RE: [PATCH v6: 4/4] x86/cpufeature: Add R3MWAIT to CPU features

[Andrejczuk, Grzegorz]

> On Thu, Oct 27, 2016 at 04:02:03PM +0200, Grzegorz Andrejczuk wrote:
> > Add cpu feature for ring 3 monitor/mwait.
> > Set HWCAP2 1st bit during init.
> > 
> > Signed-off-by: Grzegorz Andrejczuk <grzegorz.andrejczuk@xxxxxxxxx>
> > ---
> >  arch/x86/include/asm/cpufeatures.h | 2 ++
> >  arch/x86/kernel/cpu/intel.c        | 4 ++++
> >  2 files changed, 6 insertions(+)
> > 
> > diff --git a/arch/x86/include/asm/cpufeatures.h 
> > b/arch/x86/include/asm/cpufeatures.h
> > index 92a8308..d430200 100644
> > --- a/arch/x86/include/asm/cpufeatures.h
> > +++ b/arch/x86/include/asm/cpufeatures.h
> > @@ -71,6 +71,8 @@
> >  #define X86_FEATURE_RECOVERY	( 2*32+ 0) /* CPU in recovery mode */
> >  #define X86_FEATURE_LONGRUN	( 2*32+ 1) /* Longrun power control */
> >  #define X86_FEATURE_LRTI	( 2*32+ 3) /* LongRun table interface */
> > +/* Xeon Phi x200 ring 3 MONITOR/MWAIT enabled */
> > +#define X86_FEATURE_PHIR3MWAIT	( 2*32+ 4)
>
> This leaf is for Transmeta CPUs:
>
> /* Transmeta-defined CPU features, CPUID level 0x80860001, word 2 */
>
> is KNL close to some Transmeta design, per chance or so?
>
> I mean, for this to work, it would have to implement CPUID leaf 0x80860001...
>

I was reusing Word 3 as you suggested in patch rev. 1. There was idea to use init_scattered_cpuid_features.
What is good place for this feature?