[PATCH v4 5/6] ARM: vexpress: DT-based support for Cortex-A5 and Cortex-A9 based tiles

Pawel Moll pawel.moll at arm.com
Wed Dec 7 14:06:28 EST 2011

On Tue, 2011-12-06 at 23:13 +0000, Arnd Bergmann wrote:
> Actually, I have to take that back. Looking at both patch 5 and 6,
> the dt-ca*.c files are almost identical and all the differences are about stuff
> that you can find in the device tree:

You are obviously right - I was rushing with that. Less is better then
more ;-) Will respin tomorrow.

> * The iotable gets initialized from "mrc p15, 4, %0, c15, c0, 0", which would
> be fine if that worked on all machines, but in order to unify the two
> files, I would recommend searching the flat device tree for the respective
> node and only map it if present.
> * You have two ways of finding out the number of cores, but looking in
> the device tree would just work either way.

Those two are actually related, as it's all about memory mapped SCU in
case of A5/A9 and CP15-controlled on A7/15 (the *smp_enable() is
different as well).

I'll probably just define a "scu" node compatible with
"arm,cortex-a9-scu" and use the A5/A9 SMP callbacks if it's present (and
create static mapping for it) or the A7/15 if it's missing.

> * You set the twd_base unconditionally on a5/a9 but never on a7/a15.
> This looks correct, but you could just as well see if a twd node exists
> and use its base address.

I'll reuse Rob's Highbank solution and binding.

> * You only initialize the l2x0 on a5/a9. If a7/a15 don't have a matching
> l2x0 device, then calling the same function unconditionally should be harmless.

Yep, that's not a problem.

Thanks for all the other ack-bys and review-bys!


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