ARM: static kernel in vmalloc space

[Linus Walleij]

On Fri, May 15, 2020 at 5:41 PM Arnd Bergmann <arnd at arndb.de> wrote:

[Russell]
> > There are some aliasing VIPT implementations on ARMv6, but I don't
> > remember how common.
>
> I thought it was only realview-pb and omap2, but it seems there
> are more, at least ast2500 is an important example.
>
> I could not find information about integrator-cp and picoxcell.
(...)
>   integrator CM1136JF-S core module: arm1136r?, 16kb non-aliasing VIPT
> ? integrator CTB36 core tile: arm1136r?, ???

These do exist, the Integrators have pluggable CPU core modules.
What you do is populate the core module slot on the Integrator CP
with a CM1136.

That said, I think I am the only user of the Integrator/CP actual
hardware. And I don't have this core module. So I think it will be
safe to drop support for that specific VIPT implementation by the
token that if a tree falls in the forest and noone
is there to hear it, it does not make a sound.

As for physically existing VIPT 1136/1176 systems the Ambarella
legacy SoCs that are not upstream is the big consumer of these.

Ambarella's main customer is GoPro cameras and similar
products. I have no idea if they ever upgrade kernels on these
things though, I think not, but it would be great if someone knows
them and can ask whether this is a concern for them. (They
should be working with the community IMO, but is one of those
companies that for some reason do not.)

Yours,
Linus Walleij