Re: [PATCH v5 03/20] rust: io: restrict untyped IO access and `register!` to `Region`

[sashiko-bot@kernel.org]

> Currently the `Io` trait exposes a bunch of untyped IO accesses, but if the
> `Io` region itself is typed, then it might be weird to have
> 
>     let io: Mmio<u32> = /* ... */;
>     io.read8(1);
> 
> while not unsound, it is surely strange. Thus, restrict the untyped methods
> and also the register macro to `Region` type only.
> 
> Implement it by adding a generic type to `IoLoc` indicating allowed base
> types. This also paves the way to add typed register blocks in the future;
> for example, we could use this mechanism to block driver A's `register!()`
> generated macro from being used on driver B's MMIO. The same mechanism
> could be used for relative IO registers. These are future opportunities,
> and for now restrict everything to require `IoLoc<Region<SIZE>, _>`.
> 
> Suggested-by: Alexandre Courbot <acourbot@nvidia.com>
> Link: https://lore.kernel.org/rust-for-linux/DHLB3RO3OSF5.2R7F27U99BKLN@nvidia.com/
> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
> Signed-off-by: Gary Guo <gary@garyguo.net>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260626-io_projection-v5-0-d0961471ae50@garyguo.net?part=3