Commit Graph

12 Commits

Author SHA1 Message Date
Miguel Ojeda 275ad5e793 rust: list: remove nonexistent generic parameter in link
`ListLinks` does not take a `T` generic parameter, unlike
`ListLinksSelfPtr`.

Thus fix it, which makes it also consistent with the rest of the links
in the file.

Fixes: 40c5329459 ("rust: list: add macro for implementing ListItem")
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250719232500.822313-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-20 19:29:19 +02:00
Tamir Duberstein c77f85b347 rust: list: remove OFFSET constants
Replace `ListLinksSelfPtr::LIST_LINKS_SELF_PTR_OFFSET` with `unsafe fn
raw_get_self_ptr` which returns a pointer to the field rather than
requiring the caller to do pointer arithmetic.

Implement `HasListLinks::raw_get_list_links` in `impl_has_list_links!`,
narrowing the interface of `HasListLinks` and replacing pointer
arithmetic with `container_of!`.

Modify `impl_list_item` to also invoke `impl_has_list_links!` or
`impl_has_list_links_self_ptr!`. This is necessary to allow
`impl_list_item` to see more of the tokens used by
`impl_has_list_links{,_self_ptr}!`.

A similar API change was discussed on the hrtimer series[1].

Link: https://lore.kernel.org/all/20250224-hrtimer-v3-v6-12-rc2-v9-1-5bd3bf0ce6cc@kernel.org/ [1]
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-6-a429e75840a9@gmail.com
[ Fixed broken intra-doc links. Used the renamed
  `Opaque::cast_into`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Tamir Duberstein 5d840b4c49 rust: list: add `impl_list_item!` examples
There's a comprehensive example in `rust/kernel/list.rs` but it doesn't
exercise the `using ListLinksSelfPtr` variant nor the generic cases. Add
that here. Generalize `impl_has_list_links_self_ptr` to handle nested
fields in the same manner as `impl_has_list_links`.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-5-a429e75840a9@gmail.com
[ Fixed Rust < 1.82 build by enabling the `offset_of_nested`
  feature. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Tamir Duberstein 6a13057d50 rust: list: use fully qualified path
Use a fully qualified path rooted at `$crate` rather than relying on
imports in the invoking scope.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-4-a429e75840a9@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Tamir Duberstein 9e626edd7b rust: list: use consistent self parameter name
Refer to the self parameter of `impl_list_item!` by the same name used
in `impl_has_list_links{,_self_ptr}!`.

Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-3-a429e75840a9@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Tamir Duberstein 9cec86e4ae rust: list: use consistent type parameter style
Refer to the type parameters of `impl_has_list_links{,_self_ptr}!` by
the same name used in `impl_list_item!`. Capture type parameters of
`impl_list_item!` as `tt` using `{}` to match the style of all other
macros that work with generics.

Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-2-a429e75840a9@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Tamir Duberstein e71d7e39be rust: list: simplify macro capture
Avoid manually capturing generics; use `ty` to capture the whole type
instead.

Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250709-list-no-offset-v4-1-a429e75840a9@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:18 +02:00
Miguel Ojeda b0c7d8c9e8 rust: list: undo unintended replacement of method name
When we renamed `Opaque::raw_get` to `cast_into`, there was one
replacement that was not supposed to be there.

It does not cause an issue so far because it is inside a macro rule (the
`ListLinksSelfPtr` one) that is unused so far. However, it will start
to be used soon.

Thus fix it now.

Fixes: 64fb810bce ("rust: types: rename Opaque::raw_get to cast_into")
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250719183649.596051-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-19 23:18:16 +02:00
Alice Ryhl 64fb810bce rust: types: rename Opaque::raw_get to cast_into
In the previous patch we added Opaque::cast_from() that performs the
opposite operation to Opaque::raw_get(). For consistency with this
naming, rename raw_get() to cast_from().

There are a few other options such as calling cast_from() something
closer to raw_get() rather than renaming this method. However, I could
not find a great naming scheme that works with raw_get(). The previous
version of this patch used from_raw(), but functions of that name
typically have a different signature, so that's not a great option.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Benno Lossin <lossin@kernel.org>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-2-e4da40bdc59c@google.com
[ Removed `HrTimer::raw_get` change. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-15 22:26:11 +02:00
Tamir Duberstein fcad9bbf9e rust: enable `clippy::ptr_as_ptr` lint
In Rust 1.51.0, Clippy introduced the `ptr_as_ptr` lint [1]:

> Though `as` casts between raw pointers are not terrible,
> `pointer::cast` is safer because it cannot accidentally change the
> pointer's mutability, nor cast the pointer to other types like `usize`.

There are a few classes of changes required:
- Modules generated by bindgen are marked
  `#[allow(clippy::ptr_as_ptr)]`.
- Inferred casts (` as _`) are replaced with `.cast()`.
- Ascribed casts (` as *... T`) are replaced with `.cast::<T>()`.
- Multistep casts from references (` as *const _ as *const T`) are
  replaced with `core::ptr::from_ref(&x).cast()` with or without `::<T>`
  according to the previous rules. The `core::ptr::from_ref` call is
  required because `(x as *const _).cast::<T>()` results in inference
  failure.
- Native literal C strings are replaced with `c_str!().as_char_ptr()`.
- `*mut *mut T as _` is replaced with `let *mut *const T = (*mut *mut
  T)`.cast();` since pointer to pointer can be confusing.

Apply these changes and enable the lint -- no functional change
intended.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-1-f43b024581e8@gmail.com
[ Added `.cast()` for `opp`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-22 23:08:42 +02:00
Alice Ryhl 2003c04b05 rust: list: support heterogeneous lists
Support linked lists that can hold many different structs at once. This
is generally done using trait objects. The main challenge is figuring
what the struct is given only a pointer to the ListLinks.

We do this by storing a pointer to the struct next to the ListLinks
field. The container_of operation will then just read that pointer. When
the type is a trait object, that pointer will be a fat pointer whose
metadata is a vtable that tells you what kind of struct it is.

Heterogeneous lists are heavily used by Rust Binder. There are a lot of
so-called todo lists containing various events that need to be delivered
to userspace next time userspace calls into the driver. And there are
quite a few different todo item types: incoming transaction, changes to
refcounts, death notifications, and more.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-9-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:26:57 +02:00
Alice Ryhl 40c5329459 rust: list: add macro for implementing ListItem
Adds a macro for safely implementing the ListItem trait. As part of the
implementation of the macro, we also provide a HasListLinks trait
similar to the workqueue's HasWorkItem trait.

The HasListLinks trait is only necessary if you are implementing
ListItem using the impl_list_item macro.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-5-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-23 06:26:57 +02:00