Commit 347e1d39 authored by Changpeng Liu's avatar Changpeng Liu Committed by Tomasz Zawadzki
Browse files

nvme: update the comments about using hardware SGL 



Change-Id: I60d2b63d650bc73d2548f8b35a6a10d5334c9207
Signed-off-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/1258


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent 86c4d33f

lib/nvme/nvme_pcie.c

+9 −4
Original line number Diff line number Diff line
@@ -1927,7 +1927,9 @@ nvme_pcie_qpair_build_contig_hw_sgl_request(struct spdk_nvme_qpair *qpair, struc 
		req->cmd.dptr.sgl1.address = tr->u.sgl[0].address;

		req->cmd.dptr.sgl1.unkeyed.length = tr->u.sgl[0].unkeyed.length;

	} else {

		/* For now we can only support 1 SGL segment in NVMe controller */

		/* SPDK NVMe driver supports only 1 SGL segment for now, it is enough because

		 *  NVME_MAX_SGL_DESCRIPTORS * 16 is less than one page.

		 */

		req->cmd.dptr.sgl1.unkeyed.type = SPDK_NVME_SGL_TYPE_LAST_SEGMENT;

		req->cmd.dptr.sgl1.address = tr->prp_sgl_bus_addr;

		req->cmd.dptr.sgl1.unkeyed.length = nseg * sizeof(struct spdk_nvme_sgl_descriptor);
@@ -2019,7 +2021,9 @@ nvme_pcie_qpair_build_hw_sgl_request(struct spdk_nvme_qpair *qpair, struct nvme_ 
		req->cmd.dptr.sgl1.address = tr->u.sgl[0].address;

		req->cmd.dptr.sgl1.unkeyed.length = tr->u.sgl[0].unkeyed.length;

	} else {

		/* For now we can only support 1 SGL segment in NVMe controller */

		/* SPDK NVMe driver supports only 1 SGL segment for now, it is enough because

		 *  NVME_MAX_SGL_DESCRIPTORS * 16 is less than one page.

		 */

		req->cmd.dptr.sgl1.unkeyed.type = SPDK_NVME_SGL_TYPE_LAST_SEGMENT;

		req->cmd.dptr.sgl1.address = tr->prp_sgl_bus_addr;

		req->cmd.dptr.sgl1.unkeyed.length = nseg * sizeof(struct spdk_nvme_sgl_descriptor);
@@ -2142,8 +2146,9 @@ nvme_pcie_qpair_submit_request(struct spdk_nvme_qpair *qpair, struct nvme_reques 
		rc = 0;

	} else {

		payload_type = nvme_payload_type(&req->payload);

		/* Some NVME drives can't handle SGL request submitted to the admin qpair

		 * even if they report SGL support */

		/* According to the specification, PRPs shall be used for all

		 *  Admin commands for NVMe over PCIe implementations.

		 */

		sgl_supported = (ctrlr->flags & SPDK_NVME_CTRLR_SGL_SUPPORTED) != 0 &&

				!nvme_qpair_is_admin_queue(qpair);

		rc = g_nvme_pcie_build_req_table[payload_type][sgl_supported](qpair, req, tr);