net: devlink: convert reload command to take implicit devlink->lock

Convert reload command to behave the same way as the rest of the
commands and let if be called with devlink->lock held. Remove the
temporary devl_lock taking from drivers. As the DEVLINK_NL_FLAG_NO_LOCK
flag is no longer used, remove it alongside.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -3958,11 +3958,9 @@ static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
 		NL_SET_ERR_MSG_MOD(extack, "Namespace change is not supported");
 		return -EOPNOTSUPP;
 	}
-	devl_lock(devlink);
 	if (persist->num_vfs)
 		mlx4_warn(persist->dev, "Reload performed on PF, will cause reset on operating Virtual Functions\n");
 	mlx4_restart_one_down(persist->pdev);
-	devl_unlock(devlink);
 	return 0;
 }
 
@@ -3975,10 +3973,8 @@ static int mlx4_devlink_reload_up(struct devlink *devlink, enum devlink_reload_a
 	struct mlx4_dev_persistent *persist = dev->persist;
 	int err;
 
-	devl_lock(devlink);
 	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
 	err = mlx4_restart_one_up(persist->pdev, true, devlink);
-	devl_unlock(devlink);
 	if (err)
 		mlx4_err(persist->dev, "mlx4_restart_one_up failed, ret=%d\n",
 			 err);

drivers/net/ethernet/mellanox/mlx5/core/devlink.c

@@ -164,7 +164,6 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 		NL_SET_ERR_MSG_MOD(extack, "reload while VFs are present is unfavorable");
 	}
 
-	devl_lock(devlink);
 	switch (action) {
 	case DEVLINK_RELOAD_ACTION_DRIVER_REINIT:
 		mlx5_unload_one_devl_locked(dev);
@@ -181,7 +180,6 @@ static int mlx5_devlink_reload_down(struct devlink *devlink, bool netns_change,
 		ret = -EOPNOTSUPP;
 	}
 
-	devl_unlock(devlink);
 	return ret;
 }
 
@@ -192,7 +190,6 @@ static int mlx5_devlink_reload_up(struct devlink *devlink, enum devlink_reload_a
 	struct mlx5_core_dev *dev = devlink_priv(devlink);
 	int ret = 0;
 
-	devl_lock(devlink);
 	*actions_performed = BIT(action);
 	switch (action) {
 	case DEVLINK_RELOAD_ACTION_DRIVER_REINIT:
@@ -211,7 +208,6 @@ static int mlx5_devlink_reload_up(struct devlink *devlink, enum devlink_reload_a
 		ret = -EOPNOTSUPP;
 	}
 
-	devl_unlock(devlink);
 	return ret;
 }
 

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

@@ -1499,9 +1499,7 @@ mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
 	if (!(mlxsw_core->bus->features & MLXSW_BUS_F_RESET))
 		return -EOPNOTSUPP;
 
-	devl_lock(devlink);
 	mlxsw_core_bus_device_unregister(mlxsw_core, true);
-	devl_unlock(devlink);
 	return 0;
 }
 
@@ -1515,12 +1513,10 @@ mlxsw_devlink_core_bus_device_reload_up(struct devlink *devlink, enum devlink_re
 
 	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
 			     BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
-	devl_lock(devlink);
 	err = mlxsw_core_bus_device_register(mlxsw_core->bus_info,
 					     mlxsw_core->bus,
 					     mlxsw_core->bus_priv, true,
 					     devlink, extack);
-	devl_unlock(devlink);
 	return err;
 }
 

drivers/net/netdevsim/dev.c

@@ -948,18 +948,15 @@ static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
 {
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 
-	devl_lock(devlink);
 	if (nsim_dev->dont_allow_reload) {
 		/* For testing purposes, user set debugfs dont_allow_reload
 		 * value to true. So forbid it.
 		 */
 		NL_SET_ERR_MSG_MOD(extack, "User forbid the reload for testing purposes");
-		devl_unlock(devlink);
 		return -EOPNOTSUPP;
 	}
 
 	nsim_dev_reload_destroy(nsim_dev);
-	devl_unlock(devlink);
 	return 0;
 }
 
@@ -970,19 +967,16 @@ static int nsim_dev_reload_up(struct devlink *devlink, enum devlink_reload_actio
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 	int ret;
 
-	devl_lock(devlink);
 	if (nsim_dev->fail_reload) {
 		/* For testing purposes, user set debugfs fail_reload
 		 * value to true. Fail right away.
 		 */
 		NL_SET_ERR_MSG_MOD(extack, "User setup the reload to fail for testing purposes");
-		devl_unlock(devlink);
 		return -EINVAL;
 	}
 
 	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
 	ret = nsim_dev_reload_create(nsim_dev, extack);
-	devl_unlock(devlink);
 	return ret;
 }
 

net/core/devlink.c

@@ -768,12 +768,6 @@ devlink_region_snapshot_get_by_id(struct devlink_region *region, u32 id)
 #define DEVLINK_NL_FLAG_NEED_RATE_NODE		BIT(3)
 #define DEVLINK_NL_FLAG_NEED_LINECARD		BIT(4)
 
-/* The per devlink instance lock is taken by default in the pre-doit
- * operation, yet several commands do not require this. The global
- * devlink lock is taken and protects from disruption by user-calls.
- */
-#define DEVLINK_NL_FLAG_NO_LOCK			BIT(5)
-
 static int devlink_nl_pre_doit(const struct genl_ops *ops,
 			       struct sk_buff *skb, struct genl_info *info)
 {
@@ -788,7 +782,6 @@ static int devlink_nl_pre_doit(const struct genl_ops *ops,
 		mutex_unlock(&devlink_mutex);
 		return PTR_ERR(devlink);
 	}
-	if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
 	devl_lock(devlink);
 	info->user_ptr[0] = devlink;
 	if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_PORT) {
@@ -831,7 +824,6 @@ static int devlink_nl_pre_doit(const struct genl_ops *ops,
 	return 0;
 
 unlock:
-	if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
 	devl_unlock(devlink);
 	devlink_put(devlink);
 	mutex_unlock(&devlink_mutex);
@@ -849,7 +841,6 @@ static void devlink_nl_post_doit(const struct genl_ops *ops,
 		linecard = info->user_ptr[1];
 		devlink_linecard_put(linecard);
 	}
-	if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
 	devl_unlock(devlink);
 	devlink_put(devlink);
 	mutex_unlock(&devlink_mutex);
@@ -9414,7 +9405,6 @@ static const struct genl_small_ops devlink_nl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_reload,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
 		.cmd = DEVLINK_CMD_PARAM_GET,
@@ -12507,10 +12497,12 @@ static void __net_exit devlink_pernet_pre_exit(struct net *net)
 	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(net, index, devlink) {
 		WARN_ON(!(devlink->features & DEVLINK_F_RELOAD));
+		mutex_lock(&devlink->lock);
 		err = devlink_reload(devlink, &init_net,
 				     DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
 				     DEVLINK_RELOAD_LIMIT_UNSPEC,
 				     &actions_performed, NULL);
+		mutex_unlock(&devlink->lock);
 		if (err && err != -EOPNOTSUPP)
 			pr_warn("Failed to reload devlink instance into init_net\n");
 		devlink_put(devlink);