[rt] Refresh "genirq: Do not invoke the affinity callback via a workqueue on RT" for context changes in 4.19.114

debian/changelog

@@ -1622,6 +1622,8 @@ linux (4.19.115-1) UNRELEASED; urgency=medium
   * [rt] Refresh "workqueue: Use normal rcu" for context changes in 4.19.112
   * [rt] Refresh "signals: Allow rt tasks to cache one sigqueue struct" for
     context changes in 4.19.112
+  * [rt] Refresh "genirq: Do not invoke the affinity callback via a workqueue
+    on RT" for context changes in 4.19.114
 
   [ Ben Hutchings ]
   * [x86] Drop "Add a SysRq option to lift kernel lockdown" (Closes: #947021)

debian/patches-rt/0097-genirq-Do-not-invoke-the-affinity-callback-via-a-wor.patch

@@ -16,8 +16,6 @@ Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  kernel/irq/manage.c       | 46 ++++++++++++++++++++++++++++++++++++---
  2 files changed, 49 insertions(+), 3 deletions(-)
 
-diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
-index 315f852b4981..a943c07b54ba 100644
 --- a/include/linux/interrupt.h
 +++ b/include/linux/interrupt.h
 @@ -13,6 +13,7 @@
@@ -28,7 +26,7 @@ index 315f852b4981..a943c07b54ba 100644
  
  #include <linux/atomic.h>
  #include <asm/ptrace.h>
-@@ -225,6 +226,7 @@ extern void resume_device_irqs(void);
+@@ -225,6 +226,7 @@
   * struct irq_affinity_notify - context for notification of IRQ affinity changes
   * @irq:		Interrupt to which notification applies
   * @kref:		Reference count, for internal use
@@ -36,7 +34,7 @@ index 315f852b4981..a943c07b54ba 100644
   * @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);
+@@ -236,7 +238,11 @@
  struct irq_affinity_notify {
  	unsigned int irq;
  	struct kref kref;
@@ -48,24 +46,22 @@ index 315f852b4981..a943c07b54ba 100644
  	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 3c26d0708709..eadcbfbd434a 100644
 --- a/kernel/irq/manage.c
 +++ b/kernel/irq/manage.c
-@@ -285,7 +285,12 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
+@@ -285,7 +285,12 @@
  
  	if (desc->affinity_notify) {
  		kref_get(&desc->affinity_notify->kref);
 +
 +#ifdef CONFIG_PREEMPT_RT_BASE
-+		swork_queue(&desc->affinity_notify->swork);
++		if (!swork_queue(&desc->affinity_notify->swork)) {
 +#else
- 		schedule_work(&desc->affinity_notify->work);
+ 		if (!schedule_work(&desc->affinity_notify->work)) {
 +#endif
- 	}
- 	irqd_set(data, IRQD_AFFINITY_SET);
- 
-@@ -323,10 +328,8 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
+ 			/* Work was already scheduled, drop our extra ref */
+ 			kref_put(&desc->affinity_notify->kref,
+ 				 desc->affinity_notify->release);
+@@ -327,10 +332,8 @@
  }
  EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
  
@@ -77,7 +73,7 @@ index 3c26d0708709..eadcbfbd434a 100644
  	struct irq_desc *desc = irq_to_desc(notify->irq);
  	cpumask_var_t cpumask;
  	unsigned long flags;
-@@ -348,6 +351,35 @@ static void irq_affinity_notify(struct work_struct *work)
+@@ -352,6 +355,35 @@
  	kref_put(&notify->kref, notify->release);
  }
  
@@ -113,7 +109,7 @@ index 3c26d0708709..eadcbfbd434a 100644
  /**
   *	irq_set_affinity_notifier - control notification of IRQ affinity changes
   *	@irq:		Interrupt for which to enable/disable notification
-@@ -376,7 +408,12 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
+@@ -380,7 +412,12 @@
  	if (notify) {
  		notify->irq = irq;
  		kref_init(&notify->kref);
@@ -126,17 +122,17 @@ index 3c26d0708709..eadcbfbd434a 100644
  	}
  
  	raw_spin_lock_irqsave(&desc->lock, flags);
-@@ -385,7 +422,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
+@@ -389,10 +426,13 @@
  	raw_spin_unlock_irqrestore(&desc->lock, flags);
  
  	if (old_notify) {
 +#ifndef CONFIG_PREEMPT_RT_BASE
 +		/* Need to address this for PREEMPT_RT */
- 		cancel_work_sync(&old_notify->work);
+ 		if (cancel_work_sync(&old_notify->work)) {
+ 			/* Pending work had a ref, put that one too */
+ 			kref_put(&old_notify->kref, old_notify->release);
+ 		}
 +#endif
  		kref_put(&old_notify->kref, old_notify->release);
  	}
  
--- 
-2.25.1
-