// Copyright 2008 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <atomic>
#include <cstring>

#include "Common/Assert.h"
#include "Common/ChunkFile.h"
#include "Common/CommonTypes.h"
#include "Common/Flag.h"
#include "Common/Logging/Log.h"
#include "Core/ConfigManager.h"
#include "Core/CoreTiming.h"
#include "Core/HW/GPFifo.h"
#include "Core/HW/MMIO.h"
#include "Core/HW/ProcessorInterface.h"
#include "VideoCommon/CommandProcessor.h"
#include "VideoCommon/Fifo.h"

namespace CommandProcessor
{
static CoreTiming::EventType* et_UpdateInterrupts;

// TODO(ector): Warn on bbox read/write

// STATE_TO_SAVE
SCPFifoStruct fifo;
static UCPStatusReg m_CPStatusReg;
static UCPCtrlReg m_CPCtrlReg;
static UCPClearReg m_CPClearReg;

static u16 m_bboxleft;
static u16 m_bboxtop;
static u16 m_bboxright;
static u16 m_bboxbottom;
static u16 m_tokenReg;

static Common::Flag s_interrupt_set;
static Common::Flag s_interrupt_waiting;

static bool IsOnThread()
{
  return SConfig::GetInstance().bCPUThread;
}

static void UpdateInterrupts_Wrapper(u64 userdata, s64 cyclesLate)
{
  UpdateInterrupts(userdata);
}

void SCPFifoStruct::Init()
{
  CPBase = 0;
  CPEnd = 0;
  CPHiWatermark = 0;
  CPLoWatermark = 0;
  CPReadWriteDistance = 0;
  CPWritePointer = 0;
  CPReadPointer = 0;
  CPBreakpoint = 0;
  SafeCPReadPointer = 0;

  bFF_GPLinkEnable = 0;
  bFF_GPReadEnable = 0;
  bFF_BPEnable = 0;
  bFF_BPInt = 0;

  bFF_Breakpoint.store(0, std::memory_order_relaxed);
  bFF_HiWatermark.store(0, std::memory_order_relaxed);
  bFF_HiWatermarkInt.store(0, std::memory_order_relaxed);
  bFF_LoWatermark.store(0, std::memory_order_relaxed);
  bFF_LoWatermarkInt.store(0, std::memory_order_relaxed);
}

void SCPFifoStruct::DoState(PointerWrap& p)
{
  p.Do(CPBase);
  p.Do(CPEnd);
  p.Do(CPHiWatermark);
  p.Do(CPLoWatermark);
  p.Do(CPReadWriteDistance);
  p.Do(CPWritePointer);
  p.Do(CPReadPointer);
  p.Do(CPBreakpoint);
  p.Do(SafeCPReadPointer);

  p.Do(bFF_GPLinkEnable);
  p.Do(bFF_GPReadEnable);
  p.Do(bFF_BPEnable);
  p.Do(bFF_BPInt);
  p.Do(bFF_Breakpoint);

  p.Do(bFF_LoWatermarkInt);
  p.Do(bFF_HiWatermarkInt);

  p.Do(bFF_LoWatermark);
  p.Do(bFF_HiWatermark);
}

void DoState(PointerWrap& p)
{
  p.DoPOD(m_CPStatusReg);
  p.DoPOD(m_CPCtrlReg);
  p.DoPOD(m_CPClearReg);
  p.Do(m_bboxleft);
  p.Do(m_bboxtop);
  p.Do(m_bboxright);
  p.Do(m_bboxbottom);
  p.Do(m_tokenReg);
  fifo.DoState(p);

  p.Do(s_interrupt_set);
  p.Do(s_interrupt_waiting);
}

static inline void WriteLow(std::atomic<u32>& reg, u16 lowbits)
{
  reg.store((reg.load(std::memory_order_relaxed) & 0xFFFF0000) | lowbits,
            std::memory_order_relaxed);
}
static inline void WriteHigh(std::atomic<u32>& reg, u16 highbits)
{
  reg.store((reg.load(std::memory_order_relaxed) & 0x0000FFFF) | (static_cast<u32>(highbits) << 16),
            std::memory_order_relaxed);
}

