Commit | Line | Data |
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f14f75b8 | 1 | /* |
7f184275 HY |
2 | * Basic general purpose allocator for managing special purpose |
3 | * memory, for example, memory that is not managed by the regular | |
4 | * kmalloc/kfree interface. Uses for this includes on-device special | |
5 | * memory, uncached memory etc. | |
6 | * | |
7 | * It is safe to use the allocator in NMI handlers and other special | |
8 | * unblockable contexts that could otherwise deadlock on locks. This | |
9 | * is implemented by using atomic operations and retries on any | |
10 | * conflicts. The disadvantage is that there may be livelocks in | |
11 | * extreme cases. For better scalability, one allocator can be used | |
12 | * for each CPU. | |
13 | * | |
14 | * The lockless operation only works if there is enough memory | |
15 | * available. If new memory is added to the pool a lock has to be | |
16 | * still taken. So any user relying on locklessness has to ensure | |
17 | * that sufficient memory is preallocated. | |
18 | * | |
19 | * The basic atomic operation of this allocator is cmpxchg on long. | |
20 | * On architectures that don't have NMI-safe cmpxchg implementation, | |
21 | * the allocator can NOT be used in NMI handler. So code uses the | |
22 | * allocator in NMI handler should depend on | |
23 | * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. | |
f14f75b8 | 24 | * |
f14f75b8 JS |
25 | * This source code is licensed under the GNU General Public License, |
26 | * Version 2. See the file COPYING for more details. | |
27 | */ | |
28 | ||
f14f75b8 | 29 | |
6aae6e03 JCPV |
30 | #ifndef __GENALLOC_H__ |
31 | #define __GENALLOC_H__ | |
ca279cf1 BG |
32 | /** |
33 | * Allocation callback function type definition | |
34 | * @map: Pointer to bitmap | |
35 | * @size: The bitmap size in bits | |
36 | * @start: The bitnumber to start searching at | |
37 | * @nr: The number of zeroed bits we're looking for | |
38 | * @data: optional additional data used by @genpool_algo_t | |
39 | */ | |
40 | typedef unsigned long (*genpool_algo_t)(unsigned long *map, | |
41 | unsigned long size, | |
42 | unsigned long start, | |
43 | unsigned int nr, | |
44 | void *data); | |
45 | ||
f14f75b8 | 46 | /* |
929f9727 | 47 | * General purpose special memory pool descriptor. |
f14f75b8 | 48 | */ |
929f9727 | 49 | struct gen_pool { |
7f184275 | 50 | spinlock_t lock; |
929f9727 DN |
51 | struct list_head chunks; /* list of chunks in this pool */ |
52 | int min_alloc_order; /* minimum allocation order */ | |
ca279cf1 BG |
53 | |
54 | genpool_algo_t algo; /* allocation function */ | |
55 | void *data; | |
f14f75b8 JS |
56 | }; |
57 | ||
58 | /* | |
929f9727 | 59 | * General purpose special memory pool chunk descriptor. |
f14f75b8 | 60 | */ |
929f9727 | 61 | struct gen_pool_chunk { |
929f9727 | 62 | struct list_head next_chunk; /* next chunk in pool */ |
7f184275 | 63 | atomic_t avail; |
3c8f370d | 64 | phys_addr_t phys_addr; /* physical starting address of memory chunk */ |
929f9727 DN |
65 | unsigned long start_addr; /* starting address of memory chunk */ |
66 | unsigned long end_addr; /* ending address of memory chunk */ | |
67 | unsigned long bits[0]; /* bitmap for allocating memory chunk */ | |
f14f75b8 JS |
68 | }; |
69 | ||
929f9727 | 70 | extern struct gen_pool *gen_pool_create(int, int); |
3c8f370d JCPV |
71 | extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long); |
72 | extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t, | |
73 | size_t, int); | |
74 | /** | |
75 | * gen_pool_add - add a new chunk of special memory to the pool | |
76 | * @pool: pool to add new memory chunk to | |
77 | * @addr: starting address of memory chunk to add to pool | |
78 | * @size: size in bytes of the memory chunk to add to pool | |
79 | * @nid: node id of the node the chunk structure and bitmap should be | |
80 | * allocated on, or -1 | |
81 | * | |
82 | * Add a new chunk of special memory to the specified pool. | |
83 | * | |
84 | * Returns 0 on success or a -ve errno on failure. | |
85 | */ | |
86 | static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr, | |
87 | size_t size, int nid) | |
88 | { | |
89 | return gen_pool_add_virt(pool, addr, -1, size, nid); | |
90 | } | |
322acc96 | 91 | extern void gen_pool_destroy(struct gen_pool *); |
929f9727 DN |
92 | extern unsigned long gen_pool_alloc(struct gen_pool *, size_t); |
93 | extern void gen_pool_free(struct gen_pool *, unsigned long, size_t); | |
7f184275 HY |
94 | extern void gen_pool_for_each_chunk(struct gen_pool *, |
95 | void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *); | |
96 | extern size_t gen_pool_avail(struct gen_pool *); | |
97 | extern size_t gen_pool_size(struct gen_pool *); | |
ca279cf1 BG |
98 | |
99 | extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, | |
100 | void *data); | |
101 | ||
102 | extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size, | |
103 | unsigned long start, unsigned int nr, void *data); | |
104 | ||
105 | extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size, | |
106 | unsigned long start, unsigned int nr, void *data); | |
107 | ||
6aae6e03 | 108 | #endif /* __GENALLOC_H__ */ |