master
1/*-
2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
35 *
36 *
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
39 *
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
41 *
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
47 *
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51 *
52 * Carnegie Mellon requests users of this software to return to
53 *
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
58 *
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
61 */
62
63/*
64 * Resident memory system definitions.
65 */
66
67#ifndef _VM_PAGE_
68#define _VM_PAGE_
69
70#include <vm/pmap.h>
71#include <vm/_vm_phys.h>
72
73/*
74 * Management of resident (logical) pages.
75 *
76 * A small structure is kept for each resident
77 * page, indexed by page number. Each structure
78 * is an element of several collections:
79 *
80 * A radix tree used to quickly
81 * perform object/offset lookups
82 *
83 * A list of all pages for a given object,
84 * so they can be quickly deactivated at
85 * time of deallocation.
86 *
87 * An ordered list of pages due for pageout.
88 *
89 * In addition, the structure contains the object
90 * and offset to which this page belongs (for pageout),
91 * and sundry status bits.
92 *
93 * In general, operations on this structure's mutable fields are
94 * synchronized using either one of or a combination of locks. If a
95 * field is annotated with two of these locks then holding either is
96 * sufficient for read access but both are required for write access.
97 * The queue lock for a page depends on the value of its queue field and is
98 * described in detail below.
99 *
100 * The following annotations are possible:
101 * (A) the field must be accessed using atomic(9) and may require
102 * additional synchronization.
103 * (B) the page busy lock.
104 * (C) the field is immutable.
105 * (F) the per-domain lock for the free queues.
106 * (M) Machine dependent, defined by pmap layer.
107 * (O) the object that the page belongs to.
108 * (Q) the page's queue lock.
109 *
110 * The busy lock is an embedded reader-writer lock that protects the
111 * page's contents and identity (i.e., its <object, pindex> tuple) as
112 * well as certain valid/dirty modifications. To avoid bloating the
113 * the page structure, the busy lock lacks some of the features available
114 * the kernel's general-purpose synchronization primitives. As a result,
115 * busy lock ordering rules are not verified, lock recursion is not
116 * detected, and an attempt to xbusy a busy page or sbusy an xbusy page
117 * results will trigger a panic rather than causing the thread to block.
118 * vm_page_sleep_if_busy() can be used to sleep until the page's busy
119 * state changes, after which the caller must re-lookup the page and
120 * re-evaluate its state. vm_page_busy_acquire() will block until
121 * the lock is acquired.
122 *
123 * The valid field is protected by the page busy lock (B) and object
124 * lock (O). Transitions from invalid to valid are generally done
125 * via I/O or zero filling and do not require the object lock.
126 * These must be protected with the busy lock to prevent page-in or
127 * creation races. Page invalidation generally happens as a result
128 * of truncate or msync. When invalidated, pages must not be present
129 * in pmap and must hold the object lock to prevent concurrent
130 * speculative read-only mappings that do not require busy. I/O
131 * routines may check for validity without a lock if they are prepared
132 * to handle invalidation races with higher level locks (vnode) or are
133 * unconcerned with races so long as they hold a reference to prevent
134 * recycling. When a valid bit is set while holding a shared busy
135 * lock (A) atomic operations are used to protect against concurrent
136 * modification.
137 *
138 * In contrast, the synchronization of accesses to the page's
139 * dirty field is a mix of machine dependent (M) and busy (B). In
140 * the machine-independent layer, the page busy must be held to
141 * operate on the field. However, the pmap layer is permitted to
142 * set all bits within the field without holding that lock. If the
143 * underlying architecture does not support atomic read-modify-write
144 * operations on the field's type, then the machine-independent
145 * layer uses a 32-bit atomic on the aligned 32-bit word that
146 * contains the dirty field. In the machine-independent layer,
147 * the implementation of read-modify-write operations on the
148 * field is encapsulated in vm_page_clear_dirty_mask(). An
149 * exclusive busy lock combined with pmap_remove_{write/all}() is the
150 * only way to ensure a page can not become dirty. I/O generally
151 * removes the page from pmap to ensure exclusive access and atomic
152 * writes.
153 *
154 * The ref_count field tracks references to the page. References that
155 * prevent the page from being reclaimable are called wirings and are
156 * counted in the low bits of ref_count. The containing object's
157 * reference, if one exists, is counted using the VPRC_OBJREF bit in the
158 * ref_count field. Additionally, the VPRC_BLOCKED bit is used to
159 * atomically check for wirings and prevent new wirings via
160 * pmap_extract_and_hold(). When a page belongs to an object, it may be
161 * wired only when the object is locked, or the page is busy, or by
162 * pmap_extract_and_hold(). As a result, if the object is locked and the
163 * page is not busy (or is exclusively busied by the current thread), and
164 * the page is unmapped, its wire count will not increase. The ref_count
165 * field is updated using atomic operations in most cases, except when it
166 * is known that no other references to the page exist, such as in the page
167 * allocator. A page may be present in the page queues, or even actively
168 * scanned by the page daemon, without an explicitly counted referenced.
