Possible regression in kexec on ARM ARMv6 and ARMv7 cores

[Will Deacon]

On Fri, Oct 21, 2011 at 09:34:26AM +0100, Simon Horman wrote:
> I have tested the kexec/mmu-off branch of your tree on the UP board
> I mentioned above and kexec works :)

Hurrah! Thanks for giving it a spin.

> > You mention UP in particular, which I will test.
> > Do you have any thoughts on SMP?

Yes. Currently [i.e. on my branch above] you can do SMP kexec using the CPU
hotplug platform_cpu_kill callback to take down the CPUs in some
platform-specific manner.

The more difficult case is when you want to offline the secondary CPUs into
a pen and then boot them in the new kernel. I did get some of this working,
but there are outstanding issues with whether the pen should be at a fixed
location or not. If not, then we need a way to tell the new kernel where it
is, which may involve updating the DT blob...

Will