Use the scatterlist iterators and remove direct indexing of the scatterlist array. This way allows us to pre-allocate one small scatterlist, which can be chained with one runtime allocated scatterlist if the pre-allocated one isn't enough for the whole request. Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- drivers/scsi/ipr.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index 6d053e220153..383603973937 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -3915,22 +3915,22 @@ 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; @@ -3939,13 +3939,13 @@ 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; @@ -3966,6 +3966,7 @@ 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; @@ -3974,10 +3975,10 @@ 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); @@ -3997,6 +3998,7 @@ 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; @@ -4006,11 +4008,11 @@ 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 |= -- 2.20.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel