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 * Returns: false if a threaded handler is active.
73 * This function may be called - with care - from IRQ context.
75 bool synchronize_hardirq(unsigned int irq)
77 struct irq_desc *desc = irq_to_desc(irq);
80 __synchronize_hardirq(desc);
81 return !atomic_read(&desc->threads_active);
86 EXPORT_SYMBOL(synchronize_hardirq);
89 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
90 * @irq: interrupt number to wait for
92 * This function waits for any pending IRQ handlers for this interrupt
93 * to complete before returning. If you use this function while
94 * holding a resource the IRQ handler may need you will deadlock.
96 * This function may be called - with care - from IRQ context.
98 void synchronize_irq(unsigned int irq)
100 struct irq_desc *desc = irq_to_desc(irq);
103 __synchronize_hardirq(desc);
105 * We made sure that no hardirq handler is
106 * running. Now verify that no threaded handlers are
109 wait_event(desc->wait_for_threads,
110 !atomic_read(&desc->threads_active));
113 EXPORT_SYMBOL(synchronize_irq);
116 cpumask_var_t irq_default_affinity;
119 * irq_can_set_affinity - Check if the affinity of a given irq can be set
120 * @irq: Interrupt to check
123 int irq_can_set_affinity(unsigned int irq)
125 struct irq_desc *desc = irq_to_desc(irq);
127 if (!desc || !irqd_can_balance(&desc->irq_data) ||
128 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
135 * irq_set_thread_affinity - Notify irq threads to adjust affinity
136 * @desc: irq descriptor which has affitnity changed
138 * We just set IRQTF_AFFINITY and delegate the affinity setting
139 * to the interrupt thread itself. We can not call
140 * set_cpus_allowed_ptr() here as we hold desc->lock and this
141 * code can be called from hard interrupt context.
143 void irq_set_thread_affinity(struct irq_desc *desc)
145 struct irqaction *action = desc->action;
149 set_bit(IRQTF_AFFINITY, &action->thread_flags);
150 action = action->next;
154 #ifdef CONFIG_GENERIC_PENDING_IRQ
155 static inline bool irq_can_move_pcntxt(struct irq_data *data)
157 return irqd_can_move_in_process_context(data);
159 static inline bool irq_move_pending(struct irq_data *data)
161 return irqd_is_setaffinity_pending(data);
164 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
166 cpumask_copy(desc->pending_mask, mask);
169 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
171 cpumask_copy(mask, desc->pending_mask);
174 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
175 static inline bool irq_move_pending(struct irq_data *data) { return false; }
177 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
179 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
182 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
185 struct irq_desc *desc = irq_data_to_desc(data);
186 struct irq_chip *chip = irq_data_get_irq_chip(data);
189 ret = chip->irq_set_affinity(data, mask, force);
191 case IRQ_SET_MASK_OK:
192 case IRQ_SET_MASK_OK_DONE:
193 cpumask_copy(data->affinity, mask);
194 case IRQ_SET_MASK_OK_NOCOPY:
195 irq_set_thread_affinity(desc);
202 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
205 struct irq_chip *chip = irq_data_get_irq_chip(data);
206 struct irq_desc *desc = irq_data_to_desc(data);
209 if (!chip || !chip->irq_set_affinity)
212 if (irq_can_move_pcntxt(data)) {
213 ret = irq_do_set_affinity(data, mask, force);
215 irqd_set_move_pending(data);
216 irq_copy_pending(desc, mask);
219 if (desc->affinity_notify) {
220 kref_get(&desc->affinity_notify->kref);
221 schedule_work(&desc->affinity_notify->work);
223 irqd_set(data, IRQD_AFFINITY_SET);
228 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
230 struct irq_desc *desc = irq_to_desc(irq);
237 raw_spin_lock_irqsave(&desc->lock, flags);
238 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
239 raw_spin_unlock_irqrestore(&desc->lock, flags);
243 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
246 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
250 desc->affinity_hint = m;
251 irq_put_desc_unlock(desc, flags);
252 /* set the initial affinity to prevent every interrupt being on CPU0 */
254 __irq_set_affinity(irq, m, false);
257 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
260 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
261 * @irq: interrupt number to set affinity
262 * @vcpu_info: vCPU specific data
264 * This function uses the vCPU specific data to set the vCPU
265 * affinity for an irq. The vCPU specific data is passed from
266 * outside, such as KVM. One example code path is as below:
267 * KVM -> IOMMU -> irq_set_vcpu_affinity().
269 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
272 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
273 struct irq_data *data;
274 struct irq_chip *chip;
280 data = irq_desc_get_irq_data(desc);
281 chip = irq_data_get_irq_chip(data);
282 if (chip && chip->irq_set_vcpu_affinity)
283 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
284 irq_put_desc_unlock(desc, flags);
288 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
290 static void irq_affinity_notify(struct work_struct *work)
292 struct irq_affinity_notify *notify =
293 container_of(work, struct irq_affinity_notify, work);
294 struct irq_desc *desc = irq_to_desc(notify->irq);
295 cpumask_var_t cpumask;
298 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
301 raw_spin_lock_irqsave(&desc->lock, flags);
302 if (irq_move_pending(&desc->irq_data))
303 irq_get_pending(cpumask, desc);
305 cpumask_copy(cpumask, desc->irq_data.affinity);
306 raw_spin_unlock_irqrestore(&desc->lock, flags);
308 notify->notify(notify, cpumask);
310 free_cpumask_var(cpumask);
312 kref_put(¬ify->kref, notify->release);
316 * irq_set_affinity_notifier - control notification of IRQ affinity changes
317 * @irq: Interrupt for which to enable/disable notification
318 * @notify: Context for notification, or %NULL to disable
319 * notification. Function pointers must be initialised;
320 * the other fields will be initialised by this function.
