Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
"In terms of lines, most changes this time are on the pinned-init API
and infrastructure. Whil

Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
"In terms of lines, most changes this time are on the pinned-init API
and infrastructure. While we have a Rust version upgrade, and thus a
bunch of changes from the vendored 'alloc' crate as usual, this time
those do not account for many lines.

Toolchain and infrastructure:

- Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
smaller jump compared to the last time.

This version allows us to remove the '__rust_*' allocator functions
-- the compiler now generates them as expected, thus now our
'KernelAllocator' is used.

It also introduces the 'offset_of!' macro in the standard library
(as an unstable feature) which we will need soon. So far, we were
using a declarative macro as a prerequisite in some not-yet-landed
patch series, which did not support sub-fields (i.e. nested
structs):

#[repr(C)]
struct S {
a: u16,
b: (u8, u8),
}

assert_eq!(offset_of!(S, b.1), 3);

- Upgrade to bindgen 0.65.1. This is the first time we upgrade its
version.

Given it is a fairly big jump, it comes with a fair number of
improvements/changes that affect us, such as a fix needed to
support LLVM 16 as well as proper support for '__noreturn' C
functions, which are now mapped to return the '!' type in Rust:

void __noreturn f(void); // C
pub fn f() -> !; // Rust

- 'scripts/rust_is_available.sh' improvements and fixes.

This series takes care of all the issues known so far and adds a
few new checks to cover for even more cases, plus adds some more
help texts. All this together will hopefully make problematic
setups easier to identify and to be solved by users building the
kernel.

In addition, it adds a test suite which covers all branches of the
shell script, as well as tests for the issues found so far.

- Support rust-analyzer for out-of-tree modules too.

- Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.

- Drop 'scripts/is_rust_module.sh' since it is not needed anymore.

Macros crate:

- New 'paste!' proc macro.

This macro is a more flexible version of 'concat_idents!': it
allows the resulting identifier to be used to declare new items and
it allows to transform the identifiers before concatenating them,
e.g.

let x_1 = 42;
paste!(let [<x _2>] = [<x _1>];);
assert!(x_1 == x_2);

The macro is then used for several of the pinned-init API changes
in this pull.

Pinned-init API:

- Make '#[pin_data]' compatible with conditional compilation of
fields, allowing to write code like:

#[pin_data]
pub struct Foo {
#[cfg(CONFIG_BAR)]
a: Bar,
#[cfg(not(CONFIG_BAR))]
a: Baz,
}

- New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait,
which allows 'unsafe' implementations for structs where every field
implements the 'Zeroable' trait, e.g.:

#[derive(Zeroable)]
pub struct DriverData {
id: i64,
buf_ptr: *mut u8,
len: usize,
}

- Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for
zeroing all other fields, e.g.:

pin_init!(Buf {
buf: [1; 64],
..Zeroable::zeroed()
});

- New '{,pin_}init_array_from_fn()' functions to create array
initializers given a generator function, e.g.:

let b: Box<[usize; 1_000]> = Box::init::<Error>(
init_array_from_fn(|i| i)
).unwrap();

assert_eq!(b.len(), 1_000);
assert_eq!(b[123], 123);

- New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
execute a closure on the value directly after initialization, e.g.:

let foo = init!(Foo {
buf <- init::zeroed()
}).chain(|foo| {
foo.setup();
Ok(())
});

- Support arbitrary paths in init macros, instead of just identifiers
and generic types.

- Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
'Opaque<T>' types.

- Make initializer values inaccessible after initialization.

- Make guards in the init macros hygienic.

'allocator' module:

- Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
misaligned allocations when the Rust 1.71.1 upgrade is applied
later in this pull.

The equivalent fix for the previous compiler version (where
'KernelAllocator' is not yet used) was merged into 6.5 already,
which added the 'krealloc_aligned()' function used here.

- Implement 'KernelAllocator::{realloc, alloc_zeroed}' for
performance, using 'krealloc_aligned()' too, which forwards the
call to the C API.

'types' module:

- Make 'Opaque' be '!Unpin', removing the need to add a
'PhantomPinned' field to Rust structs that contain C structs which
must not be moved.

- Make 'Opaque' use 'UnsafeCell' as the outer type, rather than
inner.

Documentation:

- Suggest obtaining the source code of the Rust's 'core' library
using the tarball instead of the repository.

MAINTAINERS:

- Andreas and Alice, from Samsung and Google respectively, are
joining as reviewers of the "RUST" entry.

As well as a few other minor changes and cleanups"

* tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits)
rust: init: update expanded macro explanation
rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`
rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`
rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
rust: init: add support for arbitrary paths in init macros
rust: init: add functions to create array initializers
rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields
rust: init: make initializer values inaccessible after initializing
rust: init: wrap type checking struct initializers in a closure
rust: init: make guards in the init macros hygienic
rust: add derive macro for `Zeroable`
rust: init: make `#[pin_data]` compatible with conditional compilation of fields
rust: init: consolidate init macros
docs: rust: clarify what 'rustup override' does
docs: rust: update instructions for obtaining 'core' source
docs: rust: add command line to rust-analyzer section
scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`
rust: bindgen: upgrade to 0.65.1
rust: enable `no_mangle_with_rust_abi` Clippy lint
rust: upgrade to Rust 1.71.1
...

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rust: macros: add `paste!` proc macro

This macro provides a flexible way to concatenated identifiers together
and it allows the resulting identifier to be used to declare new items,
which `concat_id

rust: macros: add `paste!` proc macro

This macro provides a flexible way to concatenated identifiers together
and it allows the resulting identifier to be used to declare new items,
which `concat_idents!` does not allow. It also allows identifiers to be
transformed before concatenated.

The `concat_idents!` example

let x_1 = 42;
let x_2 = concat_idents!(x, _1);
assert!(x_1 == x_2);

can be written with `paste!` macro like this:

let x_1 = 42;
let x_2 = paste!([<x _1>]);
assert!(x_1 == x_2);

However `paste!` macro is more flexible because it can be used to create
a new variable:

let x_1 = 42;
paste!(let [<x _2>] = [<x _1>];);
assert!(x_1 == x_2);

While this is not possible with `concat_idents!`.

This macro is similar to the `paste!` crate [1], but this is a fresh
implementation to avoid vendoring large amount of code directly. Also, I
have augmented it to provide a way to specify span of the resulting
token, allowing precise control.

For example, this code is broken because the variable is declared inside
the macro, so Rust macro hygiene rules prevents access from the outside:

macro_rules! m {
($id: ident) => {
// The resulting token has hygiene of the macro.
paste!(let [<$id>] = 1;)
}
}

m!(a);
let _ = a;

In this version of `paste!` macro I added a `span` modifier to allow
this:

macro_rules! m {
($id: ident) => {
// The resulting token has hygiene of `$id`.
paste!(let [<$id:span>] = 1;)
}
}

m!(a);
let _ = a;

Link: http://docs.rs/paste/ [1]
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230628171108.1150742-1-gary@garyguo.net
[ Added SPDX license identifier as discussed in the list and fixed typo. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

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