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/irqdomain.h>
17 #include <linux/slab.h>
18 #include <linux/sched.h>
19 #include <linux/sched/rt.h>
20 #include <linux/sched/task.h>
21 #include <uapi/linux/sched/types.h>
22 #include <linux/task_work.h>
24 #include "internals.h"
26 #ifdef CONFIG_IRQ_FORCED_THREADING
27 __read_mostly bool force_irqthreads;
28 EXPORT_SYMBOL_GPL(force_irqthreads);
30 static int __init setup_forced_irqthreads(char *arg)
32 force_irqthreads = true;
35 early_param("threadirqs", setup_forced_irqthreads);
38 static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
50 while (irqd_irq_inprogress(&desc->irq_data))
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
62 if (!inprogress && sync_chip) {
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
72 /* Oops, that failed? */
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
89 * Returns: false if a threaded handler is active.
91 * This function may be called - with care - from IRQ context.
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
98 bool synchronize_hardirq(unsigned int irq)
100 struct irq_desc *desc = irq_to_desc(irq);
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
109 EXPORT_SYMBOL(synchronize_hardirq);
112 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
113 * @irq: interrupt number to wait for
115 * This function waits for any pending IRQ handlers for this interrupt
116 * to complete before returning. If you use this function while
117 * holding a resource the IRQ handler may need you will deadlock.
119 * Can only be called from preemptible code as it might sleep when
120 * an interrupt thread is associated to @irq.
122 * It optionally makes sure (when the irq chip supports that method)
123 * that the interrupt is not pending in any CPU and waiting for
126 void synchronize_irq(unsigned int irq)
128 struct irq_desc *desc = irq_to_desc(irq);
131 __synchronize_hardirq(desc, true);
133 * We made sure that no hardirq handler is
134 * running. Now verify that no threaded handlers are
137 wait_event(desc->wait_for_threads,
138 !atomic_read(&desc->threads_active));
141 EXPORT_SYMBOL(synchronize_irq);
144 cpumask_var_t irq_default_affinity;
146 static bool __irq_can_set_affinity(struct irq_desc *desc)
148 if (!desc || !irqd_can_balance(&desc->irq_data) ||
149 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
155 * irq_can_set_affinity - Check if the affinity of a given irq can be set
156 * @irq: Interrupt to check
159 int irq_can_set_affinity(unsigned int irq)
161 return __irq_can_set_affinity(irq_to_desc(irq));
165 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
166 * @irq: Interrupt to check
168 * Like irq_can_set_affinity() above, but additionally checks for the
169 * AFFINITY_MANAGED flag.
171 bool irq_can_set_affinity_usr(unsigned int irq)
173 struct irq_desc *desc = irq_to_desc(irq);
175 return __irq_can_set_affinity(desc) &&
176 !irqd_affinity_is_managed(&desc->irq_data);
180 * irq_set_thread_affinity - Notify irq threads to adjust affinity
181 * @desc: irq descriptor which has affitnity changed
183 * We just set IRQTF_AFFINITY and delegate the affinity setting
184 * to the interrupt thread itself. We can not call
185 * set_cpus_allowed_ptr() here as we hold desc->lock and this
186 * code can be called from hard interrupt context.
188 void irq_set_thread_affinity(struct irq_desc *desc)
190 struct irqaction *action;
192 for_each_action_of_desc(desc, action)
194 set_bit(IRQTF_AFFINITY, &action->thread_flags);
197 static void irq_validate_effective_affinity(struct irq_data *data)
199 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
200 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
201 struct irq_chip *chip = irq_data_get_irq_chip(data);
203 if (!cpumask_empty(m))
205 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
206 chip->name, data->irq);
210 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
213 struct irq_desc *desc = irq_data_to_desc(data);
214 struct irq_chip *chip = irq_data_get_irq_chip(data);
217 if (!chip || !chip->irq_set_affinity)
220 ret = chip->irq_set_affinity(data, mask, force);
222 case IRQ_SET_MASK_OK:
223 case IRQ_SET_MASK_OK_DONE:
224 cpumask_copy(desc->irq_common_data.affinity, mask);
226 case IRQ_SET_MASK_OK_NOCOPY:
227 irq_validate_effective_affinity(data);
228 irq_set_thread_affinity(desc);
235 #ifdef CONFIG_GENERIC_PENDING_IRQ
236 static inline int irq_set_affinity_pending(struct irq_data *data,
237 const struct cpumask *dest)
239 struct irq_desc *desc = irq_data_to_desc(data);
241 irqd_set_move_pending(data);
242 irq_copy_pending(desc, dest);
246 static inline int irq_set_affinity_pending(struct irq_data *data,
247 const struct cpumask *dest)
253 static int irq_try_set_affinity(struct irq_data *data,
254 const struct cpumask *dest, bool force)
256 int ret = irq_do_set_affinity(data, dest, force);
259 * In case that the underlying vector management is busy and the
260 * architecture supports the generic pending mechanism then utilize
261 * this to avoid returning an error to user space.
263 if (ret == -EBUSY && !force)
264 ret = irq_set_affinity_pending(data, dest);
268 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
271 struct irq_chip *chip = irq_data_get_irq_chip(data);
272 struct irq_desc *desc = irq_data_to_desc(data);
275 if (!chip || !chip->irq_set_affinity)
278 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
279 ret = irq_try_set_affinity(data, mask, force);
281 irqd_set_move_pending(data);
282 irq_copy_pending(desc, mask);
285 if (desc->affinity_notify) {
286 kref_get(&desc->affinity_notify->kref);
287 schedule_work(&desc->affinity_notify->work);
289 irqd_set(data, IRQD_AFFINITY_SET);
294 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
296 struct irq_desc *desc = irq_to_desc(irq);
303 raw_spin_lock_irqsave(&desc->lock, flags);
304 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
305 raw_spin_unlock_irqrestore(&desc->lock, flags);
309 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
312 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
316 desc->affinity_hint = m;
317 irq_put_desc_unlock(desc, flags);
318 /* set the initial affinity to prevent every interrupt being on CPU0 */
320 __irq_set_affinity(irq, m, false);
323 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
325 static void irq_affinity_notify(struct work_struct *work)
327 struct irq_affinity_notify *notify =
328 container_of(work, struct irq_affinity_notify, work);
329 struct irq_desc *desc = irq_to_desc(notify->irq);
330 cpumask_var_t cpumask;
333 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
336 raw_spin_lock_irqsave(&desc->lock, flags);
337 if (irq_move_pending(&desc->irq_data))
338 irq_get_pending(cpumask, desc);
340 cpumask_copy(cpumask, desc->irq_common_data.affinity);
341 raw_spin_unlock_irqrestore(&desc->lock, flags);
343 notify->notify(notify, cpumask);
345 free_cpumask_var(cpumask);
347 kref_put(¬ify->kref, notify->release);
351 * irq_set_affinity_notifier - control notification of IRQ affinity changes
352 * @irq: Interrupt for which to enable/disable notification
353 * @notify: Context for notification, or %NULL to disable
354 * notification. Function pointers must be initialised;
355 * the other fields will be initialised by this function.
357 * Must be called in process context. Notification may only be enabled
358 * after the IRQ is allocated and must be disabled before the IRQ is
359 * freed using free_irq().
362 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
364 struct irq_desc *desc = irq_to_desc(irq);
365 struct irq_affinity_notify *old_notify;
368 /* The release function is promised process context */
371 if (!desc || desc->istate & IRQS_NMI)
374 /* Complete initialisation of *notify */
377 kref_init(¬ify->kref);
378 INIT_WORK(¬ify->work, irq_affinity_notify);
381 raw_spin_lock_irqsave(&desc->lock, flags);
382 old_notify = desc->affinity_notify;
383 desc->affinity_notify = notify;
384 raw_spin_unlock_irqrestore(&desc->lock, flags);
387 cancel_work_sync(&old_notify->work);
388 kref_put(&old_notify->kref, old_notify->release);
393 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
395 #ifndef CONFIG_AUTO_IRQ_AFFINITY
397 * Generic version of the affinity autoselector.
