libnvdimm: Move nd_region_attribute_group to device_type

A 'struct device_type' instance can carry default attributes for the
device. Use this facility to remove the export of
nd_region_attribute_group and put the responsibility on the core rather
than leaf implementations to define this attribute.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/157309902169.1582359.16828508538444551337.stgit@dwillia2-desk3.amr.corp.intel.com

arch/powerpc/platforms/pseries/papr_scm.c

@@ -285,7 +285,6 @@ int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 }
 
 static const struct attribute_group *region_attr_groups[] = {
-	&nd_region_attribute_group,
 	&nd_mapping_attribute_group,
 	NULL,
 };

drivers/acpi/nfit/core.c

@@ -2196,7 +2196,6 @@ static const struct attribute_group acpi_nfit_region_attribute_group = {
 };
 
 static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
-	&nd_region_attribute_group,
 	&nd_mapping_attribute_group,
 	&acpi_nfit_region_attribute_group,
 	NULL,

drivers/nvdimm/e820.c

@@ -13,11 +13,6 @@ static const struct attribute_group *e820_pmem_attribute_groups[] = {
 	NULL,
 };
 
-static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
-	&nd_region_attribute_group,
-	NULL,
-};
-
 static int e820_pmem_remove(struct platform_device *pdev)
 {
 	struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
@@ -45,7 +40,6 @@ static int e820_register_one(struct resource *res, void *data)
 
 	memset(&ndr_desc, 0, sizeof(ndr_desc));
 	ndr_desc.res = res;
-	ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
 	ndr_desc.numa_node = e820_range_to_nid(res->start);
 	ndr_desc.target_node = ndr_desc.numa_node;
 	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);

drivers/nvdimm/of_pmem.c

@@ -9,11 +9,6 @@
 #include <linux/ioport.h>
 #include <linux/slab.h>
 
-static const struct attribute_group *region_attr_groups[] = {
-	&nd_region_attribute_group,
-	NULL,
-};
-
 static const struct attribute_group *bus_attr_groups[] = {
 	&nvdimm_bus_attribute_group,
 	NULL,
@@ -65,7 +60,6 @@ static int of_pmem_region_probe(struct platform_device *pdev)
 		 * structures so passing a stack pointer is fine.
 		 */
 		memset(&ndr_desc, 0, sizeof(ndr_desc));
-		ndr_desc.attr_groups = region_attr_groups;
 		ndr_desc.numa_node = dev_to_node(&pdev->dev);
 		ndr_desc.target_node = ndr_desc.numa_node;
 		ndr_desc.res = &pdev->resource[i];

drivers/nvdimm/region_devs.c

@@ -757,14 +757,14 @@ struct attribute_group nd_mapping_attribute_group = {
 };
 EXPORT_SYMBOL_GPL(nd_mapping_attribute_group);
 
-struct attribute_group nd_region_attribute_group = {
+static const struct attribute_group nd_region_attribute_group = {
 	.attrs = nd_region_attributes,
 	.is_visible = region_visible,
 };
-EXPORT_SYMBOL_GPL(nd_region_attribute_group);
 
 static const struct attribute_group *nd_region_attribute_groups[] = {
 	&nd_device_attribute_group,
+	&nd_region_attribute_group,
 	&nd_numa_attribute_group,
 	NULL,
 };

include/linux/libnvdimm.h

@@ -67,7 +67,6 @@ enum {
 
 extern struct attribute_group nvdimm_bus_attribute_group;
 extern struct attribute_group nvdimm_attribute_group;
-extern struct attribute_group nd_region_attribute_group;
 extern struct attribute_group nd_mapping_attribute_group;
 
 struct nvdimm;