[PATCH] add restart function for mpc52xx

[Paul Mackerras]

Sascha Hauer writes:

> > This suffers from the same bug mpc83xx_restart has.  We can NOT do an  
> > ioremap inside the restart function.  We may get called from  
> > interrupt context on a panic and will not be able to do the ioremap 
> > ().  The simplest thing is to do the mapping earlier in an init call  
> > and save the pointer, its not perfect, but better.
> > 
> 
> I'm beginning to hate this whole pseudo OF thing for embedded systems.

Not being able to ioremap at interrupt time has absolutely _nothing_
to do with the device tree.

> All we need to know is that we have a mpc52xx processor.

... until we get a system with a mpc52xx and some extra stuff.  Then
you say "OK, we just need a boardinfo_t" and then we get 57 different
variants of boardinfo_t and then we're back in the mess that arch/ppc
got into.

Paul.