pci: Use helper to find device's root bus in pci_find_domain()

Currently pci_find_domain() performs two functions - it locates the PCI
root bus above the given bus, then looks up that root bus's domain number.
This patch adds a helper function to perform the first task, finding the
root bus for a given PCI device.  This is then used in pci_find_domain().
This changes pci_find_domain()'s signature slightly, taking a PCIDevice
instead of a PCIBus - since all callers passed something of the form
dev->bus, this simplifies things slightly.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 7b89d88106..f2bf1edbd9 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -390,7 +390,8 @@ void pci_for_each_device(PCIBus *bus, int bus_num,
                          void (*fn)(PCIBus *bus, PCIDevice *d, void *opaque),
                          void *opaque);
 PCIBus *pci_find_primary_bus(void);
-int pci_find_domain(const PCIBus *bus);
+PCIBus *pci_device_root_bus(const PCIDevice *d);
+int pci_find_domain(const PCIDevice *dev);
 PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn);
 int pci_qdev_find_device(const char *id, PCIDevice **pdev);
 PCIBus *pci_get_bus_devfn(int *devfnp, const char *devaddr);