genirq: Remove IRQF_DISABLED from core code

Remove all code which is related to IRQF_DISABLED from the core kernel
code. IRQF_DISABLED still exists as a flag, but becomes a NOOP and
will be removed after a grace period. That way we can easily revert to
the previous behaviour by just restoring the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>
LKML-Reference: <20100326000405.991244690@linutronix.de>
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index ed511af..9c31c2e 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -589,3 +589,10 @@
 	Generally invoked by accident today.
 	Seen as doing more harm than good.
 Who:	Len Brown <len.brown@intel.com>
+
+----------------------------
+
+What:	IRQF_DISABLED
+When:	2.6.36
+Why:	The flag is a NOOP as we run interrupt handlers with interrupts disabled
+Who:	Thomas Gleixner <tglx@linutronix.de>