`from_expr` relies on `build_assert` to infer that the passed expression
fits the type's boundaries at build time. That inference can only be
successful its code (and that of `fits_within`, which performs the
check) is inlined, as a dedicated function would need to work with a
variable and cannot verify that property.
While inlining happens as expected in most cases, it is not guaranteed.
In particular, kernel options that optimize for size like
`CONFIG_CC_OPTIMIZE_FOR_SIZE` can result in `from_expr` not being
inlined.
Add `#[inline(always)]` attributes to both `fits_within` and `from_expr`
to make the compiler inline these functions more aggressively, as it
does not make sense to use them non-inlined anyway.
[ For reference, the errors look like:
ld.lld: error: undefined symbol: rust_build_error
>>> referenced by build_assert.rs:83 (rust/kernel/build_assert.rs:83)
>>> rust/doctests_kernel_generated.o:(<kernel::num::bounded::Bounded<u8, 1>>::from_expr) in archive vmlinux.a
- Miguel ]
Fixes: 01e345e82e ("rust: num: add Bounded integer wrapping type")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511210055.RUsFNku1-lkp@intel.com/
Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20251122-bounded_ints_fix-v1-1-1e07589d4955@nvidia.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The rust-next tree contains commit:
3b83f5d5e7 ("rust: replace `CStr` with `core::ffi::CStr`")
which, when merged together with commits:
57c5bd9aee ("rust: i2c: add basic I2C device and driver abstractions")
f3cc26a417 ("rust: i2c: add manual I2C device creation abstractions")
from this tree (driver-core), produces errors like the following:
error[E0599]: no method named `len_with_nul` found for reference `&'static ffi::CStr` in the current scope
--> rust/kernel/i2c.rs:48:16
|
48 | id.len_with_nul() <= Self::I2C_NAME_SIZE,
| ^^^^^^^^^^^^ method not found in `&CStr`
error[E0599]: no method named `as_bytes_with_nul` found for reference `&'static ffi::CStr` in the current scope
--> rust/kernel/i2c.rs:51:22
|
51 | let src = id.as_bytes_with_nul();
| ^^^^^^^^^^^^^^^^^
|
help: there is a method `to_bytes_with_nul` with a similar name
|
51 | let src = id.to_bytes_with_nul();
| ~~~~~~~~~~~~~~~~~
which were detected in linux-next by Stephen [1].
The `i2c` code can be independently prepared to be ready for the change,
thus do so.
The change is similar to the one done by Tamir in commit 657403637f
("rust: acpi: use `core::ffi::CStr` method names").
Link: https://lore.kernel.org/all/20251120181111.65ce75a0@canb.auug.org.au/ [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20251123163536.1771801-1-ojeda@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In older versions of Rust, the compiler doesn't know about the newer
`as_flattened*` methods, thus `rustdoc` complains about the intra-doc
links, e.g.
error: unresolved link to `slice::as_flattened`
--> rust/kernel/slice.rs:19:23
|
19 | /// [`as_flattened`]: slice::as_flattened
| ^^^^^^^^^^^^^^^^^^^ the primitive type `slice` has no associated item named `as_flattened`
|
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`
Thus fix them by using an URL instead.
Fixes: 88622323dd ("rust: enable slice_flatten feature and provide it through an extension trait")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251119185125.1411151-1-ojeda@kernel.org
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Rust 1.92.0 warns when building the documentation that [`PinnedDrop`] is
an invalid reference. This is correct and it's weird that it didn't warn
before, so fix the link.
[ The reason is that it is hidden -- I had asked about that in the
upstream PR that changed the behavior because I wasn't sure it was
intentional (and thus whether we needed to fix this and other cases):
https://github.com/rust-lang/rust/pull/147153#issuecomment-3395484636
It turns out it was not, and it has been fixed for 1.92.0's upcoming
release thanks to Guillaume and León. So we do not strictly need
this patch and the other changes anymore:
https://github.com/rust-lang/rust/pull/147809
However, checking hidden/private items or, even better, a runtime
toggle to be able to see those on the fly, is something that I think
would be quite nice so I have had it in our usual lists for a while.
