Hi Stefano,

On Wed, Mar 27, 2013 at 12:50:39PM +0000, Stefano Stabellini wrote:

Check for the presence of PSCI before setting smp_ops, use PSCI if it is
available.

This is useful because at least when running on Xen it's possible to have a
PSCI node for example on a Versatile Express or an Exynos5 machine. In these
cases the PSCI SMP calls should be the ones to be called.

Remove virt_smp_ops and platsmp.c from mach-virt because they aren't needed
anymore.

[...]

+struct psci_operations psci_ops = {
+	.cpu_suspend = psci_cpu_suspend,
+	.cpu_off     = psci_cpu_off,
+	.cpu_on      = psci_cpu_on,
+	.migrate     = psci_migrate,
+};
+
+#ifdef CONFIG_SMP
+static void __init psci_smp_init_cpus(void)
+{
+}
+
+static void __init psci_smp_prepare_cpus(unsigned int max_cpus)
+{
+}
+
+static int __cpuinit psci_boot_secondary(unsigned int cpu,
+					 struct task_struct *idle)
+{
+	return psci_cpu_on(cpu_logical_map(cpu), __pa(secondary_startup));
+}
+
+static void __cpuinit psci_secondary_init(unsigned int cpu)
+{
+	gic_secondary_init(0);
+}
+
+struct smp_operations __initdata psci_smp_ops = {
+	.smp_init_cpus		= psci_smp_init_cpus,
+	.smp_prepare_cpus	= psci_smp_prepare_cpus,
+	.smp_secondary_init	= psci_secondary_init,
+	.smp_boot_secondary	= psci_boot_secondary,
+};
+#endif

As I said before, I don't agree with bolting these two interfaces together
like this and, as it stands, I'm afraid I have to NAK this patch.

A potential alternative is to have a set of virt_smp_ops, which have
wrappers around the psci functions, but that requires agreement from Xen and
KVM to implement the same PSCI interface, which feels unfair to me.

I see what you're trying to do, but I can't go along with it. Sorry.

Will