net/mlx5e: Support RSS for GRE tunneled packets

Introduce a new flow table and indirect TIRs which are used to hash the
inner packet headers of GRE tunneled packets.

When a GRE tunneled packet is received, the TTC flow table will match
the new IPv4/6->GRE rules which will forward it to the inner TTC table.
The inner TTC is similar to its counterpart outer TTC table, but
matching the inner packet headers instead of the outer ones (and does
not include the new IPv4/6->GRE rules).
The new rules will not add steering hops since they are added to an
already existing flow group which will be matched regardless of this
patch. Non GRE traffic will not be affected.

The inner flow table will forward the packet to inner indirect TIRs
which hash the inner packet and thus result in RSS for the tunneled
packets.

Testing 8 TCP streams bandwidth over GRE:
System: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
NIC: Mellanox Technologies MT28800 Family [ConnectX-5 Ex]
Before: 21.3 Gbps (Single RQ)
Now   : 90.5 Gbps (RSS spread on 8 RQs)

Signed-off-by: Gal Pressman <galp@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en.h

@@ -620,6 +620,12 @@ enum mlx5e_traffic_types {
 	MLX5E_NUM_INDIR_TIRS = MLX5E_TT_ANY,
 };
 
+enum mlx5e_tunnel_types {
+	MLX5E_TT_IPV4_GRE,
+	MLX5E_TT_IPV6_GRE,
+	MLX5E_NUM_TUNNEL_TT,
+};
+
 enum {
 	MLX5E_STATE_ASYNC_EVENTS_ENABLED,
 	MLX5E_STATE_OPENED,
@@ -679,6 +685,7 @@ struct mlx5e_l2_table {
 struct mlx5e_ttc_table {
 	struct mlx5e_flow_table  ft;
 	struct mlx5_flow_handle	 *rules[MLX5E_NUM_TT];
+	struct mlx5_flow_handle  *tunnel_rules[MLX5E_NUM_TUNNEL_TT];
 };
 
 #define ARFS_HASH_SHIFT BITS_PER_BYTE
@@ -711,6 +718,7 @@ enum {
 	MLX5E_VLAN_FT_LEVEL = 0,
 	MLX5E_L2_FT_LEVEL,
 	MLX5E_TTC_FT_LEVEL,
+	MLX5E_INNER_TTC_FT_LEVEL,
 	MLX5E_ARFS_FT_LEVEL
 };
 
@@ -736,6 +744,7 @@ struct mlx5e_flow_steering {
 	struct mlx5e_vlan_table         vlan;
 	struct mlx5e_l2_table           l2;
 	struct mlx5e_ttc_table          ttc;
+	struct mlx5e_ttc_table          inner_ttc;
 	struct mlx5e_arfs_tables        arfs;
 };
 
@@ -769,6 +778,7 @@ struct mlx5e_priv {
 	u32                        tisn[MLX5E_MAX_NUM_TC];
 	struct mlx5e_rqt           indir_rqt;
 	struct mlx5e_tir           indir_tir[MLX5E_NUM_INDIR_TIRS];
+	struct mlx5e_tir           inner_indir_tir[MLX5E_NUM_INDIR_TIRS];
 	struct mlx5e_tir           direct_tir[MLX5E_MAX_NUM_CHANNELS];
 	u32                        tx_rates[MLX5E_MAX_NUM_SQS];
 	int                        hard_mtu;
@@ -903,7 +913,7 @@ int mlx5e_redirect_rqt(struct mlx5e_priv *priv, u32 rqtn, int sz,
 		       struct mlx5e_redirect_rqt_param rrp);
 void mlx5e_build_indir_tir_ctx_hash(struct mlx5e_params *params,
 				    enum mlx5e_traffic_types tt,
-				    void *tirc);
+				    void *tirc, bool inner);
 
 int mlx5e_open_locked(struct net_device *netdev);
 int mlx5e_close_locked(struct net_device *netdev);
@@ -932,6 +942,12 @@ void mlx5e_set_rx_cq_mode_params(struct mlx5e_params *params,
 void mlx5e_set_rq_type_params(struct mlx5_core_dev *mdev,
 			      struct mlx5e_params *params, u8 rq_type);
 
+static inline bool mlx5e_tunnel_inner_ft_supported(struct mlx5_core_dev *mdev)
+{
+	return (MLX5_CAP_ETH(mdev, tunnel_stateless_gre) &&
+		MLX5_CAP_FLOWTABLE_NIC_RX(mdev, ft_field_support.inner_ip_version));
+}
+
 static inline
 struct mlx5e_tx_wqe *mlx5e_post_nop(struct mlx5_wq_cyc *wq, u32 sqn, u16 *pc)
 {

drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c

@@ -1212,9 +1212,18 @@ static void mlx5e_modify_tirs_hash(struct mlx5e_priv *priv, void *in, int inlen)
 
 	for (tt = 0; tt < MLX5E_NUM_INDIR_TIRS; tt++) {
 		memset(tirc, 0, ctxlen);
-		mlx5e_build_indir_tir_ctx_hash(&priv->channels.params, tt, tirc);
+		mlx5e_build_indir_tir_ctx_hash(&priv->channels.params, tt, tirc, false);
 		mlx5_core_modify_tir(mdev, priv->indir_tir[tt].tirn, in, inlen);
 	}
+
+	if (!mlx5e_tunnel_inner_ft_supported(priv->mdev))
+		return;
+
+	for (tt = 0; tt < MLX5E_NUM_INDIR_TIRS; tt++) {
+		memset(tirc, 0, ctxlen);
+		mlx5e_build_indir_tir_ctx_hash(&priv->channels.params, tt, tirc, true);
+		mlx5_core_modify_tir(mdev, priv->inner_indir_tir[tt].tirn, in, inlen);
+	}
 }
 
 static int mlx5e_set_rxfh(struct net_device *dev, const u32 *indir,