On Wed, 27 Mar 2013, Arnd Bergmann wrote:

On Wednesday 27 March 2013, Rob Herring wrote:

quoted

No, I was thinking in the case of Xen and mach-virt, you would not set
mdesc->smp. So you would have something like this:

if (mdesc->smp)
        smp_set_ops(mdesc->smp);
else
        smp_set_ops(&psci_smp_ops);

The case that Stefano is interested in if obviously other platforms
that can either run as Dom0 under Xen with psci_smp_ops or natively
with their own smp_ops. A similar case would be a platform that
may implement psci using smc when run in secure mode but provide
its own smp_ops when run natively.

That's correct.

In both cases, it would be simpler to use psci if available but
fall back to mdesc->smp otherwise.

I agree.