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 <linux/sched/isolation.h>
22 #include <uapi/linux/sched/types.h>
23 #include <linux/task_work.h>
25 #include "internals.h"
27 #if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28 __read_mostly bool force_irqthreads;
29 EXPORT_SYMBOL_GPL(force_irqthreads);
31 static int __init setup_forced_irqthreads(char *arg)
33 force_irqthreads = true;
36 early_param("threadirqs", setup_forced_irqthreads);
39 static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
41 struct irq_data *irqd = irq_desc_get_irq_data(desc);
48 * Wait until we're out of the critical section. This might
49 * give the wrong answer due to the lack of memory barriers.
51 while (irqd_irq_inprogress(&desc->irq_data))
54 /* Ok, that indicated we're done: double-check carefully. */
55 raw_spin_lock_irqsave(&desc->lock, flags);
56 inprogress = irqd_irq_inprogress(&desc->irq_data);
59 * If requested and supported, check at the chip whether it
60 * is in flight at the hardware level, i.e. already pending
61 * in a CPU and waiting for service and acknowledge.
63 if (!inprogress && sync_chip) {
65 * Ignore the return code. inprogress is only updated
66 * when the chip supports it.
68 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
71 raw_spin_unlock_irqrestore(&desc->lock, flags);
73 /* Oops, that failed? */
78 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
79 * @irq: interrupt number to wait for
81 * This function waits for any pending hard IRQ handlers for this
82 * interrupt to complete before returning. If you use this
83 * function while holding a resource the IRQ handler may need you
84 * will deadlock. It does not take associated threaded handlers
87 * Do not use this for shutdown scenarios where you must be sure
88 * that all parts (hardirq and threaded handler) have completed.
90 * Returns: false if a threaded handler is active.
92 * This function may be called - with care - from IRQ context.
94 * It does not check whether there is an interrupt in flight at the
95 * hardware level, but not serviced yet, as this might deadlock when
96 * called with interrupts disabled and the target CPU of the interrupt
99 bool synchronize_hardirq(unsigned int irq)
101 struct irq_desc *desc = irq_to_desc(irq);
104 __synchronize_hardirq(desc, false);
105 return !atomic_read(&desc->threads_active);
110 EXPORT_SYMBOL(synchronize_hardirq);
113 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
114 * @irq: interrupt number to wait for
116 * This function waits for any pending IRQ handlers for this interrupt
117 * to complete before returning. If you use this function while
118 * holding a resource the IRQ handler may need you will deadlock.
120 * Can only be called from preemptible code as it might sleep when
121 * an interrupt thread is associated to @irq.
123 * It optionally makes sure (when the irq chip supports that method)
124 * that the interrupt is not pending in any CPU and waiting for
127 void synchronize_irq(unsigned int irq)
129 struct irq_desc *desc = irq_to_desc(irq);
132 __synchronize_hardirq(desc, true);
134 * We made sure that no hardirq handler is
135 * running. Now verify that no threaded handlers are
138 wait_event(desc->wait_for_threads,
139 !atomic_read(&desc->threads_active));
142 EXPORT_SYMBOL(synchronize_irq);
145 cpumask_var_t irq_default_affinity;
147 static bool __irq_can_set_affinity(struct irq_desc *desc)
149 if (!desc || !irqd_can_balance(&desc->irq_data) ||
150 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
156 * irq_can_set_affinity - Check if the affinity of a given irq can be set
157 * @irq: Interrupt to check
160 int irq_can_set_affinity(unsigned int irq)
162 return __irq_can_set_affinity(irq_to_desc(irq));
166 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
167 * @irq: Interrupt to check
169 * Like irq_can_set_affinity() above, but additionally checks for the
170 * AFFINITY_MANAGED flag.
172 bool irq_can_set_affinity_usr(unsigned int irq)
174 struct irq_desc *desc = irq_to_desc(irq);
176 return __irq_can_set_affinity(desc) &&
177 !irqd_affinity_is_managed(&desc->irq_data);
181 * irq_set_thread_affinity - Notify irq threads to adjust affinity
182 * @desc: irq descriptor which has affitnity changed
184 * We just set IRQTF_AFFINITY and delegate the affinity setting
185 * to the interrupt thread itself. We can not call
186 * set_cpus_allowed_ptr() here as we hold desc->lock and this
187 * code can be called from hard interrupt context.
