diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 1a60dd6..eccb0c0 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -53,6 +53,10 @@
 #define for_each_drhd_unit(drhd) \
 	list_for_each_entry(drhd, &dmar_drhd_units, list)
 
+#define for_each_active_drhd_unit(drhd)					\
+	list_for_each_entry(drhd, &dmar_drhd_units, list)		\
+		if (drhd->ignored) {} else
+
 #define for_each_active_iommu(i, drhd)					\
 	list_for_each_entry(drhd, &dmar_drhd_units, list)		\
 		if (i=drhd->iommu, drhd->ignored) {} else