xref: /openbmc/linux/net/dsa/dsa.c (revision 565d76cb)
1  /*
2   * net/dsa/dsa.c - Hardware switch handling
3   * Copyright (c) 2008-2009 Marvell Semiconductor
4   *
5   * This program is free software; you can redistribute it and/or modify
6   * it under the terms of the GNU General Public License as published by
7   * the Free Software Foundation; either version 2 of the License, or
8   * (at your option) any later version.
9   */
10  
11  #include <linux/list.h>
12  #include <linux/netdevice.h>
13  #include <linux/platform_device.h>
14  #include <linux/slab.h>
15  #include <net/dsa.h>
16  #include "dsa_priv.h"
17  
18  char dsa_driver_version[] = "0.1";
19  
20  
21  /* switch driver registration ***********************************************/
22  static DEFINE_MUTEX(dsa_switch_drivers_mutex);
23  static LIST_HEAD(dsa_switch_drivers);
24  
25  void register_switch_driver(struct dsa_switch_driver *drv)
26  {
27  	mutex_lock(&dsa_switch_drivers_mutex);
28  	list_add_tail(&drv->list, &dsa_switch_drivers);
29  	mutex_unlock(&dsa_switch_drivers_mutex);
30  }
31  
32  void unregister_switch_driver(struct dsa_switch_driver *drv)
33  {
34  	mutex_lock(&dsa_switch_drivers_mutex);
35  	list_del_init(&drv->list);
36  	mutex_unlock(&dsa_switch_drivers_mutex);
37  }
38  
39  static struct dsa_switch_driver *
40  dsa_switch_probe(struct mii_bus *bus, int sw_addr, char **_name)
41  {
42  	struct dsa_switch_driver *ret;
43  	struct list_head *list;
44  	char *name;
45  
46  	ret = NULL;
47  	name = NULL;
48  
49  	mutex_lock(&dsa_switch_drivers_mutex);
50  	list_for_each(list, &dsa_switch_drivers) {
51  		struct dsa_switch_driver *drv;
52  
53  		drv = list_entry(list, struct dsa_switch_driver, list);
54  
55  		name = drv->probe(bus, sw_addr);
56  		if (name != NULL) {
57  			ret = drv;
58  			break;
59  		}
60  	}
61  	mutex_unlock(&dsa_switch_drivers_mutex);
62  
63  	*_name = name;
64  
65  	return ret;
66  }
67  
68  
69  /* basic switch operations **************************************************/
70  static struct dsa_switch *
71  dsa_switch_setup(struct dsa_switch_tree *dst, int index,
72  		 struct device *parent, struct mii_bus *bus)
73  {
74  	struct dsa_chip_data *pd = dst->pd->chip + index;
75  	struct dsa_switch_driver *drv;
76  	struct dsa_switch *ds;
77  	int ret;
78  	char *name;
79  	int i;
80  
81  	/*
82  	 * Probe for switch model.
83  	 */
84  	drv = dsa_switch_probe(bus, pd->sw_addr, &name);
85  	if (drv == NULL) {
86  		printk(KERN_ERR "%s[%d]: could not detect attached switch\n",
87  		       dst->master_netdev->name, index);
88  		return ERR_PTR(-EINVAL);
89  	}
90  	printk(KERN_INFO "%s[%d]: detected a %s switch\n",
91  		dst->master_netdev->name, index, name);
92  
93  
94  	/*
95  	 * Allocate and initialise switch state.
96  	 */
97  	ds = kzalloc(sizeof(*ds) + drv->priv_size, GFP_KERNEL);
98  	if (ds == NULL)
99  		return ERR_PTR(-ENOMEM);
100  
101  	ds->dst = dst;
102  	ds->index = index;
103  	ds->pd = dst->pd->chip + index;
104  	ds->drv = drv;
105  	ds->master_mii_bus = bus;
106  
107  
108  	/*
109  	 * Validate supplied switch configuration.
110  	 */
111  	for (i = 0; i < DSA_MAX_PORTS; i++) {
112  		char *name;
113  
114  		name = pd->port_names[i];
115  		if (name == NULL)
116  			continue;
117  
118  		if (!strcmp(name, "cpu")) {
119  			if (dst->cpu_switch != -1) {
120  				printk(KERN_ERR "multiple cpu ports?!\n");
121  				ret = -EINVAL;
122  				goto out;
123  			}
124  			dst->cpu_switch = index;
125  			dst->cpu_port = i;
126  		} else if (!strcmp(name, "dsa")) {
127  			ds->dsa_port_mask |= 1 << i;
128  		} else {
129  			ds->phys_port_mask |= 1 << i;
130  		}
131  	}
132  
133  
134  	/*
135  	 * If the CPU connects to this switch, set the switch tree
136  	 * tagging protocol to the preferred tagging format of this
137  	 * switch.
