Hi Jens, Several embedded storage controllers need support for DMA segments that are smaller than the size of one virtual memory page. Hence this patch series. Please consider this patch series for the next merge window. Thanks, Bart. Changes compared to v2: - For SCSI drivers, only set flag QUEUE_FLAG_SUB_PAGE_SEGMENTS if necessary. - In the scsi_debug patch, sorted kernel module parameters alphabetically. Only set flag QUEUE_FLAG_SUB_PAGE_SEGMENTS if necessary. - Added a patch for the UFS Exynos driver that enables CONFIG_BLK_SUB_PAGE_SEGMENTS if the page size exceeds 4 KiB. Changes compared to v1: - Added a CONFIG variable that controls whether or not small segment support is enabled. - Improved patch descriptions. Bart Van Assche (9): block: Introduce QUEUE_FLAG_SUB_PAGE_SEGMENTS and CONFIG_BLK_SUB_PAGE_SEGMENTS block: Support configuring limits below the page size block: Support submitting passthrough requests with small segments block: Add support for filesystem requests and small segments block: Add support for small segments in blk_rq_map_user_iov() scsi_debug: Support configuring the maximum segment size null_blk: Support configuring the maximum segment size scsi: core: Set BLK_SUB_PAGE_SEGMENTS for small max_segment_size values scsi: ufs: exynos: Select CONFIG_BLK_SUB_PAGE_SEGMENTS for lage page sizes block/Kconfig | 9 +++++++ block/blk-map.c | 43 ++++++++++++++++++++++++++----- block/blk-merge.c | 6 +++-- block/blk-mq.c | 2 ++ block/blk-settings.c | 20 ++++++++------ block/blk.h | 22 +++++++++++----- drivers/block/null_blk/main.c | 21 ++++++++++++--- drivers/block/null_blk/null_blk.h | 1 + drivers/scsi/scsi_debug.c | 15 +++++++++++ drivers/scsi/scsi_lib.c | 3 +++ drivers/ufs/host/Kconfig | 1 + include/linux/blkdev.h | 7 +++++ 12 files changed, 125 insertions(+), 25 deletions(-)