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) | |
9a429c49 ED |
43 | __acquires(dev->queue_lock) |
44 | __acquires(dev->ingress_lock) | |
1da177e4 | 45 | { |
1da177e4 | 46 | spin_lock_bh(&dev->queue_lock); |
fd44de7c | 47 | spin_lock(&dev->ingress_lock); |
1da177e4 | 48 | } |
62e3ba1b | 49 | EXPORT_SYMBOL(qdisc_lock_tree); |
1da177e4 LT |
50 | |
51 | void qdisc_unlock_tree(struct net_device *dev) | |
9a429c49 ED |
52 | __releases(dev->ingress_lock) |
53 | __releases(dev->queue_lock) | |
1da177e4 | 54 | { |
fd44de7c | 55 | spin_unlock(&dev->ingress_lock); |
1da177e4 | 56 | spin_unlock_bh(&dev->queue_lock); |
1da177e4 | 57 | } |
62e3ba1b | 58 | EXPORT_SYMBOL(qdisc_unlock_tree); |
1da177e4 | 59 | |
c716a81a JHS |
60 | static inline int qdisc_qlen(struct Qdisc *q) |
61 | { | |
c716a81a JHS |
62 | return q->q.qlen; |
63 | } | |
64 | ||
6c1361a6 KK |
65 | static inline int dev_requeue_skb(struct sk_buff *skb, struct net_device *dev, |
66 | struct Qdisc *q) | |
c716a81a | 67 | { |
c716a81a JHS |
68 | if (unlikely(skb->next)) |
69 | dev->gso_skb = skb; | |
70 | else | |
71 | q->ops->requeue(skb, q); | |
6c1361a6 | 72 | |
c716a81a JHS |
73 | netif_schedule(dev); |
74 | return 0; | |
75 | } | |
76 | ||
6c1361a6 KK |
77 | static inline struct sk_buff *dev_dequeue_skb(struct net_device *dev, |
78 | struct Qdisc *q) | |
c716a81a | 79 | { |
6c1361a6 | 80 | struct sk_buff *skb; |
c716a81a | 81 | |
6c1361a6 | 82 | if ((skb = dev->gso_skb)) |
c716a81a JHS |
83 | dev->gso_skb = NULL; |
84 | else | |
85 | skb = q->dequeue(q); | |
86 | ||
87 | return skb; | |
88 | } | |
89 | ||
6c1361a6 KK |
90 | static inline int handle_dev_cpu_collision(struct sk_buff *skb, |
91 | struct net_device *dev, | |
92 | struct Qdisc *q) | |
c716a81a | 93 | { |
6c1361a6 | 94 | int ret; |
c716a81a | 95 | |
6c1361a6 KK |
96 | if (unlikely(dev->xmit_lock_owner == smp_processor_id())) { |
97 | /* | |
98 | * Same CPU holding the lock. It may be a transient | |
99 | * configuration error, when hard_start_xmit() recurses. We | |
100 | * detect it by checking xmit owner and drop the packet when | |
101 | * deadloop is detected. Return OK to try the next skb. | |
102 | */ | |
c716a81a | 103 | kfree_skb(skb); |
6c1361a6 KK |
104 | if (net_ratelimit()) |
105 | printk(KERN_WARNING "Dead loop on netdevice %s, " | |
106 | "fix it urgently!\n", dev->name); | |
107 | ret = qdisc_qlen(q); | |
108 | } else { | |
109 | /* | |
110 | * Another cpu is holding lock, requeue & delay xmits for | |
111 | * some time. | |
112 | */ | |
113 | __get_cpu_var(netdev_rx_stat).cpu_collision++; | |
114 | ret = dev_requeue_skb(skb, dev, q); | |
c716a81a JHS |
115 | } |
116 | ||
6c1361a6 | 117 | return ret; |
c716a81a JHS |
118 | } |
119 | ||
10297b99 | 120 | /* |
6c1361a6 KK |
121 | * NOTE: Called under dev->queue_lock with locally disabled BH. |
122 | * | |
123 | * __LINK_STATE_QDISC_RUNNING guarantees only one CPU can process this | |
124 | * device at a time. dev->queue_lock serializes queue accesses for | |
125 | * this device AND dev->qdisc pointer itself. | |
