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2025-11-02rust: devres: fix private intra-doc linkMiguel Ojeda
The future move of pin-init to `syn` uncovers the following private intra-doc link: error: public documentation for `Devres` links to private item `Self::inner` --> rust/kernel/devres.rs:106:7 | 106 | /// [`Self::inner`] is guaranteed to be initialized and is always accessed read-only. | ^^^^^^^^^^^ this item is private | = note: this link will resolve properly if you pass `--document-private-items` = note: `-D rustdoc::private-intra-doc-links` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(rustdoc::private_intra_doc_links)]` Currently, when rendered, the link points to "nowhere" (an inexistent anchor for a "method"). Thus fix it. Cc: stable@vger.kernel.org Fixes: f5d3ef25d238 ("rust: devres: get rid of Devres' inner Arc") Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://patch.msgid.link/20251029071406.324511-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-02Merge tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds
Pull drm updates from Dave Airlie: "cross-subsystem: - i2c-hid: Make elan touch controllers power on after panel is enabled - dt bindings for STM32MP25 SoC - pci vgaarb: use screen_info helpers - rust pin-init updates - add MEI driver for late binding firmware update/load uapi: - add ioctl for reassigning GEM handles - provide boot_display attribute on boot-up devices core: - document DRM_MODE_PAGE_FLIP_EVENT - add vendor specific recovery method to drm device wedged uevent gem: - Simplify gpuvm locking ttm: - add interface to populate buffers sched: - Fix race condition in trace code atomic: - Reallow no-op async page flips display: - dp: Fix command length video: - Improve pixel-format handling for struct screen_info rust: - drop Opaque<> from ioctl args - Alloc: - BorrowedPage type and AsPageIter traits - Implement Vmalloc::to_page() and VmallocPageIter - DMA/Scatterlist: - Add dma::DataDirection and type alias for dma_addr_t - Abstraction for struct scatterlist and sg_table - DRM: - simplify use of generics - add DriverFile type alias - drop Object::SIZE - Rust: - pin-init tree merge - Various methods for AsBytes and FromBytes traits gpuvm: - Support madvice in Xe driver gpusvm: - fix hmm_pfn_to_map_order usage in gpusvm bridge: - Improve and fix ref counting on bridge management - cdns-dsi: Various improvements to mode setting - Support Solomon SSD2825 plus DT bindings - Support Waveshare DSI2DPI plus DT bindings - Support Content Protection property - display-connector: Improve DP display detection - Add support for Radxa Ra620 plus DT bindings - adv7511: Provide SPD and HDMI infoframes - it6505: Replace crypto_shash with sha() - synopsys: Add support for DW DPTX Controller plus DT bindings - adv7511: Write full Audio infoframe - ite6263: Support vendor-specific infoframes - simple: Add support for Realtek RTD2171 DP-to-HDMI plus DT bindings panel: - panel-edp: Support mt8189 Chromebooks; Support BOE NV140WUM-N64; Support SHP LQ134Z1; Fixes - panel-simple: Support Olimex LCD-OLinuXino-5CTS plus DT bindings - Support Samsung AMS561RA01 - Support Hydis HV101HD1 plus DT bindings - ilitek-ili9881c: Refactor mode setting; Add support for Bestar BSD1218-A101KL68 LCD plus DT bindings - lvds: Add support for Ampire AMP19201200B5TZQW-T03 to DT bindings - edp: Add support for additonal mt8189 Chromebook panels - lvds: Add DT bindings for EDT ETML0700Z8DHA amdgpu: - add CRIU support for gem objects - RAS updates - VCN SRAM load fixes - EDID read fixes - eDP ALPM support - Documentation updates - Rework PTE flag generation - DCE6 fixes - VCN devcoredump cleanup - MMHUB client id fixes - VCN 5.0.1 RAS support - SMU 13.0.x updates - Expanded PCIe DPC support - Expanded VCN reset support - VPE per queue reset support - give kernel jobs unique id for tracing - pre-populate exported buffers - cyan skillfish updates - make vbios build number available in sysfs - userq updates - HDCP updates - support MMIO remap page as ttm pool - JPEG parser updates - DCE6 DC updates - use devm for i2c buses - GPUVM locking updates - Drop non-DC DCE11 code - improve fallback handling for pixel encoding amdkfd: - SVM/page migration fixes - debugfs fixes - add CRIO support for gem objects - SVM updates radeon: - use dev_warn_once in CS parsers xe: - add madvise interface - add DRM_IOCTL_XE_VM_QUERY_MEMORY_RANGE_ATTRS to query VMA count and memory attributes - drop L# bank mask reporting from media GT3 on Xe3+. - add SLPC power_profile sysfs interface - add configs attribs to add post/mid context-switch commands - handle firmware reported hardware errors notifying userspace with device wedged uevent - use same dir structure