter().
402 * When it does so, the object must be locked, or the page must be
403 * exclusive busied. The MI VM layer must never access this flag
404 * directly. Instead, it should call pmap_page_is_write_mapped().
406 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has
407 * at least one executable mapping. It is not consumed by the MI VM layer.
409 * PGA_NOSYNC must be set and cleared with the page busy lock held.
411 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed
412 * from a page queue, respectively. It determines whether the plinks.q field
413 * of the page is valid. To set or clear this flag, page's "queue" field must
414 * be a valid queue index, and the corresponding page queue lock must be held.
416 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page
417 * queue, and cleared when the dequeue request is processed. A page may
418 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue
419 * is requested after the page is scheduled to be enqueued but before it is
420 * actually inserted into the page queue.
422 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued
425 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of
426 * the inactive queue, thus bypassing LRU.
428 * The PGA_DEQUEUE, PGA_REQUEUE and PGA_REQUEUE_HEAD flags must be set using an
429 * atomic RMW operation to ensure that the "queue" field is a valid queue index,
430 * and the corresponding page queue lock must be held when clearing any of the
433 * PGA_SWAP_FREE is used to defer freeing swap space to the pageout daemon
434 * when the context that dirties the page does not have the object write lock
437 #define PGA_WRITEABLE 0x0001 /* page may be mapped writeable */
438 #define PGA_REFERENCED 0x0002 /* page has been referenced */
439 #define PGA_EXECUTABLE 0x0004 /* page may be mapped executable */
440 #define PGA_ENQUEUED 0x0008 /* page is enqueued in a page queue */
441 #define PGA_DEQUEUE 0x0010 /* page is due to be dequeued */
442 #define PGA_REQUEUE 0x0020 /* page is due to be requeued */
443 #define PGA_REQUEUE_HEAD 0x0040 /* page requeue should bypass LRU */
444 #define PGA_NOSYNC 0x0080 /* do not collect for syncer */
445 #define PGA_SWAP_FREE 0x0100 /* page with swap space was dirtied */
446 #define PGA_SWAP_SPACE 0x0200 /* page has allocated swap space */
448 #define PGA_QUEUE_OP_MASK (PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD)
449 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_QUEUE_OP_MASK)
452 * Page flags. Updates to these flags are not synchronized, and thus they must
453 * be set during page allocation or free to avoid races.
455 * The PG_PCPU_CACHE flag is set at allocation time if the page was
456 * allocated from a per-CPU cache. It is cleared the next time that the
457 * page is allocated from the physical memory allocator.
459 #define PG_PCPU_CACHE 0x01 /* was allocated from per-CPU caches */
460 #define PG_FICTITIOUS 0x02 /* physical page doesn't exist */
461 #define PG_ZERO 0x04 /* page is zeroed */
462 #define PG_MARKER 0x08 /* special queue marker page */
463 #define PG_NODUMP 0x10 /* don't include this page in a dump */
468 #define ACT_DECLINE 1
469 #define ACT_ADVANCE 3
475 #include <sys/systm.h>
477 #include <machine/atomic.h>
480 * Each pageable resident page falls into one of five lists:
483 * Available for allocation now.
486 * Low activity, candidates for reclamation.
487 * This list is approximately LRU ordered.
490 * This is the list of pages that should be
494 * Dirty anonymous pages that cannot be paged
495 * out because no swap device is configured.
498 * Pages that are "active", i.e., they have been
499 * recently referenced.
503 extern vm_page_t vm_page_array; /* First resident page in table */
504 extern long vm_page_array_size; /* number of vm_page_t's */
505 extern long first_page; /* first physical page number */
507 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
510 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory
511 * page to which the given physical address belongs. The correct vm_page_t
512 * object is returned for addresses that are not page-aligned.
514 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
517 * Page allocation parameters for vm_page for the functions
518 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and
519 * vm_page_alloc_freelist(). Some functions support only a subset
520 * of the flags, and ignore others, see the flags legend.
522 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*()
523 * and the vm_page_grab*() functions. See these functions for details.
525 * Bits 0 - 1 define class.
526 * Bits 2 - 15 dedicated for flags.
