mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 19:53:59 +08:00
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
This commit is contained in:
Linus Torvalds
commit
68fbda7de0
@ -739,138 +739,43 @@ static inline unsigned int scsi_sgtable_index(unsigned short nents)
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return index;
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}
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struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
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static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
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{
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struct scsi_host_sg_pool *sgp;
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struct scatterlist *sgl, *prev, *ret;
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unsigned int index;
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int this, left;
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sgp = scsi_sg_pools + scsi_sgtable_index(nents);
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mempool_free(sgl, sgp->pool);
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}
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static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
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{
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struct scsi_host_sg_pool *sgp;
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sgp = scsi_sg_pools + scsi_sgtable_index(nents);
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return mempool_alloc(sgp->pool, gfp_mask);
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}
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int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
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{
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int ret;
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BUG_ON(!cmd->use_sg);
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left = cmd->use_sg;
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ret = prev = NULL;
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do {
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this = left;
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if (this > SCSI_MAX_SG_SEGMENTS) {
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this = SCSI_MAX_SG_SEGMENTS - 1;
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index = SG_MEMPOOL_NR - 1;
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} else
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index = scsi_sgtable_index(this);
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ret = __sg_alloc_table(&cmd->sg_table, cmd->use_sg,
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SCSI_MAX_SG_SEGMENTS, gfp_mask, scsi_sg_alloc);
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if (unlikely(ret))
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__sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS,
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scsi_sg_free);
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left -= this;
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sgp = scsi_sg_pools + index;
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sgl = mempool_alloc(sgp->pool, gfp_mask);
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if (unlikely(!sgl))
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goto enomem;
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sg_init_table(sgl, sgp->size);
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/*
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* first loop through, set initial index and return value
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*/
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if (!ret)
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ret = sgl;
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/*
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* chain previous sglist, if any. we know the previous
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* sglist must be the biggest one, or we would not have
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* ended up doing another loop.
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*/
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if (prev)
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sg_chain(prev, SCSI_MAX_SG_SEGMENTS, sgl);
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/*
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* if we have nothing left, mark the last segment as
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* end-of-list
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*/
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if (!left)
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sg_mark_end(&sgl[this - 1]);
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/*
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* don't allow subsequent mempool allocs to sleep, it would
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* violate the mempool principle.
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*/
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gfp_mask &= ~__GFP_WAIT;
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gfp_mask |= __GFP_HIGH;
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prev = sgl;
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} while (left);
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/*
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* ->use_sg may get modified after dma mapping has potentially
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* shrunk the number of segments, so keep a copy of it for free.
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*/
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cmd->__use_sg = cmd->use_sg;
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cmd->request_buffer = cmd->sg_table.sgl;
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return ret;
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enomem:
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if (ret) {
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/*
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* Free entries chained off ret. Since we were trying to
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* allocate another sglist, we know that all entries are of
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* the max size.
