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locking/atomic, arch/parisc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()

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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>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2016-04-18 01:16:05 +02:00 committed by Ingo Molnar
parent f8d638e28d
commit e5857a6ed6
1 changed files with 57 additions and 8 deletions
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65
arch/parisc/include/asm/atomic.h
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@ -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