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);
248 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
250 static void irq_affinity_notify(struct work_struct *work)
252 struct irq_affinity_notify *notify =
253 container_of(work, struct irq_affinity_notify, work);
254 struct irq_desc *desc = irq_to_desc(notify->irq);
255 cpumask_var_t cpumask;
258 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
261 raw_spin_lock_irqsave(&desc->lock, flags);
262 if (irq_move_pending(&desc->irq_data))
263 irq_get_pending(cpumask, desc);
265 cpumask_copy(cpumask, desc->irq_data.affinity);
266 raw_spin_unlock_irqrestore(&desc->lock, flags);
268 notify->notify(notify, cpumask);
270 free_cpumask_var(cpumask);
272 kref_put(¬ify->kref, notify->release);
276 * irq_set_affinity_notifier - control notification of IRQ affinity changes
277 * @irq: Interrupt for which to enable/disable notification
278 * @notify: Context for notification, or %NULL to disable
279 * notification. Function pointers must be initialised;
280 * the other fields will be initialised by this function.
282 * Must be called in process context. Notification may only be enabled
283 * after the IRQ is allocated and must be disabled before the IRQ is
284 * freed using free_irq().
287 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
289 struct irq_desc *desc = irq_to_desc(irq);
290 struct irq_affinity_notify *old_notify;
293 /* The release function is promised process context */
299 /* Complete initialisation of *notify */
302 kref_init(¬ify->kref);
303 INIT_WORK(¬ify->work, irq_affinity_notify);
306 raw_spin_lock_irqsave(&desc->lock, flags);
307 old_notify = desc->affinity_notify;
308 desc->affinity_notify = notify;
309 raw_spin_unlock_irqrestore(&desc->lock, flags);
312 kref_put(&old_notify->kref, old_notify->release);
316 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
318 #ifndef CONFIG_AUTO_IRQ_AFFINITY
320 * Generic version of the affinity autoselector.
323 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
325 struct cpumask *set = irq_default_affinity;
326 int node = desc->irq_data.node;
328 /* Excludes PER_CPU and NO_BALANCE interrupts */
329 if (!irq_can_set_affinity(irq))
333 * Preserve an userspace affinity setup, but make sure that
334 * one of the targets is online.
336 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
337 if (cpumask_intersects(desc->irq_data.affinity,
339 set = desc->irq_data.affinity;
341 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
344 cpumask_and(mask, cpu_online_mask, set);
345 if (node != NUMA_NO_NODE) {
346 const struct cpumask *nodemask = cpumask_of_node(node);
348 /* make sure at least one of the cpus in nodemask is online */
349 if (cpumask_intersects(mask, nodemask))
350 cpumask_and(mask, mask, nodemask);
352 irq_do_set_affinity(&desc->irq_data, mask, false);
357 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
359 return irq_select_affinity(irq);
364 * Called when affinity is set via /proc/irq
366 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
368 struct irq_desc *desc = irq_to_desc(irq);
372 raw_spin_lock_irqsave(&desc->lock, flags);
373 ret = setup_affinity(irq, desc, mask);
374 raw_spin_unlock_irqrestore(&desc->lock, flags);
380 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
386 void __disable_irq(struct irq_desc *desc, unsigned int irq)
392 static int __disable_irq_nosync(unsigned int irq)
395 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
399 __disable_irq(desc, irq);
400 irq_put_desc_busunlock(desc, flags);
405 * disable_irq_nosync - disable an irq without waiting
406 * @irq: Interrupt to disable
408 * Disable the selected interrupt line. Disables and Enables are
410 * Unlike disable_irq(), this function does not ensure existing
411 * instances of the IRQ handler have completed before returning.
413 * This function may be called from IRQ context.
415 void disable_irq_nosync(unsigned int irq)
417 __disable_irq_nosync(irq);
419 EXPORT_SYMBOL(disable_irq_nosync);
422 * disable_irq - disable an irq and wait for completion
423 * @irq: Interrupt to disable
425 * Disable the selected interrupt line. Enables and Disables are
427 * This function waits for any pending IRQ handlers for this interrupt
428 * to complete before returning. If you use this function while
429 * holding a resource the IRQ handler may need you will deadlock.
431 * This function may be called - with care - from IRQ context.
433 void disable_irq(unsigned int irq)
435 if (!__disable_irq_nosync(irq))
436 synchronize_irq(irq);
438 EXPORT_SYMBOL(disable_irq);
440 void __enable_irq(struct irq_desc *desc, unsigned int irq)
442 switch (desc->depth) {
445 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
448 if (desc->istate & IRQS_SUSPENDED)
450 /* Prevent probing on this irq: */
451 irq_settings_set_noprobe(desc);
453 check_irq_resend(desc, irq);
462 * enable_irq - enable handling of an irq
463 * @irq: Interrupt to enable
465 * Undoes the effect of one call to disable_irq(). If this
466 * matches the last disable, processing of interrupts on this
467 * IRQ line is re-enabled.
469 * This function may be called from IRQ context only when
470 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
472 void enable_irq(unsigned int irq)
475 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
479 if (WARN(!desc->irq_data.chip,
480 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
483 __enable_irq(desc, irq);
485 irq_put_desc_busunlock(desc, flags);
487 EXPORT_SYMBOL(enable_irq);
489 static int set_irq_wake_real(unsigned int irq, unsigned int on)
491 struct irq_desc *desc = irq_to_desc(irq);
494 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
497 if (desc->irq_data.chip->irq_set_wake)
498 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
504 * irq_set_irq_wake - control irq power management wakeup
505 * @irq: interrupt to control
506 * @on: enable/disable power management wakeup
508 * Enable/disable power management wakeup mode, which is
509 * disabled by default. Enables and disables must match,
510 * just as they match for non-wakeup mode support.
512 * Wakeup mode lets this IRQ wake the system from sleep
513 * states like "suspend to RAM".
515 int irq_set_irq_wake(unsigned int irq, unsigned int on)
518 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
524 /* wakeup-capable irqs can be shared between drivers that
525 * don't need to have the same sleep mode behaviors.
528 if (desc->wake_depth++ == 0) {
529 ret = set_irq_wake_real(irq, on);
531 desc->wake_depth = 0;
533 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
536 if (desc->wake_depth == 0) {
537 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
538 } else if (--desc->wake_depth == 0) {
539 ret = set_irq_wake_real(irq, on);
541 desc->wake_depth = 1;
543 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
546 irq_put_desc_busunlock(desc, flags);
549 EXPORT_SYMBOL(irq_set_irq_wake);
552 * Internal function that tells the architecture code whether a
553 * particular irq has been exclusively allocated or is available
556 int can_request_irq(unsigned int irq, unsigned long irqflags)
559 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
565 if (irq_settings_can_request(desc)) {
567 irqflags & desc->action->flags & IRQF_SHARED)
570 irq_put_desc_unlock(desc, flags);
574 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
577 struct irq_chip *chip = desc->irq_data.chip;
580 if (!chip || !chip->irq_set_type) {
582 * IRQF_TRIGGER_* but the PIC does not support multiple
585 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
586 chip ? (chip->name ? : "unknown") : "unknown");
590 flags &= IRQ_TYPE_SENSE_MASK;
592 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
593 if (!irqd_irq_masked(&desc->irq_data))
595 if (!irqd_irq_disabled(&desc->irq_data))
599 /* caller masked out all except trigger mode flags */
600 ret = chip->irq_set_type(&desc->irq_data, flags);
603 case IRQ_SET_MASK_OK:
604 case IRQ_SET_MASK_OK_DONE:
605 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
606 irqd_set(&desc->irq_data, flags);
608 case IRQ_SET_MASK_OK_NOCOPY:
609 flags = irqd_get_trigger_type(&desc->irq_data);
610 irq_settings_set_trigger_mask(desc, flags);
611 irqd_clear(&desc->irq_data, IRQD_LEVEL);
612 irq_settings_clr_level(desc);
613 if (flags & IRQ_TYPE_LEVEL_MASK) {
614 irq_settings_set_level(desc);
615 irqd_set(&desc->irq_data, IRQD_LEVEL);
621 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
622 flags, irq, chip->irq_set_type);
629 #ifdef CONFIG_HARDIRQS_SW_RESEND
630 int irq_set_parent(int irq, int parent_irq)
633 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
638 desc->parent_irq = parent_irq;
640 irq_put_desc_unlock(desc, flags);
646 * Default primary interrupt handler for threaded interrupts. Is
647 * assigned as primary handler when request_threaded_irq is called
648 * with handler == NULL. Useful for oneshot interrupts.
