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/sched/task.h>
21 #include <uapi/linux/sched/types.h>
22 #include <linux/task_work.h>
24 #include "internals.h"
26 #ifdef CONFIG_IRQ_FORCED_THREADING
27 __read_mostly bool force_irqthreads;
29 static int __init setup_forced_irqthreads(char *arg)
31 force_irqthreads = true;
34 early_param("threadirqs", setup_forced_irqthreads);
37 static void __synchronize_hardirq(struct irq_desc *desc)
45 * Wait until we're out of the critical section. This might
46 * give the wrong answer due to the lack of memory barriers.
48 while (irqd_irq_inprogress(&desc->irq_data))
51 /* Ok, that indicated we're done: double-check carefully. */
52 raw_spin_lock_irqsave(&desc->lock, flags);
53 inprogress = irqd_irq_inprogress(&desc->irq_data);
54 raw_spin_unlock_irqrestore(&desc->lock, flags);
56 /* Oops, that failed? */
61 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
62 * @irq: interrupt number to wait for
64 * This function waits for any pending hard IRQ handlers for this
65 * interrupt to complete before returning. If you use this
66 * function while holding a resource the IRQ handler may need you
67 * will deadlock. It does not take associated threaded handlers
70 * Do not use this for shutdown scenarios where you must be sure
71 * that all parts (hardirq and threaded handler) have completed.
73 * Returns: false if a threaded handler is active.
75 * This function may be called - with care - from IRQ context.
77 bool synchronize_hardirq(unsigned int irq)
79 struct irq_desc *desc = irq_to_desc(irq);
82 __synchronize_hardirq(desc);
83 return !atomic_read(&desc->threads_active);
88 EXPORT_SYMBOL(synchronize_hardirq);
91 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
92 * @irq: interrupt number to wait for
94 * This function waits for any pending IRQ handlers for this interrupt
95 * to complete before returning. If you use this function while
96 * holding a resource the IRQ handler may need you will deadlock.
98 * This function may be called - with care - from IRQ context.
100 void synchronize_irq(unsigned int irq)
102 struct irq_desc *desc = irq_to_desc(irq);
105 __synchronize_hardirq(desc);
107 * We made sure that no hardirq handler is
108 * running. Now verify that no threaded handlers are
111 wait_event(desc->wait_for_threads,
112 !atomic_read(&desc->threads_active));
115 EXPORT_SYMBOL(synchronize_irq);
118 cpumask_var_t irq_default_affinity;
120 static bool __irq_can_set_affinity(struct irq_desc *desc)
122 if (!desc || !irqd_can_balance(&desc->irq_data) ||
123 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
129 * irq_can_set_affinity - Check if the affinity of a given irq can be set
130 * @irq: Interrupt to check
133 int irq_can_set_affinity(unsigned int irq)
135 return __irq_can_set_affinity(irq_to_desc(irq));
139 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
140 * @irq: Interrupt to check
142 * Like irq_can_set_affinity() above, but additionally checks for the
143 * AFFINITY_MANAGED flag.
145 bool irq_can_set_affinity_usr(unsigned int irq)
147 struct irq_desc *desc = irq_to_desc(irq);
149 return __irq_can_set_affinity(desc) &&
150 !irqd_affinity_is_managed(&desc->irq_data);
154 * irq_set_thread_affinity - Notify irq threads to adjust affinity
155 * @desc: irq descriptor which has affitnity changed
157 * We just set IRQTF_AFFINITY and delegate the affinity setting
158 * to the interrupt thread itself. We can not call
159 * set_cpus_allowed_ptr() here as we hold desc->lock and this
160 * code can be called from hard interrupt context.
162 void irq_set_thread_affinity(struct irq_desc *desc)
164 struct irqaction *action;
166 for_each_action_of_desc(desc, action)
168 set_bit(IRQTF_AFFINITY, &action->thread_flags);
171 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
174 struct irq_desc *desc = irq_data_to_desc(data);
175 struct irq_chip *chip = irq_data_get_irq_chip(data);
178 ret = chip->irq_set_affinity(data, mask, force);
180 case IRQ_SET_MASK_OK:
181 case IRQ_SET_MASK_OK_DONE:
182 cpumask_copy(desc->irq_common_data.affinity, mask);
183 case IRQ_SET_MASK_OK_NOCOPY:
184 irq_set_thread_affinity(desc);
191 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
194 struct irq_chip *chip = irq_data_get_irq_chip(data);
195 struct irq_desc *desc = irq_data_to_desc(data);
198 if (!chip || !chip->irq_set_affinity)
201 if (irq_can_move_pcntxt(data)) {
202 ret = irq_do_set_affinity(data, mask, force);
204 irqd_set_move_pending(data);
205 irq_copy_pending(desc, mask);
208 if (desc->affinity_notify) {
209 kref_get(&desc->affinity_notify->kref);
210 schedule_work(&desc->affinity_notify->work);
212 irqd_set(data, IRQD_AFFINITY_SET);
217 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
219 struct irq_desc *desc = irq_to_desc(irq);
226 raw_spin_lock_irqsave(&desc->lock, flags);
227 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
228 raw_spin_unlock_irqrestore(&desc->lock, flags);
232 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
235 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
239 desc->affinity_hint = m;
240 irq_put_desc_unlock(desc, flags);
241 /* set the initial affinity to prevent every interrupt being on CPU0 */
243 __irq_set_affinity(irq, m, false);
246 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
248 static void irq_affinity_notify(struct work_struct *work)
250 struct irq_affinity_notify *notify =
251 container_of(work, struct irq_affinity_notify, work);
252 struct irq_desc *desc = irq_to_desc(notify->irq);
253 cpumask_var_t cpumask;
256 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
259 raw_spin_lock_irqsave(&desc->lock, flags);
260 if (irq_move_pending(&desc->irq_data))
261 irq_get_pending(cpumask, desc);
263 cpumask_copy(cpumask, desc->irq_common_data.affinity);
264 raw_spin_unlock_irqrestore(&desc->lock, flags);
266 notify->notify(notify, cpumask);
268 free_cpumask_var(cpumask);
270 kref_put(¬ify->kref, notify->release);
274 * irq_set_affinity_notifier - control notification of IRQ affinity changes
275 * @irq: Interrupt for which to enable/disable notification
276 * @notify: Context for notification, or %NULL to disable
277 * notification. Function pointers must be initialised;
278 * the other fields will be initialised by this function.
280 * Must be called in process context. Notification may only be enabled
281 * after the IRQ is allocated and must be disabled before the IRQ is
282 * freed using free_irq().
285 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
287 struct irq_desc *desc = irq_to_desc(irq);
288 struct irq_affinity_notify *old_notify;
291 /* The release function is promised process context */
297 /* Complete initialisation of *notify */
300 kref_init(¬ify->kref);
301 INIT_WORK(¬ify->work, irq_affinity_notify);
304 raw_spin_lock_irqsave(&desc->lock, flags);
305 old_notify = desc->affinity_notify;
306 desc->affinity_notify = notify;
307 raw_spin_unlock_irqrestore(&desc->lock, flags);
310 kref_put(&old_notify->kref, old_notify->release);
314 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
316 #ifndef CONFIG_AUTO_IRQ_AFFINITY
318 * Generic version of the affinity autoselector.
320 int irq_setup_affinity(struct irq_desc *desc)
322 struct cpumask *set = irq_default_affinity;
323 int ret, node = irq_desc_get_node(desc);
324 static DEFINE_RAW_SPINLOCK(mask_lock);
325 static struct cpumask mask;
327 /* Excludes PER_CPU and NO_BALANCE interrupts */
328 if (!__irq_can_set_affinity(desc))
331 raw_spin_lock(&mask_lock);
333 * Preserve the managed affinity setting and a userspace affinity
334 * setup, but make sure that one of the targets is online.
336 if (irqd_affinity_is_managed(&desc->irq_data) ||
337 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
338 if (cpumask_intersects(desc->irq_common_data.affinity,
340 set = desc->irq_common_data.affinity;
342 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
345 cpumask_and(&mask, cpu_online_mask, set);
346 if (node != NUMA_NO_NODE) {
347 const struct cpumask *nodemask = cpumask_of_node(node);
349 /* make sure at least one of the cpus in nodemask is online */
350 if (cpumask_intersects(&mask, nodemask))
351 cpumask_and(&mask, &mask, nodemask);
353 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
354 raw_spin_unlock(&mask_lock);
358 /* Wrapper for ALPHA specific affinity selector magic */
359 int irq_setup_affinity(struct irq_desc *desc)
361 return irq_select_affinity(irq_desc_get_irq(desc));
366 * Called when a bogus affinity is set via /proc/irq
368 int irq_select_affinity_usr(unsigned int irq)
370 struct irq_desc *desc = irq_to_desc(irq);
374 raw_spin_lock_irqsave(&desc->lock, flags);
375 ret = irq_setup_affinity(desc);
376 raw_spin_unlock_irqrestore(&desc->lock, flags);
382 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
383 * @irq: interrupt number to set affinity
384 * @vcpu_info: vCPU specific data
386 * This function uses the vCPU specific data to set the vCPU
387 * affinity for an irq. The vCPU specific data is passed from
388 * outside, such as KVM. One example code path is as below:
389 * KVM -> IOMMU -> irq_set_vcpu_affinity().
391 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
394 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
395 struct irq_data *data;
396 struct irq_chip *chip;
402 data = irq_desc_get_irq_data(desc);
404 chip = irq_data_get_irq_chip(data);
405 if (chip && chip->irq_set_vcpu_affinity)
407 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
408 data = data->parent_data;
415 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
416 irq_put_desc_unlock(desc, flags);
420 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
422 void __disable_irq(struct irq_desc *desc)
428 static int __disable_irq_nosync(unsigned int irq)
431 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
436 irq_put_desc_busunlock(desc, flags);
441 * disable_irq_nosync - disable an irq without waiting
442 * @irq: Interrupt to disable
444 * Disable the selected interrupt line. Disables and Enables are
446 * Unlike disable_irq(), this function does not ensure existing
447 * instances of the IRQ handler have completed before returning.
449 * This function may be called from IRQ context.
451 void disable_irq_nosync(unsigned int irq)
453 __disable_irq_nosync(irq);
455 EXPORT_SYMBOL(disable_irq_nosync);
458 * disable_irq - disable an irq and wait for completion
459 * @irq: Interrupt to disable
461 * Disable the selected interrupt line. Enables and Disables are
463 * This function waits for any pending IRQ handlers for this interrupt
464 * to complete before returning. If you use this function while
465 * holding a resource the IRQ handler may need you will deadlock.
467 * This function may be called - with care - from IRQ context.
469 void disable_irq(unsigned int irq)
471 if (!__disable_irq_nosync(irq))
472 synchronize_irq(irq);
474 EXPORT_SYMBOL(disable_irq);
477 * disable_hardirq - disables an irq and waits for hardirq completion
478 * @irq: Interrupt to disable
480 * Disable the selected interrupt line. Enables and Disables are
482 * This function waits for any pending hard IRQ handlers for this
483 * interrupt to complete before returning. If you use this function while
484 * holding a resource the hard IRQ handler may need you will deadlock.
486 * When used to optimistically disable an interrupt from atomic context
487 * the return value must be checked.
489 * Returns: false if a threaded handler is active.
491 * This function may be called - with care - from IRQ context.
493 bool disable_hardirq(unsigned int irq)
495 if (!__disable_irq_nosync(irq))
496 return synchronize_hardirq(irq);
500 EXPORT_SYMBOL_GPL(disable_hardirq);
502 void __enable_irq(struct irq_desc *desc)
504 switch (desc->depth) {
507 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
508 irq_desc_get_irq(desc));
511 if (desc->istate & IRQS_SUSPENDED)
513 /* Prevent probing on this irq: */
514 irq_settings_set_noprobe(desc);
516 * Call irq_startup() not irq_enable() here because the
517 * interrupt might be marked NOAUTOEN. So irq_startup()
518 * needs to be invoked when it gets enabled the first
519 * time. If it was already started up, then irq_startup()
520 * will invoke irq_enable() under the hood.
522 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
531 * enable_irq - enable handling of an irq
532 * @irq: Interrupt to enable
534 * Undoes the effect of one call to disable_irq(). If this
535 * matches the last disable, processing of interrupts on this
536 * IRQ line is re-enabled.
538 * This function may be called from IRQ context only when
539 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
541 void enable_irq(unsigned int irq)
544 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
548 if (WARN(!desc->irq_data.chip,
549 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
554 irq_put_desc_busunlock(desc, flags);
556 EXPORT_SYMBOL(enable_irq);
558 static int set_irq_wake_real(unsigned int irq, unsigned int on)
560 struct irq_desc *desc = irq_to_desc(irq);
563 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
566 if (desc->irq_data.chip->irq_set_wake)
567 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
573 * irq_set_irq_wake - control irq power management wakeup
574 * @irq: interrupt to control
575 * @on: enable/disable power management wakeup
577 * Enable/disable power management wakeup mode, which is
578 * disabled by default. Enables and disables must match,
579 * just as they match for non-wakeup mode support.
581 * Wakeup mode lets this IRQ wake the system from sleep
582 * states like "suspend to RAM".
584 int irq_set_irq_wake(unsigned int irq, unsigned int on)
587 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
593 /* wakeup-capable irqs can be shared between drivers that
594 * don't need to have the same sleep mode behaviors.
597 if (desc->wake_depth++ == 0) {
598 ret = set_irq_wake_real(irq, on);
600 desc->wake_depth = 0;
602 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
605 if (desc->wake_depth == 0) {
606 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
607 } else if (--desc->wake_depth == 0) {
608 ret = set_irq_wake_real(irq, on);
610 desc->wake_depth = 1;
612 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
615 irq_put_desc_busunlock(desc, flags);
618 EXPORT_SYMBOL(irq_set_irq_wake);
621 * Internal function that tells the architecture code whether a
622 * particular irq has been exclusively allocated or is available
625 int can_request_irq(unsigned int irq, unsigned long irqflags)
628 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
634 if (irq_settings_can_request(desc)) {
636 irqflags & desc->action->flags & IRQF_SHARED)
639 irq_put_desc_unlock(desc, flags);
643 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
645 struct irq_chip *chip = desc->irq_data.chip;
648 if (!chip || !chip->irq_set_type) {
650 * IRQF_TRIGGER_* but the PIC does not support multiple
653 pr_debug("No set_type function for IRQ %d (%s)\n",
654 irq_desc_get_irq(desc),
655 chip ? (chip->name ? : "unknown") : "unknown");
659 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
660 if (!irqd_irq_masked(&desc->irq_data))
662 if (!irqd_irq_disabled(&desc->irq_data))
666 /* Mask all flags except trigger mode */
667 flags &= IRQ_TYPE_SENSE_MASK;
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);
711 EXPORT_SYMBOL_GPL(irq_set_parent);
715 * Default primary interrupt handler for threaded interrupts. Is
716 * assigned as primary handler when request_threaded_irq is called
717 * with handler == NULL. Useful for oneshot interrupts.
719 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
721 return IRQ_WAKE_THREAD;
725 * Primary handler for nested threaded interrupts. Should never be
728 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
730 WARN(1, "Primary handler called for nested irq %d\n", irq);
734 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
736 WARN(1, "Secondary action handler called for irq %d\n", irq);
740 static int irq_wait_for_interrupt(struct irqaction *action)
742 set_current_state(TASK_INTERRUPTIBLE);
744 while (!kthread_should_stop()) {
746 if (test_and_clear_bit(IRQTF_RUNTHREAD,
747 &action->thread_flags)) {
748 __set_current_state(TASK_RUNNING);
752 set_current_state(TASK_INTERRUPTIBLE);
754 __set_current_state(TASK_RUNNING);
759 * Oneshot interrupts keep the irq line masked until the threaded
760 * handler finished. unmask if the interrupt has not been disabled and
763 static void irq_finalize_oneshot(struct irq_desc *desc,
764 struct irqaction *action)
766 if (!(desc->istate & IRQS_ONESHOT) ||
767 action->handler == irq_forced_secondary_handler)
771 raw_spin_lock_irq(&desc->lock);
774 * Implausible though it may be we need to protect us against
775 * the following scenario:
777 * The thread is faster done than the hard interrupt handler
778 * on the other CPU. If we unmask the irq line then the
779 * interrupt can come in again and masks the line, leaves due
780 * to IRQS_INPROGRESS and the irq line is masked forever.
782 * This also serializes the state of shared oneshot handlers
783 * versus "desc->threads_onehsot |= action->thread_mask;" in
784 * irq_wake_thread(). See the comment there which explains the
787 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
788 raw_spin_unlock_irq(&desc->lock);
789 chip_bus_sync_unlock(desc);
795 * Now check again, whether the thread should run. Otherwise
796 * we would clear the threads_oneshot bit of this thread which
799 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
802 desc->threads_oneshot &= ~action->thread_mask;
804 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
805 irqd_irq_masked(&desc->irq_data))
806 unmask_threaded_irq(desc);
809 raw_spin_unlock_irq(&desc->lock);
810 chip_bus_sync_unlock(desc);
815 * Check whether we need to change the affinity of the interrupt thread.
818 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
823 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
827 * In case we are out of memory we set IRQTF_AFFINITY again and
828 * try again next time
830 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
831 set_bit(IRQTF_AFFINITY, &action->thread_flags);
835 raw_spin_lock_irq(&desc->lock);
837 * This code is triggered unconditionally. Check the affinity
838 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
840 if (cpumask_available(desc->irq_common_data.affinity))
841 cpumask_copy(mask, desc->irq_common_data.affinity);
844 raw_spin_unlock_irq(&desc->lock);
847 set_cpus_allowed_ptr(current, mask);
848 free_cpumask_var(mask);
852 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
856 * Interrupts which are not explicitely requested as threaded
857 * interrupts rely on the implicit bh/preempt disable of the hard irq
858 * context. So we need to disable bh here to avoid deadlocks and other
862 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
867 ret = action->thread_fn(action->irq, action->dev_id);
868 irq_finalize_oneshot(desc, action);
874 * Interrupts explicitly requested as threaded interrupts want to be
875 * preemtible - many of them need to sleep and wait for slow busses to
878 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
879 struct irqaction *action)
883 ret = action->thread_fn(action->irq, action->dev_id);
884 irq_finalize_oneshot(desc, action);
888 static void wake_threads_waitq(struct irq_desc *desc)
890 if (atomic_dec_and_test(&desc->threads_active))
891 wake_up(&desc->wait_for_threads);
894 static void irq_thread_dtor(struct callback_head *unused)
896 struct task_struct *tsk = current;
897 struct irq_desc *desc;
898 struct irqaction *action;
900 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
903 action = kthread_data(tsk);
905 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
906 tsk->comm, tsk->pid, action->irq);
909 desc = irq_to_desc(action->irq);
911 * If IRQTF_RUNTHREAD is set, we need to decrement
912 * desc->threads_active and wake possible waiters.
914 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
915 wake_threads_waitq(desc);
917 /* Prevent a stale desc->threads_oneshot */
918 irq_finalize_oneshot(desc, action);
921 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
923 struct irqaction *secondary = action->secondary;
925 if (WARN_ON_ONCE(!secondary))
928 raw_spin_lock_irq(&desc->lock);
929 __irq_wake_thread(desc, secondary);
930 raw_spin_unlock_irq(&desc->lock);
934 * Interrupt handler thread
936 static int irq_thread(void *data)
938 struct callback_head on_exit_work;
939 struct irqaction *action = data;
940 struct irq_desc *desc = irq_to_desc(action->irq);
941 irqreturn_t (*handler_fn)(struct irq_desc *desc,
942 struct irqaction *action);
944 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
945 &action->thread_flags))
946 handler_fn = irq_forced_thread_fn;
948 handler_fn = irq_thread_fn;
950 init_task_work(&on_exit_work, irq_thread_dtor);
951 task_work_add(current, &on_exit_work, false);
953 irq_thread_check_affinity(desc, action);
955 while (!irq_wait_for_interrupt(action)) {
956 irqreturn_t action_ret;
958 irq_thread_check_affinity(desc, action);
960 action_ret = handler_fn(desc, action);
961 if (action_ret == IRQ_HANDLED)
962 atomic_inc(&desc->threads_handled);
963 if (action_ret == IRQ_WAKE_THREAD)
964 irq_wake_secondary(desc, action);
966 wake_threads_waitq(desc);
970 * This is the regular exit path. __free_irq() is stopping the
971 * thread via kthread_stop() after calling
972 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
973 * oneshot mask bit can be set. We cannot verify that as we
974 * cannot touch the oneshot mask at this point anymore as
975 * __setup_irq() might have given out currents thread_mask
978 task_work_cancel(current, irq_thread_dtor);
983 * irq_wake_thread - wake the irq thread for the action identified by dev_id
984 * @irq: Interrupt line
985 * @dev_id: Device identity for which the thread should be woken
988 void irq_wake_thread(unsigned int irq, void *dev_id)
990 struct irq_desc *desc = irq_to_desc(irq);
991 struct irqaction *action;
994 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
997 raw_spin_lock_irqsave(&desc->lock, flags);
998 for_each_action_of_desc(desc, action) {
999 if (action->dev_id == dev_id) {
1001 __irq_wake_thread(desc, action);
1005 raw_spin_unlock_irqrestore(&desc->lock, flags);
1007 EXPORT_SYMBOL_GPL(irq_wake_thread);
1009 static int irq_setup_forced_threading(struct irqaction *new)
1011 if (!force_irqthreads)
1013 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1016 new->flags |= IRQF_ONESHOT;
1019 * Handle the case where we have a real primary handler and a
1020 * thread handler. We force thread them as well by creating a
1023 if (new->handler != irq_default_primary_handler && new->thread_fn) {
1024 /* Allocate the secondary action */
1025 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1026 if (!new->secondary)
1028 new->secondary->handler = irq_forced_secondary_handler;
1029 new->secondary->thread_fn = new->thread_fn;
1030 new->secondary->dev_id = new->dev_id;
1031 new->secondary->irq = new->irq;
1032 new->secondary->name = new->name;
1034 /* Deal with the primary handler */
1035 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1036 new->thread_fn = new->handler;
1037 new->handler = irq_default_primary_handler;
1041 static int irq_request_resources(struct irq_desc *desc)
1043 struct irq_data *d = &desc->irq_data;
1044 struct irq_chip *c = d->chip;
1046 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1049 static void irq_release_resources(struct irq_desc *desc)
1051 struct irq_data *d = &desc->irq_data;
1052 struct irq_chip *c = d->chip;
1054 if (c->irq_release_resources)
1055 c->irq_release_resources(d);
1059 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1061 struct task_struct *t;
1062 struct sched_param param = {
1063 .sched_priority = MAX_USER_RT_PRIO/2,
1067 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1070 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1072 param.sched_priority -= 1;
1078 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1081 * We keep the reference to the task struct even if
1082 * the thread dies to avoid that the interrupt code
1083 * references an already freed task_struct.
1088 * Tell the thread to set its affinity. This is
1089 * important for shared interrupt handlers as we do
1090 * not invoke setup_affinity() for the secondary
1091 * handlers as everything is already set up. Even for
1092 * interrupts marked with IRQF_NO_BALANCE this is
1093 * correct as we want the thread to move to the cpu(s)
1094 * on which the requesting code placed the interrupt.
1096 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1101 * Internal function to register an irqaction - typically used to
1102 * allocate special interrupts that are part of the architecture.
1106 * desc->request_mutex Provides serialization against a concurrent free_irq()
1107 * chip_bus_lock Provides serialization for slow bus operations
1108 * desc->lock Provides serialization against hard interrupts
1110 * chip_bus_lock and desc->lock are sufficient for all other management and
1111 * interrupt related functions. desc->request_mutex solely serializes
1112 * request/free_irq().
1115 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1117 struct irqaction *old, **old_ptr;
1118 unsigned long flags, thread_mask = 0;
1119 int ret, nested, shared = 0;
1124 if (desc->irq_data.chip == &no_irq_chip)
1126 if (!try_module_get(desc->owner))
1132 * If the trigger type is not specified by the caller,
1133 * then use the default for this interrupt.
1135 if (!(new->flags & IRQF_TRIGGER_MASK))
1136 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1139 * Check whether the interrupt nests into another interrupt
1142 nested = irq_settings_is_nested_thread(desc);
1144 if (!new->thread_fn) {
1149 * Replace the primary handler which was provided from
1150 * the driver for non nested interrupt handling by the
1151 * dummy function which warns when called.
1153 new->handler = irq_nested_primary_handler;
1155 if (irq_settings_can_thread(desc)) {
1156 ret = irq_setup_forced_threading(new);
1163 * Create a handler thread when a thread function is supplied
1164 * and the interrupt does not nest into another interrupt
1167 if (new->thread_fn && !nested) {
1168 ret = setup_irq_thread(new, irq, false);
1171 if (new->secondary) {
1172 ret = setup_irq_thread(new->secondary, irq, true);
1179 * Drivers are often written to work w/o knowledge about the
1180 * underlying irq chip implementation, so a request for a
1181 * threaded irq without a primary hard irq context handler
1182 * requires the ONESHOT flag to be set. Some irq chips like
1183 * MSI based interrupts are per se one shot safe. Check the
1184 * chip flags, so we can avoid the unmask dance at the end of
1185 * the threaded handler for those.
1187 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1188 new->flags &= ~IRQF_ONESHOT;
1191 * Protects against a concurrent __free_irq() call which might wait
1192 * for synchronize_irq() to complete without holding the optional
1193 * chip bus lock and desc->lock.
1195 mutex_lock(&desc->request_mutex);
1198 * Acquire bus lock as the irq_request_resources() callback below
1199 * might rely on the serialization or the magic power management
1200 * functions which are abusing the irq_bus_lock() callback,
1202 chip_bus_lock(desc);
1204 /* First installed action requests resources. */
1205 if (!desc->action) {
1206 ret = irq_request_resources(desc);
1208 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1209 new->name, irq, desc->irq_data.chip->name);
1210 goto out_bus_unlock;
1215 * The following block of code has to be executed atomically
1216 * protected against a concurrent interrupt and any of the other
1217 * management calls which are not serialized via
1218 * desc->request_mutex or the optional bus lock.
1220 raw_spin_lock_irqsave(&desc->lock, flags);
1221 old_ptr = &desc->action;
1225 * Can't share interrupts unless both agree to and are
1226 * the same type (level, edge, polarity). So both flag
1227 * fields must have IRQF_SHARED set and the bits which
1228 * set the trigger type must match. Also all must
1231 unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);
1233 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1234 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1235 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1238 /* All handlers must agree on per-cpuness */
1239 if ((old->flags & IRQF_PERCPU) !=
1240 (new->flags & IRQF_PERCPU))
1243 /* add new interrupt at end of irq queue */
1246 * Or all existing action->thread_mask bits,
1247 * so we can find the next zero bit for this
1250 thread_mask |= old->thread_mask;
1251 old_ptr = &old->next;
1258 * Setup the thread mask for this irqaction for ONESHOT. For
1259 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1260 * conditional in irq_wake_thread().
1262 if (new->flags & IRQF_ONESHOT) {
1264 * Unlikely to have 32 resp 64 irqs sharing one line,
1267 if (thread_mask == ~0UL) {
1272 * The thread_mask for the action is or'ed to
1273 * desc->thread_active to indicate that the
1274 * IRQF_ONESHOT thread handler has been woken, but not
1275 * yet finished. The bit is cleared when a thread
1276 * completes. When all threads of a shared interrupt
1277 * line have completed desc->threads_active becomes
1278 * zero and the interrupt line is unmasked. See
1279 * handle.c:irq_wake_thread() for further information.
1281 * If no thread is woken by primary (hard irq context)
1282 * interrupt handlers, then desc->threads_active is
1283 * also checked for zero to unmask the irq line in the
1284 * affected hard irq flow handlers
1285 * (handle_[fasteoi|level]_irq).
1287 * The new action gets the first zero bit of
1288 * thread_mask assigned. See the loop above which or's
1289 * all existing action->thread_mask bits.
1291 new->thread_mask = 1 << ffz(thread_mask);
1293 } else if (new->handler == irq_default_primary_handler &&
1294 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1296 * The interrupt was requested with handler = NULL, so
1297 * we use the default primary handler for it. But it
1298 * does not have the oneshot flag set. In combination
1299 * with level interrupts this is deadly, because the
1300 * default primary handler just wakes the thread, then
1301 * the irq lines is reenabled, but the device still
1302 * has the level irq asserted. Rinse and repeat....
1304 * While this works for edge type interrupts, we play
1305 * it safe and reject unconditionally because we can't
1306 * say for sure which type this interrupt really
1307 * has. The type flags are unreliable as the
1308 * underlying chip implementation can override them.
1310 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1317 init_waitqueue_head(&desc->wait_for_threads);
1319 /* Setup the type (level, edge polarity) if configured: */
1320 if (new->flags & IRQF_TRIGGER_MASK) {
1321 ret = __irq_set_trigger(desc,
1322 new->flags & IRQF_TRIGGER_MASK);
1328 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1329 IRQS_ONESHOT | IRQS_WAITING);
1330 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1332 if (new->flags & IRQF_PERCPU) {
1333 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1334 irq_settings_set_per_cpu(desc);
1337 if (new->flags & IRQF_ONESHOT)
1338 desc->istate |= IRQS_ONESHOT;
1340 /* Exclude IRQ from balancing if requested */
1341 if (new->flags & IRQF_NOBALANCING) {
1342 irq_settings_set_no_balancing(desc);
1343 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1346 if (irq_settings_can_autoenable(desc)) {
1347 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1350 * Shared interrupts do not go well with disabling
1351 * auto enable. The sharing interrupt might request
1352 * it while it's still disabled and then wait for
1353 * interrupts forever.
1355 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1356 /* Undo nested disables: */
1360 } else if (new->flags & IRQF_TRIGGER_MASK) {
1361 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1362 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1365 /* hope the handler works with current trigger mode */
1366 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1372 irq_pm_install_action(desc, new);
1374 /* Reset broken irq detection when installing new handler */
1375 desc->irq_count = 0;
1376 desc->irqs_unhandled = 0;
1379 * Check whether we disabled the irq via the spurious handler
1380 * before. Reenable it and give it another chance.
1382 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1383 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1387 raw_spin_unlock_irqrestore(&desc->lock, flags);
1388 chip_bus_sync_unlock(desc);
1389 mutex_unlock(&desc->request_mutex);
1391 irq_setup_timings(desc, new);
1394 * Strictly no need to wake it up, but hung_task complains
1395 * when no hard interrupt wakes the thread up.
1398 wake_up_process(new->thread);
1400 wake_up_process(new->secondary->thread);
1402 register_irq_proc(irq, desc);
1403 irq_add_debugfs_entry(irq, desc);
1405 register_handler_proc(irq, new);
1409 if (!(new->flags & IRQF_PROBE_SHARED)) {
1410 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1411 irq, new->flags, new->name, old->flags, old->name);
1412 #ifdef CONFIG_DEBUG_SHIRQ
1419 raw_spin_unlock_irqrestore(&desc->lock, flags);
1422 irq_release_resources(desc);
1424 chip_bus_sync_unlock(desc);
1425 mutex_unlock(&desc->request_mutex);
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 retval = __setup_irq(irq, desc, act);
1469 irq_chip_pm_put(&desc->irq_data);
1473 EXPORT_SYMBOL_GPL(setup_irq);
1476 * Internal function to unregister an irqaction - used to free
1477 * regular and special interrupts that are part of the architecture.
1479 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1481 struct irq_desc *desc = irq_to_desc(irq);
1482 struct irqaction *action, **action_ptr;
1483 unsigned long flags;
1485 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1490 mutex_lock(&desc->request_mutex);
1491 chip_bus_lock(desc);
1492 raw_spin_lock_irqsave(&desc->lock, flags);
1495 * There can be multiple actions per IRQ descriptor, find the right
1496 * one based on the dev_id:
1498 action_ptr = &desc->action;
1500 action = *action_ptr;
1503 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1504 raw_spin_unlock_irqrestore(&desc->lock, flags);
1505 chip_bus_sync_unlock(desc);
1506 mutex_unlock(&desc->request_mutex);
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);
1527 /* make sure affinity_hint is cleaned up */
1528 if (WARN_ON_ONCE(desc->affinity_hint))
1529 desc->affinity_hint = NULL;
1532 raw_spin_unlock_irqrestore(&desc->lock, flags);
1534 * Drop bus_lock here so the changes which were done in the chip
1535 * callbacks above are synced out to the irq chips which hang
1536 * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1538 * Aside of that the bus_lock can also be taken from the threaded
1539 * handler in irq_finalize_oneshot() which results in a deadlock
1540 * because synchronize_irq() would wait forever for the thread to
1541 * complete, which is blocked on the bus lock.
1543 * The still held desc->request_mutex() protects against a
1544 * concurrent request_irq() of this irq so the release of resources
1545 * and timing data is properly serialized.
1547 chip_bus_sync_unlock(desc);
1549 unregister_handler_proc(irq, action);
1551 /* Make sure it's not being used on another CPU: */
1552 synchronize_irq(irq);
1554 #ifdef CONFIG_DEBUG_SHIRQ
1556 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1557 * event to happen even now it's being freed, so let's make sure that
1558 * is so by doing an extra call to the handler ....
1560 * ( We do this after actually deregistering it, to make sure that a
1561 * 'real' IRQ doesn't run in * parallel with our fake. )
1563 if (action->flags & IRQF_SHARED) {
1564 local_irq_save(flags);
1565 action->handler(irq, dev_id);
1566 local_irq_restore(flags);
1570 if (action->thread) {
1571 kthread_stop(action->thread);
1572 put_task_struct(action->thread);
1573 if (action->secondary && action->secondary->thread) {
1574 kthread_stop(action->secondary->thread);
1575 put_task_struct(action->secondary->thread);
1579 /* Last action releases resources */
1580 if (!desc->action) {
1582 * Reaquire bus lock as irq_release_resources() might
1583 * require it to deallocate resources over the slow bus.
1585 chip_bus_lock(desc);
1586 irq_release_resources(desc);
1587 chip_bus_sync_unlock(desc);
1588 irq_remove_timings(desc);
1591 mutex_unlock(&desc->request_mutex);
1593 irq_chip_pm_put(&desc->irq_data);
1594 module_put(desc->owner);
1595 kfree(action->secondary);
1600 * remove_irq - free an interrupt
1601 * @irq: Interrupt line to free
1602 * @act: irqaction for the interrupt
1604 * Used to remove interrupts statically setup by the early boot process.
1606 void remove_irq(unsigned int irq, struct irqaction *act)
1608 struct irq_desc *desc = irq_to_desc(irq);
1610 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1611 __free_irq(irq, act->dev_id);
1613 EXPORT_SYMBOL_GPL(remove_irq);
1616 * free_irq - free an interrupt allocated with request_irq
1617 * @irq: Interrupt line to free
1618 * @dev_id: Device identity to free
1620 * Remove an interrupt handler. The handler is removed and if the
1621 * interrupt line is no longer in use by any driver it is disabled.
1622 * On a shared IRQ the caller must ensure the interrupt is disabled
1623 * on the card it drives before calling this function. The function
1624 * does not return until any executing interrupts for this IRQ
1627 * This function must not be called from interrupt context.
1629 * Returns the devname argument passed to request_irq.
