PCIe enhanced configuration mechanism support on ppc arch

[Segher Boessenkool]

> An example of platform not using RTAS and that does support extended
> config space is the PCI Express link out of the U4 northbridge on
> PowerMac (though not the other PCIe slots connected to the HT<->PCIe
> tunnel, at least not for now).
>
> It's basically just a matter of having your low level config access
> routines supporting those >=256 offsets. The generic code tests  
> that by
> doing a dummy access and checks for an error return.

The U3/U4 HT config access code never returns the error though; it
happily accesses the config space of the next device instead.  Got
a patch, will send it later -- it's not a regression, there's no big
hurry for 2.6.18.


Segher