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 #define pr_fmt(fmt) "genirq: " fmt
12 #include <linux/irq.h>
13 #include <linux/kthread.h>
14 #include <linux/module.h>
15 #include <linux/random.h>
16 #include <linux/interrupt.h>
17 #include <linux/slab.h>
18 #include <linux/sched.h>
19 #include <linux/sched/rt.h>
20 #include <linux/task_work.h>
22 #include "internals.h"
24 #ifdef CONFIG_IRQ_FORCED_THREADING
25 __read_mostly bool force_irqthreads;
27 static int __init setup_forced_irqthreads(char *arg)
29 force_irqthreads = true;
32 early_param("threadirqs", setup_forced_irqthreads);
35 static void __synchronize_hardirq(struct irq_desc *desc)
43 * Wait until we're out of the critical section. This might
44 * give the wrong answer due to the lack of memory barriers.
46 while (irqd_irq_inprogress(&desc->irq_data))
49 /* Ok, that indicated we're done: double-check carefully. */
50 raw_spin_lock_irqsave(&desc->lock, flags);
51 inprogress = irqd_irq_inprogress(&desc->irq_data);
52 raw_spin_unlock_irqrestore(&desc->lock, flags);
54 /* Oops, that failed? */
59 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
60 * @irq: interrupt number to wait for
62 * This function waits for any pending hard IRQ handlers for this
63 * interrupt to complete before returning. If you use this
64 * function while holding a resource the IRQ handler may need you
65 * will deadlock. It does not take associated threaded handlers
68 * Do not use this for shutdown scenarios where you must be sure
69 * that all parts (hardirq and threaded handler) have completed.
71 * This function may be called - with care - from IRQ context.
73 void synchronize_hardirq(unsigned int irq)
75 struct irq_desc *desc = irq_to_desc(irq);
78 __synchronize_hardirq(desc);
80 EXPORT_SYMBOL(synchronize_hardirq);
83 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
84 * @irq: interrupt number to wait for
86 * This function waits for any pending IRQ handlers for this interrupt
87 * to complete before returning. If you use this function while
88 * holding a resource the IRQ handler may need you will deadlock.
90 * This function may be called - with care - from IRQ context.
92 void synchronize_irq(unsigned int irq)
94 struct irq_desc *desc = irq_to_desc(irq);
97 __synchronize_hardirq(desc);
99 * We made sure that no hardirq handler is
100 * running. Now verify that no threaded handlers are
103 wait_event(desc->wait_for_threads,
104 !atomic_read(&desc->threads_active));
107 EXPORT_SYMBOL(synchronize_irq);
110 cpumask_var_t irq_default_affinity;
113 * irq_can_set_affinity - Check if the affinity of a given irq can be set
114 * @irq: Interrupt to check
117 int irq_can_set_affinity(unsigned int irq)
119 struct irq_desc *desc = irq_to_desc(irq);
121 if (!desc || !irqd_can_balance(&desc->irq_data) ||
122 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
129 * irq_set_thread_affinity - Notify irq threads to adjust affinity
130 * @desc: irq descriptor which has affitnity changed
132 * We just set IRQTF_AFFINITY and delegate the affinity setting
133 * to the interrupt thread itself. We can not call
134 * set_cpus_allowed_ptr() here as we hold desc->lock and this
135 * code can be called from hard interrupt context.
137 void irq_set_thread_affinity(struct irq_desc *desc)
139 struct irqaction *action = desc->action;
143 set_bit(IRQTF_AFFINITY, &action->thread_flags);
144 action = action->next;
148 #ifdef CONFIG_GENERIC_PENDING_IRQ
149 static inline bool irq_can_move_pcntxt(struct irq_data *data)
151 return irqd_can_move_in_process_context(data);
153 static inline bool irq_move_pending(struct irq_data *data)
155 return irqd_is_setaffinity_pending(data);
158 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
160 cpumask_copy(desc->pending_mask, mask);
163 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
165 cpumask_copy(mask, desc->pending_mask);
168 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
169 static inline bool irq_move_pending(struct irq_data *data) { return false; }
171 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
173 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
176 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
179 struct irq_desc *desc = irq_data_to_desc(data);
180 struct irq_chip *chip = irq_data_get_irq_chip(data);
183 ret = chip->irq_set_affinity(data, mask, force);
185 case IRQ_SET_MASK_OK:
186 case IRQ_SET_MASK_OK_DONE:
187 cpumask_copy(data->affinity, mask);
188 case IRQ_SET_MASK_OK_NOCOPY:
189 irq_set_thread_affinity(desc);
196 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
199 struct irq_chip *chip = irq_data_get_irq_chip(data);
200 struct irq_desc *desc = irq_data_to_desc(data);
203 if (!chip || !chip->irq_set_affinity)
206 if (irq_can_move_pcntxt(data)) {
207 ret = irq_do_set_affinity(data, mask, force);
209 irqd_set_move_pending(data);
210 irq_copy_pending(desc, mask);
213 if (desc->affinity_notify) {
214 kref_get(&desc->affinity_notify->kref);
215 schedule_work(&desc->affinity_notify->work);
217 irqd_set(data, IRQD_AFFINITY_SET);
222 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
224 struct irq_desc *desc = irq_to_desc(irq);
231 raw_spin_lock_irqsave(&desc->lock, flags);
232 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
233 raw_spin_unlock_irqrestore(&desc->lock, flags);
237 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
240 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
244 desc->affinity_hint = m;
245 irq_put_desc_unlock(desc, flags);
246 /* set the initial affinity to prevent every interrupt being on CPU0 */
247 __irq_set_affinity(irq, m, false);
250 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
252 static void irq_affinity_notify(struct work_struct *work)
254 struct irq_affinity_notify *notify =
255 container_of(work, struct irq_affinity_notify, work);
256 struct irq_desc *desc = irq_to_desc(notify->irq);
257 cpumask_var_t cpumask;
260 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
263 raw_spin_lock_irqsave(&desc->lock, flags);
264 if (irq_move_pending(&desc->irq_data))
265 irq_get_pending(cpumask, desc);
267 cpumask_copy(cpumask, desc->irq_data.affinity);
268 raw_spin_unlock_irqrestore(&desc->lock, flags);
270 notify->notify(notify, cpumask);
272 free_cpumask_var(cpumask);
274 kref_put(¬ify->kref, notify->release);
278 * irq_set_affinity_notifier - control notification of IRQ affinity changes
279 * @irq: Interrupt for which to enable/disable notification
280 * @notify: Context for notification, or %NULL to disable
281 * notification. Function pointers must be initialised;
282 * the other fields will be initialised by this function.
284 * Must be called in process context. Notification may only be enabled
285 * after the IRQ is allocated and must be disabled before the IRQ is
286 * freed using free_irq().
289 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
291 struct irq_desc *desc = irq_to_desc(irq);
292 struct irq_affinity_notify *old_notify;
295 /* The release function is promised process context */
301 /* Complete initialisation of *notify */
304 kref_init(¬ify->kref);
305 INIT_WORK(¬ify->work, irq_affinity_notify);
308 raw_spin_lock_irqsave(&desc->lock, flags);
309 old_notify = desc->affinity_notify;
310 desc->affinity_notify = notify;
311 raw_spin_unlock_irqrestore(&desc->lock, flags);
314 kref_put(&old_notify->kref, old_notify->release);
318 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
320 #ifndef CONFIG_AUTO_IRQ_AFFINITY
322 * Generic version of the affinity autoselector.
325 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
327 struct cpumask *set = irq_default_affinity;
328 int node = desc->irq_data.node;
330 /* Excludes PER_CPU and NO_BALANCE interrupts */
331 if (!irq_can_set_affinity(irq))
335 * Preserve an userspace affinity setup, but make sure that
336 * one of the targets is online.
338 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
339 if (cpumask_intersects(desc->irq_data.affinity,
341 set = desc->irq_data.affinity;
343 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
346 cpumask_and(mask, cpu_online_mask, set);
347 if (node != NUMA_NO_NODE) {
348 const struct cpumask *nodemask = cpumask_of_node(node);
350 /* make sure at least one of the cpus in nodemask is online */
351 if (cpumask_intersects(mask, nodemask))
352 cpumask_and(mask, mask, nodemask);
354 irq_do_set_affinity(&desc->irq_data, mask, false);
359 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
361 return irq_select_affinity(irq);
366 * Called when affinity is set via /proc/irq
368 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
370 struct irq_desc *desc = irq_to_desc(irq);
374 raw_spin_lock_irqsave(&desc->lock, flags);
375 ret = setup_affinity(irq, desc, mask);
376 raw_spin_unlock_irqrestore(&desc->lock, flags);
382 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
388 void __disable_irq(struct irq_desc *desc, unsigned int irq)
394 static int __disable_irq_nosync(unsigned int irq)
397 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
401 __disable_irq(desc, irq);
402 irq_put_desc_busunlock(desc, flags);
407 * disable_irq_nosync - disable an irq without waiting
408 * @irq: Interrupt to disable
410 * Disable the selected interrupt line. Disables and Enables are
412 * Unlike disable_irq(), this function does not ensure existing
413 * instances of the IRQ handler have completed before returning.
415 * This function may be called from IRQ context.
417 void disable_irq_nosync(unsigned int irq)
419 __disable_irq_nosync(irq);
421 EXPORT_SYMBOL(disable_irq_nosync);
424 * disable_irq - disable an irq and wait for completion
425 * @irq: Interrupt to disable
427 * Disable the selected interrupt line. Enables and Disables are
429 * This function waits for any pending IRQ handlers for this interrupt
430 * to complete before returning. If you use this function while
431 * holding a resource the IRQ handler may need you will deadlock.
433 * This function may be called - with care - from IRQ context.
