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| From f55aaf7648c036e0206da45254ff9698c4c5e12c Mon Sep 17 00:00:00 2001
| From: Khem Raj <raj.khem@gmail.com>
| Date: Wed, 24 Mar 2021 00:32:09 -0700
| Subject: [PATCH] compiler-rt: Use mcr based barrier on armv6
|
| dsb is an armv7 instruction and wont work when we are building for armv6.
|
| Upstream-Status: Pending
| Signed-off-by: Khem Raj <raj.khem@gmail.com>
| ---
| compiler-rt/lib/builtins/arm/sync-ops.h | 8 ++++----
| compiler-rt/lib/builtins/assembly.h | 8 ++++++++
| 2 files changed, 12 insertions(+), 4 deletions(-)
|
| diff --git a/compiler-rt/lib/builtins/arm/sync-ops.h b/compiler-rt/lib/builtins/arm/sync-ops.h
| index c9623249e5d2..7a26170741ad 100644
| --- a/compiler-rt/lib/builtins/arm/sync-ops.h
| +++ b/compiler-rt/lib/builtins/arm/sync-ops.h
| @@ -19,14 +19,14 @@
| .thumb; \
| .syntax unified; \
| DEFINE_COMPILERRT_THUMB_FUNCTION(__sync_fetch_and_##op) \
| - dmb; \
| + DMB; \
| mov r12, r0; \
| LOCAL_LABEL(tryatomic_##op) : ldrex r0, [r12]; \
| op(r2, r0, r1); \
| strex r3, r2, [r12]; \
| cmp r3, #0; \
| bne LOCAL_LABEL(tryatomic_##op); \
| - dmb; \
| + DMB; \
| bx lr
|
| #define SYNC_OP_8(op) \
| @@ -35,14 +35,14 @@
| .syntax unified; \
| DEFINE_COMPILERRT_THUMB_FUNCTION(__sync_fetch_and_##op) \
| push {r4, r5, r6, lr}; \
| - dmb; \
| + DMB; \
| mov r12, r0; \
| LOCAL_LABEL(tryatomic_##op) : ldrexd r0, r1, [r12]; \
| op(r4, r5, r0, r1, r2, r3); \
| strexd r6, r4, r5, [r12]; \
| cmp r6, #0; \
| bne LOCAL_LABEL(tryatomic_##op); \
| - dmb; \
| + DMB; \
| pop { r4, r5, r6, pc }
|
| #define MINMAX_4(rD, rN, rM, cmp_kind) \
| diff --git a/compiler-rt/lib/builtins/assembly.h b/compiler-rt/lib/builtins/assembly.h
| index 9c015059af5a..aec4ff59beb7 100644
| --- a/compiler-rt/lib/builtins/assembly.h
| +++ b/compiler-rt/lib/builtins/assembly.h
| @@ -183,6 +183,14 @@
| JMP(ip)
| #endif
|
| +#if __ARM_ARCH >= 7
| +#define DMB dmb
| +#elif __ARM_ARCH >= 6
| +#define DMB mcr p15, #0, r0, c7, c10, #5
| +#else
| +#error Only use this with ARMv6+
| +#endif
| +
| #if defined(USE_THUMB_2)
| #define WIDE(op) op.w
| #else
|
|
