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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-08-28 15:05:58 +0900
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 08:56:11 +0200
commit879040742cf09f2360a9ac41846288707e4e567c (patch)
tree7768750efd0d8ef28a183f8cd781b0c878212795 /block/blk-map.c
parent4d8ab62e087d9300883b82c2662e73e6eef803a3 (diff)
downloadkernel-879040742cf09f2360a9ac41846288707e4e567c.tar.gz
block: add blk_rq_aligned helper function
This adds blk_rq_aligned helper function to see if alignment and padding requirement is satisfied for DMA transfer. This also converts blk_rq_map_kern and __blk_rq_map_user to use the helper function. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-map.c')
-rw-r--r--block/blk-map.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index dad6a2907835..572140cda5ff 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -45,7 +45,6 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
unsigned int len, gfp_t gfp_mask)
{
unsigned long uaddr;
- unsigned int alignment;
struct bio *bio, *orig_bio;
int reading, ret;
@@ -56,8 +55,7 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
* direct dma. else, set up kernel bounce buffers
*/
uaddr = (unsigned long) ubuf;
- alignment = queue_dma_alignment(q) | q->dma_pad_mask;
- if (!(uaddr & alignment) && !(len & alignment) && !map_data)
+ if (blk_rq_aligned(q, ubuf, len) && !map_data)
bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
else
bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask);
@@ -274,8 +272,6 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
unsigned int len, gfp_t gfp_mask)
{
- unsigned long kaddr;
- unsigned int alignment;
int reading = rq_data_dir(rq) == READ;
int do_copy = 0;
struct bio *bio;
@@ -285,11 +281,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
if (!len || !kbuf)
return -EINVAL;
- kaddr = (unsigned long)kbuf;
- alignment = queue_dma_alignment(q) | q->dma_pad_mask;
- do_copy = ((kaddr & alignment) || (len & alignment) ||
- object_is_on_stack(kbuf));
-
+ do_copy = !blk_rq_aligned(q, kbuf, len) || object_is_on_stack(kbuf);
if (do_copy)
bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
else