1//===-- xray_tsc.h ----------------------------------------------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file is a part of XRay, a dynamic runtime instrumentation system. 10// 11//===----------------------------------------------------------------------===// 12#ifndef XRAY_EMULATE_TSC_H 13#define XRAY_EMULATE_TSC_H 14 15#include "sanitizer_common/sanitizer_common.h" 16 17namespace __xray { 18static constexpr uint64_t NanosecondsPerSecond = 1000ULL * 1000 * 1000; 19} 20 21#if SANITIZER_FUCHSIA 22#include <zircon/syscalls.h> 23 24namespace __xray { 25 26inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } 27 28ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT { 29 CPU = 0; 30 return _zx_ticks_get(); 31} 32 33inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT { 34 return _zx_ticks_per_second(); 35} 36 37} // namespace __xray 38 39#else // SANITIZER_FUCHSIA 40 41#if defined(__x86_64__) 42#include "xray_x86_64.inc" 43#elif defined(__powerpc64__) 44#include "xray_powerpc64.inc" 45#elif defined(__arm__) || defined(__aarch64__) || defined(__mips__) 46// Emulated TSC. 47// There is no instruction like RDTSCP in user mode on ARM. ARM's CP15 does 48// not have a constant frequency like TSC on x86(_64), it may go faster 49// or slower depending on CPU turbo or power saving mode. Furthermore, 50// to read from CP15 on ARM a kernel modification or a driver is needed. 51// We can not require this from users of compiler-rt. 52// So on ARM we use clock_gettime() which gives the result in nanoseconds. 53// To get the measurements per second, we scale this by the number of 54// nanoseconds per second, pretending that the TSC frequency is 1GHz and 55// one TSC tick is 1 nanosecond. 56#include "sanitizer_common/sanitizer_common.h" 57#include "sanitizer_common/sanitizer_internal_defs.h" 58#include "xray_defs.h" 59#include <cerrno> 60#include <cstdint> 61#include <time.h> 62 63namespace __xray { 64 65inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } 66 67ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT { 68 timespec TS; 69 int result = clock_gettime(CLOCK_REALTIME, &TS); 70 if (result != 0) { 71 Report("clock_gettime(2) returned %d, errno=%d.", result, int(errno)); 72 TS.tv_sec = 0; 73 TS.tv_nsec = 0; 74 } 75 CPU = 0; 76 return TS.tv_sec * NanosecondsPerSecond + TS.tv_nsec; 77} 78 79inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT { 80 return NanosecondsPerSecond; 81} 82 83} // namespace __xray 84 85#else 86#error Target architecture is not supported. 87#endif // CPU architecture 88#endif // SANITIZER_FUCHSIA 89 90#endif // XRAY_EMULATE_TSC_H 91