Merge tag 'rust-hrtimer-for-v6.15-v3' of https://github.com/Rust-for-Linux/linux into rust-next

Pull rust-hrtimer updates from Andreas Hindborg:
 "Introduce Rust support for the 'hrtimer' subsystem:

   - Add a way to use the 'hrtimer' subsystem from Rust. Rust code can
     now set up intrusive timers without allocating when starting the
     timer.

   - Add support for 'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and
     'Pin<&mut _>' as pointer types for use with timer callbacks.

   - Add support for setting clock source and timer mode.

  'kernel' crate:

   - Add 'Arc::as_ptr' for converting an 'Arc' to a raw pointer. This is
     a dependency for the 'hrtimer' API.

   - Add 'Box::into_pin' for converting a 'Box<_>' into a 'Pin<Box<_>>'
     to align with Rust 'alloc'. This is a dependency for the 'hrtimer'
     API."

* tag 'rust-hrtimer-for-v6.15-v3' of https://github.com/Rust-for-Linux/linux:
  rust: hrtimer: add maintainer entry
  rust: hrtimer: add clocksource selection through `ClockId`
  rust: hrtimer: add `HrTimerMode`
  rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>`
  rust: alloc: add `Box::into_pin`
  rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`
  rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`
  rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`
  rust: hrtimer: add `UnsafeHrTimerPointer`
  rust: hrtimer: allow timer restart from timer handler
  rust: hrtimer: implement `HrTimerPointer` for `Arc`
  rust: sync: add `Arc::as_ptr`
  rust: hrtimer: introduce hrtimer support

rust: dma: add `Send` implementation for `CoherentAllocation`

Stephen found a future build failure in linux-next [1]:

    error[E0277]: `*mut MyStruct` cannot be sent between threads safely
      --> samples/rust/rust_dma.rs:47:22
       |
    47 | impl pci::Driver for DmaSampleDriver {
       |                      ^^^^^^^^^^^^^^^ `*mut MyStruct` cannot be sent between threads safely

It is caused by the interaction between commit 935e1d90bf6f ("rust: pci:
require Send for Driver trait implementers") from the driver-core tree,
which fixes a missing concurrency requirement, and commit 9901addae63b
("samples: rust: add Rust dma test sample driver") which adds a sample
that does not satisfy that requirement.

Add a `Send` implementation to `CoherentAllocation`, which allows the
sample (and other future users) to satisfy it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20250324215702.1515ba92@canb.auug.org.au/ [1]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250324174048.1075597-1-ojeda@kernel.org
[ Added number to Closes. Fix typo spotted by Boqun. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: macros: fix `make rusttest` build on macOS

Do not emit `#[link_section = ".modinfo"]` on macOS (i.e. when building
userspace tests); .modinfo is not a legal section specifier in mach-o.

Before this change tests failed to compile:

  ---- ../rust/macros/lib.rs - module (line 66) stdout ----
  rustc-LLVM ERROR: Global variable '_ZN8rust_out13__module_init13__module_init27__MY_DEVICE_DRIVER_MODULE_017h141f80536770e0d4E' has an invalid section specifier '.modinfo': mach-o section specifier requires a segment and section separated by a comma.
  Couldn't compile the test.
  ---- ../rust/macros/lib.rs - module (line 33) stdout ----
  rustc-LLVM ERROR: Global variable '_ZN8rust_out13__module_init13__module_init20__MY_KERNEL_MODULE_017h5d79189564b41e07E' has an invalid section specifier '.modinfo': mach-o section specifier requires a segment and section separated by a comma.
  Couldn't compile the test.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250210-macros-section-v2-1-3bb9ff44b969@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: block: refactor to use `&raw mut`

Replace all occurrences (one) of `addr_of_mut!(place)` with
`&raw mut place`.

This will allow us to reduce macro complexity, and improve consistency
with existing reference syntax as `&raw mut` is similar to `&mut` making
it fit more naturally with other existing code.

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://github.com/Rust-for-Linux/linux/issues/1148
Signed-off-by: Antonio Hickey <contact@antoniohickey.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250320020740.1631171-17-contact@antoniohickey.com
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: enable `raw_ref_op` feature

Since Rust 1.82.0 the `raw_ref_op` feature is stable [1].

By enabling this feature we can use `&raw const place` and
`&raw mut place` instead of using `addr_of!(place)` and
`addr_of_mut!(place)` macros.

Allowing us to reduce macro complexity, and improve consistency
with existing reference syntax as `&raw const`, `&raw mut` are
similar to `&`, `&mut` making it fit more naturally with other
existing code.

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: https://github.com/Rust-for-Linux/linux/issues/1148
Link: https://blog.rust-lang.org/2024/10/17/Rust-1.82.0.html#native-syntax-for-creating-a-raw-pointer
Signed-off-by: Antonio Hickey <contact@antoniohickey.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250320020740.1631171-2-contact@antoniohickey.com
[ Removed dashed line change as discussed. Added Link to the explanation
  of the feature in the Rust 1.82.0 release blog post. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: uaccess: name the correct function

Correctly refer to `reserve` rather than `try_reserve` in a comment.  This
comment has been incorrect since inception in commit 1b580e7b9ba2 ("rust:
uaccess: add userspace pointers").

Fixes: 1b580e7b9ba2 ("rust: uaccess: add userspace pointers")
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net>
Link: https://lore.kernel.org/r/20250317-uaccess-typo-reserve-v1-1-bbfcb45121f3@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: rbtree: fix comments referring to Box instead of KBox

Several safety comments in the RBTree implementation still refer to
"Box::from_raw" and "Box::into_raw", but the code actually uses KBox.
These comments were not updated when the implementation transitioned
from using Box to KBox.

Fixes: 8373147ce496 ("rust: treewide: switch to our kernel `Box` type")
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250315-rbtree-comment-fixes-v1-1-51f72c420ff0@posteo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: hrtimer: add maintainer entry

Add Andreas Hindborg as maintainer for Rust `hrtimer` abstractions. Also
add Boqun Feng as reviewer.

Acked-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-13-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: add clocksource selection through `ClockId`

Allow selecting a clock source for timers by passing a `ClockId`
variant to `HrTimer::new`.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-12-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: add `HrTimerMode`

Allow selection of timer mode by passing a `HrTimerMode` variant to
`HrTimer::new`.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-11-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>`

Allow `Pin<Box<T>>` to be the target of a timer callback.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-10-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: alloc: add `Box::into_pin`

Add an associated function to convert a `Box<T>` into a `Pin<Box<T>>`.

Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-9-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`

Allow pinned mutable references to structs that contain a `HrTimer` node to
be scheduled with the `hrtimer` subsystem.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-8-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>`

Allow pinned references to structs that contain a `HrTimer` node to be
scheduled with the `hrtimer` subsystem.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-7-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: add `hrtimer::ScopedHrTimerPointer`

Add the trait `ScopedHrTimerPointer` to allow safe use of stack allocated
timers. Safety is achieved by pinning the stack in place while timers are
running.

Implement the trait for all types that implement `UnsafeHrTimerPointer`.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-6-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: add `UnsafeHrTimerPointer`

Add a trait to allow unsafely queuing stack allocated timers.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-5-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: allow timer restart from timer handler

Allow timer handlers to report that they want a timer to be restarted after
the timer handler has finished executing.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-4-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: str: implement `strip_prefix` for `BStr`

Implement `strip_prefix` for `BStr` by deferring to `slice::strip_prefix`
on the underlying `&[u8]`.

Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250227-module-params-v3-v8-4-ceeee85d9347@kernel.org
[ Pluralized section name. Hid `use`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr`

Implement `AsRef<BStr>` for `[u8]` and `BStr` so these can be used
interchangeably for operations on `BStr`.

Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250227-module-params-v3-v8-3-ceeee85d9347@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: str: implement `Index` for `BStr`

The `Index` implementation on `BStr` was lost when we switched `BStr` from
a type alias of `[u8]` to a newtype. Add back `Index` by implementing
`Index` for `BStr` when `Index` would be implemented for `[u8]`.

Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250227-module-params-v3-v8-2-ceeee85d9347@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: str: implement `PartialEq` for `BStr`

Implement `PartialEq` for `BStr` by comparing underlying byte slices.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250227-module-params-v3-v8-1-ceeee85d9347@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

MAINTAINERS: add entry for Rust dma mapping helpers device driver API

Add an entry for the Rust dma mapping helpers abstractions.

Nacked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Link: https://lore.kernel.org/r/20250317185345.2608976-5-abdiel.janulgue@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

samples: rust: add Rust dma test sample driver

Add a simple driver to exercise the basics of the Rust DMA
coherent allocator bindings.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250317185345.2608976-4-abdiel.janulgue@gmail.com
[ Renamed Kconfig symbol and moved it up. Migrated to the new
  `authors` key in `module!`. Fixed module name in description
  and typo in commit message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: add dma coherent allocator abstraction

Add a simple dma coherent allocator rust abstraction. Based on
Andreas Hindborg's dma abstractions from the rnvme driver, which
was also based on earlier work by Wedson Almeida Filho.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250317185345.2608976-3-abdiel.janulgue@gmail.com
Nacked-by: Christoph Hellwig <hch@lst.de>
[ Removed period. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: error: Add EOVERFLOW

Trivial addition for missing EOVERFLOW error. This is used by a
subsequent patch that might require returning EOVERFLOW as a result
of `checked_mul`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250317185345.2608976-2-abdiel.janulgue@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: kunit: allow to know if we are in a test

In some cases, we need to call test-only code from outside the test
case, for example, to mock a function or a module.

In order to check whether we are in a test or not, we need to test if
`CONFIG_KUNIT` is set.
Unfortunately, we cannot rely only on this condition because:
- a test could be running in another thread,
- some distros compile KUnit in production kernels, so checking at runtime
  that `current->kunit_test != NULL` is required.

Forturately, KUnit provides an optimised check in
`kunit_get_current_test()`, which checks CONFIG_KUNIT, a global static
key, and then the current thread's running KUnit test.

Add a safe wrapper function around this to know whether or not we are in
a KUnit test and examples showing how to mock a function and a module.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: David Gow <davidgow@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250307090103.918788-4-davidgow@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: macros: add macro to easily run KUnit tests

Add a new procedural macro (`#[kunit_tests(kunit_test_suit_name)]`) to
run KUnit tests using a user-space like syntax.

The macro, that should be used on modules, transforms every `#[test]`
in a `kunit_case!` and adds a `kunit_unsafe_test_suite!` registering
all of them.

The only difference with user-space tests is that instead of using
`#[cfg(test)]`, `#[kunit_tests(kunit_test_suit_name)]` is used.

Note that `#[cfg(CONFIG_KUNIT)]` is added so the test module is not
compiled when `CONFIG_KUNIT` is set to `n`.

Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250307090103.918788-3-davidgow@google.com
[ Removed spurious (in rendered form) newline in docs. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: kunit: add KUnit case and suite macros

Add a couple of Rust const functions and macros to allow to develop
KUnit tests without relying on generated C code:

 - The `kunit_unsafe_test_suite!` Rust macro is similar to the
   `kunit_test_suite` C macro. It requires a NULL-terminated array of
   test cases (see below).
 - The `kunit_case` Rust function is similar to the `KUNIT_CASE` C macro.
   It generates as case from the name and function.
 - The `kunit_case_null` Rust function generates a NULL test case, which
   is to be used as delimiter in `kunit_test_suite!`.

While these functions and macros can be used on their own, a future
patch will introduce another macro to create KUnit tests using a
user-space like syntax.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Co-developed-by: Matt Gilbride <mattgilbride@google.com>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: David Gow <davidgow@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250307090103.918788-2-davidgow@google.com
[ Applied Markdown in comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: add kunitconfig

The kunitconfig file in a directory is used by kunit.py to enable all
necessary kernel configurations to run the tests in that subdirectory.
Add such a file for rust/.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250208-rust-kunit-v1-2-94a026be6d72@weissschuh.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pass correct target to bindgen on Usermode Linux

Usermode Linux uses "um" as primary architecture name and the underlying
physical architecture is provided in "SUBARCH".

Resolve the target architecture flags through that underlying
architecture.

This is the same pattern as used by scripts/Makefile.clang from which
the bindgen flags are derived.

[ David says:

      (...) this is enough to get Rust-for-Linux working with gcc under
      64-bit UML on my system.

    - Miguel ]

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Gow <davidgow@googl.ecom>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://lore.kernel.org/r/20250208-rust-kunit-v1-1-94a026be6d72@weissschuh.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

MAINTAINERS: add entry for the `pin-init` crate

Add maintainers entry for the `pin-init` crate.

This crate is already being maintained by me, but until now there
existed two different versions: the version inside of the kernel tree
and a user-space version at [1]. The previous patches synchronized these
two versions to reduce the maintenance burden. In order to keep them
synchronized from now on, separate the maintenance from other Rust code.

