vm_pager.h revision 1541 
1/*
2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	@(#)vm_pager.h	8.4 (Berkeley) 1/12/94
39 */
40
41/*
42 * Pager routine interface definition.
43 * For BSD we use a cleaner version of the internal pager interface.
44 */
45
46#ifndef	_VM_PAGER_
47#define	_VM_PAGER_
48
49TAILQ_HEAD(pagerlst, pager_struct);
50
51struct	pager_struct {
52	TAILQ_ENTRY(pager_struct) pg_list;	/* links for list management */
53	caddr_t			  pg_handle;	/* ext. handle (vp, dev, fp) */
54	int			  pg_type;	/* type of pager */
55	int			  pg_flags;	/* flags */
56	struct pagerops		  *pg_ops;	/* pager operations */
57	void			  *pg_data;	/* private pager data */
58};
59
60/* pager types */
61#define PG_DFLT		-1
62#define	PG_SWAP		0
63#define	PG_VNODE	1
64#define PG_DEVICE	2
65
66/* flags */
67#define PG_CLUSTERGET	1
68#define PG_CLUSTERPUT	2
69
70struct	pagerops {
71	void		(*pgo_init)		/* Initialize pager. */
72			    __P((void));
73	vm_pager_t	(*pgo_alloc)		/* Allocate pager. */
74			    __P((caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
75	void		(*pgo_dealloc)		/* Disassociate. */
76			    __P((vm_pager_t));
77	int		(*pgo_getpages)		/* Get (read) page. */
78			    __P((vm_pager_t, vm_page_t *, int, boolean_t));
79	int		(*pgo_putpages)		/* Put (write) page. */
80			    __P((vm_pager_t, vm_page_t *, int, boolean_t));
81	boolean_t  	(*pgo_haspage)		/* Does pager have page? */
82			    __P((vm_pager_t, vm_offset_t));
83	void		(*pgo_cluster)		/* Return range of cluster. */
84			    __P((vm_pager_t, vm_offset_t,
85				 vm_offset_t *, vm_offset_t *));
86};
87
88/*
89 * get/put return values
90 * OK	 operation was successful
91 * BAD	 specified data was out of the accepted range
92 * FAIL	 specified data was in range, but doesn't exist
93 * PEND	 operations was initiated but not completed
94 * ERROR error while accessing data that is in range and exists
95 * AGAIN temporary resource shortage prevented operation from happening
96 */
97#define	VM_PAGER_OK	0
98#define	VM_PAGER_BAD	1
99#define	VM_PAGER_FAIL	2
100#define	VM_PAGER_PEND	3
101#define	VM_PAGER_ERROR	4
102#define VM_PAGER_AGAIN	5
103
104#ifdef KERNEL
105extern struct pagerops *dfltpagerops;
106
107vm_pager_t	 vm_pager_allocate
108		    __P((int, caddr_t, vm_size_t, vm_prot_t, vm_offset_t));
109vm_page_t	 vm_pager_atop __P((vm_offset_t));
110void		 vm_pager_cluster
111		    __P((vm_pager_t, vm_offset_t,
112			 vm_offset_t *, vm_offset_t *));
113void		 vm_pager_clusternull
114		    __P((vm_pager_t, vm_offset_t,
115			 vm_offset_t *, vm_offset_t *));
116void		 vm_pager_deallocate __P((vm_pager_t));
117int		 vm_pager_get_pages
118		    __P((vm_pager_t, vm_page_t *, int, boolean_t));
119boolean_t	 vm_pager_has_page __P((vm_pager_t, vm_offset_t));
120void		 vm_pager_init __P((void));
121vm_pager_t	 vm_pager_lookup __P((struct pagerlst *, caddr_t));
122vm_offset_t	 vm_pager_map_pages __P((vm_page_t *, int, boolean_t));
123int		 vm_pager_put_pages
124		    __P((vm_pager_t, vm_page_t *, int, boolean_t));
125void		 vm_pager_sync __P((void));
126void		 vm_pager_unmap_pages __P((vm_offset_t, int));
127
128#define vm_pager_cancluster(p, b)	((p)->pg_flags & (b))
129
130/*
131 * XXX compat with old interface
132 */
133#define vm_pager_get(p, m, s) \
134({ \
135	vm_page_t ml[1]; \
136	ml[0] = (m); \
137	vm_pager_get_pages(p, ml, 1, s); \
138})
139#define vm_pager_put(p, m, s) \
140({ \
141	vm_page_t ml[1]; \
142	ml[0] = (m); \
143	vm_pager_put_pages(p, ml, 1, s); \
144})
145#endif
146
147#endif	/* _VM_PAGER_ */
148