[PATCH V5 14/17] cxl/pmem_region: Introduce CONFIG_CXL_PMEM_REGION for core/pmem_region.c

Neeraj Kumar
2026-01-09T12:45:33Z

As pmem region label update/delete has hard dependency on libnvdimm.
It is therefore put core/pmem_region.c under CONFIG_CXL_PMEM_REGION
control. It handles the dependency by selecting CONFIG_LIBNVDIMM
if not enabled.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
---
drivers/cxl/Kconfig | 15 +++++++++++++++
drivers/cxl/core/Makefile | 3 ++-
drivers/cxl/core/core.h | 18 +++++++++++-------
drivers/cxl/cxl.h | 24 ++++++++++++++----------
tools/testing/cxl/Kbuild | 3 ++-
5 files changed, 44 insertions(+), 19 deletions(-)

diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index f1361ed6a0d4..307fed8f1f56 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -211,6 +211,21 @@ config CXL_REGION

If unsure say 'y'

+config CXL_PMEM_REGION
+ bool "CXL: Pmem Region Support"
+ default CXL_BUS
+ depends on CXL_REGION
+ depends on ARCH_HAS_PMEM_API
+ depends on PHYS_ADDR_T_64BIT
+ depends on BLK_DEV
+ select LIBNVDIMM
+ help
+ Enable the CXL core to enumerate and provision CXL pmem regions.
+ A CXL pmem region need to update region label into LSA. For LSA
+ update/delete libnvdimm is required.
+
+ If unsure say 'y'
+
config CXL_REGION_INVALIDATION_TEST
bool "CXL: Region Cache Management Bypass (TEST)"
depends on CXL_REGION
diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index fe0fcab6d730..399157beb917 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -16,7 +16,8 @@ cxl_core-y += pmu.o
cxl_core-y += cdat.o
cxl_core-y += ras.o
cxl_core-$(CONFIG_TRACING) += trace.o
-cxl_core-$(CONFIG_CXL_REGION) += region.o pmem_region.o
+cxl_core-$(CONFIG_CXL_REGION) += region.o
+cxl_core-$(CONFIG_CXL_PMEM_REGION) += pmem_region.o
cxl_core-$(CONFIG_CXL_MCE) += mce.o
cxl_core-$(CONFIG_CXL_FEATURES) += features.o
cxl_core-$(CONFIG_CXL_EDAC_MEM_FEATURES) += edac.o
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 4eed243c0d7d..5ae693269771 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -34,7 +34,6 @@ int cxl_decoder_detach(struct cxl_region *cxlr,
#define CXL_REGION_ATTR(x) (&dev_attr_##x.attr)
#define CXL_REGION_TYPE(x) (&cxl_region_type)
#define SET_CXL_REGION_ATTR(x) (&dev_attr_##x.attr),
-#define CXL_PMEM_REGION_TYPE(x) (&cxl_pmem_region_type)
#define CXL_DAX_REGION_TYPE(x) (&cxl_dax_region_type)
int cxl_region_init(void);
void cxl_region_exit(void);
@@ -47,7 +46,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
struct cxl_pmem_region_params *pmem_params,
struct cxl_endpoint_decoder *cxled);
struct cxl_region *to_cxl_region(struct device *dev);
-int devm_cxl_add_pmem_region(struct cxl_region *cxlr);

#else
static inline u64 cxl_dpa_to_hpa(struct cxl_region *cxlr,
@@ -89,17 +87,23 @@ static inline struct cxl_region *to_cxl_region(struct device *dev)
{
return NULL;
}
-static inline int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
-{
- return 0;
-}
#define CXL_REGION_ATTR(x) NULL
#define CXL_REGION_TYPE(x) NULL
#define SET_CXL_REGION_ATTR(x)
-#define CXL_PMEM_REGION_TYPE(x) NULL
#define CXL_DAX_REGION_TYPE(x) NULL
#endif

+#ifdef CONFIG_CXL_PMEM_REGION
+#define CXL_PMEM_REGION_TYPE(x) (&cxl_pmem_region_type)
+int devm_cxl_add_pmem_region(struct cxl_region *cxlr);
+#else
+#define CXL_PMEM_REGION_TYPE(x) NULL
+static inline int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
+{
+ return -EINVAL;
+}
+#endif
+
struct cxl_send_command;
struct cxl_mem_query_commands;
int cxl_query_cmd(struct cxl_mailbox *cxl_mbox,
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 684a0d1b441a..6ac3b40cb5ff 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -899,21 +899,11 @@ int devm_cxl_add_nvdimm(struct cxl_port *parent_port, struct cxl_memdev *cxlmd);
struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port);

#ifdef CONFIG_CXL_REGION
-bool is_cxl_pmem_region(struct device *dev);
-struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
int cxl_add_to_region(struct cxl_endpoint_decoder *cxled);
struct cxl_dax_region *to_cxl_dax_region(struct device *dev);
u64 cxl_port_get_spa_cache_alias(struct cxl_port *endpoint, u64 spa);
int cxl_region_discovery(struct cxl_memdev *cxlmd);
#else
-static inline bool is_cxl_pmem_region(struct device *dev)
-{
- return false;
-}
-static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
-{
- return NULL;
-}
static inline int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
{
return 0;
@@ -933,6 +923,20 @@ static inline int cxl_region_discovery(struct cxl_memdev *cxlmd)
}
#endif

+#ifdef CONFIG_CXL_PMEM_REGION
+bool is_cxl_pmem_region(struct device *dev);
+struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
+#else
+static inline bool is_cxl_pmem_region(struct device *dev)
+{
+ return false;
+}
+static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
void cxl_endpoint_parse_cdat(struct cxl_port *port);
void cxl_switch_parse_cdat(struct cxl_dport *dport);

diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index ad2496b38fdd..024922326a6b 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -59,7 +59,8 @@ cxl_core-y += $(CXL_CORE_SRC)/pmu.o
cxl_core-y += $(CXL_CORE_SRC)/cdat.o
cxl_core-y += $(CXL_CORE_SRC)/ras.o
cxl_core-$(CONFIG_TRACING) += $(CXL_CORE_SRC)/trace.o
-cxl_core-$(CONFIG_CXL_REGION) += $(CXL_CORE_SRC)/region.o $(CXL_CORE_SRC)/pmem_region.o
+cxl_core-$(CONFIG_CXL_REGION) += $(CXL_CORE_SRC)/region.o
+cxl_core-$(CONFIG_CXL_PMEM_REGION) += $(CXL_CORE_SRC)/pmem_region.o
cxl_core-$(CONFIG_CXL_MCE) += $(CXL_CORE_SRC)/mce.o
cxl_core-$(CONFIG_CXL_FEATURES) += $(CXL_CORE_SRC)/features.o
cxl_core-$(CONFIG_CXL_EDAC_MEM_FEATURES) += $(CXL_CORE_SRC)/edac.o
--
2.34.1