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Commit 3ddc14e2 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 

Pull ARM fixes from Russell King:
 "A few ARM fixes:

   - Dietmar Eggemann noticed an issue with IRQ migration during CPU
     hotplug stress testing.

   - Mathieu Desnoyers noticed that a previous fix broke optimised
     kprobes.

   - Robin Murphy noticed a case where we were not clearing the dma_ops"

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8835/1: dma-mapping: Clear DMA ops on teardown
  ARM: 8834/1: Fix: kprobes: optimized kprobes illegal instruction
  ARM: 8824/1: fix a migrating irq bug when hotplug cpu
parents 10f49021 fc67e6f1

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -1400,6 +1400,7 @@ config NR_CPUS 
config HOTPLUG_CPU

	bool "Support for hot-pluggable CPUs"

	depends on SMP

	select GENERIC_IRQ_MIGRATION

	help

	  Say Y here to experiment with turning CPUs off and on.  CPUs

	  can be controlled through /sys/devices/system/cpu.

arch/arm/include/asm/irq.h

+0 −1
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ 
#ifndef __ASSEMBLY__

struct irqaction;

struct pt_regs;

extern void migrate_irqs(void);



extern void asm_do_IRQ(unsigned int, struct pt_regs *);

void handle_IRQ(unsigned int, struct pt_regs *);

arch/arm/kernel/irq.c

+0 −62
Original line number Diff line number Diff line
@@ -31,7 +31,6 @@ 
#include <linux/smp.h>

#include <linux/init.h>

#include <linux/seq_file.h>

#include <linux/ratelimit.h>

#include <linux/errno.h>

#include <linux/list.h>

#include <linux/kallsyms.h>
@@ -109,64 +108,3 @@ int __init arch_probe_nr_irqs(void) 
	return nr_irqs;

}

#endif
 


#ifdef CONFIG_HOTPLUG_CPU

static bool migrate_one_irq(struct irq_desc *desc)

{

	struct irq_data *d = irq_desc_get_irq_data(desc);

	const struct cpumask *affinity = irq_data_get_affinity_mask(d);

	struct irq_chip *c;

	bool ret = false;



	/*

	 * If this is a per-CPU interrupt, or the affinity does not

	 * include this CPU, then we have nothing to do.

	 */

	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))

		return false;



	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {

		affinity = cpu_online_mask;

		ret = true;

	}



	c = irq_data_get_irq_chip(d);

	if (!c->irq_set_affinity)

		pr_debug("IRQ%u: unable to set affinity\n", d->irq);

	else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)

		cpumask_copy(irq_data_get_affinity_mask(d), affinity);



	return ret;

}



/*

 * The current CPU has been marked offline.  Migrate IRQs off this CPU.

 * If the affinity settings do not allow other CPUs, force them onto any

 * available CPU.

 *

 * Note: we must iterate over all IRQs, whether they have an attached

 * action structure or not, as we need to get chained interrupts too.

 */

void migrate_irqs(void)

{

	unsigned int i;

	struct irq_desc *desc;

	unsigned long flags;



	local_irq_save(flags);



	for_each_irq_desc(i, desc) {

		bool affinity_broken;



		raw_spin_lock(&desc->lock);

		affinity_broken = migrate_one_irq(desc);

		raw_spin_unlock(&desc->lock);



		if (affinity_broken)

			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",

				i, smp_processor_id());

	}



	local_irq_restore(flags);

}

#endif /* CONFIG_HOTPLUG_CPU */

arch/arm/kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -254,7 +254,7 @@ int __cpu_disable(void) 
	/*

	 * OK - migrate IRQs away from this CPU

	 */

	migrate_irqs();

	irq_migrate_all_off_this_cpu();



	/*

	 * Flush user cache and TLB mappings, and then remove this CPU

arch/arm/mm/dma-mapping.c

+2 −0
Original line number Diff line number Diff line
@@ -2390,4 +2390,6 @@ void arch_teardown_dma_ops(struct device *dev) 
		return;



	arm_teardown_iommu_dma_ops(dev);

	/* Let arch_setup_dma_ops() start again from scratch upon re-probe */

	set_dma_ops(dev, NULL);

}