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// SPDX-FileCopyrightText: Copyright (c) 2023 merryhime <https://mary.rs>
// SPDX-License-Identifier: MIT
#pragma once
#include <array>
#include <cstddef>
#include <cstdint>
#include <optional>
#include <string>
#include <aarch64/armreg.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include "oaknut/feature_detection/cpu_feature.hpp"
#include "oaknut/feature_detection/feature_detection_hwcaps.hpp"
#include "oaknut/feature_detection/feature_detection_idregs.hpp"
#include "oaknut/feature_detection/id_registers.hpp"
namespace oaknut {
inline std::optional<id::IdRegisters> read_id_registers(std::size_t core_index)
{
const std::string path = "machdep.cpu" + std::to_string(core_index) + ".cpu_id";
aarch64_sysctl_cpu_id id;
std::size_t id_len = sizeof id;
if (sysctlbyname(path.c_str(), &id, &id_len, nullptr, 0) < 0)
return std::nullopt;
return id::IdRegisters{
id.ac_midr,
id::Pfr0Register{id.ac_aa64pfr0},
id::Pfr1Register{id.ac_aa64pfr1},
id::Pfr2Register{0},
id::Zfr0Register{id.ac_aa64zfr0},
id::Smfr0Register{0},
id::Isar0Register{id.ac_aa64isar0},
id::Isar1Register{id.ac_aa64isar1},
id::Isar2Register{0},
id::Isar3Register{0},
id::Mmfr0Register{id.ac_aa64mmfr0},
id::Mmfr1Register{id.ac_aa64mmfr1},
id::Mmfr2Register{id.ac_aa64mmfr2},
id::Mmfr3Register{0},
id::Mmfr4Register{0},
};
}
inline std::size_t get_core_count()
{
int result = 0;
size_t result_size = sizeof(result);
const std::array<int, 2> mib{CTL_HW, HW_NCPU};
if (sysctl(mib.data(), mib.size(), &result, &result_size, nullptr, 0) < 0)
return 0;
return result;
}
inline CpuFeatures detect_features()
{
std::optional<CpuFeatures> result;
const std::size_t core_count = get_core_count();
for (std::size_t core_index = 0; core_index < core_count; core_index++) {
if (const std::optional<id::IdRegisters> id_regs = read_id_registers(core_index)) {
const CpuFeatures current_features = detect_features_via_id_registers(*id_regs);
if (result) {
result = *result & current_features;
} else {
result = current_features;
}
}
}
return result.value_or(CpuFeatures{});
}
} // namespace oaknut
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