2 * linux/kernel/irq/manage.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
7 * This file contains driver APIs to the irq subsystem.
10 #define pr_fmt(fmt) "genirq: " fmt
12 #include <linux/irq.h>
13 #include <linux/kthread.h>
14 #include <linux/module.h>
15 #include <linux/random.h>
16 #include <linux/interrupt.h>
17 #include <linux/slab.h>
18 #include <linux/sched.h>
19 #include <linux/sched/rt.h>
20 #include <linux/task_work.h>
22 #include "internals.h"
24 #ifdef CONFIG_IRQ_FORCED_THREADING
25 __read_mostly bool force_irqthreads;
27 static int __init setup_forced_irqthreads(char *arg)
29 force_irqthreads = true;
32 early_param("threadirqs", setup_forced_irqthreads);
35 static void __synchronize_hardirq(struct irq_desc *desc)
43 * Wait until we're out of the critical section. This might
44 * give the wrong answer due to the lack of memory barriers.
46 while (irqd_irq_inprogress(&desc->irq_data))
49 /* Ok, that indicated we're done: double-check carefully. */
50 raw_spin_lock_irqsave(&desc->lock, flags);
51 inprogress = irqd_irq_inprogress(&desc->irq_data);
52 raw_spin_unlock_irqrestore(&desc->lock, flags);
54 /* Oops, that failed? */
59 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
60 * @irq: interrupt number to wait for
62 * This function waits for any pending hard IRQ handlers for this
63 * interrupt to complete before returning. If you use this
64 * function while holding a resource the IRQ handler may need you
65 * will deadlock. It does not take associated threaded handlers
68 * Do not use this for shutdown scenarios where you must be sure
69 * that all parts (hardirq and threaded handler) have completed.
71 * Returns: false if a threaded handler is active.
73 * This function may be called - with care - from IRQ context.
75 bool synchronize_hardirq(unsigned int irq)
77 struct irq_desc *desc = irq_to_desc(irq);
80 __synchronize_hardirq(desc);
81 return !atomic_read(&desc->threads_active);
86 EXPORT_SYMBOL(synchronize_hardirq);
89 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
90 * @irq: interrupt number to wait for
92 * This function waits for any pending IRQ handlers for this interrupt
93 * to complete before returning. If you use this function while
94 * holding a resource the IRQ handler may need you will deadlock.
96 * This function may be called - with care - from IRQ context.
98 void synchronize_irq(unsigned int irq)
100 struct irq_desc *desc = irq_to_desc(irq);
103 __synchronize_hardirq(desc);
105 * We made sure that no hardirq handler is
106 * running. Now verify that no threaded handlers are
109 wait_event(desc->wait_for_threads,
110 !atomic_read(&desc->threads_active));
113 EXPORT_SYMBOL(synchronize_irq);
116 cpumask_var_t irq_default_affinity;
118 static int __irq_can_set_affinity(struct irq_desc *desc)
120 if (!desc || !irqd_can_balance(&desc->irq_data) ||
121 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
127 * irq_can_set_affinity - Check if the affinity of a given irq can be set
128 * @irq: Interrupt to check
131 int irq_can_set_affinity(unsigned int irq)
133 return __irq_can_set_affinity(irq_to_desc(irq));
137 * irq_set_thread_affinity - Notify irq threads to adjust affinity
138 * @desc: irq descriptor which has affitnity changed
140 * We just set IRQTF_AFFINITY and delegate the affinity setting
141 * to the interrupt thread itself. We can not call
142 * set_cpus_allowed_ptr() here as we hold desc->lock and this
143 * code can be called from hard interrupt context.
145 void irq_set_thread_affinity(struct irq_desc *desc)
147 struct irqaction *action = desc->action;
151 set_bit(IRQTF_AFFINITY, &action->thread_flags);
152 action = action->next;
156 #ifdef CONFIG_GENERIC_PENDING_IRQ
157 static inline bool irq_can_move_pcntxt(struct irq_data *data)
159 return irqd_can_move_in_process_context(data);
161 static inline bool irq_move_pending(struct irq_data *data)
163 return irqd_is_setaffinity_pending(data);
166 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
168 cpumask_copy(desc->pending_mask, mask);
171 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
173 cpumask_copy(mask, desc->pending_mask);
176 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
177 static inline bool irq_move_pending(struct irq_data *data) { return false; }
179 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
181 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
184 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
187 struct irq_desc *desc = irq_data_to_desc(data);
188 struct irq_chip *chip = irq_data_get_irq_chip(data);
191 ret = chip->irq_set_affinity(data, mask, force);
193 case IRQ_SET_MASK_OK:
194 case IRQ_SET_MASK_OK_DONE:
195 cpumask_copy(desc->irq_common_data.affinity, mask);
196 case IRQ_SET_MASK_OK_NOCOPY:
197 irq_set_thread_affinity(desc);
204 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
207 struct irq_chip *chip = irq_data_get_irq_chip(data);
208 struct irq_desc *desc = irq_data_to_desc(data);
211 if (!chip || !chip->irq_set_affinity)
214 if (irq_can_move_pcntxt(data)) {
215 ret = irq_do_set_affinity(data, mask, force);
217 irqd_set_move_pending(data);
218 irq_copy_pending(desc, mask);
221 if (desc->affinity_notify) {
222 kref_get(&desc->affinity_notify->kref);
223 if (!schedule_work(&desc->affinity_notify->work)) {
224 /* Work was already scheduled, drop our extra ref */
225 kref_put(&desc->affinity_notify->kref,
226 desc->affinity_notify->release);
229 irqd_set(data, IRQD_AFFINITY_SET);
234 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
236 struct irq_desc *desc = irq_to_desc(irq);
243 raw_spin_lock_irqsave(&desc->lock, flags);
244 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
245 raw_spin_unlock_irqrestore(&desc->lock, flags);
249 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
252 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
256 desc->affinity_hint = m;
257 irq_put_desc_unlock(desc, flags);
258 /* set the initial affinity to prevent every interrupt being on CPU0 */
260 __irq_set_affinity(irq, m, false);
263 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
265 static void irq_affinity_notify(struct work_struct *work)
267 struct irq_affinity_notify *notify =
268 container_of(work, struct irq_affinity_notify, work);
269 struct irq_desc *desc = irq_to_desc(notify->irq);
270 cpumask_var_t cpumask;
273 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
276 raw_spin_lock_irqsave(&desc->lock, flags);
277 if (irq_move_pending(&desc->irq_data))
278 irq_get_pending(cpumask, desc);
280 cpumask_copy(cpumask, desc->irq_common_data.affinity);
281 raw_spin_unlock_irqrestore(&desc->lock, flags);
283 notify->notify(notify, cpumask);
285 free_cpumask_var(cpumask);
287 kref_put(¬ify->kref, notify->release);
291 * irq_set_affinity_notifier - control notification of IRQ affinity changes
292 * @irq: Interrupt for which to enable/disable notification
293 * @notify: Context for notification, or %NULL to disable
294 * notification. Function pointers must be initialised;
295 * the other fields will be initialised by this function.
