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Dan Streetmanaf8d4172014-08-06 16:08:36 -07001/*
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
14struct zpool;
15
16struct 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 */
31enum 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
Dan Streetman3f0e1312015-09-09 15:35:16 -070039bool zpool_has_pool(char *type);
40
Ganesh Mahendran3eba0c62015-02-12 15:00:51 -080041struct zpool *zpool_create_pool(char *type, char *name,
Krzysztof Kozlowski78672772015-09-08 15:05:03 -070042 gfp_t gfp, const struct zpool_ops *ops);
Dan Streetmanaf8d4172014-08-06 16:08:36 -070043
44char *zpool_get_type(struct zpool *pool);
45
46void zpool_destroy_pool(struct zpool *pool);
47
48int zpool_malloc(struct zpool *pool, size_t size, gfp_t gfp,
49 unsigned long *handle);
50
51void zpool_free(struct zpool *pool, unsigned long handle);
52
53int zpool_shrink(struct zpool *pool, unsigned int pages,
54 unsigned int *reclaimed);
55
56void *zpool_map_handle(struct zpool *pool, unsigned long handle,
57 enum zpool_mapmode mm);
58
59void zpool_unmap_handle(struct zpool *pool, unsigned long handle);
60
61u64 zpool_get_total_size(struct zpool *pool);
62
63
64/**
65 * struct zpool_driver - driver implementation for zpool
66 * @type: name of the driver.
67 * @list: entry in the list of zpool drivers.
68 * @create: create a new pool.
69 * @destroy: destroy a pool.
70 * @malloc: allocate mem from a pool.
71 * @free: free mem from a pool.
72 * @shrink: shrink the pool.
73 * @map: map a handle.
74 * @unmap: unmap a handle.
75 * @total_size: get total size of a pool.
76 *
77 * This is created by a zpool implementation and registered
78 * with zpool.
79 */
80struct zpool_driver {
81 char *type;
82 struct module *owner;
83 atomic_t refcount;
84 struct list_head list;
85
Krzysztof Kozlowski78672772015-09-08 15:05:03 -070086 void *(*create)(char *name, gfp_t gfp, const struct zpool_ops *ops,
Dan Streetman479305f2015-06-25 15:00:40 -070087 struct zpool *zpool);
Dan Streetmanaf8d4172014-08-06 16:08:36 -070088 void (*destroy)(void *pool);
89
90 int (*malloc)(void *pool, size_t size, gfp_t gfp,
91 unsigned long *handle);
92 void (*free)(void *pool, unsigned long handle);
93
94 int (*shrink)(void *pool, unsigned int pages,
95 unsigned int *reclaimed);
96
97 void *(*map)(void *pool, unsigned long handle,
98 enum zpool_mapmode mm);
99 void (*unmap)(void *pool, unsigned long handle);
100
101 u64 (*total_size)(void *pool);
102};
103
104void zpool_register_driver(struct zpool_driver *driver);
105
106int zpool_unregister_driver(struct zpool_driver *driver);
107
Dan Streetmanaf8d4172014-08-06 16:08:36 -0700108#endif