Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1542 insertions, 0 deletions

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
new file mode 100644
index 000000000..a56ea540a
--- /dev/null
+++ b/drivers/thunderbolt/tb.c
@@ -0,0 +1,1542 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - bus logic (NHI independent)
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2019, Intel Corporation
+ */
+
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/pm_runtime.h>
+
+#include "tb.h"
+#include "tb_regs.h"
+#include "tunnel.h"
+
+/**
+ * struct tb_cm - Simple Thunderbolt connection manager
+ * @tunnel_list: List of active tunnels
+ * @dp_resources: List of available DP resources for DP tunneling
+ * @hotplug_active: tb_handle_hotplug will stop progressing plug
+ *		    events and exit if this is not set (it needs to
+ *		    acquire the lock one more time). Used to drain wq
+ *		    after cfg has been paused.
+ * @remove_work: Work used to remove any unplugged routers after
+ *		 runtime resume
+ */
+struct tb_cm {
+	struct list_head tunnel_list;
+	struct list_head dp_resources;
+	bool hotplug_active;
+	struct delayed_work remove_work;
+};
+
+static inline struct tb *tcm_to_tb(struct tb_cm *tcm)
+{
+	return ((void *)tcm - sizeof(struct tb));
+}
+
+struct tb_hotplug_event {
+	struct work_struct work;
+	struct tb *tb;
+	u64 route;
+	u8 port;
+	bool unplug;
+};
+
+static void tb_handle_hotplug(struct work_struct *work);
+
+static void tb_queue_hotplug(struct tb *tb, u64 route, u8 port, bool unplug)
+{
+	struct tb_hotplug_event *ev;
+
+	ev = kmalloc(sizeof(*ev), GFP_KERNEL);
+	if (!ev)
+		return;
+
+	ev->tb = tb;
+	ev->route = route;
+	ev->port = port;
+	ev->unplug = unplug;
+	INIT_WORK(&ev->work, tb_handle_hotplug);
+	queue_work(tb->wq, &ev->work);
+}
+
+/* enumeration & hot plug handling */
+
+static void tb_add_dp_resources(struct tb_switch *sw)
+{
+	struct tb_cm *tcm = tb_priv(sw->tb);
+	struct tb_port *port;
+
+	tb_switch_for_each_port(sw, port) {
+		if (!tb_port_is_dpin(port))
+			continue;
+
+		if (!tb_switch_query_dp_resource(sw, port))
+			continue;
+
+		list_add_tail(&port->list, &tcm->dp_resources);
+		tb_port_dbg(port, "DP IN resource available\n");
+	}
+}
+
+static void tb_remove_dp_resources(struct tb_switch *sw)
+{
+	struct tb_cm *tcm = tb_priv(sw->tb);
+	struct tb_port *port, *tmp;
+
+	/* Clear children resources first */
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port))
+			tb_remove_dp_resources(port->remote->sw);
+	}
+
+	list_for_each_entry_safe(port, tmp, &tcm->dp_resources, list) {
+		if (port->sw == sw) {
+			tb_port_dbg(port, "DP OUT resource unavailable\n");
+			list_del_init(&port->list);
+		}
+	}
+}
+
+static void tb_discover_tunnels(struct tb_switch *sw)
+{
+	struct tb *tb = sw->tb;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *port;
+
+	tb_switch_for_each_port(sw, port) {
+		struct tb_tunnel *tunnel = NULL;
+
+		switch (port->config.type) {
+		case TB_TYPE_DP_HDMI_IN:
+			tunnel = tb_tunnel_discover_dp(tb, port);
+			break;
+
+		case TB_TYPE_PCIE_DOWN:
+			tunnel = tb_tunnel_discover_pci(tb, port);
+			break;
+
+		case TB_TYPE_USB3_DOWN:
+			tunnel = tb_tunnel_discover_usb3(tb, port);
+			break;
+
+		default:
+			break;
+		}
+
+		if (!tunnel)
+			continue;
+
+		if (tb_tunnel_is_pci(tunnel)) {
+			struct tb_switch *parent = tunnel->dst_port->sw;
+
+			while (parent != tunnel->src_port->sw) {
+				parent->boot = true;
+				parent = tb_switch_parent(parent);
+			}
+		} else if (tb_tunnel_is_dp(tunnel)) {
+			/* Keep the domain from powering down */
+			pm_runtime_get_sync(&tunnel->src_port->sw->dev);
+			pm_runtime_get_sync(&tunnel->dst_port->sw->dev);
+		}
+
+		list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	}
+
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port))
+			tb_discover_tunnels(port->remote->sw);
+	}
+}
+
+static int tb_port_configure_xdomain(struct tb_port *port)
+{
+	/*
+	 * XDomain paths currently only support single lane so we must
+	 * disable the other lane according to USB4 spec.
