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"
20 #ifdef CONFIG_IRQ_FORCED_THREADING
21 __read_mostly bool force_irqthreads;
23 static int __init setup_forced_irqthreads(char *arg)
25 force_irqthreads = true;
28 early_param("threadirqs", setup_forced_irqthreads);
32 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
33 * @irq: interrupt number to wait for
35 * This function waits for any pending IRQ handlers for this interrupt
36 * to complete before returning. If you use this function while
37 * holding a resource the IRQ handler may need you will deadlock.
39 * This function may be called - with care - from IRQ context.
41 void synchronize_irq(unsigned int irq)
43 struct irq_desc *desc = irq_to_desc(irq);
53 * Wait until we're out of the critical section. This might
54 * give the wrong answer due to the lack of memory barriers.
56 while (irqd_irq_inprogress(&desc->irq_data))
59 /* Ok, that indicated we're done: double-check carefully. */
60 raw_spin_lock_irqsave(&desc->lock, flags);
61 inprogress = irqd_irq_inprogress(&desc->irq_data);
62 raw_spin_unlock_irqrestore(&desc->lock, flags);
64 /* Oops, that failed? */
68 * We made sure that no hardirq handler is running. Now verify
69 * that no threaded handlers are active.
71 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
73 EXPORT_SYMBOL(synchronize_irq);
76 cpumask_var_t irq_default_affinity;
79 * irq_can_set_affinity - Check if the affinity of a given irq can be set
80 * @irq: Interrupt to check
83 int irq_can_set_affinity(unsigned int irq)
85 struct irq_desc *desc = irq_to_desc(irq);
87 if (!desc || !irqd_can_balance(&desc->irq_data) ||
88 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
95 * irq_set_thread_affinity - Notify irq threads to adjust affinity
96 * @desc: irq descriptor which has affitnity changed
98 * We just set IRQTF_AFFINITY and delegate the affinity setting
99 * to the interrupt thread itself. We can not call
100 * set_cpus_allowed_ptr() here as we hold desc->lock and this
101 * code can be called from hard interrupt context.
103 void irq_set_thread_affinity(struct irq_desc *desc)
105 struct irqaction *action = desc->action;
109 set_bit(IRQTF_AFFINITY, &action->thread_flags);
110 action = action->next;
114 #ifdef CONFIG_GENERIC_PENDING_IRQ
115 static inline bool irq_can_move_pcntxt(struct irq_data *data)
117 return irqd_can_move_in_process_context(data);
119 static inline bool irq_move_pending(struct irq_data *data)
121 return irqd_is_setaffinity_pending(data);
124 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
126 cpumask_copy(desc->pending_mask, mask);
129 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
131 cpumask_copy(mask, desc->pending_mask);
134 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
135 static inline bool irq_move_pending(struct irq_desc *data) { return false; }
137 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
139 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
142 int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
144 struct irq_chip *chip = irq_data_get_irq_chip(data);
145 struct irq_desc *desc = irq_data_to_desc(data);
148 if (!chip || !chip->irq_set_affinity)
151 if (irq_can_move_pcntxt(data)) {
152 ret = chip->irq_set_affinity(data, mask, false);
154 case IRQ_SET_MASK_OK:
155 cpumask_copy(data->affinity, mask);
156 case IRQ_SET_MASK_OK_NOCOPY:
157 irq_set_thread_affinity(desc);
161 irqd_set_move_pending(data);
162 irq_copy_pending(desc, mask);
165 if (desc->affinity_notify) {
166 kref_get(&desc->affinity_notify->kref);
167 schedule_work(&desc->affinity_notify->work);
169 irq_compat_set_affinity(desc);
170 irqd_set(data, IRQD_AFFINITY_SET);
176 * irq_set_affinity - Set the irq affinity of a given irq
177 * @irq: Interrupt to set affinity
181 int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
183 struct irq_desc *desc = irq_to_desc(irq);
190 raw_spin_lock_irqsave(&desc->lock, flags);
191 ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
192 raw_spin_unlock_irqrestore(&desc->lock, flags);
196 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
199 struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
203 desc->affinity_hint = m;
204 irq_put_desc_unlock(desc, flags);
207 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
209 static void irq_affinity_notify(struct work_struct *work)
211 struct irq_affinity_notify *notify =
212 container_of(work, struct irq_affinity_notify, work);
213 struct irq_desc *desc = irq_to_desc(notify->irq);
214 cpumask_var_t cpumask;
217 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
220 raw_spin_lock_irqsave(&desc->lock, flags);
221 if (irq_move_pending(&desc->irq_data))
222 irq_get_pending(cpumask, desc);
224 cpumask_copy(cpumask, desc->irq_data.affinity);
225 raw_spin_unlock_irqrestore(&desc->lock, flags);
227 notify->notify(notify, cpumask);
229 free_cpumask_var(cpumask);
231 kref_put(¬ify->kref, notify->release);
235 * irq_set_affinity_notifier - control notification of IRQ affinity changes
236 * @irq: Interrupt for which to enable/disable notification
237 * @notify: Context for notification, or %NULL to disable
238 * notification. Function pointers must be initialised;
239 * the other fields will be initialised by this function.
241 * Must be called in process context. Notification may only be enabled
242 * after the IRQ is allocated and must be disabled before the IRQ is
243 * freed using free_irq().
246 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
248 struct irq_desc *desc = irq_to_desc(irq);
249 struct irq_affinity_notify *old_notify;
252 /* The release function is promised process context */
258 /* Complete initialisation of *notify */
261 kref_init(¬ify->kref);
262 INIT_WORK(¬ify->work, irq_affinity_notify);
265 raw_spin_lock_irqsave(&desc->lock, flags);
266 old_notify = desc->affinity_notify;
267 desc->affinity_notify = notify;
268 raw_spin_unlock_irqrestore(&desc->lock, flags);
271 kref_put(&old_notify->kref, old_notify->release);
275 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
277 #ifndef CONFIG_AUTO_IRQ_AFFINITY
279 * Generic version of the affinity autoselector.
282 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
284 struct irq_chip *chip = irq_desc_get_chip(desc);
285 struct cpumask *set = irq_default_affinity;
288 /* Excludes PER_CPU and NO_BALANCE interrupts */
289 if (!irq_can_set_affinity(irq))
293 * Preserve an userspace affinity setup, but make sure that
294 * one of the targets is online.
296 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
297 if (cpumask_intersects(desc->irq_data.affinity,
299 set = desc->irq_data.affinity;
301 irq_compat_clr_affinity(desc);
302 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
306 cpumask_and(mask, cpu_online_mask, set);
307 ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
309 case IRQ_SET_MASK_OK:
310 cpumask_copy(desc->irq_data.affinity, mask);
311 case IRQ_SET_MASK_OK_NOCOPY:
312 irq_set_thread_affinity(desc);
318 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
320 return irq_select_affinity(irq);
325 * Called when affinity is set via /proc/irq
327 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
329 struct irq_desc *desc = irq_to_desc(irq);
333 raw_spin_lock_irqsave(&desc->lock, flags);
334 ret = setup_affinity(irq, desc, mask);
335 raw_spin_unlock_irqrestore(&desc->lock, flags);
341 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
347 void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
350 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
352 desc->istate |= IRQS_SUSPENDED;
359 static int __disable_irq_nosync(unsigned int irq)
362 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
366 __disable_irq(desc, irq, false);
367 irq_put_desc_busunlock(desc, flags);
372 * disable_irq_nosync - disable an irq without waiting
373 * @irq: Interrupt to disable
375 * Disable the selected interrupt line. Disables and Enables are
377 * Unlike disable_irq(), this function does not ensure existing
378 * instances of the IRQ handler have completed before returning.
380 * This function may be called from IRQ context.
