include/linux/mempool.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * memory buffer pool support
0004  */
0005 #ifndef _LINUX_MEMPOOL_H
0006 #define _LINUX_MEMPOOL_H
0007
0008 #include <linux/wait.h>
0009 #include <linux/compiler.h>
0010
0011 struct kmem_cache;
0012
0013 typedef void * (mempool_alloc_t)(gfp_t gfp_mask, void *pool_data);
0014 typedef void (mempool_free_t)(void *element, void *pool_data);
0015
0016 typedef struct mempool_s {
0017     spinlock_t lock;
0018     int min_nr;     /* nr of elements at *elements */
0019     int curr_nr;        /* Current nr of elements at *elements */
0020     void **elements;
0021
0022     void *pool_data;
0023     mempool_alloc_t *alloc;
0024     mempool_free_t *free;
0025     wait_queue_head_t wait;
0026 } mempool_t;
0027
0028 static inline bool mempool_initialized(mempool_t *pool)
0029 {
0030     return pool->elements != NULL;
0031 }
0032
0033 void mempool_exit(mempool_t *pool);
0034 int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
0035               mempool_free_t *free_fn, void *pool_data,
0036               gfp_t gfp_mask, int node_id);
0037 int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
0038          mempool_free_t *free_fn, void *pool_data);
0039
0040 extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
0041             mempool_free_t *free_fn, void *pool_data);
0042 extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
0043             mempool_free_t *free_fn, void *pool_data,
0044             gfp_t gfp_mask, int nid);
0045
0046 extern int mempool_resize(mempool_t *pool, int new_min_nr);
0047 extern void mempool_destroy(mempool_t *pool);
0048 extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc;
0049 extern void mempool_free(void *element, mempool_t *pool);
0050
0051 /*
0052  * A mempool_alloc_t and mempool_free_t that get the memory from
0053  * a slab cache that is passed in through pool_data.
0054  * Note: the slab cache may not have a ctor function.
0055  */
0056 void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
0057 void mempool_free_slab(void *element, void *pool_data);
0058
0059 static inline int
0060 mempool_init_slab_pool(mempool_t *pool, int min_nr, struct kmem_cache *kc)
0061 {
0062     return mempool_init(pool, min_nr, mempool_alloc_slab,
0063                 mempool_free_slab, (void *) kc);
0064 }
0065
0066 static inline mempool_t *
0067 mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
0068 {
0069     return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab,
0070                   (void *) kc);
0071 }
0072
0073 /*
0074  * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
0075  * amount of memory specified by pool_data
0076  */
0077 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
0078 void mempool_kfree(void *element, void *pool_data);
0079
0080 static inline int mempool_init_kmalloc_pool(mempool_t *pool, int min_nr, size_t size)
0081 {
0082     return mempool_init(pool, min_nr, mempool_kmalloc,
0083                 mempool_kfree, (void *) size);
0084 }
0085
0086 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
0087 {
0088     return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
0089                   (void *) size);
0090 }
0091
0092 /*
0093  * A mempool_alloc_t and mempool_free_t for a simple page allocator that
0094  * allocates pages of the order specified by pool_data
0095  */
0096 void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
0097 void mempool_free_pages(void *element, void *pool_data);
0098
0099 static inline int mempool_init_page_pool(mempool_t *pool, int min_nr, int order)
0100 {
0101     return mempool_init(pool, min_nr, mempool_alloc_pages,
0102                 mempool_free_pages, (void *)(long)order);
0103 }
0104
0105 static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
0106 {
0107     return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages,
0108                   (void *)(long)order);
0109 }
0110
0111 #endif /* _LINUX_MEMPOOL_H */