399 int irq_setup_affinity(struct irq_desc *desc)
401 struct cpumask *set = irq_default_affinity;
402 int ret, node = irq_desc_get_node(desc);
403 static DEFINE_RAW_SPINLOCK(mask_lock);
404 static struct cpumask mask;
406 /* Excludes PER_CPU and NO_BALANCE interrupts */
407 if (!__irq_can_set_affinity(desc))
410 raw_spin_lock(&mask_lock);
412 * Preserve the managed affinity setting and a userspace affinity
413 * setup, but make sure that one of the targets is online.
415 if (irqd_affinity_is_managed(&desc->irq_data) ||
416 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
417 if (cpumask_intersects(desc->irq_common_data.affinity,
419 set = desc->irq_common_data.affinity;
421 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
424 cpumask_and(&mask, cpu_online_mask, set);
425 if (cpumask_empty(&mask))
426 cpumask_copy(&mask, cpu_online_mask);
428 if (node != NUMA_NO_NODE) {
429 const struct cpumask *nodemask = cpumask_of_node(node);
431 /* make sure at least one of the cpus in nodemask is online */
432 if (cpumask_intersects(&mask, nodemask))
433 cpumask_and(&mask, &mask, nodemask);
435 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
436 raw_spin_unlock(&mask_lock);
440 /* Wrapper for ALPHA specific affinity selector magic */
441 int irq_setup_affinity(struct irq_desc *desc)
443 return irq_select_affinity(irq_desc_get_irq(desc));
448 * Called when a bogus affinity is set via /proc/irq
450 int irq_select_affinity_usr(unsigned int irq)
452 struct irq_desc *desc = irq_to_desc(irq);
456 raw_spin_lock_irqsave(&desc->lock, flags);
457 ret = irq_setup_affinity(desc);
458 raw_spin_unlock_irqrestore(&desc->lock, flags);
464 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
465 * @irq: interrupt number to set affinity
466 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
467 * specific data for percpu_devid interrupts
469 * This function uses the vCPU specific data to set the vCPU
470 * affinity for an irq. The vCPU specific data is passed from
471 * outside, such as KVM. One example code path is as below:
472 * KVM -> IOMMU -> irq_set_vcpu_affinity().
474 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
477 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
478 struct irq_data *data;
479 struct irq_chip *chip;
485 data = irq_desc_get_irq_data(desc);
487 chip = irq_data_get_irq_chip(data);
488 if (chip && chip->irq_set_vcpu_affinity)
490 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
491 data = data->parent_data;
498 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
499 irq_put_desc_unlock(desc, flags);
503 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
505 void __disable_irq(struct irq_desc *desc)
511 static int __disable_irq_nosync(unsigned int irq)
514 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
519 irq_put_desc_busunlock(desc, flags);
524 * disable_irq_nosync - disable an irq without waiting
525 * @irq: Interrupt to disable
527 * Disable the selected interrupt line. Disables and Enables are
529 * Unlike disable_irq(), this function does not ensure existing
530 * instances of the IRQ handler have completed before returning.
532 * This function may be called from IRQ context.
534 void disable_irq_nosync(unsigned int irq)
536 __disable_irq_nosync(irq);
538 EXPORT_SYMBOL(disable_irq_nosync);
541 * disable_irq - disable an irq and wait for completion
542 * @irq: Interrupt to disable
544 * Disable the selected interrupt line. Enables and Disables are
546 * This function waits for any pending IRQ handlers for this interrupt
547 * to complete before returning. If you use this function while
548 * holding a resource the IRQ handler may need you will deadlock.
550 * This function may be called - with care - from IRQ context.
552 void disable_irq(unsigned int irq)
554 if (!__disable_irq_nosync(irq))
555 synchronize_irq(irq);
557 EXPORT_SYMBOL(disable_irq);
560 * disable_hardirq - disables an irq and waits for hardirq completion
561 * @irq: Interrupt to disable
563 * Disable the selected interrupt line. Enables and Disables are
565 * This function waits for any pending hard IRQ handlers for this
566 * interrupt to complete before returning. If you use this function while
567 * holding a resource the hard IRQ handler may need you will deadlock.
569 * When used to optimistically disable an interrupt from atomic context
570 * the return value must be checked.
572 * Returns: false if a threaded handler is active.
574 * This function may be called - with care - from IRQ context.
576 bool disable_hardirq(unsigned int irq)
578 if (!__disable_irq_nosync(irq))
579 return synchronize_hardirq(irq);
583 EXPORT_SYMBOL_GPL(disable_hardirq);
586 * disable_nmi_nosync - disable an nmi without waiting
587 * @irq: Interrupt to disable
589 * Disable the selected interrupt line. Disables and enables are
591 * The interrupt to disable must have been requested through request_nmi.
592 * Unlike disable_nmi(), this function does not ensure existing
593 * instances of the IRQ handler have completed before returning.
595 void disable_nmi_nosync(unsigned int irq)
597 disable_irq_nosync(irq);
600 void __enable_irq(struct irq_desc *desc)
602 switch (desc->depth) {
605 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
606 irq_desc_get_irq(desc));
609 if (desc->istate & IRQS_SUSPENDED)
611 /* Prevent probing on this irq: */
612 irq_settings_set_noprobe(desc);
614 * Call irq_startup() not irq_enable() here because the
615 * interrupt might be marked NOAUTOEN. So irq_startup()
616 * needs to be invoked when it gets enabled the first
617 * time. If it was already started up, then irq_startup()
618 * will invoke irq_enable() under the hood.
620 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
629 * enable_irq - enable handling of an irq
630 * @irq: Interrupt to enable
632 * Undoes the effect of one call to disable_irq(). If this
633 * matches the last disable, processing of interrupts on this
634 * IRQ line is re-enabled.
636 * This function may be called from IRQ context only when
637 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
639 void enable_irq(unsigned int irq)
642 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
646 if (WARN(!desc->irq_data.chip,
647 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
652 irq_put_desc_busunlock(desc, flags);
654 EXPORT_SYMBOL(enable_irq);
657 * enable_nmi - enable handling of an nmi
658 * @irq: Interrupt to enable
660 * The interrupt to enable must have been requested through request_nmi.
661 * Undoes the effect of one call to disable_nmi(). If this
662 * matches the last disable, processing of interrupts on this
663 * IRQ line is re-enabled.
665 void enable_nmi(unsigned int irq)
670 static int set_irq_wake_real(unsigned int irq, unsigned int on)
672 struct irq_desc *desc = irq_to_desc(irq);
675 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
678 if (desc->irq_data.chip->irq_set_wake)
679 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
685 * irq_set_irq_wake - control irq power management wakeup
686 * @irq: interrupt to control
687 * @on: enable/disable power management wakeup
689 * Enable/disable power management wakeup mode, which is
690 * disabled by default. Enables and disables must match,
691 * just as they match for non-wakeup mode support.
693 * Wakeup mode lets this IRQ wake the system from sleep
694 * states like "suspend to RAM".
696 int irq_set_irq_wake(unsigned int irq, unsigned int on)
699 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
705 /* Don't use NMIs as wake up interrupts please */
706 if (desc->istate & IRQS_NMI) {
711 /* wakeup-capable irqs can be shared between drivers that
712 * don't need to have the same sleep mode behaviors.
