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freebsd-dev/sys/vm/vm_page.h

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/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
/*
* Resident memory system definitions.
*/
#ifndef _VM_PAGE_
#define _VM_PAGE_
#include <vm/pmap.h>
/*
* Management of resident (logical) pages.
*
* A small structure is kept for each resident
* page, indexed by page number. Each structure
* is an element of several lists:
*
* A hash table bucket used to quickly
* perform object/offset lookups
*
* A list of all pages for a given object,
* so they can be quickly deactivated at
* time of deallocation.
*
* An ordered list of pages due for pageout.
*
* In addition, the structure contains the object
* and offset to which this page belongs (for pageout),
* and sundry status bits.
*
* In general, operations on this structure's mutable fields are
* synchronized using either one of or a combination of the lock on the
* object that the page belongs to (O), the pool lock for the page (P),
* or the lock for either the free or paging queue (Q). If a field is
* annotated below with two of these locks, then holding either lock is
* sufficient for read access, but both locks are required for write
* access.
*
* In contrast, the synchronization of accesses to the page's
* dirty field is machine dependent (M). In the
* machine-independent layer, the lock on the object that the
* page belongs to must be held in order to operate on the field.
* However, the pmap layer is permitted to set all bits within
* the field without holding that lock. If the underlying
* architecture does not support atomic read-modify-write
* operations on the field's type, then the machine-independent
* layer uses a 32-bit atomic on the aligned 32-bit word that
* contains the dirty field. In the machine-independent layer,
* the implementation of read-modify-write operations on the
* field is encapsulated in vm_page_clear_dirty_mask().
*/
#if PAGE_SIZE == 4096
#define VM_PAGE_BITS_ALL 0xffu
typedef uint8_t vm_page_bits_t;
#elif PAGE_SIZE == 8192
#define VM_PAGE_BITS_ALL 0xffffu
typedef uint16_t vm_page_bits_t;
#elif PAGE_SIZE == 16384
#define VM_PAGE_BITS_ALL 0xffffffffu
typedef uint32_t vm_page_bits_t;
#elif PAGE_SIZE == 32768
#define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
typedef uint64_t vm_page_bits_t;
#endif
struct vm_page {
TAILQ_ENTRY(vm_page) pageq; /* page queue or free list (Q) */
TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
struct vm_page *left; /* splay tree link (O) */
struct vm_page *right; /* splay tree link (O) */
vm_object_t object; /* which object am I in (O,P)*/
vm_pindex_t pindex; /* offset into object (O,P) */
vm_paddr_t phys_addr; /* physical address of page */
struct md_page md; /* machine dependant stuff */
uint8_t queue; /* page queue index (P,Q) */
int8_t segind;
short hold_count; /* page hold count (P) */
uint8_t order; /* index of the buddy queue */
uint8_t pool;
u_short cow; /* page cow mapping count (P) */
u_int wire_count; /* wired down maps refs (P) */
uint8_t aflags; /* access is atomic */
uint8_t oflags; /* page VPO_* flags (O) */
uint16_t flags; /* page PG_* flags (P) */
u_char act_count; /* page usage count (O) */
u_char busy; /* page busy count (O) */
/* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
/* so, on normal X86 kernels, they must be at least 8 bits wide */
vm_page_bits_t valid; /* map of valid DEV_BSIZE chunks (O) */
vm_page_bits_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
};
/*
* Page flags stored in oflags:
*
* Access to these page flags is synchronized by the lock on the object
* containing the page (O).
*
* Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
* indicates that the page is not under PV management but
* otherwise should be treated as a normal page. Pages not
* under PV management cannot be paged out via the
* object/vm_page_t because there is no knowledge of their pte
* mappings, and such pages are also not on any PQ queue.
*
*/
#define VPO_BUSY 0x01 /* page is in transit */
#define VPO_WANTED 0x02 /* someone is waiting for page */
#define VPO_UNMANAGED 0x04 /* no PV management for page */
#define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */
#define VPO_NOSYNC 0x10 /* do not collect for syncer */
#define PQ_NONE 255
#define PQ_INACTIVE 0
#define PQ_ACTIVE 1
#define PQ_COUNT 2
TAILQ_HEAD(pglist, vm_page);
struct vm_pagequeue {
struct mtx pq_mutex;
struct pglist pq_pl;
int *const pq_cnt;
const char *const pq_name;
} __aligned(CACHE_LINE_SIZE);
extern struct vm_pagequeue vm_pagequeues[PQ_COUNT];
#define vm_pagequeue_assert_locked(pq) mtx_assert(&(pq)->pq_mutex, MA_OWNED)
#define vm_pagequeue_init_lock(pq) mtx_init(&(pq)->pq_mutex, \
(pq)->pq_name, "vm pagequeue", MTX_DEF | MTX_DUPOK);
#define vm_pagequeue_lock(pq) mtx_lock(&(pq)->pq_mutex)
#define vm_pagequeue_unlock(pq) mtx_unlock(&(pq)->pq_mutex)
extern struct mtx_padalign vm_page_queue_free_mtx;
extern struct mtx_padalign pa_lock[];
#if defined(__arm__)
#define PDRSHIFT PDR_SHIFT
#elif !defined(PDRSHIFT)
#define PDRSHIFT 21
#endif
#define pa_index(pa) ((pa) >> PDRSHIFT)
#define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT]))
#define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
#define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
#define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
#define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
#define PA_UNLOCK_COND(pa) \
do { \
if ((pa) != 0) { \
PA_UNLOCK((pa)); \
(pa) = 0; \
} \
} while (0)
#define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
#ifdef KLD_MODULE
#define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
#define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
#define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
#if defined(INVARIANTS)
#define vm_page_lock_assert(m, a) \
vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__)
#else
#define vm_page_lock_assert(m, a)
#endif
#else /* !KLD_MODULE */
#define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
#define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
#define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
#define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
#define vm_page_lock_assert(m, a) mtx_assert(vm_page_lockptr((m)), (a))
#endif
/*
* The vm_page's aflags are updated using atomic operations. To set or clear
* these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear()
* must be used. Neither these flags nor these functions are part of the KBI.
*
* PGA_REFERENCED may be cleared only if the object containing the page is
* locked. It is set by both the MI and MD VM layers. However, kernel
* loadable modules should not directly set this flag. They should call
* vm_page_reference() instead.
*
* PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). When it
* does so, the page must be VPO_BUSY. The MI VM layer must never access this
* flag directly. Instead, it should call pmap_page_is_write_mapped().
*
* PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has
* at least one executable mapping. It is not consumed by the MI VM layer.
*/
#define PGA_WRITEABLE 0x01 /* page may be mapped writeable */
#define PGA_REFERENCED 0x02 /* page has been referenced */
#define PGA_EXECUTABLE 0x04 /* page may be mapped executable */
/*
* Page flags. If changed at any other time than page allocation or
* freeing, the modification must be protected by the vm_page lock.
*/
#define PG_CACHED 0x0001 /* page is cached */
#define PG_FREE 0x0002 /* page is free */
#define PG_FICTITIOUS 0x0004 /* physical page doesn't exist */
#define PG_ZERO 0x0008 /* page is zeroed */
#define PG_MARKER 0x0010 /* special queue marker page */
#define PG_SLAB 0x0020 /* object pointer is actually a slab */
#define PG_WINATCFLS 0x0040 /* flush dirty page on inactive q */
#define PG_NODUMP 0x0080 /* don't include this page in a dump */
#define PG_UNHOLDFREE 0x0100 /* delayed free of a held page */
/*
* Misc constants.
*/
#define ACT_DECLINE 1
#define ACT_ADVANCE 3
#define ACT_INIT 5
#define ACT_MAX 64
#ifdef _KERNEL
#include <sys/systm.h>
#include <machine/atomic.h>
/*
* Each pageable resident page falls into one of four lists:
*
* free
* Available for allocation now.
*
* cache
* Almost available for allocation. Still associated with
* an object, but clean and immediately freeable.
*
* The following lists are LRU sorted:
*
* inactive
* Low activity, candidates for reclamation.
