Commit Graph

1101 Commits

Author SHA1 Message Date
Miguel Ojeda
a762f883ec rust: i2c: prepare for core::ffi::CStr
The rust-next tree contains commit:

    3b83f5d5e7 ("rust: replace `CStr` with `core::ffi::CStr`")

which, when merged together with commits:

    57c5bd9aee ("rust: i2c: add basic I2C device and driver abstractions")
    f3cc26a417 ("rust: i2c: add manual I2C device creation abstractions")

from this tree (driver-core), produces errors like the following:

    error[E0599]: no method named `len_with_nul` found for reference `&'static ffi::CStr` in the current scope
      --> rust/kernel/i2c.rs:48:16
       |
    48 |             id.len_with_nul() <= Self::I2C_NAME_SIZE,
       |                ^^^^^^^^^^^^ method not found in `&CStr`

    error[E0599]: no method named `as_bytes_with_nul` found for reference `&'static ffi::CStr` in the current scope
      --> rust/kernel/i2c.rs:51:22
       |
    51 |         let src = id.as_bytes_with_nul();
       |                      ^^^^^^^^^^^^^^^^^
       |
    help: there is a method `to_bytes_with_nul` with a similar name
       |
    51 |         let src = id.to_bytes_with_nul();
       |                      ~~~~~~~~~~~~~~~~~

which were detected in linux-next by Stephen [1].

The `i2c` code can be independently prepared to be ready for the change,
thus do so.

The change is similar to the one done by Tamir in commit 657403637f
("rust: acpi: use `core::ffi::CStr` method names").

Link: https://lore.kernel.org/all/20251120181111.65ce75a0@canb.auug.org.au/ [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20251123163536.1771801-1-ojeda@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-24 09:14:47 +13:00
Markus Probst
e4addc7cc2 rust: Add trait to convert a device reference to a bus device reference
Implement the `AsBusDevice` trait for converting a `Device` reference to a
bus device reference for all bus devices.

The `AsBusDevice` trait allows abstractions to provide the bus device in
class device callbacks. It must not be used by drivers and is intended for
bus and class device abstractions only.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
Link: https://patch.msgid.link/20251027200547.1038967-2-markus.probst@posteo.de
[ * Remove unused import.
  * Change visibility of AsBusDevice to public.
  * Fix build for USB.
  * Add impl for I2cClient.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18 11:00:51 +13:00
Igor Korotin
f3cc26a417 rust: i2c: add manual I2C device creation abstractions
In addition to the basic I2C device support, add rust abstractions
upon `i2c_new_client_device`/`i2c_unregister_device` C functions.

Implement the core abstractions needed for manual creation/deletion
of I2C devices, including:

 * `i2c::Registration` — a NonNull pointer created by the function
                          `i2c_new_client_device`

 * `i2c::I2cAdapter` — a ref counted wrapper around `struct i2c_adapter`

 * `i2c::I2cBoardInfo` — a safe wrapper around `struct i2c_board_info`

Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162154.171493-1-igor.korotin.linux@gmail.com
[ Remove unnecessary safety comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18 10:28:19 +13:00
Igor Korotin
57c5bd9aee rust: i2c: add basic I2C device and driver abstractions
Implement the core abstractions needed for I2C drivers, including:

* `i2c::Driver` — the trait drivers must implement, including `probe`

* `i2c::I2cClient` — a safe wrapper around `struct i2c_client`

* `i2c::Adapter` — implements `driver::RegistrationOps` to hook into the
  generic `driver::Registration` machinery

* `i2c::DeviceId` — a `RawDeviceIdIndex` implementation for I2C device IDs

Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162144.171469-1-igor.korotin.linux@gmail.com
[ Remove unnecessary safety comment; fix rustdoc `Device` -> `I2cClient`.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18 10:26:42 +13:00
Alice Ryhl
dd6ff5cf56 rust: io: add typedef for phys_addr_t
The C typedef phys_addr_t is missing an analogue in Rust, meaning that
we end up using bindings::phys_addr_t or ResourceSize as a replacement
in various places throughout the kernel. Fix that by introducing a new
typedef on the Rust side. Place it next to the existing ResourceSize
typedef since they're quite related to each other.

