OvmfPkg/PlatformPei/MemTypeInfo.c

   1 /** @file
   2   Produce a default memory type information HOB unless we can determine, from
   3   the existence of the "MemoryTypeInformation" variable, that the DXE IPL PEIM
   4   will produce the HOB.
   5
   6   Copyright (C) 2017-2020, Red Hat, Inc.
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9 **/
  10
  11 #include <Guid/MemoryTypeInformation.h>
  12 #include <Library/BaseLib.h>
  13 #include <Library/DebugLib.h>
  14 #include <Library/HobLib.h>
  15 #include <Library/PcdLib.h>
  16 #include <Library/PeiServicesLib.h>
  17 #include <Ppi/ReadOnlyVariable2.h>
  18 #include <Uefi/UefiMultiPhase.h>
  19
  20 #include "Platform.h"
  21
  22 //
  23 // The NumberOfPages values below are ad-hoc. They are updated sporadically at
  24 // best (please refer to git-blame for past updates). The values capture a set
  25 // of BIN hints that made sense at a particular time, for some (now likely
  26 // unknown) workloads / boot paths.
  27 //
  28 STATIC EFI_MEMORY_TYPE_INFORMATION mDefaultMemoryTypeInformation[] = {
  29   { EfiACPIMemoryNVS,       0x004 },
  30   { EfiACPIReclaimMemory,   0x008 },
  31   { EfiReservedMemoryType,  0x004 },
  32   { EfiRuntimeServicesData, 0x024 },
  33   { EfiRuntimeServicesCode, 0x030 },
  34   { EfiMaxMemoryType,       0x000 }
  35 };
  36
  37 STATIC
  38 VOID
  39 BuildMemTypeInfoHob (
  40   VOID
  41   )
  42 {
  43   BuildGuidDataHob (
  44     &gEfiMemoryTypeInformationGuid,
  45     mDefaultMemoryTypeInformation,
  46     sizeof mDefaultMemoryTypeInformation
  47     );
  48   DEBUG ((DEBUG_INFO, "%a: default memory type information HOB built\n",
  49     __FUNCTION__));
  50 }
  51
  52 /**
  53   Notification function called when EFI_PEI_READ_ONLY_VARIABLE2_PPI becomes
  54   available.
  55
  56   @param[in] PeiServices      Indirect reference to the PEI Services Table.
  57   @param[in] NotifyDescriptor Address of the notification descriptor data
  58                               structure.
  59   @param[in] Ppi              Address of the PPI that was installed.
  60
  61   @return  Status of the notification. The status code returned from this
  62            function is ignored.
  63 **/
  64 STATIC
  65 EFI_STATUS
  66 EFIAPI
  67 OnReadOnlyVariable2Available (
  68   IN EFI_PEI_SERVICES           **PeiServices,
  69   IN EFI_PEI_NOTIFY_DESCRIPTOR  *NotifyDescriptor,
  70   IN VOID                       *Ppi
  71   )
  72 {
  73   EFI_PEI_READ_ONLY_VARIABLE2_PPI *ReadOnlyVariable2;
  74   UINTN                           DataSize;
  75   EFI_STATUS                      Status;
  76
  77   DEBUG ((DEBUG_VERBOSE, "%a\n", __FUNCTION__));
  78
  79   //
  80   // Check if the "MemoryTypeInformation" variable exists, in the
  81   // gEfiMemoryTypeInformationGuid namespace.
  82   //
  83   ReadOnlyVariable2 = Ppi;
  84   DataSize = 0;
  85   Status = ReadOnlyVariable2->GetVariable (
  86                                 ReadOnlyVariable2,
  87                                 EFI_MEMORY_TYPE_INFORMATION_VARIABLE_NAME,
  88                                 &gEfiMemoryTypeInformationGuid,
  89                                 NULL,
  90                                 &DataSize,
  91                                 NULL
  92                                 );
  93   switch (Status) {
  94   case EFI_BUFFER_TOO_SMALL:
  95     //
  96     // The variable exists; the DXE IPL PEIM will build the HOB from it.
  97     //
  98     break;
  99   case EFI_NOT_FOUND:
 100     //
 101     // The variable does not exist; install the default memory type information
 102     // HOB.
 103     //
 104     BuildMemTypeInfoHob ();
 105     break;
 106   default:
 107     DEBUG ((DEBUG_ERROR, "%a: unexpected: GetVariable(): %r\n", __FUNCTION__,
 108       Status));
 109     ASSERT (FALSE);
 110     CpuDeadLoop ();
 111     break;
 112   }
 113
 114   return EFI_SUCCESS;
 115 }
 116
 117 //
 118 // Notification object for registering the callback, for when
 119 // EFI_PEI_READ_ONLY_VARIABLE2_PPI becomes available.
 120 //
 121 STATIC CONST EFI_PEI_NOTIFY_DESCRIPTOR mReadOnlyVariable2Notify = {
 122   (EFI_PEI_PPI_DESCRIPTOR_NOTIFY_DISPATCH |
 123    EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),  // Flags
 124   &gEfiPeiReadOnlyVariable2PpiGuid,         // Guid
 125   OnReadOnlyVariable2Available              // Notify
 126 };
 127
 128 VOID
 129 MemTypeInfoInitialization (
 130   VOID
 131   )
 132 {
 133   EFI_STATUS Status;
 134
 135   if (!FeaturePcdGet (PcdSmmSmramRequire)) {
 136     //
 137     // EFI_PEI_READ_ONLY_VARIABLE2_PPI will never be available; install
 138     // the default memory type information HOB right away.
 139     //
 140     BuildMemTypeInfoHob ();
 141     return;
 142   }
 143
 144   Status = PeiServicesNotifyPpi (&mReadOnlyVariable2Notify);
 145   if (EFI_ERROR (Status)) {
 146     DEBUG ((DEBUG_ERROR, "%a: failed to set up R/O Variable 2 callback: %r\n",
 147       __FUNCTION__, Status));
 148     ASSERT (FALSE);
 149     CpuDeadLoop ();
 150   }
 151 }