blob: a63029ef3eddc9e1bc19cbc552f327e6fdafa8aa [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));
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +000063 if (!netif_tx_queue_stopped(txq) &&
64 !netif_tx_queue_frozen(txq)) {
Jarek Poplawski62523522008-10-06 10:41:50 -070065 q->gso_skb = NULL;
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +000066 q->q.qlen--;
67 } else
Jarek Poplawskiebf05982008-09-22 22:16:23 -070068 skb = NULL;
69 } else {
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070070 skb = q->dequeue(q);
Jarek Poplawskiebf05982008-09-22 22:16:23 -070071 }
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070072
73 return skb;
74}
75
Krishna Kumar6c1361a2007-06-24 19:56:09 -070076static inline int handle_dev_cpu_collision(struct sk_buff *skb,
David S. Miller970565b2008-07-08 23:10:33 -070077 struct netdev_queue *dev_queue,
Krishna Kumar6c1361a2007-06-24 19:56:09 -070078 struct Qdisc *q)
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070079{
Krishna Kumar6c1361a2007-06-24 19:56:09 -070080 int ret;
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070081
David S. Millerc773e842008-07-08 23:13:53 -070082 if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) {
Krishna Kumar6c1361a2007-06-24 19:56:09 -070083 /*
84 * Same CPU holding the lock. It may be a transient
85 * configuration error, when hard_start_xmit() recurses. We
86 * detect it by checking xmit owner and drop the packet when
87 * deadloop is detected. Return OK to try the next skb.
88 */
Jamal Hadi Salimc716a812007-06-10 17:31:24 -070089 kfree_skb(skb);
Krishna Kumar6c1361a2007-06-24 19:56:09 -070090 if (net_ratelimit())
91 printk(KERN_WARNING "Dead loop on netdevice %s, "
David S. Millerc773e842008-07-08 23:13:53 -070092 "fix it urgently!\n", dev_queue->dev->name);
Krishna Kumar6c1361a2007-06-24 19:56:09 -070093 ret = qdisc_qlen(q);
94 } else {
95 /*
96 * Another cpu is holding lock, requeue & delay xmits for
97 * some time.
98 */
Changli Gaodee42872010-05-02 05:42:16 +000099 __get_cpu_var(softnet_data).cpu_collision++;
David S. Miller37437bb2008-07-16 02:15:04 -0700100 ret = dev_requeue_skb(skb, q);
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700101 }
102
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700103 return ret;
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700104}
105
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900106/*
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000107 * Transmit one skb, and handle the return status as required. Holding the
108 * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this
109 * function.
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700110 *
111 * Returns to the caller:
112 * 0 - queue is empty or throttled.
113 * >0 - queue is not empty.
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700114 */
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000115int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
116 struct net_device *dev, struct netdev_queue *txq,
117 spinlock_t *root_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
Peter P Waskiewicz Jr5f1a4852007-11-13 20:40:55 -0800119 int ret = NETDEV_TX_BUSY;
David S. Miller7698b4f2008-07-16 01:42:40 -0700120
121 /* And release qdisc */
122 spin_unlock(root_lock);
Herbert Xud90df3a2007-05-10 04:55:14 -0700123
David S. Millerc773e842008-07-08 23:13:53 -0700124 HARD_TX_LOCK(dev, txq, smp_processor_id());
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000125 if (!netif_tx_queue_stopped(txq) && !netif_tx_queue_frozen(txq))
David S. Millerfd2ea0a2008-07-17 01:56:23 -0700126 ret = dev_hard_start_xmit(skb, dev, txq);
Patrick McHardy572a9d72009-11-10 06:14:14 +0000127
David S. Millerc773e842008-07-08 23:13:53 -0700128 HARD_TX_UNLOCK(dev, txq);
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700129
David S. Miller7698b4f2008-07-16 01:42:40 -0700130 spin_lock(root_lock);
Jamal Hadi Salimc716a812007-06-10 17:31:24 -0700131
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000132 if (dev_xmit_complete(ret)) {
133 /* Driver sent out skb successfully or skb was consumed */
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700134 ret = qdisc_qlen(q);
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000135 } else if (ret == NETDEV_TX_LOCKED) {
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700136 /* Driver try lock failed */
David S. Millereb6aafe2008-07-08 23:12:38 -0700137 ret = handle_dev_cpu_collision(skb, txq, q);
Jarek Poplawski9a1654b2009-11-15 07:20:12 +0000138 } else {
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700139 /* Driver returned NETDEV_TX_BUSY - requeue skb */
140 if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit()))
141 printk(KERN_WARNING "BUG %s code %d qlen %d\n",
142 dev->name, ret, q->q.qlen);
143
David S. Miller37437bb2008-07-16 02:15:04 -0700144 ret = dev_requeue_skb(skb, q);
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700145 }
146
David S. Millerc3f26a22008-07-31 16:58:50 -0700147 if (ret && (netif_tx_queue_stopped(txq) ||
148 netif_tx_queue_frozen(txq)))
David S. Miller37437bb2008-07-16 02:15:04 -0700149 ret = 0;
150
Krishna Kumar6c1361a2007-06-24 19:56:09 -0700151 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000154/*
155 * NOTE: Called under qdisc_lock(q) with locally disabled BH.
156 *
157 * __QDISC_STATE_RUNNING guarantees only one CPU can process
158 * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
159 * this queue.
160 *
161 * netif_tx_lock serializes accesses to device driver.
162 *
163 * qdisc_lock(q) and netif_tx_lock are mutually exclusive,
164 * if one is grabbed, another must be free.
165 *
166 * Note, that this procedure can be called by a watchdog timer
167 *
168 * Returns to the caller:
169 * 0 - queue is empty or throttled.
170 * >0 - queue is not empty.
171 *
172 */
173static inline int qdisc_restart(struct Qdisc *q)
174{
175 struct netdev_queue *txq;
176 struct net_device *dev;
177 spinlock_t *root_lock;
178 struct sk_buff *skb;
179
180 /* Dequeue packet */
181 skb = dequeue_skb(q);
182 if (unlikely(!skb))
183 return 0;
Eric Dumazet7fee2262010-05-11 23:19:48 +0000184 WARN_ON_ONCE(skb_dst_is_noref(skb));
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000185 root_lock = qdisc_lock(q);
186 dev = qdisc_dev(q);
187 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
188
189 return sch_direct_xmit(skb, q, dev, txq, root_lock);
190}
191
David S. Miller37437bb2008-07-16 02:15:04 -0700192void __qdisc_run(struct Qdisc *q)
Herbert Xu48d83322006-06-19 23:57:59 -0700193{
Herbert Xu2ba25062008-03-28 16:25:26 -0700194 unsigned long start_time = jiffies;
195
David S. Miller37437bb2008-07-16 02:15:04 -0700196 while (qdisc_restart(q)) {
Herbert Xu2ba25062008-03-28 16:25:26 -0700197 /*
198 * Postpone processing if
199 * 1. another process needs the CPU;
200 * 2. we've been doing it for too long.
201 */
202 if (need_resched() || jiffies != start_time) {
David S. Miller37437bb2008-07-16 02:15:04 -0700203 __netif_schedule(q);
Herbert Xu2ba25062008-03-28 16:25:26 -0700204 break;
205 }
206 }
Herbert Xu48d83322006-06-19 23:57:59 -0700207
David S. Millere2627c82008-07-16 00:56:32 -0700208 clear_bit(__QDISC_STATE_RUNNING, &q->state);
Herbert Xu48d83322006-06-19 23:57:59 -0700209}
210
Eric Dumazet9d214932009-05-17 20:55:16 -0700211unsigned long dev_trans_start(struct net_device *dev)
212{
213 unsigned long val, res = dev->trans_start;
214 unsigned int i;
215
216 for (i = 0; i < dev->num_tx_queues; i++) {
217 val = netdev_get_tx_queue(dev, i)->trans_start;
218 if (val && time_after(val, res))
219 res = val;
220 }
221 dev->trans_start = res;
222 return res;
223}
224EXPORT_SYMBOL(dev_trans_start);
225
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226static void dev_watchdog(unsigned long arg)
227{
228 struct net_device *dev = (struct net_device *)arg;
229
Herbert Xu932ff272006-06-09 12:20:56 -0700230 netif_tx_lock(dev);
David S. Millere8a04642008-07-17 00:34:19 -0700231 if (!qdisc_tx_is_noop(dev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 if (netif_device_present(dev) &&
233 netif_running(dev) &&
234 netif_carrier_ok(dev)) {
Eric Dumazet9d214932009-05-17 20:55:16 -0700235 int some_queue_timedout = 0;
David S. Millere8a04642008-07-17 00:34:19 -0700236 unsigned int i;
Eric Dumazet9d214932009-05-17 20:55:16 -0700237 unsigned long trans_start;
Stephen Hemminger338f7562006-05-16 15:02:12 -0700238
David S. Millere8a04642008-07-17 00:34:19 -0700239 for (i = 0; i < dev->num_tx_queues; i++) {
240 struct netdev_queue *txq;
241
242 txq = netdev_get_tx_queue(dev, i);
Eric Dumazet9d214932009-05-17 20:55:16 -0700243 /*
244 * old device drivers set dev->trans_start
245 */
246 trans_start = txq->trans_start ? : dev->trans_start;
247 if (netif_tx_queue_stopped(txq) &&
248 time_after(jiffies, (trans_start +
249 dev->watchdog_timeo))) {
250 some_queue_timedout = 1;
David S. Millere8a04642008-07-17 00:34:19 -0700251 break;
252 }
253 }
254
Eric Dumazet9d214932009-05-17 20:55:16 -0700255 if (some_queue_timedout) {
Arjan van de Ven6579e572008-07-21 13:31:48 -0700256 char drivername[64];
Eric Dumazet9d214932009-05-17 20:55:16 -0700257 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
258 dev->name, netdev_drivername(dev, drivername, 64), i);
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800259 dev->netdev_ops->ndo_tx_timeout(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 }
David S. Millere8a04642008-07-17 00:34:19 -0700261 if (!mod_timer(&dev->watchdog_timer,
262 round_jiffies(jiffies +
263 dev->watchdog_timeo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 dev_hold(dev);
265 }
266 }
Herbert Xu932ff272006-06-09 12:20:56 -0700267 netif_tx_unlock(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
269 dev_put(dev);
270}
271
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272void __netdev_watchdog_up(struct net_device *dev)
