On Thu, 21 Jul 2016, Auger Eric wrote:

On 20/07/2016 10:12, Thomas Gleixner wrote:

quoted

On Tue, 19 Jul 2016, Eric Auger wrote:

quoted

+bool msi_doorbell_safe(void)
+{
+	struct irqchip_doorbell *db;
+	bool irq_remapping = true;
+
+	mutex_lock(&irqchip_doorbell_mutex);
+	list_for_each_entry(db, &irqchip_doorbell_list, next) {
+		irq_remapping &= db->info.irq_remapping;

db->info.irq_remapping is set in msi_doorbell_register(). So you can keep book
about that there. No need to iterate here.

Yes makes sense to store the info at registration time. Currently this
function is not in any fast path but that's cleaner from a general
perspective. I will need to do such iteration at un-registration though.

Two simple counter should be sufficient.

  nr_registered_bells;
  nr_remapped_bells;

....

Thanks,

	tglx