xref: /kernel/linux/linux-5.10/net/sched/sch_mqprio.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/sched/sch_mqprio.c
4 *
5 * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>
6 */
7
8#include <linux/types.h>
9#include <linux/slab.h>
10#include <linux/kernel.h>
11#include <linux/string.h>
12#include <linux/errno.h>
13#include <linux/skbuff.h>
14#include <linux/module.h>
15#include <net/netlink.h>
16#include <net/pkt_sched.h>
17#include <net/sch_generic.h>
18#include <net/pkt_cls.h>
19
20struct mqprio_sched {
21	struct Qdisc		**qdiscs;
22	u16 mode;
23	u16 shaper;
24	int hw_offload;
25	u32 flags;
26	u64 min_rate[TC_QOPT_MAX_QUEUE];
27	u64 max_rate[TC_QOPT_MAX_QUEUE];
28};
29
30static void mqprio_destroy(struct Qdisc *sch)
31{
32	struct net_device *dev = qdisc_dev(sch);
33	struct mqprio_sched *priv = qdisc_priv(sch);
34	unsigned int ntx;
35
36	if (priv->qdiscs) {
37		for (ntx = 0;
38		     ntx < dev->num_tx_queues && priv->qdiscs[ntx];
39		     ntx++)
40			qdisc_put(priv->qdiscs[ntx]);
41		kfree(priv->qdiscs);
42	}
43
44	if (priv->hw_offload && dev->netdev_ops->ndo_setup_tc) {
45		struct tc_mqprio_qopt_offload mqprio = { { 0 } };
46
47		switch (priv->mode) {
48		case TC_MQPRIO_MODE_DCB:
49		case TC_MQPRIO_MODE_CHANNEL:
50			dev->netdev_ops->ndo_setup_tc(dev,
51						      TC_SETUP_QDISC_MQPRIO,
52						      &mqprio);
53			break;
54		default:
55			return;
56		}
57	} else {
58		netdev_set_num_tc(dev, 0);
59	}
60}
61
62static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
63{
64	int i, j;
65
66	/* Verify num_tc is not out of max range */
67	if (qopt->num_tc > TC_MAX_QUEUE)
68		return -EINVAL;
69
70	/* Verify priority mapping uses valid tcs */
71	for (i = 0; i < TC_BITMASK + 1; i++) {
72		if (qopt->prio_tc_map[i] >= qopt->num_tc)
73			return -EINVAL;
74	}
75
76	/* Limit qopt->hw to maximum supported offload value.  Drivers have
77	 * the option of overriding this later if they don't support the a
78	 * given offload type.
79	 */
80	if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX)
81		qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX;
82
83	/* If hardware offload is requested we will leave it to the device
84	 * to either populate the queue counts itself or to validate the
85	 * provided queue counts.  If ndo_setup_tc is not present then
86	 * hardware doesn't support offload and we should return an error.
87	 */
88	if (qopt->hw)
89		return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL;
90
91	for (i = 0; i < qopt->num_tc; i++) {
92		unsigned int last = qopt->offset[i] + qopt->count[i];
93
94		/* Verify the queue count is in tx range being equal to the
95		 * real_num_tx_queues indicates the last queue is in use.
96		 */
97		if (qopt->offset[i] >= dev->real_num_tx_queues ||
98		    !qopt->count[i] ||
99		    last > dev->real_num_tx_queues)
100			return -EINVAL;
101
102		/* Verify that the offset and counts do not overlap */
103		for (j = i + 1; j < qopt->num_tc; j++) {
104			if (last > qopt->offset[j])
105				return -EINVAL;
106		}
107	}
108
109	return 0;
110}
111
112static const struct nla_policy mqprio_policy[TCA_MQPRIO_MAX + 1] = {
113	[TCA_MQPRIO_MODE]	= { .len = sizeof(u16) },
114	[TCA_MQPRIO_SHAPER]	= { .len = sizeof(u16) },
115	[TCA_MQPRIO_MIN_RATE64]	= { .type = NLA_NESTED },
116	[TCA_MQPRIO_MAX_RATE64]	= { .type = NLA_NESTED },
117};
118
119static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
120		      const struct nla_policy *policy, int len)
121{
122	int nested_len = nla_len(nla) - NLA_ALIGN(len);
123
124	if (nested_len >= nla_attr_size(0))
125		return nla_parse_deprecated(tb, maxtype,
126					    nla_data(nla) + NLA_ALIGN(len),
127					    nested_len, policy, NULL);
128
129	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
130	return 0;
131}
132
133static int mqprio_parse_nlattr(struct Qdisc *sch, struct tc_mqprio_qopt *qopt,
134			       struct nlattr *opt,
135			       struct netlink_ext_ack *extack)
136{
137	struct mqprio_sched *priv = qdisc_priv(sch);
138	struct nlattr *tb[TCA_MQPRIO_MAX + 1];
139	struct nlattr *attr;
140	int i, rem, err;
141
142	err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
143			 sizeof(*qopt));
144	if (err < 0)
145		return err;
146
147	if (!qopt->hw) {
148		NL_SET_ERR_MSG(extack,
149			       "mqprio TCA_OPTIONS can only contain netlink attributes in hardware mode");
150		return -EINVAL;
151	}
152
153	if (tb[TCA_MQPRIO_MODE]) {
154		priv->flags |= TC_MQPRIO_F_MODE;
155		priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
156	}
157
158	if (tb[TCA_MQPRIO_SHAPER]) {
159		priv->flags |= TC_MQPRIO_F_SHAPER;
160		priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
161	}
162
163	if (tb[TCA_MQPRIO_MIN_RATE64]) {
164		if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
165			NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MIN_RATE64],
166					    "min_rate accepted only when shaper is in bw_rlimit mode");
167			return -EINVAL;
168		}
169		i = 0;
170		nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
171				    rem) {
172			if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64) {
173				NL_SET_ERR_MSG_ATTR(extack, attr,
174						    "Attribute type expected to be TCA_MQPRIO_MIN_RATE64");
175				return -EINVAL;
176			}
177
178			if (nla_len(attr) != sizeof(u64)) {
179				NL_SET_ERR_MSG_ATTR(extack, attr,
180						    "Attribute TCA_MQPRIO_MIN_RATE64 expected to have 8 bytes length");
181				return -EINVAL;
182			}
183
184			if (i >= qopt->num_tc)
185				break;
186			priv->min_rate[i] = *(u64 *)nla_data(attr);
187			i++;
188		}
189		priv->flags |= TC_MQPRIO_F_MIN_RATE;
190	}
191
192	if (tb[TCA_MQPRIO_MAX_RATE64]) {
193		if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
194			NL_SET_ERR_MSG_ATTR(extack, tb[TCA_MQPRIO_MAX_RATE64],
195					    "max_rate accepted only when shaper is in bw_rlimit mode");
196			return -EINVAL;
197		}
198		i = 0;
199		nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
200				    rem) {
201			if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64) {
202				NL_SET_ERR_MSG_ATTR(extack, attr,
203						    "Attribute type expected to be TCA_MQPRIO_MAX_RATE64");
204				return -EINVAL;
205			}
206
207			if (nla_len(attr) != sizeof(u64)) {
208				NL_SET_ERR_MSG_ATTR(extack, attr,
209						    "Attribute TCA_MQPRIO_MAX_RATE64 expected to have 8 bytes length");
210				return -EINVAL;
211			}
212
213			if (i >= qopt->num_tc)
214				break;
215			priv->max_rate[i] = *(u64 *)nla_data(attr);
216			i++;
217		}
218		priv->flags |= TC_MQPRIO_F_MAX_RATE;
219	}
220
221	return 0;
222}
223
224static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
225		       struct netlink_ext_ack *extack)
226{
227	struct net_device *dev = qdisc_dev(sch);
228	struct mqprio_sched *priv = qdisc_priv(sch);
229	struct netdev_queue *dev_queue;
230	struct Qdisc *qdisc;
231	int i, err = -EOPNOTSUPP;
232	struct tc_mqprio_qopt *qopt = NULL;
233	int len;
234
235	BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
236	BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
237
238	if (sch->parent != TC_H_ROOT)
239		return -EOPNOTSUPP;
240
241	if (!netif_is_multiqueue(dev))
242		return -EOPNOTSUPP;
243
244	/* make certain can allocate enough classids to handle queues */
245	if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
246		return -ENOMEM;
247
248	if (!opt || nla_len(opt) < sizeof(*qopt))
249		return -EINVAL;
250
251	qopt = nla_data(opt);
252	if (mqprio_parse_opt(dev, qopt))
253		return -EINVAL;
254
255	len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
256	if (len > 0) {
257		err = mqprio_parse_nlattr(sch, qopt, opt, extack);
258		if (err)
259			return err;
260	}
261
262	/* pre-allocate qdisc, attachment can't fail */
263	priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
264			       GFP_KERNEL);
265	if (!priv->qdiscs)
266		return -ENOMEM;
267
268	for (i = 0; i < dev->num_tx_queues; i++) {
269		dev_queue = netdev_get_tx_queue(dev, i);
270		qdisc = qdisc_create_dflt(dev_queue,
271					  get_default_qdisc_ops(dev, i),
272					  TC_H_MAKE(TC_H_MAJ(sch->handle),
273						    TC_H_MIN(i + 1)), extack);
274		if (!qdisc)
275			return -ENOMEM;
276
277		priv->qdiscs[i] = qdisc;
278		qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
279	}
280
281	/* If the mqprio options indicate that hardware should own
282	 * the queue mapping then run ndo_setup_tc otherwise use the
283	 * supplied and verified mapping
284	 */
285	if (qopt->hw) {
286		struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
287
288		switch (priv->mode) {
289		case TC_MQPRIO_MODE_DCB:
290			if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
291				return -EINVAL;
292			break;
293		case TC_MQPRIO_MODE_CHANNEL:
294			mqprio.flags = priv->flags;
295			if (priv->flags & TC_MQPRIO_F_MODE)
296				mqprio.mode = priv->mode;
297			if (priv->flags & TC_MQPRIO_F_SHAPER)
298				mqprio.shaper = priv->shaper;
299			if (priv->flags & TC_MQPRIO_F_MIN_RATE)
300				for (i = 0; i < mqprio.qopt.num_tc; i++)
301					mqprio.min_rate[i] = priv->min_rate[i];
302			if (priv->flags & TC_MQPRIO_F_MAX_RATE)
303				for (i = 0; i < mqprio.qopt.num_tc; i++)
304					mqprio.max_rate[i] = priv->max_rate[i];
305			break;
306		default:
307			return -EINVAL;
308		}
309		err = dev->netdev_ops->ndo_setup_tc(dev,
310						    TC_SETUP_QDISC_MQPRIO,
311						    &mqprio);
312		if (err)
313			return err;
314
315		priv->hw_offload = mqprio.qopt.hw;
316	} else {
317		netdev_set_num_tc(dev, qopt->num_tc);
318		for (i = 0; i < qopt->num_tc; i++)
319			netdev_set_tc_queue(dev, i,
320					    qopt->count[i], qopt->offset[i]);
321	}
322
323	/* Always use supplied priority mappings */
324	for (i = 0; i < TC_BITMASK + 1; i++)
325		netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
326
327	sch->flags |= TCQ_F_MQROOT;
328	return 0;
329}
330
331static void mqprio_attach(struct Qdisc *sch)
332{
333	struct net_device *dev = qdisc_dev(sch);
334	struct mqprio_sched *priv = qdisc_priv(sch);
335	struct Qdisc *qdisc, *old;
336	unsigned int ntx;
337
338	/* Attach underlying qdisc */
339	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
340		qdisc = priv->qdiscs[ntx];
341		old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
342		if (old)
343			qdisc_put(old);
344		if (ntx < dev->real_num_tx_queues)
345			qdisc_hash_add(qdisc, false);
346	}
347	kfree(priv->qdiscs);
348	priv->qdiscs = NULL;
349}
350
351static void mqprio_change_real_num_tx(struct Qdisc *sch,
352				      unsigned int new_real_tx)
353{
354	struct net_device *dev = qdisc_dev(sch);
355	struct Qdisc *qdisc;
356	unsigned int i;
357
358	for (i = new_real_tx; i < dev->real_num_tx_queues; i++) {
359		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
360		/* Only update the default qdiscs we created,
361		 * qdiscs with handles are always hashed.
362		 */
363		if (qdisc != &noop_qdisc && !qdisc->handle)
364			qdisc_hash_del(qdisc);
365	}
366	for (i = dev->real_num_tx_queues; i < new_real_tx; i++) {
367		qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping;
368		if (qdisc != &noop_qdisc && !qdisc->handle)
369			qdisc_hash_add(qdisc, false);
370	}
371}
372
373static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
374					     unsigned long cl)
375{
376	struct net_device *dev = qdisc_dev(sch);
377	unsigned long ntx = cl - 1;
378
379	if (ntx >= dev->num_tx_queues)
380		return NULL;
381	return netdev_get_tx_queue(dev, ntx);
382}
383
384static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
385			struct Qdisc **old, struct netlink_ext_ack *extack)
386{
387	struct net_device *dev = qdisc_dev(sch);
388	struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
389
390	if (!dev_queue)
391		return -EINVAL;
392
393	if (dev->flags & IFF_UP)
394		dev_deactivate(dev);
395
396	*old = dev_graft_qdisc(dev_queue, new);
397
398	if (new)
399		new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
400
401	if (dev->flags & IFF_UP)
402		dev_activate(dev);
403
404	return 0;
405}
406
407static int dump_rates(struct mqprio_sched *priv,
408		      struct tc_mqprio_qopt *opt, struct sk_buff *skb)
409{
410	struct nlattr *nest;
411	int i;
412
413	if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
414		nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MIN_RATE64);
415		if (!nest)
416			goto nla_put_failure;
417
418		for (i = 0; i < opt->num_tc; i++) {
419			if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
420				    sizeof(priv->min_rate[i]),
421				    &priv->min_rate[i]))
422				goto nla_put_failure;
423		}
424		nla_nest_end(skb, nest);
425	}
426
427	if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
428		nest = nla_nest_start_noflag(skb, TCA_MQPRIO_MAX_RATE64);
429		if (!nest)
430			goto nla_put_failure;
431
432		for (i = 0; i < opt->num_tc; i++) {
433			if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
434				    sizeof(priv->max_rate[i]),
435				    &priv->max_rate[i]))
436				goto nla_put_failure;
437		}
438		nla_nest_end(skb, nest);
439	}
440	return 0;
441
442nla_put_failure:
443	nla_nest_cancel(skb, nest);
444	return -1;
445}
446
447static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
448{
449	struct net_device *dev = qdisc_dev(sch);
450	struct mqprio_sched *priv = qdisc_priv(sch);
451	struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
452	struct tc_mqprio_qopt opt = { 0 };
453	struct Qdisc *qdisc;
454	unsigned int ntx, tc;
455
456	sch->q.qlen = 0;
457	memset(&sch->bstats, 0, sizeof(sch->bstats));
458	memset(&sch->qstats, 0, sizeof(sch->qstats));
459
460	/* MQ supports lockless qdiscs. However, statistics accounting needs
461	 * to account for all, none, or a mix of locked and unlocked child
462	 * qdiscs. Percpu stats are added to counters in-band and locking
463	 * qdisc totals are added at end.
