2 * net/sched/sch_mqprio.c
4 * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/errno.h>
16 #include <linux/skbuff.h>
17 #include <linux/module.h>
18 #include <net/netlink.h>
19 #include <net/pkt_sched.h>
20 #include <net/sch_generic.h>
21 #include <net/pkt_cls.h>
24 struct Qdisc **qdiscs;
29 u64 min_rate[TC_QOPT_MAX_QUEUE];
30 u64 max_rate[TC_QOPT_MAX_QUEUE];
33 static void mqprio_destroy(struct Qdisc *sch)
35 struct net_device *dev = qdisc_dev(sch);
36 struct mqprio_sched *priv = qdisc_priv(sch);
41 ntx < dev->num_tx_queues && priv->qdiscs[ntx];
43 qdisc_destroy(priv->qdiscs[ntx]);
47 if (priv->hw_offload && dev->netdev_ops->ndo_setup_tc) {
48 struct tc_mqprio_qopt_offload mqprio = { { 0 } };
51 case TC_MQPRIO_MODE_DCB:
52 case TC_MQPRIO_MODE_CHANNEL:
53 dev->netdev_ops->ndo_setup_tc(dev,
54 TC_SETUP_QDISC_MQPRIO,
61 netdev_set_num_tc(dev, 0);
65 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
69 /* Verify num_tc is not out of max range */
70 if (qopt->num_tc > TC_MAX_QUEUE)
73 /* Verify priority mapping uses valid tcs */
74 for (i = 0; i < TC_BITMASK + 1; i++) {
75 if (qopt->prio_tc_map[i] >= qopt->num_tc)
79 /* Limit qopt->hw to maximum supported offload value. Drivers have
80 * the option of overriding this later if they don't support the a
83 if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX)
84 qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX;
86 /* If hardware offload is requested we will leave it to the device
87 * to either populate the queue counts itself or to validate the
88 * provided queue counts. If ndo_setup_tc is not present then
89 * hardware doesn't support offload and we should return an error.
92 return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL;
94 for (i = 0; i < qopt->num_tc; i++) {
95 unsigned int last = qopt->offset[i] + qopt->count[i];
97 /* Verify the queue count is in tx range being equal to the
98 * real_num_tx_queues indicates the last queue is in use.
100 if (qopt->offset[i] >= dev->real_num_tx_queues ||
102 last > dev->real_num_tx_queues)
105 /* Verify that the offset and counts do not overlap */
106 for (j = i + 1; j < qopt->num_tc; j++) {
107 if (last > qopt->offset[j])
115 static const struct nla_policy mqprio_policy[TCA_MQPRIO_MAX + 1] = {
116 [TCA_MQPRIO_MODE] = { .len = sizeof(u16) },
117 [TCA_MQPRIO_SHAPER] = { .len = sizeof(u16) },
118 [TCA_MQPRIO_MIN_RATE64] = { .type = NLA_NESTED },
119 [TCA_MQPRIO_MAX_RATE64] = { .type = NLA_NESTED },
122 static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla,
123 const struct nla_policy *policy, int len)
125 int nested_len = nla_len(nla) - NLA_ALIGN(len);
127 if (nested_len >= nla_attr_size(0))
128 return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
129 nested_len, policy, NULL);
131 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
135 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
136 struct netlink_ext_ack *extack)
138 struct net_device *dev = qdisc_dev(sch);
139 struct mqprio_sched *priv = qdisc_priv(sch);
140 struct netdev_queue *dev_queue;
142 int i, err = -EOPNOTSUPP;
143 struct tc_mqprio_qopt *qopt = NULL;
144 struct nlattr *tb[TCA_MQPRIO_MAX + 1];
149 BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
150 BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK);
152 if (sch->parent != TC_H_ROOT)
155 if (!netif_is_multiqueue(dev))
158 /* make certain can allocate enough classids to handle queues */
159 if (dev->num_tx_queues >= TC_H_MIN_PRIORITY)
162 if (!opt || nla_len(opt) < sizeof(*qopt))
165 qopt = nla_data(opt);
166 if (mqprio_parse_opt(dev, qopt))