+	 */
+	tb_port_disable(port->dual_link_port);
+
+	if (tb_switch_is_usb4(port->sw))
+		return usb4_port_configure_xdomain(port);
+	return tb_lc_configure_xdomain(port);
+}
+
+static void tb_port_unconfigure_xdomain(struct tb_port *port)
+{
+	if (tb_switch_is_usb4(port->sw))
+		usb4_port_unconfigure_xdomain(port);
+	else
+		tb_lc_unconfigure_xdomain(port);
+
+	tb_port_enable(port->dual_link_port);
+}
+
+static void tb_scan_xdomain(struct tb_port *port)
+{
+	struct tb_switch *sw = port->sw;
+	struct tb *tb = sw->tb;
+	struct tb_xdomain *xd;
+	u64 route;
+
+	route = tb_downstream_route(port);
+	xd = tb_xdomain_find_by_route(tb, route);
+	if (xd) {
+		tb_xdomain_put(xd);
+		return;
+	}
+
+	xd = tb_xdomain_alloc(tb, &sw->dev, route, tb->root_switch->uuid,
+			      NULL);
+	if (xd) {
+		tb_port_at(route, sw)->xdomain = xd;
+		tb_port_configure_xdomain(port);
+		tb_xdomain_add(xd);
+	}
+}
+
+static int tb_enable_tmu(struct tb_switch *sw)
+{
+	int ret;
+
+	/* If it is already enabled in correct mode, don't touch it */
+	if (tb_switch_tmu_is_enabled(sw))
+		return 0;
+
+	ret = tb_switch_tmu_disable(sw);
+	if (ret)
+		return ret;
+
+	ret = tb_switch_tmu_post_time(sw);
+	if (ret)
+		return ret;
+
+	return tb_switch_tmu_enable(sw);
+}
+
+/**
+ * tb_find_unused_port() - return the first inactive port on @sw
+ * @sw: Switch to find the port on
+ * @type: Port type to look for
+ */
+static struct tb_port *tb_find_unused_port(struct tb_switch *sw,
+					   enum tb_port_type type)
+{
+	struct tb_port *port;
+
+	tb_switch_for_each_port(sw, port) {
+		if (tb_is_upstream_port(port))
+			continue;
+		if (port->config.type != type)
+			continue;
+		if (!port->cap_adap)
+			continue;
+		if (tb_port_is_enabled(port))
+			continue;
+		return port;
+	}
+	return NULL;
+}
+
+static struct tb_port *tb_find_usb3_down(struct tb_switch *sw,
+					 const struct tb_port *port)
+{
+	struct tb_port *down;
+
+	down = usb4_switch_map_usb3_down(sw, port);
+	if (down && !tb_usb3_port_is_enabled(down))
+		return down;
+	return NULL;
+}
+
+static struct tb_tunnel *tb_find_tunnel(struct tb *tb, enum tb_tunnel_type type,
+					struct tb_port *src_port,
+					struct tb_port *dst_port)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+
+	list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
+		if (tunnel->type == type &&
+		    ((src_port && src_port == tunnel->src_port) ||
+		     (dst_port && dst_port == tunnel->dst_port))) {
+			return tunnel;
+		}
+	}
+
+	return NULL;
+}
+
+static struct tb_tunnel *tb_find_first_usb3_tunnel(struct tb *tb,
+						   struct tb_port *src_port,
+						   struct tb_port *dst_port)
+{
+	struct tb_port *port, *usb3_down;
+	struct tb_switch *sw;
+
+	/* Pick the router that is deepest in the topology */
+	if (dst_port->sw->config.depth > src_port->sw->config.depth)
+		sw = dst_port->sw;
+	else
+		sw = src_port->sw;
+
+	/* Can't be the host router */
+	if (sw == tb->root_switch)
+		return NULL;
+
+	/* Find the downstream USB4 port that leads to this router */
+	port = tb_port_at(tb_route(sw), tb->root_switch);
+	/* Find the corresponding host router USB3 downstream port */
+	usb3_down = usb4_switch_map_usb3_down(tb->root_switch, port);
+	if (!usb3_down)
+		return NULL;
+
+	return tb_find_tunnel(tb, TB_TUNNEL_USB3, usb3_down, NULL);
+}
+
+static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
+	struct tb_port *dst_port, int *available_up, int *available_down)
+{
+	int usb3_consumed_up, usb3_consumed_down, ret;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+	struct tb_port *port;
+
+	tb_port_dbg(dst_port, "calculating available bandwidth\n");
+
+	tunnel = tb_find_first_usb3_tunnel(tb, src_port, dst_port);
+	if (tunnel) {
+		ret = tb_tunnel_consumed_bandwidth(tunnel, &usb3_consumed_up,
+						   &usb3_consumed_down);
+		if (ret)
+			return ret;
+	} else {
+		usb3_consumed_up = 0;
+		usb3_consumed_down = 0;
+	}
+
+	*available_up = *available_down = 40000;
+
+	/* Find the minimum available bandwidth over all links */
+	tb_for_each_port_on_path(src_port, dst_port, port) {
+		int link_speed, link_width, up_bw, down_bw;
+
+		if (!tb_port_is_null(port))
+			continue;
+
+		if (tb_is_upstream_port(port)) {
+			link_speed = port->sw->link_speed;
+		} else {
+			link_speed = tb_port_get_link_speed(port);
+			if (link_speed < 0)
+				return link_speed;
+		}
+
+		link_width = port->bonded ? 2 : 1;
+
+		up_bw = link_speed * link_width * 1000; /* Mb/s */
+		/* Leave 10% guard band */
+		up_bw -= up_bw / 10;
+		down_bw = up_bw;
+
+		tb_port_dbg(port, "link total bandwidth %d Mb/s\n", up_bw);
+
+		/*
+		 * Find all DP tunnels that cross the port and reduce
+		 * their consumed bandwidth from the available.
+		 */
+		list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
+			int dp_consumed_up, dp_consumed_down;
+
+			if (!tb_tunnel_is_dp(tunnel))
+				continue;
+
+			if (!tb_tunnel_port_on_path(tunnel, port))
+				continue;
+
+			ret = tb_tunnel_consumed_bandwidth(tunnel,
+							   &dp_consumed_up,
+							   &dp_consumed_down);
+			if (ret)
+				return ret;
+
+			up_bw -= dp_consumed_up;
+			down_bw -= dp_consumed_down;
+		}
+
+		/*
+		 * If USB3 is tunneled from the host router down to the
+		 * branch leading to port we need to take USB3 consumed
+		 * bandwidth into account regardless whether it actually
+		 * crosses the port.
+		 */
+		up_bw -= usb3_consumed_up;
+		down_bw -= usb3_consumed_down;
+
+		if (up_bw < *available_up)
+			*available_up = up_bw;
+		if (down_bw < *available_down)
+			*available_down = down_bw;
+	}
+
+	if (*available_up < 0)
+		*available_up = 0;
+	if (*available_down < 0)
+		*available_down = 0;
+
+	return 0;
+}
+
+static int tb_release_unused_usb3_bandwidth(struct tb *tb,
+					    struct tb_port *src_port,
+					    struct tb_port *dst_port)
+{
+	struct tb_tunnel *tunnel;
+
+	tunnel = tb_find_first_usb3_tunnel(tb, src_port, dst_port);
+	return tunnel ? tb_tunnel_release_unused_bandwidth(tunnel) : 0;
+}
+
+static void tb_reclaim_usb3_bandwidth(struct tb *tb, struct tb_port *src_port,
+				      struct tb_port *dst_port)
+{
+	int ret, available_up, available_down;
+	struct tb_tunnel *tunnel;
+
+	tunnel = tb_find_first_usb3_tunnel(tb, src_port, dst_port);
+	if (!tunnel)
+		return;
+
+	tb_dbg(tb, "reclaiming unused bandwidth for USB3\n");
+
+	/*
+	 * Calculate available bandwidth for the first hop USB3 tunnel.
+	 * That determines the whole USB3 bandwidth for this branch.
+	 */
+	ret = tb_available_bandwidth(tb, tunnel->src_port, tunnel->dst_port,
+				     &available_up, &available_down);
+	if (ret) {
+		tb_warn(tb, "failed to calculate available bandwidth\n");
+		return;
+	}
+
+	tb_dbg(tb, "available bandwidth for USB3 %d/%d Mb/s\n",
+	       available_up, available_down);
+
+	tb_tunnel_reclaim_available_bandwidth(tunnel, &available_up, &available_down);
+}
+
+static int tb_tunnel_usb3(struct tb *tb, struct tb_switch *sw)
+{
+	struct tb_switch *parent = tb_switch_parent(sw);
+	int ret, available_up, available_down;
+	struct tb_port *up, *down, *port;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+
+	up = tb_switch_find_port(sw, TB_TYPE_USB3_UP);
+	if (!up)
+		return 0;
+
+	if (!sw->link_usb4)
+		return 0;
+
+	/*
+	 * Look up available down port. Since we are chaining it should
+	 * be found right above this switch.
+	 */
+	port = tb_port_at(tb_route(sw), parent);
+	down = tb_find_usb3_down(parent, port);
+	if (!down)
+		return 0;
+
+	if (tb_route(parent)) {
+		struct tb_port *parent_up;
+		/*
+		 * Check first that the parent switch has its upstream USB3
+		 * port enabled. Otherwise the chain is not complete and
+		 * there is no point setting up a new tunnel.
+		 */
+		parent_up = tb_switch_find_port(parent, TB_TYPE_USB3_UP);
+		if (!parent_up || !tb_port_is_enabled(parent_up))
+			return 0;
+
+		/* Make all unused bandwidth available for the new tunnel */
+		ret = tb_release_unused_usb3_bandwidth(tb, down, up);
+		if (ret)
+			return ret;
+	}
+
+	ret = tb_available_bandwidth(tb, down, up, &available_up,
+				     &available_down);
+	if (ret)
+		goto err_reclaim;
+
+	tb_port_dbg(up, "available bandwidth for new USB3 tunnel %d/%d Mb/s\n",
+		    available_up, available_down);
+
+	tunnel = tb_tunnel_alloc_usb3(tb, up, down, available_up,
+				      available_down);
+	if (!tunnel) {
+		ret = -ENOMEM;
+		goto err_reclaim;
+	}
+
+	if (tb_tunnel_activate(tunnel)) {
+		tb_port_info(up,
+			     "USB3 tunnel activation failed, aborting\n");
+		ret = -EIO;
+		goto err_free;
+	}
+
+	list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	if (tb_route(parent))
+		tb_reclaim_usb3_bandwidth(tb, down, up);
+
+	return 0;
+
+err_free:
+	tb_tunnel_free(tunnel);
+err_reclaim:
+	if (tb_route(parent))
+		tb_reclaim_usb3_bandwidth(tb, down, up);
+
+	return ret;
+}
+
+static int tb_create_usb3_tunnels(struct tb_switch *sw)
+{
+	struct tb_port *port;
+	int ret;
+
+	if (tb_route(sw)) {
+		ret = tb_tunnel_usb3(sw->tb, sw);
+		if (ret)
+			return ret;
+	}
+
+	tb_switch_for_each_port(sw, port) {
+		if (!tb_port_has_remote(port))
+			continue;
+		ret = tb_create_usb3_tunnels(port->remote->sw);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void tb_scan_port(struct tb_port *port);
+
+/**
+ * tb_scan_switch() - scan for and initialize downstream switches
+ */
+static void tb_scan_switch(struct tb_switch *sw)
+{
+	struct tb_port *port;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	tb_switch_for_each_port(sw, port)
+		tb_scan_port(port);
+
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+}
+
+/**
+ * tb_scan_port() - check for and initialize switches below port
+ */
+static void tb_scan_port(struct tb_port *port)
+{
+	struct tb_cm *tcm = tb_priv(port->sw->tb);
+	struct tb_port *upstream_port;
+	struct tb_switch *sw;
+
+	if (tb_is_upstream_port(port))
+		return;
+
+	if (tb_port_is_dpout(port) && tb_dp_port_hpd_is_active(port) == 1 &&
+	    !tb_dp_port_is_enabled(port)) {
+		tb_port_dbg(port, "DP adapter HPD set, queuing hotplug\n");
+		tb_queue_hotplug(port->sw->tb, tb_route(port->sw), port->port,
+				 false);
+		return;
+	}
+
+	if (port->config.type != TB_TYPE_PORT)
+		return;
+	if (port->dual_link_port && port->link_nr)
+		return; /*
+			 * Downstream switch is reachable through two ports.
+			 * Only scan on the primary port (link_nr == 0).
+			 */
+	if (tb_wait_for_port(port, false) <= 0)
+		return;
+	if (port->remote) {
+		tb_port_dbg(port, "port already has a remote\n");
+		return;
+	}
+
+	tb_retimer_scan(port);
+
+	sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
+			     tb_downstream_route(port));
+	if (IS_ERR(sw)) {
+		/*
+		 * If there is an error accessing the connected switch
+		 * it may be connected to another domain. Also we allow
+		 * the other domain to be connected to a max depth switch.
