openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

scsi: convert to using sg helpers 

This converts the SCSI mid layer to using the sg helpers for looking up
sg elements, instead of doing it manually.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2007-10-16 11:08:49 +02:00
parent f565913ef8
commit c6132da170
2 changed files with 15 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/scsi/scsi_lib.c
View File

@ -17,6 +17,7 @@
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/scatterlist.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
@ -289,14 +290,16 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
struct request_queue *q = rq->q;
int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
unsigned int data_len = bufflen, len, bytes, off;
struct scatterlist *sg;
struct page *page;
struct bio *bio = NULL;
int i, err, nr_vecs = 0;
for (i = 0; i < nsegs; i++) {
page = sgl[i].page;
off = sgl[i].offset;
len = sgl[i].length;
for_each_sg(sgl, sg, nsegs, i) {
page = sg->page;
off = sg->offset;
len = sg->length;
data_len += len;
while (len > 0 && data_len > 0) {
/*
@ -2193,18 +2196,19 @@ EXPORT_SYMBOL_GPL(scsi_target_unblock);
*
* Returns virtual address of the start of the mapped page
*/
void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
size_t *offset, size_t *len)
{
int i;
size_t sg_len = 0, len_complete = 0;
struct scatterlist *sg;
struct page *page;
WARN_ON(!irqs_disabled());
for (i = 0; i < sg_count; i++) {
for_each_sg(sgl, sg, sg_count, i) {
len_complete = sg_len; /* Complete sg-entries */
sg_len += sg[i].length;
sg_len += sg->length;
if (sg_len > *offset)
break;
}
@ -2218,10 +2222,10 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
}
/* Offset starting from the beginning of first page in this sg-entry */
*offset = *offset - len_complete + sg[i].offset;
*offset = *offset - len_complete + sg->offset;
/* Assumption: contiguous pages can be accessed as "page + i" */
page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
page = nth_page(sg->page, (*offset >> PAGE_SHIFT));
*offset &= ~PAGE_MASK;
/* Bytes in this sg-entry from *offset to the end of the page */

3
include/scsi/scsi_cmnd.h
View File

@ -5,6 +5,7 @@
#include <linux/list.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
struct request;
struct scatterlist;
@ -148,6 +149,6 @@ static inline int scsi_get_resid(struct scsi_cmnd *cmd)
}
#define scsi_for_each_sg(cmd, sg, nseg, __i) \
for (__i = 0, sg = scsi_sglist(cmd); __i < (nseg); __i++, (sg)++)
for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
#endif /* _SCSI_SCSI_CMND_H */