| commit | fd2efaa4eb5317c3a86357a83a7d456a1b86a0ac | [log] [tgz] |
|---|---|---|
| author | Mark Rutland <[email protected]> | Mon Jul 16 12:30:11 2018 +0100 |
| committer | Ingo Molnar <[email protected]> | Wed Jul 25 11:53:59 2018 +0200 |
| tree | 23d5695e05edf0cf661d28cba61de17ee4e6633f | |
| parent | 4d2b25f630c731218d04f72580b4de68cb7a6e00 [diff] |
locking/atomics: Rework ordering barriers Currently architectures can override __atomic_op_*() to define the barriers used before/after a relaxed atomic when used to build acquire/release/fence variants. This has the unfortunate property of requiring the architecture to define the full wrapper for the atomics, rather than just the barriers they care about, and gets in the way of generating atomics which can be easily read. Instead, this patch has architectures define an optional set of barriers: * __atomic_acquire_fence() * __atomic_release_fence() * __atomic_pre_full_fence() * __atomic_post_full_fence() ... which <linux/atomic.h> uses to build the wrappers. It would be nice if we could undef these, along with the __atomic_op_*() wrappers, but that would break the cmpxchg() wrappers, which are written in preprocessor. Undefs would have been nice, but alas. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Will Deacon <[email protected]> Cc: Andrea Parri <[email protected]> Cc: Boqun Feng <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>