Cc: stable@vger.kernel.org # for v6.18 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-4-538307384f82@google.com
Link: https://lore.kernel.org/all/20251112-resource-phys-typedefs-v2-0-538307384f82@google.com/ [1]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-13 20:17:24 +11:00
Alice Ryhl
ee2776e54b rust: scatterlist: import ResourceSize from kernel::io
Now that ResourceSize has been moved to kernel::io, import it from the
io module instead of the io::resource sub-module. It makes sense in this
case since the dma_len isn't really related to the Resource type even
though both are sizes of allocations in physical ram.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-3-538307384f82@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-13 20:17:24 +11:00
Alice Ryhl
dfd6799304 rust: io: move ResourceSize to top-level io module
Resource sizes are a general concept for dealing with physical
addresses, and not specific to the Resource type, which is just one way
to access physical addresses. Thus, move the typedef to the io module.

Still keep a re-export under resource. This avoids this commit from
being a flag-day, but I also think it's a useful re-export in general so
that you can import

	use kernel::io::resource::{Resource, ResourceSize};

instead of having to write

	use kernel::io::{
	    resource::Resource,
	    ResourceSize,
	};

in the specific cases where you need ResourceSize because you are using
the Resource type. Therefore I think it makes sense to keep this
re-export indefinitely and it is *not* intended as a temporary re-export
for migration purposes.

Cc: stable@vger.kernel.org # for v6.18 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-2-538307384f82@google.com
Link: https://lore.kernel.org/all/20251112-resource-phys-typedefs-v2-0-538307384f82@google.com/ [1]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-13 20:16:51 +11:00
Alice Ryhl
919b729227 rust: io: define ResourceSize as resource_size_t
These typedefs are always equivalent so this should not change anything,
but the code makes a lot more sense like this.

Cc: stable@vger.kernel.org
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Fixes: 493fc33ec2 ("rust: io: add resource abstraction")
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-1-538307384f82@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-13 19:58:24 +11:00
Danilo Krummrich
ededb7bcdf rust: dma: use NonNull<T> instead of *mut T
In struct CoherentAllocation, use NonNull<T> instead of a raw *mut T for
the CPU address; the CPU address of a valid CoherentAllocation won't
ever be NULL.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103190655.2326191-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-11 19:45:23 +11:00
Danilo Krummrich
f7afdc4737 rust: dma: make use of start_ptr() and start_ptr_mut()
Using start_ptr() and start_ptr_mut() has the advantage that we inherit
the requirements the a mutable or immutable reference from those
methods.

Hence, use them instead of self.cpu_addr.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103190655.2326191-1-dakr@kernel.org
[ Keep using self.cpu_addr in item_from_index(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-11 19:45:23 +11:00
Danilo Krummrich
d8407396f1 rust: pci: use "kernel vertical" style for imports
Convert all imports in the PCI 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
Reviewed-by: Zhi Wang <zhiw@nvidia.com>
Link: https://patch.msgid.link/20251105120352.77603-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-11 19:45:23 +11:00
Danilo Krummrich
9d39842f6a rust: io: cleanup imports and use "kernel vertical" style
Commit 46f045db5a ("rust: Add read_poll_timeout_atomic function")
initiated the first import change in the I/O module using the agreed
"kernel vertical" import style [1].

For consistency throughout the module, adjust all other imports
accordingly.