138  	 */
139  	if (ds->dst->cpu_switch == index)
140  		ds->dst->tag_protocol = drv->tag_protocol;
141  
142  
143  	/*
144  	 * Do basic register setup.
145  	 */
146  	ret = drv->setup(ds);
147  	if (ret < 0)
148  		goto out;
149  
150  	ret = drv->set_addr(ds, dst->master_netdev->dev_addr);
151  	if (ret < 0)
152  		goto out;
153  
154  	ds->slave_mii_bus = mdiobus_alloc();
155  	if (ds->slave_mii_bus == NULL) {
156  		ret = -ENOMEM;
157  		goto out;
158  	}
159  	dsa_slave_mii_bus_init(ds);
160  
161  	ret = mdiobus_register(ds->slave_mii_bus);
162  	if (ret < 0)
163  		goto out_free;
164  
165  
166  	/*
167  	 * Create network devices for physical switch ports.
168  	 */
169  	for (i = 0; i < DSA_MAX_PORTS; i++) {
170  		struct net_device *slave_dev;
171  
172  		if (!(ds->phys_port_mask & (1 << i)))
173  			continue;
174  
175  		slave_dev = dsa_slave_create(ds, parent, i, pd->port_names[i]);
176  		if (slave_dev == NULL) {
177  			printk(KERN_ERR "%s[%d]: can't create dsa "
178  			       "slave device for port %d(%s)\n",
179  			       dst->master_netdev->name,
180  			       index, i, pd->port_names[i]);
181  			continue;
182  		}
183  
184  		ds->ports[i] = slave_dev;
185  	}
186  
187  	return ds;
188  
189  out_free:
190  	mdiobus_free(ds->slave_mii_bus);
191  out:
192  	kfree(ds);
193  	return ERR_PTR(ret);
194  }
195  
196  static void dsa_switch_destroy(struct dsa_switch *ds)
197  {
198  }
199  
200  
201  /* hooks for ethertype-less tagging formats *********************************/
202  /*
203   * The original DSA tag format and some other tag formats have no
204   * ethertype, which means that we need to add a little hack to the
205   * networking receive path to make sure that received frames get
206   * the right ->protocol assigned to them when one of those tag
207   * formats is in use.
208   */
209  bool dsa_uses_dsa_tags(void *dsa_ptr)
210  {
211  	struct dsa_switch_tree *dst = dsa_ptr;
212  
213  	return !!(dst->tag_protocol == htons(ETH_P_DSA));
214  }
215  
216  bool dsa_uses_trailer_tags(void *dsa_ptr)
217  {
218  	struct dsa_switch_tree *dst = dsa_ptr;
219  
220  	return !!(dst->tag_protocol == htons(ETH_P_TRAILER));
221  }
222  
223  
224  /* link polling *************************************************************/
225  static void dsa_link_poll_work(struct work_struct *ugly)
226  {
227  	struct dsa_switch_tree *dst;
228  	int i;
229  
230  	dst = container_of(ugly, struct dsa_switch_tree, link_poll_work);
231  
232  	for (i = 0; i < dst->pd->nr_chips; i++) {
233  		struct dsa_switch *ds = dst->ds[i];
234  
235  		if (ds != NULL && ds->drv->poll_link != NULL)
236  			ds->drv->poll_link(ds);
237  	}
238  
239  	mod_timer(&dst->link_poll_timer, round_jiffies(jiffies + HZ));
240  }
241  
242  static void dsa_link_poll_timer(unsigned long _dst)
243  {
244  	struct dsa_switch_tree *dst = (void *)_dst;
245  
246  	schedule_work(&dst->link_poll_work);
247  }
248  
249  
250  /* platform driver init and cleanup *****************************************/
251  static int dev_is_class(struct device *dev, void *class)
252  {
253  	if (dev->class != NULL && !strcmp(dev->class->name, class))
254  		return 1;
255  
256  	return 0;
257  }
258  
259  static struct device *dev_find_class(struct device *parent, char *class)
260  {
261  	if (dev_is_class(parent, class)) {
262  		get_device(parent);
263  		return parent;
264  	}
265  
266  	return device_find_child(parent, class, dev_is_class);
267  }
268  
269  static struct mii_bus *dev_to_mii_bus(struct device *dev)
270  {
271  	struct device *d;
272  
273  	d = dev_find_class(dev, "mdio_bus");
274  	if (d != NULL) {
275  		struct mii_bus *bus;
276  
277  		bus = to_mii_bus(d);
278  		put_device(d);
279  
280  		return bus;
281  	}
282  
283  	return NULL;
284  }
285  
286  static struct net_device *dev_to_net_device(struct device *dev)