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*/
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sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
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prev = ret;
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ret = &ret[SCSI_MAX_SG_SEGMENTS - 1];
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while ((sgl = sg_chain_ptr(ret)) != NULL) {
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ret = &sgl[SCSI_MAX_SG_SEGMENTS - 1];
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mempool_free(sgl, sgp->pool);
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}
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mempool_free(prev, sgp->pool);
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}
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return NULL;
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}
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EXPORT_SYMBOL(scsi_alloc_sgtable);
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void scsi_free_sgtable(struct scsi_cmnd *cmd)
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{
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struct scatterlist *sgl = cmd->request_buffer;
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struct scsi_host_sg_pool *sgp;
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/*
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* if this is the biggest size sglist, check if we have
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* chained parts we need to free
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*/
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if (cmd->__use_sg > SCSI_MAX_SG_SEGMENTS) {
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unsigned short this, left;
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struct scatterlist *next;
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unsigned int index;
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left = cmd->__use_sg - (SCSI_MAX_SG_SEGMENTS - 1);
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next = sg_chain_ptr(&sgl[SCSI_MAX_SG_SEGMENTS - 1]);
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while (left && next) {
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sgl = next;
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this = left;
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if (this > SCSI_MAX_SG_SEGMENTS) {
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this = SCSI_MAX_SG_SEGMENTS - 1;
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index = SG_MEMPOOL_NR - 1;
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} else
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index = scsi_sgtable_index(this);
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left -= this;
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sgp = scsi_sg_pools + index;
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if (left)
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next = sg_chain_ptr(&sgl[sgp->size - 1]);
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mempool_free(sgl, sgp->pool);
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}
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/*
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* Restore original, will be freed below
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*/
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sgl = cmd->request_buffer;
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sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
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} else
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sgp = scsi_sg_pools + scsi_sgtable_index(cmd->__use_sg);
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mempool_free(sgl, sgp->pool);
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__sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
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}
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EXPORT_SYMBOL(scsi_free_sgtable);
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@ -1120,8 +1025,7 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
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/*
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* If sg table allocation fails, requeue request later.
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*/
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cmd->request_buffer = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
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if (unlikely(!cmd->request_buffer)) {
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if (unlikely(scsi_alloc_sgtable(cmd, GFP_ATOMIC))) {
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scsi_unprep_request(req);
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return BLKPREP_DEFER;
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}
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@ -359,8 +359,7 @@ static int scsi_tgt_init_cmd(struct scsi_cmnd *cmd, gfp_t gfp_mask)
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int count;
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cmd->use_sg = rq->nr_phys_segments;
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cmd->request_buffer = scsi_alloc_sgtable(cmd, gfp_mask);
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if (!cmd->request_buffer)
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if (scsi_alloc_sgtable(cmd, gfp_mask))
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return -ENOMEM;
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cmd->request_bufflen = rq->data_len;
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@ -7,6 +7,12 @@
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#include <linux/string.h>
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#include <asm/io.h>
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struct sg_table {
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struct scatterlist *sgl; /* the list */
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unsigned int nents; /* number of mapped entries */
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unsigned int orig_nents; /* original size of list */
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};
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/*
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* Notes on SG table design.
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*
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@ -106,71 +112,12 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
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sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
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}
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/**
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* sg_next - return the next scatterlist entry in a list
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* @sg: The current sg entry
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*
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* Description:
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* Usually the next entry will be @sg@ + 1, but if this sg element is part
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* of a chained scatterlist, it could jump to the start of a new
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* scatterlist array.
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*
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**/
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static inline struct scatterlist *sg_next(struct scatterlist *sg)
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{
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#ifdef CONFIG_DEBUG_SG
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BUG_ON(sg->sg_magic != SG_MAGIC);
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#endif
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if (sg_is_last(sg))
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return NULL;
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sg++;
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if (unlikely(sg_is_chain(sg)))
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sg = sg_chain_ptr(sg);
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return sg;
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}
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/*
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* Loop over each sg element, following the pointer to a new list if necessary
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*/
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#define for_each_sg(sglist, sg, nr, __i) \
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for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
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/**
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* sg_last - return the last scatterlist entry in a list
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* @sgl: First entry in the scatterlist
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* @nents: Number of entries in the scatterlist
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*
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* Description:
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* Should only be used casually, it (currently) scan the entire list
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* to get the last entry.
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*
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* Note that the @sgl@ pointer passed in need not be the first one,
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* the important bit is that @nents@ denotes the number of entries that
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* exist from @sgl@.
