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;
118 static int __irq_can_set_affinity(struct irq_desc *desc)
120 if (!desc || !irqd_can_balance(&desc->irq_data) ||
121 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
127 * irq_can_set_affinity - Check if the affinity of a given irq can be set
128 * @irq: Interrupt to check
131 int irq_can_set_affinity(unsigned int irq)
133 return __irq_can_set_affinity(irq_to_desc(irq));
137 * irq_set_thread_affinity - Notify irq threads to adjust affinity
138 * @desc: irq descriptor which has affitnity changed
140 * We just set IRQTF_AFFINITY and delegate the affinity setting
141 * to the interrupt thread itself. We can not call
142 * set_cpus_allowed_ptr() here as we hold desc->lock and this
143 * code can be called from hard interrupt context.
145 void irq_set_thread_affinity(struct irq_desc *desc)
147 struct irqaction *action = desc->action;
151 set_bit(IRQTF_AFFINITY, &action->thread_flags);
152 action = action->next;
156 #ifdef CONFIG_GENERIC_PENDING_IRQ
157 static inline bool irq_can_move_pcntxt(struct irq_data *data)
159 return irqd_can_move_in_process_context(data);
161 static inline bool irq_move_pending(struct irq_data *data)
163 return irqd_is_setaffinity_pending(data);
166 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
168 cpumask_copy(desc->pending_mask, mask);
171 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
173 cpumask_copy(mask, desc->pending_mask);
176 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
177 static inline bool irq_move_pending(struct irq_data *data) { return false; }
179 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
181 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
184 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
187 struct irq_desc *desc = irq_data_to_desc(data);
188 struct irq_chip *chip = irq_data_get_irq_chip(data);
191 ret = chip->irq_set_affinity(data, mask, force);
193 case IRQ_SET_MASK_OK:
194 case IRQ_SET_MASK_OK_DONE:
195 cpumask_copy(desc->irq_common_data.affinity, mask);
196 case IRQ_SET_MASK_OK_NOCOPY:
197 irq_set_thread_affinity(desc);
204 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
207 struct irq_chip *chip = irq_data_get_irq_chip(data);
208 struct irq_desc *desc = irq_data_to_desc(data);
211 if (!chip || !chip->irq_set_affinity)
214 if (irq_can_move_pcntxt(data)) {
215 ret = irq_do_set_affinity(data, mask, force);
217 irqd_set_move_pending(data);
218 irq_copy_pending(desc, mask);
221 if (desc->affinity_notify) {
222 kref_get(&desc->affinity_notify->kref);
223 schedule_work(&desc->affinity_notify->work);
225 irqd_set(data, IRQD_AFFINITY_SET);
230 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
232 struct irq_desc *desc = irq_to_desc(irq);
239 raw_spin_lock_irqsave(&desc->lock, flags);
240 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
241 raw_spin_unlock_irqrestore(&desc->lock, flags);
245 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
248 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
252 desc->affinity_hint = m;
253 irq_put_desc_unlock(desc, flags);
254 /* set the initial affinity to prevent every interrupt being on CPU0 */
256 __irq_set_affinity(irq, m, false);
259 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
261 static void irq_affinity_notify(struct work_struct *work)
263 struct irq_affinity_notify *notify =
264 container_of(work, struct irq_affinity_notify, work);
265 struct irq_desc *desc = irq_to_desc(notify->irq);
266 cpumask_var_t cpumask;
269 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
272 raw_spin_lock_irqsave(&desc->lock, flags);
273 if (irq_move_pending(&desc->irq_data))
274 irq_get_pending(cpumask, desc);
276 cpumask_copy(cpumask, desc->irq_common_data.affinity);
277 raw_spin_unlock_irqrestore(&desc->lock, flags);
279 notify->notify(notify, cpumask);
281 free_cpumask_var(cpumask);
283 kref_put(¬ify->kref, notify->release);
287 * irq_set_affinity_notifier - control notification of IRQ affinity changes
288 * @irq: Interrupt for which to enable/disable notification
289 * @notify: Context for notification, or %NULL to disable
290 * notification. Function pointers must be initialised;
291 * the other fields will be initialised by this function.
293 * Must be called in process context. Notification may only be enabled
294 * after the IRQ is allocated and must be disabled before the IRQ is
295 * freed using free_irq().
298 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
300 struct irq_desc *desc = irq_to_desc(irq);
301 struct irq_affinity_notify *old_notify;
304 /* The release function is promised process context */
310 /* Complete initialisation of *notify */
313 kref_init(¬ify->kref);
314 INIT_WORK(¬ify->work, irq_affinity_notify);
317 raw_spin_lock_irqsave(&desc->lock, flags);
318 old_notify = desc->affinity_notify;
319 desc->affinity_notify = notify;
320 raw_spin_unlock_irqrestore(&desc->lock, flags);
323 kref_put(&old_notify->kref, old_notify->release);
327 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
329 #ifndef CONFIG_AUTO_IRQ_AFFINITY
331 * Generic version of the affinity autoselector.
333 static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
335 struct cpumask *set = irq_default_affinity;
336 int node = irq_desc_get_node(desc);
338 /* Excludes PER_CPU and NO_BALANCE interrupts */
339 if (!__irq_can_set_affinity(desc))
343 * Preserve an userspace affinity setup, but make sure that
344 * one of the targets is online.
346 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
347 if (cpumask_intersects(desc->irq_common_data.affinity,
349 set = desc->irq_common_data.affinity;
351 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
354 cpumask_and(mask, cpu_online_mask, set);
355 if (node != NUMA_NO_NODE) {
356 const struct cpumask *nodemask = cpumask_of_node(node);
358 /* make sure at least one of the cpus in nodemask is online */
359 if (cpumask_intersects(mask, nodemask))
360 cpumask_and(mask, mask, nodemask);
362 irq_do_set_affinity(&desc->irq_data, mask, false);
366 /* Wrapper for ALPHA specific affinity selector magic */
367 static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
369 return irq_select_affinity(irq_desc_get_irq(d));
374 * Called when affinity is set via /proc/irq
376 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
378 struct irq_desc *desc = irq_to_desc(irq);
382 raw_spin_lock_irqsave(&desc->lock, flags);
383 ret = setup_affinity(desc, mask);
384 raw_spin_unlock_irqrestore(&desc->lock, flags);
390 setup_affinity(struct irq_desc *desc, struct cpumask *mask)
397 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
398 * @irq: interrupt number to set affinity
399 * @vcpu_info: vCPU specific data
401 * This function uses the vCPU specific data to set the vCPU
402 * affinity for an irq. The vCPU specific data is passed from
403 * outside, such as KVM. One example code path is as below:
404 * KVM -> IOMMU -> irq_set_vcpu_affinity().
406 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
409 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
410 struct irq_data *data;
411 struct irq_chip *chip;
417 data = irq_desc_get_irq_data(desc);
418 chip = irq_data_get_irq_chip(data);
419 if (chip && chip->irq_set_vcpu_affinity)
420 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
421 irq_put_desc_unlock(desc, flags);
425 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
427 void __disable_irq(struct irq_desc *desc)
433 static int __disable_irq_nosync(unsigned int irq)
436 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
441 irq_put_desc_busunlock(desc, flags);
446 * disable_irq_nosync - disable an irq without waiting
447 * @irq: Interrupt to disable
449 * Disable the selected interrupt line. Disables and Enables are
451 * Unlike disable_irq(), this function does not ensure existing
452 * instances of the IRQ handler have completed before returning.
454 * This function may be called from IRQ context.
456 void disable_irq_nosync(unsigned int irq)
458 __disable_irq_nosync(irq);
460 EXPORT_SYMBOL(disable_irq_nosync);
463 * disable_irq - disable an irq and wait for completion
464 * @irq: Interrupt to disable
466 * Disable the selected interrupt line. Enables and Disables are
468 * This function waits for any pending IRQ handlers for this interrupt
469 * to complete before returning. If you use this function while
470 * holding a resource the IRQ handler may need you will deadlock.
472 * This function may be called - with care - from IRQ context.
474 void disable_irq(unsigned int irq)
476 if (!__disable_irq_nosync(irq))
477 synchronize_irq(irq);
479 EXPORT_SYMBOL(disable_irq);
482 * disable_hardirq - disables an irq and waits for hardirq completion
483 * @irq: Interrupt to disable
485 * Disable the selected interrupt line. Enables and Disables are
487 * This function waits for any pending hard IRQ handlers for this
488 * interrupt to complete before returning. If you use this function while
489 * holding a resource the hard IRQ handler may need you will deadlock.
491 * When used to optimistically disable an interrupt from atomic context
492 * the return value must be checked.
494 * Returns: false if a threaded handler is active.
496 * This function may be called - with care - from IRQ context.
498 bool disable_hardirq(unsigned int irq)
500 if (!__disable_irq_nosync(irq))
501 return synchronize_hardirq(irq);
505 EXPORT_SYMBOL_GPL(disable_hardirq);
507 void __enable_irq(struct irq_desc *desc)
509 switch (desc->depth) {
512 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
513 irq_desc_get_irq(desc));
516 if (desc->istate & IRQS_SUSPENDED)
518 /* Prevent probing on this irq: */
519 irq_settings_set_noprobe(desc);
521 check_irq_resend(desc);
530 * enable_irq - enable handling of an irq
531 * @irq: Interrupt to enable
533 * Undoes the effect of one call to disable_irq(). If this
534 * matches the last disable, processing of interrupts on this
535 * IRQ line is re-enabled.
537 * This function may be called from IRQ context only when
538 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
540 void enable_irq(unsigned int irq)
543 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
547 if (WARN(!desc->irq_data.chip,
548 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
553 irq_put_desc_busunlock(desc, flags);
555 EXPORT_SYMBOL(enable_irq);
557 static int set_irq_wake_real(unsigned int irq, unsigned int on)
559 struct irq_desc *desc = irq_to_desc(irq);
562 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
565 if (desc->irq_data.chip->irq_set_wake)
566 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
572 * irq_set_irq_wake - control irq power management wakeup
573 * @irq: interrupt to control
574 * @on: enable/disable power management wakeup
576 * Enable/disable power management wakeup mode, which is
577 * disabled by default. Enables and disables must match,
578 * just as they match for non-wakeup mode support.
580 * Wakeup mode lets this IRQ wake the system from sleep
581 * states like "suspend to RAM".
583 int irq_set_irq_wake(unsigned int irq, unsigned int on)
586 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
592 /* wakeup-capable irqs can be shared between drivers that
593 * don't need to have the same sleep mode behaviors.
