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authorAlice Ryhl <aliceryhl@google.com>2024-01-08 17:49:58 +0300
committerMiguel Ojeda <ojeda@kernel.org>2024-01-28 21:50:48 +0300
commit82e170874849c4c57dba6b4ee1a08fae1c0a5f02 (patch)
tree6bd780287f09cf3f344192f55d6b43d2653e39e4 /rust
parent3e6454177f3a76265cba4901d5caa4eb0c7b6447 (diff)
downloadlinux-82e170874849c4c57dba6b4ee1a08fae1c0a5f02.tar.xz
rust: time: add msecs to jiffies conversion
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>
Diffstat (limited to 'rust')
-rw-r--r--rust/bindings/bindings_helper.h1
-rw-r--r--rust/kernel/lib.rs1
-rw-r--r--rust/kernel/time.rs20
3 files changed, 22 insertions, 0 deletions
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index c0cb4b05b918..936651110c39 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -9,6 +9,7 @@
#include <kunit/test.h>
#include <linux/errname.h>
#include <linux/ethtool.h>
+#include <linux/jiffies.h>
#include <linux/mdio.h>
#include <linux/phy.h>
#include <linux/slab.h>
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index cb2d024db51f..b89ecf4e97a0 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -48,6 +48,7 @@ pub mod std_vendor;
pub mod str;
pub mod sync;
pub mod task;
+pub mod time;
pub mod types;
pub mod workqueue;
diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs
new file mode 100644
index 000000000000..25a896eed468
--- /dev/null
+++ b/rust/kernel/time.rs
@@ -0,0 +1,20 @@
+// 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.
+
+/// 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) }
+}