user/sven/linux.git/rust/kernel/sync, branch v6.18.8

rust: condvar: fix broken intra-doc link

2025-11-02T22:18:42Z

The future move of pin-init to `syn` uncovers the following broken intra-doc link: error: unresolved link to `crate::pin_init` --> rust/kernel/sync/condvar.rs:39:40 | 39 | /// instances is with the [`pin_init`](crate::pin_init!) and [`new_condvar`] macros. | ^^^^^^^^^^^^^^^^ no item named `pin_init` in module `kernel` | = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]` Currently, when rendered, the link points to a literal `crate::pin_init!` URL. Thus fix it. Cc: stable@vger.kernel.org Fixes: 129e97be8e28 ("rust: pin-init: fix documentation links") Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20251029073344.349341-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda

Merge tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2025-10-01T02:12:49Z

Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Derive 'Zeroable' for all structs and unions generated by 'bindgen' where possible and corresponding cleanups. To do so, add the 'pin-init' crate as a dependency to 'bindings' and 'uapi'. It also includes its first use in the 'cpufreq' module, with more to come in the next cycle. - Add warning to the 'rustdoc' target to detect broken 'srctree/' links and fix existing cases. - Remove support for unused (since v6.16) host '#[test]'s, simplifying the 'rusttest' target. Tests should generally run within KUnit. 'kernel' crate: - Add 'ptr' module with a new 'Alignment' type, which is always a power of two and is used to validate that a given value is a valid alignment and to perform masking and alignment operations: // Checked at build time. assert_eq!(Alignment::new::<16>().as_usize(), 16); // Checked at runtime. assert_eq!(Alignment::new_checked(15), None); assert_eq!(Alignment::of::().log2(), 0); assert_eq!(0x25u8.align_down(Alignment::new::<0x10>()), 0x20); assert_eq!(0x5u8.align_up(Alignment::new::<0x10>()), Some(0x10)); assert_eq!(u8::MAX.align_up(Alignment::new::<0x10>()), None); It also includes its first use in Nova. - Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching Rust 1.80.0. - Keep going with the steps on our migration to the standard library 'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use upstream method names). - 'error' module: improve 'Error::from_errno' and 'to_result' documentation, including examples/tests. - 'sync' module: extend 'aref' submodule documentation now that it exists, and more updates to complete the ongoing move of 'ARef' and 'AlwaysRefCounted' to 'sync::aref'. - 'list' module: add an example/test for 'ListLinksSelfPtr' usage. - 'alloc' module: - Implement 'Box::pin_slice()', which constructs a pinned slice of elements. - Provide information about the minimum alignment guarantees of 'Kmalloc', 'Vmalloc' and 'KVmalloc'. - Take minimum alignment guarantees of allocators for 'ForeignOwnable' into account. - Remove the 'allocator_test' (including 'Cmalloc'). - Add doctest for 'Vec::as_slice()'. - Constify various methods. - 'time' module: - Add methods on 'HrTimer' that can only be called with exclusive access to an unarmed timer, or from timer callback context. - Add arithmetic operations to 'Instant' and 'Delta'. - Add a few convenience and access methods to 'HrTimer' and 'Instant'. 'macros' crate: - Reduce collections in 'quote!' macro. And a few other cleanups and improvements" * tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (58 commits) gpu: nova-core: use Alignment for alignment-related operations rust: add `Alignment` type rust: macros: reduce collections in `quote!` macro rust: acpi: use `core::ffi::CStr` method names rust: of: use `core::ffi::CStr` method names rust: net: use `core::ffi::CStr` method names rust: miscdevice: use `core::ffi::CStr` method names rust: kunit: use `core::ffi::CStr` method names rust: firmware: use `core::ffi::CStr` method names rust: drm: use `core::ffi::CStr` method names rust: cpufreq: use `core::ffi::CStr` method names rust: configfs: use `core::ffi::CStr` method names rust: auxiliary: use `core::ffi::CStr` method names drm/panic: use `core::ffi::CStr` method names rust: device: use `kernel::{fmt,prelude::fmt!}` rust: sync: use `kernel::{fmt,prelude::fmt!}` rust: seq_file: use `kernel::{fmt,prelude::fmt!}` rust: kunit: use `kernel::{fmt,prelude::fmt!}` rust: file: use `kernel::{fmt,prelude::fmt!}` rust: device: use `kernel::{fmt,prelude::fmt!}` ...

