From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 05A6D22F16E; Fri, 30 May 2025 14:43:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748616195; cv=none; b=YxTVYZFCIUVXNfTz+/GQqxJIbzx3ujwo0e0Mkqew3+mVbQRDTy0G4PQJyBbYUbL4vsjxtSh4PvYYaS+oyFC86vRduuvAWZiYby1lfphDzCfSBMDvP30L720t0UCZjVHvDCwVdKsZgjU3xcLER+ObketRrG0upVHr1yg1a4OlS9I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748616195; c=relaxed/simple; bh=mY/b1aYZ4zd+kOTmSV/9uLnE2/GpBj9H7mUyqgsW6Bg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kMyLxOWXdWFQUFo/rMtdQaePRBtI2tTDoT5aEA7xxiT9VvjSGxRiaXfPlBn1nasBXA/8gDygXYmAu3i8rVxM6q2nAuLKDZ9m5pFYesTpWSO3S+gYyymFq2GklAAgIoIkFcupZxQcr8glbeBMoAg7xt19Chpsc5l8ZPVyEX8Bpvw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q2tGI9pC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Q2tGI9pC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5390FC4CEE9; Fri, 30 May 2025 14:43:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748616194; bh=mY/b1aYZ4zd+kOTmSV/9uLnE2/GpBj9H7mUyqgsW6Bg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Q2tGI9pCPo8JExw4qGa00gTsqQs4sZa4Zx3V77oGvTMzuJ5B9MkkW+8XR3Wr0XrE0 Alm0r/RK4uIZguw/DyZP2VC59npUKO8qhOfMntAV7ZqROxgY8liBvnfVLXLdDcVCZs sbP6ZFXGI8szVTZA2KOQqvzRfJ7JJqBudpelzGpz9iNVDWB4C23iUGkMkZqM3YIbRj UkgiDZdO5ugRT5kMWiPiD0y/CExK2Apb6zlVZ4o461WaqpWyYa7k+oPpv5wF/5JT8/ Wf0+O3jOgCKW55pfpLHi1r3+9dZLXHgNwpFD153bsbfO2XONDvRneDwZwFLIjYVqGk NjQhB7ZFH24wA== Date: Fri, 30 May 2025 16:43:08 +0200 From: Danilo Krummrich To: Igor Korotin Cc: "Rafael J . Wysocki" , Len Brown , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , linux-acpi@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rust: acpi: add `acpi::DeviceId` abstraction Message-ID: References: <20250530123815.1766726-1-igor.korotin.linux@gmail.com> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250530123815.1766726-1-igor.korotin.linux@gmail.com> On Fri, May 30, 2025 at 01:38:06PM +0100, Igor Korotin wrote: > `acpi::DeviceId` is an abstraction around `struct acpi_device_id`. > > This is used by subsequent patches, in particular the i2c driver > abstractions, to create ACPI device ID tables. > > Signed-off-by: Igor Korotin As Greg mentioned it would be nice to see the subsequent patches. Also, for this to be useful you need to implement the generic glue code in rust/kernel/driver.rs in the generic Adapter trait. You also may want to connect it to the platform bus abstraction, just like the OF bindings are, since I assume that's the bus you care about? > --- > MAINTAINERS | 1 + > rust/kernel/acpi.rs | 63 +++++++++++++++++++++++++++++++++++++++++++++ > rust/kernel/lib.rs | 1 + > 3 files changed, 65 insertions(+) > create mode 100644 rust/kernel/acpi.rs > > diff --git a/MAINTAINERS b/MAINTAINERS > index b659fb27ab63..5f8dfae08454 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -302,6 +302,7 @@ F: include/linux/acpi.h > F: include/linux/fwnode.h > F: include/linux/fw_table.h > F: lib/fw_table.c > +F: rust/kernel/acpi.rs > F: tools/power/acpi/ > > ACPI APEI > diff --git a/rust/kernel/acpi.rs b/rust/kernel/acpi.rs > new file mode 100644 > index 000000000000..bbd38910736c > --- /dev/null > +++ b/rust/kernel/acpi.rs > @@ -0,0 +1,63 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +//! Advanced Configuration and Power Interface abstractions. > + > +use crate::{bindings, device_id::RawDeviceId, prelude::*}; > + > +/// IdTable type for ACPI drivers. > +pub type IdTable = &'static dyn kernel::device_id::IdTable; > + > +/// An ACPI device id. > +#[repr(transparent)] > +#[derive(Clone, Copy)] > +pub struct DeviceId(bindings::acpi_device_id); > + > +// SAFETY: > +// * `DeviceId` is a `#[repr(transparent)` wrapper of `struct acpi_device_id` and does not add > +// additional invariants, so it's safe to transmute to `RawType`. > +// * `DRIVER_DATA_OFFSET` is the offset to the `data` field. > +unsafe impl RawDeviceId for DeviceId { > + type RawType = bindings::acpi_device_id; > + > + const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::acpi_device_id, driver_data); > + > + fn index(&self) -> usize { > + self.0.driver_data as _ > + } > +} > + > +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"); > + 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() }; The patch did not land yet, but for this there's the following improvement upcoming: https://lore.kernel.org/rust-for-linux/20250523145125.523275-13-lossin@kernel.org/ > + // TODO: Use `clone_from_slice` once the corresponding types do match. clone_from_slice() can't be used from const context, this comment is wrong in of.rs (where you probably copied it from). > + let mut i = 0; > + while i < src.len() { > + acpi.id[i] = src[i] as _; You can drop this cast, it shouldn't be needed anymore. > + i += 1; > + } > + > + Self(acpi) > + } > +} > + > +/// Create an ACPI `IdTable` with an "alias" for modpost. > +#[macro_export] > +macro_rules! acpi_device_table { > + ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => { > + const $table_name: $crate::device_id::IdArray< > + $crate::acpi::DeviceId, > + $id_info_type, > + { $table_data.len() }, > + > = $crate::device_id::IdArray::new($table_data); > + > + $crate::module_device_table!("acpi", $module_table_name, $table_name); > + }; > +} > + > diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs > index 15c5f72976cd..05f1d3870bf7 100644 > --- a/rust/kernel/lib.rs > +++ b/rust/kernel/lib.rs > @@ -78,6 +78,7 @@ > #[cfg(CONFIG_NET)] > pub mod net; > pub mod of; > +pub mod acpi; As mentioned by Greg, please keep this ordered.