net/mlx5e: Add post meter table for flow metering

Flow meter object monitors the packets rate for the flows it is
attached to, and color packets with GREEN or RED. The post meter table
is used to check the color. Packet is dropped if it's RED, or
forwarded to post_act table if GREEN.

Packet color will be set to 8 LSB of the register C5, so they are
reserved for metering, which are previously used for matching fte id.

Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Ariel Levkovich <lariel@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

1 files changed, 198 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc/post_meter.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc/post_meter.c
new file mode 100644
index 000000000000..efa20356764e
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc/post_meter.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+// Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
+#include "en/tc_priv.h"
+#include "post_meter.h"
+#include "en/tc/post_act.h"
+
+#define MLX5_PACKET_COLOR_BITS MLX5_REG_MAPPING_MBITS(PACKET_COLOR_TO_REG)
+#define MLX5_PACKET_COLOR_MASK MLX5_REG_MAPPING_MASK(PACKET_COLOR_TO_REG)
+
+struct mlx5e_post_meter_priv {
+	struct mlx5_flow_table *ft;
+	struct mlx5_flow_group *fg;
+	struct mlx5_flow_handle *fwd_green_rule;
+	struct mlx5_flow_handle *drop_red_rule;
+};
+
+struct mlx5_flow_table *
+mlx5e_post_meter_get_ft(struct mlx5e_post_meter_priv *post_meter)
+{
+	return post_meter->ft;
+}
+
+static int
+mlx5e_post_meter_table_create(struct mlx5e_priv *priv,
+			      enum mlx5_flow_namespace_type ns_type,
+			      struct mlx5e_post_meter_priv *post_meter)
+{
+	struct mlx5_flow_table_attr ft_attr = {};
+	struct mlx5_flow_namespace *root_ns;
+
+	root_ns = mlx5_get_flow_namespace(priv->mdev, ns_type);
+	if (!root_ns) {
+		mlx5_core_warn(priv->mdev, "Failed to get namespace for flow meter\n");
+		return -EOPNOTSUPP;
+	}
+
+	ft_attr.flags = MLX5_FLOW_TABLE_UNMANAGED;
+	ft_attr.prio = FDB_SLOW_PATH;
+	ft_attr.max_fte = 2;
+	ft_attr.level = 1;
+
+	post_meter->ft = mlx5_create_flow_table(root_ns, &ft_attr);
+	if (IS_ERR(post_meter->ft)) {
+		mlx5_core_warn(priv->mdev, "Failed to create post_meter table\n");
+		return PTR_ERR(post_meter->ft);
+	}
+
+	return 0;
+}
+
+static int
+mlx5e_post_meter_fg_create(struct mlx5e_priv *priv,
+			   struct mlx5e_post_meter_priv *post_meter)
+{
+	int inlen = MLX5_ST_SZ_BYTES(create_flow_group_in);
+	void *misc2, *match_criteria;
+	u32 *flow_group_in;
+	int err = 0;
+
+	flow_group_in = kvzalloc(inlen, GFP_KERNEL);
+	if (!flow_group_in)
+		return -ENOMEM;
+
+	MLX5_SET(create_flow_group_in, flow_group_in, match_criteria_enable,
+		 MLX5_MATCH_MISC_PARAMETERS_2);
+	match_criteria = MLX5_ADDR_OF(create_flow_group_in, flow_group_in,
+				      match_criteria);
+	misc2 = MLX5_ADDR_OF(fte_match_param, match_criteria, misc_parameters_2);
+	MLX5_SET(fte_match_set_misc2, misc2, metadata_reg_c_5, MLX5_PACKET_COLOR_MASK);
+	MLX5_SET(create_flow_group_in, flow_group_in, start_flow_index, 0);
+	MLX5_SET(create_flow_group_in, flow_group_in, end_flow_index, 1);
+
+	post_meter->fg = mlx5_create_flow_group(post_meter->ft, flow_group_in);
+	if (IS_ERR(post_meter->fg)) {
