From 301014cf6d72836dd5fd5b3e9c92633f35b298c0 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 11 May 2020 13:27:23 -0700 Subject: [PATCH] ARC: atomic_cmpxchg/atomic_xchg: implement relaxed variants And move them out of cmpxchg.h to canonical atomic.h Acked-by: Peter Zijlstra (Intel) Signed-off-by: Vineet Gupta --- arch/arc/include/asm/atomic.h | 27 +++++++++++++++++++++++++++ arch/arc/include/asm/cmpxchg.h | 23 ----------------------- 2 files changed, 27 insertions(+), 23 deletions(-) diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index ee88e1d..52ee51e 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -22,6 +22,33 @@ #include #endif +#define arch_atomic_cmpxchg(v, o, n) \ +({ \ + arch_cmpxchg(&((v)->counter), (o), (n)); \ +}) + +#ifdef arch_cmpxchg_relaxed +#define arch_atomic_cmpxchg_relaxed(v, o, n) \ +({ \ + arch_cmpxchg_relaxed(&((v)->counter), (o), (n)); \ +}) +#endif + +#define arch_atomic_xchg(v, n) \ +({ \ + arch_xchg(&((v)->counter), (n)); \ +}) + +#ifdef arch_xchg_relaxed +#define arch_atomic_xchg_relaxed(v, n) \ +({ \ + arch_xchg_relaxed(&((v)->counter), (n)); \ +}) +#endif + +/* + * 64-bit atomics + */ #ifdef CONFIG_GENERIC_ATOMIC64 #include #else diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index e2ae0eb..c5b544a 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -81,14 +81,6 @@ #endif /* - * atomic_cmpxchg is same as cmpxchg - * LLSC: only different in data-type, semantics are exactly same - * !LLSC: cmpxchg() has to use an external lock atomic_ops_lock to guarantee - * semantics, and this lock also happens to be used by atomic_*() - */ -#define arch_atomic_cmpxchg(v, o, n) ((int)arch_cmpxchg(&((v)->counter), (o), (n))) - -/* * xchg */ #ifdef CONFIG_ARC_HAS_LLSC @@ -148,19 +140,4 @@ #endif -/* - * "atomic" variant of xchg() - * REQ: It needs to follow the same serialization rules as other atomic_xxx() - * Since xchg() doesn't always do that, it would seem that following definition - * is incorrect. But here's the rationale: - * SMP : Even xchg() takes the atomic_ops_lock, so OK. - * LLSC: atomic_ops_lock are not relevant at all (even if SMP, since LLSC - * is natively "SMP safe", no serialization required). - * UP : other atomics disable IRQ, so no way a difft ctxt atomic_xchg() - * could clobber them. atomic_xchg() itself would be 1 insn, so it - * can't be clobbered by others. Thus no serialization required when - * atomic_xchg is involved. - */ -#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), new)) - #endif -- 2.7.4