[PATCH V3 01/20] nvdimm/label: Introduce NDD_REGION_LABELING flag to set region label

Neeraj Kumar
2025-09-17T13:41:35Z

Prior to LSA 2.1 version, LSA contain only namespace labels. LSA 2.1
introduced in CXL 2.0 Spec, which contain region label along with
namespace label.

NDD_LABELING flag is used for namespace. Introduced NDD_REGION_LABELING
flag for region label. Based on these flags nvdimm driver performs
operation on namespace label or region label.

NDD_REGION_LABELING will be utilized by cxl driver to enable LSA 2.1
region label support

Accordingly updated label index version

Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
---
drivers/nvdimm/dimm.c | 1 +
drivers/nvdimm/dimm_devs.c | 7 +++++++
drivers/nvdimm/label.c | 21 +++++++++++++++++----
drivers/nvdimm/nd.h | 1 +
include/linux/libnvdimm.h | 3 +++
5 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/nvdimm/dimm.c b/drivers/nvdimm/dimm.c
index 91d9163ee303..bda22cb94e5b 100644
--- a/drivers/nvdimm/dimm.c
+++ b/drivers/nvdimm/dimm.c
@@ -62,6 +62,7 @@ static int nvdimm_probe(struct device *dev)
if (rc < 0)
dev_dbg(dev, "failed to unlock dimm: %d\n", rc);

+ ndd->cxl = nvdimm_check_region_label_format(ndd->dev);

/*
* EACCES failures reading the namespace label-area-properties
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 21498d461fde..918c3db93195 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -18,6 +18,13 @@

static DEFINE_IDA(dimm_ida);

+bool nvdimm_check_region_label_format(struct device *dev)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+
+ return test_bit(NDD_REGION_LABELING, &nvdimm->flags);
+}
+
/*
* Retrieve bus and dimm handle and return if this bus supports
* get_config_data commands
diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index 04f4a049599a..0a9b6c5cb2c3 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -688,11 +688,24 @@ static int nd_label_write_index(struct nvdimm_drvdata *ndd, int index, u32 seq,
- (unsigned long) to_namespace_index(ndd, 0);
nsindex->labeloff = __cpu_to_le64(offset);
nsindex->nslot = __cpu_to_le32(nslot);
- nsindex->major = __cpu_to_le16(1);
- if (sizeof_namespace_label(ndd) < 256)
+
+ /* Set LSA Label Index Version */
+ if (ndd->cxl) {
+ /* CXL r3.2: Table 9-9 Label Index Block Layout */
+ nsindex->major = __cpu_to_le16(2);
nsindex->minor = __cpu_to_le16(1);
- else
- nsindex->minor = __cpu_to_le16(2);
+ } else {
+ nsindex->major = __cpu_to_le16(1);
+ /*
+ * NVDIMM Namespace Specification
+ * Table 2: Namespace Label Index Block Fields
+ */
+ if (sizeof_namespace_label(ndd) < 256)
+ nsindex->minor = __cpu_to_le16(1);
+ else /* UEFI 2.7: Label Index Block Definitions */
+ nsindex->minor = __cpu_to_le16(2);
+ }
+
nsindex->checksum = __cpu_to_le64(0);
if (flags & ND_NSINDEX_INIT) {
unsigned long *free = (unsigned long *) nsindex->free;
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index cc5c8f3f81e8..158809c2be9e 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -522,6 +522,7 @@ void nvdimm_set_labeling(struct device *dev);
void nvdimm_set_locked(struct device *dev);
void nvdimm_clear_locked(struct device *dev);
int nvdimm_security_setup_events(struct device *dev);
+bool nvdimm_check_region_label_format(struct device *dev);
#if IS_ENABLED(CONFIG_NVDIMM_KEYS)
int nvdimm_security_unlock(struct device *dev);
#else
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 28f086c4a187..5696715c33bb 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -44,6 +44,9 @@ enum {
/* dimm provider wants synchronous registration by __nvdimm_create() */
NDD_REGISTER_SYNC = 8,

+ /* dimm supports region labels (LSA Format 2.1) */
+ NDD_REGION_LABELING = 9,
+
/* need to set a limit somewhere, but yes, this is likely overkill */
ND_IOCTL_MAX_BUFLEN = SZ_4M,
ND_CMD_MAX_ELEM = 5,
--
2.34.1