/* * 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 <linux/module.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_KERNEL);	if (!caifd)		return NULL;	caifd->pcpu_refcnt = alloc_percpu(int);	if (!caifd->pcpu_refcnt) {		kfree(caifd);		return NULL;	}	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; 	if (dev->type != ARPHRD_CAIF)		return 0; 	cfg = get_cfcnfg(dev_net(dev));	if (cfg == NULL)		return 0; 	caifdevs = caif_device_list(dev_net(dev)); 	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);