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 if (!schedule_work(&desc->affinity_notify->work)) {
288 /* Work was already scheduled, drop our extra ref */
289 kref_put(&desc->affinity_notify->kref,
290 desc->affinity_notify->release);
293 irqd_set(data, IRQD_AFFINITY_SET);
298 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
300 struct irq_desc *desc = irq_to_desc(irq);
307 raw_spin_lock_irqsave(&desc->lock, flags);
308 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
309 raw_spin_unlock_irqrestore(&desc->lock, flags);
313 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
316 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
320 desc->affinity_hint = m;
321 irq_put_desc_unlock(desc, flags);
322 /* set the initial affinity to prevent every interrupt being on CPU0 */
324 __irq_set_affinity(irq, m, false);
327 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
329 static void irq_affinity_notify(struct work_struct *work)
331 struct irq_affinity_notify *notify =
332 container_of(work, struct irq_affinity_notify, work);
333 struct irq_desc *desc = irq_to_desc(notify->irq);
334 cpumask_var_t cpumask;
337 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
340 raw_spin_lock_irqsave(&desc->lock, flags);
341 if (irq_move_pending(&desc->irq_data))
342 irq_get_pending(cpumask, desc);
344 cpumask_copy(cpumask, desc->irq_common_data.affinity);
345 raw_spin_unlock_irqrestore(&desc->lock, flags);
347 notify->notify(notify, cpumask);
349 free_cpumask_var(cpumask);
351 kref_put(¬ify->kref, notify->release);
355 * irq_set_affinity_notifier - control notification of IRQ affinity changes
356 * @irq: Interrupt for which to enable/disable notification
357 * @notify: Context for notification, or %NULL to disable
358 * notification. Function pointers must be initialised;
359 * the other fields will be initialised by this function.
361 * Must be called in process context. Notification may only be enabled
362 * after the IRQ is allocated and must be disabled before the IRQ is
363 * freed using free_irq().
366 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
368 struct irq_desc *desc = irq_to_desc(irq);
369 struct irq_affinity_notify *old_notify;
372 /* The release function is promised process context */
375 if (!desc || desc->istate & IRQS_NMI)
378 /* Complete initialisation of *notify */
381 kref_init(¬ify->kref);
382 INIT_WORK(¬ify->work, irq_affinity_notify);
385 raw_spin_lock_irqsave(&desc->lock, flags);
386 old_notify = desc->affinity_notify;
387 desc->affinity_notify = notify;
388 raw_spin_unlock_irqrestore(&desc->lock, flags);
391 if (cancel_work_sync(&old_notify->work)) {
392 /* Pending work had a ref, put that one too */
393 kref_put(&old_notify->kref, old_notify->release);
395 kref_put(&old_notify->kref, old_notify->release);
400 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
402 #ifndef CONFIG_AUTO_IRQ_AFFINITY
404 * Generic version of the affinity autoselector.
406 int irq_setup_affinity(struct irq_desc *desc)
408 struct cpumask *set = irq_default_affinity;
409 int ret, node = irq_desc_get_node(desc);
410 static DEFINE_RAW_SPINLOCK(mask_lock);
411 static struct cpumask mask;
413 /* Excludes PER_CPU and NO_BALANCE interrupts */
414 if (!__irq_can_set_affinity(desc))
417 raw_spin_lock(&mask_lock);
419 * Preserve the managed affinity setting and a userspace affinity
420 * setup, but make sure that one of the targets is online.
422 if (irqd_affinity_is_managed(&desc->irq_data) ||
423 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
424 if (cpumask_intersects(desc->irq_common_data.affinity,
426 set = desc->irq_common_data.affinity;
428 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
431 cpumask_and(&mask, cpu_online_mask, set);
432 if (cpumask_empty(&mask))
433 cpumask_copy(&mask, cpu_online_mask);
435 if (node != NUMA_NO_NODE) {
436 const struct cpumask *nodemask = cpumask_of_node(node);
438 /* make sure at least one of the cpus in nodemask is online */
439 if (cpumask_intersects(&mask, nodemask))
440 cpumask_and(&mask, &mask, nodemask);
442 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
443 raw_spin_unlock(&mask_lock);
447 /* Wrapper for ALPHA specific affinity selector magic */
448 int irq_setup_affinity(struct irq_desc *desc)
450 return irq_select_affinity(irq_desc_get_irq(desc));
452 #endif /* CONFIG_AUTO_IRQ_AFFINITY */
453 #endif /* CONFIG_SMP */
457 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
458 * @irq: interrupt number to set affinity
459 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
460 * specific data for percpu_devid interrupts
462 * This function uses the vCPU specific data to set the vCPU
463 * affinity for an irq. The vCPU specific data is passed from
464 * outside, such as KVM. One example code path is as below:
465 * KVM -> IOMMU -> irq_set_vcpu_affinity().
467 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
470 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
471 struct irq_data *data;
472 struct irq_chip *chip;
478 data = irq_desc_get_irq_data(desc);
480 chip = irq_data_get_irq_chip(data);
481 if (chip && chip->irq_set_vcpu_affinity)
483 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
484 data = data->parent_data;
491 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
492 irq_put_desc_unlock(desc, flags);
496 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
498 void __disable_irq(struct irq_desc *desc)
504 static int __disable_irq_nosync(unsigned int irq)
507 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
512 irq_put_desc_busunlock(desc, flags);
517 * disable_irq_nosync - disable an irq without waiting
518 * @irq: Interrupt to disable
520 * Disable the selected interrupt line. Disables and Enables are
522 * Unlike disable_irq(), this function does not ensure existing
523 * instances of the IRQ handler have completed before returning.
525 * This function may be called from IRQ context.
527 void disable_irq_nosync(unsigned int irq)
529 __disable_irq_nosync(irq);
531 EXPORT_SYMBOL(disable_irq_nosync);
534 * disable_irq - disable an irq and wait for completion
535 * @irq: Interrupt to disable
537 * Disable the selected interrupt line. Enables and Disables are
539 * This function waits for any pending IRQ handlers for this interrupt
540 * to complete before returning. If you use this function while
541 * holding a resource the IRQ handler may need you will deadlock.
543 * This function may be called - with care - from IRQ context.
545 void disable_irq(unsigned int irq)
547 if (!__disable_irq_nosync(irq))
548 synchronize_irq(irq);
550 EXPORT_SYMBOL(disable_irq);
553 * disable_hardirq - disables an irq and waits for hardirq completion
554 * @irq: Interrupt to disable
556 * Disable the selected interrupt line. Enables and Disables are
558 * This function waits for any pending hard IRQ handlers for this
559 * interrupt to complete before returning. If you use this function while
560 * holding a resource the hard IRQ handler may need you will deadlock.
562 * When used to optimistically disable an interrupt from atomic context
563 * the return value must be checked.
565 * Returns: false if a threaded handler is active.
567 * This function may be called - with care - from IRQ context.
