Commit c80081b9 authored by Daniel Lezcano's avatar Daniel Lezcano Committed by Thomas Gleixner
Browse files

genirq: Allow to pass the IRQF_TIMER flag with percpu irq request 



The irq timings infrastructure tracks when interrupts occur in order to
statistically predict te next interrupt event.

There is no point to track timer interrupts and try to predict them because
the next expiration time is already known. This can be avoided via the
IRQF_TIMER flag which is passed by timer drivers in request_irq(). It marks
the interrupt as timer based which alloes to ignore these interrupts in the
timings code.

Per CPU interrupts which are requested via request_percpu_+irq() have no
flag argument, so marking per cpu timer interrupts is not possible and they
get tracked pointlessly.

Add __request_percpu_irq() as a variant of request_percpu_irq() with a
flags argument and make request_percpu_irq() an inline wrapper passing
flags = 0.

The flag parameter is restricted to IRQF_TIMER as all other IRQF_ flags
make no sense for per cpu interrupts.

The next step is to convert all existing users of request_percpu_irq() and
then remove the wrapper and the underscores.

[ tglx: Massaged changelog ]

Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: nicolas.pitre@linaro.org
Cc: vincent.guittot@linaro.org
Cc: rafael@kernel.org
Link: http://lkml.kernel.org/r/1499344144-3964-1-git-send-email-daniel.lezcano@linaro.org
parent 2343877f

include/linux/interrupt.h

+10 −1
Original line number Diff line number Diff line
@@ -152,8 +152,17 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler, 
			unsigned long flags, const char *name, void *dev_id);



extern int __must_check

__request_percpu_irq(unsigned int irq, irq_handler_t handler,

		     unsigned long flags, const char *devname,

		     void __percpu *percpu_dev_id);



static inline int __must_check

request_percpu_irq(unsigned int irq, irq_handler_t handler,

		   const char *devname, void __percpu *percpu_dev_id);

		   const char *devname, void __percpu *percpu_dev_id)

{

	return __request_percpu_irq(irq, handler, 0,

				    devname, percpu_dev_id);

}



extern const void *free_irq(unsigned int, void *);

extern void free_percpu_irq(unsigned int, void __percpu *);

kernel/irq/manage.c

+10 −5
Original line number Diff line number Diff line
@@ -1950,9 +1950,10 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act) 
}



/**

 *	request_percpu_irq - allocate a percpu interrupt line

 *	__request_percpu_irq - allocate a percpu interrupt line

 *	@irq: Interrupt line to allocate

 *	@handler: Function to be called when the IRQ occurs.

 *	@flags: Interrupt type flags (IRQF_TIMER only)

 *	@devname: An ascii name for the claiming device

 *	@dev_id: A percpu cookie passed back to the handler function

 *
@@ -1965,8 +1966,9 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act) 
 *	the handler gets called with the interrupted CPU's instance of

 *	that variable.

 */

int request_percpu_irq(unsigned int irq, irq_handler_t handler,

		       const char *devname, void __percpu *dev_id)

int __request_percpu_irq(unsigned int irq, irq_handler_t handler,

			 unsigned long flags, const char *devname,

			 void __percpu *dev_id)

{

	struct irqaction *action;

	struct irq_desc *desc;
@@ -1980,12 +1982,15 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler, 
	    !irq_settings_is_per_cpu_devid(desc))

		return -EINVAL;



	if (flags && flags != IRQF_TIMER)

		return -EINVAL;



	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);

	if (!action)

		return -ENOMEM;



	action->handler = handler;

	action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;

	action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;

	action->name = devname;

	action->percpu_dev_id = dev_id;
@@ -2004,7 +2009,7 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler, 


	return retval;

}

EXPORT_SYMBOL_GPL(request_percpu_irq);

EXPORT_SYMBOL_GPL(__request_percpu_irq);



/**

 *	irq_get_irqchip_state - returns the irqchip state of a interrupt.

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