Link: https://github.com/Rust-for-Linux/pin-init
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250308110339.2997091-23-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: re-enable doctests

The pin-init crate is now compiled in a standalone fashion, so revert
the earlier commit that disabled the doctests in pin-init in order to
avoid build errors while transitioning the crate into a standalone
version.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-22-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: add miscellaneous files from the user-space version

Add readme and contribution guidelines of the user-space version of
pin-init.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-21-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: miscellaneous synchronization with the user-space version

Remove the last differences between the kernel version and the
user-space version.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20250308110339.2997091-20-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: internal: synchronize with user-space version

Synchronize the internal macros crate with the user-space version that
uses the quote crate [1] instead of a custom `quote!` macro. The imports
in the different version are achieved using `cfg` on the kernel config
value. This cfg is always set in the kernel and never set in the
user-space version.

Since the quote crate requires the proc_macro2 crate, imports also need
to be adjusted and `.into()` calls have to be inserted.

Link: https://crates.io/crates/quote
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@Kloenk.dev>
Link: https://lore.kernel.org/r/20250308110339.2997091-19-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: synchronize documentation with the user-space version

Synchronize documentation and examples with the user-space version.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-18-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: add `std` and `alloc` support from the user-space version

To synchronize the kernel's version of pin-init with the user-space
version, introduce support for `std` and `alloc`. While the kernel uses
neither, the user-space version has to support both. Thus include the
required `#[cfg]`s and additional code.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-17-benno.lossin@proton.me
[ Undo the temporary `--extern force:alloc` since now we have contents
  for `alloc` here. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: make pin-init its own crate

Rename relative paths inside of the crate to still refer to the same
items, also rename paths inside of the kernel crate and adjust the build
system to build the crate.

[ Remove the `expect` (and thus the `lint_reasons` feature) since
  the tree now uses `quote!` from `rust/macros/export.rs`. Remove the
  `TokenStream` import removal, since it is now used as well.

  In addition, temporarily (i.e. just for this commit) use an `--extern
  force:alloc` to prevent an unknown `new_uninit` error in the `rustdoc`
  target. For context, please see a similar case in:

      https://lore.kernel.org/lkml/20240422090644.525520-1-ojeda@kernel.org/

  And adjusted the message above. - Miguel ]

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-16-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: add pin-init crate build infrastructure

Add infrastructure for moving the initialization API to its own crate.
Covers all make targets such as `rust-analyzer` and `rustdoc`. The tests
of pin-init are not added to `rusttest`, as they are already tested in
the user-space repository [1].

Link: https://github.com/Rust-for-Linux/pin-init
Co-developed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-15-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: change the way the `paste!` macro is called

Change the paste macro path from `::kernel::macros::paste!` to use
`$crate::init::macros::paste!` instead, which links to
`::macros::paste!`. This is because the pin-init crate will be a
dependency of the kernel, so it itself cannot have the kernel as a
dependency.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-14-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: remove kernel-crate dependency

In order to make pin-init a standalone crate, remove dependencies on
kernel-specific code such as `ScopeGuard` and `KBox`.

`ScopeGuard` is only used in the `[pin_]init_array_from_fn` functions
and can easily be replaced by a primitive construct.

`KBox` is only used for type variance of unsized types and can also
easily be replaced.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-13-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: fix documentation links

Before switching to compile the `pin-init` crate directly, change
any links that would be invalid to links that are valid both before and
after the switch.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-12-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: add `ZeroableOption` and implement it instead of `Zeroable` for `Option<Box<T, A>>`

When making pin-init its own crate, `Zeroable` will no longer be defined
by the kernel crate and thus implementing it for `Option<Box<T, A>>` is
no longer possible due to the orphan rule.
For this reason introduce a new `ZeroableOption` trait that circumvents
this problem.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-11-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: move impl `Zeroable` for `Opaque` and `Option<KBox<T>>` into the kernel crate

In order to make pin-init a standalone crate, move kernel-specific code
directly into the kernel crate. Since `Opaque<T>` and `KBox<T>` are part
of the kernel, move their `Zeroable` implementation into the kernel
crate.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20250308110339.2997091-10-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: move `InPlaceInit` and impls of `InPlaceWrite` into the kernel crate

In order to make pin-init a standalone crate, move kernel-specific code
directly into the kernel crate. This includes the `InPlaceInit<T>`
trait, its implementations and the implementations of `InPlaceWrite` for
`Arc` and `UniqueArc`. All of these use the kernel's error type which
will become unavailable in pin-init.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-9-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: move the default error behavior of `try_[pin_]init`

Move the ability to just write `try_pin_init!(Foo { a <- a_init })`
(note the missing `? Error` at the end) into the kernel crate.
Remove this notation from the pin-init crate, since the default when no
error is specified is the kernel-internal `Error` type. Instead add two
macros in the kernel crate that serve this default and are used instead
of the ones from `pin-init`.

This is done, because the `Error` type that is used as the default is
from the kernel crate and it thus prevents making the pin-init crate
standalone.

In order to not cause a build error due to a name overlap, the macros in
the pin-init crate are renamed, but this change is reverted in a future
commit when it is a standalone crate.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-8-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: call `try_[pin_]init!` from `[pin_]init!` instead of `__init_internal!`

The `[pin_]init!` macros have the same behavior as the `try_[pin_]init!`
macros, except that they set the error type to `Infallible`.
Instead of calling the primitive `__init_internal!` with the correct
parameters, the same can thus be achieved by calling `try_[pin_]init!`.
Since this makes it more clear what their behavior is, simplify the
implementations of `[pin_]init!`.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-7-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: change examples to the user-space version

Replace the examples in the documentation by the ones from the
user-space version and introduce the standalone examples from the
user-space version such as the `CMutex<T>` type.

The `CMutex<T>` example from the pinned-init repository [1] is used in
several documentation examples in the user-space version instead of the
kernel `Mutex<T>` type (as it's not available). In order to split off
the pin-init crate, all examples need to be free of kernel-specific
types.

Link: https://github.com/rust-for-Linux/pinned-init
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-6-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: pin-init: move proc-macro documentation into pin-init crate

Move the documentation of proc-macros from pin-init-internal into
pin-init. This is because documentation can only reference types from
dependencies and pin-init-internal cannot have pin-init as a dependency,
as that would be cyclic.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-5-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: add extensions to the pin-init crate and move relevant documentation there

In preparation of splitting off the pin-init crate from the kernel
crate, move all kernel-specific documentation from pin-init back into
the kernel crate.

Also include an example from the user-space version [1] adapted to the
kernel.

The new `init.rs` file will also be populated by kernel-specific
extensions to the pin-init crate by the next commits.

Link: https://github.com/Rust-for-Linux/pin-init/blob/c1417c64c71229f0fd444d75e88f33e3c547c829/src/lib.rs#L161
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-4-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: move pin-init API into its own directory

In preparation of splitting off the pin-init crate from the kernel
crate, move all pin-init API code (including proc-macros) into
`rust/pin-init`.

Moved modules have their import path adjusted via the `#[path = "..."]`
attribute. This allows the files to still be imported in the kernel
crate even though the files are in different directories.

Code that is moved out of files (but the file itself stays where it is)
is imported via the `include!` macro. This also allows the code to be
moved while still being part of the kernel crate.

Note that this commit moves the generics parsing code out of the GPL-2.0
file `rust/macros/helpers.rs` into the Apache-2.0 OR MIT file
`rust/pin_init/internal/src/helpers.rs`. I am the sole author of that
code and it already is available with that license at [1].
The same is true for the entry-points of the proc-macros `pin_data`,
`pinned_drop` and `derive_zeroable` in `rust/macros/lib.rs` that are
moved to `rust/pin_data/internal/src/lib.rs`. Although there are some
smaller patches that fix the doctests.

Link: https://github.com/Rust-for-Linux/pinned-init
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-3-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: init: disable doctests

The build system cannot handle doctests in the kernel crate in files
outside of `rust/kernel/`. Subsequent commits will move files out of
that directory, but will still compile them as part of the kernel crate.
Thus ignore all doctests in the to-be-moved files.

Leave tests disabled until they are separated into their own crate and
they stop causing breakage.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-2-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: error: extend the Result documentation

Extend the Result documentation by some guidelines and examples how
to handle Result error cases gracefully. And how to not handle them.

While at it fix one missing `Result` link in the existing documentation.

[ Moved links out-of-line for improved readability. Fixed `srctree`
  link. Sorted out-of-line links. Added newlines for consistency
  with other docs. Applied paragraph break suggestion. Reworded
  slightly the docs in a couple places. Added Markdown.

  In addition, added `#[allow(clippy::single_match)` for the first
  example. It cannot be an `expect` since due to a difference introduced
  in Rust 1.85.0 when there are comments in the arms of the `match`.
  Reported it upstream, but it was intended:

      https://github.com/rust-lang/rust-clippy/issues/14418

  Perhaps Clippy will lint about it in the future, but without autofix:

      https://github.com/rust-lang/rust-clippy/pull/14420

    - Miguel ]

Link: https://lore.kernel.org/rust-for-linux/CANiq72keOdXy0LFKk9SzYWwSjiD710v=hQO4xi+5E4xNALa6cA@mail.gmail.com/
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20250122054719.595878-1-dirk.behme@de.bosch.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: hrtimer: implement `HrTimerPointer` for `Arc`

Allow the use of intrusive `hrtimer` fields in structs that are managed by
an `Arc` by implementing `HrTimerPointer` and `RawTimerCallbck` for `Arc`.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-3-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: sync: add `Arc::as_ptr`

Add a method to get a pointer to the data contained in an `Arc`.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-2-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: hrtimer: introduce hrtimer support

Add support for intrusive use of the hrtimer system. For now,
only add support for embedding one timer per Rust struct.

The hrtimer Rust API is based on the intrusive style pattern introduced by
the Rust workqueue API.

Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-1-73586e2bd5f1@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

rust: types: add intra-doc links for `Opaque<T>`

We use intra-doc links wherever possible. Thus add a couple missing ones
for `Opaque<T>`.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250305053438.1532397-1-dirk.behme@de.bosch.com
[ Reworded. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: module: introduce `authors` key

In the `module!` macro, the `author` field is currently of type `String`.

Since modules can have multiple authors, this limitation prevents
specifying more than one.

Add an `authors` field as `Option<Vec<String>>` to allow creating
modules with multiple authors, and change the documentation and all
current users to use it. Eventually, the single `author` field may
be removed.

[ The `modinfo` key needs to still be `author`; otherwise, tooling
  may not work properly, e.g.:

      $ modinfo --author samples/rust/rust_print.ko
      Rust for Linux Contributors

  I have also kept the original `author` field (undocumented), so
  that we can drop it more easily in a kernel cycle or two.

    - Miguel ]

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/244
Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Link: https://lore.kernel.org/r/20250309175712.845622-2-trintaeoitogc@gmail.com
[ Fixed `modinfo` key. Kept `author` field. Reworded message
  accordingly. Updated my email. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

panic_qr: use new #[export] macro

This validates at compile time that the signatures match what is in the
header file. It highlights one annoyance with the compile-time check,
which is that it can only be used with functions marked unsafe.

If the function is not unsafe, then this error is emitted:

error[E0308]: `if` and `else` have incompatible types
   --> <linux>/drivers/gpu/drm/drm_panic_qr.rs:987:19
    |
986 | #[export]
    | --------- expected because of this
987 | pub extern "C" fn drm_panic_qr_max_data_size(version: u8, url_len: usize) -> usize {
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected unsafe fn, found safe fn
    |
    = note: expected fn item `unsafe extern "C" fn(_, _) -> _ {kernel::bindings::drm_panic_qr_max_data_size}`
               found fn item `extern "C" fn(_, _) -> _ {drm_panic_qr_max_data_size}`

The signature declarations are moved to a header file so it can be
included in the Rust bindings helper, and the extern keyword is removed
as it is unnecessary.

Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-5-41fbad85a27f@google.com
[ Fixed `rustfmt`. Moved on top the unsafe requirement comment to follow
  the usual style, and slightly reworded it for clarity. Formatted
  bindings helper comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

print: use new #[export] macro for rust_fmt_argument

This moves the rust_fmt_argument function over to use the new #[export]
macro, which will verify at compile-time that the function signature
matches what is in the header file.

Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-4-41fbad85a27f@google.com
[ Removed period as requested by Andy. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: add #[export] macro

Rust has two different tools for generating function declarations to
call across the FFI boundary:

* bindgen. Generates Rust declarations from a C header.
* cbindgen. Generates C headers from Rust declarations.

However, we only use bindgen in the kernel. This means that when C code
calls a Rust function by name, its signature must be duplicated in both
Rust code and a C header, and the signature needs to be kept in sync
manually.

Introducing cbindgen as a mandatory dependency to build the kernel would
be a rather complex and large change, so we do not consider that at this
time. Instead, to eliminate this manual checking, introduce a new macro
that verifies at compile time that the two function declarations use the
same signature. The idea is to run the C declaration through bindgen,
and then have rustc verify that the function pointers have the same
type.

The signature must still be written twice, but at least you can no
longer get it wrong. If the signatures don't match, you will get errors
that look like this:

error[E0308]: `if` and `else` have incompatible types
  --> <linux>/rust/kernel/print.rs:22:22
   |
21 | #[export]
   | --------- expected because of this
22 | unsafe extern "C" fn rust_fmt_argument(
   |                      ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8`
   |
   = note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}`
              found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}`

It is unfortunate that the error message starts out by saying "`if` and
`else` have incompatible types", but I believe the rest of the error
message is reasonably clear and not too confusing.

Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-3-41fbad85a27f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: macros: support additional tokens in quote!

This gives the quote! macro support for the following additional tokens:

* The = token.
* The _ token.
* The # token. (when not followed by an identifier)
* Using #my_var with variables of type Ident.

Additionally, some type annotations are added to allow cases where
groups are empty. For example, quote! does support () in the input, but
only when it is *not* empty. When it is empty, there are zero `.push`
calls, so the compiler can't infer the item type and also emits a
warning about it not needing to be mutable.

These additional quote! features are used by a new proc macro that
generates code looking like this:

const _: () = {
    if true {
        ::kernel::bindings::#name
    } else {
        #name
    };
};

where #name has type Ident.

Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-2-41fbad85a27f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: fix signature of rust_fmt_argument

Without this change, the rest of this series will emit the following
error message:

error[E0308]: `if` and `else` have incompatible types
  --> <linux>/rust/kernel/print.rs:22:22
   |
21 | #[export]
   | --------- expected because of this
22 | unsafe extern "C" fn rust_fmt_argument(
   |                      ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8`
   |
   = note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}`
              found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}`

The error may be different depending on the architecture.

To fix this, change the void pointer argument to use a const pointer,
and change the imports to use crate::ffi instead of core::ffi for
integer types.

Fixes: 787983da7718 ("vsprintf: add new `%pA` format specifier")
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-1-41fbad85a27f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

MAINTAINERS: rust: add tree field for RUST [ALLOC]

In the Rust subsystem we are starting to add new subentries which will
have their own trees. Those trees will be part of linux-next and will
be sent as PRs to be merged into rust-next.

Thus do the same for the existing subentry we already have: RUST [ALLOC].

Acked-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250308164258.811040-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: improve lifetimes markup

Improve lifetimes markup; e.g. from:

    /// ... 'a ...

to:

    /// ... `'a` ...

This will make lifetimes display as code span with Markdown and make it
more consistent with rest of the docs.

Link: https://github.com/Rust-for-Linux/linux/issues/1138
Signed-off-by: Borys Tyran <borys.tyran@protonmail.com>
Link: https://lore.kernel.org/r/20250207142437.112435-1-borys.tyran@protonmail.com
[ Reworded and changed Closes tag to Link. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

scripts: rust: mention file name in error messages

Improve two error messages in the script by mentioning the doctest file
path from which the doctest was generated from.

This will allow, in case the conversion fails, to get directly the file
name triggering the issue, making the bug fixing process faster.

Signed-off-by: Guillaume Gomez <guillaume1.gomez@gmail.com>
Link: https://lore.kernel.org/r/20250228170530.950268-2-guillaume1.gomez@gmail.com
[ Reworded and removed an unneeded added parameter comma. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

docs: rust: Add error handling sections

Add error handling sections to the documentation and use it
to link to the existing code documentation. This will allow
to extend that documentation, use intra-doc links and test
the examples.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/rust-for-linux/CANiq72keOdXy0LFKk9SzYWwSjiD710v=hQO4xi+5E4xNALa6cA@mail.gmail.com/
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20250115062552.1970768-1-dirk.behme@de.bosch.com
[ Slightly tweaked wording. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: list: make the cursor point between elements

I've been using the linked list cursor for a few different things, and I
find it inconvenient to use because all of the functions have signatures
along the lines of `Self -> Option<Self>`. The root cause of these
signatures is that the cursor points *at* an element, rather than
*between* two elements.

Thus, change the cursor API to point between two elements. This is
inspired by the stdlib linked list (well, really by this guy [1]), which
also uses cursors that point between elements.

The `peek_next` method returns a helper that lets you look at and
optionally remove the element, as one common use-case of cursors is to
iterate a list to look for an element, then remove that element.

For many of the methods, this will reduce how many we need since they
now just need a prev/next method, instead of the current state where you
may end up needing all of curr/prev/next. Also, if we decide to add a
function for splitting a list into two lists at the cursor, then a
cursor that points between elements is exactly what makes the most
sense.

Another advantage is that this means you can now have a cursor into an
empty list.

Link: https://rust-unofficial.github.io/too-many-lists/sixth-cursors-intro.html
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250210-cursor-between-v7-2-36f0215181ed@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: list: extract common code for insertion

To prepare for a new cursor API that has the ability to insert elements
into the list, extract the common code needed for this operation into a
new `insert_inner` method.

Both `push_back` and `push_front` are updated to use the new function.

Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250210-cursor-between-v7-1-36f0215181ed@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: task: make Pid type alias public

The Pid type alias represents the integer type used for pids in the
kernel. It's the Rust equivalent to pid_t, and there are various methods
on Task that use Pid as the return type.

Binder needs to use Pid as the type for function arguments and struct
fields in many places. Thus, make the type public so that Binder can
access it.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20250130-task-pid-pub-v1-1-508808bcfcdc@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust: alloc: make `ReallocFunc::call` inline

This function can be called with different function pointers when
different allocator (e.g. Kmalloc, Vmalloc, KVmalloc), however since
this function is not polymorphic, only one instance is generated,
and function pointers are used. Given that this function is called
for any Rust-side allocation/deallocation, performance matters a lot,
so making this function inlineable.

This is discovered when doing helper inlining work, since it's discovered
that even with helpers inlined, rust_helper_ symbols are still present
in final vmlinux binary, and it turns out this function is inhibiting
the inlining, and introducing indirect function calls.

Signed-off-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250105194054.545201-4-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

MAINTAINERS: add Danilo Krummrich as Rust reviewer

Danilo has been involved with the Rust for Linux project for a year now.
He is primarily working on the Nova GPU driver [1][2].

In addition, he has been active in the mailing list and most recently
submitted the Device / Driver PCI / Platform series.

He is also already a maintainer of `RUST [ALLOC]` as well as several
other DRM-related entries.

His expertise developing Rust abstractions and APIs for one of the major
users of Rust in the kernel will be very useful to have around in the
future. Thus add him to the `RUST` entry as reviewer.