528 * (a) - vm_page_alloc() supports the flag.
529 * (c) - vm_page_alloc_contig() supports the flag.
530 * (g) - vm_page_grab() supports the flag.
531 * (n) - vm_page_alloc_noobj() and vm_page_alloc_freelist() support the flag.
532 * (p) - vm_page_grab_pages() supports the flag.
533 * Bits above 15 define the count of additional pages that the caller
534 * intends to allocate.
536 #define VM_ALLOC_NORMAL 0
537 #define VM_ALLOC_INTERRUPT 1
538 #define VM_ALLOC_SYSTEM 2
539 #define VM_ALLOC_CLASS_MASK 3
540 #define VM_ALLOC_WAITOK 0x0008 /* (acn) Sleep and retry */
541 #define VM_ALLOC_WAITFAIL 0x0010 /* (acn) Sleep and return error */
542 #define VM_ALLOC_WIRED 0x0020 /* (acgnp) Allocate a wired page */
543 #define VM_ALLOC_ZERO 0x0040 /* (acgnp) Allocate a zeroed page */
544 #define VM_ALLOC_NORECLAIM 0x0080 /* (c) Do not reclaim after failure */
545 #define VM_ALLOC_AVAIL0 0x0100
546 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */
547 #define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */
548 #define VM_ALLOC_AVAIL1 0x0800
549 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */
550 #define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */
551 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */
552 #define VM_ALLOC_NOWAIT 0x8000 /* (acgnp) Do not sleep */
553 #define VM_ALLOC_COUNT_MAX 0xffff
554 #define VM_ALLOC_COUNT_SHIFT 16
555 #define VM_ALLOC_COUNT_MASK (VM_ALLOC_COUNT(VM_ALLOC_COUNT_MAX))
556 #define VM_ALLOC_COUNT(count) ({ \
557 KASSERT((count) <= VM_ALLOC_COUNT_MAX, \
558 ("%s: invalid VM_ALLOC_COUNT value", __func__)); \
559 (count) << VM_ALLOC_COUNT_SHIFT; \
564 malloc2vm_flags(int malloc_flags)
568 KASSERT((malloc_flags & M_USE_RESERVE) == 0 ||
569 (malloc_flags & M_NOWAIT) != 0,
570 ("M_USE_RESERVE requires M_NOWAIT"));
571 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT :
573 if ((malloc_flags & M_ZERO) != 0)
574 pflags |= VM_ALLOC_ZERO;
575 if ((malloc_flags & M_NODUMP) != 0)
576 pflags |= VM_ALLOC_NODUMP;
577 if ((malloc_flags & M_NOWAIT))
578 pflags |= VM_ALLOC_NOWAIT;
579 if ((malloc_flags & M_WAITOK))
580 pflags |= VM_ALLOC_WAITOK;
581 if ((malloc_flags & M_NORECLAIM))
582 pflags |= VM_ALLOC_NORECLAIM;
588 * Predicates supported by vm_page_ps_test():
590 * PS_ALL_DIRTY is true only if the entire (super)page is dirty.
591 * However, it can be spuriously false when the (super)page has become
592 * dirty in the pmap but that information has not been propagated to the
593 * machine-independent layer.
