[RFC 2/2] net: Add support for NTB virtual ethernet device
From: Jon Mason
Date: Fri Jul 13 2012 - 17:45:36 EST
A virtual ethernet device that uses the NTB transport API to send/receive data.
Signed-off-by: Jon Mason <jon.mason@xxxxxxxxx>
---
drivers/net/Kconfig | 4 +
drivers/net/Makefile | 1 +
drivers/net/ntb_netdev.c | 411 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 416 insertions(+), 0 deletions(-)
create mode 100644 drivers/net/ntb_netdev.c
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 0c2bd80..9bf8a71 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -178,6 +178,10 @@ config NETPOLL_TRAP
config NET_POLL_CONTROLLER
def_bool NETPOLL
+config NTB_NETDEV
+ tristate "Virtual Ethernet over NTB"
+ depends on NTB
+
config RIONET
tristate "RapidIO Ethernet over messaging driver support"
depends on RAPIDIO
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 3d375ca..9890148 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -69,3 +69,4 @@ obj-$(CONFIG_USB_IPHETH) += usb/
obj-$(CONFIG_USB_CDC_PHONET) += usb/
obj-$(CONFIG_HYPERV_NET) += hyperv/
+obj-$(CONFIG_NTB_NETDEV) += ntb_netdev.o
diff --git a/drivers/net/ntb_netdev.c b/drivers/net/ntb_netdev.c
new file mode 100644
index 0000000..bcbd9d4
--- /dev/null
+++ b/drivers/net/ntb_netdev.c
@@ -0,0 +1,411 @@
+/*
+ * 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.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ * The full GNU General Public License is included in this distribution
+ * in the file called LICENSE.GPL.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2012 Intel 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.
+ *
+ * Intel PCIe NTB Network Linux driver
+ *
+ * Contact Information:
+ * Jon Mason <jon.mason@xxxxxxxxx>
+ */
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/module.h>
+#include <linux/ntb.h>
+
+#define NTB_NETDEV_VER "0.4"
+
+MODULE_DESCRIPTION(KBUILD_MODNAME);
+MODULE_VERSION(NTB_NETDEV_VER);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Intel Corporation");
+
+struct ntb_netdev {
+ struct net_device *ndev;
+ struct ntb_transport_qp *qp;
+};
+
+#define NTB_TX_TIMEOUT_MS 1000
+#define NTB_RXQ_SIZE 100
+
+static struct net_device *netdev;
+
+static void ntb_netdev_event_handler(int status)
+{
+ struct ntb_netdev *dev = netdev_priv(netdev);
+
+ pr_debug("%s: Event %x, Link %x\n", KBUILD_MODNAME, status,
+ ntb_transport_link_query(dev->qp));
+
+ /* Currently, only link status event is supported */
+ if (status)
+ netif_carrier_on(netdev);
+ else
+ netif_carrier_off(netdev);
+}
+
+static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp)
+{
+ struct net_device *ndev = netdev;
+ struct sk_buff *skb;
+ int len, rc;
+
+ while ((skb = ntb_transport_rx_dequeue(qp, &len))) {
+ pr_debug("%s: %d byte payload received\n", __func__, len);
+
+ 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++;
+ pr_err("%s: No skb\n", __func__);
+ break;
+ }
+
+ rc = ntb_transport_rx_enqueue(qp, skb, skb->data,
+ ndev->mtu + ETH_HLEN);
+ if (rc) {
+ ndev->stats.rx_errors++;
+ ndev->stats.rx_fifo_errors++;
+ pr_err("%s: error re-enqueuing\n", __func__);
+ break;
+ }
+ }
+}
+
+static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp)
+{
+ struct net_device *ndev = netdev;
+ struct sk_buff *skb;
+ int len;
+
+ while ((skb = ntb_transport_tx_dequeue(qp, &len))) {
+ ndev->stats.tx_packets++;
+ ndev->stats.tx_bytes += skb->len;
+ dev_kfree_skb(skb);
+ }
+
+ 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;
+
+ pr_debug("%s: ntb_transport_tx_enqueue\n", KBUILD_MODNAME);
+
+ rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len);
+ if (rc)
+ goto err;
+
+ return NETDEV_TX_OK;
+
+err:
+ ndev->stats.tx_dropped++;
+ ndev->stats.tx_errors++;
+ netif_stop_queue(ndev);
+ return NETDEV_TX_BUSY;
+}
+
+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 == -EINVAL)
+ goto err;
+ }
+
+ netif_carrier_off(ndev);
+ ntb_transport_link_up(dev->qp);
+
+ return 0;
+
+err:
+ while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
+ kfree(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)))
+ kfree(skb);
+
+ 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++)
+ kfree(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) {
+ kfree(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)))
+ kfree(skb);
+
+ pr_err("Error changing MTU, device inoperable\n");
+ return rc;
+}
+
+static void ntb_netdev_tx_timeout(struct net_device *ndev)
+{
+ if (netif_running(ndev))
+ netif_wake_queue(ndev);
+}
+
+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_tx_timeout = ntb_netdev_tx_timeout,
+ .ndo_set_mac_address = eth_mac_addr,
+};
+
+static void ntb_get_drvinfo(__attribute__((unused)) struct net_device *dev,
+ struct ethtool_drvinfo *info)
+{
+ strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
+ strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
+}
+
+static const char ntb_nic_stats[][ETH_GSTRING_LEN] = {
+ "rx_packets", "rx_bytes", "rx_errors", "rx_dropped", "rx_length_errors",
+ "rx_frame_errors", "rx_fifo_errors",
+ "tx_packets", "tx_bytes", "tx_errors", "tx_dropped",
+};
+
+static int ntb_get_stats_count(__attribute__((unused)) struct net_device *dev)
+{
+ return ARRAY_SIZE(ntb_nic_stats);
+}
+
+static int ntb_get_sset_count(struct net_device *dev, int sset)
+{
+ switch (sset) {
+ case ETH_SS_STATS:
+ return ntb_get_stats_count(dev);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static void ntb_get_strings(__attribute__((unused)) struct net_device *dev,
+ u32 sset, u8 *data)
+{
+ switch (sset) {
+ case ETH_SS_STATS:
+ memcpy(data, *ntb_nic_stats, sizeof(ntb_nic_stats));
+ }
+}
+
+static void
+ntb_get_ethtool_stats(struct net_device *dev,
+ __attribute__((unused)) struct ethtool_stats *stats,
+ u64 *data)
+{
+ int i = 0;
+
+ data[i++] = dev->stats.rx_packets;
+ data[i++] = dev->stats.rx_bytes;
+ data[i++] = dev->stats.rx_errors;
+ data[i++] = dev->stats.rx_dropped;
+ data[i++] = dev->stats.rx_length_errors;
+ data[i++] = dev->stats.rx_frame_errors;
+ data[i++] = dev->stats.rx_fifo_errors;
+ data[i++] = dev->stats.tx_packets;
+ data[i++] = dev->stats.tx_bytes;
+ data[i++] = dev->stats.tx_errors;
+ data[i++] = dev->stats.tx_dropped;
+}
+
+static const struct ethtool_ops ntb_ethtool_ops = {
+ .get_drvinfo = ntb_get_drvinfo,
+ .get_sset_count = ntb_get_sset_count,
+ .get_strings = ntb_get_strings,
+ .get_ethtool_stats = ntb_get_ethtool_stats,
+ .get_link = ethtool_op_get_link,
+};
+
+static int __init ntb_netdev_init_module(void)
+{
+ struct ntb_netdev *dev;
+ int rc;
+
+ pr_info("%s: Probe\n", KBUILD_MODNAME);
+
+ netdev = alloc_etherdev(sizeof(struct ntb_netdev));
+ if (!netdev)
+ return -ENOMEM;
+
+ dev = netdev_priv(netdev);
+ dev->ndev = netdev;
+ netdev->features = NETIF_F_HIGHDMA;
+
+ netdev->hw_features = netdev->features;
+ netdev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS);
+
+ random_ether_addr(netdev->perm_addr);
+ memcpy(netdev->dev_addr, netdev->perm_addr, netdev->addr_len);
+
+ netdev->netdev_ops = &ntb_netdev_ops;
+ SET_ETHTOOL_OPS(netdev, &ntb_ethtool_ops);
+
+ dev->qp = ntb_transport_create_queue(ntb_netdev_rx_handler,
+ ntb_netdev_tx_handler,
+ ntb_netdev_event_handler);
+ if (!dev->qp) {
+ rc = -EIO;
+ goto err;
+ }
+
+ netdev->mtu = ntb_transport_max_size(dev->qp) - ETH_HLEN;
+
+ rc = register_netdev(netdev);
+ if (rc)
+ goto err1;
+
+ pr_info("%s: %s created\n", KBUILD_MODNAME, netdev->name);
+ return 0;
+
+err1:
+ ntb_transport_free_queue(dev->qp);
+err:
+ free_netdev(netdev);
+ return rc;
+}
+module_init(ntb_netdev_init_module);
+
+static void __exit ntb_netdev_exit_module(void)
+{
+ struct ntb_netdev *dev = netdev_priv(netdev);
+
+ unregister_netdev(netdev);
+ ntb_transport_free_queue(dev->qp);
+ free_netdev(netdev);
+
+ pr_info("%s: Driver removed\n", KBUILD_MODNAME);
+}
+module_exit(ntb_netdev_exit_module);
--
1.7.5.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/