Subject: Re: [PATCH 12/38] powerpc/booke: Provide exception macros with interrupt name

From: Scott Wood <[email-masked]>
Date: Wed, 21 Mar 2012 13:19:05 -0500

On 03/21/2012 01:04 PM, Kumar Gala wrote:
> 
> On Feb 28, 2012, at 6:09 PM, Alexander Graf wrote:
> 
>> From: Scott Wood <[email-masked]>
>>
>> DO_KVM will need to identify the particular exception type.
>>
>> There is an existing set of arbitrary numbers that Linux passes,
>> but it's an undocumented mess that sort of corresponds to server/classic
>> exception vectors but not really.
> 
> So what do the new names correspond to?

The names are Linux-defined.  The values are IVOR numbers.

> What header is defining MACHINE_CHECK, BOOKE_INTERRUPT_EXTERNAL, etc
> (asm/kvm_asm.h)?

Yes, it's asm/kvm_asm.h at the moment.

It's actually BOOKE_INTERRUPT_MACHINE_CHECK, etc.  The exception macros
paste on BOOKE_INTERRUPT_ when they use it, to keep the macro users from
having to wrap lines even more often.

> If so we really should move these out of
> asm/kvm_asm.h and into something a bit more appropriate.

Yes, that was one of the things I had been planning to fix post-RFC.
Any preference what header it should be in?  asm/reg_booke.h seems to be
the least bad option of the existing headers -- or perhaps move
head_booke.h to arch/powerpc/include/asm.

Long-term it would also be nice for this to replace, rather than
supplement, the current numbers, though as Ben pointed out there are a
number of places throughout the code that will have to be fixed for that
to happen.

-Scott