diff options
| -rw-r--r-- | block/ll_rw_blk.c | 24 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
2 files changed, 25 insertions, 0 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 8b919940b2ab..14af36c5cdb2 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -760,6 +760,30 @@ void blk_queue_dma_alignment(struct request_queue *q, int mask) EXPORT_SYMBOL(blk_queue_dma_alignment); /** + * blk_queue_update_dma_alignment - update dma length and memory alignment + * @q: the request queue for the device + * @mask: alignment mask + * + * description: + * update required memory and length aligment for direct dma transactions. + * If the requested alignment is larger than the current alignment, then + * the current queue alignment is updated to the new value, otherwise it + * is left alone. The design of this is to allow multiple objects + * (driver, device, transport etc) to set their respective + * alignments without having them interfere. + * + **/ +void blk_queue_update_dma_alignment(struct request_queue *q, int mask) +{ + BUG_ON(mask > PAGE_SIZE); + + if (mask > q->dma_alignment) + q->dma_alignment = mask; +} + +EXPORT_SYMBOL(blk_queue_update_dma_alignment); + +/** * blk_queue_find_tag - find a request by its tag and queue * @q: The request queue for the device * @tag: The tag of the request diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d18ee67b40f8..81e99e516302 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -766,6 +766,7 @@ extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); extern void blk_queue_dma_alignment(struct request_queue *, int); +extern void blk_queue_update_dma_alignment(struct request_queue *, int); extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *); |