[PATCH v3 3/7] irqchip: gic: Support hierarchy irq domain.

Marc Zyngier
2014-10-13T09:44:43Z

On 13/10/14 10:27, Arnd Bergmann wrote:
> On Monday 13 October 2014 09:56:20 Marc Zyngier wrote:
>> if (irq_domain_is_hierarchy(domain)) {
>> + if (domain->ops->xlate) {
>> + /*
>> + * If we've already configured this interrupt,
>> + * don't do it again, or hell will break loose.
>> + */
>> + if (domain->ops->xlate(domain, irq_data->np,
>> + irq_data->args,
>> + irq_data->args_count,
>> + &hwirq, &type))
>> + return 0;
>> +
>> + virq = irq_find_mapping(domain, hwirq);
>> + if (virq)
>> + return virq;
>> + }
>> virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, irq_data);
>> return virq <= 0 ? 0 : virq;
>> }
>>
>> Thoughts?
>
> Using irq_find_mapping() first is probably the right approach, that
> is what irq_create_mapping() does too, and I suppose we want those
> to be symmetric.

Ah, good point. I somehow missed that.

> mt_sysirq_domain_alloc() in patch 4 has the irq_find_domain check
> in it, which I guess we can remove when it has moved to the common
> code.
>
> I don't see irq_domain_alloc_irqs() in linux-next or older kernels, where
> does that get introduced?

This is part of Jiang's domain hierarchy series:
https://patchwork.ozlabs.org/patch/388279/

which I plan to use to get rid of the ugly gic_extn hack that only Tegra
uses (but that everyone tries to abuse), and also for the GICv2m support.

Thanks,

M.
--
Jazz is not dead. It just smells funny...