169 len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));
171 err = parse_attr(tb, TCA_MQPRIO_MAX, opt, mqprio_policy,
179 if (tb[TCA_MQPRIO_MODE]) {
180 priv->flags |= TC_MQPRIO_F_MODE;
181 priv->mode = *(u16 *)nla_data(tb[TCA_MQPRIO_MODE]);
184 if (tb[TCA_MQPRIO_SHAPER]) {
185 priv->flags |= TC_MQPRIO_F_SHAPER;
186 priv->shaper = *(u16 *)nla_data(tb[TCA_MQPRIO_SHAPER]);
189 if (tb[TCA_MQPRIO_MIN_RATE64]) {
190 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
193 nla_for_each_nested(attr, tb[TCA_MQPRIO_MIN_RATE64],
195 if (nla_type(attr) != TCA_MQPRIO_MIN_RATE64)
197 if (i >= qopt->num_tc)
199 priv->min_rate[i] = *(u64 *)nla_data(attr);
202 priv->flags |= TC_MQPRIO_F_MIN_RATE;
205 if (tb[TCA_MQPRIO_MAX_RATE64]) {
206 if (priv->shaper != TC_MQPRIO_SHAPER_BW_RATE)
209 nla_for_each_nested(attr, tb[TCA_MQPRIO_MAX_RATE64],
211 if (nla_type(attr) != TCA_MQPRIO_MAX_RATE64)
213 if (i >= qopt->num_tc)
215 priv->max_rate[i] = *(u64 *)nla_data(attr);
218 priv->flags |= TC_MQPRIO_F_MAX_RATE;
222 /* pre-allocate qdisc, attachment can't fail */
223 priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
228 for (i = 0; i < dev->num_tx_queues; i++) {
229 dev_queue = netdev_get_tx_queue(dev, i);
230 qdisc = qdisc_create_dflt(dev_queue,
231 get_default_qdisc_ops(dev, i),
232 TC_H_MAKE(TC_H_MAJ(sch->handle),
233 TC_H_MIN(i + 1)), extack);
237 priv->qdiscs[i] = qdisc;
238 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
241 /* If the mqprio options indicate that hardware should own
242 * the queue mapping then run ndo_setup_tc otherwise use the
243 * supplied and verified mapping
246 struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
248 switch (priv->mode) {
249 case TC_MQPRIO_MODE_DCB:
250 if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
253 case TC_MQPRIO_MODE_CHANNEL:
254 mqprio.flags = priv->flags;
255 if (priv->flags & TC_MQPRIO_F_MODE)
256 mqprio.mode = priv->mode;
257 if (priv->flags & TC_MQPRIO_F_SHAPER)
258 mqprio.shaper = priv->shaper;
259 if (priv->flags & TC_MQPRIO_F_MIN_RATE)
260 for (i = 0; i < mqprio.qopt.num_tc; i++)
261 mqprio.min_rate[i] = priv->min_rate[i];
262 if (priv->flags & TC_MQPRIO_F_MAX_RATE)
263 for (i = 0; i < mqprio.qopt.num_tc; i++)
264 mqprio.max_rate[i] = priv->max_rate[i];
269 err = dev->netdev_ops->ndo_setup_tc(dev,
270 TC_SETUP_QDISC_MQPRIO,
275 priv->hw_offload = mqprio.qopt.hw;
277 netdev_set_num_tc(dev, qopt->num_tc);
278 for (i = 0; i < qopt->num_tc; i++)
279 netdev_set_tc_queue(dev, i,
280 qopt->count[i], qopt->offset[i]);
283 /* Always use supplied priority mappings */
284 for (i = 0; i < TC_BITMASK + 1; i++)
285 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]);
287 sch->flags |= TCQ_F_MQROOT;
291 static void mqprio_attach(struct Qdisc *sch)
293 struct net_device *dev = qdisc_dev(sch);
294 struct mqprio_sched *priv = qdisc_priv(sch);
295 struct Qdisc *qdisc, *old;
298 /* Attach underlying qdisc */
299 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
300 qdisc = priv->qdiscs[ntx];
301 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
304 if (ntx < dev->real_num_tx_queues)
305 qdisc_hash_add(qdisc, false);
311 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
314 struct net_device *dev = qdisc_dev(sch);
315 unsigned long ntx = cl - 1;
317 if (ntx >= dev->num_tx_queues)
319 return netdev_get_tx_queue(dev, ntx);
322 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
323 struct Qdisc **old, struct netlink_ext_ack *extack)
325 struct net_device *dev = qdisc_dev(sch);
326 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
331 if (dev->flags & IFF_UP)
