Re: [PATCH 2/5] VFIO: platform: add get_device callback

[Eric Auger <eric.auger@linaro.org>]

On 05/13/2015 08:32 PM, Alex Williamson wrote:
> On Thu, 2015-05-07 at 16:27 +0200, Eric Auger wrote:
>> It is needed to introduce a new callback enabling to retrieve the
>> struct device* from the vfio_platform_device. Implementation depends
>> on the underlying device, platform or amba. This will be used to retrieve
>> the compatibility string of the device.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>> ---
>>  drivers/vfio/platform/vfio_amba.c             |  9 +++++++++
>>  drivers/vfio/platform/vfio_platform.c         | 10 ++++++++++
>>  drivers/vfio/platform/vfio_platform_private.h |  1 +
>>  3 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c
>> index ff0331f..fd68115 100644
>> --- a/drivers/vfio/platform/vfio_amba.c
>> +++ b/drivers/vfio/platform/vfio_amba.c
>> @@ -48,6 +48,14 @@ static int get_amba_irq(struct vfio_platform_device *vdev, int i)
>>  	return ret ? ret : -ENXIO;
>>  }
>>  
>> +static struct device *vfio_amba_get_device(struct vfio_platform_device *vdev)
>> +{
>> +	struct amba_device *pdev = (struct amba_device *) vdev->opaque;
>> +	struct device *dev = &pdev->dev;
>> +
>> +	return dev;
>> +}
> 
> *get* device implies a increment in the reference count.  There's
> nothing like that happening here.  Do you just want a to_device wrapper?
Yes you already told that in the past and I should have learnt ...
> Why doesn't struct vfio_platform_device just cache a pointer to the
> struct device?
simpler indeed if agreed.
> 
>> +
>>  static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
>>  {
>>  	struct vfio_platform_device *vdev;
>> @@ -67,6 +75,7 @@ static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
>>  	vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
>>  	vdev->get_resource = get_amba_resource;
>>  	vdev->get_irq = get_amba_irq;
>> +	vdev->get_device = vfio_amba_get_device;
>>  
>>  	ret = vfio_platform_probe_common(vdev, &adev->dev);
>>  	if (ret) {
>> diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
>> index cef645c..c025d76 100644
>> --- a/drivers/vfio/platform/vfio_platform.c
>> +++ b/drivers/vfio/platform/vfio_platform.c
>> @@ -51,6 +51,15 @@ static int get_platform_irq(struct vfio_platform_device *vdev, int i)
>>  	return platform_get_irq(pdev, i);
>>  }
>>  
>> +static struct device *vfio_platform_get_device(
>> +				struct vfio_platform_device *vdev)
>> +{
>> +	struct platform_device *pdev = (struct platform_device *) vdev->opaque;
>> +	struct device *dev = &pdev->dev;
>> +
>> +	return dev;
>> +}
>> +
>>  static int vfio_platform_probe(struct platform_device *pdev)
>>  {
>>  	struct vfio_platform_device *vdev;
>> @@ -65,6 +74,7 @@ static int vfio_platform_probe(struct platform_device *pdev)
>>  	vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
>>  	vdev->get_resource = get_platform_resource;
>>  	vdev->get_irq = get_platform_irq;
>> +	vdev->get_device = vfio_platform_get_device;
>>  
>>  	ret = vfio_platform_probe_common(vdev, &pdev->dev);
>>  	if (ret)
>> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
>> index da2d60b..68909a4 100644
>> --- a/drivers/vfio/platform/vfio_platform_private.h
>> +++ b/drivers/vfio/platform/vfio_platform_private.h
>> @@ -67,6 +67,7 @@ struct vfio_platform_device {
>>  	struct resource*
>>  		(*get_resource)(struct vfio_platform_device *vdev, int i);
>>  	int	(*get_irq)(struct vfio_platform_device *vdev, int i);
>> +	struct device *(*get_device)(struct vfio_platform_device *vdev);
>>  };
>>  
>>  typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev);
> 
> 
>