net/caif/cfrfml.c: use asm/unaligned.h
[linux-2.6.git] / net / caif / caif_dev.c
1 /*
2  * CAIF Interface registration.
3  * Copyright (C) ST-Ericsson AB 2010
4  * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
5  * License terms: GNU General Public License (GPL) version 2
6  *
7  * Borrowed heavily from file: pn_dev.c. Thanks to
8  *  Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9  *  and Sakari Ailus <sakari.ailus@nokia.com>
10  */
11
12 #include <linux/version.h>
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/if_arp.h>
16 #include <linux/net.h>
17 #include <linux/netdevice.h>
18 #include <linux/skbuff.h>
19 #include <linux/sched.h>
20 #include <linux/wait.h>
21 #include <net/netns/generic.h>
22 #include <net/net_namespace.h>
23 #include <net/pkt_sched.h>
24 #include <net/caif/caif_device.h>
25 #include <net/caif/caif_dev.h>
26 #include <net/caif/caif_layer.h>
27 #include <net/caif/cfpkt.h>
28 #include <net/caif/cfcnfg.h>
29
30 MODULE_LICENSE("GPL");
31 #define TIMEOUT (HZ*5)
32
33 /* Used for local tracking of the CAIF net devices */
34 struct caif_device_entry {
35         struct cflayer layer;
36         struct list_head list;
37         atomic_t in_use;
38         atomic_t state;
39         u16 phyid;
40         struct net_device *netdev;
41         wait_queue_head_t event;
42 };
43
44 struct caif_device_entry_list {
45         struct list_head list;
46         /* Protects simulanous deletes in list */
47         spinlock_t lock;
48 };
49
50 struct caif_net {
51         struct caif_device_entry_list caifdevs;
52 };
53
54 static int caif_net_id;
55 static struct cfcnfg *cfg;
56
57 static struct caif_device_entry_list *caif_device_list(struct net *net)
58 {
59         struct caif_net *caifn;
60         BUG_ON(!net);
61         caifn = net_generic(net, caif_net_id);
62         BUG_ON(!caifn);
63         return &caifn->caifdevs;
64 }
65
66 /* Allocate new CAIF device. */
67 static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
68 {
69         struct caif_device_entry_list *caifdevs;
70         struct caif_device_entry *caifd;
71         caifdevs = caif_device_list(dev_net(dev));
72         BUG_ON(!caifdevs);
73         caifd = kzalloc(sizeof(*caifd), GFP_ATOMIC);
74         if (!caifd)
75                 return NULL;
76         caifd->netdev = dev;
77         list_add(&caifd->list, &caifdevs->list);
78         init_waitqueue_head(&caifd->event);
79         return caifd;
80 }
81
82 static struct caif_device_entry *caif_get(struct net_device *dev)
83 {
84         struct caif_device_entry_list *caifdevs =
85             caif_device_list(dev_net(dev));
86         struct caif_device_entry *caifd;
87         BUG_ON(!caifdevs);
88         list_for_each_entry(caifd, &caifdevs->list, list) {
89                 if (caifd->netdev == dev)
90                         return caifd;
91         }
92         return NULL;
93 }
94
95 static void caif_device_destroy(struct net_device *dev)
96 {
97         struct caif_device_entry_list *caifdevs =
98             caif_device_list(dev_net(dev));
99         struct caif_device_entry *caifd;
100         ASSERT_RTNL();
101         if (dev->type != ARPHRD_CAIF)
102                 return;
103
104         spin_lock_bh(&caifdevs->lock);
105         caifd = caif_get(dev);
106         if (caifd == NULL) {
107                 spin_unlock_bh(&caifdevs->lock);
108                 return;
109         }
110
111         list_del(&caifd->list);
112         spin_unlock_bh(&caifdevs->lock);
113
114         kfree(caifd);
115 }
116
117 static int transmit(struct cflayer *layer, struct cfpkt *pkt)
118 {
119         struct caif_device_entry *caifd =
120             container_of(layer, struct caif_device_entry, layer);
121         struct sk_buff *skb, *skb2;
122         int ret = -EINVAL;
123         skb = cfpkt_tonative(pkt);
124         skb->dev = caifd->netdev;
125         /*
126          * Don't allow SKB to be destroyed upon error, but signal resend
127          * notification to clients. We can't rely on the return value as
128          * congestion (NET_XMIT_CN) sometimes drops the packet, sometimes don't.
