RE: [PATCH 06/18] vfio/mdev: Expose mdev_get/put_parent to mdev_private.h

["Tian, Kevin" <kevin.tian@intel.com>]

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Wednesday, March 24, 2021 1:55 AM
> 
> The next patch will use these in mdev_sysfs.c
> 
> While here remove the now dead code checks for NULL, a mdev_type can
> never
> have a NULL parent.
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

> ---
>  drivers/vfio/mdev/mdev_core.c    | 23 +++--------------------
>  drivers/vfio/mdev/mdev_private.h | 12 ++++++++++++
>  2 files changed, 15 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/vfio/mdev/mdev_core.c
> b/drivers/vfio/mdev/mdev_core.c
> index 5ca0efa5266bad..7ec21c907397a5 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -45,7 +45,7 @@ static struct mdev_parent *__find_parent_device(struct
> device *dev)
>  	return NULL;
>  }
> 
> -static void mdev_release_parent(struct kref *kref)
> +void mdev_release_parent(struct kref *kref)
>  {
>  	struct mdev_parent *parent = container_of(kref, struct mdev_parent,
>  						  ref);
> @@ -55,20 +55,6 @@ static void mdev_release_parent(struct kref *kref)
>  	put_device(dev);
>  }
> 
> -static struct mdev_parent *mdev_get_parent(struct mdev_parent *parent)
> -{
> -	if (parent)
> -		kref_get(&parent->ref);
> -
> -	return parent;
> -}
> -
> -static void mdev_put_parent(struct mdev_parent *parent)
> -{
> -	if (parent)
> -		kref_put(&parent->ref, mdev_release_parent);
> -}
> -
>  /* Caller must hold parent unreg_sem read or write lock */
>  static void mdev_device_remove_common(struct mdev_device *mdev)
>  {
> @@ -243,12 +229,9 @@ int mdev_device_create(struct mdev_type *type,
> const guid_t *uuid)
>  {
>  	int ret;
>  	struct mdev_device *mdev, *tmp;
> -	struct mdev_parent *parent;
> -
> -	parent = mdev_get_parent(type->parent);
> -	if (!parent)
> -		return -EINVAL;
> +	struct mdev_parent *parent = type->parent;
> 
> +	mdev_get_parent(parent);
>  	mutex_lock(&mdev_list_lock);
> 
>  	/* Check for duplicate */
> diff --git a/drivers/vfio/mdev/mdev_private.h
> b/drivers/vfio/mdev/mdev_private.h
> index debf27f95b4f10..10eccc35782c4d 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -46,4 +46,16 @@ void mdev_remove_sysfs_files(struct mdev_device
> *mdev);
>  int mdev_device_create(struct mdev_type *kobj, const guid_t *uuid);
>  int  mdev_device_remove(struct mdev_device *dev);
> 
> +void mdev_release_parent(struct kref *kref);
> +
> +static inline void mdev_get_parent(struct mdev_parent *parent)
> +{
> +	kref_get(&parent->ref);
> +}
> +
> +static inline void mdev_put_parent(struct mdev_parent *parent)
> +{
> +	kref_put(&parent->ref, mdev_release_parent);
> +}
> +
>  #endif /* MDEV_PRIVATE_H */
> --
> 2.31.0