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[SCSI] ide-scsi: remove usage of sg_last()

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We want to remove sg_last(), it's a very expensive interface. So
keep track of number of sg entries in the sg list, instead of comparing
with the last entry.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2007-10-17 13:16:35 +02:00
parent 5804509e65
commit c79d88b7fa
1 changed files with 4 additions and 4 deletions
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8
drivers/scsi/ide-scsi.c
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@ -70,7 +70,7 @@ typedef struct idescsi_pc_s {
u8 *buffer; /* Data buffer */
u8 *current_position; /* Pointer into the above buffer */
struct scatterlist *sg; /* Scatter gather table */
struct scatterlist *last_sg; /* Last sg element */
unsigned int sg_cnt; /* Number of entries in sg */
int b_count; /* Bytes transferred from current entry */
struct scsi_cmnd *scsi_cmd; /* SCSI command */
void (*done)(struct scsi_cmnd *); /* Scsi completion routine */
@ -192,7 +192,7 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne
}
bcount -= count; pc->b_count += count;
if (pc->b_count == pc->sg->length) {
if (pc->sg == pc->last_sg)
if (!--pc->sg_cnt)
break;
pc->sg = sg_next(pc->sg);
pc->b_count = 0;
@ -229,7 +229,7 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign
}
bcount -= count; pc->b_count += count;
if (pc->b_count == pc->sg->length) {
if (pc->sg == pc->last_sg)
if (!--pc->sg_cnt)
break;
pc->sg = sg_next(pc->sg);
pc->b_count = 0;
@ -807,7 +807,7 @@ static int idescsi_queue (struct scsi_cmnd *cmd,
memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
pc->buffer = NULL;
pc->sg = scsi_sglist(cmd);
pc->last_sg = sg_last(pc->sg, scsi_sg_count(cmd));
pc->sg_cnt = scsi_sg_count(cmd);
pc->b_count = 0;
pc->request_transfer = pc->buffer_size = scsi_bufflen(cmd);
pc->scsi_cmd = cmd;