715 if (desc->wake_depth++ == 0) {
716 ret = set_irq_wake_real(irq, on);
718 desc->wake_depth = 0;
720 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
723 if (desc->wake_depth == 0) {
724 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
725 } else if (--desc->wake_depth == 0) {
726 ret = set_irq_wake_real(irq, on);
728 desc->wake_depth = 1;
730 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
735 irq_put_desc_busunlock(desc, flags);
738 EXPORT_SYMBOL(irq_set_irq_wake);
741 * Internal function that tells the architecture code whether a
742 * particular irq has been exclusively allocated or is available
745 int can_request_irq(unsigned int irq, unsigned long irqflags)
748 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
754 if (irq_settings_can_request(desc)) {
756 irqflags & desc->action->flags & IRQF_SHARED)
759 irq_put_desc_unlock(desc, flags);
763 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
765 struct irq_chip *chip = desc->irq_data.chip;
768 if (!chip || !chip->irq_set_type) {
770 * IRQF_TRIGGER_* but the PIC does not support multiple
773 pr_debug("No set_type function for IRQ %d (%s)\n",
774 irq_desc_get_irq(desc),
775 chip ? (chip->name ? : "unknown") : "unknown");
779 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
780 if (!irqd_irq_masked(&desc->irq_data))
782 if (!irqd_irq_disabled(&desc->irq_data))
786 /* Mask all flags except trigger mode */
787 flags &= IRQ_TYPE_SENSE_MASK;
788 ret = chip->irq_set_type(&desc->irq_data, flags);
791 case IRQ_SET_MASK_OK:
792 case IRQ_SET_MASK_OK_DONE:
793 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
794 irqd_set(&desc->irq_data, flags);
797 case IRQ_SET_MASK_OK_NOCOPY:
798 flags = irqd_get_trigger_type(&desc->irq_data);
799 irq_settings_set_trigger_mask(desc, flags);
800 irqd_clear(&desc->irq_data, IRQD_LEVEL);
801 irq_settings_clr_level(desc);
802 if (flags & IRQ_TYPE_LEVEL_MASK) {
803 irq_settings_set_level(desc);
804 irqd_set(&desc->irq_data, IRQD_LEVEL);
810 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
811 flags, irq_desc_get_irq(desc), chip->irq_set_type);
818 #ifdef CONFIG_HARDIRQS_SW_RESEND
819 int irq_set_parent(int irq, int parent_irq)
822 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
827 desc->parent_irq = parent_irq;
829 irq_put_desc_unlock(desc, flags);
832 EXPORT_SYMBOL_GPL(irq_set_parent);
836 * Default primary interrupt handler for threaded interrupts. Is
837 * assigned as primary handler when request_threaded_irq is called
838 * with handler == NULL. Useful for oneshot interrupts.
840 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
842 return IRQ_WAKE_THREAD;
846 * Primary handler for nested threaded interrupts. Should never be
849 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
851 WARN(1, "Primary handler called for nested irq %d\n", irq);
855 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
857 WARN(1, "Secondary action handler called for irq %d\n", irq);
861 static int irq_wait_for_interrupt(struct irqaction *action)
864 set_current_state(TASK_INTERRUPTIBLE);
866 if (kthread_should_stop()) {
867 /* may need to run one last time */
868 if (test_and_clear_bit(IRQTF_RUNTHREAD,
869 &action->thread_flags)) {
870 __set_current_state(TASK_RUNNING);
873 __set_current_state(TASK_RUNNING);
877 if (test_and_clear_bit(IRQTF_RUNTHREAD,
878 &action->thread_flags)) {
879 __set_current_state(TASK_RUNNING);
887 * Oneshot interrupts keep the irq line masked until the threaded
888 * handler finished. unmask if the interrupt has not been disabled and
891 static void irq_finalize_oneshot(struct irq_desc *desc,
892 struct irqaction *action)
894 if (!(desc->istate & IRQS_ONESHOT) ||
895 action->handler == irq_forced_secondary_handler)
899 raw_spin_lock_irq(&desc->lock);
902 * Implausible though it may be we need to protect us against
903 * the following scenario:
905 * The thread is faster done than the hard interrupt handler
906 * on the other CPU. If we unmask the irq line then the
907 * interrupt can come in again and masks the line, leaves due
908 * to IRQS_INPROGRESS and the irq line is masked forever.
910 * This also serializes the state of shared oneshot handlers
911 * versus "desc->threads_onehsot |= action->thread_mask;" in
912 * irq_wake_thread(). See the comment there which explains the
915 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
916 raw_spin_unlock_irq(&desc->lock);
917 chip_bus_sync_unlock(desc);
923 * Now check again, whether the thread should run. Otherwise
924 * we would clear the threads_oneshot bit of this thread which
927 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
930 desc->threads_oneshot &= ~action->thread_mask;
932 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
933 irqd_irq_masked(&desc->irq_data))
934 unmask_threaded_irq(desc);
937 raw_spin_unlock_irq(&desc->lock);
938 chip_bus_sync_unlock(desc);
943 * Check whether we need to change the affinity of the interrupt thread.
946 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
951 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
955 * In case we are out of memory we set IRQTF_AFFINITY again and
956 * try again next time
958 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
959 set_bit(IRQTF_AFFINITY, &action->thread_flags);
963 raw_spin_lock_irq(&desc->lock);
965 * This code is triggered unconditionally. Check the affinity
966 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
968 if (cpumask_available(desc->irq_common_data.affinity)) {
969 const struct cpumask *m;
971 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
972 cpumask_copy(mask, m);
976 raw_spin_unlock_irq(&desc->lock);
979 set_cpus_allowed_ptr(current, mask);
980 free_cpumask_var(mask);
984 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
988 * Interrupts which are not explicitly requested as threaded
989 * interrupts rely on the implicit bh/preempt disable of the hard irq
990 * context. So we need to disable bh here to avoid deadlocks and other
994 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
999 ret = action->thread_fn(action->irq, action->dev_id);
1000 if (ret == IRQ_HANDLED)
1001 atomic_inc(&desc->threads_handled);
1003 irq_finalize_oneshot(desc, action);
1009 * Interrupts explicitly requested as threaded interrupts want to be
1010 * preemtible - many of them need to sleep and wait for slow busses to
1013 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1014 struct irqaction *action)
1018 ret = action->thread_fn(action->irq, action->dev_id);
1019 if (ret == IRQ_HANDLED)
1020 atomic_inc(&desc->threads_handled);
1022 irq_finalize_oneshot(desc, action);
1026 static void wake_threads_waitq(struct irq_desc *desc)
1028 if (atomic_dec_and_test(&desc->threads_active))
1029 wake_up(&desc->wait_for_threads);
1032 static void irq_thread_dtor(struct callback_head *unused)
1034 struct task_struct *tsk = current;
1035 struct irq_desc *desc;
1036 struct irqaction *action;
1038 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1041 action = kthread_data(tsk);
1043 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1044 tsk->comm, tsk->pid, action->irq);
1047 desc = irq_to_desc(action->irq);
1049 * If IRQTF_RUNTHREAD is set, we need to decrement
1050 * desc->threads_active and wake possible waiters.
1052 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1053 wake_threads_waitq(desc);
1055 /* Prevent a stale desc->threads_oneshot */
1056 irq_finalize_oneshot(desc, action);
1059 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1061 struct irqaction *secondary = action->secondary;
1063 if (WARN_ON_ONCE(!secondary))
1066 raw_spin_lock_irq(&desc->lock);
1067 __irq_wake_thread(desc, secondary);
1068 raw_spin_unlock_irq(&desc->lock);
1072 * Interrupt handler thread
1074 static int irq_thread(void *data)
1076 struct callback_head on_exit_work;
1077 struct irqaction *action = data;
1078 struct irq_desc *desc = irq_to_desc(action->irq);
1079 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1080 struct irqaction *action);
1082 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1083 &action->thread_flags))
1084 handler_fn = irq_forced_thread_fn;
1086 handler_fn = irq_thread_fn;
1088 init_task_work(&on_exit_work, irq_thread_dtor);
1089 task_work_add(current, &on_exit_work, false);
1091 irq_thread_check_affinity(desc, action);
1093 while (!irq_wait_for_interrupt(action)) {
1094 irqreturn_t action_ret;
1096 irq_thread_check_affinity(desc, action);
1098 action_ret = handler_fn(desc, action);
1099 if (action_ret == IRQ_WAKE_THREAD)
1100 irq_wake_secondary(desc, action);
1102 wake_threads_waitq(desc);
1106 * This is the regular exit path. __free_irq() is stopping the
1107 * thread via kthread_stop() after calling
1108 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1109 * oneshot mask bit can be set.
1111 task_work_cancel(current, irq_thread_dtor);
1116 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1117 * @irq: Interrupt line
1118 * @dev_id: Device identity for which the thread should be woken
1121 void irq_wake_thread(unsigned int irq, void *dev_id)
1123 struct irq_desc *desc = irq_to_desc(irq);
1124 struct irqaction *action;
1125 unsigned long flags;
1127 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1130 raw_spin_lock_irqsave(&desc->lock, flags);
1131 for_each_action_of_desc(desc, action) {
1132 if (action->dev_id == dev_id) {
1134 __irq_wake_thread(desc, action);
1138 raw_spin_unlock_irqrestore(&desc->lock, flags);
1140 EXPORT_SYMBOL_GPL(irq_wake_thread);
1142 static int irq_setup_forced_threading(struct irqaction *new)
1144 if (!force_irqthreads)
1146 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1150 * No further action required for interrupts which are requested as
1151 * threaded interrupts already
1153 if (new->handler == irq_default_primary_handler)
1156 new->flags |= IRQF_ONESHOT;
1159 * Handle the case where we have a real primary handler and a
1160 * thread handler. We force thread them as well by creating a
1163 if (new->handler && new->thread_fn) {
1164 /* Allocate the secondary action */
1165 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1166 if (!new->secondary)
1168 new->secondary->handler = irq_forced_secondary_handler;
1169 new->secondary->thread_fn = new->thread_fn;
1170 new->secondary->dev_id = new->dev_id;
1171 new->secondary->irq = new->irq;
1172 new->secondary->name = new->name;
1174 /* Deal with the primary handler */
1175 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1176 new->thread_fn = new->handler;
1177 new->handler = irq_default_primary_handler;
1181 static int irq_request_resources(struct irq_desc *desc)
1183 struct irq_data *d = &desc->irq_data;
1184 struct irq_chip *c = d->chip;
1186 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1189 static void irq_release_resources(struct irq_desc *desc)
1191 struct irq_data *d = &desc->irq_data;
1192 struct irq_chip *c = d->chip;
1194 if (c->irq_release_resources)
1195 c->irq_release_resources(d);
1198 static bool irq_supports_nmi(struct irq_desc *desc)
1200 struct irq_data *d = irq_desc_get_irq_data(desc);
1202 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1203 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1207 /* Don't support NMIs for chips behind a slow bus */
1208 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1211 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1214 static int irq_nmi_setup(struct irq_desc *desc)
1216 struct irq_data *d = irq_desc_get_irq_data(desc);
1217 struct irq_chip *c = d->chip;
1219 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1222 static void irq_nmi_teardown(struct irq_desc *desc)
1224 struct irq_data *d = irq_desc_get_irq_data(desc);
1225 struct irq_chip *c = d->chip;
1227 if (c->irq_nmi_teardown)
1228 c->irq_nmi_teardown(d);
1232 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1234 struct task_struct *t;
1235 struct sched_param param = {
1236 .sched_priority = MAX_USER_RT_PRIO/2,
1240 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1243 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1245 param.sched_priority -= 1;
1251 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1254 * We keep the reference to the task struct even if
1255 * the thread dies to avoid that the interrupt code
1256 * references an already freed task_struct.
1261 * Tell the thread to set its affinity. This is
1262 * important for shared interrupt handlers as we do
1263 * not invoke setup_affinity() for the secondary
1264 * handlers as everything is already set up. Even for
1265 * interrupts marked with IRQF_NO_BALANCE this is
1266 * correct as we want the thread to move to the cpu(s)
1267 * on which the requesting code placed the interrupt.
1269 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1274 * Internal function to register an irqaction - typically used to
1275 * allocate special interrupts that are part of the architecture.
1279 * desc->request_mutex Provides serialization against a concurrent free_irq()
1280 * chip_bus_lock Provides serialization for slow bus operations
1281 * desc->lock Provides serialization against hard interrupts
1283 * chip_bus_lock and desc->lock are sufficient for all other management and
1284 * interrupt related functions. desc->request_mutex solely serializes
1285 * request/free_irq().
1288 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1290 struct irqaction *old, **old_ptr;
1291 unsigned long flags, thread_mask = 0;
1292 int ret, nested, shared = 0;
1297 if (desc->irq_data.chip == &no_irq_chip)
1299 if (!try_module_get(desc->owner))
1305 * If the trigger type is not specified by the caller,
1306 * then use the default for this interrupt.
1308 if (!(new->flags & IRQF_TRIGGER_MASK))
1309 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1312 * Check whether the interrupt nests into another interrupt
1315 nested = irq_settings_is_nested_thread(desc);
1317 if (!new->thread_fn) {
1322 * Replace the primary handler which was provided from
1323 * the driver for non nested interrupt handling by the
1324 * dummy function which warns when called.
1326 new->handler = irq_nested_primary_handler;
1328 if (irq_settings_can_thread(desc)) {
1329 ret = irq_setup_forced_threading(new);
1336 * Create a handler thread when a thread function is supplied
1337 * and the interrupt does not nest into another interrupt
1340 if (new->thread_fn && !nested) {
1341 ret = setup_irq_thread(new, irq, false);
1344 if (new->secondary) {
1345 ret = setup_irq_thread(new->secondary, irq, true);
1352 * Drivers are often written to work w/o knowledge about the
1353 * underlying irq chip implementation, so a request for a
1354 * threaded irq without a primary hard irq context handler
1355 * requires the ONESHOT flag to be set. Some irq chips like
1356 * MSI based interrupts are per se one shot safe. Check the
1357 * chip flags, so we can avoid the unmask dance at the end of
1358 * the threaded handler for those.
1360 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1361 new->flags &= ~IRQF_ONESHOT;
1364 * Protects against a concurrent __free_irq() call which might wait
1365 * for synchronize_hardirq() to complete without holding the optional
1366 * chip bus lock and desc->lock. Also protects against handing out
1367 * a recycled oneshot thread_mask bit while it's still in use by
1368 * its previous owner.
1370 mutex_lock(&desc->request_mutex);
1373 * Acquire bus lock as the irq_request_resources() callback below
1374 * might rely on the serialization or the magic power management
1375 * functions which are abusing the irq_bus_lock() callback,
1377 chip_bus_lock(desc);
1379 /* First installed action requests resources. */
1380 if (!desc->action) {
1381 ret = irq_request_resources(desc);
1383 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1384 new->name, irq, desc->irq_data.chip->name);
1385 goto out_bus_unlock;
1390 * The following block of code has to be executed atomically
1391 * protected against a concurrent interrupt and any of the other
1392 * management calls which are not serialized via
1393 * desc->request_mutex or the optional bus lock.
1395 raw_spin_lock_irqsave(&desc->lock, flags);
1396 old_ptr = &desc->action;
1400 * Can't share interrupts unless both agree to and are
1401 * the same type (level, edge, polarity). So both flag
1402 * fields must have IRQF_SHARED set and the bits which
1403 * set the trigger type must match. Also all must
1405 * Interrupt lines used for NMIs cannot be shared.
