forked from Minki/linux
1b34ec43c9
These macros contain a hidden goto, and are thus extremely error prone and make code hard to audit. Signed-off-by: David S. Miller <davem@davemloft.net>
910 lines
22 KiB
C
910 lines
22 KiB
C
/*
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* net/sched/sch_generic.c Generic packet scheduler routines.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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* Jamal Hadi Salim, <hadi@cyberus.ca> 990601
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* - Ingress support
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*/
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#include <linux/bitops.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/init.h>
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#include <linux/rcupdate.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <net/pkt_sched.h>
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#include <net/dst.h>
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/* Main transmission queue. */
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/* Modifications to data participating in scheduling must be protected with
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* qdisc_lock(qdisc) spinlock.
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*
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* The idea is the following:
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* - enqueue, dequeue are serialized via qdisc root lock
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* - ingress filtering is also serialized via qdisc root lock
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* - updates to tree and tree walking are only done under the rtnl mutex.
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*/
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static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
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{
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skb_dst_force(skb);
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q->gso_skb = skb;
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q->qstats.requeues++;
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q->q.qlen++; /* it's still part of the queue */
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__netif_schedule(q);
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return 0;
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}
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static inline struct sk_buff *dequeue_skb(struct Qdisc *q)
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{
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struct sk_buff *skb = q->gso_skb;
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if (unlikely(skb)) {
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struct net_device *dev = qdisc_dev(q);
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struct netdev_queue *txq;
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/* check the reason of requeuing without tx lock first */
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txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
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if (!netif_xmit_frozen_or_stopped(txq)) {
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q->gso_skb = NULL;
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q->q.qlen--;
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} else
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skb = NULL;
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} else {
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skb = q->dequeue(q);
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}
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return skb;
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}
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static inline int handle_dev_cpu_collision(struct sk_buff *skb,
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struct netdev_queue *dev_queue,
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struct Qdisc *q)
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{
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int ret;
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if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) {
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/*
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* Same CPU holding the lock. It may be a transient
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* configuration error, when hard_start_xmit() recurses. We
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* detect it by checking xmit owner and drop the packet when
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* deadloop is detected. Return OK to try the next skb.
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*/
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kfree_skb(skb);
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if (net_ratelimit())
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pr_warning("Dead loop on netdevice %s, fix it urgently!\n",
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dev_queue->dev->name);
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ret = qdisc_qlen(q);
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} else {
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/*
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* Another cpu is holding lock, requeue & delay xmits for
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* some time.
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*/
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__this_cpu_inc(softnet_data.cpu_collision);
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ret = dev_requeue_skb(skb, q);
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}
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return ret;
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}
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/*
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* Transmit one skb, and handle the return status as required. Holding the
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* __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this
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* function.
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*
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* Returns to the caller:
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* 0 - queue is empty or throttled.
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* >0 - queue is not empty.
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*/
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int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
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struct net_device *dev, struct netdev_queue *txq,
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spinlock_t *root_lock)
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{
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int ret = NETDEV_TX_BUSY;
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/* And release qdisc */
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spin_unlock(root_lock);
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HARD_TX_LOCK(dev, txq, smp_processor_id());
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if (!netif_xmit_frozen_or_stopped(txq))
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ret = dev_hard_start_xmit(skb, dev, txq);
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HARD_TX_UNLOCK(dev, txq);
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spin_lock(root_lock);
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if (dev_xmit_complete(ret)) {
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/* Driver sent out skb successfully or skb was consumed */
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ret = qdisc_qlen(q);
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} else if (ret == NETDEV_TX_LOCKED) {
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/* Driver try lock failed */
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ret = handle_dev_cpu_collision(skb, txq, q);
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} else {
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/* Driver returned NETDEV_TX_BUSY - requeue skb */
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if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit()))
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pr_warning("BUG %s code %d qlen %d\n",
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dev->name, ret, q->q.qlen);
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ret = dev_requeue_skb(skb, q);
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}
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if (ret && netif_xmit_frozen_or_stopped(txq))
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ret = 0;
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return ret;
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}
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/*
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* NOTE: Called under qdisc_lock(q) with locally disabled BH.
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*
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* __QDISC_STATE_RUNNING guarantees only one CPU can process
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* this qdisc at a time. qdisc_lock(q) serializes queue accesses for
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* this queue.
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*
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* netif_tx_lock serializes accesses to device driver.
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*
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* qdisc_lock(q) and netif_tx_lock are mutually exclusive,
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* if one is grabbed, another must be free.
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*
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* Note, that this procedure can be called by a watchdog timer
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*
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* Returns to the caller:
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* 0 - queue is empty or throttled.
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* >0 - queue is not empty.
