Re: [PATCH v2 2/5] rust: dma: add DMA addressing capabilities

[Daniel Almeida]

> On 16 Jul 2025, at 14:32, Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx> wrote:
> 
> Hi Danilo,
> 
>> +    #[inline]
>> +    pub const fn new(n: usize) -> Result<Self> {
>> +        Ok(Self(match n {
>> +            0 => 0,
>> +            1..=64 => u64::MAX >> (64 - n),
>> +            _ => return Err(EINVAL),
>> +        }))
>> +    }
>> +
> 
> Isn’t this equivalent to genmask_u64(0..=n) ? See [0].
> 
> You should also get a compile-time failure if n is out of bounds by default using
> genmask.
> 
> — Daniel
> 
> [0]: https://lore.kernel.org/rust-for-linux/20250714-topics-tyr-genmask2-v9-1-9e6422cbadb6@xxxxxxxxxxxxx/#r

Or genmask_u64(0..=n-1), if we disregard the previous off-by-one error

— Daniel