435 void disable_irq(unsigned int irq)
437 if (!__disable_irq_nosync(irq))
438 synchronize_irq(irq);
440 EXPORT_SYMBOL(disable_irq);
442 void __enable_irq(struct irq_desc *desc, unsigned int irq)
444 switch (desc->depth) {
447 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
450 if (desc->istate & IRQS_SUSPENDED)
452 /* Prevent probing on this irq: */
453 irq_settings_set_noprobe(desc);
455 check_irq_resend(desc, irq);
464 * enable_irq - enable handling of an irq
465 * @irq: Interrupt to enable
467 * Undoes the effect of one call to disable_irq(). If this
468 * matches the last disable, processing of interrupts on this
469 * IRQ line is re-enabled.
471 * This function may be called from IRQ context only when
472 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
474 void enable_irq(unsigned int irq)
477 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
481 if (WARN(!desc->irq_data.chip,
482 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
485 __enable_irq(desc, irq);
487 irq_put_desc_busunlock(desc, flags);
489 EXPORT_SYMBOL(enable_irq);
491 static int set_irq_wake_real(unsigned int irq, unsigned int on)
493 struct irq_desc *desc = irq_to_desc(irq);
496 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
499 if (desc->irq_data.chip->irq_set_wake)
500 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
506 * irq_set_irq_wake - control irq power management wakeup
507 * @irq: interrupt to control
508 * @on: enable/disable power management wakeup
510 * Enable/disable power management wakeup mode, which is
511 * disabled by default. Enables and disables must match,
512 * just as they match for non-wakeup mode support.
514 * Wakeup mode lets this IRQ wake the system from sleep
515 * states like "suspend to RAM".
517 int irq_set_irq_wake(unsigned int irq, unsigned int on)
520 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
526 /* wakeup-capable irqs can be shared between drivers that
527 * don't need to have the same sleep mode behaviors.
530 if (desc->wake_depth++ == 0) {
531 ret = set_irq_wake_real(irq, on);
533 desc->wake_depth = 0;
535 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
538 if (desc->wake_depth == 0) {
539 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
540 } else if (--desc->wake_depth == 0) {
541 ret = set_irq_wake_real(irq, on);
543 desc->wake_depth = 1;
545 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
548 irq_put_desc_busunlock(desc, flags);
551 EXPORT_SYMBOL(irq_set_irq_wake);
554 * Internal function that tells the architecture code whether a
555 * particular irq has been exclusively allocated or is available
558 int can_request_irq(unsigned int irq, unsigned long irqflags)
561 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
567 if (irq_settings_can_request(desc)) {
569 irqflags & desc->action->flags & IRQF_SHARED)
572 irq_put_desc_unlock(desc, flags);
576 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
579 struct irq_chip *chip = desc->irq_data.chip;
582 if (!chip || !chip->irq_set_type) {
584 * IRQF_TRIGGER_* but the PIC does not support multiple
587 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
588 chip ? (chip->name ? : "unknown") : "unknown");
592 flags &= IRQ_TYPE_SENSE_MASK;
594 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
595 if (!irqd_irq_masked(&desc->irq_data))
597 if (!irqd_irq_disabled(&desc->irq_data))
601 /* caller masked out all except trigger mode flags */
602 ret = chip->irq_set_type(&desc->irq_data, flags);
605 case IRQ_SET_MASK_OK:
606 case IRQ_SET_MASK_OK_DONE:
607 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
608 irqd_set(&desc->irq_data, flags);
610 case IRQ_SET_MASK_OK_NOCOPY:
611 flags = irqd_get_trigger_type(&desc->irq_data);
612 irq_settings_set_trigger_mask(desc, flags);
613 irqd_clear(&desc->irq_data, IRQD_LEVEL);
614 irq_settings_clr_level(desc);
615 if (flags & IRQ_TYPE_LEVEL_MASK) {
616 irq_settings_set_level(desc);
617 irqd_set(&desc->irq_data, IRQD_LEVEL);
623 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
624 flags, irq, chip->irq_set_type);
631 #ifdef CONFIG_HARDIRQS_SW_RESEND
632 int irq_set_parent(int irq, int parent_irq)
635 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
640 desc->parent_irq = parent_irq;
642 irq_put_desc_unlock(desc, flags);
648 * Default primary interrupt handler for threaded interrupts. Is
649 * assigned as primary handler when request_threaded_irq is called
650 * with handler == NULL. Useful for oneshot interrupts.
652 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
654 return IRQ_WAKE_THREAD;
658 * Primary handler for nested threaded interrupts. Should never be
661 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
663 WARN(1, "Primary handler called for nested irq %d\n", irq);
667 static int irq_wait_for_interrupt(struct irqaction *action)
669 set_current_state(TASK_INTERRUPTIBLE);
671 while (!kthread_should_stop()) {
673 if (test_and_clear_bit(IRQTF_RUNTHREAD,
674 &action->thread_flags)) {
675 __set_current_state(TASK_RUNNING);
679 set_current_state(TASK_INTERRUPTIBLE);
681 __set_current_state(TASK_RUNNING);
686 * Oneshot interrupts keep the irq line masked until the threaded
687 * handler finished. unmask if the interrupt has not been disabled and
690 static void irq_finalize_oneshot(struct irq_desc *desc,
691 struct irqaction *action)
693 if (!(desc->istate & IRQS_ONESHOT))
697 raw_spin_lock_irq(&desc->lock);
700 * Implausible though it may be we need to protect us against
701 * the following scenario:
703 * The thread is faster done than the hard interrupt handler
704 * on the other CPU. If we unmask the irq line then the
705 * interrupt can come in again and masks the line, leaves due
706 * to IRQS_INPROGRESS and the irq line is masked forever.
708 * This also serializes the state of shared oneshot handlers
709 * versus "desc->threads_onehsot |= action->thread_mask;" in
710 * irq_wake_thread(). See the comment there which explains the
713 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
714 raw_spin_unlock_irq(&desc->lock);
715 chip_bus_sync_unlock(desc);
721 * Now check again, whether the thread should run. Otherwise
722 * we would clear the threads_oneshot bit of this thread which
725 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
728 desc->threads_oneshot &= ~action->thread_mask;
730 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
731 irqd_irq_masked(&desc->irq_data))
732 unmask_threaded_irq(desc);
735 raw_spin_unlock_irq(&desc->lock);
736 chip_bus_sync_unlock(desc);
741 * Check whether we need to change the affinity of the interrupt thread.
744 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
749 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
753 * In case we are out of memory we set IRQTF_AFFINITY again and
754 * try again next time
756 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
757 set_bit(IRQTF_AFFINITY, &action->thread_flags);
761 raw_spin_lock_irq(&desc->lock);
763 * This code is triggered unconditionally. Check the affinity
764 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
766 if (desc->irq_data.affinity)
767 cpumask_copy(mask, desc->irq_data.affinity);
770 raw_spin_unlock_irq(&desc->lock);
773 set_cpus_allowed_ptr(current, mask);
774 free_cpumask_var(mask);
778 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
782 * Interrupts which are not explicitely requested as threaded
783 * interrupts rely on the implicit bh/preempt disable of the hard irq
784 * context. So we need to disable bh here to avoid deadlocks and other
788 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
793 ret = action->thread_fn(action->irq, action->dev_id);
794 irq_finalize_oneshot(desc, action);
800 * Interrupts explicitly requested as threaded interrupts want to be
801 * preemtible - many of them need to sleep and wait for slow busses to
804 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
805 struct irqaction *action)
809 ret = action->thread_fn(action->irq, action->dev_id);
810 irq_finalize_oneshot(desc, action);
814 static void wake_threads_waitq(struct irq_desc *desc)
816 if (atomic_dec_and_test(&desc->threads_active))
817 wake_up(&desc->wait_for_threads);
820 static void irq_thread_dtor(struct callback_head *unused)
822 struct task_struct *tsk = current;
823 struct irq_desc *desc;
824 struct irqaction *action;
826 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
829 action = kthread_data(tsk);
831 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
832 tsk->comm, tsk->pid, action->irq);
835 desc = irq_to_desc(action->irq);
837 * If IRQTF_RUNTHREAD is set, we need to decrement
838 * desc->threads_active and wake possible waiters.
840 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
841 wake_threads_waitq(desc);
843 /* Prevent a stale desc->threads_oneshot */
844 irq_finalize_oneshot(desc, action);
848 * Interrupt handler thread
850 static int irq_thread(void *data)
852 struct callback_head on_exit_work;
853 struct irqaction *action = data;
854 struct irq_desc *desc = irq_to_desc(action->irq);
855 irqreturn_t (*handler_fn)(struct irq_desc *desc,
856 struct irqaction *action);
858 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
859 &action->thread_flags))
860 handler_fn = irq_forced_thread_fn;
862 handler_fn = irq_thread_fn;
864 init_task_work(&on_exit_work, irq_thread_dtor);
865 task_work_add(current, &on_exit_work, false);
867 irq_thread_check_affinity(desc, action);
869 while (!irq_wait_for_interrupt(action)) {
870 irqreturn_t action_ret;
872 irq_thread_check_affinity(desc, action);
874 action_ret = handler_fn(desc, action);
875 if (action_ret == IRQ_HANDLED)
876 atomic_inc(&desc->threads_handled);
878 wake_threads_waitq(desc);
882 * This is the regular exit path. __free_irq() is stopping the
883 * thread via kthread_stop() after calling
884 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
885 * oneshot mask bit can be set. We cannot verify that as we
886 * cannot touch the oneshot mask at this point anymore as
887 * __setup_irq() might have given out currents thread_mask
890 task_work_cancel(current, irq_thread_dtor);
895 * irq_wake_thread - wake the irq thread for the action identified by dev_id
896 * @irq: Interrupt line
897 * @dev_id: Device identity for which the thread should be woken
900 void irq_wake_thread(unsigned int irq, void *dev_id)
902 struct irq_desc *desc = irq_to_desc(irq);
903 struct irqaction *action;
906 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
909 raw_spin_lock_irqsave(&desc->lock, flags);
910 for (action = desc->action; action; action = action->next) {
911 if (action->dev_id == dev_id) {
913 __irq_wake_thread(desc, action);
917 raw_spin_unlock_irqrestore(&desc->lock, flags);
919 EXPORT_SYMBOL_GPL(irq_wake_thread);
921 static void irq_setup_forced_threading(struct irqaction *new)
923 if (!force_irqthreads)
925 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
928 new->flags |= IRQF_ONESHOT;
930 if (!new->thread_fn) {
931 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
932 new->thread_fn = new->handler;
933 new->handler = irq_default_primary_handler;
937 static int irq_request_resources(struct irq_desc *desc)
939 struct irq_data *d = &desc->irq_data;
940 struct irq_chip *c = d->chip;
942 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
945 static void irq_release_resources(struct irq_desc *desc)
947 struct irq_data *d = &desc->irq_data;
948 struct irq_chip *c = d->chip;
950 if (c->irq_release_resources)
951 c->irq_release_resources(d);
955 * Internal function to register an irqaction - typically used to
956 * allocate special interrupts that are part of the architecture.
