[RFC] powerpc: cell interrupt controller updates

[Benjamin Herrenschmidt]

On Tue, 2006-01-17 at 20:28 +0100, Arnd Bergmann wrote:
> The current interrupt controller setup on Cell is done
> in a rather ad-hoc way with device tree properties
> that are not standardized at all.
> 
> In an attempt to do something that follows the OF standard
> (or at least the IBM extensions to it) more closely,
> we have now come up with this patch. It still provides
> a fallback to the old behaviour when we find older firmware,
> that hack can not be removed until the existing customer
> installations have upgraded.
> 
> There are a number of difficulties with this patch:
>  - the detection of interrupt controllers per CPU
>    is also used to detect an SMT setup, with the strange
>    'ibm,interrupt-server-ranges' property.
>  - OF does not currently deal with SMT, the IBM extension
>    for this is specific to the XICS interrupt controller.
>  - The setup on our current boards consists of two
>    actual internal interrupt controllers on the CPUs,
>    which are represented as four logical ones (one per
>    thread), as well as two external 'spiderpic'
>    controllers. In future designs, the spiderpic will
>    be replaced with something else.
>  - ...

The patch alone isn't very "talking" to me. Could you write down the
kind of HW setup you have and how you expressed that in the
device-tree ?

Ben.