Acpi.c

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#include "UefiLibInternal.h"
#include <IndustryStandard/Acpi.h>
#include <Guid/Acpi.h>
 
EFI_ACPI_COMMON_HEADER *
ScanTableInSDT (
  IN  EFI_ACPI_DESCRIPTION_HEADER  *Sdt,
  IN  UINTN                        TablePointerSize,
  IN  UINT32                       Signature,
  IN  EFI_ACPI_COMMON_HEADER       *PreviousTable  OPTIONAL,
  OUT BOOLEAN                      *PreviousTableLocated OPTIONAL
  )
{
  UINTN                   Index;
  UINTN                   EntryCount;
  UINT64                  EntryPtr;
  UINTN                   BasePtr;
  EFI_ACPI_COMMON_HEADER  *Table;
 
  if (PreviousTableLocated != NULL) {
    ASSERT (PreviousTable != NULL);
    *PreviousTableLocated = FALSE;
  } else {
    ASSERT (PreviousTable == NULL);
  }
 
  if (Sdt == NULL) {
    return NULL;
  }
 
  EntryCount = (Sdt->Length - sizeof (EFI_ACPI_DESCRIPTION_HEADER)) / TablePointerSize;
 
  BasePtr = (UINTN)(Sdt + 1);
  for (Index = 0; Index < EntryCount; Index++) {
    EntryPtr = 0;
    CopyMem (&EntryPtr, (VOID *)(BasePtr + Index * TablePointerSize), TablePointerSize);
    Table = (EFI_ACPI_COMMON_HEADER *)((UINTN)(EntryPtr));
    if ((Table != NULL) && (Table->Signature == Signature)) {
      if (PreviousTable != NULL) {
        if (Table == PreviousTable) {
          *PreviousTableLocated = TRUE;
        } else if (*PreviousTableLocated) {
          //
          // Return next table.
          //
          return Table;
        }
      } else {
        //
        // Return first table.
        //
        return Table;
      }
    }
  }
 
  return NULL;
}
 
EFI_ACPI_COMMON_HEADER *
LocateAcpiFacsFromFadt (
  IN EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE  *Fadt
  )
{
  EFI_ACPI_COMMON_HEADER  *Facs;
  UINT64                  Data64;
 
  if (Fadt == NULL) {
    return NULL;
  }
 
  if (Fadt->Header.Revision < EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_REVISION) {
    Facs = (EFI_ACPI_COMMON_HEADER *)(UINTN)Fadt->FirmwareCtrl;
  } else {
    CopyMem (&Data64, &Fadt->XFirmwareCtrl, sizeof (UINT64));
    if (Data64 != 0) {
      Facs = (EFI_ACPI_COMMON_HEADER *)(UINTN)Data64;
    } else {
      Facs = (EFI_ACPI_COMMON_HEADER *)(UINTN)Fadt->FirmwareCtrl;
    }
  }
 
  return Facs;
}
 
EFI_ACPI_COMMON_HEADER *
LocateAcpiDsdtFromFadt (
  IN EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE  *Fadt
  )
{
  EFI_ACPI_COMMON_HEADER  *Dsdt;
  UINT64                  Data64;
 
  if (Fadt == NULL) {
    return NULL;
  }
 
  if (Fadt->Header.Revision < EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_REVISION) {
    Dsdt = (EFI_ACPI_COMMON_HEADER *)(UINTN)Fadt->Dsdt;
  } else {
    CopyMem (&Data64, &Fadt->XDsdt, sizeof (UINT64));
    if (Data64 != 0) {
      Dsdt = (EFI_ACPI_COMMON_HEADER *)(UINTN)Data64;
    } else {
      Dsdt = (EFI_ACPI_COMMON_HEADER *)(UINTN)Fadt->Dsdt;
    }
  }
 
  return Dsdt;
}
 
EFI_ACPI_COMMON_HEADER *
LocateAcpiTableInAcpiConfigurationTable (
  IN  EFI_GUID                *AcpiGuid,
  IN  UINT32                  Signature,
  IN  EFI_ACPI_COMMON_HEADER  *PreviousTable  OPTIONAL,
  OUT BOOLEAN                 *PreviousTableLocated OPTIONAL
  )
{
  EFI_STATUS                                    Status;
  EFI_ACPI_COMMON_HEADER                        *Table;
  EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER  *Rsdp;
  EFI_ACPI_DESCRIPTION_HEADER                   *Rsdt;
  EFI_ACPI_DESCRIPTION_HEADER                   *Xsdt;
  EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE     *Fadt;
 
  if (PreviousTableLocated != NULL) {
    ASSERT (PreviousTable != NULL);
    *PreviousTableLocated = FALSE;
  } else {
    ASSERT (PreviousTable == NULL);
  }
 
  Rsdp = NULL;
  //
  // Get ACPI ConfigurationTable (RSD_PTR)
  //
  Status = EfiGetSystemConfigurationTable (AcpiGuid, (VOID **)&Rsdp);
  if (EFI_ERROR (Status) || (Rsdp == NULL)) {
    return NULL;
  }
 
  Table = NULL;
 