273{
Stephen Hemmingerd3147742008-11-19 21:32:24 -0800274 if (dev->netdev_ops->ndo_tx_timeout) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 if (dev->watchdog_timeo <= 0)
276 dev->watchdog_timeo = 5*HZ;
Venkatesh Pallipadi60468d52007-05-31 21:28:44 -0700277 if (!mod_timer(&dev->watchdog_timer,
278 round_jiffies(jiffies + dev->watchdog_timeo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 dev_hold(dev);
280 }
281}
282
283static void dev_watchdog_up(struct net_device *dev)
284{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 __netdev_watchdog_up(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
287
288static void dev_watchdog_down(struct net_device *dev)
289{
Herbert Xu932ff272006-06-09 12:20:56 -0700290 netif_tx_lock_bh(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 if (del_timer(&dev->watchdog_timer))
Stephen Hemminger15333062006-03-20 22:32:28 -0800292 dev_put(dev);
Herbert Xu932ff272006-06-09 12:20:56 -0700293 netif_tx_unlock_bh(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294}
295
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700296/**
297 * netif_carrier_on - set carrier
298 * @dev: network device
299 *
300 * Device has detected that carrier.
301 */
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700302void netif_carrier_on(struct net_device *dev)
303{
Jeff Garzikbfaae0f2007-10-17 23:26:43 -0700304 if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
David S. Millerb4730012008-11-19 15:33:54 -0800305 if (dev->reg_state == NETREG_UNINITIALIZED)
306 return;
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700307 linkwatch_fire_event(dev);
Jeff Garzikbfaae0f2007-10-17 23:26:43 -0700308 if (netif_running(dev))
309 __netdev_watchdog_up(dev);
310 }
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700311}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800312EXPORT_SYMBOL(netif_carrier_on);
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700313
Stephen Hemmingerbea33482007-10-03 16:41:36 -0700314/**
315 * netif_carrier_off - clear carrier
316 * @dev: network device
317 *
318 * Device has detected loss of carrier.
319 */
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700320void netif_carrier_off(struct net_device *dev)
321{
David S. Millerb4730012008-11-19 15:33:54 -0800322 if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
323 if (dev->reg_state == NETREG_UNINITIALIZED)
324 return;
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700325 linkwatch_fire_event(dev);
David S. Millerb4730012008-11-19 15:33:54 -0800326 }
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700327}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800328EXPORT_SYMBOL(netif_carrier_off);
Denis Vlasenko0a242ef2005-08-11 15:32:53 -0700329
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
331 under all circumstances. It is difficult to invent anything faster or
332 cheaper.
333 */
334
Thomas Graf94df1092005-06-18 22:59:08 -0700335static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
337 kfree_skb(skb);
338 return NET_XMIT_CN;
339}
340
Thomas Graf94df1092005-06-18 22:59:08 -0700341static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342{
343 return NULL;
344}
345
Eric Dumazet20fea082007-11-14 01:44:41 -0800346struct Qdisc_ops noop_qdisc_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 .id = "noop",
348 .priv_size = 0,
349 .enqueue = noop_enqueue,
350 .dequeue = noop_dequeue,
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700351 .peek = noop_dequeue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 .owner = THIS_MODULE,
353};
354
David S. Miller7698b4f2008-07-16 01:42:40 -0700355static struct netdev_queue noop_netdev_queue = {
David S. Miller7698b4f2008-07-16 01:42:40 -0700356 .qdisc = &noop_qdisc,
Jarek Poplawski9f3ffae2008-10-19 23:37:47 -0700357 .qdisc_sleeping = &noop_qdisc,
David S. Miller7698b4f2008-07-16 01:42:40 -0700358};
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360struct Qdisc noop_qdisc = {
361 .enqueue = noop_enqueue,
362 .dequeue = noop_dequeue,
363 .flags = TCQ_F_BUILTIN,
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900364 .ops = &noop_qdisc_ops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 .list = LIST_HEAD_INIT(noop_qdisc.list),
David S. Miller83874002008-07-17 00:53:03 -0700366 .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
David S. Miller7698b4f2008-07-16 01:42:40 -0700367 .dev_queue = &noop_netdev_queue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368};