across sysfs/debugfs - cleanup and future proof vram region init - add G-states and PCI link states to debugfs - Add SRIOV support for CCS surfaces on Xe2+ - Enable SRIOV PF mode by default on supported platforms - move flush to common code - extended core workarounds for Xe2/3 - use DRM scheduler for delayed GT TLB invalidations - configs improvements and allow VF device enablement - prep work to expose mmio regions to userspace - VF migration support added - prepare GPU SVM for THP migration - start fixing XE_PAGE_SIZE vs PAGE_SIZE - add PSMI support for hw validation - resize VF bars to max possible size according to number of VFs - Ensure GT is in C0 during resume - pre-populate exported buffers - replace xe_hmm with gpusvm - add more SVM GT stats to debugfs - improve fake pci and WA kunnit handle for new platform testing - Test GuC to GuC comms to add debugging - use attribute groups to simplify sysfs registration - add Late Binding firmware code to interact with MEI i915: - apply multiple JSL/EHL/Gen7/Gen6 workarounds properly - protect against overflow in active_engine() - Use try_cmpxchg64() in __active_lookup() - include GuC registers in error state - get rid of dev->struct_mutex - iopoll: generalize read_poll_timout - lots more display refactoring - Reject HBR3 in any eDP Panel - Prune modes for YUV420 - Display Wa fix, additions, and updates - DP: Fix 2.7 Gbps link training on g4x - DP: Adjust the idle pattern handling - DP: Shuffle the link training code a bit - Don't set/read the DSI C clock divider on GLK - Enable_psr kernel parameter changes - Type-C enabled/disconnected dp-alt sink - Wildcat Lake enabling - DP HDR updates - DRAM detection - wait PSR idle on dsb commit - Remove FBC modulo 4 restriction for ADL-P+ - panic: refactor framebuffer allocation habanalabs: - debug/visibility improvements - vmalloc-backed coherent mmap support - HLDIO infrastructure nova-core: - various register!() macro improvements - minor vbios/firmware fixes/refactoring - advance firmware boot stages; process Booter and patch signatures - process GSP and GSP bootloader - Add r570.144 firmware bindings and update to it - Move GSP boot code to own module - Use new pin-init features to store driver's private data in a single allocation - Update ARef import from sync::aref nova-drm: - Update ARef import from sync::aref tyr: - initial driver skeleton for a rust driver for ARM Mali GPUs - capable of powering up, query metadata and provide it to userspace. msm: - GPU and Core: - in DT bindings describe clocks per GPU type - GMU bandwidth voting for x1-85 - a623/a663 speedbins - cleanup some remaining no-iommu leftovers after VM_BIND conversion - fix GEM obj 32b size truncation - add missing VM_BIND param validation - IFPC for x1-85 and a750 - register xml and gen_header.py sync from mesa - Display: - add missing bindings for display on SC8180X - added DisplayPort MST bindings - conversion from round_rate() to determine_rate() amdxdna: - add IOCTL_AMDXDNA_GET_ARRAY - support user space allocated buffers - streamline PM interfaces - Refactoring wrt. hardware contexts - improve error reporting nouveau: - use GSP firmware by default - improve error reporting - Pre-populate exported buffers ast: - Clean up detection of DRAM config exynos: - add DSIM bridge driver support for Exynos7870 - Document Exynos7870 DSIM compatible in dt-binding panthor: - Print task/pid on errors - Add support for Mali G710, G510, G310, Gx15, Gx20, Gx25 - Improve cache flushing - Fail VM bind if BO has offset renesas: - convert to RUNTIME_PM_OPS rcar-du: - Make number of lanes configurable - Use RUNTIME_PM_OPS - Add support for DSI commands rocket: - Add driver for Rockchip NPU plus DT bindings - Use kfree() and sizeof() correctly - Test DMA status rockchip: - dsi2: Add support for RK3576 plus DT bindings - Add support for RK3588 DPTX output tidss: - Use crtc_ fields for programming display mode - Remove other drivers from aperture pixpaper: - Add support for Mayqueen Pixpaper plus DT bindings v3d: - Support querying nubmer of GPU resets for KHR_robustness stm: - Clean up logging - ltdc: Add support support for STM32MP257F-EV1 plus DT bindings sitronix: - st7571-i2c: Add support for inverted displays and 2-bit grayscale tidss: - Convert to kernel's FIELD_ macros vesadrm: - Support 8-bit palette mode imagination: - Improve power management - Add support for TH1520 GPU - Support Risc-V architectures v3d: - Improve job management and locking vkms: - Support variants of ARGB8888, ARGB16161616, RGB565, RGB888 and P01x - Spport YUV with 16-bit components" * tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel: (1455 commits) drm/amd: Add name to modes from amdgpu_connector_add_common_modes() drm/amd: Drop some common modes from amdgpu_connector_add_common_modes() drm/amdgpu: update MODULE_PARM_DESC for freesync_video drm/amd: Use dynamic array size declaration for amdgpu_connector_add_common_modes() drm/amd/display: Share dce100_validate_global with DCE6-8 drm/amd/display: Share dce100_validate_bandwidth with DCE6-8 drm/amdgpu: Fix fence signaling race condition in userqueue amd/amdkfd: enhance kfd process check in switch partition amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw drm/amd/display: Reject modes with too high pixel clock on DCE6-10 drm/amd: Drop unnecessary check in amdgpu_connector_add_common_modes() drm/amd/display: Only enable common modes for eDP and LVDS drm/amdgpu: remove the redeclaration of variable i drm/amdgpu/userq: assign an error code for invalid userq va drm/amdgpu: revert "rework reserved VMID handling" v2 drm/amdgpu: remove leftover from enforcing isolation by VMID drm/amdgpu: Add fallback to pipe reset if KCQ ring reset fails accel/habanalabs: add Infineon version check accel/habanalabs/gaudi2: read preboot status after recovering from dirty state accel/habanalabs: add HL_GET_P_STATE passthrough type ...
2025-09-17Merge tag 'drm-rust-next-2025-09-16' of ↵Dave Airlie
https://gitlab.freedesktop.org/drm/rust/kernel into drm-next DRM Rust changes for v6.18 Alloc - Add BorrowedPage type and AsPageIter trait - Implement Vmalloc::to_page() and VmallocPageIter - Implement AsPageIter for VBox and VVec DMA & Scatterlist - Add dma::DataDirection and type alias for dma_addr_t - Abstraction for struct scatterlist and struct sg_table DRM - In the DRM GEM module, simplify overall use of generics, add DriverFile type alias and drop Object::SIZE. Nova (Core) - Various register!() macro improvements (paving the way for lifting it to common driver infrastructure) - Minor VBios fixes and refactoring - Minor firmware request refactoring - Advance firmware boot stages; process Booter and patch its signature, process GSP and GSP bootloader - Switch development fimrware version to r570.144 - Add basic firmware bindings for r570.144 - Move GSP boot code to its own module - Clean up and take advantage of pin-init features to store most of the driver's private data within a single allocation - Update ARef import from sync::aref - Add website to MAINTAINERS entry Nova (DRM) - Update ARef import from sync::aref - Add website to MAINTAINERS entry Pin-Init - Merge pin-init PR from Benno - `#[pin_data]` now generates a `*Projection` struct similar to the `pin-project` crate. - Add initializer code blocks to `[try_][pin_]init!` macros: make initializer macros accept any number of `_: {/* arbitrary code */},` & make them run the code at that point. - Make the `[try_][pin_]init!` macros expose initialized fields via a `let` binding as `&mut T` or `Pin<&mut T>` for later fields. Rust - Various methods for AsBytes and FromBytes traits Tyr - Initial Rust driver skeleton for ARM Mali GPUs. - It can power up the GPU, query for GPU metatdata through MMIO and provide the metadata to userspace via DRM device IOCTL (struct drm_panthor_dev_query). Signed-off-by: Dave Airlie <airlied@redhat.com> From: "Danilo Krummrich" <dakr@kernel.org> Link: https://lore.kernel.org/r/DCUC4SY6SRBD.1ZLHAIQZOC6KG@kernel.org
2025-09-11rust: pin-init: add references to previously initialized fieldsBenno Lossin
After initializing a field in an initializer macro, create a variable holding a reference that points at that field. The type is either `Pin<&mut T>` or `&mut T` depending on the field's structural pinning kind. [ Applied fixes to devres and rust_driver_pci sample - Benno] Reviewed-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Benno Lossin <lossin@kernel.org>
2025-08-25Merge 6.17-rc3 into driver-core-nextGreg Kroah-Hartman
We need the driver core and rust fixes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15rust: driver-core: Update ARef and AlwaysRefCounted imports from sync::arefShankari Anand
Update call sites in the driver-core files and its related samples to import `ARef` and `AlwaysRefCounted` from `sync::aref` instead of `types`. This aligns with the ongoing effort to move `ARef` and `AlwaysRefCounted` to sync. Suggested-by: Benno Lossin <lossin@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1173 Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com> Link: https://lore.kernel.org/r/20250814104615.355106-1-shankari.ak0208@gmail.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-08-14rust: devres: fix leaking call to devm_add_action()Danilo Krummrich
