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>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index a060610..602078b 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -6667,8 +6667,6 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,
 			  struct ixgbe_adapter *adapter,
 			  struct ixgbe_ring *tx_ring)
 {
-	struct net_device *netdev = tx_ring->netdev;
-	struct netdev_queue *txq;
 	unsigned int first;
 	unsigned int tx_flags = 0;
 	u8 hdr_len = 0;
@@ -6765,9 +6763,6 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,
 		/* add the ATR filter if ATR is on */
 		if (test_bit(__IXGBE_TX_FDIR_INIT_DONE, &tx_ring->state))
 			ixgbe_atr(tx_ring, skb, tx_flags, protocol);
-		txq = netdev_get_tx_queue(netdev, tx_ring->queue_index);
-		txq->tx_bytes += skb->len;
-		txq->tx_packets++;
 		ixgbe_tx_queue(tx_ring, tx_flags, count, skb->len, hdr_len);
 		ixgbe_maybe_stop_tx(tx_ring, DESC_NEEDED);
 
@@ -6925,8 +6920,6 @@ static struct rtnl_link_stats64 *ixgbe_get_stats64(struct net_device *netdev,
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
 	int i;
 
-	/* accurate rx/tx bytes/packets stats */
-	dev_txq_stats_fold(netdev, stats);
 	rcu_read_lock();
 	for (i = 0; i < adapter->num_rx_queues; i++) {
 		struct ixgbe_ring *ring = ACCESS_ONCE(adapter->rx_ring[i]);
@@ -6943,6 +6936,22 @@ static struct rtnl_link_stats64 *ixgbe_get_stats64(struct net_device *netdev,
 			stats->rx_bytes   += bytes;
 		}
 	}
+
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		struct ixgbe_ring *ring = ACCESS_ONCE(adapter->tx_ring[i]);
+		u64 bytes, packets;
+		unsigned int start;
+
+		if (ring) {
+			do {
+				start = u64_stats_fetch_begin_bh(&ring->syncp);
+				packets = ring->stats.packets;
+				bytes   = ring->stats.bytes;
+			} while (u64_stats_fetch_retry_bh(&ring->syncp, start));
+			stats->tx_packets += packets;
+			stats->tx_bytes   += bytes;
+		}
+	}
 	rcu_read_unlock();
 	/* following stats updated by ixgbe_watchdog_task() */
 	stats->multicast	= netdev->stats.multicast;