Re: [PATCH v2 3/4] rust: sync: atomic: Add i8/i16 load and store support

[Boqun Feng <boqun.feng@gmail.com>]

On Tue, Dec 09, 2025 at 08:14:56AM +0900, FUJITA Tomonori wrote:
> On Mon, 08 Dec 2025 12:08:23 +0900
> "Alexandre Courbot" <acourbot@nvidia.com> wrote:
> 
> > On Mon Nov 17, 2025 at 9:10 AM JST, FUJITA Tomonori wrote:
> >> Add atomic operation support for i8 and i16 types using volatile
> >> read/write and smp_load_acquire/smp_store_release helpers.
> >>
> >> Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
> >> ---
> >>  rust/kernel/sync/atomic/internal.rs  | 48 ++++++++++++++++++++++++++++
> >>  rust/kernel/sync/atomic/predefine.rs | 14 +++++++-
> >>  2 files changed, 61 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/rust/kernel/sync/atomic/internal.rs b/rust/kernel/sync/atomic/internal.rs
> >> index 6fdd8e59f45b..4c9f4f76dbdf 100644
> >> --- a/rust/kernel/sync/atomic/internal.rs
> >> +++ b/rust/kernel/sync/atomic/internal.rs
> >> @@ -263,3 +263,51 @@ fn fetch_add[acquire, release, relaxed](a: &AtomicRepr<Self>, v: Self::Delta) ->
> >>          }
> >>      }
> >>  );
> >> +
> >> +impl private::Sealed for i8 {}
> >> +impl private::Sealed for i16 {}
> >> +
> >> +impl AtomicImpl for i8 {
> >> +    type Delta = Self;
> >> +}
> >> +
> >> +impl AtomicImpl for i16 {
> >> +    type Delta = Self;
> >> +}
> > 
> > I'd suggest putting these next to the impls for `i32` and `i64`, for clarity.
> 
> I'm fine with either. Boqun, what do you think?
> 

I think we should put them together.

> The reason I didn't put i8/i16 next to i32/i64 is that I assume that
> i8/i16 won't support all the methods supported by i32/i64. I thought
> keeping them separate would make that distinction clearer.
> 

Even if that's true, it still make sense to put the impl blocks with
i32 and i64.

Regards,
Boqun