| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * net/sched/sch_generic.c Generic packet scheduler routines. |
| * |
| * 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 <linux/skb_array.h> |
| #include <linux/if_macvlan.h> |
| #include <net/sch_generic.h> |
| #include <net/pkt_sched.h> |
| #include <net/dst.h> |
| #include <net/hotdata.h> |
| #include <trace/events/qdisc.h> |
| #include <trace/events/net.h> |
| #include <net/xfrm.h> |
| |
| /* Qdisc to use by default */ |
| const struct Qdisc_ops *default_qdisc_ops = &pfifo_fast_ops; |
| EXPORT_SYMBOL(default_qdisc_ops); |
| |
| static void qdisc_maybe_clear_missed(struct Qdisc *q, |
| const struct netdev_queue *txq) |
| { |
| clear_bit(__QDISC_STATE_MISSED, &q->state); |
| |
| /* Make sure the below netif_xmit_frozen_or_stopped() |
| * checking happens after clearing STATE_MISSED. |
| */ |
| smp_mb__after_atomic(); |
| |
| /* Checking netif_xmit_frozen_or_stopped() again to |
| * make sure STATE_MISSED is set if the STATE_MISSED |
| * set by netif_tx_wake_queue()'s rescheduling of |
| * net_tx_action() is cleared by the above clear_bit(). |
| */ |
| if (!netif_xmit_frozen_or_stopped(txq)) |
| set_bit(__QDISC_STATE_MISSED, &q->state); |
| else |
| set_bit(__QDISC_STATE_DRAINING, &q->state); |
| } |
| |
| /* 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. |
| */ |
| |
| #define SKB_XOFF_MAGIC ((struct sk_buff *)1UL) |
| |
| static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q) |
| { |
| const struct netdev_queue *txq = q->dev_queue; |
| spinlock_t *lock = NULL; |
| struct sk_buff *skb; |
| |
| if (q->flags & TCQ_F_NOLOCK) { |
| lock = qdisc_lock(q); |
| spin_lock(lock); |
| } |
| |
| skb = skb_peek(&q->skb_bad_txq); |
| if (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)) { |
| skb = __skb_dequeue(&q->skb_bad_txq); |
| if (qdisc_is_percpu_stats(q)) { |
| qdisc_qstats_cpu_backlog_dec(q, skb); |
| qdisc_qstats_cpu_qlen_dec(q); |
| } else { |
| qdisc_qstats_backlog_dec(q, skb); |
| q->q.qlen--; |
| } |
| } else { |
| skb = SKB_XOFF_MAGIC; |
| qdisc_maybe_clear_missed(q, txq); |
| } |
| } |
| |
| if (lock) |
| spin_unlock(lock); |
| |
| return skb; |
| } |
| |
| static inline struct sk_buff *qdisc_dequeue_skb_bad_txq(struct Qdisc *q) |
| { |
| struct sk_buff *skb = skb_peek(&q->skb_bad_txq); |
| |
| if (unlikely(skb)) |
| skb = __skb_dequeue_bad_txq(q); |
| |
| return skb; |
| } |
| |
| static inline void qdisc_enqueue_skb_bad_txq(struct Qdisc *q, |
| struct sk_buff *skb) |
| { |
| spinlock_t *lock = NULL; |
| |
| if (q->flags & TCQ_F_NOLOCK) { |
| lock = qdisc_lock(q); |
| spin_lock(lock); |
| } |
| |
| __skb_queue_tail(&q->skb_bad_txq, skb); |
| |
| if (qdisc_is_percpu_stats(q)) { |
| qdisc_qstats_cpu_backlog_inc(q, skb); |
| qdisc_qstats_cpu_qlen_inc(q); |
| } else { |
| qdisc_qstats_backlog_inc(q, skb); |
| q->q.qlen++; |
| } |
| |
| if (lock) |
| spin_unlock(lock); |
| } |
| |
| static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) |
| { |
| spinlock_t *lock = NULL; |
| |
| if (q->flags & TCQ_F_NOLOCK) { |
| lock = qdisc_lock(q); |
| spin_lock(lock); |
| } |
| |
| while (skb) { |
| struct sk_buff *next = skb->next; |
| |
| __skb_queue_tail(&q->gso_skb, skb); |
| |
| /* it's still part of the queue */ |
| if (qdisc_is_percpu_stats(q)) { |
| qdisc_qstats_cpu_requeues_inc(q); |
| qdisc_qstats_cpu_backlog_inc(q, skb); |
| qdisc_qstats_cpu_qlen_inc(q); |
| } else { |
| q->qstats.requeues++; |
| qdisc_qstats_backlog_inc(q, skb); |
| q->q.qlen++; |
| } |
| |
| skb = next; |
| } |
| |
| if (lock) { |
| spin_unlock(lock); |
| set_bit(__QDISC_STATE_MISSED, &q->state); |
| } else { |
| __netif_schedule(q); |
| } |
| } |
| |
| 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_mark_not_on_list(skb); |
| } |
| |
| /* 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)) { |
| qdisc_enqueue_skb_bad_txq(q, nskb); |
| break; |
| } |
| skb->next = nskb; |
| skb = nskb; |
| } while (++cnt < 8); |
| (*packets) += cnt; |
| skb_mark_not_on_list(skb); |
| } |
| |
| /* 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) |
| { |
| const struct netdev_queue *txq = q->dev_queue; |
| struct sk_buff *skb = NULL; |
| |
| *packets = 1; |
| if (unlikely(!skb_queue_empty(&q->gso_skb))) { |
| spinlock_t *lock = NULL; |
| |
| if (q->flags & TCQ_F_NOLOCK) { |
| lock = qdisc_lock(q); |
| spin_lock(lock); |
| } |
| |
| skb = skb_peek(&q->gso_skb); |
| |
| /* skb may be null if another cpu pulls gso_skb off in between |
| * empty check and lock. |
| */ |
| if (!skb) { |
| if (lock) |
| spin_unlock(lock); |
| goto validate; |
| } |
| |
| /* skb in gso_skb were already validated */ |
| *validate = false; |
| if (xfrm_offload(skb)) |
| *validate = true; |
| /* check the reason of requeuing without tx lock first */ |
| txq = skb_get_tx_queue(txq->dev, skb); |
| if (!netif_xmit_frozen_or_stopped(txq)) { |
| skb = __skb_dequeue(&q->gso_skb); |
| if (qdisc_is_percpu_stats(q)) { |
| qdisc_qstats_cpu_backlog_dec(q, skb); |
| qdisc_qstats_cpu_qlen_dec(q); |
| } else { |
| qdisc_qstats_backlog_dec(q, skb); |
| q->q.qlen--; |
| } |
| } else { |
| skb = NULL; |
| qdisc_maybe_clear_missed(q, txq); |
| } |
| if (lock) |
| spin_unlock(lock); |
| goto trace; |
| } |
| validate: |
| *validate = true; |
| |
| if ((q->flags & TCQ_F_ONETXQUEUE) && |
| netif_xmit_frozen_or_stopped(txq)) { |
| qdisc_maybe_clear_missed(q, txq); |
| return skb; |
| } |
| |
| skb = qdisc_dequeue_skb_bad_txq(q); |
| if (unlikely(skb)) { |
| if (skb == SKB_XOFF_MAGIC) |
| return NULL; |
| goto bulk; |
| } |
| 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 qdisc running bit guarantees that only one CPU |
| * can execute this function. |
| * |
| * Returns to the caller: |
| * false - hardware queue frozen backoff |
| * true - feel free to send more pkts |
| */ |
| bool 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; |
| bool again = false; |
| |
| /* And release qdisc */ |
| if (root_lock) |
| spin_unlock(root_lock); |
| |
| /* Note that we validate skb (GSO, checksum, ...) outside of locks */ |
| if (validate) |
| skb = validate_xmit_skb_list(skb, dev, &again); |
| |
| #ifdef CONFIG_XFRM_OFFLOAD |
| if (unlikely(again)) { |
| if (root_lock) |
| spin_lock(root_lock); |
| |
| dev_requeue_skb(skb, q); |
| return false; |
| } |
| #endif |
| |
| 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); |
| else |
| qdisc_maybe_clear_missed(q, txq); |
| |
| HARD_TX_UNLOCK(dev, txq); |
| } else { |
| if (root_lock) |
| spin_lock(root_lock); |
| return true; |
| } |
| |
| if (root_lock) |
| spin_lock(root_lock); |
| |
| if (!dev_xmit_complete(ret)) { |
| /* 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); |
| |
| dev_requeue_skb(skb, q); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| /* |
| * 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 bool qdisc_restart(struct Qdisc *q, int *packets) |
| { |
| spinlock_t *root_lock = NULL; |
| struct netdev_queue *txq; |
| struct net_device *dev; |
| struct sk_buff *skb; |
| bool validate; |
| |
| /* Dequeue packet */ |
| skb = dequeue_skb(q, &validate, packets); |
| if (unlikely(!skb)) |
| return false; |
| |
| if (!(q->flags & TCQ_F_NOLOCK)) |
| 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 = READ_ONCE(net_hotdata.dev_tx_weight); |
| int packets; |
| |
| while (qdisc_restart(q, &packets)) { |
| quota -= packets; |
| if (quota <= 0) { |
| if (q->flags & TCQ_F_NOLOCK) |
| set_bit(__QDISC_STATE_MISSED, &q->state); |
| else |
| __netif_schedule(q); |
| |
| break; |
| } |
| } |
| } |
| |
| unsigned long dev_trans_start(struct net_device *dev) |
| { |
| unsigned long res = READ_ONCE(netdev_get_tx_queue(dev, 0)->trans_start); |
| unsigned long val; |
| unsigned int i; |
| |
| for (i = 1; i < dev->num_tx_queues; i++) { |
| val = READ_ONCE(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 netif_freeze_queues(struct net_device *dev) |
| { |
| unsigned int i; |
| int cpu; |
| |
| cpu = smp_processor_id(); |
| for (i = 0; i < dev->num_tx_queues; i++) { |
| struct netdev_queue *txq = netdev_get_tx_queue(dev, i); |
| |
| /* We are the only thread of execution doing a |
| * freeze, but we have to grab the _xmit_lock in |
| * order to synchronize with threads which are in |
| * the ->hard_start_xmit() handler and already |
| * checked the frozen bit. |
| */ |
| __netif_tx_lock(txq, cpu); |
| set_bit(__QUEUE_STATE_FROZEN, &txq->state); |
| __netif_tx_unlock(txq); |
| } |
| } |
| |
| void netif_tx_lock(struct net_device *dev) |
| { |
| spin_lock(&dev->tx_global_lock); |
| netif_freeze_queues(dev); |
| } |
| EXPORT_SYMBOL(netif_tx_lock); |
| |
| static void netif_unfreeze_queues(struct net_device *dev) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < dev->num_tx_queues; i++) { |
| struct netdev_queue *txq = netdev_get_tx_queue(dev, i); |
| |
| /* No need to grab the _xmit_lock here. If the |
| * queue is not stopped for another reason, we |
| * force a schedule. |
| */ |
| clear_bit(__QUEUE_STATE_FROZEN, &txq->state); |
| netif_schedule_queue(txq); |
| } |
| } |
| |
| void netif_tx_unlock(struct net_device *dev) |
| { |
| netif_unfreeze_queues(dev); |
| spin_unlock(&dev->tx_global_lock); |
| } |
| EXPORT_SYMBOL(netif_tx_unlock); |
| |
| static void dev_watchdog(struct timer_list *t) |
| { |
| struct net_device *dev = from_timer(dev, t, watchdog_timer); |
| bool release = true; |
| |
| spin_lock(&dev->tx_global_lock); |
| if (!qdisc_tx_is_noop(dev)) { |
| if (netif_device_present(dev) && |
| netif_running(dev) && |
| netif_carrier_ok(dev)) { |
| unsigned int timedout_ms = 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 = READ_ONCE(txq->trans_start); |
| if (netif_xmit_stopped(txq) && |
| time_after(jiffies, (trans_start + |
| dev->watchdog_timeo))) { |
| timedout_ms = jiffies_to_msecs(jiffies - trans_start); |
| atomic_long_inc(&txq->trans_timeout); |
| break; |
| } |
| } |
| |
| if (unlikely(timedout_ms)) { |
| trace_net_dev_xmit_timeout(dev, i); |
| netdev_crit(dev, "NETDEV WATCHDOG: CPU: %d: transmit queue %u timed out %u ms\n", |
| raw_smp_processor_id(), |
| i, timedout_ms); |
| netif_freeze_queues(dev); |
| dev->netdev_ops->ndo_tx_timeout(dev, i); |
| netif_unfreeze_queues(dev); |
| } |
| if (!mod_timer(&dev->watchdog_timer, |
| round_jiffies(jiffies + |
| dev->watchdog_timeo))) |
| release = false; |
| } |
| } |
| spin_unlock(&dev->tx_global_lock); |
| |
| if (release) |
| netdev_put(dev, &dev->watchdog_dev_tracker); |
| } |
| |
| 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))) |
| netdev_hold(dev, &dev->watchdog_dev_tracker, |
| GFP_ATOMIC); |
| } |
| } |
| EXPORT_SYMBOL_GPL(__netdev_watchdog_up); |
| |
| 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)) |
| netdev_put(dev, &dev->watchdog_dev_tracker); |
| netif_tx_unlock_bh(dev); |
| } |
| |
| /** |
| * netif_carrier_on - set carrier |
| * @dev: network device |
| * |
| * Device has detected acquisition of 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_up_count); |
| 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_down_count); |
| linkwatch_fire_event(dev); |
| } |
| } |
| EXPORT_SYMBOL(netif_carrier_off); |
| |
| /** |
| * netif_carrier_event - report carrier state event |
| * @dev: network device |
| * |
| * Device has detected a carrier event but the carrier state wasn't changed. |
| * Use in drivers when querying carrier state asynchronously, to avoid missing |
| * events (link flaps) if link recovers before it's queried. |
| */ |
| void netif_carrier_event(struct net_device *dev) |
| { |
| if (dev->reg_state == NETREG_UNINITIALIZED) |
| return; |
| atomic_inc(&dev->carrier_up_count); |
| atomic_inc(&dev->carrier_down_count); |
| linkwatch_fire_event(dev); |
| } |
| EXPORT_SYMBOL_GPL(netif_carrier_event); |
| |
| /* "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 = { |
| RCU_POINTER_INITIALIZER(qdisc, &noop_qdisc), |
| RCU_POINTER_INITIALIZER(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, |
| .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock), |
| .gso_skb = { |
| .next = (struct sk_buff *)&noop_qdisc.gso_skb, |
| .prev = (struct sk_buff *)&noop_qdisc.gso_skb, |
| .qlen = 0, |
| .lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.gso_skb.lock), |
