xref: /openbmc/linux/net/ieee802154/core.c (revision 4bce6fce)
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 *
99 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
100 {
101 	static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
102 	struct cfg802154_registered_device *rdev;
103 	size_t alloc_size;
104 
105 	alloc_size = sizeof(*rdev) + priv_size;
106 	rdev = kzalloc(alloc_size, GFP_KERNEL);
107 	if (!rdev)
108 		return NULL;
109 
110 	rdev->ops = ops;
111 
112 	rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
113 
114 	if (unlikely(rdev->wpan_phy_idx < 0)) {
115 		/* ugh, wrapped! */
116 		atomic_dec(&wpan_phy_counter);
117 		kfree(rdev);
118 		return NULL;
119 	}
120 
121 	/* atomic_inc_return makes it start at 1, make it start at 0 */
122 	rdev->wpan_phy_idx--;
123 
124 	mutex_init(&rdev->wpan_phy.pib_lock);
125 
126 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
127 	device_initialize(&rdev->wpan_phy.dev);
128 	dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
129 
130 	rdev->wpan_phy.dev.class = &wpan_phy_class;
131 	rdev->wpan_phy.dev.platform_data = rdev;
132 
133 	init_waitqueue_head(&rdev->dev_wait);
134 
135 	return &rdev->wpan_phy;
136 }
137 EXPORT_SYMBOL(wpan_phy_new);
138 
139 int wpan_phy_register(struct wpan_phy *phy)
140 {
141 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
142 	int ret;
143 
144 	rtnl_lock();
145 	ret = device_add(&phy->dev);
146 	if (ret) {
147 		rtnl_unlock();
148 		return ret;
149 	}
150 
151 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
152 	cfg802154_rdev_list_generation++;
153 
154 	/* TODO phy registered lock */
155 	rtnl_unlock();
156 
157 	/* TODO nl802154 phy notify */
158 
159 	return 0;
160 }
161 EXPORT_SYMBOL(wpan_phy_register);
162 
163 void wpan_phy_unregister(struct wpan_phy *phy)
164 {
165 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
166 
167 	wait_event(rdev->dev_wait, ({
168 		int __count;
169 		rtnl_lock();
170 		__count = rdev->opencount;
171 		rtnl_unlock();
172 		__count == 0; }));
173 
174 	rtnl_lock();
175 	/* TODO nl802154 phy notify */
176 	/* TODO phy registered lock */
177 
178 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
179 
180 	/* First remove the hardware from everywhere, this makes
181 	 * it impossible to find from userspace.
182 	 */
183 	list_del_rcu(&rdev->list);
184 	synchronize_rcu();
185 
186 	cfg802154_rdev_list_generation++;
187 
188 	device_del(&phy->dev);
189 
190 	rtnl_unlock();
191 }
192 EXPORT_SYMBOL(wpan_phy_unregister);
193 
194 void wpan_phy_free(struct wpan_phy *phy)
195 {
196 	put_device(&phy->dev);
197 }
198 EXPORT_SYMBOL(wpan_phy_free);
199 
200 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
201 {
202 	kfree(rdev);
203 }
204 
205 static void
206 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
207 			   int iftype, int num)
208 {
209 	ASSERT_RTNL();
210 
211 	rdev->num_running_ifaces += num;
212 }
213 
214 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
215 					  unsigned long state, void *ptr)
216 {
217 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
218 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
219 	struct cfg802154_registered_device *rdev;
220 
221 	if (!wpan_dev)
222 		return NOTIFY_DONE;
223 
224 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
225 
226 	/* TODO WARN_ON unspec type */
227 
228 	switch (state) {
229 		/* TODO NETDEV_DEVTYPE */
230 	case NETDEV_REGISTER:
231 		dev->features |= NETIF_F_NETNS_LOCAL;
232 		wpan_dev->identifier = ++rdev->wpan_dev_id;
233 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
234 		rdev->devlist_generation++;
235 
236 		wpan_dev->netdev = dev;
237 		break;
238 	case NETDEV_DOWN:
239 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
240 
241 		rdev->opencount--;
242 		wake_up(&rdev->dev_wait);
243 		break;
244 	case NETDEV_UP:
245 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
246 
247 		rdev->opencount++;
248 		break;
249 	case NETDEV_UNREGISTER:
250 		/* It is possible to get NETDEV_UNREGISTER
251 		 * multiple times. To detect that, check
252 		 * that the interface is still on the list
253 		 * of registered interfaces, and only then
254 		 * remove and clean it up.
255 		 */
256 		if (!list_empty(&wpan_dev->list)) {
257 			list_del_rcu(&wpan_dev->list);
258 			rdev->devlist_generation++;
259 		}
260 		/* synchronize (so that we won't find this netdev
261 		 * from other code any more) and then clear the list
262 		 * head so that the above code can safely check for
263 		 * !list_empty() to avoid double-cleanup.
264 		 */
265 		synchronize_rcu();
266 		INIT_LIST_HEAD(&wpan_dev->list);
267 		break;
268 	default:
269 		return NOTIFY_DONE;
270 	}
271 
272 	return NOTIFY_OK;
273 }
274 
275 static struct notifier_block cfg802154_netdev_notifier = {
276 	.notifier_call = cfg802154_netdev_notifier_call,
277 };
278 
279 static int __init wpan_phy_class_init(void)
280 {
281 	int rc;
282 
283 	rc = wpan_phy_sysfs_init();
284 	if (rc)
285 		goto err;
286 
287 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
288 	if (rc)
289 		goto err_nl;
290 
291 	rc = ieee802154_nl_init();
292 	if (rc)
293 		goto err_notifier;
294 
295 	rc = nl802154_init();
296 	if (rc)
297 		goto err_ieee802154_nl;
298 
299 	return 0;
300 
301 err_ieee802154_nl:
302 	ieee802154_nl_exit();
303 
304 err_notifier:
305 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
306 err_nl:
307 	wpan_phy_sysfs_exit();
308 err:
309 	return rc;
310 }
311 subsys_initcall(wpan_phy_class_init);
312 
313 static void __exit wpan_phy_class_exit(void)
314 {
315 	nl802154_exit();
316 	ieee802154_nl_exit();
317 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
318 	wpan_phy_sysfs_exit();
319 }
320 module_exit(wpan_phy_class_exit);
321 
322 MODULE_LICENSE("GPL v2");
323 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
324 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
325 
326