Re: [PATCH 3/6] rust: hrtimer: Add HrTimerClockBase

[Andreas Hindborg <a.hindborg@kernel.org>]

"Lyude Paul" <lyude@redhat.com> writes:

> This adds a simple wrapper for the hrtimer_clock_base struct, which can be
> obtained from a HrTimerCallbackContext. We'll use this in the next commit to
> add a function to acquire the current time for the base clock driving a
> hrtimer.
>
> Signed-off-by: Lyude Paul <lyude@redhat.com>
> ---
>  rust/kernel/time/hrtimer.rs | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
>
> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
> index c92b10524f892..f633550882247 100644
> --- a/rust/kernel/time/hrtimer.rs
> +++ b/rust/kernel/time/hrtimer.rs
> @@ -165,6 +165,29 @@ pub(crate) unsafe fn raw_cancel(this: *const Self) -> bool {
>      }
>  }
>
> +/// The timer base for a specific clock.
> +///
> +/// # Invariants
> +///
> +/// The layout of this type is equivalent to that of `struct hrtimer_clock_base`.
> +#[repr(transparent)]
> +pub struct HrTimerClockBase(Opaque<bindings::hrtimer_clock_base>);
> +
> +impl HrTimerClockBase {
> +    /// Retrieve a reference to a [`HrTimerClockBase`] from `ptr`.
> +    ///
> +    /// # Safety
> +    ///
> +    /// `ptr` must point to a live `struct hrtimer_clock_base`.
> +    unsafe fn from_raw<'a>(ptr: *mut bindings::hrtimer_clock_base) -> &'a Self {
> +        // SAFETY:
> +        // - `ptr` is guaranteed to point to a live `struct hrtimer_clock_base` by our safety
> +        //   contract.

I think this next one should be an `// INVARIANT:` comment.


Best regards,
Andreas Hindborg