xref: /openbmc/linux/net/dsa/dsa.c (revision 3a35093a) 
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 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
88 {
89 	struct dsa_tag_driver *dsa_tag_driver;
90 	const struct dsa_device_ops *ops;
91 	bool found = false;
92 
93 	request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
94 
95 	mutex_lock(&dsa_tag_drivers_lock);
96 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
97 		ops = dsa_tag_driver->ops;
98 		if (ops->proto == tag_protocol) {
99 			found = true;
100 			break;
101 		}
102 	}
103 
104 	if (found) {
105 		if (!try_module_get(dsa_tag_driver->owner))
106 			ops = ERR_PTR(-ENOPROTOOPT);
107 	} else {
108 		ops = ERR_PTR(-ENOPROTOOPT);
109 	}
110 
111 	mutex_unlock(&dsa_tag_drivers_lock);
112 
113 	return ops;
114 }
115 
116 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
117 {
118 	struct dsa_tag_driver *dsa_tag_driver;
119 
120 	mutex_lock(&dsa_tag_drivers_lock);
121 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
122 		if (dsa_tag_driver->ops == ops) {
123 			module_put(dsa_tag_driver->owner);
124 			break;
125 		}
126 	}
127 	mutex_unlock(&dsa_tag_drivers_lock);
128 }
129 
130 static int dev_is_class(struct device *dev, void *class)
131 {
132 	if (dev->class != NULL && !strcmp(dev->class->name, class))
133 		return 1;
134 
135 	return 0;
136 }
137 
138 static struct device *dev_find_class(struct device *parent, char *class)
139 {
140 	if (dev_is_class(parent, class)) {
141 		get_device(parent);
142 		return parent;
143 	}
144 
145 	return device_find_child(parent, class, dev_is_class);
146 }
147 
148 struct net_device *dsa_dev_to_net_device(struct device *dev)
149 {
150 	struct device *d;
151 
152 	d = dev_find_class(dev, "net");
153 	if (d != NULL) {
154 		struct net_device *nd;
155 
156 		nd = to_net_dev(d);
157 		dev_hold(nd);
158 		put_device(d);
159 
160 		return nd;
161 	}
162 
163 	return NULL;
164 }
165 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
166 
167 /* Determine if we should defer delivery of skb until we have a rx timestamp.
168  *
169  * Called from dsa_switch_rcv. For now, this will only work if tagging is
170  * enabled on the switch. Normally the MAC driver would retrieve the hardware
171  * timestamp when it reads the packet out of the hardware. However in a DSA
172  * switch, the DSA driver owning the interface to which the packet is
173  * delivered is never notified unless we do so here.
174  */
175 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
176 				       struct sk_buff *skb)
177 {
178 	struct dsa_switch *ds = p->dp->ds;
179 	unsigned int type;
180 
181 	if (skb_headroom(skb) < ETH_HLEN)
182 		return false;
183 
184 	__skb_push(skb, ETH_HLEN);
185 
186 	type = ptp_classify_raw(skb);
187 
188 	__skb_pull(skb, ETH_HLEN);
189 
190 	if (type == PTP_CLASS_NONE)
191 		return false;
192 
193 	if (likely(ds->ops->port_rxtstamp))
194 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
195 
196 	return false;
197 }
198 
199 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
200 			  struct packet_type *pt, struct net_device *unused)
201 {
202 	struct dsa_port *cpu_dp = dev->dsa_ptr;
203 	struct sk_buff *nskb = NULL;
204 	struct dsa_slave_priv *p;
205 
206 	if (unlikely(!cpu_dp)) {
207 		kfree_skb(skb);
208 		return 0;
209 	}
210 
211 	skb = skb_unshare(skb, GFP_ATOMIC);
212 	if (!skb)
213 		return 0;
214 
215 	nskb = cpu_dp->rcv(skb, dev, pt);
216 	if (!nskb) {
217 		kfree_skb(skb);
218 		return 0;
219 	}
220 
221 	skb = nskb;
222 	p = netdev_priv(skb->dev);
223 	skb_push(skb, ETH_HLEN);
224 	skb->pkt_type = PACKET_HOST;
225 	skb->protocol = eth_type_trans(skb, skb->dev);
226 
