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8d84b32075
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>
65 lines
2 KiB
Rust
65 lines
2 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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//! Device Tree / Open Firmware abstractions.
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use crate::{
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bindings,
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device_id::{RawDeviceId, RawDeviceIdIndex},
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prelude::*,
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};
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/// IdTable type for OF drivers.
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pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>;
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/// An open firmware device id.
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#[repr(transparent)]
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#[derive(Clone, Copy)]
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pub struct DeviceId(bindings::of_device_id);
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// SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `struct of_device_id` and
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// does not add additional invariants, so it's safe to transmute to `RawType`.
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unsafe impl RawDeviceId for DeviceId {
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type RawType = bindings::of_device_id;
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}
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// SAFETY: `DRIVER_DATA_OFFSET` is the offset to the `data` field.
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unsafe impl RawDeviceIdIndex for DeviceId {
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const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::of_device_id, data);
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fn index(&self) -> usize {
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self.0.data as _
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}
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}
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impl DeviceId {
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/// Create a new device id from an OF 'compatible' string.
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pub const fn new(compatible: &'static CStr) -> Self {
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let src = compatible.as_bytes_with_nul();
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// Replace with `bindings::of_device_id::default()` once stabilized for `const`.
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// SAFETY: FFI type is valid to be zero-initialized.
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let mut of: bindings::of_device_id = unsafe { core::mem::zeroed() };
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// TODO: Use `clone_from_slice` once the corresponding types do match.
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let mut i = 0;
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while i < src.len() {
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of.compatible[i] = src[i] as _;
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i += 1;
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}
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Self(of)
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}
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}
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/// Create an OF `IdTable` with an "alias" for modpost.
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#[macro_export]
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macro_rules! of_device_table {
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($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => {
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const $table_name: $crate::device_id::IdArray<
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$crate::of::DeviceId,
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$id_info_type,
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{ $table_data.len() },
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> = $crate::device_id::IdArray::new($table_data);
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$crate::module_device_table!("of", $module_table_name, $table_name);
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};
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}
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