When the system enters suspend, it disables all interrupts in
suspend_device_irqs(), including the interrupts marked EARLY_RESUME.

On the resume side things are different. The EARLY_RESUME interrupts
are reenabled in sys_core_ops->resume and the non EARLY_RESUME
interrupts are reenabled in the normal system resume path.

When suspend_noirq() failed or suspend is aborted for any other
reason, we might omit the resume side call to sys_core_ops->resume()
and therefor the interrupts marked EARLY_RESUME are not reenabled and
stay disabled forever.

To solve this, enable all irqs unconditionally in irq_resume()
regardless whether interrupts marked EARLY_RESUMEhave been already
enabled or not.

This might try to reenable already enabled interrupts in the non
failure case, but the only affected platform is XEN and it has been
confirmed that it does not cause any side effects.

[ tglx: Massaged changelog. ]
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Acked-by-and-tested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NHeiko Stuebner <heiko@sntech.de>
Reviewed-by: NPavel Machek <pavel@ucw.cz>
Cc: <ian.campbell@citrix.com>
Cc: <rjw@rjwysocki.net>
Cc: <len.brown@intel.com>
Cc: <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1385388587-16442-1-git-send-email-ldewangan@nvidia.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

If an wakeup interrupt has been disabled before the suspend code
disables all interrupts then we have to ignore the pending flag.

Otherwise we would abort suspend over and over as nothing clears the
pending flag because the interrupt is disabled.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: NeilBrown <neilb@suse.de>

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 676dc3cf "xen: Use IRQF_FORCE_RESUME".
Signed-off-by: NIan 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
Cc: stable@kernel.org (at least to 2.6.32.y)
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

On suspend we disable all interrupts in the core code, but this does
not mask the interrupt line in the default implementation as we use a
lazy disable approach. That means we mark the interrupt disabled, but
leave the hardware unmasked. That's an optimization because we avoid
the hardware access for the common case where no interrupt happens
after we marked it disabled. If an interrupt happens, then the
interrupt flow handler masks the line at the hardware level and marks
it pending.

Suspend makes use of this delayed disable as it "disables" all
interrupts when preparing the suspend transition. Right before the
system goes into hardware suspend state it checks whether one of the
interrupts which is marked as a wakeup interrupt came in after
disabling it.

Most interrupt chips have a separate register which selects the
interrupts which can wake up the system from suspend, so we don't have
to mask any on the non wakeup interrupts.

But now we have to deal with brilliant designed hardware which lacks
such a wakeup configuration facility. For such hardware it's necessary
to mask all non wakeup interrupts before going into suspend in order
to avoid the wakeup from random interrupts.

Rather than working around this in the affected interrupt chip
implementations we can solve this elegant in the core code itself.

Add a flag IRQCHIP_MASK_ON_SUSPEND which can be set by the irq chip
implementation to indicate, that the interrupts which are not selected
as wakeup sources must be masked in the suspend path. Mask them in the
loop which checks the wakeup interrupts pending flag.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAbhijeet Dharmapurikar <adharmap@codeaurora.org>
LKML-Reference: <alpine.LFD.2.00.1103112112310.2787@localhost6.localdomain6>

Some irq_chips need to know the state of wakeup mode for
setting the trigger type etc. Reflect it in irq_data state.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

No users outside of core.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

No users outside of core.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Keep status in sync until all users are fixed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Xen needs to reenable interrupts which are marked IRQF_NO_SUSPEND in the
resume path. Add a flag to force the reenabling in the resume code.
Tested-and-acked-by: NIan Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.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>

The kerneldoc comment describing suspend_device_irqs() is currently
misleading, because generally the function doesn't really disable
interrupt lines at the chip level.  Replace it with a more accurate
one.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
LKML-Reference: <200907050022.35117.rjw@sisk.pl>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Introduce helper functions allowing us to prevent device drivers from
getting any interrupts (without disabling interrupts on the CPU)
during suspend (or hibernation) and to make them start to receive
interrupts again during the subsequent resume.  These functions make it
possible to keep timer interrupts enabled while the "late" suspend and
"early" resume callbacks provided by device drivers are being
executed.  In turn, this allows device drivers' "late" suspend and
"early" resume callbacks to sleep, execute ACPI callbacks etc.

The functions introduced here will be used to rework the handling of
interrupts during suspend (hibernation) and resume.  Namely,
interrupts will only be disabled on the CPU right before suspending
sysdevs, while device drivers will be prevented from receiving
interrupts, with the help of the new helper function, before their
"late" suspend callbacks run (and analogously during resume).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>