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);
403 chip = irq_data_get_irq_chip(data);
404 if (chip && chip->irq_set_vcpu_affinity)
405 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
406 irq_put_desc_unlock(desc, flags);
410 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
412 void __disable_irq(struct irq_desc *desc)
418 static int __disable_irq_nosync(unsigned int irq)
421 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
426 irq_put_desc_busunlock(desc, flags);
431 * disable_irq_nosync - disable an irq without waiting
432 * @irq: Interrupt to disable
434 * Disable the selected interrupt line. Disables and Enables are
436 * Unlike disable_irq(), this function does not ensure existing
437 * instances of the IRQ handler have completed before returning.
439 * This function may be called from IRQ context.
441 void disable_irq_nosync(unsigned int irq)
443 __disable_irq_nosync(irq);
445 EXPORT_SYMBOL(disable_irq_nosync);
448 * disable_irq - disable an irq and wait for completion
449 * @irq: Interrupt to disable
451 * Disable the selected interrupt line. Enables and Disables are
453 * This function waits for any pending IRQ handlers for this interrupt
454 * to complete before returning. If you use this function while
455 * holding a resource the IRQ handler may need you will deadlock.
457 * This function may be called - with care - from IRQ context.
459 void disable_irq(unsigned int irq)
461 if (!__disable_irq_nosync(irq))
462 synchronize_irq(irq);
464 EXPORT_SYMBOL(disable_irq);
467 * disable_hardirq - disables an irq and waits for hardirq completion
468 * @irq: Interrupt to disable
470 * Disable the selected interrupt line. Enables and Disables are
472 * This function waits for any pending hard IRQ handlers for this
473 * interrupt to complete before returning. If you use this function while
474 * holding a resource the hard IRQ handler may need you will deadlock.
476 * When used to optimistically disable an interrupt from atomic context
477 * the return value must be checked.
479 * Returns: false if a threaded handler is active.
481 * This function may be called - with care - from IRQ context.
483 bool disable_hardirq(unsigned int irq)
485 if (!__disable_irq_nosync(irq))
486 return synchronize_hardirq(irq);
490 EXPORT_SYMBOL_GPL(disable_hardirq);
492 void __enable_irq(struct irq_desc *desc)
494 switch (desc->depth) {
497 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
498 irq_desc_get_irq(desc));
501 if (desc->istate & IRQS_SUSPENDED)
503 /* Prevent probing on this irq: */
504 irq_settings_set_noprobe(desc);
506 * Call irq_startup() not irq_enable() here because the
507 * interrupt might be marked NOAUTOEN. So irq_startup()
508 * needs to be invoked when it gets enabled the first
509 * time. If it was already started up, then irq_startup()
510 * will invoke irq_enable() under the hood.
512 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
521 * enable_irq - enable handling of an irq
522 * @irq: Interrupt to enable
524 * Undoes the effect of one call to disable_irq(). If this
525 * matches the last disable, processing of interrupts on this
526 * IRQ line is re-enabled.
528 * This function may be called from IRQ context only when
529 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
531 void enable_irq(unsigned int irq)
534 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
538 if (WARN(!desc->irq_data.chip,
539 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
544 irq_put_desc_busunlock(desc, flags);
546 EXPORT_SYMBOL(enable_irq);
548 static int set_irq_wake_real(unsigned int irq, unsigned int on)
550 struct irq_desc *desc = irq_to_desc(irq);
553 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
556 if (desc->irq_data.chip->irq_set_wake)
557 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
563 * irq_set_irq_wake - control irq power management wakeup
564 * @irq: interrupt to control
565 * @on: enable/disable power management wakeup
567 * Enable/disable power management wakeup mode, which is
568 * disabled by default. Enables and disables must match,
569 * just as they match for non-wakeup mode support.
571 * Wakeup mode lets this IRQ wake the system from sleep
572 * states like "suspend to RAM".
574 int irq_set_irq_wake(unsigned int irq, unsigned int on)
577 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
583 /* wakeup-capable irqs can be shared between drivers that
584 * don't need to have the same sleep mode behaviors.
587 if (desc->wake_depth++ == 0) {
588 ret = set_irq_wake_real(irq, on);
590 desc->wake_depth = 0;
592 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
595 if (desc->wake_depth == 0) {
596 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
597 } else if (--desc->wake_depth == 0) {
598 ret = set_irq_wake_real(irq, on);
600 desc->wake_depth = 1;
602 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
605 irq_put_desc_busunlock(desc, flags);
608 EXPORT_SYMBOL(irq_set_irq_wake);
611 * Internal function that tells the architecture code whether a
612 * particular irq has been exclusively allocated or is available
615 int can_request_irq(unsigned int irq, unsigned long irqflags)
618 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
624 if (irq_settings_can_request(desc)) {
626 irqflags & desc->action->flags & IRQF_SHARED)
629 irq_put_desc_unlock(desc, flags);
633 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
635 struct irq_chip *chip = desc->irq_data.chip;
638 if (!chip || !chip->irq_set_type) {
640 * IRQF_TRIGGER_* but the PIC does not support multiple
643 pr_debug("No set_type function for IRQ %d (%s)\n",
644 irq_desc_get_irq(desc),
645 chip ? (chip->name ? : "unknown") : "unknown");
649 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
650 if (!irqd_irq_masked(&desc->irq_data))
652 if (!irqd_irq_disabled(&desc->irq_data))
656 /* Mask all flags except trigger mode */
657 flags &= IRQ_TYPE_SENSE_MASK;
658 ret = chip->irq_set_type(&desc->irq_data, flags);
661 case IRQ_SET_MASK_OK:
662 case IRQ_SET_MASK_OK_DONE:
663 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
664 irqd_set(&desc->irq_data, flags);
666 case IRQ_SET_MASK_OK_NOCOPY:
667 flags = irqd_get_trigger_type(&desc->irq_data);
668 irq_settings_set_trigger_mask(desc, flags);
669 irqd_clear(&desc->irq_data, IRQD_LEVEL);
670 irq_settings_clr_level(desc);
671 if (flags & IRQ_TYPE_LEVEL_MASK) {
672 irq_settings_set_level(desc);
673 irqd_set(&desc->irq_data, IRQD_LEVEL);
679 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
680 flags, irq_desc_get_irq(desc), chip->irq_set_type);
687 #ifdef CONFIG_HARDIRQS_SW_RESEND
688 int irq_set_parent(int irq, int parent_irq)
691 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
696 desc->parent_irq = parent_irq;
698 irq_put_desc_unlock(desc, flags);
701 EXPORT_SYMBOL_GPL(irq_set_parent);
705 * Default primary interrupt handler for threaded interrupts. Is
706 * assigned as primary handler when request_threaded_irq is called
707 * with handler == NULL. Useful for oneshot interrupts.
709 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
711 return IRQ_WAKE_THREAD;
715 * Primary handler for nested threaded interrupts. Should never be
718 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
720 WARN(1, "Primary handler called for nested irq %d\n", irq);
724 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
726 WARN(1, "Secondary action handler called for irq %d\n", irq);
730 static int irq_wait_for_interrupt(struct irqaction *action)
732 set_current_state(TASK_INTERRUPTIBLE);
734 while (!kthread_should_stop()) {
736 if (test_and_clear_bit(IRQTF_RUNTHREAD,
737 &action->thread_flags)) {
738 __set_current_state(TASK_RUNNING);
742 set_current_state(TASK_INTERRUPTIBLE);
744 __set_current_state(TASK_RUNNING);
749 * Oneshot interrupts keep the irq line masked until the threaded
750 * handler finished. unmask if the interrupt has not been disabled and
753 static void irq_finalize_oneshot(struct irq_desc *desc,
754 struct irqaction *action)
756 if (!(desc->istate & IRQS_ONESHOT) ||
757 action->handler == irq_forced_secondary_handler)
761 raw_spin_lock_irq(&desc->lock);
764 * Implausible though it may be we need to protect us against
765 * the following scenario:
767 * The thread is faster done than the hard interrupt handler
768 * on the other CPU. If we unmask the irq line then the
769 * interrupt can come in again and masks the line, leaves due
770 * to IRQS_INPROGRESS and the irq line is masked forever.
772 * This also serializes the state of shared oneshot handlers
773 * versus "desc->threads_onehsot |= action->thread_mask;" in
774 * irq_wake_thread(). See the comment there which explains the
777 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
778 raw_spin_unlock_irq(&desc->lock);
779 chip_bus_sync_unlock(desc);
785 * Now check again, whether the thread should run. Otherwise
786 * we would clear the threads_oneshot bit of this thread which
789 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
792 desc->threads_oneshot &= ~action->thread_mask;
794 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
795 irqd_irq_masked(&desc->irq_data))
796 unmask_threaded_irq(desc);
799 raw_spin_unlock_irq(&desc->lock);
800 chip_bus_sync_unlock(desc);
805 * Check whether we need to change the affinity of the interrupt thread.
808 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
813 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
817 * In case we are out of memory we set IRQTF_AFFINITY again and
818 * try again next time
820 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
821 set_bit(IRQTF_AFFINITY, &action->thread_flags);
825 raw_spin_lock_irq(&desc->lock);
827 * This code is triggered unconditionally. Check the affinity
828 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
830 if (cpumask_available(desc->irq_common_data.affinity))
831 cpumask_copy(mask, desc->irq_common_data.affinity);
834 raw_spin_unlock_irq(&desc->lock);
837 set_cpus_allowed_ptr(current, mask);
838 free_cpumask_var(mask);
842 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
846 * Interrupts which are not explicitely requested as threaded
847 * interrupts rely on the implicit bh/preempt disable of the hard irq
848 * context. So we need to disable bh here to avoid deadlocks and other
852 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
857 ret = action->thread_fn(action->irq, action->dev_id);
858 irq_finalize_oneshot(desc, action);
864 * Interrupts explicitly requested as threaded interrupts want to be
865 * preemtible - many of them need to sleep and wait for slow busses to
868 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
869 struct irqaction *action)
873 ret = action->thread_fn(action->irq, action->dev_id);
874 irq_finalize_oneshot(desc, action);
878 static void wake_threads_waitq(struct irq_desc *desc)
880 if (atomic_dec_and_test(&desc->threads_active))
881 wake_up(&desc->wait_for_threads);
884 static void irq_thread_dtor(struct callback_head *unused)
886 struct task_struct *tsk = current;
887 struct irq_desc *desc;
888 struct irqaction *action;
890 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
893 action = kthread_data(tsk);
895 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
896 tsk->comm, tsk->pid, action->irq);
899 desc = irq_to_desc(action->irq);
901 * If IRQTF_RUNTHREAD is set, we need to decrement
902 * desc->threads_active and wake possible waiters.
