[PATCH 11/11] ARC: atomic_cmpxchg/atomic_xchg: implement relaxed variants
From: Vineet Gupta <hidden>
Date: 2021-08-04 19:16:34
Also in:
lkml
Subsystem:
atomic infrastructure, synopsys arc architecture, the rest · Maintainers:
Will Deacon, Peter Zijlstra, Boqun Feng, Vineet Gupta, Linus Torvalds
And move them out of cmpxchg.h to canonical atomic.h Signed-off-by: Vineet Gupta <redacted> --- 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 ee88e1dbaab5..52ee51e1ff7c 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h@@ -22,6 +22,33 @@ #include <asm/atomic-spinlock.h> #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 <asm-generic/atomic64.h> #else
diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h
index e2ae0eb1ca07..c5b544a5fe81 100644
--- a/arch/arc/include/asm/cmpxchg.h
+++ b/arch/arc/include/asm/cmpxchg.h@@ -80,14 +80,6 @@ #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 */
@@ -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
--
2.25.1