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 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 */