xref: /linux/net/dsa/dsa.c (revision dd2934a95701576203b2f61e8ded4e4a2f9183ea)
1 /*
2  * net/dsa/dsa.c - Hardware switch handling
3  * Copyright (c) 2008-2009 Marvell Semiconductor
4  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/device.h>
13 #include <linux/list.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/notifier.h>
18 #include <linux/of.h>
19 #include <linux/of_mdio.h>
20 #include <linux/of_platform.h>
21 #include <linux/of_net.h>
22 #include <linux/netdevice.h>
23 #include <linux/sysfs.h>
24 #include <linux/phy_fixed.h>
25 #include <linux/ptp_classify.h>
26 #include <linux/etherdevice.h>
27 
28 #include "dsa_priv.h"
29 
30 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
31 					    struct net_device *dev)
32 {
33 	/* Just return the original SKB */
34 	return skb;
35 }
36 
37 static const struct dsa_device_ops none_ops = {
38 	.xmit	= dsa_slave_notag_xmit,
39 	.rcv	= NULL,
40 };
41 
42 const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
43 #ifdef CONFIG_NET_DSA_TAG_BRCM
44 	[DSA_TAG_PROTO_BRCM] = &brcm_netdev_ops,
45 #endif
46 #ifdef CONFIG_NET_DSA_TAG_BRCM_PREPEND
47 	[DSA_TAG_PROTO_BRCM_PREPEND] = &brcm_prepend_netdev_ops,
48 #endif
49 #ifdef CONFIG_NET_DSA_TAG_DSA
50 	[DSA_TAG_PROTO_DSA] = &dsa_netdev_ops,
51 #endif
52 #ifdef CONFIG_NET_DSA_TAG_EDSA
53 	[DSA_TAG_PROTO_EDSA] = &edsa_netdev_ops,
54 #endif
55 #ifdef CONFIG_NET_DSA_TAG_GSWIP
56 	[DSA_TAG_PROTO_GSWIP] = &gswip_netdev_ops,
57 #endif
58 #ifdef CONFIG_NET_DSA_TAG_KSZ
59 	[DSA_TAG_PROTO_KSZ] = &ksz_netdev_ops,
60 #endif
61 #ifdef CONFIG_NET_DSA_TAG_LAN9303
62 	[DSA_TAG_PROTO_LAN9303] = &lan9303_netdev_ops,
63 #endif
64 #ifdef CONFIG_NET_DSA_TAG_MTK
65 	[DSA_TAG_PROTO_MTK] = &mtk_netdev_ops,
66 #endif
67 #ifdef CONFIG_NET_DSA_TAG_QCA
68 	[DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
69 #endif
70 #ifdef CONFIG_NET_DSA_TAG_TRAILER
71 	[DSA_TAG_PROTO_TRAILER] = &trailer_netdev_ops,
72 #endif
73 	[DSA_TAG_PROTO_NONE] = &none_ops,
74 };
75 
76 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
77 {
78 	const char *protocol_name[DSA_TAG_LAST] = {
79 #ifdef CONFIG_NET_DSA_TAG_BRCM
80 		[DSA_TAG_PROTO_BRCM] = "brcm",
81 #endif
82 #ifdef CONFIG_NET_DSA_TAG_BRCM_PREPEND
83 		[DSA_TAG_PROTO_BRCM_PREPEND] = "brcm-prepend",
84 #endif
85 #ifdef CONFIG_NET_DSA_TAG_DSA
86 		[DSA_TAG_PROTO_DSA] = "dsa",
87 #endif
88 #ifdef CONFIG_NET_DSA_TAG_EDSA
89 		[DSA_TAG_PROTO_EDSA] = "edsa",
90 #endif
91 #ifdef CONFIG_NET_DSA_TAG_KSZ
92 		[DSA_TAG_PROTO_KSZ] = "ksz",
93 #endif
94 #ifdef CONFIG_NET_DSA_TAG_LAN9303
95 		[DSA_TAG_PROTO_LAN9303] = "lan9303",
96 #endif
97 #ifdef CONFIG_NET_DSA_TAG_MTK
98 		[DSA_TAG_PROTO_MTK] = "mtk",
99 #endif
100 #ifdef CONFIG_NET_DSA_TAG_QCA
101 		[DSA_TAG_PROTO_QCA] = "qca",
102 #endif
103 #ifdef CONFIG_NET_DSA_TAG_TRAILER
104 		[DSA_TAG_PROTO_TRAILER] = "trailer",
105 #endif
106 		[DSA_TAG_PROTO_NONE] = "none",
107 	};
108 	unsigned int i;
109 
110 	BUILD_BUG_ON(ARRAY_SIZE(protocol_name) != DSA_TAG_LAST);
111 
112 	for (i = 0; i < ARRAY_SIZE(dsa_device_ops); i++)
113 		if (ops == dsa_device_ops[i])
114 			return protocol_name[i];
115 
116 	return protocol_name[DSA_TAG_PROTO_NONE];
117 };
118 
119 const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol)
120 {
121 	const struct dsa_device_ops *ops;
122 
123 	if (tag_protocol >= DSA_TAG_LAST)
124 		return ERR_PTR(-EINVAL);
125 	ops = dsa_device_ops[tag_protocol];
126 
127 	if (!ops)
128 		return ERR_PTR(-ENOPROTOOPT);
129 
130 	return ops;
131 }
132 
133 static int dev_is_class(struct device *dev, void *class)
134 {
135 	if (dev->class != NULL && !strcmp(dev->class->name, class))
136 		return 1;
137 
138 	return 0;
139 }
140 
141 static struct device *dev_find_class(struct device *parent, char *class)
142 {
143 	if (dev_is_class(parent, class)) {
144 		get_device(parent);
145 		return parent;
146 	}
147 
148 	return device_find_child(parent, class, dev_is_class);
149 }
150 
151 struct net_device *dsa_dev_to_net_device(struct device *dev)
152 {
153 	struct device *d;
154 
155 	d = dev_find_class(dev, "net");
156 	if (d != NULL) {
157 		struct net_device *nd;
158 
159 		nd = to_net_dev(d);
160 		dev_hold(nd);
161 		put_device(d);
162 
163 		return nd;
164 	}
165 
166 	return NULL;
167 }
168 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
169 
170 /* Determine if we should defer delivery of skb until we have a rx timestamp.
171  *
172  * Called from dsa_switch_rcv. For now, this will only work if tagging is
173  * enabled on the switch. Normally the MAC driver would retrieve the hardware
174  * timestamp when it reads the packet out of the hardware. However in a DSA
175  * switch, the DSA driver owning the interface to which the packet is
176  * delivered is never notified unless we do so here.
177  */
178 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
179 				       struct sk_buff *skb)
180 {
181 	struct dsa_switch *ds = p->dp->ds;
182 	unsigned int type;
183 
184 	if (skb_headroom(skb) < ETH_HLEN)
185 		return false;
186 
187 	__skb_push(skb, ETH_HLEN);
188 
189 	type = ptp_classify_raw(skb);
190 
191 	__skb_pull(skb, ETH_HLEN);
192 
193 	if (type == PTP_CLASS_NONE)
194 		return false;
195 
196 	if (likely(ds->ops->port_rxtstamp))
197 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
198 
199 	return false;
200 }
201 
202 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
203 			  struct packet_type *pt, struct net_device *unused)
204 {
205 	struct dsa_port *cpu_dp = dev->dsa_ptr;
206 	struct sk_buff *nskb = NULL;
207 	struct pcpu_sw_netstats *s;
208 	struct dsa_slave_priv *p;
209 
210 	if (unlikely(!cpu_dp)) {
211 		kfree_skb(skb);
212 		return 0;
213 	}
214 
215 	skb = skb_unshare(skb, GFP_ATOMIC);
216 	if (!skb)
217 		return 0;
218 
219 	nskb = cpu_dp->rcv(skb, dev, pt);
220 	if (!nskb) {
221 		kfree_skb(skb);
222 		return 0;
223 	}
224 
225 	skb = nskb;
226 	p = netdev_priv(skb->dev);
227 	skb_push(skb, ETH_HLEN);
228 	skb->pkt_type = PACKET_HOST;
229 	skb->protocol = eth_type_trans(skb, skb->dev);
230 
231 	s = this_cpu_ptr(p->stats64);
232 	u64_stats_update_begin(&s->syncp);
233 	s->rx_packets++;
234 	s->rx_bytes += skb->len;
235 	u64_stats_update_end(&s->syncp);
236 
237 	if (dsa_skb_defer_rx_timestamp(p, skb))
238 		return 0;
239 
240 	netif_receive_skb(skb);
241 
242 	return 0;
243 }
244 
245 #ifdef CONFIG_PM_SLEEP
246 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
247 {
248 	return dsa_is_user_port(ds, p) && ds->ports[p].slave;
249 }
250 
251 int dsa_switch_suspend(struct dsa_switch *ds)
252 {
253 	int i, ret = 0;
254 
255 	/* Suspend slave network devices */
256 	for (i = 0; i < ds->num_ports; i++) {
257 		if (!dsa_is_port_initialized(ds, i))
258 			continue;
259 
260 		ret = dsa_slave_suspend(ds->ports[i].slave);
261 		if (ret)
262 			return ret;
263 	}
264 
265 	if (ds->ops->suspend)
266 		ret = ds->ops->suspend(ds);
267 
268 	return ret;
269 }
270 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
271 
272 int dsa_switch_resume(struct dsa_switch *ds)
273 {
274 	int i, ret = 0;
275 
276 	if (ds->ops->resume)
277 		ret = ds->ops->resume(ds);
278 
279 	if (ret)
280 		return ret;
281 
282 	/* Resume slave network devices */
283 	for (i = 0; i < ds->num_ports; i++) {
284 		if (!dsa_is_port_initialized(ds, i))
285 			continue;
286 
287 		ret = dsa_slave_resume(ds->ports[i].slave);
288 		if (ret)
289 			return ret;
290 	}
291 
292 	return 0;
293 }
294 EXPORT_SYMBOL_GPL(dsa_switch_resume);
295 #endif
296 
297 static struct packet_type dsa_pack_type __read_mostly = {
298 	.type	= cpu_to_be16(ETH_P_XDSA),
299 	.func	= dsa_switch_rcv,
300 };
301 
302 static struct workqueue_struct *dsa_owq;
303 
304 bool dsa_schedule_work(struct work_struct *work)
305 {
306 	return queue_work(dsa_owq, work);
307 }
308 
309 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
310 
311 int register_dsa_notifier(struct notifier_block *nb)
312 {
313 	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
314 }
315 EXPORT_SYMBOL_GPL(register_dsa_notifier);
316 
317 int unregister_dsa_notifier(struct notifier_block *nb)
318 {
319 	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
320 }
321 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
322 
323 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
324 		       struct dsa_notifier_info *info)
325 {
326 	info->dev = dev;
327 	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
328 }
329 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
330 
331 static int __init dsa_init_module(void)
332 {
333 	int rc;
334 
335 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
336 					  WQ_MEM_RECLAIM);
337 	if (!dsa_owq)
338 		return -ENOMEM;
339 
340 	rc = dsa_slave_register_notifier();
341 	if (rc)
342 		return rc;
343 
344 	rc = dsa_legacy_register();
345 	if (rc)
346 		return rc;
347 
348 	dev_add_pack(&dsa_pack_type);
349 
350 	return 0;
351 }
352 module_init(dsa_init_module);
353 
354 static void __exit dsa_cleanup_module(void)
355 {
356 	dsa_slave_unregister_notifier();
357 	dev_remove_pack(&dsa_pack_type);
358 	dsa_legacy_unregister();
359 	destroy_workqueue(dsa_owq);
360 }
361 module_exit(dsa_cleanup_module);
362 
363 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
364 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
365 MODULE_LICENSE("GPL");
366 MODULE_ALIAS("platform:dsa");
367