Commit 09e5b819 authored by Marcel Apfelbaum's avatar Marcel Apfelbaum Committed by Michael S. Tsirkin
Browse files

hw/pci: extend PCI config access to support devices behind PXB 



PXB buses are assumed to be children of bus 0. Look for them
while scanning the buses.

Signed-off-by: default avatarMarcel Apfelbaum <marcel@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarLaszlo Ersek <lersek@redhat.com>
parent ca6c1855

hw/pci/pci.c

+29 −5
Original line number Diff line number Diff line
@@ -1699,10 +1699,28 @@ static bool pci_secondary_bus_in_range(PCIDevice *dev, int bus_num) 
{

    return !(pci_get_word(dev->config + PCI_BRIDGE_CONTROL) &

             PCI_BRIDGE_CTL_BUS_RESET) /* Don't walk the bus if it's reset. */ &&

        dev->config[PCI_SECONDARY_BUS] < bus_num &&

        dev->config[PCI_SECONDARY_BUS] <= bus_num &&

        bus_num <= dev->config[PCI_SUBORDINATE_BUS];

}



/* Whether a given bus number is in a range of a root bus */

static bool pci_root_bus_in_range(PCIBus *bus, int bus_num)

{

    int i;



    for (i = 0; i < ARRAY_SIZE(bus->devices); ++i) {

        PCIDevice *dev = bus->devices[i];



        if (dev && PCI_DEVICE_GET_CLASS(dev)->is_bridge) {

            if (pci_secondary_bus_in_range(dev, bus_num)) {

                return true;

            }

        }

    }



    return false;

}



static PCIBus *pci_find_bus_nr(PCIBus *bus, int bus_num)

{

    PCIBus *sec;
@@ -1724,15 +1742,21 @@ static PCIBus *pci_find_bus_nr(PCIBus *bus, int bus_num) 
    /* try child bus */

    for (; bus; bus = sec) {

        QLIST_FOREACH(sec, &bus->child, sibling) {

            assert(!pci_bus_is_root(sec));

            if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) {

            if (pci_bus_num(sec) == bus_num) {

                return sec;

            }

            /* PXB buses assumed to be children of bus 0 */

            if (pci_bus_is_root(sec)) {

                if (pci_root_bus_in_range(sec, bus_num)) {

                    break;

                }

            } else {

                if (pci_secondary_bus_in_range(sec->parent_dev, bus_num)) {

                    break;

                }

            }

        }

    }



    return NULL;

}