Subject: [PATCH 16/16] thunderbolt: Add support for networking over Thunderbolt cable

From: Mika Westerberg <[email-masked]>
Date: Mon, 18 Sep 2017 18:30:49 +0300

From: Amir Levy <[email-masked]>

ThunderboltIP is a protocol created by Apple to tunnel IP/ethernet
traffic over a Thunderbolt cable. The protocol consists of configuration
phase where each side sends ThunderboltIP login packets (the protocol is
determined by UUID in the XDomain packet header) over the configuration
channel. Once both sides get positive acknowledgment to their login
packet, they configure high-speed DMA path accordingly. This DMA path is
then used to transmit and receive networking traffic.

This patch creates a virtual ethernet interface the host software can
use in the same way as any other networking interface. Once the
interface is brought up successfully network packets get tunneled over
the Thunderbolt cable to the remote host and back.

The connection is terminated by sending a ThunderboltIP logout packet
over the configuration channel. We do this when the network interface is
brought down by user or the driver is unloaded.

Signed-off-by: Amir Levy <[email-masked]>
Signed-off-by: Michael Jamet <[email-masked]>
Signed-off-by: Mika Westerberg <[email-masked]>
Reviewed-by: Yehezkel Bernat <[email-masked]>
---
 Documentation/admin-guide/thunderbolt.rst |   24 +
 drivers/thunderbolt/Kconfig               |   12 +
 drivers/thunderbolt/Makefile              |    3 +
 drivers/thunderbolt/net.c                 | 1392 +++++++++++++++++++++++++++++
 4 files changed, 1431 insertions(+)
 create mode 100644 drivers/thunderbolt/net.c

diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst
index 6a4cd1f159ca..5c62d11d77e8 100644
--- a/Documentation/admin-guide/thunderbolt.rst
+++ b/Documentation/admin-guide/thunderbolt.rst
@@ -197,3 +197,27 @@ information is missing.
 
 To recover from this mode, one needs to flash a valid NVM image to the
 host host controller in the same way it is done in the previous chapter.
+
+Networking over Thunderbolt cable
+---------------------------------
+Thunderbolt technology allows software communication across two hosts
+connected by a Thunderbolt cable.
+
+It is possible to tunnel any kind of traffic over Thunderbolt link but
+currently we only support Apple ThunderboltIP protocol.
+
+If the other host is running Windows or macOS only thing you need to
+do is to connect Thunderbolt cable between the two hosts, the
+``thunderbolt-net`` is loaded automatically. If the other host is also
+Linux you should load ``thunderbolt-net`` manually on one host (it does
+not matter which one)::
+
+  # modprobe thunderbolt-net
+
+This triggers module load on the other host automatically. If the driver
+is built-in to the kernel image, there is no need to do anything.
+
+The driver will create one virtual ethernet interface per Thunderbolt
+port which are named like ``thunderbolt0`` and so on. From this point
+you can either use standard userspace tools like ``ifconfig`` to
+configure the interface or let your GUI to handle it automatically.
diff --git a/drivers/thunderbolt/Kconfig b/drivers/thunderbolt/Kconfig
index f4869c38c7e4..c544c751025c 100644
--- a/drivers/thunderbolt/Kconfig
+++ b/drivers/thunderbolt/Kconfig
@@ -14,3 +14,15 @@ menuconfig THUNDERBOLT
 
 	  To compile this driver a module, choose M here. The module will be
 	  called thunderbolt.
+
+config THUNDERBOLT_NET
+	tristate "Networking over Thunderbolt cable"
+	depends on THUNDERBOLT && INET
+	help
+	  Select this if you want to create network between two
+	  computers over a Thunderbolt cable. The driver supports Apple
+	  ThunderboltIP protocol and allows communication with any host
+	  supporting the same protocol including Windows and macOS.
+
+	  To compile this driver a module, choose M here. The module will be
+	  called thunderbolt-net.
diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
index f2f0de27252b..4018031db0a3 100644
--- a/drivers/thunderbolt/Makefile
+++ b/drivers/thunderbolt/Makefile
@@ -1,3 +1,6 @@
 obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
 thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel_pci.o eeprom.o
 thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o
+
+thunderbolt-net-y += net.o
+obj-$(CONFIG_THUNDERBOLT_NET) += thunderbolt-net.o
diff --git a/drivers/thunderbolt/net.c b/drivers/thunderbolt/net.c
new file mode 100644
index 000000000000..a5bfa3916df7
--- /dev/null
+++ b/drivers/thunderbolt/net.c
@@ -0,0 +1,1392 @@
+/*
+ * Networking over Thunderbolt cable using Apple ThunderboltIP protocol
+ *
+ * Copyright (C) 2017, Intel Corporation
+ * Authors: Amir Levy <[email-masked]>
+ *          Michael Jamet <[email-masked]>
+ *          Mika Westerberg <[email-masked]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/atomic.h>
+#include <linux/highmem.h>
+#include <linux/if_vlan.h>
+#include <linux/jhash.h>
+#include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/sizes.h>
+#include <linux/thunderbolt.h>
+#include <linux/uuid.h>
+#include <linux/workqueue.h>
+#include <net/ip6_checksum.h>
+
+/* Protocol timeouts in ms */
+#define TBNET_LOGIN_DELAY	4500
+#define TBNET_LOGIN_TIMEOUT	500
+#define TBNET_LOGOUT_TIMEOUT	100
+
+#define TBNET_RING_SIZE		256
+#define TBNET_LOCAL_PATH	0xf
+#define TBNET_RX_HDR_SIZE	256
+#define TBNET_LOGIN_RETRIES	60
+#define TBNET_LOGOUT_RETRIES	5
+#define TBNET_MATCH_FRAGS_ID	BIT(1)
+#define TBNET_MAX_MTU		SZ_64K
+#define TBNET_FRAME_SIZE	SZ_4K
+#define TBNET_MAX_PAYLOAD_SIZE		\
+	(TBNET_FRAME_SIZE - sizeof(struct thunderbolt_ip_frame_header))
+
+#define TBNET_L0_PORT_NUM(route) ((route) & GENMASK(5, 0))
+
+/**
+ * struct thunderbolt_ip_frame_header - Header for each Thunderbolt frame
+ * @frame_size: size of the data with the frame
+ * @frame_index: running index on the frames
+ * @frame_id: ID of the frame to match frames to specific packet
+ * @frame_count: how many frames assembles a full packet
+ *
+ * Each data frame passed to the high-speed DMA ring has this header. If
+ * the XDomain network directory announces that %TBNET_MATCH_FRAGS_ID is
+ * supported then @frame_id is filled, otherwise it stays %0.