596 if (desc->wake_depth++ == 0) {
597 ret = set_irq_wake_real(irq, on);
599 desc->wake_depth = 0;
601 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
604 if (desc->wake_depth == 0) {
605 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
606 } else if (--desc->wake_depth == 0) {
607 ret = set_irq_wake_real(irq, on);
609 desc->wake_depth = 1;
611 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
614 irq_put_desc_busunlock(desc, flags);
617 EXPORT_SYMBOL(irq_set_irq_wake);
620 * Internal function that tells the architecture code whether a
621 * particular irq has been exclusively allocated or is available
624 int can_request_irq(unsigned int irq, unsigned long irqflags)
627 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
633 if (irq_settings_can_request(desc)) {
635 irqflags & desc->action->flags & IRQF_SHARED)
638 irq_put_desc_unlock(desc, flags);
642 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
644 struct irq_chip *chip = desc->irq_data.chip;
647 if (!chip || !chip->irq_set_type) {
649 * IRQF_TRIGGER_* but the PIC does not support multiple
652 pr_debug("No set_type function for IRQ %d (%s)\n",
653 irq_desc_get_irq(desc),
654 chip ? (chip->name ? : "unknown") : "unknown");
658 flags &= IRQ_TYPE_SENSE_MASK;
660 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
661 if (!irqd_irq_masked(&desc->irq_data))
663 if (!irqd_irq_disabled(&desc->irq_data))
667 /* caller masked out all except trigger mode flags */
668 ret = chip->irq_set_type(&desc->irq_data, flags);
671 case IRQ_SET_MASK_OK:
672 case IRQ_SET_MASK_OK_DONE:
673 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
674 irqd_set(&desc->irq_data, flags);
676 case IRQ_SET_MASK_OK_NOCOPY:
677 flags = irqd_get_trigger_type(&desc->irq_data);
678 irq_settings_set_trigger_mask(desc, flags);
679 irqd_clear(&desc->irq_data, IRQD_LEVEL);
680 irq_settings_clr_level(desc);
681 if (flags & IRQ_TYPE_LEVEL_MASK) {
682 irq_settings_set_level(desc);
683 irqd_set(&desc->irq_data, IRQD_LEVEL);
689 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
690 flags, irq_desc_get_irq(desc), chip->irq_set_type);
697 #ifdef CONFIG_HARDIRQS_SW_RESEND
698 int irq_set_parent(int irq, int parent_irq)
701 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
706 desc->parent_irq = parent_irq;
708 irq_put_desc_unlock(desc, flags);
714 * Default primary interrupt handler for threaded interrupts. Is
715 * assigned as primary handler when request_threaded_irq is called
716 * with handler == NULL. Useful for oneshot interrupts.
718 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
720 return IRQ_WAKE_THREAD;
724 * Primary handler for nested threaded interrupts. Should never be
727 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
729 WARN(1, "Primary handler called for nested irq %d\n", irq);
733 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
735 WARN(1, "Secondary action handler called for irq %d\n", irq);
739 static int irq_wait_for_interrupt(struct irqaction *action)
741 set_current_state(TASK_INTERRUPTIBLE);
743 while (!kthread_should_stop()) {
745 if (test_and_clear_bit(IRQTF_RUNTHREAD,
746 &action->thread_flags)) {
747 __set_current_state(TASK_RUNNING);
751 set_current_state(TASK_INTERRUPTIBLE);
753 __set_current_state(TASK_RUNNING);
758 * Oneshot interrupts keep the irq line masked until the threaded
759 * handler finished. unmask if the interrupt has not been disabled and
762 static void irq_finalize_oneshot(struct irq_desc *desc,
763 struct irqaction *action)
765 if (!(desc->istate & IRQS_ONESHOT) ||
766 action->handler == irq_forced_secondary_handler)
770 raw_spin_lock_irq(&desc->lock);
773 * Implausible though it may be we need to protect us against
774 * the following scenario:
776 * The thread is faster done than the hard interrupt handler
777 * on the other CPU. If we unmask the irq line then the
778 * interrupt can come in again and masks the line, leaves due
779 * to IRQS_INPROGRESS and the irq line is masked forever.
781 * This also serializes the state of shared oneshot handlers
782 * versus "desc->threads_onehsot |= action->thread_mask;" in
783 * irq_wake_thread(). See the comment there which explains the
786 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
787 raw_spin_unlock_irq(&desc->lock);
788 chip_bus_sync_unlock(desc);
794 * Now check again, whether the thread should run. Otherwise
795 * we would clear the threads_oneshot bit of this thread which
798 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
801 desc->threads_oneshot &= ~action->thread_mask;
803 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
804 irqd_irq_masked(&desc->irq_data))
805 unmask_threaded_irq(desc);
808 raw_spin_unlock_irq(&desc->lock);
809 chip_bus_sync_unlock(desc);
814 * Check whether we need to change the affinity of the interrupt thread.
817 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
822 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
826 * In case we are out of memory we set IRQTF_AFFINITY again and
827 * try again next time
829 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
830 set_bit(IRQTF_AFFINITY, &action->thread_flags);
834 raw_spin_lock_irq(&desc->lock);
836 * This code is triggered unconditionally. Check the affinity
837 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
839 if (desc->irq_common_data.affinity)
840 cpumask_copy(mask, desc->irq_common_data.affinity);
843 raw_spin_unlock_irq(&desc->lock);
846 set_cpus_allowed_ptr(current, mask);
847 free_cpumask_var(mask);
851 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
855 * Interrupts which are not explicitely requested as threaded
856 * interrupts rely on the implicit bh/preempt disable of the hard irq
857 * context. So we need to disable bh here to avoid deadlocks and other
861 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
866 ret = action->thread_fn(action->irq, action->dev_id);
867 irq_finalize_oneshot(desc, action);
873 * Interrupts explicitly requested as threaded interrupts want to be
874 * preemtible - many of them need to sleep and wait for slow busses to
877 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
878 struct irqaction *action)
882 ret = action->thread_fn(action->irq, action->dev_id);
883 irq_finalize_oneshot(desc, action);
887 static void wake_threads_waitq(struct irq_desc *desc)
889 if (atomic_dec_and_test(&desc->threads_active))
890 wake_up(&desc->wait_for_threads);
893 static void irq_thread_dtor(struct callback_head *unused)
895 struct task_struct *tsk = current;
896 struct irq_desc *desc;
897 struct irqaction *action;
899 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
902 action = kthread_data(tsk);
904 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
905 tsk->comm, tsk->pid, action->irq);
908 desc = irq_to_desc(action->irq);
910 * If IRQTF_RUNTHREAD is set, we need to decrement
911 * desc->threads_active and wake possible waiters.
913 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
914 wake_threads_waitq(desc);
916 /* Prevent a stale desc->threads_oneshot */
917 irq_finalize_oneshot(desc, action);
920 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
922 struct irqaction *secondary = action->secondary;
924 if (WARN_ON_ONCE(!secondary))
927 raw_spin_lock_irq(&desc->lock);
928 __irq_wake_thread(desc, secondary);
929 raw_spin_unlock_irq(&desc->lock);
933 * Interrupt handler thread
935 static int irq_thread(void *data)
937 struct callback_head on_exit_work;
938 struct irqaction *action = data;
939 struct irq_desc *desc = irq_to_desc(action->irq);
940 irqreturn_t (*handler_fn)(struct irq_desc *desc,
941 struct irqaction *action);
943 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
944 &action->thread_flags))
945 handler_fn = irq_forced_thread_fn;
947 handler_fn = irq_thread_fn;
949 init_task_work(&on_exit_work, irq_thread_dtor);
950 task_work_add(current, &on_exit_work, false);
952 irq_thread_check_affinity(desc, action);
954 while (!irq_wait_for_interrupt(action)) {
955 irqreturn_t action_ret;
957 irq_thread_check_affinity(desc, action);
959 action_ret = handler_fn(desc, action);
960 if (action_ret == IRQ_HANDLED)
961 atomic_inc(&desc->threads_handled);
962 if (action_ret == IRQ_WAKE_THREAD)
963 irq_wake_secondary(desc, action);
965 wake_threads_waitq(desc);
969 * This is the regular exit path. __free_irq() is stopping the
970 * thread via kthread_stop() after calling
971 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
972 * oneshot mask bit can be set. We cannot verify that as we
973 * cannot touch the oneshot mask at this point anymore as
974 * __setup_irq() might have given out currents thread_mask
977 task_work_cancel(current, irq_thread_dtor);
982 * irq_wake_thread - wake the irq thread for the action identified by dev_id
983 * @irq: Interrupt line
984 * @dev_id: Device identity for which the thread should be woken
987 void irq_wake_thread(unsigned int irq, void *dev_id)
989 struct irq_desc *desc = irq_to_desc(irq);
990 struct irqaction *action;
993 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
996 raw_spin_lock_irqsave(&desc->lock, flags);
997 for (action = desc->action; action; action = action->next) {
998 if (action->dev_id == dev_id) {
1000 __irq_wake_thread(desc, action);
1004 raw_spin_unlock_irqrestore(&desc->lock, flags);
1006 EXPORT_SYMBOL_GPL(irq_wake_thread);
1008 static int irq_setup_forced_threading(struct irqaction *new)
1010 if (!force_irqthreads)
1012 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1015 new->flags |= IRQF_ONESHOT;
1018 * Handle the case where we have a real primary handler and a
1019 * thread handler. We force thread them as well by creating a
1022 if (new->handler != irq_default_primary_handler && new->thread_fn) {
1023 /* Allocate the secondary action */
1024 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1025 if (!new->secondary)
1027 new->secondary->handler = irq_forced_secondary_handler;
1028 new->secondary->thread_fn = new->thread_fn;
1029 new->secondary->dev_id = new->dev_id;
1030 new->secondary->irq = new->irq;
1031 new->secondary->name = new->name;
1033 /* Deal with the primary handler */
1034 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1035 new->thread_fn = new->handler;
1036 new->handler = irq_default_primary_handler;
1040 static int irq_request_resources(struct irq_desc *desc)
1042 struct irq_data *d = &desc->irq_data;
1043 struct irq_chip *c = d->chip;
1045 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1048 static void irq_release_resources(struct irq_desc *desc)
1050 struct irq_data *d = &desc->irq_data;
1051 struct irq_chip *c = d->chip;
1053 if (c->irq_release_resources)
1054 c->irq_release_resources(d);
1058 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1060 struct task_struct *t;
1061 struct sched_param param = {
1062 .sched_priority = MAX_USER_RT_PRIO/2,
1066 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1069 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1071 param.sched_priority -= 1;
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);
1100 * Internal function to register an irqaction - typically used to
1101 * allocate special interrupts that are part of the architecture.
1104 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1106 struct irqaction *old, **old_ptr;
1107 unsigned long flags, thread_mask = 0;
1108 int ret, nested, shared = 0;
1114 if (desc->irq_data.chip == &no_irq_chip)
1116 if (!try_module_get(desc->owner))
1122 * Check whether the interrupt nests into another interrupt
1125 nested = irq_settings_is_nested_thread(desc);
1127 if (!new->thread_fn) {
1132 * Replace the primary handler which was provided from
1133 * the driver for non nested interrupt handling by the
1134 * dummy function which warns when called.
