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 {
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 */
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;
54 caifn = net_generic(net, caif_net_id);
58 EXPORT_SYMBOL(get_cfcnfg);
60 static struct caif_device_entry_list *caif_device_list(struct net *net)
62 struct caif_net *caifn;
64 caifn = net_generic(net, caif_net_id);
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)
82 for_each_possible_cpu(i)
83 refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
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));
96 caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
99 caifd->pcpu_refcnt = alloc_percpu(int);
100 if (!caifd->pcpu_refcnt) {
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;
115 list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
116 if (caifd->netdev == dev)
122 static int transmit(struct cflayer *layer, struct cfpkt *pkt)
125 struct caif_device_entry *caifd =
126 container_of(layer, struct caif_device_entry, layer);
129 skb = cfpkt_tonative(pkt);
130 skb->dev = caifd->netdev;
132 err = dev_queue_xmit(skb);
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)
147 struct caif_device_entry *caifd;
150 pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
153 caifd = caif_get(dev);
155 if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
156 !netif_oper_up(caifd->netdev)) {
162 /* Hold reference to netdevice while using CAIF stack */
166 err = caifd->layer.up->receive(caifd->layer.up, pkt);
168 /* For -EILSEQ the packet is not freed so so it now */
172 /* Release reference to stack upwards */
177 static struct packet_type caif_packet_type __read_mostly = {
178 .type = cpu_to_be16(ETH_P_CAIF),
182 static void dev_flowctrl(struct net_device *dev, int on)
184 struct caif_device_entry *caifd;
188 caifd = caif_get(dev);
189 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
197 caifd->layer.up->ctrlcmd(caifd->layer.up,
199 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
200 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
205 /* notify Caif of device events */
206 static int caif_device_notify(struct notifier_block *me, unsigned long what,
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;
215 struct caif_device_entry_list *caifdevs =
216 caif_device_list(dev_net(dev));
218 if (dev->type != ARPHRD_CAIF)
221 cfg = get_cfcnfg(dev_net(dev));
226 case NETDEV_REGISTER:
227 caifd = caif_device_alloc(dev);
231 caifdev = netdev_priv(dev);
232 caifdev->flowctrl = dev_flowctrl;
234 caifd->layer.transmit = transmit;
236 if (caifdev->use_frag)
237 phy_type = CFPHYTYPE_FRAG;
239 phy_type = CFPHYTYPE_CAIF;
241 switch (caifdev->link_select) {
242 case CAIF_LINK_HIGH_BANDW:
243 pref = CFPHYPREF_HIGH_BW;
245 case CAIF_LINK_LOW_LATENCY:
246 pref = CFPHYPREF_LOW_LAT;
249 pref = CFPHYPREF_HIGH_BW;
252 strncpy(caifd->layer.name, dev->name,
253 sizeof(caifd->layer.name) - 1);
254 caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
256 mutex_lock(&caifdevs->lock);
257 list_add_rcu(&caifd->list, &caifdevs->list);
259 cfcnfg_add_phy_layer(cfg,
266 mutex_unlock(&caifdevs->lock);
272 caifd = caif_get(dev);
278 cfcnfg_set_phy_state(cfg, &caifd->layer, true);
286 caifd = caif_get(dev);
287 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
292 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
296 caifd->layer.up->ctrlcmd(caifd->layer.up,
297 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
302 case NETDEV_UNREGISTER:
303 mutex_lock(&caifdevs->lock);
305 caifd = caif_get(dev);
307 mutex_unlock(&caifdevs->lock);
310 list_del_rcu(&caifd->list);
313 * NETDEV_UNREGISTER is called repeatedly until all reference
314 * counts for the net-device are released. If references to
315 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
316 * the next call to NETDEV_UNREGISTER.
318 * If any packets are in flight down the CAIF Stack,
319 * cfcnfg_del_phy_layer will return nonzero.
320 * If no packets are in flight, the CAIF Stack associated
321 * with the net-device un-registering is freed.
324 if (caifd_refcnt_read(caifd) != 0 ||
325 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
327 pr_info("Wait for device inuse\n");
328 /* Enrole device if CAIF Stack is still in use */
329 list_add_rcu(&caifd->list, &caifdevs->list);
330 mutex_unlock(&caifdevs->lock);
335 dev_put(caifd->netdev);
336 free_percpu(caifd->pcpu_refcnt);
339 mutex_unlock(&caifdevs->lock);
345 static struct notifier_block caif_device_notifier = {
346 .notifier_call = caif_device_notify,
350 /* Per-namespace Caif devices handling */
351 static int caif_init_net(struct net *net)
353 struct caif_net *caifn = net_generic(net, caif_net_id);
355 INIT_LIST_HEAD(&caifn->caifdevs.list);
356 mutex_init(&caifn->caifdevs.lock);
358 caifn->cfg = cfcnfg_create();
360 pr_warn("can't create cfcnfg\n");
367 static void caif_exit_net(struct net *net)
369 struct caif_device_entry *caifd, *tmp;
370 struct caif_device_entry_list *caifdevs =
371 caif_device_list(net);
375 mutex_lock(&caifdevs->lock);
377 cfg = get_cfcnfg(net);
379 mutex_unlock(&caifdevs->lock);
383 list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
385 list_del_rcu(&caifd->list);
386 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
389 (caifd_refcnt_read(caifd) != 0 ||
390 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
392 pr_info("Wait for device inuse\n");
397 dev_put(caifd->netdev);
398 free_percpu(caifd->pcpu_refcnt);
403 mutex_unlock(&caifdevs->lock);
407 static struct pernet_operations caif_net_ops = {
408 .init = caif_init_net,
409 .exit = caif_exit_net,
411 .size = sizeof(struct caif_net),
414 /* Initialize Caif devices list */
415 static int __init caif_device_init(void)
419 result = register_pernet_device(&caif_net_ops);
424 register_netdevice_notifier(&caif_device_notifier);
425 dev_add_pack(&caif_packet_type);
430 static void __exit caif_device_exit(void)
432 unregister_pernet_device(&caif_net_ops);
433 unregister_netdevice_notifier(&caif_device_notifier);
434 dev_remove_pack(&caif_packet_type);
437 module_init(caif_device_init);
438 module_exit(caif_device_exit);