Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-btrfs-devel.git] / net / caif / caif_dev.c
blob47fc8f3a47cf237af78fbe4483fac7da0f2108ad
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
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>
12 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
14 #include <linux/kernel.h>
15 #include <linux/if_arp.h>
16 #include <linux/net.h>
17 #include <linux/netdevice.h>
18 #include <linux/mutex.h>
19 #include <net/netns/generic.h>
20 #include <net/net_namespace.h>
21 #include <net/pkt_sched.h>
22 #include <net/caif/caif_device.h>
23 #include <net/caif/caif_layer.h>
24 #include <net/caif/cfpkt.h>
25 #include <net/caif/cfcnfg.h>
27 MODULE_LICENSE("GPL");
29 /* Used for local tracking of the CAIF net devices */
30 struct caif_device_entry {
31 struct cflayer layer;
32 struct list_head list;
33 struct net_device *netdev;
34 int __percpu *pcpu_refcnt;
37 struct caif_device_entry_list {
38 struct list_head list;
39 /* Protects simulanous deletes in list */
40 struct mutex lock;
43 struct caif_net {
44 struct cfcnfg *cfg;
45 struct caif_device_entry_list caifdevs;
48 static int caif_net_id;
50 struct cfcnfg *get_cfcnfg(struct net *net)
52 struct caif_net *caifn;
53 BUG_ON(!net);
54 caifn = net_generic(net, caif_net_id);
55 BUG_ON(!caifn);
56 return caifn->cfg;
58 EXPORT_SYMBOL(get_cfcnfg);
60 static struct caif_device_entry_list *caif_device_list(struct net *net)
62 struct caif_net *caifn;
63 BUG_ON(!net);
64 caifn = net_generic(net, caif_net_id);
65 BUG_ON(!caifn);
66 return &caifn->caifdevs;
69 static void caifd_put(struct caif_device_entry *e)
71 irqsafe_cpu_dec(*e->pcpu_refcnt);
74 static void caifd_hold(struct caif_device_entry *e)
76 irqsafe_cpu_inc(*e->pcpu_refcnt);
79 static int caifd_refcnt_read(struct caif_device_entry *e)
81 int i, refcnt = 0;
82 for_each_possible_cpu(i)
83 refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
84 return refcnt;
87 /* Allocate new CAIF device. */
88 static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
90 struct caif_device_entry_list *caifdevs;
91 struct caif_device_entry *caifd;
93 caifdevs = caif_device_list(dev_net(dev));
94 BUG_ON(!caifdevs);
96 caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
97 if (!caifd)
98 return NULL;
99 caifd->pcpu_refcnt = alloc_percpu(int);
100 if (!caifd->pcpu_refcnt) {
101 kfree(caifd);
102 return NULL;
104 caifd->netdev = dev;
105 dev_hold(dev);
106 return caifd;
109 static struct caif_device_entry *caif_get(struct net_device *dev)
111 struct caif_device_entry_list *caifdevs =
112 caif_device_list(dev_net(dev));
113 struct caif_device_entry *caifd;
114 BUG_ON(!caifdevs);
115 list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
116 if (caifd->netdev == dev)
117 return caifd;
119 return NULL;
122 static int transmit(struct cflayer *layer, struct cfpkt *pkt)
124 int err;
125 struct caif_device_entry *caifd =
126 container_of(layer, struct caif_device_entry, layer);
127 struct sk_buff *skb;
129 skb = cfpkt_tonative(pkt);
130 skb->dev = caifd->netdev;
132 err = dev_queue_xmit(skb);
133 if (err > 0)
134 err = -EIO;
136 return err;
140 * Stuff received packets into the CAIF stack.
141 * On error, returns non-zero and releases the skb.
