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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - lib/sg_pool.c
1 #include <linux/module.h>
2 #include <linux/scatterlist.h>
3 #include <linux/mempool.h>
4 #include <linux/slab.h>
6 #define SG_MEMPOOL_NR ARRAY_SIZE(sg_pools)
7 #define SG_MEMPOOL_SIZE 2
12 struct kmem_cache
*slab
;
16 #define SP(x) { .size = x, "sgpool-" __stringify(x) }
17 #if (SG_CHUNK_SIZE < 32)
18 #error SG_CHUNK_SIZE is too small (must be 32 or greater)
20 static struct sg_pool sg_pools
[] = {
23 #if (SG_CHUNK_SIZE > 32)
25 #if (SG_CHUNK_SIZE > 64)
27 #if (SG_CHUNK_SIZE > 128)
29 #if (SG_CHUNK_SIZE > 256)
30 #error SG_CHUNK_SIZE is too large (256 MAX)
39 static inline unsigned int sg_pool_index(unsigned short nents
)
43 BUG_ON(nents
> SG_CHUNK_SIZE
);
48 index
= get_count_order(nents
) - 3;
53 static void sg_pool_free(struct scatterlist
*sgl
, unsigned int nents
)
57 sgp
= sg_pools
+ sg_pool_index(nents
);
58 mempool_free(sgl
, sgp
->pool
);
61 static struct scatterlist
*sg_pool_alloc(unsigned int nents
, gfp_t gfp_mask
)
65 sgp
= sg_pools
+ sg_pool_index(nents
);
66 return mempool_alloc(sgp
->pool
, gfp_mask
);
70 * sg_free_table_chained - Free a previously mapped sg table
71 * @table: The sg table header to use
72 * @first_chunk: was first_chunk not NULL in sg_alloc_table_chained?
75 * Free an sg table previously allocated and setup with
76 * sg_alloc_table_chained().
79 void sg_free_table_chained(struct sg_table
*table
, bool first_chunk
)
81 if (first_chunk
&& table
->orig_nents
<= SG_CHUNK_SIZE
)
83 __sg_free_table(table
, SG_CHUNK_SIZE
, first_chunk
, sg_pool_free
);
85 EXPORT_SYMBOL_GPL(sg_free_table_chained
);
88 * sg_alloc_table_chained - Allocate and chain SGLs in an sg table
89 * @table: The sg table header to use
90 * @nents: Number of entries in sg list
91 * @first_chunk: first SGL
94 * Allocate and chain SGLs in an sg table. If @nents@ is larger than
95 * SG_CHUNK_SIZE a chained sg table will be setup.
98 int sg_alloc_table_chained(struct sg_table
*table
, int nents
,
99 struct scatterlist
*first_chunk
)
106 if (nents
<= SG_CHUNK_SIZE
) {
107 table
->nents
= table
->orig_nents
= nents
;
108 sg_init_table(table
->sgl
, nents
);
113 ret
= __sg_alloc_table(table
, nents
, SG_CHUNK_SIZE
,
114 first_chunk
, GFP_ATOMIC
, sg_pool_alloc
);
116 sg_free_table_chained(table
, (bool)first_chunk
);
119 EXPORT_SYMBOL_GPL(sg_alloc_table_chained
);
121 static __init
int sg_pool_init(void)
125 for (i
= 0; i
< SG_MEMPOOL_NR
; i
++) {
126 struct sg_pool
*sgp
= sg_pools
+ i
;
127 int size
= sgp
->size
* sizeof(struct scatterlist
);
129 sgp
->slab
= kmem_cache_create(sgp
->name
, size
, 0,
130 SLAB_HWCACHE_ALIGN
, NULL
);
132 printk(KERN_ERR
"SG_POOL: can't init sg slab %s\n",
137 sgp
->pool
= mempool_create_slab_pool(SG_MEMPOOL_SIZE
,
140 printk(KERN_ERR
"SG_POOL: can't init sg mempool %s\n",
149 for (i
= 0; i
< SG_MEMPOOL_NR
; i
++) {
150 struct sg_pool
*sgp
= sg_pools
+ i
;
152 mempool_destroy(sgp
->pool
);
153 kmem_cache_destroy(sgp
->slab
);
159 static __exit
void sg_pool_exit(void)
163 for (i
= 0; i
< SG_MEMPOOL_NR
; i
++) {
164 struct sg_pool
*sgp
= sg_pools
+ i
;
165 mempool_destroy(sgp
->pool
);
166 kmem_cache_destroy(sgp
->slab
);
170 module_init(sg_pool_init
);
171 module_exit(sg_pool_exit
);