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Sjur Braendelandc72dfae2010-03-30 13:56:25 +00001/*
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 *
Rémi Denis-Courmont31fdc552012-06-13 22:29:03 +00007 * Borrowed heavily from file: pn_dev.c. Thanks to Remi Denis-Courmont
Sjur Braendelandc72dfae2010-03-30 13:56:25 +00008 * and Sakari Ailus <sakari.ailus@nokia.com>
9 */
10
Joe Perchesb31fa5b2010-09-05 21:31:11 +000011#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
12
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000013#include <linux/kernel.h>
14#include <linux/if_arp.h>
15#include <linux/net.h>
16#include <linux/netdevice.h>
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000017#include <linux/mutex.h>
Paul Gortmaker3a9a2312011-05-27 09:12:25 -040018#include <linux/module.h>
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +000019#include <linux/spinlock.h>
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000020#include <net/netns/generic.h>
21#include <net/net_namespace.h>
22#include <net/pkt_sched.h>
23#include <net/caif/caif_device.h>
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000024#include <net/caif/caif_layer.h>
25#include <net/caif/cfpkt.h>
26#include <net/caif/cfcnfg.h>
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +000027#include <net/caif/cfserl.h>
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000028
29MODULE_LICENSE("GPL");
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000030
31/* Used for local tracking of the CAIF net devices */
32struct caif_device_entry {
33 struct cflayer layer;
34 struct list_head list;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000035 struct net_device *netdev;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000036 int __percpu *pcpu_refcnt;
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +000037 spinlock_t flow_lock;
sjur.brandeland@stericsson.com7d311302011-12-04 11:22:55 +000038 struct sk_buff *xoff_skb;
39 void (*xoff_skb_dtor)(struct sk_buff *skb);
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +000040 bool xoff;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000041};
42
43struct caif_device_entry_list {
44 struct list_head list;
45 /* Protects simulanous deletes in list */
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000046 struct mutex lock;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000047};
48
49struct caif_net {
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +000050 struct cfcnfg *cfg;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000051 struct caif_device_entry_list caifdevs;
52};
53
54static int caif_net_id;
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +000055static int q_high = 50; /* Percent */
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +000056
57struct cfcnfg *get_cfcnfg(struct net *net)
58{
59 struct caif_net *caifn;
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +000060 caifn = net_generic(net, caif_net_id);
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +000061 return caifn->cfg;
62}
63EXPORT_SYMBOL(get_cfcnfg);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000064
65static struct caif_device_entry_list *caif_device_list(struct net *net)
66{
67 struct caif_net *caifn;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000068 caifn = net_generic(net, caif_net_id);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000069 return &caifn->caifdevs;
70}
71
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000072static void caifd_put(struct caif_device_entry *e)
73{
Christoph Lameter933393f2011-12-22 11:58:51 -060074 this_cpu_dec(*e->pcpu_refcnt);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000075}
76
77static void caifd_hold(struct caif_device_entry *e)
78{
Christoph Lameter933393f2011-12-22 11:58:51 -060079 this_cpu_inc(*e->pcpu_refcnt);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000080}
81
82static int caifd_refcnt_read(struct caif_device_entry *e)
83{
84 int i, refcnt = 0;
85 for_each_possible_cpu(i)
86 refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
87 return refcnt;
88}
89
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000090/* Allocate new CAIF device. */
91static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
92{
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000093 struct caif_device_entry *caifd;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000094
Eric Dumazet4fb66b82011-09-02 02:19:23 +000095 caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +000096 if (!caifd)
97 return NULL;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +000098 caifd->pcpu_refcnt = alloc_percpu(int);
Eric Dumazet4fb66b82011-09-02 02:19:23 +000099 if (!caifd->pcpu_refcnt) {
100 kfree(caifd);
101 return NULL;
102 }
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000103 caifd->netdev = dev;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000104 dev_hold(dev);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000105 return caifd;
106}
107
108static struct caif_device_entry *caif_get(struct net_device *dev)
109{
110 struct caif_device_entry_list *caifdevs =
111 caif_device_list(dev_net(dev));
112 struct caif_device_entry *caifd;
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000113
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000114 list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000115 if (caifd->netdev == dev)
116 return caifd;
117 }
118 return NULL;
119}
120
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000121void caif_flow_cb(struct sk_buff *skb)
122{
123 struct caif_device_entry *caifd;
sjur.brandeland@stericsson.com7d311302011-12-04 11:22:55 +0000124 void (*dtor)(struct sk_buff *skb) = NULL;
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000125 bool send_xoff;
126
127 WARN_ON(skb->dev == NULL);
128
129 rcu_read_lock();
130 caifd = caif_get(skb->dev);
Kim Lilliestierna XXc95567c2012-06-25 07:49:34 +0000131
132 WARN_ON(caifd == NULL);
133 if (caifd == NULL)
134 return;
135
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000136 caifd_hold(caifd);
137 rcu_read_unlock();
138
139 spin_lock_bh(&caifd->flow_lock);
140 send_xoff = caifd->xoff;
141 caifd->xoff = 0;
sjur.brandeland@stericsson.com59f608d2012-01-17 03:03:14 +0000142 dtor = caifd->xoff_skb_dtor;
143
144 if (WARN_ON(caifd->xoff_skb != skb))
145 skb = NULL;
146
147 caifd->xoff_skb = NULL;
148 caifd->xoff_skb_dtor = NULL;
149
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000150 spin_unlock_bh(&caifd->flow_lock);
151
sjur.brandeland@stericsson.com59f608d2012-01-17 03:03:14 +0000152 if (dtor && skb)
sjur.brandeland@stericsson.com7d311302011-12-04 11:22:55 +0000153 dtor(skb);
154
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000155 if (send_xoff)
156 caifd->layer.up->
157 ctrlcmd(caifd->layer.up,
158 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND,
159 caifd->layer.id);
160 caifd_put(caifd);
161}
162
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000163static int transmit(struct cflayer *layer, struct cfpkt *pkt)
164{
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000165 int err, high = 0, qlen = 0;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000166 struct caif_device_entry *caifd =
167 container_of(layer, struct caif_device_entry, layer);
Sjur Brændeland4dd820c2011-04-11 10:43:51 +0000168 struct sk_buff *skb;
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000169 struct netdev_queue *txq;
170
171 rcu_read_lock_bh();
Sjur Brændeland4dd820c2011-04-11 10:43:51 +0000172
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000173 skb = cfpkt_tonative(pkt);
174 skb->dev = caifd->netdev;
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000175 skb_reset_network_header(skb);
176 skb->protocol = htons(ETH_P_CAIF);
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000177
178 /* Check if we need to handle xoff */
179 if (likely(caifd->netdev->tx_queue_len == 0))
180 goto noxoff;
181
182 if (unlikely(caifd->xoff))
183 goto noxoff;
184
185 if (likely(!netif_queue_stopped(caifd->netdev))) {
186 /* If we run with a TX queue, check if the queue is too long*/
187 txq = netdev_get_tx_queue(skb->dev, 0);
188 qlen = qdisc_qlen(rcu_dereference_bh(txq->qdisc));
189
190 if (likely(qlen == 0))
191 goto noxoff;
192
193 high = (caifd->netdev->tx_queue_len * q_high) / 100;
194 if (likely(qlen < high))
195 goto noxoff;
196 }
197
198 /* Hold lock while accessing xoff */
199 spin_lock_bh(&caifd->flow_lock);
200 if (caifd->xoff) {
201 spin_unlock_bh(&caifd->flow_lock);
202 goto noxoff;
203 }
204
205 /*
206 * Handle flow off, we do this by temporary hi-jacking this
207 * skb's destructor function, and replace it with our own
208 * flow-on callback. The callback will set flow-on and call
209 * the original destructor.
