net/mlx4_en: Re-design multicast attachments flow

Currently, for every change in the net device multicast list, the driver
detaches all the addresses from the HW device, and then attaches the
updated list. This behavior is wrong from two aspects: first, it causes
a load of firmware commands and second, there is period of time where
the correct addresses are not attached, which turned into packet loss.

To improve - a copy of the multicast list is saved by the driver. For
every change in the multicast list, the multicast list copy is used
to find the delta between those two lists and add or remove multicast
addresses as needed.

Reported-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Cc: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.co.il>
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 225c20d47900..1bb00cd22d42 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -404,6 +404,18 @@ struct mlx4_en_perf_stats {
 #define NUM_PERF_COUNTERS		6
 };
 
+enum mlx4_en_mclist_act {
+	MCLIST_NONE,
+	MCLIST_REM,
+	MCLIST_ADD,
+};
+
+struct mlx4_en_mc_list {
+	struct list_head	list;
+	enum mlx4_en_mclist_act	action;
+	u8			addr[ETH_ALEN];
+};
+
 struct mlx4_en_frag_info {
 	u16 frag_size;
 	u16 frag_prefix_size;
@@ -489,8 +501,8 @@ struct mlx4_en_priv {
 	struct mlx4_en_pkt_stats pkstats;
 	struct mlx4_en_port_stats port_stats;
 	u64 stats_bitmap;
-	char *mc_addrs;
-	int mc_addrs_cnt;
+	struct list_head mc_list;
+	struct list_head curr_list;
 	struct mlx4_en_stat_out_mbox hw_stats;
 	int vids[128];
 	bool wol;