virtio: explicit enable_cb/disable_cb rather than callback return.

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 6 insertions, 5 deletions

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 14e1379876d3..951d81747b42 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -11,15 +11,13 @@
 /**
  * virtqueue - a queue to register buffers for sending or receiving.
  * @callback: the function to call when buffers are consumed (can be NULL).
- *    If this returns false, callbacks are suppressed until vq_ops->restart
- *    is called.
  * @vdev: the virtio device this queue was created for.
  * @vq_ops: the operations for this virtqueue (see below).
  * @priv: a pointer for the virtqueue implementation to use.
  */
 struct virtqueue
 {
-        bool (*callback)(struct virtqueue *vq);
+        void (*callback)(struct virtqueue *vq);
         struct virtio_device *vdev;
         struct virtqueue_ops *vq_ops;
         void *priv;
@@ -41,7 +39,9 @@ struct virtqueue
  *      vq: the struct virtqueue we're talking about.
  *      len: the length written into the buffer
  *      Returns NULL or the "data" token handed to add_buf.
- * @restart: restart callbacks after callback returned false.
+ * @disable_cb: disable callbacks
+ *      vq: the struct virtqueue we're talking about.
+ * @enable_cb: restart callbacks after disable_cb.
  *      vq: the struct virtqueue we're talking about.
  *      This returns "false" (and doesn't re-enable) if there are pending
  *      buffers in the queue, to avoid a race.
@@ -65,7 +65,8 @@ struct virtqueue_ops {
 
         void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
 
-        bool (*restart)(struct virtqueue *vq);
+        void (*disable_cb)(struct virtqueue *vq);
+        bool (*enable_cb)(struct virtqueue *vq);
 
         void (*shutdown)(struct virtqueue *vq);
 };