| /* |
| * net/sched/sch_generic.c Generic packet scheduler routines. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * Jamal Hadi Salim, <hadi@cyberus.ca> 990601 |
| * - Ingress support |
| */ |
| |
| #include <linux/bitops.h> |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/string.h> |
| #include <linux/errno.h> |
| #include <linux/netdevice.h> |
| #include <linux/skbuff.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/init.h> |
| #include <linux/rcupdate.h> |
| #include <linux/list.h> |
| #include <linux/slab.h> |
| #include <net/pkt_sched.h> |
| #include <net/dst.h> |
| |
| /* Main transmission queue. */ |
| |
| /* Modifications to data participating in scheduling must be protected with |
| * qdisc_lock(qdisc) spinlock. |
| * |
| * The idea is the following: |
| * - enqueue, dequeue are serialized via qdisc root lock |
| * - ingress filtering is also serialized via qdisc root lock |
| * - updates to tree and tree walking are only done under the rtnl mutex. |
| */ |
| |
| static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) |
| { |
| skb_dst_force(skb); |
| q->gso_skb = skb; |
| q->qstats.requeues++; |
| q->q.qlen++; /* it's still part of the queue */ |
| __netif_schedule(q); |
| |
| return 0; |
| } |
| |
| static inline struct sk_buff *dequeue_skb(struct Qdisc *q) |
| { |
| struct sk_buff *skb = q->gso_skb; |
| |
| if (unlikely(skb)) { |
| struct net_device *dev = qdisc_dev(q); |
| struct netdev_queue *txq; |
| |
| /* check the reason of requeuing without tx lock first */ |
| txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); |
| if (!netif_tx_queue_frozen_or_stopped(txq)) { |
| q->gso_skb = NULL; |
| q->q.qlen--; |
| } else |
| skb = NULL; |
| } else { |
| skb = q->dequeue(q); |
| } |
| |
| return skb; |
| } |
| |
| static inline int handle_dev_cpu_collision(struct sk_buff *skb, |
| struct netdev_queue *dev_queue, |
| struct Qdisc *q) |
| { |
| int ret; |
| |
| if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) { |
| /* |
| * Same CPU holding the lock. It may be a transient |
| * configuration error, when hard_start_xmit() recurses. We |
| * detect it by checking xmit owner and drop the packet when |
| * deadloop is detected. Return OK to try the next skb. |
| */ |
| kfree_skb(skb); |
| if (net_ratelimit()) |
| pr_warning("Dead loop on netdevice %s, fix it urgently!\n", |
| dev_queue->dev->name); |
| ret = qdisc_qlen(q); |
| } else { |
| /* |
| * Another cpu is holding lock, requeue & delay xmits for |
| * some time. |
| */ |
| __this_cpu_inc(softnet_data.cpu_collision); |
| ret = dev_requeue_skb(skb, q); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Transmit one skb, and handle the return status as required. Holding the |
| * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this |
| * function. |
| * |
| * Returns to the caller: |
| * 0 - queue is empty or throttled. |
| * >0 - queue is not empty. |
| */ |
| int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, |
| struct net_device *dev, struct netdev_queue *txq, |
| spinlock_t *root_lock) |
| { |
| int ret = NETDEV_TX_BUSY; |
| |
| /* And release qdisc */ |
| spin_unlock(root_lock); |
| |
| HARD_TX_LOCK(dev, txq, smp_processor_id()); |
| if (!netif_tx_queue_frozen_or_stopped(txq)) |
| ret = dev_hard_start_xmit(skb, dev, txq); |
| |
| HARD_TX_UNLOCK(dev, txq); |
| |
| spin_lock(root_lock); |
| |
| if (dev_xmit_complete(ret)) { |
| /* Driver sent out skb successfully or skb was consumed */ |
| ret = qdisc_qlen(q); |
| } else if (ret == NETDEV_TX_LOCKED) { |
| /* Driver try lock failed */ |
| ret = handle_dev_cpu_collision(skb, txq, q); |
| } else { |
| /* Driver returned NETDEV_TX_BUSY - requeue skb */ |
| if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit())) |
| pr_warning("BUG %s code %d qlen %d\n", |
| dev->name, ret, q->q.qlen); |
| |
| ret = dev_requeue_skb(skb, q); |
| } |
| |
| if (ret && netif_tx_queue_frozen_or_stopped(txq)) |
| ret = 0; |
| |
| return ret; |
| } |
| |
| /* |
| * NOTE: Called under qdisc_lock(q) with locally disabled BH. |
| * |
| * __QDISC_STATE_RUNNING guarantees only one CPU can process |
| * this qdisc at a time. qdisc_lock(q) serializes queue accesses for |
| * this queue. |
| * |
| * netif_tx_lock serializes accesses to device driver. |
| * |
| * qdisc_lock(q) and netif_tx_lock are mutually exclusive, |
| * if one is grabbed, another must be free. |
| * |
| * Note, that this procedure can be called by a watchdog timer |
| * |
| * Returns to the caller: |
| * 0 - queue is empty or throttled. |
| * >0 - queue is not empty. |
| * |
| */ |
| static inline int qdisc_restart(struct Qdisc *q) |
| { |
| struct netdev_queue *txq; |
| struct net_device *dev; |
| spinlock_t *root_lock; |
| struct sk_buff *skb; |
| |
| /* Dequeue packet */ |
| skb = dequeue_skb(q); |
| if (unlikely(!skb)) |
| return 0; |
| WARN_ON_ONCE(skb_dst_is_noref(skb)); |
| root_lock = qdisc_lock(q); |
| dev = qdisc_dev(q); |
| txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); |
| |
| return sch_direct_xmit(skb, q, dev, txq, root_lock); |
| } |
| |
| void __qdisc_run(struct Qdisc *q) |
| { |
| unsigned long start_time = jiffies; |
| |
| while (qdisc_restart(q)) { |
| /* |
| * Postpone processing if |
| * 1. another process needs the CPU; |
| * 2. we've been doing it for too long. |
| */ |
| if (need_resched() || jiffies != start_time) { |
| __netif_schedule(q); |
| break; |
| } |
| } |
| |
| qdisc_run_end(q); |
| } |
| |
| unsigned long dev_trans_start(struct net_device *dev) |
| { |
| unsigned long val, res = dev->trans_start; |
| unsigned int i; |
| |
| for (i = 0; i < dev->num_tx_queues; i++) { |
| val = netdev_get_tx_queue(dev, i)->trans_start; |
| if (val && time_after(val, res)) |
| res = val; |
| } |
| dev->trans_start = res; |
| return res; |
| } |
| EXPORT_SYMBOL(dev_trans_start); |
| |
| static void dev_watchdog(unsigned long arg) |
| { |
| struct net_device *dev = (struct net_device *)arg; |
| |
| netif_tx_lock(dev); |
| if (!qdisc_tx_is_noop(dev)) { |
| if (netif_device_present(dev) && |
| netif_running(dev) && |
| netif_carrier_ok(dev)) { |
| int some_queue_timedout = 0; |
| unsigned int i; |
| unsigned long trans_start; |
| |
| for (i = 0; i < dev->num_tx_queues; i++) { |
| struct netdev_queue *txq; |
| |
| txq = netdev_get_tx_queue(dev, i); |
| /* |
| * old device drivers set dev->trans_start |
| */ |
| trans_start = txq->trans_start ? : dev->trans_start; |
| if (netif_tx_queue_stopped(txq) && |
| time_after(jiffies, (trans_start + |
| dev->watchdog_timeo))) { |
| some_queue_timedout = 1; |
| break; |
| } |
| } |
| |
| if (some_queue_timedout) { |
| char drivername[64]; |
| WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n", |
