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From: Ming Lei <ming.lei@redhat.com>
To: linux-scsi@vger.kernel.org,
	"Martin K . Petersen" <martin.petersen@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>,
	Bart Van Assche <bvanassche@acm.org>,
	Hannes Reinecke <hare@suse.com>, Christoph Hellwig <hch@lst.de>,
	Jim Gill <jgill@vmware.com>, Cathy Avery <cavery@redhat.com>,
	"Ewan D . Milne" <emilne@redhat.com>,
	Brian King <brking@us.ibm.com>,
	James Smart <james.smart@broadcom.com>,
	"Juergen E . Fischer" <fischer@norbit.de>,
	Michael Schmitz <schmitzmic@gmail.com>,
	Finn Thain <fthain@telegraphics.com.au>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devel@driverdev.osuosl.org, linux-usb@vger.kernel.org,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Benjamin Block <bblock@linux.ibm.com>,
	Ming Lei <ming.lei@redhat.com>
Subject: [PATCH V4 05/16] scsi: ipr: use sg helper to operate scatterlist
Date: Mon, 17 Jun 2019 11:03:38 +0800
Message-ID: <20190617030349.26415-6-ming.lei@redhat.com> (raw)
In-Reply-To: <20190617030349.26415-1-ming.lei@redhat.com>

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@redhat.com>
---
 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


  parent reply index

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-17  3:03 [PATCH V4 00/16] " Ming Lei
2019-06-17  3:03 ` [PATCH V4 01/16] scsi: vmw_pscsi: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 02/16] scsi: advansys: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 03/16] scsi: lpfc: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 04/16] scsi: mvumi: " Ming Lei
2019-06-17  8:22   ` Christoph Hellwig
2019-06-17  3:03 ` Ming Lei [this message]
2019-06-17  8:24   ` [PATCH V4 05/16] scsi: ipr: " Christoph Hellwig
2019-06-17  8:50     ` Ming Lei
2019-06-17  3:03 ` [PATCH V4 06/16] scsi: pmcraid: " Ming Lei
2019-06-17  8:24   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 07/16] usb: image: microtek: " Ming Lei
2019-06-17  8:25   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 08/16] staging: unisys: visorhba: " Ming Lei
2019-06-17  8:25   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 09/16] staging: rtsx: " Ming Lei
2019-06-17  8:27   ` Christoph Hellwig
2019-06-17  9:15     ` Ming Lei
2019-06-17  9:24       ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 10/16] s390: zfcp_fc: " Ming Lei
2019-06-17  8:27   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 11/16] scsi: aha152x: " Ming Lei
2019-06-17  3:35   ` Finn Thain
2019-06-17 23:35     ` Finn Thain
2019-06-18  0:15       ` Ming Lei
2019-06-17  8:28   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 12/16] scsi: imm: " Ming Lei
2019-06-17  8:28   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 13/16] scsi: pcmcia: nsp_cs: " Ming Lei
2019-06-17  8:29   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 14/16] scsi: ppa: " Ming Lei
2019-06-17  8:29   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 15/16] scsi: wd33c93: " Ming Lei
2019-06-17  8:29   ` Christoph Hellwig
2019-06-17  3:03 ` [PATCH V4 16/16] NCR5380: Support chained sg lists Ming Lei
2019-06-17  8:30   ` Christoph Hellwig
2019-06-17 23:52 ` [PATCH V4 00/16] use sg helper to operate scatterlist Bart Van Assche

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