189 void irq_set_thread_affinity(struct irq_desc *desc)
191 struct irqaction *action;
193 for_each_action_of_desc(desc, action)
195 set_bit(IRQTF_AFFINITY, &action->thread_flags);
198 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
199 static void irq_validate_effective_affinity(struct irq_data *data)
201 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
202 struct irq_chip *chip = irq_data_get_irq_chip(data);
204 if (!cpumask_empty(m))
206 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
207 chip->name, data->irq);
210 static inline void irq_init_effective_affinity(struct irq_data *data,
211 const struct cpumask *mask)
213 cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
216 static inline void irq_validate_effective_affinity(struct irq_data *data) { }
217 static inline void irq_init_effective_affinity(struct irq_data *data,
218 const struct cpumask *mask) { }
221 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
224 struct irq_desc *desc = irq_data_to_desc(data);
225 struct irq_chip *chip = irq_data_get_irq_chip(data);
228 if (!chip || !chip->irq_set_affinity)
232 * If this is a managed interrupt and housekeeping is enabled on
233 * it check whether the requested affinity mask intersects with
234 * a housekeeping CPU. If so, then remove the isolated CPUs from
235 * the mask and just keep the housekeeping CPU(s). This prevents
236 * the affinity setter from routing the interrupt to an isolated
237 * CPU to avoid that I/O submitted from a housekeeping CPU causes
238 * interrupts on an isolated one.
240 * If the masks do not intersect or include online CPU(s) then
241 * keep the requested mask. The isolated target CPUs are only
242 * receiving interrupts when the I/O operation was submitted
243 * directly from them.
245 * If all housekeeping CPUs in the affinity mask are offline, the
246 * interrupt will be migrated by the CPU hotplug code once a
247 * housekeeping CPU which belongs to the affinity mask comes
250 if (irqd_affinity_is_managed(data) &&
251 housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
252 const struct cpumask *hk_mask, *prog_mask;
254 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
255 static struct cpumask tmp_mask;
257 hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
259 raw_spin_lock(&tmp_mask_lock);
260 cpumask_and(&tmp_mask, mask, hk_mask);
261 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
264 prog_mask = &tmp_mask;
265 ret = chip->irq_set_affinity(data, prog_mask, force);
266 raw_spin_unlock(&tmp_mask_lock);
268 ret = chip->irq_set_affinity(data, mask, force);
271 case IRQ_SET_MASK_OK:
272 case IRQ_SET_MASK_OK_DONE:
273 cpumask_copy(desc->irq_common_data.affinity, mask);
275 case IRQ_SET_MASK_OK_NOCOPY:
276 irq_validate_effective_affinity(data);
277 irq_set_thread_affinity(desc);
284 #ifdef CONFIG_GENERIC_PENDING_IRQ
285 static inline int irq_set_affinity_pending(struct irq_data *data,
286 const struct cpumask *dest)
288 struct irq_desc *desc = irq_data_to_desc(data);
290 irqd_set_move_pending(data);
291 irq_copy_pending(desc, dest);
295 static inline int irq_set_affinity_pending(struct irq_data *data,
296 const struct cpumask *dest)
302 static int irq_try_set_affinity(struct irq_data *data,
303 const struct cpumask *dest, bool force)
305 int ret = irq_do_set_affinity(data, dest, force);
308 * In case that the underlying vector management is busy and the
309 * architecture supports the generic pending mechanism then utilize
310 * this to avoid returning an error to user space.
312 if (ret == -EBUSY && !force)
313 ret = irq_set_affinity_pending(data, dest);
317 static bool irq_set_affinity_deactivated(struct irq_data *data,
318 const struct cpumask *mask, bool force)
320 struct irq_desc *desc = irq_data_to_desc(data);
323 * Handle irq chips which can handle affinity only in activated
326 * If the interrupt is not yet activated, just store the affinity
327 * mask and do not call the chip driver at all. On activation the
328 * driver has to make sure anyway that the interrupt is in a
329 * useable state so startup works.
331 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
332 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
335 cpumask_copy(desc->irq_common_data.affinity, mask);
336 irq_init_effective_affinity(data, mask);
337 irqd_set(data, IRQD_AFFINITY_SET);
341 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
344 struct irq_chip *chip = irq_data_get_irq_chip(data);
345 struct irq_desc *desc = irq_data_to_desc(data);
348 if (!chip || !chip->irq_set_affinity)
351 if (irq_set_affinity_deactivated(data, mask, force))
354 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
355 ret = irq_try_set_affinity(data, mask, force);
357 irqd_set_move_pending(data);
358 irq_copy_pending(desc, mask);
361 if (desc->affinity_notify) {
362 kref_get(&desc->affinity_notify->kref);
363 if (!schedule_work(&desc->affinity_notify->work)) {
364 /* Work was already scheduled, drop our extra ref */
365 kref_put(&desc->affinity_notify->kref,
366 desc->affinity_notify->release);
369 irqd_set(data, IRQD_AFFINITY_SET);
374 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
376 struct irq_desc *desc = irq_to_desc(irq);
383 raw_spin_lock_irqsave(&desc->lock, flags);
384 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
385 raw_spin_unlock_irqrestore(&desc->lock, flags);
389 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
392 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
396 desc->affinity_hint = m;
397 irq_put_desc_unlock(desc, flags);
398 /* set the initial affinity to prevent every interrupt being on CPU0 */
400 __irq_set_affinity(irq, m, false);
403 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
405 static void irq_affinity_notify(struct work_struct *work)
407 struct irq_affinity_notify *notify =
408 container_of(work, struct irq_affinity_notify, work);
409 struct irq_desc *desc = irq_to_desc(notify->irq);
410 cpumask_var_t cpumask;
413 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
416 raw_spin_lock_irqsave(&desc->lock, flags);
417 if (irq_move_pending(&desc->irq_data))
418 irq_get_pending(cpumask, desc);
420 cpumask_copy(cpumask, desc->irq_common_data.affinity);
421 raw_spin_unlock_irqrestore(&desc->lock, flags);
423 notify->notify(notify, cpumask);
425 free_cpumask_var(cpumask);
427 kref_put(¬ify->kref, notify->release);
431 * irq_set_affinity_notifier - control notification of IRQ affinity changes
432 * @irq: Interrupt for which to enable/disable notification
433 * @notify: Context for notification, or %NULL to disable
434 * notification. Function pointers must be initialised;
435 * the other fields will be initialised by this function.
437 * Must be called in process context. Notification may only be enabled
438 * after the IRQ is allocated and must be disabled before the IRQ is
439 * freed using free_irq().
442 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
444 struct irq_desc *desc = irq_to_desc(irq);
445 struct irq_affinity_notify *old_notify;
448 /* The release function is promised process context */
451 if (!desc || desc->istate & IRQS_NMI)
454 /* Complete initialisation of *notify */
457 kref_init(¬ify->kref);
458 INIT_WORK(¬ify->work, irq_affinity_notify);
461 raw_spin_lock_irqsave(&desc->lock, flags);
462 old_notify = desc->affinity_notify;
463 desc->affinity_notify = notify;
464 raw_spin_unlock_irqrestore(&desc->lock, flags);
467 if (cancel_work_sync(&old_notify->work)) {
468 /* Pending work had a ref, put that one too */
469 kref_put(&old_notify->kref, old_notify->release);
471 kref_put(&old_notify->kref, old_notify->release);
476 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
478 #ifndef CONFIG_AUTO_IRQ_AFFINITY
480 * Generic version of the affinity autoselector.
482 int irq_setup_affinity(struct irq_desc *desc)
484 struct cpumask *set = irq_default_affinity;
485 int ret, node = irq_desc_get_node(desc);
486 static DEFINE_RAW_SPINLOCK(mask_lock);
487 static struct cpumask mask;
489 /* Excludes PER_CPU and NO_BALANCE interrupts */
490 if (!__irq_can_set_affinity(desc))
493 raw_spin_lock(&mask_lock);
495 * Preserve the managed affinity setting and a userspace affinity
496 * setup, but make sure that one of the targets is online.
498 if (irqd_affinity_is_managed(&desc->irq_data) ||
499 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
500 if (cpumask_intersects(desc->irq_common_data.affinity,
502 set = desc->irq_common_data.affinity;
504 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
507 cpumask_and(&mask, cpu_online_mask, set);
508 if (cpumask_empty(&mask))
509 cpumask_copy(&mask, cpu_online_mask);
511 if (node != NUMA_NO_NODE) {
512 const struct cpumask *nodemask = cpumask_of_node(node);
514 /* make sure at least one of the cpus in nodemask is online */
515 if (cpumask_intersects(&mask, nodemask))
516 cpumask_and(&mask, &mask, nodemask);
518 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
519 raw_spin_unlock(&mask_lock);
523 /* Wrapper for ALPHA specific affinity selector magic */
524 int irq_setup_affinity(struct irq_desc *desc)
526 return irq_select_affinity(irq_desc_get_irq(desc));
528 #endif /* CONFIG_AUTO_IRQ_AFFINITY */
529 #endif /* CONFIG_SMP */
533 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
534 * @irq: interrupt number to set affinity
535 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
536 * specific data for percpu_devid interrupts
538 * This function uses the vCPU specific data to set the vCPU
539 * affinity for an irq. The vCPU specific data is passed from
540 * outside, such as KVM. One example code path is as below:
541 * KVM -> IOMMU -> irq_set_vcpu_affinity().