  //
  // Search XSDT
  //
  if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION) {
    Xsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN)Rsdp->XsdtAddress;
    if (Signature == EFI_ACPI_2_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) {
      ASSERT (PreviousTable == NULL);
      //
      // It is to locate DSDT,
      // need to locate FADT first.
      //
      Fadt = (EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE *)ScanTableInSDT (
                                                            Xsdt,
                                                            sizeof (UINT64),
                                                            EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE,
                                                            NULL,
                                                            NULL
                                                            );
 
      if (Fadt != NULL) {
        Table = LocateAcpiDsdtFromFadt (Fadt);
      } else {
        Table = NULL;
      }
    } else if (Signature == EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) {
      ASSERT (PreviousTable == NULL);
      //
      // It is to locate FACS,
      // need to locate FADT first.
      //
      Fadt = (EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE *)ScanTableInSDT (
                                                            Xsdt,
                                                            sizeof (UINT64),
                                                            EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE,
                                                            NULL,
                                                            NULL
                                                            );
 
      if (Fadt != NULL) {
        Table = LocateAcpiFacsFromFadt (Fadt);
      } else {
        Table = NULL;
      }
    } else {
      Table = ScanTableInSDT (
                Xsdt,
                sizeof (UINT64),
                Signature,
                PreviousTable,
                PreviousTableLocated
                );
    }
  }
 
  if (Table != NULL) {
    return Table;
  } else if ((PreviousTableLocated != NULL) &&
             *PreviousTableLocated)
  {
    //
    // PreviousTable could be located in XSDT,
    // but next table could not be located in XSDT.
    //
    return NULL;
  }
 
  //
  // Search RSDT
  //
  Rsdt = (EFI_ACPI_DESCRIPTION_HEADER *)(UINTN)Rsdp->RsdtAddress;
  if (Signature == EFI_ACPI_2_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) {
    ASSERT (PreviousTable == NULL);
    //
    // It is to locate DSDT,
    // need to locate FADT first.
    //
    Fadt = (EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE *)ScanTableInSDT (
                                                          Rsdt,
                                                          sizeof (UINT32),
                                                          EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE,
                                                          NULL,
                                                          NULL
                                                          );
 
    if (Fadt != NULL) {
      Table = LocateAcpiDsdtFromFadt (Fadt);
    } else {
      Table = NULL;
    }
  } else if (Signature == EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE) {
    ASSERT (PreviousTable == NULL);
    //
    // It is to locate FACS,
    // need to locate FADT first.
    //
    Fadt = (EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE *)ScanTableInSDT (
                                                          Rsdt,
                                                          sizeof (UINT32),
                                                          EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE,
                                                          NULL,
                                                          NULL
                                                          );
 
    if (Fadt != NULL) {
      Table = LocateAcpiFacsFromFadt (Fadt);
    } else {
      Table = NULL;
    }
  } else {
    Table = ScanTableInSDT (
              Rsdt,
              sizeof (UINT32),
              Signature,
              PreviousTable,
              PreviousTableLocated
              );
  }
 
  return Table;
}
 
EFI_ACPI_COMMON_HEADER *
EFIAPI
EfiLocateNextAcpiTable (
  IN UINT32                  Signature,
  IN EFI_ACPI_COMMON_HEADER  *PreviousTable OPTIONAL
  )
{
  EFI_ACPI_COMMON_HEADER  *Table;
  BOOLEAN                 TempPreviousTableLocated;
  BOOLEAN                 *PreviousTableLocated;
 
  if (PreviousTable != NULL) {
    if (PreviousTable->Signature != Signature) {
      //
      // PreviousTable->Signature is not same with Signature.
      //
      return NULL;
    } else if ((Signature == EFI_ACPI_2_0_FIXED_ACPI_DESCRIPTION_TABLE_SIGNATURE) ||
               (Signature == EFI_ACPI_2_0_DIFFERENTIATED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) ||
               (Signature == EFI_ACPI_2_0_FIRMWARE_ACPI_CONTROL_STRUCTURE_SIGNATURE))
    {
      //
      // There is only one FADT/DSDT/FACS table,
      // so don't try to locate next one.
      //
      return NULL;
    }
 
    PreviousTableLocated  = &TempPreviousTableLocated;
    *PreviousTableLocated = FALSE;
  } else {
    PreviousTableLocated = NULL;
  }
 
  Table = LocateAcpiTableInAcpiConfigurationTable (
            &gEfiAcpi20TableGuid,
            Signature,
            PreviousTable,
            PreviousTableLocated
            );
  if (Table != NULL) {
    return Table;
  } else if ((PreviousTableLocated != NULL) &&
             *PreviousTableLocated)
  {
    //
    // PreviousTable could be located in gEfiAcpi20TableGuid system
    // configuration table, but next table could not be located in
    // gEfiAcpi20TableGuid system configuration table.
    //
    return NULL;
  }
 
  return LocateAcpiTableInAcpiConfigurationTable (
           &gEfiAcpi10TableGuid,
           Signature,
           PreviousTable,
           PreviousTableLocated
           );
}
 
EFI_ACPI_COMMON_HEADER *
EFIAPI
EfiLocateFirstAcpiTable (
  IN UINT32  Signature
  )
{
  return EfiLocateNextAcpiTable (Signature, NULL);
}