Re: [PATCH 1/8] rust: device: introduce device::Internal

[Danilo Krummrich <dakr@kernel.org>]

On Tue, Jul 01, 2025 at 12:41:53PM +0200, Danilo Krummrich wrote:
> On Tue, Jul 01, 2025 at 11:26:47AM +0200, Greg KH wrote:
> > On Sat, Jun 21, 2025 at 09:43:27PM +0200, Danilo Krummrich wrote:
> > > Introduce an internal device context, which is semantically equivalent
> > > to the Core device context, but reserved for bus abstractions.
> > > 
> > > This allows implementing methods for the Device type, which are limited
> > > to be used within the core context of bus abstractions, i.e. restrict
> > > the availability for drivers.
> > > 
> > > Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> > > ---
> > >  rust/kernel/device.rs | 14 ++++++++++++++
> > >  1 file changed, 14 insertions(+)
> > > 
> > > diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
> > > index 665f5ceadecc..e9094d8322d5 100644
> > > --- a/rust/kernel/device.rs
> > > +++ b/rust/kernel/device.rs
> > > @@ -261,6 +261,10 @@ pub trait DeviceContext: private::Sealed {}
> > >  /// any of the bus callbacks, such as `probe()`.
> > >  pub struct Core;
> > >  
> > > +/// Semantically the same as [`Core`] but reserved for internal usage of the corresponding bus
> > > +/// abstraction.
> > > +pub struct Internal;
> > 
> > Naming is hard :)
> > 
> > As this is ONLY for the bus code to touch, why not call it Bus_Internal?
> 
> BusInternal is better indeed!

I now remember that I first wanted to go for CoreInternal, but then went for
just Internal, since it thought it was unnecessary to be more specific. But I
now think CoreInternal would have been the correct pick.

> > And can a driver touch this, or only the bus owner?
> 
> It is to prevent drivers from getting access to functions implemented for
> &Device<BusInternal>.