Re: [PATCH 3/7] rust: io: add read-only and write-only views

[sashiko-bot@kernel.org]

> An I/O view can always be both read and written, as long as its backend
> supports both directions. The I/O API has no view that only allows the
> accesses the hardware or firmware permits, such as a status register
> that must not be written or a doorbell that must not be read.
> 
> Add `ReadOnly` and `WriteOnly`, which wrap a view of any backend, and
> their backends `ReadOnlyBackend` and `WriteOnlyBackend`. A read-only
> backend implements `IoReadable` and `IoCopyReadable` where the wrapped
> backend does, by forwarding to it, and implements neither `IoWritable`
> nor `IoCopyWritable`, so the write methods of `Io` do not compile on a
> `ReadOnly` view. `WriteOnly` is the converse. Views projected from a
> wrapped view stay wrapped, and the wrapped view cannot be retrieved.
> 
> Add `Io::read_only` and `Io::write_only` to create them from any view or
> I/O handle.
> 
> There are no users yet. Register locations with an access mode will be
> the first, in a following patch.
> 
> Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>

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

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261015-io-access-modes-v1-0-93611b84b5e3@collabora.com?part=3