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-rw-r--r--kernel/irq/Makefile1
-rw-r--r--kernel/irq/devres.c16
-rw-r--r--kernel/irq/handle.c58
-rw-r--r--kernel/irq/internals.h2
-rw-r--r--kernel/irq/manage.c225
-rw-r--r--kernel/irq/numa_migrate.c1
-rw-r--r--kernel/irq/pm.c79
7 files changed, 350 insertions, 32 deletions
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 4dd5b1e..3394f8f 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
obj-$(CONFIG_NUMA_MIGRATE_IRQ_DESC) += numa_migrate.o
+obj-$(CONFIG_PM_SLEEP) += pm.o
diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
index 38a25b8..d06df9c 100644
--- a/kernel/irq/devres.c
+++ b/kernel/irq/devres.c
@@ -26,10 +26,12 @@ static int devm_irq_match(struct device *dev, void *res, void *data)
}
/**
- * devm_request_irq - allocate an interrupt line for a managed device
+ * devm_request_threaded_irq - allocate an interrupt line for a managed device
* @dev: device to request interrupt for
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs
+ * @thread_fn: function to be called in a threaded interrupt context. NULL
+ * for devices which handle everything in @handler
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
@@ -42,9 +44,10 @@ static int devm_irq_match(struct device *dev, void *res, void *data)
* If an IRQ allocated with this function needs to be freed
* separately, dev_free_irq() must be used.
*/
-int devm_request_irq(struct device *dev, unsigned int irq,
- irq_handler_t handler, unsigned long irqflags,
- const char *devname, void *dev_id)
+int devm_request_threaded_irq(struct device *dev, unsigned int irq,
+ irq_handler_t handler, irq_handler_t thread_fn,
+ unsigned long irqflags, const char *devname,
+ void *dev_id)
{
struct irq_devres *dr;
int rc;
@@ -54,7 +57,8 @@ int devm_request_irq(struct device *dev, unsigned int irq,
if (!dr)
return -ENOMEM;
- rc = request_irq(irq, handler, irqflags, devname, dev_id);
+ rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
+ dev_id);
if (rc) {
devres_free(dr);
return rc;
@@ -66,7 +70,7 @@ int devm_request_irq(struct device *dev, unsigned int irq,
return 0;
}
-EXPORT_SYMBOL(devm_request_irq);
+EXPORT_SYMBOL(devm_request_threaded_irq);
/**
* devm_free_irq - free an interrupt
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 9ebf779..26e0875 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -17,6 +17,7 @@
#include <linux/kernel_stat.h>
#include <linux/rculist.h>
#include <linux/hash.h>
+#include <trace/irq.h>
#include <linux/bootmem.h>
#include "internals.h"
@@ -338,6 +339,18 @@ irqreturn_t no_action(int cpl, void *dev_id)
return IRQ_NONE;
}
+static void warn_no_thread(unsigned int irq, struct irqaction *action)
+{
+ if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags))
+ return;
+
+ printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD "
+ "but no thread function available.", irq, action->name);
+}
+
+DEFINE_TRACE(irq_handler_entry);
+DEFINE_TRACE(irq_handler_exit);
+
/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
@@ -350,15 +363,54 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
- WARN_ONCE(!in_irq(), "BUG: IRQ handler called from non-hardirq context!");
-
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
do {
+ trace_irq_handler_entry(irq, action);
ret = action->handler(irq, action->dev_id);
- if (ret == IRQ_HANDLED)
+ trace_irq_handler_exit(irq, action, ret);
+
+ switch (ret) {
+ case IRQ_WAKE_THREAD:
+ /*
+ * Set result to handled so the spurious check
+ * does not trigger.
+ */
+ ret = IRQ_HANDLED;
+
+ /*
+ * Catch drivers which return WAKE_THREAD but
+ * did not set up a thread function
+ */
+ if (unlikely(!action->thread_fn)) {
+ warn_no_thread(irq, action);
+ break;
+ }
+
+ /*
+ * Wake up the handler thread for this
+ * action. In case the thread crashed and was
+ * killed we just pretend that we handled the
+ * interrupt. The hardirq handler above has
+ * disabled the device interrupt, so no irq
+ * storm is lurking.
+ */
+ if (likely(!test_bit(IRQTF_DIED,
+ &action->thread_flags))) {
+ set_bit(IRQTF_RUNTHREAD, &action->thread_flags);
+ wake_up_process(action->thread);
+ }
+
+ /* Fall through to add to randomness */
+ case IRQ_HANDLED:
status |= action->flags;
+ break;
+
+ default:
+ break;
+ }
+
retval |= ret;
action = action->next;
} while (action);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index ee1aa9f..01ce20e 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -12,6 +12,8 @@ extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);
extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
unsigned long flags);
+extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
+extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
extern struct lock_class_key irq_desc_lock_class;
extern void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 6458e99..2734eca 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -8,16 +8,15 @@
*/
#include <linux/irq.h>
+#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
+#include <linux/sched.h>
#include "internals.h"
-#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
-cpumask_var_t irq_default_affinity;
-
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
@@ -53,9 +52,18 @@ void synchronize_irq(unsigned int irq)
/* Oops, that failed? */
} while (status & IRQ_INPROGRESS);
+
+ /*
+ * We made sure that no hardirq handler is running. Now verify
+ * that no threaded handlers are active.
+ */
+ wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
}
EXPORT_SYMBOL(synchronize_irq);
+#ifdef CONFIG_SMP
+cpumask_var_t irq_default_affinity;
+
/**
* irq_can_set_affinity - Check if the affinity of a given irq can be set
* @irq: Interrupt to check
@@ -72,6 +80,18 @@ int irq_can_set_affinity(unsigned int irq)
return 1;
}
+static void
+irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
+{
+ struct irqaction *action = desc->action;
+
+ while (action) {
+ if (action->thread)
+ set_cpus_allowed_ptr(action->thread, cpumask);
+ action = action->next;
+ }
+}
+
/**
* irq_set_affinity - Set the irq affinity of a given irq
* @irq: Interrupt to set affinity
@@ -89,10 +109,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
spin_lock_irqsave(&desc->lock, flags);
#ifdef CONFIG_GENERIC_PENDING_IRQ
- if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
- cpumask_copy(desc->affinity, cpumask);
+ if (desc->status & IRQ_MOVE_PCNTXT)
desc->chip->set_affinity(irq, cpumask);
- } else {
+ else {
desc->status |= IRQ_MOVE_PENDING;
cpumask_copy(desc->pending_mask, cpumask);
}
@@ -100,6 +119,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
cpumask_copy(desc->affinity, cpumask);
desc->chip->set_affinity(irq, cpumask);
#endif
+ irq_set_thread_affinity(desc, cpumask);
desc->status |= IRQ_AFFINITY_SET;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
@@ -150,6 +170,8 @@ int irq_select_affinity_usr(unsigned int irq)
spin_lock_irqsave(&desc->lock, flags);
ret = setup_affinity(irq, desc);
+ if (!ret)
+ irq_set_thread_affinity(desc, desc->affinity);
spin_unlock_irqrestore(&desc->lock, flags);
return ret;
@@ -162,6 +184,20 @@ static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
}
#endif
+void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
+{
+ if (suspend) {
+ if (!desc->action || (desc->action->flags & IRQF_TIMER))
+ return;
+ desc->status |= IRQ_SUSPENDED;
+ }
+
+ if (!desc->depth++) {
+ desc->status |= IRQ_DISABLED;
+ desc->chip->disable(irq);
+ }
+}
+
/**
* disable_irq_nosync - disable an irq without waiting
* @irq: Interrupt to disable
@@ -182,10 +218,7 @@ void disable_irq_nosync(unsigned int irq)
return;
spin_lock_irqsave(&desc->lock, flags);
- if (!desc->depth++) {
- desc->status |= IRQ_DISABLED;
- desc->chip->disable(irq);
- }
+ __disable_irq(desc, irq, false);
spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL(disable_irq_nosync);
@@ -215,15 +248,21 @@ void disable_irq(unsigned int irq)
}
EXPORT_SYMBOL(disable_irq);
-static void __enable_irq(struct irq_desc *desc, unsigned int irq)
+void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
{
+ if (resume)
+ desc->status &= ~IRQ_SUSPENDED;
+
switch (desc->depth) {
case 0:
+ err_out:
WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
break;
case 1: {
unsigned int status = desc->status & ~IRQ_DISABLED;
+ if (desc->status & IRQ_SUSPENDED)
+ goto err_out;
/* Prevent probing on this irq: */
desc->status = status | IRQ_NOPROBE;
check_irq_resend(desc, irq);
@@ -253,7 +292,7 @@ void enable_irq(unsigned int irq)
return;
spin_lock_irqsave(&desc->lock, flags);
- __enable_irq(desc, irq);
+ __enable_irq(desc, irq, false);
spin_unlock_irqrestore(&desc->lock, flags);
}
EXPORT_SYMBOL(enable_irq);
@@ -384,6 +423,90 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
return ret;
}
+static int irq_wait_for_interrupt(struct irqaction *action)
+{
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (test_and_clear_bit(IRQTF_RUNTHREAD,
+ &action->thread_flags)) {
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+ schedule();
+ }
+ return -1;
+}
+
+/*
+ * Interrupt handler thread
+ */
+static int irq_thread(void *data)
+{
+ struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
+ struct irqaction *action = data;
+ struct irq_desc *desc = irq_to_desc(action->irq);
+ int wake;
+
+ sched_setscheduler(current, SCHED_FIFO, &param);
+ current->irqaction = action;
+
+ while (!irq_wait_for_interrupt(action)) {
+
+ atomic_inc(&desc->threads_active);
+
+ spin_lock_irq(&desc->lock);
+ if (unlikely(desc->status & IRQ_DISABLED)) {
+ /*
+ * CHECKME: We might need a dedicated
+ * IRQ_THREAD_PENDING flag here, which
+ * retriggers the thread in check_irq_resend()
+ * but AFAICT IRQ_PENDING should be fine as it
+ * retriggers the interrupt itself --- tglx
+ */
+ desc->status |= IRQ_PENDING;
+ spin_unlock_irq(&desc->lock);
+ } else {
+ spin_unlock_irq(&desc->lock);
+
+ action->thread_fn(action->irq, action->dev_id);
+ }
+
+ wake = atomic_dec_and_test(&desc->threads_active);
+
+ if (wake && waitqueue_active(&desc->wait_for_threads))
+ wake_up(&desc->wait_for_threads);
+ }
+
+ /*
+ * Clear irqaction. Otherwise exit_irq_thread() would make
+ * fuzz about an active irq thread going into nirvana.
+ */
+ current->irqaction = NULL;
+ return 0;
+}
+
+/*
+ * Called from do_exit()
+ */
+void exit_irq_thread(void)
+{
+ struct task_struct *tsk = current;
+
+ if (!tsk->irqaction)
+ return;
+
+ printk(KERN_ERR
+ "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
+ tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
+
+ /*
+ * Set the THREAD DIED flag to prevent further wakeups of the
+ * soon to be gone threaded handler.
+ */
+ set_bit(IRQTF_DIED, &tsk->irqaction->flags);
+}
+
/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
@@ -420,6 +543,26 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
}
/*
+ * Threaded handler ?
+ */
+ if (new->thread_fn) {
+ struct task_struct *t;
+
+ t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
+ new->name);
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+ /*
+ * We keep the reference to the task struct even if
+ * the thread dies to avoid that the interrupt code
+ * references an already freed task_struct.
+ */
+ get_task_struct(t);
+ new->thread = t;
+ wake_up_process(t);
+ }
+
+ /*
* The following block of code has to be executed atomically
*/
spin_lock_irqsave(&desc->lock, flags);
@@ -456,15 +599,15 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
if (!shared) {
irq_chip_set_defaults(desc->chip);
+ init_waitqueue_head(&desc->wait_for_threads);
+
/* Setup the type (level, edge polarity) if configured: */
if (new->flags & IRQF_TRIGGER_MASK) {
ret = __irq_set_trigger(desc, irq,
new->flags & IRQF_TRIGGER_MASK);
- if (ret) {
- spin_unlock_irqrestore(&desc->lock, flags);
- return ret;
- }
+ if (ret)
+ goto out_thread;
} else
compat_irq_chip_set_default_handler(desc);
#if defined(CONFIG_IRQ_PER_CPU)
@@ -511,7 +654,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
*/
if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
desc->status &= ~IRQ_SPURIOUS_DISABLED;
- __enable_irq(desc, irq);
+ __enable_irq(desc, irq, false);
}
spin_unlock_irqrestore(&desc->lock, flags);
@@ -532,8 +675,19 @@ mismatch:
dump_stack();
}
#endif
+ ret = -EBUSY;
+
+out_thread:
spin_unlock_irqrestore(&desc->lock, flags);
- return -EBUSY;
+ if (new->thread) {
+ struct task_struct *t = new->thread;
+
+ new->thread = NULL;
+ if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
+ kthread_stop(t);
+ put_task_struct(t);
+ }
+ return ret;
}
/**
@@ -559,6 +713,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action, **action_ptr;
+ struct task_struct *irqthread;
unsigned long flags;
WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
@@ -605,6 +760,10 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
else
desc->chip->disable(irq);
}
+
+ irqthread = action->thread;
+ action->thread = NULL;
+
spin_unlock_irqrestore(&desc->lock, flags);
unregister_handler_proc(irq, action);
@@ -612,6 +771,12 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
/* Make sure it's not being used on another CPU: */
synchronize_irq(irq);
+ if (irqthread) {
+ if (!test_bit(IRQTF_DIED, &action->thread_flags))
+ kthread_stop(irqthread);
+ put_task_struct(irqthread);
+ }
+
#ifdef CONFIG_DEBUG_SHIRQ
/*
* It's a shared IRQ -- the driver ought to be prepared for an IRQ
@@ -664,9 +829,12 @@ void free_irq(unsigned int irq, void *dev_id)
EXPORT_SYMBOL(free_irq);
/**
- * request_irq - allocate an interrupt line
+ * request_threaded_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
- * @handler: Function to be called when the IRQ occurs
+ * @handler: Function to be called when the IRQ occurs.
+ * Primary handler for threaded interrupts
+ * @thread_fn: Function called from the irq handler thread
+ * If NULL, no irq thread is created
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
@@ -678,6 +846,15 @@ EXPORT_SYMBOL(free_irq);
* raises, you must take care both to initialise your hardware
* and to set up the interrupt handler in the right order.
*
+ * If you want to set up a threaded irq handler for your device
+ * then you need to supply @handler and @thread_fn. @handler ist
+ * still called in hard interrupt context and has to check
+ * whether the interrupt originates from the device. If yes it
+ * needs to disable the interrupt on the device and return
+ * IRQ_THREAD_WAKE which will wake up the handler thread and run
+ * @thread_fn. This split handler design is necessary to support
+ * shared interrupts.
+ *
* Dev_id must be globally unique. Normally the address of the
* device data structure is used as the cookie. Since the handler
* receives this value it makes sense to use it.
@@ -693,8 +870,9 @@ EXPORT_SYMBOL(free_irq);
* IRQF_TRIGGER_* Specify active edge(s) or level
*
*/
-int request_irq(unsigned int irq, irq_handler_t handler,
- unsigned long irqflags, const char *devname, void *dev_id)
+int request_threaded_irq(unsigned int irq, irq_handler_t handler,
+ irq_handler_t thread_fn, unsigned long irqflags,
+ const char *devname, void *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
@@ -742,6 +920,7 @@ int request_irq(unsigned int irq, irq_handler_t handler,
return -ENOMEM;
action->handler = handler;
+ action->thread_fn = thread_fn;
action->flags = irqflags;
action->name = devname;
action->dev_id = dev_id;
@@ -771,4 +950,4 @@ int request_irq(unsigned int irq, irq_handler_t handler,
#endif
return retval;
}
-EXPORT_SYMBOL(request_irq);
+EXPORT_SYMBOL(request_threaded_irq);
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index 243d612..44bbdcb 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -54,6 +54,7 @@ static bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
{
free_kstat_irqs(old_desc, desc);
+ free_desc_masks(old_desc, desc);
arch_free_chip_data(old_desc, desc);
}
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
new file mode 100644
index 0000000..638d8be
--- /dev/null
+++ b/kernel/irq/pm.c
@@ -0,0 +1,79 @@
+/*
+ * linux/kernel/irq/pm.c
+ *
+ * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file contains power management functions related to interrupts.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
+
+/**
+ * suspend_device_irqs - disable all currently enabled interrupt lines
+ *
+ * During system-wide suspend or hibernation device interrupts need to be
+ * disabled at the chip level and this function is provided for this purpose.
+ * It disables all interrupt lines that are enabled at the moment and sets the
+ * IRQ_SUSPENDED flag for them.
+ */
+void suspend_device_irqs(void)
+{
+ struct irq_desc *desc;
+ int irq;
+
+ for_each_irq_desc(irq, desc) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ __disable_irq(desc, irq, true);
+ spin_unlock_irqrestore(&desc->lock, flags);
+ }
+
+ for_each_irq_desc(irq, desc)
+ if (desc->status & IRQ_SUSPENDED)
+ synchronize_irq(irq);
+}
+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 IRQ_SUSPENDED flag set.
+ */
+void resume_device_irqs(void)
+{
+ struct irq_desc *desc;
+ int irq;
+
+ for_each_irq_desc(irq, desc) {
+ unsigned long flags;
+
+ if (!(desc->status & IRQ_SUSPENDED))
+ continue;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ __enable_irq(desc, irq, true);
+ spin_unlock_irqrestore(&desc->lock, flags);
+ }
+}
+EXPORT_SYMBOL_GPL(resume_device_irqs);
+
+/**
+ * check_wakeup_irqs - check if any wake-up interrupts are pending
+ */
+int check_wakeup_irqs(void)
+{
+ struct irq_desc *desc;
+ int irq;
+
+ for_each_irq_desc(irq, desc)
+ if ((desc->status & IRQ_WAKEUP) && (desc->status & IRQ_PENDING))
+ return -EBUSY;
+
+ return 0;
+}
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