Add UserSliceWriter::write_dma() to copy data from a Coherent<[u8]> to
userspace. This provides a safe interface for copying DMA buffer
contents to userspace without requiring callers to work with raw
pointers.
Because write_dma() and write_slice() have common code, factor that code
out into a helper function, write_raw().
The method handles bounds checking and offset calculation internally,
wrapping the unsafe copy_to_user() call.
Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260319212658.2541610-3-ttabi@nvidia.com
[ Rebase onto Coherent<T> changes; remove unnecessary turbofish from
cast(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Analogous to Coherent::zeroed() and Coherent::zeroed_with_attrs(), add
Coherent:init() and Coherent::init_with_attrs() which both take an impl
Init<T, E> argument initializing the DMA coherent memory.
Compared to CoherentInit, Coherent::init() is a one-shot constructor
that runs an Init closure and immediately exposes the DMA handle,
whereas CoherentInit is a multi-stage initializer that provides safe
&mut T access by withholding the DMA address until converted to
Coherent.
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260320194626.36263-6-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently, dma::Coherent cannot safely provide (mutable) access to its
underlying memory because the memory might be concurrently accessed by a
DMA device. This makes it difficult to safely initialize the memory
before handing it over to the hardware.
Introduce dma::CoherentBox, a type that encapsulates a dma::Coherent
before its DMA address is exposed to the device. dma::CoherentBox can
guarantee exclusive access to the inner dma::Coherent and implement
Deref and DerefMut.
Once the memory is properly initialized, dma::CoherentBox can be
converted into a regular dma::Coherent.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260320194626.36263-5-dakr@kernel.org
[ Remove unnecessary trait bounds. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
These constructors create a coherent container of a single object
instead of slice. They are named `zeroed` and `zeroed_with_attrs` to
emphasis that they are created initialized zeroed. It is intended that
there'll be new constructors that take `PinInit` instead of zeroing.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260320194626.36263-4-dakr@kernel.org
[ Use kernel import style. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently, `CoherentAllocation` is concecptually a DMA coherent container
of a slice of `[T]` of runtime-checked length. Generalize it by creating
`dma::Coherent<T>` which can hold any value of `T`.
`Coherent::alloc_with_attrs` is implemented but not yet exposed, as I
believe we should not expose the way to obtain an uninitialized coherent
region.
`Coherent<[T]>` provides a `len` method instead of the previous `count()`
method to be consistent with methods on slices.
The existing type is re-defined as a type alias of `Coherent<[T]>` to ease
transition. Methods in use are not yet removed.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260320194626.36263-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add safe Rust abstractions over the Linux kernel's GPU buddy
allocator for physical memory management. The GPU buddy allocator
implements a binary buddy system useful for GPU physical memory
allocation. nova-core will use it for physical memory allocation.
Cc: Nikola Djukic <ndjukic@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260320045711.43494-2-joelagnelf@nvidia.com
[ * Use doc-comments for GpuBuddyAllocMode methods and GpuBuddyGuard,
* Fix comma splice in GpuBuddyParams::chunk_size doc-comment,
* Remove redundant summary in GpuBuddy::new doc-comment,
* Drop Rust helper for gpu_buddy_block_size().
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Register abstraction and I/O infrastructure improvements
Introduce the register!() macro to define type-safe I/O register
accesses. Refactor the IoCapable trait into a functional trait, which
simplifies I/O backends and removes the need for overloaded Io methods.
This is a stable tag for other trees to merge.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Some I/O types, like fixed address registers, carry their location
alongside their values. For these types, the regular `Io::write` method
can lead into repeating the location information twice: once to provide
the location itself, another time to build the value.
We are also considering supporting making all register values carry
their full location information for convenience and safety.
Add a new `Io::write_reg` method that takes a single argument
implementing `LocatedRegister`, a trait that decomposes implementors
into a `(location, value)` tuple. This allows write operations on fixed
offset registers to be done while specifying their name only once.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/all/DH0XBLXZD81K.22SWIZ1ZAOW1@kernel.org/
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260314-register-v9-8-86805b2f7e9d@nvidia.com
[ Replace FIFO with VERSION register in the examples. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a macro for defining hardware register types with I/O accessors.
Each register field is represented as a `Bounded` of the appropriate bit
width, ensuring field values are never silently truncated.
Fields can optionally be converted to/from custom types, either fallibly
or infallibly.
The address of registers can be direct, relative, or indexed, supporting
most of the patterns in which registers are arranged.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/all/20250306222336.23482-6-dakr@kernel.org/
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260314-register-v9-7-86805b2f7e9d@nvidia.com
[ * Improve wording and formatting of doc-comments,
* Import build_assert!(),
* Add missing inline annotations,
* Call static_assert!() with absolute path,
* Use expect instead of allow.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
By providing the required `IoLoc` implementations on `usize`, we can
leverage the generic accessors and reduce the number of unsafe blocks in
the module.
This also allows us to directly call the generic `read/write/update`
methods with primitive types, so add examples illustrating this.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260314-register-v9-6-86805b2f7e9d@nvidia.com
[ Slightly improve wording in doc-comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
I/O accesses are defined by the following properties:
- An I/O location, which consists of a start address, a width, and a
type to interpret the read value as,
- A value, which is returned for reads or provided for writes.
Introduce the `IoLoc` trait, which allows implementing types to fully
specify an I/O location.
This allows I/O operations to be made generic through the new `read` and
`write` methods.
This design will allow us to factorize the I/O code working with
primitives, and to introduce ways to perform I/O with a higher degree of
control through register types.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260314-register-v9-5-86805b2f7e9d@nvidia.com
[ Fix incorrect reference to io_addr_assert() in try_update(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Relaxed I/O accessors for `Mmio` are currently implemented as an extra
set of methods that mirror the ones defined in `Io`, but with the
`_relaxed` suffix.
This makes these methods impossible to use with generic code, which is a
highly plausible proposition now that we have the `Io` trait.
Address this by adding a new `RelaxedMmio` wrapper type for `Mmio` that
provides its own `IoCapable` implementations relying on the relaxed C
accessors. This makes it possible to use relaxed operations on a `Mmio`
simply by wrapping it, and to use `RelaxedMmio` in code generic against
`Io`.
Acked-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260206-io-v2-3-71dea20a06e6@nvidia.com
[ Use kernel import style in examples. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
The `_relaxed` I/O variant methods are about to be replaced by a wrapper
type exposing this access pattern with the regular methods of the `Io`
trait. Thus replace the examples to use the regular I/O methods.
Since these are examples, we want them to use the most standard ops
anyway, and the relaxed variants were but an addition that was
MMIO-specific.
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Acked-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260206-io-v2-2-71dea20a06e6@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
`IoCapable<T>` is currently used as a marker trait to signal that the
methods of the `Io` trait corresponding to `T` have been overridden by
the implementor (the default implementations triggering a build-time
error).
This goes against the DRY principle and separates the signaling of the
capability from its implementation, making it possible to forget a step
while implementing a new `Io`.
Another undesirable side-effect is that it makes the implementation of
I/O backends boilerplate-y and convoluted: currently this is done using
two levels of imbricated macros that generate unsafe code.
Fix these issues by turning `IoCapable` into a functional trait that
includes the raw implementation of the I/O access for `T` using
unsafe methods that work with an arbitrary address.
This allows us to turn the default methods of `Io` into regular methods
that check the passed offset, turn it into an address, and call into the
corresponding `IoCapable` functions, removing the need to overload them
at all.
`IoCapable` must still be implemented for all supported primitive types,
which is still done more concisely using a macro, but this macro becomes
much simpler and does not require calling into another one.
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Acked-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260206-io-v2-1-71dea20a06e6@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Pull Rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Remap paths to avoid absolute ones starting with the upcoming Rust
1.95.0 release. This improves build reproducibility, avoids leaking
the exact path and avoids having the same path appear in two forms
The approach here avoids remapping debug information as well, in
order to avoid breaking tools that used the paths to access source
files, which was the previous attempt that needed to be reverted
- Allow 'unused_features' lint for the upcoming Rust 1.96.0 release.