650 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
652 return IRQ_WAKE_THREAD;
656 * Primary handler for nested threaded interrupts. Should never be
659 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
661 WARN(1, "Primary handler called for nested irq %d\n", irq);
665 static int irq_wait_for_interrupt(struct irqaction *action)
667 set_current_state(TASK_INTERRUPTIBLE);
669 while (!kthread_should_stop()) {
671 if (test_and_clear_bit(IRQTF_RUNTHREAD,
672 &action->thread_flags)) {
673 __set_current_state(TASK_RUNNING);
677 set_current_state(TASK_INTERRUPTIBLE);
679 __set_current_state(TASK_RUNNING);
684 * Oneshot interrupts keep the irq line masked until the threaded
685 * handler finished. unmask if the interrupt has not been disabled and
688 static void irq_finalize_oneshot(struct irq_desc *desc,
689 struct irqaction *action)
691 if (!(desc->istate & IRQS_ONESHOT))
695 raw_spin_lock_irq(&desc->lock);
698 * Implausible though it may be we need to protect us against
699 * the following scenario:
701 * The thread is faster done than the hard interrupt handler
702 * on the other CPU. If we unmask the irq line then the
703 * interrupt can come in again and masks the line, leaves due
704 * to IRQS_INPROGRESS and the irq line is masked forever.
706 * This also serializes the state of shared oneshot handlers
707 * versus "desc->threads_onehsot |= action->thread_mask;" in
708 * irq_wake_thread(). See the comment there which explains the
711 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
712 raw_spin_unlock_irq(&desc->lock);
713 chip_bus_sync_unlock(desc);
719 * Now check again, whether the thread should run. Otherwise
720 * we would clear the threads_oneshot bit of this thread which
723 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
726 desc->threads_oneshot &= ~action->thread_mask;
728 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
729 irqd_irq_masked(&desc->irq_data))
730 unmask_threaded_irq(desc);
733 raw_spin_unlock_irq(&desc->lock);
734 chip_bus_sync_unlock(desc);
739 * Check whether we need to change the affinity of the interrupt thread.
742 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
747 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
751 * In case we are out of memory we set IRQTF_AFFINITY again and
752 * try again next time
754 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
755 set_bit(IRQTF_AFFINITY, &action->thread_flags);
759 raw_spin_lock_irq(&desc->lock);
761 * This code is triggered unconditionally. Check the affinity
762 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
764 if (desc->irq_data.affinity)
765 cpumask_copy(mask, desc->irq_data.affinity);
768 raw_spin_unlock_irq(&desc->lock);
771 set_cpus_allowed_ptr(current, mask);
772 free_cpumask_var(mask);
776 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
780 * Interrupts which are not explicitely requested as threaded
781 * interrupts rely on the implicit bh/preempt disable of the hard irq
782 * context. So we need to disable bh here to avoid deadlocks and other
786 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
791 ret = action->thread_fn(action->irq, action->dev_id);
792 irq_finalize_oneshot(desc, action);
798 * Interrupts explicitly requested as threaded interrupts want to be
799 * preemtible - many of them need to sleep and wait for slow busses to
802 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
803 struct irqaction *action)
807 ret = action->thread_fn(action->irq, action->dev_id);
808 irq_finalize_oneshot(desc, action);
812 static void wake_threads_waitq(struct irq_desc *desc)
814 if (atomic_dec_and_test(&desc->threads_active))
815 wake_up(&desc->wait_for_threads);
818 static void irq_thread_dtor(struct callback_head *unused)
820 struct task_struct *tsk = current;
821 struct irq_desc *desc;
822 struct irqaction *action;
824 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
827 action = kthread_data(tsk);
829 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
830 tsk->comm, tsk->pid, action->irq);
833 desc = irq_to_desc(action->irq);
835 * If IRQTF_RUNTHREAD is set, we need to decrement
836 * desc->threads_active and wake possible waiters.
838 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
839 wake_threads_waitq(desc);
841 /* Prevent a stale desc->threads_oneshot */
842 irq_finalize_oneshot(desc, action);
846 * Interrupt handler thread
848 static int irq_thread(void *data)
850 struct callback_head on_exit_work;
851 struct irqaction *action = data;
852 struct irq_desc *desc = irq_to_desc(action->irq);
853 irqreturn_t (*handler_fn)(struct irq_desc *desc,
854 struct irqaction *action);
856 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
857 &action->thread_flags))
858 handler_fn = irq_forced_thread_fn;
860 handler_fn = irq_thread_fn;
862 init_task_work(&on_exit_work, irq_thread_dtor);
863 task_work_add(current, &on_exit_work, false);
865 irq_thread_check_affinity(desc, action);
867 while (!irq_wait_for_interrupt(action)) {
868 irqreturn_t action_ret;
870 irq_thread_check_affinity(desc, action);
872 action_ret = handler_fn(desc, action);
873 if (action_ret == IRQ_HANDLED)
874 atomic_inc(&desc->threads_handled);
876 wake_threads_waitq(desc);
880 * This is the regular exit path. __free_irq() is stopping the
881 * thread via kthread_stop() after calling
882 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
883 * oneshot mask bit can be set. We cannot verify that as we
884 * cannot touch the oneshot mask at this point anymore as
885 * __setup_irq() might have given out currents thread_mask
888 task_work_cancel(current, irq_thread_dtor);
893 * irq_wake_thread - wake the irq thread for the action identified by dev_id
894 * @irq: Interrupt line
895 * @dev_id: Device identity for which the thread should be woken
898 void irq_wake_thread(unsigned int irq, void *dev_id)
900 struct irq_desc *desc = irq_to_desc(irq);
901 struct irqaction *action;
904 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
907 raw_spin_lock_irqsave(&desc->lock, flags);
908 for (action = desc->action; action; action = action->next) {
909 if (action->dev_id == dev_id) {
911 __irq_wake_thread(desc, action);
915 raw_spin_unlock_irqrestore(&desc->lock, flags);
917 EXPORT_SYMBOL_GPL(irq_wake_thread);
919 static void irq_setup_forced_threading(struct irqaction *new)
921 if (!force_irqthreads)
923 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
926 new->flags |= IRQF_ONESHOT;
928 if (!new->thread_fn) {
929 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
930 new->thread_fn = new->handler;
931 new->handler = irq_default_primary_handler;
935 static int irq_request_resources(struct irq_desc *desc)
937 struct irq_data *d = &desc->irq_data;
938 struct irq_chip *c = d->chip;
940 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
943 static void irq_release_resources(struct irq_desc *desc)
945 struct irq_data *d = &desc->irq_data;
946 struct irq_chip *c = d->chip;
948 if (c->irq_release_resources)
949 c->irq_release_resources(d);
953 * Internal function to register an irqaction - typically used to
954 * allocate special interrupts that are part of the architecture.
957 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
959 struct irqaction *old, **old_ptr;
960 unsigned long flags, thread_mask = 0;
961 int ret, nested, shared = 0;
967 if (desc->irq_data.chip == &no_irq_chip)
969 if (!try_module_get(desc->owner))
973 * Check whether the interrupt nests into another interrupt
976 nested = irq_settings_is_nested_thread(desc);
978 if (!new->thread_fn) {
983 * Replace the primary handler which was provided from
984 * the driver for non nested interrupt handling by the
985 * dummy function which warns when called.
987 new->handler = irq_nested_primary_handler;
989 if (irq_settings_can_thread(desc))
990 irq_setup_forced_threading(new);
994 * Create a handler thread when a thread function is supplied
995 * and the interrupt does not nest into another interrupt
998 if (new->thread_fn && !nested) {
999 struct task_struct *t;
1000 static const struct sched_param param = {
1001 .sched_priority = MAX_USER_RT_PRIO/2,
1004 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1011 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1014 * We keep the reference to the task struct even if
1015 * the thread dies to avoid that the interrupt code
1016 * references an already freed task_struct.
1021 * Tell the thread to set its affinity. This is
1022 * important for shared interrupt handlers as we do
1023 * not invoke setup_affinity() for the secondary
1024 * handlers as everything is already set up. Even for
1025 * interrupts marked with IRQF_NO_BALANCE this is
1026 * correct as we want the thread to move to the cpu(s)
1027 * on which the requesting code placed the interrupt.
1029 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1032 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1038 * Drivers are often written to work w/o knowledge about the
1039 * underlying irq chip implementation, so a request for a
1040 * threaded irq without a primary hard irq context handler
1041 * requires the ONESHOT flag to be set. Some irq chips like
1042 * MSI based interrupts are per se one shot safe. Check the
1043 * chip flags, so we can avoid the unmask dance at the end of
1044 * the threaded handler for those.
