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Diffstat (limited to 'src/common/cpuinfo/CpuInfo.cpp')
-rw-r--r-- | src/common/cpuinfo/CpuInfo.cpp | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/src/common/cpuinfo/CpuInfo.cpp b/src/common/cpuinfo/CpuInfo.cpp new file mode 100644 index 0000000000..436e7ea803 --- /dev/null +++ b/src/common/cpuinfo/CpuInfo.cpp @@ -0,0 +1,405 @@ +/* + * Copyright (c) 2021 Arm Limited. + * + * SPDX-License-Identifier: MIT + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#include "src/common/cpuinfo/CpuInfo.h" + +#include "arm_compute/core/Error.h" +#include "arm_compute/core/Log.h" +#include "src/common/cpuinfo/target/CpuInfoSveUtils.h" +#include "support/StringSupport.h" +#include "support/ToolchainSupport.h" + +#include <sstream> + +#if !defined(BARE_METAL) +#include <algorithm> +#include <cstring> +#include <fstream> +#include <regex.h> /* C++ std::regex takes up a lot of space in the standalone builds */ +#include <sched.h> +#include <thread> +#include <unordered_map> +#endif /* !defined(BARE_METAL) */ + +#if !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) +#include <asm/hwcap.h> /* Get HWCAP bits from asm/hwcap.h */ +#include <sys/auxv.h> +#endif /* !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) */ + +#define ARM_COMPUTE_CPU_FEATURE_HWCAP_CPUID (1 << 11) +#define ARM_COMPUTE_GET_FEATURE_REG(var, freg) __asm __volatile("MRS %0, " #freg \ + : "=r"(var)) +namespace arm_compute +{ +namespace cpuinfo +{ +namespace +{ +#if !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) +/** Extract MIDR using CPUID information that are exposed to user-space + * + * @param[in] max_num_cpus Maximum number of possible CPUs + * + * @return std::vector<uint32_t> A list of the MIDR of each core + */ +std::vector<uint32_t> midr_from_cpuid(uint32_t max_num_cpus) +{ + std::vector<uint32_t> cpus; + for(unsigned int i = 0; i < max_num_cpus; ++i) + { + std::stringstream str; + str << "/sys/devices/system/cpu/cpu" << i << "/regs/identification/midr_el1"; + std::ifstream file(str.str(), std::ios::in); + if(file.is_open()) + { + std::string line; + if(bool(getline(file, line))) + { + cpus.emplace_back(support::cpp11::stoul(line, nullptr, support::cpp11::NumericBase::BASE_16)); + } + } + } + return cpus; +} + +/** Extract MIDR by parsing the /proc/cpuinfo meta-data + * + * @param[in] max_num_cpus Maximum number of possible CPUs + * + * @return std::vector<uint32_t> A list of the MIDR of each core + */ +std::vector<uint32_t> midr_from_proc_cpuinfo(int max_num_cpus) +{ + std::vector<uint32_t> cpus; + + regex_t proc_regex; + regex_t imp_regex; + regex_t var_regex; + regex_t part_regex; + regex_t rev_regex; + + memset(&proc_regex, 0, sizeof(regex_t)); + memset(&imp_regex, 0, sizeof(regex_t)); + memset(&var_regex, 0, sizeof(regex_t)); + memset(&part_regex, 0, sizeof(regex_t)); + memset(&rev_regex, 0, sizeof(regex_t)); + + int ret_status = 0; + // If "long-form" cpuinfo is present, parse that to populate models. + ret_status |= regcomp(&proc_regex, R"(^processor.*([[:digit:]]+)$)", REG_EXTENDED); + ret_status |= regcomp(&imp_regex, R"(^CPU implementer.*0x(..)$)", REG_EXTENDED); + ret_status |= regcomp(&var_regex, R"(^CPU variant.*0x(.)$)", REG_EXTENDED); + ret_status |= regcomp(&part_regex, R"(^CPU part.*0x(...)$)", REG_EXTENDED); + ret_status |= regcomp(&rev_regex, R"(^CPU revision.