569 bool disable_hardirq(unsigned int irq)
571 if (!__disable_irq_nosync(irq))
572 return synchronize_hardirq(irq);
576 EXPORT_SYMBOL_GPL(disable_hardirq);
579 * disable_nmi_nosync - disable an nmi without waiting
580 * @irq: Interrupt to disable
582 * Disable the selected interrupt line. Disables and enables are
584 * The interrupt to disable must have been requested through request_nmi.
585 * Unlike disable_nmi(), this function does not ensure existing
586 * instances of the IRQ handler have completed before returning.
588 void disable_nmi_nosync(unsigned int irq)
590 disable_irq_nosync(irq);
593 void __enable_irq(struct irq_desc *desc)
595 switch (desc->depth) {
598 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
599 irq_desc_get_irq(desc));
602 if (desc->istate & IRQS_SUSPENDED)
604 /* Prevent probing on this irq: */
605 irq_settings_set_noprobe(desc);
607 * Call irq_startup() not irq_enable() here because the
608 * interrupt might be marked NOAUTOEN. So irq_startup()
609 * needs to be invoked when it gets enabled the first
610 * time. If it was already started up, then irq_startup()
611 * will invoke irq_enable() under the hood.
613 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
622 * enable_irq - enable handling of an irq
623 * @irq: Interrupt to enable
625 * Undoes the effect of one call to disable_irq(). If this
626 * matches the last disable, processing of interrupts on this
627 * IRQ line is re-enabled.
629 * This function may be called from IRQ context only when
630 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
632 void enable_irq(unsigned int irq)
635 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
639 if (WARN(!desc->irq_data.chip,
640 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
645 irq_put_desc_busunlock(desc, flags);
647 EXPORT_SYMBOL(enable_irq);
650 * enable_nmi - enable handling of an nmi
651 * @irq: Interrupt to enable
653 * The interrupt to enable must have been requested through request_nmi.
654 * Undoes the effect of one call to disable_nmi(). If this
655 * matches the last disable, processing of interrupts on this
656 * IRQ line is re-enabled.
658 void enable_nmi(unsigned int irq)
663 static int set_irq_wake_real(unsigned int irq, unsigned int on)
665 struct irq_desc *desc = irq_to_desc(irq);
668 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
671 if (desc->irq_data.chip->irq_set_wake)
672 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
678 * irq_set_irq_wake - control irq power management wakeup
679 * @irq: interrupt to control
680 * @on: enable/disable power management wakeup
682 * Enable/disable power management wakeup mode, which is
683 * disabled by default. Enables and disables must match,
684 * just as they match for non-wakeup mode support.
686 * Wakeup mode lets this IRQ wake the system from sleep
687 * states like "suspend to RAM".
689 int irq_set_irq_wake(unsigned int irq, unsigned int on)
692 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
698 /* Don't use NMIs as wake up interrupts please */
699 if (desc->istate & IRQS_NMI) {
704 /* wakeup-capable irqs can be shared between drivers that
705 * don't need to have the same sleep mode behaviors.
708 if (desc->wake_depth++ == 0) {
709 ret = set_irq_wake_real(irq, on);
711 desc->wake_depth = 0;
713 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
716 if (desc->wake_depth == 0) {
717 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
718 } else if (--desc->wake_depth == 0) {
719 ret = set_irq_wake_real(irq, on);
721 desc->wake_depth = 1;
723 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
728 irq_put_desc_busunlock(desc, flags);
731 EXPORT_SYMBOL(irq_set_irq_wake);
734 * Internal function that tells the architecture code whether a
735 * particular irq has been exclusively allocated or is available
738 int can_request_irq(unsigned int irq, unsigned long irqflags)
741 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
747 if (irq_settings_can_request(desc)) {
749 irqflags & desc->action->flags & IRQF_SHARED)
752 irq_put_desc_unlock(desc, flags);
756 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
758 struct irq_chip *chip = desc->irq_data.chip;
761 if (!chip || !chip->irq_set_type) {
763 * IRQF_TRIGGER_* but the PIC does not support multiple
766 pr_debug("No set_type function for IRQ %d (%s)\n",
767 irq_desc_get_irq(desc),
768 chip ? (chip->name ? : "unknown") : "unknown");
772 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
773 if (!irqd_irq_masked(&desc->irq_data))
775 if (!irqd_irq_disabled(&desc->irq_data))
779 /* Mask all flags except trigger mode */
780 flags &= IRQ_TYPE_SENSE_MASK;
781 ret = chip->irq_set_type(&desc->irq_data, flags);
784 case IRQ_SET_MASK_OK:
785 case IRQ_SET_MASK_OK_DONE:
786 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
787 irqd_set(&desc->irq_data, flags);
790 case IRQ_SET_MASK_OK_NOCOPY:
791 flags = irqd_get_trigger_type(&desc->irq_data);
792 irq_settings_set_trigger_mask(desc, flags);
793 irqd_clear(&desc->irq_data, IRQD_LEVEL);
794 irq_settings_clr_level(desc);
795 if (flags & IRQ_TYPE_LEVEL_MASK) {
796 irq_settings_set_level(desc);
797 irqd_set(&desc->irq_data, IRQD_LEVEL);
803 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
804 flags, irq_desc_get_irq(desc), chip->irq_set_type);
811 #ifdef CONFIG_HARDIRQS_SW_RESEND
812 int irq_set_parent(int irq, int parent_irq)
815 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
820 desc->parent_irq = parent_irq;
822 irq_put_desc_unlock(desc, flags);
825 EXPORT_SYMBOL_GPL(irq_set_parent);
829 * Default primary interrupt handler for threaded interrupts. Is
830 * assigned as primary handler when request_threaded_irq is called
831 * with handler == NULL. Useful for oneshot interrupts.
833 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
835 return IRQ_WAKE_THREAD;
839 * Primary handler for nested threaded interrupts. Should never be
842 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
844 WARN(1, "Primary handler called for nested irq %d\n", irq);
848 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
850 WARN(1, "Secondary action handler called for irq %d\n", irq);
854 static int irq_wait_for_interrupt(struct irqaction *action)
857 set_current_state(TASK_INTERRUPTIBLE);
859 if (kthread_should_stop()) {
860 /* may need to run one last time */
861 if (test_and_clear_bit(IRQTF_RUNTHREAD,
862 &action->thread_flags)) {
863 __set_current_state(TASK_RUNNING);
866 __set_current_state(TASK_RUNNING);
870 if (test_and_clear_bit(IRQTF_RUNTHREAD,
871 &action->thread_flags)) {
872 __set_current_state(TASK_RUNNING);
880 * Oneshot interrupts keep the irq line masked until the threaded
881 * handler finished. unmask if the interrupt has not been disabled and
884 static void irq_finalize_oneshot(struct irq_desc *desc,
885 struct irqaction *action)
887 if (!(desc->istate & IRQS_ONESHOT) ||
888 action->handler == irq_forced_secondary_handler)
892 raw_spin_lock_irq(&desc->lock);
895 * Implausible though it may be we need to protect us against
896 * the following scenario:
898 * The thread is faster done than the hard interrupt handler
899 * on the other CPU. If we unmask the irq line then the
900 * interrupt can come in again and masks the line, leaves due
901 * to IRQS_INPROGRESS and the irq line is masked forever.
903 * This also serializes the state of shared oneshot handlers
904 * versus "desc->threads_onehsot |= action->thread_mask;" in
905 * irq_wake_thread(). See the comment there which explains the
908 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
909 raw_spin_unlock_irq(&desc->lock);
910 chip_bus_sync_unlock(desc);
916 * Now check again, whether the thread should run. Otherwise
917 * we would clear the threads_oneshot bit of this thread which
920 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
923 desc->threads_oneshot &= ~action->thread_mask;
925 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
926 irqd_irq_masked(&desc->irq_data))
927 unmask_threaded_irq(desc);
930 raw_spin_unlock_irq(&desc->lock);
931 chip_bus_sync_unlock(desc);
936 * Check whether we need to change the affinity of the interrupt thread.
939 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
944 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
948 * In case we are out of memory we set IRQTF_AFFINITY again and
949 * try again next time
951 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
952 set_bit(IRQTF_AFFINITY, &action->thread_flags);
956 raw_spin_lock_irq(&desc->lock);
958 * This code is triggered unconditionally. Check the affinity
959 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
961 if (cpumask_available(desc->irq_common_data.affinity)) {
962 const struct cpumask *m;
964 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
965 cpumask_copy(mask, m);
969 raw_spin_unlock_irq(&desc->lock);
972 set_cpus_allowed_ptr(current, mask);
973 free_cpumask_var(mask);
977 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
981 * Interrupts which are not explicitly requested as threaded
982 * interrupts rely on the implicit bh/preempt disable of the hard irq
983 * context. So we need to disable bh here to avoid deadlocks and other
987 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
992 ret = action->thread_fn(action->irq, action->dev_id);
993 if (ret == IRQ_HANDLED)
994 atomic_inc(&desc->threads_handled);
996 irq_finalize_oneshot(desc, action);
1002 * Interrupts explicitly requested as threaded interrupts want to be
1003 * preemtible - many of them need to sleep and wait for slow busses to
1006 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1007 struct irqaction *action)
1011 ret = action->thread_fn(action->irq, action->dev_id);
1012 if (ret == IRQ_HANDLED)
1013 atomic_inc(&desc->threads_handled);
1015 irq_finalize_oneshot(desc, action);
1019 static void wake_threads_waitq(struct irq_desc *desc)
1021 if (atomic_dec_and_test(&desc->threads_active))
1022 wake_up(&desc->wait_for_threads);
1025 static void irq_thread_dtor(struct callback_head *unused)
1027 struct task_struct *tsk = current;
1028 struct irq_desc *desc;
1029 struct irqaction *action;
1031 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1034 action = kthread_data(tsk);
1036 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1037 tsk->comm, tsk->pid, action->irq);
1040 desc = irq_to_desc(action->irq);
1042 * If IRQTF_RUNTHREAD is set, we need to decrement
1043 * desc->threads_active and wake possible waiters.
1045 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1046 wake_threads_waitq(desc);
1048 /* Prevent a stale desc->threads_oneshot */
1049 irq_finalize_oneshot(desc, action);
1052 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1054 struct irqaction *secondary = action->secondary;
1056 if (WARN_ON_ONCE(!secondary))
1059 raw_spin_lock_irq(&desc->lock);
1060 __irq_wake_thread(desc, secondary);
1061 raw_spin_unlock_irq(&desc->lock);
1065 * Interrupt handler thread
1067 static int irq_thread(void *data)
1069 struct callback_head on_exit_work;
1070 struct irqaction *action = data;
1071 struct irq_desc *desc = irq_to_desc(action->irq);
1072 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1073 struct irqaction *action);
1075 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1076 &action->thread_flags))
1077 handler_fn = irq_forced_thread_fn;
1079 handler_fn = irq_thread_fn;
1081 init_task_work(&on_exit_work, irq_thread_dtor);
1082 task_work_add(current, &on_exit_work, false);
1084 irq_thread_check_affinity(desc, action);
1086 while (!irq_wait_for_interrupt(action)) {
1087 irqreturn_t action_ret;
1089 irq_thread_check_affinity(desc, action);
1091 action_ret = handler_fn(desc, action);
1092 if (action_ret == IRQ_WAKE_THREAD)
1093 irq_wake_secondary(desc, action);
1095 wake_threads_waitq(desc);
1099 * This is the regular exit path. __free_irq() is stopping the
1100 * thread via kthread_stop() after calling
1101 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1102 * oneshot mask bit can be set.
1104 task_work_cancel(current, irq_thread_dtor);
1109 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1110 * @irq: Interrupt line
1111 * @dev_id: Device identity for which the thread should be woken
1114 void irq_wake_thread(unsigned int irq, void *dev_id)
1116 struct irq_desc *desc = irq_to_desc(irq);
1117 struct irqaction *action;
1118 unsigned long flags;
1120 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1123 raw_spin_lock_irqsave(&desc->lock, flags);
1124 for_each_action_of_desc(desc, action) {
1125 if (action->dev_id == dev_id) {
1127 __irq_wake_thread(desc, action);
1131 raw_spin_unlock_irqrestore(&desc->lock, flags);
1133 EXPORT_SYMBOL_GPL(irq_wake_thread);
1135 static int irq_setup_forced_threading(struct irqaction *new)
1137 if (!force_irqthreads)
1139 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1143 * No further action required for interrupts which are requested as
1144 * threaded interrupts already
1146 if (new->handler == irq_default_primary_handler)
1149 new->flags |= IRQF_ONESHOT;
1152 * Handle the case where we have a real primary handler and a
1153 * thread handler. We force thread them as well by creating a
1156 if (new->handler && new->thread_fn) {
1157 /* Allocate the secondary action */
1158 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1159 if (!new->secondary)
1161 new->secondary->handler = irq_forced_secondary_handler;
1162 new->secondary->thread_fn = new->thread_fn;
1163 new->secondary->dev_id = new->dev_id;
1164 new->secondary->irq = new->irq;
1165 new->secondary->name = new->name;
1167 /* Deal with the primary handler */
1168 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1169 new->thread_fn = new->handler;
1170 new->handler = irq_default_primary_handler;
1174 static int irq_request_resources(struct irq_desc *desc)
1176 struct irq_data *d = &desc->irq_data;
1177 struct irq_chip *c = d->chip;
1179 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1182 static void irq_release_resources(struct irq_desc *desc)
1184 struct irq_data *d = &desc->irq_data;
1185 struct irq_chip *c = d->chip;
1187 if (c->irq_release_resources)
1188 c->irq_release_resources(d);
1191 static bool irq_supports_nmi(struct irq_desc *desc)
1193 struct irq_data *d = irq_desc_get_irq_data(desc);
1195 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1196 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1200 /* Don't support NMIs for chips behind a slow bus */
1201 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1204 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1207 static int irq_nmi_setup(struct irq_desc *desc)
1209 struct irq_data *d = irq_desc_get_irq_data(desc);
1210 struct irq_chip *c = d->chip;
1212 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1215 static void irq_nmi_teardown(struct irq_desc *desc)
1217 struct irq_data *d = irq_desc_get_irq_data(desc);
1218 struct irq_chip *c = d->chip;
1220 if (c->irq_nmi_teardown)
1221 c->irq_nmi_teardown(d);
1225 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1227 struct task_struct *t;
1228 struct sched_param param = {
1229 .sched_priority = MAX_USER_RT_PRIO/2,
1233 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1236 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1238 param.sched_priority -= 1;
1244 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1247 * We keep the reference to the task struct even if
1248 * the thread dies to avoid that the interrupt code
1249 * references an already freed task_struct.
