netdevsim: Change nsim_devlink_setup to return error to caller

Change nsim_devlink_setup to return any error back to the caller and
update nsim_init to handle it.

Requested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netdevsim/devlink.c

@@ -218,22 +218,22 @@ void nsim_devlink_teardown(struct netdevsim *ns)
 	}
 }
 
-void nsim_devlink_setup(struct netdevsim *ns)
+int nsim_devlink_setup(struct netdevsim *ns)
 {
 	struct net *net = nsim_to_net(ns);
 	bool *reg_devlink = net_generic(net, nsim_devlink_id);
 	struct devlink *devlink;
-	int err = -ENOMEM;
+	int err;
 
 	/* only one device per namespace controls devlink */
 	if (!*reg_devlink) {
 		ns->devlink = NULL;
-		return;
+		return 0;
 	}
 
 	devlink = devlink_alloc(&nsim_devlink_ops, 0);
 	if (!devlink)
-		return;
+		return -ENOMEM;
 
 	err = devlink_register(devlink, &ns->dev);
 	if (err)
@@ -247,12 +247,14 @@ void nsim_devlink_setup(struct netdevsim *ns)
 
 	*reg_devlink = false;
 
-	return;
+	return 0;
 
 err_dl_unregister:
 	devlink_unregister(devlink);
 err_devlink_free:
 	devlink_free(devlink);
+
+	return err;
 }
 
 /* Initialize per network namespace state */

drivers/net/netdevsim/netdev.c

@@ -167,10 +167,14 @@ static int nsim_init(struct net_device *dev)
 
 	SET_NETDEV_DEV(dev, &ns->dev);
 
-	nsim_devlink_setup(ns);
+	err = nsim_devlink_setup(ns);
+	if (err)
+		goto err_unreg_dev;
 
 	return 0;
 
+err_unreg_dev:
+	device_unregister(&ns->dev);
 err_bpf_uninit:
 	nsim_bpf_uninit(ns);
 err_debugfs_destroy:

drivers/net/netdevsim/netdevsim.h

@@ -117,7 +117,7 @@ enum nsim_resource_id {
 	NSIM_RESOURCE_IPV6_FIB_RULES,
 };
 
-void nsim_devlink_setup(struct netdevsim *ns);
+int nsim_devlink_setup(struct netdevsim *ns);
 void nsim_devlink_teardown(struct netdevsim *ns);
 
 int nsim_devlink_init(void);
@@ -128,8 +128,9 @@ void nsim_fib_exit(void);
 u64 nsim_fib_get_val(struct net *net, enum nsim_resource_id res_id, bool max);
 int nsim_fib_set_max(struct net *net, enum nsim_resource_id res_id, u64 val);
 #else
-static inline void nsim_devlink_setup(struct netdevsim *ns)
+static inline int nsim_devlink_setup(struct netdevsim *ns)
 {
+	return 0;
 }
 
 static inline void nsim_devlink_teardown(struct netdevsim *ns)