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 <linux/spinlock.h>
21 #include <net/netns/generic.h>
22 #include <net/net_namespace.h>
23 #include <net/pkt_sched.h>
24 #include <net/caif/caif_device.h>
25 #include <net/caif/caif_layer.h>
26 #include <net/caif/cfpkt.h>
27 #include <net/caif/cfcnfg.h>
28 #include <net/caif/cfserl.h>
30 MODULE_LICENSE("GPL");
32 /* Used for local tracking of the CAIF net devices */
33 struct caif_device_entry
{
35 struct list_head list
;
36 struct net_device
*netdev
;
37 int __percpu
*pcpu_refcnt
;
39 struct sk_buff
*xoff_skb
;
40 void (*xoff_skb_dtor
)(struct sk_buff
*skb
);
44 struct caif_device_entry_list
{
45 struct list_head list
;
46 /* Protects simulanous deletes in list */
52 struct caif_device_entry_list caifdevs
;
55 static int caif_net_id
;
56 static int q_high
= 50; /* Percent */
58 struct cfcnfg
*get_cfcnfg(struct net
*net
)
60 struct caif_net
*caifn
;
61 caifn
= net_generic(net
, caif_net_id
);
66 EXPORT_SYMBOL(get_cfcnfg
);
68 static struct caif_device_entry_list
*caif_device_list(struct net
*net
)
70 struct caif_net
*caifn
;
71 caifn
= net_generic(net
, caif_net_id
);
74 return &caifn
->caifdevs
;
77 static void caifd_put(struct caif_device_entry
*e
)
79 this_cpu_dec(*e
->pcpu_refcnt
);
82 static void caifd_hold(struct caif_device_entry
*e
)
84 this_cpu_inc(*e
->pcpu_refcnt
);
87 static int caifd_refcnt_read(struct caif_device_entry
*e
)
90 for_each_possible_cpu(i
)
91 refcnt
+= *per_cpu_ptr(e
->pcpu_refcnt
, i
);
95 /* Allocate new CAIF device. */
96 static struct caif_device_entry
*caif_device_alloc(struct net_device
*dev
)
98 struct caif_device_entry_list
*caifdevs
;
99 struct caif_device_entry
*caifd
;
101 caifdevs
= caif_device_list(dev_net(dev
));
105 caifd
= kzalloc(sizeof(*caifd
), GFP_KERNEL
);
108 caifd
->pcpu_refcnt
= alloc_percpu(int);
109 if (!caifd
->pcpu_refcnt
) {
118 static struct caif_device_entry
*caif_get(struct net_device
*dev
)
120 struct caif_device_entry_list
*caifdevs
=
121 caif_device_list(dev_net(dev
));
122 struct caif_device_entry
*caifd
;
126 list_for_each_entry_rcu(caifd
, &caifdevs
->list
, list
) {
127 if (caifd
->netdev
== dev
)
133 void caif_flow_cb(struct sk_buff
*skb
)
135 struct caif_device_entry
*caifd
;
136 void (*dtor
)(struct sk_buff
*skb
) = NULL
;
139 WARN_ON(skb
->dev
== NULL
);
142 caifd
= caif_get(skb
->dev
);
146 spin_lock_bh(&caifd
->flow_lock
);
147 send_xoff
= caifd
->xoff
;
149 dtor
= caifd
->xoff_skb_dtor
;
151 if (WARN_ON(caifd
->xoff_skb
!= skb
))
154 caifd
->xoff_skb
= NULL
;
155 caifd
->xoff_skb_dtor
= NULL
;
157 spin_unlock_bh(&caifd
->flow_lock
);
164 ctrlcmd(caifd
->layer
.up
,
165 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND
,
170 static int transmit(struct cflayer
*layer
, struct cfpkt
*pkt
)
172 int err
, high
= 0, qlen
= 0;
173 struct caif_dev_common
*caifdev
;
174 struct caif_device_entry
*caifd
=
175 container_of(layer
, struct caif_device_entry
, layer
);
177 struct netdev_queue
*txq
;
181 skb
= cfpkt_tonative(pkt
);
182 skb
->dev
= caifd
->netdev
;
183 skb_reset_network_header(skb
);
184 skb
->protocol
= htons(ETH_P_CAIF
);
185 caifdev
= netdev_priv(caifd
->netdev
);
187 /* Check if we need to handle xoff */
188 if (likely(caifd
->netdev
->tx_queue_len
== 0))
191 if (unlikely(caifd
->xoff
))
194 if (likely(!netif_queue_stopped(caifd
->netdev
))) {
195 /* If we run with a TX queue, check if the queue is too long*/
196 txq
= netdev_get_tx_queue(skb
->dev
, 0);
197 qlen
= qdisc_qlen(rcu_dereference_bh(txq
->qdisc
));
199 if (likely(qlen
== 0))
202 high
= (caifd
->netdev
->tx_queue_len
* q_high
) / 100;
203 if (likely(qlen
< high
))
207 /* Hold lock while accessing xoff */
208 spin_lock_bh(&caifd
->flow_lock
);
210 spin_unlock_bh(&caifd
->flow_lock
);
215 * Handle flow off, we do this by temporary hi-jacking this
216 * skb's destructor function, and replace it with our own
217 * flow-on callback. The callback will set flow-on and call
218 * the original destructor.
