Merge tag 'thunderbolt-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into char-misc-next

Mika writes:

thunderbolt: Changes for v5.2 merge window

This improves software connection manager on older Apple systems with
Thunderbolt 1 and 2 controller to support full PCIe daisy chains,
Display Port tunneling and P2P networking. There are also fixes for
potential NULL pointer dereferences at various places in the driver.

* tag 'thunderbolt-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt: (44 commits)
  thunderbolt: Make priority unsigned in struct tb_path
  thunderbolt: Start firmware on Titan Ridge Apple systems
  thunderbolt: Reword output of tb_dump_hop()
  thunderbolt: Make rest of the logging to happen at debug level
  thunderbolt: Make __TB_[SW|PORT]_PRINT take const parameters
  thunderbolt: Add support for XDomain connections
  thunderbolt: Make tb_switch_alloc() return ERR_PTR()
  thunderbolt: Add support for DMA tunnels
  thunderbolt: Add XDomain UUID exchange support
  thunderbolt: Run tb_xdp_handle_request() in system workqueue
  thunderbolt: Do not tear down tunnels when driver is unloaded
  thunderbolt: Add support for Display Port tunnels
  thunderbolt: Rework NFC credits handling
  thunderbolt: Generalize port finding routines to support all port types
  thunderbolt: Scan only valid NULL adapter ports in hotplug
  thunderbolt: Add support for full PCIe daisy chains
  thunderbolt: Discover preboot PCIe paths the boot firmware established
  thunderbolt: Deactivate all paths before restarting them
  thunderbolt: Extend tunnel creation to more than 2 adjacent switches
  thunderbolt: Add helper function to iterate from one port to another
  ...

20 files changed, 2765 insertions, 669 deletions

diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c
index c48c3a1eb1f8..fcf31335a8b6 100644
--- a/drivers/net/thunderbolt.c
+++ b/drivers/net/thunderbolt.c
@@ -1282,6 +1282,7 @@ static int __maybe_unused tbnet_suspend(struct device *dev)
 		tbnet_tear_down(net, true);
 	}
 
+	tb_unregister_protocol_handler(&net->handler);
 	return 0;
 }
 
@@ -1290,6 +1291,8 @@ 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);
 
+	tb_register_protocol_handler(&net->handler);
+
 	netif_carrier_off(net->dev);
 	if (netif_running(net->dev)) {
 		netif_device_attach(net->dev);
diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
index f2f0de27252b..833bdee3cec7 100644
--- a/drivers/thunderbolt/Makefile
+++ b/drivers/thunderbolt/Makefile
@@ -1,3 +1,3 @@
 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-objs := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel.o eeprom.o
+thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o lc.o
diff --git a/drivers/thunderbolt/cap.c b/drivers/thunderbolt/cap.c
index 9553305c63ea..8bf8e031f0bc 100644
--- a/drivers/thunderbolt/cap.c
+++ b/drivers/thunderbolt/cap.c
@@ -13,6 +13,7 @@
 
 #define CAP_OFFSET_MAX		0xff
 #define VSE_CAP_OFFSET_MAX	0xffff
+#define TMU_ACCESS_EN		BIT(20)
 
 struct tb_cap_any {
 	union {
@@ -22,28 +23,53 @@ struct tb_cap_any {
 	};
 } __packed;
 
-/**
- * tb_port_find_cap() - Find port capability
- * @port: Port to find the capability for
- * @cap: Capability to look
- *
- * Returns offset to start of capability or %-ENOENT if no such
- * capability was found. Negative errno is returned if there was an
- * error.
- */
-int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
+static int tb_port_enable_tmu(struct tb_port *port, bool enable)
 {
-	u32 offset;
+	struct tb_switch *sw = port->sw;
+	u32 value, offset;
+	int ret;
 
 	/*
-	 * DP out adapters claim to implement TMU capability but in
-	 * reality they do not so we hard code the adapter specific
-	 * capability offset here.
+	 * Legacy devices need to have TMU access enabled before port
+	 * space can be fully accessed.
 	 */
-	if (port->config.type == TB_TYPE_DP_HDMI_OUT)
-		offset = 0x39;
+	if (tb_switch_is_lr(sw))
+		offset = 0x26;
+	else if (tb_switch_is_er(sw))
+		offset = 0x2a;
 	else
-		offset = 0x1;
+		return 0;
+
+	ret = tb_sw_read(sw, &value, TB_CFG_SWITCH, offset, 1);
+	if (ret)
+		return ret;
+
+	if (enable)
+		value |= TMU_ACCESS_EN;
+	else
+		value &= ~TMU_ACCESS_EN;
+
+	return tb_sw_write(sw, &value, TB_CFG_SWITCH, offset, 1);
+}
+
+static void tb_port_dummy_read(struct tb_port *port)
+{
+	/*
+	 * When reading from next capability pointer location in port
+	 * config space the read data is not cleared on LR. To avoid
+	 * reading stale data on next read perform one dummy read after
+	 * port capabilities are walked.
+	 */
+	if (tb_switch_is_lr(port->sw)) {
+		u32 dummy;
+
+		tb_port_read(port, &dummy, TB_CFG_PORT, 0, 1);
+	}
+}
+
+static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
+{
+	u32 offset = 1;
 
 	do {
 		struct tb_cap_any header;
@@ -62,6 +88,31 @@ int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
 	return -ENOENT;
 }
 
+/**
+ * tb_port_find_cap() - Find port capability
+ * @port: Port to find the capability for
+ * @cap: Capability to look
+ *
+ * Returns offset to start of capability or %-ENOENT if no such
+ * capability was found. Negative errno is returned if there was an
+ * error.
+ */
+int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
+{
+	int ret;
+
+	ret = tb_port_enable_tmu(port, true);
+	if (ret)
+		return ret;
+
+	ret = __tb_port_find_cap(port, cap);
+
+	tb_port_dummy_read(port);
+	tb_port_enable_tmu(port, false);
+
+	return ret;
+}
+
 static int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap)
 {
 	int offset = sw->config.first_cap_offset;
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
index 73b386de4d15..2427d73be731 100644
--- a/drivers/thunderbolt/ctl.c
+++ b/drivers/thunderbolt/ctl.c
@@ -720,7 +720,7 @@ int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port,
 		.port = port,
 		.error = error,
 	};
-	tb_ctl_info(ctl, "resetting error on %llx:%x.\n", route, port);
+	tb_ctl_dbg(ctl, "resetting error on %llx:%x.\n", route, port);
 	return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
 }
 
diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index e3fc920af682..f1c10378fa3e 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -42,7 +42,6 @@
 #define ICM_TIMEOUT			5000	/* ms */
 #define ICM_APPROVE_TIMEOUT		10000	/* ms */
 #define ICM_MAX_LINK			4
-#define ICM_MAX_DEPTH			6
 
 /**
  * struct icm - Internal connection manager private data
@@ -469,10 +468,15 @@ static void add_switch(struct tb_switch *parent_sw, u64 route,
 	pm_runtime_get_sync(&parent_sw->dev);
 
 	sw = tb_switch_alloc(parent_sw->tb, &parent_sw->dev, route);
-	if (!sw)
+	if (IS_ERR(sw))
 		goto out;
 
 	sw->uuid = kmemdup(uuid, sizeof(*uuid), GFP_KERNEL);
+	if (!sw->uuid) {
+		tb_sw_warn(sw, "cannot allocate memory for switch\n");
+		tb_switch_put(sw);
+		goto out;
+	}
 	sw->connection_id = connection_id;
 	sw->connection_key = connection_key;
 	sw->link = link;
@@ -709,7 +713,7 @@ icm_fr_device_disconnected(struct tb *tb, const struct icm_pkg_header *hdr)
 	depth = (pkg->link_info & ICM_LINK_INFO_DEPTH_MASK) >>
 		ICM_LINK_INFO_DEPTH_SHIFT;
 
-	if (link > ICM_MAX_LINK || depth > ICM_MAX_DEPTH) {
+	if (link > ICM_MAX_LINK || depth > TB_SWITCH_MAX_DEPTH) {
 		tb_warn(tb, "invalid topology %u.%u, ignoring\n", link, depth);
 		return;
 	}
@@ -739,7 +743,7 @@ icm_fr_xdomain_connected(struct tb *tb, const struct icm_pkg_header *hdr)
 	depth = (pkg->link_info & ICM_LINK_INFO_DEPTH_MASK) >>
 		ICM_LINK_INFO_DEPTH_SHIFT;
 
-	if (link > ICM_MAX_LINK || depth > ICM_MAX_DEPTH) {
+	if (link > ICM_MAX_LINK || depth > TB_SWITCH_MAX_DEPTH) {
 		tb_warn(tb, "invalid topology %u.%u, ignoring\n", link, depth);
 		return;
 	}
@@ -793,9 +797,11 @@ icm_fr_xdomain_connected(struct tb *tb, const struct icm_pkg_header *hdr)
 	 * connected another host to the same port, remove the switch
 	 * first.
 	 */
-	sw = get_switch_at_route(tb->root_switch, route);
-	if (sw)
+	sw = tb_switch_find_by_route(tb, route);
+	if (sw) {
 		remove_switch(sw);
+		tb_switch_put(sw);
+	}
 
 	sw = tb_switch_find_by_link_depth(tb, link, depth);
 	if (!sw) {
@@ -1138,9 +1144,11 @@ icm_tr_xdomain_connected(struct tb *tb, const struct icm_pkg_header *hdr)
 	 * connected another host to the same port, remove the switch
 	 * first.
 	 */
-	sw = get_switch_at_route(tb->root_switch, route);
-	if (sw)
+	sw = tb_switch_find_by_route(tb, route);
+	if (sw) {
 		remove_switch(sw);
+		tb_switch_put(sw);
+	}
 
 	sw = tb_switch_find_by_route(tb, get_parent_route(route));
 	if (!sw) {
@@ -1191,6 +1199,8 @@ static struct pci_dev *get_upstream_port(struct pci_dev *pdev)
 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_BRIDGE:
 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_BRIDGE:
 	case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_BRIDGE:
+	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_BRIDGE:
+	case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_BRIDGE:
 		return parent;
 	}
 
@@ -1560,7 +1570,7 @@ static int icm_firmware_start(struct tb *tb, struct tb_nhi *nhi)
 	if (val & REG_FW_STS_ICM_EN)
 		return 0;
 
-	dev_info(&nhi->pdev->dev, "starting ICM firmware\n");
+	dev_dbg(&nhi->pdev->dev, "starting ICM firmware\n");
 
 	ret = icm_firmware_reset(tb, nhi);
 	if (ret)
@@ -1753,16 +1763,10 @@ static void icm_unplug_children(struct tb_switch *sw)
 	for (i = 1; i <= sw->config.max_port_number; i++) {
 		struct tb_port *port = &sw->ports[i];
 
-		if (tb_is_upstream_port(port))
-			continue;
-		if (port->xdomain) {
+		if (port->xdomain)
 			port->xdomain->is_unplugged = true;
-			continue;
-		}
-		if (!port->remote)
-			continue;
-
-		icm_unplug_children(port->remote->sw);
+		else if (tb_port_has_remote(port))
+			icm_unplug_children(port->remote->sw);
 	}
 }
 
@@ -1773,23 +1777,16 @@ static void icm_free_unplugged_children(struct tb_switch *sw)
 	for (i = 1; i <= sw->config.max_port_number; i++) {
 		struct tb_port *port = &sw->ports[i];
 
-		if (tb_is_upstream_port(port))
-			continue;
-
 		if (port->xdomain && port->xdomain->is_unplugged) {
 			tb_xdomain_remove(port->xdomain);
 			port->xdomain = NULL;
-			continue;
-		}
-
-		if (!port->remote)
-			continue;
-
-		if (port->remote->sw->is_unplugged) {
-			tb_switch_remove(port->remote->sw);
-			port->remote = NULL;
-		} else {
-			icm_free_unplugged_children(port->remote->sw);
+		} else if (tb_port_has_remote(port)) {
+			if (port->remote->sw->is_unplugged) {
+				tb_switch_remove(port->remote->sw);
+				port->remote = NULL;
+			} else {
+				icm_free_unplugged_children(port->remote->sw);
+			}
 		}
 	}
 }
@@ -1853,8 +1850,8 @@ static int icm_start(struct tb *tb)
 		tb->root_switch = tb_switch_alloc_safe_mode(tb, &tb->dev, 0);
 	else
 		tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
-	if (!tb->root_switch)
-		return -ENODEV;
+	if (IS_ERR(tb->root_switch))
+		return PTR_ERR(tb->root_switch);
 
 	/*
 	 * NVM upgrade has not been tested on Apple systems and they
diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
new file mode 100644
index 000000000000..ae1e92611c3e
--- /dev/null
+++ b/drivers/thunderbolt/lc.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt link controller support
+ *
+ * Copyright (C) 2019, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include "tb.h"
+
+/**
+ * tb_lc_read_uuid() - Read switch UUID from link controller common register
+ * @sw: Switch whose UUID is read
+ * @uuid: UUID is placed here
+ */
+int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid)
+{
+	if (!sw->cap_lc)
+		return -EINVAL;
+	return tb_sw_read(sw, uuid, TB_CFG_SWITCH, sw->cap_lc + TB_LC_FUSE, 4);
+}
+
+static int read_lc_desc(struct tb_switch *sw, u32 *desc)
+{
+	if (!sw->cap_lc)
+		return -EINVAL;
+	return tb_sw_read(sw, desc, TB_CFG_SWITCH, sw->cap_lc + TB_LC_DESC, 1);
+}
+
+static int find_port_lc_cap(struct tb_port *port)
+{
+	struct tb_switch *sw = port->sw;
+	int start, phys, ret, size;
+	u32 desc;
+
+	ret = read_lc_desc(sw, &desc);
+	if (ret)
+		return ret;
+
+	/* Start of port LC registers */
+	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
+	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
+	phys = tb_phy_port_from_link(port->port);
+
+	return sw->cap_lc + start + phys * size;
+}
+
+static int tb_lc_configure_lane(struct tb_port *port, bool configure)
+{
+	bool upstream = tb_is_upstream_port(port);
+	struct tb_switch *sw = port->sw;
+	u32 ctrl, lane;
+	int cap, ret;
+
+	if (sw->generation < 2)
+		return 0;
+
+	cap = find_port_lc_cap(port);
+	if (cap < 0)
+		return cap;
+
+	ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
+	if (ret)
+		return ret;
+
+	/* Resolve correct lane */
+	if (port->port % 2)
+		lane = TB_LC_SX_CTRL_L1C;
+	else
+		lane = TB_LC_SX_CTRL_L2C;
+
+	if (configure) {
+		ctrl |= lane;
+		if (upstream)
+			ctrl |= TB_LC_SX_CTRL_UPSTREAM;
+	} else {
+		ctrl &= ~lane;
+		if (upstream)
+			ctrl &= ~TB_LC_SX_CTRL_UPSTREAM;
+	}
+
+	return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
+}
+
+/**
+ * tb_lc_configure_link() - Let LC know about configured link
+ * @sw: Switch that is being added
+ *
+ * Informs LC of both parent switch and @sw that there is established
+ * link between the two.
+ */
+int tb_lc_configure_link(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+	int ret;
+
+	if (!sw->config.enabled || !tb_route(sw))
+		return 0;
+
+	up = tb_upstream_port(sw);
+	down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
+
+	/* Configure parent link toward this switch */
+	ret = tb_lc_configure_lane(down, true);
+	if (ret)
+		return ret;
+
+	/* Configure upstream link from this switch to the parent */
+	ret = tb_lc_configure_lane(up, true);
+	if (ret)
+		tb_lc_configure_lane(down, false);
+
+	return ret;
+}
+
+/**
+ * tb_lc_unconfigure_link() - Let LC know about unconfigured link
+ * @sw: Switch to unconfigure
+ *
+ * Informs LC of both parent switch and @sw that the link between the
+ * two does not exist anymore.
+ */
+void tb_lc_unconfigure_link(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+
+	if (sw->is_unplugged || !sw->config.enabled || !tb_route(sw))
+		return;
+
+	up = tb_upstream_port(sw);
+	down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
+
+	tb_lc_configure_lane(up, false);
+	tb_lc_configure_lane(down, false);
+}
+
+/**
+ * tb_lc_set_sleep() - Inform LC that the switch is going to sleep
+ * @sw: Switch to set sleep
+ *
+ * Let the switch link controllers know that the switch is going to
+ * sleep.
+ */
+int tb_lc_set_sleep(struct tb_switch *sw)
+{
+	int start, size, nlc, ret, i;
+	u32 desc;
+
+	if (sw->generation < 2)
+		return 0;
+
+	ret = read_lc_desc(sw, &desc);
+	if (ret)
+		return ret;
+
+	/* Figure out number of link controllers */
+	nlc = desc & TB_LC_DESC_NLC_MASK;
+	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
+	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
+
+	/* For each link controller set sleep bit */
+	for (i = 0; i < nlc; i++) {
+		unsigned int offset = sw->cap_lc + start + i * size;
+		u32 ctrl;
+
+		ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
+				 offset + TB_LC_SX_CTRL, 1);
+		if (ret)
+			return ret;
+
+		ctrl |= TB_LC_SX_CTRL_SLP;
+		ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH,
+				  offset + TB_LC_SX_CTRL, 1);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 9aa44f9762a3..cac1ead5e302 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -27,8 +27,7 @@
  * use this ring for anything else.
  */
 #define RING_E2E_UNUSED_HOPID	2
-/* HopIDs 0-7 are reserved by the Thunderbolt protocol */
-#define RING_FIRST_USABLE_HOPID	8
+#define RING_FIRST_USABLE_HOPID	TB_PATH_MIN_HOPID
 
 /*
  * Minimal number of vectors when we use MSI-X. Two for control channel
diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index a11956522bac..afe5f8391ebf 100644
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -1,62 +1,330 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Thunderbolt Cactus Ridge driver - path/tunnel functionality
+ * Thunderbolt driver - path/tunnel functionality
  *
  * 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/ktime.h>
 
 #include "tb.h"
 
