Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 675 insertions, 0 deletions

diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
new file mode 100644
index 000000000..64d7f876d
--- /dev/null
+++ b/net/sched/sch_mqprio.c
@@ -0,0 +1,675 @@
+/*
+ * net/sched/sch_mqprio.c
+ *
+ * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/sch_generic.h>
+#include <net/pkt_cls.h>
+
+struct mqprio_sched {
+	struct Qdisc		**qdiscs;
+	u16 mode;
+	u16 shaper;
+	int hw_offload;
+	u32 flags;
+	u64 min_rate[TC_QOPT_MAX_QUEUE];
+	u64 max_rate[TC_QOPT_MAX_QUEUE];
+};
+
+static void mqprio_destroy(struct Qdisc *sch)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct mqprio_sched *priv = qdisc_priv(sch);
+	unsigned int ntx;
+
+	if (priv->qdiscs) {
+		for (ntx = 0;
+		     ntx < dev->num_tx_queues && priv->qdiscs[ntx];
+		     ntx++)
+			qdisc_put(priv->qdiscs[ntx]);
+		kfree(priv->qdiscs);
+	}
+
+	if (priv->hw_offload && dev->netdev_ops->ndo_setup_tc) {
+		struct tc_mqprio_qopt_offload mqprio = { { 0 } };
+
+		switch (priv->mode) {
+		case TC_MQPRIO_MODE_DCB:
+		case TC_MQPRIO_MODE_CHANNEL:
+			dev->netdev_ops->ndo_setup_tc(dev,
+						      TC_SETUP_QDISC_MQPRIO,
+						      &mqprio);
+			break;
+		default:
+			return;
+		}
+	} else {
+		netdev_set_num_tc(dev, 0);
+	}
+}
+
+static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
+{
+	int i, j;
+
+	/* Verify num_tc is not out of max range */
+	if (qopt->num_tc > TC_MAX_QUEUE)
+		return -EINVAL;
+
+	/* Verify priority mapping uses valid tcs */
+	for (i = 0; i < TC_BITMASK + 1; i++) {
+		if (qopt->prio_tc_map[i] >= qopt->num_tc)
+			return -EINVAL;
+	}
+
+	/* Limit qopt->hw to maximum supported offload value.  Drivers have
+	 * the option of overriding this later if they don't support the a
+	 * given offload type.
+	 */
+	if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX)
+		qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX;
+
+	/* If hardware offload is requested we will leave it to the device
+	 * to either populate the queue counts itself or to validate the
+	 * provided queue counts.  If ndo_setup_tc is not present then
+	 * hardware doesn't support offload and we should return an error.
+	 */
+	if (qopt->hw)
+		return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL;
+
+	for (i = 0; i < qopt->num_tc; i++) {
+		unsigned int last = qopt->offset[i] + qopt->count[i];
+
+		/* Verify the queue count is in tx range being equal to the
+		 * real_num_tx_queues indicates the last queue is in use.
+		 */
+		if (qopt->offset[i] >= dev->real_num_tx_queues ||
+		    !qopt->count[i] ||
+		    last > dev->real_num_tx_queues)
+			return -EINVAL;
+
+		/* Verify that the offset and counts do not overlap */
+		for (j = i + 1; j < qopt->num_tc; j++) {
+			if (last > qopt->offset[j])
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static const struct nla_policy mqprio_policy[TCA_MQPRIO_MAX + 1] = {
+	[TCA_MQPRIO_MODE]	= { .len = sizeof(u16) },
+	[TCA_MQPRIO_SHAPER]	= { .len = sizeof(u16) },
+	[TCA_MQPRIO_MIN_RATE64]	= { .type = NLA_NESTED },
+	[TCA_MQPRIO_MAX_RATE64]	= { .type = NLA_NESTED },
+};
+
+static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
+		      const struct nla_policy *policy, int len)
+{
+	int nested_len = nla_len(nla) - NLA_ALIGN(len);
+
+	if (nested_len >= nla_attr_size(0))
+		return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
+				 nested_len, policy, NULL);
+
+	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
+	return 0;
+}
+
+static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
+		       struct netlink_ext_ack *extack)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct mqprio_sched *priv = qdisc_priv(sch);
+	struct netdev_queue *dev_queue;
+	struct Qdisc *qdisc;
+	int i, err = -EOPNOTSUPP;
+	struct tc_mqprio_qopt *qopt = NULL;
+	struct nlattr *tb[TCA_MQPRIO_MAX + 1];
+	struct nlattr *attr;
+	int rem;
+	int len;
+
+	BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
+	BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
+
+	if (sch->parent != TC_H_ROOT)
+		return -EOPNOTSUPP;
+
+	if (!netif_is_multiqueue(dev))
+		return -EOPNOTSUPP;
+
+	/* make certain can allocate enough classids to handle queues */
+	if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
+		return -ENOMEM;
+
+	if (!opt || nla_len(opt) < sizeof(*qopt))
+		return -EINVAL;
+
+	qopt = nla_data(opt);
+	if (mqprio_parse_opt(dev, qopt))
+		return -EINVAL;
+
+	len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
+	if (len > 0) {
+		err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
+				 sizeof(*qopt));
+		if (err < 0)
+			return err;
+
+		if (!qopt->hw)
+			return -EINVAL;
+
+		if (tb[TCA_MQPRIO_MODE]) {
+			priv->flags |= TC_MQPRIO_F_MODE;
+			priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
+		}
+
+		if (tb[TCA_MQPRIO_SHAPER]) {
+			priv->flags |= TC_MQPRIO_F_SHAPER;
+			priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
+		}
+
+		if (tb[TCA_MQPRIO_MIN_RATE64]) {
+			if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
+				return -EINVAL;
+			i = 0;
+			nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
+					    rem) {
+				if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64)
+					return -EINVAL;
+				if (i >= qopt->num_tc)
+					break;
+				priv->min_rate[i] = *(u64 *)nla_data(attr);
+				i++;
+			}
+			priv->flags |= TC_MQPRIO_F_MIN_RATE;
+		}
+
+		if (tb[TCA_MQPRIO_MAX_RATE64]) {
+			if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
+				return -EINVAL;
+			i = 0;
+			nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
+					    rem) {
+				if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64)
+					return -EINVAL;
+				if (i >= qopt->num_tc)
+					break;
+				priv->max_rate[i] = *(u64 *)nla_data(attr);
+				i++;
+			}
+			priv->flags |= TC_MQPRIO_F_MAX_RATE;
+		}
+	}
+
+	/* pre-allocate qdisc, attachment can't fail */
+	priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
+			       GFP_KERNEL);
+	if (!priv->qdiscs)
+		return -ENOMEM;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		dev_queue = netdev_get_tx_queue(dev, i);
+		qdisc = qdisc_create_dflt(dev_queue,
+					  get_default_qdisc_ops(dev, i),
+					  TC_H_MAKE(TC_H_MAJ(sch->handle),
+						    TC_H_MIN(i + 1)), extack);
+		if (!qdisc)
+			return -ENOMEM;
+
+		priv->qdiscs[i] = qdisc;
+		qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
+	}
+
+	/* If the mqprio options indicate that hardware should own
+	 * the queue mapping then run ndo_setup_tc otherwise use the
+	 * supplied and verified mapping
+	 */
+	if (qopt->hw) {
+		struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
+
+		switch (priv->mode) {
+		case TC_MQPRIO_MODE_DCB:
+			if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
+				return -EINVAL;
+			break;
+		case TC_MQPRIO_MODE_CHANNEL:
+			mqprio.flags = priv->flags;
+			if (priv->flags & TC_MQPRIO_F_MODE)
+				mqprio.mode = priv->mode;
+			if (priv->flags & TC_MQPRIO_F_SHAPER)
+				mqprio.shaper = priv->shaper;
+			if (priv->flags & TC_MQPRIO_F_MIN_RATE)
+				for (i = 0; i < mqprio.qopt.num_tc; i++)
+					mqprio.min_rate[i] = priv->min_rate[i];
+			if (priv->flags & TC_MQPRIO_F_MAX_RATE)
+				for (i = 0; i < mqprio.qopt.num_tc; i++)
+					mqprio.max_rate[i] = priv->max_rate[i];
+			break;
+		default:
+			return -EINVAL;
+		}
+		err = dev->netdev_ops->ndo_setup_tc(dev,
+						    TC_SETUP_QDISC_MQPRIO,
+						    &mqprio);
+		if (err)
+			return err;
+
+		priv->hw_offload = mqprio.qopt.hw;
+	} else {
+		netdev_set_num_tc(dev, qopt->num_tc);
+		for (i = 0; i < qopt->num_tc; i++)
