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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:25:22 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:25:22 +0000
commitf6ad4dcef54c5ce997a4bad5a6d86de229015700 (patch)
tree7cfa4e31ace5c2bd95c72b154d15af494b2bcbef /src/runtime/internal/atomic/atomic_arm.s
parentInitial commit. (diff)
downloadgolang-1.22-f6ad4dcef54c5ce997a4bad5a6d86de229015700.tar.xz
golang-1.22-f6ad4dcef54c5ce997a4bad5a6d86de229015700.zip
Adding upstream version 1.22.1.upstream/1.22.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/runtime/internal/atomic/atomic_arm.s')
-rw-r--r--src/runtime/internal/atomic/atomic_arm.s312
1 files changed, 312 insertions, 0 deletions
diff --git a/src/runtime/internal/atomic/atomic_arm.s b/src/runtime/internal/atomic/atomic_arm.s
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+// Copyright 2015 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 "go_asm.h"
+#include "textflag.h"
+#include "funcdata.h"
+
+// bool armcas(int32 *val, int32 old, int32 new)
+// Atomically:
+// if(*val == old){
+// *val = new;
+// return 1;
+// }else
+// return 0;
+//
+// To implement ·cas in sys_$GOOS_arm.s
+// using the native instructions, use:
+//
+// TEXT ·cas(SB),NOSPLIT,$0
+// B ·armcas(SB)
+//
+TEXT ·armcas(SB),NOSPLIT,$0-13
+ MOVW ptr+0(FP), R1
+ MOVW old+4(FP), R2
+ MOVW new+8(FP), R3
+casl:
+ LDREX (R1), R0
+ CMP R0, R2
+ BNE casfail
+
+#ifndef GOARM_7
+ MOVB internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
+ CMP $0, R11
+ BEQ 2(PC)
+#endif
+ DMB MB_ISHST
+
+ STREX R3, (R1), R0
+ CMP $0, R0
+ BNE casl
+ MOVW $1, R0
+
+#ifndef GOARM_7
+ CMP $0, R11
+ BEQ 2(PC)
+#endif
+ DMB MB_ISH
+
+ MOVB R0, ret+12(FP)
+ RET
+casfail:
+ MOVW $0, R0
+ MOVB R0, ret+12(FP)
+ RET
+
+// stubs
+
+TEXT ·Loadp(SB),NOSPLIT|NOFRAME,$0-8
+ B ·Load(SB)
+
+TEXT ·LoadAcq(SB),NOSPLIT|NOFRAME,$0-8
+ B ·Load(SB)
+
+TEXT ·LoadAcquintptr(SB),NOSPLIT|NOFRAME,$0-8
+ B ·Load(SB)
+
+TEXT ·Casint32(SB),NOSPLIT,$0-13
+ B ·Cas(SB)
+
+TEXT ·Casint64(SB),NOSPLIT,$-4-21
+ B ·Cas64(SB)
+
+TEXT ·Casuintptr(SB),NOSPLIT,$0-13
+ B ·Cas(SB)
+
+TEXT ·Casp1(SB),NOSPLIT,$0-13
+ B ·Cas(SB)
+
+TEXT ·CasRel(SB),NOSPLIT,$0-13
+ B ·Cas(SB)
+
+TEXT ·Loadint32(SB),NOSPLIT,$0-8
+ B ·Load(SB)
+
+TEXT ·Loadint64(SB),NOSPLIT,$-4-12
+ B ·Load64(SB)
+
+TEXT ·Loaduintptr(SB),NOSPLIT,$0-8
+ B ·Load(SB)
+
+TEXT ·Loaduint(SB),NOSPLIT,$0-8
+ B ·Load(SB)
+
+TEXT ·Storeint32(SB),NOSPLIT,$0-8
+ B ·Store(SB)
+
+TEXT ·Storeint64(SB),NOSPLIT,$0-12
+ B ·Store64(SB)
+
+TEXT ·Storeuintptr(SB),NOSPLIT,$0-8
+ B ·Store(SB)
+
+TEXT ·StorepNoWB(SB),NOSPLIT,$0-8
+ B ·Store(SB)
+
+TEXT ·StoreRel(SB),NOSPLIT,$0-8
+ B ·Store(SB)
+
+TEXT ·StoreReluintptr(SB),NOSPLIT,$0-8
+ B ·Store(SB)
+
+TEXT ·Xaddint32(SB),NOSPLIT,$0-12
+ B ·Xadd(SB)
+
+TEXT ·Xaddint64(SB),NOSPLIT,$-4-20
+ B ·Xadd64(SB)
+
+TEXT ·Xadduintptr(SB),NOSPLIT,$0-12
+ B ·Xadd(SB)
+
+TEXT ·Xchgint32(SB),NOSPLIT,$0-12
+ B ·Xchg(SB)
+
+TEXT ·Xchgint64(SB),NOSPLIT,$-4-20
+ B ·Xchg64(SB)
+
+// 64-bit atomics
+// The native ARM implementations use LDREXD/STREXD, which are
+// available on ARMv6k or later. We use them only on ARMv7.
+// On older ARM, we use Go implementations which simulate 64-bit
+// atomics with locks.
