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 */
248 __irq_set_affinity(irq, m, false);
251 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
253 static void irq_affinity_notify(struct work_struct *work)
255 struct irq_affinity_notify *notify =
256 container_of(work, struct irq_affinity_notify, work);
257 struct irq_desc *desc = irq_to_desc(notify->irq);
258 cpumask_var_t cpumask;
261 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
264 raw_spin_lock_irqsave(&desc->lock, flags);
265 if (irq_move_pending(&desc->irq_data))
266 irq_get_pending(cpumask, desc);
268 cpumask_copy(cpumask, desc->irq_data.affinity);
269 raw_spin_unlock_irqrestore(&desc->lock, flags);
271 notify->notify(notify, cpumask);
273 free_cpumask_var(cpumask);
275 kref_put(¬ify->kref, notify->release);
279 * irq_set_affinity_notifier - control notification of IRQ affinity changes
280 * @irq: Interrupt for which to enable/disable notification
281 * @notify: Context for notification, or %NULL to disable
282 * notification. Function pointers must be initialised;
283 * the other fields will be initialised by this function.
285 * Must be called in process context. Notification may only be enabled
286 * after the IRQ is allocated and must be disabled before the IRQ is
287 * freed using free_irq().
290 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
292 struct irq_desc *desc = irq_to_desc(irq);
293 struct irq_affinity_notify *old_notify;
296 /* The release function is promised process context */
302 /* Complete initialisation of *notify */
305 kref_init(¬ify->kref);
306 INIT_WORK(¬ify->work, irq_affinity_notify);
309 raw_spin_lock_irqsave(&desc->lock, flags);
310 old_notify = desc->affinity_notify;
311 desc->affinity_notify = notify;
312 raw_spin_unlock_irqrestore(&desc->lock, flags);
315 kref_put(&old_notify->kref, old_notify->release);
319 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
321 #ifndef CONFIG_AUTO_IRQ_AFFINITY
323 * Generic version of the affinity autoselector.
326 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
328 struct cpumask *set = irq_default_affinity;
329 int node = desc->irq_data.node;
331 /* Excludes PER_CPU and NO_BALANCE interrupts */
332 if (!irq_can_set_affinity(irq))
336 * Preserve an userspace affinity setup, but make sure that
337 * one of the targets is online.
339 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
340 if (cpumask_intersects(desc->irq_data.affinity,
342 set = desc->irq_data.affinity;
344 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
347 cpumask_and(mask, cpu_online_mask, set);
348 if (node != NUMA_NO_NODE) {
349 const struct cpumask *nodemask = cpumask_of_node(node);
351 /* make sure at least one of the cpus in nodemask is online */
352 if (cpumask_intersects(mask, nodemask))
353 cpumask_and(mask, mask, nodemask);
355 irq_do_set_affinity(&desc->irq_data, mask, false);
360 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
362 return irq_select_affinity(irq);
367 * Called when affinity is set via /proc/irq
369 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
371 struct irq_desc *desc = irq_to_desc(irq);
375 raw_spin_lock_irqsave(&desc->lock, flags);
376 ret = setup_affinity(irq, desc, mask);
377 raw_spin_unlock_irqrestore(&desc->lock, flags);
383 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
389 void __disable_irq(struct irq_desc *desc, unsigned int irq)
395 static int __disable_irq_nosync(unsigned int irq)
398 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
402 __disable_irq(desc, irq);
403 irq_put_desc_busunlock(desc, flags);
408 * disable_irq_nosync - disable an irq without waiting
409 * @irq: Interrupt to disable
411 * Disable the selected interrupt line. Disables and Enables are
413 * Unlike disable_irq(), this function does not ensure existing
414 * instances of the IRQ handler have completed before returning.
416 * This function may be called from IRQ context.
418 void disable_irq_nosync(unsigned int irq)
420 __disable_irq_nosync(irq);
422 EXPORT_SYMBOL(disable_irq_nosync);
425 * disable_irq - disable an irq and wait for completion
426 * @irq: Interrupt to disable
428 * Disable the selected interrupt line. Enables and Disables are
430 * This function waits for any pending IRQ handlers for this interrupt
431 * to complete before returning. If you use this function while
432 * holding a resource the IRQ handler may need you will deadlock.
434 * This function may be called - with care - from IRQ context.
