For some cases (accessing registers, unmap legacy queue), it needs
access mes in atomic context. Use spinlock to protect agaist mes
ring buffer race condition.
Signed-off-by: Jack Xiao <Jack.Xiao@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>