[PATCH V2] powerpc: Don't do runtime futex_cmpxchg test

[Michael Ellerman]

"Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com> writes:

> futex_detect_cmpxchg() does a cmpxchg_futex_value_locked on a NULL user addr to
> runtime detect whether architecture implements atomic cmpxchg for futex. POWER
> do implement the feature and hence we can enable the config instead of depending
> on runtime detection.
>
> We could possible enable this on everything. For now limitted to book3s_64
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> ---
>  arch/powerpc/platforms/Kconfig.cputype | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
> index a429d859f15d..31bc2bd5dfd1 100644
> --- a/arch/powerpc/platforms/Kconfig.cputype
> +++ b/arch/powerpc/platforms/Kconfig.cputype
> @@ -75,6 +75,7 @@ config PPC_BOOK3S_64
>  	select ARCH_SUPPORTS_NUMA_BALANCING
>  	select IRQ_WORK
>  	select HAVE_KERNEL_XZ
> +	select HAVE_FUTEX_CMPXCHG if FUTEX
  
I'd rather it was under config PPC with an if BOOK3S_64 check. Just so
that all those top-level style configs are in once place.

eg.

config PPC
	...
	select HAVE_FUTEX_CMPXCHG if FUTEX && PPC_BOOK3S_64

cheers