fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / net / sched / sch_generic.c
index 8c01e02..bc116bd 100644 (file)
@@ -14,7 +14,6 @@
 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <linux/bitops.h>
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
    The idea is the following:
    - enqueue, dequeue are serialized via top level device
      spinlock dev->queue_lock.
-   - tree walking is protected by read_lock_bh(qdisc_tree_lock)
+   - tree walking is protected by read_lock(qdisc_tree_lock)
      and this lock is used only in process context.
-   - updates to tree are made under rtnl semaphore or
-     from softirq context (__qdisc_destroy rcu-callback)
-     hence this lock needs local bh disabling.
+   - updates to tree are made only under rtnl semaphore,
+     hence this lock may be made without local bh disabling.
 
    qdisc_tree_lock must be grabbed BEFORE dev->queue_lock!
  */
@@ -58,23 +56,23 @@ DEFINE_RWLOCK(qdisc_tree_lock);
 
 void qdisc_lock_tree(struct net_device *dev)
 {
-       write_lock_bh(&qdisc_tree_lock);
+       write_lock(&qdisc_tree_lock);
        spin_lock_bh(&dev->queue_lock);
 }
 
 void qdisc_unlock_tree(struct net_device *dev)
 {
        spin_unlock_bh(&dev->queue_lock);
-       write_unlock_bh(&qdisc_tree_lock);
+       write_unlock(&qdisc_tree_lock);
 }
 
 /* 
    dev->queue_lock serializes queue accesses for this device
    AND dev->qdisc pointer itself.
 
-   dev->xmit_lock serializes accesses to device driver.
+   netif_tx_lock serializes accesses to device driver.
 
-   dev->queue_lock and dev->xmit_lock are mutually exclusive,
+   dev->queue_lock and netif_tx_lock are mutually exclusive,
    if one is grabbed, another must be free.
  */
 
@@ -90,14 +88,17 @@ void qdisc_unlock_tree(struct net_device *dev)
    NOTE: Called under dev->queue_lock with locally disabled BH.
 */
 
-int qdisc_restart(struct net_device *dev)
+static inline int qdisc_restart(struct net_device *dev)
 {
        struct Qdisc *q = dev->qdisc;
        struct sk_buff *skb;
 
        /* Dequeue packet */
-       if ((skb = q->dequeue(q)) != NULL) {
+       if (((skb = dev->gso_skb)) || ((skb = q->dequeue(q)))) {
                unsigned nolock = (dev->features & NETIF_F_LLTX);
+
+               dev->gso_skb = NULL;
+
                /*
                 * When the driver has LLTX set it does its own locking
                 * in start_xmit. No need to add additional overhead by
@@ -108,7 +109,7 @@ int qdisc_restart(struct net_device *dev)
                 * will be requeued.
                 */
                if (!nolock) {
-                       if (!spin_trylock(&dev->xmit_lock)) {
+                       if (!netif_tx_trylock(dev)) {
                        collision:
                                /* So, someone grabbed the driver. */
                                
@@ -126,8 +127,6 @@ int qdisc_restart(struct net_device *dev)
                                __get_cpu_var(netdev_rx_stat).cpu_collision++;
                                goto requeue;
                        }
-                       /* Remember that the driver is grabbed by us. */
-                       dev->xmit_lock_owner = smp_processor_id();
                }
                
                {
@@ -136,14 +135,11 @@ int qdisc_restart(struct net_device *dev)
 
                        if (!netif_queue_stopped(dev)) {
                                int ret;
-                               if (netdev_nit)
-                                       dev_queue_xmit_nit(skb, dev);
 