| dev->name, netdev_drivername(dev, drivername, 64), i); |
| dev->netdev_ops->ndo_tx_timeout(dev); |
| } |
| if (!mod_timer(&dev->watchdog_timer, |
| round_jiffies(jiffies + |
| dev->watchdog_timeo))) |
| dev_hold(dev); |
| } |
| } |
| netif_tx_unlock(dev); |
| |
| dev_put(dev); |
| } |
| |
| void __netdev_watchdog_up(struct net_device *dev) |
| { |
| if (dev->netdev_ops->ndo_tx_timeout) { |
| if (dev->watchdog_timeo <= 0) |
| dev->watchdog_timeo = 5*HZ; |
| if (!mod_timer(&dev->watchdog_timer, |
| round_jiffies(jiffies + dev->watchdog_timeo))) |
| dev_hold(dev); |
| } |
| } |
| |
| static void dev_watchdog_up(struct net_device *dev) |
| { |
| __netdev_watchdog_up(dev); |
| } |
| |
| static void dev_watchdog_down(struct net_device *dev) |
| { |
| netif_tx_lock_bh(dev); |
| if (del_timer(&dev->watchdog_timer)) |
| dev_put(dev); |
| netif_tx_unlock_bh(dev); |
| } |
| |
| /** |
| * netif_carrier_on - set carrier |
| * @dev: network device |
| * |
| * Device has detected that carrier. |
| */ |
| void netif_carrier_on(struct net_device *dev) |
| { |
| if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) { |
| if (dev->reg_state == NETREG_UNINITIALIZED) |
| return; |
| linkwatch_fire_event(dev); |
| if (netif_running(dev)) |
| __netdev_watchdog_up(dev); |
| } |
| } |
| EXPORT_SYMBOL(netif_carrier_on); |
| |
| /** |
| * netif_carrier_off - clear carrier |
| * @dev: network device |
| * |
| * Device has detected loss of carrier. |
| */ |
| void netif_carrier_off(struct net_device *dev) |
| { |
| if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) { |
| if (dev->reg_state == NETREG_UNINITIALIZED) |
| return; |
| linkwatch_fire_event(dev); |
| } |
| } |
| EXPORT_SYMBOL(netif_carrier_off); |
| |
| /** |
| * netif_notify_peers - notify network peers about existence of @dev |
| * @dev: network device |
| * |
| * Generate traffic such that interested network peers are aware of |
| * @dev, such as by generating a gratuitous ARP. This may be used when |
| * a device wants to inform the rest of the network about some sort of |
| * reconfiguration such as a failover event or virtual machine |
| * migration. |
| */ |
| void netif_notify_peers(struct net_device *dev) |
| { |
| rtnl_lock(); |
| call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); |
| rtnl_unlock(); |
| } |
| EXPORT_SYMBOL(netif_notify_peers); |
| |
| /* "NOOP" scheduler: the best scheduler, recommended for all interfaces |
| under all circumstances. It is difficult to invent anything faster or |
| cheaper. |
| */ |
| |
| static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc) |
| { |
| kfree_skb(skb); |
| return NET_XMIT_CN; |
| } |
| |
| static struct sk_buff *noop_dequeue(struct Qdisc * qdisc) |
| { |
| return NULL; |
| } |
| |
| struct Qdisc_ops noop_qdisc_ops __read_mostly = { |
| .id = "noop", |
| .priv_size = 0, |
| .enqueue = noop_enqueue, |
| .dequeue = noop_dequeue, |
| .peek = noop_dequeue, |
| .owner = THIS_MODULE, |
| }; |
| |
| static struct netdev_queue noop_netdev_queue = { |
| .qdisc = &noop_qdisc, |
| .qdisc_sleeping = &noop_qdisc, |
| }; |
| |
| struct Qdisc noop_qdisc = { |
| .enqueue = noop_enqueue, |
| .dequeue = noop_dequeue, |
| .flags = TCQ_F_BUILTIN, |
| .ops = &noop_qdisc_ops, |
| .list = LIST_HEAD_INIT(noop_qdisc.list), |
| .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), |
| .dev_queue = &noop_netdev_queue, |
| .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock), |
| }; |
| EXPORT_SYMBOL(noop_qdisc); |
| |
| static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = { |
| .id = "noqueue", |
| .priv_size = 0, |
| .enqueue = noop_enqueue, |
| .dequeue = noop_dequeue, |
| .peek = noop_dequeue, |
| .owner = THIS_MODULE, |
| }; |
| |
| static struct Qdisc noqueue_qdisc; |
| static struct netdev_queue noqueue_netdev_queue = { |
| .qdisc = &noqueue_qdisc, |
| .qdisc_sleeping = &noqueue_qdisc, |
| }; |
| |
| static struct Qdisc noqueue_qdisc = { |
| .enqueue = NULL, |
| .dequeue = noop_dequeue, |
| .flags = TCQ_F_BUILTIN, |
| .ops = &noqueue_qdisc_ops, |
| .list = LIST_HEAD_INIT(noqueue_qdisc.list), |
| .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock), |
| .dev_queue = &noqueue_netdev_queue, |
| .busylock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock), |
| }; |
| |
| |
| static const u8 prio2band[TC_PRIO_MAX + 1] = { |
| 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 |
| }; |
| |
| /* 3-band FIFO queue: old style, but should be a bit faster than |
| generic prio+fifo combination. |
| */ |
| |
| #define PFIFO_FAST_BANDS 3 |
| |
| /* |
| * Private data for a pfifo_fast scheduler containing: |
| * - queues for the three band |
| * - bitmap indicating which of the bands contain skbs |
| */ |
| struct pfifo_fast_priv { |
| u32 bitmap; |
| struct sk_buff_head q[PFIFO_FAST_BANDS]; |
| }; |
| |
| /* |
| * Convert a bitmap to the first band number where an skb is queued, where: |
| * bitmap=0 means there are no skbs on any band. |
| * bitmap=1 means there is an skb on band 0. |
| * bitmap=7 means there are skbs on all 3 bands, etc. |
| */ |
| static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0}; |
| |
| static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv, |
| int band) |
| { |
| return priv->q + band; |
| } |
| |
| static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc) |
| { |
| if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) { |
| int band = prio2band[skb->priority & TC_PRIO_MAX]; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| struct sk_buff_head *list = band2list(priv, band); |
| |
| priv->bitmap |= (1 << band); |
| qdisc->q.qlen++; |
| return __qdisc_enqueue_tail(skb, qdisc, list); |
| } |
| |
| return qdisc_drop(skb, qdisc); |
| } |
| |
| static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc) |
| { |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| int band = bitmap2band[priv->bitmap]; |
| |
| if (likely(band >= 0)) { |
| struct sk_buff_head *list = band2list(priv, band); |
| struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list); |
| |
| qdisc->q.qlen--; |
| if (skb_queue_empty(list)) |
| priv->bitmap &= ~(1 << band); |
| |
| return skb; |
| } |
| |
| return NULL; |
| } |
| |
| static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc) |
| { |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| int band = bitmap2band[priv->bitmap]; |
| |
| if (band >= 0) { |
| struct sk_buff_head *list = band2list(priv, band); |
| |
| return skb_peek(list); |
| } |
| |
| return NULL; |
| } |
| |
| static void pfifo_fast_reset(struct Qdisc *qdisc) |
| { |
| int prio; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| |
| for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
| __qdisc_reset_queue(qdisc, band2list(priv, prio)); |
| |
| priv->bitmap = 0; |
| qdisc->qstats.backlog = 0; |
| qdisc->q.qlen = 0; |
| } |
| |
| static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb) |
| { |
| struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS }; |
| |
| memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1); |
| NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
| return skb->len; |
| |
| nla_put_failure: |
| return -1; |
| } |
| |
| static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt) |
| { |
| int prio; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| |
| for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) |
| skb_queue_head_init(band2list(priv, prio)); |
| |
| return 0; |
| } |
| |
| struct Qdisc_ops pfifo_fast_ops __read_mostly = { |
| .id = "pfifo_fast", |
| .priv_size = sizeof(struct pfifo_fast_priv), |
| .enqueue = pfifo_fast_enqueue, |
| .dequeue = pfifo_fast_dequeue, |
| .peek = pfifo_fast_peek, |
| .init = pfifo_fast_init, |
| .reset = pfifo_fast_reset, |
| .dump = pfifo_fast_dump, |
| .owner = THIS_MODULE, |
| }; |
| EXPORT_SYMBOL(pfifo_fast_ops); |
| |
| struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, |
| struct Qdisc_ops *ops) |
| { |
| void *p; |
| struct Qdisc *sch; |
| unsigned int size; |
| int err = -ENOBUFS; |
| |
| /* ensure that the Qdisc and the private data are 64-byte aligned */ |
| size = QDISC_ALIGN(sizeof(*sch)); |
| size += ops->priv_size + (QDISC_ALIGNTO - 1); |
| |
| p = kzalloc_node(size, GFP_KERNEL, |
| netdev_queue_numa_node_read(dev_queue)); |
| |
| if (!p) |
| goto errout; |
| sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); |
| sch->padded = (char *) sch - (char *) p; |
| |
| INIT_LIST_HEAD(&sch->list); |
| skb_queue_head_init(&sch->q); |
| spin_lock_init(&sch->busylock); |
| sch->ops = ops; |
| sch->enqueue = ops->enqueue; |
| sch->dequeue = ops->dequeue; |
| sch->dev_queue = dev_queue; |
| dev_hold(qdisc_dev(sch)); |
| atomic_set(&sch->refcnt, 1); |
| |
| return sch; |
| errout: |
| return ERR_PTR(err); |
| } |
| |
| struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, |
| struct Qdisc_ops *ops, unsigned int parentid) |
| { |
| struct Qdisc *sch; |
| |
| sch = qdisc_alloc(dev_queue, ops); |
| if (IS_ERR(sch)) |
| goto errout; |
| sch->parent = parentid; |
| |
| if (!ops->init || ops->init(sch, NULL) == 0) |
| return sch; |
| |
| qdisc_destroy(sch); |
| errout: |
| return NULL; |
| } |
| EXPORT_SYMBOL(qdisc_create_dflt); |
| |
| /* Under qdisc_lock(qdisc) and BH! */ |
| |
| void qdisc_reset(struct Qdisc *qdisc) |
| { |
| const struct Qdisc_ops *ops = qdisc->ops; |
| |
| if (ops->reset) |
| ops->reset(qdisc); |
| |
| if (qdisc->gso_skb) { |
| kfree_skb(qdisc->gso_skb); |
| qdisc->gso_skb = NULL; |
| qdisc->q.qlen = 0; |
| } |
| } |
| EXPORT_SYMBOL(qdisc_reset); |
| |
| static void qdisc_rcu_free(struct rcu_head *head) |
| { |
| struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head); |
| |
| kfree((char *) qdisc - qdisc->padded); |
| } |
| |
| void qdisc_destroy(struct Qdisc *qdisc) |
| { |
| const struct Qdisc_ops *ops = qdisc->ops; |
| |
| if (qdisc->flags & TCQ_F_BUILTIN || |
| !atomic_dec_and_test(&qdisc->refcnt)) |
| return; |
| |
| #ifdef CONFIG_NET_SCHED |
| qdisc_list_del(qdisc); |
| |
| qdisc_put_stab(rtnl_dereference(qdisc->stab)); |
