mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 13:41:51 +00:00
ddd9120983
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
84 lines
2.2 KiB
Rust
84 lines
2.2 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
//! Time related primitives.
|
|
//!
|
|
//! This module contains the kernel APIs related to time and timers that
|
|
//! have been ported or wrapped for usage by Rust code in the kernel.
|
|
//!
|
|
//! C header: [`include/linux/jiffies.h`](srctree/include/linux/jiffies.h).
|
|
//! C header: [`include/linux/ktime.h`](srctree/include/linux/ktime.h).
|
|
|
|
/// The number of nanoseconds per millisecond.
|
|
pub const NSEC_PER_MSEC: i64 = bindings::NSEC_PER_MSEC as i64;
|
|
|
|
/// The time unit of Linux kernel. One jiffy equals (1/HZ) second.
|
|
pub type Jiffies = core::ffi::c_ulong;
|
|
|
|
/// The millisecond time unit.
|
|
pub type Msecs = core::ffi::c_uint;
|
|
|
|
/// Converts milliseconds to jiffies.
|
|
#[inline]
|
|
pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
|
|
// SAFETY: The `__msecs_to_jiffies` function is always safe to call no
|
|
// matter what the argument is.
|
|
unsafe { bindings::__msecs_to_jiffies(msecs) }
|
|
}
|
|
|
|
/// A Rust wrapper around a `ktime_t`.
|
|
#[repr(transparent)]
|
|
#[derive(Copy, Clone)]
|
|
pub struct Ktime {
|
|
inner: bindings::ktime_t,
|
|
}
|
|
|
|
impl Ktime {
|
|
/// Create a `Ktime` from a raw `ktime_t`.
|
|
#[inline]
|
|
pub fn from_raw(inner: bindings::ktime_t) -> Self {
|
|
Self { inner }
|
|
}
|
|
|
|
/// Get the current time using `CLOCK_MONOTONIC`.
|
|
#[inline]
|
|
pub fn ktime_get() -> Self {
|
|
// SAFETY: It is always safe to call `ktime_get` outside of NMI context.
|
|
Self::from_raw(unsafe { bindings::ktime_get() })
|
|
}
|
|
|
|
/// Divide the number of nanoseconds by a compile-time constant.
|
|
#[inline]
|
|
fn divns_constant<const DIV: i64>(self) -> i64 {
|
|
self.to_ns() / DIV
|
|
}
|
|
|
|
/// Returns the number of nanoseconds.
|
|
#[inline]
|
|
pub fn to_ns(self) -> i64 {
|
|
self.inner
|
|
}
|
|
|
|
/// Returns the number of milliseconds.
|
|
#[inline]
|
|
pub fn to_ms(self) -> i64 {
|
|
self.divns_constant::<NSEC_PER_MSEC>()
|
|
}
|
|
}
|
|
|
|
/// Returns the number of milliseconds between two ktimes.
|
|
#[inline]
|
|
pub fn ktime_ms_delta(later: Ktime, earlier: Ktime) -> i64 {
|
|
(later - earlier).to_ms()
|
|
}
|
|
|
|
impl core::ops::Sub for Ktime {
|
|
type Output = Ktime;
|
|
|
|
#[inline]
|
|
fn sub(self, other: Ktime) -> Ktime {
|
|
Self {
|
|
inner: self.inner - other.inner,
|
|
}
|
|
}
|
|
}
|