2 * net/sched/sch_generic.c Generic packet scheduler routines.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * Jamal Hadi Salim, <hadi@cyberus.ca> 990601
14 #include <linux/bitops.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/sched.h>
19 #include <linux/string.h>
20 #include <linux/errno.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/init.h>
25 #include <linux/rcupdate.h>
26 #include <linux/list.h>
27 #include <linux/slab.h>
28 #include <linux/if_vlan.h>
29 #include <net/sch_generic.h>
30 #include <net/pkt_sched.h>
32 #include <trace/events/qdisc.h>
34 /* Qdisc to use by default */
35 const struct Qdisc_ops *default_qdisc_ops = &pfifo_fast_ops;
36 EXPORT_SYMBOL(default_qdisc_ops);
38 /* Main transmission queue. */
40 /* Modifications to data participating in scheduling must be protected with
41 * qdisc_lock(qdisc) spinlock.
43 * The idea is the following:
44 * - enqueue, dequeue are serialized via qdisc root lock
45 * - ingress filtering is also serialized via qdisc root lock
46 * - updates to tree and tree walking are only done under the rtnl mutex.
49 static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
53 qdisc_qstats_backlog_inc(q, skb);
54 q->q.qlen++; /* it's still part of the queue */
60 static void try_bulk_dequeue_skb(struct Qdisc *q,
62 const struct netdev_queue *txq,
65 int bytelimit = qdisc_avail_bulklimit(txq) - skb->len;
67 while (bytelimit > 0) {
68 struct sk_buff *nskb = q->dequeue(q);
73 bytelimit -= nskb->len; /* covers GSO len */
76 (*packets)++; /* GSO counts as one pkt */
81 /* This variant of try_bulk_dequeue_skb() makes sure
82 * all skbs in the chain are for the same txq
84 static void try_bulk_dequeue_skb_slow(struct Qdisc *q,
88 int mapping = skb_get_queue_mapping(skb);
96 if (unlikely(skb_get_queue_mapping(nskb) != mapping)) {
97 q->skb_bad_txq = nskb;
98 qdisc_qstats_backlog_inc(q, nskb);
109 /* Note that dequeue_skb can possibly return a SKB list (via skb->next).
110 * A requeued skb (via q->gso_skb) can also be a SKB list.
112 static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate,
115 struct sk_buff *skb = q->gso_skb;
116 const struct netdev_queue *txq = q->dev_queue;
120 /* skb in gso_skb were already validated */
122 /* check the reason of requeuing without tx lock first */
123 txq = skb_get_tx_queue(txq->dev, skb);
124 if (!netif_xmit_frozen_or_stopped(txq)) {
126 qdisc_qstats_backlog_dec(q, skb);
133 skb = q->skb_bad_txq;
135 /* check the reason of requeuing without tx lock first */
136 txq = skb_get_tx_queue(txq->dev, skb);
137 if (!netif_xmit_frozen_or_stopped(txq)) {
138 q->skb_bad_txq = NULL;
139 qdisc_qstats_backlog_dec(q, skb);
146 if (!(q->flags & TCQ_F_ONETXQUEUE) ||
147 !netif_xmit_frozen_or_stopped(txq))
151 if (qdisc_may_bulk(q))
152 try_bulk_dequeue_skb(q, skb, txq, packets);
154 try_bulk_dequeue_skb_slow(q, skb, packets);
157 trace_qdisc_dequeue(q, txq, *packets, skb);
162 * Transmit possibly several skbs, and handle the return status as
163 * required. Owning running seqcount bit guarantees that
164 * only one CPU can execute this function.
166 * Returns to the caller:
167 * 0 - queue is empty or throttled.
168 * >0 - queue is not empty.
170 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
171 struct net_device *dev, struct netdev_queue *txq,
172 spinlock_t *root_lock, bool validate)
174 int ret = NETDEV_TX_BUSY;
176 /* And release qdisc */
177 spin_unlock(root_lock);
179 /* Note that we validate skb (GSO, checksum, ...) outside of locks */
181 skb = validate_xmit_skb_list(skb, dev);
184 HARD_TX_LOCK(dev, txq, smp_processor_id());
185 if (!netif_xmit_frozen_or_stopped(txq))
186 skb = dev_hard_start_xmit(skb, dev, txq, &ret);
188 HARD_TX_UNLOCK(dev, txq);
190 spin_lock(root_lock);
191 return qdisc_qlen(q);
193 spin_lock(root_lock);
195 if (dev_xmit_complete(ret)) {
196 /* Driver sent out skb successfully or skb was consumed */
199 /* Driver returned NETDEV_TX_BUSY - requeue skb */
200 if (unlikely(ret != NETDEV_TX_BUSY))
201 net_warn_ratelimited("BUG %s code %d qlen %d\n",
202 dev->name, ret, q->q.qlen);
204 ret = dev_requeue_skb(skb, q);
207 if (ret && netif_xmit_frozen_or_stopped(txq))
214 * NOTE: Called under qdisc_lock(q) with locally disabled BH.
216 * running seqcount guarantees only one CPU can process
217 * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
220 * netif_tx_lock serializes accesses to device driver.
222 * qdisc_lock(q) and netif_tx_lock are mutually exclusive,
223 * if one is grabbed, another must be free.
225 * Note, that this procedure can be called by a watchdog timer
227 * Returns to the caller:
228 * 0 - queue is empty or throttled.
229 * >0 - queue is not empty.
232 static inline int qdisc_restart(struct Qdisc *q, int *packets)
234 struct netdev_queue *txq;
235 struct net_device *dev;
236 spinlock_t *root_lock;
241 skb = dequeue_skb(q, &validate, packets);
245 root_lock = qdisc_lock(q);
247 txq = skb_get_tx_queue(dev, skb);
249 return sch_direct_xmit(skb, q, dev, txq, root_lock, validate);
252 void __qdisc_run(struct Qdisc *q)
254 int quota = READ_ONCE(dev_tx_weight);
257 while (qdisc_restart(q, &packets)) {
259 * Ordered by possible occurrence: Postpone processing if
260 * 1. we've exceeded packet quota
261 * 2. another process needs the CPU;
264 if (quota <= 0 || need_resched()) {
273 unsigned long dev_trans_start(struct net_device *dev)
275 unsigned long val, res;
278 if (is_vlan_dev(dev))
279 dev = vlan_dev_real_dev(dev);
280 res = netdev_get_tx_queue(dev, 0)->trans_start;
281 for (i = 1; i < dev->num_tx_queues; i++) {
282 val = netdev_get_tx_queue(dev, i)->trans_start;
283 if (val && time_after(val, res))
289 EXPORT_SYMBOL(dev_trans_start);
291 static void dev_watchdog(unsigned long arg)
293 struct net_device *dev = (struct net_device *)arg;
296 if (!qdisc_tx_is_noop(dev)) {
297 if (netif_device_present(dev) &&
298 netif_running(dev) &&
299 netif_carrier_ok(dev)) {
300 int some_queue_timedout = 0;
302 unsigned long trans_start;
304 for (i = 0; i < dev->num_tx_queues; i++) {
305 struct netdev_queue *txq;
307 txq = netdev_get_tx_queue(dev, i);
308 trans_start = txq->trans_start;
309 if (netif_xmit_stopped(txq) &&
310 time_after(jiffies, (trans_start +
311 dev->watchdog_timeo))) {
312 some_queue_timedout = 1;
313 txq->trans_timeout++;
318 if (some_queue_timedout) {
319 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
320 dev->name, netdev_drivername(dev), i);
321 dev->netdev_ops->ndo_tx_timeout(dev);
323 if (!mod_timer(&dev->watchdog_timer,
324 round_jiffies(jiffies +
325 dev->watchdog_timeo)))
329 netif_tx_unlock(dev);
334 void __netdev_watchdog_up(struct net_device *dev)
336 if (dev->netdev_ops->ndo_tx_timeout) {
337 if (dev->watchdog_timeo <= 0)
338 dev->watchdog_timeo = 5*HZ;
339 if (!mod_timer(&dev->watchdog_timer,
340 round_jiffies(jiffies + dev->watchdog_timeo)))
344 EXPORT_SYMBOL_GPL(__netdev_watchdog_up);
346 static void dev_watchdog_up(struct net_device *dev)
348 __netdev_watchdog_up(dev);
351 static void dev_watchdog_down(struct net_device *dev)
353 netif_tx_lock_bh(dev);
354 if (del_timer(&dev->watchdog_timer))
356 netif_tx_unlock_bh(dev);
360 * netif_carrier_on - set carrier
361 * @dev: network device
363 * Device has detected that carrier.
365 void netif_carrier_on(struct net_device *dev)
367 if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
368 if (dev->reg_state == NETREG_UNINITIALIZED)
370 atomic_inc(&dev->carrier_changes);
371 linkwatch_fire_event(dev);
372 if (netif_running(dev))
373 __netdev_watchdog_up(dev);
376 EXPORT_SYMBOL(netif_carrier_on);
379 * netif_carrier_off - clear carrier
380 * @dev: network device
382 * Device has detected loss of carrier.
384 void netif_carrier_off(struct net_device *dev)
386 if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
387 if (dev->reg_state == NETREG_UNINITIALIZED)
389 atomic_inc(&dev->carrier_changes);
390 linkwatch_fire_event(dev);
393 EXPORT_SYMBOL(netif_carrier_off);
395 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
396 under all circumstances. It is difficult to invent anything faster or
400 static int noop_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
401 struct sk_buff **to_free)
403 __qdisc_drop(skb, to_free);
407 static struct sk_buff *noop_dequeue(struct Qdisc *qdisc)
412 struct Qdisc_ops noop_qdisc_ops __read_mostly = {
415 .enqueue = noop_enqueue,
416 .dequeue = noop_dequeue,
417 .peek = noop_dequeue,
418 .owner = THIS_MODULE,
421 static struct netdev_queue noop_netdev_queue = {
422 .qdisc = &noop_qdisc,
423 .qdisc_sleeping = &noop_qdisc,
426 struct Qdisc noop_qdisc = {
427 .enqueue = noop_enqueue,
428 .dequeue = noop_dequeue,
429 .flags = TCQ_F_BUILTIN,
430 .ops = &noop_qdisc_ops,
431 .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
432 .dev_queue = &noop_netdev_queue,
433 .running = SEQCNT_ZERO(noop_qdisc.running),
434 .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
436 EXPORT_SYMBOL(noop_qdisc);
438 static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt)
440 /* register_qdisc() assigns a default of noop_enqueue if unset,
441 * but __dev_queue_xmit() treats noqueue only as such
442 * if this is NULL - so clear it here. */
443 qdisc->enqueue = NULL;
447 struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
450 .init = noqueue_init,
451 .enqueue = noop_enqueue,
452 .dequeue = noop_dequeue,
453 .peek = noop_dequeue,
454 .owner = THIS_MODULE,
457 static const u8 prio2band[TC_PRIO_MAX + 1] = {
458 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
461 /* 3-band FIFO queue: old style, but should be a bit faster than
462 generic prio+fifo combination.
465 #define PFIFO_FAST_BANDS 3
468 * Private data for a pfifo_fast scheduler containing:
469 * - queues for the three band
470 * - bitmap indicating which of the bands contain skbs
472 struct pfifo_fast_priv {
474 struct qdisc_skb_head q[PFIFO_FAST_BANDS];
478 * Convert a bitmap to the first band number where an skb is queued, where:
479 * bitmap=0 means there are no skbs on any band.
480 * bitmap=1 means there is an skb on band 0.
481 * bitmap=7 means there are skbs on all 3 bands, etc.
483 static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
485 static inline struct qdisc_skb_head *band2list(struct pfifo_fast_priv *priv,
488 return priv->q + band;
491 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
492 struct sk_buff **to_free)
494 if (qdisc->q.qlen < qdisc_dev(qdisc)->tx_queue_len) {
495 int band = prio2band[skb->priority & TC_PRIO_MAX];
496 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
497 struct qdisc_skb_head *list = band2list(priv, band);
499 priv->bitmap |= (1 << band);
501 return __qdisc_enqueue_tail(skb, qdisc, list);
504 return qdisc_drop(skb, qdisc, to_free);
507 static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
509 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
510 int band = bitmap2band[priv->bitmap];
512 if (likely(band >= 0)) {
513 struct qdisc_skb_head *qh = band2list(priv, band);
514 struct sk_buff *skb = __qdisc_dequeue_head(qh);
516 if (likely(skb != NULL)) {
517 qdisc_qstats_backlog_dec(qdisc, skb);
518 qdisc_bstats_update(qdisc, skb);
523 priv->bitmap &= ~(1 << band);
531 static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
533 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
534 int band = bitmap2band[priv->bitmap];
537 struct qdisc_skb_head *qh = band2list(priv, band);
545 static void pfifo_fast_reset(struct Qdisc *qdisc)
548 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
550 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
551 __qdisc_reset_queue(band2list(priv, prio));
554 qdisc->qstats.backlog = 0;
558 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
560 struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
562 memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
563 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
564 goto nla_put_failure;
571 static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
574 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
576 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
577 qdisc_skb_head_init(band2list(priv, prio));
579 /* Can by-pass the queue discipline */
580 qdisc->flags |= TCQ_F_CAN_BYPASS;
584 struct Qdisc_ops pfifo_fast_ops __read_mostly = {
586 .priv_size = sizeof(struct pfifo_fast_priv),
587 .enqueue = pfifo_fast_enqueue,
588 .dequeue = pfifo_fast_dequeue,
589 .peek = pfifo_fast_peek,
590 .init = pfifo_fast_init,
591 .reset = pfifo_fast_reset,
592 .dump = pfifo_fast_dump,
593 .owner = THIS_MODULE,
595 EXPORT_SYMBOL(pfifo_fast_ops);
597 static struct lock_class_key qdisc_tx_busylock;
598 static struct lock_class_key qdisc_running_key;
600 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
601 const struct Qdisc_ops *ops)
605 unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size;
607 struct net_device *dev = dev_queue->dev;
609 p = kzalloc_node(size, GFP_KERNEL,
610 netdev_queue_numa_node_read(dev_queue));
614 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
615 /* if we got non aligned memory, ask more and do alignment ourself */
618 p = kzalloc_node(size + QDISC_ALIGNTO - 1, GFP_KERNEL,
619 netdev_queue_numa_node_read(dev_queue));
622 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
623 sch->padded = (char *) sch - (char *) p;
625 qdisc_skb_head_init(&sch->q);
626 spin_lock_init(&sch->q.lock);
628 spin_lock_init(&sch->busylock);
629 lockdep_set_class(&sch->busylock,
630 dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
632 seqcount_init(&sch->running);
633 lockdep_set_class(&sch->running,
634 dev->qdisc_running_key ?: &qdisc_running_key);
637 sch->enqueue = ops->enqueue;
638 sch->dequeue = ops->dequeue;
639 sch->dev_queue = dev_queue;
641 refcount_set(&sch->refcnt, 1);
648 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
649 const struct Qdisc_ops *ops,
650 unsigned int parentid)
654 if (!try_module_get(ops->owner))
657 sch = qdisc_alloc(dev_queue, ops);
659 module_put(ops->owner);
662 sch->parent = parentid;
664 if (!ops->init || ops->init(sch, NULL) == 0)
670 EXPORT_SYMBOL(qdisc_create_dflt);
672 /* Under qdisc_lock(qdisc) and BH! */
674 void qdisc_reset(struct Qdisc *qdisc)
676 const struct Qdisc_ops *ops = qdisc->ops;
681 kfree_skb(qdisc->skb_bad_txq);
682 qdisc->skb_bad_txq = NULL;
684 if (qdisc->gso_skb) {
685 kfree_skb_list(qdisc->gso_skb);
686 qdisc->gso_skb = NULL;
689 qdisc->qstats.backlog = 0;
691 EXPORT_SYMBOL(qdisc_reset);
693 static void qdisc_rcu_free(struct rcu_head *head)
695 struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head);
697 if (qdisc_is_percpu_stats(qdisc)) {
698 free_percpu(qdisc->cpu_bstats);
699 free_percpu(qdisc->cpu_qstats);
702 kfree((char *) qdisc - qdisc->padded);
705 void qdisc_destroy(struct Qdisc *qdisc)
707 const struct Qdisc_ops *ops;
713 if (qdisc->flags & TCQ_F_BUILTIN ||
714 !refcount_dec_and_test(&qdisc->refcnt))
717 #ifdef CONFIG_NET_SCHED
718 qdisc_hash_del(qdisc);
720 qdisc_put_stab(rtnl_dereference(qdisc->stab));
722 gen_kill_estimator(&qdisc->rate_est);
728 module_put(ops->owner);
729 dev_put(qdisc_dev(qdisc));
731 kfree_skb_list(qdisc->gso_skb);
732 kfree_skb(qdisc->skb_bad_txq);
734 * gen_estimator est_timer() might access qdisc->q.lock,
735 * wait a RCU grace period before freeing qdisc.