void Init()
{
  m_CPStatusReg.Hex = 0;
  m_CPStatusReg.CommandIdle = 1;
  m_CPStatusReg.ReadIdle = 1;

  m_CPCtrlReg.Hex = 0;

  m_CPClearReg.Hex = 0;

  m_bboxleft = 0;
  m_bboxtop = 0;
  m_bboxright = 640;
  m_bboxbottom = 480;

  m_tokenReg = 0;

  fifo.Init();

  s_interrupt_set.Clear();
  s_interrupt_waiting.Clear();

  et_UpdateInterrupts = CoreTiming::RegisterEvent("CPInterrupt", UpdateInterrupts_Wrapper);
}

u32 GetPhysicalAddressMask()
{
  // Physical addresses in CP seem to ignore some of the upper bits (depending on platform)
  // This can be observed in CP MMIO registers by setting to 0xffffffff and then reading back.
  return SConfig::GetInstance().bWii ? 0x1fffffff : 0x03ffffff;
}

void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
{
  constexpr u16 WMASK_NONE = 0x0000;
  constexpr u16 WMASK_ALL = 0xffff;
  constexpr u16 WMASK_LO_ALIGN_32BIT = 0xffe0;
  const u16 WMASK_HI_RESTRICT = GetPhysicalAddressMask() >> 16;

  struct
  {
    u32 addr;
    u16* ptr;
    bool readonly;
    // FIFO mmio regs in the range [cc000020-cc00003e] have certain bits that always read as 0
    // For _LO registers in this range, only bits 0xffe0 can be set
    // For _HI registers in this range, only bits 0x03ff can be set on GCN and 0x1fff on Wii
    u16 wmask;
  } directly_mapped_vars[] = {
      {FIFO_TOKEN_REGISTER, &m_tokenReg, false, WMASK_ALL},

      // Bounding box registers are read only.
      {FIFO_BOUNDING_BOX_LEFT, &m_bboxleft, true, WMASK_NONE},
      {FIFO_BOUNDING_BOX_RIGHT, &m_bboxright, true, WMASK_NONE},
      {FIFO_BOUNDING_BOX_TOP, &m_bboxtop, true, WMASK_NONE},
      {FIFO_BOUNDING_BOX_BOTTOM, &m_bboxbottom, true, WMASK_NONE},
      {FIFO_BASE_LO, MMIO::Utils::LowPart(&fifo.CPBase), false, WMASK_LO_ALIGN_32BIT},
      {FIFO_BASE_HI, MMIO::Utils::HighPart(&fifo.CPBase), false, WMASK_HI_RESTRICT},
      {FIFO_END_LO, MMIO::Utils::LowPart(&fifo.CPEnd), false, WMASK_LO_ALIGN_32BIT},
      {FIFO_END_HI, MMIO::Utils::HighPart(&fifo.CPEnd), false, WMASK_HI_RESTRICT},
      {FIFO_HI_WATERMARK_LO, MMIO::Utils::LowPart(&fifo.CPHiWatermark), false,
       WMASK_LO_ALIGN_32BIT},
      {FIFO_HI_WATERMARK_HI, MMIO::Utils::HighPart(&fifo.CPHiWatermark), false, WMASK_HI_RESTRICT},
      {FIFO_LO_WATERMARK_LO, MMIO::Utils::LowPart(&fifo.CPLoWatermark), false,
       WMASK_LO_ALIGN_32BIT},
      {FIFO_LO_WATERMARK_HI, MMIO::Utils::HighPart(&fifo.CPLoWatermark), false, WMASK_HI_RESTRICT},
      // FIFO_RW_DISTANCE has some complex read code different for
      // single/dual core.
      {FIFO_WRITE_POINTER_LO, MMIO::Utils::LowPart(&fifo.CPWritePointer), false,
       WMASK_LO_ALIGN_32BIT},
      {FIFO_WRITE_POINTER_HI, MMIO::Utils::HighPart(&fifo.CPWritePointer), false,
       WMASK_HI_RESTRICT},
      // FIFO_READ_POINTER has different code for single/dual core.
  };

