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 | ||
1da177e4 | 14 | #include <linux/bitops.h> |
1da177e4 LT |
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> | |
1da177e4 | 20 | #include <linux/errno.h> |
1da177e4 LT |
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> | |
1da177e4 LT |
27 | #include <net/pkt_sched.h> |
28 | ||
29 | /* Main transmission queue. */ | |
30 | ||
0463d4ae PM |
31 | /* Modifications to data participating in scheduling must be protected with |
32 | * dev->queue_lock spinlock. | |
33 | * | |
34 | * The idea is the following: | |
35 | * - enqueue, dequeue are serialized via top level device | |
36 | * spinlock dev->queue_lock. | |
fd44de7c PM |
37 | * - ingress filtering is serialized via top level device |
38 | * spinlock dev->ingress_lock. | |
0463d4ae | 39 | * - updates to tree and tree walking are only done under the rtnl mutex. |
1da177e4 | 40 | */ |
1da177e4 LT |
41 | |
42 | void qdisc_lock_tree(struct net_device *dev) | |
43 | { | |
1da177e4 | 44 | spin_lock_bh(&dev->queue_lock); |
fd44de7c | 45 | spin_lock(&dev->ingress_lock); |
1da177e4 LT |
46 | } |
47 | ||
48 | void qdisc_unlock_tree(struct net_device *dev) | |
49 | { | |
fd44de7c | 50 | spin_unlock(&dev->ingress_lock); |
1da177e4 | 51 | spin_unlock_bh(&dev->queue_lock); |
1da177e4 LT |
52 | } |
53 | ||
c716a81a JHS |
54 | static inline int qdisc_qlen(struct Qdisc *q) |
55 | { | |
c716a81a JHS |
56 | return q->q.qlen; |
57 | } | |
58 | ||
6c1361a6 KK |
59 | static inline int dev_requeue_skb(struct sk_buff *skb, struct net_device *dev, |
60 | struct Qdisc *q) | |
c716a81a | 61 | { |
c716a81a JHS |
62 | if (unlikely(skb->next)) |
63 | dev->gso_skb = skb; | |
64 | else | |
65 | q->ops->requeue(skb, q); | |
6c1361a6 | 66 | |
c716a81a JHS |
67 | netif_schedule(dev); |
68 | return 0; | |
69 | } | |
70 | ||
6c1361a6 KK |
71 | static inline struct sk_buff *dev_dequeue_skb(struct net_device *dev, |
72 | struct Qdisc *q) | |
c716a81a | 73 | { |
6c1361a6 | 74 | struct sk_buff *skb; |
c716a81a | 75 | |
6c1361a6 | 76 | if ((skb = dev->gso_skb)) |
c716a81a JHS |
77 | dev->gso_skb = NULL; |
78 | else | |
79 | skb = q->dequeue(q); | |
80 | ||
81 | return skb; | |
82 | } | |
83 | ||
6c1361a6 KK |
84 | static inline int handle_dev_cpu_collision(struct sk_buff *skb, |
85 | struct net_device *dev, | |
86 | struct Qdisc *q) | |
c716a81a | 87 | { |
6c1361a6 | 88 | int ret; |
c716a81a | 89 | |
6c1361a6 KK |
90 | if (unlikely(dev->xmit_lock_owner == smp_processor_id())) { |
91 | /* | |
92 | * Same CPU holding the lock. It may be a transient | |
93 | * configuration error, when hard_start_xmit() recurses. We | |
94 | * detect it by checking xmit owner and drop the packet when | |
95 | * deadloop is detected. Return OK to try the next skb. | |
96 | */ | |
c716a81a | 97 | kfree_skb(skb); |
6c1361a6 KK |
98 | if (net_ratelimit()) |
99 | printk(KERN_WARNING "Dead loop on netdevice %s, " | |
100 | "fix it urgently!\n", dev->name); | |
101 | ret = qdisc_qlen(q); | |
102 | } else { | |
103 | /* | |
104 | * Another cpu is holding lock, requeue & delay xmits for | |
105 | * some time. | |
106 | */ | |
107 | __get_cpu_var(netdev_rx_stat).cpu_collision++; | |
108 | ret = dev_requeue_skb(skb, dev, q); | |
c716a81a JHS |
109 | } |
110 | ||
6c1361a6 | 111 | return ret; |
c716a81a JHS |
112 | } |
113 | ||
10297b99 | 114 | /* |
6c1361a6 KK |
115 | * NOTE: Called under dev->queue_lock with locally disabled BH. |
116 | * | |
117 | * __LINK_STATE_QDISC_RUNNING guarantees only one CPU can process this | |
118 | * device at a time. dev->queue_lock serializes queue accesses for | |
119 | * this device AND dev->qdisc pointer itself. | |
120 | * | |
121 | * netif_tx_lock serializes accesses to device driver. | |
122 | * | |
123 | * dev->queue_lock and netif_tx_lock are mutually exclusive, | |
124 | * if one is grabbed, another must be free. | |
125 | * | |
126 | * Note, that this procedure can be called by a watchdog timer | |
127 | * | |
128 | * Returns to the caller: | |
129 | * 0 - queue is empty or throttled. | |
130 | * >0 - queue is not empty. | |
131 | * | |
132 | */ | |
48d83325 | 133 | static inline int qdisc_restart(struct net_device *dev) |
1da177e4 LT |
134 | { |
135 | struct Qdisc *q = dev->qdisc; | |
136 | struct sk_buff *skb; | |
6c1361a6 | 137 | unsigned lockless; |
c716a81a | 138 | int ret; |
1da177e4 | 139 | |
6c1361a6 KK |
140 | /* Dequeue packet */ |
141 | if (unlikely((skb = dev_dequeue_skb(dev, q)) == NULL)) | |
c716a81a | 142 | return 0; |
f6a78bfc | 143 | |
6c1361a6 KK |
144 | /* |
145 | * When the driver has LLTX set, it does its own locking in | |
146 | * start_xmit. These checks are worth it because even uncongested | |
147 | * locks can be quite expensive. The driver can do a trylock, as | |
148 | * is being done here; in case of lock contention it should return | |
149 | * NETDEV_TX_LOCKED and the packet will be requeued. | |
150 | */ | |
151 | lockless = (dev->features & NETIF_F_LLTX); | |
152 | ||
153 | if (!lockless && !netif_tx_trylock(dev)) { | |
154 | /* Another CPU grabbed the driver tx lock */ | |
155 | return handle_dev_cpu_collision(skb, dev, q); | |
1da177e4 | 156 | } |
6c1361a6 KK |
157 | |
158 | /* And release queue */ | |
c716a81a JHS |
159 | spin_unlock(&dev->queue_lock); |
160 | ||
e50c41b5 | 161 | ret = dev_hard_start_xmit(skb, dev); |
c716a81a JHS |
162 | |
163 | if (!lockless) | |
164 | netif_tx_unlock(dev); | |
165 | ||
166 | spin_lock(&dev->queue_lock); | |
c716a81a | 167 | q = dev->qdisc; |
c716a81a | 168 | |
6c1361a6 KK |
169 | switch (ret) { |
170 | case NETDEV_TX_OK: | |
171 | /* Driver sent out skb successfully */ | |
172 | ret = qdisc_qlen(q); | |
173 | break; | |
174 | ||
175 | case NETDEV_TX_LOCKED: | |
176 | /* Driver try lock failed */ | |
177 | ret = handle_dev_cpu_collision(skb, dev, q); | |
178 | break; | |
179 | ||
180 | default: | |
181 | /* Driver returned NETDEV_TX_BUSY - requeue skb */ | |
182 | if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit())) | |
183 | printk(KERN_WARNING "BUG %s code %d qlen %d\n", | |
184 | dev->name, ret, q->q.qlen); | |
185 | ||
186 | ret = dev_requeue_skb(skb, dev, q); | |
187 | break; | |
188 | } | |
c716a81a | 189 | |
6c1361a6 | 190 | return ret; |
1da177e4 LT |
191 | } |
192 | ||
48d83325 HX |
193 | void __qdisc_run(struct net_device *dev) |
194 | { | |
d90df3ad HX |
195 | do { |
196 | if (!qdisc_restart(dev)) | |
197 | break; | |
198 | } while (!netif_queue_stopped(dev)); | |
48d83325 HX |
199 | |
200 | clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); | |
201 | } | |
202 | ||
1da177e4 LT |
203 | static void dev_watchdog(unsigned long arg) |
204 | { | |
205 | struct net_device *dev = (struct net_device *)arg; | |
206 | ||
932ff279 | 207 | netif_tx_lock(dev); |
1da177e4 LT |
208 | if (dev->qdisc != &noop_qdisc) { |
209 | if (netif_device_present(dev) && | |
210 | netif_running(dev) && | |
211 | netif_carrier_ok(dev)) { | |
212 | if (netif_queue_stopped(dev) && | |
338f7566 SH |
213 | time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) { |
214 | ||
215 | printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", | |
216 | dev->name); | |
1da177e4 LT |
217 | dev->tx_timeout(dev); |
218 | } | |
f5a6e01c | 219 | if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) |
1da177e4 LT |
220 | dev_hold(dev); |
221 | } | |
222 | } | |
932ff279 | 223 | netif_tx_unlock(dev); |
1da177e4 LT |
224 | |
225 | dev_put(dev); | |
226 | } | |
227 | ||
228 | static void dev_watchdog_init(struct net_device *dev) | |
229 | { | |
230 | init_timer(&dev->watchdog_timer); | |
231 | dev->watchdog_timer.data = (unsigned long)dev; | |
232 | dev->watchdog_timer.function = dev_watchdog; | |
233 | } | |
234 | ||
235 | void __netdev_watchdog_up(struct net_device *dev) | |
236 | { | |
237 | if (dev->tx_timeout) { | |
238 | if (dev->watchdog_timeo <= 0) | |
239 | dev->watchdog_timeo = 5*HZ; | |
60468d5b VP |
240 | if (!mod_timer(&dev->watchdog_timer, |
241 | round_jiffies(jiffies + dev->watchdog_timeo))) | |
1da177e4 LT |
242 | dev_hold(dev); |
243 | } | |
244 | } | |
245 | ||
246 | static void dev_watchdog_up(struct net_device *dev) | |
247 | { | |
1da177e4 | 248 | __netdev_watchdog_up(dev); |
1da177e4 LT |
249 | } |
250 | ||
251 | static void dev_watchdog_down(struct net_device *dev) | |
252 | { | |
932ff279 | 253 | netif_tx_lock_bh(dev); |
1da177e4 | 254 | if (del_timer(&dev->watchdog_timer)) |
15333061 | 255 | dev_put(dev); |
932ff279 | 256 | netif_tx_unlock_bh(dev); |
1da177e4 LT |
257 | } |
258 | ||
bea3348e SH |
259 | /** |
260 | * netif_carrier_on - set carrier | |
261 | * @dev: network device | |
262 | * | |
263 | * Device has detected that carrier. | |
264 | */ | |
0a242efc DV |
265 | void netif_carrier_on(struct net_device *dev) |
266 | { | |
267 | if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) | |
268 | linkwatch_fire_event(dev); | |
269 | if (netif_running(dev)) | |
270 | __netdev_watchdog_up(dev); | |
271 | } | |
272 | ||
bea3348e SH |
273 | /** |
274 | * netif_carrier_off - clear carrier | |
275 | * @dev: network device | |
276 | * | |
277 | * Device has detected loss of carrier. | |
278 | */ | |
0a242efc DV |
279 | void netif_carrier_off(struct net_device *dev) |
280 | { | |
281 | if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) | |
