/** @file
*
*  Copyright (c) 2011-2023, Arm Limited. All rights reserved.
*
*  SPDX-License-Identifier: BSD-2-Clause-Patent
*
**/

#include <Library/ArmGicLib.h>

#include "ArmGicDxe.h"

#define ARM_GIC_DEFAULT_PRIORITY  0x80

// In GICv3, there are 2 x 64KB frames:
// Redistributor control frame + SGI Control & Generation frame
#define GIC_V3_REDISTRIBUTOR_GRANULARITY  (ARM_GICR_CTLR_FRAME_SIZE           \
                                           + ARM_GICR_SGI_PPI_FRAME_SIZE)

// In GICv4, there are 2 additional 64KB frames:
// VLPI frame + Reserved page frame
#define GIC_V4_REDISTRIBUTOR_GRANULARITY  (GIC_V3_REDISTRIBUTOR_GRANULARITY   \
                                           + ARM_GICR_SGI_VLPI_FRAME_SIZE     \
                                           + ARM_GICR_SGI_RESERVED_FRAME_SIZE)

#define GICD_V3_SIZE  SIZE_64KB

#define ISENABLER_ADDRESS(base, offset)  ((base) +\
          ARM_GICR_CTLR_FRAME_SIZE + ARM_GICR_ISENABLER + 4 * (offset))

#define ICENABLER_ADDRESS(base, offset)  ((base) +\
          ARM_GICR_CTLR_FRAME_SIZE + ARM_GICR_ICENABLER + 4 * (offset))

#define IPRIORITY_ADDRESS(base, offset)  ((base) +\
          ARM_GICR_CTLR_FRAME_SIZE + ARM_GIC_ICDIPR + 4 * (offset))

extern EFI_HARDWARE_INTERRUPT_PROTOCOL   gHardwareInterruptV3Protocol;
extern EFI_HARDWARE_INTERRUPT2_PROTOCOL  gHardwareInterrupt2V3Protocol;

STATIC UINTN  mGicDistributorBase;
STATIC UINTN  mGicRedistributorBase;

/**
 *
 * Return whether the Source interrupt index refers to a shared interrupt (SPI)
 */
STATIC
BOOLEAN
SourceIsSpi (
  IN UINTN  Source
  )
{
  return Source >= 32 && Source < 1020;
}

/**
 * Return the base address of the GIC redistributor for the current CPU
 *
 * @retval Base address of the associated GIC Redistributor
 */
STATIC
UINTN
GicGetCpuRedistributorBase (
  IN UINTN  GicRedistributorBase
  )
{
  UINTN       MpId;
  UINTN       CpuAffinity;
  UINTN       Affinity;
  UINTN       GicCpuRedistributorBase;
  UINT64      TypeRegister;
  EFI_STATUS  Status;

  MpId = ArmReadMpidr ();
  // Define CPU affinity as:
  // Affinity0[0:8], Affinity1[9:15], Affinity2[16:23], Affinity3[24:32]
  // whereas Affinity3 is defined at [32:39] in MPIDR
  CpuAffinity = (MpId & (ARM_CORE_AFF0 | ARM_CORE_AFF1 | ARM_CORE_AFF2)) |
                ((MpId & ARM_CORE_AFF3) >> 8);

  GicCpuRedistributorBase = GicRedistributorBase;

  do {
    Status = gCpuArch->SetMemoryAttributes (
                         gCpuArch,
                         GicCpuRedistributorBase,
                         GIC_V3_REDISTRIBUTOR_GRANULARITY,
                         EFI_MEMORY_UC | EFI_MEMORY_XP
                         );
    if (EFI_ERROR (Status)) {
      DEBUG ((
        DEBUG_ERROR,
        "%a: Failed to map GICv3 redistributor MMIO interface at 0x%lx: %r\n",
        __func__,
        GicCpuRedistributorBase,
        Status
        ));
      ASSERT_EFI_ERROR (Status);
      return 0;
    }

    TypeRegister = MmioRead64 (GicCpuRedistributorBase + ARM_GICR_TYPER);
    Affinity     = ARM_GICR_TYPER_GET_AFFINITY (TypeRegister);
    if (Affinity == CpuAffinity) {
      return GicCpuRedistributorBase;
    }

    // Move to the next GIC Redistributor frame.
    // The GIC specification does not forbid a mixture of redistributors
    // with or without support for virtual LPIs, so we test Virtual LPIs
    // Support (VLPIS) bit for each frame to decide the granularity.
    // Note: The assumption here is that the redistributors are adjacent
    // for all CPUs. However this may not be the case for NUMA systems.
    GicCpuRedistributorBase += (((ARM_GICR_TYPER_VLPIS & TypeRegister) != 0)
                                ? GIC_V4_REDISTRIBUTOR_GRANULARITY
                                : GIC_V3_REDISTRIBUTOR_GRANULARITY);
  } while ((TypeRegister & ARM_GICR_TYPER_LAST) == 0);

  // The Redistributor has not been found for the current CPU
  ASSERT_EFI_ERROR (EFI_NOT_FOUND);
  return 0;
}

STATIC
VOID
ArmGicSetInterruptPriority (
  IN UINTN   Source,
  IN UINT32  Priority
  )
{
  UINT32  RegOffset;
  UINT8   RegShift;

  // Calculate register offset and bit position
  RegOffset = (UINT32)(Source / 4);
  RegShift  = (UINT8)((Source % 4) * 8);

  if (SourceIsSpi (Source)) {
    MmioAndThenOr32 (
      mGicDistributorBase + ARM_GIC_ICDIPR + (4 * RegOffset),
      ~(0xff << RegShift),
      Priority << RegShift
      );
  } else {
    MmioAndThenOr32 (
      IPRIORITY_ADDRESS (mGicRedistributorBase, RegOffset),
      ~(0xff << RegShift),
      Priority << RegShift
      );
  }
}

STATIC
VOID
ArmGicEnableInterrupt (
  IN UINTN  Source
  )
{
  UINT32  RegOffset;
  UINT8   RegShift;

  // Calculate enable register offset and bit position
  RegOffset = (UINT32)(Source / 32);
  RegShift  = (UINT8)(Source % 32);

  if (SourceIsSpi (Source)) {
    // Write set-enable register
    MmioWrite32 (
      mGicDistributorBase + ARM_GIC_ICDISER + (4 * RegOffset),
      1 << RegShift
      );
  } else {
    // Write set-enable register
    MmioWrite32 (
      ISENABLER_ADDRESS (mGicRedistributorBase, RegOffset),
      1 << RegShift
      );
  }
}

STATIC
VOID
ArmGicDisableInterrupt (
  IN UINTN  Source
  )
{
  UINT32  RegOffset;
  UINT8   RegShift;

  // Calculate enable register offset and bit position
  RegOffset = (UINT32)(Source / 32);
  RegShift  = (UINT8)(Source % 32);

  if (SourceIsSpi (Source)) {
    // Write clear-enable register
    MmioWrite32 (
      mGicDistributorBase + ARM_GIC_ICDICER + (4 * RegOffset),
      1 << RegShift
      );
  } else {
    // Write clear-enable register
    MmioWrite32 (
      ICENABLER_ADDRESS (mGicRedistributorBase, RegOffset),
      1 << RegShift
      );
  }
}

STATIC
BOOLEAN
ArmGicIsInterruptEnabled (
  IN UINTN  Source
  )
{
  UINT32  RegOffset;
  UINT8   RegShift;
  UINT32  Interrupts;

  // Calculate enable register offset and bit position
  RegOffset = (UINT32)(Source / 32);
  RegShift  = (UINT8)(Source % 32);

  if (SourceIsSpi (Source)) {
    Interrupts = MmioRead32 (
                   mGicDistributorBase + ARM_GIC_ICDISER + (4 * RegOffset)
                   );
  } else {
    // Read set-enable register
    Interrupts = MmioRead32 (
                   ISENABLER_ADDRESS (mGicRedistributorBase, RegOffset)
                   );
  }

  return ((Interrupts & (1 << RegShift)) != 0);
}

/**
  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.

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

  ArmGicEnableInterrupt (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.

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

  ArmGicDisableInterrupt (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

**/
STATIC
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 (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 ended successfully.
  @retval EFI_DEVICE_ERROR  Hardware could not be programmed.

**/
STATIC
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

**/
STATIC
VOID
EFIAPI
GicV3IrqInterruptHandler (
  IN EFI_EXCEPTION_TYPE  InterruptType,
  IN EFI_SYSTEM_CONTEXT  SystemContext
  )
{
  UINTN                       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 ((DEBUG_ERROR, "Spurious GIC interrupt: 0x%x\n", (UINT32)GicInterrupt));
    GicV3EndOfInterrupt (&gHardwareInterruptV3Protocol, GicInterrupt);
  }
}

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

/**
  Get interrupt trigger type of an interrupt

  @param This          Instance pointer for this protocol
  @param Source        Hardware source of the interrupt.
  @param TriggerType   Returns interrupt trigger type.

