net: sched: move and reuse mq_change_real_num_tx()

The code for handling active queue changes is identical
between mq and mqprio, reuse it.
Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sch_generic.h

@@ -1345,6 +1345,8 @@ void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
 				struct tcf_block *block);
 
+void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx);
+
 int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));
 
 #endif

net/sched/sch_generic.c

@@ -1339,6 +1339,30 @@ void dev_qdisc_change_real_num_tx(struct net_device *dev,
 		qdisc->ops->change_real_num_tx(qdisc, new_real_tx);
 }
 
+void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx)
+{
+#ifdef CONFIG_NET_SCHED
+	struct net_device *dev = qdisc_dev(sch);
+	struct Qdisc *qdisc;
+	unsigned int i;
+
+	for (i = new_real_tx; i < dev->real_num_tx_queues; i++) {
+		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
+		/* Only update the default qdiscs we created,
+		 * qdiscs with handles are always hashed.
+		 */
+		if (qdisc != &noop_qdisc && !qdisc->handle)
+			qdisc_hash_del(qdisc);
+	}
+	for (i = dev->real_num_tx_queues; i < new_real_tx; i++) {
+		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
+		if (qdisc != &noop_qdisc && !qdisc->handle)
+			qdisc_hash_add(qdisc, false);
+	}
+#endif
+}
+EXPORT_SYMBOL(mq_change_real_num_tx);
+
 int dev_qdisc_change_tx_queue_len(struct net_device *dev)
 {
 	bool up = dev->flags & IFF_UP;

net/sched/sch_mq.c

@@ -125,29 +125,6 @@ static void mq_attach(struct Qdisc *sch)
 	priv->qdiscs = NULL;
 }
 
-static void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx)
-{
-#ifdef CONFIG_NET_SCHED
-	struct net_device *dev = qdisc_dev(sch);
-	struct Qdisc *qdisc;
-	unsigned int i;
-
-	for (i = new_real_tx; i < dev->real_num_tx_queues; i++) {
-		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
-		/* Only update the default qdiscs we created,
-		 * qdiscs with handles are always hashed.
-		 */
-		if (qdisc != &noop_qdisc && !qdisc->handle)
-			qdisc_hash_del(qdisc);
-	}
-	for (i = dev->real_num_tx_queues; i < new_real_tx; i++) {
-		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
-		if (qdisc != &noop_qdisc && !qdisc->handle)
-			qdisc_hash_add(qdisc, false);
-	}
-#endif
-}
-
 static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct net_device *dev = qdisc_dev(sch);

net/sched/sch_mqprio.c

@@ -306,28 +306,6 @@ static void mqprio_attach(struct Qdisc *sch)
 	priv->qdiscs = NULL;
 }
 
-static void mqprio_change_real_num_tx(struct Qdisc *sch,
-				      unsigned int new_real_tx)
-{
-	struct net_device *dev = qdisc_dev(sch);
-	struct Qdisc *qdisc;
-	unsigned int i;
-
-	for (i = new_real_tx; i < dev->real_num_tx_queues; i++) {
-		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
-		/* Only update the default qdiscs we created,
-		 * qdiscs with handles are always hashed.
-		 */
-		if (qdisc != &noop_qdisc && !qdisc->handle)
-			qdisc_hash_del(qdisc);
-	}
-	for (i = dev->real_num_tx_queues; i < new_real_tx; i++) {
-		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
-		if (qdisc != &noop_qdisc && !qdisc->handle)
-			qdisc_hash_add(qdisc, false);
-	}
-}
-
 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
 					     unsigned long cl)
 {
@@ -645,7 +623,7 @@ static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
 	.init		= mqprio_init,
 	.destroy	= mqprio_destroy,
 	.attach		= mqprio_attach,
-	.change_real_num_tx = mqprio_change_real_num_tx,
+	.change_real_num_tx = mq_change_real_num_tx,
 	.dump		= mqprio_dump,
 	.owner		= THIS_MODULE,
 };