• Peter Zijlstra's avatar
    arch: Prepare for smp_mb__{before,after}_atomic() · febdbfe8
    Peter Zijlstra authored
    Since the smp_mb__{before,after}*() ops are fundamentally dependent on
    how an arch can implement atomics it doesn't make sense to have 3
    variants of them. They must all be the same.
    
    Furthermore, the 3 variants suggest they're only valid for those 3
    atomic ops, while we have many more where they could be applied.
    
    So move away from
    smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the
    interface to just the two: smp_mb__{before,after}_atomic().
    
    This patch prepares the way by introducing default implementations in
    asm-generic/barrier.h that default to a full barrier and providing
    __deprecated inlines for the previous 6 barriers if they're not
    provided by the arch.
    
    This should allow for a mostly painless transition (lots of deprecated
    warns in the interim).
    Signed-off-by: 's avatarPeter Zijlstra <peterz@infradead.org>
    Acked-by: 's avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
    Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: "Chen, Gong" <gong.chen@linux.intel.com>
    Cc: John Sullivan <jsrhbz@kanargh.force9.co.uk>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
    Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
    Cc: "Theodore Ts'o" <tytso@mit.edu>
    Cc: linux-arch@vger.kernel.org
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: 's avatarIngo Molnar <mingo@kernel.org>
    febdbfe8
bitops.h 1.05 KB