1251 new->thread = get_task_struct(t);
1253 * Tell the thread to set its affinity. This is
1254 * important for shared interrupt handlers as we do
1255 * not invoke setup_affinity() for the secondary
1256 * handlers as everything is already set up. Even for
1257 * interrupts marked with IRQF_NO_BALANCE this is
1258 * correct as we want the thread to move to the cpu(s)
1259 * on which the requesting code placed the interrupt.
1261 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1266 * Internal function to register an irqaction - typically used to
1267 * allocate special interrupts that are part of the architecture.
1271 * desc->request_mutex Provides serialization against a concurrent free_irq()
1272 * chip_bus_lock Provides serialization for slow bus operations
1273 * desc->lock Provides serialization against hard interrupts
1275 * chip_bus_lock and desc->lock are sufficient for all other management and
1276 * interrupt related functions. desc->request_mutex solely serializes
1277 * request/free_irq().
1280 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1282 struct irqaction *old, **old_ptr;
1283 unsigned long flags, thread_mask = 0;
1284 int ret, nested, shared = 0;
1289 if (desc->irq_data.chip == &no_irq_chip)
1291 if (!try_module_get(desc->owner))
1297 * If the trigger type is not specified by the caller,
1298 * then use the default for this interrupt.
1300 if (!(new->flags & IRQF_TRIGGER_MASK))
1301 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1304 * Check whether the interrupt nests into another interrupt
1307 nested = irq_settings_is_nested_thread(desc);
1309 if (!new->thread_fn) {
1314 * Replace the primary handler which was provided from
1315 * the driver for non nested interrupt handling by the
1316 * dummy function which warns when called.
1318 new->handler = irq_nested_primary_handler;
1320 if (irq_settings_can_thread(desc)) {
1321 ret = irq_setup_forced_threading(new);
1328 * Create a handler thread when a thread function is supplied
1329 * and the interrupt does not nest into another interrupt
1332 if (new->thread_fn && !nested) {
1333 ret = setup_irq_thread(new, irq, false);
1336 if (new->secondary) {
1337 ret = setup_irq_thread(new->secondary, irq, true);
1344 * Drivers are often written to work w/o knowledge about the
1345 * underlying irq chip implementation, so a request for a
1346 * threaded irq without a primary hard irq context handler
1347 * requires the ONESHOT flag to be set. Some irq chips like
1348 * MSI based interrupts are per se one shot safe. Check the
1349 * chip flags, so we can avoid the unmask dance at the end of
1350 * the threaded handler for those.
1352 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1353 new->flags &= ~IRQF_ONESHOT;
1356 * Protects against a concurrent __free_irq() call which might wait
1357 * for synchronize_hardirq() to complete without holding the optional
1358 * chip bus lock and desc->lock. Also protects against handing out
1359 * a recycled oneshot thread_mask bit while it's still in use by
1360 * its previous owner.
1362 mutex_lock(&desc->request_mutex);
1365 * Acquire bus lock as the irq_request_resources() callback below
1366 * might rely on the serialization or the magic power management
1367 * functions which are abusing the irq_bus_lock() callback,
1369 chip_bus_lock(desc);
1371 /* First installed action requests resources. */
1372 if (!desc->action) {
1373 ret = irq_request_resources(desc);
1375 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1376 new->name, irq, desc->irq_data.chip->name);
1377 goto out_bus_unlock;
1382 * The following block of code has to be executed atomically
1383 * protected against a concurrent interrupt and any of the other
1384 * management calls which are not serialized via
1385 * desc->request_mutex or the optional bus lock.
1387 raw_spin_lock_irqsave(&desc->lock, flags);
1388 old_ptr = &desc->action;
1392 * Can't share interrupts unless both agree to and are
1393 * the same type (level, edge, polarity). So both flag
1394 * fields must have IRQF_SHARED set and the bits which
1395 * set the trigger type must match. Also all must
1397 * Interrupt lines used for NMIs cannot be shared.
1399 unsigned int oldtype;
1401 if (desc->istate & IRQS_NMI) {
1402 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1403 new->name, irq, desc->irq_data.chip->name);
1409 * If nobody did set the configuration before, inherit
1410 * the one provided by the requester.
1412 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1413 oldtype = irqd_get_trigger_type(&desc->irq_data);
1415 oldtype = new->flags & IRQF_TRIGGER_MASK;
1416 irqd_set_trigger_type(&desc->irq_data, oldtype);
1419 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1420 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1421 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1424 /* All handlers must agree on per-cpuness */
1425 if ((old->flags & IRQF_PERCPU) !=
1426 (new->flags & IRQF_PERCPU))
1429 /* add new interrupt at end of irq queue */
1432 * Or all existing action->thread_mask bits,
1433 * so we can find the next zero bit for this
1436 thread_mask |= old->thread_mask;
1437 old_ptr = &old->next;
1444 * Setup the thread mask for this irqaction for ONESHOT. For
1445 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1446 * conditional in irq_wake_thread().
1448 if (new->flags & IRQF_ONESHOT) {
1450 * Unlikely to have 32 resp 64 irqs sharing one line,
1453 if (thread_mask == ~0UL) {
1458 * The thread_mask for the action is or'ed to
1459 * desc->thread_active to indicate that the
1460 * IRQF_ONESHOT thread handler has been woken, but not
1461 * yet finished. The bit is cleared when a thread
1462 * completes. When all threads of a shared interrupt
1463 * line have completed desc->threads_active becomes
1464 * zero and the interrupt line is unmasked. See
1465 * handle.c:irq_wake_thread() for further information.
1467 * If no thread is woken by primary (hard irq context)
1468 * interrupt handlers, then desc->threads_active is
1469 * also checked for zero to unmask the irq line in the
1470 * affected hard irq flow handlers
1471 * (handle_[fasteoi|level]_irq).
1473 * The new action gets the first zero bit of
1474 * thread_mask assigned. See the loop above which or's
1475 * all existing action->thread_mask bits.
1477 new->thread_mask = 1UL << ffz(thread_mask);
1479 } else if (new->handler == irq_default_primary_handler &&
1480 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1482 * The interrupt was requested with handler = NULL, so
1483 * we use the default primary handler for it. But it
1484 * does not have the oneshot flag set. In combination
1485 * with level interrupts this is deadly, because the
1486 * default primary handler just wakes the thread, then
1487 * the irq lines is reenabled, but the device still
1488 * has the level irq asserted. Rinse and repeat....
1490 * While this works for edge type interrupts, we play
1491 * it safe and reject unconditionally because we can't
1492 * say for sure which type this interrupt really
1493 * has. The type flags are unreliable as the
1494 * underlying chip implementation can override them.
