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genirq: keep affinities set from userspace across free/request_irq()

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Impact: preserve user-modified affinities on interrupts

Kumar Galak noticed that commit
1840475676 (genirq: Expose default irq
affinity mask (take 3))

overrides an already set affinity setting across a free /
request_irq(). Happens e.g. with ifdown/ifup of a network device.

Change the logic to mark the affinities as set and keep them
intact. This also fixes the unlocked access to irq_desc in
irq_select_affinity() when called from irq_affinity_proc_write()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner
2008-11-07 13:18:30 +01:00
committed by Ingo Molnar
parent 8b805ef617
commit f6d87f4bd2
5 changed files with 53 additions and 28 deletions
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58
kernel/irq/manage.c
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@@ -82,24 +82,27 @@ int irq_can_set_affinity(unsigned int irq)
int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc->chip->set_affinity)
return -EINVAL;
spin_lock_irqsave(&desc->lock, flags);
#ifdef CONFIG_GENERIC_PENDING_IRQ
if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
unsigned long flags;
spin_lock_irqsave(&desc->lock, flags);
desc->affinity = cpumask;
desc->chip->set_affinity(irq, cpumask);
spin_unlock_irqrestore(&desc->lock, flags);
} else
set_pending_irq(irq, cpumask);
} else {
desc->status |= IRQ_MOVE_PENDING;
desc->pending_mask = cpumask;
}
#else
desc->affinity = cpumask;
desc->chip->set_affinity(irq, cpumask);
#endif
desc->status |= IRQ_AFFINITY_SET;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
@@ -107,24 +110,59 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
/*
* Generic version of the affinity autoselector.
*/
int irq_select_affinity(unsigned int irq)
int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
{
cpumask_t mask;
struct irq_desc *desc;
if (!irq_can_set_affinity(irq))
return 0;
cpus_and(mask, cpu_online_map, irq_default_affinity);
desc = irq_to_desc(irq);
/*
* Preserve an userspace affinity setup, but make sure that
* one of the targets is online.
*/
if (desc->status & IRQ_AFFINITY_SET) {
if (cpus_intersects(desc->affinity, cpu_online_map))
mask = desc->affinity;
else
desc->status &= ~IRQ_AFFINITY_SET;
}
desc->affinity = mask;
desc->chip->set_affinity(irq, mask);
return 0;
}
#else
static inline int do_irq_select_affinity(unsigned int irq, struct irq_desc *d)
{
return irq_select_affinity(irq);
}
#endif
/*
* Called when affinity is set via /proc/irq
*/
int irq_select_affinity_usr(unsigned int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
int ret;
spin_lock_irqsave(&desc->lock, flags);
ret = do_irq_select_affinity(irq, desc);
spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
#else
static inline int do_select_irq_affinity(int irq, struct irq_desc *desc)
{
return 0;
}
#endif
/**
@@ -446,7 +484,7 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
desc->depth = 1;
/* Set default affinity mask once everything is setup */
irq_select_affinity(irq);
do_irq_select_affinity(irq, desc);
} else if ((new->flags & IRQF_TRIGGER_MASK)
&& (new->flags & IRQF_TRIGGER_MASK)