+ */
+struct thunderbolt_ip_frame_header {
+	u32 frame_size;
+	u16 frame_index;
+	u16 frame_id;
+	u32 frame_count;
+} __packed;
+
+enum thunderbolt_ip_frame_pdf {
+	TBIP_PDF_FRAME_START = 1,
+	TBIP_PDF_FRAME_END,
+};
+
+enum thunderbolt_ip_type {
+	TBIP_LOGIN,
+	TBIP_LOGIN_RESPONSE,
+	TBIP_LOGOUT,
+	TBIP_STATUS,
+};
+
+struct thunderbolt_ip_header {
+	u32 route_hi;
+	u32 route_lo;
+	u32 length_sn;
+	uuid_t uuid;
+	uuid_t initiator_uuid;
+	uuid_t target_uuid;
+	u32 type;
+	u32 command_id;
+} __packed;
+
+#define TBIP_HDR_LENGTH_MASK		GENMASK(5, 0)
+#define TBIP_HDR_SN_MASK		GENMASK(28, 27)
+#define TBIP_HDR_SN_SHIFT		27
+
+struct thunderbolt_ip_login {
+	struct thunderbolt_ip_header hdr;
+	u32 proto_version;
+	u32 transmit_path;
+	u32 reserved[4];
+} __packed;
+
+#define TBIP_LOGIN_PROTO_VERSION	1
+
+struct thunderbolt_ip_login_response {
+	struct thunderbolt_ip_header hdr;
+	u32 status;
+	u32 receiver_mac[2];
+	u32 receiver_mac_len;
+	u32 reserved[4];
+} __packed;
+
+struct thunderbolt_ip_logout {
+	struct thunderbolt_ip_header hdr;
+} __packed;
+
+struct thunderbolt_ip_status {
+	struct thunderbolt_ip_header hdr;
+	u32 status;
+} __packed;
+
+struct tbnet_stats {
+	u64 tx_packets;
+	u64 rx_packets;
+	u64 tx_bytes;
+	u64 rx_bytes;
+	u64 tx_errors;
+	u64 rx_length_errors;
+	u64 rx_over_errors;
+	u64 rx_crc_errors;
+	u64 rx_missed_errors;
+};
+
+struct tbnet_frame {
+	struct net_device *dev;
+	struct page *page;
+	struct ring_frame frame;
+};
+
+struct tbnet_ring {
+	struct tbnet_frame frames[TBNET_RING_SIZE];
+	unsigned int cons;
+	unsigned int prod;
+	struct tb_ring *ring;
+};
+
+/**
+ * struct tbnet - ThunderboltIP network driver private data
+ * @svc: XDomain service the driver is bound to
+ * @xd: XDomain the service blongs to
+ * @handler: ThunderboltIP configuration protocol handler
+ * @dev: Networking device
+ * @napi: NAPI structure for Rx polling
+ * @stats: Network statistics
+ * @skb: Network packet that is currently processed on Rx path
+ * @command_id: ID used for next configuration protocol packet
+ * @login_sent: ThunderboltIP login message successfully sent
+ * @login_received: ThunderboltIP login message received from the remote
+ *		    host
+ * @transmit_path: HopID the other end needs to use building the
+ *		   opposite side path.
+ * @connection_lock: Lock serializing access to @login_sent,
+ *		     @login_received and @transmit_path.
+ * @login_retries: Number of login retries currently done
+ * @login_work: Worker to send ThunderboltIP login packets
+ * @connected_work: Worker that finalizes the ThunderboltIP connection
+ *		    setup and enables DMA paths for high speed data
+ *		    transfers
+ * @rx_hdr: Copy of the currently processed Rx frame. Used when a
+ *	    network packet consists of multiple Thunderbolt frames.
+ *	    In host byte order.
+ * @rx_ring: Software ring holding Rx frames
+ * @frame_id: Frame ID use for next Tx packet (if
+ *	      %TBNET_MATCH_FRAGS_ID is supported in both ends)
+ * @tx_ring: Software ring holding Tx frames
+ */
+struct tbnet {
+	const struct tb_service *svc;
+	struct tb_xdomain *xd;
+	struct tb_protocol_handler handler;
+	struct net_device *dev;
+	struct napi_struct napi;
+	struct tbnet_stats stats;
+	struct sk_buff *skb;
+	atomic_t command_id;
+	bool login_sent;
+	bool login_received;
+	u32 transmit_path;
+	struct mutex connection_lock;
+	int login_retries;
+	struct delayed_work login_work;
+	struct work_struct connected_work;
+	struct thunderbolt_ip_frame_header rx_hdr;
+	struct tbnet_ring rx_ring;
+	atomic_t frame_id;
+	struct tbnet_ring tx_ring;
+};
+
+/* Network property directory UUID */
+static const uuid_t tbnet_dir_uuid =
+	UUID_INIT(0xc66189ca, 0x1cce, 0x4195,
+		  0xbd, 0xb8, 0x49, 0x59, 0x2e, 0x5f, 0x5a, 0x4f);
+
+/* ThunderboltIP configuration protocol UUID */
+static const uuid_t tbnet_svc_uuid =
+	UUID_INIT(0x798f589e, 0x3616, 0x8a47,
+		  0x97, 0xc6, 0x56, 0x64, 0xa9, 0x20, 0xc8, 0xdd);
+
+static struct tb_property_dir *tbnet_dir;
+
+static void tbnet_fill_header(struct thunderbolt_ip_header *hdr, u64 route,
+	u8 sequence, const uuid_t *initiator_uuid, const uuid_t *target_uuid,
+	enum thunderbolt_ip_type type, size_t size, u32 command_id)
+{
+	u32 length_sn;
+
+	/* Length does not include route_hi/lo and length_sn fields */
+	length_sn = (size - 3 * 4) / 4;
+	length_sn |= (sequence << TBIP_HDR_SN_SHIFT) & TBIP_HDR_SN_MASK;
+
+	hdr->route_hi = upper_32_bits(route);
+	hdr->route_lo = lower_32_bits(route);
+	hdr->length_sn = length_sn;
+	uuid_copy(&hdr->uuid, &tbnet_svc_uuid);
