[PATCH] irq: move some interrupt arch_* functions into struct irq_chip.

[Ian Campbell]

On Wed, 2010-03-10 at 10:55 +0000, ijc at hellion.org.uk wrote:
> 
> arch_init_chip_data cannot be moved into struct irq_chip at this time
> because irq_desc->chip is not known at the time the irq_desc is
> setup. For now rename arch_init_chip_data to arch_init_irq_desc (for
> PowerPC, the only other user, whose usage better matches the new name)
> and on x86 convert arch_init_chip_data to ioapic_init_chip_data and
> call this whenever the IO APIC code allocates a new IRQ.

One idea I had to improve this was to add a struct irq_chip * as a
parameter to irq_to_desc_alloc_node. The new parameter potentially could
be NULL for current behaviour. Does that sound like a reasonable
approach?

Ian.