// SPDX-License-Identifier: GPL-2.0-only

  /*
   * net/sched/sch_mqprio.c
   *
   * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>

   */
  
  #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_deprecated(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 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_noflag(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_noflag(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);
  			struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
  			struct gnet_stats_queue __percpu *cpu_qstats = NULL;

  			spin_lock_bh(qdisc_lock(qdisc));

  			if (qdisc_is_percpu_stats(qdisc)) {
  				cpu_bstats = qdisc->cpu_bstats;
  				cpu_qstats = qdisc->cpu_qstats;
  			}
  
  			qlen = qdisc_qlen_sum(qdisc);
  			__gnet_stats_copy_basic(NULL, &sch->bstats,
  						cpu_bstats, &qdisc->bstats);
  			__gnet_stats_copy_queue(&sch->qstats,
  						cpu_qstats,
  						&qdisc->qstats,
  						qlen);

  			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 ||

  		    qdisc_qstats_copy(d, sch) < 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,
  	.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");