| }, |
| .skb_bad_txq = { |
| .next = (struct sk_buff *)&noop_qdisc.skb_bad_txq, |
| .prev = (struct sk_buff *)&noop_qdisc.skb_bad_txq, |
| .qlen = 0, |
| .lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.skb_bad_txq.lock), |
| }, |
| }; |
| EXPORT_SYMBOL(noop_qdisc); |
| |
| static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt, |
| struct netlink_ext_ack *extack) |
| { |
| /* 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, |
| }; |
| |
| const u8 sch_default_prio2band[TC_PRIO_MAX + 1] = { |
| 1, 2, 2, 2, 1, 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1 |
| }; |
| EXPORT_SYMBOL(sch_default_prio2band); |
| |
| /* 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: |
| * - rings for priority bands |
| */ |
| struct pfifo_fast_priv { |
| struct skb_array q[PFIFO_FAST_BANDS]; |
| }; |
| |
| static inline struct skb_array *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) |
| { |
| int band = sch_default_prio2band[skb->priority & TC_PRIO_MAX]; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| struct skb_array *q = band2list(priv, band); |
| unsigned int pkt_len = qdisc_pkt_len(skb); |
| int err; |
| |
| err = skb_array_produce(q, skb); |
| |
| if (unlikely(err)) { |
| if (qdisc_is_percpu_stats(qdisc)) |
| return qdisc_drop_cpu(skb, qdisc, to_free); |
| else |
| return qdisc_drop(skb, qdisc, to_free); |
| } |
| |
| qdisc_update_stats_at_enqueue(qdisc, pkt_len); |
| return NET_XMIT_SUCCESS; |
| } |
| |
| static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc) |
| { |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| struct sk_buff *skb = NULL; |
| bool need_retry = true; |
| int band; |
| |
| retry: |
| for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) { |
| struct skb_array *q = band2list(priv, band); |
| |
| if (__skb_array_empty(q)) |
| continue; |
| |
| skb = __skb_array_consume(q); |
| } |
| if (likely(skb)) { |
| qdisc_update_stats_at_dequeue(qdisc, skb); |
| } else if (need_retry && |
| READ_ONCE(qdisc->state) & QDISC_STATE_NON_EMPTY) { |
| /* Delay clearing the STATE_MISSED here to reduce |
| * the overhead of the second spin_trylock() in |
| * qdisc_run_begin() and __netif_schedule() calling |
| * in qdisc_run_end(). |
| */ |
| clear_bit(__QDISC_STATE_MISSED, &qdisc->state); |
| clear_bit(__QDISC_STATE_DRAINING, &qdisc->state); |
| |
| /* Make sure dequeuing happens after clearing |
| * STATE_MISSED. |
| */ |
| smp_mb__after_atomic(); |
| |
| need_retry = false; |
| |
| goto retry; |
| } |
| |
| return skb; |
| } |
| |
| static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc) |
| { |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| struct sk_buff *skb = NULL; |
| int band; |
| |
| for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) { |
| struct skb_array *q = band2list(priv, band); |
| |
| skb = __skb_array_peek(q); |
| } |
| |
| return skb; |
| } |
| |
| static void pfifo_fast_reset(struct Qdisc *qdisc) |
| { |
| int i, band; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| |
| for (band = 0; band < PFIFO_FAST_BANDS; band++) { |
| struct skb_array *q = band2list(priv, band); |
| struct sk_buff *skb; |
| |
| /* NULL ring is possible if destroy path is due to a failed |
| * skb_array_init() in pfifo_fast_init() case. |
| */ |
| if (!q->ring.queue) |
| continue; |
| |
| while ((skb = __skb_array_consume(q)) != NULL) |
| kfree_skb(skb); |
| } |
| |
| if (qdisc_is_percpu_stats(qdisc)) { |
| for_each_possible_cpu(i) { |
| struct gnet_stats_queue *q; |
| |
| q = per_cpu_ptr(qdisc->cpu_qstats, i); |
| q->backlog = 0; |
| 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, sch_default_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, |
| struct netlink_ext_ack *extack) |
| { |
| unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len; |
| struct pfifo_fast_priv *priv = qdisc_priv(qdisc); |
| int prio; |
| |
| /* guard against zero length rings */ |
| if (!qlen) |
| return -EINVAL; |
| |
| for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
| struct skb_array *q = band2list(priv, prio); |
| int err; |
| |
| err = skb_array_init(q, qlen, GFP_KERNEL); |
| if (err) |
| return -ENOMEM; |
| } |
| |
| /* Can by-pass the queue discipline */ |
| qdisc->flags |= TCQ_F_CAN_BYPASS; |
| return 0; |
| } |
| |
| static void pfifo_fast_destroy(struct Qdisc *sch) |
| { |
| struct pfifo_fast_priv *priv = qdisc_priv(sch); |
| int prio; |
| |
| for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
| struct skb_array *q = band2list(priv, prio); |
| |
| /* NULL ring is possible if destroy path is due to a failed |
| * skb_array_init() in pfifo_fast_init() case. |
| */ |
| if (!q->ring.queue) |
| continue; |
| /* Destroy ring but no need to kfree_skb because a call to |
| * pfifo_fast_reset() has already done that work. |
| */ |
| ptr_ring_cleanup(&q->ring, NULL); |
| } |
| } |
| |
| static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch, |
| unsigned int new_len) |
| { |
| struct pfifo_fast_priv *priv = qdisc_priv(sch); |
| struct skb_array *bands[PFIFO_FAST_BANDS]; |
| int prio; |
| |
| for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) { |
| struct skb_array *q = band2list(priv, prio); |
| |
| bands[prio] = q; |
| } |
| |
| return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len, |
| GFP_KERNEL); |
| } |
| |
| 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, |
| .destroy = pfifo_fast_destroy, |
| .reset = pfifo_fast_reset, |
| .dump = pfifo_fast_dump, |
| .change_tx_queue_len = pfifo_fast_change_tx_queue_len, |
| .owner = THIS_MODULE, |
| .static_flags = TCQ_F_NOLOCK | TCQ_F_CPUSTATS, |
| }; |
| EXPORT_SYMBOL(pfifo_fast_ops); |
| |
| static struct lock_class_key qdisc_tx_busylock; |
| |
| struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, |
| const struct Qdisc_ops *ops, |
| struct netlink_ext_ack *extack) |
| { |
| struct Qdisc *sch; |
| unsigned int size = sizeof(*sch) + ops->priv_size; |
| int err = -ENOBUFS; |
| struct net_device *dev; |
| |
| if (!dev_queue) { |
| NL_SET_ERR_MSG(extack, "No device queue given"); |
| err = -EINVAL; |
| goto errout; |
| } |
| |
| dev = dev_queue->dev; |
| sch = kzalloc_node(size, GFP_KERNEL, netdev_queue_numa_node_read(dev_queue)); |
| |
| if (!sch) |
| goto errout; |
| __skb_queue_head_init(&sch->gso_skb); |
| __skb_queue_head_init(&sch->skb_bad_txq); |
| gnet_stats_basic_sync_init(&sch->bstats); |
| spin_lock_init(&sch->q.lock); |
| |
| if (ops->static_flags & TCQ_F_CPUSTATS) { |
| sch->cpu_bstats = |
| netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync); |
| if (!sch->cpu_bstats) |
| goto errout1; |
| |
| sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue); |
| if (!sch->cpu_qstats) { |
| free_percpu(sch->cpu_bstats); |
| goto errout1; |
| } |
| } |
| |
| spin_lock_init(&sch->busylock); |
| lockdep_set_class(&sch->busylock, |
| dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); |
| |
| /* seqlock has the same scope of busylock, for NOLOCK qdisc */ |
| spin_lock_init(&sch->seqlock); |
| lockdep_set_class(&sch->seqlock, |
| dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); |
| |
| sch->ops = ops; |
| sch->flags = ops->static_flags; |
| sch->enqueue = ops->enqueue; |
| sch->dequeue = ops->dequeue; |
| sch->dev_queue = dev_queue; |
| sch->owner = -1; |
| netdev_hold(dev, &sch->dev_tracker, GFP_KERNEL); |
| refcount_set(&sch->refcnt, 1); |
| |
| return sch; |
| errout1: |
| kfree(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 netlink_ext_ack *extack) |
| { |
| struct Qdisc *sch; |
| |
| if (!try_module_get(ops->owner)) { |
| NL_SET_ERR_MSG(extack, "Failed to increase module reference counter"); |
| return NULL; |
| } |
| |
| sch = qdisc_alloc(dev_queue, ops, extack); |
| if (IS_ERR(sch)) { |
| module_put(ops->owner); |
| return NULL; |
| } |
| sch->parent = parentid; |
| |
| if (!ops->init || ops->init(sch, NULL, extack) == 0) { |
| trace_qdisc_create(ops, dev_queue->dev, parentid); |
| return sch; |
| } |
| |
| qdisc_put(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; |
| |
| trace_qdisc_reset(qdisc); |
| |
| if (ops->reset) |
| ops->reset(qdisc); |
| |
| __skb_queue_purge(&qdisc->gso_skb); |
| __skb_queue_purge(&qdisc->skb_bad_txq); |
| |
| qdisc->q.qlen = 0; |
| qdisc->qstats.backlog = 0; |
| } |
| EXPORT_SYMBOL(qdisc_reset); |
| |
| void qdisc_free(struct Qdisc *qdisc) |
| { |
| if (qdisc_is_percpu_stats(qdisc)) { |
| free_percpu(qdisc->cpu_bstats); |
| free_percpu(qdisc->cpu_qstats); |
| } |
| |
| kfree(qdisc); |
| } |
| |
| static void qdisc_free_cb(struct rcu_head *head) |
| { |
| struct Qdisc *q = container_of(head, struct Qdisc, rcu); |
| |
| qdisc_free(q); |
| } |
| |
| static void __qdisc_destroy(struct Qdisc *qdisc) |
| { |
| const struct Qdisc_ops *ops = qdisc->ops; |
| struct net_device *dev = qdisc_dev(qdisc); |
| |
| #ifdef CONFIG_NET_SCHED |
| qdisc_hash_del(qdisc); |
| |
| qdisc_put_stab(rtnl_dereference(qdisc->stab)); |
| #endif |
| gen_kill_estimator(&qdisc->rate_est); |
| |
| qdisc_reset(qdisc); |
| |
| |
| if (ops->destroy) |
| ops->destroy(qdisc); |
| |
| module_put(ops->owner); |
| netdev_put(dev, &qdisc->dev_tracker); |
| |
| trace_qdisc_destroy(qdisc); |
| |
| call_rcu(&qdisc->rcu, qdisc_free_cb); |
| } |
| |
| void qdisc_destroy(struct Qdisc *qdisc) |
| { |
| if (qdisc->flags & TCQ_F_BUILTIN) |
| return; |
| |
| __qdisc_destroy(qdisc); |
| } |
| |
| void qdisc_put(struct Qdisc *qdisc) |
| { |
| if (!qdisc) |
| return; |
| |
| if (qdisc->flags & TCQ_F_BUILTIN || |
| !refcount_dec_and_test(&qdisc->refcnt)) |
| return; |
| |
| __qdisc_destroy(qdisc); |
| } |
| EXPORT_SYMBOL(qdisc_put); |
| |
| /* Version of qdisc_put() that is called with rtnl mutex unlocked. |
| * Intended to be used as optimization, this function only takes rtnl lock if |
| * qdisc reference counter reached zero. |
| */ |
| |
| void qdisc_put_unlocked(struct Qdisc *qdisc) |
| { |
| if (qdisc->flags & TCQ_F_BUILTIN || |
| !refcount_dec_and_rtnl_lock(&qdisc->refcnt)) |
| return; |
| |
| __qdisc_destroy(qdisc); |
| rtnl_unlock(); |
| } |
| EXPORT_SYMBOL(qdisc_put_unlocked); |
| |
| /* Attach toplevel qdisc to device queue. */ |
| struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, |
| struct Qdisc *qdisc) |
| { |
| struct Qdisc *oqdisc = rtnl_dereference(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; |
| rcu_assign_pointer(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 shutdown_scheduler_queue(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_qdisc_default) |
| { |
| struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); |
| struct Qdisc *qdisc_default = _qdisc_default; |
| |
| if (qdisc) { |
| rcu_assign_pointer(dev_queue->qdisc, qdisc_default); |
| rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc_default); |
| |
| qdisc_put(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; |
| else if(dev->type == ARPHRD_CAN) |
| ops = &pfifo_fast_ops; |
| |
| qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT, NULL); |
| if (!qdisc) |
| return; |
| |
| if (!netif_is_multiqueue(dev)) |
| qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; |
| rcu_assign_pointer(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); |
| qdisc = rtnl_dereference(txq->qdisc_sleeping); |
| rcu_assign_pointer(dev->qdisc, qdisc); |
| qdisc_refcount_inc(qdisc); |
| } else { |
| qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT, NULL); |
| if (qdisc) { |
| rcu_assign_pointer(dev->qdisc, qdisc); |
| qdisc->ops->attach(qdisc); |
| } |
| } |
| qdisc = rtnl_dereference(dev->qdisc); |
| |
| /* Detect default qdisc setup/init failed and fallback to "noqueue" */ |
| if (qdisc == &noop_qdisc) { |
| netdev_warn(dev, "default qdisc (%s) fail, fallback to %s\n", |
| default_qdisc_ops->id, noqueue_qdisc_ops.id); |
| netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc); |
| dev->priv_flags |= IFF_NO_QUEUE; |
| netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); |
| qdisc = rtnl_dereference(txq->qdisc_sleeping); |
| rcu_assign_pointer(dev->qdisc, qdisc); |
| qdisc_refcount_inc(qdisc); |
| dev->priv_flags ^= IFF_NO_QUEUE; |
| } |
| |
| #ifdef CONFIG_NET_SCHED |
| if (qdisc != &noop_qdisc) |
| qdisc_hash_add(qdisc, false); |
| #endif |
| } |
| |
