xref: /freebsd/sys/vm/swap_pager.h (revision 4b330699f819a81d8e34d471225143ffeb321855)
1 /*-
2  * Copyright (c) 1990 University of Utah.
3  * Copyright (c) 1991 The Regents of the University of California.
4  * 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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	from: @(#)swap_pager.h	7.1 (Berkeley) 12/5/90
35  * $FreeBSD$
36  */
37 
38 #ifndef	_VM_SWAP_PAGER_H_
39 #define	_VM_SWAP_PAGER_H_ 1
40 
41 typedef	int32_t	swblk_t;	/*
42 				 * swap offset.  This is the type used to
43 				 * address the "virtual swap device" and
44 				 * therefore the maximum swap space is
45 				 * 2^32 pages.
46 				 */
47 
48 struct buf;
49 struct swdevt;
50 typedef void sw_strategy_t(struct buf *, struct swdevt *);
51 typedef void sw_close_t(struct thread *, struct swdevt *);
52 
53 /*
54  * Swap device table
55  */
56 struct swdevt {
57 	int	sw_flags;
58 	int	sw_nblks;
59 	int     sw_used;
60 	dev_t	sw_dev;
61 	struct vnode *sw_vp;
62 	void	*sw_id;
63 	swblk_t	sw_first;
64 	swblk_t	sw_end;
65 	struct blist *sw_blist;
66 	TAILQ_ENTRY(swdevt)	sw_list;
67 	sw_strategy_t		*sw_strategy;
68 	sw_close_t		*sw_close;
69 };
70 
71 #define	SW_UNMAPPED	0x01
72 #define	SW_CLOSING	0x04
73 
74 #ifdef _KERNEL
75 
76 extern int swap_pager_full;
77 extern int swap_pager_avail;
78 
79 struct xswdev;
80 int swap_dev_info(int name, struct xswdev *xs, char *devname, size_t len);
81 void swap_pager_copy(vm_object_t, vm_object_t, vm_pindex_t, int);
82 vm_pindex_t swap_pager_find_least(vm_object_t object, vm_pindex_t pindex);
83 void swap_pager_freespace(vm_object_t, vm_pindex_t, vm_size_t);
84 void swap_pager_swap_init(void);
85 int swap_pager_nswapdev(void);
86 int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_size_t);
87 void swap_pager_status(int *total, int *used);
88 void swapoff_all(void);
89 
90 #endif				/* _KERNEL */
91 #endif				/* _VM_SWAP_PAGER_H_ */
92