net/mlx5e: TC, add support for meter mtu offload

Initialize the meter object with the TC police mtu parameter.
Use the hardware range destination to compare the pkt len to the mtu setting.
Assign the range destination hit/miss ft to the police conform/exceed
attributes.
Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/police.c

@@ -3,6 +3,7 @@
 
 #include "act.h"
 #include "en/tc_priv.h"
+#include "fs_core.h"
 
 static bool police_act_validate_control(enum flow_action_id act_id,
 					struct netlink_ext_ack *extack)
@@ -71,6 +72,8 @@ fill_meter_params_from_act(const struct flow_action_entry *act,
 		params->mode = MLX5_RATE_LIMIT_PPS;
 		params->rate = act->police.rate_pkt_ps;
 		params->burst = act->police.burst_pkt;
+	} else if (act->police.mtu) {
+		params->mtu = act->police.mtu;
 	} else {
 		return -EOPNOTSUPP;
 	}
@@ -84,14 +87,25 @@ tc_act_parse_police(struct mlx5e_tc_act_parse_state *parse_state,
 		    struct mlx5e_priv *priv,
 		    struct mlx5_flow_attr *attr)
 {
+	enum mlx5_flow_namespace_type ns =  mlx5e_get_flow_namespace(parse_state->flow);
+	struct mlx5e_flow_meter_params *params = &attr->meter_attr.params;
 	int err;
 
-	err = fill_meter_params_from_act(act, &attr->meter_attr.params);
+	err = fill_meter_params_from_act(act, params);
 	if (err)
 		return err;
 
-	attr->action |= MLX5_FLOW_CONTEXT_ACTION_EXECUTE_ASO;
-	attr->exe_aso_type = MLX5_EXE_ASO_FLOW_METER;
+	if (params->mtu) {
+		if (!(mlx5_fs_get_capabilities(priv->mdev, ns) &
+		      MLX5_FLOW_STEERING_CAP_MATCH_RANGES))
+			return -EOPNOTSUPP;
+
+		attr->action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
+		attr->flags |= MLX5_ATTR_FLAG_MTU;
+	} else {
+		attr->action |= MLX5_FLOW_CONTEXT_ACTION_EXECUTE_ASO;
+		attr->exe_aso_type = MLX5_EXE_ASO_FLOW_METER;
+	}
 
 	return 0;
 }

drivers/net/ethernet/mellanox/mlx5/core/en/tc/meter.c

@@ -241,7 +241,7 @@ mlx5e_flow_meter_destroy_aso_obj(struct mlx5_core_dev *mdev, u32 obj_id)
 }
 
 static struct mlx5e_flow_meter_handle *
-__mlx5e_flow_meter_alloc(struct mlx5e_flow_meters *flow_meters)
+__mlx5e_flow_meter_alloc(struct mlx5e_flow_meters *flow_meters, bool alloc_aso)
 {
 	struct mlx5_core_dev *mdev = flow_meters->mdev;
 	struct mlx5e_flow_meter_aso_obj *meters_obj;
@@ -268,6 +268,9 @@ __mlx5e_flow_meter_alloc(struct mlx5e_flow_meters *flow_meters)
 	}
 	meter->act_counter = counter;
 
+	if (!alloc_aso)
+		goto no_aso;
+
 	meters_obj = list_first_entry_or_null(&flow_meters->partial_list,
 					      struct mlx5e_flow_meter_aso_obj,
 					      entry);
@@ -300,11 +303,12 @@ __mlx5e_flow_meter_alloc(struct mlx5e_flow_meters *flow_meters)
 	}
 
 	bitmap_set(meters_obj->meters_map, pos, 1);
-	meter->flow_meters = flow_meters;
 	meter->meters_obj = meters_obj;
 	meter->obj_id = meters_obj->base_id + pos / 2;
 	meter->idx = pos % 2;
 
+no_aso:
+	meter->flow_meters = flow_meters;
 	mlx5_core_dbg(mdev, "flow meter allocated, obj_id=0x%x, index=%d\n",
 		      meter->obj_id, meter->idx);
 
@@ -332,6 +336,9 @@ __mlx5e_flow_meter_free(struct mlx5e_flow_meter_handle *meter)
 	mlx5_fc_destroy(mdev, meter->act_counter);
 	mlx5_fc_destroy(mdev, meter->drop_counter);
 
