diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 2cd07cc29687c49bd1cf8a0883cf5c72bbb4e762..22d2115458c67fe1e6e499996a9218af36fb772a 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -118,6 +118,10 @@ extern int allocate_resource(struct resource *root, struct resource *new,
 int adjust_resource(struct resource *res, resource_size_t start,
 		    resource_size_t size);
 resource_size_t resource_alignment(struct resource *res);
+static inline resource_size_t resource_size(struct resource *res)
+{
+	return res->end - res->start + 1;
+}
 
 /* Convenience shorthand with allocation */
 #define request_region(start,n,name)	__request_region(&ioport_resource, (start), (n), (name))
diff --git a/kernel/resource.c b/kernel/resource.c
index 74af2d7cb5a135ffa1da4c52ce9af026c527044d..f5b518eabefec5cfe880c230fe07ce7b8615f732 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -490,7 +490,7 @@ resource_size_t resource_alignment(struct resource *res)
 {
 	switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 	case IORESOURCE_SIZEALIGN:
-		return res->end - res->start + 1;
+		return resource_size(res);
 	case IORESOURCE_STARTALIGN:
 		return res->start;
 	default: