1 files changed, 925 insertions, 327 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 57ba406f1437..852e603c1755 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/sched/sch_generic.c	Generic packet scheduler routines.
  *
- *		This program is free software; you can redistribute it and/or
- *		modify it under the terms of the GNU General Public License
- *		as published by the Free Software Foundation; either version
- *		2 of the License, or (at your option) any later version.
- *
  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  *              Jamal Hadi Salim, <hadi@cyberus.ca> 990601
  *              - Ingress support
@@ -26,14 +22,42 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/if_vlan.h>
+#include <linux/skb_array.h>
+#include <linux/if_macvlan.h>
+#include <linux/bpf.h>
 #include <net/sch_generic.h>
 #include <net/pkt_sched.h>
 #include <net/dst.h>
+#include <net/hotdata.h>
+#include <trace/events/qdisc.h>
+#include <trace/events/net.h>
+#include <net/xfrm.h>
 
 /* Qdisc to use by default */
 const struct Qdisc_ops *default_qdisc_ops = &pfifo_fast_ops;
 EXPORT_SYMBOL(default_qdisc_ops);
 
+static void qdisc_maybe_clear_missed(struct Qdisc *q,
+				     const struct netdev_queue *txq)
+{
+	clear_bit(__QDISC_STATE_MISSED, &q->state);
+
+	/* Make sure the below netif_xmit_frozen_or_stopped()
+	 * checking happens after clearing STATE_MISSED.
+	 */
+	smp_mb__after_atomic();
+
+	/* Checking netif_xmit_frozen_or_stopped() again to
+	 * make sure STATE_MISSED is set if the STATE_MISSED
+	 * set by netif_tx_wake_queue()'s rescheduling of
+	 * net_tx_action() is cleared by the above clear_bit().
+	 */
+	if (!netif_xmit_frozen_or_stopped(txq))
+		set_bit(__QDISC_STATE_MISSED, &q->state);
+	else
+		set_bit(__QDISC_STATE_DRAINING, &q->state);
+}
+
 /* Main transmission queue. */
 
 /* Modifications to data participating in scheduling must be protected with
@@ -45,23 +69,121 @@ EXPORT_SYMBOL(default_qdisc_ops);
  * - updates to tree and tree walking are only done under the rtnl mutex.
  */
 
-static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
+#define SKB_XOFF_MAGIC ((struct sk_buff *)1UL)
+
+static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q)
 {
-	q->gso_skb = skb;
-	q->qstats.requeues++;
-	qdisc_qstats_backlog_inc(q, skb);
-	q->q.qlen++;	/* it's still part of the queue */
-	__netif_schedule(q);
+	const struct netdev_queue *txq = q->dev_queue;
+	spinlock_t *lock = NULL;
+	struct sk_buff *skb;
 
-	return 0;
+	if (q->flags & TCQ_F_NOLOCK) {
+		lock = qdisc_lock(q);
+		spin_lock(lock);
+	}
+
+	skb = skb_peek(&q->skb_bad_txq);
+	if (skb) {
+		/* check the reason of requeuing without tx lock first */
+		txq = skb_get_tx_queue(txq->dev, skb);
+		if (!netif_xmit_frozen_or_stopped(txq)) {
+			skb = __skb_dequeue(&q->skb_bad_txq);
+			if (qdisc_is_percpu_stats(q)) {
+				qdisc_qstats_cpu_backlog_dec(q, skb);
+				qdisc_qstats_cpu_qlen_dec(q);
+			} else {
+				qdisc_qstats_backlog_dec(q, skb);
+				q->q.qlen--;
+			}
+		} else {
+			skb = SKB_XOFF_MAGIC;
+			qdisc_maybe_clear_missed(q, txq);
+		}
+	}
+
+	if (lock)
+		spin_unlock(lock);
+
+	return skb;
+}
+
+static inline struct sk_buff *qdisc_dequeue_skb_bad_txq(struct Qdisc *q)
+{
+	struct sk_buff *skb = skb_peek(&q->skb_bad_txq);
+
+	if (unlikely(skb))
+		skb = __skb_dequeue_bad_txq(q);
+
+	return skb;
+}
+
+static inline void qdisc_enqueue_skb_bad_txq(struct Qdisc *q,
+					     struct sk_buff *skb)
+{
+	spinlock_t *lock = NULL;
+
+	if (q->flags & TCQ_F_NOLOCK) {
+		lock = qdisc_lock(q);
+		spin_lock(lock);
+	}
+
+	__skb_queue_tail(&q->skb_bad_txq, skb);
+
+	if (qdisc_is_percpu_stats(q)) {
+		qdisc_qstats_cpu_backlog_inc(q, skb);
+		qdisc_qstats_cpu_qlen_inc(q);
+	} else {
+		qdisc_qstats_backlog_inc(q, skb);
+		q->q.qlen++;
+	}
+
+	if (lock)
+		spin_unlock(lock);
+}
+
+static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
+{
+	spinlock_t *lock = NULL;
+
+	if (q->flags & TCQ_F_NOLOCK) {
+		lock = qdisc_lock(q);
+		spin_lock(lock);
+	}
+
+	while (skb) {
+		struct sk_buff *next = skb->next;
+
+		__skb_queue_tail(&q->gso_skb, skb);
+
+		/* it's still part of the queue */
+		if (qdisc_is_percpu_stats(q)) {
+			qdisc_qstats_cpu_requeues_inc(q);
+			qdisc_qstats_cpu_backlog_inc(q, skb);
+			qdisc_qstats_cpu_qlen_inc(q);
+		} else {
+			q->qstats.requeues++;
+			qdisc_qstats_backlog_inc(q, skb);
+			q->q.qlen++;
+		}
+
+		skb = next;
+	}
+
+	if (lock) {
+		spin_unlock(lock);
+		set_bit(__QDISC_STATE_MISSED, &q->state);
+	} else {
+		__netif_schedule(q);
+	}
 }
 
 static void try_bulk_dequeue_skb(struct Qdisc *q,
 				 struct sk_buff *skb,
 				 const struct netdev_queue *txq,
-				 int *packets)
+				 int *packets, int budget)
 {
 	int bytelimit = qdisc_avail_bulklimit(txq) - skb->len;
+	int cnt = 0;
 
 	while (bytelimit > 0) {
 		struct sk_buff *nskb = q->dequeue(q);
@@ -72,9 +194,11 @@ static void try_bulk_dequeue_skb(struct Qdisc *q,
 		bytelimit -= nskb->len; /* covers GSO len */
 		skb->next = nskb;
 		skb = nskb;
-		(*packets)++; /* GSO counts as one pkt */
+		if (++cnt >= budget)
+			break;
 	}
-	skb->next = NULL;
+	(*packets) += cnt;
+	skb_mark_not_on_list(skb);
 }
 
 /* This variant of try_bulk_dequeue_skb() makes sure
@@ -93,117 +217,158 @@ static void try_bulk_dequeue_skb_slow(struct Qdisc *q,
 		if (!nskb)
 			break;
 		if (unlikely(skb_get_queue_mapping(nskb) != mapping)) {
-			q->skb_bad_txq = nskb;
-			qdisc_qstats_backlog_inc(q, nskb);
-			q->q.qlen++;
+			qdisc_enqueue_skb_bad_txq(q, nskb);
 			break;
 		}
 		skb->next = nskb;
 		skb = nskb;
 	} while (++cnt < 8);
 	(*packets) += cnt;
-	skb->next = NULL;
+	skb_mark_not_on_list(skb);
 }
 
 /* Note that dequeue_skb can possibly return a SKB list (via skb->next).
  * A requeued skb (via q->gso_skb) can also be a SKB list.
  */
 static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate,
-				   int *packets)
+				   int *packets, int budget)
 {
-	struct sk_buff *skb = q->gso_skb;
 	const struct netdev_queue *txq = q->dev_queue;
+	struct sk_buff *skb = NULL;
 
