Re: [PATCH 09/14] vfio/mdev: remove mtype_get_parent_dev

[Eric Farman <farman@linux.ibm.com>]

On Fri, 2022-09-23 at 11:26 +0200, Christoph Hellwig wrote:
> Just open code the dereferences in the only user.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>

Reviewed-by: Eric Farman <farman@linux.ibm.com>

> ---
>  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 c37e712a4b069..3db6251b31143 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -62,8 +62,7 @@ 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 75628759a3bf0..93f8caf2e5f77 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 bbedffcb38d48..e445f809ceca3 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;