genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier

genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier

commit 9bab0b7fbaceec47d32db51cd9e59c82fb071f5a upstream

This adds a mechanism to resume selected IRQs during syscore_resume
instead of dpm_resume_noirq.

Under Xen we need to resume IRQs associated with IPIs early enough
that the resched IPI is unmasked and we can therefore schedule
ourselves out of the stop_machine where the suspend/resume takes
place.

This issue was introduced by 676dc3cf5bc3 "xen: Use IRQF_FORCE_RESUME".

Back ported to 2.6.32 (which lacks syscore support) by calling the relavant
resume function directly from sysdev_resume).

v2: Fixed non-x86 build errors.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[PG: this v2 backport taken from v2.6.32.49 stable, commit 5e87d8ee34e3]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>