-
-static void tb_dump_hop(struct tb_port *port, struct tb_regs_hop *hop)
+static void tb_dump_hop(const struct tb_path_hop *hop, const struct tb_regs_hop *regs)
 {
-	tb_port_dbg(port, " Hop through port %d to hop %d (%s)\n",
-		    hop->out_port, hop->next_hop,
-		    hop->enable ? "enabled" : "disabled");
+	const struct tb_port *port = hop->in_port;
+
+	tb_port_dbg(port, " In HopID: %d => Out port: %d Out HopID: %d\n",
+		    hop->in_hop_index, regs->out_port, regs->next_hop);
 	tb_port_dbg(port, "  Weight: %d Priority: %d Credits: %d Drop: %d\n",
-		    hop->weight, hop->priority,
-		    hop->initial_credits, hop->drop_packages);
+		    regs->weight, regs->priority,
+		    regs->initial_credits, regs->drop_packages);
 	tb_port_dbg(port, "   Counter enabled: %d Counter index: %d\n",
-		    hop->counter_enable, hop->counter);
+		    regs->counter_enable, regs->counter);
 	tb_port_dbg(port, "  Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n",
-		    hop->ingress_fc, hop->egress_fc,
-		    hop->ingress_shared_buffer, hop->egress_shared_buffer);
+		    regs->ingress_fc, regs->egress_fc,
+		    regs->ingress_shared_buffer, regs->egress_shared_buffer);
 	tb_port_dbg(port, "  Unknown1: %#x Unknown2: %#x Unknown3: %#x\n",
-		    hop->unknown1, hop->unknown2, hop->unknown3);
+		    regs->unknown1, regs->unknown2, regs->unknown3);
+}
+
+static struct tb_port *tb_path_find_dst_port(struct tb_port *src, int src_hopid,
+					     int dst_hopid)
+{
+	struct tb_port *port, *out_port = NULL;
+	struct tb_regs_hop hop;
+	struct tb_switch *sw;
+	int i, ret, hopid;
+
+	hopid = src_hopid;
+	port = src;
+
+	for (i = 0; port && i < TB_PATH_MAX_HOPS; i++) {
+		sw = port->sw;
+
+		ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hopid, 2);
+		if (ret) {
+			tb_port_warn(port, "failed to read path at %d\n", hopid);
+			return NULL;
+		}
+
+		if (!hop.enable)
+			return NULL;
+
+		out_port = &sw->ports[hop.out_port];
+		hopid = hop.next_hop;
+		port = out_port->remote;
+	}
+
+	return out_port && hopid == dst_hopid ? out_port : NULL;
+}
+
+static int tb_path_find_src_hopid(struct tb_port *src,
+	const struct tb_port *dst, int dst_hopid)
+{
+	struct tb_port *out;
+	int i;
+
+	for (i = TB_PATH_MIN_HOPID; i <= src->config.max_in_hop_id; i++) {
+		out = tb_path_find_dst_port(src, i, dst_hopid);
+		if (out == dst)
+			return i;
+	}
+
+	return 0;
+}
+
+/**
+ * tb_path_discover() - Discover a path
+ * @src: First input port of a path
+ * @src_hopid: Starting HopID of a path (%-1 if don't care)
+ * @dst: Expected destination port of the path (%NULL if don't care)
+ * @dst_hopid: HopID to the @dst (%-1 if don't care)
+ * @last: Last port is filled here if not %NULL
+ * @name: Name of the path
+ *
+ * Follows a path starting from @src and @src_hopid to the last output
+ * port of the path. Allocates HopIDs for the visited ports. Call
+ * tb_path_free() to release the path and allocated HopIDs when the path
+ * is not needed anymore.
+ *
+ * Note function discovers also incomplete paths so caller should check
+ * that the @dst port is the expected one. If it is not, the path can be
+ * cleaned up by calling tb_path_deactivate() before tb_path_free().
+ *
+ * Return: Discovered path on success, %NULL in case of failure
+ */
+struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
+				 struct tb_port *dst, int dst_hopid,
+				 struct tb_port **last, const char *name)
+{
+	struct tb_port *out_port;
+	struct tb_regs_hop hop;
+	struct tb_path *path;
+	struct tb_switch *sw;
+	struct tb_port *p;
+	size_t num_hops;
+	int ret, i, h;
+
+	if (src_hopid < 0 && dst) {
+		/*
+		 * For incomplete paths the intermediate HopID can be
+		 * different from the one used by the protocol adapter
+		 * so in that case find a path that ends on @dst with
+		 * matching @dst_hopid. That should give us the correct
+		 * HopID for the @src.
+		 */
+		src_hopid = tb_path_find_src_hopid(src, dst, dst_hopid);
+		if (!src_hopid)
+			return NULL;
+	}
+
+	p = src;
+	h = src_hopid;
+	num_hops = 0;
+
+	for (i = 0; p && i < TB_PATH_MAX_HOPS; i++) {
+		sw = p->sw;
+
+		ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2);
+		if (ret) {
+			tb_port_warn(p, "failed to read path at %d\n", h);
+			return NULL;
+		}
+
+		/* If the hop is not enabled we got an incomplete path */
+		if (!hop.enable)
+			break;
+
+		out_port = &sw->ports[hop.out_port];
+		if (last)
+			*last = out_port;
+
+		h = hop.next_hop;
+		p = out_port->remote;
+		num_hops++;
+	}
+
+	path = kzalloc(sizeof(*path), GFP_KERNEL);
+	if (!path)
+		return NULL;
+
+	path->name = name;
+	path->tb = src->sw->tb;
+	path->path_length = num_hops;
+	path->activated = true;
+
+	path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
+	if (!path->hops) {
+		kfree(path);
+		return NULL;
+	}
+
+	p = src;
+	h = src_hopid;
+
+	for (i = 0; i < num_hops; i++) {
+		int next_hop;
+
+		sw = p->sw;
+
+		ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2);
+		if (ret) {
+			tb_port_warn(p, "failed to read path at %d\n", h);
+			goto err;
+		}
+
+		if (tb_port_alloc_in_hopid(p, h, h) < 0)
+			goto err;
+
+		out_port = &sw->ports[hop.out_port];
+		next_hop = hop.next_hop;
+
+		if (tb_port_alloc_out_hopid(out_port, next_hop, next_hop) < 0) {
+			tb_port_release_in_hopid(p, h);
+			goto err;
+		}
+
+		path->hops[i].in_port = p;
+		path->hops[i].in_hop_index = h;
+		path->hops[i].in_counter_index = -1;
+		path->hops[i].out_port = out_port;
+		path->hops[i].next_hop_index = next_hop;
+
+		h = next_hop;
+		p = out_port->remote;
+	}
+
+	return path;
+
+err:
+	tb_port_warn(src, "failed to discover path starting at HopID %d\n",
+		     src_hopid);
+	tb_path_free(path);
+	return NULL;
 }
 
 /**
- * tb_path_alloc() - allocate a thunderbolt path
+ * tb_path_alloc() - allocate a thunderbolt path between two ports
+ * @tb: Domain pointer
+ * @src: Source port of the path
+ * @src_hopid: HopID used for the first ingress port in the path
+ * @dst: Destination port of the path
+ * @dst_hopid: HopID used for the last egress port in the path
+ * @link_nr: Preferred link if there are dual links on the path
+ * @name: Name of the path
+ *
+ * Creates path between two ports starting with given @src_hopid. Reserves
+ * HopIDs for each port (they can be different from @src_hopid depending on
+ * how many HopIDs each port already have reserved). If there are dual
+ * links on the path, prioritizes using @link_nr.
  *
  * Return: Returns a tb_path on success or NULL on failure.
  */
-struct tb_path *tb_path_alloc(struct tb *tb, int num_hops)
+struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
+			      struct tb_port *dst, int dst_hopid, int link_nr,
+			      const char *name)
 {
-	struct tb_path *path = kzalloc(sizeof(*path), GFP_KERNEL);
+	struct tb_port *in_port, *out_port;
+	int in_hopid, out_hopid;
+	struct tb_path *path;
+	size_t num_hops;
+	int i, ret;
+
+	path = kzalloc(sizeof(*path), GFP_KERNEL);
 	if (!path)
 		return NULL;
+
+	/*
+	 * Number of hops on a path is the distance between the two
+	 * switches plus the source adapter port.
+	 */
+	num_hops = abs(tb_route_length(tb_route(src->sw)) -
+		       tb_route_length(tb_route(dst->sw))) + 1;
+
 	path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
 	if (!path->hops) {
 		kfree(path);
 		return NULL;
 	}
+
+	in_hopid = src_hopid;
+	out_port = NULL;
+
+	for (i = 0; i < num_hops; i++) {
+		in_port = tb_next_port_on_path(src, dst, out_port);
+		if (!in_port)
+			goto err;
+
+		if (in_port->dual_link_port && in_port->link_nr != link_nr)
+			in_port = in_port->dual_link_port;
+
+		ret = tb_port_alloc_in_hopid(in_port, in_hopid, in_hopid);
+		if (ret < 0)
+			goto err;
+		in_hopid = ret;
+
+		out_port = tb_next_port_on_path(src, dst, in_port);
+		if (!out_port)
+			goto err;
+
+		if (out_port->dual_link_port && out_port->link_nr != link_nr)
+			out_port = out_port->dual_link_port;
+
+		if (i == num_hops - 1)
+			ret = tb_port_alloc_out_hopid(out_port, dst_hopid,
+						      dst_hopid);
+		else
+			ret = tb_port_alloc_out_hopid(out_port, -1, -1);
+
+		if (ret < 0)
+			goto err;
+		out_hopid = ret;
+
+		path->hops[i].in_hop_index = in_hopid;
+		path->hops[i].in_port = in_port;
+		path->hops[i].in_counter_index = -1;
+		path->hops[i].out_port = out_port;
+		path->hops[i].next_hop_index = out_hopid;
+
+		in_hopid = out_hopid;
+	}
+
 	path->tb = tb;
 	path->path_length = num_hops;
+	path->name = name;
+
 	return path;
+
+err:
+	tb_path_free(path);
+	return NULL;
 }
 
 /**
- * tb_path_free() - free a deactivated path
+ * tb_path_free() - free a path
+ * @path: Path to free
+ *
+ * Frees a path. The path does not need to be deactivated.
  */
 void tb_path_free(struct tb_path *path)
 {
-	if (path->activated) {
-		tb_WARN(path->tb, "trying to free an activated path\n")
-		return;
+	int i;
+
+	for (i = 0; i < path->path_length; i++) {
+		const struct tb_path_hop *hop = &path->hops[i];
+
+		if (hop->in_port)
+			tb_port_release_in_hopid(hop->in_port,
+						 hop->in_hop_index);
+		if (hop->out_port)
+			tb_port_release_out_hopid(hop->out_port,
+						  hop->next_hop_index);
 	}
+
 	kfree(path->hops);
 	kfree(path);
 }
@@ -74,14 +342,65 @@ static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop)
 	}
 }
 
+static int __tb_path_deactivate_hop(struct tb_port *port, int hop_index,
+				    bool clear_fc)
+{
+	struct tb_regs_hop hop;
+	ktime_t timeout;
+	int ret;
+
+	/* Disable the path */
+	ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
+	if (ret)
+		return ret;
+
+	/* Already disabled */
+	if (!hop.enable)
+		return 0;
+
+	hop.enable = 0;
+
+	ret = tb_port_write(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
+	if (ret)
+		return ret;
+
+	/* Wait until it is drained */
+	timeout = ktime_add_ms(ktime_get(), 500);
+	do {
+		ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
+		if (ret)
+			return ret;
+
+		if (!hop.pending) {
+			if (clear_fc) {
+				/* Clear flow control */
+				hop.ingress_fc = 0;
+				hop.egress_fc = 0;
+				hop.ingress_shared_buffer = 0;
+				hop.egress_shared_buffer = 0;
+
+				return tb_port_write(port, &hop, TB_CFG_HOPS,
+						     2 * hop_index, 2);
+			}
+
+			return 0;
+		}
+
+		usleep_range(10, 20);
+	} while (ktime_before(ktime_get(), timeout));
+
+	return -ETIMEDOUT;
+}
+
 static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop)
 {
 	int i, res;
-	struct tb_regs_hop hop = { };
+
 	for (i = first_hop; i < path->path_length; i++) {
-		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
-				    2 * path->hops[i].in_hop_index, 2);
-		if (res)
+		res = __tb_path_deactivate_hop(path->hops[i].in_port,
+					       path->hops[i].in_hop_index,
+					       path->clear_fc);
+		if (res && res != -ENODEV)
 			tb_port_warn(path->hops[i].in_port,
 				     "hop deactivation failed for hop %d, index %d\n",
 				     i, path->hops[i].in_hop_index);
@@ -94,12 +413,12 @@ void tb_path_deactivate(struct tb_path *path)
 		tb_WARN(path->tb, "trying to deactivate an inactive path\n");
 		return;
 	}
-	tb_info(path->tb,
-		"deactivating path from %llx:%x to %llx:%x\n",
-		tb_route(path->hops[0].in_port->sw),
-		path->hops[0].in_port->port,
-		tb_route(path->hops[path->path_length - 1].out_port->sw),
-		path->hops[path->path_length - 1].out_port->port);
+	tb_dbg(path->tb,
+	       "deactivating %s path from %llx:%x to %llx:%x\n",
+	       path->name, tb_route(path->hops[0].in_port->sw),
+	       path->hops[0].in_port->port,
+	       tb_route(path->hops[path->path_length - 1].out_port->sw),
+	       path->hops[path->path_length - 1].out_port->port);
 	__tb_path_deactivate_hops(path, 0);
 	__tb_path_deallocate_nfc(path, 0);
 	path->activated = false;
@@ -122,12 +441,12 @@ int tb_path_activate(struct tb_path *path)
 		return -EINVAL;
 	}
 
-	tb_info(path->tb,
-		"activating path from %llx:%x to %llx:%x\n",
-		tb_route(path->hops[0].in_port->sw),
-		path->hops[0].in_port->port,
-		tb_route(path->hops[path->path_length - 1].out_port->sw),
-		path->hops[path->path_length - 1].out_port->port);
+	tb_dbg(path->tb,
+	       "activating %s path from %llx:%x to %llx:%x\n",
+	       path->name, tb_route(path->hops[0].in_port->sw),
+	       path->hops[0].in_port->port,
+	       tb_route(path->hops[path->path_length - 1].out_port->sw),
+	       path->hops[path->path_length - 1].out_port->port);
 
 	/* Clear counters. */
 	for (i = path->path_length - 1; i >= 0; i--) {
@@ -153,30 +472,14 @@ int tb_path_activate(struct tb_path *path)
 	for (i = path->path_length - 1; i >= 0; i--) {
 		struct tb_regs_hop hop = { 0 };
 
-		/*
-		 * We do (currently) not tear down paths setup by the firmeware.
-		 * If a firmware device is unplugged and plugged in again then
-		 * it can happen that we reuse some of the hops from the (now
-		 * defunct) firmeware path. This causes the hotplug operation to
-		 * fail (the pci device does not show up). Clearing the hop
-		 * before overwriting it fixes the problem.
-		 *
-		 * Should be removed once we discover and tear down firmeware
-		 * paths.
-		 */
-		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
-				    2 * path->hops[i].in_hop_index, 2);
-		if (res) {
-			__tb_path_deactivate_hops(path, i);
-			__tb_path_deallocate_nfc(path, 0);
-			goto err;
-		}
+		/* If it is left active deactivate it first */
+		__tb_path_deactivate_hop(path->hops[i].in_port,
+				path->hops[i].in_hop_index, path->clear_fc);
 
 		/* dword 0 */
 		hop.next_hop = path->hops[i].next_hop_index;
 		hop.out_port = path->hops[i].out_port->port;
-		/* TODO: figure out why these are good values */
-		hop.initial_credits = (i == path->path_length - 1) ? 16 : 7;
+		hop.initial_credits = path->hops[i].initial_credits;
 		hop.unknown1 = 0;
 		hop.enable = 1;
 
@@ -198,9 +501,8 @@ int tb_path_activate(struct tb_path *path)
 					    & out_mask;
 		hop.unknown3 = 0;
 
-		tb_port_info(path->hops[i].in_port, "Writing hop %d, index %d",
-			     i, path->hops[i].in_hop_index);
-		tb_dump_hop(path->hops[i].in_port, &hop);
+		tb_port_dbg(path->hops[i].in_port, "Writing hop %d\n", i);
+		tb_dump_hop(&path->hops[i], &hop);
 		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
 				    2 * path->hops[i].in_hop_index, 2);
 		if (res) {
@@ -210,7 +512,7 @@ int tb_path_activate(struct tb_path *path)
 		}
 	}
 	path->activated = true;
-	tb_info(path->tb, "path activation complete\n");
+	tb_dbg(path->tb, "path activation complete\n");
 	return 0;
 err:
 	tb_WARN(path->tb, "path activation failed\n");
diff --git a/drivers/thunderbolt/property.c b/drivers/thunderbolt/property.c
index b2f0d6386cee..d5b0cdb8f0b1 100644
--- a/drivers/thunderbolt/property.c
+++ b/drivers/thunderbolt/property.c
@@ -176,6 +176,10 @@ static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
 	} else {
 		dir->uuid = kmemdup(&block[dir_offset], sizeof(*dir->uuid),
 				    GFP_KERNEL);
+		if (!dir->uuid) {
+			tb_property_free_dir(dir);
+			return NULL;
+		}
 		content_offset = dir_offset + 4;
 		content_len = dir_len - 4; /* Length includes UUID */
 	}
@@ -548,6 +552,11 @@ int tb_property_add_data(struct tb_property_dir *parent, const char *key,
 
 	property->length = size / 4;
 	property->value.data = kzalloc(size, GFP_KERNEL);
+	if (!property->value.data) {
+		kfree(property);
+		return -ENOMEM;
+	}
+
 	memcpy(property->value.data, buf, buflen);
 
 	list_add_tail(&property->list, &parent->properties);
@@ -578,7 +587,12 @@ int tb_property_add_text(struct tb_property_dir *parent, const char *key,
 		return -ENOMEM;
 
 	property->length = size / 4;
-	property->value.data = kzalloc(size, GFP_KERNEL);
+	property->value.text = kzalloc(size, GFP_KERNEL);
+	if (!property->value.text) {
+		kfree(property);
+		return -ENOMEM;
+	}
+
 	strcpy(property->value.text, text);
 
 	list_add_tail(&property->list, &parent->properties);
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index cd96994dc094..c1b016574fb4 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -10,15 +10,13 @@
 #include <linux/idr.h>
 #include <linux/nvmem-provider.h>
 #include <linux/pm_runtime.h>
+#include <linux/sched/signal.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
 #include "tb.h"
 
-/* Switch authorization from userspace is serialized by this lock */
-static DEFINE_MUTEX(switch_lock);
-
 /* Switch NVM support */
 
 #define NVM_DEVID		0x05
@@ -254,8 +252,8 @@ static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
 	struct tb_switch *sw = priv;
 	int ret = 0;
 
-	if (mutex_lock_interruptible(&switch_lock))
-		return -ERESTARTSYS;
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
 
 	/*
 	 * Since writing the NVM image might require some special steps,
@@ -275,7 +273,7 @@ static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
 	memcpy(sw->nvm->buf + offset, val, bytes);
 
 unlock:
-	mutex_unlock(&switch_lock);
+	mutex_unlock(&sw->tb->lock);
 
 	return ret;
 }
@@ -364,10 +362,7 @@ static int tb_switch_nvm_add(struct tb_switch *sw)
 	}
 	nvm->non_active = nvm_dev;
 
-	mutex_lock(&switch_lock);
 	sw->nvm = nvm;
-	mutex_unlock(&switch_lock);
-
 	return 0;
 
 err_nvm_active:
@@ -384,10 +379,8 @@ static void tb_switch_nvm_remove(struct tb_switch *sw)
 {
 	struct tb_switch_nvm *nvm;
 
-	mutex_lock(&switch_lock);
 	nvm = sw->nvm;
 	sw->nvm = NULL;
-	mutex_unlock(&switch_lock);
 
 	if (!nvm)
 		return;
@@ -500,23 +493,22 @@ int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
 		if (state < 0)
 			return state;
 		if (state == TB_PORT_DISABLED) {
-			tb_port_info(port, "is disabled (state: 0)\n");
+			tb_port_dbg(port, "is disabled (state: 0)\n");
 			return 0;
 		}
 		if (state == TB_PORT_UNPLUGGED) {
 			if (wait_if_unplugged) {
 				/* used during resume */
-				tb_port_info(port,
-					     "is unplugged (state: 7), retrying...\n");
+				tb_port_dbg(port,
+					    "is unplugged (state: 7), retrying...\n");
 				msleep(100);
 				continue;
 			}
-			tb_port_info(port, "is unplugged (state: 7)\n");
+			tb_port_dbg(port, "is unplugged (state: 7)\n");
 			return 0;
 		}
 		if (state == TB_PORT_UP) {
-			tb_port_info(port,
-				     "is connected, link is up (state: 2)\n");
+			tb_port_dbg(port, "is connected, link is up (state: 2)\n");
 			return 1;
 		}
 
@@ -524,9 +516,9 @@ int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
 		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
 		 * time.
 		 */
-		tb_port_info(port,
-			     "is connected, link is not up (state: %d), retrying...\n",
-			     state);
+		tb_port_dbg(port,
+			    "is connected, link is not up (state: %d), retrying...\n",
+			    state);
 		msleep(100);
 	}
 	tb_port_warn(port,
@@ -544,19 +536,47 @@ int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
  */
 int tb_port_add_nfc_credits(struct tb_port *port, int credits)
 {
-	if (credits == 0)
+	u32 nfc_credits;
+
+	if (credits == 0 || port->sw->is_unplugged)
 		return 0;
-	tb_port_info(port,
-		     "adding %#x NFC credits (%#x -> %#x)",
-		     credits,
-		     port->config.nfc_credits,
-		     port->config.nfc_credits + credits);
-	port->config.nfc_credits += credits;
+
+	nfc_credits = port->config.nfc_credits & TB_PORT_NFC_CREDITS_MASK;
+	nfc_credits += credits;
+
+	tb_port_dbg(port, "adding %d NFC credits to %lu",
+		    credits, port->config.nfc_credits & TB_PORT_NFC_CREDITS_MASK);
+
+	port->config.nfc_credits &= ~TB_PORT_NFC_CREDITS_MASK;
+	port->config.nfc_credits |= nfc_credits;
+
 	return tb_port_write(port, &port->config.nfc_credits,
 			     TB_CFG_PORT, 4, 1);
 }
 
 /**
+ * tb_port_set_initial_credits() - Set initial port link credits allocated
+ * @port: Port to set the initial credits
+ * @credits: Number of credits to to allocate
+ *
+ * Set initial credits value to be used for ingress shared buffering.
+ */
+int tb_port_set_initial_credits(struct tb_port *port, u32 credits)
+{
+	u32 data;
+	int ret;
+
+	ret = tb_port_read(port, &data, TB_CFG_PORT, 5, 1);
+	if (ret)
+		return ret;
+
+	data &= ~TB_PORT_LCA_MASK;
+	data |= (credits << TB_PORT_LCA_SHIFT) & TB_PORT_LCA_MASK;
+
+	return tb_port_write(port, &data, TB_CFG_PORT, 5, 1);
+}
+
+/**
  * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
  *
  * Return: Returns 0 on success or an error code on failure.
@@ -564,7 +584,7 @@ int tb_port_add_nfc_credits(struct tb_port *port, int credits)
 int tb_port_clear_counter(struct tb_port *port, int counter)
 {
 	u32 zero[3] = { 0, 0, 0 };
-	tb_port_info(port, "clearing counter %d\n", counter);
+	tb_port_dbg(port, "clearing counter %d\n", counter);
 	return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
 }
 
@@ -593,15 +613,304 @@ static int tb_init_port(struct tb_port *port)
 			port->cap_phy = cap;
 		else
 			tb_port_WARN(port, "non switch port without a PHY\n");
+	} else if (port->port != 0) {
+		cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
+		if (cap > 0)
+			port->cap_adap = cap;
 	}
 
 	tb_dump_port(port->sw->tb, &port->config);
 
-	/* TODO: Read dual link port, DP port and more from EEPROM. */
+	/* Control port does not need HopID allocation */
+	if (port->port) {
+		ida_init(&port->in_hopids);
+		ida_init(&port->out_hopids);
+	}
+
 	return 0;
 
 }
 
+static int tb_port_alloc_hopid(struct tb_port *port, bool in, int min_hopid,
+			       int max_hopid)
+{
+	int port_max_hopid;
+	struct ida *ida;
+
+	if (in) {
+		port_max_hopid = port->config.max_in_hop_id;
+		ida = &port->in_hopids;
+	} else {
+		port_max_hopid = port->config.max_out_hop_id;
+		ida = &port->out_hopids;
+	}
+
+	/* HopIDs 0-7 are reserved */
+	if (min_hopid < TB_PATH_MIN_HOPID)
+		min_hopid = TB_PATH_MIN_HOPID;
+
+	if (max_hopid < 0 || max_hopid > port_max_hopid)
+		max_hopid = port_max_hopid;
+
+	return ida_simple_get(ida, min_hopid, max_hopid + 1, GFP_KERNEL);
+}
+
+/**
+ * tb_port_alloc_in_hopid() - Allocate input HopID from port
+ * @port: Port to allocate HopID for
+ * @min_hopid: Minimum acceptable input HopID
+ * @max_hopid: Maximum acceptable input HopID
+ *
+ * Return: HopID between @min_hopid and @max_hopid or negative errno in
+ * case of error.
+ */
+int tb_port_alloc_in_hopid(struct tb_port *port, int min_hopid, int max_hopid)
+{
+	return tb_port_alloc_hopid(port, true, min_hopid, max_hopid);
+}
+
+/**
+ * tb_port_alloc_out_hopid() - Allocate output HopID from port
+ * @port: Port to allocate HopID for
+ * @min_hopid: Minimum acceptable output HopID
+ * @max_hopid: Maximum acceptable output HopID
+ *
+ * Return: HopID between @min_hopid and @max_hopid or negative errno in
+ * case of error.
+ */
+int tb_port_alloc_out_hopid(struct tb_port *port, int min_hopid, int max_hopid)
+{
+	return tb_port_alloc_hopid(port, false, min_hopid, max_hopid);
+}
+
+/**
+ * tb_port_release_in_hopid() - Release allocated input HopID from port
+ * @port: Port whose HopID to release
+ * @hopid: HopID to release
+ */
+void tb_port_release_in_hopid(struct tb_port *port, int hopid)
+{
+	ida_simple_remove(&port->in_hopids, hopid);
+}
+
+/**
+ * tb_port_release_out_hopid() - Release allocated output HopID from port
+ * @port: Port whose HopID to release
+ * @hopid: HopID to release
+ */
+void tb_port_release_out_hopid(struct tb_port *port, int hopid)
+{
+	ida_simple_remove(&port->out_hopids, hopid);
+}
+
+/**
+ * tb_next_port_on_path() - Return next port for given port on a path
+ * @start: Start port of the walk
+ * @end: End port of the walk
+ * @prev: Previous port (%NULL if this is the first)
+ *
+ * This function can be used to walk from one port to another if they
+ * are connected through zero or more switches. If the @prev is dual
+ * link port, the function follows that link and returns another end on
+ * that same link.
+ *
+ * If the @end port has been reached, return %NULL.
+ *
+ * Domain tb->lock must be held when this function is called.
+ */
+struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
+				     struct tb_port *prev)
+{
+	struct tb_port *next;
+
+	if (!prev)
+		return start;
+
+	if (prev->sw == end->sw) {
+		if (prev == end)
+			return NULL;
+		return end;
+	}
+
+	if (start->sw->config.depth < end->sw->config.depth) {
+		if (prev->remote &&
+		    prev->remote->sw->config.depth > prev->sw->config.depth)
+			next = prev->remote;
+		else
+			next = tb_port_at(tb_route(end->sw), prev->sw);
+	} else {
+		if (tb_is_upstream_port(prev)) {
+			next = prev->remote;
+		} else {
+			next = tb_upstream_port(prev->sw);
+			/*
+			 * Keep the same link if prev and next are both
+			 * dual link ports.
+			 */
+			if (next->dual_link_port &&
+			    next->link_nr != prev->link_nr) {
+				next = next->dual_link_port;
+			}
+		}
+	}
+
+	return next;
+}
+
+/**
+ * tb_port_is_enabled() - Is the adapter port enabled
+ * @port: Port to check
+ */
+bool tb_port_is_enabled(struct tb_port *port)
+{
+	switch (port->config.type) {
+	case TB_TYPE_PCIE_UP:
+	case TB_TYPE_PCIE_DOWN:
+		return tb_pci_port_is_enabled(port);
+
+	case TB_TYPE_DP_HDMI_IN:
+	case TB_TYPE_DP_HDMI_OUT:
+		return tb_dp_port_is_enabled(port);
+
+	default:
+		return false;
+	}
+}
+
+/**
+ * tb_pci_port_is_enabled() - Is the PCIe adapter port enabled
+ * @port: PCIe port to check
+ */
+bool tb_pci_port_is_enabled(struct tb_port *port)
+{
+	u32 data;
+
+	if (tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap, 1))
+		return false;
+
+	return !!(data & TB_PCI_EN);
+}
+
+/**
+ * tb_pci_port_enable() - Enable PCIe adapter port
+ * @port: PCIe port to enable
+ * @enable: Enable/disable the PCIe adapter
+ */
+int tb_pci_port_enable(struct tb_port *port, bool enable)
+{
+	u32 word = enable ? TB_PCI_EN : 0x0;
+	if (!port->cap_adap)
+		return -ENXIO;
+	return tb_port_write(port, &word, TB_CFG_PORT, port->cap_adap, 1);
+}
+
+/**
+ * tb_dp_port_hpd_is_active() - Is HPD already active
+ * @port: DP out port to check
+ *
+ * Checks if the DP OUT adapter port has HDP bit already set.
+ */
+int tb_dp_port_hpd_is_active(struct tb_port *port)
+{
+	u32 data;
+	int ret;
+
+	ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap + 2, 1);
+	if (ret)
+		return ret;
+
+	return !!(data & TB_DP_HDP);
+}
+
+/**
+ * tb_dp_port_hpd_clear() - Clear HPD from DP IN port
+ * @port: Port to clear HPD
+ *
+ * If the DP IN port has HDP set, this function can be used to clear it.
+ */
+int tb_dp_port_hpd_clear(struct tb_port *port)
+{
+	u32 data;
+	int ret;
+
+	ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap + 3, 1);
+	if (ret)
+		return ret;
+
+	data |= TB_DP_HPDC;
+	return tb_port_write(port, &data, TB_CFG_PORT, port->cap_adap + 3, 1);
+}
+
+/**
+ * tb_dp_port_set_hops() - Set video/aux Hop IDs for DP port
+ * @port: DP IN/OUT port to set hops
+ * @video: Video Hop ID
+ * @aux_tx: AUX TX Hop ID
+ * @aux_rx: AUX RX Hop ID
+ *
+ * Programs specified Hop IDs for DP IN/OUT port.
+ */
+int tb_dp_port_set_hops(struct tb_port *port, unsigned int video,
+			unsigned int aux_tx, unsigned int aux_rx)
+{
+	u32 data[2];
+	int ret;
+
+	ret = tb_port_read(port, data, TB_CFG_PORT, port->cap_adap,
+			   ARRAY_SIZE(data));
+	if (ret)
+		return ret;
+
+	data[0] &= ~TB_DP_VIDEO_HOPID_MASK;
+	data[1] &= ~(TB_DP_AUX_RX_HOPID_MASK | TB_DP_AUX_TX_HOPID_MASK);
+
+	data[0] |= (video << TB_DP_VIDEO_HOPID_SHIFT) & TB_DP_VIDEO_HOPID_MASK;
+	data[1] |= aux_tx & TB_DP_AUX_TX_HOPID_MASK;
+	data[1] |= (aux_rx << TB_DP_AUX_RX_HOPID_SHIFT) & TB_DP_AUX_RX_HOPID_MASK;
+
+	return tb_port_write(port, data, TB_CFG_PORT, port->cap_adap,
+			     ARRAY_SIZE(data));
+}
+
+/**
+ * tb_dp_port_is_enabled() - Is DP adapter port enabled
+ * @port: DP adapter port to check
+ */
+bool tb_dp_port_is_enabled(struct tb_port *port)
+{
+	u32 data;
+
+	if (tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap, 1))
+		return false;
+
+	return !!(data & (TB_DP_VIDEO_EN | TB_DP_AUX_EN));
+}
+
+/**
+ * tb_dp_port_enable() - Enables/disables DP paths of a port
+ * @port: DP IN/OUT port
+ * @enable: Enable/disable DP path
+ *
+ * Once Hop IDs are programmed DP paths can be enabled or disabled by
+ * calling this function.
+ */
+int tb_dp_port_enable(struct tb_port *port, bool enable)
+{
+	u32 data;
+	int ret;
+
+	ret = tb_port_read(port, &data, TB_CFG_PORT, port->cap_adap, 1);
+	if (ret)
+		return ret;
+
+	if (enable)
+		data |= TB_DP_VIDEO_EN | TB_DP_AUX_EN;
+	else
+		data &= ~(TB_DP_VIDEO_EN | TB_DP_AUX_EN);
+
+	return tb_port_write(port, &data, TB_CFG_PORT, port->cap_adap, 1);
+}
+
 /* switch utility functions */
 
 static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
@@ -644,24 +953,6 @@ int tb_switch_reset(struct tb *tb, u64 route)
 	return res.err;
 }
 
-struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route)
-{
-	u8 next_port = route; /*
-			       * Routes use a stride of 8 bits,
-			       * eventhough a port index has 6 bits at most.
-			       * */
-	if (route == 0)
-		return sw;
-	if (next_port > sw->config.max_port_number)
-		return NULL;
-	if (tb_is_upstream_port(&sw->ports[next_port]))
-		return NULL;
-	if (!sw->ports[next_port].remote)
-		return NULL;
-	return get_switch_at_route(sw->ports[next_port].remote->sw,
-				   route >> TB_ROUTE_SHIFT);
-}
-
 /**
  * tb_plug_events_active() - enable/disable plug events on a switch
  *
@@ -716,8 +1007,8 @@ static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
 {
 	int ret = -EINVAL;
 
-	if (mutex_lock_interruptible(&switch_lock))
-		return -ERESTARTSYS;
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
 
 	if (sw->authorized)
 		goto unlock;
@@ -760,7 +1051,7 @@ static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
 	}
 
 unlock:
-	mutex_unlock(&switch_lock);
+	mutex_unlock(&sw->tb->lock);
 	return ret;
 }
 
@@ -817,15 +1108,15 @@ static ssize_t key_show(struct device *dev, struct device_attribute *attr,
 	struct tb_switch *sw = tb_to_switch(dev);
 	ssize_t ret;
 
-	if (mutex_lock_interruptible(&switch_lock))
-		return -ERESTARTSYS;
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
 
 	if (sw->key)
 		ret = sprintf(buf, "%*phN\n", TB_SWITCH_KEY_SIZE, sw->key);
 	else
 		ret = sprintf(buf, "\n");
 
-	mutex_unlock(&switch_lock);
+	mutex_unlock(&sw->tb->lock);
 	return ret;
 }
 
@@ -842,8 +1133,8 @@ static ssize_t key_store(struct device *dev, struct device_attribute *attr,
 	else if (hex2bin(key, buf, sizeof(key)))
 		return -EINVAL;
 
-	if (mutex_lock_interruptible(&switch_lock))
-		return -ERESTARTSYS;
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
 
 	if (sw->authorized) {
 		ret = -EBUSY;
@@ -858,7 +1149,7 @@ static ssize_t key_store(struct device *dev, struct device_attribute *attr,
 		}
 	}
 
-	mutex_unlock(&switch_lock);
+	mutex_unlock(&sw->tb->lock);
 	return ret;
 }
 static DEVICE_ATTR(key, 0600, key_show, key_store);
@@ -904,8 +1195,8 @@ static ssize_t nvm_authenticate_store(struct device *dev,
 	bool val;
 	int ret;
 
-	if (mutex_lock_interruptible(&switch_lock))
-		return -ERESTARTSYS;
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
 
