Commit 284ae0be authored by Lee Jones's avatar Lee Jones Committed by Greg Kroah-Hartman
Browse files

rust: miscdevice: Provide accessor to pull out miscdevice::this_device 



There are situations where a pointer to a `struct device` will become
necessary (e.g. for calling into dev_*() functions).  This accessor
allows callers to pull this out from the `struct miscdevice`.

Signed-off-by: default avatarLee Jones <lee@kernel.org>
Signed-off-by: default avatarAlice Ryhl <aliceryhl@google.com>
Tested-by: default avatarLee Jones <lee@kernel.org>
Reviewed-by: default avatarDanilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241210-miscdevice-file-param-v3-3-b2a79b666dc5@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 88441d5c

rust/kernel/miscdevice.rs

+11 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


use crate::{

    bindings,

    device::Device,

    error::{to_result, Error, Result, VTABLE_DEFAULT_ERROR},

    fs::File,

    prelude::*,
@@ -85,6 +86,16 @@ pub fn register(opts: MiscDeviceOptions) -> impl PinInit<Self, Error> { 
    pub fn as_raw(&self) -> *mut bindings::miscdevice {

        self.inner.get()

    }



    /// Access the `this_device` field.

    pub fn device(&self) -> &Device {

        // SAFETY: This can only be called after a successful register(), which always

        // initialises `this_device` with a valid device. Furthermore, the signature of this

        // function tells the borrow-checker that the `&Device` reference must not outlive the

        // `&MiscDeviceRegistration<T>` used to obtain it, so the last use of the reference must be

        // before the underlying `struct miscdevice` is destroyed.

        unsafe { Device::as_ref((*self.as_raw()).this_device) }

    }

}



#[pinned_drop]