Re: [Qemu-devel] [PATCH v4 4/4] hw/pci-bridge: format SeaBIOS-compliant OFW device node for PXB

[Marcel Apfelbaum <marcel@redhat.com>]

On 06/13/2015 04:52 PM, Laszlo Ersek wrote:
> SeaBIOS expects OpenFirmware device paths in the "bootorder" fw_cfg file
> to follow the pattern
>
>    /pci-root@N/pci@i0cf8/...
>
> for devices that live behind an extra root bus. The extra root bus in
> question is the N'th among the extra root bridges. (In other words, N
> gives the position of the affected extra root bus relative to the other
> extra root buses, in bus_nr order.) N starts at 1, and is formatted in
> hex.
>
> The "pci@i0cf8" node text is hardcoded in SeaBIOS (see the macro
> FW_PCI_DOMAIN).
>
> Cc: Kevin O'Connor <kevin@koconnor.net>
> Cc: Marcel Apfelbaum <marcel@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>
> Notes:
>      v4:
>      - new in v4
>
>   hw/pci-bridge/pci_expander_bridge.c | 39 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
> index c7a085d..bed8ec9 100644
> --- a/hw/pci-bridge/pci_expander_bridge.c
> +++ b/hw/pci-bridge/pci_expander_bridge.c
> @@ -42,6 +42,8 @@ typedef struct PXBDev {
>       uint16_t numa_node;
>   } PXBDev;
>
> +static GList *pxb_dev_list;
> +
>   #define TYPE_PXB_HOST "pxb-host"
>
>   static int pxb_bus_num(PCIBus *bus)
> @@ -88,12 +90,29 @@ static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
>       return bus->bus_path;
>   }
>
> +static char *pxb_host_ofw_unit_address(SysBusDevice *dev)
> +{
> +    PCIHostState *host = PCI_HOST_BRIDGE(dev);
> +    PCIBus *bus;
> +    PXBDev *pxb;
> +    int position;
> +
> +    bus = host->bus;
> +    pxb = PXB_DEV(bus->parent_dev);
> +    position = g_list_index(pxb_dev_list, pxb);
> +    assert(position >= 0);
> +
> +    return g_strdup_printf("%x/pci@i0cf8", position + 1);
> +}
> +
>   static void pxb_host_class_init(ObjectClass *class, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(class);
> +    SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(class);
>       PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
>
> -    dc->fw_name = "pci";
> +    dc->fw_name = "pci-root";
> +    sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
>       hc->root_bus_path = pxb_host_root_bus_path;
>   }
>
> @@ -148,6 +167,15 @@ static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
>       return pin - PCI_SLOT(pxb->devfn);
>   }
>
> +static gint pxb_compare(gconstpointer a, gconstpointer b)
> +{
> +    const PXBDev *pxb_a = a, *pxb_b = b;
> +
> +    return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
> +           pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
> +           0;
> +}
return pxb_a->bus_nr - pxb_b->bus_nr ? :)

This will not hold the series... I can send a patch on top.


Thanks,
Marcel

> +
>   static int pxb_dev_initfn(PCIDevice *dev)
>   {
>       PXBDev *pxb = PXB_DEV(dev);
> @@ -190,9 +218,17 @@ static int pxb_dev_initfn(PCIDevice *dev)
>                                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
>       pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
>
> +    pxb_dev_list = g_list_insert_sorted(pxb_dev_list, pxb, pxb_compare);
>       return 0;
>   }
>
> +static void pxb_dev_exitfn(PCIDevice *pci_dev)
> +{
> +    PXBDev *pxb = PXB_DEV(pci_dev);
> +
> +    pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
> +}
> +
>   static Property pxb_dev_properties[] = {
>       /* Note: 0 is not a legal a PXB bus number. */
>       DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
> @@ -206,6 +242,7 @@ static void pxb_dev_class_init(ObjectClass *klass, void *data)
>       PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>
>       k->init = pxb_dev_initfn;
> +    k->exit = pxb_dev_exitfn;
>       k->vendor_id = PCI_VENDOR_ID_REDHAT;
>       k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
>       k->class_id = PCI_CLASS_BRIDGE_HOST;
>