Link: https://rust-for-linux.com/nova-gpu-driver
Link: https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy@cassiopeiae/
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250129215948.135486-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Linux 6.14-rc5

Merge tag 'dmaengine-fix-6.14' of git://git./linux/kernel/git/vkoul/dmaengine

Pull dmaengine fixes from Vinod Koul:

 - tegra210 div_u64 divison and max page fixes

 - revert Qualcomm unavailable register workaround which is causing
   regression, fixes have been proposed but still gaps are present so
   revert this for now

* tag 'dmaengine-fix-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine:
  dmaengine: Revert "dmaengine: qcom: bam_dma: Avoid writing unavailable register"
  dmaengine: tegra210-adma: check for adma max page
  dmaengine: tegra210-adma: Use div_u64 for 64 bit division

Merge tag 'phy-fixes-6.14' of git://git./linux/kernel/git/phy/linux-phy

Pull phy fixes from Vinod Koul:

 - rockchip phy kconfig dependency fix with USB_COMMON and regression
   fix for old DT

 - stm32 phy overflow assertion fix

 - exonysfs phy refclk masks fix and power gate on exit fix

 - freescale fix for clock dividor valid range

 - TI regmap syscon register fix

 - tegra reset registers on init fix

* tag 'phy-fixes-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy:
  phy: tegra: xusb: reset VBUS & ID OVERRIDE
  phy: ti: gmii-sel: Do not use syscon helper to build regmap
  phy: exynos5-usbdrd: gs101: ensure power is gated to SS phy in phy_exit()
  phy: freescale: fsl-samsung-hdmi: Limit PLL lock detection clock divider to valid range
  phy: exynos5-usbdrd: fix MPLL_MULTIPLIER and SSC_REFCLKSEL masks in refclk
  phy: stm32: Fix constant-value overflow assertion
  phy: rockchip: naneng-combphy: compatible reset with old DT
  phy: rockchip: fix Kconfig dependency more

Merge tag 'gpio-fixes-for-v6.14-rc5' of git://git./linux/kernel/git/brgl/linux

Pull gpio fix from Bartosz Golaszewski:

 - fix a buggy get_direction() retval check

* tag 'gpio-fixes-for-v6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpiolib: Fix Oops in gpiod_direction_input_nonotify()

Merge tag 'mips-fixes_6.14_2' of git://git./linux/kernel/git/mips/linux

Pull MIPS fix from Thomas Bogendoerfer:
 "Fix fallout of /scripts/sorttable cleanup"

* tag 'mips-fixes_6.14_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Ignore relocs against __ex_table for relocatable kernel

Merge tag 'v6.14-rc4-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client fix from Steve French:
 "Fix SMB1 netfs client regression"

* tag 'v6.14-rc4-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix the smb1 readv callback to correctly call netfs

Merge tag 'arm64-fixes' of git://git./linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "Ryan's been hard at work finding and fixing mm bugs in the arm64 code,
  so here's a small crop of fixes for -rc5.

  The main changes are to fix our zapping of non-present PTEs for
  hugetlb entries created using the contiguous bit in the page-table
  rather than a block entry at the level above. Prior to these fixes, we
  were pulling the contiguous bit back out of the PTE in order to
  determine the size of the hugetlb page but this is clearly bogus if
  the thing isn't present and consequently both the clearing of the
  PTE(s) and the TLB invalidation were unreliable.

  Although the problem was found by code inspection, we really don't
  want this sitting around waiting to trigger and the changes are CC'd
  to stable accordingly.

  Note that the diffstat looks a lot worse than it really is;
  huge_ptep_get_and_clear() now takes a size argument from the core code
  and so all the arch implementations of that have been updated in a
  pretty mechanical fashion.

   - Fix a sporadic boot failure due to incorrect randomization of the
     linear map on systems that support it

   - Fix the zapping (both clearing the entries *and* invalidating the
     TLB) of hugetlb PTEs constructed using the contiguous bit"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlb: Fix flush_hugetlb_tlb_range() invalidation level
  arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes
  mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()
  arm64/mm: Fix Boot panic on Ampere Altra

Merge tag 'i2c-for-6.14-rc5' of git://git./linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "All driver fixes this time:

   - fix interrupt initialization sequence (npcm)

   - fix frequency setting (ls2x)

   - re-enable interrupts properly at irq handler's exit (amd-asf)"

* tag 'i2c-for-6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: amd-asf: Fix EOI register write to enable successive interrupts
  i2c: ls2x: Fix frequency division register access
  i2c: npcm: disable interrupt enable bit before devm_request_irq

Merge tag 'ata-6.14-rc5' of git://git./linux/kernel/git/libata/linux

Pull ata fixes from Niklas Cassel:

 - Fix a regression where the enablement of the PHYs would be skipped
   for device trees without any port child nodes (me)

 - Revert ATA_QUIRK_NOLPM for Samsung SSD 870 QVO drives, as it stops
   systems from entering lower package states. LPM works on newer
   firmware versions. We will need a more refined quirk that only
   targets the older firmware versions (me)

* tag 'ata-6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
  Revert "ata: libata-core: Add ATA_QUIRK_NOLPM for Samsung SSD 870 QVO drives"
  ata: ahci: Make ahci_ignore_port() handle empty mask_port_map

Merge tag 'for-linus' of git://git./virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Fix TCR_EL2 configuration to not use the ASID in TTBR1_EL2 and not
     mess-up T1SZ/PS by using the HCR_EL2.E2H==0 layout.

   - Bring back the VMID allocation to the vcpu_load phase, ensuring
     that we only setup VTTBR_EL2 once on VHE. This cures an ugly race
     that would lead to running with an unallocated VMID.

  RISC-V:

   - Fix hart status check in SBI HSM extension

   - Fix hart suspend_type usage in SBI HSM extension

   - Fix error returned by SBI IPI and TIME extensions for unsupported
     function IDs

   - Fix suspend_type usage in SBI SUSP extension

   - Remove unnecessary vcpu kick after injecting interrupt via IMSIC
     guest file

  x86:

   - Fix an nVMX bug where KVM fails to detect that, after nested
     VM-Exit, L1 has a pending IRQ (or NMI).

   - To avoid freeing the PIC while vCPUs are still around, which would
     cause a NULL pointer access with the previous patch, destroy vCPUs
     before any VM-level destruction.

