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

[Laszlo Ersek <lersek@redhat.com>]

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?

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