Device nodes for PCI bridges (both host and P2P) describe both the bridge
device itself and the bus hanging off it, handling of this is a bit of a
mess.
spapr_dt_pci_device() has a few things it only adds for non-bridges, but
always adds #address-cells and #size-cells which should only appear for
bridges. But the walking down the subordinate PCI bus is done in one of
its callers spapr_populate_pci_devices_dt(). The PHB dt creation in
spapr_populate_pci_dt() open codes some similar logic to the bridge case.
This patch consolidates things in a bunch of ways:
* Bus specific dt info is now created in spapr_dt_pci_bus() used for both
P2P bridges and the host bridge. This includes walking subordinate
devices
* spapr_dt_pci_device() now calls spapr_dt_pci_bus() when called on a
P2P bridge
* We do detection of bridges with the is_bridge field of the device class,
rather than checking PCI config space directly, for consistency with
qemu's core PCI code.
* Several things are renamed for brevity and clarity
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>