While well-intentioned, we do not benefit much from the new lint
- Emit dependency information into '$(depfile)' directly to avoid a
temporary '.d' file (it was an old approach)
'kernel' crate:
- 'str' module: fix warning under '!CONFIG_BLOCK' by making
'NullTerminatedFormatter' public
- 'cpufreq' module: suppress false positive Clippy warning
'pin-init' crate:
- Remove '#[disable_initialized_field_access]' attribute which was
unsound. This means removing the support for structs with unaligned
fields (through the 'repr(packed)' attribute), for now
And document the load-bearing fact of field accessors (i.e. that
they are required for soundness)
- Replace shadowed return token by 'unsafe'-to-create token in order
to remain sound in the face of the likely upcoming Type Alias Impl
Trait (TAIT) and the next trait solver in upstream Rust"
* tag 'rust-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: kbuild: allow `unused_features`
rust: cpufreq: suppress clippy::double_parens in Policy doctest
rust: pin-init: replace shadowed return token by `unsafe`-to-create token
rust: pin-init: internal: init: document load-bearing fact of field accessors
rust: pin-init: internal: init: remove `#[disable_initialized_field_access]`
rust: build: remap path to avoid absolute path
rust: kbuild: emit dep-info into $(depfile) directly
rust: str: make NullTerminatedFormatter public
We use a unit struct `__InitOk` in the closure generated by the
initializer macros as the return value. We shadow it by creating a
struct with the same name again inside of the closure, preventing early
returns of `Ok` in the initializer (before all fields have been
initialized).
In the face of Type Alias Impl Trait (TAIT) and the next trait solver,
this solution no longer works [1]. The shadowed struct can be named
through type inference. In addition, there is an RFC proposing to add
the feature of path inference to Rust, which would similarly allow [2].
Thus remove the shadowed token and replace it with an `unsafe` to create
token.
The reason we initially used the shadowing solution was because an
alternative solution used a builder pattern. Gary writes [3]:
In the early builder-pattern based InitOk, having a single InitOk
type for token is unsound because one can launder an InitOk token
used for one place to another initializer. I used a branded lifetime
solution, and then you figured out that using a shadowed type would
work better because nobody could construct it at all.
The laundering issue does not apply to the approach we ended up with
today.
With this change, the example by Tim Chirananthavat in [1] no longer
compiles and results in this error:
error: cannot construct `pin_init::__internal::InitOk` with struct literal syntax due to private fields
--> src/main.rs:26:17
|
26 | InferredType {}
| ^^^^^^^^^^^^
|
= note: private field `0` that was not provided
help: you might have meant to use the `new` associated function
|
26 - InferredType {}
26 + InferredType::new()
|
Applying the suggestion of using the `::new()` function, results in
another expected error:
error[E0133]: call to unsafe function `pin_init::__internal::InitOk::new` is unsafe and requires unsafe block
--> src/main.rs:26:17
|
26 | InferredType::new()
| ^^^^^^^^^^^^^^^^^^^ call to unsafe function
|
= note: consult the function's documentation for information on how to avoid undefined behavior
Reported-by: Tim Chirananthavat <theemathas@gmail.com>
Link: https://github.com/rust-lang/rust/issues/153535 [1]
Link: https://github.com/rust-lang/rfcs/pull/3444#issuecomment-4016145373 [2]
Link: https://github.com/rust-lang/rust/issues/153535#issuecomment-4017620804 [3]
Fixes: fc6c6baa1f ("rust: init: add initialization macros")
Cc: stable@vger.kernel.org
Signed-off-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260311105056.1425041-1-lossin@kernel.org
[ Added period as mentioned. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Current `dma_read!`, `dma_write!` macros also use a custom
`addr_of!()`-based implementation for projecting pointers, which has
soundness issue as it relies on absence of `Deref` implementation on types.
It also has a soundness issue where it does not protect against unaligned
fields (when `#[repr(packed)]` is used) so it can generate misaligned
accesses.
This commit migrates them to use the general pointer projection
infrastructure, which handles these cases correctly.
As part of migration, the macro is updated to have an improved surface
syntax. The current macro have
dma_read!(a.b.c[d].e.f)
to mean `a.b.c` is a DMA coherent allocation and it should project into it
with `[d].e.f` and do a read, which is confusing as it makes the indexing
operator integral to the macro (so it will break if you have an array of
`CoherentAllocation`, for example).
This also is problematic as we would like to generalize
`CoherentAllocation` from just slices to arbitrary types.
Make the macro expects `dma_read!(path.to.dma, .path.inside.dma)` as the
canonical syntax. The index operator is no longer special and is just one
type of projection (in additional to field projection). Similarly, make
`dma_write!(path.to.dma, .path.inside.dma, value)` become the canonical
syntax for writing.
Another issue of the current macro is that it is always fallible. This
makes sense with existing design of `CoherentAllocation`, but once we
support fixed size arrays with `CoherentAllocation`, it is desirable to
have the ability to perform infallible indexing as well, e.g. doing a `[0]`
index of `[Foo; 2]` is okay and can be checked at build-time, so forcing
falliblity is non-ideal. To capture this, the macro is changed to use
`[idx]` as infallible projection and `[idx]?` as fallible index projection
(those syntax are part of the general projection infra). A benefit of this
is that while individual indexing operation may fail, the overall
read/write operation is not fallible.
Fixes: ad2907b4e3 ("rust: add dma coherent allocator abstraction")
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260302164239.284084-4-gary@kernel.org
[ Capitalize safety comments; slightly improve wording in doc-comments.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a generic infrastructure for performing field and index projections on
raw pointers. This will form the basis of performing I/O projections.
Pointers manipulations are intentionally using the safe wrapping variants
instead of the unsafe variants, as the latter requires pointers to be
inside an allocation which is not necessarily true for I/O pointers.
This projection macro protects against rogue `Deref` implementation, which
can causes the projected pointer to be outside the bounds of starting
pointer. This is extremely unlikely and Rust has a lint to catch this, but
is unsoundness regardless. The protection works by inducing type inference
ambiguity when `Deref` is implemented.
This projection macro also stops projecting into unaligned fields (i.e.
fields of `#[repr(packed)]` structs), as misaligned pointers require
special handling. This is implemented by attempting to create reference to
projected field inside a `if false` block. Despite being unreachable, Rust
still checks that they're not unaligned fields.
The projection macro supports both fallible and infallible index
projections. These are described in detail inside the documentation.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20260302164239.284084-3-gary@kernel.org
[ * Add intro-doc links where possible,
* Fix typos and slightly improve wording, e.g. "as documentation
describes" -> "as the documentation of [`Self::proj`] describes",
* Add an empty line between regular and safety comments, before
examples, and between logically independent comments,
* Capitalize various safety comments.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add a `KnownSize` trait which is used obtain a size from a raw pointer's
metadata. This makes it possible to obtain size information on a raw slice
pointer. This is similar to Rust `core::mem::size_of_val_raw` which is not
yet stable.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20260302164239.284084-2-gary@kernel.org
[ Fix wording in doc-comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Pull kunit fixes from Shuah Khan:
- Fix rust warnings when CONFIG_PRINTK is disabled
- Reduce stack usage in kunit_run_tests() to fix warnings when
CONFIG_FRAME_WARN is set to a relatively low value
- Update email address for David Gow
- Copy caller args in kunit tool in run_kernel to prevent mutation
* tag 'linux_kselftest-kunit-fixes-7.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
kunit: reduce stack usage in kunit_run_tests()
kunit: tool: copy caller args in run_kernel to prevent mutation
rust: kunit: fix warning when !CONFIG_PRINTK
MAINTAINERS: Update email address for David Gow
Gary noticed [1] that the initializer macros as well as the `[Pin]Init`
traits cannot support unaligned fields, since they use operations that
require aligned pointers. This means that any code using structs with
unaligned fields in pin-init is unsound.
By default, the `init!` macro generates references to initialized fields,
which makes the compiler check that those fields are aligned. However,
we added the `#[disable_initialized_field_access]` attribute to avoid
this behavior in commit ceca298c53 ("rust: pin-init: internal: init:
add escape hatch for referencing initialized fields"). Thus remove the
`#[disable_initialized_field_access]` attribute from `init!`, which is
the only safe way to create an initializer handling unaligned fields.
If support for in-place initializing structs with unaligned fields is
required in the future, we could figure out a solution. This is tracked
in [2].
