virtio: Add transport feature handling stub for virtio_ring.

[linux-2.6-omap-h63xx.git] / drivers / virtio / virtio_ring.c

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 72bf8bc090142f02a9065c0ff0448299a5e9a2e7..6eb5303fed11b20613083ed960aa27cb8e2d4bd9 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -18,6 +18,7 @@
  */
 #include <linux/virtio.h>
 #include <linux/virtio_ring.h>
+#include <linux/virtio_config.h>
 #include <linux/device.h>
 
 #ifdef DEBUG
@@ -87,8 +88,11 @@ static int vring_add_buf(struct virtqueue *_vq,
        if (vq->num_free < out + in) {
                pr_debug("Can't add buf len %i - avail = %i\n",
                         out + in, vq->num_free);
-               /* We notify *even if* VRING_USED_F_NO_NOTIFY is set here. */
-               vq->notify(&vq->vq);
+               /* FIXME: for historical reasons, we force a notify here if
+                * there are outgoing parts to the buffer.  Presumably the
+                * host should service the ring ASAP. */
+               if (out)
+                       vq->notify(&vq->vq);
                END_USE(vq);
                return -ENOSPC;
        }
@@ -320,4 +324,19 @@ void vring_del_virtqueue(struct virtqueue *vq)
 }
 EXPORT_SYMBOL_GPL(vring_del_virtqueue);
 
+/* Manipulates transport-specific feature bits. */
+void vring_transport_features(struct virtio_device *vdev)
+{
+       unsigned int i;
+
+       for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
+               switch (i) {
+               default:
+                       /* We don't understand this bit. */
+                       clear_bit(i, vdev->features);
+               }
+       }
+}
+EXPORT_SYMBOL_GPL(vring_transport_features);
+
 MODULE_LICENSE("GPL");