Commit Graph

55 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
1da0ca4bdf Merge patch series "Rust support for struct iov_iter"
Alice Ryhl <aliceryhl@google.com> says:

This series adds support for the `struct iov_iter` type. This type
represents an IO buffer for reading or writing, and can be configured
for either direction of communication.

In Rust, we define separate types for reading and writing. This will
ensure that you cannot mix them up and e.g. call copy_from_iter in a
read_iter syscall.

To use the new abstractions, miscdevices are given new methods read_iter
and write_iter that can be used to implement the read/write syscalls on
a miscdevice. The miscdevice sample is updated to provide read/write
operations.

Intended for Greg's miscdevice tree.

Link: https://lore.kernel.org/r/20250822-iov-iter-v5-0-6ce4819c2977@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-06 13:27:23 +02:00
Lee Jones
e5b0d7da94 samples: rust_misc_device: Expand the sample to support read()ing from userspace
A userland application can now operate on the char device with read() in
order to consume a locally held buffer.  Memory for the buffer is to be
provisioned and the buffer populated in its subsequently provided
write() counterpart.

Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250822-iov-iter-v5-5-6ce4819c2977@google.com
2025-09-06 13:27:20 +02:00
Shankari Anand
9e57dbcbde rust: miscdevice: update ARef import to sync::aref
Update the import of `ARef` in misc_device sample to use
`sync::aref` instead of `types`.

This is part of the ongoing effort to move `ARef` and
`AlwaysRefCounted` to the `sync` module for better modularity
and type organization.

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>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250818132806.134248-1-shankari.ak0208@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19 12:37:21 +02:00
Linus Torvalds
352af6a011 Merge tag 'rust-6.17' of 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
  ...
2025-08-03 13:49:10 -07:00
Linus Torvalds
260f6f4fda Merge tag 'drm-next-2025-07-30' of https://gitlab.freedesktop.org/drm/kernel
Pull drm updates from Dave Airlie:
 "Highlights:

   - Intel xe enable Panthor Lake, started adding WildCat Lake

   - amdgpu has a bunch of reset improvments along with the usual IP
     updates

   - msm got VM_BIND support which is important for vulkan sparse memory

   - more drm_panic users

   - gpusvm common code to handle a bunch of core SVM work outside
     drivers.

  Detail summary:

  Changes outside drm subdirectory:
   - 'shrink_shmem_memory()' for better shmem/hibernate interaction
   - Rust support infrastructure:
      - make ETIMEDOUT available
      - add size constants up to SZ_2G
      - add DMA coherent allocation bindings
   - mtd driver for Intel GPU non-volatile storage
   - i2c designware quirk for Intel xe

  core:
   - atomic helpers: tune enable/disable sequences
   - add task info to wedge API
   - refactor EDID quirks
   - connector: move HDR sink to drm_display_info
   - fourcc: half-float and 32-bit float formats
   - mode_config: pass format info to simplify

  dma-buf:
   - heaps: Give CMA heap a stable name

  ci:
   - add device tree validation and kunit

  displayport:
   - change AUX DPCD access probe address
   - add quirk for DPCD probe
   - add panel replay definitions
   - backlight control helpers

  fbdev:
   - make CONFIG_FIRMWARE_EDID available on all arches

  fence:
   - fix UAF issues

  format-helper:
   - improve tests

  gpusvm:
   - introduce devmem only flag for allocation
   - add timeslicing support to GPU SVM

  ttm:
   - improve eviction

  sched:
   - tracing improvements
   - kunit improvements
   - memory leak fixes
   - reset handling improvements

  color mgmt:
   - add hardware gamma LUT handling helpers

  bridge:
   - add destroy hook
   - switch to reference counted drm_bridge allocations
   - tc358767: convert to devm_drm_bridge_alloc
   - improve CEC handling

  panel:
   - switch to reference counter drm_panel allocations
   - fwnode panel lookup
   - Huiling hl055fhv028c support
   - Raspberry Pi 7" 720x1280 support
   - edp: KDC KD116N3730A05, N160JCE-ELL CMN, N116BCJ-EAK
   - simple: AUO P238HAN01
   - st7701: Winstar wf40eswaa6mnn0
   - visionox: rm69299-shift
   - Renesas R61307, Renesas R69328 support
   - DJN HX83112B

  hdmi:
   - add CEC handling
   - YUV420 output support

  xe:
   - WildCat Lake support
   - Enable PanthorLake by default
   - mark BMG as SRIOV capable
   - update firmware recommendations
   - Expose media OA units
   - aux-bux support for non-volatile memory
   - MTD intel-dg driver for non-volatile memory
   - Expose fan control and voltage regulator in sysfs
   - restructure migration for multi-device
   - Restore GuC submit UAF fix
   - make GEM shrinker drm managed
   - SRIOV VF Post-migration recovery of GGTT nodes
   - W/A additions/reworks
   - Prefetch support for svm ranges
   - Don't allocate managed BO for each policy change
   - HWMON fixes for BMG
   - Create LRC BO without VM
   - PCI ID updates
   - make SLPC debugfs files optional
   - rework eviction rejection of bound external BOs
   - consolidate PAT programming logic for pre/post Xe2
   - init changes for flicker-free boot
   - Enable GuC Dynamic Inhibit Context switch

  i915:
   - drm_panic support for i915/xe
   - initial flip queue off by default for LNL/PNL
   - Wildcat Lake Display support
   - Support for DSC fractional link bpp
   - Support for simultaneous Panel Replay and Adaptive sync
   - Support for PTL+ double buffer LUT
   - initial PIPEDMC event handling
   - drm_panel_follower support
   - DPLL interface renames
   - allocate struct intel_display dynamically
   - flip queue preperation
   - abstract DRAM detection better
   - avoid GuC scheduling stalls
   - remove DG1 force probe requirement
   - fix MEI interrupt handler on RT kernels
   - use backlight control helpers for eDP
   - more shared display code refactoring

  amdgpu:
   - add userq slot to INFO ioctl
   - SR-IOV hibernation support
   - Suspend improvements
   - Backlight improvements
   - Use scaling for non-native eDP modes
   - cleaner shader updates for GC 9.x
   - Remove fence slab
   - SDMA fw checks for userq support
   - RAS updates
   - DMCUB updates
   - DP tunneling fixes
   - Display idle D3 support
   - Per queue reset improvements
   - initial smartmux support

  amdkfd:
   - enable KFD on loongarch
   - mtype fix for ext coherent system memory

  radeon:
   - CS validation additional GL extensions
   - drop console lock during suspend/resume
   - bump driver version

  msm:
   - VM BIND support
   - CI: infrastructure updates
   - UBWC single source of truth
   - decouple GPU and KMS support
   - DP: rework I/O accessors
   - DPU: SM8750 support
   - DSI: SM8750 support
   - GPU: X1-45 support and speedbin support for X1-85
   - MDSS: SM8750 support

