iommu: Convert iommu-caps from define to enum

Allow compile-time type-checking.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 20f9a52..98fc126 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -57,8 +57,11 @@
 	struct iommu_domain_geometry geometry;
 };
 
-#define IOMMU_CAP_CACHE_COHERENCY	0x1
-#define IOMMU_CAP_INTR_REMAP		0x2	/* isolates device intrs */
+enum iommu_cap {
+	IOMMU_CAP_CACHE_COHERENCY,	/* IOMMU can enforce cache coherent DMA
+					   transactions */
+	IOMMU_CAP_INTR_REMAP,		/* IOMMU supports interrupt isolation */
+};
 
 /*
  * Following constraints are specifc to FSL_PAMUV1:
@@ -155,7 +158,7 @@
 		       size_t size);
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova);
 extern int iommu_domain_has_cap(struct iommu_domain *domain,
-				unsigned long cap);
+				enum iommu_cap cap);
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 			iommu_fault_handler_t handler, void *token);
 
@@ -305,7 +308,7 @@
 }
 
 static inline int iommu_domain_has_cap(struct iommu_domain *domain,
-				       unsigned long cap)
+				       enum iommu_cap cap)
 {
 	return 0;
 }