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 <linux/module.h>
20 #include <net/netns/generic.h>
21 #include <net/net_namespace.h>
22 #include <net/pkt_sched.h>
23 #include <net/caif/caif_device.h>
24 #include <net/caif/caif_layer.h>
25 #include <net/caif/cfpkt.h>
26 #include <net/caif/cfcnfg.h>
28 MODULE_LICENSE("GPL");
30 /* Used for local tracking of the CAIF net devices */
31 struct caif_device_entry {
33 struct list_head list;
34 struct net_device *netdev;
35 int __percpu *pcpu_refcnt;
38 struct caif_device_entry_list {
39 struct list_head list;
40 /* Protects simulanous deletes in list */
46 struct caif_device_entry_list caifdevs;
49 static int caif_net_id;
51 struct cfcnfg *get_cfcnfg(struct net *net)
53 struct caif_net *caifn;
55 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);
65 return &caifn->caifdevs;
68 static void caifd_put(struct caif_device_entry *e)
70 irqsafe_cpu_dec(*e->pcpu_refcnt);
73 static void caifd_hold(struct caif_device_entry *e)
75 irqsafe_cpu_inc(*e->pcpu_refcnt);
78 static int caifd_refcnt_read(struct caif_device_entry *e)
81 for_each_possible_cpu(i)
82 refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
86 /* Allocate new CAIF device. */
87 static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
89 struct caif_device_entry_list *caifdevs;
90 struct caif_device_entry *caifd;
92 caifdevs = caif_device_list(dev_net(dev));
94 caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
97 caifd->pcpu_refcnt = alloc_percpu(int);
98 if (!caifd->pcpu_refcnt) {
107 static struct caif_device_entry *caif_get(struct net_device *dev)
109 struct caif_device_entry_list *caifdevs =
110 caif_device_list(dev_net(dev));
111 struct caif_device_entry *caifd;
113 list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
114 if (caifd->netdev == dev)
120 static int transmit(struct cflayer *layer, struct cfpkt *pkt)
123 struct caif_device_entry *caifd =
124 container_of(layer, struct caif_device_entry, layer);
127 skb = cfpkt_tonative(pkt);
128 skb->dev = caifd->netdev;
130 err = dev_queue_xmit(skb);
138 * Stuff received packets into the CAIF stack.
139 * On error, returns non-zero and releases the skb.
141 static int receive(struct sk_buff *skb, struct net_device *dev,
142 struct packet_type *pkttype, struct net_device *orig_dev)
145 struct caif_device_entry *caifd;
148 pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
151 caifd = caif_get(dev);
153 if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
154 !netif_oper_up(caifd->netdev)) {
160 /* Hold reference to netdevice while using CAIF stack */
164 err = caifd->layer.up->receive(caifd->layer.up, pkt);
166 /* For -EILSEQ the packet is not freed so so it now */
170 /* Release reference to stack upwards */
175 static struct packet_type caif_packet_type __read_mostly = {
176 .type = cpu_to_be16(ETH_P_CAIF),
180 static void dev_flowctrl(struct net_device *dev, int on)
182 struct caif_device_entry *caifd;
186 caifd = caif_get(dev);
187 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
195 caifd->layer.up->ctrlcmd(caifd->layer.up,
197 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
198 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
203 /* notify Caif of device events */
204 static int caif_device_notify(struct notifier_block *me, unsigned long what,
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 enum cfcnfg_phy_type phy_type;
213 struct caif_device_entry_list *caifdevs;
215 if (dev->type != ARPHRD_CAIF)
218 cfg = get_cfcnfg(dev_net(dev));
222 caifdevs = caif_device_list(dev_net(dev));
225 case NETDEV_REGISTER:
226 caifd = caif_device_alloc(dev);
230 caifdev = netdev_priv(dev);
