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 Remi Denis-Courmont
8 * and Sakari Ailus <sakari.ailus@nokia.com>
11 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
13 #include <linux/kernel.h>
14 #include <linux/if_arp.h>
15 #include <linux/net.h>
16 #include <linux/netdevice.h>
17 #include <linux/mutex.h>
18 #include <linux/module.h>
19 #include <linux/spinlock.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>
27 #include <net/caif/cfserl.h>
29 MODULE_LICENSE("GPL");
31 /* Used for local tracking of the CAIF net devices */
32 struct caif_device_entry
{
34 struct list_head list
;
35 struct net_device
*netdev
;
36 int __percpu
*pcpu_refcnt
;
38 struct sk_buff
*xoff_skb
;
39 void (*xoff_skb_dtor
)(struct sk_buff
*skb
);
43 struct caif_device_entry_list
{
44 struct list_head list
;
45 /* Protects simulanous deletes in list */
51 struct caif_device_entry_list caifdevs
;
54 static int caif_net_id
;
55 static int q_high
= 50; /* Percent */
57 struct cfcnfg
*get_cfcnfg(struct net
*net
)
59 struct caif_net
*caifn
;
60 caifn
= net_generic(net
, caif_net_id
);
63 EXPORT_SYMBOL(get_cfcnfg
);
65 static struct caif_device_entry_list
*caif_device_list(struct net
*net
)
67 struct caif_net
*caifn
;
68 caifn
= net_generic(net
, caif_net_id
);
69 return &caifn
->caifdevs
;
72 static void caifd_put(struct caif_device_entry
*e
)
74 this_cpu_dec(*e
->pcpu_refcnt
);
77 static void caifd_hold(struct caif_device_entry
*e
)
79 this_cpu_inc(*e
->pcpu_refcnt
);
82 static int caifd_refcnt_read(struct caif_device_entry
*e
)
85 for_each_possible_cpu(i
)
86 refcnt
+= *per_cpu_ptr(e
->pcpu_refcnt
, i
);
90 /* Allocate new CAIF device. */
91 static struct caif_device_entry
*caif_device_alloc(struct net_device
*dev
)
93 struct caif_device_entry_list
*caifdevs
;
94 struct caif_device_entry
*caifd
;
96 caifdevs
= caif_device_list(dev_net(dev
));
98 caifd
= kzalloc(sizeof(*caifd
), GFP_KERNEL
);
101 caifd
->pcpu_refcnt
= alloc_percpu(int);
102 if (!caifd
->pcpu_refcnt
) {
111 static struct caif_device_entry
*caif_get(struct net_device
*dev
)
113 struct caif_device_entry_list
*caifdevs
=
114 caif_device_list(dev_net(dev
));
115 struct caif_device_entry
*caifd
;
117 list_for_each_entry_rcu(caifd
, &caifdevs
->list
, list
) {
118 if (caifd
->netdev
== dev
)
124 void caif_flow_cb(struct sk_buff
*skb
)
126 struct caif_device_entry
*caifd
;
127 void (*dtor
)(struct sk_buff
*skb
) = NULL
;
130 WARN_ON(skb
->dev
== NULL
);
133 caifd
= caif_get(skb
->dev
);
137 spin_lock_bh(&caifd
->flow_lock
);
138 send_xoff
= caifd
->xoff
;
140 dtor
= caifd
->xoff_skb_dtor
;
142 if (WARN_ON(caifd
->xoff_skb
!= skb
))
145 caifd
->xoff_skb
= NULL
;
146 caifd
->xoff_skb_dtor
= NULL
;
148 spin_unlock_bh(&caifd
->flow_lock
);
155 ctrlcmd(caifd
->layer
.up
,
156 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND
,
161 static int transmit(struct cflayer
*layer
, struct cfpkt
*pkt
)
163 int err
, high
= 0, qlen
= 0;
164 struct caif_device_entry
*caifd
=
165 container_of(layer
, struct caif_device_entry
, layer
);
167 struct netdev_queue
*txq
;
171 skb
= cfpkt_tonative(pkt
);
172 skb
->dev
= caifd
->netdev
;
173 skb_reset_network_header(skb
);
174 skb
->protocol
= htons(ETH_P_CAIF
);
176 /* Check if we need to handle xoff */
177 if (likely(caifd
->netdev
->tx_queue_len
== 0))
180 if (unlikely(caifd
->xoff
))
183 if (likely(!netif_queue_stopped(caifd
->netdev
))) {
184 /* If we run with a TX queue, check if the queue is too long*/
185 txq
= netdev_get_tx_queue(skb
->dev
, 0);
186 qlen
= qdisc_qlen(rcu_dereference_bh(txq
->qdisc
));
188 if (likely(qlen
== 0))
191 high
= (caifd
->netdev
->tx_queue_len
* q_high
) / 100;
192 if (likely(qlen
< high
))
196 /* Hold lock while accessing xoff */
197 spin_lock_bh(&caifd
->flow_lock
);
199 spin_unlock_bh(&caifd
->flow_lock
);
204 * Handle flow off, we do this by temporary hi-jacking this
205 * skb's destructor function, and replace it with our own
206 * flow-on callback. The callback will set flow-on and call
207 * the original destructor.
210 pr_debug("queue has stopped(%d) or is full (%d > %d)\n",
211 netif_queue_stopped(caifd
->netdev
),
214 caifd
->xoff_skb
= skb
;
215 caifd
->xoff_skb_dtor
= skb
->destructor
;
216 skb
->destructor
= caif_flow_cb
;
217 spin_unlock_bh(&caifd
->flow_lock
);
219 caifd
->layer
.up
->ctrlcmd(caifd
->layer
.up
,
220 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND
,
223 rcu_read_unlock_bh();
225 err
= dev_queue_xmit(skb
);
233 * Stuff received packets into the CAIF stack.
234 * On error, returns non-zero and releases the skb.
236 static int receive(struct sk_buff
*skb
, struct net_device
*dev
,
237 struct packet_type
*pkttype
, struct net_device
*orig_dev
)
240 struct caif_device_entry
*caifd
;
243 pkt
= cfpkt_fromnative(CAIF_DIR_IN
, skb
);
246 caifd
= caif_get(dev
);
248 if (!caifd
|| !caifd
->layer
.up
|| !caifd
->layer
.up
->receive
||
249 !netif_oper_up(caifd
->netdev
)) {
255 /* Hold reference to netdevice while using CAIF stack */
259 err
= caifd
->layer
.up
->receive(caifd
->layer
.up
, pkt
);
261 /* For -EILSEQ the packet is not freed so so it now */
265 /* Release reference to stack upwards */
273 static struct packet_type caif_packet_type __read_mostly
= {
274 .type
= cpu_to_be16(ETH_P_CAIF
),
278 static void dev_flowctrl(struct net_device
*dev
, int on
)
280 struct caif_device_entry
*caifd
;
284 caifd
= caif_get(dev
);
285 if (!caifd
|| !caifd
->layer
.up
|| !caifd
->layer
.up
->ctrlcmd
) {
293 caifd
->layer
.up
->ctrlcmd(caifd
->layer
.up
,
295 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND
:
296 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND
,
301 void caif_enroll_dev(struct net_device
*dev
, struct caif_dev_common
*caifdev
,
302 struct cflayer
*link_support
, int head_room
,
303 struct cflayer
**layer
, int (**rcv_func
)(
304 struct sk_buff
*, struct net_device
*,
305 struct packet_type
*, struct net_device
*))
307 struct caif_device_entry
*caifd
;
308 enum cfcnfg_phy_preference pref
;
309 struct cfcnfg
*cfg
= get_cfcnfg(dev_net(dev
));
310 struct caif_device_entry_list
*caifdevs
;
312 caifdevs
= caif_device_list(dev_net(dev
));
313 caifd
= caif_device_alloc(dev
);
316 *layer
= &caifd
->layer
;
317 spin_lock_init(&caifd
->flow_lock
);
319 switch (caifdev
->link_select
) {
320 case CAIF_LINK_HIGH_BANDW
:
321 pref
= CFPHYPREF_HIGH_BW
;
323 case CAIF_LINK_LOW_LATENCY
:
324 pref
= CFPHYPREF_LOW_LAT
;
327 pref
= CFPHYPREF_HIGH_BW
;
330 mutex_lock(&caifdevs
->lock
);
331 list_add_rcu(&caifd
->list
, &caifdevs
->list
);
333 strncpy(caifd
->layer
.name
, dev
->name
,
334 sizeof(caifd
->layer
.name
) - 1);
335 caifd
->layer
.name
[sizeof(caifd
->layer
.name
) - 1] = 0;
336 caifd
->layer
.transmit
= transmit
;
337 cfcnfg_add_phy_layer(cfg
,
344 mutex_unlock(&caifdevs
->lock
);
348 EXPORT_SYMBOL(caif_enroll_dev
);
350 /* notify Caif of device events */
351 static int caif_device_notify(struct notifier_block
*me
, unsigned long what
,
354 struct net_device
*dev
= arg
;
355 struct caif_device_entry
*caifd
= NULL
;
356 struct caif_dev_common
*caifdev
;
358 struct cflayer
*layer
, *link_support
;
360 struct caif_device_entry_list
*caifdevs
;
362 cfg
= get_cfcnfg(dev_net(dev
));
363 caifdevs
= caif_device_list(dev_net(dev
));
365 caifd
= caif_get(dev
);
366 if (caifd
== NULL
&& dev
->type
!= ARPHRD_CAIF
)
370 case NETDEV_REGISTER
:
374 caifdev
= netdev_priv(dev
);
377 if (caifdev
->use_frag
) {
379 link_support
= cfserl_create(dev
->ifindex
,
382 pr_warn("Out of memory\n");
386 caif_enroll_dev(dev
, caifdev
, link_support
, head_room
,
388 caifdev
->flowctrl
= dev_flowctrl
;
394 caifd
= caif_get(dev
);
401 cfcnfg_set_phy_state(cfg
, &caifd
->layer
, true);
409 caifd
= caif_get(dev
);
410 if (!caifd
|| !caifd
->layer
.up
|| !caifd
->layer
.up
->ctrlcmd
) {
415 cfcnfg_set_phy_state(cfg
, &caifd
->layer
, false);
419 caifd
->layer
.up
->ctrlcmd(caifd
->layer
.up
,
420 _CAIF_CTRLCMD_PHYIF_DOWN_IND
,
423 spin_lock_bh(&caifd
->flow_lock
);
426 * Replace our xoff-destructor with original destructor.
427 * We trust that skb->destructor *always* is called before
428 * the skb reference is invalid. The hijacked SKB destructor
429 * takes the flow_lock so manipulating the skb->destructor here
432 if (caifd
->xoff_skb_dtor
!= NULL
&& caifd
->xoff_skb
!= NULL
)
433 caifd
->xoff_skb
->destructor
= caifd
->xoff_skb_dtor
;
436 caifd
->xoff_skb_dtor
= NULL
;
437 caifd
->xoff_skb
= NULL
;
439 spin_unlock_bh(&caifd
->flow_lock
);
443 case NETDEV_UNREGISTER
:
444 mutex_lock(&caifdevs
->lock
);
446 caifd
= caif_get(dev
);
448 mutex_unlock(&caifdevs
->lock
);
451 list_del_rcu(&caifd
->list
);
454 * NETDEV_UNREGISTER is called repeatedly until all reference
455 * counts for the net-device are released. If references to
456 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
457 * the next call to NETDEV_UNREGISTER.
459 * If any packets are in flight down the CAIF Stack,
460 * cfcnfg_del_phy_layer will return nonzero.
461 * If no packets are in flight, the CAIF Stack associated
462 * with the net-device un-registering is freed.
465 if (caifd_refcnt_read(caifd
) != 0 ||
466 cfcnfg_del_phy_layer(cfg
, &caifd
->layer
) != 0) {
468 pr_info("Wait for device inuse\n");
469 /* Enrole device if CAIF Stack is still in use */
470 list_add_rcu(&caifd
->list
, &caifdevs
->list
);
471 mutex_unlock(&caifdevs
->lock
);
476 dev_put(caifd
->netdev
);
477 free_percpu(caifd
->pcpu_refcnt
);
480 mutex_unlock(&caifdevs
->lock
);
486 static struct notifier_block caif_device_notifier
= {
487 .notifier_call
= caif_device_notify
,
491 /* Per-namespace Caif devices handling */
492 static int caif_init_net(struct net
*net
)
494 struct caif_net
*caifn
= net_generic(net
, caif_net_id
);
495 INIT_LIST_HEAD(&caifn
->caifdevs
.list
);
496 mutex_init(&caifn
->caifdevs
.lock
);
498 caifn
->cfg
= cfcnfg_create();
505 static void caif_exit_net(struct net
*net
)
507 struct caif_device_entry
*caifd
, *tmp
;
508 struct caif_device_entry_list
*caifdevs
=
509 caif_device_list(net
);
510 struct cfcnfg
*cfg
= get_cfcnfg(net
);
513 mutex_lock(&caifdevs
->lock
);
515 list_for_each_entry_safe(caifd
, tmp
, &caifdevs
->list
, list
) {
517 list_del_rcu(&caifd
->list
);
518 cfcnfg_set_phy_state(cfg
, &caifd
->layer
, false);
521 (caifd_refcnt_read(caifd
) != 0 ||
522 cfcnfg_del_phy_layer(cfg
, &caifd
->layer
) != 0)) {
524 pr_info("Wait for device inuse\n");
529 dev_put(caifd
->netdev
);
530 free_percpu(caifd
->pcpu_refcnt
);
535 mutex_unlock(&caifdevs
->lock
);
539 static struct pernet_operations caif_net_ops
= {
540 .init
= caif_init_net
,
541 .exit
= caif_exit_net
,
543 .size
= sizeof(struct caif_net
),
546 /* Initialize Caif devices list */
547 static int __init
caif_device_init(void)
551 result
= register_pernet_subsys(&caif_net_ops
);
556 register_netdevice_notifier(&caif_device_notifier
);
557 dev_add_pack(&caif_packet_type
);
562 static void __exit
caif_device_exit(void)
564 unregister_pernet_subsys(&caif_net_ops
);
565 unregister_netdevice_notifier(&caif_device_notifier
);
566 dev_remove_pack(&caif_packet_type
);
569 module_init(caif_device_init
);
570 module_exit(caif_device_exit
);