210 */
211
212 pr_debug("queue has stopped(%d) or is full (%d > %d)\n",
213 netif_queue_stopped(caifd->netdev),
214 qlen, high);
215 caifd->xoff = 1;
sjur.brandeland@stericsson.com7d311302011-12-04 11:22:55 +0000216 caifd->xoff_skb = skb;
217 caifd->xoff_skb_dtor = skb->destructor;
218 skb->destructor = caif_flow_cb;
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000219 spin_unlock_bh(&caifd->flow_lock);
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000220
221 caifd->layer.up->ctrlcmd(caifd->layer.up,
222 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
223 caifd->layer.id);
224noxoff:
225 rcu_read_unlock_bh();
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000226
sjur.brandeland@stericsson.comc85c2952011-05-13 02:44:06 +0000227 err = dev_queue_xmit(skb);
228 if (err > 0)
229 err = -EIO;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000230
sjur.brandeland@stericsson.comc85c2952011-05-13 02:44:06 +0000231 return err;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000232}
233
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000234/*
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000235 * Stuff received packets into the CAIF stack.
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000236 * On error, returns non-zero and releases the skb.
237 */
238static int receive(struct sk_buff *skb, struct net_device *dev,
239 struct packet_type *pkttype, struct net_device *orig_dev)
240{
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000241 struct cfpkt *pkt;
242 struct caif_device_entry *caifd;
sjur.brandeland@stericsson.com69c867c92011-05-22 11:18:54 +0000243 int err;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000244
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000245 pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000246
247 rcu_read_lock();
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000248 caifd = caif_get(dev);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000249
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000250 if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
251 !netif_oper_up(caifd->netdev)) {
252 rcu_read_unlock();
253 kfree_skb(skb);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000254 return NET_RX_DROP;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000255 }
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000256
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000257 /* Hold reference to netdevice while using CAIF stack */
258 caifd_hold(caifd);
259 rcu_read_unlock();
260
sjur.brandeland@stericsson.com69c867c92011-05-22 11:18:54 +0000261 err = caifd->layer.up->receive(caifd->layer.up, pkt);
262
263 /* For -EILSEQ the packet is not freed so so it now */
264 if (err == -EILSEQ)
265 cfpkt_destroy(pkt);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000266
267 /* Release reference to stack upwards */
268 caifd_put(caifd);
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000269
270 if (err != 0)
271 err = NET_RX_DROP;
272 return err;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000273}
274
275static struct packet_type caif_packet_type __read_mostly = {
276 .type = cpu_to_be16(ETH_P_CAIF),
277 .func = receive,
278};
279
280static void dev_flowctrl(struct net_device *dev, int on)
281{
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000282 struct caif_device_entry *caifd;
283
284 rcu_read_lock();
285
286 caifd = caif_get(dev);
287 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
288 rcu_read_unlock();
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000289 return;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000290 }
291
292 caifd_hold(caifd);
293 rcu_read_unlock();
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000294
295 caifd->layer.up->ctrlcmd(caifd->layer.up,
296 on ?
297 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
298 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
299 caifd->layer.id);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000300 caifd_put(caifd);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000301}
302
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000303void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
304 struct cflayer *link_support, int head_room,
305 struct cflayer **layer, int (**rcv_func)(
306 struct sk_buff *, struct net_device *,
307 struct packet_type *, struct net_device *))
308{
309 struct caif_device_entry *caifd;
310 enum cfcnfg_phy_preference pref;
311 struct cfcnfg *cfg = get_cfcnfg(dev_net(dev));
312 struct caif_device_entry_list *caifdevs;
313
314 caifdevs = caif_device_list(dev_net(dev));
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000315 caifd = caif_device_alloc(dev);
316 if (!caifd)
317 return;
318 *layer = &caifd->layer;
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000319 spin_lock_init(&caifd->flow_lock);
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000320
321 switch (caifdev->link_select) {
322 case CAIF_LINK_HIGH_BANDW:
323 pref = CFPHYPREF_HIGH_BW;
324 break;
325 case CAIF_LINK_LOW_LATENCY:
326 pref = CFPHYPREF_LOW_LAT;
327 break;
328 default:
329 pref = CFPHYPREF_HIGH_BW;
330 break;
331 }
332 mutex_lock(&caifdevs->lock);
333 list_add_rcu(&caifd->list, &caifdevs->list);
334
335 strncpy(caifd->layer.name, dev->name,
336 sizeof(caifd->layer.name) - 1);
337 caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
338 caifd->layer.transmit = transmit;
339 cfcnfg_add_phy_layer(cfg,
340 dev,
