Commit Graph
25 Commits
Author SHA1 Message Date
Linus Torvalds 59e6295fac Merge tag 'driver-core-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
 "container_of:

   - Apply typeof_member(), remove the local __mptr variable to
     eliminate variable shadowing warnings on nested container_of()
     calls, and remove unnecessary parentheses

  core:

   - Add driver name to probe debug print for initcall_debug

   - Avoid repeatedly printing the same 'Fixed dependency cycle' log

   - Unwind device_add() on attribute creation failure in
     attribute_container_add_class_device()

   - Remove statistics group if encryption group creation fails in
     transport_add_class_device()

  debugfs:

   - Fix lockdown check for mmap_prepare()

   - Warn if file creation failed due to uninitialized debugfs

  device property:

   - Implement fw_devlink support for software nodes by adding
     software_node_add_links(), which creates fwnode links from
     DEV_PROP_REF properties to enable automatic probe ordering. Add
     kunit-managed fwnode helpers and test coverage

   - Fix infinite loop in fwnode_for_each_child_node() when the
     secondary fwnode has more than one child. Add test cases

   - Fix out-of-bounds access in software_node_get_reference_args() when
     called with index -1 (UINT_MAX)

   - Refactor to use RAII approach with __free()

   - Add Bartosz Golaszewski as software node reviewer

  firmware loader:

   - Fix race where a sysfs fallback request can complete before being
     queued as pending, leading to a use-after-free on the next fallback
     request

   - Reject 0-size built-in firmware and fail the build on empty
     firmware files in CONFIG_EXTRA_FIRMWARE

  kobject:

   - Provide __KOBJ_ATTR() and __KOBJ_ATTR_RO/WO() initialization macros
     and allow the constification of kobject attributes, enabling them
     to reside in read-only memory

  platform:

   - Provide platform_device_set_of_node(), platform_device_set_fwnode(),
     and platform_device_set_of_node_from_dev() helpers that encapsulate
     firmware node reference counting for dynamically allocated platform
     devices

     Convert all in-tree users that manually assigned dev.of_node or
     dev.fwnode, fixing a pre-existing refcount bug in powermac. Switch
     to counting references of all firmware node types, not only OF
     nodes

   - Unify the release path for dynamically allocated platform devices
     by removing platform_device_release_full(). Amend the fwnode setter
     API contract to warn if a primary software node is overwritten. Add
     KUnit tests for correct software node removal on device
     unregistration

  Rust:

   - Auxiliary:
       - Add registration_data_with() closure-based API for invariant
         ForLt types

   - Debugfs:
       - Migrate BinaryWriter and BinaryReaderMut trait requirements
         from kernel::transmute traits to zerocopy traits

   - Device:
       - Add BoundInternal device context and InternalBoundContext trait
         for bus abstractions that need internal access to a bound
         device.
       - Make the lifetime on Core and CoreInternal invariant to prevent
         coercion to shorter lifetimes

   - Devres:
       - Fix race between concurrent revokers where the losing revoker
         could return before the winning revoker finished dropping the
         inner data, causing use-after-free.
       - Ensure revocation is complete before the device finishes
         unbinding by making the synchronization bidirectional.
       - Add DevresLt<F: ForLt>, a wrapper around Devres that shortens
         'static back to the caller's borrow scope. Implement ForLt and
         CovariantForLt for Bar, IoMem, and ExclusiveIoMem

   - Driver:
       - Switch from index-based to pointer-based device ID info lookup,
         storing static references in driver_data. Centralize device ID
         handling in device_id.rs, removing the open-coded ACPI/OF
         matching logic and duplicate ID table from driver.rs

   - I/O:
       - Make I/O regions typed (with a dynamically-sized Region type
         for the existing untyped case), create view types representing
         subregions of a mapped I/O region, and add io_project!() for
         safely creating subviews.
       - Split Io into a base trait (IoBase) and an extension trait (Io)
         with a blanket implementation, preventing implementers from
         overriding provided methods that unsafe code relies on.
       - Add a SysMem backend for shared system memory with volatile
         access, and make Coherent implement Io via an I/O view type.
         Add IoSysMap as sum type of Mmio and SysMem. Add copying
         methods (memcpy_{from,to}io()) and read_val()/write_val() for
         typed access.
       - Replace dma_read!()/dma_write!() with io_read!()/io_write!()
         for primitives and copying methods for aggregates; drop the old
         macros. Convert nova-core to use I/O projection.
       - Fix internal shortcut rule dispatch in the register!() macro,
         remove unused rule arguments, and use path fragments for alias
         destinations

   - IRQ:
       - Make irq::Registration compatible with lifetime-bound drivers
         by removing the 'static bound on Handler/ThreadedHandler and
         replacing Devres<RegistrationInner> with direct
         request_irq()/free_irq() calls. Handlers can now directly own
         lifetime-bound device resources

   - PCI:
       - Convert IrqVectorRegistration to a lifetime-annotated owning
         type, giving drivers explicit control over the allocation
         lifetime. IrqVector embeds a resolved IrqRequest, making the
         conversion infallible. Remove the redundant
         request_irq()/request_threaded_irq() wrappers from pci::Device.
       - Add pci_irq_type() C helper and expose it via irq_type() on
         IrqVectorRegistration and IrqVector, returning PCI_IRQ_MSIX,
         PCI_IRQ_MSI, or PCI_IRQ_INTX.
       - Mark pci::Device refcount methods inline

   - Serdev:
       - Add Rust abstractions for the serial device bus, including
         serdev::Driver trait, serdev::Device wrapping struct
         serdev_device, and serdev::Adapter implementing
         RegistrationOps. Includes a sample driver. Markus Probst takes
         over as serdev maintainer for both C and Rust code

   - Misc:
       - Split ForLt into a base trait (providing the Of<'a> GAT) and an
         unsafe CovariantForLt subtrait guaranteeing covariance,
         enabling invariant types (e.g. those containing Mutex<&'bound T>)
         to participate in the ForLt abstraction.
       - Fix Coherent read past EOF returning -ERANGE instead of zero.
       - Fix firmware example UB by avoiding null-pointer ARef

  misc:
   - Avoid iattr allocation in kernfs listxattr by using
     kernfs_iattrs_noalloc().
   - Unregister SoC bus on early device registration failure.
   - Remove unused DMA_FENCE_TRACE Kconfig symbol.
   - Fix /sys/module path in comment.
   - Refactor ISA bus init to remove nested blocks.
   - Remove redundant nodemask clears in numa_init().
   - Add kernel-doc for fwnode_operations and sys_soc.h, mark
     internal property data as private for kernel-doc, and add
     property.h/fwnode.h to driver-api infrastructure docs.
   - Add MAINTAINERS entry for sys_soc.h"

* tag 'driver-core-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (129 commits)
  rust: pci: expose the allocated interrupt type
  PCI: Add pci_irq_type() to query the allocated interrupt type
  rust: pci: remove request_irq() and request_threaded_irq() from Device
  rust: pci: resolve IRQ in index() and embed IrqRequest in IrqVector
  rust: pci: convert IrqVectorRegistration to a lifetime-managed owning type
  kernfs: avoid iattr allocation in listxattr
  rust: serdev: use ThisModule::as_ptr() instead of field access
  ACPI/IORT: use platform_device_set_fwnode()
  ACPI/APMT: use platform_device_set_fwnode()
  firmware_loader: do not queue completed sysfs fallback requests
  rust: pci: Mark Device refcount methods inline
  rust: irq: make Registration compatible with lifetime-bound drivers
  rust: net/phy: remove expansion from doc
  rust: dma: return zero for Coherent reads past EOF
  rust: io: register: use path fragment for alias destination
  rust: io: register: remove unused rule arguments
  rust: io: register: dispatch shortcut rules internally
  MAINTAINERS: add sys_soc.h to DRIVER CORE
  rust: debugfs: remove unsafe blocks from traits impl for Vec
  rust: debugfs: migrate debugfs traits requirements to zerocopy
  ...
2026-08-19 10:42:18 -07:00
Alvin Sun 0752a2e96e rust: module: move module types into module.rs
Move `Module`, `InPlaceModule`, `ModuleMetadata` and `ThisModule` from
`lib.rs` into a new `rust/kernel/module.rs`. Re-export them from `lib.rs`
to avoid tree-wide changes.

