xref: /freebsd/sys/vm/swap_pager.h (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990 University of Utah.
5  * Copyright (c) 1991 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * the Systems Programming Group of the University of Utah Computer
10  * Science Department.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)swap_pager.h	7.1 (Berkeley) 12/5/90
37  * $FreeBSD$
38  */
39 
40 #ifndef	_VM_SWAP_PAGER_H_
41 #define	_VM_SWAP_PAGER_H_ 1
42 
43 typedef	int32_t	swblk_t;	/*
44 				 * swap offset.  This is the type used to
45 				 * address the "virtual swap device" and
46 				 * therefore the maximum swap space is
47 				 * 2^32 pages.
48 				 */
49 
50 struct buf;
51 struct swdevt;
52 typedef void sw_strategy_t(struct buf *, struct swdevt *);
53 typedef void sw_close_t(struct thread *, struct swdevt *);
54 
55 /*
56  * Swap device table
57  */
58 struct swdevt {
59 	int	sw_flags;
60 	int	sw_nblks;
61 	int     sw_used;
62 	dev_t	sw_dev;
63 	struct vnode *sw_vp;
64 	void	*sw_id;
65 	swblk_t	sw_first;
66 	swblk_t	sw_end;
67 	struct blist *sw_blist;
68 	TAILQ_ENTRY(swdevt)	sw_list;
69 	sw_strategy_t		*sw_strategy;
70 	sw_close_t		*sw_close;
71 };
72 
73 #define	SW_UNMAPPED	0x01
74 #define	SW_CLOSING	0x04
75 
76 #ifdef _KERNEL
77 
78 extern int swap_pager_avail;
79 
80 struct xswdev;
81 int swap_dev_info(int name, struct xswdev *xs, char *devname, size_t len);
82 void swap_pager_copy(vm_object_t, vm_object_t, vm_pindex_t, int);
83 vm_pindex_t swap_pager_find_least(vm_object_t object, vm_pindex_t pindex);
84 void swap_pager_freespace(vm_object_t, vm_pindex_t, vm_size_t);
85 void swap_pager_swap_init(void);
86 int swap_pager_nswapdev(void);
87 int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_size_t);
88 void swap_pager_status(int *total, int *used);
89 void swapoff_all(void);
90 
91 #endif				/* _KERNEL */
92 #endif				/* _VM_SWAP_PAGER_H_ */
93