Commit Graph

6 Commits

Author SHA1 Message Date
Linus Torvalds 416f99c3b1 Driver core changes for 6.19-rc1
- 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
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Merge tag 'driver-core-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

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
  ...
2025-12-05 21:29:02 -08:00
Linus Torvalds 784faa8eca Rust changes for v6.19
Toolchain and infrastructure:
 
  - Add support for 'syn'.
 
      Syn is a parsing library for parsing a stream of Rust tokens into a
      syntax tree of Rust source code.
 
      Currently this library is geared toward use in Rust procedural
      macros, but contains some APIs that may be useful more generally.
 
    'syn' allows us to greatly simplify writing complex macros such as
    'pin-init' (Benno has already prepared the 'syn'-based version). We
    will use it in the 'macros' crate too.
 
    'syn' is the most downloaded Rust crate (according to crates.io), and
    it is also used by the Rust compiler itself. While the amount of code
    is substantial, there should not be many updates needed for these
    crates, and even if there are, they should not be too big, e.g. +7k
    -3k lines across the 3 crates in the last year.
 
    'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
    I only modified their code to remove a third dependency
    ('unicode-ident') and to add the SPDX identifiers. The code can be
    easily verified to exactly match upstream with the provided scripts.
 
    They are all licensed under "Apache-2.0 OR MIT", like the other
    vendored 'alloc' crate we had for a while.
 
    Please see the merge commit with the cover letter for more context.
 
  - Allow 'unreachable_pub' and 'clippy::disallowed_names' for doctests.
 
    Examples (i.e. doctests) may want to do things like show public items
    and use names such as 'foo'.
 
    Nevertheless, we still try to keep examples as close to real code as
    possible (this is part of why running Clippy on doctests is important
    for us, e.g. for safety comments, which userspace Rust does not
    support yet but we are stricter).
 
 'kernel' crate:
 
  - Replace our custom 'CStr' type with 'core::ffi::CStr'.
 
    Using the standard library type reduces our custom code footprint,
    and we retain needed custom functionality through an extension trait
    and a new 'fmt!' macro which replaces the previous 'core' import.
 
    This started in 6.17 and continued in 6.18, and we finally land the
    replacement now. This required quite some stamina from Tamir, who
    split the changes in steps to prepare for the flag day change here.
 
  - Replace 'kernel::c_str!' with C string literals.
 
    C string literals were added in Rust 1.77, which produce '&CStr's
    (the 'core' one), so now we can write:
 
        c"hi"
 
    instead of:
 
        c_str!("hi")
 
  - Add 'num' module for numerical features.
 
    It includes the 'Integer' trait, implemented for all primitive
    integer types.
 
    It also includes the 'Bounded' integer wrapping type: an integer
    value that requires only the 'N' less significant bits of the wrapped
    type to be encoded:
 
        // An unsigned 8-bit integer, of which only the 4 LSBs are used.
        let v = Bounded::<u8, 4>:🆕:<15>();
        assert_eq!(v.get(), 15);
 
    'Bounded' is useful to e.g. enforce guarantees when working with
    bitfields that have an arbitrary number of bits.
 
    Values can be constructed from simple non-constant expressions or,
    for more complex ones, validated at runtime.
 
    'Bounded' also comes with comparison and arithmetic operations (with
    both their backing type and other 'Bounded's with a compatible
    backing type), casts to change the backing type, extending/shrinking
    and infallible/fallible conversions from/to primitives as applicable.
 
  - 'rbtree' module: add immutable cursor ('Cursor').
 
    It enables to use just an immutable tree reference where appropriate.
    The existing fully-featured mutable cursor is renamed to 'CursorMut'.
 
 kallsyms:
 
  - Fix wrong "big" kernel symbol type read from procfs.
 
 'pin-init' crate:
 
  - A couple minor fixes (Benno asked me to pick these patches up for
    him this cycle).
 
