xref: /openbmc/linux/net/ieee802154/core.c (revision 9cfc5c90)
1 /*
2  * Copyright (C) 2007, 2008, 2009 Siemens AG
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2
6  * as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 
20 #include <net/cfg802154.h>
21 #include <net/rtnetlink.h>
22 
23 #include "ieee802154.h"
24 #include "nl802154.h"
25 #include "sysfs.h"
26 #include "core.h"
27 
28 /* name for sysfs, %d is appended */
29 #define PHY_NAME "phy"
30 
31 /* RCU-protected (and RTNL for writers) */
32 LIST_HEAD(cfg802154_rdev_list);
33 int cfg802154_rdev_list_generation;
34 
35 static int wpan_phy_match(struct device *dev, const void *data)
36 {
37 	return !strcmp(dev_name(dev), (const char *)data);
38 }
39 
40 struct wpan_phy *wpan_phy_find(const char *str)
41 {
42 	struct device *dev;
43 
44 	if (WARN_ON(!str))
45 		return NULL;
46 
47 	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
48 	if (!dev)
49 		return NULL;
50 
51 	return container_of(dev, struct wpan_phy, dev);
52 }
53 EXPORT_SYMBOL(wpan_phy_find);
54 
55 struct wpan_phy_iter_data {
56 	int (*fn)(struct wpan_phy *phy, void *data);
57 	void *data;
58 };
59 
60 static int wpan_phy_iter(struct device *dev, void *_data)
61 {
62 	struct wpan_phy_iter_data *wpid = _data;
63 	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
64 
65 	return wpid->fn(phy, wpid->data);
66 }
67 
68 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
69 		      void *data)
70 {
71 	struct wpan_phy_iter_data wpid = {
72 		.fn = fn,
73 		.data = data,
74 	};
75 
76 	return class_for_each_device(&wpan_phy_class, NULL,
77 			&wpid, wpan_phy_iter);
78 }
79 EXPORT_SYMBOL(wpan_phy_for_each);
80 
81 struct cfg802154_registered_device *
82 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
83 {
84 	struct cfg802154_registered_device *result = NULL, *rdev;
85 
86 	ASSERT_RTNL();
87 
88 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
89 		if (rdev->wpan_phy_idx == wpan_phy_idx) {
90 			result = rdev;
91 			break;
92 		}
93 	}
94 
95 	return result;
96 }
97 
98 struct wpan_phy *wpan_phy_idx_to_wpan_phy(int wpan_phy_idx)
99 {
100 	struct cfg802154_registered_device *rdev;
101 
102 	ASSERT_RTNL();
103 
104 	rdev = cfg802154_rdev_by_wpan_phy_idx(wpan_phy_idx);
105 	if (!rdev)
106 		return NULL;
107 	return &rdev->wpan_phy;
108 }
109 
110 struct wpan_phy *
111 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
112 {
113 	static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
114 	struct cfg802154_registered_device *rdev;
115 	size_t alloc_size;
116 
117 	alloc_size = sizeof(*rdev) + priv_size;
118 	rdev = kzalloc(alloc_size, GFP_KERNEL);
119 	if (!rdev)
120 		return NULL;
121 
122 	rdev->ops = ops;
123 
124 	rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
125 
126 	if (unlikely(rdev->wpan_phy_idx < 0)) {
127 		/* ugh, wrapped! */
128 		atomic_dec(&wpan_phy_counter);
129 		kfree(rdev);
130 		return NULL;
131 	}
132 
133 	/* atomic_inc_return makes it start at 1, make it start at 0 */
134 	rdev->wpan_phy_idx--;
135 
136 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
137 	device_initialize(&rdev->wpan_phy.dev);
138 	dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
139 
140 	rdev->wpan_phy.dev.class = &wpan_phy_class;
141 	rdev->wpan_phy.dev.platform_data = rdev;
142 
143 	init_waitqueue_head(&rdev->dev_wait);
144 
145 	return &rdev->wpan_phy;
146 }
147 EXPORT_SYMBOL(wpan_phy_new);
148 
149 int wpan_phy_register(struct wpan_phy *phy)
150 {
151 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
152 	int ret;
153 
154 	rtnl_lock();
155 	ret = device_add(&phy->dev);
156 	if (ret) {
157 		rtnl_unlock();
158 		return ret;
159 	}
160 
161 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
162 	cfg802154_rdev_list_generation++;
163 
164 	/* TODO phy registered lock */
165 	rtnl_unlock();
166 
167 	/* TODO nl802154 phy notify */
168 
169 	return 0;
170 }
171 EXPORT_SYMBOL(wpan_phy_register);
172 
173 void wpan_phy_unregister(struct wpan_phy *phy)
174 {
175 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
176 
177 	wait_event(rdev->dev_wait, ({
178 		int __count;
179 		rtnl_lock();
180 		__count = rdev->opencount;
181 		rtnl_unlock();
182 		__count == 0; }));
183 
184 	rtnl_lock();
185 	/* TODO nl802154 phy notify */
186 	/* TODO phy registered lock */
187 
188 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
189 
190 	/* First remove the hardware from everywhere, this makes
191 	 * it impossible to find from userspace.
