On 8/25/25 3:47 PM, Elle Rhumsaa wrote:
> On Wed, Aug 20, 2025 at 09:42:05PM -0700, 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,
>> + }
>> + }
>> + }
>> + };
>> +}
>> +
>> +/// Once constructed, a `Vendor` contains a valid PCI Vendor ID.
>> +impl Vendor {
>> + /// Create a new Vendor from a raw 16-bit vendor ID.
>> + pub fn new(vendor_id: u32) -> Self {
>> + Self::from(vendor_id)
>> + }
>
> Reversing this implementation would allow for a signature:
>
> ```rust
> pub const fn new(vendor_id: u32) -> Self {
> ...
> }
> ```
>
> Which would allow use in `const` contexts. Until we get a stable
> `const-trait` impl, this is kind of the best workaround.
>
> Then, the `From<u32>` implementation can call `Self::new`.
>
> Not really applicable here, but you can also provide a `Default`
> implementation for `Self::new` with no parameters.
>
I'm going to post a new version, v7, later today, that will
change this area around quite a bit.
thanks,
--
John Hubbard