297 * Must be called in process context. Notification may only be enabled
298 * after the IRQ is allocated and must be disabled before the IRQ is
299 * freed using free_irq().
302 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
304 struct irq_desc *desc = irq_to_desc(irq);
305 struct irq_affinity_notify *old_notify;
308 /* The release function is promised process context */
314 /* Complete initialisation of *notify */
317 kref_init(¬ify->kref);
318 INIT_WORK(¬ify->work, irq_affinity_notify);
321 raw_spin_lock_irqsave(&desc->lock, flags);
322 old_notify = desc->affinity_notify;
323 desc->affinity_notify = notify;
324 raw_spin_unlock_irqrestore(&desc->lock, flags);
327 if (cancel_work_sync(&old_notify->work)) {
328 /* Pending work had a ref, put that one too */
329 kref_put(&old_notify->kref, old_notify->release);
331 kref_put(&old_notify->kref, old_notify->release);
336 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
338 #ifndef CONFIG_AUTO_IRQ_AFFINITY
340 * Generic version of the affinity autoselector.
342 static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
344 struct cpumask *set = irq_default_affinity;
345 int node = irq_desc_get_node(desc);
347 /* Excludes PER_CPU and NO_BALANCE interrupts */
348 if (!__irq_can_set_affinity(desc))
352 * Preserve an userspace affinity setup, but make sure that
353 * one of the targets is online.
355 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
356 if (cpumask_intersects(desc->irq_common_data.affinity,
358 set = desc->irq_common_data.affinity;
360 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
363 cpumask_and(mask, cpu_online_mask, set);
364 if (node != NUMA_NO_NODE) {
365 const struct cpumask *nodemask = cpumask_of_node(node);
367 /* make sure at least one of the cpus in nodemask is online */
368 if (cpumask_intersects(mask, nodemask))
369 cpumask_and(mask, mask, nodemask);
371 irq_do_set_affinity(&desc->irq_data, mask, false);
375 /* Wrapper for ALPHA specific affinity selector magic */
376 static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
378 return irq_select_affinity(irq_desc_get_irq(d));
383 * Called when affinity is set via /proc/irq
385 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
387 struct irq_desc *desc = irq_to_desc(irq);
391 raw_spin_lock_irqsave(&desc->lock, flags);
392 ret = setup_affinity(desc, mask);
393 raw_spin_unlock_irqrestore(&desc->lock, flags);
399 setup_affinity(struct irq_desc *desc, struct cpumask *mask)
406 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
407 * @irq: interrupt number to set affinity
408 * @vcpu_info: vCPU specific data
410 * This function uses the vCPU specific data to set the vCPU
411 * affinity for an irq. The vCPU specific data is passed from
412 * outside, such as KVM. One example code path is as below:
413 * KVM -> IOMMU -> irq_set_vcpu_affinity().
415 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
418 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
419 struct irq_data *data;
420 struct irq_chip *chip;
426 data = irq_desc_get_irq_data(desc);
427 chip = irq_data_get_irq_chip(data);
428 if (chip && chip->irq_set_vcpu_affinity)
429 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
430 irq_put_desc_unlock(desc, flags);
434 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
436 void __disable_irq(struct irq_desc *desc)
442 static int __disable_irq_nosync(unsigned int irq)
445 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
450 irq_put_desc_busunlock(desc, flags);
455 * disable_irq_nosync - disable an irq without waiting
456 * @irq: Interrupt to disable
458 * Disable the selected interrupt line. Disables and Enables are
460 * Unlike disable_irq(), this function does not ensure existing
461 * instances of the IRQ handler have completed before returning.
463 * This function may be called from IRQ context.
465 void disable_irq_nosync(unsigned int irq)
467 __disable_irq_nosync(irq);
469 EXPORT_SYMBOL(disable_irq_nosync);
472 * disable_irq - disable an irq and wait for completion
473 * @irq: Interrupt to disable
475 * Disable the selected interrupt line. Enables and Disables are
477 * This function waits for any pending IRQ handlers for this interrupt
478 * to complete before returning. If you use this function while
479 * holding a resource the IRQ handler may need you will deadlock.
481 * This function may be called - with care - from IRQ context.
483 void disable_irq(unsigned int irq)
485 if (!__disable_irq_nosync(irq))
486 synchronize_irq(irq);
488 EXPORT_SYMBOL(disable_irq);
491 * disable_hardirq - disables an irq and waits for hardirq completion
492 * @irq: Interrupt to disable
494 * Disable the selected interrupt line. Enables and Disables are
496 * This function waits for any pending hard IRQ handlers for this
497 * interrupt to complete before returning. If you use this function while
498 * holding a resource the hard IRQ handler may need you will deadlock.
500 * When used to optimistically disable an interrupt from atomic context
501 * the return value must be checked.
503 * Returns: false if a threaded handler is active.
505 * This function may be called - with care - from IRQ context.
507 bool disable_hardirq(unsigned int irq)
509 if (!__disable_irq_nosync(irq))
510 return synchronize_hardirq(irq);
514 EXPORT_SYMBOL_GPL(disable_hardirq);
516 void __enable_irq(struct irq_desc *desc)
518 switch (desc->depth) {
521 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
522 irq_desc_get_irq(desc));
525 if (desc->istate & IRQS_SUSPENDED)
527 /* Prevent probing on this irq: */
528 irq_settings_set_noprobe(desc);
530 check_irq_resend(desc);
539 * enable_irq - enable handling of an irq
540 * @irq: Interrupt to enable
542 * Undoes the effect of one call to disable_irq(). If this
543 * matches the last disable, processing of interrupts on this
544 * IRQ line is re-enabled.
546 * This function may be called from IRQ context only when
547 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
549 void enable_irq(unsigned int irq)
552 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
556 if (WARN(!desc->irq_data.chip,
557 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
562 irq_put_desc_busunlock(desc, flags);
564 EXPORT_SYMBOL(enable_irq);
566 static int set_irq_wake_real(unsigned int irq, unsigned int on)
568 struct irq_desc *desc = irq_to_desc(irq);
571 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
574 if (desc->irq_data.chip->irq_set_wake)
575 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
581 * irq_set_irq_wake - control irq power management wakeup
582 * @irq: interrupt to control
583 * @on: enable/disable power management wakeup
585 * Enable/disable power management wakeup mode, which is
586 * disabled by default. Enables and disables must match,
587 * just as they match for non-wakeup mode support.
589 * Wakeup mode lets this IRQ wake the system from sleep
590 * states like "suspend to RAM".
592 int irq_set_irq_wake(unsigned int irq, unsigned int on)
595 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
601 /* wakeup-capable irqs can be shared between drivers that
602 * don't need to have the same sleep mode behaviors.
605 if (desc->wake_depth++ == 0) {
606 ret = set_irq_wake_real(irq, on);
608 desc->wake_depth = 0;
610 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
613 if (desc->wake_depth == 0) {
614 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
615 } else if (--desc->wake_depth == 0) {
616 ret = set_irq_wake_real(irq, on);
618 desc->wake_depth = 1;
620 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
623 irq_put_desc_busunlock(desc, flags);
626 EXPORT_SYMBOL(irq_set_irq_wake);
629 * Internal function that tells the architecture code whether a
630 * particular irq has been exclusively allocated or is available
633 int can_request_irq(unsigned int irq, unsigned long irqflags)
636 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
642 if (irq_settings_can_request(desc)) {
644 irqflags & desc->action->flags & IRQF_SHARED)
647 irq_put_desc_unlock(desc, flags);
651 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
653 struct irq_chip *chip = desc->irq_data.chip;
656 if (!chip || !chip->irq_set_type) {
658 * IRQF_TRIGGER_* but the PIC does not support multiple
661 pr_debug("No set_type function for IRQ %d (%s)\n",
662 irq_desc_get_irq(desc),
663 chip ? (chip->name ? : "unknown") : "unknown");
667 flags &= IRQ_TYPE_SENSE_MASK;
669 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
670 if (!irqd_irq_masked(&desc->irq_data))
672 if (!irqd_irq_disabled(&desc->irq_data))
676 /* caller masked out all except trigger mode flags */
677 ret = chip->irq_set_type(&desc->irq_data, flags);
680 case IRQ_SET_MASK_OK:
681 case IRQ_SET_MASK_OK_DONE:
682 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
683 irqd_set(&desc->irq_data, flags);
685 case IRQ_SET_MASK_OK_NOCOPY:
686 flags = irqd_get_trigger_type(&desc->irq_data);
687 irq_settings_set_trigger_mask(desc, flags);
688 irqd_clear(&desc->irq_data, IRQD_LEVEL);
689 irq_settings_clr_level(desc);
690 if (flags & IRQ_TYPE_LEVEL_MASK) {
691 irq_settings_set_level(desc);
692 irqd_set(&desc->irq_data, IRQD_LEVEL);
698 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
699 flags, irq_desc_get_irq(desc), chip->irq_set_type);
706 #ifdef CONFIG_HARDIRQS_SW_RESEND
707 int irq_set_parent(int irq, int parent_irq)
710 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
715 desc->parent_irq = parent_irq;
717 irq_put_desc_unlock(desc, flags);
723 * Default primary interrupt handler for threaded interrupts. Is
724 * assigned as primary handler when request_threaded_irq is called
725 * with handler == NULL. Useful for oneshot interrupts.
727 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
729 return IRQ_WAKE_THREAD;
733 * Primary handler for nested threaded interrupts. Should never be
736 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
738 WARN(1, "Primary handler called for nested irq %d\n", irq);
742 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
744 WARN(1, "Secondary action handler called for irq %d\n", irq);
748 static int irq_wait_for_interrupt(struct irqaction *action)
750 set_current_state(TASK_INTERRUPTIBLE);
752 while (!kthread_should_stop()) {
754 if (test_and_clear_bit(IRQTF_RUNTHREAD,
755 &action->thread_flags)) {
756 __set_current_state(TASK_RUNNING);
760 set_current_state(TASK_INTERRUPTIBLE);
762 __set_current_state(TASK_RUNNING);
767 * Oneshot interrupts keep the irq line masked until the threaded
768 * handler finished. unmask if the interrupt has not been disabled and
771 static void irq_finalize_oneshot(struct irq_desc *desc,
772 struct irqaction *action)
774 if (!(desc->istate & IRQS_ONESHOT) ||
775 action->handler == irq_forced_secondary_handler)
779 raw_spin_lock_irq(&desc->lock);
782 * Implausible though it may be we need to protect us against
783 * the following scenario:
785 * The thread is faster done than the hard interrupt handler
786 * on the other CPU. If we unmask the irq line then the
787 * interrupt can come in again and masks the line, leaves due
788 * to IRQS_INPROGRESS and the irq line is masked forever.