382 void disable_irq_nosync(unsigned int irq)
384 __disable_irq_nosync(irq);
386 EXPORT_SYMBOL(disable_irq_nosync);
389 * disable_irq - disable an irq and wait for completion
390 * @irq: Interrupt to disable
392 * Disable the selected interrupt line. Enables and Disables are
394 * This function waits for any pending IRQ handlers for this interrupt
395 * to complete before returning. If you use this function while
396 * holding a resource the IRQ handler may need you will deadlock.
398 * This function may be called - with care - from IRQ context.
400 void disable_irq(unsigned int irq)
402 if (!__disable_irq_nosync(irq))
403 synchronize_irq(irq);
405 EXPORT_SYMBOL(disable_irq);
407 void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
410 if (!(desc->istate & IRQS_SUSPENDED)) {
413 if (!(desc->action->flags & IRQF_FORCE_RESUME))
415 /* Pretend that it got disabled ! */
418 desc->istate &= ~IRQS_SUSPENDED;
421 switch (desc->depth) {
424 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
427 if (desc->istate & IRQS_SUSPENDED)
429 /* Prevent probing on this irq: */
430 irq_settings_set_noprobe(desc);
432 check_irq_resend(desc, irq);
441 * enable_irq - enable handling of an irq
442 * @irq: Interrupt to enable
444 * Undoes the effect of one call to disable_irq(). If this
445 * matches the last disable, processing of interrupts on this
446 * IRQ line is re-enabled.
448 * This function may be called from IRQ context only when
449 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
451 void enable_irq(unsigned int irq)
454 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
458 if (WARN(!desc->irq_data.chip,
459 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
462 __enable_irq(desc, irq, false);
464 irq_put_desc_busunlock(desc, flags);
466 EXPORT_SYMBOL(enable_irq);
468 static int set_irq_wake_real(unsigned int irq, unsigned int on)
470 struct irq_desc *desc = irq_to_desc(irq);
473 if (desc->irq_data.chip->irq_set_wake)
474 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
480 * irq_set_irq_wake - control irq power management wakeup
481 * @irq: interrupt to control
482 * @on: enable/disable power management wakeup
484 * Enable/disable power management wakeup mode, which is
485 * disabled by default. Enables and disables must match,
486 * just as they match for non-wakeup mode support.
488 * Wakeup mode lets this IRQ wake the system from sleep
489 * states like "suspend to RAM".
491 int irq_set_irq_wake(unsigned int irq, unsigned int on)
494 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
497 /* wakeup-capable irqs can be shared between drivers that
498 * don't need to have the same sleep mode behaviors.
501 if (desc->wake_depth++ == 0) {
502 ret = set_irq_wake_real(irq, on);
504 desc->wake_depth = 0;
506 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
509 if (desc->wake_depth == 0) {
510 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
511 } else if (--desc->wake_depth == 0) {
512 ret = set_irq_wake_real(irq, on);
514 desc->wake_depth = 1;
516 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
519 irq_put_desc_busunlock(desc, flags);
522 EXPORT_SYMBOL(irq_set_irq_wake);
525 * Internal function that tells the architecture code whether a
526 * particular irq has been exclusively allocated or is available
529 int can_request_irq(unsigned int irq, unsigned long irqflags)
532 struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
538 if (irq_settings_can_request(desc)) {
540 if (irqflags & desc->action->flags & IRQF_SHARED)
543 irq_put_desc_unlock(desc, flags);
547 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
550 struct irq_chip *chip = desc->irq_data.chip;
553 if (!chip || !chip->irq_set_type) {
555 * IRQF_TRIGGER_* but the PIC does not support multiple
558 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
559 chip ? (chip->name ? : "unknown") : "unknown");
563 flags &= IRQ_TYPE_SENSE_MASK;
565 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
566 if (!irqd_irq_masked(&desc->irq_data))
568 if (!irqd_irq_disabled(&desc->irq_data))
572 /* caller masked out all except trigger mode flags */
573 ret = chip->irq_set_type(&desc->irq_data, flags);
576 case IRQ_SET_MASK_OK:
577 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
578 irqd_set(&desc->irq_data, flags);
580 case IRQ_SET_MASK_OK_NOCOPY:
581 flags = irqd_get_trigger_type(&desc->irq_data);
582 irq_settings_set_trigger_mask(desc, flags);
583 irqd_clear(&desc->irq_data, IRQD_LEVEL);
584 irq_settings_clr_level(desc);
585 if (flags & IRQ_TYPE_LEVEL_MASK) {
586 irq_settings_set_level(desc);
587 irqd_set(&desc->irq_data, IRQD_LEVEL);
590 if (chip != desc->irq_data.chip)
591 irq_chip_set_defaults(desc->irq_data.chip);
595 pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
596 flags, irq, chip->irq_set_type);
604 * Default primary interrupt handler for threaded interrupts. Is
605 * assigned as primary handler when request_threaded_irq is called
606 * with handler == NULL. Useful for oneshot interrupts.
