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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-10-01 08:39:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-10-01 08:39:23 -0700 |
| commit | eb3289fc474f74105e0627bf508e3f9742fd3b63 (patch) | |
| tree | 4ddfef8ea4474f6677d020c3efc66cc77eb82724 /samples/rust/rust_debugfs.rs | |
| parent | 50c19e20ed2ef359cf155a39c8462b0a6351b9fa (diff) | |
| parent | 6d97171ac6585de698df019b0bfea3f123fd8385 (diff) | |
Merge tag 'driver-core-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
"Auxiliary:
- Drop call to dev_pm_domain_detach() in auxiliary_bus_probe()
- Optimize logic of auxiliary_match_id()
Rust:
- Auxiliary:
- Use primitive C types from prelude
- DebugFs:
- Add debugfs support for simple read/write files and custom
callbacks through a File-type-based and directory-scope-based
API
- Sample driver code for the File-type-based API
- Sample module code for the directory-scope-based API
- I/O:
- Add io::poll module and implement Rust specific
read_poll_timeout() helper
- IRQ:
- Implement support for threaded and non-threaded device IRQs
based on (&Device<Bound>, IRQ number) tuples (IrqRequest)
- Provide &Device<Bound> cookie in IRQ handlers
- PCI:
- Support IRQ requests from IRQ vectors for a specific
pci::Device<Bound>
- Implement accessors for subsystem IDs, revision, devid and
resource start
- Provide dedicated pci::Vendor and pci::Class types for vendor
and class ID numbers
- Implement Display to print actual vendor and class names; Debug
to print the raw ID numbers
- Add pci::DeviceId::from_class_and_vendor() helper
- Use primitive C types from prelude
- Various minor inline and (safety) comment improvements
- Platform:
- Support IRQ requests from IRQ vectors for a specific
platform::Device<Bound>
- Nova:
- Use pci::DeviceId::from_class_and_vendor() to avoid probing
non-display/compute PCI functions
- Misc:
- Add helper for cpu_relax()
- Update ARef import from sync::aref
sysfs:
- Remove bin_attrs_new field from struct attribute_group
- Remove read_new() and write_new() from struct bin_attribute
Misc:
- Document potential race condition in get_dev_from_fwnode()
- Constify node_group argument in software node registration
functions
- Fix order of kernel-doc parameters in various functions
- Set power.no_pm flag for faux devices
- Set power.no_callbacks flag along with the power.no_pm flag
- Constify the pmu_bus bus type
- Minor spelling fixes"
* tag 'driver-core-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (43 commits)
rust: pci: display symbolic PCI vendor names
rust: pci: display symbolic PCI class names
rust: pci: fix incorrect platform reference in PCI driver probe doc comment
rust: pci: fix incorrect platform reference in PCI driver unbind doc comment
perf: make pmu_bus const
samples: rust: Add scoped debugfs sample driver
rust: debugfs: Add support for scoped directories
samples: rust: Add debugfs sample driver
rust: debugfs: Add support for callback-based files
rust: debugfs: Add support for writable files
rust: debugfs: Add support for read-only files
rust: debugfs: Add initial support for directories
driver core: auxiliary bus: Optimize logic of auxiliary_match_id()
driver core: auxiliary bus: Drop dev_pm_domain_detach() call
driver core: Fix order of the kernel-doc parameters
driver core: get_dev_from_fwnode(): document potential race
drivers: base: fix "publically"->"publicly"
driver core/PM: Set power.no_callbacks along with power.no_pm
driver core: faux: Set power.no_pm for faux devices
rust: pci: inline several tiny functions
...
Diffstat (limited to 'samples/rust/rust_debugfs.rs')
| -rw-r--r-- | samples/rust/rust_debugfs.rs | 151 |
1 files changed, 151 insertions, 0 deletions
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(), + } + } + } +} |
