net/caif: Use pr_fmt
[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 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
13
14 #include <linux/version.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/if_arp.h>
18 #include <linux/net.h>
19 #include <linux/netdevice.h>
20 #include <linux/skbuff.h>
21 #include <linux/sched.h>
22 #include <linux/wait.h>
23 #include <net/netns/generic.h>
24 #include <net/net_namespace.h>
25 #include <net/pkt_sched.h>
26 #include <net/caif/caif_device.h>
27 #include <net/caif/caif_dev.h>
28 #include <net/caif/caif_layer.h>
29 #include <net/caif/cfpkt.h>
30 #include <net/caif/cfcnfg.h>
31
32 MODULE_LICENSE("GPL");
33 #define TIMEOUT (HZ*5)
34
35 /* Used for local tracking of the CAIF net devices */
36 struct caif_device_entry {
37         struct cflayer layer;
38         struct list_head list;
39         atomic_t in_use;
40         atomic_t state;
41         u16 phyid;
42         struct net_device *netdev;
43         wait_queue_head_t event;
44 };
45
46 struct caif_device_entry_list {
47         struct list_head list;
48         /* Protects simulanous deletes in list */
49         spinlock_t lock;
50 };
51
52 struct caif_net {
53         struct caif_device_entry_list caifdevs;
54 };
55
56 static int caif_net_id;
57 static struct cfcnfg *cfg;
58
59 static struct caif_device_entry_list *caif_device_list(struct net *net)
60 {
61         struct caif_net *caifn;
62         BUG_ON(!net);
63         caifn = net_generic(net, caif_net_id);
64         BUG_ON(!caifn);
65         return &caifn->caifdevs;
66 }
67
68 /* Allocate new CAIF device. */
69 static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
70 {
71         struct caif_device_entry_list *caifdevs;
72         struct caif_device_entry *caifd;
73         caifdevs = caif_device_list(dev_net(dev));
74         BUG_ON(!caifdevs);
75         caifd = kzalloc(sizeof(*caifd), GFP_ATOMIC);
76         if (!caifd)
77                 return NULL;
78         caifd->netdev = dev;
79         list_add(&caifd->list, &caifdevs->list);
80         init_waitqueue_head(&caifd->event);
81         return caifd;
82 }
83
84 static struct caif_device_entry *caif_get(struct net_device *dev)
85 {
86         struct caif_device_entry_list *caifdevs =
87             caif_device_list(dev_net(dev));
88         struct caif_device_entry *caifd;
89         BUG_ON(!caifdevs);
90         list_for_each_entry(caifd, &caifdevs->list, list) {
91                 if (caifd->netdev == dev)
92                         return caifd;
93         }
94         return NULL;
95 }
96
97 static void caif_device_destroy(struct net_device *dev)
98 {
99         struct caif_device_entry_list *caifdevs =
100             caif_device_list(dev_net(dev));
101         struct caif_device_entry *caifd;
102         ASSERT_RTNL();
103         if (dev->type != ARPHRD_CAIF)
104                 return;
105
106         spin_lock_bh(&caifdevs->lock);
107         caifd = caif_get(dev);
108         if (caifd == NULL) {
109                 spin_unlock_bh(&caifdevs->lock);
110                 return;
111         }
112
113         list_del(&caifd->list);
114         spin_unlock_bh(&caifdevs->lock);
115
116         kfree(caifd);
117 }
118
119 static int transmit(struct cflayer *layer, struct cfpkt *pkt)
120 {
121         struct caif_device_entry *caifd =
122             container_of(layer, struct caif_device_entry, layer);
123         struct sk_buff *skb, *skb2;
124         int ret = -EINVAL;
125         skb = cfpkt_tonative(pkt);
126         skb->dev = caifd->netdev;
127         /*
128          * Don't allow SKB to be destroyed upon error, but signal resend
129          * notification to clients. We can't rely on the return value as
130          * congestion (NET_XMIT_CN) sometimes drops the packet, sometimes don't.
131          */
132         if (netif_queue_stopped(caifd->netdev))
133                 return -EAGAIN;
134         skb2 = skb_get(skb);
135
136         ret = dev_queue_xmit(skb2);
137
138         if (!ret)
139                 kfree_skb(skb);
140         else
141                 return -EAGAIN;
142
143         return 0;
144 }
145
146 static int modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
147 {
148         struct caif_device_entry *caifd;
149         struct caif_dev_common *caifdev;
150         caifd = container_of(layr, struct caif_device_entry, layer);
151         caifdev = netdev_priv(caifd->netdev);
152         if (ctrl == _CAIF_MODEMCMD_PHYIF_USEFULL) {
153                 atomic_set(&caifd->in_use, 1);
154                 wake_up_interruptible(&caifd->event);
155
156         } else if (ctrl == _CAIF_MODEMCMD_PHYIF_USELESS) {
157                 atomic_set(&caifd->in_use, 0);
158                 wake_up_interruptible(&caifd->event);
159         }
160         return 0;
161 }
162
163 /*
164  * Stuff received packets to associated sockets.
