diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-01-28 21:51:05 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-01-28 21:51:05 (GMT) |
commit | 68fbda7de07e56eb90dd6e58a162527411b388b1 (patch) | |
tree | 118f82bb86fdf9dd3480ccabf96a7e5d3ab8bdb9 /drivers | |
parent | d4928196fe9ec07d18139ba2735876b0c8aa738f (diff) | |
parent | 7cedb1f17fb7f4374d11501f61656ae9d3ba47e9 (diff) | |
download | linux-fsl-qoriq-68fbda7de07e56eb90dd6e58a162527411b388b1.tar.xz |
Merge branch 'sg' of git://git.kernel.dk/linux-2.6-block
* 'sg' of git://git.kernel.dk/linux-2.6-block:
SG: work with the SCSI fixed maximum allocations.
SG: Convert SCSI to use scatterlist helpers for sg chaining
SG: Move functions to lib/scatterlist.c and add sg chaining allocator helpers
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 140 | ||||
-rw-r--r-- | drivers/scsi/scsi_tgt_lib.c | 3 |
2 files changed, 23 insertions, 120 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 4cf902e..eb4911a 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -739,138 +739,43 @@ static inline unsigned int scsi_sgtable_index(unsigned short nents) return index; } -struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) +static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) { struct scsi_host_sg_pool *sgp; - struct scatterlist *sgl, *prev, *ret; - unsigned int index; - int this, left; - - BUG_ON(!cmd->use_sg); - - left = cmd->use_sg; - ret = prev = NULL; - do { - this = left; - if (this > SCSI_MAX_SG_SEGMENTS) { - this = SCSI_MAX_SG_SEGMENTS - 1; - index = SG_MEMPOOL_NR - 1; - } else - index = scsi_sgtable_index(this); - left -= this; - - sgp = scsi_sg_pools + index; + sgp = scsi_sg_pools + scsi_sgtable_index(nents); + mempool_free(sgl, sgp->pool); +} - sgl = mempool_alloc(sgp->pool, gfp_mask); - if (unlikely(!sgl)) - goto enomem; +static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) +{ + struct scsi_host_sg_pool *sgp; - sg_init_table(sgl, sgp->size); + sgp = scsi_sg_pools + scsi_sgtable_index(nents); + return mempool_alloc(sgp->pool, gfp_mask); +} - /* - * first loop through, set initial index and return value - */ - if (!ret) - ret = sgl; +int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) +{ + int ret; - /* - * chain previous sglist, if any. we know the previous - * sglist must be the biggest one, or we would not have - * ended up doing another loop. - */ - if (prev) - sg_chain(prev, SCSI_MAX_SG_SEGMENTS, sgl); + BUG_ON(!cmd->use_sg); - /* - * if we have nothing left, mark the last segment as - * end-of-list - */ - if (!left) - sg_mark_end(&sgl[this - 1]); + ret = __sg_alloc_table(&cmd->sg_table, cmd->use_sg, + SCSI_MAX_SG_SEGMENTS, gfp_mask, scsi_sg_alloc); + if (unlikely(ret)) + __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, + scsi_sg_free); - /* - * don't allow subsequent mempool allocs to sleep, it would - * violate the mempool principle. - */ - gfp_mask &= ~__GFP_WAIT; - gfp_mask |= __GFP_HIGH; - prev = sgl; - } while (left); - - /* - * ->use_sg may get modified after dma mapping has potentially - * shrunk the number of segments, so keep a copy of it for free. - */ - cmd->__use_sg = cmd->use_sg; + cmd->request_buffer = cmd->sg_table.sgl; return ret; -enomem: - if (ret) { - /* - * Free entries chained off ret. Since we were trying to - * allocate another sglist, we know that all entries are of - * the max size. - */ - sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1; - prev = ret; - ret = &ret[SCSI_MAX_SG_SEGMENTS - 1]; - - while ((sgl = sg_chain_ptr(ret)) != NULL) { - ret = &sgl[SCSI_MAX_SG_SEGMENTS - 1]; - mempool_free(sgl, sgp->pool); - } - - mempool_free(prev, sgp->pool); - } - return NULL; } EXPORT_SYMBOL(scsi_alloc_sgtable); void scsi_free_sgtable(struct scsi_cmnd *cmd) { - struct scatterlist *sgl = cmd->request_buffer; - struct scsi_host_sg_pool *sgp; - - /* - * if this is the biggest size sglist, check if we have - * chained parts we need to free - */ - if (cmd->__use_sg > SCSI_MAX_SG_SEGMENTS) { - unsigned short this, left; - struct scatterlist *next; - unsigned int index; - - left = cmd->__use_sg - (SCSI_MAX_SG_SEGMENTS - 1); - next = sg_chain_ptr(&sgl[SCSI_MAX_SG_SEGMENTS - 1]); - while (left && next) { - sgl = next; - this = left; - if (this > SCSI_MAX_SG_SEGMENTS) { - this = SCSI_MAX_SG_SEGMENTS - 1; - index = SG_MEMPOOL_NR - 1; - } else - index = scsi_sgtable_index(this); - - left -= this; - - sgp = scsi_sg_pools + index; - - if (left) - next = sg_chain_ptr(&sgl[sgp->size - 1]); - - mempool_free(sgl, sgp->pool); - } - - /* - * Restore original, will be freed below - */ - sgl = cmd->request_buffer; - sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1; - } else - sgp = scsi_sg_pools + scsi_sgtable_index(cmd->__use_sg); - - mempool_free(sgl, sgp->pool); + __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); } EXPORT_SYMBOL(scsi_free_sgtable); @@ -1120,8 +1025,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd) /* * If sg table allocation fails, requeue request later. */ - cmd->request_buffer = scsi_alloc_sgtable(cmd, GFP_ATOMIC); - if (unlikely(!cmd->request_buffer)) { + if (unlikely(scsi_alloc_sgtable(cmd, GFP_ATOMIC))) { scsi_unprep_request(req); return BLKPREP_DEFER; } diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c index 93ece8f..01e03f3 100644 --- a/drivers/scsi/scsi_tgt_lib.c +++ b/drivers/scsi/scsi_tgt_lib.c @@ -359,8 +359,7 @@ static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask) int count; cmd->use_sg = rq->nr_phys_segments; - cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask); - if (!cmd->request_buffer) + if (scsi_alloc_sgtable(cmd, gfp_mask)) return -ENOMEM; cmd->request_bufflen = rq->data_len; |