blob: 34dc598440a240c76b729d53cce8b90c18bfc78c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/bitops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/sched.h>
19#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090027#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <net/pkt_sched.h>
Eric Dumazet7fee2262010-05-11 23:19:48 +000029#include <net/dst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31/* Main transmission queue. */
32
Patrick McHardy0463d4a2007-04-16 17:02:10 -070033/* Modifications to data participating in scheduling must be protected with
David S. Miller5fb66222008-08-02 20:02:43 -070034 * qdisc_lock(qdisc) spinlock.
Patrick McHardy0463d4a2007-04-16 17:02:10 -070035 *
36 * The idea is the following:
David S. Millerc7e4f3b2008-07-16 03:22:39 -070037 * - enqueue, dequeue are serialized via qdisc root lock
38 * - ingress filtering is also serialized via qdisc root lock
Patrick McHardy0463d4a2007-04-16 17:02:10 -070039 * - updates to tree and tree walking are only done under the rtnl mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
David S. Miller37437bb2008-07-16 02:15:04 -070042static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070043{
Eric Dumazet7fee2262010-05-11 23:19:48 +000044 skb_dst_force(skb);
Jarek Poplawski62523522008-10-06 10:41:50 -070045 q->gso_skb = skb;
Jarek Poplawski53e91502008-10-08 11:36:22 -070046 q->qstats.requeues++;
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +000047 q->q.qlen++; /* it's still part of the queue */
David S. Miller37437bb2008-07-16 02:15:04 -070048 __netif_schedule(q);
Jarek Poplawski62523522008-10-06 10:41:50 -070049
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070050 return 0;
51}
52
David S. Millerd3b753d2008-07-15 20:14:35 -070053static inline struct sk_buff *dequeue_skb(struct Qdisc *q)
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070054{
Jarek Poplawski554794d2008-10-06 09:54:39 -070055 struct sk_buff *skb = q->gso_skb;
56
Jarek Poplawskiebf05982008-09-22 22:16:23 -070057 if (unlikely(skb)) {
58 struct net_device *dev = qdisc_dev(q);
59 struct netdev_queue *txq;
60
61 /* check the reason of requeuing without tx lock first */
62 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
Eric Dumazet5a0d2262010-11-23 10:42:02 +000063 if (!netif_tx_queue_frozen_or_stopped(txq)) {
Jarek Poplawski62523522008-10-06 10:41:50 -070064 q->gso_skb = NULL;
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +000065 q->q.qlen--;
66 } else
Jarek Poplawskiebf05982008-09-22 22:16:23 -070067 skb = NULL;
68 } else {
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070069 skb = q->dequeue(q);
Jarek Poplawskiebf05982008-09-22 22:16:23 -070070 }
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070071
72 return skb;
73}
74
Krishna Kumar6c1361a2007-06-24 19:56:09 -070075static inline int handle_dev_cpu_collision(struct sk_buff *skb,
David S. Miller970565b2008-07-08 23:10:33 -070076 struct netdev_queue *dev_queue,
Krishna Kumar6c1361a2007-06-24 19:56:09 -070077 struct Qdisc *q)
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070078{
Krishna Kumar6c1361a2007-06-24 19:56:09 -070079 int ret;
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070080
David S. Millerc773e842008-07-08 23:13:53 -070081 if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) {
Krishna Kumar6c1361a2007-06-24 19:56:09 -070082 /*
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 */
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070088 kfree_skb(skb);
Krishna Kumar6c1361a2007-06-24 19:56:09 -070089 if (net_ratelimit())
90 printk(KERN_WARNING "Dead loop on netdevice %s, "
David S. Millerc773e842008-07-08 23:13:53 -070091 "fix it urgently!\n", dev_queue->dev->name);
Krishna Kumar6c1361a2007-06-24 19:56:09 -070092 ret = qdisc_qlen(q);
93 } else {
94 /*
95 * Another cpu is holding lock, requeue & delay xmits for
96 * some time.
97 */
Eric Dumazetd6d9ca02010-07-19 10:48:49 +000098 __this_cpu_inc(softnet_data.cpu_collision);
David S. Miller37437bb2008-07-16 02:15:04 -070099 ret = dev_requeue_skb(skb, q);
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700100 }
101
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700102 return ret;
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700103}
104
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900105/*
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000106 * Transmit one skb, and handle the return status as required. Holding the
107 * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this
108 * function.
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700109 *
110 * Returns to the caller:
111 * 0 - queue is empty or throttled.
112 * >0 - queue is not empty.
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700113 */
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000114int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
115 struct net_device *dev, struct netdev_queue *txq,
116 spinlock_t *root_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
Peter P Waskiewicz Jr5f1a4852007-11-13 20:40:55 -0800118 int ret = NETDEV_TX_BUSY;
David S. Miller7698b4f2008-07-16 01:42:40 -0700119
120 /* And release qdisc */
121 spin_unlock(root_lock);
Herbert Xud90df3a2007-05-10 04:55:14 -0700122
David S. Millerc773e842008-07-08 23:13:53 -0700123 HARD_TX_LOCK(dev, txq, smp_processor_id());
Eric Dumazet5a0d2262010-11-23 10:42:02 +0000124 if (!netif_tx_queue_frozen_or_stopped(txq))
David S. Millerfd2ea0a2008-07-17 01:56:23 -0700125 ret = dev_hard_start_xmit(skb, dev, txq);
Patrick McHardy572a9d72009-11-10 06:14:14 +0000126
David S. Millerc773e842008-07-08 23:13:53 -0700127 HARD_TX_UNLOCK(dev, txq);
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700128
David S. Miller7698b4f2008-07-16 01:42:40 -0700129 spin_lock(root_lock);
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700130
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000131 if (dev_xmit_complete(ret)) {
132 /* Driver sent out skb successfully or skb was consumed */
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700133 ret = qdisc_qlen(q);
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000134 } else if (ret == NETDEV_TX_LOCKED) {
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700135 /* Driver try lock failed */
David S. Millereb6aafe2008-07-08 23:12:38 -0700136 ret = handle_dev_cpu_collision(skb, txq, q);
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000137 } else {
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700138 /* Driver returned NETDEV_TX_BUSY - requeue skb */
139 if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit()))
140 printk(KERN_WARNING "BUG %s code %d qlen %d\n",
141 dev->name, ret, q->q.qlen);
142
David S. Miller37437bb2008-07-16 02:15:04 -0700143 ret = dev_requeue_skb(skb, q);
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700144 }
145
Eric Dumazet5a0d2262010-11-23 10:42:02 +0000146 if (ret && netif_tx_queue_frozen_or_stopped(txq))
David S. Miller37437bb2008-07-16 02:15:04 -0700147 ret = 0;
148
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700149 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150}
151
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000152/*
153 * NOTE: Called under qdisc_lock(q) with locally disabled BH.
154 *
155 * __QDISC_STATE_RUNNING guarantees only one CPU can process
156 * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
157 * this queue.
158 *
159 * netif_tx_lock serializes accesses to device driver.
160 *
161 * qdisc_lock(q) and netif_tx_lock are mutually exclusive,
162 * if one is grabbed, another must be free.
163 *
164 * Note, that this procedure can be called by a watchdog timer
165 *
166 * Returns to the caller:
167 * 0 - queue is empty or throttled.
168 * >0 - queue is not empty.
169 *
170 */
171static inline int qdisc_restart(struct Qdisc *q)
172{
173 struct netdev_queue *txq;
174 struct net_device *dev;
175 spinlock_t *root_lock;
176 struct sk_buff *skb;
177
178 /* Dequeue packet */
179 skb = dequeue_skb(q);
180 if (unlikely(!skb))
181 return 0;
Eric Dumazet7fee2262010-05-11 23:19:48 +0000182 WARN_ON_ONCE(skb_dst_is_noref(skb));
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000183 root_lock = qdisc_lock(q);
184 dev = qdisc_dev(q);
185 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
186
187 return sch_direct_xmit(skb, q, dev, txq, root_lock);
188}
189
David S. Miller37437bb2008-07-16 02:15:04 -0700190void __qdisc_run(struct Qdisc *q)
Herbert Xu48d83322006-06-19 23:57:59 -0700191{
Herbert Xu2ba25062008-03-28 16:25:26 -0700192 unsigned long start_time = jiffies;
193
David S. Miller37437bb2008-07-16 02:15:04 -0700194 while (qdisc_restart(q)) {
Herbert Xu2ba25062008-03-28 16:25:26 -0700195 /*
196 * Postpone processing if
197 * 1. another process needs the CPU;
198 * 2. we've been doing it for too long.
199 */
200 if (need_resched() || jiffies != start_time) {
David S. Miller37437bb2008-07-16 02:15:04 -0700201 __netif_schedule(q);
Herbert Xu2ba25062008-03-28 16:25:26 -0700202 break;
203 }
204 }
Herbert Xu48d83322006-06-19 23:57:59 -0700205
Eric Dumazetbc135b22010-06-02 03:23:51 -0700206 qdisc_run_end(q);
Herbert Xu48d83322006-06-19 23:57:59 -0700207}
208
Eric Dumazet9d214932009-05-17 20:55:16 -0700209unsigned long dev_trans_start(struct net_device *dev)
210{
211 unsigned long val, res = dev->trans_start;
212 unsigned int i;
213
214 for (i = 0; i < dev->num_tx_queues; i++) {
215 val = netdev_get_tx_queue(dev, i)->trans_start;
216 if (val && time_after(val, res))
217 res = val;
218 }
219 dev->trans_start = res;
220 return res;
221}
222EXPORT_SYMBOL(dev_trans_start);
223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224static void dev_watchdog(unsigned long arg)
225{
226 struct net_device *dev = (struct net_device *)arg;
227
Herbert Xu932ff272006-06-09 12:20:56 -0700228 netif_tx_lock(dev);
David S. Millere8a04642008-07-17 00:34:19 -0700229 if (!qdisc_tx_is_noop(dev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 if (netif_device_present(dev) &&
231 netif_running(dev) &&
