Commit Graph

20 Commits

Author SHA1 Message Date
Miguel Ojeda 32f072d9ea rust: cpufreq: fix formatting
We do our best to keep the repository `rustfmt`-clean, thus run the tool
to fix the formatting issue.

Link: https://docs.kernel.org/rust/coding-guidelines.html#style-formatting
Link: https://rust-for-linux.com/contributing#submit-checklist-addendum
Fixes: f97aef092e ("cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency")
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-17 00:56:20 +02:00
Rafael J. Wysocki 53d4d315d4 Merge branch 'pm-cpufreq'
Merge cpufreq fixes and cleanups, mostly on top of those fixes, for
6.18-rc1:

 - Make cpufreq drivers setting the default CPU transition latency to
   CPUFREQ_ETERNAL specify a proper default transition latency value
   instead which addresses a regression introduced during the 6.6 cycle
   that broke CPUFREQ_ETERNAL handling (Rafael Wysocki)

 - Make the cpufreq CPPC driver use a proper transition delay value
   when CPUFREQ_ETERNAL is returned by cppc_get_transition_latency() to
   indicate an error condition (Rafael Wysocki)

 - Make cppc_get_transition_latency() return a negative error code to
   indicate error conditions instead of using CPUFREQ_ETERNAL for this
   purpose and drop CPUFREQ_ETERNAL that has no other users (Rafael
   Wysocki, Gopi Krishna Menon)

 - Fix device leak in the mediatek cpufreq driver (Johan Hovold)

 - Set target frequency on all CPUs sharing a policy during frequency
   updates in the tegra186 cpufreq driver and make it initialize all
   cores to max frequencies (Aaron Kling)

 - Rust cpufreq helper cleanup (Thorsten Blum)

* pm-cpufreq:
  docs/zh_CN: Fix malformed table
  docs/zh_TW: Fix malformed table
  cpufreq: Drop unused symbol CPUFREQ_ETERNAL
  ACPI: CPPC: Do not use CPUFREQ_ETERNAL as an error value
  cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay
  cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency
  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
2025-10-07 12:31:46 +02:00
Linus Torvalds 991053178e Power management updates for 6.18-rc1
- Rearrange variable declarations involving __free() in the cpufreq
    core and intel_pstate driver to follow common coding style (Rafael
    Wysocki)
 
  - Fix object lifecycle issue in update_qos_request(), rearrange
    freq QoS updates using __free(), and adjust frequency percentage
    computations in the intel_pstate driver (Rafael Wysocki)
 
  - Update intel_pstate to allow it to enable HWP without EPP if the
    new DEC (Dynamic Efficiency Control) HW feature is enabled (Rafael
    Wysocki)
 
  - Use on_each_cpu_mask() in drv_write() in the ACPI cpufreq driver
    to simplify the code (Rafael Wysocki)
 
  - Use likely() optimization in intel_pstate_sample() (Yaxiong Tian)
 
  - Remove dead EPB-related code from intel_pstate (Srinivas Pandruvada)
 
  - Use scope-based cleanup for cpufreq policy references in multiple
    cpufreq drivers (Zihuan Zhang)
 
  - Avoid calling get_governor() for the first policy in the cpufreq core
    to simplify the initial policy path (Zihuan Zhang)
 
  - Clean up the cpufreq core in multiple places (Zihuan Zhang)
 
  - Use int type to store negative error codes in the cpufreq core and
    update the speedstep-lib to use int for error codes (Qianfeng Rong)
 
  - Update the efficient idle check for Intel extended Families in the
    ondemand cpufreq governor (Sohil Mehta)
 
  - Replace sscanf() with kstrtouint() in the conservative cpufreq
    governor (Kaushlendra Kumar)
 
  - Rename CpumaskVar::as[_mut]_ref to from_raw[_mut] in the cpumask
    Rust code and mark CpumaskVar as transparent (Alice Ryhl, Baptiste
    Lepers)
 
  - Update ARef and AlwaysRefCounted imports from sync::aref in the OPP
    Rust code (Shankari Anand)
 
  - Add support for AN7583 SoC to the airoha cpufreq driver (Christian
    Marangi)
 
  - Enable cpufreq for ipq5424 in the qcom-nvmem cpufreq driver (Md Sadre
    Alam)
 
  - Add support for MT8196 to the mediatek-hw cpufreq driver, refactor
    that driver and add mediatek,mt8196-cpufreq-hw DT binding (Nicolas
    Frattaroli)
 
  - Avoid redundant conditions in the mediatek cpufreq driver (Liao
    Yuanhong)
 
  - Add support for AM62D2 to the ti cpufreq driver and blocklist
    ti,am62d2 SoC in dt-platdev (Paresh Bhagat)
 
  - Support more speed grades on AM62Px SoC in the ti cpufreq driver,
    allow all silicon revisions to support OPPs in it, and fix supported
    hardware for 1GHz OPP (Judith Mendez)
 
  - Add QCS615 compatible to DT bindings for cpufreq-qcom-hw (Taniya Das)
 
  - Minor assorted updates of the scmi, longhaul, CPPC, and armada-37xx
    cpufreq drivers (Akhilesh Patil, BowenYu, Dennis Beier, and Florian
    Fainelli)
 
  - Remove outdated cpufreq-dt.txt (Frank Li)
 
  - Fix python gnuplot package names in the amd_pstate_tracer utility
    (Kuan-Wei Chiu)
 
  - Saravana Kannan will maintain the virtual-cpufreq driver (Saravana
    Kannan)
 
  - Prevent CPU capacity updates after registering a perf domain from
    failing on a first CPU that is not present (Christian Loehle)
 
  - Add support for the cases in which frequency alone is not sufficient
    to uniquely identify an OPP (Krishna Chaitanya Chundru)
 
  - Use to_result() for OPP error handling in Rust (Onur Özkan)
 
  - Add support for LPDDR5 on Rockhip RK3588 SoC to rockchip-dfi devfreq
    driver (Nicolas Frattaroli)
 
  - Fix an issue where DDR cycle counts on RK3588/RK3528 with LPDDR4(X)
    are reported as half by adding a cycle multiplier to the DFI driver
    in rockchip-dfi devfreq-event driver (Nicolas Frattaroli)
 
  - Fix missing error pointer dereference check of regulator instance in
    the mtk-cci devfreq driver probe and remove a redundant condition from
    an if () statement in that driver (Dan Carpenter, Liao Yuanhong)
 
  - Fail cpuidle device registration if there is one already to avoid
    sysfs-related issues (Rafael Wysocki)
 
  - Use sysfs_emit()/sysfs_emit_at() instead of sprintf()/scnprintf() in
    cpuidle (Vivek Yadav)
 
  - Fix device and OF node leaks at probe in the qcom-spm cpuidle driver
    and drop unnecessary initialisations from it (Johan Hovold)
 
  - Remove unnecessary address-of operators from the intel_idle cpuidle
    driver (Kaushlendra Kumar)
 
  - Rearrange main loop in menu_select() to make the code in that funtion
    easier to follow (Rafael Wysocki)
 
  - Convert values in microseconds to ktime using us_to_ktime() where
    applicable in the intel_idle power capping driver (Xichao Zhao)
 
  - Annotate loops walking device links in the power management core
    code as _srcu and add macros for walking device links to reduce the
    likelihood of coding mistakes related to them (Rafael Wysocki)
 
  - Document time units for *_time functions in the runtime PM API (Brian
    Norris)
 
  - Clear power.must_resume in noirq suspend error path to avoid resuming
    a dependant device under a suspended parent or supplier (Rafael
    Wysocki)
 
  - Fix GFP mask handling during hybrid suspend and make the amdgpu
    driver handle hybrid suspend correctly (Mario Limonciello, Rafael
    Wysocki)
 
  - Fix GFP mask handling after aborted hibernation in platform mode and
    combine exit paths in power_down() to avoid code duplication (Rafael
    Wysocki)
 
  - Use vmalloc_array() and vcalloc() in the hibernation core to avoid
    open-coded size computations (Qianfeng Rong)
 
  - Fix typo in hibernation core code comment (Li Jun)
 
  - Call pm_wakeup_clear() in the same place where other functions that do
    bookkeeping prior to suspend_prepare() are called (Samuel Wu)
 
  - Fix and clean up the x86_energy_perf_policy utility and update its
    documentation (Len Brown, Kaushlendra Kumar)
 
  - Fix incorrect sorting of PMT telemetry in turbostat (Kaushlendra
    Kumar)
 
  - Fix incorrect size in cpuidle_state_disable() and the error return
    value of cpupower_write_sysfs() in cpupower (Kaushlendra Kumar)
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Merge tag 'pm-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "The majority of these are cpufreq changes, which has been a recurring
  pattern for a few recent cycles.

  Those changes include new hardware support (AN7583 SoC support in the
  airoha cpufreq driver, ipq5424 support in the qcom-nvmem cpufreq
  driver, MT8196 support in the mediatek cpufreq driver, AM62D2 support
  in the ti cpufreq driver), DT bindings and Rust code updates, cleanups
  of the core and governors, and multiple driver fixes and cleanups.

  Beyond that, there are hibernation fixes (some remaining 6.16 cycle
  fallout and an issue related to hybrid suspend in the amdgpu driver),
  cleanups of the PM core code, runtime PM documentation update, cpuidle
  and power capping cleanups, and tooling updates.

  Specifics:

   - Rearrange variable declarations involving __free() in the cpufreq
     core and intel_pstate driver to follow common coding style (Rafael
     Wysocki)

   - Fix object lifecycle issue in update_qos_request(), rearrange freq
     QoS updates using __free(), and adjust frequency percentage
     computations in the intel_pstate driver (Rafael Wysocki)

   - Update intel_pstate to allow it to enable HWP without EPP if the
     new DEC (Dynamic Efficiency Control) HW feature is enabled (Rafael
     Wysocki)

   - Use on_each_cpu_mask() in drv_write() in the ACPI cpufreq driver to
     simplify the code (Rafael Wysocki)

   - Use likely() optimization in intel_pstate_sample() (Yaxiong Tian)

   - Remove dead EPB-related code from intel_pstate (Srinivas
     Pandruvada)

   - Use scope-based cleanup for cpufreq policy references in multiple
     cpufreq drivers (Zihuan Zhang)

   - Avoid calling get_governor() for the first policy in the cpufreq
     core to simplify the initial policy path (Zihuan Zhang)

   - Clean up the cpufreq core in multiple places (Zihuan Zhang)

   - Use int type to store negative error codes in the cpufreq core and
     update the speedstep-lib to use int for error codes (Qianfeng Rong)

   - Update the efficient idle check for Intel extended Families in the
     ondemand cpufreq governor (Sohil Mehta)

   - Replace sscanf() with kstrtouint() in the conservative cpufreq
     governor (Kaushlendra Kumar)

   - Rename CpumaskVar::as[_mut]_ref to from_raw[_mut] in the cpumask
     Rust code and mark CpumaskVar as transparent (Alice Ryhl, Baptiste
     Lepers)

   - Update ARef and AlwaysRefCounted imports from sync::aref in the OPP
     Rust code (Shankari Anand)

   - Add support for AN7583 SoC to the airoha cpufreq driver (Christian
     Marangi)

   - Enable cpufreq for ipq5424 in the qcom-nvmem cpufreq driver (Md
     Sadre Alam)

   - Add support for MT8196 to the mediatek-hw cpufreq driver, refactor
     that driver and add mediatek,mt8196-cpufreq-hw DT binding (Nicolas
     Frattaroli)

   - Avoid redundant conditions in the mediatek cpufreq driver (Liao
     Yuanhong)

   - Add support for AM62D2 to the ti cpufreq driver and blocklist
     ti,am62d2 SoC in dt-platdev (Paresh Bhagat)

   - Support more speed grades on AM62Px SoC in the ti cpufreq driver,
     allow all silicon revisions to support OPPs in it, and fix
     supported hardware for 1GHz OPP (Judith Mendez)

   - Add QCS615 compatible to DT bindings for cpufreq-qcom-hw (Taniya
     Das)

   - Minor assorted updates of the scmi, longhaul, CPPC, and armada-37xx
     cpufreq drivers (Akhilesh Patil, BowenYu, Dennis Beier, and Florian
     Fainelli)

   - Remove outdated cpufreq-dt.txt (Frank Li)

   - Fix python gnuplot package names in the amd_pstate_tracer utility
     (Kuan-Wei Chiu)

   - Saravana Kannan will maintain the virtual-cpufreq driver (Saravana
     Kannan)

   - Prevent CPU capacity updates after registering a perf domain from
     failing on a first CPU that is not present (Christian Loehle)

   - Add support for the cases in which frequency alone is not
     sufficient to uniquely identify an OPP (Krishna Chaitanya Chundru)

   - Use to_result() for OPP error handling in Rust (Onur Özkan)

   - Add support for LPDDR5 on Rockhip RK3588 SoC to rockchip-dfi
     devfreq driver (Nicolas Frattaroli)

   - Fix an issue where DDR cycle counts on RK3588/RK3528 with LPDDR4(X)
     are reported as half by adding a cycle multiplier to the DFI driver
     in rockchip-dfi devfreq-event driver (Nicolas Frattaroli)

   - Fix missing error pointer dereference check of regulator instance
     in the mtk-cci devfreq driver probe and remove a redundant
     condition from an if () statement in that driver (Dan Carpenter,
     Liao Yuanhong)

   - Fail cpuidle device registration if there is one already to avoid
     sysfs-related issues (Rafael Wysocki)

   - Use sysfs_emit()/sysfs_emit_at() instead of sprintf()/scnprintf()
     in cpuidle (Vivek Yadav)

   - Fix device and OF node leaks at probe in the qcom-spm cpuidle
     driver and drop unnecessary initialisations from it (Johan Hovold)

   - Remove unnecessary address-of operators from the intel_idle cpuidle
     driver (Kaushlendra Kumar)

   - Rearrange main loop in menu_select() to make the code in that
     funtion easier to follow (Rafael Wysocki)

   - Convert values in microseconds to ktime using us_to_ktime() where
     applicable in the intel_idle power capping driver (Xichao Zhao)

   - Annotate loops walking device links in the power management core
     code as _srcu and add macros for walking device links to reduce the
     likelihood of coding mistakes related to them (Rafael Wysocki)

   - Document time units for *_time functions in the runtime PM API
     (Brian Norris)

   - Clear power.must_resume in noirq suspend error path to avoid
     resuming a dependant device under a suspended parent or supplier
     (Rafael Wysocki)

   - Fix GFP mask handling during hybrid suspend and make the amdgpu
     driver handle hybrid suspend correctly (Mario Limonciello, Rafael
     Wysocki)

