[1] indicates that there might be need for Rust to synchronize with C
over atomic, currently the recommendation is using
`Atomic::from_ptr().op()`, however, it's more convenient to have helper
wrapper that directly perform operation over pointers. Hence add them
for load()/store()/xchg()/cmpxgh().

While working on this, I also found an issue in `from_ptr()`, therefore
fix it.

[1]: https://lore.kernel.org/rust-for-linux/20251231-rwonce-v1-0-702a10b85278@google.com/

Regards,
Boqun

Boqun Feng (2):
  rust: sync: atomic: Remove bound `T: Sync` for `Atomci::from_ptr()`
  rust: sync: atomic: Add atomic operation helpers over raw pointers

 rust/kernel/sync/atomic.rs           | 109 ++++++++++++++++++++++++++-
 rust/kernel/sync/atomic/predefine.rs |  46 +++++++++++
 2 files changed, 151 insertions(+), 4 deletions(-)

-- 
2.51.0