lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

block: add blk_rq_aligned helper function

Browse Source 
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>
This commit is contained in:
FUJITA Tomonori
2008-08-28 15:05:58 +09:00
committed by Jens Axboe
parent 4d8ab62e08
commit 879040742c
2 changed files with 9 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/blkdev.h
View File

@ -899,6 +899,13 @@ static inline int queue_dma_alignment(struct request_queue *q)
return q ? q->dma_alignment : 511;
}
static inline int blk_rq_aligned(struct request_queue *q, void *addr,
unsigned int len)
{
unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
return !((unsigned long)addr & alignment) && !(len & alignment);
}
/* assumes size > 256 */
static inline unsigned int blksize_bits(unsigned int size)
{