   - Fix GFP mask handling after aborted hibernation in platform mode
     and combine exit paths in power_down() to avoid code duplication
     (Rafael Wysocki)

   - Use vmalloc_array() and vcalloc() in the hibernation core to avoid
     open-coded size computations (Qianfeng Rong)

   - Fix typo in hibernation core code comment (Li Jun)

   - Call pm_wakeup_clear() in the same place where other functions that
     do bookkeeping prior to suspend_prepare() are called (Samuel Wu)

   - Fix and clean up the x86_energy_perf_policy utility and update its
     documentation (Len Brown, Kaushlendra Kumar)

   - Fix incorrect sorting of PMT telemetry in turbostat (Kaushlendra
     Kumar)

   - Fix incorrect size in cpuidle_state_disable() and the error return
     value of cpupower_write_sysfs() in cpupower (Kaushlendra Kumar)"

* tag 'pm-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (86 commits)
  PM: hibernate: Combine return paths in power_down()
  PM: hibernate: Restrict GFP mask in power_down()
  PM: hibernate: Fix pm_hibernation_mode_is_suspend() build breakage
  PM: runtime: Documentation: ABI: Document time units for *_time
  tools/power x86_energy_perf_policy.8: Emphasize preference for SW interfaces
  tools/power x86_energy_perf_policy: Add make snapshot target
  tools/power x86_energy_perf_policy: Prefer driver HWP limits
  tools/power x86_energy_perf_policy: EPB access is only via sysfs
  tools/power x86_energy_perf_policy: Prepare for MSR/sysfs refactoring
  tools/power x86_energy_perf_policy: Enhance HWP enable
  tools/power x86_energy_perf_policy: Enhance HWP enabled check
  tools/power x86_energy_perf_policy: Fix incorrect fopen mode usage
  tools/power turbostat: Fix incorrect sorting of PMT telemetry
  drm/amd: Fix hybrid sleep
  PM: hibernate: Add pm_hibernation_mode_is_suspend()
  PM: hibernate: Fix hybrid-sleep
  tools/cpupower: Fix incorrect size in cpuidle_state_disable()
  tools/power/x86/amd_pstate_tracer: Fix python gnuplot package names
  cpufreq: Replace pointer subtraction with iteration macro
  cpuidle: Fail cpuidle device registration if there is one already
  ...
2025-10-01 16:08:37 -07:00
Rafael J. Wysocki f97aef092e cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency
Commit a755d0e2d4 ("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: a755d0e2d4 ("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>
2025-10-01 13:56:24 +02:00
Tamir Duberstein 23cd58b1d8 rust: cpufreq: use `core::ffi::CStr` method names
Prepare for `core::ffi::CStr` taking the place of `kernel::str::CStr` by
avoid methods that only exist on the latter.

Link: https://github.com/Rust-for-Linux/linux/issues/1075
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-09-16 09:26:59 +02:00
Benno Lossin 4fa9f72d65 rust: cpufreq: replace `MaybeUninit::zeroed().assume_init()` with `pin_init::zeroed()`
All types in `bindings` implement `Zeroable` if they can, so use
`pin_init::zeroed` instead of relying on `unsafe` code.

If this ends up not compiling in the future, something in bindgen or on
the C side changed and is most likely incorrect.

Signed-off-by: Benno Lossin <lossin@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-09-08 14:03:29 +02:00
Alice Ryhl daad2ef991 rust: cpumask: rename CpumaskVar::as[_mut]_ref to from_raw[_mut]
The prefix as_* shouldn't be used for constructors. For further
motivation, see commit 2f5606afa4 ("device: rust: rename
Device::as_ref() to Device::from_raw()").

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-08-14 09:42:46 +05:30
Linus Torvalds 352af6a011 Rust changes for v6.17
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.
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Merge tag 'rust-6.17' of 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
  ...
2025-08-03 13:49:10 -07:00
Linus Torvalds 22c5696e3f Driver core changes for 6.17-rc1
- DEBUGFS
 
   - Remove unneeded debugfs_file_{get,put}() instances
 
   - Remove last remnants of debugfs_real_fops()
 
   - Allow storing non-const void * in struct debugfs_inode_info::aux
 
 - SYSFS
 
   - Switch back to attribute_group::bin_attrs (treewide)
 
   - Switch back to bin_attribute::read()/write() (treewide)
 
   - Constify internal references to 'struct bin_attribute'
 
 - Support cache-ids for device-tree systems
 
   - Add arch hook arch_compact_of_hwid()
 
   - Use arch_compact_of_hwid() to compact MPIDR values on arm64
 
 - Rust
 
   - Device
 
     - Introduce CoreInternal device context (for bus internal methods)
 
     - Provide generic drvdata accessors for bus devices
 
     - Provide Driver::unbind() callbacks
 
     - Use the infrastructure above for auxiliary, PCI and platform
 
     - Implement Device::as_bound()
 
     - Rename Device::as_ref() to Device::from_raw() (treewide)
 
