system76-edk2/MdePkg/Library/BaseIoLibIntrinsic/IoLib.c

/** @file
  Common I/O Library routines.

  Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "BaseIoLibIntrinsicInternal.h"
#include "IoLibTdx.h"

/**
  Reads a 64-bit I/O port.

  Reads the 64-bit I/O port specified by Port. The 64-bit read value is returned.
  This function must guarantee that all I/O read and write operations are
  serialized.

  If 64-bit I/O port operations are not supported, then ASSERT().
  If Port is not aligned on a 64-bit boundary, then ASSERT().

  @param  Port  The I/O port to read.

  @return The value read.

**/
UINT64
EFIAPI
IoRead64 (
  IN      UINTN  Port
  )
{
  ASSERT (FALSE);
  return 0;
}

/**
  Writes a 64-bit I/O port.

  Writes the 64-bit I/O port specified by Port with the value specified by Value
  and returns Value. This function must guarantee that all I/O read and write
  operations are serialized.

  If 64-bit I/O port operations are not supported, then ASSERT().
  If Port is not aligned on a 64-bit boundary, then ASSERT().

  @param  Port  The I/O port to write.
  @param  Value The value to write to the I/O port.

  @return The value written the I/O port.

**/
UINT64
EFIAPI
IoWrite64 (
  IN      UINTN   Port,
  IN      UINT64  Value
  )
{
  ASSERT (FALSE);
  return 0;
}

/**
  Reads an 8-bit MMIO register.

  Reads the 8-bit MMIO register specified by Address. The 8-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 8-bit MMIO register operations are not supported, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to read MMIO registers.

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT8
EFIAPI
MmioRead8 (
  IN      UINTN  Address
  )
{
  UINT8    Value;
  BOOLEAN  Flag;

  Flag = FilterBeforeMmIoRead (FilterWidth8, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      Value = TdMmioRead8 (Address);
    } else {
      Value = *(volatile UINT8 *)Address;
    }

    MemoryFence ();
  }

  FilterAfterMmIoRead (FilterWidth8, Address, &Value);

  return Value;
}

/**
  Writes an 8-bit MMIO register.

  Writes the 8-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 8-bit MMIO register operations are not supported, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to write MMIO registers.

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

  @return Value.

**/
UINT8
EFIAPI
MmioWrite8 (
  IN      UINTN  Address,
  IN      UINT8  Value
  )
{
  BOOLEAN  Flag;

  Flag = FilterBeforeMmIoWrite (FilterWidth8, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      TdMmioWrite8 (Address, Value);
    } else {
      *(volatile UINT8 *)Address = Value;
    }

    MemoryFence ();
  }

  FilterAfterMmIoWrite (FilterWidth8, Address, &Value);

  return Value;
}

/**
  Reads a 16-bit MMIO register.

  Reads the 16-bit MMIO register specified by Address. The 16-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 16-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 16-bit boundary, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to read MMIO registers.

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT16
EFIAPI
MmioRead16 (
  IN      UINTN  Address
  )
{
  UINT16   Value;
  BOOLEAN  Flag;

  ASSERT ((Address & 1) == 0);
  Flag = FilterBeforeMmIoRead (FilterWidth16, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      Value = TdMmioRead16 (Address);
    } else {
      Value = *(volatile UINT16 *)Address;
    }

    MemoryFence ();
  }

  FilterAfterMmIoRead (FilterWidth16, Address, &Value);

  return Value;
}

/**
  Writes a 16-bit MMIO register.

  Writes the 16-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 16-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 16-bit boundary, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to write MMIO registers.

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

  @return Value.

**/
UINT16
EFIAPI
MmioWrite16 (
  IN      UINTN   Address,
  IN      UINT16  Value
  )
{
  BOOLEAN  Flag;

  ASSERT ((Address & 1) == 0);

  Flag = FilterBeforeMmIoWrite (FilterWidth16, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      TdMmioWrite16 (Address, Value);
    } else {
      *(volatile UINT16 *)Address = Value;
    }

    MemoryFence ();
  }

  FilterAfterMmIoWrite (FilterWidth16, Address, &Value);

  return Value;
}

/**
  Reads a 32-bit MMIO register.

  Reads the 32-bit MMIO register specified by Address. The 32-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 32-bit boundary, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to read MMIO registers.

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT32
EFIAPI
MmioRead32 (
  IN      UINTN  Address
  )
{
  UINT32   Value;
  BOOLEAN  Flag;

  ASSERT ((Address & 3) == 0);

  Flag = FilterBeforeMmIoRead (FilterWidth32, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      Value = TdMmioRead32 (Address);
    } else {
      Value = *(volatile UINT32 *)Address;
    }

    MemoryFence ();
  }

  FilterAfterMmIoRead (FilterWidth32, Address, &Value);

  return Value;
}

/**
  Writes a 32-bit MMIO register.

  Writes the 32-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 32-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 32-bit boundary, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to write MMIO registers.

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

  @return Value.

**/
UINT32
EFIAPI
MmioWrite32 (
  IN      UINTN   Address,
  IN      UINT32  Value
  )
{
  BOOLEAN  Flag;

  ASSERT ((Address & 3) == 0);

  Flag = FilterBeforeMmIoWrite (FilterWidth32, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      TdMmioWrite32 (Address, Value);
    } else {
      *(volatile UINT32 *)Address = Value;
    }

    MemoryFence ();
  }

  FilterAfterMmIoWrite (FilterWidth32, Address, &Value);

  return Value;
}

/**
  Reads a 64-bit MMIO register.

  Reads the 64-bit MMIO register specified by Address. The 64-bit read value is
  returned. This function must guarantee that all MMIO read and write
  operations are serialized.

  If 64-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 64-bit boundary, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to read MMIO registers.

  @param  Address The MMIO register to read.

  @return The value read.

**/
UINT64
EFIAPI
MmioRead64 (
  IN      UINTN  Address
  )
{
  UINT64   Value;
  BOOLEAN  Flag;

  ASSERT ((Address & 7) == 0);

  Flag = FilterBeforeMmIoRead (FilterWidth64, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      Value = TdMmioRead64 (Address);
    } else {
      Value = *(volatile UINT64 *)Address;
    }

    MemoryFence ();
  }

  FilterAfterMmIoRead (FilterWidth64, Address, &Value);

  return Value;
}

/**
  Writes a 64-bit MMIO register.

  Writes the 64-bit MMIO register specified by Address with the value specified
  by Value and returns Value. This function must guarantee that all MMIO read
  and write operations are serialized.

  If 64-bit MMIO register operations are not supported, then ASSERT().
  If Address is not aligned on a 64-bit boundary, then ASSERT().

  For Td guest TDVMCALL_MMIO is invoked to write MMIO registers.

  @param  Address The MMIO register to write.
  @param  Value   The value to write to the MMIO register.

**/
UINT64
EFIAPI
MmioWrite64 (
  IN      UINTN   Address,
  IN      UINT64  Value
  )
{
  BOOLEAN  Flag;

  ASSERT ((Address & 7) == 0);

  Flag = FilterBeforeMmIoWrite (FilterWidth64, Address, &Value);
  if (Flag) {
    MemoryFence ();

    if (IsTdxGuest ()) {
      TdMmioWrite64 (Address, Value);
    } else {
      *(volatile UINT64 *)Address = Value;
    }

    MemoryFence ();
  }

  FilterAfterMmIoWrite (FilterWidth64, Address, &Value);

  return Value;
}