Handling machine check exception

Handling machine check exception

[ganesh subramonian]

Hi,

I am trying to modify the machinecheck exception
handler so that checks caused by data access to a
particular address range can be ignored. In mpc866
there is a register called DAR(Data Address Register)
which gives the address[access to] which caused the
exception. However this is not mentioned in the
MPC8247 manual. Is there some equivalent register for
8247. (It seemed to me that the DAR should be a core
register and hence should be there on 8247 also. but
if i try to read i really dont get the address causing
the error).

Or is there some way i can specify that access to a
particular range of address should not cause a machine
check?? Please help.

thanks
ganesh

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Re: Handling machine check exception

[Matt Sealey]

The G2 core definitely has a DAR register (SPR 19).

Look on the Freescale site for G2CORERM.pdf - this is
your reference manual, not the one specifically for the
8247.

-- 
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations

ganesh subramonian wrote:
> Hi,
> 
> I am trying to modify the machinecheck exception
> handler so that checks caused by data access to a
> particular address range can be ignored. In mpc866
> there is a register called DAR(Data Address Register)
> which gives the address[access to] which caused the
> exception. However this is not mentioned in the
> MPC8247 manual. Is there some equivalent register for
> 8247. (It seemed to me that the DAR should be a core
> register and hence should be there on 8247 also. but
> if i try to read i really dont get the address causing
> the error).
> 
> Or is there some way i can specify that access to a
> particular range of address should not cause a machine
> check?? Please help.
> 
> thanks
> ganesh
> 
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Re: Handling machine check exception

[Benjamin Herrenschmidt]

On Thu, 2006-10-12 at 12:34 +0200, Matt Sealey wrote:
> The G2 core definitely has a DAR register (SPR 19).
> 
> Look on the Freescale site for G2CORERM.pdf - this is
> your reference manual, not the one specifically for the
> 8247.

Is DAR set for a machine check ?

Ben.

Re: Handling machine check exception

[Segher Boessenkool]

>> The G2 core definitely has a DAR register (SPR 19).
>>
>> Look on the Freescale site for G2CORERM.pdf - this is
>> your reference manual, not the one specifically for the
>> 8247.
>
> Is DAR set for a machine check ?

Not on these old cores.


Segher

Re: Handling machine check exception

[ganesh subramonian]

hi
the g2core manual does not say that DAR gets updated
for a machine check exception, but the mpc866um.pdf
manual says so, and it actually does work on my target
board with mpc852t. but no such reference is made in
mpc8272rm.pdf(and dar doesnt get updated on my 8247
based board).

if i cannot find out which address caused the
exception, is there any way by which i can disable
machine check for a particular range of addresses.

thanks
ganesh

--- Segher Boessenkool <segher@kernel.crashing.org>
wrote:

> >> The G2 core definitely has a DAR register (SPR
> 19).
> >>
> >> Look on the Freescale site for G2CORERM.pdf -
> this is
> >> your reference manual, not the one specifically
> for the
> >> 8247.
> >
> > Is DAR set for a machine check ?
> 
> Not on these old cores.
> 
> 
> Segher
> 
> 


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