[PATCH v8 0/4] rust: use Delta instead of raw jiffies for timeouts and delays

[FUJITA Tomonori <tomo@flapping.org>]

From: FUJITA Tomonori <fujita.tomonori@gmail.com>

CondVar::wait_interruptible_timeout() and Queue::enqueue_delayed() use
a raw jiffies count (a plain c_ulong alias with no type safety).
Callers have to know on their own that the value means jiffies and
convert to/from it themselves, which is easy to get wrong (e.g.
passing a millisecond value where a jiffies value is expected).

Both APIs just take a span of time, so they can use Delta<Jiffy>
instead. The condvar patch also updates binder's ioctl_freeze(), the
only caller of wait_interruptible_timeout().

This series is based on timekeeping-next, because the binder change
uses Delta::to_jiffies_timeout(). The workqueue patch conflicts with
Danilo's workqueue series [1], which also changes the signature of
enqueue_delayed(). The conflict is trivial.

Binder and workqueue maintainers, could you take a look at the changes
to your code? Andreas and Boqun, which tree should this series go
through?

[1] https://lore.kernel.org/rust-for-linux/20260807165252.3849875-1-dakr@kernel.org/

---
v8:
- Add a patch to make Delta::ZERO generic over the time unit (Markus, Gary)
- Add a patch to add Delta::as_jiffies_unsigned() (Gary)
- workqueue: use as_jiffies_unsigned()
- condvar: use Delta::ZERO in binder (Gary)
v7: https://lore.kernel.org/rust-for-linux/20260930014124.1454138-1-tomo@flapping.org/
- Drop patches 1-3, merged in v7.3-rc1
- Drop patch 4, reworked and applied to timekeeping-next
- Drop patch 7, rust/kernel/serdev.rs now uses the Jiffies alias
- Rebase on timekeeping-next
- workqueue: keep the parameter name `delay`
- workqueue: document that a negative delay is treated as zero
- condvar: document that a negative timeout is treated as zero
- Reword the commit messages of both patches. The condvar one now
  describes how the binder freeze timeout changes for 2^31 ms or more
v6: https://lore.kernel.org/rust-for-linux/20260808062839.1159990-1-tomo@flapping.org/
- Make Nsec/Jiffy zero-variant enums so they can't be constructed
- Rename `Delta::to_jiffies()` to `to_jiffies_timeout()` to reflect its timeout semantics
v5: https://lore.kernel.org/rust-for-linux/20260806073241.1024319-1-tomo@flapping.org/
- Fix as_millis_ceil() rounding near i64::MAX
- Import Delta instead of using kernel::time::Delta twice
v4: https://lore.kernel.org/rust-for-linux/20260722214951.72941-1-tomo@flapping.org/
- Make Delta generic over its time unit with Nsec and Jiffy types
v3: https://lore.kernel.org/rust-for-linux/20260717042247.3634961-1-tomo@flapping.org/
- Add new Jiffies type and convert the APIs to take impl Into<Jiffies>
v2: https://lore.kernel.org/rust-for-linux/20260712235246.3069713-1-tomo@flapping.org/
- Fix potential overflow in from_jiffies()
- Fix inflating bug in as_jiffies_ceil()
- Add a patch to convert enqueue_delayed()
- Add a patch to remove Jiffies/Msecs aliases
v1: https://lore.kernel.org/rust-for-linux/20260704132558.2253275-1-tomo@aliasing.net/

FUJITA Tomonori (4):
  rust: time: make Delta::ZERO generic over the time unit
  rust: time: add Delta::as_jiffies_unsigned()
  rust: workqueue: take a Delta<Jiffy> for the enqueue delay
  rust: sync: condvar: use Delta<Jiffy> for timeout and result

 drivers/android/binder/process.rs |  7 ++++---
 rust/kernel/sync/condvar.rs       | 31 ++++++++++++++++++++--------
 rust/kernel/time.rs               | 34 ++++++++++++++++++++++++++++---
 rust/kernel/workqueue.rs          | 13 ++++++++----
 4 files changed, 66 insertions(+), 19 deletions(-)


base-commit: 2ea0119f72dba597aa8a98cbdb72c564bfc5cb38
-- 
2.43.0