1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
6 * This file contains driver APIs to the irq subsystem.
9 #define pr_fmt(fmt) "genirq: " fmt
11 #include <linux/irq.h>
12 #include <linux/kthread.h>
13 #include <linux/module.h>
14 #include <linux/random.h>
15 #include <linux/interrupt.h>
16 #include <linux/slab.h>
17 #include <linux/sched.h>
18 #include <linux/sched/rt.h>
19 #include <linux/sched/task.h>
20 #include <uapi/linux/sched/types.h>
21 #include <linux/task_work.h>
23 #include "internals.h"
25 #ifdef CONFIG_IRQ_FORCED_THREADING
26 __read_mostly bool force_irqthreads;
27 EXPORT_SYMBOL_GPL(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 static void irq_validate_effective_affinity(struct irq_data *data)
173 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
174 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
175 struct irq_chip *chip = irq_data_get_irq_chip(data);
177 if (!cpumask_empty(m))
179 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
180 chip->name, data->irq);
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 if (!chip || !chip->irq_set_affinity)
194 ret = chip->irq_set_affinity(data, mask, force);
196 case IRQ_SET_MASK_OK:
197 case IRQ_SET_MASK_OK_DONE:
198 cpumask_copy(desc->irq_common_data.affinity, mask);
199 case IRQ_SET_MASK_OK_NOCOPY:
200 irq_validate_effective_affinity(data);
201 irq_set_thread_affinity(desc);
208 #ifdef CONFIG_GENERIC_PENDING_IRQ
209 static inline int irq_set_affinity_pending(struct irq_data *data,
210 const struct cpumask *dest)
212 struct irq_desc *desc = irq_data_to_desc(data);
214 irqd_set_move_pending(data);
215 irq_copy_pending(desc, dest);
219 static inline int irq_set_affinity_pending(struct irq_data *data,
220 const struct cpumask *dest)
226 static int irq_try_set_affinity(struct irq_data *data,
227 const struct cpumask *dest, bool force)
229 int ret = irq_do_set_affinity(data, dest, force);
232 * In case that the underlying vector management is busy and the
233 * architecture supports the generic pending mechanism then utilize
234 * this to avoid returning an error to user space.
236 if (ret == -EBUSY && !force)
237 ret = irq_set_affinity_pending(data, dest);
241 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
244 struct irq_chip *chip = irq_data_get_irq_chip(data);
245 struct irq_desc *desc = irq_data_to_desc(data);
248 if (!chip || !chip->irq_set_affinity)
251 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
252 ret = irq_try_set_affinity(data, mask, force);
254 irqd_set_move_pending(data);
255 irq_copy_pending(desc, mask);
258 if (desc->affinity_notify) {
259 kref_get(&desc->affinity_notify->kref);
260 schedule_work(&desc->affinity_notify->work);
262 irqd_set(data, IRQD_AFFINITY_SET);
267 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
269 struct irq_desc *desc = irq_to_desc(irq);
276 raw_spin_lock_irqsave(&desc->lock, flags);
277 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
278 raw_spin_unlock_irqrestore(&desc->lock, flags);
282 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
285 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
289 desc->affinity_hint = m;
290 irq_put_desc_unlock(desc, flags);
291 /* set the initial affinity to prevent every interrupt being on CPU0 */
293 __irq_set_affinity(irq, m, false);
296 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
298 static void irq_affinity_notify(struct work_struct *work)
300 struct irq_affinity_notify *notify =
301 container_of(work, struct irq_affinity_notify, work);
302 struct irq_desc *desc = irq_to_desc(notify->irq);
303 cpumask_var_t cpumask;
306 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
309 raw_spin_lock_irqsave(&desc->lock, flags);
310 if (irq_move_pending(&desc->irq_data))
311 irq_get_pending(cpumask, desc);
313 cpumask_copy(cpumask, desc->irq_common_data.affinity);
314 raw_spin_unlock_irqrestore(&desc->lock, flags);
316 notify->notify(notify, cpumask);
318 free_cpumask_var(cpumask);
320 kref_put(¬ify->kref, notify->release);
324 * irq_set_affinity_notifier - control notification of IRQ affinity changes
325 * @irq: Interrupt for which to enable/disable notification
326 * @notify: Context for notification, or %NULL to disable
327 * notification. Function pointers must be initialised;
328 * the other fields will be initialised by this function.
330 * Must be called in process context. Notification may only be enabled
331 * after the IRQ is allocated and must be disabled before the IRQ is
332 * freed using free_irq().
335 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
337 struct irq_desc *desc = irq_to_desc(irq);
338 struct irq_affinity_notify *old_notify;
341 /* The release function is promised process context */
347 /* Complete initialisation of *notify */
350 kref_init(¬ify->kref);
351 INIT_WORK(¬ify->work, irq_affinity_notify);
354 raw_spin_lock_irqsave(&desc->lock, flags);
355 old_notify = desc->affinity_notify;
356 desc->affinity_notify = notify;
357 raw_spin_unlock_irqrestore(&desc->lock, flags);
360 kref_put(&old_notify->kref, old_notify->release);
364 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
366 #ifndef CONFIG_AUTO_IRQ_AFFINITY
368 * Generic version of the affinity autoselector.
370 int irq_setup_affinity(struct irq_desc *desc)
372 struct cpumask *set = irq_default_affinity;
373 int ret, node = irq_desc_get_node(desc);
374 static DEFINE_RAW_SPINLOCK(mask_lock);
375 static struct cpumask mask;
377 /* Excludes PER_CPU and NO_BALANCE interrupts */
378 if (!__irq_can_set_affinity(desc))
381 raw_spin_lock(&mask_lock);
383 * Preserve the managed affinity setting and a userspace affinity
384 * setup, but make sure that one of the targets is online.
386 if (irqd_affinity_is_managed(&desc->irq_data) ||
387 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
388 if (cpumask_intersects(desc->irq_common_data.affinity,
390 set = desc->irq_common_data.affinity;
392 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
395 cpumask_and(&mask, cpu_online_mask, set);
396 if (cpumask_empty(&mask))
397 cpumask_copy(&mask, cpu_online_mask);
399 if (node != NUMA_NO_NODE) {
400 const struct cpumask *nodemask = cpumask_of_node(node);
402 /* make sure at least one of the cpus in nodemask is online */
403 if (cpumask_intersects(&mask, nodemask))
404 cpumask_and(&mask, &mask, nodemask);
406 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
407 raw_spin_unlock(&mask_lock);
411 /* Wrapper for ALPHA specific affinity selector magic */
412 int irq_setup_affinity(struct irq_desc *desc)
414 return irq_select_affinity(irq_desc_get_irq(desc));
419 * Called when a bogus affinity is set via /proc/irq
421 int irq_select_affinity_usr(unsigned int irq)
423 struct irq_desc *desc = irq_to_desc(irq);
427 raw_spin_lock_irqsave(&desc->lock, flags);
428 ret = irq_setup_affinity(desc);
429 raw_spin_unlock_irqrestore(&desc->lock, flags);
435 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
436 * @irq: interrupt number to set affinity
437 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
438 * specific data for percpu_devid interrupts
440 * This function uses the vCPU specific data to set the vCPU
441 * affinity for an irq. The vCPU specific data is passed from
442 * outside, such as KVM. One example code path is as below:
443 * KVM -> IOMMU -> irq_set_vcpu_affinity().
445 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
448 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
449 struct irq_data *data;
450 struct irq_chip *chip;
456 data = irq_desc_get_irq_data(desc);
458 chip = irq_data_get_irq_chip(data);
459 if (chip && chip->irq_set_vcpu_affinity)
461 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
462 data = data->parent_data;
469 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
470 irq_put_desc_unlock(desc, flags);
474 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
476 void __disable_irq(struct irq_desc *desc)
482 static int __disable_irq_nosync(unsigned int irq)
485 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
490 irq_put_desc_busunlock(desc, flags);
495 * disable_irq_nosync - disable an irq without waiting
496 * @irq: Interrupt to disable
498 * Disable the selected interrupt line. Disables and Enables are
500 * Unlike disable_irq(), this function does not ensure existing
501 * instances of the IRQ handler have completed before returning.
503 * This function may be called from IRQ context.
505 void disable_irq_nosync(unsigned int irq)
507 __disable_irq_nosync(irq);
509 EXPORT_SYMBOL(disable_irq_nosync);
512 * disable_irq - disable an irq and wait for completion
513 * @irq: Interrupt to disable
515 * Disable the selected interrupt line. Enables and Disables are
517 * This function waits for any pending IRQ handlers for this interrupt
518 * to complete before returning. If you use this function while
519 * holding a resource the IRQ handler may need you will deadlock.
521 * This function may be called - with care - from IRQ context.
523 void disable_irq(unsigned int irq)
525 if (!__disable_irq_nosync(irq))
526 synchronize_irq(irq);
528 EXPORT_SYMBOL(disable_irq);
531 * disable_hardirq - disables an irq and waits for hardirq completion
532 * @irq: Interrupt to disable
534 * Disable the selected interrupt line. Enables and Disables are
536 * This function waits for any pending hard IRQ handlers for this
537 * interrupt to complete before returning. If you use this function while
538 * holding a resource the hard IRQ handler may need you will deadlock.
540 * When used to optimistically disable an interrupt from atomic context
541 * the return value must be checked.
543 * Returns: false if a threaded handler is active.
545 * This function may be called - with care - from IRQ context.
547 bool disable_hardirq(unsigned int irq)
549 if (!__disable_irq_nosync(irq))
550 return synchronize_hardirq(irq);
554 EXPORT_SYMBOL_GPL(disable_hardirq);
556 void __enable_irq(struct irq_desc *desc)
558 switch (desc->depth) {
561 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
562 irq_desc_get_irq(desc));
565 if (desc->istate & IRQS_SUSPENDED)
567 /* Prevent probing on this irq: */
568 irq_settings_set_noprobe(desc);
570 * Call irq_startup() not irq_enable() here because the
571 * interrupt might be marked NOAUTOEN. So irq_startup()
572 * needs to be invoked when it gets enabled the first
573 * time. If it was already started up, then irq_startup()
574 * will invoke irq_enable() under the hood.
576 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
585 * enable_irq - enable handling of an irq
586 * @irq: Interrupt to enable
588 * Undoes the effect of one call to disable_irq(). If this
589 * matches the last disable, processing of interrupts on this
590 * IRQ line is re-enabled.
592 * This function may be called from IRQ context only when
593 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
595 void enable_irq(unsigned int irq)
598 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
602 if (WARN(!desc->irq_data.chip,
603 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
608 irq_put_desc_busunlock(desc, flags);
610 EXPORT_SYMBOL(enable_irq);
612 static int set_irq_wake_real(unsigned int irq, unsigned int on)
614 struct irq_desc *desc = irq_to_desc(irq);
617 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
620 if (desc->irq_data.chip->irq_set_wake)
621 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
627 * irq_set_irq_wake - control irq power management wakeup
628 * @irq: interrupt to control
629 * @on: enable/disable power management wakeup
631 * Enable/disable power management wakeup mode, which is
632 * disabled by default. Enables and disables must match,
633 * just as they match for non-wakeup mode support.
635 * Wakeup mode lets this IRQ wake the system from sleep
636 * states like "suspend to RAM".
638 int irq_set_irq_wake(unsigned int irq, unsigned int on)
641 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
647 /* wakeup-capable irqs can be shared between drivers that
648 * don't need to have the same sleep mode behaviors.
