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 bool __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_can_set_affinity_usr - Check if affinity of a irq can be set from user space
138 * @irq: Interrupt to check
140 * Like irq_can_set_affinity() above, but additionally checks for the
141 * AFFINITY_MANAGED flag.
143 bool irq_can_set_affinity_usr(unsigned int irq)
145 struct irq_desc *desc = irq_to_desc(irq);
147 return __irq_can_set_affinity(desc) &&
148 !irqd_affinity_is_managed(&desc->irq_data);
152 * irq_set_thread_affinity - Notify irq threads to adjust affinity
153 * @desc: irq descriptor which has affitnity changed
155 * We just set IRQTF_AFFINITY and delegate the affinity setting
156 * to the interrupt thread itself. We can not call
157 * set_cpus_allowed_ptr() here as we hold desc->lock and this
158 * code can be called from hard interrupt context.
160 void irq_set_thread_affinity(struct irq_desc *desc)
162 struct irqaction *action;
164 for_each_action_of_desc(desc, action)
166 set_bit(IRQTF_AFFINITY, &action->thread_flags);
169 #ifdef CONFIG_GENERIC_PENDING_IRQ
170 static inline bool irq_can_move_pcntxt(struct irq_data *data)
172 return irqd_can_move_in_process_context(data);
174 static inline bool irq_move_pending(struct irq_data *data)
176 return irqd_is_setaffinity_pending(data);
179 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
181 cpumask_copy(desc->pending_mask, mask);
184 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
186 cpumask_copy(mask, desc->pending_mask);
189 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
190 static inline bool irq_move_pending(struct irq_data *data) { return false; }
192 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
194 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
197 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
200 struct irq_desc *desc = irq_data_to_desc(data);
201 struct irq_chip *chip = irq_data_get_irq_chip(data);
204 ret = chip->irq_set_affinity(data, mask, force);
206 case IRQ_SET_MASK_OK:
207 case IRQ_SET_MASK_OK_DONE:
208 cpumask_copy(desc->irq_common_data.affinity, mask);
209 case IRQ_SET_MASK_OK_NOCOPY:
210 irq_set_thread_affinity(desc);
217 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
220 struct irq_chip *chip = irq_data_get_irq_chip(data);
221 struct irq_desc *desc = irq_data_to_desc(data);
224 if (!chip || !chip->irq_set_affinity)
227 if (irq_can_move_pcntxt(data)) {
228 ret = irq_do_set_affinity(data, mask, force);
230 irqd_set_move_pending(data);
231 irq_copy_pending(desc, mask);
234 if (desc->affinity_notify) {
235 kref_get(&desc->affinity_notify->kref);
236 if (!schedule_work(&desc->affinity_notify->work)) {
237 /* Work was already scheduled, drop our extra ref */
238 kref_put(&desc->affinity_notify->kref,
239 desc->affinity_notify->release);
242 irqd_set(data, IRQD_AFFINITY_SET);
247 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
249 struct irq_desc *desc = irq_to_desc(irq);
256 raw_spin_lock_irqsave(&desc->lock, flags);
257 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
258 raw_spin_unlock_irqrestore(&desc->lock, flags);
262 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
265 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
269 desc->affinity_hint = m;
270 irq_put_desc_unlock(desc, flags);
271 /* set the initial affinity to prevent every interrupt being on CPU0 */
273 __irq_set_affinity(irq, m, false);
276 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
278 static void irq_affinity_notify(struct work_struct *work)
280 struct irq_affinity_notify *notify =
281 container_of(work, struct irq_affinity_notify, work);
282 struct irq_desc *desc = irq_to_desc(notify->irq);
283 cpumask_var_t cpumask;
286 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
289 raw_spin_lock_irqsave(&desc->lock, flags);
290 if (irq_move_pending(&desc->irq_data))
291 irq_get_pending(cpumask, desc);
293 cpumask_copy(cpumask, desc->irq_common_data.affinity);
294 raw_spin_unlock_irqrestore(&desc->lock, flags);
296 notify->notify(notify, cpumask);
298 free_cpumask_var(cpumask);
300 kref_put(¬ify->kref, notify->release);
304 * irq_set_affinity_notifier - control notification of IRQ affinity changes
305 * @irq: Interrupt for which to enable/disable notification
306 * @notify: Context for notification, or %NULL to disable
307 * notification. Function pointers must be initialised;
308 * the other fields will be initialised by this function.
310 * Must be called in process context. Notification may only be enabled
311 * after the IRQ is allocated and must be disabled before the IRQ is
312 * freed using free_irq().
315 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
317 struct irq_desc *desc = irq_to_desc(irq);
318 struct irq_affinity_notify *old_notify;
321 /* The release function is promised process context */
327 /* Complete initialisation of *notify */
330 kref_init(¬ify->kref);
331 INIT_WORK(¬ify->work, irq_affinity_notify);
334 raw_spin_lock_irqsave(&desc->lock, flags);
335 old_notify = desc->affinity_notify;
336 desc->affinity_notify = notify;
337 raw_spin_unlock_irqrestore(&desc->lock, flags);
340 if (cancel_work_sync(&old_notify->work)) {
341 /* Pending work had a ref, put that one too */
342 kref_put(&old_notify->kref, old_notify->release);
344 kref_put(&old_notify->kref, old_notify->release);
349 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
351 #ifndef CONFIG_AUTO_IRQ_AFFINITY
353 * Generic version of the affinity autoselector.
355 static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
357 struct cpumask *set = irq_default_affinity;
358 int node = irq_desc_get_node(desc);
360 /* Excludes PER_CPU and NO_BALANCE interrupts */
361 if (!__irq_can_set_affinity(desc))
365 * Preserve the managed affinity setting and an userspace affinity
366 * setup, but make sure that one of the targets is online.
368 if (irqd_affinity_is_managed(&desc->irq_data) ||
369 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
370 if (cpumask_intersects(desc->irq_common_data.affinity,
372 set = desc->irq_common_data.affinity;
374 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
377 cpumask_and(mask, cpu_online_mask, set);
378 if (node != NUMA_NO_NODE) {
379 const struct cpumask *nodemask = cpumask_of_node(node);
381 /* make sure at least one of the cpus in nodemask is online */
382 if (cpumask_intersects(mask, nodemask))
383 cpumask_and(mask, mask, nodemask);
385 irq_do_set_affinity(&desc->irq_data, mask, false);
389 /* Wrapper for ALPHA specific affinity selector magic */
390 static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
392 return irq_select_affinity(irq_desc_get_irq(d));
397 * Called when affinity is set via /proc/irq
399 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
401 struct irq_desc *desc = irq_to_desc(irq);
405 raw_spin_lock_irqsave(&desc->lock, flags);
406 ret = setup_affinity(desc, mask);
407 raw_spin_unlock_irqrestore(&desc->lock, flags);
413 setup_affinity(struct irq_desc *desc, struct cpumask *mask)
420 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
421 * @irq: interrupt number to set affinity
422 * @vcpu_info: vCPU specific data
424 * This function uses the vCPU specific data to set the vCPU
425 * affinity for an irq. The vCPU specific data is passed from
426 * outside, such as KVM. One example code path is as below:
427 * KVM -> IOMMU -> irq_set_vcpu_affinity().
429 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
432 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
433 struct irq_data *data;
434 struct irq_chip *chip;
440 data = irq_desc_get_irq_data(desc);
441 chip = irq_data_get_irq_chip(data);
442 if (chip && chip->irq_set_vcpu_affinity)
443 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
444 irq_put_desc_unlock(desc, flags);
448 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
450 void __disable_irq(struct irq_desc *desc)
456 static int __disable_irq_nosync(unsigned int irq)
459 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
464 irq_put_desc_busunlock(desc, flags);
469 * disable_irq_nosync - disable an irq without waiting
470 * @irq: Interrupt to disable
472 * Disable the selected interrupt line. Disables and Enables are
474 * Unlike disable_irq(), this function does not ensure existing
475 * instances of the IRQ handler have completed before returning.
477 * This function may be called from IRQ context.
479 void disable_irq_nosync(unsigned int irq)
481 __disable_irq_nosync(irq);
483 EXPORT_SYMBOL(disable_irq_nosync);
486 * disable_irq - disable an irq and wait for completion
487 * @irq: Interrupt to disable
489 * Disable the selected interrupt line. Enables and Disables are
491 * This function waits for any pending IRQ handlers for this interrupt
492 * to complete before returning. If you use this function while
493 * holding a resource the IRQ handler may need you will deadlock.
495 * This function may be called - with care - from IRQ context.
497 void disable_irq(unsigned int irq)
499 if (!__disable_irq_nosync(irq))
500 synchronize_irq(irq);
502 EXPORT_SYMBOL(disable_irq);
505 * disable_hardirq - disables an irq and waits for hardirq completion
506 * @irq: Interrupt to disable
508 * Disable the selected interrupt line. Enables and Disables are
510 * This function waits for any pending hard IRQ handlers for this
511 * interrupt to complete before returning. If you use this function while
512 * holding a resource the hard IRQ handler may need you will deadlock.
514 * When used to optimistically disable an interrupt from atomic context
515 * the return value must be checked.
517 * Returns: false if a threaded handler is active.
519 * This function may be called - with care - from IRQ context.
521 bool disable_hardirq(unsigned int irq)
523 if (!__disable_irq_nosync(irq))
524 return synchronize_hardirq(irq);
528 EXPORT_SYMBOL_GPL(disable_hardirq);
530 void __enable_irq(struct irq_desc *desc)
532 switch (desc->depth) {
535 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
536 irq_desc_get_irq(desc));
539 if (desc->istate & IRQS_SUSPENDED)
541 /* Prevent probing on this irq: */
542 irq_settings_set_noprobe(desc);
544 check_irq_resend(desc);
553 * enable_irq - enable handling of an irq
554 * @irq: Interrupt to enable
556 * Undoes the effect of one call to disable_irq(). If this
557 * matches the last disable, processing of interrupts on this
558 * IRQ line is re-enabled.
560 * This function may be called from IRQ context only when
561 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
563 void enable_irq(unsigned int irq)
566 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
570 if (WARN(!desc->irq_data.chip,
571 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
576 irq_put_desc_busunlock(desc, flags);
578 EXPORT_SYMBOL(enable_irq);
580 static int set_irq_wake_real(unsigned int irq, unsigned int on)
582 struct irq_desc *desc = irq_to_desc(irq);
585 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
588 if (desc->irq_data.chip->irq_set_wake)
589 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
595 * irq_set_irq_wake - control irq power management wakeup
596 * @irq: interrupt to control
597 * @on: enable/disable power management wakeup
599 * Enable/disable power management wakeup mode, which is
600 * disabled by default. Enables and disables must match,
601 * just as they match for non-wakeup mode support.
603 * Wakeup mode lets this IRQ wake the system from sleep
604 * states like "suspend to RAM".
606 int irq_set_irq_wake(unsigned int irq, unsigned int on)
609 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
615 /* wakeup-capable irqs can be shared between drivers that
616 * don't need to have the same sleep mode behaviors.