1046 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1047 new->flags &= ~IRQF_ONESHOT;
1050 * The following block of code has to be executed atomically
1052 raw_spin_lock_irqsave(&desc->lock, flags);
1053 old_ptr = &desc->action;
1057 * Can't share interrupts unless both agree to and are
1058 * the same type (level, edge, polarity). So both flag
1059 * fields must have IRQF_SHARED set and the bits which
1060 * set the trigger type must match. Also all must
1063 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1064 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1065 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1068 /* All handlers must agree on per-cpuness */
1069 if ((old->flags & IRQF_PERCPU) !=
1070 (new->flags & IRQF_PERCPU))
1073 /* add new interrupt at end of irq queue */
1076 * Or all existing action->thread_mask bits,
1077 * so we can find the next zero bit for this
1080 thread_mask |= old->thread_mask;
1081 old_ptr = &old->next;
1088 * Setup the thread mask for this irqaction for ONESHOT. For
1089 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1090 * conditional in irq_wake_thread().
1092 if (new->flags & IRQF_ONESHOT) {
1094 * Unlikely to have 32 resp 64 irqs sharing one line,
1097 if (thread_mask == ~0UL) {
1102 * The thread_mask for the action is or'ed to
1103 * desc->thread_active to indicate that the
1104 * IRQF_ONESHOT thread handler has been woken, but not
1105 * yet finished. The bit is cleared when a thread
1106 * completes. When all threads of a shared interrupt
1107 * line have completed desc->threads_active becomes
1108 * zero and the interrupt line is unmasked. See
1109 * handle.c:irq_wake_thread() for further information.
1111 * If no thread is woken by primary (hard irq context)
1112 * interrupt handlers, then desc->threads_active is
1113 * also checked for zero to unmask the irq line in the
1114 * affected hard irq flow handlers
1115 * (handle_[fasteoi|level]_irq).
1117 * The new action gets the first zero bit of
1118 * thread_mask assigned. See the loop above which or's
1119 * all existing action->thread_mask bits.
1121 new->thread_mask = 1 << ffz(thread_mask);
1123 } else if (new->handler == irq_default_primary_handler &&
1124 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1126 * The interrupt was requested with handler = NULL, so
1127 * we use the default primary handler for it. But it
1128 * does not have the oneshot flag set. In combination
1129 * with level interrupts this is deadly, because the
1130 * default primary handler just wakes the thread, then
1131 * the irq lines is reenabled, but the device still
1132 * has the level irq asserted. Rinse and repeat....
1134 * While this works for edge type interrupts, we play
1135 * it safe and reject unconditionally because we can't
1136 * say for sure which type this interrupt really
1137 * has. The type flags are unreliable as the
1138 * underlying chip implementation can override them.
1140 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1147 ret = irq_request_resources(desc);
1149 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1150 new->name, irq, desc->irq_data.chip->name);
1154 init_waitqueue_head(&desc->wait_for_threads);
1156 /* Setup the type (level, edge polarity) if configured: */
1157 if (new->flags & IRQF_TRIGGER_MASK) {
1158 ret = __irq_set_trigger(desc, irq,
1159 new->flags & IRQF_TRIGGER_MASK);
1165 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1166 IRQS_ONESHOT | IRQS_WAITING);
1167 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1169 if (new->flags & IRQF_PERCPU) {
1170 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1171 irq_settings_set_per_cpu(desc);
1174 if (new->flags & IRQF_ONESHOT)
1175 desc->istate |= IRQS_ONESHOT;
1177 if (irq_settings_can_autoenable(desc))
1178 irq_startup(desc, true);
1180 /* Undo nested disables: */
1183 /* Exclude IRQ from balancing if requested */
1184 if (new->flags & IRQF_NOBALANCING) {
1185 irq_settings_set_no_balancing(desc);
1186 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1189 /* Set default affinity mask once everything is setup */
1190 setup_affinity(irq, desc, mask);
1192 } else if (new->flags & IRQF_TRIGGER_MASK) {
1193 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1194 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1197 /* hope the handler works with current trigger mode */
1198 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1205 irq_pm_install_action(desc, new);
1207 /* Reset broken irq detection when installing new handler */
1208 desc->irq_count = 0;
1209 desc->irqs_unhandled = 0;
1212 * Check whether we disabled the irq via the spurious handler
1213 * before. Reenable it and give it another chance.
1215 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1216 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1217 __enable_irq(desc, irq);
1220 raw_spin_unlock_irqrestore(&desc->lock, flags);
1223 * Strictly no need to wake it up, but hung_task complains
1224 * when no hard interrupt wakes the thread up.
1227 wake_up_process(new->thread);
1229 register_irq_proc(irq, desc);
1231 register_handler_proc(irq, new);
1232 free_cpumask_var(mask);
1237 if (!(new->flags & IRQF_PROBE_SHARED)) {
1238 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1239 irq, new->flags, new->name, old->flags, old->name);
1240 #ifdef CONFIG_DEBUG_SHIRQ
1247 raw_spin_unlock_irqrestore(&desc->lock, flags);
1248 free_cpumask_var(mask);
1252 struct task_struct *t = new->thread;
1259 module_put(desc->owner);
1264 * setup_irq - setup an interrupt
1265 * @irq: Interrupt line to setup
1266 * @act: irqaction for the interrupt
1268 * Used to statically setup interrupts in the early boot process.
1270 int setup_irq(unsigned int irq, struct irqaction *act)
1273 struct irq_desc *desc = irq_to_desc(irq);
1275 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1277 chip_bus_lock(desc);
1278 retval = __setup_irq(irq, desc, act);
1279 chip_bus_sync_unlock(desc);
1283 EXPORT_SYMBOL_GPL(setup_irq);
1286 * Internal function to unregister an irqaction - used to free
1287 * regular and special interrupts that are part of the architecture.
1289 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1291 struct irq_desc *desc = irq_to_desc(irq);
1292 struct irqaction *action, **action_ptr;
1293 unsigned long flags;
1295 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1300 raw_spin_lock_irqsave(&desc->lock, flags);
1303 * There can be multiple actions per IRQ descriptor, find the right
1304 * one based on the dev_id:
1306 action_ptr = &desc->action;
1308 action = *action_ptr;
1311 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1312 raw_spin_unlock_irqrestore(&desc->lock, flags);
1317 if (action->dev_id == dev_id)
1319 action_ptr = &action->next;
1322 /* Found it - now remove it from the list of entries: */
1323 *action_ptr = action->next;
1325 irq_pm_remove_action(desc, action);
1327 /* If this was the last handler, shut down the IRQ line: */
1328 if (!desc->action) {
1330 irq_release_resources(desc);
1334 /* make sure affinity_hint is cleaned up */
1335 if (WARN_ON_ONCE(desc->affinity_hint))
1336 desc->affinity_hint = NULL;
1339 raw_spin_unlock_irqrestore(&desc->lock, flags);
1341 unregister_handler_proc(irq, action);
1343 /* Make sure it's not being used on another CPU: */
1344 synchronize_irq(irq);
1346 #ifdef CONFIG_DEBUG_SHIRQ
1348 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1349 * event to happen even now it's being freed, so let's make sure that
1350 * is so by doing an extra call to the handler ....
1352 * ( We do this after actually deregistering it, to make sure that a
1353 * 'real' IRQ doesn't run in * parallel with our fake. )
1355 if (action->flags & IRQF_SHARED) {
1356 local_irq_save(flags);
1357 action->handler(irq, dev_id);
1358 local_irq_restore(flags);
1362 if (action->thread) {
1363 kthread_stop(action->thread);
1364 put_task_struct(action->thread);
1367 module_put(desc->owner);
1372 * remove_irq - free an interrupt
1373 * @irq: Interrupt line to free
1374 * @act: irqaction for the interrupt
1376 * Used to remove interrupts statically setup by the early boot process.
1378 void remove_irq(unsigned int irq, struct irqaction *act)
1380 struct irq_desc *desc = irq_to_desc(irq);
1382 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1383 __free_irq(irq, act->dev_id);
1385 EXPORT_SYMBOL_GPL(remove_irq);
1388 * free_irq - free an interrupt allocated with request_irq
1389 * @irq: Interrupt line to free
1390 * @dev_id: Device identity to free
1392 * Remove an interrupt handler. The handler is removed and if the
1393 * interrupt line is no longer in use by any driver it is disabled.
1394 * On a shared IRQ the caller must ensure the interrupt is disabled
1395 * on the card it drives before calling this function. The function
1396 * does not return until any executing interrupts for this IRQ
1399 * This function must not be called from interrupt context.
1401 void free_irq(unsigned int irq, void *dev_id)
1403 struct irq_desc *desc = irq_to_desc(irq);
1405 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1409 if (WARN_ON(desc->affinity_notify))
1410 desc->affinity_notify = NULL;
1413 chip_bus_lock(desc);
1414 kfree(__free_irq(irq, dev_id));
1415 chip_bus_sync_unlock(desc);
1417 EXPORT_SYMBOL(free_irq);
1420 * request_threaded_irq - allocate an interrupt line
1421 * @irq: Interrupt line to allocate
1422 * @handler: Function to be called when the IRQ occurs.
1423 * Primary handler for threaded interrupts
1424 * If NULL and thread_fn != NULL the default
1425 * primary handler is installed
1426 * @thread_fn: Function called from the irq handler thread
1427 * If NULL, no irq thread is created
1428 * @irqflags: Interrupt type flags
1429 * @devname: An ascii name for the claiming device
1430 * @dev_id: A cookie passed back to the handler function
1432 * This call allocates interrupt resources and enables the
1433 * interrupt line and IRQ handling. From the point this
1434 * call is made your handler function may be invoked. Since
1435 * your handler function must clear any interrupt the board
1436 * raises, you must take care both to initialise your hardware
1437 * and to set up the interrupt handler in the right order.
1439 * If you want to set up a threaded irq handler for your device
1440 * then you need to supply @handler and @thread_fn. @handler is
1441 * still called in hard interrupt context and has to check
1442 * whether the interrupt originates from the device. If yes it
1443 * needs to disable the interrupt on the device and return
1444 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1445 * @thread_fn. This split handler design is necessary to support
1446 * shared interrupts.
1448 * Dev_id must be globally unique. Normally the address of the
1449 * device data structure is used as the cookie. Since the handler
1450 * receives this value it makes sense to use it.
1452 * If your interrupt is shared you must pass a non NULL dev_id
1453 * as this is required when freeing the interrupt.
1457 * IRQF_SHARED Interrupt is shared
1458 * IRQF_TRIGGER_* Specify active edge(s) or level
1461 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1462 irq_handler_t thread_fn, unsigned long irqflags,
1463 const char *devname, void *dev_id)
1465 struct irqaction *action;
1466 struct irq_desc *desc;
1470 * Sanity-check: shared interrupts must pass in a real dev-ID,
1471 * otherwise we'll have trouble later trying to figure out
1472 * which interrupt is which (messes up the interrupt freeing
1475 if ((irqflags & IRQF_SHARED) && !dev_id)
1478 desc = irq_to_desc(irq);
1482 if (!irq_settings_can_request(desc) ||
1483 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1489 handler = irq_default_primary_handler;
1492 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1496 action->handler = handler;
1497 action->thread_fn = thread_fn;
1498 action->flags = irqflags;
1499 action->name = devname;
1500 action->dev_id = dev_id;
1502 chip_bus_lock(desc);
1503 retval = __setup_irq(irq, desc, action);
1504 chip_bus_sync_unlock(desc);
1509 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1510 if (!retval && (irqflags & IRQF_SHARED)) {
1512 * It's a shared IRQ -- the driver ought to be prepared for it
1513 * to happen immediately, so let's make sure....
1514 * We disable the irq to make sure that a 'real' IRQ doesn't
1515 * run in parallel with our fake.
1517 unsigned long flags;
1520 local_irq_save(flags);
1522 handler(irq, dev_id);
1524 local_irq_restore(flags);
1530 EXPORT_SYMBOL(request_threaded_irq);
1533 * request_any_context_irq - allocate an interrupt line
1534 * @irq: Interrupt line to allocate
1535 * @handler: Function to be called when the IRQ occurs.
1536 * Threaded handler for threaded interrupts.
