1/*
2 * Copyright (c) 2000 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 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56/*
57 */
58
59#ifndef	VM_VM_EXTERNAL_H_
60#define VM_VM_EXTERNAL_H_
61
62#include <mach/boolean.h>
63#include <mach/machine/vm_types.h>
64
65/*
66 *	External page management hint technology
67 *
68 *	The data structure exported by this module maintains
69 *	a (potentially incomplete) map of the pages written
70 *	to external storage for a range of virtual memory.
71 */
72
73typedef char	*vm_external_map_t;
74#define	VM_EXTERNAL_NULL	((char *) 0)
75
76/*
77 *	The states that may be recorded for a page of external storage.
78 */
79
80typedef int	vm_external_state_t;
81#define	VM_EXTERNAL_STATE_EXISTS		1
82#define	VM_EXTERNAL_STATE_UNKNOWN		2
83#define	VM_EXTERNAL_STATE_ABSENT		3
84
85/*
86 * Useful macros
87 */
88#define stob(s)	((atop_32((s)) + 07) >> 3)
89
90/*
91 *	Routines exported by this module.
92 */
93					/* Initialize the module */
94extern void			vm_external_module_initialize(void);
95
96
97extern vm_external_map_t	vm_external_create(
98					/* Create a vm_external_map_t */
99					vm_offset_t		size);
100
101extern void			vm_external_destroy(
102					/* Destroy one */
103					vm_external_map_t	map,
104					vm_size_t		size);
105
106extern vm_size_t		vm_external_map_size(
107					/* Return size of map in bytes */
108					vm_offset_t	size);
109
110extern void			vm_external_copy(
111					/* Copy one into another */
112					vm_external_map_t	old_map,
113					vm_size_t		old_size,
114					vm_external_map_t	new_map);
115
116extern void			vm_external_state_set(
117					/* Set state of a page to
118					 * VM_EXTERNAL_STATE_EXISTS */
119					vm_external_map_t	map,
120					vm_offset_t		offset);
121
122extern void			vm_external_state_clr(
123					/* clear page state
124					 */
125					vm_external_map_t	map,
126					vm_offset_t		offset);
127
128#define	vm_external_state_get(map, offset)			  	\
129			(((map) != VM_EXTERNAL_NULL) ? 			\
130			  _vm_external_state_get((map), (offset)) :	\
131			  VM_EXTERNAL_STATE_UNKNOWN)
132					/* Retrieve the state for a
133					 * given page, if known.  */
134
135extern vm_external_state_t	_vm_external_state_get(
136					/* HIDDEN routine */
137					vm_external_map_t	map,
138					vm_offset_t		offset);
139
140boolean_t			vm_external_within(
141					/* Check if new object size
142					 * fits in current map */
143					vm_size_t	new_size,
144					vm_size_t	old_size);
145#endif	/* VM_VM_EXTERNAL_H_ */
146