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ntb_netdev.c
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ntb_netdev.c
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/*
* 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 <[email protected]>
*/
#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(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(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);
strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
strlcpy(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;
return ntb_transport_register_client(&ntb_netdev_client);
}
module_init(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);