     - Implement fwnode and device property abstractions
 
       - Implement example usage in the Rust platform sample driver
 
   - Devres
 
     - Remove the inner reference count (Arc) and use pin-init instead
 
     - Replace Devres::new_foreign_owned() with devres::register()
 
     - Require T to be Send in Devres<T>
 
     - Initialize the data kept inside a Devres last
 
     - Provide an accessor for the Devres associated Device
 
   - Device ID
 
     - Add support for ACPI device IDs and driver match tables
 
     - Split up generic device ID infrastructure
 
     - Use generic device ID infrastructure in net::phy
 
   - DMA
 
     - Implement the dma::Device trait
 
     - Add DMA mask accessors to dma::Device
 
     - Implement dma::Device for PCI and platform devices
 
     - Use DMA masks from the DMA sample module
 
   - I/O
 
     - Implement abstraction for resource regions (struct resource)
 
     - Implement resource-based ioremap() abstractions
 
     - Provide platform device accessors for I/O (remap) requests
 
   - Misc
 
     - Support fallible PinInit types in Revocable
 
     - Implement Wrapper<T> for Opaque<T>
 
     - Merge pin-init blanket dependencies (for Devres)
 
 - Misc
 
   - Fix OF node leak in auxiliary_device_create()
 
   - Use util macros in device property iterators
 
   - Improve kobject sample code
 
   - Add device_link_test() for testing device link flags
 
   - Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
 
   - Hint to prefer container_of_const() over container_of()
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Merge tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

Pull driver core updates from Danilo Krummrich:
 "debugfs:
   - Remove unneeded debugfs_file_{get,put}() instances
   - Remove last remnants of debugfs_real_fops()
   - Allow storing non-const void * in struct debugfs_inode_info::aux

  sysfs:
   - Switch back to attribute_group::bin_attrs (treewide)
   - Switch back to bin_attribute::read()/write() (treewide)
   - Constify internal references to 'struct bin_attribute'

  Support cache-ids for device-tree systems:
   - Add arch hook arch_compact_of_hwid()
   - Use arch_compact_of_hwid() to compact MPIDR values on arm64

  Rust:
   - Device:
       - Introduce CoreInternal device context (for bus internal methods)
       - Provide generic drvdata accessors for bus devices
       - Provide Driver::unbind() callbacks
       - Use the infrastructure above for auxiliary, PCI and platform
       - Implement Device::as_bound()
       - Rename Device::as_ref() to Device::from_raw() (treewide)
       - Implement fwnode and device property abstractions
       - Implement example usage in the Rust platform sample driver
   - Devres:
       - Remove the inner reference count (Arc) and use pin-init instead
       - Replace Devres::new_foreign_owned() with devres::register()
       - Require T to be Send in Devres<T>
       - Initialize the data kept inside a Devres last
       - Provide an accessor for the Devres associated Device
   - Device ID:
       - Add support for ACPI device IDs and driver match tables
       - Split up generic device ID infrastructure
       - Use generic device ID infrastructure in net::phy
   - DMA:
       - Implement the dma::Device trait
       - Add DMA mask accessors to dma::Device
       - Implement dma::Device for PCI and platform devices
       - Use DMA masks from the DMA sample module
   - I/O:
       - Implement abstraction for resource regions (struct resource)
       - Implement resource-based ioremap() abstractions
       - Provide platform device accessors for I/O (remap) requests
   - Misc:
       - Support fallible PinInit types in Revocable
       - Implement Wrapper<T> for Opaque<T>
       - Merge pin-init blanket dependencies (for Devres)

  Misc:
   - Fix OF node leak in auxiliary_device_create()
   - Use util macros in device property iterators
   - Improve kobject sample code
   - Add device_link_test() for testing device link flags
   - Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
   - Hint to prefer container_of_const() over container_of()"

* tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (84 commits)
  rust: io: fix broken intra-doc links to `platform::Device`
  rust: io: fix broken intra-doc link to missing `flags` module
  rust: io: mem: enable IoRequest doc-tests
  rust: platform: add resource accessors
  rust: io: mem: add a generic iomem abstraction
  rust: io: add resource abstraction
  rust: samples: dma: set DMA mask
  rust: platform: implement the `dma::Device` trait
  rust: pci: implement the `dma::Device` trait
  rust: dma: add DMA addressing capabilities
  rust: dma: implement `dma::Device` trait
  rust: net::phy Change module_phy_driver macro to use module_device_table macro
  rust: net::phy represent DeviceId as transparent wrapper over mdio_device_id
  rust: device_id: split out index support into a separate trait
  device: rust: rename Device::as_ref() to Device::from_raw()
  arm64: cacheinfo: Provide helper to compress MPIDR value into u32
  cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id
  cacheinfo: Set cache 'id' based on DT data
  container_of: Document container_of() is not to be used in new code
  driver core: auxiliary bus: fix OF node leak
  ...
2025-07-29 12:15:39 -07:00
Danilo Krummrich 46ae8fd738 rust: devres: replace Devres::new_foreign_owned()
Replace Devres::new_foreign_owned() with devres::register().

The current implementation of Devres::new_foreign_owned() creates a full
Devres container instance, including the internal Revocable and
completion.

However, none of that is necessary for the intended use of giving full
ownership of an object to devres and getting it dropped once the given
device is unbound.

Hence, implement devres::register(), which is limited to consume the
given data, wrap it in a KBox and drop the KBox once the given device is
unbound, without any other synchronization.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250626200054.243480-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-28 18:06:53 +02:00
Viresh Kumar b6985083be rust: Use consistent "# Examples" heading style in rustdoc
Use a consistent `# Examples` heading in rustdoc across the codebase.

Some modules previously used `## Examples` (even when they should be
available as top-level headers), while others used `# Example`, which
deviates from the preferred `# Examples` style.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/ddd5ce0ac20c99a72a4f1e4322d3de3911056922.1749545815.git.viresh.kumar@linaro.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-24 01:02:30 +02:00
Abhinav Ananthu b0a86fb0b2 rust: cpufreq: use c_ types from kernel prelude
Update cpufreq FFI callback signatures to use `c_int` from the `kernel::prelude`,
rather than accessing it explicitly through `kernel::ffi::c_int`.

Although these types are defined in the `ffi` crate, they are re-exported
via `kernel::prelude`. This aligns with the Rust-for-Linux coding
guidelines and ensures proper C ABI compatibility across platforms.

Signed-off-by: Abhinav Ananthu <abhinav.ogl@gmail.com>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
[ Viresh: Fixed rustfmtcheck errors ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-06-23 09:45:45 +05:30
Tamir Duberstein fcad9bbf9e rust: enable `clippy::ptr_as_ptr` lint
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>
2025-06-22 23:08:42 +02:00
Abhinav Ananthu 10bb7f09e3 rust: cpufreq: Ensure C ABI compatibility in all unsafe
Update all `unsafe extern "C"` callback functions in the cpufreq module to
use `kernel::ffi` types (`c_int`, `c_uint`, etc.) instead of Rust-native
types like `i32`, `u32`, or `usize`.

This change ensures that all Rust callbacks have signatures that are
ABI-compatible with their corresponding C counterparts, which is critical
for FFI correctness and safety.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1170
Signed-off-by: Abhinav Ananthu <abhinav.ogl@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-06-19 13:25:46 +05:30
Viresh Kumar 33db8c97b4 rust: Use CpuId in place of raw CPU numbers
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: 8961b8cb30 ("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>
2025-06-12 10:31:28 +05:30
Viresh Kumar 4823a58093 cpufreq: Convert `/// SAFETY` lines to `# Safety` sections
Replace `/// SAFETY` comments in doc comments with proper `# Safety`
sections, as per rustdoc conventions.

Also mark the C FFI callbacks as `unsafe` to correctly reflect their
safety requirements.

Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://github.com/Rust-for-Linux/linux/issues/1169
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-06-10 16:38:56 +05:30
Linus Torvalds ec7714e494 Rust changes for v6.16
Toolchain and infrastructure:
 
  - KUnit '#[test]'s:
 
    - Support KUnit-mapped 'assert!' macros.
 
      The support that landed last cycle was very basic, and the
      'assert!' macros panicked since they were the standard library
      ones. Now, they are mapped to the KUnit ones in a similar way to
      how is done for doctests, reusing the infrastructure there.
 
      With this, a failing test like:
 
          #[test]
          fn my_first_test() {
              assert_eq!(42, 43);
          }
 
      will report:
 
          # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
          Expected 42 == 43 to be true, but is false
          # my_first_test.speed: normal
          not ok 1 my_first_test
 
    - Support tests with checked 'Result' return types.
 
      The return value of test functions that return a 'Result' will be
      checked, thus one can now easily catch errors when e.g. using the
      '?' operator in tests.
 
      With this, a failing test like:
 
          #[test]
          fn my_test() -> Result {
              f()?;
              Ok(())
          }
 
      will report:
 
          # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321
          Expected is_test_result_ok(my_test()) to be true, but is false
          # my_test.speed: normal
          not ok 1 my_test
 
    - Add 'kunit_tests' to the prelude.
 
  - Clarify the remaining language unstable features in use.
 
  - Compile 'core' with edition 2024 for Rust >= 1.87.
 
  - Workaround 'bindgen' issue with forward references to 'enum' types.
 
  - objtool: relax slice condition to cover more 'noreturn' functions.
 
  - Use absolute paths in macros referencing 'core' and 'kernel' crates.
 
  - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds.
 
  - Clean some 'doc_markdown' lint hits -- we may enable it later on.
 
 'kernel' crate:
 
  - 'alloc' module:
 
    - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>' if
      'T' implements 'U'.
 
    - 'Vec': implement new methods (prerequisites for nova-core and
      binder): 'truncate', 'resize', 'clear', 'pop',
      'push_within_capacity' (with new error type 'PushError'),
      'drain_all', 'retain', 'remove' (with new error type
      'RemoveError'), insert_within_capacity' (with new error type
      'InsertError').
 
      In addition, simplify 'push' using 'spare_capacity_mut', split
      'set_len' into 'inc_len' and 'dec_len', add type invariant
      'len <= capacity' and simplify 'truncate' using 'dec_len'.
 
  - 'time' module:
 
    - Morph the Rust hrtimer subsystem into the Rust timekeeping
      subsystem, covering delay, sleep, timekeeping, timers. This new
      subsystem has all the relevant timekeeping C maintainers listed in
      the entry.
 
    - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a
      duration of time and a point in time.
 
    - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer' to
      delay converting to 'Instant' and 'Delta'.
 
  - 'xarray' module:
 
    - Add a Rust abstraction for the 'xarray' data structure. This
      abstraction allows Rust code to leverage the 'xarray' to store
      types that implement 'ForeignOwnable'. This support is a dependency
      for memory backing feature of the Rust null block driver, which is
      waiting to be merged.
 
    - Set up an entry in 'MAINTAINERS' for the XArray Rust support.
      Patches will go to the new Rust XArray tree and then via the Rust
      subsystem tree for now.
 
    - Allow 'ForeignOwnable' to carry information about the pointed-to
      type. This helps asserting alignment requirements for the pointer
      passed to the foreign language.
 
  - 'container_of!': retain pointer mut-ness and add a compile-time check
    of the type of the first parameter ('$field_ptr').
 
  - Support optional message in 'static_assert!'.
 
  - Add C FFI types (e.g. 'c_int') to the prelude.
 
  - 'str' module: simplify KUnit tests 'format!' macro, convert
    'rusttest' tests into KUnit, take advantage of the '-> Result'
    support in KUnit '#[test]'s.
 
  - 'list' module: add examples for 'List', fix path of 'assert_pinned!'
    (so far unused macro rule).
 
  - 'workqueue' module: remove 'HasWork::OFFSET'.
 
  - 'page' module: add 'inline' attribute.
 
 'macros' crate:
 
  - 'module' macro: place 'cleanup_module()' in '.exit.text' section.
 
 'pin-init' crate:
 
  - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper
    structs with a structurally pinned value such as 'UnsafeCell<T>' or
    'MaybeUninit<T>'.
 
  - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but
    not error if not all fields implement it. This is needed to derive
    'Zeroable' for all bindgen-generated structs.
 
  - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the
    initialized type of an initializer. These are utilized by the
    'Wrapper<T>' implementations.
 
  - Add support for visibility in 'Zeroable' derive macro.
 
  - Add support for 'union's in 'Zeroable' derive macro.
 
  - Upstream dev news: streamline CI, fix some bugs. Add new workflows
    to check if the user-space version and the one in the kernel tree
    have diverged. Use the issues tab [1] to track them, which should
    help folks report and diagnose issues w.r.t. 'pin-init' better.
 
      [1] https://github.com/rust-for-linux/pin-init/issues
 
 Documentation:
 
  - Testing: add docs on the new KUnit '#[test]' tests.
 
  - Coding guidelines: explain that '///' vs. '//' applies to private
    items too. Add section on C FFI types.
 
  - Quick Start guide: update Ubuntu instructions and split them into
    "25.04" and "24.04 LTS and older".
 
 And a few other cleanups and improvements.
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Merge tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - KUnit '#[test]'s:

      - Support KUnit-mapped 'assert!' macros.

        The support that landed last cycle was very basic, and the
        'assert!' macros panicked since they were the standard library
        ones. Now, they are mapped to the KUnit ones in a similar way to
        how is done for doctests, reusing the infrastructure there.

        With this, a failing test like:

            #[test]
            fn my_first_test() {
                assert_eq!(42, 43);
            }

        will report:

            # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
            Expected 42 == 43 to be true, but is false
            # my_first_test.speed: normal
            not ok 1 my_first_test

      - Support tests with checked 'Result' return types.

        The return value of test functions that return a 'Result' will
        be checked, thus one can now easily catch errors when e.g. using
        the '?' operator in tests.

        With this, a failing test like:

            #[test]
            fn my_test() -> Result {
                f()?;
                Ok(())
            }

        will report:

            # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321
            Expected is_test_result_ok(my_test()) to be true, but is false
            # my_test.speed: normal
            not ok 1 my_test

      - Add 'kunit_tests' to the prelude.

   - Clarify the remaining language unstable features in use.

   - Compile 'core' with edition 2024 for Rust >= 1.87.

   - Workaround 'bindgen' issue with forward references to 'enum' types.

   - objtool: relax slice condition to cover more 'noreturn' functions.

   - Use absolute paths in macros referencing 'core' and 'kernel'
     crates.

   - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds.

   - Clean some 'doc_markdown' lint hits -- we may enable it later on.

  'kernel' crate:

   - 'alloc' module:

      - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>'
        if 'T' implements 'U'.

