tree 840c9834aa9775c0e71ba3add07a985e236c1bf6
parent 4c7ab87a2396d61beae362d5f0c900dfe452a6c9
author Boqun Feng <boqun.feng@gmail.com> 1730219326 -0700
committer Boqun Feng <boqun.feng@gmail.com> 1750015970 -0700

rust: sync: Add memory barriers

Memory barriers are building blocks for concurrent code, hence provide
a minimal set of them.

The compiler barrier, barrier(), is implemented in inline asm instead of
using core::sync::atomic::compiler_fence() because memory models are
different: kernel's atomics are implemented in inline asm therefore the
compiler barrier should be implemented in inline asm as well. Also it's
currently only public to the kernel crate until there's a reasonable
driver usage.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>