[RFC,04/10] net: sch_ets: Add a new Qdisc

diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index 5011259b8f67..d7f1bd8fd136 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -1181,4 +1181,33 @@  enum {
 
 #define TCA_TAPRIO_ATTR_MAX (__TCA_TAPRIO_ATTR_MAX - 1)
 
+/* ETS */
+
+#define TCQ_ETS_MAX_BANDS 16
+
+enum {
+	TCA_ETS_UNSPEC,
+	TCA_ETS_BANDS,	/* u8 */
+	TCA_ETS_STRICT,	/* u8 */
+	TCA_ETS_QUANTA,	/* nested TCA_ETS_BAND_QUANTUM */
+	TCA_ETS_PRIOMAP,	/* nested TCA_ETS_PMAP_BAND */
+	__TCA_ETS_MAX,
+};
+
+#define TCA_ETS_MAX (__TCA_ETS_MAX - 1)
+
+enum {
+	TCA_ETS_BAND_UNSPEC,
+	TCA_ETS_BAND_QUANTUM,	/* u32 */
+	__TCA_ETS_BAND_MAX,
+};
+#define TCA_ETS_BAND_MAX (__TCA_ETS_BAND_MAX - 1)
+
+enum {
+	TCA_ETS_PMAP_UNSPEC,
+	TCA_ETS_PMAP_BAND,	/* u8 */
+	__TCA_ETS_PMAP_MAX,
+};
+#define TCA_ETS_PMAP_MAX (__TCA_ETS_PMAP_MAX - 1)
+
 #endif
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 2985509147a2..192878a1095e 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -409,6 +409,17 @@  config NET_SCH_PLUG
 	  To compile this code as a module, choose M here: the
 	  module will be called sch_plug.
 
+config NET_SCH_ETS
+	tristate "Enhanced transmission selection scheduler (ETS)"
+	help
+	  Say Y here if you want to use the 802.1Qaz-compliant "enhanced
+	  transmission selection" packet scheduling algorithm.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called sch_drr.
+
+	  If unsure, say N.
+
 menuconfig NET_SCH_DEFAULT
 	bool "Allow override default queue discipline"
 	---help---
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 415d1e1f237e..bc8856b865ff 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -48,6 +48,7 @@  obj-$(CONFIG_NET_SCH_ATM)	+= sch_atm.o
 obj-$(CONFIG_NET_SCH_NETEM)	+= sch_netem.o
 obj-$(CONFIG_NET_SCH_DRR)	+= sch_drr.o
 obj-$(CONFIG_NET_SCH_PLUG)	+= sch_plug.o
+obj-$(CONFIG_NET_SCH_ETS)	+= sch_ets.o
 obj-$(CONFIG_NET_SCH_MQPRIO)	+= sch_mqprio.o
 obj-$(CONFIG_NET_SCH_SKBPRIO)	+= sch_skbprio.o
 obj-$(CONFIG_NET_SCH_CHOKE)	+= sch_choke.o
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
new file mode 100644
index 000000000000..6a1751564c4b
--- /dev/null
+++ b/net/sched/sch_ets.c
@@ -0,0 +1,701 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * net/sched/sch_ets.c         Enhanced Transmission Selection scheduler
+ */
+
+#include <linux/module.h>
+#include <net/gen_stats.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/sch_generic.h>
+
+struct ets_class {
+	struct list_head alist; /* In struct ets_sched.active. */
+	struct Qdisc *qdisc;
+	u32 quantum;
+	u32 deficit;
+	struct gnet_stats_basic_packed bstats;
+	struct gnet_stats_queue qstats;
+};
+
+struct ets_sched {
+	struct list_head active;
+	struct tcf_proto __rcu *filter_list;
+	struct tcf_block *block;
+	unsigned int nbands;
+	unsigned int nstrict;
+	u8 prio2band[TC_PRIO_MAX + 1];
+	struct ets_class classes[TCQ_ETS_MAX_BANDS];
+};
+
+static const struct nla_policy ets_policy[TCA_ETS_MAX + 1] = {
+	[TCA_ETS_BANDS] = { .type = NLA_U8 },
+	[TCA_ETS_STRICT] = { .type = NLA_U8 },
+	[TCA_ETS_QUANTA] = { .type = NLA_NESTED },
+	[TCA_ETS_PRIOMAP] = { .type = NLA_NESTED },
+};
+
