PPC beginner questions

  I'm new to the PPC and I have a few questions.  I have written a  driver
in the past for the X86 family, using i/o ports, but it was kernel 2.0 and
i/o ports are not mmu handled.
  I've been looking through the archive and I am slowly growing more
confused.

  We are using Xilinx with PPC built in.

   The PPC has a memory management unit.  All of the IP we've added is
mapped to physical addresses.

   1. Can I access the memory the peripherasl are mapped to directly within
the driver without going through functions?
       if NOT, then Do I use
          1. ioremap(),
          2. request_mem_region(),
          3. request_region()
          4. something else?

   2.  Are there any gotcha's with the ppc 405 that Xilinx uses that I
should know about?


thanks,
wade