[PATCH v3 1/5] rust: miscdevice: Provide accessor to pull out miscdevice::this_device

Lee Jones
2024-12-06T09:05:37Z

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: Lee Jones <lee@kernel.org>
---
rust/kernel/miscdevice.rs | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index 7e2a79b3ae26..55340f316006 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -10,11 +10,13 @@

use crate::{
bindings,
+ device::Device,
error::{to_result, Error, Result, VTABLE_DEFAULT_ERROR},
prelude::*,
str::CStr,
types::{ForeignOwnable, Opaque},
};
+
use core::{
ffi::{c_int, c_long, c_uint, c_ulong},
marker::PhantomData,
@@ -84,6 +86,13 @@ pub fn register(opts: MiscDeviceOptions) -> impl PinInit<Self, Error> {
pub fn as_raw(&self) -> *mut bindings::miscdevice {
self.inner.get()
}
+
+ /// Returns a pointer to the current Device
+ pub fn device(&self) -> &Device {
+ // SAFETY: This is only accessible after a successful register() which always
+ // initialises this_device with a valid device.
+ unsafe { Device::as_ref((*self.as_raw()).this_device) }
+ }
}

#[pinned_drop]
--
2.47.0.338.g60cca15819-goog