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

Link: https://docs.kernel.org/rust/coding-guidelines.html#imports [1]
Reviewed-by: Zhi Wang <zhiw@nvidia.com>
Link: https://patch.msgid.link/20251104133301.59402-1-dakr@kernel.org
[ Use prelude::* in io/poll.rs. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-11 19:43:39 +11:00
Danilo Krummrich
0bc605713f rust: debugfs: Implement BinaryReader for Mutex<T> only when T is Unpin
Commit da123f0ee4 ("rust: lock: guard: Add T: Unpin bound to
DerefMut") from tip/master adds an Unpin bound to T for Mutex<T>, hence
also restrict the implementation of BinaryReader for Mutex<T>
accordingly.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20251107134144.117905bd@canb.auug.org.au/
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251107091612.2557480-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-07 22:53:11 +01:00
Danilo Krummrich
b892ed360d rust: platform: get rid of redundant Result in IRQ methods
Currently request_irq_by_index() returns

        Result<impl PinInit<irq::Registration<T>, Error> + 'a>

which may carry an error in the Result or the initializer; the same is
true for the other IRQ methods.

Use pin_init::pin_init_scope() to get rid of this redundancy.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103203053.2348783-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-06 10:19:36 +01:00
Danilo Krummrich
1f7b01661f rust: pci: get rid of redundant Result in IRQ methods
Currently request_irq() returns

	Result<impl PinInit<irq::Registration<T>, Error> + 'a>

which may carry an error in the Result or the initializer; the same is
true for request_threaded_irq().

Use pin_init::pin_init_scope() to get rid of this redundancy.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103203053.2348783-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-06 10:19:36 +01:00
Danilo Krummrich
1bf5b90cd2 rust: auxiliary: fix false positive warning for missing a safety comment
Some older (yet supported) versions of clippy throw a false positive
warning for missing a safety comment when the safety comment is on a
multiline statement.

warning: unsafe block missing a safety comment
   --> rust/kernel/auxiliary.rs:351:22
    |
351 |                 Self(unsafe { NonNull::new_unchecked(adev) }),
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider adding a safety comment on the preceding line
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
    = note: requested on the command line with `-W clippy::undocumented-unsafe-blocks`

warning: 1 warning emitted

Fix this by placing the safety comment right on top of the same line
introducing the unsafe block.

Fixes: e4e679c860 ("rust: auxiliary: unregister on parent device unbind")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20251103203932.2361660-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 01:26:51 +01:00
Danilo Krummrich
35bd14d929 rust: debugfs: support binary large objects for ScopedDir
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>
2025-11-05 00:35:40 +01:00
Danilo Krummrich
a9fca8a7b2 rust: debugfs: support blobs from smart pointers
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>
2025-11-05 00:35:40 +01:00
Danilo Krummrich
9c804d9cf2 rust: debugfs: support for binary large objects
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>
2025-11-05 00:35:40 +01:00
Danilo Krummrich
0ddceba270 rust: uaccess: add UserSliceWriter::write_slice_file()
Add UserSliceWriter::write_slice_file(), which is the same as
UserSliceWriter::write_slice_partial() but updates the given
file::Offset by the number of bytes written.

This is equivalent to C's `simple_read_from_buffer()` and useful when
dealing with file offsets from file operations.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace saturating_add() with the raw operator and a corresponding
  OVERFLOW comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 00:35:37 +01:00
Danilo Krummrich
8615053347 rust: uaccess: add UserSliceWriter::write_slice_partial()
The existing write_slice() method is a wrapper around copy_to_user() and
expects the user buffer to be larger than the source buffer.

However, userspace may split up reads in multiple partial operations
providing an offset into the source buffer and a smaller user buffer.

In order to support this common case, provide a helper for partial
writes.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace map_or() with let-else; use saturating_add(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 00:35:27 +01:00
Danilo Krummrich
5829e33048 rust: uaccess: add UserSliceReader::read_slice_file()
Add UserSliceReader::read_slice_file(), which is the same as
UserSliceReader::read_slice_partial() but updates the given file::Offset
by the number of bytes read.

