xref: /openbmc/linux/net/dsa/master.c (revision 82b5d164)
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_ethtool_setup(struct net_device *dev)
201 {
202 	struct dsa_port *cpu_dp = dev->dsa_ptr;
203 	struct dsa_switch *ds = cpu_dp->ds;
204 	struct ethtool_ops *ops;
205 
206 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
207 	if (!ops)
208 		return -ENOMEM;
209 
210 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
211 	if (cpu_dp->orig_ethtool_ops)
212 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
213 
214 	ops->get_regs_len = dsa_master_get_regs_len;
215 	ops->get_regs = dsa_master_get_regs;
216 	ops->get_sset_count = dsa_master_get_sset_count;
217 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
218 	ops->get_strings = dsa_master_get_strings;
219 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
220 
221 	dev->ethtool_ops = ops;
222 
223 	return 0;
224 }
225 
226 static void dsa_master_ethtool_teardown(struct net_device *dev)
227 {
228 	struct dsa_port *cpu_dp = dev->dsa_ptr;
229 
230 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
231 	cpu_dp->orig_ethtool_ops = NULL;
232 }
233 
234 static int dsa_master_ndo_setup(struct net_device *dev)
235 {
236 	struct dsa_port *cpu_dp = dev->dsa_ptr;
237 	struct dsa_switch *ds = cpu_dp->ds;
238 	struct net_device_ops *ops;
239 
240 	if (dev->netdev_ops->ndo_get_phys_port_name)
241 		return 0;
242 
243 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
244 	if (!ops)
245 		return -ENOMEM;
246 
247 	cpu_dp->orig_ndo_ops = dev->netdev_ops;
248 	if (cpu_dp->orig_ndo_ops)
249 		memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));
250 
251 	ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;
252 
253 	dev->netdev_ops  = ops;
254 
255 	return 0;
256 }
257 
258 static void dsa_master_ndo_teardown(struct net_device *dev)
259 {
260 	struct dsa_port *cpu_dp = dev->dsa_ptr;
261 
262 	dev->netdev_ops = cpu_dp->orig_ndo_ops;
263 	cpu_dp->orig_ndo_ops = NULL;
264 }
265 
266 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
267 			    char *buf)
268 {
269 	struct net_device *dev = to_net_dev(d);
270 	struct dsa_port *cpu_dp = dev->dsa_ptr;
271 
272 	return sprintf(buf, "%s\n",
273 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
274 }
275 static DEVICE_ATTR_RO(tagging);
276 
277 static struct attribute *dsa_slave_attrs[] = {
278 	&dev_attr_tagging.attr,
279 	NULL
280 };
281 
282 static const struct attribute_group dsa_group = {
283 	.name	= "dsa",
284 	.attrs	= dsa_slave_attrs,
285 };
286 
287 static void dsa_master_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp)
288 {
289 	unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
290 	int err;
291 
292 	rtnl_lock();
293 	if (mtu <= dev->max_mtu) {
294 		err = dev_set_mtu(dev, mtu);
295 		if (err)
296 			netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
297 	}
298 	rtnl_unlock();
299 }
300 
301 static void dsa_master_reset_mtu(struct net_device *dev)
302 {
303 	int err;
304 
305 	rtnl_lock();
306 	err = dev_set_mtu(dev, ETH_DATA_LEN);
307 	if (err)
308 		netdev_dbg(dev,
309 			   "Unable to reset MTU to exclude DSA overheads\n");
310 	rtnl_unlock();
311 }
312 
313 static struct lock_class_key dsa_master_addr_list_lock_key;
314 
315 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
316 {
317 	int ret;
318 
319 	dsa_master_set_mtu(dev,  cpu_dp);
320 
321 	/* If we use a tagging format that doesn't have an ethertype
322 	 * field, make sure that all packets from this point on get
323 	 * sent to the tag format's receive function.
324 	 */
325 	wmb();
326 
327 	dev->dsa_ptr = cpu_dp;
328 	lockdep_set_class(&dev->addr_list_lock,
329 			  &dsa_master_addr_list_lock_key);
330 
331 	ret = dsa_master_ethtool_setup(dev);
332 	if (ret)
333 		return ret;
334 
335 	ret = dsa_master_ndo_setup(dev);
336 	if (ret)
337 		goto out_err_ethtool_teardown;
338 
339 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
340 	if (ret)
341 		goto out_err_ndo_teardown;
342 
343 	return ret;
344 
345 out_err_ndo_teardown:
346 	dsa_master_ndo_teardown(dev);
347 out_err_ethtool_teardown:
348 	dsa_master_ethtool_teardown(dev);
349 	return ret;
350 }
351 
352 void dsa_master_teardown(struct net_device *dev)
353 {
354 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
355 	dsa_master_ndo_teardown(dev);
356 	dsa_master_ethtool_teardown(dev);
357 	dsa_master_reset_mtu(dev);
358 
359 	dev->dsa_ptr = NULL;
360 
361 	/* If we used a tagging format that doesn't have an ethertype
362 	 * field, make sure that all packets from this point get sent
363 	 * without the tag and go through the regular receive path.
364 	 */
365 	wmb();
366 }
367