1/*
2 * Copyright (C) 2019 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "CPU.h"
28
29#if (CPU(X86) || CPU(X86_64)) && OS(DARWIN)
30#include <mutex>
31#include <sys/sysctl.h>
32#endif
33
34namespace JSC {
35
36#if (CPU(X86) || CPU(X86_64)) && OS(DARWIN)
37bool isKernTCSMAvailable()
38{
39 uint32_t val = 0;
40 size_t valSize = sizeof(val);
41 int rc = sysctlbyname("kern.tcsm_available", &val, &valSize, NULL, 0);
42 if (rc < 0)
43 return false;
44 return !!val;
45}
46
47bool enableKernTCSM()
48{
49 uint32_t val = 1;
50 int rc = sysctlbyname("kern.tcsm_enable", NULL, 0, &val, sizeof(val));
51 if (rc < 0)
52 return false;
53 return true;
54}
55
56int kernTCSMAwareNumberOfProcessorCores()
57{
58 static std::once_flag onceFlag;
59 static int result;
60 std::call_once(onceFlag, [] {
61 result = WTF::numberOfProcessorCores();
62 if (result <= 1)
63 return;
64 if (isKernTCSMAvailable())
65 --result;
66 });
67 return result;
68}
69#endif // #if (CPU(X86) || CPU(X86_64)) && OS(DARWIN)
70
71} // namespace JSC
72