Using these attributes region label is added/deleted into LSA. These
attributes are called from userspace (ndctl) after region creation.
Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
---
Documentation/ABI/testing/sysfs-bus-cxl | 22 +++++++
drivers/cxl/core/pmem_region.c | 88 +++++++++++++++++++++++++
drivers/cxl/cxl.h | 7 ++
3 files changed, 117 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index c80a1b5a03db..011a5e8d354f 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -624,3 +624,25 @@ Description:
The count is persistent across power loss and wraps back to 0
upon overflow. If this file is not present, the device does not
have the necessary support for dirty tracking.
+
+
+What: /sys/bus/cxl/devices/regionZ/pmem_regionZ/region_label_update
+Date: Jan, 2026
+KernelVersion: v6.19
+Contact: linux-cxl@vger.kernel.org
+Description:
+ (RW) Write a boolean 'true' string value to this attribute to
+ update cxl region information into LSA as region label. It is
+ used to update cxl region information saved during cxl region
+ creation into LSA. This attribute must be written last during
+ cxl region creation. Reading this attribute indicates whether
+ the region label is active or not.
+
+
+What: /sys/bus/cxl/devices/regionZ/pmem_regionZ/region_label_delete
+Date: Jan, 2026
+KernelVersion: v6.19
+Contact: linux-cxl@vger.kernel.org
+Description:
+ (WO) When a boolean 'true' is written to this attribute then
+ pmem_region driver deletes cxl region label from LSA.
diff --git a/drivers/cxl/core/pmem_region.c b/drivers/cxl/core/pmem_region.c
index dcaab59108fd..53d3d81e9676 100644
--- a/drivers/cxl/core/pmem_region.c
+++ b/drivers/cxl/core/pmem_region.c
@@ -29,8 +29,96 @@ static void cxl_pmem_region_release(struct device *dev)
kfree(cxlr_pmem);
}
+static ssize_t region_label_update_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
+ struct cxl_region *cxlr = cxlr_pmem->cxlr;
+ ssize_t rc;
+ bool update;
+
+ rc = kstrtobool(buf, &update);
+ if (rc)
+ return rc;
+
+ ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
+ if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
+ return rc;
+
+ /* Region not yet committed */
+ if (update && cxlr && cxlr->params.state != CXL_CONFIG_COMMIT) {
+ dev_dbg(dev, "region not committed, can't update into LSA\n");
+ return -ENXIO;
+ }
+
+ if (!cxlr || !cxlr->cxlr_pmem || !cxlr->cxlr_pmem->nd_region)
+ return 0;
+
+ rc = nd_region_label_update(cxlr->cxlr_pmem->nd_region);
+ if (rc)
+ return rc;
+
+ cxlr->params.state_region_label = CXL_REGION_LABEL_ACTIVE;
+
+ return len;
+}
+
+static ssize_t region_label_update_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
+ struct cxl_region *cxlr = cxlr_pmem->cxlr;
+ struct cxl_region_params *p = &cxlr->params;
+ ssize_t rc;
+
+ ACQUIRE(rwsem_read_intr, rwsem)(&cxl_rwsem.region);
+ if ((rc = ACQUIRE_ERR(rwsem_read_intr, &rwsem)))
+ return rc;
+
+ return sysfs_emit(buf, "%d\n", p->state_region_label);
+}
+static DEVICE_ATTR_RW(region_label_update);
+
+static ssize_t region_label_delete_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
+ struct cxl_region *cxlr = cxlr_pmem->cxlr;
+ ssize_t rc;
+
+ ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
+ if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
+ return rc;
+
+ if (!cxlr && !cxlr->cxlr_pmem && !cxlr->cxlr_pmem->nd_region)
+ return 0;
+
+ rc = nd_region_label_delete(cxlr->cxlr_pmem->nd_region);
+ if (rc)
+ return rc;
+
+ cxlr->params.state_region_label = CXL_REGION_LABEL_INACTIVE;
+
+ return len;
+}
+static DEVICE_ATTR_WO(region_label_delete);
+
+static struct attribute *cxl_pmem_region_attrs[] = {
+ &dev_attr_region_label_update.attr,
+ &dev_attr_region_label_delete.attr,
+ NULL
+};
+
+static struct attribute_group cxl_pmem_region_group = {
+ .attrs = cxl_pmem_region_attrs,
+};
+
static const struct attribute_group *cxl_pmem_region_attribute_groups[] = {
&cxl_base_attribute_group,
+ &cxl_pmem_region_group,
NULL
};
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 6ac3b40cb5ff..8c76c4a981bf 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -473,9 +473,15 @@ enum cxl_config_state {
CXL_CONFIG_COMMIT,
};
+enum region_label_state {
+ CXL_REGION_LABEL_INACTIVE,
+ CXL_REGION_LABEL_ACTIVE,
+};
+
/**
* struct cxl_region_params - region settings
* @state: allow the driver to lockdown further parameter changes
+ * @state: region label state
* @uuid: unique id for persistent regions
* @interleave_ways: number of endpoints in the region
* @interleave_granularity: capacity each endpoint contributes to a stripe
@@ -488,6 +494,7 @@ enum cxl_config_state {
*/
struct cxl_region_params {
enum cxl_config_state state;
+ enum region_label_state state_region_label;
uuid_t uuid;
int interleave_ways;
int interleave_granularity;
--
2.34.1On Fri, 9 Jan 2026 18:14:35 +0530
Neeraj Kumar <s.neeraj@samsung.com> wrote:
> Using these attributes region label is added/deleted into LSA. These
> attributes are called from userspace (ndctl) after region creation.