| #endif |
| gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); |
| if (ops->reset) |
| ops->reset(qdisc); |
| if (ops->destroy) |
| ops->destroy(qdisc); |
| |
| module_put(ops->owner); |
| dev_put(qdisc_dev(qdisc)); |
| |
| kfree_skb(qdisc->gso_skb); |
| /* |
| * gen_estimator est_timer() might access qdisc->q.lock, |
| * wait a RCU grace period before freeing qdisc. |
| */ |
| call_rcu(&qdisc->rcu_head, qdisc_rcu_free); |
| } |
| EXPORT_SYMBOL(qdisc_destroy); |
| |
| /* Attach toplevel qdisc to device queue. */ |
| struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, |
| struct Qdisc *qdisc) |
| { |
| struct Qdisc *oqdisc = dev_queue->qdisc_sleeping; |
| spinlock_t *root_lock; |
| |
| root_lock = qdisc_lock(oqdisc); |
| spin_lock_bh(root_lock); |
| |
| /* Prune old scheduler */ |
| if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1) |
| qdisc_reset(oqdisc); |
| |
| /* ... and graft new one */ |
| if (qdisc == NULL) |
| qdisc = &noop_qdisc; |
| dev_queue->qdisc_sleeping = qdisc; |
| rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc); |
| |
| spin_unlock_bh(root_lock); |
| |
| return oqdisc; |
| } |
| EXPORT_SYMBOL(dev_graft_qdisc); |
| |
| static void attach_one_default_qdisc(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_unused) |
| { |
| struct Qdisc *qdisc = &noqueue_qdisc; |
| |
| if (dev->tx_queue_len) { |
| qdisc = qdisc_create_dflt(dev_queue, |
| &pfifo_fast_ops, TC_H_ROOT); |
| if (!qdisc) { |
| netdev_info(dev, "activation failed\n"); |
| return; |
| } |
| |
| /* Can by-pass the queue discipline for default qdisc */ |
| qdisc->flags |= TCQ_F_CAN_BYPASS; |
| } |
| dev_queue->qdisc_sleeping = qdisc; |
| } |
| |
| static void attach_default_qdiscs(struct net_device *dev) |
| { |
| struct netdev_queue *txq; |
| struct Qdisc *qdisc; |
| |
| txq = netdev_get_tx_queue(dev, 0); |
| |
| if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) { |
| netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); |
| dev->qdisc = txq->qdisc_sleeping; |
| atomic_inc(&dev->qdisc->refcnt); |
| } else { |
| qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT); |
| if (qdisc) { |
| qdisc->ops->attach(qdisc); |
| dev->qdisc = qdisc; |
| } |
| } |
| } |
| |
| static void transition_one_qdisc(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_need_watchdog) |
| { |
| struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping; |
| int *need_watchdog_p = _need_watchdog; |
| |
| if (!(new_qdisc->flags & TCQ_F_BUILTIN)) |
| clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state); |
| |
| rcu_assign_pointer(dev_queue->qdisc, new_qdisc); |
| if (need_watchdog_p && new_qdisc != &noqueue_qdisc) { |
| dev_queue->trans_start = 0; |
| *need_watchdog_p = 1; |
| } |
| } |
| |
| void dev_activate(struct net_device *dev) |
| { |
| int need_watchdog; |
| |
| /* No queueing discipline is attached to device; |
| create default one i.e. pfifo_fast for devices, |
| which need queueing and noqueue_qdisc for |
| virtual interfaces |
| */ |
| |
| if (dev->qdisc == &noop_qdisc) |
| attach_default_qdiscs(dev); |
| |
| if (!netif_carrier_ok(dev)) |
| /* Delay activation until next carrier-on event */ |
| return; |
| |
| need_watchdog = 0; |
| netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog); |
| if (dev_ingress_queue(dev)) |
| transition_one_qdisc(dev, dev_ingress_queue(dev), NULL); |