1136 new->handler = irq_nested_primary_handler;
1138 if (irq_settings_can_thread(desc)) {
1139 ret = irq_setup_forced_threading(new);
1146 * Create a handler thread when a thread function is supplied
1147 * and the interrupt does not nest into another interrupt
1150 if (new->thread_fn && !nested) {
1151 ret = setup_irq_thread(new, irq, false);
1154 if (new->secondary) {
1155 ret = setup_irq_thread(new->secondary, irq, true);
1161 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1167 * Drivers are often written to work w/o knowledge about the
1168 * underlying irq chip implementation, so a request for a
1169 * threaded irq without a primary hard irq context handler
1170 * requires the ONESHOT flag to be set. Some irq chips like
1171 * MSI based interrupts are per se one shot safe. Check the
1172 * chip flags, so we can avoid the unmask dance at the end of
1173 * the threaded handler for those.
1175 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1176 new->flags &= ~IRQF_ONESHOT;
1179 * The following block of code has to be executed atomically
1181 raw_spin_lock_irqsave(&desc->lock, flags);
1182 old_ptr = &desc->action;
1186 * Can't share interrupts unless both agree to and are
1187 * the same type (level, edge, polarity). So both flag
1188 * fields must have IRQF_SHARED set and the bits which
1189 * set the trigger type must match. Also all must
1192 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1193 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1194 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1197 /* All handlers must agree on per-cpuness */
1198 if ((old->flags & IRQF_PERCPU) !=
1199 (new->flags & IRQF_PERCPU))
1202 /* add new interrupt at end of irq queue */
1205 * Or all existing action->thread_mask bits,
1206 * so we can find the next zero bit for this
1209 thread_mask |= old->thread_mask;
1210 old_ptr = &old->next;
1217 * Setup the thread mask for this irqaction for ONESHOT. For
1218 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1219 * conditional in irq_wake_thread().
1221 if (new->flags & IRQF_ONESHOT) {
1223 * Unlikely to have 32 resp 64 irqs sharing one line,
1226 if (thread_mask == ~0UL) {
1231 * The thread_mask for the action is or'ed to
1232 * desc->thread_active to indicate that the
1233 * IRQF_ONESHOT thread handler has been woken, but not
1234 * yet finished. The bit is cleared when a thread
1235 * completes. When all threads of a shared interrupt
1236 * line have completed desc->threads_active becomes
1237 * zero and the interrupt line is unmasked. See
1238 * handle.c:irq_wake_thread() for further information.
1240 * If no thread is woken by primary (hard irq context)
1241 * interrupt handlers, then desc->threads_active is
1242 * also checked for zero to unmask the irq line in the
1243 * affected hard irq flow handlers
1244 * (handle_[fasteoi|level]_irq).
1246 * The new action gets the first zero bit of
1247 * thread_mask assigned. See the loop above which or's
1248 * all existing action->thread_mask bits.
1250 new->thread_mask = 1 << ffz(thread_mask);
1252 } else if (new->handler == irq_default_primary_handler &&
1253 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1255 * The interrupt was requested with handler = NULL, so
1256 * we use the default primary handler for it. But it
1257 * does not have the oneshot flag set. In combination
1258 * with level interrupts this is deadly, because the
1259 * default primary handler just wakes the thread, then
1260 * the irq lines is reenabled, but the device still
1261 * has the level irq asserted. Rinse and repeat....
1263 * While this works for edge type interrupts, we play
1264 * it safe and reject unconditionally because we can't
1265 * say for sure which type this interrupt really
1266 * has. The type flags are unreliable as the
1267 * underlying chip implementation can override them.
1269 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1276 ret = irq_request_resources(desc);
1278 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1279 new->name, irq, desc->irq_data.chip->name);
1283 init_waitqueue_head(&desc->wait_for_threads);
1285 /* Setup the type (level, edge polarity) if configured: */
1286 if (new->flags & IRQF_TRIGGER_MASK) {
1287 ret = __irq_set_trigger(desc,
1288 new->flags & IRQF_TRIGGER_MASK);
1294 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1295 IRQS_ONESHOT | IRQS_WAITING);
1296 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1298 if (new->flags & IRQF_PERCPU) {
1299 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1300 irq_settings_set_per_cpu(desc);
1303 if (new->flags & IRQF_ONESHOT)
1304 desc->istate |= IRQS_ONESHOT;
1306 if (irq_settings_can_autoenable(desc))
1307 irq_startup(desc, true);
1309 /* Undo nested disables: */
1312 /* Exclude IRQ from balancing if requested */
1313 if (new->flags & IRQF_NOBALANCING) {
1314 irq_settings_set_no_balancing(desc);
1315 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1318 /* Set default affinity mask once everything is setup */
1319 setup_affinity(desc, mask);
1321 } else if (new->flags & IRQF_TRIGGER_MASK) {
1322 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1323 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1326 /* hope the handler works with current trigger mode */
1327 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1333 irq_pm_install_action(desc, new);
1335 /* Reset broken irq detection when installing new handler */
1336 desc->irq_count = 0;
1337 desc->irqs_unhandled = 0;
1340 * Check whether we disabled the irq via the spurious handler
1341 * before. Reenable it and give it another chance.
1343 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1344 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1348 raw_spin_unlock_irqrestore(&desc->lock, flags);
1351 * Strictly no need to wake it up, but hung_task complains
1352 * when no hard interrupt wakes the thread up.
1355 wake_up_process(new->thread);
1357 wake_up_process(new->secondary->thread);
1359 register_irq_proc(irq, desc);
1361 register_handler_proc(irq, new);
1362 free_cpumask_var(mask);
1367 if (!(new->flags & IRQF_PROBE_SHARED)) {
1368 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1369 irq, new->flags, new->name, old->flags, old->name);
1370 #ifdef CONFIG_DEBUG_SHIRQ
1377 raw_spin_unlock_irqrestore(&desc->lock, flags);
1378 free_cpumask_var(mask);
1382 struct task_struct *t = new->thread;
1388 if (new->secondary && new->secondary->thread) {
1389 struct task_struct *t = new->secondary->thread;
1391 new->secondary->thread = NULL;
1396 module_put(desc->owner);
1401 * setup_irq - setup an interrupt
1402 * @irq: Interrupt line to setup
1403 * @act: irqaction for the interrupt
1405 * Used to statically setup interrupts in the early boot process.
1407 int setup_irq(unsigned int irq, struct irqaction *act)
1410 struct irq_desc *desc = irq_to_desc(irq);
1412 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1414 chip_bus_lock(desc);
1415 retval = __setup_irq(irq, desc, act);
1416 chip_bus_sync_unlock(desc);
1420 EXPORT_SYMBOL_GPL(setup_irq);
1423 * Internal function to unregister an irqaction - used to free
1424 * regular and special interrupts that are part of the architecture.
1426 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1428 struct irq_desc *desc = irq_to_desc(irq);
1429 struct irqaction *action, **action_ptr;
1430 unsigned long flags;
1432 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1437 chip_bus_lock(desc);
1438 raw_spin_lock_irqsave(&desc->lock, flags);
1441 * There can be multiple actions per IRQ descriptor, find the right
1442 * one based on the dev_id:
1444 action_ptr = &desc->action;
1446 action = *action_ptr;
1449 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1450 raw_spin_unlock_irqrestore(&desc->lock, flags);
1451 chip_bus_sync_unlock(desc);
1455 if (action->dev_id == dev_id)
1457 action_ptr = &action->next;
1460 /* Found it - now remove it from the list of entries: */
1461 *action_ptr = action->next;
1463 irq_pm_remove_action(desc, action);
1465 /* If this was the last handler, shut down the IRQ line: */
1466 if (!desc->action) {
1467 irq_settings_clr_disable_unlazy(desc);
1469 irq_release_resources(desc);
1473 /* make sure affinity_hint is cleaned up */
1474 if (WARN_ON_ONCE(desc->affinity_hint))
1475 desc->affinity_hint = NULL;
1478 raw_spin_unlock_irqrestore(&desc->lock, flags);
1479 chip_bus_sync_unlock(desc);
1481 unregister_handler_proc(irq, action);
1483 /* Make sure it's not being used on another CPU: */
1484 synchronize_irq(irq);
1486 #ifdef CONFIG_DEBUG_SHIRQ
1488 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1489 * event to happen even now it's being freed, so let's make sure that
1490 * is so by doing an extra call to the handler ....
1492 * ( We do this after actually deregistering it, to make sure that a
1493 * 'real' IRQ doesn't run in * parallel with our fake. )
1495 if (action->flags & IRQF_SHARED) {
1496 local_irq_save(flags);
1497 action->handler(irq, dev_id);
1498 local_irq_restore(flags);
1502 if (action->thread) {
1503 kthread_stop(action->thread);
1504 put_task_struct(action->thread);
1505 if (action->secondary && action->secondary->thread) {
1506 kthread_stop(action->secondary->thread);
1507 put_task_struct(action->secondary->thread);
1511 module_put(desc->owner);
1512 kfree(action->secondary);
1517 * remove_irq - free an interrupt
1518 * @irq: Interrupt line to free
1519 * @act: irqaction for the interrupt
1521 * Used to remove interrupts statically setup by the early boot process.
1523 void remove_irq(unsigned int irq, struct irqaction *act)
1525 struct irq_desc *desc = irq_to_desc(irq);
1527 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1528 __free_irq(irq, act->dev_id);
1530 EXPORT_SYMBOL_GPL(remove_irq);
1533 * free_irq - free an interrupt allocated with request_irq
1534 * @irq: Interrupt line to free
1535 * @dev_id: Device identity to free
1537 * Remove an interrupt handler. The handler is removed and if the
1538 * interrupt line is no longer in use by any driver it is disabled.
1539 * On a shared IRQ the caller must ensure the interrupt is disabled
1540 * on the card it drives before calling this function. The function
1541 * does not return until any executing interrupts for this IRQ
1544 * This function must not be called from interrupt context.
1546 void free_irq(unsigned int irq, void *dev_id)
1548 struct irq_desc *desc = irq_to_desc(irq);
1550 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1554 if (WARN_ON(desc->affinity_notify))
1555 desc->affinity_notify = NULL;
1558 kfree(__free_irq(irq, dev_id));
1560 EXPORT_SYMBOL(free_irq);
1563 * request_threaded_irq - allocate an interrupt line
1564 * @irq: Interrupt line to allocate
1565 * @handler: Function to be called when the IRQ occurs.
1566 * Primary handler for threaded interrupts
1567 * If NULL and thread_fn != NULL the default
1568 * primary handler is installed
1569 * @thread_fn: Function called from the irq handler thread
1570 * If NULL, no irq thread is created
1571 * @irqflags: Interrupt type flags
1572 * @devname: An ascii name for the claiming device
1573 * @dev_id: A cookie passed back to the handler function
1575 * This call allocates interrupt resources and enables the
1576 * interrupt line and IRQ handling. From the point this
1577 * call is made your handler function may be invoked. Since
1578 * your handler function must clear any interrupt the board
1579 * raises, you must take care both to initialise your hardware
1580 * and to set up the interrupt handler in the right order.
1582 * If you want to set up a threaded irq handler for your device
1583 * then you need to supply @handler and @thread_fn. @handler is
1584 * still called in hard interrupt context and has to check
1585 * whether the interrupt originates from the device. If yes it
1586 * needs to disable the interrupt on the device and return
1587 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1588 * @thread_fn. This split handler design is necessary to support
1589 * shared interrupts.
1591 * Dev_id must be globally unique. Normally the address of the
1592 * device data structure is used as the cookie. Since the handler
1593 * receives this value it makes sense to use it.
1595 * If your interrupt is shared you must pass a non NULL dev_id
1596 * as this is required when freeing the interrupt.
1600 * IRQF_SHARED Interrupt is shared
1601 * IRQF_TRIGGER_* Specify active edge(s) or level
1604 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1605 irq_handler_t thread_fn, unsigned long irqflags,
1606 const char *devname, void *dev_id)
1608 struct irqaction *action;
1609 struct irq_desc *desc;
1613 * Sanity-check: shared interrupts must pass in a real dev-ID,
1614 * otherwise we'll have trouble later trying to figure out
1615 * which interrupt is which (messes up the interrupt freeing
1618 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1619 * it cannot be set along with IRQF_NO_SUSPEND.
1621 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1622 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1623 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1626 desc = irq_to_desc(irq);
1630 if (!irq_settings_can_request(desc) ||
1631 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1637 handler = irq_default_primary_handler;
1640 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1644 action->handler = handler;
1645 action->thread_fn = thread_fn;
1646 action->flags = irqflags;
1647 action->name = devname;
1648 action->dev_id = dev_id;
1650 chip_bus_lock(desc);
1651 retval = __setup_irq(irq, desc, action);
1652 chip_bus_sync_unlock(desc);
1655 kfree(action->secondary);
1659 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1660 if (!retval && (irqflags & IRQF_SHARED)) {
1662 * It's a shared IRQ -- the driver ought to be prepared for it
1663 * to happen immediately, so let's make sure....
1664 * We disable the irq to make sure that a 'real' IRQ doesn't
1665 * run in parallel with our fake.
1667 unsigned long flags;
1670 local_irq_save(flags);
1672 handler(irq, dev_id);
1674 local_irq_restore(flags);
1680 EXPORT_SYMBOL(request_threaded_irq);
1683 * request_any_context_irq - allocate an interrupt line
1684 * @irq: Interrupt line to allocate
1685 * @handler: Function to be called when the IRQ occurs.
1686 * Threaded handler for threaded interrupts.
1687 * @flags: Interrupt type flags
1688 * @name: An ascii name for the claiming device
1689 * @dev_id: A cookie passed back to the handler function
1691 * This call allocates interrupt resources and enables the
1692 * interrupt line and IRQ handling. It selects either a
1693 * hardirq or threaded handling method depending on the
1696 * On failure, it returns a negative value. On success,
1697 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1699 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1700 unsigned long flags, const char *name, void *dev_id)
1702 struct irq_desc *desc = irq_to_desc(irq);
1708 if (irq_settings_is_nested_thread(desc)) {
1709 ret = request_threaded_irq(irq, NULL, handler,
1710 flags, name, dev_id);
1711 return !ret ? IRQC_IS_NESTED : ret;
1714 ret = request_irq(irq, handler, flags, name, dev_id);
1715 return !ret ? IRQC_IS_HARDIRQ : ret;
1717 EXPORT_SYMBOL_GPL(request_any_context_irq);
1719 void enable_percpu_irq(unsigned int irq, unsigned int type)
1721 unsigned int cpu = smp_processor_id();
1722 unsigned long flags;
1723 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1728 type &= IRQ_TYPE_SENSE_MASK;
1729 if (type != IRQ_TYPE_NONE) {
1732 ret = __irq_set_trigger(desc, type);
1735 WARN(1, "failed to set type for IRQ%d\n", irq);
1740 irq_percpu_enable(desc, cpu);
1742 irq_put_desc_unlock(desc, flags);
1744 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1747 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1748 * @irq: Linux irq number to check for
1750 * Must be called from a non migratable context. Returns the enable
1751 * state of a per cpu interrupt on the current cpu.
1753 bool irq_percpu_is_enabled(unsigned int irq)
1755 unsigned int cpu = smp_processor_id();
1756 struct irq_desc *desc;
1757 unsigned long flags;
1760 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1764 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1765 irq_put_desc_unlock(desc, flags);
1769 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1771 void disable_percpu_irq(unsigned int irq)
1773 unsigned int cpu = smp_processor_id();
1774 unsigned long flags;
1775 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1780 irq_percpu_disable(desc, cpu);
1781 irq_put_desc_unlock(desc, flags);
1783 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1786 * Internal function to unregister a percpu irqaction.
