+int dma_buf_set_release_callback(struct dma_buf *dmabuf,
+ void (*callback)(void *), void *data)
+{
+ struct dma_buf_callback *cb;
+
+ if (WARN_ON(dma_buf_get_release_callback_data(dmabuf, callback)))
+ return -EINVAL;
+
+ cb = kzalloc(sizeof(*cb), GFP_KERNEL);
+ if (!cb)
+ return -ENOMEM;
+ cb->callback = callback;
+ cb->data = data;
+ list_add_tail(&cb->list, &dmabuf->release_callbacks);
+
+ return 0;
+}
+
+void *dma_buf_get_release_callback_data(struct dma_buf *dmabuf,
+ void (*callback)(void *))
+{
+ struct dma_buf_callback *cb, *tmp;
+
+ list_for_each_entry_safe(cb, tmp, &dmabuf->release_callbacks, list) {
+ if (cb->callback == callback)
+ return cb->data;
+ }
+
+ return NULL;
+}
+