as1_readb         260 arch/powerpc/kernel/udbg_16550.c 	return as1_readb((void __iomem *)PPC44x_EARLY_DEBUG_VIRTADDR + reg);
as1_readb           5 arch/powerpc/platforms/44x/44x.h extern u8 as1_readb(volatile u8 __iomem  *addr);