ArmPkg/ArmLib: avoid cache maintenance in PEIMs when executing in place

On some platforms, performing cache maintenance on regions that are backed
by NOR flash result in SErrors. Since cache maintenance is unnecessary in
that case, create a PEIM specific version that only performs said cache
maintenance in its constructor if the module is shadowed in RAM. To avoid
performing the cache maintenance if the MMU code is not used to begin with,
check that explicitly in the constructor.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Heyi Guo <heyi.guo@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

ArmPkg/Library/ArmLib/AArch64/AArch64Lib.inf

@@ -32,7 +32,7 @@
 
   ../Common/AArch64/ArmLibSupport.S
   ../Common/ArmLib.c
-  AArch64LibConstructor.c
+  AArch64BaseLibConstructor.c
 
 [Packages]
   ArmPkg/ArmPkg.dec

ArmPkg/Library/ArmLib/AArch64/AArch64LibPei.inf

@@ -0,0 +1,43 @@
+#/** @file
+#
+# Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
+# Portions copyright (c) 2011 - 2014, ARM Limited. All rights reserved.
+#
+#  This program and the accompanying materials
+#  are licensed and made available under the terms and conditions of the BSD License
+#  which accompanies this distribution. The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = AArch64Lib
+  FILE_GUID                      = ef20ddf5-b334-47b3-94cf-52ff44c29138
+  MODULE_TYPE                    = PEIM
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ArmLib|PEIM PEI_CORE
+  CONSTRUCTOR                    = AArch64LibConstructor
+
+[Sources.AARCH64]
+  AArch64Lib.c
+  AArch64Mmu.c
+  AArch64ArchTimer.c
+  ArmLibSupportV8.S
+  AArch64Support.S
+  AArch64ArchTimerSupport.S
+
+  ../Common/AArch64/ArmLibSupport.S
+  ../Common/ArmLib.c
+  AArch64PeiLibConstructor.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  MemoryAllocationLib
+  CacheMaintenanceLib

ArmPkg/Library/ArmLib/AArch64/AArch64Mmu.c

@@ -26,6 +26,8 @@
 // We use this index definition to define an invalid block entry
 #define TT_ATTR_INDX_INVALID    ((UINT32)~0)
 
+INT32 HaveMmuRoutines = 1;
+
 STATIC
 UINT64
 ArmMemoryAttributeToPageAttribute (

ArmPkg/Library/ArmLib/AArch64/AArch64PeiLibConstructor.c

@@ -0,0 +1,75 @@
+#/* @file
+#
+#  Copyright (c) 2016, Linaro Limited. All rights reserved.
+#
+#  This program and the accompanying materials
+#  are licensed and made available under the terms and conditions of the BSD License
+#  which accompanies this distribution.  The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php
+#
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#*/
+
+#include <Base.h>
+
+#include <Library/ArmLib.h>
+#include <Library/CacheMaintenanceLib.h>
+#include <Library/DebugLib.h>
+
+//
+// This is a hack. We define a weak symbol with external linkage, which may or
+// may not be overridden by a non-weak alternative that is defined with a non
+// zero value in the object that contains the MMU routines. Since static
+// libraries are pulled in on a per-object basis, and since the MMU object will
+// only be pulled in if any of its other symbols are referenced by the client
+// module, we can use the value below to figure out whether the MMU routines are
+// in use by this module, and decide whether cache maintenance of the function
+// ArmReplaceLiveTranslationEntry () is required.
+//
+INT32 __attribute__((weak)) HaveMmuRoutines;
+
+EFI_STATUS
+EFIAPI
+AArch64LibConstructor (
+  IN       EFI_PEI_FILE_HANDLE       FileHandle,
+  IN CONST EFI_PEI_SERVICES          **PeiServices
+  )
+{
+  extern UINT32             ArmReplaceLiveTranslationEntrySize;
+
+  EFI_FV_FILE_INFO          FileInfo;
+  EFI_STATUS                Status;
+
+  if (HaveMmuRoutines == 0) {
+    return RETURN_SUCCESS;
+  }
+
+  ASSERT (FileHandle != NULL);
+
+  Status = (*PeiServices)->FfsGetFileInfo (FileHandle, &FileInfo);
+  ASSERT_EFI_ERROR (Status);
+
+  //
+  // Some platforms do not cope very well with cache maintenance being
+  // performed on regions backed by NOR flash. Since the cache maintenance
+  // is unnecessary to begin with in that case, perform it only when not
+  // executing in place.
+  //
+  if ((UINTN)FileInfo.Buffer <= (UINTN)ArmReplaceLiveTranslationEntry &&
+      ((UINTN)FileInfo.Buffer + FileInfo.BufferSize >=
+       (UINTN)ArmReplaceLiveTranslationEntry + ArmReplaceLiveTranslationEntrySize)) {
+    DEBUG ((EFI_D_INFO, "ArmLib: skipping cache maintence on XIP PEIM\n"));
+  } else {
+    DEBUG ((EFI_D_INFO, "ArmLib: performing cache maintence on shadowed PEIM\n"));
+    //
+    // The ArmReplaceLiveTranslationEntry () helper function may be invoked
+    // with the MMU off so we have to ensure that it gets cleaned to the PoC
+    //
+    WriteBackDataCacheRange (ArmReplaceLiveTranslationEntry,
+      ArmReplaceLiveTranslationEntrySize);
+  }
+
+  return RETURN_SUCCESS;
+}