xref: /openbmc/linux/net/dsa/master.c (revision dc023681)
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 
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 
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 	strlcpy(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 
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 
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 
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 
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 
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 (dp->ds->ops->port_hwtstamp_get ||
208 			    dp->ds->ops->port_hwtstamp_set)
209 				return -EBUSY;
210 		break;
211 	}
212 
213 	if (dev->netdev_ops->ndo_eth_ioctl)
214 		err = dev->netdev_ops->ndo_eth_ioctl(dev, ifr, cmd);
215 
216 	return err;
217 }
218 
219 static const struct dsa_netdevice_ops dsa_netdev_ops = {
220 	.ndo_eth_ioctl = dsa_master_ioctl,
221 };
222 
223 static int dsa_master_ethtool_setup(struct net_device *dev)
224 {
225 	struct dsa_port *cpu_dp = dev->dsa_ptr;
226 	struct dsa_switch *ds = cpu_dp->ds;
227 	struct ethtool_ops *ops;
228 
229 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
230 	if (!ops)
231 		return -ENOMEM;
232 
233 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
234 	if (cpu_dp->orig_ethtool_ops)
235 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
236 
237 	ops->get_regs_len = dsa_master_get_regs_len;
238 	ops->get_regs = dsa_master_get_regs;
239 	ops->get_sset_count = dsa_master_get_sset_count;
240 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
241 	ops->get_strings = dsa_master_get_strings;
242 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
243 
244 	dev->ethtool_ops = ops;
245 
246 	return 0;
247 }
248 
249 static void dsa_master_ethtool_teardown(struct net_device *dev)
250 {
251 	struct dsa_port *cpu_dp = dev->dsa_ptr;
252 
253 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
254 	cpu_dp->orig_ethtool_ops = NULL;
255 }
256 
257 static void dsa_netdev_ops_set(struct net_device *dev,
258 			       const struct dsa_netdevice_ops *ops)
259 {
260 	dev->dsa_ptr->netdev_ops = ops;
261 }
262 
263 static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
264 {
265 	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
266 
267 	if (!ops->promisc_on_master)
268 		return;
269 
270 	rtnl_lock();
271 	dev_set_promiscuity(dev, inc);
272 	rtnl_unlock();
273 }
274 
275 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
276 			    char *buf)
277 {
278 	struct net_device *dev = to_net_dev(d);
279 	struct dsa_port *cpu_dp = dev->dsa_ptr;
280 
281 	return sprintf(buf, "%s\n",
282 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
283 }
284 
285 static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
286 			     const char *buf, size_t count)
287 {
288 	const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
289 	struct net_device *dev = to_net_dev(d);
290 	struct dsa_port *cpu_dp = dev->dsa_ptr;
291 	int err;
292 
293 	old_tag_ops = cpu_dp->tag_ops;
294 	new_tag_ops = dsa_find_tagger_by_name(buf);
295 	/* Bad tagger name, or module is not loaded? */
296 	if (IS_ERR(new_tag_ops))
297 		return PTR_ERR(new_tag_ops);
298 
299 	if (new_tag_ops == old_tag_ops)
300 		/* Drop the temporarily held duplicate reference, since
301 		 * the DSA switch tree uses this tagger.
302 		 */
303 		goto out;
304 
305 	err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, dev, new_tag_ops,
306 					old_tag_ops);
307 	if (err) {
308 		/* On failure the old tagger is restored, so we don't need the
309 		 * driver for the new one.
310 		 */
311 		dsa_tag_driver_put(new_tag_ops);
312 		return err;
313 	}
314 
315 	/* On success we no longer need the module for the old tagging protocol
316 	 */
317 out:
318 	dsa_tag_driver_put(old_tag_ops);
319 	return count;
320 }
321 static DEVICE_ATTR_RW(tagging);
322 
323 static struct attribute *dsa_slave_attrs[] = {
324 	&dev_attr_tagging.attr,
325 	NULL
326 };
327 
328 static const struct attribute_group dsa_group = {
329 	.name	= "dsa",
330 	.attrs	= dsa_slave_attrs,
331 };
332 
333 static void dsa_master_reset_mtu(struct net_device *dev)
334 {
335 	int err;
336 
337 	rtnl_lock();
338 	err = dev_set_mtu(dev, ETH_DATA_LEN);
339 	if (err)
340 		netdev_dbg(dev,
341 			   "Unable to reset MTU to exclude DSA overheads\n");
342 	rtnl_unlock();
343 }
344 
345 static struct lock_class_key dsa_master_addr_list_lock_key;
346 
347 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
348 {
349 	const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;
350 	struct dsa_switch *ds = cpu_dp->ds;
351 	struct device_link *consumer_link;
352 	int mtu, ret;
353 
354 	mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);
355 
356 	/* The DSA master must use SET_NETDEV_DEV for this to work. */
357 	consumer_link = device_link_add(ds->dev, dev->dev.parent,
358 					DL_FLAG_AUTOREMOVE_CONSUMER);
359 	if (!consumer_link)
360 		netdev_err(dev,
361 			   "Failed to create a device link to DSA switch %s\n",
362 			   dev_name(ds->dev));
363 
364 	rtnl_lock();
365 	ret = dev_set_mtu(dev, mtu);
366 	rtnl_unlock();
367 	if (ret)
368 		netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
369 			    ret, mtu);
370 
371 	/* If we use a tagging format that doesn't have an ethertype
372 	 * field, make sure that all packets from this point on get
373 	 * sent to the tag format's receive function.
374 	 */
375 	wmb();
376 
377 	dev->dsa_ptr = cpu_dp;
378 	lockdep_set_class(&dev->addr_list_lock,
379 			  &dsa_master_addr_list_lock_key);
380 
381 	dsa_master_set_promiscuity(dev, 1);
382 
383 	ret = dsa_master_ethtool_setup(dev);
384 	if (ret)
385 		goto out_err_reset_promisc;
386 
387 	dsa_netdev_ops_set(dev, &dsa_netdev_ops);
388 
389 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
390 	if (ret)
391 		goto out_err_ndo_teardown;
392 
393 	return ret;
394 
395 out_err_ndo_teardown:
396 	dsa_netdev_ops_set(dev, NULL);
397 	dsa_master_ethtool_teardown(dev);
398 out_err_reset_promisc:
399 	dsa_master_set_promiscuity(dev, -1);
400 	return ret;
401 }
402 
403 void dsa_master_teardown(struct net_device *dev)
404 {
405 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
406 	dsa_netdev_ops_set(dev, NULL);
407 	dsa_master_ethtool_teardown(dev);
408 	dsa_master_reset_mtu(dev);
409 	dsa_master_set_promiscuity(dev, -1);
410 
411 	dev->dsa_ptr = NULL;
412 
413 	/* If we used a tagging format that doesn't have an ethertype
414 	 * field, make sure that all packets from this point get sent
415 	 * without the tag and go through the regular receive path.
416 	 */
417 	wmb();
418 }
419