kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 746 insertions, 0 deletions

diff --git a/drivers/net/ntb_netdev.c b/drivers/net/ntb_netdev.c
new file mode 100644
index 000000000..029a4a532
--- /dev/null
+++ b/drivers/net/ntb_netdev.c
@@ -0,0 +1,746 @@
+// SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause
+/*
+ * PCIe NTB Network Linux driver
+ */
+#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>
+#include <linux/slab.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;
+
+#define NTB_NETDEV_MAX_QUEUES		64
+#define NTB_NETDEV_DEFAULT_QUEUES	1
+
+struct ntb_netdev;
+
+struct ntb_netdev_queue {
+	struct ntb_netdev *ntdev;
+	struct ntb_transport_qp *qp;
+	struct timer_list tx_timer;
+	u16 qid;
+};
+
+struct ntb_netdev {
+	struct pci_dev *pdev;
+	struct device *client_dev;
+	struct net_device *ndev;
+	unsigned int num_queues;
+	struct ntb_netdev_queue *queues;
+};
+
+#define	NTB_TX_TIMEOUT_MS	1000
+#define	NTB_RXQ_SIZE		100
+
+static void ntb_netdev_update_carrier(struct ntb_netdev *dev)
+{
+	struct net_device *ndev;
+	bool any_up = false;
+	unsigned int i;
+
+	ndev = dev->ndev;
+
+	for (i = 0; i < dev->num_queues; i++) {
+		if (ntb_transport_link_query(dev->queues[i].qp)) {
+			any_up = true;
+			break;
+		}
+	}
+
+	if (any_up)
+		netif_carrier_on(ndev);
+	else
+		netif_carrier_off(ndev);
+}
+
+static void ntb_netdev_queue_rx_drain(struct ntb_netdev_queue *queue)
+{
+	struct sk_buff *skb;
+	int len;
+
+	while ((skb = ntb_transport_rx_remove(queue->qp, &len)))
+		dev_kfree_skb(skb);
+}
+
+static int ntb_netdev_queue_rx_fill(struct net_device *ndev,
+				    struct ntb_netdev_queue *queue)
+{
+	struct sk_buff *skb;
+	int rc, i;
+
+	for (i = 0; i < NTB_RXQ_SIZE; i++) {
+		skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
+		if (!skb)
+			return -ENOMEM;
+
+		rc = ntb_transport_rx_enqueue(queue->qp, skb, skb->data,
+					      ndev->mtu + ETH_HLEN);
+		if (rc) {
+			dev_kfree_skb(skb);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+static void ntb_netdev_event_handler(void *data, int link_is_up)
+{
+	struct ntb_netdev_queue *q = data;
+	struct ntb_netdev *dev = q->ntdev;
+	struct net_device *ndev;
+
+	ndev = dev->ndev;
+
+	netdev_dbg(ndev, "Event %x, Link %x, qp %u\n", link_is_up,
+		   ntb_transport_link_query(q->qp), q->qid);
+
+	if (netif_running(ndev)) {
+		if (link_is_up)
+			netif_wake_subqueue(ndev, q->qid);
+		else
+			netif_stop_subqueue(ndev, q->qid);
+	}
+
+	ntb_netdev_update_carrier(dev);
+}
+
+static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data,
+				  void *data, int len)
+{
+	struct ntb_netdev_queue *q = qp_data;
+	struct ntb_netdev *dev = q->ntdev;
+	struct sk_buff *skb, *new_skb;
+	struct net_device *ndev;
+	int rc;
+
+	ndev = dev->ndev;
+	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;
+	}
+
+	new_skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
+	if (!new_skb) {
+		ndev->stats.rx_dropped++;
+		goto enqueue_again;
+	}
+
+	skb_put(skb, len);
+	skb->protocol = eth_type_trans(skb, ndev);
+	skb->ip_summed = CHECKSUM_NONE;
+	skb_record_rx_queue(skb, q->qid);
+
+	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 = new_skb;
+
+enqueue_again:
+	rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
+	if (rc) {
+		dev_kfree_skb_any(skb);
+		ndev->stats.rx_errors++;
+		ndev->stats.rx_fifo_errors++;
+	}
+}
+
+static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev,
+				      struct ntb_netdev_queue *q, int size)
+{
+	netif_stop_subqueue(netdev, q->qid);
+
+	/* 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(q->qp) < size)) {
+		mod_timer(&q->tx_timer, jiffies + usecs_to_jiffies(tx_time));