Switch six bus driver registrations from `module.0` to the public
`ThisModule::as_ptr()` accessor, since the field is no longer visible
outside the new `module` submodule.

No functional change.

Assisted-by: opencode:glm-5.2
Suggested-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/all/DJFIQPLOVO4T.1K8T0VZM30LDA@garyguo.net/
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
Link: https://patch.msgid.link/20260811-fix-fops-owner-v10-1-7e71776f9dbe@linux.dev
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-08-12 09:36:26 +02:00
Gary Guo 0b76335e8f rust: driver: store pointers in DeviceId
The common practice in C drivers is to store pointers into `driver_data`
field of device IDs. The Rust code is however currently storing indices
into the fields and then carry a side table that maps the index to
pointers.

It is much simpler to just have `DeviceId` carry the pointer like C code
does. However, just doing so naively would cause a "pointers cannot be cast
to integers during const eval" error, as kernel_ulong_t does not have
provenance while pointers do, and Rust forbids `expose_provenance` during
consteval.

Work around this limitation by wrapping raw IDs in `MaybeUninit`.
`MaybeUninit` is allowed to host arbitrary bytes with or without
provenance, so we can just then use `unsafe` to store a pointer with
provenance there. This has the same effect as changing the C-side
definition to use `void*` instead of `kernel_ulong_t`, but without actually
changing the C side.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260629-id_info-v2-8-56fccbe9c5ef@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-07-30 22:50:15 +02:00
Gary Guo 0deeb4222d rust: driver: remove $module_table_name from module_device_table
Wrap the generated code in a `const _: ()` block to avoid symbol conflict.
This removes the need of creating a new identifier.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260629-id_info-v2-7-56fccbe9c5ef@garyguo.net
[ Consider the serdev code merged in the meantime. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-07-30 22:50:15 +02:00
Gary Guo 1d92f2e8b8 rust: driver: centralize device ID handling
Move the `IdArray` creation from individual buses to be handled by shared
code in `device_id.rs`.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260629-id_info-v2-6-56fccbe9c5ef@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-07-30 22:50:15 +02:00
Gary Guo c7b6e07f83 rust: usb: use Option<&IdInfo> for device ID info
It is possible that ID without driver_data will be passed to the driver,
e.g. `new_id` is used to dynamically create a new ID without data.
Therefore, the driver must be able to handle the case where `driver_data`
is 0. Thus, update the `probe` functions to get `Option`.

The current code cannot tell if the info does not exist or is the first
entry; however this will be achievable once the code is updated to use a
`&'static IdInfo` pointer instead of indices.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260629-id_info-v2-4-56fccbe9c5ef@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-07-30 16:42:34 +02:00
Danilo Krummrich a3f09f8e47 rust: usb: make Driver trait lifetime-parameterized
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 disconnect() 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: Eliot Courtney <ecourtney@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20260525202921.124698-16-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-27 16:23:51 +02:00
Danilo Krummrich 24799831d6 rust: device: make Core and CoreInternal lifetime-parameterized
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>
2026-05-27 16:22:42 +02:00
Danilo Krummrich 3bb1655192 rust: usb: implement Sync for Device<Bound>
Implement Sync for Device<Bound> in addition to Device<Normal>.

Device<Bound> uses the same underlying struct usb_device as
Device<Normal>; Bound is a zero-sized type-state marker that does not
affect thread safety.

