Add a wrapper for fsleep(), flexible sleep functions in
include/linux/delay.h which typically deals with hardware delays.
The kernel supports several sleep functions to handle various lengths
of delay. This adds fsleep(), automatically chooses the best sleep
method based on a duration.
fsleep() can only be used in a nonatomic context. This requirement is
not checked by these abstractions, but it is intended that klint [1]
or a similar tool will be used to check it in the future.
Link: https://rust-for-linux.com/klint [1]
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250617144155.3903431-3-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Introduce the `HrTimerExpires` trait to represent types that can be
used as expiration values for high-resolution timers. Define a
required method, `into_nanos()`, which returns the expiration time as a
raw nanosecond value suitable for use with C's hrtimer APIs.
Also extend the `HrTimerMode` to use the `HrTimerExpires` trait.
This refactoring is a preparation for enabling hrtimer code to work
uniformly with both absolute and relative expiration modes.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250610132823.3457263-4-fujita.tomonori@gmail.com
[ changed conversion method names to `as_*` - Andreas ]
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Introduce the ktime_get() associated function to the ClockSource
trait, allowing each clock source to specify how it retrieves the
current time. This enables Instant::now() to be implemented
generically using the type-level ClockSource abstraction.
This change enhances the type safety and extensibility of timekeeping
by statically associating time retrieval mechanisms with their
respective clock types. It also reduces the reliance on hardcoded
clock logic within Instant.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250610093258.3435874-4-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Refactor the Instant type to be generic over a ClockSource type
parameter, enabling static enforcement of clock correctness across
APIs that deal with time. Previously, the clock source was implicitly
fixed (typically CLOCK_MONOTONIC), and developers had to ensure
compatibility manually.
This design eliminates runtime mismatches between clock sources, and
enables stronger type-level guarantees throughout the timer subsystem.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250610093258.3435874-3-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Replace the ClockId enum with a trait-based abstraction called
ClockSource. This change enables expressing clock sources as types and
leveraging the Rust type system to enforce clock correctness at
compile time.
This also sets the stage for future generic abstractions over Instant
types such as Instant<C>.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250610093258.3435874-2-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Avoid 64-bit integer division that 32-bit architectures don't
implement generally. This uses ktime_to_us() and ktime_to_ms()
instead.
The time abstraction needs i64 / u32 division so C's div_s64() can be
used but ktime_to_us() and ktime_to_ms() provide a simpler solution
for this time abstraction problem on 32-bit architectures.
32-bit ARM is the only 32-bit architecture currently supported by
Rust. Using the cfg attribute, only 32-bit architectures will call
ktime_to_us() and ktime_to_ms(), while the other 64-bit architectures
will continue to use the current code as-is to avoid the overhead.
One downside of calling the C's functions is that the as_micros/millis
methods can no longer be const fn. We stick with the simpler approach
unless there's a compelling need for a const fn.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250502004524.230553-1-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Introduce a type representing a specific point in time. We could use
the Ktime type but C's ktime_t is used for both timestamp and
timedelta. To avoid confusion, introduce a new Instant type for
timestamp.
Rename Ktime to Instant and modify their methods for timestamp.
Implement the subtraction operator for Instant:
Delta = Instant A - Instant B
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250423192857.199712-5-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Introduce a type representing a span of time. Define our own type
because `core::time::Duration` is large and could panic during
creation.
time::Ktime could be also used for time duration but timestamp and
timedelta are different so better to use a new type.
i64 is used instead of u64 to represent a span of time; some C drivers
uses negative Deltas and i64 is more compatible with Ktime using i64
too (e.g., ktime_[us|ms]_delta() APIs return i64 so we create Delta
object without type conversion.
i64 is used instead of bindings::ktime_t because when the ktime_t
type is used as timestamp, it represents values from 0 to
KTIME_MAX, which is different from Delta.
as_millis() method isn't used in this patchset. It's planned to be
used in Binder driver.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250423192857.199712-4-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Add PartialEq/Eq/PartialOrd/Ord trait to Ktime so two Ktime instances
can be compared to determine whether a timeout is met or not.
Use the derive implements; we directly touch C's ktime_t rather than
using the C's accessors because it is more efficient and we already do
in the existing code (Ktime::sub).
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250423192857.199712-3-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Allow selecting a clock source for timers by passing a `ClockId`
variant to `HrTimer::new`.
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-12-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Add support for intrusive use of the hrtimer system. For now,
only add support for embedding one timer per Rust struct.
The hrtimer Rust API is based on the intrusive style pattern introduced by
the Rust workqueue API.
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-1-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Currently FFI integer types are defined in libcore. This commit creates
the `ffi` crate and asks bindgen to use that crate for FFI integer types
instead of `core::ffi`.
This commit is preparatory and no type changes are made in this commit
yet.
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240913213041.395655-4-gary@garyguo.net
[ Added `rustdoc`, `rusttest` and KUnit tests support. Rebased on top of
`rust-next` (e.g. migrated more `core::ffi` cases). Reworded crate
docs slightly and formatted. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The definitions related to jiffies are at linux/jiffies.h, and the
definitions related to ktime_t are at linux/ktime.h, since
`kernel::time` provides the functionality dealing with jiffies and
ktime_t, it makes sense to add links to them from Rust's time module.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240411230801.1504496-2-boqun.feng@gmail.com
Introduce a wrapper around `ktime_t` with a few different useful methods.
Rust Binder will use these bindings to compute how many milliseconds a
transaction has been active for when dumping the current state of the
Binder driver. This replicates the logic in C Binder [1].
For a usage example in Rust Binder, see [2].
ktime_get() cannot be safely called in NMI context. This requirement is not
checked by these abstractions, but it is intended that klint [3] or a
similar tool will be used to check it in the future.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240322-rust-ktime_ms_delta-v2-1-d98de1f7c282@google.com
Link: https://lore.kernel.org/lkml/5ac8c0d09392290be789423f0dd78a520b830fab.1682333709.git.zhangchuang3@xiaomi.com/ [1]
Link: https://r.android.com/3004103 [2]
Link: https://rust-for-linux.com/klint [3]
Defines type aliases and conversions for msecs and jiffies.
This is used by Rust Binder for process freezing. There, we want to
sleep until the freeze operation completes, but we want to be able to
abort the process freezing if it doesn't complete within some timeout.
The freeze timeout is supplied in msecs.
Note that we need to convert to jiffies in Binder. It is not enough to
introduce a variant of `CondVar::wait_timeout` that takes the timeout in
msecs because we need to be able to restart the sleep with the remaining
sleep duration if it is interrupted, and if the API takes msecs rather
than jiffies, then that would require a conversion roundtrip jiffies->
msecs->jiffies that is best avoided.
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Tiago Lam <tiagolam@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-2-88e0c871cc05@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
