rcu: Make arch select smp_mb__after_unlock_lock() strength

The definition of smp_mb__after_unlock_lock() is currently smp_mb()
for CONFIG_PPC and a no-op otherwise.  It would be better to instead
provide an architecture-selectable Kconfig option, and select the
strength of smp_mb__after_unlock_lock() based on that option.  This
commit therefore creates ARCH_WEAK_RELEASE_ACQUIRE, has PPC select it,
and bases the definition of smp_mb__after_unlock_lock() on this new
ARCH_WEAK_RELEASE_ACQUIRE Kconfig option.

Reported-by: Ingo Molnar <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Acked-by: Michael Ellerman <[email protected]>
Cc: <[email protected]>
Reviewed-by: Josh Triplett <[email protected]>

0 files changed, 0 insertions, 0 deletions