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path: root/drivers/cpufreq/rcpufreq_dt.rs
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2025-10-21rust: driver: let probe() return impl PinInit<Self, Error>Danilo Krummrich
The driver model defines the lifetime of the private data stored in (and owned by) a bus device to be valid from when the driver is bound to a device (i.e. from successful probe()) until the driver is unbound from the device. This is already taken care of by the Rust implementation of the driver model. However, we still ask drivers to return a Result<Pin<KBox<Self>>> from probe(). Unlike in C, where we do not have the concept of initializers, but rather deal with uninitialized memory, drivers can just return an impl PinInit<Self, Error> instead. This contributes to more clarity to the fact that a driver returns it's device private data in probe() and the Rust driver model owns the data, manages the lifetime and - considering the lifetime - provides (safe) accessors for the driver. Hence, let probe() functions return an impl PinInit<Self, Error> instead of Result<Pin<KBox<Self>>>. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-01Merge tag 'cpufreq-arm-updates-6.18-rc' of ↵Rafael J. Wysocki
git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm Merge CPUFreq fixes for 6.18 from Viresh Kumar: "- Update frequency for all tegra CPUs (Aaron Kling). - Fix device leak in mediatek driver (Johan Hovold). - Rust cpufreq helper cleanup (Thorsten Blum)." * tag 'cpufreq-arm-updates-6.18-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm: cpufreq: tegra186: Initialize all cores to max frequencies cpufreq: tegra186: Set target frequency for all cpus in policy rust: cpufreq: streamline find_supply_names cpufreq: mediatek: fix device leak on probe failure
2025-10-01cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latencyRafael J. Wysocki
Commit a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us") caused platforms where cpuinfo.transition_latency is CPUFREQ_ETERNAL to get a very large transition latency whereas previously it had been capped at 10 ms (and later at 2 ms). This led to a user-observable regression between 6.6 and 6.12 as described by Shawn: "The dbs sampling_rate was 10000 us on 6.6 and suddently becomes 6442450 us (4294967295 / 1000 * 1.5) on 6.12 for these platforms because the default transition delay was dropped [...]. It slows down dbs governor's reacting to CPU loading change dramatically. Also, as transition_delay_us is used by schedutil governor as rate_limit_us, it shows a negative impact on device idle power consumption, because the device gets slightly less time in the lowest OPP." Evidently, the expectation of the drivers using CPUFREQ_ETERNAL as cpuinfo.transition_latency was that it would be capped by the core, but they may as well return a default transition latency value instead of CPUFREQ_ETERNAL and the core need not do anything with it. Accordingly, introduce CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS and make all of the drivers in question use it instead of CPUFREQ_ETERNAL. Also update the related Rust binding. Fixes: a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us") Closes: https://lore.kernel.org/linux-pm/20250922125929.453444-1-shawnguo2@yeah.net/ Reported-by: Shawn Guo <shawnguo@kernel.org> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 6.6+ <stable@vger.kernel.org> # 6.6+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/2264949.irdbgypaU6@rafael.j.wysocki [ rjw: Fix typo in new symbol name, drop redundant type cast from Rust binding ] Tested-by: Shawn Guo <shawnguo@kernel.org> # with cpufreq-dt driver Reviewed-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-29rust: cpufreq: streamline find_supply_namesThorsten Blum
Remove local variables from find_supply_names() and use .and_then() with the more concise kernel::kvec![] macro, instead of KVec::with_capacity() followed by .push() and Some(). No functional changes intended. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-08-03Merge tag 'rust-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness', 'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and 'ref_as_ptr' These are intended to avoid type casts with the 'as' operator, which are quite powerful, into restricted variants that are less powerful and thus should help to avoid mistakes - Remove the 'author' key now that most instances were moved to the plural one in the previous cycle 'kernel' crate: - New 'bug' module: add 'warn_on!' macro which reuses the existing 'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and kernel parameters: warn_on!(value == 42); To avoid duplicating the assembly code, the same strategy is followed as for the static branch code in order to share the assembly between both C and Rust This required a few rearrangements on C arch headers -- the existing C macros should still generate the same outputs, thus no functional change expected there - 'workqueue' module: add delayed work items, including a 'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an 'enqueue_delayed' method, e.g.: /// Enqueue the struct for execution on the system workqueue, /// where its value will be printed 42 jiffies later. fn print_later(value: Arc<MyStruct>) { let _ = workqueue::system().enqueue_delayed(value, 42); } - New 'bits' module: add support for 'bit' and 'genmask' functions, with runtime- and compile-time variants, e.g.: static_assert!