[PATCH] powerpc: add compile-time support for lbarx, lwarx

[Segher Boessenkool]

On Sun, Nov 08, 2020 at 09:01:52PM +0100, Gabriel Paubert wrote:
> On Sat, Nov 07, 2020 at 05:42:57AM -0600, Segher Boessenkool wrote:
> > On Sat, Nov 07, 2020 at 08:12:13AM +0100, Gabriel Paubert wrote:
> > > On Sat, Nov 07, 2020 at 01:23:28PM +1000, Nicholas Piggin wrote:
> > > > ISA v2.06 (POWER7 and up) as well as e6500 support lbarx and lwarx.
> > > 
> > > Hmm, lwarx exists since original Power AFAIR,
> > 
> > Almost: it was new on PowerPC.
> 
> I stand corrected. Does this mean that Power1 (and 2 I believe) had 
> no SMP support?

As I understand it, that's correct.  Of course you always can do SMP "by
hand" -- you can do all synchronisation via software (perhaps using some
knowledge of the specific hardware you're running on), it's just slow
(and usually not portable).  Compare to SMP on 603 for example.


Segher