From patchwork Fri Mar 21 21:47:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 14026072 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 212DE233725; Fri, 21 Mar 2025 21:48:36 +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=1742593717; cv=none; b=uq7AdFjr0eWxSq2TK9dgxmx5uRXWwHCVFbgdR51mkQlQvxLaAWaflX5PDfzKtyCJ6woG1EnrsDEOaIN0to0UAmg2n7Sx+HTI8Hq6gZWxCr/xfgop2CqDzSVSytfuyTjh+mnmTAbfiuxOVhQ+O4eHCQH3ii47DrxhjsoP4lPrsIo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742593717; c=relaxed/simple; bh=MKwm/fHil0GDCiiaBpnQB8YlsfUYdX6rYlCKMcY4+DY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EA3UUjlTCSkkBISbnpVQjfTKEO5RVTvrvQRyCvfwBWzuqYIGvKvCQ1fJvK30VEGGjX/cjQKhQWQLmR/5u7tGCIlXA+nkHxWsmiGgtTotRRb7fV29fahx4kDvnQnzgRzshYj+eT/4ULBLYtDfEYbnSZAljaXdC8DRee6kuUhFR4E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ErGzGUeW; 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="ErGzGUeW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68E7EC4CEEA; Fri, 21 Mar 2025 21:48:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742593716; bh=MKwm/fHil0GDCiiaBpnQB8YlsfUYdX6rYlCKMcY4+DY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ErGzGUeWHbq+jsK4mK0XixzZvRI8yW42+Q7dZbFSRUa6/P11+KQNUAQuYEjf1QoaJ PuQVkND+QgmP0jUk4K+lKzjLZ5eqvHwpJE0Si77vKqr2yaPL844mma6AGcXAV1sL2f G8OGC9AiGQReDTO10zROrYzjlBFfnCZrTVakzCrRX+rbId6c9t55TRqqGkkD9qlOax JQE0SvrPctCwIsVQ8ralYer+ZPBpe0YoQATM/HLx30Rrx5QZv1+bs8iXxP6ttbDDby ieFe2tI1XTNYgnRY4Sqak28E3XR2CwS86UsmVTf8edXStpNXAq2gyidX/TO0ANRitE axiu3jYaMMERQ== 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 v4 1/3] rust: device: implement bus_type_raw() Date: Fri, 21 Mar 2025 22:47:53 +0100 Message-ID: <20250321214826.140946-2-dakr@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250321214826.140946-1-dakr@kernel.org> References: <20250321214826.140946-1-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 Reviewed-by: Benno Lossin Signed-off-by: Danilo Krummrich Reviewed-by: Greg Kroah-Hartman --- rust/kernel/device.rs | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 21b343a1dc4d..67a2fc46cf4c 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -65,6 +65,16 @@ pub(crate) fn as_raw(&self) -> *mut bindings::device { self.0.get() } + /// 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 From patchwork Fri Mar 21 21:47:54 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 14026073 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 BCEC6231CB0; Fri, 21 Mar 2025 21:48:40 +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=1742593720; cv=none; b=sgapiNjqojtQ0dE2wUJJHMAYABk1xjSUMWXhYBoWyrbqjbIfebnEAIg4tJ/Yj7uW0o8se4siuc5mnOpP5l2s8BfgujkWHtBOUPwD1hSlonM8Pximj/djqRWuisThNXfNhIQAtnSvgyQ0O6HqeNWw064YSbo2bcqpH0W8zEwbpNY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742593720; c=relaxed/simple; bh=pUsrb8mKMf/L0eA69D9oO6dXIRS7L12TDvKRAoBAesQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LA+ts+vXLvcSdLpEu8j0dY6O+oBE9URoO+fUfEFoy12LS7LmQY7i9WwYu0dTRBcUZF6xJEc5EC4aykEj3l186ByDyvtc5yhsZk+Ob7HsWXjysV5Dx5DPmenUMRzthUDM5h+9R6uIOu0MOsB839afzGkUfPA4pIMaZENLxnyfYSY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HXGlofsL; 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="HXGlofsL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C591C4CEEC; Fri, 21 Mar 2025 21:48:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742593720; bh=pUsrb8mKMf/L0eA69D9oO6dXIRS7L12TDvKRAoBAesQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HXGlofsLLdfd9Xiv098th5jHZLtENWYrOIII+uW5ypDyUf6xEdfQWajEdwcbaphgI TUV2awcocJzpr4xaOJrvaLBlwCqwY+bZ03ynw0lIpJffNzoJtMz5c68fNYDkWaoVlu QhFG7iPRu3Cf0j/v4VgV4+vODpQvZT7vYpCfld2KVoe4nEcbvIys0zVispWVUtmALF aZBDA/A8yhhveueiJJIilgyG+4rU0Vb8+tU+V+XRyF8ZxYuzYVptP47NbbNYulGiLu 48NPJp0VKJL5NrH+0zMUVkQqKBiaQJziMM1n205Ls1AOJljOs1aLFh3JN+HVANsyZJ Z+zMGjP5ZT6Fg== 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 v4 2/3] rust: pci: impl TryFrom<&Device> for &pci::Device Date: Fri, 21 Mar 2025 22:47:54 +0100 Message-ID: <20250321214826.140946-3-dakr@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250321214826.140946-1-dakr@kernel.org> References: <20250321214826.140946-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement TryFrom<&device::Device> for &Device. This allows us to get a &pci::Device from a generic &Device in a safe way; the conversion fails if the device' bus type does not match with the PCI bus type. Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Signed-off-by: Danilo Krummrich --- rust/kernel/device.rs | 1 - rust/kernel/pci.rs | 25 +++++++++++++++++++++++-- 2 files changed, 23 insertions(+), 3 deletions(-) diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 67a2fc46cf4c..0bbc67edd38d 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -66,7 +66,6 @@ pub(crate) fn as_raw(&self) -> *mut bindings::device { } /// 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`. diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs index 22a32172b108..8b7fcfe8bffc 100644 --- a/rust/kernel/pci.rs +++ b/rust/kernel/pci.rs @@ -6,7 +6,7 @@ use crate::{ alloc::flags::*, - bindings, device, + bindings, container_of, device, device_id::RawDeviceId, devres::Devres, driver, @@ -20,7 +20,7 @@ use core::{ marker::PhantomData, ops::Deref, - ptr::{addr_of_mut, NonNull}, + ptr::{addr_of, addr_of_mut, NonNull}, }; use kernel::prelude::*; @@ -466,6 +466,27 @@ fn as_ref(&self) -> &device::Device { } } +impl TryFrom<&device::Device> for &Device { + type Error = kernel::error::Error; + + fn try_from(dev: &device::Device) -> Result { + #[allow(unused_unsafe)] + // SAFETY: rustc < 1.82 falsely treats this as unsafe, see: + // https://blog.rust-lang.org/2024/10/17/Rust-1.82.0.html#safely-addressing-unsafe-statics + if dev.bus_type_raw() != unsafe { addr_of!(bindings::pci_bus_type) } { + return Err(EINVAL); + } + + // SAFETY: We've just verified that the bus type of `dev` equals `bindings::pci_bus_type`, + // hence `dev` must be embedded in a valid `struct pci_dev` as guaranteed by the + // corresponding C code. + let pdev = unsafe { container_of!(dev.as_raw(), bindings::pci_dev, dev) }; + + // SAFETY: `pdev` is a valid pointer to a `struct pci_dev`. + Ok(unsafe { &*pdev.cast() }) + } +} + // SAFETY: A `Device` is always reference-counted and can be released from any thread. unsafe impl Send for Device {} From patchwork Fri Mar 21 21:47:55 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 14026074 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 EAACD231CB0; Fri, 21 Mar 2025 21:48:43 +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=1742593724; cv=none; b=HfTlzPkU+qZrfIWLbmhZseVOEwGXrrRtIB/t2BXX6MyLkZ4POsv1mi/Qte26BVIbZQIWPAfS+MmrKzYYYxZkuIBwx+WA6dIGB+1PRNHaX3wBeBL3kgaOYN0fDtLBHFuWOTnHdUy5hyECEPc4HEb8VdXEUjd6gfFc3rvjypjBWHg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742593724; c=relaxed/simple; bh=pchn7jrYnae+/6/jOnvBapw0ww9YrRGTJKs+GVP37ow=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CD3ETUH2Evv9z249FYr/A8Sw/EeXQlFKJtbdVoqTGEV6UIufSUICudOaOwjq8+d38jjgKyO4GP0NhTxUMZVAwBdyIokTfcqUEs+PUbrmvl0iGbEV3Ierk+PYgQxhxjOMJpN2XuajgssPsZ0NnEOmOKpsprbJqVoLnwOeyJdENPI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GSXH3xYj; 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="GSXH3xYj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3B49C4CEE3; Fri, 21 Mar 2025 21:48:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742593723; bh=pchn7jrYnae+/6/jOnvBapw0ww9YrRGTJKs+GVP37ow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GSXH3xYj+4omoFM9EBaVijExGJnZuNMPfRmDda3JliX+uQZtz+hxpXeW05o7b3ojz QpWADyCBQcab7TsMr+DEiEaQ5/DSWqEwj8xMzxh/HrpANBxj9DIDLu69KN4HCEzxKL j/JEl/+vzvXHf7xL87kXKY27DIzgQCK/Jfw/QL3pdWGO9FOPiHQdlMoryXBY965LGV QUn3aWydtmEezlI7fDPhOcaMcYfbDZ9auEg9QqL7SBA+h28FVRyrae6dEM3KKRCKVO QEKxlmE0jS1o9FpqMkktan3UwckqH0EkH7NAEAUSS03ndQzOFdOgjezMQ/K29ZaB3i pyCOtFQ5oQPbg== 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 v4 3/3] rust: platform: impl TryFrom<&Device> for &platform::Device Date: Fri, 21 Mar 2025 22:47:55 +0100 Message-ID: <20250321214826.140946-4-dakr@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250321214826.140946-1-dakr@kernel.org> References: <20250321214826.140946-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement 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. Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Signed-off-by: Danilo Krummrich --- rust/kernel/platform.rs | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs index e37531bae8e9..b39ca2573020 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 +234,27 @@ fn as_ref(&self) -> &device::Device { } } +impl TryFrom<&device::Device> for &Device { + type Error = kernel::error::Error; + + fn try_from(dev: &device::Device) -> Result { + #[allow(unused_unsafe)] + // SAFETY: rustc < 1.82 falsely treats this as unsafe, see: + // https://blog.rust-lang.org/2024/10/17/Rust-1.82.0.html#safely-addressing-unsafe-statics + if dev.bus_type_raw() != unsafe { 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` as guaranteed by the corresponding C code. + 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 {}