xref: /openbmc/linux/net/dsa/dsa.c (revision 5cf2c75b5b91bcf81d61b2d2ea1c71363bcacf89) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * net/dsa/dsa.c - Hardware switch handling
4  * Copyright (c) 2008-2009 Marvell Semiconductor
5  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
6  */
7 
8 #include <linux/device.h>
9 #include <linux/list.h>
10 #include <linux/module.h>
11 #include <linux/netdevice.h>
12 #include <linux/sysfs.h>
13 #include <linux/ptp_classify.h>
14 #include <net/dst_metadata.h>
15 
16 #include "dsa_priv.h"
17 
18 static LIST_HEAD(dsa_tag_drivers_list);
19 static DEFINE_MUTEX(dsa_tag_drivers_lock);
20 
21 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
22 				    struct module *owner)
23 {
24 	dsa_tag_driver->owner = owner;
25 
26 	mutex_lock(&dsa_tag_drivers_lock);
27 	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
28 	mutex_unlock(&dsa_tag_drivers_lock);
29 }
30 
31 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
32 			      unsigned int count, struct module *owner)
33 {
34 	unsigned int i;
35 
36 	for (i = 0; i < count; i++)
37 		dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
38 }
39 
40 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
41 {
42 	mutex_lock(&dsa_tag_drivers_lock);
43 	list_del(&dsa_tag_driver->list);
44 	mutex_unlock(&dsa_tag_drivers_lock);
45 }
46 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
47 
48 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
49 				unsigned int count)
50 {
51 	unsigned int i;
52 
53 	for (i = 0; i < count; i++)
54 		dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
55 }
56 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
57 
58 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
59 {
60 	return ops->name;
61 };
62 
63 /* Function takes a reference on the module owning the tagger,
64  * so dsa_tag_driver_put must be called afterwards.
65  */
66 const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name)
67 {
68 	const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
69 	struct dsa_tag_driver *dsa_tag_driver;
70 
71 	request_module("%s%s", DSA_TAG_DRIVER_ALIAS, name);
72 
73 	mutex_lock(&dsa_tag_drivers_lock);
74 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
75 		const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
76 
77 		if (strcmp(name, tmp->name))
78 			continue;
79 
80 		if (!try_module_get(dsa_tag_driver->owner))
81 			break;
82 
83 		ops = tmp;
84 		break;
85 	}
86 	mutex_unlock(&dsa_tag_drivers_lock);
87 
88 	return ops;
89 }
90 
91 const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol)
92 {
93 	struct dsa_tag_driver *dsa_tag_driver;
94 	const struct dsa_device_ops *ops;
95 	bool found = false;
96 
97 	request_module("%sid-%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
98 
99 	mutex_lock(&dsa_tag_drivers_lock);
100 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
101 		ops = dsa_tag_driver->ops;
102 		if (ops->proto == tag_protocol) {
103 			found = true;
104 			break;
105 		}
106 	}
107 
108 	if (found) {
109 		if (!try_module_get(dsa_tag_driver->owner))
110 			ops = ERR_PTR(-ENOPROTOOPT);
111 	} else {
112 		ops = ERR_PTR(-ENOPROTOOPT);
113 	}
114 
115 	mutex_unlock(&dsa_tag_drivers_lock);
116 
117 	return ops;
118 }
119 
120 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
121 {
122 	struct dsa_tag_driver *dsa_tag_driver;
123 
124 	mutex_lock(&dsa_tag_drivers_lock);
125 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
126 		if (dsa_tag_driver->ops == ops) {
127 			module_put(dsa_tag_driver->owner);
128 			break;
129 		}
130 	}
131 	mutex_unlock(&dsa_tag_drivers_lock);
132 }
133 
134 static int dev_is_class(struct device *dev, void *class)
135 {
136 	if (dev->class != NULL && !strcmp(dev->class->name, class))
137 		return 1;
138 
139 	return 0;
140 }
141 
142 static struct device *dev_find_class(struct device *parent, char *class)
143 {
144 	if (dev_is_class(parent, class)) {
145 		get_device(parent);
146 		return parent;
147 	}
148 
149 	return device_find_child(parent, class, dev_is_class);
150 }
151 
152 struct net_device *dsa_dev_to_net_device(struct device *dev)
153 {
154 	struct device *d;
155 
156 	d = dev_find_class(dev, "net");
157 	if (d != NULL) {
158 		struct net_device *nd;
159 
160 		nd = to_net_dev(d);
161 		dev_hold(nd);
162 		put_device(d);
163 
164 		return nd;
165 	}
166 
167 	return NULL;
168 }
169 
170 /* Determine if we should defer delivery of skb until we have a rx timestamp.
171  *
172  * Called from dsa_switch_rcv. For now, this will only work if tagging is
173  * enabled on the switch. Normally the MAC driver would retrieve the hardware
174  * timestamp when it reads the packet out of the hardware. However in a DSA
175  * switch, the DSA driver owning the interface to which the packet is
176  * delivered is never notified unless we do so here.
177  */
178 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
179 				       struct sk_buff *skb)
180 {
181 	struct dsa_switch *ds = p->dp->ds;
182 	unsigned int type;
183 
184 	if (skb_headroom(skb) < ETH_HLEN)
185 		return false;
186 
187 	__skb_push(skb, ETH_HLEN);
188 
189 	type = ptp_classify_raw(skb);
190 
191 	__skb_pull(skb, ETH_HLEN);
192 
193 	if (type == PTP_CLASS_NONE)
194 		return false;
195 
196 	if (likely(ds->ops->port_rxtstamp))
197 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
198 
199 	return false;
200 }
201 
202 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
203 			  struct packet_type *pt, struct net_device *unused)
204 {
205 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
206 	struct dsa_port *cpu_dp = dev->dsa_ptr;
207 	struct sk_buff *nskb = NULL;
208 	struct dsa_slave_priv *p;
209 
210 	if (unlikely(!cpu_dp)) {
211 		kfree_skb(skb);
212 		return 0;
213 	}
214 
215 	skb = skb_unshare(skb, GFP_ATOMIC);
216 	if (!skb)
217 		return 0;
218 
219 	if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
220 		unsigned int port = md_dst->u.port_info.port_id;
221 
222 		skb_dst_drop(skb);
223 		if (!skb_has_extensions(skb))
224 			skb->slow_gro = 0;
225 
226 		skb->dev = dsa_master_find_slave(dev, 0, port);
227 		if (likely(skb->dev)) {
228 			dsa_default_offload_fwd_mark(skb);
229 			nskb = skb;
230 		}
231 	} else {
232 		nskb = cpu_dp->rcv(skb, dev);
233 	}
234 
235 	if (!nskb) {
236 		kfree_skb(skb);
237 		return 0;
238 	}
239 
240 	skb = nskb;
241 	skb_push(skb, ETH_HLEN);
242 	skb->pkt_type = PACKET_HOST;
243 	skb->protocol = eth_type_trans(skb, skb->dev);
244 
245 	if (unlikely(!dsa_slave_dev_check(skb->dev))) {
246 		/* Packet is to be injected directly on an upper
247 		 * device, e.g. a team/bond, so skip all DSA-port
248 		 * specific actions.
249 		 */
250 		netif_rx(skb);
251 		return 0;
252 	}
253 
254 	p = netdev_priv(skb->dev);
255 
256 	if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
257 		nskb = dsa_untag_bridge_pvid(skb);
258 		if (!nskb) {
259 			kfree_skb(skb);
260 			return 0;
261 		}
262 		skb = nskb;
263 	}
264 
265 	dev_sw_netstats_rx_add(skb->dev, skb->len);
266 
267 	if (dsa_skb_defer_rx_timestamp(p, skb))
268 		return 0;
269 
270 	gro_cells_receive(&p->gcells, skb);
271 
272 	return 0;
273 }
274 
275 #ifdef CONFIG_PM_SLEEP
276 static bool dsa_port_is_initialized(const struct dsa_port *dp)
277 {
278 	return dp->type == DSA_PORT_TYPE_USER && dp->slave;
279 }
280 
281 int dsa_switch_suspend(struct dsa_switch *ds)
282 {
283 	struct dsa_port *dp;
284 	int ret = 0;
285 
286 	/* Suspend slave network devices */
287 	dsa_switch_for_each_port(dp, ds) {
288 		if (!dsa_port_is_initialized(dp))
289 			continue;
290 
291 		ret = dsa_slave_suspend(dp->slave);
292 		if (ret)
293 			return ret;
294 	}
295 
296 	if (ds->ops->suspend)
297 		ret = ds->ops->suspend(ds);
298 
299 	return ret;
300 }
301 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
302 
303 int dsa_switch_resume(struct dsa_switch *ds)
304 {
305 	struct dsa_port *dp;
306 	int ret = 0;
307 
308 	if (ds->ops->resume)
309 		ret = ds->ops->resume(ds);
310 
311 	if (ret)
312 		return ret;
313 
314 	/* Resume slave network devices */
315 	dsa_switch_for_each_port(dp, ds) {
316 		if (!dsa_port_is_initialized(dp))
317 			continue;
318 
319 		ret = dsa_slave_resume(dp->slave);
320 		if (ret)
321 			return ret;
322 	}
323 
324 	return 0;
325 }
326 EXPORT_SYMBOL_GPL(dsa_switch_resume);
327 #endif
328 
329 static struct packet_type dsa_pack_type __read_mostly = {
330 	.type	= cpu_to_be16(ETH_P_XDSA),
331 	.func	= dsa_switch_rcv,
332 };
333 
334 static struct workqueue_struct *dsa_owq;
335 
336 bool dsa_schedule_work(struct work_struct *work)
337 {
338 	return queue_work(dsa_owq, work);
339 }
340 
341 void dsa_flush_workqueue(void)
342 {
343 	flush_workqueue(dsa_owq);
344 }
345 EXPORT_SYMBOL_GPL(dsa_flush_workqueue);
346 
347 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
348 {
349 	if (!netdev || !dsa_slave_dev_check(netdev))
350 		return ERR_PTR(-ENODEV);
351 
352 	return dsa_slave_to_port(netdev);
353 }
354 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
355 
356 bool dsa_db_equal(const struct dsa_db *a, const struct dsa_db *b)
357 {
358 	if (a->type != b->type)
359 		return false;
360 
361 	switch (a->type) {
362 	case DSA_DB_PORT:
363 		return a->dp == b->dp;
364 	case DSA_DB_LAG:
365 		return a->lag.dev == b->lag.dev;
366 	case DSA_DB_BRIDGE:
367 		return a->bridge.num == b->bridge.num;
368 	default:
369 		WARN_ON(1);
370 		return false;
371 	}
372 }
373 
374 bool dsa_fdb_present_in_other_db(struct dsa_switch *ds, int port,
375 				 const unsigned char *addr, u16 vid,
376 				 struct dsa_db db)
377 {
378 	struct dsa_port *dp = dsa_to_port(ds, port);
379 	struct dsa_mac_addr *a;
380 
381 	lockdep_assert_held(&dp->addr_lists_lock);
382 
383 	list_for_each_entry(a, &dp->fdbs, list) {
384 		if (!ether_addr_equal(a->addr, addr) || a->vid != vid)
385 			continue;
386 
387 		if (a->db.type == db.type && !dsa_db_equal(&a->db, &db))
388 			return true;
389 	}
390 
391 	return false;
392 }
393 EXPORT_SYMBOL_GPL(dsa_fdb_present_in_other_db);
394 
395 bool dsa_mdb_present_in_other_db(struct dsa_switch *ds, int port,
396 				 const struct switchdev_obj_port_mdb *mdb,
397 				 struct dsa_db db)
398 {
399 	struct dsa_port *dp = dsa_to_port(ds, port);
400 	struct dsa_mac_addr *a;
401 
402 	lockdep_assert_held(&dp->addr_lists_lock);
403 
404 	list_for_each_entry(a, &dp->mdbs, list) {
405 		if (!ether_addr_equal(a->addr, mdb->addr) || a->vid != mdb->vid)
406 			continue;
407 
408 		if (a->db.type == db.type && !dsa_db_equal(&a->db, &db))
409 			return true;
410 	}
411 
412 	return false;
413 }
414 EXPORT_SYMBOL_GPL(dsa_mdb_present_in_other_db);
415 
416 static int __init dsa_init_module(void)
417 {
418 	int rc;
419 
420 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
421 					  WQ_MEM_RECLAIM);
422 	if (!dsa_owq)
423 		return -ENOMEM;
424 
425 	rc = dsa_slave_register_notifier();
426 	if (rc)
427 		goto register_notifier_fail;
428 
429 	dev_add_pack(&dsa_pack_type);
430 
431 	rc = rtnl_link_register(&dsa_link_ops);
432 	if (rc)
433 		goto netlink_register_fail;
434 
435 	return 0;
436 
437 netlink_register_fail:
438 	dsa_slave_unregister_notifier();
439 	dev_remove_pack(&dsa_pack_type);
440 register_notifier_fail:
441 	destroy_workqueue(dsa_owq);
442 
443 	return rc;
444 }
445 module_init(dsa_init_module);
446 
447 static void __exit dsa_cleanup_module(void)
448 {
449 	rtnl_link_unregister(&dsa_link_ops);
450 
451 	dsa_slave_unregister_notifier();
452 	dev_remove_pack(&dsa_pack_type);
453 	destroy_workqueue(dsa_owq);
454 }
455 module_exit(dsa_cleanup_module);
456 
457 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
458 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
459 MODULE_LICENSE("GPL");
460 MODULE_ALIAS("platform:dsa");
461