+/**
+ * resource_alignment - calculate resource's alignment
+ * @res: resource pointer
+ *
+ * Returns alignment on success, 0 (invalid alignment) on failure.
+ */
+resource_size_t resource_alignment(struct resource *res)
+{
+ switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
+ case IORESOURCE_SIZEALIGN:
+ return resource_size(res);
+ case IORESOURCE_STARTALIGN:
+ return res->start;
+ default:
+ return 0;
+ }
+}
+