 Documentation:
 
  - Quick Start guide: add Debian 13 (Trixie).
 
    Debian Stable is now able to build Linux, since Debian 13 (released
    2025-08-09) packages Rust 1.85.0, which is recent enough.
 
    We are planning to propose that the minimum supported Rust version in
    Linux follows Debian Stable releases, with Debian 13 being the first
    one we upgrade to, i.e. Rust 1.85.
 
 MAINTAINERS:
 
  - Add entry for the new 'num' module.
 
  - Remove Alex as Rust maintainer: he hasn't had the time to contribute
    for a few years now, so it is a no-op change in practice.
 
 And a few other cleanups and improvements.
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Merge tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Add support for 'syn'.

     Syn is a parsing library for parsing a stream of Rust tokens into a
     syntax tree of Rust source code.

     Currently this library is geared toward use in Rust procedural
     macros, but contains some APIs that may be useful more generally.

     'syn' allows us to greatly simplify writing complex macros such as
     'pin-init' (Benno has already prepared the 'syn'-based version). We
     will use it in the 'macros' crate too.

     'syn' is the most downloaded Rust crate (according to crates.io),
     and it is also used by the Rust compiler itself. While the amount
     of code is substantial, there should not be many updates needed for
     these crates, and even if there are, they should not be too big,
     e.g. +7k -3k lines across the 3 crates in the last year.

     'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
     I only modified their code to remove a third dependency
     ('unicode-ident') and to add the SPDX identifiers. The code can be
     easily verified to exactly match upstream with the provided
     scripts.

     They are all licensed under "Apache-2.0 OR MIT", like the other
     vendored 'alloc' crate we had for a while.

     Please see the merge commit with the cover letter for more context.

   - Allow 'unreachable_pub' and 'clippy::disallowed_names' for
     doctests.

     Examples (i.e. doctests) may want to do things like show public
     items and use names such as 'foo'.

     Nevertheless, we still try to keep examples as close to real code
     as possible (this is part of why running Clippy on doctests is
     important for us, e.g. for safety comments, which userspace Rust
     does not support yet but we are stricter).

  'kernel' crate:

   - Replace our custom 'CStr' type with 'core::ffi::CStr'.

     Using the standard library type reduces our custom code footprint,
     and we retain needed custom functionality through an extension
     trait and a new 'fmt!' macro which replaces the previous 'core'
     import.

     This started in 6.17 and continued in 6.18, and we finally land the
     replacement now. This required quite some stamina from Tamir, who
     split the changes in steps to prepare for the flag day change here.

   - Replace 'kernel::c_str!' with C string literals.

     C string literals were added in Rust 1.77, which produce '&CStr's
     (the 'core' one), so now we can write:

         c"hi"

     instead of:

         c_str!("hi")

   - Add 'num' module for numerical features.

     It includes the 'Integer' trait, implemented for all primitive
     integer types.

     It also includes the 'Bounded' integer wrapping type: an integer
     value that requires only the 'N' least significant bits of the
     wrapped type to be encoded:

         // An unsigned 8-bit integer, of which only the 4 LSBs are used.
         let v = Bounded::<u8, 4>:🆕:<15>();
         assert_eq!(v.get(), 15);

     'Bounded' is useful to e.g. enforce guarantees when working with
     bitfields that have an arbitrary number of bits.

     Values can also be constructed from simple non-constant expressions
     or, for more complex ones, validated at runtime.

     'Bounded' also comes with comparison and arithmetic operations
     (with both their backing type and other 'Bounded's with a
     compatible backing type), casts to change the backing type,
     extending/shrinking and infallible/fallible conversions from/to
     primitives as applicable.

   - 'rbtree' module: add immutable cursor ('Cursor').

     It enables to use just an immutable tree reference where
     appropriate. The existing fully-featured mutable cursor is renamed
     to 'CursorMut'.

  kallsyms:

   - Fix wrong "big" kernel symbol type read from procfs.