   - Handle failures to create vhost_tasks"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: retry nx_huge_page_recovery_thread creation
  vhost: return task creation error instead of NULL
  KVM: nVMX: Process events on nested VM-Exit if injectable IRQ or NMI is pending
  KVM: x86: Free vCPUs before freeing VM state
  riscv: KVM: Remove unnecessary vcpu kick
  KVM: arm64: Ensure a VMID is allocated before programming VTTBR_EL2
  KVM: arm64: Fix tcr_el2 initialisation in hVHE mode
  riscv: KVM: Fix SBI sleep_type use
  riscv: KVM: Fix SBI TIME error generation
  riscv: KVM: Fix SBI IPI error generation
  riscv: KVM: Fix hart suspend_type use
  riscv: KVM: Fix hart suspend status check

Revert "ata: libata-core: Add ATA_QUIRK_NOLPM for Samsung SSD 870 QVO drives"

This reverts commit cc77e2ce187d26cc66af3577bf896d7410eb25ab.

It was reported that adding ATA_QUIRK_NOLPM for Samsung SSD 870 QVO drives
breaks entering lower package states for certain systems.

It turns out that Samsung SSD 870 QVO actually has working LPM when using
a recent SSD firmware version.

The author of commit cc77e2ce187d ("ata: libata-core: Add ATA_QUIRK_NOLPM
for Samsung SSD 870 QVO drives") reported himself that only older SSD
firmware versions have broken LPM:
https://lore.kernel.org/stable/93c10d38-718c-459d-84a5-4d87680b4da7@debian.org/

Unfortunately, he did not specify which older firmware version he was using
which had broken LPM.

Let's revert this quirk, which has FW version field specified as NULL
(which means that it applies for all Samsung SSD 870 QVO firmware versions)
for now. Once the author reports which older firmware version(s) that are
broken, we can create a more fine grained quirk, which populates the FW
version field accordingly.

Fixes: cc77e2ce187d ("ata: libata-core: Add ATA_QUIRK_NOLPM for Samsung SSD 870 QVO drives")
Reported-by: Dieter Mummenschanz <dmummenschanz@web.de>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219747
Link: https://lore.kernel.org/r/20250228122603.91814-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

kvm: retry nx_huge_page_recovery_thread creation

A VMM may send a non-fatal signal to its threads, including vCPU tasks,
at any time, and thus may signal vCPU tasks during KVM_RUN.  If a vCPU
task receives the signal while its trying to spawn the huge page recovery
vhost task, then KVM_RUN will fail due to copy_process() returning
-ERESTARTNOINTR.

Rework call_once() to mark the call complete if and only if the called
function succeeds, and plumb the function's true error code back to the
call_once() invoker.  This provides userspace with the correct, non-fatal
error code so that the VMM doesn't terminate the VM on -ENOMEM, and allows
subsequent KVM_RUN a succeed by virtue of retrying creation of the NX huge
page task.

Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
[implemented the kvm user side]
Signed-off-by: Keith Busch <kbusch@kernel.org>
Message-ID: <20250227230631.303431-3-kbusch@meta.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

vhost: return task creation error instead of NULL

Lets callers distinguish why the vhost task creation failed. No one
currently cares why it failed, so no real runtime change from this
patch, but that will not be the case for long.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Message-ID: <20250227230631.303431-2-kbusch@meta.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'thermal-6.14-rc5' of git://git./linux/kernel/git/rafael/linux-pm

Pull thermal control fixes from Rafael Wysocki:
 "These fix the processing of DT thermal properties and the Power
  Allocator thermal governor:

   - Fix parsing cooling-maps in DT for trip points with more than one
     cooling device (Rafael Wysocki)

   - Fix granted_power computation in the Power Allocator thermal
     governor and make it update total_weight on configuration changes
     after the thermal zone has been registered (Yu-Che Cheng)"

* tag 'thermal-6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: gov_power_allocator: Update total_weight on bind and cdev updates
  thermal/of: Fix cdev lookup in thermal_of_should_bind()
  thermal: gov_power_allocator: Fix incorrect calculation in divvy_up_power()

Merge tag 'pm-6.14-rc5' of git://git./linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Fix the handling of processors that stop the TSC in deeper C-states in
  the intel_idle driver (Thomas Gleixner)"

* tag 'pm-6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  intel_idle: Handle older CPUs, which stop the TSC in deeper C states, correctly

Merge tag 'x86-urgent-2025-02-28' of git://git./linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:

 - Fix conflicts between devicetree and ACPI SMP discovery & setup

 - Fix a warm-boot lockup on AMD SC1100 SoC systems

 - Fix a W=1 build warning related to x86 IRQ trace event setup

 - Fix a kernel-doc warning

* tag 'x86-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry: Fix kernel-doc warning
  x86/irq: Define trace events conditionally
  x86/CPU: Fix warm boot hang regression on AMD SC1100 SoC systems
  x86/of: Don't use DTB for SMP setup if ACPI is enabled

Merge tag 'sched-urgent-2025-02-28' of git://git./linux/kernel/git/tip/tip

Pull scheduler fix from Ingo Molnar:
 "Prevent cond_resched() based preemption when interrupts are disabled,
  on PREEMPT_NONE and PREEMPT_VOLUNTARY kernels"

* tag 'sched-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Prevent rescheduling when interrupts are disabled

Merge tag 'perf-urgent-2025-02-28' of git://git./linux/kernel/git/tip/tip

Pull perf event fixes from Ingo Molnar:
 "Miscellaneous perf events fixes and a minor HW enablement change:

   - Fix missing RCU protection in perf_iterate_ctx()

   - Fix pmu_ctx_list ordering bug

   - Reject the zero page in uprobes

   - Fix a family of bugs related to low frequency sampling

   - Add Intel Arrow Lake U CPUs to the generic Arrow Lake RAPL support
     table

   - Fix a lockdep-assert false positive in uretprobes"

* tag 'perf-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  uprobes: Remove too strict lockdep_assert() condition in hprobe_expire()
  perf/x86/rapl: Add support for Intel Arrow Lake U
  perf/x86/intel: Use better start period for frequency mode
  perf/core: Fix low freq setting via IOC_PERIOD
  perf/x86: Fix low freqency setting issue
  uprobes: Reject the shared zeropage in uprobe_write_opcode()
  perf/core: Order the PMU list to fix warning about unordered pmu_ctx_list
  perf/core: Add RCU read lock protection to perf_iterate_ctx()

Merge tag 'objtool-urgent-2025-02-28' of git://git./linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar:
 "Fix an objtool false positive, and objtool related build warnings that
  happens on PIE-enabled architectures such as LoongArch"

* tag 'objtool-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Add bch2_trans_unlocked_or_in_restart_error() to bcachefs noreturns
  objtool: Fix C jump table annotations for Clang
  vmlinux.lds: Ensure that const vars with relocations are mapped R/O

Merge tag 'locking-urgent-2025-02-28' of git://git./linux/kernel/git/tip/tip

Pull locking fix from Ingo Molnar:
 "Fix an rcuref_put() slowpath race"

* tag 'locking-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcuref: Plug slowpath race in rcuref_put()

Merge tag 'trace-v6.14-rc4' of git://git./linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix crash from bad histogram entry

   An error path in the histogram creation could leave an entry in a
   link list that gets freed. Then when a new entry is added it can
   cause a u-a-f bug. This is fixed by restructuring the code so that
   the histogram is consistent on failure and everything is cleaned up
   appropriately.

 - Fix fprobe self test

   The fprobe self test relies on no function being attached by ftrace.
   BPF programs can attach to functions via ftrace and systemd now does
   so. This causes those functions to appear in the enabled_functions
   list which holds all functions attached by ftrace. The selftest also
   uses that file to see if functions are being connected correctly. It
   counts the functions in the file, but if there's already functions in
   the file, it fails. Instead, add the number of functions in the file
   at the start of the test to all the calculations during the test.

 - Fix potential division by zero of the function profiler stddev

   The calculated divisor that calculates the standard deviation of the
   function times can overflow. If the overflow happens to land on zero,
   that can cause a division by zero. Check for zero from the
   calculation before doing the division.

   TODO: Catch when it ever overflows and report it accordingly. For
   now, just prevent the system from crashing.

* tag 'trace-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Avoid potential division by zero in function_stat_show()
  selftests/ftrace: Let fprobe test consider already enabled functions
  tracing: Fix bad hist from corrupting named_triggers list

Merge tag 'iommu-fixes-v6.14-rc4' of git://git./linux/kernel/git/iommu/linux

Pull iommu fixes from Joerg Roedel:

 - Intel VT-d fixes:
     - Fix suspicious RCU usage splat
     - Fix passthrough for devices under PCIe-PCI bridge

 - AMD-Vi fix:
     - Fix to preserve bits when updating device table entries

* tag 'iommu-fixes-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux:
  iommu/vt-d: Fix suspicious RCU usage
  iommu/vt-d: Remove device comparison in context_setup_pass_through_cb
  iommu/amd: Preserve default DTE fields when updating Host Page Table Root

intel_idle: Handle older CPUs, which stop the TSC in deeper C states, correctly

The Intel idle driver is preferred over the ACPI processor idle driver,
but fails to implement the work around for Core2 generation CPUs, where
the TSC stops in C2 and deeper C-states. This causes stalls and boot
delays, when the clocksource watchdog does not catch the unstable TSC
before the CPU goes deep idle for the first time.

The ACPI driver marks the TSC unstable when it detects that the CPU
supports C2 or deeper and the CPU does not have a non-stop TSC.

Add the equivivalent work around to the Intel idle driver to cure that.

Fixes: 18734958e9bf ("intel_idle: Use ACPI _CST for processor models without C-state tables")
Reported-by: Fab Stz <fabstz-it@yahoo.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Fab Stz <fabstz-it@yahoo.fr>
Cc: All applicable <stable@vger.kernel.org>
Closes: https://lore.kernel.org/all/10cf96aa-1276-4bd4-8966-c890377030c3@yahoo.fr
Link: https://patch.msgid.link/87bjupfy7f.ffs@tglx
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Merge tag 'block-6.14-20250228' of git://git.kernel.dk/linux

Pull block fixes from Jens Axboe:

 - Fix plugging for native zone writes

 - Fix segment limit settings for != 4K page size archs

 - Fix for slab names overflowing

* tag 'block-6.14-20250228' of git://git.kernel.dk/linux:
  block: fix 'kmem_cache of name 'bio-108' already exists'
  block: Remove zone write plugs when handling native zone append writes
  block: make segment size limit workable for > 4K PAGE_SIZE

Merge tag 'io_uring-6.14-20250228' of git://git.kernel.dk/linux

Pull io_uring fix from Jens Axboe:
 "Just a single fix headed for stable, ensuring that msg_control is
  properly saved in compat mode as well"

* tag 'io_uring-6.14-20250228' of git://git.kernel.dk/linux:
  io_uring/net: save msg_control for compat

Merge tag 'efi-fixes-for-v6.14-2' of git://git./linux/kernel/git/efi/efi

Pull EFI fixes from Ard Biesheuvel:
 "Another couple of EFI fixes for v6.14.

  Only James's patch stands out, as it implements a workaround for odd
  behavior in fwupd in user space, which creates EFI variables by
  touching a file in efivarfs, clearing the immutable bit (which gets
  set automatically for $reasons) and then opening it again for writing,
  none of which is really necessary.

  The fwupd author and LVFS maintainer is already rolling out a fix for
  this on the fwupd side, and suggested that the workaround in this PR
  could be backed out again during the next cycle.

  (There is a semantic mismatch in efivarfs where some essential
  variable attributes are stored in the first 4 bytes of the file, and
  so zero length files cannot exist, as they cannot be written back to
  the underlying variable store. So now, they are dropped once the last
  reference is released.)

  Summary:

   - Fix CPER error record parsing bugs

   - Fix a couple of efivarfs issues that were introduced in the merge
     window

   - Fix an issue in the early remapping code of the MOKvar table"

* tag 'efi-fixes-for-v6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi/mokvar-table: Avoid repeated map/unmap of the same page
  efi: Don't map the entire mokvar table to determine its size
  efivarfs: allow creation of zero length files
  efivarfs: Defer PM notifier registration until .fill_super
  efi/cper: Fix cper_arm_ctx_info alignment
  efi/cper: Fix cper_ia_proc_ctx alignment

Merge tag 'i2c-host-fixes-6.14-rc5' of git://git./linux/kernel/git/andi.shyti/linux into i2c/for-current

i2c-host-fixes for v6.14-rc5

- npcm fixes interrupt initialization sequence.
- ls2x fixes frequency setting.
- amd-asf re-enables interrupts properly at irq handler's exit.

gpiolib: Fix Oops in gpiod_direction_input_nonotify()

The gpiod_direction_input_nonotify() function is supposed to return zero
if the direction for the pin is input.  But instead it accidentally
returns GPIO_LINE_DIRECTION_IN (1) which will be cast into an ERR_PTR()
in gpiochip_request_own_desc().  The callers dereference it and it leads
to a crash.

I changed gpiod_direction_output_raw_commit() just for consistency but
returning GPIO_LINE_DIRECTION_OUT (0) is fine.

Cc: stable@vger.kernel.org
Fixes: 9d846b1aebbe ("gpiolib: check the return value of gpio_chip::get_direction()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/254f3925-3015-4c9d-aac5-bb9b4b2cd2c5@stanley.mountain
[Bartosz: moved the variable declarations to the top of the functions]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>