543 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
546 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
547 struct irq_data *data;
548 struct irq_chip *chip;
554 data = irq_desc_get_irq_data(desc);
556 chip = irq_data_get_irq_chip(data);
557 if (chip && chip->irq_set_vcpu_affinity)
559 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
560 data = data->parent_data;
567 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
568 irq_put_desc_unlock(desc, flags);
572 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
574 void __disable_irq(struct irq_desc *desc)
580 static int __disable_irq_nosync(unsigned int irq)
583 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
588 irq_put_desc_busunlock(desc, flags);
593 * disable_irq_nosync - disable an irq without waiting
594 * @irq: Interrupt to disable
596 * Disable the selected interrupt line. Disables and Enables are
598 * Unlike disable_irq(), this function does not ensure existing
599 * instances of the IRQ handler have completed before returning.
601 * This function may be called from IRQ context.
603 void disable_irq_nosync(unsigned int irq)
605 __disable_irq_nosync(irq);
607 EXPORT_SYMBOL(disable_irq_nosync);
610 * disable_irq - disable an irq and wait for completion
611 * @irq: Interrupt to disable
613 * Disable the selected interrupt line. Enables and Disables are
615 * This function waits for any pending IRQ handlers for this interrupt
616 * to complete before returning. If you use this function while
617 * holding a resource the IRQ handler may need you will deadlock.
619 * This function may be called - with care - from IRQ context.
621 void disable_irq(unsigned int irq)
623 if (!__disable_irq_nosync(irq))
624 synchronize_irq(irq);
626 EXPORT_SYMBOL(disable_irq);
629 * disable_hardirq - disables an irq and waits for hardirq completion
630 * @irq: Interrupt to disable
632 * Disable the selected interrupt line. Enables and Disables are
634 * This function waits for any pending hard IRQ handlers for this
635 * interrupt to complete before returning. If you use this function while
636 * holding a resource the hard IRQ handler may need you will deadlock.
638 * When used to optimistically disable an interrupt from atomic context
639 * the return value must be checked.
641 * Returns: false if a threaded handler is active.
643 * This function may be called - with care - from IRQ context.
645 bool disable_hardirq(unsigned int irq)
647 if (!__disable_irq_nosync(irq))
648 return synchronize_hardirq(irq);
652 EXPORT_SYMBOL_GPL(disable_hardirq);
655 * disable_nmi_nosync - disable an nmi without waiting
656 * @irq: Interrupt to disable
658 * Disable the selected interrupt line. Disables and enables are
660 * The interrupt to disable must have been requested through request_nmi.
661 * Unlike disable_nmi(), this function does not ensure existing
662 * instances of the IRQ handler have completed before returning.
664 void disable_nmi_nosync(unsigned int irq)
666 disable_irq_nosync(irq);
669 void __enable_irq(struct irq_desc *desc)
671 switch (desc->depth) {
674 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
675 irq_desc_get_irq(desc));
678 if (desc->istate & IRQS_SUSPENDED)
680 /* Prevent probing on this irq: */
681 irq_settings_set_noprobe(desc);
683 * Call irq_startup() not irq_enable() here because the
684 * interrupt might be marked NOAUTOEN. So irq_startup()
685 * needs to be invoked when it gets enabled the first
686 * time. If it was already started up, then irq_startup()
687 * will invoke irq_enable() under the hood.
689 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
698 * enable_irq - enable handling of an irq
699 * @irq: Interrupt to enable
701 * Undoes the effect of one call to disable_irq(). If this
702 * matches the last disable, processing of interrupts on this
703 * IRQ line is re-enabled.
705 * This function may be called from IRQ context only when
706 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
708 void enable_irq(unsigned int irq)
711 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
715 if (WARN(!desc->irq_data.chip,
716 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
721 irq_put_desc_busunlock(desc, flags);
723 EXPORT_SYMBOL(enable_irq);
726 * enable_nmi - enable handling of an nmi
727 * @irq: Interrupt to enable
729 * The interrupt to enable must have been requested through request_nmi.
730 * Undoes the effect of one call to disable_nmi(). If this
731 * matches the last disable, processing of interrupts on this
732 * IRQ line is re-enabled.