959 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
961 struct irqaction *old, **old_ptr;
962 unsigned long flags, thread_mask = 0;
963 int ret, nested, shared = 0;
969 if (desc->irq_data.chip == &no_irq_chip)
971 if (!try_module_get(desc->owner))
975 * Check whether the interrupt nests into another interrupt
978 nested = irq_settings_is_nested_thread(desc);
980 if (!new->thread_fn) {
985 * Replace the primary handler which was provided from
986 * the driver for non nested interrupt handling by the
987 * dummy function which warns when called.
989 new->handler = irq_nested_primary_handler;
991 if (irq_settings_can_thread(desc))
992 irq_setup_forced_threading(new);
996 * Create a handler thread when a thread function is supplied
997 * and the interrupt does not nest into another interrupt
1000 if (new->thread_fn && !nested) {
1001 struct task_struct *t;
1002 static const struct sched_param param = {
1003 .sched_priority = MAX_USER_RT_PRIO/2,
1006 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1013 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1016 * We keep the reference to the task struct even if
1017 * the thread dies to avoid that the interrupt code
1018 * references an already freed task_struct.
1023 * Tell the thread to set its affinity. This is
1024 * important for shared interrupt handlers as we do
1025 * not invoke setup_affinity() for the secondary
1026 * handlers as everything is already set up. Even for
1027 * interrupts marked with IRQF_NO_BALANCE this is
1028 * correct as we want the thread to move to the cpu(s)
1029 * on which the requesting code placed the interrupt.
1031 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1034 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1040 * Drivers are often written to work w/o knowledge about the
1041 * underlying irq chip implementation, so a request for a
1042 * threaded irq without a primary hard irq context handler
1043 * requires the ONESHOT flag to be set. Some irq chips like
1044 * MSI based interrupts are per se one shot safe. Check the
1045 * chip flags, so we can avoid the unmask dance at the end of
1046 * the threaded handler for those.
1048 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1049 new->flags &= ~IRQF_ONESHOT;
1052 * The following block of code has to be executed atomically
1054 raw_spin_lock_irqsave(&desc->lock, flags);
1055 old_ptr = &desc->action;
1059 * Can't share interrupts unless both agree to and are
1060 * the same type (level, edge, polarity). So both flag
1061 * fields must have IRQF_SHARED set and the bits which
1062 * set the trigger type must match. Also all must
1065 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1066 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1067 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1070 /* All handlers must agree on per-cpuness */
1071 if ((old->flags & IRQF_PERCPU) !=
1072 (new->flags & IRQF_PERCPU))
1075 /* add new interrupt at end of irq queue */
1078 * Or all existing action->thread_mask bits,
1079 * so we can find the next zero bit for this
1082 thread_mask |= old->thread_mask;
1083 old_ptr = &old->next;
1090 * Setup the thread mask for this irqaction for ONESHOT. For
1091 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1092 * conditional in irq_wake_thread().
1094 if (new->flags & IRQF_ONESHOT) {
1096 * Unlikely to have 32 resp 64 irqs sharing one line,
1099 if (thread_mask == ~0UL) {
1104 * The thread_mask for the action is or'ed to
1105 * desc->thread_active to indicate that the
1106 * IRQF_ONESHOT thread handler has been woken, but not
1107 * yet finished. The bit is cleared when a thread
1108 * completes. When all threads of a shared interrupt
1109 * line have completed desc->threads_active becomes
1110 * zero and the interrupt line is unmasked. See
1111 * handle.c:irq_wake_thread() for further information.
1113 * If no thread is woken by primary (hard irq context)
1114 * interrupt handlers, then desc->threads_active is
1115 * also checked for zero to unmask the irq line in the
1116 * affected hard irq flow handlers
1117 * (handle_[fasteoi|level]_irq).
1119 * The new action gets the first zero bit of
1120 * thread_mask assigned. See the loop above which or's
1121 * all existing action->thread_mask bits.
1123 new->thread_mask = 1 << ffz(thread_mask);
1125 } else if (new->handler == irq_default_primary_handler &&
1126 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1128 * The interrupt was requested with handler = NULL, so
1129 * we use the default primary handler for it. But it
1130 * does not have the oneshot flag set. In combination
1131 * with level interrupts this is deadly, because the
1132 * default primary handler just wakes the thread, then
1133 * the irq lines is reenabled, but the device still
1134 * has the level irq asserted. Rinse and repeat....
1136 * While this works for edge type interrupts, we play
1137 * it safe and reject unconditionally because we can't
1138 * say for sure which type this interrupt really
1139 * has. The type flags are unreliable as the
1140 * underlying chip implementation can override them.
1142 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1149 ret = irq_request_resources(desc);
1151 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1152 new->name, irq, desc->irq_data.chip->name);
1156 init_waitqueue_head(&desc->wait_for_threads);
1158 /* Setup the type (level, edge polarity) if configured: */
1159 if (new->flags & IRQF_TRIGGER_MASK) {
1160 ret = __irq_set_trigger(desc, irq,
1161 new->flags & IRQF_TRIGGER_MASK);
1167 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1168 IRQS_ONESHOT | IRQS_WAITING);
1169 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1171 if (new->flags & IRQF_PERCPU) {
1172 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1173 irq_settings_set_per_cpu(desc);
1176 if (new->flags & IRQF_ONESHOT)
1177 desc->istate |= IRQS_ONESHOT;
1179 if (irq_settings_can_autoenable(desc))
1180 irq_startup(desc, true);
1182 /* Undo nested disables: */
1185 /* Exclude IRQ from balancing if requested */
1186 if (new->flags & IRQF_NOBALANCING) {
1187 irq_settings_set_no_balancing(desc);
1188 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1191 /* Set default affinity mask once everything is setup */
1192 setup_affinity(irq, desc, mask);
1194 } else if (new->flags & IRQF_TRIGGER_MASK) {
1195 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1196 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1199 /* hope the handler works with current trigger mode */
1200 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1207 irq_pm_install_action(desc, new);
1209 /* Reset broken irq detection when installing new handler */
1210 desc->irq_count = 0;
1211 desc->irqs_unhandled = 0;
1214 * Check whether we disabled the irq via the spurious handler
1215 * before. Reenable it and give it another chance.
1217 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1218 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1219 __enable_irq(desc, irq);
1222 raw_spin_unlock_irqrestore(&desc->lock, flags);
1225 * Strictly no need to wake it up, but hung_task complains
1226 * when no hard interrupt wakes the thread up.
1229 wake_up_process(new->thread);
1231 register_irq_proc(irq, desc);
1233 register_handler_proc(irq, new);
1234 free_cpumask_var(mask);
1239 if (!(new->flags & IRQF_PROBE_SHARED)) {
1240 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1241 irq, new->flags, new->name, old->flags, old->name);
1242 #ifdef CONFIG_DEBUG_SHIRQ
1249 raw_spin_unlock_irqrestore(&desc->lock, flags);
1250 free_cpumask_var(mask);
1254 struct task_struct *t = new->thread;
1261 module_put(desc->owner);
1266 * setup_irq - setup an interrupt
1267 * @irq: Interrupt line to setup
1268 * @act: irqaction for the interrupt
1270 * Used to statically setup interrupts in the early boot process.
1272 int setup_irq(unsigned int irq, struct irqaction *act)
1275 struct irq_desc *desc = irq_to_desc(irq);
1277 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1279 chip_bus_lock(desc);
1280 retval = __setup_irq(irq, desc, act);
1281 chip_bus_sync_unlock(desc);
1285 EXPORT_SYMBOL_GPL(setup_irq);
1288 * Internal function to unregister an irqaction - used to free
1289 * regular and special interrupts that are part of the architecture.
1291 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1293 struct irq_desc *desc = irq_to_desc(irq);
1294 struct irqaction *action, **action_ptr;
1295 unsigned long flags;
1297 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1302 raw_spin_lock_irqsave(&desc->lock, flags);
1305 * There can be multiple actions per IRQ descriptor, find the right
1306 * one based on the dev_id:
1308 action_ptr = &desc->action;
1310 action = *action_ptr;
1313 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1314 raw_spin_unlock_irqrestore(&desc->lock, flags);
1319 if (action->dev_id == dev_id)
1321 action_ptr = &action->next;
1324 /* Found it - now remove it from the list of entries: */
1325 *action_ptr = action->next;
1327 irq_pm_remove_action(desc, action);
1329 /* If this was the last handler, shut down the IRQ line: */
1330 if (!desc->action) {
1332 irq_release_resources(desc);
1336 /* make sure affinity_hint is cleaned up */
1337 if (WARN_ON_ONCE(desc->affinity_hint))
1338 desc->affinity_hint = NULL;
1341 raw_spin_unlock_irqrestore(&desc->lock, flags);
1343 unregister_handler_proc(irq, action);
1345 /* Make sure it's not being used on another CPU: */
1346 synchronize_irq(irq);
1348 #ifdef CONFIG_DEBUG_SHIRQ
1350 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1351 * event to happen even now it's being freed, so let's make sure that
1352 * is so by doing an extra call to the handler ....
1354 * ( We do this after actually deregistering it, to make sure that a
1355 * 'real' IRQ doesn't run in * parallel with our fake. )
1357 if (action->flags & IRQF_SHARED) {
1358 local_irq_save(flags);
1359 action->handler(irq, dev_id);
1360 local_irq_restore(flags);
1364 if (action->thread) {
1365 kthread_stop(action->thread);
1366 put_task_struct(action->thread);
1369 module_put(desc->owner);
1374 * remove_irq - free an interrupt
1375 * @irq: Interrupt line to free
1376 * @act: irqaction for the interrupt
1378 * Used to remove interrupts statically setup by the early boot process.
1380 void remove_irq(unsigned int irq, struct irqaction *act)
1382 struct irq_desc *desc = irq_to_desc(irq);
1384 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1385 __free_irq(irq, act->dev_id);
1387 EXPORT_SYMBOL_GPL(remove_irq);
1390 * free_irq - free an interrupt allocated with request_irq
1391 * @irq: Interrupt line to free
1392 * @dev_id: Device identity to free
1394 * Remove an interrupt handler. The handler is removed and if the
1395 * interrupt line is no longer in use by any driver it is disabled.
1396 * On a shared IRQ the caller must ensure the interrupt is disabled
1397 * on the card it drives before calling this function. The function
1398 * does not return until any executing interrupts for this IRQ
1401 * This function must not be called from interrupt context.
1403 void free_irq(unsigned int irq, void *dev_id)
1405 struct irq_desc *desc = irq_to_desc(irq);
1407 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1411 if (WARN_ON(desc->affinity_notify))
1412 desc->affinity_notify = NULL;
1415 chip_bus_lock(desc);
1416 kfree(__free_irq(irq, dev_id));
1417 chip_bus_sync_unlock(desc);
1419 EXPORT_SYMBOL(free_irq);
1422 * request_threaded_irq - allocate an interrupt line
1423 * @irq: Interrupt line to allocate
1424 * @handler: Function to be called when the IRQ occurs.
1425 * Primary handler for threaded interrupts
1426 * If NULL and thread_fn != NULL the default
1427 * primary handler is installed
1428 * @thread_fn: Function called from the irq handler thread
1429 * If NULL, no irq thread is created
1430 * @irqflags: Interrupt type flags
1431 * @devname: An ascii name for the claiming device
1432 * @dev_id: A cookie passed back to the handler function
1434 * This call allocates interrupt resources and enables the
1435 * interrupt line and IRQ handling. From the point this
1436 * call is made your handler function may be invoked. Since
1437 * your handler function must clear any interrupt the board
1438 * raises, you must take care both to initialise your hardware
1439 * and to set up the interrupt handler in the right order.
1441 * If you want to set up a threaded irq handler for your device
1442 * then you need to supply @handler and @thread_fn. @handler is
1443 * still called in hard interrupt context and has to check
1444 * whether the interrupt originates from the device. If yes it
1445 * needs to disable the interrupt on the device and return
1446 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1447 * @thread_fn. This split handler design is necessary to support
1448 * shared interrupts.
1450 * Dev_id must be globally unique. Normally the address of the
1451 * device data structure is used as the cookie. Since the handler
1452 * receives this value it makes sense to use it.
1454 * If your interrupt is shared you must pass a non NULL dev_id
1455 * as this is required when freeing the interrupt.
1459 * IRQF_SHARED Interrupt is shared
1460 * IRQF_TRIGGER_* Specify active edge(s) or level
1463 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1464 irq_handler_t thread_fn, unsigned long irqflags,
1465 const char *devname, void *dev_id)
1467 struct irqaction *action;
1468 struct irq_desc *desc;
1472 * Sanity-check: shared interrupts must pass in a real dev-ID,
1473 * otherwise we'll have trouble later trying to figure out
1474 * which interrupt is which (messes up the interrupt freeing
1477 if ((irqflags & IRQF_SHARED) && !dev_id)
1480 desc = irq_to_desc(irq);
1484 if (!irq_settings_can_request(desc) ||
1485 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1491 handler = irq_default_primary_handler;
1494 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1498 action->handler = handler;
1499 action->thread_fn = thread_fn;
1500 action->flags = irqflags;
1501 action->name = devname;
1502 action->dev_id = dev_id;
1504 chip_bus_lock(desc);
1505 retval = __setup_irq(irq, desc, action);
1506 chip_bus_sync_unlock(desc);
1511 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1512 if (!retval && (irqflags & IRQF_SHARED)) {
1514 * It's a shared IRQ -- the driver ought to be prepared for it
1515 * to happen immediately, so let's make sure....
1516 * We disable the irq to make sure that a 'real' IRQ doesn't
1517 * run in parallel with our fake.
1519 unsigned long flags;
1522 local_irq_save(flags);
1524 handler(irq, dev_id);
1526 local_irq_restore(flags);
1532 EXPORT_SYMBOL(request_threaded_irq);
1535 * request_any_context_irq - allocate an interrupt line
1536 * @irq: Interrupt line to allocate
1537 * @handler: Function to be called when the IRQ occurs.
1538 * Threaded handler for threaded interrupts.
1539 * @flags: Interrupt type flags
1540 * @name: An ascii name for the claiming device
1541 * @dev_id: A cookie passed back to the handler function
1543 * This call allocates interrupt resources and enables the
1544 * interrupt line and IRQ handling. It selects either a
1545 * hardirq or threaded handling method depending on the
1548 * On failure, it returns a negative value. On success,
1549 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1551 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1552 unsigned long flags, const char *name, void *dev_id)
1554 struct irq_desc *desc = irq_to_desc(irq);
1560 if (irq_settings_is_nested_thread(desc)) {
1561 ret = request_threaded_irq(irq, NULL, handler,
1562 flags, name, dev_id);
1563 return !ret ? IRQC_IS_NESTED : ret;
1566 ret = request_irq(irq, handler, flags, name, dev_id);
1567 return !ret ? IRQC_IS_HARDIRQ : ret;
1569 EXPORT_SYMBOL_GPL(request_any_context_irq);
1571 void enable_percpu_irq(unsigned int irq, unsigned int type)
1573 unsigned int cpu = smp_processor_id();
1574 unsigned long flags;
1575 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1580 type &= IRQ_TYPE_SENSE_MASK;
1581 if (type != IRQ_TYPE_NONE) {
1584 ret = __irq_set_trigger(desc, irq, type);
1587 WARN(1, "failed to set type for IRQ%d\n", irq);
1592 irq_percpu_enable(desc, cpu);
1594 irq_put_desc_unlock(desc, flags);
1596 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1598 void disable_percpu_irq(unsigned int irq)
1600 unsigned int cpu = smp_processor_id();
1601 unsigned long flags;
1602 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1607 irq_percpu_disable(desc, cpu);
1608 irq_put_desc_unlock(desc, flags);
1610 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1613 * Internal function to unregister a percpu irqaction.
1615 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1617 struct irq_desc *desc = irq_to_desc(irq);
1618 struct irqaction *action;
1619 unsigned long flags;
1621 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1626 raw_spin_lock_irqsave(&desc->lock, flags);
1628 action = desc->action;
1629 if (!action || action->percpu_dev_id != dev_id) {
1630 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1634 if (!cpumask_empty(desc->percpu_enabled)) {
1635 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1636 irq, cpumask_first(desc->percpu_enabled));
1640 /* Found it - now remove it from the list of entries: */
1641 desc->action = NULL;
1643 raw_spin_unlock_irqrestore(&desc->lock, flags);
1645 unregister_handler_proc(irq, action);
1647 module_put(desc->owner);
1651 raw_spin_unlock_irqrestore(&desc->lock, flags);
1656 * remove_percpu_irq - free a per-cpu interrupt
1657 * @irq: Interrupt line to free
1658 * @act: irqaction for the interrupt
1660 * Used to remove interrupts statically setup by the early boot process.
1662 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1664 struct irq_desc *desc = irq_to_desc(irq);
1666 if (desc && irq_settings_is_per_cpu_devid(desc))
1667 __free_percpu_irq(irq, act->percpu_dev_id);
1671 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1672 * @irq: Interrupt line to free
1673 * @dev_id: Device identity to free
1675 * Remove a percpu interrupt handler. The handler is removed, but
1676 * the interrupt line is not disabled. This must be done on each
1677 * CPU before calling this function. The function does not return
1678 * until any executing interrupts for this IRQ have completed.
1680 * This function must not be called from interrupt context.
1682 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1684 struct irq_desc *desc = irq_to_desc(irq);
1686 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1689 chip_bus_lock(desc);
1690 kfree(__free_percpu_irq(irq, dev_id));
1691 chip_bus_sync_unlock(desc);
1695 * setup_percpu_irq - setup a per-cpu interrupt
1696 * @irq: Interrupt line to setup
1697 * @act: irqaction for the interrupt
1699 * Used to statically setup per-cpu interrupts in the early boot process.
1701 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1703 struct irq_desc *desc = irq_to_desc(irq);
1706 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1708 chip_bus_lock(desc);
1709 retval = __setup_irq(irq, desc, act);
1710 chip_bus_sync_unlock(desc);
1716 * request_percpu_irq - allocate a percpu interrupt line
1717 * @irq: Interrupt line to allocate
1718 * @handler: Function to be called when the IRQ occurs.
1719 * @devname: An ascii name for the claiming device
1720 * @dev_id: A percpu cookie passed back to the handler function
1722 * This call allocates interrupt resources, but doesn't
1723 * automatically enable the interrupt. It has to be done on each
1724 * CPU using enable_percpu_irq().
1726 * Dev_id must be globally unique. It is a per-cpu variable, and
1727 * the handler gets called with the interrupted CPU's instance of
1730 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1731 const char *devname, void __percpu *dev_id)
1733 struct irqaction *action;
1734 struct irq_desc *desc;
1740 desc = irq_to_desc(irq);
1741 if (!desc || !irq_settings_can_request(desc) ||
1742 !irq_settings_is_per_cpu_devid(desc))
1745 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1749 action->handler = handler;
1750 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1751 action->name = devname;
1752 action->percpu_dev_id = dev_id;
1754 chip_bus_lock(desc);
1755 retval = __setup_irq(irq, desc, action);
1756 chip_bus_sync_unlock(desc);