1// Copyright 2017 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build arm64
6
7package cpu
8
9const CacheLineSize = 64
10
11// arm64 doesn't have a 'cpuid' equivalent, so we rely on HWCAP/HWCAP2.
12// These are linknamed in runtime/os_linux_arm64.go and are initialized by
13// archauxv().
14var arm64_hwcap uint
15var arm64_hwcap2 uint
16
17// HWCAP/HWCAP2 bits. These are exposed by Linux.
18const (
19	_ARM64_FEATURE_HAS_FP      = (1 << 0)
20	_ARM64_FEATURE_HAS_ASIMD   = (1 << 1)
21	_ARM64_FEATURE_HAS_EVTSTRM = (1 << 2)
22	_ARM64_FEATURE_HAS_AES     = (1 << 3)
23	_ARM64_FEATURE_HAS_PMULL   = (1 << 4)
24	_ARM64_FEATURE_HAS_SHA1    = (1 << 5)
25	_ARM64_FEATURE_HAS_SHA2    = (1 << 6)
26	_ARM64_FEATURE_HAS_CRC32   = (1 << 7)
27	_ARM64_FEATURE_HAS_ATOMICS = (1 << 8)
28)
29
30func init() {
31	// HWCAP feature bits
32	ARM64.HasFP = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_FP)
33	ARM64.HasASIMD = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_ASIMD)
34	ARM64.HasEVTSTRM = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_EVTSTRM)
35	ARM64.HasAES = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_AES)
36	ARM64.HasPMULL = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_PMULL)
37	ARM64.HasSHA1 = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_SHA1)
38	ARM64.HasSHA2 = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_SHA2)
39	ARM64.HasCRC32 = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_CRC32)
40	ARM64.HasATOMICS = isSet(arm64_hwcap, _ARM64_FEATURE_HAS_ATOMICS)
41}
42
43func isSet(hwc uint, value uint) bool {
44	return hwc&value != 0
45}
46