From ddc348c44d82d0b55236210d5606ac868e6cc364 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Sat, 9 May 2020 00:15:36 -0700 Subject: [PATCH] ARC: cmpxchg/xchg: implement relaxed variants (LLSC config only) It only makes sense to do this for the LLSC config Acked-by: Peter Zijlstra (Intel) Signed-off-by: Vineet Gupta --- arch/arc/include/asm/cmpxchg.h | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index 00deb076d6f6..e2ae0eb1ca07 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -38,7 +38,7 @@ _prev; \ }) -#define arch_cmpxchg(ptr, old, new) \ +#define arch_cmpxchg_relaxed(ptr, old, new) \ ({ \ __typeof__(ptr) _p_ = (ptr); \ __typeof__(*(ptr)) _o_ = (old); \ @@ -47,12 +47,7 @@ \ switch(sizeof((_p_))) { \ case 4: \ - /* \ - * Explicit full memory barrier needed before/after \ - */ \ - smp_mb(); \ _prev_ = __cmpxchg(_p_, _o_, _n_); \ - smp_mb(); \ break; \ default: \ BUILD_BUG(); \ @@ -108,16 +103,14 @@ _val_; /* get old value */ \ }) -#define arch_xchg(ptr, val) \ +#define arch_xchg_relaxed(ptr, val) \ ({ \ __typeof__(ptr) _p_ = (ptr); \ __typeof__(*(ptr)) _val_ = (val); \ \ switch(sizeof(*(_p_))) { \ case 4: \ - smp_mb(); \ _val_ = __xchg(_p_, _val_); \ - smp_mb(); \ break; \ default: \ BUILD_BUG(); \