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1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
11 *
12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22/*
23 * @OSF_COPYRIGHT@
24 */
25/*
26 * Mach Operating System
27 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
28 * All Rights Reserved.
29 *
30 * Permission to use, copy, modify and distribute this software and its
31 * documentation is hereby granted, provided that both the copyright
32 * notice and this permission notice appear in all copies of the
33 * software, derivative works or modified versions, and any portions
34 * thereof, and that both notices appear in supporting documentation.
35 *
36 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
37 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
38 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
39 *
40 * Carnegie Mellon requests users of this software to return to
41 *
42 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
43 * School of Computer Science
44 * Carnegie Mellon University
45 * Pittsburgh PA 15213-3890
46 *
47 * any improvements or extensions that they make and grant Carnegie Mellon
48 * the rights to redistribute these changes.
49 */
50/*
51 */
52
53#ifndef VM_VM_EXTERNAL_H_
54#define VM_VM_EXTERNAL_H_
55
56#include <mach/boolean.h>
57#include <mach/machine/vm_types.h>
58
59/*
60 * External page management hint technology
61 *
62 * The data structure exported by this module maintains
63 * a (potentially incomplete) map of the pages written
64 * to external storage for a range of virtual memory.
65 */
66
67typedef char *vm_external_map_t;
68#define VM_EXTERNAL_NULL ((char *) 0)
69
70/*
71 * The states that may be recorded for a page of external storage.
72 */
73
74typedef int vm_external_state_t;
75#define VM_EXTERNAL_STATE_EXISTS 1
76#define VM_EXTERNAL_STATE_UNKNOWN 2
77#define VM_EXTERNAL_STATE_ABSENT 3
78
79/*
80 * Useful macros
81 */
82#define stob(s) ((atop((s)) + 07) >> 3)
83
84/*
85 * Routines exported by this module.
86 */
87 /* Initialize the module */
88extern void vm_external_module_initialize(void);
89
90
91extern vm_external_map_t vm_external_create(
92 /* Create a vm_external_map_t */
93 vm_offset_t size);
94
95extern void vm_external_destroy(
96 /* Destroy one */
97 vm_external_map_t map,
98 vm_size_t size);
99
100extern vm_size_t vm_external_map_size(
101 /* Return size of map in bytes */
102 vm_offset_t size);
103
104extern void vm_external_copy(
105 /* Copy one into another */
106 vm_external_map_t old_map,
107 vm_size_t old_size,
108 vm_external_map_t new_map);
109
110extern void vm_external_state_set(
111 /* Set state of a page to
112 * VM_EXTERNAL_STATE_EXISTS */
113 vm_external_map_t map,
114 vm_offset_t offset);
115
116extern void vm_external_state_clr(
117 /* clear page state
118 */
119 vm_external_map_t map,
120 vm_offset_t offset);
121
122#define vm_external_state_get(map, offset) \
123 (((map) != VM_EXTERNAL_NULL) ? \
124 _vm_external_state_get((map), (offset)) : \
125 VM_EXTERNAL_STATE_UNKNOWN)
126 /* Retrieve the state for a
127 * given page, if known. */
128
129extern vm_external_state_t _vm_external_state_get(
130 /* HIDDEN routine */
131 vm_external_map_t map,
132 vm_offset_t offset);
133
134boolean_t vm_external_within(
135 /* Check if new object size
136 * fits in current map */
137 vm_size_t new_size,
138 vm_size_t old_size);
139#endif /* VM_VM_EXTERNAL_H_ */