[3/5] VFIO: platform: add reset callback
diff mbox

Message ID 1431008843-28411-4-git-send-email-eric.auger@linaro.org
State New
Headers show

Commit Message

Eric Auger May 7, 2015, 2:27 p.m. UTC
A new reset callback is introduced. If this callback is populated,
the reset is invoked on device release or upon userspace ioctl. The
modality is exposed on VFIO_DEVICE_GET_INFO.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

v2 -> v3:
- change patch title and commit message. Use IS_ERR_OR_NULL to
  anticipate for getter returned value.

v1 -> v2:
- On VFIO_DEVICE_RESET returns -EINVAL in case the callback is not
  populated (instead of -ENOTTY)
---
 drivers/vfio/platform/vfio_platform_common.c  | 12 ++++++++++--
 drivers/vfio/platform/vfio_platform_private.h |  1 +
 2 files changed, 11 insertions(+), 2 deletions(-)

Comments

Alex Williamson May 13, 2015, 6:32 p.m. UTC | #1
On Thu, 2015-05-07 at 16:27 +0200, Eric Auger wrote:
> A new reset callback is introduced. If this callback is populated,
> the reset is invoked on device release or upon userspace ioctl. The
> modality is exposed on VFIO_DEVICE_GET_INFO.
> 
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> 
> ---
> 
> v2 -> v3:
> - change patch title and commit message. Use IS_ERR_OR_NULL to
>   anticipate for getter returned value.
> 
> v1 -> v2:
> - On VFIO_DEVICE_RESET returns -EINVAL in case the callback is not
>   populated (instead of -ENOTTY)
> ---
>  drivers/vfio/platform/vfio_platform_common.c  | 12 ++++++++++--
>  drivers/vfio/platform/vfio_platform_private.h |  1 +
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index edbf24c..0d10018 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -103,6 +103,8 @@ static void vfio_platform_release(void *device_data)
>  	mutex_lock(&driver_lock);
>  
>  	if (!(--vdev->refcnt)) {
> +		if (!IS_ERR_OR_NULL(vdev->reset))
> +			vdev->reset(vdev);


It seems sloppy to have a function pointer that could be ERR_PTR.

Should we also be trying to reset on device open?

>  		vfio_platform_regions_cleanup(vdev);
>  		vfio_platform_irq_cleanup(vdev);
>  	}
> @@ -162,6 +164,8 @@ static long vfio_platform_ioctl(void *device_data,
>  		if (info.argsz < minsz)
>  			return -EINVAL;
>  
> +		if (!IS_ERR_OR_NULL(vdev->reset))
> +			vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
>  		info.flags = vdev->flags;
>  		info.num_regions = vdev->num_regions;
>  		info.num_irqs = vdev->num_irqs;
> @@ -255,8 +259,12 @@ static long vfio_platform_ioctl(void *device_data,
>  
>  		return ret;
>  
> -	} else if (cmd == VFIO_DEVICE_RESET)
> -		return -EINVAL;
> +	} else if (cmd == VFIO_DEVICE_RESET) {
> +		if (!IS_ERR_OR_NULL(vdev->reset))
> +			return vdev->reset(vdev);
> +		else
> +			return -EINVAL;
> +	}
>  
>  	return -ENOTTY;
>  }
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index 68909a4..84ccf6d 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -68,6 +68,7 @@ struct vfio_platform_device {
>  		(*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);
> +	int	(*reset)(struct vfio_platform_device *vdev);
>  };
>  
>  typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev);



