Add a 'bound lifetime to the associated Data, changing type Data to type Data<'bound>.
This allows the driver's bus device private data to capture the device / driver bound lifetime; device resources can be stored directly by reference rather than requiring Devres. The probe() and unbind() callbacks thus gain a 'bound lifetime parameter on the methods themselves; avoiding a global lifetime on the trait impl. Existing drivers set type Data<'bound> = Self, preserving the current behavior. Signed-off-by: Danilo Krummrich <[email protected]> --- rust/kernel/usb.rs | 39 +++++++++++++++++++-------------- samples/rust/rust_driver_usb.rs | 14 ++++++------ 2 files changed, 30 insertions(+), 23 deletions(-) diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs index 995221d327b8..ec67e4d2416f 100644 --- a/rust/kernel/usb.rs +++ b/rust/kernel/usb.rs @@ -41,7 +41,7 @@ // - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`. unsafe impl<T: Driver> driver::DriverLayout for Adapter<T> { type DriverType = bindings::usb_driver; - type DriverData<'bound> = T::Data; + type DriverData<'bound> = T::Data<'bound>; const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver); } @@ -110,7 +110,7 @@ extern "C" fn disconnect_callback(intf: *mut bindings::usb_interface) { // SAFETY: `disconnect_callback` is only ever called after a successful call to // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called // and stored a `Pin<KBox<T::Data>>`. - let data = unsafe { dev.drvdata_borrow::<T::Data>() }; + let data = unsafe { dev.drvdata_borrow::<T::Data<'_>>() }; T::disconnect(intf, data); } @@ -287,18 +287,22 @@ macro_rules! usb_device_table { /// /// impl usb::Driver for MyDriver { /// type IdInfo = (); -/// type Data = Self; +/// type Data<'bound> = Self; /// const ID_TABLE: usb::IdTable<Self::IdInfo> = &USB_TABLE; /// -/// fn probe( -/// _interface: &usb::Interface<Core>, -/// _id: &usb::DeviceId, -/// _info: &Self::IdInfo, -/// ) -> impl PinInit<Self::Data, Error> { +/// fn probe<'bound>( +/// _interface: &'bound usb::Interface<Core>, +/// _id: &'bound usb::DeviceId, +/// _info: &'bound Self::IdInfo, +/// ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound { /// Err(ENODEV) /// } /// -/// fn disconnect(_interface: &usb::Interface<Core>, _data: Pin<&Self::Data>) {} +/// fn disconnect<'bound>( +/// _interface: &'bound usb::Interface<Core>, +/// _data: Pin<&'bound Self::Data<'bound>>, +/// ) { +/// } /// } ///``` pub trait Driver { @@ -306,7 +310,7 @@ pub trait Driver { type IdInfo: 'static; /// The type of the driver's bus device private data. - type Data; + type Data<'bound>: 'bound; /// The table of device ids supported by the driver. const ID_TABLE: IdTable<Self::IdInfo>; @@ -315,16 +319,19 @@ pub trait Driver { /// /// Called when a new USB interface is bound to this driver. /// Implementers should attempt to initialize the interface here. - fn probe( - interface: &Interface<device::Core>, - id: &DeviceId, - id_info: &Self::IdInfo, - ) -> impl PinInit<Self::Data, Error>; + fn probe<'bound>( + interface: &'bound Interface<device::Core>, + id: &'bound DeviceId, + id_info: &'bound Self::IdInfo, + ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound; /// USB driver disconnect. /// /// Called when the USB interface is about to be unbound from this driver. - fn disconnect(interface: &Interface<device::Core>, data: Pin<&Self::Data>); + fn disconnect<'bound>( + interface: &'bound Interface<device::Core>, + data: Pin<&'bound Self::Data<'bound>>, + ); } /// A USB interface. diff --git a/samples/rust/rust_driver_usb.rs b/samples/rust/rust_driver_usb.rs index 5942e4b01fd8..4403bd758db9 100644 --- a/samples/rust/rust_driver_usb.rs +++ b/samples/rust/rust_driver_usb.rs @@ -26,21 +26,21 @@ struct SampleDriver { impl usb::Driver for SampleDriver { type IdInfo = (); - type Data = Self; + type Data<'bound> = Self; const ID_TABLE: usb::IdTable<Self::IdInfo> = &USB_TABLE; - fn probe( - intf: &usb::Interface<Core>, - _id: &usb::DeviceId, - _info: &Self::IdInfo, - ) -> impl PinInit<Self, Error> { + fn probe<'bound>( + intf: &'bound usb::Interface<Core>, + _id: &'bound usb::DeviceId, + _info: &'bound Self::IdInfo, + ) -> impl PinInit<Self, Error> + 'bound { let dev: &device::Device<Core> = intf.as_ref(); dev_info!(dev, "Rust USB driver sample probed\n"); Ok(Self { _intf: intf.into() }) } - fn disconnect(intf: &usb::Interface<Core>, _data: Pin<&Self>) { + fn disconnect<'bound>(intf: &'bound usb::Interface<Core>, _data: Pin<&'bound Self>) { let dev: &device::Device<Core> = intf.as_ref(); dev_info!(dev, "Rust USB driver sample disconnected\n"); } -- 2.54.0