737 call_rcu(&qdisc->rcu_head, qdisc_rcu_free);
739 EXPORT_SYMBOL(qdisc_destroy);
741 /* Attach toplevel qdisc to device queue. */
742 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
745 struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
746 spinlock_t *root_lock;
748 root_lock = qdisc_lock(oqdisc);
749 spin_lock_bh(root_lock);
751 /* ... and graft new one */
754 dev_queue->qdisc_sleeping = qdisc;
755 rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
757 spin_unlock_bh(root_lock);
761 EXPORT_SYMBOL(dev_graft_qdisc);
763 static void attach_one_default_qdisc(struct net_device *dev,
764 struct netdev_queue *dev_queue,
768 const struct Qdisc_ops *ops = default_qdisc_ops;
770 if (dev->priv_flags & IFF_NO_QUEUE)
771 ops = &noqueue_qdisc_ops;
773 qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT);
775 netdev_info(dev, "activation failed\n");
778 if (!netif_is_multiqueue(dev))
779 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
780 dev_queue->qdisc_sleeping = qdisc;
783 static void attach_default_qdiscs(struct net_device *dev)
785 struct netdev_queue *txq;
788 txq = netdev_get_tx_queue(dev, 0);
790 if (!netif_is_multiqueue(dev) ||
791 dev->priv_flags & IFF_NO_QUEUE) {
792 netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
793 dev->qdisc = txq->qdisc_sleeping;
794 qdisc_refcount_inc(dev->qdisc);
796 qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
799 qdisc->ops->attach(qdisc);
802 #ifdef CONFIG_NET_SCHED
803 if (dev->qdisc != &noop_qdisc)
804 qdisc_hash_add(dev->qdisc, false);
808 static void transition_one_qdisc(struct net_device *dev,
809 struct netdev_queue *dev_queue,
810 void *_need_watchdog)
812 struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
813 int *need_watchdog_p = _need_watchdog;
815 if (!(new_qdisc->flags & TCQ_F_BUILTIN))
816 clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
818 rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
819 if (need_watchdog_p) {
820 dev_queue->trans_start = 0;
821 *need_watchdog_p = 1;
825 void dev_activate(struct net_device *dev)
829 /* No queueing discipline is attached to device;
830 * create default one for devices, which need queueing
831 * and noqueue_qdisc for virtual interfaces
834 if (dev->qdisc == &noop_qdisc)
835 attach_default_qdiscs(dev);
837 if (!netif_carrier_ok(dev))
838 /* Delay activation until next carrier-on event */
842 netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
843 if (dev_ingress_queue(dev))
844 transition_one_qdisc(dev, dev_ingress_queue(dev), NULL);
847 netif_trans_update(dev);
848 dev_watchdog_up(dev);
851 EXPORT_SYMBOL(dev_activate);
853 static void dev_deactivate_queue(struct net_device *dev,
854 struct netdev_queue *dev_queue,
855 void *_qdisc_default)
857 struct Qdisc *qdisc_default = _qdisc_default;
860 qdisc = rtnl_dereference(dev_queue->qdisc);
862 spin_lock_bh(qdisc_lock(qdisc));
864 if (!(qdisc->flags & TCQ_F_BUILTIN))
865 set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
867 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
870 spin_unlock_bh(qdisc_lock(qdisc));
874 static bool some_qdisc_is_busy(struct net_device *dev)
878 for (i = 0; i < dev->num_tx_queues; i++) {
879 struct netdev_queue *dev_queue;
880 spinlock_t *root_lock;
884 dev_queue = netdev_get_tx_queue(dev, i);
885 q = dev_queue->qdisc_sleeping;
886 root_lock = qdisc_lock(q);
888 spin_lock_bh(root_lock);
890 val = (qdisc_is_running(q) ||
891 test_bit(__QDISC_STATE_SCHED, &q->state));
893 spin_unlock_bh(root_lock);
901 static void dev_qdisc_reset(struct net_device *dev,
902 struct netdev_queue *dev_queue,
905 struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
912 * dev_deactivate_many - deactivate transmissions on several devices
913 * @head: list of devices to deactivate
915 * This function returns only when all outstanding transmissions
916 * have completed, unless all devices are in dismantle phase.
