From: Jason Gunthorpe Date: Tue, 8 Apr 2025 17:22:56 +0000 (-0300) Subject: ARC: atomics: Implement arch_atomic64_cmpxchg using _relaxed X-Git-Tag: v6.16-rc2~22^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ea7caffedd011f7d40abe93a884ffbe46f122535;p=thirdparty%2Fkernel%2Flinux.git ARC: atomics: Implement arch_atomic64_cmpxchg using _relaxed The core atomic code has a number of macros where it elaborates architecture primitives into more functions. ARC uses arch_atomic64_cmpxchg() as it's architecture primitive which disable alot of the additional functions. Instead provide arch_cmpxchg64_relaxed() as the primitive and rely on the core macros to create arch_cmpxchg64(). The macros will also provide other functions, for instance, try_cmpxchg64_release(), giving a more complete implementation. Suggested-by: Mark Rutland Link: https://lore.kernel.org/r/Z0747n5bSep4_1VX@J2N7QTR9R3 Signed-off-by: Jason Gunthorpe Signed-off-by: Vineet Gupta --- diff --git a/arch/arc/include/asm/atomic64-arcv2.h b/arch/arc/include/asm/atomic64-arcv2.h index 9b5791b854713..73080a664369b 100644 --- a/arch/arc/include/asm/atomic64-arcv2.h +++ b/arch/arc/include/asm/atomic64-arcv2.h @@ -137,12 +137,9 @@ ATOMIC64_OPS(xor, xor, xor) #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP -static inline s64 -arch_atomic64_cmpxchg(atomic64_t *ptr, s64 expected, s64 new) +static inline u64 __arch_cmpxchg64_relaxed(volatile void *ptr, u64 old, u64 new) { - s64 prev; - - smp_mb(); + u64 prev; __asm__ __volatile__( "1: llockd %0, [%1] \n" @@ -152,14 +149,12 @@ arch_atomic64_cmpxchg(atomic64_t *ptr, s64 expected, s64 new) " bnz 1b \n" "2: \n" : "=&r"(prev) - : "r"(ptr), "ir"(expected), "r"(new) - : "cc"); /* memory clobber comes from smp_mb() */ - - smp_mb(); + : "r"(ptr), "ir"(old), "r"(new) + : "memory", "cc"); return prev; } -#define arch_atomic64_cmpxchg arch_atomic64_cmpxchg +#define arch_cmpxchg64_relaxed __arch_cmpxchg64_relaxed static inline s64 arch_atomic64_xchg(atomic64_t *ptr, s64 new) {