595 #define PS_ALL_DIRTY 0x1
596 #define PS_ALL_VALID 0x2
597 #define PS_NONE_BUSY 0x4
599 bool vm_page_busy_acquire(vm_page_t m, int allocflags);
600 void vm_page_busy_downgrade(vm_page_t m);
601 int vm_page_busy_tryupgrade(vm_page_t m);
602 bool vm_page_busy_sleep(vm_page_t m, const char *msg, int allocflags);
603 void vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m,
604 vm_pindex_t pindex, const char *wmesg, int allocflags);
605 void vm_page_free(vm_page_t m);
606 void vm_page_free_zero(vm_page_t m);
608 void vm_page_activate (vm_page_t);
609 void vm_page_advise(vm_page_t m, int advice);
610 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int);
611 vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int);
612 vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t);
613 vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int,
615 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
616 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
617 vm_paddr_t boundary, vm_memattr_t memattr);
618 vm_page_t vm_page_alloc_contig_domain(vm_object_t object,
619 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low,
620 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
621 vm_memattr_t memattr);
622 vm_page_t vm_page_alloc_freelist(int, int);
623 vm_page_t vm_page_alloc_freelist_domain(int, int, int);
624 vm_page_t vm_page_alloc_noobj(int);
625 vm_page_t vm_page_alloc_noobj_domain(int, int);
626 vm_page_t vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low,
627 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
628 vm_memattr_t memattr);
629 vm_page_t vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages,
630 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
631 vm_memattr_t memattr);
632 void vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set);
633 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose);
634 vm_page_t vm_page_grab(vm_object_t, vm_pindex_t, int);
635 vm_page_t vm_page_grab_unlocked(vm_object_t, vm_pindex_t, int);
636 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
637 vm_page_t *ma, int count);
638 int vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex,
639 int allocflags, vm_page_t *ma, int count);
640 int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex,
642 int vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object,
643 vm_pindex_t pindex, int allocflags);
644 void vm_page_deactivate(vm_page_t);
645 void vm_page_deactivate_noreuse(vm_page_t);
646 void vm_page_dequeue(vm_page_t m);
647 void vm_page_dequeue_deferred(vm_page_t m);
648 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
649 void vm_page_free_invalid(vm_page_t);
650 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
651 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
652 void vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags);
653 void vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind);
654 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
655 void vm_page_invalid(vm_page_t m);
656 void vm_page_launder(vm_page_t m);
657 vm_page_t vm_page_lookup(vm_object_t, vm_pindex_t);
658 vm_page_t vm_page_lookup_unlocked(vm_object_t, vm_pindex_t);
659 vm_page_t vm_page_next(vm_page_t m);
660 void vm_page_pqbatch_drain(void);
661 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue);
662 bool vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old,
663 vm_page_astate_t new);
664 vm_page_t vm_page_prev(vm_page_t m);
665 bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m);
666 void vm_page_putfake(vm_page_t m);
667 void vm_page_readahead_finish(vm_page_t m);
668 bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low,
669 vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
670 bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
671 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
672 void vm_page_reference(vm_page_t m);
673 #define VPR_TRYFREE 0x01
674 #define VPR_NOREUSE 0x02
675 void vm_page_release(vm_page_t m, int flags);
676 void vm_page_release_locked(vm_page_t m, int flags);
677 vm_page_t vm_page_relookup(vm_object_t, vm_pindex_t);
678 bool vm_page_remove(vm_page_t);
679 bool vm_page_remove_xbusy(vm_page_t);
680 int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t);
681 void vm_page_replace(vm_page_t mnew, vm_object_t object,
682 vm_pindex_t pindex, vm_page_t mold);
683 int vm_page_sbusied(vm_page_t m);
684 vm_page_t vm_page_scan_contig(u_long npages, vm_page_t m_start,
685 vm_page_t m_end, u_long alignment, vm_paddr_t boundary, int options);
686 vm_page_bits_t vm_page_set_dirty(vm_page_t m);
687 void vm_page_set_valid_range(vm_page_t m, int base, int size);
