2 * linux/kernel/irq/manage.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
7 * This file contains driver APIs to the irq subsystem.
10 #include <linux/irq.h>
11 #include <linux/kthread.h>
12 #include <linux/module.h>
13 #include <linux/random.h>
14 #include <linux/interrupt.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
18 #include "internals.h"
21 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
22 * @irq: interrupt number to wait for
24 * This function waits for any pending IRQ handlers for this interrupt
25 * to complete before returning. If you use this function while
26 * holding a resource the IRQ handler may need you will deadlock.
28 * This function may be called - with care - from IRQ context.
30 void synchronize_irq(unsigned int irq
)
32 struct irq_desc
*desc
= irq_to_desc(irq
);
42 * Wait until we're out of the critical section. This might
43 * give the wrong answer due to the lack of memory barriers.
45 while (desc
->status
& IRQ_INPROGRESS
)
48 /* Ok, that indicated we're done: double-check carefully. */
49 raw_spin_lock_irqsave(&desc
->lock
, flags
);
50 status
= desc
->status
;
51 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
53 /* Oops, that failed? */
54 } while (status
& IRQ_INPROGRESS
);
57 * We made sure that no hardirq handler is running. Now verify
58 * that no threaded handlers are active.
60 wait_event(desc
->wait_for_threads
, !atomic_read(&desc
->threads_active
));
62 EXPORT_SYMBOL(synchronize_irq
);
65 cpumask_var_t irq_default_affinity
;
68 * irq_can_set_affinity - Check if the affinity of a given irq can be set
69 * @irq: Interrupt to check
72 int irq_can_set_affinity(unsigned int irq
)
74 struct irq_desc
*desc
= irq_to_desc(irq
);
76 if (CHECK_IRQ_PER_CPU(desc
->status
) || !desc
->irq_data
.chip
||
77 !desc
->irq_data
.chip
->irq_set_affinity
)
84 * irq_set_thread_affinity - Notify irq threads to adjust affinity
85 * @desc: irq descriptor which has affitnity changed
87 * We just set IRQTF_AFFINITY and delegate the affinity setting
88 * to the interrupt thread itself. We can not call
89 * set_cpus_allowed_ptr() here as we hold desc->lock and this
90 * code can be called from hard interrupt context.
92 void irq_set_thread_affinity(struct irq_desc
*desc
)
94 struct irqaction
*action
= desc
->action
;
98 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
99 action
= action
->next
;
104 * irq_set_affinity - Set the irq affinity of a given irq
105 * @irq: Interrupt to set affinity
109 int irq_set_affinity(unsigned int irq
, const struct cpumask
*cpumask
)
111 struct irq_desc
*desc
= irq_to_desc(irq
);
112 struct irq_chip
*chip
= desc
->irq_data
.chip
;
115 if (!chip
->irq_set_affinity
)
118 raw_spin_lock_irqsave(&desc
->lock
, flags
);
120 #ifdef CONFIG_GENERIC_PENDING_IRQ
121 if (desc
->status
& IRQ_MOVE_PCNTXT
) {
122 if (!chip
->irq_set_affinity(&desc
->irq_data
, cpumask
, false)) {
123 cpumask_copy(desc
->irq_data
.affinity
, cpumask
);
124 irq_set_thread_affinity(desc
);
128 desc
->status
|= IRQ_MOVE_PENDING
;
129 cpumask_copy(desc
->pending_mask
, cpumask
);
132 if (!chip
->irq_set_affinity(&desc
->irq_data
, cpumask
, false)) {
133 cpumask_copy(desc
->irq_data
.affinity
, cpumask
);
134 irq_set_thread_affinity(desc
);
137 if (desc
->affinity_notify
) {
138 kref_get(&desc
->affinity_notify
->kref
);
139 schedule_work(&desc
->affinity_notify
->work
);
141 desc
->status
|= IRQ_AFFINITY_SET
;
142 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
146 int irq_set_affinity_hint(unsigned int irq
, const struct cpumask
*m
)
148 struct irq_desc
*desc
= irq_to_desc(irq
);
154 raw_spin_lock_irqsave(&desc
->lock
, flags
);
155 desc
->affinity_hint
= m
;
156 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
160 EXPORT_SYMBOL_GPL(irq_set_affinity_hint
);
162 static void irq_affinity_notify(struct work_struct
*work
)
164 struct irq_affinity_notify
*notify
=
165 container_of(work
, struct irq_affinity_notify
, work
);
166 struct irq_desc
*desc
= irq_to_desc(notify
->irq
);
167 cpumask_var_t cpumask
;
173 if (!alloc_cpumask_var(&cpumask
, GFP_KERNEL
))
176 raw_spin_lock_irqsave(&desc
->lock
, flags
);
177 #ifdef CONFIG_GENERIC_PENDING_IRQ
178 if (desc
->status
& IRQ_MOVE_PENDING
)
179 cpumask_copy(cpumask
, desc
->pending_mask
);
182 cpumask_copy(cpumask
, desc
->irq_data
.affinity
);
183 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
185 notify
->notify(notify
, cpumask
);
187 free_cpumask_var(cpumask
);
189 kref_put(¬ify
->kref
, notify
->release
);
193 * irq_set_affinity_notifier - control notification of IRQ affinity changes
194 * @irq: Interrupt for which to enable/disable notification
195 * @notify: Context for notification, or %NULL to disable
196 * notification. Function pointers must be initialised;
197 * the other fields will be initialised by this function.
199 * Must be called in process context. Notification may only be enabled
200 * after the IRQ is allocated and must be disabled before the IRQ is
201 * freed using free_irq().
204 irq_set_affinity_notifier(unsigned int irq
, struct irq_affinity_notify
*notify
)
206 struct irq_desc
*desc
= irq_to_desc(irq
);
207 struct irq_affinity_notify
*old_notify
;
210 /* The release function is promised process context */
216 /* Complete initialisation of *notify */
219 kref_init(¬ify
->kref
);
220 INIT_WORK(¬ify
->work
, irq_affinity_notify
);
223 raw_spin_lock_irqsave(&desc
->lock
, flags
);
224 old_notify
= desc
->affinity_notify
;
225 desc
->affinity_notify
= notify
;
226 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
229 kref_put(&old_notify
->kref
, old_notify
->release
);
233 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier
);
235 #ifndef CONFIG_AUTO_IRQ_AFFINITY
237 * Generic version of the affinity autoselector.
239 static int setup_affinity(unsigned int irq
, struct irq_desc
*desc
)
241 if (!irq_can_set_affinity(irq
))
245 * Preserve an userspace affinity setup, but make sure that
246 * one of the targets is online.
248 if (desc
->status
& (IRQ_AFFINITY_SET
| IRQ_NO_BALANCING
)) {
249 if (cpumask_any_and(desc
->irq_data
.affinity
, cpu_online_mask
)
253 desc
->status
&= ~IRQ_AFFINITY_SET
;
256 cpumask_and(desc
->irq_data
.affinity
, cpu_online_mask
, irq_default_affinity
);
258 desc
->irq_data
.chip
->irq_set_affinity(&desc
->irq_data
, desc
->irq_data
.affinity
, false);
263 static inline int setup_affinity(unsigned int irq
, struct irq_desc
*d
)
265 return irq_select_affinity(irq
);
270 * Called when affinity is set via /proc/irq
272 int irq_select_affinity_usr(unsigned int irq
)
274 struct irq_desc
*desc
= irq_to_desc(irq
);
278 raw_spin_lock_irqsave(&desc
->lock
, flags
);
279 ret
= setup_affinity(irq
, desc
);
281 irq_set_thread_affinity(desc
);
282 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
288 static inline int setup_affinity(unsigned int irq
, struct irq_desc
*desc
)
294 void __disable_irq(struct irq_desc
*desc
, unsigned int irq
, bool suspend
)
297 if (!desc
->action
|| (desc
->action
->flags
& IRQF_NO_SUSPEND
))
299 desc
->status
|= IRQ_SUSPENDED
;
302 if (!desc
->depth
++) {
303 desc
->status
|= IRQ_DISABLED
;
304 desc
->irq_data
.chip
->irq_disable(&desc
->irq_data
);
309 * disable_irq_nosync - disable an irq without waiting
310 * @irq: Interrupt to disable
312 * Disable the selected interrupt line. Disables and Enables are
314 * Unlike disable_irq(), this function does not ensure existing
315 * instances of the IRQ handler have completed before returning.
317 * This function may be called from IRQ context.
319 void disable_irq_nosync(unsigned int irq
)
321 struct irq_desc
*desc
= irq_to_desc(irq
);
328 raw_spin_lock_irqsave(&desc
->lock
, flags
);
329 __disable_irq(desc
, irq
, false);
330 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
331 chip_bus_sync_unlock(desc
);
333 EXPORT_SYMBOL(disable_irq_nosync
);
336 * disable_irq - disable an irq and wait for completion
337 * @irq: Interrupt to disable
339 * Disable the selected interrupt line. Enables and Disables are
341 * This function waits for any pending IRQ handlers for this interrupt
342 * to complete before returning. If you use this function while
343 * holding a resource the IRQ handler may need you will deadlock.
345 * This function may be called - with care - from IRQ context.
347 void disable_irq(unsigned int irq
)
349 struct irq_desc
*desc
= irq_to_desc(irq
);
354 disable_irq_nosync(irq
);
356 synchronize_irq(irq
);
358 EXPORT_SYMBOL(disable_irq
);
360 void __enable_irq(struct irq_desc
*desc
, unsigned int irq
, bool resume
)
363 if (!(desc
->status
& IRQ_SUSPENDED
)) {
366 if (!(desc
->action
->flags
& IRQF_FORCE_RESUME
))
368 /* Pretend that it got disabled ! */
371 desc
->status
&= ~IRQ_SUSPENDED
;
374 switch (desc
->depth
) {
377 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n", irq
);
380 unsigned int status
= desc
->status
& ~IRQ_DISABLED
;
382 if (desc
->status
& IRQ_SUSPENDED
)
384 /* Prevent probing on this irq: */
385 desc
->status
= status
| IRQ_NOPROBE
;
386 check_irq_resend(desc
, irq
);
395 * enable_irq - enable handling of an irq
396 * @irq: Interrupt to enable
398 * Undoes the effect of one call to disable_irq(). If this
399 * matches the last disable, processing of interrupts on this
400 * IRQ line is re-enabled.
402 * This function may be called from IRQ context only when
403 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
405 void enable_irq(unsigned int irq
)
407 struct irq_desc
*desc
= irq_to_desc(irq
);
413 if (WARN(!desc
->irq_data
.chip
|| !desc
->irq_data
.chip
->irq_enable
,
414 KERN_ERR
"enable_irq before setup/request_irq: irq %u\n", irq
))
418 raw_spin_lock_irqsave(&desc
->lock
, flags
);
419 __enable_irq(desc
, irq
, false);
420 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
421 chip_bus_sync_unlock(desc
);
423 EXPORT_SYMBOL(enable_irq
);
425 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
427 struct irq_desc
*desc
= irq_to_desc(irq
);
430 if (desc
->irq_data
.chip
->irq_set_wake
)
431 ret
= desc
->irq_data
.chip
->irq_set_wake(&desc
->irq_data
, on
);
437 * irq_set_irq_wake - control irq power management wakeup
438 * @irq: interrupt to control
439 * @on: enable/disable power management wakeup
441 * Enable/disable power management wakeup mode, which is
442 * disabled by default. Enables and disables must match,
443 * just as they match for non-wakeup mode support.
445 * Wakeup mode lets this IRQ wake the system from sleep
446 * states like "suspend to RAM".
448 int irq_set_irq_wake(unsigned int irq
, unsigned int on
)
450 struct irq_desc
*desc
= irq_to_desc(irq
);
454 /* wakeup-capable irqs can be shared between drivers that
455 * don't need to have the same sleep mode behaviors.
458 raw_spin_lock_irqsave(&desc
->lock
, flags
);
460 if (desc
->wake_depth
++ == 0) {
461 ret
= set_irq_wake_real(irq
, on
);
463 desc
->wake_depth
= 0;
465 desc
->status
|= IRQ_WAKEUP
;
468 if (desc
->wake_depth
== 0) {
469 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
470 } else if (--desc
->wake_depth
== 0) {
471 ret
= set_irq_wake_real(irq
, on
);
473 desc
->wake_depth
= 1;
475 desc
->status
&= ~IRQ_WAKEUP
;
479 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
480 chip_bus_sync_unlock(desc
);
483 EXPORT_SYMBOL(irq_set_irq_wake
);
486 * Internal function that tells the architecture code whether a
487 * particular irq has been exclusively allocated or is available
490 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
492 struct irq_desc
*desc
= irq_to_desc(irq
);
493 struct irqaction
*action
;
499 if (desc
->status
& IRQ_NOREQUEST
)
502 raw_spin_lock_irqsave(&desc
->lock
, flags
);
503 action
= desc
->action
;
505 if (irqflags
& action
->flags
& IRQF_SHARED
)
508 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
513 void compat_irq_chip_set_default_handler(struct irq_desc
*desc
)
516 * If the architecture still has not overriden
517 * the flow handler then zap the default. This
518 * should catch incorrect flow-type setting.
520 if (desc
->handle_irq
== &handle_bad_irq
)
521 desc
->handle_irq
= NULL
;
524 int __irq_set_trigger(struct irq_desc
*desc
, unsigned int irq
,
528 struct irq_chip
*chip
= desc
->irq_data
.chip
;
530 if (!chip
|| !chip
->irq_set_type
) {
532 * IRQF_TRIGGER_* but the PIC does not support multiple
535 pr_debug("No set_type function for IRQ %d (%s)\n", irq
,
536 chip
? (chip
->name
? : "unknown") : "unknown");
540 /* caller masked out all except trigger mode flags */
541 ret
= chip
->irq_set_type(&desc
->irq_data
, flags
);
544 pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
545 flags
, irq
, chip
->irq_set_type
);
547 if (flags
& (IRQ_TYPE_LEVEL_LOW
| IRQ_TYPE_LEVEL_HIGH
))
549 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
550 desc
->status
&= ~(IRQ_LEVEL
| IRQ_TYPE_SENSE_MASK
);
551 desc
->status
|= flags
;
553 if (chip
!= desc
->irq_data
.chip
)
554 irq_chip_set_defaults(desc
->irq_data
.chip
);
561 * Default primary interrupt handler for threaded interrupts. Is
562 * assigned as primary handler when request_threaded_irq is called
563 * with handler == NULL. Useful for oneshot interrupts.
565 static irqreturn_t
irq_default_primary_handler(int irq
, void *dev_id
)
567 return IRQ_WAKE_THREAD
;
571 * Primary handler for nested threaded interrupts. Should never be
574 static irqreturn_t
irq_nested_primary_handler(int irq
, void *dev_id
)
576 WARN(1, "Primary handler called for nested irq %d\n", irq
);
580 static int irq_wait_for_interrupt(struct irqaction
*action
)
582 while (!kthread_should_stop()) {
583 set_current_state(TASK_INTERRUPTIBLE
);
585 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
586 &action
->thread_flags
)) {
587 __set_current_state(TASK_RUNNING
);
596 * Oneshot interrupts keep the irq line masked until the threaded
597 * handler finished. unmask if the interrupt has not been disabled and
600 static void irq_finalize_oneshot(unsigned int irq
, struct irq_desc
*desc
)
604 raw_spin_lock_irq(&desc
->lock
);
607 * Implausible though it may be we need to protect us against
608 * the following scenario:
610 * The thread is faster done than the hard interrupt handler
611 * on the other CPU. If we unmask the irq line then the
612 * interrupt can come in again and masks the line, leaves due
613 * to IRQ_INPROGRESS and the irq line is masked forever.
615 if (unlikely(desc
->status
& IRQ_INPROGRESS
)) {
616 raw_spin_unlock_irq(&desc
->lock
);
617 chip_bus_sync_unlock(desc
);
622 if (!(desc
->status
& IRQ_DISABLED
) && (desc
->status
& IRQ_MASKED
)) {
623 desc
->status
&= ~IRQ_MASKED
;
624 desc
->irq_data
.chip
->irq_unmask(&desc
->irq_data
);
626 raw_spin_unlock_irq(&desc
->lock
);
627 chip_bus_sync_unlock(desc
);
632 * Check whether we need to change the affinity of the interrupt thread.
635 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
)
639 if (!test_and_clear_bit(IRQTF_AFFINITY
, &action
->thread_flags
))
643 * In case we are out of memory we set IRQTF_AFFINITY again and
644 * try again next time
646 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
647 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
651 raw_spin_lock_irq(&desc
->lock
);
652 cpumask_copy(mask
, desc
->irq_data
.affinity
);
653 raw_spin_unlock_irq(&desc
->lock
);
655 set_cpus_allowed_ptr(current
, mask
);
656 free_cpumask_var(mask
);
660 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
) { }
664 * Interrupt handler thread
666 static int irq_thread(void *data
)
668 static const struct sched_param param
= {
669 .sched_priority
= MAX_USER_RT_PRIO
/2,
671 struct irqaction
*action
= data
;
672 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
673 int wake
, oneshot
= desc
->status
& IRQ_ONESHOT
;
675 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
676 current
->irqaction
= action
;
678 while (!irq_wait_for_interrupt(action
)) {
680 irq_thread_check_affinity(desc
, action
);
682 atomic_inc(&desc
->threads_active
);
684 raw_spin_lock_irq(&desc
->lock
);
685 if (unlikely(desc
->status
& IRQ_DISABLED
)) {
687 * CHECKME: We might need a dedicated
688 * IRQ_THREAD_PENDING flag here, which
689 * retriggers the thread in check_irq_resend()
690 * but AFAICT IRQ_PENDING should be fine as it
691 * retriggers the interrupt itself --- tglx
693 desc
->status
|= IRQ_PENDING
;
694 raw_spin_unlock_irq(&desc
->lock
);
696 raw_spin_unlock_irq(&desc
->lock
);
698 action
->thread_fn(action
->irq
, action
->dev_id
);
701 irq_finalize_oneshot(action
->irq
, desc
);
704 wake
= atomic_dec_and_test(&desc
->threads_active
);
706 if (wake
&& waitqueue_active(&desc
->wait_for_threads
))
707 wake_up(&desc
->wait_for_threads
);
711 * Clear irqaction. Otherwise exit_irq_thread() would make
712 * fuzz about an active irq thread going into nirvana.
714 current
->irqaction
= NULL
;
719 * Called from do_exit()
721 void exit_irq_thread(void)
723 struct task_struct
*tsk
= current
;
729 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
730 tsk
->comm
? tsk
->comm
: "", tsk
->pid
, tsk
->irqaction
->irq
);
733 * Set the THREAD DIED flag to prevent further wakeups of the
734 * soon to be gone threaded handler.
736 set_bit(IRQTF_DIED
, &tsk
->irqaction
->flags
);
740 * Internal function to register an irqaction - typically used to
741 * allocate special interrupts that are part of the architecture.
744 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
746 struct irqaction
*old
, **old_ptr
;
747 const char *old_name
= NULL
;
749 int nested
, shared
= 0;
755 if (desc
->irq_data
.chip
== &no_irq_chip
)
758 * Some drivers like serial.c use request_irq() heavily,
759 * so we have to be careful not to interfere with a
762 if (new->flags
& IRQF_SAMPLE_RANDOM
) {
764 * This function might sleep, we want to call it first,
765 * outside of the atomic block.
766 * Yes, this might clear the entropy pool if the wrong
767 * driver is attempted to be loaded, without actually
768 * installing a new handler, but is this really a problem,
769 * only the sysadmin is able to do this.
771 rand_initialize_irq(irq
);
774 /* Oneshot interrupts are not allowed with shared */
775 if ((new->flags
& IRQF_ONESHOT
) && (new->flags
& IRQF_SHARED
))
779 * Check whether the interrupt nests into another interrupt
782 nested
= desc
->status
& IRQ_NESTED_THREAD
;
787 * Replace the primary handler which was provided from
788 * the driver for non nested interrupt handling by the
789 * dummy function which warns when called.
791 new->handler
= irq_nested_primary_handler
;
795 * Create a handler thread when a thread function is supplied
796 * and the interrupt does not nest into another interrupt
799 if (new->thread_fn
&& !nested
) {
800 struct task_struct
*t
;
802 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
807 * We keep the reference to the task struct even if
808 * the thread dies to avoid that the interrupt code
809 * references an already freed task_struct.
816 * The following block of code has to be executed atomically
818 raw_spin_lock_irqsave(&desc
->lock
, flags
);
819 old_ptr
= &desc
->action
;
823 * Can't share interrupts unless both agree to and are
824 * the same type (level, edge, polarity). So both flag
825 * fields must have IRQF_SHARED set and the bits which
826 * set the trigger type must match.
828 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
829 ((old
->flags
^ new->flags
) & IRQF_TRIGGER_MASK
)) {
830 old_name
= old
->name
;
834 #if defined(CONFIG_IRQ_PER_CPU)
835 /* All handlers must agree on per-cpuness */
836 if ((old
->flags
& IRQF_PERCPU
) !=
837 (new->flags
& IRQF_PERCPU
))
841 /* add new interrupt at end of irq queue */
843 old_ptr
= &old
->next
;
850 irq_chip_set_defaults(desc
->irq_data
.chip
);
852 init_waitqueue_head(&desc
->wait_for_threads
);
854 /* Setup the type (level, edge polarity) if configured: */
855 if (new->flags
& IRQF_TRIGGER_MASK
) {
856 ret
= __irq_set_trigger(desc
, irq
,
857 new->flags
& IRQF_TRIGGER_MASK
);
862 compat_irq_chip_set_default_handler(desc
);
863 #if defined(CONFIG_IRQ_PER_CPU)
864 if (new->flags
& IRQF_PERCPU
)
865 desc
->status
|= IRQ_PER_CPU
;
868 desc
->status
&= ~(IRQ_AUTODETECT
| IRQ_WAITING
| IRQ_ONESHOT
|
869 IRQ_INPROGRESS
| IRQ_SPURIOUS_DISABLED
);
871 if (new->flags
& IRQF_ONESHOT
)
872 desc
->status
|= IRQ_ONESHOT
;
874 if (!(desc
->status
& IRQ_NOAUTOEN
)) {
876 desc
->status
&= ~IRQ_DISABLED
;
877 desc
->irq_data
.chip
->irq_startup(&desc
->irq_data
);
879 /* Undo nested disables: */
882 /* Exclude IRQ from balancing if requested */
883 if (new->flags
& IRQF_NOBALANCING
)
884 desc
->status
|= IRQ_NO_BALANCING
;
886 /* Set default affinity mask once everything is setup */
887 setup_affinity(irq
, desc
);
889 } else if ((new->flags
& IRQF_TRIGGER_MASK
)
890 && (new->flags
& IRQF_TRIGGER_MASK
)
891 != (desc
->status
& IRQ_TYPE_SENSE_MASK
)) {
892 /* hope the handler works with the actual trigger mode... */
893 pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
894 irq
, (int)(desc
->status
& IRQ_TYPE_SENSE_MASK
),
895 (int)(new->flags
& IRQF_TRIGGER_MASK
));
901 /* Reset broken irq detection when installing new handler */
903 desc
->irqs_unhandled
= 0;
906 * Check whether we disabled the irq via the spurious handler
907 * before. Reenable it and give it another chance.
909 if (shared
&& (desc
->status
& IRQ_SPURIOUS_DISABLED
)) {
910 desc
->status
&= ~IRQ_SPURIOUS_DISABLED
;
911 __enable_irq(desc
, irq
, false);
914 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
917 * Strictly no need to wake it up, but hung_task complains
918 * when no hard interrupt wakes the thread up.
921 wake_up_process(new->thread
);
923 register_irq_proc(irq
, desc
);
925 register_handler_proc(irq
, new);
930 #ifdef CONFIG_DEBUG_SHIRQ
931 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
932 printk(KERN_ERR
"IRQ handler type mismatch for IRQ %d\n", irq
);
934 printk(KERN_ERR
"current handler: %s\n", old_name
);
941 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
943 struct task_struct
*t
= new->thread
;
946 if (likely(!test_bit(IRQTF_DIED
, &new->thread_flags
)))
954 * setup_irq - setup an interrupt
955 * @irq: Interrupt line to setup
956 * @act: irqaction for the interrupt
958 * Used to statically setup interrupts in the early boot process.
960 int setup_irq(unsigned int irq
, struct irqaction
*act
)
963 struct irq_desc
*desc
= irq_to_desc(irq
);
966 retval
= __setup_irq(irq
, desc
, act
);
967 chip_bus_sync_unlock(desc
);
971 EXPORT_SYMBOL_GPL(setup_irq
);
974 * Internal function to unregister an irqaction - used to free
975 * regular and special interrupts that are part of the architecture.
977 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
979 struct irq_desc
*desc
= irq_to_desc(irq
);
980 struct irqaction
*action
, **action_ptr
;
983 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
988 raw_spin_lock_irqsave(&desc
->lock
, flags
);
991 * There can be multiple actions per IRQ descriptor, find the right
992 * one based on the dev_id:
994 action_ptr
= &desc
->action
;
996 action
= *action_ptr
;
999 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1000 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1005 if (action
->dev_id
== dev_id
)
1007 action_ptr
= &action
->next
;
1010 /* Found it - now remove it from the list of entries: */
1011 *action_ptr
= action
->next
;
1013 /* Currently used only by UML, might disappear one day: */
1014 #ifdef CONFIG_IRQ_RELEASE_METHOD
1015 if (desc
->irq_data
.chip
->release
)
1016 desc
->irq_data
.chip
->release(irq
, dev_id
);
1019 /* If this was the last handler, shut down the IRQ line: */
1020 if (!desc
->action
) {
1021 desc
->status
|= IRQ_DISABLED
;
1022 if (desc
->irq_data
.chip
->irq_shutdown
)
1023 desc
->irq_data
.chip
->irq_shutdown(&desc
->irq_data
);
1025 desc
->irq_data
.chip
->irq_disable(&desc
->irq_data
);
1029 /* make sure affinity_hint is cleaned up */
1030 if (WARN_ON_ONCE(desc
->affinity_hint
))
1031 desc
->affinity_hint
= NULL
;
1034 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1036 unregister_handler_proc(irq
, action
);
1038 /* Make sure it's not being used on another CPU: */
1039 synchronize_irq(irq
);
1041 #ifdef CONFIG_DEBUG_SHIRQ
1043 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1044 * event to happen even now it's being freed, so let's make sure that
1045 * is so by doing an extra call to the handler ....
1047 * ( We do this after actually deregistering it, to make sure that a
1048 * 'real' IRQ doesn't run in * parallel with our fake. )
1050 if (action
->flags
& IRQF_SHARED
) {
1051 local_irq_save(flags
);
1052 action
->handler(irq
, dev_id
);
1053 local_irq_restore(flags
);
1057 if (action
->thread
) {
1058 if (!test_bit(IRQTF_DIED
, &action
->thread_flags
))
1059 kthread_stop(action
->thread
);
1060 put_task_struct(action
->thread
);
1067 * remove_irq - free an interrupt
1068 * @irq: Interrupt line to free
1069 * @act: irqaction for the interrupt
1071 * Used to remove interrupts statically setup by the early boot process.
1073 void remove_irq(unsigned int irq
, struct irqaction
*act
)
1075 __free_irq(irq
, act
->dev_id
);
1077 EXPORT_SYMBOL_GPL(remove_irq
);
1080 * free_irq - free an interrupt allocated with request_irq
1081 * @irq: Interrupt line to free
1082 * @dev_id: Device identity to free
1084 * Remove an interrupt handler. The handler is removed and if the
1085 * interrupt line is no longer in use by any driver it is disabled.
1086 * On a shared IRQ the caller must ensure the interrupt is disabled
1087 * on the card it drives before calling this function. The function
1088 * does not return until any executing interrupts for this IRQ
1091 * This function must not be called from interrupt context.
1093 void free_irq(unsigned int irq
, void *dev_id
)
1095 struct irq_desc
*desc
= irq_to_desc(irq
);
1101 if (WARN_ON(desc
->affinity_notify
))
1102 desc
->affinity_notify
= NULL
;
1105 chip_bus_lock(desc
);
1106 kfree(__free_irq(irq
, dev_id
));
1107 chip_bus_sync_unlock(desc
);
1109 EXPORT_SYMBOL(free_irq
);
1112 * request_threaded_irq - allocate an interrupt line
1113 * @irq: Interrupt line to allocate
1114 * @handler: Function to be called when the IRQ occurs.
1115 * Primary handler for threaded interrupts
1116 * If NULL and thread_fn != NULL the default
1117 * primary handler is installed
1118 * @thread_fn: Function called from the irq handler thread
1119 * If NULL, no irq thread is created
1120 * @irqflags: Interrupt type flags
1121 * @devname: An ascii name for the claiming device
1122 * @dev_id: A cookie passed back to the handler function
1124 * This call allocates interrupt resources and enables the
1125 * interrupt line and IRQ handling. From the point this
1126 * call is made your handler function may be invoked. Since
1127 * your handler function must clear any interrupt the board
1128 * raises, you must take care both to initialise your hardware
1129 * and to set up the interrupt handler in the right order.
1131 * If you want to set up a threaded irq handler for your device
1132 * then you need to supply @handler and @thread_fn. @handler ist
1133 * still called in hard interrupt context and has to check
1134 * whether the interrupt originates from the device. If yes it
1135 * needs to disable the interrupt on the device and return
1136 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1137 * @thread_fn. This split handler design is necessary to support
1138 * shared interrupts.
1140 * Dev_id must be globally unique. Normally the address of the
1141 * device data structure is used as the cookie. Since the handler
1142 * receives this value it makes sense to use it.
1144 * If your interrupt is shared you must pass a non NULL dev_id
1145 * as this is required when freeing the interrupt.
1149 * IRQF_SHARED Interrupt is shared
1150 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
1151 * IRQF_TRIGGER_* Specify active edge(s) or level
1154 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
1155 irq_handler_t thread_fn
, unsigned long irqflags
,
1156 const char *devname
, void *dev_id
)
1158 struct irqaction
*action
;
1159 struct irq_desc
*desc
;
1163 * Sanity-check: shared interrupts must pass in a real dev-ID,
1164 * otherwise we'll have trouble later trying to figure out
1165 * which interrupt is which (messes up the interrupt freeing
1168 if ((irqflags
& IRQF_SHARED
) && !dev_id
)
1171 desc
= irq_to_desc(irq
);
1175 if (desc
->status
& IRQ_NOREQUEST
)
1181 handler
= irq_default_primary_handler
;
1184 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1188 action
->handler
= handler
;
1189 action
->thread_fn
= thread_fn
;
1190 action
->flags
= irqflags
;
1191 action
->name
= devname
;
1192 action
->dev_id
= dev_id
;
1194 chip_bus_lock(desc
);
1195 retval
= __setup_irq(irq
, desc
, action
);
1196 chip_bus_sync_unlock(desc
);
1201 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1202 if (!retval
&& (irqflags
& IRQF_SHARED
)) {
1204 * It's a shared IRQ -- the driver ought to be prepared for it
1205 * to happen immediately, so let's make sure....
1206 * We disable the irq to make sure that a 'real' IRQ doesn't
1207 * run in parallel with our fake.
1209 unsigned long flags
;
1212 local_irq_save(flags
);
1214 handler(irq
, dev_id
);
1216 local_irq_restore(flags
);
1222 EXPORT_SYMBOL(request_threaded_irq
);
1225 * request_any_context_irq - allocate an interrupt line
1226 * @irq: Interrupt line to allocate
1227 * @handler: Function to be called when the IRQ occurs.
1228 * Threaded handler for threaded interrupts.
1229 * @flags: Interrupt type flags
1230 * @name: An ascii name for the claiming device
1231 * @dev_id: A cookie passed back to the handler function
1233 * This call allocates interrupt resources and enables the
1234 * interrupt line and IRQ handling. It selects either a
1235 * hardirq or threaded handling method depending on the
1238 * On failure, it returns a negative value. On success,
1239 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1241 int request_any_context_irq(unsigned int irq
, irq_handler_t handler
,
1242 unsigned long flags
, const char *name
, void *dev_id
)
1244 struct irq_desc
*desc
= irq_to_desc(irq
);
1250 if (desc
->status
& IRQ_NESTED_THREAD
) {
1251 ret
= request_threaded_irq(irq
, NULL
, handler
,
1252 flags
, name
, dev_id
);
1253 return !ret
? IRQC_IS_NESTED
: ret
;
1256 ret
= request_irq(irq
, handler
, flags
, name
, dev_id
);
1257 return !ret
? IRQC_IS_HARDIRQ
: ret
;
1259 EXPORT_SYMBOL_GPL(request_any_context_irq
);