464	 */
465	for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
466		qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
467		spin_lock_bh(qdisc_lock(qdisc));
468
469		if (qdisc_is_percpu_stats(qdisc)) {
470			__u32 qlen = qdisc_qlen_sum(qdisc);
471
472			__gnet_stats_copy_basic(NULL, &sch->bstats,
473						qdisc->cpu_bstats,
474						&qdisc->bstats);
475			__gnet_stats_copy_queue(&sch->qstats,
476						qdisc->cpu_qstats,
477						&qdisc->qstats, qlen);
478			sch->q.qlen		+= qlen;
479		} else {
480			sch->q.qlen		+= qdisc->q.qlen;
481			sch->bstats.bytes	+= qdisc->bstats.bytes;
482			sch->bstats.packets	+= qdisc->bstats.packets;
483			sch->qstats.backlog	+= qdisc->qstats.backlog;
484			sch->qstats.drops	+= qdisc->qstats.drops;
485			sch->qstats.requeues	+= qdisc->qstats.requeues;
486			sch->qstats.overlimits	+= qdisc->qstats.overlimits;
487		}
488
489		spin_unlock_bh(qdisc_lock(qdisc));
490	}
491
492	opt.num_tc = netdev_get_num_tc(dev);
493	memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
494	opt.hw = priv->hw_offload;
495
496	for (tc = 0; tc < netdev_get_num_tc(dev); tc++) {
497		opt.count[tc] = dev->tc_to_txq[tc].count;
498		opt.offset[tc] = dev->tc_to_txq[tc].offset;
499	}
500
501	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
502		goto nla_put_failure;
503
504	if ((priv->flags & TC_MQPRIO_F_MODE) &&
505	    nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
506		goto nla_put_failure;
507
508	if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
509	    nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
510		goto nla_put_failure;
511
512	if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
513	     priv->flags & TC_MQPRIO_F_MAX_RATE) &&
514	    (dump_rates(priv, &opt, skb) != 0))
515		goto nla_put_failure;
516
517	return nla_nest_end(skb, nla);
518nla_put_failure:
519	nlmsg_trim(skb, nla);
520	return -1;
521}
522
523static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
524{
525	struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
526
527	if (!dev_queue)
528		return NULL;
529
530	return dev_queue->qdisc_sleeping;
531}
532
533static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
534{
535	struct net_device *dev = qdisc_dev(sch);
536	unsigned int ntx = TC_H_MIN(classid);
537
538	/* There are essentially two regions here that have valid classid
539	 * values. The first region will have a classid value of 1 through
540	 * num_tx_queues. All of these are backed by actual Qdiscs.
541	 */
542	if (ntx < TC_H_MIN_PRIORITY)
543		return (ntx <= dev->num_tx_queues) ? ntx : 0;
544
545	/* The second region represents the hardware traffic classes. These
546	 * are represented by classid values of TC_H_MIN_PRIORITY through
547	 * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
548	 */
549	return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
550}
551
552static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
553			 struct sk_buff *skb, struct tcmsg *tcm)
554{
555	if (cl < TC_H_MIN_PRIORITY) {
556		struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
557		struct net_device *dev = qdisc_dev(sch);
558		int tc = netdev_txq_to_tc(dev, cl - 1);
559
560		tcm->tcm_parent = (tc < 0) ? 0 :
561			TC_H_MAKE(TC_H_MAJ(sch->handle),
562				  TC_H_MIN(tc + TC_H_MIN_PRIORITY));
563		tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
564	} else {
565		tcm->tcm_parent = TC_H_ROOT;
566		tcm->tcm_info = 0;
567	}
568	tcm->tcm_handle |= TC_H_MIN(cl);
569	return 0;
570}
571
572static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
573				   struct gnet_dump *d)
574	__releases(d->lock)
575	__acquires(d->lock)
576{
577	if (cl >= TC_H_MIN_PRIORITY) {
578		int i;
579		__u32 qlen = 0;
580		struct gnet_stats_queue qstats = {0};
581		struct gnet_stats_basic_packed bstats = {0};
582		struct net_device *dev = qdisc_dev(sch);
583		struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
584
585		/* Drop lock here it will be reclaimed before touching
586		 * statistics this is required because the d->lock we
587		 * hold here is the look on dev_queue->qdisc_sleeping
588		 * also acquired below.