322 * Must be called in process context. Notification may only be enabled
323 * after the IRQ is allocated and must be disabled before the IRQ is
324 * freed using free_irq().
327 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
329 struct irq_desc *desc = irq_to_desc(irq);
330 struct irq_affinity_notify *old_notify;
333 /* The release function is promised process context */
339 /* Complete initialisation of *notify */
342 kref_init(¬ify->kref);
343 INIT_WORK(¬ify->work, irq_affinity_notify);
346 raw_spin_lock_irqsave(&desc->lock, flags);
347 old_notify = desc->affinity_notify;
348 desc->affinity_notify = notify;
349 raw_spin_unlock_irqrestore(&desc->lock, flags);
352 kref_put(&old_notify->kref, old_notify->release);
356 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
358 #ifndef CONFIG_AUTO_IRQ_AFFINITY
360 * Generic version of the affinity autoselector.
363 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
365 struct cpumask *set = irq_default_affinity;
366 int node = irq_desc_get_node(desc);
368 /* Excludes PER_CPU and NO_BALANCE interrupts */
369 if (!irq_can_set_affinity(irq))
373 * Preserve an userspace affinity setup, but make sure that
374 * one of the targets is online.
376 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
377 if (cpumask_intersects(desc->irq_data.affinity,
379 set = desc->irq_data.affinity;
381 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
384 cpumask_and(mask, cpu_online_mask, set);
385 if (node != NUMA_NO_NODE) {
386 const struct cpumask *nodemask = cpumask_of_node(node);
388 /* make sure at least one of the cpus in nodemask is online */
389 if (cpumask_intersects(mask, nodemask))
390 cpumask_and(mask, mask, nodemask);
392 irq_do_set_affinity(&desc->irq_data, mask, false);
397 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
399 return irq_select_affinity(irq);
404 * Called when affinity is set via /proc/irq
406 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
408 struct irq_desc *desc = irq_to_desc(irq);
412 raw_spin_lock_irqsave(&desc->lock, flags);
413 ret = setup_affinity(irq, desc, mask);
414 raw_spin_unlock_irqrestore(&desc->lock, flags);
420 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
426 void __disable_irq(struct irq_desc *desc, unsigned int irq)
432 static int __disable_irq_nosync(unsigned int irq)
435 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
439 __disable_irq(desc, irq);
440 irq_put_desc_busunlock(desc, flags);
445 * disable_irq_nosync - disable an irq without waiting
446 * @irq: Interrupt to disable
448 * Disable the selected interrupt line. Disables and Enables are
450 * Unlike disable_irq(), this function does not ensure existing
451 * instances of the IRQ handler have completed before returning.
453 * This function may be called from IRQ context.
455 void disable_irq_nosync(unsigned int irq)
457 __disable_irq_nosync(irq);
459 EXPORT_SYMBOL(disable_irq_nosync);
462 * disable_irq - disable an irq and wait for completion
463 * @irq: Interrupt to disable
465 * Disable the selected interrupt line. Enables and Disables are
467 * This function waits for any pending IRQ handlers for this interrupt
468 * to complete before returning. If you use this function while
469 * holding a resource the IRQ handler may need you will deadlock.
471 * This function may be called - with care - from IRQ context.
473 void disable_irq(unsigned int irq)
475 if (!__disable_irq_nosync(irq))
476 synchronize_irq(irq);
478 EXPORT_SYMBOL(disable_irq);
481 * disable_hardirq - disables an irq and waits for hardirq completion
482 * @irq: Interrupt to disable
484 * Disable the selected interrupt line. Enables and Disables are
486 * This function waits for any pending hard IRQ handlers for this
487 * interrupt to complete before returning. If you use this function while
488 * holding a resource the hard IRQ handler may need you will deadlock.
490 * When used to optimistically disable an interrupt from atomic context
491 * the return value must be checked.
493 * Returns: false if a threaded handler is active.
495 * This function may be called - with care - from IRQ context.
497 bool disable_hardirq(unsigned int irq)
499 if (!__disable_irq_nosync(irq))
500 return synchronize_hardirq(irq);
504 EXPORT_SYMBOL_GPL(disable_hardirq);
506 void __enable_irq(struct irq_desc *desc, unsigned int irq)
508 switch (desc->depth) {
511 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
514 if (desc->istate & IRQS_SUSPENDED)
516 /* Prevent probing on this irq: */
517 irq_settings_set_noprobe(desc);
519 check_irq_resend(desc, irq);
528 * enable_irq - enable handling of an irq
529 * @irq: Interrupt to enable
531 * Undoes the effect of one call to disable_irq(). If this
532 * matches the last disable, processing of interrupts on this
533 * IRQ line is re-enabled.
535 * This function may be called from IRQ context only when
536 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
538 void enable_irq(unsigned int irq)
541 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
545 if (WARN(!desc->irq_data.chip,
546 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
549 __enable_irq(desc, irq);
551 irq_put_desc_busunlock(desc, flags);
553 EXPORT_SYMBOL(enable_irq);
555 static int set_irq_wake_real(unsigned int irq, unsigned int on)
557 struct irq_desc *desc = irq_to_desc(irq);
560 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
563 if (desc->irq_data.chip->irq_set_wake)
564 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
570 * irq_set_irq_wake - control irq power management wakeup
571 * @irq: interrupt to control
572 * @on: enable/disable power management wakeup
574 * Enable/disable power management wakeup mode, which is
575 * disabled by default. Enables and disables must match,
576 * just as they match for non-wakeup mode support.
578 * Wakeup mode lets this IRQ wake the system from sleep
579 * states like "suspend to RAM".
581 int irq_set_irq_wake(unsigned int irq, unsigned int on)
584 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
590 /* wakeup-capable irqs can be shared between drivers that
591 * don't need to have the same sleep mode behaviors.
594 if (desc->wake_depth++ == 0) {
595 ret = set_irq_wake_real(irq, on);
597 desc->wake_depth = 0;
599 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
602 if (desc->wake_depth == 0) {
603 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
604 } else if (--desc->wake_depth == 0) {
605 ret = set_irq_wake_real(irq, on);
607 desc->wake_depth = 1;
609 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
612 irq_put_desc_busunlock(desc, flags);
615 EXPORT_SYMBOL(irq_set_irq_wake);
618 * Internal function that tells the architecture code whether a
619 * particular irq has been exclusively allocated or is available
622 int can_request_irq(unsigned int irq, unsigned long irqflags)
625 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
631 if (irq_settings_can_request(desc)) {
633 irqflags & desc->action->flags & IRQF_SHARED)
636 irq_put_desc_unlock(desc, flags);
640 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
643 struct irq_chip *chip = desc->irq_data.chip;
646 if (!chip || !chip->irq_set_type) {
648 * IRQF_TRIGGER_* but the PIC does not support multiple
651 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
652 chip ? (chip->name ? : "unknown") : "unknown");
656 flags &= IRQ_TYPE_SENSE_MASK;
658 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
659 if (!irqd_irq_masked(&desc->irq_data))
661 if (!irqd_irq_disabled(&desc->irq_data))
665 /* caller masked out all except trigger mode flags */
666 ret = chip->irq_set_type(&desc->irq_data, flags);
669 case IRQ_SET_MASK_OK:
670 case IRQ_SET_MASK_OK_DONE:
671 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
672 irqd_set(&desc->irq_data, flags);
674 case IRQ_SET_MASK_OK_NOCOPY:
675 flags = irqd_get_trigger_type(&desc->irq_data);
676 irq_settings_set_trigger_mask(desc, flags);
677 irqd_clear(&desc->irq_data, IRQD_LEVEL);
678 irq_settings_clr_level(desc);
679 if (flags & IRQ_TYPE_LEVEL_MASK) {
680 irq_settings_set_level(desc);
681 irqd_set(&desc->irq_data, IRQD_LEVEL);
687 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
688 flags, irq, chip->irq_set_type);
695 #ifdef CONFIG_HARDIRQS_SW_RESEND
696 int irq_set_parent(int irq, int parent_irq)
699 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
704 desc->parent_irq = parent_irq;
706 irq_put_desc_unlock(desc, flags);
712 * Default primary interrupt handler for threaded interrupts. Is
713 * assigned as primary handler when request_threaded_irq is called
714 * with handler == NULL. Useful for oneshot interrupts.
716 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
718 return IRQ_WAKE_THREAD;
722 * Primary handler for nested threaded interrupts. Should never be
725 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
727 WARN(1, "Primary handler called for nested irq %d\n", irq);
731 static int irq_wait_for_interrupt(struct irqaction *action)
733 set_current_state(TASK_INTERRUPTIBLE);
735 while (!kthread_should_stop()) {
737 if (test_and_clear_bit(IRQTF_RUNTHREAD,
738 &action->thread_flags)) {
739 __set_current_state(TASK_RUNNING);
743 set_current_state(TASK_INTERRUPTIBLE);
745 __set_current_state(TASK_RUNNING);
750 * Oneshot interrupts keep the irq line masked until the threaded
751 * handler finished. unmask if the interrupt has not been disabled and
754 static void irq_finalize_oneshot(struct irq_desc *desc,
755 struct irqaction *action)
757 if (!(desc->istate & IRQS_ONESHOT))
761 raw_spin_lock_irq(&desc->lock);
764 * Implausible though it may be we need to protect us against
765 * the following scenario:
767 * The thread is faster done than the hard interrupt handler
768 * on the other CPU. If we unmask the irq line then the
769 * interrupt can come in again and masks the line, leaves due
770 * to IRQS_INPROGRESS and the irq line is masked forever.
772 * This also serializes the state of shared oneshot handlers
773 * versus "desc->threads_onehsot |= action->thread_mask;" in
774 * irq_wake_thread(). See the comment there which explains the
777 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
778 raw_spin_unlock_irq(&desc->lock);
779 chip_bus_sync_unlock(desc);
785 * Now check again, whether the thread should run. Otherwise
786 * we would clear the threads_oneshot bit of this thread which
789 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
792 desc->threads_oneshot &= ~action->thread_mask;
794 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
795 irqd_irq_masked(&desc->irq_data))
796 unmask_threaded_irq(desc);
799 raw_spin_unlock_irq(&desc->lock);
800 chip_bus_sync_unlock(desc);
805 * Check whether we need to change the affinity of the interrupt thread.
