tegrakernel/kernel/kernel-4.9/rt-patches/0195-genirq-Do-not-invoke-t...

153 lines
4.7 KiB
Diff

From 60e95a9fdc9b5283e0a076ba9b3b8ef3ee7abf81 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 21 Aug 2013 17:48:46 +0200
Subject: [PATCH 195/365] genirq: Do not invoke the affinity callback via a
workqueue on RT
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>
---
drivers/scsi/qla2xxx/qla_isr.c | 4 +++
include/linux/interrupt.h | 6 +++++
kernel/irq/manage.c | 49 ++++++++++++++++++++++++++++------
3 files changed, 51 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 17b1525d492b..6249c4b6f4be 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -3127,7 +3127,11 @@ qla24xx_enable_msix(struct qla_hw_data *ha, struct rsp_que *rsp)
* kref_put().
*/
kref_get(&qentry->irq_notify.kref);
+#ifdef CONFIG_PREEMPT_RT_BASE
+ swork_queue(&qentry->irq_notify.swork);
+#else
schedule_work(&qentry->irq_notify.work);
+#endif
}
/*
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 807d3f6af646..4917b6273f33 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -14,6 +14,7 @@
#include <linux/hrtimer.h>
#include <linux/kref.h>
#include <linux/workqueue.h>
+#include <linux/swork.h>
#include <linux/atomic.h>
#include <asm/ptrace.h>
@@ -219,6 +220,7 @@ 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.
@@ -230,7 +232,11 @@ 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);
};
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 996b5fb0efc4..8f459282b034 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -235,11 +235,12 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
- if (!schedule_work(&desc->affinity_notify->work)) {
- /* Work was already scheduled, drop our extra ref */
- kref_put(&desc->affinity_notify->kref,
- desc->affinity_notify->release);
- }
+
+#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);
@@ -277,10 +278,8 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
}
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;
@@ -302,6 +301,35 @@ static void irq_affinity_notify(struct work_struct *work)
kref_put(&notify->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
@@ -330,7 +358,12 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
if (notify) {
notify->irq = irq;
kref_init(&notify->kref);
+#ifdef CONFIG_PREEMPT_RT_BASE
+ INIT_SWORK(&notify->swork, irq_affinity_notify);
+ init_helper_thread();
+#else
INIT_WORK(&notify->work, irq_affinity_notify);
+#endif
}
raw_spin_lock_irqsave(&desc->lock, flags);
--
2.28.0