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800369EXPORT_SYMBOL(noop_qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
Eric Dumazet20fea082007-11-14 01:44:41 -0800371static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 .id = "noqueue",
373 .priv_size = 0,
374 .enqueue = noop_enqueue,
375 .dequeue = noop_dequeue,
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700376 .peek = noop_dequeue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 .owner = THIS_MODULE,
378};
379
David S. Miller30ee42b2008-07-18 23:00:11 -0700380static struct Qdisc noqueue_qdisc;
381static struct netdev_queue noqueue_netdev_queue = {
382 .qdisc = &noqueue_qdisc,
Jarek Poplawski9f3ffae2008-10-19 23:37:47 -0700383 .qdisc_sleeping = &noqueue_qdisc,
David S. Miller30ee42b2008-07-18 23:00:11 -0700384};
385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386static struct Qdisc noqueue_qdisc = {
387 .enqueue = NULL,
388 .dequeue = noop_dequeue,
389 .flags = TCQ_F_BUILTIN,
390 .ops = &noqueue_qdisc_ops,
391 .list = LIST_HEAD_INIT(noqueue_qdisc.list),
David S. Miller30ee42b2008-07-18 23:00:11 -0700392 .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
393 .dev_queue = &noqueue_netdev_queue,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394};
395
396
David S. Millerd3678b42008-07-21 09:56:13 -0700397static const u8 prio2band[TC_PRIO_MAX+1] =
398 { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 };
Thomas Graf321090e2005-06-18 22:58:35 -0700399
David S. Millerd3678b42008-07-21 09:56:13 -0700400/* 3-band FIFO queue: old style, but should be a bit faster than
401 generic prio+fifo combination.
402 */
403
404#define PFIFO_FAST_BANDS 3
405
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000406/*
407 * Private data for a pfifo_fast scheduler containing:
408 * - queues for the three band
409 * - bitmap indicating which of the bands contain skbs
410 */
411struct pfifo_fast_priv {
412 u32 bitmap;
413 struct sk_buff_head q[PFIFO_FAST_BANDS];
414};
415
416/*
417 * Convert a bitmap to the first band number where an skb is queued, where:
418 * bitmap=0 means there are no skbs on any band.
419 * bitmap=1 means there is an skb on band 0.
420 * bitmap=7 means there are skbs on all 3 bands, etc.
421 */
422static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
423
424static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv,
425 int band)
David S. Millerd3678b42008-07-21 09:56:13 -0700426{
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000427 return priv->q + band;
David S. Millerd3678b42008-07-21 09:56:13 -0700428}
429
430static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)
431{
Krishna Kumara453e062009-08-30 22:20:28 -0700432 if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) {
433 int band = prio2band[skb->priority & TC_PRIO_MAX];
434 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
435 struct sk_buff_head *list = band2list(priv, band);
David S. Millerd3678b42008-07-21 09:56:13 -0700436
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000437 priv->bitmap |= (1 << band);
David S. Millerd3678b42008-07-21 09:56:13 -0700438 qdisc->q.qlen++;
Thomas Graf821d24a2005-06-18 22:58:15 -0700439 return __qdisc_enqueue_tail(skb, qdisc, list);
David S. Millerd3678b42008-07-21 09:56:13 -0700440 }
Thomas Graf821d24a2005-06-18 22:58:15 -0700441
442 return qdisc_drop(skb, qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443}
444
David S. Millerd3678b42008-07-21 09:56:13 -0700445static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446{
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000447 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
448 int band = bitmap2band[priv->bitmap];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000450 if (likely(band >= 0)) {
451 struct sk_buff_head *list = band2list(priv, band);
452 struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list);
453
454 qdisc->q.qlen--;
455 if (skb_queue_empty(list))
456 priv->bitmap &= ~(1 << band);
457
458 return skb;
David S. Millerd3678b42008-07-21 09:56:13 -0700459 }
Thomas Graff87a9c32005-06-18 22:58:53 -0700460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 return NULL;
462}
463
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700464static struct sk_buff *pfifo_fast_peek(struct Qdisc* qdisc)
465{
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000466 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
467 int band = bitmap2band[priv->bitmap];
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700468
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000469 if (band >= 0) {