808 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
813 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
817 * In case we are out of memory we set IRQTF_AFFINITY again and
818 * try again next time
820 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
821 set_bit(IRQTF_AFFINITY, &action->thread_flags);
825 raw_spin_lock_irq(&desc->lock);
827 * This code is triggered unconditionally. Check the affinity
828 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
830 if (desc->irq_data.affinity)
831 cpumask_copy(mask, desc->irq_data.affinity);
834 raw_spin_unlock_irq(&desc->lock);
837 set_cpus_allowed_ptr(current, mask);
838 free_cpumask_var(mask);
842 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
846 * Interrupts which are not explicitely requested as threaded
847 * interrupts rely on the implicit bh/preempt disable of the hard irq
848 * context. So we need to disable bh here to avoid deadlocks and other
852 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
857 ret = action->thread_fn(action->irq, action->dev_id);
858 irq_finalize_oneshot(desc, action);
864 * Interrupts explicitly requested as threaded interrupts want to be
865 * preemtible - many of them need to sleep and wait for slow busses to
868 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
869 struct irqaction *action)
873 ret = action->thread_fn(action->irq, action->dev_id);
874 irq_finalize_oneshot(desc, action);
878 static void wake_threads_waitq(struct irq_desc *desc)
880 if (atomic_dec_and_test(&desc->threads_active))
881 wake_up(&desc->wait_for_threads);
884 static void irq_thread_dtor(struct callback_head *unused)
886 struct task_struct *tsk = current;
887 struct irq_desc *desc;
888 struct irqaction *action;
890 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
893 action = kthread_data(tsk);
895 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
896 tsk->comm, tsk->pid, action->irq);
899 desc = irq_to_desc(action->irq);
901 * If IRQTF_RUNTHREAD is set, we need to decrement
902 * desc->threads_active and wake possible waiters.
904 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
905 wake_threads_waitq(desc);
907 /* Prevent a stale desc->threads_oneshot */
908 irq_finalize_oneshot(desc, action);
912 * Interrupt handler thread
914 static int irq_thread(void *data)
916 struct callback_head on_exit_work;
917 struct irqaction *action = data;
918 struct irq_desc *desc = irq_to_desc(action->irq);
919 irqreturn_t (*handler_fn)(struct irq_desc *desc,
920 struct irqaction *action);
922 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
923 &action->thread_flags))
924 handler_fn = irq_forced_thread_fn;
926 handler_fn = irq_thread_fn;
928 init_task_work(&on_exit_work, irq_thread_dtor);
929 task_work_add(current, &on_exit_work, false);
931 irq_thread_check_affinity(desc, action);
933 while (!irq_wait_for_interrupt(action)) {
934 irqreturn_t action_ret;
936 irq_thread_check_affinity(desc, action);
938 action_ret = handler_fn(desc, action);
939 if (action_ret == IRQ_HANDLED)
940 atomic_inc(&desc->threads_handled);
942 wake_threads_waitq(desc);
946 * This is the regular exit path. __free_irq() is stopping the
947 * thread via kthread_stop() after calling
948 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
949 * oneshot mask bit can be set. We cannot verify that as we
950 * cannot touch the oneshot mask at this point anymore as
951 * __setup_irq() might have given out currents thread_mask
954 task_work_cancel(current, irq_thread_dtor);
959 * irq_wake_thread - wake the irq thread for the action identified by dev_id
960 * @irq: Interrupt line
961 * @dev_id: Device identity for which the thread should be woken
964 void irq_wake_thread(unsigned int irq, void *dev_id)
966 struct irq_desc *desc = irq_to_desc(irq);
967 struct irqaction *action;
970 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
973 raw_spin_lock_irqsave(&desc->lock, flags);
974 for (action = desc->action; action; action = action->next) {
975 if (action->dev_id == dev_id) {
977 __irq_wake_thread(desc, action);
981 raw_spin_unlock_irqrestore(&desc->lock, flags);
983 EXPORT_SYMBOL_GPL(irq_wake_thread);
985 static void irq_setup_forced_threading(struct irqaction *new)
987 if (!force_irqthreads)
989 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
992 new->flags |= IRQF_ONESHOT;
994 if (!new->thread_fn) {
995 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
996 new->thread_fn = new->handler;
997 new->handler = irq_default_primary_handler;
1001 static int irq_request_resources(struct irq_desc *desc)
1003 struct irq_data *d = &desc->irq_data;
1004 struct irq_chip *c = d->chip;
1006 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1009 static void irq_release_resources(struct irq_desc *desc)
1011 struct irq_data *d = &desc->irq_data;
1012 struct irq_chip *c = d->chip;
1014 if (c->irq_release_resources)
1015 c->irq_release_resources(d);
1019 * Internal function to register an irqaction - typically used to
1020 * allocate special interrupts that are part of the architecture.
1023 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1025 struct irqaction *old, **old_ptr;
1026 unsigned long flags, thread_mask = 0;
1027 int ret, nested, shared = 0;
1033 if (desc->irq_data.chip == &no_irq_chip)
1035 if (!try_module_get(desc->owner))
1039 * Check whether the interrupt nests into another interrupt
1042 nested = irq_settings_is_nested_thread(desc);
1044 if (!new->thread_fn) {
1049 * Replace the primary handler which was provided from
1050 * the driver for non nested interrupt handling by the
1051 * dummy function which warns when called.
1053 new->handler = irq_nested_primary_handler;
1055 if (irq_settings_can_thread(desc))
1056 irq_setup_forced_threading(new);
1060 * Create a handler thread when a thread function is supplied
1061 * and the interrupt does not nest into another interrupt
1064 if (new->thread_fn && !nested) {
1065 struct task_struct *t;
1066 static const struct sched_param param = {
1067 .sched_priority = MAX_USER_RT_PRIO/2,
1070 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1077 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1080 * We keep the reference to the task struct even if
1081 * the thread dies to avoid that the interrupt code
1082 * references an already freed task_struct.
1087 * Tell the thread to set its affinity. This is
1088 * important for shared interrupt handlers as we do
1089 * not invoke setup_affinity() for the secondary
1090 * handlers as everything is already set up. Even for
1091 * interrupts marked with IRQF_NO_BALANCE this is
1092 * correct as we want the thread to move to the cpu(s)
1093 * on which the requesting code placed the interrupt.
1095 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1098 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1104 * Drivers are often written to work w/o knowledge about the
1105 * underlying irq chip implementation, so a request for a
1106 * threaded irq without a primary hard irq context handler
1107 * requires the ONESHOT flag to be set. Some irq chips like
1108 * MSI based interrupts are per se one shot safe. Check the
1109 * chip flags, so we can avoid the unmask dance at the end of
1110 * the threaded handler for those.
1112 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1113 new->flags &= ~IRQF_ONESHOT;
1116 * The following block of code has to be executed atomically
1118 raw_spin_lock_irqsave(&desc->lock, flags);
1119 old_ptr = &desc->action;
1123 * Can't share interrupts unless both agree to and are
1124 * the same type (level, edge, polarity). So both flag
1125 * fields must have IRQF_SHARED set and the bits which
1126 * set the trigger type must match. Also all must
1129 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1130 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1131 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1134 /* All handlers must agree on per-cpuness */
1135 if ((old->flags & IRQF_PERCPU) !=
1136 (new->flags & IRQF_PERCPU))
1139 /* add new interrupt at end of irq queue */
1142 * Or all existing action->thread_mask bits,
1143 * so we can find the next zero bit for this
1146 thread_mask |= old->thread_mask;
1147 old_ptr = &old->next;
1154 * Setup the thread mask for this irqaction for ONESHOT. For
1155 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1156 * conditional in irq_wake_thread().
1158 if (new->flags & IRQF_ONESHOT) {
1160 * Unlikely to have 32 resp 64 irqs sharing one line,
1163 if (thread_mask == ~0UL) {
1168 * The thread_mask for the action is or'ed to
1169 * desc->thread_active to indicate that the
1170 * IRQF_ONESHOT thread handler has been woken, but not
1171 * yet finished. The bit is cleared when a thread
1172 * completes. When all threads of a shared interrupt
1173 * line have completed desc->threads_active becomes
1174 * zero and the interrupt line is unmasked. See
1175 * handle.c:irq_wake_thread() for further information.
1177 * If no thread is woken by primary (hard irq context)
1178 * interrupt handlers, then desc->threads_active is
1179 * also checked for zero to unmask the irq line in the
1180 * affected hard irq flow handlers
1181 * (handle_[fasteoi|level]_irq).
1183 * The new action gets the first zero bit of
1184 * thread_mask assigned. See the loop above which or's
1185 * all existing action->thread_mask bits.
1187 new->thread_mask = 1 << ffz(thread_mask);
1189 } else if (new->handler == irq_default_primary_handler &&
1190 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1192 * The interrupt was requested with handler = NULL, so
1193 * we use the default primary handler for it. But it
1194 * does not have the oneshot flag set. In combination
1195 * with level interrupts this is deadly, because the
1196 * default primary handler just wakes the thread, then
1197 * the irq lines is reenabled, but the device still
1198 * has the level irq asserted. Rinse and repeat....
1200 * While this works for edge type interrupts, we play
1201 * it safe and reject unconditionally because we can't
1202 * say for sure which type this interrupt really
1203 * has. The type flags are unreliable as the
1204 * underlying chip implementation can override them.
1206 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1213 ret = irq_request_resources(desc);
1215 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1216 new->name, irq, desc->irq_data.chip->name);
1220 init_waitqueue_head(&desc->wait_for_threads);
1222 /* Setup the type (level, edge polarity) if configured: */
1223 if (new->flags & IRQF_TRIGGER_MASK) {
1224 ret = __irq_set_trigger(desc, irq,
1225 new->flags & IRQF_TRIGGER_MASK);
1231 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1232 IRQS_ONESHOT | IRQS_WAITING);
1233 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1235 if (new->flags & IRQF_PERCPU) {
1236 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1237 irq_settings_set_per_cpu(desc);
1240 if (new->flags & IRQF_ONESHOT)
1241 desc->istate |= IRQS_ONESHOT;
1243 if (irq_settings_can_autoenable(desc))
1244 irq_startup(desc, true);
1246 /* Undo nested disables: */
1249 /* Exclude IRQ from balancing if requested */
1250 if (new->flags & IRQF_NOBALANCING) {
1251 irq_settings_set_no_balancing(desc);
1252 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1255 /* Set default affinity mask once everything is setup */
1256 setup_affinity(irq, desc, mask);
1258 } else if (new->flags & IRQF_TRIGGER_MASK) {
1259 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1260 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1263 /* hope the handler works with current trigger mode */
1264 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1271 irq_pm_install_action(desc, new);
1273 /* Reset broken irq detection when installing new handler */
1274 desc->irq_count = 0;
1275 desc->irqs_unhandled = 0;
1278 * Check whether we disabled the irq via the spurious handler
1279 * before. Reenable it and give it another chance.
1281 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1282 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1283 __enable_irq(desc, irq);
1286 raw_spin_unlock_irqrestore(&desc->lock, flags);
1289 * Strictly no need to wake it up, but hung_task complains
1290 * when no hard interrupt wakes the thread up.
1293 wake_up_process(new->thread);
1295 register_irq_proc(irq, desc);
1297 register_handler_proc(irq, new);
1298 free_cpumask_var(mask);
1303 if (!(new->flags & IRQF_PROBE_SHARED)) {
1304 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1305 irq, new->flags, new->name, old->flags, old->name);
1306 #ifdef CONFIG_DEBUG_SHIRQ
1313 raw_spin_unlock_irqrestore(&desc->lock, flags);
1314 free_cpumask_var(mask);
1318 struct task_struct *t = new->thread;
1325 module_put(desc->owner);
1330 * setup_irq - setup an interrupt
1331 * @irq: Interrupt line to setup
1332 * @act: irqaction for the interrupt
1334 * Used to statically setup interrupts in the early boot process.
1336 int setup_irq(unsigned int irq, struct irqaction *act)
1339 struct irq_desc *desc = irq_to_desc(irq);
1341 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1343 chip_bus_lock(desc);
1344 retval = __setup_irq(irq, desc, act);
1345 chip_bus_sync_unlock(desc);
1349 EXPORT_SYMBOL_GPL(setup_irq);
1352 * Internal function to unregister an irqaction - used to free
1353 * regular and special interrupts that are part of the architecture.
1355 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1357 struct irq_desc *desc = irq_to_desc(irq);
1358 struct irqaction *action, **action_ptr;
1359 unsigned long flags;
1361 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1366 raw_spin_lock_irqsave(&desc->lock, flags);
1369 * There can be multiple actions per IRQ descriptor, find the right
1370 * one based on the dev_id:
1372 action_ptr = &desc->action;
1374 action = *action_ptr;
1377 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1378 raw_spin_unlock_irqrestore(&desc->lock, flags);
1383 if (action->dev_id == dev_id)
1385 action_ptr = &action->next;
1388 /* Found it - now remove it from the list of entries: */
1389 *action_ptr = action->next;
1391 irq_pm_remove_action(desc, action);
1393 /* If this was the last handler, shut down the IRQ line: */
1394 if (!desc->action) {
1396 irq_release_resources(desc);
1400 /* make sure affinity_hint is cleaned up */
1401 if (WARN_ON_ONCE(desc->affinity_hint))
1402 desc->affinity_hint = NULL;
1405 raw_spin_unlock_irqrestore(&desc->lock, flags);
1407 unregister_handler_proc(irq, action);
1409 /* Make sure it's not being used on another CPU: */
1410 synchronize_irq(irq);
1412 #ifdef CONFIG_DEBUG_SHIRQ
1414 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1415 * event to happen even now it's being freed, so let's make sure that
1416 * is so by doing an extra call to the handler ....
1418 * ( We do this after actually deregistering it, to make sure that a
1419 * 'real' IRQ doesn't run in * parallel with our fake. )
1421 if (action->flags & IRQF_SHARED) {
1422 local_irq_save(flags);
1423 action->handler(irq, dev_id);
1424 local_irq_restore(flags);
1428 if (action->thread) {
1429 kthread_stop(action->thread);
1430 put_task_struct(action->thread);
1433 module_put(desc->owner);
1438 * remove_irq - free an interrupt
1439 * @irq: Interrupt line to free
1440 * @act: irqaction for the interrupt
1442 * Used to remove interrupts statically setup by the early boot process.
1444 void remove_irq(unsigned int irq, struct irqaction *act)
1446 struct irq_desc *desc = irq_to_desc(irq);
1448 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1449 __free_irq(irq, act->dev_id);
1451 EXPORT_SYMBOL_GPL(remove_irq);
1454 * free_irq - free an interrupt allocated with request_irq
1455 * @irq: Interrupt line to free
1456 * @dev_id: Device identity to free
1458 * Remove an interrupt handler. The handler is removed and if the
1459 * interrupt line is no longer in use by any driver it is disabled.
1460 * On a shared IRQ the caller must ensure the interrupt is disabled
1461 * on the card it drives before calling this function. The function
1462 * does not return until any executing interrupts for this IRQ
1465 * This function must not be called from interrupt context.
1467 void free_irq(unsigned int irq, void *dev_id)
1469 struct irq_desc *desc = irq_to_desc(irq);
1471 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1475 if (WARN_ON(desc->affinity_notify))
1476 desc->affinity_notify = NULL;
1479 chip_bus_lock(desc);
1480 kfree(__free_irq(irq, dev_id));
1481 chip_bus_sync_unlock(desc);
1483 EXPORT_SYMBOL(free_irq);
1486 * request_threaded_irq - allocate an interrupt line
1487 * @irq: Interrupt line to allocate
1488 * @handler: Function to be called when the IRQ occurs.