918 void dev_deactivate_many(struct list_head *head)
920 struct net_device *dev;
922 list_for_each_entry(dev, head, close_list) {
923 netdev_for_each_tx_queue(dev, dev_deactivate_queue,
925 if (dev_ingress_queue(dev))
926 dev_deactivate_queue(dev, dev_ingress_queue(dev),
929 dev_watchdog_down(dev);
932 /* Wait for outstanding qdisc-less dev_queue_xmit calls.
933 * This is avoided if all devices are in dismantle phase :
934 * Caller will call synchronize_net() for us
938 /* Wait for outstanding qdisc_run calls. */
939 list_for_each_entry(dev, head, close_list) {
940 while (some_qdisc_is_busy(dev))
942 /* The new qdisc is assigned at this point so we can safely
943 * unwind stale skb lists and qdisc statistics
945 netdev_for_each_tx_queue(dev, dev_qdisc_reset, NULL);
946 if (dev_ingress_queue(dev))
947 dev_qdisc_reset(dev, dev_ingress_queue(dev), NULL);
951 void dev_deactivate(struct net_device *dev)
955 list_add(&dev->close_list, &single);
956 dev_deactivate_many(&single);
959 EXPORT_SYMBOL(dev_deactivate);
961 static void dev_init_scheduler_queue(struct net_device *dev,
962 struct netdev_queue *dev_queue,
965 struct Qdisc *qdisc = _qdisc;
967 rcu_assign_pointer(dev_queue->qdisc, qdisc);
968 dev_queue->qdisc_sleeping = qdisc;
971 void dev_init_scheduler(struct net_device *dev)
973 dev->qdisc = &noop_qdisc;
974 netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
975 if (dev_ingress_queue(dev))
976 dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
978 setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
981 static void shutdown_scheduler_queue(struct net_device *dev,
982 struct netdev_queue *dev_queue,
983 void *_qdisc_default)
985 struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
986 struct Qdisc *qdisc_default = _qdisc_default;
989 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
990 dev_queue->qdisc_sleeping = qdisc_default;
992 qdisc_destroy(qdisc);
996 void dev_shutdown(struct net_device *dev)
998 netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
999 if (dev_ingress_queue(dev))
1000 shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
1001 qdisc_destroy(dev->qdisc);
1002 dev->qdisc = &noop_qdisc;
1004 WARN_ON(timer_pending(&dev->watchdog_timer));
1007 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1008 const struct tc_ratespec *conf,
1011 memset(r, 0, sizeof(*r));
1012 r->overhead = conf->overhead;
1014 r->rate_bytes_ps = max_t(u64, conf->rate, rate64);
1015 r->linklayer = (conf->linklayer & TC_LINKLAYER_MASK);
1018 * The deal here is to replace a divide by a reciprocal one
1019 * in fast path (a reciprocal divide is a multiply and a shift)
1021 * Normal formula would be :
1022 * time_in_ns = (NSEC_PER_SEC * len) / rate_bps
1024 * We compute mult/shift to use instead :
1025 * time_in_ns = (len * mult) >> shift;
1027 * We try to get the highest possible mult value for accuracy,
1028 * but have to make sure no overflows will ever happen.
1030 if (r->rate_bytes_ps > 0) {
1031 u64 factor = NSEC_PER_SEC;
1034 r->mult = div64_u64(factor, r->rate_bytes_ps);
1035 if (r->mult & (1U << 31) || factor & (1ULL << 63))
1042 EXPORT_SYMBOL(psched_ratecfg_precompute);