Some platforms may set up a preliminary ID map in flash and enter EFI with the MMU and caches enabled, as this removes a lot of the complexity around cache coherency. Let's take this into account, and avoid touching the MMU controls or perform cache invalidation when the MMU is enabled at entry. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>