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[PATCH v6 05/14] rust: hrtimer: allow timer restart from timer handler

Andreas Hindborg posted 14 patches 11 months, 1 week ago
There is a newer version of this series
[PATCH v6 05/14] rust: hrtimer: allow timer restart from timer handler
Posted by Andreas Hindborg 11 months, 1 week ago 
This patch allows timer handlers to report that they want a timer to be
restarted after the timer handler has finished executing.

Also update the `hrtimer` documentation to showcase the new feature.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 rust/kernel/time/hrtimer.rs     | 37 ++++++++++++++++++++++++++++++++++++-
 rust/kernel/time/hrtimer/arc.rs |  4 +---
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
index d0842c7c4c6ddffeef9a79cbf9727819060e4333..50e8c23578b5cf7196893ac88d9547fc027f1f04 100644
--- a/rust/kernel/time/hrtimer.rs
+++ b/rust/kernel/time/hrtimer.rs
@@ -167,7 +167,7 @@ pub trait HrTimerCallback {
     type CallbackTargetParameter<'a>;
 
     /// Called by the timer logic when the timer fires.
-    fn run(this: Self::CallbackTargetParameter<'_>)
+    fn run(this: Self::CallbackTargetParameter<'_>) -> HrTimerRestart
     where
         Self: Sized;
 }
@@ -262,6 +262,41 @@ unsafe fn start(self_ptr: *const Self, expires: Ktime) {
     }
 }
 
+/// Restart policy for timers.
+pub enum HrTimerRestart {
+    /// Timer should not be restarted.
+    NoRestart,
+    /// Timer should be restarted.
+    Restart,
+}
+
+impl From<u32> for HrTimerRestart {
+    fn from(value: u32) -> Self {
+        match value {
+            0 => Self::NoRestart,
+            _ => Self::Restart,
+        }
+    }
+}
+
+impl From<i32> for HrTimerRestart {
+    fn from(value: i32) -> Self {
+        match value {
+            0 => Self::NoRestart,
+            _ => Self::Restart,
+        }
+    }
+}
+
+impl From<HrTimerRestart> for bindings::hrtimer_restart {
+    fn from(value: HrTimerRestart) -> Self {
+        match value {
+            HrTimerRestart::NoRestart => bindings::hrtimer_restart_HRTIMER_NORESTART,
+            HrTimerRestart::Restart => bindings::hrtimer_restart_HRTIMER_RESTART,
+        }
+    }
+}
+
 /// Use to implement the [`HasHrTimer<T>`] trait.
 ///
 /// See [`module`] documentation for an example.
diff --git a/rust/kernel/time/hrtimer/arc.rs b/rust/kernel/time/hrtimer/arc.rs
index 4c1812f190bc7a9e0b2fcd5ea2e320f45ba584bc..cee143b04aa21fa6c60c3363cd95f7a67360cbf8 100644
--- a/rust/kernel/time/hrtimer/arc.rs
+++ b/rust/kernel/time/hrtimer/arc.rs
@@ -82,8 +82,6 @@ impl<U> RawHrTimerCallback for Arc<U>
         // timer. This `U` is contained in an `Arc`.
         let receiver = unsafe { ArcBorrow::from_raw(data_ptr) };
 
-        U::run(receiver);
-
-        bindings::hrtimer_restart_HRTIMER_NORESTART
+        U::run(receiver).into()
     }
 }

