[PATCH 2/2] nvme: Expose cntrltype and dctype through sysfs.

[Martin Belanger]

From: Martin Belanger <martin.belanger at dell.com>

TP8010 introduces the Discovery Controller Type (dctype)
attribute. The dctype is returned in the response to the
Identify command. This patch exposes the dctype through
the sysfs. Since the dctype depends on the Controller
Type (cntrltype), another attribute of the Identify
response, the patch also exposes the cntrltype as well.

Signed-off-by: Martin Belanger <martin.belanger at dell.com>
---
 drivers/nvme/host/core.c | 35 +++++++++++++++++++++++++++++++++++
 drivers/nvme/host/nvme.h |  3 +++
 include/linux/nvme.h     | 10 +++++++++-
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 872c389dc6d3..c65d44fb65c4 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2992,6 +2992,9 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
 	ctrl->max_namespaces = le32_to_cpu(id->mnan);
 	ctrl->ctratt = le32_to_cpu(id->ctratt);
 
+	ctrl->cntrltype = id->cntrltype;
+	ctrl->dctype = id->dctype;
+
 	if (id->rtd3e) {
 		/* us -> s */
 		u32 transition_time = le32_to_cpu(id->rtd3e) / USEC_PER_SEC;
@@ -3525,6 +3528,34 @@ static ssize_t nvme_ctrl_fast_io_fail_tmo_store(struct device *dev,
 static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
 	nvme_ctrl_fast_io_fail_tmo_show, nvme_ctrl_fast_io_fail_tmo_store);
 
+static ssize_t nvme_ctrl_cntrltype_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	switch (ctrl->cntrltype) {
+	case NVME_CTRL_IO:	return sysfs_emit(buf, "io\n");
+	case NVME_CTRL_DISC:	return sysfs_emit(buf, "disc\n");
+	case NVME_CTRL_ADMIN:	return sysfs_emit(buf, "admin\n");
+	default:		return sysfs_emit(buf, "reserved\n");
+	}
+}
+static DEVICE_ATTR(cntrltype, S_IRUGO, nvme_ctrl_cntrltype_show, NULL);
+
+static ssize_t nvme_ctrl_dctype_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	switch (ctrl->dctype) {
+	case NVME_DCTYPE_NOT_REPORTED:	return sysfs_emit(buf, "nr\n");
+	case NVME_DCTYPE_DDC:		return sysfs_emit(buf, "ddc\n");
+	case NVME_DCTYPE_CDC:		return sysfs_emit(buf, "cdc\n");
+	default:			return sysfs_emit(buf, "reserved\n");
+	}
+}
+static DEVICE_ATTR(dctype, S_IRUGO, nvme_ctrl_dctype_show, NULL);
+
 static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_reset_controller.attr,
 	&dev_attr_rescan_controller.attr,
@@ -3546,6 +3577,8 @@ static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_reconnect_delay.attr,
 	&dev_attr_fast_io_fail_tmo.attr,
 	&dev_attr_kato.attr,
+	&dev_attr_cntrltype.attr,
+	&dev_attr_dctype.attr,
 	NULL
 };
 
@@ -3569,6 +3602,8 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
 		return 0;
 	if (a == &dev_attr_fast_io_fail_tmo.attr && !ctrl->opts)
 		return 0;
+	if (a == &dev_attr_dctype.attr && ctrl->cntrltype == NVME_CTRL_DISC)
+		return 0;
 
 	return a->mode;
 }
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index a162f6c6da6e..e30626c00791 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -349,6 +349,9 @@ struct nvme_ctrl {
 	unsigned long discard_page_busy;
 
 	struct nvme_fault_inject fault_inject;
+
+	enum nvme_ctrl_type cntrltype;
+	enum nvme_dctype dctype;
 };
 
 enum nvme_iopolicy {
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 855dd9b3e84b..af1494d83a52 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -43,6 +43,12 @@ enum nvme_ctrl_type {
 	NVME_CTRL_ADMIN	= 3,		/* Administrative controller */
 };
 
+enum nvme_dctype {
+	NVME_DCTYPE_NOT_REPORTED = 0,
+	NVME_DCTYPE_DDC = 1,		/* Direct Discovery Controller */
+	NVME_DCTYPE_CDC = 2,		/* Central Discovery Controller */
+};
+
 /* Address Family codes for Discovery Log Page entry ADRFAM field */
 enum {
 	NVMF_ADDR_FAMILY_PCI	= 0,	/* PCIe */
@@ -320,7 +326,9 @@ struct nvme_id_ctrl {
 	__le16			icdoff;
 	__u8			ctrattr;
 	__u8			msdbd;
-	__u8			rsvd1804[244];
+	__u8			rsvd1804[2];
+	__u8			dctype;
+	__u8			rsvd1807[241];
 	struct nvme_id_power_state	psd[32];
 	__u8			vs[1024];
 };
-- 
2.34.1