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2015-03-04genirq / PM: Add flag for shared NO_SUSPEND interrupt linesRafael J. Wysocki1-1/+6
It currently is required that all users of NO_SUSPEND interrupt lines pass the IRQF_NO_SUSPEND flag when requesting the IRQ or the WARN_ON_ONCE() in irq_pm_install_action() will trigger. That is done to warn about situations in which unprepared interrupt handlers may be run unnecessarily for suspended devices and may attempt to access those devices by mistake. However, it may cause drivers that have no technical reasons for using IRQF_NO_SUSPEND to set that flag just because they happen to share the interrupt line with something like a timer. Moreover, the generic handling of wakeup interrupts introduced by commit 9ce7a25849e8 (genirq: Simplify wakeup mechanism) only works for IRQs without any NO_SUSPEND users, so the drivers of wakeup devices needing to use shared NO_SUSPEND interrupt lines for signaling system wakeup generally have to detect wakeup in their interrupt handlers. Thus if they happen to share an interrupt line with a NO_SUSPEND user, they also need to request that their interrupt handlers be run after suspend_device_irqs(). In both cases the reason for using IRQF_NO_SUSPEND is not because the driver in question has a genuine need to run its interrupt handler after suspend_device_irqs(), but because it happens to share the line with some other NO_SUSPEND user. Otherwise, the driver would do without IRQF_NO_SUSPEND just fine. To make it possible to specify that condition explicitly, introduce a new IRQ action handler flag for shared IRQs, IRQF_COND_SUSPEND, that, when set, will indicate to the IRQ core that the interrupt user is generally fine with suspending the IRQ, but it also can tolerate handler invocations after suspend_device_irqs() and, in particular, it is capable of detecting system wakeup and triggering it as appropriate from its interrupt handler. That will allow us to work around a problem with a shared timer interrupt line on at91 platforms. Link: http://marc.info/?l=linux-kernel&m=142252777602084&w=2 Link: http://marc.info/?t=142252775300011&r=1&w=2 Link: https://lkml.org/lkml/2014/12/15/552 Reported-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com>
2014-09-01genirq: Simplify wakeup mechanismThomas Gleixner1-26/+29
Currently we suspend wakeup interrupts by lazy disabling them and check later whether the interrupt has fired, but that's not sufficient for suspend to idle as there is no way to check that once we transitioned into the CPU idle state. So we change the mechanism in the following way: 1) Leave the wakeup interrupts enabled across suspend 2) Add a check to irq_may_run() which is called at the beginning of each flow handler whether the interrupt is an armed wakeup source. This check is basically free as it just extends the existing check for IRQD_IRQ_INPROGRESS. So no new conditional in the hot path. If the IRQD_WAKEUP_ARMED flag is set, then the interrupt is disabled, marked as pending/suspended and the pm core is notified about the wakeup event. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ rjw: syscore.c and put irq_pm_check_wakeup() into pm.c ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01genirq: Mark wakeup sources as armed on suspendThomas Gleixner1-0/+5
This allows us to utilize this information in the irq_may_run() check without adding another conditional to the fast path. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01genirq: Avoid double loop on suspendThomas Gleixner1-6/+7
We can synchronize the suspended interrupts right away. No need for an extra loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01genirq: Move MASK_ON_SUSPEND handling into suspend_device_irqs()Thomas Gleixner1-12/+9
There is no reason why we should delay the masking of interrupts whose interrupt chip requests MASK_ON_SUSPEND to the point where we check the wakeup interrupts. We can do it right at the point where we mark the interrupt as suspended. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01genirq: Make use of pm misfeature accountingThomas Gleixner1-6/+3
Use the accounting fields which got introduced for snity checking for the various PM options. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01genirq: Add sanity checks for PM options on shared interrupt linesThomas Gleixner1-0/+36
Account the IRQF_NO_SUSPEND and IRQF_RESUME_EARLY actions on shared interrupt lines and yell loudly if there is a mismatch. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01genirq: Move suspend/resume logic into irq/pm codeThomas Gleixner1-6/+38
No functional change. Preparatory patch for cleaning up the suspend abort functionality. Update the comments while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-25irq: Enable all irqs unconditionally in irq_resumeLaxman Dewangan1-1/+1
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: Laxman Dewangan <ldewangan@nvidia.com> Acked-by-and-tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Pavel 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.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-05-04genirq: Do not consider disabled wakeup irqsThomas Gleixner1-1/+6
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: Thomas Gleixner <tglx@linutronix.de> Cc: NeilBrown <neilb@suse.de>
2011-10-17genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlierIan Campbell1-7/+41
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". 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 Cc: stable@kernel.org (at least to 2.6.32.y) Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-12genirq: Add chip flag to force mask on suspendThomas Gleixner1-4/+18
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: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org> LKML-Reference: <alpine.LFD.2.00.1103112112310.2787@localhost6.localdomain6>
2011-02-19genirq: Move wakeup state to irq_dataThomas Gleixner1-1/+1
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: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Move IRQ_WAKEUP to coreThomas Gleixner1-1/+1
No users outside of core. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Move IRQ_SUSPENDED to coreThomas Gleixner1-3/+3
No users outside of core. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19genirq: Move IRQ_PENDING flag to coreThomas Gleixner1-1/+2
Keep status in sync until all users are fixed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-08genirq: Add IRQF_FORCE_RESUMEThomas Gleixner1-3/+0
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: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-14genirq: Convert irq_desc.lock to raw_spinlockThomas Gleixner1-4/+4
Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-07-05genirq: Fix comment describing suspend_device_irqs()Rafael J. Wysocki1-4/+4
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: Rafael J. Wysocki <rjw@sisk.pl> LKML-Reference: <200907050022.35117.rjw@sisk.pl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-03-30PM: Introduce functions for suspending and resuming device interruptsRafael J. Wysocki1-0/+79
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: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Ingo Molnar <mingo@elte.hu>