Merge branch 'sg' of git://git.kernel.dk/linux-2.6-block (68fbda7d) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/scsi/scsi_lib.c

+22 −118

Original line number	Diff line number	Diff line
		@@ -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;

		sgl = mempool_alloc(sgp->pool, gfp_mask);
		if (unlikely(!sgl))
		goto enomem;

		sg_init_table(sgl, sgp->size);

		/*
		* first loop through, set initial index and return value
		*/
		if (!ret)
		ret = sgl;

		/*
		* 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);

		/*
		* if we have nothing left, mark the last segment as
		* end-of-list
		*/
		if (!left)
		sg_mark_end(&sgl[this - 1]);

		/*
		* 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;
		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];
		sgp = scsi_sg_pools + scsi_sgtable_index(nents);
		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)
		static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
		{
		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);
		sgp = scsi_sg_pools + scsi_sgtable_index(nents);
		return mempool_alloc(sgp->pool, gfp_mask);
		}

		left -= this;
		int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
		{
		int ret;

		sgp = scsi_sg_pools + index;
		BUG_ON(!cmd->use_sg);

		if (left)
		next = sg_chain_ptr(&sgl[sgp->size - 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);

		mempool_free(sgl, sgp->pool);
		cmd->request_buffer = cmd->sg_table.sgl;
		return ret;
		}

		/*
		* 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);
		EXPORT_SYMBOL(scsi_alloc_sgtable);

		mempool_free(sgl, sgp->pool);
		void scsi_free_sgtable(struct scsi_cmnd *cmd)
		{
		__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;
		}

drivers/scsi/scsi_tgt_lib.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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;

include/linux/scatterlist.h

+26 −100

Original line number	Diff line number	Diff line
		@@ -7,6 +7,12 @@
		#include <linux/string.h>
		#include <asm/io.h>

		struct sg_table {
		struct scatterlist sgl; / the list */
		unsigned int nents; /* number of mapped entries */
		unsigned int orig_nents; /* original size of list */
		};

		/*
		* Notes on SG table design.
		*
		@@ -106,71 +112,12 @@ static inline void sg_set_buf(struct scatterlist sg, const void buf,
		sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
		}

		/**
		* sg_next - return the next scatterlist entry in a list
		* @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.
		*
		**/
		static inline struct scatterlist sg_next(struct scatterlist sg)
		{
		#ifdef CONFIG_DEBUG_SG
		BUG_ON(sg->sg_magic != SG_MAGIC);
		#endif
		if (sg_is_last(sg))
		return NULL;

		sg++;
		if (unlikely(sg_is_chain(sg)))
		sg = sg_chain_ptr(sg);

		return sg;
		}

		/*
		* Loop over each sg element, following the pointer to a new list if necessary
		*/
		#define for_each_sg(sglist, sg, nr, __i) \
		for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))

		/**
		* 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) scan 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@.
		*
		**/
		static inline struct scatterlist sg_last(struct scatterlist sgl,
		unsigned int nents)
		{
		#ifndef ARCH_HAS_SG_CHAIN
		struct scatterlist *ret = &sgl[nents - 1];
		#else
		struct scatterlist sg, ret = NULL;
		unsigned int i;

		for_each_sg(sgl, sg, nents, i)
		ret = sg;

		#endif
		#ifdef CONFIG_DEBUG_SG
		BUG_ON(sgl[0].sg_magic != SG_MAGIC);
		BUG_ON(!sg_is_last(ret));
		#endif
		return ret;
		}

		/**
		* sg_chain - Chain two sglists together
		* @prv: First scatterlist
		@@ -222,47 +169,6 @@ static inline void sg_mark_end(struct scatterlist *sg)
		sg->page_link &= ~0x01;
		}

		/**
		* 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.
		*
		**/
		static inline 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]);
		}

		/**
		* sg_init_one - Initialize a single entry sg list
		* @sg: SG entry
		* @buf: Virtual address for IO
		* @buflen: IO length
		*
		* Notes:
		* This should not be used on a single entry that is part of a larger
		* table. Use sg_init_table() for that.
		*
		**/
		static inline void sg_init_one(struct scatterlist sg, const void buf,
		unsigned int buflen)
		{
		sg_init_table(sg, 1);
		sg_set_buf(sg, buf, buflen);
		}

		/**
		* sg_phys - Return physical address of an sg entry
		* @sg: SG entry
		@@ -293,4 +199,24 @@ static inline void sg_virt(struct scatterlist sg)
		return page_address(sg_page(sg)) + sg->offset;
		}

		struct scatterlist sg_next(struct scatterlist );
		struct scatterlist sg_last(struct scatterlist s, unsigned int);
		void sg_init_table(struct scatterlist *, unsigned int);
		void sg_init_one(struct scatterlist , const void , unsigned int);

		typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
		typedef void (sg_free_fn)(struct scatterlist *, unsigned int);

		void __sg_free_table(struct sg_table , unsigned int, sg_free_fn );
		void sg_free_table(struct sg_table *);
		int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, gfp_t,
		sg_alloc_fn *);
		int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);

		/*
		* Maximum number of entries that will be allocated in one piece, if
		* a list larger than this is required then chaining will be utilized.
		*/
		#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))

		#endif /* _LINUX_SCATTERLIST_H */

include/scsi/scsi_cmnd.h

+3 −4

Original line number	Diff line number	Diff line
		@@ -8,7 +8,6 @@
		#include <linux/scatterlist.h>

		struct request;
		struct scatterlist;
		struct Scsi_Host;
		struct scsi_device;

		@@ -68,8 +67,8 @@ struct scsi_cmnd {
		void request_buffer; / Actual requested buffer */

		/* These elements define the operation we ultimately want to perform */
		struct sg_table sg_table;
		unsigned short use_sg; /* Number of pieces of scatter-gather */
		unsigned short __use_sg;

		unsigned underflow; /* Return error if less than
		this amount is transferred */
		@@ -128,14 +127,14 @@ extern void scsi_kmap_atomic_sg(struct scatterlist sg, int sg_count,
		size_t offset, size_t len);
		extern void scsi_kunmap_atomic_sg(void *virt);

		extern struct scatterlist scsi_alloc_sgtable(struct scsi_cmnd , gfp_t);
		extern int scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
		extern void scsi_free_sgtable(struct scsi_cmnd *);

		extern int scsi_dma_map(struct scsi_cmnd *cmd);
		extern void scsi_dma_unmap(struct scsi_cmnd *cmd);

		#define scsi_sg_count(cmd) ((cmd)->use_sg)
		#define scsi_sglist(cmd) ((struct scatterlist *)(cmd)->request_buffer)
		#define scsi_sglist(cmd) ((cmd)->sg_table.sgl)
		#define scsi_bufflen(cmd) ((cmd)->request_bufflen)

		static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)

lib/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
		rbtree.o radix-tree.o dump_stack.o \
		idr.o int_sqrt.o extable.o prio_tree.o \
		sha1.o irq_regs.o reciprocal_div.o argv_split.o \
		proportions.o prio_heap.o
		proportions.o prio_heap.o scatterlist.o

		lib-$(CONFIG_MMU) += ioremap.o
		lib-$(CONFIG_SMP) += cpumask.o