[PATCH 4/6] arm64: topology: Implement basic CPU topology support

[Catalin Marinas]

On Wed, Dec 11, 2013 at 02:30:18PM +0000, Mark Brown wrote:
> On Wed, Dec 11, 2013 at 02:24:32PM +0000, Catalin Marinas wrote:
> > On Wed, Dec 11, 2013 at 02:15:03PM +0000, Mark Brown wrote:
> 
> > > He said he hadn't had time to work on the actual implementation which is
> > > why I picked this up - as far as I'm aware we only have the (already
> > > merged) binding for this.
> 
> > Lorenzo (on holiday now) pushed the DT topology bindings but there are
> > no patches yet for reading them. I would much prefer to only describe
> > the topology via DT rather than MPIDR (because hardware people sometimes
> > have strange ideas).
> 
> Right, that was my understanding too.  
> 
> For clarity the current code only uses DT information, the MPIDR values
> it uses are those in the CPU nodes in the DT which are used by the SMP
> code and are not read from the hardware.

But these must match the hardware MPIDR to be useful on SMP. So whether
you read them from hardware or DT, they are still the same.

> We can drop that bit of code
> easily enough but it seemed useful for getting the scaffolding in place
> separately to the binding parsing and for general robustness, perhaps
> adding a patch at the end of the series to drop the code handling MPIDR
> would deal with the application issues?

Can we have the topology infrastructure with a flat initial topology and
the actual building in a separate patch?

-- 
Catalin