Re: [PATCH V2 10/20] nvdimm/region_label: Preserve cxl region information from region label

[Neeraj Kumar]

On 13/08/25 04:11PM, Jonathan Cameron wrote:

On Wed, 30 Jul 2025 17:41:59 +0530
Neeraj Kumar <s.nee...@samsung.com> wrote:

Preserve region information from region label during nvdimm_probe. This
preserved region information is used for creating cxl region to achieve
region persistency across reboot.

Signed-off-by: Neeraj Kumar <s.nee...@samsung.com>

See below.

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index 064a945dcdd1..bcac05371f87 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -473,6 +473,47 @@ int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
        return 0;
 }

+int nvdimm_cxl_region_preserve(struct nvdimm_drvdata *ndd)
+{
+       struct nvdimm *nvdimm = to_nvdimm(ndd->dev);
+       struct cxl_pmem_region_params *params = &nvdimm->cxl_region_params;
+       struct nd_namespace_index *nsindex;
+       unsigned long *free;
+       u32 nslot, slot;
+
+       if (!preamble_current(ndd, &nsindex, &free, &nslot))
+               return 0; /* no label, nothing to preserve */
+
+       for_each_clear_bit_le(slot, free, nslot) {
+               struct nd_lsa_label *nd_label;
+               struct cxl_region_label *rg_label;
+               uuid_t rg_type, region_type;
+
+               nd_label = to_label(ndd, slot);
+               rg_label = &nd_label->rg_label;
+               uuid_parse(CXL_REGION_UUID, &region_type);
+               import_uuid(&rg_type, nd_label->rg_label.type);
+
+               /* REVISIT: Currently preserving only one region */

In practice, is this a significant issue or not?  I.e. should we not
merge this series until this has been revisited?

As currently we have support of Interleave way == 1, thats why this
REVISIST. I will remove this, as its not significant issue for merging this 
series


Regards,
Neeraj