+		return -EBUSY;
+	}
+
+	/* The subqueue must be kept stopped if the link is down */
+	if (ntb_transport_link_query(q->qp))
+		netif_start_subqueue(netdev, q->qid);
+
+	return 0;
+}
+
+static int ntb_netdev_maybe_stop_tx(struct net_device *ndev,
+				    struct ntb_netdev_queue *q, int size)
+{
+	if (__netif_subqueue_stopped(ndev, q->qid) ||
+	    (ntb_transport_tx_free_entry(q->qp) >= size))
+		return 0;
+
+	return __ntb_netdev_maybe_stop_tx(ndev, q, size);
+}
+
+static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data,
+				  void *data, int len)
+{
+	struct ntb_netdev_queue *q = qp_data;
+	struct ntb_netdev *dev = q->ntdev;
+	struct net_device *ndev;
+	struct sk_buff *skb;
+
+	ndev = dev->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_any(skb);
+
+	if (ntb_transport_tx_free_entry(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_subqueue_stopped(ndev, q->qid) &&
+		    ntb_transport_link_query(q->qp))
+			netif_wake_subqueue(ndev, q->qid);
+	}
+}
+
+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 netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
+					 struct net_device *ndev)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+	u16 qid = skb_get_queue_mapping(skb);
+	struct ntb_netdev_queue *q;
+	int rc;
+
+	q = &dev->queues[qid];
+
+	ntb_netdev_maybe_stop_tx(ndev, q, tx_stop);
+
+	rc = ntb_transport_tx_enqueue(q->qp, skb, skb->data, skb->len);
+	if (rc)
+		goto err;
+
+	/* check for next submit */
+	ntb_netdev_maybe_stop_tx(ndev, q, 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_queue *q = timer_container_of(q, t, tx_timer);
+	struct ntb_netdev *dev = q->ntdev;
+	struct net_device *ndev;
+
+	ndev = dev->ndev;
+
+	if (ntb_transport_tx_free_entry(q->qp) < tx_stop) {
+		mod_timer(&q->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();
+
+		/* The subqueue must be kept stopped if the link is down */
+		if (__netif_subqueue_stopped(ndev, q->qid) &&
+		    ntb_transport_link_query(q->qp))
+			netif_wake_subqueue(ndev, q->qid);
+	}
+}
+
+static int ntb_netdev_open(struct net_device *ndev)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+	struct ntb_netdev_queue *queue;
+	unsigned int q;
+	int rc = 0;
+
+	/* Add some empty rx bufs for each queue */
+	for (q = 0; q < dev->num_queues; q++) {
+		queue = &dev->queues[q];
+
+		rc = ntb_netdev_queue_rx_fill(ndev, queue);
+		if (rc)
+			goto err;
+
+		timer_setup(&queue->tx_timer, ntb_netdev_tx_timer, 0);
+	}
+
+	netif_carrier_off(ndev);
+	netif_tx_stop_all_queues(ndev);
+
+	for (q = 0; q < dev->num_queues; q++)
+		ntb_transport_link_up(dev->queues[q].qp);
+
+	return 0;
+
+err:
+	for (q = 0; q < dev->num_queues; q++) {
+		queue = &dev->queues[q];
+		ntb_netdev_queue_rx_drain(queue);
+	}
+	return rc;
+}
+
+static int ntb_netdev_close(struct net_device *ndev)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+	struct ntb_netdev_queue *queue;
+	unsigned int q;
+
+	netif_tx_stop_all_queues(ndev);
+	netif_carrier_off(ndev);
+
+	for (q = 0; q < dev->num_queues; q++) {
+		queue = &dev->queues[q];
+
+		ntb_transport_link_down(queue->qp);
+		ntb_netdev_queue_rx_drain(queue);
+		timer_delete_sync(&queue->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 ntb_netdev_queue *queue;
+	struct sk_buff *skb;
+	unsigned int q, i;
+	int len, rc = 0;
+
+	if (new_mtu > ntb_transport_max_size(dev->queues[0].qp) - ETH_HLEN)
+		return -EINVAL;
+
+	if (!netif_running(ndev)) {
+		WRITE_ONCE(ndev->mtu, new_mtu);
+		return 0;
+	}
+
+	/* Bring down the link and dispose of posted rx entries */
+	for (q = 0; q < dev->num_queues; q++)
+		ntb_transport_link_down(dev->queues[q].qp);
+
+	if (ndev->mtu < new_mtu) {
