From patchwork Thu Mar 20 22:27:44 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 14024601 X-Patchwork-Delegate: bhelgaas@google.com 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 A61F71B422A; Thu, 20 Mar 2025 22:28:36 +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=1742509716; cv=none; b=YpboVLBGldkvGcbQuooza2RajZo6FQl5eUJ21KltfYEcxMaxKAdBOZIs/cZHS942eltScH4l1a7DzkaQqUk5tEdSlzly1V5gk5/DQeChfWPHINU7d2jlhiefTE2ffRVwMisH1gJ4F6wthKGwCLk3AzCqPpSehgnLnlh9uBnvZJo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742509716; c=relaxed/simple; bh=SQZafYFP1JrZU2z5rRL7rGUnXA9Ni4v/58cfQdkfXYM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gGRvz1gdN2noXuYQ8NjDIHaOR81y1x3YRXZS4O8Vv5TxdtlmvN7lzI1vzO+vWI040VcsftC8kBTD2rGCW8KykQUaSTWNClIqSuheaUXMwSaYydJLEJ/ZhaUMg92MJpOgGnu/LX8c2Ngvb6XoUlFs7MbJkY/LsvKKV6rMwPnh9+w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LSq/oMcD; 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="LSq/oMcD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CA72C4CEDD; Thu, 20 Mar 2025 22:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742509716; bh=SQZafYFP1JrZU2z5rRL7rGUnXA9Ni4v/58cfQdkfXYM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LSq/oMcDW+enuh/46SbHigMnLYowagFmQYDdPVo8zfcXTE8TUMy4rax0NlGxd3hx4 4UTuey/6goNyoOYCEa3D3L2wror774GObVbo7hFlRxfQK7BVLaocRcVtfPypMPTF/S GMn62Og6Jct4tiYa3wcG+1OuftWMBwlcIpaAMuLxfVvWjhP8mJXsSFzptisIE9cnON DSNVIFvBQDfVQT2jIYpDVDAMzGyoSAqG8RsZzMHjF9ETwMr+GDjjULSNvlXap/qFam SCneUP1p7XI1K57kLjhF84agQsDBtxe55yD2MHRoMvjElh8+vaezqO2QJOcZuTO1+7 RVEncmCmwp9ww== 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 v2 2/4] rust: device: implement bus_type_raw() Date: Thu, 20 Mar 2025 23:27:44 +0100 Message-ID: <20250320222823.16509-3-dakr@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250320222823.16509-1-dakr@kernel.org> References: <20250320222823.16509-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement bus_type_raw(), which returns a raw pointer to the device' struct bus_type. This is useful for bus devices, to implement the following trait. impl TryFrom<&Device> for &pci::Device With this a caller can try to get the bus specific device from a generic device in a safe way. try_from() will only succeed if the generic device' bus type pointer matches the pointer of the bus' type. Reviewed-by: Alice Ryhl Signed-off-by: Danilo Krummrich Reviewed-by: Benno Lossin --- rust/kernel/device.rs | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index f6bdc2646028..1b554fdd93e9 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -80,6 +80,16 @@ pub fn parent<'a>(&self) -> Option<&'a Self> { } } + /// Returns a raw pointer to the device' bus type. + #[expect(unused)] + pub(crate) fn bus_type_raw(&self) -> *const bindings::bus_type { + // SAFETY: + // - By the type invariants, `self.as_raw()` is a valid pointer to a `struct device`. + // - `dev->bus` is a pointer to a `const struct bus_type`, which is only ever set at device + // creation. + unsafe { (*self.as_raw()).bus } + } + /// Convert a raw C `struct device` pointer to a `&'a Device`. /// /// # Safety