[PATCH V5 3/6] nvmet: add NVM command set identifier support

[Chaitanya Kulkarni]

NVMe TP 4056 allows controller to support different command sets.
NVMeoF target currently only supports namespaces that contain
traditional logical blocks that may be randomly read and written. In
some applications there is value in exposing namespaces that contain
logical blocks that have special access rules (e.g. sequentially write
required namespace such as Zoned Namespace (ZNS)).

In order to support the Zoned Block Devices (ZBD) backend, controller
needs to have support for ZNS Command Set Identifier (CSI).

In this preparation patch we adjust the code such that it can now
support different command sets. We update the namespace data
structure to store the CSI value which defaults to NVME_CSI_NVM
which represents traditional logical blocks namespace type.

The CSI support is required to implement the ZBD backend over NVMe ZNS
interface, since ZNS commands belongs to different command set than
the default one.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
---
 drivers/nvme/target/admin-cmd.c | 33 ++++++++++++++++++++-------------
 drivers/nvme/target/core.c      | 13 ++++++++++++-
 drivers/nvme/target/nvmet.h     |  1 +
 3 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 74620240ac47..f4c0f3aca485 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -176,19 +176,26 @@ static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
 	if (!log)
 		goto out;
 
-	log->acs[nvme_admin_get_log_page]	= cpu_to_le32(1 << 0);
-	log->acs[nvme_admin_identify]		= cpu_to_le32(1 << 0);
-	log->acs[nvme_admin_abort_cmd]		= cpu_to_le32(1 << 0);
-	log->acs[nvme_admin_set_features]	= cpu_to_le32(1 << 0);
-	log->acs[nvme_admin_get_features]	= cpu_to_le32(1 << 0);
-	log->acs[nvme_admin_async_event]	= cpu_to_le32(1 << 0);
-	log->acs[nvme_admin_keep_alive]		= cpu_to_le32(1 << 0);
-
-	log->iocs[nvme_cmd_read]		= cpu_to_le32(1 << 0);
-	log->iocs[nvme_cmd_write]		= cpu_to_le32(1 << 0);
-	log->iocs[nvme_cmd_flush]		= cpu_to_le32(1 << 0);
-	log->iocs[nvme_cmd_dsm]			= cpu_to_le32(1 << 0);
-	log->iocs[nvme_cmd_write_zeroes]	= cpu_to_le32(1 << 0);
+	switch (req->cmd->get_log_page.csi) {
+	case NVME_CSI_NVM:
+		log->acs[nvme_admin_get_log_page]	= cpu_to_le32(1 << 0);
+		log->acs[nvme_admin_identify]		= cpu_to_le32(1 << 0);
+		log->acs[nvme_admin_abort_cmd]		= cpu_to_le32(1 << 0);
+		log->acs[nvme_admin_set_features]	= cpu_to_le32(1 << 0);
+		log->acs[nvme_admin_get_features]	= cpu_to_le32(1 << 0);
+		log->acs[nvme_admin_async_event]	= cpu_to_le32(1 << 0);
+		log->acs[nvme_admin_keep_alive]		= cpu_to_le32(1 << 0);
+
+		log->iocs[nvme_cmd_read]		= cpu_to_le32(1 << 0);
+		log->iocs[nvme_cmd_write]		= cpu_to_le32(1 << 0);
+		log->iocs[nvme_cmd_flush]		= cpu_to_le32(1 << 0);
+		log->iocs[nvme_cmd_dsm]			= cpu_to_le32(1 << 0);
+		log->iocs[nvme_cmd_write_zeroes]	= cpu_to_le32(1 << 0);
+		break;
+	default:
+		status = NVME_SC_INVALID_LOG_PAGE;
+		break;
+	}
 
 	status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
 
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 8ce4d59cc9e7..672e4009f8d6 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -681,6 +681,7 @@ struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 
 	uuid_gen(&ns->uuid);
 	ns->buffered_io = false;
+	ns->csi = NVME_CSI_NVM;
 
 	return ns;
 }
@@ -1103,6 +1104,16 @@ static inline u8 nvmet_cc_iocqes(u32 cc)
 	return (cc >> NVME_CC_IOCQES_SHIFT) & 0xf;
 }
 
+static inline bool nvmet_cc_css_check(u8 cc_css)
+{
+	switch (cc_css <<= NVME_CC_CSS_SHIFT) {
+	case NVME_CC_CSS_NVM:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
 {
 	lockdep_assert_held(&ctrl->lock);
@@ -1111,7 +1122,7 @@ static void nvmet_start_ctrl(struct nvmet_ctrl *ctrl)
 	    nvmet_cc_iocqes(ctrl->cc) != NVME_NVM_IOCQES ||
 	    nvmet_cc_mps(ctrl->cc) != 0 ||
 	    nvmet_cc_ams(ctrl->cc) != 0 ||
-	    nvmet_cc_css(ctrl->cc) != 0) {
+	    !nvmet_cc_css_check(nvmet_cc_css(ctrl->cc))) {
 		ctrl->csts = NVME_CSTS_CFS;
 		return;
 	}
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 4cb4cdae858c..0360594abd93 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -81,6 +81,7 @@ struct nvmet_ns {
 	struct pci_dev		*p2p_dev;
 	int			pi_type;
 	int			metadata_size;
+	u8			csi;
 };
 
 static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
-- 
2.22.1