1 files changed, 57 insertions, 0 deletions

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index cfbec3989a76..b0141973f23e 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -332,6 +332,63 @@ out:
 }
 EXPORT_SYMBOL(xsk_tx_peek_desc);
 
+static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, struct xdp_desc *descs,
+					u32 max_entries)
+{
+	u32 nb_pkts = 0;
+
+	while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
+		nb_pkts++;
+
+	xsk_tx_release(pool);
+	return nb_pkts;
+}
+
+u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, struct xdp_desc *descs,
+				   u32 max_entries)
+{
+	struct xdp_sock *xs;
+	u32 nb_pkts;
+
+	rcu_read_lock();
+	if (!list_is_singular(&pool->xsk_tx_list)) {
+		/* Fallback to the non-batched version */
+		rcu_read_unlock();
+		return xsk_tx_peek_release_fallback(pool, descs, max_entries);
+	}
+
+	xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
+	if (!xs) {
+		nb_pkts = 0;
+		goto out;
+	}
+
+	nb_pkts = xskq_cons_peek_desc_batch(xs->tx, descs, pool, max_entries);
+	if (!nb_pkts) {
+		xs->tx->queue_empty_descs++;
+		goto out;
+	}
+
+	/* This is the backpressure mechanism for the Tx path. Try to
+	 * reserve space in the completion queue for all packets, but
+	 * if there are fewer slots available, just process that many
+	 * packets. This avoids having to implement any buffering in
+	 * the Tx path.
+	 */
+	nb_pkts = xskq_prod_reserve_addr_batch(pool->cq, descs, nb_pkts);
+	if (!nb_pkts)
+		goto out;
+
+	xskq_cons_release_n(xs->tx, nb_pkts);
+	__xskq_cons_release(xs->tx);
+	xs->sk.sk_write_space(&xs->sk);
+
+out:
+	rcu_read_unlock();
+	return nb_pkts;
+}
+EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
+
 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
 {
 	struct net_device *dev = xs->dev;