169 * The page daemon must therefore handle the possibility of a concurrent
170 * free of the page.
171 *
172 * The queue state of a page consists of the queue and act_count fields of
173 * its atomically updated state, and the subset of atomic flags specified
174 * by PGA_QUEUE_STATE_MASK. The queue field contains the page's page queue
175 * index, or PQ_NONE if it does not belong to a page queue. To modify the
176 * queue field, the page queue lock corresponding to the old value must be
177 * held, unless that value is PQ_NONE, in which case the queue index must
178 * be updated using an atomic RMW operation. There is one exception to
179 * this rule: the page daemon may transition the queue field from
180 * PQ_INACTIVE to PQ_NONE immediately prior to freeing the page during an
181 * inactive queue scan. At that point the page is already dequeued and no
182 * other references to that vm_page structure can exist. The PGA_ENQUEUED
183 * flag, when set, indicates that the page structure is physically inserted
184 * into the queue corresponding to the page's queue index, and may only be
185 * set or cleared with the corresponding page queue lock held.
186 *
187 * To avoid contention on page queue locks, page queue operations (enqueue,
188 * dequeue, requeue) are batched using fixed-size per-CPU queues. A
189 * deferred operation is requested by setting one of the flags in
190 * PGA_QUEUE_OP_MASK and inserting an entry into a batch queue. When a
191 * queue is full, an attempt to insert a new entry will lock the page
192 * queues and trigger processing of the pending entries. The
193 * type-stability of vm_page structures is crucial to this scheme since the
194 * processing of entries in a given batch queue may be deferred
195 * indefinitely. In particular, a page may be freed with pending batch
196 * queue entries. The page queue operation flags must be set using atomic
197 * RWM operations.
198 */
199
200#if PAGE_SIZE == 4096
201#define VM_PAGE_BITS_ALL 0xffu
202typedef uint8_t vm_page_bits_t;
203#elif PAGE_SIZE == 8192
204#define VM_PAGE_BITS_ALL 0xffffu
205typedef uint16_t vm_page_bits_t;
206#elif PAGE_SIZE == 16384
207#define VM_PAGE_BITS_ALL 0xffffffffu
208typedef uint32_t vm_page_bits_t;
209#elif PAGE_SIZE == 32768
210#define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
211typedef uint64_t vm_page_bits_t;
212#endif
213
214typedef union vm_page_astate {
215 struct {
216 uint16_t flags;
217 uint8_t queue;
218 uint8_t act_count;
219 };
220 uint32_t _bits;
221} vm_page_astate_t;
222
223struct vm_page {
224 union {
225 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */
226 struct {
227 SLIST_ENTRY(vm_page) ss; /* private slists */
228 } s;
229 struct {
230 u_long p;
231 u_long v;
232 } memguard;
233 struct {
234 void *slab;
235 void *zone;
236 } uma;
237 } plinks;
238 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
239 vm_object_t object; /* which object am I in (O) */
240 vm_pindex_t pindex; /* offset into object (O,P) */
241 vm_paddr_t phys_addr; /* physical address of page (C) */
242 struct md_page md; /* machine dependent stuff */
243 u_int ref_count; /* page references (A) */
244 u_int busy_lock; /* busy owners lock (A) */
245 union vm_page_astate a; /* state accessed atomically (A) */
246 uint8_t order; /* index of the buddy queue (F) */
247 uint8_t pool; /* vm_phys freepool index (F) */
248 uint8_t flags; /* page PG_* flags (P) */
249 uint8_t oflags; /* page VPO_* flags (O) */
250 int8_t psind; /* pagesizes[] index (O) */
251 int8_t segind; /* vm_phys segment index (C) */
252 /* NOTE that these must support one bit per DEV_BSIZE in a page */
253 /* so, on normal X86 kernels, they must be at least 8 bits wide */
254 vm_page_bits_t valid; /* valid DEV_BSIZE chunk map (O,B) */
255 vm_page_bits_t dirty; /* dirty DEV_BSIZE chunk map (M,B) */
256};
257
258/*
259 * Special bits used in the ref_count field.
260 *
261 * ref_count is normally used to count wirings that prevent the page from being
262 * reclaimed, but also supports several special types of references that do not
263 * prevent reclamation. Accesses to the ref_count field must be atomic unless
264 * the page is unallocated.
265 *
266 * VPRC_OBJREF is the reference held by the containing object. It can set or
267 * cleared only when the corresponding object's write lock is held.
268 *
269 * VPRC_BLOCKED is used to atomically block wirings via pmap lookups while
270 * attempting to tear down all mappings of a given page. The page busy lock and
271 * object write lock must both be held in order to set or clear this bit.
272 */
273#define VPRC_BLOCKED 0x40000000u /* mappings are being removed */
274#define VPRC_OBJREF 0x80000000u /* object reference, cleared with (O) */
275#define VPRC_WIRE_COUNT(c) ((c) & ~(VPRC_BLOCKED | VPRC_OBJREF))
276#define VPRC_WIRE_COUNT_MAX (~(VPRC_BLOCKED | VPRC_OBJREF))
277
278/*
279 * Page flags stored in oflags:
280 *
281 * Access to these page flags is synchronized by the lock on the object
282 * containing the page (O).
283 *
284 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
285 * indicates that the page is not under PV management but
286 * otherwise should be treated as a normal page. Pages not
287 * under PV management cannot be paged out via the
288 * object/vm_page_t because there is no knowledge of their pte
289 * mappings, and such pages are also not on any PQ queue.
290 *
291 */
292#define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */
293#define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */
294#define VPO_UNMANAGED 0x04 /* no PV management for page */
295#define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */
296
297/*
298 * Busy page implementation details.
299 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation,
300 * even if the support for owner identity is removed because of size
301 * constraints. Checks on lock recursion are then not possible, while the
302 * lock assertions effectiveness is someway reduced.
303 */
304#define VPB_BIT_SHARED 0x01
305#define VPB_BIT_EXCLUSIVE 0x02
306#define VPB_BIT_WAITERS 0x04
307#define VPB_BIT_FLAGMASK \
308 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS)
309
310#define VPB_SHARERS_SHIFT 3
311#define VPB_SHARERS(x) \
312 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT)
313#define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED)
314#define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT)
315
316#define VPB_SINGLE_EXCLUSIVE VPB_BIT_EXCLUSIVE
317#ifdef INVARIANTS
318#define VPB_CURTHREAD_EXCLUSIVE \
319 (VPB_BIT_EXCLUSIVE | ((u_int)(uintptr_t)curthread & ~VPB_BIT_FLAGMASK))
320#else
321#define VPB_CURTHREAD_EXCLUSIVE VPB_SINGLE_EXCLUSIVE
322#endif
323
324#define VPB_UNBUSIED VPB_SHARERS_WORD(0)
325
326/* Freed lock blocks both shared and exclusive. */
327#define VPB_FREED (0xffffffff - VPB_BIT_SHARED)
328
329#define PQ_NONE 255
330#define PQ_INACTIVE 0
331#define PQ_ACTIVE 1
332#define PQ_LAUNDRY 2
333#define PQ_UNSWAPPABLE 3
334#define PQ_COUNT 4
335
336#ifndef VM_PAGE_HAVE_PGLIST
337TAILQ_HEAD(pglist, vm_page);
338#define VM_PAGE_HAVE_PGLIST
339#endif
340SLIST_HEAD(spglist, vm_page);
341
342#ifdef _KERNEL
343extern vm_page_t bogus_page;
344#endif /* _KERNEL */
345
346extern struct mtx_padalign pa_lock[];
347
348#if defined(__arm__)
349#define PDRSHIFT PDR_SHIFT
350#elif !defined(PDRSHIFT)
351#define PDRSHIFT 21
352#endif
353
354#define pa_index(pa) ((pa) >> PDRSHIFT)
355#define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT]))
356#define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
357#define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
358#define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
359#define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
360#define PA_UNLOCK_COND(pa) \
361 do { \
362 if ((pa) != 0) { \
363 PA_UNLOCK((pa)); \
364 (pa) = 0; \
365 } \
366 } while (0)
367
368#define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
369
370#if defined(KLD_MODULE) && !defined(KLD_TIED)
371#define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
372#define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
373#define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
374#else /* !KLD_MODULE */
375#define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
376#define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
377#define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
378#define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
379#endif
380#if defined(INVARIANTS)
381#define vm_page_assert_locked(m) \
382 vm_page_assert_locked_KBI((m), __FILE__, __LINE__)
383#define vm_page_lock_assert(m, a) \
384 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__)
385#else
386#define vm_page_assert_locked(m)
387#define vm_page_lock_assert(m, a)
388#endif
389
390/*
391 * The vm_page's aflags are updated using atomic operations. To set or clear
392 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear()
393 * must be used. Neither these flags nor these functions are part of the KBI.
394 *
395 * PGA_REFERENCED may be cleared only if the page is locked. It is set by
396 * both the MI and MD VM layers. However, kernel loadable modules should not
397 * directly set this flag. They should call vm_page_reference() instead.
398 *
399 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter().
400 * When it does so, the object must be locked, or the page must be
401 * exclusive busied. The MI VM layer must never access this flag
402 * directly. Instead, it should call pmap_page_is_write_mapped().
403 *
404 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has
405 * at least one executable mapping. It is not consumed by the MI VM layer.
