pkt_sched: Remove qdisc->ops->requeue() etc.
[linux-2.6.git] / net / sched / sch_generic.c
1 /*
2  * net/sched/sch_generic.c      Generic packet scheduler routines.
3  *
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.
8  *
9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  *              Jamal Hadi Salim, <hadi@cyberus.ca> 990601
11  *              - Ingress support
12  */
13
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 <net/pkt_sched.h>
28
29 /* Main transmission queue. */
30
31 /* Modifications to data participating in scheduling must be protected with
32  * qdisc_lock(qdisc) spinlock.
33  *
34  * The idea is the following:
35  * - enqueue, dequeue are serialized via qdisc root lock
36  * - ingress filtering is also serialized via qdisc root lock
37  * - updates to tree and tree walking are only done under the rtnl mutex.
38  */
39
40 static inline int qdisc_qlen(struct Qdisc *q)
41 {
42         return q->q.qlen;
43 }
44
45 static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
46 {
47         q->gso_skb = skb;
48         q->qstats.requeues++;
49         __netif_schedule(q);
50
51         return 0;
52 }
53
54 static inline struct sk_buff *dequeue_skb(struct Qdisc *q)
55 {
56         struct sk_buff *skb = q->gso_skb;
57
58         if (unlikely(skb)) {
59                 struct net_device *dev = qdisc_dev(q);
60                 struct netdev_queue *txq;
61
62                 /* check the reason of requeuing without tx lock first */
63                 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
64                 if (!netif_tx_queue_stopped(txq) && !netif_tx_queue_frozen(txq))
65                         q->gso_skb = NULL;
66                 else
67                         skb = NULL;
68         } else {
69                 skb = q->dequeue(q);
70         }
71
72         return skb;
73 }
74
75 static inline int handle_dev_cpu_collision(struct sk_buff *skb,
76                                            struct netdev_queue *dev_queue,
77                                            struct Qdisc *q)
78 {
79         int ret;
80
81         if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) {
82                 /*
83                  * Same CPU holding the lock. It may be a transient
84                  * configuration error, when hard_start_xmit() recurses. We
85                  * detect it by checking xmit owner and drop the packet when
86                  * deadloop is detected. Return OK to try the next skb.
87                  */
88                 kfree_skb(skb);
89                 if (net_ratelimit())
90                         printk(KERN_WARNING "Dead loop on netdevice %s, "
91                                "fix it urgently!\n", dev_queue->dev->name);
92                 ret = qdisc_qlen(q);
93         } else {
94                 /*
95                  * Another cpu is holding lock, requeue & delay xmits for
96                  * some time.
97                  */
98                 __get_cpu_var(netdev_rx_stat).cpu_collision++;
99                 ret = dev_requeue_skb(skb, q);
100         }
101
102         return ret;
103 }
104
105 /*
106  * NOTE: Called under qdisc_lock(q) with locally disabled BH.
107  *
108  * __QDISC_STATE_RUNNING guarantees only one CPU can process
109  * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
110  * this queue.
111  *
112  *  netif_tx_lock serializes accesses to device driver.
113  *
114  *  qdisc_lock(q) and netif_tx_lock are mutually exclusive,
115  *  if one is grabbed, another must be free.
116  *
117  * Note, that this procedure can be called by a watchdog timer
118  *
119  * Returns to the caller:
120  *                              0  - queue is empty or throttled.
121  *                              >0 - queue is not empty.
122  *
123  */
124 static inline int qdisc_restart(struct Qdisc *q)
125 {
126         struct netdev_queue *txq;
127         int ret = NETDEV_TX_BUSY;
128         struct net_device *dev;
129         spinlock_t *root_lock;
130         struct sk_buff *skb;
131
132         /* Dequeue packet */
133         if (unlikely((skb = dequeue_skb(q)) == NULL))
134                 return 0;
135
136         root_lock = qdisc_lock(q);
137
138         /* And release qdisc */
139         spin_unlock(root_lock);
140
141         dev = qdisc_dev(q);
142         txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
143
144         HARD_TX_LOCK(dev, txq, smp_processor_id());
145         if (!netif_tx_queue_stopped(txq) &&
146             !netif_tx_queue_frozen(txq))
147                 ret = dev_hard_start_xmit(skb, dev, txq);
148         HARD_TX_UNLOCK(dev, txq);
149
150         spin_lock(root_lock);
151
152         switch (ret) {
153         case NETDEV_TX_OK:
154                 /* Driver sent out skb successfully */
155                 ret = qdisc_qlen(q);
156                 break;
157
158         case NETDEV_TX_LOCKED:
159                 /* Driver try lock failed */
160                 ret = handle_dev_cpu_collision(skb, txq, q);
161                 break;
162
163         default:
164                 /* Driver returned NETDEV_TX_BUSY - requeue skb */
165                 if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit()))
166                         printk(KERN_WARNING "BUG %s code %d qlen %d\n",
167                                dev->name, ret, q->q.qlen);
168
169                 ret = dev_requeue_skb(skb, q);
170                 break;
171         }
172
173         if (ret && (netif_tx_queue_stopped(txq) ||
174                     netif_tx_queue_frozen(txq)))
175                 ret = 0;
176
177         return ret;
178 }
179
180 void __qdisc_run(struct Qdisc *q)
181 {
182         unsigned long start_time = jiffies;
183
184         while (qdisc_restart(q)) {
185                 /*
186                  * Postpone processing if
187                  * 1. another process needs the CPU;
188                  * 2. we've been doing it for too long.
189                  */
190                 if (need_resched() || jiffies != start_time) {
191                         __netif_schedule(q);
192                         break;
193                 }
194         }
195
196         clear_bit(__QDISC_STATE_RUNNING, &q->state);
197 }
198
199 static void dev_watchdog(unsigned long arg)
200 {
201         struct net_device *dev = (struct net_device *)arg;
202
203         netif_tx_lock(dev);
204         if (!qdisc_tx_is_noop(dev)) {
205                 if (netif_device_present(dev) &&
206                     netif_running(dev) &&
207                     netif_carrier_ok(dev)) {
208                         int some_queue_stopped = 0;
209                         unsigned int i;
210
211                         for (i = 0; i < dev->num_tx_queues; i++) {
212                                 struct netdev_queue *txq;
213
214                                 txq = netdev_get_tx_queue(dev, i);
215                                 if (netif_tx_queue_stopped(txq)) {
216                                         some_queue_stopped = 1;
217                                         break;
218                                 }
219                         }
220
221                         if (some_queue_stopped &&
222                             time_after(jiffies, (dev->trans_start +
223                                                  dev->watchdog_timeo))) {
224                                 char drivername[64];
225                                 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n",
226                                        dev->name, netdev_drivername(dev, drivername, 64));
227                                 dev->tx_timeout(dev);
228                         }
229                         if (!mod_timer(&dev->watchdog_timer,
230                                        round_jiffies(jiffies +
231                                                      dev->watchdog_timeo)))
232                                 dev_hold(dev);
233                 }
234         }
235         netif_tx_unlock(dev);
236
237         dev_put(dev);
238 }
239
240 void __netdev_watchdog_up(struct net_device *dev)
241 {
242         if (dev->tx_timeout) {
243                 if (dev->watchdog_timeo <= 0)
244                         dev->watchdog_timeo = 5*HZ;
245                 if (!mod_timer(&dev->watchdog_timer,
246                                round_jiffies(jiffies + dev->watchdog_timeo)))
247                         dev_hold(dev);
248         }
249 }
250
251 static void dev_watchdog_up(struct net_device *dev)
252 {
253         __netdev_watchdog_up(dev);
254 }
255
256 static void dev_watchdog_down(struct net_device *dev)
257 {
258         netif_tx_lock_bh(dev);
259         if (del_timer(&dev->watchdog_timer))
260                 dev_put(dev);
261         netif_tx_unlock_bh(dev);
262 }
263
264 /**
265  *      netif_carrier_on - set carrier
266  *      @dev: network device
267  *
268  * Device has detected that carrier.
269  */
270 void netif_carrier_on(struct net_device *dev)
271 {
272         if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
273                 linkwatch_fire_event(dev);
274                 if (netif_running(dev))
275                         __netdev_watchdog_up(dev);
276         }
277 }
278 EXPORT_SYMBOL(netif_carrier_on);
279
280 /**
281  *      netif_carrier_off - clear carrier
282  *      @dev: network device
283  *
284  * Device has detected loss of carrier.
285  */
286 void netif_carrier_off(struct net_device *dev)
287 {
288         if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state))
289                 linkwatch_fire_event(dev);
290 }
291 EXPORT_SYMBOL(netif_carrier_off);
292
293 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
294    under all circumstances. It is difficult to invent anything faster or
295    cheaper.
296  */
297
298 static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
299 {
300         kfree_skb(skb);
301         return NET_XMIT_CN;
302 }
303
304 static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
305 {
306         return NULL;
307 }
308
309 struct Qdisc_ops noop_qdisc_ops __read_mostly = {
310         .id             =       "noop",
311         .priv_size      =       0,
312         .enqueue        =       noop_enqueue,
313         .dequeue        =       noop_dequeue,
314         .peek           =       noop_dequeue,
315         .owner          =       THIS_MODULE,
316 };
317
318 static struct netdev_queue noop_netdev_queue = {
319         .qdisc          =       &noop_qdisc,
320         .qdisc_sleeping =       &noop_qdisc,
321 };
322
323 struct Qdisc noop_qdisc = {
324         .enqueue        =       noop_enqueue,
325         .dequeue        =       noop_dequeue,
326         .flags          =       TCQ_F_BUILTIN,
327         .ops            =       &noop_qdisc_ops,
328         .list           =       LIST_HEAD_INIT(noop_qdisc.list),
329         .q.lock         =       __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
330         .dev_queue      =       &noop_netdev_queue,
331 };
332 EXPORT_SYMBOL(noop_qdisc);
333
334 static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
335         .id             =       "noqueue",
336         .priv_size      =       0,
337         .enqueue        =       noop_enqueue,
338         .dequeue        =       noop_dequeue,
339         .peek           =       noop_dequeue,
340         .owner          =       THIS_MODULE,
341 };
342
343 static struct Qdisc noqueue_qdisc;
344 static struct netdev_queue noqueue_netdev_queue = {
345         .qdisc          =       &noqueue_qdisc,
346         .qdisc_sleeping =       &noqueue_qdisc,
347 };
348
349 static struct Qdisc noqueue_qdisc = {
350         .enqueue        =       NULL,
351         .dequeue        =       noop_dequeue,
352         .flags          =       TCQ_F_BUILTIN,
353         .ops            =       &noqueue_qdisc_ops,
354         .list           =       LIST_HEAD_INIT(noqueue_qdisc.list),
355         .q.lock         =       __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
356         .dev_queue      =       &noqueue_netdev_queue,
357 };
358
359
360 static const u8 prio2band[TC_PRIO_MAX+1] =
361         { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 };
362
363 /* 3-band FIFO queue: old style, but should be a bit faster than
364    generic prio+fifo combination.
365  */
366
367 #define PFIFO_FAST_BANDS 3
368
369 static inline struct sk_buff_head *prio2list(struct sk_buff *skb,
370                                              struct Qdisc *qdisc)
371 {
372         struct sk_buff_head *list = qdisc_priv(qdisc);
373         return list + prio2band[skb->priority & TC_PRIO_MAX];
374 }
375
376 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)
377 {
378         struct sk_buff_head *list = prio2list(skb, qdisc);
379
380         if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) {
381                 qdisc->q.qlen++;
382                 return __qdisc_enqueue_tail(skb, qdisc, list);
383         }
384
385         return qdisc_drop(skb, qdisc);
386 }
387
388 static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc)
389 {
390         int prio;
391         struct sk_buff_head *list = qdisc_priv(qdisc);
392
393         for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
394                 if (!skb_queue_empty(list + prio)) {
395                         qdisc->q.qlen--;
396                         return __qdisc_dequeue_head(qdisc, list + prio);
397                 }
398         }
399
400         return NULL;
401 }
402
403 static struct sk_buff *pfifo_fast_peek(struct Qdisc* qdisc)
404 {
405         int prio;
406         struct sk_buff_head *list = qdisc_priv(qdisc);
407
408         for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
409                 if (!skb_queue_empty(list + prio))
410                         return skb_peek(list + prio);
411         }
412
413         return NULL;
414 }
415
416 static void pfifo_fast_reset(struct Qdisc* qdisc)
417 {
418         int prio;
419         struct sk_buff_head *list = qdisc_priv(qdisc);
420
421         for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
422                 __qdisc_reset_queue(qdisc, list + prio);
423
424         qdisc->qstats.backlog = 0;
425         qdisc->q.qlen = 0;
426 }
427
428 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
429 {
430         struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
431
432         memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1);
433         NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
434         return skb->len;
435
436 nla_put_failure:
437         return -1;
438 }
439
440 static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
441 {
