xref: /openbmc/linux/net/dsa/dsa.c (revision 8dfb839c)
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_KSZ
56 	[DSA_TAG_PROTO_KSZ] = &ksz_netdev_ops,
57 #endif
58 #ifdef CONFIG_NET_DSA_TAG_LAN9303
59 	[DSA_TAG_PROTO_LAN9303] = &lan9303_netdev_ops,
60 #endif
61 #ifdef CONFIG_NET_DSA_TAG_MTK
62 	[DSA_TAG_PROTO_MTK] = &mtk_netdev_ops,
63 #endif
64 #ifdef CONFIG_NET_DSA_TAG_QCA
65 	[DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
66 #endif
67 #ifdef CONFIG_NET_DSA_TAG_TRAILER
68 	[DSA_TAG_PROTO_TRAILER] = &trailer_netdev_ops,
69 #endif
70 	[DSA_TAG_PROTO_NONE] = &none_ops,
71 };
72 
73 const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol)
74 {
75 	const struct dsa_device_ops *ops;
76 
77 	if (tag_protocol >= DSA_TAG_LAST)
78 		return ERR_PTR(-EINVAL);
79 	ops = dsa_device_ops[tag_protocol];
80 
81 	if (!ops)
82 		return ERR_PTR(-ENOPROTOOPT);
83 
84 	return ops;
85 }
86 
87 static int dev_is_class(struct device *dev, void *class)
88 {
89 	if (dev->class != NULL && !strcmp(dev->class->name, class))
90 		return 1;
91 
92 	return 0;
93 }
94 
95 static struct device *dev_find_class(struct device *parent, char *class)
96 {
97 	if (dev_is_class(parent, class)) {
98 		get_device(parent);
99 		return parent;
100 	}
101 
102 	return device_find_child(parent, class, dev_is_class);
103 }
104 
105 struct net_device *dsa_dev_to_net_device(struct device *dev)
106 {
107 	struct device *d;
108 
109 	d = dev_find_class(dev, "net");
110 	if (d != NULL) {
111 		struct net_device *nd;
112 
113 		nd = to_net_dev(d);
114 		dev_hold(nd);
115 		put_device(d);
116 
117 		return nd;
118 	}
119 
120 	return NULL;
121 }
122 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
123 
124 /* Determine if we should defer delivery of skb until we have a rx timestamp.
125  *
126  * Called from dsa_switch_rcv. For now, this will only work if tagging is
127  * enabled on the switch. Normally the MAC driver would retrieve the hardware
128  * timestamp when it reads the packet out of the hardware. However in a DSA
129  * switch, the DSA driver owning the interface to which the packet is
130  * delivered is never notified unless we do so here.
131  */
132 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
133 				       struct sk_buff *skb)
134 {
135 	struct dsa_switch *ds = p->dp->ds;
136 	unsigned int type;
137 
138 	if (skb_headroom(skb) < ETH_HLEN)
139 		return false;
140 
141 	__skb_push(skb, ETH_HLEN);
142 
143 	type = ptp_classify_raw(skb);
144 
145 	__skb_pull(skb, ETH_HLEN);
146 
147 	if (type == PTP_CLASS_NONE)
148 		return false;
149 
150 	if (likely(ds->ops->port_rxtstamp))
151 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
152 
153 	return false;
154 }
155 
156 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
157 			  struct packet_type *pt, struct net_device *unused)
158 {
159 	struct dsa_port *cpu_dp = dev->dsa_ptr;
160 	struct sk_buff *nskb = NULL;
161 	struct pcpu_sw_netstats *s;
162 	struct dsa_slave_priv *p;
163 
164 	if (unlikely(!cpu_dp)) {
165 		kfree_skb(skb);
166 		return 0;
167 	}
168 
169 	skb = skb_unshare(skb, GFP_ATOMIC);
170 	if (!skb)
171 		return 0;
172 
173 	nskb = cpu_dp->rcv(skb, dev, pt);
174 	if (!nskb) {
175 		kfree_skb(skb);
176 		return 0;
177 	}
178 
179 	skb = nskb;
180 	p = netdev_priv(skb->dev);
181 	skb_push(skb, ETH_HLEN);
182 	skb->pkt_type = PACKET_HOST;
183 	skb->protocol = eth_type_trans(skb, skb->dev);
184 
185 	s = this_cpu_ptr(p->stats64);
186 	u64_stats_update_begin(&s->syncp);
187 	s->rx_packets++;
188 	s->rx_bytes += skb->len;
189 	u64_stats_update_end(&s->syncp);
190 
191 	if (dsa_skb_defer_rx_timestamp(p, skb))
192 		return 0;
193 
194 	netif_receive_skb(skb);
195 
196 	return 0;
197 }
198 
199 #ifdef CONFIG_PM_SLEEP
200 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
201 {
202 	return dsa_is_user_port(ds, p) && ds->ports[p].slave;
203 }
204 
205 int dsa_switch_suspend(struct dsa_switch *ds)
206 {
207 	int i, ret = 0;
208 
209 	/* Suspend slave network devices */
210 	for (i = 0; i < ds->num_ports; i++) {
211 		if (!dsa_is_port_initialized(ds, i))
212 			continue;
213 
214 		ret = dsa_slave_suspend(ds->ports[i].slave);
215 		if (ret)
216 			return ret;
217 	}
218 
219 	if (ds->ops->suspend)
220 		ret = ds->ops->suspend(ds);
221 
222 	return ret;
223 }
224 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
225 
226 int dsa_switch_resume(struct dsa_switch *ds)
227 {
228 	int i, ret = 0;
229 
230 	if (ds->ops->resume)
231 		ret = ds->ops->resume(ds);
232 
233 	if (ret)
234 		return ret;
235 
236 	/* Resume slave network devices */
237 	for (i = 0; i < ds->num_ports; i++) {
238 		if (!dsa_is_port_initialized(ds, i))
239 			continue;
240 
241 		ret = dsa_slave_resume(ds->ports[i].slave);
242 		if (ret)
243 			return ret;
244 	}
245 
246 	return 0;
247 }
248 EXPORT_SYMBOL_GPL(dsa_switch_resume);
249 #endif
250 
251 static struct packet_type dsa_pack_type __read_mostly = {
252 	.type	= cpu_to_be16(ETH_P_XDSA),
253 	.func	= dsa_switch_rcv,
254 };
255 
256 static struct workqueue_struct *dsa_owq;
257 
258 bool dsa_schedule_work(struct work_struct *work)
259 {
260 	return queue_work(dsa_owq, work);
261 }
262 
263 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
264 
265 int register_dsa_notifier(struct notifier_block *nb)
266 {
267 	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
268 }
269 EXPORT_SYMBOL_GPL(register_dsa_notifier);
270 
271 int unregister_dsa_notifier(struct notifier_block *nb)
272 {
273 	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
274 }
275 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
276 
277 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
278 		       struct dsa_notifier_info *info)
279 {
280 	info->dev = dev;
281 	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
282 }
283 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
284 
285 static int __init dsa_init_module(void)
286 {
287 	int rc;
288 
289 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
290 					  WQ_MEM_RECLAIM);
291 	if (!dsa_owq)
292 		return -ENOMEM;
293 
294 	rc = dsa_slave_register_notifier();
295 	if (rc)
296 		return rc;
297 
298 	rc = dsa_legacy_register();
299 	if (rc)
300 		return rc;
301 
302 	dev_add_pack(&dsa_pack_type);
303 
304 	return 0;
305 }
306 module_init(dsa_init_module);
307 
308 static void __exit dsa_cleanup_module(void)
309 {
310 	dsa_slave_unregister_notifier();
311 	dev_remove_pack(&dsa_pack_type);
312 	dsa_legacy_unregister();
313 	destroy_workqueue(dsa_owq);
314 }
315 module_exit(dsa_cleanup_module);
316 
317 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
318 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
319 MODULE_LICENSE("GPL");
320 MODULE_ALIAS("platform:dsa");
321