1 files changed, 111 insertions, 0 deletions

diff --git a/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
new file mode 100644
index 0000000..a968b80
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
@@ -0,0 +1,111 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpu
+
+import (
+        "strings"
+        "syscall"
+)
+
+// HWCAP/HWCAP2 bits. These are exposed by Linux.
+const (
+        hwcap_FP       = 1 << 0
+        hwcap_ASIMD    = 1 << 1
+        hwcap_EVTSTRM  = 1 << 2
+        hwcap_AES      = 1 << 3
+        hwcap_PMULL    = 1 << 4
+        hwcap_SHA1     = 1 << 5
+        hwcap_SHA2     = 1 << 6
+        hwcap_CRC32    = 1 << 7
+        hwcap_ATOMICS  = 1 << 8
+        hwcap_FPHP     = 1 << 9
+        hwcap_ASIMDHP  = 1 << 10
+        hwcap_CPUID    = 1 << 11
+        hwcap_ASIMDRDM = 1 << 12
+        hwcap_JSCVT    = 1 << 13
+        hwcap_FCMA     = 1 << 14
+        hwcap_LRCPC    = 1 << 15
+        hwcap_DCPOP    = 1 << 16
+        hwcap_SHA3     = 1 << 17
+        hwcap_SM3      = 1 << 18
+        hwcap_SM4      = 1 << 19
+        hwcap_ASIMDDP  = 1 << 20
+        hwcap_SHA512   = 1 << 21
+        hwcap_SVE      = 1 << 22
+        hwcap_ASIMDFHM = 1 << 23
+)
+
+// linuxKernelCanEmulateCPUID reports whether we're running
+// on Linux 4.11+. Ideally we'd like to ask the question about
+// whether the current kernel contains
+// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=77c97b4ee21290f5f083173d957843b615abbff2
+// but the version number will have to do.
+func linuxKernelCanEmulateCPUID() bool {
+        var un syscall.Utsname
+        syscall.Uname(&un)
+        var sb strings.Builder
+        for _, b := range un.Release[:] {
+                if b == 0 {
+                        break
+                }
+                sb.WriteByte(byte(b))
+        }
+        major, minor, _, ok := parseRelease(sb.String())
+        return ok && (major > 4 || major == 4 && minor >= 11)
+}
+
+func doinit() {
+        if err := readHWCAP(); err != nil {
+                // We failed to read /proc/self/auxv. This can happen if the binary has
+                // been given extra capabilities(7) with /bin/setcap.
+                //
+                // When this happens, we have two options. If the Linux kernel is new
+                // enough (4.11+), we can read the arm64 registers directly which'll
+                // trap into the kernel and then return back to userspace.
+                //
+                // But on older kernels, such as Linux 4.4.180 as used on many Synology
+                // devices, calling readARM64Registers (specifically getisar0) will
+                // cause a SIGILL and we'll die. So for older kernels, parse /proc/cpuinfo
+                // instead.
+                //
+                // See golang/go#57336.
+                if linuxKernelCanEmulateCPUID() {
+                        readARM64Registers()
+                } else {
+                        readLinuxProcCPUInfo()
+                }
+                return
+        }
+
+        // HWCAP feature bits
+        ARM64.HasFP = isSet(hwCap, hwcap_FP)
+        ARM64.HasASIMD = isSet(hwCap, hwcap_ASIMD)
+        ARM64.HasEVTSTRM = isSet(hwCap, hwcap_EVTSTRM)
+        ARM64.HasAES = isSet(hwCap, hwcap_AES)
+        ARM64.HasPMULL = isSet(hwCap, hwcap_PMULL)
+        ARM64.HasSHA1 = isSet(hwCap, hwcap_SHA1)
+        ARM64.HasSHA2 = isSet(hwCap, hwcap_SHA2)
+        ARM64.HasCRC32 = isSet(hwCap, hwcap_CRC32)
+        ARM64.HasATOMICS = isSet(hwCap, hwcap_ATOMICS)
+        ARM64.HasFPHP = isSet(hwCap, hwcap_FPHP)
+        ARM64.HasASIMDHP = isSet(hwCap, hwcap_ASIMDHP)
+        ARM64.HasCPUID = isSet(hwCap, hwcap_CPUID)
+        ARM64.HasASIMDRDM = isSet(hwCap, hwcap_ASIMDRDM)
+        ARM64.HasJSCVT = isSet(hwCap, hwcap_JSCVT)
+        ARM64.HasFCMA = isSet(hwCap, hwcap_FCMA)
+        ARM64.HasLRCPC = isSet(hwCap, hwcap_LRCPC)
+        ARM64.HasDCPOP = isSet(hwCap, hwcap_DCPOP)
+        ARM64.HasSHA3 = isSet(hwCap, hwcap_SHA3)
+        ARM64.HasSM3 = isSet(hwCap, hwcap_SM3)
+        ARM64.HasSM4 = isSet(hwCap, hwcap_SM4)
+        ARM64.HasASIMDDP = isSet(hwCap, hwcap_ASIMDDP)
+        ARM64.HasSHA512 = isSet(hwCap, hwcap_SHA512)
+        ARM64.HasSVE = isSet(hwCap, hwcap_SVE)
+        ARM64.HasASIMDFHM = isSet(hwCap, hwcap_ASIMDFHM)
+}
+
+func isSet(hwc uint, value uint) bool {
+        return hwc&value != 0
+}