linux-kernel - Re: [PATCH V2 01/10] x86/CPU: Expose if cache is inclusive of lower level caches

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Message-ID: <20190806204054.GD4698@zn.tnic>
Date:   Tue, 6 Aug 2019 22:40:54 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Reinette Chatre <reinette.chatre@...el.com>
Cc:     tglx@...utronix.de, fenghua.yu@...el.com, tony.luck@...el.com,
        kuo-lang.tseng@...el.com, mingo@...hat.com, hpa@...or.com,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2 01/10] x86/CPU: Expose if cache is inclusive of lower
 level caches

On Tue, Aug 06, 2019 at 01:22:22PM -0700, Reinette Chatre wrote:
> ... because some platforms differ in which SKUs support cache
> pseudo-locking. On these platforms only the SKUs with inclusive cache
> support cache pseudo-locking, thus the additional check.

Ok, so it sounds to me like that check in get_prefetch_disable_bits()
should be extended (and maybe renamed) to check for cache inclusivity
too, in order to know which platforms support cache pseudo-locking.
I'd leave it to tglx to say how we should mirror cache inclusivity in
cpuinfo_x86: whether a synthetic X86_FEATURE bit or cache the respective
CPUID words which state whether L2/L3 is inclusive...

Thx.

-- 
Regards/Gruss,
    Boris.

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