+TEXT armCas64<>(SB),NOSPLIT,$0-21
+ // addr is already in R1
+ MOVW old_lo+4(FP), R2
+ MOVW old_hi+8(FP), R3
+ MOVW new_lo+12(FP), R4
+ MOVW new_hi+16(FP), R5
+cas64loop:
+ LDREXD (R1), R6 // loads R6 and R7
+ CMP R2, R6
+ BNE cas64fail
+ CMP R3, R7
+ BNE cas64fail
+
+ DMB MB_ISHST
+
+ STREXD R4, (R1), R0 // stores R4 and R5
+ CMP $0, R0
+ BNE cas64loop
+ MOVW $1, R0
+
+ DMB MB_ISH
+
+ MOVBU R0, swapped+20(FP)
+ RET
+cas64fail:
+ MOVW $0, R0
+ MOVBU R0, swapped+20(FP)
+ RET
+
+TEXT armXadd64<>(SB),NOSPLIT,$0-20
+ // addr is already in R1
+ MOVW delta_lo+4(FP), R2
+ MOVW delta_hi+8(FP), R3
+
+add64loop:
+ LDREXD (R1), R4 // loads R4 and R5
+ ADD.S R2, R4
+ ADC R3, R5
+
+ DMB MB_ISHST
+
+ STREXD R4, (R1), R0 // stores R4 and R5
+ CMP $0, R0
+ BNE add64loop
+
+ DMB MB_ISH
+
+ MOVW R4, new_lo+12(FP)
+ MOVW R5, new_hi+16(FP)
+ RET
+
+TEXT armXchg64<>(SB),NOSPLIT,$0-20
+ // addr is already in R1
+ MOVW new_lo+4(FP), R2
+ MOVW new_hi+8(FP), R3
+
+swap64loop:
+ LDREXD (R1), R4 // loads R4 and R5
+
+ DMB MB_ISHST
+
+ STREXD R2, (R1), R0 // stores R2 and R3
+ CMP $0, R0
+ BNE swap64loop
+
+ DMB MB_ISH
+
+ MOVW R4, old_lo+12(FP)
+ MOVW R5, old_hi+16(FP)
+ RET
+
+TEXT armLoad64<>(SB),NOSPLIT,$0-12
+ // addr is already in R1
+
+ LDREXD (R1), R2 // loads R2 and R3
+ DMB MB_ISH
+
+ MOVW R2, val_lo+4(FP)
+ MOVW R3, val_hi+8(FP)
+ RET
+
+TEXT armStore64<>(SB),NOSPLIT,$0-12
+ // addr is already in R1
+ MOVW val_lo+4(FP), R2
+ MOVW val_hi+8(FP), R3
+
+store64loop:
+ LDREXD (R1), R4 // loads R4 and R5
+
+ DMB MB_ISHST
+
+ STREXD R2, (R1), R0 // stores R2 and R3
+ CMP $0, R0
+ BNE store64loop
+
+ DMB MB_ISH
+ RET
+
+// The following functions all panic if their address argument isn't
+// 8-byte aligned. Since we're calling back into Go code to do this,
+// we have to cooperate with stack unwinding. In the normal case, the
+// functions tail-call into the appropriate implementation, which
+// means they must not open a frame. Hence, when they go down the
+// panic path, at that point they push the LR to create a real frame
+// (they don't need to pop it because panic won't return; however, we
+// do need to set the SP delta back).
+
+// Check if R1 is 8-byte aligned, panic if not.
+// Clobbers R2.
+#define CHECK_ALIGN \
+ AND.S $7, R1, R2 \
+ BEQ 4(PC) \
+ MOVW.W R14, -4(R13) /* prepare a real frame */ \
+ BL ·panicUnaligned(SB) \
+ ADD $4, R13 /* compensate SP delta */
+
+TEXT ·Cas64(SB),NOSPLIT,$-4-21
+ NO_LOCAL_POINTERS
+ MOVW addr+0(FP), R1
+ CHECK_ALIGN
+
+#ifndef GOARM_7
+ MOVB internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
+ CMP $1, R11
+ BEQ 2(PC)
+ JMP ·goCas64(SB)
+#endif
+ JMP armCas64<>(SB)
+
+TEXT ·Xadd64(SB),NOSPLIT,$-4-20
+ NO_LOCAL_POINTERS
+ MOVW addr+0(FP), R1
+ CHECK_ALIGN
+
+#ifndef GOARM_7
+ MOVB internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
+ CMP $1, R11
+ BEQ 2(PC)
+ JMP ·goXadd64(SB)
+#endif
+ JMP armXadd64<>(SB)
+
+TEXT ·Xchg64(SB),NOSPLIT,$-4-20
+ NO_LOCAL_POINTERS
+ MOVW addr+0(FP), R1
+ CHECK_ALIGN
+
+#ifndef GOARM_7
+ MOVB internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
+ CMP $1, R11
+ BEQ 2(PC)
+ JMP ·goXchg64(SB)
+#endif
+ JMP armXchg64<>(SB)
+
+TEXT ·Load64(SB),NOSPLIT,$-4-12
+ NO_LOCAL_POINTERS
+ MOVW addr+0(FP), R1
+ CHECK_ALIGN
+
+#ifndef GOARM_7
+ MOVB internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
+ CMP $1, R11
+ BEQ 2(PC)
+ JMP ·goLoad64(SB)
+#endif
+ JMP armLoad64<>(SB)
+
+TEXT ·Store64(SB),NOSPLIT,$-4-12
+ NO_LOCAL_POINTERS
+ MOVW addr+0(FP), R1
+ CHECK_ALIGN
+
+#ifndef GOARM_7
+ MOVB internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
+ CMP $1, R11
+ BEQ 2(PC)
+ JMP ·goStore64(SB)
+#endif
+ JMP armStore64<>(SB)