diff options
| author | Keith Busch <kbusch@kernel.org> | 2022-06-10 22:58:22 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-06-27 15:29:11 +0300 |
| commit | 3850e13f2853a17c083eb00fad2c6da4fde0b41e (patch) | |
| tree | cdc879bb778abecd354f9a36798c026a4347031f | |
| parent | c58c0074c54c2e2bb3bb0d5a4d8896bb660cc8bc (diff) | |
block: export dma_alignment attribute
User space may want to know how to align their buffers to avoid
bouncing. Export the queue attribute.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-4-kbusch@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | Documentation/ABI/stable/sysfs-block | 9 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 7 |
2 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index e8797cd09aff..cd14ecb3c9a5 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -260,6 +260,15 @@ Description: for discards, and don't read this file. +What: /sys/block/<disk>/queue/dma_alignment +Date: May 2022 +Contact: linux-block@vger.kernel.org +Description: + Reports the alignment that user space addresses must have to be + used for raw block device access with O_DIRECT and other driver + specific passthrough mechanisms. + + What: /sys/block/<disk>/queue/fua Date: May 2018 Contact: linux-block@vger.kernel.org diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 9b905e9443e4..ec716ea26b92 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -274,6 +274,11 @@ static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page return queue_var_show(q->limits.virt_boundary_mask, page); } +static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_dma_alignment(q), page); +} + #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ static ssize_t \ queue_##name##_show(struct request_queue *q, char *page) \ @@ -606,6 +611,7 @@ QUEUE_RO_ENTRY(queue_dax, "dax"); QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout"); QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec"); QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask"); +QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment"); #ifdef CONFIG_BLK_DEV_THROTTLING_LOW QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time"); @@ -667,6 +673,7 @@ static struct attribute *queue_attrs[] = { &blk_throtl_sample_time_entry.attr, #endif &queue_virt_boundary_mask_entry.attr, + &queue_dma_alignment_entry.attr, NULL, }; |