xref: /linux/include/linux/mempool.h (revision 5ef12cb4a3a78ffb331c03a795a15eea4ae35155)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * memory buffer pool support
4  */
5 #ifndef _LINUX_MEMPOOL_H
6 #define _LINUX_MEMPOOL_H
7 
8 #include <linux/wait.h>
9 #include <linux/compiler.h>
10 
11 struct kmem_cache;
12 
13 typedef void * (mempool_alloc_t)(gfp_t gfp_mask, void *pool_data);
14 typedef void (mempool_free_t)(void *element, void *pool_data);
15 
16 typedef struct mempool_s {
17 	spinlock_t lock;
18 	int min_nr;		/* nr of elements at *elements */
19 	int curr_nr;		/* Current nr of elements at *elements */
20 	void **elements;
21 
22 	void *pool_data;
23 	mempool_alloc_t *alloc;
24 	mempool_free_t *free;
25 	wait_queue_head_t wait;
26 } mempool_t;
27 
28 extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
29 			mempool_free_t *free_fn, void *pool_data);
30 extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
31 			mempool_free_t *free_fn, void *pool_data,
32 			gfp_t gfp_mask, int nid);
33 
34 extern int mempool_resize(mempool_t *pool, int new_min_nr);
35 extern void mempool_destroy(mempool_t *pool);
36 extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc;
37 extern void mempool_free(void *element, mempool_t *pool);
38 
39 /*
40  * A mempool_alloc_t and mempool_free_t that get the memory from
41  * a slab cache that is passed in through pool_data.
42  * Note: the slab cache may not have a ctor function.
43  */
44 void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
45 void mempool_free_slab(void *element, void *pool_data);
46 static inline mempool_t *
47 mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
48 {
49 	return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab,
50 			      (void *) kc);
51 }
52 
53 /*
54  * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
55  * amount of memory specified by pool_data
56  */
57 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
58 void mempool_kfree(void *element, void *pool_data);
59 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
60 {
61 	return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
62 			      (void *) size);
63 }
64 
65 /*
66  * A mempool_alloc_t and mempool_free_t for a simple page allocator that
67  * allocates pages of the order specified by pool_data
68  */
69 void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
70 void mempool_free_pages(void *element, void *pool_data);
71 static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
72 {
73 	return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages,
74 			      (void *)(long)order);
75 }
76 
77 #endif /* _LINUX_MEMPOOL_H */
78