linux.git/rust/kernel/device.rs, branch v7.1-rc2 Linux kernel source tree rust: device: add device name method 2026-03-24T22:51:23+00:00 Timur Tabi ttabi@nvidia.com 2026-03-19T21:26:53+00:00 d35ae50c5f48dfcd33cb24bf477ce912fa0af1f7 Add a name() method to the `Device` type, which returns a CStr that contains the device name. Signed-off-by: Timur Tabi <ttabi@nvidia.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: John Hubbard <jhubbard@nvidia.com> Tested-by: Eliot Courtney <ecourtney@nvidia.com> Link: https://patch.msgid.link/20260319212658.2541610-2-ttabi@nvidia.com Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Add a name() method to the `Device` type, which returns a CStr that
contains the device name.

Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Eliot Courtney <ecourtney@nvidia.com>
Link: https://patch.msgid.link/20260319212658.2541610-2-ttabi@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: dma: add generalized container for types other than slices 2026-03-23T21:15:03+00:00 Gary Guo gary@garyguo.net 2026-03-20T19:45:37+00:00 d9aee73c56ee971b08173071ad93fa5ebf00a32e 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> 
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>
Merge tag 'v6.19-rc7' into driver-core-next 2026-01-26T12:23:52+00:00 Danilo Krummrich dakr@kernel.org 2026-01-26T12:23:52+00:00 eb3dad518e4da48ab6c6df16aa8895b8b0bd6ecf We need the driver-core fixes in here as well to build on top of. Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
We need the driver-core fixes in here as well to build on top of.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: device: support `dev_printk` on all devices 2026-01-24T00:12:49+00:00 Gary Guo gary@garyguo.net 2026-01-23T17:58:38+00:00 a38cd1fea98990e20021823cea251e6cb088eeab Currently, `dev_*` only works on the core `Device`, but not on any other bus or class device objects. This causes a pattern of `dev_info!(pdev.as_ref())` which is not ideal. This adds support of using these devices directly with `dev_*` macros, by adding `AsRef` call inside the macro. To make sure we can still use just `kernel::device::Device`, as `AsRef` implementation is added for it; this is typical for types that is designed to use with `AsRef` anyway, for example, `str` implements `AsRef<str>` and `Path` implements `AsRef<Path>`. Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260123175854.176735-1-gary@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Currently, `dev_*` only works on the core `Device`, but not on any other
bus or class device objects. This causes a pattern of
`dev_info!(pdev.as_ref())` which is not ideal.

This adds support of using these devices directly with `dev_*` macros, by
adding `AsRef` call inside the macro. To make sure we can still use just
`kernel::device::Device`, as `AsRef` implementation is added for it; this
is typical for types that is designed to use with `AsRef` anyway, for
example, `str` implements `AsRef<str>` and `Path` implements `AsRef<Path>`.

Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260123175854.176735-1-gary@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: driver: drop device private data post unbind 2026-01-16T00:17:29+00:00 Danilo Krummrich dakr@kernel.org 2026-01-07T10:35:05+00:00 a995fe1a3aa78b7d06cc1cc7b6b8436c5e93b07f Currently, the driver's device private data is allocated and initialized from driver core code called from bus abstractions after the driver's probe() callback returned the corresponding initializer. Similarly, the driver's device private data is dropped within the remove() callback of bus abstractions after calling the remove() callback of the corresponding driver. However, commit 6f61a2637abe ("rust: device: introduce Device::drvdata()") introduced an accessor for the driver's device private data for a Device<Bound>, i.e. a device that is currently bound to a driver. Obviously, this is in conflict with dropping the driver's device private data in remove(), since a device can not be considered to be fully unbound after remove() has finished: We also have to consider registrations guarded by devres - such as IRQ or class device registrations - which are torn down after remove() in devres_release_all(). Thus, it can happen that, for instance, a class device or IRQ callback still calls Device::drvdata(), which then runs concurrently to remove() (which sets dev->driver_data to NULL and drops the driver's device private data), before devres_release_all() started to tear down the corresponding registration. This is because devres guarded registrations can, as expected, access the corresponding Device<Bound> that defines their scope. In C it simply is the driver's responsibility to ensure that its device private data is freed after e.g. an IRQ registration is unregistered. Typically, C drivers achieve this by allocating their device private data with e.g. devm_kzalloc() before doing anything else, i.e. before e.g. registering an IRQ with devm_request_threaded_irq(), relying on the reverse order cleanup of devres. Technically, we could do something similar in Rust. However, the resulting code would be pretty messy: In Rust we have to differentiate between allocated but uninitialized memory and initialized memory in the type system. Thus, we would need to somehow keep track of whether the driver's device private data object has been initialized (i.e. probe() was successful and returned a valid initializer for this memory) and conditionally call the destructor of the corresponding object when it is freed. This is because we'd need to allocate and register the memory of the driver's device private data *before* it is initialized by the initializer returned by the driver's probe() callback, because the driver could already register devres guarded registrations within probe() outside of the driver's device private data initializer. Luckily there is a much simpler solution: Instead of dropping the driver's device private data at the end of remove(), we just drop it after the device has been fully unbound, i.e. after all devres callbacks have been processed. For this, we introduce a new post_unbind() callback private to the driver-core, i.e. the callback is neither exposed to drivers, nor to bus abstractions. This way, the driver-core code can simply continue to conditionally allocate the memory for the driver's device private data when the driver's initializer is returned from probe() - no change needed - and drop it when the driver-core code receives the post_unbind() callback. Closes: https://lore.kernel.org/all/DEZMS6Y4A7XE.XE7EUBT5SJFJ@kernel.org/ Fixes: 6f61a2637abe ("rust: device: introduce Device::drvdata()") Acked-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20260107103511.570525-7-dakr@kernel.org [ Remove #ifdef CONFIG_RUST, rename post_unbind() to post_unbind_rust(). - Danilo] Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Currently, the driver's device private data is allocated and initialized
from driver core code called from bus abstractions after the driver's
probe() callback returned the corresponding initializer.

Similarly, the driver's device private data is dropped within the
remove() callback of bus abstractions after calling the remove()
callback of the corresponding driver.

However, commit 6f61a2637abe ("rust: device: introduce
Device::drvdata()") introduced an accessor for the driver's device
private data for a Device<Bound>, i.e. a device that is currently bound
to a driver.

Obviously, this is in conflict with dropping the driver's device private
data in remove(), since a device can not be considered to be fully
unbound after remove() has finished:

We also have to consider registrations guarded by devres - such as IRQ
or class device registrations - which are torn down after remove() in
devres_release_all().

Thus, it can happen that, for instance, a class device or IRQ callback
still calls Device::drvdata(), which then runs concurrently to remove()
(which sets dev->driver_data to NULL and drops the driver's device
private data), before devres_release_all() started to tear down the
corresponding registration. This is because devres guarded registrations
can, as expected, access the corresponding Device<Bound> that defines
their scope.

In C it simply is the driver's responsibility to ensure that its device
private data is freed after e.g. an IRQ registration is unregistered.

Typically, C drivers achieve this by allocating their device private data
with e.g. devm_kzalloc() before doing anything else, i.e. before e.g.
registering an IRQ with devm_request_threaded_irq(), relying on the
reverse order cleanup of devres.

Technically, we could do something similar in Rust. However, the
resulting code would be pretty messy:

In Rust we have to differentiate between allocated but uninitialized
memory and initialized memory in the type system. Thus, we would need to
somehow keep track of whether the driver's device private data object
has been initialized (i.e. probe() was successful and returned a valid
initializer for this memory) and conditionally call the destructor of
the corresponding object when it is freed.

This is because we'd need to allocate and register the memory of the
driver's device private data *before* it is initialized by the
initializer returned by the driver's probe() callback, because the
driver could already register devres guarded registrations within
probe() outside of the driver's device private data initializer.

Luckily there is a much simpler solution: Instead of dropping the
driver's device private data at the end of remove(), we just drop it
after the device has been fully unbound, i.e. after all devres callbacks
have been processed.

For this, we introduce a new post_unbind() callback private to the
driver-core, i.e. the callback is neither exposed to drivers, nor to bus
abstractions.

This way, the driver-core code can simply continue to conditionally
allocate the memory for the driver's device private data when the
driver's initializer is returned from probe() - no change needed - and
drop it when the driver-core code receives the post_unbind() callback.

Closes: https://lore.kernel.org/all/DEZMS6Y4A7XE.XE7EUBT5SJFJ@kernel.org/
Fixes: 6f61a2637abe ("rust: device: introduce Device::drvdata()")
Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-7-dakr@kernel.org
[ Remove #ifdef CONFIG_RUST, rename post_unbind() to post_unbind_rust().
 - Danilo]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Merge tag 'v6.19-rc5' into driver-core-next 2026-01-12T12:33:24+00:00 Danilo Krummrich dakr@kernel.org 2026-01-12T12:32:43+00:00 8f799b4e8cc0cf926019e40405dc3eab330ac643 We need the driver-core fixes in here as well to build on top of. Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
We need the driver-core fixes in here as well to build on top of.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: driver-core: use "kernel vertical" style for imports 2026-01-07T18:55:49+00:00 Danilo Krummrich dakr@kernel.org 2026-01-05T14:19:44+00:00 52563c665b0b0b39f319bee40ecc5e8f25b9050a Convert all imports to use "kernel vertical" style. With this, subsequent patches neither introduce unrelated changes nor leave an inconsistent import pattern. While at it, drop unnecessary imports covered by prelude::*. Link: https://docs.kernel.org/rust/coding-guidelines.html#imports Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260105142123.95030-3-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Convert all imports to use "kernel vertical" style.