231 caifdev->flowctrl = dev_flowctrl;
233 caifd->layer.transmit = transmit;
235 if (caifdev->use_frag)
236 phy_type = CFPHYTYPE_FRAG;
238 phy_type = CFPHYTYPE_CAIF;
240 switch (caifdev->link_select) {
241 case CAIF_LINK_HIGH_BANDW:
242 pref = CFPHYPREF_HIGH_BW;
244 case CAIF_LINK_LOW_LATENCY:
245 pref = CFPHYPREF_LOW_LAT;
248 pref = CFPHYPREF_HIGH_BW;
251 strncpy(caifd->layer.name, dev->name,
252 sizeof(caifd->layer.name) - 1);
253 caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
255 mutex_lock(&caifdevs->lock);
256 list_add_rcu(&caifd->list, &caifdevs->list);
258 cfcnfg_add_phy_layer(cfg,
265 mutex_unlock(&caifdevs->lock);
271 caifd = caif_get(dev);
277 cfcnfg_set_phy_state(cfg, &caifd->layer, true);
285 caifd = caif_get(dev);
286 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
291 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
295 caifd->layer.up->ctrlcmd(caifd->layer.up,
296 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
301 case NETDEV_UNREGISTER:
302 mutex_lock(&caifdevs->lock);
304 caifd = caif_get(dev);
306 mutex_unlock(&caifdevs->lock);
309 list_del_rcu(&caifd->list);
312 * NETDEV_UNREGISTER is called repeatedly until all reference
313 * counts for the net-device are released. If references to
314 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
315 * the next call to NETDEV_UNREGISTER.
317 * If any packets are in flight down the CAIF Stack,
318 * cfcnfg_del_phy_layer will return nonzero.
319 * If no packets are in flight, the CAIF Stack associated
320 * with the net-device un-registering is freed.
323 if (caifd_refcnt_read(caifd) != 0 ||
324 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
326 pr_info("Wait for device inuse\n");
327 /* Enrole device if CAIF Stack is still in use */
328 list_add_rcu(&caifd->list, &caifdevs->list);
329 mutex_unlock(&caifdevs->lock);
334 dev_put(caifd->netdev);
335 free_percpu(caifd->pcpu_refcnt);
338 mutex_unlock(&caifdevs->lock);
344 static struct notifier_block caif_device_notifier = {
345 .notifier_call = caif_device_notify,
349 /* Per-namespace Caif devices handling */
350 static int caif_init_net(struct net *net)
352 struct caif_net *caifn = net_generic(net, caif_net_id);
354 INIT_LIST_HEAD(&caifn->caifdevs.list);
355 mutex_init(&caifn->caifdevs.lock);
357 caifn->cfg = cfcnfg_create();
359 pr_warn("can't create cfcnfg\n");
366 static void caif_exit_net(struct net *net)
368 struct caif_device_entry *caifd, *tmp;
369 struct caif_device_entry_list *caifdevs =
370 caif_device_list(net);
374 mutex_lock(&caifdevs->lock);
376 cfg = get_cfcnfg(net);
378 mutex_unlock(&caifdevs->lock);
382 list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
384 list_del_rcu(&caifd->list);
385 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
388 (caifd_refcnt_read(caifd) != 0 ||
389 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
391 pr_info("Wait for device inuse\n");
396 dev_put(caifd->netdev);
397 free_percpu(caifd->pcpu_refcnt);
402 mutex_unlock(&caifdevs->lock);
406 static struct pernet_operations caif_net_ops = {
407 .init = caif_init_net,
408 .exit = caif_exit_net,
410 .size = sizeof(struct caif_net),
413 /* Initialize Caif devices list */
414 static int __init caif_device_init(void)
418 result = register_pernet_subsys(&caif_net_ops);
423 register_netdevice_notifier(&caif_device_notifier);
424 dev_add_pack(&caif_packet_type);
429 static void __exit caif_device_exit(void)
431 unregister_netdevice_notifier(&caif_device_notifier);
432 dev_remove_pack(&caif_packet_type);
433 unregister_pernet_subsys(&caif_net_ops);
436 module_init(caif_device_init);
437 module_exit(caif_device_exit);