790 * This also serializes the state of shared oneshot handlers
791 * versus "desc->threads_onehsot |= action->thread_mask;" in
792 * irq_wake_thread(). See the comment there which explains the
795 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
796 raw_spin_unlock_irq(&desc->lock);
797 chip_bus_sync_unlock(desc);
803 * Now check again, whether the thread should run. Otherwise
804 * we would clear the threads_oneshot bit of this thread which
807 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
810 desc->threads_oneshot &= ~action->thread_mask;
812 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
813 irqd_irq_masked(&desc->irq_data))
814 unmask_threaded_irq(desc);
817 raw_spin_unlock_irq(&desc->lock);
818 chip_bus_sync_unlock(desc);
823 * Check whether we need to change the affinity of the interrupt thread.
826 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
831 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
835 * In case we are out of memory we set IRQTF_AFFINITY again and
836 * try again next time
838 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
839 set_bit(IRQTF_AFFINITY, &action->thread_flags);
843 raw_spin_lock_irq(&desc->lock);
845 * This code is triggered unconditionally. Check the affinity
846 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
848 if (cpumask_available(desc->irq_common_data.affinity))
849 cpumask_copy(mask, desc->irq_common_data.affinity);
852 raw_spin_unlock_irq(&desc->lock);
855 set_cpus_allowed_ptr(current, mask);
856 free_cpumask_var(mask);
860 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
864 * Interrupts which are not explicitely requested as threaded
865 * interrupts rely on the implicit bh/preempt disable of the hard irq
866 * context. So we need to disable bh here to avoid deadlocks and other
870 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
875 if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE))
877 ret = action->thread_fn(action->irq, action->dev_id);
878 if (ret == IRQ_HANDLED)
879 atomic_inc(&desc->threads_handled);
881 irq_finalize_oneshot(desc, action);
882 if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE))
889 * Interrupts explicitly requested as threaded interrupts want to be
890 * preemtible - many of them need to sleep and wait for slow busses to
893 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
894 struct irqaction *action)
898 ret = action->thread_fn(action->irq, action->dev_id);
899 if (ret == IRQ_HANDLED)
900 atomic_inc(&desc->threads_handled);
902 irq_finalize_oneshot(desc, action);
906 static void wake_threads_waitq(struct irq_desc *desc)
908 if (atomic_dec_and_test(&desc->threads_active))
909 wake_up(&desc->wait_for_threads);
912 static void irq_thread_dtor(struct callback_head *unused)
914 struct task_struct *tsk = current;
915 struct irq_desc *desc;
916 struct irqaction *action;
918 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
921 action = kthread_data(tsk);
923 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
924 tsk->comm, tsk->pid, action->irq);
927 desc = irq_to_desc(action->irq);
929 * If IRQTF_RUNTHREAD is set, we need to decrement
930 * desc->threads_active and wake possible waiters.
932 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
933 wake_threads_waitq(desc);
935 /* Prevent a stale desc->threads_oneshot */
936 irq_finalize_oneshot(desc, action);
939 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
941 struct irqaction *secondary = action->secondary;
943 if (WARN_ON_ONCE(!secondary))
946 raw_spin_lock_irq(&desc->lock);
947 __irq_wake_thread(desc, secondary);
948 raw_spin_unlock_irq(&desc->lock);
952 * Interrupt handler thread
954 static int irq_thread(void *data)
956 struct callback_head on_exit_work;
957 struct irqaction *action = data;
958 struct irq_desc *desc = irq_to_desc(action->irq);
959 irqreturn_t (*handler_fn)(struct irq_desc *desc,
960 struct irqaction *action);
962 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
963 &action->thread_flags))
964 handler_fn = irq_forced_thread_fn;
966 handler_fn = irq_thread_fn;
968 init_task_work(&on_exit_work, irq_thread_dtor);
969 task_work_add(current, &on_exit_work, false);
971 irq_thread_check_affinity(desc, action);
973 while (!irq_wait_for_interrupt(action)) {
974 irqreturn_t action_ret;
976 irq_thread_check_affinity(desc, action);
978 action_ret = handler_fn(desc, action);
979 if (action_ret == IRQ_WAKE_THREAD)
980 irq_wake_secondary(desc, action);
982 wake_threads_waitq(desc);
986 * This is the regular exit path. __free_irq() is stopping the
987 * thread via kthread_stop() after calling
988 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
989 * oneshot mask bit can be set. We cannot verify that as we
990 * cannot touch the oneshot mask at this point anymore as
991 * __setup_irq() might have given out currents thread_mask
994 task_work_cancel(current, irq_thread_dtor);
999 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1000 * @irq: Interrupt line
1001 * @dev_id: Device identity for which the thread should be woken
1004 void irq_wake_thread(unsigned int irq, void *dev_id)
1006 struct irq_desc *desc = irq_to_desc(irq);
1007 struct irqaction *action;
1008 unsigned long flags;
1010 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1013 raw_spin_lock_irqsave(&desc->lock, flags);
1014 for (action = desc->action; action; action = action->next) {
1015 if (action->dev_id == dev_id) {
1017 __irq_wake_thread(desc, action);
1021 raw_spin_unlock_irqrestore(&desc->lock, flags);
1023 EXPORT_SYMBOL_GPL(irq_wake_thread);
1025 static int irq_setup_forced_threading(struct irqaction *new)
1027 if (!force_irqthreads)
1029 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1033 * No further action required for interrupts which are requested as
1034 * threaded interrupts already
1036 if (new->handler == irq_default_primary_handler)
1039 new->flags |= IRQF_ONESHOT;
1042 * Handle the case where we have a real primary handler and a
1043 * thread handler. We force thread them as well by creating a
1046 if (new->handler && new->thread_fn) {
1047 /* Allocate the secondary action */
1048 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1049 if (!new->secondary)
1051 new->secondary->handler = irq_forced_secondary_handler;
1052 new->secondary->thread_fn = new->thread_fn;
1053 new->secondary->dev_id = new->dev_id;
1054 new->secondary->irq = new->irq;
1055 new->secondary->name = new->name;
1057 /* Deal with the primary handler */
1058 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1059 new->thread_fn = new->handler;
1060 new->handler = irq_default_primary_handler;
1064 static int irq_request_resources(struct irq_desc *desc)
1066 struct irq_data *d = &desc->irq_data;
1067 struct irq_chip *c = d->chip;
1069 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1072 static void irq_release_resources(struct irq_desc *desc)
1074 struct irq_data *d = &desc->irq_data;
1075 struct irq_chip *c = d->chip;
1077 if (c->irq_release_resources)
1078 c->irq_release_resources(d);
1082 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1084 struct task_struct *t;
1085 struct sched_param param = {
1086 .sched_priority = MAX_USER_RT_PRIO/2,
1090 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1093 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1095 param.sched_priority -= 1;
1101 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1104 * We keep the reference to the task struct even if
1105 * the thread dies to avoid that the interrupt code
1106 * references an already freed task_struct.
1111 * Tell the thread to set its affinity. This is
1112 * important for shared interrupt handlers as we do
1113 * not invoke setup_affinity() for the secondary
1114 * handlers as everything is already set up. Even for
1115 * interrupts marked with IRQF_NO_BALANCE this is
1116 * correct as we want the thread to move to the cpu(s)
1117 * on which the requesting code placed the interrupt.
1119 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1124 * Internal function to register an irqaction - typically used to
1125 * allocate special interrupts that are part of the architecture.
1128 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1130 struct irqaction *old, **old_ptr;
1131 unsigned long flags, thread_mask = 0;
1132 int ret, nested, shared = 0;
1138 if (desc->irq_data.chip == &no_irq_chip)
1140 if (!try_module_get(desc->owner))
1146 * Check whether the interrupt nests into another interrupt
1149 nested = irq_settings_is_nested_thread(desc);
1151 if (!new->thread_fn) {
1156 * Replace the primary handler which was provided from
1157 * the driver for non nested interrupt handling by the
1158 * dummy function which warns when called.
1160 new->handler = irq_nested_primary_handler;
1162 if (irq_settings_can_thread(desc)) {
1163 ret = irq_setup_forced_threading(new);
1170 * Create a handler thread when a thread function is supplied
1171 * and the interrupt does not nest into another interrupt
1174 if (new->thread_fn && !nested) {
1175 ret = setup_irq_thread(new, irq, false);
1178 if (new->secondary) {
1179 ret = setup_irq_thread(new->secondary, irq, true);
1185 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1191 * Drivers are often written to work w/o knowledge about the
1192 * underlying irq chip implementation, so a request for a
1193 * threaded irq without a primary hard irq context handler
1194 * requires the ONESHOT flag to be set. Some irq chips like
1195 * MSI based interrupts are per se one shot safe. Check the
1196 * chip flags, so we can avoid the unmask dance at the end of
1197 * the threaded handler for those.
1199 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1200 new->flags &= ~IRQF_ONESHOT;
1203 * The following block of code has to be executed atomically
1205 raw_spin_lock_irqsave(&desc->lock, flags);
1206 old_ptr = &desc->action;
1210 * Can't share interrupts unless both agree to and are
1211 * the same type (level, edge, polarity). So both flag
1212 * fields must have IRQF_SHARED set and the bits which
1213 * set the trigger type must match. Also all must
1216 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1217 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1218 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1221 /* All handlers must agree on per-cpuness */
1222 if ((old->flags & IRQF_PERCPU) !=
1223 (new->flags & IRQF_PERCPU))
1226 /* add new interrupt at end of irq queue */
1229 * Or all existing action->thread_mask bits,
1230 * so we can find the next zero bit for this
1233 thread_mask |= old->thread_mask;
1234 old_ptr = &old->next;
1241 * Setup the thread mask for this irqaction for ONESHOT. For
1242 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1243 * conditional in irq_wake_thread().
1245 if (new->flags & IRQF_ONESHOT) {
1247 * Unlikely to have 32 resp 64 irqs sharing one line,
1250 if (thread_mask == ~0UL) {
1255 * The thread_mask for the action is or'ed to
1256 * desc->thread_active to indicate that the
1257 * IRQF_ONESHOT thread handler has been woken, but not
1258 * yet finished. The bit is cleared when a thread
1259 * completes. When all threads of a shared interrupt
1260 * line have completed desc->threads_active becomes
1261 * zero and the interrupt line is unmasked. See
1262 * handle.c:irq_wake_thread() for further information.
1264 * If no thread is woken by primary (hard irq context)
1265 * interrupt handlers, then desc->threads_active is
1266 * also checked for zero to unmask the irq line in the
1267 * affected hard irq flow handlers
1268 * (handle_[fasteoi|level]_irq).
1270 * The new action gets the first zero bit of
1271 * thread_mask assigned. See the loop above which or's
1272 * all existing action->thread_mask bits.
1274 new->thread_mask = 1 << ffz(thread_mask);
1276 } else if (new->handler == irq_default_primary_handler &&
1277 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1279 * The interrupt was requested with handler = NULL, so
1280 * we use the default primary handler for it. But it
1281 * does not have the oneshot flag set. In combination
1282 * with level interrupts this is deadly, because the
1283 * default primary handler just wakes the thread, then
1284 * the irq lines is reenabled, but the device still
1285 * has the level irq asserted. Rinse and repeat....
