diff options
| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-07-04 09:30:03 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-07-04 09:52:13 +0200 |
| commit | 27f8221af406e43b529a5425bc99c9b1e9bdf521 (patch) | |
| tree | 6e847b9359327449b77d4b6350cc9d44fd9208b6 | |
| parent | 2610324fcacf38a24b630090ebcb802538763187 (diff) | |
block: add blk_queue_update_dma_pad
This adds blk_queue_update_dma_pad to prevent LLDs from overwriting
the dma pad mask wrongly (we added blk_queue_update_dma_alignment due
to the same reason).
This also converts libata to use blk_queue_update_dma_pad instead of
blk_queue_dma_pad.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| -rw-r--r-- | block/blk-settings.c | 24 | ||||
| -rw-r--r-- | drivers/ata/libata-scsi.c | 3 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
3 files changed, 23 insertions, 5 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 8dd86418f35..dfc77012843 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -302,11 +302,10 @@ EXPORT_SYMBOL(blk_queue_stack_limits); * @q: the request queue for the device * @mask: pad mask * - * Set pad mask. Direct IO requests are padded to the mask specified. + * Set dma pad mask. * - * 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(). + * Appending pad buffer to a request modifies the last entry of a + * scatter list such that it includes the pad buffer. **/ void blk_queue_dma_pad(struct request_queue *q, unsigned int mask) { @@ -315,6 +314,23 @@ void blk_queue_dma_pad(struct request_queue *q, unsigned int mask) EXPORT_SYMBOL(blk_queue_dma_pad); /** + * blk_queue_update_dma_pad - update pad mask + * @q: the request queue for the device + * @mask: pad mask + * + * Update dma pad mask. + * + * Appending pad buffer to a request modifies the last entry of a + * scatter list such that it includes the pad buffer. + **/ +void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask) +{ + if (mask > q->dma_pad_mask) + q->dma_pad_mask = mask; +} +EXPORT_SYMBOL(blk_queue_update_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 diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 57a43649a46..499ccc628d8 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -885,7 +885,8 @@ static int ata_scsi_dev_config(struct scsi_device *sdev, /* set the min alignment and padding */ blk_queue_update_dma_alignment(sdev->request_queue, ATA_DMA_PAD_SZ - 1); - blk_queue_dma_pad(sdev->request_queue, ATA_DMA_PAD_SZ - 1); + blk_queue_update_dma_pad(sdev->request_queue, + ATA_DMA_PAD_SZ - 1); /* configure draining */ buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e04c4ac8a7c..1ffd8bfdc4c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -776,6 +776,7 @@ extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); extern void blk_queue_hardsect_size(struct request_queue *, unsigned short); extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b); extern void blk_queue_dma_pad(struct request_queue *, unsigned int); +extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int); extern int blk_queue_dma_drain(struct request_queue *q, dma_drain_needed_fn *dma_drain_needed, void *buf, unsigned int size); |