688 vm_offset_t vm_page_startup(vm_offset_t vaddr);
689 void vm_page_sunbusy(vm_page_t m);
690 bool vm_page_try_remove_all(vm_page_t m);
691 bool vm_page_try_remove_write(vm_page_t m);
692 int vm_page_trysbusy(vm_page_t m);
693 int vm_page_tryxbusy(vm_page_t m);
694 void vm_page_unhold_pages(vm_page_t *ma, int count);
695 void vm_page_unswappable(vm_page_t m);
696 void vm_page_unwire(vm_page_t m, uint8_t queue);
697 bool vm_page_unwire_noq(vm_page_t m);
698 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
699 void vm_page_wire(vm_page_t);
700 bool vm_page_wire_mapped(vm_page_t m);
701 void vm_page_xunbusy_hard(vm_page_t m);
702 void vm_page_xunbusy_hard_unchecked(vm_page_t m);
703 void vm_page_set_validclean (vm_page_t, int, int);
704 void vm_page_clear_dirty(vm_page_t, int, int);
705 void vm_page_set_invalid(vm_page_t, int, int);
706 void vm_page_valid(vm_page_t m);
707 int vm_page_is_valid(vm_page_t, int, int);
708 void vm_page_test_dirty(vm_page_t);
709 vm_page_bits_t vm_page_bits(int base, int size);
710 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
711 void vm_page_free_pages_toq(struct spglist *free, bool update_wire_count);
713 void vm_page_dirty_KBI(vm_page_t m);
714 void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
715 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
716 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
717 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
718 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line);
719 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
722 #define vm_page_busy_fetch(m) atomic_load_int(&(m)->busy_lock)
724 #define vm_page_assert_busied(m) \
725 KASSERT(vm_page_busied(m), \
726 ("vm_page_assert_busied: page %p not busy @ %s:%d", \
727 (m), __FILE__, __LINE__))
729 #define vm_page_assert_sbusied(m) \
730 KASSERT(vm_page_sbusied(m), \
731 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \
732 (m), __FILE__, __LINE__))
734 #define vm_page_assert_unbusied(m) \
735 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) != \
736 VPB_CURTHREAD_EXCLUSIVE, \
737 ("vm_page_assert_xbusied: page %p busy_lock %#x owned" \
739 (m), (m)->busy_lock, __FILE__, __LINE__)); \
741 #define vm_page_assert_xbusied_unchecked(m) do { \
742 KASSERT(vm_page_xbusied(m), \
743 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \
744 (m), __FILE__, __LINE__)); \
746 #define vm_page_assert_xbusied(m) do { \
747 vm_page_assert_xbusied_unchecked(m); \
748 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) == \
749 VPB_CURTHREAD_EXCLUSIVE, \
750 ("vm_page_assert_xbusied: page %p busy_lock %#x not owned" \
752 (m), (m)->busy_lock, __FILE__, __LINE__)); \
755 #define vm_page_busied(m) \
756 (vm_page_busy_fetch(m) != VPB_UNBUSIED)
758 #define vm_page_xbusied(m) \
759 ((vm_page_busy_fetch(m) & VPB_SINGLE_EXCLUSIVE) != 0)
761 #define vm_page_busy_freed(m) \
762 (vm_page_busy_fetch(m) == VPB_FREED)
764 /* Note: page m's lock must not be owned by the caller. */
765 #define vm_page_xunbusy(m) do { \
766 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \
767 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \
768 vm_page_xunbusy_hard(m); \
770 #define vm_page_xunbusy_unchecked(m) do { \
771 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \
772 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \
773 vm_page_xunbusy_hard_unchecked(m); \
777 void vm_page_object_busy_assert(vm_page_t m);
778 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) vm_page_object_busy_assert(m)
779 void vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits);
780 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \
781 vm_page_assert_pga_writeable(m, bits)
783 * Claim ownership of a page's xbusy state. In non-INVARIANTS kernels this
784 * operation is a no-op since ownership is not tracked. In particular
785 * this macro does not provide any synchronization with the previous owner.
787 #define vm_page_xbusy_claim(m) do { \
790 vm_page_assert_xbusied_unchecked((m)); \
792 _busy_lock = vm_page_busy_fetch(m); \
793 } while (!atomic_cmpset_int(&(m)->busy_lock, _busy_lock, \
794 (_busy_lock & VPB_BIT_FLAGMASK) | VPB_CURTHREAD_EXCLUSIVE)); \
797 #define VM_PAGE_OBJECT_BUSY_ASSERT(m) (void)0
798 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0
799 #define vm_page_xbusy_claim(m)
802 #if BYTE_ORDER == BIG_ENDIAN
803 #define VM_PAGE_AFLAG_SHIFT 16
805 #define VM_PAGE_AFLAG_SHIFT 0
809 * Load a snapshot of a page's 32-bit atomic state.
811 static inline vm_page_astate_t
812 vm_page_astate_load(vm_page_t m)
816 a._bits = atomic_load_32(&m->a._bits);
821 * Atomically compare and set a page's atomic state.