1287 * While this works for edge type interrupts, we play
1288 * it safe and reject unconditionally because we can't
1289 * say for sure which type this interrupt really
1290 * has. The type flags are unreliable as the
1291 * underlying chip implementation can override them.
1293 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1300 ret = irq_request_resources(desc);
1302 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1303 new->name, irq, desc->irq_data.chip->name);
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);
1315 irq_release_resources(desc);
1320 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1321 IRQS_ONESHOT | IRQS_WAITING);
1322 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1324 if (new->flags & IRQF_PERCPU) {
1325 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1326 irq_settings_set_per_cpu(desc);
1329 if (new->flags & IRQF_ONESHOT)
1330 desc->istate |= IRQS_ONESHOT;
1332 if (irq_settings_can_autoenable(desc))
1333 irq_startup(desc, true);
1335 /* Undo nested disables: */
1338 /* Exclude IRQ from balancing if requested */
1339 if (new->flags & IRQF_NOBALANCING) {
1340 irq_settings_set_no_balancing(desc);
1341 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1344 /* Set default affinity mask once everything is setup */
1345 setup_affinity(desc, mask);
1347 } else if (new->flags & IRQF_TRIGGER_MASK) {
1348 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1349 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1352 /* hope the handler works with current trigger mode */
1353 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1359 irq_pm_install_action(desc, new);
1361 /* Reset broken irq detection when installing new handler */
1362 desc->irq_count = 0;
1363 desc->irqs_unhandled = 0;
1366 * Check whether we disabled the irq via the spurious handler
1367 * before. Reenable it and give it another chance.
1369 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1370 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1374 raw_spin_unlock_irqrestore(&desc->lock, flags);
1377 * Strictly no need to wake it up, but hung_task complains
1378 * when no hard interrupt wakes the thread up.
1381 wake_up_process(new->thread);
1383 wake_up_process(new->secondary->thread);
1385 register_irq_proc(irq, desc);
1387 register_handler_proc(irq, new);
1388 free_cpumask_var(mask);
1393 if (!(new->flags & IRQF_PROBE_SHARED)) {
1394 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1395 irq, new->flags, new->name, old->flags, old->name);
1396 #ifdef CONFIG_DEBUG_SHIRQ
1403 raw_spin_unlock_irqrestore(&desc->lock, flags);
1404 free_cpumask_var(mask);
1408 struct task_struct *t = new->thread;
1414 if (new->secondary && new->secondary->thread) {
1415 struct task_struct *t = new->secondary->thread;
1417 new->secondary->thread = NULL;
1422 module_put(desc->owner);
1427 * setup_irq - setup an interrupt
1428 * @irq: Interrupt line to setup
1429 * @act: irqaction for the interrupt
1431 * Used to statically setup interrupts in the early boot process.
1433 int setup_irq(unsigned int irq, struct irqaction *act)
1436 struct irq_desc *desc = irq_to_desc(irq);
1438 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1440 chip_bus_lock(desc);
1441 retval = __setup_irq(irq, desc, act);
1442 chip_bus_sync_unlock(desc);
1446 EXPORT_SYMBOL_GPL(setup_irq);
1449 * Internal function to unregister an irqaction - used to free
1450 * regular and special interrupts that are part of the architecture.
1452 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1454 struct irq_desc *desc = irq_to_desc(irq);
1455 struct irqaction *action, **action_ptr;
1456 unsigned long flags;
1458 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1463 chip_bus_lock(desc);
1464 raw_spin_lock_irqsave(&desc->lock, flags);
1467 * There can be multiple actions per IRQ descriptor, find the right
1468 * one based on the dev_id:
1470 action_ptr = &desc->action;
1472 action = *action_ptr;
1475 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1476 raw_spin_unlock_irqrestore(&desc->lock, flags);
1477 chip_bus_sync_unlock(desc);
1481 if (action->dev_id == dev_id)
1483 action_ptr = &action->next;
1486 /* Found it - now remove it from the list of entries: */
1487 *action_ptr = action->next;
1489 irq_pm_remove_action(desc, action);
1491 /* If this was the last handler, shut down the IRQ line: */
1492 if (!desc->action) {
1493 irq_settings_clr_disable_unlazy(desc);
1495 irq_release_resources(desc);
1499 /* make sure affinity_hint is cleaned up */
1500 if (WARN_ON_ONCE(desc->affinity_hint))
1501 desc->affinity_hint = NULL;
1504 raw_spin_unlock_irqrestore(&desc->lock, flags);
1505 chip_bus_sync_unlock(desc);
1507 unregister_handler_proc(irq, action);
1509 /* Make sure it's not being used on another CPU: */
1510 synchronize_irq(irq);
1512 #ifdef CONFIG_DEBUG_SHIRQ
1514 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1515 * event to happen even now it's being freed, so let's make sure that
1516 * is so by doing an extra call to the handler ....
1518 * ( We do this after actually deregistering it, to make sure that a
1519 * 'real' IRQ doesn't run in * parallel with our fake. )
1521 if (action->flags & IRQF_SHARED) {
1522 local_irq_save(flags);
1523 action->handler(irq, dev_id);
1524 local_irq_restore(flags);
1528 if (action->thread) {
1529 kthread_stop(action->thread);
1530 put_task_struct(action->thread);
1531 if (action->secondary && action->secondary->thread) {
1532 kthread_stop(action->secondary->thread);
1533 put_task_struct(action->secondary->thread);
1537 module_put(desc->owner);
1538 kfree(action->secondary);
1543 * remove_irq - free an interrupt
1544 * @irq: Interrupt line to free
1545 * @act: irqaction for the interrupt
1547 * Used to remove interrupts statically setup by the early boot process.
1549 void remove_irq(unsigned int irq, struct irqaction *act)
1551 struct irq_desc *desc = irq_to_desc(irq);
1553 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1554 __free_irq(irq, act->dev_id);
1556 EXPORT_SYMBOL_GPL(remove_irq);
1559 * free_irq - free an interrupt allocated with request_irq
1560 * @irq: Interrupt line to free
1561 * @dev_id: Device identity to free
1563 * Remove an interrupt handler. The handler is removed and if the
1564 * interrupt line is no longer in use by any driver it is disabled.
1565 * On a shared IRQ the caller must ensure the interrupt is disabled
1566 * on the card it drives before calling this function. The function
1567 * does not return until any executing interrupts for this IRQ
1570 * This function must not be called from interrupt context.
1572 void free_irq(unsigned int irq, void *dev_id)
1574 struct irq_desc *desc = irq_to_desc(irq);
1576 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1580 if (WARN_ON(desc->affinity_notify))
1581 desc->affinity_notify = NULL;
1584 kfree(__free_irq(irq, dev_id));
1586 EXPORT_SYMBOL(free_irq);
1589 * request_threaded_irq - allocate an interrupt line
1590 * @irq: Interrupt line to allocate
1591 * @handler: Function to be called when the IRQ occurs.
1592 * Primary handler for threaded interrupts
1593 * If NULL and thread_fn != NULL the default
1594 * primary handler is installed
1595 * @thread_fn: Function called from the irq handler thread
1596 * If NULL, no irq thread is created
1597 * @irqflags: Interrupt type flags
1598 * @devname: An ascii name for the claiming device
1599 * @dev_id: A cookie passed back to the handler function
1601 * This call allocates interrupt resources and enables the
1602 * interrupt line and IRQ handling. From the point this
1603 * call is made your handler function may be invoked. Since
1604 * your handler function must clear any interrupt the board
1605 * raises, you must take care both to initialise your hardware
1606 * and to set up the interrupt handler in the right order.
1608 * If you want to set up a threaded irq handler for your device
1609 * then you need to supply @handler and @thread_fn. @handler is
1610 * still called in hard interrupt context and has to check
1611 * whether the interrupt originates from the device. If yes it
1612 * needs to disable the interrupt on the device and return
1613 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1614 * @thread_fn. This split handler design is necessary to support
1615 * shared interrupts.
1617 * Dev_id must be globally unique. Normally the address of the
1618 * device data structure is used as the cookie. Since the handler
1619 * receives this value it makes sense to use it.
1621 * If your interrupt is shared you must pass a non NULL dev_id
1622 * as this is required when freeing the interrupt.
1626 * IRQF_SHARED Interrupt is shared
1627 * IRQF_TRIGGER_* Specify active edge(s) or level
1630 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1631 irq_handler_t thread_fn, unsigned long irqflags,
1632 const char *devname, void *dev_id)
1634 struct irqaction *action;
1635 struct irq_desc *desc;
1639 * Sanity-check: shared interrupts must pass in a real dev-ID,
1640 * otherwise we'll have trouble later trying to figure out
1641 * which interrupt is which (messes up the interrupt freeing
1644 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1645 * it cannot be set along with IRQF_NO_SUSPEND.
1647 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1648 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1649 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1652 desc = irq_to_desc(irq);
1656 if (!irq_settings_can_request(desc) ||
1657 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1663 handler = irq_default_primary_handler;
1666 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1670 action->handler = handler;
1671 action->thread_fn = thread_fn;
1672 action->flags = irqflags;
1673 action->name = devname;
1674 action->dev_id = dev_id;
1676 chip_bus_lock(desc);
1677 retval = __setup_irq(irq, desc, action);
1678 chip_bus_sync_unlock(desc);
1681 kfree(action->secondary);
1685 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1686 if (!retval && (irqflags & IRQF_SHARED)) {
1688 * It's a shared IRQ -- the driver ought to be prepared for it
1689 * to happen immediately, so let's make sure....
1690 * We disable the irq to make sure that a 'real' IRQ doesn't
1691 * run in parallel with our fake.
1693 unsigned long flags;
1696 local_irq_save(flags);
1698 handler(irq, dev_id);
1700 local_irq_restore(flags);
1706 EXPORT_SYMBOL(request_threaded_irq);
1709 * request_any_context_irq - allocate an interrupt line
1710 * @irq: Interrupt line to allocate
1711 * @handler: Function to be called when the IRQ occurs.
1712 * Threaded handler for threaded interrupts.
1713 * @flags: Interrupt type flags
1714 * @name: An ascii name for the claiming device
1715 * @dev_id: A cookie passed back to the handler function
1717 * This call allocates interrupt resources and enables the
1718 * interrupt line and IRQ handling. It selects either a
1719 * hardirq or threaded handling method depending on the
1722 * On failure, it returns a negative value. On success,
1723 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1725 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1726 unsigned long flags, const char *name, void *dev_id)
1728 struct irq_desc *desc = irq_to_desc(irq);
1734 if (irq_settings_is_nested_thread(desc)) {
1735 ret = request_threaded_irq(irq, NULL, handler,
1736 flags, name, dev_id);
1737 return !ret ? IRQC_IS_NESTED : ret;
1740 ret = request_irq(irq, handler, flags, name, dev_id);
1741 return !ret ? IRQC_IS_HARDIRQ : ret;
1743 EXPORT_SYMBOL_GPL(request_any_context_irq);
1745 void enable_percpu_irq(unsigned int irq, unsigned int type)
1747 unsigned int cpu = smp_processor_id();
1748 unsigned long flags;
1749 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1754 type &= IRQ_TYPE_SENSE_MASK;
1755 if (type != IRQ_TYPE_NONE) {
1758 ret = __irq_set_trigger(desc, type);
1761 WARN(1, "failed to set type for IRQ%d\n", irq);
1766 irq_percpu_enable(desc, cpu);
1768 irq_put_desc_unlock(desc, flags);
1770 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1772 void disable_percpu_irq(unsigned int irq)
1774 unsigned int cpu = smp_processor_id();
1775 unsigned long flags;
1776 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1781 irq_percpu_disable(desc, cpu);
1782 irq_put_desc_unlock(desc, flags);
1784 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1787 * Internal function to unregister a percpu irqaction.
