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]> --- drivers/gpu/drm/nova/driver.rs | 7 +++++-- rust/kernel/auxiliary.rs | 14 ++++++++------ samples/rust/rust_driver_auxiliary.rs | 7 +++++-- 3 files changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/nova/driver.rs b/drivers/gpu/drm/nova/driver.rs index 08136ec0bccb..1d73c595dda4 100644 --- a/drivers/gpu/drm/nova/driver.rs +++ b/drivers/gpu/drm/nova/driver.rs @@ -51,10 +51,13 @@ pub(crate) struct NovaData { impl auxiliary::Driver for NovaDriver { type IdInfo = (); - type Data = Self; + type Data<'bound> = Self; const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE; - fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> { + fn probe<'bound>( + adev: &'bound auxiliary::Device<Core>, + _info: &'bound Self::IdInfo, + ) -> impl PinInit<Self, Error> + 'bound { let data = try_pin_init!(NovaData { adev: adev.into() }); let drm = drm::Device::<Self>::new(adev.as_ref(), data)?; diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs index c6d97c95c3e7..3f1e2966c03a 100644 --- a/rust/kernel/auxiliary.rs +++ b/rust/kernel/auxiliary.rs @@ -46,7 +46,7 @@ // - `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::auxiliary_driver; - type DriverData<'bound> = T::Data; + type DriverData<'bound> = T::Data<'bound>; const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver); } @@ -112,7 +112,7 @@ extern "C" fn remove_callback(adev: *mut bindings::auxiliary_device) { // SAFETY: `remove_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 { adev.as_ref().drvdata_borrow::<T::Data>() }; + let data = unsafe { adev.as_ref().drvdata_borrow::<T::Data<'_>>() }; T::unbind(adev, data); } @@ -203,7 +203,7 @@ 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>; @@ -211,8 +211,10 @@ pub trait Driver { /// Auxiliary driver probe. /// /// Called when an auxiliary device is matches a corresponding driver. - fn probe(dev: &Device<device::Core>, id_info: &Self::IdInfo) - -> impl PinInit<Self::Data, Error>; + fn probe<'bound>( + dev: &'bound Device<device::Core>, + id_info: &'bound Self::IdInfo, + ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound; /// Auxiliary driver unbind. /// @@ -224,7 +226,7 @@ fn probe(dev: &Device<device::Core>, id_info: &Self::IdInfo) /// operations to gracefully tear down the device. /// /// Otherwise, release operations for driver resources should be performed in `Drop`. - fn unbind(dev: &Device<device::Core>, this: Pin<&Self::Data>) { + fn unbind<'bound>(dev: &'bound Device<device::Core>, this: Pin<&'bound Self::Data<'bound>>) { let _ = (dev, this); } } diff --git a/samples/rust/rust_driver_auxiliary.rs b/samples/rust/rust_driver_auxiliary.rs index 2f57912fe87f..972a3d5b25e7 100644 --- a/samples/rust/rust_driver_auxiliary.rs +++ b/samples/rust/rust_driver_auxiliary.rs @@ -31,11 +31,14 @@ impl auxiliary::Driver for AuxiliaryDriver { type IdInfo = (); - type Data = Self; + type Data<'bound> = Self; const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE; - fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> { + fn probe<'bound>( + adev: &'bound auxiliary::Device<Core>, + _info: &'bound Self::IdInfo, + ) -> impl PinInit<Self, Error> + 'bound { dev_info!( adev, "Probing auxiliary driver for auxiliary device with id={}\n", -- 2.54.0
