xref: /openbmc/linux/net/ieee802154/core.c (revision b96fc2f3)
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 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
125 	device_initialize(&rdev->wpan_phy.dev);
126 	dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
127 
128 	rdev->wpan_phy.dev.class = &wpan_phy_class;
129 	rdev->wpan_phy.dev.platform_data = rdev;
130 
131 	init_waitqueue_head(&rdev->dev_wait);
132 
133 	return &rdev->wpan_phy;
134 }
135 EXPORT_SYMBOL(wpan_phy_new);
136 
137 int wpan_phy_register(struct wpan_phy *phy)
138 {
139 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
140 	int ret;
141 
142 	rtnl_lock();
143 	ret = device_add(&phy->dev);
144 	if (ret) {
145 		rtnl_unlock();
146 		return ret;
147 	}
148 
149 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
150 	cfg802154_rdev_list_generation++;
151 
152 	/* TODO phy registered lock */
153 	rtnl_unlock();
154 
155 	/* TODO nl802154 phy notify */
156 
157 	return 0;
158 }
159 EXPORT_SYMBOL(wpan_phy_register);
160 
161 void wpan_phy_unregister(struct wpan_phy *phy)
162 {
163 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
164 
165 	wait_event(rdev->dev_wait, ({
166 		int __count;
167 		rtnl_lock();
168 		__count = rdev->opencount;
169 		rtnl_unlock();
170 		__count == 0; }));
171 
172 	rtnl_lock();
173 	/* TODO nl802154 phy notify */
174 	/* TODO phy registered lock */
175 
176 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
177 
178 	/* First remove the hardware from everywhere, this makes
179 	 * it impossible to find from userspace.
180 	 */
181 	list_del_rcu(&rdev->list);
182 	synchronize_rcu();
183 
184 	cfg802154_rdev_list_generation++;
185 
186 	device_del(&phy->dev);
187 
188 	rtnl_unlock();
189 }
190 EXPORT_SYMBOL(wpan_phy_unregister);
191 
192 void wpan_phy_free(struct wpan_phy *phy)
193 {
194 	put_device(&phy->dev);
195 }
196 EXPORT_SYMBOL(wpan_phy_free);
197 
198 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
199 {
200 	kfree(rdev);
201 }
202 
203 static void
204 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
205 			   int iftype, int num)
206 {
207 	ASSERT_RTNL();
208 
209 	rdev->num_running_ifaces += num;
210 }
211 
212 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
213 					  unsigned long state, void *ptr)
214 {
215 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
216 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
217 	struct cfg802154_registered_device *rdev;
218 
219 	if (!wpan_dev)
220 		return NOTIFY_DONE;
221 
222 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
223 
224 	/* TODO WARN_ON unspec type */
225 
226 	switch (state) {
227 		/* TODO NETDEV_DEVTYPE */
228 	case NETDEV_REGISTER:
229 		dev->features |= NETIF_F_NETNS_LOCAL;
230 		wpan_dev->identifier = ++rdev->wpan_dev_id;
231 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
232 		rdev->devlist_generation++;
233 
234 		wpan_dev->netdev = dev;
235 		break;
236 	case NETDEV_DOWN:
237 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
238 
239 		rdev->opencount--;
240 		wake_up(&rdev->dev_wait);
241 		break;
242 	case NETDEV_UP:
243 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
244 
245 		rdev->opencount++;
246 		break;
247 	case NETDEV_UNREGISTER:
248 		/* It is possible to get NETDEV_UNREGISTER
249 		 * multiple times. To detect that, check
250 		 * that the interface is still on the list
251 		 * of registered interfaces, and only then
252 		 * remove and clean it up.
253 		 */
254 		if (!list_empty(&wpan_dev->list)) {
255 			list_del_rcu(&wpan_dev->list);
256 			rdev->devlist_generation++;
257 		}
258 		/* synchronize (so that we won't find this netdev
259 		 * from other code any more) and then clear the list
260 		 * head so that the above code can safely check for
261 		 * !list_empty() to avoid double-cleanup.
262 		 */
263 		synchronize_rcu();
264 		INIT_LIST_HEAD(&wpan_dev->list);
265 		break;
266 	default:
267 		return NOTIFY_DONE;
268 	}
269 
270 	return NOTIFY_OK;
271 }
272 
273 static struct notifier_block cfg802154_netdev_notifier = {
274 	.notifier_call = cfg802154_netdev_notifier_call,
275 };
276 
277 static int __init wpan_phy_class_init(void)
278 {
279 	int rc;
280 
281 	rc = wpan_phy_sysfs_init();
282 	if (rc)
283 		goto err;
284 
285 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
286 	if (rc)
287 		goto err_nl;
288 
289 	rc = ieee802154_nl_init();
290 	if (rc)
291 		goto err_notifier;
292 
293 	rc = nl802154_init();
294 	if (rc)
295 		goto err_ieee802154_nl;
296 
297 	return 0;
298 
299 err_ieee802154_nl:
300 	ieee802154_nl_exit();
301 
302 err_notifier:
303 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
304 err_nl:
305 	wpan_phy_sysfs_exit();
306 err:
307 	return rc;
308 }
309 subsys_initcall(wpan_phy_class_init);
310 
311 static void __exit wpan_phy_class_exit(void)
312 {
313 	nl802154_exit();
314 	ieee802154_nl_exit();
315 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
316 	wpan_phy_sysfs_exit();
317 }
318 module_exit(wpan_phy_class_exit);
319 
320 MODULE_LICENSE("GPL v2");
321 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
322 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
323 
324