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// 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
const cacheLineSize = 256
const (
// bit mask values from /usr/include/bits/hwcap.h
hwcap_ZARCH = 2
hwcap_STFLE = 4
hwcap_MSA = 8
hwcap_LDISP = 16
hwcap_EIMM = 32
hwcap_DFP = 64
hwcap_ETF3EH = 256
hwcap_VX = 2048
hwcap_VXE = 8192
)
// bitIsSet reports whether the bit at index is set. The bit index
// is in big endian order, so bit index 0 is the leftmost bit.
func bitIsSet(bits []uint64, index uint) bool {
return bits[index/64]&((1<<63)>>(index%64)) != 0
}
// function is the code for the named cryptographic function.
type function uint8
const (
// KM{,A,C,CTR} function codes
aes128 function = 18 // AES-128
aes192 function = 19 // AES-192
aes256 function = 20 // AES-256
// K{I,L}MD function codes
sha1 function = 1 // SHA-1
sha256 function = 2 // SHA-256
sha512 function = 3 // SHA-512
sha3_224 function = 32 // SHA3-224
sha3_256 function = 33 // SHA3-256
sha3_384 function = 34 // SHA3-384
sha3_512 function = 35 // SHA3-512
shake128 function = 36 // SHAKE-128
shake256 function = 37 // SHAKE-256
// KLMD function codes
ghash function = 65 // GHASH
)
// queryResult contains the result of a Query function
// call. Bits are numbered in big endian order so the
// leftmost bit (the MSB) is at index 0.
type queryResult struct {
bits [2]uint64
}
// Has reports whether the given functions are present.
func (q *queryResult) Has(fns ...function) bool {
if len(fns) == 0 {
panic("no function codes provided")
}
for _, f := range fns {
if !bitIsSet(q.bits[:], uint(f)) {
return false
}
}
return true
}
// facility is a bit index for the named facility.
type facility uint8
const (
// cryptography facilities
msa4 facility = 77 // message-security-assist extension 4
msa8 facility = 146 // message-security-assist extension 8
)
// facilityList contains the result of an STFLE call.
// Bits are numbered in big endian order so the
// leftmost bit (the MSB) is at index 0.
type facilityList struct {
bits [4]uint64
}
// Has reports whether the given facilities are present.
func (s *facilityList) Has(fs ...facility) bool {
if len(fs) == 0 {
panic("no facility bits provided")
}
for _, f := range fs {
if !bitIsSet(s.bits[:], uint(f)) {
return false
}
}
return true
}
func doinit() {
// test HWCAP bit vector
has := func(featureMask uint) bool {
return hwCap&featureMask == featureMask
}
// mandatory
S390X.HasZARCH = has(hwcap_ZARCH)
// optional
S390X.HasSTFLE = has(hwcap_STFLE)
S390X.HasLDISP = has(hwcap_LDISP)
S390X.HasEIMM = has(hwcap_EIMM)
S390X.HasETF3EH = has(hwcap_ETF3EH)
S390X.HasDFP = has(hwcap_DFP)
S390X.HasMSA = has(hwcap_MSA)
S390X.HasVX = has(hwcap_VX)
if S390X.HasVX {
S390X.HasVXE = has(hwcap_VXE)
}
// We need implementations of stfle, km and so on
// to detect cryptographic features.
if !haveAsmFunctions() {
return
}
// optional cryptographic functions
if S390X.HasMSA {
aes := []function{aes128, aes192, aes256}
// cipher message
km, kmc := kmQuery(), kmcQuery()
S390X.HasAES = km.Has(aes...)
S390X.HasAESCBC = kmc.Has(aes...)
if S390X.HasSTFLE {
facilities := stfle()
if facilities.Has(msa4) {
kmctr := kmctrQuery()
S390X.HasAESCTR = kmctr.Has(aes...)
}
if facilities.Has(msa8) {
kma := kmaQuery()
S390X.HasAESGCM = kma.Has(aes...)
}
}
// compute message digest
kimd := kimdQuery() // intermediate (no padding)
klmd := klmdQuery() // last (padding)
S390X.HasSHA1 = kimd.Has(sha1) && klmd.Has(sha1)
S390X.HasSHA256 = kimd.Has(sha256) && klmd.Has(sha256)
S390X.HasSHA512 = kimd.Has(sha512) && klmd.Has(sha512)
S390X.HasGHASH = kimd.Has(ghash) // KLMD-GHASH does not exist
sha3 := []function{
sha3_224, sha3_256, sha3_384, sha3_512,
shake128, shake256,
}
S390X.HasSHA3 = kimd.Has(sha3...) && klmd.Has(sha3...)
}
}