  for (auto& mapped_var : directly_mapped_vars)
  {
    mmio->Register(base | mapped_var.addr, MMIO::DirectRead<u16>(mapped_var.ptr),
                   mapped_var.readonly ? MMIO::InvalidWrite<u16>() :
                                         MMIO::DirectWrite<u16>(mapped_var.ptr, mapped_var.wmask));
  }

  mmio->Register(base | FIFO_BP_LO, MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.CPBreakpoint)),
                 MMIO::ComplexWrite<u16>([](u32, u16 val) {
                   WriteLow(fifo.CPBreakpoint, val & WMASK_LO_ALIGN_32BIT);
                 }));
  mmio->Register(base | FIFO_BP_HI,
                 MMIO::DirectRead<u16>(MMIO::Utils::HighPart(&fifo.CPBreakpoint)),
                 MMIO::ComplexWrite<u16>([WMASK_HI_RESTRICT](u32, u16 val) {
                   WriteHigh(fifo.CPBreakpoint, val & WMASK_HI_RESTRICT);
                 }));

  // Timing and metrics MMIOs are stubbed with fixed values.
  struct
  {
    u32 addr;
    u16 value;
  } metrics_mmios[] = {
      {XF_RASBUSY_L, 0},
      {XF_RASBUSY_H, 0},
      {XF_CLKS_L, 0},
      {XF_CLKS_H, 0},
      {XF_WAIT_IN_L, 0},
      {XF_WAIT_IN_H, 0},
      {XF_WAIT_OUT_L, 0},
      {XF_WAIT_OUT_H, 0},
      {VCACHE_METRIC_CHECK_L, 0},
      {VCACHE_METRIC_CHECK_H, 0},
      {VCACHE_METRIC_MISS_L, 0},
      {VCACHE_METRIC_MISS_H, 0},
      {VCACHE_METRIC_STALL_L, 0},
      {VCACHE_METRIC_STALL_H, 0},
      {CLKS_PER_VTX_OUT, 4},
  };
  for (auto& metrics_mmio : metrics_mmios)
  {
    mmio->Register(base | metrics_mmio.addr, MMIO::Constant<u16>(metrics_mmio.value),
                   MMIO::InvalidWrite<u16>());
  }

  mmio->Register(base | STATUS_REGISTER, MMIO::ComplexRead<u16>([](u32) {
                   Fifo::SyncGPUForRegisterAccess();
                   SetCpStatusRegister();
                   return m_CPStatusReg.Hex;
                 }),
                 MMIO::InvalidWrite<u16>());

  mmio->Register(base | CTRL_REGISTER, MMIO::DirectRead<u16>(&m_CPCtrlReg.Hex),
                 MMIO::ComplexWrite<u16>([](u32, u16 val) {
                   UCPCtrlReg tmp(val);
                   m_CPCtrlReg.Hex = tmp.Hex;
                   SetCpControlRegister();
                   Fifo::RunGpu();
                 }));

  mmio->Register(base | CLEAR_REGISTER, MMIO::DirectRead<u16>(&m_CPClearReg.Hex),
                 MMIO::ComplexWrite<u16>([](u32, u16 val) {
                   UCPClearReg tmp(val);
                   m_CPClearReg.Hex = tmp.Hex;
                   SetCpClearRegister();
                   Fifo::RunGpu();
                 }));

  mmio->Register(base | PERF_SELECT, MMIO::InvalidRead<u16>(), MMIO::Nop<u16>());

  // Some MMIOs have different handlers for single core vs. dual core mode.
  mmio->Register(
      base | FIFO_RW_DISTANCE_LO,
      IsOnThread() ? MMIO::ComplexRead<u16>([](u32) {
        if (fifo.CPWritePointer.load(std::memory_order_relaxed) >=
            fifo.SafeCPReadPointer.load(std::memory_order_relaxed))
        {
          return static_cast<u16>(fifo.CPWritePointer.load(std::memory_order_relaxed) -
                                  fifo.SafeCPReadPointer.load(std::memory_order_relaxed));
        }
        else
        {
          return static_cast<u16>(fifo.CPEnd.load(std::memory_order_relaxed) -
                                  fifo.SafeCPReadPointer.load(std::memory_order_relaxed) +
                                  fifo.CPWritePointer.load(std::memory_order_relaxed) -
                                  fifo.CPBase.load(std::memory_order_relaxed) + 32);
        }
      }) :
                     MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.CPReadWriteDistance)),
      MMIO::DirectWrite<u16>(MMIO::Utils::LowPart(&fifo.CPReadWriteDistance),
                             WMASK_LO_ALIGN_32BIT));
  mmio->Register(base | FIFO_RW_DISTANCE_HI,
                 IsOnThread() ?
                     MMIO::ComplexRead<u16>([](u32) {
                       Fifo::SyncGPUForRegisterAccess();
                       if (fifo.CPWritePointer.load(std::memory_order_relaxed) >=
                           fifo.SafeCPReadPointer.load(std::memory_order_relaxed))
                       {
                         return (fifo.CPWritePointer.load(std::memory_order_relaxed) -
                                 fifo.SafeCPReadPointer.load(std::memory_order_relaxed)) >>
                                16;
                       }
                       else
                       {
                         return (fifo.CPEnd.load(std::memory_order_relaxed) -
                                 fifo.SafeCPReadPointer.load(std::memory_order_relaxed) +
                                 fifo.CPWritePointer.load(std::memory_order_relaxed) -
                                 fifo.CPBase.load(std::memory_order_relaxed) + 32) >>
                                16;
                       }
                     }) :
                     MMIO::ComplexRead<u16>([](u32) {
                       Fifo::SyncGPUForRegisterAccess();
                       return fifo.CPReadWriteDistance.load(std::memory_order_relaxed) >> 16;
                     }),
                 MMIO::ComplexWrite<u16>([WMASK_HI_RESTRICT](u32, u16 val) {
                   Fifo::SyncGPUForRegisterAccess();
                   WriteHigh(fifo.CPReadWriteDistance, val & WMASK_HI_RESTRICT);
                   Fifo::RunGpu();
                 }));
  mmio->Register(
      base | FIFO_READ_POINTER_LO,
      IsOnThread() ? MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.SafeCPReadPointer)) :
                     MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.CPReadPointer)),
      MMIO::DirectWrite<u16>(MMIO::Utils::LowPart(&fifo.CPReadPointer), WMASK_LO_ALIGN_32BIT));
  mmio->Register(base | FIFO_READ_POINTER_HI,
                 IsOnThread() ? MMIO::ComplexRead<u16>([](u32) {
                   Fifo::SyncGPUForRegisterAccess();
                   return fifo.SafeCPReadPointer.load(std::memory_order_relaxed) >> 16;
                 }) :
                                MMIO::ComplexRead<u16>([](u32) {
                                  Fifo::SyncGPUForRegisterAccess();
                                  return fifo.CPReadPointer.load(std::memory_order_relaxed) >> 16;
                                }),
                 IsOnThread() ? MMIO::ComplexWrite<u16>([WMASK_HI_RESTRICT](u32, u16 val) {
                   Fifo::SyncGPUForRegisterAccess();
                   WriteHigh(fifo.CPReadPointer, val & WMASK_HI_RESTRICT);
                   fifo.SafeCPReadPointer.store(fifo.CPReadPointer.load(std::memory_order_relaxed),
                                                std::memory_order_relaxed);
                 }) :
                                MMIO::ComplexWrite<u16>([WMASK_HI_RESTRICT](u32, u16 val) {
                                  Fifo::SyncGPUForRegisterAccess();
                                  WriteHigh(fifo.CPReadPointer, val & WMASK_HI_RESTRICT);
                                }));
}

void GatherPipeBursted()
{
  SetCPStatusFromCPU();

