linux-toradex.git/rust/kernel/sync.rs, branch v6.19

Merge tag 'modules-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux

2025-12-06T16:27:07+00:00

Pull module updates from Daniel Gomez:
 "Rust module parameter support:

   - Add Rust module parameter support, enabling Rust kernel modules to
     declare and use module parameters. The rust_minimal sample module
     demonstrates this, and the rust null block driver will be the first
     to use it in the next cycle. This also adds the Rust module files
     under the modules subsystem as agreed between the Rust and modules
     maintainers.

  Hardening:

   - Add compile-time check for embedded NUL characters in MODULE_*()
     macros. This module metadata was once used (and maybe still) to
     bypass license enforcement (LWN article from 2003):

	https://lwn.net/Articles/82305/ [1]

  MAINTAINERS:

   - Add Aaron Tomlin as reviewer for the Modules subsystem"

* tag 'modules-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
  MAINTAINERS: Add myself as reviewer for module support
  module: Add compile-time check for embedded NUL characters
  media: radio: si470x: Fix DRIVER_AUTHOR macro definition
  media: dvb-usb-v2: lmedm04: Fix firmware macro definitions
  modules: add rust modules files to MAINTAINERS
  rust: samples: add a module parameter to the rust_minimal sample
  rust: module: update the module macro with module parameter support
  rust: module: use a reference in macros::module::module
  rust: introduce module_param module
  rust: str: add radix prefixed integer parsing functions
  rust: sync: add `SetOnce`

rust: sync: replace `kernel::c_str!` with C-Strings

2025-11-19T21:41:12+00:00

C-String literals were added in Rust 1.77. Replace instances of
`kernel::c_str!` with C-String literals where possible.

Acked-by: Greg Kroah-Hartman 
Reviewed-by: Alice Ryhl 
Reviewed-by: Benno Lossin 
Signed-off-by: Tamir Duberstein 
Link: https://patch.msgid.link/20251117-core-cstr-cstrings-v4-1-924886ad9f75@gmail.com
Signed-off-by: Miguel Ojeda

rust: sync: add `SetOnce`

2025-11-03T13:40:35+00:00

Introduce the `SetOnce` type, a container that can only be written once.
The container uses an internal atomic to synchronize writes to the internal
value.

Reviewed-by: Alice Ryhl 
Reviewed-by: Benno Lossin 
Signed-off-by: Andreas Hindborg 
Tested-by: Daniel Gomez 
Signed-off-by: Daniel Gomez

rust: implement `kernel::sync::Refcount`

2025-09-15T07:38:35+00:00

This is a wrapping layer of `include/linux/refcount.h`. Currently the
kernel refcount has already been used in `Arc`, however it calls into
FFI directly.

[boqun: Add the missing <> for the link in comment]
Signed-off-by: Gary Guo 
Signed-off-by: Boqun Feng 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Fiona Behrens 
Reviewed-by: Benno Lossin 
Reviewed-by: Elle Rhumsaa 
Link: https://lore.kernel.org/r/20250723233312.3304339-2-gary@kernel.org

rust: sync: Add memory barriers

2025-09-15T07:38:34+00:00

Memory barriers are building blocks for concurrent code, hence provide
a minimal set of them.

The compiler barrier, barrier(), is implemented in inline asm instead of
using core::sync::atomic::compiler_fence() because memory models are
different: kernel's atomics are implemented in inline asm therefore the
compiler barrier should be implemented in inline asm as well. Also it's
currently only public to the kernel crate until there's a reasonable
driver usage.

Signed-off-by: Boqun Feng 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Alice Ryhl 
Reviewed-by: Elle Rhumsaa 
Link: https://lore.kernel.org/all/20250719030827.61357-10-boqun.feng@gmail.com/

rust: sync: Add basic atomic operation mapping framework

2025-09-15T07:38:32+00:00

Preparation for generic atomic implementation. To unify the
implementation of a generic method over `i32` and `i64`, the C side
atomic methods need to be grouped so that in a generic method, they can
be referred as ::, otherwise their parameters and return
value are different between `i32` and `i64`, which would require using
`transmute()` to unify the type into a `T`.

Introduce `AtomicImpl` to represent a basic type in Rust that has the
direct mapping to an atomic implementation from C. Use a sealed trait to
restrict `AtomicImpl` to only support `i32` and `i64` for now.

Further, different methods are put into different `*Ops` trait groups,
and this is for the future when smaller types like `i8`/`i16` are
supported but only with a limited set of API (e.g. only set(), load(),
xchg() and cmpxchg(), no add() or sub() etc).

While the atomic mod is introduced, documentation is also added for
memory models and data races.

Also bump my role to the maintainer of ATOMIC INFRASTRUCTURE to reflect
my responsibility on the Rust atomic mod.

Signed-off-by: Boqun Feng 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Alice Ryhl 
Reviewed-by: Benno Lossin 
Reviewed-by: Elle Rhumsaa 
Link: https://lore.kernel.org/all/20250719030827.61357-3-boqun.feng@gmail.com/

rust: kernel: move ARef and AlwaysRefCounted to sync::aref

2025-07-22T11:52:14+00:00

Move the definitions of `ARef` and `AlwaysRefCounted` from `types.rs`
to a new file `sync/aref.rs`.  Define the corresponding `aref` module
under `rust/kernel/sync.rs`.  These types are better grouped in `sync`.

To avoid breaking existing imports, they are re-exported from `types.rs`.
Drop unused imports `mem::ManuallyDrop`, `ptr::NonNull` from `types.rs`,
they are now only used in `sync/aref.rs`, where they are already imported.

Suggested-by: Benno Lossin 
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20250715110423.334744-1-shankari.ak0208@gmail.com
[ Added missing `///`. Changed module title. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda

rust: sync: fix safety comment for `static_lock_class`

2025-07-22T11:52:14+00:00

The safety comment mentions lockdep -- which from a Rust perspective
isn't important -- and doesn't mention the real reason for why it's
sound to create `LockClassKey` as uninitialized memory.

Signed-off-by: Benno Lossin 
Reviewed-by: Alice Ryhl 
Link: https://lore.kernel.org/r/20250520231714.323931-1-lossin@kernel.org
Signed-off-by: Miguel Ojeda

rust: Use consistent "# Examples" heading style in rustdoc

2025-06-23T23:02:30+00:00

Use a consistent `# Examples` heading in rustdoc across the codebase.

Some modules previously used `## Examples` (even when they should be
available as top-level headers), while others used `# Example`, which
deviates from the preferred `# Examples` style.

Suggested-by: Miguel Ojeda 
Signed-off-by: Viresh Kumar 
Acked-by: Benno Lossin 
Link: https://lore.kernel.org/r/ddd5ce0ac20c99a72a4f1e4322d3de3911056922.1749545815.git.viresh.kumar@linaro.org
Signed-off-by: Miguel Ojeda

rust: completion: implement initial abstraction

2025-06-13T21:46:56+00:00

Implement a minimal abstraction for the completion synchronization
primitive.

This initial abstraction only adds complete_all() and
wait_for_completion(), since that is what is required for the subsequent
Devres patch.

Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Juri Lelli 
Cc: Vincent Guittot 
Cc: Dietmar Eggemann 
Cc: Steven Rostedt 
Cc: Ben Segall 
Cc: Mel Gorman 
Cc: Valentin Schneider 
Reviewed-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Acked-by: Miguel Ojeda 
Link: https://lore.kernel.org/r/20250612121817.1621-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich