xref: /freebsd/sys/vm/vm_pager.h (revision 0c43d89a0d8e976ca494d4837f4c1f3734d2c300)
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  * $Id$
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 	int			  pg_flags;	/* flags */
58 	struct pagerops		  *pg_ops;	/* pager operations */
59 	void			  *pg_data;	/* private pager data */
60 };
61 
62 /* pager types */
63 #define PG_DFLT		-1
64 #define	PG_SWAP		0
65 #define	PG_VNODE	1
66 #define PG_DEVICE	2
67 
68 /* flags */
69 #define PG_CLUSTERGET	1
70 #define PG_CLUSTERPUT	2
71 
72 struct	pagerops {
73 	void		(*pgo_init)		/* Initialize pager. */
74 			    __P((void));
75 	vm_pager_t	(*pgo_alloc)		/* Allocate pager. */
76 			    __P((caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
77 	void		(*pgo_dealloc)		/* Disassociate. */
78 			    __P((vm_pager_t));
79 	int		(*pgo_getpage)
80 			    __P((vm_pager_t, vm_page_t, boolean_t));
81 	int		(*pgo_getpages)		/* Get (read) page. */
82 			    __P((vm_pager_t, vm_page_t *, int, int, boolean_t));
83 	int		(*pgo_putpage)
84 			    __P((vm_pager_t, vm_page_t, boolean_t));
85 	int		(*pgo_putpages)		/* Put (write) page. */
86 			    __P((vm_pager_t, vm_page_t *, int, boolean_t, int *));
87 	boolean_t  	(*pgo_haspage)		/* Does pager have page? */
88 			    __P((vm_pager_t, vm_offset_t));
89 };
90 
91 #define	VM_PAGER_ALLOC(h, s, p, o)		(*(pg)->pg_ops->pgo_alloc)(h, s, p, o)
92 #define	VM_PAGER_DEALLOC(pg)		(*(pg)->pg_ops->pgo_dealloc)(pg)
93 #define	VM_PAGER_GET(pg, m, s)		(*(pg)->pg_ops->pgo_getpage)(pg, m, s)
94 #define	VM_PAGER_GET_MULTI(pg, m, c, r, s)	(*(pg)->pg_ops->pgo_getpages)(pg, m, c, r, s)
95 #define	VM_PAGER_PUT(pg, m, s)		(*(pg)->pg_ops->pgo_putpage)(pg, m, s)
96 #define	VM_PAGER_PUT_MULTI(pg, m, c, s, rtval)		(*(pg)->pg_ops->pgo_putpages)(pg, m, c, s, rtval)
97 #define	VM_PAGER_HASPAGE(pg, o)		(*(pg)->pg_ops->pgo_haspage)(pg, o)
98 
99 /*
100  * get/put return values
101  * OK	 operation was successful
102  * BAD	 specified data was out of the accepted range
103  * FAIL	 specified data was in range, but doesn't exist
104  * PEND	 operations was initiated but not completed
105  * ERROR error while accessing data that is in range and exists
106  * AGAIN temporary resource shortage prevented operation from happening
107  */
108 #define	VM_PAGER_OK	0
109 #define	VM_PAGER_BAD	1
110 #define	VM_PAGER_FAIL	2
111 #define	VM_PAGER_PEND	3
112 #define	VM_PAGER_ERROR	4
113 #define VM_PAGER_AGAIN	5
114 
115 #ifdef KERNEL
116 extern struct pagerops *dfltpagerops;
117 
118 vm_pager_t	 vm_pager_allocate
119 		    __P((int, caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
120 vm_page_t	 vm_pager_atop __P((vm_offset_t));
121 void		 vm_pager_deallocate __P((vm_pager_t));
122 int		 vm_pager_get_pages
123 		    __P((vm_pager_t, vm_page_t *, int, int, boolean_t));
124 boolean_t	 vm_pager_has_page __P((vm_pager_t, vm_offset_t));
125 void		 vm_pager_init __P((void));
126 vm_pager_t	 vm_pager_lookup __P((struct pagerlst *, caddr_t));
127 vm_offset_t	 vm_pager_map_pages __P((vm_page_t *, int, boolean_t));
128 int		 vm_pager_put_pages
129 		    __P((vm_pager_t, vm_page_t *, int, boolean_t, int *));
130 void		 vm_pager_sync __P((void));
131 void		 vm_pager_unmap_pages __P((vm_offset_t, int));
132 
133 #define vm_pager_cancluster(p, b)	((p)->pg_flags & (b))
134 
135 /*
136  * XXX compat with old interface
137  */
138 #define vm_pager_get(p, m, s) \
139 ({ \
140 	vm_page_t ml[1]; \
141 	ml[0] = (m); \
142 	vm_pager_get_pages(p, ml, 1, 0, s); \
143 })
144 
145 #define vm_pager_put(p, m, s) \
146 ({ \
147 	int rtval; \
148 	vm_page_t ml[1]; \
149 	ml[0] = (m); \
150 	vm_pager_put_pages(p, ml, 1, s, &rtval); \
151 	rtval; \
152 })
153 #endif
154 
155 #endif	/* _VM_PAGER_ */
156