From 1dbfa187dad57d3e17207328ec8bd2d90b4177d2 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 23 Jan 2011 12:08:16 +0000 Subject: ARM: irq migration: force migration off CPU going down The force argument to irq_set_affinity really should be 'true' as moving IRQs off a CPU which is going down isn't optional. Acked-by: Thomas Gleixner Signed-off-by: Russell King --- arch/arm/kernel/irq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/kernel/irq.c') diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 28536e3..2f19aa5 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -185,7 +185,7 @@ static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu) raw_spin_lock_irq(&desc->lock); desc->irq_data.chip->irq_set_affinity(&desc->irq_data, - cpumask_of(cpu), false); + cpumask_of(cpu), true); raw_spin_unlock_irq(&desc->lock); } -- cgit v1.1 From 617912440bf20497d23d01ab58076998aced3f15 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 23 Jan 2011 12:09:36 +0000 Subject: ARM: irq migration: ensure migration is handled safely Ensure appropriate locks are taken to ensure that IRQ migration off the current CPU is race-free. We may have a concurrent set_affinity via procfs running on another CPU in parallel with the IRQ migration, resulting in unpredictable results. Signed-off-by: Russell King --- arch/arm/kernel/irq.c | 50 +++++++++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 19 deletions(-) (limited to 'arch/arm/kernel/irq.c') diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 2f19aa5..3535d37 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -179,14 +179,21 @@ int __init arch_probe_nr_irqs(void) #ifdef CONFIG_HOTPLUG_CPU -static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu) +static bool migrate_one_irq(struct irq_data *d) { - pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->irq_data.node, cpu); + unsigned int cpu = cpumask_any_and(d->affinity, cpu_online_mask); + bool ret = false; - raw_spin_lock_irq(&desc->lock); - desc->irq_data.chip->irq_set_affinity(&desc->irq_data, - cpumask_of(cpu), true); - raw_spin_unlock_irq(&desc->lock); + if (cpu >= nr_cpu_ids) { + cpu = cpumask_any(cpu_online_mask); + ret = true; + } + + pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", d->irq, d->node, cpu); + + d->chip->irq_set_affinity(d, cpumask_of(cpu), true); + + return ret; } /* @@ -198,25 +205,30 @@ void migrate_irqs(void) { unsigned int i, cpu = smp_processor_id(); struct irq_desc *desc; + unsigned long flags; + + local_irq_save(flags); for_each_irq_desc(i, desc) { struct irq_data *d = &desc->irq_data; + bool affinity_broken = false; - if (d->node == cpu) { - unsigned int newcpu = cpumask_any_and(d->affinity, - cpu_online_mask); - if (newcpu >= nr_cpu_ids) { - if (printk_ratelimit()) - printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n", - i, cpu); + raw_spin_lock(&desc->lock); + do { + if (desc->action == NULL) + break; - cpumask_setall(d->affinity); - newcpu = cpumask_any_and(d->affinity, - cpu_online_mask); - } + if (d->node != cpu) + break; - route_irq(desc, i, newcpu); - } + affinity_broken = migrate_one_irq(d); + } while (0); + raw_spin_unlock(&desc->lock); + + if (affinity_broken && printk_ratelimit()) + pr_warning("IRQ%u no longer affine to CPU%u\n", i, cpu); } + + local_irq_restore(flags); } #endif /* CONFIG_HOTPLUG_CPU */ -- cgit v1.1 From 1b7a2d90c83bec624ac89f0642cb57bed17a2d3d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 7 Feb 2011 22:30:49 +0100 Subject: arm: Use irq flag setter function Use the proper accessor function instead of fiddling in the status bits directly. Signed-off-by: Thomas Gleixner Cc: linux-arm-kernel@lists.infradead.org --- arch/arm/kernel/irq.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'arch/arm/kernel/irq.c') diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 3535d37..9b3a6d8 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -144,24 +144,21 @@ asm_do_IRQ(unsigned int irq, struct pt_regs *regs) void set_irq_flags(unsigned int irq, unsigned int iflags) { - struct irq_desc *desc; - unsigned long flags; + unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; if (irq >= nr_irqs) { printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq); return; } - desc = irq_to_desc(irq); - raw_spin_lock_irqsave(&desc->lock, flags); - desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; if (iflags & IRQF_VALID) - desc->status &= ~IRQ_NOREQUEST; + clr |= IRQ_NOREQUEST; if (iflags & IRQF_PROBE) - desc->status &= ~IRQ_NOPROBE; + clr |= IRQ_NOPROBE; if (!(iflags & IRQF_NOAUTOEN)) - desc->status &= ~IRQ_NOAUTOEN; - raw_spin_unlock_irqrestore(&desc->lock, flags); + clr |= IRQ_NOAUTOEN; + /* Order is clear bits in "clr" then set bits in "set" */ + irq_modify_status(irq, clr, set & ~clr); } void __init init_IRQ(void) -- cgit v1.1 From 25a5662a13e604d86b0a9fd71703582a7393d8ec Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 24 Mar 2011 12:02:11 +0100 Subject: arm: Use generic show_interrupts() Use the generic version and just keep the arch specific output. Signed-off-by: Thomas Gleixner --- arch/arm/kernel/irq.c | 55 +++++---------------------------------------------- 1 file changed, 5 insertions(+), 50 deletions(-) (limited to 'arch/arm/kernel/irq.c') diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 9b3a6d8..83bbad0 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -51,63 +51,18 @@ unsigned long irq_err_count; -int show_interrupts(struct seq_file *p, void *v) +int arch_show_interrupts(struct seq_file *p, int prec) { - int i = *(loff_t *) v, cpu; - struct irq_desc *desc; - struct irqaction * action; - unsigned long flags; - int prec, n; - - for (prec = 3, n = 1000; prec < 10 && n <= nr_irqs; prec++) - n *= 10; - -#ifdef CONFIG_SMP - if (prec < 4) - prec = 4; -#endif - - if (i == 0) { - char cpuname[12]; - - seq_printf(p, "%*s ", prec, ""); - for_each_present_cpu(cpu) { - sprintf(cpuname, "CPU%d", cpu); - seq_printf(p, " %10s", cpuname); - } - seq_putc(p, '\n'); - } - - if (i < nr_irqs) { - desc = irq_to_desc(i); - raw_spin_lock_irqsave(&desc->lock, flags); - action = desc->action; - if (!action) - goto unlock; - - seq_printf(p, "%*d: ", prec, i); - for_each_present_cpu(cpu) - seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu)); - seq_printf(p, " %10s", desc->irq_data.chip->name ? : "-"); - seq_printf(p, " %s", action->name); - for (action = action->next; action; action = action->next) - seq_printf(p, ", %s", action->name); - - seq_putc(p, '\n'); -unlock: - raw_spin_unlock_irqrestore(&desc->lock, flags); - } else if (i == nr_irqs) { #ifdef CONFIG_FIQ - show_fiq_list(p, prec); + show_fiq_list(p, prec); #endif #ifdef CONFIG_SMP - show_ipi_list(p, prec); + show_ipi_list(p, prec); #endif #ifdef CONFIG_LOCAL_TIMERS - show_local_irqs(p, prec); + show_local_irqs(p, prec); #endif - seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); - } + seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); return 0; } -- cgit v1.1