*([[:digit:]]+)$)", REG_EXTENDED); + ARM_COMPUTE_UNUSED(ret_status); + ARM_COMPUTE_ERROR_ON_MSG(ret_status != 0, "Regex compilation failed."); + + std::ifstream file("/proc/cpuinfo", std::ios::in); + if(file.is_open()) + { + std::string line; + int midr = 0; + int curcpu = -1; + + while(bool(getline(file, line))) + { + std::array<regmatch_t, 2> match; + ret_status = regexec(&proc_regex, line.c_str(), 2, match.data(), 0); + if(ret_status == 0) + { + std::string id = line.substr(match[1].rm_so, (match[1].rm_eo - match[1].rm_so)); + int newcpu = support::cpp11::stoi(id, nullptr); + + if(curcpu >= 0 && midr == 0) + { + // Matched a new CPU ID without any description of the previous one - looks like old format. + return {}; + } + + if(curcpu >= 0 && curcpu < max_num_cpus) + { + cpus.emplace_back(midr); + } + else + { + ARM_COMPUTE_LOG_INFO_MSG_CORE("Trying to populate a core id with id greater than the expected number of cores!"); + } + + midr = 0; + curcpu = newcpu; + + continue; + } + + ret_status = regexec(&imp_regex, line.c_str(), 2, match.data(), 0); + if(ret_status == 0) + { + std::string subexp = line.substr(match[1].rm_so, (match[1].rm_eo - match[1].rm_so)); + int impv = support::cpp11::stoi(subexp, nullptr, support::cpp11::NumericBase::BASE_16); + midr |= (impv << 24); + + continue; + } + + ret_status = regexec(&var_regex, line.c_str(), 2, match.data(), 0); + if(ret_status == 0) + { + std::string subexp = line.substr(match[1].rm_so, (match[1].rm_eo - match[1].rm_so)); + int varv = support::cpp11::stoi(subexp, nullptr, support::cpp11::NumericBase::BASE_16); + midr |= (varv << 20); + + continue; + } + + ret_status = regexec(&part_regex, line.c_str(), 2, match.data(), 0); + if(ret_status == 0) + { + std::string subexp = line.substr(match[1].rm_so, (match[1].rm_eo - match[1].rm_so)); + int partv = support::cpp11::stoi(subexp, nullptr, support::cpp11::NumericBase::BASE_16); + midr |= (partv << 4); + + continue; + } + + ret_status = regexec(&rev_regex, line.c_str(), 2, match.data(), 0); + if(ret_status == 0) + { + std::string subexp = line.substr(match[1].rm_so, (match[1].rm_eo - match[1].rm_so)); + int regv = support::cpp11::stoi(subexp, nullptr); + midr |= (regv); + midr |= (0xf << 16); + + continue; + } + } + + if(curcpu >= 0 && curcpu < max_num_cpus) + { + cpus.emplace_back(midr); + } + else + { + ARM_COMPUTE_LOG_INFO_MSG_CORE("Trying to populate a core id with id greater than the expected number of cores!"); + } + } + + // Free allocated memory + regfree(&proc_regex); + regfree(&imp_regex); + regfree(&var_regex); + regfree(&part_regex); + regfree(&rev_regex); + + return cpus; +} + +/** Get the maximim number of CPUs in the system by parsing /sys/devices/system/cpu/present + * + * @return int Maximum number of CPUs + */ +int get_max_cpus() +{ + int max_cpus = 1; + std::ifstream CPUspresent; + CPUspresent.open("/sys/devices/system/cpu/present", std::ios::in); + bool success = false; + + if(CPUspresent.is_open()) + { + std::string line; + + if(bool(getline(CPUspresent, line))) + { + /* The content of this file is a list of ranges or single values, e.g. + * 0-5, or 1-3,5,7 or similar. As we are interested in the + * max valid ID, we just need to find the last valid + * delimiter ('-' or ',') and parse the integer immediately after that. + */ + auto startfrom = line.begin(); + + for(auto i = line.begin(); i < line.end(); ++i) + { + if(*i == '-' || *i == ',') + { + startfrom = i + 1; + } + } + + line.erase(line.begin(), startfrom); + + max_cpus = support::cpp11::stoi(line, nullptr) + 1; + success = true; + } + } + + // Return std::thread::hardware_concurrency() as a fallback. + if(!success) + { + max_cpus = std::thread::hardware_concurrency(); + } + return max_cpus; +} +#endif /* !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) */ +} // namespace + +CpuInfo::CpuInfo(CpuIsaInfo isa, std::vector<CpuModel> cpus) + : _isa(std::move(isa)), _cpus(std::move(cpus)) +{ +} + +CpuInfo CpuInfo::build() +{ +#if !