436 void disable_irq(unsigned int irq)
438 if (!__disable_irq_nosync(irq))
439 synchronize_irq(irq);
441 EXPORT_SYMBOL(disable_irq);
443 void __enable_irq(struct irq_desc *desc, unsigned int irq)
445 switch (desc->depth) {
448 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
451 if (desc->istate & IRQS_SUSPENDED)
453 /* Prevent probing on this irq: */
454 irq_settings_set_noprobe(desc);
456 check_irq_resend(desc, irq);
465 * enable_irq - enable handling of an irq
466 * @irq: Interrupt to enable
468 * Undoes the effect of one call to disable_irq(). If this
469 * matches the last disable, processing of interrupts on this
470 * IRQ line is re-enabled.
472 * This function may be called from IRQ context only when
473 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
475 void enable_irq(unsigned int irq)
478 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
482 if (WARN(!desc->irq_data.chip,
483 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
486 __enable_irq(desc, irq);
488 irq_put_desc_busunlock(desc, flags);
490 EXPORT_SYMBOL(enable_irq);
492 static int set_irq_wake_real(unsigned int irq, unsigned int on)
494 struct irq_desc *desc = irq_to_desc(irq);
497 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
500 if (desc->irq_data.chip->irq_set_wake)
501 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
507 * irq_set_irq_wake - control irq power management wakeup
508 * @irq: interrupt to control
509 * @on: enable/disable power management wakeup
511 * Enable/disable power management wakeup mode, which is
512 * disabled by default. Enables and disables must match,
513 * just as they match for non-wakeup mode support.
515 * Wakeup mode lets this IRQ wake the system from sleep
516 * states like "suspend to RAM".
518 int irq_set_irq_wake(unsigned int irq, unsigned int on)
521 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
527 /* wakeup-capable irqs can be shared between drivers that
528 * don't need to have the same sleep mode behaviors.
531 if (desc->wake_depth++ == 0) {
532 ret = set_irq_wake_real(irq, on);
534 desc->wake_depth = 0;
536 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
539 if (desc->wake_depth == 0) {
540 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
541 } else if (--desc->wake_depth == 0) {
542 ret = set_irq_wake_real(irq, on);
544 desc->wake_depth = 1;
546 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
549 irq_put_desc_busunlock(desc, flags);
552 EXPORT_SYMBOL(irq_set_irq_wake);
555 * Internal function that tells the architecture code whether a
556 * particular irq has been exclusively allocated or is available
559 int can_request_irq(unsigned int irq, unsigned long irqflags)
562 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
568 if (irq_settings_can_request(desc)) {
570 irqflags & desc->action->flags & IRQF_SHARED)
573 irq_put_desc_unlock(desc, flags);
577 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
580 struct irq_chip *chip = desc->irq_data.chip;
583 if (!chip || !chip->irq_set_type) {
585 * IRQF_TRIGGER_* but the PIC does not support multiple
588 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
589 chip ? (chip->name ? : "unknown") : "unknown");
593 flags &= IRQ_TYPE_SENSE_MASK;
595 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
596 if (!irqd_irq_masked(&desc->irq_data))
598 if (!irqd_irq_disabled(&desc->irq_data))
602 /* caller masked out all except trigger mode flags */
603 ret = chip->irq_set_type(&desc->irq_data, flags);
606 case IRQ_SET_MASK_OK:
607 case IRQ_SET_MASK_OK_DONE:
608 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
609 irqd_set(&desc->irq_data, flags);
611 case IRQ_SET_MASK_OK_NOCOPY:
612 flags = irqd_get_trigger_type(&desc->irq_data);
613 irq_settings_set_trigger_mask(desc, flags);
614 irqd_clear(&desc->irq_data, IRQD_LEVEL);
615 irq_settings_clr_level(desc);
616 if (flags & IRQ_TYPE_LEVEL_MASK) {
617 irq_settings_set_level(desc);
618 irqd_set(&desc->irq_data, IRQD_LEVEL);
624 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
625 flags, irq, chip->irq_set_type);
632 #ifdef CONFIG_HARDIRQS_SW_RESEND
633 int irq_set_parent(int irq, int parent_irq)
636 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
641 desc->parent_irq = parent_irq;
643 irq_put_desc_unlock(desc, flags);
649 * Default primary interrupt handler for threaded interrupts. Is
650 * assigned as primary handler when request_threaded_irq is called
651 * with handler == NULL. Useful for oneshot interrupts.
653 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
655 return IRQ_WAKE_THREAD;
659 * Primary handler for nested threaded interrupts. Should never be
662 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
664 WARN(1, "Primary handler called for nested irq %d\n", irq);
668 static int irq_wait_for_interrupt(struct irqaction *action)
670 set_current_state(TASK_INTERRUPTIBLE);
672 while (!kthread_should_stop()) {
674 if (test_and_clear_bit(IRQTF_RUNTHREAD,
675 &action->thread_flags)) {
676 __set_current_state(TASK_RUNNING);
680 set_current_state(TASK_INTERRUPTIBLE);
682 __set_current_state(TASK_RUNNING);
687 * Oneshot interrupts keep the irq line masked until the threaded
688 * handler finished. unmask if the interrupt has not been disabled and
691 static void irq_finalize_oneshot(struct irq_desc *desc,
692 struct irqaction *action)
694 if (!(desc->istate & IRQS_ONESHOT))
698 raw_spin_lock_irq(&desc->lock);
701 * Implausible though it may be we need to protect us against
702 * the following scenario:
704 * The thread is faster done than the hard interrupt handler
705 * on the other CPU. If we unmask the irq line then the
706 * interrupt can come in again and masks the line, leaves due
707 * to IRQS_INPROGRESS and the irq line is masked forever.
709 * This also serializes the state of shared oneshot handlers
710 * versus "desc->threads_onehsot |= action->thread_mask;" in
711 * irq_wake_thread(). See the comment there which explains the
714 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
715 raw_spin_unlock_irq(&desc->lock);
716 chip_bus_sync_unlock(desc);
722 * Now check again, whether the thread should run. Otherwise
723 * we would clear the threads_oneshot bit of this thread which
726 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
729 desc->threads_oneshot &= ~action->thread_mask;
731 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
732 irqd_irq_masked(&desc->irq_data))
733 unmask_threaded_irq(desc);
736 raw_spin_unlock_irq(&desc->lock);
737 chip_bus_sync_unlock(desc);
742 * Check whether we need to change the affinity of the interrupt thread.
745 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
750 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
754 * In case we are out of memory we set IRQTF_AFFINITY again and
755 * try again next time
757 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
758 set_bit(IRQTF_AFFINITY, &action->thread_flags);
762 raw_spin_lock_irq(&desc->lock);
764 * This code is triggered unconditionally. Check the affinity
765 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
767 if (desc->irq_data.affinity)
768 cpumask_copy(mask, desc->irq_data.affinity);
771 raw_spin_unlock_irq(&desc->lock);
774 set_cpus_allowed_ptr(current, mask);
775 free_cpumask_var(mask);
779 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
783 * Interrupts which are not explicitely requested as threaded
784 * interrupts rely on the implicit bh/preempt disable of the hard irq
785 * context. So we need to disable bh here to avoid deadlocks and other
789 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
794 ret = action->thread_fn(action->irq, action->dev_id);
795 irq_finalize_oneshot(desc, action);
801 * Interrupts explicitly requested as threaded interrupts want to be
802 * preemtible - many of them need to sleep and wait for slow busses to
805 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
806 struct irqaction *action)
810 ret = action->thread_fn(action->irq, action->dev_id);
811 irq_finalize_oneshot(desc, action);
815 static void wake_threads_waitq(struct irq_desc *desc)
817 if (atomic_dec_and_test(&desc->threads_active))
818 wake_up(&desc->wait_for_threads);
821 static void irq_thread_dtor(struct callback_head *unused)
823 struct task_struct *tsk = current;
824 struct irq_desc *desc;
825 struct irqaction *action;
827 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
830 action = kthread_data(tsk);
832 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
833 tsk->comm, tsk->pid, action->irq);
836 desc = irq_to_desc(action->irq);
838 * If IRQTF_RUNTHREAD is set, we need to decrement
839 * desc->threads_active and wake possible waiters.
841 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
842 wake_threads_waitq(desc);
844 /* Prevent a stale desc->threads_oneshot */
845 irq_finalize_oneshot(desc, action);
849 * Interrupt handler thread
851 static int irq_thread(void *data)
853 struct callback_head on_exit_work;
854 struct irqaction *action = data;
855 struct irq_desc *desc = irq_to_desc(action->irq);
856 irqreturn_t (*handler_fn)(struct irq_desc *desc,
857 struct irqaction *action);
859 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
860 &action->thread_flags))
861 handler_fn = irq_forced_thread_fn;
863 handler_fn = irq_thread_fn;
865 init_task_work(&on_exit_work, irq_thread_dtor);
866 task_work_add(current, &on_exit_work, false);
868 irq_thread_check_affinity(desc, action);
870 while (!irq_wait_for_interrupt(action)) {
871 irqreturn_t action_ret;
873 irq_thread_check_affinity(desc, action);
875 action_ret = handler_fn(desc, action);
876 if (action_ret == IRQ_HANDLED)
877 atomic_inc(&desc->threads_handled);
879 wake_threads_waitq(desc);
883 * This is the regular exit path. __free_irq() is stopping the
884 * thread via kthread_stop() after calling
885 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
886 * oneshot mask bit can be set. We cannot verify that as we
887 * cannot touch the oneshot mask at this point anymore as
888 * __setup_irq() might have given out currents thread_mask
891 task_work_cancel(current, irq_thread_dtor);
896 * irq_wake_thread - wake the irq thread for the action identified by dev_id
897 * @irq: Interrupt line
898 * @dev_id: Device identity for which the thread should be woken
901 void irq_wake_thread(unsigned int irq, void *dev_id)
903 struct irq_desc *desc = irq_to_desc(irq);
904 struct irqaction *action;
907 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
910 raw_spin_lock_irqsave(&desc->lock, flags);
911 for (action = desc->action; action; action = action->next) {
912 if (action->dev_id == dev_id) {
914 __irq_wake_thread(desc, action);
918 raw_spin_unlock_irqrestore(&desc->lock, flags);
920 EXPORT_SYMBOL_GPL(irq_wake_thread);
922 static void irq_setup_forced_threading(struct irqaction *new)
924 if (!force_irqthreads)
926 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
929 new->flags |= IRQF_ONESHOT;
931 if (!new->thread_fn) {
932 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
933 new->thread_fn = new->handler;
934 new->handler = irq_default_primary_handler;
938 static int irq_request_resources(struct irq_desc *desc)
940 struct irq_data *d = &desc->irq_data;
941 struct irq_chip *c = d->chip;
943 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
946 static void irq_release_resources(struct irq_desc *desc)
948 struct irq_data *d = &desc->irq_data;
949 struct irq_chip *c = d->chip;
951 if (c->irq_release_resources)
952 c->irq_release_resources(d);
956 * Internal function to register an irqaction - typically used to
957 * allocate special interrupts that are part of the architecture.
960 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
962 struct irqaction *old, **old_ptr;
963 unsigned long flags, thread_mask = 0;
964 int ret, nested, shared = 0;
970 if (desc->irq_data.chip == &no_irq_chip)
972 if (!try_module_get(desc->owner))
976 * Check whether the interrupt nests into another interrupt
979 nested = irq_settings_is_nested_thread(desc);
981 if (!new->thread_fn) {
986 * Replace the primary handler which was provided from
987 * the driver for non nested interrupt handling by the
988 * dummy function which warns when called.
990 new->handler = irq_nested_primary_handler;
992 if (irq_settings_can_thread(desc))
993 irq_setup_forced_threading(new);
997 * Create a handler thread when a thread function is supplied
998 * and the interrupt does not nest into another interrupt
1001 if (new->thread_fn && !nested) {
1002 struct task_struct *t;
1003 static const struct sched_param param = {
1004 .sched_priority = MAX_USER_RT_PRIO/2,
1007 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1014 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1017 * We keep the reference to the task struct even if
1018 * the thread dies to avoid that the interrupt code
1019 * references an already freed task_struct.
1024 * Tell the thread to set its affinity. This is
1025 * important for shared interrupt handlers as we do
1026 * not invoke setup_affinity() for the secondary
1027 * handlers as everything is already set up. Even for
1028 * interrupts marked with IRQF_NO_BALANCE this is
1029 * correct as we want the thread to move to the cpu(s)
1030 * on which the requesting code placed the interrupt.
1032 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1035 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1041 * Drivers are often written to work w/o knowledge about the
1042 * underlying irq chip implementation, so a request for a
1043 * threaded irq without a primary hard irq context handler
1044 * requires the ONESHOT flag to be set. Some irq chips like
1045 * MSI based interrupts are per se one shot safe. Check the
1046 * chip flags, so we can avoid the unmask dance at the end of
1047 * the threaded handler for those.
1049 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1050 new->flags &= ~IRQF_ONESHOT;
1053 * The following block of code has to be executed atomically
1055 raw_spin_lock_irqsave(&desc->lock, flags);
1056 old_ptr = &desc->action;
1060 * Can't share interrupts unless both agree to and are
1061 * the same type (level, edge, polarity). So both flag
1062 * fields must have IRQF_SHARED set and the bits which
1063 * set the trigger type must match. Also all must
1066 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1067 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1068 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1071 /* All handlers must agree on per-cpuness */
1072 if ((old->flags & IRQF_PERCPU) !=
1073 (new->flags & IRQF_PERCPU))
1076 /* add new interrupt at end of irq queue */
1079 * Or all existing action->thread_mask bits,
1080 * so we can find the next zero bit for this
1083 thread_mask |= old->thread_mask;
1084 old_ptr = &old->next;
1091 * Setup the thread mask for this irqaction for ONESHOT. For
1092 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1093 * conditional in irq_wake_thread().
1095 if (new->flags & IRQF_ONESHOT) {
1097 * Unlikely to have 32 resp 64 irqs sharing one line,
1100 if (thread_mask == ~0UL) {
1105 * The thread_mask for the action is or'ed to
1106 * desc->thread_active to indicate that the
1107 * IRQF_ONESHOT thread handler has been woken, but not
1108 * yet finished. The bit is cleared when a thread
1109 * completes. When all threads of a shared interrupt
1110 * line have completed desc->threads_active becomes
1111 * zero and the interrupt line is unmasked. See
1112 * handle.c:irq_wake_thread() for further information.
1114 * If no thread is woken by primary (hard irq context)
1115 * interrupt handlers, then desc->threads_active is
1116 * also checked for zero to unmask the irq line in the
1117 * affected hard irq flow handlers
1118 * (handle_[fasteoi|level]_irq).
1120 * The new action gets the first zero bit of
1121 * thread_mask assigned. See the loop above which or's
1122 * all existing action->thread_mask bits.
1124 new->thread_mask = 1 << ffz(thread_mask);
1126 } else if (new->handler == irq_default_primary_handler &&
1127 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1129 * The interrupt was requested with handler = NULL, so
1130 * we use the default primary handler for it. But it
1131 * does not have the oneshot flag set. In combination
1132 * with level interrupts this is deadly, because the
1133 * default primary handler just wakes the thread, then
1134 * the irq lines is reenabled, but the device still
1135 * has the level irq asserted. Rinse and repeat....
1137 * While this works for edge type interrupts, we play
1138 * it safe and reject unconditionally because we can't
1139 * say for sure which type this interrupt really
1140 * has. The type flags are unreliable as the
1141 * underlying chip implementation can override them.
1143 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1150 ret = irq_request_resources(desc);
1152 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1153 new->name, irq, desc->irq_data.chip->name);
1157 init_waitqueue_head(&desc->wait_for_threads);
1159 /* Setup the type (level, edge polarity) if configured: */
1160 if (new->flags & IRQF_TRIGGER_MASK) {
1161 ret = __irq_set_trigger(desc, irq,
1162 new->flags & IRQF_TRIGGER_MASK);
1168 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1169 IRQS_ONESHOT | IRQS_WAITING);
1170 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1172 if (new->flags & IRQF_PERCPU) {
1173 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1174 irq_settings_set_per_cpu(desc);
1177 if (new->flags & IRQF_ONESHOT)
1178 desc->istate |= IRQS_ONESHOT;
1180 if (irq_settings_can_autoenable(desc))
1181 irq_startup(desc, true);
1183 /* Undo nested disables: */
1186 /* Exclude IRQ from balancing if requested */
1187 if (new->flags & IRQF_NOBALANCING) {
1188 irq_settings_set_no_balancing(desc);
1189 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1192 /* Set default affinity mask once everything is setup */
1193 setup_affinity(irq, desc, mask);
1195 } else if (new->flags & IRQF_TRIGGER_MASK) {
1196 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1197 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1200 /* hope the handler works with current trigger mode */
1201 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1208 irq_pm_install_action(desc, new);
1210 /* Reset broken irq detection when installing new handler */
1211 desc->irq_count = 0;
1212 desc->irqs_unhandled = 0;
1215 * Check whether we disabled the irq via the spurious handler
1216 * before. Reenable it and give it another chance.
1218 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1219 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1220 __enable_irq(desc, irq);
1223 raw_spin_unlock_irqrestore(&desc->lock, flags);
1226 * Strictly no need to wake it up, but hung_task complains
1227 * when no hard interrupt wakes the thread up.