+static const struct nla_policy ets_pmap_policy[TCA_ETS_PMAP_MAX + 1] = {
+	[TCA_ETS_PMAP_BAND] = { .type = NLA_U8 },
+};
+
+static const struct nla_policy ets_band_policy[TCA_ETS_BAND_MAX + 1] = {
+	[TCA_ETS_BAND_QUANTUM]	= { .type = NLA_U32 },
+};
+
+static int ets_quantum_parse(struct Qdisc *sch, const struct nlattr *attr,
+			     unsigned int *pquantum,
+			     struct netlink_ext_ack *extack)
+{
+	unsigned int quantum;
+
+	if (attr) {
+		quantum = nla_get_u32(attr);
+		if (!quantum) {
+			NL_SET_ERR_MSG(extack, "ETS quantum cannot be zero");
+			return -EINVAL;
+		}
+	} else {
+		quantum = psched_mtu(qdisc_dev(sch));
+	}
+
+	*pquantum = quantum;
+	return 0;
+}
+
+static struct ets_class *
+ets_class_from_arg(struct Qdisc *sch, unsigned long arg)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+
+	return &q->classes[arg - 1];
+}
+
+static u32 ets_class_id(struct Qdisc *sch, struct ets_class *cl)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	int band = cl - q->classes;
+
+	return TC_H_MAKE(sch->handle, band + 1);
+}
+
+static bool ets_class_is_strict(struct ets_sched *q, struct ets_class *cl)
+{
+	unsigned int band = cl - q->classes;
+
+	return band < q->nstrict;
+}
+
+static int ets_class_change(struct Qdisc *sch, u32 classid, u32 parentid,
+			    struct nlattr **tca, unsigned long *arg,
+			    struct netlink_ext_ack *extack)
+{
+	struct ets_class *cl = ets_class_from_arg(sch, *arg);
+	struct ets_sched *q = qdisc_priv(sch);
+	struct nlattr *opt = tca[TCA_OPTIONS];
+	struct nlattr *tb[TCA_ETS_MAX + 1];
+	unsigned int quantum;
+	int err;
+
+	/* Classes can be added and removed only through Qdisc_ops.change
+	 * interface.
+	 */
+	if (!cl) {
+		NL_SET_ERR_MSG(extack, "Fine-grained class addition and removal is not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (!opt) {
+		NL_SET_ERR_MSG(extack, "ETS options are required for this operation");
+		return -EINVAL;
+	}
+
+	err = nla_parse_nested(tb, TCA_ETS_BAND_MAX, opt, ets_band_policy,
+			       extack);
+	if (err < 0)
+		return err;
+
+	if (!tb[TCA_ETS_BAND_QUANTUM])
+		/* Nothing to configure. */
+		return 0;
+
+	if (ets_class_is_strict(q, cl)) {
+		NL_SET_ERR_MSG(extack, "Strict bands do not have a configurable quantum");
+		return -EINVAL;
+	}
+
+	err = ets_quantum_parse(sch, tb[TCA_ETS_BAND_QUANTUM], &quantum,
+				extack);
+	if (err)
+		return err;
+
+	sch_tree_lock(sch);
+	cl->quantum = quantum;
+	sch_tree_unlock(sch);
+	return 0;
+}
+
+static int ets_class_graft(struct Qdisc *sch, unsigned long arg,
+			   struct Qdisc *new, struct Qdisc **old,
+			   struct netlink_ext_ack *extack)
+{
+	struct ets_class *cl = ets_class_from_arg(sch, arg);
+
+	if (!new) {
+		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+					ets_class_id(sch, cl), NULL);
+		if (!new)
+			new = &noop_qdisc;
+	}
+
+	*old = qdisc_replace(sch, new, &cl->qdisc);
+	return 0;
+}
+
+static struct Qdisc *ets_class_leaf(struct Qdisc *sch, unsigned long arg)
+{
+	struct ets_class *cl = ets_class_from_arg(sch, arg);
+
+	return cl->qdisc;
+}
+
+static unsigned long ets_class_find(struct Qdisc *sch, u32 classid)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	unsigned long band = TC_H_MIN(classid);
