Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 26 Oct 2015 19:56:06 -0700 | Subject | Re: [RFC PATCH] x86/cpu: Move sparsely used bit leafs into scattered features (was: Re: [PATCH 2/2] x86/cpufeature: Add CLZERO feature) |
| |
On Mon, Oct 26, 2015 at 2:01 PM, Borislav Petkov <bp@alien8.de> wrote: > On Mon, Oct 26, 2015 at 09:22:50PM +0100, Borislav Petkov wrote: >> And btw, those Intel QoS single bit defines and the XSAVE stuff there >> should move to that function too - that's a pure waste having them in >> the cap_flags array. I'll fix that. > > I.e., something like that (I'm jetlagged and I can't sleep, bah :-\). > > So this one builds but no further guarantees. It looks straightforward > though. > > Not-yet-signed-off-by: Borislav Petkov <bp@suse.de> > > --- > diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h > index 9727b3b48bd1..ea109b58a864 100644 > --- a/arch/x86/include/asm/cpufeature.h > +++ b/arch/x86/include/asm/cpufeature.h > @@ -12,7 +12,7 @@ > #include <asm/disabled-features.h> > #endif > > -#define NCAPINTS 13 /* N 32-bit words worth of info */ > +#define NCAPINTS 10 /* N 32-bit words worth of info */ > #define NBUGINTS 1 /* N 32-bit bug flags */ > > /* > @@ -198,6 +198,15 @@ > #define X86_FEATURE_HWP_EPP ( 7*32+13) /* Intel HWP_EPP */ > #define X86_FEATURE_HWP_PKG_REQ ( 7*32+14) /* Intel HWP_PKG_REQ */ > #define X86_FEATURE_INTEL_PT ( 7*32+15) /* Intel Processor Trace */ > +/* Extended state features, CPUID level 0x0000000d:1 (eax) */ > +#define X86_FEATURE_XSAVEOPT (7*32+ 16) /* XSAVEOPT */ > +#define X86_FEATURE_XSAVEC (7*32+ 17) /* XSAVEC */ > +#define X86_FEATURE_XGETBV1 (7*32+ 18) /* XGETBV with ECX = 1 */ > +#define X86_FEATURE_XSAVES (7*32+ 19) /* XSAVES/XRSTORS */
How few features in one leaf do we need before calling it scattered makes sense? These four might make sense to keep as is...
> +/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:0 (edx) */ > +#define X86_FEATURE_CQM_LLC (7*32+ 20) /* LLC QoS if 1 */ > +/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:1 (edx) */ > +#define X86_FEATURE_CQM_OCCUP_LLC (7*32+ 21) /* LLC occupancy monitoring if 1 */ >
...whereas this looks totally reasonable.
FWIW, we have a ton of thses things. Would it make sense to convert this to a text file giving features and their CPUID positions that generates the defines and the code to enumerate them?
--Andy
| |