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authorKeith Busch <kbusch@kernel.org>2022-06-10 12:58:29 -0700
committerJens Axboe <axboe@kernel.dk>2022-06-27 06:29:11 -0600
commitb1a000d3b8ec582da64bb644be633e5a0beffcbf (patch)
tree960fc00a20dbe8733f847f441205dae3be20b189 /include/linux/blkdev.h
parent5debd9691c3ac64c3acd6867c264ad38bbe48cdc (diff)
block: relax direct io memory alignmentblock-5.20-al
Use the address alignment requirements from the block_device for direct io instead of requiring addresses be aligned to the block size. User space can discover the alignment requirements from the dma_alignment queue attribute. User space can specify any hardware compatible DMA offset for each segment, but every segment length is still required to be a multiple of the block size. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220610195830.3574005-11-kbusch@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/blkdev.h')
-rw-r--r--include/linux/blkdev.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0b8bc1fe0b2c..886c44e97434 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -424,6 +424,11 @@ struct request_queue {
unsigned long nr_requests; /* Max # of requests */
unsigned int dma_pad_mask;
+ /*
+ * Drivers that set dma_alignment to less than 511 must be prepared to
+ * handle individual bvec's that are not a multiple of a SECTOR_SIZE
+ * due to possible offsets.
+ */
unsigned int dma_alignment;
#ifdef CONFIG_BLK_INLINE_ENCRYPTION