+	uuid_copy(&hdr->initiator_uuid, initiator_uuid);
+	uuid_copy(&hdr->target_uuid, target_uuid);
+	hdr->type = type;
+	hdr->command_id = command_id;
+}
+
+static int tbnet_login_response(struct tbnet *net, u64 route, u8 sequence,
+				u32 command_id)
+{
+	struct thunderbolt_ip_login_response reply;
+	struct tb_xdomain *xd = net->xd;
+
+	memset(&reply, 0, sizeof(reply));
+	tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
+			  xd->remote_uuid, TBIP_LOGIN_RESPONSE, sizeof(reply),
+			  command_id);
+	memcpy(reply.receiver_mac, net->dev->dev_addr, ETH_ALEN);
+	reply.receiver_mac_len = ETH_ALEN;
+
+	return tb_xdomain_response(xd, &reply, sizeof(reply),
+				   TB_CFG_PKG_XDOMAIN_RESP);
+}
+
+static int tbnet_login_request(struct tbnet *net, u8 sequence)
+{
+	struct thunderbolt_ip_login_response reply;
+	struct thunderbolt_ip_login request;
+	struct tb_xdomain *xd = net->xd;
+
+	memset(&request, 0, sizeof(request));
+	tbnet_fill_header(&request.hdr, xd->route, sequence, xd->local_uuid,
+			  xd->remote_uuid, TBIP_LOGIN, sizeof(request),
+			  atomic_inc_return(&net->command_id));
+
+	request.proto_version = TBIP_LOGIN_PROTO_VERSION;
+	request.transmit_path = TBNET_LOCAL_PATH;
+
+	return tb_xdomain_request(xd, &request, sizeof(request),
+				  TB_CFG_PKG_XDOMAIN_RESP, &reply,
+				  sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
+				  TBNET_LOGIN_TIMEOUT);
+}
+
+static int tbnet_logout_response(struct tbnet *net, u64 route, u8 sequence,
+				  u32 command_id)
+{
+	struct thunderbolt_ip_status reply;
+	struct tb_xdomain *xd = net->xd;
+
+	memset(&reply, 0, sizeof(reply));
+	tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
+			  xd->remote_uuid, TBIP_STATUS, sizeof(reply),
+			  atomic_inc_return(&net->command_id));
+	return tb_xdomain_response(xd, &reply, sizeof(reply),
+				   TB_CFG_PKG_XDOMAIN_RESP);
+}
+
+static int tbnet_logout_request(struct tbnet *net)
+{
+	struct thunderbolt_ip_logout request;
+	struct thunderbolt_ip_status reply;
+	struct tb_xdomain *xd = net->xd;
+
+	memset(&request, 0, sizeof(request));
+	tbnet_fill_header(&request.hdr, xd->route, 0, xd->local_uuid,
+			  xd->remote_uuid, TBIP_LOGOUT, sizeof(request),
+			  atomic_inc_return(&net->command_id));
+
+	return tb_xdomain_request(xd, &request, sizeof(request),
+				  TB_CFG_PKG_XDOMAIN_RESP, &reply,
+				  sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
+				  TBNET_LOGOUT_TIMEOUT);
+}
+
+static void start_login(struct tbnet *net)
+{
+	mutex_lock(&net->connection_lock);
+	net->login_sent = false;
+	net->login_received = false;
+	mutex_unlock(&net->connection_lock);
+
+	queue_delayed_work(system_long_wq, &net->login_work,
+			   msecs_to_jiffies(1000));
+}
+
+static void stop_login(struct tbnet *net)
+{
+	cancel_delayed_work_sync(&net->login_work);
+	cancel_work_sync(&net->connected_work);
+}
+
+static inline unsigned int tbnet_frame_size(const struct tbnet_frame *tf)
+{
+	return tf->frame.size ? : TBNET_FRAME_SIZE;
+}
+
+static void tbnet_free_buffers(struct tbnet_ring *ring)
+{
+	unsigned int i;
+
+	for (i = 0; i < TBNET_RING_SIZE; i++) {
+		struct device *dma_dev = tb_ring_dma_device(ring->ring);
+		struct tbnet_frame *tf = &ring->frames[i];
+		enum dma_data_direction dir;
+		size_t size;
+
+		if (!tf->page)
+			continue;
+
+		if (ring->ring->is_tx) {
+			dir = DMA_TO_DEVICE;
+			size = tbnet_frame_size(tf);
+		} else {
+			dir = DMA_FROM_DEVICE;
+			size = TBNET_FRAME_SIZE;
+		}
+
+		dma_unmap_page(dma_dev, tf->frame.buffer_phy, size, dir);
+		__free_page(tf->page);
+		tf->page = NULL;
+	}
+
+	ring->cons = 0;
+	ring->prod = 0;
+}
+
+static void tbnet_tear_down(struct tbnet *net, bool send_logout)
+{
+	netif_carrier_off(net->dev);
+	netif_stop_queue(net->dev);
+
+	stop_login(net);
+
+	mutex_lock(&net->connection_lock);
+
+	if (net->login_sent && net->login_received) {
+		int retries = TBNET_LOGOUT_RETRIES;
+
+		while (send_logout && retries-- > 0) {
+			int ret = tbnet_logout_request(net);
+			if (ret != -ETIMEDOUT)
+				break;
+		}
+
+		tb_ring_stop(net->rx_ring.ring);
+		tb_ring_stop(net->tx_ring.ring);
+		tbnet_free_buffers(&net->rx_ring);
+		tbnet_free_buffers(&net->tx_ring);
+
+		if (tb_xdomain_disable_paths(net->xd))
+			netdev_warn(net->dev, "failed to disable DMA paths\n");
+	}
+
+	net->login_retries = 0;
+	net->login_sent = false;
+	net->login_received = false;
+
+	mutex_unlock(&net->connection_lock);
+}
+
+static int tbnet_handle_packet(const void *buf, size_t size, void *data)
+{
+	const struct thunderbolt_ip_login *pkg = buf;