 	/* If NVMem devices are not yet added */
 	if (!sw->nvm) {
@@ -953,7 +1244,7 @@ static ssize_t nvm_authenticate_store(struct device *dev,
 	}
 
 exit_unlock:
-	mutex_unlock(&switch_lock);
+	mutex_unlock(&sw->tb->lock);
 
 	if (ret)
 		return ret;
@@ -967,8 +1258,8 @@ static ssize_t nvm_version_show(struct device *dev,
 	struct tb_switch *sw = tb_to_switch(dev);
 	int ret;
 
-	if (mutex_lock_interruptible(&switch_lock))
-		return -ERESTARTSYS;
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
 
 	if (sw->safe_mode)
 		ret = -ENODATA;
@@ -977,7 +1268,7 @@ static ssize_t nvm_version_show(struct device *dev,
 	else
 		ret = sprintf(buf, "%x.%x\n", sw->nvm->major, sw->nvm->minor);
 
-	mutex_unlock(&switch_lock);
+	mutex_unlock(&sw->tb->lock);
 
 	return ret;
 }
@@ -1063,9 +1354,17 @@ static const struct attribute_group *switch_groups[] = {
 static void tb_switch_release(struct device *dev)
 {
 	struct tb_switch *sw = tb_to_switch(dev);
+	int i;
 
 	dma_port_free(sw->dma_port);
 
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		if (!sw->ports[i].disabled) {
+			ida_destroy(&sw->ports[i].in_hopids);
+			ida_destroy(&sw->ports[i].out_hopids);
+		}
+	}
+
 	kfree(sw->uuid);
 	kfree(sw->device_name);
 	kfree(sw->vendor_name);
@@ -1150,24 +1449,32 @@ static int tb_switch_get_generation(struct tb_switch *sw)
  * separately. The returned switch should be released by calling
  * tb_switch_put().
  *
- * Return: Pointer to the allocated switch or %NULL in case of failure
+ * Return: Pointer to the allocated switch or ERR_PTR() in case of
+ * failure.
  */
 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 				  u64 route)
 {
-	int i;
-	int cap;
 	struct tb_switch *sw;
-	int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
+	int upstream_port;
+	int i, ret, depth;
+
+	/* Make sure we do not exceed maximum topology limit */
+	depth = tb_route_length(route);
+	if (depth > TB_SWITCH_MAX_DEPTH)
+		return ERR_PTR(-EADDRNOTAVAIL);
+
+	upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
 	if (upstream_port < 0)
-		return NULL;
+		return ERR_PTR(upstream_port);
 
 	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
 	if (!sw)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	sw->tb = tb;
-	if (tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5))
+	ret = tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5);
+	if (ret)
 		goto err_free_sw_ports;
 
 	tb_dbg(tb, "current switch config:\n");
@@ -1175,16 +1482,18 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 
 	/* configure switch */
 	sw->config.upstream_port_number = upstream_port;
-	sw->config.depth = tb_route_length(route);
-	sw->config.route_lo = route;
-	sw->config.route_hi = route >> 32;
+	sw->config.depth = depth;
+	sw->config.route_hi = upper_32_bits(route);
+	sw->config.route_lo = lower_32_bits(route);
 	sw->config.enabled = 0;
 
 	/* initialize ports */
 	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
 				GFP_KERNEL);
-	if (!sw->ports)
+	if (!sw->ports) {
+		ret = -ENOMEM;
 		goto err_free_sw_ports;
+	}
 
 	for (i = 0; i <= sw->config.max_port_number; i++) {
 		/* minimum setup for tb_find_cap and tb_drom_read to work */
@@ -1194,12 +1503,16 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 
 	sw->generation = tb_switch_get_generation(sw);
 
-	cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
-	if (cap < 0) {
+	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
+	if (ret < 0) {
 		tb_sw_warn(sw, "cannot find TB_VSE_CAP_PLUG_EVENTS aborting\n");
 		goto err_free_sw_ports;
 	}
-	sw->cap_plug_events = cap;
+	sw->cap_plug_events = ret;
+
+	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
+	if (ret > 0)
+		sw->cap_lc = ret;
 
 	/* Root switch is always authorized */
 	if (!route)
@@ -1218,7 +1531,7 @@ err_free_sw_ports:
 	kfree(sw->ports);
 	kfree(sw);
 
-	return NULL;
+	return ERR_PTR(ret);
 }
 
 /**
@@ -1233,7 +1546,7 @@ err_free_sw_ports:
  *
  * The returned switch must be released by calling tb_switch_put().
  *
- * Return: Pointer to the allocated switch or %NULL in case of failure
+ * Return: Pointer to the allocated switch or ERR_PTR() in case of failure
  */
 struct tb_switch *
 tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
@@ -1242,7 +1555,7 @@ tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
 
 	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
 	if (!sw)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	sw->tb = tb;
 	sw->config.depth = tb_route_length(route);
@@ -1291,25 +1604,27 @@ int tb_switch_configure(struct tb_switch *sw)
 	if (ret)
 		return ret;
 
+	ret = tb_lc_configure_link(sw);
+	if (ret)
+		return ret;
+
 	return tb_plug_events_active(sw, true);
 }
 
-static void tb_switch_set_uuid(struct tb_switch *sw)
+static int tb_switch_set_uuid(struct tb_switch *sw)
 {
 	u32 uuid[4];
-	int cap;
+	int ret;
 
 	if (sw->uuid)
-		return;
+		return 0;
 
 	/*
 	 * The newer controllers include fused UUID as part of link
 	 * controller specific registers
 	 */
-	cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
-	if (cap > 0) {
-		tb_sw_read(sw, uuid, TB_CFG_SWITCH, cap + 3, 4);
-	} else {
+	ret = tb_lc_read_uuid(sw, uuid);
+	if (ret) {
 		/*
 		 * ICM generates UUID based on UID and fills the upper
 		 * two words with ones. This is not strictly following
@@ -1323,6 +1638,9 @@ static void tb_switch_set_uuid(struct tb_switch *sw)
 	}
 
 	sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
+	if (!sw->uuid)
+		return -ENOMEM;
+	return 0;
 }
 
 static int tb_switch_add_dma_port(struct tb_switch *sw)
@@ -1372,7 +1690,9 @@ static int tb_switch_add_dma_port(struct tb_switch *sw)
 
 	if (status) {
 		tb_sw_info(sw, "switch flash authentication failed\n");
-		tb_switch_set_uuid(sw);
+		ret = tb_switch_set_uuid(sw);
+		if (ret)
+			return ret;
 		nvm_set_auth_status(sw, status);
 	}
 
@@ -1422,7 +1742,9 @@ int tb_switch_add(struct tb_switch *sw)
 		}
 		tb_sw_dbg(sw, "uid: %#llx\n", sw->uid);
 
-		tb_switch_set_uuid(sw);
+		ret = tb_switch_set_uuid(sw);
+		if (ret)
+			return ret;
 
 		for (i = 0; i <= sw->config.max_port_number; i++) {
 			if (sw->ports[i].disabled) {
@@ -1484,18 +1806,18 @@ void tb_switch_remove(struct tb_switch *sw)
 
 	/* port 0 is the switch itself and never has a remote */
 	for (i = 1; i <= sw->config.max_port_number; i++) {
-		if (tb_is_upstream_port(&sw->ports[i]))
-			continue;
-		if (sw->ports[i].remote)
+		if (tb_port_has_remote(&sw->ports[i])) {
 			tb_switch_remove(sw->ports[i].remote->sw);
-		sw->ports[i].remote = NULL;
-		if (sw->ports[i].xdomain)
+			sw->ports[i].remote = NULL;
+		} else if (sw->ports[i].xdomain) {
 			tb_xdomain_remove(sw->ports[i].xdomain);
-		sw->ports[i].xdomain = NULL;
+			sw->ports[i].xdomain = NULL;
+		}
 	}
 
 	if (!sw->is_unplugged)
 		tb_plug_events_active(sw, false);
+	tb_lc_unconfigure_link(sw);
 
 	tb_switch_nvm_remove(sw);
 
@@ -1520,8 +1842,10 @@ void tb_sw_set_unplugged(struct tb_switch *sw)
 	}
 	sw->is_unplugged = true;
 	for (i = 0; i <= sw->config.max_port_number; i++) {
-		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
+		if (tb_port_has_remote(&sw->ports[i]))
 			tb_sw_set_unplugged(sw->ports[i].remote->sw);
+		else if (sw->ports[i].xdomain)
+			sw->ports[i].xdomain->is_unplugged = true;
 	}
 }
 
@@ -1537,6 +1861,17 @@ int tb_switch_resume(struct tb_switch *sw)
 	if (tb_route(sw)) {
 		u64 uid;
 
+		/*
+		 * Check first that we can still read the switch config
+		 * space. It may be that there is now another domain
+		 * connected.
+		 */
+		err = tb_cfg_get_upstream_port(sw->tb->ctl, tb_route(sw));
+		if (err < 0) {
+			tb_sw_info(sw, "switch not present anymore\n");
+			return err;
+		}
+
 		err = tb_drom_read_uid_only(sw, &uid);
 		if (err) {
 			tb_sw_warn(sw, "uid read failed\n");
@@ -1555,6 +1890,10 @@ int tb_switch_resume(struct tb_switch *sw)
 	if (err)
 		return err;
 
+	err = tb_lc_configure_link(sw);
+	if (err)
+		return err;
+
 	err = tb_plug_events_active(sw, true);
 	if (err)
 		return err;
@@ -1562,15 +1901,23 @@ int tb_switch_resume(struct tb_switch *sw)
 	/* check for surviving downstream switches */
 	for (i = 1; i <= sw->config.max_port_number; i++) {
 		struct tb_port *port = &sw->ports[i];
-		if (tb_is_upstream_port(port))
-			continue;
-		if (!port->remote)
+
+		if (!tb_port_has_remote(port) && !port->xdomain)
 			continue;
-		if (tb_wait_for_port(port, true) <= 0
-			|| tb_switch_resume(port->remote->sw)) {
+
+		if (tb_wait_for_port(port, true) <= 0) {
 			tb_port_warn(port,
 				     "lost during suspend, disconnecting\n");
-			tb_sw_set_unplugged(port->remote->sw);
+			if (tb_port_has_remote(port))
+				tb_sw_set_unplugged(port->remote->sw);
+			else if (port->xdomain)
+				port->xdomain->is_unplugged = true;
+		} else if (tb_port_has_remote(port)) {
+			if (tb_switch_resume(port->remote->sw)) {
+				tb_port_warn(port,
+					     "lost during suspend, disconnecting\n");
+				tb_sw_set_unplugged(port->remote->sw);
+			}
 		}
 	}
 	return 0;
@@ -1584,13 +1931,11 @@ void tb_switch_suspend(struct tb_switch *sw)
 		return;
 
 	for (i = 1; i <= sw->config.max_port_number; i++) {
-		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
+		if (tb_port_has_remote(&sw->ports[i]))
 			tb_switch_suspend(sw->ports[i].remote->sw);
 	}
-	/*
-	 * TODO: invoke tb_cfg_prepare_to_sleep here? does not seem to have any
-	 * effect?
-	 */
+
+	tb_lc_set_sleep(sw);
 }
 
 struct tb_sw_lookup {
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 30e02c716f6c..1f7a9e1cc09c 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Thunderbolt Cactus Ridge driver - bus logic (NHI independent)
+ * Thunderbolt driver - bus logic (NHI independent)
  *
  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2019, Intel Corporation
  */
 
 #include <linux/slab.h>
@@ -12,7 +13,7 @@
 
 #include "tb.h"
 #include "tb_regs.h"
-#include "tunnel_pci.h"
+#include "tunnel.h"
 
 /**
  * struct tb_cm - Simple Thunderbolt connection manager
@@ -27,8 +28,100 @@ struct tb_cm {
 	bool hotplug_active;
 };
 
+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_discover_tunnels(struct tb_switch *sw)
+{
+	struct tb *tb = sw->tb;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *port;
+	int i;
+
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		struct tb_tunnel *tunnel = NULL;
+
+		port = &sw->ports[i];
+		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;
+
+		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);
+			}
+		}
+
+		list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	}
+
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		if (tb_port_has_remote(&sw->ports[i]))
+			tb_discover_tunnels(sw->ports[i].remote->sw);
+	}
+}
+
+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_xdomain_add(xd);
+	}
+}
 
 static void tb_scan_port(struct tb_port *port);
 
@@ -47,9 +140,21 @@ static void tb_scan_switch(struct tb_switch *sw)
  */
 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)
@@ -60,45 +165,95 @@ static void tb_scan_port(struct tb_port *port)
 	if (tb_wait_for_port(port, false) <= 0)
 		return;
 	if (port->remote) {
-		tb_port_WARN(port, "port already has a remote!\n");
+		tb_port_dbg(port, "port already has a remote\n");
 		return;
 	}
 	sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
 			     tb_downstream_route(port));
-	if (!sw)
+	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;
 	}
 
-	sw->authorized = true;
+	/*
+	 * If there was previously another domain connected remove it
+	 * first.
+	 */
+	if (port->xdomain) {
+		tb_xdomain_remove(port->xdomain);
+		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);
 
 	if (tb_switch_add(sw)) {
 		tb_switch_put(sw);
 		return;
 	}
 
-	port->remote = tb_upstream_port(sw);
-	tb_upstream_port(sw)->remote = port;
+	/* 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;
+	}
+
 	tb_scan_switch(sw);
 }
 
+static int tb_free_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))) {
+			tb_tunnel_deactivate(tunnel);
+			list_del(&tunnel->list);
+			tb_tunnel_free(tunnel);
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
 /**
  * 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_pci_tunnel *tunnel;
-	struct tb_pci_tunnel *n;
+	struct tb_tunnel *tunnel;
+	struct tb_tunnel *n;
 
 	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
-		if (tb_pci_is_invalid(tunnel)) {
-			tb_pci_deactivate(tunnel);
+		if (tb_tunnel_is_invalid(tunnel)) {
+			tb_tunnel_deactivate(tunnel);
 			list_del(&tunnel->list);
-			tb_pci_free(tunnel);
+			tb_tunnel_free(tunnel);
 		}
 	}
 }
@@ -111,136 +266,232 @@ static void tb_free_unplugged_children(struct tb_switch *sw)
 	int i;
 	for (i = 1; i <= sw->config.max_port_number; i++) {
 		struct tb_port *port = &sw->ports[i];
-		if (tb_is_upstream_port(port))
-			continue;
-		if (!port->remote)
+
+		if (!tb_port_has_remote(port))
 			continue;
+
 		if (port->remote->sw->is_unplugged) {
 			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);
 		}
 	}
 }
 
-
 /**
- * find_pci_up_port() - return the first PCIe up port on @sw or NULL
+ * tb_find_port() - return the first port of @type on @sw or NULL
+ * @sw: Switch to find the port from
+ * @type: Port type to look for
  */
-static struct tb_port *tb_find_pci_up_port(struct tb_switch *sw)
+static struct tb_port *tb_find_port(struct tb_switch *sw,
+				    enum tb_port_type type)
 {
 	int i;
 	for (i = 1; i <= sw->config.max_port_number; i++)
-		if (sw->ports[i].config.type == TB_TYPE_PCIE_UP)
+		if (sw->ports[i].config.type == type)
 			return &sw->ports[i];
 	return NULL;
 }
 
 /**
- * find_unused_down_port() - return the first inactive PCIe down port on @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_down_port(struct tb_switch *sw)
+static struct tb_port *tb_find_unused_port(struct tb_switch *sw,
+					   enum tb_port_type type)
 {
 	int i;
-	int cap;
-	int res;
-	int data;
+
 	for (i = 1; i <= sw->config.max_port_number; i++) {
 		if (tb_is_upstream_port(&sw->ports[i]))
 			continue;
-		if (sw->ports[i].config.type != TB_TYPE_PCIE_DOWN)
-			continue;
-		cap = tb_port_find_cap(&sw->ports[i], TB_PORT_CAP_ADAP);
-		if (cap < 0)
+		if (sw->ports[i].config.type != type)
 			continue;
-		res = tb_port_read(&sw->ports[i], &data, TB_CFG_PORT, cap, 1);
-		if (res < 0)
+		if (!sw->ports[i].cap_adap)
 			continue;
-		if (data & 0x80000000)
+		if (tb_port_is_enabled(&sw->ports[i]))
 			continue;
 		return &sw->ports[i];
 	}
 	return NULL;
 }
 
-/**
- * tb_activate_pcie_devices() - scan for and activate PCIe devices
- *
- * This method is somewhat ad hoc. For now it only supports one device
- * per port and only devices at depth 1.
- */
-static void tb_activate_pcie_devices(struct tb *tb)
+static struct tb_port *tb_find_pcie_down(struct tb_switch *sw,
+					 const struct tb_port *port)
+{
+	/*
+	 * To keep plugging devices consistently in the same PCIe
+	 * hierarchy, do mapping here for root switch downstream PCIe
+	 * ports.
+	 */
+	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_cr(sw))
+			index = !phy_port ? 6 : 7;
+		else if (tb_switch_is_fr(sw))
+			index = !phy_port ? 6 : 8;
+		else
+			goto out;
+
+		/* Validate the hard-coding */
+		if (WARN_ON(index > sw->config.max_port_number))
+			goto out;
+		if (WARN_ON(!tb_port_is_pcie_down(&sw->ports[index])))
+			goto out;
+		if (WARN_ON(tb_pci_port_is_enabled(&sw->ports[index])))
+			goto out;
+
+		return &sw->ports[index];
+	}
+
+out:
+	return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
+}
+
+static int tb_tunnel_dp(struct tb *tb, struct tb_port *out)
 {
-	int i;
-	int cap;
-	u32 data;
-	struct tb_switch *sw;
-	struct tb_port *up_port;
-	struct tb_port *down_port;
-	struct tb_pci_tunnel *tunnel;
 	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_switch *sw = out->sw;
+	struct tb_tunnel *tunnel;
+	struct tb_port *in;
+
+	if (tb_port_is_enabled(out))
+		return 0;
+
+	do {
+		sw = tb_to_switch(sw->dev.parent);
+		if (!sw)
+			return 0;
+		in = tb_find_unused_port(sw, TB_TYPE_DP_HDMI_IN);
+	} while (!in);
+
+	tunnel = tb_tunnel_alloc_dp(tb, in, out);
+	if (!tunnel) {
+		tb_port_dbg(out, "DP tunnel allocation failed\n");
+		return -ENOMEM;
+	}
 
