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 #if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
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.
1258 new->thread = get_task_struct(t);
1260 * Tell the thread to set its affinity. This is
1261 * important for shared interrupt handlers as we do
1262 * not invoke setup_affinity() for the secondary
1263 * handlers as everything is already set up. Even for
1264 * interrupts marked with IRQF_NO_BALANCE this is
1265 * correct as we want the thread to move to the cpu(s)
1266 * on which the requesting code placed the interrupt.
1268 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1273 * Internal function to register an irqaction - typically used to
1274 * allocate special interrupts that are part of the architecture.
1278 * desc->request_mutex Provides serialization against a concurrent free_irq()
1279 * chip_bus_lock Provides serialization for slow bus operations
1280 * desc->lock Provides serialization against hard interrupts
1282 * chip_bus_lock and desc->lock are sufficient for all other management and
1283 * interrupt related functions. desc->request_mutex solely serializes
1284 * request/free_irq().
1287 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1289 struct irqaction *old, **old_ptr;
1290 unsigned long flags, thread_mask = 0;
1291 int ret, nested, shared = 0;
1296 if (desc->irq_data.chip == &no_irq_chip)
1298 if (!try_module_get(desc->owner))
1304 * If the trigger type is not specified by the caller,
1305 * then use the default for this interrupt.
1307 if (!(new->flags & IRQF_TRIGGER_MASK))
1308 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1311 * Check whether the interrupt nests into another interrupt
1314 nested = irq_settings_is_nested_thread(desc);
1316 if (!new->thread_fn) {
1321 * Replace the primary handler which was provided from
1322 * the driver for non nested interrupt handling by the
1323 * dummy function which warns when called.
1325 new->handler = irq_nested_primary_handler;
1327 if (irq_settings_can_thread(desc)) {
1328 ret = irq_setup_forced_threading(new);
1335 * Create a handler thread when a thread function is supplied
1336 * and the interrupt does not nest into another interrupt
1339 if (new->thread_fn && !nested) {
1340 ret = setup_irq_thread(new, irq, false);
1343 if (new->secondary) {
1344 ret = setup_irq_thread(new->secondary, irq, true);
1351 * Drivers are often written to work w/o knowledge about the
1352 * underlying irq chip implementation, so a request for a
1353 * threaded irq without a primary hard irq context handler
1354 * requires the ONESHOT flag to be set. Some irq chips like
1355 * MSI based interrupts are per se one shot safe. Check the
1356 * chip flags, so we can avoid the unmask dance at the end of
1357 * the threaded handler for those.
1359 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1360 new->flags &= ~IRQF_ONESHOT;
1363 * Protects against a concurrent __free_irq() call which might wait
1364 * for synchronize_hardirq() to complete without holding the optional
1365 * chip bus lock and desc->lock. Also protects against handing out
1366 * a recycled oneshot thread_mask bit while it's still in use by
1367 * its previous owner.
1369 mutex_lock(&desc->request_mutex);
1372 * Acquire bus lock as the irq_request_resources() callback below
1373 * might rely on the serialization or the magic power management
1374 * functions which are abusing the irq_bus_lock() callback,
1376 chip_bus_lock(desc);
1378 /* First installed action requests resources. */
1379 if (!desc->action) {
1380 ret = irq_request_resources(desc);
1382 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1383 new->name, irq, desc->irq_data.chip->name);
1384 goto out_bus_unlock;
1389 * The following block of code has to be executed atomically
1390 * protected against a concurrent interrupt and any of the other
1391 * management calls which are not serialized via
1392 * desc->request_mutex or the optional bus lock.
1394 raw_spin_lock_irqsave(&desc->lock, flags);
1395 old_ptr = &desc->action;
1399 * Can't share interrupts unless both agree to and are
1400 * the same type (level, edge, polarity). So both flag
1401 * fields must have IRQF_SHARED set and the bits which
1402 * set the trigger type must match. Also all must
1404 * Interrupt lines used for NMIs cannot be shared.
1406 unsigned int oldtype;
1408 if (desc->istate & IRQS_NMI) {
1409 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1410 new->name, irq, desc->irq_data.chip->name);
1416 * If nobody did set the configuration before, inherit
1417 * the one provided by the requester.
1419 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1420 oldtype = irqd_get_trigger_type(&desc->irq_data);
1422 oldtype = new->flags & IRQF_TRIGGER_MASK;
1423 irqd_set_trigger_type(&desc->irq_data, oldtype);
1426 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1427 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1428 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1431 /* All handlers must agree on per-cpuness */
1432 if ((old->flags & IRQF_PERCPU) !=
1433 (new->flags & IRQF_PERCPU))
1436 /* add new interrupt at end of irq queue */
1439 * Or all existing action->thread_mask bits,
1440 * so we can find the next zero bit for this
1443 thread_mask |= old->thread_mask;
1444 old_ptr = &old->next;
1451 * Setup the thread mask for this irqaction for ONESHOT. For
1452 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1453 * conditional in irq_wake_thread().
1455 if (new->flags & IRQF_ONESHOT) {
1457 * Unlikely to have 32 resp 64 irqs sharing one line,
1460 if (thread_mask == ~0UL) {
1465 * The thread_mask for the action is or'ed to
1466 * desc->thread_active to indicate that the
1467 * IRQF_ONESHOT thread handler has been woken, but not
1468 * yet finished. The bit is cleared when a thread
1469 * completes. When all threads of a shared interrupt
1470 * line have completed desc->threads_active becomes
1471 * zero and the interrupt line is unmasked. See
1472 * handle.c:irq_wake_thread() for further information.
1474 * If no thread is woken by primary (hard irq context)
1475 * interrupt handlers, then desc->threads_active is
1476 * also checked for zero to unmask the irq line in the
1477 * affected hard irq flow handlers
1478 * (handle_[fasteoi|level]_irq).
1480 * The new action gets the first zero bit of
1481 * thread_mask assigned. See the loop above which or's
1482 * all existing action->thread_mask bits.
1484 new->thread_mask = 1UL << ffz(thread_mask);
1486 } else if (new->handler == irq_default_primary_handler &&
1487 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1489 * The interrupt was requested with handler = NULL, so
1490 * we use the default primary handler for it. But it
1491 * does not have the oneshot flag set. In combination
1492 * with level interrupts this is deadly, because the
1493 * default primary handler just wakes the thread, then
1494 * the irq lines is reenabled, but the device still
1495 * has the level irq asserted. Rinse and repeat....
1497 * While this works for edge type interrupts, we play
1498 * it safe and reject unconditionally because we can't
1499 * say for sure which type this interrupt really
1500 * has. The type flags are unreliable as the
1501 * underlying chip implementation can override them.
1503 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1510 init_waitqueue_head(&desc->wait_for_threads);
1512 /* Setup the type (level, edge polarity) if configured: */
1513 if (new->flags & IRQF_TRIGGER_MASK) {
1514 ret = __irq_set_trigger(desc,
1515 new->flags & IRQF_TRIGGER_MASK);
1522 * Activate the interrupt. That activation must happen
1523 * independently of IRQ_NOAUTOEN. request_irq() can fail
1524 * and the callers are supposed to handle
1525 * that. enable_irq() of an interrupt requested with
1526 * IRQ_NOAUTOEN is not supposed to fail. The activation
1527 * keeps it in shutdown mode, it merily associates
1528 * resources if necessary and if that's not possible it
1529 * fails. Interrupts which are in managed shutdown mode
1530 * will simply ignore that activation request.
1532 ret = irq_activate(desc);
1536 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1537 IRQS_ONESHOT | IRQS_WAITING);
1538 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1540 if (new->flags & IRQF_PERCPU) {
1541 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1542 irq_settings_set_per_cpu(desc);
1545 if (new->flags & IRQF_ONESHOT)
1546 desc->istate |= IRQS_ONESHOT;
1548 /* Exclude IRQ from balancing if requested */
1549 if (new->flags & IRQF_NOBALANCING) {
1550 irq_settings_set_no_balancing(desc);
1551 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1554 if (irq_settings_can_autoenable(desc)) {
1555 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1558 * Shared interrupts do not go well with disabling
1559 * auto enable. The sharing interrupt might request
1560 * it while it's still disabled and then wait for
1561 * interrupts forever.
1563 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1564 /* Undo nested disables: */
1568 } else if (new->flags & IRQF_TRIGGER_MASK) {
1569 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1570 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1573 /* hope the handler works with current trigger mode */
1574 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1580 irq_pm_install_action(desc, new);
1582 /* Reset broken irq detection when installing new handler */
1583 desc->irq_count = 0;
1584 desc->irqs_unhandled = 0;
1587 * Check whether we disabled the irq via the spurious handler
1588 * before. Reenable it and give it another chance.
1590 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1591 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1595 raw_spin_unlock_irqrestore(&desc->lock, flags);
1596 chip_bus_sync_unlock(desc);
1597 mutex_unlock(&desc->request_mutex);
1599 irq_setup_timings(desc, new);
1602 * Strictly no need to wake it up, but hung_task complains
1603 * when no hard interrupt wakes the thread up.
1606 wake_up_process(new->thread);
1608 wake_up_process(new->secondary->thread);
1610 register_irq_proc(irq, desc);
1612 register_handler_proc(irq, new);
1616 if (!(new->flags & IRQF_PROBE_SHARED)) {
1617 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1618 irq, new->flags, new->name, old->flags, old->name);
1619 #ifdef CONFIG_DEBUG_SHIRQ
1626 raw_spin_unlock_irqrestore(&desc->lock, flags);
1629 irq_release_resources(desc);
1631 chip_bus_sync_unlock(desc);
1632 mutex_unlock(&desc->request_mutex);
1636 struct task_struct *t = new->thread;
1642 if (new->secondary && new->secondary->thread) {
1643 struct task_struct *t = new->secondary->thread;
1645 new->secondary->thread = NULL;
1650 module_put(desc->owner);
1655 * setup_irq - setup an interrupt
1656 * @irq: Interrupt line to setup
1657 * @act: irqaction for the interrupt
1659 * Used to statically setup interrupts in the early boot process.
1661 int setup_irq(unsigned int irq, struct irqaction *act)
1664 struct irq_desc *desc = irq_to_desc(irq);
1666 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1669 retval = irq_chip_pm_get(&desc->irq_data);
1673 retval = __setup_irq(irq, desc, act);
1676 irq_chip_pm_put(&desc->irq_data);
1680 EXPORT_SYMBOL_GPL(setup_irq);
1683 * Internal function to unregister an irqaction - used to free
1684 * regular and special interrupts that are part of the architecture.
1686 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1688 unsigned irq = desc->irq_data.irq;
1689 struct irqaction *action, **action_ptr;
1690 unsigned long flags;
1692 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1694 mutex_lock(&desc->request_mutex);
1695 chip_bus_lock(desc);
1696 raw_spin_lock_irqsave(&desc->lock, flags);
1699 * There can be multiple actions per IRQ descriptor, find the right
1700 * one based on the dev_id:
1702 action_ptr = &desc->action;
1704 action = *action_ptr;
1707 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1708 raw_spin_unlock_irqrestore(&desc->lock, flags);
1709 chip_bus_sync_unlock(desc);
1710 mutex_unlock(&desc->request_mutex);
1714 if (action->dev_id == dev_id)
1716 action_ptr = &action->next;
1719 /* Found it - now remove it from the list of entries: */
1720 *action_ptr = action->next;
1722 irq_pm_remove_action(desc, action);
1724 /* If this was the last handler, shut down the IRQ line: */
1725 if (!desc->action) {
1726 irq_settings_clr_disable_unlazy(desc);
1727 /* Only shutdown. Deactivate after synchronize_hardirq() */
1732 /* make sure affinity_hint is cleaned up */
1733 if (WARN_ON_ONCE(desc->affinity_hint))
1734 desc->affinity_hint = NULL;
1737 raw_spin_unlock_irqrestore(&desc->lock, flags);
1739 * Drop bus_lock here so the changes which were done in the chip
1740 * callbacks above are synced out to the irq chips which hang
1741 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1743 * Aside of that the bus_lock can also be taken from the threaded
1744 * handler in irq_finalize_oneshot() which results in a deadlock
1745 * because kthread_stop() would wait forever for the thread to
1746 * complete, which is blocked on the bus lock.
1748 * The still held desc->request_mutex() protects against a
1749 * concurrent request_irq() of this irq so the release of resources
1750 * and timing data is properly serialized.
1752 chip_bus_sync_unlock(desc);
1754 unregister_handler_proc(irq, action);
1757 * Make sure it's not being used on another CPU and if the chip
1758 * supports it also make sure that there is no (not yet serviced)
1759 * interrupt in flight at the hardware level.
1761 __synchronize_hardirq(desc, true);
1763 #ifdef CONFIG_DEBUG_SHIRQ
1765 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1766 * event to happen even now it's being freed, so let's make sure that
1767 * is so by doing an extra call to the handler ....
