diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-map.c | 20 | ||||
| -rw-r--r-- | block/blk-settings.c | 17 |
2 files changed, 30 insertions, 7 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index f5598322954d..4e17dfd0035d 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -43,6 +43,7 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq, void __user *ubuf, unsigned int len) { unsigned long uaddr; + unsigned int alignment; struct bio *bio, *orig_bio; int reading, ret; @@ -53,8 +54,8 @@ 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; - if (!(uaddr & queue_dma_alignment(q)) && - !(len & queue_dma_alignment(q))) + alignment = queue_dma_alignment(q) | q->dma_pad_mask; + if (!(uaddr & alignment) && !(len & alignment)) bio = bio_map_user(q, NULL, uaddr, len, reading); else bio = bio_copy_user(q, uaddr, len, reading); @@ -141,15 +142,20 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, /* * __blk_rq_map_user() copies the buffers if starting address - * or length isn't aligned. As the copied buffer is always - * page aligned, we know that there's enough room for padding. - * Extend the last bio and update rq->data_len accordingly. + * or length isn't aligned to dma_pad_mask. As the copied + * buffer is always page aligned, we know that there's enough + * room for padding. Extend the last bio and update + * rq->data_len accordingly. * * On unmap, bio_uncopy_user() will use unmodified * bio_map_data pointed to by bio->bi_private. */ - if (len & queue_dma_alignment(q)) { - unsigned int pad_len = (queue_dma_alignment(q) & ~len) + 1; + if (len & q->dma_pad_mask) { + unsigned int pad_len = (q->dma_pad_mask & ~len) + 1; + struct bio *bio = rq->biotail; + + bio->bi_io_vec[bio->bi_vcnt - 1].bv_len += pad_len; + bio->bi_size += pad_len; rq->extra_len += pad_len; } diff --git a/block/blk-settings.c b/block/blk-settings.c index da923fed1f2c..a9f37f530b15 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -293,6 +293,23 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) EXPORT_SYMBOL(blk_queue_stack_limits); /** + * blk_queue_dma_pad - set pad mask + * @q: the request queue for the device + * @mask: pad mask + * + * Set pad mask. Direct IO requests are padded to the mask specified. + * + * Appending pad buffer to a request modifies ->data_len such that it + * includes the pad buffer. The original requested data length can be + * obtained using blk_rq_raw_data_len(). + **/ +void blk_queue_dma_pad(struct request_queue *q, unsigned int mask) +{ + q->dma_pad_mask = mask; +} +EXPORT_SYMBOL(blk_queue_dma_pad); + +/** * blk_queue_dma_drain - Set up a drain buffer for excess dma. * @q: the request queue for the device * @dma_drain_needed: fn which returns non-zero if drain is necessary |