[RFC PATCH] irq: add irq_domain translation infrastructure

[Benjamin Herrenschmidt]

On Mon, 2011-06-27 at 11:00 +0200, Sebastian Andrzej Siewior wrote:
> * Grant Likely | 2011-05-26 00:54:38 [-0600]:
> 
> >diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
> >index 39645b6..9891cd4 100644
> >--- a/arch/x86/kernel/devicetree.c
> >+++ b/arch/x86/kernel/devicetree.c
> >@@ -371,36 +321,49 @@ static struct of_ioapic_type of_ioapic_type[] =
> > 	},
> > };
> > 
> >-static int ioapic_xlate(struct irq_domain *id, const u32 *intspec, u32 intsize,
> >-			u32 *out_hwirq, u32 *out_type)
> >+static int ioapic_dt_translate(struct irq_domain *domain,
> >+				struct device_node *controller,
> >+				const u32 *intspec, u32 intsize,
> >+				irq_hw_number_t *out_hwirq, u32 *out_type)
> > {
> >-	struct mp_ioapic_gsi *gsi_cfg;
> > 	struct io_apic_irq_attr attr;
> > 	struct of_ioapic_type *it;
> > 	u32 line, idx, type;
> >+	int rc;
> > 
> >-	if (intsize < 2)
> >+	if (controller != domain->of_node)
> > 		return -EINVAL;
> 
> Is there a reason not havining the (controller != domain->of_node) check
> in irq_create_of_mapping()?

Not all domains are associated with a single OF node.

Take xics, where there can be quite a few "source controllers" which act
as device-tree interrupt parents but there's a single global domain.
 
Cheers,
Ben.