Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 3152 insertions, 0 deletions

diff --git a/drivers/thunderbolt/test.c b/drivers/thunderbolt/test.c
new file mode 100644
index 000000000..05652ee82
--- /dev/null
+++ b/drivers/thunderbolt/test.c
@@ -0,0 +1,3152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <kunit/test.h>
+#include <linux/idr.h>
+
+#include "tb.h"
+#include "tunnel.h"
+
+static int __ida_init(struct kunit_resource *res, void *context)
+{
+	struct ida *ida = context;
+
+	ida_init(ida);
+	res->data = ida;
+	return 0;
+}
+
+static void __ida_destroy(struct kunit_resource *res)
+{
+	struct ida *ida = res->data;
+
+	ida_destroy(ida);
+}
+
+static void kunit_ida_init(struct kunit *test, struct ida *ida)
+{
+	kunit_alloc_resource(test, __ida_init, __ida_destroy, GFP_KERNEL, ida);
+}
+
+static struct tb_switch *alloc_switch(struct kunit *test, u64 route,
+				      u8 upstream_port, u8 max_port_number)
+{
+	struct tb_switch *sw;
+	size_t size;
+	int i;
+
+	sw = kunit_kzalloc(test, sizeof(*sw), GFP_KERNEL);
+	if (!sw)
+		return NULL;
+
+	sw->config.upstream_port_number = upstream_port;
+	sw->config.depth = tb_route_length(route);
+	sw->config.route_hi = upper_32_bits(route);
+	sw->config.route_lo = lower_32_bits(route);
+	sw->config.enabled = 0;
+	sw->config.max_port_number = max_port_number;
+
+	size = (sw->config.max_port_number + 1) * sizeof(*sw->ports);
+	sw->ports = kunit_kzalloc(test, size, GFP_KERNEL);
+	if (!sw->ports)
+		return NULL;
+
+	for (i = 0; i <= sw->config.max_port_number; i++) {
+		sw->ports[i].sw = sw;
+		sw->ports[i].port = i;
+		sw->ports[i].config.port_number = i;
+		if (i) {
+			kunit_ida_init(test, &sw->ports[i].in_hopids);
+			kunit_ida_init(test, &sw->ports[i].out_hopids);
+		}
+	}
+
+	return sw;
+}
+
+static struct tb_switch *alloc_host(struct kunit *test)
+{
+	struct tb_switch *sw;
+
+	sw = alloc_switch(test, 0, 7, 13);
+	if (!sw)
+		return NULL;
+
+	sw->config.vendor_id = 0x8086;
+	sw->config.device_id = 0x9a1b;
+
+	sw->ports[0].config.type = TB_TYPE_PORT;
+	sw->ports[0].config.max_in_hop_id = 7;
+	sw->ports[0].config.max_out_hop_id = 7;
+
+	sw->ports[1].config.type = TB_TYPE_PORT;
+	sw->ports[1].config.max_in_hop_id = 19;
+	sw->ports[1].config.max_out_hop_id = 19;
+	sw->ports[1].total_credits = 60;
+	sw->ports[1].ctl_credits = 2;
+	sw->ports[1].dual_link_port = &sw->ports[2];
+
+	sw->ports[2].config.type = TB_TYPE_PORT;
+	sw->ports[2].config.max_in_hop_id = 19;
+	sw->ports[2].config.max_out_hop_id = 19;
+	sw->ports[2].total_credits = 60;
+	sw->ports[2].ctl_credits = 2;
+	sw->ports[2].dual_link_port = &sw->ports[1];
+	sw->ports[2].link_nr = 1;
+
+	sw->ports[3].config.type = TB_TYPE_PORT;
+	sw->ports[3].config.max_in_hop_id = 19;
+	sw->ports[3].config.max_out_hop_id = 19;
+	sw->ports[3].total_credits = 60;
+	sw->ports[3].ctl_credits = 2;
+	sw->ports[3].dual_link_port = &sw->ports[4];
+
+	sw->ports[4].config.type = TB_TYPE_PORT;
+	sw->ports[4].config.max_in_hop_id = 19;
+	sw->ports[4].config.max_out_hop_id = 19;
+	sw->ports[4].total_credits = 60;
+	sw->ports[4].ctl_credits = 2;
+	sw->ports[4].dual_link_port = &sw->ports[3];
+	sw->ports[4].link_nr = 1;
+
+	sw->ports[5].config.type = TB_TYPE_DP_HDMI_IN;
+	sw->ports[5].config.max_in_hop_id = 9;
+	sw->ports[5].config.max_out_hop_id = 9;
+	sw->ports[5].cap_adap = -1;
+
+	sw->ports[6].config.type = TB_TYPE_DP_HDMI_IN;
+	sw->ports[6].config.max_in_hop_id = 9;
+	sw->ports[6].config.max_out_hop_id = 9;
+	sw->ports[6].cap_adap = -1;
+
+	sw->ports[7].config.type = TB_TYPE_NHI;
+	sw->ports[7].config.max_in_hop_id = 11;
+	sw->ports[7].config.max_out_hop_id = 11;
+	sw->ports[7].config.nfc_credits = 0x41800000;
+
+	sw->ports[8].config.type = TB_TYPE_PCIE_DOWN;
+	sw->ports[8].config.max_in_hop_id = 8;
+	sw->ports[8].config.max_out_hop_id = 8;
+
+	sw->ports[9].config.type = TB_TYPE_PCIE_DOWN;
+	sw->ports[9].config.max_in_hop_id = 8;
+	sw->ports[9].config.max_out_hop_id = 8;
+
+	sw->ports[10].disabled = true;
+	sw->ports[11].disabled = true;
+
+	sw->ports[12].config.type = TB_TYPE_USB3_DOWN;
+	sw->ports[12].config.max_in_hop_id = 8;
+	sw->ports[12].config.max_out_hop_id = 8;
+
+	sw->ports[13].config.type = TB_TYPE_USB3_DOWN;
+	sw->ports[13].config.max_in_hop_id = 8;
+	sw->ports[13].config.max_out_hop_id = 8;
+
+	return sw;
+}
+
+static struct tb_switch *alloc_host_usb4(struct kunit *test)
+{
+	struct tb_switch *sw;
+
+	sw = alloc_host(test);
+	if (!sw)
+		return NULL;
+
+	sw->generation = 4;
+	sw->credit_allocation = true;
+	sw->max_usb3_credits = 32;
+	sw->min_dp_aux_credits = 1;
+	sw->min_dp_main_credits = 0;
+	sw->max_pcie_credits = 64;
+	sw->max_dma_credits = 14;
+
+	return sw;
+}
+
+static struct tb_switch *alloc_host_br(struct kunit *test)
+{
+	struct tb_switch *sw;
+
+	sw = alloc_host_usb4(test);
+	if (!sw)
+		return NULL;
+
+	sw->ports[10].config.type = TB_TYPE_DP_HDMI_IN;
+	sw->ports[10].config.max_in_hop_id = 9;
+	sw->ports[10].config.max_out_hop_id = 9;
+	sw->ports[10].cap_adap = -1;
+	sw->ports[10].disabled = false;
+
+	return sw;
+}
+
+static struct tb_switch *alloc_dev_default(struct kunit *test,
+					   struct tb_switch *parent,
+					   u64 route, bool bonded)
+{
+	struct tb_port *port, *upstream_port;
+	struct tb_switch *sw;
+
+	sw = alloc_switch(test, route, 1, 19);
+	if (!sw)
+		return NULL;
+
+	sw->config.vendor_id = 0x8086;
+	sw->config.device_id = 0x15ef;
+
+	sw->ports[0].config.type = TB_TYPE_PORT;
+	sw->ports[0].config.max_in_hop_id = 8;
+	sw->ports[0].config.max_out_hop_id = 8;
+
+	sw->ports[1].config.type = TB_TYPE_PORT;
+	sw->ports[1].config.max_in_hop_id = 19;
+	sw->ports[1].config.max_out_hop_id = 19;
+	sw->ports[1].total_credits = 60;
+	sw->ports[1].ctl_credits = 2;
+	sw->ports[1].dual_link_port = &sw->ports[2];
+
+	sw->ports[2].config.type = TB_TYPE_PORT;
+	sw->ports[2].config.max_in_hop_id = 19;
+	sw->ports[2].config.max_out_hop_id = 19;
+	sw->ports[2].total_credits = 60;
+	sw->ports[2].ctl_credits = 2;
+	sw->ports[2].dual_link_port = &sw->ports[1];
+	sw->ports[2].link_nr = 1;
+
+	sw->ports[3].config.type = TB_TYPE_PORT;
+	sw->ports[3].config.max_in_hop_id = 19;
+	sw->ports[3].config.max_out_hop_id = 19;
+	sw->ports[3].total_credits = 60;
+	sw->ports[3].ctl_credits = 2;
+	sw->ports[3].dual_link_port = &sw->ports[4];
+
+	sw->ports[4].config.type = TB_TYPE_PORT;
+	sw->ports[4].config.max_in_hop_id = 19;
+	sw->ports[4].config.max_out_hop_id = 19;
+	sw->ports[4].total_credits = 60;
+	sw->ports[4].ctl_credits = 2;
+	sw->ports[4].dual_link_port = &sw->ports[3];
+	sw->ports[4].link_nr = 1;
+
+	sw->ports[5].config.type = TB_TYPE_PORT;
+	sw->ports[5].config.max_in_hop_id = 19;
+	sw->ports[5].config.max_out_hop_id = 19;
+	sw->ports[5].total_credits = 60;
+	sw->ports[5].ctl_credits = 2;
+	sw->ports[5].dual_link_port = &sw->ports[6];
+
+	sw->ports[6].config.type = TB_TYPE_PORT;
+	sw->ports[6].config.max_in_hop_id = 19;
+	sw->ports[6].config.max_out_hop_id = 19;
+	sw->ports[6].total_credits = 60;
+	sw->ports[6].ctl_credits = 2;
+	sw->ports[6].dual_link_port = &sw->ports[5];
+	sw->ports[6].link_nr = 1;
+
+	sw->ports[7].config.type = TB_TYPE_PORT;
+	sw->ports[7].config.max_in_hop_id = 19;
+	sw->ports[7].config.max_out_hop_id = 19;
+	sw->ports[7].total_credits = 60;
+	sw->ports[7].ctl_credits = 2;
+	sw->ports[7].dual_link_port = &sw->ports[8];
+
+	sw->ports[8].config.type = TB_TYPE_PORT;
+	sw->ports[8].config.max_in_hop_id = 19;
+	sw->ports[8].config.max_out_hop_id = 19;
+	sw->ports[8].total_credits = 60;
+	sw->ports[8].ctl_credits = 2;
+	sw->ports[8].dual_link_port = &sw->ports[7];
+	sw->ports[8].link_nr = 1;
+
+	sw->ports[9].config.type = TB_TYPE_PCIE_UP;
+	sw->ports[9].config.max_in_hop_id = 8;
+	sw->ports[9].config.max_out_hop_id = 8;
+
+	sw->ports[10].config.type = TB_TYPE_PCIE_DOWN;
+	sw->ports[10].config.max_in_hop_id = 8;
+	sw->ports[10].config.max_out_hop_id = 8;
+
+	sw->ports[11].config.type = TB_TYPE_PCIE_DOWN;
+	sw->ports[11].config.max_in_hop_id = 8;
+	sw->ports[11].config.max_out_hop_id = 8;
+
+	sw->ports[12].config.type = TB_TYPE_PCIE_DOWN;
+	sw->ports[12].config.max_in_hop_id = 8;
+	sw->ports[12].config.max_out_hop_id = 8;
+
+	sw->ports[13].config.type = TB_TYPE_DP_HDMI_OUT;
+	sw->ports[13].config.max_in_hop_id = 9;
+	sw->ports[13].config.max_out_hop_id = 9;
+	sw->ports[13].cap_adap = -1;
+
+	sw->ports[14].config.type = TB_TYPE_DP_HDMI_OUT;
+	sw->ports[14].config.max_in_hop_id = 9;
+	sw->ports[14].config.max_out_hop_id = 9;
+	sw->ports[14].cap_adap = -1;
+
+	sw->ports[15].disabled = true;
+
+	sw->ports[16].config.type = TB_TYPE_USB3_UP;
+	sw->ports[16].config.max_in_hop_id = 8;
+	sw->ports[16].config.max_out_hop_id = 8;
+
+	sw->ports[17].config.type = TB_TYPE_USB3_DOWN;
+	sw->ports[17].config.max_in_hop_id = 8;
+	sw->ports[17].config.max_out_hop_id = 8;
+
+	sw->ports[18].config.type = TB_TYPE_USB3_DOWN;
+	sw->ports[18].config.max_in_hop_id = 8;
+	sw->ports[18].config.max_out_hop_id = 8;
+
+	sw->ports[19].config.type = TB_TYPE_USB3_DOWN;
+	sw->ports[19].config.max_in_hop_id = 8;
+	sw->ports[19].config.max_out_hop_id = 8;
+
+	if (!parent)
+		return sw;
+
+	/* Link them */
+	upstream_port = tb_upstream_port(sw);
+	port = tb_port_at(route, parent);
+	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;
+
+		if (bonded) {
+			/* Bonding is used */
+			port->bonded = true;
+			port->total_credits *= 2;
+			port->dual_link_port->bonded = true;
+			port->dual_link_port->total_credits = 0;
+			upstream_port->bonded = true;
+			upstream_port->total_credits *= 2;
+			upstream_port->dual_link_port->bonded = true;
+			upstream_port->dual_link_port->total_credits = 0;
+		}
+	}
+
+	return sw;
+}
+
+static struct tb_switch *alloc_dev_with_dpin(struct kunit *test,
+					     struct tb_switch *parent,
+					     u64 route, bool bonded)
+{
+	struct tb_switch *sw;
+
+	sw = alloc_dev_default(test, parent, route, bonded);
+	if (!sw)
+		return NULL;
+
+	sw->ports[13].config.type = TB_TYPE_DP_HDMI_IN;
+	sw->ports[13].config.max_in_hop_id = 9;
+	sw->ports[13].config.max_out_hop_id = 9;
+
+	sw->ports[14].config.type = TB_TYPE_DP_HDMI_IN;
+	sw->ports[14].config.max_in_hop_id = 9;
+	sw->ports[14].config.max_out_hop_id = 9;
+
+	return sw;
+}
+
+static struct tb_switch *alloc_dev_without_dp(struct kunit *test,
+					      struct tb_switch *parent,
+					      u64 route, bool bonded)
+{
+	struct tb_switch *sw;
+	int i;
+
+	sw = alloc_dev_default(test, parent, route, bonded);
+	if (!sw)
+		return NULL;
+	/*
+	 * Device with:
+	 * 2x USB4 Adapters (adapters 1,2 and 3,4),
+	 * 1x PCIe Upstream (adapter 9),
+	 * 1x PCIe Downstream (adapter 10),
+	 * 1x USB3 Upstream (adapter 16),
+	 * 1x USB3 Downstream (adapter 17)
+	 */
+	for (i = 5; i <= 8; i++)
+		sw->ports[i].disabled = true;
+
+	for (i = 11; i <= 14; i++)
+		sw->ports[i].disabled = true;
+
+	sw->ports[13].cap_adap = 0;
+	sw->ports[14].cap_adap = 0;
+
+	for (i = 18; i <= 19; i++)
+		sw->ports[i].disabled = true;
+
+	sw->generation = 4;
+	sw->credit_allocation = true;
+	sw->max_usb3_credits = 109;
+	sw->min_dp_aux_credits = 0;
+	sw->min_dp_main_credits = 0;
+	sw->max_pcie_credits = 30;
+	sw->max_dma_credits = 1;
+
+	return sw;
+}
+
+static struct tb_switch *alloc_dev_usb4(struct kunit *test,
+					struct tb_switch *parent,
+					u64 route, bool bonded)
+{
+	struct tb_switch *sw;
+
+	sw = alloc_dev_default(test, parent, route, bonded);
+	if (!sw)
+		return NULL;
+
+	sw->generation = 4;
+	sw->credit_allocation = true;
+	sw->max_usb3_credits = 14;
+	sw->min_dp_aux_credits = 1;
+	sw->min_dp_main_credits = 18;
+	sw->max_pcie_credits = 32;
+	sw->max_dma_credits = 14;
+
+	return sw;
+}
+
+static void tb_test_path_basic(struct kunit *test)
+{
+	struct tb_port *src_port, *dst_port, *p;
+	struct tb_switch *host;
+
+	host = alloc_host(test);
+
+	src_port = &host->ports[5];
+	dst_port = src_port;
+
+	p = tb_next_port_on_path(src_port, dst_port, NULL);
+	KUNIT_EXPECT_PTR_EQ(test, p, dst_port);
+
+	p = tb_next_port_on_path(src_port, dst_port, p);
+	KUNIT_EXPECT_TRUE(test, !p);
+}
+
+static void tb_test_path_not_connected_walk(struct kunit *test)
+{
+	struct tb_port *src_port, *dst_port, *p;
+	struct tb_switch *host, *dev;
+
+	host = alloc_host(test);
+	/* No connection between host and dev */
+	dev = alloc_dev_default(test, NULL, 3, true);
+
+	src_port = &host->ports[12];
+	dst_port = &dev->ports[16];
+
+	p = tb_next_port_on_path(src_port, dst_port, NULL);
+	KUNIT_EXPECT_PTR_EQ(test, p, src_port);
+
+	p = tb_next_port_on_path(src_port, dst_port, p);
+	KUNIT_EXPECT_PTR_EQ(test, p, &host->ports[3]);
+
+	p = tb_next_port_on_path(src_port, dst_port, p);
+	KUNIT_EXPECT_TRUE(test, !p);
+
+	/* Other direction */
+
+	p = tb_next_port_on_path(dst_port, src_port, NULL);
+	KUNIT_EXPECT_PTR_EQ(test, p, dst_port);
+
+	p = tb_next_port_on_path(dst_port, src_port, p);
+	KUNIT_EXPECT_PTR_EQ(test, p, &dev->ports[1]);
+
+	p = tb_next_port_on_path(dst_port, src_port, p);
+	KUNIT_EXPECT_TRUE(test, !p);
+}
+
+struct port_expectation {
+	u64 route;
+	u8 port;
+	enum tb_port_type type;
+};
+
+static void tb_test_path_single_hop_walk(struct kunit *test)
+{
+	/*
+	 * Walks from Host PCIe downstream port to Device #1 PCIe
+	 * upstream port.
+	 *
+	 *   [Host]
+	 *   1 |
+	 *   1 |
+	 *  [Device]
+	 */
+	static const struct port_expectation test_data[] = {
+		{ .route = 0x0, .port = 8, .type = TB_TYPE_PCIE_DOWN },
+		{ .route = 0x0, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 9, .type = TB_TYPE_PCIE_UP },
+	};
+	struct tb_port *src_port, *dst_port, *p;
+	struct tb_switch *host, *dev;
+	int i;
+
+	host = alloc_host(test);
+	dev = alloc_dev_default(test, host, 1, true);
+
+	src_port = &host->ports[8];
+	dst_port = &dev->ports[9];
+
+	/* Walk both directions */
+
+	i = 0;
+	tb_for_each_port_on_path(src_port, dst_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i++;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, ARRAY_SIZE(test_data));
+
+	i = ARRAY_SIZE(test_data) - 1;
+	tb_for_each_port_on_path(dst_port, src_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i--;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, -1);
+}
+
+static void tb_test_path_daisy_chain_walk(struct kunit *test)
+{
+	/*
+	 * Walks from Host DP IN to Device #2 DP OUT.
+	 *
+	 *           [Host]
+	 *            1 |
+	 *            1 |
+	 *         [Device #1]
+	 *       3 /
+	 *      1 /
+	 * [Device #2]
+	 */
+	static const struct port_expectation test_data[] = {
+		{ .route = 0x0, .port = 5, .type = TB_TYPE_DP_HDMI_IN },
+		{ .route = 0x0, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x301, .port = 13, .type = TB_TYPE_DP_HDMI_OUT },
+	};
+	struct tb_port *src_port, *dst_port, *p;
+	struct tb_switch *host, *dev1, *dev2;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x301, true);
+
+	src_port = &host->ports[5];
+	dst_port = &dev2->ports[13];
+
+	/* Walk both directions */
+
+	i = 0;
+	tb_for_each_port_on_path(src_port, dst_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i++;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, ARRAY_SIZE(test_data));
+
+	i = ARRAY_SIZE(test_data) - 1;
+	tb_for_each_port_on_path(dst_port, src_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i--;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, -1);
+}
+
+static void tb_test_path_simple_tree_walk(struct kunit *test)
+{
+	/*
+	 * Walks from Host DP IN to Device #3 DP OUT.
+	 *
+	 *           [Host]
+	 *            1 |
+	 *            1 |
+	 *         [Device #1]
+	 *       3 /   | 5  \ 7
+	 *      1 /    |     \ 1
+	 * [Device #2] |    [Device #4]
+	 *             | 1
+	 *         [Device #3]
+	 */
+	static const struct port_expectation test_data[] = {
+		{ .route = 0x0, .port = 5, .type = TB_TYPE_DP_HDMI_IN },
+		{ .route = 0x0, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 5, .type = TB_TYPE_PORT },
+		{ .route = 0x501, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x501, .port = 13, .type = TB_TYPE_DP_HDMI_OUT },
+	};
+	struct tb_port *src_port, *dst_port, *p;
+	struct tb_switch *host, *dev1, *dev3;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	alloc_dev_default(test, dev1, 0x301, true);
+	dev3 = alloc_dev_default(test, dev1, 0x501, true);
+	alloc_dev_default(test, dev1, 0x701, true);
+
+	src_port = &host->ports[5];
+	dst_port = &dev3->ports[13];
+
+	/* Walk both directions */
+
+	i = 0;
+	tb_for_each_port_on_path(src_port, dst_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i++;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, ARRAY_SIZE(test_data));
+
+	i = ARRAY_SIZE(test_data) - 1;
+	tb_for_each_port_on_path(dst_port, src_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i--;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, -1);
+}
+
+static void tb_test_path_complex_tree_walk(struct kunit *test)
+{
+	/*
+	 * Walks from Device #3 DP IN to Device #9 DP OUT.
+	 *
+	 *           [Host]
+	 *            1 |
+	 *            1 |
+	 *         [Device #1]
+	 *       3 /   | 5  \ 7
+	 *      1 /    |     \ 1
+	 * [Device #2] |    [Device #5]
+	 *    5 |      | 1         \ 7
+	 *    1 |  [Device #4]      \ 1
+	 * [Device #3]             [Device #6]
+	 *                       3 /
+	 *                      1 /
+	 *                    [Device #7]
+	 *                  3 /      | 5
+	 *                 1 /       |
+	 *               [Device #8] | 1
+	 *                       [Device #9]
+	 */
+	static const struct port_expectation test_data[] = {
+		{ .route = 0x50301, .port = 13, .type = TB_TYPE_DP_HDMI_IN },
+		{ .route = 0x50301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x301, .port = 5, .type = TB_TYPE_PORT },
+		{ .route = 0x301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 7, .type = TB_TYPE_PORT },
+		{ .route = 0x701, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x701, .port = 7, .type = TB_TYPE_PORT },
+		{ .route = 0x70701, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x70701, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x3070701, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x3070701, .port = 5, .type = TB_TYPE_PORT },
+		{ .route = 0x503070701, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x503070701, .port = 14, .type = TB_TYPE_DP_HDMI_OUT },
+	};
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev5, *dev6, *dev7, *dev9;
+	struct tb_port *src_port, *dst_port, *p;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x301, true);
+	dev3 = alloc_dev_with_dpin(test, dev2, 0x50301, true);
+	alloc_dev_default(test, dev1, 0x501, true);
+	dev5 = alloc_dev_default(test, dev1, 0x701, true);
+	dev6 = alloc_dev_default(test, dev5, 0x70701, true);
+	dev7 = alloc_dev_default(test, dev6, 0x3070701, true);
+	alloc_dev_default(test, dev7, 0x303070701, true);
+	dev9 = alloc_dev_default(test, dev7, 0x503070701, true);
+
+	src_port = &dev3->ports[13];
+	dst_port = &dev9->ports[14];
+
+	/* Walk both directions */
+
+	i = 0;
+	tb_for_each_port_on_path(src_port, dst_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i++;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, ARRAY_SIZE(test_data));
+
+	i = ARRAY_SIZE(test_data) - 1;
+	tb_for_each_port_on_path(dst_port, src_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i--;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, -1);
+}
+
+static void tb_test_path_max_length_walk(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev4, *dev5, *dev6;
+	struct tb_switch *dev7, *dev8, *dev9, *dev10, *dev11, *dev12;
+	struct tb_port *src_port, *dst_port, *p;
+	int i;
+
+	/*
+	 * Walks from Device #6 DP IN to Device #12 DP OUT.
+	 *
+	 *          [Host]
+	 *         1 /  \ 3
+	 *        1 /    \ 1
+	 * [Device #1]   [Device #7]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #2]   [Device #8]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #3]   [Device #9]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #4]   [Device #10]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #5]   [Device #11]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #6]   [Device #12]
+	 */
+	static const struct port_expectation test_data[] = {
+		{ .route = 0x30303030301, .port = 13, .type = TB_TYPE_DP_HDMI_IN },
+		{ .route = 0x30303030301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x303030301, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x303030301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x3030301, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x3030301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x30301, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x30301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x301, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x301, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x1, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x0, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x0, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x3, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x3, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x303, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x303, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x30303, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x30303, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x3030303, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x3030303, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x303030303, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x303030303, .port = 3, .type = TB_TYPE_PORT },
+		{ .route = 0x30303030303, .port = 1, .type = TB_TYPE_PORT },
+		{ .route = 0x30303030303, .port = 13, .type = TB_TYPE_DP_HDMI_OUT },
+	};
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x301, true);
+	dev3 = alloc_dev_default(test, dev2, 0x30301, true);
+	dev4 = alloc_dev_default(test, dev3, 0x3030301, true);
+	dev5 = alloc_dev_default(test, dev4, 0x303030301, true);
+	dev6 = alloc_dev_with_dpin(test, dev5, 0x30303030301, true);
+	dev7 = alloc_dev_default(test, host, 0x3, true);
+	dev8 = alloc_dev_default(test, dev7, 0x303, true);
+	dev9 = alloc_dev_default(test, dev8, 0x30303, true);
+	dev10 = alloc_dev_default(test, dev9, 0x3030303, true);
+	dev11 = alloc_dev_default(test, dev10, 0x303030303, true);
+	dev12 = alloc_dev_default(test, dev11, 0x30303030303, true);
+
+	src_port = &dev6->ports[13];
+	dst_port = &dev12->ports[13];
+
+	/* Walk both directions */
+
+	i = 0;
+	tb_for_each_port_on_path(src_port, dst_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i++;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, ARRAY_SIZE(test_data));
+
+	i = ARRAY_SIZE(test_data) - 1;
+	tb_for_each_port_on_path(dst_port, src_port, p) {
+		KUNIT_EXPECT_TRUE(test, i < ARRAY_SIZE(test_data));
+		KUNIT_EXPECT_EQ(test, tb_route(p->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, p->port, test_data[i].port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)p->config.type,
+				test_data[i].type);
+		i--;
+	}
+
+	KUNIT_EXPECT_EQ(test, i, -1);
+}
+
+static void tb_test_path_not_connected(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2;
+	struct tb_port *down, *up;
+	struct tb_path *path;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x3, false);
+	/* Not connected to anything */
+	dev2 = alloc_dev_default(test, NULL, 0x303, false);
+
+	down = &dev1->ports[10];
+	up = &dev2->ports[9];
+
+	path = tb_path_alloc(NULL, down, 8, up, 8, 0, "PCIe Down");
+	KUNIT_ASSERT_NULL(test, path);
+	path = tb_path_alloc(NULL, down, 8, up, 8, 1, "PCIe Down");
+	KUNIT_ASSERT_NULL(test, path);
+}
+
+struct hop_expectation {
+	u64 route;
+	u8 in_port;
+	enum tb_port_type in_type;
+	u8 out_port;
+	enum tb_port_type out_type;
+};
+
+static void tb_test_path_not_bonded_lane0(struct kunit *test)
+{
+	/*
+	 * PCIe path from host to device using lane 0.
+	 *
+	 *   [Host]
+	 *   3 |: 4
+	 *   1 |: 2
+	 *  [Device]
+	 */
+	static const struct hop_expectation test_data[] = {
+		{
+			.route = 0x0,
+			.in_port = 9,
+			.in_type = TB_TYPE_PCIE_DOWN,
+			.out_port = 3,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x3,
+			.in_port = 1,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 9,
+			.out_type = TB_TYPE_PCIE_UP,
+		},
+	};
+	struct tb_switch *host, *dev;
+	struct tb_port *down, *up;
+	struct tb_path *path;
+	int i;
+
+	host = alloc_host(test);
+	dev = alloc_dev_default(test, host, 0x3, false);
+
+	down = &host->ports[9];
+	up = &dev->ports[9];
+
+	path = tb_path_alloc(NULL, down, 8, up, 8, 0, "PCIe Down");
+	KUNIT_ASSERT_NOT_NULL(test, path);
+	KUNIT_ASSERT_EQ(test, path->path_length, ARRAY_SIZE(test_data));
+	for (i = 0; i < ARRAY_SIZE(test_data); i++) {
+		const struct tb_port *in_port, *out_port;
+
+		in_port = path->hops[i].in_port;
+		out_port = path->hops[i].out_port;
+
+		KUNIT_EXPECT_EQ(test, tb_route(in_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, in_port->port, test_data[i].in_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)in_port->config.type,
+				test_data[i].in_type);
+		KUNIT_EXPECT_EQ(test, tb_route(out_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, out_port->port, test_data[i].out_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)out_port->config.type,
+				test_data[i].out_type);
+	}
+	tb_path_free(path);
+}
+
+static void tb_test_path_not_bonded_lane1(struct kunit *test)
+{
+	/*
+	 * DP Video path from host to device using lane 1. Paths like
+	 * these are only used with Thunderbolt 1 devices where lane
+	 * bonding is not possible. USB4 specifically does not allow
+	 * paths like this (you either use lane 0 where lane 1 is
+	 * disabled or both lanes are bonded).
+	 *
+	 *   [Host]
+	 *   1 :| 2
+	 *   1 :| 2
+	 *  [Device]
+	 */
+	static const struct hop_expectation test_data[] = {
+		{
+			.route = 0x0,
+			.in_port = 5,
+			.in_type = TB_TYPE_DP_HDMI_IN,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x1,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 13,
+			.out_type = TB_TYPE_DP_HDMI_OUT,
+		},
+	};
+	struct tb_switch *host, *dev;
+	struct tb_port *in, *out;
+	struct tb_path *path;
+	int i;
+
+	host = alloc_host(test);
+	dev = alloc_dev_default(test, host, 0x1, false);
+
+	in = &host->ports[5];
+	out = &dev->ports[13];
+
+	path = tb_path_alloc(NULL, in, 9, out, 9, 1, "Video");
+	KUNIT_ASSERT_NOT_NULL(test, path);
+	KUNIT_ASSERT_EQ(test, path->path_length, ARRAY_SIZE(test_data));
+	for (i = 0; i < ARRAY_SIZE(test_data); i++) {
+		const struct tb_port *in_port, *out_port;
+
+		in_port = path->hops[i].in_port;
+		out_port = path->hops[i].out_port;
+
+		KUNIT_EXPECT_EQ(test, tb_route(in_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, in_port->port, test_data[i].in_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)in_port->config.type,
+				test_data[i].in_type);
+		KUNIT_EXPECT_EQ(test, tb_route(out_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, out_port->port, test_data[i].out_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)out_port->config.type,
+				test_data[i].out_type);
+	}
+	tb_path_free(path);
+}
+
+static void tb_test_path_not_bonded_lane1_chain(struct kunit *test)
+{
+	/*
+	 * DP Video path from host to device 3 using lane 1.
+	 *
+	 *    [Host]
+	 *    1 :| 2
+	 *    1 :| 2
+	 *  [Device #1]
+	 *    7 :| 8
+	 *    1 :| 2
+	 *  [Device #2]
+	 *    5 :| 6
+	 *    1 :| 2
+	 *  [Device #3]
+	 */
+	static const struct hop_expectation test_data[] = {
+		{
+			.route = 0x0,
+			.in_port = 5,
+			.in_type = TB_TYPE_DP_HDMI_IN,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x1,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 8,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x701,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 6,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x50701,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 13,
+			.out_type = TB_TYPE_DP_HDMI_OUT,
+		},
+	};
+	struct tb_switch *host, *dev1, *dev2, *dev3;
+	struct tb_port *in, *out;
+	struct tb_path *path;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, false);
+	dev2 = alloc_dev_default(test, dev1, 0x701, false);
+	dev3 = alloc_dev_default(test, dev2, 0x50701, false);
+
+	in = &host->ports[5];
+	out = &dev3->ports[13];
+
+	path = tb_path_alloc(NULL, in, 9, out, 9, 1, "Video");
+	KUNIT_ASSERT_NOT_NULL(test, path);
+	KUNIT_ASSERT_EQ(test, path->path_length, ARRAY_SIZE(test_data));
+	for (i = 0; i < ARRAY_SIZE(test_data); i++) {
+		const struct tb_port *in_port, *out_port;
+
+		in_port = path->hops[i].in_port;
+		out_port = path->hops[i].out_port;
+
+		KUNIT_EXPECT_EQ(test, tb_route(in_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, in_port->port, test_data[i].in_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)in_port->config.type,
+				test_data[i].in_type);
+		KUNIT_EXPECT_EQ(test, tb_route(out_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, out_port->port, test_data[i].out_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)out_port->config.type,
+				test_data[i].out_type);
+	}
+	tb_path_free(path);
+}
+
+static void tb_test_path_not_bonded_lane1_chain_reverse(struct kunit *test)
+{
+	/*
+	 * DP Video path from device 3 to host using lane 1.
+	 *
+	 *    [Host]
+	 *    1 :| 2
+	 *    1 :| 2
+	 *  [Device #1]
+	 *    7 :| 8
+	 *    1 :| 2
+	 *  [Device #2]
+	 *    5 :| 6
+	 *    1 :| 2
+	 *  [Device #3]
+	 */
+	static const struct hop_expectation test_data[] = {
+		{
+			.route = 0x50701,
+			.in_port = 13,
+			.in_type = TB_TYPE_DP_HDMI_IN,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x701,
+			.in_port = 6,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x1,
+			.in_port = 8,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x0,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 5,
+			.out_type = TB_TYPE_DP_HDMI_IN,
+		},
+	};
+	struct tb_switch *host, *dev1, *dev2, *dev3;
+	struct tb_port *in, *out;
+	struct tb_path *path;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, false);
+	dev2 = alloc_dev_default(test, dev1, 0x701, false);
+	dev3 = alloc_dev_with_dpin(test, dev2, 0x50701, false);
+
+	in = &dev3->ports[13];
+	out = &host->ports[5];
+
+	path = tb_path_alloc(NULL, in, 9, out, 9, 1, "Video");
+	KUNIT_ASSERT_NOT_NULL(test, path);
+	KUNIT_ASSERT_EQ(test, path->path_length, ARRAY_SIZE(test_data));
+	for (i = 0; i < ARRAY_SIZE(test_data); i++) {
+		const struct tb_port *in_port, *out_port;
+
+		in_port = path->hops[i].in_port;
+		out_port = path->hops[i].out_port;
+
+		KUNIT_EXPECT_EQ(test, tb_route(in_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, in_port->port, test_data[i].in_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)in_port->config.type,
+				test_data[i].in_type);
+		KUNIT_EXPECT_EQ(test, tb_route(out_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, out_port->port, test_data[i].out_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)out_port->config.type,
+				test_data[i].out_type);
+	}
+	tb_path_free(path);
+}
+
+static void tb_test_path_mixed_chain(struct kunit *test)
+{
+	/*
+	 * DP Video path from host to device 4 where first and last link
+	 * is bonded.
+	 *
+	 *    [Host]
+	 *    1 |
+	 *    1 |
+	 *  [Device #1]
+	 *    7 :| 8
+	 *    1 :| 2
+	 *  [Device #2]
+	 *    5 :| 6
+	 *    1 :| 2
+	 *  [Device #3]
+	 *    3 |
+	 *    1 |
+	 *  [Device #4]
+	 */
+	static const struct hop_expectation test_data[] = {
+		{
+			.route = 0x0,
+			.in_port = 5,
+			.in_type = TB_TYPE_DP_HDMI_IN,
+			.out_port = 1,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x1,
+			.in_port = 1,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 8,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x701,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 6,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x50701,
+			.in_port = 2,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 3,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x3050701,
+			.in_port = 1,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 13,
+			.out_type = TB_TYPE_DP_HDMI_OUT,
+		},
+	};
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev4;
+	struct tb_port *in, *out;
+	struct tb_path *path;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x701, false);
+	dev3 = alloc_dev_default(test, dev2, 0x50701, false);
+	dev4 = alloc_dev_default(test, dev3, 0x3050701, true);
+
+	in = &host->ports[5];
+	out = &dev4->ports[13];
+
+	path = tb_path_alloc(NULL, in, 9, out, 9, 1, "Video");
+	KUNIT_ASSERT_NOT_NULL(test, path);
+	KUNIT_ASSERT_EQ(test, path->path_length, ARRAY_SIZE(test_data));
+	for (i = 0; i < ARRAY_SIZE(test_data); i++) {
+		const struct tb_port *in_port, *out_port;
+
+		in_port = path->hops[i].in_port;
+		out_port = path->hops[i].out_port;
+
+		KUNIT_EXPECT_EQ(test, tb_route(in_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, in_port->port, test_data[i].in_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)in_port->config.type,
+				test_data[i].in_type);
+		KUNIT_EXPECT_EQ(test, tb_route(out_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, out_port->port, test_data[i].out_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)out_port->config.type,
+				test_data[i].out_type);
+	}
+	tb_path_free(path);
+}
+
+static void tb_test_path_mixed_chain_reverse(struct kunit *test)
+{
+	/*
+	 * DP Video path from device 4 to host where first and last link
+	 * is bonded.
+	 *
+	 *    [Host]
+	 *    1 |
+	 *    1 |
+	 *  [Device #1]
+	 *    7 :| 8
+	 *    1 :| 2
+	 *  [Device #2]
+	 *    5 :| 6
+	 *    1 :| 2
+	 *  [Device #3]
+	 *    3 |
+	 *    1 |
+	 *  [Device #4]
+	 */
+	static const struct hop_expectation test_data[] = {
+		{
+			.route = 0x3050701,
+			.in_port = 13,
+			.in_type = TB_TYPE_DP_HDMI_OUT,
+			.out_port = 1,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x50701,
+			.in_port = 3,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x701,
+			.in_port = 6,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 2,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x1,
+			.in_port = 8,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 1,
+			.out_type = TB_TYPE_PORT,
+		},
+		{
+			.route = 0x0,
+			.in_port = 1,
+			.in_type = TB_TYPE_PORT,
+			.out_port = 5,
+			.out_type = TB_TYPE_DP_HDMI_IN,
+		},
+	};
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev4;
+	struct tb_port *in, *out;
+	struct tb_path *path;
+	int i;
+
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x701, false);
+	dev3 = alloc_dev_default(test, dev2, 0x50701, false);
+	dev4 = alloc_dev_default(test, dev3, 0x3050701, true);
+
+	in = &dev4->ports[13];
+	out = &host->ports[5];
+
+	path = tb_path_alloc(NULL, in, 9, out, 9, 1, "Video");
+	KUNIT_ASSERT_NOT_NULL(test, path);
+	KUNIT_ASSERT_EQ(test, path->path_length, ARRAY_SIZE(test_data));
+	for (i = 0; i < ARRAY_SIZE(test_data); i++) {
+		const struct tb_port *in_port, *out_port;
+
+		in_port = path->hops[i].in_port;
+		out_port = path->hops[i].out_port;
+
+		KUNIT_EXPECT_EQ(test, tb_route(in_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, in_port->port, test_data[i].in_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)in_port->config.type,
+				test_data[i].in_type);
+		KUNIT_EXPECT_EQ(test, tb_route(out_port->sw), test_data[i].route);
+		KUNIT_EXPECT_EQ(test, out_port->port, test_data[i].out_port);
+		KUNIT_EXPECT_EQ(test, (enum tb_port_type)out_port->config.type,
+				test_data[i].out_type);
+	}
+	tb_path_free(path);
+}
+
+static void tb_test_tunnel_pcie(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2;
+	struct tb_tunnel *tunnel1, *tunnel2;
+	struct tb_port *down, *up;
+
+	/*
+	 * Create PCIe tunnel between host and two devices.
+	 *
+	 *   [Host]
+	 *    1 |
+	 *    1 |
+	 *  [Device #1]
+	 *    5 |
+	 *    1 |
+	 *  [Device #2]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x501, true);
+
+	down = &host->ports[8];
+	up = &dev1->ports[9];
+	tunnel1 = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel1);
+	KUNIT_EXPECT_EQ(test, tunnel1->type, TB_TUNNEL_PCI);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->src_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->dst_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel1->npaths, 2);
+	KUNIT_ASSERT_EQ(test, tunnel1->paths[0]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[0]->hops[0].in_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[0]->hops[1].out_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel1->paths[1]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[1]->hops[0].in_port, up);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[1]->hops[1].out_port, down);
+
+	down = &dev1->ports[10];
+	up = &dev2->ports[9];
+	tunnel2 = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel2);
+	KUNIT_EXPECT_EQ(test, tunnel2->type, TB_TUNNEL_PCI);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->src_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->dst_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel2->npaths, 2);
+	KUNIT_ASSERT_EQ(test, tunnel2->paths[0]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[0]->hops[0].in_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[0]->hops[1].out_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel2->paths[1]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[1]->hops[0].in_port, up);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[1]->hops[1].out_port, down);
+
+	tb_tunnel_put(tunnel2);
+	tb_tunnel_put(tunnel1);
+}
+
+static void tb_test_tunnel_dp(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Create DP tunnel between Host and Device
+	 *
+	 *   [Host]
+	 *   1 |
+	 *   1 |
+	 *  [Device]
+	 */
+	host = alloc_host(test);
+	dev = alloc_dev_default(test, host, 0x3, true);
+
+	in = &host->ports[5];
+	out = &dev->ports[13];
+
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[1].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[1]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[1].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[2]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[0].in_port, out);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[1].out_port, in);
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dp_chain(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev4;
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Create DP tunnel from Host DP IN to Device #4 DP OUT.
+	 *
+	 *           [Host]
+	 *            1 |
+	 *            1 |
+	 *         [Device #1]
+	 *       3 /   | 5  \ 7
+	 *      1 /    |     \ 1
+	 * [Device #2] |    [Device #4]
+	 *             | 1
+	 *         [Device #3]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	alloc_dev_default(test, dev1, 0x301, true);
+	alloc_dev_default(test, dev1, 0x501, true);
+	dev4 = alloc_dev_default(test, dev1, 0x701, true);
+
+	in = &host->ports[5];
+	out = &dev4->ports[14];
+
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[2].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[1]->path_length, 3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[2].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[2]->path_length, 3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[0].in_port, out);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[2].out_port, in);
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dp_tree(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev5;
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Create DP tunnel from Device #2 DP IN to Device #5 DP OUT.
+	 *
+	 *          [Host]
+	 *           3 |
+	 *           1 |
+	 *         [Device #1]
+	 *       3 /   | 5  \ 7
+	 *      1 /    |     \ 1
+	 * [Device #2] |    [Device #4]
+	 *             | 1
+	 *         [Device #3]
+	 *             | 5
+	 *             | 1
+	 *         [Device #5]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x3, true);
+	dev2 = alloc_dev_with_dpin(test, dev1, 0x303, true);
+	dev3 = alloc_dev_default(test, dev1, 0x503, true);
+	alloc_dev_default(test, dev1, 0x703, true);
+	dev5 = alloc_dev_default(test, dev3, 0x50503, true);
+
+	in = &dev2->ports[13];
+	out = &dev5->ports[13];
+
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 4);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[3].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[1]->path_length, 4);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[3].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[2]->path_length, 4);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[0].in_port, out);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[3].out_port, in);
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dp_max_length(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev4, *dev5, *dev6;
+	struct tb_switch *dev7, *dev8, *dev9, *dev10, *dev11, *dev12;
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Creates DP tunnel from Device #6 to Device #12.
+	 *
+	 *          [Host]
+	 *         1 /  \ 3
+	 *        1 /    \ 1
+	 * [Device #1]   [Device #7]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #2]   [Device #8]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #3]   [Device #9]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #4]   [Device #10]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #5]   [Device #11]
+	 *     3 |           | 3
+	 *     1 |           | 1
+	 * [Device #6]   [Device #12]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x301, true);
+	dev3 = alloc_dev_default(test, dev2, 0x30301, true);
+	dev4 = alloc_dev_default(test, dev3, 0x3030301, true);
+	dev5 = alloc_dev_default(test, dev4, 0x303030301, true);
+	dev6 = alloc_dev_with_dpin(test, dev5, 0x30303030301, true);
+	dev7 = alloc_dev_default(test, host, 0x3, true);
+	dev8 = alloc_dev_default(test, dev7, 0x303, true);
+	dev9 = alloc_dev_default(test, dev8, 0x30303, true);
+	dev10 = alloc_dev_default(test, dev9, 0x3030303, true);
+	dev11 = alloc_dev_default(test, dev10, 0x303030303, true);
+	dev12 = alloc_dev_default(test, dev11, 0x30303030303, true);
+
+	in = &dev6->ports[13];
+	out = &dev12->ports[13];
+
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 13);
+	/* First hop */
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, in);
+	/* Middle */
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[6].in_port,
+			    &host->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[6].out_port,
+			    &host->ports[3]);
+	/* Last */
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[12].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[1]->path_length, 13);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].in_port, in);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[6].in_port,
+			    &host->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[6].out_port,
+			    &host->ports[3]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[12].out_port, out);
+	KUNIT_ASSERT_EQ(test, tunnel->paths[2]->path_length, 13);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[0].in_port, out);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[6].in_port,
+			    &host->ports[3]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[6].out_port,
+			    &host->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[2]->hops[12].out_port, in);
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_3dp(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev4, *dev5;
+	struct tb_port *in1, *in2, *in3, *out1, *out2, *out3;
+	struct tb_tunnel *tunnel1, *tunnel2, *tunnel3;
+
+	/*
+	 * Create 3 DP tunnels from Host to Devices #2, #5 and #4.
+	 *
+	 *          [Host]
+	 *           3 |
+	 *           1 |
+	 *         [Device #1]
+	 *       3 /   | 5  \ 7
+	 *      1 /    |     \ 1
+	 * [Device #2] |    [Device #4]
+	 *             | 1
+	 *         [Device #3]
+	 *             | 5
+	 *             | 1
+	 *         [Device #5]
+	 */
+	host = alloc_host_br(test);
+	dev1 = alloc_dev_default(test, host, 0x3, true);
+	dev2 = alloc_dev_default(test, dev1, 0x303, true);
+	dev3 = alloc_dev_default(test, dev1, 0x503, true);
+	dev4 = alloc_dev_default(test, dev1, 0x703, true);
+	dev5 = alloc_dev_default(test, dev3, 0x50503, true);
+
+	in1 = &host->ports[5];
+	in2 = &host->ports[6];
+	in3 = &host->ports[10];
+
+	out1 = &dev2->ports[13];
+	out2 = &dev5->ports[13];
+	out3 = &dev4->ports[14];
+
+	tunnel1 = tb_tunnel_alloc_dp(NULL, in1, out1, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_TRUE(test, tunnel1 != NULL);
+	KUNIT_EXPECT_EQ(test, tunnel1->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->src_port, in1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->dst_port, out1);
+	KUNIT_ASSERT_EQ(test, tunnel1->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel1->paths[0]->path_length, 3);
+
+	tunnel2 = tb_tunnel_alloc_dp(NULL, in2, out2, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_TRUE(test, tunnel2 != NULL);
+	KUNIT_EXPECT_EQ(test, tunnel2->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->src_port, in2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->dst_port, out2);
+	KUNIT_ASSERT_EQ(test, tunnel2->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel2->paths[0]->path_length, 4);
+
+	tunnel3 = tb_tunnel_alloc_dp(NULL, in3, out3, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_TRUE(test, tunnel3 != NULL);
+	KUNIT_EXPECT_EQ(test, tunnel3->type, TB_TUNNEL_DP);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel3->src_port, in3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel3->dst_port, out3);
+	KUNIT_ASSERT_EQ(test, tunnel3->npaths, 3);
+	KUNIT_ASSERT_EQ(test, tunnel3->paths[0]->path_length, 3);
+
+	tb_tunnel_put(tunnel3);
+	tb_tunnel_put(tunnel2);
+	tb_tunnel_put(tunnel1);
+}
+
+static void tb_test_tunnel_usb3(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2;
+	struct tb_tunnel *tunnel1, *tunnel2;
+	struct tb_port *down, *up;
+
+	/*
+	 * Create USB3 tunnel between host and two devices.
+	 *
+	 *   [Host]
+	 *    1 |
+	 *    1 |
+	 *  [Device #1]
+	 *          \ 7
+	 *           \ 1
+	 *         [Device #2]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x701, true);
+
+	down = &host->ports[12];
+	up = &dev1->ports[16];
+	tunnel1 = tb_tunnel_alloc_usb3(NULL, up, down, 0, 0);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel1);
+	KUNIT_EXPECT_EQ(test, tunnel1->type, TB_TUNNEL_USB3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->src_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->dst_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel1->npaths, 2);
+	KUNIT_ASSERT_EQ(test, tunnel1->paths[0]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[0]->hops[0].in_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[0]->hops[1].out_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel1->paths[1]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[1]->hops[0].in_port, up);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel1->paths[1]->hops[1].out_port, down);
+
+	down = &dev1->ports[17];
+	up = &dev2->ports[16];
+	tunnel2 = tb_tunnel_alloc_usb3(NULL, up, down, 0, 0);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel2);
+	KUNIT_EXPECT_EQ(test, tunnel2->type, TB_TUNNEL_USB3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->src_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->dst_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel2->npaths, 2);
+	KUNIT_ASSERT_EQ(test, tunnel2->paths[0]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[0]->hops[0].in_port, down);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[0]->hops[1].out_port, up);
+	KUNIT_ASSERT_EQ(test, tunnel2->paths[1]->path_length, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[1]->hops[0].in_port, up);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel2->paths[1]->hops[1].out_port, down);
+
+	tb_tunnel_put(tunnel2);
+	tb_tunnel_put(tunnel1);
+}
+
+static void tb_test_tunnel_port_on_path(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2, *dev3, *dev4, *dev5;
+	struct tb_port *in, *out, *port;
+	struct tb_tunnel *dp_tunnel;
+
+	/*
+	 *          [Host]
+	 *           3 |
+	 *           1 |
+	 *         [Device #1]
+	 *       3 /   | 5  \ 7
+	 *      1 /    |     \ 1
+	 * [Device #2] |    [Device #4]
+	 *             | 1
+	 *         [Device #3]
+	 *             | 5
+	 *             | 1
+	 *         [Device #5]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x3, true);
+	dev2 = alloc_dev_with_dpin(test, dev1, 0x303, true);
+	dev3 = alloc_dev_default(test, dev1, 0x503, true);
+	dev4 = alloc_dev_default(test, dev1, 0x703, true);
+	dev5 = alloc_dev_default(test, dev3, 0x50503, true);
+
+	in = &dev2->ports[13];
+	out = &dev5->ports[13];
+
+	dp_tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, dp_tunnel);
+
+	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, in));
+	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, out));
+
+	port = &host->ports[8];
+	KUNIT_EXPECT_FALSE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &host->ports[3];
+	KUNIT_EXPECT_FALSE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev1->ports[1];
+	KUNIT_EXPECT_FALSE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev1->ports[3];
+	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev1->ports[5];
+	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev1->ports[7];
+	KUNIT_EXPECT_FALSE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev3->ports[1];
+	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev5->ports[1];
+	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	port = &dev4->ports[1];
+	KUNIT_EXPECT_FALSE(test, tb_tunnel_port_on_path(dp_tunnel, port));
+
+	tb_tunnel_put(dp_tunnel);
+}
+
+static void tb_test_tunnel_dma(struct kunit *test)
+{
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *tunnel;
+	struct tb_switch *host;
+
+	/*
+	 * Create DMA tunnel from NHI to port 1 and back.
+	 *
+	 *   [Host 1]
+	 *    1 ^ In HopID 1 -> Out HopID 8
+	 *      |
+	 *      v In HopID 8 -> Out HopID 1
+	 * ............ Domain border
+	 *      |
+	 *   [Host 2]
+	 */
+	host = alloc_host(test);
+	nhi = &host->ports[7];
+	port = &host->ports[1];
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, 8, 1, 8, 1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DMA);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, nhi);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, port);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 2);
+	/* RX path */
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, port);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].in_hop_index, 8);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].out_port, nhi);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].next_hop_index, 1);
+	/* TX path */
+	KUNIT_ASSERT_EQ(test, tunnel->paths[1]->path_length, 1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].in_port, nhi);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[1]->hops[0].in_hop_index, 1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].out_port, port);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[1]->hops[0].next_hop_index, 8);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dma_rx(struct kunit *test)
+{
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *tunnel;
+	struct tb_switch *host;
+
+	/*
+	 * Create DMA RX tunnel from port 1 to NHI.
+	 *
+	 *   [Host 1]
+	 *    1 ^
+	 *      |
+	 *      | In HopID 15 -> Out HopID 2
+	 * ............ Domain border
+	 *      |
+	 *   [Host 2]
+	 */
+	host = alloc_host(test);
+	nhi = &host->ports[7];
+	port = &host->ports[1];
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, -1, -1, 15, 2);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DMA);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, nhi);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, port);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 1);
+	/* RX path */
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, port);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].in_hop_index, 15);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].out_port, nhi);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].next_hop_index, 2);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dma_tx(struct kunit *test)
+{
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *tunnel;
+	struct tb_switch *host;
+
+	/*
+	 * Create DMA TX tunnel from NHI to port 1.
+	 *
+	 *   [Host 1]
+	 *    1 | In HopID 2 -> Out HopID 15
+	 *      |
+	 *      v
+	 * ............ Domain border
+	 *      |
+	 *   [Host 2]
+	 */
+	host = alloc_host(test);
+	nhi = &host->ports[7];
+	port = &host->ports[1];
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, 15, 2, -1, -1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DMA);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, nhi);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, port);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 1);
+	/* TX path */
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, nhi);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].in_hop_index, 2);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].out_port, port);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].next_hop_index, 15);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dma_chain(struct kunit *test)
+{
+	struct tb_switch *host, *dev1, *dev2;
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Create DMA tunnel from NHI to Device #2 port 3 and back.
+	 *
+	 *   [Host 1]
+	 *    1 ^ In HopID 1 -> Out HopID x
+	 *      |
+	 *    1 | In HopID x -> Out HopID 1
+	 *  [Device #1]
+	 *         7 \
+	 *          1 \
+	 *         [Device #2]
+	 *           3 | In HopID x -> Out HopID 8
+	 *             |
+	 *             v In HopID 8 -> Out HopID x
+	 * ............ Domain border
+	 *             |
+	 *          [Host 2]
+	 */
+	host = alloc_host(test);
+	dev1 = alloc_dev_default(test, host, 0x1, true);
+	dev2 = alloc_dev_default(test, dev1, 0x701, true);
+
+	nhi = &host->ports[7];
+	port = &dev2->ports[3];
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, 8, 1, 8, 1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DMA);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, nhi);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->dst_port, port);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, 2);
+	/* RX path */
+	KUNIT_ASSERT_EQ(test, tunnel->paths[0]->path_length, 3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].in_port, port);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[0].in_hop_index, 8);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[0].out_port,
+			    &dev2->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[1].in_port,
+			    &dev1->ports[7]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[1].out_port,
+			    &dev1->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[2].in_port,
+			    &host->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[0]->hops[2].out_port, nhi);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[0]->hops[2].next_hop_index, 1);
+	/* TX path */
+	KUNIT_ASSERT_EQ(test, tunnel->paths[1]->path_length, 3);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[0].in_port, nhi);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[1]->hops[0].in_hop_index, 1);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[1].in_port,
+			    &dev1->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[1].out_port,
+			    &dev1->ports[7]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[2].in_port,
+			    &dev2->ports[1]);
+	KUNIT_EXPECT_PTR_EQ(test, tunnel->paths[1]->hops[2].out_port, port);
+	KUNIT_EXPECT_EQ(test, tunnel->paths[1]->hops[2].next_hop_index, 8);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_tunnel_dma_match(struct kunit *test)
+{
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *tunnel;
+	struct tb_switch *host;
+
+	host = alloc_host(test);
+	nhi = &host->ports[7];
+	port = &host->ports[1];
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, 15, 1, 15, 1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, 15, 1, 15, 1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, 8, 1, 15, 1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, 15, 1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, 15, 1, -1, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, 15, -1, -1, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, 1, -1, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, 15, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, -1, 1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, -1, -1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, 8, -1, 8, -1));
+
+	tb_tunnel_put(tunnel);
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, 15, 1, -1, -1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, 15, 1, -1, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, 15, -1, -1, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, 1, -1, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, -1, -1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, 15, 1, 15, 1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, -1, -1, 15, 1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, 15, 11, -1, -1));
+
+	tb_tunnel_put(tunnel);
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, -1, -1, 15, 11);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, 15, 11));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, 15, -1));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, -1, 11));
+	KUNIT_ASSERT_TRUE(test, tb_tunnel_match_dma(tunnel, -1, -1, -1, -1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, -1, -1, 15, 1));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, -1, -1, 10, 11));
+	KUNIT_ASSERT_FALSE(test, tb_tunnel_match_dma(tunnel, 15, 11, -1, -1));
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_legacy_not_bonded(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *up, *down;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host(test);
+	dev = alloc_dev_default(test, host, 0x1, false);
+
+	down = &host->ports[8];
+	up = &dev->ports[9];
+	tunnel = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 16U);
+
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 16U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_legacy_bonded(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *up, *down;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host(test);
+	dev = alloc_dev_default(test, host, 0x1, true);
+
+	down = &host->ports[8];
+	up = &dev->ports[9];
+	tunnel = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 32U);
+
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 32U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_pcie(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *up, *down;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_usb4(test, host, 0x1, true);
+
+	down = &host->ports[8];
+	up = &dev->ports[9];
+	tunnel = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 32U);
+
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 64U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_without_dp(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *up, *down;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_without_dp(test, host, 0x1, true);
+
+	/*
+	 * The device has no DP therefore baMinDPmain = baMinDPaux = 0
+	 *
+	 * Create PCIe path with buffers less than baMaxPCIe.
+	 *
+	 * For a device with buffers configurations:
+	 * baMaxUSB3 = 109
+	 * baMinDPaux = 0
+	 * baMinDPmain = 0
+	 * baMaxPCIe = 30
+	 * baMaxHI = 1
+	 * Remaining Buffers = Total - (CP + DP) = 120 - (2 + 0) = 118
+	 * PCIe Credits = Max(6, Min(baMaxPCIe, Remaining Buffers - baMaxUSB3)
+	 *		= Max(6, Min(30, 9) = 9
+	 */
+	down = &host->ports[8];
+	up = &dev->ports[9];
+	tunnel = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	/* PCIe downstream path */
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 9U);
+
+	/* PCIe upstream path */
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 64U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_dp(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_usb4(test, host, 0x1, true);
+
+	in = &host->ports[5];
+	out = &dev->ports[14];
+
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)3);
+
+	/* Video (main) path */
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 12U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 18U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 0U);
+
+	/* AUX TX */
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 1U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	/* AUX RX */
+	path = tunnel->paths[2];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 1U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_usb3(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *up, *down;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_usb4(test, host, 0x1, true);
+
+	down = &host->ports[12];
+	up = &dev->ports[16];
+	tunnel = tb_tunnel_alloc_usb3(NULL, up, down, 0, 0);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 32U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_dma(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_usb4(test, host, 0x1, true);
+
+	nhi = &host->ports[7];
+	port = &dev->ports[3];
+
+	tunnel = tb_tunnel_alloc_dma(NULL, nhi, port, 8, 1, 8, 1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	/* DMA RX */
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 14U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	/* DMA TX */
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	tb_tunnel_put(tunnel);
+}
+
+static void tb_test_credit_alloc_dma_multiple(struct kunit *test)
+{
+	struct tb_tunnel *tunnel1, *tunnel2, *tunnel3;
+	struct tb_switch *host, *dev;
+	struct tb_port *nhi, *port;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_usb4(test, host, 0x1, true);
+
+	nhi = &host->ports[7];
+	port = &dev->ports[3];
+
+	/*
+	 * Create three DMA tunnels through the same ports. With the
+	 * default buffers we should be able to create two and the last
+	 * one fails.
+	 *
+	 * For default host we have following buffers for DMA:
+	 *
+	 *   120 - (2 + 2 * (1 + 0) + 32 + 64 + spare) = 20
+	 *
+	 * For device we have following:
+	 *
+	 *  120 - (2 + 2 * (1 + 18) + 14 + 32 + spare) = 34
+	 *
+	 * spare = 14 + 1 = 15
+	 *
+	 * So on host the first tunnel gets 14 and the second gets the
+	 * remaining 1 and then we run out of buffers.
+	 */
+	tunnel1 = tb_tunnel_alloc_dma(NULL, nhi, port, 8, 1, 8, 1);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel1);
+	KUNIT_ASSERT_EQ(test, tunnel1->npaths, (size_t)2);
+
+	path = tunnel1->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 14U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	path = tunnel1->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	tunnel2 = tb_tunnel_alloc_dma(NULL, nhi, port, 9, 2, 9, 2);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel2);
+	KUNIT_ASSERT_EQ(test, tunnel2->npaths, (size_t)2);
+
+	path = tunnel2->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 14U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	path = tunnel2->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	tunnel3 = tb_tunnel_alloc_dma(NULL, nhi, port, 10, 3, 10, 3);
+	KUNIT_ASSERT_NULL(test, tunnel3);
+
+	/*
+	 * Release the first DMA tunnel. That should make 14 buffers
+	 * available for the next tunnel.
+	 */
+	tb_tunnel_put(tunnel1);
+
+	tunnel3 = tb_tunnel_alloc_dma(NULL, nhi, port, 10, 3, 10, 3);
+	KUNIT_ASSERT_NOT_NULL(test, tunnel3);
+
+	path = tunnel3->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 14U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	path = tunnel3->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	tb_tunnel_put(tunnel3);
+	tb_tunnel_put(tunnel2);
+}
+
+static struct tb_tunnel *TB_TEST_PCIE_TUNNEL(struct kunit *test,
+			struct tb_switch *host, struct tb_switch *dev)
+{
+	struct tb_port *up, *down;
+	struct tb_tunnel *pcie_tunnel;
+	struct tb_path *path;
+
+	down = &host->ports[8];
+	up = &dev->ports[9];
+	pcie_tunnel = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_NOT_NULL(test, pcie_tunnel);
+	KUNIT_ASSERT_EQ(test, pcie_tunnel->npaths, (size_t)2);
+
+	path = pcie_tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 32U);
+
+	path = pcie_tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 64U);
+
+	return pcie_tunnel;
+}
+
+static struct tb_tunnel *TB_TEST_DP_TUNNEL1(struct kunit *test,
+			struct tb_switch *host, struct tb_switch *dev)
+{
+	struct tb_port *in, *out;
+	struct tb_tunnel *dp_tunnel1;
+	struct tb_path *path;
+
+	in = &host->ports[5];
+	out = &dev->ports[13];
+	dp_tunnel1 = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, dp_tunnel1);
+	KUNIT_ASSERT_EQ(test, dp_tunnel1->npaths, (size_t)3);
+
+	path = dp_tunnel1->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 12U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 18U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 0U);
+
+	path = dp_tunnel1->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 1U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	path = dp_tunnel1->paths[2];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 1U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	return dp_tunnel1;
+}
+
+static struct tb_tunnel *TB_TEST_DP_TUNNEL2(struct kunit *test,
+			struct tb_switch *host, struct tb_switch *dev)
+{
+	struct tb_port *in, *out;
+	struct tb_tunnel *dp_tunnel2;
+	struct tb_path *path;
+
+	in = &host->ports[6];
+	out = &dev->ports[14];
+	dp_tunnel2 = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0, NULL, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, dp_tunnel2);
+	KUNIT_ASSERT_EQ(test, dp_tunnel2->npaths, (size_t)3);
+
+	path = dp_tunnel2->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 12U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 18U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 0U);
+
+	path = dp_tunnel2->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 1U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	path = dp_tunnel2->paths[2];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 1U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	return dp_tunnel2;
+}
+
+static struct tb_tunnel *TB_TEST_USB3_TUNNEL(struct kunit *test,
+			struct tb_switch *host, struct tb_switch *dev)
+{
+	struct tb_port *up, *down;
+	struct tb_tunnel *usb3_tunnel;
+	struct tb_path *path;
+
+	down = &host->ports[12];
+	up = &dev->ports[16];
+	usb3_tunnel = tb_tunnel_alloc_usb3(NULL, up, down, 0, 0);
+	KUNIT_ASSERT_NOT_NULL(test, usb3_tunnel);
+	KUNIT_ASSERT_EQ(test, usb3_tunnel->npaths, (size_t)2);
+
+	path = usb3_tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	path = usb3_tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 32U);
+
+	return usb3_tunnel;
+}
+
+static struct tb_tunnel *TB_TEST_DMA_TUNNEL1(struct kunit *test,
+			struct tb_switch *host, struct tb_switch *dev)
+{
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *dma_tunnel1;
+	struct tb_path *path;
+
+	nhi = &host->ports[7];
+	port = &dev->ports[3];
+	dma_tunnel1 = tb_tunnel_alloc_dma(NULL, nhi, port, 8, 1, 8, 1);
+	KUNIT_ASSERT_NOT_NULL(test, dma_tunnel1);
+	KUNIT_ASSERT_EQ(test, dma_tunnel1->npaths, (size_t)2);
+
+	path = dma_tunnel1->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 14U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	path = dma_tunnel1->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 14U);
+
+	return dma_tunnel1;
+}
+
+static struct tb_tunnel *TB_TEST_DMA_TUNNEL2(struct kunit *test,
+			struct tb_switch *host, struct tb_switch *dev)
+{
+	struct tb_port *nhi, *port;
+	struct tb_tunnel *dma_tunnel2;
+	struct tb_path *path;
+
+	nhi = &host->ports[7];
+	port = &dev->ports[3];
+	dma_tunnel2 = tb_tunnel_alloc_dma(NULL, nhi, port, 9, 2, 9, 2);
+	KUNIT_ASSERT_NOT_NULL(test, dma_tunnel2);
+	KUNIT_ASSERT_EQ(test, dma_tunnel2->npaths, (size_t)2);
+
+	path = dma_tunnel2->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 14U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	path = dma_tunnel2->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 1U);
+
+	return dma_tunnel2;
+}
+
+static void tb_test_credit_alloc_all(struct kunit *test)
+{
+	struct tb_tunnel *pcie_tunnel, *dp_tunnel1, *dp_tunnel2, *usb3_tunnel;
+	struct tb_tunnel *dma_tunnel1, *dma_tunnel2;
+	struct tb_switch *host, *dev;
+
+	/*
+	 * Create PCIe, 2 x DP, USB 3.x and two DMA tunnels from host to
+	 * device. Expectation is that all these can be established with
+	 * the default credit allocation found in Intel hardware.