470 struct sk_buff_head *list = band2list(priv, band);
471
472 return skb_peek(list);
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700473 }
474
475 return NULL;
476}
477
David S. Millerd3678b42008-07-21 09:56:13 -0700478static void pfifo_fast_reset(struct Qdisc* qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479{
David S. Millerd3678b42008-07-21 09:56:13 -0700480 int prio;
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000481 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
David S. Millerd3678b42008-07-21 09:56:13 -0700482
483 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000484 __qdisc_reset_queue(qdisc, band2list(priv, prio));
David S. Millerd3678b42008-07-21 09:56:13 -0700485
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000486 priv->bitmap = 0;
Thomas Graf821d24a2005-06-18 22:58:15 -0700487 qdisc->qstats.backlog = 0;
David S. Millerd3678b42008-07-21 09:56:13 -0700488 qdisc->q.qlen = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489}
490
David S. Millerd3678b42008-07-21 09:56:13 -0700491static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
492{
493 struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
494
495 memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1);
496 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
497 return skb->len;
498
499nla_put_failure:
500 return -1;
501}
502
503static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
504{
505 int prio;
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000506 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
David S. Millerd3678b42008-07-21 09:56:13 -0700507
508 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000509 skb_queue_head_init(band2list(priv, prio));
David S. Millerd3678b42008-07-21 09:56:13 -0700510
511 return 0;
512}
513
David S. Miller6ec1c692009-09-06 01:58:51 -0700514struct Qdisc_ops pfifo_fast_ops __read_mostly = {
David S. Millerd3678b42008-07-21 09:56:13 -0700515 .id = "pfifo_fast",
Krishna Kumarfd3ae5e2009-08-18 21:55:59 +0000516 .priv_size = sizeof(struct pfifo_fast_priv),
David S. Millerd3678b42008-07-21 09:56:13 -0700517 .enqueue = pfifo_fast_enqueue,
518 .dequeue = pfifo_fast_dequeue,
Jarek Poplawski99c0db22008-10-31 00:45:27 -0700519 .peek = pfifo_fast_peek,
David S. Millerd3678b42008-07-21 09:56:13 -0700520 .init = pfifo_fast_init,
521 .reset = pfifo_fast_reset,
522 .dump = pfifo_fast_dump,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 .owner = THIS_MODULE,
524};
525
David S. Miller5ce2d482008-07-08 17:06:30 -0700526struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
David S. Millerbb949fb2008-07-08 16:55:56 -0700527 struct Qdisc_ops *ops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528{
529 void *p;
530 struct Qdisc *sch;
Thomas Graf3d54b822005-07-05 14:15:09 -0700531 unsigned int size;
532 int err = -ENOBUFS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Eric Dumazet5d944c62010-03-31 07:06:04 +0000534 /* ensure that the Qdisc and the private data are 64-byte aligned */
Thomas Graf3d54b822005-07-05 14:15:09 -0700535 size = QDISC_ALIGN(sizeof(*sch));
536 size += ops->priv_size + (QDISC_ALIGNTO - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700538 p = kzalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 if (!p)
Thomas Graf3d54b822005-07-05 14:15:09 -0700540 goto errout;
Thomas Graf3d54b822005-07-05 14:15:09 -0700541 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
542 sch->padded = (char *) sch - (char *) p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
544 INIT_LIST_HEAD(&sch->list);
545 skb_queue_head_init(&sch->q);
546 sch->ops = ops;
547 sch->enqueue = ops->enqueue;
548 sch->dequeue = ops->dequeue;
David S. Millerbb949fb2008-07-08 16:55:56 -0700549 sch->dev_queue = dev_queue;
David S. Miller5ce2d482008-07-08 17:06:30 -0700550 dev_hold(qdisc_dev(sch));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 atomic_set(&sch->refcnt, 1);
Thomas Graf3d54b822005-07-05 14:15:09 -0700552
553 return sch;
554errout:
WANG Cong01e123d2008-06-27 19:51:35 -0700555 return ERR_PTR(err);
Thomas Graf3d54b822005-07-05 14:15:09 -0700556}
557
David S. Millerbb949fb2008-07-08 16:55:56 -0700558struct Qdisc * qdisc_create_dflt(struct net_device *dev,
559 struct netdev_queue *dev_queue,
560 struct Qdisc_ops *ops,
Patrick McHardy9f9afec2006-11-29 17:35:18 -0800561 unsigned int parentid)
Thomas Graf3d54b822005-07-05 14:15:09 -0700562{
563 struct Qdisc *sch;
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900564
David S. Miller5ce2d482008-07-08 17:06:30 -0700565 sch = qdisc_alloc(dev_queue, ops);