1230 wake_up_process(new->thread);
1232 register_irq_proc(irq, desc);
1234 register_handler_proc(irq, new);
1235 free_cpumask_var(mask);
1240 if (!(new->flags & IRQF_PROBE_SHARED)) {
1241 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1242 irq, new->flags, new->name, old->flags, old->name);
1243 #ifdef CONFIG_DEBUG_SHIRQ
1250 raw_spin_unlock_irqrestore(&desc->lock, flags);
1251 free_cpumask_var(mask);
1255 struct task_struct *t = new->thread;
1262 module_put(desc->owner);
1267 * setup_irq - setup an interrupt
1268 * @irq: Interrupt line to setup
1269 * @act: irqaction for the interrupt
1271 * Used to statically setup interrupts in the early boot process.
1273 int setup_irq(unsigned int irq, struct irqaction *act)
1276 struct irq_desc *desc = irq_to_desc(irq);
1278 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1280 chip_bus_lock(desc);
1281 retval = __setup_irq(irq, desc, act);
1282 chip_bus_sync_unlock(desc);
1286 EXPORT_SYMBOL_GPL(setup_irq);
1289 * Internal function to unregister an irqaction - used to free
1290 * regular and special interrupts that are part of the architecture.
1292 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1294 struct irq_desc *desc = irq_to_desc(irq);
1295 struct irqaction *action, **action_ptr;
1296 unsigned long flags;
1298 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1303 raw_spin_lock_irqsave(&desc->lock, flags);
1306 * There can be multiple actions per IRQ descriptor, find the right
1307 * one based on the dev_id:
1309 action_ptr = &desc->action;
1311 action = *action_ptr;
1314 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1315 raw_spin_unlock_irqrestore(&desc->lock, flags);
1320 if (action->dev_id == dev_id)
1322 action_ptr = &action->next;
1325 /* Found it - now remove it from the list of entries: */
1326 *action_ptr = action->next;
1328 irq_pm_remove_action(desc, action);
1330 /* If this was the last handler, shut down the IRQ line: */
1331 if (!desc->action) {
1333 irq_release_resources(desc);
1337 /* make sure affinity_hint is cleaned up */
1338 if (WARN_ON_ONCE(desc->affinity_hint))
1339 desc->affinity_hint = NULL;
1342 raw_spin_unlock_irqrestore(&desc->lock, flags);
1344 unregister_handler_proc(irq, action);
1346 /* Make sure it's not being used on another CPU: */
1347 synchronize_irq(irq);
1349 #ifdef CONFIG_DEBUG_SHIRQ
1351 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1352 * event to happen even now it's being freed, so let's make sure that
1353 * is so by doing an extra call to the handler ....
1355 * ( We do this after actually deregistering it, to make sure that a
1356 * 'real' IRQ doesn't run in * parallel with our fake. )
1358 if (action->flags & IRQF_SHARED) {
1359 local_irq_save(flags);
1360 action->handler(irq, dev_id);
1361 local_irq_restore(flags);
1365 if (action->thread) {
1366 kthread_stop(action->thread);
1367 put_task_struct(action->thread);
1370 module_put(desc->owner);
1375 * remove_irq - free an interrupt
1376 * @irq: Interrupt line to free
1377 * @act: irqaction for the interrupt
1379 * Used to remove interrupts statically setup by the early boot process.
1381 void remove_irq(unsigned int irq, struct irqaction *act)
1383 struct irq_desc *desc = irq_to_desc(irq);
1385 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1386 __free_irq(irq, act->dev_id);
1388 EXPORT_SYMBOL_GPL(remove_irq);
1391 * free_irq - free an interrupt allocated with request_irq
1392 * @irq: Interrupt line to free
1393 * @dev_id: Device identity to free
1395 * Remove an interrupt handler. The handler is removed and if the
1396 * interrupt line is no longer in use by any driver it is disabled.
1397 * On a shared IRQ the caller must ensure the interrupt is disabled
1398 * on the card it drives before calling this function. The function
1399 * does not return until any executing interrupts for this IRQ
1402 * This function must not be called from interrupt context.