+	struct tbnet *net = data;
+	u32 command_id;
+	int ret = 0;
+	u8 sequence;
+	u64 route;
+
+	/* Make sure the packet is for us */
+	if (size < sizeof(struct thunderbolt_ip_header))
+		return 0;
+	if (!uuid_equal(&pkg->hdr.initiator_uuid, net->xd->remote_uuid))
+		return 0;
+	if (!uuid_equal(&pkg->hdr.target_uuid, net->xd->local_uuid))
+		return 0;
+
+	route = ((u64)pkg->hdr.route_hi << 32) | pkg->hdr.route_lo;
+	route &= ~BIT_ULL(63);
+	if (route != net->xd->route)
+		return 0;
+
+	sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
+	sequence >>= TBIP_HDR_SN_SHIFT;
+	command_id = pkg->hdr.command_id;
+
+	switch (pkg->hdr.type) {
+	case TBIP_LOGIN:
+		if (!netif_running(net->dev))
+			break;
+
+		ret = tbnet_login_response(net, route, sequence,
+					   pkg->hdr.command_id);
+		if (!ret) {
+			mutex_lock(&net->connection_lock);
+			net->login_received = true;
+			net->transmit_path = pkg->transmit_path;
+
+			/*
+			 * If we reached the number of max retries or
+			 * previous logout, schedule another round of
+			 * login retries
+			 */
+			if (net->login_retries >= TBNET_LOGIN_RETRIES ||
+			    !net->login_sent) {
+				net->login_retries = 0;
+				queue_delayed_work(system_long_wq,
+						   &net->login_work, 0);
+			}
+			mutex_unlock(&net->connection_lock);
+
+			queue_work(system_long_wq, &net->connected_work);
+		}
+		break;
+
+	case TBIP_LOGOUT:
+		ret = tbnet_logout_response(net, route, sequence, command_id);
+		if (!ret)
+			tbnet_tear_down(net, false);
+		break;
+
+	default:
+		return 0;
+	}
+
+	if (ret)
+		netdev_warn(net->dev, "failed to send ThunderboltIP response\n");
+
+	return 1;
+}
+
+static unsigned int tbnet_available_buffers(const struct tbnet_ring *ring)
+{
+	return ring->prod - ring->cons;
+}
+
+static int tbnet_alloc_rx_buffers(struct tbnet *net, unsigned int nbuffers)
+{
+	struct tbnet_ring *ring = &net->rx_ring;
+	int ret;
+
+	while (nbuffers-- > 0) {
+		struct device *dma_dev = tb_ring_dma_device(ring->ring);
+		unsigned int index = ring->prod & (TBNET_RING_SIZE - 1);
+		struct tbnet_frame *tf = &ring->frames[index];
+		dma_addr_t dma_addr;
+
+		if (tf->page)
+			break;
+
+		tf->page = dev_alloc_page();
+		if (!tf->page) {
+			ret = -ENOMEM;
+			goto err_free;
+		}
+
+		dma_addr = dma_map_page(dma_dev, tf->page, 0,
+				TBNET_FRAME_SIZE, DMA_FROM_DEVICE);
+		if (dma_mapping_error(dma_dev, dma_addr)) {
+			ret = -ENOMEM;
+			goto err_free;
+		}
+
+		tf->frame.buffer_phy = dma_addr;
+		tf->dev = net->dev;
+
+		tb_ring_rx(ring->ring, &tf->frame);
+
+		ring->prod++;
+	}
+
+	return 0;
+
+err_free:
+	tbnet_free_buffers(ring);
+	return ret;
+}
+
+static struct tbnet_frame *tbnet_get_tx_buffer(struct tbnet *net)
+{
+	struct tbnet_ring *ring = &net->tx_ring;
+	struct tbnet_frame *tf;
+	unsigned int index;
+
+	if (!tbnet_available_buffers(ring))
+		return NULL;
+
+	index = ring->cons++ & (TBNET_RING_SIZE - 1);
+
+	tf = &ring->frames[index];
+	tf->frame.size = 0;
+	tf->frame.buffer_phy = 0;
+
+	return tf;
+}
+
+static void tbnet_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
+			      bool canceled)
+{
+	struct tbnet_frame *tf = container_of(frame, typeof(*tf), frame);
+	struct device *dma_dev = tb_ring_dma_device(ring);
+	struct tbnet *net = netdev_priv(tf->dev);
+
+	dma_unmap_page(dma_dev, tf->frame.buffer_phy, tbnet_frame_size(tf),
+		       DMA_TO_DEVICE);
+
+	/* Return buffer to the ring */
+	net->tx_ring.prod++;
+
+	if (tbnet_available_buffers(&net->tx_ring) >= TBNET_RING_SIZE / 2)
+		netif_wake_queue(net->dev);
+}
+
+static int tbnet_alloc_tx_buffers(struct tbnet *net)
+{
+	struct tbnet_ring *ring = &net->tx_ring;
+	unsigned int i;
+
+	for (i = 0; i < TBNET_RING_SIZE; i++) {
+		struct tbnet_frame *tf = &ring->frames[i];
+
+		tf->page = alloc_page(GFP_KERNEL);
+		if (!tf->page) {
+			tbnet_free_buffers(ring);
+			return -ENOMEM;
+		}
+
+		tf->dev = net->dev;
+		tf->frame.callback = tbnet_tx_callback;
+		tf->frame.sof = TBIP_PDF_FRAME_START;
+		tf->frame.eof = TBIP_PDF_FRAME_END;
+	}
+
+	ring->cons = 0;
+	ring->prod = TBNET_RING_SIZE - 1;
+
+	return 0;
+}
+
+static void tbnet_connected_work(struct work_struct *work)
+{
+	struct tbnet *net = container_of(work, typeof(*net), connected_work);
+	bool connected;
+	int ret;
+
+	if (netif_carrier_ok(net->dev))
+		return;
+
+	mutex_lock(&net->connection_lock);
+	connected = net->login_sent && net->login_received;
+	mutex_unlock(&net->connection_lock);
+
+	if (!connected)
+		return;
+
+	/*
+	 * Both logins successful so enable the high-speed DMA paths and
+	 * start the network device queue.