* This is the list of pages that should be
* paged out next.
*
* active
* Pages that are "active" i.e. they have been
* recently referenced.
*
*/
extern int vm_page_zero_count;
extern vm_page_t vm_page_array; /* First resident page in table */
extern long vm_page_array_size; /* number of vm_page_t's */
extern long first_page; /* first physical page number */
#define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0)
#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
/* page allocation classes: */
#define VM_ALLOC_NORMAL 0
#define VM_ALLOC_INTERRUPT 1
#define VM_ALLOC_SYSTEM 2
#define VM_ALLOC_CLASS_MASK 3
/* page allocation flags: */
#define VM_ALLOC_WIRED 0x0020 /* non pageable */
#define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */
#define VM_ALLOC_RETRY 0x0080 /* Mandatory with vm_page_grab() */
#define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
#define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
#define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */
#define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */
#define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */
#define VM_ALLOC_NODUMP 0x2000 /* don't include in dump */
#define VM_ALLOC_COUNT_SHIFT 16
#define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT)
#ifdef M_NOWAIT
static inline int
malloc2vm_flags(int malloc_flags)
{
int pflags;
KASSERT((malloc_flags & M_USE_RESERVE) == 0 ||
(malloc_flags & M_NOWAIT) != 0,
("M_USE_RESERVE requires M_NOWAIT"));
pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT :
VM_ALLOC_SYSTEM;
if ((malloc_flags & M_ZERO) != 0)
pflags |= VM_ALLOC_ZERO;
if ((malloc_flags & M_NODUMP) != 0)
pflags |= VM_ALLOC_NODUMP;
return (pflags);
}
#endif
void vm_page_busy(vm_page_t m);
void vm_page_flash(vm_page_t m);
void vm_page_io_start(vm_page_t m);
void vm_page_io_finish(vm_page_t m);
void vm_page_hold(vm_page_t mem);
void vm_page_unhold(vm_page_t mem);
void vm_page_free(vm_page_t m);
void vm_page_free_zero(vm_page_t m);
void vm_page_wakeup(vm_page_t m);
void vm_page_activate (vm_page_t);
vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
vm_paddr_t boundary, vm_memattr_t memattr);
vm_page_t vm_page_alloc_freelist(int, int);
vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
void vm_page_cache(vm_page_t);
void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t);
void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t);
int vm_page_try_to_cache (vm_page_t);
int vm_page_try_to_free (vm_page_t);
void vm_page_dontneed(vm_page_t);
void vm_page_deactivate (vm_page_t);
void vm_page_dequeue(vm_page_t m);
void vm_page_dequeue_locked(vm_page_t m);
vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
boolean_t vm_page_is_cached(vm_object_t object, vm_pindex_t pindex);
vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
vm_page_t vm_page_next(vm_page_t m);
int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *);
vm_page_t vm_page_prev(vm_page_t m);
void vm_page_putfake(vm_page_t m);
void vm_page_readahead_finish(vm_page_t m);
void vm_page_reference(vm_page_t m);
void vm_page_remove (vm_page_t);
void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
void vm_page_requeue(vm_page_t m);
void vm_page_requeue_locked(vm_page_t m);
void vm_page_set_valid_range(vm_page_t m, int base, int size);
void vm_page_sleep(vm_page_t m, const char *msg);
vm_page_t vm_page_splay(vm_pindex_t, vm_page_t);
vm_offset_t vm_page_startup(vm_offset_t vaddr);
void vm_page_unhold_pages(vm_page_t *ma, int count);
void vm_page_unwire (vm_page_t, int);
void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_wire (vm_page_t);
void vm_page_set_validclean (vm_page_t, int, int);
void vm_page_clear_dirty (vm_page_t, int, int);
void vm_page_set_invalid (vm_page_t, int, int);
int vm_page_is_valid (vm_page_t, int, int);
void vm_page_test_dirty (vm_page_t);
vm_page_bits_t vm_page_bits(int base, int size);
void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
void vm_page_free_toq(vm_page_t m);
void vm_page_zero_idle_wakeup(void);
void vm_page_cowfault (vm_page_t);
int vm_page_cowsetup(vm_page_t);
void vm_page_cowclear (vm_page_t);
void vm_page_dirty_KBI(vm_page_t m);
void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
#endif
#ifdef INVARIANTS
void vm_page_object_lock_assert(vm_page_t m);
#define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m)
#else
#define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0
#endif
/*
* We want to use atomic updates for the aflags field, which is 8 bits wide.
