On Fri Aug 22, 2025 at 11:03 AM JST, John Hubbard wrote:
> This allows callers to write Vendor::SOME_COMPANY instead of
> bindings::PCI_VENDOR_ID_SOME_COMPANY.
>
> New APIs:
> Vendor::SOME_COMPANY
> Vendor::as_raw()
> Vendor: From<u32> for Vendor
>
> Cc: Danilo Krummrich <dakr@xxxxxxxxxx>
> Cc: Alexandre Courbot <acourbot@xxxxxxxxxx>
> Cc: Elle Rhumsaa <elle@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> ---
> rust/kernel/pci.rs | 2 +-
> rust/kernel/pci/id.rs | 355 +++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 355 insertions(+), 2 deletions(-)
>
> diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
> index 0faec49bf8a2..d4675b7d4a86 100644
> --- a/rust/kernel/pci.rs
> +++ b/rust/kernel/pci.rs
> @@ -25,7 +25,7 @@
>
> mod id;
>
> -pub use self::id::{Class, ClassMask};
> +pub use self::id::{Class, ClassMask, Vendor};
>
> /// An adapter for the registration of PCI drivers.
> pub struct Adapter<T: Driver>(T);
> diff --git a/rust/kernel/pci/id.rs b/rust/kernel/pci/id.rs
> index 1291553b4e15..dd91e25a6890 100644
> --- a/rust/kernel/pci/id.rs
> +++ b/rust/kernel/pci/id.rs
> @@ -2,7 +2,7 @@
>
> //! PCI device identifiers and related types.
> //!
> -//! This module contains PCI class codes and supporting types.
> +//! This module contains PCI class codes, Vendor IDs, and supporting types.
>
> use crate::{bindings, error::code::EINVAL, error::Error, prelude::*};
> use core::fmt;
> @@ -115,6 +115,74 @@ fn try_from(value: u32) -> Result<Self, Self::Error> {
> }
> }
>
> +/// PCI vendor IDs.
> +///
> +/// Each entry contains the 16-bit PCI vendor ID as assigned by the PCI SIG.
> +///
> +/// # Examples
> +///
> +/// ```
> +/// # use kernel::{device::Core, pci::{self, Vendor}, prelude::*};
> +/// fn log_device_info(pdev: &pci::Device<Core>) -> Result<()> {
> +/// // Get the raw PCI vendor ID and convert to Vendor
> +/// let vendor_id = pdev.vendor_id();
> +/// let vendor = Vendor::new(vendor_id.into());
> +/// dev_info!(
> +/// pdev.as_ref(),
> +/// "Device: Vendor={}, Device=0x{:x}\n",
> +/// vendor,
> +/// pdev.device_id()
> +/// );
> +/// Ok(())
> +/// }
> +/// ```
> +#[derive(Debug, Clone, Copy, PartialEq, Eq)]
> +#[repr(transparent)]
> +pub struct Vendor(u32);
> +
> +macro_rules! define_all_pci_vendors {
> + (
> + $($variant:ident = $binding:expr,)+
> + ) => {
> +
> + impl Vendor {
> + $(
> + #[allow(missing_docs)]
> + pub const $variant: Self = Self($binding as u32);
> + )+
> + }
> +
> + /// Convert a raw 16-bit vendor ID to a `Vendor`.
> + impl From<u32> for Vendor {
> + fn from(value: u32) -> Self {
> + match value {
> + $(x if x == Self::$variant.0 => Self::$variant,)+
> + _ => Self::UNKNOWN,
> + }
> + }
Naive question from someone with a device tree background and almost no
PCI experience: one consequence of using `From` here is that if I create
an non-registered Vendor value (e.g. `let vendor =
Vendor::from(0xf0f0)`), then do `vendor.as_raw()`, I won't get the value
passed initially but the one for `UNKNOWN`, e.g. `0xffff`. Are we ok
with this?
> + }
> + };
> +}
> +
> +/// Once constructed, a `Vendor` contains a valid PCI Vendor ID.
> +impl Vendor {
> + /// Create a new Vendor from a raw 16-bit vendor ID.
The argument is 32-bit. :) Which triggers the question: why store these
as u32 if a u16 is the right size?
