diff options
| -rw-r--r-- | net/caif/caif_dev.c | 85 |
1 files changed, 84 insertions, 1 deletions
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c index 6acec19..74c1273 100644 --- a/net/caif/caif_dev.c +++ b/net/caif/caif_dev.c @@ -17,6 +17,7 @@ #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> @@ -34,6 +35,8 @@ struct caif_device_entry { struct list_head list; struct net_device *netdev; int __percpu *pcpu_refcnt; + spinlock_t flow_lock; + bool xoff; }; struct caif_device_entry_list { @@ -48,6 +51,7 @@ struct caif_net { }; static int caif_net_id; +static int q_high = 50; /* Percent */ struct cfcnfg *get_cfcnfg(struct net *net) { @@ -126,17 +130,94 @@ static struct caif_device_entry *caif_get(struct net_device *dev) return NULL; } +void caif_flow_cb(struct sk_buff *skb) +{ + struct caif_device_entry *caifd; + 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; + spin_unlock_bh(&caifd->flow_lock); + + 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; + spin_unlock_bh(&caifd->flow_lock); + skb_orphan(skb); + + 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) @@ -232,6 +313,7 @@ void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev, if (!caifd) return; *layer = &caifd->layer; + spin_lock_init(&caifd->flow_lock); switch (caifdev->link_select) { case CAIF_LINK_HIGH_BANDW: @@ -316,6 +398,7 @@ static int caif_device_notify(struct notifier_block *me, unsigned long what, break; } + caifd->xoff = 0; cfcnfg_set_phy_state(cfg, &caifd->layer, true); rcu_read_unlock(); |
