Re: [PATCH RFC 0/7] Adding core support for wire-MSI bridges

From: Marc Zyngier
Date: Fri Oct 16 2015 - 04:48:34 EST


Hi Gerry,

On 16/10/15 02:55, Jiang Liu wrote:
> On 2015/10/15 23:39, Marc Zyngier wrote:
>> There seems to be a new class of interrupt controller out there whose
>> sole purpose (apart from making everybody's life a nightmare) is to
>> turn wired interrupts into MSIs.
>>
>> Instead of considering that the MSIs allocated to a device are for the
>> direct use of that device, we can turn this set of MSIs into a irq
>> domain, and use that domain to build a standard irqchip on top of
>> that.
> Hi Marc,
> There's a working to enable Intel VMD storage device, which
> has the similar requirement. Basically a PCIe hierarchy is hidden
> behind a parent PCIe device, so we need to use the PCIe irqs on parent
> to de-multiple PCIe IRQs from hidden PCIe devices. Seems a chance for
> consolidation here.

Do you know if there is a 1-1 mapping between the interrupts seen by the
parent device and those seen by the hidden devices? Or is it a case of
having to demultiplex the MSIs? Looks like the former, but I'd like to
be sure.

I just had a quick look at the code there:
https://lkml.org/lkml/2015/8/27/674

Is there anything more recent?

> cc Keith Busch <keith.busch@xxxxxxxxx> who is the author of
> VMD device driver.

Sure, will do when I repost this (probably in a few weeks), and assuming
this fits the bill for Thomas and the MBIGEN folks.

Thanks,

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