* Copyright (c) 1985, Avadis Tevanian, Jr., Michael Wayne Young
* Copyright (c) 1987 Carnegie-Mellon University
* Copyright (c) 1991 Regents of the University of California.
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
* The CMU software License Agreement specifies the terms and conditions
* for use and redistribution.
* @(#)vm_page.h 7.1 (Berkeley) %G%
* Resident memory system definitions.
#include "../vm/vm_param.h"
#include "../vm/vm_object.h"
#include "../vm/vm_prot.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
* 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.
* Fields in this structure are locked either by the lock on the
* object that the page belongs to (O) or by the lock on the page
queue_chain_t pageq
; /* queue info for FIFO
* queue or free list (P) */
queue_chain_t hashq
; /* hash table links (O)*/
queue_chain_t listq
; /* all pages in same object (O)*/
vm_object_t object
; /* which object am I in (O,P)*/
vm_offset_t offset
; /* offset into that object (O,P) */
unsigned int wire_count
:16, /* how many wired down maps use me?
/* boolean_t */ inactive
:1, /* page is in inactive list (P) */
active
:1, /* page is in active list (P) */
laundry
:1, /* page is being cleaned now (P)*/
pagerowned
:1, /* async paging op in progress */
ptpage
:1, /* is a user page table page */
:0; /* (force to 'long' boundary) */
int pad
; /* extra space for ns32000 bit ops */
boolean_t clean
; /* page has not been modified */
/* boolean_t */ busy
:1, /* page is in transit (O) */
wanted
:1, /* someone is waiting for page (O) */
tabled
:1, /* page is in VP table (O) */
copy_on_write
:1,/* page must be copied before being
fictitious
:1, /* physical page doesn't exist (O) */
absent
:1, /* virtual page doesn't exist (O) */
fake
:1, /* page is a placeholder for page-in
vm_offset_t phys_addr
; /* physical address of page */
vm_prot_t page_lock
; /* Uses prohibited by data manager */
vm_prot_t unlock_request
; /* Outstanding unlock request */
typedef struct vm_page
*vm_page_t
;
#define VM_PAGE_NULL ((vm_page_t) 0)
#define VM_PAGE_CHECK(mem) { \
if ( (((unsigned int) mem) < ((unsigned int) &vm_page_array[0])) || \
(((unsigned int) mem) > ((unsigned int) &vm_page_array[last_page-first_page])) || \
(mem->active && mem->inactive) \
) panic("vm_page_check: not valid!"); \
#define VM_PAGE_CHECK(mem)
* Each pageable resident page falls into one of three lists:
* Available for allocation now.
* Not referenced in any map, but still has an
* object/offset-page mapping, and may be dirty.
* This is the list of pages that should be
* A list of pages which have been placed in
* at least one physical map. This list is
* ordered, in LRU-like fashion.
queue_head_t vm_page_queue_free
; /* memory free queue */
queue_head_t vm_page_queue_active
; /* active memory queue */
queue_head_t vm_page_queue_inactive
; /* inactive memory queue */
vm_page_t vm_page_array
; /* First resident page in table */
long first_page
; /* first physical page number */
/* ... represented in vm_page_array */
long last_page
; /* last physical page number */
/* ... represented in vm_page_array */
vm_offset_t first_phys_addr
; /* physical address for first_page */
vm_offset_t last_phys_addr
; /* physical address for last_page */
int vm_page_free_count
; /* How many pages are free? */
int vm_page_active_count
; /* How many pages are active? */
int vm_page_inactive_count
; /* How many pages are inactive? */
int vm_page_wire_count
; /* How many pages are wired? */
int vm_page_free_target
; /* How many do we want free? */
int vm_page_free_min
; /* When to wakeup pageout */
int vm_page_inactive_target
;/* How many do we want inactive? */
int vm_page_free_reserved
; /* How many pages reserved to do pageout */
int vm_page_laundry_count
; /* How many pages being laundered? */
#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
#define IS_VM_PHYSADDR(pa) \
((pa) >= first_phys_addr && (pa) <= last_phys_addr)
#define PHYS_TO_VM_PAGE(pa) \
(&vm_page_array[atop(pa) - first_page ])
simple_lock_data_t vm_page_queue_lock
; /* lock on active and inactive
simple_lock_data_t vm_page_queue_free_lock
;
/* lock on free page queue */
vm_offset_t
vm_page_startup();
vm_page_t
vm_page_lookup();
vm_page_t
vm_page_alloc();
void vm_page_deactivate();
boolean_t
vm_page_zero_fill();
* Functions implemented as macros
#define PAGE_ASSERT_WAIT(m, interruptible) { \
assert_wait((int) (m), (interruptible)); \
#define PAGE_WAKEUP(m) { \
thread_wakeup((int) (m)); \
#define vm_page_lock_queues() simple_lock(&vm_page_queue_lock)
#define vm_page_unlock_queues() simple_unlock(&vm_page_queue_lock)
#define vm_page_set_modified(m) { (m)->clean = FALSE; }