include/linux/mempool.h

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