192 	 */
193 	list_del_rcu(&rdev->list);
194 	synchronize_rcu();
195 
196 	cfg802154_rdev_list_generation++;
197 
198 	device_del(&phy->dev);
199 
200 	rtnl_unlock();
201 }
202 EXPORT_SYMBOL(wpan_phy_unregister);
203 
204 void wpan_phy_free(struct wpan_phy *phy)
205 {
206 	put_device(&phy->dev);
207 }
208 EXPORT_SYMBOL(wpan_phy_free);
209 
210 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
211 {
212 	kfree(rdev);
213 }
214 
215 static void
216 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
217 			   int iftype, int num)
218 {
219 	ASSERT_RTNL();
220 
221 	rdev->num_running_ifaces += num;
222 }
223 
224 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
225 					  unsigned long state, void *ptr)
226 {
227 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
228 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
229 	struct cfg802154_registered_device *rdev;
230 
231 	if (!wpan_dev)
232 		return NOTIFY_DONE;
233 
234 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
235 
236 	/* TODO WARN_ON unspec type */
237 
238 	switch (state) {
239 		/* TODO NETDEV_DEVTYPE */
240 	case NETDEV_REGISTER:
241 		dev->features |= NETIF_F_NETNS_LOCAL;
242 		wpan_dev->identifier = ++rdev->wpan_dev_id;
243 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
244 		rdev->devlist_generation++;
245 
246 		wpan_dev->netdev = dev;
247 		break;
248 	case NETDEV_DOWN:
249 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
250 
251 		rdev->opencount--;
252 		wake_up(&rdev->dev_wait);
253 		break;
254 	case NETDEV_UP:
255 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
256 
257 		rdev->opencount++;
258 		break;
259 	case NETDEV_UNREGISTER:
260 		/* It is possible to get NETDEV_UNREGISTER
261 		 * multiple times. To detect that, check
262 		 * that the interface is still on the list
263 		 * of registered interfaces, and only then
264 		 * remove and clean it up.
265 		 */
266 		if (!list_empty(&wpan_dev->list)) {
267 			list_del_rcu(&wpan_dev->list);
268 			rdev->devlist_generation++;
269 		}
270 		/* synchronize (so that we won't find this netdev
271 		 * from other code any more) and then clear the list
272 		 * head so that the above code can safely check for
273 		 * !list_empty() to avoid double-cleanup.
274 		 */
275 		synchronize_rcu();
276 		INIT_LIST_HEAD(&wpan_dev->list);
277 		break;
278 	default:
279 		return NOTIFY_DONE;
280 	}
281 
282 	return NOTIFY_OK;
283 }
284 
285 static struct notifier_block cfg802154_netdev_notifier = {
286 	.notifier_call = cfg802154_netdev_notifier_call,
287 };
288 
289 static int __init wpan_phy_class_init(void)
290 {
291 	int rc;
292 
293 	rc = wpan_phy_sysfs_init();
294 	if (rc)
295 		goto err;
296 
297 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
298 	if (rc)
299 		goto err_nl;
300 
301 	rc = ieee802154_nl_init();
302 	if (rc)
303 		goto err_notifier;
304 
305 	rc = nl802154_init();
306 	if (rc)
307 		goto err_ieee802154_nl;
308 
309 	return 0;
310 
311 err_ieee802154_nl:
312 	ieee802154_nl_exit();
313 
314 err_notifier:
315 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
316 err_nl:
317 	wpan_phy_sysfs_exit();
318 err:
319 	return rc;
320 }
321 subsys_initcall(wpan_phy_class_init);
322 
323 static void __exit wpan_phy_class_exit(void)
324 {
325 	nl802154_exit();
326 	ieee802154_nl_exit();
327 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
328 	wpan_phy_sysfs_exit();
329 }
330 module_exit(wpan_phy_class_exit);
331 
332 MODULE_LICENSE("GPL v2");
333 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
334 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
335 
336