net/mlx5: Add multipath mode

In order to offload ecmp-on-host scheme where next-hop routes are used,
we will make use of HW LAG. Add accessor function to let upper layers
in the driver to realize if the lag acts in multi-path mode.

Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Author: roidayan

drivers/net/ethernet/mellanox/mlx5/core/Makefile

@@ -30,7 +30,7 @@ mlx5_core-$(CONFIG_MLX5_CORE_EN) += en_main.o en_common.o en_fs.o en_ethtool.o \
 mlx5_core-$(CONFIG_MLX5_EN_ARFS)     += en_arfs.o
 mlx5_core-$(CONFIG_MLX5_EN_RXNFC)    += en_fs_ethtool.o
 mlx5_core-$(CONFIG_MLX5_CORE_EN_DCB) += en_dcbnl.o en/port_buffer.o
-mlx5_core-$(CONFIG_MLX5_ESWITCH)     += en_rep.o en_tc.o en/tc_tun.o lib/port_tun.o
+mlx5_core-$(CONFIG_MLX5_ESWITCH)     += en_rep.o en_tc.o en/tc_tun.o lib/port_tun.o lag_mp.o
 
 #
 # Core extra

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

@@ -9,9 +9,11 @@
 enum {
 	MLX5_LAG_FLAG_ROCE   = 1 << 0,
 	MLX5_LAG_FLAG_SRIOV  = 1 << 1,
+	MLX5_LAG_FLAG_MULTIPATH = 1 << 2,
 };
 
-#define MLX5_LAG_MODE_FLAGS (MLX5_LAG_FLAG_ROCE | MLX5_LAG_FLAG_SRIOV)
+#define MLX5_LAG_MODE_FLAGS (MLX5_LAG_FLAG_ROCE | MLX5_LAG_FLAG_SRIOV |\
+			     MLX5_LAG_FLAG_MULTIPATH)
 
 struct lag_func {
 	struct mlx5_core_dev *dev;

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

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2019 Mellanox Technologies. */
+
+#include <linux/netdevice.h>
+#include "lag.h"
+#include "mlx5_core.h"
+#include "eswitch.h"
+
+static bool __mlx5_lag_is_multipath(struct mlx5_lag *ldev)
+{
+	return !!(ldev->flags & MLX5_LAG_FLAG_MULTIPATH);
+}
+
+bool mlx5_lag_is_multipath(struct mlx5_core_dev *dev)
+{
+	struct mlx5_lag *ldev;
+	bool res;
+
+	ldev = mlx5_lag_dev_get(dev);
+	res  = ldev && __mlx5_lag_is_multipath(ldev);
+
+	return res;
+}

include/linux/mlx5/driver.h

@@ -1041,6 +1041,7 @@ int mlx5_cmd_create_vport_lag(struct mlx5_core_dev *dev);
 int mlx5_cmd_destroy_vport_lag(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_roce(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_sriov(struct mlx5_core_dev *dev);
+bool mlx5_lag_is_multipath(struct mlx5_core_dev *dev);
 bool mlx5_lag_is_active(struct mlx5_core_dev *dev);
 struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev);
 int mlx5_lag_query_cong_counters(struct mlx5_core_dev *dev,