linux.git/samples/rust/rust_driver_auxiliary.rs, branch v7.2-rc2 Linux kernel source tree samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data 2026-05-27T14:29:34+00:00 Danilo Krummrich dakr@kernel.org 2026-05-25T20:21:11+00:00 d18f3646184fc805d213fc049fc3b5d9fb9a6a27 Make the Data struct lifetime-parameterized, storing a reference to the parent pci::Device<Bound>. This demonstrates that registration data can hold device resources tied to the parent driver's lifetime. In connect(), retrieve the parent PCI device from the registration data rather than casting through adev.parent(). Reviewed-by: Eliot Courtney <ecourtney@nvidia.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Link: https://patch.msgid.link/20260525202921.124698-25-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Make the Data struct lifetime-parameterized, storing a reference to the
parent pci::Device<Bound>. This demonstrates that registration data can
hold device resources tied to the parent driver's lifetime.

In connect(), retrieve the parent PCI device from the registration data
rather than casting through adev.parent().

Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260525202921.124698-25-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: auxiliary: generalize Registration over ForLt 2026-05-27T14:27:28+00:00 Danilo Krummrich dakr@kernel.org 2026-05-25T20:21:10+00:00 4555291ddae9abe2c40a7eae192b1976b07a1fad Generalize Registration<T> to Registration<F: ForLt> and Device::registration_data<F: ForLt>() to return Pin<&F::Of<'_>>. The stored 'static lifetime is shortened to the borrow lifetime of &self via ForLt::cast_ref; ForLt's covariance guarantee makes this sound. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Eliot Courtney <ecourtney@nvidia.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260525202921.124698-24-dakr@kernel.org [ Use PhantomData<F::Of<'a>> instead of PhantomData<(fn(&'a ()) -> &'a (), F)>], which also gets us rid of #[allow(clippy::type_complexity)]. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Generalize Registration<T> to Registration<F: ForLt> and
Device::registration_data<F: ForLt>() to return Pin<&F::Of<'_>>.

The stored 'static lifetime is shortened to the borrow lifetime of &self
via ForLt::cast_ref; ForLt's covariance guarantee makes this sound.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-24-dakr@kernel.org
[ Use PhantomData<F::Of<'a>> instead of
  PhantomData<(fn(&'a ()) -> &'a (), F)>], which also gets us rid of
  #[allow(clippy::type_complexity)]. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: auxiliary: make Driver trait lifetime-parameterized 2026-05-27T14:23:47+00:00 Danilo Krummrich dakr@kernel.org 2026-05-25T20:21:01+00:00 46f651d88662ef931555cd135f09382af206295a Add a 'bound lifetime to the associated Data, changing type Data to type Data<'bound>. This allows the driver's bus device private data to capture the device / driver bound lifetime; device resources can be stored directly by reference rather than requiring Devres. The probe() and unbind() callbacks thus gain a 'bound lifetime parameter on the methods themselves; avoiding a global lifetime on the trait impl. Existing drivers set type Data<'bound> = Self, preserving the current behavior. Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260525202921.124698-15-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Add a 'bound lifetime to the associated Data, changing type Data to type
Data<'bound>.

This allows the driver's bus device private data to capture the device /
driver bound lifetime; device resources can be stored directly by
reference rather than requiring Devres.

The probe() and unbind() callbacks thus gain a 'bound lifetime parameter
on the methods themselves; avoiding a global lifetime on the trait impl.

Existing drivers set type Data<'bound> = Self, preserving the current
behavior.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-15-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: pci: make Driver trait lifetime-parameterized 2026-05-27T14:23:10+00:00 Danilo Krummrich dakr@kernel.org 2026-05-25T20:20:59+00:00 16c2b8fdab7c0808ff36430b2f49569029a8f484 Add a 'bound lifetime to the associated Data, changing type Data to type Data<'bound>. This allows the driver's bus device private data to capture the device / driver bound lifetime; device resources can be stored directly by reference rather than requiring Devres. The probe() and unbind() callbacks thus gain a 'bound lifetime parameter on the methods themselves; avoiding a global lifetime on the trait impl. Existing drivers set type Data<'bound> = Self, preserving the current behavior. Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260525202921.124698-13-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Add a 'bound lifetime to the associated Data, changing type Data to type
Data<'bound>.

This allows the driver's bus device private data to capture the device /
driver bound lifetime; device resources can be stored directly by
reference rather than requiring Devres.

The probe() and unbind() callbacks thus gain a 'bound lifetime parameter
on the methods themselves; avoiding a global lifetime on the trait impl.

Existing drivers set type Data<'bound> = Self, preserving the current
behavior.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-13-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: device: make Core and CoreInternal lifetime-parameterized 2026-05-27T14:22:42+00:00 Danilo Krummrich dakr@kernel.org 2026-05-25T20:20:58+00:00 24799831d631239ff21ea1bf7feee832df48b81f Device<Core> references in probe callbacks are scoped to the callback, not the full binding duration. Add a lifetime parameter to Core and CoreInternal to accurately represent this in the type system. Suggested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Eliot Courtney <ecourtney@nvidia.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260525202921.124698-12-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Device<Core> references in probe callbacks are scoped to the callback,
not the full binding duration. Add a lifetime parameter to Core and
CoreInternal to accurately represent this in the type system.

Suggested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-12-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: driver: decouple driver private data from driver type 2026-05-27T14:22:41+00:00 Danilo Krummrich dakr@kernel.org 2026-05-25T20:20:51+00:00 7fdffdda630ee61ae0e09ef8f1ace52bbf70e2b0 Add a type Data<'bound> associated type to all bus driver traits, decoupling the driver's bus device private data type from the driver struct itself. In the context of adding a 'bound lifetime, making this an associated type has the advantage that it allows us to avoid a driver trait global lifetime and it avoids the need for ForLt for bus device private data; both of which make the subsequent implementation by buses much simpler. All existing drivers and doc examples set type Data = Self to preserve the current behavior. Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260525202921.124698-5-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Add a type Data<'bound> associated type to all bus driver traits,
decoupling the driver's bus device private data type from the driver
struct itself.

In the context of adding a 'bound lifetime, making this an associated
type has the advantage that it allows us to avoid a driver trait global
lifetime and it avoids the need for ForLt for bus device private data;
both of which make the subsequent implementation by buses much simpler.

All existing drivers and doc examples set type Data = Self to preserve
the current behavior.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260525202921.124698-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
rust: auxiliary: add registration data to auxiliary devices 2026-05-11T13:26:12+00:00 Danilo Krummrich dakr@kernel.org 2026-05-05T15:23:08+00:00 fd3b87ff0232f46e1ad53a48609a3853c8757c6c Add a registration_data pointer to struct auxiliary_device, allowing the registering (parent) driver to attach private data to the device at registration time and retrieve it later when called back by the auxiliary (child) driver. By tying the data to the device's registration, Rust drivers can bind the lifetime of device resources to it, since the auxiliary bus guarantees that the parent driver remains bound while the auxiliary device is bound. On the Rust side, Registration<T> takes ownership of the data via ForeignOwnable. A TypeId is stored alongside the data for runtime type checking, making Device::registration_data<T>() a safe method. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260505152400.3905096-3-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
Add a registration_data pointer to struct auxiliary_device, allowing the
registering (parent) driver to attach private data to the device at
registration time and retrieve it later when called back by the
auxiliary (child) driver.

By tying the data to the device's registration, Rust drivers can bind
the lifetime of device resources to it, since the auxiliary bus
guarantees that the parent driver remains bound while the auxiliary
device is bound.