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*
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**/
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static inline struct scatterlist *sg_last(struct scatterlist *sgl,
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unsigned int nents)
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{
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#ifndef ARCH_HAS_SG_CHAIN
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struct scatterlist *ret = &sgl[nents - 1];
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#else
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struct scatterlist *sg, *ret = NULL;
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unsigned int i;
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for_each_sg(sgl, sg, nents, i)
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ret = sg;
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#endif
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#ifdef CONFIG_DEBUG_SG
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BUG_ON(sgl[0].sg_magic != SG_MAGIC);
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BUG_ON(!sg_is_last(ret));
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#endif
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return ret;
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}
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/**
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* sg_chain - Chain two sglists together
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* @prv: First scatterlist
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@ -222,47 +169,6 @@ static inline void sg_mark_end(struct scatterlist *sg)
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sg->page_link &= ~0x01;
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}
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/**
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* sg_init_table - Initialize SG table
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* @sgl: The SG table
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* @nents: Number of entries in table
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*
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* Notes:
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* If this is part of a chained sg table, sg_mark_end() should be
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* used only on the last table part.
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*
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**/
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static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
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{
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memset(sgl, 0, sizeof(*sgl) * nents);
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#ifdef CONFIG_DEBUG_SG
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{
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unsigned int i;
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for (i = 0; i < nents; i++)
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sgl[i].sg_magic = SG_MAGIC;
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}
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#endif
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sg_mark_end(&sgl[nents - 1]);
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}
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/**
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* sg_init_one - Initialize a single entry sg list
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* @sg: SG entry
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* @buf: Virtual address for IO
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* @buflen: IO length
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*
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* Notes:
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* This should not be used on a single entry that is part of a larger
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* table. Use sg_init_table() for that.
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*
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**/
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static inline void sg_init_one(struct scatterlist *sg, const void *buf,
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unsigned int buflen)
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{
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sg_init_table(sg, 1);
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sg_set_buf(sg, buf, buflen);
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}
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/**
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* sg_phys - Return physical address of an sg entry
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* @sg: SG entry
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@ -293,4 +199,24 @@ static inline void *sg_virt(struct scatterlist *sg)
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return page_address(sg_page(sg)) + sg->offset;
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}
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struct scatterlist *sg_next(struct scatterlist *);
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struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
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void sg_init_table(struct scatterlist *, unsigned int);
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void sg_init_one(struct scatterlist *, const void *, unsigned int);
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typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
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typedef void (sg_free_fn)(struct scatterlist *, unsigned int);
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void __sg_free_table(struct sg_table *, unsigned int, sg_free_fn *);
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void sg_free_table(struct sg_table *);
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int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, gfp_t,
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sg_alloc_fn *);
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int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
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/*
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* Maximum number of entries that will be allocated in one piece, if
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* a list larger than this is required then chaining will be utilized.
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*/
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#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
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#endif /* _LINUX_SCATTERLIST_H */
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@ -8,7 +8,6 @@
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#include <linux/scatterlist.h>
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struct request;
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struct scatterlist;
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struct Scsi_Host;
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struct scsi_device;
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@ -68,8 +67,8 @@ struct scsi_cmnd {
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void *request_buffer; /* Actual requested buffer */
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/* These elements define the operation we ultimately want to perform */
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struct sg_table sg_table;
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unsigned short use_sg; /* Number of pieces of scatter-gather */
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unsigned short __use_sg;
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unsigned underflow; /* Return error if less than
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this amount is transferred */
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@ -128,14 +127,14 @@ extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
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size_t *offset, size_t *len);
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extern void scsi_kunmap_atomic_sg(void *virt);
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extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
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extern int scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
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extern void scsi_free_sgtable(struct scsi_cmnd *);
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extern int scsi_dma_map(struct scsi_cmnd *cmd);
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extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
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#define scsi_sg_count(cmd) ((cmd)->use_sg)
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#define scsi_sglist(cmd) ((struct scatterlist *)(cmd)->request_buffer)
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#define scsi_sglist(cmd) ((cmd)->sg_table.sgl)
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#define scsi_bufflen(cmd) ((cmd)->request_bufflen)
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static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
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@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
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rbtree.o radix-tree.o dump_stack.o \
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idr.o int_sqrt.o extable.o prio_tree.o \
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sha1.o irq_regs.o reciprocal_div.o argv_split.o \
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proportions.o prio_heap.o
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proportions.o prio_heap.o scatterlist.o
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|
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lib-$(CONFIG_MMU) += ioremap.o
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lib-$(CONFIG_SMP) += cpumask.o
|
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|
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294
lib/scatterlist.c
Normal file
294
lib/scatterlist.c
Normal file
@ -0,0 +1,294 @@
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/*
|
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* Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
|
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*
|
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* Scatterlist handling helpers.