1489 * Primary handler for threaded interrupts
1490 * If NULL and thread_fn != NULL the default
1491 * primary handler is installed
1492 * @thread_fn: Function called from the irq handler thread
1493 * If NULL, no irq thread is created
1494 * @irqflags: Interrupt type flags
1495 * @devname: An ascii name for the claiming device
1496 * @dev_id: A cookie passed back to the handler function
1498 * This call allocates interrupt resources and enables the
1499 * interrupt line and IRQ handling. From the point this
1500 * call is made your handler function may be invoked. Since
1501 * your handler function must clear any interrupt the board
1502 * raises, you must take care both to initialise your hardware
1503 * and to set up the interrupt handler in the right order.
1505 * If you want to set up a threaded irq handler for your device
1506 * then you need to supply @handler and @thread_fn. @handler is
1507 * still called in hard interrupt context and has to check
1508 * whether the interrupt originates from the device. If yes it
1509 * needs to disable the interrupt on the device and return
1510 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1511 * @thread_fn. This split handler design is necessary to support
1512 * shared interrupts.
1514 * Dev_id must be globally unique. Normally the address of the
1515 * device data structure is used as the cookie. Since the handler
1516 * receives this value it makes sense to use it.
1518 * If your interrupt is shared you must pass a non NULL dev_id
1519 * as this is required when freeing the interrupt.
1523 * IRQF_SHARED Interrupt is shared
1524 * IRQF_TRIGGER_* Specify active edge(s) or level
1527 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1528 irq_handler_t thread_fn, unsigned long irqflags,
1529 const char *devname, void *dev_id)
1531 struct irqaction *action;
1532 struct irq_desc *desc;
1536 * Sanity-check: shared interrupts must pass in a real dev-ID,
1537 * otherwise we'll have trouble later trying to figure out
1538 * which interrupt is which (messes up the interrupt freeing
1541 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1542 * it cannot be set along with IRQF_NO_SUSPEND.
1544 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1545 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1546 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1549 desc = irq_to_desc(irq);
1553 if (!irq_settings_can_request(desc) ||
1554 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1560 handler = irq_default_primary_handler;
1563 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1567 action->handler = handler;
1568 action->thread_fn = thread_fn;
1569 action->flags = irqflags;
1570 action->name = devname;
1571 action->dev_id = dev_id;
1573 chip_bus_lock(desc);
1574 retval = __setup_irq(irq, desc, action);
1575 chip_bus_sync_unlock(desc);
1580 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1581 if (!retval && (irqflags & IRQF_SHARED)) {
1583 * It's a shared IRQ -- the driver ought to be prepared for it
1584 * to happen immediately, so let's make sure....
1585 * We disable the irq to make sure that a 'real' IRQ doesn't
1586 * run in parallel with our fake.
1588 unsigned long flags;
1591 local_irq_save(flags);
1593 handler(irq, dev_id);
1595 local_irq_restore(flags);
1601 EXPORT_SYMBOL(request_threaded_irq);
1604 * request_any_context_irq - allocate an interrupt line
1605 * @irq: Interrupt line to allocate
1606 * @handler: Function to be called when the IRQ occurs.
1607 * Threaded handler for threaded interrupts.
1608 * @flags: Interrupt type flags
1609 * @name: An ascii name for the claiming device
1610 * @dev_id: A cookie passed back to the handler function
1612 * This call allocates interrupt resources and enables the
1613 * interrupt line and IRQ handling. It selects either a
1614 * hardirq or threaded handling method depending on the
1617 * On failure, it returns a negative value. On success,
1618 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1620 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1621 unsigned long flags, const char *name, void *dev_id)
1623 struct irq_desc *desc = irq_to_desc(irq);
1629 if (irq_settings_is_nested_thread(desc)) {
1630 ret = request_threaded_irq(irq, NULL, handler,
1631 flags, name, dev_id);
1632 return !ret ? IRQC_IS_NESTED : ret;
1635 ret = request_irq(irq, handler, flags, name, dev_id);
1636 return !ret ? IRQC_IS_HARDIRQ : ret;
1638 EXPORT_SYMBOL_GPL(request_any_context_irq);
1640 void enable_percpu_irq(unsigned int irq, unsigned int type)
1642 unsigned int cpu = smp_processor_id();
1643 unsigned long flags;
1644 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1649 type &= IRQ_TYPE_SENSE_MASK;
1650 if (type != IRQ_TYPE_NONE) {
1653 ret = __irq_set_trigger(desc, irq, type);
1656 WARN(1, "failed to set type for IRQ%d\n", irq);
1661 irq_percpu_enable(desc, cpu);
1663 irq_put_desc_unlock(desc, flags);
1665 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1667 void disable_percpu_irq(unsigned int irq)
1669 unsigned int cpu = smp_processor_id();
1670 unsigned long flags;
1671 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1676 irq_percpu_disable(desc, cpu);
1677 irq_put_desc_unlock(desc, flags);
1679 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1682 * Internal function to unregister a percpu irqaction.
