Commit c1d4519e authored Jan 07, 2026 by Danilo Krummrich

rust: driver: add DEVICE_DRIVER_OFFSET to the DriverLayout trait



Add an associated const DEVICE_DRIVER_OFFSET to the DriverLayout trait
indicating the offset of the embedded struct device_driver within
Self::DriverType, i.e. the specific driver structs, such as struct
pci_driver or struct platform_driver.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-5-dakr@kernel.org


Signed-off-by: Danilo Krummrich <dakr@kernel.org>

parent 0af1a9e4

rust/kernel/auxiliary.rs

+3 −0

Original line number	Diff line number	Diff line
		@@ -25,8 +25,11 @@

		// SAFETY:
		// - `bindings::auxiliary_driver` is a C type declared as `repr(C)`.
		// - `struct auxiliary_driver` embeds a `struct device_driver`.
		// - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.
		unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
		type DriverType = bindings::auxiliary_driver;
		const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);
		}

		// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if

rust/kernel/driver.rs

+7 −1

Original line number	Diff line number	Diff line
		@@ -107,10 +107,16 @@
		/// # Safety
		///
		/// Implementors must guarantee that:
		/// - `DriverType` is `repr(C)`.
		/// - `DriverType` is `repr(C)`,
		/// - `DriverType` embeds a valid `struct device_driver` at byte offset `DEVICE_DRIVER_OFFSET`.
		pub unsafe trait DriverLayout {
		/// The specific driver type embedding a `struct device_driver`.
		type DriverType: Default;

		/// Byte offset of the embedded `struct device_driver` within `DriverType`.
		///
		/// This must correspond exactly to the location of the embedded `struct device_driver` field.
		const DEVICE_DRIVER_OFFSET: usize;
		}

		/// The [`RegistrationOps`] trait serves as generic interface for subsystems (e.g., PCI, Platform,

rust/kernel/i2c.rs

+3 −0

Original line number	Diff line number	Diff line
		@@ -94,8 +94,11 @@ macro_rules! i2c_device_table {

		// SAFETY:
		// - `bindings::i2c_driver` is a C type declared as `repr(C)`.
		// - `struct i2c_driver` embeds a `struct device_driver`.
		// - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.
		unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
		type DriverType = bindings::i2c_driver;
		const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);
		}

		// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if

rust/kernel/pci.rs

+3 −0

Original line number	Diff line number	Diff line
		@@ -52,8 +52,11 @@

		// SAFETY:
		// - `bindings::pci_driver` is a C type declared as `repr(C)`.
		// - `struct pci_driver` embeds a `struct device_driver`.
		// - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.
		unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
		type DriverType = bindings::pci_driver;
		const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);
		}

		// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if

rust/kernel/platform.rs

+3 −0

Original line number	Diff line number	Diff line
		@@ -28,8 +28,11 @@

		// SAFETY:
		// - `bindings::platform_driver` is a C type declared as `repr(C)`.
		// - `struct platform_driver` embeds a `struct device_driver`.
		// - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.
		unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
		type DriverType = bindings::platform_driver;
		const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);
		}

		// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if