rust: driver: introduce a DriverLayout trait

The DriverLayout trait describes the layout of a specific driver
structure, such as `struct pci_driver` or `struct platform_driver`.

In a first step, this replaces the associated type RegType of the
RegistrationOps with the DriverLayout::DriverType associated type.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-4-dakr@kernel.org
[ Rename driver::Driver to driver::DriverLayout, as it represents the
  layout of a driver structure rather than the driver structure itself.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
This commit is contained in:
Danilo Krummrich
2026-01-07 11:35:02 +01:00
parent 5f4476e983
commit 0af1a9e462
6 changed files with 80 additions and 50 deletions

View File

@@ -23,13 +23,17 @@ use core::{
/// An adapter for the registration of auxiliary drivers.
pub struct Adapter<T: Driver>(T);
// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
// SAFETY:
// - `bindings::auxiliary_driver` is a C type declared as `repr(C)`.
unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
type DriverType = bindings::auxiliary_driver;
}
// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if
// a preceding call to `register` has been successful.
unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
type RegType = bindings::auxiliary_driver;
unsafe fn register(
adrv: &Opaque<Self::RegType>,
adrv: &Opaque<Self::DriverType>,
name: &'static CStr,
module: &'static ThisModule,
) -> Result {
@@ -41,14 +45,14 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
(*adrv.get()).id_table = T::ID_TABLE.as_ptr();
}
// SAFETY: `adrv` is guaranteed to be a valid `RegType`.
// SAFETY: `adrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe {
bindings::__auxiliary_driver_register(adrv.get(), module.0, name.as_char_ptr())
})
}
unsafe fn unregister(adrv: &Opaque<Self::RegType>) {
// SAFETY: `adrv` is guaranteed to be a valid `RegType`.
unsafe fn unregister(adrv: &Opaque<Self::DriverType>) {
// SAFETY: `adrv` is guaranteed to be a valid `DriverType`.
unsafe { bindings::auxiliary_driver_unregister(adrv.get()) }
}
}

View File

@@ -99,23 +99,33 @@ use crate::{acpi, device, of, str::CStr, try_pin_init, types::Opaque, ThisModule
use core::pin::Pin;
use pin_init::{pin_data, pinned_drop, PinInit};
/// Trait describing the layout of a specific device driver.
///
/// This trait describes the layout of a specific driver structure, such as `struct pci_driver` or
/// `struct platform_driver`.
///
/// # Safety
///
/// Implementors must guarantee that:
/// - `DriverType` is `repr(C)`.
pub unsafe trait DriverLayout {
/// The specific driver type embedding a `struct device_driver`.
type DriverType: Default;
}
/// The [`RegistrationOps`] trait serves as generic interface for subsystems (e.g., PCI, Platform,
/// Amba, etc.) to provide the corresponding subsystem specific implementation to register /
/// unregister a driver of the particular type (`RegType`).
/// unregister a driver of the particular type (`DriverType`).
///
/// For instance, the PCI subsystem would set `RegType` to `bindings::pci_driver` and call
/// For instance, the PCI subsystem would set `DriverType` to `bindings::pci_driver` and call
/// `bindings::__pci_register_driver` from `RegistrationOps::register` and
/// `bindings::pci_unregister_driver` from `RegistrationOps::unregister`.
///
/// # Safety
///
/// A call to [`RegistrationOps::unregister`] for a given instance of `RegType` is only valid if a
/// preceding call to [`RegistrationOps::register`] has been successful.
pub unsafe trait RegistrationOps {
/// The type that holds information about the registration. This is typically a struct defined
/// by the C portion of the kernel.
type RegType: Default;
/// A call to [`RegistrationOps::unregister`] for a given instance of `DriverType` is only valid if
/// a preceding call to [`RegistrationOps::register`] has been successful.
pub unsafe trait RegistrationOps: DriverLayout {
/// Registers a driver.
///
/// # Safety
@@ -123,7 +133,7 @@ pub unsafe trait RegistrationOps {
/// On success, `reg` must remain pinned and valid until the matching call to
/// [`RegistrationOps::unregister`].
unsafe fn register(
reg: &Opaque<Self::RegType>,
reg: &Opaque<Self::DriverType>,
name: &'static CStr,
module: &'static ThisModule,
) -> Result;
@@ -134,7 +144,7 @@ pub unsafe trait RegistrationOps {
///
/// Must only be called after a preceding successful call to [`RegistrationOps::register`] for
/// the same `reg`.
unsafe fn unregister(reg: &Opaque<Self::RegType>);
unsafe fn unregister(reg: &Opaque<Self::DriverType>);
}
/// A [`Registration`] is a generic type that represents the registration of some driver type (e.g.
@@ -146,7 +156,7 @@ pub unsafe trait RegistrationOps {
#[pin_data(PinnedDrop)]
pub struct Registration<T: RegistrationOps> {
#[pin]
reg: Opaque<T::RegType>,
reg: Opaque<T::DriverType>,
}
// SAFETY: `Registration` has no fields or methods accessible via `&Registration`, so it is safe to
@@ -161,13 +171,13 @@ impl<T: RegistrationOps> Registration<T> {
/// Creates a new instance of the registration object.
pub fn new(name: &'static CStr, module: &'static ThisModule) -> impl PinInit<Self, Error> {
try_pin_init!(Self {
reg <- Opaque::try_ffi_init(|ptr: *mut T::RegType| {
reg <- Opaque::try_ffi_init(|ptr: *mut T::DriverType| {
// SAFETY: `try_ffi_init` guarantees that `ptr` is valid for write.
unsafe { ptr.write(T::RegType::default()) };
unsafe { ptr.write(T::DriverType::default()) };
// SAFETY: `try_ffi_init` guarantees that `ptr` is valid for write, and it has
// just been initialised above, so it's also valid for read.
let drv = unsafe { &*(ptr as *const Opaque<T::RegType>) };
let drv = unsafe { &*(ptr as *const Opaque<T::DriverType>) };
// SAFETY: `drv` is guaranteed to be pinned until `T::unregister`.
unsafe { T::register(drv, name, module) }

View File

@@ -92,13 +92,17 @@ macro_rules! i2c_device_table {
/// An adapter for the registration of I2C drivers.
pub struct Adapter<T: Driver>(T);
// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
// SAFETY:
// - `bindings::i2c_driver` is a C type declared as `repr(C)`.
unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
type DriverType = bindings::i2c_driver;
}
// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if
// a preceding call to `register` has been successful.
unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
type RegType = bindings::i2c_driver;
unsafe fn register(
idrv: &Opaque<Self::RegType>,
idrv: &Opaque<Self::DriverType>,
name: &'static CStr,
module: &'static ThisModule,
) -> Result {
@@ -133,12 +137,12 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
(*idrv.get()).driver.acpi_match_table = acpi_table;
}
// SAFETY: `idrv` is guaranteed to be a valid `RegType`.
// SAFETY: `idrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe { bindings::i2c_register_driver(module.0, idrv.get()) })
}
unsafe fn unregister(idrv: &Opaque<Self::RegType>) {
// SAFETY: `idrv` is guaranteed to be a valid `RegType`.
unsafe fn unregister(idrv: &Opaque<Self::DriverType>) {
// SAFETY: `idrv` is guaranteed to be a valid `DriverType`.
unsafe { bindings::i2c_del_driver(idrv.get()) }
}
}

View File

@@ -50,13 +50,17 @@ pub use self::irq::{
/// An adapter for the registration of PCI drivers.
pub struct Adapter<T: Driver>(T);
// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
// SAFETY:
// - `bindings::pci_driver` is a C type declared as `repr(C)`.
unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
type DriverType = bindings::pci_driver;
}
// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if
// a preceding call to `register` has been successful.
unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
type RegType = bindings::pci_driver;
unsafe fn register(
pdrv: &Opaque<Self::RegType>,
pdrv: &Opaque<Self::DriverType>,
name: &'static CStr,
module: &'static ThisModule,
) -> Result {
@@ -68,14 +72,14 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
(*pdrv.get()).id_table = T::ID_TABLE.as_ptr();
}
// SAFETY: `pdrv` is guaranteed to be a valid `RegType`.
// SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe {
bindings::__pci_register_driver(pdrv.get(), module.0, name.as_char_ptr())
})
}
unsafe fn unregister(pdrv: &Opaque<Self::RegType>) {
// SAFETY: `pdrv` is guaranteed to be a valid `RegType`.
unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) {
// SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
unsafe { bindings::pci_unregister_driver(pdrv.get()) }
}
}

View File

@@ -26,13 +26,17 @@ use core::{
/// An adapter for the registration of platform drivers.
pub struct Adapter<T: Driver>(T);
// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
// SAFETY:
// - `bindings::platform_driver` is a C type declared as `repr(C)`.
unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
type DriverType = bindings::platform_driver;
}
// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if
// a preceding call to `register` has been successful.
unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
type RegType = bindings::platform_driver;
unsafe fn register(
pdrv: &Opaque<Self::RegType>,
pdrv: &Opaque<Self::DriverType>,
name: &'static CStr,
module: &'static ThisModule,
) -> Result {
@@ -55,12 +59,12 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
(*pdrv.get()).driver.acpi_match_table = acpi_table;
}
// SAFETY: `pdrv` is guaranteed to be a valid `RegType`.
// SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe { bindings::__platform_driver_register(pdrv.get(), module.0) })
}
unsafe fn unregister(pdrv: &Opaque<Self::RegType>) {
// SAFETY: `pdrv` is guaranteed to be a valid `RegType`.
unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) {
// SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.
unsafe { bindings::platform_driver_unregister(pdrv.get()) };
}
}

View File

@@ -27,13 +27,17 @@ use core::{
/// An adapter for the registration of USB drivers.
pub struct Adapter<T: Driver>(T);
// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
// SAFETY:
// - `bindings::usb_driver` is a C type declared as `repr(C)`.
unsafe impl<T: Driver + 'static> driver::DriverLayout for Adapter<T> {
type DriverType = bindings::usb_driver;
}
// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if
// a preceding call to `register` has been successful.
unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
type RegType = bindings::usb_driver;
unsafe fn register(
udrv: &Opaque<Self::RegType>,
udrv: &Opaque<Self::DriverType>,
name: &'static CStr,
module: &'static ThisModule,
) -> Result {
@@ -45,14 +49,14 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
(*udrv.get()).id_table = T::ID_TABLE.as_ptr();
}
// SAFETY: `udrv` is guaranteed to be a valid `RegType`.
// SAFETY: `udrv` is guaranteed to be a valid `DriverType`.
to_result(unsafe {
bindings::usb_register_driver(udrv.get(), module.0, name.as_char_ptr())
})
}
unsafe fn unregister(udrv: &Opaque<Self::RegType>) {
// SAFETY: `udrv` is guaranteed to be a valid `RegType`.
unsafe fn unregister(udrv: &Opaque<Self::DriverType>) {
// SAFETY: `udrv` is guaranteed to be a valid `DriverType`.
unsafe { bindings::usb_deregister(udrv.get()) };
}
}