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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 21 Aug 2013 17:48:46 +0200
Subject: genirq: Do not invoke the affinity callback via a workqueue on RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.10-rt8.tar.xz
Joe Korty reported, that __irq_set_affinity_locked() schedules a
workqueue while holding a rawlock which results in a might_sleep()
warning.
This patch uses swork_queue() instead.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/interrupt.h | 6 ++++++
kernel/irq/manage.c | 43 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 46 insertions(+), 3 deletions(-)
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -13,6 +13,7 @@
#include <linux/hrtimer.h>
#include <linux/kref.h>
#include <linux/workqueue.h>
+#include <linux/swork.h>
#include <linux/atomic.h>
#include <asm/ptrace.h>
@@ -225,6 +226,7 @@ extern void resume_device_irqs(void);
* struct irq_affinity_notify - context for notification of IRQ affinity changes
* @irq: Interrupt to which notification applies
* @kref: Reference count, for internal use
+ * @swork: Swork item, for internal use
* @work: Work item, for internal use
* @notify: Function to be called on change. This will be
* called in process context.
@@ -236,7 +238,11 @@ extern void resume_device_irqs(void);
struct irq_affinity_notify {
unsigned int irq;
struct kref kref;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct swork_event swork;
+#else
struct work_struct work;
+#endif
void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
void (*release)(struct kref *ref);
};
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -259,7 +259,12 @@ int irq_set_affinity_locked(struct irq_d
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+ swork_queue(&desc->affinity_notify->swork);
+#else
schedule_work(&desc->affinity_notify->work);
+#endif
}
irqd_set(data, IRQD_AFFINITY_SET);
@@ -297,10 +302,8 @@ int irq_set_affinity_hint(unsigned int i
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
-static void irq_affinity_notify(struct work_struct *work)
+static void _irq_affinity_notify(struct irq_affinity_notify *notify)
{
- struct irq_affinity_notify *notify =
- container_of(work, struct irq_affinity_notify, work);
struct irq_desc *desc = irq_to_desc(notify->irq);
cpumask_var_t cpumask;
unsigned long flags;
@@ -322,6 +325,35 @@ static void irq_affinity_notify(struct w
kref_put(¬ify->kref, notify->release);
}
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void init_helper_thread(void)
+{
+ static int init_sworker_once;
+
+ if (init_sworker_once)
+ return;
+ if (WARN_ON(swork_get()))
+ return;
+ init_sworker_once = 1;
+}
+
+static void irq_affinity_notify(struct swork_event *swork)
+{
+ struct irq_affinity_notify *notify =
+ container_of(swork, struct irq_affinity_notify, swork);
+ _irq_affinity_notify(notify);
+}
+
+#else
+
+static void irq_affinity_notify(struct work_struct *work)
+{
+ struct irq_affinity_notify *notify =
+ container_of(work, struct irq_affinity_notify, work);
+ _irq_affinity_notify(notify);
+}
+#endif
+
/**
* irq_set_affinity_notifier - control notification of IRQ affinity changes
* @irq: Interrupt for which to enable/disable notification
@@ -350,7 +382,12 @@ irq_set_affinity_notifier(unsigned int i
if (notify) {
notify->irq = irq;
kref_init(¬ify->kref);
+#ifdef CONFIG_PREEMPT_RT_BASE
+ INIT_SWORK(¬ify->swork, irq_affinity_notify);
+ init_helper_thread();
+#else
INIT_WORK(¬ify->work, irq_affinity_notify);
+#endif
}
raw_spin_lock_irqsave(&desc->lock, flags);
|