1788 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1790 struct irq_desc *desc = irq_to_desc(irq);
1791 struct irqaction *action;
1792 unsigned long flags;
1794 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1799 raw_spin_lock_irqsave(&desc->lock, flags);
1801 action = desc->action;
1802 if (!action || action->percpu_dev_id != dev_id) {
1803 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1807 if (!cpumask_empty(desc->percpu_enabled)) {
1808 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1809 irq, cpumask_first(desc->percpu_enabled));
1813 /* Found it - now remove it from the list of entries: */
1814 desc->action = NULL;
1816 raw_spin_unlock_irqrestore(&desc->lock, flags);
1818 unregister_handler_proc(irq, action);
1820 module_put(desc->owner);
1824 raw_spin_unlock_irqrestore(&desc->lock, flags);
1829 * remove_percpu_irq - free a per-cpu interrupt
1830 * @irq: Interrupt line to free
1831 * @act: irqaction for the interrupt
1833 * Used to remove interrupts statically setup by the early boot process.
1835 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1837 struct irq_desc *desc = irq_to_desc(irq);
1839 if (desc && irq_settings_is_per_cpu_devid(desc))
1840 __free_percpu_irq(irq, act->percpu_dev_id);
1844 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1845 * @irq: Interrupt line to free
1846 * @dev_id: Device identity to free
1848 * Remove a percpu interrupt handler. The handler is removed, but
1849 * the interrupt line is not disabled. This must be done on each
1850 * CPU before calling this function. The function does not return
1851 * until any executing interrupts for this IRQ have completed.
1853 * This function must not be called from interrupt context.
1855 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1857 struct irq_desc *desc = irq_to_desc(irq);
1859 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1862 chip_bus_lock(desc);
1863 kfree(__free_percpu_irq(irq, dev_id));
1864 chip_bus_sync_unlock(desc);
1866 EXPORT_SYMBOL_GPL(free_percpu_irq);
1869 * setup_percpu_irq - setup a per-cpu interrupt
1870 * @irq: Interrupt line to setup
1871 * @act: irqaction for the interrupt
1873 * Used to statically setup per-cpu interrupts in the early boot process.
1875 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1877 struct irq_desc *desc = irq_to_desc(irq);
1880 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1882 chip_bus_lock(desc);
1883 retval = __setup_irq(irq, desc, act);
1884 chip_bus_sync_unlock(desc);
1890 * request_percpu_irq - allocate a percpu interrupt line
1891 * @irq: Interrupt line to allocate
1892 * @handler: Function to be called when the IRQ occurs.
1893 * @devname: An ascii name for the claiming device
1894 * @dev_id: A percpu cookie passed back to the handler function
1896 * This call allocates interrupt resources and enables the
1897 * interrupt on the local CPU. If the interrupt is supposed to be
1898 * enabled on other CPUs, it has to be done on each CPU using
1899 * enable_percpu_irq().
1901 * Dev_id must be globally unique. It is a per-cpu variable, and
1902 * the handler gets called with the interrupted CPU's instance of
1905 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1906 const char *devname, void __percpu *dev_id)
1908 struct irqaction *action;
1909 struct irq_desc *desc;
1915 desc = irq_to_desc(irq);
1916 if (!desc || !irq_settings_can_request(desc) ||
1917 !irq_settings_is_per_cpu_devid(desc))
1920 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1924 action->handler = handler;
1925 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1926 action->name = devname;
1927 action->percpu_dev_id = dev_id;
1929 chip_bus_lock(desc);
1930 retval = __setup_irq(irq, desc, action);
1931 chip_bus_sync_unlock(desc);
1938 EXPORT_SYMBOL_GPL(request_percpu_irq);
1941 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
1942 * @irq: Interrupt line that is forwarded to a VM
1943 * @which: One of IRQCHIP_STATE_* the caller wants to know about
1944 * @state: a pointer to a boolean where the state is to be storeed
1946 * This call snapshots the internal irqchip state of an
1947 * interrupt, returning into @state the bit corresponding to
1950 * This function should be called with preemption disabled if the
1951 * interrupt controller has per-cpu registers.
1953 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
1956 struct irq_desc *desc;
1957 struct irq_data *data;
1958 struct irq_chip *chip;
1959 unsigned long flags;
1962 desc = irq_get_desc_buslock(irq, &flags, 0);
1966 data = irq_desc_get_irq_data(desc);
1969 chip = irq_data_get_irq_chip(data);
1970 if (chip->irq_get_irqchip_state)
1972 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1973 data = data->parent_data;
1980 err = chip->irq_get_irqchip_state(data, which, state);
1982 irq_put_desc_busunlock(desc, flags);
1985 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
1988 * irq_set_irqchip_state - set the state of a forwarded interrupt.
1989 * @irq: Interrupt line that is forwarded to a VM
1990 * @which: State to be restored (one of IRQCHIP_STATE_*)
1991 * @val: Value corresponding to @which
1993 * This call sets the internal irqchip state of an interrupt,
1994 * depending on the value of @which.
1996 * This function should be called with preemption disabled if the
1997 * interrupt controller has per-cpu registers.
1999 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2002 struct irq_desc *desc;
2003 struct irq_data *data;
2004 struct irq_chip *chip;
2005 unsigned long flags;
2008 desc = irq_get_desc_buslock(irq, &flags, 0);
2012 data = irq_desc_get_irq_data(desc);
2015 chip = irq_data_get_irq_chip(data);
2016 if (chip->irq_set_irqchip_state)
2018 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2019 data = data->parent_data;
2026 err = chip->irq_set_irqchip_state(data, which, val);
2028 irq_put_desc_busunlock(desc, flags);
2031 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);