[PATCH v1 3/7] ArmPkg/ArmLib: Add ArmReadIdIsaR5() helper

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

From: Pierre Gondois <Pierre.Gondois@arm.com>

Add a ArmReadIdIsaR5() helper function to access the AArch32
ID_ISAR5 register.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S |  7 ++++++-
 ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h      | 11 +++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S b/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S
index 0856740e3290..bc2be5331c7d 100644
--- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S
+++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S
@@ -1,7 +1,7 @@
 #------------------------------------------------------------------------------
 #
 # Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
-# Copyright (c) 2011 - 2016, ARM Limited. All rights reserved.
+# Copyright (c) 2011 - 2022, Arm Limited. All rights reserved.
 # Copyright (c) 2016, Linaro Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -167,4 +167,9 @@ ASM_FUNC (ArmGetPhysicalAddressBits)
   movge   r0, #40                 // 40 bits if LPAE
   bx      lr
 
+// UINTN ArmReadIdIsaR5(VOID)
+ASM_FUNC(ArmReadIdIsaR5)
+  mrc     p15, 0, r0, c0, c2, 5
+  bx      lr
+
 ASM_FUNCTION_REMOVE_IF_UNREFERENCED
diff --git a/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h b/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h
index 404ff92c4e06..1cfd6e5f65ac 100644
--- a/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h
+++ b/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h
@@ -1,6 +1,7 @@
 /** @file
 
   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+  Copyright (c) 2022, Arm Ltd. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -66,4 +67,14 @@ ArmReadIdPfr1 (
   VOID
   );
 
+/** Reads the ID_ISAR5 register.
+
+   @return The contents of the ID_ISAR5 register.
+**/
+UINTN
+EFIAPI
+ArmReadIdIsaR5 (
+  VOID
+  );
+
 #endif // ARM_V7_LIB_H_
-- 
2.25.1