xref: /freebsd/sys/vm/vm_pager.h (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
1 
2 /*
3  * Copyright (c) 1990 University of Utah.
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * the Systems Programming Group of the University of Utah Computer
9  * Science Department.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  *	@(#)vm_pager.h	8.4 (Berkeley) 1/12/94
40  * $Id: vm_pager.h,v 1.4 1994/10/09 01:52:17 phk Exp $
41  */
42 
43 /*
44  * Pager routine interface definition.
45  * For BSD we use a cleaner version of the internal pager interface.
46  */
47 
48 #ifndef	_VM_PAGER_
49 #define	_VM_PAGER_
50 
51 TAILQ_HEAD(pagerlst, pager_struct);
52 
53 struct pager_struct {
54 	TAILQ_ENTRY(pager_struct) pg_list;	/* links for list management */
55 	caddr_t pg_handle;		/* ext. handle (vp, dev, fp) */
56 	int pg_type;			/* type of pager */
57 	struct pagerops *pg_ops;	/* pager operations */
58 	void *pg_data;			/* private pager data */
59 };
60 
61 /* pager types */
62 #define PG_DFLT		-1
63 #define	PG_SWAP		0
64 #define	PG_VNODE	1
65 #define PG_DEVICE	2
66 
67 /* flags */
68 #define PG_CLUSTERGET	1
69 #define PG_CLUSTERPUT	2
70 
71 struct pagerops {
72 	void (*pgo_init) __P((void));		/* Initialize pager. */
73 	vm_pager_t(*pgo_alloc) __P((caddr_t, vm_size_t, vm_prot_t, vm_offset_t));	/* Allocate pager. */
74 	void (*pgo_dealloc) __P((vm_pager_t));	/* Disassociate. */
75 	int (*pgo_getpage) __P((vm_pager_t, vm_page_t, boolean_t));
76 	int (*pgo_getpages) __P((vm_pager_t, vm_page_t *, int, int, boolean_t));	/* Get (read) page. */
77 	int (*pgo_putpage) __P((vm_pager_t, vm_page_t, boolean_t));
78 	int (*pgo_putpages) __P((vm_pager_t, vm_page_t *, int, boolean_t, int *)); /* Put (write) page. */
79 	boolean_t(*pgo_haspage) __P((vm_pager_t, vm_offset_t)); /* Does pager have page? */
80 };
81 
82 #define	VM_PAGER_ALLOC(h, s, p, o)		(*(pg)->pg_ops->pgo_alloc)(h, s, p, o)
83 #define	VM_PAGER_DEALLOC(pg)		(*(pg)->pg_ops->pgo_dealloc)(pg)
84 #define	VM_PAGER_GET(pg, m, s)		(*(pg)->pg_ops->pgo_getpage)(pg, m, s)
85 #define	VM_PAGER_GET_MULTI(pg, m, c, r, s)	(*(pg)->pg_ops->pgo_getpages)(pg, m, c, r, s)
86 #define	VM_PAGER_PUT(pg, m, s)		(*(pg)->pg_ops->pgo_putpage)(pg, m, s)
87 #define	VM_PAGER_PUT_MULTI(pg, m, c, s, rtval)		(*(pg)->pg_ops->pgo_putpages)(pg, m, c, s, rtval)
88 #define	VM_PAGER_HASPAGE(pg, o)		(*(pg)->pg_ops->pgo_haspage)(pg, o)
89 
90 /*
91  * get/put return values
92  * OK	 operation was successful
93  * BAD	 specified data was out of the accepted range
94  * FAIL	 specified data was in range, but doesn't exist
95  * PEND	 operations was initiated but not completed
96  * ERROR error while accessing data that is in range and exists
97  * AGAIN temporary resource shortage prevented operation from happening
98  */
99 #define	VM_PAGER_OK	0
100 #define	VM_PAGER_BAD	1
101 #define	VM_PAGER_FAIL	2
102 #define	VM_PAGER_PEND	3
103 #define	VM_PAGER_ERROR	4
104 #define VM_PAGER_AGAIN	5
105 
106 #ifdef KERNEL
107 extern struct pagerops *dfltpagerops;
108 
109 vm_pager_t vm_pager_allocate __P((int, caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
110 vm_page_t vm_pager_atop __P((vm_offset_t));
111 void vm_pager_deallocate __P((vm_pager_t));
112 int vm_pager_get_pages __P((vm_pager_t, vm_page_t *, int, int, boolean_t));
113 boolean_t vm_pager_has_page __P((vm_pager_t, vm_offset_t));
114 void vm_pager_init __P((void));
115 vm_pager_t vm_pager_lookup __P((struct pagerlst *, caddr_t));
116 vm_offset_t vm_pager_map_pages __P((vm_page_t *, int, boolean_t));
117 vm_offset_t vm_pager_map_page __P((vm_page_t));
118 int vm_pager_put_pages __P((vm_pager_t, vm_page_t *, int, boolean_t, int *));
119 void vm_pager_sync __P((void));
120 void vm_pager_unmap_pages __P((vm_offset_t, int));
121 void vm_pager_unmap_page __P((vm_offset_t));
122 
123 /*
124  * XXX compat with old interface
125  */
126 #define vm_pager_get(p, m, s) \
127 ({ \
128 	vm_page_t ml[1]; \
129 	ml[0] = (m); \
130 	vm_pager_get_pages(p, ml, 1, 0, s); \
131 })
132 
133 #define vm_pager_put(p, m, s) \
134 ({ \
135 	int rtval; \
136 	vm_page_t ml[1]; \
137 	ml[0] = (m); \
138 	vm_pager_put_pages(p, ml, 1, s, &rtval); \
139 	rtval; \
140 })
141 #endif
142 
143 #endif				/* _VM_PAGER_ */
144