Re: [PATCH v2 1/2] rust: introduce abstractions for fwctlg

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Jan 28, 2026 at 05:35:04PM +0100, Danilo Krummrich wrote:
> On Wed Jan 28, 2026 at 4:56 PM CET, Jason Gunthorpe wrote:
> > On Wed, Jan 28, 2026 at 04:49:07PM +0100, Danilo Krummrich wrote:
> >
> >> 	        // Initialize the `data` initializer within the memory pointed
> >> 	        // to by `raw_data`.
> >> 	        unsafe { data.__pinned_init(raw_data) }.inspect_err(|_| {
> >
> >> So, essentially the driver passes an initializer of its private data and we
> >> "write" this initializer into the extra memory allocated with
> >> _fwctl_alloc_device().
> >
> > This all seems like the right way to do it!
> >
> > My only remark it that it still doesn't give an opportunity to call a
> > function between init and register.
> 
> You would, from a driver side it would look like this:
> 
> 	#[pin_data]
> 	struct MyDriver {
> 	    #[pin]
> 	    _reg: Devres<fwctl::Registration>,
> 	    fwctl: ARef<fwctl::Device>,
> 	}
> 
> 	#[pin_data]
> 	struct FwctlData {
> 	    #[pin]
> 	    foo: Mutex<Foo>,
> 	    ...,
> 	}
> 
> 	impl pci::Driver for MyDriver {
> 	    fn probe(
> 	        pdev: &pci::Device<Core>,
> 	        _info: &Self::IdInfo,
> 	    ) -> impl PinInit<Self, Error> {
> 	        let fwctl = fwctl::Device::new(
> 	            pdev.as_ref(),
> 	            try_pin_init!(FwctlData {
> 	                foo <- mutex_new!(Foo::new()),
> 	                ...,
> 	            }),
> 	        )?;
> 
> 	        // Let's do something with the `fwctl::Device` before we
> 	        // register it.
> 	        fwctl.do_stuff();
> 
> 	        try_pin_init!(Self {
> 	            // We could omit this and instead provide
> 	            // `fwctl::Registration::register()`, which does only return
> 	            // a `Result` and keeps the `fwct::Device` registered until
> 	            // driver unbind.
> 	            _reg <- fwctl::Registration::new(pdev.as_ref(), fwctl);
> 	            fwctl,
> 	        })
> 	    }
> 	}

Okay it is fine by me, Zi did you get all this?

Jason