net/mlx5: E-Switch, Enlarge the FDB size for the switchdev mode

The E-Switch FDB size was hard coded to 8k. Change it to be

  min(max eswitch table size, max flow counters * num flow groups)

where the max values are read from the firmware and the number of
flow groups is hard-coded as before this change.

We don't know upfront the division of flows to group. This setup allows
each group to be of size up to the where we want to support (we mandate
pairing of flows with counters for offloading). Thus, we don't expect
multiple occurences for a group which in turn adds steering hops.

Signed-off-by: Or Gerlitz <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Tested-by: Roi Dayan <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>

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

@@ -402,19 +402,18 @@ static int esw_add_fdb_miss_rule(struct mlx5_eswitch *esw)
 }
 
 #define MAX_PF_SQ 256
-#define ESW_OFFLOADS_NUM_ENTRIES (1 << 13) /* 8K */
 #define ESW_OFFLOADS_NUM_GROUPS  4
 
 static int esw_create_offloads_fdb_table(struct mlx5_eswitch *esw, int nvports)
 {
 	int inlen = MLX5_ST_SZ_BYTES(create_flow_group_in);
+	int table_size, ix, esw_size, err = 0;
 	struct mlx5_core_dev *dev = esw->dev;
 	struct mlx5_flow_namespace *root_ns;
 	struct mlx5_flow_table *fdb = NULL;
 	struct mlx5_flow_group *g;
 	u32 *flow_group_in;
 	void *match_criteria;
-	int table_size, ix, err = 0;
 	u32 flags = 0;
 
 	flow_group_in = mlx5_vzalloc(inlen);
@@ -427,15 +426,19 @@ static int esw_create_offloads_fdb_table(struct mlx5_eswitch *esw, int nvports)
 		goto ns_err;
 	}
 
-	esw_debug(dev, "Create offloads FDB table, log_max_size(%d)\n",
-		  MLX5_CAP_ESW_FLOWTABLE_FDB(dev, log_max_ft_size));
+	esw_debug(dev, "Create offloads FDB table, min (max esw size(2^%d), max counters(%d)*groups(%d))\n",
+		  MLX5_CAP_ESW_FLOWTABLE_FDB(dev, log_max_ft_size),
+		  MLX5_CAP_GEN(dev, max_flow_counter), ESW_OFFLOADS_NUM_GROUPS);
+
+	esw_size = min_t(int, MLX5_CAP_GEN(dev, max_flow_counter) * ESW_OFFLOADS_NUM_GROUPS,
+			 1 << MLX5_CAP_ESW_FLOWTABLE_FDB(dev, log_max_ft_size));
 
 	if (MLX5_CAP_ESW_FLOWTABLE_FDB(dev, encap) &&
 	    MLX5_CAP_ESW_FLOWTABLE_FDB(dev, decap))
 		flags |= MLX5_FLOW_TABLE_TUNNEL_EN;
 
 	fdb = mlx5_create_auto_grouped_flow_table(root_ns, FDB_FAST_PATH,
-						  ESW_OFFLOADS_NUM_ENTRIES,
+						  esw_size,
 						  ESW_OFFLOADS_NUM_GROUPS, 0,
 						  flags);
 	if (IS_ERR(fdb)) {