|
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*
|
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* This source code is licensed under the GNU General Public License,
|
||||
* Version 2. See the file COPYING for more details.
|
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*/
|
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#include <linux/module.h>
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#include <linux/scatterlist.h>
|
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|
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/**
|
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* sg_next - return the next scatterlist entry in a list
|
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* @sg: The current sg entry
|
||||
*
|
||||
* Description:
|
||||
* Usually the next entry will be @sg@ + 1, but if this sg element is part
|
||||
* of a chained scatterlist, it could jump to the start of a new
|
||||
* scatterlist array.
|
||||
*
|
||||
**/
|
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struct scatterlist *sg_next(struct scatterlist *sg)
|
||||
{
|
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#ifdef CONFIG_DEBUG_SG
|
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BUG_ON(sg->sg_magic != SG_MAGIC);
|
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#endif
|
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if (sg_is_last(sg))
|
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return NULL;
|
||||
|
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sg++;
|
||||
if (unlikely(sg_is_chain(sg)))
|
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sg = sg_chain_ptr(sg);
|
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|
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return sg;
|
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}
|
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EXPORT_SYMBOL(sg_next);
|
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|
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/**
|
||||
* sg_last - return the last scatterlist entry in a list
|
||||
* @sgl: First entry in the scatterlist
|
||||
* @nents: Number of entries in the scatterlist
|
||||
*
|
||||
* Description:
|
||||
* Should only be used casually, it (currently) scans the entire list
|
||||
* to get the last entry.
|
||||
*
|
||||
* Note that the @sgl@ pointer passed in need not be the first one,
|
||||
* the important bit is that @nents@ denotes the number of entries that
|
||||
* exist from @sgl@.
|
||||
*
|
||||
**/
|
||||
struct scatterlist *sg_last(struct scatterlist *sgl, unsigned int nents)
|
||||
{
|
||||
#ifndef ARCH_HAS_SG_CHAIN
|
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struct scatterlist *ret = &sgl[nents - 1];
|
||||
#else
|
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struct scatterlist *sg, *ret = NULL;
|
||||
unsigned int i;
|
||||
|
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for_each_sg(sgl, sg, nents, i)
|
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ret = sg;
|
||||
|
||||
#endif
|
||||
#ifdef CONFIG_DEBUG_SG
|
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BUG_ON(sgl[0].sg_magic != SG_MAGIC);
|
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BUG_ON(!sg_is_last(ret));
|
||||
#endif
|
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return ret;
|
||||
}
|
||||
EXPORT_SYMBOL(sg_last);
|
||||
|
||||
/**
|
||||
* sg_init_table - Initialize SG table
|
||||
* @sgl: The SG table
|
||||
* @nents: Number of entries in table
|
||||
*
|
||||
* Notes:
|
||||
* If this is part of a chained sg table, sg_mark_end() should be
|
||||
* used only on the last table part.
