2 * Copyright (c) 2000 Peter Wemm
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * $FreeBSD: src/sys/vm/phys_pager.c,v 1.3.2.3 2000/12/17 02:05:41 alfred Exp $
26 * $DragonFly: src/sys/vm/phys_pager.c,v 1.4 2004/10/12 19:29:34 dillon Exp $
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/linker_set.h>
34 #include <sys/sysctl.h>
37 #include <vm/vm_object.h>
38 #include <vm/vm_page.h>
39 #include <vm/vm_pager.h>
40 #include <vm/vm_zone.h>
42 #include <sys/thread2.h>
44 /* list of device pager objects */
45 static struct pagerlst phys_pager_object_list
;
47 static int phys_pager_alloc_lock
, phys_pager_alloc_lock_want
;
53 TAILQ_INIT(&phys_pager_object_list
);
57 phys_pager_alloc(void *handle
, vm_ooffset_t size
, vm_prot_t prot
,
63 * Offset should be page aligned.
68 size
= round_page(size
);
72 * Lock to prevent object creation race condition.
74 while (phys_pager_alloc_lock
) {
75 phys_pager_alloc_lock_want
++;
76 tsleep(&phys_pager_alloc_lock
, 0, "ppall", 0);
77 phys_pager_alloc_lock_want
--;
79 phys_pager_alloc_lock
= 1;
82 * Look up pager, creating as necessary.
84 object
= vm_pager_object_lookup(&phys_pager_object_list
, handle
);
87 * Allocate object and associate it with the pager.
89 object
= vm_object_allocate(OBJT_PHYS
,
90 OFF_TO_IDX(foff
+ size
));
91 object
->handle
= handle
;
92 TAILQ_INSERT_TAIL(&phys_pager_object_list
, object
,
96 * Gain a reference to the object.
98 vm_object_reference(object
);
99 if (OFF_TO_IDX(foff
+ size
) > object
->size
)
100 object
->size
= OFF_TO_IDX(foff
+ size
);
102 phys_pager_alloc_lock
= 0;
103 if (phys_pager_alloc_lock_want
)
104 wakeup(&phys_pager_alloc_lock
);
106 object
= vm_object_allocate(OBJT_PHYS
,
107 OFF_TO_IDX(foff
+ size
));
114 phys_pager_dealloc(vm_object_t object
)
117 if (object
->handle
!= NULL
)
118 TAILQ_REMOVE(&phys_pager_object_list
, object
, pager_object_list
);
122 phys_pager_getpages(vm_object_t object
, vm_page_t
*m
, int count
, int reqpage
)
128 * Fill as many pages as vm_fault has allocated for us.
130 for (i
= 0; i
< count
; i
++) {
131 if ((m
[i
]->flags
& PG_ZERO
) == 0)
132 vm_page_zero_fill(m
[i
]);
133 vm_page_flag_set(m
[i
], PG_ZERO
);
134 /* Switch off pv_entries */
135 vm_page_unmanage(m
[i
]);
136 m
[i
]->valid
= VM_PAGE_BITS_ALL
;
138 /* The requested page must remain busy, the others not. */
140 vm_page_flag_clear(m
[i
], PG_BUSY
);
146 return (VM_PAGER_OK
);
150 phys_pager_putpages(vm_object_t object
, vm_page_t
*m
, int count
, boolean_t sync
,
154 panic("phys_pager_putpage called");
158 * Implement a pretty aggressive clustered getpages strategy. Hint that
159 * everything in an entire 4MB window should be prefaulted at once.
161 * XXX 4MB (1024 slots per page table page) is convenient for x86,
162 * but may not be for other arches.
165 #define PHYSCLUSTER 1024
168 phys_pager_haspage(vm_object_t object
, vm_pindex_t pindex
, int *before
,
171 vm_pindex_t base
, end
;
173 base
= pindex
& (~(PHYSCLUSTER
- 1));
174 end
= base
+ (PHYSCLUSTER
- 1);
176 *before
= pindex
- base
;
178 *after
= end
- pindex
;
182 struct pagerops physpagerops
= {