xref: /xnu-11215.81.4/osfmk/mach/vm_purgable.h (revision d4514f0bc1d3f944c22d92e68b646ac3fb40d452)
1 /*
2  * Copyright (c) 2003-2007 Apple Inc. All rights reserved.
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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 
53 typedef int     vm_purgable_t;
54 
55 /*
56  *	Enumeration of valid values for vm_purgable_t.
57  *
58  *  When making a new VM_PURGABLE_*, update tests vm_parameter_validation_[user|kern]
59  *  and their expected results; they deliberately call VM functions with invalid
60  *  values and you may be turning one of those invalid bits valid.
61  */
62 #define VM_PURGABLE_SET_STATE   ((vm_purgable_t) 0)     /* set state of purgeable object */
63 #define VM_PURGABLE_GET_STATE   ((vm_purgable_t) 1)     /* get state of purgeable object */
64 #define VM_PURGABLE_PURGE_ALL   ((vm_purgable_t) 2)     /* purge all volatile objects now */
65 #define VM_PURGABLE_SET_STATE_FROM_KERNEL ((vm_purgable_t) 3) /* set state from kernel */
66 
67 /*
68  * Purgeable state:
69  *
70  *  31 15 14 13 12 11 10 8 7 6 5 4 3 2 1 0
71  * +-----+--+-----+--+----+-+-+---+---+---+
72  * |     |NA|DEBUG|  | GRP| |B|ORD|   |STA|
73  * +-----+--+-----+--+----+-+-+---+---+---+
74  * " ": unused (i.e. reserved)
75  * STA: purgeable state
76  *      see: VM_PURGABLE_NONVOLATILE=0 to VM_PURGABLE_DENY=3
77  * ORD: order
78  *      see:VM_VOLATILE_ORDER_*
79  * B: behavior
80  *      see: VM_PURGABLE_BEHAVIOR_*
81  * GRP: group
82  *      see: VM_VOLATILE_GROUP_*
83  * DEBUG: debug
84  *      see: VM_PURGABLE_DEBUG_*
85  * NA: no aging
86  *      see: VM_PURGABLE_NO_AGING*
87  */
88 
89 #define VM_PURGABLE_NO_AGING_SHIFT      16
90 #define VM_PURGABLE_NO_AGING_MASK       (0x1 << VM_PURGABLE_NO_AGING_SHIFT)
91 #define VM_PURGABLE_NO_AGING            (0x1 << VM_PURGABLE_NO_AGING_SHIFT)
92 
93 #define VM_PURGABLE_DEBUG_SHIFT 12
94 #define VM_PURGABLE_DEBUG_MASK  (0x3 << VM_PURGABLE_DEBUG_SHIFT)
95 #define VM_PURGABLE_DEBUG_EMPTY (0x1 << VM_PURGABLE_DEBUG_SHIFT)
96 #define VM_PURGABLE_DEBUG_FAULT (0x2 << VM_PURGABLE_DEBUG_SHIFT)
97 
98 /*
99  * Volatile memory ordering groups (group zero objects are purged before group 1, etc...
100  * It is implementation dependent as to whether these groups are global or per-address space.
101  * (for the moment, they are global).
102  */
103 #define VM_VOLATILE_GROUP_SHIFT         8
104 #define VM_VOLATILE_GROUP_MASK          (7 << VM_VOLATILE_GROUP_SHIFT)
105 #define VM_VOLATILE_GROUP_DEFAULT   VM_VOLATILE_GROUP_0
106 
107 #define VM_VOLATILE_GROUP_0                     (0 << VM_VOLATILE_GROUP_SHIFT)
108 #define VM_VOLATILE_GROUP_1                     (1 << VM_VOLATILE_GROUP_SHIFT)
109 #define VM_VOLATILE_GROUP_2                     (2 << VM_VOLATILE_GROUP_SHIFT)
110 #define VM_VOLATILE_GROUP_3                     (3 << VM_VOLATILE_GROUP_SHIFT)
111 #define VM_VOLATILE_GROUP_4                     (4 << VM_VOLATILE_GROUP_SHIFT)
112 #define VM_VOLATILE_GROUP_5                     (5 << VM_VOLATILE_GROUP_SHIFT)
113 #define VM_VOLATILE_GROUP_6                     (6 << VM_VOLATILE_GROUP_SHIFT)
114 #define VM_VOLATILE_GROUP_7                     (7 << VM_VOLATILE_GROUP_SHIFT)
115 
116 /*
117  * Purgeable behavior
118  * Within the same group, FIFO objects will be emptied before objects that are added later.
119  * LIFO objects will be emptied after objects that are added later.
120  * - Input only, not returned on state queries.
121  */
122 #define VM_PURGABLE_BEHAVIOR_SHIFT  6
123 #define VM_PURGABLE_BEHAVIOR_MASK   (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
124 #define VM_PURGABLE_BEHAVIOR_FIFO   (0 << VM_PURGABLE_BEHAVIOR_SHIFT)
125 #define VM_PURGABLE_BEHAVIOR_LIFO   (1 << VM_PURGABLE_BEHAVIOR_SHIFT)
126 
127 /*
128  * Obsolete object.
129  * Disregard volatile group, and put object into obsolete queue instead, so it is the next object
130  * to be purged.
131  * - Input only, not returned on state queries.
132  */
133 #define VM_PURGABLE_ORDERING_SHIFT              5
134 #define VM_PURGABLE_ORDERING_MASK               (1 << VM_PURGABLE_ORDERING_SHIFT)
135 #define VM_PURGABLE_ORDERING_OBSOLETE   (1 << VM_PURGABLE_ORDERING_SHIFT)
136 #define VM_PURGABLE_ORDERING_NORMAL             (0 << VM_PURGABLE_ORDERING_SHIFT)
137 
138 
139 /*
140  * Obsolete parameter - do not use
141  */
142 #define VM_VOLATILE_ORDER_SHIFT                 4
143 #define VM_VOLATILE_ORDER_MASK                  (1 << VM_VOLATILE_ORDER_SHIFT)
144 #define VM_VOLATILE_MAKE_FIRST_IN_GROUP (1 << VM_VOLATILE_ORDER_SHIFT)
145 #define VM_VOLATILE_MAKE_LAST_IN_GROUP  (0 << VM_VOLATILE_ORDER_SHIFT)
146 
147 /*
148  * Valid states of a purgeable object.
149  */
150 #define VM_PURGABLE_STATE_MIN   0               /* minimum purgeable object state value */
151 #define VM_PURGABLE_STATE_MAX   3               /* maximum purgeable object state value */
152 #define VM_PURGABLE_STATE_MASK  3               /* mask to separate state from group */
153 
154 #define VM_PURGABLE_NONVOLATILE 0               /* purgeable object is non-volatile */
155 #define VM_PURGABLE_VOLATILE    1               /* purgeable object is volatile */
156 #define VM_PURGABLE_EMPTY       2               /* purgeable object is volatile and empty */
157 #define VM_PURGABLE_DENY        3               /* (mark) object not purgeable */
158 
159 #define VM_PURGABLE_ALL_MASKS   (VM_PURGABLE_STATE_MASK | \
160 	                         VM_VOLATILE_ORDER_MASK | \
161 	                         VM_PURGABLE_ORDERING_MASK | \
162 	                         VM_PURGABLE_BEHAVIOR_MASK | \
163 	                         VM_VOLATILE_GROUP_MASK | \
164 	                         VM_PURGABLE_DEBUG_MASK | \
165 	                         VM_PURGABLE_NO_AGING_MASK)
166 #endif  /* _MACH_VM_PURGABLE_H_ */
167