[PATCH 2/11] cell: generalize io-workarounds code

[Ishizaki Kou]

Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote:
> On Fri, 2008-04-04 at 15:42 +0900, Ishizaki Kou wrote:
> > 
> > As you pointed, spider I/O functions in Cell blades need 2 step
> > indirections by our patch. Shall I make another one for Cell blades
> > whose spider I/O functions need one step indirection?
> > (But you will need 2 step indirections when you use PCI-ex.)
> 
> I think the blades will need the same stuff as celleb since it's
> possible to use the PCI-Express on them too.
> 
> Maybe an option is to do a if () / else statement rather than a function
> pointer in there, it would at least be cheaper in term of CPU cycle
> don't you think ? Anyway, do as you prefer.

I want to keep my patch as it is, because I think it is easier to add
function pointers than if () / else statement when someone adds new
I/O functions to the io-workaround. For 2.6.27 or later, I think about
adding null I/O functions for Celleb internal pci bus to reduce
overhead for searching bus.

Best regards,
Kou Ishizaki