When the data argument of Devres::new() is Err(), we leak the preceding call to devm_add_action(). In order to fix this, call devm_add_action() in a unit type initializer in try_pin_init!() after the initializers of all other fields. Fixes: f5d3ef25d238 ("rust: devres: get rid of Devres' inner Arc") Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250812130928.11075-1-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-08-03Merge tag 'rust-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness', 'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and 'ref_as_ptr' These are intended to avoid type casts with the 'as' operator, which are quite powerful, into restricted variants that are less powerful and thus should help to avoid mistakes - Remove the 'author' key now that most instances were moved to the plural one in the previous cycle 'kernel' crate: - New 'bug' module: add 'warn_on!' macro which reuses the existing 'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and kernel parameters: warn_on!(value == 42); To avoid duplicating the assembly code, the same strategy is followed as for the static branch code in order to share the assembly between both C and Rust This required a few rearrangements on C arch headers -- the existing C macros should still generate the same outputs, thus no functional change expected there - 'workqueue' module: add delayed work items, including a 'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an 'enqueue_delayed' method, e.g.: /// Enqueue the struct for execution on the system workqueue, /// where its value will be printed 42 jiffies later. fn print_later(value: Arc<MyStruct>) { let _ = workqueue::system().enqueue_delayed(value, 42); } - New 'bits' module: add support for 'bit' and 'genmask' functions, with runtime- and compile-time variants, e.g.: static_assert!(0b00010000 == bit_u8(4)); static_assert!(0b00011110 == genmask_u8(1..=4)); assert!(checked_bit_u32(u32::BITS).is_none()); - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which reads NUL-terminated strings from userspace into a '&CStr' Introduce 'UserPtr' newtype, similar in purpose to '__user' in C, to minimize mistakes handling userspace pointers, including mixing them up with integers and leaking them via the 'Debug' trait. Add it to the prelude, too - Start preparations for the replacement of our custom 'CStr' type with the analogous type in the 'core' standard library. This will take place across several cycles to make it easier. For this one, it includes a new 'fmt' module, using upstream method names and some other cleanups Replace 'fmt!' with a re-export, which helps Clippy lint properly, and clean up the found 'uninlined-format-args' instances - 'dma' module: - Clarify wording and be consistent in 'coherent' nomenclature - Convert the 'read!()' and 'write!()' macros to return a 'Result' - Add 'as_slice()', 'write()' methods in 'CoherentAllocation' - Expose 'count()' and 'size()' in 'CoherentAllocation' and add the corresponding type invariants - Implement 'CoherentAllocation::dma_handle_with_offset()' - 'time' module: - Make 'Instant' generic over clock source. This allows the compiler to assert that arithmetic expressions involving the 'Instant' use 'Instants' based on the same clock source - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers take a 'Duration' or an 'Instant' when setting the expiry time, depending on the timer mode. With this change, the compiler can check the type matches the timer mode - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep function that will select an appropriate sleep method depending on the requested sleep time - Avoid 64-bit divisions on 32-bit hardware when calculating timestamps - Seal the 'HrTimerMode' trait. This prevents users of the 'HrTimerMode' from implementing the trait on their own types - Pass the correct timer mode ID to 'hrtimer_start_range_ns()' - 'list' module: remove 'OFFSET' constants, allowing to remove pointer arithmetic; now 'impl_list_item!' invokes 'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other simplifications too - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a constant, which avoids exposing the type of the opaque pointer, and require 'into_foreign' to return non-null Remove the 'Either<L, R>' type as well. It is unused, and we want to encourage the use of custom enums for concrete use cases - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types to allow them to be used in generic APIs - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>'; and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>' - 'Opaque' type: add 'cast_from' method to perform a restricted cast that cannot change the inner type and use it in callers of 'container_of!'