| /* |
| * 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 <linux/if_vlan.h> |
| #include <net/sch_generic.h> |
| #include <net/pkt_sched.h> |
| #include <net/dst.h> |
| #include <trace/events/qdisc.h> |
| |
| /* Qdisc to use by default */ |
| const struct Qdisc_ops *default_qdisc_ops = &pfifo_fast_ops; |
| EXPORT_SYMBOL(default_qdisc_ops); |
| |
| /* 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) |
| { |
| q->gso_skb = skb; |
| q->qstats.requeues++; |
| qdisc_qstats_backlog_inc(q, skb); |
| q->q.qlen++; /* it's still part of the queue */ |
| __netif_schedule(q); |
| |
| return 0; |
| } |
| |
| static void try_bulk_dequeue_skb(struct Qdisc *q, |
| struct sk_buff *skb, |
| const struct netdev_queue *txq, |
| int *packets) |
| { |
| int bytelimit = qdisc_avail_bulklimit(txq) - skb->len; |
| |
| while (bytelimit > 0) { |
| struct sk_buff *nskb = q->dequeue(q); |
| |
| if (!nskb) |
| break; |
| |
| bytelimit -= nskb->len; /* covers GSO len */ |
| skb->next = nskb; |
| skb = nskb; |
| (*packets)++; /* GSO counts as one pkt */ |
| } |
| skb->next = NULL; |
| } |
| |
| /* This variant of try_bulk_dequeue_skb() makes sure |
| * all skbs in the chain are for the same txq |
| */ |
| static void try_bulk_dequeue_skb_slow(struct Qdisc *q, |
| struct sk_buff *skb, |
| int *packets) |
| { |
| int mapping = skb_get_queue_mapping(skb); |
| struct sk_buff *nskb; |
| int cnt = 0; |
| |
| do { |
| nskb = q->dequeue(q); |
| if (!nskb) |
| break; |
| if (unlikely(skb_get_queue_mapping(nskb) != mapping)) { |
| q->skb_bad_txq = nskb; |
| qdisc_qstats_backlog_inc(q, nskb); |
| q->q.qlen++; |
| break; |
| } |
| skb->next = nskb; |
| skb = nskb; |
| } while (++cnt < 8); |
| (*packets) += cnt; |
| skb->next = NULL; |
| } |
| |
| /* Note that dequeue_skb can possibly return a SKB list (via skb->next). |
| * A requeued skb (via q->gso_skb) can also be a SKB list. |
| */ |
| static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, |
| int *packets) |
| { |
| struct sk_buff *skb = q->gso_skb; |
| const struct netdev_queue *txq = q->dev_queue; |
| |
| *packets = 1; |
| if (unlikely(skb)) { |
| /* skb in gso_skb were already validated */ |
| *validate = false; |
| /* check the reason of requeuing without tx lock first */ |
| txq = skb_get_tx_queue(txq->dev, skb); |
| if (!netif_xmit_frozen_or_stopped(txq)) { |
| q->gso_skb = NULL; |
| qdisc_qstats_backlog_dec(q, skb); |
| q->q.qlen--; |
| } else |
| skb = NULL; |
| goto trace; |
| } |
| *validate = true; |
| skb = q->skb_bad_txq; |
| if (unlikely(skb)) { |
| /* check the reason of requeuing without tx lock first */ |
| txq = skb_get_tx_queue(txq->dev, skb); |
| if (!netif_xmit_frozen_or_stopped(txq)) { |
| q->skb_bad_txq = NULL; |
| qdisc_qstats_backlog_dec(q, skb); |
| q->q.qlen--; |
| goto bulk; |
| } |
| skb = NULL; |
| goto trace; |
| } |
| if (!(q->flags & TCQ_F_ONETXQUEUE) || |
| !netif_xmit_frozen_or_stopped(txq)) |
| skb = q->dequeue(q); |
| if (skb) { |
| bulk: |
| if (qdisc_may_bulk(q)) |
| try_bulk_dequeue_skb(q, skb, txq, packets); |
| else |
| try_bulk_dequeue_skb_slow(q, skb, packets); |
| } |
| trace: |
| trace_qdisc_dequeue(q, txq, *packets, skb); |
| return skb; |
| } |
| |
| /* |
| * Transmit possibly several skbs, and handle the return status as |
| * required. Owning running seqcount 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, bool validate) |
| { |
| int ret = NETDEV_TX_BUSY; |
| |
| /* And release qdisc */ |
| spin_unlock(root_lock); |
| |
| /* Note that we validate skb (GSO, checksum, ...) outside of locks */ |
| if (validate) |
| skb = validate_xmit_skb_list(skb, dev); |
| |
| if (likely(skb)) { |
| HARD_TX_LOCK(dev, txq, smp_processor_id()); |
| if (!netif_xmit_frozen_or_stopped(txq)) |
| skb = dev_hard_start_xmit(skb, dev, txq, &ret); |
| |
| HARD_TX_UNLOCK(dev, txq); |
| } else { |
| spin_lock(root_lock); |
| return qdisc_qlen(q); |
| } |
| spin_lock(root_lock); |
| |
| if (dev_xmit_complete(ret)) { |
| /* Driver sent out skb successfully or skb was consumed */ |
| ret = qdisc_qlen(q); |
| } else { |
| /* Driver returned NETDEV_TX_BUSY - requeue skb */ |
| if (unlikely(ret != NETDEV_TX_BUSY)) |
| net_warn_ratelimited("BUG %s code %d qlen %d\n", |
| dev->name, ret, q->q.qlen); |
| |
| ret = dev_requeue_skb(skb, q); |
| } |
| |
| if (ret && netif_xmit_frozen_or_stopped(txq)) |
| ret = 0; |
| |
| return ret; |
| } |
| |
| /* |
| * NOTE: Called under qdisc_lock(q) with locally disabled BH. |
| * |
| * running seqcount 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, int *packets) |
| { |
| struct netdev_queue *txq; |
| struct net_device *dev; |
| spinlock_t *root_lock; |
| struct sk_buff *skb; |
| bool validate; |
| |
| /* Dequeue packet */ |
| skb = dequeue_skb(q, &validate, packets); |
| if (unlikely(!skb)) |
| return 0; |
| |
| root_lock = qdisc_lock(q); |
| dev = qdisc_dev(q); |
| txq = skb_get_tx_queue(dev, skb); |
| |
| return sch_direct_xmit(skb, q, dev, txq, root_lock, validate); |
| } |
| |
| void __qdisc_run(struct Qdisc *q) |
| { |
| int quota = dev_tx_weight; |
| int packets; |
| |
| while (qdisc_restart(q, &packets)) { |
| /* |
| * Ordered by possible occurrence: Postpone processing if |
| * 1. we've exceeded packet quota |
| * 2. another process needs the CPU; |
| */ |
| quota -= packets; |
| if (quota <= 0 || need_resched()) { |
| __netif_schedule(q); |
| break; |
| } |
| } |
| |
| qdisc_run_end(q); |
| } |
| |
| unsigned long dev_trans_start(struct net_device *dev) |
| { |
| unsigned long val, res; |
| unsigned int i; |
| |
| if (is_vlan_dev(dev)) |
| dev = vlan_dev_real_dev(dev); |
| res = netdev_get_tx_queue(dev, 0)->trans_start; |
| for (i = 1; i < dev->num_tx_queues; i++) { |
| val = netdev_get_tx_queue(dev, i)->trans_start; |
| if (val && time_after(val, res)) |
| res = val; |
| } |
| |
| 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); |
| trans_start = txq->trans_start; |
| if (netif_xmit_stopped(txq) && |
| time_after(jiffies, (trans_start + |
| dev->watchdog_timeo))) { |
| some_queue_timedout = 1; |
| txq->trans_timeout++; |
| break; |
| } |
| } |
| |
| if (some_queue_timedout) { |
| WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n", |
| dev->name, netdev_drivername(dev), 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; |
| atomic_inc(&dev->carrier_changes); |
| 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; |
| atomic_inc(&dev->carrier_changes); |
| linkwatch_fire_event(dev); |
| } |
| } |
| EXPORT_SYMBOL(netif_carrier_off); |
| |
| /* "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, |
| struct sk_buff **to_free) |
| { |
| __qdisc_drop(skb, to_free); |
| 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, |
| .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), |
| .dev_queue = &noop_netdev_queue, |
| .running = SEQCNT_ZERO(noop_qdisc.running), |
| .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock), |
| }; |
| EXPORT_SYMBOL(noop_qdisc); |
| |
| static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt) |
| { |
| /* register_qdisc() assigns a default of noop_enqueue if unset, |
| * but __dev_queue_xmit() treats noqueue only as such |
| * if this is NULL - so clear it here. */ |
| qdisc->enqueue = NULL; |
| return 0; |
| } |
| |
| struct Qdisc_ops noqueue_qdisc_ops __read_mostly = { |
| .id = "noqueue", |
| .priv_size = 0, |
| .init = noqueue_init, |
| .enqueue = noop_enqueue, |
| .dequeue = noop_dequeue, |
| .peek = noop_dequeue, |
| .owner = THIS_MODULE, |
| }; |
| |
| 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 qdisc_skb_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 qdisc_skb_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, |
| struct sk_buff **to_free) |
| { |
| if (qdisc->q.qlen < qdisc_dev(qdisc)->tx_queue_len) { |
| int band = prio2band[skb->priority & TC_PRIO_MAX]; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| struct qdisc_skb_head *list = band2list(priv, band); |
