Extend the `Adapter` trait to support ACPI device identification.
This mirrors the existing Open Firmware (OF) support (`of_id_table`) and
enables Rust drivers to match and retrieve ACPI-specific device data
when `CONFIG_ACPI` is enabled.
To avoid breaking compilation, a stub implementation of `acpi_id_table()`
is added to the Platform adapter; the full implementation will be provided
in a subsequent patch.
---
rust/bindings/bindings_helper.h | 1 +
rust/kernel/driver.rs | 58 ++++++++++++++++++++++++++++++---
rust/kernel/platform.rs | 5 +++
3 files changed, 60 insertions(+), 4 deletions(-)
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index e0bcd130b494..d974fc6c141f 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -6,6 +6,7 @@
* Sorted alphabetically.
*/
+#include <linux/acpi.h>
#include <kunit/test.h>
#include <linux/blk-mq.h>
#include <linux/blk_types.h>
diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs
index ec9166cedfa7..d4098596188a 100644
--- a/rust/kernel/driver.rs
+++ b/rust/kernel/driver.rs
@@ -6,7 +6,7 @@
//! register using the [`Registration`] class.
use crate::error::{Error, Result};
-use crate::{device, of, str::CStr, try_pin_init, types::Opaque, ThisModule};
+use crate::{device, of, acpi, str::CStr, try_pin_init, types::Opaque, ThisModule};
use core::pin::Pin;
use pin_init::{pin_data, pinned_drop, PinInit};
@@ -141,6 +141,38 @@ pub trait Adapter {
/// The type holding driver private data about each device id supported by the driver.
type IdInfo: 'static;
+ /// The [`acpi::IdTable`] of the corresponding driver
+ fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>>;
+
+ /// Returns the driver's private data from the matching entry in the [`acpi::IdTable`], if any.
+ ///
+ /// If this returns `None`, it means there is no match with an entry in the [`acpi::IdTable`].
+ #[cfg(CONFIG_ACPI)]
+ fn acpi_id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
+ let table = Self::acpi_id_table()?;
+
+ // SAFETY:
+ // - `table` has static lifetime, hence it's valid for read,
+ // - `dev` is guaranteed to be valid while it's alive, and so is `pdev.as_ref().as_raw()`.
+ let raw_id = unsafe { bindings::acpi_match_device(table.as_ptr(), dev.as_raw()) };
+
+ if raw_id.is_null() {
+ None
+ } else {
+ // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and
+ // does not add additional invariants, so it's safe to transmute.
+ let id = unsafe { &*raw_id.cast::<acpi::DeviceId>() };
+
+ Some(table.info(<acpi::DeviceId as crate::device_id::RawDeviceId>::index(id)))
+ }
+ }
+
+ #[cfg(not(CONFIG_ACPI))]
+ #[allow(missing_docs)]
+ fn acpi_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> {
+ None
+ }
+
/// The [`of::IdTable`] of the corresponding driver.
fn of_id_table() -> Option<of::IdTable<Self::IdInfo>>;
@@ -178,9 +210,27 @@ fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> {
/// If this returns `None`, it means that there is no match in any of the ID tables directly
/// associated with a [`device::Device`].
fn id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
- let id = Self::of_id_info(dev);
- if id.is_some() {
- return id;
+ // SAFETY: `id_info` is called from `Adapter::probe_callback` with a valid `dev` argument.
+ let fwnode = unsafe{ (*dev.as_raw()).fwnode};
+
+ // SAFETY: `bindings::is_acpi_device_node` checks `fwnode` before accessing `fwnode->ops`,
+ // and only compares it with the address of `acpi_device_fwnode_ops`.
+ if unsafe { bindings::is_acpi_device_node(fwnode) } {
+ let id = Self::acpi_id_info(dev);
+
+ if id.is_some() {
+ return id;
+ }
+ }
+
+ // SAFETY: `bindings::is_of_node` checks `fwnode` before accessing `fwnode->ops`,
+ // and only compares it with the address of `of_fwnode_ops`.
+ if unsafe { bindings::is_of_node(fwnode) } {
+ let id = Self::of_id_info(dev);
+
+ if id.is_some() {
+ return id;
+ }
}
None
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index fd4a494f30e8..3cc9fe6ccfcf 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -5,6 +5,7 @@
//! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h)
use crate::{
+ acpi,
bindings, device, driver,
error::{to_result, Result},
of,
@@ -95,6 +96,10 @@ impl<T: Driver + 'static> driver::Adapter for Adapter<T> {
fn of_id_table() -> Option<of::IdTable<Self::IdInfo>> {
T::OF_ID_TABLE
}
+
+ fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>> {
+ None
+ }
}
/// Declares a kernel module that exposes a single platform driver.
--
2.43.0