-	/* scan for pcie devices at depth 1*/
-	for (i = 1; i <= tb->root_switch->config.max_port_number; i++) {
-		if (tb_is_upstream_port(&tb->root_switch->ports[i]))
-			continue;
-		if (tb->root_switch->ports[i].config.type != TB_TYPE_PORT)
-			continue;
-		if (!tb->root_switch->ports[i].remote)
-			continue;
-		sw = tb->root_switch->ports[i].remote->sw;
-		up_port = tb_find_pci_up_port(sw);
-		if (!up_port) {
-			tb_sw_info(sw, "no PCIe devices found, aborting\n");
-			continue;
-		}
+	if (tb_tunnel_activate(tunnel)) {
+		tb_port_info(out, "DP tunnel activation failed, aborting\n");
+		tb_tunnel_free(tunnel);
+		return -EIO;
+	}
 
-		/* check whether port is already activated */
-		cap = tb_port_find_cap(up_port, TB_PORT_CAP_ADAP);
-		if (cap < 0)
-			continue;
-		if (tb_port_read(up_port, &data, TB_CFG_PORT, cap, 1))
-			continue;
-		if (data & 0x80000000) {
-			tb_port_info(up_port,
-				     "PCIe port already activated, aborting\n");
-			continue;
-		}
+	list_add_tail(&tunnel->list, &tcm->tunnel_list);
+	return 0;
+}
 
-		down_port = tb_find_unused_down_port(tb->root_switch);
-		if (!down_port) {
-			tb_port_info(up_port,
-				     "All PCIe down ports are occupied, aborting\n");
-			continue;
-		}
-		tunnel = tb_pci_alloc(tb, up_port, down_port);
-		if (!tunnel) {
-			tb_port_info(up_port,
-				     "PCIe tunnel allocation failed, aborting\n");
-			continue;
-		}
+static void tb_teardown_dp(struct tb *tb, struct tb_port *out)
+{
+	tb_free_tunnel(tb, TB_TUNNEL_DP, NULL, out);
+}
 
-		if (tb_pci_activate(tunnel)) {
-			tb_port_info(up_port,
-				     "PCIe tunnel activation failed, aborting\n");
-			tb_pci_free(tunnel);
-			continue;
-		}
+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_find_port(sw, TB_TYPE_PCIE_UP);
+	if (!up)
+		return 0;
 
-		list_add(&tunnel->list, &tcm->tunnel_list);
+	/*
+	 * 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;
 }
 
-/* hotplug handling */
+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;
 
-struct tb_hotplug_event {
-	struct work_struct work;
-	struct tb *tb;
-	u64 route;
-	u8 port;
-	bool unplug;
-};
+	sw = tb_to_switch(xd->dev.parent);
+	dst_port = tb_port_at(xd->route, sw);
+	nhi_port = tb_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_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.
+	 */
+	tb_free_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
+}
+
+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
@@ -258,7 +509,7 @@ static void tb_handle_hotplug(struct work_struct *work)
 	if (!tcm->hotplug_active)
 		goto out; /* during init, suspend or shutdown */
 
-	sw = get_switch_at_route(tb->root_switch, ev->route);
+	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",
@@ -269,43 +520,60 @@ static void tb_handle_hotplug(struct work_struct *work)
 		tb_warn(tb,
 			"hotplug event from non existent port %llx:%x (unplug: %d)\n",
 			ev->route, ev->port, ev->unplug);
-		goto out;
+		goto put_sw;
 	}
 	port = &sw->ports[ev->port];
 	if (tb_is_upstream_port(port)) {
-		tb_warn(tb,
-			"hotplug event for upstream port %llx:%x (unplug: %d)\n",
-			ev->route, ev->port, ev->unplug);
-		goto out;
+		tb_dbg(tb, "hotplug event for upstream port %llx:%x (unplug: %d)\n",
+		       ev->route, ev->port, ev->unplug);
+		goto put_sw;
 	}
 	if (ev->unplug) {
-		if (port->remote) {
-			tb_port_info(port, "unplugged\n");
+		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_switch_remove(port->remote->sw);
 			port->remote = NULL;
+			if (port->dual_link_port)
+				port->dual_link_port->remote = NULL;
+		} 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);
+		} else if (tb_port_is_dpout(port)) {
+			tb_teardown_dp(tb, port);
 		} else {
-			tb_port_info(port,
-				     "got unplug event for disconnected port, ignoring\n");
+			tb_port_dbg(port,
+				   "got unplug event for disconnected port, ignoring\n");
 		}
 	} else if (port->remote) {
-		tb_port_info(port,
-			     "got plug event for connected port, ignoring\n");
+		tb_port_dbg(port, "got plug event for connected port, ignoring\n");
 	} else {
-		tb_port_info(port, "hotplug: scanning\n");
-		tb_scan_port(port);
-		if (!port->remote) {
-			tb_port_info(port, "hotplug: no switch found\n");
-		} else if (port->remote->sw->config.depth > 1) {
-			tb_sw_warn(port->remote->sw,
-				   "hotplug: chaining not supported\n");
-		} else {
-			tb_sw_info(port->remote->sw,
-				   "hotplug: activating pcie devices\n");
-			tb_activate_pcie_devices(tb);
+		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_tunnel_dp(tb, port);
 		}
 	}
+
+put_sw:
+	tb_switch_put(sw);
 out:
 	mutex_unlock(&tb->lock);
 	kfree(ev);
@@ -320,7 +588,6 @@ 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;
-	struct tb_hotplug_event *ev;
 	u64 route;
 
 	if (type != TB_CFG_PKG_EVENT) {
@@ -336,40 +603,59 @@ static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
 			pkg->port);
 	}
 
-	ev = kmalloc(sizeof(*ev), GFP_KERNEL);
-	if (!ev)
-		return;
-	INIT_WORK(&ev->work, tb_handle_hotplug);
-	ev->tb = tb;
-	ev->route = route;
-	ev->port = pkg->port;
-	ev->unplug = pkg->unplug;
-	queue_work(tb->wq, &ev->work);
+	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_pci_tunnel *tunnel;
-	struct tb_pci_tunnel *n;
+	struct tb_tunnel *tunnel;
+	struct tb_tunnel *n;
 
 	/* tunnels are only present after everything has been initialized */
 	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
-		tb_pci_deactivate(tunnel);
-		tb_pci_free(tunnel);
+		/*
+		 * 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 (!tb->root_switch)
-		return -ENOMEM;
+	if (IS_ERR(tb->root_switch))
+		return PTR_ERR(tb->root_switch);
 
 	/*
 	 * ICM firmware upgrade needs running firmware and in native
@@ -393,7 +679,11 @@ static int tb_start(struct tb *tb)
 
 	/* Full scan to discover devices added before the driver was loaded. */
 	tb_scan_switch(tb->root_switch);
-	tb_activate_pcie_devices(tb);
+	/* Find out tunnels created by the boot firmware */
+	tb_discover_tunnels(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;
@@ -415,7 +705,7 @@ static int tb_suspend_noirq(struct tb *tb)
 static int tb_resume_noirq(struct tb *tb)
 {
 	struct tb_cm *tcm = tb_priv(tb);
-	struct tb_pci_tunnel *tunnel, *n;
+	struct tb_tunnel *tunnel, *n;
 
 	tb_dbg(tb, "resuming...\n");
 
@@ -426,7 +716,7 @@ static int tb_resume_noirq(struct tb *tb)
 	tb_free_invalid_tunnels(tb);
 	tb_free_unplugged_children(tb->root_switch);
 	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
-		tb_pci_restart(tunnel);
+		tb_tunnel_restart(tunnel);
 	if (!list_empty(&tcm->tunnel_list)) {
 		/*
 		 * the pcie links need some time to get going.
@@ -442,12 +732,50 @@ static int tb_resume_noirq(struct tb *tb)
 	return 0;
 }
 
+static int tb_free_unplugged_xdomains(struct tb_switch *sw)
+{
+	int i, ret = 0;
+
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		struct tb_port *port = &sw->ports[i];
+
+		if (tb_is_upstream_port(port))
+			continue;
+		if (port->xdomain && port->xdomain->is_unplugged) {
+			tb_xdomain_remove(port->xdomain);
+			port->xdomain = NULL;
+			ret++;
+		} else if (port->remote) {
+			ret += tb_free_unplugged_xdomains(port->remote->sw);
+		}
+	}
+
+	return ret;
+}
+
+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 const struct tb_cm_ops tb_cm_ops = {
 	.start = tb_start,
 	.stop = tb_stop,
 	.suspend_noirq = tb_suspend_noirq,
 	.resume_noirq = tb_resume_noirq,
+	.complete = tb_complete,
 	.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)
@@ -462,7 +790,7 @@ struct tb *tb_probe(struct tb_nhi *nhi)
 	if (!tb)
 		return NULL;
 
-	tb->security_level = TB_SECURITY_NONE;
+	tb->security_level = TB_SECURITY_USER;
 	tb->cm_ops = &tb_cm_ops;
 
 	tcm = tb_priv(tb);
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 52584c4003e3..b12c8f33d89c 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -43,6 +43,7 @@ struct tb_switch_nvm {
 };
 
 #define TB_SWITCH_KEY_SIZE		32
+#define TB_SWITCH_MAX_DEPTH		6
 
 /**
  * struct tb_switch - a thunderbolt switch
@@ -62,6 +63,7 @@ struct tb_switch_nvm {
  * @device_name: Name of the device (or %NULL if not known)
  * @generation: Switch Thunderbolt generation
  * @cap_plug_events: Offset to the plug events capability (%0 if not found)
+ * @cap_lc: Offset to the link controller capability (%0 if not found)
  * @is_unplugged: The switch is going away
  * @drom: DROM of the switch (%NULL if not found)
  * @nvm: Pointer to the NVM if the switch has one (%NULL otherwise)
@@ -70,7 +72,6 @@ struct tb_switch_nvm {
  * @boot: Whether the switch was already authorized on boot or not
  * @rpm: The switch supports runtime PM
  * @authorized: Whether the switch is authorized by user or policy
- * @work: Work used to automatically authorize a switch
  * @security_level: Switch supported security level
  * @key: Contains the key used to challenge the device or %NULL if not
  *	 supported. Size of the key is %TB_SWITCH_KEY_SIZE.
@@ -80,8 +81,7 @@ struct tb_switch_nvm {
  * @depth: Depth in the chain this switch is connected (ICM only)
  *
  * When the switch is being added or removed to the domain (other
- * switches) you need to have domain lock held. For switch authorization
- * internal switch_lock is enough.
+ * switches) you need to have domain lock held.
  */
 struct tb_switch {
 	struct device dev;
@@ -97,6 +97,7 @@ struct tb_switch {
 	const char *device_name;
 	unsigned int generation;
 	int cap_plug_events;
+	int cap_lc;
 	bool is_unplugged;
 	u8 *drom;
 	struct tb_switch_nvm *nvm;
@@ -105,7 +106,6 @@ struct tb_switch {
 	bool boot;
 	bool rpm;
 	unsigned int authorized;
-	struct work_struct work;
 	enum tb_security_level security_level;
 	u8 *key;
 	u8 connection_id;
@@ -121,11 +121,14 @@ struct tb_switch {
  * @remote: Remote port (%NULL if not connected)
  * @xdomain: Remote host (%NULL if not connected)
  * @cap_phy: Offset, zero if not found
+ * @cap_adap: Offset of the adapter specific capability (%0 if not present)
  * @port: Port number on switch
  * @disabled: Disabled by eeprom
  * @dual_link_port: If the switch is connected using two ports, points
  *		    to the other port.
  * @link_nr: Is this primary or secondary port on the dual_link.
+ * @in_hopids: Currently allocated input HopIDs
+ * @out_hopids: Currently allocated output HopIDs
  */
 struct tb_port {
 	struct tb_regs_port_header config;
@@ -133,19 +136,35 @@ struct tb_port {
 	struct tb_port *remote;
 	struct tb_xdomain *xdomain;
 	int cap_phy;
+	int cap_adap;
 	u8 port;
 	bool disabled;
 	struct tb_port *dual_link_port;
 	u8 link_nr:1;
+	struct ida in_hopids;
+	struct ida out_hopids;
 };
 
 /**
  * struct tb_path_hop - routing information for a tb_path
+ * @in_port: Ingress port of a switch
+ * @out_port: Egress port of a switch where the packet is routed out
+ *	      (must be on the same switch than @in_port)
+ * @in_hop_index: HopID where the path configuration entry is placed in
+ *		  the path config space of @in_port.
+ * @in_counter_index: Used counter index (not used in the driver
+ *		      currently, %-1 to disable)
+ * @next_hop_index: HopID of the packet when it is routed out from @out_port
+ * @initial_credits: Number of initial flow control credits allocated for
+ *		     the path
  *
  * Hop configuration is always done on the IN port of a switch.
  * in_port and out_port have to be on the same switch. Packets arriving on
  * in_port with "hop" = in_hop_index will get routed to through out_port. The
- * next hop to take (on out_port->remote) is determined by next_hop_index.
+ * next hop to take (on out_port->remote) is determined by
+ * next_hop_index. When routing packet to another switch (out->remote is
+ * set) the @next_hop_index must match the @in_hop_index of that next
+ * hop to make routing possible.
  *
  * in_counter_index is the index of a counter (in TB_CFG_COUNTERS) on the in
  * port.
@@ -154,44 +173,71 @@ struct tb_path_hop {
 	struct tb_port *in_port;
 	struct tb_port *out_port;
 	int in_hop_index;
-	int in_counter_index; /* write -1 to disable counters for this hop. */
+	int in_counter_index;
 	int next_hop_index;
+	unsigned int initial_credits;
 };
 
 /**
  * enum tb_path_port - path options mask
+ * @TB_PATH_NONE: Do not activate on any hop on path
+ * @TB_PATH_SOURCE: Activate on the first hop (out of src)
+ * @TB_PATH_INTERNAL: Activate on the intermediate hops (not the first/last)
+ * @TB_PATH_DESTINATION: Activate on the last hop (into dst)
+ * @TB_PATH_ALL: Activate on all hops on the path
  */
 enum tb_path_port {
 	TB_PATH_NONE = 0,
-	TB_PATH_SOURCE = 1, /* activate on the first hop (out of src) */
-	TB_PATH_INTERNAL = 2, /* activate on other hops (not the first/last) */
-	TB_PATH_DESTINATION = 4, /* activate on the last hop (into dst) */
+	TB_PATH_SOURCE = 1,
+	TB_PATH_INTERNAL = 2,
+	TB_PATH_DESTINATION = 4,
 	TB_PATH_ALL = 7,
 };
 
 /**
  * struct tb_path - a unidirectional path between two ports
+ * @tb: Pointer to the domain structure
+ * @name: Name of the path (used for debugging)
+ * @nfc_credits: Number of non flow controlled credits allocated for the path
+ * @ingress_shared_buffer: Shared buffering used for ingress ports on the path
+ * @egress_shared_buffer: Shared buffering used for egress ports on the path
+ * @ingress_fc_enable: Flow control for ingress ports on the path
+ * @egress_fc_enable: Flow control for egress ports on the path
+ * @priority: Priority group if the path
+ * @weight: Weight of the path inside the priority group
+ * @drop_packages: Drop packages from queue tail or head
+ * @activated: Is the path active
+ * @clear_fc: Clear all flow control from the path config space entries
+ *	      when deactivating this path
+ * @hops: Path hops
+ * @path_length: How many hops the path uses
  *
- * A path consists of a number of hops (see tb_path_hop). To establish a PCIe
- * tunnel two paths have to be created between the two PCIe ports.
- *
+ * A path consists of a number of hops (see &struct tb_path_hop). To
+ * establish a PCIe tunnel two paths have to be created between the two
+ * PCIe ports.
  */
 struct tb_path {
 	struct tb *tb;
-	int nfc_credits; /* non flow controlled credits */
+	const char *name;
+	int nfc_credits;
 	enum tb_path_port ingress_shared_buffer;
 	enum tb_path_port egress_shared_buffer;
 	enum tb_path_port ingress_fc_enable;
 	enum tb_path_port egress_fc_enable;
 
-	int priority:3;
+	unsigned int priority:3;
 	int weight:4;
 	bool drop_packages;
 	bool activated;
+	bool clear_fc;
 	struct tb_path_hop *hops;
-	int path_length; /* number of hops */
+	int path_length;
 };
 
+/* HopIDs 0-7 are reserved by the Thunderbolt protocol */
+#define TB_PATH_MIN_HOPID	8
+#define TB_PATH_MAX_HOPS	7
+
 /**
  * struct tb_cm_ops - Connection manager specific operations vector
  * @driver_ready: Called right after control channel is started. Used by
@@ -261,7 +307,20 @@ static inline struct tb_port *tb_upstream_port(struct tb_switch *sw)
 	return &sw->ports[sw->config.upstream_port_number];
 }
 
-static inline u64 tb_route(struct tb_switch *sw)
+/**
+ * tb_is_upstream_port() - Is the port upstream facing
+ * @port: Port to check
+ *
+ * Returns true if @port is upstream facing port. In case of dual link
+ * ports both return true.
+ */
+static inline bool tb_is_upstream_port(const struct tb_port *port)
+{
+	const struct tb_port *upstream_port = tb_upstream_port(port->sw);
+	return port == upstream_port || port->dual_link_port == upstream_port;
+}
+
+static inline u64 tb_route(const struct tb_switch *sw)
 {
 	return ((u64) sw->config.route_hi) << 32 | sw->config.route_lo;
 }
@@ -276,9 +335,54 @@ static inline struct tb_port *tb_port_at(u64 route, struct tb_switch *sw)
 	return &sw->ports[port];
 }
 