129          */
130         if (netif_queue_stopped(caifd->netdev))
131                 return -EAGAIN;
132         skb2 = skb_get(skb);
133
134         ret = dev_queue_xmit(skb2);
135
136         if (!ret)
137                 kfree_skb(skb);
138         else
139                 return -EAGAIN;
140
141         return 0;
142 }
143
144 static int modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
145 {
146         struct caif_device_entry *caifd;
147         struct caif_dev_common *caifdev;
148         caifd = container_of(layr, struct caif_device_entry, layer);
149         caifdev = netdev_priv(caifd->netdev);
150         if (ctrl == _CAIF_MODEMCMD_PHYIF_USEFULL) {
151                 atomic_set(&caifd->in_use, 1);
152                 wake_up_interruptible(&caifd->event);
153
154         } else if (ctrl == _CAIF_MODEMCMD_PHYIF_USELESS) {
155                 atomic_set(&caifd->in_use, 0);
156                 wake_up_interruptible(&caifd->event);
157         }
158         return 0;
159 }
160
161 /*
162  * Stuff received packets to associated sockets.
163  * On error, returns non-zero and releases the skb.
164  */
165 static int receive(struct sk_buff *skb, struct net_device *dev,
166                    struct packet_type *pkttype, struct net_device *orig_dev)
167 {
168         struct net *net;
169         struct cfpkt *pkt;
170         struct caif_device_entry *caifd;
171         net = dev_net(dev);
172         pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
173         caifd = caif_get(dev);
174         if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
175                 return NET_RX_DROP;
176
177         if (caifd->layer.up->receive(caifd->layer.up, pkt))
178                 return NET_RX_DROP;
179
180         return 0;
181 }
182
183 static struct packet_type caif_packet_type __read_mostly = {
184         .type = cpu_to_be16(ETH_P_CAIF),
185         .func = receive,
186 };
187
188 static void dev_flowctrl(struct net_device *dev, int on)
189 {
190         struct caif_device_entry *caifd = caif_get(dev);
191         if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
192                 return;
193
194         caifd->layer.up->ctrlcmd(caifd->layer.up,
195                                  on ?
196                                  _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
197                                  _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
198                                  caifd->layer.id);
199 }
200
201 /* notify Caif of device events */
202 static int caif_device_notify(struct notifier_block *me, unsigned long what,
203                               void *arg)
204 {
205         struct net_device *dev = arg;
206         struct caif_device_entry *caifd = NULL;
207         struct caif_dev_common *caifdev;
208         enum cfcnfg_phy_preference pref;
209         int res = -EINVAL;
210         enum cfcnfg_phy_type phy_type;
211
212         if (dev->type != ARPHRD_CAIF)
213                 return 0;
214
215         switch (what) {
216         case NETDEV_REGISTER:
217                 pr_info("CAIF: %s():register %s\n", __func__, dev->name);
218                 caifd = caif_device_alloc(dev);
219                 if (caifd == NULL)
220                         break;
221                 caifdev = netdev_priv(dev);
222                 caifdev->flowctrl = dev_flowctrl;
223                 atomic_set(&caifd->state, what);
224                 res = 0;
225                 break;
226
227         case NETDEV_UP:
228                 pr_info("CAIF: %s(): up %s\n", __func__, dev->name);
229                 caifd = caif_get(dev);
230                 if (caifd == NULL)
231                         break;
232                 caifdev = netdev_priv(dev);
233                 if (atomic_read(&caifd->state) == NETDEV_UP) {
234                         pr_info("CAIF: %s():%s already up\n",
235                                 __func__, dev->name);
236                         break;
237                 }
238                 atomic_set(&caifd->state, what);
239                 caifd->layer.transmit = transmit;
240                 caifd->layer.modemcmd = modemcmd;
241
242                 if (caifdev->use_frag)
243                         phy_type = CFPHYTYPE_FRAG;
244                 else
245                         phy_type = CFPHYTYPE_CAIF;
246
247                 switch (caifdev->link_select) {
248                 case CAIF_LINK_HIGH_BANDW:
249                         pref = CFPHYPREF_HIGH_BW;
250                         break;
251                 case CAIF_LINK_LOW_LATENCY:
252                         pref = CFPHYPREF_LOW_LAT;
253                         break;
254                 default:
255                         pref = CFPHYPREF_HIGH_BW;
256                         break;
257                 }
258                 dev_hold(dev);
259                 cfcnfg_add_phy_layer(get_caif_conf(),
260                                      phy_type,
261                                      dev,
262                                      &caifd->layer,
263                                      &caifd->phyid,
264                                      pref,
265                                      caifdev->use_fcs,
266                                      caifdev->use_stx);
267                 strncpy(caifd->layer.name, dev->name,
268                         sizeof(caifd->layer.name) - 1);
