ArmPkg/ArmLib MMU: add functions to set/clear RO and XN bits on regions

Use the refactored UpdateRegionMapping () to traverse the translation
tables, splitting block entries along the way if required, and apply
a mask + or on each to set or clear the PXN/UXN/XN or RO bits.

For now, the 32-bit ARM versions remain unimplemented.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18587 6f19259b-4bc3-4df7-8a09-765794883524

ArmPkg/Include/Library/ArmLib.h

@@ -661,4 +661,28 @@ ArmUnsetCpuActlrBit (
   IN  UINTN    Bits
   );
 
+RETURN_STATUS
+ArmSetMemoryRegionNoExec (
+  IN  EFI_PHYSICAL_ADDRESS      BaseAddress,
+  IN  UINT64                    Length
+  );
+
+RETURN_STATUS
+ArmClearMemoryRegionNoExec (
+  IN  EFI_PHYSICAL_ADDRESS      BaseAddress,
+  IN  UINT64                    Length
+  );
+
+RETURN_STATUS
+ArmSetMemoryRegionReadOnly (
+  IN  EFI_PHYSICAL_ADDRESS      BaseAddress,
+  IN  UINT64                    Length
+  );
+
+RETURN_STATUS
+ArmClearMemoryRegionReadOnly (
+  IN  EFI_PHYSICAL_ADDRESS      BaseAddress,
+  IN  UINT64                    Length
+  );
+
 #endif // __ARM_LIB__