| |
| if (need_watchdog) { |
| dev->trans_start = jiffies; |
| dev_watchdog_up(dev); |
| } |
| } |
| EXPORT_SYMBOL(dev_activate); |
| |
| static void dev_deactivate_queue(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_qdisc_default) |
| { |
| struct Qdisc *qdisc_default = _qdisc_default; |
| struct Qdisc *qdisc; |
| |
| qdisc = dev_queue->qdisc; |
| if (qdisc) { |
| spin_lock_bh(qdisc_lock(qdisc)); |
| |
| if (!(qdisc->flags & TCQ_F_BUILTIN)) |
| set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); |
| |
| rcu_assign_pointer(dev_queue->qdisc, qdisc_default); |
| qdisc_reset(qdisc); |
| |
| spin_unlock_bh(qdisc_lock(qdisc)); |
| } |
| } |
| |
| static bool some_qdisc_is_busy(struct net_device *dev) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < dev->num_tx_queues; i++) { |
| struct netdev_queue *dev_queue; |
| spinlock_t *root_lock; |
| struct Qdisc *q; |
| int val; |
| |
| dev_queue = netdev_get_tx_queue(dev, i); |
| q = dev_queue->qdisc_sleeping; |
| root_lock = qdisc_lock(q); |
| |
| spin_lock_bh(root_lock); |
| |
| val = (qdisc_is_running(q) || |
| test_bit(__QDISC_STATE_SCHED, &q->state)); |
| |
| spin_unlock_bh(root_lock); |
| |
| if (val) |
| return true; |
| } |
| return false; |
| } |
| |
| void dev_deactivate_many(struct list_head *head) |
| { |
| struct net_device *dev; |
| |
| list_for_each_entry(dev, head, unreg_list) { |
| netdev_for_each_tx_queue(dev, dev_deactivate_queue, |
| &noop_qdisc); |
| if (dev_ingress_queue(dev)) |
| dev_deactivate_queue(dev, dev_ingress_queue(dev), |
| &noop_qdisc); |
| |
| dev_watchdog_down(dev); |
| } |
| |
| /* Wait for outstanding qdisc-less dev_queue_xmit calls. */ |
| synchronize_rcu(); |
| |
| /* Wait for outstanding qdisc_run calls. */ |
| list_for_each_entry(dev, head, unreg_list) |
| while (some_qdisc_is_busy(dev)) |
| yield(); |
| } |
| |
| void dev_deactivate(struct net_device *dev) |
| { |
| LIST_HEAD(single); |
| |
| list_add(&dev->unreg_list, &single); |
| dev_deactivate_many(&single); |
| } |
| EXPORT_SYMBOL(dev_deactivate); |
| |
| static void dev_init_scheduler_queue(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_qdisc) |
| { |
| struct Qdisc *qdisc = _qdisc; |
| |
| dev_queue->qdisc = qdisc; |
| dev_queue->qdisc_sleeping = qdisc; |
| } |
| |
| void dev_init_scheduler(struct net_device *dev) |
| { |
| dev->qdisc = &noop_qdisc; |
| netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc); |
| if (dev_ingress_queue(dev)) |
| dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc); |
| |
| setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev); |
| } |
| |
| static void shutdown_scheduler_queue(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_qdisc_default) |
| { |
| struct Qdisc *qdisc = dev_queue->qdisc_sleeping; |
| struct Qdisc *qdisc_default = _qdisc_default; |
| |
| if (qdisc) { |
| rcu_assign_pointer(dev_queue->qdisc, qdisc_default); |
| dev_queue->qdisc_sleeping = qdisc_default; |
| |
| qdisc_destroy(qdisc); |
| } |
| } |
| |
| void dev_shutdown(struct net_device *dev) |
| { |
| netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc); |
| if (dev_ingress_queue(dev)) |
| shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc); |
| qdisc_destroy(dev->qdisc); |
| dev->qdisc = &noop_qdisc; |
| |
| WARN_ON(timer_pending(&dev->watchdog_timer)); |
| } |