* However, not all architectures support atomic operations on 8-bit
* destinations. In order that we can easily use a 32-bit operation, we
* require that the aflags field be 32-bit aligned.
*/
CTASSERT(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0);
/*
* Clear the given bits in the specified page.
*/
static inline void
vm_page_aflag_clear(vm_page_t m, uint8_t bits)
{
uint32_t *addr, val;
/*
* The PGA_REFERENCED flag can only be cleared if the object
* containing the page is locked.
*/
if ((bits & PGA_REFERENCED) != 0)
VM_PAGE_OBJECT_LOCK_ASSERT(m);
/*
* Access the whole 32-bit word containing the aflags field with an
* atomic update. Parallel non-atomic updates to the other fields
* within this word are handled properly by the atomic update.
*/
addr = (void *)&m->aflags;
KASSERT(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0,
("vm_page_aflag_clear: aflags is misaligned"));
val = bits;
#if BYTE_ORDER == BIG_ENDIAN
val <<= 24;
#endif
atomic_clear_32(addr, val);
}
/*
* Set the given bits in the specified page.
*/
static inline void
vm_page_aflag_set(vm_page_t m, uint8_t bits)
{
uint32_t *addr, val;
/*
* The PGA_WRITEABLE flag can only be set if the page is managed and
* VPO_BUSY. Currently, this flag is only set by pmap_enter().
*/
KASSERT((bits & PGA_WRITEABLE) == 0 ||
(m->oflags & (VPO_UNMANAGED | VPO_BUSY)) == VPO_BUSY,
("vm_page_aflag_set: PGA_WRITEABLE and !VPO_BUSY"));
/*
* Access the whole 32-bit word containing the aflags field with an
* atomic update. Parallel non-atomic updates to the other fields
* within this word are handled properly by the atomic update.
*/
addr = (void *)&m->aflags;
KASSERT(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0,
("vm_page_aflag_set: aflags is misaligned"));
val = bits;
#if BYTE_ORDER == BIG_ENDIAN
val <<= 24;
#endif
atomic_set_32(addr, val);
}
/*
* vm_page_dirty:
*
* Set all bits in the page's dirty field.
*
* The object containing the specified page must be locked if the
* call is made from the machine-independent layer.
*
* See vm_page_clear_dirty_mask().
*/
static __inline void
vm_page_dirty(vm_page_t m)
{
/* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */
#if defined(KLD_MODULE) || defined(INVARIANTS)
vm_page_dirty_KBI(m);
#else
m->dirty = VM_PAGE_BITS_ALL;
#endif
}
/*
* vm_page_remque:
*
* If the given page is in a page queue, then remove it from that page
* queue.
*
* The page must be locked.
*/
static inline void
vm_page_remque(vm_page_t m)
{
if (m->queue != PQ_NONE)
vm_page_dequeue(m);
}
/*
* vm_page_sleep_if_busy:
*
* Sleep and release the page queues lock if VPO_BUSY is set or,
* if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the
* thread slept and the page queues lock was released.
* Otherwise, retains the page queues lock and returns FALSE.
*
* The object containing the given page must be locked.
*/
static __inline int
vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg)
{
if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) {
vm_page_sleep(m, msg);
return (TRUE);
}
return (FALSE);
}
/*
* vm_page_undirty:
*
* Set page to not be dirty. Note: does not clear pmap modify bits
*/
static __inline void
vm_page_undirty(vm_page_t m)
{
VM_PAGE_OBJECT_LOCK_ASSERT(m);
m->dirty = 0;
}
#endif /* _KERNEL */
#endif /* !_VM_PAGE_ */
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