>
> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
One wrong field name.
With that and the version number updated as Dave pointed out
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 6ac3b40cb5ff..8c76c4a981bf 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> /**
> * struct cxl_region_params - region settings
> * @state: allow the driver to lockdown further parameter changes
> + * @state: region label state
wrong name.
Run scripts/kernel-doc over files you add documentation to and it'll
tell you when you get anything like this wrong.
> * @uuid: unique id for persistent regions
> * @interleave_ways: number of endpoints in the region
> * @interleave_granularity: capacity each endpoint contributes to a stripe
> @@ -488,6 +494,7 @@ enum cxl_config_state {
> */
> struct cxl_region_params {
> enum cxl_config_state state;
> + enum region_label_state state_region_label;
> uuid_t uuid;
> int interleave_ways;
> int interleave_granularity;
On 15/01/26 06:21PM, Jonathan Cameron wrote:
>On Fri, 9 Jan 2026 18:14:35 +0530
>Neeraj Kumar <s.neeraj@samsung.com> wrote:
>
>> Using these attributes region label is added/deleted into LSA. These
>> attributes are called from userspace (ndctl) after region creation.
>>
>> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
>One wrong field name.
>
>With that and the version number updated as Dave pointed out
>Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Thanks Jonathan for RB tag.
>
>
>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
>> index 6ac3b40cb5ff..8c76c4a981bf 100644
>> --- a/drivers/cxl/cxl.h
>> +++ b/drivers/cxl/cxl.h
>
>> /**
>> * struct cxl_region_params - region settings
>> * @state: allow the driver to lockdown further parameter changes
>> + * @state: region label state
>
>wrong name.
Fixed it in V6
>
>Run scripts/kernel-doc over files you add documentation to and it'll
>tell you when you get anything like this wrong.
I ran it but its not showing any error and displaying the wrong name
only.
Regards,
Neeraj
>
>> * @uuid: unique id for persistent regions
>> * @interleave_ways: number of endpoints in the region
>> * @interleave_granularity: capacity each endpoint contributes to a stripe
>> @@ -488,6 +494,7 @@ enum cxl_config_state {
>> */
>> struct cxl_region_params {
>> enum cxl_config_state state;
>> + enum region_label_state state_region_label;
>> uuid_t uuid;
>> int interleave_ways;
>> int interleave_granularity;
>
On 1/9/26 5:44 AM, Neeraj Kumar wrote:
> Using these attributes region label is added/deleted into LSA. These
> attributes are called from userspace (ndctl) after region creation.
>
> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
You'll need to update the KernelVersion to v7.0.
> ---
> Documentation/ABI/testing/sysfs-bus-cxl | 22 +++++++
> drivers/cxl/core/pmem_region.c | 88 +++++++++++++++++++++++++
> drivers/cxl/cxl.h | 7 ++
> 3 files changed, 117 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index c80a1b5a03db..011a5e8d354f 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -624,3 +624,25 @@ Description:
> The count is persistent across power loss and wraps back to 0
> upon overflow. If this file is not present, the device does not
> have the necessary support for dirty tracking.
> +
> +
> +What: /sys/bus/cxl/devices/regionZ/pmem_regionZ/region_label_update
> +Date: Jan, 2026
> +KernelVersion: v6.19
> +Contact: linux-cxl@vger.kernel.org
> +Description:
> + (RW) Write a boolean 'true' string value to this attribute to
> + update cxl region information into LSA as region label. It is
> + used to update cxl region information saved during cxl region
> + creation into LSA. This attribute must be written last during
> + cxl region creation. Reading this attribute indicates whether
> + the region label is active or not.
> +
> +
> +What: /sys/bus/cxl/devices/regionZ/pmem_regionZ/region_label_delete
> +Date: Jan, 2026
> +KernelVersion: v6.19
> +Contact: linux-cxl@vger.kernel.org
> +Description:
> + (WO) When a boolean 'true' is written to this attribute then
> + pmem_region driver deletes cxl region label from LSA.