904 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
905 wake_threads_waitq(desc);
907 /* Prevent a stale desc->threads_oneshot */
908 irq_finalize_oneshot(desc, action);
911 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
913 struct irqaction *secondary = action->secondary;
915 if (WARN_ON_ONCE(!secondary))
918 raw_spin_lock_irq(&desc->lock);
919 __irq_wake_thread(desc, secondary);
920 raw_spin_unlock_irq(&desc->lock);
924 * Interrupt handler thread
926 static int irq_thread(void *data)
928 struct callback_head on_exit_work;
929 struct irqaction *action = data;
930 struct irq_desc *desc = irq_to_desc(action->irq);
931 irqreturn_t (*handler_fn)(struct irq_desc *desc,
932 struct irqaction *action);
934 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
935 &action->thread_flags))
936 handler_fn = irq_forced_thread_fn;
938 handler_fn = irq_thread_fn;
940 init_task_work(&on_exit_work, irq_thread_dtor);
941 task_work_add(current, &on_exit_work, false);
943 irq_thread_check_affinity(desc, action);
945 while (!irq_wait_for_interrupt(action)) {
946 irqreturn_t action_ret;
948 irq_thread_check_affinity(desc, action);
950 action_ret = handler_fn(desc, action);
951 if (action_ret == IRQ_HANDLED)
952 atomic_inc(&desc->threads_handled);
953 if (action_ret == IRQ_WAKE_THREAD)
954 irq_wake_secondary(desc, action);
956 wake_threads_waitq(desc);
960 * This is the regular exit path. __free_irq() is stopping the
961 * thread via kthread_stop() after calling
962 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
963 * oneshot mask bit can be set. We cannot verify that as we
964 * cannot touch the oneshot mask at this point anymore as
965 * __setup_irq() might have given out currents thread_mask
968 task_work_cancel(current, irq_thread_dtor);
973 * irq_wake_thread - wake the irq thread for the action identified by dev_id
974 * @irq: Interrupt line
975 * @dev_id: Device identity for which the thread should be woken
978 void irq_wake_thread(unsigned int irq, void *dev_id)
980 struct irq_desc *desc = irq_to_desc(irq);
981 struct irqaction *action;
984 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
987 raw_spin_lock_irqsave(&desc->lock, flags);
988 for_each_action_of_desc(desc, action) {
989 if (action->dev_id == dev_id) {
991 __irq_wake_thread(desc, action);
995 raw_spin_unlock_irqrestore(&desc->lock, flags);
997 EXPORT_SYMBOL_GPL(irq_wake_thread);
999 static int irq_setup_forced_threading(struct irqaction *new)
1001 if (!force_irqthreads)
1003 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1006 new->flags |= IRQF_ONESHOT;
1009 * Handle the case where we have a real primary handler and a
1010 * thread handler. We force thread them as well by creating a
1013 if (new->handler != irq_default_primary_handler && new->thread_fn) {
1014 /* Allocate the secondary action */
1015 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1016 if (!new->secondary)
1018 new->secondary->handler = irq_forced_secondary_handler;
1019 new->secondary->thread_fn = new->thread_fn;
1020 new->secondary->dev_id = new->dev_id;
1021 new->secondary->irq = new->irq;
1022 new->secondary->name = new->name;
1024 /* Deal with the primary handler */
1025 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1026 new->thread_fn = new->handler;
1027 new->handler = irq_default_primary_handler;
1031 static int irq_request_resources(struct irq_desc *desc)
1033 struct irq_data *d = &desc->irq_data;
1034 struct irq_chip *c = d->chip;
1036 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1039 static void irq_release_resources(struct irq_desc *desc)
1041 struct irq_data *d = &desc->irq_data;
1042 struct irq_chip *c = d->chip;
1044 if (c->irq_release_resources)
1045 c->irq_release_resources(d);
1049 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1051 struct task_struct *t;
1052 struct sched_param param = {
1053 .sched_priority = MAX_USER_RT_PRIO/2,
1057 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1060 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1062 param.sched_priority -= 1;
1068 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1071 * We keep the reference to the task struct even if
1072 * the thread dies to avoid that the interrupt code
1073 * references an already freed task_struct.
1078 * Tell the thread to set its affinity. This is
1079 * important for shared interrupt handlers as we do
1080 * not invoke setup_affinity() for the secondary
1081 * handlers as everything is already set up. Even for
1082 * interrupts marked with IRQF_NO_BALANCE this is
1083 * correct as we want the thread to move to the cpu(s)
1084 * on which the requesting code placed the interrupt.
1086 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1091 * Internal function to register an irqaction - typically used to
1092 * allocate special interrupts that are part of the architecture.
1096 * desc->request_mutex Provides serialization against a concurrent free_irq()
1097 * chip_bus_lock Provides serialization for slow bus operations
1098 * desc->lock Provides serialization against hard interrupts
1100 * chip_bus_lock and desc->lock are sufficient for all other management and
1101 * interrupt related functions. desc->request_mutex solely serializes
1102 * request/free_irq().
1105 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1107 struct irqaction *old, **old_ptr;
1108 unsigned long flags, thread_mask = 0;
1109 int ret, nested, shared = 0;
1114 if (desc->irq_data.chip == &no_irq_chip)
1116 if (!try_module_get(desc->owner))
1122 * If the trigger type is not specified by the caller,
1123 * then use the default for this interrupt.
1125 if (!(new->flags & IRQF_TRIGGER_MASK))
1126 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1129 * Check whether the interrupt nests into another interrupt
1132 nested = irq_settings_is_nested_thread(desc);
1134 if (!new->thread_fn) {
1139 * Replace the primary handler which was provided from
1140 * the driver for non nested interrupt handling by the
1141 * dummy function which warns when called.
1143 new->handler = irq_nested_primary_handler;
1145 if (irq_settings_can_thread(desc)) {
1146 ret = irq_setup_forced_threading(new);
1153 * Create a handler thread when a thread function is supplied
1154 * and the interrupt does not nest into another interrupt
1157 if (new->thread_fn && !nested) {
1158 ret = setup_irq_thread(new, irq, false);
1161 if (new->secondary) {
1162 ret = setup_irq_thread(new->secondary, irq, true);
1169 * Drivers are often written to work w/o knowledge about the
1170 * underlying irq chip implementation, so a request for a
1171 * threaded irq without a primary hard irq context handler
1172 * requires the ONESHOT flag to be set. Some irq chips like
1173 * MSI based interrupts are per se one shot safe. Check the
1174 * chip flags, so we can avoid the unmask dance at the end of
1175 * the threaded handler for those.
1177 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1178 new->flags &= ~IRQF_ONESHOT;
1181 * Protects against a concurrent __free_irq() call which might wait
1182 * for synchronize_irq() to complete without holding the optional
1183 * chip bus lock and desc->lock.
1185 mutex_lock(&desc->request_mutex);
1188 * Acquire bus lock as the irq_request_resources() callback below
1189 * might rely on the serialization or the magic power management
1190 * functions which are abusing the irq_bus_lock() callback,
1192 chip_bus_lock(desc);
1194 /* First installed action requests resources. */
1195 if (!desc->action) {
1196 ret = irq_request_resources(desc);
1198 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1199 new->name, irq, desc->irq_data.chip->name);
1200 goto out_bus_unlock;
1205 * The following block of code has to be executed atomically
1206 * protected against a concurrent interrupt and any of the other
1207 * management calls which are not serialized via
1208 * desc->request_mutex or the optional bus lock.
1210 raw_spin_lock_irqsave(&desc->lock, flags);
1211 old_ptr = &desc->action;
1215 * Can't share interrupts unless both agree to and are
1216 * the same type (level, edge, polarity). So both flag
1217 * fields must have IRQF_SHARED set and the bits which
1218 * set the trigger type must match. Also all must
1221 unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);
1223 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1224 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1225 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1228 /* All handlers must agree on per-cpuness */
1229 if ((old->flags & IRQF_PERCPU) !=
1230 (new->flags & IRQF_PERCPU))
1233 /* add new interrupt at end of irq queue */
1236 * Or all existing action->thread_mask bits,
1237 * so we can find the next zero bit for this
1240 thread_mask |= old->thread_mask;
1241 old_ptr = &old->next;
1248 * Setup the thread mask for this irqaction for ONESHOT. For
1249 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1250 * conditional in irq_wake_thread().
1252 if (new->flags & IRQF_ONESHOT) {
1254 * Unlikely to have 32 resp 64 irqs sharing one line,
1257 if (thread_mask == ~0UL) {
1262 * The thread_mask for the action is or'ed to
1263 * desc->thread_active to indicate that the
1264 * IRQF_ONESHOT thread handler has been woken, but not
1265 * yet finished. The bit is cleared when a thread
1266 * completes. When all threads of a shared interrupt
1267 * line have completed desc->threads_active becomes
1268 * zero and the interrupt line is unmasked. See
1269 * handle.c:irq_wake_thread() for further information.
1271 * If no thread is woken by primary (hard irq context)
1272 * interrupt handlers, then desc->threads_active is
1273 * also checked for zero to unmask the irq line in the
1274 * affected hard irq flow handlers
1275 * (handle_[fasteoi|level]_irq).
1277 * The new action gets the first zero bit of
1278 * thread_mask assigned. See the loop above which or's
1279 * all existing action->thread_mask bits.
1281 new->thread_mask = 1 << ffz(thread_mask);
1283 } else if (new->handler == irq_default_primary_handler &&
1284 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1286 * The interrupt was requested with handler = NULL, so
1287 * we use the default primary handler for it. But it
1288 * does not have the oneshot flag set. In combination
1289 * with level interrupts this is deadly, because the
1290 * default primary handler just wakes the thread, then
1291 * the irq lines is reenabled, but the device still
1292 * has the level irq asserted. Rinse and repeat....
