summaryrefslogtreecommitdiffstats
path: root/sys/vm/vm_pager.h
blob: bb7a5ecd32dc996be05c199991694dcc107186a1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*-
 * Copyright (c) 1990 University of Utah.
 * 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 Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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.
 *
 *	@(#)vm_pager.h	8.4 (Berkeley) 1/12/94
 * $FreeBSD$
 */

/*
 * Pager routine interface definition.
 */

#ifndef	_VM_PAGER_
#define	_VM_PAGER_

#include <sys/queue.h>

TAILQ_HEAD(pagerlst, vm_object);

typedef void pgo_init_t(void);
typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
    struct ucred *);
typedef void pgo_dealloc_t(vm_object_t);
typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int);
typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
typedef void pgo_pageunswapped_t(vm_page_t);

struct pagerops {
	pgo_init_t	*pgo_init;		/* Initialize pager. */
	pgo_alloc_t	*pgo_alloc;		/* Allocate pager. */
	pgo_dealloc_t	*pgo_dealloc;		/* Disassociate. */
	pgo_getpages_t	*pgo_getpages;		/* Get (read) page. */
	pgo_putpages_t	*pgo_putpages;		/* Put (write) page. */
	pgo_haspage_t	*pgo_haspage;		/* Does pager have page? */
	pgo_pageunswapped_t *pgo_pageunswapped;
};

extern struct pagerops defaultpagerops;
extern struct pagerops swappagerops;
extern struct pagerops vnodepagerops;
extern struct pagerops devicepagerops;
extern struct pagerops physpagerops;
extern struct pagerops sgpagerops;
extern struct pagerops mgtdevicepagerops;

/*
 * get/put return values
 * OK	 operation was successful
 * BAD	 specified data was out of the accepted range
 * FAIL	 specified data was in range, but doesn't exist
 * PEND	 operations was initiated but not completed
 * ERROR error while accessing data that is in range and exists
 * AGAIN temporary resource shortage prevented operation from happening
 */
#define	VM_PAGER_OK	0
#define	VM_PAGER_BAD	1
#define	VM_PAGER_FAIL	2
#define	VM_PAGER_PEND	3
#define	VM_PAGER_ERROR	4
#define VM_PAGER_AGAIN	5

#define	VM_PAGER_PUT_SYNC		0x0001
#define	VM_PAGER_PUT_INVAL		0x0002
#define VM_PAGER_CLUSTER_OK		0x0008

#ifdef _KERNEL

extern vm_map_t pager_map;
extern struct pagerops *pagertab[];
extern struct mtx pbuf_mtx;

vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
    vm_ooffset_t, struct ucred *);
void vm_pager_bufferinit(void);
void vm_pager_deallocate(vm_object_t);
static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int);
static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
void vm_pager_init(void);
vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);

/*
 *	vm_page_get_pages:
 *
 *	Retrieve pages from the VM system in order to map them into an object
 *	( or into VM space somewhere ).  If the pagein was successful, we
 *	must fully validate it.
 */
static __inline int
vm_pager_get_pages(
	vm_object_t object,
	vm_page_t *m,
	int count,
	int reqpage
) {
	int r;

	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
	r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
	if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
		vm_page_zero_invalid(m[reqpage], TRUE);
	}
	return (r);
}

static __inline void
vm_pager_put_pages(
	vm_object_t object,
	vm_page_t *m,
	int count,
	int flags,
	int *rtvals
) {

	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
	(*pagertab[object->type]->pgo_putpages)
	    (object, m, count, flags, rtvals);
}

/*
 *	vm_pager_haspage
 *
 *	Check to see if an object's pager has the requested page.  The
 *	object's pager will also set before and after to give the caller
 *	some idea of the number of pages before and after the requested
 *	page can be I/O'd efficiently.
 *
 *	The object must be locked.
 */
static __inline boolean_t
vm_pager_has_page(
	vm_object_t object,
	vm_pindex_t offset, 
	int *before,
	int *after
) {
	boolean_t ret;

	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
	ret = (*pagertab[object->type]->pgo_haspage)
	    (object, offset, before, after);
	return (ret);
} 

/* 
 *      vm_pager_page_unswapped
 * 
 *	Destroy swap associated with the page.
 * 
 *	The object containing the page must be locked.
 *      This function may not block.
 *
 *	XXX: A much better name would be "vm_pager_page_dirtied()"
 *	XXX: It is not obvious if this could be profitably used by any
 *	XXX: pagers besides the swap_pager or if it should even be a
 *	XXX: generic pager_op in the first place.
 */
static __inline void
vm_pager_page_unswapped(vm_page_t m)
{

	VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
	if (pagertab[m->object->type]->pgo_pageunswapped)
		(*pagertab[m->object->type]->pgo_pageunswapped)(m);
}

struct cdev_pager_ops {
	int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
	    int prot, vm_page_t *mres);
	int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
	    vm_ooffset_t foff, struct ucred *cred, u_short *color);
	void (*cdev_pg_dtor)(void *handle);
};

vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
    struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
    vm_ooffset_t foff, struct ucred *cred);
vm_object_t cdev_pager_lookup(void *handle);
void cdev_pager_free_page(vm_object_t object, vm_page_t m);

#endif				/* _KERNEL */
#endif				/* _VM_PAGER_ */
OpenPOWER on IntegriCloud