[PATCH 19/33] virtio_net: introduce virtnet_tx_reset()

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

Introduce virtnet_tx_reset() to release the buffers inside virtio ring.

This is needed for xsk disable. When disable xsk, we need to relese the
buffer from xsk, so this function is needed.

This patch reuse the virtnet_tx_resize.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio/main.c       | 21 ++++++++++++++++++---
 drivers/net/virtio/virtio_net.h |  1 +
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index fb82035a0b7f..049a3bb9d88d 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -1806,8 +1806,8 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 	return err;
 }
 
-static int virtnet_tx_resize(struct virtnet_info *vi,
-			     struct send_queue *sq, u32 ring_num)
+static int __virtnet_tx_reset(struct virtnet_info *vi,
+			      struct send_queue *sq, u32 ring_num)
 {
 	bool running = netif_running(vi->dev);
 	struct netdev_queue *txq;
@@ -1833,7 +1833,11 @@ static int virtnet_tx_resize(struct virtnet_info *vi,
 
 	__netif_tx_unlock_bh(txq);
 
-	err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
+	if (ring_num)
+		err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
+	else
+		err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf);
+
 	if (err)
 		netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
 
@@ -1847,6 +1851,17 @@ static int virtnet_tx_resize(struct virtnet_info *vi,
 	return err;
 }
 
+static int virtnet_tx_resize(struct virtnet_info *vi,
+			     struct send_queue *sq, u32 ring_num)
+{
+	return __virtnet_tx_reset(vi, sq, ring_num);
+}
+
+int virtnet_tx_reset(struct virtnet_info *vi, struct send_queue *sq)
+{
+	return __virtnet_tx_reset(vi, sq, 0);
+}
+
 /*
  * Send command via the control virtqueue and check status.  Commands
  * supported by the hypervisor, as indicated by feature bits, should
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index af3e7e817f9e..b46f083a630a 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -273,4 +273,5 @@ int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
 			struct net_device *dev,
 			unsigned int *xdp_xmit,
 			struct virtnet_rq_stats *stats);
+int virtnet_tx_reset(struct virtnet_info *vi, struct send_queue *sq);
 #endif
-- 
2.32.0.3.g01195cf9f