linux/net/caif/caif_dev.c

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/*
* 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/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/if_arp.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/sched.h>
#include <linux/wait.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_dev.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfcnfg.h>
MODULE_LICENSE("GPL");
#define TIMEOUT (HZ*5)
/* Used for local tracking of the CAIF net devices */
struct caif_device_entry {
struct cflayer layer;
struct list_head list;
atomic_t in_use;
atomic_t state;
u16 phyid;
struct net_device *netdev;
wait_queue_head_t event;
};
struct caif_device_entry_list {
struct list_head list;
/* Protects simulanous deletes in list */
spinlock_t lock;
};
struct caif_net {
struct caif_device_entry_list caifdevs;
};
static int caif_net_id;
static struct cfcnfg *cfg;
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;
}
/* 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->netdev = dev;
list_add(&caifd->list, &caifdevs->list);
init_waitqueue_head(&caifd->event);
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(caifd, &caifdevs->list, list) {
if (caifd->netdev == dev)
return caifd;
}
return NULL;
}
static void caif_device_destroy(struct net_device *dev)
{
struct caif_device_entry_list *caifdevs =
caif_device_list(dev_net(dev));
struct caif_device_entry *caifd;
ASSERT_RTNL();
if (dev->type != ARPHRD_CAIF)
return;
spin_lock_bh(&caifdevs->lock);
caifd = caif_get(dev);
if (caifd == NULL) {
spin_unlock_bh(&caifdevs->lock);
return;
}
list_del(&caifd->list);
spin_unlock_bh(&caifdevs->lock);
kfree(caifd);
}
static int transmit(struct cflayer *layer, struct cfpkt *pkt)
{
struct caif_device_entry *caifd =
container_of(layer, struct caif_device_entry, layer);
struct sk_buff *skb, *skb2;
int ret = -EINVAL;
skb = cfpkt_tonative(pkt);
skb->dev = caifd->netdev;
/*
* Don't allow SKB to be destroyed upon error, but signal resend
* notification to clients. We can't rely on the return value as
* congestion (NET_XMIT_CN) sometimes drops the packet, sometimes don't.
*/
if (netif_queue_stopped(caifd->netdev))
return -EAGAIN;
skb2 = skb_get(skb);
ret = dev_queue_xmit(skb2);
if (!ret)
kfree_skb(skb);
else
return -EAGAIN;
return 0;
}
static int modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
{
struct caif_device_entry *caifd;
struct caif_dev_common *caifdev;
caifd = container_of(layr, struct caif_device_entry, layer);
caifdev = netdev_priv(caifd->netdev);
if (ctrl == _CAIF_MODEMCMD_PHYIF_USEFULL) {
atomic_set(&caifd->in_use, 1);
wake_up_interruptible(&caifd->event);
} else if (ctrl == _CAIF_MODEMCMD_PHYIF_USELESS) {
atomic_set(&caifd->in_use, 0);
wake_up_interruptible(&caifd->event);
}
return 0;
}
/*
* Stuff received packets to associated sockets.
* 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 net *net;
struct cfpkt *pkt;
struct caif_device_entry *caifd;
net = dev_net(dev);
pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
caifd = caif_get(dev);
if (!caifd || !caifd->layer.up || !caifd->layer.up->receive)
return NET_RX_DROP;
if (caifd->layer.up->receive(caifd->layer.up, pkt))
return NET_RX_DROP;
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 = caif_get(dev);
if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
return;
caifd->layer.up->ctrlcmd(caifd->layer.up,
on ?
_CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
_CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
caifd->layer.id);
}
/* 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;
int res = -EINVAL;
enum cfcnfg_phy_type phy_type;
if (dev->type != ARPHRD_CAIF)
return 0;
switch (what) {
case NETDEV_REGISTER:
netdev_info(dev, "register\n");
caifd = caif_device_alloc(dev);
if (caifd == NULL)
break;
caifdev = netdev_priv(dev);
caifdev->flowctrl = dev_flowctrl;
atomic_set(&caifd->state, what);
res = 0;
break;
case NETDEV_UP:
netdev_info(dev, "up\n");
caifd = caif_get(dev);
if (caifd == NULL)
break;
caifdev = netdev_priv(dev);
if (atomic_read(&caifd->state) == NETDEV_UP) {
netdev_info(dev, "already up\n");
break;
}
atomic_set(&caifd->state, what);
caifd->layer.transmit = transmit;
caifd->layer.modemcmd = modemcmd;
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;
}
dev_hold(dev);
cfcnfg_add_phy_layer(get_caif_conf(),
phy_type,
dev,
&caifd->layer,
&caifd->phyid,
pref,
caifdev->use_fcs,
caifdev->use_stx);
strncpy(caifd->layer.name, dev->name,
sizeof(caifd->layer.name) - 1);
caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
break;
case NETDEV_GOING_DOWN:
caifd = caif_get(dev);
if (caifd == NULL)
break;
netdev_info(dev, "going down\n");
if (atomic_read(&caifd->state) == NETDEV_GOING_DOWN ||
atomic_read(&caifd->state) == NETDEV_DOWN)
break;
atomic_set(&caifd->state, what);
if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
return -EINVAL;
caifd->layer.up->ctrlcmd(caifd->layer.up,
_CAIF_CTRLCMD_PHYIF_DOWN_IND,
caifd->layer.id);
might_sleep();
res = wait_event_interruptible_timeout(caifd->event,
atomic_read(&caifd->in_use) == 0,
TIMEOUT);
break;
case NETDEV_DOWN:
caifd = caif_get(dev);
if (caifd == NULL)
break;
netdev_info(dev, "down\n");
if (atomic_read(&caifd->in_use))
netdev_warn(dev,
"Unregistering an active CAIF device\n");
cfcnfg_del_phy_layer(get_caif_conf(), &caifd->layer);
dev_put(dev);
atomic_set(&caifd->state, what);
break;
case NETDEV_UNREGISTER:
caifd = caif_get(dev);
netdev_info(dev, "unregister\n");
atomic_set(&caifd->state, what);
caif_device_destroy(dev);
break;
}
return 0;
}
static struct notifier_block caif_device_notifier = {
.notifier_call = caif_device_notify,
.priority = 0,
};
struct cfcnfg *get_caif_conf(void)
{
return cfg;
}
EXPORT_SYMBOL(get_caif_conf);
int caif_connect_client(struct caif_connect_request *conn_req,
struct cflayer *client_layer, int *ifindex,
int *headroom, int *tailroom)
{
struct cfctrl_link_param param;
int ret;
ret = connect_req_to_link_param(get_caif_conf(), conn_req, &param);
if (ret)
return ret;
/* Hook up the adaptation layer. */
return cfcnfg_add_adaptation_layer(get_caif_conf(), &param,
client_layer, ifindex,
headroom, tailroom);
}
EXPORT_SYMBOL(caif_connect_client);
int caif_disconnect_client(struct cflayer *adap_layer)
{
return cfcnfg_disconn_adapt_layer(get_caif_conf(), adap_layer);
}
EXPORT_SYMBOL(caif_disconnect_client);
void caif_release_client(struct cflayer *adap_layer)
{
cfcnfg_release_adap_layer(adap_layer);
}
EXPORT_SYMBOL(caif_release_client);
/* Per-namespace Caif devices handling */
static int caif_init_net(struct net *net)
{
struct caif_net *caifn = net_generic(net, caif_net_id);
INIT_LIST_HEAD(&caifn->caifdevs.list);
spin_lock_init(&caifn->caifdevs.lock);
return 0;
}
static void caif_exit_net(struct net *net)
{
struct net_device *dev;
int res;
rtnl_lock();
for_each_netdev(net, dev) {
if (dev->type != ARPHRD_CAIF)
continue;
res = dev_close(dev);
caif_device_destroy(dev);
}
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;
cfg = cfcnfg_create();
if (!cfg) {
pr_warn("can't create cfcnfg\n");
goto err_cfcnfg_create_failed;
}
result = register_pernet_device(&caif_net_ops);
if (result) {
kfree(cfg);
cfg = NULL;
return result;
}
dev_add_pack(&caif_packet_type);
register_netdevice_notifier(&caif_device_notifier);
return result;
err_cfcnfg_create_failed:
return -ENODEV;
}
static void __exit caif_device_exit(void)
{
dev_remove_pack(&caif_packet_type);
unregister_pernet_device(&caif_net_ops);
unregister_netdevice_notifier(&caif_device_notifier);
cfcnfg_remove(cfg);
}
module_init(caif_device_init);
module_exit(caif_device_exit);