On Sat, Aug 30, 2025 at 12:42 AM Lyude Paul <ly...@redhat.com> wrote:
>
> For retrieving a pointer to the struct dma_resv for a given GEM object. We
> also introduce it in a new trait, BaseObjectPrivate, which we automatically
> implement for all gem objects and don't expose to users outside of the
> crate.
>
> Signed-off-by: Lyude Paul <ly...@redhat.com>
> ---
> rust/kernel/drm/gem/mod.rs | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> index ec36cd9ea69ed..f901d4263ee87 100644
> --- a/rust/kernel/drm/gem/mod.rs
> +++ b/rust/kernel/drm/gem/mod.rs
> @@ -186,6 +186,18 @@ fn create_mmap_offset(&self) -> Result<u64> {
>
> impl<T: IntoGEMObject> BaseObject for T {}
>
> +/// Crate-private base operations shared by all GEM object classes.
> +#[expect(unused)]
> +pub(crate) trait BaseObjectPrivate: IntoGEMObject {
> + /// Return a pointer to this object's dma_resv.
> + fn raw_dma_resv(&self) -> *mut bindings::dma_resv {
> + // SAFETY: `as_gem_obj()` always returns a valid pointer to the base
> DRM gem object
> + unsafe { (*self.as_raw()).resv }
> + }
> +}
> +
> +impl<T: IntoGEMObject> BaseObjectPrivate for T {}
I think this use of a trait is somewhat of an antipattern. I would
probably have suggested a standalone method instead.
Alice