+
+	if (band - 1 >= q->nbands)
+		return 0;
+	return band;
+}
+
+static void ets_class_qlen_notify(struct Qdisc *sch, unsigned long arg)
+{
+	struct ets_class *cl = ets_class_from_arg(sch, arg);
+	struct ets_sched *q = qdisc_priv(sch);
+
+	if (!ets_class_is_strict(q, cl))
+		list_del(&cl->alist);
+}
+
+static int ets_class_dump(struct Qdisc *sch, unsigned long arg,
+			  struct sk_buff *skb, struct tcmsg *tcm)
+{
+	struct ets_class *cl = ets_class_from_arg(sch, arg);
+	struct ets_sched *q = qdisc_priv(sch);
+	struct nlattr *nest;
+
+	tcm->tcm_parent = TC_H_ROOT;
+	tcm->tcm_handle = ets_class_id(sch, cl);
+	tcm->tcm_info = cl->qdisc->handle;
+
+	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
+	if (!nest)
+		goto nla_put_failure;
+	if (!ets_class_is_strict(q, cl)) {
+		if (nla_put_u32(skb, TCA_ETS_BAND_QUANTUM, cl->quantum))
+			goto nla_put_failure;
+	}
+	return nla_nest_end(skb, nest);
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
+static int ets_class_dump_stats(struct Qdisc *sch, unsigned long arg,
+				struct gnet_dump *d)
+{
+	struct ets_class *cl = ets_class_from_arg(sch, arg);
+	struct Qdisc *cl_q = cl->qdisc;
+
+	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
+				  d, NULL, &cl_q->bstats) < 0 ||
+	    qdisc_qstats_copy(d, cl_q) < 0)
+		return -1;
+
+	return 0;
+}
+
+static void ets_qdisc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	int i;
+
+	if (arg->stop)
+		return;
+
+	for (i = 0; i < q->nbands; i++) {
+		if (arg->count < arg->skip) {
+			arg->count++;
+			continue;
+		}
+		if (arg->fn(sch, i + 1, arg) < 0) {
+			arg->stop = 1;
+			break;
+		}
+		arg->count++;
+	}
+}
+
+static struct tcf_block *
+ets_qdisc_tcf_block(struct Qdisc *sch, unsigned long cl,
+		    struct netlink_ext_ack *extack)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+
+	if (cl) {
+		NL_SET_ERR_MSG(extack, "ETS classid must be zero");
+		return NULL;
+	}
+
+	return q->block;
+}
+
+static unsigned long ets_qdisc_bind_tcf(struct Qdisc *sch, unsigned long parent,
+					u32 classid)
+{
+	return ets_class_find(sch, classid);
+}
+
+static void ets_qdisc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
+{
+}
+
+static struct ets_class *ets_classify(struct sk_buff *skb, struct Qdisc *sch,
+				      int *qerr)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	u32 band = skb->priority;
+	struct tcf_result res;
+	struct tcf_proto *fl;
+	int err;
+
+	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+	if (TC_H_MAJ(skb->priority) != sch->handle) {
+		fl = rcu_dereference_bh(q->filter_list);
+		err = tcf_classify(skb, fl, &res, false);
+#ifdef CONFIG_NET_CLS_ACT
+		switch (err) {
+		case TC_ACT_STOLEN:
+		case TC_ACT_QUEUED:
+		case TC_ACT_TRAP:
+			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+			/* fall through */
+		case TC_ACT_SHOT:
+			return NULL;
+		}
+#endif
+		if (!fl || err < 0) {
+			if (TC_H_MAJ(band))
+				band = 0;
+			return &q->classes[q->prio2band[band & TC_PRIO_MAX]];
+		}
+		band = res.classid;
+	}
+	band = TC_H_MIN(band) - 1;
+	if (band >= q->nbands)
+		return &q->classes[q->prio2band[0]];
+	return &q->classes[band];
+}
+