232 netif_carrier_ok(dev)) {
Eric Dumazet9d214932009-05-17 20:55:16 -0700233 int some_queue_timedout = 0;
David S. Millere8a04642008-07-17 00:34:19 -0700234 unsigned int i;
Eric Dumazet9d214932009-05-17 20:55:16 -0700235 unsigned long trans_start;
Stephen Hemminger338f7562006-05-16 15:02:12 -0700236
David S. Millere8a04642008-07-17 00:34:19 -0700237 for (i = 0; i < dev->num_tx_queues; i++) {
238 struct netdev_queue *txq;
239
240 txq = netdev_get_tx_queue(dev, i);
Eric Dumazet9d214932009-05-17 20:55:16 -0700241 /*
242 * old device drivers set dev->trans_start
243 */
244 trans_start = txq->trans_start ? : dev->trans_start;
245 if (netif_tx_queue_stopped(txq) &&
246 time_after(jiffies, (trans_start +
247 dev->watchdog_timeo))) {
248 some_queue_timedout = 1;
David S. Millere8a04642008-07-17 00:34:19 -0700249 break;
250 }
251 }
252
Eric Dumazet9d214932009-05-17 20:55:16 -0700253 if (some_queue_timedout) {
Arjan van de Ven6579e572008-07-21 13:31:48 -0700254 char drivername[64];
Eric Dumazet9d214932009-05-17 20:55:16 -0700255 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
256 dev->name, netdev_drivername(dev, drivername, 64), i);
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800257 dev->netdev_ops->ndo_tx_timeout(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 }
David S. Millere8a04642008-07-17 00:34:19 -0700259 if (!mod_timer(&dev->watchdog_timer,
260 round_jiffies(jiffies +
261 dev->watchdog_timeo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 dev_hold(dev);
263 }
264 }
Herbert Xu932ff272006-06-09 12:20:56 -0700265 netif_tx_unlock(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267 dev_put(dev);
268}
269
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270void __netdev_watchdog_up(struct net_device *dev)
271{
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800272 if (dev->netdev_ops->ndo_tx_timeout) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 if (dev->watchdog_timeo <= 0)
274 dev->watchdog_timeo = 5*HZ;
Venkatesh Pallipadi60468d52007-05-31 21:28:44 -0700275 if (!mod_timer(&dev->watchdog_timer,
276 round_jiffies(jiffies + dev->watchdog_timeo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 dev_hold(dev);
278 }
279}
280
281static void dev_watchdog_up(struct net_device *dev)
282{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 __netdev_watchdog_up(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284}
285
286static void dev_watchdog_down(struct net_device *dev)
287{
Herbert Xu932ff272006-06-09 12:20:56 -0700288 netif_tx_lock_bh(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 if (del_timer(&dev->watchdog_timer))
Stephen Hemminger15333062006-03-20 22:32:28 -0800290 dev_put(dev);
Herbert Xu932ff272006-06-09 12:20:56 -0700291 netif_tx_unlock_bh(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292}
293
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700294/**
295 * netif_carrier_on - set carrier
296 * @dev: network device
297 *
298 * Device has detected that carrier.
299 */
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700300void netif_carrier_on(struct net_device *dev)
301{
Jeff Garzikbfaae0f2007-10-17 23:26:43 -0700302 if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
David S. Millerb4730012008-11-19 15:33:54 -0800303 if (dev->reg_state == NETREG_UNINITIALIZED)
304 return;
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700305 linkwatch_fire_event(dev);
Jeff Garzikbfaae0f2007-10-17 23:26:43 -0700306 if (netif_running(dev))
307 __netdev_watchdog_up(dev);
308 }
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700309}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800310EXPORT_SYMBOL(netif_carrier_on);
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700311
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700312/**
313 * netif_carrier_off - clear carrier
314 * @dev: network device
315 *
316 * Device has detected loss of carrier.
317 */
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700318void netif_carrier_off(struct net_device *dev)
319{
David S. Millerb4730012008-11-19 15:33:54 -0800320 if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
321 if (dev->reg_state == NETREG_UNINITIALIZED)
322 return;
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700323 linkwatch_fire_event(dev);
David S. Millerb4730012008-11-19 15:33:54 -0800324 }
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700325}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800326EXPORT_SYMBOL(netif_carrier_off);
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700327
Ian Campbell06c46482010-05-26 00:09:42 +0000328/**
329 * netif_notify_peers - notify network peers about existence of @dev
330 * @dev: network device
331 *
332 * Generate traffic such that interested network peers are aware of
333 * @dev, such as by generating a gratuitous ARP. This may be used when
334 * a device wants to inform the rest of the network about some sort of
335 * reconfiguration such as a failover event or virtual machine
336 * migration.
337 */
338void netif_notify_peers(struct net_device *dev)
339{
340 rtnl_lock();
341 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
342 rtnl_unlock();
343}
344EXPORT_SYMBOL(netif_notify_peers);
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
347 under all circumstances. It is difficult to invent anything faster or
348 cheaper.
349 */
350
Thomas Graf94df1092005-06-18 22:59:08 -0700351static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352{
353 kfree_skb(skb);
354 return NET_XMIT_CN;
355}
356
Thomas Graf94df1092005-06-18 22:59:08 -0700357static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358{
359 return NULL;
360}
361
Eric Dumazet20fea082007-11-14 01:44:41 -0800362struct Qdisc_ops noop_qdisc_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 .id = "noop",
364 .priv_size = 0,
365 .enqueue = noop_enqueue,
366 .dequeue = noop_dequeue,
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700367 .peek = noop_dequeue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 .owner = THIS_MODULE,
369};
370
David S. Miller7698b4f2008-07-16 01:42:40 -0700371static struct netdev_queue noop_netdev_queue = {
David S. Miller7698b4f2008-07-16 01:42:40 -0700372 .qdisc = &noop_qdisc,
Jarek Poplawski9f3ffae2008-10-19 23:37:47 -0700373 .qdisc_sleeping = &noop_qdisc,
David S. Miller7698b4f2008-07-16 01:42:40 -0700374};
375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376struct Qdisc noop_qdisc = {
377 .enqueue = noop_enqueue,
378 .dequeue = noop_dequeue,
379 .flags = TCQ_F_BUILTIN,
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900380 .ops = &noop_qdisc_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 .list = LIST_HEAD_INIT(noop_qdisc.list),
David S. Miller83874002008-07-17 00:53:03 -0700382 .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
David S. Miller7698b4f2008-07-16 01:42:40 -0700383 .dev_queue = &noop_netdev_queue,
Eric Dumazet7b5edbc2010-10-15 19:22:34 +0000384 .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385};
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800386EXPORT_SYMBOL(noop_qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
Eric Dumazet20fea082007-11-14 01:44:41 -0800388static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 .id = "noqueue",
390 .priv_size = 0,
391 .enqueue = noop_enqueue,
392 .dequeue = noop_dequeue,
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700393 .peek = noop_dequeue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 .owner = THIS_MODULE,
395};
396
David S. Miller30ee42b2008-07-18 23:00:11 -0700397static struct Qdisc noqueue_qdisc;
398static struct netdev_queue noqueue_netdev_queue = {
399 .qdisc = &noqueue_qdisc,
Jarek Poplawski9f3ffae2008-10-19 23:37:47 -0700400 .qdisc_sleeping = &noqueue_qdisc,
David S. Miller30ee42b2008-07-18 23:00:11 -0700401};
402
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403static struct Qdisc noqueue_qdisc = {
404 .enqueue = NULL,
405 .dequeue = noop_dequeue,
406 .flags = TCQ_F_BUILTIN,
407 .ops = &noqueue_qdisc_ops,
408 .list = LIST_HEAD_INIT(noqueue_qdisc.list),
David S. Miller30ee42b2008-07-18 23:00:11 -0700409 .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
410 .dev_queue = &noqueue_netdev_queue,
Eric Dumazet7b5edbc2010-10-15 19:22:34 +0000411 .busylock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412};
413
414
David S. Millerd3678b42008-07-21 09:56:13 -0700415static const u8 prio2band[TC_PRIO_MAX+1] =
416 { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 };
Thomas Graf321090e2005-06-18 22:58:35 -0700417
David S. Millerd3678b42008-07-21 09:56:13 -0700418/* 3-band FIFO queue: old style, but should be a bit faster than
419 generic prio+fifo combination.
420 */
421
422#define PFIFO_FAST_BANDS 3
423
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000424/*
425 * Private data for a pfifo_fast scheduler containing:
426 * - queues for the three band
427 * - bitmap indicating which of the bands contain skbs
428 */
429struct pfifo_fast_priv {
430 u32 bitmap;
431 struct sk_buff_head q[PFIFO_FAST_BANDS];
432};
433
434/*
435 * Convert a bitmap to the first band number where an skb is queued, where:
436 * bitmap=0 means there are no skbs on any band.
437 * bitmap=1 means there is an skb on band 0.
438 * bitmap=7 means there are skbs on all 3 bands, etc.
439 */
440static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
441
442static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv,
443 int band)
David S. Millerd3678b42008-07-21 09:56:13 -0700444{
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000445 return priv->q + band;
David S. Millerd3678b42008-07-21 09:56:13 -0700446}
447
448static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)
449{
Krishna Kumara453e062009-08-30 22:20:28 -0700450 if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) {
451 int band = prio2band[skb->priority & TC_PRIO_MAX];
452 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
453 struct sk_buff_head *list = band2list(priv, band);
David S. Millerd3678b42008-07-21 09:56:13 -0700454
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000455 priv->bitmap |= (1 << band);
David S. Millerd3678b42008-07-21 09:56:13 -0700456 qdisc->q.qlen++;
Thomas Graf821d24a2005-06-18 22:58:15 -0700457 return __qdisc_enqueue_tail(skb, qdisc, list);
David S. Millerd3678b42008-07-21 09:56:13 -0700458 }
Thomas Graf821d24a2005-06-18 22:58:15 -0700459
