Commit c46f6024 authored by Danilo Krummrich's avatar Danilo Krummrich
Browse files

rust: auxiliary: use generic device drvdata accessors 

Take advantage of the generic drvdata accessors of the generic Device
type.

While at it, use from_result() instead of match.

Link: https://lore.kernel.org/r/20250621195118.124245-6-dakr@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 4231712c

rust/helpers/auxiliary.c

+0 −10
Original line number Diff line number Diff line
@@ -2,16 +2,6 @@ 


#include <linux/auxiliary_bus.h>



void rust_helper_auxiliary_set_drvdata(struct auxiliary_device *adev, void *data)

{

	auxiliary_set_drvdata(adev, data);

}



void *rust_helper_auxiliary_get_drvdata(struct auxiliary_device *adev)

{

	return auxiliary_get_drvdata(adev);

}



void rust_helper_auxiliary_device_uninit(struct auxiliary_device *adev)

{

	return auxiliary_device_uninit(adev);

rust/kernel/auxiliary.rs

+15 −20
Original line number Diff line number Diff line
@@ -8,9 +8,9 @@ 
    bindings, container_of, device,

    device_id::RawDeviceId,

    driver,

    error::{to_result, Result},

    error::{from_result, to_result, Result},

    prelude::*,

    types::{ForeignOwnable, Opaque},

    types::Opaque,

    ThisModule,

};

use core::{
@@ -60,37 +60,32 @@ extern "C" fn probe_callback( 
        // `struct auxiliary_device`.

        //

        // INVARIANT: `adev` is valid for the duration of `probe_callback()`.

        let adev = unsafe { &*adev.cast::<Device<device::Core>>() };

        let adev = unsafe { &*adev.cast::<Device<device::CoreInternal>>() };



        // SAFETY: `DeviceId` is a `#[repr(transparent)`] wrapper of `struct auxiliary_device_id`

        // and does not add additional invariants, so it's safe to transmute.

        let id = unsafe { &*id.cast::<DeviceId>() };

        let info = T::ID_TABLE.info(id.index());



        match T::probe(adev, info) {

            Ok(data) => {

                // Let the `struct auxiliary_device` own a reference of the driver's private data.

                // SAFETY: By the type invariant `adev.as_raw` returns a valid pointer to a

                // `struct auxiliary_device`.

                unsafe {

                    bindings::auxiliary_set_drvdata(adev.as_raw(), data.into_foreign().cast())

                };

            }

            Err(err) => return Error::to_errno(err),

        }

        from_result(|| {

            let data = T::probe(adev, info)?;



        0

            adev.as_ref().set_drvdata(data);

            Ok(0)

        })

    }



    extern "C" fn remove_callback(adev: *mut bindings::auxiliary_device) {

        // SAFETY: The auxiliary bus only ever calls the remove callback with a valid pointer to a

        // SAFETY: The auxiliary bus only ever calls the probe callback with a valid pointer to a

        // `struct auxiliary_device`.

        let ptr = unsafe { bindings::auxiliary_get_drvdata(adev) };

        //

        // INVARIANT: `adev` is valid for the duration of `probe_callback()`.

        let adev = unsafe { &*adev.cast::<Device<device::CoreInternal>>() };



        // SAFETY: `remove_callback` is only ever called after a successful call to

        // `probe_callback`, hence it's guaranteed that `ptr` points to a valid and initialized

        // `KBox<T>` pointer created through `KBox::into_foreign`.

        drop(unsafe { KBox::<T>::from_foreign(ptr.cast()) });

        // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called

        // and stored a `Pin<KBox<T>>`.

        drop(unsafe { adev.as_ref().drvdata_obtain::<Pin<KBox<T>>>() });

    }

}