Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 <asm/uaccess.h> | |
15 | #include <asm/system.h> | |
16 | #include <linux/bitops.h> | |
1da177e4 LT |
17 | #include <linux/module.h> |
18 | #include <linux/types.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/sched.h> | |
21 | #include <linux/string.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/socket.h> | |
24 | #include <linux/sockios.h> | |
25 | #include <linux/in.h> | |
26 | #include <linux/errno.h> | |
27 | #include <linux/interrupt.h> | |
28 | #include <linux/netdevice.h> | |
29 | #include <linux/skbuff.h> | |
30 | #include <linux/rtnetlink.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/rcupdate.h> | |
33 | #include <linux/list.h> | |
34 | #include <net/sock.h> | |
35 | #include <net/pkt_sched.h> | |
36 | ||
37 | /* Main transmission queue. */ | |
38 | ||
39 | /* Main qdisc structure lock. | |
40 | ||
41 | However, modifications | |
42 | to data, participating in scheduling must be additionally | |
43 | protected with dev->queue_lock spinlock. | |
44 | ||
45 | The idea is the following: | |
46 | - enqueue, dequeue are serialized via top level device | |
47 | spinlock dev->queue_lock. | |
48 | - tree walking is protected by read_lock_bh(qdisc_tree_lock) | |
49 | and this lock is used only in process context. | |
50 | - updates to tree are made under rtnl semaphore or | |
51 | from softirq context (__qdisc_destroy rcu-callback) | |
52 | hence this lock needs local bh disabling. | |
53 | ||
54 | qdisc_tree_lock must be grabbed BEFORE dev->queue_lock! | |
55 | */ | |
56 | DEFINE_RWLOCK(qdisc_tree_lock); | |
57 | ||
58 | void qdisc_lock_tree(struct net_device *dev) | |
59 | { | |
60 | write_lock_bh(&qdisc_tree_lock); | |
61 | spin_lock_bh(&dev->queue_lock); | |
62 | } | |
63 | ||
64 | void qdisc_unlock_tree(struct net_device *dev) | |
65 | { | |
66 | spin_unlock_bh(&dev->queue_lock); | |
67 | write_unlock_bh(&qdisc_tree_lock); | |
68 | } | |
69 | ||
70 | /* | |
71 | dev->queue_lock serializes queue accesses for this device | |
72 | AND dev->qdisc pointer itself. | |
73 | ||
932ff279 | 74 | netif_tx_lock serializes accesses to device driver. |
1da177e4 | 75 | |
932ff279 | 76 | dev->queue_lock and netif_tx_lock are mutually exclusive, |
1da177e4 LT |
77 | if one is grabbed, another must be free. |
78 | */ | |
79 | ||
80 | ||
81 | /* Kick device. | |
82 | Note, that this procedure can be called by a watchdog timer, so that | |
83 | we do not check dev->tbusy flag here. | |
84 | ||
85 | Returns: 0 - queue is empty. | |
86 | >0 - queue is not empty, but throttled. | |
87 | <0 - queue is not empty. Device is throttled, if dev->tbusy != 0. | |
88 | ||
89 | NOTE: Called under dev->queue_lock with locally disabled BH. | |
90 | */ | |
91 | ||
48d83325 | 92 | static inline int qdisc_restart(struct net_device *dev) |
1da177e4 LT |
93 | { |
94 | struct Qdisc *q = dev->qdisc; | |
95 | struct sk_buff *skb; | |
96 | ||
97 | /* Dequeue packet */ | |
f6a78bfc | 98 | if (((skb = dev->gso_skb)) || ((skb = q->dequeue(q)))) { |
1da177e4 | 99 | unsigned nolock = (dev->features & NETIF_F_LLTX); |
f6a78bfc HX |
100 | |
101 | dev->gso_skb = NULL; | |
102 | ||
1da177e4 LT |
103 | /* |
104 | * When the driver has LLTX set it does its own locking | |
105 | * in start_xmit. No need to add additional overhead by | |
106 | * locking again. These checks are worth it because | |
107 | * even uncongested locks can be quite expensive. | |
108 | * The driver can do trylock like here too, in case | |
109 | * of lock congestion it should return -1 and the packet | |
110 | * will be requeued. | |
111 | */ | |
112 | if (!nolock) { | |
932ff279 | 113 | if (!netif_tx_trylock(dev)) { |
1da177e4 LT |
114 | collision: |
115 | /* So, someone grabbed the driver. */ | |
116 | ||
117 | /* It may be transient configuration error, | |
118 | when hard_start_xmit() recurses. We detect | |
119 | it by checking xmit owner and drop the | |
120 | packet when deadloop is detected. | |
121 | */ | |
122 | if (dev->xmit_lock_owner == smp_processor_id()) { | |
123 | kfree_skb(skb); | |
124 | if (net_ratelimit()) | |
125 | printk(KERN_DEBUG "Dead loop on netdevice %s, fix it urgently!\n", dev->name); | |
126 | return -1; | |
127 | } | |
128 | __get_cpu_var(netdev_rx_stat).cpu_collision++; | |
129 | goto requeue; | |
130 | } | |
1da177e4 LT |
131 | } |
132 | ||
133 | { | |
134 | /* And release queue */ | |
135 | spin_unlock(&dev->queue_lock); | |
136 | ||
137 | if (!netif_queue_stopped(dev)) { | |
138 | int ret; | |
1da177e4 | 139 | |
f6a78bfc | 140 | ret = dev_hard_start_xmit(skb, dev); |
1da177e4 LT |
141 | if (ret == NETDEV_TX_OK) { |
142 | if (!nolock) { | |
932ff279 | 143 | netif_tx_unlock(dev); |
1da177e4 LT |
144 | } |
145 | spin_lock(&dev->queue_lock); | |
146 | return -1; | |
147 | } | |
148 | if (ret == NETDEV_TX_LOCKED && nolock) { | |
149 | spin_lock(&dev->queue_lock); | |
150 | goto collision; | |
151 | } | |
152 | } | |
153 | ||
154 | /* NETDEV_TX_BUSY - we need to requeue */ | |
155 | /* Release the driver */ | |
156 | if (!nolock) { | |
932ff279 | 157 | netif_tx_unlock(dev); |
1da177e4 LT |
158 | } |
159 | spin_lock(&dev->queue_lock); | |
160 | q = dev->qdisc; | |
161 | } | |
162 | ||
163 | /* Device kicked us out :( | |
164 | This is possible in three cases: | |
165 | ||
166 | 0. driver is locked | |
167 | 1. fastroute is enabled | |
168 | 2. device cannot determine busy state | |
169 | before start of transmission (f.e. dialout) | |
170 | 3. device is buggy (ppp) | |
171 | */ | |
172 | ||
173 | requeue: | |
f6a78bfc HX |
174 | if (skb->next) |
175 | dev->gso_skb = skb; | |
176 | else | |
177 | q->ops->requeue(skb, q); | |
1da177e4 LT |
178 | netif_schedule(dev); |
179 | return 1; | |
180 | } | |
8cbe1d46 | 181 | BUG_ON((int) q->q.qlen < 0); |
1da177e4 LT |
182 | return q->q.qlen; |
183 | } | |
184 | ||
48d83325 HX |
185 | void __qdisc_run(struct net_device *dev) |
186 | { | |
d4828d85 HX |
187 | if (unlikely(dev->qdisc == &noop_qdisc)) |
188 | goto out; | |
189 | ||
48d83325 HX |
190 | while (qdisc_restart(dev) < 0 && !netif_queue_stopped(dev)) |
191 | /* NOTHING */; | |
192 | ||
d4828d85 | 193 | out: |
48d83325 HX |
