ArmPkg/ArmGic: Implement GICv2-only version of GIC driver

Most platforms do not require the flexibility of the ordinary GIC
driver, which supports both GICv2 and GICv3+, and decides at runtime
which version to use.

So expose a GICv2 only version, which only supports a GICv2.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

ArmPkg/ArmPkg.dsc

@@ -125,6 +125,7 @@
   ArmPkg/Drivers/CpuDxe/CpuDxe.inf
   ArmPkg/Drivers/CpuPei/CpuPei.inf
   ArmPkg/Drivers/ArmGic/ArmGicDxe.inf
+  ArmPkg/Drivers/ArmGic/ArmGicV2Dxe.inf
   ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.inf
   ArmPkg/Drivers/TimerDxe/TimerDxe.inf
 

ArmPkg/Drivers/ArmGic/ArmGicV2Dxe.inf

@@ -0,0 +1,51 @@
+#/** @file
+#
+#  Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
+#  Copyright (c) 2012 - 2017, ARM Ltd. All rights reserved.<BR>
+#  Copyright (c) 2025, Google LLC. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 1.30
+  BASE_NAME                      = ArmGicV2Dxe
+  FILE_GUID                      = 8562bf1e-f816-44fa-82d6-763f3b131e6d
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = GicV2DxeInitialize
+
+[Sources.common]
+  ArmGicCommonDxe.c
+  ArmGicDxe.c
+  ArmGicDxe.h
+  GicV2/ArmGicV2Dxe.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmLib
+  BaseLib
+  DebugLib
+  IoLib
+  PcdLib
+  PrintLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+  UefiLib
+
+[Protocols]
+  gHardwareInterruptProtocolGuid  ## PRODUCES
+  gHardwareInterrupt2ProtocolGuid ## PRODUCES
+  gEfiCpuArchProtocolGuid         ## CONSUMES ## NOTIFY
+
+[Pcd.common]
+  gArmTokenSpaceGuid.PcdGicDistributorBase
+  gArmTokenSpaceGuid.PcdGicInterruptInterfaceBase
+
+[Depex]
+  TRUE