This is equivalent to C's `simple_write_to_buffer()` and useful when
dealing with file offsets from file operations.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace saturating_add() with the raw operator and a corresponding
  OVERFLOW comment. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 00:35:25 +01:00
Danilo Krummrich
f2af7b01b0 rust: uaccess: add UserSliceReader::read_slice_partial()
The existing read_slice() method is a wrapper around copy_from_user()
and expects the user buffer to be larger than the destination buffer.

However, userspace may split up writes in multiple partial operations
providing an offset into the destination buffer and a smaller user
buffer.

In order to support this common case, provide a helper for partial
reads.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
[ Replace map_or() with let-else; use saturating_add(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 00:35:20 +01:00
Danilo Krummrich
db7bd1affa rust: fs: add file::Offset type alias
Add a type alias for file offsets, i.e. bindings::loff_t. Trying to
avoid using raw bindings types, this seems to be the better alternative
compared to just using i64.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://patch.msgid.link/20251020222722.240473-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-05 00:05:38 +01:00
FUJITA Tomonori
46f045db5a rust: Add read_poll_timeout_atomic function
Add read_poll_timeout_atomic function which polls periodically until a
condition is met, an error occurs, or the attempt limit is reached.

The C's read_poll_timeout_atomic() is used for the similar purpose.
In atomic context the timekeeping infrastructure is unavailable, so
reliable time-based timeouts cannot be implemented. So instead, the
helper accepts a maximum number of attempts and busy-waits (udelay +
cpu_relax) between tries.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://patch.msgid.link/20251103112958.2961517-3-fujita.tomonori@gmail.com
[ Adjust imports to use "kernel vertical" style. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-04 14:06:47 +01:00
FUJITA Tomonori
ad68b55a9e rust: add udelay() function
Add udelay() function, inserts a delay based on microseconds with busy
waiting, in preparation for supporting read_poll_timeout_atomic().

Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://patch.msgid.link/20251103112958.2961517-2-fujita.tomonori@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-04 13:25:29 +01:00
Danilo Krummrich
fde40a558d rust: usb: fix broken call to T::disconnect()
A refactoring of Device::drvdata_obtain() broke T::disconnect() in the
USB abstractions.

"""
error[E0599]: no method named `data` found for struct `core::pin::Pin<kbox::Box<T, Kmalloc>>` in the current scope
  --> rust/kernel/usb.rs:92:34
   |
92 |         T::disconnect(intf, data.data());
   |                                  ^^^^ method not found in `core::pin::Pin<kbox::Box<T, Kmalloc>>`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0599`.
make[2]: *** [rust/Makefile:553: rust/kernel.o] Error 1
make[1]: *** [/builddir/build/BUILD/kernel-6.18.0-build/kernel-next-20251103/linux-6.18.0-0.0.next.20251103.436.vanilla.fc44.x86_64/Makefile:1316: prepare] Error 2
make: *** [Makefile:256: __sub-make] Error 2
"""

This slipped through, since the USB abstractions are globally disabled.
However, the USB tree recently enabled them, hence it showed up in
linux-next.

Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/all/1c8afbc0-e888-4702-9e4e-fa8aef0f97ae@leemhuis.info/
Fixes: 6bbaa93912 ("rust: device: narrow the generic of drvdata_obtain()")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://patch.msgid.link/20251103110115.1925072-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-04 00:31:25 +01:00
Danilo Krummrich
675e514edd rust: auxiliary: implement parent() for Device<Bound>
Take advantage of the fact that if the auxiliary device is bound the
parent is guaranteed to be bound as well and implement a separate
parent() method for auxiliary::Device<Bound>.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 18:29:32 +01:00
Danilo Krummrich
b69165a097 rust: auxiliary: move parent() to impl Device
Currently, the parent method is implemented for any Device<Ctx>, i.e.
any device context and returns a &device::Device<Normal>.

However, a subsequent patch will introduce

	impl Device<Bound> {
	    pub fn parent() -> device::Device<Bound> { ... }
	}

which takes advantage of the fact that if the auxiliary device is bound
the parent is guaranteed to be bound as well.

