Commit 9bab0b7f authored by Ian Campbell's avatar Ian Campbell Committed by Thomas Gleixner
Browse files

genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier 



This adds a mechanism to resume selected IRQs during syscore_resume
instead of dpm_resume_noirq.

Under Xen we need to resume IRQs associated with IPIs early enough
that the resched IPI is unmasked and we can therefore schedule
ourselves out of the stop_machine where the suspend/resume takes
place.

This issue was introduced by 676dc3cf "xen: Use IRQF_FORCE_RESUME".

Signed-off-by: default avatarIan Campbell <ian.campbell@citrix.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk


Cc: stable@kernel.org (at least to 2.6.32.y)
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 32cffdde

drivers/xen/events.c

+1 −1
Original line number Diff line number Diff line
@@ -1021,7 +1021,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi, 
	if (irq < 0)

		return irq;



	irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;

	irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;

	retval = request_irq(irq, handler, irqflags, devname, dev_id);

	if (retval != 0) {

		unbind_from_irq(irq);

include/linux/interrupt.h

+3 −0
Original line number Diff line number Diff line
@@ -59,6 +59,8 @@ 
 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend

 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set

 * IRQF_NO_THREAD - Interrupt cannot be threaded

 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device

 *                resume time.

 */

#define IRQF_DISABLED		0x00000020

#define IRQF_SAMPLE_RANDOM	0x00000040
@@ -72,6 +74,7 @@ 
#define IRQF_NO_SUSPEND		0x00004000

#define IRQF_FORCE_RESUME	0x00008000

#define IRQF_NO_THREAD		0x00010000

#define IRQF_EARLY_RESUME	0x00020000



#define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)

kernel/irq/pm.c

+41 −7
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/irq.h>

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/syscore_ops.h>



#include "internals.h"
@@ -39,25 +40,58 @@ void suspend_device_irqs(void) 
}

EXPORT_SYMBOL_GPL(suspend_device_irqs);



/**

 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()

 *

 * Enable all interrupt lines previously disabled by suspend_device_irqs() that

 * have the IRQS_SUSPENDED flag set.

 */

void resume_device_irqs(void)

static void resume_irqs(bool want_early)

{

	struct irq_desc *desc;

	int irq;



	for_each_irq_desc(irq, desc) {

		unsigned long flags;

		bool is_early = desc->action &&

			desc->action->flags & IRQF_EARLY_RESUME;



		if (is_early != want_early)

			continue;



		raw_spin_lock_irqsave(&desc->lock, flags);

		__enable_irq(desc, irq, true);

		raw_spin_unlock_irqrestore(&desc->lock, flags);

	}

}



/**

 * irq_pm_syscore_ops - enable interrupt lines early

 *

 * Enable all interrupt lines with %IRQF_EARLY_RESUME set.

 */

static void irq_pm_syscore_resume(void)

{

	resume_irqs(true);

}



static struct syscore_ops irq_pm_syscore_ops = {

	.resume		= irq_pm_syscore_resume,

};



static int __init irq_pm_init_ops(void)

{

	register_syscore_ops(&irq_pm_syscore_ops);

	return 0;

}



device_initcall(irq_pm_init_ops);



/**

 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()

 *

 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously

 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag

 * set as well as those with %IRQF_FORCE_RESUME.

 */

void resume_device_irqs(void)

{

	resume_irqs(false);

}

EXPORT_SYMBOL_GPL(resume_device_irqs);



/**

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