Commit d32e4c24 authored by Danilo Krummrich's avatar Danilo Krummrich
Browse files

rust: device: implement device context for Device 



Analogous to bus specific device, implement the DeviceContext generic
for generic devices.

This is used for APIs that work with generic devices (such as Devres) to
evaluate the device's context.

Reviewed-by: default avatarBenno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250413173758.12068-4-dakr@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent fbb92b6a

rust/kernel/device.rs

+9 −2
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 
    str::CStr,

    types::{ARef, Opaque},

};

use core::{fmt, ptr};

use core::{fmt, marker::PhantomData, ptr};



#[cfg(CONFIG_PRINTK)]

use crate::c_str;
@@ -42,7 +42,7 @@ 
/// `bindings::device::release` is valid to be called from any thread, hence `ARef<Device>` can be

/// dropped from any thread.

#[repr(transparent)]

pub struct Device(Opaque<bindings::device>);

pub struct Device<Ctx: DeviceContext = Normal>(Opaque<bindings::device>, PhantomData<Ctx>);



impl Device {

    /// Creates a new reference-counted abstraction instance of an existing `struct device` pointer.
@@ -59,7 +59,9 @@ pub unsafe fn get_device(ptr: *mut bindings::device) -> ARef<Self> { 
        // SAFETY: By the safety requirements ptr is valid

        unsafe { Self::as_ref(ptr) }.into()

    }

}



impl<Ctx: DeviceContext> Device<Ctx> {

    /// Obtain the raw `struct device *`.

    pub(crate) fn as_raw(&self) -> *mut bindings::device {

        self.0.get()
@@ -189,6 +191,11 @@ pub fn property_present(&self, name: &CStr) -> bool { 
    }

}



// SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic

// argument.

kernel::impl_device_context_deref!(unsafe { Device });

kernel::impl_device_context_into_aref!(Device);



// SAFETY: Instances of `Device` are always reference-counted.

unsafe impl crate::types::AlwaysRefCounted for Device {

    fn inc_ref(&self) {