126 | * | |
127 | * netif_tx_lock serializes accesses to device driver. | |
128 | * | |
129 | * dev->queue_lock and netif_tx_lock are mutually exclusive, | |
130 | * if one is grabbed, another must be free. | |
131 | * | |
132 | * Note, that this procedure can be called by a watchdog timer | |
133 | * | |
134 | * Returns to the caller: | |
135 | * 0 - queue is empty or throttled. | |
136 | * >0 - queue is not empty. | |
137 | * | |
138 | */ | |
48d83325 | 139 | static inline int qdisc_restart(struct net_device *dev) |
1da177e4 LT |
140 | { |
141 | struct Qdisc *q = dev->qdisc; | |
142 | struct sk_buff *skb; | |
5f1a485d | 143 | int ret = NETDEV_TX_BUSY; |
1da177e4 | 144 | |
6c1361a6 KK |
145 | /* Dequeue packet */ |
146 | if (unlikely((skb = dev_dequeue_skb(dev, q)) == NULL)) | |
c716a81a | 147 | return 0; |
f6a78bfc | 148 | |
6c1361a6 KK |
149 | |
150 | /* And release queue */ | |
c716a81a JHS |
151 | spin_unlock(&dev->queue_lock); |
152 | ||
8236632f | 153 | HARD_TX_LOCK(dev, smp_processor_id()); |
5f1a485d PWJ |
154 | if (!netif_subqueue_stopped(dev, skb)) |
155 | ret = dev_hard_start_xmit(skb, dev); | |
8236632f | 156 | HARD_TX_UNLOCK(dev); |
c716a81a JHS |
157 | |
158 | spin_lock(&dev->queue_lock); | |
c716a81a | 159 | q = dev->qdisc; |
c716a81a | 160 | |
6c1361a6 KK |
161 | switch (ret) { |
162 | case NETDEV_TX_OK: | |
163 | /* Driver sent out skb successfully */ | |
164 | ret = qdisc_qlen(q); | |
165 | break; | |
166 | ||
167 | case NETDEV_TX_LOCKED: | |
168 | /* Driver try lock failed */ | |
169 | ret = handle_dev_cpu_collision(skb, dev, q); | |
170 | break; | |
171 | ||
172 | default: | |
173 | /* Driver returned NETDEV_TX_BUSY - requeue skb */ | |
174 | if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit())) | |
175 | printk(KERN_WARNING "BUG %s code %d qlen %d\n", | |
176 | dev->name, ret, q->q.qlen); | |
177 | ||
178 | ret = dev_requeue_skb(skb, dev, q); | |
179 | break; | |
180 | } | |
c716a81a | 181 | |
6c1361a6 | 182 | return ret; |
1da177e4 LT |
183 | } |
184 | ||
48d83325 HX |
185 | void __qdisc_run(struct net_device *dev) |
186 | { | |
d90df3ad HX |
187 | do { |
188 | if (!qdisc_restart(dev)) | |
189 | break; | |
190 | } while (!netif_queue_stopped(dev)); | |
48d83325 HX |
191 | |
192 | clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); | |
193 | } | |
194 | ||
1da177e4 LT |
195 | static void dev_watchdog(unsigned long arg) |
196 | { | |
197 | struct net_device *dev = (struct net_device *)arg; | |
198 | ||
932ff279 | 199 | netif_tx_lock(dev); |
1da177e4 LT |
200 | if (dev->qdisc != &noop_qdisc) { |
201 | if (netif_device_present(dev) && | |
202 | netif_running(dev) && | |
203 | netif_carrier_ok(dev)) { | |
204 | if (netif_queue_stopped(dev) && | |
338f7566 SH |
205 | time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) { |
206 | ||
207 | printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", | |
208 | dev->name); | |
1da177e4 LT |
209 | dev->tx_timeout(dev); |
210 | } | |
f5a6e01c | 211 | if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) |
1da177e4 LT |
212 | dev_hold(dev); |
213 | } | |
214 | } | |
932ff279 | 215 | netif_tx_unlock(dev); |
1da177e4 LT |
216 | |
217 | dev_put(dev); | |
218 | } | |
219 | ||
1da177e4 LT |
220 | void __netdev_watchdog_up(struct net_device *dev) |
221 | { | |
222 | if (dev->tx_timeout) { | |
223 | if (dev->watchdog_timeo <= 0) | |
224 | dev->watchdog_timeo = 5*HZ; | |
60468d5b VP |
225 | if (!mod_timer(&dev->watchdog_timer, |
226 | round_jiffies(jiffies + dev->watchdog_timeo))) | |
1da177e4 LT |
227 | dev_hold(dev); |
228 | } | |
229 | } | |
230 | ||
231 | static void dev_watchdog_up(struct net_device *dev) | |
232 | { | |
1da177e4 | 233 | __netdev_watchdog_up(dev); |
1da177e4 LT |
234 | } |
235 | ||
236 | static void dev_watchdog_down(struct net_device *dev) | |
237 | { | |
932ff279 | 238 | netif_tx_lock_bh(dev); |
1da177e4 | 239 | if (del_timer(&dev->watchdog_timer)) |
15333061 | 240 | dev_put(dev); |
932ff279 | 241 | netif_tx_unlock_bh(dev); |
1da177e4 LT |
242 | } |
243 | ||
bea3348e SH |
244 | /** |
245 | * netif_carrier_on - set carrier | |
246 | * @dev: network device | |
247 | * | |
248 | * Device has detected that carrier. | |
249 | */ | |
0a242efc DV |
250 | void netif_carrier_on(struct net_device *dev) |
251 | { | |
bfaae0f0 | 252 | if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) { |
0a242efc | 253 | linkwatch_fire_event(dev); |
bfaae0f0 JG |
254 | if (netif_running(dev)) |
255 | __netdev_watchdog_up(dev); | |
256 | } | |
0a242efc | 257 | } |
62e3ba1b | 258 | EXPORT_SYMBOL(netif_carrier_on); |
0a242efc | 259 | |
bea3348e SH |
260 | /** |
261 | * netif_carrier_off - clear carrier | |
262 | * @dev: network device | |
263 | * | |
264 | * Device has detected loss of carrier. | |
265 | */ | |
0a242efc DV |
266 | void netif_carrier_off(struct net_device *dev) |
267 | { | |
268 | if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) | |
269 | linkwatch_fire_event(dev); | |
270 | } | |
62e3ba1b | 271 | EXPORT_SYMBOL(netif_carrier_off); |
0a242efc | 272 | |
1da177e4 LT |
273 | /* "NOOP" scheduler: the best scheduler, recommended for all interfaces |
274 | under all circumstances. It is difficult to invent anything faster or | |
275 | cheaper. | |
276 | */ | |
277 | ||
94df109a | 278 | static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc) |
1da177e4 LT |
279 | { |
280 | kfree_skb(skb); | |
281 | return NET_XMIT_CN; | |
282 | } | |
283 | ||
94df109a | 284 | static struct sk_buff *noop_dequeue(struct Qdisc * qdisc) |
1da177e4 LT |
285 | { |
286 | return NULL; | |
287 | } | |
288 | ||
94df109a | 289 | static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
1da177e4 LT |
290 | { |
291 | if (net_ratelimit()) | |
94df109a TG |
292 | printk(KERN_DEBUG "%s deferred output. It is buggy.\n", |
293 | skb->dev->name); | |
1da177e4 LT |
294 | kfree_skb(skb); |
295 | return NET_XMIT_CN; | |
296 | } | |
297 | ||
20fea08b | 298 | struct Qdisc_ops noop_qdisc_ops __read_mostly = { |
1da177e4 LT |
299 | .id = "noop", |
300 | .priv_size = 0, | |
301 | .enqueue = noop_enqueue, | |
