9 Commits
Author SHA1 Message Date
Danilo Krummrich 893f39dada rust: faux: add Device type with AsBusDevice support
Add a faux::Device type that wraps struct faux_device and implements
AsBusDevice, enabling faux devices to be used as parent devices for
subsystems that require a bus device, such as DRM.

Update Registration to return &faux::Device<Bound> via AsRef.

Reviewed-by: Alexandre Courbot <[email protected]>
Tested-by: Deborah Brouwer <[email protected]>
Link: https://patch.msgid.link/[email protected]
[ Drop redundant 'struct device' invariant; implied by valid
  struct faux_device. - Danilo ]
Signed-off-by: Danilo Krummrich <[email protected]>
2026-07-12 15:55:51 +02:00
Lyude Paul fa8cc4e306 rust: faux: Allow retrieving a bound Device
When writing up some rust code that used faux devices for unit testing, I
noticed that we never actually added the Bound device context to
faux::Registration's AsRef<device::Device> implementation. This being said:
the Registration object itself is proof that a driver is bound to the
device - so this should be safe.

Signed-off-by: Lyude Paul <[email protected]>
Reviewed-by: Alexandre Courbot <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Danilo Krummrich <[email protected]>
2026-06-25 23:13:20 +02:00
Danilo Krummrich d88f27d7f4 rust: faux: use "kernel vertical" style for imports
Convert all imports 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: Greg Kroah-Hartman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Danilo Krummrich <[email protected]>
2026-01-07 19:56:00 +01:00
Miguel Ojeda a5ba9ad417 rust: faux: fix C header link
Starting with Rust 1.91.0 (expected 2025-10-30), `rustdoc` has improved
some false negatives around intra-doc links [1], and it found a broken
intra-doc link we currently have:

    error: unresolved link to `include/linux/device/faux.h`
     --> rust/kernel/faux.rs:7:17
      |
    7 | //! C header: [`include/linux/device/faux.h`]
      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `include/linux/device/faux.h` in scope
      |
      = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
      = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
      = help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`

Our `srctree/` C header links are not intra-doc links, thus they need
the link destination.

Thus fix it.

Cc: stable <[email protected]>
Link: https://github.com/rust-lang/rust/pull/132748 [1]
Fixes: 78418f300d ("rust/kernel: Add faux device bindings")
Signed-off-by: Miguel Ojeda <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2025-08-13 17:40:28 +02:00
Alice Ryhl 2f5606afa4 device: rust: rename Device::as_ref() to Device::from_raw()
The prefix as_* should not be used for a constructor. Constructors
usually use the prefix from_* instead.

Some prior art in the stdlib: Box::from_raw, CString::from_raw,
Rc::from_raw, Arc::from_raw, Waker::from_raw, File::from_raw_fd.

There is also prior art in the kernel crate: cpufreq::Policy::from_raw,
fs::File::from_raw_file, Kuid::from_raw, ARef::from_raw,
SeqFile::from_raw, VmaNew::from_raw, Io::from_raw.

Link: https://lore.kernel.org/r/aCd8D5IA0RXZvtcv@pollux
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Danilo Krummrich <[email protected]>
2025-07-16 23:37:49 +02:00
Ethan Carter Edwards 10b20f2d1b rust/kernel/faux: mark Registration methods inline
When building the kernel on Arch Linux using on x86_64 with tools:
$ rustc --version
rustc 1.84.0 (9fc6b4312 2025-01-07)
$ clang --version
clang version 19.1.7
Target: x86_64-pc-linux-gnu

The following symbols are generated:
$ nm vmlinux | rg ' _R' | rustfilt | rg faux
ffffffff81959ae0 T <kernel::faux::Registration>::new
ffffffff81959b40 T <kernel::faux::Registration as core::ops::drop::Drop>::drop

However, these Rust symbols are wrappers around bindings in the C faux
code. Inlining these functions removes the middle-man wrapper function
After applying this patch, the above function signatures disappear.

Link: https://github.com/Rust-for-Linux/linux/issues/1145
Signed-off-by: Ethan Carter Edwards <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/jesg4yu7m6fvzmgg5tlsktrrjm36l4qsranto5mdmnucx4pvf3@nhvt4juw5es3
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2025-03-11 10:42:23 +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 <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2025-02-27 18:03:17 -08:00
Lyude Paul 6853d9d13d rust/faux: Drop #[repr(transparent)] from faux::Registration
I think this change got missed during review, we don't need
 #[repr(transparent)] since Registration just holds a single NonNull. This
attribute had originally been added by me when I was still figuring out how
the bindings should look like but got committed by mistake. So, just drop
it.

Signed-off-by: Lyude Paul <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2025-02-27 18:02:24 -08:00
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 <[email protected]>
Cc: Maíra Canal <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/2025021026-exert-accent-b4c6@gregkh
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2025-02-13 16:58:58 +01:00