+	 */
+	ret = tb_xdomain_enable_paths(net->xd, TBNET_LOCAL_PATH,
+				      net->rx_ring.ring->hop,
+				      net->transmit_path,
+				      net->tx_ring.ring->hop);
+	if (ret) {
+		netdev_err(net->dev, "failed to enable DMA paths\n");
+		return;
+	}
+
+	tb_ring_start(net->tx_ring.ring);
+	tb_ring_start(net->rx_ring.ring);
+
+	ret = tbnet_alloc_rx_buffers(net, TBNET_RING_SIZE);
+	if (ret)
+		goto err_stop_rings;
+
+	ret = tbnet_alloc_tx_buffers(net);
+	if (ret)
+		goto err_free_rx_buffers;
+
+	netif_carrier_on(net->dev);
+	netif_start_queue(net->dev);
+	return;
+
+err_free_rx_buffers:
+	tbnet_free_buffers(&net->rx_ring);
+err_stop_rings:
+	tb_ring_stop(net->rx_ring.ring);
+	tb_ring_stop(net->tx_ring.ring);
+}
+
+static void tbnet_login_work(struct work_struct *work)
+{
+	struct tbnet *net = container_of(work, typeof(*net), login_work.work);
+	unsigned long delay = msecs_to_jiffies(TBNET_LOGIN_DELAY);
+	int ret;
+
+	if (netif_carrier_ok(net->dev))
+		return;
+
+	ret = tbnet_login_request(net, net->login_retries % 4);
+	if (ret) {
+		if (net->login_retries++ < TBNET_LOGIN_RETRIES) {
+			queue_delayed_work(system_long_wq, &net->login_work,
+					   delay);
+		} else {
+			netdev_info(net->dev, "ThunderboltIP login timed out\n");
+		}
+	} else {
+		net->login_retries = 0;
+
+		mutex_lock(&net->connection_lock);
+		net->login_sent = true;
+		mutex_unlock(&net->connection_lock);
+
+		queue_work(system_long_wq, &net->connected_work);
+	}
+}
+
+static bool tbnet_check_frame(struct tbnet *net,
+			       const struct tbnet_frame *tf)
+{
+	u32 frame_id, frame_count, frame_size, frame_index;
+	const struct thunderbolt_ip_frame_header *hdr;
+	unsigned int size;
+
+	if (tf->frame.flags & RING_DESC_CRC_ERROR) {
+		net->stats.rx_crc_errors++;
+		return false;
+	} else if (tf->frame.flags & RING_DESC_BUFFER_OVERRUN) {
+		net->stats.rx_over_errors++;
+		return false;
+	}
+
+	/* Should be greater than just header i.e. contains data */
+	size = tbnet_frame_size(tf);
+	if (size <= sizeof(*hdr)) {
+		net->stats.rx_length_errors++;
+		return false;
+	}
+
+	hdr = page_address(tf->page);
+	frame_count = le32_to_cpu(hdr->frame_count);
+	frame_size = le32_to_cpu(hdr->frame_size);
+	frame_index = le16_to_cpu(hdr->frame_index);
+	frame_id = le16_to_cpu(hdr->frame_id);
+
+	if ((frame_size > size - sizeof(*hdr)) || !frame_size) {
+		net->stats.rx_length_errors++;
+		return false;
+	}
+
+	/*
+	 * In case we're in the middle of packet, validate the frame
+	 * header based on first fragment of the packet.
+	 */
+	if (net->skb && net->rx_hdr.frame_count) {
+		/* Check the frame count fits the count field */
+		if (frame_count != net->rx_hdr.frame_count) {
+			net->stats.rx_length_errors++;
+			return false;
+		}
+
+		/*
+		 * Check the frame identifiers are incremented correctly,
+		 * and id is matching.
+		 */
+		if (frame_index != net->rx_hdr.frame_index + 1 ||
+		    frame_id != net->rx_hdr.frame_id) {
+			net->stats.rx_missed_errors++;
+			return false;
+		}
+
+		if (net->skb->len + frame_size > TBNET_MAX_MTU) {
+			net->stats.rx_length_errors++;
+			return false;
+		}
+
+		return true;
+	}
+
+	/* Start of packet, validate the frame header */
+	if (frame_count == 0 || frame_count > TBNET_RING_SIZE / 4) {
+		net->stats.rx_length_errors++;
+		return false;
+	}
+	if (frame_index != 0) {
+		net->stats.rx_missed_errors++;
+		return false;
+	}
+	if (frame_count > 1 && frame_size < TBNET_RX_HDR_SIZE) {
+		net->stats.rx_length_errors++;
+		return false;
+	}
+
+	return true;
+}
+
+static void tbnet_pull_tail(struct sk_buff *skb)
+{
+	skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
+	unsigned int pull_len;
+	void *hdr;
+
+	hdr = skb_frag_address(frag);
+	pull_len = eth_get_headlen(hdr, TBNET_RX_HDR_SIZE);
+
+	/* Align pull length to size of long to optimize memcpy performance */
+	skb_copy_to_linear_data(skb, hdr, ALIGN(pull_len, sizeof(long)));
+
+	/* Update all of the pointers */
+	skb_frag_size_sub(frag, pull_len);
+	frag->page_offset += pull_len;
+	skb->data_len -= pull_len;
+	skb->tail += pull_len;
+}
+
+static int tbnet_poll(struct napi_struct *napi, int budget)
+{
+	struct tbnet *net = container_of(napi, struct tbnet, napi);
+	unsigned int cleaned_count = tbnet_available_buffers(&net->rx_ring);
+	struct device *dma_dev = tb_ring_dma_device(net->rx_ring.ring);
+	unsigned int rx_packets = 0;
+
+	while (rx_packets < budget) {
+		u32 size, frame_size, frame_count, frame_index;
+		const struct thunderbolt_ip_frame_header *hdr;
+		unsigned int hdr_size = sizeof(*hdr);
+		struct sk_buff *skb = NULL;
+		struct ring_frame *frame;
+		struct tbnet_frame *tf;
+		bool last = true;
+
+		/*
+		 * Return some buffers to hardware, one at a time is too
+		 * slow so allocate MAX_SKB_FRAGS buffers at the same
+		 * time.
+		 */
+		if (cleaned_count >= MAX_SKB_FRAGS) {
+			tbnet_alloc_rx_buffers(net, cleaned_count);
+			cleaned_count = 0;
+		}
+
+		frame = tb_ring_poll(net->rx_ring.ring);
+		if (!frame)
+			break;
+
+		dma_unmap_page(dma_dev, frame->buffer_phy, TBNET_FRAME_SIZE,
+			       DMA_FROM_DEVICE);
+
+		tf = container_of(frame, typeof(*tf), frame);
+		size = tbnet_frame_size(tf);
+		hdr = page_address(tf->page);
+
+		if (!tbnet_check_frame(net, tf)) {
+			__free_page(tf->page);
+			tf->page = NULL;
+			net->rx_ring.cons++;
+			cleaned_count++;
+			dev_kfree_skb_any(net->skb);
+			net->skb = NULL;
+			continue;
+		}
+
+		frame_count = le32_to_cpu(hdr->frame_count);
+		frame_size = le32_to_cpu(hdr->frame_size);
+		frame_index = le16_to_cpu(hdr->frame_index);
+		last = frame_index == frame_count - 1;
+
+		skb = net->skb;
+		if (!skb) {
+			skb = netdev_alloc_skb_ip_align(net->dev,
+							TBNET_RX_HDR_SIZE);
+			net->skb = skb;
+		}
+		if (!skb)
+			break;
+
+		/*
+		 * Single small buffer we can copy directly to the
+		 * header part of the skb.
+		 */
+		if (hdr->frame_count == 1 && frame_size <= TBNET_RX_HDR_SIZE) {
+			const void *data = hdr + 1;
+
+			memcpy(__skb_put(skb, frame_size), data,
+			       ALIGN(frame_size, sizeof(long)));
+
+			__free_page(tf->page);
+		} else {
+			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+					tf->page, hdr_size, frame_size, size);
+			if (last)
+				tbnet_pull_tail(skb);
+		}
+
+		tf->page = NULL;
+		net->rx_ring.cons++;
+		cleaned_count++;
+
+		net->rx_hdr.frame_count = frame_count;
+		net->rx_hdr.frame_size = frame_size;
+		net->rx_hdr.frame_index = frame_index;
+		net->rx_hdr.frame_id = le16_to_cpu(hdr->frame_id);
+
+		rx_packets++;
+		net->stats.rx_bytes += frame_size;
+
+		if (last) {
+			skb->protocol = eth_type_trans(skb, net->dev);
+			napi_gro_receive(&net->napi, skb);
+			net->skb = NULL;
+		}
+	}
+
+	net->stats.rx_packets += rx_packets;
+
+	if (cleaned_count)
+		tbnet_alloc_rx_buffers(net, cleaned_count);
+
+	if (rx_packets >= budget)
+		return budget;
+
+	napi_complete_done(napi, rx_packets);
+	/* Re-enable the ring interrupt */
+	tb_ring_poll_complete(net->rx_ring.ring);
+
+	return rx_packets;
+}
+
+static void tbnet_start_poll(void *data)
+{
+	struct tbnet *net = data;
+
+	napi_schedule(&net->napi);
+}
+
+static int tbnet_open(struct net_device *dev)
+{
+	struct tbnet *net = netdev_priv(dev);
+	struct tb_xdomain *xd = net->xd;
+	u16 sof_mask, eof_mask;
+	struct tb_ring *ring;
+
+	netif_carrier_off(dev);
+
+	ring = tb_ring_alloc_tx(xd->tb->nhi, -1, TBNET_RING_SIZE,
+				RING_FLAG_FRAME);
+	if (!ring) {
+		netdev_err(dev, "failed to allocate Tx ring\n");
+		return -ENOMEM;
+	}
+	net->tx_ring.ring = ring;
+
+	sof_mask = BIT(TBIP_PDF_FRAME_START);
+	eof_mask = BIT(TBIP_PDF_FRAME_END);
+
+	ring = tb_ring_alloc_rx(xd->tb->nhi, -1, TBNET_RING_SIZE,
+				RING_FLAG_FRAME | RING_FLAG_E2E, sof_mask,
+				eof_mask, tbnet_start_poll, net);
+	if (!ring) {
+		netdev_err(dev, "failed to allocate Rx ring\n");
+		tb_ring_free(net->tx_ring.ring);
+		net->tx_ring.ring = NULL;
+		return -ENOMEM;
+	}
+	net->rx_ring.ring = ring;
+
+	napi_enable(&net->napi);
+	start_login(net);
+
+	return 0;
+}
+
+static int tbnet_stop(struct net_device *dev)
+{
+	struct tbnet *net = netdev_priv(dev);
+
+	napi_disable(&net->napi);
+
+	tbnet_tear_down(net, true);
+
+	tb_ring_free(net->rx_ring.ring);
+	net->rx_ring.ring = NULL;
+	tb_ring_free(net->tx_ring.ring);
+	net->tx_ring.ring = NULL;
+
+	return 0;
+}
+
+static bool tbnet_xmit_map(struct device *dma_dev, struct tbnet_frame *tf)
+{
+	dma_addr_t dma_addr;
+
+	dma_addr = dma_map_page(dma_dev, tf->page, 0, tbnet_frame_size(tf),
+				DMA_TO_DEVICE);
+	if (dma_mapping_error(dma_dev, dma_addr))
+		return false;
+
+	tf->frame.buffer_phy = dma_addr;
+	return true;
+}
+
+static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
+				struct tbnet_frame **frames, u32 frame_count)
+{
+	struct thunderbolt_ip_frame_header *hdr = page_address(frames[0]->page);
+	struct device *dma_dev = tb_ring_dma_device(net->tx_ring.ring);
+	__wsum wsum = htonl(skb->len - skb_transport_offset(skb));
+	unsigned int i, len, offset = skb_transport_offset(skb);
+	__be16 protocol = skb->protocol;
+	void *data = skb->data;
+	void *dest = hdr + 1;
+	__sum16 *tucso;
+
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		/*
+		 * No need to calculate checksum so we just update the
+		 * total frame count and map the frames for DMA.
+		 */
+		for (i = 0; i < frame_count; i++) {
+			hdr = page_address(frames[i]->page);
+			hdr->frame_count = cpu_to_le32(frame_count);
+			if (!tbnet_xmit_map(dma_dev, frames[i]))
+				goto err_unmap;
+		}
+
+		return true;
+	}
+
+	if (protocol == htons(ETH_P_8021Q)) {
+		struct vlan_hdr *vhdr, vh;
+
+		vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(vh), &vh);
+		if (!vhdr)
+			return false;
+
+		protocol = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	/*
+	 * Data points on the beginning of packet.
+	 * Check is the checksum absolute place in the packet.
+	 * ipcso will update IP checksum.
+	 * tucso will update TCP/UPD checksum.
+	 */
+	if (protocol == htons(ETH_P_IP)) {
+		__sum16 *ipcso = dest + ((void *)&(ip_hdr(skb)->check) - data);
+
+		*ipcso = 0;
+		*ipcso = ip_fast_csum(dest + skb_network_offset(skb),
+				      ip_hdr(skb)->ihl);
+
+		if (ip_hdr(skb)->protocol == IPPROTO_TCP)
+			tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
+		else if (ip_hdr(skb)->protocol == IPPROTO_UDP)
+			tucso = dest + ((void *)&(udp_hdr(skb)->check) - data);
+		else
+			return false;
+
+		*tucso = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
+					    ip_hdr(skb)->daddr, 0,
+					    ip_hdr(skb)->protocol, 0);
+	} else if (skb_is_gso_v6(skb)) {
+		tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
+		*tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+					  &ipv6_hdr(skb)->daddr, 0,
+					  IPPROTO_TCP, 0);
+		return false;
+	} else if (protocol == htons(ETH_P_IPV6)) {
+		tucso = dest + skb_checksum_start_offset(skb) + skb->csum_offset;
+		*tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+					  &ipv6_hdr(skb)->daddr, 0,
+					  ipv6_hdr(skb)->nexthdr, 0);
+	} else {
+		return false;
+	}
+
+	/*
+	 * First frame was headers, rest of the frames contain data.
+	 * Calculate checksum over each frame.
+	 */
+	for (i = 0; i < frame_count; i++) {
+		hdr = page_address(frames[i]->page);
+		dest = (void *)(hdr + 1) + offset;
+		len = le32_to_cpu(hdr->frame_size) - offset;
+		wsum = csum_partial(dest, len, wsum);
+		hdr->frame_count = cpu_to_le32(frame_count);
+
+		offset = 0;
+	}
+
+	*tucso = csum_fold(wsum);
+
+	/*
+	 * Checksum is finally calculated and we don't touch the memory
+	 * anymore, so DMA map the frames now.
