31 #include <trace/events/qdisc.h>
35 /* Qdisc to use by default */
39 static void qdisc_maybe_clear_missed(struct Qdisc *q,  in qdisc_maybe_clear_missed()
63  * qdisc_lock(qdisc) spinlock.
66  * - enqueue, dequeue are serialized via qdisc root lock
67  * - ingress filtering is also serialized via qdisc root lock
73 static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q)  in __skb_dequeue_bad_txq()
109 static inline struct sk_buff *qdisc_dequeue_skb_bad_txq(struct Qdisc *q)  in qdisc_dequeue_skb_bad_txq()
119 static inline void qdisc_enqueue_skb_bad_txq(struct Qdisc *q,  in qdisc_enqueue_skb_bad_txq()
143 static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)  in dev_requeue_skb()
179 static void try_bulk_dequeue_skb(struct Qdisc *q,  in try_bulk_dequeue_skb()
203 static void try_bulk_dequeue_skb_slow(struct Qdisc *q,  in try_bulk_dequeue_skb_slow()
229 static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate,  in dequeue_skb()
308  * required. Owning qdisc running bit guarantees that only one CPU
315 bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,  in sch_direct_xmit()
322 	/* And release qdisc */  in sch_direct_xmit()
374  * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
389 static inline bool qdisc_restart(struct Qdisc *q, int *packets)  in qdisc_restart()
411 void __qdisc_run(struct Qdisc *q)  in __qdisc_run()
634 static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,  in noop_enqueue()  argument
642 static struct sk_buff *noop_dequeue(struct Qdisc *qdisc)  in noop_dequeue()  argument
657 	RCU_POINTER_INITIALIZER(qdisc, &noop_qdisc),
661 struct Qdisc noop_qdisc = {
685 static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt,  in noqueue_init()  argument
691 	qdisc->enqueue = NULL;  in noqueue_init()
730 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,  in pfifo_fast_enqueue()  argument
734 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);  in pfifo_fast_enqueue()
742 		if (qdisc_is_percpu_stats(qdisc))  in pfifo_fast_enqueue()
743 			return qdisc_drop_cpu(skb, qdisc, to_free);  in pfifo_fast_enqueue()
745 			return qdisc_drop(skb, qdisc, to_free);  in pfifo_fast_enqueue()
748 	qdisc_update_stats_at_enqueue(qdisc, pkt_len);  in pfifo_fast_enqueue()
752 static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)  in pfifo_fast_dequeue()  argument
754 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);  in pfifo_fast_dequeue()
769 		qdisc_update_stats_at_dequeue(qdisc, skb);  in pfifo_fast_dequeue()
771 		   READ_ONCE(qdisc->state) & QDISC_STATE_NON_EMPTY) {  in pfifo_fast_dequeue()
777 		clear_bit(__QDISC_STATE_MISSED, &qdisc->state);  in pfifo_fast_dequeue()
778 		clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);  in pfifo_fast_dequeue()
793 static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)  in pfifo_fast_peek()  argument
795 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);  in pfifo_fast_peek()
808 static void pfifo_fast_reset(struct Qdisc *qdisc)  in pfifo_fast_reset()  argument
811 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);  in pfifo_fast_reset()
827 	if (qdisc_is_percpu_stats(qdisc)) {  in pfifo_fast_reset()
831 			q = per_cpu_ptr(qdisc->cpu_qstats, i);  in pfifo_fast_reset()
838 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)  in pfifo_fast_dump()  argument
851 static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,  in pfifo_fast_init()  argument
854 	unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len;  in pfifo_fast_init()
855 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);  in pfifo_fast_init()
872 	qdisc->flags |= TCQ_F_CAN_BYPASS;  in pfifo_fast_init()
876 static void pfifo_fast_destroy(struct Qdisc *sch)  in pfifo_fast_destroy()
896 static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,  in pfifo_fast_change_tx_queue_len()
931 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,  in qdisc_alloc()
935 	struct Qdisc *sch;  in qdisc_alloc()
975 	/* seqlock has the same scope of busylock, for NOLOCK qdisc */  in qdisc_alloc()
997 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,  in qdisc_create_dflt()
1002 	struct Qdisc *sch;  in qdisc_create_dflt()
1026 /* Under qdisc_lock(qdisc) and BH! */
1028 void qdisc_reset(struct Qdisc *qdisc)  in qdisc_reset()  argument
1030 	const struct Qdisc_ops *ops = qdisc->ops;  in qdisc_reset()