1407 unsigned int oldtype;
1409 if (desc->istate & IRQS_NMI) {
1410 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1411 new->name, irq, desc->irq_data.chip->name);
1417 * If nobody did set the configuration before, inherit
1418 * the one provided by the requester.
1420 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1421 oldtype = irqd_get_trigger_type(&desc->irq_data);
1423 oldtype = new->flags & IRQF_TRIGGER_MASK;
1424 irqd_set_trigger_type(&desc->irq_data, oldtype);
1427 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1428 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1429 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1432 /* All handlers must agree on per-cpuness */
1433 if ((old->flags & IRQF_PERCPU) !=
1434 (new->flags & IRQF_PERCPU))
1437 /* add new interrupt at end of irq queue */
1440 * Or all existing action->thread_mask bits,
1441 * so we can find the next zero bit for this
1444 thread_mask |= old->thread_mask;
1445 old_ptr = &old->next;
1452 * Setup the thread mask for this irqaction for ONESHOT. For
1453 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1454 * conditional in irq_wake_thread().
1456 if (new->flags & IRQF_ONESHOT) {
1458 * Unlikely to have 32 resp 64 irqs sharing one line,
1461 if (thread_mask == ~0UL) {
1466 * The thread_mask for the action is or'ed to
1467 * desc->thread_active to indicate that the
1468 * IRQF_ONESHOT thread handler has been woken, but not
1469 * yet finished. The bit is cleared when a thread
1470 * completes. When all threads of a shared interrupt
1471 * line have completed desc->threads_active becomes
1472 * zero and the interrupt line is unmasked. See
1473 * handle.c:irq_wake_thread() for further information.
1475 * If no thread is woken by primary (hard irq context)
1476 * interrupt handlers, then desc->threads_active is
1477 * also checked for zero to unmask the irq line in the
1478 * affected hard irq flow handlers
1479 * (handle_[fasteoi|level]_irq).
1481 * The new action gets the first zero bit of
1482 * thread_mask assigned. See the loop above which or's
1483 * all existing action->thread_mask bits.
1485 new->thread_mask = 1UL << ffz(thread_mask);
1487 } else if (new->handler == irq_default_primary_handler &&
1488 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1490 * The interrupt was requested with handler = NULL, so
1491 * we use the default primary handler for it. But it
1492 * does not have the oneshot flag set. In combination
1493 * with level interrupts this is deadly, because the
1494 * default primary handler just wakes the thread, then
1495 * the irq lines is reenabled, but the device still
1496 * has the level irq asserted. Rinse and repeat....
1498 * While this works for edge type interrupts, we play
1499 * it safe and reject unconditionally because we can't
1500 * say for sure which type this interrupt really
1501 * has. The type flags are unreliable as the
1502 * underlying chip implementation can override them.
1504 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1511 init_waitqueue_head(&desc->wait_for_threads);
1513 /* Setup the type (level, edge polarity) if configured: */
1514 if (new->flags & IRQF_TRIGGER_MASK) {
1515 ret = __irq_set_trigger(desc,
1516 new->flags & IRQF_TRIGGER_MASK);
1523 * Activate the interrupt. That activation must happen
1524 * independently of IRQ_NOAUTOEN. request_irq() can fail
1525 * and the callers are supposed to handle
1526 * that. enable_irq() of an interrupt requested with
1527 * IRQ_NOAUTOEN is not supposed to fail. The activation
1528 * keeps it in shutdown mode, it merily associates
1529 * resources if necessary and if that's not possible it
1530 * fails. Interrupts which are in managed shutdown mode
1531 * will simply ignore that activation request.
1533 ret = irq_activate(desc);
1537 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1538 IRQS_ONESHOT | IRQS_WAITING);
1539 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1541 if (new->flags & IRQF_PERCPU) {
1542 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1543 irq_settings_set_per_cpu(desc);
1546 if (new->flags & IRQF_ONESHOT)
1547 desc->istate |= IRQS_ONESHOT;
1549 /* Exclude IRQ from balancing if requested */
1550 if (new->flags & IRQF_NOBALANCING) {
1551 irq_settings_set_no_balancing(desc);
1552 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1555 if (irq_settings_can_autoenable(desc)) {
1556 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1559 * Shared interrupts do not go well with disabling
1560 * auto enable. The sharing interrupt might request
1561 * it while it's still disabled and then wait for
1562 * interrupts forever.
1564 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1565 /* Undo nested disables: */
1569 } else if (new->flags & IRQF_TRIGGER_MASK) {
1570 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1571 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1574 /* hope the handler works with current trigger mode */
1575 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1581 irq_pm_install_action(desc, new);
1583 /* Reset broken irq detection when installing new handler */
1584 desc->irq_count = 0;
1585 desc->irqs_unhandled = 0;
1588 * Check whether we disabled the irq via the spurious handler
1589 * before. Reenable it and give it another chance.
1591 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1592 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1596 raw_spin_unlock_irqrestore(&desc->lock, flags);
1597 chip_bus_sync_unlock(desc);
1598 mutex_unlock(&desc->request_mutex);
1600 irq_setup_timings(desc, new);
1603 * Strictly no need to wake it up, but hung_task complains
1604 * when no hard interrupt wakes the thread up.
1607 wake_up_process(new->thread);
1609 wake_up_process(new->secondary->thread);
1611 register_irq_proc(irq, desc);
1613 register_handler_proc(irq, new);
1617 if (!(new->flags & IRQF_PROBE_SHARED)) {
1618 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1619 irq, new->flags, new->name, old->flags, old->name);
1620 #ifdef CONFIG_DEBUG_SHIRQ
1627 raw_spin_unlock_irqrestore(&desc->lock, flags);
1630 irq_release_resources(desc);
1632 chip_bus_sync_unlock(desc);
1633 mutex_unlock(&desc->request_mutex);
1637 struct task_struct *t = new->thread;
1643 if (new->secondary && new->secondary->thread) {
1644 struct task_struct *t = new->secondary->thread;
1646 new->secondary->thread = NULL;
1651 module_put(desc->owner);
1656 * setup_irq - setup an interrupt
1657 * @irq: Interrupt line to setup
1658 * @act: irqaction for the interrupt
1660 * Used to statically setup interrupts in the early boot process.
1662 int setup_irq(unsigned int irq, struct irqaction *act)
1665 struct irq_desc *desc = irq_to_desc(irq);
1667 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1670 retval = irq_chip_pm_get(&desc->irq_data);
1674 retval = __setup_irq(irq, desc, act);
1677 irq_chip_pm_put(&desc->irq_data);
1681 EXPORT_SYMBOL_GPL(setup_irq);
1684 * Internal function to unregister an irqaction - used to free
1685 * regular and special interrupts that are part of the architecture.
1687 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1689 unsigned irq = desc->irq_data.irq;
1690 struct irqaction *action, **action_ptr;
1691 unsigned long flags;
1693 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1695 mutex_lock(&desc->request_mutex);
1696 chip_bus_lock(desc);
1697 raw_spin_lock_irqsave(&desc->lock, flags);
1700 * There can be multiple actions per IRQ descriptor, find the right
1701 * one based on the dev_id:
1703 action_ptr = &desc->action;
1705 action = *action_ptr;
1708 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1709 raw_spin_unlock_irqrestore(&desc->lock, flags);
1710 chip_bus_sync_unlock(desc);
1711 mutex_unlock(&desc->request_mutex);
1715 if (action->dev_id == dev_id)
1717 action_ptr = &action->next;
1720 /* Found it - now remove it from the list of entries: */
1721 *action_ptr = action->next;
1723 irq_pm_remove_action(desc, action);
1725 /* If this was the last handler, shut down the IRQ line: */
1726 if (!desc->action) {
1727 irq_settings_clr_disable_unlazy(desc);
1728 /* Only shutdown. Deactivate after synchronize_hardirq() */
1733 /* make sure affinity_hint is cleaned up */
1734 if (WARN_ON_ONCE(desc->affinity_hint))
1735 desc->affinity_hint = NULL;
1738 raw_spin_unlock_irqrestore(&desc->lock, flags);
1740 * Drop bus_lock here so the changes which were done in the chip
1741 * callbacks above are synced out to the irq chips which hang
1742 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1744 * Aside of that the bus_lock can also be taken from the threaded
1745 * handler in irq_finalize_oneshot() which results in a deadlock
1746 * because kthread_stop() would wait forever for the thread to
1747 * complete, which is blocked on the bus lock.
1749 * The still held desc->request_mutex() protects against a
1750 * concurrent request_irq() of this irq so the release of resources
1751 * and timing data is properly serialized.
1753 chip_bus_sync_unlock(desc);
1755 unregister_handler_proc(irq, action);
1758 * Make sure it's not being used on another CPU and if the chip
1759 * supports it also make sure that there is no (not yet serviced)
1760 * interrupt in flight at the hardware level.
1762 __synchronize_hardirq(desc, true);
1764 #ifdef CONFIG_DEBUG_SHIRQ
1766 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1767 * event to happen even now it's being freed, so let's make sure that
1768 * is so by doing an extra call to the handler ....
1770 * ( We do this after actually deregistering it, to make sure that a
1771 * 'real' IRQ doesn't run in parallel with our fake. )
1773 if (action->flags & IRQF_SHARED) {
1774 local_irq_save(flags);
1775 action->handler(irq, dev_id);
1776 local_irq_restore(flags);
1781 * The action has already been removed above, but the thread writes
1782 * its oneshot mask bit when it completes. Though request_mutex is
1783 * held across this which prevents __setup_irq() from handing out
1784 * the same bit to a newly requested action.
1786 if (action->thread) {
1787 kthread_stop(action->thread);
1788 put_task_struct(action->thread);
1789 if (action->secondary && action->secondary->thread) {
1790 kthread_stop(action->secondary->thread);
1791 put_task_struct(action->secondary->thread);
1795 /* Last action releases resources */
1796 if (!desc->action) {
1798 * Reaquire bus lock as irq_release_resources() might
1799 * require it to deallocate resources over the slow bus.
1801 chip_bus_lock(desc);
1803 * There is no interrupt on the fly anymore. Deactivate it
1806 raw_spin_lock_irqsave(&desc->lock, flags);
1807 irq_domain_deactivate_irq(&desc->irq_data);
1808 raw_spin_unlock_irqrestore(&desc->lock, flags);
1810 irq_release_resources(desc);
1811 chip_bus_sync_unlock(desc);
1812 irq_remove_timings(desc);
1815 mutex_unlock(&desc->request_mutex);
1817 irq_chip_pm_put(&desc->irq_data);
1818 module_put(desc->owner);
1819 kfree(action->secondary);
1824 * remove_irq - free an interrupt
1825 * @irq: Interrupt line to free
1826 * @act: irqaction for the interrupt
1828 * Used to remove interrupts statically setup by the early boot process.
1830 void remove_irq(unsigned int irq, struct irqaction *act)
1832 struct irq_desc *desc = irq_to_desc(irq);
1834 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1835 __free_irq(desc, act->dev_id);
1837 EXPORT_SYMBOL_GPL(remove_irq);
1840 * free_irq - free an interrupt allocated with request_irq
1841 * @irq: Interrupt line to free
1842 * @dev_id: Device identity to free
1844 * Remove an interrupt handler. The handler is removed and if the
1845 * interrupt line is no longer in use by any driver it is disabled.
1846 * On a shared IRQ the caller must ensure the interrupt is disabled
1847 * on the card it drives before calling this function. The function
1848 * does not return until any executing interrupts for this IRQ
1851 * This function must not be called from interrupt context.
1853 * Returns the devname argument passed to request_irq.
1855 const void *free_irq(unsigned int irq, void *dev_id)
1857 struct irq_desc *desc = irq_to_desc(irq);
1858 struct irqaction *action;
1859 const char *devname;
1861 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1865 if (WARN_ON(desc->affinity_notify))
1866 desc->affinity_notify = NULL;
1869 action = __free_irq(desc, dev_id);
1874 devname = action->name;
1878 EXPORT_SYMBOL(free_irq);
1880 /* This function must be called with desc->lock held */
1881 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1883 const char *devname = NULL;
1885 desc->istate &= ~IRQS_NMI;
1887 if (!WARN_ON(desc->action == NULL)) {
1888 irq_pm_remove_action(desc, desc->action);
1889 devname = desc->action->name;
1890 unregister_handler_proc(irq, desc->action);
1892 kfree(desc->action);
1893 desc->action = NULL;
1896 irq_settings_clr_disable_unlazy(desc);
1897 irq_shutdown_and_deactivate(desc);
1899 irq_release_resources(desc);
1901 irq_chip_pm_put(&desc->irq_data);
1902 module_put(desc->owner);
1907 const void *free_nmi(unsigned int irq, void *dev_id)
1909 struct irq_desc *desc = irq_to_desc(irq);
1910 unsigned long flags;
1911 const void *devname;
1913 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1916 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1919 /* NMI still enabled */
1920 if (WARN_ON(desc->depth == 0))
1921 disable_nmi_nosync(irq);
1923 raw_spin_lock_irqsave(&desc->lock, flags);
1925 irq_nmi_teardown(desc);
1926 devname = __cleanup_nmi(irq, desc);
1928 raw_spin_unlock_irqrestore(&desc->lock, flags);
1934 * request_threaded_irq - allocate an interrupt line
1935 * @irq: Interrupt line to allocate
1936 * @handler: Function to be called when the IRQ occurs.
1937 * Primary handler for threaded interrupts
1938 * If NULL and thread_fn != NULL the default
1939 * primary handler is installed
1940 * @thread_fn: Function called from the irq handler thread
1941 * If NULL, no irq thread is created
1942 * @irqflags: Interrupt type flags
1943 * @devname: An ascii name for the claiming device
1944 * @dev_id: A cookie passed back to the handler function
1946 * This call allocates interrupt resources and enables the
1947 * interrupt line and IRQ handling. From the point this
1948 * call is made your handler function may be invoked. Since
1949 * your handler function must clear any interrupt the board
1950 * raises, you must take care both to initialise your hardware
1951 * and to set up the interrupt handler in the right order.
1953 * If you want to set up a threaded irq handler for your device
1954 * then you need to supply @handler and @thread_fn. @handler is
1955 * still called in hard interrupt context and has to check
1956 * whether the interrupt originates from the device. If yes it
1957 * needs to disable the interrupt on the device and return
1958 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1959 * @thread_fn. This split handler design is necessary to support
1960 * shared interrupts.
1962 * Dev_id must be globally unique. Normally the address of the
1963 * device data structure is used as the cookie. Since the handler
1964 * receives this value it makes sense to use it.
1966 * If your interrupt is shared you must pass a non NULL dev_id
1967 * as this is required when freeing the interrupt.
1971 * IRQF_SHARED Interrupt is shared
1972 * IRQF_TRIGGER_* Specify active edge(s) or level
1975 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1976 irq_handler_t thread_fn, unsigned long irqflags,
1977 const char *devname, void *dev_id)
1979 struct irqaction *action;
1980 struct irq_desc *desc;
1983 if (irq == IRQ_NOTCONNECTED)
1987 * Sanity-check: shared interrupts must pass in a real dev-ID,
1988 * otherwise we'll have trouble later trying to figure out
1989 * which interrupt is which (messes up the interrupt freeing
1992 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1993 * it cannot be set along with IRQF_NO_SUSPEND.
1995 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1996 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1997 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2000 desc = irq_to_desc(irq);
2004 if (!irq_settings_can_request(desc) ||
2005 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2011 handler = irq_default_primary_handler;
2014 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2018 action->handler = handler;
2019 action->thread_fn = thread_fn;
2020 action->flags = irqflags;
2021 action->name = devname;
2022 action->dev_id = dev_id;
2024 retval = irq_chip_pm_get(&desc->irq_data);
2030 retval = __setup_irq(irq, desc, action);
2033 irq_chip_pm_put(&desc->irq_data);
2034 kfree(action->secondary);
2038 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2039 if (!retval && (irqflags & IRQF_SHARED)) {
2041 * It's a shared IRQ -- the driver ought to be prepared for it
2042 * to happen immediately, so let's make sure....
2043 * We disable the irq to make sure that a 'real' IRQ doesn't
2044 * run in parallel with our fake.
2046 unsigned long flags;
2049 local_irq_save(flags);
2051 handler(irq, dev_id);
2053 local_irq_restore(flags);
2059 EXPORT_SYMBOL(request_threaded_irq);
2062 * request_any_context_irq - allocate an interrupt line
2063 * @irq: Interrupt line to allocate
2064 * @handler: Function to be called when the IRQ occurs.
2065 * Threaded handler for threaded interrupts.
2066 * @flags: Interrupt type flags
2067 * @name: An ascii name for the claiming device
2068 * @dev_id: A cookie passed back to the handler function
2070 * This call allocates interrupt resources and enables the
2071 * interrupt line and IRQ handling. It selects either a
2072 * hardirq or threaded handling method depending on the
2075 * On failure, it returns a negative value. On success,
2076 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2078 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2079 unsigned long flags, const char *name, void *dev_id)
2081 struct irq_desc *desc;
2084 if (irq == IRQ_NOTCONNECTED)
2087 desc = irq_to_desc(irq);
2091 if (irq_settings_is_nested_thread(desc)) {
2092 ret = request_threaded_irq(irq, NULL, handler,
2093 flags, name, dev_id);
2094 return !ret ? IRQC_IS_NESTED : ret;
2097 ret = request_irq(irq, handler, flags, name, dev_id);
2098 return !ret ? IRQC_IS_HARDIRQ : ret;
2100 EXPORT_SYMBOL_GPL(request_any_context_irq);
2103 * request_nmi - allocate an interrupt line for NMI delivery
2104 * @irq: Interrupt line to allocate
2105 * @handler: Function to be called when the IRQ occurs.
2106 * Threaded handler for threaded interrupts.
2107 * @irqflags: Interrupt type flags
2108 * @name: An ascii name for the claiming device
2109 * @dev_id: A cookie passed back to the handler function
2111 * This call allocates interrupt resources and enables the
2112 * interrupt line and IRQ handling. It sets up the IRQ line
2113 * to be handled as an NMI.
2115 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2116 * cannot be threaded.
2118 * Interrupt lines requested for NMI delivering must produce per cpu
2119 * interrupts and have auto enabling setting disabled.
2121 * Dev_id must be globally unique. Normally the address of the
2122 * device data structure is used as the cookie. Since the handler
2123 * receives this value it makes sense to use it.
2125 * If the interrupt line cannot be used to deliver NMIs, function
2126 * will fail and return a negative value.
2128 int request_nmi(unsigned int irq, irq_handler_t handler,
2129 unsigned long irqflags, const char *name, void *dev_id)
2131 struct irqaction *action;
2132 struct irq_desc *desc;
2133 unsigned long flags;
2136 if (irq == IRQ_NOTCONNECTED)
2139 /* NMI cannot be shared, used for Polling */
2140 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2143 if (!(irqflags & IRQF_PERCPU))
2149 desc = irq_to_desc(irq);
2151 if (!desc || irq_settings_can_autoenable(desc) ||
2152 !irq_settings_can_request(desc) ||
2153 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2154 !irq_supports_nmi(desc))
2157 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2161 action->handler = handler;
2162 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2163 action->name = name;
2164 action->dev_id = dev_id;
2166 retval = irq_chip_pm_get(&desc->irq_data);
2170 retval = __setup_irq(irq, desc, action);
2174 raw_spin_lock_irqsave(&desc->lock, flags);
2176 /* Setup NMI state */
2177 desc->istate |= IRQS_NMI;
2178 retval = irq_nmi_setup(desc);
2180 __cleanup_nmi(irq, desc);
2181 raw_spin_unlock_irqrestore(&desc->lock, flags);
2185 raw_spin_unlock_irqrestore(&desc->lock, flags);
2190 irq_chip_pm_put(&desc->irq_data);
2197 void enable_percpu_irq(unsigned int irq, unsigned int type)
2199 unsigned int cpu = smp_processor_id();
2200 unsigned long flags;
2201 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2207 * If the trigger type is not specified by the caller, then
2208 * use the default for this interrupt.
2210 type &= IRQ_TYPE_SENSE_MASK;
2211 if (type == IRQ_TYPE_NONE)
2212 type = irqd_get_trigger_type(&desc->irq_data);
2214 if (type != IRQ_TYPE_NONE) {
2217 ret = __irq_set_trigger(desc, type);
2220 WARN(1, "failed to set type for IRQ%d\n", irq);
2225 irq_percpu_enable(desc, cpu);
2227 irq_put_desc_unlock(desc, flags);
2229 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2231 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2233 enable_percpu_irq(irq, type);
2237 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2238 * @irq: Linux irq number to check for
2240 * Must be called from a non migratable context. Returns the enable
2241 * state of a per cpu interrupt on the current cpu.
2243 bool irq_percpu_is_enabled(unsigned int irq)
2245 unsigned int cpu = smp_processor_id();
2246 struct irq_desc *desc;
2247 unsigned long flags;
2250 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2254 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2255 irq_put_desc_unlock(desc, flags);
2259 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2261 void disable_percpu_irq(unsigned int irq)
2263 unsigned int cpu = smp_processor_id();
2264 unsigned long flags;
2265 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2270 irq_percpu_disable(desc, cpu);
2271 irq_put_desc_unlock(desc, flags);
2273 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2275 void disable_percpu_nmi(unsigned int irq)
2277 disable_percpu_irq(irq);
2281 * Internal function to unregister a percpu irqaction.
2283 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2285 struct irq_desc *desc = irq_to_desc(irq);
2286 struct irqaction *action;
2287 unsigned long flags;
2289 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2294 raw_spin_lock_irqsave(&desc->lock, flags);
2296 action = desc->action;
2297 if (!action || action->percpu_dev_id != dev_id) {
2298 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2302 if (!cpumask_empty(desc->percpu_enabled)) {
2303 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2304 irq, cpumask_first(desc->percpu_enabled));
2308 /* Found it - now remove it from the list of entries: */
2309 desc->action = NULL;
2311 desc->istate &= ~IRQS_NMI;
2313 raw_spin_unlock_irqrestore(&desc->lock, flags);
2315 unregister_handler_proc(irq, action);
2317 irq_chip_pm_put(&desc->irq_data);
2318 module_put(desc->owner);
2322 raw_spin_unlock_irqrestore(&desc->lock, flags);
2327 * remove_percpu_irq - free a per-cpu interrupt
2328 * @irq: Interrupt line to free
2329 * @act: irqaction for the interrupt
2331 * Used to remove interrupts statically setup by the early boot process.
2333 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2335 struct irq_desc *desc = irq_to_desc(irq);
2337 if (desc && irq_settings_is_per_cpu_devid(desc))
2338 __free_percpu_irq(irq, act->percpu_dev_id);
2342 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2343 * @irq: Interrupt line to free
2344 * @dev_id: Device identity to free
2346 * Remove a percpu interrupt handler. The handler is removed, but
2347 * the interrupt line is not disabled. This must be done on each
2348 * CPU before calling this function. The function does not return
2349 * until any executing interrupts for this IRQ have completed.
2351 * This function must not be called from interrupt context.
2353 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2355 struct irq_desc *desc = irq_to_desc(irq);
2357 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2360 chip_bus_lock(desc);
2361 kfree(__free_percpu_irq(irq, dev_id));
2362 chip_bus_sync_unlock(desc);
2364 EXPORT_SYMBOL_GPL(free_percpu_irq);
2366 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2368 struct irq_desc *desc = irq_to_desc(irq);
2370 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2373 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2376 kfree(__free_percpu_irq(irq, dev_id));
2380 * setup_percpu_irq - setup a per-cpu interrupt
2381 * @irq: Interrupt line to setup
2382 * @act: irqaction for the interrupt
2384 * Used to statically setup per-cpu interrupts in the early boot process.
2386 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2388 struct irq_desc *desc = irq_to_desc(irq);
2391 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2394 retval = irq_chip_pm_get(&desc->irq_data);
2398 retval = __setup_irq(irq, desc, act);
2401 irq_chip_pm_put(&desc->irq_data);
2407 * __request_percpu_irq - allocate a percpu interrupt line
2408 * @irq: Interrupt line to allocate
2409 * @handler: Function to be called when the IRQ occurs.
2410 * @flags: Interrupt type flags (IRQF_TIMER only)
2411 * @devname: An ascii name for the claiming device
2412 * @dev_id: A percpu cookie passed back to the handler function
2414 * This call allocates interrupt resources and enables the
2415 * interrupt on the local CPU. If the interrupt is supposed to be
2416 * enabled on other CPUs, it has to be done on each CPU using
2417 * enable_percpu_irq().
2419 * Dev_id must be globally unique. It is a per-cpu variable, and
2420 * the handler gets called with the interrupted CPU's instance of
2423 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2424 unsigned long flags, const char *devname,
2425 void __percpu *dev_id)
2427 struct irqaction *action;
2428 struct irq_desc *desc;
2434 desc = irq_to_desc(irq);
2435 if (!desc || !irq_settings_can_request(desc) ||
2436 !irq_settings_is_per_cpu_devid(desc))
2439 if (flags && flags != IRQF_TIMER)
2442 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2446 action->handler = handler;
2447 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2448 action->name = devname;
2449 action->percpu_dev_id = dev_id;
2451 retval = irq_chip_pm_get(&desc->irq_data);
2457 retval = __setup_irq(irq, desc, action);
2460 irq_chip_pm_put(&desc->irq_data);
2466 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2469 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2470 * @irq: Interrupt line to allocate
2471 * @handler: Function to be called when the IRQ occurs.
2472 * @name: An ascii name for the claiming device
2473 * @dev_id: A percpu cookie passed back to the handler function
2475 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2476 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2477 * being enabled on the same CPU by using enable_percpu_nmi().
2479 * Dev_id must be globally unique. It is a per-cpu variable, and
2480 * the handler gets called with the interrupted CPU's instance of
2483 * Interrupt lines requested for NMI delivering should have auto enabling
2486 * If the interrupt line cannot be used to deliver NMIs, function
2487 * will fail returning a negative value.
2489 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2490 const char *name, void __percpu *dev_id)
2492 struct irqaction *action;
2493 struct irq_desc *desc;
2494 unsigned long flags;
2500 desc = irq_to_desc(irq);
2502 if (!desc || !irq_settings_can_request(desc) ||
2503 !irq_settings_is_per_cpu_devid(desc) ||
2504 irq_settings_can_autoenable(desc) ||
2505 !irq_supports_nmi(desc))
2508 /* The line cannot already be NMI */
2509 if (desc->istate & IRQS_NMI)
2512 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2516 action->handler = handler;
2517 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2519 action->name = name;
2520 action->percpu_dev_id = dev_id;
2522 retval = irq_chip_pm_get(&desc->irq_data);
2526 retval = __setup_irq(irq, desc, action);
2530 raw_spin_lock_irqsave(&desc->lock, flags);
2531 desc->istate |= IRQS_NMI;
2532 raw_spin_unlock_irqrestore(&desc->lock, flags);
2537 irq_chip_pm_put(&desc->irq_data);
2545 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2546 * @irq: Interrupt line to prepare for NMI delivery
2548 * This call prepares an interrupt line to deliver NMI on the current CPU,
2549 * before that interrupt line gets enabled with enable_percpu_nmi().
2551 * As a CPU local operation, this should be called from non-preemptible
2554 * If the interrupt line cannot be used to deliver NMIs, function
2555 * will fail returning a negative value.
2557 int prepare_percpu_nmi(unsigned int irq)
2559 unsigned long flags;
2560 struct irq_desc *desc;
2563 WARN_ON(preemptible());
2565 desc = irq_get_desc_lock(irq, &flags,
2566 IRQ_GET_DESC_CHECK_PERCPU);
2570 if (WARN(!(desc->istate & IRQS_NMI),
2571 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2577 ret = irq_nmi_setup(desc);
2579 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2584 irq_put_desc_unlock(desc, flags);
2589 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2590 * @irq: Interrupt line from which CPU local NMI configuration should be
2593 * This call undoes the setup done by prepare_percpu_nmi().
2595 * IRQ line should not be enabled for the current CPU.
2597 * As a CPU local operation, this should be called from non-preemptible
2600 void teardown_percpu_nmi(unsigned int irq)
2602 unsigned long flags;
2603 struct irq_desc *desc;
2605 WARN_ON(preemptible());
2607 desc = irq_get_desc_lock(irq, &flags,
2608 IRQ_GET_DESC_CHECK_PERCPU);
2612 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2615 irq_nmi_teardown(desc);
2617 irq_put_desc_unlock(desc, flags);
2620 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2623 struct irq_chip *chip;
2627 chip = irq_data_get_irq_chip(data);
2628 if (chip->irq_get_irqchip_state)
2630 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2631 data = data->parent_data;
2638 err = chip->irq_get_irqchip_state(data, which, state);
2643 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2644 * @irq: Interrupt line that is forwarded to a VM
2645 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2646 * @state: a pointer to a boolean where the state is to be storeed
2648 * This call snapshots the internal irqchip state of an
2649 * interrupt, returning into @state the bit corresponding to
2652 * This function should be called with preemption disabled if the
2653 * interrupt controller has per-cpu registers.
2655 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2658 struct irq_desc *desc;
2659 struct irq_data *data;
2660 unsigned long flags;
2663 desc = irq_get_desc_buslock(irq, &flags, 0);
2667 data = irq_desc_get_irq_data(desc);
2669 err = __irq_get_irqchip_state(data, which, state);
2671 irq_put_desc_busunlock(desc, flags);
2674 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2677 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2678 * @irq: Interrupt line that is forwarded to a VM
2679 * @which: State to be restored (one of IRQCHIP_STATE_*)
2680 * @val: Value corresponding to @which
2682 * This call sets the internal irqchip state of an interrupt,
2683 * depending on the value of @which.
2685 * This function should be called with preemption disabled if the
2686 * interrupt controller has per-cpu registers.
2688 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2691 struct irq_desc *desc;
2692 struct irq_data *data;
2693 struct irq_chip *chip;
2694 unsigned long flags;
2697 desc = irq_get_desc_buslock(irq, &flags, 0);
2701 data = irq_desc_get_irq_data(desc);
2704 chip = irq_data_get_irq_chip(data);
2705 if (chip->irq_set_irqchip_state)
2707 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2708 data = data->parent_data;
2715 err = chip->irq_set_irqchip_state(data, which, val);
2717 irq_put_desc_busunlock(desc, flags);
2720 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);