Re: [RFC] Cachemap for 2.6.12rc4-mm1. Was Re: [PATCH] enhance x86 MTRR handling

Dave Jones
2005-05-13T23:43:34Z

On Fri, May 13, 2005 at 04:36:10PM -0700, H. Peter Anvin wrote:

> The Efficeon (TM8xxx) series does have PAT.

1:1 with the Intel implementation I assume based on your earlier comments?

> > > >+ * Note: On Athlon cpus PAT2/PAT3 & PAT6/PAT7 are both Uncacheable
> > since > >+ * there is no uncached type.
> > > If one sets the PAT to "uncached", does one get the same function as
> > > "uncachable"?
> >
> >AIUI, only as long as we don't have an MTRR covering the same range marked
> >WC.
> >It seems to be the only thing I could find documenting the differences
> >between 'uncached' and 'uncacheable' in this context.
> >Though I've only looked through the Intel & AMD K8 docs, I don't have
> >the K7 ones to hand.
> >
>
> I mean, on the Athlon series, is it really necessary to use a different
> value?

I'd have to dig out the docs and check.

Dave