diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8a7bfb1..0cf3a4e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -28,6 +28,8 @@
 	void *priv;
 };
 
+#define IOMMU_CAP_CACHE_COHERENCY	0x1
+
 struct iommu_ops {
 	int (*domain_init)(struct iommu_domain *domain);
 	void (*domain_destroy)(struct iommu_domain *domain);
@@ -39,6 +41,8 @@
 		      size_t size);
 	phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
 				    unsigned long iova);
+	int (*domain_has_cap)(struct iommu_domain *domain,
+			      unsigned long cap);
 };
 
 #ifdef CONFIG_IOMMU_API
@@ -57,6 +61,8 @@
 			      size_t size);
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
 				      unsigned long iova);
+extern int iommu_domain_has_cap(struct iommu_domain *domain,
+				unsigned long cap);
 
 #else /* CONFIG_IOMMU_API */
 
@@ -107,6 +113,12 @@
 	return 0;
 }
 
+static inline int domain_has_cap(struct iommu_domain *domain,
+				 unsigned long cap)
+{
+	return 0;
+}
+
 #endif /* CONFIG_IOMMU_API */
 
 #endif /* __LINUX_IOMMU_H */