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2024-03-11Merge tag 'wq-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "This cycle, a lot of workqueue changes including some that are significant and invasive. - During v6.6 cycle, unbound workqueues were updated so that they are more topology aware and flexible, which among other things improved workqueue behavior on modern multi-L3 CPUs. In the process, commit 636b927eba5b ("workqueue: Make unbound workqueues to use per-cpu pool_workqueues") switched unbound workqueues to use per-CPU frontend pool_workqueues as a part of increasing front-back mapping flexibility. An unwelcome side effect of this change was that this made max concurrency enforcement per-CPU blowing up the maximum number of allowed concurrent executions. I incorrectly assumed that this wouldn't cause practical problems as most unbound workqueue users are self-regulate max concurrency; however, there definitely are which don't (e.g. on IO paths) and the drastic increase in the allowed max concurrency led to noticeable perf regressions in some use cases. This is now addressed by separating out max concurrency enforcement to a separate struct - wq_node_nr_active - which makes @max_active consistently mean system-wide max concurrency regardless of the number of CPUs or (finally) NUMA nodes. This is a rather invasive and, in places, a bit clunky; however, the clunkiness rises from the the inherent requirement to handle the disagreement between the execution locality domain and max concurrency enforcement domain on some modern machines. See commit 5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues") for more details. - BH workqueue support is added. They are similar to per-CPU workqueues but execute work items in the softirq context. This is expected to replace tasklet. However, currently, it's missing the ability to disable and enable work items which is needed to convert many tasklet users. To avoid crowding this merge window too much, this will be included in the next merge window. A separate pull request will be sent for the couple conversion patches that are currently pending. - Waiman plugged a long-standing hole in workqueue CPU isolation where ordered workqueues didn't follow wq_unbound_cpumask updates. Ordered workqueues now follow the same rules as other unbound workqueues. - More CPU isolation improvements: Juri fixed another deficit in workqueue isolation where unbound rescuers don't respect wq_unbound_cpumask. Leonardo fixed delayed_work timers firing on isolated CPUs. - Other misc changes" * tag 'wq-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (54 commits) workqueue: Drain BH work items on hot-unplugged CPUs workqueue: Introduce from_work() helper for cleaner callback declarations workqueue: Control intensive warning threshold through cmdline workqueue: Make @flags handling consistent across set_work_data() and friends workqueue: Remove clear_work_data() workqueue: Factor out work_grab_pending() from __cancel_work_sync() workqueue: Clean up enum work_bits and related constants workqueue: Introduce work_cancel_flags workqueue: Use variable name irq_flags for saving local irq flags workqueue: Reorganize flush and cancel[_sync] functions workqueue: Rename __cancel_work_timer() to __cancel_timer_sync() workqueue: Use rcu_read_lock_any_held() instead of rcu_read_lock_held() workqueue: Cosmetic changes workqueue, irq_work: Build fix for !CONFIG_IRQ_WORK workqueue: Fix queue_work_on() with BH workqueues async: Use a dedicated unbound workqueue with raised min_active workqueue: Implement workqueue_set_min_active() workqueue: Fix kernel-doc comment of unplug_oldest_pwq() workqueue: Bind unbound workqueue rescuer to wq_unbound_cpumask kernel/workqueue: Let rescuers follow unbound wq cpumask changes ...
2024-02-25rust: add `container_of!` macroWedson Almeida Filho
This macro is used to obtain a pointer to an entire struct when given a pointer to a field in that struct. Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Matt Gilbride <mattgilbride@google.com> Link: https://lore.kernel.org/r/20240219-b4-rbtree-v2-1-0b113aab330d@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-25rust: str: implement `Display` and `Debug` for `BStr`Yutaro Ohno
Currently, `BStr` is just a type alias of `[u8]`, limiting its representation to a byte list rather than a character list, which is not ideal for printing and debugging. Implement `Display` and `Debug` traits for `BStr` to facilitate easier printing and debugging. Also, for this purpose, change `BStr` from a type alias of `[u8]` to a struct wrapper of `[u8]`. Co-developed-by: Virgile Andreani <armavica@ulminfo.fr> Signed-off-by: Virgile Andreani <armavica@ulminfo.fr> Signed-off-by: Yutaro Ohno <yutaro.ono.418@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/ZcSlGMGP-e9HqybA@ohnotp [ Formatted code comment. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-25rust: types: add `try_from_foreign()` methodObei Sideg
Currently `ForeignOwnable::from_foreign()` only works for non-null pointers for the existing `impl`s (e.g. `Box`, `Arc`). In turn, this means callers may write code like: ```rust // `p` is a pointer that may be null. if p.is_null() { None } else { unsafe { Some(Self::from_foreign(ptr)) } } ``` Add a `try_from_foreign()` method to the trait with a default implementation that returns `None` if `ptr` is null, otherwise `Some(from_foreign(ptr))`, so that it can be used by callers instead. Link: https://github.com/Rust-for-Linux/linux/issues/1057 Signed-off-by: Obei Sideg <linux@obei.io> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Link: https://lore.kernel.org/r/0100018d53f737f8-80c1fe97-0019-40d7-ab69-b1b192785cd7-000000@email.amazonses.com [ Fixed intra-doc links, improved `SAFETY` comment and reworded commit. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: stop using ptr_metadata featureAlice Ryhl
The `byte_sub` method was stabilized in Rust 1.75.0. By using that method, we no longer need the unstable `ptr_metadata` feature for implementing `Arc::from_raw`. This brings us one step closer towards not using unstable compiler features. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240215104601.1267763-1-aliceryhl@google.com [ Reworded title. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add reexports for macrosAlice Ryhl
Currently, all macros are reexported with #[macro_export] only, which means that to access `new_work!` from the workqueue, you need to import it from the path `kernel::new_work` instead of importing it from the workqueue module like all other items in the workqueue. By adding reexports of the macros, it becomes possible to import the macros from the correct modules. It's still possible to import the macros from the root, but I don't think we can do anything about that. There is no functional change. This is merely a code cleanliness improvement. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240129145837.1419880-1-aliceryhl@google.com [ Removed new `use kernel::prelude::*`s, reworded title. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: locked_by: shorten doclink previewValentin Obst
Increases readability by removing `super::` from the link preview text. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-12-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: remove unneeded doclink targetsValentin Obst
Remove explicit targets for doclinks in cases where rustdoc can determine the correct target by itself. The goal is to reduce unneeded verbosity in the source code. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-11-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add doclinksValentin Obst
Add doclinks to existing documentation. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-10-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add blank lines in front of code blocksValentin Obst
Throughout the code base, blank lines are used before starting a code block. Adapt outliers to improve consistency within the kernel crate. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-9-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: mark code fragments in docs with backticksValentin Obst
Fix places where comments include code fragments that are not enclosed in backticks. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-8-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: unify spelling of refcount in docsValentin Obst