-- 
2.47.0
Re: [PATCH v6 05/14] rust: hrtimer: allow timer restart from timer handler
Posted by Tamir Duberstein 11 months, 1 week ago 
On Fri, Jan 10, 2025 at 3:17 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>
> This patch allows timer handlers to report that they want a timer to be
> restarted after the timer handler has finished executing.
>
> Also update the `hrtimer` documentation to showcase the new feature.
>
> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
> ---
>  rust/kernel/time/hrtimer.rs     | 37 ++++++++++++++++++++++++++++++++++++-
>  rust/kernel/time/hrtimer/arc.rs |  4 +---
>  2 files changed, 37 insertions(+), 4 deletions(-)
>
> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
> index d0842c7c4c6ddffeef9a79cbf9727819060e4333..50e8c23578b5cf7196893ac88d9547fc027f1f04 100644
> --- a/rust/kernel/time/hrtimer.rs
> +++ b/rust/kernel/time/hrtimer.rs
> @@ -167,7 +167,7 @@ pub trait HrTimerCallback {
>      type CallbackTargetParameter<'a>;
>
>      /// Called by the timer logic when the timer fires.
> -    fn run(this: Self::CallbackTargetParameter<'_>)
> +    fn run(this: Self::CallbackTargetParameter<'_>) -> HrTimerRestart
>      where
>          Self: Sized;
>  }
> @@ -262,6 +262,41 @@ unsafe fn start(self_ptr: *const Self, expires: Ktime) {
>      }
>  }
>
> +/// Restart policy for timers.
> +pub enum HrTimerRestart {
> +    /// Timer should not be restarted.
> +    NoRestart,
> +    /// Timer should be restarted.
> +    Restart,
> +}
> +
> +impl From<u32> for HrTimerRestart {
> +    fn from(value: u32) -> Self {
> +        match value {
> +            0 => Self::NoRestart,
> +            _ => Self::Restart,
> +        }
> +    }
> +}
> +
> +impl From<i32> for HrTimerRestart {
> +    fn from(value: i32) -> Self {
> +        match value {
> +            0 => Self::NoRestart,
> +            _ => Self::Restart,
> +        }
> +    }
> +}

These are for converting from bindings to our enum, right? Why do we
need both signed and unsigned, and why do we hardcode 0 rather than
using the generated constants?

> +
> +impl From<HrTimerRestart> for bindings::hrtimer_restart {
> +    fn from(value: HrTimerRestart) -> Self {
> +        match value {
> +            HrTimerRestart::NoRestart => bindings::hrtimer_restart_HRTIMER_NORESTART,
> +            HrTimerRestart::Restart => bindings::hrtimer_restart_HRTIMER_RESTART,
> +        }
> +    }
> +}
> +
>  /// Use to implement the [`HasHrTimer<T>`] trait.
>  ///
>  /// See [`module`] documentation for an example.
> diff --git a/rust/kernel/time/hrtimer/arc.rs b/rust/kernel/time/hrtimer/arc.rs
> index 4c1812f190bc7a9e0b2fcd5ea2e320f45ba584bc..cee143b04aa21fa6c60c3363cd95f7a67360cbf8 100644
> --- a/rust/kernel/time/hrtimer/arc.rs
> +++ b/rust/kernel/time/hrtimer/arc.rs
> @@ -82,8 +82,6 @@ impl<U> RawHrTimerCallback for Arc<U>
>          // timer. This `U` is contained in an `Arc`.
>          let receiver = unsafe { ArcBorrow::from_raw(data_ptr) };
>
> -        U::run(receiver);
> -
> -        bindings::hrtimer_restart_HRTIMER_NORESTART
> +        U::run(receiver).into()
>      }
>  }
>
> --
> 2.47.0
>
>
>
Re: [PATCH v6 05/14] rust: hrtimer: allow timer restart from timer handler
Posted by Andreas Hindborg 11 months, 1 week ago 
"Tamir Duberstein" <tamird@gmail.com> writes:

> On Fri, Jan 10, 2025 at 3:17 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>>
>> This patch allows timer handlers to report that they want a timer to be
>> restarted after the timer handler has finished executing.
>>
>> Also update the `hrtimer` documentation to showcase the new feature.
>>
>> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
>> ---
>>  rust/kernel/time/hrtimer.rs     | 37 ++++++++++++++++++++++++++++++++++++-
>>  rust/kernel/time/hrtimer/arc.rs |  4 +---
>>  2 files changed, 37 insertions(+), 4 deletions(-)
>>
>> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
>> index d0842c7c4c6ddffeef9a79cbf9727819060e4333..50e8c23578b5cf7196893ac88d9547fc027f1f04 100644
>> --- a/rust/kernel/time/hrtimer.rs
>> +++ b/rust/kernel/time/hrtimer.rs
>> @@ -167,7 +167,7 @@ pub trait HrTimerCallback {
>>      type CallbackTargetParameter<'a>;
>>
>>      /// Called by the timer logic when the timer fires.
>> -    fn run(this: Self::CallbackTargetParameter<'_>)
>> +    fn run(this: Self::CallbackTargetParameter<'_>) -> HrTimerRestart
>>      where
>>          Self: Sized;
>>  }
>> @@ -262,6 +262,41 @@ unsafe fn start(self_ptr: *const Self, expires: Ktime) {
>>      }
>>  }
>>
>> +/// Restart policy for timers.
>> +pub enum HrTimerRestart {
>> +    /// Timer should not be restarted.
>> +    NoRestart,
>> +    /// Timer should be restarted.
>> +    Restart,
>> +}
>> +
>> +impl From<u32> for HrTimerRestart {
>> +    fn from(value: u32) -> Self {
>> +        match value {
>> +            0 => Self::NoRestart,
>> +            _ => Self::Restart,
>> +        }
>> +    }
>> +}
>> +
>> +impl From<i32> for HrTimerRestart {
>> +    fn from(value: i32) -> Self {
>> +        match value {
>> +            0 => Self::NoRestart,
>> +            _ => Self::Restart,
>> +        }
>> +    }
>> +}
>
> These are for converting from bindings to our enum, right? Why do we
> need both signed and unsigned,

Depending on kernel (target arch) configuration, the enum type will be
either signed or unsigned on C side.

I guess I could try to figure out what kernel configs effect the change
and then do conditional compilation on Rust side, but it seems overkill.

> and why do we hardcode 0 rather than
> using the generated constants?

We should use the constants - thanks.


Best regards,
Andreas Hindborg
Re: [PATCH v6 05/14] rust: hrtimer: allow timer restart from timer handler
Posted by Tamir Duberstein 11 months, 1 week ago 
On Wed, Jan 15, 2025 at 6:21 AM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>
> "Tamir Duberstein" <tamird@gmail.com> writes:
>
> > On Fri, Jan 10, 2025 at 3:17 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
> >>
> >> This patch allows timer handlers to report that they want a timer to be
> >> restarted after the timer handler has finished executing.
> >>
> >> Also update the `hrtimer` documentation to showcase the new feature.
> >>
> >> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
> >> ---
> >>  rust/kernel/time/hrtimer.rs     | 37 ++++++++++++++++++++++++++++++++++++-
> >>  rust/kernel/time/hrtimer/arc.rs |  4 +---
> >>  2 files changed, 37 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
> >> index d0842c7c4c6ddffeef9a79cbf9727819060e4333..50e8c23578b5cf7196893ac88d9547fc027f1f04 100644
> >> --- a/rust/kernel/time/hrtimer.rs
> >> +++ b/rust/kernel/time/hrtimer.rs
> >> @@ -167,7 +167,7 @@ pub trait HrTimerCallback {
> >>      type CallbackTargetParameter<'a>;
> >>
> >>      /// Called by the timer logic when the timer fires.
> >> -    fn run(this: Self::CallbackTargetParameter<'_>)
> >> +    fn run(this: Self::CallbackTargetParameter<'_>) -> HrTimerRestart
> >>      where
> >>          Self: Sized;
> >>  }
> >> @@ -262,6 +262,41 @@ unsafe fn start(self_ptr: *const Self, expires: Ktime) {
> >>      }
> >>  }
> >>
> >> +/// Restart policy for timers.
> >> +pub enum HrTimerRestart {
> >> +    /// Timer should not be restarted.
> >> +    NoRestart,
> >> +    /// Timer should be restarted.
> >> +    Restart,
> >> +}
> >> +
> >> +impl From<u32> for HrTimerRestart {
> >> +    fn from(value: u32) -> Self {
> >> +        match value {
> >> +            0 => Self::NoRestart,
> >> +            _ => Self::Restart,
> >> +        }
> >> +    }
> >> +}
> >> +
> >> +impl From<i32> for HrTimerRestart {
> >> +    fn from(value: i32) -> Self {
> >> +        match value {
> >> +            0 => Self::NoRestart,
> >> +            _ => Self::Restart,
> >> +        }
> >> +    }
> >> +}
> >
> > These are for converting from bindings to our enum, right? Why do we
> > need both signed and unsigned,
>
> Depending on kernel (target arch) configuration, the enum type will be
> either signed or unsigned on C side.
>
> I guess I could try to figure out what kernel configs effect the change
> and then do conditional compilation on Rust side, but it seems overkill.