  // if we aren't linked, we don't care about gather pipe data
  if (!m_CPCtrlReg.GPLinkEnable)
  {
    if (IsOnThread() && !Fifo::UseDeterministicGPUThread())
    {
      // In multibuffer mode is not allowed write in the same FIFO attached to the GPU.
      // Fix Pokemon XD in DC mode.
      if ((ProcessorInterface::Fifo_CPUEnd == fifo.CPEnd.load(std::memory_order_relaxed)) &&
          (ProcessorInterface::Fifo_CPUBase == fifo.CPBase.load(std::memory_order_relaxed)) &&
          fifo.CPReadWriteDistance.load(std::memory_order_relaxed) > 0)
      {
        Fifo::FlushGpu();
      }
    }
    Fifo::RunGpu();
    return;
  }

  // update the fifo pointer
  if (fifo.CPWritePointer.load(std::memory_order_relaxed) ==
      fifo.CPEnd.load(std::memory_order_relaxed))
  {
    fifo.CPWritePointer.store(fifo.CPBase, std::memory_order_relaxed);
  }
  else
  {
    fifo.CPWritePointer.fetch_add(GATHER_PIPE_SIZE, std::memory_order_relaxed);
  }

  if (m_CPCtrlReg.GPReadEnable && m_CPCtrlReg.GPLinkEnable)
  {
    ProcessorInterface::Fifo_CPUWritePointer = fifo.CPWritePointer.load(std::memory_order_relaxed);
    ProcessorInterface::Fifo_CPUBase = fifo.CPBase.load(std::memory_order_relaxed);
    ProcessorInterface::Fifo_CPUEnd = fifo.CPEnd.load(std::memory_order_relaxed);
  }

  // If the game is running close to overflowing, make the exception checking more frequent.
  if (fifo.bFF_HiWatermark.load(std::memory_order_relaxed) != 0)
    CoreTiming::ForceExceptionCheck(0);

  fifo.CPReadWriteDistance.fetch_add(GATHER_PIPE_SIZE, std::memory_order_seq_cst);

  Fifo::RunGpu();

  ASSERT_MSG(COMMANDPROCESSOR,
             fifo.CPReadWriteDistance.load(std::memory_order_relaxed) <=
                 fifo.CPEnd.load(std::memory_order_relaxed) -
                     fifo.CPBase.load(std::memory_order_relaxed),
             "FIFO is overflowed by GatherPipe !\nCPU thread is too fast!");

  // check if we are in sync
  ASSERT_MSG(COMMANDPROCESSOR,
             fifo.CPWritePointer.load(std::memory_order_relaxed) ==
                 ProcessorInterface::Fifo_CPUWritePointer,
             "FIFOs linked but out of sync");
  ASSERT_MSG(COMMANDPROCESSOR,
             fifo.CPBase.load(std::memory_order_relaxed) == ProcessorInterface::Fifo_CPUBase,
             "FIFOs linked but out of sync");
  ASSERT_MSG(COMMANDPROCESSOR,
             fifo.CPEnd.load(std::memory_order_relaxed) == ProcessorInterface::Fifo_CPUEnd,
             "FIFOs linked but out of sync");
}

void UpdateInterrupts(u64 userdata)
{
  if (userdata)
  {
    s_interrupt_set.Set();
    DEBUG_LOG_FMT(COMMANDPROCESSOR, "Interrupt set");
    ProcessorInterface::SetInterrupt(INT_CAUSE_CP, true);
  }
  else
  {
    s_interrupt_set.Clear();
    DEBUG_LOG_FMT(COMMANDPROCESSOR, "Interrupt cleared");
    ProcessorInterface::SetInterrupt(INT_CAUSE_CP, false);
  }
  CoreTiming::ForceExceptionCheck(0);
  s_interrupt_waiting.Clear();
  Fifo::RunGpu();
}