Replace instances of 'ref-count[ed]' with 'refcount[ed]' to increase consistency within the Rust documentation. The latter form is used more widely in the rest of the kernel: ```console $ rg '(\*|//).*?\srefcount(|ed)[\s,.]' | wc -l 1605 $ rg '(\*|//).*?\sref-count(|ed)[\s,.]' | wc -l 43 ``` (numbers are for commit 052d534373b7 ("Merge tag 'exfat-for-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat")) Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-7-0c8af94ed7de@valentinobst.de [ Reworded to use the kernel's commit description style. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: str: move SAFETY comment in front of unsafe blockValentin Obst
SAFETY comments should immediately precede the unsafe block they justify. Move assignment to `bar` past comment as it is safe. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-6-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: str: use `NUL` instead of 0 in doc commentsValentin Obst
Throughout the module, bytes with the value zero are referred to as `NUL` bytes. Adapt the only two outliers. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-5-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add srctree-relative doclinksValentin Obst
Convert existing references to C header files to make use of Commit bc2e7d5c298a ("rust: support `srctree`-relative links"). Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-4-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: ioctl: end top-level module docs with full stopValentin Obst
Every other module ends its first line of documentation with a full stop. Adapt the only outlier. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-3-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: error: improve unsafe code in exampleValentin Obst
The `from_err_ptr` function is safe. There is no need for the call to it to be inside the unsafe block. Reword the SAFETY comment to provide a better justification of why the FFI call is safe. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-2-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: fix multiple typos in documentationValentin Obst
Fixes multiple trivial typos in documentation and comments of the kernel crate. allocator: - Fix a trivial list item alignment issue in the last SAFETY comment of `krealloc_aligned`. init: - Replace 'type' with 'trait' in the doc comments of the `PinInit` and `Init` traits. - Add colons before starting lists. - Add spaces between the type and equal sign to respect the code formatting rules in example code. - End a sentence with a full stop instead of a colon. ioctl: - Replace 'an' with 'a' where appropriate. str: - Replace 'Return' with 'Returns' in the doc comment of `bytes_written` as the text describes what the function does. sync/lock: - Fix a trivial list item alignment issue in the Safety section of the `Backend` trait's description. sync/lock/spinlock: - The code in this module operates on spinlocks, not mutexes. Thus, replace 'mutex' with 'spinlock' in the SAFETY comment of `unlock`. workqueue: - Replace "wont" with "won't" in the doc comment of `__enqueue`. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-1-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-01workqueue: rust: sync with `WORK_CPU_UNBOUND` changeMiguel Ojeda
Commit e563d0a7cdc1 ("workqueue: Break up enum definitions and give names to the types") gives a name to the `enum` where `WORK_CPU_UNBOUND` was defined, so `bindgen` changes its output from e.g.: pub type _bindgen_ty_10 = core::ffi::c_uint; pub const WORK_CPU_UNBOUND: _bindgen_ty_10 = 64; to e.g.: pub type wq_misc_consts = core::ffi::c_uint; pub const wq_misc_consts_WORK_CPU_UNBOUND: wq_misc_consts = 64; Thus update Rust's side to match the change (which requires a slight reformat of the code), fixing the build error. Closes: https://lore.kernel.org/rust-for-linux/CANiq72=9PZ89bCAVX0ZV4cqrYSLoZWyn-d_K4KpBMHjwUMdC3A@mail.gmail.com/ Fixes: e563d0a7cdc1 ("workqueue: Break up enum definitions and give names to the types") Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-01-28rust: sync: update integer types in CondVarAlice Ryhl
Reduce the chances of compilation failures due to integer type mismatches in `CondVar`. When an integer is defined using a #define in C, bindgen doesn't know which integer type it is supposed to be, so it will just use `u32` by default (if it fits in an u32). Whenever the right type is something else, we insert a cast in Rust. However, this means that the code has a lot of extra casts, and sometimes the code will be missing casts if u32 happens to be correct on the developer's machine, even though the type might be something else on a different platform. This patch updates all uses of such constants in `rust/kernel/sync/condvar.rs` to use constants defined with the right type. This allows us to remove various unnecessary casts, while also future-proofing for the case where `unsigned int != u32` (even though that is unlikely to ever happen in the kernel). I wrote this patch at the suggestion of Benno in [1]. Link: https://lore.kernel.org/all/nAEg-6vbtX72ZY3oirDhrSEf06TBWmMiTt73EklMzEAzN4FD4mF3TPEyAOxBZgZtjzoiaBYtYr3s8sa9wp1uYH9vEWRf2M-Lf4I0BY9rAgk=@proton.me/ [1] Suggested-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-4-88e0c871cc05@google.com [ Added note on the unlikeliness of `sizeof(int)` changing. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-28rust: sync: add `CondVar::wait_timeout`Alice Ryhl
Sleep on a condition variable with a timeout. This is used by Rust Binder for process freezing. There, we want to sleep until the freeze operation completes, but we want to be able to abort the process freezing if it doesn't complete within some timeout. Note that it is not enough to avoid jiffies by introducing a variant of `CondVar::wait_timeout` that takes the timeout in msecs because we need to be able to restart the sleep with the remaining sleep duration if it is interrupted, and if the API takes msecs rather than jiffies, then that would require a conversion roundtrip jiffies->msecs->jiffies that is best avoided. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-3-88e0c871cc05@google.com [ Added `CondVarTimeoutResult` re-export and fixed typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-28rust: time: add msecs to jiffies conversionAlice Ryhl
Defines type aliases and conversions for msecs and jiffies. This is used by Rust Binder for process freezing. There, we want to sleep until the freeze operation completes, but we want to be able to abort the process freezing if it doesn't complete within some timeout. The freeze timeout is supplied in msecs. Note that we need to convert to jiffies in Binder. It is not enough to introduce a variant of `CondVar::wait_timeout` that takes the timeout in msecs because we need to be able to restart the sleep with the remaining sleep duration if it is interrupted, and if the API takes msecs rather than jiffies, then that would require a conversion roundtrip jiffies-> msecs->jiffies that is best avoided. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-2-88e0c871cc05@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-28rust: sync: add `CondVar::notify_sync`Alice Ryhl
Wake up another thread synchronously. This method behaves like `notify_one`, except that it hints to the scheduler that the current thread is about to go to sleep, so it should schedule the target thread on the same CPU. This is used by Rust Binder as a performance optimization. When sending a transaction to a different process, we usually know which thread will handle it, so we can schedule that thread for execution next on this CPU for better cache locality. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-1-88e0c871cc05@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-27rust: phy: use VTABLE_DEFAULT_ERRORFUJITA Tomonori
Since 6.8-rc1, using VTABLE_DEFAULT_ERROR for optional functions (never called) in #[vtable] is the recommended way. Note that no functional changes in this patch. Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-27rust: phy: use `srctree`-relative linksFUJITA Tomonori
The relative paths like the following are bothersome and don't work with `O=` builds: //! C headers: [`include/linux/phy.h`](../../../../../../../include/linux/phy.h). This updates such links by using the `srctree`-relative link feature introduced in 6.8-rc1 like: //! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h). Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-22rust: sync: `CondVar` rename "wait_list" to "wait_queue_head"Charalampos Mitrodimas
Fields named "wait_list" usually are of type "struct list_head". To avoid confusion and because it is of type "Opaque<bindings::wait_queue_head>" we are renaming "wait_list" to "wait_queue_head". Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240105012930.1426214-1-charmitro@posteo.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-22rust: upgrade to Rust 1.75.0Miguel Ojeda
This is the next upgrade to the Rust toolchain, from 1.74.1 to 1.75.0 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2"). # Unstable features The `const_maybe_uninit_zeroed` unstable feature [3] was stabilized in Rust 1.75.0, which we were using in the PHYLIB abstractions. The only unstable features allowed to be used outside the `kernel` crate are still `new_uninit,offset_of`, though other code to be upstreamed may increase the list. Please see [4] for details. # Other improvements Rust 1.75.0 stabilized `pointer_byte_offsets` [5] which we could potentially use as an alternative for `ptr_metadata` in the future. # Required changes For this upgrade, no changes were required (i.e. on our side). # `alloc` upgrade and reviewing The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1750-2023-12-28 