Guillaume is open to the idea and perhaps experimenting with an
implementation on our side first -- he asked me to open issues
upstream:
https://github.com/rust-lang/rust/issues/149105https://github.com/rust-lang/rust/issues/149106
- Miguel ]
Signed-off-by: Benno Lossin <lossin@kernel.org>
Link: https://patch.msgid.link/20251016211740.653599-1-lossin@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add the `Bounded` integer wrapper type, which restricts the number of
bits allowed to represent of value.
This is useful to e.g. enforce guarantees when working with bitfields
that have an arbitrary number of bits.
Alongside this type, provide many `From` and `TryFrom` implementations
are to reduce friction when using with regular integer types. Proxy
implementations of common integer operations are also provided.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251108-bounded_ints-v4-2-c9342ac7ebd1@nvidia.com
[ Added intra-doc link. Fixed a few other nits. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Implement the `AsBusDevice` trait for converting a `Device` reference to a
bus device reference for all bus devices.
The `AsBusDevice` trait allows abstractions to provide the bus device in
class device callbacks. It must not be used by drivers and is intended for
bus and class device abstractions only.
Signed-off-by: Markus Probst <markus.probst@posteo.de>
Link: https://patch.msgid.link/20251027200547.1038967-2-markus.probst@posteo.de
[ * Remove unused import.
* Change visibility of AsBusDevice to public.
* Fix build for USB.
* Add impl for I2cClient.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
In addition to the basic I2C device support, add rust abstractions
upon `i2c_new_client_device`/`i2c_unregister_device` C functions.
Implement the core abstractions needed for manual creation/deletion
of I2C devices, including:
* `i2c::Registration` — a NonNull pointer created by the function
`i2c_new_client_device`
* `i2c::I2cAdapter` — a ref counted wrapper around `struct i2c_adapter`
* `i2c::I2cBoardInfo` — a safe wrapper around `struct i2c_board_info`
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162154.171493-1-igor.korotin.linux@gmail.com
[ Remove unnecessary safety comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Sometimes we may need to iterate over, or find an element in a read
only (or read mostly) red-black tree, and in that case we don't need a
mutable reference to the tree, which we'll however have to take to be
able to use the current (mutable) cursor implementation.
This patch adds a simple immutable cursor implementation to RBTree,
which enables us to use an immutable tree reference. The existing
(fully featured) cursor implementation is renamed to CursorMut,
while retaining its functionality.
The only existing user of the [mutable] cursor for RBTrees (binder) is
updated to match the changes.
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251014123339.2492210-1-vitaly.wool@konsulko.se
[ Applied `rustfmt`. Added intra-doc link. Fixed unclosed example.
Fixed docs description. Fixed typo and other formatting nits.
- Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In Rust 1.80, the previously unstable `slice::flatten` family of methods
have been stabilized and renamed to `slice::as_flattened`.
This creates an issue as we want to use `as_flattened`, but need to
support the MSRV (which at the moment is Rust 1.78) where it is named
`flatten`.
Solve this by enabling the `slice_flatten` feature, and providing an
`as_flattened` implementation through an extension trait for compiler
versions where it is not available.
The trait is then exported from the prelude, making the `as_flattened`
family of methods transparently available for all supported compiler
versions.
This extension trait can be removed once the MSRV passes 1.80.
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/all/CANiq72kK4pG=O35NwxPNoTO17oRcg1yfGcvr3==Fi4edr+sfmw@mail.gmail.com/
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251110-gsp_boot-v9-8-8ae4058e3c0e@nvidia.com>
Message-ID: <20251104-b4-as-flattened-v3-1-6cb9c26b45cd@nvidia.com>
`rustdoc` reports a broken intra-doc link:
error: unresolved link to `Devres::register`
--> rust/kernel/pwm.rs:722:11
|
722 | /// via [`Devres::register`]. This ties the lifetime of the PWM chip registration
| ^^^^^^^^^^^^^^^^ no item named `Devres` in scope
|
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`
Thus fix it.
Fixes: d8046cd508 ("rust: pwm: Add complete abstraction layer")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20251029181940.780629-1-ojeda@kernel.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Resource sizes are a general concept for dealing with physical
addresses, and not specific to the Resource type, which is just one way
to access physical addresses. Thus, move the typedef to the io module.
