UefiCpuPkg/CpuMpPei/Microcode.c

   1 /** @file
   2   Implementation of loading microcode on processors.
   3
   4   Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>
   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 "CpuMpPei.h"
  16
  17 /**
  18   Get microcode update signature of currently loaded microcode update.
  19
  20   @return  Microcode signature.
  21
  22 **/
  23 UINT32
  24 GetCurrentMicrocodeSignature (
  25   VOID
  26   )
  27 {
  28   UINT64 Signature;
  29
  30   AsmWriteMsr64 (EFI_MSR_IA32_BIOS_SIGN_ID, 0);
  31   AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, NULL);
  32   Signature = AsmReadMsr64 (EFI_MSR_IA32_BIOS_SIGN_ID);
  33   return (UINT32) RShiftU64 (Signature, 32);
  34 }
  35
  36 /**
  37   Detect whether specified processor can find matching microcode patch and load it.
  38
  39 **/
  40 VOID
  41 MicrocodeDetect (
  42   VOID
  43   )
  44 {
  45   UINT64                                  MicrocodePatchAddress;
  46   UINT64                                  MicrocodePatchRegionSize;
  47   UINT32                                  ExtendedTableLength;
  48   UINT32                                  ExtendedTableCount;
  49   EFI_CPU_MICROCODE_EXTENDED_TABLE        *ExtendedTable;
  50   EFI_CPU_MICROCODE_EXTENDED_TABLE_HEADER *ExtendedTableHeader;
  51   EFI_CPU_MICROCODE_HEADER                *MicrocodeEntryPoint;
  52   UINTN                                   MicrocodeEnd;
  53   UINTN                                   Index;
  54   UINT8                                   PlatformId;
  55   UINT32                                  RegEax;
  56   UINT32                                  CurrentRevision;
  57   UINT32                                  LatestRevision;
  58   UINTN                                   TotalSize;
  59   UINT32                                  CheckSum32;
  60   BOOLEAN                                 CorrectMicrocode;
  61   MICROCODE_INFO                          MicrocodeInfo;
  62
  63   ZeroMem (&MicrocodeInfo, sizeof (MICROCODE_INFO));
  64   MicrocodePatchAddress    = PcdGet64 (PcdCpuMicrocodePatchAddress);
  65   MicrocodePatchRegionSize = PcdGet64 (PcdCpuMicrocodePatchRegionSize);
  66   if (MicrocodePatchRegionSize == 0) {
  67     //
  68     // There is no microcode patches
  69     //
  70     return;
  71   }
  72
  73   CurrentRevision = GetCurrentMicrocodeSignature ();
  74   if (CurrentRevision != 0) {
  75     //
  76     // Skip loading microcode if it has been loaded successfully
  77     //
  78     return;
  79   }
  80
  81   ExtendedTableLength = 0;
  82   //
  83   // Here data of CPUID leafs have not been collected into context buffer, so
  84   // GetProcessorCpuid() cannot be used here to retrieve CPUID data.
  85   //
  86   AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, NULL);
  87
  88   //
  89   // The index of platform information resides in bits 50:52 of MSR IA32_PLATFORM_ID
  90   //
  91   PlatformId = (UINT8) AsmMsrBitFieldRead64 (EFI_MSR_IA32_PLATFORM_ID, 50, 52);
  92
  93   LatestRevision = 0;
  94   MicrocodeEnd = (UINTN) (MicrocodePatchAddress + MicrocodePatchRegionSize);
  95   MicrocodeEntryPoint = (EFI_CPU_MICROCODE_HEADER *) (UINTN) MicrocodePatchAddress;
  96   do {
  97     //
  98     // Check if the microcode is for the Cpu and the version is newer
  99     // and the update can be processed on the platform
 100     //
 101     CorrectMicrocode = FALSE;
 102     if (MicrocodeEntryPoint->HeaderVersion == 0x1) {
 103       //
 104       // It is the microcode header. It is not the padding data between microcode patches
 105       // because the padding data should not include 0x00000001 and it should be the repeated
 106       // byte format (like 0xXYXYXYXY....).
