1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Mach Operating System
30 * Copyright (c) 1987 Carnegie-Mellon University
31 * All rights reserved.  The CMU software License Agreement specifies
32 * the terms and conditions for use and redistribution.
33 */
34
35#ifndef	_VNODE_PAGER_
36#define	_VNODE_PAGER_	1
37
38#include <mach/kern_return.h>
39#include <sys/types.h>
40#include <kern/queue.h>
41
42#ifdef	KERNEL
43#include <mach/boolean.h>
44#include <mach/memory_object_types.h>
45#include <mach/vm_types.h>
46#include <vm/vm_protos.h>
47#include <vm/vm_pager.h>
48
49/*
50 *  Vstructs are the internal (to us) description of a unit of backing store.
51 *  The are the link between memory objects and the backing store they represent.
52 *  For the vnode pager, backing store comes in two flavors: normal files and
53 *  swap files.
54 *
55 *  For objects that page to and from normal files (e.g. objects that represent
56 *  program text segments), we maintain some simple parameters that allow us to
57 *  access the file's contents directly through the vnode interface.
58 *
59 *  Data for objects without associated vnodes is maintained in the swap files.
60 *  Each object that uses one of these as backing store has a vstruct indicating
61 *  the swap file of preference (vs_pf) and a mapping between contiguous object
62 *  offsets and swap file offsets (vs_pmap).  Each entry in this mapping specifies
63 *  the pager file to use, and the offset of the page in that pager file.  These
64 *  mapping entries are of type pfMapEntry.
65 */
66
67/*
68 * Pager file structure.  One per swap file.
69 */
70typedef struct pager_file {
71	queue_chain_t	pf_chain;	/* link to other paging files */
72	struct	vnode	*pf_vp;		/* vnode of paging file */
73	u_int		pf_count;	/* Number of vstruct using this file */
74	u_char		*pf_bmap; 	/* Map of used blocks */
75	long		pf_npgs;	/* Size of file in pages */
76	long		pf_pfree;	/* Number of unused pages */
77	long		pf_lowat;	/* Low water page */
78	long		pf_hipage;	/* Highest page allocated */
79	long		pf_hint;	/* Lowest page unallocated */
80	char		*pf_name;	/* Filename of this file */
81	boolean_t	pf_prefer;
82	int		pf_index;	/* index into the pager_file array */
83	void *		pf_lock;	/* Lock for alloc and dealloc */
84} *pager_file_t;
85
86#define	PAGER_FILE_NULL	(pager_file_t) 0
87
88#define	MAXPAGERFILES 16
89
90#define MAX_BACKING_STORE 100
91
92struct bs_map {
93	struct vnode    *vp;
94	void     	*bs;
95};
96extern struct bs_map  bs_port_table[];
97
98
99
100/*
101 * Pager file data structures.
102 */
103#define	INDEX_NULL	0
104typedef struct {
105	unsigned int index:8;	/* paging file this block is in */
106	unsigned int offset:24;	/* page number where block resides */
107} pf_entry;
108
109typedef enum {
110		IS_INODE,	/* Local disk */
111		IS_RNODE	/* NFS */
112	} vpager_fstype;
113
114/*
115 *  Basic vnode pager structure.  One per object, backing-store pair.
116 */
117typedef struct vstruct {
118	boolean_t	is_device;	/* Must be first - see vm_pager.h */
119	pager_file_t	vs_pf;		/* Pager file this uses */
120	pf_entry	**vs_pmap;	/* Map of pages into paging file */
121	unsigned int
122	/* boolean_t */	vs_swapfile:1;	/* vnode is a swapfile */
123	short		vs_count;	/* use count */
124	int		vs_size;	/* size of this chunk in pages*/
125	struct vnode	*vs_vp;		/* vnode to page to */
126} *vnode_pager_t;
127
128#define	VNODE_PAGER_NULL	((vnode_pager_t) 0)
129
130#endif	/* KERNEL */
131
132#endif	/* _VNODE_PAGER_ */
133