Messages in this thread Patch in this message | | | Date | Thu, 3 Feb 2022 15:35:30 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH] atomics: fix atomic64_{read_acquire,set_release} fallbacks |
| |
On Thu, Feb 03, 2022 at 02:38:48PM +0000, Mark Rutland wrote: > @@ -1258,7 +1272,16 @@ arch_atomic_dec_if_positive(atomic_t *v) > static __always_inline s64 > arch_atomic64_read_acquire(const atomic64_t *v) > { > - return smp_load_acquire(&(v)->counter); > + s64 ret; > + > + if (__native_word(atomic64_t)) { > + ret = smp_load_acquire(&(v)->counter); > + } else { > + ret = arch_atomic_read(v);
Ard pointed out on IRC that this is bogus, and should be using arch_atomic64_read() ...
> + __atomic_acquire_fence(); > + } > + > + return ret; > } > #define arch_atomic64_read_acquire arch_atomic64_read_acquire > #endif > @@ -1267,7 +1290,12 @@ arch_atomic64_read_acquire(const atomic64_t *v) > static __always_inline void > arch_atomic64_set_release(atomic64_t *v, s64 i) > { > - smp_store_release(&(v)->counter, i); > + if (__native_word(atomic64_t)) { > + smp_store_release(&(v)->counter, i); > + } else { > + __atomic_release_fence(); > + arch_atomic_set(v, i);
... and arch_atomic64_set() ...
> + } > } > #define arch_atomic64_set_release arch_atomic64_set_release > #endif > @@ -2358,4 +2386,4 @@ arch_atomic64_dec_if_positive(atomic64_t *v) > #endif > > #endif /* _LINUX_ATOMIC_FALLBACK_H */ > -// cca554917d7ea73d5e3e7397dd70c484cad9b2c4 > +// ba488b6398359cb776d457971f30cef78d0d36dc > diff --git a/scripts/atomic/fallbacks/read_acquire b/scripts/atomic/fallbacks/read_acquire > index 803ba7561076..7b8b87143c0c 100755 > --- a/scripts/atomic/fallbacks/read_acquire > +++ b/scripts/atomic/fallbacks/read_acquire > @@ -2,6 +2,15 @@ cat <<EOF > static __always_inline ${ret} > arch_${atomic}_read_acquire(const ${atomic}_t *v) > { > - return smp_load_acquire(&(v)->counter); > + ${int} ret; > + > + if (__native_word(${atomic}_t)) { > + ret = smp_load_acquire(&(v)->counter); > + } else { > + ret = arch_atomic_read(v);
... because this should be arch_${atomic}_read() ...
> + __atomic_acquire_fence(); > + } > + > + return ret; > } > EOF > diff --git a/scripts/atomic/fallbacks/set_release b/scripts/atomic/fallbacks/set_release > index 86ede759f24e..5f692db3ce29 100755 > --- a/scripts/atomic/fallbacks/set_release > +++ b/scripts/atomic/fallbacks/set_release > @@ -2,6 +2,11 @@ cat <<EOF > static __always_inline void > arch_${atomic}_set_release(${atomic}_t *v, ${int} i) > { > - smp_store_release(&(v)->counter, i); > + if (__native_word(${atomic}_t)) { > + smp_store_release(&(v)->counter, i); > + } else { > + __atomic_release_fence(); > + arch_atomic_set(v, i);
... and this should be arch_${atomic}_set().
I'll spin a v2 with that corrected.
Thanks, Mark.
| |