diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8a25704..7811294 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -78,6 +78,7 @@
 struct iommu_domain {
 	unsigned type;
 	const struct iommu_ops *ops;
+	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
 	iommu_fault_handler_t handler;
 	void *handler_token;
 	struct iommu_domain_geometry geometry;
@@ -155,7 +156,7 @@
  * @domain_set_windows: Set the number of windows for a domain
  * @domain_get_windows: Return the number of windows for a domain
  * @of_xlate: add OF master IDs to iommu grouping
- * @pgsize_bitmap: bitmap of supported page sizes
+ * @pgsize_bitmap: bitmap of all possible supported page sizes
  */
 struct iommu_ops {
 	bool (*capable)(enum iommu_cap);