/** @file
*
*  Copyright (c) 2011-2015, 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 "ArmGicDxe.h"
#include "GicV3/ArmGicV3Lib.h"

#define ARM_GIC_DEFAULT_PRIORITY  0x80

extern EFI_HARDWARE_INTERRUPT_PROTOCOL gHardwareInterruptV3Protocol;

STATIC UINTN mGicDistributorBase;
STATIC UINTN mGicRedistributorsBase;

/**
  Enable interrupt source Source.

  @param This     Instance pointer for this protocol
  @param Source   Hardware source of the interrupt

  @retval EFI_SUCCESS       Source interrupt enabled.
  @retval EFI_DEVICE_ERROR  Hardware could not be programmed.

**/
EFI_STATUS
EFIAPI
GicV3EnableInterruptSource (
  IN EFI_HARDWARE_INTERRUPT_PROTOCOL    *This,
  IN HARDWARE_INTERRUPT_SOURCE          Source
  )
{
  if (Source > mGicNumInterrupts) {
    ASSERT(FALSE);
    return EFI_UNSUPPORTED;
  }

  ArmGicEnableInterrupt (mGicDistributorBase, Source);

  return EFI_SUCCESS;
}

/**
  Disable interrupt source Source.

  @param This     Instance pointer for this protocol
  @param Source   Hardware source of the interrupt

  @retval EFI_SUCCESS       Source interrupt disabled.
  @retval EFI_DEVICE_ERROR  Hardware could not be programmed.

**/
EFI_STATUS
EFIAPI
GicV3DisableInterruptSource (
  IN EFI_HARDWARE_INTERRUPT_PROTOCOL    *This,
  IN HARDWARE_INTERRUPT_SOURCE          Source
  )
{
  if (Source > mGicNumInterrupts) {
    ASSERT(FALSE);
    return EFI_UNSUPPORTED;
  }

  ArmGicDisableInterrupt (mGicDistributorBase, Source);

  return EFI_SUCCESS;
}

/**
  Return current state of interrupt source Source.

  @param This     Instance pointer for this protocol
  @param Source   Hardware source of the interrupt
  @param InterruptState  TRUE: source enabled, FALSE: source disabled.

  @retval EFI_SUCCESS       InterruptState is valid
  @retval EFI_DEVICE_ERROR  InterruptState is not valid

**/
EFI_STATUS
EFIAPI
GicV3GetInterruptSourceState (
  IN EFI_HARDWARE_INTERRUPT_PROTOCOL    *This,
  IN HARDWARE_INTERRUPT_SOURCE          Source,
  IN BOOLEAN                            *InterruptState
  )
{
  if (Source > mGicNumInterrupts) {
    ASSERT(FALSE);
    return EFI_UNSUPPORTED;
  }

  *InterruptState = ArmGicIsInterruptEnabled (mGicDistributorBase, Source);

  return EFI_SUCCESS;
}

/**
  Signal to the hardware that the End Of Interrupt state
  has been reached.

  @param This     Instance pointer for this protocol
  @param Source   Hardware source of the interrupt

  @retval EFI_SUCCESS       Source interrupt EOI'ed.
  @retval EFI_DEVICE_ERROR  Hardware could not be programmed.

**/
EFI_STATUS
EFIAPI
GicV3EndOfInterrupt (
  IN EFI_HARDWARE_INTERRUPT_PROTOCOL    *This,
  IN HARDWARE_INTERRUPT_SOURCE          Source
  )
{
  if (Source > mGicNumInterrupts) {
    ASSERT(FALSE);
    return EFI_UNSUPPORTED;
  }

  ArmGicV3EndOfInterrupt (Source);
  return EFI_SUCCESS;
}

/**
  EFI_CPU_INTERRUPT_HANDLER that is called when a processor interrupt occurs.

  @param  InterruptType    Defines the type of interrupt or exception that
                           occurred on the processor.This parameter is processor architecture specific.
  @param  SystemContext    A pointer to the processor context when
                           the interrupt occurred on the processor.

  @return None

**/
VOID
EFIAPI
GicV3IrqInterruptHandler (
  IN EFI_EXCEPTION_TYPE           InterruptType,
  IN EFI_SYSTEM_CONTEXT           SystemContext
  )
{
  UINT32                      GicInterrupt;
  HARDWARE_INTERRUPT_HANDLER  InterruptHandler;

  GicInterrupt = ArmGicV3AcknowledgeInterrupt ();

  // Special Interrupts (ID1020-ID1023) have an Interrupt ID greater than the
  // number of interrupt (ie: Spurious interrupt).
  if ((GicInterrupt & ARM_GIC_ICCIAR_ACKINTID) >= mGicNumInterrupts) {
    // The special interrupt do not need to be acknowledge
    return;
  }

  InterruptHandler = gRegisteredInterruptHandlers[GicInterrupt];
  if (InterruptHandler != NULL) {
    // Call the registered interrupt handler.
    InterruptHandler (GicInterrupt, SystemContext);
  } else {
    DEBUG ((EFI_D_ERROR, "Spurious GIC interrupt: 0x%x\n", GicInterrupt));
  }

  GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, GicInterrupt);
}

//
// The protocol instance produced by this driver
//
EFI_HARDWARE_INTERRUPT_PROTOCOL gHardwareInterruptV3Protocol = {
  RegisterInterruptSource,
  GicV3EnableInterruptSource,
  GicV3DisableInterruptSource,
  GicV3GetInterruptSourceState,
  GicV3EndOfInterrupt
};

/**
  Shutdown our hardware

  DXE Core will disable interrupts and turn off the timer and disable interrupts
  after all the event handlers have run.

  @param[in]  Event   The Event that is being processed
  @param[in]  Context Event Context
**/
VOID
EFIAPI
GicV3ExitBootServicesEvent (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  UINTN    Index;

  // Acknowledge all pending interrupts
  for (Index = 0; Index < mGicNumInterrupts; Index++) {
    GicV3DisableInterruptSource (&gHardwareInterruptV3Protocol, Index);
  }

  for (Index = 0; Index < mGicNumInterrupts; Index++) {
    GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, Index);
  }

  // Disable Gic Interface
  ArmGicV3DisableInterruptInterface ();

  // Disable Gic Distributor
  ArmGicDisableDistributor (mGicDistributorBase);
}

/**
  Initialize the state information for the CPU Architectural Protocol

  @param  ImageHandle   of the loaded driver
  @param  SystemTable   Pointer to the System Table

  @retval EFI_SUCCESS           Protocol registered
  @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
  @retval EFI_DEVICE_ERROR      Hardware problems

**/
EFI_STATUS
GicV3DxeInitialize (
  IN EFI_HANDLE         ImageHandle,
  IN EFI_SYSTEM_TABLE   *SystemTable
  )
{
  EFI_STATUS              Status;
  UINTN                   Index;
  UINT32                  RegOffset;
  UINTN                   RegShift;
  UINT32                  CpuTarget;

  // Make sure the Interrupt Controller Protocol is not already installed in the system.
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gHardwareInterruptProtocolGuid);

  mGicDistributorBase    = PcdGet32 (PcdGicDistributorBase);
  mGicRedistributorsBase = PcdGet32 (PcdGicRedistributorsBase);
  mGicNumInterrupts      = ArmGicGetMaxNumInterrupts (mGicDistributorBase);

  for (Index = 0; Index < mGicNumInterrupts; Index++) {
    GicV3DisableInterruptSource (&gHardwareInterruptV3Protocol, Index);

    // Set Priority
    RegOffset = Index / 4;
    RegShift = (Index % 4) * 8;
    MmioAndThenOr32 (
      mGicDistributorBase + ARM_GIC_ICDIPR + (4 * RegOffset),
      ~(0xff << RegShift),
      ARM_GIC_DEFAULT_PRIORITY << RegShift
      );
  }

  //
  // Targets the interrupts to the Primary Cpu
  //

  // Only Primary CPU will run this code. We can identify our GIC CPU ID by reading
  // the GIC Distributor Target register. The 8 first GICD_ITARGETSRn are banked to each
  // connected CPU. These 8 registers hold the CPU targets fields for interrupts 0-31.
  // More Info in the GIC Specification about "Interrupt Processor Targets Registers"
  //
  // Read the first Interrupt Processor Targets Register (that corresponds to the 4
  // first SGIs)
  CpuTarget = MmioRead32 (mGicDistributorBase + ARM_GIC_ICDIPTR);

  // The CPU target is a bit field mapping each CPU to a GIC CPU Interface. This value
  // is 0 when we run on a uniprocessor platform.
  if (CpuTarget != 0) {
    // The 8 first Interrupt Processor Targets Registers are read-only
    for (Index = 8; Index < (mGicNumInterrupts / 4); Index++) {
      MmioWrite32 (mGicDistributorBase + ARM_GIC_ICDIPTR + (Index * 4), CpuTarget);
    }
  }

  // Set binary point reg to 0x7 (no preemption)
  ArmGicV3SetBinaryPointer (0x7);

  // Set priority mask reg to 0xff to allow all priorities through
  ArmGicV3SetPriorityMask (0xff);

  // Enable gic cpu interface
  ArmGicV3EnableInterruptInterface ();

  // Enable gic distributor
  ArmGicEnableDistributor (mGicDistributorBase);

  Status = InstallAndRegisterInterruptService (
          &gHardwareInterruptV3Protocol, GicV3IrqInterruptHandler, GicV3ExitBootServicesEvent);

  return Status;
}