734 void enable_nmi(unsigned int irq)
739 static int set_irq_wake_real(unsigned int irq, unsigned int on)
741 struct irq_desc *desc = irq_to_desc(irq);
744 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
747 if (desc->irq_data.chip->irq_set_wake)
748 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
754 * irq_set_irq_wake - control irq power management wakeup
755 * @irq: interrupt to control
756 * @on: enable/disable power management wakeup
758 * Enable/disable power management wakeup mode, which is
759 * disabled by default. Enables and disables must match,
760 * just as they match for non-wakeup mode support.
762 * Wakeup mode lets this IRQ wake the system from sleep
763 * states like "suspend to RAM".
765 * Note: irq enable/disable state is completely orthogonal
766 * to the enable/disable state of irq wake. An irq can be
767 * disabled with disable_irq() and still wake the system as
768 * long as the irq has wake enabled. If this does not hold,
769 * then the underlying irq chip and the related driver need
770 * to be investigated.
772 int irq_set_irq_wake(unsigned int irq, unsigned int on)
775 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
781 /* Don't use NMIs as wake up interrupts please */
782 if (desc->istate & IRQS_NMI) {
787 /* wakeup-capable irqs can be shared between drivers that
788 * don't need to have the same sleep mode behaviors.
791 if (desc->wake_depth++ == 0) {
792 ret = set_irq_wake_real(irq, on);
794 desc->wake_depth = 0;
796 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
799 if (desc->wake_depth == 0) {
800 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
801 } else if (--desc->wake_depth == 0) {
802 ret = set_irq_wake_real(irq, on);
804 desc->wake_depth = 1;
806 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
811 irq_put_desc_busunlock(desc, flags);
814 EXPORT_SYMBOL(irq_set_irq_wake);
817 * Internal function that tells the architecture code whether a
818 * particular irq has been exclusively allocated or is available
821 int can_request_irq(unsigned int irq, unsigned long irqflags)
824 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
830 if (irq_settings_can_request(desc)) {
832 irqflags & desc->action->flags & IRQF_SHARED)
835 irq_put_desc_unlock(desc, flags);
839 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
841 struct irq_chip *chip = desc->irq_data.chip;
844 if (!chip || !chip->irq_set_type) {
846 * IRQF_TRIGGER_* but the PIC does not support multiple
849 pr_debug("No set_type function for IRQ %d (%s)\n",
850 irq_desc_get_irq(desc),
851 chip ? (chip->name ? : "unknown") : "unknown");
855 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
856 if (!irqd_irq_masked(&desc->irq_data))
858 if (!irqd_irq_disabled(&desc->irq_data))
862 /* Mask all flags except trigger mode */
863 flags &= IRQ_TYPE_SENSE_MASK;
864 ret = chip->irq_set_type(&desc->irq_data, flags);
867 case IRQ_SET_MASK_OK:
868 case IRQ_SET_MASK_OK_DONE:
869 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
870 irqd_set(&desc->irq_data, flags);
873 case IRQ_SET_MASK_OK_NOCOPY:
874 flags = irqd_get_trigger_type(&desc->irq_data);
875 irq_settings_set_trigger_mask(desc, flags);
876 irqd_clear(&desc->irq_data, IRQD_LEVEL);
877 irq_settings_clr_level(desc);
878 if (flags & IRQ_TYPE_LEVEL_MASK) {
879 irq_settings_set_level(desc);
880 irqd_set(&desc->irq_data, IRQD_LEVEL);
886 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
887 flags, irq_desc_get_irq(desc), chip->irq_set_type);
894 #ifdef CONFIG_HARDIRQS_SW_RESEND
895 int irq_set_parent(int irq, int parent_irq)
898 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
903 desc->parent_irq = parent_irq;
905 irq_put_desc_unlock(desc, flags);
908 EXPORT_SYMBOL_GPL(irq_set_parent);
912 * Default primary interrupt handler for threaded interrupts. Is
913 * assigned as primary handler when request_threaded_irq is called
914 * with handler == NULL. Useful for oneshot interrupts.
916 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
918 return IRQ_WAKE_THREAD;
922 * Primary handler for nested threaded interrupts. Should never be
925 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
927 WARN(1, "Primary handler called for nested irq %d\n", irq);
931 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
933 WARN(1, "Secondary action handler called for irq %d\n", irq);
937 static int irq_wait_for_interrupt(struct irqaction *action)
940 set_current_state(TASK_INTERRUPTIBLE);
942 if (kthread_should_stop()) {
943 /* may need to run one last time */
944 if (test_and_clear_bit(IRQTF_RUNTHREAD,
945 &action->thread_flags)) {
946 __set_current_state(TASK_RUNNING);
949 __set_current_state(TASK_RUNNING);
953 if (test_and_clear_bit(IRQTF_RUNTHREAD,
954 &action->thread_flags)) {
955 __set_current_state(TASK_RUNNING);
963 * Oneshot interrupts keep the irq line masked until the threaded
964 * handler finished. unmask if the interrupt has not been disabled and
967 static void irq_finalize_oneshot(struct irq_desc *desc,
968 struct irqaction *action)
970 if (!(desc->istate & IRQS_ONESHOT) ||
971 action->handler == irq_forced_secondary_handler)
975 raw_spin_lock_irq(&desc->lock);
978 * Implausible though it may be we need to protect us against
979 * the following scenario:
981 * The thread is faster done than the hard interrupt handler
982 * on the other CPU. If we unmask the irq line then the
983 * interrupt can come in again and masks the line, leaves due
984 * to IRQS_INPROGRESS and the irq line is masked forever.
