[RFC/PATCH] powerpc: Use rtas query-cpu-stopped-state in smp spinup

[Nathan Lynch]

Michael Ellerman wrote:
> On Tue, 2006-04-04 at 12:25 -0500, Nathan Lynch wrote:
> 
> > 2. I've tried it before.  Hope I'm remembering this correctly, but I
> >    think my experience was that query-cpu-stopped-state reported
> >    nonsense for cpus that were started by OF.  This was on Power5,
> >    btw.
> 
> That's not what I see, perhaps I have newer firmware?

I tried your patch (non-kexec boot) on a 1-way SMT power5 with
2.6.17-rc1 and got the badness below, and I think it matches what I
ran into in the past.  Maybe doing query-cpu-stopped-state on a thread
that has yet to be started by RTAS mucks things up?

Memory: 2047640k/2097152k available (5356k kernel code, 49512k
reserved, 1412k data, 900k bss, 240k init)
Calibrating delay loop... 375.80 BogoMIPS (lpj=751616)
Security Framework v1.0.0 initialized
SELinux:  Disabled at boot.
Mount-cache hash table entries: 256
Processor 1 is stuck.               <<<<<<<<
Brought up 1 CPUs
Node 0 CPUs: 0
migration_cost=0