#include <linux/netdevice.h>
#include <linux/mutex.h>
#include <linux/module.h>
+#include <linux/spinlock.h>
#include <net/netns/generic.h>
#include <net/net_namespace.h>
#include <net/pkt_sched.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfcnfg.h>
+#include <net/caif/cfserl.h>
MODULE_LICENSE("GPL");
struct list_head list;
struct net_device *netdev;
int __percpu *pcpu_refcnt;
+ spinlock_t flow_lock;
+ struct sk_buff *xoff_skb;
+ void (*xoff_skb_dtor)(struct sk_buff *skb);
+ bool xoff;
};
struct caif_device_entry_list {
};
static int caif_net_id;
+static int q_high = 50; /* Percent */
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);
+ this_cpu_dec(*e->pcpu_refcnt);
}
static void caifd_hold(struct caif_device_entry *e)
{
- irqsafe_cpu_inc(*e->pcpu_refcnt);
+ this_cpu_inc(*e->pcpu_refcnt);
}
static int caifd_refcnt_read(struct caif_device_entry *e)
struct caif_device_entry *caifd;
caifdevs = caif_device_list(dev_net(dev));
- BUG_ON(!caifdevs);
caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
if (!caifd)
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;
}
+void caif_flow_cb(struct sk_buff *skb)
+{
+ struct caif_device_entry *caifd;
+ void (*dtor)(struct sk_buff *skb) = NULL;
+ bool send_xoff;
+
+ WARN_ON(skb->dev == NULL);
+
+ rcu_read_lock();
+ caifd = caif_get(skb->dev);
+ caifd_hold(caifd);
+ rcu_read_unlock();
+
+ spin_lock_bh(&caifd->flow_lock);
+ send_xoff = caifd->xoff;
+ caifd->xoff = 0;
+ dtor = caifd->xoff_skb_dtor;
+
+ if (WARN_ON(caifd->xoff_skb != skb))
+ skb = NULL;
+
+ caifd->xoff_skb = NULL;
+ caifd->xoff_skb_dtor = NULL;
+
+ spin_unlock_bh(&caifd->flow_lock);
+
+ if (dtor && skb)
+ dtor(skb);
+
+ if (send_xoff)
+ caifd->layer.up->
+ ctrlcmd(caifd->layer.up,
+ _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND,
+ caifd->layer.id);
+ caifd_put(caifd);
+}
+
static int transmit(struct cflayer *layer, struct cfpkt *pkt)
{
- int err;
+ int err, high = 0, qlen = 0;
+ struct caif_dev_common *caifdev;
struct caif_device_entry *caifd =
container_of(layer, struct caif_device_entry, layer);
struct sk_buff *skb;
+ struct netdev_queue *txq;
+
+ rcu_read_lock_bh();
skb = cfpkt_tonative(pkt);
skb->dev = caifd->netdev;
+ skb_reset_network_header(skb);
+ skb->protocol = htons(ETH_P_CAIF);
+ caifdev = netdev_priv(caifd->netdev);
+
+ /* Check if we need to handle xoff */
+ if (likely(caifd->netdev->tx_queue_len == 0))
+ goto noxoff;
+
+ if (unlikely(caifd->xoff))
+ goto noxoff;
+
+ if (likely(!netif_queue_stopped(caifd->netdev))) {
+ /* If we run with a TX queue, check if the queue is too long*/
+ txq = netdev_get_tx_queue(skb->dev, 0);
+ qlen = qdisc_qlen(rcu_dereference_bh(txq->qdisc));
+
+ if (likely(qlen == 0))
+ goto noxoff;
+
+ high = (caifd->netdev->tx_queue_len * q_high) / 100;
+ if (likely(qlen < high))
+ goto noxoff;
+ }
+
+ /* Hold lock while accessing xoff */
+ spin_lock_bh(&caifd->flow_lock);
+ if (caifd->xoff) {
+ spin_unlock_bh(&caifd->flow_lock);
+ goto noxoff;
+ }
+
+ /*
+ * Handle flow off, we do this by temporary hi-jacking this
+ * skb's destructor function, and replace it with our own
+ * flow-on callback. The callback will set flow-on and call
+ * the original destructor.
