Commit 9dc04365 authored by Wedson Almeida Filho's avatar Wedson Almeida Filho Committed by Miguel Ojeda
Browse files

rust: sync: add `Arc` for ref-counted allocations 



This is a basic implementation of `Arc` backed by C's `refcount_t`. It
allows Rust code to idiomatically allocate memory that is ref-counted.

Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarWedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: default avatarAlice Ryhl <aliceryhl@google.com>
Reviewed-by: default avatarGary Guo <gary@garyguo.net>
Reviewed-by: default avatarVincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent cb7d9def

rust/bindings/bindings_helper.h

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
 */



#include <linux/slab.h>

#include <linux/refcount.h>



/* `bindgen` gets confused at certain things. */

const gfp_t BINDINGS_GFP_KERNEL = GFP_KERNEL;

rust/bindings/lib.rs

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ mod bindings_raw { 
#[allow(dead_code)]

mod bindings_helper {

    // Import the generated bindings for types.

    use super::bindings_raw::*;

    include!(concat!(

        env!("OBJTREE"),

        "/rust/bindings/bindings_helpers_generated.rs"

rust/helpers.c

+19 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 


#include <linux/bug.h>

#include <linux/build_bug.h>

#include <linux/refcount.h>



__noreturn void rust_helper_BUG(void)

{
@@ -27,6 +28,24 @@ __noreturn void rust_helper_BUG(void) 
}

EXPORT_SYMBOL_GPL(rust_helper_BUG);



refcount_t rust_helper_REFCOUNT_INIT(int n)

{

	return (refcount_t)REFCOUNT_INIT(n);

}

EXPORT_SYMBOL_GPL(rust_helper_REFCOUNT_INIT);



void rust_helper_refcount_inc(refcount_t *r)

{

	refcount_inc(r);

}

EXPORT_SYMBOL_GPL(rust_helper_refcount_inc);



bool rust_helper_refcount_dec_and_test(refcount_t *r)

{

	return refcount_dec_and_test(r);

}

EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test);



/*

 * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type

 * as the Rust `usize` type, so we can use it in contexts where Rust

rust/kernel/lib.rs

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ mod static_assert; 
#[doc(hidden)]

pub mod std_vendor;

pub mod str;

pub mod sync;

pub mod types;



#[doc(hidden)]

rust/kernel/sync.rs

0 → 100644
+10 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



//! Synchronisation primitives.

//!

//! This module contains the kernel APIs related to synchronisation that have been ported or

//! wrapped for usage by Rust code in the kernel.



mod arc;



pub use arc::Arc;