Merge tag 'scsi-sg' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI scatter-gather list updates from James Bottomley:
 "This topic branch covers a fundamental change in how our sg lists are
  allocated to make mq more efficient by reducing the size of the
  preallocated sg list.

  This necessitates a large number of driver changes because the
  previous guarantee that if a driver specified SG_ALL as the size of
  its scatter list, it would get a non-chained list and didn't need to
  bother with scatterlist iterators is now broken and every driver
  *must* use scatterlist iterators.

  This was broken out as a separate topic because we need to convert all
  the drivers before pulling the trigger and unconverted drivers kept
  being found, necessitating a rebase"

* tag 'scsi-sg' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (21 commits)
  scsi: core: don't preallocate small SGL in case of NO_SG_CHAIN
  scsi: lib/sg_pool.c: clear 'first_chunk' in case of no preallocation
  scsi: core: avoid preallocating big SGL for data
  scsi: core: avoid preallocating big SGL for protection information
  scsi: lib/sg_pool.c: improve APIs for allocating sg pool
  scsi: esp: use sg helper to iterate over scatterlist
  scsi: NCR5380: use sg helper to iterate over scatterlist
  scsi: wd33c93: use sg helper to iterate over scatterlist
  scsi: ppa: use sg helper to iterate over scatterlist
  scsi: pcmcia: nsp_cs: use sg helper to iterate over scatterlist
  scsi: imm: use sg helper to iterate over scatterlist
  scsi: aha152x: use sg helper to iterate over scatterlist
  scsi: s390: zfcp_fc: use sg helper to iterate over scatterlist
  scsi: staging: unisys: visorhba: use sg helper to iterate over scatterlist
  scsi: usb: image: microtek: use sg helper to iterate over scatterlist
  scsi: pmcraid: use sg helper to iterate over scatterlist
  scsi: ipr: use sg helper to iterate over scatterlist
  scsi: mvumi: use sg helper to iterate over scatterlist
  scsi: lpfc: use sg helper to iterate over scatterlist
  scsi: advansys: use sg helper to iterate over scatterlist
  ...

1 files changed, 16 insertions, 13 deletions

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index d06bc1a817a1..079c04bc448a 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -3901,22 +3901,23 @@ static int ipr_copy_ucode_buffer(struct ipr_sglist *sglist,
 				 u8 *buffer, u32 len)
 {
 	int bsize_elem, i, result = 0;
-	struct scatterlist *scatterlist;
+	struct scatterlist *sg;
 	void *kaddr;
 
 	/* Determine the actual number of bytes per element */
 	bsize_elem = PAGE_SIZE * (1 << sglist->order);
 
-	scatterlist = sglist->scatterlist;
+	sg = sglist->scatterlist;
 
-	for (i = 0; i < (len / bsize_elem); i++, buffer += bsize_elem) {
-		struct page *page = sg_page(&scatterlist[i]);
+	for (i = 0; i < (len / bsize_elem); i++, sg = sg_next(sg),
+			buffer += bsize_elem) {
+		struct page *page = sg_page(sg);
 
 		kaddr = kmap(page);
 		memcpy(kaddr, buffer, bsize_elem);
 		kunmap(page);
 
-		scatterlist[i].length = bsize_elem;
+		sg->length = bsize_elem;
 
 		if (result != 0) {
 			ipr_trace;
@@ -3925,13 +3926,13 @@ static int ipr_copy_ucode_buffer(struct ipr_sglist *sglist,
 	}
 
 	if (len % bsize_elem) {
-		struct page *page = sg_page(&scatterlist[i]);
+		struct page *page = sg_page(sg);
 
 		kaddr = kmap(page);
 		memcpy(kaddr, buffer, len % bsize_elem);
 		kunmap(page);
 
-		scatterlist[i].length = len % bsize_elem;
+		sg->length = len % bsize_elem;
 	}
 
 	sglist->buffer_len = len;
@@ -3952,6 +3953,7 @@ static void ipr_build_ucode_ioadl64(struct ipr_cmnd *ipr_cmd,
 	struct ipr_ioarcb *ioarcb = &ipr_cmd->ioarcb;
 	struct ipr_ioadl64_desc *ioadl64 = ipr_cmd->i.ioadl64;
 	struct scatterlist *scatterlist = sglist->scatterlist;
+	struct scatterlist *sg;
 	int i;
 
 	ipr_cmd->dma_use_sg = sglist->num_dma_sg;
@@ -3960,10 +3962,10 @@ static void ipr_build_ucode_ioadl64(struct ipr_cmnd *ipr_cmd,
 
 	ioarcb->ioadl_len =
 		cpu_to_be32(sizeof(struct ipr_ioadl64_desc) * ipr_cmd->dma_use_sg);
-	for (i = 0; i < ipr_cmd->dma_use_sg; i++) {
+	for_each_sg(scatterlist, sg, ipr_cmd->dma_use_sg, i) {
 		ioadl64[i].flags = cpu_to_be32(IPR_IOADL_FLAGS_WRITE);
-		ioadl64[i].data_len = cpu_to_be32(sg_dma_len(&scatterlist[i]));
-		ioadl64[i].address = cpu_to_be64(sg_dma_address(&scatterlist[i]));
+		ioadl64[i].data_len = cpu_to_be32(sg_dma_len(sg));
+		ioadl64[i].address = cpu_to_be64(sg_dma_address(sg));
 	}
 
 	ioadl64[i-1].flags |= cpu_to_be32(IPR_IOADL_FLAGS_LAST);
@@ -3983,6 +3985,7 @@ static void ipr_build_ucode_ioadl(struct ipr_cmnd *ipr_cmd,
 	struct ipr_ioarcb *ioarcb = &ipr_cmd->ioarcb;
 	struct ipr_ioadl_desc *ioadl = ipr_cmd->i.ioadl;
 	struct scatterlist *scatterlist = sglist->scatterlist;
+	struct scatterlist *sg;
 	int i;
 
 	ipr_cmd->dma_use_sg = sglist->num_dma_sg;
@@ -3992,11 +3995,11 @@ static void ipr_build_ucode_ioadl(struct ipr_cmnd *ipr_cmd,
 	ioarcb->ioadl_len =
 		cpu_to_be32(sizeof(struct ipr_ioadl_desc) * ipr_cmd->dma_use_sg);
 
-	for (i = 0; i < ipr_cmd->dma_use_sg; i++) {
+	for_each_sg(scatterlist, sg, ipr_cmd->dma_use_sg, i) {
 		ioadl[i].flags_and_data_len =
-			cpu_to_be32(IPR_IOADL_FLAGS_WRITE | sg_dma_len(&scatterlist[i]));
+			cpu_to_be32(IPR_IOADL_FLAGS_WRITE | sg_dma_len(sg));
 		ioadl[i].address =
-			cpu_to_be32(sg_dma_address(&scatterlist[i]));
+			cpu_to_be32(sg_dma_address(sg));
 	}
 
 	ioadl[i-1].flags_and_data_len |=