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/rust-lang/rust/issues/91850 [3] Link: https://github.com/Rust-for-Linux/linux/issues/2 [4] Link: https://github.com/rust-lang/rust/issues/96283 [5] Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20231224172128.271447-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-11Merge tag 'rust-6.8' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull Rust updates from Miguel Ojeda: "Another routine one in terms of features. In terms of lines, this time the 'alloc' version upgrade is less prominent, given that it was fairly small (and we did not have two upgrades) Toolchain and infrastructure: - Upgrade to Rust 1.74.1 The patch release includes a fix for an ICE that the Apple AGX GPU driver was hitting - Support 'srctree'-relative links in Rust code documentation - Automate part of the manual constants handling (i.e. the ones not recognised by 'bindgen') - Suppress searching builtin sysroot to avoid confusion with installed sysroots, needed for the to-be-merged arm64 support which uses a builtin target - Ignore '__preserve_most' functions for 'bindgen' - Reduce header inclusion bloat in exports 'kernel' crate: - Implement 'Debug' for 'CString' - Make 'CondVar::wait()' an uninterruptible wait 'macros' crate: - Update 'paste!' to accept string literals - Improve '#[vtable]' documentation Documentation: - Add testing section (KUnit and 'rusttest' target) - Remove 'CC=clang' mentions - Clarify that 'rustup override' applies to build directory" * tag 'rust-6.8' of https://github.com/Rust-for-Linux/linux: docs: rust: Clarify that 'rustup override' applies to build directory docs: rust: Add rusttest info docs: rust: remove `CC=clang` mentions rust: support `srctree`-relative links rust: sync: Makes `CondVar::wait()` an uninterruptible wait rust: upgrade to Rust 1.74.1 rust: Suppress searching builtin sysroot rust: macros: improve `#[vtable]` documentation rust: macros: update 'paste!' macro to accept string literals rust: bindings: rename const binding using sed rust: Ignore preserve-most functions rust: replace <linux/module.h> with <linux/export.h> in rust/exports.c rust: kernel: str: Implement Debug for CString
2023-12-21rust: support `srctree`-relative linksMiguel Ojeda
Some of our links use relative paths in order to point to files in the source tree, e.g.: //! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h) /// [`struct mutex`]: ../../../../include/linux/mutex.h These are problematic because they are hard to maintain and do not support `O=` builds. Instead, provide support for `srctree`-relative links, e.g.: //! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h) /// [`struct mutex`]: srctree/include/linux/mutex.h The links are fixed after `rustdoc` generation to be based on the absolute path to the source tree. Essentially, this is the automatic version of Tomonori's fix [1], suggested by Gary [2]. Suggested-by: Gary Guo <gary@garyguo.net> Reported-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Closes: https://lore.kernel.org/r/20231026.204058.2167744626131849993.fujita.tomonori@gmail.com [1] Fixes: 48fadf440075 ("docs: Move rustdoc output, cross-reference it") Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2] Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20231215235428.243211-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21rust: sync: Makes `CondVar::wait()` an uninterruptible waitBoqun Feng
Currently, `CondVar::wait()` is an interruptible wait, and this is different than `wait_event()` in include/linux/wait.h (which is an uninterruptible wait). To avoid confusion between different APIs on the interruptible/uninterruptible, make `CondVar::wait()` an uninterruptible wait same as `wait_event()`, also rename the old `wait()` to `CondVar::wait_interruptible()`. Spotted-by: Tiago Lam <tiagolam@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Link: https://lore.kernel.org/r/20231214200421.690629-1-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-15rust: net::phy add module_phy_driver macroFUJITA Tomonori
This macro creates an array of kernel's `struct phy_driver` and registers it. This also corresponds to the kernel's `MODULE_DEVICE_TABLE` macro, which embeds the information for module loading into the module binary file. A PHY driver should use this macro. Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Trevor Gross <tmgross@umich.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-15rust: core abstractions for network PHY driversFUJITA Tomonori
