Greg KH
2011-Nov-09 21:26 UTC
[Xen-devel] [089/262] genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ian Campbell <ian.campbell@citrix.com>
commit 9bab0b7fbaceec47d32db51cd9e59c82fb071f5a upstream.
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 676dc3cf5bc3 "xen: Use
IRQF_FORCE_RESUME".
Signed-off-by: Ian 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
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/xen/events.c | 2 -
include/linux/interrupt.h | 3 ++
kernel/irq/pm.c | 48 +++++++++++++++++++++++++++++++++++++++-------
3 files changed, 45 insertions(+), 8 deletions(-)
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -1026,7 +1026,7 @@ int bind_ipi_to_irqhandler(enum ipi_vect
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);
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -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)
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -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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