mbox series

[v6,0/6] rust: Add ACPI match table support for Rust drivers

Message ID 20250613133517.1229722-1-igor.korotin.linux@gmail.com
Headers show
Series rust: Add ACPI match table support for Rust drivers | expand

Message

Igor Korotin June 13, 2025, 1:35 p.m. UTC
This patch series introduces support for ACPI match tables in Rust 
drivers.

Currently, Rust abstractions support only Open Firmware (OF) device 
matching. This series extends the driver model to support ACPI-based 
matching, enabling Rust drivers to bind to ACPI-described devices.

Changes include:
  - A new `acpi::DeviceId` abstraction for working with 
   `struct acpi_device_id`.
  - Updates to the core `Adapter` trait and `platform::Driver` to support
    optional ACPI ID tables.
  - A sample implementation in the Rust platform driver, demonstrating 
    multi-bus matching.

This is especially useful for writing drivers that work across platforms 
using both OF and ACPI.

Tested using QEMU with a custom SSDT that creates an ACPI device matching
the sample Rust platform driver.

Igor Korotin (6):
  rust: acpi: add `acpi::DeviceId` abstraction
  rust: driver: Consolidate `Adapter::of_id_info` methods using `#[cfg]`
  rust: driver: Add ACPI id table support to Adapter trait
  rust: platform: Set `OF_ID_TABLE` default to `None` in `Driver` trait
  rust: platform: Add ACPI match table support to `Driver` trait
  samples: rust: add ACPI match table example to platform driver

Changelog
---------
v6:
 - Moved set `Driver::OF_ID_TABLE` default to `None` to a separate commit 
 - Removed out of scope change related to cpufreq driver.
 - Link to v5: https://lore.kernel.org/rust-for-linux/20250611174034.801460-1-igor.korotin.linux@gmail.com/
v5:
 - Got rid of unnecessary consolidation of `Adapter::acpi_id_info` methods.
   Instead, firstly made consolidation of `Adapter::of_id_info`, then
   `Adapter::acpi_id_info` is added using the same pattern. 
 - Set `Adapter::OF_ID_TABLE` and `Adapter::ACPI_ID_TABLE` as None by 
   default. 
 - Removed `Adapter::OF_ID_TABLE`/`Adapter::ACPI_ID_TABLE` initialization
   example due to irrelevance.
 - Removed extra `of` dependency and `Adapter::OF_ID_TABLE` initialization 
   in cpufreq driver.
 - Link to v4: https://lore.kernel.org/rust-for-linux/20250610145234.235005-1-igor.korotin.linux@gmail.com/
v4:
 - Fixed code example for `trait Adapter` in platform.rs 
 - Fixed driver implementation example in rust_driver_platform.rs and moved
   it to `trait Adapter` in platform.rs per Danilo Krummrich's suggestion.
 - Consolidated `Adapter::of_id_info` and `Adapter::acpi_id_info` methods using
   `#[cfg]` per Benno Lossin's suggestion.
 - Link to v3: https://lore.kernel.org/rust-for-linux/20250606170341.3880941-1-igor.korotin.linux@gmail.com/
v3:
 - Removed fwnode type check in `Adapter::id_info` per Greg's and Danilo's
   comments
 - Removed `is_of_node` rust helper, due to unnecessity. 
 - Fixed example code in `rust_driver_platform.rs` per Danilo's comment
 - Added an instruction of testing ACPI using QEMU with a custom SSDT
 - Fixed minor code formatting issues.
 - Link to v2: https://lore.kernel.org/rust-for-linux/20250605161956.3658374-1-igor.korotin.linux@gmail.com/
v2:
 - Removed misleading comment in `acpi::DeviceID` implementation. 
 - Removed unnecessary casting in `acpi::DeviceID::new`.
 - Moved `pub mod acpi` to correct alphabetical position in `rust/kernel/lib.rs`.
 - Link to v1: https://lore.kernel.org/rust-for-linux/20250530123815.1766726-1-igor.korotin.linux@gmail.com/

 MAINTAINERS                          |  1 +
 rust/bindings/bindings_helper.h      |  1 +
 rust/kernel/acpi.rs                  | 61 +++++++++++++++++++++
 rust/kernel/driver.rs                | 81 +++++++++++++++++++++-------
 rust/kernel/lib.rs                   |  1 +
 rust/kernel/platform.rs              | 29 ++++++++--
 samples/rust/rust_driver_platform.rs | 71 +++++++++++++++++++++++-
 7 files changed, 221 insertions(+), 24 deletions(-)
 create mode 100644 rust/kernel/acpi.rs


base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494

Comments

Danilo Krummrich June 16, 2025, 8:03 p.m. UTC | #1
On Fri, Jun 13, 2025 at 02:38:42PM +0100, Igor Korotin wrote:
> +impl DeviceId {
> +    const ACPI_ID_LEN: usize = 16;
> +
> +    /// Create a new device id from an ACPI 'id' string.
> +    pub const fn new(id: &'static CStr) -> Self {
> +        assert!(id.len() <= Self::ACPI_ID_LEN, "ID exceeds 16 bytes");

Please use build_assert!() for this check.

> +        let src = id.as_bytes_with_nul();
> +        // Replace with `bindings::acpi_device_id::default()` once stabilized for `const`.
> +        // SAFETY: FFI type is valid to be zero-initialized.
> +        let mut acpi: bindings::acpi_device_id = unsafe { core::mem::zeroed() };
> +        let mut i = 0;
> +        while i < src.len() {
> +            acpi.id[i] = src[i];
> +            i += 1;
> +        }
> +
> +        Self(acpi)
> +    }
> +}