On Fri, Jun 20, 2014 at 08:05:23PM +0200, Borislav Petkov wrote:
> On Fri, Jun 20, 2014 at 10:47:22AM -0700, H. Peter Anvin wrote:
> > This is run before static_cpu_has().
>
> static_cpu_has_safe() then - I didn't do it for no reason :-)
>
> > The point, though, was that we "enforce" (taint) on 32 bits but not on
> > 64 bits, which is clearly wrong.
>
> Yeah, K7 is 32-bit only.
>
> > My inclination is to completely kill amd_k7_smp_check() entirely,
> > since noone seems to know when it actually matters and it is clearly
> > historic.
>
> I think DaveJ should know something about it - he gave that impression
> last time when we were discussing 8c90487cdc64 ("Rename TAINT_UNSAFE_SMP
> to TAINT_CPU_OUT_OF_SPEC").
AMD sold two separate SKUs: the Athlon XP and the Athlon MP.
Only the latter was supposedly "certified" for use in multi-processor
boards. People found out however that sometimes the XP's 'worked'
if you modded them (see
http://www.hardwaresecrets.com/article/How-to-Transform-an-Athlon-XP-into-an-Athlon-MP/24)
There was belief that AMD had reason beyond "more price mark-up for MP's"
and that those fuses had been blown for good reason (failing validation
in some conditions for eg).
I doubt anyone is actually even running such a system any more on
a modern kernel, and any weird crashes would be written off more by
"you're running 10+ year old hardware, it's probably broken" than
"it was never meant to do that".
Dave
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
