// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/cpu.h" #include #include #include #include #include #include #include #include #include "base/no_destructor.h" #include "build/build_config.h" #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID) || \ BUILDFLAG(IS_AIX) #include "base/containers/flat_set.h" #include "base/files/file_util.h" #include "base/format_macros.h" #include "base/notreached.h" #include "base/process/internal_linux.h" #include "base/strings/string_number_conversions.h" #include "base/strings/string_util.h" #include "base/strings/stringprintf.h" #include "base/system/sys_info.h" #include "base/threading/thread_restrictions.h" #endif #if defined(ARCH_CPU_ARM_FAMILY) && \ (BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)) #include #include #include "base/files/file_util.h" #include "base/numerics/checked_math.h" #include "base/ranges/algorithm.h" #include "base/strings/string_split.h" #include "base/strings/string_util.h" // Temporary definitions until a new hwcap.h is pulled in everywhere. // https://crbug.com/1265965 #ifndef HWCAP2_MTE #define HWCAP2_MTE (1 << 18) #define HWCAP2_BTI (1 << 17) #endif struct ProcCpuInfo { std::string brand; uint8_t implementer = 0; uint32_t part_number = 0; }; #endif #if defined(ARCH_CPU_X86_FAMILY) #if defined(COMPILER_MSVC) #include #include // For _xgetbv() #endif #endif namespace base { #if defined(ARCH_CPU_X86_FAMILY) namespace internal { X86ModelInfo ComputeX86FamilyAndModel(const std::string& vendor, int signature) { X86ModelInfo results; results.family = (signature >> 8) & 0xf; results.model = (signature >> 4) & 0xf; results.ext_family = 0; results.ext_model = 0; // The "Intel 64 and IA-32 Architectures Developer's Manual: Vol. 2A" // specifies the Extended Model is defined only when the Base Family is // 06h or 0Fh. // The "AMD CPUID Specification" specifies that the Extended Model is // defined only when Base Family is 0Fh. // Both manuals define the display model as // {ExtendedModel[3:0],BaseModel[3:0]} in that case. if (results.family == 0xf || (results.family == 0x6 && vendor == "GenuineIntel")) { results.ext_model = (signature >> 16) & 0xf; results.model += results.ext_model << 4; } // Both the "Intel 64 and IA-32 Architectures Developer's Manual: Vol. 2A" // and the "AMD CPUID Specification" specify that the Extended Family is // defined only when the Base Family is 0Fh. // Both manuals define the display family as {0000b,BaseFamily[3:0]} + // ExtendedFamily[7:0] in that case. if (results.family == 0xf) { results.ext_family = (signature >> 20) & 0xff; results.family += results.ext_family; } return results; } } // namespace internal #endif // defined(ARCH_CPU_X86_FAMILY) CPU::CPU(bool require_branding) { Initialize(require_branding); } CPU::CPU() : CPU(true) {} CPU::CPU(CPU&&) = default; namespace { #if defined(ARCH_CPU_X86_FAMILY) #if !defined(COMPILER_MSVC) #if defined(__pic__) && defined(__i386__) void __cpuid(int cpu_info[4], int info_type) { __asm__ volatile( "mov %%ebx, %%edi\n" "cpuid\n" "xchg %%edi, %%ebx\n" : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) : "a"(info_type), "c"(0)); } #else void __cpuid(int cpu_info[4], int info_type) { __asm__ volatile("cpuid\n" : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) : "a"(info_type), "c"(0)); } #endif #endif // !defined(COMPILER_MSVC) // xgetbv returns the value of an Intel Extended Control Register (XCR). // Currently only XCR0 is defined by Intel so |xcr| should always be zero. uint64_t xgetbv(uint32_t xcr) { #if defined(COMPILER_MSVC) return _xgetbv(xcr); #else uint32_t eax, edx; __asm__ volatile ( "xgetbv" : "=a"(eax), "=d"(edx) : "c"(xcr)); return (static_cast(edx) << 32) | eax; #endif // defined(COMPILER_MSVC) } #endif // ARCH_CPU_X86_FAMILY #if defined(ARCH_CPU_ARM_FAMILY) && \ (BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)) StringPairs::const_iterator FindFirstProcCpuKey(const StringPairs& pairs, StringPiece key) { return ranges::find_if(pairs, [key](const