Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1447 insertions, 0 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
new file mode 100644
index 000000000..7c1b1eff8
--- /dev/null
+++ b/net/sched/sch_generic.c
@@ -0,0 +1,1447 @@
+/*
+ * 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
+ */
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/init.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/if_vlan.h>
+#include <linux/skb_array.h>
+#include <linux/if_macvlan.h>
+#include <net/sch_generic.h>
+#include <net/pkt_sched.h>
+#include <net/dst.h>
+#include <trace/events/qdisc.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);
+
+/* Main transmission queue. */
+
+/* Modifications to data participating in scheduling must be protected with
+ * qdisc_lock(qdisc) spinlock.
+ *
+ * The idea is the following:
+ * - enqueue, dequeue are serialized via qdisc root lock
+ * - ingress filtering is also serialized via qdisc root lock
+ * - updates to tree and tree walking are only done under the rtnl mutex.
+ */
+
+#define SKB_XOFF_MAGIC ((struct sk_buff *)1UL)
+
+static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q)
+{
+	const struct netdev_queue *txq = q->dev_queue;
+	spinlock_t *lock = NULL;
+	struct sk_buff *skb;
+
+	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_atomic_qlen_dec(q);
+			} else {
+				qdisc_qstats_backlog_dec(q, skb);
+				q->q.qlen--;
+			}
+		} else {
+			skb = SKB_XOFF_MAGIC;
+		}
+	}
+
+	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_atomic_qlen_inc(q);
+	} else {
+		qdisc_qstats_backlog_inc(q, skb);
+		q->q.qlen++;
+	}
+
+	if (lock)
+		spin_unlock(lock);
+}
+
+static inline int __dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
+{
+	while (skb) {
+		struct sk_buff *next = skb->next;
+
+		__skb_queue_tail(&q->gso_skb, skb);
+		q->qstats.requeues++;
+		qdisc_qstats_backlog_inc(q, skb);
+		q->q.qlen++;	/* it's still part of the queue */
+
+		skb = next;
+	}
+	__netif_schedule(q);
+
+	return 0;
+}
+
+static inline int dev_requeue_skb_locked(struct sk_buff *skb, struct Qdisc *q)
+{
+	spinlock_t *lock = qdisc_lock(q);
+
+	spin_lock(lock);
+	while (skb) {
+		struct sk_buff *next = skb->next;
+
+		__skb_queue_tail(&q->gso_skb, skb);
+
+		qdisc_qstats_cpu_requeues_inc(q);
+		qdisc_qstats_cpu_backlog_inc(q, skb);
+		qdisc_qstats_atomic_qlen_inc(q);
+
+		skb = next;
+	}
+	spin_unlock(lock);
+
+	__netif_schedule(q);
+
+	return 0;
+}
+
+static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
+{
+	if (q->flags & TCQ_F_NOLOCK)
+		return dev_requeue_skb_locked(skb, q);
+	else
+		return __dev_requeue_skb(skb, q);
+}
+
+static void try_bulk_dequeue_skb(struct Qdisc *q,
+				 struct sk_buff *skb,
+				 const struct netdev_queue *txq,
+				 int *packets)
+{
+	int bytelimit = qdisc_avail_bulklimit(txq) - skb->len;
+
+	while (bytelimit > 0) {
+		struct sk_buff *nskb = q->dequeue(q);
+
+		if (!nskb)
+			break;
+
+		bytelimit -= nskb->len; /* covers GSO len */
+		skb->next = nskb;
+		skb = nskb;
+		(*packets)++; /* GSO counts as one pkt */
+	}
+	skb->next = NULL;
+}
+
+/* This variant of try_bulk_dequeue_skb() makes sure
+ * all skbs in the chain are for the same txq
+ */
+static void try_bulk_dequeue_skb_slow(struct Qdisc *q,
+				      struct sk_buff *skb,
+				      int *packets)
+{
+	int mapping = skb_get_queue_mapping(skb);
+	struct sk_buff *nskb;
+	int cnt = 0;
+
+	do {
+		nskb = q->dequeue(q);
+		if (!nskb)
+			break;
+		if (unlikely(skb_get_queue_mapping(nskb) != mapping)) {
+			qdisc_enqueue_skb_bad_txq(q, nskb);
+			break;
+		}
+		skb->next = nskb;
+		skb = nskb;
+	} while (++cnt < 8);
+	(*packets) += cnt;
+	skb->next = NULL;
+}
+
+/* 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)
+{
+	const struct netdev_queue *txq = q->dev_queue;
+	struct sk_buff *skb = NULL;
+
+	*packets = 1;
+	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)) {
+			skb = __skb_dequeue(&q->gso_skb);
+			if (qdisc_is_percpu_stats(q)) {
+				qdisc_qstats_cpu_backlog_dec(q, skb);
+				qdisc_qstats_atomic_qlen_dec(q);
+			} else {
+				qdisc_qstats_backlog_dec(q, skb);
+				q->q.qlen--;
+			}
+		} else {
+			skb = NULL;
+		}
+		if (lock)
+			spin_unlock(lock);
+		goto trace;
+	}
+validate:
+	*validate = true;
+
+	if ((q->flags & TCQ_F_ONETXQUEUE) &&
+	    netif_xmit_frozen_or_stopped(txq))
+		return skb;
+
+	skb = qdisc_dequeue_skb_bad_txq(q);
+	if (unlikely(skb)) {
+		if (skb == SKB_XOFF_MAGIC)
+			return NULL;
+		goto bulk;
+	}
+	skb = q->dequeue(q);
+	if (skb) {
+bulk:
+		if (qdisc_may_bulk(q))
+			try_bulk_dequeue_skb(q, skb, txq, packets);
+		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.
+ *
+ * Returns to the caller:
+ *				false  - hardware queue frozen backoff
+ *				true   - feel free to send more pkts
+ */
+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 */
+	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, &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);
+
+		HARD_TX_UNLOCK(dev, txq);
+	} else {
+		if (root_lock)
+			spin_lock(root_lock);
+		return true;
+	}
+
+	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);
+
+		dev_requeue_skb(skb, q);
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * NOTE: Called under qdisc_lock(q) with locally disabled BH.
+ *
+ * running seqcount guarantees only one CPU can process
+ * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
+ * this queue.
+ *
+ *  netif_tx_lock serializes accesses to device driver.
+ *
+ *  qdisc_lock(q) and netif_tx_lock are mutually exclusive,
+ *  if one is grabbed, another must be free.
+ *
+ * Note, that this procedure can be called by a watchdog timer
+ *
+ * Returns to the caller:
+ *				0  - queue is empty or throttled.
+ *				>0 - queue is not empty.
+ *
+ */
+static inline bool qdisc_restart(struct Qdisc *q, int *packets)
+{
+	spinlock_t *root_lock = NULL;
+	struct netdev_queue *txq;
+	struct net_device *dev;
+	struct sk_buff *skb;
+	bool validate;
+
+	/* Dequeue packet */
+	skb = dequeue_skb(q, &validate, packets);
+	if (unlikely(!skb))
+		return false;
+
+	if (!(q->flags & TCQ_F_NOLOCK))
+		root_lock = qdisc_lock(q);
+
+	dev = qdisc_dev(q);
+	txq = skb_get_tx_queue(dev, skb);
+
+	return sch_direct_xmit(skb, q, dev, txq, root_lock, validate);
+}
+
+void __qdisc_run(struct Qdisc *q)
+{
+	int quota = 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;
+		 */
+		quota -= packets;
+		if (quota <= 0 || need_resched()) {
+			__netif_schedule(q);
+			break;
+		}
+	}
+}
+
+unsigned long dev_trans_start(struct net_device *dev)
+{
+	unsigned long val, res;
+	unsigned int i;
+
+	if (is_vlan_dev(dev))
+		dev = vlan_dev_real_dev(dev);
+	else if (netif_is_macvlan(dev))
+		dev = macvlan_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;
+		if (val && time_after(val, res))
+			res = val;
+	}
+
+	return res;
+}
+EXPORT_SYMBOL(dev_trans_start);
+
+static void dev_watchdog(struct timer_list *t)
+{
+	struct net_device *dev = from_timer(dev, t, watchdog_timer);
+
+	netif_tx_lock(dev);
+	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 i;
+			unsigned long trans_start;
+
+			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++;
+					break;
+				}
+			}
+
+			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 (!mod_timer(&dev->watchdog_timer,
+				       round_jiffies(jiffies +
+						     dev->watchdog_timeo)))
+				dev_hold(dev);
+		}
+	}
+	netif_tx_unlock(dev);
+
+	dev_put(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);
+	}
+}
+EXPORT_SYMBOL_GPL(__netdev_watchdog_up);
+
+static void dev_watchdog_up(struct net_device *dev)
+{
+	__netdev_watchdog_up(dev);
+}
+
+static void dev_watchdog_down(struct net_device *dev)
+{
+	netif_tx_lock_bh(dev);
+	if (del_timer(&dev->watchdog_timer))
+		dev_put(dev);
+	netif_tx_unlock_bh(dev);
+}
+
+/**
+ *	netif_carrier_on - set carrier
+ *	@dev: network device
+ *
+ * Device has detected that 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_up_count);
+		linkwatch_fire_event(dev);
+		if (netif_running(dev))
+			__netdev_watchdog_up(dev);
+	}
+}
+EXPORT_SYMBOL(netif_carrier_on);
+
+/**
+ *	netif_carrier_off - clear carrier
+ *	@dev: network device
+ *
+ * Device has detected loss of carrier.
+ */
+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_down_count);
+		linkwatch_fire_event(dev);
+	}
+}
+EXPORT_SYMBOL(netif_carrier_off);
+
+/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
+   under all circumstances. It is difficult to invent anything faster or
+   cheaper.
+ */
+
+static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
+			struct sk_buff **to_free)
+{
+	__qdisc_drop(skb, to_free);
+	return NET_XMIT_CN;
+}
+
+static struct sk_buff *noop_dequeue(struct Qdisc *qdisc)
+{
+	return NULL;
+}
+
+struct Qdisc_ops noop_qdisc_ops __read_mostly = {
+	.id		=	"noop",
+	.priv_size	=	0,
+	.enqueue	=	noop_enqueue,
+	.dequeue	=	noop_dequeue,
+	.peek		=	noop_dequeue,
+	.owner		=	THIS_MODULE,
+};
+
+static struct netdev_queue noop_netdev_queue = {
+	.qdisc		=	&noop_qdisc,
+	.qdisc_sleeping	=	&noop_qdisc,
+};
+
+struct Qdisc noop_qdisc = {
+	.enqueue	=	noop_enqueue,
+	.dequeue	=	noop_dequeue,
+	.flags		=	TCQ_F_BUILTIN,
+	.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,
+			struct netlink_ext_ack *extack)
+{
+	/* register_qdisc() assigns a default of noop_enqueue if unset,
+	 * but __dev_queue_xmit() treats noqueue only as such
+	 * if this is NULL - so clear it here. */
+	qdisc->enqueue = NULL;
+	return 0;
+}
+
+struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
+	.id		=	"noqueue",
+	.priv_size	=	0,
+	.init		=	noqueue_init,
+	.enqueue	=	noop_enqueue,
+	.dequeue	=	noop_dequeue,
+	.peek		=	noop_dequeue,
+	.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
+};
+
+/* 3-band FIFO queue: old style, but should be a bit faster than
+   generic prio+fifo combination.
+ */
+
+#define PFIFO_FAST_BANDS 3
+
+/*
+ * Private data for a pfifo_fast scheduler containing:
+ *	- rings for priority bands
+ */
+struct pfifo_fast_priv {
+	struct skb_array q[PFIFO_FAST_BANDS];
+};
+
+static inline struct skb_array *band2list(struct pfifo_fast_priv *priv,
+					  int band)
+{
+	return &priv->q[band];
+}
+
+static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
+			      struct sk_buff **to_free)
+{
+	int band = 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;
+
+	err = skb_array_produce(q, skb);
+
+	if (unlikely(err))
+		return qdisc_drop_cpu(skb, qdisc, to_free);
+
+	qdisc_qstats_atomic_qlen_inc(qdisc);
+	/* Note: skb can not be used after skb_array_produce(),
+	 * so we better not use qdisc_qstats_cpu_backlog_inc()
+	 */
+	this_cpu_add(qdisc->cpu_qstats->backlog, pkt_len);
+	return NET_XMIT_SUCCESS;
+}
+
+static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
+{
+	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
+	struct sk_buff *skb = NULL;
+	int band;
+
+	for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
+		struct skb_array *q = band2list(priv, band);
+
+		if (__skb_array_empty(q))
+			continue;
+
+		skb = __skb_array_consume(q);
+	}
+	if (likely(skb)) {
+		qdisc_qstats_cpu_backlog_dec(qdisc, skb);
+		qdisc_bstats_cpu_update(qdisc, skb);
+		qdisc_qstats_atomic_qlen_dec(qdisc);
+	}
+
+	return skb;
+}
+
+static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
+{
+	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
+	struct sk_buff *skb = NULL;
+	int band;
+
+	for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
+		struct skb_array *q = band2list(priv, band);
+
+		skb = __skb_array_peek(q);
+	}
+
+	return skb;
+}
+
+static void pfifo_fast_reset(struct Qdisc *qdisc)
+{
+	int i, band;
+	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
+
+	for (band = 0; band < PFIFO_FAST_BANDS; band++) {
+		struct skb_array *q = band2list(priv, band);
+		struct sk_buff *skb;
+
+		/* 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);
+	}
+
+	for_each_possible_cpu(i) {
+		struct gnet_stats_queue *q = per_cpu_ptr(qdisc->cpu_qstats, i);
+
+		q->backlog = 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);
+	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
+		goto nla_put_failure;
+	return skb->len;
+
+nla_put_failure:
+	return -1;
+}
+
+static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,
+			   struct netlink_ext_ack *extack)
+{
+	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++) {
+		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(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),
+	.enqueue	=	pfifo_fast_enqueue,
+	.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,
+			  struct netlink_ext_ack *extack)
+{
+	void *p;
+	struct Qdisc *sch;
+	unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size;
+	int err = -ENOBUFS;
+	struct net_device *dev;
+
+	if (!dev_queue) {
+		NL_SET_ERR_MSG(extack, "No device queue given");
+		err = -EINVAL;
+		goto errout;
+	}
+
+	dev = dev_queue->dev;
+	p = kzalloc_node(size, GFP_KERNEL,
+			 netdev_queue_numa_node_read(dev_queue));
+
+	if (!p)
+		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;
+	}
+	__skb_queue_head_init(&sch->gso_skb);
+	__skb_queue_head_init(&sch->skb_bad_txq);
+	qdisc_skb_head_init(&sch->q);
+	spin_lock_init(&sch->q.lock);
+
+	if (ops->static_flags & TCQ_F_CPUSTATS) {
+		sch->cpu_bstats =
+			netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
+		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,
+			  dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
+
+	/* seqlock has the same scope of busylock, for NOLOCK qdisc */
+	spin_lock_init(&sch->seqlock);
+	lockdep_set_class(&sch->busylock,
+			  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);
+	refcount_set(&sch->refcnt, 1);
+
+	return sch;
+errout1:
+	kfree(p);
+errout:
+	return ERR_PTR(err);
+}
+
+struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
+				const struct Qdisc_ops *ops,
+				unsigned int parentid,
+				struct netlink_ext_ack *extack)
+{
+	struct Qdisc *sch;
+
+	if (!try_module_get(ops->owner)) {
+		NL_SET_ERR_MSG(extack, "Failed to increase module reference counter");
+		return NULL;
+	}
+
+	sch = qdisc_alloc(dev_queue, ops, extack);
+	if (IS_ERR(sch)) {
+		module_put(ops->owner);
+		return NULL;
+	}
+	sch->parent = parentid;
+
+	if (!ops->init || ops->init(sch, NULL, extack) == 0)
+		return sch;
+
+	qdisc_put(sch);
+	return NULL;
+}
+EXPORT_SYMBOL(qdisc_create_dflt);
+
+/* Under qdisc_lock(qdisc) and BH! */
+
+void qdisc_reset(struct Qdisc *qdisc)
+{
+	const struct Qdisc_ops *ops = qdisc->ops;
+	struct sk_buff *skb, *tmp;
+
+	if (ops->reset)
+		ops->reset(qdisc);
+
+	skb_queue_walk_safe(&qdisc->gso_skb, skb, tmp) {
+		__skb_unlink(skb, &qdisc->gso_skb);
+		kfree_skb_list(skb);
+	}
+
+	skb_queue_walk_safe(&qdisc->skb_bad_txq, skb, tmp) {
+		__skb_unlink(skb, &qdisc->skb_bad_txq);
+		kfree_skb_list(skb);
+	}
+
+	qdisc->q.qlen = 0;
+	qdisc->qstats.backlog = 0;
+}
+EXPORT_SYMBOL(qdisc_reset);
+
+void qdisc_free(struct Qdisc *qdisc)
+{
+	if (qdisc_is_percpu_stats(qdisc)) {
+		free_percpu(qdisc->cpu_bstats);
+		free_percpu(qdisc->cpu_qstats);
+	}
+
+	kfree((char *) qdisc - qdisc->padded);
+}
+
+static void qdisc_free_cb(struct rcu_head *head)
+{
+	struct Qdisc *q = container_of(head, struct Qdisc, rcu);
+
+	qdisc_free(q);
+}
+
+static void qdisc_destroy(struct Qdisc *qdisc)
+{
+	const struct Qdisc_ops *ops;
+	struct sk_buff *skb, *tmp;
+
+	if (!qdisc)
+		return;
+	ops = qdisc->ops;
+
+#ifdef CONFIG_NET_SCHED
+	qdisc_hash_del(qdisc);
+
+	qdisc_put_stab(rtnl_dereference(qdisc->stab));
+#endif
+	gen_kill_estimator(&qdisc->rate_est);
+	if (ops->reset)
+		ops->reset(qdisc);
+	if (ops->destroy)
+		ops->destroy(qdisc);
+
+	module_put(ops->owner);
+	dev_put(qdisc_dev(qdisc));
+
+	skb_queue_walk_safe(&qdisc->gso_skb, skb, tmp) {
+		__skb_unlink(skb, &qdisc->gso_skb);
+		kfree_skb_list(skb);
+	}
+
+	skb_queue_walk_safe(&qdisc->skb_bad_txq, skb, tmp) {
+		__skb_unlink(skb, &qdisc->skb_bad_txq);
+		kfree_skb_list(skb);
+	}
+
+	call_rcu(&qdisc->rcu, qdisc_free_cb);
+}
+
+void qdisc_put(struct Qdisc *qdisc)
+{
+	if (qdisc->flags & TCQ_F_BUILTIN ||
+	    !refcount_dec_and_test(&qdisc->refcnt))
+		return;
+
+	qdisc_destroy(qdisc);
+}
+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;
+	spinlock_t *root_lock;
+
+	root_lock = qdisc_lock(oqdisc);
+	spin_lock_bh(root_lock);
+
+	/* ... and graft new one */
+	if (qdisc == NULL)
+		qdisc = &noop_qdisc;
+	dev_queue->qdisc_sleeping = qdisc;
+	rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
+
+	spin_unlock_bh(root_lock);
+
+	return oqdisc;
+}
+EXPORT_SYMBOL(dev_graft_qdisc);
+
+static void attach_one_default_qdisc(struct net_device *dev,
+				     struct netdev_queue *dev_queue,
+				     void *_unused)
+{
+	struct Qdisc *qdisc;
+	const struct Qdisc_ops *ops = default_qdisc_ops;
+
+	if (dev->priv_flags & IFF_NO_QUEUE)
+		ops = &noqueue_qdisc_ops;
+
+	qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT, NULL);
+	if (!qdisc) {
+		netdev_info(dev, "activation failed\n");
+		return;
+	}
+	if (!netif_is_multiqueue(dev))
+		qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
+	dev_queue->qdisc_sleeping = qdisc;
+}
+
+static void attach_default_qdiscs(struct net_device *dev)
+{
+	struct netdev_queue *txq;
+	struct Qdisc *qdisc;
+
+	txq = netdev_get_tx_queue(dev, 0);
+
+	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;
+		qdisc_refcount_inc(dev->qdisc);
+	} else {
+		qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT, NULL);
+		if (qdisc) {
+			dev->qdisc = qdisc;
+			qdisc->ops->attach(qdisc);
+		}
+	}
+#ifdef CONFIG_NET_SCHED
+	if (dev->qdisc != &noop_qdisc)
+		qdisc_hash_add(dev->qdisc, false);
+#endif
+}
+
+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;
+	int *need_watchdog_p = _need_watchdog;
+
+	if (!(new_qdisc->flags & TCQ_F_BUILTIN))
+		clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
+
+	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
+	if (need_watchdog_p) {
+		dev_queue->trans_start = 0;
+		*need_watchdog_p = 1;
+	}
+}
+
+void dev_activate(struct net_device *dev)
+{
+	int need_watchdog;
+
+	/* No queueing discipline is attached to device;
+	 * create default one for devices, which need queueing
+	 * and noqueue_qdisc for virtual interfaces
+	 */
+
+	if (dev->qdisc == &noop_qdisc)
+		attach_default_qdiscs(dev);
+
+	if (!netif_carrier_ok(dev))
+		/* Delay activation until next carrier-on event */
+		return;
+
+	need_watchdog = 0;
+	netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
+	if (dev_ingress_queue(dev))
+		transition_one_qdisc(dev, dev_ingress_queue(dev), NULL);
+
+	if (need_watchdog) {
+		netif_trans_update(dev);
+		dev_watchdog_up(dev);
+	}
+}
+EXPORT_SYMBOL(dev_activate);
+
+static void dev_deactivate_queue(struct net_device *dev,
+				 struct netdev_queue *dev_queue,
+				 void *_qdisc_default)
+{
+	struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc);
+	struct Qdisc *qdisc_default = _qdisc_default;
+
+	if (qdisc) {
+		if (!(qdisc->flags & TCQ_F_BUILTIN))
+			set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
+
+		rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
+	}
+}
+
+static void dev_reset_queue(struct net_device *dev,
+			    struct netdev_queue *dev_queue,
+			    void *_unused)
+{
+	struct Qdisc *qdisc;
+	bool nolock;
+
+	qdisc = 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));
+	if (nolock)
+		spin_unlock_bh(&qdisc->seqlock);
+}
+
+static bool some_qdisc_is_busy(struct net_device *dev)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *dev_queue;
+		spinlock_t *root_lock;
+		struct Qdisc *q;
+		int val;
+
+		dev_queue = netdev_get_tx_queue(dev, i);
+		q = dev_queue->qdisc_sleeping;
+
+		root_lock = qdisc_lock(q);
+		spin_lock_bh(root_lock);
+
+		val = (qdisc_is_running(q) ||
+		       test_bit(__QDISC_STATE_SCHED, &q->state));
+
+		spin_unlock_bh(root_lock);
+
+		if (val)
+			return true;
+	}
+	return false;
+}
+
+static void dev_qdisc_reset(struct net_device *dev,
+			    struct netdev_queue *dev_queue,
+			    void *none)
+{
+	struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
+
+	if (qdisc)
+		qdisc_reset(qdisc);
+}
+
+/**
+ * 	dev_deactivate_many - deactivate transmissions on several devices
+ * 	@head: list of devices to deactivate
+ *
+ *	This function returns only when all outstanding transmissions
+ *	have completed, unless all devices are in dismantle phase.
+ */
+void dev_deactivate_many(struct list_head *head)
+{
+	struct net_device *dev;
+
+	list_for_each_entry(dev, head, close_list) {
+		netdev_for_each_tx_queue(dev, dev_deactivate_queue,
+					 &noop_qdisc);
+		if (dev_ingress_queue(dev))
+			dev_deactivate_queue(dev, dev_ingress_queue(dev),
+					     &noop_qdisc);
+
+		dev_watchdog_down(dev);
+	}
+
+	/* Wait for outstanding qdisc-less dev_queue_xmit calls or
+	 * outstanding qdisc enqueuing calls.
+	 * This is avoided if all devices are in dismantle phase :
+	 * Caller will call synchronize_net() for us
+	 */
+	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();
+		/* The new qdisc is assigned at this point so we can safely
+		 * unwind stale skb lists and qdisc statistics
+		 */
+		netdev_for_each_tx_queue(dev, dev_qdisc_reset, NULL);
+		if (dev_ingress_queue(dev))
+			dev_qdisc_reset(dev, dev_ingress_queue(dev), NULL);
+	}
+}
+
+void dev_deactivate(struct net_device *dev)
+{
+	LIST_HEAD(single);
+
+	list_add(&dev->close_list, &single);
+	dev_deactivate_many(&single);
+	list_del(&single);
+}
+EXPORT_SYMBOL(dev_deactivate);
+
+static int qdisc_change_tx_queue_len(struct net_device *dev,
+				     struct netdev_queue *dev_queue)
+{
+	struct Qdisc *qdisc = 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 = dev->qdisc;
+
+	if (qdisc->ops->change_real_num_tx)
+		qdisc->ops->change_real_num_tx(qdisc, new_real_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)
+{
+	struct Qdisc *qdisc = _qdisc;
+
+	rcu_assign_pointer(dev_queue->qdisc, qdisc);
+	dev_queue->qdisc_sleeping = qdisc;
+}
+
+void dev_init_scheduler(struct net_device *dev)
+{
+	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);
+
+	timer_setup(&dev->watchdog_timer, dev_watchdog, 0);
+}
+
+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_put(qdisc);
+	}
+}
+
+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_put(dev->qdisc);
+	dev->qdisc = &noop_qdisc;
+
+	WARN_ON(timer_pending(&dev->watchdog_timer));
+}
+
+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.
+	 */
+	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++;
+		}
+	}
+}
+EXPORT_SYMBOL(psched_ratecfg_precompute);
+
+static void mini_qdisc_rcu_func(struct rcu_head *head)
+{
+}
+
+void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
+			  struct tcf_proto *tp_head)
+{
+	struct mini_Qdisc *miniq_old = rtnl_dereference(*miniqp->p_miniq);
+	struct mini_Qdisc *miniq;
+
+	if (!tp_head) {
+		RCU_INIT_POINTER(*miniqp->p_miniq, NULL);
+		/* Wait for flying RCU callback before it is freed. */
+		rcu_barrier_bh();
+		return;
+	}
+
+	miniq = !miniq_old || miniq_old == &miniqp->miniq2 ?
+		&miniqp->miniq1 : &miniqp->miniq2;
+
+	/* We need to make sure that readers won't see the miniq
+	 * we are about to modify. So wait until previous call_rcu_bh callback
+	 * is done.
+	 */
+	rcu_barrier_bh();
+	miniq->filter_list = tp_head;
+	rcu_assign_pointer(*miniqp->p_miniq, miniq);
+
+	if (miniq_old)
+		/* This is counterpart of the rcu barriers above. We need to
+		 * block potential new user of miniq_old until all readers
+		 * are not seeing it.
+		 */
+		call_rcu_bh(&miniq_old->rcu, mini_qdisc_rcu_func);
+}
+EXPORT_SYMBOL(mini_qdisc_pair_swap);
+
+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->p_miniq = p_miniq;
+}
+EXPORT_SYMBOL(mini_qdisc_pair_init);