1/*
2 * Copyright (c) 2003-2007 Apple 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/*
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'.
42 */
43
44#ifndef	_MACH_VM_PURGABLE_H_
45#define	_MACH_VM_PURGABLE_H_
46
47/*
48 *	Types defined:
49 *
50 *	vm_purgable_t	purgeable object control codes.
51 */
52
53typedef int	vm_purgable_t;
54
55/*
56 *	Enumeration of valid values for vm_purgable_t.
57 */
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 */
60#define VM_PURGABLE_PURGE_ALL	((vm_purgable_t) 2)	/* purge all volatile objects now */
61
62#define VM_PURGABLE_NO_AGING_SHIFT	16
63#define VM_PURGABLE_NO_AGING_MASK	(0x1 << VM_PURGABLE_NO_AGING_SHIFT)
64#define VM_PURGABLE_NO_AGING 		(0x1 << VM_PURGABLE_NO_AGING_SHIFT)
65
66#define VM_PURGABLE_DEBUG_SHIFT	12
67#define VM_PURGABLE_DEBUG_MASK	(0x3 << VM_PURGABLE_DEBUG_SHIFT)
68#define VM_PURGABLE_DEBUG_EMPTY	(0x1 << VM_PURGABLE_DEBUG_SHIFT)
69#define VM_PURGABLE_DEBUG_FAULT	(0x2 << VM_PURGABLE_DEBUG_SHIFT)
70
71/*
72 * Volatile memory ordering groups (group zero objects are purged before group 1, etc...
73 * It is implementation dependent as to whether these groups are global or per-address space.
74 * (for the moment, they are global).
75 */
76#define VM_VOLATILE_GROUP_SHIFT		8
77#define VM_VOLATILE_GROUP_MASK		(7 << VM_VOLATILE_GROUP_SHIFT)
78#define VM_VOLATILE_GROUP_DEFAULT   VM_VOLATILE_GROUP_0
79
80#define VM_VOLATILE_GROUP_0			(0 << VM_VOLATILE_GROUP_SHIFT)
81#define VM_VOLATILE_GROUP_1			(1 << VM_VOLATILE_GROUP_SHIFT)
82#define VM_VOLATILE_GROUP_2			(2 << VM_VOLATILE_GROUP_SHIFT)
83#define VM_VOLATILE_GROUP_3			(3 << VM_VOLATILE_GROUP_SHIFT)
84#define VM_VOLATILE_GROUP_4			(4 << VM_VOLATILE_GROUP_SHIFT)
85#define VM_VOLATILE_GROUP_5			(5 << VM_VOLATILE_GROUP_SHIFT)
86#define VM_VOLATILE_GROUP_6			(6 << VM_VOLATILE_GROUP_SHIFT)
87#define VM_VOLATILE_GROUP_7			(7 << VM_VOLATILE_GROUP_SHIFT)
88
89/*
90 * Purgeable behavior
91 * Within the same group, FIFO objects will be emptied before objects that are added later.
92 * LIFO objects will be emptied after objects that are added later.
93 * - Input only, not returned on state queries.
94 */
95#define VM_PURGABLE_BEHAVIOR_SHIFT  6
96#define VM_PURGABLE_BEHAVIOR_MASK   (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
97#define VM_PURGABLE_BEHAVIOR_FIFO   (0 << VM_PURGABLE_BEHAVIOR_SHIFT)
98#define VM_PURGABLE_BEHAVIOR_LIFO   (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
99
100/*
101 * Obsolete object.
102 * Disregard volatile group, and put object into obsolete queue instead, so it is the next object
103 * to be purged.
104 * - Input only, not returned on state queries.
105 */
106#define VM_PURGABLE_ORDERING_SHIFT		5
107#define VM_PURGABLE_ORDERING_MASK		(1 << VM_PURGABLE_ORDERING_SHIFT)
108#define VM_PURGABLE_ORDERING_OBSOLETE	(1 << VM_PURGABLE_ORDERING_SHIFT)
109#define VM_PURGABLE_ORDERING_NORMAL		(0 << VM_PURGABLE_ORDERING_SHIFT)
110
111
112/*
113 * Obsolete parameter - do not use
114 */
115#define VM_VOLATILE_ORDER_SHIFT			4
116#define VM_VOLATILE_ORDER_MASK			(1 << VM_VOLATILE_ORDER_SHIFT)
117#define VM_VOLATILE_MAKE_FIRST_IN_GROUP	(1 << VM_VOLATILE_ORDER_SHIFT)
118#define VM_VOLATILE_MAKE_LAST_IN_GROUP	(0 << VM_VOLATILE_ORDER_SHIFT)
119
120/*
121 * Valid states of a purgeable object.
122 */
123#define VM_PURGABLE_STATE_MIN	0		/* minimum purgeable object state value */
124#define VM_PURGABLE_STATE_MAX	3		/* maximum purgeable object state value */
125#define VM_PURGABLE_STATE_MASK	3		/* mask to separate state from group */
126
127#define VM_PURGABLE_NONVOLATILE	0		/* purgeable object is non-volatile */
128#define VM_PURGABLE_VOLATILE	1		/* purgeable object is volatile */
129#define VM_PURGABLE_EMPTY	2		/* purgeable object is volatile and empty */
130#define VM_PURGABLE_DENY	3		/* (mark) object not purgeable */
131
132#define VM_PURGABLE_ALL_MASKS	(VM_PURGABLE_STATE_MASK | \
133				 VM_VOLATILE_ORDER_MASK | \
134				 VM_PURGABLE_ORDERING_MASK | \
135				 VM_PURGABLE_BEHAVIOR_MASK | \
136				 VM_VOLATILE_GROUP_MASK | \
137				 VM_PURGABLE_DEBUG_MASK | \
138				 VM_PURGABLE_NO_AGING_MASK)
139#endif	/* _MACH_VM_PURGABLE_H_ */
140