I.e. the behavior we want is that all device contexts that dereference
to Bound, will use the implementation above, whereas the old
implementation should only be implemented for Device<Normal>.

Hence, move the current implementation.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 18:29:32 +01:00
Danilo Krummrich
e4e679c860 rust: auxiliary: unregister on parent device unbind
Guarantee that an auxiliary driver will be unbound before its parent is
unbound; there is no point in operating an auxiliary device whose parent
has been unbound.

In practice, this guarantee allows us to assume that for a bound
auxiliary device, also the parent device is bound.

This is useful when an auxiliary driver calls into its parent, since it
allows the parent to directly access device resources and its device
private data due to the guaranteed bound device context.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 18:29:32 +01:00
Danilo Krummrich
589b061975 rust: auxiliary: consider auxiliary devices always have a parent
An auxiliary device is guaranteed to always have a parent device (both
in C and Rust), hence don't return an Option<&auxiliary::Device> in
auxiliary::Device::parent().

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 18:29:32 +01:00
Danilo Krummrich
6f61a2637a rust: device: introduce Device::drvdata()
In C dev_get_drvdata() has specific requirements under which it is valid
to access the returned pointer. That is, drivers have to ensure that

  (1) for the duration the returned pointer is accessed the driver is
      bound and remains to be bound to the corresponding device,

  (2) the returned void * is treated according to the driver's private
      data type, i.e. according to what has been passed to
      dev_set_drvdata().

In Rust, (1) can be ensured by simply requiring the Bound device
context, i.e. provide the drvdata() method for Device<Bound> only.

For (2) we would usually make the device type generic over the driver
type, e.g. Device<T: Driver>, where <T as Driver>::Data is the type of
the driver's private data.

However, a device does not have a driver type known at compile time and
may be bound to multiple drivers throughout its lifetime.

Hence, in order to be able to provide a safe accessor for the driver's
device private data, we have to do the type check on runtime.

This is achieved by letting a driver assert the expected type, which is
then compared to a type hash stored in struct device_private when
dev_set_drvdata() is called.

Example:

	// `dev` is a `&Device<Bound>`.
	let data = dev.drvdata::<SampleDriver>()?;

There are two aspects to note:

  (1) Technically, the same check could be achieved by comparing the
      struct device_driver pointer of struct device with the struct
      device_driver pointer of the driver struct (e.g. struct
      pci_driver).

      However, this would - in addition the pointer comparison - require
      to tie back the private driver data type to the struct
      device_driver pointer of the driver struct to prove correctness.

      Besides that, accessing the driver struct (stored in the module
      structure) isn't trivial and would result into horrible code and
      API ergonomics.

  (2) Having a direct accessor to the driver's private data is not
      commonly required (at least in Rust): Bus callback methods already
      provide access to the driver's device private data through a &self
      argument, while other driver entry points such as IRQs,
      workqueues, timers, IOCTLs, etc. have their own private data with
      separate ownership and lifetime.

      In other words, a driver's device private data is only relevant
      for driver model contexts (such a file private is only relevant
      for file contexts).

Having that said, the motivation for accessing the driver's device
private data with Device<Bound>::drvdata() are interactions between
drivers. For instance, when an auxiliary driver calls back into its
parent, the parent has to be capable to derive its private data from the
corresponding device (i.e. the parent of the auxiliary device).

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ * Remove unnecessary `const _: ()` block,
  * rename type_id_{store,match}() to {set,match}_type_id(),
  * assert size_of::<bindings::driver_type>() >= size_of::<TypeId>(),
  * add missing check in case Device::drvdata() is called from probe().

  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 18:18:02 +01:00
Danilo Krummrich
6bbaa93912 rust: device: narrow the generic of drvdata_obtain()
Let T be the actual private driver data type without the surrounding
box, as it leaves less room for potential bugs.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-29 16:40:28 +01:00
Greg Kroah-Hartman
37022410f4 Merge 6.18-rc3 into driver-core-next
We need the driver core fixes in here as well to build on top of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-27 08:02:50 +01:00
FUJITA Tomonori
aad1577ab9 rust: simplify read_poll_timeout's example code
- Drop unnecessary Result's '<()>'
- Use '?' instead of match

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-26 17:56:14 +01:00
Linus Torvalds
72761a7e31 Merge tag 'driver-core-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core fixes from Danilo Krummrich:

 - In Device::parent(), do not make any assumptions on the device
   context of the parent device

 - Check visibility before changing ownership of a sysfs attribute
   group

 - In topology_parse_cpu_capacity(), replace an incorrect usage of
   PTR_ERR_OR_ZERO() with IS_ERR_OR_NULL()

 - In devcoredump, fix a circular locking dependency between
   struct devcd_entry::mutex and kernfs

 - Do not warn about a pending fw_devlink sync state

* tag 'driver-core-6.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  arch_topology: Fix incorrect error check in topology_parse_cpu_capacity()
  rust: device: fix device context of Device::parent()
  sysfs: check visibility before changing group attribute ownership
  devcoredump: Fix circular locking dependency with devcd->mutex.
  driver core: fw_devlink: Don't warn about sync_state() pending
2025-10-25 11:03:46 -07:00
Peter Colberg
26c1a20bf7 rust: pci: normalise spelling of PCI BAR
Consistently refer to PCI base address register as PCI BAR.
Fix spelling mistake "Mapps" -> "Maps".

Link: https://lore.kernel.org/rust-for-linux/20251015225827.GA960157@bhelgaas/
Link: https://github.com/Rust-for-Linux/linux/issues/1196
Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Peter Colberg <pcolberg@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-23 20:12:32 +02:00
Peter Colberg
c7f6d5380f rust: pci: refer to legacy as INTx interrupts
Consistently use INTx, as in the description of IrqType::Intx, to refer
to the four legacy PCI interrupts, INTA#, INTB#, INTC#, and INTD#.

Link: https://lore.kernel.org/rust-for-linux/20251015230209.GA960343@bhelgaas/
Link: https://github.com/Rust-for-Linux/linux/issues/1196
Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Peter Colberg <pcolberg@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-23 20:12:32 +02:00
Danilo Krummrich
0242623384 rust: driver: let probe() return impl PinInit<Self, Error>
The driver model defines the lifetime of the private data stored in (and
owned by) a bus device to be valid from when the driver is bound to a
device (i.e. from successful probe()) until the driver is unbound from
the device.

This is already taken care of by the Rust implementation of the driver
model. However, we still ask drivers to return a Result<Pin<KBox<Self>>>
from probe().

Unlike in C, where we do not have the concept of initializers, but
rather deal with uninitialized memory, drivers can just return an
impl PinInit<Self, Error> instead.

This contributes to more clarity to the fact that a driver returns it's
device private data in probe() and the Rust driver model owns the data,
manages the lifetime and - considering the lifetime - provides (safe)
accessors for the driver.

Hence, let probe() functions return an impl PinInit<Self, Error> instead
of Result<Pin<KBox<Self>>>.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-21 18:40:48 +02:00
Danilo Krummrich
e6901808a3 rust: pci: move IRQ infrastructure to separate file
Move the PCI interrupt infrastructure to a separate sub-module in order
to keep things organized.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-20 12:03:23 +02:00
Danilo Krummrich
3c2e31d717 rust: pci: move I/O infrastructure to separate file
Move the PCI I/O infrastructure to a separate sub-module in order to
keep things organized.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-20 12:03:23 +02:00
Danilo Krummrich
651692d32c rust: pci: implement TryInto<IrqRequest<'a>> for IrqVector<'a>
Implement TryInto<IrqRequest<'a>> for IrqVector<'a> to directly convert
a pci::IrqVector into a generic IrqRequest, instead of taking the
indirection via an unrelated pci::Device method.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-20 12:03:23 +02:00
Danilo Krummrich
cfec502b3d rust: device: fix device context of Device::parent()
Regardless of the DeviceContext of a device, we can't give any
guarantees about the DeviceContext of its parent device.