+static int ets_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+			     struct sk_buff **to_free)
+{
+	unsigned int len = qdisc_pkt_len(skb);
+	struct ets_sched *q = qdisc_priv(sch);
+	struct ets_class *cl;
+	int err = 0;
+	bool first;
+
+	cl = ets_classify(skb, sch, &err);
+	if (!cl) {
+		if (err & __NET_XMIT_BYPASS)
+			qdisc_qstats_drop(sch);
+		__qdisc_drop(skb, to_free);
+		return err;
+	}
+
+	first = !cl->qdisc->q.qlen;
+	err = qdisc_enqueue(skb, cl->qdisc, to_free);
+	if (unlikely(err != NET_XMIT_SUCCESS)) {
+		if (net_xmit_drop_count(err)) {
+			cl->qstats.drops++;
+			qdisc_qstats_drop(sch);
+		}
+		return err;
+	}
+
+	if (first && !ets_class_is_strict(q, cl)) {
+		list_add_tail(&cl->alist, &q->active);
+		cl->deficit = cl->quantum;
+	}
+
+	sch->qstats.backlog += len;
+	sch->q.qlen++;
+	return err;
+}
+
+static struct sk_buff *
+ets_qdisc_dequeue_skb(struct Qdisc *sch, struct sk_buff *skb)
+{
+	qdisc_bstats_update(sch, skb);
+	qdisc_qstats_backlog_dec(sch, skb);
+	sch->q.qlen--;
+	return skb;
+}
+
+static struct sk_buff *ets_qdisc_dequeue(struct Qdisc *sch)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	struct ets_class *cl;
+	struct sk_buff *skb;
+	unsigned int band;
+	unsigned int len;
+
+	while (1) {
+		for (band = 0; band < q->nstrict; band++) {
+			cl = &q->classes[band];
+			skb = qdisc_dequeue_peeked(cl->qdisc);
+			if (skb)
+				return ets_qdisc_dequeue_skb(sch, skb);
+		}
+
+		if (list_empty(&q->active))
+			goto out;
+
+		cl = list_first_entry(&q->active, struct ets_class, alist);
+		skb = cl->qdisc->ops->peek(cl->qdisc);
+		if (!skb) {
+			qdisc_warn_nonwc(__func__, cl->qdisc);
+			goto out;
+		}
+
+		len = qdisc_pkt_len(skb);
+		if (len <= cl->deficit) {
+			cl->deficit -= len;
+			skb = qdisc_dequeue_peeked(cl->qdisc);
+			if (unlikely(!skb))
+				goto out;
+			if (cl->qdisc->q.qlen == 0)
+				list_del(&cl->alist);
+			return ets_qdisc_dequeue_skb(sch, skb);
+		}
+
+		cl->deficit += cl->quantum;
+		list_move_tail(&cl->alist, &q->active);
+	}
+out:
+	return NULL;
+}
+
+static int ets_qdisc_priomap_parse(struct nlattr *priomap_attr,
+				   unsigned int nbands,
+				   u8 priomap[TCA_ETS_MAX + 1],
+				   struct netlink_ext_ack *extack)
+{
+	const struct nlattr *attr;
+	int prio = 0;
+	u8 band;
+	int rem;
+	int err;
+
+	err = nl80211_validate_nested(priomap_attr, TCA_ETS_PMAP_MAX,
+				      ets_pmap_policy, extack);
+	if (err)
+		return err;
+
+	nla_for_each_nested(attr, priomap_attr, rem) {
+		switch (nla_type(attr)) {
+		case TCA_ETS_PMAP_BAND:
+			if (prio > TC_PRIO_MAX) {
+				NL_SET_ERR_MSG_MOD(extack, "Too many priorities in ETS priomap");
+				return -EINVAL;
+			}
+			band = nla_get_u8(attr);
+			if (band >= nbands) {
+				NL_SET_ERR_MSG_MOD(extack, "Invalid band number in ETS priomap");
+				return -EINVAL;
+			}
+			priomap[prio++] = band;
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "ETS priomap can contain only ETS_PMAP_BAND attributes");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int ets_qdisc_quanta_parse(struct Qdisc *sch, struct nlattr *quanta_attr,
+				  unsigned int nbands,
+				  unsigned int nstrict,
+				  unsigned int quanta[TCQ_ETS_MAX_BANDS],
+				  struct netlink_ext_ack *extack)
+{
+	const struct nlattr *attr;
+	int band = nstrict;
+	int rem;
+	int err;
+
+	err = nl80211_validate_nested(quanta_attr, TCA_ETS_BAND_MAX,
+				      ets_band_policy, extack);
+	if (err < 0)
+		return err;
+
+	nla_for_each_nested(attr, quanta_attr, rem) {
+		switch (nla_type(attr)) {
+		case TCA_ETS_BAND_QUANTUM:
+			if (band >= nbands) {
+				NL_SET_ERR_MSG_MOD(extack, "ETS quanta has more values than bands");
+				return -EINVAL;
+			}
+			err = ets_quantum_parse(sch, attr, &quanta[band++],
+						extack);
+			if (err)
+				return err;
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "ETS quanta can contain only ETS_BAND_QUANTUM attributes");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
+			    struct netlink_ext_ack *extack)
+{
+	unsigned int quanta[TCQ_ETS_MAX_BANDS] = {0};
+	struct Qdisc *queues[TCQ_ETS_MAX_BANDS];
+	struct ets_sched *q = qdisc_priv(sch);
+	struct nlattr *tb[TCA_ETS_MAX + 1];
+	u8 priomap[TC_PRIO_MAX + 1] = {0};
+	unsigned int oldbands = q->nbands;
+	unsigned int nstrict = 0;
+	unsigned int nbands;
+	unsigned int i;
+	int err;
+
+	if (!opt) {
+		NL_SET_ERR_MSG(extack, "ETS options are required for this operation");
+		return -EINVAL;
+	}
+
+	err = nla_parse_nested(tb, TCA_ETS_MAX, opt, ets_policy, extack);
+	if (err < 0)
+		return err;
+
+	if (!tb[TCA_ETS_BANDS]) {
+		NL_SET_ERR_MSG_MOD(extack, "Number of bands is a required argument");
+		return -EINVAL;
+	}
+	nbands = nla_get_u8(tb[TCA_ETS_BANDS]);
+	if (nbands < 1 || nbands > TCQ_ETS_MAX_BANDS) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid number of bands");
+		return -EINVAL;
+	}
+
+	if (tb[TCA_ETS_STRICT]) {
+		nstrict = nla_get_u8(tb[TCA_ETS_STRICT]);
+		if (nstrict > nbands) {
+			NL_SET_ERR_MSG_MOD(extack, "Invalid number of strict bands");
+			return -EINVAL;
+		}
+	}
+
+	if (tb[TCA_ETS_PRIOMAP]) {
+		err = ets_qdisc_priomap_parse(tb[TCA_ETS_PRIOMAP],
+					      nbands, priomap, extack);
+		if (err)
+			return err;
+	}
+
+	if (tb[TCA_ETS_QUANTA]) {
+		err = ets_qdisc_quanta_parse(sch, tb[TCA_ETS_QUANTA],
+					     nbands, nstrict, quanta, extack);
+		if (err)
+			return err;
+	}
+	for (i = nstrict; i < nbands; i++) {
+		if (!quanta[i])
+			ets_quantum_parse(sch, NULL, &quanta[i], extack);
+	}
+
+	/* Before commit, make sure we can allocate all new qdiscs */
+	for (i = oldbands; i < nbands; i++) {
+		queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+					      ets_class_id(sch, &q->classes[i]),
+					      extack);
+		if (!queues[i]) {
+			while (i > oldbands)
+				qdisc_put(queues[--i]);
+			return -ENOMEM;
+		}
+	}
+
+	sch_tree_lock(sch);
+
+	q->nbands = nbands;
+	q->nstrict = nstrict;
+	memcpy(q->prio2band, priomap, sizeof(priomap));
+
+	for (i = q->nbands; i < oldbands; i++)
+		qdisc_tree_flush_backlog(q->classes[i].qdisc);
+
+	for (i = 0; i < q->nbands; i++)
+		q->classes[i].quantum = quanta[i];
+
+	for (i = oldbands; i < q->nbands; i++) {
+		q->classes[i].qdisc = queues[i];
+		if (q->classes[i].qdisc != &noop_qdisc)
+			qdisc_hash_add(q->classes[i].qdisc, true);
+	}
+
+	sch_tree_unlock(sch);
+
+	for (i = q->nbands; i < oldbands; i++) {
+		qdisc_put(q->classes[i].qdisc);
