[coreboot] AMD cache setup is broken

Scott Duplichan scott at notabs.org
Tue Sep 14 05:15:32 CEST 2010

]-----Original Message-----
]From: coreboot-bounces+scott=notabs.org at coreboot.org [mailto:coreboot-]bounces+scott=notabs.org at coreboot.org] On Behalf Of Arne
Georg Gleditsch
]Sent: Monday, September 13, 2010 03:51 AM
]To: Scott Duplichan
]Cc: 'Marc Jones'; coreboot at coreboot.org
]Subject: Re: [coreboot] AMD cache setup is broken
]"Scott Duplichan" <scott at notabs.org> writes:
]> I think it would be best to clear bit 35 of msr c001_102a in the AP
]> cores as well as the BSP core. Otherwise, the OS might see AP cores
]> having slightly lower performance than the BSP core. This bit affects
]> family 10h revC and newer (45 nm).
]Ok, so here's a patch adding this.  Clearing bit 35 is done
]unconditionally for all fam10 cpus, is that ok?  Setting is done based
]on processor type in defaults.h, as before.

Thanks. This looks correct to me. I used simnow/tilapia to confirm bit
35 gets cleared in all cores. I found bit 35 never actually gets set.
I submitted a patch to correct that. Once that patch is applied, I can
see bit 35 gets set in all cores, then gets cleared in all cores.


]Signed-off-by: Arne Georg Gleditsch <arne.gleditsch at numascale.com>
]							Arne.

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