1496 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1503 init_waitqueue_head(&desc->wait_for_threads);
1505 /* Setup the type (level, edge polarity) if configured: */
1506 if (new->flags & IRQF_TRIGGER_MASK) {
1507 ret = __irq_set_trigger(desc,
1508 new->flags & IRQF_TRIGGER_MASK);
1515 * Activate the interrupt. That activation must happen
1516 * independently of IRQ_NOAUTOEN. request_irq() can fail
1517 * and the callers are supposed to handle
1518 * that. enable_irq() of an interrupt requested with
1519 * IRQ_NOAUTOEN is not supposed to fail. The activation
1520 * keeps it in shutdown mode, it merily associates
1521 * resources if necessary and if that's not possible it
1522 * fails. Interrupts which are in managed shutdown mode
1523 * will simply ignore that activation request.
1525 ret = irq_activate(desc);
1529 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1530 IRQS_ONESHOT | IRQS_WAITING);
1531 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1533 if (new->flags & IRQF_PERCPU) {
1534 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1535 irq_settings_set_per_cpu(desc);
1538 if (new->flags & IRQF_ONESHOT)
1539 desc->istate |= IRQS_ONESHOT;
1541 /* Exclude IRQ from balancing if requested */
1542 if (new->flags & IRQF_NOBALANCING) {
1543 irq_settings_set_no_balancing(desc);
1544 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1547 if (irq_settings_can_autoenable(desc)) {
1548 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1551 * Shared interrupts do not go well with disabling
1552 * auto enable. The sharing interrupt might request
1553 * it while it's still disabled and then wait for
1554 * interrupts forever.
1556 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1557 /* Undo nested disables: */
1561 } else if (new->flags & IRQF_TRIGGER_MASK) {
1562 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1563 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1566 /* hope the handler works with current trigger mode */
1567 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1573 irq_pm_install_action(desc, new);
1575 /* Reset broken irq detection when installing new handler */
1576 desc->irq_count = 0;
1577 desc->irqs_unhandled = 0;
1580 * Check whether we disabled the irq via the spurious handler
1581 * before. Reenable it and give it another chance.
1583 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1584 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1588 raw_spin_unlock_irqrestore(&desc->lock, flags);
1589 chip_bus_sync_unlock(desc);
1590 mutex_unlock(&desc->request_mutex);
1592 irq_setup_timings(desc, new);
1595 * Strictly no need to wake it up, but hung_task complains
1596 * when no hard interrupt wakes the thread up.
1599 wake_up_process(new->thread);
1601 wake_up_process(new->secondary->thread);
1603 register_irq_proc(irq, desc);
1605 register_handler_proc(irq, new);
1609 if (!(new->flags & IRQF_PROBE_SHARED)) {
1610 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1611 irq, new->flags, new->name, old->flags, old->name);
1612 #ifdef CONFIG_DEBUG_SHIRQ
1619 raw_spin_unlock_irqrestore(&desc->lock, flags);
1622 irq_release_resources(desc);
1624 chip_bus_sync_unlock(desc);
1625 mutex_unlock(&desc->request_mutex);
1629 struct task_struct *t = new->thread;
1635 if (new->secondary && new->secondary->thread) {
1636 struct task_struct *t = new->secondary->thread;
1638 new->secondary->thread = NULL;
1643 module_put(desc->owner);
1648 * setup_irq - setup an interrupt
1649 * @irq: Interrupt line to setup
1650 * @act: irqaction for the interrupt
1652 * Used to statically setup interrupts in the early boot process.
1654 int setup_irq(unsigned int irq, struct irqaction *act)
1657 struct irq_desc *desc = irq_to_desc(irq);
1659 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1662 retval = irq_chip_pm_get(&desc->irq_data);
1666 retval = __setup_irq(irq, desc, act);
1669 irq_chip_pm_put(&desc->irq_data);
1673 EXPORT_SYMBOL_GPL(setup_irq);
1676 * Internal function to unregister an irqaction - used to free
1677 * regular and special interrupts that are part of the architecture.
1679 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1681 unsigned irq = desc->irq_data.irq;
1682 struct irqaction *action, **action_ptr;
1683 unsigned long flags;
1685 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1687 mutex_lock(&desc->request_mutex);
1688 chip_bus_lock(desc);
1689 raw_spin_lock_irqsave(&desc->lock, flags);
1692 * There can be multiple actions per IRQ descriptor, find the right
1693 * one based on the dev_id:
1695 action_ptr = &desc->action;
1697 action = *action_ptr;
1700 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1701 raw_spin_unlock_irqrestore(&desc->lock, flags);
1702 chip_bus_sync_unlock(desc);
1703 mutex_unlock(&desc->request_mutex);
1707 if (action->dev_id == dev_id)
1709 action_ptr = &action->next;
1712 /* Found it - now remove it from the list of entries: */
1713 *action_ptr = action->next;
1715 irq_pm_remove_action(desc, action);
1717 /* If this was the last handler, shut down the IRQ line: */
1718 if (!desc->action) {
1719 irq_settings_clr_disable_unlazy(desc);
1720 /* Only shutdown. Deactivate after synchronize_hardirq() */
1725 /* make sure affinity_hint is cleaned up */
1726 if (WARN_ON_ONCE(desc->affinity_hint))
1727 desc->affinity_hint = NULL;
1730 raw_spin_unlock_irqrestore(&desc->lock, flags);
1732 * Drop bus_lock here so the changes which were done in the chip
1733 * callbacks above are synced out to the irq chips which hang
1734 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1736 * Aside of that the bus_lock can also be taken from the threaded
1737 * handler in irq_finalize_oneshot() which results in a deadlock
1738 * because kthread_stop() would wait forever for the thread to
1739 * complete, which is blocked on the bus lock.
1741 * The still held desc->request_mutex() protects against a
1742 * concurrent request_irq() of this irq so the release of resources
1743 * and timing data is properly serialized.
1745 chip_bus_sync_unlock(desc);
1747 unregister_handler_proc(irq, action);
1750 * Make sure it's not being used on another CPU and if the chip
1751 * supports it also make sure that there is no (not yet serviced)
1752 * interrupt in flight at the hardware level.
1754 __synchronize_hardirq(desc, true);
1756 #ifdef CONFIG_DEBUG_SHIRQ
1758 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1759 * event to happen even now it's being freed, so let's make sure that
1760 * is so by doing an extra call to the handler ....
1762 * ( We do this after actually deregistering it, to make sure that a
1763 * 'real' IRQ doesn't run in parallel with our fake. )
1765 if (action->flags & IRQF_SHARED) {
1766 local_irq_save(flags);
1767 action->handler(irq, dev_id);
1768 local_irq_restore(flags);
1773 * The action has already been removed above, but the thread writes
1774 * its oneshot mask bit when it completes. Though request_mutex is
1775 * held across this which prevents __setup_irq() from handing out
1776 * the same bit to a newly requested action.
1778 if (action->thread) {
1779 kthread_stop(action->thread);
1780 put_task_struct(action->thread);
1781 if (action->secondary && action->secondary->thread) {
1782 kthread_stop(action->secondary->thread);
1783 put_task_struct(action->secondary->thread);
1787 /* Last action releases resources */
1788 if (!desc->action) {
1790 * Reaquire bus lock as irq_release_resources() might
1791 * require it to deallocate resources over the slow bus.
1793 chip_bus_lock(desc);
1795 * There is no interrupt on the fly anymore. Deactivate it
1798 raw_spin_lock_irqsave(&desc->lock, flags);
1799 irq_domain_deactivate_irq(&desc->irq_data);
1800 raw_spin_unlock_irqrestore(&desc->lock, flags);
1802 irq_release_resources(desc);
1803 chip_bus_sync_unlock(desc);
1804 irq_remove_timings(desc);
1807 mutex_unlock(&desc->request_mutex);
1809 irq_chip_pm_put(&desc->irq_data);
1810 module_put(desc->owner);
1811 kfree(action->secondary);
1816 * remove_irq - free an interrupt
1817 * @irq: Interrupt line to free
1818 * @act: irqaction for the interrupt
1820 * Used to remove interrupts statically setup by the early boot process.
1822 void remove_irq(unsigned int irq, struct irqaction *act)
1824 struct irq_desc *desc = irq_to_desc(irq);
1826 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1827 __free_irq(desc, act->dev_id);
1829 EXPORT_SYMBOL_GPL(remove_irq);
1832 * free_irq - free an interrupt allocated with request_irq
1833 * @irq: Interrupt line to free
1834 * @dev_id: Device identity to free
1836 * Remove an interrupt handler. The handler is removed and if the
1837 * interrupt line is no longer in use by any driver it is disabled.
1838 * On a shared IRQ the caller must ensure the interrupt is disabled
1839 * on the card it drives before calling this function. The function
1840 * does not return until any executing interrupts for this IRQ
1843 * This function must not be called from interrupt context.
1845 * Returns the devname argument passed to request_irq.
1847 const void *free_irq(unsigned int irq, void *dev_id)
1849 struct irq_desc *desc = irq_to_desc(irq);
1850 struct irqaction *action;
1851 const char *devname;
1853 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1857 if (WARN_ON(desc->affinity_notify))
1858 desc->affinity_notify = NULL;
1861 action = __free_irq(desc, dev_id);
1866 devname = action->name;
1870 EXPORT_SYMBOL(free_irq);
1872 /* This function must be called with desc->lock held */
1873 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1875 const char *devname = NULL;
1877 desc->istate &= ~IRQS_NMI;
1879 if (!WARN_ON(desc->action == NULL)) {
1880 irq_pm_remove_action(desc, desc->action);
1881 devname = desc->action->name;
1882 unregister_handler_proc(irq, desc->action);
1884 kfree(desc->action);
1885 desc->action = NULL;
1888 irq_settings_clr_disable_unlazy(desc);
1889 irq_shutdown_and_deactivate(desc);
1891 irq_release_resources(desc);
1893 irq_chip_pm_put(&desc->irq_data);
1894 module_put(desc->owner);
1899 const void *free_nmi(unsigned int irq, void *dev_id)
1901 struct irq_desc *desc = irq_to_desc(irq);
1902 unsigned long flags;
1903 const void *devname;
1905 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1908 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1911 /* NMI still enabled */
1912 if (WARN_ON(desc->depth == 0))
1913 disable_nmi_nosync(irq);
1915 raw_spin_lock_irqsave(&desc->lock, flags);
1917 irq_nmi_teardown(desc);
1918 devname = __cleanup_nmi(irq, desc);
1920 raw_spin_unlock_irqrestore(&desc->lock, flags);
1926 * request_threaded_irq - allocate an interrupt line
1927 * @irq: Interrupt line to allocate
1928 * @handler: Function to be called when the IRQ occurs.
1929 * Primary handler for threaded interrupts
1930 * If NULL and thread_fn != NULL the default
1931 * primary handler is installed
1932 * @thread_fn: Function called from the irq handler thread
1933 * If NULL, no irq thread is created
1934 * @irqflags: Interrupt type flags
1935 * @devname: An ascii name for the claiming device
1936 * @dev_id: A cookie passed back to the handler function
1938 * This call allocates interrupt resources and enables the
1939 * interrupt line and IRQ handling. From the point this
1940 * call is made your handler function may be invoked. Since
1941 * your handler function must clear any interrupt the board
1942 * raises, you must take care both to initialise your hardware
1943 * and to set up the interrupt handler in the right order.
1945 * If you want to set up a threaded irq handler for your device
1946 * then you need to supply @handler and @thread_fn. @handler is
1947 * still called in hard interrupt context and has to check
1948 * whether the interrupt originates from the device. If yes it
1949 * needs to disable the interrupt on the device and return
1950 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1951 * @thread_fn. This split handler design is necessary to support
1952 * shared interrupts.
1954 * Dev_id must be globally unique. Normally the address of the
1955 * device data structure is used as the cookie. Since the handler
1956 * receives this value it makes sense to use it.
1958 * If your interrupt is shared you must pass a non NULL dev_id
1959 * as this is required when freeing the interrupt.
1963 * IRQF_SHARED Interrupt is shared
1964 * IRQF_TRIGGER_* Specify active edge(s) or level
1967 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1968 irq_handler_t thread_fn, unsigned long irqflags,
1969 const char *devname, void *dev_id)
1971 struct irqaction *action;
1972 struct irq_desc *desc;
1975 if (irq == IRQ_NOTCONNECTED)
1979 * Sanity-check: shared interrupts must pass in a real dev-ID,
1980 * otherwise we'll have trouble later trying to figure out
1981 * which interrupt is which (messes up the interrupt freeing
1984 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1985 * it cannot be set along with IRQF_NO_SUSPEND.
1987 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1988 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1989 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1992 desc = irq_to_desc(irq);
1996 if (!irq_settings_can_request(desc) ||
1997 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2003 handler = irq_default_primary_handler;
2006 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2010 action->handler = handler;
2011 action->thread_fn = thread_fn;
2012 action->flags = irqflags;
2013 action->name = devname;
2014 action->dev_id = dev_id;
2016 retval = irq_chip_pm_get(&desc->irq_data);
2022 retval = __setup_irq(irq, desc, action);
2025 irq_chip_pm_put(&desc->irq_data);
2026 kfree(action->secondary);
2030 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2031 if (!retval && (irqflags & IRQF_SHARED)) {
2033 * It's a shared IRQ -- the driver ought to be prepared for it
2034 * to happen immediately, so let's make sure....
2035 * We disable the irq to make sure that a 'real' IRQ doesn't
2036 * run in parallel with our fake.
2038 unsigned long flags;
2041 local_irq_save(flags);
2043 handler(irq, dev_id);
2045 local_irq_restore(flags);
2051 EXPORT_SYMBOL(request_threaded_irq);
2054 * request_any_context_irq - allocate an interrupt line
2055 * @irq: Interrupt line to allocate
2056 * @handler: Function to be called when the IRQ occurs.
2057 * Threaded handler for threaded interrupts.
