xref: /openbmc/linux/net/dsa/master.c (revision b830f94f)
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 void dsa_master_get_ethtool_stats(struct net_device *dev,
12 					 struct ethtool_stats *stats,
13 					 uint64_t *data)
14 {
15 	struct dsa_port *cpu_dp = dev->dsa_ptr;
16 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
17 	struct dsa_switch *ds = cpu_dp->ds;
18 	int port = cpu_dp->index;
19 	int count = 0;
20 
21 	if (ops->get_sset_count && ops->get_ethtool_stats) {
22 		count = ops->get_sset_count(dev, ETH_SS_STATS);
23 		ops->get_ethtool_stats(dev, stats, data);
24 	}
25 
26 	if (ds->ops->get_ethtool_stats)
27 		ds->ops->get_ethtool_stats(ds, port, data + count);
28 }
29 
30 static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
31 					     struct ethtool_stats *stats,
32 					     uint64_t *data)
33 {
34 	struct dsa_port *cpu_dp = dev->dsa_ptr;
35 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
36 	struct dsa_switch *ds = cpu_dp->ds;
37 	int port = cpu_dp->index;
38 	int count = 0;
39 
40 	if (dev->phydev && !ops->get_ethtool_phy_stats) {
41 		count = phy_ethtool_get_sset_count(dev->phydev);
42 		if (count >= 0)
43 			phy_ethtool_get_stats(dev->phydev, stats, data);
44 	} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
45 		count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
46 		ops->get_ethtool_phy_stats(dev, stats, data);
47 	}
48 
49 	if (count < 0)
50 		count = 0;
51 
52 	if (ds->ops->get_ethtool_phy_stats)
53 		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
54 }
55 
56 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
57 {
58 	struct dsa_port *cpu_dp = dev->dsa_ptr;
59 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
60 	struct dsa_switch *ds = cpu_dp->ds;
61 	int count = 0;
62 
63 	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
64 	    !ops->get_ethtool_phy_stats)
65 		count = phy_ethtool_get_sset_count(dev->phydev);
66 	else if (ops->get_sset_count)
67 		count = ops->get_sset_count(dev, sset);
68 
69 	if (count < 0)
70 		count = 0;
71 
72 	if (ds->ops->get_sset_count)
73 		count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
74 
75 	return count;
76 }
77 
78 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
79 				   uint8_t *data)
80 {
81 	struct dsa_port *cpu_dp = dev->dsa_ptr;
82 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
83 	struct dsa_switch *ds = cpu_dp->ds;
84 	int port = cpu_dp->index;
85 	int len = ETH_GSTRING_LEN;
86 	int mcount = 0, count;
87 	unsigned int i;
88 	uint8_t pfx[4];
89 	uint8_t *ndata;
90 
91 	snprintf(pfx, sizeof(pfx), "p%.2d", port);
92 	/* We do not want to be NULL-terminated, since this is a prefix */
93 	pfx[sizeof(pfx) - 1] = '_';
94 
95 	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
96 	    !ops->get_ethtool_phy_stats) {
97 		mcount = phy_ethtool_get_sset_count(dev->phydev);
98 		if (mcount < 0)
99 			mcount = 0;
100 		else
101 			phy_ethtool_get_strings(dev->phydev, data);
102 	} else if (ops->get_sset_count && ops->get_strings) {
103 		mcount = ops->get_sset_count(dev, stringset);
104 		if (mcount < 0)
105 			mcount = 0;
106 		ops->get_strings(dev, stringset, data);
107 	}
108 
109 	if (ds->ops->get_strings) {
110 		ndata = data + mcount * len;
111 		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
112 		 * the output after to prepend our CPU port prefix we
113 		 * constructed earlier
114 		 */
115 		ds->ops->get_strings(ds, port, stringset, ndata);
116 		count = ds->ops->get_sset_count(ds, port, stringset);
117 		for (i = 0; i < count; i++) {
118 			memmove(ndata + (i * len + sizeof(pfx)),
119 				ndata + i * len, len - sizeof(pfx));
120 			memcpy(ndata + i * len, pfx, sizeof(pfx));
121 		}
122 	}
123 }
124 
125 static int dsa_master_get_phys_port_name(struct net_device *dev,
126 					 char *name, size_t len)
127 {
128 	struct dsa_port *cpu_dp = dev->dsa_ptr;
129 
130 	if (snprintf(name, len, "p%d", cpu_dp->index) >= len)
131 		return -EINVAL;
132 
133 	return 0;
134 }
135 
136 static int dsa_master_ethtool_setup(struct net_device *dev)
137 {
138 	struct dsa_port *cpu_dp = dev->dsa_ptr;
139 	struct dsa_switch *ds = cpu_dp->ds;
140 	struct ethtool_ops *ops;
141 
142 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
143 	if (!ops)
144 		return -ENOMEM;
145 
146 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
147 	if (cpu_dp->orig_ethtool_ops)
148 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
149 
150 	ops->get_sset_count = dsa_master_get_sset_count;
151 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
152 	ops->get_strings = dsa_master_get_strings;
153 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
154 
155 	dev->ethtool_ops = ops;
156 
157 	return 0;
158 }
159 
160 static void dsa_master_ethtool_teardown(struct net_device *dev)
161 {
162 	struct dsa_port *cpu_dp = dev->dsa_ptr;
163 
164 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
165 	cpu_dp->orig_ethtool_ops = NULL;
166 }
167 
168 static int dsa_master_ndo_setup(struct net_device *dev)
169 {
170 	struct dsa_port *cpu_dp = dev->dsa_ptr;
171 	struct dsa_switch *ds = cpu_dp->ds;
172 	struct net_device_ops *ops;
173 
174 	if (dev->netdev_ops->ndo_get_phys_port_name)
175 		return 0;
176 
177 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
178 	if (!ops)
179 		return -ENOMEM;
180 
181 	cpu_dp->orig_ndo_ops = dev->netdev_ops;
182 	if (cpu_dp->orig_ndo_ops)
183 		memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));
184 
185 	ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;
186 
187 	dev->netdev_ops  = ops;
188 
189 	return 0;
190 }
191 
192 static void dsa_master_ndo_teardown(struct net_device *dev)
193 {
194 	struct dsa_port *cpu_dp = dev->dsa_ptr;
195 
196 	dev->netdev_ops = cpu_dp->orig_ndo_ops;
197 	cpu_dp->orig_ndo_ops = NULL;
198 }
199 
200 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
201 			    char *buf)
202 {
203 	struct net_device *dev = to_net_dev(d);
204 	struct dsa_port *cpu_dp = dev->dsa_ptr;
205 
206 	return sprintf(buf, "%s\n",
207 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
208 }
209 static DEVICE_ATTR_RO(tagging);
210 
211 static struct attribute *dsa_slave_attrs[] = {
212 	&dev_attr_tagging.attr,
213 	NULL
214 };
215 
216 static const struct attribute_group dsa_group = {
217 	.name	= "dsa",
218 	.attrs	= dsa_slave_attrs,
219 };
220 
221 static void dsa_master_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp)
222 {
223 	unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
224 	int err;
225 
226 	rtnl_lock();
227 	if (mtu <= dev->max_mtu) {
228 		err = dev_set_mtu(dev, mtu);
229 		if (err)
230 			netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
231 	}
232 	rtnl_unlock();
233 }
234 
235 static void dsa_master_reset_mtu(struct net_device *dev)
236 {
237 	int err;
238 
239 	rtnl_lock();
240 	err = dev_set_mtu(dev, ETH_DATA_LEN);
241 	if (err)
242 		netdev_dbg(dev,
243 			   "Unable to reset MTU to exclude DSA overheads\n");
244 	rtnl_unlock();
245 }
246 
247 static struct lock_class_key dsa_master_addr_list_lock_key;
248 
249 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
250 {
251 	int ret;
252 
253 	dsa_master_set_mtu(dev,  cpu_dp);
254 
255 	/* If we use a tagging format that doesn't have an ethertype
256 	 * field, make sure that all packets from this point on get
257 	 * sent to the tag format's receive function.
258 	 */
259 	wmb();
260 
261 	dev->dsa_ptr = cpu_dp;
262 	lockdep_set_class(&dev->addr_list_lock,
263 			  &dsa_master_addr_list_lock_key);
264 
265 	ret = dsa_master_ethtool_setup(dev);
266 	if (ret)
267 		return ret;
268 
269 	ret = dsa_master_ndo_setup(dev);
270 	if (ret)
271 		goto out_err_ethtool_teardown;
272 
273 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
274 	if (ret)
275 		goto out_err_ndo_teardown;
276 
277 	return ret;
278 
279 out_err_ndo_teardown:
280 	dsa_master_ndo_teardown(dev);
281 out_err_ethtool_teardown:
282 	dsa_master_ethtool_teardown(dev);
283 	return ret;
284 }
285 
286 void dsa_master_teardown(struct net_device *dev)
287 {
288 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
289 	dsa_master_ndo_teardown(dev);
290 	dsa_master_ethtool_teardown(dev);
291 	dsa_master_reset_mtu(dev);
292 
293 	dev->dsa_ptr = NULL;
294 
295 	/* If we used a tagging format that doesn't have an ethertype
296 	 * field, make sure that all packets from this point get sent
297 	 * without the tag and go through the regular receive path.
298 	 */
299 	wmb();
300 }
301