+	 */
+	for (i = 0; i < frame_count; i++) {
+		if (!tbnet_xmit_map(dma_dev, frames[i]))
+			goto err_unmap;
+	}
+
+	return true;
+
+err_unmap:
+	for (--i; i > 0; i--)
+		dma_unmap_page(dma_dev, frames[i]->frame.buffer_phy,
+			       tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
+
+	return false;
+}
+
+static void *tbnet_kmap_frag(struct sk_buff *skb, unsigned int frag_num,
+			      unsigned int *len)
+{
+	const skb_frag_t *frag = &skb_shinfo(skb)->frags[frag_num];
+
+	*len = skb_frag_size(frag);
+	return kmap_atomic(skb_frag_page(frag)) + frag->page_offset;
+}
+
+static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	struct tbnet *net = netdev_priv(dev);
+	struct tbnet_frame *frames[MAX_SKB_FRAGS];
+	u16 frame_id = atomic_read(&net->frame_id);
+	struct thunderbolt_ip_frame_header *hdr;
+	unsigned int len = skb_headlen(skb);
+	unsigned int data_len = skb->len;
+	unsigned int nframes, i;
+	unsigned int frag = 0;
+	void *src = skb->data;
+	u32 frame_index = 0;
+	bool unmap = false;
+	void *dest;
+
+	nframes = DIV_ROUND_UP(data_len, TBNET_MAX_PAYLOAD_SIZE);
+	if (tbnet_available_buffers(&net->tx_ring) < nframes) {
+		netif_stop_queue(net->dev);
+		return NETDEV_TX_BUSY;
+	}
+
+	frames[frame_index] = tbnet_get_tx_buffer(net);
+	if (!frames[frame_index])
+		goto err_drop;
+
+	hdr = page_address(frames[frame_index]->page);
+	dest = hdr + 1;
+
+	/* If overall packet is bigger than the frame data size */
+	while (data_len > TBNET_MAX_PAYLOAD_SIZE) {
+		unsigned int size_left = TBNET_MAX_PAYLOAD_SIZE;
+
+		hdr->frame_size = cpu_to_le32(TBNET_MAX_PAYLOAD_SIZE);
+		hdr->frame_index = cpu_to_le16(frame_index);
+		hdr->frame_id = cpu_to_le16(frame_id);
+
+		do {
+			if (len > size_left) {
+				/*
+				 * Copy data onto Tx buffer data with
+				 * full frame size then break and go to
+				 * next frame
+				 */
+				memcpy(dest, src, size_left);
+				len -= size_left;
+				dest += size_left;
+				src += size_left;
+				break;
+			}
+
+			memcpy(dest, src, len);
+			size_left -= len;
+			dest += len;
+
+			if (unmap) {
+				kunmap_atomic(src);
+				unmap = false;
+			}
+
+			/* Ensure all fragments have been processed */
+			if (frag < skb_shinfo(skb)->nr_frags) {
+				/* Map and then unmap quickly */
+				src = tbnet_kmap_frag(skb, frag++, &len);
+				unmap = true;
+			} else if (unlikely(size_left > 0)) {
+				goto err_drop;
+			}
+		} while (size_left > 0);
+
+		data_len -= TBNET_MAX_PAYLOAD_SIZE;
+		frame_index++;
+
+		frames[frame_index] = tbnet_get_tx_buffer(net);
+		if (!frames[frame_index])
+			goto err_drop;
+
+		hdr = page_address(frames[frame_index]->page);
+		dest = hdr + 1;
+	}
+
+	hdr->frame_size = cpu_to_le32(data_len);
+	hdr->frame_index = cpu_to_le16(frame_index);
+	hdr->frame_id = cpu_to_le16(frame_id);
+
+	frames[frame_index]->frame.size = data_len + sizeof(*hdr);
+
+	/* In case  the remaining data_len is smaller than a frame */
+	while (len < data_len) {
+		memcpy(dest, src, len);
+		data_len -= len;
+		dest += len;
+
+		if (unmap) {
+			kunmap_atomic(src);
+			unmap = false;
+		}
+
+		if (frag < skb_shinfo(skb)->nr_frags) {
+			src = tbnet_kmap_frag(skb, frag++, &len);
+			unmap = true;
+		} else if (unlikely(data_len > 0)) {
+			goto err_drop;
+		}
+	}
+
+	memcpy(dest, src, data_len);
+
+	if (unmap)
+		kunmap_atomic(src);
+
+	if (!tbnet_xmit_csum_and_map(net, skb, frames, frame_index + 1))
+		goto err_drop;
+
+	for (i = 0; i < frame_index + 1; i++)
+		tb_ring_tx(net->tx_ring.ring, &frames[i]->frame);
+
+	if (net->svc->prtcstns & TBNET_MATCH_FRAGS_ID)
+		atomic_inc(&net->frame_id);
+
+	net->stats.tx_packets++;
+	net->stats.tx_bytes += skb->len;
+
+	dev_consume_skb_any(skb);
+
+	return NETDEV_TX_OK;
+
+err_drop:
+	/* We can re-use the buffers */
+	net->tx_ring.cons -= frame_index;
+
+	dev_kfree_skb_any(skb);
+	net->stats.tx_errors++;
+
+	return NETDEV_TX_OK;
+}
+
+static void tbnet_get_stats64(struct net_device *dev,
+			      struct rtnl_link_stats64 *stats)
+{
+	struct tbnet *net = netdev_priv(dev);
+
+	stats->tx_packets = net->stats.tx_packets;
+	stats->rx_packets = net->stats.rx_packets;
+	stats->tx_bytes = net->stats.tx_bytes;
+	stats->rx_bytes = net->stats.rx_bytes;
+	stats->tx_errors = net->stats.tx_errors;
+	stats->rx_errors = net->stats.rx_length_errors +
+		net->stats.rx_over_errors + net->stats.rx_crc_errors +
+		net->stats.rx_missed_errors;
+	stats->rx_length_errors = net->stats.rx_length_errors;
+	stats->rx_over_errors = net->stats.rx_over_errors;
+	stats->rx_crc_errors = net->stats.rx_crc_errors;
+	stats->rx_missed_errors = net->stats.rx_missed_errors;
+}
+
+static const struct net_device_ops tbnet_netdev_ops = {
+	.ndo_open = tbnet_open,
+	.ndo_stop = tbnet_stop,
+	.ndo_start_xmit = tbnet_start_xmit,
+	.ndo_get_stats64 = tbnet_get_stats64,
+};
+
+static void tbnet_generate_mac(struct net_device *dev)
+{
+	const struct tbnet *net = netdev_priv(dev);
+	const struct tb_xdomain *xd = net->xd;
+	u8 phy_port;
+	u32 hash;
+
+	phy_port = tb_phy_port_from_link(TBNET_L0_PORT_NUM(xd->route));
+
+	/* Unicast and locally administered MAC */
+	dev->dev_addr[0] = phy_port << 4 | 0x02;
+	hash = jhash2((u32 *)xd->local_uuid, 4, 0);
+	memcpy(dev->dev_addr + 1, &hash, sizeof(hash));
+	hash = jhash2((u32 *)xd->local_uuid, 4, hash);
+	dev->dev_addr[5] = hash & 0xff;
+}
+
+static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)
+{
+	struct tb_xdomain *xd = tb_service_parent(svc);
+	struct net_device *dev;
+	struct tbnet *net;
+	int ret;
+
+	dev = alloc_etherdev(sizeof(*net));
+	if (!dev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(dev, &svc->dev);
+
+	net = netdev_priv(dev);
+	INIT_DELAYED_WORK(&net->login_work, tbnet_login_work);
+	INIT_WORK(&net->connected_work, tbnet_connected_work);
+	mutex_init(&net->connection_lock);
+	atomic_set(&net->command_id, 0);
+	atomic_set(&net->frame_id, 0);
+	net->svc = svc;
+	net->dev = dev;
+	net->xd = xd;
+
+	tbnet_generate_mac(dev);
+
+	strcpy(dev->name, "thunderbolt%d");
+	dev->netdev_ops = &tbnet_netdev_ops;
+
+	/*
+	 * ThunderboltIP takes advantage of TSO packets but instead of
+	 * segmenting them we just split the packet into Thunderbolt
+	 * frames (maximum payload size of each frame is 4084 bytes) and
+	 * calculate checksum over the whole packet here.
