thunderbolt: Add support for native USB4 _OSC

ACPI 6.4 introduced a new _OSC capability used to negotiate whether the
OS is supposed to use Software (native) or Firmware based Connection
Manager. If the native support is granted then there are set of bits
that enable/disable different tunnel types that the Software Connection
Manager is allowed to tunnel.

This adds support for this new USB4 _OSC accordingly. When PCIe
tunneling is disabled then the driver switches security level to be
"nopcie" following the security level 5 used in Firmware based
Connection Manager.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/thunderbolt/acpi.c b/drivers/thunderbolt/acpi.c
index a5f988a9f948..6ed003961308 100644
--- a/drivers/thunderbolt/acpi.c
+++ b/drivers/thunderbolt/acpi.c
@@ -115,3 +115,68 @@ void tb_acpi_add_links(struct tb_nhi *nhi)
 	if (ACPI_FAILURE(status))
 		dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n");
 }
+
+/**
+ * tb_acpi_is_native() - Did the platform grant native TBT/USB4 control
+ *
+ * Returns %true if the platform granted OS native control over
+ * TBT/USB4. In this case software based connection manager can be used,
+ * otherwise there is firmware based connection manager running.
+ */
+bool tb_acpi_is_native(void)
+{
+	return osc_sb_native_usb4_support_confirmed &&
+	       osc_sb_native_usb4_control;
+}
+
+/**
+ * tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform
+ *
+ * When software based connection manager is used, this function
+ * returns %true if platform allows native USB3 tunneling.
+ */
+bool tb_acpi_may_tunnel_usb3(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_USB3_TUNNELING;
+	return true;
+}
+
+/**
+ * tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform
+ *
+ * When software based connection manager is used, this function
+ * returns %true if platform allows native DP tunneling.
+ */
+bool tb_acpi_may_tunnel_dp(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_DP_TUNNELING;
+	return true;
+}
+
+/**
+ * tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform
+ *
+ * When software based connection manager is used, this function
+ * returns %true if platform allows native PCIe tunneling.
+ */
+bool tb_acpi_may_tunnel_pcie(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_PCIE_TUNNELING;
+	return true;
+}
+
+/**
+ * tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed
+ *
+ * When software based connection manager is used, this function
+ * returns %true if platform allows XDomain connections.
+ */
+bool tb_acpi_is_xdomain_allowed(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_XDOMAIN;
+	return true;
+}