  @retval EFI_SUCCESS       Source interrupt supported.
  @retval EFI_UNSUPPORTED   Source interrupt is not supported.
**/
STATIC
EFI_STATUS
EFIAPI
GicV3GetTriggerType (
  IN  EFI_HARDWARE_INTERRUPT2_PROTOCOL      *This,
  IN  HARDWARE_INTERRUPT_SOURCE             Source,
  OUT EFI_HARDWARE_INTERRUPT2_TRIGGER_TYPE  *TriggerType
  )
{
  UINTN       RegAddress;
  UINTN       Config1Bit;
  EFI_STATUS  Status;

  Status = GicGetDistributorIcfgBaseAndBit (
             Source,
             &RegAddress,
             &Config1Bit
             );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  if ((MmioRead32 (RegAddress) & (1 << Config1Bit)) == 0) {
    *TriggerType = EFI_HARDWARE_INTERRUPT2_TRIGGER_LEVEL_HIGH;
  } else {
    *TriggerType = EFI_HARDWARE_INTERRUPT2_TRIGGER_EDGE_RISING;
  }

  return EFI_SUCCESS;
}

/**
  Set interrupt trigger type of an interrupt

  @param This          Instance pointer for this protocol
  @param Source        Hardware source of the interrupt.
  @param TriggerType   Interrupt trigger type.

  @retval EFI_SUCCESS       Source interrupt supported.
  @retval EFI_UNSUPPORTED   Source interrupt is not supported.
**/
STATIC
EFI_STATUS
EFIAPI
GicV3SetTriggerType (
  IN  EFI_HARDWARE_INTERRUPT2_PROTOCOL      *This,
  IN  HARDWARE_INTERRUPT_SOURCE             Source,
  IN  EFI_HARDWARE_INTERRUPT2_TRIGGER_TYPE  TriggerType
  )
{
  UINTN       RegAddress;
  UINTN       Config1Bit;
  UINT32      Value;
  EFI_STATUS  Status;
  BOOLEAN     SourceEnabled;

  if (  (TriggerType != EFI_HARDWARE_INTERRUPT2_TRIGGER_EDGE_RISING)
     && (TriggerType != EFI_HARDWARE_INTERRUPT2_TRIGGER_LEVEL_HIGH))
  {
    DEBUG ((
      DEBUG_ERROR,
      "Invalid interrupt trigger type: %d\n", \
      TriggerType
      ));
    ASSERT (FALSE);
    return EFI_UNSUPPORTED;
  }

  Status = GicGetDistributorIcfgBaseAndBit (
             Source,
             &RegAddress,
             &Config1Bit
             );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = GicV3GetInterruptSourceState (
             (EFI_HARDWARE_INTERRUPT_PROTOCOL *)This,
             Source,
             &SourceEnabled
             );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  Value = (TriggerType == EFI_HARDWARE_INTERRUPT2_TRIGGER_EDGE_RISING)
          ?  ARM_GIC_ICDICFR_EDGE_TRIGGERED
          :  ARM_GIC_ICDICFR_LEVEL_TRIGGERED;

  // Before changing the value, we must disable the interrupt,
  // otherwise GIC behavior is UNPREDICTABLE.
  if (SourceEnabled) {
    GicV3DisableInterruptSource (
      (EFI_HARDWARE_INTERRUPT_PROTOCOL *)This,
      Source
      );
  }

  MmioAndThenOr32 (
    RegAddress,
    ~(0x1 << Config1Bit),
    Value << Config1Bit
    );
  // Restore interrupt state
  if (SourceEnabled) {
    GicV3EnableInterruptSource (
      (EFI_HARDWARE_INTERRUPT_PROTOCOL *)This,
      Source
      );
  }

  return EFI_SUCCESS;
}

STATIC
VOID
ArmGicEnableDistributor (
  IN  UINTN  GicDistributorBase
  )
{
  UINT32  GicDistributorCtl;

  GicDistributorCtl = MmioRead32 (GicDistributorBase + ARM_GIC_ICDDCR);
  if ((GicDistributorCtl & ARM_GIC_ICDDCR_ARE) != 0) {
    MmioOr32 (GicDistributorBase + ARM_GIC_ICDDCR, 0x2);
  } else {
    MmioOr32 (GicDistributorBase + ARM_GIC_ICDDCR, 0x1);
  }
}

