xref: /kernel/linux/linux-5.10/net/dsa/master.c (revision 8c2ecf20)
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
11static 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
40static 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
75static 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
94static 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
120static 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
142static 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
190static 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_do_ioctl)
214		err = dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
215
216	return err;
217}
218
219static const struct dsa_netdevice_ops dsa_netdev_ops = {
220	.ndo_do_ioctl = dsa_master_ioctl,
221};
222
223static 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
249static 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
257static 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
263static 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
275static 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}
284static DEVICE_ATTR_RO(tagging);
285
286static struct attribute *dsa_slave_attrs[] = {
287	&dev_attr_tagging.attr,
288	NULL
289};
290
291static const struct attribute_group dsa_group = {
292	.name	= "dsa",
293	.attrs	= dsa_slave_attrs,
294};
295
296static void dsa_master_reset_mtu(struct net_device *dev)
297{
298	int err;
299
300	rtnl_lock();
301	err = dev_set_mtu(dev, ETH_DATA_LEN);
302	if (err)
303		netdev_dbg(dev,
304			   "Unable to reset MTU to exclude DSA overheads\n");
305	rtnl_unlock();
306}
307
308static struct lock_class_key dsa_master_addr_list_lock_key;
309
310int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
311{
312	struct dsa_switch *ds = cpu_dp->ds;
313	struct device_link *consumer_link;
314	int ret;
315
316	/* The DSA master must use SET_NETDEV_DEV for this to work. */
317	consumer_link = device_link_add(ds->dev, dev->dev.parent,
318					DL_FLAG_AUTOREMOVE_CONSUMER);
319	if (!consumer_link)
320		netdev_err(dev,
321			   "Failed to create a device link to DSA switch %s\n",
322			   dev_name(ds->dev));
323
324	rtnl_lock();
325	ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
326	rtnl_unlock();
327	if (ret)
328		netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
329			    ret);
330
331	/* If we use a tagging format that doesn't have an ethertype
332	 * field, make sure that all packets from this point on get
333	 * sent to the tag format's receive function.
334	 */
335	wmb();
336
337	dev->dsa_ptr = cpu_dp;
338	lockdep_set_class(&dev->addr_list_lock,
339			  &dsa_master_addr_list_lock_key);
340
341	dsa_master_set_promiscuity(dev, 1);
342
343	ret = dsa_master_ethtool_setup(dev);
344	if (ret)
345		goto out_err_reset_promisc;
346
347	dsa_netdev_ops_set(dev, &dsa_netdev_ops);
348
349	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
350	if (ret)
351		goto out_err_ndo_teardown;
352
353	return ret;
354
355out_err_ndo_teardown:
356	dsa_netdev_ops_set(dev, NULL);
357	dsa_master_ethtool_teardown(dev);
358out_err_reset_promisc:
359	dsa_master_set_promiscuity(dev, -1);
360	return ret;
361}
362
363void dsa_master_teardown(struct net_device *dev)
364{
365	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
366	dsa_netdev_ops_set(dev, NULL);
367	dsa_master_ethtool_teardown(dev);
368	dsa_master_reset_mtu(dev);
369	dsa_master_set_promiscuity(dev, -1);
370
371	dev->dsa_ptr = NULL;
372
373	/* If we used a tagging format that doesn't have an ethertype
374	 * field, make sure that all packets from this point get sent
375	 * without the tag and go through the regular receive path.
376	 */
377	wmb();
378}
379