xnu-4570.71.2.tar.gz
[apple/xnu.git] / osfmk / mach / vm_purgable.h
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91447636 1/*
2d21ac55 2 * Copyright (c) 2003-2007 Apple Inc. All rights reserved.
91447636 3 *
2d21ac55 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
91447636 5 *
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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.
8f6c56a5 14 *
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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
8f6c56a5
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20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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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.
8f6c56a5 25 *
2d21ac55 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
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27 */
28
29/*
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30 * Virtual memory map purgeable object definitions.
31 * Objects that will be needed in the future (forward cached objects) should be queued LIFO.
32 * Objects that have been used and are cached for reuse (backward cached) should be queued FIFO.
33 * Every user of purgeable memory is entitled to using the highest volatile group (7).
34 * Only if a client wants some of its objects to definitely be purged earlier, it can put those in
35 * another group. This could be used to make all FIFO objects (in the lower group) go away before
36 * any LIFO objects (in the higher group) go away.
37 * Objects that should not get any chance to stay around can be marked as "obsolete". They will
38 * be emptied before any other objects or pages are reclaimed. Obsolete objects are not emptied
39 * in any particular order.
40 * 'purgeable' is recognized as the correct spelling. For historical reasons, definitions
41 * in this file are spelled 'purgable'.
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42 */
43
44#ifndef _MACH_VM_PURGABLE_H_
45#define _MACH_VM_PURGABLE_H_
46
47/*
48 * Types defined:
49 *
2d21ac55 50 * vm_purgable_t purgeable object control codes.
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51 */
52
53typedef int vm_purgable_t;
54
55/*
56 * Enumeration of valid values for vm_purgable_t.
57 */
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58#define VM_PURGABLE_SET_STATE ((vm_purgable_t) 0) /* set state of purgeable object */
59#define VM_PURGABLE_GET_STATE ((vm_purgable_t) 1) /* get state of purgeable object */
b0d623f7 60#define VM_PURGABLE_PURGE_ALL ((vm_purgable_t) 2) /* purge all volatile objects now */
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61#define VM_PURGABLE_SET_STATE_FROM_KERNEL ((vm_purgable_t) 3) /* set state from kernel */
62
63/*
64 * Purgeable state:
65 *
66 * 31 15 14 13 12 11 10 8 7 6 5 4 3 2 1 0
67 * +-----+--+-----+--+----+-+-+---+---+---+
68 * | |NA|DEBUG| | GRP| |B|ORD| |STA|
69 * +-----+--+-----+--+----+-+-+---+---+---+
70 * " ": unused (i.e. reserved)
71 * STA: purgeable state
72 * see: VM_PURGABLE_NONVOLATILE=0 to VM_PURGABLE_DENY=3
73 * ORD: order
74 * see:VM_VOLATILE_ORDER_*
75 * B: behavior
76 * see: VM_PURGABLE_BEHAVIOR_*
77 * GRP: group
78 * see: VM_VOLATILE_GROUP_*
79 * DEBUG: debug
80 * see: VM_PURGABLE_DEBUG_*
81 * NA: no aging
82 * see: VM_PURGABLE_NO_AGING*
83 */
b0d623f7 84
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85#define VM_PURGABLE_NO_AGING_SHIFT 16
86#define VM_PURGABLE_NO_AGING_MASK (0x1 << VM_PURGABLE_NO_AGING_SHIFT)
87#define VM_PURGABLE_NO_AGING (0x1 << VM_PURGABLE_NO_AGING_SHIFT)
88
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89#define VM_PURGABLE_DEBUG_SHIFT 12
90#define VM_PURGABLE_DEBUG_MASK (0x3 << VM_PURGABLE_DEBUG_SHIFT)
91#define VM_PURGABLE_DEBUG_EMPTY (0x1 << VM_PURGABLE_DEBUG_SHIFT)
92#define VM_PURGABLE_DEBUG_FAULT (0x2 << VM_PURGABLE_DEBUG_SHIFT)
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93
94/*
95 * Volatile memory ordering groups (group zero objects are purged before group 1, etc...
96 * It is implementation dependent as to whether these groups are global or per-address space.
97 * (for the moment, they are global).