(0b00010000 == bit_u8(4)); static_assert!(0b00011110 == genmask_u8(1..=4)); assert!(checked_bit_u32(u32::BITS).is_none()); - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which reads NUL-terminated strings from userspace into a '&CStr' Introduce 'UserPtr' newtype, similar in purpose to '__user' in C, to minimize mistakes handling userspace pointers, including mixing them up with integers and leaking them via the 'Debug' trait. Add it to the prelude, too - Start preparations for the replacement of our custom 'CStr' type with the analogous type in the 'core' standard library. This will take place across several cycles to make it easier. For this one, it includes a new 'fmt' module, using upstream method names and some other cleanups Replace 'fmt!' with a re-export, which helps Clippy lint properly, and clean up the found 'uninlined-format-args' instances - 'dma' module: - Clarify wording and be consistent in 'coherent' nomenclature - Convert the 'read!()' and 'write!()' macros to return a 'Result' - Add 'as_slice()', 'write()' methods in 'CoherentAllocation' - Expose 'count()' and 'size()' in 'CoherentAllocation' and add the corresponding type invariants - Implement 'CoherentAllocation::dma_handle_with_offset()' - 'time' module: - Make 'Instant' generic over clock source. This allows the compiler to assert that arithmetic expressions involving the 'Instant' use 'Instants' based on the same clock source - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers take a 'Duration' or an 'Instant' when setting the expiry time, depending on the timer mode. With this change, the compiler can check the type matches the timer mode - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep function that will select an appropriate sleep method depending on the requested sleep time - Avoid 64-bit divisions on 32-bit hardware when calculating timestamps - Seal the 'HrTimerMode' trait. This prevents users of the 'HrTimerMode' from implementing the trait on their own types - Pass the correct timer mode ID to 'hrtimer_start_range_ns()' - 'list' module: remove 'OFFSET' constants, allowing to remove pointer arithmetic; now 'impl_list_item!' invokes 'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other simplifications too - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a constant, which avoids exposing the type of the opaque pointer, and require 'into_foreign' to return non-null Remove the 'Either<L, R>' type as well. It is unused, and we want to encourage the use of custom enums for concrete use cases - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types to allow them to be used in generic APIs - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>'; and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>' - 'Opaque' type: add 'cast_from' method to perform a restricted cast that cannot change the inner type and use it in callers of 'container_of!'. Rename 'raw_get' to 'cast_into' to match it - 'rbtree' module: add 'is_empty' method - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and 'ARef', which are moved from the too general 'types' module which we want to reduce or eventually remove. Also fix a safety comment in 'static_lock_class' 'pin-init' crate: - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are now (pin-)initializers - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()' - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide it via 'Zeroable::zeroed()' - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for 'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for '"Rust"' and '"C"' ABIs and up to 20 arguments - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E> [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T' - Renamed 'zeroed()' to 'init_zeroed()' - Upstream dev news: improve CI more to deny warnings, use '--all-targets'. Check the synchronization status of the two '-next' branches in upstream and the kernel MAINTAINERS: - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo Stoakes as reviewers (thanks everyone) And a few other cleanups and improvements" * tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits) rust: Add warn_on macro arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust rust: kernel: move ARef and AlwaysRefCounted to sync::aref rust: sync: fix safety comment for `static_lock_class` rust: types: remove `Either<L, R>` rust: kernel: use `core::ffi::CStr` method names rust: str: add `CStr` methods matching `core::ffi::CStr` rust: str: remove unnecessary qualification rust: use `kernel::{fmt,prelude::fmt!}` rust: kernel: add `fmt` module rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args scripts: rust: emit path candidates in panic message scripts: rust: replace length checks with match rust: list: remove nonexistent generic parameter in link rust: bits: add support for bits/genmask macros rust: list: remove OFFSET constants rust: list: add `impl_list_item!` examples rust: list: use fully qualified path ...
2025-07-21rust: kernel: remove `fmt!`, fix clippy::uninlined-format-argsTamir Duberstein
Rather than export a macro that delegates to `core::format_args`, simply re-export `core::format_args` as `fmt` from the prelude. This exposes clippy warnings which were previously obscured by this macro, such as: warning: variables can be used directly in the `format!` string --> ../drivers/cpufreq/rcpufreq_dt.rs:21:43 | 21 | let prop_name = CString::try_from_fmt(fmt!("{}-supply", name)).ok()?; | ^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args = note: `-W clippy::uninlined-format-args` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::uninlined_format_args)]` help: change this to | 21 - let prop_name = CString::try_from_fmt(fmt!("{}-supply", name)).ok()?; 21 + let prop_name = CString::try_from_fmt(fmt!("{name}-supply")).ok()?; | Thus fix them in the same commit. This could possibly be fixed in two stages, but the diff is small enough (outside of kernel/str.rs) that I hope it can be taken in a single commit. Signed-off-by: Tamir Duberstein <tamird@gmail.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250704-core-cstr-prepare-v1-1-a91524037783@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-24rust: macros: remove `module!`'s deprecated `author` keyGuilherme Giacomo Simoes
Commit 38559da6afb2 ("rust: module: introduce `authors` key") introduced a new `authors` key to support multiple module authors, while keeping the old `author` key for backward compatibility. Now that most in-tree modules have migrated to `authors`, remove: 1. The deprecated `author` key support from the module macro 2. Legacy `author` entries from remaining modules Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com> Acked-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20250609122200.179307-1-trintaeoitogc@gmail.com [ Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-23Merge 6.16-rc3 into driver-core-nextGreg Kroah-Hartman
We need the driver-core fixes that are in 6.16-rc3 into here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-13rust: device: Move property_present() to FwNodeRemo Senekowitsch
The new FwNode abstraction will be used for accessing all device properties. It would be possible to duplicate the methods on the device itself, but since some of the methods on Device would have different type sigatures as the ones on FwNode, this would only lead to inconsistency and confusion. For this reason, property_present is removed from Device and existing users are updated. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Remo Senekowitsch <remo@buenzli.dev> Link: https://lore.kernel.org/r/20250611102908.212514-4-remo@buenzli.dev Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-12rust: Use CpuId in place of raw CPU numbersViresh Kumar
Use the newly defined `CpuId` abstraction instead of raw CPU numbers. This also fixes a doctest failure for configurations where `nr_cpu_ids < 4`. The C `cpumask_{set|clear}_cpu()` APIs emit a warning when given an invalid CPU number — but only if `CONFIG_DEBUG_PER_CPU_MAPS=y` is set. Meanwhile, `cpumask_weight()` only considers CPUs up to `nr_cpu_ids`, which can cause inconsistencies: a CPU number greater than `nr_cpu_ids` may be set in the mask, yet the weight calculation won't reflect it. This leads to doctest failures when `nr_cpu_ids < 4`, as the test tries to set CPUs 2 and 3: rust_doctest_kernel_cpumask_rs_0.location: rust/kernel/cpumask.rs:180 rust_doctest_kernel_cpumask_rs_0: ASSERTION FAILED at rust/kernel/cpumask.rs:190 Fixes: 8961b8cb3099 ("rust: cpumask: Add initial abstractions") Reported-by: Miguel Ojeda <ojeda@kernel.org> Closes: https://lore.kernel.org/rust-for-linux/CANiq72k3ozKkLMinTLQwvkyg9K=BeRxs1oYZSKhJHY-veEyZdg@mail.gmail.com/ Reported-by: Andreas Hindborg <a.hindborg@kernel.org> Closes: https://lore.kernel.org/all/87qzzy3ric.fsf@kernel.org/ Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
2025-05-20cpufreq: Add Rust-based cpufreq-dt driverViresh Kumar
Introduce a Rust-based implementation of the cpufreq-dt driver, covering most of the functionality provided by the existing C version. Some features, such as retrieving platform data from `cpufreq-dt-platdev.c`, are still pending. The driver has been tested with QEMU, and frequency scaling works as expected. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>