1684 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1686 struct irq_desc *desc = irq_to_desc(irq);
1687 struct irqaction *action;
1688 unsigned long flags;
1690 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1695 raw_spin_lock_irqsave(&desc->lock, flags);
1697 action = desc->action;
1698 if (!action || action->percpu_dev_id != dev_id) {
1699 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1703 if (!cpumask_empty(desc->percpu_enabled)) {
1704 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1705 irq, cpumask_first(desc->percpu_enabled));
1709 /* Found it - now remove it from the list of entries: */
1710 desc->action = NULL;
1712 raw_spin_unlock_irqrestore(&desc->lock, flags);
1714 unregister_handler_proc(irq, action);
1716 module_put(desc->owner);
1720 raw_spin_unlock_irqrestore(&desc->lock, flags);
1725 * remove_percpu_irq - free a per-cpu interrupt
1726 * @irq: Interrupt line to free
1727 * @act: irqaction for the interrupt
1729 * Used to remove interrupts statically setup by the early boot process.
1731 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1733 struct irq_desc *desc = irq_to_desc(irq);
1735 if (desc && irq_settings_is_per_cpu_devid(desc))
1736 __free_percpu_irq(irq, act->percpu_dev_id);
1740 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1741 * @irq: Interrupt line to free
1742 * @dev_id: Device identity to free
1744 * Remove a percpu interrupt handler. The handler is removed, but
1745 * the interrupt line is not disabled. This must be done on each
1746 * CPU before calling this function. The function does not return
1747 * until any executing interrupts for this IRQ have completed.
1749 * This function must not be called from interrupt context.
1751 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1753 struct irq_desc *desc = irq_to_desc(irq);
1755 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1758 chip_bus_lock(desc);
1759 kfree(__free_percpu_irq(irq, dev_id));
1760 chip_bus_sync_unlock(desc);
1764 * setup_percpu_irq - setup a per-cpu interrupt
1765 * @irq: Interrupt line to setup
1766 * @act: irqaction for the interrupt
1768 * Used to statically setup per-cpu interrupts in the early boot process.
1770 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1772 struct irq_desc *desc = irq_to_desc(irq);
1775 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1777 chip_bus_lock(desc);
1778 retval = __setup_irq(irq, desc, act);
1779 chip_bus_sync_unlock(desc);
1785 * request_percpu_irq - allocate a percpu interrupt line
1786 * @irq: Interrupt line to allocate
1787 * @handler: Function to be called when the IRQ occurs.
1788 * @devname: An ascii name for the claiming device
1789 * @dev_id: A percpu cookie passed back to the handler function
1791 * This call allocates interrupt resources, but doesn't
1792 * automatically enable the interrupt. It has to be done on each
1793 * CPU using enable_percpu_irq().
1795 * Dev_id must be globally unique. It is a per-cpu variable, and
1796 * the handler gets called with the interrupted CPU's instance of
1799 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1800 const char *devname, void __percpu *dev_id)
1802 struct irqaction *action;
1803 struct irq_desc *desc;
1809 desc = irq_to_desc(irq);
1810 if (!desc || !irq_settings_can_request(desc) ||
1811 !irq_settings_is_per_cpu_devid(desc))
1814 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1818 action->handler = handler;
1819 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1820 action->name = devname;
1821 action->percpu_dev_id = dev_id;
1823 chip_bus_lock(desc);
1824 retval = __setup_irq(irq, desc, action);
1825 chip_bus_sync_unlock(desc);
1834 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
1835 * @irq: Interrupt line that is forwarded to a VM
1836 * @which: One of IRQCHIP_STATE_* the caller wants to know about
1837 * @state: a pointer to a boolean where the state is to be storeed
1839 * This call snapshots the internal irqchip state of an
1840 * interrupt, returning into @state the bit corresponding to
1843 * This function should be called with preemption disabled if the
1844 * interrupt controller has per-cpu registers.
1846 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
1849 struct irq_desc *desc;
1850 struct irq_data *data;
1851 struct irq_chip *chip;
1852 unsigned long flags;
1855 desc = irq_get_desc_buslock(irq, &flags, 0);
1859 data = irq_desc_get_irq_data(desc);
1862 chip = irq_data_get_irq_chip(data);
1863 if (chip->irq_get_irqchip_state)
1865 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1866 data = data->parent_data;
1873 err = chip->irq_get_irqchip_state(data, which, state);
1875 irq_put_desc_busunlock(desc, flags);
1880 * irq_set_irqchip_state - set the state of a forwarded interrupt.
1881 * @irq: Interrupt line that is forwarded to a VM
1882 * @which: State to be restored (one of IRQCHIP_STATE_*)
1883 * @val: Value corresponding to @which
1885 * This call sets the internal irqchip state of an interrupt,
1886 * depending on the value of @which.
1888 * This function should be called with preemption disabled if the
1889 * interrupt controller has per-cpu registers.
1891 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
1894 struct irq_desc *desc;
1895 struct irq_data *data;
1896 struct irq_chip *chip;
1897 unsigned long flags;
1900 desc = irq_get_desc_buslock(irq, &flags, 0);
1904 data = irq_desc_get_irq_data(desc);
1907 chip = irq_data_get_irq_chip(data);
1908 if (chip->irq_set_irqchip_state)
1910 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1911 data = data->parent_data;
1918 err = chip->irq_set_irqchip_state(data, which, val);
1920 irq_put_desc_busunlock(desc, flags);