mlxsw: spectrum_router: Support nexthop group hardware statistics

When hw_stats is set on a group, install nexthop counters on members of a
group.

Counter allocation request is moved from nexthop object initialization to
the update code. The previous placement made sense: when the counters are
enabled by dpipe, the counters are installed to all existing nexthops and
all nexthops created from then on get them. For the finer-grained nexthop
group statistics, this is unsuitable. The existing placement was kept for
the IPv4 and IPv6 nexthops.

Resilient group replacement emits a pre_replace notification, and then any
bucket_replace notifications if there were any replacements at all. If the
group is balanced and the nexthop composition of the replaced group didn't
change, there will be no such notifiers. Therefore hook to the pre_replace
notifier and mark all buckets for update, to un/install the counters.

When reporting deltas for resilient groups, use the nexthop ID that we
stored in a previous patch to look up to which nexthop a bucket
contributes.

Co-developed-by: Ido Schimmel <[email protected]>
Signed-off-by: Ido Schimmel <[email protected]>
Signed-off-by: Petr Machata <[email protected]>
Link: https://lore.kernel.org/r/87495a72f187df2e5d491d02729c550d235fcc85.1709901020.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <[email protected]>

Author: pmachata

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

@@ -3108,7 +3108,8 @@ struct mlxsw_sp_nexthop_group_info {
 	int sum_norm_weight;
 	u8 adj_index_valid:1,
 	   gateway:1, /* routes using the group use a gateway */
-	   is_resilient:1;
+	   is_resilient:1,
+	   hw_stats:1;
 	struct list_head list; /* member in nh_res_grp_list */
 	struct mlxsw_sp_nexthop nexthops[] __counted_by(count);
 };
@@ -3189,15 +3190,17 @@ mlxsw_sp_nexthop_counter_free(struct mlxsw_sp *mlxsw_sp,
 int mlxsw_sp_nexthop_counter_enable(struct mlxsw_sp *mlxsw_sp,
 				    struct mlxsw_sp_nexthop *nh)
 {
+	const char *table_adj = MLXSW_SP_DPIPE_TABLE_NAME_ADJ;
 	struct mlxsw_sp_nexthop_counter *nhct;
 	struct devlink *devlink;
+	bool dpipe_stats;
 
 	if (nh->counter)
 		return 0;
 
 	devlink = priv_to_devlink(mlxsw_sp->core);
-	if (!devlink_dpipe_table_counter_enabled(devlink,
-						 MLXSW_SP_DPIPE_TABLE_NAME_ADJ))
+	dpipe_stats = devlink_dpipe_table_counter_enabled(devlink, table_adj);
+	if (!(nh->nhgi->hw_stats || dpipe_stats))
 		return 0;
 
 	nhct = mlxsw_sp_nexthop_counter_alloc(mlxsw_sp);
@@ -3217,14 +3220,23 @@ void mlxsw_sp_nexthop_counter_disable(struct mlxsw_sp *mlxsw_sp,
 	nh->counter = NULL;
 }
 
+static int mlxsw_sp_nexthop_counter_update(struct mlxsw_sp *mlxsw_sp,
+					   struct mlxsw_sp_nexthop *nh)
+{
+	if (nh->nhgi->hw_stats)
+		return mlxsw_sp_nexthop_counter_enable(mlxsw_sp, nh);
+	mlxsw_sp_nexthop_counter_disable(mlxsw_sp, nh);
+	return 0;
+}
+
 int mlxsw_sp_nexthop_counter_get(struct mlxsw_sp *mlxsw_sp,
 				 struct mlxsw_sp_nexthop *nh, u64 *p_counter)
 {
 	if (!nh->counter)
 		return -EINVAL;
 
 	return mlxsw_sp_flow_counter_get(mlxsw_sp, nh->counter->counter_index,
-					 false, p_counter, NULL);
+					 true, p_counter, NULL);
 }
 
 struct mlxsw_sp_nexthop *mlxsw_sp_nexthop_next(struct mlxsw_sp_router *router,
@@ -3786,13 +3798,18 @@ mlxsw_sp_nexthop_group_update(struct mlxsw_sp *mlxsw_sp,
 		nh = &nhgi->nexthops[i];
 
 		if (!nh->should_offload) {
+			mlxsw_sp_nexthop_counter_disable(mlxsw_sp, nh);
 			nh->offloaded = 0;
 			continue;
 		}
 
 		if (nh->update || reallocate) {
 			int err = 0;
 
