r8169: Add software counter for multicast packages

The multicast hardware counter on 8168/8111 chips is only 32 bit while the
statistics in struct rtnl_link_stats64 are 64 bit.  Given that statistics
are requested on an irregular basis, an overflow of the hardware counter
can go unnoticed.  To count even very large numbers of multicast packets
reliably, add a software counter and remove previously applied code to
fill the multicast field requested by @rtl8169_get_stats64 with the values
read from the rx_multicast hardware counter.

Signed-off-by: Corinna Vinschen <vinschen@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index d6d39df5b3dc9db95f43659318b6e78c23e397dd..24dcbe62412a10a457bc5fa7ea8ce0ed1f016221 100644 (file)
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -754,7 +754,6 @@ struct rtl8169_tc_offsets {
        bool    inited;
        __le64  tx_errors;
        __le32  tx_multi_collision;
-       __le32  rx_multicast;
        __le16  tx_aborted;
 };
 
@@ -2326,7 +2325,6 @@ static bool rtl8169_init_counter_offsets(struct net_device *dev)
 
        tp->tc_offset.tx_errors = tp->counters.tx_errors;
        tp->tc_offset.tx_multi_collision = tp->counters.tx_multi_collision;
-       tp->tc_offset.rx_multicast = tp->counters.rx_multicast;
        tp->tc_offset.tx_aborted = tp->counters.tx_aborted;
        tp->tc_offset.inited = true;
 
@@ -7480,6 +7478,9 @@ process_pkt:
                        tp->rx_stats.packets++;
                        tp->rx_stats.bytes += pkt_size;
                        u64_stats_update_end(&tp->rx_stats.syncp);
+
+                       if (skb->pkt_type == PACKET_MULTICAST)
+                               dev->stats.multicast++;
                }
 release_descriptor:
                desc->opts2 = 0;
@@ -7790,7 +7791,6 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
                stats->rx_bytes = tp->rx_stats.bytes;
        } while (u64_stats_fetch_retry_irq(&tp->rx_stats.syncp, start));
 
-
        do {
                start = u64_stats_fetch_begin_irq(&tp->tx_stats.syncp);
                stats->tx_packets = tp->tx_stats.packets;
@@ -7804,6 +7804,7 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
        stats->rx_crc_errors    = dev->stats.rx_crc_errors;
        stats->rx_fifo_errors   = dev->stats.rx_fifo_errors;
        stats->rx_missed_errors = dev->stats.rx_missed_errors;
+       stats->multicast        = dev->stats.multicast;
 
        /*
         * Fetch additonal counter values missing in stats collected by driver
@@ -7819,8 +7820,6 @@ rtl8169_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
                le64_to_cpu(tp->tc_offset.tx_errors);
        stats->collisions = le32_to_cpu(tp->counters.tx_multi_collision) -
                le32_to_cpu(tp->tc_offset.tx_multi_collision);
-       stats->multicast = le32_to_cpu(tp->counters.rx_multicast) -
-               le32_to_cpu(tp->tc_offset.rx_multicast);
        stats->tx_aborted_errors = le16_to_cpu(tp->counters.tx_aborted) -
                le16_to_cpu(tp->tc_offset.tx_aborted);