Re: [PATCH V3 12/20] nvdimm/region_label: Export routine to fetch region information

Dave Jiang
2025-09-23T20:23:20Z

On 9/17/25 6:41 AM, Neeraj Kumar wrote:
> CXL region information preserved from the LSA needs to be exported for
> use by the CXL driver for CXL region re-creation.
>
> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
> ---
> drivers/nvdimm/dimm_devs.c | 18 ++++++++++++++++++
> include/linux/libnvdimm.h | 2 ++
> 2 files changed, 20 insertions(+)
>
> diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
> index 918c3db93195..619c8ce56dce 100644
> --- a/drivers/nvdimm/dimm_devs.c
> +++ b/drivers/nvdimm/dimm_devs.c
> @@ -280,6 +280,24 @@ void *nvdimm_provider_data(struct nvdimm *nvdimm)
> }
> EXPORT_SYMBOL_GPL(nvdimm_provider_data);
>
> +bool nvdimm_has_cxl_region(struct nvdimm *nvdimm)
> +{
> + if (nvdimm)
> + return nvdimm->is_region_label;
> +
> + return false;

Just a nit. Would prefer return error early and return the success case last.

> +}
> +EXPORT_SYMBOL_GPL(nvdimm_has_cxl_region);
> +
> +void *nvdimm_get_cxl_region_param(struct nvdimm *nvdimm)
> +{
> + if (nvdimm)
> + return &nvdimm->cxl_region_params;
> +
> + return NULL;

same comment

> +}
> +EXPORT_SYMBOL_GPL(nvdimm_get_cxl_region_param);
> +
> static ssize_t commands_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
> index 07ea2e3f821a..3ffd50ab6ac4 100644
> --- a/include/linux/libnvdimm.h
> +++ b/include/linux/libnvdimm.h
> @@ -330,6 +330,8 @@ int nvdimm_in_overwrite(struct nvdimm *nvdimm);
> bool is_nvdimm_sync(struct nd_region *nd_region);
> int nd_region_label_update(struct nd_region *nd_region);
> int nd_region_label_delete(struct nd_region *nd_region);
> +bool nvdimm_has_cxl_region(struct nvdimm *nvdimm);
> +void *nvdimm_get_cxl_region_param(struct nvdimm *nvdimm);
>
> static inline int nvdimm_ctl(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
> unsigned int buf_len, int *cmd_rc)