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