igb: Implement reading of reg RQDPC (Receive Queue Drop Packet Count)

Based on the previous patches from Jesper Dangaard Brouer <hawk@comx.dk>

Implement reading the per queue drop stats register
RQDPC (Receive Queue Drop Packet Count).  It counts the number of
packets dropped by a queue due to lack of descriptors available.

Notice RQDPC (Receive Queue Drop Packet Count) stats only gets
incremented, if the DROP_EN bit it set (in the SRRCTL register
for that queue).  If DROP_EN bit is NOT set, then the some what
equivalent count is stored in RNBC (not per queue basis).

The RQDPC register is only 12 bit, thus the precision might
suffer due to overrun in-netween the watchdog polling interval.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
CC: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index b8551a57dd3f..2ae98f91372e 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -96,9 +96,10 @@ static const struct igb_stats igb_gstrings_stats[] = {
 };
 
 #define IGB_QUEUE_STATS_LEN \
-        ((((struct igb_adapter *)netdev_priv(netdev))->num_rx_queues + \
-         ((struct igb_adapter *)netdev_priv(netdev))->num_tx_queues) * \
-        (sizeof(struct igb_queue_stats) / sizeof(u64)))
+        (((((struct igb_adapter *)netdev_priv(netdev))->num_rx_queues)* \
+          (sizeof(struct igb_rx_queue_stats) / sizeof(u64))) + \
+         ((((struct igb_adapter *)netdev_priv(netdev))->num_tx_queues) * \
+          (sizeof(struct igb_tx_queue_stats) / sizeof(u64))))
 #define IGB_GLOBAL_STATS_LEN    \
         sizeof(igb_gstrings_stats) / sizeof(struct igb_stats)
 #define IGB_STATS_LEN (IGB_GLOBAL_STATS_LEN + IGB_QUEUE_STATS_LEN)
@@ -1960,7 +1961,8 @@ static void igb_get_ethtool_stats(struct net_device *netdev,
 {
         struct igb_adapter *adapter = netdev_priv(netdev);
         u64 *queue_stat;
-        int stat_count = sizeof(struct igb_queue_stats) / sizeof(u64);
+        int stat_count_tx = sizeof(struct igb_tx_queue_stats) / sizeof(u64);
+        int stat_count_rx = sizeof(struct igb_rx_queue_stats) / sizeof(u64);
         int j;
         int i;
 
@@ -1973,14 +1975,14 @@ static void igb_get_ethtool_stats(struct net_device *netdev,
         for (j = 0; j < adapter->num_tx_queues; j++) {
                 int k;
                 queue_stat = (u64 *)&adapter->tx_ring[j].tx_stats;
-                for (k = 0; k < stat_count; k++)
+                for (k = 0; k < stat_count_tx; k++)
                         data[i + k] = queue_stat[k];
                 i += k;
         }
         for (j = 0; j < adapter->num_rx_queues; j++) {
                 int k;
                 queue_stat = (u64 *)&adapter->rx_ring[j].rx_stats;
-                for (k = 0; k < stat_count; k++)
+                for (k = 0; k < stat_count_rx; k++)
                         data[i + k] = queue_stat[k];
                 i += k;
         }
@@ -2014,6 +2016,8 @@ static void igb_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
                         p += ETH_GSTRING_LEN;
                         sprintf(p, "rx_queue_%u_bytes", i);
                         p += ETH_GSTRING_LEN;
+                        sprintf(p, "rx_queue_%u_drops", i);
+                        p += ETH_GSTRING_LEN;
                 }
 /*              BUG_ON(p - data != IGB_STATS_LEN * ETH_GSTRING_LEN); */
                 break;