Re: [PATCH 08/13] vfio/mdev: remove mtype_get_parent_dev

[Kirti Wankhede <kwankhede@xxxxxxxxxx>]

On 6/14/2022 10:24 AM, Christoph Hellwig wrote:
> Just open code the dereferences in the only user.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>

Reviewed-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>

> ---
>   drivers/s390/cio/vfio_ccw_ops.c |  3 +--
>   drivers/vfio/mdev/mdev_core.c   | 10 ----------
>   include/linux/mdev.h            |  2 --
>   3 files changed, 1 insertion(+), 14 deletions(-)
>
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
> index 25b8d42a522ac..43d53736dfe3c 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -88,8 +88,7 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
>   					struct mdev_type_attribute *attr,
>   					char *buf)
>   {
> -	struct vfio_ccw_private *private =
> -		dev_get_drvdata(mtype_get_parent_dev(mtype));
> +	struct vfio_ccw_private *private = dev_get_drvdata(mtype->parent->dev);
>   
>   	return sprintf(buf, "%d\n", atomic_read(&private->avail));
>   }
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index 479ae5ed6c392..20513b7f6b5eb 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -23,16 +23,6 @@ static struct class_compat *mdev_bus_compat_class;
>   static LIST_HEAD(mdev_list);
>   static DEFINE_MUTEX(mdev_list_lock);
>   
> -/*
> - * Used in mdev_type_attribute sysfs functions to return the parent struct
> - * device
> - */
> -struct device *mtype_get_parent_dev(struct mdev_type *mtype)
> -{
> -	return mtype->parent->dev;
> -}
> -EXPORT_SYMBOL(mtype_get_parent_dev);
> -
>   /* Caller must hold parent unreg_sem read or write lock */
>   static void mdev_device_remove_common(struct mdev_device *mdev)
>   {
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 83c85a0247f25..ecf964d34f2ca 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -51,8 +51,6 @@ static inline struct mdev_device *to_mdev_device(struct device *dev)
>   	return container_of(dev, struct mdev_device, dev);
>   }
>   
> -struct device *mtype_get_parent_dev(struct mdev_type *mtype);
> -
>   /* interface for exporting mdev supported type attributes */
>   struct mdev_type_attribute {
>   	struct attribute attr;