runtime: don't use linkname to refer to internal/cpu

The runtime package already imports the internal/cpu package, so there
is no reason for it to use go:linkname comments to refer to
internal/cpu functions and variables. Since internal/cpu is internal,
we can just export those names. Removing the obscurity of go:linkname
outweighs the minor additional complexity added to the internal/cpu API.

Change-Id: Id89951b7f3fc67cd9bce67ac6d01d44a647a10ad
Reviewed-on: https://go-review.googlesource.com/128755
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>

1 files changed, 6 insertions, 13 deletions

diff --git a/src/runtime/os_linux_arm64.go b/src/runtime/os_linux_arm64.go
index 28a0319f10..cbe528b4af 100644
--- a/src/runtime/os_linux_arm64.go
+++ b/src/runtime/os_linux_arm64.go
@@ -6,20 +6,10 @@
 
 package runtime
 
-// For go:linkname
-import _ "unsafe"
+import "internal/cpu"
 
 var randomNumber uint32
 
-// arm64 doesn't have a 'cpuid' instruction equivalent and relies on
-// HWCAP/HWCAP2 bits for hardware capabilities.
-
-//go:linkname cpu_hwcap internal/cpu.hwcap
-var cpu_hwcap uint
-
-//go:linkname cpu_hwcap2 internal/cpu.hwcap2
-var cpu_hwcap2 uint
-
 func archauxv(tag, val uintptr) {
 	switch tag {
 	case _AT_RANDOM:
@@ -28,10 +18,13 @@ func archauxv(tag, val uintptr) {
 		// it as a byte array.
 		randomNumber = uint32(startupRandomData[4]) | uint32(startupRandomData[5])<<8 |
 			uint32(startupRandomData[6])<<16 | uint32(startupRandomData[7])<<24
+
 	case _AT_HWCAP:
-		cpu_hwcap = uint(val)
+		// arm64 doesn't have a 'cpuid' instruction equivalent and relies on
+		// HWCAP/HWCAP2 bits for hardware capabilities.
+		cpu.HWCap = uint(val)
 	case _AT_HWCAP2:
-		cpu_hwcap2 = uint(val)
+		cpu.HWCap2 = uint(val)
 	}
 }