1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Handling of a master device, switching frames via its switch fabric CPU port
4  *
5  * Copyright (c) 2017 Savoir-faire Linux Inc.
6  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
7  */
8 
9 #include "dsa_priv.h"
10 
dsa_master_get_regs_len(struct net_device * dev)11 static int dsa_master_get_regs_len(struct net_device *dev)
12 {
13 	struct dsa_port *cpu_dp = dev->dsa_ptr;
14 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
15 	struct dsa_switch *ds = cpu_dp->ds;
16 	int port = cpu_dp->index;
17 	int ret = 0;
18 	int len;
19 
20 	if (ops->get_regs_len) {
21 		len = ops->get_regs_len(dev);
22 		if (len < 0)
23 			return len;
24 		ret += len;
25 	}
26 
27 	ret += sizeof(struct ethtool_drvinfo);
28 	ret += sizeof(struct ethtool_regs);
29 
30 	if (ds->ops->get_regs_len) {
31 		len = ds->ops->get_regs_len(ds, port);
32 		if (len < 0)
33 			return len;
34 		ret += len;
35 	}
36 
37 	return ret;
38 }
39 
dsa_master_get_regs(struct net_device * dev,struct ethtool_regs * regs,void * data)40 static void dsa_master_get_regs(struct net_device *dev,
41 				struct ethtool_regs *regs, void *data)
42 {
43 	struct dsa_port *cpu_dp = dev->dsa_ptr;
44 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
45 	struct dsa_switch *ds = cpu_dp->ds;
46 	struct ethtool_drvinfo *cpu_info;
47 	struct ethtool_regs *cpu_regs;
48 	int port = cpu_dp->index;
49 	int len;
50 
51 	if (ops->get_regs_len && ops->get_regs) {
52 		len = ops->get_regs_len(dev);
53 		if (len < 0)
54 			return;
55 		regs->len = len;
56 		ops->get_regs(dev, regs, data);
57 		data += regs->len;
58 	}
59 
60 	cpu_info = (struct ethtool_drvinfo *)data;
61 	strscpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver));
62 	data += sizeof(*cpu_info);
63 	cpu_regs = (struct ethtool_regs *)data;
64 	data += sizeof(*cpu_regs);
65 
66 	if (ds->ops->get_regs_len && ds->ops->get_regs) {
67 		len = ds->ops->get_regs_len(ds, port);
68 		if (len < 0)
69 			return;
70 		cpu_regs->len = len;
71 		ds->ops->get_regs(ds, port, cpu_regs, data);
72 	}
73 }
74 
dsa_master_get_ethtool_stats(struct net_device * dev,struct ethtool_stats * stats,uint64_t * data)75 static void dsa_master_get_ethtool_stats(struct net_device *dev,
76 					 struct ethtool_stats *stats,
77 					 uint64_t *data)
78 {
79 	struct dsa_port *cpu_dp = dev->dsa_ptr;
80 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
81 	struct dsa_switch *ds = cpu_dp->ds;
82 	int port = cpu_dp->index;
83 	int count = 0;
84 
85 	if (ops->get_sset_count && ops->get_ethtool_stats) {
86 		count = ops->get_sset_count(dev, ETH_SS_STATS);
87 		ops->get_ethtool_stats(dev, stats, data);
88 	}
89 
90 	if (ds->ops->get_ethtool_stats)
91 		ds->ops->get_ethtool_stats(ds, port, data + count);
92 }
93 
dsa_master_get_ethtool_phy_stats(struct net_device * dev,struct ethtool_stats * stats,uint64_t * data)94 static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
95 					     struct ethtool_stats *stats,
96 					     uint64_t *data)
97 {
98 	struct dsa_port *cpu_dp = dev->dsa_ptr;
99 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
100 	struct dsa_switch *ds = cpu_dp->ds;
101 	int port = cpu_dp->index;
102 	int count = 0;
103 
104 	if (dev->phydev && !ops->get_ethtool_phy_stats) {
105 		count = phy_ethtool_get_sset_count(dev->phydev);
106 		if (count >= 0)
107 			phy_ethtool_get_stats(dev->phydev, stats, data);
108 	} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
109 		count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
110 		ops->get_ethtool_phy_stats(dev, stats, data);
111 	}
112 
113 	if (count < 0)
114 		count = 0;
115 
116 	if (ds->ops->get_ethtool_phy_stats)
117 		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
118 }
119 
dsa_master_get_sset_count(struct net_device * dev,int sset)120 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
121 {
122 	struct dsa_port *cpu_dp = dev->dsa_ptr;
123 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
124 	struct dsa_switch *ds = cpu_dp->ds;
125 	int count = 0;
126 
127 	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
128 	    !ops->get_ethtool_phy_stats)
129 		count = phy_ethtool_get_sset_count(dev->phydev);
130 	else if (ops->get_sset_count)
131 		count = ops->get_sset_count(dev, sset);
132 
133 	if (count < 0)
134 		count = 0;
135 
136 	if (ds->ops->get_sset_count)
137 		count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
138 
139 	return count;
140 }
141 
dsa_master_get_strings(struct net_device * dev,uint32_t stringset,uint8_t * data)142 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
143 				   uint8_t *data)
144 {
145 	struct dsa_port *cpu_dp = dev->dsa_ptr;
146 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
147 	struct dsa_switch *ds = cpu_dp->ds;
148 	int port = cpu_dp->index;
149 	int len = ETH_GSTRING_LEN;
150 	int mcount = 0, count, i;
151 	uint8_t pfx[4];
152 	uint8_t *ndata;
153 
154 	snprintf(pfx, sizeof(pfx), "p%.2d", port);
155 	/* We do not want to be NULL-terminated, since this is a prefix */
156 	pfx[sizeof(pfx) - 1] = '_';
157 
158 	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
159 	    !ops->get_ethtool_phy_stats) {
160 		mcount = phy_ethtool_get_sset_count(dev->phydev);
161 		if (mcount < 0)
162 			mcount = 0;
163 		else
164 			phy_ethtool_get_strings(dev->phydev, data);
165 	} else if (ops->get_sset_count && ops->get_strings) {
166 		mcount = ops->get_sset_count(dev, stringset);
167 		if (mcount < 0)
168 			mcount = 0;
169 		ops->get_strings(dev, stringset, data);
170 	}
171 
172 	if (ds->ops->get_strings) {
173 		ndata = data + mcount * len;
174 		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
175 		 * the output after to prepend our CPU port prefix we
176 		 * constructed earlier
177 		 */
178 		ds->ops->get_strings(ds, port, stringset, ndata);
179 		count = ds->ops->get_sset_count(ds, port, stringset);
180 		if (count < 0)
181 			return;
182 		for (i = 0; i < count; i++) {
183 			memmove(ndata + (i * len + sizeof(pfx)),
184 				ndata + i * len, len - sizeof(pfx));
185 			memcpy(ndata + i * len, pfx, sizeof(pfx));
186 		}
187 	}
188 }
189 
dsa_master_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)190 static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
191 {
192 	struct dsa_port *cpu_dp = dev->dsa_ptr;
193 	struct dsa_switch *ds = cpu_dp->ds;
194 	struct dsa_switch_tree *dst;
195 	int err = -EOPNOTSUPP;
196 	struct dsa_port *dp;
197 
198 	dst = ds->dst;
199 
200 	switch (cmd) {
201 	case SIOCGHWTSTAMP:
202 	case SIOCSHWTSTAMP:
203 		/* Deny PTP operations on master if there is at least one
204 		 * switch in the tree that is PTP capable.
205 		 */
206 		list_for_each_entry(dp, &dst->ports, list)
207 			if (dsa_port_supports_hwtstamp(dp, ifr))
208 				return -EBUSY;
209 		break;
210 	}
211 
212 	if (dev->netdev_ops->ndo_eth_ioctl)
213 		err = dev->netdev_ops->ndo_eth_ioctl(dev, ifr, cmd);
214 
215 	return err;
216 }
217 
218 static const struct dsa_netdevice_ops dsa_netdev_ops = {
219 	.ndo_eth_ioctl = dsa_master_ioctl,
220 };
221 
dsa_master_ethtool_setup(struct net_device * dev)222 static int dsa_master_ethtool_setup(struct net_device *dev)
223 {
224 	struct dsa_port *cpu_dp = dev->dsa_ptr;
225 	struct dsa_switch *ds = cpu_dp->ds;
226 	struct ethtool_ops *ops;
227 
228 	if (netif_is_lag_master(dev))
229 		return 0;
230 
231 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
232 	if (!ops)
233 		return -ENOMEM;
234 
235 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
236 	if (cpu_dp->orig_ethtool_ops)
237 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
238 
239 	ops->get_regs_len = dsa_master_get_regs_len;
240 	ops->get_regs = dsa_master_get_regs;
241 	ops->get_sset_count = dsa_master_get_sset_count;
242 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
243 	ops->get_strings = dsa_master_get_strings;
244 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
245 
246 	dev->ethtool_ops = ops;
247 
248 	return 0;
249 }
250 
dsa_master_ethtool_teardown(struct net_device * dev)251 static void dsa_master_ethtool_teardown(struct net_device *dev)
252 {
253 	struct dsa_port *cpu_dp = dev->dsa_ptr;
254 
255 	if (netif_is_lag_master(dev))
256 		return;
257 
258 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
259 	cpu_dp->orig_ethtool_ops = NULL;
260 }
261 
dsa_netdev_ops_set(struct net_device * dev,const struct dsa_netdevice_ops * ops)262 static void dsa_netdev_ops_set(struct net_device *dev,
263 			       const struct dsa_netdevice_ops *ops)
264 {
265 	if (netif_is_lag_master(dev))
266 		return;
267 
268 	dev->dsa_ptr->netdev_ops = ops;
269 }
270 
271 /* Keep the master always promiscuous if the tagging protocol requires that
272  * (garbles MAC DA) or if it doesn't support unicast filtering, case in which
273  * it would revert to promiscuous mode as soon as we call dev_uc_add() on it
274  * anyway.
275  */
dsa_master_set_promiscuity(struct net_device * dev,int inc)276 static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
277 {
278 	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
279 
280 	if ((dev->priv_flags & IFF_UNICAST_FLT) && !ops->promisc_on_master)
281 		return;
282 
283 	ASSERT_RTNL();
284 
285 	dev_set_promiscuity(dev, inc);
286 }
287 
tagging_show(struct device * d,struct device_attribute * attr,char * buf)288 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
289 			    char *buf)
290 {
291 	struct net_device *dev = to_net_dev(d);
292 	struct dsa_port *cpu_dp = dev->dsa_ptr;
293 
294 	return sprintf(buf, "%s\n",
295 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
296 }
297 
tagging_store(struct device * d,struct device_attribute * attr,const char * buf,size_t count)298 static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
299 			     const char *buf, size_t count)
300 {
301 	const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
302 	struct net_device *dev = to_net_dev(d);
303 	struct dsa_port *cpu_dp = dev->dsa_ptr;
304 	int err;
305 
306 	old_tag_ops = cpu_dp->tag_ops;
307 	new_tag_ops = dsa_find_tagger_by_name(buf);
308 	/* Bad tagger name, or module is not loaded? */
309 	if (IS_ERR(new_tag_ops))
310 		return PTR_ERR(new_tag_ops);
311 
312 	if (new_tag_ops == old_tag_ops)
313 		/* Drop the temporarily held duplicate reference, since
314 		 * the DSA switch tree uses this tagger.
315 		 */
316 		goto out;
317 
318 	err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, new_tag_ops,
319 					old_tag_ops);
320 	if (err) {
321 		/* On failure the old tagger is restored, so we don't need the
322 		 * driver for the new one.
323 		 */
324 		dsa_tag_driver_put(new_tag_ops);
325 		return err;
326 	}
327 
328 	/* On success we no longer need the module for the old tagging protocol
329 	 */
330 out:
331 	dsa_tag_driver_put(old_tag_ops);
332 	return count;
333 }
334 static DEVICE_ATTR_RW(tagging);
335 
336 static struct attribute *dsa_slave_attrs[] = {
337 	&dev_attr_tagging.attr,
338 	NULL
339 };
340 
341 static const struct attribute_group dsa_group = {
342 	.name	= "dsa",
343 	.attrs	= dsa_slave_attrs,
344 };
345 
dsa_master_reset_mtu(struct net_device * dev)346 static void dsa_master_reset_mtu(struct net_device *dev)
347 {
348 	int err;
349 
350 	err = dev_set_mtu(dev, ETH_DATA_LEN);
351 	if (err)
352 		netdev_dbg(dev,
353 			   "Unable to reset MTU to exclude DSA overheads\n");
354 }
355 
dsa_master_setup(struct net_device * dev,struct dsa_port * cpu_dp)356 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
357 {
358 	const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;
359 	struct dsa_switch *ds = cpu_dp->ds;
360 	struct device_link *consumer_link;
361 	int mtu, ret;
362 
363 	mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);
364 
365 	/* The DSA master must use SET_NETDEV_DEV for this to work. */
366 	if (!netif_is_lag_master(dev)) {
367 		consumer_link = device_link_add(ds->dev, dev->dev.parent,
368 						DL_FLAG_AUTOREMOVE_CONSUMER);
369 		if (!consumer_link)
370 			netdev_err(dev,
371 				   "Failed to create a device link to DSA switch %s\n",
372 				   dev_name(ds->dev));
373 	}
374 
375 	/* The switch driver may not implement ->port_change_mtu(), case in
376 	 * which dsa_slave_change_mtu() will not update the master MTU either,
377 	 * so we need to do that here.
