[PATCH net-next v4 13/15] virtio_net: xsk: tx: handle the transmitted xsk buffer

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

 virtnet_free_old_xmit distinguishes three type ptr(skb, xdp frame, xsk
 buffer) by the last bits of the pointer.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio_net.c | 60 ++++++++++++++++++++++++++++++++++------
 1 file changed, 52 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7f8ef93a194a..d38b4ef80f6f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -87,6 +87,7 @@ struct virtnet_stat_desc {
 struct virtnet_sq_free_stats {
 	u64 packets;
 	u64 bytes;
+	u64 xsk;
 };
 
 struct virtnet_sq_stats {
@@ -529,6 +530,7 @@ struct virtio_net_common_hdr {
 };
 
 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
+static void virtnet_xsk_completed(struct send_queue *sq, int num);
 
 enum virtnet_xmit_type {
 	VIRTNET_XMIT_TYPE_SKB,
@@ -730,6 +732,11 @@ static int virtnet_sq_set_premapped(struct send_queue *sq, bool premapped)
 	return 0;
 }
 
+static u32 virtnet_ptr_to_xsk(void *ptr)
+{
+	return ((unsigned long)ptr) >> VIRTIO_XSK_FLAG_OFFSET;
+}
+
 static void __free_old_xmit(struct send_queue *sq, bool in_napi,
 			    struct virtnet_sq_free_stats *stats)
 {
@@ -762,10 +769,24 @@ static void __free_old_xmit(struct send_queue *sq, bool in_napi,
 		case VIRTNET_XMIT_TYPE_DMA:
 			virtnet_sq_unmap(sq, &ptr);
 			goto retry;
+
+		case VIRTNET_XMIT_TYPE_XSK:
+			stats->bytes += virtnet_ptr_to_xsk(ptr);
+			stats->xsk++;
+			break;
 		}
 	}
 }
 
+static void virtnet_free_old_xmit(struct send_queue *sq, bool in_napi,
+				  struct virtnet_sq_free_stats *stats)
+{
+	__free_old_xmit(sq, in_napi, stats);
+
+	if (stats->xsk)
+		virtnet_xsk_completed(sq, stats->xsk);
+}
+
 /* Converting between virtqueue no. and kernel tx/rx queue no.
  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
  */
@@ -1194,7 +1215,7 @@ static void free_old_xmit(struct send_queue *sq, bool in_napi)
 {
 	struct virtnet_sq_free_stats stats = {0};
 
-	__free_old_xmit(sq, in_napi, &stats);
+	virtnet_free_old_xmit(sq, in_napi, &stats);
 
 	/* Avoid overhead when no packets have been processed
 	 * happens when called speculatively from start_xmit.
@@ -1335,8 +1356,12 @@ static bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool,
 	u64 kicks = 0;
 	int sent;
 
+	/* Avoid to wakeup napi meanless, so call __free_old_xmit. */
 	__free_old_xmit(sq, true, &stats);
 
+	if (stats.xsk)
+		xsk_tx_completed(sq->xsk.pool, stats.xsk);
+
 	sent = virtnet_xsk_xmit_batch(sq, pool, budget, &kicks);
 
 	if (!is_xdp_raw_buffer_queue(vi, sq - vi->sq))
@@ -1355,6 +1380,16 @@ static bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool,
 	return sent == budget;
 }
 
+static void xsk_wakeup(struct send_queue *sq)
+{
+	if (napi_if_scheduled_mark_missed(&sq->napi))
+		return;
+
+	local_bh_disable();
+	virtqueue_napi_schedule(&sq->napi, sq->vq);
+	local_bh_enable();
+}
+
 static int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
@@ -1368,14 +1403,19 @@ static int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag)
 
 	sq = &vi->sq[qid];
 
-	if (napi_if_scheduled_mark_missed(&sq->napi))
-		return 0;
+	xsk_wakeup(sq);
+	return 0;
+}
 
-	local_bh_disable();
-	virtqueue_napi_schedule(&sq->napi, sq->vq);
-	local_bh_enable();
+static void virtnet_xsk_completed(struct send_queue *sq, int num)
+{
+	xsk_tx_completed(sq->xsk.pool, num);
 
-	return 0;
+	/* If this is called by rx poll, start_xmit and xdp xmit we should
+	 * wakeup the tx napi to consume the xsk tx queue, because the tx
+	 * interrupt may not be triggered.
+	 */
+	xsk_wakeup(sq);
 }
 
 static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
@@ -1491,7 +1531,7 @@ static int virtnet_xdp_xmit(struct net_device *dev,
 	}
 
 	/* Free up any pending old buffers before queueing new ones. */
-	__free_old_xmit(sq, false, &stats);
+	virtnet_free_old_xmit(sq, false, &stats);
 
 	for (i = 0; i < n; i++) {
 		struct xdp_frame *xdpf = frames[i];
@@ -5839,6 +5879,10 @@ static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
 	case VIRTNET_XMIT_TYPE_DMA:
 		virtnet_sq_unmap(sq, &buf);
 		goto retry;
+
+	case VIRTNET_XMIT_TYPE_XSK:
+		xsk_tx_completed(sq->xsk.pool, 1);
+		break;
 	}
 }
 
-- 
2.32.0.3.g01195cf9f