mlx4_en: Controlling FCS header removal

Canceling FCS removal where FW allows for better alignment
of incoming data.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -806,6 +806,10 @@ static int mlx4_en_config_rss_qp(struct mlx4_en_priv *priv, int qpn,
 				qpn, ring->cqn, context);
 	context->db_rec_addr = cpu_to_be64(ring->wqres.db.dma);
 
+	/* Cancel FCS removal if FW allows */
+	if (mdev->dev->caps.flags & MLX4_DEV_CAP_FLAG_FCS_KEEP)
+		context->param3 |= cpu_to_be32(1 << 29);
+
 	err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, context, qp, state);
 	if (err) {
 		mlx4_qp_remove(mdev->dev, qp);

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

@@ -101,6 +101,7 @@ static void dump_dev_cap_flags(struct mlx4_dev *dev, u64 flags)
 		[25] = "Router support",
 		[30] = "IBoE support",
 		[32] = "Unicast loopback support",
+		[34] = "FCS header control",
 		[38] = "Wake On LAN support",
 		[40] = "UDP RSS support",
 		[41] = "Unicast VEP steering support",

include/linux/mlx4/device.h

@@ -75,6 +75,7 @@ enum {
 	MLX4_DEV_CAP_FLAG_UD_MCAST	= 1LL << 21,
 	MLX4_DEV_CAP_FLAG_IBOE		= 1LL << 30,
 	MLX4_DEV_CAP_FLAG_UC_LOOPBACK	= 1LL << 32,
+	MLX4_DEV_CAP_FLAG_FCS_KEEP	= 1LL << 34,
 	MLX4_DEV_CAP_FLAG_WOL		= 1LL << 38,
 	MLX4_DEV_CAP_FLAG_UDP_RSS	= 1LL << 40,
 	MLX4_DEV_CAP_FLAG_VEP_UC_STEER	= 1LL << 41,