Date: Wed, 11 Jun 2008 11:47:30 +0200
From: Andreas Herrmann <andreas.herrmann3@amd.com>
To: "H. Peter Anvin" <hpa@zytor.com>
CC: Rene Herman <rene.herman@keyaccess.nl>,
       Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
       linux-kernel@vger.kernel.org,
       Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
       Suresh B Siddha <suresh.b.siddha@intel.com>
Subject: Re: [PATCH 2/5] x86: PAT: fix ambiguous paranoia check in
	pat_init()
Message-ID: <20080611094730.GB5889@alberich.amd.com>
References: <20080610140518.GF5024@alberich.amd.com> <484F065B.2050002@keyaccess.nl> <484F0F5D.8010507@zytor.com>
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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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