287  {
288  	struct device *d;
289  
290  	d = dev_find_class(dev, "net");
291  	if (d != NULL) {
292  		struct net_device *nd;
293  
294  		nd = to_net_dev(d);
295  		dev_hold(nd);
296  		put_device(d);
297  
298  		return nd;
299  	}
300  
301  	return NULL;
302  }
303  
304  static int dsa_probe(struct platform_device *pdev)
305  {
306  	static int dsa_version_printed;
307  	struct dsa_platform_data *pd = pdev->dev.platform_data;
308  	struct net_device *dev;
309  	struct dsa_switch_tree *dst;
310  	int i;
311  
312  	if (!dsa_version_printed++)
313  		printk(KERN_NOTICE "Distributed Switch Architecture "
314  			"driver version %s\n", dsa_driver_version);
315  
316  	if (pd == NULL || pd->netdev == NULL)
317  		return -EINVAL;
318  
319  	dev = dev_to_net_device(pd->netdev);
320  	if (dev == NULL)
321  		return -EINVAL;
322  
323  	if (dev->dsa_ptr != NULL) {
324  		dev_put(dev);
325  		return -EEXIST;
326  	}
327  
328  	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
329  	if (dst == NULL) {
330  		dev_put(dev);
331  		return -ENOMEM;
332  	}
333  
334  	platform_set_drvdata(pdev, dst);
335  
336  	dst->pd = pd;
337  	dst->master_netdev = dev;
338  	dst->cpu_switch = -1;
339  	dst->cpu_port = -1;
340  
341  	for (i = 0; i < pd->nr_chips; i++) {
342  		struct mii_bus *bus;
343  		struct dsa_switch *ds;
344  
345  		bus = dev_to_mii_bus(pd->chip[i].mii_bus);
346  		if (bus == NULL) {
347  			printk(KERN_ERR "%s[%d]: no mii bus found for "
348  				"dsa switch\n", dev->name, i);
349  			continue;
350  		}
351  
352  		ds = dsa_switch_setup(dst, i, &pdev->dev, bus);
353  		if (IS_ERR(ds)) {
354  			printk(KERN_ERR "%s[%d]: couldn't create dsa switch "
355  				"instance (error %ld)\n", dev->name, i,
356  				PTR_ERR(ds));
357  			continue;
358  		}
359  
360  		dst->ds[i] = ds;
361  		if (ds->drv->poll_link != NULL)
362  			dst->link_poll_needed = 1;
363  	}
364  
365  	/*
366  	 * If we use a tagging format that doesn't have an ethertype
367  	 * field, make sure that all packets from this point on get
368  	 * sent to the tag format's receive function.
369  	 */
370  	wmb();
371  	dev->dsa_ptr = (void *)dst;
372  
373  	if (dst->link_poll_needed) {
374  		INIT_WORK(&dst->link_poll_work, dsa_link_poll_work);
375  		init_timer(&dst->link_poll_timer);
376  		dst->link_poll_timer.data = (unsigned long)dst;
377  		dst->link_poll_timer.function = dsa_link_poll_timer;
378  		dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
379  		add_timer(&dst->link_poll_timer);
380  	}
381  
382  	return 0;
383  }
384  
385  static int dsa_remove(struct platform_device *pdev)
386  {
387  	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
388  	int i;
389  
390  	if (dst->link_poll_needed)
391  		del_timer_sync(&dst->link_poll_timer);
392  
393  	flush_work_sync(&dst->link_poll_work);
394  
395  	for (i = 0; i < dst->pd->nr_chips; i++) {
396  		struct dsa_switch *ds = dst->ds[i];
397  
398  		if (ds != NULL)
399  			dsa_switch_destroy(ds);
400  	}
401  
402  	return 0;
403  }
404  
405  static void dsa_shutdown(struct platform_device *pdev)
406  {
407  }
408  
409  static struct platform_driver dsa_driver = {
410  	.probe		= dsa_probe,
411  	.remove		= dsa_remove,
412  	.shutdown	= dsa_shutdown,
413  	.driver = {
414  		.name	= "dsa",
415  		.owner	= THIS_MODULE,
416  	},
417  };
418  
419  static int __init dsa_init_module(void)
420  {
421  	return platform_driver_register(&dsa_driver);
422  }
423  module_init(dsa_init_module);
424  
425  static void __exit dsa_cleanup_module(void)
426  {
427  	platform_driver_unregister(&dsa_driver);
428  }
429  module_exit(dsa_cleanup_module);
430  
431  MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
432  MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
433  MODULE_LICENSE("GPL");
434  MODULE_ALIAS("platform:dsa");
435