406 *
407 * PGA_NOSYNC must be set and cleared with the page busy lock held.
408 *
409 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed
410 * from a page queue, respectively. It determines whether the plinks.q field
411 * of the page is valid. To set or clear this flag, page's "queue" field must
412 * be a valid queue index, and the corresponding page queue lock must be held.
413 *
414 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page
415 * queue, and cleared when the dequeue request is processed. A page may
416 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue
417 * is requested after the page is scheduled to be enqueued but before it is
418 * actually inserted into the page queue.
419 *
420 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued
421 * in its page queue.
422 *
423 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of
424 * the inactive queue, thus bypassing LRU.
425 *
426 * The PGA_DEQUEUE, PGA_REQUEUE and PGA_REQUEUE_HEAD flags must be set using an
427 * atomic RMW operation to ensure that the "queue" field is a valid queue index,
428 * and the corresponding page queue lock must be held when clearing any of the
429 * flags.
430 *
431 * PGA_SWAP_FREE is used to defer freeing swap space to the pageout daemon
432 * when the context that dirties the page does not have the object write lock
433 * held.
434 */
435#define PGA_WRITEABLE 0x0001 /* page may be mapped writeable */
436#define PGA_REFERENCED 0x0002 /* page has been referenced */
437#define PGA_EXECUTABLE 0x0004 /* page may be mapped executable */
438#define PGA_ENQUEUED 0x0008 /* page is enqueued in a page queue */
439#define PGA_DEQUEUE 0x0010 /* page is due to be dequeued */
440#define PGA_REQUEUE 0x0020 /* page is due to be requeued */
441#define PGA_REQUEUE_HEAD 0x0040 /* page requeue should bypass LRU */
442#define PGA_NOSYNC 0x0080 /* do not collect for syncer */
443#define PGA_SWAP_FREE 0x0100 /* page with swap space was dirtied */
444#define PGA_SWAP_SPACE 0x0200 /* page has allocated swap space */
445
446#define PGA_QUEUE_OP_MASK (PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD)
447#define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_QUEUE_OP_MASK)
448
449/*
450 * Page flags. Updates to these flags are not synchronized, and thus they must
451 * be set during page allocation or free to avoid races.
452 *
453 * The PG_PCPU_CACHE flag is set at allocation time if the page was
454 * allocated from a per-CPU cache. It is cleared the next time that the
455 * page is allocated from the physical memory allocator.
456 */
457#define PG_PCPU_CACHE 0x01 /* was allocated from per-CPU caches */
458#define PG_FICTITIOUS 0x02 /* physical page doesn't exist */
459#define PG_ZERO 0x04 /* page is zeroed */
460#define PG_MARKER 0x08 /* special queue marker page */
461#define PG_NODUMP 0x10 /* don't include this page in a dump */
462
463/*
464 * Misc constants.
465 */
466#define ACT_DECLINE 1
467#define ACT_ADVANCE 3
468#define ACT_INIT 5
469#define ACT_MAX 64
470
471#ifdef _KERNEL
472
473#include <sys/kassert.h>
474#include <machine/atomic.h>
475
476/*
477 * Each pageable resident page falls into one of five lists:
478 *
479 * free
480 * Available for allocation now.
481 *
482 * inactive
483 * Low activity, candidates for reclamation.
484 * This list is approximately LRU ordered.
485 *
486 * laundry
487 * This is the list of pages that should be
488 * paged out next.
489 *
490 * unswappable
491 * Dirty anonymous pages that cannot be paged
492 * out because no swap device is configured.
493 *
494 * active
495 * Pages that are "active", i.e., they have been
496 * recently referenced.
497 *
498 */
499
500extern vm_page_t vm_page_array; /* First resident page in table */
501extern long vm_page_array_size; /* number of vm_page_t's */
502extern long first_page; /* first physical page number */
503
504#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
505
506/*
507 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory
508 * page to which the given physical address belongs. The correct vm_page_t
509 * object is returned for addresses that are not page-aligned.
510 */
511vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
512
513/*
514 * Page allocation parameters for vm_page for the functions
515 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and
516 * vm_page_alloc_freelist(). Some functions support only a subset
517 * of the flags, and ignore others, see the flags legend.
518 *
519 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*()
520 * and the vm_page_grab*() functions. See these functions for details.
521 *
522 * Bits 0 - 1 define class.
523 * Bits 2 - 15 dedicated for flags.
524 * Legend:
525 * (a) - vm_page_alloc() supports the flag.
526 * (c) - vm_page_alloc_contig() supports the flag.
527 * (g) - vm_page_grab() supports the flag.
528 * (n) - vm_page_alloc_noobj() and vm_page_alloc_freelist() support the flag.
529 * (p) - vm_page_grab_pages() supports the flag.
530 * Bits above 15 define the count of additional pages that the caller
531 * intends to allocate.
532 */
533#define VM_ALLOC_NORMAL 0
534#define VM_ALLOC_INTERRUPT 1
535#define VM_ALLOC_SYSTEM 2
536#define VM_ALLOC_CLASS_MASK 3
537#define VM_ALLOC_WAITOK 0x0008 /* (acn) Sleep and retry */
538#define VM_ALLOC_WAITFAIL 0x0010 /* (acn) Sleep and return error */
539#define VM_ALLOC_WIRED 0x0020 /* (acgnp) Allocate a wired page */
540#define VM_ALLOC_ZERO 0x0040 /* (acgnp) Allocate a zeroed page */
541#define VM_ALLOC_NORECLAIM 0x0080 /* (c) Do not reclaim after failure */
542#define VM_ALLOC_AVAIL0 0x0100
543#define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */
544#define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */
545#define VM_ALLOC_AVAIL1 0x0800
546#define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */
547#define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */
548#define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */
549#define VM_ALLOC_NOWAIT 0x8000 /* (acgnp) Do not sleep */
550#define VM_ALLOC_COUNT_MAX 0xffff
551#define VM_ALLOC_COUNT_SHIFT 16
552#define VM_ALLOC_COUNT_MASK (VM_ALLOC_COUNT(VM_ALLOC_COUNT_MAX))
553#define VM_ALLOC_COUNT(count) ({ \
554 KASSERT((count) <= VM_ALLOC_COUNT_MAX, \
555 ("%s: invalid VM_ALLOC_COUNT value", __func__)); \
556 (count) << VM_ALLOC_COUNT_SHIFT; \
557})
558
559#ifdef M_NOWAIT
560static inline int
561malloc2vm_flags(int malloc_flags)
562{
563 int pflags;
564
565 KASSERT((malloc_flags & M_USE_RESERVE) == 0 ||
566 (malloc_flags & M_NOWAIT) != 0,
567 ("M_USE_RESERVE requires M_NOWAIT"));
568 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT :
569 VM_ALLOC_SYSTEM;
570 if ((malloc_flags & M_ZERO) != 0)
571 pflags |= VM_ALLOC_ZERO;
572 if ((malloc_flags & M_NODUMP) != 0)
573 pflags |= VM_ALLOC_NODUMP;
574 if ((malloc_flags & M_NOWAIT))
575 pflags |= VM_ALLOC_NOWAIT;
576 if ((malloc_flags & M_WAITOK))
577 pflags |= VM_ALLOC_WAITOK;
578 if ((malloc_flags & M_NORECLAIM))
579 pflags |= VM_ALLOC_NORECLAIM;
580 return (pflags);
581}
582#endif
583
584/*
585 * Predicates supported by vm_page_ps_test():
586 *
587 * PS_ALL_DIRTY is true only if the entire (super)page is dirty.
588 * However, it can be spuriously false when the (super)page has become
589 * dirty in the pmap but that information has not been propagated to the
590 * machine-independent layer.
591 */
592#define PS_ALL_DIRTY 0x1
593#define PS_ALL_VALID 0x2
594#define PS_NONE_BUSY 0x4
595
596bool vm_page_busy_acquire(vm_page_t m, int allocflags);
597void vm_page_busy_downgrade(vm_page_t m);
598int vm_page_busy_tryupgrade(vm_page_t m);
599bool vm_page_busy_sleep(vm_page_t m, const char *msg, int allocflags);
600void vm_page_busy_sleep_unlocked(vm_object_t obj, vm_page_t m,
601 vm_pindex_t pindex, const char *wmesg, int allocflags);
602void vm_page_free(vm_page_t m);
603void vm_page_free_zero(vm_page_t m);
604
605void vm_page_activate (vm_page_t);
606void vm_page_advise(vm_page_t m, int advice);
607vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int);
608vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int);
609vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t);
610vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int,
611 vm_page_t);
612vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
613 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
614 vm_paddr_t boundary, vm_memattr_t memattr);
615vm_page_t vm_page_alloc_contig_domain(vm_object_t object,
616 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low,
617 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
618 vm_memattr_t memattr);
619vm_page_t vm_page_alloc_freelist(int, int);
620vm_page_t vm_page_alloc_freelist_domain(int, int, int);
621vm_page_t vm_page_alloc_noobj(int);
622vm_page_t vm_page_alloc_noobj_domain(int, int);
623vm_page_t vm_page_alloc_noobj_contig(int req, u_long npages, vm_paddr_t low,
624 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
625 vm_memattr_t memattr);
626vm_page_t vm_page_alloc_noobj_contig_domain(int domain, int req, u_long npages,
627 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
628 vm_memattr_t memattr);
629void vm_page_bits_set(vm_page_t m, vm_page_bits_t *bits, vm_page_bits_t set);
630bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose);
631vm_page_t vm_page_grab(vm_object_t, vm_pindex_t, int);
632vm_page_t vm_page_grab_unlocked(vm_object_t, vm_pindex_t, int);
633int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
