cpu: add support for DIT detection

Change-Id: I9f0991da9684ebd297e40a754e34130c418c34d0 Reviewed-on: https://go-review.googlesource.com/c/sys/+/597377 Reviewed-by: Ian Lance Taylor <[email protected]> LUCI-TryBot-Result: Go LUCI <[email protected]>
golang · Jul 11, 2024 · 47fe916 · 47fe916
1 parent 4cafe5c
commit 47fe916
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diff --git a/cpu/cpu.go b/cpu/cpu.go
@@ -105,6 +105,7 @@ var ARM64 struct {
 	HasSVE      bool // Scalable Vector Extensions
 	HasSVE2     bool // Scalable Vector Extensions 2
 	HasASIMDFHM bool // Advanced SIMD multiplication FP16 to FP32
+	HasDIT      bool // Data Independent Timing support
 	_           CacheLinePad
 }
 

diff --git a/cpu/cpu_arm64.go b/cpu/cpu_arm64.go
@@ -168,6 +168,11 @@ func parseARM64SystemRegisters(isar0, isar1, pfr0 uint64) {
 
 		parseARM64SVERegister(getzfr0())
 	}
+
+	switch extractBits(pfr0, 48, 51) {
+	case 1:
+		ARM64.HasDIT = true
+	}
 }
 
 func parseARM64SVERegister(zfr0 uint64) {