1032 	trace_qdisc_reset(qdisc);  in qdisc_reset()
1035 		ops->reset(qdisc);  in qdisc_reset()
1037 	__skb_queue_purge(&qdisc->gso_skb);  in qdisc_reset()
1038 	__skb_queue_purge(&qdisc->skb_bad_txq);  in qdisc_reset()
1040 	qdisc->q.qlen = 0;  in qdisc_reset()
1041 	qdisc->qstats.backlog = 0;  in qdisc_reset()
1045 void qdisc_free(struct Qdisc *qdisc)  in qdisc_free()  argument
1047 	if (qdisc_is_percpu_stats(qdisc)) {  in qdisc_free()
1048 		free_percpu(qdisc->cpu_bstats);  in qdisc_free()
1049 		free_percpu(qdisc->cpu_qstats);  in qdisc_free()
1052 	kfree(qdisc);  in qdisc_free()
1057 	struct Qdisc *q = container_of(head, struct Qdisc, rcu);  in qdisc_free_cb()
1062 static void __qdisc_destroy(struct Qdisc *qdisc)  in __qdisc_destroy()  argument
1064 	const struct Qdisc_ops  *ops = qdisc->ops;  in __qdisc_destroy()
1065 	struct net_device *dev = qdisc_dev(qdisc);  in __qdisc_destroy()
1068 	qdisc_hash_del(qdisc);  in __qdisc_destroy()
1070 	qdisc_put_stab(rtnl_dereference(qdisc->stab));  in __qdisc_destroy()
1072 	gen_kill_estimator(&qdisc->rate_est);  in __qdisc_destroy()
1074 	qdisc_reset(qdisc);  in __qdisc_destroy()
1078 		ops->destroy(qdisc);  in __qdisc_destroy()
1080 	lockdep_unregister_key(&qdisc->root_lock_key);  in __qdisc_destroy()
1082 	netdev_put(dev, &qdisc->dev_tracker);  in __qdisc_destroy()
1084 	trace_qdisc_destroy(qdisc);  in __qdisc_destroy()
1086 	call_rcu(&qdisc->rcu, qdisc_free_cb);  in __qdisc_destroy()
1089 void qdisc_destroy(struct Qdisc *qdisc)  in qdisc_destroy()  argument
1091 	if (qdisc->flags & TCQ_F_BUILTIN)  in qdisc_destroy()
1094 	__qdisc_destroy(qdisc);  in qdisc_destroy()
1097 void qdisc_put(struct Qdisc *qdisc)  in qdisc_put()  argument
1099 	if (!qdisc)  in qdisc_put()
1102 	if (qdisc->flags & TCQ_F_BUILTIN ||  in qdisc_put()
1103 	    !refcount_dec_and_test(&qdisc->refcnt))  in qdisc_put()
1106 	__qdisc_destroy(qdisc);  in qdisc_put()
1112  * qdisc reference counter reached zero.
1115 void qdisc_put_unlocked(struct Qdisc *qdisc)  in qdisc_put_unlocked()  argument
1117 	if (qdisc->flags & TCQ_F_BUILTIN ||  in qdisc_put_unlocked()
1118 	    !refcount_dec_and_rtnl_lock(&qdisc->refcnt))  in qdisc_put_unlocked()
1121 	__qdisc_destroy(qdisc);  in qdisc_put_unlocked()
1126 /* Attach toplevel qdisc to device queue. */
1127 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,  in dev_graft_qdisc()
1128 			      struct Qdisc *qdisc)  in dev_graft_qdisc()  argument
1130 	struct Qdisc *oqdisc = rtnl_dereference(dev_queue->qdisc_sleeping);  in dev_graft_qdisc()
1137 	if (qdisc == NULL)  in dev_graft_qdisc()
1138 		qdisc = &noop_qdisc;  in dev_graft_qdisc()
1139 	rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc);  in dev_graft_qdisc()
1140 	rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);  in dev_graft_qdisc()
1152 	struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);  in shutdown_scheduler_queue()  local
1153 	struct Qdisc *qdisc_default = _qdisc_default;  in shutdown_scheduler_queue()
1155 	if (qdisc) {  in shutdown_scheduler_queue()
1156 		rcu_assign_pointer(dev_queue->qdisc, qdisc_default);  in shutdown_scheduler_queue()
1159 		qdisc_put(qdisc);  in shutdown_scheduler_queue()
1167 	struct Qdisc *qdisc;  in attach_one_default_qdisc()  local
1175 	qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT, NULL);  in attach_one_default_qdisc()
1176 	if (!qdisc)  in attach_one_default_qdisc()
1180 		qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;  in attach_one_default_qdisc()
1181 	rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc);  in attach_one_default_qdisc()
1187 	struct Qdisc *qdisc;  in attach_default_qdiscs()  local
1194 		qdisc = rtnl_dereference(txq->qdisc_sleeping);  in attach_default_qdiscs()
1195 		rcu_assign_pointer(dev->qdisc, qdisc);  in attach_default_qdiscs()
1196 		qdisc_refcount_inc(qdisc);  in attach_default_qdiscs()
1198 		qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT, NULL);  in attach_default_qdiscs()
1199 		if (qdisc) {  in attach_default_qdiscs()
1200 			rcu_assign_pointer(dev->qdisc, qdisc);  in attach_default_qdiscs()
1201 			qdisc->ops->attach(qdisc);  in attach_default_qdiscs()
1204 	qdisc = rtnl_dereference(dev->qdisc);  in attach_default_qdiscs()
1206 	/* Detect default qdisc setup/init failed and fallback to "noqueue" */  in attach_default_qdiscs()
1207 	if (qdisc == &noop_qdisc) {  in attach_default_qdiscs()
1208 		netdev_warn(dev, "default qdisc (%s) fail, fallback to %s\n",  in attach_default_qdiscs()
1213 		qdisc = rtnl_dereference(txq->qdisc_sleeping);  in attach_default_qdiscs()
1214 		rcu_assign_pointer(dev->qdisc, qdisc);  in attach_default_qdiscs()
1215 		qdisc_refcount_inc(qdisc);  in attach_default_qdiscs()
1220 	if (qdisc != &noop_qdisc)  in attach_default_qdiscs()
1221 		qdisc_hash_add(qdisc, false);  in attach_default_qdiscs()
1229 	struct Qdisc *new_qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);  in transition_one_qdisc()
1235 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);  in transition_one_qdisc()
1251 	if (rtnl_dereference(dev->qdisc) == &noop_qdisc)  in dev_activate()
1270 static void qdisc_deactivate(struct Qdisc *qdisc)  in qdisc_deactivate()  argument
1272 	if (qdisc->flags & TCQ_F_BUILTIN)  in qdisc_deactivate()
1275 	set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);  in qdisc_deactivate()
1283 	struct Qdisc *qdisc;  in dev_deactivate_queue()  local
1285 	qdisc = rtnl_dereference(dev_queue->qdisc);  in dev_deactivate_queue()
1286 	if (qdisc) {  in dev_deactivate_queue()
1287 		if (qdisc->enqueue)  in dev_deactivate_queue()
1289 		qdisc_deactivate(qdisc);  in dev_deactivate_queue()
1290 		rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);  in dev_deactivate_queue()
1298 	struct Qdisc *qdisc;  in dev_reset_queue()  local
1301 	qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);  in dev_reset_queue()
1302 	if (!qdisc)  in dev_reset_queue()
1305 	nolock = qdisc->flags & TCQ_F_NOLOCK;  in dev_reset_queue()
1308 		spin_lock_bh(&qdisc->seqlock);  in dev_reset_queue()
1309 	spin_lock_bh(qdisc_lock(qdisc));  in dev_reset_queue()
1311 	qdisc_reset(qdisc);  in dev_reset_queue()
1313 	spin_unlock_bh(qdisc_lock(qdisc));  in dev_reset_queue()
1315 		clear_bit(__QDISC_STATE_MISSED, &qdisc->state);  in dev_reset_queue()
1316 		clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);  in dev_reset_queue()
1317 		spin_unlock_bh(&qdisc->seqlock);  in dev_reset_queue()
1328 		struct Qdisc *q;  in some_qdisc_is_busy()
1370 	/* Wait for outstanding qdisc enqueuing calls. */  in dev_deactivate_many()
1406 	struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);  in qdisc_change_tx_queue_len()  local
1407 	const struct Qdisc_ops *ops = qdisc->ops;  in qdisc_change_tx_queue_len()
1410 		return ops->change_tx_queue_len(qdisc, dev->tx_queue_len);  in qdisc_change_tx_queue_len()
1417 	struct Qdisc *qdisc = rtnl_dereference(dev->qdisc);  in dev_qdisc_change_real_num_tx()  local
1419 	if (qdisc->ops->change_real_num_tx)  in dev_qdisc_change_real_num_tx()
1420 		qdisc->ops->change_real_num_tx(qdisc, new_real_tx);  in dev_qdisc_change_real_num_tx()
1423 void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx)  in mq_change_real_num_tx()
1427 	struct Qdisc *qdisc;  in mq_change_real_num_tx()  local
1431 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc_sleeping);  in mq_change_real_num_tx()
1435 		if (qdisc != &noop_qdisc && !qdisc->handle)  in mq_change_real_num_tx()
1436 			qdisc_hash_del(qdisc);  in mq_change_real_num_tx()
1439 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc_sleeping);  in mq_change_real_num_tx()
1440 		if (qdisc != &noop_qdisc && !qdisc->handle)  in mq_change_real_num_tx()
1441 			qdisc_hash_add(qdisc, false);  in mq_change_real_num_tx()
1473 	struct Qdisc *qdisc = _qdisc;  in dev_init_scheduler_queue()  local
1475 	rcu_assign_pointer(dev_queue->qdisc, qdisc);  in dev_init_scheduler_queue()
1476 	rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc);  in dev_init_scheduler_queue()
1481 	rcu_assign_pointer(dev->qdisc, &noop_qdisc);  in dev_init_scheduler()
1494 	qdisc_put(rtnl_dereference(dev->qdisc));  in dev_shutdown()
1495 	rcu_assign_pointer(dev->qdisc, &noop_qdisc);  in dev_shutdown()
1609 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,  in mini_qdisc_pair_init()  argument
1612 	miniqp->miniq1.cpu_bstats = qdisc->cpu_bstats;  in mini_qdisc_pair_init()
1613 	miniqp->miniq1.cpu_qstats = qdisc->cpu_qstats;  in mini_qdisc_pair_init()
1614 	miniqp->miniq2.cpu_bstats = qdisc->cpu_bstats;  in mini_qdisc_pair_init()
1615 	miniqp->miniq2.cpu_qstats = qdisc->cpu_qstats;  in mini_qdisc_pair_init()