Thomas Graf3d54b822005-07-05 14:15:09 -0700566 if (IS_ERR(sch))
567 goto errout;
Patrick McHardy9f9afec2006-11-29 17:35:18 -0800568 sch->parent = parentid;
Thomas Graf3d54b822005-07-05 14:15:09 -0700569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 if (!ops->init || ops->init(sch, NULL) == 0)
571 return sch;
572
Thomas Graf0fbbeb12005-08-23 10:12:44 -0700573 qdisc_destroy(sch);
Thomas Graf3d54b822005-07-05 14:15:09 -0700574errout:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 return NULL;
576}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800577EXPORT_SYMBOL(qdisc_create_dflt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
David S. Miller5fb66222008-08-02 20:02:43 -0700579/* Under qdisc_lock(qdisc) and BH! */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581void qdisc_reset(struct Qdisc *qdisc)
582{
Eric Dumazet20fea082007-11-14 01:44:41 -0800583 const struct Qdisc_ops *ops = qdisc->ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
585 if (ops->reset)
586 ops->reset(qdisc);
Jarek Poplawski67305eb2008-11-03 02:52:50 -0800587
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000588 if (qdisc->gso_skb) {
589 kfree_skb(qdisc->gso_skb);
590 qdisc->gso_skb = NULL;
591 qdisc->q.qlen = 0;
592 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800594EXPORT_SYMBOL(qdisc_reset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
Eric Dumazet5d944c62010-03-31 07:06:04 +0000596static void qdisc_rcu_free(struct rcu_head *head)
597{
598 struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head);
599
600 kfree((char *) qdisc - qdisc->padded);
601}
602
David S. Miller1e0d5a52008-08-17 22:31:26 -0700603void qdisc_destroy(struct Qdisc *qdisc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604{
Eric Dumazet20fea082007-11-14 01:44:41 -0800605 const struct Qdisc_ops *ops = qdisc->ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
David S. Miller1e0d5a52008-08-17 22:31:26 -0700607 if (qdisc->flags & TCQ_F_BUILTIN ||
608 !atomic_dec_and_test(&qdisc->refcnt))
609 return;
610
David S. Miller3a682fb2008-07-20 18:13:01 -0700611#ifdef CONFIG_NET_SCHED
Jarek Poplawskif6e0b232008-08-22 03:24:05 -0700612 qdisc_list_del(qdisc);
613
Jussi Kivilinna175f9c12008-07-20 00:08:47 -0700614 qdisc_put_stab(qdisc->stab);
David S. Miller3a682fb2008-07-20 18:13:01 -0700615#endif
Patrick McHardy85670cc2006-09-27 16:45:45 -0700616 gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
Patrick McHardy85670cc2006-09-27 16:45:45 -0700617 if (ops->reset)
618 ops->reset(qdisc);
619 if (ops->destroy)
620 ops->destroy(qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
Patrick McHardy85670cc2006-09-27 16:45:45 -0700622 module_put(ops->owner);
David S. Miller5ce2d482008-07-08 17:06:30 -0700623 dev_put(qdisc_dev(qdisc));
David S. Miller8a34c5d2008-07-17 00:47:45 -0700624
Jarek Poplawski554794d2008-10-06 09:54:39 -0700625 kfree_skb(qdisc->gso_skb);
Eric Dumazet5d944c62010-03-31 07:06:04 +0000626 /*
627 * gen_estimator est_timer() might access qdisc->q.lock,
628 * wait a RCU grace period before freeing qdisc.
629 */
630 call_rcu(&qdisc->rcu_head, qdisc_rcu_free);
David S. Miller8a34c5d2008-07-17 00:47:45 -0700631}
Patrick McHardy62e3ba12008-01-22 22:10:23 -0800632EXPORT_SYMBOL(qdisc_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Patrick McHardy589983c2009-09-04 06:41:20 +0000634/* Attach toplevel qdisc to device queue. */
635struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
636 struct Qdisc *qdisc)
637{
638 struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
639 spinlock_t *root_lock;
640
641 root_lock = qdisc_lock(oqdisc);
642 spin_lock_bh(root_lock);
643
644 /* Prune old scheduler */
645 if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
646 qdisc_reset(oqdisc);
647
648 /* ... and graft new one */
649 if (qdisc == NULL)
650 qdisc = &noop_qdisc;
651 dev_queue->qdisc_sleeping = qdisc;
652 rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
653
654 spin_unlock_bh(root_lock);
655
656 return oqdisc;
657}
658
David S. Millere8a04642008-07-17 00:34:19 -0700659static void attach_one_default_qdisc(struct net_device *dev,
660 struct netdev_queue *dev_queue,
661 void *_unused)
662{
663 struct Qdisc *qdisc;
664
665 if (dev->tx_queue_len) {
666 qdisc = qdisc_create_dflt(dev, dev_queue,
David S. Millerd3678b42008-07-21 09:56:13 -0700667 &pfifo_fast_ops, TC_H_ROOT);
David S. Millere8a04642008-07-17 00:34:19 -0700668 if (!qdisc) {
669 printk(KERN_INFO "%s: activation failed\n", dev->name);
670 return;
671 }
