From aa0f522471b3832a8ced9d5ca22d0a7d9ea678a2 Mon Sep 17 00:00:00 2001
From: Pierre Gondois <Pierre.Gondois@arm.com>
Date: Fri, 28 Oct 2022 17:32:43 +0200
Subject: [PATCH] ArmPkg/ArmMonitorLib: Add ArmMonitorLib

The ArmMonitorLib provides an abstract interface to issue
an HyperVisor Call (HVC) or System Monitor Call (SMC) depending
on the default conduit.
The PcdMonitorConduitHvc PCD allows to select the default conduit.

Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 ArmPkg/ArmPkg.dsc                             |  1 +
 ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.c  | 34 +++++++++++++++++++
 .../Library/ArmMonitorLib/ArmMonitorLib.inf   | 29 ++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.c
 create mode 100644 ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.inf

diff --git a/ArmPkg/ArmPkg.dsc b/ArmPkg/ArmPkg.dsc
index 59fd8f295d..3afd212f47 100644
--- a/ArmPkg/ArmPkg.dsc
+++ b/ArmPkg/ArmPkg.dsc
@@ -135,6 +135,7 @@
   ArmPkg/Library/ArmSmcLibNull/ArmSmcLibNull.inf
   ArmPkg/Library/ArmHvcLib/ArmHvcLib.inf
   ArmPkg/Library/ArmSvcLib/ArmSvcLib.inf
+  ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.inf
   ArmPkg/Library/OpteeLib/OpteeLib.inf
 
   ArmPkg/Filesystem/SemihostFs/SemihostFs.inf
diff --git a/ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.c b/ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.c
new file mode 100644
index 0000000000..741f5c6157
--- /dev/null
+++ b/ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.c
@@ -0,0 +1,34 @@
+/** @file
+  Arm Monitor Library.
+
+  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/ArmHvcLib.h>
+#include <Library/ArmMonitorLib.h>
+#include <Library/ArmSmcLib.h>
+#include <Library/PcdLib.h>
+
+/** Monitor call.
+
+  An HyperVisor Call (HVC) or System Monitor Call (SMC) will be issued
+  depending on the default conduit. PcdMonitorConduitHvc determines the type
+  of the call: if true, do an HVC.
+
+  @param [in,out]  Args    Arguments for the HVC/SMC.
+**/
+VOID
+EFIAPI
+ArmMonitorCall (
+  IN OUT ARM_MONITOR_ARGS  *Args
+  )
+{
+  if (FeaturePcdGet (PcdMonitorConduitHvc)) {
+    ArmCallHvc ((ARM_HVC_ARGS *)Args);
+  } else {
+    ArmCallSmc ((ARM_SMC_ARGS *)Args);
+  }
+}
diff --git a/ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.inf b/ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.inf
new file mode 100644
index 0000000000..f504cb80f1
--- /dev/null
+++ b/ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.inf
@@ -0,0 +1,29 @@
+## @file
+#  Arm Monitor Library
+#
+#  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = ArmMonitorLib
+  FILE_GUID                      = F918DACB-FBB8-4CB6-A61D-08E75AF0E7CD
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ArmMonitorLib
+
+[Sources]
+  ArmMonitorLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmHvcLib
+  ArmSmcLib
+
+[Pcd]
+  gArmTokenSpaceGuid.PcdMonitorConduitHvc