Re: IPLs - One too many?

[Chris Gilbert <chris%dokein.co.uk@localhost>]

Toru Nishimura wrote:
> Chris Gilbert said;
> 
>> Currently all interrupts are routed to IRQ, and we have to handle nested
>> interrupts, so we don't block clock irqs, masking and unmasking things
>> in the PIC, all of which is added complexity and overhead.
>>
>> If we only need interrupts at two levels, and the hardware supports it,
>> we can handle all the interrupt priorities in the hardware, and bypass
>> quite a bit of code (and hopefully give a performance gain)
> 
> In my understanding different and incompatible rework efforts have been
> made for NetBSD/arm interrupt foundation.  Given this statements can
> I expect those will get settled down in a single and coherent shape which
> is able to adapt many ARMs?

Probably end up with two.  One traditional type that has to nest
interrupts (eg for iomd based systems) and one for routable IRQ/FIQ lines.

Although I think it should be possible to use a common API for both
types, so we still get a common core piece of PIC handling code.

Thanks,
Chris