/**@file

Copyright (c) 2006, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

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_CPU_IO_PROTOCOL mCpuIoProtocol;

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_IO_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;
  }

  Status = CpuIoCheckAddressRange (Width, Address, Count, Buffer, IA32_MAX_MEM_ADDRESS);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Do nothing for Nt32 version
  //
  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
CpuMemoryServiceWrite (
  IN EFI_CPU_IO_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;
  }

  Status = CpuIoCheckAddressRange (Width, Address, Count, Buffer, IA32_MAX_MEM_ADDRESS);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //
  // Do nothing for Nt32 version
  //
  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
CpuIoServiceRead (
  IN EFI_CPU_IO_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 >= 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_SUCCESS;
}

EFI_STATUS
EFIAPI
CpuIoServiceWrite (
  IN EFI_CPU_IO_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 >= 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_SUCCESS;
}


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 + (1 << Width) * Count > Limit) {
    return EFI_UNSUPPORTED;
  }

  AlignMask = (1 << Width) - 1;
  if ((UINTN) Buffer & AlignMask) {
    return EFI_UNSUPPORTED;
  }

  return EFI_SUCCESS;
}