From patchwork Fri Mar 21 14:57:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 14025638 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 97FCF1D7E26; Fri, 21 Mar 2025 14:59:20 +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=1742569160; cv=none; b=kFuL0wPjX8iZ0RTXcT0NT6WuAOTWZjhtFU8Alxil1M8cOCxtYEb9JPRQVGMXtDyMHsxBgkyQGCbpBPqgxN6LcTYN0zMZmehh/Wk4oigPyV6ff9k+gkwfs8XkUWcRT8j7BdFAAQixNQ2Tp1cWKZUdQLqBgxrBaBImQQJF3c+Z2mM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742569160; c=relaxed/simple; bh=iqf+tTdt2jGaWlTQ8KsyRMl+ITOHzZS2Gb8CPaDPkn0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RzYx+wY/ehSjyJ403xFtnU/379VjVWJAszx9PwYFi3OZHrMu+u/8yk10Kl4UqvO0/AWCXdzZihZ3kx9sxAUvmnHSin4Q8TmK9FIdUH9b01ZpAxqv9A0gzKwg0o6pJKb+AF3a5ymd6AgwDqZoUR45UbPTg+ISCUrFkpo0xfgYJHY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ru6hFph/; 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="Ru6hFph/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9A3AC4CEE9; Fri, 21 Mar 2025 14:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742569160; bh=iqf+tTdt2jGaWlTQ8KsyRMl+ITOHzZS2Gb8CPaDPkn0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ru6hFph/FKAqYte1+tuQpXsDEh3t7xuLslBTTqmN0N0LTAPHsJ+euP2vne/O8Up03 CGKsTOfp1aY1AoHyyVH6sXKWw45c36353613tXgbjXkyo0ky/vogtA6Yvl6IIeDBXd DeAPj/c6u0Mq4SNME84YSTm8acr6F9AzU4mp9uALgq7rMwWKk9X5JzmWgNmjduLcKt 1J69SenBI/8GehEMnjIqom+VMzbU/SKc+bx6q3w78EOqP8M8VmXWSIqpTkvziWP3ll BxD4eP8S+KdvD6oGR6S5oGQ+1bXume9RppnAXx5ss3J237JwyuVg3YWRZP4aPyVQOc MhXEVo9IqXUFQ== 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 v3 2/3] rust: pci: impl TryFrom<&Device> for &pci::Device Date: Fri, 21 Mar 2025 15:57:57 +0100 Message-ID: <20250321145906.3163-3-dakr@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250321145906.3163-1-dakr@kernel.org> References: <20250321145906.3163-1-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 | 22 ++++++++++++++++++++-- 2 files changed, 20 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..c563129d29b6 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 +466,24 @@ 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::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 {}