Fri, Jul 13, 2012 at 11:45:00PM CEST, [email protected] wrote:
>A virtual ethernet device that uses the NTB transport API to send/receive data.
>
>Signed-off-by: Jon Mason <[email protected]>
>---
> 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 <[email protected]>
>+ */
>+#include <linux/etherdevice.h>
>+#include <linux/ethtool.h>
>+#include <linux/module.h>
>+#include <linux/ntb.h>
>+
>+#define NTB_NETDEV_VER        "0.4"

Is it really necessary to provide this in-file versioning? Doesn't
kernel version itself do the trick?

>+
>+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");

Would be maybe better to use netdev_err here (and on similar other
places)

Also, it might be good to provide rollback in case any of
netdev_alloc_skb() fails.

>+      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,

Does your device support mac change while it's up and running?

>+};
>+
>+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));

I might be missing something but this place (module init) does not seems
like a good place to do alloc_etherdev(). Do you want to support only
one netdevice instance?

Anyway, I think that using "static netdev" should be avoided in any case.


>+      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
>
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