+		 */
+		if (PTR_ERR(sw) == -EIO || PTR_ERR(sw) == -EADDRNOTAVAIL)
+			tb_scan_xdomain(port);
+		return;
+	}
+
+	if (tb_switch_configure(sw)) {
+		tb_switch_put(sw);
+		return;
+	}
+
+	/*
+	 * If there was previously another domain connected remove it
+	 * first.
+	 */
+	if (port->xdomain) {
+		tb_xdomain_remove(port->xdomain);
+		tb_port_unconfigure_xdomain(port);
+		port->xdomain = NULL;
+	}
+
+	/*
+	 * Do not send uevents until we have discovered all existing
+	 * tunnels and know which switches were authorized already by
+	 * the boot firmware.
+	 */
+	if (!tcm->hotplug_active)
+		dev_set_uevent_suppress(&sw->dev, true);
+
+	/*
+	 * At the moment Thunderbolt 2 and beyond (devices with LC) we
+	 * can support runtime PM.
+	 */
+	sw->rpm = sw->generation > 1;
+
+	if (tb_switch_add(sw)) {
+		tb_switch_put(sw);
+		return;
+	}
+
+	/* Link the switches using both links if available */
+	upstream_port = tb_upstream_port(sw);
+	port->remote = upstream_port;
+	upstream_port->remote = port;
+	if (port->dual_link_port && upstream_port->dual_link_port) {
+		port->dual_link_port->remote = upstream_port->dual_link_port;
+		upstream_port->dual_link_port->remote = port->dual_link_port;
+	}
+
+	/* Enable lane bonding if supported */
+	tb_switch_lane_bonding_enable(sw);
+	/* Set the link configured */
+	tb_switch_configure_link(sw);
+
+	if (tb_enable_tmu(sw))
+		tb_sw_warn(sw, "failed to enable TMU\n");
+
+	/* Scan upstream retimers */
+	tb_retimer_scan(upstream_port);
+
+	/*
+	 * Create USB 3.x tunnels only when the switch is plugged to the
+	 * domain. This is because we scan the domain also during discovery
+	 * and want to discover existing USB 3.x tunnels before we create
+	 * any new.
+	 */
+	if (tcm->hotplug_active && tb_tunnel_usb3(sw->tb, sw))
+		tb_sw_warn(sw, "USB3 tunnel creation failed\n");
+
+	tb_add_dp_resources(sw);
+	tb_scan_switch(sw);
+}
+
+static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
+{
+	struct tb_port *src_port, *dst_port;
+	struct tb *tb;
+
+	if (!tunnel)
+		return;
+
+	tb_tunnel_deactivate(tunnel);
+	list_del(&tunnel->list);
+
+	tb = tunnel->tb;
+	src_port = tunnel->src_port;
+	dst_port = tunnel->dst_port;
+
+	switch (tunnel->type) {
+	case TB_TUNNEL_DP:
+		/*
+		 * In case of DP tunnel make sure the DP IN resource is
+		 * deallocated properly.
+		 */
+		tb_switch_dealloc_dp_resource(src_port->sw, src_port);
+		/* Now we can allow the domain to runtime suspend again */
+		pm_runtime_mark_last_busy(&dst_port->sw->dev);
+		pm_runtime_put_autosuspend(&dst_port->sw->dev);
+		pm_runtime_mark_last_busy(&src_port->sw->dev);
+		pm_runtime_put_autosuspend(&src_port->sw->dev);
+		fallthrough;
+
+	case TB_TUNNEL_USB3:
+		tb_reclaim_usb3_bandwidth(tb, src_port, dst_port);
+		break;
+
+	default:
+		/*
+		 * PCIe and DMA tunnels do not consume guaranteed
+		 * bandwidth.
+		 */
+		break;
+	}
+
+	tb_tunnel_free(tunnel);
+}
+
+/**
+ * tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away
+ */
+static void tb_free_invalid_tunnels(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+	struct tb_tunnel *n;
+
+	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
+		if (tb_tunnel_is_invalid(tunnel))
+			tb_deactivate_and_free_tunnel(tunnel);
+	}
+}
+
+/**
+ * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches
+ */
+static void tb_free_unplugged_children(struct tb_switch *sw)
+{
+	struct tb_port *port;
+
+	tb_switch_for_each_port(sw, port) {
+		if (!tb_port_has_remote(port))
+			continue;
+
+		if (port->remote->sw->is_unplugged) {
+			tb_retimer_remove_all(port);
+			tb_remove_dp_resources(port->remote->sw);
+			tb_switch_unconfigure_link(port->remote->sw);
+			tb_switch_lane_bonding_disable(port->remote->sw);
+			tb_switch_remove(port->remote->sw);
+			port->remote = NULL;
+			if (port->dual_link_port)
+				port->dual_link_port->remote = NULL;
+		} else {
+			tb_free_unplugged_children(port->remote->sw);
+		}
+	}
+}
+
+static struct tb_port *tb_find_pcie_down(struct tb_switch *sw,
+					 const struct tb_port *port)
+{
+	struct tb_port *down = NULL;
+
+	/*
+	 * To keep plugging devices consistently in the same PCIe
+	 * hierarchy, do mapping here for switch downstream PCIe ports.
+	 */
+	if (tb_switch_is_usb4(sw)) {
+		down = usb4_switch_map_pcie_down(sw, port);
+	} else if (!tb_route(sw)) {
+		int phy_port = tb_phy_port_from_link(port->port);
+		int index;
+
+		/*
+		 * Hard-coded Thunderbolt port to PCIe down port mapping
+		 * per controller.
+		 */
+		if (tb_switch_is_cactus_ridge(sw) ||
+		    tb_switch_is_alpine_ridge(sw))
+			index = !phy_port ? 6 : 7;
+		else if (tb_switch_is_falcon_ridge(sw))
+			index = !phy_port ? 6 : 8;
+		else if (tb_switch_is_titan_ridge(sw))
+			index = !phy_port ? 8 : 9;
+		else
+			goto out;
+
+		/* Validate the hard-coding */
+		if (WARN_ON(index > sw->config.max_port_number))
+			goto out;
+
+		down = &sw->ports[index];
+	}
+
+	if (down) {
+		if (WARN_ON(!tb_port_is_pcie_down(down)))
+			goto out;
+		if (tb_pci_port_is_enabled(down))
+			goto out;
+
+		return down;
+	}
+
+out:
+	return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
+}
+
+static struct tb_port *tb_find_dp_out(struct tb *tb, struct tb_port *in)
+{
+	struct tb_port *host_port, *port;
+	struct tb_cm *tcm = tb_priv(tb);
+
+	host_port = tb_route(in->sw) ?
+		tb_port_at(tb_route(in->sw), tb->root_switch) : NULL;
+
+	list_for_each_entry(port, &tcm->dp_resources, list) {
+		if (!tb_port_is_dpout(port))
+			continue;
+
+		if (tb_port_is_enabled(port)) {
+			tb_port_dbg(port, "in use\n");
+			continue;
+		}
+
+		tb_port_dbg(port, "DP OUT available\n");
+
+		/*
+		 * Keep the DP tunnel under the topology starting from
+		 * the same host router downstream port.
+		 */
+		if (host_port && tb_route(port->sw)) {
+			struct tb_port *p;
+
+			p = tb_port_at(tb_route(port->sw), tb->root_switch);
+			if (p != host_port)
+				continue;
+		}
+
+		return port;
+	}
+
+	return NULL;
+}
+
+static void tb_tunnel_dp(struct tb *tb)
+{
+	int available_up, available_down, ret;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *port, *in, *out;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Find pair of inactive DP IN and DP OUT adapters and then
+	 * establish a DP tunnel between them.
+	 */
+	tb_dbg(tb, "looking for DP IN <-> DP OUT pairs:\n");
+
+	in = NULL;
+	out = NULL;
+	list_for_each_entry(port, &tcm->dp_resources, list) {
+		if (!tb_port_is_dpin(port))
+			continue;
+
+		if (tb_port_is_enabled(port)) {
+			tb_port_dbg(port, "in use\n");
+			continue;
+		}
+
+		tb_port_dbg(port, "DP IN available\n");
+
+		out = tb_find_dp_out(tb, port);
+		if (out) {
+			in = port;
+			break;
+		}
+	}
+
+	if (!in) {
+		tb_dbg(tb, "no suitable DP IN adapter available, not tunneling\n");
+		return;
+	}
+	if (!out) {
+		tb_dbg(tb, "no suitable DP OUT adapter available, not tunneling\n");
+		return;
+	}
+
+	/*
+	 * DP stream needs the domain to be active so runtime resume
+	 * both ends of the tunnel.
+	 *
+	 * This should bring the routers in the middle active as well
+	 * and keeps the domain from runtime suspending while the DP
+	 * tunnel is active.
+	 */
+	pm_runtime_get_sync(&in->sw->dev);
+	pm_runtime_get_sync(&out->sw->dev);
+
+	if (tb_switch_alloc_dp_resource(in->sw, in)) {
+		tb_port_dbg(in, "no resource available for DP IN, not tunneling\n");
+		goto err_rpm_put;
+	}
+
+	/* Make all unused USB3 bandwidth available for the new DP tunnel */
+	ret = tb_release_unused_usb3_bandwidth(tb, in, out);
+	if (ret) {
+		tb_warn(tb, "failed to release unused bandwidth\n");
+		goto err_dealloc_dp;
+	}
+
+	ret = tb_available_bandwidth(tb, in, out, &available_up,
+				     &available_down);
+	if (ret)
+		goto err_reclaim;
+
+	tb_dbg(tb, "available bandwidth for new DP tunnel %u/%u Mb/s\n",
+	       available_up, available_down);
+
+	tunnel = tb_tunnel_alloc_dp(tb, in, out, available_up, available_down);
+	if (!tunnel) {
+		tb_port_dbg(out, "could not allocate DP tunnel\n");
+		goto err_reclaim;
+	}
+
+	if (tb_tunnel_activate(tunnel)) {
+		tb_port_info(out, "DP tunnel activation failed, aborting\n");
+		goto err_free;
+	}
+
+	list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	tb_reclaim_usb3_bandwidth(tb, in, out);
+	return;
+
+err_free:
+	tb_tunnel_free(tunnel);
+err_reclaim:
+	tb_reclaim_usb3_bandwidth(tb, in, out);
+err_dealloc_dp:
+	tb_switch_dealloc_dp_resource(in->sw, in);
+err_rpm_put:
+	pm_runtime_mark_last_busy(&out->sw->dev);
+	pm_runtime_put_autosuspend(&out->sw->dev);
+	pm_runtime_mark_last_busy(&in->sw->dev);
+	pm_runtime_put_autosuspend(&in->sw->dev);
+}
+
+static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)
+{
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+
+	if (tb_port_is_dpin(port)) {
+		tb_port_dbg(port, "DP IN resource unavailable\n");
+		in = port;
+		out = NULL;
+	} else {
+		tb_port_dbg(port, "DP OUT resource unavailable\n");
+		in = NULL;
+		out = port;
+	}
+
+	tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, out);
+	tb_deactivate_and_free_tunnel(tunnel);
+	list_del_init(&port->list);
+
+	/*
+	 * See if there is another DP OUT port that can be used for
+	 * to create another tunnel.
+	 */
+	tb_tunnel_dp(tb);
+}
+
+static void tb_dp_resource_available(struct tb *tb, struct tb_port *port)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *p;
+
+	if (tb_port_is_enabled(port))
+		return;
+
+	list_for_each_entry(p, &tcm->dp_resources, list) {
+		if (p == port)
+			return;
+	}
+
+	tb_port_dbg(port, "DP %s resource available\n",
+		    tb_port_is_dpin(port) ? "IN" : "OUT");
+	list_add_tail(&port->list, &tcm->dp_resources);
+
+	/* Look for suitable DP IN <-> DP OUT pairs now */
+	tb_tunnel_dp(tb);
+}
+
+static void tb_disconnect_and_release_dp(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel, *n;
+
+	/*
+	 * Tear down all DP tunnels and release their resources. They
+	 * will be re-established after resume based on plug events.
+	 */
+	list_for_each_entry_safe_reverse(tunnel, n, &tcm->tunnel_list, list) {
+		if (tb_tunnel_is_dp(tunnel))
+			tb_deactivate_and_free_tunnel(tunnel);
+	}
+
+	while (!list_empty(&tcm->dp_resources)) {
+		struct tb_port *port;
+
+		port = list_first_entry(&tcm->dp_resources,
+					struct tb_port, list);
+		list_del_init(&port->list);
+	}
+}
+
+static int tb_tunnel_pci(struct tb *tb, struct tb_switch *sw)
+{
+	struct tb_port *up, *down, *port;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_switch *parent_sw;
+	struct tb_tunnel *tunnel;
+
+	up = tb_switch_find_port(sw, TB_TYPE_PCIE_UP);
+	if (!up)
+		return 0;
+
+	/*
+	 * Look up available down port. Since we are chaining it should
+	 * be found right above this switch.
+	 */
+	parent_sw = tb_to_switch(sw->dev.parent);
+	port = tb_port_at(tb_route(sw), parent_sw);
+	down = tb_find_pcie_down(parent_sw, port);
+	if (!down)
+		return 0;
+
+	tunnel = tb_tunnel_alloc_pci(tb, up, down);
+	if (!tunnel)
+		return -ENOMEM;
+
+	if (tb_tunnel_activate(tunnel)) {
+		tb_port_info(up,
+			     "PCIe tunnel activation failed, aborting\n");
+		tb_tunnel_free(tunnel);
+		return -EIO;
+	}
+
+	list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	return 0;
+}
+
+static int tb_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *nhi_port, *dst_port;
+	struct tb_tunnel *tunnel;
+	struct tb_switch *sw;
+
+	sw = tb_to_switch(xd->dev.parent);
+	dst_port = tb_port_at(xd->route, sw);
+	nhi_port = tb_switch_find_port(tb->root_switch, TB_TYPE_NHI);
+
+	mutex_lock(&tb->lock);
+	tunnel = tb_tunnel_alloc_dma(tb, nhi_port, dst_port, xd->transmit_ring,
+				     xd->transmit_path, xd->receive_ring,
+				     xd->receive_path);
+	if (!tunnel) {
+		mutex_unlock(&tb->lock);
+		return -ENOMEM;
+	}
+
+	if (tb_tunnel_activate(tunnel)) {
+		tb_port_info(nhi_port,
+			     "DMA tunnel activation failed, aborting\n");
+		tb_tunnel_free(tunnel);
+		mutex_unlock(&tb->lock);
+		return -EIO;
+	}
+
+	list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	mutex_unlock(&tb->lock);
+	return 0;
+}
+
+static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
+{
+	struct tb_port *dst_port;
+	struct tb_tunnel *tunnel;
+	struct tb_switch *sw;
+
+	sw = tb_to_switch(xd->dev.parent);
+	dst_port = tb_port_at(xd->route, sw);
+
+	/*
+	 * It is possible that the tunnel was already teared down (in
+	 * case of cable disconnect) so it is fine if we cannot find it
+	 * here anymore.
+	 */
+	tunnel = tb_find_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
+	tb_deactivate_and_free_tunnel(tunnel);
+}
+
+static int tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
+{
+	if (!xd->is_unplugged) {
+		mutex_lock(&tb->lock);
+		__tb_disconnect_xdomain_paths(tb, xd);
+		mutex_unlock(&tb->lock);
+	}
+	return 0;
+}
+
+/* hotplug handling */
+
+/**
+ * tb_handle_hotplug() - handle hotplug event
+ *
+ * Executes on tb->wq.
+ */
+static void tb_handle_hotplug(struct work_struct *work)
+{
+	struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
+	struct tb *tb = ev->tb;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_switch *sw;
+	struct tb_port *port;
+
+	/* Bring the domain back from sleep if it was suspended */
+	pm_runtime_get_sync(&tb->dev);
+
+	mutex_lock(&tb->lock);
+	if (!tcm->hotplug_active)
+		goto out; /* during init, suspend or shutdown */
+
+	sw = tb_switch_find_by_route(tb, ev->route);
+	if (!sw) {
+		tb_warn(tb,
+			"hotplug event from non existent switch %llx:%x (unplug: %d)\n",
+			ev->route, ev->port, ev->unplug);
+		goto out;
+	}
+	if (ev->port > sw->config.max_port_number) {
+		tb_warn(tb,
+			"hotplug event from non existent port %llx:%x (unplug: %d)\n",
+			ev->route, ev->port, ev->unplug);
+		goto put_sw;
+	}
+	port = &sw->ports[ev->port];
+	if (tb_is_upstream_port(port)) {
+		tb_dbg(tb, "hotplug event for upstream port %llx:%x (unplug: %d)\n",
+		       ev->route, ev->port, ev->unplug);
+		goto put_sw;
+	}
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (ev->unplug) {
+		tb_retimer_remove_all(port);
+
+		if (tb_port_has_remote(port)) {
+			tb_port_dbg(port, "switch unplugged\n");
+			tb_sw_set_unplugged(port->remote->sw);
+			tb_free_invalid_tunnels(tb);
+			tb_remove_dp_resources(port->remote->sw);
+			tb_switch_tmu_disable(port->remote->sw);
+			tb_switch_unconfigure_link(port->remote->sw);
+			tb_switch_lane_bonding_disable(port->remote->sw);
+			tb_switch_remove(port->remote->sw);
+			port->remote = NULL;
+			if (port->dual_link_port)
+				port->dual_link_port->remote = NULL;
+			/* Maybe we can create another DP tunnel */
+			tb_tunnel_dp(tb);
+		} else if (port->xdomain) {
+			struct tb_xdomain *xd = tb_xdomain_get(port->xdomain);
+
+			tb_port_dbg(port, "xdomain unplugged\n");
+			/*
+			 * Service drivers are unbound during
+			 * tb_xdomain_remove() so setting XDomain as
+			 * unplugged here prevents deadlock if they call
+			 * tb_xdomain_disable_paths(). We will tear down
+			 * the path below.