221 pr_debug("queue has stopped(%d) or is full (%d > %d)\n",
222 netif_queue_stopped(caifd
->netdev
),
225 caifd
->xoff_skb
= skb
;
226 caifd
->xoff_skb_dtor
= skb
->destructor
;
227 skb
->destructor
= caif_flow_cb
;
228 spin_unlock_bh(&caifd
->flow_lock
);
230 caifd
->layer
.up
->ctrlcmd(caifd
->layer
.up
,
231 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND
,
234 rcu_read_unlock_bh();
236 err
= dev_queue_xmit(skb
);
244 * Stuff received packets into the CAIF stack.
245 * On error, returns non-zero and releases the skb.
247 static int receive(struct sk_buff
*skb
, struct net_device
*dev
,
248 struct packet_type
*pkttype
, struct net_device
*orig_dev
)
251 struct caif_device_entry
*caifd
;
254 pkt
= cfpkt_fromnative(CAIF_DIR_IN
, skb
);
257 caifd
= caif_get(dev
);
259 if (!caifd
|| !caifd
->layer
.up
|| !caifd
->layer
.up
->receive
||
260 !netif_oper_up(caifd
->netdev
)) {
266 /* Hold reference to netdevice while using CAIF stack */
270 err
= caifd
->layer
.up
->receive(caifd
->layer
.up
, pkt
);
272 /* For -EILSEQ the packet is not freed so so it now */
276 /* Release reference to stack upwards */
284 static struct packet_type caif_packet_type __read_mostly
= {
285 .type
= cpu_to_be16(ETH_P_CAIF
),
289 static void dev_flowctrl(struct net_device
*dev
, int on
)
291 struct caif_device_entry
*caifd
;
295 caifd
= caif_get(dev
);
296 if (!caifd
|| !caifd
->layer
.up
|| !caifd
->layer
.up
->ctrlcmd
) {
304 caifd
->layer
.up
->ctrlcmd(caifd
->layer
.up
,
306 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND
:
307 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND
,
312 void caif_enroll_dev(struct net_device
*dev
, struct caif_dev_common
*caifdev
,
313 struct cflayer
*link_support
, int head_room
,
314 struct cflayer
**layer
, int (**rcv_func
)(
315 struct sk_buff
*, struct net_device
*,
316 struct packet_type
*, struct net_device
*))
318 struct caif_device_entry
*caifd
;
319 enum cfcnfg_phy_preference pref
;
320 struct cfcnfg
*cfg
= get_cfcnfg(dev_net(dev
));
321 struct caif_device_entry_list
*caifdevs
;
323 caifdevs
= caif_device_list(dev_net(dev
));
324 if (!cfg
|| !caifdevs
)
326 caifd
= caif_device_alloc(dev
);
329 *layer
= &caifd
->layer
;
330 spin_lock_init(&caifd
->flow_lock
);
332 switch (caifdev
->link_select
) {
333 case CAIF_LINK_HIGH_BANDW
:
334 pref
= CFPHYPREF_HIGH_BW
;
336 case CAIF_LINK_LOW_LATENCY
:
337 pref
= CFPHYPREF_LOW_LAT
;
340 pref
= CFPHYPREF_HIGH_BW
;
343 mutex_lock(&caifdevs
->lock
);
344 list_add_rcu(&caifd
->list
, &caifdevs
->list
);
346 strncpy(caifd
->layer
.name
, dev
->name
,
347 sizeof(caifd
->layer
.name
) - 1);
348 caifd
->layer
.name
[sizeof(caifd
->layer
.name
) - 1] = 0;
349 caifd
->layer
.transmit
= transmit
;
350 cfcnfg_add_phy_layer(cfg
,
357 mutex_unlock(&caifdevs
->lock
);
361 EXPORT_SYMBOL(caif_enroll_dev
);
363 /* notify Caif of device events */
364 static int caif_device_notify(struct notifier_block
*me
, unsigned long what
,
367 struct net_device
*dev
= arg
;
368 struct caif_device_entry
*caifd
= NULL
;
369 struct caif_dev_common
*caifdev
;
371 struct cflayer
*layer
, *link_support
;
373 struct caif_device_entry_list
*caifdevs
;
375 cfg
= get_cfcnfg(dev_net(dev
));
376 caifdevs
= caif_device_list(dev_net(dev
));
377 if (!cfg
|| !caifdevs
)
380 caifd
= caif_get(dev
);
381 if (caifd
== NULL
&& dev
->type
!= ARPHRD_CAIF
)
385 case NETDEV_REGISTER
:
389 caifdev
= netdev_priv(dev
);
392 if (caifdev
->use_frag
) {
394 link_support
= cfserl_create(dev
->ifindex
,
397 pr_warn("Out of memory\n");
401 caif_enroll_dev(dev
, caifdev
, link_support
, head_room
,
403 caifdev
->flowctrl
= dev_flowctrl
;
409 caifd
= caif_get(dev
);
416 cfcnfg_set_phy_state(cfg
, &caifd
->layer
, true);
424 caifd
= caif_get(dev
);
425 if (!caifd
|| !caifd
->layer
.up
|| !caifd
->layer
.up
->ctrlcmd
) {
430 cfcnfg_set_phy_state(cfg
, &caifd
->layer
, false);
434 caifd
->layer
.up
->ctrlcmd(caifd
->layer
.up
,
435 _CAIF_CTRLCMD_PHYIF_DOWN_IND
,
438 spin_lock_bh(&caifd
->flow_lock
);
441 * Replace our xoff-destructor with original destructor.