. Rename 'raw_get' to 'cast_into' to match it - 'rbtree' module: add 'is_empty' method - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and 'ARef', which are moved from the too general 'types' module which we want to reduce or eventually remove. Also fix a safety comment in 'static_lock_class' 'pin-init' crate: - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are now (pin-)initializers - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()' - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide it via 'Zeroable::zeroed()' - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for 'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for '"Rust"' and '"C"' ABIs and up to 20 arguments - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E> [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T' - Renamed 'zeroed()' to 'init_zeroed()' - Upstream dev news: improve CI more to deny warnings, use '--all-targets'. Check the synchronization status of the two '-next' branches in upstream and the kernel MAINTAINERS: - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo Stoakes as reviewers (thanks everyone) And a few other cleanups and improvements" * tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits) rust: Add warn_on macro arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust rust: kernel: move ARef and AlwaysRefCounted to sync::aref rust: sync: fix safety comment for `static_lock_class` rust: types: remove `Either<L, R>` rust: kernel: use `core::ffi::CStr` method names rust: str: add `CStr` methods matching `core::ffi::CStr` rust: str: remove unnecessary qualification rust: use `kernel::{fmt,prelude::fmt!}` rust: kernel: add `fmt` module rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args scripts: rust: emit path candidates in panic message scripts: rust: replace length checks with match rust: list: remove nonexistent generic parameter in link rust: bits: add support for bits/genmask macros rust: list: remove OFFSET constants rust: list: add `impl_list_item!` examples rust: list: use fully qualified path ...
2025-07-15rust: devres: provide an accessor for the deviceDanilo Krummrich
Provide an accessor for the Device a Devres instance has been created with. For instance, this is useful when registrations want to provide a &Device<Bound> for a scope that is protected by Devres. Suggested-by: Benno Lossin <lossin@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250713182737.64448-1-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-07-15rust: devres: initialize Devres::inner::data lastDanilo Krummrich
Users may want to access the Devres object from callbacks registered through the initialization of Devres::inner::data. For those accesses to be valid, Devres::inner::data must be initialized last [1]. Credit to Boqun for spotting this [2]. Link: https://lore.kernel.org/lkml/DBBPHO26CPBS.2OVI1OERCB2J5@kernel.org/ [1] Link: https://lore.kernel.org/lkml/aHSmxWeIy3L-AKIV@Mac.home/ [2] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250714113712.22158-1-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-07-05rust: devres: remove unused importTamir Duberstein
As far as I can tell, `c_str` was never used, hence remove it. Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://lore.kernel.org/r/20250704-cstr-include-devres-v1-1-4ee9e56fca09@gmail.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-28rust: devres: get rid of Devres' inner ArcDanilo Krummrich
So far Devres uses an inner memory allocation and reference count, i.e. an inner Arc, in order to ensure that the devres callback can't run into a use-after-free in case where the Devres object is dropped while the devres callback runs concurrently. Instead, use a completion in order to avoid a potential UAF: In Devres::drop(), if we detect that we can't remove the devres action anymore, we wait for the completion that is completed from the devres callback. If, in turn, we were able to successfully remove the devres action, we can just go ahead. This, again, allows us to get rid of the internal Arc, and instead let Devres consume an `impl PinInit<T, E>` in order to return an `impl PinInit<Devres<T>, E>`, which enables us to get away with less memory allocations. Additionally, having the resulting explicit synchronization in Devres::drop() prevents potential subtle undesired side effects of the devres callback dropping the final Arc reference asynchronously within the devres callback. Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20250626200054.243480-4-dakr@kernel.org [ Move '# Invariants' below '# Examples'. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-28rust: devres: replace Devres::new_foreign_owned()Danilo Krummrich