194 | clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); |
195 | } | |
196 | ||
1da177e4 LT |
197 | static void dev_watchdog(unsigned long arg) |
198 | { | |
199 | struct net_device *dev = (struct net_device *)arg; | |
200 | ||
932ff279 | 201 | netif_tx_lock(dev); |
1da177e4 LT |
202 | if (dev->qdisc != &noop_qdisc) { |
203 | if (netif_device_present(dev) && | |
204 | netif_running(dev) && | |
205 | netif_carrier_ok(dev)) { | |
206 | if (netif_queue_stopped(dev) && | |
338f7566 SH |
207 | time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) { |
208 | ||
209 | printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", | |
210 | dev->name); | |
1da177e4 LT |
211 | dev->tx_timeout(dev); |
212 | } | |
213 | if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo)) | |
214 | dev_hold(dev); | |
215 | } | |
216 | } | |
932ff279 | 217 | netif_tx_unlock(dev); |
1da177e4 LT |
218 | |
219 | dev_put(dev); | |
220 | } | |
221 | ||
222 | static void dev_watchdog_init(struct net_device *dev) | |
223 | { | |
224 | init_timer(&dev->watchdog_timer); | |
225 | dev->watchdog_timer.data = (unsigned long)dev; | |
226 | dev->watchdog_timer.function = dev_watchdog; | |
227 | } | |
228 | ||
229 | void __netdev_watchdog_up(struct net_device *dev) | |
230 | { | |
231 | if (dev->tx_timeout) { | |
232 | if (dev->watchdog_timeo <= 0) | |
233 | dev->watchdog_timeo = 5*HZ; | |
234 | if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo)) | |
235 | dev_hold(dev); | |
236 | } | |
237 | } | |
238 | ||
239 | static void dev_watchdog_up(struct net_device *dev) | |
240 | { | |
932ff279 | 241 | netif_tx_lock_bh(dev); |
1da177e4 | 242 | __netdev_watchdog_up(dev); |
932ff279 | 243 | netif_tx_unlock_bh(dev); |
1da177e4 LT |
244 | } |
245 | ||
246 | static void dev_watchdog_down(struct net_device *dev) | |
247 | { | |
932ff279 | 248 | netif_tx_lock_bh(dev); |
1da177e4 | 249 | if (del_timer(&dev->watchdog_timer)) |
15333061 | 250 | dev_put(dev); |
932ff279 | 251 | netif_tx_unlock_bh(dev); |
1da177e4 LT |
252 | } |
253 | ||
0a242efc DV |
254 | void netif_carrier_on(struct net_device *dev) |
255 | { | |
256 | if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) | |
257 | linkwatch_fire_event(dev); | |
258 | if (netif_running(dev)) | |
259 | __netdev_watchdog_up(dev); | |
260 | } | |
261 | ||
262 | void netif_carrier_off(struct net_device *dev) | |
263 | { | |
264 | if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) | |
265 | linkwatch_fire_event(dev); | |
266 | } | |
267 | ||
1da177e4 LT |
268 | /* "NOOP" scheduler: the best scheduler, recommended for all interfaces |
269 | under all circumstances. It is difficult to invent anything faster or | |
270 | cheaper. | |
271 | */ | |
272 | ||
94df109a | 273 | static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc) |
1da177e4 LT |
274 | { |
275 | kfree_skb(skb); | |
276 | return NET_XMIT_CN; | |
277 | } | |
278 | ||
94df109a | 279 | static struct sk_buff *noop_dequeue(struct Qdisc * qdisc) |
1da177e4 LT |
280 | { |
281 | return NULL; | |
282 | } | |
283 | ||
94df109a | 284 | static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
1da177e4 LT |
285 | { |
286 | if (net_ratelimit()) | |
94df109a TG |
287 | printk(KERN_DEBUG "%s deferred output. It is buggy.\n", |
288 | skb->dev->name); | |
1da177e4 LT |
289 | kfree_skb(skb); |
290 | return NET_XMIT_CN; | |
291 | } | |
292 | ||
293 | struct Qdisc_ops noop_qdisc_ops = { | |
1da177e4 LT |
294 | .id = "noop", |
295 | .priv_size = 0, | |
296 | .enqueue = noop_enqueue, | |
297 | .dequeue = noop_dequeue, | |
298 | .requeue = noop_requeue, | |
299 | .owner = THIS_MODULE, | |
300 | }; | |
301 | ||
302 | struct Qdisc noop_qdisc = { | |
303 | .enqueue = noop_enqueue, | |
304 | .dequeue = noop_dequeue, | |
305 | .flags = TCQ_F_BUILTIN, | |
306 | .ops = &noop_qdisc_ops, | |
307 | .list = LIST_HEAD_INIT(noop_qdisc.list), | |
308 | }; | |
309 | ||
310 | static struct Qdisc_ops noqueue_qdisc_ops = { | |
1da177e4 LT |
311 | .id = "noqueue", |
312 | .priv_size = 0, | |
313 | .enqueue = noop_enqueue, | |
314 | .dequeue = noop_dequeue, | |
315 | .requeue = noop_requeue, | |
316 | .owner = THIS_MODULE, | |
317 | }; | |
318 | ||
319 | static struct Qdisc noqueue_qdisc = { | |
320 | .enqueue = NULL, | |
321 | .dequeue = noop_dequeue, | |
322 | .flags = TCQ_F_BUILTIN, | |
323 | .ops = &noqueue_qdisc_ops, | |
324 | .list = LIST_HEAD_INIT(noqueue_qdisc.list), | |
325 | }; | |
326 | ||
327 | ||
328 | static const u8 prio2band[TC_PRIO_MAX+1] = | |
329 | { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 }; | |
330 | ||
331 | /* 3-band FIFO queue: old style, but should be a bit faster than | |
332 | generic prio+fifo combination. | |
333 | */ | |
334 | ||
f87a9c3d TG |
335 | #define PFIFO_FAST_BANDS 3 |
336 | ||
321090e7 TG |
337 | static inline struct sk_buff_head *prio2list(struct sk_buff *skb, |
338 | struct Qdisc *qdisc) | |
1da177e4 LT |
339 | { |
340 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
321090e7 TG |
341 | return list + prio2band[skb->priority & TC_PRIO_MAX]; |
342 | } | |
1da177e4 | 343 | |
f87a9c3d | 344 | static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc) |
321090e7 TG |
345 | { |
346 | struct sk_buff_head *list = prio2list(skb, qdisc); | |
1da177e4 | 347 | |
821d24ae | 348 | if (skb_queue_len(list) < qdisc->dev->tx_queue_len) { |
1da177e4 | 349 | qdisc->q.qlen++; |
821d24ae | 350 | return __qdisc_enqueue_tail(skb, qdisc, list); |
1da177e4 | 351 | } |
821d24ae TG |
352 | |
353 | return qdisc_drop(skb, qdisc); | |
1da177e4 LT |
354 | } |
355 | ||
f87a9c3d | 356 | static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc) |
1da177e4 LT |
357 | { |
358 | int prio; | |
359 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
1da177e4 | 360 | |
452f299d TG |
361 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
362 | if (!skb_queue_empty(list + prio)) { | |
1da177e4 | 363 | qdisc->q.qlen--; |
452f299d | 364 | return __qdisc_dequeue_head(qdisc, list + prio); |
1da177e4 LT |
365 | } |
366 | } | |
f87a9c3d | 367 | |
1da177e4 LT |
368 | return NULL; |
369 | } | |
370 | ||
f87a9c3d | 371 | static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
1da177e4 | 372 | { |
1da177e4 | 373 | qdisc->q.qlen++; |
321090e7 | 374 | return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc)); |
1da177e4 LT |
375 | } |
376 | ||
f87a9c3d | 377 | static void pfifo_fast_reset(struct Qdisc* qdisc) |
1da177e4 LT |
378 | { |
379 | int prio; | |
380 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
381 | ||
f87a9c3d | 382 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
821d24ae TG |
383 | __qdisc_reset_queue(qdisc, list + prio); |
384 | ||
385 | qdisc->qstats.backlog = 0; | |
1da177e4 LT |
386 | qdisc->q.qlen = 0; |
387 | } | |
388 | ||
389 | static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb) | |
390 | { | |
f87a9c3d | 391 | struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS }; |
1da177e4 | 392 | |
1da177e4 LT |
393 | memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1); |
394 | RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); | |
395 | return skb->len; | |
396 | ||
397 | rtattr_failure: | |
1da177e4 LT |
398 | return -1; |
399 | } | |
400 | ||
401 | static int pfifo_fast_init(struct Qdisc *qdisc, struct rtattr *opt) | |
402 | { | |
f87a9c3d | 403 | int prio; |
1da177e4 LT |
404 | struct sk_buff_head *list = qdisc_priv(qdisc); |
405 | ||
f87a9c3d TG |
406 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
407 | skb_queue_head_init(list + prio); | |
1da177e4 LT |
408 | |
409 | return 0; | |
410 | } | |
411 | ||
412 | static struct Qdisc_ops pfifo_fast_ops = { | |
1da177e4 | 413 | .id = "pfifo_fast", |
f87a9c3d | 414 | .priv_size = PFIFO_FAST_BANDS * sizeof(struct sk_buff_head), |
1da177e4 LT |
415 | .enqueue = pfifo_fast_enqueue, |
416 | .dequeue = pfifo_fast_dequeue, | |
417 | .requeue = pfifo_fast_requeue, | |
418 | .init = pfifo_fast_init, | |
419 | .reset = pfifo_fast_reset, | |
420 | .dump = pfifo_fast_dump, | |
421 | .owner = THIS_MODULE, | |
422 | }; | |
423 | ||
3d54b82f | 424 | struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) |
1da177e4 LT |
425 | { |
426 | void *p; | |
427 | struct Qdisc *sch; | |
3d54b82f TG |
428 | unsigned int size; |
429 | int err = -ENOBUFS; | |
1da177e4 LT |
430 | |
431 | /* ensure that the Qdisc and the private data are 32-byte aligned */ | |
3d54b82f TG |
432 | size = QDISC_ALIGN(sizeof(*sch)); |
433 | size += ops->priv_size + (QDISC_ALIGNTO - 1); | |
1da177e4 LT |
434 | |
435 | p = kmalloc(size, GFP_KERNEL); | |
436 | if (!p) | |
3d54b82f | 437 | goto errout; |
1da177e4 | 438 | memset(p, 0, size); |
3d54b82f TG |
439 | sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); |
440 | sch->padded = (char *) sch - (char *) p; | |
1da177e4 LT |
441 | |
442 | INIT_LIST_HEAD(&sch->list); | |
443 | skb_queue_head_init(&sch->q); | |
444 | sch->ops = ops; | |
445 | sch->enqueue = ops->enqueue; | |
446 | sch->dequeue = ops->dequeue; | |
447 | sch->dev = dev; | |
448 | dev_hold(dev); | |
449 | sch->stats_lock = &dev->queue_lock; | |
450 | atomic_set(&sch->refcnt, 1); | |
3d54b82f TG |
451 | |
452 | return sch; | |
453 | errout: | |
454 | return ERR_PTR(-err); | |
455 | } | |
456 | ||
457 | struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops) | |
458 | { | |
459 | struct Qdisc *sch; | |
460 | ||
461 | sch = qdisc_alloc(dev, ops); | |
462 | if (IS_ERR(sch)) | |
463 | goto errout; | |
464 | ||
1da177e4 LT |
465 | if (!ops->init || ops->init(sch, NULL) == 0) |
466 | return sch; | |
467 | ||
0fbbeb1b | 468 | qdisc_destroy(sch); |
3d54b82f | 469 | errout: |
1da177e4 LT |
470 | return NULL; |
471 | } | |
472 | ||
473 | /* Under dev->queue_lock and BH! */ | |
474 | ||
475 | void qdisc_reset(struct Qdisc *qdisc) | |
476 | { | |
477 | struct Qdisc_ops *ops = qdisc->ops; | |
478 | ||
479 | if (ops->reset) | |
480 | ops->reset(qdisc); | |
481 | } | |
482 | ||
483 | /* this is the rcu callback function to clean up a qdisc when there | |
484 | * are no further references to it */ | |
485 | ||
486 | static void __qdisc_destroy(struct rcu_head *head) | |
487 | { | |
488 | struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu); | |
489 | struct Qdisc_ops *ops = qdisc->ops; | |
490 | ||
491 | #ifdef CONFIG_NET_ESTIMATOR | |
492 | gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); | |
493 | #endif | |
494 | write_lock(&qdisc_tree_lock); | |
495 | if (ops->reset) | |
496 | ops->reset(qdisc); | |
497 | if (ops->destroy) | |
498 | ops->destroy(qdisc); | |
499 | write_unlock(&qdisc_tree_lock); | |
500 | module_put(ops->owner); | |
501 | ||
502 | dev_put(qdisc->dev); | |
503 | kfree((char *) qdisc - qdisc->padded); | |
504 | } | |
505 | ||
506 | /* Under dev->queue_lock and BH! */ | |
507 | ||
508 | void qdisc_destroy(struct Qdisc *qdisc) | |
509 | { | |
510 | struct list_head cql = LIST_HEAD_INIT(cql); | |
511 | struct Qdisc *cq, *q, *n; | |
512 | ||
513 | if (qdisc->flags & TCQ_F_BUILTIN || | |
514 | !atomic_dec_and_test(&qdisc->refcnt)) | |
515 | return; | |
516 | ||
517 | if (!list_empty(&qdisc->list)) { | |
518 | if (qdisc->ops->cl_ops == NULL) | |
519 | list_del(&qdisc->list); | |
520 | else | |
521 | list_move(&qdisc->list, &cql); | |
522 | } | |
523 | ||
524 | /* unlink inner qdiscs from dev->qdisc_list immediately */ | |
525 | list_for_each_entry(cq, &cql, list) | |
526 | list_for_each_entry_safe(q, n, &qdisc->dev->qdisc_list, list) | |
527 | if (TC_H_MAJ(q->parent) == TC_H_MAJ(cq->handle)) { | |
528 | if (q->ops->cl_ops == NULL) | |
529 | list_del_init(&q->list); | |
530 | else | |
531 | list_move_tail(&q->list, &cql); | |
532 | } | |
533 | list_for_each_entry_safe(cq, n, &cql, list) | |
534 | list_del_init(&cq->list); | |
535 | ||
536 | call_rcu(&qdisc->q_rcu, __qdisc_destroy); | |
537 | } | |
538 | ||
539 | void dev_activate(struct net_device *dev) | |
540 | { | |
541 | /* No queueing discipline is attached to device; | |
542 | create default one i.e. pfifo_fast for devices, | |
543 | which need queueing and noqueue_qdisc for | |
544 | virtual interfaces | |
545 | */ | |
546 | ||
547 | if (dev->qdisc_sleeping == &noop_qdisc) { | |
548 | struct Qdisc *qdisc; | |
549 | if (dev->tx_queue_len) { | |
550 | qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops); | |
551 | if (qdisc == NULL) { | |
552 | printk(KERN_INFO "%s: activation failed\n", dev->name); | |
553 | return; | |
554 | } | |
