From: Anton Blanchard <anton@samba.org>

From: Anton Blanchard, Dave Hansen and Olof Johansson:

Fix multiple bugs in the ppc64 NUMA topology probe code.

- We were using HW cpu numbers instead of logical ones.  615, 630, 650,
  some 670 and some 690 SMP will all fail to boot without this patch.

- The old code would BUG() when it got confused (more NUMA zones than the
  kernel is configured for etc).

- The common depth calculation was incorrect.  Dave found an OF property
  that gives us exactly what we want.

- Things were broken on SMT machines.

The new code should work on those broken systems and should no longer BUG()
but fall back to a flat topology when it gets confused.