  nova:
   - register! macro improvements
   - DMA object abstraction
   - VBIOS parser + fwsec lookup
   - sysmem flush page support
   - falcon: generic falcon boot code and HAL
   - FWSEC-FRTS: fb setup and load/execute

  ivpu:
   - Add Wildcat Lake support
   - Add turbo flag

  ast:
   - improve hardware generations implementation

  imx:
   - IMX8qxq Display Controller support

  lima:
   - Rockchip RK3528 GPU support

  nouveau:
   - fence handling cleanup

  panfrost:
   - MT8370 support
   - bo labeling
   - 64-bit register access

  qaic:
   - add RAS support

  rockchip:
   - convert inno_hdmi to a bridge

  rz-du:
   - add RZ/V2H(P) support
   - MIPI-DSI DCS support

  sitronix:
   - ST7567 support

  sun4i:
   - add H616 support

  tidss:
   - add TI AM62L support
   - AM65x OLDI bridge support

  bochs:
   - drm panic support

  vkms:
   - YUV and R* format support
   - use faux device

  vmwgfx:
   - fence improvements

  hyperv:
   - move out of simple
   - add drm_panic support"

* tag 'drm-next-2025-07-30' of https://gitlab.freedesktop.org/drm/kernel: (1479 commits)
  drm/tidss: oldi: convert to devm_drm_bridge_alloc() API
  drm/tidss: encoder: convert to devm_drm_bridge_alloc()
  drm/amdgpu: move reset support type checks into the caller
  drm/amdgpu/sdma7: re-emit unprocessed state on ring reset
  drm/amdgpu/sdma6: re-emit unprocessed state on ring reset
  drm/amdgpu/sdma5.2: re-emit unprocessed state on ring reset
  drm/amdgpu/sdma5: re-emit unprocessed state on ring reset
  drm/amdgpu/gfx12: re-emit unprocessed state on ring reset
  drm/amdgpu/gfx11: re-emit unprocessed state on ring reset
  drm/amdgpu/gfx10: re-emit unprocessed state on ring reset
  drm/amdgpu/gfx9.4.3: re-emit unprocessed state on kcq reset
  drm/amdgpu/gfx9: re-emit unprocessed state on kcq reset
  drm/amdgpu: Add WARN_ON to the resource clear function
  drm/amd/pm: Use cached metrics data on SMUv13.0.6
  drm/amd/pm: Use cached data for min/max clocks
  gpu: nova-core: fix bounds check in PmuLookupTableEntry::new
  drm/amdgpu: Replace HQD terminology with slots naming
  drm/amdgpu: Add user queue instance count in HW IP info
  drm/amd/amdgpu: Add helper functions for isp buffers
  drm/amd/amdgpu: Initialize swnode for ISP MFD device
  ...
2025-07-30 19:26:49 -07:00
Tamir Duberstein
386f285d88 rust: use kernel::{fmt,prelude::fmt!}
Reduce coupling to implementation details of the formatting machinery by
avoiding direct use for `core`'s formatting traits and macros.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250704-core-cstr-prepare-v1-3-a91524037783@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-21 01:16:35 +02:00
Danilo Krummrich
931d9251e4 rust: samples: dma: set DMA mask
Set a DMA mask for the `pci::Device` in the Rust DMA sample driver.

Reviewed-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250716150354.51081-6-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-07-19 19:37:17 +02:00
Miguel Ojeda
8ecb65b7b6 Merge tag 'alloc-next-v6.17-2025-07-15' of https://github.com/Rust-for-Linux/linux into rust-next
Pull alloc and DMA updates from Danilo Krummrich:

  Box:
   - Implement Borrow / BorrowMut for Box<T, A>.

  Vec:
   - Implement Default for Vec<T, A>.

   - Implement Borrow / BorrowMut for Vec<T, A>.

  DMA:
   - Clarify wording and be consistent in 'coherent' nomenclature.

   - Convert the read!() / write!() macros to return a Result.

   - Add as_slice() / write() methods in CoherentAllocation.

   - Fix doc-comment of dma_handle().

   - Expose count() and size() in CoherentAllocation and add the
     corresponding type invariants.

   - Implement CoherentAllocation::dma_handle_with_offset().

   - Require mutable reference for as_slice_mut() and write().

  MAINTAINERS:
   - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
     Stoakes as reviewers (thanks everyone).

* tag 'alloc-next-v6.17-2025-07-15' of https://github.com/Rust-for-Linux/linux:
  MAINTAINERS: add mm folks as reviewers to rust alloc
  rust: dma: require mutable reference for as_slice_mut() and write()
  rust: dma: add dma_handle_with_offset method to CoherentAllocation
  rust: dma: expose the count and size of CoherentAllocation
  rust: dma: fix doc-comment of dma_handle()
  rust: dma: add as_slice/write functions for CoherentAllocation
  rust: dma: convert the read/write macros to return Result
  rust: dma: clarify wording and be consistent in `coherent` nomenclature
  rust: alloc: implement `Borrow` and `BorrowMut` for `KBox`
  rust: alloc: implement `Borrow` and `BorrowMut` for `Vec`
  rust: vec: impl Default for Vec with any allocator
2025-07-15 23:42:55 +02:00
Alice Ryhl
60ecf796cd rust: uaccess: use newtype for user pointers
Currently, Rust code uses a typedef for unsigned long to represent
userspace addresses. This is unfortunate because it means that userspace
addresses could accidentally be mixed up with other integers. To
alleviate that, we introduce a new UserPtr struct that wraps a raw
pointer to represent a userspace address. By using a struct, type
checking enforces that userspace addresses cannot be mixed up with
anything else.

This is similar to the __user annotation in C that detects cases where
user pointers are mixed with non-user pointers.

Note that unlike __user pointers in C, this type is just a pointer
without a target type. This means that it can't detect cases such as
mixing up which struct this user pointer references. However, that is
okay due to the way this is intended to be used - generally, you create
a UserPtr in your ioctl callback from the provided usize *before*
dispatching on which ioctl is in use, and then after dispatching on the
ioctl you pass the UserPtr into a UserSliceReader or UserSliceWriter;
selecting the target type does not happen until you have obtained the
UserSliceReader/Writer.

The UserPtr type is not marked with #[derive(Debug)], which means that
it's not possible to print values of this type. This avoids ASLR
leakage.

The type is added to the prelude as it is a fairly fundamental type
similar to c_int. The wrapping_add() method is renamed to
wrapping_byte_add() for consistency with the method name found on raw
pointers.

Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250616-userptr-newtype-v3-1-5ff7b2d18d9e@google.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-14 23:52:45 +02:00
Danilo Krummrich
5f512533b7 samples: rust: pci: reset pci-testdev in unbind()
Reset the pci-testdev when the driver is unbound from its device.

Link: https://lore.kernel.org/r/20250621195118.124245-9-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-07-09 00:04:33 +02:00
Tamir Duberstein
65f8f0d4e0 rust: auxiliary: remove unnecessary import
`kernel::str::CStr` is included in the prelude.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250704-cstr-include-aux-v1-1-e1a404ae92ac@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-07-05 17:07:24 +02:00
Danilo Krummrich
f5d3ef25d2 rust: devres: get rid of Devres' inner Arc
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>
2025-06-28 18:08:50 +02:00
Igor Korotin
140a9d0437 samples: rust: add ACPI match table example to platform driver
Extend the Rust sample platform driver to probe using device/driver name
matching, OF ID table matching, or ACPI ID table matching.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://lore.kernel.org/r/20250620154552.299932-1-igor.korotin.linux@gmail.com
[ Use 'LNUXBEEF' as ACPI ID. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-26 23:26:15 +02:00
Danilo Krummrich
9da36b9fae samples: rust: platform: conditionally call Self::properties_parse()
Only call Self::properties_parse() when the FwNode is an OF node.

Once we add ACPI support, we don't want the ACPI device to fail probing
in Self::properties_parse().

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://lore.kernel.org/r/20250620152103.282763-1-igor.korotin.linux@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-25 18:10:12 +02:00
Danilo Krummrich
c69072d3a1 samples: rust: platform: don't call as_ref() repeatedly
In SampleDriver::probe() don't call pdev.as_ref() repeatedly, instead
introduce a dedicated &Device.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Reviewed-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20250620151849.281238-1-igor.korotin.linux@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-25 18:10:12 +02:00
Remo Senekowitsch
c79cbde9b7 samples: rust: platform: Add property child and reference args examples
Add some example usage of the device property methods for reading
DT/ACPI/swnode child nodes and reference args.

Signed-off-by: Remo Senekowitsch <remo@buenzli.dev>
Link: https://lore.kernel.org/r/20250616154511.1862909-4-remo@buenzli.dev
[ Convert 'child@{0,1}' to 'child-{0,1}'; skip child nodes without
  'compatible' property in of_unittest_platform_populate() as proposed
  by Rob Herring. - Danilo]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-25 17:48:41 +02:00
Guilherme Giacomo Simoes
bfb9e46b5b rust: macros: remove module!'s deprecated author key
Commit 38559da6af ("rust: module: introduce `authors` key") introduced
a new `authors` key to support multiple module authors, while keeping
the old `author` key for backward compatibility.

Now that most in-tree modules have migrated to `authors`, remove:
1. The deprecated `author` key support from the module macro
2. Legacy `author` entries from remaining modules

Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250609122200.179307-1-trintaeoitogc@gmail.com
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-24 01:01:13 +02:00
Abdiel Janulgue
fe58465905 rust: dma: convert the read/write macros to return Result
We could do better here by having the macros return `Result`,
so that we don't have to wrap these calls in a closure for
validation which is confusing.

Co-developed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/rust-for-linux/87h63qhz4q.fsf@kernel.org/
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Link: https://lore.kernel.org/r/20250602085444.1925053-3-abdiel.janulgue@gmail.com
[ Fix line length in dma_read!(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-23 15:34:13 +02:00
Remo Senekowitsch
2a1ea59de8 samples: rust: platform: Add property read examples
Add some example usage of the device property read methods for
DT/ACPI/swnode properties.

Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Co-developed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Remo Senekowitsch <remo@buenzli.dev>
Link: https://lore.kernel.org/r/20250611102908.212514-10-remo@buenzli.dev
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-13 01:14:13 +02:00
Linus Torvalds
b08494a8f7 Merge tag 'drm-next-2025-05-28' of https://gitlab.freedesktop.org/drm/kernel
Pull drm updates from Dave Airlie:
 "As part of building up nova-core/nova-drm pieces we've brought in some
  rust abstractions through this tree, aux bus being the main one, with
  devres changes also in the driver-core tree. Along with the drm core
  abstractions and enough nova-core/nova-drm to use them. This is still
  all stub work under construction, to build the nova driver upstream.

  The other big NVIDIA related one is nouveau adds support for
  Hopper/Blackwell GPUs, this required a new GSP firmware update to
  570.144, and a bunch of rework in order to support multiple fw
  interfaces.

  There is also the introduction of an asahi uapi header file as a
  precursor to getting the real driver in later, but to unblock
  userspace mesa packages while the driver is trapped behind rust
  enablement.

  Otherwise it's the usual mixture of stuff all over, amdgpu, i915/xe,
  and msm being the main ones, and some changes to vsprintf.

  new drivers:
   - bring in the asahi uapi header standalone
   - nova-drm: stub driver

  rust dependencies (for nova-core):
   - auxiliary
       - bus abstractions
       - driver registration
       - sample driver
   - devres changes from driver-core
   - revocable changes

  core:
   - add Apple fourcc modifiers
   - add virtio capset definitions
   - extend EXPORT_SYNC_FILE for timeline syncobjs
   - convert to devm_platform_ioremap_resource
   - refactor shmem helper page pinning
   - DP powerup/down link helpers
   - extended %p4cc in vsprintf.c to support fourcc prints
   - change vsprintf %p4cn to %p4chR, remove %p4cn
   - Add drm_file_err function
   - IN_FORMATS_ASYNC property
   - move sitronix from tiny to their own subdir

  rust:
   - add drm core infrastructure rust abstractions
     (device/driver, ioctl, file, gem)

  dma-buf:
   - adjust sg handling to not cache map on attach
   - allow setting dma-device for import
   - Add a helper to sort and deduplicate dma_fence arrays

  docs:
   - updated drm scheduler docs
   - fbdev todo update
   - fb rendering
   - actual brightness

  ttm:
   - fix delayed destroy resv object

  bridge:
   - add kunit tests
   - convert tc358775 to atomic
   - convert drivers to devm_drm_bridge_alloc
   - convert rk3066_hdmi to bridge driver

  scheduler:
   - add kunit tests

  panel:
   - refcount panels to improve lifetime handling
   - Powertip PH128800T004-ZZA01
   - NLT NL13676BC25-03F, Tianma TM070JDHG34-00
   - Himax HX8279/HX8279-D DDIC
   - Visionox G2647FB105
   - Sitronix ST7571
   - ZOTAC rotation quirk

  vkms:
   - allow attaching more displays

  i915:
   - xe3lpd display updates
   - vrr refactor
   - intel_display struct conversions
   - xe2hpd memory type identification
   - add link rate/count to i915_display_info
   - cleanup VGA plane handling
   - refactor HDCP GSC
   - fix SLPC wait boosting reference counting
   - add 20ms delay to engine reset
   - fix fence release on early probe errors

  xe:
   - SRIOV updates
   - BMG PCI ID update
   - support separate firmware for each GT
   - SVM fix, prelim SVM multi-device work
   - export fan speed
   - temp disable d3cold on BMG
   - backup VRAM in PM notifier instead of suspend/freeze
   - update xe_ttm_access_memory to use GPU for non-visible access
   - fix guc_info debugfs for VFs
   - use copy_from_user instead of __copy_from_user
   - append PCIe gen5 limitations to xe_firmware document

  amdgpu:
   - DSC cleanup
   - DC Scaling updates
   - Fused I2C-over-AUX updates
   - DMUB updates
   - Use drm_file_err in amdgpu
   - Enforce isolation updates
   - Use new dma_fence helpers
   - USERQ fixes
   - Documentation updates
   - SR-IOV updates
   - RAS updates
   - PSP 12 cleanups
   - GC 9.5 updates
   - SMU 13.x updates
   - VCN / JPEG SR-IOV updates

  amdkfd:
   - Update error messages for SDMA
   - Userptr updates
   - XNACK fixes

  radeon:
   - CIK doorbell cleanup

  nouveau:
   - add support for NVIDIA r570 GSP firmware
   - enable Hopper/Blackwell support

  nova-core:
   - fix task list
   - register definition infrastructure
   - move firmware into own rust module
   - register auxiliary device for nova-drm

  nova-drm:
   - initial driver skeleton

  msm:
   - GPU:
       - ACD (adaptive clock distribution) for X1-85
       - drop fictional address_space_size
       - improve GMU HFI response time out robustness
       - fix crash when throttling during boot
   - DPU:
       - use single CTL path for flushing on DPU 5.x+
       - improve SSPP allocation code for better sharing
       - Enabled SmartDMA on SM8150, SC8180X, SC8280XP, SM8550
       - Added SAR2130P support
       - Disabled DSC support on MSM8937, MSM8917, MSM8953, SDM660
   - DP:
       - switch to new audio helpers
       - better LTTPR handling
   - DSI:
       - Added support for SA8775P
       - Added SAR2130P support
   - HDMI:
       - Switched to use new helpers for ACR data
       - Fixed old standing issue of HPD not working in some cases

  amdxdna:
   - add dma-buf support
   - allow empty command submits

  renesas:
   - add dma-buf support
   - add zpos, alpha, blend support

  panthor:
   - fail properly for NO_MMAP bos
   - add SET_LABEL ioctl
   - debugfs BO dumping support

  imagination:
   - update DT bindings
   - support TI AM68 GPU

  hibmc:
   - improve interrupt handling and HPD support

  virtio:
   - add panic handler support

  rockchip:
   - add RK3588 support
   - add DP AUX bus panel support

  ivpu:
   - add heartbeat based hangcheck

  mediatek:
   - prepares support for MT8195/99 HDMIv2/DDCv2

  anx7625:
   - improve HPD

  tegra:
   - speed up firmware loading

* tag 'drm-next-2025-05-28' of https://gitlab.freedesktop.org/drm/kernel: (1627 commits)
  drm/nouveau/tegra: Fix error pointer vs NULL return in nvkm_device_tegra_resource_addr()
  drm/xe: Default auto_link_downgrade status to false
  drm/xe/guc: Make creation of SLPC debugfs files conditional
  drm/i915/display: Add check for alloc_ordered_workqueue() and alloc_workqueue()
  drm/i915/dp_mst: Work around Thunderbolt sink disconnect after SINK_COUNT_ESI read
  drm/i915/ptl: Use everywhere the correct DDI port clock select mask
  drm/nouveau/kms: add support for GB20x
  drm/dp: add option to disable zero sized address only transactions.
  drm/nouveau: add support for GB20x
  drm/nouveau/gsp: add hal for fifo.chan.doorbell_handle
  drm/nouveau: add support for GB10x
  drm/nouveau/gf100-: track chan progress with non-WFI semaphore release
  drm/nouveau/nv50-: separate CHANNEL_GPFIFO handling out from CHANNEL_DMA
  drm/nouveau: add helper functions for allocating pinned/cpu-mapped bos
  drm/nouveau: add support for GH100
  drm/nouveau: improve handling of 64-bit BARs
  drm/nouveau/gv100-: switch to volta semaphore methods
  drm/nouveau/gsp: support deeper page tables in COPY_SERVER_RESERVED_PDES
  drm/nouveau/gsp: init client VMMs with NV0080_CTRL_DMA_SET_PAGE_DIRECTORY
  drm/nouveau/gsp: fetch level shift and PDE from BAR2 VMM
  ...
2025-05-28 09:46:39 -07:00
Alexandre Courbot
80a8bcc652 samples: rust: select AUXILIARY_BUS instead of depending on it
CONFIG_AUXILIARY_BUS cannot be enabled explicitly, and unless we select
it we have no way to include it (and thus to enable the auxiliary driver
sample) unless a driver happens to do it for us.

Fixes: 96609a1969 ("samples: rust: add Rust auxiliary driver sample")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://lore.kernel.org/r/20250515-aux_bus-v2-1-47c70f96ae9b@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-15 20:59:32 +02:00
Andreas Hindborg
1bfb105051 rust: configfs: add a sample demonstrating configfs usage
Add a sample to the samples folder, demonstrating the intended use of the
Rust configfs API.

Link: https://lore.kernel.org/r/20250508-configfs-v8-2-8ebde6180edc@kernel.org
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-05-12 11:05:07 +02:00
Danilo Krummrich
b75a99e107 samples: rust: pci: take advantage of Devres::access()
For the I/O operations executed from the probe() method, take advantage
of Devres::access(), avoiding the atomic check and RCU read lock required
otherwise entirely.

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/20250428140137.468709-4-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-04 17:54:08 +02:00
Alexandre Courbot
0c848b3adb samples: rust: convert PCI rust sample driver to use try_access_with()
This method limits the scope of the revocable guard and is considered
safer to use for most cases, so let's showcase it here.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20250411-try_with-v4-2-f470ac79e2e2@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-04-22 17:21:16 +02:00
Danilo Krummrich
96609a1969 samples: rust: add Rust auxiliary driver sample
Add a sample Rust auxiliary driver based on a PCI driver for QEMU's
"pci-testdev" device.

The PCI driver only registers an auxiliary device, in order to make the
corresponding auxiliary driver probe.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250414131934.28418-6-dakr@kernel.org
[ Use `ok_or()` when accessing auxiliary::Device::parent(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-04-19 14:24:05 +02:00
Linus Torvalds
25601e8544 Merge tag 'char-misc-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc / IIO driver updates from Greg KH:
 "Here is the big set of char, misc, iio, and other smaller driver
  subsystems for 6.15-rc1. Lots of stuff in here, including:

   - loads of IIO changes and driver updates

   - counter driver updates

   - w1 driver updates

   - faux conversions for some drivers that were abusing the platform
     bus interface

   - coresight driver updates

   - rust miscdevice binding updates based on real-world-use

   - other minor driver updates

  All of these have been in linux-next with no reported issues for quite
  a while"

* tag 'char-misc-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits)
  samples: rust_misc_device: fix markup in top-level docs
  Coresight: Fix a NULL vs IS_ERR() bug in probe
  misc: lis3lv02d: convert to use faux_device
  tlclk: convert to use faux_device
  regulator: dummy: convert to use the faux device interface
  bus: mhi: host: Fix race between unprepare and queue_buf
  coresight: configfs: Constify struct config_item_type
  doc: iio: ad7380: describe offload support
  iio: ad7380: add support for SPI offload
  iio: light: Add check for array bounds in veml6075_read_int_time_ms
  iio: adc: ti-ads7924 Drop unnecessary function parameters
  staging: iio: ad9834: Use devm_regulator_get_enable()
  staging: iio: ad9832: Use devm_regulator_get_enable()
  iio: gyro: bmg160_spi: add of_match_table
  dt-bindings: iio: adc: Add i.MX94 and i.MX95 support
  iio: adc: ad7768-1: remove unnecessary locking
  Documentation: ABI: add wideband filter type to sysfs-bus-iio
  iio: adc: ad7768-1: set MOSI idle state to prevent accidental reset
  iio: adc: ad7768-1: Fix conversion result sign
  iio: adc: ad7124: Benefit of dev = indio_dev->dev.parent in ad7124_parse_channel_config()
  ...
2025-04-01 11:26:08 -07:00
Linus Torvalds
2cd5769fb0 Merge tag 'driver-core-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updatesk from Greg KH:
 "Here is the big set of driver core updates for 6.15-rc1. Lots of stuff
  happened this development cycle, including:

   - kernfs scaling changes to make it even faster thanks to rcu

   - bin_attribute constify work in many subsystems

   - faux bus minor tweaks for the rust bindings

   - rust binding updates for driver core, pci, and platform busses,
     making more functionaliy available to rust drivers. These are all
     due to people actually trying to use the bindings that were in
     6.14.

   - make Rafael and Danilo full co-maintainers of the driver core
     codebase

   - other minor fixes and updates"

* tag 'driver-core-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (52 commits)
  rust: platform: require Send for Driver trait implementers
  rust: pci: require Send for Driver trait implementers
  rust: platform: impl Send + Sync for platform::Device
  rust: pci: impl Send + Sync for pci::Device
  rust: platform: fix unrestricted &mut platform::Device
  rust: pci: fix unrestricted &mut pci::Device
  rust: device: implement device context marker
  rust: pci: use to_result() in enable_device_mem()
  MAINTAINERS: driver core: mark Rafael and Danilo as co-maintainers
  rust/kernel/faux: mark Registration methods inline
  driver core: faux: only create the device if probe() succeeds
  rust/faux: Add missing parent argument to Registration::new()
  rust/faux: Drop #[repr(transparent)] from faux::Registration
  rust: io: fix devres test with new io accessor functions
  rust: io: rename `io::Io` accessors
  kernfs: Move dput() outside of the RCU section.
  efi: rci2: mark bin_attribute as __ro_after_init
  rapidio: constify 'struct bin_attribute'
  firmware: qemu_fw_cfg: constify 'struct bin_attribute'
  powerpc/perf/hv-24x7: Constify 'struct bin_attribute'
  ...
2025-04-01 11:02:03 -07:00
Abdiel Janulgue
9901addae6 samples: rust: add Rust dma test sample driver
Add a simple driver to exercise the basics of the Rust DMA
coherent allocator bindings.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250317185345.2608976-4-abdiel.janulgue@gmail.com
[ Renamed Kconfig symbol and moved it up. Migrated to the new
  `authors` key in `module!`. Fixed module name in description
  and typo in commit message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-20 21:44:46 +01:00
Alice Ryhl
a24b18aa4f samples: rust_misc_device: fix markup in top-level docs
The meaning of /// is to document the thing that comes after it, so
currently the example is documentation for the `use core::pin::Pin;`
statement. To write top-level docs (and have them rendered as such in
the html by rustdoc), use //! instead.

This does not change the contents of the docs at all. The only change is
changing /// to //!.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 8d9b095b8f ("samples: rust_misc_device: Provide an example C program to exercise functionality")
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Link: https://lore.kernel.org/r/20250313-rust_misc_device_tld-v1-1-a519bced9a6d@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-17 08:06:07 +01:00
Danilo Krummrich
4d320e30ee rust: platform: fix unrestricted &mut platform::Device
As by now, platform::Device is implemented as:

	#[derive(Clone)]
	pub struct Device(ARef<device::Device>);

This may be convenient, but has the implication that drivers can call
device methods that require a mutable reference concurrently at any
point of time.

Instead define platform::Device as

	pub struct Device<Ctx: DeviceContext = Normal>(
		Opaque<bindings::platform_dev>,
		PhantomData<Ctx>,
	);

and manually implement the AlwaysRefCounted trait.

With this we can implement methods that should only be called from
bus callbacks (such as probe()) for platform::Device<Core>. Consequently,
we make this type accessible in bus callbacks only.

Arbitrary references taken by the driver are still of type
ARef<platform::Device> and hence don't provide access to methods that are
reserved for bus callbacks.

Fixes: 683a63befc ("rust: platform: add basic platform device / driver abstractions")
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250314160932.100165-5-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-17 08:04:25 +01:00
Danilo Krummrich
7b948a2af6 rust: pci: fix unrestricted &mut pci::Device
As by now, pci::Device is implemented as:

	#[derive(Clone)]
	pub struct Device(ARef<device::Device>);

This may be convenient, but has the implication that drivers can call
device methods that require a mutable reference concurrently at any
point of time.

Instead define pci::Device as

	pub struct Device<Ctx: DeviceContext = Normal>(
		Opaque<bindings::pci_dev>,
		PhantomData<Ctx>,
	);

and manually implement the AlwaysRefCounted trait.

With this we can implement methods that should only be called from
bus callbacks (such as probe()) for pci::Device<Core>. Consequently, we
make this type accessible in bus callbacks only.

Arbitrary references taken by the driver are still of type
ARef<pci::Device> and hence don't provide access to methods that are
reserved for bus callbacks.

Fixes: 1bd8b6b2c5 ("rust: pci: add basic PCI device / driver abstractions")
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250314160932.100165-4-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-17 08:04:25 +01:00
Guilherme Giacomo Simoes
38559da6af rust: module: introduce authors key
In the `module!` macro, the `author` field is currently of type `String`.

Since modules can have multiple authors, this limitation prevents
specifying more than one.

Add an `authors` field as `Option<Vec<String>>` to allow creating
modules with multiple authors, and change the documentation and all
current users to use it. Eventually, the single `author` field may
be removed.

[ The `modinfo` key needs to still be `author`; otherwise, tooling
  may not work properly, e.g.:

      $ modinfo --author samples/rust/rust_print.ko
      Rust for Linux Contributors

  I have also kept the original `author` field (undocumented), so
  that we can drop it more easily in a kernel cycle or two.

    - Miguel ]

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/244
Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Link: https://lore.kernel.org/r/20250309175712.845622-2-trintaeoitogc@gmail.com
[ Fixed `modinfo` key. Kept `author` field. Reworded message
  accordingly. Updated my email. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-10 15:12:17 +01:00
Lyude Paul
95cb0cb546 rust/faux: Add missing parent argument to Registration::new()
A little late in the review of the faux device interface, we added the
ability to specify a parent device when creating new faux devices - but
this never got ported over to the rust bindings. So, let's add the missing
argument now so we don't have to convert other users later down the line.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250227193522.198344-1-lyude@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-27 18:03:17 -08:00
Fiona Behrens
354fd6e86f rust: io: rename io::Io accessors
Rename the I/O accessors provided by `Io` to encode the type as
number instead of letter. This is in preparation for Port I/O support
to use a trait for generic accessors.

Add a `c_fn` argument to the accessor generation macro to translate
between rust and C names.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/PIO.20support/near/499460541
Signed-off-by: Fiona Behrens <me@kloenk.dev>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250217-io-generic-rename-v1-1-06d97a9e3179@kloenk.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-22 15:44:19 +01:00
Lyude Paul
78418f300d rust/kernel: Add faux device bindings
This introduces a module for working with faux devices in rust, along with
adding sample code to show how the API is used. Unlike other types of
devices, we don't provide any hooks for device probe/removal - since these
are optional for the faux API and are unnecessary in rust.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Maíra Canal <mairacanal@riseup.net>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/2025021026-exert-accent-b4c6@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-13 16:58:58 +01:00
Linus Torvalds
2ab002c755 Merge tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
 "Here is the big set of driver core and debugfs updates for 6.14-rc1.

  Included in here is a bunch of driver core, PCI, OF, and platform rust
  bindings (all acked by the different subsystem maintainers), hence the
  merge conflict with the rust tree, and some driver core api updates to
  mark things as const, which will also require some fixups due to new
  stuff coming in through other trees in this merge window.

  There are also a bunch of debugfs updates from Al, and there is at
  least one user that does have a regression with these, but Al is
  working on tracking down the fix for it. In my use (and everyone
  else's linux-next use), it does not seem like a big issue at the
  moment.

  Here's a short list of the things in here:

   - driver core rust bindings for PCI, platform, OF, and some i/o
     functions.

     We are almost at the "write a real driver in rust" stage now,
     depending on what you want to do.

   - misc device rust bindings and a sample driver to show how to use
     them

   - debugfs cleanups in the fs as well as the users of the fs api for
     places where drivers got it wrong or were unnecessarily doing
     things in complex ways.

   - driver core const work, making more of the api take const * for
     different parameters to make the rust bindings easier overall.

   - other small fixes and updates

  All of these have been in linux-next with all of the aforementioned
  merge conflicts, and the one debugfs issue, which looks to be resolved
  "soon""

* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  rust: device: Use as_char_ptr() to avoid explicit cast
  rust: device: Replace CString with CStr in property_present()
  devcoredump: Constify 'struct bin_attribute'
  devcoredump: Define 'struct bin_attribute' through macro
  rust: device: Add property_present()
  saner replacement for debugfs_rename()
  orangefs-debugfs: don't mess with ->d_name
  octeontx2: don't mess with ->d_parent or ->d_parent->d_name
  arm_scmi: don't mess with ->d_parent->d_name
  slub: don't mess with ->d_name
  sof-client-ipc-flood-test: don't mess with ->d_name
  qat: don't mess with ->d_name
  xhci: don't mess with ->d_iname
  mtu3: don't mess wiht ->d_iname
  greybus/camera - stop messing with ->d_iname
  mediatek: stop messing with ->d_iname
  netdevsim: don't embed file_operations into your structs
  b43legacy: make use of debugfs_get_aux()
  b43: stop embedding struct file_operations into their objects
  carl9170: stop embedding file_operations into their objects
  ...
2025-01-28 12:25:12 -08:00
Xiangfei Ding
47cb6bf786 rust: use derive(CoercePointee) on rustc >= 1.84.0
The `kernel` crate relies on both `coerce_unsized` and `dispatch_from_dyn`
unstable features.

Alice Ryhl has proposed [1] the introduction of the unstable macro
`SmartPointer` to reduce such dependence, along with a RFC patch [2].
Since Rust 1.81.0 this macro, later renamed to `CoercePointee` in
Rust 1.84.0 [3], has been fully implemented with the naming discussion
resolved.

This feature is now on track to stabilization in the language.
In order to do so, we shall start using this macro in the `kernel` crate
to prove the functionality and utility of the macro as the justification
of its stabilization.

This patch makes this switch in such a way that the crate remains
backward compatible with older Rust compiler versions,
via the new Kconfig option `RUSTC_HAS_COERCE_POINTEE`.

A minimal demonstration example is added to the
`samples/rust/rust_print_main.rs` module.

Link: https://rust-lang.github.io/rfcs/3621-derive-smart-pointer.html [1]
Link: https://lore.kernel.org/all/20240823-derive-smart-pointer-v1-1-53769cd37239@google.com/ [2]
Link: https://github.com/rust-lang/rust/pull/131284 [3]
Signed-off-by: Xiangfei Ding <dingxiangfei2009@gmail.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241203205050.679106-2-dingxiangfei2009@gmail.com
[ Fixed version to 1.84. Renamed option to `RUSTC_HAS_COERCE_POINTEE`
  to match `CC_HAS_*` ones. Moved up new config option, closer to the
  `CC_HAS_*` ones. Simplified Kconfig line. Fixed typos and slightly
  reworded example and commit. Added Link to PR. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-13 23:45:30 +01:00
Danilo Krummrich
b2e8a83242 samples: rust: add Rust platform sample driver
Add a sample Rust platform driver illustrating the usage of the platform
bus abstractions.