460 return qdisc_drop(skb, qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461}
462
David S. Millerd3678b42008-07-21 09:56:13 -0700463static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464{
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000465 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
466 int band = bitmap2band[priv->bitmap];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000468 if (likely(band >= 0)) {
469 struct sk_buff_head *list = band2list(priv, band);
470 struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list);
471
472 qdisc->q.qlen--;
473 if (skb_queue_empty(list))
474 priv->bitmap &= ~(1 << band);
475
476 return skb;
David S. Millerd3678b42008-07-21 09:56:13 -0700477 }
Thomas Graff87a9c32005-06-18 22:58:53 -0700478
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 return NULL;
480}
481
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700482static struct sk_buff *pfifo_fast_peek(struct Qdisc* qdisc)
483{
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000484 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
485 int band = bitmap2band[priv->bitmap];
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700486
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000487 if (band >= 0) {
488 struct sk_buff_head *list = band2list(priv, band);
489
490 return skb_peek(list);
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700491 }
492
493 return NULL;
494}
495
David S. Millerd3678b42008-07-21 09:56:13 -0700496static void pfifo_fast_reset(struct Qdisc* qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497{
David S. Millerd3678b42008-07-21 09:56:13 -0700498 int prio;
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000499 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
David S. Millerd3678b42008-07-21 09:56:13 -0700500
501 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000502 __qdisc_reset_queue(qdisc, band2list(priv, prio));
David S. Millerd3678b42008-07-21 09:56:13 -0700503
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000504 priv->bitmap = 0;
Thomas Graf821d24a2005-06-18 22:58:15 -0700505 qdisc->qstats.backlog = 0;
David S. Millerd3678b42008-07-21 09:56:13 -0700506 qdisc->q.qlen = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507}
508
David S. Millerd3678b42008-07-21 09:56:13 -0700509static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
510{
511 struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
512
513 memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1);
514 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
515 return skb->len;
516
517nla_put_failure:
518 return -1;
519}
520
521static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
522{
523 int prio;
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000524 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
David S. Millerd3678b42008-07-21 09:56:13 -0700525
526 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000527 skb_queue_head_init(band2list(priv, prio));
David S. Millerd3678b42008-07-21 09:56:13 -0700528
529 return 0;
530}
531
David S. Miller6ec1c692009-09-06 01:58:51 -0700532struct Qdisc_ops pfifo_fast_ops __read_mostly = {
David S. Millerd3678b42008-07-21 09:56:13 -0700533 .id = "pfifo_fast",
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000534 .priv_size = sizeof(struct pfifo_fast_priv),
David S. Millerd3678b42008-07-21 09:56:13 -0700535 .enqueue = pfifo_fast_enqueue,
536 .dequeue = pfifo_fast_dequeue,
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700537 .peek = pfifo_fast_peek,
David S. Millerd3678b42008-07-21 09:56:13 -0700538 .init = pfifo_fast_init,
539 .reset = pfifo_fast_reset,
540 .dump = pfifo_fast_dump,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 .owner = THIS_MODULE,
542};
543
David S. Miller5ce2d482008-07-08 17:06:30 -0700544struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
David S. Millerbb949fb2008-07-08 16:55:56 -0700545 struct Qdisc_ops *ops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546{
547 void *p;
548 struct Qdisc *sch;
Thomas Graf3d54b822005-07-05 14:15:09 -0700549 unsigned int size;
550 int err = -ENOBUFS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
Eric Dumazet5d944c62010-03-31 07:06:04 +0000552 /* ensure that the Qdisc and the private data are 64-byte aligned */
Thomas Graf3d54b822005-07-05 14:15:09 -0700553 size = QDISC_ALIGN(sizeof(*sch));
554 size += ops->priv_size + (QDISC_ALIGNTO - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555
Eric Dumazetf2cd2d32010-11-29 08:14:37 +0000556 p = kzalloc_node(size, GFP_KERNEL,
557 netdev_queue_numa_node_read(dev_queue));
558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (!p)
Thomas Graf3d54b822005-07-05 14:15:09 -0700560 goto errout;
Thomas Graf3d54b822005-07-05 14:15:09 -0700561 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
562 sch->padded = (char *) sch - (char *) p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
564 INIT_LIST_HEAD(&sch->list);
565 skb_queue_head_init(&sch->q);
Eric Dumazet79640a42010-06-02 05:09:29 -0700566 spin_lock_init(&sch->busylock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 sch->ops = ops;