+			err = mlxsw_sp_nexthop_counter_update(mlxsw_sp, nh);
+			if (err)
+				return err;
+
 			err = mlxsw_sp_nexthop_update(mlxsw_sp, adj_index, nh,
 						      true, ratr_pl);
 			if (err)
@@ -5052,7 +5069,6 @@ mlxsw_sp_nexthop_obj_init(struct mlxsw_sp *mlxsw_sp,
 		break;
 	}
 
-	mlxsw_sp_nexthop_counter_enable(mlxsw_sp, nh);
 	list_add_tail(&nh->router_list_node, &mlxsw_sp->router->nexthop_list);
 	nh->ifindex = dev->ifindex;
 	nh->id = nh_obj->id;
@@ -5077,7 +5093,6 @@ mlxsw_sp_nexthop_obj_init(struct mlxsw_sp *mlxsw_sp,
 
 err_type_init:
 	list_del(&nh->router_list_node);
-	mlxsw_sp_nexthop_counter_disable(mlxsw_sp, nh);
 	return err;
 }
 
@@ -5100,6 +5115,7 @@ mlxsw_sp_nexthop_obj_group_info_init(struct mlxsw_sp *mlxsw_sp,
 	struct mlxsw_sp_nexthop_group_info *nhgi;
 	struct mlxsw_sp_nexthop *nh;
 	bool is_resilient = false;
+	bool hw_stats = false;
 	unsigned int nhs;
 	int err, i;
 
@@ -5109,9 +5125,11 @@ mlxsw_sp_nexthop_obj_group_info_init(struct mlxsw_sp *mlxsw_sp,
 		break;
 	case NH_NOTIFIER_INFO_TYPE_GRP:
 		nhs = info->nh_grp->num_nh;
+		hw_stats = info->nh_grp->hw_stats;
 		break;
 	case NH_NOTIFIER_INFO_TYPE_RES_TABLE:
 		nhs = info->nh_res_table->num_nh_buckets;
+		hw_stats = info->nh_res_table->hw_stats;
 		is_resilient = true;
 		break;
 	default:
@@ -5126,6 +5144,7 @@ mlxsw_sp_nexthop_obj_group_info_init(struct mlxsw_sp *mlxsw_sp,
 	nhgi->gateway = mlxsw_sp_nexthop_obj_is_gateway(mlxsw_sp, info);
 	nhgi->is_resilient = is_resilient;
 	nhgi->count = nhs;
+	nhgi->hw_stats = hw_stats;
 	for (i = 0; i < nhgi->count; i++) {
 		struct nh_notifier_single_info *nh_obj;
 		int weight;
@@ -5347,6 +5366,43 @@ mlxsw_sp_nexthop_obj_group_replace(struct mlxsw_sp *mlxsw_sp,
 	return err;
 }
 
+static int mlxsw_sp_nexthop_obj_res_group_pre(struct mlxsw_sp *mlxsw_sp,
+					      struct nh_notifier_info *info)
+{
+	struct nh_notifier_grp_info *grp_info = info->nh_grp;
+	struct mlxsw_sp_nexthop_group_info *nhgi;
+	struct mlxsw_sp_nexthop_group *nh_grp;
+	int err;
+	int i;
+
+	nh_grp = mlxsw_sp_nexthop_obj_group_lookup(mlxsw_sp, info->id);
+	if (!nh_grp)
+		return 0;
+	nhgi = nh_grp->nhgi;
+
+	if (nhgi->hw_stats == grp_info->hw_stats)
+		return 0;
+
+	nhgi->hw_stats = grp_info->hw_stats;
+
+	for (i = 0; i < nhgi->count; i++) {
+		struct mlxsw_sp_nexthop *nh = &nhgi->nexthops[i];
+
+		if (nh->offloaded)
+			nh->update = 1;
+	}
+
+	err = mlxsw_sp_nexthop_group_refresh(mlxsw_sp, nh_grp);
+	if (err)
+		goto err_group_refresh;
+
+	return 0;
+
+err_group_refresh:
+	nhgi->hw_stats = !grp_info->hw_stats;
+	return err;
+}
+
 static int mlxsw_sp_nexthop_obj_new(struct mlxsw_sp *mlxsw_sp,
 				    struct nh_notifier_info *info)
 {
@@ -5523,6 +5579,79 @@ static int mlxsw_sp_nexthop_obj_bucket_replace(struct mlxsw_sp *mlxsw_sp,
 	return err;
 }
 
+static void
+mlxsw_sp_nexthop_obj_mp_hw_stats_get(struct mlxsw_sp *mlxsw_sp,
+				     struct mlxsw_sp_nexthop_group_info *nhgi,
+				     struct nh_notifier_grp_hw_stats_info *info)
+{
+	int nhi;
+
+	for (nhi = 0; nhi < info->num_nh; nhi++) {
+		struct mlxsw_sp_nexthop *nh = &nhgi->nexthops[nhi];
+		u64 packets;
+		int err;
+
+		err = mlxsw_sp_nexthop_counter_get(mlxsw_sp, nh, &packets);
+		if (err)
+			continue;
+
+		nh_grp_hw_stats_report_delta(info, nhi, packets);
+	}
+}
+
+static void
+mlxsw_sp_nexthop_obj_res_hw_stats_get(struct mlxsw_sp *mlxsw_sp,
+				      struct mlxsw_sp_nexthop_group_info *nhgi,
+				      struct nh_notifier_grp_hw_stats_info *info)
+{
+	int nhi = -1;
+	int bucket;
+
+	for (bucket = 0; bucket < nhgi->count; bucket++) {
+		struct mlxsw_sp_nexthop *nh = &nhgi->nexthops[bucket];
+		u64 packets;
+		int err;
+
+		if (nhi == -1 || info->stats[nhi].id != nh->id) {
+			for (nhi = 0; nhi < info->num_nh; nhi++)
+				if (info->stats[nhi].id == nh->id)
+					break;
+			if (WARN_ON_ONCE(nhi == info->num_nh)) {
+				nhi = -1;
+				continue;
+			}
+		}
+
+		err = mlxsw_sp_nexthop_counter_get(mlxsw_sp, nh, &packets);
+		if (err)
+			continue;
+
+		nh_grp_hw_stats_report_delta(info, nhi, packets);
+	}
+}
+
+static void mlxsw_sp_nexthop_obj_hw_stats_get(struct mlxsw_sp *mlxsw_sp,
+					      struct nh_notifier_info *info)
+{
+	struct mlxsw_sp_nexthop_group_info *nhgi;
+	struct mlxsw_sp_nexthop_group *nh_grp;
+
+	if (info->type != NH_NOTIFIER_INFO_TYPE_GRP_HW_STATS)
+		return;
+
+	nh_grp = mlxsw_sp_nexthop_obj_group_lookup(mlxsw_sp, info->id);
+	if (!nh_grp)
+		return;
+	nhgi = nh_grp->nhgi;
+
+	if (nhgi->is_resilient)
+		mlxsw_sp_nexthop_obj_res_hw_stats_get(mlxsw_sp, nhgi,
+						      info->nh_grp_hw_stats);
+	else
+		mlxsw_sp_nexthop_obj_mp_hw_stats_get(mlxsw_sp, nhgi,
+						     info->nh_grp_hw_stats);
+}
+
 static int mlxsw_sp_nexthop_obj_event(struct notifier_block *nb,
 				      unsigned long event, void *ptr)
 {
@@ -5538,6 +5667,10 @@ static int mlxsw_sp_nexthop_obj_event(struct notifier_block *nb,
 	mutex_lock(&router->lock);
 
 	switch (event) {
+	case NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE:
+		err = mlxsw_sp_nexthop_obj_res_group_pre(router->mlxsw_sp,
+							 info);
+		break;
 	case NEXTHOP_EVENT_REPLACE:
 		err = mlxsw_sp_nexthop_obj_new(router->mlxsw_sp, info);
 		break;
@@ -5548,6 +5681,9 @@ static int mlxsw_sp_nexthop_obj_event(struct notifier_block *nb,
 		err = mlxsw_sp_nexthop_obj_bucket_replace(router->mlxsw_sp,
 							  info);
 		break;
+	case NEXTHOP_EVENT_HW_STATS_REPORT_DELTA:
+		mlxsw_sp_nexthop_obj_hw_stats_get(router->mlxsw_sp, info);
+		break;
 	default:
 		break;
 	}