 	*packets = 1;
-	if (unlikely(skb)) {
+	if (unlikely(!skb_queue_empty(&q->gso_skb))) {
+		spinlock_t *lock = NULL;
+
+		if (q->flags & TCQ_F_NOLOCK) {
+			lock = qdisc_lock(q);
+			spin_lock(lock);
+		}
+
+		skb = skb_peek(&q->gso_skb);
+
+		/* skb may be null if another cpu pulls gso_skb off in between
+		 * empty check and lock.
+		 */
+		if (!skb) {
+			if (lock)
+				spin_unlock(lock);
+			goto validate;
+		}
+
 		/* skb in gso_skb were already validated */
 		*validate = false;
+		if (xfrm_offload(skb))
+			*validate = true;
 		/* check the reason of requeuing without tx lock first */
 		txq = skb_get_tx_queue(txq->dev, skb);
 		if (!netif_xmit_frozen_or_stopped(txq)) {
-			q->gso_skb = NULL;
-			qdisc_qstats_backlog_dec(q, skb);
-			q->q.qlen--;
-		} else
+			skb = __skb_dequeue(&q->gso_skb);
+			if (qdisc_is_percpu_stats(q)) {
+				qdisc_qstats_cpu_backlog_dec(q, skb);
+				qdisc_qstats_cpu_qlen_dec(q);
+			} else {
+				qdisc_qstats_backlog_dec(q, skb);
+				q->q.qlen--;
+			}
+		} else {
 			skb = NULL;
-		return skb;
+			qdisc_maybe_clear_missed(q, txq);
+		}
+		if (lock)
+			spin_unlock(lock);
+		goto trace;
 	}
+validate:
 	*validate = true;
-	skb = q->skb_bad_txq;
+
+	if ((q->flags & TCQ_F_ONETXQUEUE) &&
+	    netif_xmit_frozen_or_stopped(txq)) {
+		qdisc_maybe_clear_missed(q, txq);
+		return skb;
+	}
+
+	skb = qdisc_dequeue_skb_bad_txq(q);
 	if (unlikely(skb)) {
-		/* check the reason of requeuing without tx lock first */
-		txq = skb_get_tx_queue(txq->dev, skb);
-		if (!netif_xmit_frozen_or_stopped(txq)) {
-			q->skb_bad_txq = NULL;
-			qdisc_qstats_backlog_dec(q, skb);
-			q->q.qlen--;
-			goto bulk;
-		}
-		return NULL;
+		if (skb == SKB_XOFF_MAGIC)
+			return NULL;
+		goto bulk;
 	}
-	if (!(q->flags & TCQ_F_ONETXQUEUE) ||
-	    !netif_xmit_frozen_or_stopped(txq))
-		skb = q->dequeue(q);
+	skb = q->dequeue(q);
 	if (skb) {
 bulk:
 		if (qdisc_may_bulk(q))
-			try_bulk_dequeue_skb(q, skb, txq, packets);
+			try_bulk_dequeue_skb(q, skb, txq, packets, budget);
 		else
 			try_bulk_dequeue_skb_slow(q, skb, packets);
 	}
+trace:
+	trace_qdisc_dequeue(q, txq, *packets, skb);
 	return skb;
 }
 
 /*
  * Transmit possibly several skbs, and handle the return status as
- * required. Owning running seqcount bit guarantees that
- * only one CPU can execute this function.
+ * required. Owning qdisc running bit guarantees that only one CPU
+ * can execute this function.
  *
  * Returns to the caller:
- *				0  - queue is empty or throttled.
- *				>0 - queue is not empty.
+ *				false  - hardware queue frozen backoff
+ *				true   - feel free to send more pkts
  */
-int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
-		    struct net_device *dev, struct netdev_queue *txq,
-		    spinlock_t *root_lock, bool validate)
+bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
+		     struct net_device *dev, struct netdev_queue *txq,
+		     spinlock_t *root_lock, bool validate)
 {
 	int ret = NETDEV_TX_BUSY;
+	bool again = false;
 
 	/* And release qdisc */
-	spin_unlock(root_lock);
+	if (root_lock)
+		spin_unlock(root_lock);
 
 	/* Note that we validate skb (GSO, checksum, ...) outside of locks */
 	if (validate)
-		skb = validate_xmit_skb_list(skb, dev);
+		skb = validate_xmit_skb_list(skb, dev, &again);
+
+#ifdef CONFIG_XFRM_OFFLOAD
+	if (unlikely(again)) {
+		if (root_lock)
+			spin_lock(root_lock);
+
+		dev_requeue_skb(skb, q);
+		return false;
+	}
+#endif
 
 	if (likely(skb)) {
 		HARD_TX_LOCK(dev, txq, smp_processor_id());
 		if (!netif_xmit_frozen_or_stopped(txq))
 			skb = dev_hard_start_xmit(skb, dev, txq, &ret);
+		else
+			qdisc_maybe_clear_missed(q, txq);
 
 		HARD_TX_UNLOCK(dev, txq);
 	} else {
-		spin_lock(root_lock);
-		return qdisc_qlen(q);
+		if (root_lock)
+			spin_lock(root_lock);
+		return true;
 	}
-	spin_lock(root_lock);
 
-	if (dev_xmit_complete(ret)) {
-		/* Driver sent out skb successfully or skb was consumed */
-		ret = qdisc_qlen(q);
-	} else {
+	if (root_lock)
+		spin_lock(root_lock);
+
+	if (!dev_xmit_complete(ret)) {
 		/* Driver returned NETDEV_TX_BUSY - requeue skb */
 		if (unlikely(ret != NETDEV_TX_BUSY))
 			net_warn_ratelimited("BUG %s code %d qlen %d\n",
 					     dev->name, ret, q->q.qlen);
 
-		ret = dev_requeue_skb(skb, q);
+		dev_requeue_skb(skb, q);
+		return false;
 	}
 
-	if (ret && netif_xmit_frozen_or_stopped(txq))
-		ret = 0;
-
-	return ret;
+	return true;
 }
 
 /*
@@ -225,20 +390,22 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
  *				>0 - queue is not empty.
  *
  */
-static inline int qdisc_restart(struct Qdisc *q, int *packets)
+static inline bool qdisc_restart(struct Qdisc *q, int *packets, int budget)
 {
+	spinlock_t *root_lock = NULL;
 	struct netdev_queue *txq;
 	struct net_device *dev;
-	spinlock_t *root_lock;
 	struct sk_buff *skb;
 	bool validate;
 
 	/* Dequeue packet */
-	skb = dequeue_skb(q, &validate, packets);
+	skb = dequeue_skb(q, &validate, packets, budget);
 	if (unlikely(!skb))
-		return 0;
+		return false;
+
+	if (!(q->flags & TCQ_F_NOLOCK))
+		root_lock = qdisc_lock(q);
 
-	root_lock = qdisc_lock(q);
 	dev = qdisc_dev(q);
 	txq = skb_get_tx_queue(dev, skb);
 
@@ -247,35 +414,30 @@ static inline int qdisc_restart(struct Qdisc *q, int *packets)
 
 void __qdisc_run(struct Qdisc *q)
 {
-	int quota = dev_tx_weight;
+	int quota = READ_ONCE(net_hotdata.dev_tx_weight);
 	int packets;
 
-	while (qdisc_restart(q, &packets)) {
-		/*
-		 * Ordered by possible occurrence: Postpone processing if
-		 * 1. we've exceeded packet quota
-		 * 2. another process needs the CPU;
-		 */
+	while (qdisc_restart(q, &packets, quota)) {
 		quota -= packets;
-		if (quota <= 0 || need_resched()) {
-			__netif_schedule(q);
+		if (quota <= 0) {
+			if (q->flags & TCQ_F_NOLOCK)
+				set_bit(__QDISC_STATE_MISSED, &q->state);
+			else
+				__netif_schedule(q);
+
 			break;
 		}
 	}
-
-	qdisc_run_end(q);
 }
 
 unsigned long dev_trans_start(struct net_device *dev)
 {
-	unsigned long val, res;
+	unsigned long res = READ_ONCE(netdev_get_tx_queue(dev, 0)->trans_start);
+	unsigned long val;
 	unsigned int i;
 
-	if (is_vlan_dev(dev))
-		dev = vlan_dev_real_dev(dev);
-	res = netdev_get_tx_queue(dev, 0)->trans_start;
 	for (i = 1; i < dev->num_tx_queues; i++) {
-		val = netdev_get_tx_queue(dev, i)->trans_start;
+		val = READ_ONCE(netdev_get_tx_queue(dev, i)->trans_start);
 		if (val && time_after(val, res))
 			res = val;
 	}
@@ -284,70 +446,133 @@ unsigned long dev_trans_start(struct net_device *dev)
 }
 EXPORT_SYMBOL(dev_trans_start);
 
-static void dev_watchdog(unsigned long arg)
+static void netif_freeze_queues(struct net_device *dev)
+{
+	unsigned int i;
+	int cpu;
+
+	cpu = smp_processor_id();
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+		/* We are the only thread of execution doing a
+		 * freeze, but we have to grab the _xmit_lock in
+		 * order to synchronize with threads which are in
+		 * the ->hard_start_xmit() handler and already
+		 * checked the frozen bit.
+		 */
+		__netif_tx_lock(txq, cpu);
+		set_bit(__QUEUE_STATE_FROZEN, &txq->state);
+		__netif_tx_unlock(txq);
+	}
+}
+
+void netif_tx_lock(struct net_device *dev)
+{
+	spin_lock(&dev->tx_global_lock);
+	netif_freeze_queues(dev);
+}
+EXPORT_SYMBOL(netif_tx_lock);
+
+static void netif_unfreeze_queues(struct net_device *dev)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+		/* No need to grab the _xmit_lock here.  If the
+		 * queue is not stopped for another reason, we
+		 * force a schedule.
+		 */
+		clear_bit(__QUEUE_STATE_FROZEN, &txq->state);
+		netif_schedule_queue(txq);
+	}
+}
+
+void netif_tx_unlock(struct net_device *dev)
+{
+	netif_unfreeze_queues(dev);
+	spin_unlock(&dev->tx_global_lock);
+}
+EXPORT_SYMBOL(netif_tx_unlock);
+
+static void dev_watchdog(struct timer_list *t)
 {
-	struct net_device *dev = (struct net_device *)arg;
+	struct net_device *dev = timer_container_of(dev, t, watchdog_timer);
+	bool release = true;
 
-	netif_tx_lock(dev);
+	spin_lock(&dev->tx_global_lock);
 	if (!qdisc_tx_is_noop(dev)) {
 		if (netif_device_present(dev) &&
 		    netif_running(dev) &&
 		    netif_carrier_ok(dev)) {
-			int some_queue_timedout = 0;
+			unsigned int timedout_ms = 0;
 			unsigned int i;
 			unsigned long trans_start;
+			unsigned long oldest_start = jiffies;
 
 			for (i = 0; i < dev->num_tx_queues; i++) {
 				struct netdev_queue *txq;
 
 				txq = netdev_get_tx_queue(dev, i);
-				trans_start = txq->trans_start;
-				if (netif_xmit_stopped(txq) &&
-				    time_after(jiffies, (trans_start +
-							 dev->watchdog_timeo))) {
-					some_queue_timedout = 1;
-					txq->trans_timeout++;
+				if (!netif_xmit_stopped(txq))
+					continue;
+
+				/* Paired with WRITE_ONCE() + smp_mb...() in
+				 * netdev_tx_sent_queue() and netif_tx_stop_queue().
+				 */
+				smp_mb();
+				trans_start = READ_ONCE(txq->trans_start);
+
+				if (time_after(jiffies, trans_start + dev->watchdog_timeo)) {
+					timedout_ms = jiffies_to_msecs(jiffies - trans_start);
+					atomic_long_inc(&txq->trans_timeout);
 					break;
 				}
+				if (time_after(oldest_start, trans_start))
+					oldest_start = trans_start;
 			}
 
-			if (some_queue_timedout) {
-				WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
-				       dev->name, netdev_drivername(dev), i);
-				dev->netdev_ops->ndo_tx_timeout(dev);
+			if (unlikely(timedout_ms)) {
+				trace_net_dev_xmit_timeout(dev, i);
+				netdev_crit(dev, "NETDEV WATCHDOG: CPU: %d: transmit queue %u timed out %u ms\n",
+					    raw_smp_processor_id(),
+					    i, timedout_ms);
+				netif_freeze_queues(dev);
+				dev->netdev_ops->ndo_tx_timeout(dev, i);
+				netif_unfreeze_queues(dev);
 			}
 			if (!mod_timer(&dev->watchdog_timer,
-				       round_jiffies(jiffies +
+				       round_jiffies(oldest_start +
 						     dev->watchdog_timeo)))
-				dev_hold(dev);
+				release = false;
 		}
 	}
-	netif_tx_unlock(dev);
+	spin_unlock(&dev->tx_global_lock);
 
-	dev_put(dev);
+	if (release)
+		netdev_put(dev, &dev->watchdog_dev_tracker);
 }
 
-void __netdev_watchdog_up(struct net_device *dev)
+void netdev_watchdog_up(struct net_device *dev)
 {
-	if (dev->netdev_ops->ndo_tx_timeout) {
-		if (dev->watchdog_timeo <= 0)
-			dev->watchdog_timeo = 5*HZ;
-		if (!mod_timer(&dev->watchdog_timer,
-			       round_jiffies(jiffies + dev->watchdog_timeo)))
-			dev_hold(dev);
-	}
-}
-
-static void dev_watchdog_up(struct net_device *dev)
-{
-	__netdev_watchdog_up(dev);
+	if (!dev->netdev_ops->ndo_tx_timeout)
+		return;
+	if (dev->watchdog_timeo <= 0)
+		dev->watchdog_timeo = 5*HZ;
+	if (!mod_timer(&dev->watchdog_timer,
+		       round_jiffies(jiffies + dev->watchdog_timeo)))
+		netdev_hold(dev, &dev->watchdog_dev_tracker,
+			    GFP_ATOMIC);
 }
+EXPORT_SYMBOL_GPL(netdev_watchdog_up);
 
-static void dev_watchdog_down(struct net_device *dev)
+static void netdev_watchdog_down(struct net_device *dev)
 {
 	netif_tx_lock_bh(dev);
-	if (del_timer(&dev->watchdog_timer))
-		dev_put(dev);
+	if (timer_delete(&dev->watchdog_timer))
+		netdev_put(dev, &dev->watchdog_dev_tracker);
 	netif_tx_unlock_bh(dev);
 }
 
@@ -355,17 +580,17 @@ static void dev_watchdog_down(struct net_device *dev)
  *	netif_carrier_on - set carrier
  *	@dev: network device
  *
- * Device has detected that carrier.
+ * Device has detected acquisition of carrier.
  */
 void netif_carrier_on(struct net_device *dev)
 {
 	if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
 		if (dev->reg_state == NETREG_UNINITIALIZED)
 			return;
-		atomic_inc(&dev->carrier_changes);
+		atomic_inc(&dev->carrier_up_count);
 		linkwatch_fire_event(dev);
 		if (netif_running(dev))
-			__netdev_watchdog_up(dev);
+			netdev_watchdog_up(dev);
 	}
 }
 EXPORT_SYMBOL(netif_carrier_on);
@@ -381,12 +606,30 @@ void netif_carrier_off(struct net_device *dev)
 	if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
 		if (dev->reg_state == NETREG_UNINITIALIZED)
 			return;
-		atomic_inc(&dev->carrier_changes);
+		atomic_inc(&dev->carrier_down_count);
 		linkwatch_fire_event(dev);
 	}
 }
 EXPORT_SYMBOL(netif_carrier_off);
 