Replace Devres::new_foreign_owned() with devres::register(). The current implementation of Devres::new_foreign_owned() creates a full Devres container instance, including the internal Revocable and completion. However, none of that is necessary for the intended use of giving full ownership of an object to devres and getting it dropped once the given device is unbound. Hence, implement devres::register(), which is limited to consume the given data, wrap it in a KBox and drop the KBox once the given device is unbound, without any other synchronization. Cc: Dave Airlie <airlied@redhat.com> Cc: Simona Vetter <simona.vetter@ffwll.ch> Cc: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250626200054.243480-3-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-28rust: revocable: support fallible PinInit typesDanilo Krummrich
Currently, Revocable::new() only supports infallible PinInit implementations, i.e. impl PinInit<T, Infallible>. This has been sufficient so far, since users such as Devres do not support fallibility. Since this is about to change, make Revocable::new() generic over the error type E. Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20250626200054.243480-2-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-28rust: devres: require T: Send for DevresDanilo Krummrich
Due to calling Revocable::revoke() from Devres::devres_callback() T may be dropped from Devres::devres_callback() and hence must be Send. Fix this by adding the corresponding bound to Devres and DevresInner. Reported-by: Boqun Feng <boqun.feng@gmail.com> Closes: https://lore.kernel.org/lkml/aFzI5L__OcB9hqdG@Mac.home/ Fixes: 76c01ded724b ("rust: add devres abstraction") Reviewed-by: Boqun Feng <boqun.fenng@gmail.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250626132544.72866-1-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-24rust: Use consistent "# Examples" heading style in rustdocViresh Kumar
Use a consistent `# Examples` heading in rustdoc across the codebase. Some modules previously used `## Examples` (even when they should be available as top-level headers), while others used `# Example`, which deviates from the preferred `# Examples` style. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/ddd5ce0ac20c99a72a4f1e4322d3de3911056922.1749545815.git.viresh.kumar@linaro.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-22rust: enable `clippy::as_underscore` lintTamir Duberstein
In Rust 1.63.0, Clippy introduced the `as_underscore` lint [1]: > The conversion might include lossy conversion or a dangerous cast that > might go undetected due to the type being inferred. > > The lint is allowed by default as using `_` is less wordy than always > specifying the type. Always specifying the type is especially helpful in function call contexts where the inferred type may change at a distance. Specifying the type also allows Clippy to spot more cases of `useless_conversion`. The primary downside is the need to specify the type in trivial getters. There are 4 such functions: 3 have become slightly less ergonomic, 1 was revealed to be a `useless_conversion`. While this doesn't eliminate unchecked `as` conversions, it makes such conversions easier to scrutinize. It also has the slight benefit of removing a degree of freedom on which to bikeshed. Thus apply the changes and enable the lint -- no functional change intended. Link: https://rust-lang.github.io/rust-clippy/master/index.html#as_underscore [1] Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-4-f43b024581e8@gmail.com [ Changed `isize` to `c_long`. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-22rust: enable `clippy::as_ptr_cast_mut` lintTamir Duberstein
In Rust 1.66.0, Clippy introduced the `as_ptr_cast_mut` lint [1]: > Since `as_ptr` takes a `&self`, the pointer won’t have write > permissions unless interior mutability is used, making it unlikely > that having it as a mutable pointer is correct. There is only one affected callsite, and the change amounts to replacing `as _` with `.cast_mut().cast()`. This doesn't change the semantics, but is more descriptive of what's going on. Apply this change and enable the lint -- no functional change intended. Link: https://rust-lang.github.io/rust-clippy/master/index.html#as_ptr_cast_mut [1] Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-3-f43b024581e8@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-22rust: enable `clippy::ptr_as_ptr` lintTamir Duberstein
