xref: /openbmc/linux/net/dsa/dsa.c (revision 64a9f19a) 
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 
15 #include "dsa_priv.h"
16 
17 static LIST_HEAD(dsa_tag_drivers_list);
18 static DEFINE_MUTEX(dsa_tag_drivers_lock);
19 
20 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
21 					    struct net_device *dev)
22 {
23 	/* Just return the original SKB */
24 	return skb;
25 }
26 
27 static const struct dsa_device_ops none_ops = {
28 	.name	= "none",
29 	.proto	= DSA_TAG_PROTO_NONE,
30 	.xmit	= dsa_slave_notag_xmit,
31 	.rcv	= NULL,
32 };
33 
34 DSA_TAG_DRIVER(none_ops);
35 
36 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
37 				    struct module *owner)
38 {
39 	dsa_tag_driver->owner = owner;
40 
41 	mutex_lock(&dsa_tag_drivers_lock);
42 	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
43 	mutex_unlock(&dsa_tag_drivers_lock);
44 }
45 
46 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
47 			      unsigned int count, struct module *owner)
48 {
49 	unsigned int i;
50 
51 	for (i = 0; i < count; i++)
52 		dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
53 }
54 
55 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
56 {
57 	mutex_lock(&dsa_tag_drivers_lock);
58 	list_del(&dsa_tag_driver->list);
59 	mutex_unlock(&dsa_tag_drivers_lock);
60 }
61 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
62 
63 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
64 				unsigned int count)
65 {
66 	unsigned int i;
67 
68 	for (i = 0; i < count; i++)
69 		dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
70 }
71 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
72 
73 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
74 {
75 	return ops->name;
76 };
77 
78 /* Function takes a reference on the module owning the tagger,
79  * so dsa_tag_driver_put must be called afterwards.
80  */
81 const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf)
82 {
83 	const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
84 	struct dsa_tag_driver *dsa_tag_driver;
85 
86 	mutex_lock(&dsa_tag_drivers_lock);
87 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
88 		const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
89 
90 		if (!sysfs_streq(buf, tmp->name))
91 			continue;
92 
93 		if (!try_module_get(dsa_tag_driver->owner))
94 			break;
95 
96 		ops = tmp;
97 		break;
98 	}
99 	mutex_unlock(&dsa_tag_drivers_lock);
100 
101 	return ops;
102 }
103 
104 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
105 {
106 	struct dsa_tag_driver *dsa_tag_driver;
107 	const struct dsa_device_ops *ops;
108 	bool found = false;
109 
110 	request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
111 
112 	mutex_lock(&dsa_tag_drivers_lock);
113 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
114 		ops = dsa_tag_driver->ops;
115 		if (ops->proto == tag_protocol) {
116 			found = true;
117 			break;
118 		}
119 	}
120 
121 	if (found) {
122 		if (!try_module_get(dsa_tag_driver->owner))
123 			ops = ERR_PTR(-ENOPROTOOPT);
124 	} else {
125 		ops = ERR_PTR(-ENOPROTOOPT);
126 	}
127 
128 	mutex_unlock(&dsa_tag_drivers_lock);
129 
130 	return ops;
131 }
132 
133 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
134 {
135 	struct dsa_tag_driver *dsa_tag_driver;
136 
137 	mutex_lock(&dsa_tag_drivers_lock);
138 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
139 		if (dsa_tag_driver->ops == ops) {
140 			module_put(dsa_tag_driver->owner);
141 			break;
142 		}
143 	}
144 	mutex_unlock(&dsa_tag_drivers_lock);
145 }
146 
147 static int dev_is_class(struct device *dev, void *class)
148 {
149 	if (dev->class != NULL && !strcmp(dev->class->name, class))
150 		return 1;
151 
152 	return 0;
153 }
154 
155 static struct device *dev_find_class(struct device *parent, char *class)
156 {
157 	if (dev_is_class(parent, class)) {
158 		get_device(parent);
159 		return parent;
160 	}
161 
162 	return device_find_child(parent, class, dev_is_class);
163 }
164 
165 struct net_device *dsa_dev_to_net_device(struct device *dev)
166 {
167 	struct device *d;
168 
169 	d = dev_find_class(dev, "net");
170 	if (d != NULL) {
171 		struct net_device *nd;
172 
173 		nd = to_net_dev(d);
174 		dev_hold(nd);
175 		put_device(d);
176 
177 		return nd;
178 	}
179 
180 	return NULL;
181 }
182 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
183 
184 /* Determine if we should defer delivery of skb until we have a rx timestamp.
