xref: /openbmc/linux/net/dsa/dsa.c (revision a13f2ef1) 
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 pcpu_sw_netstats *s;
205 	struct dsa_slave_priv *p;
206 
207 	if (unlikely(!cpu_dp)) {
208 		kfree_skb(skb);
209 		return 0;
210 	}
211 
212 	skb = skb_unshare(skb, GFP_ATOMIC);
213 	if (!skb)
214 		return 0;
215 
216 	nskb = cpu_dp->rcv(skb, dev, pt);
217 	if (!nskb) {
218 		kfree_skb(skb);
219 		return 0;
220 	}
221 
222 	skb = nskb;
223 	p = netdev_priv(skb->dev);
224 	skb_push(skb, ETH_HLEN);
225 	skb->pkt_type = PACKET_HOST;
226 	skb->protocol = eth_type_trans(skb, skb->dev);
227 
228 	s = this_cpu_ptr(p->stats64);
229 	u64_stats_update_begin(&s->syncp);
230 	s->rx_packets++;
231 	s->rx_bytes += skb->len;
232 	u64_stats_update_end(&s->syncp);
233 
234 	if (dsa_skb_defer_rx_timestamp(p, skb))
235 		return 0;
236 
237 	gro_cells_receive(&p->gcells, skb);
238 
239 	return 0;
240 }
241 
242 #ifdef CONFIG_PM_SLEEP
243 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
244 {
245 	const struct dsa_port *dp = dsa_to_port(ds, p);
246 
247 	return dp->type == DSA_PORT_TYPE_USER && dp->slave;
248 }
249 
250 int dsa_switch_suspend(struct dsa_switch *ds)
251 {
252 	int i, ret = 0;
253 
254 	/* Suspend slave network devices */
255 	for (i = 0; i < ds->num_ports; i++) {
256 		if (!dsa_is_port_initialized(ds, i))
257 			continue;
258 
259 		ret = dsa_slave_suspend(dsa_to_port(ds, i)->slave);
260 		if (ret)
261 			return ret;
262 	}
263 
264 	if (ds->ops->suspend)
265 		ret = ds->ops->suspend(ds);
266 
267 	return ret;
268 }
269 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
270 
271 int dsa_switch_resume(struct dsa_switch *ds)
272 {
273 	int i, ret = 0;
274 
275 	if (ds->ops->resume)
276 		ret = ds->ops->resume(ds);
277 
278 	if (ret)
279 		return ret;
280 
281 	/* Resume slave network devices */
282 	for (i = 0; i < ds->num_ports; i++) {
283 		if (!dsa_is_port_initialized(ds, i))
284 			continue;
285 
286 		ret = dsa_slave_resume(dsa_to_port(ds, i)->slave);
287 		if (ret)
288 			return ret;
289 	}
290 
291 	return 0;
292 }
293 EXPORT_SYMBOL_GPL(dsa_switch_resume);
294 #endif
295 
296 static struct packet_type dsa_pack_type __read_mostly = {
297 	.type	= cpu_to_be16(ETH_P_XDSA),
298 	.func	= dsa_switch_rcv,
299 };
300 
301 static struct workqueue_struct *dsa_owq;
302 
303 bool dsa_schedule_work(struct work_struct *work)
304 {
305 	return queue_work(dsa_owq, work);
306 }
307 
308 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
309 
310 int register_dsa_notifier(struct notifier_block *nb)
311 {
312 	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
313 }
314 EXPORT_SYMBOL_GPL(register_dsa_notifier);
315 
316 int unregister_dsa_notifier(struct notifier_block *nb)
317 {
318 	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
319 }
320 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
321 
322 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
323 		       struct dsa_notifier_info *info)
324 {
325 	info->dev = dev;
326 	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
327 }
328 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
329 
330 int dsa_devlink_param_get(struct devlink *dl, u32 id,
331 			  struct devlink_param_gset_ctx *ctx)
332 {
333 	struct dsa_devlink_priv *dl_priv;
334 	struct dsa_switch *ds;
335 
336 	dl_priv = devlink_priv(dl);
337 	ds = dl_priv->ds;
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_devlink_priv *dl_priv;
350 	struct dsa_switch *ds;
351 
352 	dl_priv = devlink_priv(dl);
353 	ds = dl_priv->ds;
354 
355 	if (!ds->ops->devlink_param_set)
356 		return -EOPNOTSUPP;
357 
358 	return ds->ops->devlink_param_set(ds, id, ctx);
359 }
360 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
361 
362 int dsa_devlink_params_register(struct dsa_switch *ds,
363 				const struct devlink_param *params,
364 				size_t params_count)
365 {
366 	return devlink_params_register(ds->devlink, params, params_count);
367 }
368 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
369 
370 void dsa_devlink_params_unregister(struct dsa_switch *ds,
371 				   const struct devlink_param *params,
372 				   size_t params_count)
373 {
374 	devlink_params_unregister(ds->devlink, params, params_count);
375 }
376 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
377 
378 int dsa_devlink_resource_register(struct dsa_switch *ds,
379 				  const char *resource_name,
380 				  u64 resource_size,
381 				  u64 resource_id,
382 				  u64 parent_resource_id,
383 				  const struct devlink_resource_size_params *size_params)
384 {
385 	return devlink_resource_register(ds->devlink, resource_name,
386 					 resource_size, resource_id,
387 					 parent_resource_id,
388 					 size_params);
389 }
390 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
391 
392 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
393 {
394 	devlink_resources_unregister(ds->devlink, NULL);
395 }
396 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
397 
398 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
399 					   u64 resource_id,
400 					   devlink_resource_occ_get_t *occ_get,
401 					   void *occ_get_priv)
402 {
403 	return devlink_resource_occ_get_register(ds->devlink, resource_id,
404 						 occ_get, occ_get_priv);
405 }
406 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
407 
408 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
409 					     u64 resource_id)
410 {
411 	devlink_resource_occ_get_unregister(ds->devlink, resource_id);
412 }
413 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
414 
415 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
416 {
417 	if (!netdev || !dsa_slave_dev_check(netdev))
418 		return ERR_PTR(-ENODEV);
419 
420 	return dsa_slave_to_port(netdev);
421 }
422 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
423 
424 static int __init dsa_init_module(void)
425 {
426 	int rc;
427 
428 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
429 					  WQ_MEM_RECLAIM);
430 	if (!dsa_owq)
431 		return -ENOMEM;
432 
433 	rc = dsa_slave_register_notifier();
434 	if (rc)
435 		goto register_notifier_fail;
436 
437 	dev_add_pack(&dsa_pack_type);
438 
439 	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
440 				THIS_MODULE);
441 
442 	return 0;
443 
444 register_notifier_fail:
445 	destroy_workqueue(dsa_owq);
446 
447 	return rc;
448 }
449 module_init(dsa_init_module);
450 
451 static void __exit dsa_cleanup_module(void)
452 {
453 	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
454 
455 	dsa_slave_unregister_notifier();
456 	dev_remove_pack(&dsa_pack_type);
457 	destroy_workqueue(dsa_owq);
458 }
459 module_exit(dsa_cleanup_module);
460 
461 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
462 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
463 MODULE_LICENSE("GPL");
464 MODULE_ALIAS("platform:dsa");
465