[GIT PULL] Rust `hrtimer` support for v6.15

From: Andreas Hindborg
Date: Thu Mar 13 2025 - 09:16:17 EST


Hi Miguel,

Please pull the Rust support for hrtimer for v6.15.

This initial support allows for intrusive use of timers without
allocating when starting a timer. We support `Pin<Box<T>>`, `Arc<T>`,
`Pin<&T>` and `Pin<&mut T>` pointer types for working with these
intrusive timers. We support at most one `HrTimer` field in a struct for
use with this API.

For now, the primary users will be the Rust null block driver, `rnull`,
and the Rust kernel mode setting driver `rkvms`. I expect us to add more
features to the API as the demands from users grow.

The PR also includes two changes for the core rust and rust/alloc
subsytems that are dependencies of the hrtimer Rust API: `Arc::as_ptr`
and `Box::into_pin`. The alloc change was Ack'd by Danilo.

The commits were in linux-next since next-20250313.

The following changes since commit a64dcfb451e254085a7daee5fe51bf22959d52d3:

Linux 6.14-rc2 (2025-02-09 12:45:03 -0800)

are available in the Git repository at:

https://github.com/rust-for-linux/linux.git tags/rust-hrtimer-for-v6.15

for you to fetch changes up to 15a3c03ca02b6caec995de178904ab8c637d584c:

rust: hrtimer: add maintainer entry (2025-03-11 21:00:43 +0100)


Best regards,
Andreas Hindborg

----------------------------------------------------------------
Rust hrtimer API for v6.15

Introduce Rust support for the `hrtimer` subsystem:

- Add a way to use the `hrtimer` subsystem from Rust. Rust code can now set up
intrusive timers without allocating when starting the timer.

- Add support for `Pin<Box<_>>`, `Arc<_>`, `Pin<&_>` and `Pin<&mut _>` as
pointer types for use with timer callbacks.

- Add support for setting clock source and timer mode.

`kernel` crate:

- Add `Arc::as_ptr` for converting an `Arc` to a raw pointer. This is a
dependency for the `hrtimer` API.

- Add `Box::into_pin` for converting a `Box<_>` into a `Pin<Box<_>>` to align
with Rust `alloc`. This is a dependency for the `hrtimer` API.

----------------------------------------------------------------
Andreas Hindborg (13):
rust: hrtimer: introduce hrtimer support
rust: sync: add `Arc::as_ptr`
rust: hrtimer: implement `HrTimerPointer` for `Arc`
rust: hrtimer: allow timer restart from timer handler
rust: hrtimer: add `UnsafeHrTimerPointer`
rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`
rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`
rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`
rust: alloc: add `Box::into_pin`
rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>`
rust: hrtimer: add `HrTimerMode`
rust: hrtimer: add clocksource selection through `ClockId`
rust: hrtimer: add maintainer entry

MAINTAINERS | 15 ++
rust/kernel/alloc/kbox.rs | 6 +
rust/kernel/sync/arc.rs | 13 +-
rust/kernel/time.rs | 68 +++++
rust/kernel/time/hrtimer.rs | 517 ++++++++++++++++++++++++++++++++++++
rust/kernel/time/hrtimer/arc.rs | 100 +++++++
rust/kernel/time/hrtimer/pin.rs | 104 ++++++++
rust/kernel/time/hrtimer/pin_mut.rs | 108 ++++++++
rust/kernel/time/hrtimer/tbox.rs | 120 +++++++++
9 files changed, 1049 insertions(+), 2 deletions(-)
create mode 100644 rust/kernel/time/hrtimer.rs
create mode 100644 rust/kernel/time/hrtimer/arc.rs
create mode 100644 rust/kernel/time/hrtimer/pin.rs
create mode 100644 rust/kernel/time/hrtimer/pin_mut.rs
create mode 100644 rust/kernel/time/hrtimer/tbox.rs