+/**\r
+ Flush VTd engine write buffer.\r
+\r
+ @param[in] VtdIndex The index used to identify a VTd engine.\r
+**/\r
+VOID\r
+FlushWriteBuffer (\r
+ IN UINTN VtdIndex\r
+ );\r
+\r
+/**\r
+ Invalidate VTd context cache.\r
+\r
+ @param[in] VtdIndex The index used to identify a VTd engine.\r
+**/\r
+EFI_STATUS\r
+InvalidateContextCache (\r
+ IN UINTN VtdIndex\r
+ );\r
+\r
+/**\r
+ Invalidate VTd IOTLB.\r
+\r
+ @param[in] VtdIndex The index used to identify a VTd engine.\r
+**/\r
+EFI_STATUS\r
+InvalidateIOTLB (\r
+ IN UINTN VtdIndex\r
+ );\r
+\r