227 	if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
228 		nskb = dsa_untag_bridge_pvid(skb);
229 		if (!nskb) {
230 			kfree_skb(skb);
231 			return 0;
232 		}
233 		skb = nskb;
234 	}
235 
236 	dev_sw_netstats_rx_add(skb->dev, skb->len);
237 
238 	if (dsa_skb_defer_rx_timestamp(p, skb))
239 		return 0;
240 
241 	gro_cells_receive(&p->gcells, skb);
242 
243 	return 0;
244 }
245 
246 #ifdef CONFIG_PM_SLEEP
247 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
248 {
249 	const struct dsa_port *dp = dsa_to_port(ds, p);
250 
251 	return dp->type == DSA_PORT_TYPE_USER && dp->slave;
252 }
253 
254 int dsa_switch_suspend(struct dsa_switch *ds)
255 {
256 	int i, ret = 0;
257 
258 	/* Suspend slave network devices */
259 	for (i = 0; i < ds->num_ports; i++) {
260 		if (!dsa_is_port_initialized(ds, i))
261 			continue;
262 
263 		ret = dsa_slave_suspend(dsa_to_port(ds, i)->slave);
264 		if (ret)
265 			return ret;
266 	}
267 
268 	if (ds->ops->suspend)
269 		ret = ds->ops->suspend(ds);
270 
271 	return ret;
272 }
273 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
274 
275 int dsa_switch_resume(struct dsa_switch *ds)
276 {
277 	int i, ret = 0;
278 
279 	if (ds->ops->resume)
280 		ret = ds->ops->resume(ds);
281 
282 	if (ret)
283 		return ret;
284 
285 	/* Resume slave network devices */
286 	for (i = 0; i < ds->num_ports; i++) {
287 		if (!dsa_is_port_initialized(ds, i))
288 			continue;
289 
290 		ret = dsa_slave_resume(dsa_to_port(ds, i)->slave);
291 		if (ret)
292 			return ret;
293 	}
294 
295 	return 0;
296 }
297 EXPORT_SYMBOL_GPL(dsa_switch_resume);
298 #endif
299 
300 static struct packet_type dsa_pack_type __read_mostly = {
301 	.type	= cpu_to_be16(ETH_P_XDSA),
302 	.func	= dsa_switch_rcv,
303 };
304 
305 static struct workqueue_struct *dsa_owq;
306 
307 bool dsa_schedule_work(struct work_struct *work)
308 {
309 	return queue_work(dsa_owq, work);
310 }
311 
312 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
313 
314 int register_dsa_notifier(struct notifier_block *nb)
315 {
316 	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
317 }
318 EXPORT_SYMBOL_GPL(register_dsa_notifier);
319 
320 int unregister_dsa_notifier(struct notifier_block *nb)
321 {
322 	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
323 }
324 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
325 
326 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
327 		       struct dsa_notifier_info *info)
328 {
329 	info->dev = dev;
330 	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
331 }
332 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
333 
334 int dsa_devlink_param_get(struct devlink *dl, u32 id,
335 			  struct devlink_param_gset_ctx *ctx)
336 {
337 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
338 
339 	if (!ds->ops->devlink_param_get)
340 		return -EOPNOTSUPP;
341 
342 	return ds->ops->devlink_param_get(ds, id, ctx);
343 }
344 EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
345 
346 int dsa_devlink_param_set(struct devlink *dl, u32 id,
347 			  struct devlink_param_gset_ctx *ctx)
348 {
349 	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
350 
351 	if (!ds->ops->devlink_param_set)
352 		return -EOPNOTSUPP;
353 
354 	return ds->ops->devlink_param_set(ds, id, ctx);
355 }
356 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
357 
358 int dsa_devlink_params_register(struct dsa_switch *ds,
359 				const struct devlink_param *params,
360 				size_t params_count)
361 {
362 	return devlink_params_register(ds->devlink, params, params_count);
363 }
364 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
365 
366 void dsa_devlink_params_unregister(struct dsa_switch *ds,
367 				   const struct devlink_param *params,
368 				   size_t params_count)
