handle_prio_irq is almost identical with handle_fasteoi_irq. The
subtle differences are

1) The handler checks for IRQ_DISABLED after the device handler has
   been called. In case it's set it masks the interrupt.

2) When the handler sees IRQ_DISABLED on entry it masks the interupt
   in the same way as handle_fastoei_irq, but does not set the
   IRQ_PENDING flag.

3) Instead of gracefully handling a recursive interrupt it crashes the
   kernel.

#1 is just relevant when a device handler calls disable_irq_nosync()
   and it does not matter whether we mask the interrupt right away or
   not. We handle lazy masking for disable_irq anyway, so there is no
   real reason to have this extra mask in place.

#2 will prevent the resend of a pending interrupt, which can result in
   lost interrupts for edge type interrupts. For level type interrupts
   the resend is a noop in the generic code. According to the
   datasheet all interrupts are level type, so marking them as such
   will result in the exact same behaviour as the private
   handle_prio_irq implementation.

#3 is just stupid. Crashing the kernel instead of handling a problem
   gracefully is just wrong. With the current semantics- all handlers
   run with interrupts disabled - this is even more wrong.

Rename ack to eoi, remove the unused mask_ack, switch to
handle_fasteoi_irq and remove the private function.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: NUwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
LKML-Reference: <20110202212552.299898447@linutronix.de>

Signed-off-by: NLennert Buytenhek <buytenh@secretlab.ca>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

so we could move kstat_irqs array to irq_desc struct.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This just leaves include/asm-arm/plat-* to deal with.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There are 43 includes of asm/mach-types.h by files that don't
reference anything from that file.  Remove these unnecessary
includes.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

No file should be explicitly referencing its own platform headers
by specifying an absolute include path.  Fix these paths to use
standard <asm/arch/...> includes.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The actual warning is
	arch/arm/mach-ns9xxx/irq.c:65:6: warning: symbol 'handle_prio_irq' was not declared. Should it be static?
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

When I copy-adapted handle_level_irq I skipped note_interrupt because
I considered it unimportant.  If I had understand its importance I would
have saved myself some ours of debugging.
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

When an irq is reported all lower prio irqs are masked until the current
irq is acked.  So never leave handle_prio_irq without acking.

desc->status & IRQ_INPROGRESS should never become true because the current
irq is masked until it is acked, too.
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

prio2irq(0) is the highest prioritized interrupt.  For now there is no
binary change intended.

If you intend to change the priorisation, you have to assert:

	∀ x ∈ {0, 1, ⋯ 31}: (irq2prio ∘ prio2irq)(x) = x
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

The irq controller automatically masks the current and all lower prioritised
tasks until the current irq is acked.
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

The hardware team changed some things that were taken as being common to
all ns9xxx processors up to now.

This patch addresses:

- irqs: s/IRQ_/IRQ_NS9360_/

- system module registers: some registers are still general, their
  definition lives now in include/asm-arm/arch-ns9xxx/regs-sys-common.h.
  The ns9360 specific ones are in .../regs-sys-ns9360.h
  As a result ns9360_systemclock cannot be static inline any more as its
  definition needs regs-sys-ns9360.h.  This becomes a real problem when
  adding support for ns9215 as this will need regs-sys-ns9215.h and
  including both files will not work.  For the same reason
  ns9360_reset() is now non-inline and gpio functions live in their own
  file.

- register mapping: s/ns9xxx_map_io/ns9360_map_io/

- timer registers:  move time.c to time-ns9360.c;
  s/ns9xxx_timer/ns9360_timer/
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

As a consequence registers are now accessed with __raw_{read,write}[bl].
Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now the drivers are responsible to clear the irq in the respective
device, which seems to be the normal thing to do.

So the ack'ing of the timer irq moved to time.c.
Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The HRM states that is must be done this way ...
Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

make ns9xxx_ack_irq_functions static and add one include to get declarations
for ns9xxx_map_io and ns9xxx_init_machine.
Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NUwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>