On Wed, Jul 28, 2021 at 03:16:54PM +0200, Peter Zijlstra wrote:
> On Wed, Jul 28, 2021 at 02:58:35PM +0200, Peter Zijlstra wrote:
> > 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.
> >
> > ---
>
> This seems to do the trick.
>
Mark suggested this, which is probably nicer still.
---
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..0fb3a728c0ff
--- /dev/null
+++ b/scripts/atomic/fallbacks/andnot_or
@@ -0,0 +1,24 @@
+local try_order=${order}
+
+#
+# non-value returning atomics are implicity relaxed
+#
+if [ -z "${retstmt}" ]; then
+ try_order="_relaxed"
+fi
+
+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${try_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
