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, 9 insertions, 8 deletions

diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
index b2fa829e29..2a81eec943 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -52,7 +52,8 @@ typedef struct PXBDev {
 
 static PXBDev *convert_to_pxb(PCIDevice *dev)
 {
-    return pci_bus_is_express(dev->bus) ? PXB_PCIE_DEV(dev) : PXB_DEV(dev);
+    return pci_bus_is_express(pci_get_bus(dev))
+        ? PXB_PCIE_DEV(dev) : PXB_DEV(dev);
 }
 
 static GList *pxb_dev_list;
@@ -166,7 +167,7 @@ static const TypeInfo pxb_host_info = {
  */
 static void pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus, Error **errp)
 {
-    PCIBus *bus = dev->bus;
+    PCIBus *bus = pci_get_bus(dev);
     int pxb_bus_num = pci_bus_num(pxb_bus);
 
     if (bus->parent_dev) {
@@ -180,12 +181,12 @@ static void pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus, Error **errp)
             return;
         }
     }
-    QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
+    QLIST_INSERT_HEAD(&pci_get_bus(dev)->child, pxb_bus, sibling);
 }
 
 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
 {
-    PCIDevice *pxb = pci_dev->bus->parent_dev;
+    PCIDevice *pxb = pci_get_bus(pci_dev)->parent_dev;
 
     /*
      * The bios does not index the pxb slot number when
@@ -240,8 +241,8 @@ static void pxb_dev_realize_common(PCIDevice *dev, bool pcie, Error **errp)
     }
 
     bus->parent_dev = dev;
-    bus->address_space_mem = dev->bus->address_space_mem;
-    bus->address_space_io = dev->bus->address_space_io;
+    bus->address_space_mem = pci_get_bus(dev)->address_space_mem;
+    bus->address_space_io = pci_get_bus(dev)->address_space_io;
     bus->map_irq = pxb_map_irq_fn;
 
     PCI_HOST_BRIDGE(ds)->bus = bus;
@@ -272,7 +273,7 @@ err_register_bus:
 
 static void pxb_dev_realize(PCIDevice *dev, Error **errp)
 {
-    if (pci_bus_is_express(dev->bus)) {
+    if (pci_bus_is_express(pci_get_bus(dev))) {
         error_setg(errp, "pxb devices cannot reside on a PCIe bus");
         return;
     }
@@ -324,7 +325,7 @@ static const TypeInfo pxb_dev_info = {
 
 static void pxb_pcie_dev_realize(PCIDevice *dev, Error **errp)
 {
-    if (!pci_bus_is_express(dev->bus)) {
+    if (!pci_bus_is_express(pci_get_bus(dev))) {
         error_setg(errp, "pxb-pcie devices cannot reside on a PCI bus");
         return;
     }