On Sun May 17, 2026 at 1:00 AM BST, Danilo Krummrich wrote:
> 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/nova-core/driver.rs | 9 ++++++---
> rust/kernel/pci.rs | 24 +++++++++++++-----------
> samples/rust/rust_dma.rs | 7 +++++--
> samples/rust/rust_driver_auxiliary.rs | 7 +++++--
> samples/rust/rust_driver_pci.rs | 7 +++++--
> 5 files changed, 34 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
> index 699e27046c93..fe4eafe1ebf0 100644
> --- a/drivers/gpu/nova-core/driver.rs
> +++ b/drivers/gpu/nova-core/driver.rs
> @@ -74,10 +74,13 @@ pub(crate) struct NovaCore {
>
> impl pci::Driver for NovaCore {
> type IdInfo = ();
> - type Data = Self;
> + type Data<'bound> = Self;
> const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
>
> - fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl
> PinInit<Self, Error> {
> + fn probe<'bound>(
> + pdev: &'bound pci::Device<Core>,
This is technically incorrect, as the `Device<Core>` only lives as long as the
callback. Having `'bound` would be incorrect.
This can either be addressed via
pdev: &pci::Device<Core>, pdev_bound: &'bound pci::Device<Bound>, ...
or perhaps by adding a lifetime to `Core<'_>`
pdev: &'bound pci::Device<Core<'_>>,
Best,
Gary
> + _info: &'bound Self::IdInfo,
> + ) -> impl PinInit<Self, Error> + 'bound {
> pin_init::pin_init_scope(move || {
> dev_dbg!(pdev, "Probe Nova Core GPU driver.\n");
>
> @@ -109,7 +112,7 @@ fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo)
> -> impl PinInit<Self, E
> })
> }
>
> - fn unbind(pdev: &pci::Device<Core>, this: Pin<&Self>) {
> + fn unbind<'bound>(pdev: &'bound pci::Device<Core>, this: Pin<&'bound
> Self>) {
> this.gpu.unbind(pdev.as_ref());
> }
> }
> diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
> index c06ac3fb2a64..8060861199d4 100644
> --- a/rust/kernel/pci.rs
> +++ b/rust/kernel/pci.rs
> @@ -64,7 +64,7 @@
> // - `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::pci_driver;
> - type DriverData<'bound> = T::Data;
> + type DriverData<'bound> = T::Data<'bound>;
> const DEVICE_DRIVER_OFFSET: usize =
> core::mem::offset_of!(Self::DriverType, driver);
> }
>
> @@ -130,7 +130,7 @@ extern "C" fn remove_callback(pdev: *mut
> bindings::pci_dev) {
> // 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 { pdev.as_ref().drvdata_borrow::<T::Data>() };
> + let data = unsafe { pdev.as_ref().drvdata_borrow::<T::Data<'_>>() };
>
> T::unbind(pdev, data);
> }
> @@ -279,13 +279,13 @@ macro_rules! pci_device_table {
> ///
> /// impl pci::Driver for MyDriver {
> /// type IdInfo = ();
> -/// type Data = Self;
> +/// type Data<'bound> = Self;
> /// const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
> ///
> -/// fn probe(
> -/// _pdev: &pci::Device<Core>,
> -/// _id_info: &Self::IdInfo,
> -/// ) -> impl PinInit<Self, Error> {
> +/// fn probe<'bound>(
> +/// _pdev: &'bound pci::Device<Core>,
> +/// _id_info: &'bound Self::IdInfo,
> +/// ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound {
> /// Err(ENODEV)
> /// }
> /// }
> @@ -302,7 +302,7 @@ pub trait Driver: Send {
> 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>;
> @@ -311,8 +311,10 @@ pub trait Driver: Send {
> ///
> /// Called when a new pci device is added or discovered. Implementers
> should
> /// attempt to initialize the device here.
> - 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;
>
> /// PCI driver unbind.
> ///
> @@ -324,7 +326,7 @@ 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_dma.rs b/samples/rust/rust_dma.rs
> index e583c6b8390a..943655a85ec6 100644
> --- a/samples/rust/rust_dma.rs
> +++ b/samples/rust/rust_dma.rs
> @@ -58,10 +58,13 @@ unsafe impl kernel::transmute::FromBytes for MyStruct {}
>
> impl pci::Driver for DmaSampleDriver {
> type IdInfo = ();
> - type Data = Self;
> + type Data<'bound> = Self;
> const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
>
> - fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl
> PinInit<Self, Error> {
> + fn probe<'bound>(
> + pdev: &'bound pci::Device<Core>,
> + _info: &'bound Self::IdInfo,
> + ) -> impl PinInit<Self, Error> + 'bound {
> pin_init::pin_init_scope(move || {
> dev_info!(pdev, "Probe DMA test driver.\n");
>
> diff --git a/samples/rust/rust_driver_auxiliary.rs
> b/samples/rust/rust_driver_auxiliary.rs
> index 61d5bf2e8c0d..2f57912fe87f 100644
> --- a/samples/rust/rust_driver_auxiliary.rs
> +++ b/samples/rust/rust_driver_auxiliary.rs
> @@ -66,11 +66,14 @@ struct ParentDriver {
>
> impl pci::Driver for ParentDriver {
> type IdInfo = ();
> - type Data = Self;
> + type Data<'bound> = Self;
>
> const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
>
> - fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl
> PinInit<Self, Error> {
> + fn probe<'bound>(
> + pdev: &'bound pci::Device<Core>,
> + _info: &'bound Self::IdInfo,
> + ) -> impl PinInit<Self, Error> + 'bound {
> Ok(Self {
> _reg0: auxiliary::Registration::new(
> pdev.as_ref(),
> diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs
> index f43c6a660b39..30b9311812f3 100644
> --- a/samples/rust/rust_driver_pci.rs
> +++ b/samples/rust/rust_driver_pci.rs
> @@ -140,11 +140,14 @@ fn config_space(pdev: &pci::Device<Bound>) {
>
> impl pci::Driver for SampleDriver {
> type IdInfo = TestIndex;
> - type Data = Self;
> + type Data<'bound> = Self;
>
> const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
>
> - fn probe(pdev: &pci::Device<Core>, info: &Self::IdInfo) -> impl
> PinInit<Self, Error> {
> + fn probe<'bound>(
> + pdev: &'bound pci::Device<Core>,
> + info: &'bound Self::IdInfo,
> + ) -> impl PinInit<Self, Error> + 'bound {
> pin_init::pin_init_scope(move || {
> let vendor = pdev.vendor_id();
> dev_dbg!(