Still keep a re-export under resource. This avoids this commit from
being a flag-day, but I also think it's a useful re-export in general so
that you can import
use kernel::io::resource::{Resource, ResourceSize};
instead of having to write
use kernel::io::{
resource::Resource,
ResourceSize,
};
in the specific cases where you need ResourceSize because you are using
the Resource type. Therefore I think it makes sense to keep this
re-export indefinitely and it is *not* intended as a temporary re-export
for migration purposes.
Cc: stable@vger.kernel.org # for v6.18 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-2-538307384f82@google.com
Link: https://lore.kernel.org/all/20251112-resource-phys-typedefs-v2-0-538307384f82@google.com/ [1]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Using start_ptr() and start_ptr_mut() has the advantage that we inherit
the requirements the a mutable or immutable reference from those
methods.
Hence, use them instead of self.cpu_addr.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103190655.2326191-1-dakr@kernel.org
[ Keep using self.cpu_addr in item_from_index(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
It's used to work around an objtool issue since commit abb2a55722
("LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference"), but
it's then passed to bindgen and cause an error because Clang does not
have this option.
Fixes: abb2a55722 ("LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference")
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Mingcong Bai <jeffbai@aosc.io>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
These were introduced and used in an earlier revision of the patch that
became commit fb3957af9ec6 ("pwm: Add Rust driver for T-HEAD TH1520
SoC"). The variant that was actually applied sticks to the modern
waveform abstraction only (and other drivers are supposed to do that,
too), so they can be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20251025122359.361372-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Rust PWM drivers using the abstractions in `kernel/pwm.rs` typically
call C functions (like `pwmchip_alloc`, `__pwmchip_add`, etc.) that are
exported to the `PWM` C symbol namespace.
With the introduction of `imports_ns` support in the `module!` macro,
every PWM driver would need to manually include `imports_ns: ["PWM"]` in
its module declaration.
To simplify this for driver authors and ensure consistency, introduce a
new helper macro `module_pwm_platform_driver!` in `pwm.rs`. This macro
wraps the standard `module_platform_driver!`, forwards all user provided
arguments using the `($($user_args:tt)*)` pattern, and automatically
injects the `imports_ns: ["PWM"]` declaration.
This follows the pattern used in other subsystems (e.g.,
`module_pci_driver!`) to provide specialized module registration
helpers. It makes writing PWM drivers slightly simpler and less error
prone regarding namespace imports.
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://patch.msgid.link/20251028-pwm_fixes-v1-2-25a532d31998@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Introduce a comprehensive abstraction layer for the PWM subsystem to
enable writing drivers in Rust.
Because `Device`, `Chip`, and `PwmOps` all refer to each other, they
form a single, indivisible unit with circular dependencies. They are
introduced together in this single commit to create a complete,
compilable abstraction layer.
The main components are:
- Data Wrappers: Safe, idiomatic wrappers for core C types like
`pwm_device`, and `pwm_chip`.
- PwmOps Trait: An interface that drivers can implement to provide
their hardware-specific logic, mirroring the C `pwm_ops` interface.
- FFI VTable and Adapter: A bridge to connect the high-level PwmOps trait
to the C kernel's pwm_ops vtable.
- Allocation and Lifetime Management: A high-level `Chip::new()`
API to safely allocate a chip and a `Registration` guard that integrates
with `devres` to manage the chip's registration with the PWM core.
An `AlwaysRefCounted` implementation and a custom release handler
prevent memory leaks by managing the chip's lifetime and freeing
driver data correctly.
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20251016-rust-next-pwm-working-fan-for-sending-v16-3-a5df2405d2bd@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Introduce the foundational support for PWM abstractions in Rust.
This commit adds the `RUST_PWM_ABSTRACTIONS` Kconfig option to enable
the feature, along with the necessary build-system support and C
helpers.
It also introduces the first set of safe wrappers for the PWM
subsystem, covering the basic data carrying C structs and enums:
- `Polarity`: A safe wrapper for `enum pwm_polarity`.
- `Waveform`: A wrapper for `struct pwm_waveform`.
- `State`: A wrapper for `struct pwm_state`.
These types provide memory safe, idiomatic Rust representations of the
core PWM data structures and form the building blocks for the
abstractions that will follow.