+		for (q = 0; q < dev->num_queues; q++) {
+			queue = &dev->queues[q];
+
+			for (i = 0;
+			     (skb = ntb_transport_rx_remove(queue->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(queue->qp, skb,
+							      skb->data,
+							      new_mtu +
+							      ETH_HLEN);
+				if (rc) {
+					dev_kfree_skb(skb);
+					goto err;
+				}
+			}
+		}
+	}
+
+	WRITE_ONCE(ndev->mtu, new_mtu);
+
+	for (q = 0; q < dev->num_queues; q++)
+		ntb_transport_link_up(dev->queues[q].qp);
+
+	return 0;
+
+err:
+	for (q = 0; q < dev->num_queues; q++) {
+		struct ntb_netdev_queue *queue = &dev->queues[q];
+
+		ntb_transport_link_down(queue->qp);
+
+		ntb_netdev_queue_rx_drain(queue);
+	}
+
+	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);
+
+	strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
+	strscpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
+	strscpy(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 void ntb_get_channels(struct net_device *ndev,
+			     struct ethtool_channels *channels)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+
+	channels->combined_count = dev->num_queues;
+	channels->max_combined = ndev->num_tx_queues;
+}
+
+static int ntb_inc_channels(struct net_device *ndev,
+			    unsigned int old, unsigned int new)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+	bool running = netif_running(ndev);
+	struct ntb_netdev_queue *queue;
+	unsigned int q, created;
+	int rc;
+
+	created = old;
+	for (q = old; q < new; q++) {
+		queue = &dev->queues[q];
+
+		queue->ntdev = dev;
+		queue->qid = q;
+		queue->qp = ntb_transport_create_queue(queue, dev->client_dev,
+						       &ntb_netdev_handlers);
+		if (!queue->qp) {
+			rc = -ENOSPC;
+			goto err_new;
+		}
+		created++;
+
+		if (!running)
+			continue;
+
+		timer_setup(&queue->tx_timer, ntb_netdev_tx_timer, 0);
+
+		rc = ntb_netdev_queue_rx_fill(ndev, queue);
+		if (rc)
+			goto err_new;
+
+		/*
+		 * Carrier may already be on due to other QPs. Keep the new
+		 * subqueue stopped until we get a Link Up event for this QP.
+		 */
+		netif_stop_subqueue(ndev, q);
+	}
+
+	rc = netif_set_real_num_queues(ndev, new, new);
+	if (rc)
+		goto err_new;
+
+	dev->num_queues = new;
+
+	if (running)
+		for (q = old; q < new; q++)
+			ntb_transport_link_up(dev->queues[q].qp);
+
+	return 0;
+
+err_new:
+	if (running) {
+		unsigned int rollback = created;
+
+		while (rollback-- > old) {
+			queue = &dev->queues[rollback];
+			ntb_transport_link_down(queue->qp);
+			ntb_netdev_queue_rx_drain(queue);
+			timer_delete_sync(&queue->tx_timer);
+		}
+	}
+	while (created-- > old) {
+		queue = &dev->queues[created];
+		ntb_transport_free_queue(queue->qp);
+		queue->qp = NULL;
+	}
+	return rc;
+}
+
+static int ntb_dec_channels(struct net_device *ndev,
+			    unsigned int old, unsigned int new)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+	bool running = netif_running(ndev);
+	struct ntb_netdev_queue *queue;
+	unsigned int q;
+	int rc;
+
+	if (running)
+		for (q = new; q < old; q++)
+			netif_stop_subqueue(ndev, q);
+
+	rc = netif_set_real_num_queues(ndev, new, new);
+	if (rc)
+		goto err;
+
+	/* Publish new queue count before invalidating QP pointers */
+	dev->num_queues = new;
+
+	for (q = new; q < old; q++) {
+		queue = &dev->queues[q];
+
+		if (running) {
+			ntb_transport_link_down(queue->qp);
+			ntb_netdev_queue_rx_drain(queue);
+			timer_delete_sync(&queue->tx_timer);
+		}
+
+		ntb_transport_free_queue(queue->qp);
+		queue->qp = NULL;
+	}
+
+	/*
+	 * It might be the case that the removed queues are the only queues that
+	 * were up, so see if the global carrier needs to change.