143 static int receive(struct sk_buff *skb, struct net_device *dev,
144 struct packet_type *pkttype, struct net_device *orig_dev)
146 struct cfpkt *pkt;
147 struct caif_device_entry *caifd;
148 int err;
150 pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
152 rcu_read_lock();
153 caifd = caif_get(dev);
155 if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
156 !netif_oper_up(caifd->netdev)) {
157 rcu_read_unlock();
158 kfree_skb(skb);
159 return NET_RX_DROP;
162 /* Hold reference to netdevice while using CAIF stack */
163 caifd_hold(caifd);
164 rcu_read_unlock();
166 err = caifd->layer.up->receive(caifd->layer.up, pkt);
168 /* For -EILSEQ the packet is not freed so so it now */
169 if (err == -EILSEQ)
170 cfpkt_destroy(pkt);
172 /* Release reference to stack upwards */
173 caifd_put(caifd);
174 return 0;
177 static struct packet_type caif_packet_type __read_mostly = {
178 .type = cpu_to_be16(ETH_P_CAIF),
179 .func = receive,
182 static void dev_flowctrl(struct net_device *dev, int on)
184 struct caif_device_entry *caifd;
186 rcu_read_lock();
188 caifd = caif_get(dev);
189 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
190 rcu_read_unlock();
191 return;
194 caifd_hold(caifd);
195 rcu_read_unlock();
197 caifd->layer.up->ctrlcmd(caifd->layer.up,
198 on ?
199 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
200 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
201 caifd->layer.id);
202 caifd_put(caifd);
205 /* notify Caif of device events */
206 static int caif_device_notify(struct notifier_block *me, unsigned long what,
207 void *arg)
209 struct net_device *dev = arg;
210 struct caif_device_entry *caifd = NULL;
211 struct caif_dev_common *caifdev;
212 enum cfcnfg_phy_preference pref;
213 enum cfcnfg_phy_type phy_type;
214 struct cfcnfg *cfg;
215 struct caif_device_entry_list *caifdevs;
217 if (dev->type != ARPHRD_CAIF)
218 return 0;
220 cfg = get_cfcnfg(dev_net(dev));
221 if (cfg == NULL)
222 return 0;
224 caifdevs = caif_device_list(dev_net(dev));
226 switch (what) {
227 case NETDEV_REGISTER:
228 caifd = caif_device_alloc(dev);
229 if (!caifd)
230 return 0;
232 caifdev = netdev_priv(dev);
233 caifdev->flowctrl = dev_flowctrl;
235 caifd->layer.transmit = transmit;
237 if (caifdev->use_frag)
238 phy_type = CFPHYTYPE_FRAG;
239 else
240 phy_type = CFPHYTYPE_CAIF;
242 switch (caifdev->link_select) {
243 case CAIF_LINK_HIGH_BANDW:
244 pref = CFPHYPREF_HIGH_BW;
245 break;
246 case CAIF_LINK_LOW_LATENCY:
247 pref = CFPHYPREF_LOW_LAT;
248 break;
249 default:
250 pref = CFPHYPREF_HIGH_BW;
251 break;
253 strncpy(caifd->layer.name, dev->name,
254 sizeof(caifd->layer.name) - 1);
255 caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
257 mutex_lock(&caifdevs->lock);
258 list_add_rcu(&caifd->list, &caifdevs->list);
260 cfcnfg_add_phy_layer(cfg,
261 phy_type,
262 dev,
263 &caifd->layer,
264 pref,
265 caifdev->use_fcs,
266 caifdev->use_stx);
267 mutex_unlock(&caifdevs->lock);
268 break;
270 case NETDEV_UP:
271 rcu_read_lock();
273 caifd = caif_get(dev);
274 if (caifd == NULL) {
275 rcu_read_unlock();
276 break;
279 cfcnfg_set_phy_state(cfg, &caifd->layer, true);
280 rcu_read_unlock();
282 break;
284 case NETDEV_DOWN:
285 rcu_read_lock();
287 caifd = caif_get(dev);
288 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
289 rcu_read_unlock();
290 return -EINVAL;
293 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
294 caifd_hold(caifd);
295 rcu_read_unlock();
297 caifd->layer.up->ctrlcmd(caifd->layer.up,
298 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
299 caifd->layer.id);
300 caifd_put(caifd);
301 break;
303 case NETDEV_UNREGISTER:
304 mutex_lock(&caifdevs->lock);
306 caifd = caif_get(dev);
307 if (caifd == NULL) {
308 mutex_unlock(&caifdevs->lock);
309 break;
311 list_del_rcu(&caifd->list);
314 * NETDEV_UNREGISTER is called repeatedly until all reference
315 * counts for the net-device are released. If references to
316 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
317 * the next call to NETDEV_UNREGISTER.
