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

[Russell King - ARM Linux]

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

There is one exception to this: if you have a VGA card in a PCI slot,
it appears by default as an ISA peripheral with the VGA memory
appearing at around PCI_MEM_BASE + 640K or so.  Linux expects that
to already be mapped.

If you're not supporting VGA cards in text mode, that detail doesn't
concern you.