608 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
610 return IRQ_WAKE_THREAD;
614 * Primary handler for nested threaded interrupts. Should never be
617 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
619 WARN(1, "Primary handler called for nested irq %d\n", irq);
623 static int irq_wait_for_interrupt(struct irqaction *action)
625 while (!kthread_should_stop()) {
626 set_current_state(TASK_INTERRUPTIBLE);
628 if (test_and_clear_bit(IRQTF_RUNTHREAD,
629 &action->thread_flags)) {
630 __set_current_state(TASK_RUNNING);
639 * Oneshot interrupts keep the irq line masked until the threaded
640 * handler finished. unmask if the interrupt has not been disabled and
643 static void irq_finalize_oneshot(struct irq_desc *desc,
644 struct irqaction *action, bool force)
646 if (!(desc->istate & IRQS_ONESHOT))
650 raw_spin_lock_irq(&desc->lock);
653 * Implausible though it may be we need to protect us against
654 * the following scenario:
656 * The thread is faster done than the hard interrupt handler
657 * on the other CPU. If we unmask the irq line then the
658 * interrupt can come in again and masks the line, leaves due
659 * to IRQS_INPROGRESS and the irq line is masked forever.
661 * This also serializes the state of shared oneshot handlers
662 * versus "desc->threads_onehsot |= action->thread_mask;" in
663 * irq_wake_thread(). See the comment there which explains the
666 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
667 raw_spin_unlock_irq(&desc->lock);
668 chip_bus_sync_unlock(desc);
674 * Now check again, whether the thread should run. Otherwise
675 * we would clear the threads_oneshot bit of this thread which
678 if (!force && test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
681 desc->threads_oneshot &= ~action->thread_mask;
683 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
684 irqd_irq_masked(&desc->irq_data))
688 raw_spin_unlock_irq(&desc->lock);
689 chip_bus_sync_unlock(desc);
694 * Check whether we need to chasnge the affinity of the interrupt thread.
697 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
701 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
705 * In case we are out of memory we set IRQTF_AFFINITY again and
706 * try again next time
708 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
709 set_bit(IRQTF_AFFINITY, &action->thread_flags);
713 raw_spin_lock_irq(&desc->lock);
714 cpumask_copy(mask, desc->irq_data.affinity);
715 raw_spin_unlock_irq(&desc->lock);
717 set_cpus_allowed_ptr(current, mask);
718 free_cpumask_var(mask);
722 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
726 * Interrupts which are not explicitely requested as threaded
727 * interrupts rely on the implicit bh/preempt disable of the hard irq
728 * context. So we need to disable bh here to avoid deadlocks and other
732 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
735 action->thread_fn(action->irq, action->dev_id);
736 irq_finalize_oneshot(desc, action, false);
741 * Interrupts explicitely requested as threaded interupts want to be
742 * preemtible - many of them need to sleep and wait for slow busses to
745 static void irq_thread_fn(struct irq_desc *desc, struct irqaction *action)
747 action->thread_fn(action->irq, action->dev_id);
748 irq_finalize_oneshot(desc, action, false);
752 * Interrupt handler thread
754 static int irq_thread(void *data)
756 static const struct sched_param param = {
757 .sched_priority = MAX_USER_RT_PRIO/2,
759 struct irqaction *action = data;
760 struct irq_desc *desc = irq_to_desc(action->irq);
761 void (*handler_fn)(struct irq_desc *desc, struct irqaction *action);
764 if (force_irqthreads & test_bit(IRQTF_FORCED_THREAD,
765 &action->thread_flags))
766 handler_fn = irq_forced_thread_fn;
768 handler_fn = irq_thread_fn;
770 sched_setscheduler(current, SCHED_FIFO, ¶m);
771 current->irqaction = action;
773 while (!irq_wait_for_interrupt(action)) {
775 irq_thread_check_affinity(desc, action);
777 atomic_inc(&desc->threads_active);
779 raw_spin_lock_irq(&desc->lock);
780 if (unlikely(irqd_irq_disabled(&desc->irq_data))) {
782 * CHECKME: We might need a dedicated
783 * IRQ_THREAD_PENDING flag here, which
784 * retriggers the thread in check_irq_resend()
785 * but AFAICT IRQS_PENDING should be fine as it
786 * retriggers the interrupt itself --- tglx
788 irq_compat_set_pending(desc);
789 desc->istate |= IRQS_PENDING;
790 raw_spin_unlock_irq(&desc->lock);
792 raw_spin_unlock_irq(&desc->lock);
793 handler_fn(desc, action);
796 wake = atomic_dec_and_test(&desc->threads_active);
798 if (wake && waitqueue_active(&desc->wait_for_threads))
799 wake_up(&desc->wait_for_threads);
802 /* Prevent a stale desc->threads_oneshot */
803 irq_finalize_oneshot(desc, action, true);
806 * Clear irqaction. Otherwise exit_irq_thread() would make
807 * fuzz about an active irq thread going into nirvana.
809 current->irqaction = NULL;
814 * Called from do_exit()
816 void exit_irq_thread(void)
818 struct task_struct *tsk = current;
819 struct irq_desc *desc;
825 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
826 tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
828 desc = irq_to_desc(tsk->irqaction->irq);
831 * Prevent a stale desc->threads_oneshot. Must be called
832 * before setting the IRQTF_DIED flag.
834 irq_finalize_oneshot(desc, tsk->irqaction, true);
837 * Set the THREAD DIED flag to prevent further wakeups of the
838 * soon to be gone threaded handler.
840 set_bit(IRQTF_DIED, &tsk->irqaction->flags);
843 static void irq_setup_forced_threading(struct irqaction *new)
845 if (!force_irqthreads)
847 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
850 new->flags |= IRQF_ONESHOT;
852 if (!new->thread_fn) {
853 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
854 new->thread_fn = new->handler;
855 new->handler = irq_default_primary_handler;
860 * Internal function to register an irqaction - typically used to
861 * allocate special interrupts that are part of the architecture.
864 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
866 struct irqaction *old, **old_ptr;
867 const char *old_name = NULL;
868 unsigned long flags, thread_mask = 0;
869 int ret, nested, shared = 0;
875 if (desc->irq_data.chip == &no_irq_chip)
878 * Some drivers like serial.c use request_irq() heavily,
879 * so we have to be careful not to interfere with a
882 if (new->flags & IRQF_SAMPLE_RANDOM) {
884 * This function might sleep, we want to call it first,
885 * outside of the atomic block.
886 * Yes, this might clear the entropy pool if the wrong
887 * driver is attempted to be loaded, without actually
888 * installing a new handler, but is this really a problem,
889 * only the sysadmin is able to do this.
891 rand_initialize_irq(irq);
895 * Check whether the interrupt nests into another interrupt
898 nested = irq_settings_is_nested_thread(desc);
903 * Replace the primary handler which was provided from
904 * the driver for non nested interrupt handling by the
905 * dummy function which warns when called.
907 new->handler = irq_nested_primary_handler;
909 irq_setup_forced_threading(new);
913 * Create a handler thread when a thread function is supplied
914 * and the interrupt does not nest into another interrupt
917 if (new->thread_fn && !nested) {
918 struct task_struct *t;
920 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
925 * We keep the reference to the task struct even if
926 * the thread dies to avoid that the interrupt code
927 * references an already freed task_struct.
933 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
939 * The following block of code has to be executed atomically
941 raw_spin_lock_irqsave(&desc->lock, flags);
942 old_ptr = &desc->action;
946 * Can't share interrupts unless both agree to and are
947 * the same type (level, edge, polarity). So both flag
948 * fields must have IRQF_SHARED set and the bits which
949 * set the trigger type must match. Also all must
952 if (!((old->flags & new->flags) & IRQF_SHARED) ||
953 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
954 ((old->flags ^ new->flags) & IRQF_ONESHOT)) {
955 old_name = old->name;
959 /* All handlers must agree on per-cpuness */
960 if ((old->flags & IRQF_PERCPU) !=
961 (new->flags & IRQF_PERCPU))
964 /* add new interrupt at end of irq queue */
966 thread_mask |= old->thread_mask;
967 old_ptr = &old->next;
974 * Setup the thread mask for this irqaction. Unlikely to have
975 * 32 resp 64 irqs sharing one line, but who knows.
977 if (new->flags & IRQF_ONESHOT && thread_mask == ~0UL) {
981 new->thread_mask = 1 << ffz(thread_mask);
984 irq_chip_set_defaults(desc->irq_data.chip);
986 init_waitqueue_head(&desc->wait_for_threads);
988 /* Setup the type (level, edge polarity) if configured: */
989 if (new->flags & IRQF_TRIGGER_MASK) {
990 ret = __irq_set_trigger(desc, irq,
991 new->flags & IRQF_TRIGGER_MASK);
997 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
998 IRQS_ONESHOT | IRQS_WAITING);
999 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1001 if (new->flags & IRQF_PERCPU) {
1002 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1003 irq_settings_set_per_cpu(desc);
1006 if (new->flags & IRQF_ONESHOT)
1007 desc->istate |= IRQS_ONESHOT;
1009 if (irq_settings_can_autoenable(desc))
1012 /* Undo nested disables: */
1015 /* Exclude IRQ from balancing if requested */
1016 if (new->flags & IRQF_NOBALANCING) {
1017 irq_settings_set_no_balancing(desc);
1018 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1021 /* Set default affinity mask once everything is setup */
1022 setup_affinity(irq, desc, mask);
1024 } else if (new->flags & IRQF_TRIGGER_MASK) {
1025 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1026 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1029 /* hope the handler works with current trigger mode */
1030 pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
1037 /* Reset broken irq detection when installing new handler */
1038 desc->irq_count = 0;
1039 desc->irqs_unhandled = 0;
1042 * Check whether we disabled the irq via the spurious handler
1043 * before. Reenable it and give it another chance.
1045 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1046 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1047 __enable_irq(desc, irq, false);
1050 raw_spin_unlock_irqrestore(&desc->lock, flags);
1053 * Strictly no need to wake it up, but hung_task complains
1054 * when no hard interrupt wakes the thread up.
1057 wake_up_process(new->thread);
1059 register_irq_proc(irq, desc);
1061 register_handler_proc(irq, new);
1066 #ifdef CONFIG_DEBUG_SHIRQ
1067 if (!(new->flags & IRQF_PROBE_SHARED)) {
1068 printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
1070 printk(KERN_ERR "current handler: %s\n", old_name);
1077 raw_spin_unlock_irqrestore(&desc->lock, flags);
1078 free_cpumask_var(mask);
1082 struct task_struct *t = new->thread;
1085 if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
1093 * setup_irq - setup an interrupt
1094 * @irq: Interrupt line to setup
1095 * @act: irqaction for the interrupt
1097 * Used to statically setup interrupts in the early boot process.