+	if (meter->params.mtu)
+		goto out_no_aso;
+
 	meters_obj = meter->meters_obj;
 	pos = (meter->obj_id - meters_obj->base_id) * 2 + meter->idx;
 	bitmap_clear(meters_obj->meters_map, pos, 1);
@@ -345,6 +352,7 @@ __mlx5e_flow_meter_free(struct mlx5e_flow_meter_handle *meter)
 		list_add(&meters_obj->entry, &flow_meters->partial_list);
 	}
 
+out_no_aso:
 	mlx5_core_dbg(mdev, "flow meter freed, obj_id=0x%x, index=%d\n",
 		      meter->obj_id, meter->idx);
 	kfree(meter);
@@ -409,12 +417,13 @@ mlx5e_tc_meter_alloc(struct mlx5e_flow_meters *flow_meters,
 {
 	struct mlx5e_flow_meter_handle *meter;
 
-	meter = __mlx5e_flow_meter_alloc(flow_meters);
+	meter = __mlx5e_flow_meter_alloc(flow_meters, !params->mtu);
 	if (IS_ERR(meter))
 		return meter;
 
 	hash_add(flow_meters->hashtbl, &meter->hlist, params->index);
 	meter->params.index = params->index;
+	meter->params.mtu = params->mtu;
 	meter->refcnt++;
 
 	return meter;

drivers/net/ethernet/mellanox/mlx5/core/en/tc/meter.h

@@ -20,6 +20,7 @@ struct mlx5e_flow_meter_params {
 	u32 index;
 	u64 rate;
 	u64 burst;
+	u32 mtu;
 };
 
 struct mlx5e_flow_meter_handle {

drivers/net/ethernet/mellanox/mlx5/core/en/tc/post_meter.c

@@ -43,6 +43,18 @@ mlx5e_post_meter_get_ft(struct mlx5e_post_meter_priv *post_meter)
 	return post_meter->rate_steering_table.ft;
 }
 
+struct mlx5_flow_table *
+mlx5e_post_meter_get_mtu_true_ft(struct mlx5e_post_meter_priv *post_meter)
+{
+	return post_meter->mtu_tables.green_table.ft;
+}
+
+struct mlx5_flow_table *
+mlx5e_post_meter_get_mtu_false_ft(struct mlx5e_post_meter_priv *post_meter)
+{
+	return post_meter->mtu_tables.red_table.ft;
+}
+
 static struct mlx5_flow_table *
 mlx5e_post_meter_table_create(struct mlx5e_priv *priv,
 			      enum mlx5_flow_namespace_type ns_type)

drivers/net/ethernet/mellanox/mlx5/core/en/tc/post_meter.h

@@ -19,9 +19,17 @@ enum mlx5e_post_meter_type {
 	MLX5E_POST_METER_MTU
 };
 
+#if IS_ENABLED(CONFIG_MLX5_CLS_ACT)
+
 struct mlx5_flow_table *
 mlx5e_post_meter_get_ft(struct mlx5e_post_meter_priv *post_meter);
 
+struct mlx5_flow_table *
+mlx5e_post_meter_get_mtu_true_ft(struct mlx5e_post_meter_priv *post_meter);
+
+struct mlx5_flow_table *
+mlx5e_post_meter_get_mtu_false_ft(struct mlx5e_post_meter_priv *post_meter);
+
 struct mlx5e_post_meter_priv *
 mlx5e_post_meter_init(struct mlx5e_priv *priv,
 		      enum mlx5_flow_namespace_type ns_type,
@@ -35,4 +43,20 @@ mlx5e_post_meter_init(struct mlx5e_priv *priv,
 void
 mlx5e_post_meter_cleanup(struct mlx5_eswitch *esw, struct mlx5e_post_meter_priv *post_meter);
 
+#else /* CONFIG_MLX5_CLS_ACT */
+
+static inline struct mlx5_flow_table *
+mlx5e_post_meter_get_mtu_true_ft(struct mlx5e_post_meter_priv *post_meter)
+{
+	return NULL;
+}
+
+static inline struct mlx5_flow_table *
+mlx5e_post_meter_get_mtu_false_ft(struct mlx5e_post_meter_priv *post_meter)
+{
+	return NULL;
+}
+
+#endif
+
 #endif /* __MLX5_EN_POST_METER_H__ */

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

@@ -402,8 +402,9 @@ mlx5_tc_rule_delete(struct mlx5e_priv *priv,
 static bool
 is_flow_meter_action(struct mlx5_flow_attr *attr)
 {
-	return ((attr->action & MLX5_FLOW_CONTEXT_ACTION_EXECUTE_ASO) &&
-		(attr->exe_aso_type == MLX5_EXE_ASO_FLOW_METER));
+	return (((attr->action & MLX5_FLOW_CONTEXT_ACTION_EXECUTE_ASO) &&
+		 (attr->exe_aso_type == MLX5_EXE_ASO_FLOW_METER)) ||
+		attr->flags & MLX5_ATTR_FLAG_MTU);
 }
 
 static int
@@ -414,6 +415,7 @@ mlx5e_tc_add_flow_meter(struct mlx5e_priv *priv,
 	struct mlx5e_post_meter_priv *post_meter;
 	enum mlx5_flow_namespace_type ns_type;
 	struct mlx5e_flow_meter_handle *meter;
+	enum mlx5e_post_meter_type type;
 
 	meter = mlx5e_tc_meter_replace(priv->mdev, &attr->meter_attr.params);
 	if (IS_ERR(meter)) {
@@ -422,8 +424,9 @@ mlx5e_tc_add_flow_meter(struct mlx5e_priv *priv,
 	}
 
 	ns_type = mlx5e_tc_meter_get_namespace(meter->flow_meters);
+	type = meter->params.mtu ? MLX5E_POST_METER_MTU : MLX5E_POST_METER_RATE;
 	post_meter = mlx5e_post_meter_init(priv, ns_type, post_act,
-					   MLX5E_POST_METER_RATE,
+					   type,
 					   meter->act_counter, meter->drop_counter,
 					   attr->branch_true, attr->branch_false);
 	if (IS_ERR(post_meter)) {

drivers/net/ethernet/mellanox/mlx5/core/en_tc.h

@@ -114,6 +114,7 @@ enum {
 	MLX5_ATTR_FLAG_ACCEPT        = BIT(5),
 	MLX5_ATTR_FLAG_CT            = BIT(6),
 	MLX5_ATTR_FLAG_TERMINATING   = BIT(7),
+	MLX5_ATTR_FLAG_MTU           = BIT(8),
 };
 
 /* Returns true if any of the flags that require skipping further TC/NF processing are set. */

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

@@ -50,6 +50,7 @@
 #include "en/mapping.h"
 #include "devlink.h"
 #include "lag/lag.h"
+#include "en/tc/post_meter.h"
 
 #define mlx5_esw_for_each_rep(esw, i, rep) \
 	xa_for_each(&((esw)->offloads.vport_reps), i, rep)
@@ -201,6 +202,21 @@ esw_cleanup_decap_indir(struct mlx5_eswitch *esw,
 					 true);
 }
 
+static int
+esw_setup_mtu_dest(struct mlx5_flow_destination *dest,
+		   struct mlx5e_meter_attr *meter,
+		   int i)
+{
+	dest[i].type = MLX5_FLOW_DESTINATION_TYPE_RANGE;
+	dest[i].range.field = MLX5_FLOW_DEST_RANGE_FIELD_PKT_LEN;
+	dest[i].range.min = 0;
+	dest[i].range.max = meter->params.mtu;
+	dest[i].range.hit_ft = mlx5e_post_meter_get_mtu_true_ft(meter->post_meter);
+	dest[i].range.miss_ft = mlx5e_post_meter_get_mtu_false_ft(meter->post_meter);
+
+	return 0;
+}
+
 static int
 esw_setup_sampler_dest(struct mlx5_flow_destination *dest,
 		       struct mlx5_flow_act *flow_act,
@@ -491,6 +507,9 @@ esw_setup_dests(struct mlx5_flow_destination *dest,
 	} else if (attr->flags & MLX5_ATTR_FLAG_ACCEPT) {
 		esw_setup_accept_dest(dest, flow_act, chains, *i);
 		(*i)++;
+	} else if (attr->flags & MLX5_ATTR_FLAG_MTU) {
+		err = esw_setup_mtu_dest(dest, &attr->meter_attr, *i);
+		(*i)++;
 	} else if (esw_is_indir_table(esw, attr)) {
 		err = esw_setup_indir_table(dest, flow_act, esw, attr, spec, true, i);
 	} else if (esw_is_chain_src_port_rewrite(esw, esw_attr)) {