On 8/18/25 7:57 AM, Danilo Krummrich wrote:
> On Mon Aug 18, 2025 at 3:33 AM CEST, John Hubbard wrote:
>> + /// Create a `Class` from the raw class code value, or `None` if the value doesn't
>> + /// match any known class.
>> + pub fn from_u32(value: u32) -> Option<Self> {
>> + match value {
>> + $(x if x == Self::$variant.0 => Some(Self::$variant),)+
>> + _ => None,
>> + }
>> + }
>
> Additional to the comments from Alex, I think one should be
> `impl TryFrom<u32> for Class`.
Will do.
>
>> +
>> + /// Create a new `pci::DeviceId` from a class number, mask, and specific vendor.
>> + ///
>> + /// This is more targeted than [`DeviceId::from_class`]: in addition to matching by Vendor, it
>> + /// also matches the PCI Class (up to the entire 24 bits, depending on the mask).
>> + pub const fn from_class_and_vendor(class: Class, class_mask: u32, vendor: u32) -> Self {
>> + Self(bindings::pci_device_id {
>> + vendor,
>> + device: DeviceId::PCI_ANY_ID,
>> + subvendor: DeviceId::PCI_ANY_ID,
>> + subdevice: DeviceId::PCI_ANY_ID,
>> + class: class.as_u32(),
>> + class_mask,
>> + driver_data: 0,
>> + override_only: 0,
>> + })
>> + }
>> }
>>
>> // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `pci_device_id` and does not add
>> @@ -410,6 +600,18 @@ pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {
>> // - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`.
>> Ok(unsafe { bindings::pci_resource_len(self.as_raw(), bar.try_into()?) })
>> }
>> +
>> + /// Returns the full 24-bit PCI class code as stored in hardware.
>> + /// This includes base class, subclass, and programming interface.
>> + pub fn class_code_raw(&self) -> u32 {
>> + // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
>> + unsafe { (*self.as_raw()).class }
>> + }
>> +
>> + /// Returns the PCI class as a `Class` struct, or `None` if the class code is invalid.
>> + pub fn class_enum(&self) -> Option<Class> {
>> + Class::from_u32(self.class_code_raw())
>> + }
>
> I don't think we have struct pci_dev instances without a valid class code,
> can we? Maybe we should convert infallibly here.
Interesting. Let me un-dizzy myself about the lifetimes here, and verify if
that claim is true. :)
thanks,
--
John Hubbard
