1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * zpool memory storage api |
4 | * |
5 | * Copyright (C) 2014 Dan Streetman |
6 | * |
7 | * This is a common frontend for the zbud and zsmalloc memory |
8 | * storage pool implementations. Typically, this is used to |
9 | * store compressed memory. |
10 | */ |
11 | |
12 | #ifndef _ZPOOL_H_ |
13 | #define _ZPOOL_H_ |
14 | |
15 | struct zpool; |
16 | |
17 | /* |
18 | * Control how a handle is mapped. It will be ignored if the |
19 | * implementation does not support it. Its use is optional. |
20 | * Note that this does not refer to memory protection, it |
21 | * refers to how the memory will be copied in/out if copying |
22 | * is necessary during mapping; read-write is the safest as |
23 | * it copies the existing memory in on map, and copies the |
24 | * changed memory back out on unmap. Write-only does not copy |
25 | * in the memory and should only be used for initialization. |
26 | * If in doubt, use ZPOOL_MM_DEFAULT which is read-write. |
27 | */ |
28 | enum zpool_mapmode { |
29 | ZPOOL_MM_RW, /* normal read-write mapping */ |
30 | ZPOOL_MM_RO, /* read-only (no copy-out at unmap time) */ |
31 | ZPOOL_MM_WO, /* write-only (no copy-in at map time) */ |
32 | |
33 | ZPOOL_MM_DEFAULT = ZPOOL_MM_RW |
34 | }; |
35 | |
36 | bool zpool_has_pool(char *type); |
37 | |
38 | struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp); |
39 | |
40 | const char *zpool_get_type(struct zpool *pool); |
41 | |
42 | void zpool_destroy_pool(struct zpool *pool); |
43 | |
44 | bool zpool_malloc_support_movable(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 | void *zpool_map_handle(struct zpool *pool, unsigned long handle, |
52 | enum zpool_mapmode mm); |
53 | |
54 | void zpool_unmap_handle(struct zpool *pool, unsigned long handle); |
55 | |
56 | u64 zpool_get_total_size(struct zpool *pool); |
57 | |
58 | |
59 | /** |
60 | * struct zpool_driver - driver implementation for zpool |
61 | * @type: name of the driver. |
62 | * @list: entry in the list of zpool drivers. |
63 | * @create: create a new pool. |
64 | * @destroy: destroy a pool. |
65 | * @malloc: allocate mem from a pool. |
66 | * @free: free mem from a pool. |
67 | * @sleep_mapped: whether zpool driver can sleep during map. |
68 | * @map: map a handle. |
69 | * @unmap: unmap a handle. |
70 | * @total_size: get total size of a pool. |
71 | * |
72 | * This is created by a zpool implementation and registered |
73 | * with zpool. |
74 | */ |
75 | struct zpool_driver { |
76 | char *type; |
77 | struct module *owner; |
78 | atomic_t refcount; |
79 | struct list_head list; |
80 | |
81 | void *(*create)(const char *name, gfp_t gfp); |
82 | void (*destroy)(void *pool); |
83 | |
84 | bool malloc_support_movable; |
85 | int (*malloc)(void *pool, size_t size, gfp_t gfp, |
86 | unsigned long *handle); |
87 | void (*free)(void *pool, unsigned long handle); |
88 | |
89 | bool sleep_mapped; |
90 | void *(*map)(void *pool, unsigned long handle, |
91 | enum zpool_mapmode mm); |
92 | void (*unmap)(void *pool, unsigned long handle); |
93 | |
94 | u64 (*total_size)(void *pool); |
95 | }; |
96 | |
97 | void zpool_register_driver(struct zpool_driver *driver); |
98 | |
99 | int zpool_unregister_driver(struct zpool_driver *driver); |
100 | |
101 | bool zpool_can_sleep_mapped(struct zpool *pool); |
102 | |
103 | #endif |
104 | |