341 &caifd->layer,
342 pref,
343 link_support,
344 caifdev->use_fcs,
345 head_room);
346 mutex_unlock(&caifdevs->lock);
347 if (rcv_func)
348 *rcv_func = receive;
349}
sjur.brandeland@stericsson.com7ad65bf2011-12-04 11:22:53 +0000350EXPORT_SYMBOL(caif_enroll_dev);
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000351
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000352/* notify Caif of device events */
353static int caif_device_notify(struct notifier_block *me, unsigned long what,
354 void *arg)
355{
356 struct net_device *dev = arg;
357 struct caif_device_entry *caifd = NULL;
358 struct caif_dev_common *caifdev;
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000359 struct cfcnfg *cfg;
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000360 struct cflayer *layer, *link_support;
361 int head_room = 0;
David Woodhouse08613e42011-10-24 21:25:21 +0000362 struct caif_device_entry_list *caifdevs;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000363
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000364 cfg = get_cfcnfg(dev_net(dev));
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000365 caifdevs = caif_device_list(dev_net(dev));
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000366
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000367 caifd = caif_get(dev);
368 if (caifd == NULL && dev->type != ARPHRD_CAIF)
369 return 0;
David Woodhouse08613e42011-10-24 21:25:21 +0000370
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000371 switch (what) {
372 case NETDEV_REGISTER:
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000373 if (caifd != NULL)
374 break;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000375
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000376 caifdev = netdev_priv(dev);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000377
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000378 link_support = NULL;
379 if (caifdev->use_frag) {
380 head_room = 1;
381 link_support = cfserl_create(dev->ifindex,
sjur.brandeland@stericsson.come977b4c2011-11-30 09:22:48 +0000382 caifdev->use_stx);
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000383 if (!link_support) {
384 pr_warn("Out of memory\n");
385 break;
386 }
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000387 }
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000388 caif_enroll_dev(dev, caifdev, link_support, head_room,
389 &layer, NULL);
390 caifdev->flowctrl = dev_flowctrl;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000391 break;
392
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000393 case NETDEV_UP:
394 rcu_read_lock();
395
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000396 caifd = caif_get(dev);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000397 if (caifd == NULL) {
398 rcu_read_unlock();
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000399 break;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000400 }
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000401
sjur.brandeland@stericsson.com0e4c7d82011-12-04 11:22:54 +0000402 caifd->xoff = 0;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000403 cfcnfg_set_phy_state(cfg, &caifd->layer, true);
404 rcu_read_unlock();
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000405
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000406 break;
407
408 case NETDEV_DOWN:
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000409 rcu_read_lock();
410
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000411 caifd = caif_get(dev);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000412 if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
413 rcu_read_unlock();
414 return -EINVAL;
415 }
416
417 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
418 caifd_hold(caifd);
419 rcu_read_unlock();
420
421 caifd->layer.up->ctrlcmd(caifd->layer.up,
422 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
423 caifd->layer.id);
sjur.brandeland@stericsson.com7d311302011-12-04 11:22:55 +0000424
425 spin_lock_bh(&caifd->flow_lock);
426
427 /*
428 * Replace our xoff-destructor with original destructor.
429 * We trust that skb->destructor *always* is called before
430 * the skb reference is invalid. The hijacked SKB destructor
431 * takes the flow_lock so manipulating the skb->destructor here
432 * should be safe.
433 */
434 if (caifd->xoff_skb_dtor != NULL && caifd->xoff_skb != NULL)
435 caifd->xoff_skb->destructor = caifd->xoff_skb_dtor;
436
437 caifd->xoff = 0;
438 caifd->xoff_skb_dtor = NULL;
439 caifd->xoff_skb = NULL;
440
441 spin_unlock_bh(&caifd->flow_lock);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000442 caifd_put(caifd);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000443 break;
444
445 case NETDEV_UNREGISTER:
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000446 mutex_lock(&caifdevs->lock);
447
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000448 caifd = caif_get(dev);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000449 if (caifd == NULL) {
450 mutex_unlock(&caifdevs->lock);
André Carvalho de Matosf2527ec2010-11-01 11:52:47 +0000451 break;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000452 }
453 list_del_rcu(&caifd->list);
454
455 /*
456 * NETDEV_UNREGISTER is called repeatedly until all reference
457 * counts for the net-device are released. If references to
458 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
459 * the next call to NETDEV_UNREGISTER.