With this, subsequent patches neither introduce unrelated changes nor
leave an inconsistent import pattern.

While at it, drop unnecessary imports covered by prelude::*.

Link: https://docs.kernel.org/rust/coding-guidelines.html#imports
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260105142123.95030-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: device: Remove explicit import of CStrExt 2026-01-06T20:18:31+00:00 FUJITA Tomonori fujita.tomonori@gmail.com 2026-01-06T00:03:20+00:00 8510ef5e3cfbd7d59a16845f85cd0194a8689761 Remove the explicit import of CStrExt. When CONFIG_PRINTK is disabled this import causes a build error: error: unused import: `crate::str::CStrExt` --> rust/kernel/device.rs:17:5 | 17 | use crate::str::CStrExt as _; | ^^^^^^^^^^^^^^^^^^^ | = note: `-D unused-imports` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(unused_imports)]` error: aborting due to 1 previous error CStrExt is covered by prelude::* so the explicit import is redundant. Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Fixes: 3b83f5d5e78a ("rust: replace `CStr` with `core::ffi::CStr`") Link: https://patch.msgid.link/20260106000320.2593800-1-fujita.tomonori@gmail.com Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Remove the explicit import of CStrExt. When CONFIG_PRINTK is disabled
this import causes a build error:

error: unused import: `crate::str::CStrExt`
  --> rust/kernel/device.rs:17:5
   |
17 | use crate::str::CStrExt as _;
   |     ^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D unused-imports` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(unused_imports)]`

error: aborting due to 1 previous error

CStrExt is covered by prelude::* so the explicit import is redundant.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Fixes: 3b83f5d5e78a ("rust: replace `CStr` with `core::ffi::CStr`")
Link: https://patch.msgid.link/20260106000320.2593800-1-fujita.tomonori@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: device: fix broken intra-doc links 2026-01-02T18:05:04+00:00 FUJITA Tomonori fujita.tomonori@gmail.com 2025-12-31T04:57:28+00:00 a9a42f0754b6c69525612d678b73da790e28b9fd The `pci` module is conditional on CONFIG_PCI. When it's disabled, the intra-doc link to `pci::Device` causes rustdoc warnings: warning: unresolved link to `kernel::pci::Device` --> rust/kernel/device.rs:163:22 | 163 | /// [`pci::Device`]: kernel::pci::Device | ^^^^^^^^^^^^^^^^^^^ no item named `pci` in module `kernel` | = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default Fix this by making the documentation conditional on CONFIG_PCI. Fixes: d6e26c1ae4a6 ("device: rust: expand documentation for Device") Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://patch.msgid.link/20251231045728.1912024-2-fujita.tomonori@gmail.com [ Keep the "such as" part indicating a list of examples; fix typos in commit message. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
The `pci` module is conditional on CONFIG_PCI. When it's disabled, the
intra-doc link to `pci::Device` causes rustdoc warnings:

warning: unresolved link to `kernel::pci::Device`
   --> rust/kernel/device.rs:163:22
    |
163 | /// [`pci::Device`]: kernel::pci::Device
    |                      ^^^^^^^^^^^^^^^^^^^ no item named `pci` in module `kernel`
    |
    = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default

Fix this by making the documentation conditional on CONFIG_PCI.

Fixes: d6e26c1ae4a6 ("device: rust: expand documentation for Device")
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://patch.msgid.link/20251231045728.1912024-2-fujita.tomonori@gmail.com
[ Keep the "such as" part indicating a list of examples; fix typos in
  commit message. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: device: replace `kernel::c_str!` with C-Strings 2025-12-22T16:30:24+00:00 Tamir Duberstein tamird@gmail.com 2025-12-22T12:35:28+00:00 f0c6ea853bd7f48aeec231e9378fc17cf36b9109 C-String literals were added in Rust 1.77. Replace instances of `kernel::c_str!` with C-String literals where possible. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://patch.msgid.link/20251222-cstr-driver-core-v1-2-1142a177d0fd@gmail.com Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
C-String literals were added in Rust 1.77. Replace instances of
`kernel::c_str!` with C-String literals where possible.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20251222-cstr-driver-core-v1-2-1142a177d0fd@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>