634 vm_page_t *ma, int count);
635int vm_page_grab_pages_unlocked(vm_object_t object, vm_pindex_t pindex,
636 int allocflags, vm_page_t *ma, int count);
637int vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex,
638 int allocflags);
639int vm_page_grab_valid_unlocked(vm_page_t *mp, vm_object_t object,
640 vm_pindex_t pindex, int allocflags);
641void vm_page_deactivate(vm_page_t);
642void vm_page_deactivate_noreuse(vm_page_t);
643void vm_page_dequeue(vm_page_t m);
644void vm_page_dequeue_deferred(vm_page_t m);
645vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
646void vm_page_free_invalid(vm_page_t);
647vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
648void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
649void vm_page_init_marker(vm_page_t marker, int queue, uint16_t aflags);
650void vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind);
651int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
652void vm_page_invalid(vm_page_t m);
653void vm_page_launder(vm_page_t m);
654vm_page_t vm_page_lookup(vm_object_t, vm_pindex_t);
655vm_page_t vm_page_lookup_unlocked(vm_object_t, vm_pindex_t);
656vm_page_t vm_page_next(vm_page_t m);
657void vm_page_pqbatch_drain(void);
658void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue);
659bool vm_page_pqstate_commit(vm_page_t m, vm_page_astate_t *old,
660 vm_page_astate_t new);
661vm_page_t vm_page_prev(vm_page_t m);
662bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m);
663void vm_page_putfake(vm_page_t m);
664void vm_page_readahead_finish(vm_page_t m);
665bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low,
666 vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
667bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
668 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
669bool vm_page_reclaim_contig_domain_ext(int domain, int req, u_long npages,
670 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
671 int desired_runs);
672void vm_page_reference(vm_page_t m);
673#define VPR_TRYFREE 0x01
674#define VPR_NOREUSE 0x02
675void vm_page_release(vm_page_t m, int flags);
676void vm_page_release_locked(vm_page_t m, int flags);
677vm_page_t vm_page_relookup(vm_object_t, vm_pindex_t);
678bool vm_page_remove(vm_page_t);
679bool vm_page_remove_xbusy(vm_page_t);
680int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t);
681void vm_page_replace(vm_page_t mnew, vm_object_t object,
682 vm_pindex_t pindex, vm_page_t mold);
683int vm_page_sbusied(vm_page_t m);
684vm_page_bits_t vm_page_set_dirty(vm_page_t m);
685void vm_page_set_valid_range(vm_page_t m, int base, int size);
686vm_offset_t vm_page_startup(vm_offset_t vaddr);
687void vm_page_sunbusy(vm_page_t m);
688bool vm_page_try_remove_all(vm_page_t m);
689bool vm_page_try_remove_write(vm_page_t m);
690int vm_page_trysbusy(vm_page_t m);
691int vm_page_tryxbusy(vm_page_t m);
692void vm_page_unhold_pages(vm_page_t *ma, int count);
693void vm_page_unswappable(vm_page_t m);
694void vm_page_unwire(vm_page_t m, uint8_t queue);
695bool vm_page_unwire_noq(vm_page_t m);
696void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
697void vm_page_wire(vm_page_t);
698bool vm_page_wire_mapped(vm_page_t m);
699void vm_page_xunbusy_hard(vm_page_t m);
700void vm_page_xunbusy_hard_unchecked(vm_page_t m);
701void vm_page_set_validclean (vm_page_t, int, int);
702void vm_page_clear_dirty(vm_page_t, int, int);
703void vm_page_set_invalid(vm_page_t, int, int);
704void vm_page_valid(vm_page_t m);
705int vm_page_is_valid(vm_page_t, int, int);
706void vm_page_test_dirty(vm_page_t);
707vm_page_bits_t vm_page_bits(int base, int size);
708void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
709int vm_page_free_pages_toq(struct spglist *free, bool update_wire_count);
710
711void vm_page_dirty_KBI(vm_page_t m);
712void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
713void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
714int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
715#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
716void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line);
717void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
718#endif
719
720#define vm_page_busy_fetch(m) atomic_load_int(&(m)->busy_lock)
721
722#define vm_page_assert_busied(m) \
723 KASSERT(vm_page_busied(m), \
