[ Upstream commit ead60e9c4e29c8574cae1be4fe3af1d9a978fb0f ] Protect the MMIO access with safe mode. Acked-by: Vitaly Prosyak <vitaly.prosyak@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>