378 	 */
379 	ret = dev_set_mtu(dev, mtu);
380 	if (ret)
381 		netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
382 			    ret, mtu);
383 
384 	/* If we use a tagging format that doesn't have an ethertype
385 	 * field, make sure that all packets from this point on get
386 	 * sent to the tag format's receive function.
387 	 */
388 	wmb();
389 
390 	dev->dsa_ptr = cpu_dp;
391 
392 	dsa_master_set_promiscuity(dev, 1);
393 
394 	ret = dsa_master_ethtool_setup(dev);
395 	if (ret)
396 		goto out_err_reset_promisc;
397 
398 	dsa_netdev_ops_set(dev, &dsa_netdev_ops);
399 
400 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
401 	if (ret)
402 		goto out_err_ndo_teardown;
403 
404 	return ret;
405 
406 out_err_ndo_teardown:
407 	dsa_netdev_ops_set(dev, NULL);
408 	dsa_master_ethtool_teardown(dev);
409 out_err_reset_promisc:
410 	dsa_master_set_promiscuity(dev, -1);
411 	return ret;
412 }
413 
dsa_master_teardown(struct net_device * dev)414 void dsa_master_teardown(struct net_device *dev)
415 {
416 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
417 	dsa_netdev_ops_set(dev, NULL);
418 	dsa_master_ethtool_teardown(dev);
419 	dsa_master_reset_mtu(dev);
420 	dsa_master_set_promiscuity(dev, -1);
421 
422 	dev->dsa_ptr = NULL;
423 
424 	/* If we used a tagging format that doesn't have an ethertype
425 	 * field, make sure that all packets from this point get sent
426 	 * without the tag and go through the regular receive path.
427 	 */
428 	wmb();
429 }
430 
dsa_master_lag_setup(struct net_device * lag_dev,struct dsa_port * cpu_dp,struct netdev_lag_upper_info * uinfo,struct netlink_ext_ack * extack)431 int dsa_master_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp,
432 			 struct netdev_lag_upper_info *uinfo,
433 			 struct netlink_ext_ack *extack)
434 {
435 	bool master_setup = false;
436 	int err;
437 
438 	if (!netdev_uses_dsa(lag_dev)) {
439 		err = dsa_master_setup(lag_dev, cpu_dp);
440 		if (err)
441 			return err;
442 
443 		master_setup = true;
444 	}
445 
446 	err = dsa_port_lag_join(cpu_dp, lag_dev, uinfo, extack);
447 	if (err) {
448 		if (extack && !extack->_msg)
449 			NL_SET_ERR_MSG_MOD(extack,
450 					   "CPU port failed to join LAG");
451 		goto out_master_teardown;
452 	}
453 
454 	return 0;
455 
456 out_master_teardown:
457 	if (master_setup)
458 		dsa_master_teardown(lag_dev);
459 	return err;
460 }
461 
462 /* Tear down a master if there isn't any other user port on it,
463  * optionally also destroying LAG information.
464  */
dsa_master_lag_teardown(struct net_device * lag_dev,struct dsa_port * cpu_dp)465 void dsa_master_lag_teardown(struct net_device *lag_dev,
466 			     struct dsa_port *cpu_dp)
467 {
468 	struct net_device *upper;
469 	struct list_head *iter;
470 
471 	dsa_port_lag_leave(cpu_dp, lag_dev);
472 
473 	netdev_for_each_upper_dev_rcu(lag_dev, upper, iter)
474 		if (dsa_slave_dev_check(upper))
475 			return;
476 
477 	dsa_master_teardown(lag_dev);
478 }
479