555 | write_lock_bh(&qdisc_tree_lock); | |
556 | list_add_tail(&qdisc->list, &dev->qdisc_list); | |
557 | write_unlock_bh(&qdisc_tree_lock); | |
558 | } else { | |
559 | qdisc = &noqueue_qdisc; | |
560 | } | |
561 | write_lock_bh(&qdisc_tree_lock); | |
562 | dev->qdisc_sleeping = qdisc; | |
563 | write_unlock_bh(&qdisc_tree_lock); | |
564 | } | |
565 | ||
cacaddf5 TC |
566 | if (!netif_carrier_ok(dev)) |
567 | /* Delay activation until next carrier-on event */ | |
568 | return; | |
569 | ||
1da177e4 LT |
570 | spin_lock_bh(&dev->queue_lock); |
571 | rcu_assign_pointer(dev->qdisc, dev->qdisc_sleeping); | |
572 | if (dev->qdisc != &noqueue_qdisc) { | |
573 | dev->trans_start = jiffies; | |
574 | dev_watchdog_up(dev); | |
575 | } | |
576 | spin_unlock_bh(&dev->queue_lock); | |
577 | } | |
578 | ||
579 | void dev_deactivate(struct net_device *dev) | |
580 | { | |
581 | struct Qdisc *qdisc; | |
582 | ||
583 | spin_lock_bh(&dev->queue_lock); | |
584 | qdisc = dev->qdisc; | |
585 | dev->qdisc = &noop_qdisc; | |
586 | ||
587 | qdisc_reset(qdisc); | |
588 | ||
589 | spin_unlock_bh(&dev->queue_lock); | |
590 | ||
591 | dev_watchdog_down(dev); | |
592 | ||
d4828d85 HX |
593 | /* Wait for outstanding dev_queue_xmit calls. */ |
594 | synchronize_rcu(); | |
1da177e4 | 595 | |
d4828d85 HX |
596 | /* Wait for outstanding qdisc_run calls. */ |
597 | while (test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state)) | |
598 | yield(); | |
f6a78bfc HX |
599 | |
600 | if (dev->gso_skb) { | |
601 | kfree_skb(dev->gso_skb); | |
602 | dev->gso_skb = NULL; | |
603 | } | |
1da177e4 LT |
604 | } |
605 | ||
606 | void dev_init_scheduler(struct net_device *dev) | |
607 | { | |
608 | qdisc_lock_tree(dev); | |
609 | dev->qdisc = &noop_qdisc; | |
610 | dev->qdisc_sleeping = &noop_qdisc; | |
611 | INIT_LIST_HEAD(&dev->qdisc_list); | |
612 | qdisc_unlock_tree(dev); | |
613 | ||
614 | dev_watchdog_init(dev); | |
615 | } | |
616 | ||
617 | void dev_shutdown(struct net_device *dev) | |
618 | { | |
619 | struct Qdisc *qdisc; | |
620 | ||
621 | qdisc_lock_tree(dev); | |
622 | qdisc = dev->qdisc_sleeping; | |
623 | dev->qdisc = &noop_qdisc; | |
624 | dev->qdisc_sleeping = &noop_qdisc; | |
625 | qdisc_destroy(qdisc); | |
626 | #if defined(CONFIG_NET_SCH_INGRESS) || defined(CONFIG_NET_SCH_INGRESS_MODULE) | |
627 | if ((qdisc = dev->qdisc_ingress) != NULL) { | |
628 | dev->qdisc_ingress = NULL; | |
629 | qdisc_destroy(qdisc); | |
630 | } | |
631 | #endif | |
632 | BUG_TRAP(!timer_pending(&dev->watchdog_timer)); | |
633 | qdisc_unlock_tree(dev); | |
634 | } | |
635 | ||
636 | EXPORT_SYMBOL(__netdev_watchdog_up); | |
0a242efc DV |
637 | EXPORT_SYMBOL(netif_carrier_on); |
638 | EXPORT_SYMBOL(netif_carrier_off); | |
1da177e4 LT |
639 | EXPORT_SYMBOL(noop_qdisc); |
640 | EXPORT_SYMBOL(noop_qdisc_ops); | |
641 | EXPORT_SYMBOL(qdisc_create_dflt); | |
3d54b82f | 642 | EXPORT_SYMBOL(qdisc_alloc); |
1da177e4 LT |
643 | EXPORT_SYMBOL(qdisc_destroy); |
644 | EXPORT_SYMBOL(qdisc_reset); | |
1da177e4 LT |
645 | EXPORT_SYMBOL(qdisc_lock_tree); |
646 | EXPORT_SYMBOL(qdisc_unlock_tree); |