[deliverable/linux.git] / net / caif / caif_dev.c

/*
 * CAIF Interface registration.
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
 * License terms: GNU General Public License (GPL) version 2
 *
 * Borrowed heavily from file: pn_dev.c. Thanks to
 *  Remi Denis-Courmont <remi.denis-courmont@nokia.com>
 *  and Sakari Ailus <sakari.ailus@nokia.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

#include <linux/kernel.h>
#include <linux/if_arp.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/mutex.h>
#include <net/netns/generic.h>
#include <net/net_namespace.h>
#include <net/pkt_sched.h>
#include <net/caif/caif_device.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfcnfg.h>

MODULE_LICENSE("GPL");

/* Used for local tracking of the CAIF net devices */
struct caif_device_entry {
	struct cflayer layer;
	struct list_head list;
	struct net_device *netdev;
	int __percpu *pcpu_refcnt;
};

struct caif_device_entry_list {
	struct list_head list;
	/* Protects simulanous deletes in list */
	struct mutex lock;
};

struct caif_net {
	struct cfcnfg *cfg;
	struct caif_device_entry_list caifdevs;
};

static int caif_net_id;

struct cfcnfg *get_cfcnfg(struct net *net)
{
	struct caif_net *caifn;
	BUG_ON(!net);
	caifn = net_generic(net, caif_net_id);
	BUG_ON(!caifn);
	return caifn->cfg;
}
EXPORT_SYMBOL(get_cfcnfg);

static struct caif_device_entry_list *caif_device_list(struct net *net)
{
	struct caif_net *caifn;
	BUG_ON(!net);
	caifn = net_generic(net, caif_net_id);
	BUG_ON(!caifn);
	return &caifn->caifdevs;
}

static void caifd_put(struct caif_device_entry *e)
{
	irqsafe_cpu_dec(*e->pcpu_refcnt);
}

static void caifd_hold(struct caif_device_entry *e)
{
	irqsafe_cpu_inc(*e->pcpu_refcnt);
}

static int caifd_refcnt_read(struct caif_device_entry *e)
{
	int i, refcnt = 0;
	for_each_possible_cpu(i)
		refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
	return refcnt;
}

/* Allocate new CAIF device. */
static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
{
	struct caif_device_entry_list *caifdevs;
	struct caif_device_entry *caifd;

	caifdevs = caif_device_list(dev_net(dev));
	BUG_ON(!caifdevs);

	caifd = kzalloc(sizeof(*caifd), GFP_ATOMIC);
	if (!caifd)
		return NULL;
	caifd->pcpu_refcnt = alloc_percpu(int);
	caifd->netdev = dev;
	dev_hold(dev);
	return caifd;
}

static struct caif_device_entry *caif_get(struct net_device *dev)
{
	struct caif_device_entry_list *caifdevs =
	    caif_device_list(dev_net(dev));
	struct caif_device_entry *caifd;
	BUG_ON(!caifdevs);
	list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
		if (caifd->netdev == dev)
			return caifd;
	}
	return NULL;
}

static int transmit(struct cflayer *layer, struct cfpkt *pkt)
{
	int err;
	struct caif_device_entry *caifd =
	    container_of(layer, struct caif_device_entry, layer);
	struct sk_buff *skb;

	skb = cfpkt_tonative(pkt);
	skb->dev = caifd->netdev;

	err = dev_queue_xmit(skb);
	if (err > 0)
		err = -EIO;

	return err;
}

/*
 * Stuff received packets into the CAIF stack.
 * On error, returns non-zero and releases the skb.
 */
static int receive(struct sk_buff *skb, struct net_device *dev,
		   struct packet_type *pkttype, struct net_device *orig_dev)
{
	struct cfpkt *pkt;
	struct caif_device_entry *caifd;
	int err;

	pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);

	rcu_read_lock();
	caifd = caif_get(dev);

	if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
			!netif_oper_up(caifd->netdev)) {
		rcu_read_unlock();
		kfree_skb(skb);
		return NET_RX_DROP;
	}

	/* Hold reference to netdevice while using CAIF stack */
	caifd_hold(caifd);
	rcu_read_unlock();

	err = caifd->layer.up->receive(caifd->layer.up, pkt);

	/* For -EILSEQ the packet is not freed so so it now */
	if (err == -EILSEQ)
		cfpkt_destroy(pkt);

	/* Release reference to stack upwards */
	caifd_put(caifd);
	return 0;
}

static struct packet_type caif_packet_type __read_mostly = {
	.type = cpu_to_be16(ETH_P_CAIF),
	.func = receive,
};

static void dev_flowctrl(struct net_device *dev, int on)
{
	struct caif_device_entry *caifd;

	rcu_read_lock();

	caifd = caif_get(dev);
	if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
		rcu_read_unlock();
		return;
	}

	caifd_hold(caifd);
	rcu_read_unlock();

	caifd->layer.up->ctrlcmd(caifd->layer.up,
				 on ?
				 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
				 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
				 caifd->layer.id);
	caifd_put(caifd);
}

/* notify Caif of device events */
static int caif_device_notify(struct notifier_block *me, unsigned long what,
			      void *arg)
{
	struct net_device *dev = arg;
	struct caif_device_entry *caifd = NULL;
	struct caif_dev_common *caifdev;
	enum cfcnfg_phy_preference pref;
	enum cfcnfg_phy_type phy_type;
	struct cfcnfg *cfg;
	struct caif_device_entry_list *caifdevs =
	    caif_device_list(dev_net(dev));

	if (dev->type != ARPHRD_CAIF)
		return 0;

	cfg = get_cfcnfg(dev_net(dev));
	if (cfg == NULL)
		return 0;

	switch (what) {
	case NETDEV_REGISTER:
		caifd = caif_device_alloc(dev);
		if (!caifd)
			return 0;

		caifdev = netdev_priv(dev);
		caifdev->flowctrl = dev_flowctrl;

		caifd->layer.transmit = transmit;

		if (caifdev->use_frag)
			phy_type = CFPHYTYPE_FRAG;
		else
			phy_type = CFPHYTYPE_CAIF;

		switch (caifdev->link_select) {
		case CAIF_LINK_HIGH_BANDW:
			pref = CFPHYPREF_HIGH_BW;
			break;
		case CAIF_LINK_LOW_LATENCY:
			pref = CFPHYPREF_LOW_LAT;
			break;
		default:
			pref = CFPHYPREF_HIGH_BW;
			break;
		}
		strncpy(caifd->layer.name, dev->name,
			sizeof(caifd->layer.name) - 1);
		caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;

		mutex_lock(&caifdevs->lock);
		list_add_rcu(&caifd->list, &caifdevs->list);

		cfcnfg_add_phy_layer(cfg,
				     phy_type,
				     dev,
				     &caifd->layer,
				     pref,
				     caifdev->use_fcs,
				     caifdev->use_stx);
		mutex_unlock(&caifdevs->lock);
		break;

	case NETDEV_UP:
		rcu_read_lock();

		caifd = caif_get(dev);
		if (caifd == NULL) {
			rcu_read_unlock();
			break;
		}

		cfcnfg_set_phy_state(cfg, &caifd->layer, true);
		rcu_read_unlock();

		break;

	case NETDEV_DOWN:
		rcu_read_lock();

		caifd = caif_get(dev);
		if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
			rcu_read_unlock();
			return -EINVAL;
		}

		cfcnfg_set_phy_state(cfg, &caifd->layer, false);
		caifd_hold(caifd);
		rcu_read_unlock();

		caifd->layer.up->ctrlcmd(caifd->layer.up,
					 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
					 caifd->layer.id);
		caifd_put(caifd);
		break;

	case NETDEV_UNREGISTER:
		mutex_lock(&caifdevs->lock);

		caifd = caif_get(dev);
		if (caifd == NULL) {
			mutex_unlock(&caifdevs->lock);
			break;
		}
		list_del_rcu(&caifd->list);

