Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[firefly-linux-kernel-4.4.55.git] / drivers / virtio / virtio_ring.c

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index fbd2ecde93e409ea9287d068d3f2322297c910cc..71929ee00d698b40f32d22b428e93b5f7dfcfbd4 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -334,6 +334,30 @@ static bool vring_enable_cb(struct virtqueue *_vq)
        return true;
 }
 
+static void *vring_detach_unused_buf(struct virtqueue *_vq)
+{
+       struct vring_virtqueue *vq = to_vvq(_vq);
+       unsigned int i;
+       void *buf;
+
+       START_USE(vq);
+
+       for (i = 0; i < vq->vring.num; i++) {
+               if (!vq->data[i])
+                       continue;
+               /* detach_buf clears data, so grab it now. */
+               buf = vq->data[i];
+               detach_buf(vq, i);
+               END_USE(vq);
+               return buf;
+       }
+       /* That should have freed everything. */
+       BUG_ON(vq->num_free != vq->vring.num);
+
+       END_USE(vq);
+       return NULL;
+}
+
 irqreturn_t vring_interrupt(int irq, void *_vq)
 {
        struct vring_virtqueue *vq = to_vvq(_vq);
@@ -360,6 +384,7 @@ static struct virtqueue_ops vring_vq_ops = {
        .kick = vring_kick,
        .disable_cb = vring_disable_cb,
        .enable_cb = vring_enable_cb,
+       .detach_unused_buf = vring_detach_unused_buf,
 };
 
 struct virtqueue *vring_new_virtqueue(unsigned int num,