724 ("vm_page_assert_busied: page %p not busy @ %s:%d", \
725 (m), __FILE__, __LINE__))
726
727#define vm_page_assert_sbusied(m) \
728 KASSERT(vm_page_sbusied(m), \
729 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \
730 (m), __FILE__, __LINE__))
731
732#define vm_page_assert_unbusied(m) \
733 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) != \
734 VPB_CURTHREAD_EXCLUSIVE, \
735 ("vm_page_assert_xbusied: page %p busy_lock %#x owned" \
736 " by me @ %s:%d", \
737 (m), (m)->busy_lock, __FILE__, __LINE__)); \
738
739#define vm_page_assert_xbusied_unchecked(m) do { \
740 KASSERT(vm_page_xbusied(m), \
741 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \
742 (m), __FILE__, __LINE__)); \
743} while (0)
744#define vm_page_assert_xbusied(m) do { \
745 vm_page_assert_xbusied_unchecked(m); \
746 KASSERT((vm_page_busy_fetch(m) & ~VPB_BIT_WAITERS) == \
747 VPB_CURTHREAD_EXCLUSIVE, \
748 ("vm_page_assert_xbusied: page %p busy_lock %#x not owned" \
749 " by me @ %s:%d", \
750 (m), (m)->busy_lock, __FILE__, __LINE__)); \
751} while (0)
752
753#define vm_page_busied(m) \
754 (vm_page_busy_fetch(m) != VPB_UNBUSIED)
755
756#define vm_page_xbusied(m) \
757 ((vm_page_busy_fetch(m) & VPB_SINGLE_EXCLUSIVE) != 0)
758
759#define vm_page_busy_freed(m) \
760 (vm_page_busy_fetch(m) == VPB_FREED)
761
762/* Note: page m's lock must not be owned by the caller. */
763#define vm_page_xunbusy(m) do { \
764 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \
765 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \
766 vm_page_xunbusy_hard(m); \
767} while (0)
768#define vm_page_xunbusy_unchecked(m) do { \
769 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \
770 VPB_CURTHREAD_EXCLUSIVE, VPB_UNBUSIED)) \
771 vm_page_xunbusy_hard_unchecked(m); \
772} while (0)
773
774#ifdef INVARIANTS
775void vm_page_object_busy_assert(vm_page_t m);
776#define VM_PAGE_OBJECT_BUSY_ASSERT(m) vm_page_object_busy_assert(m)
777void vm_page_assert_pga_writeable(vm_page_t m, uint16_t bits);
778#define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \
779 vm_page_assert_pga_writeable(m, bits)
780/*
781 * Claim ownership of a page's xbusy state. In non-INVARIANTS kernels this
782 * operation is a no-op since ownership is not tracked. In particular
783 * this macro does not provide any synchronization with the previous owner.
784 */
785#define vm_page_xbusy_claim(m) do { \
786 u_int _busy_lock; \
787 \
788 vm_page_assert_xbusied_unchecked((m)); \
789 do { \
790 _busy_lock = vm_page_busy_fetch(m); \
791 } while (!atomic_cmpset_int(&(m)->busy_lock, _busy_lock, \
792 (_busy_lock & VPB_BIT_FLAGMASK) | VPB_CURTHREAD_EXCLUSIVE)); \
793} while (0)
794#else
795#define VM_PAGE_OBJECT_BUSY_ASSERT(m) (void)0
796#define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0
797#define vm_page_xbusy_claim(m)
798#endif
799
800#if BYTE_ORDER == BIG_ENDIAN
801#define VM_PAGE_AFLAG_SHIFT 16
802#else
803#define VM_PAGE_AFLAG_SHIFT 0
804#endif
805
806/*
807 * Load a snapshot of a page's 32-bit atomic state.
808 */
809static inline vm_page_astate_t
810vm_page_astate_load(vm_page_t m)
811{
812 vm_page_astate_t a;
813
814 a._bits = atomic_load_32(&m->a._bits);
815 return (a);
816}
817
818/*
819 * Atomically compare and set a page's atomic state.
820 */
821static inline bool
822vm_page_astate_fcmpset(vm_page_t m, vm_page_astate_t *old, vm_page_astate_t new)
823{
824
825 KASSERT(new.queue == PQ_INACTIVE || (new.flags & PGA_REQUEUE_HEAD) == 0,
826 ("%s: invalid head requeue request for page %p", __func__, m));
827 KASSERT((new.flags & PGA_ENQUEUED) == 0 || new.queue != PQ_NONE,
828 ("%s: setting PGA_ENQUEUED with PQ_NONE in page %p", __func__, m));
829 KASSERT(new._bits != old->_bits,
830 ("%s: bits are unchanged", __func__));
831
832 return (atomic_fcmpset_32(&m->a._bits, &old->_bits, new._bits) != 0);
833}
834
835/*
836 * Clear the given bits in the specified page.
837 */
838static inline void
839vm_page_aflag_clear(vm_page_t m, uint16_t bits)
840{
841 uint32_t *addr, val;
842
843 /*
844 * Access the whole 32-bit word containing the aflags field with an
845 * atomic update. Parallel non-atomic updates to the other fields
846 * within this word are handled properly by the atomic update.
847 */
848 addr = (void *)&m->a;
849 val = bits << VM_PAGE_AFLAG_SHIFT;
850 atomic_clear_32(addr, val);
851}
852
853/*
854 * Set the given bits in the specified page.