-                               ret = dev->hard_start_xmit(skb, dev);
+                               ret = dev_hard_start_xmit(skb, dev);
                                if (ret == NETDEV_TX_OK) { 
                                        if (!nolock) {
-                                               dev->xmit_lock_owner = -1;
-                                               spin_unlock(&dev->xmit_lock);
+                                               netif_tx_unlock(dev);
                                        }
                                        spin_lock(&dev->queue_lock);
                                        return -1;
@@ -157,8 +153,7 @@ int qdisc_restart(struct net_device *dev)
                        /* NETDEV_TX_BUSY - we need to requeue */
                        /* Release the driver */
                        if (!nolock) { 
-                               dev->xmit_lock_owner = -1;
-                               spin_unlock(&dev->xmit_lock);
+                               netif_tx_unlock(dev);
                        } 
                        spin_lock(&dev->queue_lock);
                        q = dev->qdisc;
@@ -175,32 +170,50 @@ int qdisc_restart(struct net_device *dev)
                 */
 
 requeue:
-               q->ops->requeue(skb, q);
+               if (skb->next)
+                       dev->gso_skb = skb;
+               else
+                       q->ops->requeue(skb, q);
                netif_schedule(dev);
                return 1;
        }
+       BUG_ON((int) q->q.qlen < 0);
        return q->q.qlen;
 }
 
+void __qdisc_run(struct net_device *dev)
+{
+       if (unlikely(dev->qdisc == &noop_qdisc))
+               goto out;
+
+       while (qdisc_restart(dev) < 0 && !netif_queue_stopped(dev))
+               /* NOTHING */;
+
+out:
+       clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state);
+}
+
 static void dev_watchdog(unsigned long arg)
 {
        struct net_device *dev = (struct net_device *)arg;
 
-       spin_lock(&dev->xmit_lock);
+       netif_tx_lock(dev);
        if (dev->qdisc != &noop_qdisc) {
                if (netif_device_present(dev) &&
                    netif_running(dev) &&
                    netif_carrier_ok(dev)) {
                        if (netif_queue_stopped(dev) &&
-                           (jiffies - dev->trans_start) > dev->watchdog_timeo) {
-                               printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", dev->name);
+                           time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) {
+
+                               printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n",
+                                      dev->name);
                                dev->tx_timeout(dev);
                        }
                        if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo))
                                dev_hold(dev);
                }
        }
-       spin_unlock(&dev->xmit_lock);
+       netif_tx_unlock(dev);
 
        dev_put(dev);
 }
@@ -224,17 +237,29 @@ void __netdev_watchdog_up(struct net_device *dev)
 
 static void dev_watchdog_up(struct net_device *dev)
 {
-       spin_lock_bh(&dev->xmit_lock);
        __netdev_watchdog_up(dev);
-       spin_unlock_bh(&dev->xmit_lock);
 }
 
 static void dev_watchdog_down(struct net_device *dev)
 {
-       spin_lock_bh(&dev->xmit_lock);
+       netif_tx_lock_bh(dev);
        if (del_timer(&dev->watchdog_timer))
-               __dev_put(dev);
-       spin_unlock_bh(&dev->xmit_lock);
+               dev_put(dev);
+       netif_tx_unlock_bh(dev);
+}
+
+void netif_carrier_on(struct net_device *dev)
+{
+       if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state))
+               linkwatch_fire_event(dev);
+       if (netif_running(dev))
+               __netdev_watchdog_up(dev);
+}
+
+void netif_carrier_off(struct net_device *dev)
+{
+       if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state))
+               linkwatch_fire_event(dev);
 }
 
 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
@@ -242,31 +267,27 @@ static void dev_watchdog_down(struct net_device *dev)
    cheaper.
  */
 
-static int
-noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
+static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
 {
        kfree_skb(skb);
        return NET_XMIT_CN;
 }
 
-static struct sk_buff *
-noop_dequeue(struct Qdisc * qdisc)
+static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
 {
        return NULL;
 }
 
