+
+/**
+ * ttm_bo_wait_unreserved - interruptible wait for a buffer object to become
+ * unreserved
+ *
+ * @bo: Pointer to buffer
+ */
+int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo)
+{
+ int ret;
+
+ /*
+ * In the absense of a wait_unlocked API,
+ * Use the bo::wu_mutex to avoid triggering livelocks due to
+ * concurrent use of this function. Note that this use of
+ * bo::wu_mutex can go away if we change locking order to
+ * mmap_sem -> bo::reserve.
+ */
+ ret = mutex_lock_interruptible(&bo->wu_mutex);
+ if (unlikely(ret != 0))
+ return -ERESTARTSYS;
+ if (!ww_mutex_is_locked(&bo->resv->lock))
+ goto out_unlock;
+ ret = ttm_bo_reserve_nolru(bo, true, false, false, NULL);
+ if (unlikely(ret != 0))
+ goto out_unlock;
+ ww_mutex_unlock(&bo->resv->lock);
+
+out_unlock:
+ mutex_unlock(&bo->wu_mutex);
+ return ret;
+}