619 if (desc->wake_depth++ == 0) {
620 ret = set_irq_wake_real(irq, on);
622 desc->wake_depth = 0;
624 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
627 if (desc->wake_depth == 0) {
628 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
629 } else if (--desc->wake_depth == 0) {
630 ret = set_irq_wake_real(irq, on);
632 desc->wake_depth = 1;
634 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
637 irq_put_desc_busunlock(desc, flags);
640 EXPORT_SYMBOL(irq_set_irq_wake);
643 * Internal function that tells the architecture code whether a
644 * particular irq has been exclusively allocated or is available
647 int can_request_irq(unsigned int irq, unsigned long irqflags)
650 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
656 if (irq_settings_can_request(desc)) {
658 irqflags & desc->action->flags & IRQF_SHARED)
661 irq_put_desc_unlock(desc, flags);
665 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
667 struct irq_chip *chip = desc->irq_data.chip;
670 if (!chip || !chip->irq_set_type) {
672 * IRQF_TRIGGER_* but the PIC does not support multiple
675 pr_debug("No set_type function for IRQ %d (%s)\n",
676 irq_desc_get_irq(desc),
677 chip ? (chip->name ? : "unknown") : "unknown");
681 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
682 if (!irqd_irq_masked(&desc->irq_data))
684 if (!irqd_irq_disabled(&desc->irq_data))
688 /* Mask all flags except trigger mode */
689 flags &= IRQ_TYPE_SENSE_MASK;
690 ret = chip->irq_set_type(&desc->irq_data, flags);
693 case IRQ_SET_MASK_OK:
694 case IRQ_SET_MASK_OK_DONE:
695 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
696 irqd_set(&desc->irq_data, flags);
698 case IRQ_SET_MASK_OK_NOCOPY:
699 flags = irqd_get_trigger_type(&desc->irq_data);
700 irq_settings_set_trigger_mask(desc, flags);
701 irqd_clear(&desc->irq_data, IRQD_LEVEL);
702 irq_settings_clr_level(desc);
703 if (flags & IRQ_TYPE_LEVEL_MASK) {
704 irq_settings_set_level(desc);
705 irqd_set(&desc->irq_data, IRQD_LEVEL);
711 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
712 flags, irq_desc_get_irq(desc), chip->irq_set_type);
719 #ifdef CONFIG_HARDIRQS_SW_RESEND
720 int irq_set_parent(int irq, int parent_irq)
723 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
728 desc->parent_irq = parent_irq;
730 irq_put_desc_unlock(desc, flags);
733 EXPORT_SYMBOL_GPL(irq_set_parent);
737 * Default primary interrupt handler for threaded interrupts. Is
738 * assigned as primary handler when request_threaded_irq is called
739 * with handler == NULL. Useful for oneshot interrupts.
741 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
743 return IRQ_WAKE_THREAD;
747 * Primary handler for nested threaded interrupts. Should never be
750 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
752 WARN(1, "Primary handler called for nested irq %d\n", irq);
756 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
758 WARN(1, "Secondary action handler called for irq %d\n", irq);
762 static int irq_wait_for_interrupt(struct irqaction *action)
764 set_current_state(TASK_INTERRUPTIBLE);
766 while (!kthread_should_stop()) {
768 if (test_and_clear_bit(IRQTF_RUNTHREAD,
769 &action->thread_flags)) {
770 __set_current_state(TASK_RUNNING);
774 set_current_state(TASK_INTERRUPTIBLE);
776 __set_current_state(TASK_RUNNING);
781 * Oneshot interrupts keep the irq line masked until the threaded
782 * handler finished. unmask if the interrupt has not been disabled and
785 static void irq_finalize_oneshot(struct irq_desc *desc,
786 struct irqaction *action)
788 if (!(desc->istate & IRQS_ONESHOT) ||
789 action->handler == irq_forced_secondary_handler)
793 raw_spin_lock_irq(&desc->lock);
796 * Implausible though it may be we need to protect us against
797 * the following scenario:
799 * The thread is faster done than the hard interrupt handler
800 * on the other CPU. If we unmask the irq line then the
801 * interrupt can come in again and masks the line, leaves due
802 * to IRQS_INPROGRESS and the irq line is masked forever.
804 * This also serializes the state of shared oneshot handlers
805 * versus "desc->threads_onehsot |= action->thread_mask;" in
806 * irq_wake_thread(). See the comment there which explains the
809 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
810 raw_spin_unlock_irq(&desc->lock);
811 chip_bus_sync_unlock(desc);
817 * Now check again, whether the thread should run. Otherwise
818 * we would clear the threads_oneshot bit of this thread which
821 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
824 desc->threads_oneshot &= ~action->thread_mask;
826 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
827 irqd_irq_masked(&desc->irq_data))
828 unmask_threaded_irq(desc);
831 raw_spin_unlock_irq(&desc->lock);
832 chip_bus_sync_unlock(desc);
837 * Check whether we need to change the affinity of the interrupt thread.
840 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
845 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
849 * In case we are out of memory we set IRQTF_AFFINITY again and
850 * try again next time
852 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
853 set_bit(IRQTF_AFFINITY, &action->thread_flags);
857 raw_spin_lock_irq(&desc->lock);
859 * This code is triggered unconditionally. Check the affinity
860 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
862 if (cpumask_available(desc->irq_common_data.affinity))
863 cpumask_copy(mask, desc->irq_common_data.affinity);
866 raw_spin_unlock_irq(&desc->lock);
869 set_cpus_allowed_ptr(current, mask);
870 free_cpumask_var(mask);
874 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
878 * Interrupts which are not explicitely requested as threaded
879 * interrupts rely on the implicit bh/preempt disable of the hard irq
880 * context. So we need to disable bh here to avoid deadlocks and other
884 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
889 if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE))
891 ret = action->thread_fn(action->irq, action->dev_id);
892 if (ret == IRQ_HANDLED)
893 atomic_inc(&desc->threads_handled);
895 irq_finalize_oneshot(desc, action);
896 if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE))
903 * Interrupts explicitly requested as threaded interrupts want to be
904 * preemtible - many of them need to sleep and wait for slow busses to
907 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
908 struct irqaction *action)
912 ret = action->thread_fn(action->irq, action->dev_id);
913 if (ret == IRQ_HANDLED)
914 atomic_inc(&desc->threads_handled);
916 irq_finalize_oneshot(desc, action);
920 static void wake_threads_waitq(struct irq_desc *desc)
922 if (atomic_dec_and_test(&desc->threads_active))
923 wake_up(&desc->wait_for_threads);
926 static void irq_thread_dtor(struct callback_head *unused)
928 struct task_struct *tsk = current;
929 struct irq_desc *desc;
930 struct irqaction *action;
932 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
935 action = kthread_data(tsk);
937 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
938 tsk->comm, tsk->pid, action->irq);
941 desc = irq_to_desc(action->irq);
943 * If IRQTF_RUNTHREAD is set, we need to decrement
944 * desc->threads_active and wake possible waiters.
946 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
947 wake_threads_waitq(desc);
949 /* Prevent a stale desc->threads_oneshot */
950 irq_finalize_oneshot(desc, action);
953 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
955 struct irqaction *secondary = action->secondary;
957 if (WARN_ON_ONCE(!secondary))
960 raw_spin_lock_irq(&desc->lock);
961 __irq_wake_thread(desc, secondary);
962 raw_spin_unlock_irq(&desc->lock);
966 * Interrupt handler thread
968 static int irq_thread(void *data)
970 struct callback_head on_exit_work;
971 struct irqaction *action = data;
972 struct irq_desc *desc = irq_to_desc(action->irq);
973 irqreturn_t (*handler_fn)(struct irq_desc *desc,
974 struct irqaction *action);
976 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
977 &action->thread_flags))
978 handler_fn = irq_forced_thread_fn;
980 handler_fn = irq_thread_fn;
982 init_task_work(&on_exit_work, irq_thread_dtor);
983 task_work_add(current, &on_exit_work, false);
985 irq_thread_check_affinity(desc, action);
987 while (!irq_wait_for_interrupt(action)) {
988 irqreturn_t action_ret;
990 irq_thread_check_affinity(desc, action);
992 action_ret = handler_fn(desc, action);
993 if (action_ret == IRQ_WAKE_THREAD)
994 irq_wake_secondary(desc, action);
996 wake_threads_waitq(desc);
1000 * This is the regular exit path. __free_irq() is stopping the
1001 * thread via kthread_stop() after calling
1002 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
1003 * oneshot mask bit can be set. We cannot verify that as we
1004 * cannot touch the oneshot mask at this point anymore as
1005 * __setup_irq() might have given out currents thread_mask
1008 task_work_cancel(current, irq_thread_dtor);
1013 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1014 * @irq: Interrupt line
1015 * @dev_id: Device identity for which the thread should be woken
1018 void irq_wake_thread(unsigned int irq, void *dev_id)
1020 struct irq_desc *desc = irq_to_desc(irq);
1021 struct irqaction *action;
1022 unsigned long flags;
1024 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1027 raw_spin_lock_irqsave(&desc->lock, flags);
1028 for_each_action_of_desc(desc, action) {
1029 if (action->dev_id == dev_id) {
1031 __irq_wake_thread(desc, action);
1035 raw_spin_unlock_irqrestore(&desc->lock, flags);
1037 EXPORT_SYMBOL_GPL(irq_wake_thread);
1039 static int irq_setup_forced_threading(struct irqaction *new)
1041 if (!force_irqthreads)
1043 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1047 * No further action required for interrupts which are requested as
1048 * threaded interrupts already
1050 if (new->handler == irq_default_primary_handler)
1053 new->flags |= IRQF_ONESHOT;
1056 * Handle the case where we have a real primary handler and a
1057 * thread handler. We force thread them as well by creating a
1060 if (new->handler && new->thread_fn) {
1061 /* Allocate the secondary action */
1062 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1063 if (!new->secondary)
1065 new->secondary->handler = irq_forced_secondary_handler;
1066 new->secondary->thread_fn = new->thread_fn;
1067 new->secondary->dev_id = new->dev_id;
1068 new->secondary->irq = new->irq;
1069 new->secondary->name = new->name;
1071 /* Deal with the primary handler */
1072 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1073 new->thread_fn = new->handler;
1074 new->handler = irq_default_primary_handler;
1078 static int irq_request_resources(struct irq_desc *desc)
1080 struct irq_data *d = &desc->irq_data;
1081 struct irq_chip *c = d->chip;
1083 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1086 static void irq_release_resources(struct irq_desc *desc)
1088 struct irq_data *d = &desc->irq_data;
1089 struct irq_chip *c = d->chip;
1091 if (c->irq_release_resources)
1092 c->irq_release_resources(d);
1096 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1098 struct task_struct *t;
1099 struct sched_param param = {
1100 .sched_priority = MAX_USER_RT_PRIO/2,
1104 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1107 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1109 param.sched_priority -= 1;
1115 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1118 * We keep the reference to the task struct even if
1119 * the thread dies to avoid that the interrupt code
1120 * references an already freed task_struct.
1125 * Tell the thread to set its affinity. This is
1126 * important for shared interrupt handlers as we do
1127 * not invoke setup_affinity() for the secondary
1128 * handlers as everything is already set up. Even for
1129 * interrupts marked with IRQF_NO_BALANCE this is
1130 * correct as we want the thread to move to the cpu(s)
1131 * on which the requesting code placed the interrupt.
1133 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1138 * Internal function to register an irqaction - typically used to
1139 * allocate special interrupts that are part of the architecture.
1142 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1144 struct irqaction *old, **old_ptr;
1145 unsigned long flags, thread_mask = 0;
1146 int ret, nested, shared = 0;
1152 if (desc->irq_data.chip == &no_irq_chip)
1154 if (!try_module_get(desc->owner))
1160 * If the trigger type is not specified by the caller,
1161 * then use the default for this interrupt.
