rust: jump_label: skip formatting generated file

After a source tree build of the kernel, and having used the `RSCPP`
rule, running `rustfmt` fails with:

error: macros that expand to items must

rust: jump_label: skip formatting generated file

After a source tree build of the kernel, and having used the `RSCPP`
rule, running `rustfmt` fails with:

error: macros that expand to items must be delimited with braces or followed by a semicolon
--> rust/kernel/arch_static_branch_asm.rs:1:27
|
1 | ...ls!("1: jmp " ... ".popsection \n\t")
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
help: change the delimiters to curly braces
|
1 | ::kernel::concat_literals!{"1: jmp " ... ".popsection \n\t"}
| ~ ~
help: add a semicolon
|
1 | ::kernel::concat_literals!("1: jmp " ... ".popsection \n\t");
| +

This file is not meant to be formatted nor works on its own since it is
meant to be textually included.

Thus skip formatting it by prefixing its name with `generated_`.

Cc: Masami Hiramatsu <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: Björn Roy Baron <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Alice Ryhl <[email protected]>
Cc: Trevor Gross <[email protected]>
Link: https://lore.kernel.org/[email protected]
Fixes: 169484ab6677 ("rust: add arch_static_branch")
Signed-off-by: Miguel Ojeda <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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jump_label: rust: pass a mut ptr to `static_key_count`

When building the rust_print sample with CONFIG_JUMP_LABEL=n, the Rust
static key support falls back to using static_key_count. This function
a

jump_label: rust: pass a mut ptr to `static_key_count`

When building the rust_print sample with CONFIG_JUMP_LABEL=n, the Rust
static key support falls back to using static_key_count. This function
accepts a mutable pointer to the `struct static_key`, but the Rust
abstractions are incorrectly passing a const pointer.

This means that builds using CONFIG_JUMP_LABEL=n and SAMPLE_RUST_PRINT=y
fail with the following error message:

error[E0308]: mismatched types
--> <root>/samples/rust/rust_print_main.rs:87:5
|
87 | / kernel::declare_trace! {
88 | | /// # Safety
89 | | ///
90 | | /// Always safe to call.
91 | | unsafe fn rust_sample_loaded(magic: c_int);
92 | | }
| | ^
| | |
| |_____types differ in mutability
| arguments to this function are incorrect
|
= note: expected raw pointer `*mut kernel::bindings::static_key`
found raw pointer `*const kernel::bindings::static_key`
note: function defined here
--> <root>/rust/bindings/bindings_helpers_generated.rs:33:12
|
33 | pub fn static_key_count(key: *mut static_key) -> c_int;
| ^^^^^^^^^^^^^^^^

To fix this, insert a pointer cast so that the pointer is mutable.

Link: https://lore.kernel.org/[email protected]
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: 169484ab6677 ("rust: add arch_static_branch")
Signed-off-by: Alice Ryhl <[email protected]>
Acked-by: Miguel Ojeda <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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rust: add arch_static_branch

To allow the Rust implementation of static_key_false to use runtime code
patching instead of the generic implementation, pull in the relevant
inline assembly from the ju

rust: add arch_static_branch

To allow the Rust implementation of static_key_false to use runtime code
patching instead of the generic implementation, pull in the relevant
inline assembly from the jump_label.h header by running the C
preprocessor on a .rs.S file. Build rules are added for .rs.S files.

Since the relevant inline asm has been adjusted to export the inline asm
via the ARCH_STATIC_BRANCH_ASM macro in a consistent way, the Rust side
does not need architecture specific code to pull in the asm.

It is not possible to use the existing C implementation of
arch_static_branch via a Rust helper because it passes the argument
`key` to inline assembly as an 'i' parameter. Any attempt to add a C
helper for this function will fail to compile because the value of `key`
must be known at compile-time.

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Wedson Almeida Filho <[email protected]>
Cc: Gary Guo <[email protected]>
Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Uros Bizjak <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Oliver Upton <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Fuad Tabba <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Anup Patel <[email protected]>
Cc: Andrew Jones <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: Conor Dooley <[email protected]>
Cc: Samuel Holland <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Bibo Mao <[email protected]>
Cc: Tiezhu Yang <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Tianrui Zhao <[email protected]>
Link: https://lore.kernel.org/[email protected]
Suggested-by: Peter Zijlstra (Intel) <[email protected]>
Co-developed-by: Miguel Ojeda <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

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rust: add static_branch_unlikely for static_key_false

Add just enough support for static key so that we can use it from
tracepoints. Tracepoints rely on `static_branch_unlikely` with a `struct
stati

rust: add static_branch_unlikely for static_key_false

Add just enough support for static key so that we can use it from
tracepoints. Tracepoints rely on `static_branch_unlikely` with a `struct
static_key_false`, so we add the same functionality to Rust.

This patch only provides a generic implementation without code patching
(matching the one used when CONFIG_JUMP_LABEL is disabled). Later
patches add support for inline asm implementations that use runtime
patching.

When CONFIG_JUMP_LABEL is unset, `static_key_count` is a static inline
function, so a Rust helper is defined for `static_key_count` in this
case. If Rust is compiled with LTO, this call should get inlined. The
helper can be eliminated once we have the necessary inline asm to make
atomic operations from Rust.

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Alex Gaynor <[email protected]>
Cc: Wedson Almeida Filho <[email protected]>
Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <[email protected]>
Cc: Benno Lossin <[email protected]>
Cc: Andreas Hindborg <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Uros Bizjak <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Oliver Upton <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Fuad Tabba <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Anup Patel <[email protected]>
Cc: Andrew Jones <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: Conor Dooley <[email protected]>
Cc: Samuel Holland <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Bibo Mao <[email protected]>
Cc: Tiezhu Yang <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Tianrui Zhao <[email protected]>
Link: https://lore.kernel.org/[email protected]
Reviewed-by: Boqun Feng <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

show more ...