On Tue, Oct 22, 2024 at 11:33 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> `of::DeviceId` is an abstraction around `struct of_device_id`.
>
> This is used by subsequent patches, in particular the platform bus
> abstractions, to create OF device ID tables.
>
> Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> rust/bindings/bindings_helper.h | 1 +
> rust/kernel/lib.rs | 1 +
> rust/kernel/of.rs | 63 +++++++++++++++++++++++++++++++++
> 4 files changed, 66 insertions(+)
> create mode 100644 rust/kernel/of.rs
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d9c512a3e72b..87eb9a7869eb 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17340,6 +17340,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git
> F: Documentation/ABI/testing/sysfs-firmware-ofw
> F: drivers/of/
> F: include/linux/of*.h
> +F: rust/kernel/of.rs
> F: scripts/dtc/
> F: tools/testing/selftests/dt/
> K: of_overlay_notifier_
> diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
> index cd4edd6496ae..312f03cbdce9 100644
> --- a/rust/bindings/bindings_helper.h
> +++ b/rust/bindings/bindings_helper.h
> @@ -15,6 +15,7 @@
> #include <linux/firmware.h>
> #include <linux/jiffies.h>
> #include <linux/mdio.h>
> +#include <linux/of_device.h>
> #include <linux/pci.h>
> #include <linux/phy.h>
> #include <linux/refcount.h>
> diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
> index 3ec690eb6d43..5946f59f1688 100644
> --- a/rust/kernel/lib.rs
> +++ b/rust/kernel/lib.rs
> @@ -51,6 +51,7 @@
> pub mod list;
> #[cfg(CONFIG_NET)]
> pub mod net;
> +pub mod of;
> pub mod page;
> pub mod prelude;
> pub mod print;
> diff --git a/rust/kernel/of.rs b/rust/kernel/of.rs
> new file mode 100644
> index 000000000000..a37629997974
> --- /dev/null
> +++ b/rust/kernel/of.rs
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +//! Open Firmware abstractions.
> +//!
> +//! C header: [`include/linux/of_*.h`](srctree/include/linux/of_*.h)
> +
> +use crate::{bindings, device_id::RawDeviceId, prelude::*};
> +
> +/// An open firmware device id.
> +#[derive(Clone, Copy)]
> +pub struct DeviceId(bindings::of_device_id);
> +
> +// SAFETY:
> +// * `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and does not add
> +// additional invariants, so it's safe to transmute to `RawType`.
Your #[repr(transparent)] marker is missing.
> +// * `DRIVER_DATA_OFFSET` is the offset to the `data` field.
> +unsafe impl RawDeviceId for DeviceId {
> + type RawType = bindings::of_device_id;
> +
> + const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::of_device_id, data);
> +
> + fn index(&self) -> usize {
> + self.0.data as _
> + }
> +}
> +
> +impl DeviceId {
> + /// Create a new device id from an OF 'compatible' string.
> + pub const fn new(compatible: &'static CStr) -> Self {
Since you make a copy of `compatible`, you don't need 'static.
> + let src = compatible.as_bytes_with_nul();
> + // Replace with `bindings::of_device_id::default()` once stabilized for `const`.
> + // SAFETY: FFI type is valid to be zero-initialized.
> + let mut of: bindings::of_device_id = unsafe { core::mem::zeroed() };
> +
> + let mut i = 0;
> + while i < src.len() {
> + of.compatible[i] = src[i] as _;
> + i += 1;
> + }
> +
> + Self(of)
> + }
> +
> + /// The compatible string of the embedded `struct bindings::of_device_id` as `&CStr`.
> + pub fn compatible<'a>(&self) -> &'a CStr {
This should probably be:
pub fn compatible(&self) -> &CStr {
Right now, the returned CStr is not tied to self at all, even though
it points inside `self`.
Alice
