This patch is from Nathan Lynch <nathanl@austin.ibm.com>.

The NUMA properties of all "possible" cpus are not necessarily available at
boot time on ppc64 LPAR.  Only the properties for present cpus are known.

This patch modifies the ppc64 numa code to map a cpu to its node right before
it is brought up -- this means that secondary cpus are now mapped to their
nodes during smp_init().  Cpus are removed from their nodes after they have
gone offline.

Also some minor cleanups:

- Stash the "minimum common depth" in a global at boot time, so we don't
  have to rediscover it every time something changes.

- Remove unnecessary variable from of_get_associativity() which is accessed
  while possibly uninitialized.

- Remove the cpu portion from dump_numa_topology() since it will show only
  the boot cpu now.  We could display this information from smp_cpus_done() if
  necessary.
Signed-off-by: Nathan Lynch <nathanl@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>