Re: [patch 3/3] add Via Nehemiah ("xstore") rng support

H. Peter Anvin (hpa@zytor.com)
12 Mar 2003 08:21:26 -0800

Followup to: <Pine.LNX.4.44.0303120714030.13807-100000@home.transmeta.com>
By author: Linus Torvalds <torvalds@transmeta.com>
In newsgroup: linux.dev.kernel
>
>
> On Wed, 12 Mar 2003, Dave Jones wrote:
> >
> > > +#define cpu_has_xstore boot_cpu_has(X86_FEATURE_XSTORE)
> >
> > Do we want to do this check only on VIA CPUs I wonder.
> > As a vendor specific extension, I'd be inclined to do that.
>
> No, the whole point of all the crud in arch/i386/kernel/cpu is to make
> those tests _once_ at bootup, and then the internal kernel "extended CPU
> feature set" has a unique feature-set that is independent of manufacturers
> and totally disjunct, so that we never need to care about manufacturers
> ever again.
>

Right. I have also pointed out to Jeff already that the test is done
wrong... it's pretty clear from the code that VIA has set up a feature
flag space of their own like Intel, AMD and Transmeta already have
(which is a good thing), so we should add that as an additional word
in the feature test vector instead of special-casing such a bit.

In fact, we need to add two words since Intel ran out of theirs and
started using additional flags in %ecx just recently.

-hpa

-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
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