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 defined(__hexagon__) || defined(__loongarch_lp64) || defined(__riscv)
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
64namespace __xray {
65
66inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
67
68ALWAYS_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
80inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT {
81 return NanosecondsPerSecond;
82}
83
84} // namespace __xray
85
86#elif defined(__s390x__)
87#include "sanitizer_common/sanitizer_common.h"
88#include "sanitizer_common/sanitizer_internal_defs.h"
89#include "xray_defs.h"
90#include <cerrno>
91#include <cstdint>
92#include <time.h>
93
94namespace __xray {
95
96inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
97
98ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
99 CPU = 0;
100#if __has_builtin(__builtin_readcyclecounter)
101 return __builtin_readcyclecounter();
102#else
103 uint64_t Cycles;
104 asm volatile("stckf %0" : : "Q"(Cycles) : "cc");
105 return Cycles;
106#endif
107}
108
109inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT {
110 return NanosecondsPerSecond;
111}
112
113} // namespace __xray
114
115#else
116#error Target architecture is not supported.
117#endif // CPU architecture
118#endif // SANITIZER_FUCHSIA
119
120#endif // XRAY_EMULATE_TSC_H
121