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

[Rob Herring]

On Wed, Mar 26, 2025 at 06:13:41PM +0100, Remo Senekowitsch wrote:
> From: "Rob Herring (Arm)" <robh@xxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxxx/
> 
> Suggested-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>

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
>