diff options
Diffstat (limited to 'drivers/net/ntb_netdev.c')
| -rw-r--r-- | drivers/net/ntb_netdev.c | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/drivers/net/ntb_netdev.c b/drivers/net/ntb_netdev.c new file mode 100644 index 000000000..536bd6564 --- /dev/null +++ b/drivers/net/ntb_netdev.c @@ -0,0 +1,503 @@ +/* + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2012 Intel Corporation. All rights reserved. + * Copyright (C) 2015 EMC Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * BSD LICENSE + * + * Copyright(c) 2012 Intel Corporation. All rights reserved. + * Copyright (C) 2015 EMC Corporation. All Rights Reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copy + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * PCIe NTB Network Linux driver + * + * Contact Information: + * Jon Mason <jon.mason@intel.com> + */ +#include <linux/etherdevice.h> +#include <linux/ethtool.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/ntb.h> +#include <linux/ntb_transport.h> + +#define NTB_NETDEV_VER "0.7" + +MODULE_DESCRIPTION(KBUILD_MODNAME); +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 pci_dev *pdev; + struct net_device *ndev; + struct ntb_transport_qp *qp; + struct timer_list tx_timer; +}; + +#define NTB_TX_TIMEOUT_MS 1000 +#define NTB_RXQ_SIZE 100 + +static void ntb_netdev_event_handler(void *data, int link_is_up) +{ + struct net_device *ndev = data; + struct ntb_netdev *dev = netdev_priv(ndev); + + netdev_dbg(ndev, "Event %x, Link %x\n", link_is_up, + ntb_transport_link_query(dev->qp)); + + if (link_is_up) { + if (ntb_transport_link_query(dev->qp)) + netif_carrier_on(ndev); + } else { + netif_carrier_off(ndev); + } +} + +static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data, + void *data, int len) +{ + struct net_device *ndev = qp_data; + struct sk_buff *skb; + int rc; + + skb = data; + if (!skb) + return; + + netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len); + + if (len < 0) { + ndev->stats.rx_errors++; + ndev->stats.rx_length_errors++; + goto enqueue_again; + } + + skb_put(skb, len); + skb->protocol = eth_type_trans(skb, ndev); + skb->ip_summed = CHECKSUM_NONE; + + if (__netif_rx(skb) == NET_RX_DROP) { + ndev->stats.rx_errors++; + ndev->stats.rx_dropped++; + } else { + ndev->stats.rx_packets++; + ndev->stats.rx_bytes += len; + } + + skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN); + if (!skb) { + ndev->stats.rx_errors++; + ndev->stats.rx_frame_errors++; + return; + } + +enqueue_again: + rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN); + if (rc) { + dev_kfree_skb_any(skb); + ndev->stats.rx_errors++; + ndev->stats.rx_fifo_errors++; + } +} + +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) + return; + + if (len > 0) { + ndev->stats.tx_packets++; + ndev->stats.tx_bytes += skb->len; + } else { + ndev->stats.tx_errors++; + ndev->stats.tx_aborted_errors++; + } + + dev_kfree_skb_any(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, + struct net_device *ndev) +{ + 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: + ndev->stats.tx_dropped++; + ndev->stats.tx_errors++; + return NETDEV_TX_BUSY; +} + +static void ntb_netdev_tx_timer(struct timer_list *t) +{ + struct ntb_netdev *dev = from_timer(dev, t, tx_timer); + struct net_device *ndev = dev->ndev; + + if (ntb_transport_tx_free_entry(dev->qp) < tx_stop) { + mod_timer(&dev->tx_timer, jiffies + usecs_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); + struct sk_buff *skb; + int rc, i, len; + + /* Add some empty rx bufs */ + for (i = 0; i < NTB_RXQ_SIZE; i++) { + skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN); + if (!skb) { + rc = -ENOMEM; + goto err; + } + + rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data, + ndev->mtu + ETH_HLEN); + if (rc) { + dev_kfree_skb(skb); + goto err; + } + } + + timer_setup(&dev->tx_timer, ntb_netdev_tx_timer, 0); + + netif_carrier_off(ndev); + ntb_transport_link_up(dev->qp); + netif_start_queue(ndev); + + return 0; + +err: + while ((skb = ntb_transport_rx_remove(dev->qp, &len))) + dev_kfree_skb(skb); + return rc; +} + +static int ntb_netdev_close(struct net_device *ndev) +{ + struct ntb_netdev *dev = netdev_priv(ndev); + struct sk_buff *skb; + int len; + + ntb_transport_link_down(dev->qp); + + while ((skb = ntb_transport_rx_remove(dev->qp, &len))) + dev_kfree_skb(skb); + + del_timer_sync(&dev->tx_timer); + + return 0; +} + +static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu) +{ + struct ntb_netdev *dev = netdev_priv(ndev); + struct sk_buff *skb; + int len, rc; + + if (new_mtu > ntb_transport_max_size(dev->qp) - ETH_HLEN) + return -EINVAL; + + if (!netif_running(ndev)) { + ndev->mtu = new_mtu; + return 0; + } + + /* Bring down the link and dispose of posted rx entries */ + ntb_transport_link_down(dev->qp); + + if (ndev->mtu < new_mtu) { + int i; + + for (i = 0; (skb = ntb_transport_rx_remove(dev->qp, &len)); i++) + dev_kfree_skb(skb); + + for (; i; i--) { + skb = netdev_alloc_skb(ndev, new_mtu + ETH_HLEN); + if (!skb) { + rc = -ENOMEM; + goto err; + } + + rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data, + new_mtu + ETH_HLEN); + if (rc) { + dev_kfree_skb(skb); + goto err; + } + } + } + + ndev->mtu = new_mtu; + + ntb_transport_link_up(dev->qp); + + return 0; + +err: + ntb_transport_link_down(dev->qp); + + while ((skb = ntb_transport_rx_remove(dev->qp, &len))) + dev_kfree_skb(skb); + + netdev_err(ndev, "Error changing MTU, device inoperable\n"); + return rc; +} + +static const struct net_device_ops ntb_netdev_ops = { + .ndo_open = ntb_netdev_open, + .ndo_stop = ntb_netdev_close, + .ndo_start_xmit = ntb_netdev_start_xmit, + .ndo_change_mtu = ntb_netdev_change_mtu, + .ndo_set_mac_address = eth_mac_addr, +}; + +static void ntb_get_drvinfo(struct net_device *ndev, + struct ethtool_drvinfo *info) +{ + struct ntb_netdev *dev = netdev_priv(ndev); + + strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver)); + strscpy(info->version, NTB_NETDEV_VER, sizeof(info->version)); + strscpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info)); +} + +static int ntb_get_link_ksettings(struct net_device *dev, + struct ethtool_link_ksettings *cmd) +{ + ethtool_link_ksettings_zero_link_mode(cmd, supported); + ethtool_link_ksettings_add_link_mode(cmd, supported, Backplane); + ethtool_link_ksettings_zero_link_mode(cmd, advertising); + ethtool_link_ksettings_add_link_mode(cmd, advertising, Backplane); + + cmd->base.speed = SPEED_UNKNOWN; + cmd->base.duplex = DUPLEX_FULL; + cmd->base.port = PORT_OTHER; + cmd->base.phy_address = 0; + cmd->base.autoneg = AUTONEG_ENABLE; + + return 0; +} + +static const struct ethtool_ops ntb_ethtool_ops = { + .get_drvinfo = ntb_get_drvinfo, + .get_link = ethtool_op_get_link, + .get_link_ksettings = ntb_get_link_ksettings, +}; + +static const struct ntb_queue_handlers ntb_netdev_handlers = { + .tx_handler = ntb_netdev_tx_handler, + .rx_handler = ntb_netdev_rx_handler, + .event_handler = ntb_netdev_event_handler, +}; + +static int ntb_netdev_probe(struct device *client_dev) +{ + struct ntb_dev *ntb; + struct net_device *ndev; + struct pci_dev *pdev; + struct ntb_netdev *dev; + int rc; + + ntb = dev_ntb(client_dev->parent); + pdev = ntb->pdev; + if (!pdev) + return -ENODEV; + + ndev = alloc_etherdev(sizeof(*dev)); + if (!ndev) + return -ENOMEM; + + SET_NETDEV_DEV(ndev, client_dev); + + dev = netdev_priv(ndev); + dev->ndev = ndev; + dev->pdev = pdev; + ndev->features = NETIF_F_HIGHDMA; + + ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + + ndev->hw_features = ndev->features; + ndev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS); + + eth_random_addr(ndev->perm_addr); + dev_addr_set(ndev, ndev->perm_addr); + + ndev->netdev_ops = &ntb_netdev_ops; + ndev->ethtool_ops = &ntb_ethtool_ops; + + ndev->min_mtu = 0; + ndev->max_mtu = ETH_MAX_MTU; + + dev->qp = ntb_transport_create_queue(ndev, client_dev, + &ntb_netdev_handlers); + if (!dev->qp) { + rc = -EIO; + goto err; + } + + ndev->mtu = ntb_transport_max_size(dev->qp) - ETH_HLEN; + + rc = register_netdev(ndev); + if (rc) + goto err1; + + dev_set_drvdata(client_dev, ndev); + dev_info(&pdev->dev, "%s created\n", ndev->name); + return 0; + +err1: + ntb_transport_free_queue(dev->qp); +err: + free_netdev(ndev); + return rc; +} + +static void ntb_netdev_remove(struct device *client_dev) +{ + struct net_device *ndev = dev_get_drvdata(client_dev); + struct ntb_netdev *dev = netdev_priv(ndev); + + unregister_netdev(ndev); + ntb_transport_free_queue(dev->qp); + free_netdev(ndev); +} + +static struct ntb_transport_client ntb_netdev_client = { + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .probe = ntb_netdev_probe, + .remove = ntb_netdev_remove, +}; + +static int __init ntb_netdev_init_module(void) +{ + int rc; + + rc = ntb_transport_register_client_dev(KBUILD_MODNAME); + if (rc) + return rc; + + rc = ntb_transport_register_client(&ntb_netdev_client); + if (rc) { + ntb_transport_unregister_client_dev(KBUILD_MODNAME); + return rc; + } + + return 0; +} +late_initcall(ntb_netdev_init_module); + +static void __exit ntb_netdev_exit_module(void) +{ + ntb_transport_unregister_client(&ntb_netdev_client); + ntb_transport_unregister_client_dev(KBUILD_MODNAME); +} +module_exit(ntb_netdev_exit_module); |