In Rust 1.51.0, Clippy introduced the `ptr_as_ptr` lint [1]: > Though `as` casts between raw pointers are not terrible, > `pointer::cast` is safer because it cannot accidentally change the > pointer's mutability, nor cast the pointer to other types like `usize`. There are a few classes of changes required: - Modules generated by bindgen are marked `#[allow(clippy::ptr_as_ptr)]`. - Inferred casts (` as _`) are replaced with `.cast()`. - Ascribed casts (` as *... T`) are replaced with `.cast::<T>()`. - Multistep casts from references (` as *const _ as *const T`) are replaced with `core::ptr::from_ref(&x).cast()` with or without `::<T>` according to the previous rules. The `core::ptr::from_ref` call is required because `(x as *const _).cast::<T>()` results in inference failure. - Native literal C strings are replaced with `c_str!().as_char_ptr()`. - `*mut *mut T as _` is replaced with `let *mut *const T = (*mut *mut T)`.cast();` since pointer to pointer can be confusing. Apply these changes and enable the lint -- no functional change intended. Link: https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr [1] Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-1-f43b024581e8@gmail.com [ Added `.cast()` for `opp`. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-13rust: devres: do not dereference to the internal RevocableDanilo Krummrich
We can't expose direct access to the internal Revocable, since this allows users to directly revoke the internal Revocable without Devres having the chance to synchronize with the devres callback -- we have to guarantee that the internal Revocable has been fully revoked before the device is fully unbound. Hence, remove the corresponding Deref implementation and, instead, provide indirect accessors for the internal Revocable. Note that we can still support Devres::revoke() by implementing the required synchronization (which would be almost identical to the synchronization in Devres::drop()). Fixes: 76c01ded724b ("rust: add devres abstraction") Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250611174827.380555-1-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-13rust: devres: fix race in Devres::drop()Danilo Krummrich
In Devres::drop() we first remove the devres action and then drop the wrapped device resource. The design goal is to give the owner of a Devres object control over when the device resource is dropped, but limit the overall scope to the corresponding device being bound to a driver. However, there's a race that was introduced with commit 8ff656643d30 ("rust: devres: remove action in `Devres::drop`"), but also has been (partially) present from the initial version on. In Devres::drop(), the devres action is removed successfully and subsequently the destructor of the wrapped device resource runs. However, there is no guarantee that the destructor of the wrapped device resource completes before the driver core is done unbinding the corresponding device. If in Devres::drop(), the devres action can't be removed, it means that the devres callback has been executed already, or is still running concurrently. In case of the latter, either Devres::drop() wins revoking the Revocable or the devres callback wins revoking the Revocable. If Devres::drop() wins, we (again) have no guarantee that the destructor of the wrapped device resource completes before the driver core is done unbinding the corresponding device. CPU0 CPU1 ------------------------------------------------------------------------ Devres::drop() { Devres::devres_callback() { self.data.revoke() { this.data.revoke() { is_available.swap() == true is_available.swap == false } } // [...] // device fully unbound drop_in_place() { // release device resource } } } Depending on the specific device resource, this can potentially lead to user-after-free bugs. In order to fix this, implement the following logic. In the devres callback, we're always good when we get to revoke the device resource ourselves, i.e. Revocable::revoke() returns true. If Revocable::revoke() returns false, it means that Devres::drop(), concurrently, already drops the device resource and we have to wait for Devres::drop() to signal that it finished dropping the device resource. Note that if we hit the case where we need to wait for the completion of Devres::drop() in the devres callback, it means that we're actually racing with a concurrent Devres::drop() call, which already started revoking the device resource for us. This is rather unlikely and means that the concurrent Devres::drop() already started doing our work and we just need to wait for it to complete it for us. Hence, there should not be any additional overhead from that. (Actually, for now it's even better if Devres::drop() does the work for us, since it can bypass the synchronize_rcu() call implied by Revocable::revoke(), but this goes away anyways once I get to implement the split devres callback approach, which allows us to first flip the atomics of all registered Devres objects of a certain device, execute a single synchronize_rcu() and then drop all revocable objects.) In Devres::drop() we try to revoke the device resource. If that is *not* successful, it means that the devres callback already did and we're good. Otherwise, we try to remove the devres action, which, if successful, means that we're good, since the device resource has just been revoked by us *before* we removed the devres action successfully. If the devres action could not be removed, it means that the devres callback must be running concurrently, hence we signal that the device resource has been revoked by us, using the completion. This makes it safe to drop a Devres object from any task and at any point of time, which is one of the design goals. Fixes: 76c01ded724b ("rust: add devres abstraction") Reported-by: Alice Ryhl <aliceryhl@google.com> Closes: https://lore.kernel.org/lkml/aD64YNuqbPPZHAa5@google.com/ Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250612121817.1621-4-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-12rust: devres: fix doctest build under `!CONFIG_PCI`Miguel Ojeda
The doctest requires `CONFIG_PCI`: error[E0432]: unresolved import `kernel::pci` --> rust/doctests_kernel_generated.rs:2689:44 | 2689 | use kernel::{device::Core, devres::Devres, pci}; | ^^^ no `pci` in the root | note: found an item that was configured out --> rust/kernel/lib.rs:96:9 note: the item is gated here --> rust/kernel/lib.rs:95:1 Thus conditionally compile it (which still checks the syntax). Fixes: f301cb978c06 ("rust: devres: implement Devres::access()") Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20250511182533.1016163-1-ojeda@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-04rust: devres: implement Devres::access()Danilo Krummrich
Implement a direct accessor for the data stored within the Devres for cases where we can prove that we own a reference to a Device<Bound> (i.e. a bound device) of the same device that was used to create the corresponding Devres container. Usually, when accessing the data stored within a Devres container, it is not clear whether the data has been revoked already due to the device being unbound and, hence, we have to try whether the access is possible and subsequently keep holding the RCU read lock for the duration of the access. However, when we can prove that we hold a reference to Device<Bound> matching the device the Devres container has been created with, we can guarantee that the device is not unbound for the duration of the lifetime of the Device<Bound> reference and, hence, it is not possible for the data within the Devres container to be revoked. Therefore, in this case, we can bypass the atomic check and the RCU read lock, which is a great optimization and simplification for drivers. Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Link: https://lore.kernel.org/r/20250428140137.468709-3-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-04-17rust: devres: require a bound deviceDanilo Krummrich
Require the Bound device context to be able to a new Devres container. This ensures that we can't register devres callbacks for unbound devices. Link: https://lore.kernel.org/r/20250413173758.12068-9-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-02-25rust: io: fix devres test with new io accessor functionsFiona Behrens
Fix doctest of `Devres` which still used `writeb` instead of `write8`. Fixes: 354fd6e86fac ("rust: io: rename `io::Io` accessors") Signed-off-by: Fiona Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/20250224-rust-iowrite-read8-fix-v1-1-c6abee346897@kloenk.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10rust: devres: remove action in `Devres::drop`Danilo Krummrich
So far `DevresInner` is kept alive, even if `Devres` is dropped until the devres callback is executed to avoid a WARN() when the action has been released already. With the introduction of devm_remove_action_nowarn() we can remove the action in `Devres::drop`, handle the case where the action has been released already and hence also free `DevresInner`. Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250107122609.8135-2-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: add devres abstractionDanilo Krummrich
Add a Rust abstraction for the kernel's devres (device resource management) implementation. The Devres type acts as a container to manage the lifetime and accessibility of device bound resources. Therefore it registers a devres callback and revokes access to the resource on invocation. Users of the Devres abstraction can simply free the corresponding resources in their Drop implementation, which is invoked when either the Devres instance goes out of scope or the devres callback leads to the resource being revoked, which implies a call to drop_in_place(). Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-9-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>