568 sch->enqueue = ops->enqueue;
569 sch->dequeue = ops->dequeue;
David S. Millerbb949fb2008-07-08 16:55:56 -0700570 sch->dev_queue = dev_queue;
David S. Miller5ce2d482008-07-08 17:06:30 -0700571 dev_hold(qdisc_dev(sch));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 atomic_set(&sch->refcnt, 1);
Thomas Graf3d54b822005-07-05 14:15:09 -0700573
574 return sch;
575errout:
WANG Cong01e123d2008-06-27 19:51:35 -0700576 return ERR_PTR(err);
Thomas Graf3d54b822005-07-05 14:15:09 -0700577}
578
Changli Gao3511c912010-10-16 13:04:08 +0000579struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
580 struct Qdisc_ops *ops, unsigned int parentid)
Thomas Graf3d54b822005-07-05 14:15:09 -0700581{
582 struct Qdisc *sch;
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900583
David S. Miller5ce2d482008-07-08 17:06:30 -0700584 sch = qdisc_alloc(dev_queue, ops);
Thomas Graf3d54b822005-07-05 14:15:09 -0700585 if (IS_ERR(sch))
586 goto errout;
Patrick McHardy9f9afec2006-11-29 17:35:18 -0800587 sch->parent = parentid;
Thomas Graf3d54b822005-07-05 14:15:09 -0700588
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 if (!ops->init || ops->init(sch, NULL) == 0)
590 return sch;
591
Thomas Graf0fbbeb12005-08-23 10:12:44 -0700592 qdisc_destroy(sch);
Thomas Graf3d54b822005-07-05 14:15:09 -0700593errout:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 return NULL;
595}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800596EXPORT_SYMBOL(qdisc_create_dflt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
David S. Miller5fb66222008-08-02 20:02:43 -0700598/* Under qdisc_lock(qdisc) and BH! */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599
600void qdisc_reset(struct Qdisc *qdisc)
601{
Eric Dumazet20fea082007-11-14 01:44:41 -0800602 const struct Qdisc_ops *ops = qdisc->ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603
604 if (ops->reset)
605 ops->reset(qdisc);
Jarek Poplawski67305eb2008-11-03 02:52:50 -0800606
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000607 if (qdisc->gso_skb) {
608 kfree_skb(qdisc->gso_skb);
609 qdisc->gso_skb = NULL;
610 qdisc->q.qlen = 0;
611 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800613EXPORT_SYMBOL(qdisc_reset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614
Eric Dumazet5d944c62010-03-31 07:06:04 +0000615static void qdisc_rcu_free(struct rcu_head *head)
616{
617 struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head);
618
619 kfree((char *) qdisc - qdisc->padded);
620}
621
David S. Miller1e0d5a52008-08-17 22:31:26 -0700622void qdisc_destroy(struct Qdisc *qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623{
Eric Dumazet20fea082007-11-14 01:44:41 -0800624 const struct Qdisc_ops *ops = qdisc->ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
David S. Miller1e0d5a52008-08-17 22:31:26 -0700626 if (qdisc->flags & TCQ_F_BUILTIN ||
627 !atomic_dec_and_test(&qdisc->refcnt))
628 return;
629
David S. Miller3a682fb2008-07-20 18:13:01 -0700630#ifdef CONFIG_NET_SCHED
Jarek Poplawskif6e0b232008-08-22 03:24:05 -0700631 qdisc_list_del(qdisc);
632
Jussi Kivilinna175f9c12008-07-20 00:08:47 -0700633 qdisc_put_stab(qdisc->stab);
David S. Miller3a682fb2008-07-20 18:13:01 -0700634#endif
Patrick McHardy85670cc2006-09-27 16:45:45 -0700635 gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
Patrick McHardy85670cc2006-09-27 16:45:45 -0700636 if (ops->reset)
637 ops->reset(qdisc);
638 if (ops->destroy)
639 ops->destroy(qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640
Patrick McHardy85670cc2006-09-27 16:45:45 -0700641 module_put(ops->owner);
David S. Miller5ce2d482008-07-08 17:06:30 -0700642 dev_put(qdisc_dev(qdisc));
David S. Miller8a34c5d2008-07-17 00:47:45 -0700643
Jarek Poplawski554794d2008-10-06 09:54:39 -0700644 kfree_skb(qdisc->gso_skb);
Eric Dumazet5d944c62010-03-31 07:06:04 +0000645 /*
646 * gen_estimator est_timer() might access qdisc->q.lock,
647 * wait a RCU grace period before freeing qdisc.
648 */
649 call_rcu(&qdisc->rcu_head, qdisc_rcu_free);
David S. Miller8a34c5d2008-07-17 00:47:45 -0700650}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800651EXPORT_SYMBOL(qdisc_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
Patrick McHardy589983c2009-09-04 06:41:20 +0000653/* Attach toplevel qdisc to device queue. */
654struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
655 struct Qdisc *qdisc)
656{
657 struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
658 spinlock_t *root_lock;
659
660 root_lock = qdisc_lock(oqdisc);
661 spin_lock_bh(root_lock);
662
663 /* Prune old scheduler */
664 if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
665 qdisc_reset(oqdisc);
666
667 /* ... and graft new one */
668 if (qdisc == NULL)
669 qdisc = &noop_qdisc;
670 dev_queue->qdisc_sleeping = qdisc;
671 rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
672
673 spin_unlock_bh(root_lock);
674
675 return oqdisc;
676}
677
David S. Millere8a04642008-07-17 00:34:19 -0700678static void attach_one_default_qdisc(struct net_device *dev,
679 struct netdev_queue *dev_queue,
680 void *_unused)
681{
682 struct Qdisc *qdisc;
683
684 if (dev->tx_queue_len) {
Changli Gao3511c912010-10-16 13:04:08 +0000685 qdisc = qdisc_create_dflt(dev_queue,
David S. Millerd3678b42008-07-21 09:56:13 -0700686 &pfifo_fast_ops, TC_H_ROOT);
David S. Millere8a04642008-07-17 00:34:19 -0700687 if (!qdisc) {
688 printk(KERN_INFO "%s: activation failed\n", dev->name);
689 return;
690 }
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000691
692 /* Can by-pass the queue discipline for default qdisc */
693 qdisc->flags |= TCQ_F_CAN_BYPASS;
David S. Millere8a04642008-07-17 00:34:19 -0700694 } else {
695 qdisc = &noqueue_qdisc;
696 }
697 dev_queue->qdisc_sleeping = qdisc;
698}
699
David S. Miller6ec1c692009-09-06 01:58:51 -0700700static void attach_default_qdiscs(struct net_device *dev)
701{
702 struct netdev_queue *txq;
703 struct Qdisc *qdisc;
704
705 txq = netdev_get_tx_queue(dev, 0);
706
707 if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) {
708 netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
709 dev->qdisc = txq->qdisc_sleeping;
710 atomic_inc(&dev->qdisc->refcnt);
711 } else {
Changli Gao3511c912010-10-16 13:04:08 +0000712 qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
David S. Miller6ec1c692009-09-06 01:58:51 -0700713 if (qdisc) {
714 qdisc->ops->attach(qdisc);
715 dev->qdisc = qdisc;
716 }
717 }
718}
719
David S. Millere8a04642008-07-17 00:34:19 -0700720static void transition_one_qdisc(struct net_device *dev,
721 struct netdev_queue *dev_queue,
722 void *_need_watchdog)
723{
David S. Miller83874002008-07-17 00:53:03 -0700724 struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
David S. Millere8a04642008-07-17 00:34:19 -0700725 int *need_watchdog_p = _need_watchdog;
726
David S. Millera9312ae2008-08-17 21:51:03 -0700727 if (!(new_qdisc->flags & TCQ_F_BUILTIN))
728 clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
729
David S. Miller83874002008-07-17 00:53:03 -0700730 rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
Eric Dumazet9d214932009-05-17 20:55:16 -0700731 if (need_watchdog_p && new_qdisc != &noqueue_qdisc) {
732 dev_queue->trans_start = 0;
David S. Millere8a04642008-07-17 00:34:19 -0700733 *need_watchdog_p = 1;
Eric Dumazet9d214932009-05-17 20:55:16 -0700734 }
David S. Millere8a04642008-07-17 00:34:19 -0700735}
736
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737void dev_activate(struct net_device *dev)
738{
David S. Millere8a04642008-07-17 00:34:19 -0700739 int need_watchdog;
David S. Millerb0e1e642008-07-08 17:42:10 -0700740
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 /* No queueing discipline is attached to device;
David S. Millerd3678b42008-07-21 09:56:13 -0700742 create default one i.e. pfifo_fast for devices,
743 which need queueing and noqueue_qdisc for
744 virtual interfaces
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 */
746
David S. Miller6ec1c692009-09-06 01:58:51 -0700747 if (dev->qdisc == &noop_qdisc)
748 attach_default_qdiscs(dev);
Patrick McHardyaf356af2009-09-04 06:41:18 +0000749
Tommy S. Christensencacaddf2005-05-03 16:18:52 -0700750 if (!netif_carrier_ok(dev))
751 /* Delay activation until next carrier-on event */
752 return;
753
David S. Millere8a04642008-07-17 00:34:19 -0700754 need_watchdog = 0;
755 netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
Eric Dumazet24824a02010-10-02 06:11:55 +0000756 if (dev_ingress_queue(dev))
757 transition_one_qdisc(dev, dev_ingress_queue(dev), NULL);
David S. Millere8a04642008-07-17 00:34:19 -0700758
759 if (need_watchdog) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 dev->trans_start = jiffies;
761 dev_watchdog_up(dev);
762 }
David S. Millerb0e1e642008-07-08 17:42:10 -0700763}
764
David S. Millere8a04642008-07-17 00:34:19 -0700765static void dev_deactivate_queue(struct net_device *dev,
766 struct netdev_queue *dev_queue,
767 void *_qdisc_default)
David S. Millerb0e1e642008-07-08 17:42:10 -0700768{
David S. Millere8a04642008-07-17 00:34:19 -0700769 struct Qdisc *qdisc_default = _qdisc_default;
David S. Miller970565b2008-07-08 23:10:33 -0700770 struct Qdisc *qdisc;
David S. Millerb0e1e642008-07-08 17:42:10 -0700771
David S. Miller970565b2008-07-08 23:10:33 -0700772 qdisc = dev_queue->qdisc;
David S. Millerb0e1e642008-07-08 17:42:10 -0700773 if (qdisc) {
David S. Miller83874002008-07-17 00:53:03 -0700774 spin_lock_bh(qdisc_lock(qdisc));
775
David S. Millera9312ae2008-08-17 21:51:03 -0700776 if (!(qdisc->flags & TCQ_F_BUILTIN))
777 set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
778
Jarek Poplawskif7a54c12008-08-27 02:22:07 -0700779 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
David S. Millerb0e1e642008-07-08 17:42:10 -0700780 qdisc_reset(qdisc);
David S. Millerd3b753d2008-07-15 20:14:35 -0700781
David S. Miller83874002008-07-17 00:53:03 -0700782 spin_unlock_bh(qdisc_lock(qdisc));
David S. Millerb0e1e642008-07-08 17:42:10 -0700783 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784}
785
David S. Miller4335cd22008-08-17 21:58:07 -0700786static bool some_qdisc_is_busy(struct net_device *dev)
