TP2028 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.
TP4129 KATO Corrections and Clarifications defined CQT (Command Quiesce
Time) which is used along with KATO (Keep Alive Timeout) to set an upper
limite for attempting Cross-Controller Recovery.
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
---
drivers/nvme/host/core.c | 5 +++++
drivers/nvme/host/nvme.h | 11 +++++++++++
drivers/nvme/host/sysfs.c | 23 +++++++++++++++++++++++
3 files changed, 39 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index fa4181d7de73..aa007a7b9606 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3572,12 +3572,17 @@ 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);
ctrl->oaes = le32_to_cpu(id->oaes);
ctrl->wctemp = le16_to_cpu(id->wctemp);
ctrl->cctemp = le16_to_cpu(id->cctemp);
+ ctrl->cqt = le16_to_cpu(id->cqt);
atomic_set(&ctrl->abort_limit, id->acl + 1);
ctrl->vwc = id->vwc;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 102fae6a231c..5195a9abfadf 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -326,13 +326,17 @@ struct nvme_ctrl {
u32 max_zone_append;
#endif
u16 crdt[3];
+ u16 cqt;
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;
@@ -1218,4 +1222,11 @@ 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_recovery_timeout_ms(struct nvme_ctrl *ctrl)
+{
+ if (ctrl->ctratt & NVME_CTRL_ATTR_TBKAS)
+ return 3 * ctrl->kato * 1000 + ctrl->cqt;
+ return 2 * ctrl->kato * 1000 + ctrl->cqt;
+}
+
#endif /* _NVME_H */
diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 29430949ce2f..ae36249ad61e 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_uniquifier_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(uniquifier, S_IRUGO, nvme_sysfs_uniquifier_show, NULL);
+
+static ssize_t nvme_sysfs_random_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(random, S_IRUGO, nvme_sysfs_random_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_uniquifier.attr,
+ &dev_attr_random.attr,
&dev_attr_hostnqn.attr,
&dev_attr_hostid.attr,
&dev_attr_ctrl_loss_tmo.attr,
--
2.51.2On Tue, Nov 25, 2025 at 6:13 PM Mohamed Khalfella
<mkhalfella@purestorage.com> wrote:
>
> TP2028 Rapid path failure added new fileds to controller identify
TP8028
> 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.
>
> TP4129 KATO Corrections and Clarifications defined CQT (Command Quiesce
> Time) which is used along with KATO (Keep Alive Timeout) to set an upper
> limite for attempting Cross-Controller Recovery.
"limite" -> "limit"
>
> Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
> ---
> drivers/nvme/host/core.c | 5 +++++
> drivers/nvme/host/nvme.h | 11 +++++++++++
> drivers/nvme/host/sysfs.c | 23 +++++++++++++++++++++++
> 3 files changed, 39 insertions(+)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index fa4181d7de73..aa007a7b9606 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3572,12 +3572,17 @@ 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);
Seems like it would be good for the target & init to use the same
name for these fields. I have a preference for these over
instance_uniquifier and random because they are more concise, but
the preference is not strong.
> +
> ctrl->oacs = le16_to_cpu(id->oacs);
> ctrl->oncs = le16_to_cpu(id->oncs);
> ctrl->mtfa = le16_to_cpu(id->mtfa);
> ctrl->oaes = le32_to_cpu(id->oaes);
> ctrl->wctemp = le16_to_cpu(id->wctemp);
> ctrl->cctemp = le16_to_cpu(id->cctemp);
> + ctrl->cqt = le16_to_cpu(id->cqt);
>
> atomic_set(&ctrl->abort_limit, id->acl + 1);
> ctrl->vwc = id->vwc;
I cannot discern an ordering to the attributes set here. Any
particular reason, you placed cqt away from the others you added?
> diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
> index 29430949ce2f..ae36249ad61e 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_uniquifier_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(uniquifier, S_IRUGO, nvme_sysfs_uniquifier_show, NULL);
> +
> +static ssize_t nvme_sysfs_random_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(random, S_IRUGO, nvme_sysfs_random_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_uniquifier.attr,
> + &dev_attr_random.attr,
> &dev_attr_hostnqn.attr,
> &dev_attr_hostid.attr,
> &dev_attr_ctrl_loss_tmo.attr,
> --
> 2.51.2
>
These are the names used in the target code (uniquifer & random.
I'd rather have them match (identify structure will have spec's
abbreviations; ctrl & debug/sysfs for target & initiator either be
ciu/cirn or uniquifer/random.
But this is small stuff.
Reviewed-by: Randy Jennings <randyj@purestorage.com>
On Thu 2025-12-18 07:22:41 -0800, Randy Jennings wrote:
> On Tue, Nov 25, 2025 at 6:13 PM Mohamed Khalfella
> <mkhalfella@purestorage.com> wrote:
> >
> > TP2028 Rapid path failure added new fileds to controller identify
> TP8028
Fixed.
> > 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.
> >
> > TP4129 KATO Corrections and Clarifications defined CQT (Command Quiesce
> > Time) which is used along with KATO (Keep Alive Timeout) to set an upper
> > limite for attempting Cross-Controller Recovery.
> "limite" -> "limit"
Fixed.
> >
> > Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
> > ---
> > drivers/nvme/host/core.c | 5 +++++
> > drivers/nvme/host/nvme.h | 11 +++++++++++
> > drivers/nvme/host/sysfs.c | 23 +++++++++++++++++++++++
> > 3 files changed, 39 insertions(+)
> >
> > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> > index fa4181d7de73..aa007a7b9606 100644
> > --- a/drivers/nvme/host/core.c
> > +++ b/drivers/nvme/host/core.c
> > @@ -3572,12 +3572,17 @@ 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);
> Seems like it would be good for the target & init to use the same
> name for these fields. I have a preference for these over
> instance_uniquifier and random because they are more concise, but
> the preference is not strong.