302 | .dequeue = noop_dequeue, | |
303 | .requeue = noop_requeue, | |
304 | .owner = THIS_MODULE, | |
305 | }; | |
306 | ||
307 | struct Qdisc noop_qdisc = { | |
308 | .enqueue = noop_enqueue, | |
309 | .dequeue = noop_dequeue, | |
310 | .flags = TCQ_F_BUILTIN, | |
10297b99 | 311 | .ops = &noop_qdisc_ops, |
1da177e4 LT |
312 | .list = LIST_HEAD_INIT(noop_qdisc.list), |
313 | }; | |
62e3ba1b | 314 | EXPORT_SYMBOL(noop_qdisc); |
1da177e4 | 315 | |
20fea08b | 316 | static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = { |
1da177e4 LT |
317 | .id = "noqueue", |
318 | .priv_size = 0, | |
319 | .enqueue = noop_enqueue, | |
320 | .dequeue = noop_dequeue, | |
321 | .requeue = noop_requeue, | |
322 | .owner = THIS_MODULE, | |
323 | }; | |
324 | ||
325 | static struct Qdisc noqueue_qdisc = { | |
326 | .enqueue = NULL, | |
327 | .dequeue = noop_dequeue, | |
328 | .flags = TCQ_F_BUILTIN, | |
329 | .ops = &noqueue_qdisc_ops, | |
330 | .list = LIST_HEAD_INIT(noqueue_qdisc.list), | |
331 | }; | |
332 | ||
333 | ||
334 | static const u8 prio2band[TC_PRIO_MAX+1] = | |
335 | { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 }; | |
336 | ||
337 | /* 3-band FIFO queue: old style, but should be a bit faster than | |
338 | generic prio+fifo combination. | |
339 | */ | |
340 | ||
f87a9c3d TG |
341 | #define PFIFO_FAST_BANDS 3 |
342 | ||
321090e7 TG |
343 | static inline struct sk_buff_head *prio2list(struct sk_buff *skb, |
344 | struct Qdisc *qdisc) | |
1da177e4 LT |
345 | { |
346 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
321090e7 TG |
347 | return list + prio2band[skb->priority & TC_PRIO_MAX]; |
348 | } | |
1da177e4 | 349 | |
f87a9c3d | 350 | static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc) |
321090e7 TG |
351 | { |
352 | struct sk_buff_head *list = prio2list(skb, qdisc); | |
1da177e4 | 353 | |
821d24ae | 354 | if (skb_queue_len(list) < qdisc->dev->tx_queue_len) { |
1da177e4 | 355 | qdisc->q.qlen++; |
821d24ae | 356 | return __qdisc_enqueue_tail(skb, qdisc, list); |
1da177e4 | 357 | } |
821d24ae TG |
358 | |
359 | return qdisc_drop(skb, qdisc); | |
1da177e4 LT |
360 | } |
361 | ||
f87a9c3d | 362 | static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc) |
1da177e4 LT |
363 | { |
364 | int prio; | |
365 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
1da177e4 | 366 | |
452f299d TG |
367 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
368 | if (!skb_queue_empty(list + prio)) { | |
1da177e4 | 369 | qdisc->q.qlen--; |
452f299d | 370 | return __qdisc_dequeue_head(qdisc, list + prio); |
1da177e4 LT |
371 | } |
372 | } | |
f87a9c3d | 373 | |
1da177e4 LT |
374 | return NULL; |
375 | } | |
376 | ||
f87a9c3d | 377 | static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
1da177e4 | 378 | { |
1da177e4 | 379 | qdisc->q.qlen++; |
321090e7 | 380 | return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc)); |
1da177e4 LT |
381 | } |
382 | ||
f87a9c3d | 383 | static void pfifo_fast_reset(struct Qdisc* qdisc) |
1da177e4 LT |
384 | { |
385 | int prio; | |
386 | struct sk_buff_head *list = qdisc_priv(qdisc); | |
387 | ||
f87a9c3d | 388 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
821d24ae TG |
389 | __qdisc_reset_queue(qdisc, list + prio); |
390 | ||
391 | qdisc->qstats.backlog = 0; | |
1da177e4 LT |
392 | qdisc->q.qlen = 0; |
393 | } | |
394 | ||
395 | static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb) | |
396 | { | |
f87a9c3d | 397 | struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS }; |
1da177e4 | 398 | |
1da177e4 | 399 | memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1); |
1e90474c | 400 | NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
1da177e4 LT |
401 | return skb->len; |
402 | ||
1e90474c | 403 | nla_put_failure: |
1da177e4 LT |
404 | return -1; |
405 | } | |
406 | ||
1e90474c | 407 | static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt) |
1da177e4 | 408 | { |
f87a9c3d | 409 | int prio; |
1da177e4 LT |
410 | struct sk_buff_head *list = qdisc_priv(qdisc); |
411 | ||
f87a9c3d TG |
412 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
413 | skb_queue_head_init(list + prio); | |
1da177e4 LT |
414 | |
415 | return 0; | |
416 | } | |
417 | ||
20fea08b | 418 | static struct Qdisc_ops pfifo_fast_ops __read_mostly = { |
1da177e4 | 419 | .id = "pfifo_fast", |
f87a9c3d | 420 | .priv_size = PFIFO_FAST_BANDS * sizeof(struct sk_buff_head), |
1da177e4 LT |
421 | .enqueue = pfifo_fast_enqueue, |
422 | .dequeue = pfifo_fast_dequeue, | |
423 | .requeue = pfifo_fast_requeue, | |
424 | .init = pfifo_fast_init, | |
425 | .reset = pfifo_fast_reset, | |
426 | .dump = pfifo_fast_dump, | |
427 | .owner = THIS_MODULE, | |
428 | }; | |
429 | ||
3d54b82f | 430 | struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) |
1da177e4 LT |
431 | { |
432 | void *p; | |
433 | struct Qdisc *sch; | |
3d54b82f TG |
434 | unsigned int size; |
435 | int err = -ENOBUFS; | |
1da177e4 LT |
436 | |
437 | /* ensure that the Qdisc and the private data are 32-byte aligned */ | |
3d54b82f TG |
438 | size = QDISC_ALIGN(sizeof(*sch)); |
439 | size += ops->priv_size + (QDISC_ALIGNTO - 1); | |
1da177e4 | 440 | |
0da974f4 | 441 | p = kzalloc(size, GFP_KERNEL); |
1da177e4 | 442 | if (!p) |
3d54b82f | 443 | goto errout; |
3d54b82f TG |
444 | sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); |
445 | sch->padded = (char *) sch - (char *) p; | |
1da177e4 LT |
446 | |
447 | INIT_LIST_HEAD(&sch->list); | |
448 | skb_queue_head_init(&sch->q); | |
449 | sch->ops = ops; | |
450 | sch->enqueue = ops->enqueue; | |
451 | sch->dequeue = ops->dequeue; | |
452 | sch->dev = dev; | |
453 | dev_hold(dev); | |
1da177e4 | 454 | atomic_set(&sch->refcnt, 1); |
3d54b82f TG |
455 | |
456 | return sch; | |
457 | errout: | |
458 | return ERR_PTR(-err); | |
459 | } | |
460 | ||
9f9afec4 PM |
461 | struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops, |
462 | unsigned int parentid) | |
3d54b82f TG |
463 | { |
464 | struct Qdisc *sch; | |
10297b99 | 465 | |
3d54b82f TG |
466 | sch = qdisc_alloc(dev, ops); |
467 | if (IS_ERR(sch)) | |
468 | goto errout; | |
fd44de7c | 469 | sch->stats_lock = &dev->queue_lock; |
9f9afec4 | 470 | sch->parent = parentid; |
3d54b82f | 471 | |
1da177e4 LT |
472 | if (!ops->init || ops->init(sch, NULL) == 0) |
473 | return sch; | |
474 | ||
0fbbeb1b | 475 | qdisc_destroy(sch); |
3d54b82f | 476 | errout: |
1da177e4 LT |
477 | return NULL; |
478 | } | |
62e3ba1b | 479 | EXPORT_SYMBOL(qdisc_create_dflt); |
1da177e4 LT |
480 | |
481 | /* Under dev->queue_lock and BH! */ | |
482 | ||
483 | void qdisc_reset(struct Qdisc *qdisc) | |
484 | { | |
20fea08b | 485 | const struct Qdisc_ops *ops = qdisc->ops; |
1da177e4 LT |
486 | |
487 | if (ops->reset) | |
488 | ops->reset(qdisc); | |
489 | } | |
62e3ba1b | 490 | EXPORT_SYMBOL(qdisc_reset); |
1da177e4 | 491 | |
10297b99 | 492 | /* this is the rcu callback function to clean up a qdisc when there |
1da177e4 LT |
493 | * are no further references to it */ |
494 | ||
495 | static void __qdisc_destroy(struct rcu_head *head) | |
496 | { | |
497 | struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu); | |
1da177e4 LT |
498 | kfree((char *) qdisc - qdisc->padded); |
499 | } | |
500 | ||
501 | /* Under dev->queue_lock and BH! */ | |
502 | ||
503 | void qdisc_destroy(struct Qdisc *qdisc) | |
504 | { | |
20fea08b | 505 | const struct Qdisc_ops *ops = qdisc->ops; |
1da177e4 LT |
506 | |
507 | if (qdisc->flags & TCQ_F_BUILTIN || | |
85670cc1 | 508 | !atomic_dec_and_test(&qdisc->refcnt)) |
1da177e4 LT |
509 | return; |
510 | ||
85670cc1 | 511 | list_del(&qdisc->list); |
85670cc1 | 512 | gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); |
85670cc1 PM |
513 | if (ops->reset) |
514 | ops->reset(qdisc); | |
515 | if (ops->destroy) | |
516 | ops->destroy(qdisc); | |
1da177e4 | 517 | |
85670cc1 PM |
518 | module_put(ops->owner); |
519 | dev_put(qdisc->dev); | |
1da177e4 LT |
520 | call_rcu(&qdisc->q_rcu, __qdisc_destroy); |
521 | } | |
62e3ba1b | 522 | EXPORT_SYMBOL(qdisc_destroy); |
1da177e4 LT |
523 | |
524 | void dev_activate(struct net_device *dev) | |
525 | { | |
526 | /* No queueing discipline is attached to device; | |
527 | create default one i.e. pfifo_fast for devices, | |
528 | which need queueing and noqueue_qdisc for | |
529 | virtual interfaces | |
530 | */ | |
531 | ||
532 | if (dev->qdisc_sleeping == &noop_qdisc) { | |
533 | struct Qdisc *qdisc; | |
534 | if (dev->tx_queue_len) { | |
9f9afec4 PM |
535 | qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops, |
536 | TC_H_ROOT); | |
1da177e4 LT |
537 | if (qdisc == NULL) { |
538 | printk(KERN_INFO "%s: activation failed\n", dev->name); | |
539 | return; | |
540 | } | |
1da177e4 | 541 | list_add_tail(&qdisc->list, &dev->qdisc_list); |
1da177e4 LT |
542 | } else { |
543 | qdisc = &noqueue_qdisc; | |
544 | } | |
1da177e4 | 545 | dev->qdisc_sleeping = qdisc; |
1da177e4 LT |
546 | } |
547 | ||
cacaddf5 TC |
548 | if (!netif_carrier_ok(dev)) |
549 | /* Delay activation until next carrier-on event */ | |
550 | return; | |
551 | ||
1da177e4 LT |
552 | spin_lock_bh(&dev->queue_lock); |