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*
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*/
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static inline int qdisc_restart(struct Qdisc *q)
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{
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struct netdev_queue *txq;
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struct net_device *dev;
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spinlock_t *root_lock;
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struct sk_buff *skb;
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/* Dequeue packet */
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skb = dequeue_skb(q);
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if (unlikely(!skb))
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return 0;
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WARN_ON_ONCE(skb_dst_is_noref(skb));
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root_lock = qdisc_lock(q);
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dev = qdisc_dev(q);
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txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
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return sch_direct_xmit(skb, q, dev, txq, root_lock);
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}
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void __qdisc_run(struct Qdisc *q)
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{
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int quota = weight_p;
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while (qdisc_restart(q)) {
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/*
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* Ordered by possible occurrence: Postpone processing if
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* 1. we've exceeded packet quota
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* 2. another process needs the CPU;
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*/
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if (--quota <= 0 || need_resched()) {
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__netif_schedule(q);
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break;
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}
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}
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qdisc_run_end(q);
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}
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unsigned long dev_trans_start(struct net_device *dev)
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{
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unsigned long val, res = dev->trans_start;
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unsigned int i;
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for (i = 0; i < dev->num_tx_queues; i++) {
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val = netdev_get_tx_queue(dev, i)->trans_start;
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if (val && time_after(val, res))
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res = val;
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}
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dev->trans_start = res;
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return res;
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}
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EXPORT_SYMBOL(dev_trans_start);
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static void dev_watchdog(unsigned long arg)
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{
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struct net_device *dev = (struct net_device *)arg;
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netif_tx_lock(dev);
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if (!qdisc_tx_is_noop(dev)) {
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if (netif_device_present(dev) &&
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netif_running(dev) &&
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netif_carrier_ok(dev)) {
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int some_queue_timedout = 0;
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unsigned int i;
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unsigned long trans_start;
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for (i = 0; i < dev->num_tx_queues; i++) {
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struct netdev_queue *txq;
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txq = netdev_get_tx_queue(dev, i);
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/*
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* old device drivers set dev->trans_start
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*/
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trans_start = txq->trans_start ? : dev->trans_start;
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if (netif_xmit_stopped(txq) &&
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time_after(jiffies, (trans_start +
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dev->watchdog_timeo))) {
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some_queue_timedout = 1;
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txq->trans_timeout++;
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break;
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}
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}
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if (some_queue_timedout) {
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WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
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dev->name, netdev_drivername(dev), i);
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dev->netdev_ops->ndo_tx_timeout(dev);
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}
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if (!mod_timer(&dev->watchdog_timer,
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round_jiffies(jiffies +
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dev->watchdog_timeo)))
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dev_hold(dev);
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}
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}
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netif_tx_unlock(dev);
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dev_put(dev);
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}
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void __netdev_watchdog_up(struct net_device *dev)
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{
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if (dev->netdev_ops->ndo_tx_timeout) {
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if (dev->watchdog_timeo <= 0)
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dev->watchdog_timeo = 5*HZ;
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if (!mod_timer(&dev->watchdog_timer,
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round_jiffies(jiffies + dev->watchdog_timeo)))
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dev_hold(dev);
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}
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}
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static void dev_watchdog_up(struct net_device *dev)
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{
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__netdev_watchdog_up(dev);
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}
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static void dev_watchdog_down(struct net_device *dev)
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{
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netif_tx_lock_bh(dev);
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if (del_timer(&dev->watchdog_timer))
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dev_put(dev);
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netif_tx_unlock_bh(dev);
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}
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/**
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* netif_carrier_on - set carrier
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* @dev: network device
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*
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* Device has detected that carrier.
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*/
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void netif_carrier_on(struct net_device *dev)
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{
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if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
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if (dev->reg_state == NETREG_UNINITIALIZED)
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return;
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linkwatch_fire_event(dev);
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if (netif_running(dev))
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__netdev_watchdog_up(dev);
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}
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}
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EXPORT_SYMBOL(netif_carrier_on);
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/**
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* netif_carrier_off - clear carrier
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* @dev: network device
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*
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* Device has detected loss of carrier.
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*/
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void netif_carrier_off(struct net_device *dev)
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{
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if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
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if (dev->reg_state == NETREG_UNINITIALIZED)
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return;
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linkwatch_fire_event(dev);
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}
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}
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EXPORT_SYMBOL(netif_carrier_off);
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/**
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* netif_notify_peers - notify network peers about existence of @dev
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* @dev: network device
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*
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* Generate traffic such that interested network peers are aware of
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* @dev, such as by generating a gratuitous ARP. This may be used when
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* a device wants to inform the rest of the network about some sort of
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* reconfiguration such as a failover event or virtual machine
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* migration.
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*/
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void netif_notify_peers(struct net_device *dev)
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{
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rtnl_lock();
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call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
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rtnl_unlock();
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}
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EXPORT_SYMBOL(netif_notify_peers);
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/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
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under all circumstances. It is difficult to invent anything faster or
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cheaper.