986 * This also serializes the state of shared oneshot handlers
987 * versus "desc->threads_onehsot |= action->thread_mask;" in
988 * irq_wake_thread(). See the comment there which explains the
991 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
992 raw_spin_unlock_irq(&desc->lock);
993 chip_bus_sync_unlock(desc);
999 * Now check again, whether the thread should run. Otherwise
1000 * we would clear the threads_oneshot bit of this thread which
1003 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1006 desc->threads_oneshot &= ~action->thread_mask;
1008 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1009 irqd_irq_masked(&desc->irq_data))
1010 unmask_threaded_irq(desc);
1013 raw_spin_unlock_irq(&desc->lock);
1014 chip_bus_sync_unlock(desc);
1019 * Check whether we need to change the affinity of the interrupt thread.
1022 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1027 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1031 * In case we are out of memory we set IRQTF_AFFINITY again and
1032 * try again next time
1034 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1035 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1039 raw_spin_lock_irq(&desc->lock);
1041 * This code is triggered unconditionally. Check the affinity
1042 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1044 if (cpumask_available(desc->irq_common_data.affinity)) {
1045 const struct cpumask *m;
1047 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1048 cpumask_copy(mask, m);
1052 raw_spin_unlock_irq(&desc->lock);
1055 set_cpus_allowed_ptr(current, mask);
1056 free_cpumask_var(mask);
1060 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1064 * Interrupts which are not explicitly requested as threaded
1065 * interrupts rely on the implicit bh/preempt disable of the hard irq
1066 * context. So we need to disable bh here to avoid deadlocks and other
1070 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1075 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1076 local_irq_disable();
1077 ret = action->thread_fn(action->irq, action->dev_id);
1078 if (ret == IRQ_HANDLED)
1079 atomic_inc(&desc->threads_handled);
1081 irq_finalize_oneshot(desc, action);
1082 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1089 * Interrupts explicitly requested as threaded interrupts want to be
1090 * preemtible - many of them need to sleep and wait for slow busses to
1093 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1094 struct irqaction *action)
1098 ret = action->thread_fn(action->irq, action->dev_id);
1099 if (ret == IRQ_HANDLED)
1100 atomic_inc(&desc->threads_handled);
1102 irq_finalize_oneshot(desc, action);
1106 static void wake_threads_waitq(struct irq_desc *desc)
1108 if (atomic_dec_and_test(&desc->threads_active))
1109 wake_up(&desc->wait_for_threads);
1112 static void irq_thread_dtor(struct callback_head *unused)
1114 struct task_struct *tsk = current;
1115 struct irq_desc *desc;
1116 struct irqaction *action;
1118 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1121 action = kthread_data(tsk);
1123 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1124 tsk->comm, tsk->pid, action->irq);
1127 desc = irq_to_desc(action->irq);
1129 * If IRQTF_RUNTHREAD is set, we need to decrement
1130 * desc->threads_active and wake possible waiters.
1132 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1133 wake_threads_waitq(desc);
1135 /* Prevent a stale desc->threads_oneshot */
1136 irq_finalize_oneshot(desc, action);
1139 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1141 struct irqaction *secondary = action->secondary;
1143 if (WARN_ON_ONCE(!secondary))
1146 raw_spin_lock_irq(&desc->lock);
1147 __irq_wake_thread(desc, secondary);
1148 raw_spin_unlock_irq(&desc->lock);
1152 * Interrupt handler thread
1154 static int irq_thread(void *data)
1156 struct callback_head on_exit_work;
1157 struct irqaction *action = data;
1158 struct irq_desc *desc = irq_to_desc(action->irq);
1159 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1160 struct irqaction *action);
1162 sched_set_fifo(current);
1164 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1165 &action->thread_flags))
1166 handler_fn = irq_forced_thread_fn;
1168 handler_fn = irq_thread_fn;
1170 init_task_work(&on_exit_work, irq_thread_dtor);
1171 task_work_add(current, &on_exit_work, TWA_NONE);
1173 irq_thread_check_affinity(desc, action);
1175 while (!irq_wait_for_interrupt(action)) {
1176 irqreturn_t action_ret;
1178 irq_thread_check_affinity(desc, action);
1180 action_ret = handler_fn(desc, action);
1181 if (action_ret == IRQ_WAKE_THREAD)
1182 irq_wake_secondary(desc, action);
1184 if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
1186 add_interrupt_randomness(action->irq, 0,
1187 desc->random_ip ^ (unsigned long) action);
1190 wake_threads_waitq(desc);
1194 * This is the regular exit path. __free_irq() is stopping the
1195 * thread via kthread_stop() after calling
1196 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1197 * oneshot mask bit can be set.
