Re: [PATCH v3 04/18] x86/intel_rdt: Feature discovery

From: Fenghua Yu
Date: Sat Oct 08 2016 - 13:51:52 EST


On Sat, Oct 08, 2016 at 12:11:22PM -0500, Nilay Vaish wrote:
> On 7 October 2016 at 21:45, Fenghua Yu <fenghua.yu@xxxxxxxxx> wrote:
> > From: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> >
> > Check CPUID leaves for all the Resource Director Technology (RDT)
> > Cache Allocation Technology (CAT) bits.
> >
> > Prescence of allocation features:
>
> Presence
>
> > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> > index 92a8308..64dd8274 100644
> > --- a/arch/x86/include/asm/cpufeatures.h
> > +++ b/arch/x86/include/asm/cpufeatures.h
> > @@ -196,6 +196,10 @@
> >
> > #define X86_FEATURE_INTEL_PT ( 7*32+15) /* Intel Processor Trace */
> >
> > +#define X86_FEATURE_CAT_L3 ( 7*32+16) /* Cache Allocation Technology L3 */
> > +#define X86_FEATURE_CAT_L2 ( 7*32+17) /* Cache Allocation Technology L2 */
> > +#define X86_FEATURE_CDP_L3 ( 7*32+18) /* Code and Data Prioritization L3 */
> > +
> > /* Virtualization flags: Linux defined, word 8 */
> > #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */
> > #define X86_FEATURE_VNMI ( 8*32+ 1) /* Intel Virtual NMI */
> > @@ -220,6 +224,7 @@
> > #define X86_FEATURE_RTM ( 9*32+11) /* Restricted Transactional Memory */
> > #define X86_FEATURE_CQM ( 9*32+12) /* Cache QoS Monitoring */
> > #define X86_FEATURE_MPX ( 9*32+14) /* Memory Protection Extension */
> > +#define X86_FEATURE_RDT_A ( 9*32+15) /* Resource Director Technology Allocation */
> > #define X86_FEATURE_AVX512F ( 9*32+16) /* AVX-512 Foundation */
> > #define X86_FEATURE_AVX512DQ ( 9*32+17) /* AVX-512 DQ (Double/Quad granular) Instructions */
> > #define X86_FEATURE_RDSEED ( 9*32+18) /* The RDSEED instruction */
>
> I think these #defines are specific to Intel. I would prefer if we
> have _INTEL_ somewhere in them.

Is adding "Intel" in comment good?

+#define X86_FEATURE_CAT_L3 ( 7*32+16) /* Intel Cache Allocation Technology L3 */
+#define X86_FEATURE_CAT_L2 ( 7*32+17) /* Intel Cache Allocation Technology L2 */
+#define X86_FEATURE_CDP_L3 ( 7*32+18) /* Intel Code and Data Prioritization L3 */

Thanks.

-Fenghua