pci: Eliminate redundant PCIDevice::bus pointer

The bus pointer in PCIDevice is basically redundant with QOM information.
It's always initialized to the qdev_get_parent_bus(), the only difference
is the type.

Therefore this patch eliminates the field, instead creating a pci_get_bus()
helper to do the type mangling to derive it conveniently from the QOM
Device object underneath.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index a0fb1ce037..8b703455b7 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -460,9 +460,9 @@ static void piix4_pm_machine_ready(Notifier *n, void *opaque)
         (memory_region_present(io_as, 0x2f8) ? 0x90 : 0);
 
     if (s->use_acpi_pci_hotplug) {
-        pci_for_each_bus(d->bus, piix4_update_bus_hotplug, s);
+        pci_for_each_bus(pci_get_bus(d), piix4_update_bus_hotplug, s);
     } else {
-        piix4_update_bus_hotplug(d->bus, s);
+        piix4_update_bus_hotplug(pci_get_bus(d), s);
     }
 }
 
@@ -535,7 +535,8 @@ static void piix4_pm_realize(PCIDevice *dev, Error **errp)
     qemu_add_machine_init_done_notifier(&s->machine_ready);
     qemu_register_reset(piix4_reset, s);
 
-    piix4_acpi_system_hot_add_init(pci_address_space_io(dev), dev->bus, s);
+    piix4_acpi_system_hot_add_init(pci_address_space_io(dev),
+                                   pci_get_bus(dev), s);
 
     piix4_pm_add_propeties(s);
 }