On Mon, Dec 9, 2024 at 11:44 AM Danilo Krummrich <dakr@xxxxxxxxxx> wrote: > > On Fri, Dec 06, 2024 at 03:01:18PM +0100, Alice Ryhl wrote: > > On Thu, Dec 5, 2024 at 3:16 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote: > > > > > > Implement the basic PCI abstractions required to write a basic PCI > > > driver. This includes the following data structures: > > > > > > The `pci::Driver` trait represents the interface to the driver and > > > provides `pci::Driver::probe` for the driver to implement. > > > > > > The `pci::Device` abstraction represents a `struct pci_dev` and provides > > > abstractions for common functions, such as `pci::Device::set_master`. > > > > > > In order to provide the PCI specific parts to a generic > > > `driver::Registration` the `driver::RegistrationOps` trait is implemented > > > by `pci::Adapter`. > > > > > > `pci::DeviceId` implements PCI device IDs based on the generic > > > `device_id::RawDevceId` abstraction. > > > > > > Co-developed-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxx> > > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxx> > > > Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx> > > > > > +/// The PCI device representation. > > > +/// > > > +/// A PCI device is based on an always reference counted `device:Device` instance. Cloning a PCI > > > +/// device, hence, also increments the base device' reference count. > > > +#[derive(Clone)] > > > +pub struct Device(ARef<device::Device>); > > > > It seems more natural for this to be a wrapper around > > `Opaque<bindings::pci_dev>`. Then you can have both &Device and > > ARef<Device> depending on whether you want to hold a refcount or not. > > Yeah, but then every bus device has to re-implement the refcount dance we > already have in `device::Device` for the underlying base `struct device`. > > I forgot to mention this in my previous reply to Boqun, but we even documented > it this way in `device::Device` [1]. > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/kernel/device.rs#n28 We could perhaps write a derive macro for AlwaysRefCounted that delegates to the inner type? That way, we can have the best of both worlds. Alice
