[PATCH 2/2] nvme-fc: use transport-specific sgl format

James Smart jsmart2021 at gmail.com
Thu Sep 7 13:20:24 PDT 2017


Sync with NVM Express spec change and FC-NVME 1.18.

FC transport sets SGL type to Transport SGL Data Block Descriptor and
subtype to transport-specific value 0x0A.

Removed the warn-on's on the PRP fields. They are unneeded. They were
to check for values from the upper layer that weren't set right, and
for the most part were fine. But, with Async events, which reuse the
same structure and 2nd time issued the SGL overlay converted them to
the Transport SGL values - the warn-on's were errantly firing.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index d2e882c0f496..6e436987baae 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1989,16 +1989,17 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	 * as well as those by FC-NVME spec.
 	 */
 	WARN_ON_ONCE(sqe->common.metadata);
-	WARN_ON_ONCE(sqe->common.dptr.prp1);
-	WARN_ON_ONCE(sqe->common.dptr.prp2);
 	sqe->common.flags |= NVME_CMD_SGL_METABUF;
 
 	/*
-	 * format SQE DPTR field per FC-NVME rules
-	 *    type=data block descr; subtype=offset;
-	 *    offset is currently 0.
+	 * format SQE DPTR field per FC-NVME rules:
+	 *    type=0x5     Transport SGL Data Block Descriptor
+	 *    subtype=0xA  Transport-specific value
+	 *    address=0
+	 *    length=length of the data series
 	 */
-	sqe->rw.dptr.sgl.type = NVME_SGL_FMT_OFFSET;
+	sqe->rw.dptr.sgl.type = (NVME_TRANSPORT_SGL_DATA_DESC << 4) |
+					NVME_SGL_FMT_TRANSPORT_A;
 	sqe->rw.dptr.sgl.length = cpu_to_le32(data_len);
 	sqe->rw.dptr.sgl.addr = 0;
 
-- 
2.13.1




More information about the Linux-nvme mailing list