[PATCH 1/1] nvme: introduce nvme_transport_sgl_desc structure

[Max Gurtovoy]

Currently the tcp and fc transports use nvme_sgl_desc structure to
describe transport data blocks. Replace it with a new structure that
describes the Transport SGL Data Block according to the NVMe
specification.

Signed-off-by: Max Gurtovoy <mgurtovoy at nvidia.com>
---
 drivers/nvme/host/fc.c  |  6 ++----
 drivers/nvme/host/tcp.c |  6 ++----
 include/linux/nvme.h    | 14 +++++++++++---
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index f183f9fa03d0..adcf39a01d14 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2698,13 +2698,11 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	 * 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_TRANSPORT_SGL_DATA_DESC << 4) |
+	sqe->rw.dptr.tsgl.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;
+	sqe->rw.dptr.tsgl.length = cpu_to_le32(data_len);
 
 	if (!(op->flags & FCOP_FLAGS_AEN)) {
 		ret = nvme_fc_map_data(ctrl, op->rq, op);
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 34f4b3402f7c..c696b962c486 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2143,9 +2143,8 @@ static void nvme_tcp_free_ctrl(struct nvme_ctrl *nctrl)
 
 static void nvme_tcp_set_sg_null(struct nvme_command *c)
 {
-	struct nvme_sgl_desc *sg = &c->common.dptr.sgl;
+	struct nvme_transport_sgl_desc *sg = &c->common.dptr.tsgl;
 
-	sg->addr = 0;
 	sg->length = 0;
 	sg->type = (NVME_TRANSPORT_SGL_DATA_DESC << 4) |
 			NVME_SGL_FMT_TRANSPORT_A;
@@ -2164,9 +2163,8 @@ static void nvme_tcp_set_sg_inline(struct nvme_tcp_queue *queue,
 static void nvme_tcp_set_sg_host_data(struct nvme_command *c,
 		u32 data_len)
 {
-	struct nvme_sgl_desc *sg = &c->common.dptr.sgl;
+	struct nvme_transport_sgl_desc *sg = &c->common.dptr.tsgl;
 
-	sg->addr = 0;
 	sg->length = cpu_to_le32(data_len);
 	sg->type = (NVME_TRANSPORT_SGL_DATA_DESC << 4) |
 			NVME_SGL_FMT_TRANSPORT_A;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index edcbd60b88b9..ca0a17970c75 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -742,7 +742,7 @@ enum {
  *   @NVME_KEY_SGL_FMT_DATA_DESC:	keyed data block descriptor
  *
  * Transport-specific SGL types:
- *   @NVME_TRANSPORT_SGL_DATA_DESC:	Transport SGL data dlock descriptor
+ *   @NVME_TRANSPORT_SGL_DATA_DESC:	Transport SGL data block descriptor
  */
 enum {
 	NVME_SGL_FMT_DATA_DESC		= 0x00,
@@ -766,13 +766,21 @@ struct nvme_keyed_sgl_desc {
 	__u8	type;
 };
 
+struct nvme_transport_sgl_desc {
+	__u8	rsvd0[8];
+	__le32	length;
+	__u8	rsvd1[3];
+	__u8	type;
+};
+
 union nvme_data_ptr {
 	struct {
 		__le64	prp1;
 		__le64	prp2;
 	};
-	struct nvme_sgl_desc	sgl;
-	struct nvme_keyed_sgl_desc ksgl;
+	struct nvme_sgl_desc		sgl;
+	struct nvme_keyed_sgl_desc	ksgl;
+	struct nvme_transport_sgl_desc	tsgl;
 };
 
 /*
-- 
2.18.1