553 | rcu_assign_pointer(dev->qdisc, dev->qdisc_sleeping); | |
554 | if (dev->qdisc != &noqueue_qdisc) { | |
555 | dev->trans_start = jiffies; | |
556 | dev_watchdog_up(dev); | |
557 | } | |
558 | spin_unlock_bh(&dev->queue_lock); | |
559 | } | |
560 | ||
561 | void dev_deactivate(struct net_device *dev) | |
562 | { | |
563 | struct Qdisc *qdisc; | |
41a23b07 | 564 | struct sk_buff *skb; |
ce0e32e6 | 565 | int running; |
1da177e4 LT |
566 | |
567 | spin_lock_bh(&dev->queue_lock); | |
568 | qdisc = dev->qdisc; | |
569 | dev->qdisc = &noop_qdisc; | |
570 | ||
571 | qdisc_reset(qdisc); | |
572 | ||
41a23b07 HX |
573 | skb = dev->gso_skb; |
574 | dev->gso_skb = NULL; | |
1da177e4 LT |
575 | spin_unlock_bh(&dev->queue_lock); |
576 | ||
41a23b07 HX |
577 | kfree_skb(skb); |
578 | ||
1da177e4 LT |
579 | dev_watchdog_down(dev); |
580 | ||
ce0e32e6 | 581 | /* Wait for outstanding qdisc-less dev_queue_xmit calls. */ |
d4828d85 | 582 | synchronize_rcu(); |
1da177e4 | 583 | |
d4828d85 | 584 | /* Wait for outstanding qdisc_run calls. */ |
ce0e32e6 HX |
585 | do { |
586 | while (test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state)) | |
587 | yield(); | |
588 | ||
589 | /* | |
590 | * Double-check inside queue lock to ensure that all effects | |
591 | * of the queue run are visible when we return. | |
592 | */ | |
593 | spin_lock_bh(&dev->queue_lock); | |
594 | running = test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); | |
595 | spin_unlock_bh(&dev->queue_lock); | |
596 | ||
597 | /* | |
598 | * The running flag should never be set at this point because | |
599 | * we've already set dev->qdisc to noop_qdisc *inside* the same | |
600 | * pair of spin locks. That is, if any qdisc_run starts after | |
601 | * our initial test it should see the noop_qdisc and then | |
602 | * clear the RUNNING bit before dropping the queue lock. So | |
603 | * if it is set here then we've found a bug. | |
604 | */ | |
605 | } while (WARN_ON_ONCE(running)); | |
1da177e4 LT |
606 | } |
607 | ||
608 | void dev_init_scheduler(struct net_device *dev) | |
609 | { | |
610 | qdisc_lock_tree(dev); | |
611 | dev->qdisc = &noop_qdisc; | |
612 | dev->qdisc_sleeping = &noop_qdisc; | |
613 | INIT_LIST_HEAD(&dev->qdisc_list); | |
614 | qdisc_unlock_tree(dev); | |
615 | ||
b24b8a24 | 616 | setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev); |
1da177e4 LT |
617 | } |
618 | ||
619 | void dev_shutdown(struct net_device *dev) | |
620 | { | |
621 | struct Qdisc *qdisc; | |
622 | ||
623 | qdisc_lock_tree(dev); | |
624 | qdisc = dev->qdisc_sleeping; | |
625 | dev->qdisc = &noop_qdisc; | |
626 | dev->qdisc_sleeping = &noop_qdisc; | |
627 | qdisc_destroy(qdisc); | |
628 | #if defined(CONFIG_NET_SCH_INGRESS) || defined(CONFIG_NET_SCH_INGRESS_MODULE) | |
10297b99 | 629 | if ((qdisc = dev->qdisc_ingress) != NULL) { |
1da177e4 LT |
630 | dev->qdisc_ingress = NULL; |
631 | qdisc_destroy(qdisc); | |
10297b99 | 632 | } |
1da177e4 LT |
633 | #endif |
634 | BUG_TRAP(!timer_pending(&dev->watchdog_timer)); | |
635 | qdisc_unlock_tree(dev); | |
636 | } |