PCIe enhanced configuration mechanism support on ppc arch

Hi,

I'm trying to find out if the current PCI subsystem supports the PCIe
enhanced configuration mechanism, in particular, on the ppc/powerpc
arch, which is basically a MMIO access with the address containing all
bus, device, function, and offset info.

Could someone here give an authoritative answer? Or point me to
somewhere I can look for it by myself, such as which file or directory
in the kernel tree. I searched at arch/ppc/kernel,
arch/powerpc/kernel, and drivers/pci but couldn't find an answer. :(

Thanks,
-Shawn.