1163 if (!(new->flags & IRQF_TRIGGER_MASK))
1164 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1167 * Check whether the interrupt nests into another interrupt
1170 nested = irq_settings_is_nested_thread(desc);
1172 if (!new->thread_fn) {
1177 * Replace the primary handler which was provided from
1178 * the driver for non nested interrupt handling by the
1179 * dummy function which warns when called.
1181 new->handler = irq_nested_primary_handler;
1183 if (irq_settings_can_thread(desc)) {
1184 ret = irq_setup_forced_threading(new);
1191 * Create a handler thread when a thread function is supplied
1192 * and the interrupt does not nest into another interrupt
1195 if (new->thread_fn && !nested) {
1196 ret = setup_irq_thread(new, irq, false);
1199 if (new->secondary) {
1200 ret = setup_irq_thread(new->secondary, irq, true);
1206 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1212 * Drivers are often written to work w/o knowledge about the
1213 * underlying irq chip implementation, so a request for a
1214 * threaded irq without a primary hard irq context handler
1215 * requires the ONESHOT flag to be set. Some irq chips like
1216 * MSI based interrupts are per se one shot safe. Check the
1217 * chip flags, so we can avoid the unmask dance at the end of
1218 * the threaded handler for those.
1220 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1221 new->flags &= ~IRQF_ONESHOT;
1224 * The following block of code has to be executed atomically
1226 raw_spin_lock_irqsave(&desc->lock, flags);
1227 old_ptr = &desc->action;
1231 * Can't share interrupts unless both agree to and are
1232 * the same type (level, edge, polarity). So both flag
1233 * fields must have IRQF_SHARED set and the bits which
1234 * set the trigger type must match. Also all must
1237 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1238 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1239 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1242 /* All handlers must agree on per-cpuness */
1243 if ((old->flags & IRQF_PERCPU) !=
1244 (new->flags & IRQF_PERCPU))
1247 /* add new interrupt at end of irq queue */
1250 * Or all existing action->thread_mask bits,
1251 * so we can find the next zero bit for this
1254 thread_mask |= old->thread_mask;
1255 old_ptr = &old->next;
1262 * Setup the thread mask for this irqaction for ONESHOT. For
1263 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1264 * conditional in irq_wake_thread().
1266 if (new->flags & IRQF_ONESHOT) {
1268 * Unlikely to have 32 resp 64 irqs sharing one line,
1271 if (thread_mask == ~0UL) {
1276 * The thread_mask for the action is or'ed to
1277 * desc->thread_active to indicate that the
1278 * IRQF_ONESHOT thread handler has been woken, but not
1279 * yet finished. The bit is cleared when a thread
1280 * completes. When all threads of a shared interrupt
1281 * line have completed desc->threads_active becomes
1282 * zero and the interrupt line is unmasked. See
1283 * handle.c:irq_wake_thread() for further information.
1285 * If no thread is woken by primary (hard irq context)
1286 * interrupt handlers, then desc->threads_active is
1287 * also checked for zero to unmask the irq line in the
1288 * affected hard irq flow handlers
1289 * (handle_[fasteoi|level]_irq).
1291 * The new action gets the first zero bit of
1292 * thread_mask assigned. See the loop above which or's
1293 * all existing action->thread_mask bits.
1295 new->thread_mask = 1 << ffz(thread_mask);
1297 } else if (new->handler == irq_default_primary_handler &&
1298 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1300 * The interrupt was requested with handler = NULL, so
1301 * we use the default primary handler for it. But it
1302 * does not have the oneshot flag set. In combination
1303 * with level interrupts this is deadly, because the
1304 * default primary handler just wakes the thread, then
1305 * the irq lines is reenabled, but the device still
1306 * has the level irq asserted. Rinse and repeat....
1308 * While this works for edge type interrupts, we play
1309 * it safe and reject unconditionally because we can't
1310 * say for sure which type this interrupt really
1311 * has. The type flags are unreliable as the
1312 * underlying chip implementation can override them.
1314 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1321 ret = irq_request_resources(desc);
1323 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1324 new->name, irq, desc->irq_data.chip->name);
1328 init_waitqueue_head(&desc->wait_for_threads);
1330 /* Setup the type (level, edge polarity) if configured: */
1331 if (new->flags & IRQF_TRIGGER_MASK) {
1332 ret = __irq_set_trigger(desc,
1333 new->flags & IRQF_TRIGGER_MASK);
1336 irq_release_resources(desc);
1341 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1342 IRQS_ONESHOT | IRQS_WAITING);
1343 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1345 if (new->flags & IRQF_PERCPU) {
1346 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1347 irq_settings_set_per_cpu(desc);
1350 if (new->flags & IRQF_ONESHOT)
1351 desc->istate |= IRQS_ONESHOT;
1353 if (irq_settings_can_autoenable(desc))
1354 irq_startup(desc, true);
1356 /* Undo nested disables: */
1359 /* Exclude IRQ from balancing if requested */
1360 if (new->flags & IRQF_NOBALANCING) {
1361 irq_settings_set_no_balancing(desc);
1362 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1365 /* Set default affinity mask once everything is setup */
1366 setup_affinity(desc, mask);
1368 } else if (new->flags & IRQF_TRIGGER_MASK) {
1369 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1370 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1373 /* hope the handler works with current trigger mode */
1374 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1380 irq_pm_install_action(desc, new);
1382 /* Reset broken irq detection when installing new handler */
1383 desc->irq_count = 0;
1384 desc->irqs_unhandled = 0;
1387 * Check whether we disabled the irq via the spurious handler
1388 * before. Reenable it and give it another chance.
1390 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1391 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1395 raw_spin_unlock_irqrestore(&desc->lock, flags);
1398 * Strictly no need to wake it up, but hung_task complains
1399 * when no hard interrupt wakes the thread up.
1402 wake_up_process(new->thread);
1404 wake_up_process(new->secondary->thread);
1406 register_irq_proc(irq, desc);
1408 register_handler_proc(irq, new);
1409 free_cpumask_var(mask);
1414 if (!(new->flags & IRQF_PROBE_SHARED)) {
1415 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1416 irq, new->flags, new->name, old->flags, old->name);
1417 #ifdef CONFIG_DEBUG_SHIRQ
1424 raw_spin_unlock_irqrestore(&desc->lock, flags);
1425 free_cpumask_var(mask);
1429 struct task_struct *t = new->thread;
1435 if (new->secondary && new->secondary->thread) {
1436 struct task_struct *t = new->secondary->thread;
1438 new->secondary->thread = NULL;
1443 module_put(desc->owner);
1448 * setup_irq - setup an interrupt
1449 * @irq: Interrupt line to setup
1450 * @act: irqaction for the interrupt
1452 * Used to statically setup interrupts in the early boot process.
1454 int setup_irq(unsigned int irq, struct irqaction *act)
1457 struct irq_desc *desc = irq_to_desc(irq);
1459 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1462 retval = irq_chip_pm_get(&desc->irq_data);
1466 chip_bus_lock(desc);
1467 retval = __setup_irq(irq, desc, act);
1468 chip_bus_sync_unlock(desc);
1471 irq_chip_pm_put(&desc->irq_data);
1475 EXPORT_SYMBOL_GPL(setup_irq);
1478 * Internal function to unregister an irqaction - used to free
1479 * regular and special interrupts that are part of the architecture.
1481 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1483 struct irq_desc *desc = irq_to_desc(irq);
1484 struct irqaction *action, **action_ptr;
1485 unsigned long flags;
1487 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1492 chip_bus_lock(desc);
1493 raw_spin_lock_irqsave(&desc->lock, flags);
1496 * There can be multiple actions per IRQ descriptor, find the right
1497 * one based on the dev_id:
1499 action_ptr = &desc->action;
1501 action = *action_ptr;
1504 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1505 raw_spin_unlock_irqrestore(&desc->lock, flags);
1506 chip_bus_sync_unlock(desc);
1510 if (action->dev_id == dev_id)
1512 action_ptr = &action->next;
1515 /* Found it - now remove it from the list of entries: */
1516 *action_ptr = action->next;
1518 irq_pm_remove_action(desc, action);
1520 /* If this was the last handler, shut down the IRQ line: */
1521 if (!desc->action) {
1522 irq_settings_clr_disable_unlazy(desc);
1524 irq_release_resources(desc);
1528 /* make sure affinity_hint is cleaned up */
1529 if (WARN_ON_ONCE(desc->affinity_hint))
1530 desc->affinity_hint = NULL;
1533 raw_spin_unlock_irqrestore(&desc->lock, flags);
1534 chip_bus_sync_unlock(desc);
1536 unregister_handler_proc(irq, action);
1538 /* Make sure it's not being used on another CPU: */
1539 synchronize_irq(irq);
1541 #ifdef CONFIG_DEBUG_SHIRQ
1543 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1544 * event to happen even now it's being freed, so let's make sure that
1545 * is so by doing an extra call to the handler ....
1547 * ( We do this after actually deregistering it, to make sure that a
1548 * 'real' IRQ doesn't run in * parallel with our fake. )
1550 if (action->flags & IRQF_SHARED) {
1551 local_irq_save(flags);
1552 action->handler(irq, dev_id);
1553 local_irq_restore(flags);
1557 if (action->thread) {
1558 kthread_stop(action->thread);
1559 put_task_struct(action->thread);
1560 if (action->secondary && action->secondary->thread) {
1561 kthread_stop(action->secondary->thread);
1562 put_task_struct(action->secondary->thread);
1566 irq_chip_pm_put(&desc->irq_data);
1567 module_put(desc->owner);
1568 kfree(action->secondary);
1573 * remove_irq - free an interrupt
1574 * @irq: Interrupt line to free
1575 * @act: irqaction for the interrupt
1577 * Used to remove interrupts statically setup by the early boot process.
1579 void remove_irq(unsigned int irq, struct irqaction *act)
1581 struct irq_desc *desc = irq_to_desc(irq);
1583 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1584 __free_irq(irq, act->dev_id);
1586 EXPORT_SYMBOL_GPL(remove_irq);
1589 * free_irq - free an interrupt allocated with request_irq
1590 * @irq: Interrupt line to free
1591 * @dev_id: Device identity to free
1593 * Remove an interrupt handler. The handler is removed and if the
1594 * interrupt line is no longer in use by any driver it is disabled.
1595 * On a shared IRQ the caller must ensure the interrupt is disabled
1596 * on the card it drives before calling this function. The function
1597 * does not return until any executing interrupts for this IRQ
1600 * This function must not be called from interrupt context.
1602 void free_irq(unsigned int irq, void *dev_id)
1604 struct irq_desc *desc = irq_to_desc(irq);
1606 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1610 if (WARN_ON(desc->affinity_notify))
1611 desc->affinity_notify = NULL;
1614 kfree(__free_irq(irq, dev_id));
1616 EXPORT_SYMBOL(free_irq);
1619 * request_threaded_irq - allocate an interrupt line
1620 * @irq: Interrupt line to allocate
1621 * @handler: Function to be called when the IRQ occurs.
