Re: [RFC PATCH v2 3/4] powerpc: refactor of_get_cpu_node to support other architectures

On Sat, Aug 17, 2013 at 11:09:36PM +0100, Benjamin Herrenschmidt wrote:

On Sat, 2013-08-17 at 12:50 +0200, Tomasz Figa wrote:

quoted

I wonder how would this handle uniprocessor ARM (pre-v7) cores, for
which 
the updated bindings[1] define #address-cells = <0> and so no reg 
property.

[1] - http://thread.gmane.org/gmane.linux.ports.arm.kernel/260795

Why did you do that in the binding ? That sounds like looking to create
problems ... 

Traditionally, UP setups just used "0" as the "reg" property on other
architectures, why do differently ?

The decision was taken because we defined our reg property to refer to
the MPIDR register's Aff{2,1,0} bitfields, and on UP cores before v7
there's no MPIDR register at all. Given there can only be a single CPU
in that case, describing a register that wasn't present didn't seem
necessary or helpful.

Thanks,
Mark.