> diff --git a/drivers/cxl/core/pmem_region.c b/drivers/cxl/core/pmem_region.c
> index dcaab59108fd..53d3d81e9676 100644
> --- a/drivers/cxl/core/pmem_region.c
> +++ b/drivers/cxl/core/pmem_region.c
> @@ -29,8 +29,96 @@ static void cxl_pmem_region_release(struct device *dev)
> kfree(cxlr_pmem);
> }
>
> +static ssize_t region_label_update_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
> + struct cxl_region *cxlr = cxlr_pmem->cxlr;
> + ssize_t rc;
> + bool update;
> +
> + rc = kstrtobool(buf, &update);
> + if (rc)
> + return rc;
> +
> + ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
> + if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
> + return rc;
> +
> + /* Region not yet committed */
> + if (update && cxlr && cxlr->params.state != CXL_CONFIG_COMMIT) {
> + dev_dbg(dev, "region not committed, can't update into LSA\n");
> + return -ENXIO;
> + }
> +
> + if (!cxlr || !cxlr->cxlr_pmem || !cxlr->cxlr_pmem->nd_region)
> + return 0;
> +
> + rc = nd_region_label_update(cxlr->cxlr_pmem->nd_region);
> + if (rc)
> + return rc;
> +
> + cxlr->params.state_region_label = CXL_REGION_LABEL_ACTIVE;
> +
> + return len;
> +}
> +
> +static ssize_t region_label_update_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
> + struct cxl_region *cxlr = cxlr_pmem->cxlr;
> + struct cxl_region_params *p = &cxlr->params;
> + ssize_t rc;
> +
> + ACQUIRE(rwsem_read_intr, rwsem)(&cxl_rwsem.region);
> + if ((rc = ACQUIRE_ERR(rwsem_read_intr, &rwsem)))
> + return rc;
> +
> + return sysfs_emit(buf, "%d\n", p->state_region_label);
> +}
> +static DEVICE_ATTR_RW(region_label_update);
> +
> +static ssize_t region_label_delete_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct cxl_pmem_region *cxlr_pmem = to_cxl_pmem_region(dev);
> + struct cxl_region *cxlr = cxlr_pmem->cxlr;
> + ssize_t rc;
> +
> + ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
> + if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
> + return rc;
> +
> + if (!cxlr && !cxlr->cxlr_pmem && !cxlr->cxlr_pmem->nd_region)
> + return 0;
> +
> + rc = nd_region_label_delete(cxlr->cxlr_pmem->nd_region);
> + if (rc)
> + return rc;
> +
> + cxlr->params.state_region_label = CXL_REGION_LABEL_INACTIVE;
> +
> + return len;
> +}
> +static DEVICE_ATTR_WO(region_label_delete);
> +
> +static struct attribute *cxl_pmem_region_attrs[] = {
> + &dev_attr_region_label_update.attr,
> + &dev_attr_region_label_delete.attr,
> + NULL
> +};
> +
> +static struct attribute_group cxl_pmem_region_group = {
> + .attrs = cxl_pmem_region_attrs,
> +};
> +
> static const struct attribute_group *cxl_pmem_region_attribute_groups[] = {
> &cxl_base_attribute_group,
> + &cxl_pmem_region_group,
> NULL
> };
>
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 6ac3b40cb5ff..8c76c4a981bf 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -473,9 +473,15 @@ enum cxl_config_state {
> CXL_CONFIG_COMMIT,
> };
>
> +enum region_label_state {
> + CXL_REGION_LABEL_INACTIVE,
> + CXL_REGION_LABEL_ACTIVE,
> +};
> +
> /**
> * struct cxl_region_params - region settings
> * @state: allow the driver to lockdown further parameter changes
> + * @state: region label state
> * @uuid: unique id for persistent regions
> * @interleave_ways: number of endpoints in the region
> * @interleave_granularity: capacity each endpoint contributes to a stripe
> @@ -488,6 +494,7 @@ enum cxl_config_state {
> */
> struct cxl_region_params {
> enum cxl_config_state state;
> + enum region_label_state state_region_label;
> uuid_t uuid;
> int interleave_ways;
> int interleave_granularity;
On 14/01/26 10:00AM, Dave Jiang wrote: > > >On 1/9/26 5:44 AM, Neeraj Kumar wrote: >> Using these attributes region label is added/deleted into LSA. These >> attributes are called from userspace (ndctl) after region creation. >> >> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com> > >Reviewed-by: Dave Jiang <dave.jiang@intel.com> Thanks Dave for RB tag. > >You'll need to update the KernelVersion to v7.0. Fixed it in V6. Regards, Neeraj
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