[PATCH v2 6/7] ArmVirtPkg/ArmVirtQemu: use first 128 MiB as permanent PEI memory

["Ard Biesheuvel" <ardb@kernel.org>]

In order to allow booting with the MMU and caches enabled really early,
we need to ensure that the code that populates the page tables can
access those page tables with the statically defined ID map active.

So let's put the permanent PEI RAM in the first 128 MiB of memory, which
we will cover with this initial ID map (as it is the minimum supported
DRAM size for ArmVirtQemu).

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 ArmVirtPkg/MemoryInitPei/MemoryInitPeim.c   | 105 ++++++++++++++++++++
 ArmVirtPkg/MemoryInitPei/MemoryInitPeim.inf |  68 +++++++++++++
 2 files changed, 173 insertions(+)

diff --git a/ArmVirtPkg/MemoryInitPei/MemoryInitPeim.c b/ArmVirtPkg/MemoryInitPei/MemoryInitPeim.c
new file mode 100644
index 000000000000..d61fa55efaaa
--- /dev/null
+++ b/ArmVirtPkg/MemoryInitPei/MemoryInitPeim.c
@@ -0,0 +1,105 @@
+/** @file
+
+  Copyright (c) 2011, ARM Limited. All rights reserved.
+  Copyright (c) 2022, Google LLC. All rights reserved.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+#include <Library/ArmPlatformLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/PeimEntryPoint.h>
+#include <Library/PeiServicesLib.h>
+#include <Library/PcdLib.h>
+#include <Guid/MemoryTypeInformation.h>
+
+EFI_STATUS
+EFIAPI
+MemoryPeim (
+  IN EFI_PHYSICAL_ADDRESS  UefiMemoryBase,
+  IN UINT64                UefiMemorySize
+  );
+
+/**
+  Build the memory type information HOB that describes how many pages of each
+  type to preallocate when initializing the GCD memory map.
+**/
+VOID
+EFIAPI
+BuildMemoryTypeInformationHob (
+  VOID
+  )
+{
+  EFI_MEMORY_TYPE_INFORMATION  Info[10];
+
+  Info[0].Type          = EfiACPIReclaimMemory;
+  Info[0].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiACPIReclaimMemory);
+  Info[1].Type          = EfiACPIMemoryNVS;
+  Info[1].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiACPIMemoryNVS);
+  Info[2].Type          = EfiReservedMemoryType;
+  Info[2].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiReservedMemoryType);
+  Info[3].Type          = EfiRuntimeServicesData;
+  Info[3].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiRuntimeServicesData);
+  Info[4].Type          = EfiRuntimeServicesCode;
+  Info[4].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiRuntimeServicesCode);
+  Info[5].Type          = EfiBootServicesCode;
+  Info[5].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiBootServicesCode);
+  Info[6].Type          = EfiBootServicesData;
+  Info[6].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiBootServicesData);
+  Info[7].Type          = EfiLoaderCode;
+  Info[7].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiLoaderCode);
+  Info[8].Type          = EfiLoaderData;
+  Info[8].NumberOfPages = PcdGet32 (PcdMemoryTypeEfiLoaderData);
+
+  // Terminator for the list
+  Info[9].Type          = EfiMaxMemoryType;
+  Info[9].NumberOfPages = 0;
+
+  BuildGuidDataHob (&gEfiMemoryTypeInformationGuid, &Info, sizeof (Info));
+}
+
+/**
+  Module entry point.
+
+  @param[in]    FileHandle    Handle of the file being invoked.
+  @param[in]    PeiServices   Describes the list of possible PEI Services.
+
+  @return       EFI_SUCCESS unless the operation failed.
+**/
+EFI_STATUS
+EFIAPI
+InitializeMemory (
+  IN       EFI_PEI_FILE_HANDLE  FileHandle,
+  IN CONST EFI_PEI_SERVICES     **PeiServices
+  )
+{
+  UINTN       UefiMemoryBase;
+  EFI_STATUS  Status;
+
+  ASSERT (PcdGet64 (PcdSystemMemorySize) >= SIZE_128MB);
+  ASSERT (PcdGet64 (PcdSystemMemoryBase) < (UINT64)MAX_ALLOC_ADDRESS);
+
+  //
+  // Put the permanent PEI memory in the first 128 MiB of DRAM so that
+  // it is covered by the statically configured ID map.
+  //
+  UefiMemoryBase = (UINTN)PcdGet64 (PcdSystemMemoryBase) + SIZE_128MB
+                   - FixedPcdGet32 (PcdSystemMemoryUefiRegionSize);
+
+  Status = PeiServicesInstallPeiMemory (
+             UefiMemoryBase,
+             FixedPcdGet32 (PcdSystemMemoryUefiRegionSize)
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  Status = MemoryPeim (
+             UefiMemoryBase,
+             FixedPcdGet32 (PcdSystemMemoryUefiRegionSize)
+             );
+  ASSERT_EFI_ERROR (Status);
+
+  return Status;
+}
diff --git a/ArmVirtPkg/MemoryInitPei/MemoryInitPeim.inf b/ArmVirtPkg/MemoryInitPei/MemoryInitPeim.inf
new file mode 100644
index 000000000000..f4492719c350
--- /dev/null
+++ b/ArmVirtPkg/MemoryInitPei/MemoryInitPeim.inf
@@ -0,0 +1,68 @@
+## @file
+#  Implementation of MemoryInitPeim that uses the first 128 MiB at the base of
+#  DRAM as permanent PEI memory
+#
+#  Copyright (c) 2011-2014, ARM Ltd. All rights reserved.<BR>
+#  Copyright (c) 2022, Google LLC. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 1.27
+  BASE_NAME                      = MemoryInit
+  FILE_GUID                      = 0fbffd44-f98f-4e1c-9922-e9b21f13c3f8
+  MODULE_TYPE                    = PEIM
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = InitializeMemory
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 EBC ARM
+#
+
+[Sources]
+  MemoryInitPeim.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+
+[LibraryClasses]
+  PeimEntryPoint
+  DebugLib
+  HobLib
+  ArmLib
+  ArmPlatformLib
+  MemoryInitPeiLib
+
+[Guids]
+  gEfiMemoryTypeInformationGuid
+
+[FeaturePcd]
+  gEmbeddedTokenSpaceGuid.PcdPrePiProduceMemoryTypeInformationHob
+
+[FixedPcd]
+  gArmPlatformTokenSpaceGuid.PcdSystemMemoryUefiRegionSize
+
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiACPIReclaimMemory
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiACPIMemoryNVS
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiReservedMemoryType
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiRuntimeServicesData
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiRuntimeServicesCode
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiBootServicesCode
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiBootServicesData
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiLoaderCode
+  gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiLoaderData
+
+[Pcd]
+  gArmTokenSpaceGuid.PcdSystemMemoryBase
+  gArmTokenSpaceGuid.PcdSystemMemorySize
+
+[Depex]
+  TRUE
-- 
2.35.1