net/mlx5: E-Switch, Enable setting goto slow path chain action

A pre-step for the tc offloads code to use this when a neigh is
not available for encap rules.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -60,6 +60,7 @@
 	MLX5_CAP_ESW_FLOWTABLE(dev, fdb_multi_path_to_table)
 
 #define FDB_MAX_CHAIN 3
+#define FDB_SLOW_PATH_CHAIN (FDB_MAX_CHAIN + 1)
 #define FDB_MAX_PRIO 16
 
 struct vport_ingress {
@@ -356,6 +357,7 @@ static inline int  mlx5_eswitch_enable_sriov(struct mlx5_eswitch *esw, int nvfs,
 static inline void mlx5_eswitch_disable_sriov(struct mlx5_eswitch *esw) {}
 
 #define FDB_MAX_CHAIN 1
+#define FDB_SLOW_PATH_CHAIN (FDB_MAX_CHAIN + 1)
 #define FDB_MAX_PRIO 1
 
 #endif /* CONFIG_MLX5_ESWITCH */

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

@@ -671,6 +671,9 @@ esw_get_prio_table(struct mlx5_eswitch *esw, u32 chain, u16 prio, int level)
 	int table_prio, l = 0;
 	u32 flags = 0;
 
+	if (chain == FDB_SLOW_PATH_CHAIN)
+		return esw->fdb_table.offloads.slow_fdb;
+
 	mutex_lock(&esw->fdb_table.offloads.fdb_prio_lock);
 
 	fdb = fdb_prio_table(esw, chain, prio, level).fdb;
@@ -730,6 +733,9 @@ esw_put_prio_table(struct mlx5_eswitch *esw, u32 chain, u16 prio, int level)
 {
 	int l;
 
+	if (chain == FDB_SLOW_PATH_CHAIN)
+		return;
+
 	mutex_lock(&esw->fdb_table.offloads.fdb_prio_lock);
 
 	for (l = level; l >= 0; l--) {