This looks good, but I've got some minor questions.  First, does
arch/ppc/kernel/cpci405.c need all of those includes?

No, you are right! This would apply to walnut.c also - since I gererated
cpci405.c out of this file.

(And is bios_fixup an init time only function?)

After thinking about this function again, I removed it. On our board PPCBoot
is responsible for pci plug-and-play configuration. If there is still a
problem in this pci setup, we will change PPCBoot instead!

I also tried to make the "ppc405_map_irq" function more generic (since the
number of slots isn't identical for all 405gp boards). Any comments?

 Also do we actually need
include/asm-ppc/cpci405.h?  All it does is include ppcboot.h.  So I'm
guessing this board only boots w/ PPCBOOT, which should include it's own
version of this file.  So is this really needed?

You are right again. At this moment this file isn't needed at all. I thought
that I would need this file perhaps later, when some other boardspecific
defines have to be included (like in tqm8xx.h). Please let me know if you
would still suggest to remove this file.

Please find attached the new (hopefully acceptable) patch against the
linuxppc_2_4_devel tree (2.4.10-pre12) from today.

Best regards,
Stefan