98 */
99#define VM_VOLATILE_GROUP_SHIFT 8
100#define VM_VOLATILE_GROUP_MASK (7 << VM_VOLATILE_GROUP_SHIFT)
39236c6e 101#define VM_VOLATILE_GROUP_DEFAULT VM_VOLATILE_GROUP_0
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102
103#define VM_VOLATILE_GROUP_0 (0 << VM_VOLATILE_GROUP_SHIFT)
104#define VM_VOLATILE_GROUP_1 (1 << VM_VOLATILE_GROUP_SHIFT)
105#define VM_VOLATILE_GROUP_2 (2 << VM_VOLATILE_GROUP_SHIFT)
106#define VM_VOLATILE_GROUP_3 (3 << VM_VOLATILE_GROUP_SHIFT)
107#define VM_VOLATILE_GROUP_4 (4 << VM_VOLATILE_GROUP_SHIFT)
108#define VM_VOLATILE_GROUP_5 (5 << VM_VOLATILE_GROUP_SHIFT)
109#define VM_VOLATILE_GROUP_6 (6 << VM_VOLATILE_GROUP_SHIFT)
110#define VM_VOLATILE_GROUP_7 (7 << VM_VOLATILE_GROUP_SHIFT)
111
112/*
113 * Purgeable behavior
114 * Within the same group, FIFO objects will be emptied before objects that are added later.
115 * LIFO objects will be emptied after objects that are added later.
116 * - Input only, not returned on state queries.
117 */
118#define VM_PURGABLE_BEHAVIOR_SHIFT 6
119#define VM_PURGABLE_BEHAVIOR_MASK (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
120#define VM_PURGABLE_BEHAVIOR_FIFO (0 << VM_PURGABLE_BEHAVIOR_SHIFT)
121#define VM_PURGABLE_BEHAVIOR_LIFO (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
122
123/*
124 * Obsolete object.
125 * Disregard volatile group, and put object into obsolete queue instead, so it is the next object
126 * to be purged.
127 * - Input only, not returned on state queries.
128 */
129#define VM_PURGABLE_ORDERING_SHIFT 5
130#define VM_PURGABLE_ORDERING_MASK (1 << VM_PURGABLE_ORDERING_SHIFT)
131#define VM_PURGABLE_ORDERING_OBSOLETE (1 << VM_PURGABLE_ORDERING_SHIFT)
132#define VM_PURGABLE_ORDERING_NORMAL (0 << VM_PURGABLE_ORDERING_SHIFT)
133
134
135/*
136 * Obsolete parameter - do not use
137 */
138#define VM_VOLATILE_ORDER_SHIFT 4
139#define VM_VOLATILE_ORDER_MASK (1 << VM_VOLATILE_ORDER_SHIFT)
140#define VM_VOLATILE_MAKE_FIRST_IN_GROUP (1 << VM_VOLATILE_ORDER_SHIFT)
141#define VM_VOLATILE_MAKE_LAST_IN_GROUP (0 << VM_VOLATILE_ORDER_SHIFT)
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142
143/*
2d21ac55 144 * Valid states of a purgeable object.
91447636 145 */
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146#define VM_PURGABLE_STATE_MIN 0 /* minimum purgeable object state value */
147#define VM_PURGABLE_STATE_MAX 3 /* maximum purgeable object state value */
148#define VM_PURGABLE_STATE_MASK 3 /* mask to separate state from group */
91447636 149
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150#define VM_PURGABLE_NONVOLATILE 0 /* purgeable object is non-volatile */
151#define VM_PURGABLE_VOLATILE 1 /* purgeable object is volatile */
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152#define VM_PURGABLE_EMPTY 2 /* purgeable object is volatile and empty */
153#define VM_PURGABLE_DENY 3 /* (mark) object not purgeable */
91447636 154
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155#define VM_PURGABLE_ALL_MASKS (VM_PURGABLE_STATE_MASK | \
156 VM_VOLATILE_ORDER_MASK | \
157 VM_PURGABLE_ORDERING_MASK | \
158 VM_PURGABLE_BEHAVIOR_MASK | \
159 VM_VOLATILE_GROUP_MASK | \
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160 VM_PURGABLE_DEBUG_MASK | \
161 VM_PURGABLE_NO_AGING_MASK)
91447636 162#endif /* _MACH_VM_PURGABLE_H_ */