mlx4: add pause frame stats

Check if the pause stats are reported by HW by checking the bitmap.
Calculation is based on the order of strings in main_strings from
ethtool -S. Hopefully the semantics of these stats match the standard..
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_ethtool.c

@@ -1106,6 +1106,24 @@ static int mlx4_en_set_pauseparam(struct net_device *dev,
 	return err;
 }
 
+static void mlx4_en_get_pause_stats(struct net_device *dev,
+				    struct ethtool_pause_stats *stats)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	struct bitmap_iterator it;
+
+	bitmap_iterator_init(&it, priv->stats_bitmap.bitmap, NUM_ALL_STATS);
+
+	spin_lock_bh(&priv->stats_lock);
+	if (test_bit(FLOW_PRIORITY_STATS_IDX_TX_FRAMES,
+		     priv->stats_bitmap.bitmap))
+		stats->tx_pause_frames = priv->tx_flowstats.tx_pause;
+	if (test_bit(FLOW_PRIORITY_STATS_IDX_RX_FRAMES,
+		     priv->stats_bitmap.bitmap))
+		stats->rx_pause_frames = priv->rx_flowstats.rx_pause;
+	spin_unlock_bh(&priv->stats_lock);
+}
+
 static void mlx4_en_get_pauseparam(struct net_device *dev,
 				 struct ethtool_pauseparam *pause)
 {
@@ -2138,6 +2156,7 @@ const struct ethtool_ops mlx4_en_ethtool_ops = {
 	.set_msglevel = mlx4_en_set_msglevel,
 	.get_coalesce = mlx4_en_get_coalesce,
 	.set_coalesce = mlx4_en_set_coalesce,
+	.get_pause_stats = mlx4_en_get_pause_stats,
 	.get_pauseparam = mlx4_en_get_pauseparam,
 	.set_pauseparam = mlx4_en_set_pauseparam,
 	.get_ringparam = mlx4_en_get_ringparam,

drivers/net/ethernet/mellanox/mlx4/mlx4_stats.h

@@ -84,6 +84,11 @@ struct mlx4_en_flow_stats_rx {
 					 MLX4_NUM_PRIORITIES)
 };
 
+#define FLOW_PRIORITY_STATS_IDX_RX_FRAMES	(NUM_MAIN_STATS +	\
+						 NUM_PORT_STATS +	\
+						 NUM_PF_STATS +		\
+						 NUM_FLOW_PRIORITY_STATS_RX)
+
 struct mlx4_en_flow_stats_tx {
 	u64 tx_pause;
 	u64 tx_pause_duration;
@@ -93,6 +98,13 @@ struct mlx4_en_flow_stats_tx {
 					 MLX4_NUM_PRIORITIES)
 };
 
+#define FLOW_PRIORITY_STATS_IDX_TX_FRAMES	(NUM_MAIN_STATS +	\
+						 NUM_PORT_STATS +	\
+						 NUM_PF_STATS +		\
+						 NUM_FLOW_PRIORITY_STATS_RX + \
+						 NUM_FLOW_STATS_RX +	\
+						 NUM_FLOW_PRIORITY_STATS_TX)
+
 #define NUM_FLOW_STATS (NUM_FLOW_STATS_RX + NUM_FLOW_STATS_TX + \
 			NUM_FLOW_PRIORITY_STATS_TX + \
 			NUM_FLOW_PRIORITY_STATS_RX)