This is needed for drivers to store &'bound usb::Device<Bound> in their
private data while remaining Send.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Uwe Kleine-König <ukleinek@kernel.org>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://patch.msgid.link/20260525202921.124698-10-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-27 16:22:41 +02:00
Danilo Krummrich 7fdffdda63 rust: driver: decouple driver private data from driver type
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>
2026-05-27 16:22:41 +02:00
Gary Guo c8a43666ba rust: driver: move 'static bounds to constructor
With the ForeignOwnable lifetime change, the 'static bound is no longer
necessary on the drvdata methods or bus adapter impls. Move it to the
Registration constructor instead.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260525202921.124698-4-dakr@kernel.org
Co-developed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-27 16:22:41 +02:00
Shankari Anand ebbed9d02e rust: usb: Update AlwaysRefCounted imports to use sync::aref
Update call sites in `usb.rs` to import `AlwaysRefCounted`
from `sync::aref` instead of `types`.

This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to sync.

Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Link: https://patch.msgid.link/20260102202714.184223-4-shankari.ak0208@gmail.com
[ Rebase. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-03-15 20:30:29 +01:00
Linus Torvalds 17f8d20093 Merge tag 'usb-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
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
  ...
2026-02-17 09:36:43 -08:00
Danilo Krummrich a995fe1a3a rust: driver: drop device private data post unbind
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 6f61a2637a ("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: 6f61a2637a ("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>
2026-01-16 01:17:29 +01:00
Danilo Krummrich 2ad0f490c2 rust: driver: add DriverData type to the DriverLayout trait
Add an associated type DriverData to the DriverLayout trait indicating
the type of the driver's device private data.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-6-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16 01:17:29 +01:00
Danilo Krummrich c1d4519e1c rust: driver: add DEVICE_DRIVER_OFFSET to the DriverLayout trait
Add an associated const DEVICE_DRIVER_OFFSET to the DriverLayout trait
indicating the offset of the embedded struct device_driver within
Self::DriverType, i.e. the specific driver structs, such as struct
pci_driver or struct platform_driver.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16 01:17:29 +01:00
Danilo Krummrich 0af1a9e462 rust: driver: introduce a DriverLayout trait
The DriverLayout trait describes the layout of a specific driver
structure, such as `struct pci_driver` or `struct platform_driver`.

In a first step, this replaces the associated type RegType of the
RegistrationOps with the DriverLayout::DriverType associated type.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-4-dakr@kernel.org
[ Rename driver::Driver to driver::DriverLayout, as it represents the
  layout of a driver structure rather than the driver structure itself.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16 01:16:44 +01:00
Danilo Krummrich 13f2bd893a rust: usb: use "kernel vertical" style for imports
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
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20260105142123.95030-4-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-07 16:12:48 +01:00
Markus Probst e4addc7cc2 rust: Add trait to convert a device reference to a bus device reference
Implement the `AsBusDevice` trait for converting a `Device` reference to a
bus device reference for all bus devices.

The `AsBusDevice` trait allows abstractions to provide the bus device in
class device callbacks. It must not be used by drivers and is intended for
bus and class device abstractions only.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
Link: https://patch.msgid.link/20251027200547.1038967-2-markus.probst@posteo.de
[ * Remove unused import.
  * Change visibility of AsBusDevice to public.
  * Fix build for USB.
  * Add impl for I2cClient.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18 11:00:51 +13:00
Danilo Krummrich fde40a558d rust: usb: fix broken call to T::disconnect()
A refactoring of Device::drvdata_obtain() broke T::disconnect() in the
USB abstractions.

"""
error[E0599]: no method named `data` found for struct `core::pin::Pin<kbox::Box<T, Kmalloc>>` in the current scope
  --> rust/kernel/usb.rs:92:34
   |
92 |         T::disconnect(intf, data.data());
   |                                  ^^^^ method not found in `core::pin::Pin<kbox::Box<T, Kmalloc>>`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0599`.
make[2]: *** [rust/Makefile:553: rust/kernel.o] Error 1
make[1]: *** [/builddir/build/BUILD/kernel-6.18.0-build/kernel-next-20251103/linux-6.18.0-0.0.next.20251103.436.vanilla.fc44.x86_64/Makefile:1316: prepare] Error 2
make: *** [Makefile:256: __sub-make] Error 2
"""

This slipped through, since the USB abstractions are globally disabled.
However, the USB tree recently enabled them, hence it showed up in
linux-next.

Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/all/1c8afbc0-e888-4702-9e4e-fa8aef0f97ae@leemhuis.info/
Fixes: 6bbaa93912 ("rust: device: narrow the generic of drvdata_obtain()")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://patch.msgid.link/20251103110115.1925072-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-04 00:31:25 +01:00
Danilo Krummrich 6bbaa93912 rust: device: narrow the generic of drvdata_obtain()
Let T be the actual private driver data type without the surrounding
box, as it leaves less room for potential bugs.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 16:40:28 +01:00
Danilo Krummrich 0242623384 rust: driver: let probe() return impl PinInit<Self, Error>
The driver model defines the lifetime of the private data stored in (and
owned by) a bus device to be valid from when the driver is bound to a
device (i.e. from successful probe()) until the driver is unbound from
the device.

This is already taken care of by the Rust implementation of the driver
model. However, we still ask drivers to return a Result<Pin<KBox<Self>>>
from probe().

Unlike in C, where we do not have the concept of initializers, but
rather deal with uninitialized memory, drivers can just return an
impl PinInit<Self, Error> instead.

This contributes to more clarity to the fact that a driver returns it's
device private data in probe() and the Rust driver model owns the data,
manages the lifetime and - considering the lifetime - provides (safe)
accessors for the driver.

Hence, let probe() functions return an impl PinInit<Self, Error> instead
of Result<Pin<KBox<Self>>>.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-21 18:40:48 +02:00
Danilo Krummrich 22d693e45d rust: usb: keep usb::Device private for now
The USB abstractions target to support USB interface drivers.

While internally the abstraction has to deal with the interface's parent
USB device, there shouldn't be a need for users to deal with the parent
USB device directly.

Functions, such as for preparing and sending USB URBs, can be
implemented for the usb::Interface structure directly. Whether this
internal implementation has to deal with the parent USB device can
remain transparent to USB interface drivers.

Hence, keep the usb::Device structure private for now, in order to avoid
confusion for users and to make it less likely to accidentally expose
APIs with unnecessary indirections.

Should we start supporting USB device drivers, or need it for any other
reason we do not foresee yet, it should be trivial to make it public
again.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250925190400.144699-2-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-26 08:09:08 +02:00
Danilo Krummrich f12140f21a rust: usb: don't retain device context for the interface parent
When deriving the parent USB device (struct usb_device) from a USB
interface (struct usb_interface), do not retain the device context.

For the Bound context, as pointed out by Alan in [1], it is not
guaranteed that the parent USB device is always bound when the interface
is bound.

The bigger problem, however, is that we can't infer the Core context,
since eventually it indicates that the device lock is held. However,
there is no guarantee that if the device lock of the interface is held,
also the device lock of the parent USB device is held.

Hence, fix this by not inferring any device context information; while
at it, fix up the (affected) safety comments.

Link: https://lore.kernel.org/all/0ff2a825-1115-426a-a6f9-df544cd0c5fc@rowland.harvard.edu/ [1]
Fixes: e7e2296b0e ("rust: usb: add basic USB abstractions")
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250925190400.144699-1-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-26 08:09:08 +02:00
Daniel Almeida e7e2296b0e rust: usb: add basic USB abstractions
Add basic USB abstractions, consisting of usb::{Device, Interface,
Driver, Adapter, DeviceId} and the module_usb_driver macro. This is the
first step in being able to write USB device drivers, which paves the
way for USB media drivers - for example - among others.

This initial support will then be used by a subsequent sample driver,
which constitutes the only user of the USB abstractions so far.

Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://lore.kernel.org/r/20250825-b4-usb-v1-1-7aa024de7ae8@collabora.com
[ force USB = y for now - gregkh ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-24 13:13:04 +02:00