334 *old = dev_graft_qdisc(dev_queue, new);
337 new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
339 if (dev->flags & IFF_UP)
345 static int dump_rates(struct mqprio_sched *priv,
346 struct tc_mqprio_qopt *opt, struct sk_buff *skb)
351 if (priv->flags & TC_MQPRIO_F_MIN_RATE) {
352 nest = nla_nest_start(skb, TCA_MQPRIO_MIN_RATE64);
354 goto nla_put_failure;
356 for (i = 0; i < opt->num_tc; i++) {
357 if (nla_put(skb, TCA_MQPRIO_MIN_RATE64,
358 sizeof(priv->min_rate[i]),
360 goto nla_put_failure;
362 nla_nest_end(skb, nest);
365 if (priv->flags & TC_MQPRIO_F_MAX_RATE) {
366 nest = nla_nest_start(skb, TCA_MQPRIO_MAX_RATE64);
368 goto nla_put_failure;
370 for (i = 0; i < opt->num_tc; i++) {
371 if (nla_put(skb, TCA_MQPRIO_MAX_RATE64,
372 sizeof(priv->max_rate[i]),
374 goto nla_put_failure;
376 nla_nest_end(skb, nest);
381 nla_nest_cancel(skb, nest);
385 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
387 struct net_device *dev = qdisc_dev(sch);
388 struct mqprio_sched *priv = qdisc_priv(sch);
389 struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb);
390 struct tc_mqprio_qopt opt = { 0 };
392 unsigned int ntx, tc;
395 memset(&sch->bstats, 0, sizeof(sch->bstats));
396 memset(&sch->qstats, 0, sizeof(sch->qstats));
398 /* MQ supports lockless qdiscs. However, statistics accounting needs
399 * to account for all, none, or a mix of locked and unlocked child
400 * qdiscs. Percpu stats are added to counters in-band and locking
401 * qdisc totals are added at end.
403 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
404 qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
405 spin_lock_bh(qdisc_lock(qdisc));
407 if (qdisc_is_percpu_stats(qdisc)) {
408 __u32 qlen = qdisc_qlen_sum(qdisc);
410 __gnet_stats_copy_basic(NULL, &sch->bstats,
413 __gnet_stats_copy_queue(&sch->qstats,
415 &qdisc->qstats, qlen);
418 sch->q.qlen += qdisc->q.qlen;
419 sch->bstats.bytes += qdisc->bstats.bytes;
420 sch->bstats.packets += qdisc->bstats.packets;
421 sch->qstats.backlog += qdisc->qstats.backlog;
422 sch->qstats.drops += qdisc->qstats.drops;
423 sch->qstats.requeues += qdisc->qstats.requeues;
424 sch->qstats.overlimits += qdisc->qstats.overlimits;
427 spin_unlock_bh(qdisc_lock(qdisc));
430 opt.num_tc = netdev_get_num_tc(dev);
431 memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
432 opt.hw = priv->hw_offload;
434 for (tc = 0; tc < netdev_get_num_tc(dev); tc++) {
435 opt.count[tc] = dev->tc_to_txq[tc].count;
436 opt.offset[tc] = dev->tc_to_txq[tc].offset;
439 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
440 goto nla_put_failure;
442 if ((priv->flags & TC_MQPRIO_F_MODE) &&
443 nla_put_u16(skb, TCA_MQPRIO_MODE, priv->mode))
444 goto nla_put_failure;
446 if ((priv->flags & TC_MQPRIO_F_SHAPER) &&
447 nla_put_u16(skb, TCA_MQPRIO_SHAPER, priv->shaper))
448 goto nla_put_failure;
450 if ((priv->flags & TC_MQPRIO_F_MIN_RATE ||
451 priv->flags & TC_MQPRIO_F_MAX_RATE) &&
452 (dump_rates(priv, &opt, skb) != 0))
453 goto nla_put_failure;
455 return nla_nest_end(skb, nla);
457 nlmsg_trim(skb, nla);
461 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
463 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
468 return dev_queue->qdisc_sleeping;
471 static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
473 struct net_device *dev = qdisc_dev(sch);
474 unsigned int ntx = TC_H_MIN(classid);
476 /* There are essentially two regions here that have valid classid
477 * values. The first region will have a classid value of 1 through
478 * num_tx_queues. All of these are backed by actual Qdiscs.
