Commit Graph

18 Commits

Author SHA1 Message Date
Linus Torvalds 784faa8eca Rust changes for v6.19
Toolchain and infrastructure:
 
  - Add support for 'syn'.
 
      Syn is a parsing library for parsing a stream of Rust tokens into a
      syntax tree of Rust source code.
 
      Currently this library is geared toward use in Rust procedural
      macros, but contains some APIs that may be useful more generally.
 
    'syn' allows us to greatly simplify writing complex macros such as
    'pin-init' (Benno has already prepared the 'syn'-based version). We
    will use it in the 'macros' crate too.
 
    'syn' is the most downloaded Rust crate (according to crates.io), and
    it is also used by the Rust compiler itself. While the amount of code
    is substantial, there should not be many updates needed for these
    crates, and even if there are, they should not be too big, e.g. +7k
    -3k lines across the 3 crates in the last year.
 
    'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
    I only modified their code to remove a third dependency
    ('unicode-ident') and to add the SPDX identifiers. The code can be
    easily verified to exactly match upstream with the provided scripts.
 
    They are all licensed under "Apache-2.0 OR MIT", like the other
    vendored 'alloc' crate we had for a while.
 
    Please see the merge commit with the cover letter for more context.
 
  - Allow 'unreachable_pub' and 'clippy::disallowed_names' for doctests.
 
    Examples (i.e. doctests) may want to do things like show public items
    and use names such as 'foo'.
 
    Nevertheless, we still try to keep examples as close to real code as
    possible (this is part of why running Clippy on doctests is important
    for us, e.g. for safety comments, which userspace Rust does not
    support yet but we are stricter).
 
 'kernel' crate:
 
  - Replace our custom 'CStr' type with 'core::ffi::CStr'.
 
    Using the standard library type reduces our custom code footprint,
    and we retain needed custom functionality through an extension trait
    and a new 'fmt!' macro which replaces the previous 'core' import.
 
    This started in 6.17 and continued in 6.18, and we finally land the
    replacement now. This required quite some stamina from Tamir, who
    split the changes in steps to prepare for the flag day change here.
 
  - Replace 'kernel::c_str!' with C string literals.
 
    C string literals were added in Rust 1.77, which produce '&CStr's
    (the 'core' one), so now we can write:
 
        c"hi"
 
    instead of:
 
        c_str!("hi")
 
  - Add 'num' module for numerical features.
 
    It includes the 'Integer' trait, implemented for all primitive
    integer types.
 
    It also includes the 'Bounded' integer wrapping type: an integer
    value that requires only the 'N' less significant bits of the wrapped
    type to be encoded:
 
        // An unsigned 8-bit integer, of which only the 4 LSBs are used.
        let v = Bounded::<u8, 4>:🆕:<15>();
        assert_eq!(v.get(), 15);
 
    'Bounded' is useful to e.g. enforce guarantees when working with
    bitfields that have an arbitrary number of bits.
 
    Values can be constructed from simple non-constant expressions or,
    for more complex ones, validated at runtime.
 
    'Bounded' also comes with comparison and arithmetic operations (with
    both their backing type and other 'Bounded's with a compatible
    backing type), casts to change the backing type, extending/shrinking
    and infallible/fallible conversions from/to primitives as applicable.
 
  - 'rbtree' module: add immutable cursor ('Cursor').
 
    It enables to use just an immutable tree reference where appropriate.
    The existing fully-featured mutable cursor is renamed to 'CursorMut'.
 
 kallsyms:
 
  - Fix wrong "big" kernel symbol type read from procfs.
 
 'pin-init' crate:
 
  - A couple minor fixes (Benno asked me to pick these patches up for
    him this cycle).
 
 Documentation:
 
  - Quick Start guide: add Debian 13 (Trixie).
 
    Debian Stable is now able to build Linux, since Debian 13 (released
    2025-08-09) packages Rust 1.85.0, which is recent enough.
 
    We are planning to propose that the minimum supported Rust version in
    Linux follows Debian Stable releases, with Debian 13 being the first
    one we upgrade to, i.e. Rust 1.85.
 
 MAINTAINERS:
 
  - Add entry for the new 'num' module.
 
  - Remove Alex as Rust maintainer: he hasn't had the time to contribute
    for a few years now, so it is a no-op change in practice.
 
 And a few other cleanups and improvements.
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Merge tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

   - Add support for 'syn'.

     Syn is a parsing library for parsing a stream of Rust tokens into a
     syntax tree of Rust source code.

     Currently this library is geared toward use in Rust procedural
     macros, but contains some APIs that may be useful more generally.

     'syn' allows us to greatly simplify writing complex macros such as
     'pin-init' (Benno has already prepared the 'syn'-based version). We
     will use it in the 'macros' crate too.

     'syn' is the most downloaded Rust crate (according to crates.io),
     and it is also used by the Rust compiler itself. While the amount
     of code is substantial, there should not be many updates needed for
     these crates, and even if there are, they should not be too big,
     e.g. +7k -3k lines across the 3 crates in the last year.

     'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
     I only modified their code to remove a third dependency
     ('unicode-ident') and to add the SPDX identifiers. The code can be
     easily verified to exactly match upstream with the provided
     scripts.

     They are all licensed under "Apache-2.0 OR MIT", like the other
     vendored 'alloc' crate we had for a while.

     Please see the merge commit with the cover letter for more context.

   - Allow 'unreachable_pub' and 'clippy::disallowed_names' for
     doctests.

     Examples (i.e. doctests) may want to do things like show public
     items and use names such as 'foo'.

     Nevertheless, we still try to keep examples as close to real code
     as possible (this is part of why running Clippy on doctests is
     important for us, e.g. for safety comments, which userspace Rust
     does not support yet but we are stricter).

  'kernel' crate:

   - Replace our custom 'CStr' type with 'core::ffi::CStr'.

     Using the standard library type reduces our custom code footprint,
     and we retain needed custom functionality through an extension
     trait and a new 'fmt!' macro which replaces the previous 'core'
     import.

     This started in 6.17 and continued in 6.18, and we finally land the
     replacement now. This required quite some stamina from Tamir, who
     split the changes in steps to prepare for the flag day change here.

   - Replace 'kernel::c_str!' with C string literals.

     C string literals were added in Rust 1.77, which produce '&CStr's
     (the 'core' one), so now we can write:

         c"hi"

     instead of:

         c_str!("hi")

   - Add 'num' module for numerical features.

     It includes the 'Integer' trait, implemented for all primitive
     integer types.

     It also includes the 'Bounded' integer wrapping type: an integer
     value that requires only the 'N' least significant bits of the
     wrapped type to be encoded:

         // An unsigned 8-bit integer, of which only the 4 LSBs are used.
         let v = Bounded::<u8, 4>:🆕:<15>();
         assert_eq!(v.get(), 15);

     'Bounded' is useful to e.g. enforce guarantees when working with
     bitfields that have an arbitrary number of bits.

     Values can also be constructed from simple non-constant expressions
     or, for more complex ones, validated at runtime.

     'Bounded' also comes with comparison and arithmetic operations
     (with both their backing type and other 'Bounded's with a
     compatible backing type), casts to change the backing type,
     extending/shrinking and infallible/fallible conversions from/to
     primitives as applicable.

   - 'rbtree' module: add immutable cursor ('Cursor').

     It enables to use just an immutable tree reference where
     appropriate. The existing fully-featured mutable cursor is renamed
     to 'CursorMut'.

  kallsyms:

   - Fix wrong "big" kernel symbol type read from procfs.

  'pin-init' crate:

   - A couple minor fixes (Benno asked me to pick these patches up for
     him this cycle).

  Documentation:

   - Quick Start guide: add Debian 13 (Trixie).

     Debian Stable is now able to build Linux, since Debian 13 (released
     2025-08-09) packages Rust 1.85.0, which is recent enough.

     We are planning to propose that the minimum supported Rust version
     in Linux follows Debian Stable releases, with Debian 13 being the
     first one we upgrade to, i.e. Rust 1.85.

  MAINTAINERS:

   - Add entry for the new 'num' module.

   - Remove Alex as Rust maintainer: he hasn't had the time to
     contribute for a few years now, so it is a no-op change in
     practice.

  And a few other cleanups and improvements"

* tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
  rust: macros: support `proc-macro2`, `quote` and `syn`
  rust: syn: enable support in kbuild
  rust: syn: add `README.md`
  rust: syn: remove `unicode-ident` dependency
  rust: syn: add SPDX License Identifiers
  rust: syn: import crate
  rust: quote: enable support in kbuild
  rust: quote: add `README.md`
  rust: quote: add SPDX License Identifiers
  rust: quote: import crate
  rust: proc-macro2: enable support in kbuild
  rust: proc-macro2: add `README.md`
  rust: proc-macro2: remove `unicode_ident` dependency
  rust: proc-macro2: add SPDX License Identifiers
  rust: proc-macro2: import crate
  rust: kbuild: support using libraries in `rustc_procmacro`
  rust: kbuild: support skipping flags in `rustc_test_library`
  rust: kbuild: add proc macro library support
  rust: kbuild: simplify `--cfg` handling
  rust: kbuild: introduce `core-flags` and `core-skip_flags`
  ...
2025-12-03 14:16:49 -08:00
Tamir Duberstein 33ffb0aa8c rust: opp: simplify callers of `to_c_str_array`
Use `Option` combinators to make this a bit less noisy.

Wrap the `dev_pm_opp_set_config` operation in a closure and use type
ascription to leverage the compiler to check for use after free.

Signed-off-by: Tamir Duberstein <tamird@kernel.org>
Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-10-23 20:51:17 +05:30
Tamir Duberstein 965a39a962 rust: opp: use `CStr::as_char_ptr`
Replace the use of `as_ptr` which works through `<CStr as
Deref<Target=&[u8]>::deref()` in preparation for replacing
`kernel::str::CStr` with `core::ffi::CStr` as the latter does not
implement `Deref<Target=&[u8]>`.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20251018-cstr-core-v18-10-9378a54385f8@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-22 07:14:47 +02:00
Tamir Duberstein e6fdbe8fea rust: opp: fix broken rustdoc link
Correct the spelling of "CString" to make the link work.

Fixes: ce32e2d47c ("rust: opp: Add abstractions for the configuration options")
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-10-22 09:26:20 +05:30
Rafael J. Wysocki d6fd599cd4 Merge branches 'pm-em', 'pm-opp' and 'pm-devfreq'
Merge energy model management, OPP (operating performance points) and
devfreq updates for 6.18-rc1:

 - 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)

* pm-em:
  PM: EM: Fix late boot with holes in CPU topology

* pm-opp:
  OPP: Add support to find OPP for a set of keys
  rust: opp: use to_result for error handling

* pm-devfreq:
  PM / devfreq: rockchip-dfi: add support for LPDDR5
  PM / devfreq: rockchip-dfi: double count on RK3588
  PM / devfreq: mtk-cci: avoid redundant conditions
  PM / devfreq: mtk-cci: Fix potential error pointer dereference in probe()
2025-09-29 12:30:44 +02:00
Onur Özkan 22763c35c6 rust: opp: use to_result for error handling
Simplifies error handling by replacing the manual check
of the return value with the `to_result` helper.

Signed-off-by: Onur Özkan <work@onurozkan.dev>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-08-26 10:40:45 +05:30
Shankari Anand e88ef67762 rust: opp: update ARef and AlwaysRefCounted imports from sync::aref
Update call sites in `opp.rs` to import ARef and
AlwaysRefCounted from sync::aref instead of types.

This aligns with the ongoing effort to move ARef and
AlwaysRefCounted to sync.

Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-08-20 09:38:11 +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
Tamir Duberstein f411b7eddd rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
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>
2025-07-21 01:15:51 +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 22679d807d rust: opp: use c_* types via kernel prelude
Update OPP FFI callback signatures to use `c_int` from the `kernel::prelude`,
instead of accessing it via `kernel::ffi::c_int`.

Although these types are defined in a crate named `ffi`, they are re-exported
via the `kernel::prelude` and should be used from there. This aligns with the
Rust-for-Linux coding guidelines and ensures ABI correctness when interfacing
with C code.

Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Abhinav Ananthu <abhinav.ogl@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-06-23 09:52:45 +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
Viresh Kumar 15bc5c00d1 rust: opp: Move `cfg(CONFIG_OF)` attribute to the top of doc test
Move the `#[cfg(CONFIG_OF)]` attribute to the top of the documentation test
block and hide it. This applies the condition to the entire test and improves
readability.

Placing configuration flags like `CONFIG_OF` at the top serves as a clear
indicator of the conditions under which the example is valid, effectively
acting like configuration metadata for the example itself.

Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/9d93c783cc4419f16dd8942a4359d74bc0149203.1748323971.git.viresh.kumar@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-05-27 15:29:17 +02:00
Viresh Kumar 21d8a6857b rust: opp: Make the doctest example depend on CONFIG_OF
The doctest example uses a function only available for CONFIG_OF and so
the build with doc tests fails when it isn't enabled.

  error[E0599]: no function or associated item named `from_of_cpumask`
  found for struct `rust_doctest_kernel_alloc_kbox_rs_4::kernel::opp::Table`
  in the current scope

Fix this by making the doctest depend on CONFIG_OF.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505260856.ZQWHW2xT-lkp@intel.com/
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/a80bfedcb4d94531dc27d3b48062db5042078e88.1748237646.git.viresh.kumar@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-05-26 13:07:23 +02:00
Viresh Kumar 14f47156cf rust: opp: Extend OPP abstractions with cpufreq support
Extend the OPP abstractions to include support for interacting with the
cpufreq core, including the ability to retrieve frequency tables from
OPP table.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 11:21:11 +05:30
Viresh Kumar ce32e2d47c rust: opp: Add abstractions for the configuration options
Introduce Rust abstractions for the OPP core configuration options,
enabling safe access to various configurable aspects of the OPP
framework.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 10:11:14 +05:30
Viresh Kumar d52c7e868f rust: opp: Add abstractions for the OPP table
Introduce Rust abstractions for `struct opp_table`, enabling access to
OPP tables from Rust.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 10:10:53 +05:30
Viresh Kumar 8f835497b3 rust: opp: Add initial abstractions for OPP framework
Introduce initial Rust abstractions for the Operating Performance Points
(OPP) framework. This includes bindings for `struct dev_pm_opp` and
`struct dev_pm_opp_data`, laying the groundwork for further OPP
integration.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20 10:04:06 +05:30