/**@file

Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

Module Name:

  CpuIo.c

Abstract:

  This is the code that publishes the CPU I/O Protocol.
  The intent herein is to have a single I/O service that can load
  as early as possible, extend into runtime, and be layered upon by 
  the implementations of architectural protocols and the PCI Root
  Bridge I/O Protocol.

**/

#include <CpuDriver.h>

#define IA32_MAX_IO_ADDRESS   0xFFFF
#define IA32_MAX_MEM_ADDRESS  0xFFFFFFFF

EFI_STATUS
CpuIoCheckAddressRange (
  IN  EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN  UINT64                            Address,
  IN  UINTN                             Count,
  IN  VOID                              *Buffer,
  IN  UINT64                            Limit
  );

EFI_STATUS
EFIAPI
CpuMemoryServiceRead (
  IN  EFI_CPU_IO2_PROTOCOL              *This,
  IN  EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN  UINT64                            Address,
  IN  UINTN                             Count,
  IN  OUT VOID                          *Buffer
  )
/*++

Routine Description:

  Perform the Memory Access Read service for the CPU I/O Protocol

Arguments:

  Pointer to an instance of the CPU I/O Protocol
  Width of the Memory Access
  Address of the Memory access
  Count of the number of accesses to perform
  Pointer to the buffer to read or write from memory

Returns:

  Status

  EFI_SUCCESS             - The data was read from or written to the EFI 
                            System.
  EFI_INVALID_PARAMETER   - Width is invalid for this EFI System.
  EFI_INVALID_PARAMETER   - Buffer is NULL.
  EFI_UNSUPPORTED         - The Buffer is not aligned for the given Width.
  EFI_UNSUPPORTED         - The address range specified by Address, Width, 
                            and Count is not valid for this EFI System.

--*/
// TODO:    This - add argument and description to function comment
{
  EFI_STATUS  Status;

  if (!Buffer) {
    return EFI_INVALID_PARAMETER;
  }

  if ((Width < 0) || (Width >= EfiCpuIoWidthMaximum)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = CpuIoCheckAddressRange (Width, Address, Count, Buffer, IA32_MAX_MEM_ADDRESS);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Do nothing for Nt32 version
  //
  return EFI_UNSUPPORTED;
}

EFI_STATUS
EFIAPI
CpuMemoryServiceWrite (
  IN EFI_CPU_IO2_PROTOCOL               *This,
  IN  EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN  UINT64                            Address,
  IN  UINTN                             Count,
  IN  OUT VOID                          *Buffer
  )
/*++

Routine Description:

  Perform the Memory Access Read service for the CPU I/O Protocol

Arguments:

  Pointer to an instance of the CPU I/O Protocol
  Width of the Memory Access
  Address of the Memory access
  Count of the number of accesses to perform
  Pointer to the buffer to read or write from memory

Returns:

  Status

  EFI_SUCCESS             - The data was read from or written to the EFI System.
  EFI_INVALID_PARAMETER   - Width is invalid for this EFI System.
  EFI_INVALID_PARAMETER   - Buffer is NULL.
  EFI_UNSUPPORTED         - The Buffer is not aligned for the given Width.
  EFI_UNSUPPORTED         - The address range specified by Address, Width, and 
                            Count is not valid for this EFI System.

--*/
// TODO:    This - add argument and description to function comment
{
  EFI_STATUS  Status;

  if (!Buffer) {
    return EFI_INVALID_PARAMETER;
  }

  if ((Width < 0) || (Width >= EfiCpuIoWidthMaximum)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = CpuIoCheckAddressRange (Width, Address, Count, Buffer, IA32_MAX_MEM_ADDRESS);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Do nothing for Nt32 version
  //
  return EFI_UNSUPPORTED;
}

EFI_STATUS
EFIAPI
CpuIoServiceRead (
  IN EFI_CPU_IO2_PROTOCOL               *This,
  IN  EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN  UINT64                            UserAddress,
  IN  UINTN                             Count,
  IN  OUT VOID                          *UserBuffer
  )
/*++

Routine Description:
  
  This is the service that implements the I/O read

Arguments:

  Pointer to an instance of the CPU I/O Protocol
  Width of the Memory Access
  Address of the I/O access
  Count of the number of accesses to perform
  Pointer to the buffer to read or write from I/O space

Returns:

  Status
  EFI_SUCCESS             - The data was read from or written to the EFI System.
  EFI_INVALID_PARAMETER   - Width is invalid for this EFI System.
  EFI_INVALID_PARAMETER   - Buffer is NULL.
  EFI_UNSUPPORTED         - The Buffer is not aligned for the given Width.
  EFI_UNSUPPORTED         - The address range specified by Address, Width, and 
                            Count is not valid for this EFI System.
--*/
// TODO:    This - add argument and description to function comment
// TODO:    UserAddress - add argument and description to function comment
// TODO:    UserBuffer - add argument and description to function comment
{
  UINTN       Address;
  EFI_STATUS  Status;

  if (!UserBuffer) {
    return EFI_INVALID_PARAMETER;
  }

  Address = (UINTN) UserAddress;

  if ((Width < 0) || (Width >= EfiCpuIoWidthMaximum)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = CpuIoCheckAddressRange (Width, Address, Count, UserBuffer, IA32_MAX_IO_ADDRESS);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Do nothing for Nt32 version
  //
  return EFI_UNSUPPORTED;
}

EFI_STATUS
EFIAPI
CpuIoServiceWrite (
  IN EFI_CPU_IO2_PROTOCOL               *This,
  IN  EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN  UINT64                            UserAddress,
  IN  UINTN                             Count,
  IN  OUT VOID                          *UserBuffer
  )
/*++

Routine Description:

  
  This is the service that implements the I/O Write

Arguments:

  Pointer to an instance of the CPU I/O Protocol
  Width of the Memory Access
  Address of the I/O access
  Count of the number of accesses to perform
  Pointer to the buffer to read or write from I/O space

Returns:

  Status

  Status
  EFI_SUCCESS             - The data was read from or written to the EFI System.
  EFI_INVALID_PARAMETER   - Width is invalid for this EFI System.
  EFI_INVALID_PARAMETER   - Buffer is NULL.
  EFI_UNSUPPORTED         - The Buffer is not aligned for the given Width.
  EFI_UNSUPPORTED         - The address range specified by Address, Width, and 
                            Count is not valid for this EFI System.

--*/
// TODO:    This - add argument and description to function comment
// TODO:    UserAddress - add argument and description to function comment
// TODO:    UserBuffer - add argument and description to function comment
{
  UINTN       Address;
  EFI_STATUS  Status;

  if (!UserBuffer) {
    return EFI_INVALID_PARAMETER;
  }

  Address = (UINTN) UserAddress;

  if ((Width < 0) || (Width >= EfiCpuIoWidthMaximum)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = CpuIoCheckAddressRange (Width, Address, Count, UserBuffer, IA32_MAX_IO_ADDRESS);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Do nothing for Nt32 version
  //
  return EFI_UNSUPPORTED;
}


EFI_STATUS
CpuIoCheckAddressRange (
  IN  EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN  UINT64                            Address,
  IN  UINTN                             Count,
  IN  VOID                              *Buffer,
  IN  UINT64                            Limit
  )
/*++

Routine Description:

  TODO: Add function description

Arguments:

  Width   - TODO: add argument description
  Address - TODO: add argument description
  Count   - TODO: add argument description
  Buffer  - TODO: add argument description
  Limit   - TODO: add argument description

Returns:

  EFI_UNSUPPORTED - TODO: Add description for return value
  EFI_UNSUPPORTED - TODO: Add description for return value
  EFI_UNSUPPORTED - TODO: Add description for return value
  EFI_SUCCESS - TODO: Add description for return value

--*/
{
  UINTN AlignMask;

  if (Address > Limit) {
    return EFI_UNSUPPORTED;
  }

  //
  // For FiFo type, the target address won't increase during the access, so treat count as 1
  //
  if (Width >= EfiCpuIoWidthFifoUint8 && Width <= EfiCpuIoWidthFifoUint64) {
    Count = 1;
  }

  Width = (EFI_CPU_IO_PROTOCOL_WIDTH)(Width & 0x03);
  if (Address - 1 + ((UINTN)1 << Width) * Count > Limit) {
    return EFI_UNSUPPORTED;
  }

  AlignMask = ((UINTN)1 << Width) - 1;
  if ((UINTN) Buffer & AlignMask) {
    return EFI_UNSUPPORTED;
  }

  return EFI_SUCCESS;
}