|
||||
*
|
||||
**/
|
||||
void sg_init_table(struct scatterlist *sgl, unsigned int nents)
|
||||
{
|
||||
memset(sgl, 0, sizeof(*sgl) * nents);
|
||||
#ifdef CONFIG_DEBUG_SG
|
||||
{
|
||||
unsigned int i;
|
||||
for (i = 0; i < nents; i++)
|
||||
sgl[i].sg_magic = SG_MAGIC;
|
||||
}
|
||||
#endif
|
||||
sg_mark_end(&sgl[nents - 1]);
|
||||
}
|
||||
EXPORT_SYMBOL(sg_init_table);
|
||||
|
||||
/**
|
||||
* sg_init_one - Initialize a single entry sg list
|
||||
* @sg: SG entry
|
||||
* @buf: Virtual address for IO
|
||||
* @buflen: IO length
|
||||
*
|
||||
**/
|
||||
void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen)
|
||||
{
|
||||
sg_init_table(sg, 1);
|
||||
sg_set_buf(sg, buf, buflen);
|
||||
}
|
||||
EXPORT_SYMBOL(sg_init_one);
|
||||
|
||||
/*
|
||||
* The default behaviour of sg_alloc_table() is to use these kmalloc/kfree
|
||||
* helpers.
|
||||
*/
|
||||
static struct scatterlist *sg_kmalloc(unsigned int nents, gfp_t gfp_mask)
|
||||
{
|
||||
if (nents == SG_MAX_SINGLE_ALLOC)
|
||||
return (struct scatterlist *) __get_free_page(gfp_mask);
|
||||
else
|
||||
return kmalloc(nents * sizeof(struct scatterlist), gfp_mask);
|
||||
}
|
||||
|
||||
static void sg_kfree(struct scatterlist *sg, unsigned int nents)
|
||||
{
|
||||
if (nents == SG_MAX_SINGLE_ALLOC)
|
||||
free_page((unsigned long) sg);
|
||||
else
|
||||
kfree(sg);
|
||||
}
|
||||
|
||||
/**
|
||||
* __sg_free_table - Free a previously mapped sg table
|
||||
* @table: The sg table header to use
|
||||
* @max_ents: The maximum number of entries per single scatterlist
|
||||
* @free_fn: Free function
|
||||
*
|
||||
* Description:
|
||||
* Free an sg table previously allocated and setup with
|
||||
* __sg_alloc_table(). The @max_ents value must be identical to
|
||||
* that previously used with __sg_alloc_table().
|
||||
*
|
||||
**/
|
||||
void __sg_free_table(struct sg_table *table, unsigned int max_ents,
|
||||
sg_free_fn *free_fn)
|
||||
{
|
||||
struct scatterlist *sgl, *next;
|
||||
|
||||
if (unlikely(!table->sgl))
|
||||
return;
|
||||
|
||||
sgl = table->sgl;
|
||||
while (table->orig_nents) {
|
||||
unsigned int alloc_size = table->orig_nents;
|
||||
unsigned int sg_size;
|
||||
|
||||
/*
|
||||
* If we have more than max_ents segments left,
|
||||
* then assign 'next' to the sg table after the current one.
|
||||
* sg_size is then one less than alloc size, since the last
|
||||
* element is the chain pointer.
|
||||
*/
|
||||
if (alloc_size > max_ents) {
|
||||
next = sg_chain_ptr(&sgl[max_ents - 1]);
|
||||
alloc_size = max_ents;
|
||||
sg_size = alloc_size - 1;
|
||||
} else {
|
||||
sg_size = alloc_size;
|
||||
next = NULL;
|
||||
}
|
||||
|
||||
table->orig_nents -= sg_size;
|
||||
free_fn(sgl, alloc_size);
|
||||
sgl = next;
|
||||
}
|
||||
|
||||
table->sgl = NULL;
|
||||
}
|
||||
EXPORT_SYMBOL(__sg_free_table);
|
||||
|
||||
/**
|
||||
* sg_free_table - Free a previously allocated sg table
|
||||
* @table: The mapped sg table header
|
||||
*
|
||||
**/
|
||||
void sg_free_table(struct sg_table *table)
|
||||
{
|
||||
__sg_free_table(table, SG_MAX_SINGLE_ALLOC, sg_kfree);
|
||||
}
|
||||
EXPORT_SYMBOL(sg_free_table);
|
||||
|
||||
/**
|
||||
* __sg_alloc_table - Allocate and initialize an sg table with given allocator
|
||||
* @table: The sg table header to use
|
||||
* @nents: Number of entries in sg list
|
||||
* @max_ents: The maximum number of entries the allocator returns per call
|
||||
* @gfp_mask: GFP allocation mask
|
||||
* @alloc_fn: Allocator to use
|
||||
*
|
||||
* Description:
|
||||
* This function returns a @table @nents long. The allocator is
|
||||
* defined to return scatterlist chunks of maximum size @max_ents.
