Change in coreboot[master]: soc/intel/common: Implement TBT firmware authentication validity check

[Tim Wawrzynczak (Code Review)]

Tim Wawrzynczak has submitted this change. ( https://review.coreboot.org/c/coreboot/+/54693 )

Change subject: soc/intel/common: Implement TBT firmware authentication validity check
......................................................................

soc/intel/common: Implement TBT firmware authentication validity check

After Thunderbolt firmware is downloaded to IMR, its authentication
validity needs to be checked. This change implements the valid_tbt_auth
function. Thunderbolt DSD and its corresponding IMR_VAID will be
present to kernel only if its authentication is successful.

BUG=b:188695995
TEST=Validated TGL TBT firmware authentication and its IMR_VALID
into SSDT which is properly present to kernel.

Signed-off-by: John Zhao 
Change-Id: I3c9dda341ae6f19a2a8c85f92edda3dfa08c917a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54693
Tested-by: build bot (Jenkins) 
Reviewed-by: Tim Wawrzynczak 
---
M src/soc/intel/common/block/usb4/usb4.c
1 file changed, 11 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Tim Wawrzynczak: Looks good to me, approved

diff --git a/src/soc/intel/common/block/usb4/usb4.c b/src/soc/intel/common/block/usb4/usb4.c
index f3c81dc..923ec55 100644
--- a/src/soc/intel/common/block/usb4/usb4.c
+++ b/src/soc/intel/common/block/usb4/usb4.c
@@ -6,7 +6,10 @@
 #include <device/pci.h>
 #include <device/pci_def.h>
 #include <device/pci_ids.h>
+#include <intelblocks/systemagent.h>
 #include <soc/pci_devs.h>
+#include <soc/pcr_ids.h>
+#include <soc/tcss.h>

#define INTEL_TBT_IMR_VALID_UUID	"C44D002F-69F9-4E7D-A904-A7BAABDF43F7"
 #define INTEL_TBT_WAKE_SUPPORTED_UUID	"6C501103-C189-4296-BA72-9BF5A26EBE5D"
@@ -24,10 +27,18 @@
    }
 }

+static int valid_tbt_auth(void)
+{
+	return REGBAR32(PID_IOM, IOM_CSME_IMR_TBT_STATUS) & TBT_VALID_AUTHENTICATION;
+}
+
 static void tbt_dma_fill_ssdt(const struct device *dev)
 {
    struct acpi_dp *dsd, *pkg;

+	if (!valid_tbt_auth())
+		return;
+
    acpigen_write_scope(acpi_device_path(dev));

dsd = acpi_dp_new_table("_DSD");