[PATCH vhost 4/5] virtio_ring: virtqueue_set_dma_premapped() support to disable

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

virtio-net sq will only enable premapped mode when the sq is bound to
the af-xdp.

So we need the helper (virtqueue_set_dma_premapped) to enable the
premapped mode when af-xdp binds to the sq. And to disable the
premapped mode when af-xdp unbinds to the sq.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio_net.c     | 2 +-
 drivers/virtio/virtio_ring.c | 7 ++++---
 include/linux/virtio.h       | 2 +-
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3e8694837a29..a28a84101d5b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -795,7 +795,7 @@ static void virtnet_rq_set_premapped(struct virtnet_info *vi)
 
 	for (i = 0; i < vi->max_queue_pairs; i++)
 		/* error never happen */
-		BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq));
+		BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq, true));
 }
 
 static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index dab7f7fa8ec1..78145ad43370 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2712,8 +2712,9 @@ EXPORT_SYMBOL_GPL(virtqueue_resize);
 /**
  * virtqueue_set_dma_premapped - set the vring premapped mode
  * @_vq: the struct virtqueue we're talking about.
+ * @premapped: bool enable/disable the premapped mode
  *
- * Enable the premapped mode of the vq.
+ * Enable/disable the premapped mode of the vq.
  *
  * The vring in premapped mode does not do dma internally, so the driver must
  * do dma mapping in advance. The driver must pass the dma_address through
@@ -2730,7 +2731,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize);
  * 0: success.
  * -EINVAL: the vq is in use.
  */
-int virtqueue_set_dma_premapped(struct virtqueue *_vq)
+int virtqueue_set_dma_premapped(struct virtqueue *_vq, bool premapped)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);
 	u32 num;
@@ -2744,7 +2745,7 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
 		return -EINVAL;
 	}
 
-	vq->premapped = true;
+	vq->premapped = premapped;
 
 	END_USE(vq);
 
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 18694d201698..78687d9a8986 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -81,7 +81,7 @@ bool virtqueue_enable_cb(struct virtqueue *vq);
 
 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
 
-int virtqueue_set_dma_premapped(struct virtqueue *_vq);
+int virtqueue_set_dma_premapped(struct virtqueue *_vq, bool premapped);
 
 bool virtqueue_poll(struct virtqueue *vq, unsigned);
 
-- 
2.32.0.3.g01195cf9f