Tested-by: Drew Fustini <fustini@kernel.org>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20251016-rust-next-pwm-working-fan-for-sending-v16-2-a5df2405d2bd@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Kernel modules that use C symbols exported via `EXPORT_SYMBOL_NS` must
declare this dependency for `modpost` verification. C modules achieve
this by using the `MODULE_IMPORT_NS(NAMESPACE)` macro, which embeds an
`import_ns=<NAMESPACE>` tag into the `.modinfo` section.
The Rust `module!` macro lacked the ability to generate these tags,
resulting in build warnings for Rust drivers (like the PWM driver) that
call namespaced C functions.
Modify the `module!` macro's internal parser (`ModuleInfo`) to accept a
new optional field `imports_ns`, which takes an array of namespace
strings. Update the code generator (`ModInfoBuilder::emit`) loop to
iterate over these strings and emit the corresponding
`import_ns=<NAMESPACE>` tags into the `.modinfo` section using the
existing `#[link_section]` mechanism.
This provides the necessary infrastructure for Rust modules to correctly
declare their C namespace dependencies.
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Acked-by: Daniel Gomez <da.gomez@samsung.com>
Link: https://patch.msgid.link/20251028-pwm_fixes-v1-1-25a532d31998@samsung.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Currently request_irq_by_index() returns
Result<impl PinInit<irq::Registration<T>, Error> + 'a>
which may carry an error in the Result or the initializer; the same is
true for the other IRQ methods.
Use pin_init::pin_init_scope() to get rid of this redundancy.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103203053.2348783-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently request_irq() returns
Result<impl PinInit<irq::Registration<T>, Error> + 'a>
which may carry an error in the Result or the initializer; the same is
true for request_threaded_irq().
Use pin_init::pin_init_scope() to get rid of this redundancy.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103203053.2348783-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
The `from_bytes*` family of functions expect a slice of the exact same
size as the requested type. This can be sometimes cumbersome for callers
that deal with dynamic stream of data that needs to be manually cut
before each invocation of `from_bytes`.
To simplify such callers, introduce a new `from_bytes*_prefix` family of
methods, which split the input slice at the index required for the
equivalent `from_bytes` method to succeed, and return its result
alongside with the remainder of the slice.
This design is inspired by zerocopy's `try_*_from_prefix` family of
methods.
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251029-nova-vbios-frombytes-v1-1-ac441ebc1de3@nvidia.com>
Message-ID: <20251101-b4-frombytes-prefix-v1-1-0d9c1fd63b34@nvidia.com>
Some older (yet supported) versions of clippy throw a false positive
warning for missing a safety comment when the safety comment is on a
multiline statement.
warning: unsafe block missing a safety comment
--> rust/kernel/auxiliary.rs:351:22
|
351 | Self(unsafe { NonNull::new_unchecked(adev) }),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: consider adding a safety comment on the preceding line
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
= note: requested on the command line with `-W clippy::undocumented-unsafe-blocks`
warning: 1 warning emitted
Fix this by placing the safety comment right on top of the same line
introducing the unsafe block.
Fixes: e4e679c860 ("rust: auxiliary: unregister on parent device unbind")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20251103203932.2361660-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add support for creating binary debugfs files via ScopedDir. This
mirrors the existing functionality for Dir, but without producing an
owning handle -- files are automatically removed when the associated
Scope is dropped.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extend Rust debugfs binary support to allow exposing data stored in
common smart pointers and heap-allocated collections.
- Implement BinaryWriter for Box<T>, Pin<Box<T>>, Arc<T>, and Vec<T>.
- Introduce BinaryReaderMut for mutable binary access with outer locks.
- Implement BinaryReaderMut for Box<T>, Vec<T>, and base types.
- Update BinaryReader to delegate to BinaryReaderMut for Mutex<T>,
Box<T>, Pin<Box<T>> and Arc<T>.
This enables debugfs files to directly expose or update data stored
inside heap-allocated, reference-counted, or lock-protected containers
without manual dereferencing or locking.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Introduce support for read-only, write-only, and read-write binary files
in Rust debugfs. This adds:
- BinaryWriter and BinaryReader traits for writing to and reading from
user slices in binary form.
- New Dir methods: read_binary_file(), write_binary_file(),
`read_write_binary_file`.
- Corresponding FileOps implementations: BinaryReadFile,
BinaryWriteFile, BinaryReadWriteFile.
This allows kernel modules to expose arbitrary binary data through
debugfs, with proper support for offsets and partial reads/writes.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