This driver probes through either a match of device / driver name or a
match within the OF ID table.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Tested-by: Fabien Parent <fabien.parent@linaro.org>
Link: https://lore.kernel.org/r/20241219170425.12036-16-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20 17:43:02 +01:00
Danilo Krummrich
685376d18e samples: rust: add Rust PCI sample driver
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 <dakr@kernel.org>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20241219170425.12036-12-dakr@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20 17:21:04 +01:00
Miguel Ojeda
27c7518e7f rust: finish using custom FFI integer types
In the last kernel cycle we migrated most of the `core::ffi` cases in
commit d072acda48 ("rust: use custom FFI integer types"):

    Currently FFI integer types are defined in libcore. This commit
    creates the `ffi` crate and asks bindgen to use that crate for FFI
    integer types instead of `core::ffi`.

    This commit is preparatory and no type changes are made in this
    commit yet.

Finish now the few remaining/new cases so that we perform the actual
remapping in the next commit as planned.

Acked-by: Jocelyn Falempe <jfalempe@redhat.com> # drm
Link: https://lore.kernel.org/rust-for-linux/CANiq72m_rg42SvZK=bF2f0yEoBLVA33UBhiAsv8THhVu=G2dPA@mail.gmail.com/
Link: https://lore.kernel.org/all/cc9253fa-9d5f-460b-9841-94948fb6580c@redhat.com/
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-12-16 21:48:45 +01:00
Lee Jones
8d9b095b8f samples: rust_misc_device: Provide an example C program to exercise functionality
Here is the expected output (manually spliced together):

USERSPACE: Opening /dev/rust-misc-device for reading and writing
KERNEL: rust_misc_device: Opening Rust Misc Device Sample
USERSPACE: Calling Hello
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Hello from the Rust Misc Device
USERSPACE: Fetching initial value
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Copying data to userspace (value: 0)
USERSPACE: Submitting new value (1)
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Copying data from userspace (value: 1)
USERSPACE: Fetching new value
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> Copying data to userspace (value: 1)
USERSPACE: Attempting to call in to an non-existent IOCTL
KERNEL: rust_misc_device: IOCTLing Rust Misc Device Sample
KERNEL: rust_misc_device: -> IOCTL not recognised: 20992
USERSPACE: ioctl: Succeeded to fail - this was expected: Inappropriate ioctl for device
USERSPACE: Closing /dev/rust-misc-device
KERNEL: rust_misc_device: Exiting the Rust Misc Device Sample
USERSPACE: Success

Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20241213134715.601415-6-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-16 16:12:56 +01:00
Lee Jones
42523ceba5 samples: rust_misc_device: Demonstrate additional get/set value functionality
Expand the complexity of the sample driver by providing the ability to
get and set an integer.  The value is protected by a mutex.

Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20241213134715.601415-4-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-16 16:12:53 +01:00
Lee Jones
fdb1ac6c30 samples: rust: Provide example using the new Rust MiscDevice abstraction
This sample driver demonstrates the following basic operations:

* Register a Misc Device
* Create /dev/rust-misc-device
* Provide open call-back for the aforementioned character device
* Operate on the character device via a simple ioctl()
* Provide close call-back for the character device

Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241213134715.601415-3-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-16 16:12:45 +01:00
Linus Torvalds
798bb342e0 Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux
Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Enable a series of lints, including safety-related ones, e.g. the
     compiler will now warn about missing safety comments, as well as
     unnecessary ones. How safety documentation is organized is a
     frequent source of review comments, thus having the compiler guide
     new developers on where they are expected (and where not) is very
     nice.

   - Start using '#[expect]': an interesting feature in Rust (stabilized
     in 1.81.0) that makes the compiler warn if an expected warning was
     _not_ emitted. This is useful to avoid forgetting cleaning up
     locally ignored diagnostics ('#[allow]'s).

   - Introduce '.clippy.toml' configuration file for Clippy, the Rust
     linter, which will allow us to tweak its behaviour. For instance,
     our first use cases are declaring a disallowed macro and, more
     importantly, enabling the checking of private items.

   - Lints-related fixes and cleanups related to the items above.

   - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the
     kernel into stable Rust, one of the major pieces of the puzzle is
     the support to write custom types that can be used as 'self', i.e.
     as receivers, since the kernel needs to write types such as 'Arc'
     that common userspace Rust would not. 'arbitrary_self_types' has
     been accepted to become stable, and this is one of the steps
     required to get there.

   - Remove usage of the 'new_uninit' unstable feature.

   - Use custom C FFI types. Includes a new 'ffi' crate to contain our
     custom mapping, instead of using the standard library 'core::ffi'
     one. The actual remapping will be introduced in a later cycle.

   - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize'
     instead of 32/64-bit integers.

   - Fix 'size_t' in bindgen generated prototypes of C builtins.

   - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue
     in the projects, which we managed to trigger with the upcoming
     tracepoint support. It includes a build test since some
     distributions backported the fix (e.g. Debian -- thanks!). All
     major distributions we list should be now OK except Ubuntu non-LTS.

  'macros' crate:

   - Adapt the build system to be able run the doctests there too; and
     clean up and enable the corresponding doctests.

  'kernel' crate:

   - Add 'alloc' module with generic kernel allocator support and remove
     the dependency on the Rust standard library 'alloc' and the
     extension traits we used to provide fallible methods with flags.

     Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'.
     Add the 'Box' type (a heap allocation for a single value of type
     'T' that is also generic over an allocator and considers the
     kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add
     'ArrayLayout' type. Add 'Vec' (a contiguous growable array type)
     and its shorthand aliases '{K,V,KV}Vec', including iterator
     support.

     For instance, now we may write code such as:

         let mut v = KVec::new();
         v.push(1, GFP_KERNEL)?;
         assert_eq!(&v, &[1]);

     Treewide, move as well old users to these new types.

   - 'sync' module: add global lock support, including the
     'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types
     and the 'global_lock!' macro. Add the 'Lock::try_lock' method.

   - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make
     conversion functions public.

   - 'page' module: add 'page_align' function.

   - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes'
     traits.

   - 'block::mq::request' module: improve rendered documentation.

   - 'types' module: extend 'Opaque' type documentation and add simple
     examples for the 'Either' types.

  drm/panic:

   - Clean up a series of Clippy warnings.

  Documentation:

   - Add coding guidelines for lints and the '#[expect]' feature.

   - Add Ubuntu to the list of distributions in the Quick Start guide.

  MAINTAINERS:

   - Add Danilo Krummrich as maintainer of the new 'alloc' module.