+		memset(&q->classes[i], 0, sizeof(q->classes[i]));
+	}
+	return 0;
+}
+
+static int ets_qdisc_init(struct Qdisc *sch, struct nlattr *opt,
+			  struct netlink_ext_ack *extack)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	int err;
+
+	if (!opt)
+		return -EINVAL;
+
+	err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
+	if (err)
+		return err;
+
+	INIT_LIST_HEAD(&q->active);
+	return ets_qdisc_change(sch, opt, extack);
+}
+
+static void ets_qdisc_reset(struct Qdisc *sch)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	int band;
+
+	for (band = q->nstrict; band < q->nbands; band++) {
+		if (q->classes[band].qdisc->q.qlen)
+			list_del(&q->classes[band].alist);
+	}
+	for (band = 0; band < q->nbands; band++)
+		qdisc_reset(q->classes[band].qdisc);
+	sch->qstats.backlog = 0;
+	sch->q.qlen = 0;
+}
+
+static void ets_qdisc_destroy(struct Qdisc *sch)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	int band;
+
+	tcf_block_put(q->block);
+	for (band = 0; band < q->nbands; band++)
+		qdisc_put(q->classes[band].qdisc);
+}
+
+static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct ets_sched *q = qdisc_priv(sch);
+	struct nlattr *opts;
+	struct nlattr *nest;
+	int band;
+	int prio;
+
+	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
+	if (!opts)
+		goto nla_err;
+
+	if (nla_put_u8(skb, TCA_ETS_BANDS, q->nbands))
+		goto nla_err;
+
+	if (q->nstrict &&
+	    nla_put_u8(skb, TCA_ETS_STRICT, q->nstrict))
+		goto nla_err;
+
+	if (q->nbands > q->nstrict) {
+		nest = nla_nest_start(skb, TCA_ETS_QUANTA);
+		if (!nest)
+			goto nla_err;
+
+		for (band = q->nstrict; band < q->nbands; band++) {
+			if (nla_put_u32(skb, TCA_ETS_BAND_QUANTUM,
+					q->classes[band].quantum))
+				goto nla_err;
+		}
+
+		nla_nest_end(skb, nest);
+	}
+
+	nest = nla_nest_start(skb, TCA_ETS_PRIOMAP);
+	if (!nest)
+		goto nla_err;
+
+	for (prio = 0; prio <= TC_PRIO_MAX; prio++) {
+		if (nla_put_u8(skb, TCA_ETS_PMAP_BAND, q->prio2band[prio]))
+			goto nla_err;
+	}
+
+	nla_nest_end(skb, nest);
+
+	return nla_nest_end(skb, opts);
+
+nla_err:
+	nla_nest_cancel(skb, opts);
+	return -EMSGSIZE;
+}
+
+static const struct Qdisc_class_ops ets_class_ops = {
+	.change		= ets_class_change,
+	.graft		= ets_class_graft,
+	.leaf		= ets_class_leaf,
+	.find		= ets_class_find,
+	.qlen_notify	= ets_class_qlen_notify,
+	.dump		= ets_class_dump,
+	.dump_stats	= ets_class_dump_stats,
+	.walk		= ets_qdisc_walk,
+	.tcf_block	= ets_qdisc_tcf_block,
+	.bind_tcf	= ets_qdisc_bind_tcf,
+	.unbind_tcf	= ets_qdisc_unbind_tcf,
+};
+
+static struct Qdisc_ops ets_qdisc_ops __read_mostly = {
+	.cl_ops		= &ets_class_ops,
+	.id		= "ets",
+	.priv_size	= sizeof(struct ets_sched),
+	.enqueue	= ets_qdisc_enqueue,
+	.dequeue	= ets_qdisc_dequeue,
+	.peek		= qdisc_peek_dequeued,
+	.change		= ets_qdisc_change,
+	.init		= ets_qdisc_init,
+	.reset		= ets_qdisc_reset,
+	.destroy	= ets_qdisc_destroy,
+	.dump		= ets_qdisc_dump,
+	.owner		= THIS_MODULE,
+};
+
+static int __init ets_init(void)
+{
+	return register_qdisc(&ets_qdisc_ops);
+}
+
+static void __exit ets_exit(void)
+{
+	unregister_qdisc(&ets_qdisc_ops);
+}
+
+module_init(ets_init);
+module_exit(ets_exit);
+MODULE_LICENSE("GPL");