1631 const void *free_irq(unsigned int irq, void *dev_id)
1633 struct irq_desc *desc = irq_to_desc(irq);
1634 struct irqaction *action;
1635 const char *devname;
1637 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1641 if (WARN_ON(desc->affinity_notify))
1642 desc->affinity_notify = NULL;
1645 action = __free_irq(irq, dev_id);
1646 devname = action->name;
1650 EXPORT_SYMBOL(free_irq);
1653 * request_threaded_irq - allocate an interrupt line
1654 * @irq: Interrupt line to allocate
1655 * @handler: Function to be called when the IRQ occurs.
1656 * Primary handler for threaded interrupts
1657 * If NULL and thread_fn != NULL the default
1658 * primary handler is installed
1659 * @thread_fn: Function called from the irq handler thread
1660 * If NULL, no irq thread is created
1661 * @irqflags: Interrupt type flags
1662 * @devname: An ascii name for the claiming device
1663 * @dev_id: A cookie passed back to the handler function
1665 * This call allocates interrupt resources and enables the
1666 * interrupt line and IRQ handling. From the point this
1667 * call is made your handler function may be invoked. Since
1668 * your handler function must clear any interrupt the board
1669 * raises, you must take care both to initialise your hardware
1670 * and to set up the interrupt handler in the right order.
1672 * If you want to set up a threaded irq handler for your device
1673 * then you need to supply @handler and @thread_fn. @handler is
1674 * still called in hard interrupt context and has to check
1675 * whether the interrupt originates from the device. If yes it
1676 * needs to disable the interrupt on the device and return
1677 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1678 * @thread_fn. This split handler design is necessary to support
1679 * shared interrupts.
1681 * Dev_id must be globally unique. Normally the address of the
1682 * device data structure is used as the cookie. Since the handler
1683 * receives this value it makes sense to use it.
1685 * If your interrupt is shared you must pass a non NULL dev_id
1686 * as this is required when freeing the interrupt.
1690 * IRQF_SHARED Interrupt is shared
1691 * IRQF_TRIGGER_* Specify active edge(s) or level
1694 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1695 irq_handler_t thread_fn, unsigned long irqflags,
1696 const char *devname, void *dev_id)
1698 struct irqaction *action;
1699 struct irq_desc *desc;
1702 if (irq == IRQ_NOTCONNECTED)
1706 * Sanity-check: shared interrupts must pass in a real dev-ID,
1707 * otherwise we'll have trouble later trying to figure out
1708 * which interrupt is which (messes up the interrupt freeing
1711 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1712 * it cannot be set along with IRQF_NO_SUSPEND.
1714 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1715 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1716 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1719 desc = irq_to_desc(irq);
1723 if (!irq_settings_can_request(desc) ||
1724 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1730 handler = irq_default_primary_handler;
1733 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1737 action->handler = handler;
1738 action->thread_fn = thread_fn;
1739 action->flags = irqflags;
1740 action->name = devname;
1741 action->dev_id = dev_id;
1743 retval = irq_chip_pm_get(&desc->irq_data);
1749 retval = __setup_irq(irq, desc, action);
1752 irq_chip_pm_put(&desc->irq_data);
1753 kfree(action->secondary);
1757 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1758 if (!retval && (irqflags & IRQF_SHARED)) {
1760 * It's a shared IRQ -- the driver ought to be prepared for it
1761 * to happen immediately, so let's make sure....
1762 * We disable the irq to make sure that a 'real' IRQ doesn't
1763 * run in parallel with our fake.
1765 unsigned long flags;
1768 local_irq_save(flags);
1770 handler(irq, dev_id);
1772 local_irq_restore(flags);
1778 EXPORT_SYMBOL(request_threaded_irq);
1781 * request_any_context_irq - allocate an interrupt line
1782 * @irq: Interrupt line to allocate
1783 * @handler: Function to be called when the IRQ occurs.
1784 * Threaded handler for threaded interrupts.
1785 * @flags: Interrupt type flags
1786 * @name: An ascii name for the claiming device
1787 * @dev_id: A cookie passed back to the handler function
1789 * This call allocates interrupt resources and enables the
1790 * interrupt line and IRQ handling. It selects either a
1791 * hardirq or threaded handling method depending on the
1794 * On failure, it returns a negative value. On success,
1795 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1797 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1798 unsigned long flags, const char *name, void *dev_id)
1800 struct irq_desc *desc;
1803 if (irq == IRQ_NOTCONNECTED)
1806 desc = irq_to_desc(irq);
1810 if (irq_settings_is_nested_thread(desc)) {
1811 ret = request_threaded_irq(irq, NULL, handler,
1812 flags, name, dev_id);
1813 return !ret ? IRQC_IS_NESTED : ret;
1816 ret = request_irq(irq, handler, flags, name, dev_id);
1817 return !ret ? IRQC_IS_HARDIRQ : ret;
1819 EXPORT_SYMBOL_GPL(request_any_context_irq);
1821 void enable_percpu_irq(unsigned int irq, unsigned int type)
1823 unsigned int cpu = smp_processor_id();
1824 unsigned long flags;
1825 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1831 * If the trigger type is not specified by the caller, then
1832 * use the default for this interrupt.
1834 type &= IRQ_TYPE_SENSE_MASK;
1835 if (type == IRQ_TYPE_NONE)
1836 type = irqd_get_trigger_type(&desc->irq_data);
1838 if (type != IRQ_TYPE_NONE) {
1841 ret = __irq_set_trigger(desc, type);
1844 WARN(1, "failed to set type for IRQ%d\n", irq);
1849 irq_percpu_enable(desc, cpu);
1851 irq_put_desc_unlock(desc, flags);
1853 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1856 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1857 * @irq: Linux irq number to check for
1859 * Must be called from a non migratable context. Returns the enable
1860 * state of a per cpu interrupt on the current cpu.