1199 task_work_cancel(current, irq_thread_dtor);
1204 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1205 * @irq: Interrupt line
1206 * @dev_id: Device identity for which the thread should be woken
1209 void irq_wake_thread(unsigned int irq, void *dev_id)
1211 struct irq_desc *desc = irq_to_desc(irq);
1212 struct irqaction *action;
1213 unsigned long flags;
1215 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1218 raw_spin_lock_irqsave(&desc->lock, flags);
1219 for_each_action_of_desc(desc, action) {
1220 if (action->dev_id == dev_id) {
1222 __irq_wake_thread(desc, action);
1226 raw_spin_unlock_irqrestore(&desc->lock, flags);
1228 EXPORT_SYMBOL_GPL(irq_wake_thread);
1230 static int irq_setup_forced_threading(struct irqaction *new)
1232 if (!force_irqthreads)
1234 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1238 * No further action required for interrupts which are requested as
1239 * threaded interrupts already
1241 if (new->handler == irq_default_primary_handler)
1244 new->flags |= IRQF_ONESHOT;
1247 * Handle the case where we have a real primary handler and a
1248 * thread handler. We force thread them as well by creating a
1251 if (new->handler && new->thread_fn) {
1252 /* Allocate the secondary action */
1253 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1254 if (!new->secondary)
1256 new->secondary->handler = irq_forced_secondary_handler;
1257 new->secondary->thread_fn = new->thread_fn;
1258 new->secondary->dev_id = new->dev_id;
1259 new->secondary->irq = new->irq;
1260 new->secondary->name = new->name;
1262 /* Deal with the primary handler */
1263 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1264 new->thread_fn = new->handler;
1265 new->handler = irq_default_primary_handler;
1269 static int irq_request_resources(struct irq_desc *desc)
1271 struct irq_data *d = &desc->irq_data;
1272 struct irq_chip *c = d->chip;
1274 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1277 static void irq_release_resources(struct irq_desc *desc)
1279 struct irq_data *d = &desc->irq_data;
1280 struct irq_chip *c = d->chip;
1282 if (c->irq_release_resources)
1283 c->irq_release_resources(d);
1286 static bool irq_supports_nmi(struct irq_desc *desc)
1288 struct irq_data *d = irq_desc_get_irq_data(desc);
1290 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1291 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1295 /* Don't support NMIs for chips behind a slow bus */
1296 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1299 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1302 static int irq_nmi_setup(struct irq_desc *desc)
1304 struct irq_data *d = irq_desc_get_irq_data(desc);
1305 struct irq_chip *c = d->chip;
1307 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1310 static void irq_nmi_teardown(struct irq_desc *desc)
1312 struct irq_data *d = irq_desc_get_irq_data(desc);
1313 struct irq_chip *c = d->chip;
1315 if (c->irq_nmi_teardown)
1316 c->irq_nmi_teardown(d);
1320 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1322 struct task_struct *t;
1325 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1328 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1336 * We keep the reference to the task struct even if
1337 * the thread dies to avoid that the interrupt code
1338 * references an already freed task_struct.
1340 new->thread = get_task_struct(t);
1342 * Tell the thread to set its affinity. This is
1343 * important for shared interrupt handlers as we do
1344 * not invoke setup_affinity() for the secondary
1345 * handlers as everything is already set up. Even for
1346 * interrupts marked with IRQF_NO_BALANCE this is
1347 * correct as we want the thread to move to the cpu(s)
1348 * on which the requesting code placed the interrupt.
1350 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1355 * Internal function to register an irqaction - typically used to
1356 * allocate special interrupts that are part of the architecture.
