net: remove dev_txq_stats_fold()

After recent changes, (percpu stats on vlan/tunnels...), we dont need
anymore per struct netdev_queue tx_bytes/tx_packets/tx_dropped counters.

Only remaining users are ixgbe, sch_teql, gianfar & macvlan :

1) ixgbe can be converted to use existing tx_ring counters.

2) macvlan incremented txq->tx_dropped, it can use the
dev->stats.tx_dropped counter.

3) sch_teql : almost revert ab35cd4b8f42 (Use net_device internal stats)
    Now we have ndo_get_stats64(), use it, even for "unsigned long"
fields (No need to bring back a struct net_device_stats)

4) gianfar adds a stats structure per tx queue to hold
tx_bytes/tx_packets

This removes a lockdep warning (and possible lockup) in rndis gadget,
calling dev_get_stats() from hard IRQ context.

Ref: http://www.spinics.net/lists/netdev/msg149202.html

Reported-by: Neil Jones <neiljay@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
CC: Sandeep Gopalpet <sandeep.kumar@freescale.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 21 insertions, 34 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index a3ef808b5e36..83507c265e48 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5523,34 +5523,6 @@ void netdev_run_todo(void)
         }
 }
 
-/**
- *      dev_txq_stats_fold - fold tx_queues stats
- *      @dev: device to get statistics from
- *      @stats: struct rtnl_link_stats64 to hold results
- */
-void dev_txq_stats_fold(const struct net_device *dev,
-                        struct rtnl_link_stats64 *stats)
-{
-        u64 tx_bytes = 0, tx_packets = 0, tx_dropped = 0;
-        unsigned int i;
-        struct netdev_queue *txq;
-
-        for (i = 0; i < dev->num_tx_queues; i++) {
-                txq = netdev_get_tx_queue(dev, i);
-                spin_lock_bh(&txq->_xmit_lock);
-                tx_bytes   += txq->tx_bytes;
-                tx_packets += txq->tx_packets;
-                tx_dropped += txq->tx_dropped;
-                spin_unlock_bh(&txq->_xmit_lock);
-        }
-        if (tx_bytes || tx_packets || tx_dropped) {
-                stats->tx_bytes   = tx_bytes;
-                stats->tx_packets = tx_packets;
-                stats->tx_dropped = tx_dropped;
-        }
-}
-EXPORT_SYMBOL(dev_txq_stats_fold);
-
 /* Convert net_device_stats to rtnl_link_stats64.  They have the same
  * fields in the same order, with only the type differing.
  */
@@ -5594,7 +5566,6 @@ struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
         } else {
                 netdev_stats_to_stats64(storage, &dev->stats);
-                dev_txq_stats_fold(dev, storage);
         }
         storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
         return storage;
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index af9360d1f6eb..84ce48eadff4 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -59,6 +59,10 @@ struct teql_master
         struct net_device *dev;
         struct Qdisc *slaves;
         struct list_head master_list;
+        unsigned long   tx_bytes;
+        unsigned long   tx_packets;
+        unsigned long   tx_errors;
+        unsigned long   tx_dropped;
 };
 
 struct teql_sched_data
@@ -274,7 +278,6 @@ static inline int teql_resolve(struct sk_buff *skb,
 static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct teql_master *master = netdev_priv(dev);
-        struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
         struct Qdisc *start, *q;
         int busy;
         int nores;
@@ -314,8 +317,8 @@ restart:
                                         __netif_tx_unlock(slave_txq);
                                         master->slaves = NEXT_SLAVE(q);
                                         netif_wake_queue(dev);
-                                        txq->tx_packets++;
-                                        txq->tx_bytes += length;
+                                        master->tx_packets++;
+                                        master->tx_bytes += length;
                                         return NETDEV_TX_OK;
                                 }
                                 __netif_tx_unlock(slave_txq);
@@ -342,10 +345,10 @@ restart:
                 netif_stop_queue(dev);
                 return NETDEV_TX_BUSY;
         }
-        dev->stats.tx_errors++;
+        master->tx_errors++;
 
 drop:
-        txq->tx_dropped++;
+        master->tx_dropped++;
         dev_kfree_skb(skb);
         return NETDEV_TX_OK;
 }
@@ -398,6 +401,18 @@ static int teql_master_close(struct net_device *dev)
         return 0;
 }
 
+static struct rtnl_link_stats64 *teql_master_stats64(struct net_device *dev,
+                                                     struct rtnl_link_stats64 *stats)
+{
+        struct teql_master *m = netdev_priv(dev);
+
+        stats->tx_packets       = m->tx_packets;
+        stats->tx_bytes         = m->tx_bytes;
+        stats->tx_errors        = m->tx_errors;
+        stats->tx_dropped       = m->tx_dropped;
+        return stats;
+}
+
 static int teql_master_mtu(struct net_device *dev, int new_mtu)
 {
         struct teql_master *m = netdev_priv(dev);
@@ -422,6 +437,7 @@ static const struct net_device_ops teql_netdev_ops = {
         .ndo_open       = teql_master_open,
         .ndo_stop       = teql_master_close,
         .ndo_start_xmit = teql_master_xmit,
+        .ndo_get_stats64 = teql_master_stats64,
         .ndo_change_mtu = teql_master_mtu,
 };