Re: Fwd: [PATCH] x86, MCE, AMD: save IA32_MCi_STATUS before machine_check_poll() resets it

From: Aravind Gopalakrishnan
Date: Thu Oct 30 2014 - 15:04:29 EST


On 10/29/2014 10:59 AM, Aravind Gopalakrishnan wrote:
On 10/22/2014 4:30 AM, Borislav Petkov wrote:
Hi Aravind,

question: what's the story with MC?_MISC[IntP], is that bit still there?
Because I don't see it in my BKDGs here.

Yep, It exists.
Maybe you are referring to Fam15h M0h BKDG? I think the bit was introduced only from F15h M30h onwards.
The bit does *not* exist for bank=4, But-
if (bank ==4)
return true;

takes care of that.

The background of the story is

https://lkml.org/lkml/2014/10/7/84

There's this thing we did at the time

f227d4306cf3 ("x86, MCE, AMD: Make APIC LVT thresholding interrupt optional")

which, AFAICR, is about some F15h versions having a counter but *not*
generating a thresholding interrupt. Can you confirm that is still
the case and we can have a counter but no interrupt gets generated on
overflow?


So yes, moving the assignment inside the if condition should work just fine.

I see the patch on your 'ras-for-3.19' branch does not have this, so I'll make this modification
to the branch before I test it.


Hi Boris,
I have tested the branch with this bit:

if (b.interrupt_capable) {
... ...
if (mce_threshold_vector != amd_threshold_interrupt)
mce_threshold_vector = amd_threshold_interrupt;
}

and it works fine.

Thanks,
-Aravind.


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