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 
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
mempool_init_slab_pool(mempool_t * pool,int min_nr,struct kmem_cache * kc)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 *
mempool_create_slab_pool(int min_nr,struct kmem_cache * kc)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 
mempool_init_kmalloc_pool(mempool_t * pool,int min_nr,size_t size)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 
mempool_create_kmalloc_pool(int min_nr,size_t size)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 
mempool_init_page_pool(mempool_t * pool,int min_nr,int order)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 
mempool_create_page_pool(int min_nr,int order)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 */
112