| 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 | * 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. |
| 37 | * - ingress filtering is serialized via top level device |
| 38 | * spinlock dev->ingress_lock. |
| 39 | * - updates to tree and tree walking are only done under the rtnl mutex. |
| 40 | */ |
| 41 | |
| 42 | void qdisc_lock_tree(struct net_device *dev) |
| 43 | { |
| 44 | spin_lock_bh(&dev->queue_lock); |
| 45 | spin_lock(&dev->ingress_lock); |
| 46 | } |
| 47 | |
| 48 | void qdisc_unlock_tree(struct net_device *dev) |
| 49 | { |
| 50 | spin_unlock(&dev->ingress_lock); |
| 51 | spin_unlock_bh(&dev->queue_lock); |
| 52 | } |
| 53 | |
| 54 | static inline int qdisc_qlen(struct Qdisc *q) |
| 55 | { |
| 56 | return q->q.qlen; |
| 57 | } |
| 58 | |
| 59 | static inline int dev_requeue_skb(struct sk_buff *skb, struct net_device *dev, |
| 60 | struct Qdisc *q) |
| 61 | { |
| 62 | if (unlikely(skb->next)) |
| 63 | dev->gso_skb = skb; |
| 64 | else |
| 65 | q->ops->requeue(skb, q); |
| 66 | |
| 67 | netif_schedule(dev); |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static inline struct sk_buff *dev_dequeue_skb(struct net_device *dev, |
| 72 | struct Qdisc *q) |
| 73 | { |
| 74 | struct sk_buff *skb; |
| 75 | |
| 76 | if ((skb = dev->gso_skb)) |
| 77 | dev->gso_skb = NULL; |
| 78 | else |
| 79 | skb = q->dequeue(q); |
| 80 | |
| 81 | return skb; |
| 82 | } |
| 83 | |
| 84 | static inline int handle_dev_cpu_collision(struct sk_buff *skb, |
| 85 | struct net_device *dev, |
| 86 | struct Qdisc *q) |
| 87 | { |
| 88 | int ret; |
| 89 | |
| 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 | */ |
| 97 | kfree_skb(skb); |
| 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); |
| 109 | } |
| 110 | |
| 111 | return ret; |
| 112 | } |
| 113 | |
| 114 | /* |
| 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 | */ |
| 133 | static inline int qdisc_restart(struct net_device *dev) |
| 134 | { |
| 135 | struct Qdisc *q = dev->qdisc; |
| 136 | struct sk_buff *skb; |
| 137 | unsigned lockless; |
| 138 | int ret; |
| 139 | |
| 140 | /* Dequeue packet */ |
| 141 | if (unlikely((skb = dev_dequeue_skb(dev, q)) == NULL)) |
| 142 | return 0; |
| 143 | |
| 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); |
| 156 | } |
| 157 | |
| 158 | /* And release queue */ |
| 159 | spin_unlock(&dev->queue_lock); |
| 160 | |
| 161 | ret = dev_hard_start_xmit(skb, dev); |
| 162 | |
| 163 | if (!lockless) |
| 164 | netif_tx_unlock(dev); |
| 165 | |
| 166 | spin_lock(&dev->queue_lock); |
| 167 | q = dev->qdisc; |
| 168 | |
| 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 | } |
| 189 | |
| 190 | return ret; |
| 191 | } |
| 192 | |
| 193 | void __qdisc_run(struct net_device *dev) |
| 194 | { |
| 195 | do { |
| 196 | if (!qdisc_restart(dev)) |
| 197 | break; |
| 198 | } while (!netif_queue_stopped(dev)); |
| 199 | |
| 200 | clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state); |
| 201 | } |
| 202 | |
| 203 | static void dev_watchdog(unsigned long arg) |
| 204 | { |
| 205 | struct net_device *dev = (struct net_device *)arg; |
| 206 | |
| 207 | netif_tx_lock(dev); |
| 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) && |
| 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); |
| 217 | dev->tx_timeout(dev); |
| 218 | } |
| 219 | if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) |
| 220 | dev_hold(dev); |
| 221 | } |
| 222 | } |
| 223 | netif_tx_unlock(dev); |
| 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; |
| 240 | if (!mod_timer(&dev->watchdog_timer, |
| 241 | round_jiffies(jiffies + dev->watchdog_timeo))) |
| 242 | dev_hold(dev); |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | static void dev_watchdog_up(struct net_device *dev) |
| 247 | { |
| 248 | __netdev_watchdog_up(dev); |
| 249 | } |
| 250 | |
| 251 | static void dev_watchdog_down(struct net_device *dev) |
| 252 | { |
| 253 | netif_tx_lock_bh(dev); |
| 254 | if (del_timer(&dev->watchdog_timer)) |
| 255 | dev_put(dev); |
| 256 | netif_tx_unlock_bh(dev); |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * netif_carrier_on - set carrier |
| 261 | * @dev: network device |
| 262 | * |
| 263 | * Device has detected that carrier. |
| 264 | */ |
| 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 | |
| 273 | /** |
| 274 | * netif_carrier_off - clear carrier |
| 275 | * @dev: network device |
| 276 | * |
| 277 | * Device has detected loss of carrier. |
| 278 | */ |
| 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 | |
| 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 | |
| 290 | static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc) |
| 291 | { |
| 292 | kfree_skb(skb); |
| 293 | return NET_XMIT_CN; |
| 294 | } |
| 295 | |
| 296 | static struct sk_buff *noop_dequeue(struct Qdisc * qdisc) |
| 297 | { |
| 298 | return NULL; |
| 299 | } |
| 300 | |
| 301 | static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
| 302 | { |
| 303 | if (net_ratelimit()) |
| 304 | printk(KERN_DEBUG "%s deferred output. It is buggy.\n", |
| 305 | skb->dev->name); |
| 306 | kfree_skb(skb); |
| 307 | return NET_XMIT_CN; |
| 308 | } |
| 309 | |
| 310 | struct Qdisc_ops noop_qdisc_ops = { |
| 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, |
| 323 | .ops = &noop_qdisc_ops, |
| 324 | .list = LIST_HEAD_INIT(noop_qdisc.list), |
| 325 | }; |
| 326 | |
| 327 | static struct Qdisc_ops noqueue_qdisc_ops = { |
| 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 | |
| 352 | #define PFIFO_FAST_BANDS 3 |
| 353 | |
| 354 | static inline struct sk_buff_head *prio2list(struct sk_buff *skb, |
| 355 | struct Qdisc *qdisc) |
| 356 | { |
| 357 | struct sk_buff_head *list = qdisc_priv(qdisc); |
| 358 | return list + prio2band[skb->priority & TC_PRIO_MAX]; |
| 359 | } |
| 360 | |
| 361 | static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc) |
| 362 | { |
| 363 | struct sk_buff_head *list = prio2list(skb, qdisc); |
| 364 | |
| 365 | if (skb_queue_len(list) < qdisc->dev->tx_queue_len) { |
| 366 | qdisc->q.qlen++; |
| 367 | return __qdisc_enqueue_tail(skb, qdisc, list); |
| 368 | } |
| 369 | |
| 370 | return qdisc_drop(skb, qdisc); |
| 371 | } |
| 372 | |
| 373 | static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc) |
| 374 | { |
| 375 | int prio; |
| 376 | struct sk_buff_head *list = qdisc_priv(qdisc); |
| 377 | |
| 378 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
| 379 | if (!skb_queue_empty(list + prio)) { |
| 380 | qdisc->q.qlen--; |
| 381 | return __qdisc_dequeue_head(qdisc, list + prio); |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | return NULL; |
| 386 | } |
| 387 | |
| 388 | static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc) |
| 389 | { |
| 390 | qdisc->q.qlen++; |
| 391 | return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc)); |
| 392 | } |
| 393 | |
| 394 | static void pfifo_fast_reset(struct Qdisc* qdisc) |
| 395 | { |
| 396 | int prio; |
| 397 | struct sk_buff_head *list = qdisc_priv(qdisc); |
| 398 | |
| 399 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
| 400 | __qdisc_reset_queue(qdisc, list + prio); |
| 401 | |
| 402 | qdisc->qstats.backlog = 0; |
| 403 | qdisc->q.qlen = 0; |
| 404 | } |
| 405 | |
| 406 | static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb) |
| 407 | { |
| 408 | struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS }; |
| 409 | |
| 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: |
| 415 | return -1; |
| 416 | } |
| 417 | |
| 418 | static int pfifo_fast_init(struct Qdisc *qdisc, struct rtattr *opt) |
| 419 | { |
| 420 | int prio; |
| 421 | struct sk_buff_head *list = qdisc_priv(qdisc); |
| 422 | |
| 423 | for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
| 424 | skb_queue_head_init(list + prio); |
| 425 | |
| 426 | return 0; |
| 427 | } |
| 428 | |
| 429 | static struct Qdisc_ops pfifo_fast_ops = { |
| 430 | .id = "pfifo_fast", |
| 431 | .priv_size = PFIFO_FAST_BANDS * sizeof(struct sk_buff_head), |
| 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 | |
| 441 | struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops) |
| 442 | { |
| 443 | void *p; |
| 444 | struct Qdisc *sch; |
| 445 | unsigned int size; |
| 446 | int err = -ENOBUFS; |
| 447 | |
| 448 | /* ensure that the Qdisc and the private data are 32-byte aligned */ |
| 449 | size = QDISC_ALIGN(sizeof(*sch)); |
| 450 | size += ops->priv_size + (QDISC_ALIGNTO - 1); |
| 451 | |
| 452 | p = kzalloc(size, GFP_KERNEL); |
| 453 | if (!p) |
| 454 | goto errout; |
| 455 | sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); |
| 456 | sch->padded = (char *) sch - (char *) p; |
| 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); |
| 465 | atomic_set(&sch->refcnt, 1); |
| 466 | |
| 467 | return sch; |
| 468 | errout: |
| 469 | return ERR_PTR(-err); |
| 470 | } |
| 471 | |
| 472 | struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops, |
| 473 | unsigned int parentid) |
| 474 | { |
| 475 | struct Qdisc *sch; |
| 476 | |
| 477 | sch = qdisc_alloc(dev, ops); |
| 478 | if (IS_ERR(sch)) |
| 479 | goto errout; |
| 480 | sch->stats_lock = &dev->queue_lock; |
| 481 | sch->parent = parentid; |
| 482 | |
| 483 | if (!ops->init || ops->init(sch, NULL) == 0) |
| 484 | return sch; |
| 485 | |
| 486 | qdisc_destroy(sch); |
| 487 | errout: |
| 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 | |
| 501 | /* this is the rcu callback function to clean up a qdisc when there |
| 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); |
| 507 | kfree((char *) qdisc - qdisc->padded); |
| 508 | } |
| 509 | |
| 510 | /* Under dev->queue_lock and BH! */ |
| 511 | |
| 512 | void qdisc_destroy(struct Qdisc *qdisc) |
| 513 | { |
| 514 | struct Qdisc_ops *ops = qdisc->ops; |
| 515 | |
| 516 | if (qdisc->flags & TCQ_F_BUILTIN || |
| 517 | !atomic_dec_and_test(&qdisc->refcnt)) |
| 518 | return; |
| 519 | |
| 520 | list_del(&qdisc->list); |
| 521 | gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); |
| 522 | if (ops->reset) |
| 523 | ops->reset(qdisc); |
| 524 | if (ops->destroy) |
| 525 | ops->destroy(qdisc); |
| 526 | |
| 527 | module_put(ops->owner); |
| 528 | dev_put(qdisc->dev); |
| 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) { |
| 543 | qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops, |
| 544 | TC_H_ROOT); |
| 545 | if (qdisc == NULL) { |
| 546 | printk(KERN_INFO "%s: activation failed\n", dev->name); |
| 547 | return; |
| 548 | } |
| 549 | list_add_tail(&qdisc->list, &dev->qdisc_list); |
| 550 | } else { |
| 551 | qdisc = &noqueue_qdisc; |
| 552 | } |
| 553 | dev->qdisc_sleeping = qdisc; |
| 554 | } |
| 555 | |
| 556 | if (!netif_carrier_ok(dev)) |
| 557 | /* Delay activation until next carrier-on event */ |
| 558 | return; |
| 559 | |
| 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; |
| 572 | struct sk_buff *skb; |
| 573 | |
| 574 | spin_lock_bh(&dev->queue_lock); |
| 575 | qdisc = dev->qdisc; |
| 576 | dev->qdisc = &noop_qdisc; |
| 577 | |
| 578 | qdisc_reset(qdisc); |
| 579 | |
| 580 | skb = dev->gso_skb; |
| 581 | dev->gso_skb = NULL; |
| 582 | spin_unlock_bh(&dev->queue_lock); |
| 583 | |
| 584 | kfree_skb(skb); |
| 585 | |
| 586 | dev_watchdog_down(dev); |
| 587 | |
| 588 | /* Wait for outstanding dev_queue_xmit calls. */ |
| 589 | synchronize_rcu(); |
| 590 | |
| 591 | /* Wait for outstanding qdisc_run calls. */ |
| 592 | while (test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state)) |
| 593 | yield(); |
| 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) |
| 617 | if ((qdisc = dev->qdisc_ingress) != NULL) { |
| 618 | dev->qdisc_ingress = NULL; |
| 619 | qdisc_destroy(qdisc); |
| 620 | } |
| 621 | #endif |
| 622 | BUG_TRAP(!timer_pending(&dev->watchdog_timer)); |
| 623 | qdisc_unlock_tree(dev); |
| 624 | } |
| 625 | |
| 626 | EXPORT_SYMBOL(netif_carrier_on); |
| 627 | EXPORT_SYMBOL(netif_carrier_off); |
| 628 | EXPORT_SYMBOL(noop_qdisc); |
| 629 | EXPORT_SYMBOL(qdisc_create_dflt); |
| 630 | EXPORT_SYMBOL(qdisc_destroy); |
| 631 | EXPORT_SYMBOL(qdisc_reset); |
| 632 | EXPORT_SYMBOL(qdisc_lock_tree); |
| 633 | EXPORT_SYMBOL(qdisc_unlock_tree); |