[PATCH v3 06/21] nvme: Rapid Path Failure Recovery read controller identify fields

Mohamed Khalfella mkhalfella at purestorage.com
Fri Feb 13 20:25:07 PST 2026


TP8028 Rapid path failure added new fileds to controller identify
response. Read CIU (Controller Instance Uniquifier), CIRN (Controller
Instance Random Number), and CCRL (Cross-Controller Reset Limit) from
controller identify response. Expose CIU and CIRN as sysfs attributes
so the values can be used directrly by user if needed.

Signed-off-by: Mohamed Khalfella <mkhalfella at purestorage.com>
Reviewed-by: Hannes Reinecke <hare at suse.de>
---
 drivers/nvme/host/core.c  |  4 ++++
 drivers/nvme/host/nvme.h  | 10 ++++++++++
 drivers/nvme/host/sysfs.c | 23 +++++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 19b67cf5d550..8d26e27992fc 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3572,6 +3572,10 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
 	ctrl->crdt[1] = le16_to_cpu(id->crdt2);
 	ctrl->crdt[2] = le16_to_cpu(id->crdt3);
 
+	ctrl->ciu = id->ciu;
+	ctrl->cirn = le64_to_cpu(id->cirn);
+	atomic_set(&ctrl->ccr_limit, id->ccrl);
+
 	ctrl->oacs = le16_to_cpu(id->oacs);
 	ctrl->oncs = le16_to_cpu(id->oncs);
 	ctrl->mtfa = le16_to_cpu(id->mtfa);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 9a5f28c5103c..6984950b9aa8 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -328,11 +328,14 @@ struct nvme_ctrl {
 	u16 crdt[3];
 	u16 oncs;
 	u8 dmrl;
+	u8 ciu;
 	u32 dmrsl;
+	u64 cirn;
 	u16 oacs;
 	u16 sqsize;
 	u32 max_namespaces;
 	atomic_t abort_limit;
+	atomic_t ccr_limit;
 	u8 vwc;
 	u32 vs;
 	u32 sgls;
@@ -1225,4 +1228,11 @@ static inline bool nvme_multi_css(struct nvme_ctrl *ctrl)
 	return (ctrl->ctrl_config & NVME_CC_CSS_MASK) == NVME_CC_CSS_CSI;
 }
 
+static inline unsigned long nvme_fence_timeout_ms(struct nvme_ctrl *ctrl)
+{
+	if (ctrl->ctratt & NVME_CTRL_ATTR_TBKAS)
+		return 3 * ctrl->kato * 1000;
+	return 2 * ctrl->kato * 1000;
+}
+
 #endif /* _NVME_H */
diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 29430949ce2f..cd835dd2377f 100644
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -388,6 +388,27 @@ nvme_show_int_function(queue_count);
 nvme_show_int_function(sqsize);
 nvme_show_int_function(kato);
 
+static ssize_t nvme_sysfs_ciu_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%02x\n", ctrl->ciu);
+}
+static DEVICE_ATTR(ciu, S_IRUSR, nvme_sysfs_ciu_show, NULL);
+
+static ssize_t nvme_sysfs_cirn_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%016llx\n", ctrl->cirn);
+}
+static DEVICE_ATTR(cirn, S_IRUSR, nvme_sysfs_cirn_show, NULL);
+
+
 static ssize_t nvme_sysfs_delete(struct device *dev,
 				struct device_attribute *attr, const char *buf,
 				size_t count)
@@ -734,6 +755,8 @@ static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_numa_node.attr,
 	&dev_attr_queue_count.attr,
 	&dev_attr_sqsize.attr,
+	&dev_attr_ciu.attr,
+	&dev_attr_cirn.attr,
 	&dev_attr_hostnqn.attr,
 	&dev_attr_hostid.attr,
 	&dev_attr_ctrl_loss_tmo.attr,
-- 
2.52.0




More information about the Linux-nvme mailing list