On Tue, 2 Jun 2015, James Hogan wrote: > > diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h > > index 2b8bbbcb9be0..d2a63abfc7c6 100644 > > --- a/arch/mips/include/asm/barrier.h > > +++ b/arch/mips/include/asm/barrier.h > > @@ -96,9 +96,15 @@ > > # define smp_rmb() barrier() > > # define smp_wmb() __syncw() > > # else > > +# ifdef CONFIG_MIPS_LIGHTWEIGHT_SYNC > > +# define smp_mb() __asm__ __volatile__("sync 0x10" : : :"memory") > > +# define smp_rmb() __asm__ __volatile__("sync 0x13" : : :"memory") > > +# define smp_wmb() __asm__ __volatile__("sync 0x4" : : :"memory") > > binutils appears to support the sync_mb, sync_rmb, sync_wmb aliases > since version 2.21. Can we safely use them? I suggest that we don't -- we still officially support binutils 2.12 and have other places where we even use `.word' to insert instructions current versions of binutils properly handle. It may be worth noting in a comment though that these encodings correspond to these operations that you named. Maciej