1769 * ( We do this after actually deregistering it, to make sure that a
1770 * 'real' IRQ doesn't run in parallel with our fake. )
1772 if (action->flags & IRQF_SHARED) {
1773 local_irq_save(flags);
1774 action->handler(irq, dev_id);
1775 local_irq_restore(flags);
1780 * The action has already been removed above, but the thread writes
1781 * its oneshot mask bit when it completes. Though request_mutex is
1782 * held across this which prevents __setup_irq() from handing out
1783 * the same bit to a newly requested action.
1785 if (action->thread) {
1786 kthread_stop(action->thread);
1787 put_task_struct(action->thread);
1788 if (action->secondary && action->secondary->thread) {
1789 kthread_stop(action->secondary->thread);
1790 put_task_struct(action->secondary->thread);
1794 /* Last action releases resources */
1795 if (!desc->action) {
1797 * Reaquire bus lock as irq_release_resources() might
1798 * require it to deallocate resources over the slow bus.
1800 chip_bus_lock(desc);
1802 * There is no interrupt on the fly anymore. Deactivate it
1805 raw_spin_lock_irqsave(&desc->lock, flags);
1806 irq_domain_deactivate_irq(&desc->irq_data);
1807 raw_spin_unlock_irqrestore(&desc->lock, flags);
1809 irq_release_resources(desc);
1810 chip_bus_sync_unlock(desc);
1811 irq_remove_timings(desc);
1814 mutex_unlock(&desc->request_mutex);
1816 irq_chip_pm_put(&desc->irq_data);
1817 module_put(desc->owner);
1818 kfree(action->secondary);
1823 * remove_irq - free an interrupt
1824 * @irq: Interrupt line to free
1825 * @act: irqaction for the interrupt
1827 * Used to remove interrupts statically setup by the early boot process.
1829 void remove_irq(unsigned int irq, struct irqaction *act)
1831 struct irq_desc *desc = irq_to_desc(irq);
1833 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1834 __free_irq(desc, act->dev_id);
1836 EXPORT_SYMBOL_GPL(remove_irq);
1839 * free_irq - free an interrupt allocated with request_irq
1840 * @irq: Interrupt line to free
1841 * @dev_id: Device identity to free
1843 * Remove an interrupt handler. The handler is removed and if the
1844 * interrupt line is no longer in use by any driver it is disabled.
1845 * On a shared IRQ the caller must ensure the interrupt is disabled
1846 * on the card it drives before calling this function. The function
1847 * does not return until any executing interrupts for this IRQ
1850 * This function must not be called from interrupt context.
1852 * Returns the devname argument passed to request_irq.
1854 const void *free_irq(unsigned int irq, void *dev_id)
1856 struct irq_desc *desc = irq_to_desc(irq);
1857 struct irqaction *action;
1858 const char *devname;
1860 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1864 if (WARN_ON(desc->affinity_notify))
1865 desc->affinity_notify = NULL;
1868 action = __free_irq(desc, dev_id);
1873 devname = action->name;
1877 EXPORT_SYMBOL(free_irq);
1879 /* This function must be called with desc->lock held */
1880 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1882 const char *devname = NULL;
1884 desc->istate &= ~IRQS_NMI;
1886 if (!WARN_ON(desc->action == NULL)) {
1887 irq_pm_remove_action(desc, desc->action);
1888 devname = desc->action->name;
1889 unregister_handler_proc(irq, desc->action);
1891 kfree(desc->action);
1892 desc->action = NULL;
1895 irq_settings_clr_disable_unlazy(desc);
1896 irq_shutdown_and_deactivate(desc);
1898 irq_release_resources(desc);
1900 irq_chip_pm_put(&desc->irq_data);
1901 module_put(desc->owner);
1906 const void *free_nmi(unsigned int irq, void *dev_id)
1908 struct irq_desc *desc = irq_to_desc(irq);
1909 unsigned long flags;
1910 const void *devname;
1912 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1915 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1918 /* NMI still enabled */
1919 if (WARN_ON(desc->depth == 0))
1920 disable_nmi_nosync(irq);
1922 raw_spin_lock_irqsave(&desc->lock, flags);
1924 irq_nmi_teardown(desc);
1925 devname = __cleanup_nmi(irq, desc);
1927 raw_spin_unlock_irqrestore(&desc->lock, flags);
1933 * request_threaded_irq - allocate an interrupt line
1934 * @irq: Interrupt line to allocate
1935 * @handler: Function to be called when the IRQ occurs.
1936 * Primary handler for threaded interrupts
1937 * If NULL and thread_fn != NULL the default
1938 * primary handler is installed
1939 * @thread_fn: Function called from the irq handler thread
1940 * If NULL, no irq thread is created
1941 * @irqflags: Interrupt type flags
1942 * @devname: An ascii name for the claiming device
1943 * @dev_id: A cookie passed back to the handler function
1945 * This call allocates interrupt resources and enables the
1946 * interrupt line and IRQ handling. From the point this
1947 * call is made your handler function may be invoked. Since
1948 * your handler function must clear any interrupt the board
1949 * raises, you must take care both to initialise your hardware
1950 * and to set up the interrupt handler in the right order.
1952 * If you want to set up a threaded irq handler for your device
1953 * then you need to supply @handler and @thread_fn. @handler is
1954 * still called in hard interrupt context and has to check
1955 * whether the interrupt originates from the device. If yes it
1956 * needs to disable the interrupt on the device and return
1957 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1958 * @thread_fn. This split handler design is necessary to support
1959 * shared interrupts.
1961 * Dev_id must be globally unique. Normally the address of the
1962 * device data structure is used as the cookie. Since the handler
1963 * receives this value it makes sense to use it.
1965 * If your interrupt is shared you must pass a non NULL dev_id
1966 * as this is required when freeing the interrupt.
1970 * IRQF_SHARED Interrupt is shared
1971 * IRQF_TRIGGER_* Specify active edge(s) or level
1974 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1975 irq_handler_t thread_fn, unsigned long irqflags,
1976 const char *devname, void *dev_id)
1978 struct irqaction *action;
1979 struct irq_desc *desc;
1982 if (irq == IRQ_NOTCONNECTED)
1986 * Sanity-check: shared interrupts must pass in a real dev-ID,
1987 * otherwise we'll have trouble later trying to figure out
1988 * which interrupt is which (messes up the interrupt freeing
1991 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1992 * it cannot be set along with IRQF_NO_SUSPEND.
1994 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1995 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1996 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1999 desc = irq_to_desc(irq);
2003 if (!irq_settings_can_request(desc) ||
2004 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2010 handler = irq_default_primary_handler;
2013 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2017 action->handler = handler;
2018 action->thread_fn = thread_fn;
2019 action->flags = irqflags;
2020 action->name = devname;
2021 action->dev_id = dev_id;
2023 retval = irq_chip_pm_get(&desc->irq_data);
2029 retval = __setup_irq(irq, desc, action);
2032 irq_chip_pm_put(&desc->irq_data);
2033 kfree(action->secondary);
2037 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2038 if (!retval && (irqflags & IRQF_SHARED)) {
2040 * It's a shared IRQ -- the driver ought to be prepared for it
2041 * to happen immediately, so let's make sure....
2042 * We disable the irq to make sure that a 'real' IRQ doesn't
2043 * run in parallel with our fake.
2045 unsigned long flags;
2048 local_irq_save(flags);
2050 handler(irq, dev_id);
2052 local_irq_restore(flags);
2058 EXPORT_SYMBOL(request_threaded_irq);
2061 * request_any_context_irq - allocate an interrupt line
2062 * @irq: Interrupt line to allocate
2063 * @handler: Function to be called when the IRQ occurs.
2064 * Threaded handler for threaded interrupts.
2065 * @flags: Interrupt type flags
2066 * @name: An ascii name for the claiming device
2067 * @dev_id: A cookie passed back to the handler function
2069 * This call allocates interrupt resources and enables the
2070 * interrupt line and IRQ handling. It selects either a
2071 * hardirq or threaded handling method depending on the
2074 * On failure, it returns a negative value. On success,
2075 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2077 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2078 unsigned long flags, const char *name, void *dev_id)
2080 struct irq_desc *desc;
2083 if (irq == IRQ_NOTCONNECTED)
2086 desc = irq_to_desc(irq);
2090 if (irq_settings_is_nested_thread(desc)) {
2091 ret = request_threaded_irq(irq, NULL, handler,
2092 flags, name, dev_id);
2093 return !ret ? IRQC_IS_NESTED : ret;
2096 ret = request_irq(irq, handler, flags, name, dev_id);
2097 return !ret ? IRQC_IS_HARDIRQ : ret;
2099 EXPORT_SYMBOL_GPL(request_any_context_irq);
2102 * request_nmi - allocate an interrupt line for NMI delivery
2103 * @irq: Interrupt line to allocate
2104 * @handler: Function to be called when the IRQ occurs.
2105 * Threaded handler for threaded interrupts.
2106 * @irqflags: Interrupt type flags
2107 * @name: An ascii name for the claiming device
2108 * @dev_id: A cookie passed back to the handler function
2110 * This call allocates interrupt resources and enables the
2111 * interrupt line and IRQ handling. It sets up the IRQ line
2112 * to be handled as an NMI.
2114 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2115 * cannot be threaded.
2117 * Interrupt lines requested for NMI delivering must produce per cpu
2118 * interrupts and have auto enabling setting disabled.
2120 * Dev_id must be globally unique. Normally the address of the
2121 * device data structure is used as the cookie. Since the handler
2122 * receives this value it makes sense to use it.
2124 * If the interrupt line cannot be used to deliver NMIs, function
2125 * will fail and return a negative value.
2127 int request_nmi(unsigned int irq, irq_handler_t handler,
2128 unsigned long irqflags, const char *name, void *dev_id)
2130 struct irqaction *action;
2131 struct irq_desc *desc;
2132 unsigned long flags;
2135 if (irq == IRQ_NOTCONNECTED)
2138 /* NMI cannot be shared, used for Polling */
2139 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2142 if (!(irqflags & IRQF_PERCPU))
2148 desc = irq_to_desc(irq);
2150 if (!desc || irq_settings_can_autoenable(desc) ||
2151 !irq_settings_can_request(desc) ||
2152 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2153 !irq_supports_nmi(desc))
2156 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2160 action->handler = handler;
2161 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2162 action->name = name;
2163 action->dev_id = dev_id;
2165 retval = irq_chip_pm_get(&desc->irq_data);
2169 retval = __setup_irq(irq, desc, action);
2173 raw_spin_lock_irqsave(&desc->lock, flags);
2175 /* Setup NMI state */
2176 desc->istate |= IRQS_NMI;
2177 retval = irq_nmi_setup(desc);
2179 __cleanup_nmi(irq, desc);
2180 raw_spin_unlock_irqrestore(&desc->lock, flags);
2184 raw_spin_unlock_irqrestore(&desc->lock, flags);
2189 irq_chip_pm_put(&desc->irq_data);
2196 void enable_percpu_irq(unsigned int irq, unsigned int type)
2198 unsigned int cpu = smp_processor_id();
2199 unsigned long flags;
2200 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2206 * If the trigger type is not specified by the caller, then
2207 * use the default for this interrupt.
2209 type &= IRQ_TYPE_SENSE_MASK;
2210 if (type == IRQ_TYPE_NONE)
2211 type = irqd_get_trigger_type(&desc->irq_data);
2213 if (type != IRQ_TYPE_NONE) {
2216 ret = __irq_set_trigger(desc, type);
2219 WARN(1, "failed to set type for IRQ%d\n", irq);
2224 irq_percpu_enable(desc, cpu);
2226 irq_put_desc_unlock(desc, flags);
2228 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2230 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2232 enable_percpu_irq(irq, type);
2236 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2237 * @irq: Linux irq number to check for
2239 * Must be called from a non migratable context. Returns the enable
2240 * state of a per cpu interrupt on the current cpu.
2242 bool irq_percpu_is_enabled(unsigned int irq)
2244 unsigned int cpu = smp_processor_id();
2245 struct irq_desc *desc;
2246 unsigned long flags;
2249 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2253 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2254 irq_put_desc_unlock(desc, flags);
2258 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2260 void disable_percpu_irq(unsigned int irq)
2262 unsigned int cpu = smp_processor_id();
2263 unsigned long flags;
2264 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2269 irq_percpu_disable(desc, cpu);
2270 irq_put_desc_unlock(desc, flags);
2272 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2274 void disable_percpu_nmi(unsigned int irq)
2276 disable_percpu_irq(irq);
2280 * Internal function to unregister a percpu irqaction.
2282 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2284 struct irq_desc *desc = irq_to_desc(irq);
2285 struct irqaction *action;
2286 unsigned long flags;
2288 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2293 raw_spin_lock_irqsave(&desc->lock, flags);
2295 action = desc->action;
2296 if (!action || action->percpu_dev_id != dev_id) {
2297 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2301 if (!cpumask_empty(desc->percpu_enabled)) {
2302 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2303 irq, cpumask_first(desc->percpu_enabled));
2307 /* Found it - now remove it from the list of entries: */
2308 desc->action = NULL;
2310 desc->istate &= ~IRQS_NMI;
2312 raw_spin_unlock_irqrestore(&desc->lock, flags);
2314 unregister_handler_proc(irq, action);
2316 irq_chip_pm_put(&desc->irq_data);
2317 module_put(desc->owner);
2321 raw_spin_unlock_irqrestore(&desc->lock, flags);
2326 * remove_percpu_irq - free a per-cpu interrupt
2327 * @irq: Interrupt line to free
2328 * @act: irqaction for the interrupt
2330 * Used to remove interrupts statically setup by the early boot process.
2332 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2334 struct irq_desc *desc = irq_to_desc(irq);
2336 if (desc && irq_settings_is_per_cpu_devid(desc))
2337 __free_percpu_irq(irq, act->percpu_dev_id);
2341 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2342 * @irq: Interrupt line to free
2343 * @dev_id: Device identity to free
2345 * Remove a percpu interrupt handler. The handler is removed, but
2346 * the interrupt line is not disabled. This must be done on each
2347 * CPU before calling this function. The function does not return
2348 * until any executing interrupts for this IRQ have completed.
2350 * This function must not be called from interrupt context.
2352 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2354 struct irq_desc *desc = irq_to_desc(irq);
2356 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2359 chip_bus_lock(desc);
2360 kfree(__free_percpu_irq(irq, dev_id));
2361 chip_bus_sync_unlock(desc);
2363 EXPORT_SYMBOL_GPL(free_percpu_irq);
2365 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2367 struct irq_desc *desc = irq_to_desc(irq);
2369 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2372 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2375 kfree(__free_percpu_irq(irq, dev_id));
2379 * setup_percpu_irq - setup a per-cpu interrupt
2380 * @irq: Interrupt line to setup
2381 * @act: irqaction for the interrupt
2383 * Used to statically setup per-cpu interrupts in the early boot process.
2385 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2387 struct irq_desc *desc = irq_to_desc(irq);
2390 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2393 retval = irq_chip_pm_get(&desc->irq_data);
2397 retval = __setup_irq(irq, desc, act);
2400 irq_chip_pm_put(&desc->irq_data);
2406 * __request_percpu_irq - allocate a percpu interrupt line
2407 * @irq: Interrupt line to allocate
2408 * @handler: Function to be called when the IRQ occurs.
2409 * @flags: Interrupt type flags (IRQF_TIMER only)
2410 * @devname: An ascii name for the claiming device
2411 * @dev_id: A percpu cookie passed back to the handler function
2413 * This call allocates interrupt resources and enables the
2414 * interrupt on the local CPU. If the interrupt is supposed to be
2415 * enabled on other CPUs, it has to be done on each CPU using
2416 * enable_percpu_irq().
2418 * Dev_id must be globally unique. It is a per-cpu variable, and
2419 * the handler gets called with the interrupted CPU's instance of
2422 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2423 unsigned long flags, const char *devname,
2424 void __percpu *dev_id)
2426 struct irqaction *action;
2427 struct irq_desc *desc;
2433 desc = irq_to_desc(irq);
2434 if (!desc || !irq_settings_can_request(desc) ||
2435 !irq_settings_is_per_cpu_devid(desc))
2438 if (flags && flags != IRQF_TIMER)
2441 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2445 action->handler = handler;
2446 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2447 action->name = devname;
2448 action->percpu_dev_id = dev_id;
2450 retval = irq_chip_pm_get(&desc->irq_data);
2456 retval = __setup_irq(irq, desc, action);
2459 irq_chip_pm_put(&desc->irq_data);
2465 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2468 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2469 * @irq: Interrupt line to allocate
2470 * @handler: Function to be called when the IRQ occurs.
2471 * @name: An ascii name for the claiming device
2472 * @dev_id: A percpu cookie passed back to the handler function
2474 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2475 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2476 * being enabled on the same CPU by using enable_percpu_nmi().
2478 * Dev_id must be globally unique. It is a per-cpu variable, and
2479 * the handler gets called with the interrupted CPU's instance of
2482 * Interrupt lines requested for NMI delivering should have auto enabling
2485 * If the interrupt line cannot be used to deliver NMIs, function
2486 * will fail returning a negative value.
2488 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2489 const char *name, void __percpu *dev_id)
2491 struct irqaction *action;
2492 struct irq_desc *desc;
2493 unsigned long flags;
2499 desc = irq_to_desc(irq);
2501 if (!desc || !irq_settings_can_request(desc) ||
2502 !irq_settings_is_per_cpu_devid(desc) ||
2503 irq_settings_can_autoenable(desc) ||
2504 !irq_supports_nmi(desc))
2507 /* The line cannot already be NMI */
2508 if (desc->istate & IRQS_NMI)
2511 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2515 action->handler = handler;
2516 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2518 action->name = name;
2519 action->percpu_dev_id = dev_id;
2521 retval = irq_chip_pm_get(&desc->irq_data);
2525 retval = __setup_irq(irq, desc, action);
2529 raw_spin_lock_irqsave(&desc->lock, flags);
2530 desc->istate |= IRQS_NMI;
2531 raw_spin_unlock_irqrestore(&desc->lock, flags);
2536 irq_chip_pm_put(&desc->irq_data);
2544 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2545 * @irq: Interrupt line to prepare for NMI delivery
2547 * This call prepares an interrupt line to deliver NMI on the current CPU,
2548 * before that interrupt line gets enabled with enable_percpu_nmi().
2550 * As a CPU local operation, this should be called from non-preemptible
2553 * If the interrupt line cannot be used to deliver NMIs, function
2554 * will fail returning a negative value.
2556 int prepare_percpu_nmi(unsigned int irq)
2558 unsigned long flags;
2559 struct irq_desc *desc;
2562 WARN_ON(preemptible());
2564 desc = irq_get_desc_lock(irq, &flags,
2565 IRQ_GET_DESC_CHECK_PERCPU);
2569 if (WARN(!(desc->istate & IRQS_NMI),
2570 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2576 ret = irq_nmi_setup(desc);
2578 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2583 irq_put_desc_unlock(desc, flags);
2588 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2589 * @irq: Interrupt line from which CPU local NMI configuration should be
2592 * This call undoes the setup done by prepare_percpu_nmi().
2594 * IRQ line should not be enabled for the current CPU.
2596 * As a CPU local operation, this should be called from non-preemptible
2599 void teardown_percpu_nmi(unsigned int irq)
2601 unsigned long flags;
2602 struct irq_desc *desc;
2604 WARN_ON(preemptible());
2606 desc = irq_get_desc_lock(irq, &flags,
2607 IRQ_GET_DESC_CHECK_PERCPU);
2611 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2614 irq_nmi_teardown(desc);
2616 irq_put_desc_unlock(desc, flags);
2619 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2622 struct irq_chip *chip;
2626 chip = irq_data_get_irq_chip(data);
2627 if (chip->irq_get_irqchip_state)
2629 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2630 data = data->parent_data;
2637 err = chip->irq_get_irqchip_state(data, which, state);
2642 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2643 * @irq: Interrupt line that is forwarded to a VM
2644 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2645 * @state: a pointer to a boolean where the state is to be storeed
2647 * This call snapshots the internal irqchip state of an
2648 * interrupt, returning into @state the bit corresponding to
2651 * This function should be called with preemption disabled if the
2652 * interrupt controller has per-cpu registers.
2654 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2657 struct irq_desc *desc;
2658 struct irq_data *data;
2659 unsigned long flags;
2662 desc = irq_get_desc_buslock(irq, &flags, 0);
2666 data = irq_desc_get_irq_data(desc);
2668 err = __irq_get_irqchip_state(data, which, state);
2670 irq_put_desc_busunlock(desc, flags);
2673 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2676 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2677 * @irq: Interrupt line that is forwarded to a VM
2678 * @which: State to be restored (one of IRQCHIP_STATE_*)
2679 * @val: Value corresponding to @which
2681 * This call sets the internal irqchip state of an interrupt,
2682 * depending on the value of @which.
2684 * This function should be called with preemption disabled if the
2685 * interrupt controller has per-cpu registers.
2687 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2690 struct irq_desc *desc;
2691 struct irq_data *data;
2692 struct irq_chip *chip;
2693 unsigned long flags;
2696 desc = irq_get_desc_buslock(irq, &flags, 0);
2700 data = irq_desc_get_irq_data(desc);
2703 chip = irq_data_get_irq_chip(data);
2704 if (chip->irq_set_irqchip_state)
2706 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2707 data = data->parent_data;
2714 err = chip->irq_set_irqchip_state(data, which, val);
2716 irq_put_desc_busunlock(desc, flags);
2719 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);