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
mempool_initialized(mempool_t * pool)28 static inline bool mempool_initialized(mempool_t *pool)
29 {
30 return pool->elements != NULL;
31 }
32
mempool_is_saturated(mempool_t * pool)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
mempool_init_slab_pool(mempool_t * pool,int min_nr,struct kmem_cache * kc)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 *
mempool_create_slab_pool(int min_nr,struct kmem_cache * kc)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
mempool_init_kmalloc_pool(mempool_t * pool,int min_nr,size_t size)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
mempool_create_kmalloc_pool(int min_nr,size_t size)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
mempool_init_page_pool(mempool_t * pool,int min_nr,int order)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
mempool_create_page_pool(int min_nr,int order)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