xref: /openbmc/linux/net/dsa/master.c (revision d9fd5a71)
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;
151 	unsigned int i;
152 	uint8_t pfx[4];
153 	uint8_t *ndata;
154 
155 	snprintf(pfx, sizeof(pfx), "p%.2d", port);
156 	/* We do not want to be NULL-terminated, since this is a prefix */
157 	pfx[sizeof(pfx) - 1] = '_';
158 
159 	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
160 	    !ops->get_ethtool_phy_stats) {
161 		mcount = phy_ethtool_get_sset_count(dev->phydev);
162 		if (mcount < 0)
163 			mcount = 0;
164 		else
165 			phy_ethtool_get_strings(dev->phydev, data);
166 	} else if (ops->get_sset_count && ops->get_strings) {
167 		mcount = ops->get_sset_count(dev, stringset);
168 		if (mcount < 0)
169 			mcount = 0;
170 		ops->get_strings(dev, stringset, data);
171 	}
172 
173 	if (ds->ops->get_strings) {
174 		ndata = data + mcount * len;
175 		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
176 		 * the output after to prepend our CPU port prefix we
177 		 * constructed earlier
178 		 */
179 		ds->ops->get_strings(ds, port, stringset, ndata);
180 		count = ds->ops->get_sset_count(ds, port, stringset);
181 		for (i = 0; i < count; i++) {
182 			memmove(ndata + (i * len + sizeof(pfx)),
183 				ndata + i * len, len - sizeof(pfx));
184 			memcpy(ndata + i * len, pfx, sizeof(pfx));
185 		}
186 	}
187 }
188 
189 static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
190 {
191 	struct dsa_port *cpu_dp = dev->dsa_ptr;
192 	struct dsa_switch *ds = cpu_dp->ds;
193 	struct dsa_switch_tree *dst;
194 	int err = -EOPNOTSUPP;
195 	struct dsa_port *dp;
196 
197 	dst = ds->dst;
198 
199 	switch (cmd) {
200 	case SIOCGHWTSTAMP:
201 	case SIOCSHWTSTAMP:
202 		/* Deny PTP operations on master if there is at least one
203 		 * switch in the tree that is PTP capable.
204 		 */
205 		list_for_each_entry(dp, &dst->ports, list)
206 			if (dp->ds->ops->port_hwtstamp_get ||
207 			    dp->ds->ops->port_hwtstamp_set)
208 				return -EBUSY;
209 		break;
210 	}
211 
212 	if (dev->netdev_ops->ndo_do_ioctl)
213 		err = dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
214 
215 	return err;
216 }
217 
218 static const struct dsa_netdevice_ops dsa_netdev_ops = {
219 	.ndo_do_ioctl = dsa_master_ioctl,
220 };
221 
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 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
229 	if (!ops)
230 		return -ENOMEM;
231 
232 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
233 	if (cpu_dp->orig_ethtool_ops)
234 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
235 
236 	ops->get_regs_len = dsa_master_get_regs_len;
237 	ops->get_regs = dsa_master_get_regs;
238 	ops->get_sset_count = dsa_master_get_sset_count;
239 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
240 	ops->get_strings = dsa_master_get_strings;
241 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
242 
243 	dev->ethtool_ops = ops;
244 
245 	return 0;
246 }
247 
248 static void dsa_master_ethtool_teardown(struct net_device *dev)
249 {
250 	struct dsa_port *cpu_dp = dev->dsa_ptr;
251 
252 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
253 	cpu_dp->orig_ethtool_ops = NULL;
254 }
255 
256 static void dsa_netdev_ops_set(struct net_device *dev,
257 			       const struct dsa_netdevice_ops *ops)
258 {
259 	dev->dsa_ptr->netdev_ops = ops;
260 }
261 
262 static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
263 {
264 	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
265 
266 	if (!ops->promisc_on_master)
267 		return;
268 
269 	rtnl_lock();
270 	dev_set_promiscuity(dev, inc);
271 	rtnl_unlock();
272 }
273 
274 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
275 			    char *buf)
276 {
277 	struct net_device *dev = to_net_dev(d);
278 	struct dsa_port *cpu_dp = dev->dsa_ptr;
279 
280 	return sprintf(buf, "%s\n",
281 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
282 }
283 
284 static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
285 			     const char *buf, size_t count)
286 {
287 	const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
288 	struct net_device *dev = to_net_dev(d);
289 	struct dsa_port *cpu_dp = dev->dsa_ptr;
290 	int err;
291 
292 	old_tag_ops = cpu_dp->tag_ops;
293 	new_tag_ops = dsa_find_tagger_by_name(buf);
294 	/* Bad tagger name, or module is not loaded? */
295 	if (IS_ERR(new_tag_ops))
296 		return PTR_ERR(new_tag_ops);
297 
298 	if (new_tag_ops == old_tag_ops)
299 		/* Drop the temporarily held duplicate reference, since
300 		 * the DSA switch tree uses this tagger.
301 		 */
302 		goto out;
303 
304 	err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, dev, new_tag_ops,
305 					old_tag_ops);
306 	if (err) {
307 		/* On failure the old tagger is restored, so we don't need the
308 		 * driver for the new one.
309 		 */
310 		dsa_tag_driver_put(new_tag_ops);
311 		return err;
312 	}
313 
314 	/* On success we no longer need the module for the old tagging protocol
315 	 */
316 out:
317 	dsa_tag_driver_put(old_tag_ops);
318 	return count;
319 }
320 static DEVICE_ATTR_RW(tagging);
321 
322 static struct attribute *dsa_slave_attrs[] = {
323 	&dev_attr_tagging.attr,
324 	NULL
325 };
326 
327 static const struct attribute_group dsa_group = {
328 	.name	= "dsa",
329 	.attrs	= dsa_slave_attrs,
330 };
331 
332 static void dsa_master_reset_mtu(struct net_device *dev)
333 {
334 	int err;
335 
336 	rtnl_lock();
337 	err = dev_set_mtu(dev, ETH_DATA_LEN);
338 	if (err)
339 		netdev_dbg(dev,
340 			   "Unable to reset MTU to exclude DSA overheads\n");
341 	rtnl_unlock();
342 }
343 
344 static struct lock_class_key dsa_master_addr_list_lock_key;
345 
346 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
347 {
348 	int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
349 	struct dsa_switch *ds = cpu_dp->ds;
350 	struct device_link *consumer_link;
351 	int ret;
352 
353 	/* The DSA master must use SET_NETDEV_DEV for this to work. */
354 	consumer_link = device_link_add(ds->dev, dev->dev.parent,
355 					DL_FLAG_AUTOREMOVE_CONSUMER);
356 	if (!consumer_link)
357 		netdev_err(dev,
358 			   "Failed to create a device link to DSA switch %s\n",
359 			   dev_name(ds->dev));
360 
361 	rtnl_lock();
362 	ret = dev_set_mtu(dev, mtu);
363 	rtnl_unlock();
364 	if (ret)
365 		netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
366 			    ret, mtu);
367 
368 	/* If we use a tagging format that doesn't have an ethertype
369 	 * field, make sure that all packets from this point on get
370 	 * sent to the tag format's receive function.
371 	 */
372 	wmb();
373 
374 	dev->dsa_ptr = cpu_dp;
375 	lockdep_set_class(&dev->addr_list_lock,
376 			  &dsa_master_addr_list_lock_key);
377 
378 	dsa_master_set_promiscuity(dev, 1);
379 
380 	ret = dsa_master_ethtool_setup(dev);
381 	if (ret)
382 		goto out_err_reset_promisc;
383 
384 	dsa_netdev_ops_set(dev, &dsa_netdev_ops);
385 
386 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
387 	if (ret)
388 		goto out_err_ndo_teardown;
389 
390 	return ret;
391 
392 out_err_ndo_teardown:
393 	dsa_netdev_ops_set(dev, NULL);
394 	dsa_master_ethtool_teardown(dev);
395 out_err_reset_promisc:
396 	dsa_master_set_promiscuity(dev, -1);
397 	return ret;
398 }
399 
400 void dsa_master_teardown(struct net_device *dev)
401 {
402 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
403 	dsa_netdev_ops_set(dev, NULL);
404 	dsa_master_ethtool_teardown(dev);
405 	dsa_master_reset_mtu(dev);
406 	dsa_master_set_promiscuity(dev, -1);
407 
408 	dev->dsa_ptr = NULL;
409 
410 	/* If we used a tagging format that doesn't have an ethertype
411 	 * field, make sure that all packets from this point get sent
412 	 * without the tag and go through the regular receive path.
413 	 */
414 	wmb();
415 }
416