writel(), readl() in <asm-ppc/io.h>

Hi,

In <asm-ppc/io.h>, writew(), readw(), writel(), and readl() are
defined to little endian access for all platforms unless either
CONFIG_APUS or CONFIG_8260_PCI9 is defined.

Why? Aren't they correct in big endian systems, are they? Maybe I miss
something here.

Regards,
-Shawn.