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 static inline bool mempool_initialized(mempool_t *pool) 29 { 30 return pool->elements != NULL; 31 } 32 33 static inline bool mempool_is_saturated(mempool_t *pool) 34 { 35 return READ_ONCE(pool->curr_nr) >= pool->min_nr; 36 } 37 38 void mempool_exit(mempool_t *pool); 39 int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn, 40 mempool_free_t *free_fn, void *pool_data, 41 gfp_t gfp_mask, int node_id); 42 int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn, 43 mempool_free_t *free_fn, void *pool_data); 44 45 extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn, 46 mempool_free_t *free_fn, void *pool_data); 47 extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn, 48 mempool_free_t *free_fn, void *pool_data, 49 gfp_t gfp_mask, int nid); 50 51 extern int mempool_resize(mempool_t *pool, int new_min_nr); 52 extern void mempool_destroy(mempool_t *pool); 53 extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc; 54 extern void mempool_free(void *element, mempool_t *pool); 55 56 /* 57 * A mempool_alloc_t and mempool_free_t that get the memory from 58 * a slab cache that is passed in through pool_data. 59 * Note: the slab cache may not have a ctor function. 60 */ 61 void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data); 62 void mempool_free_slab(void *element, void *pool_data); 63 64 static inline int 65 mempool_init_slab_pool(mempool_t *pool, int min_nr, struct kmem_cache *kc) 66 { 67 return mempool_init(pool, min_nr, mempool_alloc_slab, 68 mempool_free_slab, (void *) kc); 69 } 70 71 static inline mempool_t * 72 mempool_create_slab_pool(int min_nr, struct kmem_cache *kc) 73 { 74 return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab, 75 (void *) kc); 76 } 77 78 /* 79 * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the 80 * amount of memory specified by pool_data 81 */ 82 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data); 83 void mempool_kfree(void *element, void *pool_data); 84 85 static inline int mempool_init_kmalloc_pool(mempool_t *pool, int min_nr, size_t size) 86 { 87 return mempool_init(pool, min_nr, mempool_kmalloc, 88 mempool_kfree, (void *) size); 89 } 90 91 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size) 92 { 93 return mempool_create(min_nr, mempool_kmalloc, mempool_kfree, 94 (void *) size); 95 } 96 97 /* 98 * A mempool_alloc_t and mempool_free_t for a simple page allocator that 99 * allocates pages of the order specified by pool_data 100 */ 101 void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data); 102 void mempool_free_pages(void *element, void *pool_data); 103 104 static inline int mempool_init_page_pool(mempool_t *pool, int min_nr, int order) 105 { 106 return mempool_init(pool, min_nr, mempool_alloc_pages, 107 mempool_free_pages, (void *)(long)order); 108 } 109 110 static inline mempool_t *mempool_create_page_pool(int min_nr, int order) 111 { 112 return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages, 113 (void *)(long)order); 114 } 115 116 #endif /* _LINUX_MEMPOOL_H */ 117