diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
index cc7125e4fc..190f4b0dc7 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
@@ -1081,7 +1081,7 @@ PciIoUnmap (
 
 /**
   Allocates pages that are suitable for an EfiPciIoOperationBusMasterCommonBuffer
-  mapping.
+  or EfiPciOperationBusMasterCommonBuffer64 mapping.
 
   @param  This                  A pointer to the EFI_PCI_IO_PROTOCOL instance.
   @param  Type                  This parameter is not used and must be ignored.
@@ -1094,7 +1094,7 @@ PciIoUnmap (
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 
diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.h b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.h
index da3de3938e..b7e38ded3f 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.h
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.h
@@ -411,7 +411,7 @@ PciIoUnmap (
 
 /**
   Allocates pages that are suitable for an EfiPciIoOperationBusMasterCommonBuffer
-  mapping.
+  or EfiPciOperationBusMasterCommonBuffer64 mapping.
 
   @param  This                  A pointer to the EFI_PCI_IO_PROTOCOL instance.
   @param  Type                  This parameter is not used and must be ignored.
@@ -424,7 +424,7 @@ PciIoUnmap (
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 
diff --git a/MdeModulePkg/Include/Ppi/IoMmu.h b/MdeModulePkg/Include/Ppi/IoMmu.h
index 5303d68b07..ed8cd540a2 100644
--- a/MdeModulePkg/Include/Ppi/IoMmu.h
+++ b/MdeModulePkg/Include/Ppi/IoMmu.h
@@ -141,7 +141,7 @@ EFI_STATUS
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 
diff --git a/MdeModulePkg/Include/Protocol/IoMmu.h b/MdeModulePkg/Include/Protocol/IoMmu.h
index 9d25c17a5e..1e06efeb6a 100644
--- a/MdeModulePkg/Include/Protocol/IoMmu.h
+++ b/MdeModulePkg/Include/Protocol/IoMmu.h
@@ -203,7 +203,7 @@ EFI_STATUS
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.