intel/apollolake: Add parameter to enable VTD in devicetree

The FSP has a parameter to enable or disable the VTD feature
(Intel's Virtualization Technology for Directed I/O). In current header
files for FSP-S (Apollo Lake and Gemini Lake) this parameter is set to
disabled per default. Therefore, if the FSP was not modified via BCT,
this feature is most likely disabled on all mainboards.

Add a chip parameter so that VTD can be enabled on mainboard level in
devicetree and therefore this feature can be activated if needed.

Change-Id: Ic0bfcf1719e1ccc678a932bf3d38c6dbce3556bc
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/31194
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/soc/intel/apollolake/chip.h b/src/soc/intel/apollolake/chip.h
index 6c2404a405..b9e368cddc 100644
--- a/src/soc/intel/apollolake/chip.h
+++ b/src/soc/intel/apollolake/chip.h
@@ -188,6 +188,12 @@ struct soc_intel_apollolake_config {
 	 * 00=1.10v, 01=1.15v, 10=1.24v, 11=1.20v (default).
 	 */
 	uint32_t PmicVdd2Voltage;
+
+	/* Option to enable VTD feature. Default is 0 which disables VTD
+	 * capability in FSP. Setting this option to 1 in devicetree will enable
+	 * the Upd parameter VtdEnable.
+	 */
+	uint8_t enable_vtd;
 };
 
 typedef struct soc_intel_apollolake_config config_t;