Implement bus_type_raw(), which returns a raw pointer to the device'
struct bus_type.
This is useful for bus devices, to implement the following trait.
impl TryFrom<&Device> for &pci::Device
With this a caller can try to get the bus specific device from a generic
device in a safe way. try_from() will only succeed if the generic
device' bus type pointer matches the pointer of the bus' type.
Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
Reviewed-by: Benno Lossin <benno.lossin@xxxxxxxxx>
Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
---
rust/kernel/device.rs | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 21b343a1dc4d..67a2fc46cf4c 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -65,6 +65,16 @@ pub(crate) fn as_raw(&self) -> *mut bindings::device {
self.0.get()
}
+ /// Returns a raw pointer to the device' bus type.
+ #[expect(unused)]
+ pub(crate) fn bus_type_raw(&self) -> *const bindings::bus_type {
+ // SAFETY:
+ // - By the type invariants, `self.as_raw()` is a valid pointer to a `struct device`.
+ // - `dev->bus` is a pointer to a `const struct bus_type`, which is only ever set at device
+ // creation.
+ unsafe { (*self.as_raw()).bus }
+ }
+
/// Convert a raw C `struct device` pointer to a `&'a Device`.
///
/// # Safety
--
2.48.1
