net/mlx5: DR, Add support for update FTE

Add the support for update FTE, which is needed for cases where there are
multiple rules with the same match. In such case fs_core will merge the
actions and call update FTE to update current FTE. Since we don't want to
disrupt the traffic, we will add the new duplicate rule, and only then
remove the old duplicate rule.
Signed-off-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -625,15 +625,6 @@ static void mlx5_cmd_dr_modify_header_dealloc(struct mlx5_flow_root_namespace *n
 	mlx5dr_action_destroy(modify_hdr->action.dr_action);
 }
 
-static int mlx5_cmd_dr_update_fte(struct mlx5_flow_root_namespace *ns,
-				  struct mlx5_flow_table *ft,
-				  struct mlx5_flow_group *group,
-				  int modify_mask,
-				  struct fs_fte *fte)
-{
-	return -EOPNOTSUPP;
-}
-
 static int mlx5_cmd_dr_delete_fte(struct mlx5_flow_root_namespace *ns,
 				  struct mlx5_flow_table *ft,
 				  struct fs_fte *fte)
@@ -658,6 +649,36 @@ static int mlx5_cmd_dr_delete_fte(struct mlx5_flow_root_namespace *ns,
 	return 0;
 }
 
+static int mlx5_cmd_dr_update_fte(struct mlx5_flow_root_namespace *ns,
+				  struct mlx5_flow_table *ft,
+				  struct mlx5_flow_group *group,
+				  int modify_mask,
+				  struct fs_fte *fte)
+{
+	struct fs_fte fte_tmp = {};
+	int ret;
+
+	if (mlx5_dr_is_fw_table(ft->flags))
+		return mlx5_fs_cmd_get_fw_cmds()->update_fte(ns, ft, group, modify_mask, fte);
+
+	/* Backup current dr rule details */
+	fte_tmp.fs_dr_rule = fte->fs_dr_rule;
+	memset(&fte->fs_dr_rule, 0, sizeof(struct mlx5_fs_dr_rule));
+
+	/* First add the new updated rule, then delete the old rule */
+	ret = mlx5_cmd_dr_create_fte(ns, ft, group, fte);
+	if (ret)
+		goto restore_fte;
+
+	ret = mlx5_cmd_dr_delete_fte(ns, ft, &fte_tmp);
+	WARN_ONCE(ret, "dr update fte duplicate rule deletion failed\n");
+	return ret;
+
+restore_fte:
+	fte->fs_dr_rule = fte_tmp.fs_dr_rule;
+	return ret;
+}
+
 static int mlx5_cmd_dr_set_peer(struct mlx5_flow_root_namespace *ns,
 				struct mlx5_flow_root_namespace *peer_ns)
 {