369 {
370 	devlink_params_unregister(ds->devlink, params, params_count);
371 }
372 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
373 
374 int dsa_devlink_resource_register(struct dsa_switch *ds,
375 				  const char *resource_name,
376 				  u64 resource_size,
377 				  u64 resource_id,
378 				  u64 parent_resource_id,
379 				  const struct devlink_resource_size_params *size_params)
380 {
381 	return devlink_resource_register(ds->devlink, resource_name,
382 					 resource_size, resource_id,
383 					 parent_resource_id,
384 					 size_params);
385 }
386 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
387 
388 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
389 {
390 	devlink_resources_unregister(ds->devlink, NULL);
391 }
392 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
393 
394 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
395 					   u64 resource_id,
396 					   devlink_resource_occ_get_t *occ_get,
397 					   void *occ_get_priv)
398 {
399 	return devlink_resource_occ_get_register(ds->devlink, resource_id,
400 						 occ_get, occ_get_priv);
401 }
402 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
403 
404 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
405 					     u64 resource_id)
406 {
407 	devlink_resource_occ_get_unregister(ds->devlink, resource_id);
408 }
409 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
410 
411 struct devlink_region *
412 dsa_devlink_region_create(struct dsa_switch *ds,
413 			  const struct devlink_region_ops *ops,
414 			  u32 region_max_snapshots, u64 region_size)
415 {
416 	return devlink_region_create(ds->devlink, ops, region_max_snapshots,
417 				     region_size);
418 }
419 EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
420 
421 struct devlink_region *
422 dsa_devlink_port_region_create(struct dsa_switch *ds,
423 			       int port,
424 			       const struct devlink_port_region_ops *ops,
425 			       u32 region_max_snapshots, u64 region_size)
426 {
427 	struct dsa_port *dp = dsa_to_port(ds, port);
428 
429 	return devlink_port_region_create(&dp->devlink_port, ops,
430 					  region_max_snapshots,
431 					  region_size);
432 }
433 EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
434 
435 void dsa_devlink_region_destroy(struct devlink_region *region)
436 {
437 	devlink_region_destroy(region);
438 }
439 EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
440 
441 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
442 {
443 	if (!netdev || !dsa_slave_dev_check(netdev))
444 		return ERR_PTR(-ENODEV);
445 
446 	return dsa_slave_to_port(netdev);
447 }
448 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
449 
450 static int __init dsa_init_module(void)
451 {
452 	int rc;
453 
454 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
455 					  WQ_MEM_RECLAIM);
456 	if (!dsa_owq)
457 		return -ENOMEM;
458 
459 	rc = dsa_slave_register_notifier();
460 	if (rc)
461 		goto register_notifier_fail;
462 
463 	dev_add_pack(&dsa_pack_type);
464 
465 	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
466 				THIS_MODULE);
467 
468 	return 0;
469 
470 register_notifier_fail:
471 	destroy_workqueue(dsa_owq);
472 
473 	return rc;
474 }
475 module_init(dsa_init_module);
476 
477 static void __exit dsa_cleanup_module(void)
478 {
479 	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
480 
481 	dsa_slave_unregister_notifier();
482 	dev_remove_pack(&dsa_pack_type);
483 	destroy_workqueue(dsa_owq);
484 }
485 module_exit(dsa_cleanup_module);
486 
487 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
488 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
489 MODULE_LICENSE("GPL");
490 MODULE_ALIAS("platform:dsa");
491