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>

3 files changed, 8 insertions, 7 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);
 };
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 70bb26062d76..81f828ac8f47 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -61,7 +61,7 @@ struct virtio_config_ops
 	void (*set_status)(struct virtio_device *vdev, u8 status);
 	struct virtqueue *(*find_vq)(struct virtio_device *vdev,
 				     unsigned index,
-				     bool (*callback)(struct virtqueue *));
+				     void (*callback)(struct virtqueue *));
 	void (*del_vq)(struct virtqueue *vq);
 };
 
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 1a4ed49f6478..8cde10e792c4 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -114,7 +114,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
 				      struct virtio_device *vdev,
 				      void *pages,
 				      void (*notify)(struct virtqueue *vq),
-				      bool (*callback)(struct virtqueue *vq));
+				      void (*callback)(struct virtqueue *vq));
 void vring_del_virtqueue(struct virtqueue *vq);
 
 irqreturn_t vring_interrupt(int irq, void *_vq);