+/**
+ * tb_port_has_remote() - Does the port have switch connected downstream
+ * @port: Port to check
+ *
+ * Returns true only when the port is primary port and has remote set.
+ */
+static inline bool tb_port_has_remote(const struct tb_port *port)
+{
+	if (tb_is_upstream_port(port))
+		return false;
+	if (!port->remote)
+		return false;
+	if (port->dual_link_port && port->link_nr)
+		return false;
+
+	return true;
+}
+
+static inline bool tb_port_is_null(const struct tb_port *port)
+{
+	return port && port->port && port->config.type == TB_TYPE_PORT;
+}
+
+static inline bool tb_port_is_pcie_down(const struct tb_port *port)
+{
+	return port && port->config.type == TB_TYPE_PCIE_DOWN;
+}
+
+static inline bool tb_port_is_pcie_up(const struct tb_port *port)
+{
+	return port && port->config.type == TB_TYPE_PCIE_UP;
+}
+
+static inline bool tb_port_is_dpin(const struct tb_port *port)
+{
+	return port && port->config.type == TB_TYPE_DP_HDMI_IN;
+}
+
+static inline bool tb_port_is_dpout(const struct tb_port *port)
+{
+	return port && port->config.type == TB_TYPE_DP_HDMI_OUT;
+}
+
 static inline int tb_sw_read(struct tb_switch *sw, void *buffer,
 			     enum tb_cfg_space space, u32 offset, u32 length)
 {
+	if (sw->is_unplugged)
+		return -ENODEV;
 	return tb_cfg_read(sw->tb->ctl,
 			   buffer,
 			   tb_route(sw),
@@ -291,6 +395,8 @@ static inline int tb_sw_read(struct tb_switch *sw, void *buffer,
 static inline int tb_sw_write(struct tb_switch *sw, void *buffer,
 			      enum tb_cfg_space space, u32 offset, u32 length)
 {
+	if (sw->is_unplugged)
+		return -ENODEV;
 	return tb_cfg_write(sw->tb->ctl,
 			    buffer,
 			    tb_route(sw),
@@ -303,6 +409,8 @@ static inline int tb_sw_write(struct tb_switch *sw, void *buffer,
 static inline int tb_port_read(struct tb_port *port, void *buffer,
 			       enum tb_cfg_space space, u32 offset, u32 length)
 {
+	if (port->sw->is_unplugged)
+		return -ENODEV;
 	return tb_cfg_read(port->sw->tb->ctl,
 			   buffer,
 			   tb_route(port->sw),
@@ -315,6 +423,8 @@ static inline int tb_port_read(struct tb_port *port, void *buffer,
 static inline int tb_port_write(struct tb_port *port, const void *buffer,
 				enum tb_cfg_space space, u32 offset, u32 length)
 {
+	if (port->sw->is_unplugged)
+		return -ENODEV;
 	return tb_cfg_write(port->sw->tb->ctl,
 			    buffer,
 			    tb_route(port->sw),
@@ -332,7 +442,7 @@ static inline int tb_port_write(struct tb_port *port, const void *buffer,
 
 #define __TB_SW_PRINT(level, sw, fmt, arg...)           \
 	do {                                            \
-		struct tb_switch *__sw = (sw);          \
+		const struct tb_switch *__sw = (sw);    \
 		level(__sw->tb, "%llx: " fmt,           \
 		      tb_route(__sw), ## arg);          \
 	} while (0)
@@ -343,7 +453,7 @@ static inline int tb_port_write(struct tb_port *port, const void *buffer,
 
 #define __TB_PORT_PRINT(level, _port, fmt, arg...)                      \
 	do {                                                            \
-		struct tb_port *__port = (_port);                       \
+		const struct tb_port *__port = (_port);                 \
 		level(__port->sw->tb, "%llx:%x: " fmt,                  \
 		      tb_route(__port->sw), __port->port, ## arg);      \
 	} while (0)
@@ -385,6 +495,13 @@ int tb_domain_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd);
 int tb_domain_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd);
 int tb_domain_disconnect_all_paths(struct tb *tb);
 
+static inline struct tb *tb_domain_get(struct tb *tb)
+{
+	if (tb)
+		get_device(&tb->dev);
+	return tb;
+}
+
 static inline void tb_domain_put(struct tb *tb)
 {
 	put_device(&tb->dev);
@@ -401,7 +518,6 @@ void tb_switch_suspend(struct tb_switch *sw);
 int tb_switch_resume(struct tb_switch *sw);
 int tb_switch_reset(struct tb *tb, u64 route);
 void tb_sw_set_unplugged(struct tb_switch *sw);
-struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route);
 struct tb_switch *tb_switch_find_by_link_depth(struct tb *tb, u8 link,
 					       u8 depth);
 struct tb_switch *tb_switch_find_by_uuid(struct tb *tb, const uuid_t *uuid);
@@ -431,14 +547,74 @@ static inline struct tb_switch *tb_to_switch(struct device *dev)
 	return NULL;
 }
 
+static inline struct tb_switch *tb_switch_parent(struct tb_switch *sw)
+{
+	return tb_to_switch(sw->dev.parent);
+}
+
+static inline bool tb_switch_is_lr(const struct tb_switch *sw)
+{
+	return sw->config.device_id == PCI_DEVICE_ID_INTEL_LIGHT_RIDGE;
+}
+
+static inline bool tb_switch_is_er(const struct tb_switch *sw)
+{
+	return sw->config.device_id == PCI_DEVICE_ID_INTEL_EAGLE_RIDGE;
+}
+
+static inline bool tb_switch_is_cr(const struct tb_switch *sw)
+{
+	switch (sw->config.device_id) {
+	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_2C:
+	case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline bool tb_switch_is_fr(const struct tb_switch *sw)
+{
+	switch (sw->config.device_id) {
+	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE:
+	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE:
+		return true;
+	default:
+		return false;
+	}
+}
+
 int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged);
 int tb_port_add_nfc_credits(struct tb_port *port, int credits);
+int tb_port_set_initial_credits(struct tb_port *port, u32 credits);
 int tb_port_clear_counter(struct tb_port *port, int counter);
+int tb_port_alloc_in_hopid(struct tb_port *port, int hopid, int max_hopid);
+void tb_port_release_in_hopid(struct tb_port *port, int hopid);
+int tb_port_alloc_out_hopid(struct tb_port *port, int hopid, int max_hopid);
+void tb_port_release_out_hopid(struct tb_port *port, int hopid);
+struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
+				     struct tb_port *prev);
 
 int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
 int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap);
-
-struct tb_path *tb_path_alloc(struct tb *tb, int num_hops);
+bool tb_port_is_enabled(struct tb_port *port);
+
+bool tb_pci_port_is_enabled(struct tb_port *port);
+int tb_pci_port_enable(struct tb_port *port, bool enable);
+
+int tb_dp_port_hpd_is_active(struct tb_port *port);
+int tb_dp_port_hpd_clear(struct tb_port *port);
+int tb_dp_port_set_hops(struct tb_port *port, unsigned int video,
+			unsigned int aux_tx, unsigned int aux_rx);
+bool tb_dp_port_is_enabled(struct tb_port *port);
+int tb_dp_port_enable(struct tb_port *port, bool enable);
+
+struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
+				 struct tb_port *dst, int dst_hopid,
+				 struct tb_port **last, const char *name);
+struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
+			      struct tb_port *dst, int dst_hopid, int link_nr,
+			      const char *name);
 void tb_path_free(struct tb_path *path);
 int tb_path_activate(struct tb_path *path);
 void tb_path_deactivate(struct tb_path *path);
@@ -447,17 +623,16 @@ bool tb_path_is_invalid(struct tb_path *path);
 int tb_drom_read(struct tb_switch *sw);
 int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid);
 
+int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid);
+int tb_lc_configure_link(struct tb_switch *sw);
+void tb_lc_unconfigure_link(struct tb_switch *sw);
+int tb_lc_set_sleep(struct tb_switch *sw);
 
 static inline int tb_route_length(u64 route)
 {
 	return (fls64(route) + TB_ROUTE_SHIFT - 1) / TB_ROUTE_SHIFT;
 }
 
-static inline bool tb_is_upstream_port(struct tb_port *port)
-{
-	return port == tb_upstream_port(port->sw);
-}
-
 /**
  * tb_downstream_route() - get route to downstream switch
  *
diff --git a/drivers/thunderbolt/tb_msgs.h b/drivers/thunderbolt/tb_msgs.h
index 02c84aa3d018..afbe1d29bb03 100644
--- a/drivers/thunderbolt/tb_msgs.h
+++ b/drivers/thunderbolt/tb_msgs.h
@@ -492,6 +492,17 @@ struct tb_xdp_header {
 	u32 type;
 };
 
+struct tb_xdp_uuid {
+	struct tb_xdp_header hdr;
+};
+
+struct tb_xdp_uuid_response {
+	struct tb_xdp_header hdr;
+	uuid_t src_uuid;
+	u32 src_route_hi;
+	u32 src_route_lo;
+};
+
 struct tb_xdp_properties {
 	struct tb_xdp_header hdr;
 	uuid_t src_uuid;
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 6f1ff04ee195..deb9d4a977b9 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -211,6 +211,38 @@ struct tb_regs_port_header {
 
 } __packed;
 
+/* DWORD 4 */
+#define TB_PORT_NFC_CREDITS_MASK	GENMASK(19, 0)
+#define TB_PORT_MAX_CREDITS_SHIFT	20
+#define TB_PORT_MAX_CREDITS_MASK	GENMASK(26, 20)
+/* DWORD 5 */
+#define TB_PORT_LCA_SHIFT		22
+#define TB_PORT_LCA_MASK		GENMASK(28, 22)
+
+/* Display Port adapter registers */
+
+/* DWORD 0 */
+#define TB_DP_VIDEO_HOPID_SHIFT		16
+#define TB_DP_VIDEO_HOPID_MASK		GENMASK(26, 16)
+#define TB_DP_AUX_EN			BIT(30)
+#define TB_DP_VIDEO_EN			BIT(31)
+/* DWORD 1 */
+#define TB_DP_AUX_TX_HOPID_MASK		GENMASK(10, 0)
+#define TB_DP_AUX_RX_HOPID_SHIFT	11
+#define TB_DP_AUX_RX_HOPID_MASK		GENMASK(21, 11)
+/* DWORD 2 */
+#define TB_DP_HDP			BIT(6)
+/* DWORD 3 */
+#define TB_DP_HPDC			BIT(9)
+/* DWORD 4 */
+#define TB_DP_LOCAL_CAP			0x4
+/* DWORD 5 */
+#define TB_DP_REMOTE_CAP		0x5
+
+/* PCIe adapter registers */
+
+#define TB_PCI_EN			BIT(31)
+
 /* Hop register from TB_CFG_HOPS. 8 byte per entry. */
 struct tb_regs_hop {
 	/* DWORD 0 */
@@ -234,8 +266,24 @@ struct tb_regs_hop {
 	bool egress_fc:1;
 	bool ingress_shared_buffer:1;
 	bool egress_shared_buffer:1;
-	u32 unknown3:4; /* set to zero */
+	bool pending:1;
+	u32 unknown3:3; /* set to zero */
 } __packed;
 
+/* Common link controller registers */
+#define TB_LC_DESC			0x02
+#define TB_LC_DESC_NLC_MASK		GENMASK(3, 0)
+#define TB_LC_DESC_SIZE_SHIFT		8
+#define TB_LC_DESC_SIZE_MASK		GENMASK(15, 8)
+#define TB_LC_DESC_PORT_SIZE_SHIFT	16
+#define TB_LC_DESC_PORT_SIZE_MASK	GENMASK(27, 16)
+#define TB_LC_FUSE			0x03
+
+/* Link controller registers */
+#define TB_LC_SX_CTRL			0x96
+#define TB_LC_SX_CTRL_L1C		BIT(16)
+#define TB_LC_SX_CTRL_L2C		BIT(20)
+#define TB_LC_SX_CTRL_UPSTREAM		BIT(30)
+#define TB_LC_SX_CTRL_SLP		BIT(31)
 
 #endif
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
new file mode 100644
index 000000000000..31d0234837e4
--- /dev/null
+++ b/drivers/thunderbolt/tunnel.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - Tunneling support
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2019, Intel Corporation
+ */
+
+#include <linux/slab.h>
+#include <linux/list.h>
+
+#include "tunnel.h"
+#include "tb.h"
+
+/* PCIe adapters use always HopID of 8 for both directions */
+#define TB_PCI_HOPID			8
+
+#define TB_PCI_PATH_DOWN		0
+#define TB_PCI_PATH_UP			1
+
+/* DP adapters use HopID 8 for AUX and 9 for Video */
+#define TB_DP_AUX_TX_HOPID		8
+#define TB_DP_AUX_RX_HOPID		8
+#define TB_DP_VIDEO_HOPID		9
+
+#define TB_DP_VIDEO_PATH_OUT		0
+#define TB_DP_AUX_PATH_OUT		1
+#define TB_DP_AUX_PATH_IN		2
+
+#define TB_DMA_PATH_OUT			0
+#define TB_DMA_PATH_IN			1
+
+static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA" };
+
+#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
+	do {                                                            \
+		struct tb_tunnel *__tunnel = (tunnel);                  \
+		level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
+		      tb_route(__tunnel->src_port->sw),                 \
+		      __tunnel->src_port->port,                         \
+		      tb_route(__tunnel->dst_port->sw),                 \
+		      __tunnel->dst_port->port,                         \
+		      tb_tunnel_names[__tunnel->type],			\
+		      ## arg);                                          \
+	} while (0)
+
+#define tb_tunnel_WARN(tunnel, fmt, arg...) \
+	__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
+#define tb_tunnel_warn(tunnel, fmt, arg...) \
+	__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
+#define tb_tunnel_info(tunnel, fmt, arg...) \
+	__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
+#define tb_tunnel_dbg(tunnel, fmt, arg...) \
+	__TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
+
+static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
+					 enum tb_tunnel_type type)
+{
+	struct tb_tunnel *tunnel;
+
+	tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
+	if (!tunnel)
+		return NULL;
+
+	tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
+	if (!tunnel->paths) {
+		tb_tunnel_free(tunnel);
+		return NULL;
+	}
+
+	INIT_LIST_HEAD(&tunnel->list);
+	tunnel->tb = tb;
+	tunnel->npaths = npaths;
+	tunnel->type = type;
+
+	return tunnel;
+}
+
+static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
+{
+	int res;
+
+	res = tb_pci_port_enable(tunnel->src_port, activate);
+	if (res)
+		return res;
+
+	if (tb_port_is_pcie_up(tunnel->dst_port))
+		return tb_pci_port_enable(tunnel->dst_port, activate);
+
+	return 0;
+}
+
+static void tb_pci_init_path(struct tb_path *path)
+{
+	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
+	path->egress_shared_buffer = TB_PATH_NONE;
+	path->ingress_fc_enable = TB_PATH_ALL;
+	path->ingress_shared_buffer = TB_PATH_NONE;
+	path->priority = 3;
+	path->weight = 1;
+	path->drop_packages = 0;
+	path->nfc_credits = 0;
+	path->hops[0].initial_credits = 7;
+	path->hops[1].initial_credits = 16;
+}
+
+/**
+ * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
+ * @tb: Pointer to the domain structure
+ * @down: PCIe downstream adapter
+ *
+ * If @down adapter is active, follows the tunnel to the PCIe upstream
+ * adapter and back. Returns the discovered tunnel or %NULL if there was
+ * no tunnel.
+ */
+struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down)
+{
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	if (!tb_pci_port_is_enabled(down))
+		return NULL;
+
+	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
+	if (!tunnel)
+		return NULL;
+
+	tunnel->activate = tb_pci_activate;
+	tunnel->src_port = down;
+
+	/*
+	 * Discover both paths even if they are not complete. We will
+	 * clean them up by calling tb_tunnel_deactivate() below in that
+	 * case.
+	 */
+	path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
+				&tunnel->dst_port, "PCIe Up");
+	if (!path) {
+		/* Just disable the downstream port */
+		tb_pci_port_enable(down, false);
+		goto err_free;
+	}
+	tunnel->paths[TB_PCI_PATH_UP] = path;
+	tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]);
+
+	path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
+				"PCIe Down");
+	if (!path)
+		goto err_deactivate;
+	tunnel->paths[TB_PCI_PATH_DOWN] = path;
+	tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]);
+
+	/* Validate that the tunnel is complete */
+	if (!tb_port_is_pcie_up(tunnel->dst_port)) {
+		tb_port_warn(tunnel->dst_port,
+			     "path does not end on a PCIe adapter, cleaning up\n");
+		goto err_deactivate;
+	}
+
+	if (down != tunnel->src_port) {
+		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
+		goto err_deactivate;
+	}
+
+	if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
+		tb_tunnel_warn(tunnel,
+			       "tunnel is not fully activated, cleaning up\n");
+		goto err_deactivate;
+	}
+
+	tb_tunnel_dbg(tunnel, "discovered\n");
+	return tunnel;
+
+err_deactivate:
+	tb_tunnel_deactivate(tunnel);
+err_free:
+	tb_tunnel_free(tunnel);
+
+	return NULL;
+}
+
+/**
+ * tb_tunnel_alloc_pci() - allocate a pci tunnel
+ * @tb: Pointer to the domain structure
+ * @up: PCIe upstream adapter port
+ * @down: PCIe downstream adapter port
+ *
+ * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
+ * TB_TYPE_PCIE_DOWN.
+ *
+ * Return: Returns a tb_tunnel on success or NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
+				      struct tb_port *down)
+{
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
+	if (!tunnel)
+		return NULL;
+
+	tunnel->activate = tb_pci_activate;
+	tunnel->src_port = down;
+	tunnel->dst_port = up;
+
+	path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
+			     "PCIe Down");
+	if (!path) {
+		tb_tunnel_free(tunnel);
+		return NULL;
+	}
+	tb_pci_init_path(path);
+	tunnel->paths[TB_PCI_PATH_UP] = path;
+
+	path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
+			     "PCIe Up");
+	if (!path) {
+		tb_tunnel_free(tunnel);
+		return NULL;
+	}
+	tb_pci_init_path(path);
+	tunnel->paths[TB_PCI_PATH_DOWN] = path;
+
+	return tunnel;
+}
+
+static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
+{
+	struct tb_port *out = tunnel->dst_port;
+	struct tb_port *in = tunnel->src_port;
+	u32 in_dp_cap, out_dp_cap;
+	int ret;
+
+	/*
+	 * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
+	 * newer generation hardware.
+	 */
+	if (in->sw->generation < 2 || out->sw->generation < 2)
+		return 0;
+
+	/* Read both DP_LOCAL_CAP registers */
+	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
+			   in->cap_adap + TB_DP_LOCAL_CAP, 1);
+	if (ret)
+		return ret;
+
+	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
+			   out->cap_adap + TB_DP_LOCAL_CAP, 1);
+	if (ret)
+		return ret;
+
+	/* Write IN local caps to OUT remote caps */
+	ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
+			    out->cap_adap + TB_DP_REMOTE_CAP, 1);
+	if (ret)
+		return ret;
+
+	return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
+			     in->cap_adap + TB_DP_REMOTE_CAP, 1);
+}
+
+static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
+{
+	int ret;
+
+	if (active) {
+		struct tb_path **paths;
+		int last;
+
+		paths = tunnel->paths;
+		last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
+
+		tb_dp_port_set_hops(tunnel->src_port,
+			paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
+			paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
+			paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
+
+		tb_dp_port_set_hops(tunnel->dst_port,
+			paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
+			paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
+			paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
+	} else {
+		tb_dp_port_hpd_clear(tunnel->src_port);
+		tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
+		if (tb_port_is_dpout(tunnel->dst_port))
+			tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
+	}
+
+	ret = tb_dp_port_enable(tunnel->src_port, active);
+	if (ret)
+		return ret;
+
+	if (tb_port_is_dpout(tunnel->dst_port))
+		return tb_dp_port_enable(tunnel->dst_port, active);
+
+	return 0;
+}
+
+static void tb_dp_init_aux_path(struct tb_path *path)
+{
+	int i;
+
+	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
+	path->egress_shared_buffer = TB_PATH_NONE;
+	path->ingress_fc_enable = TB_PATH_ALL;
+	path->ingress_shared_buffer = TB_PATH_NONE;
+	path->priority = 2;
+	path->weight = 1;
+
+	for (i = 0; i < path->path_length; i++)
+		path->hops[i].initial_credits = 1;
+}
+
+static void tb_dp_init_video_path(struct tb_path *path, bool discover)
+{
+	u32 nfc_credits = path->hops[0].in_port->config.nfc_credits;
+
+	path->egress_fc_enable = TB_PATH_NONE;
+	path->egress_shared_buffer = TB_PATH_NONE;
+	path->ingress_fc_enable = TB_PATH_NONE;
+	path->ingress_shared_buffer = TB_PATH_NONE;
+	path->priority = 1;
+	path->weight = 1;
+
+	if (discover) {
+		path->nfc_credits = nfc_credits & TB_PORT_NFC_CREDITS_MASK;
+	} else {
+		u32 max_credits;
+
+		max_credits = (nfc_credits & TB_PORT_MAX_CREDITS_MASK) >>
+			TB_PORT_MAX_CREDITS_SHIFT;
+		/* Leave some credits for AUX path */
+		path->nfc_credits = min(max_credits - 2, 12U);
+	}
+}
+
+/**
+ * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
+ * @tb: Pointer to the domain structure
+ * @in: DP in adapter
+ *
+ * If @in adapter is active, follows the tunnel to the DP out adapter
+ * and back. Returns the discovered tunnel or %NULL if there was no
+ * tunnel.
+ *
+ * Return: DP tunnel or %NULL if no tunnel found.
+ */
+struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in)
+{
+	struct tb_tunnel *tunnel;
+	struct tb_port *port;
+	struct tb_path *path;
+
+	if (!tb_dp_port_is_enabled(in))
+		return NULL;
+
+	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
+	if (!tunnel)
+		return NULL;
+
+	tunnel->init = tb_dp_xchg_caps;
+	tunnel->activate = tb_dp_activate;
+	tunnel->src_port = in;
+
+	path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
+				&tunnel->dst_port, "Video");
+	if (!path) {
+		/* Just disable the DP IN port */
+		tb_dp_port_enable(in, false);
+		goto err_free;
+	}
+	tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
+	tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true);
+
+	path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX");
+	if (!path)
+		goto err_deactivate;
+	tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
+	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
+
+	path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
+				&port, "AUX RX");
+	if (!path)
+		goto err_deactivate;
+	tunnel->paths[TB_DP_AUX_PATH_IN] = path;
+	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
+
+	/* Validate that the tunnel is complete */
+	if (!tb_port_is_dpout(tunnel->dst_port)) {
+		tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
+		goto err_deactivate;
+	}
+
+	if (!tb_dp_port_is_enabled(tunnel->dst_port))
+		goto err_deactivate;
+
+	if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
+		goto err_deactivate;
+
+	if (port != tunnel->src_port) {
+		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
+		goto err_deactivate;
+	}
+
+	tb_tunnel_dbg(tunnel, "discovered\n");
+	return tunnel;
+
+err_deactivate:
+	tb_tunnel_deactivate(tunnel);
+err_free:
+	tb_tunnel_free(tunnel);
+
+	return NULL;
+}
+
+/**
+ * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
+ * @tb: Pointer to the domain structure
+ * @in: DP in adapter port
+ * @out: DP out adapter port
+ *
+ * Allocates a tunnel between @in and @out that is capable of tunneling
+ * Display Port traffic.
+ *
+ * Return: Returns a tb_tunnel on success or NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
+				     struct tb_port *out)
+{
+	struct tb_tunnel *tunnel;
+	struct tb_path **paths;
+	struct tb_path *path;
+
+	if (WARN_ON(!in->cap_adap || !out->cap_adap))
+		return NULL;
+
+	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
+	if (!tunnel)
+		return NULL;
+
+	tunnel->init = tb_dp_xchg_caps;
+	tunnel->activate = tb_dp_activate;
+	tunnel->src_port = in;
+	tunnel->dst_port = out;
+
+	paths = tunnel->paths;
+
+	path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
+			     1, "Video");
+	if (!path)
+		goto err_free;
+	tb_dp_init_video_path(path, false);
+	paths[TB_DP_VIDEO_PATH_OUT] = path;
+
+	path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
+			     TB_DP_AUX_TX_HOPID, 1, "AUX TX");
+	if (!path)
+		goto err_free;
+	tb_dp_init_aux_path(path);
+	paths[TB_DP_AUX_PATH_OUT] = path;
+
+	path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
+			     TB_DP_AUX_RX_HOPID, 1, "AUX RX");
+	if (!path)
+		goto err_free;
+	tb_dp_init_aux_path(path);
+	paths[TB_DP_AUX_PATH_IN] = path;
+
+	return tunnel;
+
+err_free:
+	tb_tunnel_free(tunnel);
+	return NULL;
+}
+
+static u32 tb_dma_credits(struct tb_port *nhi)
+{
+	u32 max_credits;
+
+	max_credits = (nhi->config.nfc_credits & TB_PORT_MAX_CREDITS_MASK) >>
+		TB_PORT_MAX_CREDITS_SHIFT;
+	return min(max_credits, 13U);
+}
+
+static int tb_dma_activate(struct tb_tunnel *tunnel, bool active)
+{
+	struct tb_port *nhi = tunnel->src_port;
+	u32 credits;
+
+	credits = active ? tb_dma_credits(nhi) : 0;
+	return tb_port_set_initial_credits(nhi, credits);
+}
+
+static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
+			     unsigned int efc, u32 credits)
+{
+	int i;
+
+	path->egress_fc_enable = efc;
+	path->ingress_fc_enable = TB_PATH_ALL;
+	path->egress_shared_buffer = TB_PATH_NONE;
+	path->ingress_shared_buffer = isb;
+	path->priority = 5;
+	path->weight = 1;
+	path->clear_fc = true;
+
+	for (i = 0; i < path->path_length; i++)
+		path->hops[i].initial_credits = credits;
+}
+
+/**
+ * tb_tunnel_alloc_dma() - allocate a DMA tunnel
+ * @tb: Pointer to the domain structure
+ * @nhi: Host controller port
+ * @dst: Destination null port which the other domain is connected to
+ * @transmit_ring: NHI ring number used to send packets towards the
+ *		   other domain
+ * @transmit_path: HopID used for transmitting packets
+ * @receive_ring: NHI ring number used to receive packets from the
+ *		  other domain
+ * @reveive_path: HopID used for receiving packets
+ *
+ * Return: Returns a tb_tunnel on success or NULL on failure.
+ */
+struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
+				      struct tb_port *dst, int transmit_ring,
+				      int transmit_path, int receive_ring,
+				      int receive_path)
+{
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+	u32 credits;
+
+	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_DMA);
+	if (!tunnel)
+		return NULL;
+
+	tunnel->activate = tb_dma_activate;
+	tunnel->src_port = nhi;
+	tunnel->dst_port = dst;
+
+	credits = tb_dma_credits(nhi);
+
+	path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0, "DMA RX");
+	if (!path) {
+		tb_tunnel_free(tunnel);
+		return NULL;
+	}
+	tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
+			 credits);
+	tunnel->paths[TB_DMA_PATH_IN] = path;
+
+	path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0, "DMA TX");
+	if (!path) {
+		tb_tunnel_free(tunnel);
+		return NULL;
+	}
+	tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
+	tunnel->paths[TB_DMA_PATH_OUT] = path;
+
+	return tunnel;
+}
+
+/**
+ * tb_tunnel_free() - free a tunnel
+ * @tunnel: Tunnel to be freed
+ *
+ * Frees a tunnel. The tunnel does not need to be deactivated.
+ */
+void tb_tunnel_free(struct tb_tunnel *tunnel)
+{
+	int i;
+
+	if (!tunnel)
+		return;
+
+	for (i = 0; i < tunnel->npaths; i++) {
+		if (tunnel->paths[i])
+			tb_path_free(tunnel->paths[i]);
+	}
+
+	kfree(tunnel->paths);
+	kfree(tunnel);
+}
+
+/**
+ * tb_tunnel_is_invalid - check whether an activated path is still valid
+ * @tunnel: Tunnel to check
+ */
+bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
+{
+	int i;
+
+	for (i = 0; i < tunnel->npaths; i++) {
+		WARN_ON(!tunnel->paths[i]->activated);
+		if (tb_path_is_invalid(tunnel->paths[i]))
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * tb_tunnel_restart() - activate a tunnel after a hardware reset
+ * @tunnel: Tunnel to restart
+ *
+ * Return: 0 on success and negative errno in case if failure
+ */
+int tb_tunnel_restart(struct tb_tunnel *tunnel)
+{
+	int res, i;
+
+	tb_tunnel_dbg(tunnel, "activating\n");
+
+	/*
+	 * Make sure all paths are properly disabled before enabling
+	 * them again.
+	 */
+	for (i = 0; i < tunnel->npaths; i++) {
+		if (tunnel->paths[i]->activated) {
+			tb_path_deactivate(tunnel->paths[i]);
+			tunnel->paths[i]->activated = false;
+		}
+	}
+
+	if (tunnel->init) {
+		res = tunnel->init(tunnel);
+		if (res)
+			return res;
+	}
+
+	for (i = 0; i < tunnel->npaths; i++) {
+		res = tb_path_activate(tunnel->paths[i]);
+		if (res)
+			goto err;
+	}
+
+	if (tunnel->activate) {
+		res = tunnel->activate(tunnel, true);
+		if (res)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	tb_tunnel_warn(tunnel, "activation failed\n");
+	tb_tunnel_deactivate(tunnel);
+	return res;
+}
+
+/**
+ * tb_tunnel_activate() - activate a tunnel
+ * @tunnel: Tunnel to activate
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_tunnel_activate(struct tb_tunnel *tunnel)
+{
+	int i;
+
+	for (i = 0; i < tunnel->npaths; i++) {
+		if (tunnel->paths[i]->activated) {
+			tb_tunnel_WARN(tunnel,
+				       "trying to activate an already activated tunnel\n");
+			return -EINVAL;
+		}
+	}
+
+	return tb_tunnel_restart(tunnel);
+}
+
+/**
+ * tb_tunnel_deactivate() - deactivate a tunnel
+ * @tunnel: Tunnel to deactivate
+ */
+void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
+{
+	int i;
+
+	tb_tunnel_dbg(tunnel, "deactivating\n");
+
+	if (tunnel->activate)
+		tunnel->activate(tunnel, false);
+
+	for (i = 0; i < tunnel->npaths; i++) {
+		if (tunnel->paths[i] && tunnel->paths[i]->activated)
+			tb_path_deactivate(tunnel->paths[i]);
+	}
+}
diff --git a/drivers/thunderbolt/tunnel.h b/drivers/thunderbolt/tunnel.h
new file mode 100644
index 000000000000..c68bbcd3a62c
--- /dev/null
+++ b/drivers/thunderbolt/tunnel.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Thunderbolt driver - Tunneling support
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2019, Intel Corporation
+ */
+
+#ifndef TB_TUNNEL_H_
+#define TB_TUNNEL_H_
+
+#include "tb.h"
+
+enum tb_tunnel_type {
+	TB_TUNNEL_PCI,
+	TB_TUNNEL_DP,
+	TB_TUNNEL_DMA,
+};
+
+/**
+ * struct tb_tunnel - Tunnel between two ports
+ * @tb: Pointer to the domain
+ * @src_port: Source port of the tunnel
+ * @dst_port: Destination port of the tunnel. For discovered incomplete
+ *	      tunnels may be %NULL or null adapter port instead.
+ * @paths: All paths required by the tunnel
+ * @npaths: Number of paths in @paths
+ * @init: Optional tunnel specific initialization
+ * @activate: Optional tunnel specific activation/deactivation
+ * @list: Tunnels are linked using this field
+ * @type: Type of the tunnel
+ */
+struct tb_tunnel {
+	struct tb *tb;
+	struct tb_port *src_port;
+	struct tb_port *dst_port;
+	struct tb_path **paths;
+	size_t npaths;
+	int (*init)(struct tb_tunnel *tunnel);
+	int (*activate)(struct tb_tunnel *tunnel, bool activate);
+	struct list_head list;
+	enum tb_tunnel_type type;
+};
+
+struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down);
+struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
+				      struct tb_port *down);
+struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in);
+struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
+				     struct tb_port *out);
+struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
+				      struct tb_port *dst, int transmit_ring,
+				      int transmit_path, int receive_ring,
+				      int receive_path);
+
+void tb_tunnel_free(struct tb_tunnel *tunnel);
+int tb_tunnel_activate(struct tb_tunnel *tunnel);
+int tb_tunnel_restart(struct tb_tunnel *tunnel);
+void tb_tunnel_deactivate(struct tb_tunnel *tunnel);
+bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel);
+
+static inline bool tb_tunnel_is_pci(const struct tb_tunnel *tunnel)
+{
+	return tunnel->type == TB_TUNNEL_PCI;
+}
+
+static inline bool tb_tunnel_is_dp(const struct tb_tunnel *tunnel)
+{
+	return tunnel->type == TB_TUNNEL_DP;
+}
+
+static inline bool tb_tunnel_is_dma(const struct tb_tunnel *tunnel)
+{
+	return tunnel->type == TB_TUNNEL_DMA;
+}
+
+#endif
+
diff --git a/drivers/thunderbolt/tunnel_pci.c b/drivers/thunderbolt/tunnel_pci.c
deleted file mode 100644
index 0637537ea53f..000000000000
--- a/drivers/thunderbolt/tunnel_pci.c
+++ /dev/null
@@ -1,226 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Thunderbolt Cactus Ridge driver - PCIe tunnel
- *
- * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
- */
-
-#include <linux/slab.h>
-#include <linux/list.h>
-
-#include "tunnel_pci.h"
-#include "tb.h"
-
-#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
-	do {                                                            \
-		struct tb_pci_tunnel *__tunnel = (tunnel);              \
-		level(__tunnel->tb, "%llx:%x <-> %llx:%x (PCI): " fmt,  \
-		      tb_route(__tunnel->down_port->sw),                \
-		      __tunnel->down_port->port,                        \
-		      tb_route(__tunnel->up_port->sw),                  \
-		      __tunnel->up_port->port,                          \
-		      ## arg);                                          \
-	} while (0)
-
-#define tb_tunnel_WARN(tunnel, fmt, arg...) \
-	__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
-#define tb_tunnel_warn(tunnel, fmt, arg...) \
-	__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
-#define tb_tunnel_info(tunnel, fmt, arg...) \
-	__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
-
-static void tb_pci_init_path(struct tb_path *path)
-{
-	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
-	path->egress_shared_buffer = TB_PATH_NONE;
-	path->ingress_fc_enable = TB_PATH_ALL;
-	path->ingress_shared_buffer = TB_PATH_NONE;
-	path->priority = 3;
-	path->weight = 1;
-	path->drop_packages = 0;
-	path->nfc_credits = 0;
-}
-
-/**
- * tb_pci_alloc() - allocate a pci tunnel
- *
- * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
- * TB_TYPE_PCIE_DOWN.
- *
- * Currently only paths consisting of two hops are supported (that is the
- * ports must be on "adjacent" switches).
- *
- * The paths are hard-coded to use hop 8 (the only working hop id available on
- * my thunderbolt devices). Therefore at most ONE path per device may be
- * activated.
- *
- * Return: Returns a tb_pci_tunnel on success or NULL on failure.
- */
-struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up,
-				   struct tb_port *down)
-{
-	struct tb_pci_tunnel *tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
-	if (!tunnel)
-		goto err;
-	tunnel->tb = tb;
-	tunnel->down_port = down;
-	tunnel->up_port = up;
-	INIT_LIST_HEAD(&tunnel->list);
-	tunnel->path_to_up = tb_path_alloc(up->sw->tb, 2);
-	if (!tunnel->path_to_up)
-		goto err;
-	tunnel->path_to_down = tb_path_alloc(up->sw->tb, 2);
-	if (!tunnel->path_to_down)
-		goto err;
-	tb_pci_init_path(tunnel->path_to_up);
-	tb_pci_init_path(tunnel->path_to_down);
-
-	tunnel->path_to_up->hops[0].in_port = down;
-	tunnel->path_to_up->hops[0].in_hop_index = 8;
-	tunnel->path_to_up->hops[0].in_counter_index = -1;
-	tunnel->path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote;
-	tunnel->path_to_up->hops[0].next_hop_index = 8;
-
-	tunnel->path_to_up->hops[1].in_port = tb_upstream_port(up->sw);
-	tunnel->path_to_up->hops[1].in_hop_index = 8;
-	tunnel->path_to_up->hops[1].in_counter_index = -1;
-	tunnel->path_to_up->hops[1].out_port = up;
-	tunnel->path_to_up->hops[1].next_hop_index = 8;
-
-	tunnel->path_to_down->hops[0].in_port = up;
-	tunnel->path_to_down->hops[0].in_hop_index = 8;
-	tunnel->path_to_down->hops[0].in_counter_index = -1;
-	tunnel->path_to_down->hops[0].out_port = tb_upstream_port(up->sw);
-	tunnel->path_to_down->hops[0].next_hop_index = 8;
-
-	tunnel->path_to_down->hops[1].in_port =
-		tb_upstream_port(up->sw)->remote;
-	tunnel->path_to_down->hops[1].in_hop_index = 8;
-	tunnel->path_to_down->hops[1].in_counter_index = -1;
-	tunnel->path_to_down->hops[1].out_port = down;
-	tunnel->path_to_down->hops[1].next_hop_index = 8;
-	return tunnel;
-
-err:
-	if (tunnel) {
-		if (tunnel->path_to_down)
-			tb_path_free(tunnel->path_to_down);
-		if (tunnel->path_to_up)
-			tb_path_free(tunnel->path_to_up);
-		kfree(tunnel);
-	}
-	return NULL;
-}
-
-/**
- * tb_pci_free() - free a tunnel
- *
- * The tunnel must have been deactivated.
- */
-void tb_pci_free(struct tb_pci_tunnel *tunnel)
-{
-	if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
-		tb_tunnel_WARN(tunnel, "trying to free an activated tunnel\n");
-		return;
-	}
-	tb_path_free(tunnel->path_to_up);
-	tb_path_free(tunnel->path_to_down);
-	kfree(tunnel);
-}
-
-/**
- * tb_pci_is_invalid - check whether an activated path is still valid
- */
-bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel)
-{
-	WARN_ON(!tunnel->path_to_up->activated);
-	WARN_ON(!tunnel->path_to_down->activated);
-
-	return tb_path_is_invalid(tunnel->path_to_up)
-	       || tb_path_is_invalid(tunnel->path_to_down);
-}
-
-/**
- * tb_pci_port_active() - activate/deactivate PCI capability
- *
- * Return: Returns 0 on success or an error code on failure.
- */
-static int tb_pci_port_active(struct tb_port *port, bool active)
-{
-	u32 word = active ? 0x80000000 : 0x0;
-	int cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
-	if (cap < 0) {
-		tb_port_warn(port, "TB_PORT_CAP_ADAP not found: %d\n", cap);
-		return cap;
-	}
-	return tb_port_write(port, &word, TB_CFG_PORT, cap, 1);
-}
-
-/**
- * tb_pci_restart() - activate a tunnel after a hardware reset
- */
-int tb_pci_restart(struct tb_pci_tunnel *tunnel)
-{
-	int res;
-	tunnel->path_to_up->activated = false;
-	tunnel->path_to_down->activated = false;
-
-	tb_tunnel_info(tunnel, "activating\n");
-
-	res = tb_path_activate(tunnel->path_to_up);
-	if (res)
-		goto err;
-	res = tb_path_activate(tunnel->path_to_down);
-	if (res)
-		goto err;
-
-	res = tb_pci_port_active(tunnel->down_port, true);
-	if (res)
-		goto err;
-
-	res = tb_pci_port_active(tunnel->up_port, true);
-	if (res)
-		goto err;
-	return 0;
-err:
-	tb_tunnel_warn(tunnel, "activation failed\n");
-	tb_pci_deactivate(tunnel);
-	return res;
-}
-
-/**
- * tb_pci_activate() - activate a tunnel
- *
- * Return: Returns 0 on success or an error code on failure.
- */
-int tb_pci_activate(struct tb_pci_tunnel *tunnel)
-{
-	if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
-		tb_tunnel_WARN(tunnel,
-			       "trying to activate an already activated tunnel\n");
-		return -EINVAL;
-	}
-
-	return tb_pci_restart(tunnel);
-}
-
-
-
-/**
- * tb_pci_deactivate() - deactivate a tunnel
- */
-void tb_pci_deactivate(struct tb_pci_tunnel *tunnel)
-{
-	tb_tunnel_info(tunnel, "deactivating\n");
-	/*
-	 * TODO: enable reset by writing 0x04000000 to TB_CAP_PCIE + 1 on up
-	 * port. Seems to have no effect?
-	 */
-	tb_pci_port_active(tunnel->up_port, false);
-	tb_pci_port_active(tunnel->down_port, false);
-	if (tunnel->path_to_down->activated)
-		tb_path_deactivate(tunnel->path_to_down);
-	if (tunnel->path_to_up->activated)
-		tb_path_deactivate(tunnel->path_to_up);
-}
-
diff --git a/drivers/thunderbolt/tunnel_pci.h b/drivers/thunderbolt/tunnel_pci.h
deleted file mode 100644
index f9b65fa1fd4d..000000000000
--- a/drivers/thunderbolt/tunnel_pci.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Thunderbolt Cactus Ridge driver - PCIe tunnel
- *
- * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
- */
-
-#ifndef TB_PCI_H_
-#define TB_PCI_H_
-
-#include "tb.h"
-
-struct tb_pci_tunnel {
-	struct tb *tb;
-	struct tb_port *up_port;
-	struct tb_port *down_port;
-	struct tb_path *path_to_up;
-	struct tb_path *path_to_down;
-	struct list_head list;
-};
-
-struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up,
-				   struct tb_port *down);
-void tb_pci_free(struct tb_pci_tunnel *tunnel);
-int tb_pci_activate(struct tb_pci_tunnel *tunnel);
-int tb_pci_restart(struct tb_pci_tunnel *tunnel);
-void tb_pci_deactivate(struct tb_pci_tunnel *tunnel);
-bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel);
-
-#endif
-
diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index e27dd8beb94b..5118d46702d5 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -18,6 +18,7 @@
 #include "tb.h"
 