1294 * While this works for edge type interrupts, we play
1295 * it safe and reject unconditionally because we can't
1296 * say for sure which type this interrupt really
1297 * has. The type flags are unreliable as the
1298 * underlying chip implementation can override them.
1300 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1307 init_waitqueue_head(&desc->wait_for_threads);
1309 /* Setup the type (level, edge polarity) if configured: */
1310 if (new->flags & IRQF_TRIGGER_MASK) {
1311 ret = __irq_set_trigger(desc,
1312 new->flags & IRQF_TRIGGER_MASK);
1318 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1319 IRQS_ONESHOT | IRQS_WAITING);
1320 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1322 if (new->flags & IRQF_PERCPU) {
1323 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1324 irq_settings_set_per_cpu(desc);
1327 if (new->flags & IRQF_ONESHOT)
1328 desc->istate |= IRQS_ONESHOT;
1330 /* Exclude IRQ from balancing if requested */
1331 if (new->flags & IRQF_NOBALANCING) {
1332 irq_settings_set_no_balancing(desc);
1333 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1336 if (irq_settings_can_autoenable(desc)) {
1337 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1340 * Shared interrupts do not go well with disabling
1341 * auto enable. The sharing interrupt might request
1342 * it while it's still disabled and then wait for
1343 * interrupts forever.
1345 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1346 /* Undo nested disables: */
1350 } else if (new->flags & IRQF_TRIGGER_MASK) {
1351 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1352 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1355 /* hope the handler works with current trigger mode */
1356 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1362 irq_pm_install_action(desc, new);
1364 /* Reset broken irq detection when installing new handler */
1365 desc->irq_count = 0;
1366 desc->irqs_unhandled = 0;
1369 * Check whether we disabled the irq via the spurious handler
1370 * before. Reenable it and give it another chance.
1372 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1373 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1377 raw_spin_unlock_irqrestore(&desc->lock, flags);
1378 chip_bus_sync_unlock(desc);
1379 mutex_unlock(&desc->request_mutex);
1381 irq_setup_timings(desc, new);
1384 * Strictly no need to wake it up, but hung_task complains
1385 * when no hard interrupt wakes the thread up.
1388 wake_up_process(new->thread);
1390 wake_up_process(new->secondary->thread);
1392 register_irq_proc(irq, desc);
1393 irq_add_debugfs_entry(irq, desc);
1395 register_handler_proc(irq, new);
1399 if (!(new->flags & IRQF_PROBE_SHARED)) {
1400 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1401 irq, new->flags, new->name, old->flags, old->name);
1402 #ifdef CONFIG_DEBUG_SHIRQ
1409 raw_spin_unlock_irqrestore(&desc->lock, flags);
1412 irq_release_resources(desc);
1414 chip_bus_sync_unlock(desc);
1415 mutex_unlock(&desc->request_mutex);
1419 struct task_struct *t = new->thread;
1425 if (new->secondary && new->secondary->thread) {
1426 struct task_struct *t = new->secondary->thread;
1428 new->secondary->thread = NULL;
1433 module_put(desc->owner);
1438 * setup_irq - setup an interrupt
1439 * @irq: Interrupt line to setup
1440 * @act: irqaction for the interrupt
1442 * Used to statically setup interrupts in the early boot process.
1444 int setup_irq(unsigned int irq, struct irqaction *act)
1447 struct irq_desc *desc = irq_to_desc(irq);
1449 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1452 retval = irq_chip_pm_get(&desc->irq_data);
1456 retval = __setup_irq(irq, desc, act);
1459 irq_chip_pm_put(&desc->irq_data);
1463 EXPORT_SYMBOL_GPL(setup_irq);
1466 * Internal function to unregister an irqaction - used to free
1467 * regular and special interrupts that are part of the architecture.
1469 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1471 struct irq_desc *desc = irq_to_desc(irq);
1472 struct irqaction *action, **action_ptr;
1473 unsigned long flags;
1475 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1480 mutex_lock(&desc->request_mutex);
1481 chip_bus_lock(desc);
1482 raw_spin_lock_irqsave(&desc->lock, flags);
1485 * There can be multiple actions per IRQ descriptor, find the right
1486 * one based on the dev_id:
1488 action_ptr = &desc->action;
1490 action = *action_ptr;
1493 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1494 raw_spin_unlock_irqrestore(&desc->lock, flags);
1495 chip_bus_sync_unlock(desc);
1496 mutex_unlock(&desc->request_mutex);
1500 if (action->dev_id == dev_id)
1502 action_ptr = &action->next;
1505 /* Found it - now remove it from the list of entries: */
1506 *action_ptr = action->next;
1508 irq_pm_remove_action(desc, action);
1510 /* If this was the last handler, shut down the IRQ line: */
1511 if (!desc->action) {
1512 irq_settings_clr_disable_unlazy(desc);
1517 /* make sure affinity_hint is cleaned up */
1518 if (WARN_ON_ONCE(desc->affinity_hint))
1519 desc->affinity_hint = NULL;
1522 raw_spin_unlock_irqrestore(&desc->lock, flags);
1524 * Drop bus_lock here so the changes which were done in the chip
1525 * callbacks above are synced out to the irq chips which hang
1526 * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1528 * Aside of that the bus_lock can also be taken from the threaded
1529 * handler in irq_finalize_oneshot() which results in a deadlock
1530 * because synchronize_irq() would wait forever for the thread to
1531 * complete, which is blocked on the bus lock.
1533 * The still held desc->request_mutex() protects against a
1534 * concurrent request_irq() of this irq so the release of resources
1535 * and timing data is properly serialized.
1537 chip_bus_sync_unlock(desc);
1539 unregister_handler_proc(irq, action);
1541 /* Make sure it's not being used on another CPU: */
1542 synchronize_irq(irq);
1544 #ifdef CONFIG_DEBUG_SHIRQ
1546 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1547 * event to happen even now it's being freed, so let's make sure that
1548 * is so by doing an extra call to the handler ....
1550 * ( We do this after actually deregistering it, to make sure that a
1551 * 'real' IRQ doesn't run in * parallel with our fake. )
1553 if (action->flags & IRQF_SHARED) {
1554 local_irq_save(flags);
1555 action->handler(irq, dev_id);
1556 local_irq_restore(flags);
1560 if (action->thread) {
1561 kthread_stop(action->thread);
1562 put_task_struct(action->thread);
1563 if (action->secondary && action->secondary->thread) {
1564 kthread_stop(action->secondary->thread);
1565 put_task_struct(action->secondary->thread);
1569 /* Last action releases resources */
1570 if (!desc->action) {
1572 * Reaquire bus lock as irq_release_resources() might
1573 * require it to deallocate resources over the slow bus.
1575 chip_bus_lock(desc);
1576 irq_release_resources(desc);
1577 chip_bus_sync_unlock(desc);
1578 irq_remove_timings(desc);
1581 mutex_unlock(&desc->request_mutex);
1583 irq_chip_pm_put(&desc->irq_data);
1584 module_put(desc->owner);
1585 kfree(action->secondary);
1590 * remove_irq - free an interrupt
1591 * @irq: Interrupt line to free
1592 * @act: irqaction for the interrupt
1594 * Used to remove interrupts statically setup by the early boot process.
1596 void remove_irq(unsigned int irq, struct irqaction *act)
1598 struct irq_desc *desc = irq_to_desc(irq);
1600 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1601 __free_irq(irq, act->dev_id);
1603 EXPORT_SYMBOL_GPL(remove_irq);
1606 * free_irq - free an interrupt allocated with request_irq
1607 * @irq: Interrupt line to free
1608 * @dev_id: Device identity to free
1610 * Remove an interrupt handler. The handler is removed and if the
1611 * interrupt line is no longer in use by any driver it is disabled.
1612 * On a shared IRQ the caller must ensure the interrupt is disabled
1613 * on the card it drives before calling this function. The function
1614 * does not return until any executing interrupts for this IRQ
1617 * This function must not be called from interrupt context.
1619 * Returns the devname argument passed to request_irq.
1621 const void *free_irq(unsigned int irq, void *dev_id)
1623 struct irq_desc *desc = irq_to_desc(irq);
1624 struct irqaction *action;
1625 const char *devname;
1627 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1631 if (WARN_ON(desc->affinity_notify))
1632 desc->affinity_notify = NULL;
1635 action = __free_irq(irq, dev_id);
1636 devname = action->name;
1640 EXPORT_SYMBOL(free_irq);
1643 * request_threaded_irq - allocate an interrupt line
1644 * @irq: Interrupt line to allocate
1645 * @handler: Function to be called when the IRQ occurs.
1646 * Primary handler for threaded interrupts
1647 * If NULL and thread_fn != NULL the default
1648 * primary handler is installed
1649 * @thread_fn: Function called from the irq handler thread
1650 * If NULL, no irq thread is created
1651 * @irqflags: Interrupt type flags
1652 * @devname: An ascii name for the claiming device
1653 * @dev_id: A cookie passed back to the handler function
1655 * This call allocates interrupt resources and enables the
1656 * interrupt line and IRQ handling. From the point this
1657 * call is made your handler function may be invoked. Since
1658 * your handler function must clear any interrupt the board
1659 * raises, you must take care both to initialise your hardware
1660 * and to set up the interrupt handler in the right order.
1662 * If you want to set up a threaded irq handler for your device
1663 * then you need to supply @handler and @thread_fn. @handler is
1664 * still called in hard interrupt context and has to check
1665 * whether the interrupt originates from the device. If yes it
1666 * needs to disable the interrupt on the device and return
1667 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1668 * @thread_fn. This split handler design is necessary to support
1669 * shared interrupts.
1671 * Dev_id must be globally unique. Normally the address of the
1672 * device data structure is used as the cookie. Since the handler
1673 * receives this value it makes sense to use it.
1675 * If your interrupt is shared you must pass a non NULL dev_id
1676 * as this is required when freeing the interrupt.
1680 * IRQF_SHARED Interrupt is shared
1681 * IRQF_TRIGGER_* Specify active edge(s) or level
1684 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1685 irq_handler_t thread_fn, unsigned long irqflags,
1686 const char *devname, void *dev_id)
1688 struct irqaction *action;
1689 struct irq_desc *desc;
1692 if (irq == IRQ_NOTCONNECTED)
1696 * Sanity-check: shared interrupts must pass in a real dev-ID,
1697 * otherwise we'll have trouble later trying to figure out
1698 * which interrupt is which (messes up the interrupt freeing
1701 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1702 * it cannot be set along with IRQF_NO_SUSPEND.
1704 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1705 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1706 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1709 desc = irq_to_desc(irq);
1713 if (!irq_settings_can_request(desc) ||
1714 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1720 handler = irq_default_primary_handler;
1723 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1727 action->handler = handler;
1728 action->thread_fn = thread_fn;
1729 action->flags = irqflags;
1730 action->name = devname;
1731 action->dev_id = dev_id;
1733 retval = irq_chip_pm_get(&desc->irq_data);
1739 retval = __setup_irq(irq, desc, action);
1742 irq_chip_pm_put(&desc->irq_data);
1743 kfree(action->secondary);
1747 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1748 if (!retval && (irqflags & IRQF_SHARED)) {
1750 * It's a shared IRQ -- the driver ought to be prepared for it
1751 * to happen immediately, so let's make sure....
1752 * We disable the irq to make sure that a 'real' IRQ doesn't
1753 * run in parallel with our fake.
1755 unsigned long flags;
1758 local_irq_save(flags);
1760 handler(irq, dev_id);
1762 local_irq_restore(flags);
1768 EXPORT_SYMBOL(request_threaded_irq);
1771 * request_any_context_irq - allocate an interrupt line
1772 * @irq: Interrupt line to allocate
1773 * @handler: Function to be called when the IRQ occurs.
1774 * Threaded handler for threaded interrupts.
1775 * @flags: Interrupt type flags
1776 * @name: An ascii name for the claiming device
1777 * @dev_id: A cookie passed back to the handler function
1779 * This call allocates interrupt resources and enables the
1780 * interrupt line and IRQ handling. It selects either a
1781 * hardirq or threaded handling method depending on the
1784 * On failure, it returns a negative value. On success,
1785 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1787 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1788 unsigned long flags, const char *name, void *dev_id)
1790 struct irq_desc *desc;
1793 if (irq == IRQ_NOTCONNECTED)
1796 desc = irq_to_desc(irq);
1800 if (irq_settings_is_nested_thread(desc)) {
1801 ret = request_threaded_irq(irq, NULL, handler,
1802 flags, name, dev_id);
1803 return !ret ? IRQC_IS_NESTED : ret;
1806 ret = request_irq(irq, handler, flags, name, dev_id);
1807 return !ret ? IRQC_IS_HARDIRQ : ret;
1809 EXPORT_SYMBOL_GPL(request_any_context_irq);
1811 void enable_percpu_irq(unsigned int irq, unsigned int type)
1813 unsigned int cpu = smp_processor_id();
1814 unsigned long flags;
1815 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1821 * If the trigger type is not specified by the caller, then
1822 * use the default for this interrupt.
1824 type &= IRQ_TYPE_SENSE_MASK;
1825 if (type == IRQ_TYPE_NONE)
1826 type = irqd_get_trigger_type(&desc->irq_data);
1828 if (type != IRQ_TYPE_NONE) {
1831 ret = __irq_set_trigger(desc, type);
1834 WARN(1, "failed to set type for IRQ%d\n", irq);
1839 irq_percpu_enable(desc, cpu);
1841 irq_put_desc_unlock(desc, flags);
1843 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1846 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1847 * @irq: Linux irq number to check for
1849 * Must be called from a non migratable context. Returns the enable
1850 * state of a per cpu interrupt on the current cpu.
1852 bool irq_percpu_is_enabled(unsigned int irq)
1854 unsigned int cpu = smp_processor_id();
1855 struct irq_desc *desc;
1856 unsigned long flags;
1859 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1863 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1864 irq_put_desc_unlock(desc, flags);
1868 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1870 void disable_percpu_irq(unsigned int irq)
1872 unsigned int cpu = smp_processor_id();
1873 unsigned long flags;
1874 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1879 irq_percpu_disable(desc, cpu);
1880 irq_put_desc_unlock(desc, flags);
1882 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1885 * Internal function to unregister a percpu irqaction.
1887 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1889 struct irq_desc *desc = irq_to_desc(irq);
1890 struct irqaction *action;
1891 unsigned long flags;
1893 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1898 raw_spin_lock_irqsave(&desc->lock, flags);
1900 action = desc->action;
1901 if (!action || action->percpu_dev_id != dev_id) {
1902 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1906 if (!cpumask_empty(desc->percpu_enabled)) {
1907 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1908 irq, cpumask_first(desc->percpu_enabled));
1912 /* Found it - now remove it from the list of entries: */
1913 desc->action = NULL;
1915 raw_spin_unlock_irqrestore(&desc->lock, flags);
1917 unregister_handler_proc(irq, action);
1919 irq_chip_pm_put(&desc->irq_data);
1920 module_put(desc->owner);
1924 raw_spin_unlock_irqrestore(&desc->lock, flags);
1929 * remove_percpu_irq - free a per-cpu interrupt
1930 * @irq: Interrupt line to free
1931 * @act: irqaction for the interrupt
1933 * Used to remove interrupts statically setup by the early boot process.
1935 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1937 struct irq_desc *desc = irq_to_desc(irq);
1939 if (desc && irq_settings_is_per_cpu_devid(desc))
1940 __free_percpu_irq(irq, act->percpu_dev_id);
1944 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1945 * @irq: Interrupt line to free
1946 * @dev_id: Device identity to free
1948 * Remove a percpu interrupt handler. The handler is removed, but
1949 * the interrupt line is not disabled. This must be done on each
1950 * CPU before calling this function. The function does not return
1951 * until any executing interrupts for this IRQ have completed.
1953 * This function must not be called from interrupt context.
1955 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1957 struct irq_desc *desc = irq_to_desc(irq);
1959 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1962 chip_bus_lock(desc);
1963 kfree(__free_percpu_irq(irq, dev_id));
1964 chip_bus_sync_unlock(desc);
1966 EXPORT_SYMBOL_GPL(free_percpu_irq);
1969 * setup_percpu_irq - setup a per-cpu interrupt
1970 * @irq: Interrupt line to setup
1971 * @act: irqaction for the interrupt
1973 * Used to statically setup per-cpu interrupts in the early boot process.
1975 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1977 struct irq_desc *desc = irq_to_desc(irq);
1980 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1983 retval = irq_chip_pm_get(&desc->irq_data);
1987 retval = __setup_irq(irq, desc, act);
1990 irq_chip_pm_put(&desc->irq_data);
1996 * __request_percpu_irq - allocate a percpu interrupt line
1997 * @irq: Interrupt line to allocate
1998 * @handler: Function to be called when the IRQ occurs.
1999 * @flags: Interrupt type flags (IRQF_TIMER only)
2000 * @devname: An ascii name for the claiming device
2001 * @dev_id: A percpu cookie passed back to the handler function
2003 * This call allocates interrupt resources and enables the
2004 * interrupt on the local CPU. If the interrupt is supposed to be
2005 * enabled on other CPUs, it has to be done on each CPU using
2006 * enable_percpu_irq().
2008 * Dev_id must be globally unique. It is a per-cpu variable, and
2009 * the handler gets called with the interrupted CPU's instance of
2012 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2013 unsigned long flags, const char *devname,
2014 void __percpu *dev_id)
2016 struct irqaction *action;
2017 struct irq_desc *desc;
2023 desc = irq_to_desc(irq);
2024 if (!desc || !irq_settings_can_request(desc) ||
2025 !irq_settings_is_per_cpu_devid(desc))
2028 if (flags && flags != IRQF_TIMER)
2031 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2035 action->handler = handler;
2036 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2037 action->name = devname;
2038 action->percpu_dev_id = dev_id;
2040 retval = irq_chip_pm_get(&desc->irq_data);
2046 retval = __setup_irq(irq, desc, action);
2049 irq_chip_pm_put(&desc->irq_data);
2055 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2058 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2059 * @irq: Interrupt line that is forwarded to a VM
2060 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2061 * @state: a pointer to a boolean where the state is to be storeed
2063 * This call snapshots the internal irqchip state of an
2064 * interrupt, returning into @state the bit corresponding to
2067 * This function should be called with preemption disabled if the
2068 * interrupt controller has per-cpu registers.
2070 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2073 struct irq_desc *desc;
2074 struct irq_data *data;
2075 struct irq_chip *chip;
2076 unsigned long flags;
2079 desc = irq_get_desc_buslock(irq, &flags, 0);
2083 data = irq_desc_get_irq_data(desc);
2086 chip = irq_data_get_irq_chip(data);
2087 if (chip->irq_get_irqchip_state)
2089 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2090 data = data->parent_data;
2097 err = chip->irq_get_irqchip_state(data, which, state);
2099 irq_put_desc_busunlock(desc, flags);
2102 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2105 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2106 * @irq: Interrupt line that is forwarded to a VM
2107 * @which: State to be restored (one of IRQCHIP_STATE_*)
2108 * @val: Value corresponding to @which
2110 * This call sets the internal irqchip state of an interrupt,
2111 * depending on the value of @which.
2113 * This function should be called with preemption disabled if the
2114 * interrupt controller has per-cpu registers.
2116 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2119 struct irq_desc *desc;
2120 struct irq_data *data;
2121 struct irq_chip *chip;
2122 unsigned long flags;
2125 desc = irq_get_desc_buslock(irq, &flags, 0);
2129 data = irq_desc_get_irq_data(desc);
2132 chip = irq_data_get_irq_chip(data);
2133 if (chip->irq_set_irqchip_state)
2135 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2136 data = data->parent_data;
2143 err = chip->irq_set_irqchip_state(data, which, val);
2145 irq_put_desc_busunlock(desc, flags);
2148 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);