2058 * @flags: Interrupt type flags
2059 * @name: An ascii name for the claiming device
2060 * @dev_id: A cookie passed back to the handler function
2062 * This call allocates interrupt resources and enables the
2063 * interrupt line and IRQ handling. It selects either a
2064 * hardirq or threaded handling method depending on the
2067 * On failure, it returns a negative value. On success,
2068 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2070 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2071 unsigned long flags, const char *name, void *dev_id)
2073 struct irq_desc *desc;
2076 if (irq == IRQ_NOTCONNECTED)
2079 desc = irq_to_desc(irq);
2083 if (irq_settings_is_nested_thread(desc)) {
2084 ret = request_threaded_irq(irq, NULL, handler,
2085 flags, name, dev_id);
2086 return !ret ? IRQC_IS_NESTED : ret;
2089 ret = request_irq(irq, handler, flags, name, dev_id);
2090 return !ret ? IRQC_IS_HARDIRQ : ret;
2092 EXPORT_SYMBOL_GPL(request_any_context_irq);
2095 * request_nmi - allocate an interrupt line for NMI delivery
2096 * @irq: Interrupt line to allocate
2097 * @handler: Function to be called when the IRQ occurs.
2098 * Threaded handler for threaded interrupts.
2099 * @irqflags: Interrupt type flags
2100 * @name: An ascii name for the claiming device
2101 * @dev_id: A cookie passed back to the handler function
2103 * This call allocates interrupt resources and enables the
2104 * interrupt line and IRQ handling. It sets up the IRQ line
2105 * to be handled as an NMI.
2107 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2108 * cannot be threaded.
2110 * Interrupt lines requested for NMI delivering must produce per cpu
2111 * interrupts and have auto enabling setting disabled.
2113 * Dev_id must be globally unique. Normally the address of the
2114 * device data structure is used as the cookie. Since the handler
2115 * receives this value it makes sense to use it.
2117 * If the interrupt line cannot be used to deliver NMIs, function
2118 * will fail and return a negative value.
2120 int request_nmi(unsigned int irq, irq_handler_t handler,
2121 unsigned long irqflags, const char *name, void *dev_id)
2123 struct irqaction *action;
2124 struct irq_desc *desc;
2125 unsigned long flags;
2128 if (irq == IRQ_NOTCONNECTED)
2131 /* NMI cannot be shared, used for Polling */
2132 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2135 if (!(irqflags & IRQF_PERCPU))
2141 desc = irq_to_desc(irq);
2143 if (!desc || irq_settings_can_autoenable(desc) ||
2144 !irq_settings_can_request(desc) ||
2145 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2146 !irq_supports_nmi(desc))
2149 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2153 action->handler = handler;
2154 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2155 action->name = name;
2156 action->dev_id = dev_id;
2158 retval = irq_chip_pm_get(&desc->irq_data);
2162 retval = __setup_irq(irq, desc, action);
2166 raw_spin_lock_irqsave(&desc->lock, flags);
2168 /* Setup NMI state */
2169 desc->istate |= IRQS_NMI;
2170 retval = irq_nmi_setup(desc);
2172 __cleanup_nmi(irq, desc);
2173 raw_spin_unlock_irqrestore(&desc->lock, flags);
2177 raw_spin_unlock_irqrestore(&desc->lock, flags);
2182 irq_chip_pm_put(&desc->irq_data);
2189 void enable_percpu_irq(unsigned int irq, unsigned int type)
2191 unsigned int cpu = smp_processor_id();
2192 unsigned long flags;
2193 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2199 * If the trigger type is not specified by the caller, then
2200 * use the default for this interrupt.
2202 type &= IRQ_TYPE_SENSE_MASK;
2203 if (type == IRQ_TYPE_NONE)
2204 type = irqd_get_trigger_type(&desc->irq_data);
2206 if (type != IRQ_TYPE_NONE) {
2209 ret = __irq_set_trigger(desc, type);
2212 WARN(1, "failed to set type for IRQ%d\n", irq);
2217 irq_percpu_enable(desc, cpu);
2219 irq_put_desc_unlock(desc, flags);
2221 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2223 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2225 enable_percpu_irq(irq, type);
2229 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2230 * @irq: Linux irq number to check for
2232 * Must be called from a non migratable context. Returns the enable
2233 * state of a per cpu interrupt on the current cpu.
2235 bool irq_percpu_is_enabled(unsigned int irq)
2237 unsigned int cpu = smp_processor_id();
2238 struct irq_desc *desc;
2239 unsigned long flags;
2242 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2246 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2247 irq_put_desc_unlock(desc, flags);
2251 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2253 void disable_percpu_irq(unsigned int irq)
2255 unsigned int cpu = smp_processor_id();
2256 unsigned long flags;
2257 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2262 irq_percpu_disable(desc, cpu);
2263 irq_put_desc_unlock(desc, flags);
2265 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2267 void disable_percpu_nmi(unsigned int irq)
2269 disable_percpu_irq(irq);
2273 * Internal function to unregister a percpu irqaction.
2275 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2277 struct irq_desc *desc = irq_to_desc(irq);
2278 struct irqaction *action;
2279 unsigned long flags;
2281 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2286 raw_spin_lock_irqsave(&desc->lock, flags);
2288 action = desc->action;
2289 if (!action || action->percpu_dev_id != dev_id) {
2290 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2294 if (!cpumask_empty(desc->percpu_enabled)) {
2295 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2296 irq, cpumask_first(desc->percpu_enabled));
2300 /* Found it - now remove it from the list of entries: */
2301 desc->action = NULL;
2303 desc->istate &= ~IRQS_NMI;
2305 raw_spin_unlock_irqrestore(&desc->lock, flags);
2307 unregister_handler_proc(irq, action);
2309 irq_chip_pm_put(&desc->irq_data);
2310 module_put(desc->owner);
2314 raw_spin_unlock_irqrestore(&desc->lock, flags);
2319 * remove_percpu_irq - free a per-cpu interrupt
2320 * @irq: Interrupt line to free
2321 * @act: irqaction for the interrupt
2323 * Used to remove interrupts statically setup by the early boot process.
2325 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2327 struct irq_desc *desc = irq_to_desc(irq);
2329 if (desc && irq_settings_is_per_cpu_devid(desc))
2330 __free_percpu_irq(irq, act->percpu_dev_id);
2334 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2335 * @irq: Interrupt line to free
2336 * @dev_id: Device identity to free
2338 * Remove a percpu interrupt handler. The handler is removed, but
2339 * the interrupt line is not disabled. This must be done on each
2340 * CPU before calling this function. The function does not return
2341 * until any executing interrupts for this IRQ have completed.
2343 * This function must not be called from interrupt context.
2345 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2347 struct irq_desc *desc = irq_to_desc(irq);
2349 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2352 chip_bus_lock(desc);
2353 kfree(__free_percpu_irq(irq, dev_id));
2354 chip_bus_sync_unlock(desc);
2356 EXPORT_SYMBOL_GPL(free_percpu_irq);
2358 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2360 struct irq_desc *desc = irq_to_desc(irq);
2362 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2365 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2368 kfree(__free_percpu_irq(irq, dev_id));
2372 * setup_percpu_irq - setup a per-cpu interrupt
2373 * @irq: Interrupt line to setup
2374 * @act: irqaction for the interrupt
2376 * Used to statically setup per-cpu interrupts in the early boot process.