269                 caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
270                 break;
271
272         case NETDEV_GOING_DOWN:
273                 caifd = caif_get(dev);
274                 if (caifd == NULL)
275                         break;
276                 pr_info("CAIF: %s():going down %s\n", __func__, dev->name);
277
278                 if (atomic_read(&caifd->state) == NETDEV_GOING_DOWN ||
279                         atomic_read(&caifd->state) == NETDEV_DOWN)
280                         break;
281
282                 atomic_set(&caifd->state, what);
283                 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
284                         return -EINVAL;
285                 caifd->layer.up->ctrlcmd(caifd->layer.up,
286                                          _CAIF_CTRLCMD_PHYIF_DOWN_IND,
287                                          caifd->layer.id);
288                 might_sleep();
289                 res = wait_event_interruptible_timeout(caifd->event,
290                                         atomic_read(&caifd->in_use) == 0,
291                                         TIMEOUT);
292                 break;
293
294         case NETDEV_DOWN:
295                 caifd = caif_get(dev);
296                 if (caifd == NULL)
297                         break;
298                 pr_info("CAIF: %s(): down %s\n", __func__, dev->name);
299                 if (atomic_read(&caifd->in_use))
300                         pr_warning("CAIF: %s(): "
301                                    "Unregistering an active CAIF device: %s\n",
302                                    __func__, dev->name);
303                 cfcnfg_del_phy_layer(get_caif_conf(), &caifd->layer);
304                 dev_put(dev);
305                 atomic_set(&caifd->state, what);
306                 break;
307
308         case NETDEV_UNREGISTER:
309                 caifd = caif_get(dev);
310                 pr_info("CAIF: %s(): unregister %s\n", __func__, dev->name);
311                 atomic_set(&caifd->state, what);
312                 caif_device_destroy(dev);
313                 break;
314         }
315         return 0;
316 }
317
318 static struct notifier_block caif_device_notifier = {
319         .notifier_call = caif_device_notify,
320         .priority = 0,
321 };
322
323
324 struct cfcnfg *get_caif_conf(void)
325 {
326         return cfg;
327 }
328 EXPORT_SYMBOL(get_caif_conf);
329
330 int caif_connect_client(struct caif_connect_request *conn_req,
331                         struct cflayer *client_layer, int *ifindex,
332                         int *headroom, int *tailroom)
333 {
334         struct cfctrl_link_param param;
335         int ret;
336         ret = connect_req_to_link_param(get_caif_conf(), conn_req, &param);
337         if (ret)
338                 return ret;
339         /* Hook up the adaptation layer. */
340         return cfcnfg_add_adaptation_layer(get_caif_conf(), &param,
341                                         client_layer, ifindex,
342                                         headroom, tailroom);
343 }
344 EXPORT_SYMBOL(caif_connect_client);
345
346 int caif_disconnect_client(struct cflayer *adap_layer)
347 {
348        return cfcnfg_disconn_adapt_layer(get_caif_conf(), adap_layer);
349 }
350 EXPORT_SYMBOL(caif_disconnect_client);
351
352 void caif_release_client(struct cflayer *adap_layer)
353 {
354        cfcnfg_release_adap_layer(adap_layer);
355 }
356 EXPORT_SYMBOL(caif_release_client);
357
358 /* Per-namespace Caif devices handling */
359 static int caif_init_net(struct net *net)
360 {
361         struct caif_net *caifn = net_generic(net, caif_net_id);
362         INIT_LIST_HEAD(&caifn->caifdevs.list);
363         spin_lock_init(&caifn->caifdevs.lock);
364         return 0;
365 }
366
367 static void caif_exit_net(struct net *net)
368 {
369         struct net_device *dev;
370         int res;
371         rtnl_lock();
372         for_each_netdev(net, dev) {
373                 if (dev->type != ARPHRD_CAIF)
374                         continue;
375                 res = dev_close(dev);
376                 caif_device_destroy(dev);
377         }
378         rtnl_unlock();
379 }
380
381 static struct pernet_operations caif_net_ops = {
382         .init = caif_init_net,
383         .exit = caif_exit_net,
384         .id   = &caif_net_id,
385         .size = sizeof(struct caif_net),
386 };
387
388 /* Initialize Caif devices list */
389 static int __init caif_device_init(void)
390 {
391         int result;
392         cfg = cfcnfg_create();
393         if (!cfg) {
394                 pr_warning("CAIF: %s(): can't create cfcnfg.\n", __func__);
395                 goto err_cfcnfg_create_failed;
396         }
397         result = register_pernet_device(&caif_net_ops);
398
399         if (result) {
400                 kfree(cfg);
401                 cfg = NULL;
402                 return result;
403         }
404         dev_add_pack(&caif_packet_type);
405         register_netdevice_notifier(&caif_device_notifier);
406
407         return result;
408 err_cfcnfg_create_failed:
409         return -ENODEV;
410 }
411
412 static void __exit caif_device_exit(void)
413 {
414         dev_remove_pack(&caif_packet_type);
415         unregister_pernet_device(&caif_net_ops);
416         unregister_netdevice_notifier(&caif_device_notifier);
417         cfcnfg_remove(cfg);
418 }
419
420 module_init(caif_device_init);
421 module_exit(caif_device_exit);