  'pin-init' crate:

   - A couple minor fixes (Benno asked me to pick these patches up for
     him this cycle).

  Documentation:

   - Quick Start guide: add Debian 13 (Trixie).

     Debian Stable is now able to build Linux, since Debian 13 (released
     2025-08-09) packages Rust 1.85.0, which is recent enough.

     We are planning to propose that the minimum supported Rust version
     in Linux follows Debian Stable releases, with Debian 13 being the
     first one we upgrade to, i.e. Rust 1.85.

  MAINTAINERS:

   - Add entry for the new 'num' module.

   - Remove Alex as Rust maintainer: he hasn't had the time to
     contribute for a few years now, so it is a no-op change in
     practice.

  And a few other cleanups and improvements"

* tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
  rust: macros: support `proc-macro2`, `quote` and `syn`
  rust: syn: enable support in kbuild
  rust: syn: add `README.md`
  rust: syn: remove `unicode-ident` dependency
  rust: syn: add SPDX License Identifiers
  rust: syn: import crate
  rust: quote: enable support in kbuild
  rust: quote: add `README.md`
  rust: quote: add SPDX License Identifiers
  rust: quote: import crate
  rust: proc-macro2: enable support in kbuild
  rust: proc-macro2: add `README.md`
  rust: proc-macro2: remove `unicode_ident` dependency
  rust: proc-macro2: add SPDX License Identifiers
  rust: proc-macro2: import crate
  rust: kbuild: support using libraries in `rustc_procmacro`
  rust: kbuild: support skipping flags in `rustc_test_library`
  rust: kbuild: add proc macro library support
  rust: kbuild: simplify `--cfg` handling
  rust: kbuild: introduce `core-flags` and `core-skip_flags`
  ...
2025-12-03 14:16:49 -08:00
Boqun Feng f74cf399e0 rust: debugfs: Replace the usage of Rust native atomics
Rust native atomics are not allowed to use in kernel due to the mismatch
of memory model with Linux kernel memory model, hence remove the usage
of Rust native atomics in debufs.

Reviewed-by: Matthew Maurer <mmaurer@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Tested-by: David Gow <davidgow@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251022035324.70785-4-boqun.feng@gmail.com
2025-11-12 08:56:42 -08:00
Danilo Krummrich f656279afd samples: rust: debugfs_scoped: add example for blobs
Extend the rust_debugfs_scoped sample to demonstrate how to export a
large binary object through a ScopedDir.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 00:35:40 +01:00
Miguel Ojeda 7b0c32cbed samples: rust: debugfs: use `core::ffi::CStr` method names
Prepare for `core::ffi::CStr` taking the place of `kernel::str::CStr` by
avoiding methods that only exist on the latter.

This backslid in commit d4a5d397c7 ("samples: rust: Add scoped debugfs
sample driver").

Link: https://patch.msgid.link/20251019213049.2060970-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-20 04:04:23 +02:00
Matthew Maurer d4a5d397c7 samples: rust: Add scoped debugfs sample driver
Adds a new sample driver `rust_scoped_debugfs` that demonstrates the
use of the scoped debugfs APIs.

The driver creates a `control` directory with two write-only files,
`create` and `remove`. Writing a name and a series of numbers to
`create` will create a new subdirectory under a `dynamic` directory.
This new subdirectory will contain files that expose the numbers as
atomic values.

Writing a name to `remove` will remove the corresponding subdirectory
from the `dynamic` directory.

This sample serves as an example of how to use the `debugfs::Scope`
and `debugfs::ScopedDir` APIs to create and manage debugfs entries
that are tied to the lifetime of a data structure.

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-v11-7-7d12a165685a@google.com
[ Rename "scoped_debugfs" -> "debugfs_scoped", fix up
  Result<(), Error> -> Result. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-09-10 21:05:11 +02:00