 107       //
 108       if (MicrocodeEntryPoint->ProcessorId == RegEax &&
 109           MicrocodeEntryPoint->UpdateRevision > LatestRevision &&
 110           (MicrocodeEntryPoint->ProcessorFlags & (1 << PlatformId))
 111           ) {
 112         if (MicrocodeEntryPoint->DataSize == 0) {
 113           CheckSum32 = CalculateSum32 ((UINT32 *)MicrocodeEntryPoint, 2048);
 114         } else {
 115           CheckSum32 = CalculateSum32 ((UINT32 *)MicrocodeEntryPoint, MicrocodeEntryPoint->DataSize + sizeof(EFI_CPU_MICROCODE_HEADER));
 116         }
 117         if (CheckSum32 == 0) {
 118           CorrectMicrocode = TRUE;
 119         }
 120       } else if ((MicrocodeEntryPoint->DataSize != 0) &&
 121                  (MicrocodeEntryPoint->UpdateRevision > LatestRevision)) {
 122         ExtendedTableLength = MicrocodeEntryPoint->TotalSize - (MicrocodeEntryPoint->DataSize + sizeof (EFI_CPU_MICROCODE_HEADER));
 123         if (ExtendedTableLength != 0) {
 124           //
 125           // Extended Table exist, check if the CPU in support list
 126           //
 127           ExtendedTableHeader = (EFI_CPU_MICROCODE_EXTENDED_TABLE_HEADER *)((UINT8 *)(MicrocodeEntryPoint) + MicrocodeEntryPoint->DataSize + sizeof (EFI_CPU_MICROCODE_HEADER));
 128           //
 129           // Calculate Extended Checksum
 130           //
 131           if ((ExtendedTableLength % 4) == 0) {
 132             CheckSum32 = CalculateSum32 ((UINT32 *)ExtendedTableHeader, ExtendedTableLength);
 133             if (CheckSum32 == 0) {
 134               //
 135               // Checksum correct
 136               //
 137               ExtendedTableCount = ExtendedTableHeader->ExtendedSignatureCount;
 138               ExtendedTable      = (EFI_CPU_MICROCODE_EXTENDED_TABLE *)(ExtendedTableHeader + 1);
 139               for (Index = 0; Index < ExtendedTableCount; Index ++) {
 140                 CheckSum32 = CalculateSum32 ((UINT32 *)ExtendedTable, sizeof(EFI_CPU_MICROCODE_EXTENDED_TABLE));
 141                 if (CheckSum32 == 0) {
 142                   //
 143                   // Verify Header
 144                   //
 145                   if ((ExtendedTable->ProcessorSignature == RegEax) &&
 146                       (ExtendedTable->ProcessorFlag & (1 << PlatformId)) ) {
 147                     //
 148                     // Find one
 149                     //
 150                     CorrectMicrocode = TRUE;
 151                     break;
 152                   }
 153                 }
 154                 ExtendedTable ++;
 155               }
 156             }
 157           }
 158         }
 159       }
 160     } else {
 161       //
 162       // It is the padding data between the microcode patches for microcode patches alignment.
 163       // Because the microcode patch is the multiple of 1-KByte, the padding data should not
 164       // exist if the microcode patch alignment value is not larger than 1-KByte. So, the microcode
 165       // alignment value should be larger than 1-KByte. We could skip SIZE_1KB padding data to
 166       // find the next possible microcode patch header.
 167       //
 168       MicrocodeEntryPoint = (EFI_CPU_MICROCODE_HEADER *) (((UINTN) MicrocodeEntryPoint) + SIZE_1KB);
 169       continue;
 170     }
 171     //
 172     // Get the next patch.
 173     //
 174     if (MicrocodeEntryPoint->DataSize == 0) {
 175       TotalSize = 2048;
 176     } else {
 177       TotalSize = MicrocodeEntryPoint->TotalSize;
 178     }
 179
 180     if (CorrectMicrocode) {
 181       LatestRevision = MicrocodeEntryPoint->UpdateRevision;
 182       MicrocodeInfo.MicrocodeData = (VOID *)((UINTN)MicrocodeEntryPoint + sizeof (EFI_CPU_MICROCODE_HEADER));
 183       MicrocodeInfo.MicrocodeSize = TotalSize;
 184       MicrocodeInfo.ProcessorId = RegEax;
 185     }
 186
 187     MicrocodeEntryPoint = (EFI_CPU_MICROCODE_HEADER *) (((UINTN) MicrocodeEntryPoint) + TotalSize);
 188   } while (((UINTN) MicrocodeEntryPoint < MicrocodeEnd));
 189
 190   if (LatestRevision > 0) {
 191     //
 192     // BIOS only authenticate updates that contain a numerically larger revision
 193     // than the currently loaded revision, where Current Signature < New Update
 194     // Revision. A processor with no loaded update is considered to have a
 195     // revision equal to zero.
 196     //
 197     if (LatestRevision > GetCurrentMicrocodeSignature ()) {
 198       AsmWriteMsr64 (
 199         EFI_MSR_IA32_BIOS_UPDT_TRIG,
 200         (UINT64) (UINTN) MicrocodeInfo.MicrocodeData
 201         );
 202       //
 203       // Get and verify new microcode signature
 204       //
 205       ASSERT (LatestRevision == GetCurrentMicrocodeSignature ());
 206       MicrocodeInfo.Load = TRUE;
 207     } else {
 208       MicrocodeInfo.Load = FALSE;
 209     }
 210   }
 211 }