Re: [PATCH RFC 04/10] ARM: cortina: Add support for the CS75xx SoC family

[Fil Dunsky <filipp.dunsky@gmail.com>]

On Wed, Sep 30, 2026 at 02:02:43PM +0200, Arnd Bergmann wrote:
> I think I would go with mach-cortina here. Or even better would be
> to find a way not to need any code. If you control the boot loader,
> you could just implement the psci ops there and actually bring
> up the CPU from EL3. If that doesn't work, maybe it is time to
> actually have a generic spin-table implementation on arm32 the
> way we do on arm64. As far as I can tell, your code is just
> a copy of that anyway, though we have so far never added this to
> common arm32 code in order to encourage SoC vendors to use psci.

The boot loader is the stock U-Boot 2009.11 from the router vendor, and
replacing it on these devices is risky enough that I would rather not
depend on it, so PSCI is not really an option here.

A generic spin-table for arm32 would work for me, with two differences
from the arm64 one that it would have to cover: the release address
here is an MMIO register in the global control block, not a word in
memory, so it has to be written with writel() through an ioremap(), and
the Cortex-A9 SCU gets enabled in smp_prepare_cpus() (I have not
checked whether the stock U-Boot already does that). If that sounds
acceptable, I can post it as a separate patch in v2 and drop the
enable method binding and mach directory from this series; otherwise
I will keep the small platsmp.c under the name you and Linus agree on.

> I don't have a strong preference either. If nobody else has a clear
> guidance, changing to "cortina-access,..." would seems the most consistent
> to me.

OK, unless the DT maintainers object I will switch to "cortina-access,"
in v2.

Thanks,
Fil