[1/3] hw/pci-bridge: modify pxb_dev_init_common

1) add Error **errp parameter for it,
2) rename pxb_dev_init_common to pxb_dev_realize_common,
   and prepare for pxb/pxb-pcie convert to realize.
3) modify the callers,
   including pxb_dev_initfn and pxb_pcie_dev_initfn.

Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com>
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
---
 hw/pci-bridge/pci_expander_bridge.c | 56 ++++++++++++++++++++++++-------------
 1 file changed, 37 insertions(+), 19 deletions(-)

Wei Jiangang <weijg.fnst@cn.fujitsu.com> writes:

> 1) add Error **errp parameter for it,
> 2) rename pxb_dev_init_common to pxb_dev_realize_common,
>    and prepare for pxb/pxb-pcie convert to realize.
> 3) modify the callers,
>    including pxb_dev_initfn and pxb_pcie_dev_initfn.
>
> Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com>
> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>

The first line of your commit message is inexpressive.  Suggest

    hw/pci-bridge: Convert to pxb_dev_init_common() to Error

    The next commits will convert its users to realize(), so rename it
    to pxb_dev_realize_common() now.

The patch actually converts pxb_register_bus() as well, but that's
detail.

> ---
>  hw/pci-bridge/pci_expander_bridge.c | 56 ++++++++++++++++++++++++-------------
>  1 file changed, 37 insertions(+), 19 deletions(-)
>
> diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
> index d23b8da..ce5baf8 100644
> --- a/hw/pci-bridge/pci_expander_bridge.c
> +++ b/hw/pci-bridge/pci_expander_bridge.c
> @@ -160,30 +160,25 @@ static const TypeInfo pxb_host_info = {
>  };
>  
>  /*
> - * Registers the PXB bus as a child of the i440fx root bus.
> - *
> - * Returns 0 on successs, -1 if i440fx host was not
> - * found or the bus number is already in use.
> + * Registers the PXB bus as a child of pci host root bus.
>   */
> -static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
> +static void pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus, Error **errp)
>  {
>      PCIBus *bus = dev->bus;
>      int pxb_bus_num = pci_bus_num(pxb_bus);
>  
>      if (bus->parent_dev) {
> -        error_report("PXB devices can be attached only to root bus.");
> -        return -1;
> +        error_setg(errp, "PXB devices can be attached only to root bus.");

While there, drop the period (error messages generally don't end in
punctuation).  More of the same below.

> +        return;
>      }
>  
>      QLIST_FOREACH(bus, &bus->child, sibling) {
>          if (pci_bus_num(bus) == pxb_bus_num) {
> -            error_report("Bus %d is already in use.", pxb_bus_num);
> -            return -1;
> +            error_setg(errp, "Bus %d is already in use.", pxb_bus_num);
> +            return;
>          }
>      }
>      QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
> -
> -    return 0;
>  }
>  
>  static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
> @@ -213,7 +208,7 @@ static gint pxb_compare(gconstpointer a, gconstpointer b)
>             0;
>  }
>  
> -static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
> +static void pxb_dev_realize_common(PCIDevice *dev, bool pcie, Error **errp)
>  {
>      PXBDev *pxb = convert_to_pxb(dev);
>      DeviceState *ds, *bds = NULL;
> @@ -222,8 +217,8 @@ static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
>  
>      if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
>          pxb->numa_node >= nb_numa_nodes) {
> -        error_report("Illegal numa node %d.", pxb->numa_node);
> -        return -EINVAL;
> +        error_setg(errp, "Illegal numa node %d.", pxb->numa_node);
> +        return;
>      }
>  
>      if (dev->qdev.id && *dev->qdev.id) {
> @@ -248,8 +243,9 @@ static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
>  
>      PCI_HOST_BRIDGE(ds)->bus = bus;
>  
> -    if (pxb_register_bus(dev, bus)) {
> -        return -EINVAL;
> +    pxb_register_bus(dev, bus, errp);
> +    if (*errp) {

Breaks when a caller passes a null errp.  You have to do

       pxb_register_bus(dev, bus, &err);
       if (err) {
           error_propagate(errp, err);

with err previously initialized to null.

See also the big comment in error.h.

> +        goto err_register_bus;
>      }
>  
>      qdev_init_nofail(ds);
> @@ -262,17 +258,31 @@ static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
>      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;
> +
> +    return;
> +
> +err_register_bus:
> +    object_unref(OBJECT(bds));
> +    object_unparent(OBJECT(bus));
> +    object_unref(OBJECT(ds));

Cleanup new in this patch.  Is this a bug fix?  If yes, the commit
message should mention it.  I'd make it a separate patch, before this one.

>  }
>  
>  static int pxb_dev_initfn(PCIDevice *dev)
>  {
> +    Error *err = NULL;
> +
>      if (pci_bus_is_express(dev->bus)) {
>          error_report("pxb devices cannot reside on a PCIe bus!");
>          return -EINVAL;
>      }
>  
> -    return pxb_dev_init_common(dev, false);
> +    pxb_dev_realize_common(dev, false, &err);
> +    if (err) {
> +        error_report_err(err);
> +        return -EINVAL;
> +    }
> +
> +    return 0;
>  }
>  
>  static void pxb_dev_exitfn(PCIDevice *pci_dev)
> @@ -314,12 +324,20 @@ static const TypeInfo pxb_dev_info = {
>  
>  static int pxb_pcie_dev_initfn(PCIDevice *dev)
>  {
> +    Error *err = NULL;
> +
>      if (!pci_bus_is_express(dev->bus)) {
>          error_report("pxb-pcie devices cannot reside on a PCI bus!");
>          return -EINVAL;
>      }
>  
> -    return pxb_dev_init_common(dev, true);
> +    pxb_dev_realize_common(dev, true, &err);
> +    if (err) {
> +        error_report_err(err);
> +        return -EINVAL;
> +    }
> +
> +    return 0;
>  }
>  
>  static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)