480 if (ntx < TC_H_MIN_PRIORITY)
481 return (ntx <= dev->num_tx_queues) ? ntx : 0;
483 /* The second region represents the hardware traffic classes. These
484 * are represented by classid values of TC_H_MIN_PRIORITY through
485 * TC_H_MIN_PRIORITY + netdev_get_num_tc - 1
487 return ((ntx - TC_H_MIN_PRIORITY) < netdev_get_num_tc(dev)) ? ntx : 0;
490 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
491 struct sk_buff *skb, struct tcmsg *tcm)
493 if (cl < TC_H_MIN_PRIORITY) {
494 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
495 struct net_device *dev = qdisc_dev(sch);
496 int tc = netdev_txq_to_tc(dev, cl - 1);
498 tcm->tcm_parent = (tc < 0) ? 0 :
499 TC_H_MAKE(TC_H_MAJ(sch->handle),
500 TC_H_MIN(tc + TC_H_MIN_PRIORITY));
501 tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
503 tcm->tcm_parent = TC_H_ROOT;
506 tcm->tcm_handle |= TC_H_MIN(cl);
510 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
515 if (cl >= TC_H_MIN_PRIORITY) {
518 struct gnet_stats_queue qstats = {0};
519 struct gnet_stats_basic_packed bstats = {0};
520 struct net_device *dev = qdisc_dev(sch);
521 struct netdev_tc_txq tc = dev->tc_to_txq[cl & TC_BITMASK];
523 /* Drop lock here it will be reclaimed before touching
524 * statistics this is required because the d->lock we
525 * hold here is the look on dev_queue->qdisc_sleeping
526 * also acquired below.
529 spin_unlock_bh(d->lock);
531 for (i = tc.offset; i < tc.offset + tc.count; i++) {
532 struct netdev_queue *q = netdev_get_tx_queue(dev, i);
533 struct Qdisc *qdisc = rtnl_dereference(q->qdisc);
534 struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
535 struct gnet_stats_queue __percpu *cpu_qstats = NULL;
537 spin_lock_bh(qdisc_lock(qdisc));
538 if (qdisc_is_percpu_stats(qdisc)) {
539 cpu_bstats = qdisc->cpu_bstats;
540 cpu_qstats = qdisc->cpu_qstats;
543 qlen = qdisc_qlen_sum(qdisc);
544 __gnet_stats_copy_basic(NULL, &sch->bstats,
545 cpu_bstats, &qdisc->bstats);
546 __gnet_stats_copy_queue(&sch->qstats,
550 spin_unlock_bh(qdisc_lock(qdisc));
553 /* Reclaim root sleeping lock before completing stats */
555 spin_lock_bh(d->lock);
556 if (gnet_stats_copy_basic(NULL, d, NULL, &bstats) < 0 ||
557 gnet_stats_copy_queue(d, NULL, &qstats, qlen) < 0)
560 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
562 sch = dev_queue->qdisc_sleeping;
563 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d,
564 sch->cpu_bstats, &sch->bstats) < 0 ||
565 gnet_stats_copy_queue(d, NULL,
566 &sch->qstats, sch->q.qlen) < 0)
572 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
574 struct net_device *dev = qdisc_dev(sch);
580 /* Walk hierarchy with a virtual class per tc */
581 arg->count = arg->skip;
582 for (ntx = arg->skip; ntx < netdev_get_num_tc(dev); ntx++) {
583 if (arg->fn(sch, ntx + TC_H_MIN_PRIORITY, arg) < 0) {
590 /* Pad the values and skip over unused traffic classes */
591 if (ntx < TC_MAX_QUEUE) {
592 arg->count = TC_MAX_QUEUE;
596 /* Reset offset, sort out remaining per-queue qdiscs */
597 for (ntx -= TC_MAX_QUEUE; ntx < dev->num_tx_queues; ntx++) {
598 if (arg->fn(sch, ntx + 1, arg) < 0) {
606 static struct netdev_queue *mqprio_select_queue(struct Qdisc *sch,
609 return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
612 static const struct Qdisc_class_ops mqprio_class_ops = {
613 .graft = mqprio_graft,
617 .dump = mqprio_dump_class,
618 .dump_stats = mqprio_dump_class_stats,
619 .select_queue = mqprio_select_queue,
622 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {
623 .cl_ops = &mqprio_class_ops,
625 .priv_size = sizeof(struct mqprio_sched),
627 .destroy = mqprio_destroy,
628 .attach = mqprio_attach,
630 .owner = THIS_MODULE,
633 static int __init mqprio_module_init(void)
635 return register_qdisc(&mqprio_qdisc_ops);
638 static void __exit mqprio_module_exit(void)
640 unregister_qdisc(&mqprio_qdisc_ops);
643 module_init(mqprio_module_init);
644 module_exit(mqprio_module_exit);
646 MODULE_LICENSE("GPL");