Mainline UML Rust stable io.rs unused imports

Mainline UML Rust stable io.rs unused imports

[Miguel Ojeda]

Hi all,

In mainline and next, for UML with Rust stable (but not with Rust
minimum), I am seeing:

      RUSTC L rust/kernel.o - due to target missing
    error: unused import: `define_read`
       --> rust/kernel/io.rs:229:16
        |
    229 | pub(crate) use define_read;
        |                ^^^^^^^^^^^
        |
        = note: `-D unused-imports` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(unused_imports)]`

    error: unused import: `define_write`
       --> rust/kernel/io.rs:262:16
        |
    262 | pub(crate) use define_write;
        |                ^^^^^^^^^^^

Cheers,
Miguel

Re: Mainline UML Rust stable io.rs unused imports

[Johannes Berg]

On Sun, 2026-02-15 at 13:47 +0100, Miguel Ojeda wrote:
> Hi all,
> 
> In mainline and next, for UML with Rust stable (but not with Rust
> minimum), I am seeing:
> 
>       RUSTC L rust/kernel.o - due to target missing
>     error: unused import: `define_read`
>        --> rust/kernel/io.rs:229:16
>         |
>     229 | pub(crate) use define_read;
>         |                ^^^^^^^^^^^
>         |
>         = note: `-D unused-imports` implied by `-D warnings`
>         = help: to override `-D warnings` add `#[allow(unused_imports)]`
> 
>     error: unused import: `define_write`
>        --> rust/kernel/io.rs:262:16
>         |
>     262 | pub(crate) use define_write;
>         |                ^^^^^^^^^^^

Not sure I understand, the cfg() seems to only be fore 64-bit, but it
_is_ possible to build UML without IO accessors at all, since it's just
virtual, but I don't see how that would reflect in io.rs.

Not sure I can say anything else about it, sorry.

johannes

Re: Mainline UML Rust stable io.rs unused imports

[Danilo Krummrich]

On Sun Feb 15, 2026 at 1:47 PM CET, Miguel Ojeda wrote:
> Hi all,
>
> In mainline and next, for UML with Rust stable (but not with Rust
> minimum), I am seeing:

I think the problem is not UML specific, it is about define_read!() and
define_write!() being crate public, while the only user is PCI.

So, if CONFIG_PCI=n, we get this warning.

I will send a fix soon.

Thanks for reporting!

- Danilo

>
>       RUSTC L rust/kernel.o - due to target missing
>     error: unused import: `define_read`
>        --> rust/kernel/io.rs:229:16
>         |
>     229 | pub(crate) use define_read;
>         |                ^^^^^^^^^^^
>         |
>         = note: `-D unused-imports` implied by `-D warnings`
>         = help: to override `-D warnings` add `#[allow(unused_imports)]`
>
>     error: unused import: `define_write`
>        --> rust/kernel/io.rs:262:16
>         |
>     262 | pub(crate) use define_write;
>         |                ^^^^^^^^^^^
>
> Cheers,
> Miguel

Re: Mainline UML Rust stable io.rs unused imports

[Danilo Krummrich]

On Mon Feb 16, 2026 at 11:34 AM CET, Danilo Krummrich wrote:
> I will send a fix soon.

https://lore.kernel.org/driver-core/20260216131534.65008-1-dakr@kernel.org/