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, 16 insertions, 5 deletions

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1dc04b6684e..342bb0363fb 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -220,7 +220,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
         return ret;
 }
 
-static bool vring_restart(struct virtqueue *_vq)
+static void vring_disable_cb(struct virtqueue *_vq)
+{
+        struct vring_virtqueue *vq = to_vvq(_vq);
+
+        START_USE(vq);
+        BUG_ON(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT);
+        vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+        END_USE(vq);
+}
+
+static bool vring_enable_cb(struct virtqueue *_vq)
 {
         struct vring_virtqueue *vq = to_vvq(_vq);
 
@@ -254,8 +264,8 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
                 return IRQ_HANDLED;
 
         pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
-        if (vq->vq.callback && !vq->vq.callback(&vq->vq))
-                vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+        if (vq->vq.callback)
+                vq->vq.callback(&vq->vq);
 
         return IRQ_HANDLED;
 }
@@ -264,7 +274,8 @@ static struct virtqueue_ops vring_vq_ops = {
         .add_buf = vring_add_buf,
         .get_buf = vring_get_buf,
         .kick = vring_kick,
-        .restart = vring_restart,
+        .disable_cb = vring_disable_cb,
+        .enable_cb = vring_enable_cb,
         .shutdown = vring_shutdown,
 };
 
@@ -272,7 +283,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
                                       struct virtio_device *vdev,
                                       void *pages,
                                       void (*notify)(struct virtqueue *),
-                                      bool (*callback)(struct virtqueue *))
+                                      void (*callback)(struct virtqueue *))
 {
         struct vring_virtqueue *vq;
         unsigned int i;