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_alloc_preallocated(mempool_t *pool) __malloc;
55 extern void mempool_free(void *element, mempool_t *pool);
56
57 /*
58 * A mempool_alloc_t and mempool_free_t that get the memory from
59 * a slab cache that is passed in through pool_data.
60 * Note: the slab cache may not have a ctor function.
61 */
62 void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
63 void mempool_free_slab(void *element, void *pool_data);
64
65 static inline int
mempool_init_slab_pool(mempool_t * pool,int min_nr,struct kmem_cache * kc)66 mempool_init_slab_pool(mempool_t *pool, int min_nr, struct kmem_cache *kc)
67 {
68 return mempool_init(pool, min_nr, mempool_alloc_slab,
69 mempool_free_slab, (void *) kc);
70 }
71
72 static inline mempool_t *
mempool_create_slab_pool(int min_nr,struct kmem_cache * kc)73 mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
74 {
75 return mempool_create(min_nr, mempool_alloc_slab, mempool_free_slab,
76 (void *) kc);
77 }
78
79 /*
80 * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
81 * amount of memory specified by pool_data
82 */
83 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
84 void mempool_kfree(void *element, void *pool_data);
85
mempool_init_kmalloc_pool(mempool_t * pool,int min_nr,size_t size)86 static inline int mempool_init_kmalloc_pool(mempool_t *pool, int min_nr, size_t size)
87 {
88 return mempool_init(pool, min_nr, mempool_kmalloc,
89 mempool_kfree, (void *) size);
90 }
91
mempool_create_kmalloc_pool(int min_nr,size_t size)92 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
93 {
94 return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
95 (void *) size);
96 }
97
98 /*
99 * A mempool_alloc_t and mempool_free_t for a simple page allocator that
100 * allocates pages of the order specified by pool_data
101 */
102 void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
103 void mempool_free_pages(void *element, void *pool_data);
104
mempool_init_page_pool(mempool_t * pool,int min_nr,int order)105 static inline int mempool_init_page_pool(mempool_t *pool, int min_nr, int order)
106 {
107 return mempool_init(pool, min_nr, mempool_alloc_pages,
108 mempool_free_pages, (void *)(long)order);
109 }
110
mempool_create_page_pool(int min_nr,int order)111 static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
112 {
113 return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages,
114 (void *)(long)order);
115 }
116
117 #endif /* _LINUX_MEMPOOL_H */
118