void UpdateInterruptsFromVideoBackend(u64 userdata)
{
  if (!Fifo::UseDeterministicGPUThread())
    CoreTiming::ScheduleEvent(0, et_UpdateInterrupts, userdata, CoreTiming::FromThread::NON_CPU);
}

bool IsInterruptWaiting()
{
  return s_interrupt_waiting.IsSet();
}

void SetCPStatusFromGPU()
{
  // breakpoint
  const bool breakpoint = fifo.bFF_Breakpoint.load(std::memory_order_relaxed);
  if (fifo.bFF_BPEnable.load(std::memory_order_relaxed) != 0)
  {
    if (fifo.CPBreakpoint.load(std::memory_order_relaxed) ==
        fifo.CPReadPointer.load(std::memory_order_relaxed))
    {
      if (!breakpoint)
      {
        DEBUG_LOG_FMT(COMMANDPROCESSOR, "Hit breakpoint at {}",
                      fifo.CPReadPointer.load(std::memory_order_relaxed));
        fifo.bFF_Breakpoint.store(1, std::memory_order_relaxed);
      }
    }
    else
    {
      if (breakpoint)
      {
        DEBUG_LOG_FMT(COMMANDPROCESSOR, "Cleared breakpoint at {}",
                      fifo.CPReadPointer.load(std::memory_order_relaxed));
        fifo.bFF_Breakpoint.store(0, std::memory_order_relaxed);
      }
    }
  }
  else
  {
    if (breakpoint)
    {
      DEBUG_LOG_FMT(COMMANDPROCESSOR, "Cleared breakpoint at {}",
                    fifo.CPReadPointer.load(std::memory_order_relaxed));
      fifo.bFF_Breakpoint = false;
    }
  }

  // overflow & underflow check
  fifo.bFF_HiWatermark.store(
      (fifo.CPReadWriteDistance.load(std::memory_order_relaxed) > fifo.CPHiWatermark),
      std::memory_order_relaxed);
  fifo.bFF_LoWatermark.store(
      (fifo.CPReadWriteDistance.load(std::memory_order_relaxed) < fifo.CPLoWatermark),
      std::memory_order_relaxed);

  bool bpInt = fifo.bFF_Breakpoint.load(std::memory_order_relaxed) &&
               fifo.bFF_BPInt.load(std::memory_order_relaxed);
  bool ovfInt = fifo.bFF_HiWatermark.load(std::memory_order_relaxed) &&
                fifo.bFF_HiWatermarkInt.load(std::memory_order_relaxed);
  bool undfInt = fifo.bFF_LoWatermark.load(std::memory_order_relaxed) &&
                 fifo.bFF_LoWatermarkInt.load(std::memory_order_relaxed);

  bool interrupt = (bpInt || ovfInt || undfInt) && m_CPCtrlReg.GPReadEnable;

  if (interrupt != s_interrupt_set.IsSet() && !s_interrupt_waiting.IsSet())
  {
    u64 userdata = interrupt ? 1 : 0;
    if (IsOnThread())
    {
      if (!interrupt || bpInt || undfInt || ovfInt)
      {
        // Schedule the interrupt asynchronously
        s_interrupt_waiting.Set();
        CommandProcessor::UpdateInterruptsFromVideoBackend(userdata);
      }
    }
    else
    {
      CommandProcessor::UpdateInterrupts(userdata);
    }
  }
}

void SetCPStatusFromCPU()
{
  // overflow & underflow check
  fifo.bFF_HiWatermark.store(
      (fifo.CPReadWriteDistance.load(std::memory_order_relaxed) > fifo.CPHiWatermark),
      std::memory_order_relaxed);
  fifo.bFF_LoWatermark.store(
      (fifo.CPReadWriteDistance.load(std::memory_order_relaxed) < fifo.CPLoWatermark),
      std::memory_order_relaxed);

