--- 65877bc5edaae9e67dd391b665de91670556fd20
+++ 55748d6a62658b26926184d4ec55d3b9ec611dbc
@@ -433,18 +433,23 @@ xpc_discovery(void)
 	 * nodes that can comprise an access protection grouping. The access
 	 * protection is in regards to memory, IOI and IPI.
 	 */
-	max_regions = 64;
 	region_size = xp_region_size;
 
-	switch (region_size) {
-	case 128:
-		max_regions *= 2;
-	case 64:
-		max_regions *= 2;
-	case 32:
-		max_regions *= 2;
-		region_size = 16;
-		DBUG_ON(!is_shub2());
+	if (is_uv())
+		max_regions = 256;
+	else {
+		max_regions = 64;
+
+		switch (region_size) {
+		case 128:
+			max_regions *= 2;
+		case 64:
+			max_regions *= 2;
+		case 32:
+			max_regions *= 2;
+			region_size = 16;
+			DBUG_ON(!is_shub2());
+		}
 	}
 
 	for (region = 0; region < max_regions; region++) {