Re: [Qemu-devel] [PATCH v2 1/2] qdev: Introduce a function to get qbus's parent

[Hu Tao <hutao@cn.fujitsu.com>]

On Thu, Aug 21, 2014 at 05:47:45PM +0800, arei.gonglei@huawei.com wrote:
> From: Gonglei <arei.gonglei@huawei.com>
> 
> We need to use qbus's parent and get its name.
> 
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> ---
>  hw/core/qdev.c         | 7 +++++++
>  include/hw/qdev-core.h | 1 +
>  2 files changed, 8 insertions(+)
> 
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index da1ba48..5c49e08 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -616,6 +616,13 @@ BusState *qbus_create(const char *typename, DeviceState *parent, const char *nam
>      return bus;
>  }
>  
> +DeviceState *qbus_get_parent(BusState *bus)
> +{
> +    DeviceState *parent = bus->parent;
> +
> +    return parent;
> +}

You can return bus->parent directly, or safer:

if (bus) {
    return bus->parent;
}

return NULL;

And, the function is simple enough to make it inline.

> +
>  static char *bus_get_fw_dev_path(BusState *bus, DeviceState *dev)
>  {
>      BusClass *bc = BUS_GET_CLASS(bus);
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index 0799ff2..760e726 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -301,6 +301,7 @@ typedef int (qdev_walkerfn)(DeviceState *dev, void *opaque);
>  void qbus_create_inplace(void *bus, size_t size, const char *typename,
>                           DeviceState *parent, const char *name);
>  BusState *qbus_create(const char *typename, DeviceState *parent, const char *name);
> +DeviceState *qbus_get_parent(BusState *bus);
>  /* Returns > 0 if either devfn or busfn skip walk somewhere in cursion,
>   *         < 0 if either devfn or busfn terminate walk somewhere in cursion,
>   *           0 otherwise. */
> -- 
> 1.7.12.4
> 
>