442         int prio;
443         struct sk_buff_head *list = qdisc_priv(qdisc);
444
445         for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
446                 skb_queue_head_init(list + prio);
447
448         return 0;
449 }
450
451 static struct Qdisc_ops pfifo_fast_ops __read_mostly = {
452         .id             =       "pfifo_fast",
453         .priv_size      =       PFIFO_FAST_BANDS * sizeof(struct sk_buff_head),
454         .enqueue        =       pfifo_fast_enqueue,
455         .dequeue        =       pfifo_fast_dequeue,
456         .peek           =       pfifo_fast_peek,
457         .init           =       pfifo_fast_init,
458         .reset          =       pfifo_fast_reset,
459         .dump           =       pfifo_fast_dump,
460         .owner          =       THIS_MODULE,
461 };
462
463 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
464                           struct Qdisc_ops *ops)
465 {
466         void *p;
467         struct Qdisc *sch;
468         unsigned int size;
469         int err = -ENOBUFS;
470
471         /* ensure that the Qdisc and the private data are 32-byte aligned */
472         size = QDISC_ALIGN(sizeof(*sch));
473         size += ops->priv_size + (QDISC_ALIGNTO - 1);
474
475         p = kzalloc(size, GFP_KERNEL);
476         if (!p)
477                 goto errout;
478         sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
479         sch->padded = (char *) sch - (char *) p;
480
481         INIT_LIST_HEAD(&sch->list);
482         skb_queue_head_init(&sch->q);
483         sch->ops = ops;
484         sch->enqueue = ops->enqueue;
485         sch->dequeue = ops->dequeue;
486         sch->dev_queue = dev_queue;
487         dev_hold(qdisc_dev(sch));
488         atomic_set(&sch->refcnt, 1);
489
490         return sch;
491 errout:
492         return ERR_PTR(err);
493 }
494
495 struct Qdisc * qdisc_create_dflt(struct net_device *dev,
496                                  struct netdev_queue *dev_queue,
497                                  struct Qdisc_ops *ops,
498                                  unsigned int parentid)
499 {
500         struct Qdisc *sch;
501
502         sch = qdisc_alloc(dev_queue, ops);
503         if (IS_ERR(sch))
504                 goto errout;
505         sch->parent = parentid;
506
507         if (!ops->init || ops->init(sch, NULL) == 0)
508                 return sch;
509
510         qdisc_destroy(sch);
511 errout:
512         return NULL;
513 }
514 EXPORT_SYMBOL(qdisc_create_dflt);
515
516 /* Under qdisc_lock(qdisc) and BH! */
517
518 void qdisc_reset(struct Qdisc *qdisc)
519 {
520         const struct Qdisc_ops *ops = qdisc->ops;
521
522         if (ops->reset)
523                 ops->reset(qdisc);
524
525         kfree_skb(qdisc->gso_skb);
526         qdisc->gso_skb = NULL;
527 }
528 EXPORT_SYMBOL(qdisc_reset);
529
530 void qdisc_destroy(struct Qdisc *qdisc)
531 {
532         const struct Qdisc_ops  *ops = qdisc->ops;
533
534         if (qdisc->flags & TCQ_F_BUILTIN ||
535             !atomic_dec_and_test(&qdisc->refcnt))
536                 return;
537
538 #ifdef CONFIG_NET_SCHED
539         qdisc_list_del(qdisc);
540
541         qdisc_put_stab(qdisc->stab);
542 #endif
543         gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
544         if (ops->reset)
545                 ops->reset(qdisc);
546         if (ops->destroy)
547                 ops->destroy(qdisc);
548
549         module_put(ops->owner);
550         dev_put(qdisc_dev(qdisc));
551
552         kfree_skb(qdisc->gso_skb);
553         kfree((char *) qdisc - qdisc->padded);
554 }
555 EXPORT_SYMBOL(qdisc_destroy);
556
557 static bool dev_all_qdisc_sleeping_noop(struct net_device *dev)
558 {
559         unsigned int i;
560
561         for (i = 0; i < dev->num_tx_queues; i++) {
562                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
563
564                 if (txq->qdisc_sleeping != &noop_qdisc)
565                         return false;
566         }
567         return true;
568 }
569
570 static void attach_one_default_qdisc(struct net_device *dev,
571                                      struct netdev_queue *dev_queue,
572                                      void *_unused)
573 {
574         struct Qdisc *qdisc;
575
576         if (dev->tx_queue_len) {
577                 qdisc = qdisc_create_dflt(dev, dev_queue,
578                                           &pfifo_fast_ops, TC_H_ROOT);
579                 if (!qdisc) {
580                         printk(KERN_INFO "%s: activation failed\n", dev->name);
581                         return;
582                 }
583         } else {
584                 qdisc =  &noqueue_qdisc;
585         }
586         dev_queue->qdisc_sleeping = qdisc;
587 }
588
589 static void transition_one_qdisc(struct net_device *dev,
590                                  struct netdev_queue *dev_queue,
591                                  void *_need_watchdog)
592 {
593         struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
594         int *need_watchdog_p = _need_watchdog;
595
596         if (!(new_qdisc->flags & TCQ_F_BUILTIN))
597                 clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
598
599         rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
600         if (need_watchdog_p && new_qdisc != &noqueue_qdisc)
601                 *need_watchdog_p = 1;
602 }
603
604 void dev_activate(struct net_device *dev)
605 {
606         int need_watchdog;
607
608         /* No queueing discipline is attached to device;
609            create default one i.e. pfifo_fast for devices,
610            which need queueing and noqueue_qdisc for
611            virtual interfaces
612          */
613
614         if (dev_all_qdisc_sleeping_noop(dev))
615                 netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
616
617         if (!netif_carrier_ok(dev))
618                 /* Delay activation until next carrier-on event */
619                 return;
620
621         need_watchdog = 0;
622         netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
623         transition_one_qdisc(dev, &dev->rx_queue, NULL);
624
625         if (need_watchdog) {
626                 dev->trans_start = jiffies;
627                 dev_watchdog_up(dev);
628         }
629 }
630
631 static void dev_deactivate_queue(struct net_device *dev,
632                                  struct netdev_queue *dev_queue,
633                                  void *_qdisc_default)
634 {
635         struct Qdisc *qdisc_default = _qdisc_default;
636         struct Qdisc *qdisc;
637
638         qdisc = dev_queue->qdisc;
639         if (qdisc) {
640                 spin_lock_bh(qdisc_lock(qdisc));
641
642                 if (!(qdisc->flags & TCQ_F_BUILTIN))
643                         set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
644
645                 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
646                 qdisc_reset(qdisc);
647
648                 spin_unlock_bh(qdisc_lock(qdisc));
649         }
650 }
651
652 static bool some_qdisc_is_busy(struct net_device *dev)
653 {
654         unsigned int i;
655
656         for (i = 0; i < dev->num_tx_queues; i++) {
657                 struct netdev_queue *dev_queue;
658                 spinlock_t *root_lock;
659                 struct Qdisc *q;
660                 int val;
661
662                 dev_queue = netdev_get_tx_queue(dev, i);
663                 q = dev_queue->qdisc_sleeping;
664                 root_lock = qdisc_lock(q);
665
666                 spin_lock_bh(root_lock);
667
668                 val = (test_bit(__QDISC_STATE_RUNNING, &q->state) ||
669                        test_bit(__QDISC_STATE_SCHED, &q->state));
670
671                 spin_unlock_bh(root_lock);
672
673                 if (val)
674                         return true;
675         }
676         return false;
677 }
678
679 void dev_deactivate(struct net_device *dev)
680 {
681         netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc);
682         dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc);
683
684         dev_watchdog_down(dev);
685
686         /* Wait for outstanding qdisc-less dev_queue_xmit calls. */
687         synchronize_rcu();
688
689         /* Wait for outstanding qdisc_run calls. */
690         while (some_qdisc_is_busy(dev))
691                 yield();
692 }
693
694 static void dev_init_scheduler_queue(struct net_device *dev,
695                                      struct netdev_queue *dev_queue,
696                                      void *_qdisc)
697 {
698         struct Qdisc *qdisc = _qdisc;
699
700         dev_queue->qdisc = qdisc;
701         dev_queue->qdisc_sleeping = qdisc;
702 }
703
704 void dev_init_scheduler(struct net_device *dev)
705 {
706         netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
707         dev_init_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
708
709         setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
710 }
711
712 static void shutdown_scheduler_queue(struct net_device *dev,
713                                      struct netdev_queue *dev_queue,
714                                      void *_qdisc_default)
715 {
716         struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
717         struct Qdisc *qdisc_default = _qdisc_default;
718
719         if (qdisc) {
720                 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
721                 dev_queue->qdisc_sleeping = qdisc_default;
722
723                 qdisc_destroy(qdisc);
724         }
725 }
726
727 void dev_shutdown(struct net_device *dev)
728 {
729         netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
730         shutdown_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
731         WARN_ON(timer_pending(&dev->watchdog_timer));
732 }