Merge: thunderbolt: Fix DP tunneling out of resource

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/2027

## BUGZILLA
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2107603

## UPSTREAM STATUS
Upstream Status: Patch has been accepted on kernel/git/torvalds/linux.git

## CONFLICTS
None

## BUILD INFORMATION
Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=50536258

## TESTING
Functional testing: TBD

Smoke test:
~~~
# uname -r
5.14.0-258.rh2107603.el9.x86_64

# cat /etc/redhat-release 
Red Hat Enterprise Linux release 9.1 (Plow)

# rpm -q --changelog kernel-5.14.0-258.rh2107603.el9.x86_64 | head -n2
* Mon Feb 06 2023 Desnes Nunes <desnesn@redhat.com> [5.14.0-258.rh2107603.el9]
- thunderbolt: Add DP OUT resource when DP tunnel is discovered (Desnes Nunes)

# lscpu | grep -m2 -e "Arch\|Model name:"
Architecture:                    x86_64
Model name:                      AMD EPYC 7742 64-Core Processor

# dmidecode | grep -A3 '^System Information'
System Information
	Manufacturer: HP
	Product Name: ProLiant DL320e Gen8 v2
	Version: Not Specified
~~~

## DESCRIPTION
This fixes the discovery of a DP tunnel by adding the new tunnelled DP OUT port accordingly to the dp_resource list

Signed-off-by: Desnes Nunes <desnesn@redhat.com>

Approved-by: Dean Nelson <dnelson@redhat.com>
Approved-by: David Arcari <darcari@redhat.com>
Approved-by: Torez Smith <torez@redhat.com>

Signed-off-by: Herton R. Krzesinski <herton@redhat.com>

Author: Herton R. Krzesinski

drivers/thunderbolt/tb.c

@@ -105,6 +105,32 @@ static void tb_remove_dp_resources(struct tb_switch *sw)
 	}
 }
 
+static void tb_discover_dp_resource(struct tb *tb, struct tb_port *port)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *p;
+
+	list_for_each_entry(p, &tcm->dp_resources, list) {
+		if (p == port)
+			return;
+	}
+
+	tb_port_dbg(port, "DP %s resource available discovered\n",
+		    tb_port_is_dpin(port) ? "IN" : "OUT");
+	list_add_tail(&port->list, &tcm->dp_resources);
+}
+
+static void tb_discover_dp_resources(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_tunnel *tunnel;
+
+	list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
+		if (tb_tunnel_is_dp(tunnel))
+			tb_discover_dp_resource(tb, tunnel->dst_port);
+	}
+}
+
 static void tb_switch_discover_tunnels(struct tb_switch *sw,
 				       struct list_head *list,
 				       bool alloc_hopids)
@@ -1446,6 +1472,8 @@ static int tb_start(struct tb *tb)
 	tb_scan_switch(tb->root_switch);
 	/* Find out tunnels created by the boot firmware */
 	tb_discover_tunnels(tb);
+	/* Add DP resources from the DP tunnels created by the boot firmware */
+	tb_discover_dp_resources(tb);
 	/*
 	 * If the boot firmware did not create USB 3.x tunnels create them
 	 * now for the whole topology.