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
probeRequiredCPUFeatures()26 inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
27
readTSC(uint8_t & CPU)28 ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
29 CPU = 0;
30 return _zx_ticks_get();
31 }
32
getTSCFrequency()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 // 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
63 namespace __xray {
64
probeRequiredCPUFeatures()65 inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
66
readTSC(uint8_t & CPU)67 ALWAYS_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
getTSCFrequency()79 inline 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