pci: Allow PCI bus subtypes to support extended config space accesses

Some PHB implementations, eg. PAPR used on pseries machine, act like
a regular PCI bus rather than a PCIe bus, but allow access to the
PCIe extended config space anyway.

Introduce a new PCI bus class method to modelize this behaviour and
use it when adjusting the config space size limit during accesses.

No behaviour change for existing PCI bus types.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155414130271.574858.4253514266378127489.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
4 files changed