On Tue, 24 Apr 2018 14:15:54 +1000 Michael Ellerman <m...@ellerman.id.au> wrote:
> From: Michal Suchanek <msucha...@suse.de> > > A no-op form of ori (or immediate of 0 into r31 and the result stored > in r31) has been re-tasked as a speculation barrier. The instruction > only acts as a barrier on newer machines with appropriate firmware > support. On older CPUs it remains a harmless no-op. > > Implement barrier_nospec using this instruction. > > mpe: The semantics of the instruction are believed to be that it > prevents execution of subsequent instructions until preceding branches > have been fully resolved and are no longer executing speculatively. > There is no further documentation available at this time. > > Signed-off-by: Michal Suchanek <msucha...@suse.de> > Signed-off-by: Michael Ellerman <m...@ellerman.id.au> > --- > mpe: Make it Book3S64 only, update comment & change log, add a > memory clobber to the asm. These all seem good to me. Thanks Michal. We should (eventually) work on the module patching problem too. Thanks, Nick
