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
->istate
& IRQS_INPROGRESS
)
48 /* Ok, that indicated we're done: double-check carefully. */
49 raw_spin_lock_irqsave(&desc
->lock
, flags
);
51 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
53 /* Oops, that failed? */
54 } while (state
& IRQS_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 (!desc
|| !irqd_can_balance(&desc
->irq_data
) ||
77 !desc
->irq_data
.chip
|| !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
;
103 #ifdef CONFIG_GENERIC_PENDING_IRQ
104 static inline bool irq_can_move_pcntxt(struct irq_desc
*desc
)
106 return irq_settings_can_move_pcntxt(desc
);
108 static inline bool irq_move_pending(struct irq_desc
*desc
)
110 return irqd_is_setaffinity_pending(&desc
->irq_data
);
113 irq_copy_pending(struct irq_desc
*desc
, const struct cpumask
*mask
)
115 cpumask_copy(desc
->pending_mask
, mask
);
118 irq_get_pending(struct cpumask
*mask
, struct irq_desc
*desc
)
120 cpumask_copy(mask
, desc
->pending_mask
);
123 static inline bool irq_can_move_pcntxt(struct irq_desc
*desc
) { return true; }
124 static inline bool irq_move_pending(struct irq_desc
*desc
) { return false; }
126 irq_copy_pending(struct irq_desc
*desc
, const struct cpumask
*mask
) { }
128 irq_get_pending(struct cpumask
*mask
, struct irq_desc
*desc
) { }
132 * irq_set_affinity - Set the irq affinity of a given irq
133 * @irq: Interrupt to set affinity
137 int irq_set_affinity(unsigned int irq
, const struct cpumask
*mask
)
139 struct irq_desc
*desc
= irq_to_desc(irq
);
140 struct irq_chip
*chip
= desc
->irq_data
.chip
;
144 if (!chip
->irq_set_affinity
)
147 raw_spin_lock_irqsave(&desc
->lock
, flags
);
149 if (irq_can_move_pcntxt(desc
)) {
150 ret
= chip
->irq_set_affinity(&desc
->irq_data
, mask
, false);
152 case IRQ_SET_MASK_OK
:
153 cpumask_copy(desc
->irq_data
.affinity
, mask
);
154 case IRQ_SET_MASK_OK_NOCOPY
:
155 irq_set_thread_affinity(desc
);
159 irqd_set_move_pending(&desc
->irq_data
);
160 irq_copy_pending(desc
, mask
);
163 if (desc
->affinity_notify
) {
164 kref_get(&desc
->affinity_notify
->kref
);
165 schedule_work(&desc
->affinity_notify
->work
);
167 irq_compat_set_affinity(desc
);
168 irqd_set(&desc
->irq_data
, IRQD_AFFINITY_SET
);
169 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
173 int irq_set_affinity_hint(unsigned int irq
, const struct cpumask
*m
)
176 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
);
180 desc
->affinity_hint
= m
;
181 irq_put_desc_unlock(desc
, flags
);
184 EXPORT_SYMBOL_GPL(irq_set_affinity_hint
);
186 static void irq_affinity_notify(struct work_struct
*work
)
188 struct irq_affinity_notify
*notify
=
189 container_of(work
, struct irq_affinity_notify
, work
);
190 struct irq_desc
*desc
= irq_to_desc(notify
->irq
);
191 cpumask_var_t cpumask
;
194 if (!desc
|| !alloc_cpumask_var(&cpumask
, GFP_KERNEL
))
197 raw_spin_lock_irqsave(&desc
->lock
, flags
);
198 if (irq_move_pending(desc
))
199 irq_get_pending(cpumask
, desc
);
201 cpumask_copy(cpumask
, desc
->irq_data
.affinity
);
202 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
204 notify
->notify(notify
, cpumask
);
206 free_cpumask_var(cpumask
);
208 kref_put(¬ify
->kref
, notify
->release
);
212 * irq_set_affinity_notifier - control notification of IRQ affinity changes
213 * @irq: Interrupt for which to enable/disable notification
214 * @notify: Context for notification, or %NULL to disable
215 * notification. Function pointers must be initialised;
216 * the other fields will be initialised by this function.
218 * Must be called in process context. Notification may only be enabled
219 * after the IRQ is allocated and must be disabled before the IRQ is
220 * freed using free_irq().
223 irq_set_affinity_notifier(unsigned int irq
, struct irq_affinity_notify
*notify
)
225 struct irq_desc
*desc
= irq_to_desc(irq
);
226 struct irq_affinity_notify
*old_notify
;
229 /* The release function is promised process context */
235 /* Complete initialisation of *notify */
238 kref_init(¬ify
->kref
);
239 INIT_WORK(¬ify
->work
, irq_affinity_notify
);
242 raw_spin_lock_irqsave(&desc
->lock
, flags
);
243 old_notify
= desc
->affinity_notify
;
244 desc
->affinity_notify
= notify
;
245 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
248 kref_put(&old_notify
->kref
, old_notify
->release
);
252 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier
);
254 #ifndef CONFIG_AUTO_IRQ_AFFINITY
256 * Generic version of the affinity autoselector.
259 setup_affinity(unsigned int irq
, struct irq_desc
*desc
, struct cpumask
*mask
)
261 struct irq_chip
*chip
= irq_desc_get_chip(desc
);
262 struct cpumask
*set
= irq_default_affinity
;
265 /* Excludes PER_CPU and NO_BALANCE interrupts */
266 if (!irq_can_set_affinity(irq
))
270 * Preserve an userspace affinity setup, but make sure that
271 * one of the targets is online.
273 if (irqd_has_set(&desc
->irq_data
, IRQD_AFFINITY_SET
)) {
274 if (cpumask_intersects(desc
->irq_data
.affinity
,
276 set
= desc
->irq_data
.affinity
;
278 irq_compat_clr_affinity(desc
);
279 irqd_clear(&desc
->irq_data
, IRQD_AFFINITY_SET
);
283 cpumask_and(mask
, cpu_online_mask
, set
);
284 ret
= chip
->irq_set_affinity(&desc
->irq_data
, mask
, false);
286 case IRQ_SET_MASK_OK
:
287 cpumask_copy(desc
->irq_data
.affinity
, mask
);
288 case IRQ_SET_MASK_OK_NOCOPY
:
289 irq_set_thread_affinity(desc
);
295 setup_affinity(unsigned int irq
, struct irq_desc
*d
, struct cpumask
*mask
)
297 return irq_select_affinity(irq
);
302 * Called when affinity is set via /proc/irq
304 int irq_select_affinity_usr(unsigned int irq
, struct cpumask
*mask
)
306 struct irq_desc
*desc
= irq_to_desc(irq
);
310 raw_spin_lock_irqsave(&desc
->lock
, flags
);
311 ret
= setup_affinity(irq
, desc
, mask
);
312 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
318 setup_affinity(unsigned int irq
, struct irq_desc
*desc
, struct cpumask
*mask
)
324 void __disable_irq(struct irq_desc
*desc
, unsigned int irq
, bool suspend
)
327 if (!desc
->action
|| (desc
->action
->flags
& IRQF_NO_SUSPEND
))
329 desc
->istate
|= IRQS_SUSPENDED
;
336 static int __disable_irq_nosync(unsigned int irq
)
339 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
);
343 __disable_irq(desc
, irq
, false);
344 irq_put_desc_busunlock(desc
, flags
);
349 * disable_irq_nosync - disable an irq without waiting
350 * @irq: Interrupt to disable
352 * Disable the selected interrupt line. Disables and Enables are
354 * Unlike disable_irq(), this function does not ensure existing
355 * instances of the IRQ handler have completed before returning.
357 * This function may be called from IRQ context.
359 void disable_irq_nosync(unsigned int irq
)
361 __disable_irq_nosync(irq
);
363 EXPORT_SYMBOL(disable_irq_nosync
);
366 * disable_irq - disable an irq and wait for completion
367 * @irq: Interrupt to disable
369 * Disable the selected interrupt line. Enables and Disables are
371 * This function waits for any pending IRQ handlers for this interrupt
372 * to complete before returning. If you use this function while
373 * holding a resource the IRQ handler may need you will deadlock.