824 vm_page_astate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new)
827 KASSERT(new.queue == PQ_INACTIVE || (new.flags & PGA_REQUEUE_HEAD) == 0,
828 ("%s: invalid head requeue request for page %p", __func__, m));
829 KASSERT((new.flags & PGA_ENQUEUED) == 0 || new.queue != PQ_NONE,
830 ("%s: setting PGA_ENQUEUED with PQ_NONE in page %p", __func__, m));
831 KASSERT(new._bits != old->_bits,
832 ("%s: bits are unchanged", __func__));
834 return (atomic_fcmpset_32(&m->a._bits, &old->_bits, new._bits) != 0);
838 * Clear the given bits in the specified page.
841 vm_page_aflag_clear(vm_page_t m, uint16_t bits)
846 * Access the whole 32-bit word containing the aflags field with an
847 * atomic update. Parallel non-atomic updates to the other fields
848 * within this word are handled properly by the atomic update.
850 addr = (void *)&m->a;
851 val = bits << VM_PAGE_AFLAG_SHIFT;
852 atomic_clear_32(addr, val);
856 * Set the given bits in the specified page.
859 vm_page_aflag_set(vm_page_t m, uint16_t bits)
863 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits);
866 * Access the whole 32-bit word containing the aflags field with an
867 * atomic update. Parallel non-atomic updates to the other fields
868 * within this word are handled properly by the atomic update.
870 addr = (void *)&m->a;
871 val = bits << VM_PAGE_AFLAG_SHIFT;
872 atomic_set_32(addr, val);
878 * Set all bits in the page's dirty field.
880 * The object containing the specified page must be locked if the
881 * call is made from the machine-independent layer.
883 * See vm_page_clear_dirty_mask().
886 vm_page_dirty(vm_page_t m)
889 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */
890 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS)
891 vm_page_dirty_KBI(m);
893 m->dirty = VM_PAGE_BITS_ALL;
900 * Set page to not be dirty. Note: does not clear pmap modify bits
903 vm_page_undirty(vm_page_t m)
906 VM_PAGE_OBJECT_BUSY_ASSERT(m);
910 static inline uint8_t
911 _vm_page_queue(vm_page_astate_t as)
914 if ((as.flags & PGA_DEQUEUE) != 0)
922 * Return the index of the queue containing m.
924 static inline uint8_t
925 vm_page_queue(vm_page_t m)
928 return (_vm_page_queue(vm_page_astate_load(m)));
932 vm_page_active(vm_page_t m)
935 return (vm_page_queue(m) == PQ_ACTIVE);
939 vm_page_inactive(vm_page_t m)
942 return (vm_page_queue(m) == PQ_INACTIVE);
946 vm_page_in_laundry(vm_page_t m)
950 queue = vm_page_queue(m);
951 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE);
957 * Release a reference to a page and return the old reference count.
960 vm_page_drop(vm_page_t m, u_int val)
965 * Synchronize with vm_page_free_prep(): ensure that all updates to the
966 * page structure are visible before it is freed.
968 atomic_thread_fence_rel();
969 old = atomic_fetchadd_int(&m->ref_count, -val);
970 KASSERT(old != VPRC_BLOCKED,
971 ("vm_page_drop: page %p has an invalid refcount value", m));
978 * Perform a racy check to determine whether a reference prevents the page
979 * from being reclaimable. If the page's object is locked, and the page is
980 * unmapped and exclusively busied by the current thread, no new wirings
984 vm_page_wired(vm_page_t m)
987 return (VPRC_WIRE_COUNT(m->ref_count) > 0);
991 vm_page_all_valid(vm_page_t m)
994 return (m->valid == VM_PAGE_BITS_ALL);
998 vm_page_none_valid(vm_page_t m)
1001 return (m->valid == 0);
1005 vm_page_domain(vm_page_t m)
1011 KASSERT(segind < vm_phys_nsegs, ("segind %d m %p", segind, m));
1012 domn = vm_phys_segs[segind].domain;
1013 KASSERT(domn >= 0 && domn < vm_ndomains, ("domain %d m %p", domn, m));
1020 #endif /* _KERNEL */
1021 #endif /* !_VM_PAGE_ */