+		mlx5_core_warn(priv->mdev, "Failed to create post_meter flow group\n");
+		err = PTR_ERR(post_meter->fg);
+	}
+
+	kvfree(flow_group_in);
+	return err;
+}
+
+static int
+mlx5e_post_meter_rules_create(struct mlx5e_priv *priv,
+			      struct mlx5e_post_meter_priv *post_meter,
+			      struct mlx5e_post_act *post_act)
+{
+	struct mlx5_flow_destination dest = {};
+	struct mlx5_flow_act flow_act = {};
+	struct mlx5_flow_handle *rule;
+	struct mlx5_flow_spec *spec;
+	int err;
+
+	spec = kvzalloc(sizeof(*spec), GFP_KERNEL);
+	if (!spec)
+		return -ENOMEM;
+
+	mlx5e_tc_match_to_reg_match(spec, PACKET_COLOR_TO_REG,
+				    MLX5_FLOW_METER_COLOR_RED, MLX5_PACKET_COLOR_MASK);
+	flow_act.action = MLX5_FLOW_CONTEXT_ACTION_DROP;
+	flow_act.flags |= FLOW_ACT_IGNORE_FLOW_LEVEL;
+
+	rule = mlx5_add_flow_rules(post_meter->ft, spec, &flow_act, NULL, 0);
+	if (IS_ERR(rule)) {
+		mlx5_core_warn(priv->mdev, "Failed to create post_meter flow drop rule\n");
+		err = PTR_ERR(rule);
+		goto err_red;
+	}
+	post_meter->drop_red_rule = rule;
+
+	mlx5e_tc_match_to_reg_match(spec, PACKET_COLOR_TO_REG,
+				    MLX5_FLOW_METER_COLOR_GREEN, MLX5_PACKET_COLOR_MASK);
+	flow_act.action = MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
+	dest.type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE;
+	dest.ft = mlx5e_tc_post_act_get_ft(post_act);
+
+	rule = mlx5_add_flow_rules(post_meter->ft, spec, &flow_act, &dest, 1);
+	if (IS_ERR(rule)) {
+		mlx5_core_warn(priv->mdev, "Failed to create post_meter flow fwd rule\n");
+		err = PTR_ERR(rule);
+		goto err_green;
+	}
+	post_meter->fwd_green_rule = rule;
+
+	kvfree(spec);
+	return 0;
+
+err_green:
+	mlx5_del_flow_rules(post_meter->drop_red_rule);
+err_red:
+	kvfree(spec);
+	return err;
+}
+
+static void
+mlx5e_post_meter_rules_destroy(struct mlx5e_post_meter_priv *post_meter)
+{
+	mlx5_del_flow_rules(post_meter->drop_red_rule);
+	mlx5_del_flow_rules(post_meter->fwd_green_rule);
+}
+
+static void
+mlx5e_post_meter_fg_destroy(struct mlx5e_post_meter_priv *post_meter)
+{
+	mlx5_destroy_flow_group(post_meter->fg);
+}
+
+static void
+mlx5e_post_meter_table_destroy(struct mlx5e_post_meter_priv *post_meter)
+{
+	mlx5_destroy_flow_table(post_meter->ft);
+}
+
+struct mlx5e_post_meter_priv *
+mlx5e_post_meter_init(struct mlx5e_priv *priv,
+		      enum mlx5_flow_namespace_type ns_type,
+		      struct mlx5e_post_act *post_act)
+{
+	struct mlx5e_post_meter_priv *post_meter;
+	int err;
+
+	post_meter = kzalloc(sizeof(*post_meter), GFP_KERNEL);
+	if (!post_meter)
+		return ERR_PTR(-ENOMEM);
+
+	err = mlx5e_post_meter_table_create(priv, ns_type, post_meter);
+	if (err)
+		goto err_ft;
+
+	err = mlx5e_post_meter_fg_create(priv, post_meter);
+	if (err)
+		goto err_fg;
+
+	err = mlx5e_post_meter_rules_create(priv, post_meter, post_act);
+	if (err)
+		goto err_rules;
+
+	return post_meter;
+
+err_rules:
+	mlx5e_post_meter_fg_destroy(post_meter);
+err_fg:
+	mlx5e_post_meter_table_destroy(post_meter);
+err_ft:
+	kfree(post_meter);
+	return ERR_PTR(err);
+}
+
+void
+mlx5e_post_meter_cleanup(struct mlx5e_post_meter_priv *post_meter)
+{
+	mlx5e_post_meter_rules_destroy(post_meter);
+	mlx5e_post_meter_fg_destroy(post_meter);
+	mlx5e_post_meter_table_destroy(post_meter);
+	kfree(post_meter);
+}
+