460 *
461 * If any packets are in flight down the CAIF Stack,
462 * cfcnfg_del_phy_layer will return nonzero.
463 * If no packets are in flight, the CAIF Stack associated
464 * with the net-device un-registering is freed.
465 */
466
467 if (caifd_refcnt_read(caifd) != 0 ||
468 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
469
470 pr_info("Wait for device inuse\n");
471 /* Enrole device if CAIF Stack is still in use */
472 list_add_rcu(&caifd->list, &caifdevs->list);
473 mutex_unlock(&caifdevs->lock);
474 break;
475 }
476
477 synchronize_rcu();
478 dev_put(caifd->netdev);
479 free_percpu(caifd->pcpu_refcnt);
480 kfree(caifd);
481
482 mutex_unlock(&caifdevs->lock);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000483 break;
484 }
485 return 0;
486}
487
488static struct notifier_block caif_device_notifier = {
489 .notifier_call = caif_device_notify,
490 .priority = 0,
491};
492
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000493/* Per-namespace Caif devices handling */
494static int caif_init_net(struct net *net)
495{
496 struct caif_net *caifn = net_generic(net, caif_net_id);
497 INIT_LIST_HEAD(&caifn->caifdevs.list);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000498 mutex_init(&caifn->caifdevs.lock);
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000499
500 caifn->cfg = cfcnfg_create();
Roar Førdef84ea772011-12-06 12:15:44 +0000501 if (!caifn->cfg)
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000502 return -ENOMEM;
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000503
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000504 return 0;
505}
506
507static void caif_exit_net(struct net *net)
508{
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000509 struct caif_device_entry *caifd, *tmp;
510 struct caif_device_entry_list *caifdevs =
511 caif_device_list(net);
sjur.brandeland@stericsson.com7c18d222011-11-30 09:22:47 +0000512 struct cfcnfg *cfg = get_cfcnfg(net);
513
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000514 rtnl_lock();
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000515 mutex_lock(&caifdevs->lock);
516
517 list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
518 int i = 0;
519 list_del_rcu(&caifd->list);
520 cfcnfg_set_phy_state(cfg, &caifd->layer, false);
521
522 while (i < 10 &&
523 (caifd_refcnt_read(caifd) != 0 ||
524 cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
525
526 pr_info("Wait for device inuse\n");
527 msleep(250);
528 i++;
529 }
530 synchronize_rcu();
531 dev_put(caifd->netdev);
532 free_percpu(caifd->pcpu_refcnt);
533 kfree(caifd);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000534 }
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000535 cfcnfg_remove(cfg);
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000536
537 mutex_unlock(&caifdevs->lock);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000538 rtnl_unlock();
539}
540
541static struct pernet_operations caif_net_ops = {
542 .init = caif_init_net,
543 .exit = caif_exit_net,
544 .id = &caif_net_id,
545 .size = sizeof(struct caif_net),
546};
547
548/* Initialize Caif devices list */
549static int __init caif_device_init(void)
550{
551 int result;
sjur.brandeland@stericsson.combd30ce42011-05-13 02:44:00 +0000552
Eric W. Biederman8a8ee9a2012-01-26 14:04:53 +0000553 result = register_pernet_subsys(&caif_net_ops);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000554
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000555 if (result)
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000556 return result;
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000557
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000558 register_netdevice_notifier(&caif_device_notifier);
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000559 dev_add_pack(&caif_packet_type);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000560
561 return result;
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000562}
563
564static void __exit caif_device_exit(void)
565{
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000566 unregister_netdevice_notifier(&caif_device_notifier);
sjur.brandeland@stericsson.combee925d2011-05-13 02:44:05 +0000567 dev_remove_pack(&caif_packet_type);
Sjur Brændeland96f80d12012-07-15 10:10:14 +0000568 unregister_pernet_subsys(&caif_net_ops);
Sjur Braendelandc72dfae2010-03-30 13:56:25 +0000569}
570
571module_init(caif_device_init);
572module_exit(caif_device_exit);