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Eric Auger May 14, 2015, 8:39 a.m. UTC | #2
On 05/13/2015 08:32 PM, Alex Williamson wrote:
> On Thu, 2015-05-07 at 16:27 +0200, Eric Auger wrote:
>> A new reset callback is introduced. If this callback is populated,
>> the reset is invoked on device release or upon userspace ioctl. The
>> modality is exposed on VFIO_DEVICE_GET_INFO.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>
>> ---
>>
>> v2 -> v3:
>> - change patch title and commit message. Use IS_ERR_OR_NULL to
>>   anticipate for getter returned value.
>>
>> v1 -> v2:
>> - On VFIO_DEVICE_RESET returns -EINVAL in case the callback is not
>>   populated (instead of -ENOTTY)
>> ---
>>  drivers/vfio/platform/vfio_platform_common.c  | 12 ++++++++++--
>>  drivers/vfio/platform/vfio_platform_private.h |  1 +
>>  2 files changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
>> index edbf24c..0d10018 100644
>> --- a/drivers/vfio/platform/vfio_platform_common.c
>> +++ b/drivers/vfio/platform/vfio_platform_common.c
>> @@ -103,6 +103,8 @@ static void vfio_platform_release(void *device_data)
>>  	mutex_lock(&driver_lock);
>>  
>>  	if (!(--vdev->refcnt)) {
>> +		if (!IS_ERR_OR_NULL(vdev->reset))
>> +			vdev->reset(vdev);
> 
> 
> It seems sloppy to have a function pointer that could be ERR_PTR.
The reset lookup function currently can return errors. I will change this.
> 
> Should we also be trying to reset on device open?
may be yes. I was influenced by qemu use case where reset is also
explicitly invoked through iotcl by the reset notifier. If we do so we
might have duplicated resets.

- Eric
> 
>>  		vfio_platform_regions_cleanup(vdev);
>>  		vfio_platform_irq_cleanup(vdev);
>>  	}
>> @@ -162,6 +164,8 @@ static long vfio_platform_ioctl(void *device_data,
>>  		if (info.argsz < minsz)
>>  			return -EINVAL;
>>  
>> +		if (!IS_ERR_OR_NULL(vdev->reset))
>> +			vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
>>  		info.flags = vdev->flags;
>>  		info.num_regions = vdev->num_regions;
>>  		info.num_irqs = vdev->num_irqs;
>> @@ -255,8 +259,12 @@ static long vfio_platform_ioctl(void *device_data,
>>  
>>  		return ret;
>>  
>> -	} else if (cmd == VFIO_DEVICE_RESET)
>> -		return -EINVAL;
>> +	} else if (cmd == VFIO_DEVICE_RESET) {
>> +		if (!IS_ERR_OR_NULL(vdev->reset))
>> +			return vdev->reset(vdev);
>> +		else
>> +			return -EINVAL;
>> +	}
>>  
>>  	return -ENOTTY;
>>  }
>> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
>> index 68909a4..84ccf6d 100644
>> --- a/drivers/vfio/platform/vfio_platform_private.h
>> +++ b/drivers/vfio/platform/vfio_platform_private.h
>> @@ -68,6 +68,7 @@ struct vfio_platform_device {
>>  		(*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);
>> +	int	(*reset)(struct vfio_platform_device *vdev);
>>  };
>>  
>>  typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev);
> 
> 
> 

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Patch
diff mbox

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index edbf24c..0d10018 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -103,6 +103,8 @@  static void vfio_platform_release(void *device_data)
 	mutex_lock(&driver_lock);
 
 	if (!(--vdev->refcnt)) {
+		if (!IS_ERR_OR_NULL(vdev->reset))
+			vdev->reset(vdev);
 		vfio_platform_regions_cleanup(vdev);
 		vfio_platform_irq_cleanup(vdev);
 	}
@@ -162,6 +164,8 @@  static long vfio_platform_ioctl(void *device_data,
 		if (info.argsz < minsz)
 			return -EINVAL;
 
+		if (!IS_ERR_OR_NULL(vdev->reset))
+			vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
 		info.flags = vdev->flags;
 		info.num_regions = vdev->num_regions;
 		info.num_irqs = vdev->num_irqs;
@@ -255,8 +259,12 @@  static long vfio_platform_ioctl(void *device_data,
 
 		return ret;
 
-	} else if (cmd == VFIO_DEVICE_RESET)
-		return -EINVAL;
+	} else if (cmd == VFIO_DEVICE_RESET) {
+		if (!IS_ERR_OR_NULL(vdev->reset))
+			return vdev->reset(vdev);
+		else
+			return -EINVAL;
+	}
 
 	return -ENOTTY;
 }
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 68909a4..84ccf6d 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -68,6 +68,7 @@  struct vfio_platform_device {
 		(*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);
+	int	(*reset)(struct vfio_platform_device *vdev);
 };
 
 typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev);