[PATCH v6 0/6] rust: add support for request_irq

Daniel Almeida
2025-07-03T19:31:00Z

---
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 | 102 ++++++++
rust/kernel/irq/request.rs | 508 ++++++++++++++++++++++++++++++++++++++++
rust/kernel/lib.rs | 1 +
rust/kernel/pci.rs | 45 +++-
rust/kernel/platform.rs | 143 ++++++++++-
10 files changed, 837 insertions(+), 3 deletions(-)
---
base-commit: 40b37285e5ecf9bbf7ab29ed5a6e9640e7684e5d
change-id: 20250514-topics-tyr-request_irq-4f6a30837ea8

Best regards,
--
Daniel Almeida <daniel.almeida@collabora.com>