David S. Millere8a04642008-07-17 00:34:19 -0700787{
788 unsigned int i;
789
790 for (i = 0; i < dev->num_tx_queues; i++) {
791 struct netdev_queue *dev_queue;
David S. Miller7698b4f2008-07-16 01:42:40 -0700792 spinlock_t *root_lock;
David S. Millere2627c82008-07-16 00:56:32 -0700793 struct Qdisc *q;
David S. Millere8a04642008-07-17 00:34:19 -0700794 int val;
795
796 dev_queue = netdev_get_tx_queue(dev, i);
David S. Millerb9a3b112008-08-13 15:18:38 -0700797 q = dev_queue->qdisc_sleeping;
David S. Miller5fb66222008-08-02 20:02:43 -0700798 root_lock = qdisc_lock(q);
David S. Millere8a04642008-07-17 00:34:19 -0700799
David S. Miller4335cd22008-08-17 21:58:07 -0700800 spin_lock_bh(root_lock);
David S. Millere8a04642008-07-17 00:34:19 -0700801
Eric Dumazetbc135b22010-06-02 03:23:51 -0700802 val = (qdisc_is_running(q) ||
David S. Millerb9a3b112008-08-13 15:18:38 -0700803 test_bit(__QDISC_STATE_SCHED, &q->state));
David S. Millere8a04642008-07-17 00:34:19 -0700804
David S. Miller4335cd22008-08-17 21:58:07 -0700805 spin_unlock_bh(root_lock);
David S. Millere8a04642008-07-17 00:34:19 -0700806
807 if (val)
808 return true;
809 }
810 return false;
811}
812
Octavian Purdila44345722010-12-13 12:44:07 +0000813void dev_deactivate_many(struct list_head *head)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814{
Octavian Purdila44345722010-12-13 12:44:07 +0000815 struct net_device *dev;
Herbert Xu41a23b02007-05-10 14:12:47 -0700816
Octavian Purdila44345722010-12-13 12:44:07 +0000817 list_for_each_entry(dev, head, unreg_list) {
818 netdev_for_each_tx_queue(dev, dev_deactivate_queue,
819 &noop_qdisc);
820 if (dev_ingress_queue(dev))
821 dev_deactivate_queue(dev, dev_ingress_queue(dev),
822 &noop_qdisc);
823
824 dev_watchdog_down(dev);
825 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826
Herbert Xuce0e32e2007-10-18 22:37:58 -0700827 /* Wait for outstanding qdisc-less dev_queue_xmit calls. */
Herbert Xud4828d82006-06-22 02:28:18 -0700828 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
Herbert Xud4828d82006-06-22 02:28:18 -0700830 /* Wait for outstanding qdisc_run calls. */
Octavian Purdila44345722010-12-13 12:44:07 +0000831 list_for_each_entry(dev, head, unreg_list)
832 while (some_qdisc_is_busy(dev))
833 yield();
834}
835
836void dev_deactivate(struct net_device *dev)
837{
838 LIST_HEAD(single);
839
840 list_add(&dev->unreg_list, &single);
841 dev_deactivate_many(&single);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842}
843
David S. Millerb0e1e642008-07-08 17:42:10 -0700844static void dev_init_scheduler_queue(struct net_device *dev,
845 struct netdev_queue *dev_queue,
David S. Millere8a04642008-07-17 00:34:19 -0700846 void *_qdisc)
David S. Millerb0e1e642008-07-08 17:42:10 -0700847{
David S. Millere8a04642008-07-17 00:34:19 -0700848 struct Qdisc *qdisc = _qdisc;
849
David S. Millerb0e1e642008-07-08 17:42:10 -0700850 dev_queue->qdisc = qdisc;
851 dev_queue->qdisc_sleeping = qdisc;
David S. Millerb0e1e642008-07-08 17:42:10 -0700852}
853
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854void dev_init_scheduler(struct net_device *dev)
855{
Patrick McHardyaf356af2009-09-04 06:41:18 +0000856 dev->qdisc = &noop_qdisc;
David S. Millere8a04642008-07-17 00:34:19 -0700857 netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
Eric Dumazet24824a02010-10-02 06:11:55 +0000858 if (dev_ingress_queue(dev))
859 dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800861 setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862}
863
David S. Millere8a04642008-07-17 00:34:19 -0700864static void shutdown_scheduler_queue(struct net_device *dev,
865 struct netdev_queue *dev_queue,
866 void *_qdisc_default)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867{
David S. Millerb0e1e642008-07-08 17:42:10 -0700868 struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
David S. Millere8a04642008-07-17 00:34:19 -0700869 struct Qdisc *qdisc_default = _qdisc_default;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
David S. Millerb0e1e642008-07-08 17:42:10 -0700871 if (qdisc) {
Jarek Poplawskif7a54c12008-08-27 02:22:07 -0700872 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
David S. Millerb0e1e642008-07-08 17:42:10 -0700873 dev_queue->qdisc_sleeping = qdisc_default;
874
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 qdisc_destroy(qdisc);
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900876 }
David S. Millerb0e1e642008-07-08 17:42:10 -0700877}
878
879void dev_shutdown(struct net_device *dev)
880{
David S. Millere8a04642008-07-17 00:34:19 -0700881 netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
Eric Dumazet24824a02010-10-02 06:11:55 +0000882 if (dev_ingress_queue(dev))
883 shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
Patrick McHardyaf356af2009-09-04 06:41:18 +0000884 qdisc_destroy(dev->qdisc);
885 dev->qdisc = &noop_qdisc;
886
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700887 WARN_ON(timer_pending(&dev->watchdog_timer));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888}