-static int
-noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
+static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
 {
        if (net_ratelimit())
-               printk(KERN_DEBUG "%s deferred output. It is buggy.\n", skb->dev->name);
+               printk(KERN_DEBUG "%s deferred output. It is buggy.\n",
+                      skb->dev->name);
        kfree_skb(skb);
        return NET_XMIT_CN;
 }
 
 struct Qdisc_ops noop_qdisc_ops = {
-       .next           =       NULL,
-       .cl_ops         =       NULL,
        .id             =       "noop",
        .priv_size      =       0,
        .enqueue        =       noop_enqueue,
@@ -284,8 +305,6 @@ struct Qdisc noop_qdisc = {
 };
 
 static struct Qdisc_ops noqueue_qdisc_ops = {
-       .next           =       NULL,
-       .cl_ops         =       NULL,
        .id             =       "noqueue",
        .priv_size      =       0,
        .enqueue        =       noop_enqueue,
@@ -310,97 +329,86 @@ static const u8 prio2band[TC_PRIO_MAX+1] =
    generic prio+fifo combination.
  */
 
-static int
-pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)
+#define PFIFO_FAST_BANDS 3
+
+static inline struct sk_buff_head *prio2list(struct sk_buff *skb,
+                                            struct Qdisc *qdisc)
 {
        struct sk_buff_head *list = qdisc_priv(qdisc);
+       return list + prio2band[skb->priority & TC_PRIO_MAX];
+}
 
-       list += prio2band[skb->priority&TC_PRIO_MAX];
+static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)
+{
+       struct sk_buff_head *list = prio2list(skb, qdisc);
 
-       if (list->qlen < qdisc->dev->tx_queue_len) {
-               __skb_queue_tail(list, skb);
+       if (skb_queue_len(list) < qdisc->dev->tx_queue_len) {
                qdisc->q.qlen++;
-               qdisc->bstats.bytes += skb->len;
-               qdisc->bstats.packets++;
-               return 0;
+               return __qdisc_enqueue_tail(skb, qdisc, list);
        }
-       qdisc->qstats.drops++;
-       kfree_skb(skb);
-       return NET_XMIT_DROP;
+
+       return qdisc_drop(skb, qdisc);
 }
 
-static struct sk_buff *
-pfifo_fast_dequeue(struct Qdisc* qdisc)
+static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc)
 {
        int prio;
        struct sk_buff_head *list = qdisc_priv(qdisc);
-       struct sk_buff *skb;
 
-       for (prio = 0; prio < 3; prio++, list++) {
-               skb = __skb_dequeue(list);
-               if (skb) {
+       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
+               if (!skb_queue_empty(list + prio)) {
                        qdisc->q.qlen--;
-                       return skb;
+                       return __qdisc_dequeue_head(qdisc, list + prio);
                }
        }
+
        return NULL;
 }
 
-static int
-pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
+static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
 {
-       struct sk_buff_head *list = qdisc_priv(qdisc);
-
-       list += prio2band[skb->priority&TC_PRIO_MAX];
-
-       __skb_queue_head(list, skb);
        qdisc->q.qlen++;
-       qdisc->qstats.requeues++;
-       return 0;
+       return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc));
 }
 
-static void
-pfifo_fast_reset(struct Qdisc* qdisc)
+static void pfifo_fast_reset(struct Qdisc* qdisc)
 {
        int prio;
        struct sk_buff_head *list = qdisc_priv(qdisc);
 
-       for (prio=0; prio < 3; prio++)
-               skb_queue_purge(list+prio);
+       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
+               __qdisc_reset_queue(qdisc, list + prio);
+
+       qdisc->qstats.backlog = 0;
        qdisc->q.qlen = 0;
 }
 
 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
 {
-       unsigned char    *b = skb->tail;
-       struct tc_prio_qopt opt;
+       struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
 
-       opt.bands = 3; 
        memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1);
        RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
        return skb->len;
 
 rtattr_failure:
-       skb_trim(skb, b - skb->data);
        return -1;
 }
 
 static int pfifo_fast_init(struct Qdisc *qdisc, struct rtattr *opt)
 {
-       int i;
+       int prio;
        struct sk_buff_head *list = qdisc_priv(qdisc);
 
-       for (i=0; i<3; i++)
-               skb_queue_head_init(list+i);
+       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
+               skb_queue_head_init(list + prio);
 
        return 0;
 }
 
 static struct Qdisc_ops pfifo_fast_ops = {
-       .next           =       NULL,
-       .cl_ops         =       NULL,
        .id             =       "pfifo_fast",
-       .priv_size      =       3 * sizeof(struct sk_buff_head),
+       .priv_size      =       PFIFO_FAST_BANDS * sizeof(struct sk_buff_head),
        .enqueue        =       pfifo_fast_enqueue,
        .dequeue        =       pfifo_fast_dequeue,
        .requeue        =       pfifo_fast_requeue,
@@ -410,24 +418,22 @@ static struct Qdisc_ops pfifo_fast_ops = {
        .owner          =       THIS_MODULE,
 };
 
-struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
+struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops)
 {
        void *p;
        struct Qdisc *sch;
-       int size;
+       unsigned int size;
+       int err = -ENOBUFS;
 
        /* ensure that the Qdisc and the private data are 32-byte aligned */
-       size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
-       size += ops->priv_size + QDISC_ALIGN_CONST;
+       size = QDISC_ALIGN(sizeof(*sch));
+       size += ops->priv_size + (QDISC_ALIGNTO - 1);
 
-       p = kmalloc(size, GFP_KERNEL);
+       p = kzalloc(size, GFP_KERNEL);
        if (!p)
-               return NULL;
-       memset(p, 0, size);
-
-       sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST) 
-                              & ~QDISC_ALIGN_CONST);
-       sch->padded = (char *)sch - (char *)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);
@@ -438,11 +444,27 @@ struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
        dev_hold(dev);
        sch->stats_lock = &dev->queue_lock;
        atomic_set(&sch->refcnt, 1);
+
+       return sch;
+errout:
+       return ERR_PTR(-err);
+}
+
+struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops,
+                                unsigned int parentid)
+{
+       struct Qdisc *sch;
+       
+       sch = qdisc_alloc(dev, ops);
+       if (IS_ERR(sch))
+               goto errout;
+       sch->parent = parentid;
+
        if (!ops->init || ops->init(sch, NULL) == 0)
                return sch;
 
-       dev_put(dev);
-       kfree(p);
+       qdisc_destroy(sch);
+errout:
        return NULL;
 }
 
@@ -462,20 +484,6 @@ void qdisc_reset(struct Qdisc *qdisc)
 static void __qdisc_destroy(struct rcu_head *head)
 {
        struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu);
-       struct Qdisc_ops  *ops = qdisc->ops;
-
-#ifdef CONFIG_NET_ESTIMATOR
-       gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
-#endif
-       write_lock(&qdisc_tree_lock);
-       if (ops->reset)
-               ops->reset(qdisc);
-       if (ops->destroy)
-               ops->destroy(qdisc);
-       write_unlock(&qdisc_tree_lock);
-       module_put(ops->owner);
-
-       dev_put(qdisc->dev);
        kfree((char *) qdisc - qdisc->padded);
 }
 
@@ -483,32 +491,23 @@ static void __qdisc_destroy(struct rcu_head *head)
 
 void qdisc_destroy(struct Qdisc *qdisc)
 {
-       struct list_head cql = LIST_HEAD_INIT(cql);
-       struct Qdisc *cq, *q, *n;
+       struct Qdisc_ops  *ops = qdisc->ops;
 
        if (qdisc->flags & TCQ_F_BUILTIN ||
-               !atomic_dec_and_test(&qdisc->refcnt))
+           !atomic_dec_and_test(&qdisc->refcnt))
                return;
 
