On Wed, Nov 24, 2010 at 07:27:58AM +0200, Michael S. Tsirkin wrote:
> Right. So let's add an inline helper to avoid code duplication here?
>
> pci: fix bus walk under secondary bus reset
>
> Take into account secondary bus reset bit for
> bus walk: devices behind a reset bus should not
> respond to configuration cycles.
>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
>
>
> diff --git a/hw/pci.c b/hw/pci.c
> index d02f980..0c15b13 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -1540,6 +1540,16 @@ void pci_bridge_update_mappings(PCIBus *b)
> }
> }
>
> +/* Whether a given bus number is in range of the secondary
> + * bus of the given bridge device. */
> +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 &&
> + bus_num <= dev->config[PCI_SUBORDINATE_BUS];
> +}
> +
> PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
> {
> PCIBus *sec;
> @@ -1552,20 +1562,21 @@ PCIBus *pci_find_bus(PCIBus *bus, int bus_num)
> return bus;
> }
>
> + /* Consider all bus numbers in range for the host pci bridge. */
> + if (bus->parent_dev &&
> + !pci_secondary_bus_in_range(bus->parent_dev, bus_num)) {
> + return NULL;
> + }
> +
> /* try child bus */
> - if (!bus->parent_dev /* host pci bridge */ ||
> - (bus->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
> - bus_num <= bus->parent_dev->config[PCI_SUBORDINATE_BUS])) {
> - for (; bus; bus = sec) {
> - QLIST_FOREACH(sec, &bus->child, sibling) {
> - assert(sec->parent_dev);
> - if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) {
> - return sec;
> - }
> - if (sec->parent_dev->config[PCI_SECONDARY_BUS] < bus_num &&
> - bus_num <= sec->parent_dev->config[PCI_SUBORDINATE_BUS])
> {
> - break;
> - }
> + for (; bus; bus = sec) {
> + QLIST_FOREACH(sec, &bus->child, sibling) {
> + assert(sec->parent_dev);
> + if (sec->parent_dev->config[PCI_SECONDARY_BUS] == bus_num) {
> + return sec;
> + }
> + if (pci_secondary_bus_in_range(sec->parent_dev, bus_num)) {
This condition should be "if (!pci_...)"
> + break;
> }
> }
> }
>
> > --
> > yamahata
>
--
yamahata