 #define XDOMAIN_DEFAULT_TIMEOUT			5000 /* ms */
+#define XDOMAIN_UUID_RETRIES			10
 #define XDOMAIN_PROPERTIES_RETRIES		60
 #define XDOMAIN_PROPERTIES_CHANGED_RETRIES	10
 
@@ -222,6 +223,50 @@ static int tb_xdp_handle_error(const struct tb_xdp_header *hdr)
 	return 0;
 }
 
+static int tb_xdp_uuid_request(struct tb_ctl *ctl, u64 route, int retry,
+			       uuid_t *uuid)
+{
+	struct tb_xdp_uuid_response res;
+	struct tb_xdp_uuid req;
+	int ret;
+
+	memset(&req, 0, sizeof(req));
+	tb_xdp_fill_header(&req.hdr, route, retry % 4, UUID_REQUEST,
+			   sizeof(req));
+
+	memset(&res, 0, sizeof(res));
+	ret = __tb_xdomain_request(ctl, &req, sizeof(req),
+				   TB_CFG_PKG_XDOMAIN_REQ, &res, sizeof(res),
+				   TB_CFG_PKG_XDOMAIN_RESP,
+				   XDOMAIN_DEFAULT_TIMEOUT);
+	if (ret)
+		return ret;
+
+	ret = tb_xdp_handle_error(&res.hdr);
+	if (ret)
+		return ret;
+
+	uuid_copy(uuid, &res.src_uuid);
+	return 0;
+}
+
+static int tb_xdp_uuid_response(struct tb_ctl *ctl, u64 route, u8 sequence,
+				const uuid_t *uuid)
+{
+	struct tb_xdp_uuid_response res;
+
+	memset(&res, 0, sizeof(res));
+	tb_xdp_fill_header(&res.hdr, route, sequence, UUID_RESPONSE,
+			   sizeof(res));
+
+	uuid_copy(&res.src_uuid, uuid);
+	res.src_route_hi = upper_32_bits(route);
+	res.src_route_lo = lower_32_bits(route);
+
+	return __tb_xdomain_response(ctl, &res, sizeof(res),
+				     TB_CFG_PKG_XDOMAIN_RESP);
+}
+
 static int tb_xdp_error_response(struct tb_ctl *ctl, u64 route, u8 sequence,
 				 enum tb_xdp_error error)
 {
@@ -512,7 +557,14 @@ static void tb_xdp_handle_request(struct work_struct *work)
 		break;
 	}
 
+	case UUID_REQUEST_OLD:
+	case UUID_REQUEST:
+		ret = tb_xdp_uuid_response(ctl, route, sequence, uuid);
+		break;
+
 	default:
+		tb_xdp_error_response(ctl, route, sequence,
+				      ERROR_NOT_SUPPORTED);
 		break;
 	}
 
@@ -524,9 +576,11 @@ static void tb_xdp_handle_request(struct work_struct *work)
 out:
 	kfree(xw->pkg);
 	kfree(xw);
+
+	tb_domain_put(tb);
 }
 
-static void
+static bool
 tb_xdp_schedule_request(struct tb *tb, const struct tb_xdp_header *hdr,
 			size_t size)
 {
@@ -534,13 +588,18 @@ tb_xdp_schedule_request(struct tb *tb, const struct tb_xdp_header *hdr,
 
 	xw = kmalloc(sizeof(*xw), GFP_KERNEL);
 	if (!xw)
-		return;
+		return false;
 
 	INIT_WORK(&xw->work, tb_xdp_handle_request);
 	xw->pkg = kmemdup(hdr, size, GFP_KERNEL);
-	xw->tb = tb;
+	if (!xw->pkg) {
+		kfree(xw);
+		return false;
+	}
+	xw->tb = tb_domain_get(tb);
 
-	queue_work(tb->wq, &xw->work);
+	schedule_work(&xw->work);
+	return true;
 }
 
 /**
@@ -740,6 +799,7 @@ static void enumerate_services(struct tb_xdomain *xd)
 	struct tb_service *svc;
 	struct tb_property *p;
 	struct device *dev;
+	int id;
 
 	/*
 	 * First remove all services that are not available anymore in
@@ -768,7 +828,12 @@ static void enumerate_services(struct tb_xdomain *xd)
 			break;
 		}
 
-		svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
+		id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
+		if (id < 0) {
+			kfree(svc);
+			break;
+		}
+		svc->id = id;
 		svc->dev.bus = &tb_bus_type;
 		svc->dev.type = &tb_service_type;
 		svc->dev.parent = &xd->dev;
@@ -826,6 +891,55 @@ static void tb_xdomain_restore_paths(struct tb_xdomain *xd)
 	}
 }
 
+static void tb_xdomain_get_uuid(struct work_struct *work)
+{
+	struct tb_xdomain *xd = container_of(work, typeof(*xd),
+					     get_uuid_work.work);
+	struct tb *tb = xd->tb;
+	uuid_t uuid;
+	int ret;
+
+	ret = tb_xdp_uuid_request(tb->ctl, xd->route, xd->uuid_retries, &uuid);
+	if (ret < 0) {
+		if (xd->uuid_retries-- > 0) {
+			queue_delayed_work(xd->tb->wq, &xd->get_uuid_work,
+					   msecs_to_jiffies(100));
+		} else {
+			dev_dbg(&xd->dev, "failed to read remote UUID\n");
+		}
+		return;
+	}
+
+	if (uuid_equal(&uuid, xd->local_uuid)) {
+		dev_dbg(&xd->dev, "intra-domain loop detected\n");
+		return;
+	}
+
+	/*
+	 * If the UUID is different, there is another domain connected
+	 * so mark this one unplugged and wait for the connection
+	 * manager to replace it.
+	 */
+	if (xd->remote_uuid && !uuid_equal(&uuid, xd->remote_uuid)) {
+		dev_dbg(&xd->dev, "remote UUID is different, unplugging\n");
+		xd->is_unplugged = true;
+		return;
+	}
+
+	/* First time fill in the missing UUID */
+	if (!xd->remote_uuid) {
+		xd->remote_uuid = kmemdup(&uuid, sizeof(uuid_t), GFP_KERNEL);
+		if (!xd->remote_uuid)
+			return;
+	}
+
+	/* Now we can start the normal properties exchange */
+	queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
+			   msecs_to_jiffies(100));
+	queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
+			   msecs_to_jiffies(1000));
+}
+
 static void tb_xdomain_get_properties(struct work_struct *work)
 {
 	struct tb_xdomain *xd = container_of(work, typeof(*xd),
@@ -1032,21 +1146,29 @@ static void tb_xdomain_release(struct device *dev)
 
 static void start_handshake(struct tb_xdomain *xd)
 {
+	xd->uuid_retries = XDOMAIN_UUID_RETRIES;
 	xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;
 	xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;
 
-	/* Start exchanging properties with the other host */
-	queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
-			   msecs_to_jiffies(100));
-	queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
-			   msecs_to_jiffies(1000));
+	if (xd->needs_uuid) {
+		queue_delayed_work(xd->tb->wq, &xd->get_uuid_work,
+				   msecs_to_jiffies(100));
+	} else {
+		/* Start exchanging properties with the other host */
+		queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
+				   msecs_to_jiffies(100));
+		queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
+				   msecs_to_jiffies(1000));
+	}
 }
 
 static void stop_handshake(struct tb_xdomain *xd)
 {
+	xd->uuid_retries = 0;
 	xd->properties_retries = 0;
 	xd->properties_changed_retries = 0;
 
+	cancel_delayed_work_sync(&xd->get_uuid_work);
 	cancel_delayed_work_sync(&xd->get_properties_work);
 	cancel_delayed_work_sync(&xd->properties_changed_work);
 }
@@ -1089,7 +1211,7 @@ EXPORT_SYMBOL_GPL(tb_xdomain_type);
  *	    other domain is reached).
  * @route: Route string used to reach the other domain
  * @local_uuid: Our local domain UUID
- * @remote_uuid: UUID of the other domain
+ * @remote_uuid: UUID of the other domain (optional)
  *
  * Allocates new XDomain structure and returns pointer to that. The
  * object must be released by calling tb_xdomain_put().
@@ -1108,6 +1230,7 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
 	xd->route = route;
 	ida_init(&xd->service_ids);
 	mutex_init(&xd->lock);
+	INIT_DELAYED_WORK(&xd->get_uuid_work, tb_xdomain_get_uuid);
 	INIT_DELAYED_WORK(&xd->get_properties_work, tb_xdomain_get_properties);
 	INIT_DELAYED_WORK(&xd->properties_changed_work,
 			  tb_xdomain_properties_changed);
@@ -1116,9 +1239,14 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
 	if (!xd->local_uuid)
 		goto err_free;
 
-	xd->remote_uuid = kmemdup(remote_uuid, sizeof(uuid_t), GFP_KERNEL);
-	if (!xd->remote_uuid)
-		goto err_free_local_uuid;
+	if (remote_uuid) {
+		xd->remote_uuid = kmemdup(remote_uuid, sizeof(uuid_t),
+					  GFP_KERNEL);
+		if (!xd->remote_uuid)
+			goto err_free_local_uuid;
+	} else {
+		xd->needs_uuid = true;
+	}
 
 	device_initialize(&xd->dev);
 	xd->dev.parent = get_device(parent);
@@ -1282,14 +1410,12 @@ static struct tb_xdomain *switch_find_xdomain(struct tb_switch *sw,
 		struct tb_port *port = &sw->ports[i];
 		struct tb_xdomain *xd;
 
-		if (tb_is_upstream_port(port))
-			continue;
-
 		if (port->xdomain) {
 			xd = port->xdomain;
 
 			if (lookup->uuid) {
-				if (uuid_equal(xd->remote_uuid, lookup->uuid))
+				if (xd->remote_uuid &&
+				    uuid_equal(xd->remote_uuid, lookup->uuid))
 					return xd;
 			} else if (lookup->link &&
 				   lookup->link == xd->link &&
@@ -1299,7 +1425,7 @@ static struct tb_xdomain *switch_find_xdomain(struct tb_switch *sw,
 				   lookup->route == xd->route) {
 				return xd;
 			}
-		} else if (port->remote) {
+		} else if (tb_port_has_remote(port)) {
 			xd = switch_find_xdomain(port->remote->sw, lookup);
 			if (xd)
 				return xd;
@@ -1416,10 +1542,8 @@ bool tb_xdomain_handle_request(struct tb *tb, enum tb_cfg_pkg_type type,
 	 * handlers in turn.
 	 */
 	if (uuid_equal(&hdr->uuid, &tb_xdp_uuid)) {
-		if (type == TB_CFG_PKG_XDOMAIN_REQ) {
-			tb_xdp_schedule_request(tb, hdr, size);
-			return true;
-		}
+		if (type == TB_CFG_PKG_XDOMAIN_REQ)
+			return tb_xdp_schedule_request(tb, hdr, size);
 		return false;
 	}
 
diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
index bf6ec83e60ee..2d7e012db03f 100644
--- a/include/linux/thunderbolt.h
+++ b/include/linux/thunderbolt.h
@@ -181,6 +181,8 @@ void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
  * @device_name: Name of the device (or %NULL if not known)
  * @is_unplugged: The XDomain is unplugged
  * @resume: The XDomain is being resumed
+ * @needs_uuid: If the XDomain does not have @remote_uuid it will be
+ *		queried first
  * @transmit_path: HopID which the remote end expects us to transmit
  * @transmit_ring: Local ring (hop) where outgoing packets are pushed
  * @receive_path: HopID which we expect the remote end to transmit
@@ -189,6 +191,9 @@ void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
  * @properties: Properties exported by the remote domain
  * @property_block_gen: Generation of @properties
  * @properties_lock: Lock protecting @properties.
+ * @get_uuid_work: Work used to retrieve @remote_uuid
+ * @uuid_retries: Number of times left @remote_uuid is requested before
+ *		  giving up
  * @get_properties_work: Work used to get remote domain properties
  * @properties_retries: Number of times left to read properties
  * @properties_changed_work: Work used to notify the remote domain that
@@ -220,6 +225,7 @@ struct tb_xdomain {
 	const char *device_name;
 	bool is_unplugged;
 	bool resume;
+	bool needs_uuid;
 	u16 transmit_path;
 	u16 transmit_ring;
 	u16 receive_path;
@@ -227,6 +233,8 @@ struct tb_xdomain {
 	struct ida service_ids;
 	struct tb_property_dir *properties;
 	u32 property_block_gen;
+	struct delayed_work get_uuid_work;
+	int uuid_retries;
 	struct delayed_work get_properties_work;
 	int properties_retries;
 	struct delayed_work properties_changed_work;