diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
index 2059a67bbf..a328146b69 100644
--- a/ArmPkg/Include/Library/ArmLib.h
+++ b/ArmPkg/Include/Library/ArmLib.h
@@ -114,6 +114,12 @@ ArmInstructionCacheLineLength (
   VOID
   );
 
+UINTN
+EFIAPI
+ArmCacheWritebackGranule (
+  VOID
+  );
+
 UINTN
 EFIAPI
 ArmIsArchTimerImplemented (
diff --git a/ArmPkg/Library/ArmLib/Common/ArmLib.c b/ArmPkg/Library/ArmLib/Common/ArmLib.c
index ad0a265e9f..7e227936fa 100644
--- a/ArmPkg/Library/ArmLib/Common/ArmLib.c
+++ b/ArmPkg/Library/ArmLib/Common/ArmLib.c
@@ -88,3 +88,20 @@ ArmInstructionCacheLineLength (
 {
   return 4 << (ArmCacheInfo () & 0xf); // CTR_EL0.IminLine
 }
+
+UINTN
+EFIAPI
+ArmCacheWritebackGranule (
+  VOID
+  )
+{
+  UINTN   CWG;
+
+  CWG = (ArmCacheInfo () >> 24) & 0xf; // CTR_EL0.CWG
+
+  if (CWG == 0) {
+    return SIZE_2KB;
+  }
+
+  return 4 << CWG;
+}