Switch the read_callback_file() documentation example from
core::sync::atomic::AtomicU32 to the kernel's Atomic because Rust
native atomics are not allowed to use in kernel.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251203000411.30434-1-fujita.tomonori@gmail.com
[ Use kernel vertical import style. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

C-String literals were added in Rust 1.77. Replace instances of
`kernel::c_str!` with C-String literals where possible.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20251222-cstr-driver-core-v1-6-1142a177d0fd@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Convert all imports in the debugfs Rust module to use "kernel vertical"
style.

With this subsequent patches neither introduce unrelated changes nor
leave an inconsistent import pattern.

While at it, drop unnecessary imports covered by prelude::*.

Link: https://docs.kernel.org/rust/coding-guidelines.html#imports
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20251218165626.450264-1-dakr@kernel.org
[ Apply the same change to the debugfs sample code. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Pull driver core updates from Danilo Krummrich:
 "Arch Topology:
   - Move parse_acpi_topology() from arm64 to common code for reuse in
     RISC-V

  CPU:
   - Expose housekeeping CPUs through /sys/devices/system/cpu/housekeeping
   - Print a newline (or 0x0A) instead of '(null)' reading
     /sys/devices/system/cpu/nohz_full when nohz_full= is not set

  debugfs
   - Remove (broken) 'no-mount' mode
   - Remove redundant access mode checks in debugfs_get_tree() and
     debugfs_create_*() functions

  Devres:
   - Remove unused devm_free_percpu() helper
   - Move devm_alloc_percpu() from device.h to devres.h

  Firmware Loader:
   - Replace simple_strtol() with kstrtoint()
   - Do not call cancel_store() when no upload is in progress

  kernfs:
   - Increase struct super_block::maxbytes to MAX_LFS_FILESIZE
   - Fix a missing unwind path in __kernfs_new_node()

  Misc:
   - Increase the name size in struct auxiliary_device_id to 40
     characters
   - Replace system_unbound_wq with system_dfl_wq and add WQ_PERCPU to
     alloc_workqueue()

  Platform:
   - Replace ERR_PTR() with IOMEM_ERR_PTR() in platform ioremap
     functions

  Rust:
   - Auxiliary:
      - Unregister auxiliary device on parent device unbind
      - Move parent() to impl Device; implement device context aware
        parent() for Device<Bound>
      - Illustrate how to safely obtain a driver's device private data
        when calling from an auxiliary driver into the parant device
        driver

   - DebugFs:
      - Implement support for binary large objects

   - Device:
      - Let probe() return the driver's device private data as pinned
        initializer, i.e. impl PinInit<Self, Error>
      - Implement safe accessor for a driver's device private data for
        Device<Bound> (returned reference can't out-live driver binding
        and guarantees the correct private data type)
      - Implement AsBusDevice trait, to be used by class device
        abstractions to derive the bus device type of the parent device

   - DMA:
      - Store raw pointer of allocation as NonNull
      - Use start_ptr() and start_ptr_mut() to inherit correct
        mutability of self

   - FS:
      - Add file::Offset type alias

   - I2C:
      - Add abstractions for I2C device / driver infrastructure
      - Implement abstractions for manual I2C device registrations

   - I/O:
      - Use "kernel vertical" style for imports
      - Define ResourceSize as resource_size_t
      - Move ResourceSize to top-level I/O module
      - Add type alias for phys_addr_t
      - Implement Rust version of read_poll_timeout_atomic()

   - PCI:
      - Use "kernel vertical" style for imports
      - Move I/O and IRQ infrastructure to separate files
      - Add support for PCI interrupt vectors
      - Implement TryInto<IrqRequest<'a>> for IrqVector<'a> to convert
        an IrqVector bound to specific pci::Device into an IrqRequest
        bound to the same pci::Device's parent Device
      - Leverage pin_init_scope() to get rid of redundant Result in IRQ
        methods

   - PinInit:
      - Add {pin_}init_scope() to execute code before creating an
        initializer

   - Platform:
      - Leverage pin_init_scope() to get rid of redundant Result in IRQ
        methods

   - Timekeeping:
      - Implement abstraction of udelay()

