diff options
| -rw-r--r-- | drivers/net/ntb_netdev.c | 77 | ||||
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 18 | ||||
| -rw-r--r-- | include/linux/ntb_transport.h | 1 |
3 files changed, 95 insertions, 1 deletions
diff --git a/drivers/net/ntb_netdev.c b/drivers/net/ntb_netdev.c index d8757bf9ad75..a9acf7156855 100644 --- a/drivers/net/ntb_netdev.c +++ b/drivers/net/ntb_netdev.c @@ -61,11 +61,21 @@ MODULE_VERSION(NTB_NETDEV_VER); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Intel Corporation"); +/* Time in usecs for tx resource reaper */ +static unsigned int tx_time = 1; + +/* Number of descriptors to free before resuming tx */ +static unsigned int tx_start = 10; + +/* Number of descriptors still available before stop upper layer tx */ +static unsigned int tx_stop = 5; + struct ntb_netdev { struct list_head list; struct pci_dev *pdev; struct net_device *ndev; struct ntb_transport_qp *qp; + struct timer_list tx_timer; }; #define NTB_TX_TIMEOUT_MS 1000 @@ -136,11 +146,42 @@ enqueue_again: } } +static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev, + struct ntb_transport_qp *qp, int size) +{ + struct ntb_netdev *dev = netdev_priv(netdev); + + netif_stop_queue(netdev); + /* Make sure to see the latest value of ntb_transport_tx_free_entry() + * since the queue was last started. + */ + smp_mb(); + + if (likely(ntb_transport_tx_free_entry(qp) < size)) { + mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time)); + return -EBUSY; + } + + netif_start_queue(netdev); + return 0; +} + +static int ntb_netdev_maybe_stop_tx(struct net_device *ndev, + struct ntb_transport_qp *qp, int size) +{ + if (netif_queue_stopped(ndev) || + (ntb_transport_tx_free_entry(qp) >= size)) + return 0; + + return __ntb_netdev_maybe_stop_tx(ndev, qp, size); +} + static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data, void *data, int len) { struct net_device *ndev = qp_data; struct sk_buff *skb; + struct ntb_netdev *dev = netdev_priv(ndev); skb = data; if (!skb || !ndev) @@ -155,6 +196,15 @@ static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data, } dev_kfree_skb(skb); + + if (ntb_transport_tx_free_entry(dev->qp) >= tx_start) { + /* Make sure anybody stopping the queue after this sees the new + * value of ntb_transport_tx_free_entry() + */ + smp_mb(); + if (netif_queue_stopped(ndev)) + netif_wake_queue(ndev); + } } static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb, @@ -163,10 +213,15 @@ static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb, struct ntb_netdev *dev = netdev_priv(ndev); int rc; + ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop); + rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len); if (rc) goto err; + /* check for next submit */ + ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop); + return NETDEV_TX_OK; err: @@ -175,6 +230,23 @@ err: return NETDEV_TX_BUSY; } +static void ntb_netdev_tx_timer(unsigned long data) +{ + struct net_device *ndev = (struct net_device *)data; + struct ntb_netdev *dev = netdev_priv(ndev); + + if (ntb_transport_tx_free_entry(dev->qp) < tx_stop) { + mod_timer(&dev->tx_timer, jiffies + msecs_to_jiffies(tx_time)); + } else { + /* Make sure anybody stopping the queue after this sees the new + * value of ntb_transport_tx_free_entry() + */ + smp_mb(); + if (netif_queue_stopped(ndev)) + netif_wake_queue(ndev); + } +} + static int ntb_netdev_open(struct net_device *ndev) { struct ntb_netdev *dev = netdev_priv(ndev); @@ -197,8 +269,11 @@ static int ntb_netdev_open(struct net_device *ndev) } } + setup_timer(&dev->tx_timer, ntb_netdev_tx_timer, (unsigned long)ndev); + netif_carrier_off(ndev); ntb_transport_link_up(dev->qp); + netif_start_queue(ndev); return 0; @@ -219,6 +294,8 @@ static int ntb_netdev_close(struct net_device *ndev) while ((skb = ntb_transport_rx_remove(dev->qp, &len))) dev_kfree_skb(skb); + del_timer_sync(&dev->tx_timer); + return 0; } diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 1c6386d5f79c..0d851d684523 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -494,6 +494,12 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count, "tx_index - \t%u\n", qp->tx_index); out_offset += snprintf(buf + out_offset, out_count - out_offset, "tx_max_entry - \t%u\n", qp->tx_max_entry); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "qp->remote_rx_info->entry - \t%u\n", + qp->remote_rx_info->entry); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "free tx - \t%u\n", + ntb_transport_tx_free_entry(qp)); out_offset += snprintf(buf + out_offset, out_count - out_offset, "\nQP Link %s\n", @@ -535,6 +541,7 @@ static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock, } entry = list_first_entry(list, struct ntb_queue_entry, entry); list_del(&entry->entry); + out: spin_unlock_irqrestore(lock, flags); @@ -1843,7 +1850,7 @@ int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); if (!entry) { qp->tx_err_no_buf++; - return -ENOMEM; + return -EBUSY; } entry->cb_data = cb; @@ -1969,6 +1976,15 @@ unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp) } EXPORT_SYMBOL_GPL(ntb_transport_max_size); +unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp) +{ + unsigned int head = qp->tx_index; + unsigned int tail = qp->remote_rx_info->entry; + + return tail > head ? tail - head : qp->tx_max_entry + tail - head; +} +EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry); + static void ntb_transport_doorbell_callback(void *data, int vector) { struct ntb_transport_ctx *nt = data; diff --git a/include/linux/ntb_transport.h b/include/linux/ntb_transport.h index 2862861366a5..7243eb98a722 100644 --- a/include/linux/ntb_transport.h +++ b/include/linux/ntb_transport.h @@ -83,3 +83,4 @@ void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len); void ntb_transport_link_up(struct ntb_transport_qp *qp); void ntb_transport_link_down(struct ntb_transport_qp *qp); bool ntb_transport_link_query(struct ntb_transport_qp *qp); +unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp); |