diff options
Diffstat (limited to 'block/ll_rw_blk.c')
| -rw-r--r-- | block/ll_rw_blk.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 5ccec8aa964..3d0422f4845 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 |