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708e7fb298
This adds feature detection that works on the s390x running zos. There are some differences with Linux (no hwcap, facilities vector available in-memory). These changes should not affect other platforms. Fixes golang/go#41984. Change-Id: Ieabbfafd07367a346a4d279dde0f00aa3fc4321b Reviewed-on: https://go-review.googlesource.com/c/sys/+/262477 Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Martin Möhrmann <moehrmann@google.com> Trust: Martin Möhrmann <moehrmann@google.com> Trust: Emmanuel Odeke <emmanuel@orijtech.com>
76 lines
1.9 KiB
Go
76 lines
1.9 KiB
Go
// Copyright 2020 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package cpu_test
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import (
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"runtime"
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"testing"
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"unsafe"
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"golang.org/x/sys/cpu"
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)
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var s390xTests = []struct {
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name string
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feature bool
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facility uint
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mandatory bool
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}{
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{"ZARCH", cpu.S390X.HasZARCH, 1, true},
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{"STFLE", cpu.S390X.HasSTFLE, 7, true},
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{"LDISP", cpu.S390X.HasLDISP, 18, true},
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{"EIMM", cpu.S390X.HasEIMM, 21, true},
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{"DFP", cpu.S390X.HasDFP, 42, false},
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{"MSA", cpu.S390X.HasMSA, 17, false},
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{"VX", cpu.S390X.HasVX, 129, false},
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{"VXE", cpu.S390X.HasVXE, 135, false},
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}
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// bitIsSet reports whether the bit at index is set. The bit index
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// is in big endian order, so bit index 0 is the leftmost bit.
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func bitIsSet(bits [4]uint64, i uint) bool {
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return bits[i/64]&((1<<63)>>(i%64)) != 0
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}
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// facilityList contains the contents of location 200 on zos.
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// Bits are numbered in big endian order so the
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// leftmost bit (the MSB) is at index 0.
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type facilityList struct {
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bits [4]uint64
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}
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func TestS390XVectorFacilityFeatures(t *testing.T) {
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// vector-enhancements require vector facility to be enabled
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if cpu.S390X.HasVXE && !cpu.S390X.HasVX {
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t.Error("HasVX expected true, got false (VXE is true)")
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}
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}
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func TestS390XMandatoryFeatures(t *testing.T) {
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for _, tc := range s390xTests {
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if tc.mandatory && !tc.feature {
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t.Errorf("Feature %s is mandatory but is not present", tc.name)
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}
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}
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}
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func TestS390XFeatures(t *testing.T) {
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if runtime.GOOS != "zos" {
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return
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}
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// Read available facilities from address 200.
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facilitiesAddress := uintptr(200)
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var facilities facilityList
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for i := 0; i < 4; i++ {
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facilities.bits[i] = *(*uint64)(unsafe.Pointer(facilitiesAddress + uintptr(8*i)))
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}
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for _, tc := range s390xTests {
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if want := bitIsSet(facilities.bits, tc.facility); want != tc.feature {
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t.Errorf("Feature %s expected %v, got %v", tc.name, want, tc.feature)
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}
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}
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}
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