[PATCH v9 01/19] ArmPkg: PCD to select conduit for monitor calls

["PierreGondois" <pierre.gondois@arm.com>]

From: Sami Mujawar <sami.mujawar@arm.com>

Define a PCD 'PcdMonitorConduitHvc' to select the conduit to use for
monitor calls. PcdMonitorConduitHvc is defined as FALSE by default,
meaning the SMC conduit is enabled as default.

Adding PcdMonitorConduitHvc allows selection of HVC conduit to be used
by virtual firmware implementations.

Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 ArmPkg/ArmPkg.dec | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
index cfb6fe602485..99cb024d0f93 100644
--- a/ArmPkg/ArmPkg.dec
+++ b/ArmPkg/ArmPkg.dec
@@ -2,7 +2,7 @@
 # ARM processor package.
 #
 # Copyright (c) 2009 - 2010, Apple Inc. All rights reserved.<BR>
-# Copyright (c) 2011 - 2021, ARM Limited. All rights reserved.
+# Copyright (c) 2011 - 2022, ARM Limited. All rights reserved.
 # Copyright (c) 2021, Ampere Computing LLC. All rights reserved.
 #
 #    SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -134,6 +134,11 @@ [PcdsFeatureFlag.common]
   # Define if the GICv3 controller should use the GICv2 legacy
   gArmTokenSpaceGuid.PcdArmGicV3WithV2Legacy|FALSE|BOOLEAN|0x00000042
 
+  ## Define the conduit to use for monitor calls.
+  # Default PcdMonitorConduitHvc = FALSE, conduit = SMC
+  # If PcdMonitorConduitHvc = TRUE, conduit = HVC
+  gArmTokenSpaceGuid.PcdMonitorConduitHvc|FALSE|BOOLEAN|0x00000047
+
 [PcdsFeatureFlag.ARM]
   # Whether to map normal memory as non-shareable. FALSE is the safe choice, but
   # TRUE may be appropriate to fix performance problems if you don't care about
-- 
2.25.1