442 * We trust that skb->destructor *always* is called before
443 * the skb reference is invalid. The hijacked SKB destructor
444 * takes the flow_lock so manipulating the skb->destructor here
447 if (caifd
->xoff_skb_dtor
!= NULL
&& caifd
->xoff_skb
!= NULL
)
448 caifd
->xoff_skb
->destructor
= caifd
->xoff_skb_dtor
;
451 caifd
->xoff_skb_dtor
= NULL
;
452 caifd
->xoff_skb
= NULL
;
454 spin_unlock_bh(&caifd
->flow_lock
);
458 case NETDEV_UNREGISTER
:
459 mutex_lock(&caifdevs
->lock
);
461 caifd
= caif_get(dev
);
463 mutex_unlock(&caifdevs
->lock
);
466 list_del_rcu(&caifd
->list
);
469 * NETDEV_UNREGISTER is called repeatedly until all reference
470 * counts for the net-device are released. If references to
471 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
472 * the next call to NETDEV_UNREGISTER.
474 * If any packets are in flight down the CAIF Stack,
475 * cfcnfg_del_phy_layer will return nonzero.
476 * If no packets are in flight, the CAIF Stack associated
477 * with the net-device un-registering is freed.
480 if (caifd_refcnt_read(caifd
) != 0 ||
481 cfcnfg_del_phy_layer(cfg
, &caifd
->layer
) != 0) {
483 pr_info("Wait for device inuse\n");
484 /* Enrole device if CAIF Stack is still in use */
485 list_add_rcu(&caifd
->list
, &caifdevs
->list
);
486 mutex_unlock(&caifdevs
->lock
);
491 dev_put(caifd
->netdev
);
492 free_percpu(caifd
->pcpu_refcnt
);
495 mutex_unlock(&caifdevs
->lock
);
501 static struct notifier_block caif_device_notifier
= {
502 .notifier_call
= caif_device_notify
,
506 /* Per-namespace Caif devices handling */
507 static int caif_init_net(struct net
*net
)
509 struct caif_net
*caifn
= net_generic(net
, caif_net_id
);
513 INIT_LIST_HEAD(&caifn
->caifdevs
.list
);
514 mutex_init(&caifn
->caifdevs
.lock
);
516 caifn
->cfg
= cfcnfg_create();
523 static void caif_exit_net(struct net
*net
)
525 struct caif_device_entry
*caifd
, *tmp
;
526 struct caif_device_entry_list
*caifdevs
=
527 caif_device_list(net
);
528 struct cfcnfg
*cfg
= get_cfcnfg(net
);
530 if (!cfg
|| !caifdevs
)
534 mutex_lock(&caifdevs
->lock
);
536 list_for_each_entry_safe(caifd
, tmp
, &caifdevs
->list
, list
) {
538 list_del_rcu(&caifd
->list
);
539 cfcnfg_set_phy_state(cfg
, &caifd
->layer
, false);
542 (caifd_refcnt_read(caifd
) != 0 ||
543 cfcnfg_del_phy_layer(cfg
, &caifd
->layer
) != 0)) {
545 pr_info("Wait for device inuse\n");
550 dev_put(caifd
->netdev
);
551 free_percpu(caifd
->pcpu_refcnt
);
556 mutex_unlock(&caifdevs
->lock
);
560 static struct pernet_operations caif_net_ops
= {
561 .init
= caif_init_net
,
562 .exit
= caif_exit_net
,
564 .size
= sizeof(struct caif_net
),
567 /* Initialize Caif devices list */
568 static int __init
caif_device_init(void)
572 result
= register_pernet_device(&caif_net_ops
);
577 register_netdevice_notifier(&caif_device_notifier
);
578 dev_add_pack(&caif_packet_type
);
583 static void __exit
caif_device_exit(void)
585 unregister_pernet_device(&caif_net_ops
);
586 unregister_netdevice_notifier(&caif_device_notifier
);
587 dev_remove_pack(&caif_packet_type
);
590 module_init(caif_device_init
);
591 module_exit(caif_device_exit
);