UefiCpuPkg/Library/MpInitLib/X64/CreatePageTable.c

   1 /** @file
   2   Function to create page talbe.
   3   Only create page table for x64, and leave the CreatePageTable empty for Ia32.
   4   Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6 **/
   7 #include <Library/CpuPageTableLib.h>
   8 #include <Library/MemoryAllocationLib.h>
   9 #include <Base.h>
  10 #include <Library/BaseMemoryLib.h>
  11 #include <Library/DebugLib.h>
  12 #include <Library/BaseLib.h>
  13
  14 /**
  15   Create 1:1 mapping page table in reserved memory to map the specified address range.
  16   @param[in]      LinearAddress  The start of the linear address range.
  17   @param[in]      Length         The length of the linear address range.
  18   @return The page table to be created.
  19 **/
  20 UINTN
  21 CreatePageTable (
  22   IN UINTN  Address,
  23   IN UINTN  Length
  24   )
  25 {
  26   EFI_STATUS   Status;
  27   VOID         *PageTableBuffer;
  28   UINTN        PageTableBufferSize;
  29   UINTN        PageTable;
  30   PAGING_MODE  PagingMode;
  31   IA32_CR4     Cr4;
  32
  33   IA32_MAP_ATTRIBUTE  MapAttribute;
  34   IA32_MAP_ATTRIBUTE  MapMask;
  35
  36   MapAttribute.Uint64         = Address;
  37   MapAttribute.Bits.Present   = 1;
  38   MapAttribute.Bits.ReadWrite = 1;
  39
  40   MapMask.Bits.PageTableBaseAddress = 1;
  41   MapMask.Bits.Present              = 1;
  42   MapMask.Bits.ReadWrite            = 1;
  43
  44   PageTable           = 0;
  45   PageTableBufferSize = 0;
  46
  47   Cr4.UintN = AsmReadCr4 ();
  48
  49   if (Cr4.Bits.LA57 == 1) {
  50     PagingMode = Paging5Level;
  51   } else {
  52     PagingMode = Paging4Level;
  53   }
  54
  55   Status = PageTableMap (
  56              &PageTable,
  57              PagingMode,
  58              NULL,
  59              &PageTableBufferSize,
  60              Address,
  61              Length,
  62              &MapAttribute,
  63              &MapMask
  64              );
  65   ASSERT (Status == EFI_BUFFER_TOO_SMALL);
  66   DEBUG ((DEBUG_INFO, "AP Page Table Buffer Size = %x\n", PageTableBufferSize));
  67
  68   PageTableBuffer = AllocateReservedPages (EFI_SIZE_TO_PAGES (PageTableBufferSize));
  69   ASSERT (PageTableBuffer != NULL);
  70   Status = PageTableMap (
  71              &PageTable,
  72              PagingMode,
  73              PageTableBuffer,
  74              &PageTableBufferSize,
  75              Address,
  76              Length,
  77              &MapAttribute,
  78              &MapMask
  79              );
  80   ASSERT_EFI_ERROR (Status);
  81   return PageTable;
  82 }