Re: [djiang:cxl-security 1/19] include/linux/memregion.h:54:9: error: implicit declaration of function 'WARN_ON_ONCE'

[Davidlohr Bueso]

On Thu, 22 Sep 2022, kernel test robot wrote:
>    51
>    52	int cpu_cache_invalidate_memregion(int res_desc)
>    53	{
>  > 54		WARN_ON_ONCE("CPU cache invalidation required");

Looks like memregion.h needs to include kernel.h. I'll send a new version
along with EOPNOTSUPP return.