v4.19.13 snapshot.
diff --git a/drivers/net/ntb_netdev.c b/drivers/net/ntb_netdev.c
new file mode 100644
index 0000000..b12023b
--- /dev/null
+++ b/drivers/net/ntb_netdev.c
@@ -0,0 +1,518 @@
+/*
+ * 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 list_head list;
+	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 LIST_HEAD(dev_list);
+
+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 + msecs_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);
+	memcpy(ndev->dev_addr, ndev->perm_addr, ndev->addr_len);
+
+	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;
+
+	list_add(&dev->list, &dev_list);
+	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 ntb_dev *ntb;
+	struct net_device *ndev;
+	struct pci_dev *pdev;
+	struct ntb_netdev *dev;
+	bool found = false;
+
+	ntb = dev_ntb(client_dev->parent);
+	pdev = ntb->pdev;
+
+	list_for_each_entry(dev, &dev_list, list) {
+		if (dev->pdev == pdev) {
+			found = true;
+			break;
+		}
+	}
+	if (!found)
+		return;
+
+	list_del(&dev->list);
+
+	ndev = dev->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);