  bool bpInt = fifo.bFF_Breakpoint.load(std::memory_order_relaxed) &&
               fifo.bFF_BPInt.load(std::memory_order_relaxed);
  bool ovfInt = fifo.bFF_HiWatermark.load(std::memory_order_relaxed) &&
                fifo.bFF_HiWatermarkInt.load(std::memory_order_relaxed);
  bool undfInt = fifo.bFF_LoWatermark.load(std::memory_order_relaxed) &&
                 fifo.bFF_LoWatermarkInt.load(std::memory_order_relaxed);

  bool interrupt = (bpInt || ovfInt || undfInt) && m_CPCtrlReg.GPReadEnable;

  if (interrupt != s_interrupt_set.IsSet() && !s_interrupt_waiting.IsSet())
  {
    u64 userdata = interrupt ? 1 : 0;
    if (IsOnThread())
    {
      if (!interrupt || bpInt || undfInt || ovfInt)
      {
        s_interrupt_set.Set(interrupt);
        DEBUG_LOG_FMT(COMMANDPROCESSOR, "Interrupt set");
        ProcessorInterface::SetInterrupt(INT_CAUSE_CP, interrupt);
      }
    }
    else
    {
      CommandProcessor::UpdateInterrupts(userdata);
    }
  }
}

void SetCpStatusRegister()
{
  // Here always there is one fifo attached to the GPU
  m_CPStatusReg.Breakpoint = fifo.bFF_Breakpoint.load(std::memory_order_relaxed);
  m_CPStatusReg.ReadIdle = !fifo.CPReadWriteDistance.load(std::memory_order_relaxed) ||
                           (fifo.CPReadPointer.load(std::memory_order_relaxed) ==
                            fifo.CPWritePointer.load(std::memory_order_relaxed));
  m_CPStatusReg.CommandIdle = !fifo.CPReadWriteDistance.load(std::memory_order_relaxed) ||
                              Fifo::AtBreakpoint() ||
                              !fifo.bFF_GPReadEnable.load(std::memory_order_relaxed);
  m_CPStatusReg.UnderflowLoWatermark = fifo.bFF_LoWatermark.load(std::memory_order_relaxed);
  m_CPStatusReg.OverflowHiWatermark = fifo.bFF_HiWatermark.load(std::memory_order_relaxed);

  DEBUG_LOG_FMT(COMMANDPROCESSOR, "\t Read from STATUS_REGISTER : {:04x}", m_CPStatusReg.Hex);
  DEBUG_LOG_FMT(
      COMMANDPROCESSOR, "(r) status: iBP {} | fReadIdle {} | fCmdIdle {} | iOvF {} | iUndF {}",
      m_CPStatusReg.Breakpoint ? "ON" : "OFF", m_CPStatusReg.ReadIdle ? "ON" : "OFF",
      m_CPStatusReg.CommandIdle ? "ON" : "OFF", m_CPStatusReg.OverflowHiWatermark ? "ON" : "OFF",
      m_CPStatusReg.UnderflowLoWatermark ? "ON" : "OFF");
}

void SetCpControlRegister()
{
  fifo.bFF_BPInt.store(m_CPCtrlReg.BPInt, std::memory_order_relaxed);
  fifo.bFF_BPEnable.store(m_CPCtrlReg.BPEnable, std::memory_order_relaxed);
  fifo.bFF_HiWatermarkInt.store(m_CPCtrlReg.FifoOverflowIntEnable, std::memory_order_relaxed);
  fifo.bFF_LoWatermarkInt.store(m_CPCtrlReg.FifoUnderflowIntEnable, std::memory_order_relaxed);
  fifo.bFF_GPLinkEnable.store(m_CPCtrlReg.GPLinkEnable, std::memory_order_relaxed);

  if (fifo.bFF_GPReadEnable.load(std::memory_order_relaxed) && !m_CPCtrlReg.GPReadEnable)
  {
    fifo.bFF_GPReadEnable.store(m_CPCtrlReg.GPReadEnable, std::memory_order_relaxed);
    Fifo::FlushGpu();
  }
  else
  {
    fifo.bFF_GPReadEnable = m_CPCtrlReg.GPReadEnable;
  }

