Re: [PATCH v5 1/8] rust: pci: add device name method

["Danilo Krummrich" <dakr@kernel.org>]

On Fri Jan 16, 2026 at 10:49 PM CET, Timur Tabi wrote:
> Add a name() method to the `Device` type, which returns a CStr that
> contains the device name, typically the BDF address for PCI devices.
>
> Signed-off-by: Timur Tabi <ttabi@nvidia.com>
> ---
>  rust/helpers/device.c |  5 +++++
>  rust/kernel/device.rs | 16 ++++++++++++++++
>  2 files changed, 21 insertions(+)
>
> diff --git a/rust/helpers/device.c b/rust/helpers/device.c
> index 9a4316bafedf..4609b62f6a06 100644
> --- a/rust/helpers/device.c
> +++ b/rust/helpers/device.c
> @@ -25,3 +25,8 @@ void rust_helper_dev_set_drvdata(struct device *dev, void *data)
>  {
>  	dev_set_drvdata(dev, data);
>  }
> +
> +const char *rust_helper_dev_name(const struct device *dev)

Please add the __rust_helper annotation.

> +{
> +	return dev_name(dev);
> +}
> diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
> index c79be2e2bfe3..636c522a8374 100644
> --- a/rust/kernel/device.rs
> +++ b/rust/kernel/device.rs
> @@ -483,6 +483,22 @@ pub fn fwnode(&self) -> Option<&property::FwNode> {
>          // defined as a `#[repr(transparent)]` wrapper around `fwnode_handle`.
>          Some(unsafe { &*fwnode_handle.cast() })
>      }
> +
> +    /// Returns the name of the device.
> +    ///
> +    /// This is the kobject name of the device, or its initial name if the kobject is not yet
> +    /// available.
> +    ///
> +    /// For PCI devices, the name in the format "DDDD:BB:DD.F" where:

This is driver core code, please drop any details for PCI. Also, the subject of
the patch seems wrong.

> +    /// - DDDD is the PCI domain (4 hex digits)
> +    /// - BB is the bus number (2 hex digits)
> +    /// - DD is the device number (2 hex digits)
> +    /// - F is the function number (1 hex digit)
> +    pub fn name(&self) -> &CStr {
> +        // SAFETY: By its type invariant `self.as_raw()` is a valid pointer to a `struct device`.
> +        // The returned string is valid for the lifetime of the device.
> +        unsafe { CStr::from_char_ptr(bindings::dev_name(self.as_raw())) }
> +    }
>  }
>  
>  // SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic
> -- 
> 2.52.0