Re: [PATCH v4 09/20] rust: io: use view types instead of addresses for `Io`

[sashiko-bot@kernel.org]

> Currently, `io_read` and `io_write` methods require the exact type of `Io`
> plus an address. This means that they need to be monomorphized for each
> different `Io` instance. This also means that multiple I/O implementors for
> the same I/O kind needs to duplicate implementation (e.g. `Mmio` and
> `MmioOwned`).
> 
> Create a new `IoBackend` trait and define these operations on it instead.
> The operations are just going to receive a view type and operate on them.
> This has the additional advantage that the invariants can be moved from the
> trait (and guaranteed via `unsafe`) to type invariants on the canonical
> view types of the backends, so `io_read` and `io_write` can be safe.
> 
> Note that view type is needed; addresses are insufficient in this
> designk, as they do not carry sufficient information. For example,
> `ConfigSpace` needs `&pci::Device` in addition to the address.
> 
> 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/20260611-io_projection-v4-0-1f7224b02dcb@garyguo.net?part=9