282 | linkwatch_fire_event(dev); | |
283 | } | |
284 | ||
1da177e4 LT |
285 | /* "NOOP" scheduler: the best scheduler, recommended for all interfaces |
286 | under all circumstances. It is difficult to invent anything faster or | |
287 | cheaper. | |
288 | */ | |
289 | ||
94df109a | 290 | static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc) |
1da177e4 LT |
291 | { |
292 | kfree_skb(skb); | |
293 | return NET_XMIT_CN; | |
294 | } | |
295 | ||
94df109a | 296 | static struct sk_buff *noop_dequeue(struct Qdisc * qdisc) |
1da177e4 LT |
297 | { |
298 | return NULL; | |
299 | } | |
300 | ||
94df109a | 301 | static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
1da177e4 LT |
302 | { |
303 | if (net_ratelimit()) | |
94df109a TG |
304 | printk(KERN_DEBUG "%s deferred output. It is buggy.\n", |
305 | skb->dev->name); | |
1da177e4 LT |
306 | kfree_skb(skb); |
307 | return NET_XMIT_CN; | |
308 | } | |
309 | ||
310 | struct Qdisc_ops noop_qdisc_ops = { | |
1da177e4 LT |
311 | .id = "noop", |
312 | .priv_size = 0, | |
313 | .enqueue = noop_enqueue, | |
314 | .dequeue = noop_dequeue, | |
315 | .requeue = noop_requeue, | |
316 | .owner = THIS_MODULE, | |
317 | }; | |
318 | ||
319 | struct Qdisc noop_qdisc = { | |
320 | .enqueue = noop_enqueue, | |
321 | .dequeue = noop_dequeue, | |
322 | .flags = TCQ_F_BUILTIN, | |
10297b99 | 323 | .ops = &noop_qdisc_ops, |
1da177e4 LT |
324 | .list = LIST_HEAD_INIT(noop_qdisc.list), |
325 | }; | |
326 | ||
327 | static struct Qdisc_ops noqueue_qdisc_ops = { | |
1da177e4 LT |
328 | .id = "noqueue", |
329 | .priv_size = 0, | |
330 | .enqueue = noop_enqueue, | |
331 | .dequeue = noop_dequeue, | |
332 | .requeue = noop_requeue, | |
333 | .owner = THIS_MODULE, | |
334 | }; | |
335 | ||
336 | static struct Qdisc noqueue_qdisc = { | |
337 | .enqueue = NULL, | |
338 | .dequeue = noop_dequeue, | |
339 | .flags = TCQ_F_BUILTIN, | |
340 | .ops = &noqueue_qdisc_ops, | |
341 | .list = LIST_HEAD_INIT(noqueue_qdisc.list), | |
342 | }; | |
343 | ||
344 | ||
345 | static const u8 prio2band[TC_PRIO_MAX+1] = | |
346 | { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 }; | |
347 | ||
348 | /* 3-band FIFO queue: old style, but should be a bit faster than | |
349 | generic prio+fifo combination. | |
350 | */ | |
351 | ||
f87a9c3d TG |
352 | #define PFIFO_FAST_BANDS 3 |
353 | ||
321090e7 TG |
354 | static inline struct sk_buff_head *prio2list(struct sk_buff *skb, |
355 | struct Qdisc *qdisc) | |
1da177e4 LT |
356 | { |
357 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
321090e7 TG |
358 | return list + prio2band[skb->priority & TC_PRIO_MAX]; |
359 | } | |
1da177e4 | 360 | |
f87a9c3d | 361 | static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc) |
321090e7 TG |
362 | { |
363 | struct sk_buff_head *list = prio2list(skb, qdisc); | |
1da177e4 | 364 | |
821d24ae | 365 | if (skb_queue_len(list) < qdisc->dev->tx_queue_len) { |
1da177e4 | 366 | qdisc->q.qlen++; |
821d24ae | 367 | return __qdisc_enqueue_tail(skb, qdisc, list); |
1da177e4 | 368 | } |
821d24ae TG |
369 | |
370 | return qdisc_drop(skb, qdisc); | |
1da177e4 LT |
371 | } |
372 | ||
f87a9c3d | 373 | static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc) |
1da177e4 LT |
374 | { |
375 | int prio; | |
376 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
1da177e4 | 377 | |
452f299d TG |
378 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
379 | if (!skb_queue_empty(list + prio)) { | |
1da177e4 | 380 | qdisc->q.qlen--; |
452f299d | 381 | return __qdisc_dequeue_head(qdisc, list + prio); |
1da177e4 LT |
382 | } |
383 | } | |
f87a9c3d | 384 | |
1da177e4 LT |
385 | return NULL; |
386 | } | |
387 | ||
f87a9c3d | 388 | static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
1da177e4 | 389 | { |
1da177e4 | 390 | qdisc->q.qlen++; |
321090e7 | 391 | return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc)); |
1da177e4 LT |
392 | } |
393 | ||
f87a9c3d | 394 | static void pfifo_fast_reset(struct Qdisc* qdisc) |
1da177e4 LT |
395 | { |
396 | int prio; | |
397 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
398 | ||
f87a9c3d | 399 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
821d24ae TG |
400 | __qdisc_reset_queue(qdisc, list + prio); |
401 | ||
402 | qdisc->qstats.backlog = 0; | |
1da177e4 LT |
403 | qdisc->q.qlen = 0; |
404 | } | |
405 | ||
406 | static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb) | |
407 | { | |
f87a9c3d | 408 | struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS }; |
1da177e4 | 409 | |
1da177e4 LT |
410 | memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1); |
411 | RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); | |
412 | return skb->len; | |
413 | ||
414 | rtattr_failure: | |
1da177e4 LT |
415 | return -1; |
416 | } | |
417 | ||
418 | static int pfifo_fast_init(struct Qdisc *qdisc, struct rtattr *opt) | |
419 | { | |
f87a9c3d | 420 | int prio; |
1da177e4 LT |
421 | struct sk_buff_head *list = qdisc_priv(qdisc); |
422 | ||
f87a9c3d TG |
423 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
424 | skb_queue_head_init(list + prio); | |
1da177e4 LT |
425 | |
426 | return 0; | |
427 | } | |
428 | ||
429 | static struct Qdisc_ops pfifo_fast_ops = { | |
1da177e4 | 430 | .id = "pfifo_fast", |
f87a9c3d | 431 | .priv_size = PFIFO_FAST_BANDS * sizeof(struct sk_buff_head), |
1da177e4 LT |
432 | .enqueue = pfifo_fast_enqueue, |
433 | .dequeue = pfifo_fast_dequeue, | |
434 | .requeue = pfifo_fast_requeue, | |
435 | .init = pfifo_fast_init, | |
436 | .reset = pfifo_fast_reset, | |
437 | .dump = pfifo_fast_dump, | |
438 | .owner = THIS_MODULE, | |
439 | }; | |
440 | ||
3d54b82f | 441 | struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) |
1da177e4 LT |
442 | { |
443 | void *p; | |
444 | struct Qdisc *sch; | |
3d54b82f TG |
445 | unsigned int size; |
446 | int err = -ENOBUFS; | |
1da177e4 LT |
447 | |
448 | /* ensure that the Qdisc and the private data are 32-byte aligned */ | |
3d54b82f TG |
449 | size = QDISC_ALIGN(sizeof(*sch)); |
450 | size += ops->priv_size + (QDISC_ALIGNTO - 1); | |
1da177e4 | 451 | |
0da974f4 | 452 | p = kzalloc(size, GFP_KERNEL); |
1da177e4 | 453 | if (!p) |
