Re: [PATCH V4 09/17] nvdimm/label: Export routine to fetch region information

[Neeraj Kumar]

On 17/12/25 03:12PM, Jonathan Cameron wrote:
> On Wed, 19 Nov 2025 13:22:47 +0530
> Neeraj Kumar <s.neeraj@xxxxxxxxxxx> wrote:
>
> > CXL region information preserved from the LSA needs to be exported for
> > use by the CXL driver for CXL region re-creation.
> To me it feels like the !nvdimm checks may be excessive in an interface
> that makes no sense if NULL is passed in.
> Perhaps drop those?
>
> > Signed-off-by: Neeraj Kumar <s.neeraj@xxxxxxxxxxx>
> > ---
> >  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 3363a97cc5b5..1474b4e45fcc 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 false;
>
> Seems a bit odd that this would ever get called on !nvdimm.
> Is that protection worth adding?
>
> > +
> > +	return nvdimm->is_region_label;
> > +}
> > +EXPORT_SYMBOL_GPL(nvdimm_has_cxl_region);
> > +
> > +void *nvdimm_get_cxl_region_param(struct nvdimm *nvdimm)
> > +{
> > +	if (!nvdimm)
>
> This feels a little more plausible as defense but is this
> needed?

Yes we can avoid this check, I have fixed it in V5.


Regards,
Neeraj