1622 * Primary handler for threaded interrupts
1623 * If NULL and thread_fn != NULL the default
1624 * primary handler is installed
1625 * @thread_fn: Function called from the irq handler thread
1626 * If NULL, no irq thread is created
1627 * @irqflags: Interrupt type flags
1628 * @devname: An ascii name for the claiming device
1629 * @dev_id: A cookie passed back to the handler function
1631 * This call allocates interrupt resources and enables the
1632 * interrupt line and IRQ handling. From the point this
1633 * call is made your handler function may be invoked. Since
1634 * your handler function must clear any interrupt the board
1635 * raises, you must take care both to initialise your hardware
1636 * and to set up the interrupt handler in the right order.
1638 * If you want to set up a threaded irq handler for your device
1639 * then you need to supply @handler and @thread_fn. @handler is
1640 * still called in hard interrupt context and has to check
1641 * whether the interrupt originates from the device. If yes it
1642 * needs to disable the interrupt on the device and return
1643 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1644 * @thread_fn. This split handler design is necessary to support
1645 * shared interrupts.
1647 * Dev_id must be globally unique. Normally the address of the
1648 * device data structure is used as the cookie. Since the handler
1649 * receives this value it makes sense to use it.
1651 * If your interrupt is shared you must pass a non NULL dev_id
1652 * as this is required when freeing the interrupt.
1656 * IRQF_SHARED Interrupt is shared
1657 * IRQF_TRIGGER_* Specify active edge(s) or level
1660 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1661 irq_handler_t thread_fn, unsigned long irqflags,
1662 const char *devname, void *dev_id)
1664 struct irqaction *action;
1665 struct irq_desc *desc;
1668 if (irq == IRQ_NOTCONNECTED)
1672 * Sanity-check: shared interrupts must pass in a real dev-ID,
1673 * otherwise we'll have trouble later trying to figure out
1674 * which interrupt is which (messes up the interrupt freeing
1677 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1678 * it cannot be set along with IRQF_NO_SUSPEND.
1680 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1681 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1682 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1685 desc = irq_to_desc(irq);
1689 if (!irq_settings_can_request(desc) ||
1690 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1696 handler = irq_default_primary_handler;
1699 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1703 action->handler = handler;
1704 action->thread_fn = thread_fn;
1705 action->flags = irqflags;
1706 action->name = devname;
1707 action->dev_id = dev_id;
1709 retval = irq_chip_pm_get(&desc->irq_data);
1715 chip_bus_lock(desc);
1716 retval = __setup_irq(irq, desc, action);
1717 chip_bus_sync_unlock(desc);
1720 irq_chip_pm_put(&desc->irq_data);
1721 kfree(action->secondary);
1725 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1726 if (!retval && (irqflags & IRQF_SHARED)) {
1728 * It's a shared IRQ -- the driver ought to be prepared for it
1729 * to happen immediately, so let's make sure....
1730 * We disable the irq to make sure that a 'real' IRQ doesn't
1731 * run in parallel with our fake.
1733 unsigned long flags;
1736 local_irq_save(flags);
1738 handler(irq, dev_id);
1740 local_irq_restore(flags);
1746 EXPORT_SYMBOL(request_threaded_irq);
1749 * request_any_context_irq - allocate an interrupt line
1750 * @irq: Interrupt line to allocate
1751 * @handler: Function to be called when the IRQ occurs.
1752 * Threaded handler for threaded interrupts.
1753 * @flags: Interrupt type flags
1754 * @name: An ascii name for the claiming device
1755 * @dev_id: A cookie passed back to the handler function
1757 * This call allocates interrupt resources and enables the
1758 * interrupt line and IRQ handling. It selects either a
1759 * hardirq or threaded handling method depending on the
1762 * On failure, it returns a negative value. On success,
1763 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1765 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1766 unsigned long flags, const char *name, void *dev_id)
1768 struct irq_desc *desc;
1771 if (irq == IRQ_NOTCONNECTED)
1774 desc = irq_to_desc(irq);
1778 if (irq_settings_is_nested_thread(desc)) {
1779 ret = request_threaded_irq(irq, NULL, handler,
1780 flags, name, dev_id);
1781 return !ret ? IRQC_IS_NESTED : ret;
1784 ret = request_irq(irq, handler, flags, name, dev_id);
1785 return !ret ? IRQC_IS_HARDIRQ : ret;
1787 EXPORT_SYMBOL_GPL(request_any_context_irq);
1789 void enable_percpu_irq(unsigned int irq, unsigned int type)
1791 unsigned int cpu = smp_processor_id();
1792 unsigned long flags;
1793 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1799 * If the trigger type is not specified by the caller, then
1800 * use the default for this interrupt.
1802 type &= IRQ_TYPE_SENSE_MASK;
1803 if (type == IRQ_TYPE_NONE)
1804 type = irqd_get_trigger_type(&desc->irq_data);
1806 if (type != IRQ_TYPE_NONE) {
1809 ret = __irq_set_trigger(desc, type);
1812 WARN(1, "failed to set type for IRQ%d\n", irq);
1817 irq_percpu_enable(desc, cpu);
1819 irq_put_desc_unlock(desc, flags);
1821 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1824 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1825 * @irq: Linux irq number to check for
1827 * Must be called from a non migratable context. Returns the enable
1828 * state of a per cpu interrupt on the current cpu.
1830 bool irq_percpu_is_enabled(unsigned int irq)
1832 unsigned int cpu = smp_processor_id();
1833 struct irq_desc *desc;
1834 unsigned long flags;
1837 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1841 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1842 irq_put_desc_unlock(desc, flags);
1846 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1848 void disable_percpu_irq(unsigned int irq)
1850 unsigned int cpu = smp_processor_id();
1851 unsigned long flags;
1852 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1857 irq_percpu_disable(desc, cpu);
1858 irq_put_desc_unlock(desc, flags);
1860 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1863 * Internal function to unregister a percpu irqaction.
1865 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1867 struct irq_desc *desc = irq_to_desc(irq);
1868 struct irqaction *action;
1869 unsigned long flags;
1871 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1876 raw_spin_lock_irqsave(&desc->lock, flags);
1878 action = desc->action;
1879 if (!action || action->percpu_dev_id != dev_id) {
1880 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1884 if (!cpumask_empty(desc->percpu_enabled)) {
1885 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1886 irq, cpumask_first(desc->percpu_enabled));
1890 /* Found it - now remove it from the list of entries: */
1891 desc->action = NULL;
1893 raw_spin_unlock_irqrestore(&desc->lock, flags);
1895 unregister_handler_proc(irq, action);
1897 irq_chip_pm_put(&desc->irq_data);
1898 module_put(desc->owner);
1902 raw_spin_unlock_irqrestore(&desc->lock, flags);
1907 * remove_percpu_irq - free a per-cpu interrupt
1908 * @irq: Interrupt line to free
1909 * @act: irqaction for the interrupt
1911 * Used to remove interrupts statically setup by the early boot process.
1913 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1915 struct irq_desc *desc = irq_to_desc(irq);
1917 if (desc && irq_settings_is_per_cpu_devid(desc))
1918 __free_percpu_irq(irq, act->percpu_dev_id);
1922 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1923 * @irq: Interrupt line to free
1924 * @dev_id: Device identity to free
1926 * Remove a percpu interrupt handler. The handler is removed, but
1927 * the interrupt line is not disabled. This must be done on each
1928 * CPU before calling this function. The function does not return
1929 * until any executing interrupts for this IRQ have completed.
1931 * This function must not be called from interrupt context.
1933 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1935 struct irq_desc *desc = irq_to_desc(irq);
1937 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1940 chip_bus_lock(desc);
1941 kfree(__free_percpu_irq(irq, dev_id));
1942 chip_bus_sync_unlock(desc);
1944 EXPORT_SYMBOL_GPL(free_percpu_irq);
1947 * setup_percpu_irq - setup a per-cpu interrupt
1948 * @irq: Interrupt line to setup
1949 * @act: irqaction for the interrupt
1951 * Used to statically setup per-cpu interrupts in the early boot process.
1953 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1955 struct irq_desc *desc = irq_to_desc(irq);
1958 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1961 retval = irq_chip_pm_get(&desc->irq_data);
1965 chip_bus_lock(desc);
1966 retval = __setup_irq(irq, desc, act);
1967 chip_bus_sync_unlock(desc);
1970 irq_chip_pm_put(&desc->irq_data);
1976 * request_percpu_irq - allocate a percpu interrupt line
1977 * @irq: Interrupt line to allocate
1978 * @handler: Function to be called when the IRQ occurs.
1979 * @devname: An ascii name for the claiming device
1980 * @dev_id: A percpu cookie passed back to the handler function
1982 * This call allocates interrupt resources and enables the
1983 * interrupt on the local CPU. If the interrupt is supposed to be
1984 * enabled on other CPUs, it has to be done on each CPU using
1985 * enable_percpu_irq().
1987 * Dev_id must be globally unique. It is a per-cpu variable, and
1988 * the handler gets called with the interrupted CPU's instance of
1991 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1992 const char *devname, void __percpu *dev_id)
1994 struct irqaction *action;
1995 struct irq_desc *desc;
2001 desc = irq_to_desc(irq);
2002 if (!desc || !irq_settings_can_request(desc) ||
2003 !irq_settings_is_per_cpu_devid(desc))
2006 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2010 action->handler = handler;
2011 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
2012 action->name = devname;
2013 action->percpu_dev_id = dev_id;
2015 retval = irq_chip_pm_get(&desc->irq_data);
2021 chip_bus_lock(desc);
2022 retval = __setup_irq(irq, desc, action);
2023 chip_bus_sync_unlock(desc);
2026 irq_chip_pm_put(&desc->irq_data);
2032 EXPORT_SYMBOL_GPL(request_percpu_irq);
2035 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2036 * @irq: Interrupt line that is forwarded to a VM
2037 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2038 * @state: a pointer to a boolean where the state is to be storeed
2040 * This call snapshots the internal irqchip state of an
2041 * interrupt, returning into @state the bit corresponding to
2044 * This function should be called with preemption disabled if the
2045 * interrupt controller has per-cpu registers.
2047 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2050 struct irq_desc *desc;
2051 struct irq_data *data;
2052 struct irq_chip *chip;
2053 unsigned long flags;
2056 desc = irq_get_desc_buslock(irq, &flags, 0);
2060 data = irq_desc_get_irq_data(desc);
2063 chip = irq_data_get_irq_chip(data);
2064 if (chip->irq_get_irqchip_state)
2066 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2067 data = data->parent_data;
2074 err = chip->irq_get_irqchip_state(data, which, state);
2076 irq_put_desc_busunlock(desc, flags);
2079 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2082 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2083 * @irq: Interrupt line that is forwarded to a VM
2084 * @which: State to be restored (one of IRQCHIP_STATE_*)
2085 * @val: Value corresponding to @which
2087 * This call sets the internal irqchip state of an interrupt,
2088 * depending on the value of @which.
2090 * This function should be called with preemption disabled if the
2091 * interrupt controller has per-cpu registers.
2093 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2096 struct irq_desc *desc;
2097 struct irq_data *data;
2098 struct irq_chip *chip;
2099 unsigned long flags;
2102 desc = irq_get_desc_buslock(irq, &flags, 0);
2106 data = irq_desc_get_irq_data(desc);
2109 chip = irq_data_get_irq_chip(data);
2110 if (chip->irq_set_irqchip_state)
2112 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2113 data = data->parent_data;
2120 err = chip->irq_set_irqchip_state(data, which, val);
2122 irq_put_desc_busunlock(desc, flags);
2125 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);