-       if (!list_empty(&qdisc->list)) {
-               if (qdisc->ops->cl_ops == NULL)
-                       list_del(&qdisc->list);
-               else
-                       list_move(&qdisc->list, &cql);
-       }
-
-       /* unlink inner qdiscs from dev->qdisc_list immediately */
-       list_for_each_entry(cq, &cql, list)
-               list_for_each_entry_safe(q, n, &qdisc->dev->qdisc_list, list)
-                       if (TC_H_MAJ(q->parent) == TC_H_MAJ(cq->handle)) {
-                               if (q->ops->cl_ops == NULL)
-                                       list_del_init(&q->list);
-                               else
-                                       list_move_tail(&q->list, &cql);
-                       }
-       list_for_each_entry_safe(cq, n, &cql, list)
-               list_del_init(&cq->list);
+       list_del(&qdisc->list);
+#ifdef CONFIG_NET_ESTIMATOR
+       gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
+#endif
+       if (ops->reset)
+               ops->reset(qdisc);
+       if (ops->destroy)
+               ops->destroy(qdisc);
 
+       module_put(ops->owner);
+       dev_put(qdisc->dev);
        call_rcu(&qdisc->q_rcu, __qdisc_destroy);
 }
 
@@ -523,22 +522,27 @@ void dev_activate(struct net_device *dev)
        if (dev->qdisc_sleeping == &noop_qdisc) {
                struct Qdisc *qdisc;
                if (dev->tx_queue_len) {
-                       qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops);
+                       qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops,
+                                                 TC_H_ROOT);
                        if (qdisc == NULL) {
                                printk(KERN_INFO "%s: activation failed\n", dev->name);
                                return;
                        }
-                       write_lock_bh(&qdisc_tree_lock);
+                       write_lock(&qdisc_tree_lock);
                        list_add_tail(&qdisc->list, &dev->qdisc_list);
-                       write_unlock_bh(&qdisc_tree_lock);
+                       write_unlock(&qdisc_tree_lock);
                } else {
                        qdisc =  &noqueue_qdisc;
                }
-               write_lock_bh(&qdisc_tree_lock);
+               write_lock(&qdisc_tree_lock);
                dev->qdisc_sleeping = qdisc;
-               write_unlock_bh(&qdisc_tree_lock);
+               write_unlock(&qdisc_tree_lock);
        }
 
+       if (!netif_carrier_ok(dev))
+               /* Delay activation until next carrier-on event */
+               return;
+
        spin_lock_bh(&dev->queue_lock);
        rcu_assign_pointer(dev->qdisc, dev->qdisc_sleeping);
        if (dev->qdisc != &noqueue_qdisc) {
@@ -562,10 +566,17 @@ void dev_deactivate(struct net_device *dev)
 
        dev_watchdog_down(dev);
 
-       while (test_bit(__LINK_STATE_SCHED, &dev->state))
+       /* Wait for outstanding dev_queue_xmit calls. */
+       synchronize_rcu();
+
+       /* Wait for outstanding qdisc_run calls. */
+       while (test_bit(__LINK_STATE_QDISC_RUNNING, &dev->state))
                yield();
 
-       spin_unlock_wait(&dev->xmit_lock);
+       if (dev->gso_skb) {
+               kfree_skb(dev->gso_skb);
+               dev->gso_skb = NULL;
+       }
 }
 
 void dev_init_scheduler(struct net_device *dev)
@@ -598,12 +609,11 @@ void dev_shutdown(struct net_device *dev)
        qdisc_unlock_tree(dev);
 }
 
-EXPORT_SYMBOL(__netdev_watchdog_up);
+EXPORT_SYMBOL(netif_carrier_on);
+EXPORT_SYMBOL(netif_carrier_off);
 EXPORT_SYMBOL(noop_qdisc);
-EXPORT_SYMBOL(noop_qdisc_ops);
 EXPORT_SYMBOL(qdisc_create_dflt);
 EXPORT_SYMBOL(qdisc_destroy);
 EXPORT_SYMBOL(qdisc_reset);
-EXPORT_SYMBOL(qdisc_restart);
 EXPORT_SYMBOL(qdisc_lock_tree);
 EXPORT_SYMBOL(qdisc_unlock_tree);