From c990c680b611ac1aeb7d8f2af94a825f98d69720 Mon Sep 17 00:00:00 2001 From: John Papandriopoulos Date: Thu, 26 Sep 2019 11:47:27 -0700 Subject: [PATCH] cpu: support ARM feature detection on Linux MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Updates golang/go#33508 Change-Id: I9ea01090f5b4ac95c1a14881c305461bd4a7b5dd Reviewed-on: https://go-review.googlesource.com/c/sys/+/190525 Run-TryBot: Tobias Klauser TryBot-Result: Gobot Gobot Reviewed-by: Tobias Klauser Reviewed-by: Martin Möhrmann --- cpu/cpu.go | 36 ++++++++++++++++++++++++++++++++++++ cpu/cpu_arm.go | 33 ++++++++++++++++++++++++++++++++- cpu/cpu_linux_arm.go | 39 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 107 insertions(+), 1 deletion(-) create mode 100644 cpu/cpu_linux_arm.go diff --git a/cpu/cpu.go b/cpu/cpu.go index 679e78c2..b4e6ecb2 100644 --- a/cpu/cpu.go +++ b/cpu/cpu.go @@ -78,6 +78,42 @@ var ARM64 struct { _ CacheLinePad } +// ARM contains the supported CPU features of the current ARM (32-bit) platform. +// All feature flags are false if: +// 1. the current platform is not arm, or +// 2. the current operating system is not Linux. +var ARM struct { + _ CacheLinePad + HasSWP bool // SWP instruction support + HasHALF bool // Half-word load and store support + HasTHUMB bool // ARM Thumb instruction set + Has26BIT bool // Address space limited to 26-bits + HasFASTMUL bool // 32-bit operand, 64-bit result multiplication support + HasFPA bool // Floating point arithmetic support + HasVFP bool // Vector floating point support + HasEDSP bool // DSP Extensions support + HasJAVA bool // Java instruction set + HasIWMMXT bool // Intel Wireless MMX technology support + HasCRUNCH bool // MaverickCrunch context switching and handling + HasTHUMBEE bool // Thumb EE instruction set + HasNEON bool // NEON instruction set + HasVFPv3 bool // Vector floating point version 3 support + HasVFPv3D16 bool // Vector floating point version 3 D8-D15 + HasTLS bool // Thread local storage support + HasVFPv4 bool // Vector floating point version 4 support + HasIDIVA bool // Integer divide instruction support in ARM mode + HasIDIVT bool // Integer divide instruction support in Thumb mode + HasVFPD32 bool // Vector floating point version 3 D15-D31 + HasLPAE bool // Large Physical Address Extensions + HasEVTSTRM bool // Event stream support + HasAES bool // AES hardware implementation + HasPMULL bool // Polynomial multiplication instruction set + HasSHA1 bool // SHA1 hardware implementation + HasSHA2 bool // SHA2 hardware implementation + HasCRC32 bool // CRC32 hardware implementation + _ CacheLinePad +} + // PPC64 contains the supported CPU features of the current ppc64/ppc64le platforms. // If the current platform is not ppc64/ppc64le then all feature flags are false. // diff --git a/cpu/cpu_arm.go b/cpu/cpu_arm.go index 7f2348b7..981af681 100644 --- a/cpu/cpu_arm.go +++ b/cpu/cpu_arm.go @@ -6,4 +6,35 @@ package cpu const cacheLineSize = 32 -func doinit() {} +// HWCAP/HWCAP2 bits. +// These are specific to Linux. +const ( + hwcap_SWP = 1 << 0 + hwcap_HALF = 1 << 1 + hwcap_THUMB = 1 << 2 + hwcap_26BIT = 1 << 3 + hwcap_FAST_MULT = 1 << 4 + hwcap_FPA = 1 << 5 + hwcap_VFP = 1 << 6 + hwcap_EDSP = 1 << 7 + hwcap_JAVA = 1 << 8 + hwcap_IWMMXT = 1 << 9 + hwcap_CRUNCH = 1 << 10 + hwcap_THUMBEE = 1 << 11 + hwcap_NEON = 1 << 12 + hwcap_VFPv3 = 1 << 13 + hwcap_VFPv3D16 = 1 << 14 + hwcap_TLS = 1 << 15 + hwcap_VFPv4 = 1 << 16 + hwcap_IDIVA = 1 << 17 + hwcap_IDIVT = 1 << 18 + hwcap_VFPD32 = 1 << 19 + hwcap_LPAE = 1 << 20 + hwcap_EVTSTRM = 1 << 21 + + hwcap2_AES = 1 << 0 + hwcap2_PMULL = 1 << 1 + hwcap2_SHA1 = 1 << 2 + hwcap2_SHA2 = 1 << 3 + hwcap2_CRC32 = 1 << 4 +) diff --git a/cpu/cpu_linux_arm.go b/cpu/cpu_linux_arm.go new file mode 100644 index 00000000..2057006d --- /dev/null +++ b/cpu/cpu_linux_arm.go @@ -0,0 +1,39 @@ +// Copyright 2019 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 + +func doinit() { + ARM.HasSWP = isSet(hwCap, hwcap_SWP) + ARM.HasHALF = isSet(hwCap, hwcap_HALF) + ARM.HasTHUMB = isSet(hwCap, hwcap_THUMB) + ARM.Has26BIT = isSet(hwCap, hwcap_26BIT) + ARM.HasFASTMUL = isSet(hwCap, hwcap_FAST_MULT) + ARM.HasFPA = isSet(hwCap, hwcap_FPA) + ARM.HasVFP = isSet(hwCap, hwcap_VFP) + ARM.HasEDSP = isSet(hwCap, hwcap_EDSP) + ARM.HasJAVA = isSet(hwCap, hwcap_JAVA) + ARM.HasIWMMXT = isSet(hwCap, hwcap_IWMMXT) + ARM.HasCRUNCH = isSet(hwCap, hwcap_CRUNCH) + ARM.HasTHUMBEE = isSet(hwCap, hwcap_THUMBEE) + ARM.HasNEON = isSet(hwCap, hwcap_NEON) + ARM.HasVFPv3 = isSet(hwCap, hwcap_VFPv3) + ARM.HasVFPv3D16 = isSet(hwCap, hwcap_VFPv3D16) + ARM.HasTLS = isSet(hwCap, hwcap_TLS) + ARM.HasVFPv4 = isSet(hwCap, hwcap_VFPv4) + ARM.HasIDIVA = isSet(hwCap, hwcap_IDIVA) + ARM.HasIDIVT = isSet(hwCap, hwcap_IDIVT) + ARM.HasVFPD32 = isSet(hwCap, hwcap_VFPD32) + ARM.HasLPAE = isSet(hwCap, hwcap_LPAE) + ARM.HasEVTSTRM = isSet(hwCap, hwcap_EVTSTRM) + ARM.HasAES = isSet(hwCap2, hwcap2_AES) + ARM.HasPMULL = isSet(hwCap2, hwcap2_PMULL) + ARM.HasSHA1 = isSet(hwCap2, hwcap2_SHA1) + ARM.HasSHA2 = isSet(hwCap2, hwcap2_SHA2) + ARM.HasCRC32 = isSet(hwCap2, hwcap2_CRC32) +} + +func isSet(hwc uint, value uint) bool { + return hwc&value != 0 +}