| static void transition_one_qdisc(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_need_watchdog) |
| { |
| struct Qdisc *new_qdisc = rtnl_dereference(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) { |
| WRITE_ONCE(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 (rtnl_dereference(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 qdisc_deactivate(struct Qdisc *qdisc) |
| { |
| if (qdisc->flags & TCQ_F_BUILTIN) |
| return; |
| |
| set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); |
| } |
| |
| 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) { |
| qdisc_deactivate(qdisc); |
| rcu_assign_pointer(dev_queue->qdisc, qdisc_default); |
| } |
| } |
| |
| static void dev_reset_queue(struct net_device *dev, |
| struct netdev_queue *dev_queue, |
| void *_unused) |
| { |
| struct Qdisc *qdisc; |
| bool nolock; |
| |
| qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); |
| if (!qdisc) |
| return; |
| |
| nolock = qdisc->flags & TCQ_F_NOLOCK; |
| |
| if (nolock) |
| spin_lock_bh(&qdisc->seqlock); |
| spin_lock_bh(qdisc_lock(qdisc)); |
| |
| qdisc_reset(qdisc); |
| |
| spin_unlock_bh(qdisc_lock(qdisc)); |
| if (nolock) { |
| clear_bit(__QDISC_STATE_MISSED, &qdisc->state); |
| clear_bit(__QDISC_STATE_DRAINING, &qdisc->state); |
| spin_unlock_bh(&qdisc->seqlock); |
| } |
| } |
| |
| 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 = rtnl_dereference(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; |
| } |
| |
| /** |
| * 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 or |
| * outstanding qdisc enqueuing calls. |
| * This is avoided if all devices are in dismantle phase : |
| * Caller will call synchronize_net() for us |
| */ |
| synchronize_net(); |
| |
| list_for_each_entry(dev, head, close_list) { |
| netdev_for_each_tx_queue(dev, dev_reset_queue, NULL); |
| |
| if (dev_ingress_queue(dev)) |
| dev_reset_queue(dev, dev_ingress_queue(dev), NULL); |
| } |
| |
| /* Wait for outstanding qdisc_run calls. */ |
| list_for_each_entry(dev, head, close_list) { |
| while (some_qdisc_is_busy(dev)) { |
| /* wait_event() would avoid this sleep-loop but would |
| * require expensive checks in the fast paths of packet |
| * processing which isn't worth it. |
| */ |
| schedule_timeout_uninterruptible(1); |
| } |
| } |
| } |
| |
| 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 int qdisc_change_tx_queue_len(struct net_device *dev, |
| struct netdev_queue *dev_queue) |
| { |
| struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); |
| const struct Qdisc_ops *ops = qdisc->ops; |
| |
| if (ops->change_tx_queue_len) |
| return ops->change_tx_queue_len(qdisc, dev->tx_queue_len); |
| return 0; |
| } |
| |
| void dev_qdisc_change_real_num_tx(struct net_device *dev, |
| unsigned int new_real_tx) |
| { |
| struct Qdisc *qdisc = rtnl_dereference(dev->qdisc); |
| |
| if (qdisc->ops->change_real_num_tx) |
| qdisc->ops->change_real_num_tx(qdisc, new_real_tx); |
| } |
| |
| void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx) |
| { |
| #ifdef CONFIG_NET_SCHED |
| struct net_device *dev = qdisc_dev(sch); |
| struct Qdisc *qdisc; |
| unsigned int i; |
| |
| for (i = new_real_tx; i < dev->real_num_tx_queues; i++) { |
| qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc_sleeping); |
| /* Only update the default qdiscs we created, |
| * qdiscs with handles are always hashed. |
| */ |
| if (qdisc != &noop_qdisc && !qdisc->handle) |
| qdisc_hash_del(qdisc); |
| } |
| for (i = dev->real_num_tx_queues; i < new_real_tx; i++) { |
| qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc_sleeping); |
| if (qdisc != &noop_qdisc && !qdisc->handle) |
| qdisc_hash_add(qdisc, false); |
| } |
| #endif |
| } |
| EXPORT_SYMBOL(mq_change_real_num_tx); |
| |
| int dev_qdisc_change_tx_queue_len(struct net_device *dev) |
| { |
| bool up = dev->flags & IFF_UP; |
| unsigned int i; |
| int ret = 0; |
| |
| if (up) |
| dev_deactivate(dev); |
| |
| for (i = 0; i < dev->num_tx_queues; i++) { |
| ret = qdisc_change_tx_queue_len(dev, &dev->_tx[i]); |
| |
| /* TODO: revert changes on a partial failure */ |