319 * If any packets are in flight down the CAIF Stack,
320 * cfcnfg_del_phy_layer will return nonzero.
321 * If no packets are in flight, the CAIF Stack associated
322 * with the net-device un-registering is freed.
325 if (caifd_refcnt_read(caifd) != 0 ||
326 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
328 pr_info("Wait for device inuse\n");
329 /* Enrole device if CAIF Stack is still in use */
330 list_add_rcu(&caifd->list, &caifdevs->list);
331 mutex_unlock(&caifdevs->lock);
332 break;
335 synchronize_rcu();
336 dev_put(caifd->netdev);
337 free_percpu(caifd->pcpu_refcnt);
338 kfree(caifd);
340 mutex_unlock(&caifdevs->lock);
341 break;
343 return 0;
346 static struct notifier_block caif_device_notifier = {
347 .notifier_call = caif_device_notify,
348 .priority = 0,
351 /* Per-namespace Caif devices handling */
352 static int caif_init_net(struct net *net)
354 struct caif_net *caifn = net_generic(net, caif_net_id);
355 BUG_ON(!caifn);
356 INIT_LIST_HEAD(&caifn->caifdevs.list);
357 mutex_init(&caifn->caifdevs.lock);
359 caifn->cfg = cfcnfg_create();
360 if (!caifn->cfg) {
361 pr_warn("can't create cfcnfg\n");
362 return -ENOMEM;
365 return 0;
368 static void caif_exit_net(struct net *net)
370 struct caif_device_entry *caifd, *tmp;
371 struct caif_device_entry_list *caifdevs =
372 caif_device_list(net);
373 struct cfcnfg *cfg;
375 rtnl_lock();
376 mutex_lock(&caifdevs->lock);
378 cfg = get_cfcnfg(net);
379 if (cfg == NULL) {
380 mutex_unlock(&caifdevs->lock);
381 return;
384 list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
385 int i = 0;
386 list_del_rcu(&caifd->list);
387 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
389 while (i < 10 &&
390 (caifd_refcnt_read(caifd) != 0 ||
391 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
393 pr_info("Wait for device inuse\n");
394 msleep(250);
395 i++;
397 synchronize_rcu();
398 dev_put(caifd->netdev);
399 free_percpu(caifd->pcpu_refcnt);
400 kfree(caifd);
402 cfcnfg_remove(cfg);
404 mutex_unlock(&caifdevs->lock);
405 rtnl_unlock();
408 static struct pernet_operations caif_net_ops = {
409 .init = caif_init_net,
410 .exit = caif_exit_net,
411 .id = &caif_net_id,
412 .size = sizeof(struct caif_net),
415 /* Initialize Caif devices list */
416 static int __init caif_device_init(void)
418 int result;
420 result = register_pernet_device(&caif_net_ops);
422 if (result)
423 return result;
425 register_netdevice_notifier(&caif_device_notifier);
426 dev_add_pack(&caif_packet_type);
428 return result;
431 static void __exit caif_device_exit(void)
433 unregister_pernet_device(&caif_net_ops);
434 unregister_netdevice_notifier(&caif_device_notifier);
435 dev_remove_pack(&caif_packet_type);
438 module_init(caif_device_init);
439 module_exit(caif_device_exit);