Reported-by: Gary Guo <gary@garyguo.net>
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/561532-pin-init/topic/initialized.20field.20accessor.20detection/with/576210658 [1]
Link: https://github.com/Rust-for-Linux/pin-init/issues/112 [2]
Fixes: ceca298c53 ("rust: pin-init: internal: init: add escape hatch for referencing initialized fields")
Signed-off-by: Benno Lossin <lossin@kernel.org>
Acked-by: Janne Grunau <j@jannau.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260302140424.4097655-1-lossin@kernel.org
[ Adjusted tags and reworded as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When building with an out directory (O=), absolute paths can end up in the
file name in `#[track_caller]` or the panic message. This is not desirable
as this leaks the exact path being used to build the kernel and means that
the same location can appear in two forms (relative or absolute).
This is reported by Asahi [1] and is being workaround in [2] previously to
force everything to be absolute path. Using absolute path for everything
solves the inconsistency, however it does not address the reproducibility
issue. So, fix this by remap all absolute paths to srctree to relative path
instead.
This is previously attempted in commit dbdffaf50f ("kbuild, rust: use
-fremap-path-prefix to make paths relative") but that was reverted as
remapping debug info causes some tool (e.g. objdump) to be unable to find
sources. Therefore, use `--remap-path-scope` to only remap macros but leave
debuginfo untouched. `--remap-path-scope` is only stable in Rust 1.95, so
use `rustc-option` to detect its presence. This feature has been available
as `-Zremap-path-scope` for all versions that we support; however due to
bugs in the Rust compiler, it does not work reliably until 1.94. I opted to
not enable it for 1.94 as it's just a single version that we missed.
This change can be validated by building a kernel with O=, strip debug info
on vmlinux, and then check if the absolute path exists in `strings
vmlinux`, e.g. `strings vmlinux |grep \/home`.
Reported-by: Janne Grunau <j@jannau.net>
Reported-by: Asahi Lina <lina+kernel@asahilina.net>
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Per-call-site.20data.20and.20lock.20class.20keys/near/572466559 [1]
Link: 54ab888788 [2]
Signed-off-by: Gary Guo <gary@garyguo.net>
Acked-by: Nicolas Schier <nsc@kernel.org> # kbuild
Link: https://patch.msgid.link/20260226152112.3222886-1-gary@kernel.org
[ Reworded for few typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
If `CONFIG_BLOCK` is disabled, the following warnings are displayed
during build:
warning: struct `NullTerminatedFormatter` is never constructed
--> ../rust/kernel/str.rs:667:19
|
667 | pub(crate) struct NullTerminatedFormatter<'a> {
| ^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
warning: associated function `new` is never used
--> ../rust/kernel/str.rs:673:19
|
671 | impl<'a> NullTerminatedFormatter<'a> {
| ------------------------------------ associated function in this implementation
672 | /// Create a new [`Self`] instance.
673 | pub(crate) fn new(buffer: &'a mut [u8]) -> Option<NullTerminatedFormatter<'a>> {
Fix them by making `NullTerminatedFormatter` public, as it could be
useful for drivers anyway.
Fixes: cdde7a1951 ("rust: str: introduce `NullTerminatedFormatter`")
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260224-nullterminatedformatter-v1-1-5bef7b9b3d4c@nvidia.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
If `CONFIG_PRINTK` is not set, then the following warnings are issued
during build:
warning: unused variable: `args`
--> ../rust/kernel/kunit.rs:16:12
|
16 | pub fn err(args: fmt::Arguments<'_>) {
| ^^^^ help: if this is intentional, prefix it with an underscore: `_args`
|
= note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
warning: unused variable: `args`
--> ../rust/kernel/kunit.rs:32:13
|
32 | pub fn info(args: fmt::Arguments<'_>) {
| ^^^^ help: if this is intentional, prefix it with an underscore: `_args`
Fix this by adding a no-op assignment using `args` when `CONFIG_PRINTK`
is not set.
Fixes: a66d733da8 ("rust: support running Rust documentation tests as KUnit ones")
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: David Gow <david@davidgow.net>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Currently, the define_read!() and define_write!() I/O macros are crate
public. The only user outside of the I/O module is PCI (for the
configurations space I/O backend). Consequently, when CONFIG_PCI=n this
causes a compile time warning [1].
In order to fix this, rename the macros to io_define_read!() and
io_define_write!() and use #[macro_export] to export them.