375 * This function may be called - with care - from IRQ context.
377 void disable_irq(unsigned int irq
)
379 if (!__disable_irq_nosync(irq
))
380 synchronize_irq(irq
);
382 EXPORT_SYMBOL(disable_irq
);
384 void __enable_irq(struct irq_desc
*desc
, unsigned int irq
, bool resume
)
387 if (!(desc
->istate
& IRQS_SUSPENDED
)) {
390 if (!(desc
->action
->flags
& IRQF_FORCE_RESUME
))
392 /* Pretend that it got disabled ! */
395 desc
->istate
&= ~IRQS_SUSPENDED
;
398 switch (desc
->depth
) {
401 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n", irq
);
404 if (desc
->istate
& IRQS_SUSPENDED
)
406 /* Prevent probing on this irq: */
407 irq_settings_set_noprobe(desc
);
409 check_irq_resend(desc
, irq
);
418 * enable_irq - enable handling of an irq
419 * @irq: Interrupt to enable
421 * Undoes the effect of one call to disable_irq(). If this
422 * matches the last disable, processing of interrupts on this
423 * IRQ line is re-enabled.
425 * This function may be called from IRQ context only when
426 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
428 void enable_irq(unsigned int irq
)
431 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
);
435 if (WARN(!desc
->irq_data
.chip
,
436 KERN_ERR
"enable_irq before setup/request_irq: irq %u\n", irq
))
439 __enable_irq(desc
, irq
, false);
441 irq_put_desc_busunlock(desc
, flags
);
443 EXPORT_SYMBOL(enable_irq
);
445 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
447 struct irq_desc
*desc
= irq_to_desc(irq
);
450 if (desc
->irq_data
.chip
->irq_set_wake
)
451 ret
= desc
->irq_data
.chip
->irq_set_wake(&desc
->irq_data
, on
);
457 * irq_set_irq_wake - control irq power management wakeup
458 * @irq: interrupt to control
459 * @on: enable/disable power management wakeup
461 * Enable/disable power management wakeup mode, which is
462 * disabled by default. Enables and disables must match,
463 * just as they match for non-wakeup mode support.
465 * Wakeup mode lets this IRQ wake the system from sleep
466 * states like "suspend to RAM".
468 int irq_set_irq_wake(unsigned int irq
, unsigned int on
)
471 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
);
474 /* wakeup-capable irqs can be shared between drivers that
475 * don't need to have the same sleep mode behaviors.
478 if (desc
->wake_depth
++ == 0) {
479 ret
= set_irq_wake_real(irq
, on
);
481 desc
->wake_depth
= 0;
483 irqd_set(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
486 if (desc
->wake_depth
== 0) {
487 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
488 } else if (--desc
->wake_depth
== 0) {
489 ret
= set_irq_wake_real(irq
, on
);
491 desc
->wake_depth
= 1;
493 irqd_clear(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
496 irq_put_desc_busunlock(desc
, flags
);
499 EXPORT_SYMBOL(irq_set_irq_wake
);
502 * Internal function that tells the architecture code whether a
503 * particular irq has been exclusively allocated or is available
506 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
509 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
);
515 if (irq_settings_can_request(desc
)) {
517 if (irqflags
& desc
->action
->flags
& IRQF_SHARED
)
520 irq_put_desc_unlock(desc
, flags
);
524 int __irq_set_trigger(struct irq_desc
*desc
, unsigned int irq
,
527 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 flags
&= IRQ_TYPE_SENSE_MASK
;
542 if (chip
->flags
& IRQCHIP_SET_TYPE_MASKED
) {
543 if (!(desc
->istate
& IRQS_MASKED
))
545 if (!(desc
->istate
& IRQS_DISABLED
))
549 /* caller masked out all except trigger mode flags */
550 ret
= chip
->irq_set_type(&desc
->irq_data
, flags
);
553 case IRQ_SET_MASK_OK
:
554 irqd_clear(&desc
->irq_data
, IRQD_TRIGGER_MASK
);
555 irqd_set(&desc
->irq_data
, flags
);
557 case IRQ_SET_MASK_OK_NOCOPY
:
558 flags
= irqd_get_trigger_type(&desc
->irq_data
);
559 irq_settings_set_trigger_mask(desc
, flags
);
560 irqd_clear(&desc
->irq_data
, IRQD_LEVEL
);
561 irq_settings_clr_level(desc
);
562 if (flags
& IRQ_TYPE_LEVEL_MASK
) {
563 irq_settings_set_level(desc
);
564 irqd_set(&desc
->irq_data
, IRQD_LEVEL
);
567 if (chip
!= desc
->irq_data
.chip
)
568 irq_chip_set_defaults(desc
->irq_data
.chip
);
572 pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
573 flags
, irq
, chip
->irq_set_type
);
581 * Default primary interrupt handler for threaded interrupts. Is
582 * assigned as primary handler when request_threaded_irq is called
583 * with handler == NULL. Useful for oneshot interrupts.
585 static irqreturn_t
irq_default_primary_handler(int irq
, void *dev_id
)
587 return IRQ_WAKE_THREAD
;
591 * Primary handler for nested threaded interrupts. Should never be
594 static irqreturn_t
irq_nested_primary_handler(int irq
, void *dev_id
)
596 WARN(1, "Primary handler called for nested irq %d\n", irq
);
600 static int irq_wait_for_interrupt(struct irqaction
*action
)
602 while (!kthread_should_stop()) {
603 set_current_state(TASK_INTERRUPTIBLE
);
605 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
606 &action
->thread_flags
)) {
607 __set_current_state(TASK_RUNNING
);
616 * Oneshot interrupts keep the irq line masked until the threaded
617 * handler finished. unmask if the interrupt has not been disabled and
620 static void irq_finalize_oneshot(struct irq_desc
*desc
,
621 struct irqaction
*action
, bool force
)
623 if (!(desc
->istate
& IRQS_ONESHOT
))
627 raw_spin_lock_irq(&desc
->lock
);
630 * Implausible though it may be we need to protect us against
631 * the following scenario:
633 * The thread is faster done than the hard interrupt handler
634 * on the other CPU. If we unmask the irq line then the
635 * interrupt can come in again and masks the line, leaves due
636 * to IRQS_INPROGRESS and the irq line is masked forever.
638 * This also serializes the state of shared oneshot handlers
639 * versus "desc->threads_onehsot |= action->thread_mask;" in
640 * irq_wake_thread(). See the comment there which explains the
643 if (unlikely(desc
->istate
& IRQS_INPROGRESS
)) {
644 raw_spin_unlock_irq(&desc
->lock
);
645 chip_bus_sync_unlock(desc
);
651 * Now check again, whether the thread should run. Otherwise
652 * we would clear the threads_oneshot bit of this thread which
655 if (!force
&& test_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
658 desc
->threads_oneshot
&= ~action
->thread_mask
;
660 if (!desc
->threads_oneshot
&& !(desc
->istate
& IRQS_DISABLED
) &&
661 (desc
->istate
& IRQS_MASKED
)) {
662 irq_compat_clr_masked(desc
);
663 desc
->istate
&= ~IRQS_MASKED
;
664 desc
->irq_data
.chip
->irq_unmask(&desc
->irq_data
);
667 raw_spin_unlock_irq(&desc
->lock
);
668 chip_bus_sync_unlock(desc
);
673 * Check whether we need to chasnge the affinity of the interrupt thread.
676 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
)
680 if (!test_and_clear_bit(IRQTF_AFFINITY
, &action
->thread_flags
))
684 * In case we are out of memory we set IRQTF_AFFINITY again and
685 * try again next time
687 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
688 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
692 raw_spin_lock_irq(&desc
->lock
);
693 cpumask_copy(mask
, desc
->irq_data
.affinity
);
694 raw_spin_unlock_irq(&desc
->lock
);
696 set_cpus_allowed_ptr(current
, mask
);
697 free_cpumask_var(mask
);
701 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
) { }
705 * Interrupt handler thread
707 static int irq_thread(void *data
)
709 static const struct sched_param param
= {
710 .sched_priority
= MAX_USER_RT_PRIO
/2,
712 struct irqaction
*action
= data
;
713 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
716 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
717 current
->irqaction
= action
;
719 while (!irq_wait_for_interrupt(action
)) {
721 irq_thread_check_affinity(desc
, action
);
723 atomic_inc(&desc
->threads_active
);
725 raw_spin_lock_irq(&desc
->lock
);
726 if (unlikely(desc
->istate
& IRQS_DISABLED
)) {
728 * CHECKME: We might need a dedicated
729 * IRQ_THREAD_PENDING flag here, which
730 * retriggers the thread in check_irq_resend()
731 * but AFAICT IRQS_PENDING should be fine as it
732 * retriggers the interrupt itself --- tglx
734 irq_compat_set_pending(desc
);
735 desc
->istate
|= IRQS_PENDING
;
736 raw_spin_unlock_irq(&desc
->lock
);
738 raw_spin_unlock_irq(&desc
->lock
);
740 action
->thread_fn(action
->irq
, action
->dev_id
);
742 irq_finalize_oneshot(desc
, action
, false);
745 wake
= atomic_dec_and_test(&desc
->threads_active
);
747 if (wake
&& waitqueue_active(&desc
->wait_for_threads
))
748 wake_up(&desc
->wait_for_threads
);
751 /* Prevent a stale desc->threads_oneshot */
752 irq_finalize_oneshot(desc
, action
, true);
755 * Clear irqaction. Otherwise exit_irq_thread() would make
756 * fuzz about an active irq thread going into nirvana.
758 current
->irqaction
= NULL
;
763 * Called from do_exit()
765 void exit_irq_thread(void)
767 struct task_struct
*tsk
= current
;
768 struct irq_desc
*desc
;
774 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
775 tsk
->comm
? tsk
->comm
: "", tsk
->pid
, tsk
->irqaction
->irq
);
777 desc
= irq_to_desc(tsk
->irqaction
->irq
);
780 * Prevent a stale desc->threads_oneshot. Must be called
781 * before setting the IRQTF_DIED flag.
783 irq_finalize_oneshot(desc
, tsk
->irqaction
, true);
786 * Set the THREAD DIED flag to prevent further wakeups of the
787 * soon to be gone threaded handler.
789 set_bit(IRQTF_DIED
, &tsk
->irqaction
->flags
);
793 * Internal function to register an irqaction - typically used to
794 * allocate special interrupts that are part of the architecture.
797 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
799 struct irqaction
*old
, **old_ptr
;
800 const char *old_name
= NULL
;
801 unsigned long flags
, thread_mask
= 0;
802 int ret
, nested
, shared
= 0;
808 if (desc
->irq_data
.chip
== &no_irq_chip
)
811 * Some drivers like serial.c use request_irq() heavily,
812 * so we have to be careful not to interfere with a
815 if (new->flags
& IRQF_SAMPLE_RANDOM
) {
817 * This function might sleep, we want to call it first,
818 * outside of the atomic block.
819 * Yes, this might clear the entropy pool if the wrong
820 * driver is attempted to be loaded, without actually
821 * installing a new handler, but is this really a problem,
822 * only the sysadmin is able to do this.
824 rand_initialize_irq(irq
);
827 /* Oneshot interrupts are not allowed with shared */
828 if ((new->flags
& IRQF_ONESHOT
) && (new->flags
& IRQF_SHARED
))
832 * Check whether the interrupt nests into another interrupt
835 nested
= irq_settings_is_nested_thread(desc
);
840 * Replace the primary handler which was provided from
841 * the driver for non nested interrupt handling by the
842 * dummy function which warns when called.
844 new->handler
= irq_nested_primary_handler
;
848 * Create a handler thread when a thread function is supplied
849 * and the interrupt does not nest into another interrupt
852 if (new->thread_fn
&& !nested
) {
853 struct task_struct
*t
;
855 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
860 * We keep the reference to the task struct even if
861 * the thread dies to avoid that the interrupt code
862 * references an already freed task_struct.
