linux-toradex.git/rust/kernel/time/hrtimer.rs, branch v6.16-rc5

rust: time: Fix compile error in impl_has_hr_timer macro

2025-06-10T18:11:36+00:00

Fix a compile error in the `impl_has_hr_timer!` macro as follows:

error[E0599]: no method named cast_mut found for raw pointer *mut Foo in the current scope

The `container_of!` macro already returns a mutable pointer when used
in a `*mut T` context so the `.cast_mut()` method is not available.

[ We missed this one because there is no caller yet and it is
  a macro. - Miguel ]

Fixes: 74d6a606c2b3 ("rust: retain pointer mut-ness in `container_of!`")
Signed-off-by: FUJITA Tomonori 
Reviewed-by: Benno Lossin 
Acked-by: Andreas Hindborg 
Link: https://lore.kernel.org/r/20250606020505.3186533-1-fujita.tomonori@gmail.com
Signed-off-by: Miguel Ojeda

rust: workaround `bindgen` issue with forward references to `enum` types

2025-05-22T13:39:16+00:00

`bindgen` currently generates the wrong type for an `enum` when there
is a forward reference to it. For instance:

    enum E;
    enum E { A };

generates:

    pub const E_A: E = 0;
    pub type E = i32;

instead of the expected:

    pub const E_A: E = 0;
    pub type E = ffi::c_uint;

The issue was reported to upstream `bindgen` [1].

Now, both GCC and Clang support silently these forward references to
`enum` types, unless `-Wpedantic` is passed, and it turns out that some
headers in the kernel depend on them.

Thus, depending on how the headers are included, which in turn may depend
on the kernel configuration or the architecture, we may get a different
type on the Rust side for a given C `enum`.

That can be quite confusing, to say the least, especially since
developers may only notice issues when building for other architectures
like in [2]. In particular, they may end up forcing a cast and adding
an `#[allow(clippy::unnecessary_cast)]` like it was done in commit
94e05a66ea3e ("rust: hrtimer: allow timer restart from timer handler"),
which isn't great.

Instead, let's have a section at the top of our `bindings_helper.h` that
`#include`s the headers with the affected types -- hopefully there are
not many cases and there is a single ordering that covers all cases.

This allows us to remove the cast and the `#[allow]`, thus keeping the
correct code in the source files. When the issue gets resolved in upstream
`bindgen` (and we update our minimum `bindgen` version), we can easily
remove this section at the top.

Link: https://github.com/rust-lang/rust-bindgen/issues/3179 [1]
Link: https://lore.kernel.org/rust-for-linux/87tt7md1s6.fsf@kernel.org/ [2]
Acked-by: Andreas Hindborg 
Link: https://lore.kernel.org/r/20250325184309.97170-1-ojeda@kernel.org
[ Added extra paragraph on the comment to clarify that the workaround may
  not be possible in some cases. - Miguel ]
Signed-off-by: Miguel Ojeda

rust: hrtimer: Add Ktime temporarily

2025-04-29T13:31:07+00:00

Add Ktime temporarily until hrtimer is refactored to use Instant and
Delta types.

Reviewed-by: Andreas Hindborg 
Reviewed-by: Boqun Feng 
Signed-off-by: FUJITA Tomonori 
Link: https://lore.kernel.org/r/20250423192857.199712-2-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg

Merge tag 'rust-hrtimer-for-v6.15-v3' of https://github.com/Rust-for-Linux/linux into rust-next

2025-03-25T22:41:14+00:00

Pull rust-hrtimer updates from Andreas Hindborg:
 "Introduce Rust support for the 'hrtimer' subsystem:

   - Add a way to use the 'hrtimer' subsystem from Rust. Rust code can
     now set up intrusive timers without allocating when starting the
     timer.

   - Add support for 'Pin>', 'Arc<_>', 'Pin<&_>' and
     'Pin<&mut _>' as pointer types for use with timer callbacks.

   - Add support for setting clock source and timer mode.

  'kernel' crate:

   - Add 'Arc::as_ptr' for converting an 'Arc' to a raw pointer. This is
     a dependency for the 'hrtimer' API.

   - Add 'Box::into_pin' for converting a 'Box<_>' into a 'Pin>'
     to align with Rust 'alloc'. This is a dependency for the 'hrtimer'
     API."

* tag 'rust-hrtimer-for-v6.15-v3' of https://github.com/Rust-for-Linux/linux:
  rust: hrtimer: add maintainer entry
  rust: hrtimer: add clocksource selection through `ClockId`
  rust: hrtimer: add `HrTimerMode`
  rust: hrtimer: implement `HrTimerPointer` for `Pin>`
  rust: alloc: add `Box::into_pin`
  rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`
  rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`
  rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`
  rust: hrtimer: add `UnsafeHrTimerPointer`
  rust: hrtimer: allow timer restart from timer handler
  rust: hrtimer: implement `HrTimerPointer` for `Arc`
  rust: sync: add `Arc::as_ptr`
  rust: hrtimer: introduce hrtimer support

rust: hrtimer: add clocksource selection through `ClockId`

2025-03-22T11:08:54+00:00

Allow selecting a clock source for timers by passing a `ClockId`
variant to `HrTimer::new`.

Acked-by: Frederic Weisbecker 
Acked-by: Thomas Gleixner 
Reviewed-by: Lyude Paul 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-12-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg

rust: hrtimer: add `HrTimerMode`

2025-03-22T11:08:54+00:00

Allow selection of timer mode by passing a `HrTimerMode` variant to
`HrTimer::new`.

Acked-by: Frederic Weisbecker 
Acked-by: Thomas Gleixner 
Reviewed-by: Lyude Paul 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-11-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg

rust: hrtimer: implement `HrTimerPointer` for `Pin>`

2025-03-22T11:08:54+00:00

Allow `Pin>` to be the target of a timer callback.

Acked-by: Frederic Weisbecker 
Acked-by: Thomas Gleixner 
Reviewed-by: Lyude Paul 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-10-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg

rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`

2025-03-22T11:08:54+00:00

Allow pinned mutable references to structs that contain a `HrTimer` node to
be scheduled with the `hrtimer` subsystem.

Acked-by: Frederic Weisbecker 
Acked-by: Thomas Gleixner 
Reviewed-by: Lyude Paul 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-8-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg

rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`

2025-03-22T11:08:54+00:00

Allow pinned references to structs that contain a `HrTimer` node to be
scheduled with the `hrtimer` subsystem.

Acked-by: Frederic Weisbecker 
Acked-by: Thomas Gleixner 
Reviewed-by: Lyude Paul 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-7-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg

rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`

2025-03-22T11:08:54+00:00

Add the trait `ScopedHrTimerPointer` to allow safe use of stack allocated
timers. Safety is achieved by pinning the stack in place while timers are
running.

Implement the trait for all types that implement `UnsafeHrTimerPointer`.

Acked-by: Frederic Weisbecker 
Acked-by: Thomas Gleixner 
Reviewed-by: Benno Lossin 
Reviewed-by: Lyude Paul 
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-6-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg