mirror of
https://github.com/torvalds/linux.git
synced 2026-04-18 14:53:58 -04:00
300e53b3d3
Add READ_ONCE/WRITE_ONCE based helpers for i8 and i16 types to support
relaxed atomic operations in Rust.
While relaxed operations could be implemented purely in Rust using
read_volatile() and write_volatile(), using C's READ_ONCE() and
WRITE_ONCE() macros ensures complete consistency with the kernel
memory model.
These helpers expose different symbol names than their C counterparts
so they are split into atomic_ext.c instead of atomic.c. The symbol
names; the names make the interface Rust/C clear, consistent with
i32/i64.
[boqun: Rename the functions from {load,store} to {read,set} to avoid
future adjustment]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251211113826.1299077-3-fujita.tomonori@gmail.com
45 lines
850 B
C
45 lines
850 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include <asm/barrier.h>
|
|
#include <asm/rwonce.h>
|
|
|
|
__rust_helper s8 rust_helper_atomic_i8_read(s8 *ptr)
|
|
{
|
|
return READ_ONCE(*ptr);
|
|
}
|
|
|
|
__rust_helper s8 rust_helper_atomic_i8_read_acquire(s8 *ptr)
|
|
{
|
|
return smp_load_acquire(ptr);
|
|
}
|
|
|
|
__rust_helper s16 rust_helper_atomic_i16_read(s16 *ptr)
|
|
{
|
|
return READ_ONCE(*ptr);
|
|
}
|
|
|
|
__rust_helper s16 rust_helper_atomic_i16_read_acquire(s16 *ptr)
|
|
{
|
|
return smp_load_acquire(ptr);
|
|
}
|
|
|
|
__rust_helper void rust_helper_atomic_i8_set(s8 *ptr, s8 val)
|
|
{
|
|
WRITE_ONCE(*ptr, val);
|
|
}
|
|
|
|
__rust_helper void rust_helper_atomic_i8_set_release(s8 *ptr, s8 val)
|
|
{
|
|
smp_store_release(ptr, val);
|
|
}
|
|
|
|
__rust_helper void rust_helper_atomic_i16_set(s16 *ptr, s16 val)
|
|
{
|
|
WRITE_ONCE(*ptr, val);
|
|
}
|
|
|
|
__rust_helper void rust_helper_atomic_i16_set_release(s16 *ptr, s16 val)
|
|
{
|
|
smp_store_release(ptr, val);
|
|
}
|