Make the `#[pin_data]` macro generate a `*Projection` struct that holds
either `Pin<&mut Field>` or `&mut Field` for every field of the original
struct. Which version is chosen depends on weather there is a `#[pin]`
or not respectively. Access to this projected version is enabled through
generating `fn project(self: Pin<&mut Self>) -> SelfProjection<'_>`.
[ Adapt workqueue to use the new projection instead of its own, custom
one - Benno ]
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Benno Lossin <lossin@kernel.org>
This patch is being sent for use in the various Rust GPU drivers that
are under development. It provides the additional feature of work items
that are executed after a delay.
The design of the existing workqueue is rather extensible, as most of
the logic is reused for delayed work items even though a different work
item type is required. The new logic consists of:
* A new DelayedWork struct that wraps struct delayed_work.
* A new impl_has_delayed_work! macro that provides adjusted versions of
the container_of logic, that is suitable with delayed work items.
* A `enqueue_delayed` method that can enqueue a delayed work item.
This patch does *not* rely on the fact that `struct delayed_work`
contains `struct work_struct` at offset zero. It will continue to work
even if the layout is changed to hold the `work` field at a different
offset.
Please see the example introduced at the top of the file for example
usage of delayed work items.
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250711-workqueue-delay-v3-1-3fe17b18b9d1@google.com
[ Replaced `as _` with `as ffi::c_int` to clean warning. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In the previous patch we added Opaque::cast_from() that performs the
opposite operation to Opaque::raw_get(). For consistency with this
naming, rename raw_get() to cast_from().
There are a few other options such as calling cast_from() something
closer to raw_get() rather than renaming this method. However, I could
not find a great naming scheme that works with raw_get(). The previous
version of this patch used from_raw(), but functions of that name
typically have a different signature, so that's not a great option.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Benno Lossin <lossin@kernel.org>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-2-e4da40bdc59c@google.com
[ Removed `HrTimer::raw_get` change. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In Rust 1.63.0, Clippy introduced the `as_underscore` lint [1]:
> The conversion might include lossy conversion or a dangerous cast that
> might go undetected due to the type being inferred.
>
> The lint is allowed by default as using `_` is less wordy than always
> specifying the type.
Always specifying the type is especially helpful in function call
contexts where the inferred type may change at a distance. Specifying
the type also allows Clippy to spot more cases of `useless_conversion`.
The primary downside is the need to specify the type in trivial getters.
There are 4 such functions: 3 have become slightly less ergonomic, 1 was
revealed to be a `useless_conversion`.
While this doesn't eliminate unchecked `as` conversions, it makes such
conversions easier to scrutinize. It also has the slight benefit of
removing a degree of freedom on which to bikeshed. Thus apply the
changes and enable the lint -- no functional change intended.
Link: https://rust-lang.github.io/rust-clippy/master/index.html#as_underscore [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-4-f43b024581e8@gmail.com
[ Changed `isize` to `c_long`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In Rust 1.51.0, Clippy introduced the `ptr_as_ptr` lint [1]:
> Though `as` casts between raw pointers are not terrible,
> `pointer::cast` is safer because it cannot accidentally change the
> pointer's mutability, nor cast the pointer to other types like `usize`.
There are a few classes of changes required:
- Modules generated by bindgen are marked
`#[allow(clippy::ptr_as_ptr)]`.
- Inferred casts (` as _`) are replaced with `.cast()`.
- Ascribed casts (` as *... T`) are replaced with `.cast::<T>()`.
- Multistep casts from references (` as *const _ as *const T`) are
replaced with `core::ptr::from_ref(&x).cast()` with or without `::<T>`
according to the previous rules. The `core::ptr::from_ref` call is
required because `(x as *const _).cast::<T>()` results in inference
failure.
- Native literal C strings are replaced with `c_str!().as_char_ptr()`.
- `*mut *mut T as _` is replaced with `let *mut *const T = (*mut *mut
T)`.cast();` since pointer to pointer can be confusing.
Apply these changes and enable the lint -- no functional change
intended.
Link: https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-1-f43b024581e8@gmail.com
[ Added `.cast()` for `opp`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull workqueue update from Tejun Heo:
"Just one commit to expose system BH workqueues to rust"
* tag 'wq-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
rust: workqueue: define built-in bh queues
Provide safe getters to the system bh work queues. They will be used
to reimplement the Hyper-V VMBus in rust.
Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Finish the move to custom FFI integer types started in the previous
cycle and finally map 'long' to 'isize' and 'char' to 'u8'. Do a
few cleanups on top thanks to that.
- Start to use 'derive(CoercePointee)' on Rust >= 1.84.0.
This is a major milestone on the path to build the kernel using
only stable Rust features. In particular, previously we were using
the unstable features 'coerce_unsized', 'dispatch_from_dyn' and
'unsize', and now we will use the new 'derive_coerce_pointee' one,
which is on track to stabilization. This new feature is a macro
that essentially expands into code that internally uses the
unstable features that we were using before, without having to
expose those.
With it, stable Rust users, including the kernel, will be able to
build custom smart pointers that work with trait objects, e.g.:
fn f(p: &Arc<dyn Display>) {
pr_info!("{p}\n");
}
let a: Arc<dyn Display> = Arc::new(42i32, GFP_KERNEL)?;
let b: Arc<dyn Display> = Arc::new("hello there", GFP_KERNEL)?;
f(&a); // Prints "42".
f(&b); // Prints "hello there".
Together with the 'arbitrary_self_types' feature that we started
using in the previous cycle, using our custom smart pointers like
'Arc' will eventually only rely in stable Rust.
- Introduce 'PROCMACROLDFLAGS' environment variable to allow to link
Rust proc macros using different flags than those used for linking
Rust host programs (e.g. when 'rustc' uses a different C library
than the host programs' one), which Android needs.
- Help kernel builds under macOS with Rust enabled by accomodating
other naming conventions for dynamic libraries (i.e. '.so' vs.
'.dylib') which are used for Rust procedural macros. The actual
support for macOS (i.e. the rest of the pieces needed) is provided
out-of-tree by others, following the policy used for other parts of
the kernel by Kbuild.
- Run Clippy for 'rusttest' code too and clean the bits it spotted.
- Provide Clippy with the minimum supported Rust version to improve
the suggestions it gives.
- Document 'bindgen' 0.71.0 regression.
'kernel' crate:
- 'build_error!': move users of the hidden function to the documented
macro, prevent such uses in the future by moving the function
elsewhere and add the macro to the prelude.
- 'types' module: add improved version of 'ForeignOwnable::borrow_mut'
(which was removed in the past since it was problematic); change
'ForeignOwnable' pointer type to '*mut'.
- 'alloc' module: implement 'Display' for 'Box' and align the 'Debug'
implementation to it; add example (doctest) for 'ArrayLayout::new()'
- 'sync' module: document 'PhantomData' in 'Arc'; use
'NonNull::new_unchecked' in 'ForeignOwnable for Arc' impl.
- 'uaccess' module: accept 'Vec's with different allocators in
'UserSliceReader::read_all'.
- 'workqueue' module: enable run-testing a couple more doctests.
- 'error' module: simplify 'from_errno()'.
- 'block' module: fix formatting in code documentation (a lint to catch
these is being implemented).
- Avoid 'unwrap()'s in doctests, which also improves the examples by
showing how kernel code is supposed to be written.
- Avoid 'as' casts with 'cast{,_mut}' calls which are a bit safer.
And a few other cleanups"
* tag 'rust-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (32 commits)
kbuild: rust: add PROCMACROLDFLAGS
rust: uaccess: generalize userSliceReader to support any Vec
rust: kernel: add improved version of `ForeignOwnable::borrow_mut`
rust: kernel: reorder `ForeignOwnable` items
rust: kernel: change `ForeignOwnable` pointer to mut
rust: arc: split unsafe block, add missing comment
rust: types: avoid `as` casts
rust: arc: use `NonNull::new_unchecked`
rust: use derive(CoercePointee) on rustc >= 1.84.0
rust: alloc: add doctest for `ArrayLayout::new()`
rust: init: update `stack_try_pin_init` examples
rust: error: import `kernel`'s `LayoutError` instead of `core`'s
rust: str: replace unwraps with question mark operators
rust: page: remove unnecessary helper function from doctest
rust: rbtree: remove unwrap in asserts
rust: init: replace unwraps with question mark operators
rust: use host dylib naming convention to support macOS
rust: add `build_error!` to the prelude
rust: kernel: move `build_error` hidden function to prevent mistakes
rust: use the `build_error!` macro, not the hidden function
...
Having the Rust doctests enabled these workqueue tests are built but not
executed as the final callers of the print_*() functions are missing.
Add them.
The result is
# rust_doctest_kernel_workqueue_rs_0.location: rust/kernel/workqueue.rs:35
rust_doctests_kernel: The value is: 42
ok 94 rust_doctest_kernel_workqueue_rs_0
# rust_doctest_kernel_workqueue_rs_3.location: rust/kernel/workqueue.rs:78
rust_doctests_kernel: The value is: 24
rust_doctests_kernel: The second value is: 42
ok 97 rust_doctest_kernel_workqueue_rs_3
Without this change the "The value ..." outputs are not there meaning
that this test code is not run.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/cb953202-0dbe-4127-8a8e-6a75258c2116@gmail.com
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Rust's `unused_imports` lint covers both unused and redundant imports.
In the upcoming 1.78.0, the lint detects more cases of redundant imports
[1], e.g.:
error: the item `bindings` is imported redundantly
--> rust/kernel/print.rs:38:9
|
38 | use crate::bindings;
| ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude
Most cases are `use crate::bindings`, plus a few other items like `Box`.
Thus clean them up.
Note that, in the `bindings` case, the message "defined by prelude"
above means the extern prelude, i.e. the `--extern` flags we pass.
Link: https://github.com/rust-lang/rust/pull/117772 [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240401212303.537355-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
