/** @file
*
*  Copyright (c) 2011-2012, 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 <Base.h>
#include <Library/ArmLib.h>
#include <Library/DebugLib.h>
#include <Library/IoLib.h>
#include <Library/ArmGicLib.h>

/*
 * This function configures the all interrupts to be Non-secure.
 *
 */
VOID
EFIAPI
ArmGicSetupNonSecure (
  IN  UINTN         MpId,
  IN  INTN          GicDistributorBase,
  IN  INTN          GicInterruptInterfaceBase
  )
{
  UINTN InterruptId;
  UINTN CachedPriorityMask;
  UINTN Index;

  CachedPriorityMask = MmioRead32 (GicInterruptInterfaceBase + ARM_GIC_ICCPMR);

  // Set priority Mask so that no interrupts get through to CPU
  MmioWrite32 (GicInterruptInterfaceBase + ARM_GIC_ICCPMR, 0);

  // Check if there are any pending interrupts
  //TODO: could be extended to take Peripheral interrupts into consideration, but at the moment only SGI's are taken into consideration.
  while(0 != (MmioRead32 (GicDistributorBase + ARM_GIC_ICDICPR) & 0xF)) {
    // Some of the SGI's are still pending, read Ack register and send End of Interrupt Signal
    InterruptId = MmioRead32 (GicInterruptInterfaceBase + ARM_GIC_ICCIAR);

    // Write to End of interrupt signal
    MmioWrite32 (GicInterruptInterfaceBase + ARM_GIC_ICCEIOR, InterruptId);
  }

  // Only the primary core should set the Non Secure bit to the SPIs (Shared Peripheral Interrupt).
  if (IS_PRIMARY_CORE(MpId)) {
    // Ensure all GIC interrupts are Non-Secure
    for (Index = 0; Index < (ArmGicGetMaxNumInterrupts (GicDistributorBase) / 32); Index++) {
      MmioWrite32 (GicDistributorBase + ARM_GIC_ICDISR + (Index * 4), 0xffffffff);
    }
  } else {
    // The secondary cores only set the Non Secure bit to their banked PPIs
    MmioWrite32 (GicDistributorBase + ARM_GIC_ICDISR, 0xffffffff);
  }

  // Ensure all interrupts can get through the priority mask
  MmioWrite32 (GicInterruptInterfaceBase + ARM_GIC_ICCPMR, CachedPriorityMask);
}

/*
 * This function configures the interrupts set by the mask to be secure.
 *
 */
VOID
EFIAPI
ArmGicSetSecureInterrupts (
  IN  UINTN         GicDistributorBase,
  IN  UINTN*        GicSecureInterruptMask,
  IN  UINTN         GicSecureInterruptMaskSize
  )
{
  UINTN  Index;
  UINT32 InterruptStatus;

  // We must not have more interrupts defined by the mask than the number of available interrupts
  ASSERT(GicSecureInterruptMaskSize <= (ArmGicGetMaxNumInterrupts (GicDistributorBase) / 32));

  // Set all the interrupts defined by the mask as Secure
  for (Index = 0; Index < GicSecureInterruptMaskSize; Index++) {
    InterruptStatus = MmioRead32 (GicDistributorBase + ARM_GIC_ICDISR + (Index * 4));
    MmioWrite32 (GicDistributorBase + ARM_GIC_ICDISR + (Index * 4), InterruptStatus & (~GicSecureInterruptMask[Index]));
  }
}

VOID
EFIAPI
ArmGicEnableInterruptInterface (
  IN  INTN          GicInterruptInterfaceBase
  )
{
  // Set Priority Mask to allow interrupts
  MmioWrite32 (GicInterruptInterfaceBase + ARM_GIC_ICCPMR, 0x000000FF);

  // Enable CPU interface in Secure world
  // Enable CPU inteface in Non-secure World
  // Signal Secure Interrupts to CPU using FIQ line *
  MmioWrite32 (GicInterruptInterfaceBase + ARM_GIC_ICCICR,
      ARM_GIC_ICCICR_ENABLE_SECURE |
      ARM_GIC_ICCICR_ENABLE_NS |
      ARM_GIC_ICCICR_SIGNAL_SECURE_TO_FIQ);
}

VOID
EFIAPI
ArmGicEnableDistributor (
  IN  INTN          GicDistributorBase
  )
{
  // Turn on the GIC distributor
  MmioWrite32 (GicDistributorBase + ARM_GIC_ICDDCR, 1);
}