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From: Mikael Pettersson <mikpe@user.it.uu.se>
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Date: Wed, 26 Feb 2003 15:26:27 +0100
To: davej@codemonkey.org.uk
Cc: linux-kernel@vger.kernel.org
Subject: Re: Enabling L2 cache for overdrive CPUs.
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davej@codemonkey.org.uk writes:
 > Some CPU overdrives (such as those made by powerleap) mean
 > that we get a CPU with L2 cache disabled by default, and
 > a BIOS that doesn't know how to turn it on.
 > The patch below is untested, and I'd like some feedback
 > from folks (preferably those with these wacky overdrives,
 > but also from regular intel CPUs too - disable L2 in your
 > bios and try booting with 'enable-l2' and see what happens).
...
 > +	cr0 = read_cr0();
 > +	cr0 |= 1<<30;
 > +	write_cr0 (cr0);
 > +
 > +	rdmsr (0x11e, lo, hi);
 > +	lo |= 0x40101;
 > +	wrmsr (0x11e, lo, hi);
 > +
 > +	cr0 &= ~(1<<30);
 > +	write_cr0 (cr0);
 > +
 > +	wbinvd();

Ugh. Is this for the PII overdrive for PPro socket or what?

Seems awfully dangerous to have a __setup() clobber MSRs without
checking the cpuid first. 
Shouldn't this be in the CPU detection/quirks code instead?
It already contains stuff similar to this.

/Mikael
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