Re: [PATCH v4 08/20] rust: pci: io: make `ConfigSpace` a view

["Gary Guo" <gary@garyguo.net>]

On Tue Jun 16, 2026 at 7:34 AM BST, Alexandre Courbot wrote:
> On Fri Jun 12, 2026 at 1:28 AM JST, Gary Guo wrote:
>> -/// The PCI configuration space of a device.
>> +/// A view of PCI configuration space of a device.
>>  ///
>>  /// Provides typed read and write accessors for configuration registers
>>  /// using the standard `pci_read_config_*` and `pci_write_config_*` helpers.
>>  ///
>> -/// The generic parameter `S` indicates the maximum size of the configuration space.
>> -/// Use [`Normal`] for 256-byte legacy configuration space or [`Extended`] for
>> -/// 4096-byte PCIe extended configuration space (default).
>> -pub struct ConfigSpace<'a, S: ?Sized + ConfigSpaceKind = Extended> {
>> +/// The generic parameter `T` is the type of the view. The full configuration space is also a
>> +/// special type of view; in such cases, `T` can be [`Normal`] for 256-byte legacy configuration
>> +/// space or [`Extended`] for 4096-byte PCIe extended configuration space (default).
>> +///
>> +/// # Invariants
>> +///
>> +/// `ptr` is aligned and range `ptr..ptr + KnownSize::size(ptr)` is within
>> +/// `0..pdev.cfg_size().into_raw()`.
>> +pub struct ConfigSpace<'a, T: ?Sized = Extended> {
>>      pub(crate) pdev: &'a Device<device::Bound>,
>> -    _marker: PhantomData<S>,
>> +    ptr: *mut T,
>
> `ptr` is used as a pseudo-pointer here, can its documentation be more
> explicit about that?

The invariant section is already hinting this by saying the pointer is between 0
to cfg_size?

Best,
Gary