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authorThomas Gleixner <tglx@linutronix.de>2014-02-15 00:55:19 +0000
committerThomas Gleixner <tglx@linutronix.de>2014-02-19 17:22:44 +0100
commita92444c6b2225a9115d661c950cb48a22aeace20 (patch)
treead76dd71c9fec1648469009cb356351ca23daef0
parent18258f7239a61d8929b8e0c7b6d46c446459074c (diff)
downloadlinux-a92444c6b2225a9115d661c950cb48a22aeace20.tar.bz2
genirq: Provide irq_wake_thread()
In course of the sdhci/sdio discussion with Russell about killing the sdio kthread hackery we discovered the need to be able to wake an interrupt thread from software. The rationale for this is, that sdio hardware can lack proper interrupt support for certain features. So the driver needs to poll the status registers, but at the same time it needs to be woken up by an hardware interrupt. To be able to get rid of the home brewn kthread construct of sdio we need a way to wake an irq thread independent of an actual hardware interrupt. Provide an irq_wake_thread() function which wakes up the thread which is associated to a given dev_id. This allows sdio to invoke the irq thread from the hardware irq handler via the IRQ_WAKE_THREAD return value and provides a possibility to wake it via a timer for the polling scenarios. That allows to simplify the sdio logic significantly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Chris Ball <chris@printf.net> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de
-rw-r--r--include/linux/interrupt.h1
-rw-r--r--kernel/irq/handle.c4
-rw-r--r--kernel/irq/internals.h1
-rw-r--r--kernel/irq/manage.c27
4 files changed, 31 insertions, 2 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index a2678d35b5a2..c7bfac1c4a7b 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -188,6 +188,7 @@ extern void disable_irq(unsigned int irq);
extern void disable_percpu_irq(unsigned int irq);
extern void enable_irq(unsigned int irq);
extern void enable_percpu_irq(unsigned int irq, unsigned int type);
+extern void irq_wake_thread(unsigned int irq, void *dev_id);
/* The following three functions are for the core kernel use only. */
extern void suspend_device_irqs(void);
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 131ca176b497..bfec453557b4 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -51,7 +51,7 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action)
"but no thread function available.", irq, action->name);
}
-static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
+void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
{
/*
* In case the thread crashed and was killed we just pretend that
@@ -157,7 +157,7 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
break;
}
- irq_wake_thread(desc, action);
+ __irq_wake_thread(desc, action);
/* Fall through to add to randomness */
case IRQ_HANDLED:
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 001fa5bab490..d61ac29e32d0 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -82,6 +82,7 @@ irqreturn_t handle_irq_event(struct irq_desc *desc);
/* Resending of interrupts :*/
void check_irq_resend(struct irq_desc *desc, unsigned int irq);
bool irq_wait_for_poll(struct irq_desc *desc);
+void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action);
#ifdef CONFIG_PROC_FS
extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 274ba9238fb7..54eb5c99351b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -911,6 +911,33 @@ static int irq_thread(void *data)
return 0;
}
+/**
+ * irq_wake_thread - wake the irq thread for the action identified by dev_id
+ * @irq: Interrupt line
+ * @dev_id: Device identity for which the thread should be woken
+ *
+ */
+void irq_wake_thread(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *action;
+ unsigned long flags;
+
+ if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+ return;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ for (action = desc->action; action; action = action->next) {
+ if (action->dev_id == dev_id) {
+ if (action->thread)
+ __irq_wake_thread(desc, action);
+ break;
+ }
+ }
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL_GPL(irq_wake_thread);
+
static void irq_setup_forced_threading(struct irqaction *new)
{
if (!force_irqthreads)