f6d87f4bd2
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>
65 lines
1.3 KiB
C
65 lines
1.3 KiB
C
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#include <linux/irq.h>
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void move_masked_irq(int irq)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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cpumask_t tmp;
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if (likely(!(desc->status & IRQ_MOVE_PENDING)))
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return;
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/*
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* Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
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*/
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if (CHECK_IRQ_PER_CPU(desc->status)) {
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WARN_ON(1);
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return;
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}
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desc->status &= ~IRQ_MOVE_PENDING;
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if (unlikely(cpus_empty(desc->pending_mask)))
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return;
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if (!desc->chip->set_affinity)
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return;
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assert_spin_locked(&desc->lock);
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cpus_and(tmp, desc->pending_mask, cpu_online_map);
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/*
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* If there was a valid mask to work with, please
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* do the disable, re-program, enable sequence.
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* This is *not* particularly important for level triggered
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* but in a edge trigger case, we might be setting rte
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* when an active trigger is comming in. This could
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* cause some ioapics to mal-function.
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* Being paranoid i guess!
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*
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* For correct operation this depends on the caller
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* masking the irqs.
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*/
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if (likely(!cpus_empty(tmp))) {
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desc->chip->set_affinity(irq,tmp);
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}
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cpus_clear(desc->pending_mask);
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}
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void move_native_irq(int irq)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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if (likely(!(desc->status & IRQ_MOVE_PENDING)))
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return;
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if (unlikely(desc->status & IRQ_DISABLED))
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return;
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desc->chip->mask(irq);
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move_masked_irq(irq);
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desc->chip->unmask(irq);
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}
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