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 17 namespace __xray { 18 static constexpr uint64_t NanosecondsPerSecond = 1000ULL * 1000 * 1000; 19 } 20 21 #if SANITIZER_FUCHSIA 22 #include <zircon/syscalls.h> 23 24 namespace __xray { 25 26 inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } 27 28 ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT { 29 CPU = 0; 30 return _zx_ticks_get(); 31 } 32 33 inline 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 defined(__hexagon__) 47 // Emulated TSC. 48 // There is no instruction like RDTSCP in user mode on ARM. ARM's CP15 does 49 // not have a constant frequency like TSC on x86(_64), it may go faster 50 // or slower depending on CPU turbo or power saving mode. Furthermore, 51 // to read from CP15 on ARM a kernel modification or a driver is needed. 52 // We can not require this from users of compiler-rt. 53 // So on ARM we use clock_gettime() which gives the result in nanoseconds. 54 // To get the measurements per second, we scale this by the number of 55 // nanoseconds per second, pretending that the TSC frequency is 1GHz and 56 // one TSC tick is 1 nanosecond. 57 #include "sanitizer_common/sanitizer_common.h" 58 #include "sanitizer_common/sanitizer_internal_defs.h" 59 #include "xray_defs.h" 60 #include <cerrno> 61 #include <cstdint> 62 #include <time.h> 63 64 namespace __xray { 65 66 inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } 67 68 ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT { 69 timespec TS; 70 int result = clock_gettime(CLOCK_REALTIME, &TS); 71 if (result != 0) { 72 Report("clock_gettime(2) returned %d, errno=%d.", result, int(errno)); 73 TS.tv_sec = 0; 74 TS.tv_nsec = 0; 75 } 76 CPU = 0; 77 return TS.tv_sec * NanosecondsPerSecond + TS.tv_nsec; 78 } 79 80 inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT { 81 return NanosecondsPerSecond; 82 } 83 84 } // namespace __xray 85 86 #else 87 #error Target architecture is not supported. 88 #endif // CPU architecture 89 #endif // SANITIZER_FUCHSIA 90 91 #endif // XRAY_EMULATE_TSC_H 92