| if (ret) |
| break; |
| } |
| |
| if (up) |
| dev_activate(dev); |
| return ret; |
| } |
| |
| 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); |
| rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc); |
| } |
| |
| void dev_init_scheduler(struct net_device *dev) |
| { |
| rcu_assign_pointer(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); |
| |
| timer_setup(&dev->watchdog_timer, dev_watchdog, 0); |
| } |
| |
| 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_put(rtnl_dereference(dev->qdisc)); |
| rcu_assign_pointer(dev->qdisc, &noop_qdisc); |
| |
| WARN_ON(timer_pending(&dev->watchdog_timer)); |
| } |
| |
| /** |
| * psched_ratecfg_precompute__() - Pre-compute values for reciprocal division |
| * @rate: Rate to compute reciprocal division values of |
| * @mult: Multiplier for reciprocal division |
| * @shift: Shift for reciprocal division |
| * |
| * The multiplier and shift for reciprocal division by rate are stored |
| * in mult and shift. |
| * |
| * 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. |
| * |
| * reciprocal_value() is not used here it doesn't handle 64-bit values. |
| */ |
| static void psched_ratecfg_precompute__(u64 rate, u32 *mult, u8 *shift) |
| { |
| u64 factor = NSEC_PER_SEC; |
| |
| *mult = 1; |
| *shift = 0; |
| |
| if (rate <= 0) |
| return; |
| |
| for (;;) { |
| *mult = div64_u64(factor, rate); |
| if (*mult & (1U << 31) || factor & (1ULL << 63)) |
| break; |
| factor <<= 1; |
| (*shift)++; |
| } |
| } |
| |
| 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->mpu = conf->mpu; |
| r->rate_bytes_ps = max_t(u64, conf->rate, rate64); |
| r->linklayer = (conf->linklayer & TC_LINKLAYER_MASK); |
| psched_ratecfg_precompute__(r->rate_bytes_ps, &r->mult, &r->shift); |
| } |
| EXPORT_SYMBOL(psched_ratecfg_precompute); |
| |
| void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64) |
| { |
| r->rate_pkts_ps = pktrate64; |
| psched_ratecfg_precompute__(r->rate_pkts_ps, &r->mult, &r->shift); |
| } |
| EXPORT_SYMBOL(psched_ppscfg_precompute); |
| |
| void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp, |
| struct tcf_proto *tp_head) |
| { |
| /* Protected with chain0->filter_chain_lock. |
| * Can't access chain directly because tp_head can be NULL. |
| */ |
| struct mini_Qdisc *miniq_old = |
| rcu_dereference_protected(*miniqp->p_miniq, 1); |
| struct mini_Qdisc *miniq; |
| |
| if (!tp_head) { |
| RCU_INIT_POINTER(*miniqp->p_miniq, NULL); |
| } else { |
| miniq = miniq_old != &miniqp->miniq1 ? |
| &miniqp->miniq1 : &miniqp->miniq2; |
| |
| /* We need to make sure that readers won't see the miniq |
| * we are about to modify. So ensure that at least one RCU |
| * grace period has elapsed since the miniq was made |
| * inactive. |
| */ |
| if (IS_ENABLED(CONFIG_PREEMPT_RT)) |
| cond_synchronize_rcu(miniq->rcu_state); |
| else if (!poll_state_synchronize_rcu(miniq->rcu_state)) |
| synchronize_rcu_expedited(); |
| |
| miniq->filter_list = tp_head; |
| rcu_assign_pointer(*miniqp->p_miniq, miniq); |
| } |
| |
| if (miniq_old) |
| /* This is counterpart of the rcu sync above. We need to |
| * block potential new user of miniq_old until all readers |
| * are not seeing it. |
| */ |
| miniq_old->rcu_state = start_poll_synchronize_rcu(); |
| } |
| EXPORT_SYMBOL(mini_qdisc_pair_swap); |
| |
| void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp, |
| struct tcf_block *block) |
| { |
| miniqp->miniq1.block = block; |
| miniqp->miniq2.block = block; |
| } |
| EXPORT_SYMBOL(mini_qdisc_pair_block_init); |
| |
| void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc, |
| struct mini_Qdisc __rcu **p_miniq) |
| { |
| miniqp->miniq1.cpu_bstats = qdisc->cpu_bstats; |
| miniqp->miniq1.cpu_qstats = qdisc->cpu_qstats; |
| miniqp->miniq2.cpu_bstats = qdisc->cpu_bstats; |
| miniqp->miniq2.cpu_qstats = qdisc->cpu_qstats; |
| miniqp->miniq1.rcu_state = get_state_synchronize_rcu(); |
| miniqp->miniq2.rcu_state = miniqp->miniq1.rcu_state; |
| miniqp->p_miniq = p_miniq; |
| } |
| EXPORT_SYMBOL(mini_qdisc_pair_init); |