1537 * @flags: Interrupt type flags
1538 * @name: An ascii name for the claiming device
1539 * @dev_id: A cookie passed back to the handler function
1541 * This call allocates interrupt resources and enables the
1542 * interrupt line and IRQ handling. It selects either a
1543 * hardirq or threaded handling method depending on the
1546 * On failure, it returns a negative value. On success,
1547 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1549 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1550 unsigned long flags, const char *name, void *dev_id)
1552 struct irq_desc *desc = irq_to_desc(irq);
1558 if (irq_settings_is_nested_thread(desc)) {
1559 ret = request_threaded_irq(irq, NULL, handler,
1560 flags, name, dev_id);
1561 return !ret ? IRQC_IS_NESTED : ret;
1564 ret = request_irq(irq, handler, flags, name, dev_id);
1565 return !ret ? IRQC_IS_HARDIRQ : ret;
1567 EXPORT_SYMBOL_GPL(request_any_context_irq);
1569 void enable_percpu_irq(unsigned int irq, unsigned int type)
1571 unsigned int cpu = smp_processor_id();
1572 unsigned long flags;
1573 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1578 type &= IRQ_TYPE_SENSE_MASK;
1579 if (type != IRQ_TYPE_NONE) {
1582 ret = __irq_set_trigger(desc, irq, type);
1585 WARN(1, "failed to set type for IRQ%d\n", irq);
1590 irq_percpu_enable(desc, cpu);
1592 irq_put_desc_unlock(desc, flags);
1594 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1596 void disable_percpu_irq(unsigned int irq)
1598 unsigned int cpu = smp_processor_id();
1599 unsigned long flags;
1600 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1605 irq_percpu_disable(desc, cpu);
1606 irq_put_desc_unlock(desc, flags);
1608 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1611 * Internal function to unregister a percpu irqaction.
1613 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1615 struct irq_desc *desc = irq_to_desc(irq);
1616 struct irqaction *action;
1617 unsigned long flags;
1619 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1624 raw_spin_lock_irqsave(&desc->lock, flags);
1626 action = desc->action;
1627 if (!action || action->percpu_dev_id != dev_id) {
1628 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1632 if (!cpumask_empty(desc->percpu_enabled)) {
1633 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1634 irq, cpumask_first(desc->percpu_enabled));
1638 /* Found it - now remove it from the list of entries: */
1639 desc->action = NULL;
1641 raw_spin_unlock_irqrestore(&desc->lock, flags);
1643 unregister_handler_proc(irq, action);
1645 module_put(desc->owner);
1649 raw_spin_unlock_irqrestore(&desc->lock, flags);
1654 * remove_percpu_irq - free a per-cpu interrupt
1655 * @irq: Interrupt line to free
1656 * @act: irqaction for the interrupt
1658 * Used to remove interrupts statically setup by the early boot process.
1660 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1662 struct irq_desc *desc = irq_to_desc(irq);
1664 if (desc && irq_settings_is_per_cpu_devid(desc))
1665 __free_percpu_irq(irq, act->percpu_dev_id);
1669 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1670 * @irq: Interrupt line to free
1671 * @dev_id: Device identity to free
1673 * Remove a percpu interrupt handler. The handler is removed, but
1674 * the interrupt line is not disabled. This must be done on each
1675 * CPU before calling this function. The function does not return
1676 * until any executing interrupts for this IRQ have completed.
1678 * This function must not be called from interrupt context.
1680 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1682 struct irq_desc *desc = irq_to_desc(irq);
1684 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1687 chip_bus_lock(desc);
1688 kfree(__free_percpu_irq(irq, dev_id));
1689 chip_bus_sync_unlock(desc);
1693 * setup_percpu_irq - setup a per-cpu interrupt
1694 * @irq: Interrupt line to setup
1695 * @act: irqaction for the interrupt
1697 * Used to statically setup per-cpu interrupts in the early boot process.
1699 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1701 struct irq_desc *desc = irq_to_desc(irq);
1704 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1706 chip_bus_lock(desc);
1707 retval = __setup_irq(irq, desc, act);
1708 chip_bus_sync_unlock(desc);
1714 * request_percpu_irq - allocate a percpu interrupt line
1715 * @irq: Interrupt line to allocate
1716 * @handler: Function to be called when the IRQ occurs.
1717 * @devname: An ascii name for the claiming device
1718 * @dev_id: A percpu cookie passed back to the handler function
1720 * This call allocates interrupt resources, but doesn't
1721 * automatically enable the interrupt. It has to be done on each
1722 * CPU using enable_percpu_irq().
1724 * Dev_id must be globally unique. It is a per-cpu variable, and
1725 * the handler gets called with the interrupted CPU's instance of
1728 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1729 const char *devname, void __percpu *dev_id)
1731 struct irqaction *action;
1732 struct irq_desc *desc;
1738 desc = irq_to_desc(irq);
1739 if (!desc || !irq_settings_can_request(desc) ||
1740 !irq_settings_is_per_cpu_devid(desc))
1743 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1747 action->handler = handler;
1748 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1749 action->name = devname;
1750 action->percpu_dev_id = dev_id;
1752 chip_bus_lock(desc);
1753 retval = __setup_irq(irq, desc, action);
1754 chip_bus_sync_unlock(desc);