libnvdimm/labels: Add type-guid helpers

In preparation for CXL label support, which does not have the type-guid
concept, wrap the existing users with nsl_set_type_guid, and
nsl_validate_type_guid. Recall that the type-guid is a value in the ACPI
NFIT table to indicate how the memory range is used / should be
presented to upper layers.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162982116208.1124374.13938280892226800953.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/label.c

@@ -772,6 +772,26 @@ static void reap_victim(struct nd_mapping *nd_mapping,
 	victim->label = NULL;
 }
 
+static void nsl_set_type_guid(struct nvdimm_drvdata *ndd,
+			      struct nd_namespace_label *nd_label, guid_t *guid)
+{
+	if (namespace_label_has(ndd, type_guid))
+		guid_copy(&nd_label->type_guid, guid);
+}
+
+bool nsl_validate_type_guid(struct nvdimm_drvdata *ndd,
+			    struct nd_namespace_label *nd_label, guid_t *guid)
+{
+	if (!namespace_label_has(ndd, type_guid))
+		return true;
+	if (!guid_equal(&nd_label->type_guid, guid)) {
+		dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n", guid,
+			&nd_label->type_guid);
+		return false;
+	}
+	return true;
+}
+
 static int __pmem_label_update(struct nd_region *nd_region,
 		struct nd_mapping *nd_mapping, struct nd_namespace_pmem *nspm,
 		int pos, unsigned long flags)
@@ -822,8 +842,7 @@ static int __pmem_label_update(struct nd_region *nd_region,
 	nsl_set_lbasize(ndd, nd_label, nspm->lbasize);
 	nsl_set_dpa(ndd, nd_label, res->start);
 	nsl_set_slot(ndd, nd_label, slot);
-	if (namespace_label_has(ndd, type_guid))
-		guid_copy(&nd_label->type_guid, &nd_set->type_guid);
+	nsl_set_type_guid(ndd, nd_label, &nd_set->type_guid);
 	if (namespace_label_has(ndd, abstraction_guid))
 		guid_copy(&nd_label->abstraction_guid,
 				to_abstraction_guid(ndns->claim_class,
@@ -1091,8 +1110,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 		nsl_set_rawsize(ndd, nd_label, resource_size(res));
 		nsl_set_lbasize(ndd, nd_label, nsblk->lbasize);
 		nsl_set_slot(ndd, nd_label, slot);
-		if (namespace_label_has(ndd, type_guid))
-			guid_copy(&nd_label->type_guid, &nd_set->type_guid);
+		nsl_set_type_guid(ndd, nd_label, &nd_set->type_guid);
 		if (namespace_label_has(ndd, abstraction_guid))
 			guid_copy(&nd_label->abstraction_guid,
 					to_abstraction_guid(ndns->claim_class,

drivers/nvdimm/namespace_devs.c

@@ -1859,14 +1859,9 @@ static bool has_uuid_at_pos(struct nd_region *nd_region, u8 *uuid,
 			if (memcmp(nd_label->uuid, uuid, NSLABEL_UUID_LEN) != 0)
 				continue;
 
-			if (namespace_label_has(ndd, type_guid)
-					&& !guid_equal(&nd_set->type_guid,
-						&nd_label->type_guid)) {
-				dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
-						&nd_set->type_guid,
-						&nd_label->type_guid);
+			if (!nsl_validate_type_guid(ndd, nd_label,
+						    &nd_set->type_guid))
 				continue;
-			}
 
 			if (found_uuid) {
 				dev_dbg(ndd->dev, "duplicate entry for uuid\n");
@@ -2265,14 +2260,8 @@ static struct device *create_namespace_blk(struct nd_region *nd_region,
 	struct device *dev = NULL;
 	struct resource *res;
 
-	if (namespace_label_has(ndd, type_guid)) {
-		if (!guid_equal(&nd_set->type_guid, &nd_label->type_guid)) {
-			dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
-					&nd_set->type_guid,
-					&nd_label->type_guid);
-			return ERR_PTR(-EAGAIN);
-		}
-	}
+	if (!nsl_validate_type_guid(ndd, nd_label, &nd_set->type_guid))
+		return ERR_PTR(-EAGAIN);
 	if (!nsl_validate_blk_isetcookie(ndd, nd_label, nd_set->cookie2))
 		return ERR_PTR(-EAGAIN);
 

drivers/nvdimm/nd.h

@@ -180,6 +180,8 @@ static inline void nsl_set_lbasize(struct nvdimm_drvdata *ndd,
 bool nsl_validate_blk_isetcookie(struct nvdimm_drvdata *ndd,
 				 struct nd_namespace_label *nd_label,
 				 u64 isetcookie);
+bool nsl_validate_type_guid(struct nvdimm_drvdata *ndd,
+			    struct nd_namespace_label *nd_label, guid_t *guid);
 
 struct nd_region_data {
 	int ns_count;