The field names in the spec are concise, but they are also cryptic.
>
> > +
> > ctrl->oacs = le16_to_cpu(id->oacs);
> > ctrl->oncs = le16_to_cpu(id->oncs);
> > ctrl->mtfa = le16_to_cpu(id->mtfa);
> > ctrl->oaes = le32_to_cpu(id->oaes);
> > ctrl->wctemp = le16_to_cpu(id->wctemp);
> > ctrl->cctemp = le16_to_cpu(id->cctemp);
> > + ctrl->cqt = le16_to_cpu(id->cqt);
> >
> > atomic_set(&ctrl->abort_limit, id->acl + 1);
> > ctrl->vwc = id->vwc;
> I cannot discern an ordering to the attributes set here. Any
> particular reason, you placed cqt away from the others you added?
No reason. Moved ctrl->cqt initialization up with other fields.
>
> > diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
> > index 29430949ce2f..ae36249ad61e 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_uniquifier_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(uniquifier, S_IRUGO, nvme_sysfs_uniquifier_show, NULL);
> > +
> > +static ssize_t nvme_sysfs_random_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(random, S_IRUGO, nvme_sysfs_random_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_uniquifier.attr,
> > + &dev_attr_random.attr,
> > &dev_attr_hostnqn.attr,
> > &dev_attr_hostid.attr,
> > &dev_attr_ctrl_loss_tmo.attr,
> > --
> > 2.51.2
> >
>
> These are the names used in the target code (uniquifer & random.
> I'd rather have them match (identify structure will have spec's
> abbreviations; ctrl & debug/sysfs for target & initiator either be
> ciu/cirn or uniquifer/random.
I think it matters for sysfs attributes. I do not know the right thing
to do. Should we use spec names like "cirn" or call it "random"?
>
> But this is small stuff.
>
> Reviewed-by: Randy Jennings <randyj@purestorage.com>
On Wed 2025-12-31 14:26:39 -0800, Mohamed Khalfella wrote:
> On Thu 2025-12-18 07:22:41 -0800, Randy Jennings wrote:
> > On Tue, Nov 25, 2025 at 6:13 PM Mohamed Khalfella
> > <mkhalfella@purestorage.com> wrote:
> > >
> > > TP2028 Rapid path failure added new fileds to controller identify
> > TP8028
>
> Fixed.
>
> > > 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.
> > >
> > > TP4129 KATO Corrections and Clarifications defined CQT (Command Quiesce
> > > Time) which is used along with KATO (Keep Alive Timeout) to set an upper
> > > limite for attempting Cross-Controller Recovery.
> > "limite" -> "limit"
>
> Fixed.
>
> > >
> > > Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
> > > ---
> > > drivers/nvme/host/core.c | 5 +++++
> > > drivers/nvme/host/nvme.h | 11 +++++++++++
> > > drivers/nvme/host/sysfs.c | 23 +++++++++++++++++++++++
> > > 3 files changed, 39 insertions(+)
> > >
> > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> > > index fa4181d7de73..aa007a7b9606 100644
> > > --- a/drivers/nvme/host/core.c
> > > +++ b/drivers/nvme/host/core.c
> > > @@ -3572,12 +3572,17 @@ 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);
> > Seems like it would be good for the target & init to use the same
> > name for these fields. I have a preference for these over
> > instance_uniquifier and random because they are more concise, but
> > the preference is not strong.
>
> The field names in the spec are concise, but they are also cryptic.
>
> >
> > > +
> > > ctrl->oacs = le16_to_cpu(id->oacs);
> > > ctrl->oncs = le16_to_cpu(id->oncs);
> > > ctrl->mtfa = le16_to_cpu(id->mtfa);
> > > ctrl->oaes = le32_to_cpu(id->oaes);
> > > ctrl->wctemp = le16_to_cpu(id->wctemp);
> > > ctrl->cctemp = le16_to_cpu(id->cctemp);
> > > + ctrl->cqt = le16_to_cpu(id->cqt);
> > >
> > > atomic_set(&ctrl->abort_limit, id->acl + 1);
> > > ctrl->vwc = id->vwc;
> > I cannot discern an ordering to the attributes set here. Any
> > particular reason, you placed cqt away from the others you added?
>
> No reason. Moved ctrl->cqt initialization up with other fields.
>
> >
> > > diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
> > > index 29430949ce2f..ae36249ad61e 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_uniquifier_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(uniquifier, S_IRUGO, nvme_sysfs_uniquifier_show, NULL);
> > > +
> > > +static ssize_t nvme_sysfs_random_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(random, S_IRUGO, nvme_sysfs_random_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_uniquifier.attr,
> > > + &dev_attr_random.attr,
> > > &dev_attr_hostnqn.attr,
> > > &dev_attr_hostid.attr,
> > > &dev_attr_ctrl_loss_tmo.attr,
> > > --
> > > 2.51.2
> > >
> >
> > These are the names used in the target code (uniquifer & random.
> > I'd rather have them match (identify structure will have spec's
> > abbreviations; ctrl & debug/sysfs for target & initiator either be
> > ciu/cirn or uniquifer/random.
>
> I think it matters for sysfs attributes. I do not know the right thing
> to do. Should we use spec names like "cirn" or call it "random"?
Now I am thinking about it, I think sticking to the spec's abbreviations
makes more sense here. names like "random" and "uniquifier" in sysfs are
not descriptive enough. I changed struct member names, sysfs, and
debugfs file names to match the spec.
>
> >
> > But this is small stuff.
> >
> > Reviewed-by: Randy Jennings <randyj@purestorage.com>
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