ArmPkg/Library/ArmLib/AArch64/AArch64PeiLibConstructor.c

   1 #/* @file
   2 #
   3 #  Copyright (c) 2016, Linaro Limited. All rights reserved.
   4 #
   5 #  This program and the accompanying materials
   6 #  are licensed and made available under the terms and conditions of the BSD License
   7 #  which accompanies this distribution.  The full text of the license may be found at
   8 #  http://opensource.org/licenses/bsd-license.php
   9 #
  10 #  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 #  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 #
  13 #*/
  14
  15 #include <Base.h>
  16
  17 #include <Library/ArmLib.h>
  18 #include <Library/CacheMaintenanceLib.h>
  19 #include <Library/DebugLib.h>
  20
  21 //
  22 // This is a hack. We define a weak symbol with external linkage, which may or
  23 // may not be overridden by a non-weak alternative that is defined with a non
  24 // zero value in the object that contains the MMU routines. Since static
  25 // libraries are pulled in on a per-object basis, and since the MMU object will
  26 // only be pulled in if any of its other symbols are referenced by the client
  27 // module, we can use the value below to figure out whether the MMU routines are
  28 // in use by this module, and decide whether cache maintenance of the function
  29 // ArmReplaceLiveTranslationEntry () is required.
  30 //
  31 INT32 __attribute__((weak)) HaveMmuRoutines;
  32
  33 EFI_STATUS
  34 EFIAPI
  35 AArch64LibConstructor (
  36   IN       EFI_PEI_FILE_HANDLE       FileHandle,
  37   IN CONST EFI_PEI_SERVICES          **PeiServices
  38   )
  39 {
  40   extern UINT32             ArmReplaceLiveTranslationEntrySize;
  41
  42   EFI_FV_FILE_INFO          FileInfo;
  43   EFI_STATUS                Status;
  44
  45   if (HaveMmuRoutines == 0) {
  46     return RETURN_SUCCESS;
  47   }
  48
  49   ASSERT (FileHandle != NULL);
  50
  51   Status = (*PeiServices)->FfsGetFileInfo (FileHandle, &FileInfo);
  52   ASSERT_EFI_ERROR (Status);
  53
  54   //
  55   // Some platforms do not cope very well with cache maintenance being
  56   // performed on regions backed by NOR flash. Since the cache maintenance
  57   // is unnecessary to begin with in that case, perform it only when not
  58   // executing in place.
  59   //
  60   if ((UINTN)FileInfo.Buffer <= (UINTN)ArmReplaceLiveTranslationEntry &&
  61       ((UINTN)FileInfo.Buffer + FileInfo.BufferSize >=
  62        (UINTN)ArmReplaceLiveTranslationEntry + ArmReplaceLiveTranslationEntrySize)) {
  63     DEBUG ((EFI_D_INFO, "ArmLib: skipping cache maintence on XIP PEIM\n"));
  64   } else {
  65     DEBUG ((EFI_D_INFO, "ArmLib: performing cache maintence on shadowed PEIM\n"));
  66     //
  67     // The ArmReplaceLiveTranslationEntry () helper function may be invoked
  68     // with the MMU off so we have to ensure that it gets cleaned to the PoC
  69     //
  70     WriteBackDataCacheRange (ArmReplaceLiveTranslationEntry,
  71       ArmReplaceLiveTranslationEntrySize);
  72   }
  73
  74   return RETURN_SUCCESS;
  75 }