This is very subtle, since it's only caused by a simple typo, i.e.

	 Self::from_raw(parent)

which preserves the DeviceContext in this case, vs.

	 Device::from_raw(parent)

which discards the DeviceContext.

(I should have noticed it doing the correct thing in auxiliary::Device
subsequently, but somehow missed it.)

Hence, fix both Device::parent() and auxiliary::Device::parent().

Cc: stable@vger.kernel.org
Fixes: a4c9f71e34 ("rust: device: implement Device::parent()")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-17 23:24:19 +02:00
Miguel Ojeda
1f1d3e1d09 rust: bitmap: fix formatting
We do our best to keep the repository `rustfmt`-clean, thus run the tool
to fix the formatting issue.

Link: https://docs.kernel.org/rust/coding-guidelines.html#style-formatting
Link: https://rust-for-linux.com/contributing#submit-checklist-addendum
Fixes: 0f5878834d ("rust: bitmap: clean Rust 1.92.0 `unused_unsafe` warning")
Reviewed-by: Burak Emir <bqe@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-17 13:02:22 +02:00
Miguel Ojeda
32f072d9ea rust: cpufreq: fix formatting
We do our best to keep the repository `rustfmt`-clean, thus run the tool
to fix the formatting issue.

Link: https://docs.kernel.org/rust/coding-guidelines.html#style-formatting
Link: https://rust-for-linux.com/contributing#submit-checklist-addendum
Fixes: f97aef092e ("cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency")
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-17 00:56:20 +02:00
Miguel Ojeda
8a7c601e14 rust: alloc: employ a trailing comment to keep vertical layout
Apply the formatting guidelines introduced in the previous commit to
make the file `rustfmt`-clean again.

Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-10-17 00:56:20 +02:00
Linus Torvalds
7ea30958b3 Merge tag 'vfs-6.18-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:

 - Handle inode number mismatches in nsfs file handles

 - Update the comment to init_file()

 - Add documentation link for EBADF in the rust file code

 - Skip read lock assertion for read-only filesystems when using dax

 - Don't leak disconnected dentries during umount

 - Fix new coredump input pattern validation

 - Handle ENOIOCTLCMD conversion in vfs_fileattr_{g,s}et() correctly

 - Remove redundant IOCB_DIO_CALLER_COMP clearing in overlayfs

* tag 'vfs-6.18-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  ovl: remove redundant IOCB_DIO_CALLER_COMP clearing
  fs: return EOPNOTSUPP from file_setattr/file_getattr syscalls
  Revert "fs: make vfs_fileattr_[get|set] return -EOPNOTSUPP"
  coredump: fix core_pattern input validation
  vfs: Don't leak disconnected dentries on umount
  dax: skip read lock assertion for read-only filesystems
  rust: file: add intra-doc link for 'EBADF'
  fs: update comment in init_file()
  nsfs: handle inode number mismatches gracefully in file handles
2025-10-15 15:12:58 -07:00
Miguel Ojeda
0f5878834d rust: bitmap: clean Rust 1.92.0 unused_unsafe warning
Starting with Rust 1.92.0 (expected 2025-12-11), Rust allows to safely
take the address of a union field [1][2]:

      CLIPPY L rust/kernel.o
    error: unnecessary `unsafe` block
       --> rust/kernel/bitmap.rs:169:13
        |
    169 |             unsafe { core::ptr::addr_of!(self.repr.bitmap) }
        |             ^^^^^^ unnecessary `unsafe` block
        |
        = note: `-D unused-unsafe` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(unused_unsafe)]`

    error: unnecessary `unsafe` block
       --> rust/kernel/bitmap.rs:185:13
        |
    185 |             unsafe { core::ptr::addr_of_mut!(self.repr.bitmap) }
        |             ^^^^^^ unnecessary `unsafe` block

Thus allow both instances to clean the warning in newer compilers.

