s390/dasd: Establish DMA alignment

linux-next commit c49ec585f24a ("iomap: add support for dma aligned
direct-io") changes the alignment requirement to come from the block
device rather than the block size, and the default alignment
requirement is 512-byte boundaries. Since DASD I/O has page
alignments for IDAW/TIDAW requests, let's override this value to
restore the expected behavior.

Make this change for both ECKD and DIAG disciplines, as they both
would fall into this category. Leave FBA alone, since it is always
comprised of 512-byte blocks.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20220804213926.3361574-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index e9edf3b6ed7c0002aa63eda3bfab5035b234d04c..94ee59864971e095c1508124efb54cb5babb4ac5 100644 (file)
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -639,6 +639,7 @@ static void dasd_diag_setup_blk_queue(struct dasd_block *block)
        /* With page sized segments each segment can be translated into one idaw/tidaw */
        blk_queue_max_segment_size(q, PAGE_SIZE);
        blk_queue_segment_boundary(q, PAGE_SIZE - 1);
+       blk_queue_dma_alignment(q, PAGE_SIZE - 1);
 }
 
 static int dasd_diag_pe_handler(struct dasd_device *device,

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 836838f7d6867ae6328ac4f9342eccee2e0a54c9..3cc93e2e4e15ab4e62ba50ba3420b2581c413973 100644 (file)
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -6626,6 +6626,7 @@ static void dasd_eckd_setup_blk_queue(struct dasd_block *block)
        /* With page sized segments each segment can be translated into one idaw/tidaw */
        blk_queue_max_segment_size(q, PAGE_SIZE);
        blk_queue_segment_boundary(q, PAGE_SIZE - 1);
+       blk_queue_dma_alignment(q, PAGE_SIZE - 1);
 }
 
 static struct ccw_driver dasd_eckd_driver = {