diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.h b/UefiCpuPkg/CpuDxe/CpuDxe.h
index a25b35c6eb..9c0d22359d 100644
--- a/UefiCpuPkg/CpuDxe/CpuDxe.h
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.h
@@ -265,6 +265,9 @@ SetDataSelectors (
   UINT16 Selector
   );
 
+/**
+  Update GCD memory space attributes according to current page table setup.
+**/
 VOID
 RefreshGcdMemoryAttributesFromPaging (
   VOID