I discovered that in some cases (PowerMac for example) we wouldn't
properly map the PCI IO space on recent kernels. In addition, the code
for initializing PCI host bridges was scattered all over the place with
some duplication between platforms.

This patch fixes the problem and does a small cleanup by creating a
pcibios_alloc_controller() in pci_64.c that is similar to the one in
pci_32.c (just takes an additional device node argument) that takes care
of all the grunt allocation and initialisation work. It should work for
both boot time and dynamically allocated PHBs.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

phbs_remap_io(), which maps the PCI IO space into the kernel virtual space,
is called too early on powermac, and thus doesn't work.

This fixes it by removing the call from all platforms and putting it back
into the ppc64 common code where it belongs, after the actual probing of
the bus.

That means that before that call, only the ISA IO space (if any) is mapped,
any PIO access (from quirks for example) will fail. This happens not to be
a problem for now, but we'll have to rework that code if it becomes one in
the future.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NPaul Mackerras <paulus@samba.org>