1404 void free_irq(unsigned int irq, void *dev_id)
1406 struct irq_desc *desc = irq_to_desc(irq);
1408 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1412 if (WARN_ON(desc->affinity_notify))
1413 desc->affinity_notify = NULL;
1416 chip_bus_lock(desc);
1417 kfree(__free_irq(irq, dev_id));
1418 chip_bus_sync_unlock(desc);
1420 EXPORT_SYMBOL(free_irq);
1423 * request_threaded_irq - allocate an interrupt line
1424 * @irq: Interrupt line to allocate
1425 * @handler: Function to be called when the IRQ occurs.
1426 * Primary handler for threaded interrupts
1427 * If NULL and thread_fn != NULL the default
1428 * primary handler is installed
1429 * @thread_fn: Function called from the irq handler thread
1430 * If NULL, no irq thread is created
1431 * @irqflags: Interrupt type flags
1432 * @devname: An ascii name for the claiming device
1433 * @dev_id: A cookie passed back to the handler function
1435 * This call allocates interrupt resources and enables the
1436 * interrupt line and IRQ handling. From the point this
1437 * call is made your handler function may be invoked. Since
1438 * your handler function must clear any interrupt the board
1439 * raises, you must take care both to initialise your hardware
1440 * and to set up the interrupt handler in the right order.
1442 * If you want to set up a threaded irq handler for your device
1443 * then you need to supply @handler and @thread_fn. @handler is
1444 * still called in hard interrupt context and has to check
1445 * whether the interrupt originates from the device. If yes it
1446 * needs to disable the interrupt on the device and return
1447 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1448 * @thread_fn. This split handler design is necessary to support
1449 * shared interrupts.
1451 * Dev_id must be globally unique. Normally the address of the
1452 * device data structure is used as the cookie. Since the handler
1453 * receives this value it makes sense to use it.
1455 * If your interrupt is shared you must pass a non NULL dev_id
1456 * as this is required when freeing the interrupt.
1460 * IRQF_SHARED Interrupt is shared
1461 * IRQF_TRIGGER_* Specify active edge(s) or level
1464 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1465 irq_handler_t thread_fn, unsigned long irqflags,
1466 const char *devname, void *dev_id)
1468 struct irqaction *action;
1469 struct irq_desc *desc;
1473 * Sanity-check: shared interrupts must pass in a real dev-ID,
1474 * otherwise we'll have trouble later trying to figure out
1475 * which interrupt is which (messes up the interrupt freeing
1478 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1479 * it cannot be set along with IRQF_NO_SUSPEND.
1481 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1482 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1483 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1486 desc = irq_to_desc(irq);
1490 if (!irq_settings_can_request(desc) ||
1491 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1497 handler = irq_default_primary_handler;
1500 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1504 action->handler = handler;
1505 action->thread_fn = thread_fn;
1506 action->flags = irqflags;
1507 action->name = devname;
1508 action->dev_id = dev_id;
1510 chip_bus_lock(desc);
1511 retval = __setup_irq(irq, desc, action);
1512 chip_bus_sync_unlock(desc);
1517 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1518 if (!retval && (irqflags & IRQF_SHARED)) {
1520 * It's a shared IRQ -- the driver ought to be prepared for it
1521 * to happen immediately, so let's make sure....
1522 * We disable the irq to make sure that a 'real' IRQ doesn't
1523 * run in parallel with our fake.
1525 unsigned long flags;
1528 local_irq_save(flags);
1530 handler(irq, dev_id);
1532 local_irq_restore(flags);
1538 EXPORT_SYMBOL(request_threaded_irq);
1541 * request_any_context_irq - allocate an interrupt line
1542 * @irq: Interrupt line to allocate
1543 * @handler: Function to be called when the IRQ occurs.
1544 * Threaded handler for threaded interrupts.
1545 * @flags: Interrupt type flags
1546 * @name: An ascii name for the claiming device
1547 * @dev_id: A cookie passed back to the handler function
1549 * This call allocates interrupt resources and enables the
1550 * interrupt line and IRQ handling. It selects either a
1551 * hardirq or threaded handling method depending on the
1554 * On failure, it returns a negative value. On success,
1555 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1557 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1558 unsigned long flags, const char *name, void *dev_id)
1560 struct irq_desc *desc = irq_to_desc(irq);
1566 if (irq_settings_is_nested_thread(desc)) {
1567 ret = request_threaded_irq(irq, NULL, handler,
1568 flags, name, dev_id);
1569 return !ret ? IRQC_IS_NESTED : ret;
1572 ret = request_irq(irq, handler, flags, name, dev_id);
1573 return !ret ? IRQC_IS_HARDIRQ : ret;
1575 EXPORT_SYMBOL_GPL(request_any_context_irq);
1577 void enable_percpu_irq(unsigned int irq, unsigned int type)
1579 unsigned int cpu = smp_processor_id();
1580 unsigned long flags;
1581 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1586 type &= IRQ_TYPE_SENSE_MASK;
1587 if (type != IRQ_TYPE_NONE) {
1590 ret = __irq_set_trigger(desc, irq, type);
1593 WARN(1, "failed to set type for IRQ%d\n", irq);
1598 irq_percpu_enable(desc, cpu);
1600 irq_put_desc_unlock(desc, flags);
1602 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1604 void disable_percpu_irq(unsigned int irq)
1606 unsigned int cpu = smp_processor_id();
1607 unsigned long flags;
1608 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1613 irq_percpu_disable(desc, cpu);
1614 irq_put_desc_unlock(desc, flags);
1616 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1619 * Internal function to unregister a percpu irqaction.
1621 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1623 struct irq_desc *desc = irq_to_desc(irq);
1624 struct irqaction *action;
1625 unsigned long flags;
1627 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1632 raw_spin_lock_irqsave(&desc->lock, flags);
1634 action = desc->action;
1635 if (!action || action->percpu_dev_id != dev_id) {
1636 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1640 if (!cpumask_empty(desc->percpu_enabled)) {
1641 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1642 irq, cpumask_first(desc->percpu_enabled));
1646 /* Found it - now remove it from the list of entries: */
1647 desc->action = NULL;
1649 raw_spin_unlock_irqrestore(&desc->lock, flags);
1651 unregister_handler_proc(irq, action);
1653 module_put(desc->owner);
1657 raw_spin_unlock_irqrestore(&desc->lock, flags);
1662 * remove_percpu_irq - free a per-cpu interrupt
1663 * @irq: Interrupt line to free
1664 * @act: irqaction for the interrupt
1666 * Used to remove interrupts statically setup by the early boot process.
1668 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1670 struct irq_desc *desc = irq_to_desc(irq);
1672 if (desc && irq_settings_is_per_cpu_devid(desc))
1673 __free_percpu_irq(irq, act->percpu_dev_id);
1677 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1678 * @irq: Interrupt line to free
1679 * @dev_id: Device identity to free
1681 * Remove a percpu interrupt handler. The handler is removed, but
1682 * the interrupt line is not disabled. This must be done on each
1683 * CPU before calling this function. The function does not return
1684 * until any executing interrupts for this IRQ have completed.
1686 * This function must not be called from interrupt context.
1688 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1690 struct irq_desc *desc = irq_to_desc(irq);
1692 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1695 chip_bus_lock(desc);
1696 kfree(__free_percpu_irq(irq, dev_id));
1697 chip_bus_sync_unlock(desc);
1701 * setup_percpu_irq - setup a per-cpu interrupt
1702 * @irq: Interrupt line to setup
1703 * @act: irqaction for the interrupt
1705 * Used to statically setup per-cpu interrupts in the early boot process.
1707 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1709 struct irq_desc *desc = irq_to_desc(irq);
1712 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1714 chip_bus_lock(desc);
1715 retval = __setup_irq(irq, desc, act);
1716 chip_bus_sync_unlock(desc);
1722 * request_percpu_irq - allocate a percpu interrupt line
1723 * @irq: Interrupt line to allocate
1724 * @handler: Function to be called when the IRQ occurs.
1725 * @devname: An ascii name for the claiming device
1726 * @dev_id: A percpu cookie passed back to the handler function
1728 * This call allocates interrupt resources, but doesn't
1729 * automatically enable the interrupt. It has to be done on each
1730 * CPU using enable_percpu_irq().
1732 * Dev_id must be globally unique. It is a per-cpu variable, and
1733 * the handler gets called with the interrupted CPU's instance of
1736 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1737 const char *devname, void __percpu *dev_id)
1739 struct irqaction *action;
1740 struct irq_desc *desc;
1746 desc = irq_to_desc(irq);
1747 if (!desc || !irq_settings_can_request(desc) ||
1748 !irq_settings_is_per_cpu_devid(desc))
1751 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1755 action->handler = handler;
1756 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1757 action->name = devname;
1758 action->percpu_dev_id = dev_id;
1760 chip_bus_lock(desc);
1761 retval = __setup_irq(irq, desc, action);
1762 chip_bus_sync_unlock(desc);