1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/dsa/dsa.c - Hardware switch handling
4 * Copyright (c) 2008-2009 Marvell Semiconductor
5 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
6 */
7
8 #include <linux/device.h>
9 #include <linux/list.h>
10 #include <linux/platform_device.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/notifier.h>
14 #include <linux/of.h>
15 #include <linux/of_mdio.h>
16 #include <linux/of_platform.h>
17 #include <linux/of_net.h>
18 #include <linux/netdevice.h>
19 #include <linux/sysfs.h>
20 #include <linux/phy_fixed.h>
21 #include <linux/ptp_classify.h>
22 #include <linux/etherdevice.h>
23
24 #include "dsa_priv.h"
25
26 static LIST_HEAD(dsa_tag_drivers_list);
27 static DEFINE_MUTEX(dsa_tag_drivers_lock);
28
dsa_slave_notag_xmit(struct sk_buff * skb,struct net_device * dev)29 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
30 struct net_device *dev)
31 {
32 /* Just return the original SKB */
33 return skb;
34 }
35
36 static const struct dsa_device_ops none_ops = {
37 .name = "none",
38 .proto = DSA_TAG_PROTO_NONE,
39 .xmit = dsa_slave_notag_xmit,
40 .rcv = NULL,
41 };
42
43 DSA_TAG_DRIVER(none_ops);
44
dsa_tag_driver_register(struct dsa_tag_driver * dsa_tag_driver,struct module * owner)45 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
46 struct module *owner)
47 {
48 dsa_tag_driver->owner = owner;
49
50 mutex_lock(&dsa_tag_drivers_lock);
51 list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
52 mutex_unlock(&dsa_tag_drivers_lock);
53 }
54
dsa_tag_drivers_register(struct dsa_tag_driver * dsa_tag_driver_array[],unsigned int count,struct module * owner)55 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
56 unsigned int count, struct module *owner)
57 {
58 unsigned int i;
59
60 for (i = 0; i < count; i++)
61 dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
62 }
63
dsa_tag_driver_unregister(struct dsa_tag_driver * dsa_tag_driver)64 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
65 {
66 mutex_lock(&dsa_tag_drivers_lock);
67 list_del(&dsa_tag_driver->list);
68 mutex_unlock(&dsa_tag_drivers_lock);
69 }
70 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
71
dsa_tag_drivers_unregister(struct dsa_tag_driver * dsa_tag_driver_array[],unsigned int count)72 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
73 unsigned int count)
74 {
75 unsigned int i;
76
77 for (i = 0; i < count; i++)
78 dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
79 }
80 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
81
dsa_tag_protocol_to_str(const struct dsa_device_ops * ops)82 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
83 {
84 return ops->name;
85 };
86
dsa_tag_driver_get(int tag_protocol)87 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
88 {
89 struct dsa_tag_driver *dsa_tag_driver;
90 const struct dsa_device_ops *ops;
91 char module_name[128];
92 bool found = false;
93
94 snprintf(module_name, 127, "%s%d", DSA_TAG_DRIVER_ALIAS,
95 tag_protocol);
96
97 request_module(module_name);
98
99 mutex_lock(&dsa_tag_drivers_lock);
100 list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
101 ops = dsa_tag_driver->ops;
102 if (ops->proto == tag_protocol) {
103 found = true;
104 break;
105 }
106 }
107
108 if (found) {
109 if (!try_module_get(dsa_tag_driver->owner))
110 ops = ERR_PTR(-ENOPROTOOPT);
111 } else {
112 ops = ERR_PTR(-ENOPROTOOPT);
113 }
114
115 mutex_unlock(&dsa_tag_drivers_lock);
116
117 return ops;
118 }
119
dsa_tag_driver_put(const struct dsa_device_ops * ops)120 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
121 {
122 struct dsa_tag_driver *dsa_tag_driver;
123
124 mutex_lock(&dsa_tag_drivers_lock);
125 list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
126 if (dsa_tag_driver->ops == ops) {
127 module_put(dsa_tag_driver->owner);
128 break;
129 }
130 }
131 mutex_unlock(&dsa_tag_drivers_lock);
132 }
133
dev_is_class(struct device * dev,void * class)134 static int dev_is_class(struct device *dev, void *class)
135 {
136 if (dev->class != NULL && !strcmp(dev->class->name, class))
137 return 1;
138
139 return 0;
140 }
141
dev_find_class(struct device * parent,char * class)142 static struct device *dev_find_class(struct device *parent, char *class)
143 {
144 if (dev_is_class(parent, class)) {
145 get_device(parent);
146 return parent;
147 }
148
149 return device_find_child(parent, class, dev_is_class);
150 }
151
dsa_dev_to_net_device(struct device * dev)152 struct net_device *dsa_dev_to_net_device(struct device *dev)
153 {
154 struct device *d;
155
156 d = dev_find_class(dev, "net");
157 if (d != NULL) {
158 struct net_device *nd;
159
160 nd = to_net_dev(d);
161 dev_hold(nd);
162 put_device(d);
163
164 return nd;
165 }
166
167 return NULL;
168 }
169 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
170
171 /* Determine if we should defer delivery of skb until we have a rx timestamp.
172 *
173 * Called from dsa_switch_rcv. For now, this will only work if tagging is
174 * enabled on the switch. Normally the MAC driver would retrieve the hardware
175 * timestamp when it reads the packet out of the hardware. However in a DSA
176 * switch, the DSA driver owning the interface to which the packet is
177 * delivered is never notified unless we do so here.
178 */
dsa_skb_defer_rx_timestamp(struct dsa_slave_priv * p,struct sk_buff * skb)179 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
180 struct sk_buff *skb)
181 {
182 struct dsa_switch *ds = p->dp->ds;
183 unsigned int type;
184
185 if (skb_headroom(skb) < ETH_HLEN)
186 return false;
187
188 __skb_push(skb, ETH_HLEN);
189
190 type = ptp_classify_raw(skb);
191
192 __skb_pull(skb, ETH_HLEN);
193
194 if (type == PTP_CLASS_NONE)
195 return false;
196
197 if (likely(ds->ops->port_rxtstamp))
198 return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
199
200 return false;
201 }
202
dsa_switch_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * unused)203 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
204 struct packet_type *pt, struct net_device *unused)
205 {
206 struct dsa_port *cpu_dp = dev->dsa_ptr;
207 struct sk_buff *nskb = NULL;
208 struct pcpu_sw_netstats *s;
209 struct dsa_slave_priv *p;
210
211 if (unlikely(!cpu_dp)) {
212 kfree_skb(skb);
213 return 0;
214 }
215
216 skb = skb_unshare(skb, GFP_ATOMIC);
217 if (!skb)
218 return 0;
219
220 nskb = cpu_dp->rcv(skb, dev, pt);
221 if (!nskb) {
222 kfree_skb(skb);
223 return 0;
224 }
225
226 skb = nskb;
227 p = netdev_priv(skb->dev);
228 skb_push(skb, ETH_HLEN);
229 skb->pkt_type = PACKET_HOST;
230 skb->protocol = eth_type_trans(skb, skb->dev);
231
232 s = this_cpu_ptr(p->stats64);
233 u64_stats_update_begin(&s->syncp);
234 s->rx_packets++;
235 s->rx_bytes += skb->len;
236 u64_stats_update_end(&s->syncp);
237
238 if (dsa_skb_defer_rx_timestamp(p, skb))
239 return 0;
240
241 netif_receive_skb(skb);
242
243 return 0;
244 }
245
246 #ifdef CONFIG_PM_SLEEP
dsa_is_port_initialized(struct dsa_switch * ds,int p)247 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
248 {
249 return dsa_is_user_port(ds, p) && ds->ports[p].slave;
250 }
251
dsa_switch_suspend(struct dsa_switch * ds)252 int dsa_switch_suspend(struct dsa_switch *ds)
253 {
254 int i, ret = 0;
255
256 /* Suspend slave network devices */
257 for (i = 0; i < ds->num_ports; i++) {
258 if (!dsa_is_port_initialized(ds, i))
259 continue;
260
261 ret = dsa_slave_suspend(ds->ports[i].slave);
262 if (ret)
263 return ret;
264 }
265
266 if (ds->ops->suspend)
267 ret = ds->ops->suspend(ds);
268
269 return ret;
270 }
271 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
272
dsa_switch_resume(struct dsa_switch * ds)273 int dsa_switch_resume(struct dsa_switch *ds)
274 {
275 int i, ret = 0;
276
277 if (ds->ops->resume)
278 ret = ds->ops->resume(ds);
279
280 if (ret)
281 return ret;
282
283 /* Resume slave network devices */
284 for (i = 0; i < ds->num_ports; i++) {
285 if (!dsa_is_port_initialized(ds, i))
286 continue;
287
288 ret = dsa_slave_resume(ds->ports[i].slave);
289 if (ret)
290 return ret;
291 }
292
293 return 0;
294 }
295 EXPORT_SYMBOL_GPL(dsa_switch_resume);
296 #endif
297
298 static struct packet_type dsa_pack_type __read_mostly = {
299 .type = cpu_to_be16(ETH_P_XDSA),
300 .func = dsa_switch_rcv,
301 };
302
303 static struct workqueue_struct *dsa_owq;
304
dsa_schedule_work(struct work_struct * work)305 bool dsa_schedule_work(struct work_struct *work)
306 {
307 return queue_work(dsa_owq, work);
308 }
309
310 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
311
register_dsa_notifier(struct notifier_block * nb)312 int register_dsa_notifier(struct notifier_block *nb)
313 {
314 return atomic_notifier_chain_register(&dsa_notif_chain, nb);
315 }
316 EXPORT_SYMBOL_GPL(register_dsa_notifier);
317
unregister_dsa_notifier(struct notifier_block * nb)318 int unregister_dsa_notifier(struct notifier_block *nb)
319 {
320 return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
321 }
322 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
323
call_dsa_notifiers(unsigned long val,struct net_device * dev,struct dsa_notifier_info * info)324 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
325 struct dsa_notifier_info *info)
326 {
327 info->dev = dev;
328 return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
329 }
330 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
331
dsa_init_module(void)332 static int __init dsa_init_module(void)
333 {
334 int rc;
335
336 dsa_owq = alloc_ordered_workqueue("dsa_ordered",
337 WQ_MEM_RECLAIM);
338 if (!dsa_owq)
339 return -ENOMEM;
340
341 rc = dsa_slave_register_notifier();
342 if (rc)
343 goto register_notifier_fail;
344
345 dev_add_pack(&dsa_pack_type);
346
347 dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
348 THIS_MODULE);
349
350 return 0;
351
352 register_notifier_fail:
353 destroy_workqueue(dsa_owq);
354
355 return rc;
356 }
357 module_init(dsa_init_module);
358
dsa_cleanup_module(void)359 static void __exit dsa_cleanup_module(void)
360 {
361 dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
362
363 dsa_slave_unregister_notifier();
364 dev_remove_pack(&dsa_pack_type);
365 destroy_workqueue(dsa_owq);
366 }
367 module_exit(dsa_cleanup_module);
368
369 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
370 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
371 MODULE_LICENSE("GPL");
372 MODULE_ALIAS("platform:dsa");
373