forked from Minki/linux
77f85e66aa
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
124 lines
3.4 KiB
C
124 lines
3.4 KiB
C
/*
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* Generic cpu hotunplug interrupt migration code copied from the
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* arch/arm implementation
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*
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* Copyright (C) Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/interrupt.h>
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#include <linux/ratelimit.h>
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#include <linux/irq.h>
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#include "internals.h"
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static bool migrate_one_irq(struct irq_desc *desc)
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{
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struct irq_data *d = irq_desc_get_irq_data(desc);
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struct irq_chip *chip = irq_data_get_irq_chip(d);
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bool maskchip = !irq_can_move_pcntxt(d) && !irqd_irq_masked(d);
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const struct cpumask *affinity;
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bool brokeaff = false;
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int err;
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/*
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* IRQ chip might be already torn down, but the irq descriptor is
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* still in the radix tree. Also if the chip has no affinity setter,
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* nothing can be done here.
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*/
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if (!chip || !chip->irq_set_affinity) {
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pr_debug("IRQ %u: Unable to migrate away\n", d->irq);
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return false;
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}
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/*
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* No move required, if:
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* - Interrupt is per cpu
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* - Interrupt is not started
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* - Affinity mask does not include this CPU.
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*
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* Note: Do not check desc->action as this might be a chained
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* interrupt.
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*/
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affinity = irq_data_get_affinity_mask(d);
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if (irqd_is_per_cpu(d) || !irqd_is_started(d) ||
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!cpumask_test_cpu(smp_processor_id(), affinity)) {
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/*
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* If an irq move is pending, abort it if the dying CPU is
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* the sole target.
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*/
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irq_fixup_move_pending(desc, false);
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return false;
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}
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/*
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* Complete an eventually pending irq move cleanup. If this
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* interrupt was moved in hard irq context, then the vectors need
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* to be cleaned up. It can't wait until this interrupt actually
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* happens and this CPU was involved.
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*/
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irq_force_complete_move(desc);
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/*
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* If there is a setaffinity pending, then try to reuse the pending
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* mask, so the last change of the affinity does not get lost. If
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* there is no move pending or the pending mask does not contain
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* any online CPU, use the current affinity mask.
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*/
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if (irq_fixup_move_pending(desc, true))
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affinity = irq_desc_get_pending_mask(desc);
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/* Mask the chip for interrupts which cannot move in process context */
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if (maskchip && chip->irq_mask)
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chip->irq_mask(d);
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if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
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affinity = cpu_online_mask;
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brokeaff = true;
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}
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err = irq_do_set_affinity(d, affinity, true);
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if (err) {
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pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",
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d->irq, err);
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brokeaff = false;
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}
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if (maskchip && chip->irq_unmask)
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chip->irq_unmask(d);
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return brokeaff;
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}
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/**
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* irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu
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*
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* The current CPU has been marked offline. Migrate IRQs off this CPU.
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* If the affinity settings do not allow other CPUs, force them onto any
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* available CPU.
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*
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* Note: we must iterate over all IRQs, whether they have an attached
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* action structure or not, as we need to get chained interrupts too.
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*/
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void irq_migrate_all_off_this_cpu(void)
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{
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struct irq_desc *desc;
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unsigned int irq;
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for_each_active_irq(irq) {
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bool affinity_broken;
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desc = irq_to_desc(irq);
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raw_spin_lock(&desc->lock);
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affinity_broken = migrate_one_irq(desc);
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raw_spin_unlock(&desc->lock);
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if (affinity_broken) {
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pr_warn_ratelimited("IRQ %u: no longer affine to CPU%u\n",
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irq, smp_processor_id());
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}
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}
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}
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