linux-kernel - Re: [PATCH v1 4/4] Add R3MWAIT to CPU features

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Date:   Wed, 12 Oct 2016 12:32:04 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Grzegorz Andrejczuk <grzegorz.andrejczuk@...el.com>
Cc:     tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        x86@...nel.org, dave.hansen@...ux.intel.com,
        linux-kernel@...r.kernel.org, lukasz.daniluk@...el.com,
        james.h.cownie@...el.com
Subject: Re: [PATCH v1 4/4] Add R3MWAIT to CPU features

On Wed, Oct 12, 2016 at 12:13:10PM +0200, Grzegorz Andrejczuk wrote:
> Add cpu feature for ring 3 monitor/mwait.
> 
> Change-Id: Iba4d20639efd8d3637d37db9294cbc43a98f009a

Please no internal IDs in upstream submission.

> Signed-off-by: Grzegorz Andrejczuk <grzegorz.andrejczuk@...el.com>

...

> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> index 92a8308..242cd16 100644
> --- a/arch/x86/include/asm/cpufeatures.h
> +++ b/arch/x86/include/asm/cpufeatures.h
> @@ -12,7 +12,7 @@
>  /*
>   * Defines x86 CPU feature bits
>   */
> -#define NCAPINTS	18	/* N 32-bit words worth of info */
> +#define NCAPINTS	19	/* N 32-bit words worth of info */
>  #define NBUGINTS	1	/* N 32-bit bug flags */
>  
>  /*
> @@ -286,6 +286,10 @@
>  #define X86_FEATURE_SUCCOR	(17*32+1) /* Uncorrectable error containment and recovery */
>  #define X86_FEATURE_SMCA	(17*32+3) /* Scalable MCA */
>  
> +
> +/* non architectural Intel-defined CPU features not present in CPUID, word 18 */
> +#define X86_FEATURE_PHIR3MWAIT	(18*32+ 0)

Please use init_scattered_cpuid_features() for the whole
thing. There are some free bits in word 3 for example, see
arch/x86/include/asm/cpufeatures.h.

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--