      - 'Vec': implement new methods (prerequisites for nova-core and
        binder): 'truncate', 'resize', 'clear', 'pop',
        'push_within_capacity' (with new error type 'PushError'),
        'drain_all', 'retain', 'remove' (with new error type
        'RemoveError'), insert_within_capacity' (with new error type
        'InsertError').

        In addition, simplify 'push' using 'spare_capacity_mut', split
        'set_len' into 'inc_len' and 'dec_len', add type invariant 'len
        <= capacity' and simplify 'truncate' using 'dec_len'.

   - 'time' module:

      - Morph the Rust hrtimer subsystem into the Rust timekeeping
        subsystem, covering delay, sleep, timekeeping, timers. This new
        subsystem has all the relevant timekeeping C maintainers listed
        in the entry.

      - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a
        duration of time and a point in time.

      - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer'
        to delay converting to 'Instant' and 'Delta'.

   - 'xarray' module:

      - Add a Rust abstraction for the 'xarray' data structure. This
        abstraction allows Rust code to leverage the 'xarray' to store
        types that implement 'ForeignOwnable'. This support is a
        dependency for memory backing feature of the Rust null block
        driver, which is waiting to be merged.

      - Set up an entry in 'MAINTAINERS' for the XArray Rust support.
        Patches will go to the new Rust XArray tree and then via the
        Rust subsystem tree for now.

      - Allow 'ForeignOwnable' to carry information about the pointed-to
        type. This helps asserting alignment requirements for the
        pointer passed to the foreign language.

   - 'container_of!': retain pointer mut-ness and add a compile-time
     check of the type of the first parameter ('$field_ptr').

   - Support optional message in 'static_assert!'.

   - Add C FFI types (e.g. 'c_int') to the prelude.

   - 'str' module: simplify KUnit tests 'format!' macro, convert
     'rusttest' tests into KUnit, take advantage of the '-> Result'
     support in KUnit '#[test]'s.

   - 'list' module: add examples for 'List', fix path of
     'assert_pinned!' (so far unused macro rule).

   - 'workqueue' module: remove 'HasWork::OFFSET'.

   - 'page' module: add 'inline' attribute.

  'macros' crate:

   - 'module' macro: place 'cleanup_module()' in '.exit.text' section.

  'pin-init' crate:

   - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper
     structs with a structurally pinned value such as 'UnsafeCell<T>' or
     'MaybeUninit<T>'.

   - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but
     not error if not all fields implement it. This is needed to derive
     'Zeroable' for all bindgen-generated structs.

   - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the
     initialized type of an initializer. These are utilized by the
     'Wrapper<T>' implementations.

   - Add support for visibility in 'Zeroable' derive macro.

   - Add support for 'union's in 'Zeroable' derive macro.

   - Upstream dev news: streamline CI, fix some bugs. Add new workflows
     to check if the user-space version and the one in the kernel tree
     have diverged. Use the issues tab [1] to track them, which should
     help folks report and diagnose issues w.r.t. 'pin-init' better.

       [1] https://github.com/rust-for-linux/pin-init/issues

  Documentation:

   - Testing: add docs on the new KUnit '#[test]' tests.

   - Coding guidelines: explain that '///' vs. '//' applies to private
     items too. Add section on C FFI types.

   - Quick Start guide: update Ubuntu instructions and split them into
     "25.04" and "24.04 LTS and older".

  And a few other cleanups and improvements"

* tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (78 commits)
  rust: list: Fix typo `much` in arc.rs
  rust: check type of `$ptr` in `container_of!`
  rust: workqueue: remove HasWork::OFFSET
  rust: retain pointer mut-ness in `container_of!`
  Documentation: rust: testing: add docs on the new KUnit `#[test]` tests
  Documentation: rust: rename `#[test]`s to "`rusttest` host tests"
  rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s
  rust: str: simplify KUnit tests `format!` macro
  rust: str: convert `rusttest` tests into KUnit
  rust: add `kunit_tests` to the prelude
  rust: kunit: support checked `-> Result`s in KUnit `#[test]`s
  rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s
  rust: make section names plural
  rust: list: fix path of `assert_pinned!`
  rust: compile libcore with edition 2024 for 1.87+
  rust: dma: add missing Markdown code span
  rust: task: add missing Markdown code spans and intra-doc links
  rust: pci: fix docs related to missing Markdown code spans
  rust: alloc: add missing Markdown code span
  rust: alloc: add missing Markdown code spans
  ...
2025-06-04 21:18:37 -07:00
Viresh Kumar c6af9a1191 rust: cpufreq: Extend abstractions for driver registration
Extend the cpufreq abstractions to support driver registration from
Rust.

Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 11:21:10 +05:30
Viresh Kumar 6ebdd7c931 rust: cpufreq: Extend abstractions for policy and driver ops
Extend the cpufreq abstractions to include support for policy handling
and driver operations.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 11:21:10 +05:30
Viresh Kumar 2207856ff0 rust: cpufreq: Add initial abstractions for cpufreq framework
Introduce initial Rust abstractions for the cpufreq core. This includes
basic representations for cpufreq flags, relation types, and the cpufreq
table.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 11:21:10 +05:30