1099 int setup_irq(unsigned int irq, struct irqaction *act)
1102 struct irq_desc *desc = irq_to_desc(irq);
1104 chip_bus_lock(desc);
1105 retval = __setup_irq(irq, desc, act);
1106 chip_bus_sync_unlock(desc);
1110 EXPORT_SYMBOL_GPL(setup_irq);
1113 * Internal function to unregister an irqaction - used to free
1114 * regular and special interrupts that are part of the architecture.
1116 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1118 struct irq_desc *desc = irq_to_desc(irq);
1119 struct irqaction *action, **action_ptr;
1120 unsigned long flags;
1122 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1127 raw_spin_lock_irqsave(&desc->lock, flags);
1130 * There can be multiple actions per IRQ descriptor, find the right
1131 * one based on the dev_id:
1133 action_ptr = &desc->action;
1135 action = *action_ptr;
1138 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1139 raw_spin_unlock_irqrestore(&desc->lock, flags);
1144 if (action->dev_id == dev_id)
1146 action_ptr = &action->next;
1149 /* Found it - now remove it from the list of entries: */
1150 *action_ptr = action->next;
1152 /* Currently used only by UML, might disappear one day: */
1153 #ifdef CONFIG_IRQ_RELEASE_METHOD
1154 if (desc->irq_data.chip->release)
1155 desc->irq_data.chip->release(irq, dev_id);
1158 /* If this was the last handler, shut down the IRQ line: */
1163 /* make sure affinity_hint is cleaned up */
1164 if (WARN_ON_ONCE(desc->affinity_hint))
1165 desc->affinity_hint = NULL;
1168 raw_spin_unlock_irqrestore(&desc->lock, flags);
1170 unregister_handler_proc(irq, action);
1172 /* Make sure it's not being used on another CPU: */
1173 synchronize_irq(irq);
1175 #ifdef CONFIG_DEBUG_SHIRQ
1177 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1178 * event to happen even now it's being freed, so let's make sure that
1179 * is so by doing an extra call to the handler ....
1181 * ( We do this after actually deregistering it, to make sure that a
1182 * 'real' IRQ doesn't run in * parallel with our fake. )
1184 if (action->flags & IRQF_SHARED) {
1185 local_irq_save(flags);
1186 action->handler(irq, dev_id);
1187 local_irq_restore(flags);
1191 if (action->thread) {
1192 if (!test_bit(IRQTF_DIED, &action->thread_flags))
1193 kthread_stop(action->thread);
1194 put_task_struct(action->thread);
1201 * remove_irq - free an interrupt
1202 * @irq: Interrupt line to free
1203 * @act: irqaction for the interrupt
1205 * Used to remove interrupts statically setup by the early boot process.
1207 void remove_irq(unsigned int irq, struct irqaction *act)
1209 __free_irq(irq, act->dev_id);
1211 EXPORT_SYMBOL_GPL(remove_irq);
1214 * free_irq - free an interrupt allocated with request_irq
1215 * @irq: Interrupt line to free
1216 * @dev_id: Device identity to free
1218 * Remove an interrupt handler. The handler is removed and if the
1219 * interrupt line is no longer in use by any driver it is disabled.
1220 * On a shared IRQ the caller must ensure the interrupt is disabled
1221 * on the card it drives before calling this function. The function
1222 * does not return until any executing interrupts for this IRQ
1225 * This function must not be called from interrupt context.
1227 void free_irq(unsigned int irq, void *dev_id)
1229 struct irq_desc *desc = irq_to_desc(irq);
1235 if (WARN_ON(desc->affinity_notify))
1236 desc->affinity_notify = NULL;
1239 chip_bus_lock(desc);
1240 kfree(__free_irq(irq, dev_id));
1241 chip_bus_sync_unlock(desc);
1243 EXPORT_SYMBOL(free_irq);
1246 * request_threaded_irq - allocate an interrupt line
1247 * @irq: Interrupt line to allocate
1248 * @handler: Function to be called when the IRQ occurs.
