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1 | /* |
2 | * zpool memory storage api | |
3 | * | |
4 | * Copyright (C) 2014 Dan Streetman | |
5 | * | |
6 | * This is a common frontend for the zbud and zsmalloc memory | |
7 | * storage pool implementations. Typically, this is used to | |
8 | * store compressed memory. | |
9 | */ | |
10 | ||
11 | #ifndef _ZPOOL_H_ | |
12 | #define _ZPOOL_H_ | |
13 | ||
14 | struct zpool; | |
15 | ||
16 | struct zpool_ops { | |
17 | int (*evict)(struct zpool *pool, unsigned long handle); | |
18 | }; | |
19 | ||
20 | /* | |
21 | * Control how a handle is mapped. It will be ignored if the | |
22 | * implementation does not support it. Its use is optional. | |
23 | * Note that this does not refer to memory protection, it | |
24 | * refers to how the memory will be copied in/out if copying | |
25 | * is necessary during mapping; read-write is the safest as | |
26 | * it copies the existing memory in on map, and copies the | |
27 | * changed memory back out on unmap. Write-only does not copy | |
28 | * in the memory and should only be used for initialization. | |
29 | * If in doubt, use ZPOOL_MM_DEFAULT which is read-write. | |
30 | */ | |
31 | enum zpool_mapmode { | |
32 | ZPOOL_MM_RW, /* normal read-write mapping */ | |
33 | ZPOOL_MM_RO, /* read-only (no copy-out at unmap time) */ | |
34 | ZPOOL_MM_WO, /* write-only (no copy-in at map time) */ | |
35 | ||
36 | ZPOOL_MM_DEFAULT = ZPOOL_MM_RW | |
37 | }; | |
38 | ||
3eba0c6a GM |
39 | struct zpool *zpool_create_pool(char *type, char *name, |
40 | gfp_t gfp, struct zpool_ops *ops); | |
af8d417a DS |
41 | |
42 | char *zpool_get_type(struct zpool *pool); | |
43 | ||
44 | void zpool_destroy_pool(struct zpool *pool); | |
45 | ||
46 | int zpool_malloc(struct zpool *pool, size_t size, gfp_t gfp, | |
47 | unsigned long *handle); | |
48 | ||
49 | void zpool_free(struct zpool *pool, unsigned long handle); | |
50 | ||
51 | int zpool_shrink(struct zpool *pool, unsigned int pages, | |
52 | unsigned int *reclaimed); | |
53 | ||
54 | void *zpool_map_handle(struct zpool *pool, unsigned long handle, | |
55 | enum zpool_mapmode mm); | |
56 | ||
57 | void zpool_unmap_handle(struct zpool *pool, unsigned long handle); | |
58 | ||
59 | u64 zpool_get_total_size(struct zpool *pool); | |
60 | ||
61 | ||
62 | /** | |
63 | * struct zpool_driver - driver implementation for zpool | |
64 | * @type: name of the driver. | |
65 | * @list: entry in the list of zpool drivers. | |
66 | * @create: create a new pool. | |
67 | * @destroy: destroy a pool. | |
68 | * @malloc: allocate mem from a pool. | |
69 | * @free: free mem from a pool. | |
70 | * @shrink: shrink the pool. | |
71 | * @map: map a handle. | |
72 | * @unmap: unmap a handle. | |
73 | * @total_size: get total size of a pool. | |
74 | * | |
75 | * This is created by a zpool implementation and registered | |
76 | * with zpool. | |
77 | */ | |
78 | struct zpool_driver { | |
79 | char *type; | |
80 | struct module *owner; | |
81 | atomic_t refcount; | |
82 | struct list_head list; | |
83 | ||
3eba0c6a | 84 | void *(*create)(char *name, gfp_t gfp, struct zpool_ops *ops); |
af8d417a DS |
85 | void (*destroy)(void *pool); |
86 | ||
87 | int (*malloc)(void *pool, size_t size, gfp_t gfp, | |
88 | unsigned long *handle); | |
89 | void (*free)(void *pool, unsigned long handle); | |
90 | ||
91 | int (*shrink)(void *pool, unsigned int pages, | |
92 | unsigned int *reclaimed); | |
93 | ||
94 | void *(*map)(void *pool, unsigned long handle, | |
95 | enum zpool_mapmode mm); | |
96 | void (*unmap)(void *pool, unsigned long handle); | |
97 | ||
98 | u64 (*total_size)(void *pool); | |
99 | }; | |
100 | ||
101 | void zpool_register_driver(struct zpool_driver *driver); | |
102 | ||
103 | int zpool_unregister_driver(struct zpool_driver *driver); | |
104 | ||
105 | int zpool_evict(void *pool, unsigned long handle); | |
106 | ||
107 | #endif |