+ */
+
+ pr_debug("queue has stopped(%d) or is full (%d > %d)\n",
+ netif_queue_stopped(caifd->netdev),
+ qlen, high);
+ caifd->xoff = 1;
+ caifd->xoff_skb = skb;
+ caifd->xoff_skb_dtor = skb->destructor;
+ skb->destructor = caif_flow_cb;
+ spin_unlock_bh(&caifd->flow_lock);
+
+ caifd->layer.up->ctrlcmd(caifd->layer.up,
+ _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+ caifd->layer.id);
+noxoff:
+ rcu_read_unlock_bh();
err = dev_queue_xmit(skb);
if (err > 0)
/* Release reference to stack upwards */
caifd_put(caifd);
- return 0;
+
+ if (err != 0)
+ err = NET_RX_DROP;
+ return err;
}
static struct packet_type caif_packet_type __read_mostly = {
caifd_put(caifd);
}
+void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+ struct cflayer *link_support, int head_room,
+ struct cflayer **layer, int (**rcv_func)(
+ struct sk_buff *, struct net_device *,
+ struct packet_type *, struct net_device *))
+{
+ struct caif_device_entry *caifd;
+ enum cfcnfg_phy_preference pref;
+ struct cfcnfg *cfg = get_cfcnfg(dev_net(dev));
+ struct caif_device_entry_list *caifdevs;
+
+ caifdevs = caif_device_list(dev_net(dev));
+ caifd = caif_device_alloc(dev);
+ if (!caifd)
+ return;
+ *layer = &caifd->layer;
+ spin_lock_init(&caifd->flow_lock);
+
+ 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;
+ }
+ mutex_lock(&caifdevs->lock);
+ list_add_rcu(&caifd->list, &caifdevs->list);
+
+ strncpy(caifd->layer.name, dev->name,
+ sizeof(caifd->layer.name) - 1);
+ caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
+ caifd->layer.transmit = transmit;
+ cfcnfg_add_phy_layer(cfg,
+ dev,
+ &caifd->layer,
+ pref,
+ link_support,
+ caifdev->use_fcs,
+ head_room);
+ mutex_unlock(&caifdevs->lock);
+ if (rcv_func)
+ *rcv_func = receive;
+}
+EXPORT_SYMBOL(caif_enroll_dev);
+
/* 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 cflayer *layer, *link_support;
+ int head_room = 0;
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));
+ caifd = caif_get(dev);
+ if (caifd == NULL && dev->type != ARPHRD_CAIF)
+ return 0;
+
switch (what) {
case NETDEV_REGISTER:
- caifd = caif_device_alloc(dev);
- if (!caifd)
- return 0;
+ if (caifd != NULL)
+ break;
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;
+ link_support = NULL;
+ if (caifdev->use_frag) {
+ head_room = 1;
+ link_support = cfserl_create(dev->ifindex,
+ caifdev->use_stx);
+ if (!link_support) {
+ pr_warn("Out of memory\n");
+ 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);
+ caif_enroll_dev(dev, caifdev, link_support, head_room,
+ &layer, NULL);
+ caifdev->flowctrl = dev_flowctrl;
break;
case NETDEV_UP:
break;
}
+ caifd->xoff = 0;
cfcnfg_set_phy_state(cfg, &caifd->layer, true);
rcu_read_unlock();
caifd->layer.up->ctrlcmd(caifd->layer.up,
_CAIF_CTRLCMD_PHYIF_DOWN_IND,
caifd->layer.id);
+
+ spin_lock_bh(&caifd->flow_lock);
+
+ /*
+ * Replace our xoff-destructor with original destructor.
+ * We trust that skb->destructor *always* is called before
+ * the skb reference is invalid. The hijacked SKB destructor
+ * takes the flow_lock so manipulating the skb->destructor here
+ * should be safe.
+ */
+ if (caifd->xoff_skb_dtor != NULL && caifd->xoff_skb != NULL)
+ caifd->xoff_skb->destructor = caifd->xoff_skb_dtor;
+
+ caifd->xoff = 0;
+ caifd->xoff_skb_dtor = NULL;
+ caifd->xoff_skb = NULL;
+
+ spin_unlock_bh(&caifd->flow_lock);
caifd_put(caifd);
break;
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");
+ if (!caifn->cfg)
return -ENOMEM;
- }
return 0;
}
struct caif_device_entry *caifd, *tmp;
struct caif_device_entry_list *caifdevs =
caif_device_list(net);
- struct cfcnfg *cfg;
+ struct cfcnfg *cfg = get_cfcnfg(net);
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);
{
int result;
- result = register_pernet_device(&caif_net_ops);
+ result = register_pernet_subsys(&caif_net_ops);
if (result)
return result;
static void __exit caif_device_exit(void)
{
- unregister_pernet_device(&caif_net_ops);
+ unregister_pernet_subsys(&caif_net_ops);
unregister_netdevice_notifier(&caif_device_notifier);
dev_remove_pack(&caif_packet_type);
}
projects / cascardo / linux.git / blobdiff