Re: [PATCH 02/10] rust: Add an Integer trait

Rob Herring
2025-03-26T20:00:32Z

On Wed, Mar 26, 2025 at 06:13:41PM +0100, Remo Senekowitsch wrote:
> From: "Rob Herring (Arm)" <robh@kernel.org>
>
> Add an "Integer" trait similar to crate::num::Integer. This is useful
> for implementing generic methods which operate on different sizes of
> integers. One example is reading DT/ACPI firmware properties.
>
> This was originally proposed by Alice Ryhl[1].
>
> [1] https://lore.kernel.org/rust-for-linux/CAH5fLgiXPZqKpWSSNdx-Ww-E9h2tOLcF3_8Y4C_JQ0eU8EMwFw@mail.gmail.com/
>
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

This needs your Signed-off-by too because you are sending it.

> ---
> rust/kernel/types.rs | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
> index 2bbaab83b..21647b7ba 100644
> --- a/rust/kernel/types.rs
> +++ b/rust/kernel/types.rs
> @@ -3,10 +3,11 @@
> //! Kernel types.
>
> use crate::init::{self, PinInit};
> +use crate::transmute::{AsBytes, FromBytes};
> use core::{
> cell::UnsafeCell,
> marker::{PhantomData, PhantomPinned},
> - mem::{ManuallyDrop, MaybeUninit},
> + mem::{size_of, ManuallyDrop, MaybeUninit},
> ops::{Deref, DerefMut},
> ptr::NonNull,
> };
> @@ -553,6 +554,25 @@ pub enum Either<L, R> {
> Right(R),
> }
>
> +/// Trait defined for all integer types similar to `crate::num::Integer`
> +pub trait Integer: FromBytes + AsBytes + Copy {
> + /// Size of the integer in bytes
> + const SIZE: usize;
> +}
> +
> +macro_rules! impl_int {
> + ($($typ:ty),* $(,)?) => {$(
> + impl Integer for $typ {
> + const SIZE: usize = size_of::<Self>();
> + }
> + )*};
> +}
> +
> +impl_int! {
> + u8, u16, u32, u64, usize,
> + i8, i16, i32, i64, isize,
> +}
> +
> /// Zero-sized type to mark types not [`Send`].
> ///
> /// Add this type as a field to your struct if your type should not be sent to a different task.
> --
> 2.49.0
>