igb: fix stats handling

There are currently some problems with igb.

- On 32bit arches, maintaining 64bit counters without proper
synchronization between writers and readers.

- Stats updated every two seconds, as reported by Jesper.
   (Jesper provided a patch for this)

- Potential problem between worker thread and ethtool -S

This patch uses u64_stats_sync, and convert everything to be 64bit safe,
SMP safe, even on 32bit arches. It integrates Jesper idea of providing
accurate stats at the time user reads them.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index 44e0ff1494e0..edab9c442399 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -159,6 +159,7 @@ struct igb_tx_queue_stats {
         u64 packets;
         u64 bytes;
         u64 restart_queue;
+        u64 restart_queue2;
 };
 
 struct igb_rx_queue_stats {
@@ -210,11 +211,14 @@ struct igb_ring {
                 /* TX */
                 struct {
                         struct igb_tx_queue_stats tx_stats;
+                        struct u64_stats_sync tx_syncp;
+                        struct u64_stats_sync tx_syncp2;
                         bool detect_tx_hung;
                 };
                 /* RX */
                 struct {
                         struct igb_rx_queue_stats rx_stats;
+                        struct u64_stats_sync rx_syncp;
                         u32 rx_buffer_len;
                 };
         };
@@ -288,6 +292,9 @@ struct igb_adapter {
         struct timecompare compare;
         struct hwtstamp_config hwtstamp_config;
 
+        spinlock_t stats64_lock;
+        struct rtnl_link_stats64 stats64;
+
         /* structs defined in e1000_hw.h */
         struct e1000_hw hw;
         struct e1000_hw_stats stats;
@@ -357,7 +364,7 @@ extern netdev_tx_t igb_xmit_frame_ring_adv(struct sk_buff *, struct igb_ring *);
 extern void igb_unmap_and_free_tx_resource(struct igb_ring *,
                                            struct igb_buffer *);
 extern void igb_alloc_rx_buffers_adv(struct igb_ring *, int);
-extern void igb_update_stats(struct igb_adapter *);
+extern void igb_update_stats(struct igb_adapter *, struct rtnl_link_stats64 *);
 extern bool igb_has_link(struct igb_adapter *adapter);
 extern void igb_set_ethtool_ops(struct net_device *);
 extern void igb_power_up_link(struct igb_adapter *);