xref: /openbmc/linux/net/dsa/master.c (revision 3dc167ba)
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_get_phys_port_name(struct net_device *dev,
190 					 char *name, size_t len)
191 {
192 	struct dsa_port *cpu_dp = dev->dsa_ptr;
193 
194 	if (snprintf(name, len, "p%d", cpu_dp->index) >= len)
195 		return -EINVAL;
196 
197 	return 0;
198 }
199 
200 static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
201 {
202 	struct dsa_port *cpu_dp = dev->dsa_ptr;
203 	struct dsa_switch *ds = cpu_dp->ds;
204 	struct dsa_switch_tree *dst;
205 	int err = -EOPNOTSUPP;
206 	struct dsa_port *dp;
207 
208 	dst = ds->dst;
209 
210 	switch (cmd) {
211 	case SIOCGHWTSTAMP:
212 	case SIOCSHWTSTAMP:
213 		/* Deny PTP operations on master if there is at least one
214 		 * switch in the tree that is PTP capable.
215 		 */
216 		list_for_each_entry(dp, &dst->ports, list)
217 			if (dp->ds->ops->port_hwtstamp_get ||
218 			    dp->ds->ops->port_hwtstamp_set)
219 				return -EBUSY;
220 		break;
221 	}
222 
223 	if (cpu_dp->orig_ndo_ops && cpu_dp->orig_ndo_ops->ndo_do_ioctl)
224 		err = cpu_dp->orig_ndo_ops->ndo_do_ioctl(dev, ifr, cmd);
225 
226 	return err;
227 }
228 
229 static int dsa_master_ethtool_setup(struct net_device *dev)
230 {
231 	struct dsa_port *cpu_dp = dev->dsa_ptr;
232 	struct dsa_switch *ds = cpu_dp->ds;
233 	struct ethtool_ops *ops;
234 
235 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
236 	if (!ops)
237 		return -ENOMEM;
238 
239 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
240 	if (cpu_dp->orig_ethtool_ops)
241 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
242 
243 	ops->get_regs_len = dsa_master_get_regs_len;
244 	ops->get_regs = dsa_master_get_regs;
245 	ops->get_sset_count = dsa_master_get_sset_count;
246 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
247 	ops->get_strings = dsa_master_get_strings;
248 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
249 
250 	dev->ethtool_ops = ops;
251 
252 	return 0;
253 }
254 
255 static void dsa_master_ethtool_teardown(struct net_device *dev)
256 {
257 	struct dsa_port *cpu_dp = dev->dsa_ptr;
258 
259 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
260 	cpu_dp->orig_ethtool_ops = NULL;
261 }
262 
263 static int dsa_master_ndo_setup(struct net_device *dev)
264 {
265 	struct dsa_port *cpu_dp = dev->dsa_ptr;
266 	struct dsa_switch *ds = cpu_dp->ds;
267 	struct net_device_ops *ops;
268 
269 	if (dev->netdev_ops->ndo_get_phys_port_name)
270 		return 0;
271 
272 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
273 	if (!ops)
274 		return -ENOMEM;
275 
276 	cpu_dp->orig_ndo_ops = dev->netdev_ops;
277 	if (cpu_dp->orig_ndo_ops)
278 		memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));
279 
280 	ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;
281 	ops->ndo_do_ioctl = dsa_master_ioctl;
282 
283 	dev->netdev_ops  = ops;
284 
285 	return 0;
286 }
287 
288 static void dsa_master_ndo_teardown(struct net_device *dev)
289 {
290 	struct dsa_port *cpu_dp = dev->dsa_ptr;
291 
292 	if (cpu_dp->orig_ndo_ops)
293 		dev->netdev_ops = cpu_dp->orig_ndo_ops;
294 	cpu_dp->orig_ndo_ops = NULL;
295 }
296 
297 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
298 			    char *buf)
299 {
300 	struct net_device *dev = to_net_dev(d);
301 	struct dsa_port *cpu_dp = dev->dsa_ptr;
302 
303 	return sprintf(buf, "%s\n",
304 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
305 }
306 static DEVICE_ATTR_RO(tagging);
307 
308 static struct attribute *dsa_slave_attrs[] = {
309 	&dev_attr_tagging.attr,
310 	NULL
311 };
312 
313 static const struct attribute_group dsa_group = {
314 	.name	= "dsa",
315 	.attrs	= dsa_slave_attrs,
316 };
317 
318 static void dsa_master_reset_mtu(struct net_device *dev)
319 {
320 	int err;
321 
322 	rtnl_lock();
323 	err = dev_set_mtu(dev, ETH_DATA_LEN);
324 	if (err)
325 		netdev_dbg(dev,
326 			   "Unable to reset MTU to exclude DSA overheads\n");
327 	rtnl_unlock();
328 }
329 
330 static struct lock_class_key dsa_master_addr_list_lock_key;
331 
332 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
333 {
334 	int ret;
335 
336 	rtnl_lock();
337 	ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
338 	rtnl_unlock();
339 	if (ret)
340 		netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
341 			    ret);
342 
343 	/* If we use a tagging format that doesn't have an ethertype
344 	 * field, make sure that all packets from this point on get
345 	 * sent to the tag format's receive function.
346 	 */
347 	wmb();
348 
349 	dev->dsa_ptr = cpu_dp;
350 	lockdep_set_class(&dev->addr_list_lock,
351 			  &dsa_master_addr_list_lock_key);
352 	ret = dsa_master_ethtool_setup(dev);
353 	if (ret)
354 		return ret;
355 
356 	ret = dsa_master_ndo_setup(dev);
357 	if (ret)
358 		goto out_err_ethtool_teardown;
359 
360 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
361 	if (ret)
362 		goto out_err_ndo_teardown;
363 
364 	return ret;
365 
366 out_err_ndo_teardown:
367 	dsa_master_ndo_teardown(dev);
368 out_err_ethtool_teardown:
369 	dsa_master_ethtool_teardown(dev);
370 	return ret;
371 }
372 
373 void dsa_master_teardown(struct net_device *dev)
374 {
375 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
376 	dsa_master_ndo_teardown(dev);
377 	dsa_master_ethtool_teardown(dev);
378 	dsa_master_reset_mtu(dev);
379 
380 	dev->dsa_ptr = NULL;
381 
382 	/* If we used a tagging format that doesn't have an ethertype
383 	 * field, make sure that all packets from this point get sent
384 	 * without the tag and go through the regular receive path.
385 	 */
386 	wmb();
387 }
388