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* genirq/cpuhotplug: Avoid irq affinity setting for single targetsThomas Gleixner2017-06-221-2/+10
| | | | | | | | | | | | | | | | Avoid trying to add a newly online CPU to the effective affinity mask of an started up interrupt. That interrupt will either stay on the already online CPU or move around for no value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235447.431321047@linutronix.de
* genirq/cpuhotplug: Handle managed IRQs on CPU hotplugThomas Gleixner2017-06-221-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a CPU goes offline, interrupts affine to the CPU are moved away. If the outgoing CPU is the last CPU in the affinity mask the migration code breaks the affinity and sets it it all online cpus. This is a problem for affinity managed interrupts as CPU hotplug is often used for power management purposes. If the affinity is broken, the interrupt is not longer affine to the CPUs to which it was allocated. The affinity spreading allows to lay out multi queue devices in a way that they are assigned to a single CPU or a group of CPUs. If the last CPU goes offline, then the queue is not longer used, so the interrupt can be shutdown gracefully and parked until one of the assigned CPUs comes online again. Add a graceful shutdown mechanism into the irq affinity breaking code path, mark the irq as MANAGED_SHUTDOWN and leave the affinity mask unmodified. In the online path, scan the active interrupts for managed interrupts and if the interrupt is functional and the newly online CPU is part of the affinity mask, restart the interrupt if it is marked MANAGED_SHUTDOWN or if the interrupts is started up, try to add the CPU back to the effective affinity mask. Originally-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170619235447.273417334@linutronix.de
* genirq/cpuhotplug: Use effective affinity maskThomas Gleixner2017-06-221-3/+11
| | | | | | | | | | | | | | | | | | | | If the architecture supports the effective affinity mask, migrating interrupts away which are not targeted by the effective mask is pointless. They can stay in the user or system supplied affinity mask, but won't be targetted at any given point as the affinity setter functions need to validate against the online cpu mask anyway. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235446.328488490@linutronix.de
* genirq/cpuhotplug: Set force affinity flag on hotplug migrationThomas Gleixner2017-06-221-1/+1
| | | | | | | | | | | | | | | Set the force migration flag when migrating interrupts away from an outgoing CPU. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.681874648@linutronix.de
* genirq/cpuhotplug: Add support for conditional maskingThomas Gleixner2017-06-221-1/+10
| | | | | | | | | | | | | | | | | | Interrupts which cannot be migrated in process context, need to be masked before the affinity is changed forcefully. Add support for that. Will be compiled out for architectures which do not have this x86 specific issue. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.604565591@linutronix.de
* genirq/cpuhotplug: Add support for cleaning up move in progressThomas Gleixner2017-06-221-2/+26
| | | | | | | | | | | | | | | | | | In order to move x86 to the generic hotplug migration code, add support for cleaning up move in progress bits. On architectures which have this x86 specific (mis)feature not enabled, this is optimized out by the compiler. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.525817311@linutronix.de
* genirq/cpuhotplug: Do not migrated shutdown irqsThomas Gleixner2017-06-221-3/+8
| | | | | | | | | | | | | | | | Interrupts, which are shut down are tried to be migrated as well. That's pointless because the interrupt cannot fire and the next startup will move it to the proper place anyway. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.447550992@linutronix.de
* genirq/cpuhotplug: Reorder check logicThomas Gleixner2017-06-221-16/+20
| | | | | | | | | | | | | | | | Move the checks for a valid irq chip and the irq_set_affinity() callback right in front of the whole migration logic. No point in doing a gazillion of other things when the interrupt cannot be migrated at all. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.354181630@linutronix.de
* genirq/cpuhotplug: Dont claim success on errorThomas Gleixner2017-06-221-1/+4
| | | | | | | | | | | | | | | | | | | | In case the affinity of an interrupt was broken, a printk is emitted. But if the affinity cannot be set at all due to a missing irq_set_affinity() callback or due to a failing callback, the message is still printed preceeded by a warning/error. That makes no sense whatsoever. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.274852976@linutronix.de
* genirq/cpuhotplug: Remove irq disabling logicThomas Gleixner2017-06-221-8/+4
| | | | | | | | | | | | | | | This is called from stop_machine() with interrupts disabled. No point in disabling them some more. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Keith Busch <keith.busch@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/20170619235445.198042748@linutronix.de
* genirq: Make the cpuhotplug migration code less noisyThomas Gleixner2015-10-221-1/+1
| | | | | | | | | | | | | | | | | | The original arm code has a pr_debug() statement for the case where the irq chip has no set_affinity() callback. That's sufficient for debugging and we really don't want to spam dmesg with useless warnings for the normal case. Fixes: f1e0bb0ad473: "genirq: Introduce generic irq migration for cpu hotunplug" Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Requested-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Jiang Liu <jiang.liu@linux.intel.com>
* genirq: Introduce generic irq migration for cpu hotunplugYang Yingliang2015-10-011-0/+82
ARM and ARM64 have almost identical code for migrating interrupts on cpu hotunplug. Provide a generic version which can be used by both. The new code addresses a shortcoming in the ARM[64] variants which fails to update the affinity change in some cases. The solution for this is to use the core function irq_do_set_affinity() instead of open coding it. [ tglx: Added copyright notice and license boilerplate. Rewrote subject and changelog. ] Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Acked-by: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: <linux-arm-kernel@lists.infradead.org> Link: http://lkml.kernel.org/r/1443087135-17044-2-git-send-email-yangyingliang@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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