I'm not fully sure about logical vs. virtual addressing in Linux under PowerPC (AMCC 440GX to be precise). From what I've read, it seems like the PowerPC implementation of Linux should not need a HIGH MEMORY distinction and thus all kernel addresses will be logical address. This means, also, that they all have mappings too. Am I right about this?
Also, when it comes to block device drivers that use DMA, how much low-level work must the driver do? Am I done after calling blk_rq_map_sg() or do I need to tickle the 440GX's DMA hardware myself?
Thanks,