netdevsim: convert driver to use unlocked devlink API during init/fini

Prepare for devlink reload being called with devlink->lock held and
convert the netdevsim driver to use unlocked devlink API during init and
fini flows. Take devl_lock() in reload_down() and reload_up() ops in the
meantime before reload cmd is converted to take the lock itself.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/netdevsim/bus.c

@@ -72,16 +72,7 @@ new_port_store(struct device *dev, struct device_attribute *attr,
 	if (ret)
 		return ret;
 
-	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
-		return -EBUSY;
-
-	if (nsim_bus_dev->in_reload) {
-		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
-		return -EBUSY;
-	}
-
 	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
-	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 	return ret ? ret : count;
 }
 
@@ -102,16 +93,7 @@ del_port_store(struct device *dev, struct device_attribute *attr,
 	if (ret)
 		return ret;
 
-	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
-		return -EBUSY;
-
-	if (nsim_bus_dev->in_reload) {
-		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
-		return -EBUSY;
-	}
-
 	ret = nsim_drv_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
-	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
 	return ret ? ret : count;
 }
 
@@ -298,7 +280,6 @@ nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queu
 	nsim_bus_dev->num_queues = num_queues;
 	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
 	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
-	mutex_init(&nsim_bus_dev->nsim_bus_reload_lock);
 	/* Disallow using nsim_bus_dev */
 	smp_store_release(&nsim_bus_dev->init, false);
 

drivers/net/netdevsim/fib.c

@@ -1453,7 +1453,7 @@ static void nsim_fib_set_max_all(struct nsim_fib_data *data,
 		int err;
 		u64 val;
 
-		err = devlink_resource_size_get(devlink, res_ids[i], &val);
+		err = devl_resource_size_get(devlink, res_ids[i], &val);
 		if (err)
 			val = (u64) -1;
 		nsim_fib_set_max(data, res_ids[i], val);
@@ -1562,26 +1562,26 @@ struct nsim_fib_data *nsim_fib_create(struct devlink *devlink,
 		goto err_nexthop_nb_unregister;
 	}
 
-	devlink_resource_occ_get_register(devlink,
-					  NSIM_RESOURCE_IPV4_FIB,
-					  nsim_fib_ipv4_resource_occ_get,
-					  data);
-	devlink_resource_occ_get_register(devlink,
-					  NSIM_RESOURCE_IPV4_FIB_RULES,
-					  nsim_fib_ipv4_rules_res_occ_get,
-					  data);
-	devlink_resource_occ_get_register(devlink,
-					  NSIM_RESOURCE_IPV6_FIB,
-					  nsim_fib_ipv6_resource_occ_get,
-					  data);
-	devlink_resource_occ_get_register(devlink,
-					  NSIM_RESOURCE_IPV6_FIB_RULES,
-					  nsim_fib_ipv6_rules_res_occ_get,
-					  data);
-	devlink_resource_occ_get_register(devlink,
-					  NSIM_RESOURCE_NEXTHOPS,
-					  nsim_fib_nexthops_res_occ_get,
-					  data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV4_FIB,
+				       nsim_fib_ipv4_resource_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV4_FIB_RULES,
+				       nsim_fib_ipv4_rules_res_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV6_FIB,
+				       nsim_fib_ipv6_resource_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_IPV6_FIB_RULES,
+				       nsim_fib_ipv6_rules_res_occ_get,
+				       data);
+	devl_resource_occ_get_register(devlink,
+				       NSIM_RESOURCE_NEXTHOPS,
+				       nsim_fib_nexthops_res_occ_get,
+				       data);
 	return data;
 
 err_nexthop_nb_unregister:
@@ -1604,16 +1604,16 @@ struct nsim_fib_data *nsim_fib_create(struct devlink *devlink,
 
 void nsim_fib_destroy(struct devlink *devlink, struct nsim_fib_data *data)
 {
-	devlink_resource_occ_get_unregister(devlink,
-					    NSIM_RESOURCE_NEXTHOPS);
-	devlink_resource_occ_get_unregister(devlink,
-					    NSIM_RESOURCE_IPV6_FIB_RULES);
-	devlink_resource_occ_get_unregister(devlink,
-					    NSIM_RESOURCE_IPV6_FIB);
-	devlink_resource_occ_get_unregister(devlink,
-					    NSIM_RESOURCE_IPV4_FIB_RULES);
-	devlink_resource_occ_get_unregister(devlink,
-					    NSIM_RESOURCE_IPV4_FIB);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_NEXTHOPS);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV6_FIB_RULES);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV6_FIB);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV4_FIB_RULES);
+	devl_resource_occ_get_unregister(devlink,
+					 NSIM_RESOURCE_IPV4_FIB);
 	unregister_fib_notifier(devlink_net(devlink), &data->fib_nb);
 	unregister_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb);
 	flush_work(&data->fib_event_work);

drivers/net/netdevsim/netdevsim.h

@@ -376,9 +376,6 @@ struct nsim_bus_dev {
 				  */
 	unsigned int max_vfs;
 	unsigned int num_vfs;
-	/* Lock for devlink->reload_enabled in netdevsim module */
-	struct mutex nsim_bus_reload_lock;
-	bool in_reload;
 	bool init;
 };
 

include/net/devlink.h

@@ -1517,6 +1517,7 @@ struct device *devlink_to_dev(const struct devlink *devlink);
 
 /* Devlink instance explicit locking */
 void devl_lock(struct devlink *devlink);
+int devl_trylock(struct devlink *devlink);
 void devl_unlock(struct devlink *devlink);
 void devl_assert_locked(struct devlink *devlink);
 bool devl_lock_is_held(struct devlink *devlink);

net/core/devlink.c

@@ -266,6 +266,12 @@ void devl_lock(struct devlink *devlink)
 }
 EXPORT_SYMBOL_GPL(devl_lock);
 
+int devl_trylock(struct devlink *devlink)
+{
+	return mutex_trylock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_trylock);
+
 void devl_unlock(struct devlink *devlink)
 {
 	mutex_unlock(&devlink->lock);