xref: /linux/include/linux/mempool.h (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  * memory buffer pool support
3  */
4 #ifndef _LINUX_MEMPOOL_H
5 #define _LINUX_MEMPOOL_H
6 
7 #include <linux/wait.h>
8 
9 struct kmem_cache;
10 
11 typedef void * (mempool_alloc_t)(gfp_t gfp_mask, void *pool_data);
12 typedef void (mempool_free_t)(void *element, void *pool_data);
13 
14 typedef struct mempool_s {
15 	spinlock_t lock;
16 	int min_nr;		/* nr of elements at *elements */
17 	int curr_nr;		/* Current nr of elements at *elements */
18 	void **elements;
19 
20 	void *pool_data;
21 	mempool_alloc_t *alloc;
22 	mempool_free_t *free;
23 	wait_queue_head_t wait;
24 } mempool_t;
25 
26 extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
27 			mempool_free_t *free_fn, void *pool_data);
28 extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
29 			mempool_free_t *free_fn, void *pool_data,
30 			gfp_t gfp_mask, int nid);
31 
32 extern int mempool_resize(mempool_t *pool, int new_min_nr);
33 extern void mempool_destroy(mempool_t *pool);
34 extern void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask);
35 extern void mempool_free(void *element, mempool_t *pool);
36 
37 /*
38  * A mempool_alloc_t and mempool_free_t that get the memory from
39  * a slab cache that is passed in through pool_data.
40  * Note: the slab cache may not have a ctor function.
41  */
42 void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
43 void mempool_free_slab(void *element, void *pool_data);
44 static inline mempool_t *
45 mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
46 {
47 	return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab,
48 			      (void *) kc);
49 }
50 
51 /*
52  * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
53  * amount of memory specified by pool_data
54  */
55 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
56 void mempool_kfree(void *element, void *pool_data);
57 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
58 {
59 	return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
60 			      (void *) size);
61 }
62 
63 /*
64  * A mempool_alloc_t and mempool_free_t for a simple page allocator that
65  * allocates pages of the order specified by pool_data
66  */
67 void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
68 void mempool_free_pages(void *element, void *pool_data);
69 static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
70 {
71 	return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages,
72 			      (void *)(long)order);
73 }
74 
75 #endif /* _LINUX_MEMPOOL_H */
76