On Thu Aug 28, 2025 at 3:25 PM CEST, Alexandre Courbot wrote:
> On Wed Aug 27, 2025 at 8:12 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::from_raw() -- Only accessible from the pci (parent) module.
>> Vendor::as_raw()
>> Vendor: fmt::Display 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 | 349 +++++++++++++++++++++++++++++++++++++++++-
>> 2 files changed, 349 insertions(+), 2 deletions(-)
>>
>> diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
>> index 212c4a6834fb..f15cfd0e76d9 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 55d9cdcc6658..4b0ad8d4edc6 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;
>> @@ -109,6 +109,69 @@ 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<()> {
>> +/// // Compare raw vendor ID with known vendor constant
>> +/// let vendor_id = pdev.vendor_id();
>> +/// if vendor_id == Vendor::NVIDIA.as_raw() {
>> +/// dev_info!(
>> +/// pdev.as_ref(),
>> +/// "Found NVIDIA device: 0x{:x}\n",
>> +/// pdev.device_id()
>> +/// );
>> +/// }
>> +/// Ok(())
>> +/// }
>> +/// ```
>> +#[derive(Debug, Clone, Copy, PartialEq, Eq)]
>> +#[repr(transparent)]
>> +pub struct Vendor(u16);
>> +
>> +macro_rules! define_all_pci_vendors {
>> + (
>> + $($variant:ident = $binding:expr,)+
>> + ) => {
>> +
>> + impl Vendor {
>
> Why the blank line here? (same for the `define_all_pci_classes` in the
> previous patch).
>
>> + $(
>> + #[allow(missing_docs)]
>> + pub const $variant: Self = Self($binding as u16);
>> + )+
>> + }
>> + };
>> +}
>> +
>> +/// Once constructed, a `Vendor` contains a valid PCI Vendor ID.
>> +impl Vendor {
>> + /// Create a Vendor from a raw 16-bit vendor ID.
>> + /// Only accessible from the parent pci module.
>> + #[expect(dead_code)]
>> + #[inline]
>> + pub(super) fn from_raw(vendor_id: u16) -> Self {
>> + Self(vendor_id)
>> + }
>> +
>> + /// Get the raw 16-bit vendor ID value.
>> + #[inline]
>> + pub const fn as_raw(self) -> u16 {
>> + self.0
>> + }
>> +}
>> +
>> +impl fmt::Display for Vendor {
>> + #[inline]
>> + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
>> + write!(f, "0x{:04x}", self.0)
>> + }
>> +}
>
> Possibly an exercice for a future patch, but do we want to display the
> vendor name if it is defined, rather than its hex code (which is more
> the job of `Debug`)? We could leverage the macro above to do that. The
> same should be doable for the PCI classes.
>
> I suspect strings for all the names already exist on the C side, in
> which case we would want to reuse them instead of defining new ones.
>
> Note that I don't think this needs to be done for this series - it's
> just a thought as I was looking at this `Display` implementation that
> looks more like a `Debug` one.
Yeah, this can be addressed subsequently; it might make sense to align Display
and Debug though. Currently, Vendor simply derives Debug, resulting in the
decimal value to be printed.