This is better than making the crate public visibility conditional, as
eventually subsystems will have their own crate.
Also, I/O backends are valid to be implemented by drivers as well. For
instance, there are devices (such as GPUs) that run firmware which
allows to program other devices only accessible through the primary
device through indirect I/O.
Since the macros are now public, also add the corresponding
documentation.
Fixes: 121d87b28e ("rust: io: separate generic I/O helpers from MMIO implementation")
Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Closes: https://lore.kernel.org/driver-core/CANiq72khOYkt6t5zwMvSiyZvWWHMZuNCMERXu=7K=_5tT-8Pgg@mail.gmail.com/ [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20260216131534.65008-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Pull rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Pass '-Zunstable-options' flag required by the future Rust 1.95.0
- Fix 'objtool' warning for Rust 1.84.0
'kernel' crate:
- 'irq' module: add missing bound detected by the future Rust 1.95.0
- 'list' module: add missing 'unsafe' blocks and placeholder safety
comments to macros (an issue for future callers within the crate)
'pin-init' crate:
- Clean Clippy warning that changed behavior in the future Rust
1.95.0"
* tag 'rust-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: list: Add unsafe blocks for container_of and safety comments
rust: pin-init: replace clippy `expect` with `allow`
rust: irq: add `'static` bounds to irq callbacks
objtool/rust: add one more `noreturn` Rust function
rust: kbuild: pass `-Zunstable-options` for Rust 1.95.0
impl_list_item_mod.rs calls container_of! without unsafe blocks at a
couple of places. Since container_of! is unsafe, the blocks are strictly
necessary.
The problem was so far not visible because the "unsafe-op-in-unsafe-fn"
check is a lint rather than a hard compiler error, and Rust suppresses
lints triggered inside of a macro from another crate.
Thus, the error becomes only visible once someone from within the kernel
crate tries to use linked lists:
error[E0133]: call to unsafe function `core::ptr::mut_ptr::<impl *mut T>::byte_sub`
is unsafe and requires unsafe block
--> rust/kernel/lib.rs:252:29
|
252 | let container_ptr = field_ptr.byte_sub(offset).cast::<$Container>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ call to unsafe function
|
::: rust/kernel/drm/jq.rs:98:1
|
98 | / impl_list_item! {
99 | | impl ListItem<0> for BasicItem { using ListLinks { self.links }; }
100 | | }
| |_- in this macro invocation
|
note: an unsafe function restricts its caller, but its body is safe by default
--> rust/kernel/list/impl_list_item_mod.rs:216:13
|
216 | unsafe fn view_value(me: *mut $crate::list::ListLinks<$num>) -> *const Self {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
::: rust/kernel/drm/jq.rs:98:1
|
98 | / impl_list_item! {
99 | | impl ListItem<0> for BasicItem { using ListLinks { self.links }; }
100 | | }
| |_- in this macro invocation
= note: requested on the command line with `-D unsafe-op-in-unsafe-fn`
= note: this error originates in the macro `$crate::container_of` which comes
from the expansion of the macro `impl_list_item`
Therefore, add unsafe blocks to container_of! calls to fix the issue.
[ As discussed, let's fix the build for those that want to use the
macro within the `kernel` crate now and we can discuss the proper
safety comments afterwards. Thus I removed the ones from the patch.
However, we cannot just avoid the comments with `CLIPPY=1`, so I
provided placeholders for now, like we did in the past. They were
also needed for an `unsafe impl`.
While I am not happy about it, it isn't worse than the current
status (the comments were meant to be there), and at least this
shows what is missing -- our pre-existing "good first issue" [1]
may motivate new contributors to complete them properly.
Finally, I moved one of the existing safety comments one line down
so that Clippy could locate it.
Link: https://github.com/Rust-for-Linux/linux/issues/351 [1]
- Miguel ]
Cc: stable@vger.kernel.org
Fixes: c77f85b347 ("rust: list: remove OFFSET constants")
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260216131613.45344-3-phasta@kernel.org
[ Fixed formatting. Reworded to fix the lint suppression
explanation. Indent build error. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`clippy` has changed behavior in [1] (Rust 1.95) where it no longer
warns about the `let_and_return` lint when a comment is placed between
the let binding and the return expression. Nightly thus fails to build,
because the expectation is no longer fulfilled.
