1 files changed, 205 insertions, 0 deletions
diff --git a/src/internal/cpu/cpu_s390x.go b/src/internal/cpu/cpu_s390x.go
new file mode 100644
index 0000000..45d8ed2
--- /dev/null
+++ b/src/internal/cpu/cpu_s390x.go
@@ -0,0 +1,205 @@
+// Copyright 2017 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 CacheLinePadSize = 256
+
+var HWCap uint
+
+// 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 function code for the named 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
+)
+
+const (
+	// KDSA function codes
+	ecdsaVerifyP256    function = 1  // NIST P256
+	ecdsaVerifyP384    function = 2  // NIST P384
+	ecdsaVerifyP521    function = 3  // NIST P521
+	ecdsaSignP256      function = 9  // NIST P256
+	ecdsaSignP384      function = 10 // NIST P384
+	ecdsaSignP521      function = 11 // NIST P521
+	eddsaVerifyEd25519 function = 32 // Curve25519
+	eddsaVerifyEd448   function = 36 // Curve448
+	eddsaSignEd25519   function = 40 // Curve25519
+	eddsaSignEd448     function = 44 // Curve448
+)
+
+// 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 (
+	// mandatory facilities
+	zarch  facility = 1  // z architecture mode is active
+	stflef facility = 7  // store-facility-list-extended
+	ldisp  facility = 18 // long-displacement
+	eimm   facility = 21 // extended-immediate
+
+	// miscellaneous facilities
+	dfp    facility = 42 // decimal-floating-point
+	etf3eh facility = 30 // extended-translation 3 enhancement
+
+	// cryptography facilities
+	msa  facility = 17  // message-security-assist
+	msa3 facility = 76  // message-security-assist extension 3
+	msa4 facility = 77  // message-security-assist extension 4
+	msa5 facility = 57  // message-security-assist extension 5
+	msa8 facility = 146 // message-security-assist extension 8
+	msa9 facility = 155 // message-security-assist extension 9
+
+	// vector facilities
+	vxe facility = 135 // vector-enhancements 1
+
+	// Note: vx requires kernel support
+	// and so must be fetched from HWCAP.
+
+	hwcap_VX = 1 << 11 // vector facility
+)
+
+// 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
+}
+
+// The following feature detection functions are defined in cpu_s390x.s.
+// They are likely to be expensive to call so the results should be cached.
+func stfle() facilityList
+func kmQuery() queryResult
+func kmcQuery() queryResult
+func kmctrQuery() queryResult
+func kmaQuery() queryResult
+func kimdQuery() queryResult
+func klmdQuery() queryResult
+func kdsaQuery() queryResult
+
+func doinit() {
+	options = []option{
+		{Name: "zarch", Feature: &S390X.HasZARCH},
+		{Name: "stfle", Feature: &S390X.HasSTFLE},
+		{Name: "ldisp", Feature: &S390X.HasLDISP},
+		{Name: "msa", Feature: &S390X.HasMSA},
+		{Name: "eimm", Feature: &S390X.HasEIMM},
+		{Name: "dfp", Feature: &S390X.HasDFP},
+		{Name: "etf3eh", Feature: &S390X.HasETF3EH},
+		{Name: "vx", Feature: &S390X.HasVX},
+		{Name: "vxe", Feature: &S390X.HasVXE},
+		{Name: "kdsa", Feature: &S390X.HasKDSA},
+	}
+
+	aes := []function{aes128, aes192, aes256}
+	facilities := stfle()
+
+	S390X.HasZARCH = facilities.Has(zarch)
+	S390X.HasSTFLE = facilities.Has(stflef)
+	S390X.HasLDISP = facilities.Has(ldisp)
+	S390X.HasEIMM = facilities.Has(eimm)
+	S390X.HasDFP = facilities.Has(dfp)
+	S390X.HasETF3EH = facilities.Has(etf3eh)
+	S390X.HasMSA = facilities.Has(msa)
+
+	if S390X.HasMSA {
+		// cipher message
+		km, kmc := kmQuery(), kmcQuery()
+		S390X.HasAES = km.Has(aes...)
+		S390X.HasAESCBC = kmc.Has(aes...)
+		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...)
+		S390X.HasKDSA = facilities.Has(msa9) // elliptic curves
+		if S390X.HasKDSA {
+			kdsa := kdsaQuery()
+			S390X.HasECDSA = kdsa.Has(ecdsaVerifyP256, ecdsaSignP256, ecdsaVerifyP384, ecdsaSignP384, ecdsaVerifyP521, ecdsaSignP521)
+			S390X.HasEDDSA = kdsa.Has(eddsaVerifyEd25519, eddsaSignEd25519, eddsaVerifyEd448, eddsaSignEd448)
+		}
+	}
+
+	S390X.HasVX = isSet(HWCap, hwcap_VX)
+
+	if S390X.HasVX {
+		S390X.HasVXE = facilities.Has(vxe)
+	}
+}
+
+func isSet(hwc uint, value uint) bool {
+	return hwc&value != 0
+}