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>
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>
All types in `bindings` implement `Zeroable` if they can, so use
`pin_init::zeroed` instead of relying on `unsafe` code.
If this ends up not compiling in the future, something in bindgen or on
the C side changed and is most likely incorrect.
Link: https://github.com/Rust-for-Linux/linux/issues/1189
Suggested-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Siyuan Huang <huangsiyuan@kylinos.cn>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://patch.msgid.link/20251020031204.78917-1-huangsiyuan@kylinos.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Prepare for `core::ffi::CStr` taking the place of `kernel::str::CStr` by
avoid methods that only exist on the latter.
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Introduce a new trait `RawDeviceIdIndex`, which extends `RawDeviceId`
to provide support for device ID types that include an index or
context field (e.g., `driver_data`). This separates the concerns of
layout compatibility and index-based data embedding, and allows
`RawDeviceId` to be implemented for types that do not contain a
`driver_data` field. Several such structures are defined in
include/linux/mod_devicetable.h.
Refactor `IdArray::new()` into a generic `build()` function, which
takes an optional offset. Based on the presence of `RawDeviceIdIndex`,
index writing is conditionally enabled. A new `new_without_index()`
constructor is also provided for use cases where no index should be
written.
This refactoring is a preparation for enabling the PHY abstractions to
use the RawDeviceId trait.
The changes to acpi.rs and driver.rs were made by Danilo.
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250711040947.1252162-2-fujita.tomonori@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
A future Clippy warning, `clippy::as_underscore`, is getting enabled in
parallel in the rust-next tree:
error: using `as _` conversion
--> rust/kernel/acpi.rs:25:9
|
25 | self.0.driver_data as _
| ^^^^^^^^^^^^^^^^^^^^^^-
| |
| help: consider giving the type explicitly: `usize`
The type is already `ulong`, which nowadays is always `usize`, so the
cast is unneeded. Thus remove it, which in turn will avoid the warning
in the future.
Other abstractions of device tables do not use a cast here either.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://lore.kernel.org/r/20250701174656.62205-1-ojeda@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`acpi::DeviceId` is an abstraction around `struct acpi_device_id`.
Enable drivers to build ACPI device ID tables, to be consumed by the
corresponding bus abstractions, such as platform or I2C.
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20250620152425.285683-1-igor.korotin.linux@gmail.com
[ Always inline DeviceId::new() and use &'static CStr; slightly reword
commit message. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