+			 */
+			xd->is_unplugged = true;
+			tb_xdomain_remove(xd);
+			port->xdomain = NULL;
+			__tb_disconnect_xdomain_paths(tb, xd);
+			tb_xdomain_put(xd);
+			tb_port_unconfigure_xdomain(port);
+		} else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
+			tb_dp_resource_unavailable(tb, port);
+		} else {
+			tb_port_dbg(port,
+				   "got unplug event for disconnected port, ignoring\n");
+		}
+	} else if (port->remote) {
+		tb_port_dbg(port, "got plug event for connected port, ignoring\n");
+	} else {
+		if (tb_port_is_null(port)) {
+			tb_port_dbg(port, "hotplug: scanning\n");
+			tb_scan_port(port);
+			if (!port->remote)
+				tb_port_dbg(port, "hotplug: no switch found\n");
+		} else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
+			tb_dp_resource_available(tb, port);
+		}
+	}
+
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+put_sw:
+	tb_switch_put(sw);
+out:
+	mutex_unlock(&tb->lock);
+
+	pm_runtime_mark_last_busy(&tb->dev);
+	pm_runtime_put_autosuspend(&tb->dev);
+
+	kfree(ev);
+}
+
+/**
+ * tb_schedule_hotplug_handler() - callback function for the control channel
+ *
+ * Delegates to tb_handle_hotplug.
+ */
+static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
+			    const void *buf, size_t size)
+{
+	const struct cfg_event_pkg *pkg = buf;
+	u64 route;
+
+	if (type != TB_CFG_PKG_EVENT) {
+		tb_warn(tb, "unexpected event %#x, ignoring\n", type);
+		return;
+	}
+
+	route = tb_cfg_get_route(&pkg->header);
+
+	if (tb_cfg_ack_plug(tb->ctl, route, pkg->port, pkg->unplug)) {
+		tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
+			pkg->port);
+	}
+
+	tb_queue_hotplug(tb, route, pkg->port, pkg->unplug);
+}
+
+static void tb_stop(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+	struct tb_tunnel *n;
+
+	cancel_delayed_work(&tcm->remove_work);
+	/* tunnels are only present after everything has been initialized */
+	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
+		/*
+		 * DMA tunnels require the driver to be functional so we
+		 * tear them down. Other protocol tunnels can be left
+		 * intact.
+		 */
+		if (tb_tunnel_is_dma(tunnel))
+			tb_tunnel_deactivate(tunnel);
+		tb_tunnel_free(tunnel);
+	}
+	tb_switch_remove(tb->root_switch);
+	tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
+}
+
+static int tb_scan_finalize_switch(struct device *dev, void *data)
+{
+	if (tb_is_switch(dev)) {
+		struct tb_switch *sw = tb_to_switch(dev);
+
+		/*
+		 * If we found that the switch was already setup by the
+		 * boot firmware, mark it as authorized now before we
+		 * send uevent to userspace.
+		 */
+		if (sw->boot)
+			sw->authorized = 1;
+
+		dev_set_uevent_suppress(dev, false);
+		kobject_uevent(&dev->kobj, KOBJ_ADD);
+		device_for_each_child(dev, NULL, tb_scan_finalize_switch);
+	}
+
+	return 0;
+}
+
+static int tb_start(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	int ret;
+
+	tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
+	if (IS_ERR(tb->root_switch))
+		return PTR_ERR(tb->root_switch);
+
+	/*
+	 * ICM firmware upgrade needs running firmware and in native
+	 * mode that is not available so disable firmware upgrade of the
+	 * root switch.
+	 */
+	tb->root_switch->no_nvm_upgrade = true;
+	/* All USB4 routers support runtime PM */
+	tb->root_switch->rpm = tb_switch_is_usb4(tb->root_switch);
+
+	ret = tb_switch_configure(tb->root_switch);
+	if (ret) {
+		tb_switch_put(tb->root_switch);
+		return ret;
+	}
+
+	/* Announce the switch to the world */
+	ret = tb_switch_add(tb->root_switch);
+	if (ret) {
+		tb_switch_put(tb->root_switch);
+		return ret;
+	}
+
+	/* Enable TMU if it is off */
+	tb_switch_tmu_enable(tb->root_switch);
+	/* Full scan to discover devices added before the driver was loaded. */
+	tb_scan_switch(tb->root_switch);
+	/* Find out tunnels created by the boot firmware */
+	tb_discover_tunnels(tb->root_switch);
+	/*
+	 * If the boot firmware did not create USB 3.x tunnels create them
+	 * now for the whole topology.
