xref: /linux/net/dsa/dsa.c (revision a8b70ccf10e38775785d9cb12ead916474549f99)
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/of_gpio.h>
23 #include <linux/netdevice.h>
24 #include <linux/sysfs.h>
25 #include <linux/phy_fixed.h>
26 #include <linux/ptp_classify.h>
27 #include <linux/gpio/consumer.h>
28 #include <linux/etherdevice.h>
29 
30 #include "dsa_priv.h"
31 
32 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
33 					    struct net_device *dev)
34 {
35 	/* Just return the original SKB */
36 	return skb;
37 }
38 
39 static const struct dsa_device_ops none_ops = {
40 	.xmit	= dsa_slave_notag_xmit,
41 	.rcv	= NULL,
42 };
43 
44 const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
45 #ifdef CONFIG_NET_DSA_TAG_BRCM
46 	[DSA_TAG_PROTO_BRCM] = &brcm_netdev_ops,
47 #endif
48 #ifdef CONFIG_NET_DSA_TAG_BRCM_PREPEND
49 	[DSA_TAG_PROTO_BRCM_PREPEND] = &brcm_prepend_netdev_ops,
50 #endif
51 #ifdef CONFIG_NET_DSA_TAG_DSA
52 	[DSA_TAG_PROTO_DSA] = &dsa_netdev_ops,
53 #endif
54 #ifdef CONFIG_NET_DSA_TAG_EDSA
55 	[DSA_TAG_PROTO_EDSA] = &edsa_netdev_ops,
56 #endif
57 #ifdef CONFIG_NET_DSA_TAG_KSZ
58 	[DSA_TAG_PROTO_KSZ] = &ksz_netdev_ops,
59 #endif
60 #ifdef CONFIG_NET_DSA_TAG_LAN9303
61 	[DSA_TAG_PROTO_LAN9303] = &lan9303_netdev_ops,
62 #endif
63 #ifdef CONFIG_NET_DSA_TAG_MTK
64 	[DSA_TAG_PROTO_MTK] = &mtk_netdev_ops,
65 #endif
66 #ifdef CONFIG_NET_DSA_TAG_QCA
67 	[DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
68 #endif
69 #ifdef CONFIG_NET_DSA_TAG_TRAILER
70 	[DSA_TAG_PROTO_TRAILER] = &trailer_netdev_ops,
71 #endif
72 	[DSA_TAG_PROTO_NONE] = &none_ops,
73 };
74 
75 const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol)
76 {
77 	const struct dsa_device_ops *ops;
78 
79 	if (tag_protocol >= DSA_TAG_LAST)
80 		return ERR_PTR(-EINVAL);
81 	ops = dsa_device_ops[tag_protocol];
82 
83 	if (!ops)
84 		return ERR_PTR(-ENOPROTOOPT);
85 
86 	return ops;
87 }
88 
89 static int dev_is_class(struct device *dev, void *class)
90 {
91 	if (dev->class != NULL && !strcmp(dev->class->name, class))
92 		return 1;
93 
94 	return 0;
95 }
96 
97 static struct device *dev_find_class(struct device *parent, char *class)
98 {
99 	if (dev_is_class(parent, class)) {
100 		get_device(parent);
101 		return parent;
102 	}
103 
104 	return device_find_child(parent, class, dev_is_class);
105 }
106 
107 struct net_device *dsa_dev_to_net_device(struct device *dev)
108 {
109 	struct device *d;
110 
111 	d = dev_find_class(dev, "net");
112 	if (d != NULL) {
113 		struct net_device *nd;
114 
115 		nd = to_net_dev(d);
116 		dev_hold(nd);
117 		put_device(d);
118 
119 		return nd;
120 	}
121 
122 	return NULL;
123 }
124 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
125 
126 /* Determine if we should defer delivery of skb until we have a rx timestamp.
127  *
128  * Called from dsa_switch_rcv. For now, this will only work if tagging is
129  * enabled on the switch. Normally the MAC driver would retrieve the hardware
130  * timestamp when it reads the packet out of the hardware. However in a DSA
131  * switch, the DSA driver owning the interface to which the packet is
132  * delivered is never notified unless we do so here.
133  */
134 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
135 				       struct sk_buff *skb)
136 {
137 	struct dsa_switch *ds = p->dp->ds;
138 	unsigned int type;
139 
140 	if (skb_headroom(skb) < ETH_HLEN)
141 		return false;
142 
143 	__skb_push(skb, ETH_HLEN);
144 
145 	type = ptp_classify_raw(skb);
146 
147 	__skb_pull(skb, ETH_HLEN);
148 
149 	if (type == PTP_CLASS_NONE)
150 		return false;
151 
152 	if (likely(ds->ops->port_rxtstamp))
153 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
154 
155 	return false;
156 }
157 
158 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
159 			  struct packet_type *pt, struct net_device *unused)
160 {
161 	struct dsa_port *cpu_dp = dev->dsa_ptr;
162 	struct sk_buff *nskb = NULL;
163 	struct pcpu_sw_netstats *s;
164 	struct dsa_slave_priv *p;
165 
166 	if (unlikely(!cpu_dp)) {
167 		kfree_skb(skb);
168 		return 0;
169 	}
170 
171 	skb = skb_unshare(skb, GFP_ATOMIC);
172 	if (!skb)
173 		return 0;
174 
175 	nskb = cpu_dp->rcv(skb, dev, pt);
176 	if (!nskb) {
177 		kfree_skb(skb);
178 		return 0;
179 	}
180 
181 	skb = nskb;
182 	p = netdev_priv(skb->dev);
183 	skb_push(skb, ETH_HLEN);
184 	skb->pkt_type = PACKET_HOST;
185 	skb->protocol = eth_type_trans(skb, skb->dev);
186 
187 	s = this_cpu_ptr(p->stats64);
188 	u64_stats_update_begin(&s->syncp);
189 	s->rx_packets++;
190 	s->rx_bytes += skb->len;
191 	u64_stats_update_end(&s->syncp);
192 
193 	if (dsa_skb_defer_rx_timestamp(p, skb))
194 		return 0;
195 
196 	netif_receive_skb(skb);
197 
198 	return 0;
199 }
200 
201 #ifdef CONFIG_PM_SLEEP
202 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
203 {
204 	return dsa_is_user_port(ds, p) && ds->ports[p].slave;
205 }
206 
207 int dsa_switch_suspend(struct dsa_switch *ds)
208 {
209 	int i, ret = 0;
210 
211 	/* Suspend slave network devices */
212 	for (i = 0; i < ds->num_ports; i++) {
213 		if (!dsa_is_port_initialized(ds, i))
214 			continue;
215 
216 		ret = dsa_slave_suspend(ds->ports[i].slave);
217 		if (ret)
218 			return ret;
219 	}
220 
221 	if (ds->ops->suspend)
222 		ret = ds->ops->suspend(ds);
223 
224 	return ret;
225 }
226 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
227 
228 int dsa_switch_resume(struct dsa_switch *ds)
229 {
230 	int i, ret = 0;
231 
232 	if (ds->ops->resume)
233 		ret = ds->ops->resume(ds);
234 
235 	if (ret)
236 		return ret;
237 
238 	/* Resume slave network devices */
239 	for (i = 0; i < ds->num_ports; i++) {
240 		if (!dsa_is_port_initialized(ds, i))
241 			continue;
242 
243 		ret = dsa_slave_resume(ds->ports[i].slave);
244 		if (ret)
245 			return ret;
246 	}
247 
248 	return 0;
249 }
250 EXPORT_SYMBOL_GPL(dsa_switch_resume);
251 #endif
252 
253 static struct packet_type dsa_pack_type __read_mostly = {
254 	.type	= cpu_to_be16(ETH_P_XDSA),
255 	.func	= dsa_switch_rcv,
256 };
257 
258 static struct workqueue_struct *dsa_owq;
259 
260 bool dsa_schedule_work(struct work_struct *work)
261 {
262 	return queue_work(dsa_owq, work);
263 }
264 
265 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
266 
267 int register_dsa_notifier(struct notifier_block *nb)
268 {
269 	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
270 }
271 EXPORT_SYMBOL_GPL(register_dsa_notifier);
272 
273 int unregister_dsa_notifier(struct notifier_block *nb)
274 {
275 	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
276 }
277 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
278 
279 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
280 		       struct dsa_notifier_info *info)
281 {
282 	info->dev = dev;
283 	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
284 }
285 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
286 
287 static int __init dsa_init_module(void)
288 {
289 	int rc;
290 
291 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
292 					  WQ_MEM_RECLAIM);
293 	if (!dsa_owq)
294 		return -ENOMEM;
295 
296 	rc = dsa_slave_register_notifier();
297 	if (rc)
298 		return rc;
299 
300 	rc = dsa_legacy_register();
301 	if (rc)
302 		return rc;
303 
304 	dev_add_pack(&dsa_pack_type);
305 
306 	return 0;
307 }
308 module_init(dsa_init_module);
309 
310 static void __exit dsa_cleanup_module(void)
311 {
312 	dsa_slave_unregister_notifier();
313 	dev_remove_pack(&dsa_pack_type);
314 	dsa_legacy_unregister();
315 	destroy_workqueue(dsa_owq);
316 }
317 module_exit(dsa_cleanup_module);
318 
319 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
320 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
321 MODULE_LICENSE("GPL");
322 MODULE_ALIAS("platform:dsa");
323