+/**
+ * drm_new_set_master - Allocate a new master object and become master for the
+ * associated master realm.
+ *
+ * @dev: The associated device.
+ * @fpriv: File private identifying the client.
+ *
+ * This function must be called with dev::struct_mutex held.
+ * Returns negative error code on failure. Zero on success.
+ */
+int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
+{
+ struct drm_master *old_master;
+ int ret;
+
+ lockdep_assert_held_once(&dev->master_mutex);
+
+ /* create a new master */
+ fpriv->minor->master = drm_master_create(fpriv->minor);
+ if (!fpriv->minor->master)
+ return -ENOMEM;
+
+ /* take another reference for the copy in the local file priv */
+ old_master = fpriv->master;
+ fpriv->master = drm_master_get(fpriv->minor->master);
+
+ if (dev->driver->master_create) {
+ ret = dev->driver->master_create(dev, fpriv->master);
+ if (ret)
+ goto out_err;
+ }
+ if (dev->driver->master_set) {
+ ret = dev->driver->master_set(dev, fpriv, true);
+ if (ret)
+ goto out_err;
+ }
+
+ fpriv->is_master = 1;
+ fpriv->allowed_master = 1;
+ fpriv->authenticated = 1;
+ if (old_master)
+ drm_master_put(&old_master);
+
+ return 0;
+
+out_err:
+ /* drop both references and restore old master on failure */
+ drm_master_put(&fpriv->minor->master);
+ drm_master_put(&fpriv->master);
+ fpriv->master = old_master;
+
+ return ret;
+}
+