+	 */
+	ntb_netdev_update_carrier(dev);
+	return 0;
+
+err:
+	if (running) {
+		for (q = new; q < old; q++)
+			netif_wake_subqueue(ndev, q);
+	}
+	return rc;
+}
+
+static int ntb_set_channels(struct net_device *ndev,
+			    struct ethtool_channels *channels)
+{
+	struct ntb_netdev *dev = netdev_priv(ndev);
+	unsigned int new = channels->combined_count;
+	unsigned int old = dev->num_queues;
+
+	if (new == old)
+		return 0;
+
+	if (new < old)
+		return ntb_dec_channels(ndev, old, new);
+	else
+		return ntb_inc_channels(ndev, old, new);
+}
+
+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,
+	.get_channels = ntb_get_channels,
+	.set_channels = ntb_set_channels,
+};
+
+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;
+	unsigned int q;
+	int rc;
+
+	ntb = dev_ntb(client_dev->parent);
+	pdev = ntb->pdev;
+	if (!pdev)
+		return -ENODEV;
+
+	ndev = alloc_etherdev_mq(sizeof(*dev), NTB_NETDEV_MAX_QUEUES);
+	if (!ndev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(ndev, client_dev);
+
+	dev = netdev_priv(ndev);
+	dev->ndev = ndev;
+	dev->pdev = pdev;
+	dev->client_dev = client_dev;
+	dev->num_queues = 0;
+
+	dev->queues = kzalloc_objs(*dev->queues, NTB_NETDEV_MAX_QUEUES,
+				   GFP_KERNEL);
+	if (!dev->queues) {
+		rc = -ENOMEM;
+		goto err_free_netdev;
+	}
+
+	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;
+
+	for (q = 0; q < NTB_NETDEV_DEFAULT_QUEUES; q++) {
+		struct ntb_netdev_queue *queue = &dev->queues[q];
+
+		queue->ntdev = dev;
+		queue->qid = q;
+		queue->qp = ntb_transport_create_queue(queue, client_dev,
+						       &ntb_netdev_handlers);
+		if (!queue->qp)
+			break;
+
+		dev->num_queues++;
+	}
+
+	if (!dev->num_queues) {
+		rc = -EIO;
+		goto err_free_queues;
+	}
+
+	rc = netif_set_real_num_queues(ndev, dev->num_queues, dev->num_queues);
+	if (rc)
+		goto err_free_qps;
+
+	ndev->mtu = ntb_transport_max_size(dev->queues[0].qp) - ETH_HLEN;
+
+	rc = register_netdev(ndev);
+	if (rc)
+		goto err_free_qps;
+
+	dev_set_drvdata(client_dev, ndev);
+	dev_info(&pdev->dev, "%s created with %u queue pairs\n",
+		 ndev->name, dev->num_queues);
+	return 0;
+
+err_free_qps:
+	for (q = 0; q < dev->num_queues; q++)
+		ntb_transport_free_queue(dev->queues[q].qp);
+
+err_free_queues:
+	kfree(dev->queues);
+
+err_free_netdev:
+	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);
+	unsigned int q;
+
+	unregister_netdev(ndev);
+	for (q = 0; q < dev->num_queues; q++)
+		ntb_transport_free_queue(dev->queues[q].qp);
+
+	kfree(dev->queues);
+	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;
+
+	rc = ntb_transport_register_client(&ntb_netdev_client);
+	if (rc) {
+		ntb_transport_unregister_client_dev(KBUILD_MODNAME);
+		return rc;
+	}
+
+	return 0;
+}
+late_initcall(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);