  DEBUG_LOG_FMT(COMMANDPROCESSOR, "\t GPREAD {} | BP {} | Int {} | OvF {} | UndF {} | LINK {}",
                fifo.bFF_GPReadEnable.load(std::memory_order_relaxed) ? "ON" : "OFF",
                fifo.bFF_BPEnable.load(std::memory_order_relaxed) ? "ON" : "OFF",
                fifo.bFF_BPInt.load(std::memory_order_relaxed) ? "ON" : "OFF",
                m_CPCtrlReg.FifoOverflowIntEnable ? "ON" : "OFF",
                m_CPCtrlReg.FifoUnderflowIntEnable ? "ON" : "OFF",
                m_CPCtrlReg.GPLinkEnable ? "ON" : "OFF");
}

// NOTE: We intentionally don't emulate this function at the moment.
// We don't emulate proper GP timing anyway at the moment, so it would just slow down emulation.
void SetCpClearRegister()
{
}

void HandleUnknownOpcode(u8 cmd_byte, void* buffer, bool preprocess)
{
  // TODO(Omega): Maybe dump FIFO to file on this error
  PanicAlertFmtT("GFX FIFO: Unknown Opcode ({0:#04x} @ {1}, {2}).\n"
                 "This means one of the following:\n"
                 "* The emulated GPU got desynced, disabling dual core can help\n"
                 "* Command stream corrupted by some spurious memory bug\n"
                 "* This really is an unknown opcode (unlikely)\n"
                 "* Some other sort of bug\n\n"
                 "Further errors will be sent to the Video Backend log and\n"
                 "Dolphin will now likely crash or hang. Enjoy.",
                 cmd_byte, buffer, preprocess ? "preprocess=true" : "preprocess=false");

  {
    PanicAlertFmt("Illegal command {:02x}\n"
                  "CPBase: {:#010x}\n"
                  "CPEnd: {:#010x}\n"
                  "CPHiWatermark: {:#010x}\n"
                  "CPLoWatermark: {:#010x}\n"
                  "CPReadWriteDistance: {:#010x}\n"
                  "CPWritePointer: {:#010x}\n"
                  "CPReadPointer: {:#010x}\n"
                  "CPBreakpoint: {:#010x}\n"
                  "bFF_GPReadEnable: {}\n"
                  "bFF_BPEnable: {}\n"
                  "bFF_BPInt: {}\n"
                  "bFF_Breakpoint: {}\n"
                  "bFF_GPLinkEnable: {}\n"
                  "bFF_HiWatermarkInt: {}\n"
                  "bFF_LoWatermarkInt: {}\n",
                  cmd_byte, fifo.CPBase.load(std::memory_order_relaxed),
                  fifo.CPEnd.load(std::memory_order_relaxed), fifo.CPHiWatermark,
                  fifo.CPLoWatermark, fifo.CPReadWriteDistance.load(std::memory_order_relaxed),
                  fifo.CPWritePointer.load(std::memory_order_relaxed),
                  fifo.CPReadPointer.load(std::memory_order_relaxed),
                  fifo.CPBreakpoint.load(std::memory_order_relaxed),
                  fifo.bFF_GPReadEnable.load(std::memory_order_relaxed) ? "true" : "false",
                  fifo.bFF_BPEnable.load(std::memory_order_relaxed) ? "true" : "false",
                  fifo.bFF_BPInt.load(std::memory_order_relaxed) ? "true" : "false",
                  fifo.bFF_Breakpoint.load(std::memory_order_relaxed) ? "true" : "false",
                  fifo.bFF_GPLinkEnable.load(std::memory_order_relaxed) ? "true" : "false",
                  fifo.bFF_HiWatermarkInt.load(std::memory_order_relaxed) ? "true" : "false",
                  fifo.bFF_LoWatermarkInt.load(std::memory_order_relaxed) ? "true" : "false");
  }
}

}  // namespace CommandProcessor