i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj)
{
	if (obj->userptr.mm == NULL)
		return;

	kref_put_mutex(&obj->userptr.mm->kref,
		       __i915_mm_struct_free,
		       &to_i915(obj->base.dev)->mm_lock);
	obj->userptr.mm = NULL;
}
i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj)
{
	if (obj->userptr.mm == NULL)
		return;

	kref_put_mutex(&obj->userptr.mm->kref,
		       __i915_mm_struct_free,
		       &to_i915(obj->base.dev)->mm_lock);
	obj->userptr.mm = NULL;
}