On Wed, Jul 28, 2021 at 02:58:35PM +0200, Peter Zijlstra wrote:
> Urgh.. please start from something like the below and then run:
>
> scripts/atomic/gen-atomics.sh
>
> The below isn't quite right, because it'll use try_cmpxchg() for
> atomic_andnot_or(), which by being a void atomic should be _relaxed. I'm
> not entirely sure how to make that happen in a hurry.
>
Of note, the below is on top of tip/locking/core, which includes a bunch
of atomic work from Mark.
> ---
>
> diff --git a/scripts/atomic/atomics.tbl b/scripts/atomic/atomics.tbl
> index fbee2f6190d9..3aaa0caa6b2d 100755
> --- a/scripts/atomic/atomics.tbl
> +++ b/scripts/atomic/atomics.tbl
> @@ -39,3 +39,4 @@ inc_not_zero b v
> inc_unless_negative b v
> dec_unless_positive b v
> dec_if_positive i v
> +andnot_or vF v i:m i:o
> diff --git a/scripts/atomic/fallbacks/andnot_or b/scripts/atomic/fallbacks/andnot_or
> new file mode 100644
> index 000000000000..f50e78d6c53a
> --- /dev/null
> +++ b/scripts/atomic/fallbacks/andnot_or
> @@ -0,0 +1,15 @@
> +cat <<EOF
> +static __always_inline ${ret}
> +arch_${atomic}_${pfx}andnot_or${sfx}${order}(${atomic}_t *v, ${int} m, ${int} o)
> +{
> + ${retstmt}({
> + ${int} N, O = atomic_read(v);
> + do {
> + N = O;
> + N &= ~m;
> + N |= o;
> + } while (!arch_${atomic}_try_cmpxchg${order}(v, &O, N));
> + O;
> + });
> +}
> +EOF
> diff --git a/scripts/atomic/fallbacks/fetch_andnot_or b/scripts/atomic/fallbacks/fetch_andnot_or
> deleted file mode 100644
> index e69de29bb2d1..000000000000
>