1249 * Primary handler for threaded interrupts
1250 * If NULL and thread_fn != NULL the default
1251 * primary handler is installed
1252 * @thread_fn: Function called from the irq handler thread
1253 * If NULL, no irq thread is created
1254 * @irqflags: Interrupt type flags
1255 * @devname: An ascii name for the claiming device
1256 * @dev_id: A cookie passed back to the handler function
1258 * This call allocates interrupt resources and enables the
1259 * interrupt line and IRQ handling. From the point this
1260 * call is made your handler function may be invoked. Since
1261 * your handler function must clear any interrupt the board
1262 * raises, you must take care both to initialise your hardware
1263 * and to set up the interrupt handler in the right order.
1265 * If you want to set up a threaded irq handler for your device
1266 * then you need to supply @handler and @thread_fn. @handler ist
1267 * still called in hard interrupt context and has to check
1268 * whether the interrupt originates from the device. If yes it
1269 * needs to disable the interrupt on the device and return
1270 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1271 * @thread_fn. This split handler design is necessary to support
1272 * shared interrupts.
1274 * Dev_id must be globally unique. Normally the address of the
1275 * device data structure is used as the cookie. Since the handler
1276 * receives this value it makes sense to use it.
1278 * If your interrupt is shared you must pass a non NULL dev_id
1279 * as this is required when freeing the interrupt.
1283 * IRQF_SHARED Interrupt is shared
1284 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
1285 * IRQF_TRIGGER_* Specify active edge(s) or level
1288 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1289 irq_handler_t thread_fn, unsigned long irqflags,
1290 const char *devname, void *dev_id)
1292 struct irqaction *action;
1293 struct irq_desc *desc;
1297 * Sanity-check: shared interrupts must pass in a real dev-ID,
1298 * otherwise we'll have trouble later trying to figure out
1299 * which interrupt is which (messes up the interrupt freeing
1302 if ((irqflags & IRQF_SHARED) && !dev_id)
1305 desc = irq_to_desc(irq);
1309 if (!irq_settings_can_request(desc))
1315 handler = irq_default_primary_handler;
1318 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1322 action->handler = handler;
1323 action->thread_fn = thread_fn;
1324 action->flags = irqflags;
1325 action->name = devname;
1326 action->dev_id = dev_id;
1328 chip_bus_lock(desc);
1329 retval = __setup_irq(irq, desc, action);
1330 chip_bus_sync_unlock(desc);
1335 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1336 if (!retval && (irqflags & IRQF_SHARED)) {
1338 * It's a shared IRQ -- the driver ought to be prepared for it
1339 * to happen immediately, so let's make sure....
1340 * We disable the irq to make sure that a 'real' IRQ doesn't
1341 * run in parallel with our fake.
1343 unsigned long flags;
1346 local_irq_save(flags);
1348 handler(irq, dev_id);
1350 local_irq_restore(flags);
1356 EXPORT_SYMBOL(request_threaded_irq);
1359 * request_any_context_irq - allocate an interrupt line
1360 * @irq: Interrupt line to allocate
1361 * @handler: Function to be called when the IRQ occurs.
1362 * Threaded handler for threaded interrupts.
1363 * @flags: Interrupt type flags
1364 * @name: An ascii name for the claiming device
1365 * @dev_id: A cookie passed back to the handler function
1367 * This call allocates interrupt resources and enables the
1368 * interrupt line and IRQ handling. It selects either a
1369 * hardirq or threaded handling method depending on the
1372 * On failure, it returns a negative value. On success,
1373 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1375 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1376 unsigned long flags, const char *name, void *dev_id)
1378 struct irq_desc *desc = irq_to_desc(irq);
1384 if (irq_settings_is_nested_thread(desc)) {
1385 ret = request_threaded_irq(irq, NULL, handler,
1386 flags, name, dev_id);
1387 return !ret ? IRQC_IS_NESTED : ret;
1390 ret = request_irq(irq, handler, flags, name, dev_id);
1391 return !ret ? IRQC_IS_HARDIRQ : ret;
1393 EXPORT_SYMBOL_GPL(request_any_context_irq);