Krishna Kumarbbd8a0d2009-08-06 01:44:21 +0000672
673 /* Can by-pass the queue discipline for default qdisc */
674 qdisc->flags |= TCQ_F_CAN_BYPASS;
David S. Millere8a04642008-07-17 00:34:19 -0700675 } else {
676 qdisc = &noqueue_qdisc;
677 }
678 dev_queue->qdisc_sleeping = qdisc;
679}
680
David S. Miller6ec1c692009-09-06 01:58:51 -0700681static void attach_default_qdiscs(struct net_device *dev)
682{
683 struct netdev_queue *txq;
684 struct Qdisc *qdisc;
685
686 txq = netdev_get_tx_queue(dev, 0);
687
688 if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) {
689 netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
690 dev->qdisc = txq->qdisc_sleeping;
691 atomic_inc(&dev->qdisc->refcnt);
692 } else {
693 qdisc = qdisc_create_dflt(dev, txq, &mq_qdisc_ops, TC_H_ROOT);
694 if (qdisc) {
695 qdisc->ops->attach(qdisc);
696 dev->qdisc = qdisc;
697 }
698 }
699}
700
David S. Millere8a04642008-07-17 00:34:19 -0700701static void transition_one_qdisc(struct net_device *dev,
702 struct netdev_queue *dev_queue,
703 void *_need_watchdog)
704{
David S. Miller83874002008-07-17 00:53:03 -0700705 struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
David S. Millere8a04642008-07-17 00:34:19 -0700706 int *need_watchdog_p = _need_watchdog;
707
David S. Millera9312ae2008-08-17 21:51:03 -0700708 if (!(new_qdisc->flags & TCQ_F_BUILTIN))
709 clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
710
David S. Miller83874002008-07-17 00:53:03 -0700711 rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
Eric Dumazet9d214932009-05-17 20:55:16 -0700712 if (need_watchdog_p && new_qdisc != &noqueue_qdisc) {
713 dev_queue->trans_start = 0;
David S. Millere8a04642008-07-17 00:34:19 -0700714 *need_watchdog_p = 1;
Eric Dumazet9d214932009-05-17 20:55:16 -0700715 }
David S. Millere8a04642008-07-17 00:34:19 -0700716}
717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718void dev_activate(struct net_device *dev)
719{
David S. Millere8a04642008-07-17 00:34:19 -0700720 int need_watchdog;
David S. Millerb0e1e642008-07-08 17:42:10 -0700721
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 /* No queueing discipline is attached to device;
David S. Millerd3678b42008-07-21 09:56:13 -0700723 create default one i.e. pfifo_fast for devices,
724 which need queueing and noqueue_qdisc for
725 virtual interfaces
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 */
727
David S. Miller6ec1c692009-09-06 01:58:51 -0700728 if (dev->qdisc == &noop_qdisc)
729 attach_default_qdiscs(dev);
Patrick McHardyaf356af2009-09-04 06:41:18 +0000730
Tommy S. Christensencacaddf2005-05-03 16:18:52 -0700731 if (!netif_carrier_ok(dev))
732 /* Delay activation until next carrier-on event */
733 return;
734
David S. Millere8a04642008-07-17 00:34:19 -0700735 need_watchdog = 0;
736 netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
David S. Miller8d50b532008-07-30 02:37:46 -0700737 transition_one_qdisc(dev, &dev->rx_queue, NULL);
David S. Millere8a04642008-07-17 00:34:19 -0700738
739 if (need_watchdog) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 dev->trans_start = jiffies;
741 dev_watchdog_up(dev);
742 }
David S. Millerb0e1e642008-07-08 17:42:10 -0700743}
744
David S. Millere8a04642008-07-17 00:34:19 -0700745static void dev_deactivate_queue(struct net_device *dev,
746 struct netdev_queue *dev_queue,
747 void *_qdisc_default)
David S. Millerb0e1e642008-07-08 17:42:10 -0700748{
David S. Millere8a04642008-07-17 00:34:19 -0700749 struct Qdisc *qdisc_default = _qdisc_default;
David S. Miller970565b2008-07-08 23:10:33 -0700750 struct Qdisc *qdisc;
David S. Millerb0e1e642008-07-08 17:42:10 -0700751
David S. Miller970565b2008-07-08 23:10:33 -0700752 qdisc = dev_queue->qdisc;
David S. Millerb0e1e642008-07-08 17:42:10 -0700753 if (qdisc) {
David S. Miller83874002008-07-17 00:53:03 -0700754 spin_lock_bh(qdisc_lock(qdisc));
755
David S. Millera9312ae2008-08-17 21:51:03 -0700756 if (!(qdisc->flags & TCQ_F_BUILTIN))
757 set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
758
Jarek Poplawskif7a54c12008-08-27 02:22:07 -0700759 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
David S. Millerb0e1e642008-07-08 17:42:10 -0700760 qdisc_reset(qdisc);
David S. Millerd3b753d2008-07-15 20:14:35 -0700761
David S. Miller83874002008-07-17 00:53:03 -0700762 spin_unlock_bh(qdisc_lock(qdisc));
David S. Millerb0e1e642008-07-08 17:42:10 -0700763 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764}
765
David S. Miller4335cd22008-08-17 21:58:07 -0700766static bool some_qdisc_is_busy(struct net_device *dev)
