/** @file

  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
  Copyright (c) 2011, ARM Limited. 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.

**/

#include "CpuDxe.h"

#include <Guid/IdleLoopEvent.h>

BOOLEAN mInterruptState   = FALSE;


/**
  This function flushes the range of addresses from Start to Start+Length 
  from the processor's data cache. If Start is not aligned to a cache line 
  boundary, then the bytes before Start to the preceding cache line boundary 
  are also flushed. If Start+Length is not aligned to a cache line boundary, 
  then the bytes past Start+Length to the end of the next cache line boundary 
  are also flushed. The FlushType of EfiCpuFlushTypeWriteBackInvalidate must be 
  supported. If the data cache is fully coherent with all DMA operations, then 
  this function can just return EFI_SUCCESS. If the processor does not support 
  flushing a range of the data cache, then the entire data cache can be flushed.

  @param  This             The EFI_CPU_ARCH_PROTOCOL instance.
  @param  Start            The beginning physical address to flush from the processor's data
                           cache.
  @param  Length           The number of bytes to flush from the processor's data cache. This
                           function may flush more bytes than Length specifies depending upon
                           the granularity of the flush operation that the processor supports.
  @param  FlushType        Specifies the type of flush operation to perform.

  @retval EFI_SUCCESS           The address range from Start to Start+Length was flushed from
                                the processor's data cache.
  @retval EFI_UNSUPPORTEDT      The processor does not support the cache flush type specified
                                by FlushType.
  @retval EFI_DEVICE_ERROR      The address range from Start to Start+Length could not be flushed
                                from the processor's data cache.

**/
EFI_STATUS
EFIAPI
CpuFlushCpuDataCache (
  IN EFI_CPU_ARCH_PROTOCOL           *This,
  IN EFI_PHYSICAL_ADDRESS            Start,
  IN UINT64                          Length,
  IN EFI_CPU_FLUSH_TYPE              FlushType
  )
{

  switch (FlushType) {
    case EfiCpuFlushTypeWriteBack:
      WriteBackDataCacheRange ((VOID *)(UINTN)Start, (UINTN)Length);
      break;
    case EfiCpuFlushTypeInvalidate:
      InvalidateDataCacheRange ((VOID *)(UINTN)Start, (UINTN)Length);
      break;
    case EfiCpuFlushTypeWriteBackInvalidate:
      WriteBackInvalidateDataCacheRange ((VOID *)(UINTN)Start, (UINTN)Length);
      break;
    default:
      return EFI_INVALID_PARAMETER;
  }
  
  return EFI_SUCCESS;
}


/**
  This function enables interrupt processing by the processor. 

  @param  This             The EFI_CPU_ARCH_PROTOCOL instance.

  @retval EFI_SUCCESS           Interrupts are enabled on the processor.
  @retval EFI_DEVICE_ERROR      Interrupts could not be enabled on the processor.

**/
EFI_STATUS
EFIAPI
CpuEnableInterrupt (
  IN EFI_CPU_ARCH_PROTOCOL          *This
  )
{
  ArmEnableInterrupts ();

  mInterruptState  = TRUE;
  return EFI_SUCCESS;
}


/**
  This function disables interrupt processing by the processor.

  @param  This             The EFI_CPU_ARCH_PROTOCOL instance.

  @retval EFI_SUCCESS           Interrupts are disabled on the processor.
  @retval EFI_DEVICE_ERROR      Interrupts could not be disabled on the processor.

**/
EFI_STATUS
EFIAPI
CpuDisableInterrupt (
  IN EFI_CPU_ARCH_PROTOCOL          *This
  )
{
  ArmDisableInterrupts ();

  mInterruptState = FALSE;
  return EFI_SUCCESS;
}


/**
  This function retrieves the processor's current interrupt state a returns it in 
  State. If interrupts are currently enabled, then TRUE is returned. If interrupts 
  are currently disabled, then FALSE is returned.

  @param  This             The EFI_CPU_ARCH_PROTOCOL instance.
  @param  State            A pointer to the processor's current interrupt state. Set to TRUE if
                           interrupts are enabled and FALSE if interrupts are disabled.

  @retval EFI_SUCCESS           The processor's current interrupt state was returned in State.
  @retval EFI_INVALID_PARAMETER State is NULL.

**/
EFI_STATUS
EFIAPI
CpuGetInterruptState (
  IN  EFI_CPU_ARCH_PROTOCOL         *This,
  OUT BOOLEAN                       *State
  )
{
  if (State == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  *State = mInterruptState;
  return EFI_SUCCESS;
}


/**
  This function generates an INIT on the processor. If this function succeeds, then the
  processor will be reset, and control will not be returned to the caller. If InitType is 
  not supported by this processor, or the processor cannot programmatically generate an 
  INIT without help from external hardware, then EFI_UNSUPPORTED is returned. If an error 
  occurs attempting to generate an INIT, then EFI_DEVICE_ERROR is returned.

  @param  This             The EFI_CPU_ARCH_PROTOCOL instance.
  @param  InitType         The type of processor INIT to perform.

  @retval EFI_SUCCESS           The processor INIT was performed. This return code should never be seen.
  @retval EFI_UNSUPPORTED       The processor INIT operation specified by InitType is not supported
                                by this processor.
  @retval EFI_DEVICE_ERROR      The processor INIT failed.

**/
EFI_STATUS
EFIAPI
CpuInit (
  IN EFI_CPU_ARCH_PROTOCOL           *This,
  IN EFI_CPU_INIT_TYPE               InitType
  )
{
  return EFI_UNSUPPORTED;
}

EFI_STATUS
EFIAPI
CpuRegisterInterruptHandler (
  IN EFI_CPU_ARCH_PROTOCOL          *This,
  IN EFI_EXCEPTION_TYPE             InterruptType,
  IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
  )
{
  return RegisterInterruptHandler (InterruptType, InterruptHandler);
}

EFI_STATUS
EFIAPI
CpuGetTimerValue (
  IN  EFI_CPU_ARCH_PROTOCOL          *This,
  IN  UINT32                         TimerIndex,
  OUT UINT64                         *TimerValue,
  OUT UINT64                         *TimerPeriod   OPTIONAL
  )
{
  return EFI_UNSUPPORTED;
}

/**
  Callback function for idle events.
 
  @param  Event                 Event whose notification function is being invoked.
  @param  Context               The pointer to the notification function's context,
                                which is implementation-dependent.

**/
VOID
EFIAPI
IdleLoopEventCallback (
  IN EFI_EVENT                Event,
  IN VOID                     *Context
  )
{
  CpuSleep ();
}

//
// Globals used to initialize the protocol
//
EFI_HANDLE            mCpuHandle = NULL;
EFI_CPU_ARCH_PROTOCOL mCpu = {
  CpuFlushCpuDataCache,
  CpuEnableInterrupt,
  CpuDisableInterrupt,
  CpuGetInterruptState,
  CpuInit,
  CpuRegisterInterruptHandler,
  CpuGetTimerValue,
  CpuSetMemoryAttributes,
  0,          // NumberOfTimers
  4,          // DmaBufferAlignment
};

EFI_STATUS
CpuDxeInitialize (
  IN EFI_HANDLE         ImageHandle,
  IN EFI_SYSTEM_TABLE   *SystemTable
  )
{
  EFI_STATUS  Status;
  EFI_EVENT    IdleLoopEvent;

  InitializeExceptions (&mCpu);  
  
  Status = gBS->InstallMultipleProtocolInterfaces (
                &mCpuHandle, 
                &gEfiCpuArchProtocolGuid,           &mCpu, 
                &gVirtualUncachedPagesProtocolGuid, &gVirtualUncachedPages,
                NULL
                );
  
  //
  // Make sure GCD and MMU settings match. This API calls gDS->SetMemorySpaceAttributes ()
  // and that calls EFI_CPU_ARCH_PROTOCOL.SetMemoryAttributes, so this code needs to go
  // after the protocol is installed
  //
  SyncCacheConfig (&mCpu);
  
  //
  // Setup a callback for idle events
  //
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  IdleLoopEventCallback,
                  NULL,
                  &gIdleLoopEventGuid,
                  &IdleLoopEvent
                  );
  ASSERT_EFI_ERROR (Status);

  return Status;
}