Create an inline function to extract the pnode from a global
physical address and then convert the broadcast assist unit to
use the newly created uv_gpa_to_pnode function.

The open-coded code was wrong as well - it might explain a
few of our unexplained bau hangs.
Signed-off-by: NRobin Holt <holt@sgi.com>
Acked-by: NCliff Whickman <cpw@sgi.com>
Cc: linux-mm@kvack.org
Cc: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20091016112920.GZ8903@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>