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@xxxxxxxxxx>
>>
>> ---
>>
>> 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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