RFC, GIC based smp_cross_call cleanup suggestion

[Colin Cross]

On Sat, Apr 2, 2011 at 1:51 AM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Fri, Apr 01, 2011 at 04:55:02PM -0600, Grant Likely wrote:
>> On Fri, Apr 1, 2011 at 4:26 PM, John Linn <John.Linn at xilinx.com> wrote:
>> > I’m getting ready to submit a patch to add SMP to Xilinx code. I notice that
>> > smp_cross_call for all GIC based platforms is duplicated across each
>> > platform in smp.h.
>> >
>> >
>> >
>> > I thought I’d try to jump in to help with some cleanup, although I realize
>> > it’s minimal, I have to start somewhere.
>> >
>> >
>> >
>> > What about moving the smp_cross_call for GIC based designs into gic.h?
>>
>> Go for it.  It's an obvious cleanup.
>
> That assumes that all SMP implementations will always have a GIC.  It
> looks to me like this is conditional on shmobile, and so I don't think
> its that trivial - maybe Paul or Magnus can first indicate why this is.

OMAP4 may also require a custom smp_cross_call implementation if CPU
idle is going to be supported in SMP - in CPU off idle modes, a GIC
SGI will not wake the CPU, and a write directly to the CPU's power
management controller or an external interrupt source would be
required.