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nvme/nvme-fc: add transport SGL type

PATCH New James Smart 1 participant 3 messages Sep 7, 2017

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NVMe NVMe FC transport
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James Smart

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#0 lore raw

cover nvme/nvme-fc: add transport SGL type

These patches add the new transport-specific SGL type and updates the fc transport for its use of the type.

James Smart (2):
nvme: Add transport SGL definitions
nvme-fc: use transport-specific sgl format

 drivers/nvme/host/fc.c | 13 +++++++------
 include/linux/nvme.h   |  6 ++++++
 2 files changed, 13 insertions(+), 6 deletions(-)
Signature · 1 line
2.13.1
author
#1 lore raw

PATCH 1/2 nvme: Add transport SGL definitions

Add the sgl type code for Transport SGL Data Block Descriptor.

Add the sgl sub type code 0x0A, used by FC Transport.

Signed-off-by James Smart <james.smart at broadcom.com>
---
 include/linux/nvme.h | 6 ++++++
 1 file changed, 6 insertions(+)
include/linux/nvme.h +6 -0
index c46f42269021..823bf6f80dae 100644
@@ -471,12 +471,14 @@ enum nvme_opcode {
  *
  * @NVME_SGL_FMT_ADDRESS:     absolute address of the data block
  * @NVME_SGL_FMT_OFFSET:      relative offset of the in-capsule data block
+ * @NVME_SGL_FMT_TRANSPORT_A: transport defined format, value 0xA
  * @NVME_SGL_FMT_INVALIDATE:  RDMA transport specific remote invalidation
  *                            request subtype
  */
 enum {
 	NVME_SGL_FMT_ADDRESS		= 0x00,
 	NVME_SGL_FMT_OFFSET		= 0x01,
+	NVME_SGL_FMT_TRANSPORT_A	= 0x0A,
 	NVME_SGL_FMT_INVALIDATE		= 0x0f,
 };
 

@@ -490,12 +492,16 @@ enum {
  *
  * For struct nvme_keyed_sgl_desc:
  *   @NVME_KEY_SGL_FMT_DATA_DESC:	keyed data block descriptor
+ *
+ * Transport-specific SGL types:
+ *   @NVME_TRANSPORT_SGL_DATA_DESC:	Transport SGL data dlock descriptor
  */
 enum {
 	NVME_SGL_FMT_DATA_DESC		= 0x00,
 	NVME_SGL_FMT_SEG_DESC		= 0x02,
 	NVME_SGL_FMT_LAST_SEG_DESC	= 0x03,
 	NVME_KEY_SGL_FMT_DATA_DESC	= 0x04,
+	NVME_TRANSPORT_SGL_DATA_DESC	= 0x05,
 };
 
 struct nvme_sgl_desc {
Signature · 1 line
2.13.1
author
#2 lore raw

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

In reply to James Smart

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(-)
drivers/nvme/host/fc.c +7 -6
index d2e882c0f496..6e436987baae 100644
@@ -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;
Signature · 1 line
2.13.1