+/**
+ *	netif_carrier_event - report carrier state event
+ *	@dev: network device
+ *
+ * Device has detected a carrier event but the carrier state wasn't changed.
+ * Use in drivers when querying carrier state asynchronously, to avoid missing
+ * events (link flaps) if link recovers before it's queried.
+ */
+void netif_carrier_event(struct net_device *dev)
+{
+	if (dev->reg_state == NETREG_UNINITIALIZED)
+		return;
+	atomic_inc(&dev->carrier_up_count);
+	atomic_inc(&dev->carrier_down_count);
+	linkwatch_fire_event(dev);
+}
+EXPORT_SYMBOL_GPL(netif_carrier_event);
+
 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
    under all circumstances. It is difficult to invent anything faster or
    cheaper.
@@ -395,6 +638,7 @@ EXPORT_SYMBOL(netif_carrier_off);
 static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
 			struct sk_buff **to_free)
 {
+	dev_core_stats_tx_dropped_inc(skb->dev);
 	__qdisc_drop(skb, to_free);
 	return NET_XMIT_CN;
 }
@@ -414,8 +658,8 @@ struct Qdisc_ops noop_qdisc_ops __read_mostly = {
 };
 
 static struct netdev_queue noop_netdev_queue = {
-	.qdisc		=	&noop_qdisc,
-	.qdisc_sleeping	=	&noop_qdisc,
+	RCU_POINTER_INITIALIZER(qdisc, &noop_qdisc),
+	RCU_POINTER_INITIALIZER(qdisc_sleeping, &noop_qdisc),
 };
 
 struct Qdisc noop_qdisc = {
@@ -425,12 +669,23 @@ struct Qdisc noop_qdisc = {
 	.ops		=	&noop_qdisc_ops,
 	.q.lock		=	__SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
 	.dev_queue	=	&noop_netdev_queue,
-	.running	=	SEQCNT_ZERO(noop_qdisc.running),
-	.busylock	=	__SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
+	.gso_skb = {
+		.next = (struct sk_buff *)&noop_qdisc.gso_skb,
+		.prev = (struct sk_buff *)&noop_qdisc.gso_skb,
+		.qlen = 0,
+		.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.gso_skb.lock),
+	},
+	.skb_bad_txq = {
+		.next = (struct sk_buff *)&noop_qdisc.skb_bad_txq,
+		.prev = (struct sk_buff *)&noop_qdisc.skb_bad_txq,
+		.qlen = 0,
+		.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.skb_bad_txq.lock),
+	},
 };
 EXPORT_SYMBOL(noop_qdisc);
 
-static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt)
+static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt,
+			struct netlink_ext_ack *extack)
 {
 	/* register_qdisc() assigns a default of noop_enqueue if unset,
 	 * but __dev_queue_xmit() treats noqueue only as such
@@ -449,9 +704,10 @@ struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
 	.owner		=	THIS_MODULE,
 };
 
-static const u8 prio2band[TC_PRIO_MAX + 1] = {
-	1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
+const u8 sch_default_prio2band[TC_PRIO_MAX + 1] = {
+	1, 2, 2, 2, 1, 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1
 };
+EXPORT_SYMBOL(sch_default_prio2band);
 
 /* 3-band FIFO queue: old style, but should be a bit faster than
    generic prio+fifo combination.
@@ -461,100 +717,133 @@ static const u8 prio2band[TC_PRIO_MAX + 1] = {
 
 /*
  * Private data for a pfifo_fast scheduler containing:
- * 	- queues for the three band
- * 	- bitmap indicating which of the bands contain skbs
+ *	- rings for priority bands
  */
 struct pfifo_fast_priv {
-	u32 bitmap;
-	struct qdisc_skb_head q[PFIFO_FAST_BANDS];
+	struct skb_array q[PFIFO_FAST_BANDS];
 };
 
-/*
- * Convert a bitmap to the first band number where an skb is queued, where:
- * 	bitmap=0 means there are no skbs on any band.
- * 	bitmap=1 means there is an skb on band 0.
- *	bitmap=7 means there are skbs on all 3 bands, etc.
- */
-static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
-
-static inline struct qdisc_skb_head *band2list(struct pfifo_fast_priv *priv,
-					     int band)
+static inline struct skb_array *band2list(struct pfifo_fast_priv *priv,
+					  int band)
 {
-	return priv->q + band;
+	return &priv->q[band];
 }
 
 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
 			      struct sk_buff **to_free)
 {
-	if (qdisc->q.qlen < qdisc_dev(qdisc)->tx_queue_len) {
-		int band = prio2band[skb->priority & TC_PRIO_MAX];
-		struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-		struct qdisc_skb_head *list = band2list(priv, band);
+	int band = sch_default_prio2band[skb->priority & TC_PRIO_MAX];
+	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
+	struct skb_array *q = band2list(priv, band);
+	unsigned int pkt_len = qdisc_pkt_len(skb);
+	int err;
 
-		priv->bitmap |= (1 << band);
-		qdisc->q.qlen++;
-		return __qdisc_enqueue_tail(skb, qdisc, list);
+	err = skb_array_produce(q, skb);
+
+	if (unlikely(err)) {
+		tcf_set_drop_reason(skb, SKB_DROP_REASON_QDISC_OVERLIMIT);
+
+		if (qdisc_is_percpu_stats(qdisc))
+			return qdisc_drop_cpu(skb, qdisc, to_free);
+		else
+			return qdisc_drop(skb, qdisc, to_free);
 	}
 
-	return qdisc_drop(skb, qdisc, to_free);
+	qdisc_update_stats_at_enqueue(qdisc, pkt_len);
+	return NET_XMIT_SUCCESS;
 }
 
 static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
 {
 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-	int band = bitmap2band[priv->bitmap];
+	struct sk_buff *skb = NULL;
+	bool need_retry = true;
+	int band;
 
-	if (likely(band >= 0)) {
-		struct qdisc_skb_head *qh = band2list(priv, band);
-		struct sk_buff *skb = __qdisc_dequeue_head(qh);
+retry:
+	for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
+		struct skb_array *q = band2list(priv, band);
 
-		if (likely(skb != NULL)) {
-			qdisc_qstats_backlog_dec(qdisc, skb);
-			qdisc_bstats_update(qdisc, skb);
-		}
+		if (__skb_array_empty(q))
+			continue;
+
+		skb = __skb_array_consume(q);
+	}
+	if (likely(skb)) {
+		qdisc_update_stats_at_dequeue(qdisc, skb);
+	} else if (need_retry &&
+		   READ_ONCE(qdisc->state) & QDISC_STATE_NON_EMPTY) {
+		/* Delay clearing the STATE_MISSED here to reduce
+		 * the overhead of the second spin_trylock() in
+		 * qdisc_run_begin() and __netif_schedule() calling
+		 * in qdisc_run_end().
+		 */
+		clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
+		clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);
+
+		/* Make sure dequeuing happens after clearing
+		 * STATE_MISSED.
+		 */
+		smp_mb__after_atomic();
 
-		qdisc->q.qlen--;
-		if (qh->qlen == 0)
-			priv->bitmap &= ~(1 << band);
+		need_retry = false;
 
-		return skb;
+		goto retry;
 	}
 
-	return NULL;
+	return skb;
 }
 
 static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
 {
 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-	int band = bitmap2band[priv->bitmap];
+	struct sk_buff *skb = NULL;
+	int band;
 
-	if (band >= 0) {
-		struct qdisc_skb_head *qh = band2list(priv, band);
+	for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
+		struct skb_array *q = band2list(priv, band);
 
-		return qh->head;
+		skb = __skb_array_peek(q);
 	}
 
-	return NULL;
+	return skb;
 }
 
 static void pfifo_fast_reset(struct Qdisc *qdisc)
 {
-	int prio;
+	int i, band;
 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 
-	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
-		__qdisc_reset_queue(band2list(priv, prio));
+	for (band = 0; band < PFIFO_FAST_BANDS; band++) {
+		struct skb_array *q = band2list(priv, band);
+		struct sk_buff *skb;
 
-	priv->bitmap = 0;
-	qdisc->qstats.backlog = 0;
-	qdisc->q.qlen = 0;
+		/* NULL ring is possible if destroy path is due to a failed
+		 * skb_array_init() in pfifo_fast_init() case.
+		 */
+		if (!q->ring.queue)
+			continue;
+
+		while ((skb = __skb_array_consume(q)) != NULL)
+			kfree_skb(skb);
+	}
+
+	if (qdisc_is_percpu_stats(qdisc)) {
+		for_each_possible_cpu(i) {
+			struct gnet_stats_queue *q;
+
+			q = per_cpu_ptr(qdisc->cpu_qstats, i);
+			q->backlog = 0;
+			q->qlen = 0;
+		}
+	}
 }
 
 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
 {
 	struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
 
-	memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
+	memcpy(&opt.priomap, sch_default_prio2band, TC_PRIO_MAX + 1);
 	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 		goto nla_put_failure;
 	return skb->len;
@@ -563,19 +852,68 @@ nla_put_failure:
 	return -1;
 }
 
-static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
+static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,
+			   struct netlink_ext_ack *extack)
 {
-	int prio;
+	unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len;
 	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
+	int prio;
+
+	/* guard against zero length rings */
+	if (!qlen)
+		return -EINVAL;
 
-	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
-		qdisc_skb_head_init(band2list(priv, prio));
+	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
+		struct skb_array *q = band2list(priv, prio);
+		int err;
+
+		err = skb_array_init(q, qlen, GFP_KERNEL);
+		if (err)
+			return -ENOMEM;
+	}
 
 	/* Can by-pass the queue discipline */
 	qdisc->flags |= TCQ_F_CAN_BYPASS;
 	return 0;
 }
 
+static void pfifo_fast_destroy(struct Qdisc *sch)
+{
+	struct pfifo_fast_priv *priv = qdisc_priv(sch);
+	int prio;
+
+	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
+		struct skb_array *q = band2list(priv, prio);
+
+		/* NULL ring is possible if destroy path is due to a failed
+		 * skb_array_init() in pfifo_fast_init() case.
+		 */
+		if (!q->ring.queue)
+			continue;
+		/* Destroy ring but no need to kfree_skb because a call to
+		 * pfifo_fast_reset() has already done that work.
+		 */
+		ptr_ring_cleanup(&q->ring, NULL);
+	}
+}
+
+static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,
+					  unsigned int new_len)
+{
+	struct pfifo_fast_priv *priv = qdisc_priv(sch);
+	struct skb_array *bands[PFIFO_FAST_BANDS];
+	int prio;
+
+	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
+		struct skb_array *q = band2list(priv, prio);
+
+		bands[prio] = q;
+	}
+
+	return skb_array_resize_multiple_bh(bands, PFIFO_FAST_BANDS, new_len,
+					    GFP_KERNEL);
+}
+
 struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 	.id		=	"pfifo_fast",
 	.priv_size	=	sizeof(struct pfifo_fast_priv),
@@ -583,83 +921,103 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 	.dequeue	=	pfifo_fast_dequeue,
 	.peek		=	pfifo_fast_peek,
 	.init		=	pfifo_fast_init,
+	.destroy	=	pfifo_fast_destroy,
 	.reset		=	pfifo_fast_reset,
 	.dump		=	pfifo_fast_dump,
+	.change_tx_queue_len =  pfifo_fast_change_tx_queue_len,
 	.owner		=	THIS_MODULE,
+	.static_flags	=	TCQ_F_NOLOCK | TCQ_F_CPUSTATS,
 };
 EXPORT_SYMBOL(pfifo_fast_ops);
 
 static struct lock_class_key qdisc_tx_busylock;
-static struct lock_class_key qdisc_running_key;
 
 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
-			  const struct Qdisc_ops *ops)
+			  const struct Qdisc_ops *ops,
+			  struct netlink_ext_ack *extack)
 {
-	void *p;
 	struct Qdisc *sch;
-	unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size;
+	unsigned int size = sizeof(*sch) + ops->priv_size;
 	int err = -ENOBUFS;
-	struct net_device *dev = dev_queue->dev;
+	struct net_device *dev;
+
+	if (!dev_queue) {
+		NL_SET_ERR_MSG(extack, "No device queue given");
+		err = -EINVAL;
+		goto errout;
+	}
 
-	p = kzalloc_node(size, GFP_KERNEL,
-			 netdev_queue_numa_node_read(dev_queue));
+	dev = dev_queue->dev;
+	sch = kzalloc_node(size, GFP_KERNEL, netdev_queue_numa_node_read(dev_queue));
 
-	if (!p)
+	if (!sch)
 		goto errout;
-	sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
-	/* if we got non aligned memory, ask more and do alignment ourself */
-	if (sch != p) {
-		kfree(p);
-		p = kzalloc_node(size + QDISC_ALIGNTO - 1, GFP_KERNEL,
-				 netdev_queue_numa_node_read(dev_queue));
-		if (!p)
-			goto errout;
-		sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
-		sch->padded = (char *) sch - (char *) p;
-	}
-	qdisc_skb_head_init(&sch->q);
+	__skb_queue_head_init(&sch->gso_skb);
+	__skb_queue_head_init(&sch->skb_bad_txq);
+	gnet_stats_basic_sync_init(&sch->bstats);
+	lockdep_register_key(&sch->root_lock_key);
 	spin_lock_init(&sch->q.lock);
+	lockdep_set_class(&sch->q.lock, &sch->root_lock_key);
+
+	if (ops->static_flags & TCQ_F_CPUSTATS) {
+		sch->cpu_bstats =
+			netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
+		if (!sch->cpu_bstats)
+			goto errout1;
+
+		sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
+		if (!sch->cpu_qstats) {
+			free_percpu(sch->cpu_bstats);
+			goto errout1;
+		}
+	}
 
-	spin_lock_init(&sch->busylock);
-	lockdep_set_class(&sch->busylock,
+	/* seqlock has the same scope of busylock, for NOLOCK qdisc */
+	spin_lock_init(&sch->seqlock);
+	lockdep_set_class(&sch->seqlock,
 			  dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
 
-	seqcount_init(&sch->running);
-	lockdep_set_class(&sch->running,
-			  dev->qdisc_running_key ?: &qdisc_running_key);
-
 	sch->ops = ops;
+	sch->flags = ops->static_flags;
 	sch->enqueue = ops->enqueue;
 	sch->dequeue = ops->dequeue;
 	sch->dev_queue = dev_queue;
-	dev_hold(dev);
+	netdev_hold(dev, &sch->dev_tracker, GFP_KERNEL);
 	refcount_set(&sch->refcnt, 1);
 
 	return sch;
+errout1:
+	lockdep_unregister_key(&sch->root_lock_key);
+	kfree(sch);
 errout:
 	return ERR_PTR(err);
 }
 
 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
 				const struct Qdisc_ops *ops,
-				unsigned int parentid)
+				unsigned int parentid,
+				struct netlink_ext_ack *extack)
 {
 	struct Qdisc *sch;
 
-	if (!try_module_get(ops->owner))
+	if (!bpf_try_module_get(ops, ops->owner)) {
+		NL_SET_ERR_MSG(extack, "Failed to increase module reference counter");
 		return NULL;
+	}
 
-	sch = qdisc_alloc(dev_queue, ops);
+	sch = qdisc_alloc(dev_queue, ops, extack);
 	if (IS_ERR(sch)) {
-		module_put(ops->owner);
+		bpf_module_put(ops, ops->owner);
 		return NULL;
 	}
 	sch->parent = parentid;
 
-	if (!ops->init || ops->init(sch, NULL) == 0)
+	if (!ops->init || ops->init(sch, NULL, extack) == 0) {
+		trace_qdisc_create(ops, dev_queue->dev, parentid);
 		return sch;
+	}
 
-	qdisc_destroy(sch);
+	qdisc_put(sch);
 	return NULL;
 }
 EXPORT_SYMBOL(qdisc_create_dflt);
@@ -670,39 +1028,40 @@ void qdisc_reset(struct Qdisc *qdisc)
 {
 	const struct Qdisc_ops *ops = qdisc->ops;
 
+	trace_qdisc_reset(qdisc);
+
 	if (ops->reset)
 		ops->reset(qdisc);
 
-	kfree_skb(qdisc->skb_bad_txq);
-	qdisc->skb_bad_txq = NULL;
+	__skb_queue_purge(&qdisc->gso_skb);
+	__skb_queue_purge(&qdisc->skb_bad_txq);
 
-	if (qdisc->gso_skb) {
-		kfree_skb_list(qdisc->gso_skb);
-		qdisc->gso_skb = NULL;
-	}
 	qdisc->q.qlen = 0;
+	qdisc->qstats.backlog = 0;
 }
 EXPORT_SYMBOL(qdisc_reset);
 
-static void qdisc_rcu_free(struct rcu_head *head)
+void qdisc_free(struct Qdisc *qdisc)
 {
-	struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head);
-
 	if (qdisc_is_percpu_stats(qdisc)) {
 		free_percpu(qdisc->cpu_bstats);
 		free_percpu(qdisc->cpu_qstats);
 	}
 
-	kfree((char *) qdisc - qdisc->padded);
+	kfree(qdisc);
 }
 
-void qdisc_destroy(struct Qdisc *qdisc)
+static void qdisc_free_cb(struct rcu_head *head)
 {
-	const struct Qdisc_ops  *ops = qdisc->ops;
+	struct Qdisc *q = container_of(head, struct Qdisc, rcu);
 
-	if (qdisc->flags & TCQ_F_BUILTIN ||
-	    !refcount_dec_and_test(&qdisc->refcnt))
-		return;
+	qdisc_free(q);
+}
+
+static void __qdisc_destroy(struct Qdisc *qdisc)
+{
+	const struct Qdisc_ops  *ops = qdisc->ops;
+	struct net_device *dev = qdisc_dev(qdisc);
 
 #ifdef CONFIG_NET_SCHED
 	qdisc_hash_del(qdisc);
@@ -710,42 +1069,73 @@ void qdisc_destroy(struct Qdisc *qdisc)
 	qdisc_put_stab(rtnl_dereference(qdisc->stab));
 #endif
 	gen_kill_estimator(&qdisc->rate_est);
-	if (ops->reset)
-		ops->reset(qdisc);
+
+	qdisc_reset(qdisc);
+
+
 	if (ops->destroy)
 		ops->destroy(qdisc);
 
-	module_put(ops->owner);
-	dev_put(qdisc_dev(qdisc));
+	lockdep_unregister_key(&qdisc->root_lock_key);
+	bpf_module_put(ops, ops->owner);
+	netdev_put(dev, &qdisc->dev_tracker);
 
-	kfree_skb_list(qdisc->gso_skb);
-	kfree_skb(qdisc->skb_bad_txq);
-	/*
-	 * gen_estimator est_timer() might access qdisc->q.lock,
-	 * wait a RCU grace period before freeing qdisc.
-	 */
-	call_rcu(&qdisc->rcu_head, qdisc_rcu_free);
+	trace_qdisc_destroy(qdisc);
+
+	call_rcu(&qdisc->rcu, qdisc_free_cb);
+}
+
+void qdisc_destroy(struct Qdisc *qdisc)
+{
+	if (qdisc->flags & TCQ_F_BUILTIN)
+		return;
+
+	__qdisc_destroy(qdisc);
+}
+
+void qdisc_put(struct Qdisc *qdisc)
+{
+	if (!qdisc)
+		return;
+
+	if (qdisc->flags & TCQ_F_BUILTIN ||
+	    !refcount_dec_and_test(&qdisc->refcnt))
+		return;
+
+	__qdisc_destroy(qdisc);
 }
-EXPORT_SYMBOL(qdisc_destroy);
+EXPORT_SYMBOL(qdisc_put);
+
+/* Version of qdisc_put() that is called with rtnl mutex unlocked.
+ * Intended to be used as optimization, this function only takes rtnl lock if
+ * qdisc reference counter reached zero.
+ */
+
+void qdisc_put_unlocked(struct Qdisc *qdisc)
+{
+	if (qdisc->flags & TCQ_F_BUILTIN ||
+	    !refcount_dec_and_rtnl_lock(&qdisc->refcnt))
+		return;
+
+	__qdisc_destroy(qdisc);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(qdisc_put_unlocked);
 
 /* Attach toplevel qdisc to device queue. */
 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 			      struct Qdisc *qdisc)
 {
-	struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
+	struct Qdisc *oqdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
 	spinlock_t *root_lock;
 
 	root_lock = qdisc_lock(oqdisc);
 	spin_lock_bh(root_lock);
 
-	/* Prune old scheduler */
-	if (oqdisc && refcount_read(&oqdisc->refcnt) <= 1)
-		qdisc_reset(oqdisc);
-
 	/* ... and graft new one */
 	if (qdisc == NULL)
 		qdisc = &noop_qdisc;
-	dev_queue->qdisc_sleeping = qdisc;
+	rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc);
 	rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
 
 	spin_unlock_bh(root_lock);
@@ -754,6 +1144,21 @@ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 }
 EXPORT_SYMBOL(dev_graft_qdisc);
 
+static void shutdown_scheduler_queue(struct net_device *dev,
+				     struct netdev_queue *dev_queue,
+				     void *_qdisc_default)
+{
+	struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
+	struct Qdisc *qdisc_default = _qdisc_default;
+
+	if (qdisc) {
+		rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
+		rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc_default);
+
+		qdisc_put(qdisc);
+	}
+}
+
 static void attach_one_default_qdisc(struct net_device *dev,
 				     struct netdev_queue *dev_queue,
 				     void *_unused)
@@ -763,15 +1168,16 @@ static void attach_one_default_qdisc(struct net_device *dev,
 
 	if (dev->priv_flags & IFF_NO_QUEUE)
 		ops = &noqueue_qdisc_ops;
+	else if(dev->type == ARPHRD_CAN)
+		ops = &pfifo_fast_ops;
 
-	qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT);
-	if (!qdisc) {
-		netdev_info(dev, "activation failed\n");
+	qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT, NULL);
+	if (!qdisc)
 		return;
-	}
+
 	if (!netif_is_multiqueue(dev))
 		qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
-	dev_queue->qdisc_sleeping = qdisc;
+	rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc);
 }
 
 static void attach_default_qdiscs(struct net_device *dev)
@@ -784,18 +1190,34 @@ static void attach_default_qdiscs(struct net_device *dev)
 	if (!netif_is_multiqueue(dev) ||
 	    dev->priv_flags & IFF_NO_QUEUE) {
 		netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
-		dev->qdisc = txq->qdisc_sleeping;
-		refcount_inc(&dev->qdisc->refcnt);
+		qdisc = rtnl_dereference(txq->qdisc_sleeping);
+		rcu_assign_pointer(dev->qdisc, qdisc);
+		qdisc_refcount_inc(qdisc);
 	} else {
-		qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
+		qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT, NULL);
 		if (qdisc) {
-			dev->qdisc = qdisc;
+			rcu_assign_pointer(dev->qdisc, qdisc);
 			qdisc->ops->attach(qdisc);
 		}
 	}
+	qdisc = rtnl_dereference(dev->qdisc);
+
+	/* Detect default qdisc setup/init failed and fallback to "noqueue" */
+	if (qdisc == &noop_qdisc) {
+		netdev_warn(dev, "default qdisc (%s) fail, fallback to %s\n",
+			    default_qdisc_ops->id, noqueue_qdisc_ops.id);
+		netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
+		dev->priv_flags |= IFF_NO_QUEUE;
+		netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
+		qdisc = rtnl_dereference(txq->qdisc_sleeping);
+		rcu_assign_pointer(dev->qdisc, qdisc);
+		qdisc_refcount_inc(qdisc);
+		dev->priv_flags ^= IFF_NO_QUEUE;
+	}
+
 #ifdef CONFIG_NET_SCHED
-	if (dev->qdisc != &noop_qdisc)
-		qdisc_hash_add(dev->qdisc, false);
+	if (qdisc != &noop_qdisc)
+		qdisc_hash_add(qdisc, false);
 #endif
 }
 
@@ -803,7 +1225,7 @@ static void transition_one_qdisc(struct net_device *dev,
 				 struct netdev_queue *dev_queue,
 				 void *_need_watchdog)
 {
-	struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
+	struct Qdisc *new_qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
 	int *need_watchdog_p = _need_watchdog;
 
 	if (!(new_qdisc->flags & TCQ_F_BUILTIN))
@@ -811,7 +1233,7 @@ static void transition_one_qdisc(struct net_device *dev,
 
 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
 	if (need_watchdog_p) {
-		dev_queue->trans_start = 0;
+		WRITE_ONCE(dev_queue->trans_start, 0);
 		*need_watchdog_p = 1;
 	}
 }
@@ -825,7 +1247,7 @@ void dev_activate(struct net_device *dev)
 	 * and noqueue_qdisc for virtual interfaces
 	 */
 
-	if (dev->qdisc == &noop_qdisc)
+	if (rtnl_dereference(dev->qdisc) == &noop_qdisc)
 		attach_default_qdiscs(dev);
 
 	if (!netif_carrier_ok(dev))
@@ -839,29 +1261,59 @@ void dev_activate(struct net_device *dev)
 
 	if (need_watchdog) {
 		netif_trans_update(dev);
-		dev_watchdog_up(dev);
+		netdev_watchdog_up(dev);
 	}
 }
 EXPORT_SYMBOL(dev_activate);
 
+static void qdisc_deactivate(struct Qdisc *qdisc)
+{
+	if (qdisc->flags & TCQ_F_BUILTIN)
+		return;
+
+	set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
+}
+
 static void dev_deactivate_queue(struct net_device *dev,
 				 struct netdev_queue *dev_queue,
-				 void *_qdisc_default)
+				 void *_sync_needed)
 {
-	struct Qdisc *qdisc_default = _qdisc_default;
+	bool *sync_needed = _sync_needed;
 	struct Qdisc *qdisc;
 
 	qdisc = rtnl_dereference(dev_queue->qdisc);
 	if (qdisc) {
-		spin_lock_bh(qdisc_lock(qdisc));
+		if (qdisc->enqueue)
+			*sync_needed = true;
+		qdisc_deactivate(qdisc);
+		rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
+	}
+}
 
-		if (!(qdisc->flags & TCQ_F_BUILTIN))
-			set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
+static void dev_reset_queue(struct net_device *dev,
+			    struct netdev_queue *dev_queue,
+			    void *_unused)
+{
+	struct Qdisc *qdisc;
+	bool nolock;
 
-		rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
-		qdisc_reset(qdisc);
+	qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
+	if (!qdisc)
+		return;
+
+	nolock = qdisc->flags & TCQ_F_NOLOCK;
+
+	if (nolock)
+		spin_lock_bh(&qdisc->seqlock);
+	spin_lock_bh(qdisc_lock(qdisc));
+
+	qdisc_reset(qdisc);
 
-		spin_unlock_bh(qdisc_lock(qdisc));
+	spin_unlock_bh(qdisc_lock(qdisc));
+	if (nolock) {
+		clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
+		clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);
+		spin_unlock_bh(&qdisc->seqlock);
 	}
 }
 
@@ -876,9 +1328,9 @@ static bool some_qdisc_is_busy(struct net_device *dev)
 		int val;
 
 		dev_queue = netdev_get_tx_queue(dev, i);
-		q = dev_queue->qdisc_sleeping;
-		root_lock = qdisc_lock(q);
+		q = rtnl_dereference(dev_queue->qdisc_sleeping);
 
+		root_lock = qdisc_lock(q);
 		spin_lock_bh(root_lock);
 
 		val = (qdisc_is_running(q) ||
@@ -901,31 +1353,40 @@ static bool some_qdisc_is_busy(struct net_device *dev)
  */
 void dev_deactivate_many(struct list_head *head)
 {
-	struct net_device *dev;
 	bool sync_needed = false;
+	struct net_device *dev;
 
 	list_for_each_entry(dev, head, close_list) {
 		netdev_for_each_tx_queue(dev, dev_deactivate_queue,
-					 &noop_qdisc);
+					 &sync_needed);
 		if (dev_ingress_queue(dev))
 			dev_deactivate_queue(dev, dev_ingress_queue(dev),
-					     &noop_qdisc);
+					     &sync_needed);
 
-		dev_watchdog_down(dev);
-		sync_needed |= !dev->dismantle;
+		netdev_watchdog_down(dev);
 	}
 
-	/* Wait for outstanding qdisc-less dev_queue_xmit calls.
-	 * This is avoided if all devices are in dismantle phase :
-	 * Caller will call synchronize_net() for us
-	 */
+	/* Wait for outstanding qdisc enqueuing calls. */
 	if (sync_needed)
 		synchronize_net();
 
+	list_for_each_entry(dev, head, close_list) {
+		netdev_for_each_tx_queue(dev, dev_reset_queue, NULL);
+
+		if (dev_ingress_queue(dev))
+			dev_reset_queue(dev, dev_ingress_queue(dev), NULL);
+	}
+
 	/* Wait for outstanding qdisc_run calls. */
-	list_for_each_entry(dev, head, close_list)
-		while (some_qdisc_is_busy(dev))
-			yield();
+	list_for_each_entry(dev, head, close_list) {
+		while (some_qdisc_is_busy(dev)) {
+			/* wait_event() would avoid this sleep-loop but would
+			 * require expensive checks in the fast paths of packet
+			 * processing which isn't worth it.
+			 */
+			schedule_timeout_uninterruptible(1);
+		}
+	}
 }
 
 void dev_deactivate(struct net_device *dev)
@@ -938,6 +1399,72 @@ void dev_deactivate(struct net_device *dev)
 }
 EXPORT_SYMBOL(dev_deactivate);
 
+static int qdisc_change_tx_queue_len(struct net_device *dev,
+				     struct netdev_queue *dev_queue)
+{
+	struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
+	const struct Qdisc_ops *ops = qdisc->ops;
+
+	if (ops->change_tx_queue_len)
+		return ops->change_tx_queue_len(qdisc, dev->tx_queue_len);
+	return 0;
+}
+
+void dev_qdisc_change_real_num_tx(struct net_device *dev,
+				  unsigned int new_real_tx)
+{
+	struct Qdisc *qdisc = rtnl_dereference(dev->qdisc);
+
+	if (qdisc->ops->change_real_num_tx)
+		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 = rtnl_dereference(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 = rtnl_dereference(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;
+	unsigned int i;
+	int ret = 0;
+
+	if (up)
+		dev_deactivate(dev);
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		ret = qdisc_change_tx_queue_len(dev, &dev->_tx[i]);
+
+		/* TODO: revert changes on a partial failure */
+		if (ret)
+			break;
+	}
+
+	if (up)
+		dev_activate(dev);
+	return ret;
+}
+
 static void dev_init_scheduler_queue(struct net_device *dev,
 				     struct netdev_queue *dev_queue,
 				     void *_qdisc)
@@ -945,32 +1472,17 @@ static void dev_init_scheduler_queue(struct net_device *dev,
 	struct Qdisc *qdisc = _qdisc;
 
 	rcu_assign_pointer(dev_queue->qdisc, qdisc);
-	dev_queue->qdisc_sleeping = qdisc;
+	rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc);
 }
 
 void dev_init_scheduler(struct net_device *dev)
 {
-	dev->qdisc = &noop_qdisc;
+	rcu_assign_pointer(dev->qdisc, &noop_qdisc);
 	netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
 	if (dev_ingress_queue(dev))
 		dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
 
-	setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
-}
-
-static void shutdown_scheduler_queue(struct net_device *dev,
-				     struct netdev_queue *dev_queue,
-				     void *_qdisc_default)
-{
-	struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
-	struct Qdisc *qdisc_default = _qdisc_default;
-
-	if (qdisc) {
-		rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
-		dev_queue->qdisc_sleeping = qdisc_default;
-
-		qdisc_destroy(qdisc);
-	}
+	timer_setup(&dev->watchdog_timer, dev_watchdog, 0);
 }
 
 void dev_shutdown(struct net_device *dev)
@@ -978,44 +1490,130 @@ void dev_shutdown(struct net_device *dev)
 	netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
 	if (dev_ingress_queue(dev))
 		shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
-	qdisc_destroy(dev->qdisc);
-	dev->qdisc = &noop_qdisc;
+	qdisc_put(rtnl_dereference(dev->qdisc));
+	rcu_assign_pointer(dev->qdisc, &noop_qdisc);
 
 	WARN_ON(timer_pending(&dev->watchdog_timer));
 }
 
+/**
+ * psched_ratecfg_precompute__() - Pre-compute values for reciprocal division
+ * @rate:   Rate to compute reciprocal division values of
+ * @mult:   Multiplier for reciprocal division
+ * @shift:  Shift for reciprocal division
+ *
+ * The multiplier and shift for reciprocal division by rate are stored
+ * in mult and shift.
+ *
+ * The deal here is to replace a divide by a reciprocal one
+ * in fast path (a reciprocal divide is a multiply and a shift)
+ *
+ * Normal formula would be :
+ *  time_in_ns = (NSEC_PER_SEC * len) / rate_bps
+ *
+ * We compute mult/shift to use instead :
+ *  time_in_ns = (len * mult) >> shift;
+ *
+ * We try to get the highest possible mult value for accuracy,
+ * but have to make sure no overflows will ever happen.
+ *
+ * reciprocal_value() is not used here it doesn't handle 64-bit values.
+ */
+static void psched_ratecfg_precompute__(u64 rate, u32 *mult, u8 *shift)
+{
+	u64 factor = NSEC_PER_SEC;
+
+	*mult = 1;
+	*shift = 0;
+
+	if (rate <= 0)
+		return;
+
+	for (;;) {
+		*mult = div64_u64(factor, rate);
+		if (*mult & (1U << 31) || factor & (1ULL << 63))
+			break;
+		factor <<= 1;
+		(*shift)++;
+	}
+}
+
 void psched_ratecfg_precompute(struct psched_ratecfg *r,
 			       const struct tc_ratespec *conf,
 			       u64 rate64)
 {
 	memset(r, 0, sizeof(*r));
 	r->overhead = conf->overhead;
+	r->mpu = conf->mpu;
 	r->rate_bytes_ps = max_t(u64, conf->rate, rate64);
 	r->linklayer = (conf->linklayer & TC_LINKLAYER_MASK);
-	r->mult = 1;
-	/*
-	 * The deal here is to replace a divide by a reciprocal one
-	 * in fast path (a reciprocal divide is a multiply and a shift)
-	 *
-	 * Normal formula would be :
-	 *  time_in_ns = (NSEC_PER_SEC * len) / rate_bps
-	 *
-	 * We compute mult/shift to use instead :
-	 *  time_in_ns = (len * mult) >> shift;
-	 *
-	 * We try to get the highest possible mult value for accuracy,
-	 * but have to make sure no overflows will ever happen.
+	psched_ratecfg_precompute__(r->rate_bytes_ps, &r->mult, &r->shift);
+}
+EXPORT_SYMBOL(psched_ratecfg_precompute);
+
+void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64)
+{
+	r->rate_pkts_ps = pktrate64;
+	psched_ratecfg_precompute__(r->rate_pkts_ps, &r->mult, &r->shift);
+}
+EXPORT_SYMBOL(psched_ppscfg_precompute);
+
+void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
+			  struct tcf_proto *tp_head)
+{
+	/* Protected with chain0->filter_chain_lock.
+	 * Can't access chain directly because tp_head can be NULL.
 	 */
-	if (r->rate_bytes_ps > 0) {
-		u64 factor = NSEC_PER_SEC;
-
-		for (;;) {
-			r->mult = div64_u64(factor, r->rate_bytes_ps);
-			if (r->mult & (1U << 31) || factor & (1ULL << 63))
-				break;
-			factor <<= 1;
-			r->shift++;
-		}
+	struct mini_Qdisc *miniq_old =
+		rcu_dereference_protected(*miniqp->p_miniq, 1);
+	struct mini_Qdisc *miniq;
+
+	if (!tp_head) {
+		RCU_INIT_POINTER(*miniqp->p_miniq, NULL);
+	} else {
+		miniq = miniq_old != &miniqp->miniq1 ?
+			&miniqp->miniq1 : &miniqp->miniq2;
+
+		/* We need to make sure that readers won't see the miniq
+		 * we are about to modify. So ensure that at least one RCU
+		 * grace period has elapsed since the miniq was made
+		 * inactive.
+		 */
+		if (IS_ENABLED(CONFIG_PREEMPT_RT))
+			cond_synchronize_rcu(miniq->rcu_state);
+		else if (!poll_state_synchronize_rcu(miniq->rcu_state))
+			synchronize_rcu_expedited();
+
+		miniq->filter_list = tp_head;
+		rcu_assign_pointer(*miniqp->p_miniq, miniq);
 	}
+
+	if (miniq_old)
+		/* This is counterpart of the rcu sync above. We need to
+		 * block potential new user of miniq_old until all readers
+		 * are not seeing it.
+		 */
+		miniq_old->rcu_state = start_poll_synchronize_rcu();
 }
-EXPORT_SYMBOL(psched_ratecfg_precompute);
+EXPORT_SYMBOL(mini_qdisc_pair_swap);
+
+void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
+				struct tcf_block *block)
+{
+	miniqp->miniq1.block = block;
+	miniqp->miniq2.block = block;
+}
+EXPORT_SYMBOL(mini_qdisc_pair_block_init);
+
+void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
+			  struct mini_Qdisc __rcu **p_miniq)
+{
+	miniqp->miniq1.cpu_bstats = qdisc->cpu_bstats;
+	miniqp->miniq1.cpu_qstats = qdisc->cpu_qstats;
+	miniqp->miniq2.cpu_bstats = qdisc->cpu_bstats;
+	miniqp->miniq2.cpu_qstats = qdisc->cpu_qstats;
+	miniqp->miniq1.rcu_state = get_state_synchronize_rcu();
+	miniqp->miniq2.rcu_state = miniqp->miniq1.rcu_state;
+	miniqp->p_miniq = p_miniq;
+}
+EXPORT_SYMBOL(mini_qdisc_pair_init);