IDE: sg chaining support
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index aa06daf..2a3c8d4 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -45,6 +45,7 @@
#include <linux/hdreg.h>
#include <linux/ide.h>
#include <linux/bitops.h>
+#include <linux/scatterlist.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
@@ -263,6 +264,7 @@
{
ide_hwif_t *hwif = drive->hwif;
struct scatterlist *sg = hwif->sg_table;
+ struct scatterlist *cursg = hwif->cursg;
struct page *page;
#ifdef CONFIG_HIGHMEM
unsigned long flags;
@@ -270,8 +272,14 @@
unsigned int offset;
u8 *buf;
- page = sg[hwif->cursg].page;
- offset = sg[hwif->cursg].offset + hwif->cursg_ofs * SECTOR_SIZE;
+ cursg = hwif->cursg;
+ if (!cursg) {
+ cursg = sg;
+ hwif->cursg = sg;
+ }
+
+ page = cursg->page;
+ offset = cursg->offset + hwif->cursg_ofs * SECTOR_SIZE;
/* get the current page and offset */
page = nth_page(page, (offset >> PAGE_SHIFT));
@@ -285,8 +293,8 @@
hwif->nleft--;
hwif->cursg_ofs++;
- if ((hwif->cursg_ofs * SECTOR_SIZE) == sg[hwif->cursg].length) {
- hwif->cursg++;
+ if ((hwif->cursg_ofs * SECTOR_SIZE) == cursg->length) {
+ hwif->cursg = sg_next(hwif->cursg);
hwif->cursg_ofs = 0;
}
@@ -367,6 +375,8 @@
static void task_end_request(ide_drive_t *drive, struct request *rq, u8 stat)
{
+ HWIF(drive)->cursg = NULL;
+
if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
ide_task_t *task = rq->special;