#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 <linux/mutex.h>
#include <net/netns/generic.h>
#include <net/net_namespace.h>
#include <net/pkt_sched.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;
+ int __percpu *pcpu_refcnt;
};
struct caif_device_entry_list {
struct list_head list;
/* Protects simulanous deletes in list */
- spinlock_t lock;
+ struct mutex lock;
};
struct caif_net {
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;
- list_add(&caifd->list, &caifdevs->list);
- init_waitqueue_head(&caifd->event);
+ dev_hold(dev);
return caifd;
}
caif_device_list(dev_net(dev));
struct caif_device_entry *caifd;
BUG_ON(!caifdevs);
- list_for_each_entry(caifd, &caifdevs->list, list) {
+ list_for_each_entry_rcu(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 =
return 0;
}
-static int modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
-{
- struct caif_device_entry *caifd;
- caifd = container_of(layr, struct caif_device_entry, layer);
- 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.
+ * 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 cfpkt *pkt;
struct caif_device_entry *caifd;
+
pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
+
+ rcu_read_lock();
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))
+ 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();
+ caifd->layer.up->receive(caifd->layer.up, pkt);
+
+ /* Release reference to stack upwards */
+ caifd_put(caifd);
return 0;
}
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)
+ 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 */
struct caif_dev_common *caifdev;
enum cfcnfg_phy_preference pref;
enum cfcnfg_phy_type phy_type;
+ struct caif_device_entry_list *caifdevs =
+ caif_device_list(dev_net(dev));
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;
+ if (!caifd)
+ return 0;
+
caifdev = netdev_priv(dev);
caifdev->flowctrl = dev_flowctrl;
- atomic_set(&caifd->state, what);
- 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;
pref = CFPHYPREF_HIGH_BW;
break;
}
- dev_hold(dev);
+ 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,
- &caifd->phyid,
+ 0,
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;
+ mutex_unlock(&caifdevs->lock);
break;
- case NETDEV_GOING_DOWN:
+ case NETDEV_UP:
+ rcu_read_lock();
+
caifd = caif_get(dev);
- if (caifd == NULL)
+ if (caifd == NULL) {
+ rcu_read_unlock();
break;
- netdev_info(dev, "going down\n");
+ }
- if (atomic_read(&caifd->state) == NETDEV_GOING_DOWN ||
- atomic_read(&caifd->state) == NETDEV_DOWN)
- break;
+ cfcnfg_set_phy_state(cfg, &caifd->layer, true);
+ rcu_read_unlock();
- 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();
- wait_event_interruptible_timeout(caifd->event,
- atomic_read(&caifd->in_use) == 0,
- TIMEOUT);
break;
case NETDEV_DOWN:
+ rcu_read_lock();
+
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(cfg, &caifd->layer);
- dev_put(dev);
- atomic_set(&caifd->state, what);
+ 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)
+ if (caifd == NULL) {
+ mutex_unlock(&caifdevs->lock);
break;
- netdev_info(dev, "unregister\n");
- atomic_set(&caifd->state, what);
- caif_device_destroy(dev);
+ }
+ 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;
};
int caif_connect_client(struct caif_connect_request *conn_req,
- struct cflayer *client_layer, int *ifindex,
- int *headroom, int *tailroom)
+ struct cflayer *client_layer, int *ifindex,
+ int *headroom, int *tailroom)
{
struct cfctrl_link_param param;
int ret;
return ret;
/* Hook up the adaptation layer. */
return cfcnfg_add_adaptation_layer(cfg, ¶m,
- client_layer, ifindex,
- headroom, tailroom);
+ client_layer, ifindex,
+ headroom, tailroom);
}
EXPORT_SYMBOL(caif_connect_client);
{
struct caif_net *caifn = net_generic(net, caif_net_id);
INIT_LIST_HEAD(&caifn->caifdevs.list);
- spin_lock_init(&caifn->caifdevs.lock);
+ mutex_init(&caifn->caifdevs.lock);
return 0;
}
static void caif_exit_net(struct net *net)
{
- struct net_device *dev;
+ struct caif_device_entry *caifd, *tmp;
+ struct caif_device_entry_list *caifdevs =
+ caif_device_list(net);
+
rtnl_lock();
- for_each_netdev(net, dev) {
- if (dev->type != ARPHRD_CAIF)
- continue;
- dev_close(dev);
- caif_device_destroy(dev);
+ mutex_lock(&caifdevs->lock);
+
+ 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);
}
+
+
+ mutex_unlock(&caifdevs->lock);
rtnl_unlock();
}
static int __init caif_device_init(void)
{
int result;
+
cfg = cfcnfg_create();
if (!cfg) {
pr_warn("can't create cfcnfg\n");
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / commitdiff