Tue, May 12, 2020 at 05:07:14PM CEST, vadym.kochan@plvision.eu wrote:

On Tue, May 12, 2020 at 05:03:06PM +0200, Jiri Pirko wrote:

quoted

Tue, May 12, 2020 at 04:53:52PM CEST, vadym.kochan@plvision.eu wrote:

quoted

On Mon, May 11, 2020 at 12:32:22PM +0200, Jiri Pirko wrote:

[...]

quoted

This is RCU list. Treat it accordingly.

quoted

+	spin_unlock(&sw->ports_lock);

I don't follow, why do you need to protect the list by spinlock here?
More to that, why do you need the port_list reader-writer
protected (by rcu)? Is is possible that you add/remove port in the same
time packets are flying in?

If yes, you need to ensure the structs are in the memory (free_rcu,
synchronize_rcu). But I believe that you should disable that from
happening in HW.

quoted

+

[...]

quoted

quoted

+
+static int prestera_switch_init(struct prestera_switch *sw)
+{
+	int err;
+
+	err = prestera_hw_switch_init(sw);
+	if (err) {
+		dev_err(prestera_dev(sw), "Failed to init Switch device\n");
+		return err;
+	}
+
+	memcpy(sw->base_mac, base_mac_addr, sizeof(sw->base_mac));
+	spin_lock_init(&sw->ports_lock);
+	INIT_LIST_HEAD(&sw->port_list);
+
+	err = prestera_hw_switch_mac_set(sw, sw->base_mac);
+	if (err)
+		return err;
+
+	err = prestera_rxtx_switch_init(sw);
+	if (err)
+		return err;
+
+	err = prestera_event_handlers_register(sw);
+	if (err)
+		goto err_evt_handlers;
+
+	err = prestera_create_ports(sw);
+	if (err)
+		goto err_ports_create;
+
+	return 0;
+
+err_ports_create:

You are missing prestera_event_handlers_unregister(sw); call here.

it is handled below in prestera_switch_fini().

Sure, but you should call it here in the error path as well. That is my
point.

I understand your point - to make error path more clear, and symmetric ?

Yes.

quoted

quoted

quoted

quoted

+err_evt_handlers:
+	prestera_rxtx_switch_fini(sw);
+
+	return err;
+}
+
+static void prestera_switch_fini(struct prestera_switch *sw)
+{
+	prestera_destroy_ports(sw);
+	prestera_event_handlers_unregister(sw);
+	prestera_rxtx_switch_fini(sw);
+}
+
+int prestera_device_register(struct prestera_device *dev)
+{
+	struct prestera_switch *sw;
+	int err;
+
+	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
+	if (!sw)
+		return -ENOMEM;
+
+	dev->priv = sw;
+	sw->dev = dev;
+
+	err = prestera_switch_init(sw);
+	if (err) {
+		kfree(sw);
+		return err;
+	}
+
+	registered_switch = sw;
+	return 0;
+}
+EXPORT_SYMBOL(prestera_device_register);
+
+void prestera_device_unregister(struct prestera_device *dev)
+{
+	struct prestera_switch *sw = dev->priv;
+
+	registered_switch = NULL;
+	prestera_switch_fini(sw);
+	kfree(sw);
+}
+EXPORT_SYMBOL(prestera_device_unregister);
+
+static int __init prestera_module_init(void)
+{
+	if (!base_mac) {
+		pr_err("[base_mac] parameter must be specified\n");
+		return -EINVAL;
+	}
+	if (!mac_pton(base_mac, base_mac_addr)) {
+		pr_err("[base_mac] parameter has invalid format\n");
+		return -EINVAL;
+	}
+
+	prestera_wq = alloc_workqueue("prestera", 0, 0);
+	if (!prestera_wq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void __exit prestera_module_exit(void)
+{
+	destroy_workqueue(prestera_wq);
+}
+
+module_init(prestera_module_init);
+module_exit(prestera_module_exit);
+
+MODULE_AUTHOR("Marvell Semi.");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Marvell Prestera switch driver");
+
+module_param(base_mac, charp, 0);

No please.


[..]