On Wed, Oct 31, 2012 at 12:04:38AM +0000, Rob Herring wrote:

On 10/30/2012 05:47 PM, Russell King - ARM Linux wrote:

quoted

On Tue, Oct 30, 2012 at 12:21:20PM -0500, Rob Herring wrote:

quoted

Looking at this some more, arm64 doesn't need most of what's in gic.h.
The register defines should be moved into the .c file. The remaining
function declarations either are not needed (i.e. gic_init) or should
should be done like the handle_irq function pointer init. We don't want
to have platform code calling gic_cascade_irq or gic_raise_softirq
directly.

Softirqs are about the SPIs which are used for SMP IPIs and platform
specific wakeup of CPUs.  And platform code _needs_ to specify the
way IPIs are delivered on the platform.  irqchip can't do that because
irqchip knows nothing about SPIs (neither does genirq.)

Right. v7 is unchanged, so the question is really only about how v8 will
do this. Hopefully, ARM is standardizing this for v8. We probably want
the gic (or other irqchip) to setup a raise_softirq function ptr on init
rather than having a direct call to gic_raise_softirq.

In my sample ARMv8 model code I have an older version of gic.c moved to
drivers/irqchip and modified just for the arm64 needs. The gic_of_init()
function calls set_smp_cross_call(git_raise_softirq).

http://git.kernel.org/?p=linux/kernel/git/cmarinas/linux-aarch64.git;a=commitdiff;h=5cd20480f4d7b56160b3312df14fba3b2bda6798

The gic_secondary_init() is done from a CPU notifier as I wanted to
separate this from the SoC code (even on arch/arm, all the calls to
gic_secondary_init() are the same, so it could be factored out to a
notifier or some function pointer set by gic.c).

And let's assume there is no need for gic_cascade_irq().

-- 
Catalin