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) + const uint32_t hwcaps = getauxval(AT_HWCAP); + const uint32_t hwcaps2 = getauxval(AT_HWCAP2); + const uint32_t max_cpus = get_max_cpus(); + + // Populate midr values + std::vector<uint32_t> cpus_midr; + if(hwcaps & ARM_COMPUTE_CPU_FEATURE_HWCAP_CPUID) + { + cpus_midr = midr_from_cpuid(max_cpus); + } + if(cpus_midr.empty()) + { + cpus_midr = midr_from_proc_cpuinfo(max_cpus); + } + if(cpus_midr.empty()) + { + cpus_midr.resize(max_cpus, 0); + } + + // Populate isa (Assume homogeneous ISA specification) + CpuIsaInfo isa = init_cpu_isa_from_hwcaps(hwcaps, hwcaps2, cpus_midr.back()); + + // Convert midr to models + std::vector<CpuModel> cpus_model; + std::transform(std::begin(cpus_midr), std::end(cpus_midr), std::back_inserter(cpus_model), + [](uint32_t midr) -> CpuModel { return midr_to_model(midr); }); + + CpuInfo info(isa, cpus_model); + return info; + +#elif(BARE_METAL) && defined(__aarch64__) /* !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) */ + + // Assume single CPU in bare metal mode. Just read the ID register and feature bits directly. + uint64_t isar0 = 0, isar1 = 0, pfr0 = 0, svefr0 = 0, midr = 0; + ARM_COMPUTE_GET_FEATURE_REG(isar0, ID_AA64ISAR0_EL1); + ARM_COMPUTE_GET_FEATURE_REG(isar1, ID_AA64ISAR1_EL1); + ARM_COMPUTE_GET_FEATURE_REG(pfr0, ID_AA64PFR0_EL1); + ARM_COMPUTE_GET_FEATURE_REG(midr, MIDR_EL1); + if((pfr0 >> 32) & 0xf) + { + svefr0 = get_sve_feature_reg(); + } + + CpuIsaInfo isa = init_cpu_isa_from_regs(isar0, isar1, pfr0, svefr0, midr); + std::vector<CpuModel> cpus_model(1, midr_to_model(midr)); + CpuInfo info(isa, cpus_model); + return info; +#else /* #elif(BARE_METAL) && defined(__aarch64__) */ + CpuInfo info(CpuIsaInfo(), { CpuModel::GENERIC }); + return info; +#endif /* !defined(BARE_METAL) && !defined(__APPLE__) && (defined(__arm__) || defined(__aarch64__)) */ +} + +CpuModel CpuInfo::cpu_model(uint32_t cpuid) const +{ + if(cpuid < _cpus.size()) + { + return _cpus[cpuid]; + } + return CpuModel::GENERIC; +} + +CpuModel CpuInfo::cpu_model() const +{ +#if defined(BARE_METAL) || defined(__APPLE__) || (!defined(__arm__) && !defined(__aarch64__)) + return cpu_model(0); +#else /* defined(BARE_METAL) || defined(__APPLE__) || (!defined(__arm__) && !defined(__aarch64__)) */ + return cpu_model(sched_getcpu()); +#endif /* defined(BARE_METAL) || defined(__APPLE__) || (!defined(__arm__) && !defined(__aarch64__)) */ +} + +uint32_t CpuInfo::num_cpus() const +{ + return _cpus.size(); +} + +uint32_t num_threads_hint() +{ + unsigned int num_threads_hint = 1; + +#if !defined(BARE_METAL) + std::vector<std::string> cpus; + cpus.reserve(64); + + // CPU part regex + regex_t cpu_part_rgx; + memset(&cpu_part_rgx, 0, sizeof(regex_t)); + int ret_status = regcomp(&cpu_part_rgx, R"(.*CPU part.+/?\:[[:space:]]+([[:alnum:]]+).*)", REG_EXTENDED); + ARM_COMPUTE_UNUSED(ret_status); + ARM_COMPUTE_ERROR_ON_MSG(ret_status != 0, "Regex compilation failed."); + + // Read cpuinfo and get occurrence of each core + std::ifstream cpuinfo_file("/proc/cpuinfo", std::ios::in); + if(cpuinfo_file.is_open()) + { + std::string line; + while(bool(getline(cpuinfo_file, line))) + { + std::array<regmatch_t, 2> match; + if(regexec(&cpu_part_rgx, line.c_str(), 2, match.data(), 0) == 0) + { + cpus.emplace_back(line.substr(match[1].rm_so, (match[1].rm_eo - match[1].rm_so))); + } + } + } + regfree(&cpu_part_rgx); + + // Get min number of threads + std::sort(std::begin(cpus), std::end(cpus)); + auto least_frequent_cpu_occurences = [](const std::vector<std::string> &cpus) -> uint32_t + { + std::unordered_map<std::string, uint32_t> cpus_freq; + for(const auto &cpu : cpus) + { + cpus_freq[cpu]++; + } + + uint32_t vmin = cpus.size() + 1; + for(const auto &cpu_freq : cpus_freq) + { + vmin = std::min(vmin, cpu_freq.second); + } + return vmin; + }; + + // Set thread hint + num_threads_hint = cpus.empty() ? std::thread::hardware_concurrency() : least_frequent_cpu_occurences(cpus); +#endif /* !defined(BARE_METAL) */ + + return num_threads_hint; +} +} // namespace cpuinfo +} // namespace arm_compute
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