| |
| priv->bitmap |= (1 << band); |
| qdisc->q.qlen++; |
| return __qdisc_enqueue_tail(skb, qdisc, list); |
| } |
| |
| return qdisc_drop(skb, qdisc, to_free); |
| } |
| |
| 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 qdisc_skb_head *qh = band2list(priv, band); |
| struct sk_buff *skb = __qdisc_dequeue_head(qh); |
| |
| if (likely(skb != NULL)) { |
| qdisc_qstats_backlog_dec(qdisc, skb); |
| qdisc_bstats_update(qdisc, skb); |
| } |
| |
| qdisc->q.qlen--; |
| if (qh->qlen == 0) |
| 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 qdisc_skb_head *qh = band2list(priv, band); |
| |
| return qh->head; |
| } |
| |
| 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(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); |
| if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) |
| goto nla_put_failure; |
| 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++) |
| qdisc_skb_head_init(band2list(priv, prio)); |
| |
| /* Can by-pass the queue discipline */ |
| qdisc->flags |= TCQ_F_CAN_BYPASS; |
| 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); |
| |
| static struct lock_class_key qdisc_tx_busylock; |
| static struct lock_class_key qdisc_running_key; |
| |
| struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, |
| const struct Qdisc_ops *ops) |
| { |
| void *p; |
| struct Qdisc *sch; |
| unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size; |
| int err = -ENOBUFS; |
| struct net_device *dev = dev_queue->dev; |
| |
| 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); |
| /* if we got non aligned memory, ask more and do alignment ourself */ |
| if (sch != p) { |
| kfree(p); |
| p = kzalloc_node(size + QDISC_ALIGNTO - 1, 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; |
| } |
| qdisc_skb_head_init(&sch->q); |
| spin_lock_init(&sch->q.lock); |
| |
| spin_lock_init(&sch->busylock); |
| lockdep_set_class(&sch->busylock, |
| dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); |
| |
| seqcount_init(&sch->running); |
| lockdep_set_class(&sch->running, |
| dev->qdisc_running_key ?: &qdisc_running_key); |
| |
| sch->ops = ops; |
| sch->enqueue = ops->enqueue; |
| sch->dequeue = ops->dequeue; |
| sch->dev_queue = dev_queue; |
| dev_hold(dev); |
| refcount_set(&sch->refcnt, 1); |
| |
| return sch; |
| errout: |
| return ERR_PTR(err); |
| } |
| |
| struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, |
| const struct Qdisc_ops *ops, |
| unsigned int parentid) |
| { |
| struct Qdisc *sch; |
| |
| if (!try_module_get(ops->owner)) |
| return NULL; |
| |
| sch = qdisc_alloc(dev_queue, ops); |
| if (IS_ERR(sch)) { |
| module_put(ops->owner); |
| return NULL; |
| } |
| sch->parent = parentid; |
| |
| if (!ops->init || ops->init(sch, NULL) == 0) |
| return sch; |
| |
| qdisc_destroy(sch); |
| 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); |
| |
| kfree_skb(qdisc->skb_bad_txq); |
| qdisc->skb_bad_txq = NULL; |
| |
| if (qdisc->gso_skb) { |
| kfree_skb_list(qdisc->gso_skb); |
| qdisc->gso_skb = NULL; |
| } |
| qdisc->q.qlen = 0; |
| qdisc->qstats.backlog = 0; |
| } |
| EXPORT_SYMBOL(qdisc_reset); |
| |
| static void qdisc_rcu_free(struct rcu_head *head) |
| { |
| struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head); |
| |
| if (qdisc_is_percpu_stats(qdisc)) { |
| free_percpu(qdisc->cpu_bstats); |
| free_percpu(qdisc->cpu_qstats); |
| } |
| |
| kfree((char *) qdisc - qdisc->padded); |
| } |
| |
| void qdisc_destroy(struct Qdisc *qdisc) |
| { |
| const struct Qdisc_ops *ops = qdisc->ops; |
| |
| if (qdisc->flags & TCQ_F_BUILTIN || |
| !refcount_dec_and_test(&qdisc->refcnt)) |
| return; |
| |
| #ifdef CONFIG_NET_SCHED |
| qdisc_hash_del(qdisc); |
| |
| qdisc_put_stab(rtnl_dereference(qdisc->stab)); |
| #endif |
| gen_kill_estimator(&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_list(qdisc->gso_skb); |
| kfree_skb(qdisc->skb_bad_txq); |
| /* |
| * 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); |
| |
| /* ... 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; |
| const struct Qdisc_ops *ops = default_qdisc_ops; |
| |
| if (dev->priv_flags & IFF_NO_QUEUE) |
| ops = &noqueue_qdisc_ops; |
| |
| qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT); |
| if (!qdisc) { |
| netdev_info(dev, "activation failed\n"); |
| return; |
| } |
| if (!netif_is_multiqueue(dev)) |
| qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; |
| 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->priv_flags & IFF_NO_QUEUE) { |
| netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); |
| dev->qdisc = txq->qdisc_sleeping; |
| qdisc_refcount_inc(dev->qdisc); |
| } else { |
| qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT); |
| if (qdisc) { |
| dev->qdisc = qdisc; |
| qdisc->ops->attach(qdisc); |
| } |
| } |
| #ifdef CONFIG_NET_SCHED |
| if (dev->qdisc != &noop_qdisc) |
| qdisc_hash_add(dev->qdisc, false); |
| #endif |
| } |
| |
| 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) { |
| 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 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) { |
| netif_trans_update(dev); |
| 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 = rtnl_dereference(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; |
| } |
| |
| static void dev_qdisc_reset(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *none) |
| { |
| struct Qdisc *qdisc = dev_queue->qdisc_sleeping; |
| |
| if (qdisc) |
| qdisc_reset(qdisc); |
| } |
| |
| /** |
| * dev_deactivate_many - deactivate transmissions on several devices |
| * @head: list of devices to deactivate |
| * |
| * This function returns only when all outstanding transmissions |
| * have completed, unless all devices are in dismantle phase. |
| */ |
| void dev_deactivate_many(struct list_head *head) |
| { |
| struct net_device *dev; |
| |
| list_for_each_entry(dev, head, close_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. |
| * This is avoided if all devices are in dismantle phase : |
| * Caller will call synchronize_net() for us |
| */ |
| synchronize_net(); |
| |
| /* Wait for outstanding qdisc_run calls. */ |
| list_for_each_entry(dev, head, close_list) { |
| while (some_qdisc_is_busy(dev)) |
| yield(); |
| /* The new qdisc is assigned at this point so we can safely |
| * unwind stale skb lists and qdisc statistics |
| */ |
| netdev_for_each_tx_queue(dev, dev_qdisc_reset, NULL); |
| if (dev_ingress_queue(dev)) |
| dev_qdisc_reset(dev, dev_ingress_queue(dev), NULL); |
| } |
| } |
| |
| void dev_deactivate(struct net_device *dev) |
| { |
| LIST_HEAD(single); |
| |
| list_add(&dev->close_list, &single); |
| dev_deactivate_many(&single); |
| list_del(&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; |
| |
| rcu_assign_pointer(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)); |
| } |
| |
| void psched_ratecfg_precompute(struct psched_ratecfg *r, |
| const struct tc_ratespec *conf, |
| u64 rate64) |
| { |
| memset(r, 0, sizeof(*r)); |
| r->overhead = conf->overhead; |
| r->rate_bytes_ps = max_t(u64, conf->rate, rate64); |
| r->linklayer = (conf->linklayer & TC_LINKLAYER_MASK); |
| r->mult = 1; |
| /* |
| * The deal here is to replace a divide by a reciprocal one |
| * in fast path (a reciprocal divide is a multiply and a shift) |
| * |
| * Normal formula would be : |
| * time_in_ns = (NSEC_PER_SEC * len) / rate_bps |
| * |
| * We compute mult/shift to use instead : |
| * time_in_ns = (len * mult) >> shift; |
| * |
| * We try to get the highest possible mult value for accuracy, |
| * but have to make sure no overflows will ever happen. |
| */ |
| if (r->rate_bytes_ps > 0) { |
| u64 factor = NSEC_PER_SEC; |
| |
| for (;;) { |
| r->mult = div64_u64(factor, r->rate_bytes_ps); |
| if (r->mult & (1U << 31) || factor & (1ULL << 63)) |
| break; |
| factor <<= 1; |
| r->shift++; |
| } |
| } |
| } |
| EXPORT_SYMBOL(psched_ratecfg_precompute); |