868 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
874 * The following block of code has to be executed atomically
876 raw_spin_lock_irqsave(&desc
->lock
, flags
);
877 old_ptr
= &desc
->action
;
881 * Can't share interrupts unless both agree to and are
882 * the same type (level, edge, polarity). So both flag
883 * fields must have IRQF_SHARED set and the bits which
884 * set the trigger type must match.
886 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
887 ((old
->flags
^ new->flags
) & IRQF_TRIGGER_MASK
)) {
888 old_name
= old
->name
;
892 /* All handlers must agree on per-cpuness */
893 if ((old
->flags
& IRQF_PERCPU
) !=
894 (new->flags
& IRQF_PERCPU
))
897 /* add new interrupt at end of irq queue */
899 thread_mask
|= old
->thread_mask
;
900 old_ptr
= &old
->next
;
907 * Setup the thread mask for this irqaction. Unlikely to have
908 * 32 resp 64 irqs sharing one line, but who knows.
910 if (new->flags
& IRQF_ONESHOT
&& thread_mask
== ~0UL) {
914 new->thread_mask
= 1 << ffz(thread_mask
);
917 irq_chip_set_defaults(desc
->irq_data
.chip
);
919 init_waitqueue_head(&desc
->wait_for_threads
);
921 /* Setup the type (level, edge polarity) if configured: */
922 if (new->flags
& IRQF_TRIGGER_MASK
) {
923 ret
= __irq_set_trigger(desc
, irq
,
924 new->flags
& IRQF_TRIGGER_MASK
);
930 desc
->istate
&= ~(IRQS_AUTODETECT
| IRQS_SPURIOUS_DISABLED
| \
931 IRQS_INPROGRESS
| IRQS_ONESHOT
| \
934 if (new->flags
& IRQF_PERCPU
) {
935 irqd_set(&desc
->irq_data
, IRQD_PER_CPU
);
936 irq_settings_set_per_cpu(desc
);
939 if (new->flags
& IRQF_ONESHOT
)
940 desc
->istate
|= IRQS_ONESHOT
;
942 if (irq_settings_can_autoenable(desc
))
945 /* Undo nested disables: */
948 /* Exclude IRQ from balancing if requested */
949 if (new->flags
& IRQF_NOBALANCING
) {
950 irq_settings_set_no_balancing(desc
);
951 irqd_set(&desc
->irq_data
, IRQD_NO_BALANCING
);
954 /* Set default affinity mask once everything is setup */
955 setup_affinity(irq
, desc
, mask
);
957 } else if (new->flags
& IRQF_TRIGGER_MASK
) {
958 unsigned int nmsk
= new->flags
& IRQF_TRIGGER_MASK
;
959 unsigned int omsk
= irq_settings_get_trigger_mask(desc
);
962 /* hope the handler works with current trigger mode */
963 pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
970 /* Reset broken irq detection when installing new handler */
972 desc
->irqs_unhandled
= 0;
975 * Check whether we disabled the irq via the spurious handler
976 * before. Reenable it and give it another chance.
978 if (shared
&& (desc
->istate
& IRQS_SPURIOUS_DISABLED
)) {
979 desc
->istate
&= ~IRQS_SPURIOUS_DISABLED
;
980 __enable_irq(desc
, irq
, false);
983 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
986 * Strictly no need to wake it up, but hung_task complains
987 * when no hard interrupt wakes the thread up.
990 wake_up_process(new->thread
);
992 register_irq_proc(irq
, desc
);
994 register_handler_proc(irq
, new);
999 #ifdef CONFIG_DEBUG_SHIRQ
1000 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
1001 printk(KERN_ERR
"IRQ handler type mismatch for IRQ %d\n", irq
);
1003 printk(KERN_ERR
"current handler: %s\n", old_name
);
1010 free_cpumask_var(mask
);
1013 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1015 struct task_struct
*t
= new->thread
;
1018 if (likely(!test_bit(IRQTF_DIED
, &new->thread_flags
)))
1026 * setup_irq - setup an interrupt
1027 * @irq: Interrupt line to setup
1028 * @act: irqaction for the interrupt
1030 * Used to statically setup interrupts in the early boot process.
1032 int setup_irq(unsigned int irq
, struct irqaction
*act
)
1035 struct irq_desc
*desc
= irq_to_desc(irq
);
1037 chip_bus_lock(desc
);
1038 retval
= __setup_irq(irq
, desc
, act
);
1039 chip_bus_sync_unlock(desc
);
1043 EXPORT_SYMBOL_GPL(setup_irq
);
1046 * Internal function to unregister an irqaction - used to free
1047 * regular and special interrupts that are part of the architecture.
1049 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
1051 struct irq_desc
*desc
= irq_to_desc(irq
);
1052 struct irqaction
*action
, **action_ptr
;
1053 unsigned long flags
;
1055 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1060 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1063 * There can be multiple actions per IRQ descriptor, find the right
1064 * one based on the dev_id:
1066 action_ptr
= &desc
->action
;
1068 action
= *action_ptr
;
1071 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1072 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1077 if (action
->dev_id
== dev_id
)
1079 action_ptr
= &action
->next
;
1082 /* Found it - now remove it from the list of entries: */
1083 *action_ptr
= action
->next
;
1085 /* Currently used only by UML, might disappear one day: */
1086 #ifdef CONFIG_IRQ_RELEASE_METHOD
1087 if (desc
->irq_data
.chip
->release
)
1088 desc
->irq_data
.chip
->release(irq
, dev_id
);
1091 /* If this was the last handler, shut down the IRQ line: */
1096 /* make sure affinity_hint is cleaned up */
1097 if (WARN_ON_ONCE(desc
->affinity_hint
))
1098 desc
->affinity_hint
= NULL
;
1101 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1103 unregister_handler_proc(irq
, action
);
1105 /* Make sure it's not being used on another CPU: */
1106 synchronize_irq(irq
);
1108 #ifdef CONFIG_DEBUG_SHIRQ
1110 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1111 * event to happen even now it's being freed, so let's make sure that
1112 * is so by doing an extra call to the handler ....
1114 * ( We do this after actually deregistering it, to make sure that a
1115 * 'real' IRQ doesn't run in * parallel with our fake. )
1117 if (action
->flags
& IRQF_SHARED
) {
1118 local_irq_save(flags
);
1119 action
->handler(irq
, dev_id
);
1120 local_irq_restore(flags
);
1124 if (action
->thread
) {
1125 if (!test_bit(IRQTF_DIED
, &action
->thread_flags
))
1126 kthread_stop(action
->thread
);
1127 put_task_struct(action
->thread
);
1134 * remove_irq - free an interrupt
1135 * @irq: Interrupt line to free
1136 * @act: irqaction for the interrupt
1138 * Used to remove interrupts statically setup by the early boot process.
1140 void remove_irq(unsigned int irq
, struct irqaction
*act
)
1142 __free_irq(irq
, act
->dev_id
);
1144 EXPORT_SYMBOL_GPL(remove_irq
);
1147 * free_irq - free an interrupt allocated with request_irq
1148 * @irq: Interrupt line to free
1149 * @dev_id: Device identity to free
1151 * Remove an interrupt handler. The handler is removed and if the
1152 * interrupt line is no longer in use by any driver it is disabled.
1153 * On a shared IRQ the caller must ensure the interrupt is disabled
1154 * on the card it drives before calling this function. The function
1155 * does not return until any executing interrupts for this IRQ
1158 * This function must not be called from interrupt context.
1160 void free_irq(unsigned int irq
, void *dev_id
)
1162 struct irq_desc
*desc
= irq_to_desc(irq
);
1168 if (WARN_ON(desc
->affinity_notify
))
1169 desc
->affinity_notify
= NULL
;
1172 chip_bus_lock(desc
);
1173 kfree(__free_irq(irq
, dev_id
));
1174 chip_bus_sync_unlock(desc
);
1176 EXPORT_SYMBOL(free_irq
);
1179 * request_threaded_irq - allocate an interrupt line
1180 * @irq: Interrupt line to allocate
1181 * @handler: Function to be called when the IRQ occurs.
