From e5857a6ed6004cac5273b8cdc189ab4b6363cfaf Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 18 Apr 2016 01:16:05 +0200 Subject: [PATCH] locking/atomic, arch/parisc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Helge Deller Cc: James E.J. Bottomley Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-parisc@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/parisc/include/asm/atomic.h | 65 ++++++++++++++++++++++++++++---- 1 file changed, 57 insertions(+), 8 deletions(-) diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index 1d109990a022..29df1f871910 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -121,16 +121,41 @@ static __inline__ int atomic_##op##_return(int i, atomic_t *v) \ return ret; \ } -#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op) +#define ATOMIC_FETCH_OP(op, c_op) \ +static __inline__ int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + unsigned long flags; \ + int ret; \ + \ + _atomic_spin_lock_irqsave(v, flags); \ + ret = v->counter; \ + v->counter c_op i; \ + _atomic_spin_unlock_irqrestore(v, flags); \ + \ + return ret; \ +} + +#define ATOMIC_OPS(op, c_op) \ + ATOMIC_OP(op, c_op) \ + ATOMIC_OP_RETURN(op, c_op) \ + ATOMIC_FETCH_OP(op, c_op) ATOMIC_OPS(add, +=) ATOMIC_OPS(sub, -=) -ATOMIC_OP(and, &=) -ATOMIC_OP(or, |=) -ATOMIC_OP(xor, ^=) +#undef ATOMIC_OPS +#define ATOMIC_OPS(op, c_op) \ + ATOMIC_OP(op, c_op) \ + ATOMIC_FETCH_OP(op, c_op) + +#define atomic_fetch_or atomic_fetch_or + +ATOMIC_OPS(and, &=) +ATOMIC_OPS(or, |=) +ATOMIC_OPS(xor, ^=) #undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP @@ -185,15 +210,39 @@ static __inline__ s64 atomic64_##op##_return(s64 i, atomic64_t *v) \ return ret; \ } -#define ATOMIC64_OPS(op, c_op) ATOMIC64_OP(op, c_op) ATOMIC64_OP_RETURN(op, c_op) +#define ATOMIC64_FETCH_OP(op, c_op) \ +static __inline__ s64 atomic64_fetch_##op(s64 i, atomic64_t *v) \ +{ \ + unsigned long flags; \ + s64 ret; \ + \ + _atomic_spin_lock_irqsave(v, flags); \ + ret = v->counter; \ + v->counter c_op i; \ + _atomic_spin_unlock_irqrestore(v, flags); \ + \ + return ret; \ +} + +#define ATOMIC64_OPS(op, c_op) \ + ATOMIC64_OP(op, c_op) \ + ATOMIC64_OP_RETURN(op, c_op) \ + ATOMIC64_FETCH_OP(op, c_op) ATOMIC64_OPS(add, +=) ATOMIC64_OPS(sub, -=) -ATOMIC64_OP(and, &=) -ATOMIC64_OP(or, |=) -ATOMIC64_OP(xor, ^=) #undef ATOMIC64_OPS +#define ATOMIC64_OPS(op, c_op) \ + ATOMIC64_OP(op, c_op) \ + ATOMIC64_FETCH_OP(op, c_op) + +ATOMIC64_OPS(and, &=) +ATOMIC64_OPS(or, |=) +ATOMIC64_OPS(xor, ^=) + +#undef ATOMIC64_OPS +#undef ATOMIC64_FETCH_OP #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP -- 2.20.1