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| author |   Peter Zijlstra <peterz@infradead.org> | 2016-04-18 01:16:06 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-06-16 10:48:26 +0200 |
| commit | e898eb27ffd8b0ad6f4fd0b631559bc877c85444 (patch) | |
| tree | b9ee91a96640d1c139d43b3cb1cc8c226efcb938 /arch/metag/include/asm/atomic_lock1.h | |
| parent | locking/atomic, arch/m68k: Implement atomic_fetch_{add,sub,and,or,xor}() (diff) | |
| download | linux-dev-e898eb27ffd8b0ad6f4fd0b631559bc877c85444.tar.xz linux-dev-e898eb27ffd8b0ad6f4fd0b631559bc877c85444.zip | |
locking/atomic, arch/metag: Implement atomic_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) <peterz@infradead.org>
Acked-by: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.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-metag@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | arch/metag/include/asm/atomic_lock1.h | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/arch/metag/include/asm/atomic_lock1.h b/arch/metag/include/asm/atomic_lock1.h index 0295d9b8d5bf..6c1380a8a0d4 100644 --- a/arch/metag/include/asm/atomic_lock1.h +++ b/arch/metag/include/asm/atomic_lock1.h @@ -64,15 +64,40 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ return result; \ } -#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 result; \ + unsigned long flags; \ + \ + __global_lock1(flags); \ + result = v->counter; \ + fence(); \ + v->counter c_op i; \ + __global_unlock1(flags); \ + \ + return result; \ +} + +#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) + +ATOMIC_OPS(and, &=) +ATOMIC_OPS(or, |=) +ATOMIC_OPS(xor, ^=) + +#undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP |