x86/amd-iommu: Add flag to indicate IOTLB support

This patch adds a flag to the AMD IOMMU driver to indicate
that all IOMMUs present in the system support device IOTLBs.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index f5d184e7..cb811c9 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -250,6 +250,8 @@
 
 /* global flag if IOMMUs cache non-present entries */
 extern bool amd_iommu_np_cache;
+/* Only true if all IOMMUs support device IOTLBs */
+extern bool amd_iommu_iotlb_sup;
 
 /*
  * Make iterating over all IOMMUs easier