		/*
		 * NETDEV_UNREGISTER is called repeatedly until all reference
		 * counts for the net-device are released. If references to
		 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
		 * the next call to NETDEV_UNREGISTER.
		 *
		 * If any packets are in flight down the CAIF Stack,
		 * cfcnfg_del_phy_layer will return nonzero.
		 * If no packets are in flight, the CAIF Stack associated
		 * with the net-device un-registering is freed.
		 */

		if (caifd_refcnt_read(caifd) != 0 ||
			cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {

			pr_info("Wait for device inuse\n");
			/* Enrole device if CAIF Stack is still in use */
			list_add_rcu(&caifd->list, &caifdevs->list);
			mutex_unlock(&caifdevs->lock);
			break;
		}

		synchronize_rcu();
		dev_put(caifd->netdev);
		free_percpu(caifd->pcpu_refcnt);
		kfree(caifd);

		mutex_unlock(&caifdevs->lock);
		break;
	}
	return 0;
}

static struct notifier_block caif_device_notifier = {
	.notifier_call = caif_device_notify,
	.priority = 0,
};

/* Per-namespace Caif devices handling */
static int caif_init_net(struct net *net)
{
	struct caif_net *caifn = net_generic(net, caif_net_id);
	BUG_ON(!caifn);
	INIT_LIST_HEAD(&caifn->caifdevs.list);
	mutex_init(&caifn->caifdevs.lock);

	caifn->cfg = cfcnfg_create();
	if (!caifn->cfg) {
		pr_warn("can't create cfcnfg\n");
		return -ENOMEM;
	}

	return 0;
}

static void caif_exit_net(struct net *net)
{
	struct caif_device_entry *caifd, *tmp;
	struct caif_device_entry_list *caifdevs =
	    caif_device_list(net);
	struct cfcnfg *cfg;

	rtnl_lock();
	mutex_lock(&caifdevs->lock);

	cfg = get_cfcnfg(net);
	if (cfg == NULL) {
		mutex_unlock(&caifdevs->lock);
		return;
	}

	list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
		int i = 0;
		list_del_rcu(&caifd->list);
		cfcnfg_set_phy_state(cfg, &caifd->layer, false);

		while (i < 10 &&
			(caifd_refcnt_read(caifd) != 0 ||
			cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {

			pr_info("Wait for device inuse\n");
			msleep(250);
			i++;
		}
		synchronize_rcu();
		dev_put(caifd->netdev);
		free_percpu(caifd->pcpu_refcnt);
		kfree(caifd);
	}
	cfcnfg_remove(cfg);

	mutex_unlock(&caifdevs->lock);
	rtnl_unlock();
}

static struct pernet_operations caif_net_ops = {
	.init = caif_init_net,
	.exit = caif_exit_net,
	.id   = &caif_net_id,
	.size = sizeof(struct caif_net),
};

/* Initialize Caif devices list */
static int __init caif_device_init(void)
{
	int result;

	result = register_pernet_device(&caif_net_ops);

	if (result)
		return result;

	register_netdevice_notifier(&caif_device_notifier);
	dev_add_pack(&caif_packet_type);

	return result;
}

static void __exit caif_device_exit(void)
{
	unregister_pernet_device(&caif_net_ops);
	unregister_netdevice_notifier(&caif_device_notifier);
	dev_remove_pack(&caif_packet_type);
}

module_init(caif_device_init);
module_exit(caif_device_exit);
Commit	Line	Data
c72dfae2 SB	1	/*
	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	*
	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>
	10	*/
	11
b31fa5ba JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
b31fa5ba JP	13
c72dfae2 SB	14	#include <linux/kernel.h>
	15	#include <linux/if_arp.h>
	16	#include <linux/net.h>
	17	#include <linux/netdevice.h>
bd30ce4b	18	#include <linux/mutex.h>
c72dfae2 SB	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>
c72dfae2 SB	23	#include <net/caif/caif_layer.h>
	24	#include <net/caif/cfpkt.h>
	25	#include <net/caif/cfcnfg.h>
	26
	27	MODULE_LICENSE("GPL");
c72dfae2 SB	28
	29	/* Used for local tracking of the CAIF net devices */
	30	struct caif_device_entry {
	31	struct cflayer layer;
	32	struct list_head list;
c72dfae2	33	struct net_device *netdev;
bd30ce4b	34	int __percpu *pcpu_refcnt;
c72dfae2 SB	35	};
	36
	37	struct caif_device_entry_list {
	38	struct list_head list;
	39	/* Protects simulanous deletes in list */
bd30ce4b	40	struct mutex lock;
c72dfae2 SB	41	};
	42
	43	struct caif_net {
bee925db	44	struct cfcnfg *cfg;
c72dfae2 SB	45	struct caif_device_entry_list caifdevs;
	46	};
	47
	48	static int caif_net_id;
bee925db	49
	50	struct cfcnfg get_cfcnfg(struct net net)
	51	{
	52	struct caif_net *caifn;
	53	BUG_ON(!net);
	54	caifn = net_generic(net, caif_net_id);
	55	BUG_ON(!caifn);
	56	return caifn->cfg;
	57	}
	58	EXPORT_SYMBOL(get_cfcnfg);
c72dfae2 SB	59
	60	static struct caif_device_entry_list caif_device_list(struct net net)
	61	{
	62	struct caif_net *caifn;
	63	BUG_ON(!net);
	64	caifn = net_generic(net, caif_net_id);
	65	BUG_ON(!caifn);
	66	return &caifn->caifdevs;
	67	}
	68
bd30ce4b	69	static void caifd_put(struct caif_device_entry *e)
	70	{
	71	irqsafe_cpu_dec(*e->pcpu_refcnt);
	72	}
	73
	74	static void caifd_hold(struct caif_device_entry *e)
	75	{
	76	irqsafe_cpu_inc(*e->pcpu_refcnt);
	77	}
	78
	79	static int caifd_refcnt_read(struct caif_device_entry *e)
	80	{
	81	int i, refcnt = 0;
	82	for_each_possible_cpu(i)
	83	refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
	84	return refcnt;
	85	}
	86
c72dfae2 SB	87	/* Allocate new CAIF device. */
	88	static struct caif_device_entry caif_device_alloc(struct net_device dev)
	89	{
	90	struct caif_device_entry_list *caifdevs;
	91	struct caif_device_entry *caifd;
bd30ce4b	92
c72dfae2 SB	93	caifdevs = caif_device_list(dev_net(dev));
c72dfae2 SB	94	BUG_ON(!caifdevs);
bd30ce4b	95
c72dfae2 SB	96	caifd = kzalloc(sizeof(*caifd), GFP_ATOMIC);
	97	if (!caifd)
	98	return NULL;
bd30ce4b	99	caifd->pcpu_refcnt = alloc_percpu(int);
c72dfae2	100	caifd->netdev = dev;
bd30ce4b	101	dev_hold(dev);
c72dfae2 SB	102	return caifd;
	103	}
	104
	105	static struct caif_device_entry caif_get(struct net_device dev)
	106	{
	107	struct caif_device_entry_list *caifdevs =
	108	caif_device_list(dev_net(dev));
	109	struct caif_device_entry *caifd;
	110	BUG_ON(!caifdevs);
bd30ce4b	111	list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
c72dfae2 SB	112	if (caifd->netdev == dev)
	113	return caifd;
	114	}
	115	return NULL;
	116	}
	117
c72dfae2 SB	118	static int transmit(struct cflayer layer, struct cfpkt pkt)
c72dfae2 SB	119	{
c85c2951	120	int err;
c72dfae2 SB	121	struct caif_device_entry *caifd =
c72dfae2 SB	122	container_of(layer, struct caif_device_entry, layer);
4dd820c0 SB	123	struct sk_buff *skb;
4dd820c0 SB	124
c72dfae2 SB	125	skb = cfpkt_tonative(pkt);
c72dfae2 SB	126	skb->dev = caifd->netdev;
4dd820c0	127
c85c2951	128	err = dev_queue_xmit(skb);
	129	if (err > 0)
	130	err = -EIO;
c72dfae2	131
c85c2951	132	return err;
c72dfae2 SB	133	}
c72dfae2 SB	134
c72dfae2	135	/*
bd30ce4b	136	* Stuff received packets into the CAIF stack.
c72dfae2 SB	137	* On error, returns non-zero and releases the skb.
	138	*/
	139	static int receive(struct sk_buff skb, struct net_device dev,
	140	struct packet_type pkttype, struct net_device orig_dev)
	141	{
c72dfae2 SB	142	struct cfpkt *pkt;
c72dfae2 SB	143	struct caif_device_entry *caifd;
69c867c9	144	int err;
bd30ce4b	145
c72dfae2	146	pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
bd30ce4b	147
bd30ce4b	148	rcu_read_lock();
c72dfae2	149	caifd = caif_get(dev);
c72dfae2	150
bd30ce4b	151	if (!caifd \|\| !caifd->layer.up \|\| !caifd->layer.up->receive \|\|
	152	!netif_oper_up(caifd->netdev)) {
	153	rcu_read_unlock();
	154	kfree_skb(skb);
c72dfae2	155	return NET_RX_DROP;
bd30ce4b	156	}
	157
	158	/* Hold reference to netdevice while using CAIF stack */
	159	caifd_hold(caifd);
	160	rcu_read_unlock();
c72dfae2	161
69c867c9	162	err = caifd->layer.up->receive(caifd->layer.up, pkt);
	163
	164	/* For -EILSEQ the packet is not freed so so it now */
	165	if (err == -EILSEQ)
	166	cfpkt_destroy(pkt);
bd30ce4b	167
	168	/* Release reference to stack upwards */
	169	caifd_put(caifd);
c72dfae2 SB	170	return 0;
	171	}
	172
	173	static struct packet_type caif_packet_type __read_mostly = {
	174	.type = cpu_to_be16(ETH_P_CAIF),
	175	.func = receive,
	176	};
	177
	178	static void dev_flowctrl(struct net_device *dev, int on)
	179	{
bd30ce4b	180	struct caif_device_entry *caifd;
	181
	182	rcu_read_lock();
	183
	184	caifd = caif_get(dev);
	185	if (!caifd \|\| !caifd->layer.up \|\| !caifd->layer.up->ctrlcmd) {
	186	rcu_read_unlock();
c72dfae2	187	return;
bd30ce4b	188	}
	189
	190	caifd_hold(caifd);
	191	rcu_read_unlock();
c72dfae2 SB	192
	193	caifd->layer.up->ctrlcmd(caifd->layer.up,
	194	on ?
	195	_CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
	196	_CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
	197	caifd->layer.id);
bd30ce4b	198	caifd_put(caifd);
c72dfae2 SB	199	}
	200
	201	/* notify Caif of device events */
	202	static int caif_device_notify(struct notifier_block *me, unsigned long what,
	203	void *arg)
	204	{
	205	struct net_device *dev = arg;
	206	struct caif_device_entry *caifd = NULL;
	207	struct caif_dev_common *caifdev;
	208	enum cfcnfg_phy_preference pref;
c72dfae2	209	enum cfcnfg_phy_type phy_type;
bee925db	210	struct cfcnfg *cfg;
bd30ce4b	211	struct caif_device_entry_list *caifdevs =
bd30ce4b	212	caif_device_list(dev_net(dev));
c72dfae2 SB	213
	214	if (dev->type != ARPHRD_CAIF)
	215	return 0;
	216
bee925db	217	cfg = get_cfcnfg(dev_net(dev));
	218	if (cfg == NULL)
	219	return 0;
	220
c72dfae2 SB	221	switch (what) {
c72dfae2 SB	222	case NETDEV_REGISTER:
c72dfae2	223	caifd = caif_device_alloc(dev);
bd30ce4b	224	if (!caifd)
	225	return 0;
	226
c72dfae2 SB	227	caifdev = netdev_priv(dev);
c72dfae2 SB	228	caifdev->flowctrl = dev_flowctrl;
c72dfae2	229
c72dfae2	230	caifd->layer.transmit = transmit;
c72dfae2 SB	231
	232	if (caifdev->use_frag)
	233	phy_type = CFPHYTYPE_FRAG;
	234	else
	235	phy_type = CFPHYTYPE_CAIF;
	236
	237	switch (caifdev->link_select) {
	238	case CAIF_LINK_HIGH_BANDW:
2c485209	239	pref = CFPHYPREF_HIGH_BW;
c72dfae2 SB	240	break;
c72dfae2 SB	241	case CAIF_LINK_LOW_LATENCY:
2c485209	242	pref = CFPHYPREF_LOW_LAT;
c72dfae2 SB	243	break;
	244	default:
	245	pref = CFPHYPREF_HIGH_BW;
	246	break;
	247	}
bd30ce4b	248	strncpy(caifd->layer.name, dev->name,
	249	sizeof(caifd->layer.name) - 1);
	250	caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
	251
	252	mutex_lock(&caifdevs->lock);
	253	list_add_rcu(&caifd->list, &caifdevs->list);
	254
73d6ac63	255	cfcnfg_add_phy_layer(cfg,
c72dfae2 SB	256	phy_type,
	257	dev,
	258	&caifd->layer,
c72dfae2 SB	259	pref,
	260	caifdev->use_fcs,
	261	caifdev->use_stx);
bd30ce4b	262	mutex_unlock(&caifdevs->lock);
c72dfae2 SB	263	break;
c72dfae2 SB	264
bd30ce4b	265	case NETDEV_UP:
	266	rcu_read_lock();
	267
c72dfae2	268	caifd = caif_get(dev);
bd30ce4b	269	if (caifd == NULL) {
bd30ce4b	270	rcu_read_unlock();
c72dfae2	271	break;
bd30ce4b	272	}
c72dfae2	273
bd30ce4b	274	cfcnfg_set_phy_state(cfg, &caifd->layer, true);
bd30ce4b	275	rcu_read_unlock();
c72dfae2	276
c72dfae2 SB	277	break;
	278
	279	case NETDEV_DOWN:
bd30ce4b	280	rcu_read_lock();
bd30ce4b	281
c72dfae2	282	caifd = caif_get(dev);
bd30ce4b	283	if (!caifd \|\| !caifd->layer.up \|\| !caifd->layer.up->ctrlcmd) {
	284	rcu_read_unlock();
	285	return -EINVAL;
	286	}
	287
	288	cfcnfg_set_phy_state(cfg, &caifd->layer, false);
	289	caifd_hold(caifd);
	290	rcu_read_unlock();
	291
	292	caifd->layer.up->ctrlcmd(caifd->layer.up,
	293	_CAIF_CTRLCMD_PHYIF_DOWN_IND,
	294	caifd->layer.id);
	295	caifd_put(caifd);
c72dfae2 SB	296	break;
	297
	298	case NETDEV_UNREGISTER:
bd30ce4b	299	mutex_lock(&caifdevs->lock);
bd30ce4b	300
c72dfae2	301	caifd = caif_get(dev);
bd30ce4b	302	if (caifd == NULL) {
bd30ce4b	303	mutex_unlock(&caifdevs->lock);
f2527ec4	304	break;
bd30ce4b	305	}
	306	list_del_rcu(&caifd->list);
	307
	308	/*
	309	* NETDEV_UNREGISTER is called repeatedly until all reference
	310	* counts for the net-device are released. If references to
	311	* caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
	312	* the next call to NETDEV_UNREGISTER.
	313	*
	314	* If any packets are in flight down the CAIF Stack,
	315	* cfcnfg_del_phy_layer will return nonzero.
	316	* If no packets are in flight, the CAIF Stack associated
	317	* with the net-device un-registering is freed.
	318	*/
	319
	320	if (caifd_refcnt_read(caifd) != 0 \|\|
	321	cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
	322
	323	pr_info("Wait for device inuse\n");
	324	/* Enrole device if CAIF Stack is still in use */
	325	list_add_rcu(&caifd->list, &caifdevs->list);
	326	mutex_unlock(&caifdevs->lock);
	327	break;
	328	}
	329
	330	synchronize_rcu();
	331	dev_put(caifd->netdev);
	332	free_percpu(caifd->pcpu_refcnt);
	333	kfree(caifd);
	334
	335	mutex_unlock(&caifdevs->lock);
c72dfae2 SB	336	break;
	337	}
	338	return 0;
	339	}
	340
	341	static struct notifier_block caif_device_notifier = {
	342	.notifier_call = caif_device_notify,
	343	.priority = 0,
	344	};
	345
c72dfae2 SB	346	/* Per-namespace Caif devices handling */
	347	static int caif_init_net(struct net *net)
	348	{
	349	struct caif_net *caifn = net_generic(net, caif_net_id);
bee925db	350	BUG_ON(!caifn);
c72dfae2	351	INIT_LIST_HEAD(&caifn->caifdevs.list);
bd30ce4b	352	mutex_init(&caifn->caifdevs.lock);
bee925db	353
	354	caifn->cfg = cfcnfg_create();
	355	if (!caifn->cfg) {
	356	pr_warn("can't create cfcnfg\n");
	357	return -ENOMEM;
	358	}
	359
c72dfae2 SB	360	return 0;
	361	}
	362
	363	static void caif_exit_net(struct net *net)
	364	{
bd30ce4b	365	struct caif_device_entry caifd, tmp;
	366	struct caif_device_entry_list *caifdevs =
	367	caif_device_list(net);
bee925db	368	struct cfcnfg *cfg;
bd30ce4b	369
c72dfae2	370	rtnl_lock();
bd30ce4b	371	mutex_lock(&caifdevs->lock);
bd30ce4b	372
bee925db	373	cfg = get_cfcnfg(net);
	374	if (cfg == NULL) {
	375	mutex_unlock(&caifdevs->lock);
	376	return;
	377	}
	378
bd30ce4b	379	list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
	380	int i = 0;
	381	list_del_rcu(&caifd->list);
	382	cfcnfg_set_phy_state(cfg, &caifd->layer, false);
	383
	384	while (i < 10 &&
	385	(caifd_refcnt_read(caifd) != 0 \|\|
	386	cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
	387
	388	pr_info("Wait for device inuse\n");
	389	msleep(250);
	390	i++;
	391	}
	392	synchronize_rcu();
	393	dev_put(caifd->netdev);
	394	free_percpu(caifd->pcpu_refcnt);
	395	kfree(caifd);
c72dfae2	396	}
bee925db	397	cfcnfg_remove(cfg);
bd30ce4b	398
bd30ce4b	399	mutex_unlock(&caifdevs->lock);
c72dfae2 SB	400	rtnl_unlock();
	401	}
	402
	403	static struct pernet_operations caif_net_ops = {
	404	.init = caif_init_net,
	405	.exit = caif_exit_net,
	406	.id = &caif_net_id,
	407	.size = sizeof(struct caif_net),
	408	};
	409
	410	/* Initialize Caif devices list */
	411	static int __init caif_device_init(void)
	412	{
	413	int result;
bd30ce4b	414
c72dfae2 SB	415	result = register_pernet_device(&caif_net_ops);
c72dfae2 SB	416
bee925db	417	if (result)
c72dfae2	418	return result;
bee925db	419
c72dfae2	420	register_netdevice_notifier(&caif_device_notifier);
bee925db	421	dev_add_pack(&caif_packet_type);
c72dfae2 SB	422
c72dfae2 SB	423	return result;
c72dfae2 SB	424	}
	425
	426	static void __exit caif_device_exit(void)
	427	{
c72dfae2 SB	428	unregister_pernet_device(&caif_net_ops);
c72dfae2 SB	429	unregister_netdevice_notifier(&caif_device_notifier);
bee925db	430	dev_remove_pack(&caif_packet_type);
c72dfae2 SB	431	}
	432
	433	module_init(caif_device_init);
	434	module_exit(caif_device_exit);