1 files changed, 73 insertions, 0 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 4ac77456e830..158aeb1b6a8a 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -1348,6 +1348,79 @@ void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
 }
 EXPORT_SYMBOL(dma_async_tx_descriptor_init);
 
+static inline int desc_check_and_set_metadata_mode(
+	struct dma_async_tx_descriptor *desc, enum dma_desc_metadata_mode mode)
+{
+	/* Make sure that the metadata mode is not mixed */
+	if (!desc->desc_metadata_mode) {
+		if (dmaengine_is_metadata_mode_supported(desc->chan, mode))
+			desc->desc_metadata_mode = mode;
+		else
+			return -ENOTSUPP;
+	} else if (desc->desc_metadata_mode != mode) {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int dmaengine_desc_attach_metadata(struct dma_async_tx_descriptor *desc,
+				   void *data, size_t len)
+{
+	int ret;
+
+	if (!desc)
+		return -EINVAL;
+
+	ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_CLIENT);
+	if (ret)
+		return ret;
+
+	if (!desc->metadata_ops || !desc->metadata_ops->attach)
+		return -ENOTSUPP;
+
+	return desc->metadata_ops->attach(desc, data, len);
+}
+EXPORT_SYMBOL_GPL(dmaengine_desc_attach_metadata);
+
+void *dmaengine_desc_get_metadata_ptr(struct dma_async_tx_descriptor *desc,
+				      size_t *payload_len, size_t *max_len)
+{
+	int ret;
+
+	if (!desc)
+		return ERR_PTR(-EINVAL);
+
+	ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (!desc->metadata_ops || !desc->metadata_ops->get_ptr)
+		return ERR_PTR(-ENOTSUPP);
+
+	return desc->metadata_ops->get_ptr(desc, payload_len, max_len);
+}
+EXPORT_SYMBOL_GPL(dmaengine_desc_get_metadata_ptr);
+
+int dmaengine_desc_set_metadata_len(struct dma_async_tx_descriptor *desc,
+				    size_t payload_len)
+{
+	int ret;
+
+	if (!desc)
+		return -EINVAL;
+
+	ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE);
+	if (ret)
+		return ret;
+
+	if (!desc->metadata_ops || !desc->metadata_ops->set_len)
+		return -ENOTSUPP;
+
+	return desc->metadata_ops->set_len(desc, payload_len);
+}
+EXPORT_SYMBOL_GPL(dmaengine_desc_set_metadata_len);
+
 /* dma_wait_for_async_tx - spin wait for a transaction to complete
  * @tx: in-flight transaction to wait on
  */