lkml.org 
[lkml]   [2008]   [May]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [X86] Add recent Centaur CPUs to PAT whitelist
    On Thu, May 22, 2008 at 09:48:44AM -0700, H. Peter Anvin wrote:
    > Dave Jones wrote:
    > > On Wed, May 21, 2008 at 04:56:28PM -0700, H. Peter Anvin wrote:
    > > > Dave Jones wrote:
    > > > >
    > > > > From conversation with Centaur engineers, both the newer generations
    > > > > of the VIA C7, and their future CPUs support PAT, with no known errata.
    > > > >
    > > > > Signed-off-by: Dave Jones <davej@redhat.com>
    > > > >
    > > >
    > > > Question: are there any VIA CPUs that display the PAT CPUID flag that
    > > > aren't covered by the above?
    > >
    > > No. They only added PAT support with the current Esther (C7) generation iirc.
    > >
    >
    > OK, so we should just enable VIA unconditionally as long as PAT is
    > displayed and not worry about generation numbers; same with Transmeta
    > (only the Transmeta Efficeon supported PAT, and it had a
    > strictly-coherent memory system.)

    Like so?

    Unconditionally enable PAT support on Centaur and Transmeta CPUs.
    All known models that advertise PAT have no known errata.

    Signed-off-by: Dave Jones <davej@redhat.com>

    --- linux-2.6/arch/x86/kernel/cpu/addon_cpuid_features.c~ 2008-05-22 12:59:07.000000000 -0400
    +++ linux-2.6/arch/x86/kernel/cpu/addon_cpuid_features.c 2008-05-22 12:59:36.000000000 -0400
    @@ -62,6 +62,9 @@ void __cpuinit validate_pat_support(stru
    if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15))
    return;
    break;
    + case X86_VENDOR_CENTAUR:
    + case X86_VENDOR_TRANSMETA:
    + return;
    }

    pat_disable(cpu_has_pat ?
    --
    http://www.codemonkey.org.uk


    \
     
     \ /
      Last update: 2008-05-22 20:09    [W:0.031 / U:2.684 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site