linux/rust/kernel/lib.rs, branch v6.3

rust: types: introduce `ForeignOwnable`

2023-02-01T12:24:07Z

It was originally called `PointerWrapper`. It is used to convert a Rust object to a pointer representation (void *) that can be stored on the C side, used, and eventually returned to Rust. Signed-off-by: Wedson Almeida Filho Reviewed-by: Vincenzo Palazzo Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Gary Guo Reviewed-by: Andreas Hindborg Signed-off-by: Miguel Ojeda

rust: sync: add support for dispatching on Arc and ArcBorrow.

2023-01-16T22:48:06Z

Trait objects (`dyn T`) require trait `T` to be "object safe". One of the requirements for "object safety" is that the receiver have one of the allowed types. This commit adds `Arc` and `ArcBorrow<'_, T>` to the list of allowed types. Signed-off-by: Wedson Almeida Filho Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Reviewed-by: Vincenzo Palazzo Acked-by: Boqun Feng Signed-off-by: Miguel Ojeda

rust: sync: allow coercion from `Arc` to `Arc`

2023-01-16T21:20:24Z

The coercion is only allowed if `U` is a compatible dynamically-sized type (DST). For example, if we have some type `X` that implements trait `Y`, then this allows `Arc` to be coerced into `Arc`. Suggested-by: Gary Guo Signed-off-by: Wedson Almeida Filho Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Reviewed-by: Vincenzo Palazzo Acked-by: Boqun Feng Signed-off-by: Miguel Ojeda

rust: sync: allow type of `self` to be `Arc` or variants

2023-01-16T21:20:18Z

This allows associated functions whose `self` argument has `Arc` or variants as their type. This, in turn, allows callers to use the dot syntax to make calls. Signed-off-by: Wedson Almeida Filho Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Reviewed-by: Vincenzo Palazzo Acked-by: Boqun Feng Signed-off-by: Miguel Ojeda

rust: sync: add `Arc` for ref-counted allocations

2023-01-16T21:20:03Z

This is a basic implementation of `Arc` backed by C's `refcount_t`. It allows Rust code to idiomatically allocate memory that is ref-counted. Cc: Will Deacon Cc: Peter Zijlstra Cc: Boqun Feng Cc: Mark Rutland Signed-off-by: Wedson Almeida Filho Reviewed-by: Alice Ryhl Reviewed-by: Gary Guo Reviewed-by: Vincenzo Palazzo Acked-by: Boqun Feng Signed-off-by: Miguel Ojeda

rust: types: add `Either` type

2022-12-04T00:59:16Z

Introduce the new `types` module of the `kernel` crate with `Either` as its first type. `Either` is a sum type that always holds either a value of type `L` (`Left` variant) or `R` (`Right` variant). For instance: struct Executor { queue: Either, } Signed-off-by: Wedson Almeida Filho Reviewed-by: Wei Liu [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda

rust: build_assert: add `build_{error,assert}!` macros

2022-12-04T00:59:16Z

Add the `build_error!` and `build_assert!` macros which leverage the previously introduced `build_error` crate. Do so in a new module, called `build_assert`. The former fails the build if the code path calling it can possibly be executed. The latter asserts that a boolean expression is `true` at compile time. In particular, `build_assert!` can be used in some contexts where `static_assert!` cannot: fn f1() { static_assert!(N > 1);` // Error. build_assert!(N > 1); // Build-time check. assert!(N > 1); // Run-time check. } #[inline] fn f2(n: usize) { static_assert!(n > 1); // Error. build_assert!(n > 1); // Build-time check. assert!(n > 1); // Run-time check. } Signed-off-by: Gary Guo Reviewed-by: Wei Liu [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda

rust: static_assert: add `static_assert!` macro

2022-12-04T00:59:16Z

Add the `static_assert!` macro, which is a compile-time assert, similar to the C11 `_Static_assert` and C++11 `static_assert` declarations [1,2]. Do so in a new module, called `static_assert`. For instance: static_assert!(42 > 24); static_assert!(core::mem::size_of::() == 1); const X: &[u8] = b"bar"; static_assert!(X[1] == b'a'); const fn f(x: i32) -> i32 { x + 2 } static_assert!(f(40) == 42); Link: https://en.cppreference.com/w/c/language/_Static_assert [1] Link: https://en.cppreference.com/w/cpp/language/static_assert [2] Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Signed-off-by: Miguel Ojeda

rust: std_vendor: add `dbg!` macro based on `std`'s one

2022-12-04T00:59:16Z

The Rust standard library has a really handy macro, `dbg!` [1,2]. It prints the source location (filename and line) along with the raw source code that is invoked with and the `Debug` representation of the given expression, e.g.: let a = 2; let b = dbg!(a * 2) + 1; // ^-- prints: [src/main.rs:2] a * 2 = 4 assert_eq!(b, 5); Port the macro over to the `kernel` crate inside a new module called `std_vendor`, using `pr_info!` instead of `eprintln!` and make the rules about committing uses of `dbg!` into version control more concrete (i.e. tailored for the kernel). Since the source code for the macro is taken from the standard library source (with only minor adjustments), the new file is licensed under `Apache 2.0 OR MIT`, just like the original [3,4]. Link: https://doc.rust-lang.org/std/macro.dbg.html [1] Link: https://github.com/rust-lang/rust/blob/master/library/std/src/macros.rs#L212 [2] Link: https://github.com/rust-lang/rust/blob/master/library/std/Cargo.toml [3] Link: https://github.com/rust-lang/rust/blob/master/COPYRIGHT [4] Signed-off-by: Niklas Mohrin [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda

rust: error: add `From` implementations for `Error`

2022-12-04T00:59:15Z

Add a set of `From` implementations for the `Error` kernel type. These implementations allow to easily convert from standard Rust error types to the usual kernel errors based on one of the `E*` integer codes. On top of that, the question mark Rust operator (`?`) implicitly performs a conversion on the error value using the `From` trait when propagating. Thus it is extra convenient to use. For instance, a kernel function that needs to convert a `i64` into a `i32` and to bubble up the error as a kernel error may write: fn f(x: i64) -> Result<...> { ... let y = i32::try_from(x)?; ... } which will transform the `TryFromIntError` into an `Err(EINVAL)`. Co-developed-by: Adam Bratschi-Kaye Signed-off-by: Adam Bratschi-Kaye Co-developed-by: Nándor István Krácser Signed-off-by: Nándor István Krácser Signed-off-by: Wedson Almeida Filho Reviewed-by: Finn Behrens [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda