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 B258210E0; Wed, 19 Mar 2025 20:31:35 +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=1742416295; cv=none; b=ctLoBGdYGQiry/peqXLvbe/ZHFnPOIl20TNsgs+UzlsI/Py/VLTDxSDJbA9i8kQYBZobuHNVnjEkKWlyaggg7l3rchywlMqKcejyN70oibA/4QBBsySEe4iqe136BKk8z/5eLy0ZeG0yj/OUpCFapfsDIMd7m6cnqqKLmqxhyos= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742416295; c=relaxed/simple; bh=8dSbmv6RUXno2wJjkEPEkGjO99eu0MpD6e+agTv04vE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BJHr/8IBPRv3cRwawDtP03Y+fJxgDwoAVbcUghtvoIpJ90D8e1WuCg3dZDtVDyi2OaBhrAZez8ana0ktbrCohTt6+VvGLxrA0f7kB22RByxoy6AHokB6P6BUsajKlTxYAXJCpJ+F0yZYExTBkYdWG7mnlrbRJ0ZSqm9zlGllyZM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GdMiZXcU; 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="GdMiZXcU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 012C9C4CEE4; Wed, 19 Mar 2025 20:31:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742416295; bh=8dSbmv6RUXno2wJjkEPEkGjO99eu0MpD6e+agTv04vE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GdMiZXcUBwYVxbdCg/A4RqfgFZb7QwFmp96v/B5fdXrFMCap6wzgWr+ASfnY71f0R fkEo3oZtjuJFGqnS8TwpPrV/5Q0t3Ccgm4dWUrdWitH6gCIV2+Aua/wyB+sEpdZCXT KWuxYZPGHC+BMll1ksUN70PAuEFsOpXLzRDvhsXeWxXJsL6UD3YMlNIMBd4Yl/rfqy vVdJ1inQ2E3XHGscx79qSVMNx2i/KT5F++PW1pOd4jXDf57xmRFcNknLni7qPsXQKM 0bh2eyNsELxhE2mpU+7AR/RiFvDeGF5iVhRAuc3x3vfPbVSr7jv/hfOh1NZnS1Zjnq P40uxgUVCTKOw== From: Danilo Krummrich To: bhelgaas@google.com, gregkh@linuxfoundation.org, rafael@kernel.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu Cc: linux-pci@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Danilo Krummrich Subject: [PATCH 4/4] rust: platform: impl TryFrom<&Device> for &platform::Device Date: Wed, 19 Mar 2025 21:30:28 +0100 Message-ID: <20250319203112.131959-5-dakr@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250319203112.131959-1-dakr@kernel.org> References: <20250319203112.131959-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Implement TryFrom<&device::Device> for &Device. This allows us to get a &platform::Device from a generic &Device in a safe way; the conversion fails if the device' bus type does not match with the platform bus type. Signed-off-by: Danilo Krummrich --- rust/kernel/platform.rs | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs index e37531bae8e9..c17fc6e7c596 100644 --- a/rust/kernel/platform.rs +++ b/rust/kernel/platform.rs @@ -5,7 +5,7 @@ //! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h) use crate::{ - bindings, device, driver, + bindings, container_of, device, driver, error::{to_result, Result}, of, prelude::*, @@ -17,7 +17,7 @@ use core::{ marker::PhantomData, ops::Deref, - ptr::{addr_of_mut, NonNull}, + ptr::{addr_of, addr_of_mut, NonNull}, }; /// An adapter for the registration of platform drivers. @@ -234,6 +234,24 @@ fn as_ref(&self) -> &device::Device { } } +impl TryFrom<&device::Device> for &Device { + type Error = kernel::error::Error; + + fn try_from(dev: &device::Device) -> Result { + if dev.bus_type_raw() != addr_of!(bindings::platform_bus_type) { + return Err(EINVAL); + } + + // SAFETY: We've just verified that the bus type of `dev` equals + // `bindings::platform_bus_type`, hence `dev` must be embedded in a valid + // `struct platform_device`. + let pdev = unsafe { container_of!(dev.as_raw(), bindings::platform_device, dev) }; + + // SAFETY: `pdev` is a valid pointer to a `struct platform_device`. + Ok(unsafe { &*pdev.cast() }) + } +} + // SAFETY: A `Device` is always reference-counted and can be released from any thread. unsafe impl Send for Device {} -- 2.48.1