The radix tree retry logic got a bit of an overhaul and subsequently
broke the virtual IRQ subgroup build. Simply switch over to
radix_tree_deref_retry() as per the filemap changes, which the virq
lookup logic was modelled after in the first place.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

There's no need to iterative over every single irq_desc when we can
already work out which IRQs have a backing descriptor via the shiny new
for_each_active_irq(). Switch to that instead.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Now that the genirq code provides an IRQ bitmap of its own and the
necessary API to manipulate it, there's no need to keep our own version
around anymore.

In the process we kill off some unused IRQ reservation code, with future
users now having to tie in to the genirq API as normal.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Switch over to the new allocator functions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The balancing stubs obviously need to be static inline..
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The Kconfig and Makefile were overlooked, add those in now to improve
odds of building.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This splits up the sh intc core in to something more vaguely resembling
a subsystem. Most of the functionality was alread fairly well
compartmentalized, and there were only a handful of interdependencies
that needed to be resolved in the process.

This also serves as future-proofing for the genirq and sparseirq rework,
which will make some of the split out functionality wholly generic,
allowing things to be killed off in place with minimal migration pain.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>