• Peter Zijlstra's avatar
    locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}() · a8bcccab
    Peter Zijlstra authored
    Implement FETCH-OP atomic primitives, these are very similar to the
    existing OP-RETURN primitives we already have, except they return the
    value of the atomic variable _before_ modification.
    
    This is especially useful for irreversible operations -- such as
    bitops (because it becomes impossible to reconstruct the state prior
    to modification).
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-arch@vger.kernel.org
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    a8bcccab
atomic64_32.h 8.26 KB