diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | samples/rust/Kconfig | 11 | ||||
| -rw-r--r-- | samples/rust/Makefile | 1 | ||||
| -rw-r--r-- | samples/rust/rust_debugfs.rs | 151 |
4 files changed, 164 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 4dc5d124bb14..4c471251a304 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7496,6 +7496,7 @@ F: rust/kernel/devres.rs F: rust/kernel/driver.rs F: rust/kernel/faux.rs F: rust/kernel/platform.rs +F: samples/rust/rust_debugfs.rs F: samples/rust/rust_driver_platform.rs F: samples/rust/rust_driver_faux.rs diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig index 7f7371a004ee..01101db41ae3 100644 --- a/samples/rust/Kconfig +++ b/samples/rust/Kconfig @@ -62,6 +62,17 @@ config SAMPLE_RUST_DMA If unsure, say N. +config SAMPLE_RUST_DEBUGFS + tristate "DebugFS Test Module" + depends on DEBUG_FS + help + This option builds the Rust DebugFS Test module sample. + + To compile this as a module, choose M here: + the module will be called rust_debugfs. + + If unsure, say N. + config SAMPLE_RUST_DRIVER_PCI tristate "PCI Driver" depends on PCI diff --git a/samples/rust/Makefile b/samples/rust/Makefile index bd2faad63b4f..61276222a99f 100644 --- a/samples/rust/Makefile +++ b/samples/rust/Makefile @@ -4,6 +4,7 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o obj-$(CONFIG_SAMPLE_RUST_MISC_DEVICE) += rust_misc_device.o obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o +obj-$(CONFIG_SAMPLE_RUST_DEBUGFS) += rust_debugfs.o obj-$(CONFIG_SAMPLE_RUST_DMA) += rust_dma.o obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI) += rust_driver_pci.o obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM) += rust_driver_platform.o diff --git a/samples/rust/rust_debugfs.rs b/samples/rust/rust_debugfs.rs new file mode 100644 index 000000000000..82b61a15a34b --- /dev/null +++ b/samples/rust/rust_debugfs.rs @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2025 Google LLC. + +//! Sample DebugFS exporting platform driver +//! +//! To successfully probe this driver with ACPI, use an ssdt that looks like +//! +//! ```dsl +//! DefinitionBlock ("", "SSDT", 2, "TEST", "VIRTACPI", 0x00000001) +//! { +//! Scope (\_SB) +//! { +//! Device (T432) +//! { +//! Name (_HID, "LNUXBEEF") // ACPI hardware ID to match +//! Name (_UID, 1) +//! Name (_STA, 0x0F) // Device present, enabled +//! Name (_DSD, Package () { // Sample attribute +//! ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), +//! Package() { +//! Package(2) {"compatible", "sample-debugfs"} +//! } +//! }) +//! Name (_CRS, ResourceTemplate () +//! { +//! Memory32Fixed (ReadWrite, 0xFED00000, 0x1000) +//! }) +//! } +//! } +//! } +//! ``` + +use core::str::FromStr; +use core::sync::atomic::AtomicUsize; +use core::sync::atomic::Ordering; +use kernel::c_str; +use kernel::debugfs::{Dir, File}; +use kernel::new_mutex; +use kernel::prelude::*; +use kernel::sync::Mutex; + +use kernel::{acpi, device::Core, of, platform, str::CString, types::ARef}; + +kernel::module_platform_driver! { + type: RustDebugFs, + name: "rust_debugfs", + authors: ["Matthew Maurer"], + description: "Rust DebugFS usage sample", + license: "GPL", +} + +#[pin_data] +struct RustDebugFs { + pdev: ARef<platform::Device>, + // As we only hold these for drop effect (to remove the directory/files) we have a leading + // underscore to indicate to the compiler that we don't expect to use this field directly. + _debugfs: Dir, + #[pin] + _compatible: File<CString>, + #[pin] + counter: File<AtomicUsize>, + #[pin] + inner: File<Mutex<Inner>>, +} + +#[derive(Debug)] +struct Inner { + x: u32, + y: u32, +} + +impl FromStr for Inner { + type Err = Error; + fn from_str(s: &str) -> Result<Self> { + let mut parts = s.split_whitespace(); + let x = parts + .next() + .ok_or(EINVAL)? + .parse::<u32>() + .map_err(|_| EINVAL)?; + let y = parts + .next() + .ok_or(EINVAL)? + .parse::<u32>() + .map_err(|_| EINVAL)?; + if parts.next().is_some() { + return Err(EINVAL); + } + Ok(Inner { x, y }) + } +} + +kernel::acpi_device_table!( + ACPI_TABLE, + MODULE_ACPI_TABLE, + <RustDebugFs as platform::Driver>::IdInfo, + [(acpi::DeviceId::new(c_str!("LNUXBEEF")), ())] +); + +impl platform::Driver for RustDebugFs { + type IdInfo = (); + const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None; + const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE); + + fn probe( + pdev: &platform::Device<Core>, + _info: Option<&Self::IdInfo>, + ) -> Result<Pin<KBox<Self>>> { + let result = KBox::try_pin_init(RustDebugFs::new(pdev), GFP_KERNEL)?; + // We can still mutate fields through the files which are atomic or mutexed: + result.counter.store(91, Ordering::Relaxed); + { + let mut guard = result.inner.lock(); + guard.x = guard.y; + guard.y = 42; + } + Ok(result) + } +} + +impl RustDebugFs { + fn build_counter(dir: &Dir) -> impl PinInit<File<AtomicUsize>> + '_ { + dir.read_write_file(c_str!("counter"), AtomicUsize::new(0)) + } + + fn build_inner(dir: &Dir) -> impl PinInit<File<Mutex<Inner>>> + '_ { + dir.read_write_file(c_str!("pair"), new_mutex!(Inner { x: 3, y: 10 })) + } + + fn new(pdev: &platform::Device<Core>) -> impl PinInit<Self, Error> + '_ { + let debugfs = Dir::new(c_str!("sample_debugfs")); + let dev = pdev.as_ref(); + + try_pin_init! { + Self { + _compatible <- debugfs.read_only_file( + c_str!("compatible"), + dev.fwnode() + .ok_or(ENOENT)? + .property_read::<CString>(c_str!("compatible")) + .required_by(dev)?, + ), + counter <- Self::build_counter(&debugfs), + inner <- Self::build_inner(&debugfs), + _debugfs: debugfs, + pdev: pdev.into(), + } + } + } +} |