From: Nogah Frankel <nogahf@mellanox.com>
Date: Wed, 28 Feb 2018 10:45:01 +0100
Subject: mlxsw: spectrum: qdiscs: Collect stats for sch_red based on priomap
Patch-mainline: v4.17-rc1
Git-commit: 04cc0bf5d6ceb0ff19e8636fb39695620e587b06
References: bsc#1112374

Priority counters count packets according to their packet priority.
Collect the stats for sch_red based on these counters, so the qdisc bstats
will be the sum of counters matching the priorities marked in the qdisc
priomap.
Changing the mapping of the priorities to bands while traffic is running
can result in losing the stats of the bands qdiscs from their last dump
call to this change, as if the qdisc was unoffloaded and re-offloaded. It
will not affect the traffic behaviour according to sch_red.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c |   69 +++++++++++++------
 1 file changed, 50 insertions(+), 19 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c
@@ -208,6 +208,23 @@ mlxsw_sp_qdisc_get_xstats(struct mlxsw_s
 	return -EOPNOTSUPP;
 }
 
+static void
+mlxsw_sp_qdisc_bstats_per_priority_get(struct mlxsw_sp_port_xstats *xstats,
+				       u8 prio_bitmap, u64 *tx_packets,
+				       u64 *tx_bytes)
+{
+	int i;
+
+	*tx_packets = 0;
+	*tx_bytes = 0;
+	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
+		if (prio_bitmap & BIT(i)) {
+			*tx_packets += xstats->tx_packets[i];
+			*tx_bytes += xstats->tx_bytes[i];
+		}
+	}
+}
+
 static int
 mlxsw_sp_tclass_congestion_enable(struct mlxsw_sp_port *mlxsw_sp_port,
 				  int tclass_num, u32 min, u32 max,
@@ -253,17 +270,16 @@ mlxsw_sp_setup_tc_qdisc_red_clean_stats(
 	u8 tclass_num = mlxsw_sp_qdisc->tclass_num;
 	struct mlxsw_sp_qdisc_stats *stats_base;
 	struct mlxsw_sp_port_xstats *xstats;
-	struct rtnl_link_stats64 *stats;
 	struct red_stats *red_base;
 
 	xstats = &mlxsw_sp_port->periodic_hw_stats.xstats;
-	stats = &mlxsw_sp_port->periodic_hw_stats.stats;
 	stats_base = &mlxsw_sp_qdisc->stats_base;
 	red_base = &mlxsw_sp_qdisc->xstats_base.red;
 
-	stats_base->tx_packets = stats->tx_packets;
-	stats_base->tx_bytes = stats->tx_bytes;
-
+	mlxsw_sp_qdisc_bstats_per_priority_get(xstats,
+					       mlxsw_sp_qdisc->prio_bitmap,
+					       &stats_base->tx_packets,
+					       &stats_base->tx_bytes);
 	red_base->prob_mark = xstats->ecn;
 	red_base->prob_drop = xstats->wred_drop[tclass_num];
 	red_base->pdrop = xstats->tail_drop[tclass_num];
@@ -380,14 +396,16 @@ mlxsw_sp_qdisc_get_red_stats(struct mlxs
 	u8 tclass_num = mlxsw_sp_qdisc->tclass_num;
 	struct mlxsw_sp_qdisc_stats *stats_base;
 	struct mlxsw_sp_port_xstats *xstats;
-	struct rtnl_link_stats64 *stats;
 
 	xstats = &mlxsw_sp_port->periodic_hw_stats.xstats;
-	stats = &mlxsw_sp_port->periodic_hw_stats.stats;
 	stats_base = &mlxsw_sp_qdisc->stats_base;
 
-	tx_bytes = stats->tx_bytes - stats_base->tx_bytes;
-	tx_packets = stats->tx_packets - stats_base->tx_packets;
+	mlxsw_sp_qdisc_bstats_per_priority_get(xstats,
+					       mlxsw_sp_qdisc->prio_bitmap,
+					       &tx_packets, &tx_bytes);
+	tx_bytes = tx_bytes - stats_base->tx_bytes;
+	tx_packets = tx_packets - stats_base->tx_packets;
+
 	overlimits = xstats->wred_drop[tclass_num] + xstats->ecn -
 		     stats_base->overlimits;
 	drops = xstats->wred_drop[tclass_num] + xstats->tail_drop[tclass_num] -
@@ -493,18 +511,31 @@ mlxsw_sp_qdisc_prio_replace(struct mlxsw
 			    void *params)
 {
 	struct tc_prio_qopt_offload_params *p = params;
-	int tclass, i;
+	struct mlxsw_sp_qdisc *child_qdisc;
+	int tclass, i, band;
+	u8 old_priomap;
 	int err;
 
-	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++)
-		mlxsw_sp_port->tclass_qdiscs[i].prio_bitmap = 0;
-
-	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
-		tclass = MLXSW_SP_PRIO_BAND_TO_TCLASS(p->priomap[i]);
-		err = mlxsw_sp_port_prio_tc_set(mlxsw_sp_port, i, tclass);
-		if (err)
-			return err;
-		mlxsw_sp_port->tclass_qdiscs[tclass].prio_bitmap |= BIT(i);
+	for (band = 0; band < p->bands; band++) {
+		tclass = MLXSW_SP_PRIO_BAND_TO_TCLASS(band);
+		child_qdisc = &mlxsw_sp_port->tclass_qdiscs[tclass];
+		old_priomap = child_qdisc->prio_bitmap;
+		child_qdisc->prio_bitmap = 0;
+		for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
+			if (p->priomap[i] == band) {
+				child_qdisc->prio_bitmap |= BIT(i);
+				if (BIT(i) & old_priomap)
+					continue;
+				err = mlxsw_sp_port_prio_tc_set(mlxsw_sp_port,
+								i, tclass);
+				if (err)
+					return err;
+			}
+		}
+		if (old_priomap != child_qdisc->prio_bitmap &&
+		    child_qdisc->ops && child_qdisc->ops->clean_stats)
+			child_qdisc->ops->clean_stats(mlxsw_sp_port,
+						      child_qdisc);
 	}
 
 	return 0;