[PATCH 6/8] arm: mach-armada: add support for Armada XP board with device tree

On Tue, May 15, 2012 at 04:59:08PM +0100, Ben Dooks wrote:

On 15/05/12 16:41, Russell King - ARM Linux wrote:

quoted

On Tue, May 15, 2012 at 04:07:59PM +0100, Ben Dooks wrote:

quoted

I think it was because that PCI was initialised early and requires a
large mapping space. It is very likely to be legacy kernel stuff that
people have kept copying through.

No.  PCI needs nothing other than access to the configuration space, and
the PCI IO window.  There has _never_ been any hard requirement to map
PCI memory in map_io() because that is _always_ done by drivers calling
ioremap().

What about inb, outb and their related functions?

I said:
| No.  PCI needs nothing other than access to the configuration space, and
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| the PCI IO window.
  ^^^^^^^^^^^^^^^^^^

And, as everyone should know, inb(), outb() etc are the PCI/ISA IO
accessors. So... if you have the PCI IO window mapped, then inb() et.al.
use _that_ window and there isn't a problem.