On Thu, May 09, 2013 at 10:31:10AM +1000, David Gibson wrote:
> Currently pci_get_primary_bus() searches the list of root buses for one
> with domain 0. But since host buses are always registered with domain 0,
> this just amounts to finding the only PCI host bus.
>
> This simplifies the implementation by defining the primary PCI bus to
> be the first one registered, using a global variable to track it.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
This is the only part that I dislike.
How about an explicit API to set the primary bus?
Let machine types set it.
> ---
> hw/pci/pci.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index a3c192c..b25a1a1 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -96,6 +96,7 @@ struct PCIHostBus {
> QLIST_ENTRY(PCIHostBus) next;
> };
> static QLIST_HEAD(, PCIHostBus) host_buses;
> +static PCIBus *pci_primary_bus;
>
> static const VMStateDescription vmstate_pcibus = {
> .name = "PCIBUS",
> @@ -241,6 +242,12 @@ static int pcibus_reset(BusState *qbus)
> static void pci_host_bus_register(int domain, PCIBus *bus)
> {
> struct PCIHostBus *host;
> +
> + /* If this is the first one, assume it's the primary bus */
> + if (!pci_primary_bus) {
> + pci_primary_bus = bus;
> + }
> +
> host = g_malloc0(sizeof(*host));
> host->domain = domain;
> host->bus = bus;
> @@ -249,15 +256,7 @@ static void pci_host_bus_register(int domain, PCIBus
> *bus)
>
> PCIBus *pci_get_primary_bus(void)
> {
> - struct PCIHostBus *host;
> -
> - QLIST_FOREACH(host, &host_buses, next) {
> - if (host->domain == 0) {
> - return host->bus;
> - }
> - }
> -
> - return NULL;
> + return pci_primary_bus;
> }
>
> PCIBus *pci_device_root_bus(const PCIDevice *d)
> @@ -300,6 +299,7 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent,
>
> /* host bridge */
> QLIST_INIT(&bus->child);
> +
> pci_host_bus_register(0, bus); /* for now only pci domain 0 is supported
> */
>
> vmstate_register(NULL, -1, &vmstate_pcibus, bus);
> --
> 1.7.10.4