David S. Millere8a04642008-07-17 00:34:19 -0700767{
768 unsigned int i;
769
770 for (i = 0; i < dev->num_tx_queues; i++) {
771 struct netdev_queue *dev_queue;
David S. Miller7698b4f2008-07-16 01:42:40 -0700772 spinlock_t *root_lock;
David S. Millere2627c82008-07-16 00:56:32 -0700773 struct Qdisc *q;
David S. Millere8a04642008-07-17 00:34:19 -0700774 int val;
775
776 dev_queue = netdev_get_tx_queue(dev, i);
David S. Millerb9a3b112008-08-13 15:18:38 -0700777 q = dev_queue->qdisc_sleeping;
David S. Miller5fb66222008-08-02 20:02:43 -0700778 root_lock = qdisc_lock(q);
David S. Millere8a04642008-07-17 00:34:19 -0700779
David S. Miller4335cd22008-08-17 21:58:07 -0700780 spin_lock_bh(root_lock);
David S. Millere8a04642008-07-17 00:34:19 -0700781
David S. Millerb9a3b112008-08-13 15:18:38 -0700782 val = (test_bit(__QDISC_STATE_RUNNING, &q->state) ||
783 test_bit(__QDISC_STATE_SCHED, &q->state));
David S. Millere8a04642008-07-17 00:34:19 -0700784
David S. Miller4335cd22008-08-17 21:58:07 -0700785 spin_unlock_bh(root_lock);
David S. Millere8a04642008-07-17 00:34:19 -0700786
787 if (val)
788 return true;
789 }
790 return false;
791}
792
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793void dev_deactivate(struct net_device *dev)
794{
David S. Millere8a04642008-07-17 00:34:19 -0700795 netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc);
David S. Miller8d50b532008-07-30 02:37:46 -0700796 dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc);
Herbert Xu41a23b02007-05-10 14:12:47 -0700797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 dev_watchdog_down(dev);
799
Herbert Xuce0e32e2007-10-18 22:37:58 -0700800 /* Wait for outstanding qdisc-less dev_queue_xmit calls. */
Herbert Xud4828d82006-06-22 02:28:18 -0700801 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802
Herbert Xud4828d82006-06-22 02:28:18 -0700803 /* Wait for outstanding qdisc_run calls. */
David S. Miller4335cd22008-08-17 21:58:07 -0700804 while (some_qdisc_is_busy(dev))
805 yield();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806}
807
David S. Millerb0e1e642008-07-08 17:42:10 -0700808static void dev_init_scheduler_queue(struct net_device *dev,
809 struct netdev_queue *dev_queue,
David S. Millere8a04642008-07-17 00:34:19 -0700810 void *_qdisc)
David S. Millerb0e1e642008-07-08 17:42:10 -0700811{
David S. Millere8a04642008-07-17 00:34:19 -0700812 struct Qdisc *qdisc = _qdisc;
813
David S. Millerb0e1e642008-07-08 17:42:10 -0700814 dev_queue->qdisc = qdisc;
815 dev_queue->qdisc_sleeping = qdisc;
David S. Millerb0e1e642008-07-08 17:42:10 -0700816}
817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818void dev_init_scheduler(struct net_device *dev)
819{
Patrick McHardyaf356af2009-09-04 06:41:18 +0000820 dev->qdisc = &noop_qdisc;
David S. Millere8a04642008-07-17 00:34:19 -0700821 netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
David S. Miller8d50b532008-07-30 02:37:46 -0700822 dev_init_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800824 setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825}
826
David S. Millere8a04642008-07-17 00:34:19 -0700827static void shutdown_scheduler_queue(struct net_device *dev,
828 struct netdev_queue *dev_queue,
829 void *_qdisc_default)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830{
David S. Millerb0e1e642008-07-08 17:42:10 -0700831 struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
David S. Millere8a04642008-07-17 00:34:19 -0700832 struct Qdisc *qdisc_default = _qdisc_default;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833
David S. Millerb0e1e642008-07-08 17:42:10 -0700834 if (qdisc) {
Jarek Poplawskif7a54c12008-08-27 02:22:07 -0700835 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
David S. Millerb0e1e642008-07-08 17:42:10 -0700836 dev_queue->qdisc_sleeping = qdisc_default;
837
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 qdisc_destroy(qdisc);
YOSHIFUJI Hideaki10297b92007-02-09 23:25:16 +0900839 }
David S. Millerb0e1e642008-07-08 17:42:10 -0700840}
841
842void dev_shutdown(struct net_device *dev)
843{
David S. Millere8a04642008-07-17 00:34:19 -0700844 netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
David S. Miller8d50b532008-07-30 02:37:46 -0700845 shutdown_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
Patrick McHardyaf356af2009-09-04 06:41:18 +0000846 qdisc_destroy(dev->qdisc);
847 dev->qdisc = &noop_qdisc;
848
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700849 WARN_ON(timer_pending(&dev->watchdog_timer));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850}