net/mlx5: DR, Add required FW steering functionality

SW steering is capable of doing many steering functionalities
but there are still some functionalities which are not exposed
to upper layers and therefore performed by the FW.

This is the support for recalculating checksum using a hairpin QP.
The recalculation is required after a modify TTL action which skips
the needed CS calculation in HW.
Signed-off-by: Alex Vesker <valex@mellanox.com>
Reviewed-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_fw.c

+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2019 Mellanox Technologies. */
+
+#include <linux/types.h>
+#include "dr_types.h"
+
+struct mlx5dr_fw_recalc_cs_ft *
+mlx5dr_fw_create_recalc_cs_ft(struct mlx5dr_domain *dmn, u32 vport_num)
+{
+	struct mlx5dr_fw_recalc_cs_ft *recalc_cs_ft;
+	u32 table_id, group_id, modify_hdr_id;
+	u64 rx_icm_addr, modify_ttl_action;
+	int ret;
+
+	recalc_cs_ft = kzalloc(sizeof(*recalc_cs_ft), GFP_KERNEL);
+	if (!recalc_cs_ft)
+		return NULL;
+
+	ret = mlx5dr_cmd_create_flow_table(dmn->mdev, MLX5_FLOW_TABLE_TYPE_FDB,
+					   0, 0, dmn->info.caps.max_ft_level - 1,
+					   false, true, &rx_icm_addr, &table_id);
+	if (ret) {
+		mlx5dr_err(dmn, "Failed creating TTL W/A FW flow table %d\n", ret);
+		goto free_ttl_tbl;
+	}
+
+	ret = mlx5dr_cmd_create_empty_flow_group(dmn->mdev,
+						 MLX5_FLOW_TABLE_TYPE_FDB,
+						 table_id, &group_id);
+	if (ret) {
+		mlx5dr_err(dmn, "Failed creating TTL W/A FW flow group %d\n", ret);
+		goto destroy_flow_table;
+	}
+
+	/* Modify TTL action by adding zero to trigger CS recalculation */
+	modify_ttl_action = 0;
+	MLX5_SET(set_action_in, &modify_ttl_action, action_type, MLX5_ACTION_TYPE_ADD);
+	MLX5_SET(set_action_in, &modify_ttl_action, field, MLX5_ACTION_IN_FIELD_OUT_IP_TTL);
+
+	ret = mlx5dr_cmd_alloc_modify_header(dmn->mdev, MLX5_FLOW_TABLE_TYPE_FDB, 1,
+					     &modify_ttl_action,
+					     &modify_hdr_id);
+	if (ret) {
+		mlx5dr_err(dmn, "Failed modify header TTL %d\n", ret);
+		goto destroy_flow_group;
+	}
+
+	ret = mlx5dr_cmd_set_fte_modify_and_vport(dmn->mdev,
+						  MLX5_FLOW_TABLE_TYPE_FDB,
+						  table_id, group_id, modify_hdr_id,
+						  vport_num);
+	if (ret) {
+		mlx5dr_err(dmn, "Failed setting TTL W/A flow table entry %d\n", ret);
+		goto dealloc_modify_header;
+	}
+
+	recalc_cs_ft->modify_hdr_id = modify_hdr_id;
+	recalc_cs_ft->rx_icm_addr = rx_icm_addr;
+	recalc_cs_ft->table_id = table_id;
+	recalc_cs_ft->group_id = group_id;
+
+	return recalc_cs_ft;
+
+dealloc_modify_header:
+	mlx5dr_cmd_dealloc_modify_header(dmn->mdev, modify_hdr_id);
+destroy_flow_group:
+	mlx5dr_cmd_destroy_flow_group(dmn->mdev,
+				      MLX5_FLOW_TABLE_TYPE_FDB,
+				      table_id, group_id);
+destroy_flow_table:
+	mlx5dr_cmd_destroy_flow_table(dmn->mdev, table_id, MLX5_FLOW_TABLE_TYPE_FDB);
+free_ttl_tbl:
+	kfree(recalc_cs_ft);
+	return NULL;
+}
+
+void mlx5dr_fw_destroy_recalc_cs_ft(struct mlx5dr_domain *dmn,
+				    struct mlx5dr_fw_recalc_cs_ft *recalc_cs_ft)
+{
+	mlx5dr_cmd_del_flow_table_entry(dmn->mdev,
+					MLX5_FLOW_TABLE_TYPE_FDB,
+					recalc_cs_ft->table_id);
+	mlx5dr_cmd_dealloc_modify_header(dmn->mdev, recalc_cs_ft->modify_hdr_id);
+	mlx5dr_cmd_destroy_flow_group(dmn->mdev,
+				      MLX5_FLOW_TABLE_TYPE_FDB,
+				      recalc_cs_ft->table_id,
+				      recalc_cs_ft->group_id);
+	mlx5dr_cmd_destroy_flow_table(dmn->mdev,
+				      recalc_cs_ft->table_id,
+				      MLX5_FLOW_TABLE_TYPE_FDB);
+
+	kfree(recalc_cs_ft);
+}