1 files changed, 33 insertions, 1 deletions

diff --git a/src/net/netdevice.c b/src/net/netdevice.c
index 3b02e64bd..6e685630c 100644
--- a/src/net/netdevice.c
+++ b/src/net/netdevice.c
@@ -307,6 +307,12 @@ int netdev_tx ( struct net_device *netdev, struct io_buffer *iobuf ) {
 	if ( ( rc = inject_fault ( NETDEV_DISCARD_RATE ) ) != 0 )
 		goto err;
 
+	/* Map for DMA, if required */
+	if ( netdev->dma && ( ! dma_mapped ( &iobuf->map ) ) ) {
+		if ( ( rc = iob_map_tx ( iobuf, netdev->dma ) ) != 0 )
+			goto err;
+	}
+
 	/* Transmit packet */
 	if ( ( rc = netdev->op->transmit ( netdev, iobuf ) ) != 0 )
 		goto err;
@@ -340,6 +346,9 @@ int netdev_tx ( struct net_device *netdev, struct io_buffer *iobuf ) {
  * Failure to do this will cause the retransmitted packet to be
  * immediately redeferred (which will result in out-of-order
  * transmissions and other nastiness).
+ *
+ * I/O buffers that have been mapped for DMA will remain mapped while
+ * present in the deferred transmit queue.
  */
 void netdev_tx_defer ( struct net_device *netdev, struct io_buffer *iobuf ) {
 
@@ -365,6 +374,9 @@ void netdev_tx_defer ( struct net_device *netdev, struct io_buffer *iobuf ) {
  *
  * The packet is discarded and a TX error is recorded.  This function
  * takes ownership of the I/O buffer.
+ *
+ * The I/O buffer will be automatically unmapped for DMA, if
+ * applicable.
  */
 void netdev_tx_err ( struct net_device *netdev,
 		     struct io_buffer *iobuf, int rc ) {
@@ -379,6 +391,10 @@ void netdev_tx_err ( struct net_device *netdev,
 		       netdev->name, iobuf, strerror ( rc ) );
 	}
 
+	/* Unmap I/O buffer, if required */
+	if ( iobuf && dma_mapped ( &iobuf->map ) )
+		iob_unmap ( iobuf );
+
 	/* Discard packet */
 	free_iob ( iobuf );
 }
@@ -462,10 +478,13 @@ static void netdev_tx_flush ( struct net_device *netdev ) {
  * Add packet to receive queue
  *
  * @v netdev		Network device
- * @v iobuf		I/O buffer, or NULL
+ * @v iobuf		I/O buffer
  *
  * The packet is added to the network device's RX queue.  This
  * function takes ownership of the I/O buffer.
+ *
+ * The I/O buffer will be automatically unmapped for DMA, if
+ * applicable.
  */
 void netdev_rx ( struct net_device *netdev, struct io_buffer *iobuf ) {
 	int rc;
@@ -479,6 +498,10 @@ void netdev_rx ( struct net_device *netdev, struct io_buffer *iobuf ) {
 		return;
 	}
 
+	/* Unmap I/O buffer, if required */
+	if ( dma_mapped ( &iobuf->map ) )
+		iob_unmap ( iobuf );
+
 	/* Enqueue packet */
 	list_add_tail ( &iobuf->list, &netdev->rx_queue );
 
@@ -497,6 +520,9 @@ void netdev_rx ( struct net_device *netdev, struct io_buffer *iobuf ) {
  * takes ownership of the I/O buffer.  @c iobuf may be NULL if, for
  * example, the net device wishes to report an error due to being
  * unable to allocate an I/O buffer.
+ *
+ * The I/O buffer will be automatically unmapped for DMA, if
+ * applicable.
  */
 void netdev_rx_err ( struct net_device *netdev,
 		     struct io_buffer *iobuf, int rc ) {
@@ -504,6 +530,10 @@ void netdev_rx_err ( struct net_device *netdev,
 	DBGC ( netdev, "NETDEV %s failed to receive %p: %s\n",
 	       netdev->name, iobuf, strerror ( rc ) );
 
+	/* Unmap I/O buffer, if required */
+	if ( iobuf && dma_mapped ( &iobuf->map ) )
+		iob_unmap ( iobuf );
+
 	/* Discard packet */
 	free_iob ( iobuf );
 
@@ -1178,6 +1208,8 @@ static unsigned int net_discard ( void ) {
 
 			/* Discard first deferred packet */
 			list_del ( &iobuf->list );
+			if ( dma_mapped ( &iobuf->map ) )
+				iob_unmap ( iobuf );
 			free_iob ( iobuf );
 
 			/* Report discard */