xref: /openbmc/linux/net/dsa/master.c (revision e6e8c82b)
1 /*
2  * Handling of a master device, switching frames via its switch fabric CPU port
3  *
4  * Copyright (c) 2017 Savoir-faire Linux Inc.
5  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  */
12 
13 #include "dsa_priv.h"
14 
15 static void dsa_master_get_ethtool_stats(struct net_device *dev,
16 					 struct ethtool_stats *stats,
17 					 uint64_t *data)
18 {
19 	struct dsa_port *cpu_dp = dev->dsa_ptr;
20 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
21 	struct dsa_switch *ds = cpu_dp->ds;
22 	int port = cpu_dp->index;
23 	int count = 0;
24 
25 	if (ops->get_sset_count && ops->get_ethtool_stats) {
26 		count = ops->get_sset_count(dev, ETH_SS_STATS);
27 		ops->get_ethtool_stats(dev, stats, data);
28 	}
29 
30 	if (ds->ops->get_ethtool_stats)
31 		ds->ops->get_ethtool_stats(ds, port, data + count);
32 }
33 
34 static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
35 					     struct ethtool_stats *stats,
36 					     uint64_t *data)
37 {
38 	struct dsa_port *cpu_dp = dev->dsa_ptr;
39 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
40 	struct dsa_switch *ds = cpu_dp->ds;
41 	int port = cpu_dp->index;
42 	int count = 0;
43 
44 	if (dev->phydev && !ops->get_ethtool_phy_stats) {
45 		count = phy_ethtool_get_sset_count(dev->phydev);
46 		if (count >= 0)
47 			phy_ethtool_get_stats(dev->phydev, stats, data);
48 	} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
49 		count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
50 		ops->get_ethtool_phy_stats(dev, stats, data);
51 	}
52 
53 	if (count < 0)
54 		count = 0;
55 
56 	if (ds->ops->get_ethtool_phy_stats)
57 		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
58 }
59 
60 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
61 {
62 	struct dsa_port *cpu_dp = dev->dsa_ptr;
63 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
64 	struct dsa_switch *ds = cpu_dp->ds;
65 	int count = 0;
66 
67 	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
68 	    !ops->get_ethtool_phy_stats)
69 		count = phy_ethtool_get_sset_count(dev->phydev);
70 	else if (ops->get_sset_count)
71 		count = ops->get_sset_count(dev, sset);
72 
73 	if (count < 0)
74 		count = 0;
75 
76 	if (ds->ops->get_sset_count)
77 		count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
78 
79 	return count;
80 }
81 
82 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
83 				   uint8_t *data)
84 {
85 	struct dsa_port *cpu_dp = dev->dsa_ptr;
86 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
87 	struct dsa_switch *ds = cpu_dp->ds;
88 	int port = cpu_dp->index;
89 	int len = ETH_GSTRING_LEN;
90 	int mcount = 0, count;
91 	unsigned int i;
92 	uint8_t pfx[4];
93 	uint8_t *ndata;
94 
95 	snprintf(pfx, sizeof(pfx), "p%.2d", port);
96 	/* We do not want to be NULL-terminated, since this is a prefix */
97 	pfx[sizeof(pfx) - 1] = '_';
98 
99 	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
100 	    !ops->get_ethtool_phy_stats) {
101 		mcount = phy_ethtool_get_sset_count(dev->phydev);
102 		if (mcount < 0)
103 			mcount = 0;
104 		else
105 			phy_ethtool_get_strings(dev->phydev, data);
106 	} else if (ops->get_sset_count && ops->get_strings) {
107 		mcount = ops->get_sset_count(dev, stringset);
108 		if (mcount < 0)
109 			mcount = 0;
110 		ops->get_strings(dev, stringset, data);
111 	}
112 
113 	if (ds->ops->get_strings) {
114 		ndata = data + mcount * len;
115 		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
116 		 * the output after to prepend our CPU port prefix we
117 		 * constructed earlier
118 		 */
119 		ds->ops->get_strings(ds, port, stringset, ndata);
120 		count = ds->ops->get_sset_count(ds, port, stringset);
121 		for (i = 0; i < count; i++) {
122 			memmove(ndata + (i * len + sizeof(pfx)),
123 				ndata + i * len, len - sizeof(pfx));
124 			memcpy(ndata + i * len, pfx, sizeof(pfx));
125 		}
126 	}
127 }
128 
129 static int dsa_master_ethtool_setup(struct net_device *dev)
130 {
131 	struct dsa_port *cpu_dp = dev->dsa_ptr;
132 	struct dsa_switch *ds = cpu_dp->ds;
133 	struct ethtool_ops *ops;
134 
135 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
136 	if (!ops)
137 		return -ENOMEM;
138 
139 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
140 	if (cpu_dp->orig_ethtool_ops)
141 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
142 
143 	ops->get_sset_count = dsa_master_get_sset_count;
144 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
145 	ops->get_strings = dsa_master_get_strings;
146 	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
147 
148 	dev->ethtool_ops = ops;
149 
150 	return 0;
151 }
152 
153 static void dsa_master_ethtool_teardown(struct net_device *dev)
154 {
155 	struct dsa_port *cpu_dp = dev->dsa_ptr;
156 
157 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
158 	cpu_dp->orig_ethtool_ops = NULL;
159 }
160 
161 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
162 			    char *buf)
163 {
164 	struct net_device *dev = to_net_dev(d);
165 	struct dsa_port *cpu_dp = dev->dsa_ptr;
166 
167 	return sprintf(buf, "%s\n",
168 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
169 }
170 static DEVICE_ATTR_RO(tagging);
171 
172 static struct attribute *dsa_slave_attrs[] = {
173 	&dev_attr_tagging.attr,
174 	NULL
175 };
176 
177 static const struct attribute_group dsa_group = {
178 	.name	= "dsa",
179 	.attrs	= dsa_slave_attrs,
180 };
181 
182 static void dsa_master_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp)
183 {
184 	unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
185 	int err;
186 
187 	rtnl_lock();
188 	if (mtu <= dev->max_mtu) {
189 		err = dev_set_mtu(dev, mtu);
190 		if (err)
191 			netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
192 	}
193 	rtnl_unlock();
194 }
195 
196 static void dsa_master_reset_mtu(struct net_device *dev)
197 {
198 	int err;
199 
200 	rtnl_lock();
201 	err = dev_set_mtu(dev, ETH_DATA_LEN);
202 	if (err)
203 		netdev_dbg(dev,
204 			   "Unable to reset MTU to exclude DSA overheads\n");
205 	rtnl_unlock();
206 }
207 
208 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
209 {
210 	int ret;
211 
212 	dsa_master_set_mtu(dev,  cpu_dp);
213 
214 	/* If we use a tagging format that doesn't have an ethertype
215 	 * field, make sure that all packets from this point on get
216 	 * sent to the tag format's receive function.
217 	 */
218 	wmb();
219 
220 	dev->dsa_ptr = cpu_dp;
221 
222 	ret = dsa_master_ethtool_setup(dev);
223 	if (ret)
224 		return ret;
225 
226 	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
227 	if (ret)
228 		dsa_master_ethtool_teardown(dev);
229 
230 	return ret;
231 }
232 
233 void dsa_master_teardown(struct net_device *dev)
234 {
235 	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
236 	dsa_master_ethtool_teardown(dev);
237 	dsa_master_reset_mtu(dev);
238 
239 	dev->dsa_ptr = NULL;
240 
241 	/* If we used a tagging format that doesn't have an ethertype
242 	 * field, make sure that all packets from this point get sent
243 	 * without the tag and go through the regular receive path.
244 	 */
245 	wmb();
246 }
247