net: Add support for NTB virtual ethernet device

A virtual ethernet device that uses the NTB transport API to
send/receive data.

Signed-off-by: Jon Mason <jon.mason@intel.com>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 419 insertions, 0 deletions

diff --git a/drivers/net/ntb_netdev.c b/drivers/net/ntb_netdev.c
new file mode 100644
index 000000000000..af48a69cab02
--- /dev/null
+++ b/drivers/net/ntb_netdev.c
@@ -0,0 +1,419 @@
+/*
+ * 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.
+ *
+ *   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@intel.com>
+ */
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/ntb.h>
+
+#define NTB_NETDEV_VER  "0.6"
+
+MODULE_DESCRIPTION(KBUILD_MODNAME);
+MODULE_VERSION(NTB_NETDEV_VER);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Intel Corporation");
+
+struct ntb_netdev {
+        struct list_head list;
+        struct pci_dev *pdev;
+        struct net_device *ndev;
+        struct ntb_transport_qp *qp;
+};
+
+#define NTB_TX_TIMEOUT_MS       1000
+#define NTB_RXQ_SIZE            100
+
+static LIST_HEAD(dev_list);
+
+static void ntb_netdev_event_handler(void *data, int status)
+{
+        struct net_device *ndev = data;
+        struct ntb_netdev *dev = netdev_priv(ndev);
+
+        netdev_dbg(ndev, "Event %x, Link %x\n", status,
+                   ntb_transport_link_query(dev->qp));
+
+        /* Currently, only link status event is supported */
+        if (status)
+                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);
+
+        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;
+        }
+
+        rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
+        if (rc) {
+                ndev->stats.rx_errors++;
+                ndev->stats.rx_fifo_errors++;
+        }
+}
+
+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;
+
+        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 (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;
+
+        netdev_dbg(ndev, "ntb_transport_tx_enqueue\n");
+
+        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)))
+                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);
+
+        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 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(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_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+        cmd->supported = SUPPORTED_Backplane;
+        cmd->advertising = ADVERTISED_Backplane;
+        cmd->speed = SPEED_UNKNOWN;
+        ethtool_cmd_speed_set(cmd, SPEED_UNKNOWN);
+        cmd->duplex = DUPLEX_FULL;
+        cmd->port = PORT_OTHER;
+        cmd->phy_address = 0;
+        cmd->transceiver = XCVR_DUMMY1;
+        cmd->autoneg = AUTONEG_ENABLE;
+        cmd->maxtxpkt = 0;
+        cmd->maxrxpkt = 0;
+
+        return 0;
+}
+
+static const struct ethtool_ops ntb_ethtool_ops = {
+        .get_drvinfo = ntb_get_drvinfo,
+        .get_link = ethtool_op_get_link,
+        .get_settings = ntb_get_settings,
+};
+
+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 __devinit ntb_netdev_probe(struct pci_dev *pdev)
+{
+        struct net_device *ndev;
+        struct ntb_netdev *dev;
+        int rc;
+
+        ndev = alloc_etherdev(sizeof(struct ntb_netdev));
+        if (!ndev)
+                return -ENOMEM;
+
+        dev = netdev_priv(ndev);
+        dev->ndev = ndev;
+        dev->pdev = pdev;
+        BUG_ON(!dev->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);
+
+        random_ether_addr(ndev->perm_addr);
+        memcpy(ndev->dev_addr, ndev->perm_addr, ndev->addr_len);
+
+        ndev->netdev_ops = &ntb_netdev_ops;
+        SET_ETHTOOL_OPS(ndev, &ntb_ethtool_ops);
+
+        dev->qp = ntb_transport_create_queue(ndev, pdev, &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;
+
+        list_add(&dev->list, &dev_list);
+        pr_info("%s: %s created\n", KBUILD_MODNAME, ndev->name);
+        return 0;
+
+err1:
+        ntb_transport_free_queue(dev->qp);
+err:
+        free_netdev(ndev);
+        return rc;
+}
+
+static void __exit ntb_netdev_remove(struct pci_dev *pdev)
+{
+        struct net_device *ndev;
+        struct ntb_netdev *dev;
+
+        list_for_each_entry(dev, &dev_list, list) {
+                if (dev->pdev == pdev)
+                        break;
+        }
+        if (dev == NULL)
+                return;
+
+        ndev = dev->ndev;
+
+        unregister_netdev(ndev);
+        ntb_transport_free_queue(dev->qp);
+        free_netdev(ndev);
+}
+
+static struct ntb_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_register_client_dev(KBUILD_MODNAME);
+        if (rc)
+                return rc;
+        return ntb_register_client(&ntb_netdev_client);
+}
+module_init(ntb_netdev_init_module);
+
+static void __exit ntb_netdev_exit_module(void)
+{
+        ntb_unregister_client(&ntb_netdev_client);
+        ntb_unregister_client_dev(KBUILD_MODNAME);
+        pr_info("%s: Driver removed\n", KBUILD_MODNAME);
+}
+module_exit(ntb_netdev_exit_module);