mlxsw: spectrum_qdisc: Clean stats recursively when priomap changes

On Spectrum, there are no per-TC TX counters. Instead, mlxsw uses per-prio
counters and aggregates them according to the priomap. Therefore when
priomap changes, the counter base values need to be reset to reflect the
change. Previously, this was only done for the sole child qdisc, but a
following patch makes RED and TBF classful. Thus apply the request to the
whole sub-tree.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c

@@ -1169,6 +1169,31 @@ mlxsw_sp_qdisc_prio_check_params(struct mlxsw_sp_port *mlxsw_sp_port,
 	return __mlxsw_sp_qdisc_ets_check_params(p->bands);
 }
 
+static struct mlxsw_sp_qdisc *
+mlxsw_sp_qdisc_walk_cb_clean_stats(struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
+				   void *mlxsw_sp_port)
+{
+	u64 backlog;
+
+	if (mlxsw_sp_qdisc->ops) {
+		backlog = mlxsw_sp_qdisc->stats_base.backlog;
+		if (mlxsw_sp_qdisc->ops->clean_stats)
+			mlxsw_sp_qdisc->ops->clean_stats(mlxsw_sp_port,
+							 mlxsw_sp_qdisc);
+		mlxsw_sp_qdisc->stats_base.backlog = backlog;
+	}
+
+	return NULL;
+}
+
+static void
+mlxsw_sp_qdisc_tree_clean_stats(struct mlxsw_sp_port *mlxsw_sp_port,
+				struct mlxsw_sp_qdisc *mlxsw_sp_qdisc)
+{
+	mlxsw_sp_qdisc_walk(mlxsw_sp_qdisc, mlxsw_sp_qdisc_walk_cb_clean_stats,
+			    mlxsw_sp_port);
+}
+
 static int
 __mlxsw_sp_qdisc_ets_replace(struct mlxsw_sp_port *mlxsw_sp_port,
 			     struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
@@ -1181,7 +1206,7 @@ __mlxsw_sp_qdisc_ets_replace(struct mlxsw_sp_port *mlxsw_sp_port,
 	struct mlxsw_sp_qdisc_ets_band *ets_band;
 	struct mlxsw_sp_qdisc *child_qdisc;
 	u8 old_priomap, new_priomap;
-	int i, band, backlog;
+	int i, band;
 	int err;
 
 	if (!ets_data) {
@@ -1229,13 +1254,9 @@ __mlxsw_sp_qdisc_ets_replace(struct mlxsw_sp_port *mlxsw_sp_port,
 
 		ets_band->prio_bitmap = new_priomap;
 
-		if (old_priomap != new_priomap &&
-		    child_qdisc->ops && child_qdisc->ops->clean_stats) {
-			backlog = child_qdisc->stats_base.backlog;
-			child_qdisc->ops->clean_stats(mlxsw_sp_port,
-						      child_qdisc);
-			child_qdisc->stats_base.backlog = backlog;
-		}
+		if (old_priomap != new_priomap)
+			mlxsw_sp_qdisc_tree_clean_stats(mlxsw_sp_port,
+							child_qdisc);
 
 		err = mlxsw_sp_qdisc_future_fifo_replace(mlxsw_sp_port, handle,
 							 band, child_qdisc);