589		 */
590		if (d->lock)
591			spin_unlock_bh(d->lock);
592
593		for (i = tc.offset; i < tc.offset + tc.count; i++) {
594			struct netdev_queue *q = netdev_get_tx_queue(dev, i);
595			struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
596
597			spin_lock_bh(qdisc_lock(qdisc));
598
599			if (qdisc_is_percpu_stats(qdisc)) {
600				qlen = qdisc_qlen_sum(qdisc);
601
602				__gnet_stats_copy_basic(NULL, &bstats,
603							qdisc->cpu_bstats,
604							&qdisc->bstats);
605				__gnet_stats_copy_queue(&qstats,
606							qdisc->cpu_qstats,
607							&qdisc->qstats,
608							qlen);
609			} else {
610				qlen		+= qdisc->q.qlen;
611				bstats.bytes	+= qdisc->bstats.bytes;
612				bstats.packets	+= qdisc->bstats.packets;
613				qstats.backlog	+= qdisc->qstats.backlog;
614				qstats.drops	+= qdisc->qstats.drops;
615				qstats.requeues	+= qdisc->qstats.requeues;
616				qstats.overlimits += qdisc->qstats.overlimits;
617			}
618			spin_unlock_bh(qdisc_lock(qdisc));
619		}
620
621		/* Reclaim root sleeping lock before completing stats */
622		if (d->lock)
623			spin_lock_bh(d->lock);
624		if (gnet_stats_copy_basic(NULL, d, NULL, &bstats) < 0 ||
625		    gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
626			return -1;
627	} else {
628		struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
629
630		sch = dev_queue->qdisc_sleeping;
631		if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d,
632					  sch->cpu_bstats, &sch->bstats) < 0 ||
633		    qdisc_qstats_copy(d, sch) < 0)
634			return -1;
635	}
636	return 0;
637}
638
639static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
640{
641	struct net_device *dev = qdisc_dev(sch);
642	unsigned long ntx;
643
644	if (arg->stop)
645		return;
646
647	/* Walk hierarchy with a virtual class per tc */
648	arg->count = arg->skip;
649	for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
650		if (arg->fn(sch, ntx + TC_H_MIN_PRIORITY, arg) < 0) {
651			arg->stop = 1;
652			return;
653		}
654		arg->count++;
655	}
656
657	/* Pad the values and skip over unused traffic classes */
658	if (ntx < TC_MAX_QUEUE) {
659		arg->count = TC_MAX_QUEUE;
660		ntx = TC_MAX_QUEUE;
661	}
662
663	/* Reset offset, sort out remaining per-queue qdiscs */
664	for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
665		if (arg->fn(sch, ntx + 1, arg) < 0) {
666			arg->stop = 1;
667			return;
668		}
669		arg->count++;
670	}
671}
672
673static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
674						struct tcmsg *tcm)
675{
676	return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
677}
678
679static const struct Qdisc_class_ops mqprio_class_ops = {
680	.graft		= mqprio_graft,
681	.leaf		= mqprio_leaf,
682	.find		= mqprio_find,
683	.walk		= mqprio_walk,
684	.dump		= mqprio_dump_class,
685	.dump_stats	= mqprio_dump_class_stats,
686	.select_queue	= mqprio_select_queue,
687};
688
689static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
690	.cl_ops		= &mqprio_class_ops,
691	.id		= "mqprio",
692	.priv_size	= sizeof(struct mqprio_sched),
693	.init		= mqprio_init,
694	.destroy	= mqprio_destroy,
695	.attach		= mqprio_attach,
696	.change_real_num_tx = mqprio_change_real_num_tx,
697	.dump		= mqprio_dump,
698	.owner		= THIS_MODULE,
699};
700
701static int __init mqprio_module_init(void)
702{
703	return register_qdisc(&mqprio_qdisc_ops);
704}
705
706static void __exit mqprio_module_exit(void)
707{
708	unregister_qdisc(&mqprio_qdisc_ops);
709}
710
711module_init(mqprio_module_init);
712module_exit(mqprio_module_exit);
713
714MODULE_LICENSE("GPL");
715