From 5c17f87abb1a86eb4d2a108477e56389622cf195 Mon Sep 17 00:00:00 2001 From: Avri Altman Date: Wed, 20 Feb 2019 09:11:14 +0200 Subject: scsi: ufs-bsg: Allow reading descriptors Add this functionality, placing the descriptor being read in the actual data buffer in the bio. That is, for both read and write descriptors query upiu, we are using the job's request_payload. This in turn, is mapped back in user land to the applicable sg_io_v4 xferp: dout_xferp for write descriptor, and din_xferp for read descriptor. Signed-off-by: Avri Altman Reviewed-by: Evan Green Reviewed-by: Bean Huo Signed-off-by: Martin K. Petersen --- Documentation/scsi/ufs.txt | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'Documentation/scsi') diff --git a/Documentation/scsi/ufs.txt b/Documentation/scsi/ufs.txt index 78fe7cbfae48..1769f71c4c20 100644 --- a/Documentation/scsi/ufs.txt +++ b/Documentation/scsi/ufs.txt @@ -150,9 +150,14 @@ send SG_IO with the applicable sg_io_v4: if (dir == SG_DXFER_TO_DEV) { io_hdr_v4.dout_xfer_len = (uint32_t)byte_cnt; io_hdr_v4.dout_xferp = (uintptr_t)(__u64)buff; + } else { + io_hdr_v4.din_xfer_len = (uint32_t)byte_cnt; + io_hdr_v4.din_xferp = (uintptr_t)(__u64)buff; } -If you wish to write a descriptor, use the dout_xferp sg_io_v4. +If you wish to read or write a descriptor, use the appropriate xferp of +sg_io_v4. + UFS Specifications can be found at, UFS - http://www.jedec.org/sites/default/files/docs/JESD220.pdf -- cgit v1.2.3