   - Uaccess:
      - Implement read_slice_partial() and read_slice_file() for
        UserSliceReader
      - Implement write_slice_partial() and write_slice_file() for
        UserSliceWriter

  sysfs:
   - Prepare the constification of struct attribute"

* tag 'driver-core-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (75 commits)
  rust: pci: fix build failure when CONFIG_PCI_MSI is disabled
  debugfs: Fix default access mode config check
  debugfs: Remove broken no-mount mode
  debugfs: Remove redundant access mode checks
  driver core: Check drivers_autoprobe for all added devices
  driver core: WQ_PERCPU added to alloc_workqueue users
  driver core: replace use of system_unbound_wq with system_dfl_wq
  tick/nohz: Expose housekeeping CPUs in sysfs
  tick/nohz: avoid showing '(null)' if nohz_full= not set
  sysfs/cpu: Use DEVICE_ATTR_RO for nohz_full attribute
  kernfs: fix memory leak of kernfs_iattrs in __kernfs_new_node
  fs/kernfs: raise sb->maxbytes to MAX_LFS_FILESIZE
  mod_devicetable: Bump auxiliary_device_id name size
  sysfs: simplify attribute definition macros
  samples/kobject: constify 'struct foo_attribute'
  samples/kobject: add is_visible() callback to attribute group
  sysfs: attribute_group: enable const variants of is_visible()
  sysfs: introduce __SYSFS_FUNCTION_ALTERNATIVE()
  sysfs: transparently handle const pointers in ATTRIBUTE_GROUPS()
  sysfs: attribute_group: allow registration of const attribute
  ...

Add support for creating binary debugfs files via ScopedDir. This
mirrors the existing functionality for Dir, but without producing an
owning handle -- files are automatically removed when the associated
Scope is dropped.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Extend Rust debugfs binary support to allow exposing data stored in
common smart pointers and heap-allocated collections.

- Implement BinaryWriter for Box<T>, Pin<Box<T>>, Arc<T>, and Vec<T>.
- Introduce BinaryReaderMut for mutable binary access with outer locks.
- Implement BinaryReaderMut for Box<T>, Vec<T>, and base types.
- Update BinaryReader to delegate to BinaryReaderMut for Mutex<T>,
  Box<T>, Pin<Box<T>> and Arc<T>.

This enables debugfs files to directly expose or update data stored
inside heap-allocated, reference-counted, or lock-protected containers
without manual dereferencing or locking.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Introduce support for read-only, write-only, and read-write binary files
in Rust debugfs. This adds:

- BinaryWriter and BinaryReader traits for writing to and reading from
  user slices in binary form.
- New Dir methods: read_binary_file(), write_binary_file(),
  `read_write_binary_file`.
- Corresponding FileOps implementations: BinaryReadFile,
  BinaryWriteFile, BinaryReadWriteFile.

This allows kernel modules to expose arbitrary binary data through
debugfs, with proper support for offsets and partial reads/writes.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Reduce coupling to implementation details of the formatting machinery by
avoiding direct use for `core`'s formatting traits and macros.

This backslid in commit 40ecc49466c8 ("rust: debugfs: Add support for
callback-based files") and commit 5e40b591cb46 ("rust: debugfs: Add
support for read-only files").

Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://patch.msgid.link/20251018-cstr-core-v18-7-9378a54385f8@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Introduces the concept of a `ScopedDir`, which allows for the creation
of debugfs directories and files that are tied to the lifetime of a
particular data structure. This ensures that debugfs entries do not
outlive the data they refer to.

The new `Dir::scope` method creates a new directory that is owned by a
`Scope` handle. All files and subdirectories created within this scope
are automatically cleaned up when the `Scope` is dropped.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250904-debugfs-rust-v11-6-7d12a165685a@google.com
[ Fix up Result<(), Error> -> Result; fix spurious backtick in
  doc-comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Extends the `debugfs` API to support creating files with content
generated and updated by callbacks. This is done via the
`read_callback_file`, `write_callback_file`, and
`read_write_callback_file` methods.

These methods allow for more flexible file definition, either because
the type already has a `Writer` or `Reader` method that doesn't
do what you'd like, or because you cannot implement it (e.g. because
it's a type defined in another crate or a primitive type).

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250904-debugfs-rust-v11-4-7d12a165685a@google.com
[ Fix up Result<(), Error> -> Result. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>