Re: [PATCH net-next v2 1/6] rust: time: Implement PartialEq and PartialOrd for Ktime

[Fiona Behrens]

On 5 Oct 2024, at 14:25, FUJITA Tomonori wrote:

> Implement PartialEq and PartialOrd trait for Ktime by using C's
> ktime_compare function so two Ktime instances can be compared to
> determine whether a timeout is met or not.

Why is this only PartialEq/PartialOrd? Could we either document why or implement Eq/Ord as well?

>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxx>
> ---
>  rust/helpers/helpers.c |  1 +
>  rust/helpers/time.c    |  8 ++++++++
>  rust/kernel/time.rs    | 22 ++++++++++++++++++++++
>  3 files changed, 31 insertions(+)
>  create mode 100644 rust/helpers/time.c
>
> diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
> index 30f40149f3a9..c274546bcf78 100644
> --- a/rust/helpers/helpers.c
> +++ b/rust/helpers/helpers.c
> @@ -21,6 +21,7 @@
>  #include "slab.c"
>  #include "spinlock.c"
>  #include "task.c"
> +#include "time.c"
>  #include "uaccess.c"
>  #include "wait.c"
>  #include "workqueue.c"
> diff --git a/rust/helpers/time.c b/rust/helpers/time.c
> new file mode 100644
> index 000000000000..d6f61affb2c3
> --- /dev/null
> +++ b/rust/helpers/time.c
> @@ -0,0 +1,8 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/ktime.h>
> +
> +int rust_helper_ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
> +{
> +	return ktime_compare(cmp1, cmp2);
> +}
> diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs
> index e3bb5e89f88d..c40105941a2c 100644
> --- a/rust/kernel/time.rs
> +++ b/rust/kernel/time.rs
> @@ -81,3 +81,25 @@ fn sub(self, other: Ktime) -> Ktime {
>          }
>      }
>  }
> +
> +impl PartialEq for Ktime {
> +    #[inline]
> +    fn eq(&self, other: &Self) -> bool {
> +        // SAFETY: FFI call.
> +        let ret = unsafe { bindings::ktime_compare(self.inner, other.inner) };
> +        ret == 0
> +    }
> +}
> +
> +impl PartialOrd for Ktime {
> +    #[inline]
> +    fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
> +        // SAFETY: FFI call.
> +        let ret = unsafe { bindings::ktime_compare(self.inner, other.inner) };
> +        match ret {
> +            0 => Some(core::cmp::Ordering::Equal),
> +            x if x < 0 => Some(core::cmp::Ordering::Less),
> +            _ => Some(core::cmp::Ordering::Greater),
> +        }
> +    }
> +}
> -- 
> 2.34.1