xref: /openbmc/linux/net/dsa/dsa.c (revision 1cc1e4c8) 
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/platform_device.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/notifier.h>
14 #include <linux/of.h>
15 #include <linux/of_mdio.h>
16 #include <linux/of_platform.h>
17 #include <linux/of_net.h>
18 #include <linux/netdevice.h>
19 #include <linux/sysfs.h>
20 #include <linux/phy_fixed.h>
21 #include <linux/ptp_classify.h>
22 #include <linux/etherdevice.h>
23 
24 #include "dsa_priv.h"
25 
26 static LIST_HEAD(dsa_tag_drivers_list);
27 static DEFINE_MUTEX(dsa_tag_drivers_lock);
28 
29 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
30 					    struct net_device *dev)
31 {
32 	/* Just return the original SKB */
33 	return skb;
34 }
35 
36 static const struct dsa_device_ops none_ops = {
37 	.name	= "none",
38 	.proto	= DSA_TAG_PROTO_NONE,
39 	.xmit	= dsa_slave_notag_xmit,
40 	.rcv	= NULL,
41 };
42 
43 DSA_TAG_DRIVER(none_ops);
44 
45 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
46 				    struct module *owner)
47 {
48 	dsa_tag_driver->owner = owner;
49 
50 	mutex_lock(&dsa_tag_drivers_lock);
51 	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
52 	mutex_unlock(&dsa_tag_drivers_lock);
53 }
54 
55 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
56 			      unsigned int count, struct module *owner)
57 {
58 	unsigned int i;
59 
60 	for (i = 0; i < count; i++)
61 		dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
62 }
63 
64 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
65 {
66 	mutex_lock(&dsa_tag_drivers_lock);
67 	list_del(&dsa_tag_driver->list);
68 	mutex_unlock(&dsa_tag_drivers_lock);
69 }
70 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
71 
72 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
73 				unsigned int count)
74 {
75 	unsigned int i;
76 
77 	for (i = 0; i < count; i++)
78 		dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
79 }
80 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
81 
82 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
83 {
84 	return ops->name;
85 };
86 
87 /* Function takes a reference on the module owning the tagger,
88  * so dsa_tag_driver_put must be called afterwards.
89  */
90 const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf)
91 {
92 	const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
93 	struct dsa_tag_driver *dsa_tag_driver;
94 
95 	mutex_lock(&dsa_tag_drivers_lock);
96 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
97 		const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
98 
99 		if (!sysfs_streq(buf, tmp->name))
100 			continue;
101 
102 		if (!try_module_get(dsa_tag_driver->owner))
103 			break;
104 
105 		ops = tmp;
106 		break;
107 	}
108 	mutex_unlock(&dsa_tag_drivers_lock);
109 
110 	return ops;
111 }
112 
113 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
114 {
115 	struct dsa_tag_driver *dsa_tag_driver;
116 	const struct dsa_device_ops *ops;
117 	bool found = false;
118 
119 	request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
120 
121 	mutex_lock(&dsa_tag_drivers_lock);
122 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
123 		ops = dsa_tag_driver->ops;
124 		if (ops->proto == tag_protocol) {
125 			found = true;
126 			break;
127 		}
128 	}
129 
130 	if (found) {
131 		if (!try_module_get(dsa_tag_driver->owner))
132 			ops = ERR_PTR(-ENOPROTOOPT);
133 	} else {
134 		ops = ERR_PTR(-ENOPROTOOPT);
135 	}
136 
137 	mutex_unlock(&dsa_tag_drivers_lock);
138 
139 	return ops;
140 }
141 
142 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
143 {
144 	struct dsa_tag_driver *dsa_tag_driver;
145 
146 	mutex_lock(&dsa_tag_drivers_lock);
147 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
148 		if (dsa_tag_driver->ops == ops) {
149 			module_put(dsa_tag_driver->owner);
150 			break;
151 		}
152 	}
153 	mutex_unlock(&dsa_tag_drivers_lock);
154 }
155 
156 static int dev_is_class(struct device *dev, void *class)
157 {
158 	if (dev->class != NULL && !strcmp(dev->class->name, class))
159 		return 1;
160 
161 	return 0;
162 }
163 
164 static struct device *dev_find_class(struct device *parent, char *class)
165 {
166 	if (dev_is_class(parent, class)) {
167 		get_device(parent);
168 		return parent;
169 	}
170 
171 	return device_find_child(parent, class, dev_is_class);
172 }
173 
174 struct net_device *dsa_dev_to_net_device(struct device *dev)
175 {
176 	struct device *d;
177 
178 	d = dev_find_class(dev, "net");
179 	if (d != NULL) {
180 		struct net_device *nd;
181 
182 		nd = to_net_dev(d);
183 		dev_hold(nd);
184 		put_device(d);
185 
186 		return nd;
187 	}
188 
189 	return NULL;
190 }
191 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
192 
193 /* Determine if we should defer delivery of skb until we have a rx timestamp.
194  *
195  * Called from dsa_switch_rcv. For now, this will only work if tagging is
196  * enabled on the switch. Normally the MAC driver would retrieve the hardware
197  * timestamp when it reads the packet out of the hardware. However in a DSA
198  * switch, the DSA driver owning the interface to which the packet is
199  * delivered is never notified unless we do so here.
200  */
201 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
202 				       struct sk_buff *skb)
203 {
204 	struct dsa_switch *ds = p->dp->ds;
205 	unsigned int type;
206 
207 	if (skb_headroom(skb) < ETH_HLEN)
208 		return false;
209 
210 	__skb_push(skb, ETH_HLEN);
211 
212 	type = ptp_classify_raw(skb);
213 
214 	__skb_pull(skb, ETH_HLEN);
215 
216 	if (type == PTP_CLASS_NONE)
217 		return false;
218 
219 	if (likely(ds->ops->port_rxtstamp))
220 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
221 
222 	return false;
223 }
224 
225 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
226 			  struct packet_type *pt, struct net_device *unused)
227 {
228 	struct dsa_port *cpu_dp = dev->dsa_ptr;
229 	struct sk_buff *nskb = NULL;
230 	struct dsa_slave_priv *p;
231 
232 	if (unlikely(!cpu_dp)) {
233 		kfree_skb(skb);
234 		return 0;
235 	}
236 
237 	skb = skb_unshare(skb, GFP_ATOMIC);
238 	if (!skb)
239 		return 0;
240 
241 	nskb = cpu_dp->rcv(skb, dev);
242 	if (!nskb) {
243 		kfree_skb(skb);
244 		return 0;
245 	}
246 
247 	skb = nskb;
248 	skb_push(skb, ETH_HLEN);
249 	skb->pkt_type = PACKET_HOST;
250 	skb->protocol = eth_type_trans(skb, skb->dev);
251 
252 	if (unlikely(!dsa_slave_dev_check(skb->dev))) {
253 		/* Packet is to be injected directly on an upper
254 		 * device, e.g. a team/bond, so skip all DSA-port
255 		 * specific actions.
256 		 */
257 		netif_rx(skb);
258 		return 0;
259 	}
260 
261 	p = netdev_priv(skb->dev);
262 
263 	if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
264 		nskb = dsa_untag_bridge_pvid(skb);
265 		if (!nskb) {
266 			kfree_skb(skb);
267 			return 0;
268 		}
269 		skb = nskb;
270 	}
271 
272 	dev_sw_netstats_rx_add(skb->dev, skb->len);
273 
274 	if (dsa_skb_defer_rx_timestamp(p, skb))
275 		return 0;
276 
277 	gro_cells_receive(&p->gcells, skb);
278 
279 	return 0;
280 }
281 
282 #ifdef CONFIG_PM_SLEEP
283 static bool dsa_port_is_initialized(const struct dsa_port *dp)
284 {
285 	return dp->type == DSA_PORT_TYPE_USER && dp->slave;
286 }
287 
288 int dsa_switch_suspend(struct dsa_switch *ds)
289 {
290 	struct dsa_port *dp;
291 	int ret = 0;
292 
293 	/* Suspend slave network devices */
294 	dsa_switch_for_each_port(dp, ds) {
295 		if (!dsa_port_is_initialized(dp))
296 			continue;
297 
298 		ret = dsa_slave_suspend(dp->slave);
299 		if (ret)
300 			return ret;
301 	}
302 
303 	if (ds->ops->suspend)
304 		ret = ds->ops->suspend(ds);
305 
306 	return ret;
307 }
308 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
309 
310 int dsa_switch_resume(struct dsa_switch *ds)
311 {
312 	struct dsa_port *dp;
313 	int ret = 0;
314 
315 	if (ds->ops->resume)
316 		ret = ds->ops->resume(ds);
317 
318 	if (ret)
319 		return ret;
320 
321 	/* Resume slave network devices */
322 	dsa_switch_for_each_port(dp, ds) {
323 		if (!dsa_port_is_initialized(dp))
324 			continue;
325 
326 		ret = dsa_slave_resume(dp->slave);
327 		if (ret)
328 			return ret;
329 	}
330 
331 	return 0;
332 }
333 EXPORT_SYMBOL_GPL(dsa_switch_resume);
334 #endif
335 
336 static struct packet_type dsa_pack_type __read_mostly = {
337 	.type	= cpu_to_be16(ETH_P_XDSA),
338 	.func	= dsa_switch_rcv,
339 };
340 
341 static struct workqueue_struct *dsa_owq;
342 
343 bool dsa_schedule_work(struct work_struct *work)
344 {
345 	return queue_work(dsa_owq, work);
346 }
347 
348 void dsa_flush_workqueue(void)
349 {
350 	flush_workqueue(dsa_owq);
351 }
352 
353 int dsa_devlink_param_get(struct devlink *dl, u32 id,
354 			  struct devlink_param_gset_ctx *ctx)
355 {
356 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
357 
358 	if (!ds->ops->devlink_param_get)
359 		return -EOPNOTSUPP;
360 
361 	return ds->ops->devlink_param_get(ds, id, ctx);
362 }
363 EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
364 
365 int dsa_devlink_param_set(struct devlink *dl, u32 id,
366 			  struct devlink_param_gset_ctx *ctx)
367 {
368 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
369 
370 	if (!ds->ops->devlink_param_set)
371 		return -EOPNOTSUPP;
372 
373 	return ds->ops->devlink_param_set(ds, id, ctx);
374 }
375 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
376 
377 int dsa_devlink_params_register(struct dsa_switch *ds,
378 				const struct devlink_param *params,
379 				size_t params_count)
380 {
381 	return devlink_params_register(ds->devlink, params, params_count);
382 }
383 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
384 
385 void dsa_devlink_params_unregister(struct dsa_switch *ds,
386 				   const struct devlink_param *params,
387 				   size_t params_count)
388 {
389 	devlink_params_unregister(ds->devlink, params, params_count);
390 }
391 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
392 
393 int dsa_devlink_resource_register(struct dsa_switch *ds,
394 				  const char *resource_name,
395 				  u64 resource_size,
396 				  u64 resource_id,
397 				  u64 parent_resource_id,
398 				  const struct devlink_resource_size_params *size_params)
399 {
400 	return devlink_resource_register(ds->devlink, resource_name,
401 					 resource_size, resource_id,
402 					 parent_resource_id,
403 					 size_params);
404 }
405 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
406 
407 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
408 {
409 	devlink_resources_unregister(ds->devlink, NULL);
410 }
411 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
412 
413 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
414 					   u64 resource_id,
415 					   devlink_resource_occ_get_t *occ_get,
416 					   void *occ_get_priv)
417 {
418 	return devlink_resource_occ_get_register(ds->devlink, resource_id,
419 						 occ_get, occ_get_priv);
420 }
421 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
422 
423 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
424 					     u64 resource_id)
425 {
426 	devlink_resource_occ_get_unregister(ds->devlink, resource_id);
427 }
428 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
429 
430 struct devlink_region *
431 dsa_devlink_region_create(struct dsa_switch *ds,
432 			  const struct devlink_region_ops *ops,
433 			  u32 region_max_snapshots, u64 region_size)
434 {
435 	return devlink_region_create(ds->devlink, ops, region_max_snapshots,
436 				     region_size);
437 }
438 EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
439 
440 struct devlink_region *
441 dsa_devlink_port_region_create(struct dsa_switch *ds,
442 			       int port,
443 			       const struct devlink_port_region_ops *ops,
444 			       u32 region_max_snapshots, u64 region_size)
445 {
446 	struct dsa_port *dp = dsa_to_port(ds, port);
447 
448 	return devlink_port_region_create(&dp->devlink_port, ops,
449 					  region_max_snapshots,
450 					  region_size);
451 }
452 EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
453 
454 void dsa_devlink_region_destroy(struct devlink_region *region)
455 {
456 	devlink_region_destroy(region);
457 }
458 EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
459 
460 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
461 {
462 	if (!netdev || !dsa_slave_dev_check(netdev))
463 		return ERR_PTR(-ENODEV);
464 
465 	return dsa_slave_to_port(netdev);
466 }
467 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
468 
469 static int __init dsa_init_module(void)
470 {
471 	int rc;
472 
473 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
474 					  WQ_MEM_RECLAIM);
475 	if (!dsa_owq)
476 		return -ENOMEM;
477 
478 	rc = dsa_slave_register_notifier();
479 	if (rc)
480 		goto register_notifier_fail;
481 
482 	dev_add_pack(&dsa_pack_type);
483 
484 	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
485 				THIS_MODULE);
486 
487 	return 0;
488 
489 register_notifier_fail:
490 	destroy_workqueue(dsa_owq);
491 
492 	return rc;
493 }
494 module_init(dsa_init_module);
495 
496 static void __exit dsa_cleanup_module(void)
497 {
498 	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
499 
500 	dsa_slave_unregister_notifier();
501 	dev_remove_pack(&dsa_pack_type);
502 	destroy_workqueue(dsa_owq);
503 }
504 module_exit(dsa_cleanup_module);
505 
506 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
507 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
508 MODULE_LICENSE("GPL");
509 MODULE_ALIAS("platform:dsa");
510