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*/
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static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
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{
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kfree_skb(skb);
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return NET_XMIT_CN;
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}
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static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
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{
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return NULL;
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}
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struct Qdisc_ops noop_qdisc_ops __read_mostly = {
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.id = "noop",
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.priv_size = 0,
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.enqueue = noop_enqueue,
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.dequeue = noop_dequeue,
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.peek = noop_dequeue,
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.owner = THIS_MODULE,
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};
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static struct netdev_queue noop_netdev_queue = {
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.qdisc = &noop_qdisc,
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.qdisc_sleeping = &noop_qdisc,
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};
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struct Qdisc noop_qdisc = {
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.enqueue = noop_enqueue,
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.dequeue = noop_dequeue,
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.flags = TCQ_F_BUILTIN,
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.ops = &noop_qdisc_ops,
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.list = LIST_HEAD_INIT(noop_qdisc.list),
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.q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
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.dev_queue = &noop_netdev_queue,
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.busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
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};
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EXPORT_SYMBOL(noop_qdisc);
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static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
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.id = "noqueue",
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.priv_size = 0,
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.enqueue = noop_enqueue,
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.dequeue = noop_dequeue,
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.peek = noop_dequeue,
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.owner = THIS_MODULE,
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};
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static struct Qdisc noqueue_qdisc;
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static struct netdev_queue noqueue_netdev_queue = {
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.qdisc = &noqueue_qdisc,
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.qdisc_sleeping = &noqueue_qdisc,
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};
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static struct Qdisc noqueue_qdisc = {
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.enqueue = NULL,
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.dequeue = noop_dequeue,
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.flags = TCQ_F_BUILTIN,
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.ops = &noqueue_qdisc_ops,
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.list = LIST_HEAD_INIT(noqueue_qdisc.list),
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.q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
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.dev_queue = &noqueue_netdev_queue,
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.busylock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock),
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};
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static const u8 prio2band[TC_PRIO_MAX + 1] = {
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1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
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};
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/* 3-band FIFO queue: old style, but should be a bit faster than
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generic prio+fifo combination.
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*/
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#define PFIFO_FAST_BANDS 3
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/*
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* Private data for a pfifo_fast scheduler containing:
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* - queues for the three band
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* - bitmap indicating which of the bands contain skbs
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*/
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struct pfifo_fast_priv {
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u32 bitmap;
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struct sk_buff_head q[PFIFO_FAST_BANDS];
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};
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/*
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* Convert a bitmap to the first band number where an skb is queued, where:
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* bitmap=0 means there are no skbs on any band.
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* bitmap=1 means there is an skb on band 0.
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* bitmap=7 means there are skbs on all 3 bands, etc.
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*/
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static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
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static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv,
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int band)
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{
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return priv->q + band;
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}
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static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc)
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{
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if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) {
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int band = prio2band[skb->priority & TC_PRIO_MAX];
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struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
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struct sk_buff_head *list = band2list(priv, band);
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priv->bitmap |= (1 << band);
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qdisc->q.qlen++;
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return __qdisc_enqueue_tail(skb, qdisc, list);
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}
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return qdisc_drop(skb, qdisc);
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}
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static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
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{
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struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
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int band = bitmap2band[priv->bitmap];
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if (likely(band >= 0)) {
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struct sk_buff_head *list = band2list(priv, band);
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struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list);
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qdisc->q.qlen--;
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if (skb_queue_empty(list))
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priv->bitmap &= ~(1 << band);
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return skb;
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}
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return NULL;
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}
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static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
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{
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struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
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int band = bitmap2band[priv->bitmap];
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if (band >= 0) {
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struct sk_buff_head *list = band2list(priv, band);
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return skb_peek(list);
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}
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return NULL;
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}
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static void pfifo_fast_reset(struct Qdisc *qdisc)
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{
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int prio;
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struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
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for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
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__qdisc_reset_queue(qdisc, band2list(priv, prio));
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priv->bitmap = 0;
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qdisc->qstats.backlog = 0;
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qdisc->q.qlen = 0;
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}
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static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
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{
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struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
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|
|
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++)
|
|
skb_queue_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);
|
|
|
|
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
|
|
struct Qdisc_ops *ops)
|
|
{
|
|
void *p;
|
|
struct Qdisc *sch;
|
|
unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size;
|
|
int err = -ENOBUFS;
|
|
|
|
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;
|
|
}
|
|
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;
|
|
}
|
|
}
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
bool sync_needed = false;
|
|
|
|
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);
|
|
sync_needed |= !dev->dismantle;
|
|
}
|
|
|
|
/* 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
|
|
*/
|
|
if (sync_needed)
|
|
synchronize_net();
|
|
|
|
/* 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);
|
|
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;
|
|
|
|
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));
|
|
}
|