Thus replace the expectation with an `allow`.
[ The errors were:
error: this lint expectation is unfulfilled
--> rust/pin-init/src/lib.rs:1279:10
|
1279 | #[expect(clippy::let_and_return)]
| ^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D unfulfilled-lint-expectations` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(unfulfilled_lint_expectations)]`
error: this lint expectation is unfulfilled
--> rust/pin-init/src/lib.rs:1295:10
|
1295 | #[expect(clippy::let_and_return)]
| ^^^^^^^^^^^^^^^^^^^^^^
- Miguel ]
Link: https://github.com/rust-lang/rust-clippy/pull/16461 [1]
Signed-off-by: Benno Lossin <lossin@kernel.org>
Cc: stable@vger.kernel.org # Needed in 6.18.y and later.
Link: https://patch.msgid.link/20260215132232.1549861-1-lossin@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
These callback functions take a generic `T` that is used in the body as
the generic argument in `Registration` and `ThreadedRegistration`. Those
types require `T: 'static`, but due to a compiler bug this requirement
isn't propagated to the function. Thus add the bound. This was caught in
the upstream Rust CI [1].
[ The three errors looked similar and will start appearing with Rust
1.95.0 (expected 2026-04-16). The first one was:
error[E0310]: the parameter type `T` may not live long enough
Error: --> rust/kernel/irq/request.rs:266:43
|
266 | let registration = unsafe { &*(ptr as *const Registration<T>) };
| ^^^^^^^^^^^^^^^^^^^^^^
| |
| the parameter type `T` must be valid for the static lifetime...
| ...so that the type `T` will meet its required lifetime bounds
|
help: consider adding an explicit lifetime bound
|
264 | unsafe extern "C" fn handle_irq_callback<T: Handler + 'static>(_irq: i32, ptr: *mut c_void) -> c_uint {
| +++++++++
- Miguel ]
Link: https://github.com/rust-lang/rust/pull/149389 [1]
Signed-off-by: Benno Lossin <lossin@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 29e16fcd67 ("rust: irq: add &Device<Bound> argument to irq callbacks")
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/rust-for-linux/20260217222425.8755-1-cole@unwrap.rs/
Link: https://patch.msgid.link/20260214092740.3201946-1-lossin@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull USB / Thunderbolt updates from Greg KH:
"Here is the "big" set of USB and Thunderbolt driver updates for
7.0-rc1. Overall more lines were removed than added, thanks to
dropping the obsolete isp1362 USB host controller driver, always a
nice change.
Other than that, nothing major happening here, highlights are:
- lots of dwc3 driver updates and new hardware support added
- usb gadget function driver updates
- usb phy driver updates
- typec driver updates and additions
- USB rust binding updates for syntax and formatting changes
- more usb serial device ids added
- other smaller USB core and driver updates and additions
All of these have been in linux-next for a long time, with no reported
problems"
* tag 'usb-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (77 commits)
usb: typec: ucsi: Add Thunderbolt alternate mode support
usb: typec: hd3ss3220: Check if regulator needs to be switched
usb: phy: tegra: parametrize PORTSC1 register offset
usb: phy: tegra: parametrize HSIC PTS value
usb: phy: tegra: return error value from utmi_wait_register
usb: phy: tegra: cosmetic fixes
dt-bindings: usb: renesas,usbhs: Add RZ/G3E SoC support
usb: dwc2: fix resume failure if dr_mode is host
usb: cdns3: fix role switching during resume
usb: dwc3: gadget: Move vbus draw to workqueue context
USB: serial: option: add Telit FN920C04 RNDIS compositions
usb: dwc3: Log dwc3 address in traces
usb: gadget: tegra-xudc: Add handling for BLCG_COREPLL_PWRDN
usb: phy: tegra: add HSIC support
usb: phy: tegra: use phy type directly
usb: typec: ucsi: Enforce mode selection for cros_ec_ucsi
usb: typec: ucsi: Support mode selection to activate altmodes
usb: typec: Introduce mode_selection bit
usb: typec: Implement mode selection
usb: typec: Expose alternate mode priority via sysfs
...