+	 *
+	 * The receiving side does the opposite if the host OS supports
+	 * LRO, otherwise it needs to split the large packet into MTU
+	 * sized smaller packets.
+	 *
+	 * In order to receive large packets from the networking stack,
+	 * we need to announce support for most of the offloading
+	 * features here.
+	 */
+	dev->hw_features = NETIF_F_SG | NETIF_F_ALL_TSO | NETIF_F_GRO |
+			   NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+	dev->features = dev->hw_features | NETIF_F_HIGHDMA;
+	dev->hard_header_len += sizeof(struct thunderbolt_ip_frame_header);
+
+	netif_napi_add(dev, &net->napi, tbnet_poll, NAPI_POLL_WEIGHT);
+
+	/* MTU range: 68 - 65522 */
+	dev->min_mtu = ETH_MIN_MTU;
+	dev->max_mtu = TBNET_MAX_MTU - ETH_HLEN;
+
+	ret = register_netdev(dev);
+	if (ret) {
+		free_netdev(dev);
+		return ret;
+	}
+
+	net->handler.uuid = &tbnet_svc_uuid;
+	net->handler.callback = tbnet_handle_packet,
+	net->handler.data = net;
+	tb_register_protocol_handler(&net->handler);
+
+	tb_service_set_drvdata(svc, net);
+
+	return 0;
+}
+
+static void tbnet_remove(struct tb_service *svc)
+{
+	struct tbnet *net = tb_service_get_drvdata(svc);
+
+	unregister_netdev(net->dev);
+	tb_unregister_protocol_handler(&net->handler);
+	free_netdev(net->dev);
+}
+
+static void tbnet_shutdown(struct tb_service *svc)
+{
+	tbnet_tear_down(tb_service_get_drvdata(svc), true);
+}
+
+static int __maybe_unused tbnet_suspend(struct device *dev)
+{
+	struct tb_service *svc = tb_to_service(dev);
+	struct tbnet *net = tb_service_get_drvdata(svc);
+
+	stop_login(net);
+	if (netif_running(net->dev)) {
+		netif_device_detach(net->dev);
+		tb_ring_stop(net->rx_ring.ring);
+		tb_ring_stop(net->tx_ring.ring);
+		tbnet_free_buffers(&net->rx_ring);
+		tbnet_free_buffers(&net->tx_ring);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused tbnet_resume(struct device *dev)
+{
+	struct tb_service *svc = tb_to_service(dev);
+	struct tbnet *net = tb_service_get_drvdata(svc);
+
+	netif_carrier_off(net->dev);
+	if (netif_running(net->dev)) {
+		netif_device_attach(net->dev);
+		start_login(net);
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops tbnet_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(tbnet_suspend, tbnet_resume)
+};
+
+static const struct tb_service_id tbnet_ids[] = {
+	{ TB_SERVICE("network", 1) },
+	{ },
+};
+MODULE_DEVICE_TABLE(tbsvc, tbnet_ids);
+
+static struct tb_service_driver tbnet_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "thunderbolt-net",
+		.pm = &tbnet_pm_ops,
+	},
+	.probe = tbnet_probe,
+	.remove = tbnet_remove,
+	.shutdown = tbnet_shutdown,
+	.id_table = tbnet_ids,
+};
+
+static int __init tbnet_init(void)
+{
+	int ret;
+
+	tbnet_dir = tb_property_create_dir(&tbnet_dir_uuid);
+	if (!tbnet_dir)
+		return -ENOMEM;
+
+	tb_property_add_immediate(tbnet_dir, "prtcid", 1);
+	tb_property_add_immediate(tbnet_dir, "prtcvers", 1);
+	tb_property_add_immediate(tbnet_dir, "prtcrevs", 1);
+	tb_property_add_immediate(tbnet_dir, "prtcstns",
+				  TBNET_MATCH_FRAGS_ID);
+
+	ret = tb_register_property_dir("network", tbnet_dir);
+	if (ret) {
+		tb_property_free_dir(tbnet_dir);
+		return ret;
+	}
+
+	return tb_register_service_driver(&tbnet_driver);
+}
+module_init(tbnet_init);
+
+static void __exit tbnet_exit(void)
+{
+	tb_unregister_service_driver(&tbnet_driver);
+	tb_unregister_property_dir("network", tbnet_dir);
+	tb_property_free_dir(tbnet_dir);
+}
+module_exit(tbnet_exit);
+
+MODULE_AUTHOR("Amir Levy <[email-masked]>");
+MODULE_AUTHOR("Michael Jamet <[email-masked]>");
+MODULE_AUTHOR("Mika Westerberg <[email-masked]>");
+MODULE_DESCRIPTION("Thunderbolt networking driver");
+MODULE_LICENSE("GPL v2");
-- 
2.13.5