rust: sync: use `kernel::{fmt,prelude::fmt!}`

2025-09-16T07:26:59Z

Reduce coupling to implementation details of the formatting machinery by avoiding direct use for `core`'s formatting traits and macros. Acked-by: Greg Kroah-Hartman Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Signed-off-by: Tamir Duberstein Signed-off-by: Miguel Ojeda

rust: block: convert `block::mq` to use `Refcount`

2025-09-15T07:38:36Z

Currently there's a custom reference counting in `block::mq`, which uses `AtomicU64` Rust atomics, and this type doesn't exist on some 32-bit architectures. We cannot just change it to use 32-bit atomics, because doing so will make it vulnerable to refcount overflow. So switch it to use the kernel refcount `kernel::sync::Refcount` instead. There is an operation needed by `block::mq`, atomically decreasing refcount from 2 to 0, which is not available through refcount.h, so I exposed `Refcount::as_atomic` which allows accessing the refcount directly. [boqun: Adopt the LKMM atomic API] Signed-off-by: Gary Guo Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Benno Lossin Reviewed-by: Elle Rhumsaa Acked-by: Andreas Hindborg Tested-by: David Gow Link: https://lore.kernel.org/r/20250723233312.3304339-5-gary@kernel.org

rust: convert `Arc` to use `Refcount`

2025-09-15T07:38:35Z

With `Refcount` type created, `Arc` can use `Refcount` instead of calling into FFI directly. Signed-off-by: Gary Guo Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alexandre Courbot Reviewed-by: Benno Lossin Reviewed-by: Elle Rhumsaa Link: https://lore.kernel.org/r/20250723233312.3304339-4-gary@kernel.org

rust: make `Arc::into_unique_or_drop` associated function

2025-09-15T07:38:35Z

Make `Arc::into_unique_or_drop` to become a mere associated function instead of a method (i.e. removing the `self` receiver). It's a general convention for Rust smart pointers to avoid having methods defined on them, because if the pointee type has a method of the same name, then it is shadowed. This is normally for avoiding semver breakage, which isn't an issue for kernel codebase, but it's still generally a good practice to follow this rule, so that `ptr.foo()` would always be calling a method on the pointee type. Signed-off-by: Gary Guo Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Benno Lossin Reviewed-by: Alexandre Courbot Reviewed-by: Elle Rhumsaa Link: https://lore.kernel.org/r/20250723233312.3304339-3-gary@kernel.org

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

2025-09-15T07:38:35Z

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

2025-09-15T07:38:34Z

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: atomic: Add Atomic<{usize,isize}>

2025-09-15T07:38:34Z

Add generic atomic support for `usize` and `isize`. Note that instead of mapping directly to `atomic_long_t`, the represention type (`AtomicType::Repr`) is selected based on CONFIG_64BIT. This reduces the necessity of creating `atomic_long_*` helpers, which could save the binary size of kernel if inline helpers are not available. To do so, an internal type `isize_atomic_repr` is defined, it's `i32` in 32bit kernel and `i64` in 64bit kernel. Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alice Ryhl Reviewed-by: Andreas Hindborg Reviewed-by: Benno Lossin Reviewed-by: Elle Rhumsaa Link: https://lore.kernel.org/all/20250719030827.61357-9-boqun.feng@gmail.com/

rust: sync: atomic: Add Atomic

2025-09-15T07:38:34Z

Add generic atomic support for basic unsigned types that have an `AtomicImpl` with the same size and alignment. Unit tests are added including Atomic and Atomic. Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alice Ryhl Reviewed-by: Andreas Hindborg Reviewed-by: Benno Lossin Reviewed-by: Elle Rhumsaa Link: https://lore.kernel.org/all/20250719030827.61357-8-boqun.feng@gmail.com/