+	 */
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_usb4(test, host, 0x1, true);
+
+	pcie_tunnel = TB_TEST_PCIE_TUNNEL(test, host, dev);
+	dp_tunnel1 = TB_TEST_DP_TUNNEL1(test, host, dev);
+	dp_tunnel2 = TB_TEST_DP_TUNNEL2(test, host, dev);
+	usb3_tunnel = TB_TEST_USB3_TUNNEL(test, host, dev);
+	dma_tunnel1 = TB_TEST_DMA_TUNNEL1(test, host, dev);
+	dma_tunnel2 = TB_TEST_DMA_TUNNEL2(test, host, dev);
+
+	tb_tunnel_put(dma_tunnel2);
+	tb_tunnel_put(dma_tunnel1);
+	tb_tunnel_put(usb3_tunnel);
+	tb_tunnel_put(dp_tunnel2);
+	tb_tunnel_put(dp_tunnel1);
+	tb_tunnel_put(pcie_tunnel);
+}
+
+static const u32 root_directory[] = {
+	0x55584401,	/* "UXD" v1 */
+	0x00000018,	/* Root directory length */
+	0x76656e64,	/* "vend" */
+	0x6f726964,	/* "orid" */
+	0x76000001,	/* "v" R 1 */
+	0x00000a27,	/* Immediate value, ! Vendor ID */
+	0x76656e64,	/* "vend" */
+	0x6f726964,	/* "orid" */
+	0x74000003,	/* "t" R 3 */
+	0x0000001a,	/* Text leaf offset, (“Apple Inc.”) */
+	0x64657669,	/* "devi" */
+	0x63656964,	/* "ceid" */
+	0x76000001,	/* "v" R 1 */
+	0x0000000a,	/* Immediate value, ! Device ID */
+	0x64657669,	/* "devi" */
+	0x63656964,	/* "ceid" */
+	0x74000003,	/* "t" R 3 */
+	0x0000001d,	/* Text leaf offset, (“Macintosh”) */
+	0x64657669,	/* "devi" */
+	0x63657276,	/* "cerv" */
+	0x76000001,	/* "v" R 1 */
+	0x80000100,	/* Immediate value, Device Revision */
+	0x6e657477,	/* "netw" */
+	0x6f726b00,	/* "ork" */
+	0x44000014,	/* "D" R 20 */
+	0x00000021,	/* Directory data offset, (Network Directory) */
+	0x4170706c,	/* "Appl" */
+	0x6520496e,	/* "e In" */
+	0x632e0000,	/* "c." ! */
+	0x4d616369,	/* "Maci" */
+	0x6e746f73,	/* "ntos" */
+	0x68000000,	/* "h" */
+	0x00000000,	/* padding */
+	0xca8961c6,	/* Directory UUID, Network Directory */
+	0x9541ce1c,	/* Directory UUID, Network Directory */
+	0x5949b8bd,	/* Directory UUID, Network Directory */
+	0x4f5a5f2e,	/* Directory UUID, Network Directory */
+	0x70727463,	/* "prtc" */
+	0x69640000,	/* "id" */
+	0x76000001,	/* "v" R 1 */
+	0x00000001,	/* Immediate value, Network Protocol ID */
+	0x70727463,	/* "prtc" */
+	0x76657273,	/* "vers" */
+	0x76000001,	/* "v" R 1 */
+	0x00000001,	/* Immediate value, Network Protocol Version */
+	0x70727463,	/* "prtc" */
+	0x72657673,	/* "revs" */
+	0x76000001,	/* "v" R 1 */
+	0x00000001,	/* Immediate value, Network Protocol Revision */
+	0x70727463,	/* "prtc" */
+	0x73746e73,	/* "stns" */
+	0x76000001,	/* "v" R 1 */
+	0x00000000,	/* Immediate value, Network Protocol Settings */
+};
+
+static const uuid_t network_dir_uuid =
+	UUID_INIT(0xc66189ca, 0x1cce, 0x4195,
+		  0xbd, 0xb8, 0x49, 0x59, 0x2e, 0x5f, 0x5a, 0x4f);
+
+static void tb_test_property_parse(struct kunit *test)
+{
+	struct tb_property_dir *dir, *network_dir;
+	struct tb_property *p;
+
+	dir = tb_property_parse_dir(root_directory, ARRAY_SIZE(root_directory));
+	KUNIT_ASSERT_NOT_NULL(test, dir);
+
+	p = tb_property_find(dir, "foo", TB_PROPERTY_TYPE_TEXT);
+	KUNIT_ASSERT_NULL(test, p);
+
+	p = tb_property_find(dir, "vendorid", TB_PROPERTY_TYPE_TEXT);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_STREQ(test, p->value.text, "Apple Inc.");
+
+	p = tb_property_find(dir, "vendorid", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_EQ(test, p->value.immediate, 0xa27);
+
+	p = tb_property_find(dir, "deviceid", TB_PROPERTY_TYPE_TEXT);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_STREQ(test, p->value.text, "Macintosh");
+
+	p = tb_property_find(dir, "deviceid", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_EQ(test, p->value.immediate, 0xa);
+
+	p = tb_property_find(dir, "missing", TB_PROPERTY_TYPE_DIRECTORY);
+	KUNIT_ASSERT_NULL(test, p);
+
+	p = tb_property_find(dir, "network", TB_PROPERTY_TYPE_DIRECTORY);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+
+	network_dir = p->value.dir;
+	KUNIT_EXPECT_TRUE(test, uuid_equal(network_dir->uuid, &network_dir_uuid));
+
+	p = tb_property_find(network_dir, "prtcid", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_EQ(test, p->value.immediate, 0x1);
+
+	p = tb_property_find(network_dir, "prtcvers", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_EQ(test, p->value.immediate, 0x1);
+
+	p = tb_property_find(network_dir, "prtcrevs", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_EQ(test, p->value.immediate, 0x1);
+
+	p = tb_property_find(network_dir, "prtcstns", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_EXPECT_EQ(test, p->value.immediate, 0x0);
+
+	p = tb_property_find(network_dir, "deviceid", TB_PROPERTY_TYPE_VALUE);
+	KUNIT_EXPECT_TRUE(test, !p);
+	p = tb_property_find(network_dir, "deviceid", TB_PROPERTY_TYPE_TEXT);
+	KUNIT_EXPECT_TRUE(test, !p);
+
+	tb_property_free_dir(dir);
+}
+
+static void tb_test_property_format(struct kunit *test)
+{
+	struct tb_property_dir *dir;
+	ssize_t block_len;
+	u32 *block;
+	int ret, i;
+
+	dir = tb_property_parse_dir(root_directory, ARRAY_SIZE(root_directory));
+	KUNIT_ASSERT_NOT_NULL(test, dir);
+
+	ret = tb_property_format_dir(dir, NULL, 0);
+	KUNIT_ASSERT_EQ(test, ret, ARRAY_SIZE(root_directory));
+
+	block_len = ret;
+
+	block = kunit_kzalloc(test, block_len * sizeof(u32), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	ret = tb_property_format_dir(dir, block, block_len);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	for (i = 0; i < ARRAY_SIZE(root_directory); i++)
+		KUNIT_EXPECT_EQ(test, root_directory[i], block[i]);
+
+	tb_property_free_dir(dir);
+}
+
+static void compare_dirs(struct kunit *test, struct tb_property_dir *d1,
+			 struct tb_property_dir *d2)
+{
+	struct tb_property *p1, *p2, *tmp;
+	int n1, n2, i;
+
+	if (d1->uuid) {
+		KUNIT_ASSERT_NOT_NULL(test, d2->uuid);
+		KUNIT_ASSERT_TRUE(test, uuid_equal(d1->uuid, d2->uuid));
+	} else {
+		KUNIT_ASSERT_NULL(test, d2->uuid);
+	}
+
+	n1 = 0;
+	tb_property_for_each(d1, tmp)
+		n1++;
+	KUNIT_ASSERT_NE(test, n1, 0);
+
+	n2 = 0;
+	tb_property_for_each(d2, tmp)
+		n2++;
+	KUNIT_ASSERT_NE(test, n2, 0);
+
+	KUNIT_ASSERT_EQ(test, n1, n2);
+
+	p1 = NULL;
+	p2 = NULL;
+	for (i = 0; i < n1; i++) {
+		p1 = tb_property_get_next(d1, p1);
+		KUNIT_ASSERT_NOT_NULL(test, p1);
+		p2 = tb_property_get_next(d2, p2);
+		KUNIT_ASSERT_NOT_NULL(test, p2);
+
+		KUNIT_ASSERT_STREQ(test, &p1->key[0], &p2->key[0]);
+		KUNIT_ASSERT_EQ(test, p1->type, p2->type);
+		KUNIT_ASSERT_EQ(test, p1->length, p2->length);
+
+		switch (p1->type) {
+		case TB_PROPERTY_TYPE_DIRECTORY:
+			KUNIT_ASSERT_NOT_NULL(test, p1->value.dir);
+			KUNIT_ASSERT_NOT_NULL(test, p2->value.dir);
+			compare_dirs(test, p1->value.dir, p2->value.dir);
+			break;
+
+		case TB_PROPERTY_TYPE_DATA:
+			KUNIT_ASSERT_NOT_NULL(test, p1->value.data);
+			KUNIT_ASSERT_NOT_NULL(test, p2->value.data);
+			KUNIT_ASSERT_TRUE(test,
+				!memcmp(p1->value.data, p2->value.data,
+					p1->length * 4)
+			);
+			break;
+
+		case TB_PROPERTY_TYPE_TEXT:
+			KUNIT_ASSERT_NOT_NULL(test, p1->value.text);
+			KUNIT_ASSERT_NOT_NULL(test, p2->value.text);
+			KUNIT_ASSERT_STREQ(test, p1->value.text, p2->value.text);
+			break;
+
+		case TB_PROPERTY_TYPE_VALUE:
+			KUNIT_ASSERT_EQ(test, p1->value.immediate,
+					p2->value.immediate);
+			break;
+		default:
+			KUNIT_FAIL(test, "unexpected property type");
+			break;
+		}
+	}
+}
+
+static void tb_test_property_copy(struct kunit *test)
+{
+	struct tb_property_dir *src, *dst;
+	u32 *block;
+	int ret, i;
+
+	src = tb_property_parse_dir(root_directory, ARRAY_SIZE(root_directory));
+	KUNIT_ASSERT_NOT_NULL(test, src);
+
+	dst = tb_property_copy_dir(src);
+	KUNIT_ASSERT_NOT_NULL(test, dst);
+
+	/* Compare the structures */
+	compare_dirs(test, src, dst);
+
+	/* Compare the resulting property block */
+	ret = tb_property_format_dir(dst, NULL, 0);
+	KUNIT_ASSERT_EQ(test, ret, ARRAY_SIZE(root_directory));
+
+	block = kunit_kzalloc(test, sizeof(root_directory), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	ret = tb_property_format_dir(dst, block, ARRAY_SIZE(root_directory));
+	KUNIT_EXPECT_TRUE(test, !ret);
+
+	for (i = 0; i < ARRAY_SIZE(root_directory); i++)
+		KUNIT_EXPECT_EQ(test, root_directory[i], block[i]);
+
+	tb_property_free_dir(dst);
+	tb_property_free_dir(src);
+}
+
+/*
+ * Reproducers for three memory-safety defects in
+ * drivers/thunderbolt/property.c reached from a crafted XDomain
+ * PROPERTIES_RESPONSE payload.  Without the fix these trip KASAN or
+ * smash the kernel stack; with the fix each returns NULL cleanly.
+ *
+ * The on-wire entry layout matches struct tb_property_entry in
+ * property.c (private to that translation unit): u32 key_hi, u32
+ * key_lo, then a packed u32 = (type << 24) | (reserved << 16) |
+ * length, then u32 value.  Each entry is 4 dwords.
+ */
+
+static void tb_test_property_parse_u32_wrap(struct kunit *test)
+{
+	/*
+	 * 0x102 dwords: enough for the entry's length field (0x100) to
+	 * pass the "entry->length > block_len" gate so the wrap check
+	 * is actually exercised.  parse_dwdata's downstream OOB read
+	 * lands ~16 GiB past the allocation regardless.
+	 */
+	u32 *block = kunit_kzalloc(test, 0x102 * sizeof(u32), GFP_KERNEL);
+	struct tb_property_dir *dir;
+
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	block[0] = 0x55584401;	/* "UXD" v1 magic */
+	block[1] = 0x00000004;	/* Root directory length: one entry */
+
+	/*
+	 * DATA entry whose value 0xffffff00 + length 0x100 wrap to 0
+	 * in u32, passing the sum <= block_len guard even though the
+	 * real offset is far past the allocation.
+	 */
+	block[2] = 0x61616161;	/* key_hi */
+	block[3] = 0x61616161;	/* key_lo */
+	block[4] = 0x64000100;	/* type=DATA, reserved=0, length=0x100 */
+	block[5] = 0xffffff00;	/* value */
+
+	dir = tb_property_parse_dir(block, 0x102);
+	KUNIT_EXPECT_NULL(test, dir);
+	tb_property_free_dir(dir);
+}
+
+static void tb_test_property_parse_recursion(struct kunit *test)
+{
+	/*
+	 * 10 dwords: rootdir header (2) + parent DIRECTORY entry (4) +
+	 * the child entry that lives at dir_offset(2) + UUID(4) = 6,
+	 * occupying block[6..9].  Each recursive level re-reads the
+	 * same block[6..9] as its first child entry, which is itself
+	 * a DIRECTORY pointing at offset 2.
+	 */
+	u32 *block = kunit_kzalloc(test, 10 * sizeof(u32), GFP_KERNEL);
+	struct tb_property_dir *dir;
+
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	block[0] = 0x55584401;	/* "UXD" v1 magic */
+	block[1] = 0x00000004;	/* Root directory length: one entry */
+
+	/*
+	 * DIRECTORY entry pointing at dir_offset = 2 with length = 8.
+	 * Non-root parse derives content_offset = 6, content_len = 4,
+	 * nentries = 1.  block[6..9] is read both as the parent's UUID
+	 * (kmemdup'd into dir->uuid) and as the single child entry --
+	 * which is itself a DIRECTORY pointing at offset 2, so the
+	 * recursion never terminates and the kernel stack is exhausted.
+	 */
+	block[2] = 0x61616161;	/* key_hi */
+	block[3] = 0x61616161;	/* key_lo */
+	block[4] = 0x44000008;	/* type=DIRECTORY, reserved=0, length=8 */
+	block[5] = 0x00000002;	/* value = dir_offset */
+
+	block[6] = 0x62626262;	/* doubles as UUID dword 0 / child key_hi */
+	block[7] = 0x62626262;	/* doubles as UUID dword 1 / child key_lo */
+	block[8] = 0x44000008;	/* type=DIRECTORY, reserved=0, length=8 */
+	block[9] = 0x00000002;	/* value = dir_offset (back at parent) */
+
+	dir = tb_property_parse_dir(block, 10);
+	KUNIT_EXPECT_NULL(test, dir);
+	tb_property_free_dir(dir);
+}
+
+static void tb_test_property_parse_dir_len_underflow(struct kunit *test)
+{
+	/*
+	 * Allocate exactly 7 dwords (28 bytes) so the kmalloc-32 chunk
+	 * leaves a 4-byte slab redzone tail that KASAN-Generic can flag.
+	 * With block_len = 7, dir_offset = 4, dir_len = 3, the non-root
+	 * UUID kmemdup reads 16 bytes from byte 16, so bytes 28..31 fall
+	 * in the redzone and trip a KASAN slab-out-of-bounds report on
+	 * the pre-fix kernel.  Sizing the buffer at a power of two (32,
+	 * 64, ...) puts the over-read into the slab cache tail where
+	 * KASAN's generic shadow does not flag it, and the test reduces
+	 * to the downstream content_len = dir_len - 4 underflow path
+	 * which also returns NULL.
+	 */
+	u32 *block = kunit_kzalloc(test, 7 * sizeof(u32), GFP_KERNEL);
+	struct tb_property_dir *dir;
+
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	block[0] = 0x55584401;	/* "UXD" v1 magic */
+	block[1] = 0x00000004;	/* Root directory length: one entry */
+
+	/*
+	 * DIRECTORY entry with length = 3 pointing at dir_offset = 4.
+	 * tb_property_entry_valid() permits value(4) + length(3) <=
+	 * block_len(7).  Non-root parse begins with a kmemdup of 4
+	 * dwords from dir_offset for the UUID; that read runs past the
+	 * 28-byte allocation before the dir_len < 4 reject would fire.
+	 */
+	block[2] = 0x61616161;	/* key_hi */
+	block[3] = 0x61616161;	/* key_lo */
+	block[4] = 0x44000003;	/* type=DIRECTORY, reserved=0, length=3 */
+	block[5] = 0x00000004;	/* value = dir_offset */
+	/* block[6] is the start of the four UUID dwords; block[7..] is OOB. */
+
+	dir = tb_property_parse_dir(block, 7);
+	KUNIT_EXPECT_NULL(test, dir);
+	tb_property_free_dir(dir);
+}
+
+static void tb_test_property_parse_zero_length(struct kunit *test)
+{
+	u32 *block = kunit_kzalloc(test, 6 * sizeof(u32), GFP_KERNEL);
+	struct tb_property_dir *dir;
+
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	block[0] = 0x55584401;	/* rootdir magic */
+	block[1] = 0x00000004;	/* root length: one entry */
+
+	block[2] = 0x61616161;	/* key_hi */
+	block[3] = 0x61616161;	/* key_lo */
+	block[4] = 0x74000000;	/* type=TEXT, reserved=0, length=0 */
+	block[5] = 0x00000000;	/* value */
+
+	dir = tb_property_parse_dir(block, 6);
+	KUNIT_EXPECT_NULL(test, dir);
+	tb_property_free_dir(dir);
+}
+
+static void tb_test_property_parse_rootdir_overflow(struct kunit *test)
+{
+	u32 *block = kunit_kzalloc(test, 4 * sizeof(u32), GFP_KERNEL);
+	struct tb_property_dir *dir;
+
+	KUNIT_ASSERT_NOT_NULL(test, block);
+
+	block[0] = 0x55584401;	/* rootdir magic */
+	block[1] = 0x00000004;	/* root length claims 4 dwords of content */
+	block[2] = 0x61616161;
+	block[3] = 0x61616161;
+
+	/* content_offset(2) + content_len(4) = 6 > block_len(4) */
+	dir = tb_property_parse_dir(block, 4);
+	KUNIT_EXPECT_NULL(test, dir);
+	tb_property_free_dir(dir);
+}
+
+static void tb_test_property_merge(struct kunit *test)
+{
+	struct tb_property_dir *dir1, *dir2, *dir3;
+	struct tb_property *p;
+	uuid_t uuid;
+	int ret;
+
+	dir1 = tb_property_create_dir(&network_dir_uuid);
+	KUNIT_ASSERT_NOT_NULL(test, dir1);
+	ret = tb_property_add_immediate(dir1, "prtcid", 1);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	ret = tb_property_add_immediate(dir1, "prtcvers", 1);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	ret = tb_property_add_immediate(dir1, "prtcrevs", 0);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	ret = tb_property_add_immediate(dir1, "prtcstns", 0);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	dir2 = tb_property_create_dir(&network_dir_uuid);
+	KUNIT_ASSERT_NOT_NULL(test, dir2);
+	ret = tb_property_add_text(dir2, "descr", "This is text");
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	/* This replaces the value in dir1 */
+	ret = tb_property_add_immediate(dir2, "prtcvers", 0x1234);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	uuid_gen(&uuid);
+	dir3 = tb_property_create_dir(&uuid);
+	KUNIT_ASSERT_NOT_NULL(test, dir3);
+	ret = tb_property_add_immediate(dir3, "value0", 0);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	ret = tb_property_add_text(dir3, "value1", "Text value");
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	ret = tb_property_add_dir(dir2, "my", dir3);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	ret = tb_property_merge_dir(dir1, dir2, true);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	p = tb_property_get_next(dir1, NULL);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_ASSERT_STREQ(test, &p->key[0], "prtcid");
+	KUNIT_ASSERT_EQ(test, p->type, TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_EQ(test, p->length, 1);
+	KUNIT_ASSERT_EQ(test, p->value.immediate, 1);
+	p = tb_property_get_next(dir1, p);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_ASSERT_STREQ(test, &p->key[0], "prtcvers");
+	KUNIT_ASSERT_EQ(test, p->type, TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_EQ(test, p->length, 1);
+	KUNIT_ASSERT_EQ(test, p->value.immediate, 0x1234);
+	p = tb_property_get_next(dir1, p);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_ASSERT_STREQ(test, &p->key[0], "prtcrevs");
+	KUNIT_ASSERT_EQ(test, p->type, TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_EQ(test, p->length, 1);
+	KUNIT_ASSERT_EQ(test, p->value.immediate, 0);
+	p = tb_property_get_next(dir1, p);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_ASSERT_STREQ(test, &p->key[0], "prtcstns");
+	KUNIT_ASSERT_EQ(test, p->type, TB_PROPERTY_TYPE_VALUE);
+	KUNIT_ASSERT_EQ(test, p->length, 1);
+	KUNIT_ASSERT_EQ(test, p->value.immediate, 0);
+	p = tb_property_get_next(dir1, p);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_ASSERT_STREQ(test, &p->key[0], "descr");
+	KUNIT_ASSERT_EQ(test, p->type, TB_PROPERTY_TYPE_TEXT);
+	KUNIT_ASSERT_EQ(test, p->length, 4);
+	KUNIT_ASSERT_STREQ(test, p->value.text, "This is text");
+	p = tb_property_get_next(dir1, p);
+	KUNIT_ASSERT_NOT_NULL(test, p);
+	KUNIT_ASSERT_STREQ(test, &p->key[0], "my");
+	KUNIT_ASSERT_EQ(test, p->type, TB_PROPERTY_TYPE_DIRECTORY);
+	compare_dirs(test, p->value.dir, dir3);
+	p = tb_property_get_next(dir1, p);
+	KUNIT_ASSERT_NULL(test, p);
+
+	tb_property_free_dir(dir2);
+	tb_property_free_dir(dir1);
+}
+
+static struct kunit_case tb_test_cases[] = {
+	KUNIT_CASE(tb_test_property_parse_u32_wrap),
+	KUNIT_CASE(tb_test_property_parse_recursion),
+	KUNIT_CASE(tb_test_property_parse_dir_len_underflow),
+	KUNIT_CASE(tb_test_path_basic),
+	KUNIT_CASE(tb_test_path_not_connected_walk),
+	KUNIT_CASE(tb_test_path_single_hop_walk),
+	KUNIT_CASE(tb_test_path_daisy_chain_walk),
+	KUNIT_CASE(tb_test_path_simple_tree_walk),
+	KUNIT_CASE(tb_test_path_complex_tree_walk),
+	KUNIT_CASE(tb_test_path_max_length_walk),
+	KUNIT_CASE(tb_test_path_not_connected),
+	KUNIT_CASE(tb_test_path_not_bonded_lane0),
+	KUNIT_CASE(tb_test_path_not_bonded_lane1),
+	KUNIT_CASE(tb_test_path_not_bonded_lane1_chain),
+	KUNIT_CASE(tb_test_path_not_bonded_lane1_chain_reverse),
+	KUNIT_CASE(tb_test_path_mixed_chain),
+	KUNIT_CASE(tb_test_path_mixed_chain_reverse),
+	KUNIT_CASE(tb_test_tunnel_pcie),
+	KUNIT_CASE(tb_test_tunnel_dp),
+	KUNIT_CASE(tb_test_tunnel_dp_chain),
+	KUNIT_CASE(tb_test_tunnel_dp_tree),
+	KUNIT_CASE(tb_test_tunnel_dp_max_length),
+	KUNIT_CASE(tb_test_tunnel_3dp),
+	KUNIT_CASE(tb_test_tunnel_port_on_path),
+	KUNIT_CASE(tb_test_tunnel_usb3),
+	KUNIT_CASE(tb_test_tunnel_dma),
+	KUNIT_CASE(tb_test_tunnel_dma_rx),
+	KUNIT_CASE(tb_test_tunnel_dma_tx),
+	KUNIT_CASE(tb_test_tunnel_dma_chain),
+	KUNIT_CASE(tb_test_tunnel_dma_match),
+	KUNIT_CASE(tb_test_credit_alloc_legacy_not_bonded),
+	KUNIT_CASE(tb_test_credit_alloc_legacy_bonded),
+	KUNIT_CASE(tb_test_credit_alloc_pcie),
+	KUNIT_CASE(tb_test_credit_alloc_without_dp),
+	KUNIT_CASE(tb_test_credit_alloc_dp),
+	KUNIT_CASE(tb_test_credit_alloc_usb3),
+	KUNIT_CASE(tb_test_credit_alloc_dma),
+	KUNIT_CASE(tb_test_credit_alloc_dma_multiple),
+	KUNIT_CASE(tb_test_credit_alloc_all),
+	KUNIT_CASE(tb_test_property_parse),
+	KUNIT_CASE(tb_test_property_format),
+	KUNIT_CASE(tb_test_property_copy),
+	KUNIT_CASE(tb_test_property_parse_zero_length),
+	KUNIT_CASE(tb_test_property_parse_rootdir_overflow),
+	KUNIT_CASE(tb_test_property_merge),
+	{ }
+};
+
+static struct kunit_suite tb_test_suite = {
+	.name = "thunderbolt",
+	.test_cases = tb_test_cases,
+};
+
+kunit_test_suite(tb_test_suite);