devlink: publish params only after driver init is done

Currently, user can do dump or get of param values right after the
devlink params are registered. However the driver may not be initialized
which is an issue. The same problem happens during notification
upon param registration. Allow driver to publish devlink params
whenever it is ready to handle get() ops. Note that this cannot
be resolved by init reordering, as the "driverinit" params have
to be available before the driver is initialized (it needs the param
values there).

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Cc: Michael Chan <michael.chan@broadcom.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c

@@ -258,6 +258,9 @@ int bnxt_dl_register(struct bnxt *bp)
 		netdev_err(bp->dev, "devlink_port_params_register failed");
 		goto err_dl_port_unreg;
 	}
+
+	devlink_params_publish(dl);
+
 	return 0;
 
 err_dl_port_unreg:

drivers/net/ethernet/mellanox/mlx4/main.c

@@ -3981,6 +3981,7 @@ static int mlx4_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (ret)
 		goto err_params_unregister;
 
+	devlink_params_publish(devlink);
 	pci_save_state(pdev);
 	return 0;
 

drivers/net/ethernet/mellanox/mlxsw/core.c

@@ -1062,6 +1062,9 @@ __mlxsw_core_bus_device_register(const struct mlxsw_bus_info *mlxsw_bus_info,
 			goto err_driver_init;
 	}
 
+	if (mlxsw_driver->params_register && !reload)
+		devlink_params_publish(devlink);
+
 	return 0;
 
 err_driver_init:
@@ -1131,6 +1134,8 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core,
 			return;
 	}
 
+	if (mlxsw_core->driver->params_unregister && !reload)
+		devlink_params_unpublish(devlink);
 	if (mlxsw_core->driver->fini)
 		mlxsw_core->driver->fini(mlxsw_core);
 	mlxsw_thermal_fini(mlxsw_core->thermal);

include/net/devlink.h

@@ -358,6 +358,7 @@ struct devlink_param_item {
 	const struct devlink_param *param;
 	union devlink_param_value driverinit_value;
 	bool driverinit_value_valid;
+	bool published;
 };
 
 enum devlink_param_generic_id {
@@ -618,6 +619,8 @@ int devlink_params_register(struct devlink *devlink,
 void devlink_params_unregister(struct devlink *devlink,
 			       const struct devlink_param *params,
 			       size_t params_count);
+void devlink_params_publish(struct devlink *devlink);
+void devlink_params_unpublish(struct devlink *devlink);
 int devlink_port_params_register(struct devlink_port *devlink_port,
 				 const struct devlink_param *params,
 				 size_t params_count);
@@ -724,6 +727,14 @@ static inline void devlink_unregister(struct devlink *devlink)
 {
 }
 
+static inline void devlink_params_publish(struct devlink *devlink)
+{
+}
+
+static inline void devlink_params_unpublish(struct devlink *devlink)
+{
+}
+
 static inline void devlink_free(struct devlink *devlink)
 {
 	kfree(devlink);

net/core/devlink.c

@@ -2858,6 +2858,7 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
 				 u32 portid, u32 seq, int flags)
 {
 	union devlink_param_value param_value[DEVLINK_PARAM_CMODE_MAX + 1];
+	bool param_value_set[DEVLINK_PARAM_CMODE_MAX + 1] = {};
 	const struct devlink_param *param = param_item->param;
 	struct devlink_param_gset_ctx ctx;
 	struct nlattr *param_values_list;
@@ -2876,12 +2877,15 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
 				return -EOPNOTSUPP;
 			param_value[i] = param_item->driverinit_value;
 		} else {
+			if (!param_item->published)
+				continue;
 			ctx.cmode = i;
 			err = devlink_param_get(devlink, param, &ctx);
 			if (err)
 				return err;
 			param_value[i] = ctx.val;
 		}
+		param_value_set[i] = true;
 	}
 
 	hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
@@ -2916,7 +2920,7 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
 		goto param_nest_cancel;
 
 	for (i = 0; i <= DEVLINK_PARAM_CMODE_MAX; i++) {
-		if (!devlink_param_cmode_is_supported(param, i))
+		if (!param_value_set[i])
 			continue;
 		err = devlink_nl_param_value_fill_one(msg, param->type,
 						      i, param_value[i]);
@@ -5886,6 +5890,48 @@ void devlink_params_unregister(struct devlink *devlink,
 }
 EXPORT_SYMBOL_GPL(devlink_params_unregister);
 
+/**
+ *	devlink_params_publish - publish configuration parameters
+ *
+ *	@devlink: devlink
+ *
+ *	Publish previously registered configuration parameters.
+ */
+void devlink_params_publish(struct devlink *devlink)
+{
+	struct devlink_param_item *param_item;
+
+	list_for_each_entry(param_item, &devlink->param_list, list) {
+		if (param_item->published)
+			continue;
+		param_item->published = true;
+		devlink_param_notify(devlink, 0, param_item,
+				     DEVLINK_CMD_PARAM_NEW);
+	}
+}
+EXPORT_SYMBOL_GPL(devlink_params_publish);
+
+/**
+ *	devlink_params_unpublish - unpublish configuration parameters
+ *
+ *	@devlink: devlink
+ *
+ *	Unpublish previously registered configuration parameters.
+ */
+void devlink_params_unpublish(struct devlink *devlink)
+{
+	struct devlink_param_item *param_item;
+
+	list_for_each_entry(param_item, &devlink->param_list, list) {
+		if (!param_item->published)
+			continue;
+		param_item->published = false;
+		devlink_param_notify(devlink, 0, param_item,
+				     DEVLINK_CMD_PARAM_DEL);
+	}
+}
+EXPORT_SYMBOL_GPL(devlink_params_unpublish);
+
 /**
  *	devlink_port_params_register - register port configuration parameters
  *