Re: [PATCH 2/5] x86: PAT: fix ambiguous paranoia check inpat_init()

From: Andreas Herrmann
Date: Wed Jun 11 2008 - 05:48:19 EST


On Tue, Jun 10, 2008 at 04:33:49PM -0700, H. Peter Anvin wrote:
> Rene Herman wrote:
>> The current setup is okay really. The only thing it still wants is a
>> commandline whitelist switch but that needs a somewhat different setup as
>> validate_pat_support() is too early for __setup() or early_param().
>
> Actually, I think it's time to nuke the whitelist. I don't think it has
> any CPUs on it that have the PAT flag enabled, still.

For Intel all family 0xf CPUs, and family 6 CPUs starting with model
15 are whitelisted.

There seem to be other Intel CPUs that advertise PAT support.
See cpuinfo output at http://gentoo-wiki.com/Safe_Cflags
E.g. Pentium M (model 13), Celeron (model 6), Pentium III (model 8).
(Not sure how correct this information is, though)

Turn the white- into a blacklist for those remaining CPUs until they
are verified?


Andreas


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