StringPairs::value_type& pair) { return TrimWhitespaceASCII(pair.first, base::TRIM_ALL) == key; }); } // Parses information about the ARM processor. Note that depending on the CPU // package, processor configuration, and/or kernel version, this may only // report information about the processor on which this thread is running. This // can happen on heterogeneous-processor SoCs like Snapdragon 808, which has 4 // Cortex-A53 and 2 Cortex-A57. Unfortunately there is not a universally // reliable way to examine the CPU part information for all cores. const ProcCpuInfo& ParseProcCpu() { static const NoDestructor info([]() { // This function finds the value from /proc/cpuinfo under the key "model // name" or "Processor". "model name" is used in Linux 3.8 and later (3.7 // and later for arm64) and is shown once per CPU. "Processor" is used in // earler versions and is shown only once at the top of /proc/cpuinfo // regardless of the number CPUs. const char kModelNamePrefix[] = "model name"; const char kProcessorPrefix[] = "Processor"; std::string cpuinfo; ReadFileToString(FilePath("/proc/cpuinfo"), &cpuinfo); DCHECK(!cpuinfo.empty()); ProcCpuInfo info; StringPairs pairs; if (!SplitStringIntoKeyValuePairs(cpuinfo, ':', '\n', &pairs)) { NOTREACHED(); return info; } auto model_name = FindFirstProcCpuKey(pairs, kModelNamePrefix); if (model_name == pairs.end()) model_name = FindFirstProcCpuKey(pairs, kProcessorPrefix); if (model_name != pairs.end()) { info.brand = std::string(TrimWhitespaceASCII(model_name->second, TRIM_ALL)); } auto implementer_string = FindFirstProcCpuKey(pairs, "CPU implementer"); if (implementer_string != pairs.end()) { // HexStringToUInt() handles the leading whitespace on the value. uint32_t implementer; HexStringToUInt(implementer_string->second, &implementer); if (!CheckedNumeric(implementer) .AssignIfValid(&info.implementer)) { info.implementer = 0; } } auto part_number_string = FindFirstProcCpuKey(pairs, "CPU part"); if (part_number_string != pairs.end()) HexStringToUInt(part_number_string->second, &info.part_number); return info; }()); return *info; } #endif // defined(ARCH_CPU_ARM_FAMILY) && (BUILDFLAG(IS_ANDROID) || // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)) } // namespace void CPU::Initialize(bool require_branding) { #if defined(ARCH_CPU_X86_FAMILY) int cpu_info[4] = {-1}; // This array is used to temporarily hold the vendor name and then the brand // name. Thus it has to be big enough for both use cases. There are // static_asserts below for each of the use cases to make sure this array is // big enough. char cpu_string[sizeof(cpu_info) * 3 + 1]; // __cpuid with an InfoType argument of 0 returns the number of // valid Ids in CPUInfo[0] and the CPU identification string in // the other three array elements. The CPU identification string is // not in linear order. The code below arranges the information // in a human readable form. The human readable order is CPUInfo[1] | // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped // before using memcpy() to copy these three array elements to |cpu_string|. __cpuid(cpu_info, 0); int num_ids = cpu_info[0]; std::swap(cpu_info[2], cpu_info[3]); static constexpr size_t kVendorNameSize = 3 * sizeof(cpu_info[1]); static_assert(kVendorNameSize < std::size(cpu_string), "cpu_string too small"); memcpy(cpu_string, &cpu_info[1], kVendorNameSize); cpu_string[kVendorNameSize] = '\0'; cpu_vendor_ = cpu_string; // Interpret CPU feature information. if (num_ids > 0) { int cpu_info7[4] = {0}; __cpuid(cpu_info, 1); if (num_ids >= 7) { __cpuid(cpu_info7, 7); } signature_ = cpu_info[0]; stepping_ = cpu_info[0] & 0xf; type_ = (cpu_info[0] >> 12) & 0x3; internal::X86ModelInfo results = internal::ComputeX86FamilyAndModel(cpu_vendor_, signature_); family_ = results.family; model_ = results.model; ext_family_ = results.ext_family; ext_model_ = results.ext_model; has_mmx_ = (cpu_info[3] & 0x00800000) != 0; has_sse_ = (cpu_info[3] & 0x02000000) != 0; has_sse2_ = (cpu_info[3] & 0x04000000) != 0; has_sse3_ = (cpu_info[2] & 0x00000001) != 0; has_ssse3_ = (cpu_info[2] & 0x00000200) != 0; has_sse41_ = (cpu_info[2] & 0x00080000) != 0; has_sse42_ = (cpu_info[2] & 0x00100000) != 0; has_popcnt_ = (cpu_info[2] & 0x00800000) != 0; // "Hypervisor Present Bit: Bit 31 of ECX of CPUID leaf 0x1." // See https://lwn.net/Articles/301888/ // This is checking for any hypervisor. Hypervisors may choose not to // announce themselves. Hypervisors trap CPUID and sometimes return // different results to underlying hardware. is_running_in_vm_ = (static_cast(cpu_info[2]) & 0x80000000) != 0; // AVX instructions will generate an illegal instruction exception unless // a) they are supported by the CPU, // b) XSAVE is supported by the CPU and // c) XSAVE is enabled by the kernel. // See http://software.intel.com/en-us/blogs/2011/04/14/is-avx-enabled // // In addition, we have observed some crashes with the xgetbv instruction // even after following Intel's example code. (See crbug.com/375968.) // Because of that, we also test the XSAVE bit because its description in // the CPUID documentation suggests that it signals xgetbv support. has_avx_ = (cpu_info[2] & 0x10000000) != 0 && (cpu_info[2] & 0x04000000) != 0 /* XSAVE */ && (cpu_info[2] & 0x08000000) != 0 /* OSXSAVE */ && (xgetbv(0) & 6) == 6 /* XSAVE enabled by kernel */; has_aesni_ = (cpu_info[2] & 0x02000000) != 0; has_fma3_ = (cpu_info[2] & 0x00001000) != 0; has_avx2_ = has_avx_ && (cpu_info7[1] & 0x00000020) != 0; } // Get the brand string of the cpu. __cpuid(cpu_info, static_cast(0x80000000)); const uint32_t max_parameter = static_cast(cpu_info[0]); static constexpr uint32_t kParameterStart = 0x80000002; static constexpr uint32_t kParameterEnd = 0x80000004; static constexpr uint32_t kParameterSize = kParameterEnd - kParameterStart + 1; static_assert(kParameterSize * sizeof(cpu_info) + 1 == std::size(cpu_string), "cpu_string has wrong size"); if (max_parameter >= kParameterEnd) { size_t i = 0; for (uint32_t parameter = kParameterStart; parameter <= kParameterEnd; ++parameter) { __cpuid(cpu_info, static_cast(parameter)); memcpy(&cpu_string[i], cpu_info, sizeof(cpu_info)); i += sizeof(cpu_info); } cpu_string[i] = '\0'; cpu_brand_ = cpu_string; } static constexpr uint32_t kParameterContainingNonStopTimeStampCounter = 0x80000007; if (max_parameter >= kParameterContainingNonStopTimeStampCounter) { __cpuid(cpu_info, static_cast(kParameterContainingNonStopTimeStampCounter)); has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0; } if (!has_non_stop_time_stamp_counter_ && is_running_in_vm_) { int cpu_info_hv[4] = {}; __cpuid(cpu_info_hv, 0x40000000); if (cpu_info_hv[1] == 0x7263694D && // Micr cpu_info_hv[2] == 0x666F736F && // osof cpu_info_hv[3] == 0x76482074) { // t Hv // If CPUID says we have a variant TSC and a hypervisor has identified // itself and the hypervisor says it is Microsoft Hyper-V, then treat // TSC as invariant. // // Microsoft Hyper-V hypervisor reports variant TSC as there are some // scenarios (eg. VM live migration) where the TSC is variant, but for // our purposes we can treat it as invariant. has_non_stop_time_stamp_counter_ = true; } } #elif defined(ARCH_CPU_ARM_FAMILY) #if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) if (require_branding) { const ProcCpuInfo& info = ParseProcCpu(); cpu_brand_ = info.brand; implementer_ = info.implementer; part_number_ = info.part_number; } #if defined(ARCH_CPU_ARM64) // Check for Armv8.5-A BTI/MTE support, exposed via HWCAP2 unsigned long hwcap2 = getauxval(AT_HWCAP2); has_mte_ = hwcap2 & HWCAP2_MTE; has_bti_ = hwcap2 & HWCAP2_BTI; #endif #elif BUILDFLAG(IS_WIN) // Windows makes high-resolution thread timing information available in // user-space. has_non_stop_time_stamp_counter_ = true; #endif #endif } #if defined(ARCH_CPU_X86_FAMILY) CPU::IntelMicroArchitecture CPU::GetIntelMicroArchitecture() const { if (has_avx2()) return AVX2; if (has_fma3()) return FMA3; if (has_avx()) return AVX; if (has_sse42()) return SSE42; if (has_sse41()) return SSE41; if (has_ssse3()) return SSSE3; if (has_sse3()) return SSE3; if (has_sse2()) return SSE2; if (has_sse()) return SSE; return PENTIUM; } #endif #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID) || \ BUILDFLAG(IS_AIX) namespace { constexpr char kTimeInStatePath[] = "/sys/devices/system/cpu/cpu%" PRIuS "/cpufreq/stats/time_in_state"; constexpr char kPhysicalPackageIdPath[] = "/sys/devices/system/cpu/cpu%" PRIuS "/topology/physical_package_id"; constexpr char kCoreIdleStateTimePath[] = "/sys/devices/system/cpu/cpu%" PRIuS "/cpuidle/state%d/time"; bool SupportsTimeInState() { // Reading from time_in_state doesn't block (it amounts to reading a struct // from the cpufreq-stats kernel driver). ThreadRestrictions::ScopedAllowIO allow_io; // Check if the time_in_state path for the first core is readable. FilePath time_in_state_path( StringPrintf(kTimeInStatePath, /*core_index=*/size_t{0})); ScopedFILE file_stream(OpenFile(time_in_state_path, "rb")); return static_cast(file_stream); } bool ParseTimeInState(const std::string& content, CPU::CoreType core_type, size_t core_index, CPU::TimeInState& time_in_state) { const char* begin = content.data(); size_t max_pos = content.size() - 1; // Example time_in_state content: // --- // 300000 1 // 403200 0 // 499200 15 // --- // Iterate over the individual lines. for (size_t pos = 0; pos <= max_pos;) { int num_chars = 0; // Each line should have two integer fields, frequency (kHz) and time (in // jiffies), separated by a space, e.g. "2419200 132". uint64_t frequency; int64_t time; int matches = sscanf(begin + pos, "%" PRIu64 " %" PRId64 "\n%n", &frequency, &time, &num_chars); if (matches != 2) return false; // Skip zero-valued entries in the output list (no time spent at this // frequency). if (time > 0) { time_in_state.push_back({core_type, core_index, frequency, internal::ClockTicksToTimeDelta(time)}); } // Advance line. DCHECK_GT(num_chars, 0); pos += static_cast(num_chars); } return true; } bool SupportsCoreIdleTimes() { // Reading from the cpuidle driver doesn't block. ThreadRestrictions::ScopedAllowIO allow_io; // Check if the path for the idle time in state 0 for core 0 is readable. FilePath idle_state0_path(StringPrintf( kCoreIdleStateTimePath, /*core_index=*/size_t{0}, /*idle_state=*/0)); ScopedFILE file_stream(OpenFile(idle_state0_path, "rb")); return static_cast(file_stream); } std::vector GuessCoreTypes() { // Try to guess the CPU architecture and cores of each cluster by comparing // the maximum frequencies of the available (online and offline) cores. const char kCPUMaxFreqPath[] = "/sys/devices/system/cpu/cpu%" PRIuS "/cpufreq/cpuinfo_max_freq"; size_t num_cpus = static_cast(SysInfo::NumberOfProcessors()); std::vector core_index_to_type(num_cpus, CPU::CoreType::kUnknown); std::vector max_core_frequencies_mhz(num_cpus, 0); flat_set frequencies_mhz; { // Reading from cpuinfo_max_freq doesn't block (it amounts to reading a // struct field from the cpufreq kernel driver). ThreadRestrictions::ScopedAllowIO allow_io; for (size_t core_index = 0; core_index < num_cpus; ++core_index) { std::string content; uint32_t frequency_khz = 0; auto path = StringPrintf(kCPUMaxFreqPath, core_index); if (ReadFileToString(FilePath(path), &content)) StringToUint(content, &frequency_khz); uint32_t frequency_mhz = frequency_khz / 1000; max_core_frequencies_mhz[core_index] = frequency_mhz; if (frequency_mhz > 0) frequencies_mhz.insert(frequency_mhz); } } size_t num_frequencies = frequencies_mhz.size(); for (size_t core_index = 0; core_index < num_cpus; ++core_index) { uint32_t core_frequency_mhz = max_core_frequencies_mhz[core_index]; CPU::CoreType core_type = CPU::CoreType::kOther; if (num_frequencies == 1u) { core_type = CPU::CoreType::kSymmetric; } else if (num_frequencies == 2u || num_frequencies == 3u) { auto it = frequencies_mhz.find(core_frequency_mhz); if (it != frequencies_mhz.end()) { // flat_set is sorted. ptrdiff_t frequency_index = it - frequencies_mhz.begin(); switch (frequency_index) { case 0: core_type = num_frequencies == 2u ? CPU::CoreType::kBigLittle_Little : CPU::CoreType::kBigLittleBigger_Little; break; case 1: core_type = num_frequencies == 2u ? CPU::CoreType::kBigLittle_Big : CPU::CoreType::kBigLittleBigger_Big; break; case 2: DCHECK_EQ(num_frequencies, 3u); core_type = CPU::CoreType::kBigLittleBigger_Bigger; break; default: NOTREACHED(); break; } } } core_index_to_type[core_index] = core_type; } return core_index_to_type; } } // namespace // static const std::vector& CPU::GetGuessedCoreTypes() { static NoDestructor> kCoreTypes(GuessCoreTypes()); return *kCoreTypes.get(); } // static bool CPU::GetTimeInState(TimeInState& time_in_state) { time_in_state.clear(); // The kernel may not support the cpufreq-stats driver. static const bool kSupportsTimeInState = SupportsTimeInState(); if (!kSupportsTimeInState) return false; static const std::vector& kCoreTypes = GetGuessedCoreTypes(); // time_in_state is reported per cluster. Identify the first cores of each // cluster. static NoDestructor> kFirstCoresIndexes([]() { std::vector first_cores; int last_core_package_id = 0; for (size_t core_index = 0; core_index < static_cast(SysInfo::NumberOfProcessors()); core_index++) { // Reading from physical_package_id doesn't block (it amounts to reading a // struct field from the kernel). ThreadRestrictions::ScopedAllowIO allow_io; FilePath package_id_path( StringPrintf(kPhysicalPackageIdPath, core_index)); std::string package_id_str; if (!ReadFileToString(package_id_path, &package_id_str)) return std::vector(); int package_id; base::StringPiece trimmed = base::TrimWhitespaceASCII( package_id_str, base::TrimPositions::TRIM_ALL); if (!base::StringToInt(trimmed, &package_id)) return std::vector(); if (last_core_package_id != package_id || core_index == 0) first_cores.push_back(core_index); last_core_package_id = package_id; } return first_cores; }()); if (kFirstCoresIndexes->empty()) return false; // Reading from time_in_state doesn't block (it amounts to reading a struct // from the cpufreq-stats kernel driver). ThreadRestrictions::ScopedAllowIO allow_io; // Read the time_in_state for each cluster from the /sys directory of the // cluster's first core. for (size_t cluster_core_index : *kFirstCoresIndexes) { FilePath time_in_state_path( StringPrintf(kTimeInStatePath, cluster_core_index)); std::string buffer; if (!ReadFileToString(time_in_state_path, &buffer)) return false; if (!ParseTimeInState(buffer, kCoreTypes[cluster_core_index], cluster_core_index, time_in_state)) { return false; } } return true; } // static bool CPU::GetCumulativeCoreIdleTimes(CoreIdleTimes& idle_times) { idle_times.clear(); // The kernel may not support the cpufreq-stats driver. static const bool kSupportsIdleTimes = SupportsCoreIdleTimes(); if (!kSupportsIdleTimes) return false; // Reading from the cpuidle driver doesn't block. ThreadRestrictions::ScopedAllowIO allow_io; size_t num_cpus = static_cast(SysInfo::NumberOfProcessors()); bool success = false; for (size_t core_index = 0; core_index < num_cpus; ++core_index) { std::string content; TimeDelta idle_time; // The number of idle states is system/CPU dependent, so we increment and // try to read each state until we fail. for (int state_index = 0;; ++state_index) { auto path = StringPrintf(kCoreIdleStateTimePath, core_index, state_index); uint64_t idle_state_time = 0; if (!ReadFileToString(FilePath(path), &content)) break; StringToUint64(content, &idle_state_time); idle_time += Microseconds(idle_state_time); } idle_times.push_back(idle_time); // At least one of the cores should have some idle time, otherwise we report // a failure. success |= idle_time.is_positive(); } return success; } #endif // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || // BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_AIX) const CPU& CPU::GetInstanceNoAllocation() { static const base::NoDestructor cpu(CPU(false)); return *cpu; } } // namespace base