EFI_HARDWARE_INTERRUPT2_PROTOCOL  gHardwareInterrupt2V3Protocol = {
  (HARDWARE_INTERRUPT2_REGISTER)RegisterInterruptSource,
  (HARDWARE_INTERRUPT2_ENABLE)GicV3EnableInterruptSource,
  (HARDWARE_INTERRUPT2_DISABLE)GicV3DisableInterruptSource,
  (HARDWARE_INTERRUPT2_INTERRUPT_STATE)GicV3GetInterruptSourceState,
  (HARDWARE_INTERRUPT2_END_OF_INTERRUPT)GicV3EndOfInterrupt,
  GicV3GetTriggerType,
  GicV3SetTriggerType
};

/**
  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);
  }

  // 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;
  UINT64      MpId;
  UINT64      CpuTarget;
  UINT64      RegValue;

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

  // Locate the CPU arch protocol - cannot fail because of DEPEX
  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&gCpuArch);
  ASSERT_EFI_ERROR (Status);

  mGicDistributorBase = (UINTN)PcdGet64 (PcdGicDistributorBase);

  Status = gCpuArch->SetMemoryAttributes (gCpuArch, mGicDistributorBase, GICD_V3_SIZE, EFI_MEMORY_UC | EFI_MEMORY_XP);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "%a: Failed to map GICv3 distributor MMIO interface: %r\n", __func__, Status));
    ASSERT_EFI_ERROR (Status);
    return Status;
  }

  mGicRedistributorBase = GicGetCpuRedistributorBase (PcdGet64 (PcdGicRedistributorsBase));
  mGicNumInterrupts     = ArmGicGetMaxNumInterrupts (mGicDistributorBase);

  RegValue = ArmGicV3GetControlSystemRegisterEnable ();
  if ((RegValue & ICC_SRE_EL2_SRE) == 0) {
    ArmGicV3SetControlSystemRegisterEnable (RegValue | ICC_SRE_EL2_SRE);
    ASSERT ((ArmGicV3GetControlSystemRegisterEnable () & ICC_SRE_EL2_SRE) != 0);
  }

  // We will be driving this GIC in native v3 mode, i.e., with Affinity
  // Routing enabled. So ensure that the ARE bit is set.
  MmioOr32 (mGicDistributorBase + ARM_GIC_ICDDCR, ARM_GIC_ICDDCR_ARE);

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

    // Set Priority
    ArmGicSetInterruptPriority (Index, ARM_GIC_DEFAULT_PRIORITY);
  }

  // Targets the interrupts to the Primary Cpu

  MpId      = ArmReadMpidr ();
  CpuTarget = MpId &
              (ARM_CORE_AFF0 | ARM_CORE_AFF1 | ARM_CORE_AFF2 | ARM_CORE_AFF3);

  if ((MmioRead32 (
         mGicDistributorBase + ARM_GIC_ICDDCR
         ) & ARM_GIC_ICDDCR_DS) != 0)
  {
    // If the Disable Security (DS) control bit is set, we are dealing with a
    // GIC that has only one security state. In this case, let's assume we are
    // executing in non-secure state (which is appropriate for DXE modules)
    // and that no other firmware has performed any configuration on the GIC.
    // This means we need to reconfigure all interrupts to non-secure Group 1
    // first.

    MmioWrite32 (
      mGicRedistributorBase + ARM_GICR_CTLR_FRAME_SIZE + ARM_GIC_ICDISR,
      0xffffffff
      );

    for (Index = 32; Index < mGicNumInterrupts; Index += 32) {
      MmioWrite32 (
        mGicDistributorBase + ARM_GIC_ICDISR + Index / 8,
        0xffffffff
        );
    }

    // Route the SPIs to the primary CPU. SPIs start at the INTID 32
    for (Index = 0; Index < (mGicNumInterrupts - 32); Index++) {
      MmioWrite64 (
        mGicDistributorBase + ARM_GICD_IROUTER + (Index * 8),
        CpuTarget
        );
    }
  }

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

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

  // Use combined priority drop and deactivate (EOImode == 0)
  RegValue  = ArmGicV3GetControlRegister ();
  RegValue &= ~(UINT64)ICC_CTLR_EOImode;
  ArmGicV3SetControlRegister (RegValue);

  // Enable gic cpu interface
  ArmGicV3EnableInterruptInterface ();

  // Enable gic distributor
  ArmGicEnableDistributor (mGicDistributorBase);

  Status = InstallAndRegisterInterruptService (
             &gHardwareInterruptV3Protocol,
             &gHardwareInterrupt2V3Protocol,
             GicV3IrqInterruptHandler,
             GicV3ExitBootServicesEvent
             );

  return Status;
}