On Wed, Jun 17, 2015 at 02:45:05PM +0200, Laszlo Ersek wrote:
> SeaBIOS expects OpenFirmware device paths in the "bootorder" fw_cfg file
> to follow the pattern
>
> /pci-root@N/pci@i0cf8/...
It's kind of crazy, isn't it?
/pci@i0cf8/pci-root@N would make some sense: access rootN through cf8.
But if bios needs to keep this for compatibility, maybe
we have too, to. Kevin?
>
> 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 <ke...@koconnor.net>
> Cc: Marcel Apfelbaum <mar...@redhat.com>
> Cc: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
> Tested-by: Marcel Apfelbaum <mar...@redhat.com>
> Reviewed-by: Marcel Apfelbaum <mar...@redhat.com>
This makes this a PC-specific device, which is pretty ugly.
You need to hardcode /pci-root@N here, but why not get
/pci@i0cf8 from the real root?
> ---
>
> Notes:
> v6:
> - no changes
>
> v5:
> - constify parameter and local variables of pxb_host_ofw_unit_address(),
> in accord with the previous patch
>
> 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 4398d98..37574ec 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(const SysBusDevice *dev)
> +{
> + const PCIHostState *host = PCI_HOST_BRIDGE(dev);
> + const PCIBus *bus;
> + const 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);
Please document that this reverse order is to match
existing bios behaviour.
> +}
> +
> 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;
> +}
> +
> static int pxb_dev_initfn(PCIDevice *dev)
> {
> PXBDev *pxb = PXB_DEV(dev);
> @@ -191,9 +219,17 @@ 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),
> @@ -207,6 +243,7 @@ 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;
> --
> 1.8.3.1
