Merge branch 'mlxsw-support-for-nexthop-group-statistics'

Petr Machata says:

====================
mlxsw: Support for nexthop group statistics

ECMP is a fundamental component in L3 designs. However, it's fragile. Many
factors influence whether an ECMP group will operate as intended: hash
policy (i.e. the set of fields that contribute to ECMP hash calculation),
neighbor validity, hash seed (which might lead to polarization) or the type
of ECMP group used (hash-threshold or resilient).

At the same time, collection of statistics that would help an operator
determine that the group performs as desired, is difficult.

Support for nexthop group statistics and their HW collection has been
introduced recently. In this patch set, add HW stats collection support
to mlxsw.

This patchset progresses as follows:

- Patches #1 and #2 add nexthop IDs to notifiers.
- Patches #3 and #4 are code-shaping.
- Patches #5, #6 and #7 adjust the flow counter code.
- Patches #8 and #9 add HW nexthop counters.
- Patch #10 adjusts the HW counter code to allow sharing the same counter
  for several resilient group buckets with the same NH ID.
- Patch #11 adds a selftest.
====================

Link: https://lore.kernel.org/r/cover.1709901020.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -176,13 +176,15 @@ MLXSW_ITEM32(tx, hdr, fid, 0x08, 16, 16);
 MLXSW_ITEM32(tx, hdr, type, 0x0C, 0, 4);
 
 int mlxsw_sp_flow_counter_get(struct mlxsw_sp *mlxsw_sp,
-			      unsigned int counter_index, u64 *packets,
-			      u64 *bytes)
+			      unsigned int counter_index, bool clear,
+			      u64 *packets, u64 *bytes)
 {
+	enum mlxsw_reg_mgpc_opcode op = clear ? MLXSW_REG_MGPC_OPCODE_CLEAR :
+						MLXSW_REG_MGPC_OPCODE_NOP;
 	char mgpc_pl[MLXSW_REG_MGPC_LEN];
 	int err;
 
-	mlxsw_reg_mgpc_pack(mgpc_pl, counter_index, MLXSW_REG_MGPC_OPCODE_NOP,
+	mlxsw_reg_mgpc_pack(mgpc_pl, counter_index, op,
 			    MLXSW_REG_FLOW_COUNTER_SET_TYPE_PACKETS_BYTES);
 	err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(mgpc), mgpc_pl);
 	if (err)

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -706,8 +706,8 @@ int mlxsw_sp_port_kill_vid(struct net_device *dev,
 int mlxsw_sp_port_vlan_set(struct mlxsw_sp_port *mlxsw_sp_port, u16 vid_begin,
 			   u16 vid_end, bool is_member, bool untagged);
 int mlxsw_sp_flow_counter_get(struct mlxsw_sp *mlxsw_sp,
-			      unsigned int counter_index, u64 *packets,
-			      u64 *bytes);
+			      unsigned int counter_index, bool clear,
+			      u64 *packets, u64 *bytes);
 int mlxsw_sp_flow_counter_alloc(struct mlxsw_sp *mlxsw_sp,
 				unsigned int *p_counter_index);
 void mlxsw_sp_flow_counter_free(struct mlxsw_sp *mlxsw_sp,

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

@@ -1024,7 +1024,7 @@ int mlxsw_sp_acl_rule_get_stats(struct mlxsw_sp *mlxsw_sp,
 	rulei = mlxsw_sp_acl_rule_rulei(rule);
 	if (rulei->counter_valid) {
 		err = mlxsw_sp_flow_counter_get(mlxsw_sp, rulei->counter_index,
-						&current_packets,
+						false, &current_packets,
 						&current_bytes);
 		if (err)
 			return err;

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

@@ -1181,9 +1181,11 @@ static int mlxsw_sp_dpipe_table_adj_counters_update(void *priv, bool enable)
 	char ratr_pl[MLXSW_REG_RATR_LEN];
 	struct mlxsw_sp *mlxsw_sp = priv;
 	struct mlxsw_sp_nexthop *nh;
+	unsigned int n_done = 0;
 	u32 adj_hash_index = 0;
 	u32 adj_index = 0;
 	u32 adj_size = 0;
+	int err;
 
 	mlxsw_sp_nexthop_for_each(nh, mlxsw_sp->router) {
 		if (!mlxsw_sp_nexthop_is_forward(nh) ||
@@ -1192,15 +1194,27 @@ static int mlxsw_sp_dpipe_table_adj_counters_update(void *priv, bool enable)
 
 		mlxsw_sp_nexthop_indexes(nh, &adj_index, &adj_size,
 					 &adj_hash_index);
-		if (enable)
-			mlxsw_sp_nexthop_counter_alloc(mlxsw_sp, nh);
-		else
-			mlxsw_sp_nexthop_counter_free(mlxsw_sp, nh);
+		if (enable) {
+			err = mlxsw_sp_nexthop_counter_enable(mlxsw_sp, nh);
+			if (err)
+				goto err_counter_enable;
+		} else {
+			mlxsw_sp_nexthop_counter_disable(mlxsw_sp, nh);
+		}
 		mlxsw_sp_nexthop_eth_update(mlxsw_sp,
 					    adj_index + adj_hash_index, nh,
 					    true, ratr_pl);
+		n_done++;
 	}
 	return 0;
+
+err_counter_enable:
+	mlxsw_sp_nexthop_for_each(nh, mlxsw_sp->router) {
+		if (!n_done--)
+			break;
+		mlxsw_sp_nexthop_counter_disable(mlxsw_sp, nh);
+	}
+	return err;
 }
 
 static u64

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

@@ -361,7 +361,7 @@ static int mlxsw_sp_mr_tcam_route_stats(struct mlxsw_sp *mlxsw_sp,
 	struct mlxsw_sp_mr_tcam_route *route = route_priv;
 
 	return mlxsw_sp_flow_counter_get(mlxsw_sp, route->counter_index,
-					 packets, bytes);
+					 false, packets, bytes);
 }
 
 static int