Make `Arc::into_unique_or_drop` to become a mere associated function
instead of a method (i.e. removing the `self` receiver).
It's a general convention for Rust smart pointers to avoid having
methods defined on them, because if the pointee type has a method of the
same name, then it is shadowed. This is normally for avoiding semver
breakage, which isn't an issue for kernel codebase, but it's still
generally a good practice to follow this rule, so that `ptr.foo()` would
always be calling a method on the pointee type.
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/r/20250723233312.3304339-3-gary@kernel.org
Memory barriers are building blocks for concurrent code, hence provide
a minimal set of them.
The compiler barrier, barrier(), is implemented in inline asm instead of
using core::sync::atomic::compiler_fence() because memory models are
different: kernel's atomics are implemented in inline asm therefore the
compiler barrier should be implemented in inline asm as well. Also it's
currently only public to the kernel crate until there's a reasonable
driver usage.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-10-boqun.feng@gmail.com/
Add generic atomic support for `usize` and `isize`. Note that instead of
mapping directly to `atomic_long_t`, the represention type
(`AtomicType::Repr`) is selected based on CONFIG_64BIT. This reduces
the necessity of creating `atomic_long_*` helpers, which could save
the binary size of kernel if inline helpers are not available. To do so,
an internal type `isize_atomic_repr` is defined, it's `i32` in 32bit
kernel and `i64` in 64bit kernel.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-9-boqun.feng@gmail.com/
One important set of atomic operations is the arithmetic operations,
i.e. add(), sub(), fetch_add(), add_return(), etc. However it may not
make senses for all the types that `AtomicType` to have arithmetic
operations, for example a `Foo(u32)` may not have a reasonable add() or
sub(), plus subword types (`u8` and `u16`) currently don't have
atomic arithmetic operations even on C side and might not have them in
the future in Rust (because they are usually suboptimal on a few
architecures). Therefore the plan is to add a few subtraits of
`AtomicType` describing which types have and can do atomic arithemtic
operations.
One trait `AtomicAdd` is added, and only add() and fetch_add() are
added. The rest will be added in the future.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-7-boqun.feng@gmail.com/
Preparation for atomic primitives. Instead of a suffix like _acquire, a
method parameter along with the corresponding generic parameter will be
used to specify the ordering of an atomic operations. For example,
atomic load() can be defined as:
impl<T: ...> Atomic<T> {
pub fn load<O: AcquireOrRelaxed>(&self, _o: O) -> T { ... }
}
and acquire users would do:
let r = x.load(Acquire);
relaxed users:
let r = x.load(Relaxed);
doing the following:
let r = x.load(Release);
will cause a compiler error.
Compared to suffixes, it's easier to tell what ordering variants an
operation has, and it also make it easier to unify the implementation of
all ordering variants in one method via generic. The `TYPE` associate
const is for generic function to pick up the particular implementation
specified by an ordering annotation.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-4-boqun.feng@gmail.com/
Preparation for generic atomic implementation. To unify the
implementation of a generic method over `i32` and `i64`, the C side
atomic methods need to be grouped so that in a generic method, they can
be referred as <type>::<method>, otherwise their parameters and return
value are different between `i32` and `i64`, which would require using
`transmute()` to unify the type into a `T`.
Introduce `AtomicImpl` to represent a basic type in Rust that has the
direct mapping to an atomic implementation from C. Use a sealed trait to
restrict `AtomicImpl` to only support `i32` and `i64` for now.
Further, different methods are put into different `*Ops` trait groups,
and this is for the future when smaller types like `i8`/`i16` are
supported but only with a limited set of API (e.g. only set(), load(),
xchg() and cmpxchg(), no add() or sub() etc).
While the atomic mod is introduced, documentation is also added for
memory models and data races.
Also bump my role to the maintainer of ATOMIC INFRASTRUCTURE to reflect
my responsibility on the Rust atomic mod.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-3-boqun.feng@gmail.com/
Commit 07dad44aa9 ("rust: kernel: move ARef and AlwaysRefCounted to
sync::aref") moved `ARef` and `AlwaysRefCounted` into their own module.
In that process only a short, single line description of the module was
added. Extend the description by explaining what is meant by "internal
reference counting", the two items in the trait & the difference to
`Arc`.