651 if (desc->wake_depth++ == 0) {
652 ret = set_irq_wake_real(irq, on);
654 desc->wake_depth = 0;
656 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
659 if (desc->wake_depth == 0) {
660 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
661 } else if (--desc->wake_depth == 0) {
662 ret = set_irq_wake_real(irq, on);
664 desc->wake_depth = 1;
666 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
669 irq_put_desc_busunlock(desc, flags);
672 EXPORT_SYMBOL(irq_set_irq_wake);
675 * Internal function that tells the architecture code whether a
676 * particular irq has been exclusively allocated or is available
679 int can_request_irq(unsigned int irq, unsigned long irqflags)
682 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
688 if (irq_settings_can_request(desc)) {
690 irqflags & desc->action->flags & IRQF_SHARED)
693 irq_put_desc_unlock(desc, flags);
697 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
699 struct irq_chip *chip = desc->irq_data.chip;
702 if (!chip || !chip->irq_set_type) {
704 * IRQF_TRIGGER_* but the PIC does not support multiple
707 pr_debug("No set_type function for IRQ %d (%s)\n",
708 irq_desc_get_irq(desc),
709 chip ? (chip->name ? : "unknown") : "unknown");
713 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
714 if (!irqd_irq_masked(&desc->irq_data))
716 if (!irqd_irq_disabled(&desc->irq_data))
720 /* Mask all flags except trigger mode */
721 flags &= IRQ_TYPE_SENSE_MASK;
722 ret = chip->irq_set_type(&desc->irq_data, flags);
725 case IRQ_SET_MASK_OK:
726 case IRQ_SET_MASK_OK_DONE:
727 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
728 irqd_set(&desc->irq_data, flags);
730 case IRQ_SET_MASK_OK_NOCOPY:
731 flags = irqd_get_trigger_type(&desc->irq_data);
732 irq_settings_set_trigger_mask(desc, flags);
733 irqd_clear(&desc->irq_data, IRQD_LEVEL);
734 irq_settings_clr_level(desc);
735 if (flags & IRQ_TYPE_LEVEL_MASK) {
736 irq_settings_set_level(desc);
737 irqd_set(&desc->irq_data, IRQD_LEVEL);
743 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
744 flags, irq_desc_get_irq(desc), chip->irq_set_type);
751 #ifdef CONFIG_HARDIRQS_SW_RESEND
752 int irq_set_parent(int irq, int parent_irq)
755 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
760 desc->parent_irq = parent_irq;
762 irq_put_desc_unlock(desc, flags);
765 EXPORT_SYMBOL_GPL(irq_set_parent);
769 * Default primary interrupt handler for threaded interrupts. Is
770 * assigned as primary handler when request_threaded_irq is called
771 * with handler == NULL. Useful for oneshot interrupts.
773 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
775 return IRQ_WAKE_THREAD;
779 * Primary handler for nested threaded interrupts. Should never be
782 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
784 WARN(1, "Primary handler called for nested irq %d\n", irq);
788 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
790 WARN(1, "Secondary action handler called for irq %d\n", irq);
794 static int irq_wait_for_interrupt(struct irqaction *action)
797 set_current_state(TASK_INTERRUPTIBLE);
799 if (kthread_should_stop()) {
800 /* may need to run one last time */
801 if (test_and_clear_bit(IRQTF_RUNTHREAD,
802 &action->thread_flags)) {
803 __set_current_state(TASK_RUNNING);
806 __set_current_state(TASK_RUNNING);
810 if (test_and_clear_bit(IRQTF_RUNTHREAD,
811 &action->thread_flags)) {
812 __set_current_state(TASK_RUNNING);
820 * Oneshot interrupts keep the irq line masked until the threaded
821 * handler finished. unmask if the interrupt has not been disabled and
824 static void irq_finalize_oneshot(struct irq_desc *desc,
825 struct irqaction *action)
827 if (!(desc->istate & IRQS_ONESHOT) ||
828 action->handler == irq_forced_secondary_handler)
832 raw_spin_lock_irq(&desc->lock);
835 * Implausible though it may be we need to protect us against
836 * the following scenario:
838 * The thread is faster done than the hard interrupt handler
839 * on the other CPU. If we unmask the irq line then the
840 * interrupt can come in again and masks the line, leaves due
841 * to IRQS_INPROGRESS and the irq line is masked forever.
843 * This also serializes the state of shared oneshot handlers
844 * versus "desc->threads_onehsot |= action->thread_mask;" in
845 * irq_wake_thread(). See the comment there which explains the
848 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
849 raw_spin_unlock_irq(&desc->lock);
850 chip_bus_sync_unlock(desc);
856 * Now check again, whether the thread should run. Otherwise
857 * we would clear the threads_oneshot bit of this thread which
860 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
863 desc->threads_oneshot &= ~action->thread_mask;
865 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
866 irqd_irq_masked(&desc->irq_data))
867 unmask_threaded_irq(desc);
870 raw_spin_unlock_irq(&desc->lock);
871 chip_bus_sync_unlock(desc);
876 * Check whether we need to change the affinity of the interrupt thread.
879 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
884 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
888 * In case we are out of memory we set IRQTF_AFFINITY again and
889 * try again next time
891 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
892 set_bit(IRQTF_AFFINITY, &action->thread_flags);
896 raw_spin_lock_irq(&desc->lock);
898 * This code is triggered unconditionally. Check the affinity
899 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
901 if (cpumask_available(desc->irq_common_data.affinity)) {
902 const struct cpumask *m;
904 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
905 cpumask_copy(mask, m);
909 raw_spin_unlock_irq(&desc->lock);
912 set_cpus_allowed_ptr(current, mask);
913 free_cpumask_var(mask);
917 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
921 * Interrupts which are not explicitly requested as threaded
922 * interrupts rely on the implicit bh/preempt disable of the hard irq
923 * context. So we need to disable bh here to avoid deadlocks and other
927 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
932 ret = action->thread_fn(action->irq, action->dev_id);
933 if (ret == IRQ_HANDLED)
934 atomic_inc(&desc->threads_handled);
936 irq_finalize_oneshot(desc, action);
942 * Interrupts explicitly requested as threaded interrupts want to be
943 * preemtible - many of them need to sleep and wait for slow busses to
946 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
947 struct irqaction *action)
951 ret = action->thread_fn(action->irq, action->dev_id);
952 if (ret == IRQ_HANDLED)
953 atomic_inc(&desc->threads_handled);
955 irq_finalize_oneshot(desc, action);
959 static void wake_threads_waitq(struct irq_desc *desc)
961 if (atomic_dec_and_test(&desc->threads_active))
962 wake_up(&desc->wait_for_threads);
965 static void irq_thread_dtor(struct callback_head *unused)
967 struct task_struct *tsk = current;
968 struct irq_desc *desc;
969 struct irqaction *action;
971 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
974 action = kthread_data(tsk);
976 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
977 tsk->comm, tsk->pid, action->irq);
980 desc = irq_to_desc(action->irq);
982 * If IRQTF_RUNTHREAD is set, we need to decrement
983 * desc->threads_active and wake possible waiters.
985 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
986 wake_threads_waitq(desc);
988 /* Prevent a stale desc->threads_oneshot */
989 irq_finalize_oneshot(desc, action);
992 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
994 struct irqaction *secondary = action->secondary;
996 if (WARN_ON_ONCE(!secondary))
999 raw_spin_lock_irq(&desc->lock);
1000 __irq_wake_thread(desc, secondary);
1001 raw_spin_unlock_irq(&desc->lock);
1005 * Interrupt handler thread
1007 static int irq_thread(void *data)
1009 struct callback_head on_exit_work;
1010 struct irqaction *action = data;
1011 struct irq_desc *desc = irq_to_desc(action->irq);
1012 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1013 struct irqaction *action);
1015 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1016 &action->thread_flags))
1017 handler_fn = irq_forced_thread_fn;
1019 handler_fn = irq_thread_fn;
1021 init_task_work(&on_exit_work, irq_thread_dtor);
1022 task_work_add(current, &on_exit_work, false);
1024 irq_thread_check_affinity(desc, action);
1026 while (!irq_wait_for_interrupt(action)) {
1027 irqreturn_t action_ret;
1029 irq_thread_check_affinity(desc, action);
1031 action_ret = handler_fn(desc, action);
1032 if (action_ret == IRQ_WAKE_THREAD)
1033 irq_wake_secondary(desc, action);
1035 wake_threads_waitq(desc);
1039 * This is the regular exit path. __free_irq() is stopping the
1040 * thread via kthread_stop() after calling
1041 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1042 * oneshot mask bit can be set.
1044 task_work_cancel(current, irq_thread_dtor);
1049 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1050 * @irq: Interrupt line
1051 * @dev_id: Device identity for which the thread should be woken
1054 void irq_wake_thread(unsigned int irq, void *dev_id)
1056 struct irq_desc *desc = irq_to_desc(irq);
1057 struct irqaction *action;
1058 unsigned long flags;
1060 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1063 raw_spin_lock_irqsave(&desc->lock, flags);
1064 for_each_action_of_desc(desc, action) {
1065 if (action->dev_id == dev_id) {
1067 __irq_wake_thread(desc, action);
1071 raw_spin_unlock_irqrestore(&desc->lock, flags);
1073 EXPORT_SYMBOL_GPL(irq_wake_thread);
1075 static int irq_setup_forced_threading(struct irqaction *new)
1077 if (!force_irqthreads)
1079 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1083 * No further action required for interrupts which are requested as
1084 * threaded interrupts already
1086 if (new->handler == irq_default_primary_handler)
1089 new->flags |= IRQF_ONESHOT;
1092 * Handle the case where we have a real primary handler and a
1093 * thread handler. We force thread them as well by creating a
1096 if (new->handler && new->thread_fn) {
1097 /* Allocate the secondary action */
1098 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1099 if (!new->secondary)
1101 new->secondary->handler = irq_forced_secondary_handler;
1102 new->secondary->thread_fn = new->thread_fn;
1103 new->secondary->dev_id = new->dev_id;
1104 new->secondary->irq = new->irq;
1105 new->secondary->name = new->name;
1107 /* Deal with the primary handler */
1108 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1109 new->thread_fn = new->handler;
1110 new->handler = irq_default_primary_handler;
1114 static int irq_request_resources(struct irq_desc *desc)
1116 struct irq_data *d = &desc->irq_data;
1117 struct irq_chip *c = d->chip;
1119 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1122 static void irq_release_resources(struct irq_desc *desc)
1124 struct irq_data *d = &desc->irq_data;
1125 struct irq_chip *c = d->chip;
1127 if (c->irq_release_resources)
1128 c->irq_release_resources(d);
1132 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1134 struct task_struct *t;
1135 struct sched_param param = {
1136 .sched_priority = MAX_USER_RT_PRIO/2,
1140 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1143 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1145 param.sched_priority -= 1;
1151 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1154 * We keep the reference to the task struct even if
1155 * the thread dies to avoid that the interrupt code
1156 * references an already freed task_struct.
1161 * Tell the thread to set its affinity. This is
1162 * important for shared interrupt handlers as we do
1163 * not invoke setup_affinity() for the secondary
1164 * handlers as everything is already set up. Even for
1165 * interrupts marked with IRQF_NO_BALANCE this is
1166 * correct as we want the thread to move to the cpu(s)
1167 * on which the requesting code placed the interrupt.
1169 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1174 * Internal function to register an irqaction - typically used to
1175 * allocate special interrupts that are part of the architecture.
1179 * desc->request_mutex Provides serialization against a concurrent free_irq()
1180 * chip_bus_lock Provides serialization for slow bus operations
1181 * desc->lock Provides serialization against hard interrupts
1183 * chip_bus_lock and desc->lock are sufficient for all other management and
1184 * interrupt related functions. desc->request_mutex solely serializes
1185 * request/free_irq().
1188 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1190 struct irqaction *old, **old_ptr;
1191 unsigned long flags, thread_mask = 0;
1192 int ret, nested, shared = 0;
1197 if (desc->irq_data.chip == &no_irq_chip)
1199 if (!try_module_get(desc->owner))
1205 * If the trigger type is not specified by the caller,
1206 * then use the default for this interrupt.
1208 if (!(new->flags & IRQF_TRIGGER_MASK))
1209 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1212 * Check whether the interrupt nests into another interrupt
1215 nested = irq_settings_is_nested_thread(desc);
1217 if (!new->thread_fn) {
1222 * Replace the primary handler which was provided from
1223 * the driver for non nested interrupt handling by the
1224 * dummy function which warns when called.
1226 new->handler = irq_nested_primary_handler;
1228 if (irq_settings_can_thread(desc)) {
1229 ret = irq_setup_forced_threading(new);
1236 * Create a handler thread when a thread function is supplied
1237 * and the interrupt does not nest into another interrupt
1240 if (new->thread_fn && !nested) {
1241 ret = setup_irq_thread(new, irq, false);
1244 if (new->secondary) {
1245 ret = setup_irq_thread(new->secondary, irq, true);
1252 * Drivers are often written to work w/o knowledge about the
1253 * underlying irq chip implementation, so a request for a
1254 * threaded irq without a primary hard irq context handler
1255 * requires the ONESHOT flag to be set. Some irq chips like
1256 * MSI based interrupts are per se one shot safe. Check the
1257 * chip flags, so we can avoid the unmask dance at the end of
1258 * the threaded handler for those.
1260 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1261 new->flags &= ~IRQF_ONESHOT;
1264 * Protects against a concurrent __free_irq() call which might wait
1265 * for synchronize_hardirq() to complete without holding the optional
1266 * chip bus lock and desc->lock. Also protects against handing out
1267 * a recycled oneshot thread_mask bit while it's still in use by
1268 * its previous owner.
1270 mutex_lock(&desc->request_mutex);
1273 * Acquire bus lock as the irq_request_resources() callback below
1274 * might rely on the serialization or the magic power management
1275 * functions which are abusing the irq_bus_lock() callback,
1277 chip_bus_lock(desc);
1279 /* First installed action requests resources. */
1280 if (!desc->action) {
1281 ret = irq_request_resources(desc);
1283 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1284 new->name, irq, desc->irq_data.chip->name);
1285 goto out_bus_unlock;
1290 * The following block of code has to be executed atomically
1291 * protected against a concurrent interrupt and any of the other
1292 * management calls which are not serialized via
1293 * desc->request_mutex or the optional bus lock.
1295 raw_spin_lock_irqsave(&desc->lock, flags);
1296 old_ptr = &desc->action;
1300 * Can't share interrupts unless both agree to and are
1301 * the same type (level, edge, polarity). So both flag
1302 * fields must have IRQF_SHARED set and the bits which
1303 * set the trigger type must match. Also all must
1306 unsigned int oldtype;
1309 * If nobody did set the configuration before, inherit
1310 * the one provided by the requester.
1312 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1313 oldtype = irqd_get_trigger_type(&desc->irq_data);
1315 oldtype = new->flags & IRQF_TRIGGER_MASK;
1316 irqd_set_trigger_type(&desc->irq_data, oldtype);
1319 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1320 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1321 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1324 /* All handlers must agree on per-cpuness */
1325 if ((old->flags & IRQF_PERCPU) !=
1326 (new->flags & IRQF_PERCPU))
1329 /* add new interrupt at end of irq queue */
1332 * Or all existing action->thread_mask bits,
1333 * so we can find the next zero bit for this
1336 thread_mask |= old->thread_mask;
1337 old_ptr = &old->next;
1344 * Setup the thread mask for this irqaction for ONESHOT. For
1345 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1346 * conditional in irq_wake_thread().
1348 if (new->flags & IRQF_ONESHOT) {
1350 * Unlikely to have 32 resp 64 irqs sharing one line,
1353 if (thread_mask == ~0UL) {
1358 * The thread_mask for the action is or'ed to
1359 * desc->thread_active to indicate that the
1360 * IRQF_ONESHOT thread handler has been woken, but not
1361 * yet finished. The bit is cleared when a thread
1362 * completes. When all threads of a shared interrupt
1363 * line have completed desc->threads_active becomes
1364 * zero and the interrupt line is unmasked. See
1365 * handle.c:irq_wake_thread() for further information.
1367 * If no thread is woken by primary (hard irq context)
1368 * interrupt handlers, then desc->threads_active is
1369 * also checked for zero to unmask the irq line in the
1370 * affected hard irq flow handlers
1371 * (handle_[fasteoi|level]_irq).
1373 * The new action gets the first zero bit of
1374 * thread_mask assigned. See the loop above which or's
1375 * all existing action->thread_mask bits.
1377 new->thread_mask = 1UL << ffz(thread_mask);
1379 } else if (new->handler == irq_default_primary_handler &&
1380 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1382 * The interrupt was requested with handler = NULL, so
1383 * we use the default primary handler for it. But it
1384 * does not have the oneshot flag set. In combination
1385 * with level interrupts this is deadly, because the
1386 * default primary handler just wakes the thread, then
1387 * the irq lines is reenabled, but the device still
1388 * has the level irq asserted. Rinse and repeat....
1390 * While this works for edge type interrupts, we play
1391 * it safe and reject unconditionally because we can't
1392 * say for sure which type this interrupt really
1393 * has. The type flags are unreliable as the
1394 * underlying chip implementation can override them.
1396 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1403 init_waitqueue_head(&desc->wait_for_threads);
1405 /* Setup the type (level, edge polarity) if configured: */
1406 if (new->flags & IRQF_TRIGGER_MASK) {
1407 ret = __irq_set_trigger(desc,
1408 new->flags & IRQF_TRIGGER_MASK);
1415 * Activate the interrupt. That activation must happen
1416 * independently of IRQ_NOAUTOEN. request_irq() can fail
1417 * and the callers are supposed to handle
1418 * that. enable_irq() of an interrupt requested with
1419 * IRQ_NOAUTOEN is not supposed to fail. The activation
1420 * keeps it in shutdown mode, it merily associates
1421 * resources if necessary and if that's not possible it
1422 * fails. Interrupts which are in managed shutdown mode
1423 * will simply ignore that activation request.
1425 ret = irq_activate(desc);
1429 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1430 IRQS_ONESHOT | IRQS_WAITING);
1431 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1433 if (new->flags & IRQF_PERCPU) {
1434 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1435 irq_settings_set_per_cpu(desc);
1438 if (new->flags & IRQF_ONESHOT)
1439 desc->istate |= IRQS_ONESHOT;
1441 /* Exclude IRQ from balancing if requested */
1442 if (new->flags & IRQF_NOBALANCING) {
1443 irq_settings_set_no_balancing(desc);
1444 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1447 if (irq_settings_can_autoenable(desc)) {
1448 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1451 * Shared interrupts do not go well with disabling
1452 * auto enable. The sharing interrupt might request
1453 * it while it's still disabled and then wait for
1454 * interrupts forever.
1456 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1457 /* Undo nested disables: */
1461 } else if (new->flags & IRQF_TRIGGER_MASK) {
1462 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1463 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1466 /* hope the handler works with current trigger mode */
1467 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1473 irq_pm_install_action(desc, new);
1475 /* Reset broken irq detection when installing new handler */
1476 desc->irq_count = 0;
1477 desc->irqs_unhandled = 0;
1480 * Check whether we disabled the irq via the spurious handler
1481 * before. Reenable it and give it another chance.
1483 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1484 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1488 raw_spin_unlock_irqrestore(&desc->lock, flags);
1489 chip_bus_sync_unlock(desc);
1490 mutex_unlock(&desc->request_mutex);
1492 irq_setup_timings(desc, new);
1495 * Strictly no need to wake it up, but hung_task complains
1496 * when no hard interrupt wakes the thread up.
1499 wake_up_process(new->thread);
1501 wake_up_process(new->secondary->thread);
1503 register_irq_proc(irq, desc);
1505 register_handler_proc(irq, new);
1509 if (!(new->flags & IRQF_PROBE_SHARED)) {
1510 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1511 irq, new->flags, new->name, old->flags, old->name);
1512 #ifdef CONFIG_DEBUG_SHIRQ
1519 raw_spin_unlock_irqrestore(&desc->lock, flags);
1522 irq_release_resources(desc);
1524 chip_bus_sync_unlock(desc);
1525 mutex_unlock(&desc->request_mutex);
1529 struct task_struct *t = new->thread;
1535 if (new->secondary && new->secondary->thread) {
1536 struct task_struct *t = new->secondary->thread;
1538 new->secondary->thread = NULL;
1543 module_put(desc->owner);
1548 * setup_irq - setup an interrupt
1549 * @irq: Interrupt line to setup
1550 * @act: irqaction for the interrupt
1552 * Used to statically setup interrupts in the early boot process.
1554 int setup_irq(unsigned int irq, struct irqaction *act)
1557 struct irq_desc *desc = irq_to_desc(irq);
1559 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1562 retval = irq_chip_pm_get(&desc->irq_data);
1566 retval = __setup_irq(irq, desc, act);
1569 irq_chip_pm_put(&desc->irq_data);
1573 EXPORT_SYMBOL_GPL(setup_irq);
1576 * Internal function to unregister an irqaction - used to free
1577 * regular and special interrupts that are part of the architecture.
1579 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1581 unsigned irq = desc->irq_data.irq;
1582 struct irqaction *action, **action_ptr;
1583 unsigned long flags;
1585 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1587 mutex_lock(&desc->request_mutex);
1588 chip_bus_lock(desc);
1589 raw_spin_lock_irqsave(&desc->lock, flags);
1592 * There can be multiple actions per IRQ descriptor, find the right
1593 * one based on the dev_id:
1595 action_ptr = &desc->action;
1597 action = *action_ptr;
1600 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1601 raw_spin_unlock_irqrestore(&desc->lock, flags);
1602 chip_bus_sync_unlock(desc);
1603 mutex_unlock(&desc->request_mutex);
1607 if (action->dev_id == dev_id)
1609 action_ptr = &action->next;
1612 /* Found it - now remove it from the list of entries: */
1613 *action_ptr = action->next;
1615 irq_pm_remove_action(desc, action);
1617 /* If this was the last handler, shut down the IRQ line: */
1618 if (!desc->action) {
1619 irq_settings_clr_disable_unlazy(desc);
1624 /* make sure affinity_hint is cleaned up */
1625 if (WARN_ON_ONCE(desc->affinity_hint))
1626 desc->affinity_hint = NULL;
1629 raw_spin_unlock_irqrestore(&desc->lock, flags);
1631 * Drop bus_lock here so the changes which were done in the chip
1632 * callbacks above are synced out to the irq chips which hang
1633 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1635 * Aside of that the bus_lock can also be taken from the threaded
1636 * handler in irq_finalize_oneshot() which results in a deadlock
1637 * because kthread_stop() would wait forever for the thread to
1638 * complete, which is blocked on the bus lock.
1640 * The still held desc->request_mutex() protects against a
1641 * concurrent request_irq() of this irq so the release of resources
1642 * and timing data is properly serialized.
1644 chip_bus_sync_unlock(desc);
1646 unregister_handler_proc(irq, action);
1648 /* Make sure it's not being used on another CPU: */
1649 synchronize_hardirq(irq);
1651 #ifdef CONFIG_DEBUG_SHIRQ
1653 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1654 * event to happen even now it's being freed, so let's make sure that
1655 * is so by doing an extra call to the handler ....
1657 * ( We do this after actually deregistering it, to make sure that a
1658 * 'real' IRQ doesn't run in parallel with our fake. )
1660 if (action->flags & IRQF_SHARED) {
1661 local_irq_save(flags);
1662 action->handler(irq, dev_id);
1663 local_irq_restore(flags);
1668 * The action has already been removed above, but the thread writes
1669 * its oneshot mask bit when it completes. Though request_mutex is
1670 * held across this which prevents __setup_irq() from handing out
1671 * the same bit to a newly requested action.
1673 if (action->thread) {
1674 kthread_stop(action->thread);
1675 put_task_struct(action->thread);
1676 if (action->secondary && action->secondary->thread) {
1677 kthread_stop(action->secondary->thread);
1678 put_task_struct(action->secondary->thread);
1682 /* Last action releases resources */
1683 if (!desc->action) {
1685 * Reaquire bus lock as irq_release_resources() might
1686 * require it to deallocate resources over the slow bus.
1688 chip_bus_lock(desc);
1689 irq_release_resources(desc);
1690 chip_bus_sync_unlock(desc);
1691 irq_remove_timings(desc);
1694 mutex_unlock(&desc->request_mutex);
1696 irq_chip_pm_put(&desc->irq_data);
1697 module_put(desc->owner);
1698 kfree(action->secondary);
1703 * remove_irq - free an interrupt
1704 * @irq: Interrupt line to free
1705 * @act: irqaction for the interrupt
1707 * Used to remove interrupts statically setup by the early boot process.
1709 void remove_irq(unsigned int irq, struct irqaction *act)
1711 struct irq_desc *desc = irq_to_desc(irq);
1713 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1714 __free_irq(desc, act->dev_id);
1716 EXPORT_SYMBOL_GPL(remove_irq);
1719 * free_irq - free an interrupt allocated with request_irq
1720 * @irq: Interrupt line to free
1721 * @dev_id: Device identity to free
1723 * Remove an interrupt handler. The handler is removed and if the
1724 * interrupt line is no longer in use by any driver it is disabled.
1725 * On a shared IRQ the caller must ensure the interrupt is disabled
1726 * on the card it drives before calling this function. The function
1727 * does not return until any executing interrupts for this IRQ
1730 * This function must not be called from interrupt context.
1732 * Returns the devname argument passed to request_irq.
1734 const void *free_irq(unsigned int irq, void *dev_id)
1736 struct irq_desc *desc = irq_to_desc(irq);
1737 struct irqaction *action;
1738 const char *devname;
1740 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1744 if (WARN_ON(desc->affinity_notify))
1745 desc->affinity_notify = NULL;
1748 action = __free_irq(desc, dev_id);
1753 devname = action->name;
1757 EXPORT_SYMBOL(free_irq);
1760 * request_threaded_irq - allocate an interrupt line
1761 * @irq: Interrupt line to allocate
1762 * @handler: Function to be called when the IRQ occurs.
1763 * Primary handler for threaded interrupts
1764 * If NULL and thread_fn != NULL the default
1765 * primary handler is installed
1766 * @thread_fn: Function called from the irq handler thread
1767 * If NULL, no irq thread is created
1768 * @irqflags: Interrupt type flags
1769 * @devname: An ascii name for the claiming device
1770 * @dev_id: A cookie passed back to the handler function
1772 * This call allocates interrupt resources and enables the
1773 * interrupt line and IRQ handling. From the point this
1774 * call is made your handler function may be invoked. Since
1775 * your handler function must clear any interrupt the board
1776 * raises, you must take care both to initialise your hardware
1777 * and to set up the interrupt handler in the right order.
1779 * If you want to set up a threaded irq handler for your device
1780 * then you need to supply @handler and @thread_fn. @handler is
1781 * still called in hard interrupt context and has to check
1782 * whether the interrupt originates from the device. If yes it
1783 * needs to disable the interrupt on the device and return
1784 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1785 * @thread_fn. This split handler design is necessary to support
1786 * shared interrupts.
1788 * Dev_id must be globally unique. Normally the address of the
1789 * device data structure is used as the cookie. Since the handler
1790 * receives this value it makes sense to use it.
1792 * If your interrupt is shared you must pass a non NULL dev_id
1793 * as this is required when freeing the interrupt.
1797 * IRQF_SHARED Interrupt is shared
1798 * IRQF_TRIGGER_* Specify active edge(s) or level
1801 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1802 irq_handler_t thread_fn, unsigned long irqflags,
1803 const char *devname, void *dev_id)
1805 struct irqaction *action;
1806 struct irq_desc *desc;
1809 if (irq == IRQ_NOTCONNECTED)
1813 * Sanity-check: shared interrupts must pass in a real dev-ID,
1814 * otherwise we'll have trouble later trying to figure out
1815 * which interrupt is which (messes up the interrupt freeing
1818 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1819 * it cannot be set along with IRQF_NO_SUSPEND.
1821 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1822 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1823 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1826 desc = irq_to_desc(irq);
1830 if (!irq_settings_can_request(desc) ||
1831 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1837 handler = irq_default_primary_handler;
1840 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1844 action->handler = handler;
1845 action->thread_fn = thread_fn;
1846 action->flags = irqflags;
1847 action->name = devname;
1848 action->dev_id = dev_id;
1850 retval = irq_chip_pm_get(&desc->irq_data);
1856 retval = __setup_irq(irq, desc, action);
1859 irq_chip_pm_put(&desc->irq_data);
1860 kfree(action->secondary);
1864 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1865 if (!retval && (irqflags & IRQF_SHARED)) {
1867 * It's a shared IRQ -- the driver ought to be prepared for it
1868 * to happen immediately, so let's make sure....
1869 * We disable the irq to make sure that a 'real' IRQ doesn't
1870 * run in parallel with our fake.
1872 unsigned long flags;
1875 local_irq_save(flags);
1877 handler(irq, dev_id);
1879 local_irq_restore(flags);
1885 EXPORT_SYMBOL(request_threaded_irq);
1888 * request_any_context_irq - allocate an interrupt line
1889 * @irq: Interrupt line to allocate
1890 * @handler: Function to be called when the IRQ occurs.
1891 * Threaded handler for threaded interrupts.
1892 * @flags: Interrupt type flags
1893 * @name: An ascii name for the claiming device
1894 * @dev_id: A cookie passed back to the handler function
1896 * This call allocates interrupt resources and enables the
1897 * interrupt line and IRQ handling. It selects either a
1898 * hardirq or threaded handling method depending on the
1901 * On failure, it returns a negative value. On success,
1902 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1904 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1905 unsigned long flags, const char *name, void *dev_id)
1907 struct irq_desc *desc;
1910 if (irq == IRQ_NOTCONNECTED)
1913 desc = irq_to_desc(irq);
1917 if (irq_settings_is_nested_thread(desc)) {
1918 ret = request_threaded_irq(irq, NULL, handler,
1919 flags, name, dev_id);
1920 return !ret ? IRQC_IS_NESTED : ret;
1923 ret = request_irq(irq, handler, flags, name, dev_id);
1924 return !ret ? IRQC_IS_HARDIRQ : ret;
1926 EXPORT_SYMBOL_GPL(request_any_context_irq);
1928 void enable_percpu_irq(unsigned int irq, unsigned int type)
1930 unsigned int cpu = smp_processor_id();
1931 unsigned long flags;
1932 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1938 * If the trigger type is not specified by the caller, then
1939 * use the default for this interrupt.
1941 type &= IRQ_TYPE_SENSE_MASK;
1942 if (type == IRQ_TYPE_NONE)
1943 type = irqd_get_trigger_type(&desc->irq_data);
1945 if (type != IRQ_TYPE_NONE) {
1948 ret = __irq_set_trigger(desc, type);
1951 WARN(1, "failed to set type for IRQ%d\n", irq);
1956 irq_percpu_enable(desc, cpu);
1958 irq_put_desc_unlock(desc, flags);
1960 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1963 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1964 * @irq: Linux irq number to check for
1966 * Must be called from a non migratable context. Returns the enable
1967 * state of a per cpu interrupt on the current cpu.
1969 bool irq_percpu_is_enabled(unsigned int irq)
1971 unsigned int cpu = smp_processor_id();
1972 struct irq_desc *desc;
1973 unsigned long flags;
1976 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1980 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1981 irq_put_desc_unlock(desc, flags);
1985 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1987 void disable_percpu_irq(unsigned int irq)
1989 unsigned int cpu = smp_processor_id();
1990 unsigned long flags;
1991 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1996 irq_percpu_disable(desc, cpu);
1997 irq_put_desc_unlock(desc, flags);
1999 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2002 * Internal function to unregister a percpu irqaction.
2004 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2006 struct irq_desc *desc = irq_to_desc(irq);
2007 struct irqaction *action;
2008 unsigned long flags;
2010 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2015 raw_spin_lock_irqsave(&desc->lock, flags);
2017 action = desc->action;
2018 if (!action || action->percpu_dev_id != dev_id) {
2019 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2023 if (!cpumask_empty(desc->percpu_enabled)) {
2024 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2025 irq, cpumask_first(desc->percpu_enabled));
2029 /* Found it - now remove it from the list of entries: */
2030 desc->action = NULL;
2032 raw_spin_unlock_irqrestore(&desc->lock, flags);
2034 unregister_handler_proc(irq, action);
2036 irq_chip_pm_put(&desc->irq_data);
2037 module_put(desc->owner);
2041 raw_spin_unlock_irqrestore(&desc->lock, flags);
2046 * remove_percpu_irq - free a per-cpu interrupt
2047 * @irq: Interrupt line to free
2048 * @act: irqaction for the interrupt
2050 * Used to remove interrupts statically setup by the early boot process.
2052 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2054 struct irq_desc *desc = irq_to_desc(irq);
2056 if (desc && irq_settings_is_per_cpu_devid(desc))
2057 __free_percpu_irq(irq, act->percpu_dev_id);
2061 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2062 * @irq: Interrupt line to free
2063 * @dev_id: Device identity to free
2065 * Remove a percpu interrupt handler. The handler is removed, but
2066 * the interrupt line is not disabled. This must be done on each
2067 * CPU before calling this function. The function does not return
2068 * until any executing interrupts for this IRQ have completed.
2070 * This function must not be called from interrupt context.
2072 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2074 struct irq_desc *desc = irq_to_desc(irq);
2076 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2079 chip_bus_lock(desc);
2080 kfree(__free_percpu_irq(irq, dev_id));
2081 chip_bus_sync_unlock(desc);
2083 EXPORT_SYMBOL_GPL(free_percpu_irq);
2086 * setup_percpu_irq - setup a per-cpu interrupt
2087 * @irq: Interrupt line to setup
2088 * @act: irqaction for the interrupt
2090 * Used to statically setup per-cpu interrupts in the early boot process.
2092 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2094 struct irq_desc *desc = irq_to_desc(irq);
2097 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2100 retval = irq_chip_pm_get(&desc->irq_data);
2104 retval = __setup_irq(irq, desc, act);
2107 irq_chip_pm_put(&desc->irq_data);
2113 * __request_percpu_irq - allocate a percpu interrupt line
2114 * @irq: Interrupt line to allocate
2115 * @handler: Function to be called when the IRQ occurs.
2116 * @flags: Interrupt type flags (IRQF_TIMER only)
2117 * @devname: An ascii name for the claiming device
2118 * @dev_id: A percpu cookie passed back to the handler function
2120 * This call allocates interrupt resources and enables the
2121 * interrupt on the local CPU. If the interrupt is supposed to be
2122 * enabled on other CPUs, it has to be done on each CPU using
2123 * enable_percpu_irq().
2125 * Dev_id must be globally unique. It is a per-cpu variable, and
2126 * the handler gets called with the interrupted CPU's instance of
2129 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2130 unsigned long flags, const char *devname,
2131 void __percpu *dev_id)
2133 struct irqaction *action;
2134 struct irq_desc *desc;
2140 desc = irq_to_desc(irq);
2141 if (!desc || !irq_settings_can_request(desc) ||
2142 !irq_settings_is_per_cpu_devid(desc))
2145 if (flags && flags != IRQF_TIMER)
2148 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2152 action->handler = handler;
2153 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2154 action->name = devname;
2155 action->percpu_dev_id = dev_id;
2157 retval = irq_chip_pm_get(&desc->irq_data);
2163 retval = __setup_irq(irq, desc, action);
2166 irq_chip_pm_put(&desc->irq_data);
2172 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2175 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2176 * @irq: Interrupt line that is forwarded to a VM
2177 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2178 * @state: a pointer to a boolean where the state is to be storeed
2180 * This call snapshots the internal irqchip state of an
2181 * interrupt, returning into @state the bit corresponding to
2184 * This function should be called with preemption disabled if the
2185 * interrupt controller has per-cpu registers.
2187 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2190 struct irq_desc *desc;
2191 struct irq_data *data;
2192 struct irq_chip *chip;
2193 unsigned long flags;
2196 desc = irq_get_desc_buslock(irq, &flags, 0);
2200 data = irq_desc_get_irq_data(desc);
2203 chip = irq_data_get_irq_chip(data);
2204 if (chip->irq_get_irqchip_state)
2206 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2207 data = data->parent_data;
2214 err = chip->irq_get_irqchip_state(data, which, state);
2216 irq_put_desc_busunlock(desc, flags);
2219 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2222 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2223 * @irq: Interrupt line that is forwarded to a VM
2224 * @which: State to be restored (one of IRQCHIP_STATE_*)
2225 * @val: Value corresponding to @which
2227 * This call sets the internal irqchip state of an interrupt,
2228 * depending on the value of @which.
2230 * This function should be called with preemption disabled if the
2231 * interrupt controller has per-cpu registers.
2233 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2236 struct irq_desc *desc;
2237 struct irq_data *data;
2238 struct irq_chip *chip;
2239 unsigned long flags;
2242 desc = irq_get_desc_buslock(irq, &flags, 0);
2246 data = irq_desc_get_irq_data(desc);
2249 chip = irq_data_get_irq_chip(data);
2250 if (chip->irq_set_irqchip_state)
2252 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2253 data = data->parent_data;
2260 err = chip->irq_set_irqchip_state(data, which, val);
2262 irq_put_desc_busunlock(desc, flags);
2265 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);