From 3f2a5ba784b808109cac0aac921213e43143a216 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Thu, 21 Aug 2025 15:32:44 -0400 Subject: rust: hrtimer: Add HrTimerCallbackContext and ::forward() With Linux's hrtimer API, there's a number of methods that can only be called in two situations: * When we have exclusive access to the hrtimer and it is not currently active * When we're within the context of an hrtimer callback context This commit handles the second situation and implements hrtimer_forward() support in the context of a timer callback. We do this by introducing a HrTimerCallbackContext type which is provided to users during the RawHrTimerCallback::run() callback, and then add a forward() function to the type. Signed-off-by: Lyude Paul Reviewed-by: Daniel Almeida Reviewed-by: Andreas Hindborg Link: https://lore.kernel.org/r/20250821193259.964504-5-lyude@redhat.com Signed-off-by: Andreas Hindborg --- rust/kernel/time/hrtimer/arc.rs | 9 ++++++++- rust/kernel/time/hrtimer/pin.rs | 9 ++++++++- rust/kernel/time/hrtimer/pin_mut.rs | 12 +++++++++--- rust/kernel/time/hrtimer/tbox.rs | 9 ++++++++- 4 files changed, 33 insertions(+), 6 deletions(-) (limited to 'rust/kernel/time/hrtimer') diff --git a/rust/kernel/time/hrtimer/arc.rs b/rust/kernel/time/hrtimer/arc.rs index ed490a7a8950..7be82bcb352a 100644 --- a/rust/kernel/time/hrtimer/arc.rs +++ b/rust/kernel/time/hrtimer/arc.rs @@ -3,6 +3,7 @@ use super::HasHrTimer; use super::HrTimer; use super::HrTimerCallback; +use super::HrTimerCallbackContext; use super::HrTimerHandle; use super::HrTimerMode; use super::HrTimerPointer; @@ -99,6 +100,12 @@ where // allocation from other `Arc` clones. let receiver = unsafe { ArcBorrow::from_raw(data_ptr) }; - T::run(receiver).into_c() + // SAFETY: + // - By C API contract `timer_ptr` is the pointer that we passed when queuing the timer, so + // it is a valid pointer to a `HrTimer` embedded in a `T`. + // - We are within `RawHrTimerCallback::run` + let context = unsafe { HrTimerCallbackContext::from_raw(timer_ptr) }; + + T::run(receiver, context).into_c() } } diff --git a/rust/kernel/time/hrtimer/pin.rs b/rust/kernel/time/hrtimer/pin.rs index aef16d9ee2f0..4d39ef781697 100644 --- a/rust/kernel/time/hrtimer/pin.rs +++ b/rust/kernel/time/hrtimer/pin.rs @@ -3,6 +3,7 @@ use super::HasHrTimer; use super::HrTimer; use super::HrTimerCallback; +use super::HrTimerCallbackContext; use super::HrTimerHandle; use super::HrTimerMode; use super::RawHrTimerCallback; @@ -103,6 +104,12 @@ where // here. let receiver_pin = unsafe { Pin::new_unchecked(receiver_ref) }; - T::run(receiver_pin).into_c() + // SAFETY: + // - By C API contract `timer_ptr` is the pointer that we passed when queuing the timer, so + // it is a valid pointer to a `HrTimer` embedded in a `T`. + // - We are within `RawHrTimerCallback::run` + let context = unsafe { HrTimerCallbackContext::from_raw(timer_ptr) }; + + T::run(receiver_pin, context).into_c() } } diff --git a/rust/kernel/time/hrtimer/pin_mut.rs b/rust/kernel/time/hrtimer/pin_mut.rs index 767d0a4e8a2c..9d9447d4d57e 100644 --- a/rust/kernel/time/hrtimer/pin_mut.rs +++ b/rust/kernel/time/hrtimer/pin_mut.rs @@ -1,8 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 use super::{ - HasHrTimer, HrTimer, HrTimerCallback, HrTimerHandle, HrTimerMode, RawHrTimerCallback, - UnsafeHrTimerPointer, + HasHrTimer, HrTimer, HrTimerCallback, HrTimerCallbackContext, HrTimerHandle, HrTimerMode, + RawHrTimerCallback, UnsafeHrTimerPointer, }; use core::{marker::PhantomData, pin::Pin, ptr::NonNull}; @@ -107,6 +107,12 @@ where // here. let receiver_pin = unsafe { Pin::new_unchecked(receiver_ref) }; - T::run(receiver_pin).into_c() + // SAFETY: + // - By C API contract `timer_ptr` is the pointer that we passed when queuing the timer, so + // it is a valid pointer to a `HrTimer` embedded in a `T`. + // - We are within `RawHrTimerCallback::run` + let context = unsafe { HrTimerCallbackContext::from_raw(timer_ptr) }; + + T::run(receiver_pin, context).into_c() } } diff --git a/rust/kernel/time/hrtimer/tbox.rs b/rust/kernel/time/hrtimer/tbox.rs index ec08303315f2..aa1ee31a7195 100644 --- a/rust/kernel/time/hrtimer/tbox.rs +++ b/rust/kernel/time/hrtimer/tbox.rs @@ -3,6 +3,7 @@ use super::HasHrTimer; use super::HrTimer; use super::HrTimerCallback; +use super::HrTimerCallbackContext; use super::HrTimerHandle; use super::HrTimerMode; use super::HrTimerPointer; @@ -119,6 +120,12 @@ where // `data_ptr` exist. let data_mut_ref = unsafe { Pin::new_unchecked(&mut *data_ptr) }; - T::run(data_mut_ref).into_c() + // SAFETY: + // - By C API contract `timer_ptr` is the pointer that we passed when queuing the timer, so + // it is a valid pointer to a `HrTimer` embedded in a `T`. + // - We are within `RawHrTimerCallback::run` + let context = unsafe { HrTimerCallbackContext::from_raw(timer_ptr) }; + + T::run(data_mut_ref, context).into_c() } } -- cgit v1.2.3