xref: /linux/include/linux/mempool.h (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
1 /*
2  * memory buffer pool support
3  */
4 #ifndef _LINUX_MEMPOOL_H
5 #define _LINUX_MEMPOOL_H
6 
7 #include <linux/wait.h>
8 #include <linux/compiler.h>
9 
10 struct kmem_cache;
11 
12 typedef void * (mempool_alloc_t)(gfp_t gfp_mask, void *pool_data);
13 typedef void (mempool_free_t)(void *element, void *pool_data);
14 
15 typedef struct mempool_s {
16 	spinlock_t lock;
17 	int min_nr;		/* nr of elements at *elements */
18 	int curr_nr;		/* Current nr of elements at *elements */
19 	void **elements;
20 
21 	void *pool_data;
22 	mempool_alloc_t *alloc;
23 	mempool_free_t *free;
24 	wait_queue_head_t wait;
25 } mempool_t;
26 
27 extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
28 			mempool_free_t *free_fn, void *pool_data);
29 extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
30 			mempool_free_t *free_fn, void *pool_data,
31 			gfp_t gfp_mask, int nid);
32 
33 extern int mempool_resize(mempool_t *pool, int new_min_nr);
34 extern void mempool_destroy(mempool_t *pool);
35 extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc;
36 extern void mempool_free(void *element, mempool_t *pool);
37 
38 /*
39  * A mempool_alloc_t and mempool_free_t that get the memory from
40  * a slab cache that is passed in through pool_data.
41  * Note: the slab cache may not have a ctor function.
42  */
43 void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
44 void mempool_free_slab(void *element, void *pool_data);
45 static inline mempool_t *
46 mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
47 {
48 	return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab,
49 			      (void *) kc);
50 }
51 
52 /*
53  * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
54  * amount of memory specified by pool_data
55  */
56 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
57 void mempool_kfree(void *element, void *pool_data);
58 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
59 {
60 	return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
61 			      (void *) size);
62 }
63 
64 /*
65  * A mempool_alloc_t and mempool_free_t for a simple page allocator that
66  * allocates pages of the order specified by pool_data
67  */
68 void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
69 void mempool_free_pages(void *element, void *pool_data);
70 static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
71 {
72 	return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages,
73 			      (void *)(long)order);
74 }
75 
76 #endif /* _LINUX_MEMPOOL_H */
77