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authorRichard Miller <miller.research@gmail.com>2016-01-27 16:18:34 +0000
committerBrad Fitzpatrick <bradfitz@golang.org>2016-02-26 20:16:34 +0000
commit5c613e9162aad2ea171d401754d97ea2be1442ce (patch)
tree419a4bde3300ca13928b870b9d07ab18a6d8bb8e /src/sync
parent5c72c6f889ad854ba16e4ed560e6ad10ebb6dcc4 (diff)
downloadgo-5c613e9162aad2ea171d401754d97ea2be1442ce.tar.xz
sync/atomic: new file for plan9_arm support
Atomic load/store/add/swap routines, as for other ARM platforms, but with DMB inserted for load/store (assuming that "atomic" also implies acquire/release memory ordering). Change-Id: I70a283d8f0ae61a66432998ce59eac76fd940c67 Reviewed-on: https://go-review.googlesource.com/18965 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/sync')
-rw-r--r--src/sync/atomic/asm_plan9_arm.s108
1 files changed, 108 insertions, 0 deletions
diff --git a/src/sync/atomic/asm_plan9_arm.s b/src/sync/atomic/asm_plan9_arm.s
new file mode 100644
index 0000000000..5108fc6b91
--- /dev/null
+++ b/src/sync/atomic/asm_plan9_arm.s
@@ -0,0 +1,108 @@
+// Copyright 2012 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.
+
+#include "textflag.h"
+
+#define DMB_ISH_7 \
+ MOVB runtime·goarm(SB), R11; \
+ CMP $7, R11; \
+ BLT 2(PC); \
+ WORD $0xf57ff05b // dmb ish
+
+// Plan9/ARM atomic operations.
+// TODO(minux): this only supports ARMv6K or higher.
+
+TEXT ·CompareAndSwapInt32(SB),NOSPLIT,$0
+ B ·CompareAndSwapUint32(SB)
+
+TEXT ·CompareAndSwapUint32(SB),NOSPLIT,$0
+ B ·armCompareAndSwapUint32(SB)
+
+TEXT ·CompareAndSwapUintptr(SB),NOSPLIT,$0
+ B ·CompareAndSwapUint32(SB)
+
+TEXT ·AddInt32(SB),NOSPLIT,$0
+ B ·AddUint32(SB)
+
+TEXT ·AddUint32(SB),NOSPLIT,$0
+ B ·armAddUint32(SB)
+
+TEXT ·AddUintptr(SB),NOSPLIT,$0
+ B ·AddUint32(SB)
+
+TEXT ·SwapInt32(SB),NOSPLIT,$0
+ B ·SwapUint32(SB)
+
+TEXT ·SwapUint32(SB),NOSPLIT,$0
+ B ·armSwapUint32(SB)
+
+TEXT ·SwapUintptr(SB),NOSPLIT,$0
+ B ·SwapUint32(SB)
+
+TEXT ·CompareAndSwapInt64(SB),NOSPLIT,$0
+ B ·CompareAndSwapUint64(SB)
+
+TEXT ·CompareAndSwapUint64(SB),NOSPLIT,$-4
+ B ·armCompareAndSwapUint64(SB)
+
+TEXT ·AddInt64(SB),NOSPLIT,$0
+ B ·addUint64(SB)
+
+TEXT ·AddUint64(SB),NOSPLIT,$0
+ B ·addUint64(SB)
+
+TEXT ·SwapInt64(SB),NOSPLIT,$0
+ B ·swapUint64(SB)
+
+TEXT ·SwapUint64(SB),NOSPLIT,$0
+ B ·swapUint64(SB)
+
+TEXT ·LoadInt32(SB),NOSPLIT,$0
+ B ·LoadUint32(SB)
+
+TEXT ·LoadUint32(SB),NOSPLIT,$0-8
+ MOVW addr+0(FP), R1
+load32loop:
+ LDREX (R1), R2 // loads R2
+ STREX R2, (R1), R0 // stores R2
+ CMP $0, R0
+ BNE load32loop
+ MOVW R2, val+4(FP)
+ DMB_ISH_7
+ RET
+
+TEXT ·LoadInt64(SB),NOSPLIT,$0
+ B ·loadUint64(SB)
+
+TEXT ·LoadUint64(SB),NOSPLIT,$0
+ B ·loadUint64(SB)
+
+TEXT ·LoadUintptr(SB),NOSPLIT,$0
+ B ·LoadUint32(SB)
+
+TEXT ·LoadPointer(SB),NOSPLIT,$0
+ B ·LoadUint32(SB)
+
+TEXT ·StoreInt32(SB),NOSPLIT,$0
+ B ·StoreUint32(SB)
+
+TEXT ·StoreUint32(SB),NOSPLIT,$0-8
+ MOVW addr+0(FP), R1
+ MOVW val+4(FP), R2
+ DMB_ISH_7
+storeloop:
+ LDREX (R1), R4 // loads R4
+ STREX R2, (R1), R0 // stores R2
+ CMP $0, R0
+ BNE storeloop
+ RET
+
+TEXT ·StoreInt64(SB),NOSPLIT,$0
+ B ·storeUint64(SB)
+
+TEXT ·StoreUint64(SB),NOSPLIT,$0
+ B ·storeUint64(SB)
+
+TEXT ·StoreUintptr(SB),NOSPLIT,$0
+ B ·StoreUint32(SB)