  And a few other small cleanups and fixes"

* tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits)
  rust: alloc: Fix `ArrayLayout` allocations
  docs: rust: remove spurious item in `expect` list
  rust: allow `clippy::needless_lifetimes`
  rust: warn on bindgen < 0.69.5 and libclang >= 19.1
  rust: use custom FFI integer types
  rust: map `__kernel_size_t` and friends also to usize/isize
  rust: fix size_t in bindgen prototypes of C builtins
  rust: sync: add global lock support
  rust: macros: enable the rest of the tests
  rust: macros: enable paste! use from macro_rules!
  rust: enable macros::module! tests
  rust: kbuild: expand rusttest target for macros
  rust: types: extend `Opaque` documentation
  rust: block: fix formatting of `kernel::block::mq::request` module
  rust: macros: fix documentation of the paste! macro
  rust: kernel: fix THIS_MODULE header path in ThisModule doc comment
  rust: page: add Rust version of PAGE_ALIGN
  rust: helpers: remove unnecessary header includes
  rust: exports: improve grammar in commentary
  drm/panic: allow verbose version check
  ...
2024-11-26 14:00:26 -08:00
Miguel Ojeda
22193c586b samples: rust: fix rust_print build making it a combined module
The `rust_print` module, when built as a module, fails to build with:

    ERROR: modpost: missing MODULE_LICENSE() in samples/rust/rust_print_events.o
    ERROR: modpost: "__tracepoint_rust_sample_loaded" [samples/rust/rust_print.ko] undefined!
    ERROR: modpost: "rust_do_trace_rust_sample_loaded" [samples/rust/rust_print.ko] undefined!

Fix it by building it as a combined one.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Trevor Gross <tmgross@umich.edu>
Cc: "Linux Next Mailing List" <linux-next@vger.kernel.org>
Link: https://lore.kernel.org/20241111220805.708889-1-ojeda@kernel.org
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20241108152149.28459a72@canb.auug.org.au/
Fixes: 91d39024e1 ("rust: samples: add tracepoint to Rust sample")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-12 09:21:48 -05:00
Alice Ryhl
91d39024e1 rust: samples: add tracepoint to Rust sample
This updates the Rust printing sample to invoke a tracepoint. This
ensures that we have a user in-tree from the get-go even though the
patch is being merged before its real user.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anup Patel <apatel@ventanamicro.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Conor Dooley <conor.dooley@microchip.com>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>
Link: https://lore.kernel.org/20241030-tracepoint-v12-3-eec7f0f8ad22@google.com
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-04 16:21:44 -05:00
Danilo Krummrich
58eff8e872 rust: treewide: switch to the kernel Vec type
Now that we got the kernel `Vec` in place, convert all existing `Vec`
users to make use of it.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-20-dakr@kernel.org
[ Converted `kasan_test_rust.rs` too, as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15 23:10:32 +02:00
Miguel Ojeda
1f9ed17254 rust: start using the #[expect(...)] attribute
In Rust, it is possible to `allow` particular warnings (diagnostics,
lints) locally, making the compiler ignore instances of a given warning
within a given function, module, block, etc.

It is similar to `#pragma GCC diagnostic push` + `ignored` + `pop` in C:

    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wunused-function"
    static void f(void) {}
    #pragma GCC diagnostic pop

But way less verbose:

    #[allow(dead_code)]
    fn f() {}

By that virtue, it makes it possible to comfortably enable more
diagnostics by default (i.e. outside `W=` levels) that may have some
false positives but that are otherwise quite useful to keep enabled to
catch potential mistakes.

The `#[expect(...)]` attribute [1] takes this further, and makes the
compiler warn if the diagnostic was _not_ produced. For instance, the
following will ensure that, when `f()` is called somewhere, we will have
to remove the attribute:

    #[expect(dead_code)]
    fn f() {}

If we do not, we get a warning from the compiler:

    warning: this lint expectation is unfulfilled
     --> x.rs:3:10
      |
    3 | #[expect(dead_code)]
      |          ^^^^^^^^^
      |
      = note: `#[warn(unfulfilled_lint_expectations)]` on by default

This means that `expect`s do not get forgotten when they are not needed.

See the next commit for more details, nuances on its usage and
documentation on the feature.

The attribute requires the `lint_reasons` [2] unstable feature, but it
is becoming stable in 1.81.0 (to be released on 2024-09-05) and it has
already been useful to clean things up in this patch series, finding
cases where the `allow`s should not have been there.

Thus, enable `lint_reasons` and convert some of our `allow`s to `expect`s
where possible.

This feature was also an example of the ongoing collaboration between
Rust and the kernel -- we tested it in the kernel early on and found an
issue that was quickly resolved [3].

Cc: Fridtjof Stoldt <xfrednet@gmail.com>
Cc: Urgau <urgau@numericable.fr>
Link: https://rust-lang.github.io/rfcs/2383-lint-reasons.html#expect-lint-attribute [1]
Link: https://github.com/rust-lang/rust/issues/54503 [2]
Link: https://github.com/rust-lang/rust/issues/114557 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-18-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07 21:39:57 +02:00
Miguel Ojeda
8577c9dca7 rust: replace clippy::dbg_macro with disallowed_macros
Back when we used Rust 1.60.0 (before Rust was merged in the kernel),
we added `-Wclippy::dbg_macro` to the compilation flags. This worked
great with our custom `dbg!` macro (vendored from `std`, but slightly
modified to use the kernel printing facilities).

However, in the very next version, 1.61.0, it stopped working [1] since
the lint started to use a Rust diagnostic item rather than a path to find
the `dbg!` macro [1]. This behavior remains until the current nightly
(1.83.0).

Therefore, currently, the `dbg_macro` is not doing anything, which
explains why we can invoke `dbg!` in samples/rust/rust_print.rs`, as well
as why changing the `#[allow()]`s to `#[expect()]`s in `std_vendor.rs`
doctests does not work since they are not fulfilled.

One possible workaround is using `rustc_attrs` like the standard library
does. However, this is intended to be internal, and we just started
supporting several Rust compiler versions, so it is best to avoid it.

Therefore, instead, use `disallowed_macros`. It is a stable lint and
is more flexible (in that we can provide different macros), although
its diagnostic message(s) are not as nice as the specialized one (yet),
and does not allow to set different lint levels per macro/path [2].

In turn, this requires allowing the (intentional) `dbg!` use in the
sample, as one would have expected.

Finally, in a single case, the `allow` is fixed to be an inner attribute,
since otherwise it was not being applied.

Link: https://github.com/rust-lang/rust-clippy/issues/11303 [1]
Link: https://github.com/rust-lang/rust-clippy/issues/11307 [2]
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-13-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07 21:39:05 +02:00
Wedson Almeida Filho
cc41670e06 rust: sync: update Arc and UniqueArc to take allocation flags
We also remove the `try_` prefix to align with how `Box` and `Vec` are
providing methods now.

`init` is temporarily updated with uses of GFP_KERNEL. These will be
updated in a subsequent patch to take flags as well.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-9-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16 22:50:04 +02:00