[PATCH -v2 18/33] locking,parisc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
From: Peter Zijlstra <peterz@infradead.org>
Date: 2016-05-31 10:29:54
Also in:
lkml
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) <peterz@infradead.org> --- arch/parisc/include/asm/atomic.h | 65 ++++++++++++++++++++++++++++++++++----- 1 file changed, 57 insertions(+), 8 deletions(-)
--- a/arch/parisc/include/asm/atomic.h
+++ b/arch/parisc/include/asm/atomic.h@@ -121,16 +121,41 @@ static __inline__ int atomic_##op##_retu 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##_re 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