Re: [PATCH 2/5] rust: sync: add const constructor for raw_spinlock_t

[Alice Ryhl]

On Tue, Jul 07, 2026 at 02:33:26PM +0100, Gary Guo wrote:
> On Tue Jul 7, 2026 at 2:17 PM BST, Alice Ryhl wrote:
> > On Wed, Jul 01, 2026 at 05:15:55PM +0100, Gary Guo wrote:
> >> On Tue Jun 23, 2026 at 4:38 PM BST, Alice Ryhl wrote:
> >> > The abstractions for pr_*_ratelimited! need to construct a global
> >> > `struct ratelimit_state`, which contains a `raw_spinlock_t` field. Thus,
> >> > add a const constructor for the `raw_spinlock_t` type.
> >> >
> >> > The SPINLOCK_OWNER_INIT constant isn't mirrored via a const helper
> >> > because bindgen generates a 'static mut' instead of a constant from the
> >> > pointer constant.,
> >> >
> >> > The __ARCH_SPIN_LOCK_UNLOCKED constant cannot be translated by bindgen
> >> > because it's a define for a struct without type annotations, so it's
> >> > explicitly declared in Rust.
> >> >
> >> > Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
> >
> >> > +/// Helper for creating a raw unlocked `bindings::raw_spinlock_t`.
> >> > +///
> >> > +/// For use in statics containing raw spinlocks.
> >> > +pub const fn raw_spin_lock_unlocked(name: &'static CStr) -> bindings::raw_spinlock_t {
> >> 
> >> These functions (incl. raw_lockdep_map) should really be private functions.
> >
> > Hmm, I think there could be cases where a driver needs to interact with
> > C code directly where this is useful. Even if use from drivers is
> > discouraged, I don't think we need to go out of our way to prevent it.
> > It's like the bindings crate.
> 
> I think a theoretical use case is not a justification for exporting such
> low-level functions. If such need arises, we can export them by then.

You're the one who wants extra characters ;)

I can make them private, but I say stuff like this because I've had to
change methods such as into_raw() or as_ptr() from private to public a
few times and I think it's annoying when I have to do that because it
brings changes that are otherwise driver-only to touch other random
files.

Alice