3d54b82f | 454 | goto errout; |
3d54b82f TG |
455 | sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); |
456 | sch->padded = (char *) sch - (char *) p; | |
1da177e4 LT |
457 | |
458 | INIT_LIST_HEAD(&sch->list); | |
459 | skb_queue_head_init(&sch->q); | |
460 | sch->ops = ops; | |
461 | sch->enqueue = ops->enqueue; | |
462 | sch->dequeue = ops->dequeue; | |
463 | sch->dev = dev; | |
464 | dev_hold(dev); | |
1da177e4 | 465 | atomic_set(&sch->refcnt, 1); |
3d54b82f TG |
466 | |
467 | return sch; | |
468 | errout: | |
469 | return ERR_PTR(-err); | |
470 | } | |
471 | ||
9f9afec4 PM |
472 | struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops, |
473 | unsigned int parentid) | |
3d54b82f TG |
474 | { |
475 | struct Qdisc *sch; | |
10297b99 | 476 | |
3d54b82f TG |
477 | sch = qdisc_alloc(dev, ops); |
478 | if (IS_ERR(sch)) | |
479 | goto errout; | |
fd44de7c | 480 | sch->stats_lock = &dev->queue_lock; |
9f9afec4 | 481 | sch->parent = parentid; |
3d54b82f | 482 | |
1da177e4 LT |
483 | if (!ops->init || ops->init(sch, NULL) == 0) |
484 | return sch; | |
485 | ||
0fbbeb1b | 486 | qdisc_destroy(sch); |
3d54b82f | 487 | errout: |
1da177e4 LT |
488 | return NULL; |
489 | } | |
490 | ||
491 | /* Under dev->queue_lock and BH! */ | |
492 | ||
493 | void qdisc_reset(struct Qdisc *qdisc) | |
494 | { | |
495 | struct Qdisc_ops *ops = qdisc->ops; | |
496 | ||
497 | if (ops->reset) | |
498 | ops->reset(qdisc); | |
499 | } | |
500 | ||
10297b99 | 501 | /* this is the rcu callback function to clean up a qdisc when there |
1da177e4 LT |
502 | * are no further references to it */ |
503 | ||
504 | static void __qdisc_destroy(struct rcu_head *head) | |
505 | { | |
506 | struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu); | |
1da177e4 LT |
507 | kfree((char *) qdisc - qdisc->padded); |
508 | } | |
509 | ||
510 | /* Under dev->queue_lock and BH! */ | |
511 | ||
512 | void qdisc_destroy(struct Qdisc *qdisc) | |
513 | { | |
85670cc1 | 514 | struct Qdisc_ops *ops = qdisc->ops; |
1da177e4 LT |
515 | |
516 | if (qdisc->flags & TCQ_F_BUILTIN || | |
85670cc1 | 517 | !atomic_dec_and_test(&qdisc->refcnt)) |
1da177e4 LT |
518 | return; |
519 | ||
85670cc1 | 520 | list_del(&qdisc->list); |
85670cc1 | 521 | gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); |
85670cc1 PM |
522 | if (ops->reset) |
523 | ops->reset(qdisc); | |
524 | if (ops->destroy) | |
525 | ops->destroy(qdisc); | |
1da177e4 | 526 | |
85670cc1 PM |
527 | module_put(ops->owner); |
528 | dev_put(qdisc->dev); | |
1da177e4 LT |
529 | call_rcu(&qdisc->q_rcu, __qdisc_destroy); |
530 | } | |
531 | ||
532 | void dev_activate(struct net_device *dev) | |
533 | { | |
534 | /* No queueing discipline is attached to device; | |
535 | create default one i.e. pfifo_fast for devices, | |
536 | which need queueing and noqueue_qdisc for | |
537 | virtual interfaces | |
538 | */ | |
539 | ||
540 | if (dev->qdisc_sleeping == &noop_qdisc) { | |
541 | struct Qdisc *qdisc; | |
542 | if (dev->tx_queue_len) { | |
9f9afec4 PM |
543 | qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops, |
544 | TC_H_ROOT); | |
1da177e4 LT |
545 | if (qdisc == NULL) { |
546 | printk(KERN_INFO "%s: activation failed\n", dev->name); | |
547 | return; | |
548 | } | |
1da177e4 | 549 | list_add_tail(&qdisc->list, &dev->qdisc_list); |
1da177e4 LT |
550 | } else { |
551 | qdisc = &noqueue_qdisc; | |
552 | } | |
1da177e4 | 553 | dev->qdisc_sleeping = qdisc; |
1da177e4 LT |
554 | } |
555 | ||
cacaddf5 TC |
556 | if (!netif_carrier_ok(dev)) |
557 | /* Delay activation until next carrier-on event */ | |
558 | return; | |
559 | ||
1da177e4 LT |
560 | spin_lock_bh(&dev->queue_lock); |
561 | rcu_assign_pointer(dev->qdisc, dev->qdisc_sleeping); | |
562 | if (dev->qdisc != &noqueue_qdisc) { | |
563 | dev->trans_start = jiffies; | |
564 | dev_watchdog_up(dev); | |
565 | } | |
566 | spin_unlock_bh(&dev->queue_lock); | |
567 | } | |
568 | ||
569 | void dev_deactivate(struct net_device *dev) | |
570 | { | |
571 | struct Qdisc *qdisc; | |
41a23b07 | 572 | struct sk_buff *skb; |
1da177e4 LT |
573 | |
574 | spin_lock_bh(&dev->queue_lock); | |
575 | qdisc = dev->qdisc; | |
576 | dev->qdisc = &noop_qdisc; | |
577 | ||
578 | qdisc_reset(qdisc); | |
579 | ||
41a23b07 HX |
580 | skb = dev->gso_skb; |
581 | dev->gso_skb = NULL; | |
1da177e4 LT |
582 | spin_unlock_bh(&dev->queue_lock); |
583 | ||
41a23b07 HX |
584 | kfree_skb(skb); |
585 | ||
1da177e4 LT |
586 | dev_watchdog_down(dev); |
587 | ||
d4828d85 HX |
588 | /* Wait for outstanding dev_queue_xmit calls. */ |
589 | synchronize_rcu(); | |
1da177e4 | 590 | |
d4828d85 HX |
591 | /* Wait for outstanding qdisc_run calls. */ |
592 | while (test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state)) | |
593 | yield(); | |
1da177e4 LT |
594 | } |
595 | ||
596 | void dev_init_scheduler(struct net_device *dev) | |
597 | { | |
598 | qdisc_lock_tree(dev); | |
599 | dev->qdisc = &noop_qdisc; | |
600 | dev->qdisc_sleeping = &noop_qdisc; | |
601 | INIT_LIST_HEAD(&dev->qdisc_list); | |
602 | qdisc_unlock_tree(dev); | |
603 | ||
604 | dev_watchdog_init(dev); | |
605 | } | |
606 | ||
607 | void dev_shutdown(struct net_device *dev) | |
608 | { | |
609 | struct Qdisc *qdisc; | |
610 | ||
611 | qdisc_lock_tree(dev); | |
612 | qdisc = dev->qdisc_sleeping; | |
613 | dev->qdisc = &noop_qdisc; | |
614 | dev->qdisc_sleeping = &noop_qdisc; | |
615 | qdisc_destroy(qdisc); | |
616 | #if defined(CONFIG_NET_SCH_INGRESS) || defined(CONFIG_NET_SCH_INGRESS_MODULE) | |
10297b99 | 617 | if ((qdisc = dev->qdisc_ingress) != NULL) { |
1da177e4 LT |
618 | dev->qdisc_ingress = NULL; |
619 | qdisc_destroy(qdisc); | |
10297b99 | 620 | } |
1da177e4 LT |
621 | #endif |
622 | BUG_TRAP(!timer_pending(&dev->watchdog_timer)); | |
623 | qdisc_unlock_tree(dev); | |
624 | } | |
625 | ||
0a242efc DV |
626 | EXPORT_SYMBOL(netif_carrier_on); |
627 | EXPORT_SYMBOL(netif_carrier_off); | |
1da177e4 | 628 | EXPORT_SYMBOL(noop_qdisc); |
1da177e4 LT |
629 | EXPORT_SYMBOL(qdisc_create_dflt); |
630 | EXPORT_SYMBOL(qdisc_destroy); | |
631 | EXPORT_SYMBOL(qdisc_reset); | |
1da177e4 LT |
632 | EXPORT_SYMBOL(qdisc_lock_tree); |
633 | EXPORT_SYMBOL(qdisc_unlock_tree); |