855 */
856static inline void
857vm_page_aflag_set(vm_page_t m, uint16_t bits)
858{
859 uint32_t *addr, val;
860
861 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits);
862
863 /*
864 * Access the whole 32-bit word containing the aflags field with an
865 * atomic update. Parallel non-atomic updates to the other fields
866 * within this word are handled properly by the atomic update.
867 */
868 addr = (void *)&m->a;
869 val = bits << VM_PAGE_AFLAG_SHIFT;
870 atomic_set_32(addr, val);
871}
872
873/*
874 * vm_page_dirty:
875 *
876 * Set all bits in the page's dirty field.
877 *
878 * The object containing the specified page must be locked if the
879 * call is made from the machine-independent layer.
880 *
881 * See vm_page_clear_dirty_mask().
882 */
883static __inline void
884vm_page_dirty(vm_page_t m)
885{
886
887 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */
888#if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS)
889 vm_page_dirty_KBI(m);
890#else
891 m->dirty = VM_PAGE_BITS_ALL;
892#endif
893}
894
895/*
896 * vm_page_undirty:
897 *
898 * Set page to not be dirty. Note: does not clear pmap modify bits
899 */
900static __inline void
901vm_page_undirty(vm_page_t m)
902{
903
904 VM_PAGE_OBJECT_BUSY_ASSERT(m);
905 m->dirty = 0;
906}
907
908static inline uint8_t
909_vm_page_queue(vm_page_astate_t as)
910{
911
912 if ((as.flags & PGA_DEQUEUE) != 0)
913 return (PQ_NONE);
914 return (as.queue);
915}
916
917/*
918 * vm_page_queue:
919 *
920 * Return the index of the queue containing m.
921 */
922static inline uint8_t
923vm_page_queue(vm_page_t m)
924{
925
926 return (_vm_page_queue(vm_page_astate_load(m)));
927}
928
929static inline bool
930vm_page_active(vm_page_t m)
931{
932
933 return (vm_page_queue(m) == PQ_ACTIVE);
934}
935
936static inline bool
937vm_page_inactive(vm_page_t m)
938{
939
940 return (vm_page_queue(m) == PQ_INACTIVE);
941}
942
943static inline bool
944vm_page_in_laundry(vm_page_t m)
945{
946 uint8_t queue;
947
948 queue = vm_page_queue(m);
949 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE);
950}
951
952static inline void
953vm_page_clearref(vm_page_t m)
954{
955 u_int r;
956
957 r = m->ref_count;
958 while (atomic_fcmpset_int(&m->ref_count, &r, r & (VPRC_BLOCKED |
959 VPRC_OBJREF)) == 0)
960 ;
961}
962
963/*
964 * vm_page_drop:
965 *
966 * Release a reference to a page and return the old reference count.
967 */
968static inline u_int
969vm_page_drop(vm_page_t m, u_int val)
970{
971 u_int old;
972
973 /*
974 * Synchronize with vm_page_free_prep(): ensure that all updates to the
975 * page structure are visible before it is freed.
976 */
977 atomic_thread_fence_rel();
978 old = atomic_fetchadd_int(&m->ref_count, -val);
979 KASSERT(old != VPRC_BLOCKED,
980 ("vm_page_drop: page %p has an invalid refcount value", m));
981 return (old);
982}
983
984/*
985 * vm_page_wired:
986 *
987 * Perform a racy check to determine whether a reference prevents the page
988 * from being reclaimable. If the page's object is locked, and the page is
989 * unmapped and exclusively busied by the current thread, no new wirings
990 * may be created.
991 */
992static inline bool
993vm_page_wired(vm_page_t m)
994{
995
996 return (VPRC_WIRE_COUNT(m->ref_count) > 0);
997}
998
999static inline bool
1000vm_page_all_valid(vm_page_t m)
1001{
1002
1003 return (m->valid == VM_PAGE_BITS_ALL);
1004}
1005
1006static inline bool
1007vm_page_any_valid(vm_page_t m)
1008{
1009
1010 return (m->valid != 0);
1011}
1012
1013static inline bool
1014vm_page_none_valid(vm_page_t m)
1015{
1016
1017 return (m->valid == 0);
1018}
1019
1020static inline int
1021vm_page_domain(vm_page_t m)
1022{
1023#ifdef NUMA
1024 int domn, segind;
1025
1026 segind = m->segind;
1027 KASSERT(segind < vm_phys_nsegs, ("segind %d m %p", segind, m));
1028 domn = vm_phys_segs[segind].domain;
1029 KASSERT(domn >= 0 && domn < vm_ndomains, ("domain %d m %p", domn, m));
1030 return (domn);
1031#else
1032 return (0);
1033#endif
1034}
1035
1036#endif /* _KERNEL */
1037#endif /* !_VM_PAGE_ */