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Commit 222df54f authored by Marc Zyngier's avatar Marc Zyngier Committed by Thomas Gleixner
Browse files

genirq: Allow the affinity of a percpu interrupt to be set/retrieved 



In order to prepare the genirq layer for the concept of partitionned
percpu interrupts, let's allow an affinity to be associated with
such an interrupt. We introduce:

- irq_set_percpu_devid_partition: flag an interrupt as a percpu-devid
  interrupt, and associate it with an affinity
- irq_get_percpu_devid_partition: allow the affinity of that interrupt
  to be retrieved.

This will allow a driver to discover which CPUs the per-cpu interrupt
can actually fire on.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/1460365075-7316-3-git-send-email-marc.zyngier@arm.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 651e8b54

include/linux/irq.h

+4 −0
Original line number Diff line number Diff line
@@ -530,6 +530,10 @@ static inline void irq_set_chip_and_handler(unsigned int irq, struct irq_chip *c 
}



extern int irq_set_percpu_devid(unsigned int irq);

extern int irq_set_percpu_devid_partition(unsigned int irq,

					  const struct cpumask *affinity);

extern int irq_get_percpu_devid_partition(unsigned int irq,

					  struct cpumask *affinity);



extern void

__irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,

include/linux/irqdesc.h

+1 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ struct irq_desc { 
	int			threads_handled_last;

	raw_spinlock_t		lock;

	struct cpumask		*percpu_enabled;

	const struct cpumask	*percpu_affinity;

#ifdef CONFIG_SMP

	const struct cpumask	*affinity_hint;

	struct irq_affinity_notify *affinity_notify;

kernel/irq/irqdesc.c

+25 −1
Original line number Diff line number Diff line
@@ -595,7 +595,8 @@ void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus) 
		chip_bus_sync_unlock(desc);

}



int irq_set_percpu_devid(unsigned int irq)

int irq_set_percpu_devid_partition(unsigned int irq,

				   const struct cpumask *affinity)

{

	struct irq_desc *desc = irq_to_desc(irq);
@@ -610,10 +611,33 @@ int irq_set_percpu_devid(unsigned int irq) 
	if (!desc->percpu_enabled)

		return -ENOMEM;



	if (affinity)

		desc->percpu_affinity = affinity;

	else

		desc->percpu_affinity = cpu_possible_mask;



	irq_set_percpu_devid_flags(irq);

	return 0;

}



int irq_set_percpu_devid(unsigned int irq)

{

	return irq_set_percpu_devid_partition(irq, NULL);

}



int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)

{

	struct irq_desc *desc = irq_to_desc(irq);



	if (!desc || !desc->percpu_enabled)

		return -EINVAL;



	if (affinity)

		cpumask_copy(affinity, desc->percpu_affinity);



	return 0;

}



void kstat_incr_irq_this_cpu(unsigned int irq)

{

	kstat_incr_irqs_this_cpu(irq_to_desc(irq));