165  * On error, returns non-zero and releases the skb.
166  */
167 static int receive(struct sk_buff *skb, struct net_device *dev,
168                    struct packet_type *pkttype, struct net_device *orig_dev)
169 {
170         struct net *net;
171         struct cfpkt *pkt;
172         struct caif_device_entry *caifd;
173         net = dev_net(dev);
174         pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
175         caifd = caif_get(dev);
176         if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
177                 return NET_RX_DROP;
178
179         if (caifd->layer.up->receive(caifd->layer.up, pkt))
180                 return NET_RX_DROP;
181
182         return 0;
183 }
184
185 static struct packet_type caif_packet_type __read_mostly = {
186         .type = cpu_to_be16(ETH_P_CAIF),
187         .func = receive,
188 };
189
190 static void dev_flowctrl(struct net_device *dev, int on)
191 {
192         struct caif_device_entry *caifd = caif_get(dev);
193         if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
194                 return;
195
196         caifd->layer.up->ctrlcmd(caifd->layer.up,
197                                  on ?
198                                  _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
199                                  _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
200                                  caifd->layer.id);
201 }
202
203 /* notify Caif of device events */
204 static int caif_device_notify(struct notifier_block *me, unsigned long what,
205                               void *arg)
206 {
207         struct net_device *dev = arg;
208         struct caif_device_entry *caifd = NULL;
209         struct caif_dev_common *caifdev;
210         enum cfcnfg_phy_preference pref;
211         int res = -EINVAL;
212         enum cfcnfg_phy_type phy_type;
213
214         if (dev->type != ARPHRD_CAIF)
215                 return 0;
216
217         switch (what) {
218         case NETDEV_REGISTER:
219                 pr_info("register %s\n", dev->name);
220                 caifd = caif_device_alloc(dev);
221                 if (caifd == NULL)
222                         break;
223                 caifdev = netdev_priv(dev);
224                 caifdev->flowctrl = dev_flowctrl;
225                 atomic_set(&caifd->state, what);
226                 res = 0;
227                 break;
228
229         case NETDEV_UP:
230                 pr_info("up %s\n", dev->name);
231                 caifd = caif_get(dev);
232                 if (caifd == NULL)
233                         break;
234                 caifdev = netdev_priv(dev);
235                 if (atomic_read(&caifd->state) == NETDEV_UP) {
236                         pr_info("%s already up\n", dev->name);
237                         break;
238                 }
239                 atomic_set(&caifd->state, what);
240                 caifd->layer.transmit = transmit;
241                 caifd->layer.modemcmd = modemcmd;
242
243                 if (caifdev->use_frag)
244                         phy_type = CFPHYTYPE_FRAG;
245                 else
246                         phy_type = CFPHYTYPE_CAIF;
247
248                 switch (caifdev->link_select) {
249                 case CAIF_LINK_HIGH_BANDW:
250                         pref = CFPHYPREF_HIGH_BW;
251                         break;
252                 case CAIF_LINK_LOW_LATENCY:
253                         pref = CFPHYPREF_LOW_LAT;
254                         break;
255                 default:
256                         pref = CFPHYPREF_HIGH_BW;
257                         break;
258                 }
259                 dev_hold(dev);
260                 cfcnfg_add_phy_layer(get_caif_conf(),
261                                      phy_type,
262                                      dev,
263                                      &caifd->layer,
264                                      &caifd->phyid,
265                                      pref,
266                                      caifdev->use_fcs,
267                                      caifdev->use_stx);
268                 strncpy(caifd->layer.name, dev->name,
269                         sizeof(caifd->layer.name) - 1);
270                 caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
271                 break;
272
273         case NETDEV_GOING_DOWN:
274                 caifd = caif_get(dev);
275                 if (caifd == NULL)
276                         break;
277                 pr_info("going down %s\n", dev->name);
278
279                 if (atomic_read(&caifd->state) == NETDEV_GOING_DOWN ||
280                         atomic_read(&caifd->state) == NETDEV_DOWN)
281                         break;
282
283                 atomic_set(&caifd->state, what);
284                 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
285                         return -EINVAL;
286                 caifd->layer.up->ctrlcmd(caifd->layer.up,
287                                          _CAIF_CTRLCMD_PHYIF_DOWN_IND,
288                                          caifd->layer.id);
289                 might_sleep();
290                 res = wait_event_interruptible_timeout(caifd->event,
291                                         atomic_read(&caifd->in_use) == 0,
292                                         TIMEOUT);
293                 break;
294
295         case NETDEV_DOWN:
296                 caifd = caif_get(dev);
297                 if (caifd == NULL)
298                         break;
299                 pr_info("down %s\n", dev->name);
300                 if (atomic_read(&caifd->in_use))
301                         pr_warn("Unregistering an active CAIF device: %s\n",
302                                 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("unregister %s\n", 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_warn("can't create cfcnfg\n");
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);