Re: [PATCH v7 0/6] rust: add support for request_irq

[Joel Fernandes <joelagnelf@nvidia.com>]

On Tue, Jul 15, 2025 at 12:16:37PM -0300, Daniel Almeida wrote:
> Changes in v7:

Hello, Daniel,

I tested this series on an Nvidia 3090 GPU running the Nova project and I am
able to register and receive interrupts (there are several WIP patches for
Nova that are needed but your series is a dependency). We are looking forward
to having these patches upstream, please feel free to add my tag to the
patches:

Tested-by: Joel Fernandes <joelagnelf@nvidia.com>

thanks,

 - Joel


> - Rebased on top of driver-core-next
> - Added Flags::new(), which is a const fn. This lets us use build_assert!()
>   to verify the casts (hopefully this is what you meant, Alice?)
> - Changed the Flags inner type to take c_ulong directly, to minimize casts
>   (Thanks, Alice)
> - Moved the flag constants into Impl Flags, instead of using a separate
>   module (Alice)
> - Reverted to using #[repr(u32)] in Threaded/IrqReturn (Thanks Alice,
>   Benno)
> - Fixed all instances where the full path was specified for types in the
>   prelude (Alice)
> - Removed 'static from the CStr used to perform the lookup in the platform
>   accessor (Alice)
> - Renamed the PCI accessors, as asked by Danilo
> - Added more docs to Flags, going into more detail on what they do and how
>   to use them (Miguel)
> - Fixed the indentation in some of the docs (Alice)
> - Added Alice's r-b as appropriate
> - Link to v6: https://lore.kernel.org/rust-for-linux/20250703-topics-tyr-request_irq-v6-0-74103bdc7c52@collabora.com/
> 
> Changes in v6:
> - Fixed some typos in the docs (thanks, Dirk!)
> - Reordered the arguments for the accessors in platform.rs (Danilo)
> - Renamed handle_on_thread() to handle_threaded() (Danilo)
> - Changed the documentation for Handler and ThreadedHandler to what
>   Danilo suggested
> - Link to v5: https://lore.kernel.org/r/20250627-topics-tyr-request_irq-v5-0-0545ee4dadf6@collabora.com
> 
> Changes in v5:
> 
> Thanks, Danilo {
>   - Removed extra scope in the examples.
>   - Renamed Registration::register() to Registration::new(),
>   - Switched to try_pin_init! in Registration::new() (thanks for the
>     code and the help, Boqun and Benno)
>   - Renamed the trait functions to handle() and handle_on_thread().
>   - Introduced IrqRequest with an unsafe pub(crate) constructor
>   - Made both register() and the accessors that return IrqRequest public
>     the idea is to allow both of these to work:
> 	// `irq` is an `irq::Registration`
> 	let irq = pdev.threaded_irq_by_name()?
>   and
> 	// `req` is an `IrqRequest`.
> 	let req = pdev.irq_by_name()?;
> 	// `irq` is an `irq::Registration`
> 	let irq = irq::ThreadedRegistration::new(req)?;
> 
>   - Added another name in the byname variants. There's now one for the
>     request part and the other one to register()
>   - Reworked the examples in request.rs
>   - Implemented the irq accessors in place for pci.rs
>   - Split the platform accessor macros into two
> }
> 
> - Added a rust helper for pci_irq_vectors if !CONFIG_PCI_MSI (thanks,
> Intel 0day bot)
> - Link to v4: https://lore.kernel.org/r/20250608-topics-tyr-request_irq-v4-0-81cb81fb8073@collabora.com
> 
> Changes in v4:
> 
> Thanks, Benno {
>   - Split series into more patches (see patches 1-4)
>   - Use cast() where possible
>   - Merge pub use statements.
>   - Add {Threaded}IrqReturn::into_inner() instead of #[repr(u32)]
>   - Used AtomicU32 instead of SpinLock to add interior mutability to the
>     handler's data. SpinLockIrq did not land yet.
>   - Mention that `&self` is !Unpin and was initialized using pin_init in
>     drop()
>   - Fix the docs slightly
> }
> 
> - Add {try_}synchronize_irq().
> - Use Devres for the irq registration (see RegistrationInner). This idea
>   was suggested by Danilo and Alice.
> - Added PCI accessors (as asked by Joel Fernandez)
> - Fix a major oversight: we were passing in a pointer to Registration
>   in register_{threaded}_irq() but casting it to Handler/ThreadedHandler in
>   the callbacks.
> - Make register() pub(crate) so drivers can only retrieve registrations
>   through device-specific accessors. This forbids drivers from trying to
>   register an invalid irq.
> - I think this will still go through a few rounds, so I'll defer the
>   patch to update MAINTAINERS for now.
> 
> - Link to v3: https://lore.kernel.org/r/20250514-topics-tyr-request_irq-v3-0-d6fcc2591a88@collabora.com
> 
> Changes in v3:
> - Rebased on driver-core-next
> - Added patch to get the irq numbers from a platform device (thanks,
>   Christian!)
> - Split flags into its own file.
> - Change iff to "if and only if"
> - Implement PartialEq and Eq for Flags
> - Fix some broken docs/markdown
> - Reexport most things so users can elide ::request from the path
> - Add a blanket implementation of ThreadedHandler and Handler for
>   Arc/Box<T: Handler> that just forwards the call to the T. This lets us
>   have Arc<Foo> and Box<Foo> as handlers if Foo: Handler.
> - Rework the examples a bit.
> - Remove "as _" casts in favor of "as u64" for flags. This is needed to
>   cast the individual flags into u64.
> - Use #[repr(u32)] for ThreadedIrqReturn and IrqReturn.
> - Wrapped commit messages to < 75 characters
> 
> - Link to v2: https://lore.kernel.org/r/20250122163932.46697-1-daniel.almeida@collabora.com
> 
> Changes in v2:
> - Added Co-developed-by tag to account for the work that Alice did in order to
> figure out how to do this without Opaque<T> (Thanks!)
> - Removed Opaque<T> in favor of plain T
> - Fixed the examples
> - Made sure that the invariants sections are the last entry in the docs
> - Switched to slot.cast() where applicable,
> - Mentioned in the safety comments that we require that T: Sync,
> - Removed ThreadedFnReturn in favor of IrqReturn,
> - Improved the commit message
> 
> Link to v1: https://lore.kernel.org/rust-for-linux/20241024-topic-panthor-rs-request_irq-v1-1-7cbc51c182ca@collabora.com/
> 
> ---
> Daniel Almeida (6):
>       rust: irq: add irq module
>       rust: irq: add flags module
>       rust: irq: add support for non-threaded IRQs and handlers
>       rust: irq: add support for threaded IRQs and handlers
>       rust: platform: add irq accessors
>       rust: pci: add irq accessors
> 
>  rust/bindings/bindings_helper.h |   1 +
>  rust/helpers/helpers.c          |   1 +
>  rust/helpers/irq.c              |   9 +
>  rust/helpers/pci.c              |   8 +
>  rust/kernel/irq.rs              |  22 ++
>  rust/kernel/irq/flags.rs        | 124 ++++++++++
>  rust/kernel/irq/request.rs      | 490 ++++++++++++++++++++++++++++++++++++++++
>  rust/kernel/lib.rs              |   1 +
>  rust/kernel/pci.rs              |  45 +++-
>  rust/kernel/platform.rs         | 146 +++++++++++-
>  10 files changed, 844 insertions(+), 3 deletions(-)
> ---
> base-commit: 3964d07dd821efe9680e90c51c86661a98e60a0f
> change-id: 20250712-topics-tyr-request_irq2-ae7ee9b85854
> 
> Best regards,
> -- 
> Daniel Almeida <daniel.almeida@collabora.com>
>