Merge tag 'thunderbolt-for-v5.2' of...

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
  ...

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);

drivers/thunderbolt/Makefile

 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

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;

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);
 }
 

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

drivers/thunderbolt/lc.c

+// 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;
+}

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

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);

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;

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

drivers/thunderbolt/tunnel.h

+/* 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
+

drivers/thunderbolt/tunnel_pci.c

-// 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);
-}
-

drivers/thunderbolt/tunnel_pci.h

-/* 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
-

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;
 	}
 

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;