This patch adds abstractions to implement network PHY drivers; the driver registration and bindings for some of callback functions in struct phy_driver and many genphy_ functions. This feature is enabled with CONFIG_RUST_PHYLIB_ABSTRACTIONS=y. This patch enables unstable const_maybe_uninit_zeroed feature for kernel crate to enable unsafe code to handle a constant value with uninitialized data. With the feature, the abstractions can initialize a phy_driver structure with zero easily; instead of initializing all the members by hand. It's supposed to be stable in the not so distant future. Link: https://github.com/rust-lang/rust/pull/116218 Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-14rust: macros: improve `#[vtable]` documentationBenno Lossin
Traits marked with `#[vtable]` need to provide default implementations for optional functions. The C side represents these with `NULL` in the vtable, so the default functions are never actually called. We do not want to replicate the default behavior from C in Rust, because that is not maintainable. Therefore we should use `build_error` in those default implementations. The error message for that is provided at `kernel::error::VTABLE_DEFAULT_ERROR`. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Finn Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/20231026201855.1497680-1-benno.lossin@proton.me [ Wrapped paragraph to 80 as requested and capitalized sentence. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-14rust: bindings: rename const binding using sedGary Guo
Currently, for `const`s that bindgen doesn't recognise, we define a helper constant with const <TYPE> BINDINGS_<NAME> = <NAME>; in `bindings_helper.h` and then we put pub const <NAME>: <TYPE> = BINDINGS_<NAME>; in `bindings/lib.rs`. This is fine since we currently only have 3 constants that are defined this way, but is going to be more annoying when more constants are added since every new constant needs to be defined in two places. This patch changes the way we define constant helpers to const <TYPE> RUST_CONST_HELPER_<NAME> = <NAME>; and then use `sed` to postprocess Rust code generated by bindgen to remove the distinct prefix, so users of the `bindings` crate can refer to the name directly. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231104145700.2495176-1-gary@garyguo.net [ Reworded for typos. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-13rust: kernel: str: Implement Debug for CStringAsahi Lina
Make it possible to use a `CString` with the `pr_*` macros directly. That is, instead of: pr_debug!("trying to open {:?}\n", &*filename); we can now write: pr_debug!("trying to open {:?}\n", filename); Signed-off-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230714-cstring-debug-v1-1-4e7c3018dd4f@asahilina.net [ Reworded to use Alice's commit message as discussed. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-30Merge tag 'wq-for-6.7-rust-bindings' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue rust bindings from Tejun Heo: "Add rust bindings to allow rust code to schedule work items on workqueues. While the current bindings don't cover all of the workqueue API, it provides enough for basic usage and can be expanded as needed" * tag 'wq-for-6.7-rust-bindings' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: rust: workqueue: add examples rust: workqueue: add `try_spawn` helper method rust: workqueue: implement `WorkItemPointer` for pointer types rust: workqueue: add helper for defining work_struct fields rust: workqueue: define built-in queues rust: workqueue: add low-level workqueue bindings rust: sync: add `Arc::{from_raw, into_raw}`
2023-10-30Merge tag 'rust-6.7' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda: "A small one compared to the previous one in terms of features. In terms of lines, as usual, the 'alloc' version upgrade accounts for most of them. Toolchain and infrastructure: - Upgrade to Rust 1.73.0 This time around, due to how the kernel and Rust schedules have aligned, there are two upgrades in fact. They contain the fixes for a few issues we reported to the Rust project. In addition, a few cleanups indicated by the upgraded compiler or possible thanks to it. For instance, the compiler now detects redundant explicit links. - A couple changes to the Rust 'Makefile' so that it can be used with toybox tools, allowing Rust to be used in the Android kernel build. x86: - Enable IBT if enabled in C Documentation: - Add "The Rust experiment" section to the Rust index page MAINTAINERS: - Add Maintainer Entry Profile field ('P:'). - Update our 'W:' field to point to the webpage we have been building this year" * tag 'rust-6.7' of https://github.com/Rust-for-Linux/linux: docs: rust: add "The Rust experiment" section x86: Enable IBT in Rust if enabled in C rust: Use grep -Ev rather than relying on GNU grep rust: Use awk instead of recent xargs rust: upgrade to Rust 1.73.0 rust: print: use explicit link in documentation rust: task: remove redundant explicit link rust: kernel: remove `#[allow(clippy::new_ret_no_self)]` MAINTAINERS: add Maintainer Entry Profile field for Rust MAINTAINERS: update Rust webpage rust: upgrade to Rust 1.72.1 rust: arc: add explicit `drop()` around `Box::from_raw()`
2023-10-15rust: print: use explicit link in documentationMiguel Ojeda
The future `rustdoc` in the Rust 1.73.0 upgrade requires an explicit link for `pr_info!`: error: unresolved link to `pr_info` --> rust/kernel/print.rs:395:63 | 395 | /// Use only when continuing a previous `pr_*!` macro (e.g. [`pr_info!`]). | ^^^^^^^^ no item named `pr_info` in scope | = note: `macro_rules` named `pr_info` exists in this crate, but it is not in scope at this link's location = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings` Thus do so to avoid a broken link while upgrading. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20231005210556.466856-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-15rust: task: remove redundant explicit linkMiguel Ojeda
Starting with Rust 1.73.0, `rustdoc` detects redundant explicit links with its new lint `redundant_explicit_links` [1]: error: redundant explicit link target --> rust/kernel/task.rs:85:21 | 85 | /// [`current`](crate::current) macro because it is safe. | --------- ^^^^^^^^^^^^^^ explicit target is redundant | | | because label contains path that resolves to same destination | = note: when a link's destination is not specified, the label is used to resolve intra-doc links = note: `-D rustdoc::redundant-explicit-links` implied by `-D warnings` help: remove explicit link target | 85 | /// [`current`] macro because it is safe. In order to avoid the warning in the compiler upgrade commit, make it an intra-doc link as the tool suggests. Link: https://github.com/rust-lang/rust/pull/113167 [1] Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Link: https://lore.kernel.org/r/20231005210556.466856-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-12rust: error: Markdown style nitManmohan Shukla
This patch fixes a trivial markdown style nit in the `SAFETY` comment. Signed-off-by: Manmohan Shukla <manmshuk@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Jianguo Bao <roidinev@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Fixes: c7e20faa5fca ("rust: error: Add Error::to_ptr()") Link: https://lore.kernel.org/r/20230906204857.85619-1-manmshuk@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-12rust: error: fix the description for `ECHILD`Wedson Almeida Filho
A mistake was made and the description of `ECHILD` is wrong (it reuses the description of `ENOEXEC`). This fixes it to reflect what's in `errno-base.h`. Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Fixes: 266def2a0f5b ("rust: error: add codes from `errno-base.h`") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230930144958.46051-1-wedsonaf@gmail.com [ Use the plural, as noticed by Benno. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-05rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`Gary Guo
Clippy triggered a false positive on its `new_ret_no_self` lint when using the `pin_init!` macro. Since Rust 1.67.0, that does not happen anymore, since Clippy learnt to not warn about `-> impl Trait<Self>` [1][2]. The kernel nowadays uses Rust 1.72.1, thus remove the `#[allow]`. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://github.com/rust-lang/rust-clippy/issues/7344 [1] Link: https://github.com/rust-lang/rust-clippy/pull/9733 [2] Link: https://lore.kernel.org/r/20230923024707.47610-1-gary@garyguo.net [ Reworded slightly and added a couple `Link`s. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-05rust: arc: add explicit `drop()` around `Box::from_raw()`Miguel Ojeda
`Box::from_raw()` is `#[must_use]`, which means the result cannot go unused. In Rust 1.71.0, this was not detected because the block expression swallows the diagnostic [1]: unsafe { Box::from_raw(self.ptr.as_ptr()) }; It would have been detected, however, if the line had been instead: unsafe { Box::from_raw(self.ptr.as_ptr()); } i.e. the semicolon being inside the `unsafe` block, rather than outside. In Rust 1.72.0, the compiler started warning about this [2], so without this patch we will get: error: unused return value of `alloc::boxed::Box::<T>::from_raw` that must be used --> rust/kernel/sync/arc.rs:302:22 | 302 | unsafe { Box::from_raw(self.ptr.as_ptr()) }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box` = note: `-D unused-must-use` implied by `-D warnings` help: use `let _ = ...` to ignore the resulting value | 302 | unsafe { let _ = Box::from_raw(self.ptr.as_ptr()); }; | +++++++ + Thus add an add an explicit `drop()` as the `#[must_use]`'s annotation suggests (instead of the more general help line). Link: https://github.com/rust-lang/rust/issues/104253 [1] Link: https://github.com/rust-lang/rust/pull/112529 [2] Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Link: https://lore.kernel.org/r/20230823160244.188033-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-09-25rust: workqueue: add examplesAlice Ryhl
This adds two examples of how to use the workqueue. The first example shows how to use it when you only have one `work_struct` field, and the second example shows how to use it when you have multiple `work_struct` fields. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-25rust: workqueue: add `try_spawn` helper methodAlice Ryhl
This adds a convenience method that lets you spawn a closure for execution on a workqueue. This will be the most convenient way to use workqueues, but it is fallible because it needs to allocate memory. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-25rust: workqueue: implement `WorkItemPointer` for pointer typesAlice Ryhl
This implements the `WorkItemPointer` trait for the pointer types that you are likely to use the workqueue with. The `Arc` type is for reference counted objects, and the `Pin<Box<T>>` type is for objects where the caller has exclusive ownership of the object. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-25rust: workqueue: add helper for defining work_struct fieldsAlice Ryhl
The main challenge with defining `work_struct` fields is making sure that the function pointer stored in the `work_struct` is appropriate for the work item type it is embedded in. It needs to know the offset of the `work_struct` field being used (even if there are several!) so that it can do a `container_of`, and it needs to know the type of the work item so that it can call into the right user-provided code. All of this needs to happen in a way that provides a safe API to the user, so that users of the workqueue cannot mix up the function pointers. There are three important pieces that are relevant when doing this: * The pointer type. * The work item struct. This is what the pointer points at. * The `work_struct` field. This is a field of the work item struct. This patch introduces a separate trait for each piece. The pointer type is given a `WorkItemPointer` trait, which pointer types need to implement to be usable with the workqueue. This trait will be implemented for `Arc` and `Box` in a later patch in this patchset. Implementing this trait is unsafe because this is where the `container_of` operation happens, but user-code will not need to implement it themselves. The work item struct should then implement the `WorkItem` trait. This trait is where user-code specifies what they want to happen when a work item is executed. It also specifies what the correct pointer type is. Finally, to make the work item struct know the offset of its `work_struct` field, we use a trait called `HasWork<T, ID>`. If a type implements this trait, then the type declares that, at the given offset, there is a field of type `Work<T, ID>`. The trait is marked unsafe because the OFFSET constant must be correct, but we provide an `impl_has_work!` macro that can safely implement `HasWork<T>` on a type. The macro expands to something that only compiles if the specified field really has the type `Work<T>`. It is used like this: ``` struct MyWorkItem { work_field: Work<MyWorkItem, 1>, } impl_has_work! { impl HasWork<MyWorkItem, 1> for MyWorkItem { self.work_field } } ``` Note that since the `Work` type is annotated with an id, you can have several `work_struct` fields by using a different id for each one. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-25rust: workqueue: define built-in queuesWedson Almeida Filho
We provide these methods because it lets us access these queues from Rust without using unsafe code. These methods return `&'static Queue`. References annotated with the 'static lifetime are used when the referent will stay alive forever. That is ok for these queues because they are global variables and cannot be destroyed. Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Co-developed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-25rust: workqueue: add low-level workqueue bindingsAlice Ryhl
Define basic low-level bindings to a kernel workqueue. The API defined here can only be used unsafely. Later commits will provide safe wrappers. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-25rust: sync: add `Arc::{from_raw, into_raw}`Wedson Almeida Filho
These methods can be used to turn an `Arc` into a raw pointer and back, in a way that preserves the metadata for fat pointers. This is done using the unstable ptr_metadata feature [1]. However, it could also be done using the unstable pointer_byte_offsets feature [2], which is likely to have a shorter path to stabilization than ptr_metadata. Link: https://github.com/rust-lang/rust/issues/81513 [1] Link: https://github.com/rust-lang/rust/issues/96283 [2] Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Co-developed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>