net/mlx5e: Introduce post action infrastructure

Some tc actions are modeled in hardware using multiple tables
causing a tc action list split. For example, CT action is modeled
by jumping to a ct table which is controlled by nf flowtable.
sFlow jumps in hardware to a sample table, which continues to a
"default table" where it should continue processing the action list.

Multi table actions are modeled in hardware using a unique fte_id.
The fte_id is set before jumping to a table. Split actions continue
to a post-action table where the matched fte_id value continues the
execution the tc action list.

Currently the post-action design is implemented only by the ct
action. Introduce post action infrastructure as a pre-step for
reusing it with the sFlow offload feature. Init and destroy the
common post action table. Refactor the ct offload to use the
common post table infrastructure in the next patch.
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-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/Makefile

@@ -44,7 +44,8 @@ mlx5_core-$(CONFIG_MLX5_CLS_ACT)     += en_tc.o en/rep/tc.o en/rep/neigh.o \
 					lib/fs_chains.o en/tc_tun.o \
 					esw/indir_table.o en/tc_tun_encap.o \
 					en/tc_tun_vxlan.o en/tc_tun_gre.o en/tc_tun_geneve.o \
-					en/tc_tun_mplsoudp.o diag/en_tc_tracepoint.o
+					en/tc_tun_mplsoudp.o diag/en_tc_tracepoint.o \
+					en/tc/post_act.o
 mlx5_core-$(CONFIG_MLX5_TC_CT)	     += en/tc_ct.o
 mlx5_core-$(CONFIG_MLX5_TC_SAMPLE)   += en/tc/sample.o
 

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

+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+// Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
+#include "post_act.h"
+#include "mlx5_core.h"
+
+struct mlx5e_post_act {
+	enum mlx5_flow_namespace_type ns_type;
+	struct mlx5_fs_chains *chains;
+	struct mlx5_flow_table *ft;
+	struct mlx5e_priv *priv;
+};
+
+struct mlx5e_post_act *
+mlx5e_tc_post_act_init(struct mlx5e_priv *priv, struct mlx5_fs_chains *chains,
+		       enum mlx5_flow_namespace_type ns_type)
+{
+	struct mlx5e_post_act *post_act;
+	int err;
+
+	if (ns_type == MLX5_FLOW_NAMESPACE_FDB &&
+	    !MLX5_CAP_ESW_FLOWTABLE_FDB(priv->mdev, ignore_flow_level)) {
+		mlx5_core_warn(priv->mdev, "firmware level support is missing\n");
+		err = -EOPNOTSUPP;
+		goto err_check;
+	} else if (!MLX5_CAP_FLOWTABLE_NIC_RX(priv->mdev, ignore_flow_level)) {
+		mlx5_core_warn(priv->mdev, "firmware level support is missing\n");
+		err = -EOPNOTSUPP;
+		goto err_check;
+	}
+
+	post_act = kzalloc(sizeof(*post_act), GFP_KERNEL);
+	if (!post_act) {
+		err = -ENOMEM;
+		goto err_check;
+	}
+	post_act->ft = mlx5_chains_create_global_table(chains);
+	if (IS_ERR(post_act->ft)) {
+		err = PTR_ERR(post_act->ft);
+		mlx5_core_warn(priv->mdev, "failed to create post action table, err: %d\n", err);
+		goto err_ft;
+	}
+	post_act->chains = chains;
+	post_act->ns_type = ns_type;
+	post_act->priv = priv;
+	return post_act;
+
+err_ft:
+	kfree(post_act);
+err_check:
+	return ERR_PTR(err);
+}
+
+void
+mlx5e_tc_post_act_destroy(struct mlx5e_post_act *post_act)
+{
+	if (IS_ERR_OR_NULL(post_act))
+		return;
+
+	mlx5_chains_destroy_global_table(post_act->chains, post_act->ft);
+	kfree(post_act);
+}

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

+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
+
+#ifndef __MLX5_POST_ACTION_H__
+#define __MLX5_POST_ACTION_H__
+
+#include "en.h"
+#include "lib/fs_chains.h"
+
+struct mlx5e_post_act *
+mlx5e_tc_post_act_init(struct mlx5e_priv *priv, struct mlx5_fs_chains *chains,
+		       enum mlx5_flow_namespace_type ns_type);
+
+void
+mlx5e_tc_post_act_destroy(struct mlx5e_post_act *post_act);
+
+#endif /* __MLX5_POST_ACTION_H__ */