On the Rust side, Registration<T> takes ownership of the data via
ForeignOwnable. A TypeId is stored alongside the data for runtime type
checking, making Device::registration_data<T>() a safe method.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260505152400.3905096-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Merge tag 'driver-core-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core 2026-02-12T01:43:59+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-02-12T01:43:59+00:00 c6e62d002b7f0613f02d8707c80f2a7bd66808a0 Pull driver core updates from Danilo Krummrich: "Bus: - Ensure bus->match() is consistently called with the device lock held - Improve type safety of bus_find_device_by_acpi_dev() Devtmpfs: - Parse 'devtmpfs.mount=' boot parameter with kstrtoint() instead of simple_strtoul() - Avoid sparse warning by making devtmpfs_context_ops static IOMMU: - Do not register the qcom_smmu_tbu_driver in arm_smmu_device_probe() MAINTAINERS: - Add the new driver-core mailing list (driver-core@lists.linux.dev) to all relevant entries - Add missing tree location for "FIRMWARE LOADER (request_firmware)" - Add driver-model documentation to the "DRIVER CORE" entry - Add missing driver-core maintainers to the "AUXILIARY BUS" entry Misc: - Change return type of attribute_container_register() to void; it has always been infallible - Do not export sysfs_change_owner(), sysfs_file_change_owner() and device_change_owner() - Move devres_for_each_res() from the public devres header to drivers/base/base.h - Do not use a static struct device for the faux bus; allocate it dynamically Revocable: - Patches for the revocable synchronization primitive have been scheduled for v7.0-rc1, but have been reverted as they need some more refinement Rust: - Device: - Support dev_printk on all device types, not just the core Device struct; remove now-redundant .as_ref() calls in dev_* print calls - Devres: - Introduce an internal reference count in Devres<T> to avoid a deadlock condition in case of (indirect) nesting - DMA: - Allow drivers to tune the maximum DMA segment size via dma_set_max_seg_size() - I/O: - Introduce the concept of generic I/O backends to handle different kinds of device shared memory through a common interface. This enables higher-level concepts such as register abstractions, I/O slices, and field projections to be built generically on top. In a first step, introduce the Io, IoCapable<T>, and IoKnownSize trait hierarchy for sharing a common interface supporting offset validation and bound-checking logic between I/O backends. - Refactor MMIO to use the common I/O backend infrastructure - Misc: - Add __rust_helper annotations to C helpers for inlining into Rust code - Use "kernel vertical" style for imports - Replace kernel::c_str! with C string literals - Update ARef imports to use sync::aref - Use pin_init::zeroed() for struct auxiliary_device_id and debugfs file_operations initialization - Use LKMM atomic types in debugfs doc-tests - Various minor comment and documentation fixes - PCI: - Implement PCI configuration space accessors using the common I/O backend infrastructure - Document pci::Bar device endianness assumptions - SoC: - Abstractions for struct soc_device and struct soc_device_attribute - Sample driver for soc::Device" * tag 'driver-core-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (79 commits) rust: devres: fix race condition due to nesting rust: dma: add missing __rust_helper annotations samples: rust: pci: Remove some additional `.as_ref()` for `dev_*` print Revert "revocable: Revocable resource management" Revert "revocable: Add Kunit test cases" Revert "selftests: revocable: Add kselftest cases" driver core: remove device_change_owner() export sysfs: remove exports of sysfs_*change_owner() driver core: disable revocable code from build revocable: Add KUnit test for concurrent access revocable: fix SRCU index corruption by requiring caller-provided storage revocable: Add KUnit test for provider lifetime races revocable: Fix races in revocable_alloc() using RCU driver core: fix inverted "locked" suffix of driver_match_device() rust: io: move MIN_SIZE and io_addr_assert to IoKnownSize rust: pci: re-export ConfigSpace rust: dma: allow drivers to tune max segment size gpu: tyr: remove redundant `.as_ref()` for `dev_*` print rust: auxiliary: use `pin_init::zeroed()` for device ID rust: debugfs: use pin_init::zeroed() for file_operations ... 
Pull driver core updates from Danilo Krummrich:
 "Bus:

   - Ensure bus->match() is consistently called with the device lock
     held

   - Improve type safety of bus_find_device_by_acpi_dev()

  Devtmpfs:

   - Parse 'devtmpfs.mount=' boot parameter with kstrtoint() instead of
     simple_strtoul()

   - Avoid sparse warning by making devtmpfs_context_ops static

  IOMMU:

   - Do not register the qcom_smmu_tbu_driver in arm_smmu_device_probe()

  MAINTAINERS:

   - Add the new driver-core mailing list (driver-core@lists.linux.dev)
     to all relevant entries

   - Add missing tree location for "FIRMWARE LOADER (request_firmware)"

   - Add driver-model documentation to the "DRIVER CORE" entry

   - Add missing driver-core maintainers to the "AUXILIARY BUS" entry

  Misc:

   - Change return type of attribute_container_register() to void; it
     has always been infallible

   - Do not export sysfs_change_owner(), sysfs_file_change_owner() and
     device_change_owner()

   - Move devres_for_each_res() from the public devres header to
     drivers/base/base.h

   - Do not use a static struct device for the faux bus; allocate it
     dynamically

  Revocable:

   - Patches for the revocable synchronization primitive have been
     scheduled for v7.0-rc1, but have been reverted as they need some
     more refinement

  Rust:

   - Device:
      - Support dev_printk on all device types, not just the core Device
        struct; remove now-redundant .as_ref() calls in dev_* print
        calls

   - Devres:
      - Introduce an internal reference count in Devres<T> to avoid a
        deadlock condition in case of (indirect) nesting

   - DMA:
      - Allow drivers to tune the maximum DMA segment size via
        dma_set_max_seg_size()

   - I/O:
      - Introduce the concept of generic I/O backends to handle
        different kinds of device shared memory through a common
        interface.

        This enables higher-level concepts such as register
        abstractions, I/O slices, and field projections to be built
        generically on top.

        In a first step, introduce the Io, IoCapable<T>, and IoKnownSize
        trait hierarchy for sharing a common interface supporting offset
        validation and bound-checking logic between I/O backends.

      - Refactor MMIO to use the common I/O backend infrastructure

   - Misc:
      - Add __rust_helper annotations to C helpers for inlining into
        Rust code

      - Use "kernel vertical" style for imports

      - Replace kernel::c_str! with C string literals

      - Update ARef imports to use sync::aref

      - Use pin_init::zeroed() for struct auxiliary_device_id and
        debugfs file_operations initialization

      - Use LKMM atomic types in debugfs doc-tests

      - Various minor comment and documentation fixes

   - PCI:
      - Implement PCI configuration space accessors using the common I/O
        backend infrastructure

      - Document pci::Bar device endianness assumptions

   - SoC:
      - Abstractions for struct soc_device and struct soc_device_attribute

      - Sample driver for soc::Device"

* tag 'driver-core-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (79 commits)
  rust: devres: fix race condition due to nesting
  rust: dma: add missing __rust_helper annotations
  samples: rust: pci: Remove some additional `.as_ref()` for `dev_*` print
  Revert "revocable: Revocable resource management"
  Revert "revocable: Add Kunit test cases"
  Revert "selftests: revocable: Add kselftest cases"
  driver core: remove device_change_owner() export
  sysfs: remove exports of sysfs_*change_owner()
  driver core: disable revocable code from build
  revocable: Add KUnit test for concurrent access
  revocable: fix SRCU index corruption by requiring caller-provided storage
  revocable: Add KUnit test for provider lifetime races
  revocable: Fix races in revocable_alloc() using RCU
  driver core: fix inverted "locked" suffix of driver_match_device()
  rust: io: move MIN_SIZE and io_addr_assert to IoKnownSize
  rust: pci: re-export ConfigSpace
  rust: dma: allow drivers to tune max segment size
  gpu: tyr: remove redundant `.as_ref()` for `dev_*` print
  rust: auxiliary: use `pin_init::zeroed()` for device ID
  rust: debugfs: use pin_init::zeroed() for file_operations
  ...
samples: rust: remove imports available via prelude 2026-01-26T17:15:20+00:00 Gary Guo gary@garyguo.net 2026-01-23T17:19:42+00:00 fcbc35587778738145d4f18f95d44631a5c54845 These imports are already in scope by importing `kernel::prelude::*` and does not need to be imported separately. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260123172007.136873-4-gary@garyguo.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
These imports are already in scope by importing `kernel::prelude::*` and
does not need to be imported separately.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260123172007.136873-4-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: samples: driver-core: remove redundant `.as_ref()` for `dev_*` print 2026-01-24T00:12:49+00:00 Gary Guo gary@garyguo.net 2026-01-23T17:58:40+00:00 3be458a5a7ed57cb874474aee7929daed0d5d3aa This is now handled by the macro itself. Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260123175854.176735-3-gary@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> 
This is now handled by the macro itself.

Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260123175854.176735-3-gary@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>