rust: pci: make Driver trait lifetime-parameterized

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.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-13-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 14 insertions, 14 deletions

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 314ad9fefdb0..5071cae6543f 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -64,7 +64,7 @@ pub struct Adapter<T: Driver>(T);
 // - `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);
 }
 
@@ -129,8 +129,8 @@ impl<T: Driver> Adapter<T> {
 
         // 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>() };
+        // and stored a `Pin<KBox<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 {
     type IdInfo: 'static;
 
     /// The type of the driver's bus device private data.
-    type Data: Send;
+    type Data<'bound>: Send + 'bound;
 
     /// The table of device ids supported by the driver.
     const ID_TABLE: IdTable<Self::IdInfo>;
@@ -311,10 +311,10 @@ pub trait Driver {
     ///
     /// 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.
     ///
@@ -326,7 +326,7 @@ pub trait Driver {
     /// 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<&Self::Data<'bound>>) {
         let _ = (dev, this);
     }
 }