[PATCH V5 04/16] scsi: mvumi: use sg helper to operate scatterlist

[Ming Lei]

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.

Reviewed-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Bart Van Assche <bvanassche at acm.org>
Reviewed-by: Ewan D. Milne <emilne at redhat.com>
Signed-off-by: Ming Lei <ming.lei at redhat.com>
---
 drivers/scsi/mvumi.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c
index a5410615edac..0022cd31500a 100644
--- a/drivers/scsi/mvumi.c
+++ b/drivers/scsi/mvumi.c
@@ -211,8 +211,7 @@ static int mvumi_make_sgl(struct mvumi_hba *mhba, struct scsi_cmnd *scmd,
 	unsigned int sgnum = scsi_sg_count(scmd);
 	dma_addr_t busaddr;
 
-	sg = scsi_sglist(scmd);
-	*sg_count = dma_map_sg(&mhba->pdev->dev, sg, sgnum,
+	*sg_count = dma_map_sg(&mhba->pdev->dev, scsi_sglist(scmd), sgnum,
 			       scmd->sc_data_direction);
 	if (*sg_count > mhba->max_sge) {
 		dev_err(&mhba->pdev->dev,
@@ -222,12 +221,12 @@ static int mvumi_make_sgl(struct mvumi_hba *mhba, struct scsi_cmnd *scmd,
 			     scmd->sc_data_direction);
 		return -1;
 	}
-	for (i = 0; i < *sg_count; i++) {
-		busaddr = sg_dma_address(&sg[i]);
+	scsi_for_each_sg(scmd, sg, *sg_count, i) {
+		busaddr = sg_dma_address(sg);
 		m_sg->baseaddr_l = cpu_to_le32(lower_32_bits(busaddr));
 		m_sg->baseaddr_h = cpu_to_le32(upper_32_bits(busaddr));
 		m_sg->flags = 0;
-		sgd_setsz(mhba, m_sg, cpu_to_le32(sg_dma_len(&sg[i])));
+		sgd_setsz(mhba, m_sg, cpu_to_le32(sg_dma_len(sg)));
 		if ((i + 1) == *sg_count)
 			m_sg->flags |= 1U << mhba->eot_flag;
 
-- 
2.20.1