+			netdev_set_tc_queue(dev, i,
+					    qopt->count[i], qopt->offset[i]);
+	}
+
+	/* Always use supplied priority mappings */
+	for (i = 0; i < TC_BITMASK + 1; i++)
+		netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
+
+	sch->flags |= TCQ_F_MQROOT;
+	return 0;
+}
+
+static void mqprio_attach(struct Qdisc *sch)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct mqprio_sched *priv = qdisc_priv(sch);
+	struct Qdisc *qdisc, *old;
+	unsigned int ntx;
+
+	/* Attach underlying qdisc */
+	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
+		qdisc = priv->qdiscs[ntx];
+		old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
+		if (old)
+			qdisc_put(old);
+		if (ntx < dev->real_num_tx_queues)
+			qdisc_hash_add(qdisc, false);
+	}
+	kfree(priv->qdiscs);
+	priv->qdiscs = NULL;
+}
+
+static void mqprio_change_real_num_tx(struct Qdisc *sch,
+				      unsigned int new_real_tx)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct Qdisc *qdisc;
+	unsigned int i;
+
+	for (i = new_real_tx; i < dev->real_num_tx_queues; i++) {
+		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
+		/* Only update the default qdiscs we created,
+		 * qdiscs with handles are always hashed.
+		 */
+		if (qdisc != &noop_qdisc && !qdisc->handle)
+			qdisc_hash_del(qdisc);
+	}
+	for (i = dev->real_num_tx_queues; i < new_real_tx; i++) {
+		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
+		if (qdisc != &noop_qdisc && !qdisc->handle)
+			qdisc_hash_add(qdisc, false);
+	}
+}
+
+static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
+					     unsigned long cl)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	unsigned long ntx = cl - 1;
+
+	if (ntx >= dev->num_tx_queues)
+		return NULL;
+	return netdev_get_tx_queue(dev, ntx);
+}
+
+static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
+			struct Qdisc **old, struct netlink_ext_ack *extack)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+
+	if (!dev_queue)
+		return -EINVAL;
+
+	if (dev->flags & IFF_UP)
+		dev_deactivate(dev);
+
+	*old = dev_graft_qdisc(dev_queue, new);
+
+	if (new)
+		new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
+
+	if (dev->flags & IFF_UP)
+		dev_activate(dev);
+
+	return 0;
+}
+
+static int dump_rates(struct mqprio_sched *priv,
+		      struct tc_mqprio_qopt *opt, struct sk_buff *skb)
+{
+	struct nlattr *nest;
+	int i;
+
+	if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
+		nest = nla_nest_start(skb, TCA_MQPRIO_MIN_RATE64);
+		if (!nest)
+			goto nla_put_failure;
+
+		for (i = 0; i < opt->num_tc; i++) {
+			if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
+				    sizeof(priv->min_rate[i]),
+				    &priv->min_rate[i]))
+				goto nla_put_failure;
+		}
+		nla_nest_end(skb, nest);
+	}
+
+	if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
+		nest = nla_nest_start(skb, TCA_MQPRIO_MAX_RATE64);
+		if (!nest)
+			goto nla_put_failure;
+
+		for (i = 0; i < opt->num_tc; i++) {
+			if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
+				    sizeof(priv->max_rate[i]),
+				    &priv->max_rate[i]))
+				goto nla_put_failure;
+		}
+		nla_nest_end(skb, nest);
+	}
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	return -1;
+}
+
+static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct mqprio_sched *priv = qdisc_priv(sch);
+	struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
+	struct tc_mqprio_qopt opt = { 0 };
+	struct Qdisc *qdisc;
+	unsigned int ntx, tc;
+
+	sch->q.qlen = 0;
+	memset(&sch->bstats, 0, sizeof(sch->bstats));
+	memset(&sch->qstats, 0, sizeof(sch->qstats));
+
+	/* MQ supports lockless qdiscs. However, statistics accounting needs
+	 * to account for all, none, or a mix of locked and unlocked child
+	 * qdiscs. Percpu stats are added to counters in-band and locking
+	 * qdisc totals are added at end.
+	 */
+	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
+		qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
+		spin_lock_bh(qdisc_lock(qdisc));
+
+		if (qdisc_is_percpu_stats(qdisc)) {
+			__u32 qlen = qdisc_qlen_sum(qdisc);
+
+			__gnet_stats_copy_basic(NULL, &sch->bstats,
+						qdisc->cpu_bstats,
+						&qdisc->bstats);
+			__gnet_stats_copy_queue(&sch->qstats,
+						qdisc->cpu_qstats,
+						&qdisc->qstats, qlen);
+			sch->q.qlen		+= qlen;
+		} else {
+			sch->q.qlen		+= qdisc->q.qlen;
+			sch->bstats.bytes	+= qdisc->bstats.bytes;
+			sch->bstats.packets	+= qdisc->bstats.packets;
+			sch->qstats.backlog	+= qdisc->qstats.backlog;
+			sch->qstats.drops	+= qdisc->qstats.drops;
+			sch->qstats.requeues	+= qdisc->qstats.requeues;
+			sch->qstats.overlimits	+= qdisc->qstats.overlimits;
+		}
+
+		spin_unlock_bh(qdisc_lock(qdisc));
+	}
+
+	opt.num_tc = netdev_get_num_tc(dev);
+	memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
+	opt.hw = priv->hw_offload;
+
+	for (tc = 0; tc < netdev_get_num_tc(dev); tc++) {
+		opt.count[tc] = dev->tc_to_txq[tc].count;
+		opt.offset[tc] = dev->tc_to_txq[tc].offset;
+	}
+
+	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	if ((priv->flags & TC_MQPRIO_F_MODE) &&
+	    nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
+		goto nla_put_failure;
+
+	if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
+	    nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
+		goto nla_put_failure;
+
+	if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
+	     priv->flags & TC_MQPRIO_F_MAX_RATE) &&
+	    (dump_rates(priv, &opt, skb) != 0))
+		goto nla_put_failure;
+
+	return nla_nest_end(skb, nla);
+nla_put_failure:
+	nlmsg_trim(skb, nla);
+	return -1;
+}
+
+static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
+{
+	struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+
+	if (!dev_queue)
+		return NULL;
+
+	return dev_queue->qdisc_sleeping;
+}
+
+static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	unsigned int ntx = TC_H_MIN(classid);
+
+	/* There are essentially two regions here that have valid classid
+	 * values. The first region will have a classid value of 1 through
+	 * num_tx_queues. All of these are backed by actual Qdiscs.
+	 */
+	if (ntx < TC_H_MIN_PRIORITY)
+		return (ntx <= dev->num_tx_queues) ? ntx : 0;
+
+	/* The second region represents the hardware traffic classes. These
+	 * are represented by classid values of TC_H_MIN_PRIORITY through
+	 * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
+	 */
+	return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
+}
+
+static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
+			 struct sk_buff *skb, struct tcmsg *tcm)
+{
+	if (cl < TC_H_MIN_PRIORITY) {
+		struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+		struct net_device *dev = qdisc_dev(sch);
+		int tc = netdev_txq_to_tc(dev, cl - 1);
+
+		tcm->tcm_parent = (tc < 0) ? 0 :
+			TC_H_MAKE(TC_H_MAJ(sch->handle),
+				  TC_H_MIN(tc + TC_H_MIN_PRIORITY));
+		tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
+	} else {
+		tcm->tcm_parent = TC_H_ROOT;
+		tcm->tcm_info = 0;
+	}
+	tcm->tcm_handle |= TC_H_MIN(cl);
+	return 0;
+}
+
+static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+				   struct gnet_dump *d)
+	__releases(d->lock)
+	__acquires(d->lock)
+{
+	if (cl >= TC_H_MIN_PRIORITY) {
+		int i;
+		__u32 qlen = 0;
+		struct gnet_stats_queue qstats = {0};
+		struct gnet_stats_basic_packed bstats = {0};
+		struct net_device *dev = qdisc_dev(sch);
+		struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
+
+		/* Drop lock here it will be reclaimed before touching
+		 * statistics this is required because the d->lock we
+		 * hold here is the look on dev_queue->qdisc_sleeping
+		 * also acquired below.
+		 */
+		if (d->lock)
+			spin_unlock_bh(d->lock);
+
+		for (i = tc.offset; i < tc.offset + tc.count; i++) {
+			struct netdev_queue *q = netdev_get_tx_queue(dev, i);
+			struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
+
+			spin_lock_bh(qdisc_lock(qdisc));
+
+			if (qdisc_is_percpu_stats(qdisc)) {
+				qlen = qdisc_qlen_sum(qdisc);
+
+				__gnet_stats_copy_basic(NULL, &bstats,
+							qdisc->cpu_bstats,
+							&qdisc->bstats);
+				__gnet_stats_copy_queue(&qstats,
+							qdisc->cpu_qstats,
+							&qdisc->qstats,
+							qlen);
+			} else {
+				qlen		+= qdisc->q.qlen;
+				bstats.bytes	+= qdisc->bstats.bytes;
+				bstats.packets	+= qdisc->bstats.packets;
+				qstats.backlog	+= qdisc->qstats.backlog;
+				qstats.drops	+= qdisc->qstats.drops;
+				qstats.requeues	+= qdisc->qstats.requeues;
+				qstats.overlimits += qdisc->qstats.overlimits;
+			}
+			spin_unlock_bh(qdisc_lock(qdisc));
+		}
+
+		/* Reclaim root sleeping lock before completing stats */
+		if (d->lock)
+			spin_lock_bh(d->lock);
+		if (gnet_stats_copy_basic(NULL, d, NULL, &bstats) < 0 ||
+		    gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
+			return -1;
+	} else {
+		struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
+
+		sch = dev_queue->qdisc_sleeping;
+		if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d,
+					  sch->cpu_bstats, &sch->bstats) < 0 ||
+		    gnet_stats_copy_queue(d, NULL,
+					  &sch->qstats, sch->q.qlen) < 0)
+			return -1;
+	}
+	return 0;
+}
+
+static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	unsigned long ntx;
+
+	if (arg->stop)
+		return;
+
+	/* Walk hierarchy with a virtual class per tc */
+	arg->count = arg->skip;
+	for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
+		if (arg->fn(sch, ntx + TC_H_MIN_PRIORITY, arg) < 0) {
+			arg->stop = 1;
+			return;
+		}
+		arg->count++;
+	}
+
+	/* Pad the values and skip over unused traffic classes */
+	if (ntx < TC_MAX_QUEUE) {
+		arg->count = TC_MAX_QUEUE;
+		ntx = TC_MAX_QUEUE;
+	}
+
+	/* Reset offset, sort out remaining per-queue qdiscs */
+	for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
+		if (arg->fn(sch, ntx + 1, arg) < 0) {
+			arg->stop = 1;
+			return;
+		}
+		arg->count++;
+	}
+}
+
+static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
+						struct tcmsg *tcm)
+{
+	return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
+}
+
+static const struct Qdisc_class_ops mqprio_class_ops = {
+	.graft		= mqprio_graft,
+	.leaf		= mqprio_leaf,
+	.find		= mqprio_find,
+	.walk		= mqprio_walk,
+	.dump		= mqprio_dump_class,
+	.dump_stats	= mqprio_dump_class_stats,
+	.select_queue	= mqprio_select_queue,
+};
+
+static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
+	.cl_ops		= &mqprio_class_ops,
+	.id		= "mqprio",
+	.priv_size	= sizeof(struct mqprio_sched),
+	.init		= mqprio_init,
+	.destroy	= mqprio_destroy,
+	.attach		= mqprio_attach,
+	.change_real_num_tx = mqprio_change_real_num_tx,
+	.dump		= mqprio_dump,
+	.owner		= THIS_MODULE,
+};
+
+static int __init mqprio_module_init(void)
+{
+	return register_qdisc(&mqprio_qdisc_ops);
+}
+
+static void __exit mqprio_module_exit(void)
+{
+	unregister_qdisc(&mqprio_qdisc_ops);
+}
+
+module_init(mqprio_module_init);
+module_exit(mqprio_module_exit);
+
+MODULE_LICENSE("GPL");