Commit 328a4978 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

genirq: Add a new IRQCHIP_EOI_THREADED flag 



The flag is necessary for interrupt chips which require an ACK/EOI
after the handler has run. In case of threaded handlers this needs to
happen after the threaded handler has completed before the unmask of
the interrupt.

The flag is only unseful in combination with the handle_fasteoi_irq
flow control handler.

It can be combined with the flag IRQCHIP_EOI_IF_HANDLED, so the EOI is
not issued when the interrupt is disabled or in progress.

Tested-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-sunxi@googlegroups.com
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/1394733834-26839-2-git-send-email-hdegoede@redhat.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 4f6e4f71

include/linux/irq.h

+2 −0
Original line number Diff line number Diff line
@@ -356,6 +356,7 @@ struct irq_chip { 
 *				when irq enabled

 * IRQCHIP_SKIP_SET_WAKE:	Skip chip.irq_set_wake(), for this irq chip

 * IRQCHIP_ONESHOT_SAFE:	One shot does not require mask/unmask

 * IRQCHIP_EOI_THREADED:	Chip requires eoi() on unmask in threaded mode

 */

enum {

	IRQCHIP_SET_TYPE_MASKED		= (1 <<  0),
@@ -364,6 +365,7 @@ enum { 
	IRQCHIP_ONOFFLINE_ENABLED	= (1 <<  3),

	IRQCHIP_SKIP_SET_WAKE		= (1 <<  4),

	IRQCHIP_ONESHOT_SAFE		= (1 <<  5),

	IRQCHIP_EOI_THREADED		= (1 <<  6),

};



/* This include will go away once we isolated irq_desc usage to core code */

kernel/irq/chip.c

+40 −8
Original line number Diff line number Diff line
@@ -281,6 +281,19 @@ void unmask_irq(struct irq_desc *desc) 
	}

}



void unmask_threaded_irq(struct irq_desc *desc)

{

	struct irq_chip *chip = desc->irq_data.chip;



	if (chip->flags & IRQCHIP_EOI_THREADED)

		chip->irq_eoi(&desc->irq_data);



	if (chip->irq_unmask) {

		chip->irq_unmask(&desc->irq_data);

		irq_state_clr_masked(desc);

	}

}



/*

 *	handle_nested_irq - Handle a nested irq from a irq thread

 *	@irq:	the interrupt number
@@ -435,6 +448,27 @@ static inline void preflow_handler(struct irq_desc *desc) 
static inline void preflow_handler(struct irq_desc *desc) { }

#endif



static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)

{

	if (!(desc->istate & IRQS_ONESHOT)) {

		chip->irq_eoi(&desc->irq_data);

		return;

	}

	/*

	 * We need to unmask in the following cases:

	 * - Oneshot irq which did not wake the thread (caused by a

	 *   spurious interrupt or a primary handler handling it

	 *   completely).

	 */

	if (!irqd_irq_disabled(&desc->irq_data) &&

	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {

		chip->irq_eoi(&desc->irq_data);

		unmask_irq(desc);

	} else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {

		chip->irq_eoi(&desc->irq_data);

	}

}



/**

 *	handle_fasteoi_irq - irq handler for transparent controllers

 *	@irq:	the interrupt number
@@ -448,6 +482,8 @@ static inline void preflow_handler(struct irq_desc *desc) { } 
void

handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)

{

	struct irq_chip *chip = desc->irq_data.chip;



	raw_spin_lock(&desc->lock);



	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
@@ -473,18 +509,14 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) 
	preflow_handler(desc);

	handle_irq_event(desc);



	if (desc->istate & IRQS_ONESHOT)

		cond_unmask_irq(desc);

	cond_unmask_eoi_irq(desc, chip);



out_eoi:

	desc->irq_data.chip->irq_eoi(&desc->irq_data);

out_unlock:

	raw_spin_unlock(&desc->lock);

	return;

out:

	if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))

		goto out_eoi;

	goto out_unlock;

	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))

		chip->irq_eoi(&desc->irq_data);

	raw_spin_unlock(&desc->lock);

}



/**

kernel/irq/internals.h

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ extern void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu); 
extern void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu);

extern void mask_irq(struct irq_desc *desc);

extern void unmask_irq(struct irq_desc *desc);

extern void unmask_threaded_irq(struct irq_desc *desc);



extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);

kernel/irq/manage.c

+1 −1
Original line number Diff line number Diff line
@@ -748,7 +748,7 @@ again: 


	if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&

	    irqd_irq_masked(&desc->irq_data))

		unmask_irq(desc);

		unmask_threaded_irq(desc);



out_unlock:

	raw_spin_unlock_irq(&desc->lock);

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