|
||||
* Thus if @nents is bigger than @max_ents, the scatterlists will be
|
||||
* chained in units of @max_ents.
|
||||
*
|
||||
* Notes:
|
||||
* If this function returns non-0 (eg failure), the caller must call
|
||||
* __sg_free_table() to cleanup any leftover allocations.
|
||||
*
|
||||
**/
|
||||
int __sg_alloc_table(struct sg_table *table, unsigned int nents,
|
||||
unsigned int max_ents, gfp_t gfp_mask,
|
||||
sg_alloc_fn *alloc_fn)
|
||||
{
|
||||
struct scatterlist *sg, *prv;
|
||||
unsigned int left;
|
||||
|
||||
#ifndef ARCH_HAS_SG_CHAIN
|
||||
BUG_ON(nents > max_ents);
|
||||
#endif
|
||||
|
||||
memset(table, 0, sizeof(*table));
|
||||
|
||||
left = nents;
|
||||
prv = NULL;
|
||||
do {
|
||||
unsigned int sg_size, alloc_size = left;
|
||||
|
||||
if (alloc_size > max_ents) {
|
||||
alloc_size = max_ents;
|
||||
sg_size = alloc_size - 1;
|
||||
} else
|
||||
sg_size = alloc_size;
|
||||
|
||||
left -= sg_size;
|
||||
|
||||
sg = alloc_fn(alloc_size, gfp_mask);
|
||||
if (unlikely(!sg))
|
||||
return -ENOMEM;
|
||||
|
||||
sg_init_table(sg, alloc_size);
|
||||
table->nents = table->orig_nents += sg_size;
|
||||
|
||||
/*
|
||||
* If this is the first mapping, assign the sg table header.
|
||||
* If this is not the first mapping, chain previous part.
|
||||
*/
|
||||
if (prv)
|
||||
sg_chain(prv, max_ents, sg);
|
||||
else
|
||||
table->sgl = sg;
|
||||
|
||||
/*
|
||||
* If no more entries after this one, mark the end
|
||||
*/
|
||||
if (!left)
|
||||
sg_mark_end(&sg[sg_size - 1]);
|
||||
|
||||
/*
|
||||
* only really needed for mempool backed sg allocations (like
|
||||
* SCSI), a possible improvement here would be to pass the
|
||||
* table pointer into the allocator and let that clear these
|
||||
* flags
|
||||
*/
|
||||
gfp_mask &= ~__GFP_WAIT;
|
||||
gfp_mask |= __GFP_HIGH;
|
||||
prv = sg;
|
||||
} while (left);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL(__sg_alloc_table);
|
||||
|
||||
/**
|
||||
* sg_alloc_table - Allocate and initialize an sg table
|
||||
* @table: The sg table header to use
|
||||
* @nents: Number of entries in sg list
|
||||
* @gfp_mask: GFP allocation mask
|
||||
*
|
||||
* Description:
|
||||
* Allocate and initialize an sg table. If @nents@ is larger than
|
||||
* SG_MAX_SINGLE_ALLOC a chained sg table will be setup.
|
||||
*
|
||||
**/
|
||||
int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC,
|
||||
gfp_mask, sg_kmalloc);
|
||||
if (unlikely(ret))
|
||||
__sg_free_table(table, SG_MAX_SINGLE_ALLOC, sg_kfree);
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL(sg_alloc_table);
|
||||
Loading…
Reference in New Issue
Block a user