Commit 842aedc3 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Danilo Krummrich
Browse files

rust: Add cpu_relax() helper 



Add cpu_relax() helper in preparation for supporting
read_poll_timeout().

Reviewed-by: default avatarAlice Ryhl <aliceryhl@google.com>
Reviewed-by: default avatarAndreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: default avatarDaniel Almeida <daniel.almeida@collabora.com>
Acked-by: default avatarMiguel Ojeda <ojeda@kernel.org>
Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250821002055.3654160-2-fujita.tomonori@gmail.com


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 44d454fc

rust/helpers/helpers.c

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@@ -35,6 +35,7 @@ 
#include "pid_namespace.c"

#include "platform.c"

#include "poll.c"

#include "processor.c"

#include "property.c"

#include "rbtree.c"

#include "rcu.c"

rust/helpers/processor.c

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// SPDX-License-Identifier: GPL-2.0



#include <linux/processor.h>



void rust_helper_cpu_relax(void)

{

	cpu_relax();

}

rust/kernel/lib.rs

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@@ -111,6 +111,7 @@ 
pub mod platform;

pub mod prelude;

pub mod print;

pub mod processor;

pub mod rbtree;

pub mod regulator;

pub mod revocable;

rust/kernel/processor.rs

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// SPDX-License-Identifier: GPL-2.0



//! Processor related primitives.

//!

//! C header: [`include/linux/processor.h`](srctree/include/linux/processor.h)



/// Lower CPU power consumption or yield to a hyperthreaded twin processor.

///

/// It also happens to serve as a compiler barrier.

#[inline]

pub fn cpu_relax() {

    // SAFETY: Always safe to call.

    unsafe { bindings::cpu_relax() }

}