Re: [PATCH net-next v3 5/9] forcedeth: implement ndo_get_stats64() API

This commit implements the ndo_get_stats64() API for forcedeth. Since
these stats are being updated from different contexts (process and
timer), this commit adds protection (locking + atomic variables).

Tested:
  - 16-way SMP x86_64 ->
    RX bytes:7244556582 (7.2 GB)  TX bytes:181904254 (181.9 MB)
  - pktgen + loopback: identical rx_bytes/tx_bytes and rx_packets/tx_packets



Signed-off-by: David Decotigny <redacted>
---
 drivers/net/ethernet/nvidia/forcedeth.c |  182 ++++++++++++++++++++++++-------
 1 files changed, 141 insertions(+), 41 deletions(-)

diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index ee8cce5..a67c1f4 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c

@@ -692,6 +692,21 @@ struct nv_ethtool_stats {
 #define NV_DEV_STATISTICS_V2_COUNT (NV_DEV_STATISTICS_V3_COUNT - 3)
 #define NV_DEV_STATISTICS_V1_COUNT (NV_DEV_STATISTICS_V2_COUNT - 6)
 
+/* driver statistics */
+struct nv_driver_stat {
+	atomic_t delta;  /* increase since last nv_update_stats() */
+	u64 total;  /* cumulative, requires netdev_priv(dev)->stats_lock */
+};