Re: [Qemu-devel] [PATCH v7 10/10] hw/pci-bridge: format special OFW unit address for PXB host

[Marcel Apfelbaum <marcel@redhat.com>]

On 06/24/2015 10:01 AM, Laszlo Ersek wrote:
> On 06/24/15 07:40, Michael S. Tsirkin wrote:
>> On Fri, Jun 19, 2015 at 04:40:17AM +0200, Laszlo Ersek wrote:
>>> We have agreed that OpenFirmware device paths in the "bootorder" fw_cfg
>>> file should follow the pattern
>>>
>>>    /pci@i0cf8,%x/...
>>>
>>> for devices that live behind an extra root bus. The extra root bus in
>>> question is the %x'th among the extra root buses. (In other words, %x
>>> gives the position of the affected extra root bus relative to the other
>>> extra root buses, in bus_nr order.) %x starts at 1, and is formatted in
>>> hex.
>>>
>>> The portion of the unit address that comes before the comma is dynamically
>>> taken from the main host bridge, similarly to sysbus_get_fw_dev_path().
>>>
>>> Cc: Kevin O'Connor <kevin@koconnor.net>
>>> Cc: Michael S. Tsirkin <mst@redhat.com>
>>> Cc: Marcel Apfelbaum <marcel@redhat.com>
>>> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
>>
>> So as I said, a global pxb_dev_list is ugly, and we do not want
>> duplicate data structures - please scan child devices of parent instead.
>> Functionally correct, so can be a patch on top.
>
> Marcel, can you pick this up please?
Sure thing, thank you for your patches!
I'll take care of this,
Marcel

>
> Thanks
> Laszlo
>
>>
>>
>>> ---
>>>
>>> Notes:
>>>      v7:
>>>      - implement the format that both Kevin and Michael agreed with. Example:
>>>        /pci@i0cf8,1/pci-bridge@0/scsi@0/channel@0/disk@0,0
>>>      - I updated the OVMF patchset accordingly, but I won't post it until
>>>        this QEMU patch is applied
>>>      - Someone please write the SeaBIOS patch
>>>
>>>      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 | 53 +++++++++++++++++++++++++++++++++++++
>>>   1 file changed, 53 insertions(+)
>>>
>>> diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
>>> index 70708ef..57f8a37 100644
>>> --- a/hw/pci-bridge/pci_expander_bridge.c
>>> +++ b/hw/pci-bridge/pci_expander_bridge.c
>>> @@ -43,6 +43,8 @@ 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)
>>> @@ -89,12 +91,45 @@ 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 *pxb_host;
>>> +    const PCIBus *pxb_bus;
>>> +    const PXBDev *pxb_dev;
>>> +    int position;
>>> +    const DeviceState *pxb_dev_base;
>>> +    const PCIHostState *main_host;
>>> +    const SysBusDevice *main_host_sbd;
>>> +
>>> +    pxb_host = PCI_HOST_BRIDGE(dev);
>>> +    pxb_bus = pxb_host->bus;
>>> +    pxb_dev = PXB_DEV(pxb_bus->parent_dev);
>>> +    position = g_list_index(pxb_dev_list, pxb_dev);
>>> +    assert(position >= 0);
>>> +
>>> +    pxb_dev_base = DEVICE(pxb_dev);
>>> +    main_host = PCI_HOST_BRIDGE(pxb_dev_base->parent_bus->parent);
>>> +    main_host_sbd = SYS_BUS_DEVICE(main_host);
>>> +
>>> +    if (main_host_sbd->num_mmio > 0) {
>>> +        return g_strdup_printf(TARGET_FMT_plx ",%x",
>>> +                               main_host_sbd->mmio[0].addr, position + 1);
>>> +    }
>>> +    if (main_host_sbd->num_pio > 0) {
>>> +        return g_strdup_printf("i%04x,%x",
>>> +                               main_host_sbd->pio[0], position + 1);
>>> +    }
>>> +    return NULL;
>>> +}
>>> +
>>>   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";
>>> +    sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
>>>       hc->root_bus_path = pxb_host_root_bus_path;
>>>   }
>>>
>>> @@ -149,6 +184,15 @@ 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);
>>> @@ -192,9 +236,17 @@ 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),
>>> @@ -208,6 +260,7 @@ 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
>