2378 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2380 struct irq_desc *desc = irq_to_desc(irq);
2383 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2386 retval = irq_chip_pm_get(&desc->irq_data);
2390 retval = __setup_irq(irq, desc, act);
2393 irq_chip_pm_put(&desc->irq_data);
2399 * __request_percpu_irq - allocate a percpu interrupt line
2400 * @irq: Interrupt line to allocate
2401 * @handler: Function to be called when the IRQ occurs.
2402 * @flags: Interrupt type flags (IRQF_TIMER only)
2403 * @devname: An ascii name for the claiming device
2404 * @dev_id: A percpu cookie passed back to the handler function
2406 * This call allocates interrupt resources and enables the
2407 * interrupt on the local CPU. If the interrupt is supposed to be
2408 * enabled on other CPUs, it has to be done on each CPU using
2409 * enable_percpu_irq().
2411 * Dev_id must be globally unique. It is a per-cpu variable, and
2412 * the handler gets called with the interrupted CPU's instance of
2415 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2416 unsigned long flags, const char *devname,
2417 void __percpu *dev_id)
2419 struct irqaction *action;
2420 struct irq_desc *desc;
2426 desc = irq_to_desc(irq);
2427 if (!desc || !irq_settings_can_request(desc) ||
2428 !irq_settings_is_per_cpu_devid(desc))
2431 if (flags && flags != IRQF_TIMER)
2434 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2438 action->handler = handler;
2439 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2440 action->name = devname;
2441 action->percpu_dev_id = dev_id;
2443 retval = irq_chip_pm_get(&desc->irq_data);
2449 retval = __setup_irq(irq, desc, action);
2452 irq_chip_pm_put(&desc->irq_data);
2458 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2461 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2462 * @irq: Interrupt line to allocate
2463 * @handler: Function to be called when the IRQ occurs.
2464 * @name: An ascii name for the claiming device
2465 * @dev_id: A percpu cookie passed back to the handler function
2467 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2468 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2469 * being enabled on the same CPU by using enable_percpu_nmi().
2471 * Dev_id must be globally unique. It is a per-cpu variable, and
2472 * the handler gets called with the interrupted CPU's instance of
2475 * Interrupt lines requested for NMI delivering should have auto enabling
2478 * If the interrupt line cannot be used to deliver NMIs, function
2479 * will fail returning a negative value.
2481 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2482 const char *name, void __percpu *dev_id)
2484 struct irqaction *action;
2485 struct irq_desc *desc;
2486 unsigned long flags;
2492 desc = irq_to_desc(irq);
2494 if (!desc || !irq_settings_can_request(desc) ||
2495 !irq_settings_is_per_cpu_devid(desc) ||
2496 irq_settings_can_autoenable(desc) ||
2497 !irq_supports_nmi(desc))
2500 /* The line cannot already be NMI */
2501 if (desc->istate & IRQS_NMI)
2504 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2508 action->handler = handler;
2509 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2511 action->name = name;
2512 action->percpu_dev_id = dev_id;
2514 retval = irq_chip_pm_get(&desc->irq_data);
2518 retval = __setup_irq(irq, desc, action);
2522 raw_spin_lock_irqsave(&desc->lock, flags);
2523 desc->istate |= IRQS_NMI;
2524 raw_spin_unlock_irqrestore(&desc->lock, flags);
2529 irq_chip_pm_put(&desc->irq_data);
2537 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2538 * @irq: Interrupt line to prepare for NMI delivery
2540 * This call prepares an interrupt line to deliver NMI on the current CPU,
2541 * before that interrupt line gets enabled with enable_percpu_nmi().
2543 * As a CPU local operation, this should be called from non-preemptible
2546 * If the interrupt line cannot be used to deliver NMIs, function
2547 * will fail returning a negative value.
2549 int prepare_percpu_nmi(unsigned int irq)
2551 unsigned long flags;
2552 struct irq_desc *desc;
2555 WARN_ON(preemptible());
2557 desc = irq_get_desc_lock(irq, &flags,
2558 IRQ_GET_DESC_CHECK_PERCPU);
2562 if (WARN(!(desc->istate & IRQS_NMI),
2563 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2569 ret = irq_nmi_setup(desc);
2571 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2576 irq_put_desc_unlock(desc, flags);
2581 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2582 * @irq: Interrupt line from which CPU local NMI configuration should be
2585 * This call undoes the setup done by prepare_percpu_nmi().
2587 * IRQ line should not be enabled for the current CPU.
2589 * As a CPU local operation, this should be called from non-preemptible
2592 void teardown_percpu_nmi(unsigned int irq)
2594 unsigned long flags;
2595 struct irq_desc *desc;
2597 WARN_ON(preemptible());
2599 desc = irq_get_desc_lock(irq, &flags,
2600 IRQ_GET_DESC_CHECK_PERCPU);
2604 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2607 irq_nmi_teardown(desc);
2609 irq_put_desc_unlock(desc, flags);
2612 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2615 struct irq_chip *chip;
2619 chip = irq_data_get_irq_chip(data);
2620 if (chip->irq_get_irqchip_state)
2622 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2623 data = data->parent_data;
2630 err = chip->irq_get_irqchip_state(data, which, state);
2635 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2636 * @irq: Interrupt line that is forwarded to a VM
2637 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2638 * @state: a pointer to a boolean where the state is to be storeed
2640 * This call snapshots the internal irqchip state of an
2641 * interrupt, returning into @state the bit corresponding to
2644 * This function should be called with preemption disabled if the
2645 * interrupt controller has per-cpu registers.
2647 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2650 struct irq_desc *desc;
2651 struct irq_data *data;
2652 unsigned long flags;
2655 desc = irq_get_desc_buslock(irq, &flags, 0);
2659 data = irq_desc_get_irq_data(desc);
2661 err = __irq_get_irqchip_state(data, which, state);
2663 irq_put_desc_busunlock(desc, flags);
2666 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2669 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2670 * @irq: Interrupt line that is forwarded to a VM
2671 * @which: State to be restored (one of IRQCHIP_STATE_*)
2672 * @val: Value corresponding to @which
2674 * This call sets the internal irqchip state of an interrupt,
2675 * depending on the value of @which.
2677 * This function should be called with preemption disabled if the
2678 * interrupt controller has per-cpu registers.
2680 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2683 struct irq_desc *desc;
2684 struct irq_data *data;
2685 struct irq_chip *chip;
2686 unsigned long flags;
2689 desc = irq_get_desc_buslock(irq, &flags, 0);
2693 data = irq_desc_get_irq_data(desc);
2696 chip = irq_data_get_irq_chip(data);
2697 if (chip->irq_set_irqchip_state)
2699 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2700 data = data->parent_data;
2707 err = chip->irq_set_irqchip_state(data, which, val);
2709 irq_put_desc_busunlock(desc, flags);
2712 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);