The bindings seem to contain a type alias:

pub const hrtimer_restart_HRTIMER_NORESTART: hrtimer_restart = 0;
pub const hrtimer_restart_HRTIMER_RESTART: hrtimer_restart = 1;
pub type hrtimer_restart = ffi::c_uint;

Perhaps you could impl `From<bindings:: hrtimer_restart>` instead?

Tamir
Re: [PATCH v6 05/14] rust: hrtimer: allow timer restart from timer handler
Posted by Andreas Hindborg 11 months, 1 week ago 
"Tamir Duberstein" <tamird@gmail.com> writes:

> On Wed, Jan 15, 2025 at 6:21 AM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>>
>> "Tamir Duberstein" <tamird@gmail.com> writes:
>>
>> > On Fri, Jan 10, 2025 at 3:17 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
>> >>
>> >> This patch allows timer handlers to report that they want a timer to be
>> >> restarted after the timer handler has finished executing.
>> >>
>> >> Also update the `hrtimer` documentation to showcase the new feature.
>> >>
>> >> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
>> >> ---
>> >>  rust/kernel/time/hrtimer.rs     | 37 ++++++++++++++++++++++++++++++++++++-
>> >>  rust/kernel/time/hrtimer/arc.rs |  4 +---
>> >>  2 files changed, 37 insertions(+), 4 deletions(-)
>> >>
>> >> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
>> >> index d0842c7c4c6ddffeef9a79cbf9727819060e4333..50e8c23578b5cf7196893ac88d9547fc027f1f04 100644
>> >> --- a/rust/kernel/time/hrtimer.rs
>> >> +++ b/rust/kernel/time/hrtimer.rs
>> >> @@ -167,7 +167,7 @@ pub trait HrTimerCallback {
>> >>      type CallbackTargetParameter<'a>;
>> >>
>> >>      /// Called by the timer logic when the timer fires.
>> >> -    fn run(this: Self::CallbackTargetParameter<'_>)
>> >> +    fn run(this: Self::CallbackTargetParameter<'_>) -> HrTimerRestart
>> >>      where
>> >>          Self: Sized;
>> >>  }
>> >> @@ -262,6 +262,41 @@ unsafe fn start(self_ptr: *const Self, expires: Ktime) {
>> >>      }
>> >>  }
>> >>
>> >> +/// Restart policy for timers.
>> >> +pub enum HrTimerRestart {
>> >> +    /// Timer should not be restarted.
>> >> +    NoRestart,
>> >> +    /// Timer should be restarted.
>> >> +    Restart,
>> >> +}
>> >> +
>> >> +impl From<u32> for HrTimerRestart {
>> >> +    fn from(value: u32) -> Self {
>> >> +        match value {
>> >> +            0 => Self::NoRestart,
>> >> +            _ => Self::Restart,
>> >> +        }
>> >> +    }
>> >> +}
>> >> +
>> >> +impl From<i32> for HrTimerRestart {
>> >> +    fn from(value: i32) -> Self {
>> >> +        match value {
>> >> +            0 => Self::NoRestart,
>> >> +            _ => Self::Restart,
>> >> +        }
>> >> +    }
>> >> +}
>> >
>> > These are for converting from bindings to our enum, right? Why do we
>> > need both signed and unsigned,
>>
>> Depending on kernel (target arch) configuration, the enum type will be
>> either signed or unsigned on C side.
>>
>> I guess I could try to figure out what kernel configs effect the change
>> and then do conditional compilation on Rust side, but it seems overkill.
>
> The bindings seem to contain a type alias:
>
> pub const hrtimer_restart_HRTIMER_NORESTART: hrtimer_restart = 0;
> pub const hrtimer_restart_HRTIMER_RESTART: hrtimer_restart = 1;
> pub type hrtimer_restart = ffi::c_uint;
>
> Perhaps you could impl `From<bindings:: hrtimer_restart>` instead?

Yes - good idea!


Best regards,
Andreas Hindborg

Patchew 2.1-devel-b67e4c2

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