diff options
| -rw-r--r-- | drivers/scsi/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 137 | ||||
| -rw-r--r-- | include/linux/scatterlist.h | 25 | ||||
| -rw-r--r-- | include/scsi/scsi.h | 19 | ||||
| -rw-r--r-- | lib/Kconfig | 7 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/sg_pool.c | 172 |
7 files changed, 206 insertions, 156 deletions
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig index 0950567..98e5d51 100644 --- a/drivers/scsi/Kconfig +++ b/drivers/scsi/Kconfig @@ -17,6 +17,7 @@ config SCSI tristate "SCSI device support" depends on BLOCK select SCSI_DMA if HAS_DMA + select SG_POOL ---help--- If you want to use a SCSI hard disk, SCSI tape drive, SCSI CD-ROM or any other SCSI device under Linux, say Y and make sure that you know diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 8f776f1..b920c5d 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -14,8 +14,6 @@ #include <linux/completion.h> #include <linux/kernel.h> #include <linux/export.h> -#include <linux/mempool.h> -#include <linux/slab.h> #include <linux/init.h> #include <linux/pci.h> #include <linux/delay.h> @@ -40,39 +38,6 @@ #include "scsi_logging.h" -#define SG_MEMPOOL_NR ARRAY_SIZE(sg_pools) -#define SG_MEMPOOL_SIZE 2 - -struct sg_pool { - size_t size; - char *name; - struct kmem_cache *slab; - mempool_t *pool; -}; - -#define SP(x) { .size = x, "sgpool-" __stringify(x) } -#if (SG_CHUNK_SIZE < 32) -#error SG_CHUNK_SIZE is too small (must be 32 or greater) -#endif -static struct sg_pool sg_pools[] = { - SP(8), - SP(16), -#if (SG_CHUNK_SIZE > 32) - SP(32), -#if (SG_CHUNK_SIZE > 64) - SP(64), -#if (SG_CHUNK_SIZE > 128) - SP(128), -#if (SG_CHUNK_SIZE > 256) -#error SG_CHUNK_SIZE is too large (256 MAX) -#endif -#endif -#endif -#endif - SP(SG_CHUNK_SIZE) -}; -#undef SP - struct kmem_cache *scsi_sdb_cache; /* @@ -553,65 +518,6 @@ void scsi_run_host_queues(struct Scsi_Host *shost) scsi_run_queue(sdev->request_queue); } -static inline unsigned int sg_pool_index(unsigned short nents) -{ - unsigned int index; - - BUG_ON(nents > SG_CHUNK_SIZE); - - if (nents <= 8) - index = 0; - else - index = get_count_order(nents) - 3; - - return index; -} - -static void sg_pool_free(struct scatterlist *sgl, unsigned int nents) -{ - struct sg_pool *sgp; - - sgp = sg_pools + sg_pool_index(nents); - mempool_free(sgl, sgp->pool); -} - -static struct scatterlist *sg_pool_alloc(unsigned int nents, gfp_t gfp_mask) -{ - struct sg_pool *sgp; - - sgp = sg_pools + sg_pool_index(nents); - return mempool_alloc(sgp->pool, gfp_mask); -} - -static void sg_free_table_chained(struct sg_table *table, bool first_chunk) -{ - if (first_chunk && table->orig_nents <= SG_CHUNK_SIZE) - return; - __sg_free_table(table, SG_CHUNK_SIZE, first_chunk, sg_pool_free); -} - -static int sg_alloc_table_chained(struct sg_table *table, int nents, - struct scatterlist *first_chunk) -{ - int ret; - - BUG_ON(!nents); - - if (first_chunk) { - if (nents <= SG_CHUNK_SIZE) { - table->nents = table->orig_nents = nents; - sg_init_table(table->sgl, nents); - return 0; - } - } - - ret = __sg_alloc_table(table, nents, SG_CHUNK_SIZE, - first_chunk, GFP_ATOMIC, sg_pool_alloc); - if (unlikely(ret)) - sg_free_table_chained(table, (bool)first_chunk); - return ret; -} - static void scsi_uninit_cmd(struct scsi_cmnd *cmd) { if (cmd->request->cmd_type == REQ_TYPE_FS) { @@ -2269,8 +2175,6 @@ EXPORT_SYMBOL(scsi_unblock_requests); int __init scsi_init_queue(void) { - int i; - scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", sizeof(struct scsi_data_buffer), 0, 0, NULL); @@ -2279,53 +2183,12 @@ int __init scsi_init_queue(void) return -ENOMEM; } - for (i = 0; i < SG_MEMPOOL_NR; i++) { - struct sg_pool *sgp = sg_pools + i; - int size = sgp->size * sizeof(struct scatterlist); - - sgp->slab = kmem_cache_create(sgp->name, size, 0, - SLAB_HWCACHE_ALIGN, NULL); - if (!sgp->slab) { - printk(KERN_ERR "SCSI: can't init sg slab %s\n", - sgp->name); - goto cleanup_sdb; - } - - sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, - sgp->slab); - if (!sgp->pool) { - printk(KERN_ERR "SCSI: can't init sg mempool %s\n", - sgp->name); - goto cleanup_sdb; - } - } - return 0; - -cleanup_sdb: - for (i = 0; i < SG_MEMPOOL_NR; i++) { - struct sg_pool *sgp = sg_pools + i; - if (sgp->pool) - mempool_destroy(sgp->pool); - if (sgp->slab) - kmem_cache_destroy(sgp->slab); - } - kmem_cache_destroy(scsi_sdb_cache); - - return -ENOMEM; } void scsi_exit_queue(void) { - int i; - kmem_cache_destroy(scsi_sdb_cache); - - for (i = 0; i < SG_MEMPOOL_NR; i++) { - struct sg_pool *sgp = sg_pools + i; - mempool_destroy(sgp->pool); - kmem_cache_destroy(sgp->slab); - } } /** diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 556ec1e..cb3c8fe 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -286,6 +286,31 @@ size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, #define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist)) /* + * The maximum number of SG segments that we will put inside a + * scatterlist (unless chaining is used). Should ideally fit inside a + * single page, to avoid a higher order allocation. We could define this + * to SG_MAX_SINGLE_ALLOC to pack correctly at the highest order. The + * minimum value is 32 + */ +#define SG_CHUNK_SIZE 128 + +/* + * Like SG_CHUNK_SIZE, but for archs that have sg chaining. This limit + * is totally arbitrary, a setting of 2048 will get you at least 8mb ios. + */ +#ifdef CONFIG_ARCH_HAS_SG_CHAIN +#define SG_MAX_SEGMENTS 2048 +#else +#define SG_MAX_SEGMENTS SG_CHUNK_SIZE +#endif + +#ifdef CONFIG_SG_POOL +void sg_free_table_chained(struct sg_table *table, bool first_chunk); +int sg_alloc_table_chained(struct sg_table *table, int nents, + struct scatterlist *first_chunk); +#endif + +/* * sg page iterator * * Iterates over sg entries page-by-page. On each successful iteration, diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index 74dafa7..8ec7c30 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -18,25 +18,6 @@ enum scsi_timeouts { }; /* - * The maximum number of SG segments that we will put inside a - * scatterlist (unless chaining is used). Should ideally fit inside a - * single page, to avoid a higher order allocation. We could define this - * to SG_MAX_SINGLE_ALLOC to pack correctly at the highest order. The - * minimum value is 32 - */ -#define SG_CHUNK_SIZE 128 - -/* - * Like SG_CHUNK_SIZE, but for archs that have sg chaining. This limit - * is totally arbitrary, a setting of 2048 will get you at least 8mb ios. - */ -#ifdef CONFIG_ARCH_HAS_SG_CHAIN -#define SG_MAX_SEGMENTS 2048 -#else -#define SG_MAX_SEGMENTS SG_CHUNK_SIZE -#endif - -/* * DIX-capable adapters effectively support infinite chaining for the * protection information scatterlist */ diff --git a/lib/Kconfig b/lib/Kconfig index 3cca122..61d55bd 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -523,6 +523,13 @@ config SG_SPLIT a scatterlist. This should be selected by a driver or an API which whishes to split a scatterlist amongst multiple DMA channels. +config SG_POOL + def_bool n + help + Provides a helper to allocate chained scatterlists. This should be + selected by a driver or an API which whishes to allocate chained + scatterlist. + # # sg chaining option # diff --git a/lib/Makefile b/lib/Makefile index 7bd6fd4..bf01c26 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -178,6 +178,7 @@ obj-$(CONFIG_GENERIC_STRNLEN_USER) += strnlen_user.o obj-$(CONFIG_GENERIC_NET_UTILS) += net_utils.o obj-$(CONFIG_SG_SPLIT) += sg_split.o +obj-$(CONFIG_SG_POOL) += sg_pool.o obj-$(CONFIG_STMP_DEVICE) += stmp_device.o obj-$(CONFIG_IRQ_POLL) += irq_poll.o diff --git a/lib/sg_pool.c b/lib/sg_pool.c new file mode 100644 index 0000000..6dd3061 --- /dev/null +++ b/lib/sg_pool.c @@ -0,0 +1,172 @@ +#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/mempool.h> +#include <linux/slab.h> + +#define SG_MEMPOOL_NR ARRAY_SIZE(sg_pools) +#define SG_MEMPOOL_SIZE 2 + +struct sg_pool { + size_t size; + char *name; + struct kmem_cache *slab; + mempool_t *pool; +}; + +#define SP(x) { .size = x, "sgpool-" __stringify(x) } +#if (SG_CHUNK_SIZE < 32) +#error SG_CHUNK_SIZE is too small (must be 32 or greater) +#endif +static struct sg_pool sg_pools[] = { + SP(8), + SP(16), +#if (SG_CHUNK_SIZE > 32) + SP(32), +#if (SG_CHUNK_SIZE > 64) + SP(64), +#if (SG_CHUNK_SIZE > 128) + SP(128), +#if (SG_CHUNK_SIZE > 256) +#error SG_CHUNK_SIZE is too large (256 MAX) +#endif +#endif +#endif +#endif + SP(SG_CHUNK_SIZE) +}; +#undef SP + +static inline unsigned int sg_pool_index(unsigned short nents) +{ + unsigned int index; + + BUG_ON(nents > SG_CHUNK_SIZE); + + if (nents <= 8) + index = 0; + else + index = get_count_order(nents) - 3; + + return index; +} + +static void sg_pool_free(struct scatterlist *sgl, unsigned int nents) +{ + struct sg_pool *sgp; + + sgp = sg_pools + sg_pool_index(nents); + mempool_free(sgl, sgp->pool); +} + +static struct scatterlist *sg_pool_alloc(unsigned int nents, gfp_t gfp_mask) +{ + struct sg_pool *sgp; + + sgp = sg_pools + sg_pool_index(nents); + return mempool_alloc(sgp->pool, gfp_mask); +} + +/** + * sg_free_table_chained - Free a previously mapped sg table + * @table: The sg table header to use + * @first_chunk: was first_chunk not NULL in sg_alloc_table_chained? + * + * Description: + * Free an sg table previously allocated and setup with + * sg_alloc_table_chained(). + * + **/ +void sg_free_table_chained(struct sg_table *table, bool first_chunk) +{ + if (first_chunk && table->orig_nents <= SG_CHUNK_SIZE) + return; + __sg_free_table(table, SG_CHUNK_SIZE, first_chunk, sg_pool_free); +} +EXPORT_SYMBOL_GPL(sg_free_table_chained); + +/** + * sg_alloc_table_chained - Allocate and chain SGLs in an sg table + * @table: The sg table header to use + * @nents: Number of entries in sg list + * @first_chunk: first SGL + * + * Description: + * Allocate and chain SGLs in an sg table. If @nents@ is larger than + * SG_CHUNK_SIZE a chained sg table will be setup. + * + **/ +int sg_alloc_table_chained(struct sg_table *table, int nents, + struct scatterlist *first_chunk) +{ + int ret; + + BUG_ON(!nents); + + if (first_chunk) { + if (nents <= SG_CHUNK_SIZE) { + table->nents = table->orig_nents = nents; + sg_init_table(table->sgl, nents); + return 0; + } + } + + ret = __sg_alloc_table(table, nents, SG_CHUNK_SIZE, + first_chunk, GFP_ATOMIC, sg_pool_alloc); + if (unlikely(ret)) + sg_free_table_chained(table, (bool)first_chunk); + return ret; +} +EXPORT_SYMBOL_GPL(sg_alloc_table_chained); + +static __init int sg_pool_init(void) +{ + int i; + + for (i = 0; i < SG_MEMPOOL_NR; i++) { + struct sg_pool *sgp = sg_pools + i; + int size = sgp->size * sizeof(struct scatterlist); + + sgp->slab = kmem_cache_create(sgp->name, size, 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!sgp->slab) { + printk(KERN_ERR "SG_POOL: can't init sg slab %s\n", + sgp->name); + goto cleanup_sdb; + } + + sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, + sgp->slab); + if (!sgp->pool) { + printk(KERN_ERR "SG_POOL: can't init sg mempool %s\n", + sgp->name); + goto cleanup_sdb; + } + } + + return 0; + +cleanup_sdb: + for (i = 0; i < SG_MEMPOOL_NR; i++) { + struct sg_pool *sgp = sg_pools + i; + if (sgp->pool) + mempool_destroy(sgp->pool); + if (sgp->slab) + kmem_cache_destroy(sgp->slab); + } + + return -ENOMEM; +} + +static __exit void sg_pool_exit(void) +{ + int i; + + for (i = 0; i < SG_MEMPOOL_NR; i++) { + struct sg_pool *sgp = sg_pools + i; + mempool_destroy(sgp->pool); + kmem_cache_destroy(sgp->slab); + } +} + +module_init(sg_pool_init); +module_exit(sg_pool_exit); |