Link: https://github.com/rust-lang/rust/issues/141264 [1]
Link: https://github.com/rust-lang/rust/pull/141469 [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
2025-10-15 10:39:54 -04:00
Joel Fernandes
340ccc9735 rust: pci: Allocate and manage PCI interrupt vectors
Add support to PCI rust module to allocate, free and manage IRQ vectors.
Integrate with devres for managing the allocated resources.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
[ Add links in doc-comments; add missing invariant comment; re-format
  multiple safety requirements as list and fix missing backticks;
  refactor the example of alloc_irq_vectors() to compile. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-15 14:19:53 +02:00
Linus Torvalds
abdf766d14 Merge tag 'pm-6.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
 "These are cpufreq fixes and cleanups on top of the material merged
  previously, a power management core code fix and updates of the
  runtime PM framework including unit tests, documentation updates and
  introduction of auto-cleanup macros for runtime PM "resume and get"
  and "get without resuming" operations.

  Specifics:

   - Make cpufreq drivers setting the default CPU transition latency to
     CPUFREQ_ETERNAL specify a proper default transition latency value
     instead which addresses a regression introduced during the 6.6
     cycle that broke CPUFREQ_ETERNAL handling (Rafael Wysocki)

   - Make the cpufreq CPPC driver use a proper transition delay value
     when CPUFREQ_ETERNAL is returned by cppc_get_transition_latency()
     to indicate an error condition (Rafael Wysocki)

   - Make cppc_get_transition_latency() return a negative error code to
     indicate error conditions instead of using CPUFREQ_ETERNAL for this
     purpose and drop CPUFREQ_ETERNAL that has no other users (Rafael
     Wysocki, Gopi Krishna Menon)

   - Fix device leak in the mediatek cpufreq driver (Johan Hovold)

   - Set target frequency on all CPUs sharing a policy during frequency
     updates in the tegra186 cpufreq driver and make it initialize all
     cores to max frequencies (Aaron Kling)

   - Rust cpufreq helper cleanup (Thorsten Blum)

   - Make pm_runtime_put*() family of functions return 1 when the given
     device is already suspended which is consistent with the
     documentation (Brian Norris)

   - Add basic kunit tests for runtime PM API contracts and update
     return values in kerneldoc comments for the runtime PM API (Brian
     Norris, Dan Carpenter)

   - Add auto-cleanup macros for runtime PM "resume and get" and "get
     without resume" operations, use one of them in the PCI core and
     drop the existing "free" macro introduced for similar purpose, but
     somewhat cumbersome to use (Rafael Wysocki)

   - Make the core power management code avoid waiting on device links
     marked as SYNC_STATE_ONLY which is consistent with the handling of
     those device links elsewhere (Pin-yen Lin)"

* tag 'pm-6.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  docs/zh_CN: Fix malformed table
  docs/zh_TW: Fix malformed table
  PM: runtime: Fix error checking for kunit_device_register()
  PM: runtime: Introduce one more usage counter guard
  cpufreq: Drop unused symbol CPUFREQ_ETERNAL
  ACPI: CPPC: Do not use CPUFREQ_ETERNAL as an error value
  cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay
  cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency
  PM: runtime: Drop DEFINE_FREE() for pm_runtime_put()
  PCI/sysfs: Use runtime PM guard macro for auto-cleanup
  PM: runtime: Add auto-cleanup macros for "resume and get" operations
  cpufreq: tegra186: Initialize all cores to max frequencies
  cpufreq: tegra186: Set target frequency for all cpus in policy
  rust: cpufreq: streamline find_supply_names
  cpufreq: mediatek: fix device leak on probe failure
  PM: sleep: Do not wait on SYNC_STATE_ONLY device links
  PM: runtime: Update kerneldoc return codes
  PM: runtime: Make put{,_sync}() return 1 when already suspended
  PM: runtime: Add basic kunit tests for API contracts
2025-10-07 09:39:51 -07:00