+	 */
+	tb_create_usb3_tunnels(tb->root_switch);
+	/* Add DP IN resources for the root switch */
+	tb_add_dp_resources(tb->root_switch);
+	/* Make the discovered switches available to the userspace */
+	device_for_each_child(&tb->root_switch->dev, NULL,
+			      tb_scan_finalize_switch);
+
+	/* Allow tb_handle_hotplug to progress events */
+	tcm->hotplug_active = true;
+	return 0;
+}
+
+static int tb_suspend_noirq(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+
+	tb_dbg(tb, "suspending...\n");
+	tb_disconnect_and_release_dp(tb);
+	tb_switch_suspend(tb->root_switch, false);
+	tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
+	tb_dbg(tb, "suspend finished\n");
+
+	return 0;
+}
+
+static void tb_restore_children(struct tb_switch *sw)
+{
+	struct tb_port *port;
+
+	/* No need to restore if the router is already unplugged */
+	if (sw->is_unplugged)
+		return;
+
+	if (tb_enable_tmu(sw))
+		tb_sw_warn(sw, "failed to restore TMU configuration\n");
+
+	tb_switch_for_each_port(sw, port) {
+		if (!tb_port_has_remote(port) && !port->xdomain)
+			continue;
+
+		if (port->remote) {
+			tb_switch_lane_bonding_enable(port->remote->sw);
+			tb_switch_configure_link(port->remote->sw);
+
+			tb_restore_children(port->remote->sw);
+		} else if (port->xdomain) {
+			tb_port_configure_xdomain(port);
+		}
+	}
+}
+
+static int tb_resume_noirq(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel, *n;
+
+	tb_dbg(tb, "resuming...\n");
+
+	/* remove any pci devices the firmware might have setup */
+	tb_switch_reset(tb->root_switch);
+
+	tb_switch_resume(tb->root_switch);
+	tb_free_invalid_tunnels(tb);
+	tb_free_unplugged_children(tb->root_switch);
+	tb_restore_children(tb->root_switch);
+	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
+		tb_tunnel_restart(tunnel);
+	if (!list_empty(&tcm->tunnel_list)) {
+		/*
+		 * the pcie links need some time to get going.
+		 * 100ms works for me...
+		 */
+		tb_dbg(tb, "tunnels restarted, sleeping for 100ms\n");
+		msleep(100);
+	}
+	 /* Allow tb_handle_hotplug to progress events */
+	tcm->hotplug_active = true;
+	tb_dbg(tb, "resume finished\n");
+
+	return 0;
+}
+
+static int tb_free_unplugged_xdomains(struct tb_switch *sw)
+{
+	struct tb_port *port;
+	int ret = 0;
+
+	tb_switch_for_each_port(sw, port) {
+		if (tb_is_upstream_port(port))
+			continue;
+		if (port->xdomain && port->xdomain->is_unplugged) {
+			tb_retimer_remove_all(port);
+			tb_xdomain_remove(port->xdomain);
+			tb_port_unconfigure_xdomain(port);
+			port->xdomain = NULL;
+			ret++;
+		} else if (port->remote) {
+			ret += tb_free_unplugged_xdomains(port->remote->sw);
+		}
+	}
+
+	return ret;
+}
+
+static int tb_freeze_noirq(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+
+	tcm->hotplug_active = false;
+	return 0;
+}
+
+static int tb_thaw_noirq(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+
+	tcm->hotplug_active = true;
+	return 0;
+}
+
+static void tb_complete(struct tb *tb)
+{
+	/*
+	 * Release any unplugged XDomains and if there is a case where
+	 * another domain is swapped in place of unplugged XDomain we
+	 * need to run another rescan.
+	 */
+	mutex_lock(&tb->lock);
+	if (tb_free_unplugged_xdomains(tb->root_switch))
+		tb_scan_switch(tb->root_switch);
+	mutex_unlock(&tb->lock);
+}
+
+static int tb_runtime_suspend(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+
+	mutex_lock(&tb->lock);
+	tb_switch_suspend(tb->root_switch, true);
+	tcm->hotplug_active = false;
+	mutex_unlock(&tb->lock);
+
+	return 0;
+}
+
+static void tb_remove_work(struct work_struct *work)
+{
+	struct tb_cm *tcm = container_of(work, struct tb_cm, remove_work.work);
+	struct tb *tb = tcm_to_tb(tcm);
+
+	mutex_lock(&tb->lock);
+	if (tb->root_switch) {
+		tb_free_unplugged_children(tb->root_switch);
+		tb_free_unplugged_xdomains(tb->root_switch);
+	}
+	mutex_unlock(&tb->lock);
+}
+
+static int tb_runtime_resume(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel, *n;
+
+	mutex_lock(&tb->lock);
+	tb_switch_resume(tb->root_switch);
+	tb_free_invalid_tunnels(tb);
+	tb_restore_children(tb->root_switch);
+	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
+		tb_tunnel_restart(tunnel);
+	tcm->hotplug_active = true;
+	mutex_unlock(&tb->lock);
+
+	/*
+	 * Schedule cleanup of any unplugged devices. Run this in a
+	 * separate thread to avoid possible deadlock if the device
+	 * removal runtime resumes the unplugged device.
+	 */
+	queue_delayed_work(tb->wq, &tcm->remove_work, msecs_to_jiffies(50));
+	return 0;
+}
+
+static const struct tb_cm_ops tb_cm_ops = {
+	.start = tb_start,
+	.stop = tb_stop,
+	.suspend_noirq = tb_suspend_noirq,
+	.resume_noirq = tb_resume_noirq,
+	.freeze_noirq = tb_freeze_noirq,
+	.thaw_noirq = tb_thaw_noirq,
+	.complete = tb_complete,
+	.runtime_suspend = tb_runtime_suspend,
+	.runtime_resume = tb_runtime_resume,
+	.handle_event = tb_handle_event,
+	.approve_switch = tb_tunnel_pci,
+	.approve_xdomain_paths = tb_approve_xdomain_paths,
+	.disconnect_xdomain_paths = tb_disconnect_xdomain_paths,
+};
+
+struct tb *tb_probe(struct tb_nhi *nhi)
+{
+	struct tb_cm *tcm;
+	struct tb *tb;
+
+	tb = tb_domain_alloc(nhi, sizeof(*tcm));
+	if (!tb)
+		return NULL;
+
+	tb->security_level = TB_SECURITY_USER;
+	tb->cm_ops = &tb_cm_ops;
+
+	tcm = tb_priv(tb);
+	INIT_LIST_HEAD(&tcm->tunnel_list);
+	INIT_LIST_HEAD(&tcm->dp_resources);
+	INIT_DELAYED_WORK(&tcm->remove_work, tb_remove_work);
+
+	return tb;
+}