1862 bool irq_percpu_is_enabled(unsigned int irq)
1864 unsigned int cpu = smp_processor_id();
1865 struct irq_desc *desc;
1866 unsigned long flags;
1869 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1873 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1874 irq_put_desc_unlock(desc, flags);
1878 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1880 void disable_percpu_irq(unsigned int irq)
1882 unsigned int cpu = smp_processor_id();
1883 unsigned long flags;
1884 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1889 irq_percpu_disable(desc, cpu);
1890 irq_put_desc_unlock(desc, flags);
1892 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1895 * Internal function to unregister a percpu irqaction.
1897 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1899 struct irq_desc *desc = irq_to_desc(irq);
1900 struct irqaction *action;
1901 unsigned long flags;
1903 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1908 raw_spin_lock_irqsave(&desc->lock, flags);
1910 action = desc->action;
1911 if (!action || action->percpu_dev_id != dev_id) {
1912 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1916 if (!cpumask_empty(desc->percpu_enabled)) {
1917 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1918 irq, cpumask_first(desc->percpu_enabled));
1922 /* Found it - now remove it from the list of entries: */
1923 desc->action = NULL;
1925 raw_spin_unlock_irqrestore(&desc->lock, flags);
1927 unregister_handler_proc(irq, action);
1929 irq_chip_pm_put(&desc->irq_data);
1930 module_put(desc->owner);
1934 raw_spin_unlock_irqrestore(&desc->lock, flags);
1939 * remove_percpu_irq - free a per-cpu interrupt
1940 * @irq: Interrupt line to free
1941 * @act: irqaction for the interrupt
1943 * Used to remove interrupts statically setup by the early boot process.
1945 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1947 struct irq_desc *desc = irq_to_desc(irq);
1949 if (desc && irq_settings_is_per_cpu_devid(desc))
1950 __free_percpu_irq(irq, act->percpu_dev_id);
1954 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1955 * @irq: Interrupt line to free
1956 * @dev_id: Device identity to free
1958 * Remove a percpu interrupt handler. The handler is removed, but
1959 * the interrupt line is not disabled. This must be done on each
1960 * CPU before calling this function. The function does not return
1961 * until any executing interrupts for this IRQ have completed.
1963 * This function must not be called from interrupt context.
1965 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1967 struct irq_desc *desc = irq_to_desc(irq);
1969 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1972 chip_bus_lock(desc);
1973 kfree(__free_percpu_irq(irq, dev_id));
1974 chip_bus_sync_unlock(desc);
1976 EXPORT_SYMBOL_GPL(free_percpu_irq);
1979 * setup_percpu_irq - setup a per-cpu interrupt
1980 * @irq: Interrupt line to setup
1981 * @act: irqaction for the interrupt
1983 * Used to statically setup per-cpu interrupts in the early boot process.
1985 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1987 struct irq_desc *desc = irq_to_desc(irq);
1990 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1993 retval = irq_chip_pm_get(&desc->irq_data);
1997 retval = __setup_irq(irq, desc, act);
2000 irq_chip_pm_put(&desc->irq_data);
2006 * __request_percpu_irq - allocate a percpu interrupt line
2007 * @irq: Interrupt line to allocate
2008 * @handler: Function to be called when the IRQ occurs.
2009 * @flags: Interrupt type flags (IRQF_TIMER only)
2010 * @devname: An ascii name for the claiming device
2011 * @dev_id: A percpu cookie passed back to the handler function
2013 * This call allocates interrupt resources and enables the
2014 * interrupt on the local CPU. If the interrupt is supposed to be
2015 * enabled on other CPUs, it has to be done on each CPU using
2016 * enable_percpu_irq().
2018 * Dev_id must be globally unique. It is a per-cpu variable, and
2019 * the handler gets called with the interrupted CPU's instance of
2022 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2023 unsigned long flags, const char *devname,
2024 void __percpu *dev_id)
2026 struct irqaction *action;
2027 struct irq_desc *desc;
2033 desc = irq_to_desc(irq);
2034 if (!desc || !irq_settings_can_request(desc) ||
2035 !irq_settings_is_per_cpu_devid(desc))
2038 if (flags && flags != IRQF_TIMER)
2041 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2045 action->handler = handler;
2046 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2047 action->name = devname;
2048 action->percpu_dev_id = dev_id;
2050 retval = irq_chip_pm_get(&desc->irq_data);
2056 retval = __setup_irq(irq, desc, action);
2059 irq_chip_pm_put(&desc->irq_data);
2065 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2068 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2069 * @irq: Interrupt line that is forwarded to a VM
2070 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2071 * @state: a pointer to a boolean where the state is to be storeed
2073 * This call snapshots the internal irqchip state of an
2074 * interrupt, returning into @state the bit corresponding to
2077 * This function should be called with preemption disabled if the
2078 * interrupt controller has per-cpu registers.
2080 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2083 struct irq_desc *desc;
2084 struct irq_data *data;
2085 struct irq_chip *chip;
2086 unsigned long flags;
2089 desc = irq_get_desc_buslock(irq, &flags, 0);
2093 data = irq_desc_get_irq_data(desc);
2096 chip = irq_data_get_irq_chip(data);
2097 if (chip->irq_get_irqchip_state)
2099 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2100 data = data->parent_data;
2107 err = chip->irq_get_irqchip_state(data, which, state);
2109 irq_put_desc_busunlock(desc, flags);
2112 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2115 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2116 * @irq: Interrupt line that is forwarded to a VM
2117 * @which: State to be restored (one of IRQCHIP_STATE_*)
2118 * @val: Value corresponding to @which
2120 * This call sets the internal irqchip state of an interrupt,
2121 * depending on the value of @which.
2123 * This function should be called with preemption disabled if the
2124 * interrupt controller has per-cpu registers.
2126 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2129 struct irq_desc *desc;
2130 struct irq_data *data;
2131 struct irq_chip *chip;
2132 unsigned long flags;
2135 desc = irq_get_desc_buslock(irq, &flags, 0);
2139 data = irq_desc_get_irq_data(desc);
2142 chip = irq_data_get_irq_chip(data);
2143 if (chip->irq_set_irqchip_state)
2145 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2146 data = data->parent_data;
2153 err = chip->irq_set_irqchip_state(data, which, val);
2155 irq_put_desc_busunlock(desc, flags);
2158 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);