// SPDX-License-Identifier: MIT
#include <cstdint>
#include <type_traits>
#include <sys/prctl.h>

#include "FEXUnixLib.h"

// Equivalent to C++23's std::to_underlying.
template<typename Enum>
[[nodiscard]]
constexpr std::underlying_type_t<Enum> ToUnderlying(Enum e) noexcept {
  return static_cast<std::underlying_type_t<Enum>>(e);
}

using NTSTATUS = int32_t;
using unixlib_entry_t = NTSTATUS (*)(void*);

constexpr NTSTATUS STATUS_SUCCESS = 0;
constexpr NTSTATUS STATUS_NOT_SUPPORTED = 0xC00000BB;
constexpr NTSTATUS STATUS_INTERNAL_ERROR = 0xC00000E5;

#ifndef PR_GET_MEM_MODEL
#define PR_GET_MEM_MODEL 0x6d4d444c
#endif
#ifndef PR_SET_MEM_MODEL
#define PR_SET_MEM_MODEL 0x4d4d444c
#endif
#ifndef PR_SET_MEM_MODEL_DEFAULT
#define PR_SET_MEM_MODEL_DEFAULT 0
#endif
#ifndef PR_SET_MEM_MODEL_TSO
#define PR_SET_MEM_MODEL_TSO 1
#endif

static NTSTATUS FEXUnixLib_SetHardwareTSOControlHandler(void* _Args) {
  auto Args = reinterpret_cast<const FEXUnixLib_SetHardwareTSOControlArgs*>(_Args);
  if (Args->Enable) {
    int ret = prctl(PR_GET_MEM_MODEL, 0, 0, 0, 0);
    if (ret == PR_SET_MEM_MODEL_DEFAULT) {
      return prctl(PR_SET_MEM_MODEL, PR_SET_MEM_MODEL_TSO, 0, 0, 0) ? STATUS_NOT_SUPPORTED : STATUS_SUCCESS;
    }
    return ret == PR_SET_MEM_MODEL_TSO ? STATUS_SUCCESS : STATUS_NOT_SUPPORTED;
  }

  prctl(PR_SET_MEM_MODEL, PR_SET_MEM_MODEL_DEFAULT, 0, 0, 0);
  return STATUS_SUCCESS;
}

extern "C" const unixlib_entry_t __wine_unix_call_funcs[] = {FEXUnixLib_SetHardwareTSOControlHandler};

static_assert(sizeof(__wine_unix_call_funcs) / sizeof(__wine_unix_call_funcs[0]) == ToUnderlying(FEXUnixLibFunctions::MAX));