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
11struct kmem_cache;
12
13typedef void * (mempool_alloc_t)(gfp_t gfp_mask, void *pool_data);
14typedef void (mempool_free_t)(void *element, void *pool_data);
15
16typedef 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
28static inline bool mempool_initialized(mempool_t *pool)
29{
30 return pool->elements != NULL;
31}
32
33static inline bool mempool_is_saturated(mempool_t *pool)
34{
35 return READ_ONCE(pool->curr_nr) >= pool->min_nr;
36}
37
38void mempool_exit(mempool_t *pool);
39int 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);
42int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
43 mempool_free_t *free_fn, void *pool_data);
44
45extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
46 mempool_free_t *free_fn, void *pool_data);
47extern 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
51extern int mempool_resize(mempool_t *pool, int new_min_nr);
52extern void mempool_destroy(mempool_t *pool);
53extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc;
54extern 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 */
61void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
62void mempool_free_slab(void *element, void *pool_data);
63
64static inline int
65mempool_init_slab_pool(mempool_t *pool, int min_nr, struct kmem_cache *kc)
66{
67 return mempool_init(pool, min_nr, alloc_fn: mempool_alloc_slab,
68 free_fn: mempool_free_slab, pool_data: (void *) kc);
69}
70
71static inline mempool_t *
72mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
73{
74 return mempool_create(min_nr, alloc_fn: mempool_alloc_slab, free_fn: mempool_free_slab,
75 pool_data: (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 */
82void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
83void mempool_kfree(void *element, void *pool_data);
84
85static inline int mempool_init_kmalloc_pool(mempool_t *pool, int min_nr, size_t size)
86{
87 return mempool_init(pool, min_nr, alloc_fn: mempool_kmalloc,
88 free_fn: mempool_kfree, pool_data: (void *) size);
89}
90
91static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
92{
93 return mempool_create(min_nr, alloc_fn: mempool_kmalloc, free_fn: mempool_kfree,
94 pool_data: (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 */
101void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
102void mempool_free_pages(void *element, void *pool_data);
103
104static inline int mempool_init_page_pool(mempool_t *pool, int min_nr, int order)
105{
106 return mempool_init(pool, min_nr, alloc_fn: mempool_alloc_pages,
107 free_fn: mempool_free_pages, pool_data: (void *)(long)order);
108}
109
110static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
111{
112 return mempool_create(min_nr, alloc_fn: mempool_alloc_pages, free_fn: mempool_free_pages,
113 pool_data: (void *)(long)order);
114}
115
116#endif /* _LINUX_MEMPOOL_H */
117

source code of linux/include/linux/mempool.h