1182 * Primary handler for threaded interrupts
1183 * If NULL and thread_fn != NULL the default
1184 * primary handler is installed
1185 * @thread_fn: Function called from the irq handler thread
1186 * If NULL, no irq thread is created
1187 * @irqflags: Interrupt type flags
1188 * @devname: An ascii name for the claiming device
1189 * @dev_id: A cookie passed back to the handler function
1191 * This call allocates interrupt resources and enables the
1192 * interrupt line and IRQ handling. From the point this
1193 * call is made your handler function may be invoked. Since
1194 * your handler function must clear any interrupt the board
1195 * raises, you must take care both to initialise your hardware
1196 * and to set up the interrupt handler in the right order.
1198 * If you want to set up a threaded irq handler for your device
1199 * then you need to supply @handler and @thread_fn. @handler ist
1200 * still called in hard interrupt context and has to check
1201 * whether the interrupt originates from the device. If yes it
1202 * needs to disable the interrupt on the device and return
1203 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1204 * @thread_fn. This split handler design is necessary to support
1205 * shared interrupts.
1207 * Dev_id must be globally unique. Normally the address of the
1208 * device data structure is used as the cookie. Since the handler
1209 * receives this value it makes sense to use it.
1211 * If your interrupt is shared you must pass a non NULL dev_id
1212 * as this is required when freeing the interrupt.
1216 * IRQF_SHARED Interrupt is shared
1217 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
1218 * IRQF_TRIGGER_* Specify active edge(s) or level
1221 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
1222 irq_handler_t thread_fn
, unsigned long irqflags
,
1223 const char *devname
, void *dev_id
)
1225 struct irqaction
*action
;
1226 struct irq_desc
*desc
;
1230 * Sanity-check: shared interrupts must pass in a real dev-ID,
1231 * otherwise we'll have trouble later trying to figure out
1232 * which interrupt is which (messes up the interrupt freeing
1235 if ((irqflags
& IRQF_SHARED
) && !dev_id
)
1238 desc
= irq_to_desc(irq
);
1242 if (!irq_settings_can_request(desc
))
1248 handler
= irq_default_primary_handler
;
1251 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1255 action
->handler
= handler
;
1256 action
->thread_fn
= thread_fn
;
1257 action
->flags
= irqflags
;
1258 action
->name
= devname
;
1259 action
->dev_id
= dev_id
;
1261 chip_bus_lock(desc
);
1262 retval
= __setup_irq(irq
, desc
, action
);
1263 chip_bus_sync_unlock(desc
);
1268 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1269 if (!retval
&& (irqflags
& IRQF_SHARED
)) {
1271 * It's a shared IRQ -- the driver ought to be prepared for it
1272 * to happen immediately, so let's make sure....
1273 * We disable the irq to make sure that a 'real' IRQ doesn't
1274 * run in parallel with our fake.
1276 unsigned long flags
;
1279 local_irq_save(flags
);
1281 handler(irq
, dev_id
);
1283 local_irq_restore(flags
);
1289 EXPORT_SYMBOL(request_threaded_irq
);
1292 * request_any_context_irq - allocate an interrupt line
1293 * @irq: Interrupt line to allocate
1294 * @handler: Function to be called when the IRQ occurs.
1295 * Threaded handler for threaded interrupts.
1296 * @flags: Interrupt type flags
1297 * @name: An ascii name for the claiming device
1298 * @dev_id: A cookie passed back to the handler function
1300 * This call allocates interrupt resources and enables the
1301 * interrupt line and IRQ handling. It selects either a
1302 * hardirq or threaded handling method depending on the
1305 * On failure, it returns a negative value. On success,
1306 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1308 int request_any_context_irq(unsigned int irq
, irq_handler_t handler
,
1309 unsigned long flags
, const char *name
, void *dev_id
)
1311 struct irq_desc
*desc
= irq_to_desc(irq
);
1317 if (irq_settings_is_nested_thread(desc
)) {
1318 ret
= request_threaded_irq(irq
, NULL
, handler
,
1319 flags
, name
, dev_id
);
1320 return !ret
? IRQC_IS_NESTED
: ret
;
1323 ret
= request_irq(irq
, handler
, flags
, name
, dev_id
);
1324 return !ret
? IRQC_IS_HARDIRQ
: ret
;
1326 EXPORT_SYMBOL_GPL(request_any_context_irq
);