Signed-off-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When building the kernel using llvm-20.1.7-rust-1.89.0-x86_64,
this symbol is generated:
$ llvm-nm --demangle vmlinux | grep CpuId
ffffffff84c77450 T <kernel::cpu::CpuId>::current
However, this Rust symbol is a trivial wrapper around
`raw_smp_processor_id` function. It doesn't make sense
to go through a trivial wrapper for such functions,
so mark it inline.
After applying this patch, the above command will produce no output.
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1145
Signed-off-by: Ritvik Gupta <ritvikfoss@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull driver core fixes from Danilo Krummrich:
- Fix UAF in cgroup pressure polling by using kernfs_get_active_of()
to prevent operations on released file descriptors
- Fix unresolved intra-doc link in the documentation of struct Device
when CONFIG_DRM != y
- Update the DMA Rust MAINTAINERS entry
* tag 'driver-core-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
MAINTAINERS: Update the DMA Rust entry
kernfs: Fix UAF in polling when open file is released
rust: device: fix unresolved link to drm::Device
pin-init changes for v6.18
Changed:
- `#[pin_data]` now generates a `*Projection` struct similar to the
`pin-project` crate.
- Add initializer code blocks to `[try_][pin_]init!` macros: make
initializer macros accept any number of `_: {/* arbitrary code */},` &
make them run the code at that point.
- Make the `[try_][pin_]init!` macros expose initialized fields via a
`let` binding as `&mut T` or `Pin<&mut T>` for later fields.
Upstream dev news:
- Released v0.0.10 before the changes included in this tag.
- Inform users of the impending rename from `pinned-init` to `pin-init`
(in the kernel the rename already happened).
- More CI improvements.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
From: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250912174148.373530-1-lossin@kernel.org
Cross-merge networking fixes after downstream PR (net-6.17-rc6).
Conflicts:
net/netfilter/nft_set_pipapo.c
net/netfilter/nft_set_pipapo_avx2.c
c4eaca2e10 ("netfilter: nft_set_pipapo: don't check genbit from packetpath lookups")
84c1da7b38 ("netfilter: nft_set_pipapo: use avx2 algorithm for insertions too")
Only trivial adjacent changes (in a doc and a Makefile).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch introduces the DMA_ATTR_MMIO attribute to mark DMA buffers
that reside in memory-mapped I/O (MMIO) regions, such as device BARs
exposed through the host bridge, which are accessible for peer-to-peer
(P2P) DMA.
This attribute is especially useful for exporting device memory to other
devices for DMA without CPU involvement, and avoids unnecessary or
potentially detrimental CPU cache maintenance calls.
DMA_ATTR_MMIO is supposed to provide dma_map_resource() functionality
without need to call to special function and perform branching when
processing generic containers like bio_vec by the callers.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/6f058ec395c5348014860dbc2eed348c17975843.1757423202.git.leonro@nvidia.com
After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
[ Applied fixes to devres and rust_driver_pci sample - Benno]
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Benno Lossin <lossin@kernel.org>
Make the `#[pin_data]` macro generate a `*Projection` struct that holds
either `Pin<&mut Field>` or `&mut Field` for every field of the original
struct. Which version is chosen depends on weather there is a `#[pin]`
or not respectively. Access to this projected version is enabled through
generating `fn project(self: Pin<&mut Self>) -> SelfProjection<'_>`.
[ Adapt workqueue to use the new projection instead of its own, custom
one - Benno ]
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Benno Lossin <lossin@kernel.org>
A lot of drivers only care about enabling the regulator for as long as
the underlying Device is bound. This can be easily observed due to the
extensive use of `devm_regulator_get_enable` and
`devm_regulator_get_enable_optional` throughout the kernel.
Therefore, make this helper available in Rust. Also add an example
noting how it should be the default API unless the driver needs more
fine-grained control over the regulator.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20250910-regulator-remove-dynamic-v3-2-07af4dfa97cc@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Introduces the concept of a `ScopedDir`, which allows for the creation
of debugfs directories and files that are tied to the lifetime of a
particular data structure. This ensures that debugfs entries do not
outlive the data they refer to.
The new `Dir::scope` method creates a new directory that is owned by a
`Scope` handle. All files and subdirectories created within this scope
are automatically cleaned up when the `Scope` is dropped.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250904-debugfs-rust-v11-6-7d12a165685a@google.com
[ Fix up Result<(), Error> -> Result; fix spurious backtick in
doc-comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extends the `debugfs` API to support creating files with content
generated and updated by callbacks. This is done via the
`read_callback_file`, `write_callback_file`, and
`read_write_callback_file` methods.
These methods allow for more flexible file definition, either because
the type already has a `Writer` or `Reader` method that doesn't
do what you'd like, or because you cannot implement it (e.g. because
it's a type defined in another crate or a primitive type).
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250904-debugfs-rust-v11-4-7d12a165685a@google.com
[ Fix up Result<(), Error> -> Result. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Extends the `debugfs` API to support creating read-only files. This
is done via the `Dir::read_only_file` method, which takes a data object
that implements the `Writer` trait.
The file's content is generated by the `Writer` implementation, and the
file is automatically removed when the returned `File` handle is
dropped.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250904-debugfs-rust-v11-2-7d12a165685a@google.com
[ Fixup build failure when CONFIG_DEBUGFS=n. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
We need the DRM Rust changes that went into drm-misc before the
existence of the drm-rust tree in here as well.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Core functions like `to_result` should have good documentation.
Thus improve it, including adding an example of how to perform early
returns with it.
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This constructor is public since commit 5ed1474734 ("rust: error:
make conversion functions public"), and we will refer to it from the
documentation of `to_result` in a later commit.
Thus improve its documentation, including adding examples.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now that my rust skills have been honed, I noticed that there's a lot of
generics in our gem bindings that don't actually need to be here. Currently
the hierarchy of traits in our gem bindings looks like this:
* Drivers implement:
* BaseDriverObject<T: DriverObject> (has the callbacks)
* DriverObject (has the drm::Driver type)
* Crate implements:
* IntoGEMObject for Object<T> where T: DriverObject
Handles conversion to/from raw object pointers
* BaseObject for T where T: IntoGEMObject
Provides methods common to all gem interfaces
Also of note, this leaves us with two different drm::Driver associated
types:
* DriverObject::Driver
* IntoGEMObject::Driver
I'm not entirely sure of the original intent here unfortunately (if anyone
is, please let me know!), but my guess is that the idea would be that some
objects can implement IntoGEMObject using a different ::Driver than
DriverObject - presumably to enable the usage of gem objects from different
drivers. A reasonable usecase of course.
However - if I'm not mistaken, I don't think that this is actually how
things would go in practice. Driver implementations are of course
implemented by their associated drivers, and generally drivers are not
linked to each-other when building the kernel. Which is to say that even in
a situation where we would theoretically deal with gem objects from another
driver, we still wouldn't have access to its drm::driver::Driver
implementation. It's more likely we would simply want a variant of gem
objects in such a situation that have no association with a
drm::driver::Driver type.
Taking that into consideration, we can assume the following:
* Anything that implements BaseDriverObject will implement DriverObject
In other words, all BaseDriverObjects indirectly have an associated
::Driver type - so the two traits can be combined into one with no
generics.
* Not everything that implements IntoGEMObject will have an associated
::Driver, and that's OK.
And with this, we now can do quite a bit of cleanup with the use of
generics here. As such, this commit:
* Removes the generics on BaseDriverObject
* Moves DriverObject::Driver into BaseDriverObject
* Removes DriverObject
* Removes IntoGEMObject::Driver
* Add AllocImpl::Driver, which we can use as a binding to figure out the
correct File type for BaseObject
Leaving us with a simpler trait hierarchy that now looks like this:
* Drivers implement: BaseDriverObject
* Crate implements:
* IntoGEMObject for Object<T> where T: DriverObject
* BaseObject for T where T: IntoGEMObject
Which makes the code a lot easier to understand and build on :).
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250908185239.135849-2-lyude@redhat.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
All types in `bindings` implement `Zeroable` if they can, so use
`pin_init::zeroed` instead of relying on `unsafe` code.
If this ends up not compiling in the future, something in bindgen or on
the C side changed and is most likely incorrect.
Signed-off-by: Benno Lossin <lossin@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The error codes come from several headers.
Thus, add the other header links.
Signed-off-by: Onur Özkan <work@onurozkan.dev>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
[ Sorted headers. Added line breaks. Reworded commit message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This `srctree/` link pointed to a file with an underscore, but the header
used a dash instead.
Thus fix it.
This cleans a future warning that will check our `srctree/` links.
Cc: stable@vger.kernel.org
Fixes: 3253aba340 ("rust: block: introduce `kernel::block::mq` module")
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull alloc and DMA updates from Danilo Krummrich:
Allocator:
- Provide information about the minimum alignment guarantees of
'Kmalloc', 'Vmalloc' and 'KVmalloc'.
- Take minimum alignment guarantees of allocators for
'ForeignOwnable' into account.
- Remove the 'allocator_test' incl. 'Cmalloc'.
Box:
- Implement 'Box::pin_slice()', which constructs a pinned slice of
elements.
Vec:
- Simplify KUnit test module name to 'rust_kvec'.
- Add doc-test for 'Vec::as_slice()'.
- Constify various methods.
DMA:
- Update 'ARef' and 'AlwaysRefCounted' imports.
MISC:
- Remove support for unused host '#[test]'s.
- Constify 'ArrayLayout::new_unchecked()'.
* tag 'alloc-next-v6.18-2025-09-04' of https://github.com/Rust-for-Linux/linux:
rust: alloc: remove `allocator_test`
rust: kernel: remove support for unused host `#[test]`s
rust: alloc: implement Box::pin_slice()
rust: alloc: add ARCH_KMALLOC_MINALIGN to bindgen blocklist
rust: dma: Update ARef and AlwaysRefCounted imports from sync::aref
rust: alloc: take the allocator into account for FOREIGN_ALIGN
rust: alloc: specify the minimum alignment of each allocator
rust: make `kvec::Vec` functions `const fn`
rust: make `ArrayLayout::new_unchecked` a `const fn`
rust: alloc: kvec: simplify KUnit test module name to "rust_kvec"
rust: alloc: kvec: add doc example for as_slice method
Pull rust fixes from Miguel Ojeda:
- Two changes to prepare for the future Rust 1.91.0 release (expected
2025-10-30, currently in nightly): a target specification format
change and a renamed, soon-to-be-stabilized 'core' function.
* tag 'rust-fixes-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: support Rust >= 1.91.0 target spec
rust: use the new name Location::file_as_c_str() in Rust >= 1.91.0
Alice Ryhl <aliceryhl@google.com> says:
This series adds support for the `struct iov_iter` type. This type
represents an IO buffer for reading or writing, and can be configured
for either direction of communication.
In Rust, we define separate types for reading and writing. This will
ensure that you cannot mix them up and e.g. call copy_from_iter in a
read_iter syscall.
To use the new abstractions, miscdevices are given new methods read_iter
and write_iter that can be used to implement the read/write syscalls on
a miscdevice. The miscdevice sample is updated to provide read/write
operations.
Intended for Greg's miscdevice tree.
Link: https://lore.kernel.org/r/20250822-iov-iter-v5-0-6ce4819c2977@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds abstractions for the iov_iter type in the case where
data_source is ITER_DEST. This will make Rust implementations of
fops->read_iter possible.
This series only has support for using existing IO vectors created by C
code. Additional abstractions will be needed to support the creation of
IO vectors in Rust code.
These abstractions make the assumption that `struct iov_iter` does not
have internal self-references, which implies that it is valid to move it
between different local variables.
This patch adds an IovIterDest struct that is very similar to the
IovIterSource from the previous patch. However, as the methods on the
two structs have very little overlap (just getting the length and
advance/revert), I do not think it is worth it to try and deduplicate
this logic.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250822-iov-iter-v5-2-6ce4819c2977@google.com
Gary Guo
Boqun Feng
Greg Kroah-Hartman
Benno Lossin
Ritvik Gupta
Shankari Anand
Hui Zhu
Vitaly Wool
Linus Torvalds
Danilo Krummrich
Jakub Kicinski
Leon Romanovsky
Daniel Almeida
Matthew Maurer
Miguel Ojeda
Lyude Paul
Onur Özkan
Alice Ryhl