From patchwork Thu Dec 5 14:14:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13895435 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 281F421A431; Thu, 5 Dec 2024 14:16:49 +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=1733408210; cv=none; b=f9/Gzu3uSv6y6YpvXB3HmeS0YvLK978yj8IWLgeeFyo7/eGxFP3YQJ4wfWCREKZD+oKYgWCgMW2yf1aww5WvnJqLH3qFazFoz84IcCXBJT7/LY6OpLmaIaYbkUTC8tXeTXHRwiHWvlPxIA50kTiXPG1znHaQQtgBobYMEPxMvzE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733408210; c=relaxed/simple; bh=9lJ7gKW/axA9Y9tGKn4BNE3/DgwHFkjbttlWcj6o/JQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=RCz8dZsVsAQl8d4rIoEFHrl2jQFX5rlkBeHQev0a8/XgCbJU3GocexU71BwBWoR1LI+Dg5bBDG+13O+SqF+ZW6KkKiDyz3UPhMkqUxo3G/CwPmm89NgXHR5fBAo0lEse7vHCmiYx+AjzktArwUrwU+qWe2YidG0PpBrC0NnoPX0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y8zP1UI7; 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="Y8zP1UI7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A7BBC4CED1; Thu, 5 Dec 2024 14:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733408209; bh=9lJ7gKW/axA9Y9tGKn4BNE3/DgwHFkjbttlWcj6o/JQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y8zP1UI7LMSD0Zyyyfzp0qgqJ6LG4W1uZwq9vbq4dYzLp3yQilAtTzqYtPfq8j40z 466bev1Y+I2phOQDReZhu/cWEZaO8hqwRN74pfVyradmE5pXR/5l0yb6uzpX/MSZdz Qiwla0waO06FFYSC+lT/w+WImRt6EkVxeFRYLcFjFw+IaarpXxcE5Po9T1RKEIQKuK 16Fg0c4PJcd3hUppnSdWMsiTRyCvgrERTAH0qe/sE+w4ljIz3inQunQJfbmCT+Pqh7 PRQiTaumrFYa0ZytOVaBg1PUUW6h2Qjz1YoHDxf3S8wYMS8j+TirTgtzRsAwtAJTX2 dAETWoqecXj1g== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com, dirk.behme@de.bosch.com, j@jannau.net, fabien.parent@linaro.org, chrisi.schrefl@gmail.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v4 10/13] samples: rust: add Rust PCI sample driver Date: Thu, 5 Dec 2024 15:14:41 +0100 Message-ID: <20241205141533.111830-11-dakr@kernel.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241205141533.111830-1-dakr@kernel.org> References: <20241205141533.111830-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This commit adds a sample Rust PCI driver for QEMU's "pci-testdev" device. To enable this device QEMU has to be called with `-device pci-testdev`. The same driver shows how to use the PCI device / driver abstractions, as well as how to request and map PCI BARs, including a short sequence of MMIO operations. Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + samples/rust/Kconfig | 11 ++++ samples/rust/Makefile | 1 + samples/rust/rust_driver_pci.rs | 109 ++++++++++++++++++++++++++++++++ 4 files changed, 122 insertions(+) create mode 100644 samples/rust/rust_driver_pci.rs diff --git a/MAINTAINERS b/MAINTAINERS index 041b0c1b476f..f97052d5f454 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18100,6 +18100,7 @@ F: include/linux/of_pci.h F: include/linux/pci* F: include/uapi/linux/pci* F: rust/kernel/pci.rs +F: samples/rust/rust_driver_pci.rs PCIE BANDWIDTH CONTROLLER M: Ilpo Järvinen diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig index b0f74a81c8f9..6d468193cdd8 100644 --- a/samples/rust/Kconfig +++ b/samples/rust/Kconfig @@ -30,6 +30,17 @@ config SAMPLE_RUST_PRINT If unsure, say N. +config SAMPLE_RUST_DRIVER_PCI + tristate "PCI Driver" + depends on PCI + help + This option builds the Rust PCI driver sample. + + To compile this as a module, choose M here: + the module will be called driver_pci. + + If unsure, say N. + config SAMPLE_RUST_HOSTPROGS bool "Host programs" help diff --git a/samples/rust/Makefile b/samples/rust/Makefile index c1a5c1655395..2f5b6bdb2fa5 100644 --- a/samples/rust/Makefile +++ b/samples/rust/Makefile @@ -3,6 +3,7 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o +obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI) += rust_driver_pci.o rust_print-y := rust_print_main.o rust_print_events.o diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs new file mode 100644 index 000000000000..76d742189c00 --- /dev/null +++ b/samples/rust/rust_driver_pci.rs @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust PCI driver sample (based on QEMU's `pci-testdev`). +//! +//! To make this driver probe, QEMU must be run with `-device pci-testdev`. + +use kernel::{bindings, c_str, devres::Devres, pci, prelude::*}; + +struct Regs; + +impl Regs { + const TEST: usize = 0x0; + const OFFSET: usize = 0x4; + const DATA: usize = 0x8; + const COUNT: usize = 0xC; + const END: usize = 0x10; +} + +type Bar0 = pci::Bar<{ Regs::END }>; + +#[derive(Debug)] +struct TestIndex(u8); + +impl TestIndex { + const NO_EVENTFD: Self = Self(0); +} + +struct SampleDriver { + pdev: pci::Device, + bar: Devres, +} + +kernel::pci_device_table!( + PCI_TABLE, + MODULE_PCI_TABLE, + ::IdInfo, + [( + pci::DeviceId::new(bindings::PCI_VENDOR_ID_REDHAT, 0x5), + TestIndex::NO_EVENTFD + )] +); + +impl SampleDriver { + fn testdev(index: &TestIndex, bar: &Bar0) -> Result { + // Select the test. + bar.writeb(index.0, Regs::TEST); + + let offset = u32::from_le(bar.readl(Regs::OFFSET)) as usize; + let data = bar.readb(Regs::DATA); + + // Write `data` to `offset` to increase `count` by one. + // + // Note that we need `try_writeb`, since `offset` can't be checked at compile-time. + bar.try_writeb(data, offset)?; + + Ok(bar.readl(Regs::COUNT)) + } +} + +impl pci::Driver for SampleDriver { + type IdInfo = TestIndex; + + const ID_TABLE: pci::IdTable = &PCI_TABLE; + + fn probe( + pdev: &mut pci::Device, + _id: &pci::DeviceId, + info: &Self::IdInfo, + ) -> Result>> { + dev_dbg!(pdev.as_ref(), "Probe Rust PCI driver sample.\n"); + + pdev.enable_device_mem()?; + pdev.set_master(); + + let bar = pdev.iomap_region_sized::<{ Regs::END }>(0, c_str!("rust_driver_pci"))?; + + let drvdata = KBox::new( + Self { + pdev: pdev.clone(), + bar, + }, + GFP_KERNEL, + )?; + + let bar = drvdata.bar.try_access().ok_or(ENXIO)?; + + dev_info!( + pdev.as_ref(), + "pci-testdev data-match count: {}\n", + Self::testdev(info, &bar)? + ); + + Ok(drvdata.into()) + } +} + +impl Drop for SampleDriver { + fn drop(&mut self) { + dev_dbg!(self.pdev.as_ref(), "Remove Rust PCI driver sample.\n"); + } +} + +kernel::module_pci_driver! { + type: SampleDriver, + name: "rust_driver_pci", + author: "Danilo Krummrich", + description: "Rust PCI driver", + license: "GPL v2", +}