2 * Copyright (c) 1995, David Greenman
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by David Greenman.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
39 #include <sys/resourcevar.h>
40 #include <sys/rwlock.h>
43 #include <vm/vm_object.h>
44 #include <vm/vm_page.h>
45 #include <vm/vm_pager.h>
46 #include <vm/swap_pager.h>
48 static vm_object_t default_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
49 vm_ooffset_t, struct ucred *);
50 static void default_pager_dealloc(vm_object_t);
51 static int default_pager_getpages(vm_object_t, vm_page_t *, int,
53 static void default_pager_putpages(vm_object_t, vm_page_t *, int,
55 static boolean_t default_pager_haspage(vm_object_t, vm_pindex_t, int *,
59 * pagerops for OBJT_DEFAULT - "default pager".
61 struct pagerops defaultpagerops = {
62 .pgo_alloc = default_pager_alloc,
63 .pgo_dealloc = default_pager_dealloc,
64 .pgo_getpages = default_pager_getpages,
65 .pgo_putpages = default_pager_putpages,
66 .pgo_haspage = default_pager_haspage,
70 * Return an initialized object.
73 default_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
74 vm_ooffset_t offset, struct ucred *cred)
79 panic("default_pager_alloc: handle specified");
81 if (!swap_reserve_by_cred(size, cred))
85 object = vm_object_allocate(OBJT_DEFAULT,
86 OFF_TO_IDX(round_page(offset + size)));
89 object->charge = size;
95 * Deallocate resources associated with the object.
98 default_pager_dealloc(vm_object_t object)
101 /* Reserved swap is released by vm_object_destroy(). */
102 object->type = OBJT_DEAD;
106 * Load pages from backing store.
109 default_pager_getpages(vm_object_t object, vm_page_t *m, int count,
110 int *rbehind, int *rahead)
114 * Since an OBJT_DEFAULT object is converted to OBJT_SWAP by the first
115 * call to the putpages method, this function will never be called on
116 * a vm_page with assigned swap.
118 return (VM_PAGER_FAIL);
122 * Store pages to backing store.
125 default_pager_putpages(vm_object_t object, vm_page_t *m, int count,
126 int flags, int *rtvals)
129 /* The swap pager will convert the object to OBJT_SWAP. */
130 swappagerops.pgo_putpages(object, m, count, flags, rtvals);
134 * Tell us whether the requested (object,index) is available from the object's
138 default_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
142 /* An OBJT_DEFAULT object has no backing store. */