[PATCH 1/3] Add a new member name to structure irq_host

[Zhang Wei-r63237]

Hi, Ben, 

Thanks! Please see my inline comments.

> 
> Well, you would have to look at a cell blade or pSeries machine
> device-tree, I don't have one at hand in DTS form... but basically,
> those don't have a 1:1 relationship between hosts and nodes.

Is there any problem when the relationship between hosts and nodes is
not 1:1?

The mapping method is defined in irq_alloc_host(). If there is only one
host for many nodes,
then these nodes will use the same mapping. Such as iic_host, the
IRQ_HOST_MAP_LINEAR
is used for its all nodes. We do _not_ care which node, we just care
which virq is mapped from which host's hw irq.

> 
> Anyway, I discussed with Michael today and it might be a good idea to
> provide an optional device node field in the host struct that can be
> used by the majority of the PICs that have one host == one node, that
> would provide a good default for the name() function.
> 

But we have some irq host which has not OF-node bound.

Cheers!
Wei.