[PATCH] ARM: smp: call platform's cpu_die in ipi_cpu_stop

[Russell King - ARM Linux]

On Sat, Apr 06, 2013 at 03:37:04PM +0300, Kevin Bracey wrote:
> When hotplugging out, both cpu_kill and cpu_die have always been called.
> But when smp_send_stop was used in machine_shutdown or panic, only
> cpu_kill was called.
> 
> This causes problems for co-ordination between cpu_kill and cpu_die, as
> attempted by shmobile. So add cpu_die call to ipi_cpu_stop, to ensure
> that cpu_kill and cpu_die calls always occur together.

Actually, I'd prefer to pull more code out of the platforms.  Now
that we have flush_cache_louis(), we can flush the L1 cache for the
CPU going down in cpu_die() itself.  We just need to be careful
with that complete() call to ensure that becomes visible to other
cores before power is cut to the L1 cache.

That's fine though - because it must become visible for __cpu_die()
to continue (otherwise it will time out).

That should render shmobile's cpu_dead thing unnecessary, because the
platform independent code will do the required synchronisation.