185  *
186  * Called from dsa_switch_rcv. For now, this will only work if tagging is
187  * enabled on the switch. Normally the MAC driver would retrieve the hardware
188  * timestamp when it reads the packet out of the hardware. However in a DSA
189  * switch, the DSA driver owning the interface to which the packet is
190  * delivered is never notified unless we do so here.
191  */
192 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
193 				       struct sk_buff *skb)
194 {
195 	struct dsa_switch *ds = p->dp->ds;
196 	unsigned int type;
197 
198 	if (skb_headroom(skb) < ETH_HLEN)
199 		return false;
200 
201 	__skb_push(skb, ETH_HLEN);
202 
203 	type = ptp_classify_raw(skb);
204 
205 	__skb_pull(skb, ETH_HLEN);
206 
207 	if (type == PTP_CLASS_NONE)
208 		return false;
209 
210 	if (likely(ds->ops->port_rxtstamp))
211 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
212 
213 	return false;
214 }
215 
216 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
217 			  struct packet_type *pt, struct net_device *unused)
218 {
219 	struct dsa_port *cpu_dp = dev->dsa_ptr;
220 	struct sk_buff *nskb = NULL;
221 	struct dsa_slave_priv *p;
222 
223 	if (unlikely(!cpu_dp)) {
224 		kfree_skb(skb);
225 		return 0;
226 	}
227 
228 	skb = skb_unshare(skb, GFP_ATOMIC);
229 	if (!skb)
230 		return 0;
231 
232 	nskb = cpu_dp->rcv(skb, dev);
233 	if (!nskb) {
234 		kfree_skb(skb);
235 		return 0;
236 	}
237 
238 	skb = nskb;
239 	skb_push(skb, ETH_HLEN);
240 	skb->pkt_type = PACKET_HOST;
241 	skb->protocol = eth_type_trans(skb, skb->dev);
242 
243 	if (unlikely(!dsa_slave_dev_check(skb->dev))) {
244 		/* Packet is to be injected directly on an upper
245 		 * device, e.g. a team/bond, so skip all DSA-port
246 		 * specific actions.
247 		 */
248 		netif_rx(skb);
249 		return 0;
250 	}
251 
252 	p = netdev_priv(skb->dev);
253 
254 	if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
255 		nskb = dsa_untag_bridge_pvid(skb);
256 		if (!nskb) {
257 			kfree_skb(skb);
258 			return 0;
259 		}
260 		skb = nskb;
261 	}
262 
263 	dev_sw_netstats_rx_add(skb->dev, skb->len);
264 
265 	if (dsa_skb_defer_rx_timestamp(p, skb))
266 		return 0;
267 
268 	gro_cells_receive(&p->gcells, skb);
269 
270 	return 0;
271 }
272 
273 #ifdef CONFIG_PM_SLEEP
274 static bool dsa_port_is_initialized(const struct dsa_port *dp)
275 {
276 	return dp->type == DSA_PORT_TYPE_USER && dp->slave;
277 }
278 
279 int dsa_switch_suspend(struct dsa_switch *ds)
280 {
281 	struct dsa_port *dp;
282 	int ret = 0;
283 
284 	/* Suspend slave network devices */
285 	dsa_switch_for_each_port(dp, ds) {
286 		if (!dsa_port_is_initialized(dp))
287 			continue;
288 
289 		ret = dsa_slave_suspend(dp->slave);
290 		if (ret)
291 			return ret;
292 	}
293 
294 	if (ds->ops->suspend)
295 		ret = ds->ops->suspend(ds);
296 
297 	return ret;
298 }
299 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
300 
301 int dsa_switch_resume(struct dsa_switch *ds)
302 {
303 	struct dsa_port *dp;
304 	int ret = 0;
305 
306 	if (ds->ops->resume)
307 		ret = ds->ops->resume(ds);
308 
309 	if (ret)
310 		return ret;
311 
312 	/* Resume slave network devices */
313 	dsa_switch_for_each_port(dp, ds) {
314 		if (!dsa_port_is_initialized(dp))
315 			continue;
316 
317 		ret = dsa_slave_resume(dp->slave);
318 		if (ret)
319 			return ret;
320 	}
321 
322 	return 0;
323 }
324 EXPORT_SYMBOL_GPL(dsa_switch_resume);
325 #endif
326 
327 static struct packet_type dsa_pack_type __read_mostly = {
328 	.type	= cpu_to_be16(ETH_P_XDSA),
329 	.func	= dsa_switch_rcv,
330 };
331 
332 static struct workqueue_struct *dsa_owq;
333 
334 bool dsa_schedule_work(struct work_struct *work)
335 {
336 	return queue_work(dsa_owq, work);
337 }
338 
339 void dsa_flush_workqueue(void)
340 {
341 	flush_workqueue(dsa_owq);
342 }
343 EXPORT_SYMBOL_GPL(dsa_flush_workqueue);
344 
345 int dsa_devlink_param_get(struct devlink *dl, u32 id,
346 			  struct devlink_param_gset_ctx *ctx)
347 {
348 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
349 
350 	if (!ds->ops->devlink_param_get)
351 		return -EOPNOTSUPP;
352 
353 	return ds->ops->devlink_param_get(ds, id, ctx);
354 }
355 EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
356 
357 int dsa_devlink_param_set(struct devlink *dl, u32 id,
358 			  struct devlink_param_gset_ctx *ctx)
359 {
360 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
361 
362 	if (!ds->ops->devlink_param_set)
363 		return -EOPNOTSUPP;
364 
365 	return ds->ops->devlink_param_set(ds, id, ctx);
366 }
367 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
368 
369 int dsa_devlink_params_register(struct dsa_switch *ds,
370 				const struct devlink_param *params,
371 				size_t params_count)
372 {
373 	return devlink_params_register(ds->devlink, params, params_count);
374 }
375 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
376 
377 void dsa_devlink_params_unregister(struct dsa_switch *ds,
378 				   const struct devlink_param *params,
379 				   size_t params_count)
380 {
381 	devlink_params_unregister(ds->devlink, params, params_count);
382 }
383 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
384 
385 int dsa_devlink_resource_register(struct dsa_switch *ds,
386 				  const char *resource_name,
387 				  u64 resource_size,
388 				  u64 resource_id,
389 				  u64 parent_resource_id,
390 				  const struct devlink_resource_size_params *size_params)
391 {
392 	return devlink_resource_register(ds->devlink, resource_name,
393 					 resource_size, resource_id,
394 					 parent_resource_id,
395 					 size_params);
396 }
397 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
398 
399 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
400 {
401 	devlink_resources_unregister(ds->devlink);
402 }
403 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
404 
405 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
406 					   u64 resource_id,
407 					   devlink_resource_occ_get_t *occ_get,
408 					   void *occ_get_priv)
409 {
410 	return devlink_resource_occ_get_register(ds->devlink, resource_id,
411 						 occ_get, occ_get_priv);
412 }
413 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
414 
415 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
416 					     u64 resource_id)
417 {
418 	devlink_resource_occ_get_unregister(ds->devlink, resource_id);
419 }
420 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
421 
422 struct devlink_region *
423 dsa_devlink_region_create(struct dsa_switch *ds,
424 			  const struct devlink_region_ops *ops,
425 			  u32 region_max_snapshots, u64 region_size)
426 {
427 	return devlink_region_create(ds->devlink, ops, region_max_snapshots,
428 				     region_size);
429 }
430 EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
431 
432 struct devlink_region *
433 dsa_devlink_port_region_create(struct dsa_switch *ds,
434 			       int port,
435 			       const struct devlink_port_region_ops *ops,
436 			       u32 region_max_snapshots, u64 region_size)
437 {
438 	struct dsa_port *dp = dsa_to_port(ds, port);
439 
440 	return devlink_port_region_create(&dp->devlink_port, ops,
441 					  region_max_snapshots,
442 					  region_size);
443 }
444 EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
445 
446 void dsa_devlink_region_destroy(struct devlink_region *region)
447 {
448 	devlink_region_destroy(region);
449 }
450 EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
451 
452 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
453 {
454 	if (!netdev || !dsa_slave_dev_check(netdev))
455 		return ERR_PTR(-ENODEV);
456 
457 	return dsa_slave_to_port(netdev);
458 }
459 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
460 
461 bool dsa_db_equal(const struct dsa_db *a, const struct dsa_db *b)
462 {
463 	if (a->type != b->type)
464 		return false;
465 
466 	switch (a->type) {
467 	case DSA_DB_PORT:
468 		return a->dp == b->dp;
469 	case DSA_DB_LAG:
470 		return a->lag.dev == b->lag.dev;
471 	case DSA_DB_BRIDGE:
472 		return a->bridge.num == b->bridge.num;
473 	default:
474 		WARN_ON(1);
475 		return false;
476 	}
477 }
478 
479 bool dsa_fdb_present_in_other_db(struct dsa_switch *ds, int port,
480 				 const unsigned char *addr, u16 vid,
481 				 struct dsa_db db)
482 {
483 	struct dsa_port *dp = dsa_to_port(ds, port);
484 	struct dsa_mac_addr *a;
485 
486 	lockdep_assert_held(&dp->addr_lists_lock);
487 
488 	list_for_each_entry(a, &dp->fdbs, list) {
489 		if (!ether_addr_equal(a->addr, addr) || a->vid != vid)
490 			continue;
491 
492 		if (a->db.type == db.type && !dsa_db_equal(&a->db, &db))
493 			return true;
494 	}
495 
496 	return false;
497 }
498 EXPORT_SYMBOL_GPL(dsa_fdb_present_in_other_db);
499 
500 bool dsa_mdb_present_in_other_db(struct dsa_switch *ds, int port,
501 				 const struct switchdev_obj_port_mdb *mdb,
502 				 struct dsa_db db)
503 {
504 	struct dsa_port *dp = dsa_to_port(ds, port);
505 	struct dsa_mac_addr *a;
506 
507 	lockdep_assert_held(&dp->addr_lists_lock);
508 
509 	list_for_each_entry(a, &dp->mdbs, list) {
510 		if (!ether_addr_equal(a->addr, mdb->addr) || a->vid != mdb->vid)
511 			continue;
512 
513 		if (a->db.type == db.type && !dsa_db_equal(&a->db, &db))
514 			return true;
515 	}
516 
517 	return false;
518 }
519 EXPORT_SYMBOL_GPL(dsa_mdb_present_in_other_db);
520 
521 static int __init dsa_init_module(void)
522 {
523 	int rc;
524 
525 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
526 					  WQ_MEM_RECLAIM);
527 	if (!dsa_owq)
528 		return -ENOMEM;
529 
530 	rc = dsa_slave_register_notifier();
531 	if (rc)
532 		goto register_notifier_fail;
533 
534 	dev_add_pack(&dsa_pack_type);
535 
536 	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
537 				THIS_MODULE);
538 
539 	rc = rtnl_link_register(&dsa_link_ops);
540 	if (rc)
541 		goto netlink_register_fail;
542 
543 	return 0;
544 
545 netlink_register_fail:
546 	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
547 	dsa_slave_unregister_notifier();
548 	dev_remove_pack(&dsa_pack_type);
549 register_notifier_fail:
550 	destroy_workqueue(dsa_owq);
551 
552 	return rc;
553 }
554 module_init(dsa_init_module);
555 
556 static void __exit dsa_cleanup_module(void)
557 {
558 	rtnl_link_unregister(&dsa_link_ops);
559 	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
560 
561 	dsa_slave_unregister_notifier();
562 	dev_remove_pack(&dsa_pack_type);
563 	destroy_workqueue(dsa_owq);
564 }
565 module_exit(dsa_cleanup_module);
566 
567 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
568 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
569 MODULE_LICENSE("GPL");
570 MODULE_ALIAS("platform:dsa");
571