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| author | Thomas Weißschuh <thomas.weissschuh@linutronix.de> | 2026-03-16 10:36:00 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2026-03-16 10:36:00 +0800 |
| commit | c8b8f3c50f487b145433a6c3f95efd8790079a06 (patch) | |
| tree | 4024dc2ce45d5bc54172744fe25e4f4e2347d700 | |
| parent | f338e77383789c0cae23ca3d48adcc5e9e137e3c (diff) | |
LoongArch: Only use SC.Q when supported by the assembler
The 128-bit atomic cmpxchg implementation uses the SC.Q instruction.
Older versions of GNU AS do not support that instruction, erroring out:
ERROR:root:{standard input}: Assembler messages:
{standard input}:4831: Error: no match insn: sc.q $t0,$t1,$r14
{standard input}:6407: Error: no match insn: sc.q $t0,$t1,$r23
{standard input}:10856: Error: no match insn: sc.q $t0,$t1,$r14
make[4]: *** [../scripts/Makefile.build:289: mm/slub.o] Error 1
(Binutils 2.41)
So test support for SC.Q in Kconfig and disable the atomics if the
instruction is not available.
Fixes: f0e4b1b6e295 ("LoongArch: Add 128-bit atomic cmpxchg support")
Closes: https://lore.kernel.org/lkml/20260216082834-edc51c46-7b7a-4295-8ea5-4d9a3ca2224f@linutronix.de/
Reviewed-by: Xi Ruoyao <xry111@xry111.site>
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| -rw-r--r-- | arch/loongarch/Kconfig | 3 | ||||
| -rw-r--r-- | arch/loongarch/include/asm/cmpxchg.h | 5 |
2 files changed, 8 insertions, 0 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index d211c6572b0a..92068ff38685 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -304,6 +304,9 @@ config AS_HAS_LBT_EXTENSION config AS_HAS_LVZ_EXTENSION def_bool $(as-instr,hvcl 0) +config AS_HAS_SCQ_EXTENSION + def_bool $(as-instr,sc.q \$t0$(comma)\$t1$(comma)\$t2) + config CC_HAS_ANNOTATE_TABLEJUMP def_bool $(cc-option,-mannotate-tablejump) diff --git a/arch/loongarch/include/asm/cmpxchg.h b/arch/loongarch/include/asm/cmpxchg.h index 58cabab6d90d..909f9274fe71 100644 --- a/arch/loongarch/include/asm/cmpxchg.h +++ b/arch/loongarch/include/asm/cmpxchg.h @@ -238,6 +238,8 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, unsigned int arch_cmpxchg((ptr), (o), (n)); \ }) +#ifdef CONFIG_AS_HAS_SCQ_EXTENSION + union __u128_halves { u128 full; struct { @@ -290,6 +292,9 @@ union __u128_halves { BUILD_BUG_ON(sizeof(*(ptr)) != 16); \ __arch_cmpxchg128(ptr, o, n, ""); \ }) + +#endif /* CONFIG_AS_HAS_SCQ_EXTENSION */ + #else #include <asm-generic/cmpxchg-local.h> #define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n)) |