1789 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1791 struct irq_desc *desc = irq_to_desc(irq);
1792 struct irqaction *action;
1793 unsigned long flags;
1795 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1800 raw_spin_lock_irqsave(&desc->lock, flags);
1802 action = desc->action;
1803 if (!action || action->percpu_dev_id != dev_id) {
1804 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1808 if (!cpumask_empty(desc->percpu_enabled)) {
1809 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1810 irq, cpumask_first(desc->percpu_enabled));
1814 /* Found it - now remove it from the list of entries: */
1815 desc->action = NULL;
1817 raw_spin_unlock_irqrestore(&desc->lock, flags);
1819 unregister_handler_proc(irq, action);
1821 module_put(desc->owner);
1825 raw_spin_unlock_irqrestore(&desc->lock, flags);
1830 * remove_percpu_irq - free a per-cpu interrupt
1831 * @irq: Interrupt line to free
1832 * @act: irqaction for the interrupt
1834 * Used to remove interrupts statically setup by the early boot process.
1836 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1838 struct irq_desc *desc = irq_to_desc(irq);
1840 if (desc && irq_settings_is_per_cpu_devid(desc))
1841 __free_percpu_irq(irq, act->percpu_dev_id);
1845 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1846 * @irq: Interrupt line to free
1847 * @dev_id: Device identity to free
1849 * Remove a percpu interrupt handler. The handler is removed, but
1850 * the interrupt line is not disabled. This must be done on each
1851 * CPU before calling this function. The function does not return
1852 * until any executing interrupts for this IRQ have completed.
1854 * This function must not be called from interrupt context.
1856 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1858 struct irq_desc *desc = irq_to_desc(irq);
1860 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1863 chip_bus_lock(desc);
1864 kfree(__free_percpu_irq(irq, dev_id));
1865 chip_bus_sync_unlock(desc);
1867 EXPORT_SYMBOL_GPL(free_percpu_irq);
1870 * setup_percpu_irq - setup a per-cpu interrupt
1871 * @irq: Interrupt line to setup
1872 * @act: irqaction for the interrupt
1874 * Used to statically setup per-cpu interrupts in the early boot process.
1876 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1878 struct irq_desc *desc = irq_to_desc(irq);
1881 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1883 chip_bus_lock(desc);
1884 retval = __setup_irq(irq, desc, act);
1885 chip_bus_sync_unlock(desc);
1891 * request_percpu_irq - allocate a percpu interrupt line
1892 * @irq: Interrupt line to allocate
1893 * @handler: Function to be called when the IRQ occurs.
1894 * @devname: An ascii name for the claiming device
1895 * @dev_id: A percpu cookie passed back to the handler function
1897 * This call allocates interrupt resources and enables the
1898 * interrupt on the local CPU. If the interrupt is supposed to be
1899 * enabled on other CPUs, it has to be done on each CPU using
1900 * enable_percpu_irq().
1902 * Dev_id must be globally unique. It is a per-cpu variable, and
1903 * the handler gets called with the interrupted CPU's instance of
1906 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1907 const char *devname, void __percpu *dev_id)
1909 struct irqaction *action;
1910 struct irq_desc *desc;
1916 desc = irq_to_desc(irq);
1917 if (!desc || !irq_settings_can_request(desc) ||
1918 !irq_settings_is_per_cpu_devid(desc))
1921 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1925 action->handler = handler;
1926 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1927 action->name = devname;
1928 action->percpu_dev_id = dev_id;
1930 chip_bus_lock(desc);
1931 retval = __setup_irq(irq, desc, action);
1932 chip_bus_sync_unlock(desc);
1939 EXPORT_SYMBOL_GPL(request_percpu_irq);
1942 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
1943 * @irq: Interrupt line that is forwarded to a VM
1944 * @which: One of IRQCHIP_STATE_* the caller wants to know about
1945 * @state: a pointer to a boolean where the state is to be storeed
1947 * This call snapshots the internal irqchip state of an
1948 * interrupt, returning into @state the bit corresponding to
1951 * This function should be called with preemption disabled if the
1952 * interrupt controller has per-cpu registers.
1954 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
1957 struct irq_desc *desc;
1958 struct irq_data *data;
1959 struct irq_chip *chip;
1960 unsigned long flags;
1963 desc = irq_get_desc_buslock(irq, &flags, 0);
1967 data = irq_desc_get_irq_data(desc);
1970 chip = irq_data_get_irq_chip(data);
1971 if (chip->irq_get_irqchip_state)
1973 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1974 data = data->parent_data;
1981 err = chip->irq_get_irqchip_state(data, which, state);
1983 irq_put_desc_busunlock(desc, flags);
1986 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
1989 * irq_set_irqchip_state - set the state of a forwarded interrupt.
1990 * @irq: Interrupt line that is forwarded to a VM
1991 * @which: State to be restored (one of IRQCHIP_STATE_*)
1992 * @val: Value corresponding to @which
1994 * This call sets the internal irqchip state of an interrupt,
1995 * depending on the value of @which.
1997 * This function should be called with preemption disabled if the
1998 * interrupt controller has per-cpu registers.
2000 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2003 struct irq_desc *desc;
2004 struct irq_data *data;
2005 struct irq_chip *chip;
2006 unsigned long flags;
2009 desc = irq_get_desc_buslock(irq, &flags, 0);
2013 data = irq_desc_get_irq_data(desc);
2016 chip = irq_data_get_irq_chip(data);
2017 if (chip->irq_set_irqchip_state)
2019 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2020 data = data->parent_data;
2027 err = chip->irq_set_irqchip_state(data, which, val);
2029 irq_put_desc_busunlock(desc, flags);
2032 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);