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;
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
189static 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
218static const struct dsa_netdevice_ops dsa_netdev_ops = {
219	.ndo_do_ioctl = dsa_master_ioctl,
220};
221
222static 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
248static 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
256static 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
262static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
263			    char *buf)
264{
265	struct net_device *dev = to_net_dev(d);
266	struct dsa_port *cpu_dp = dev->dsa_ptr;
267
268	return sprintf(buf, "%s\n",
269		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
270}
271static DEVICE_ATTR_RO(tagging);
272
273static struct attribute *dsa_slave_attrs[] = {
274	&dev_attr_tagging.attr,
275	NULL
276};
277
278static const struct attribute_group dsa_group = {
279	.name	= "dsa",
280	.attrs	= dsa_slave_attrs,
281};
282
283static void dsa_master_reset_mtu(struct net_device *dev)
284{
285	int err;
286
287	rtnl_lock();
288	err = dev_set_mtu(dev, ETH_DATA_LEN);
289	if (err)
290		netdev_dbg(dev,
291			   "Unable to reset MTU to exclude DSA overheads\n");
292	rtnl_unlock();
293}
294
295static struct lock_class_key dsa_master_addr_list_lock_key;
296
297int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
298{
299	int ret;
300
301	rtnl_lock();
302	ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
303	rtnl_unlock();
304	if (ret)
305		netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
306			    ret);
307
308	/* If we use a tagging format that doesn't have an ethertype
309	 * field, make sure that all packets from this point on get
310	 * sent to the tag format's receive function.
311	 */
312	wmb();
313
314	dev->dsa_ptr = cpu_dp;
315	lockdep_set_class(&dev->addr_list_lock,
316			  &dsa_master_addr_list_lock_key);
317	ret = dsa_master_ethtool_setup(dev);
318	if (ret)
319		return ret;
320
321	dsa_netdev_ops_set(dev, &dsa_netdev_ops);
322
323	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
324	if (ret)
325		goto out_err_ndo_teardown;
326
327	return ret;
328
329out_err_ndo_teardown:
330	dsa_netdev_ops_set(dev, NULL);
331	dsa_master_ethtool_teardown(dev);
332	return ret;
333}
334
335void dsa_master_teardown(struct net_device *dev)
336{
337	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
338	dsa_netdev_ops_set(dev, NULL);
339	dsa_master_ethtool_teardown(dev);
340	dsa_master_reset_mtu(dev);
341
342	dev->dsa_ptr = NULL;
343
344	/* If we used a tagging format that doesn't have an ethertype
345	 * field, make sure that all packets from this point get sent
346	 * without the tag and go through the regular receive path.
347	 */
348	wmb();
349}