The main thrust of this patch is to make the ppc32 PCI code more
robust by checking for bus->resource[] being NULL before using it.  We
can legitimately get elements of bus->resource being NULL and I have
actually hit that on some machines.  This patch also allows resources
starting at 0 to be accepted as assigned (we can and do get PCI
resources starting at 0 in I/O space on PPC machines) and provides a
sensible default for the case where Open Firmware doesn't give us a
bus-range property for a PCI bridge.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>