1360 * desc->request_mutex Provides serialization against a concurrent free_irq()
1361 * chip_bus_lock Provides serialization for slow bus operations
1362 * desc->lock Provides serialization against hard interrupts
1364 * chip_bus_lock and desc->lock are sufficient for all other management and
1365 * interrupt related functions. desc->request_mutex solely serializes
1366 * request/free_irq().
1369 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1371 struct irqaction *old, **old_ptr;
1372 unsigned long flags, thread_mask = 0;
1373 int ret, nested, shared = 0;
1378 if (desc->irq_data.chip == &no_irq_chip)
1380 if (!try_module_get(desc->owner))
1386 * If the trigger type is not specified by the caller,
1387 * then use the default for this interrupt.
1389 if (!(new->flags & IRQF_TRIGGER_MASK))
1390 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1393 * Check whether the interrupt nests into another interrupt
1396 nested = irq_settings_is_nested_thread(desc);
1398 if (!new->thread_fn) {
1403 * Replace the primary handler which was provided from
1404 * the driver for non nested interrupt handling by the
1405 * dummy function which warns when called.
1407 new->handler = irq_nested_primary_handler;
1409 if (irq_settings_can_thread(desc)) {
1410 ret = irq_setup_forced_threading(new);
1417 * Create a handler thread when a thread function is supplied
1418 * and the interrupt does not nest into another interrupt
1421 if (new->thread_fn && !nested) {
1422 ret = setup_irq_thread(new, irq, false);
1425 if (new->secondary) {
1426 ret = setup_irq_thread(new->secondary, irq, true);
1433 * Drivers are often written to work w/o knowledge about the
1434 * underlying irq chip implementation, so a request for a
1435 * threaded irq without a primary hard irq context handler
1436 * requires the ONESHOT flag to be set. Some irq chips like
1437 * MSI based interrupts are per se one shot safe. Check the
1438 * chip flags, so we can avoid the unmask dance at the end of
1439 * the threaded handler for those.
1441 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1442 new->flags &= ~IRQF_ONESHOT;
1445 * Protects against a concurrent __free_irq() call which might wait
1446 * for synchronize_hardirq() to complete without holding the optional
1447 * chip bus lock and desc->lock. Also protects against handing out
1448 * a recycled oneshot thread_mask bit while it's still in use by
1449 * its previous owner.
1451 mutex_lock(&desc->request_mutex);
1454 * Acquire bus lock as the irq_request_resources() callback below
1455 * might rely on the serialization or the magic power management
1456 * functions which are abusing the irq_bus_lock() callback,
1458 chip_bus_lock(desc);
1460 /* First installed action requests resources. */
1461 if (!desc->action) {
1462 ret = irq_request_resources(desc);
1464 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1465 new->name, irq, desc->irq_data.chip->name);
1466 goto out_bus_unlock;
1471 * The following block of code has to be executed atomically
1472 * protected against a concurrent interrupt and any of the other
1473 * management calls which are not serialized via
1474 * desc->request_mutex or the optional bus lock.
1476 raw_spin_lock_irqsave(&desc->lock, flags);
1477 old_ptr = &desc->action;
1481 * Can't share interrupts unless both agree to and are
1482 * the same type (level, edge, polarity). So both flag
1483 * fields must have IRQF_SHARED set and the bits which
1484 * set the trigger type must match. Also all must
1486 * Interrupt lines used for NMIs cannot be shared.
1488 unsigned int oldtype;
1490 if (desc->istate & IRQS_NMI) {
1491 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1492 new->name, irq, desc->irq_data.chip->name);
1498 * If nobody did set the configuration before, inherit
1499 * the one provided by the requester.
1501 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1502 oldtype = irqd_get_trigger_type(&desc->irq_data);
1504 oldtype = new->flags & IRQF_TRIGGER_MASK;
1505 irqd_set_trigger_type(&desc->irq_data, oldtype);
1508 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1509 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1510 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1513 /* All handlers must agree on per-cpuness */
1514 if ((old->flags & IRQF_PERCPU) !=
1515 (new->flags & IRQF_PERCPU))
1518 /* add new interrupt at end of irq queue */
1521 * Or all existing action->thread_mask bits,
1522 * so we can find the next zero bit for this
1525 thread_mask |= old->thread_mask;
1526 old_ptr = &old->next;
1533 * Setup the thread mask for this irqaction for ONESHOT. For
1534 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1535 * conditional in irq_wake_thread().
1537 if (new->flags & IRQF_ONESHOT) {
1539 * Unlikely to have 32 resp 64 irqs sharing one line,
1542 if (thread_mask == ~0UL) {
1547 * The thread_mask for the action is or'ed to
1548 * desc->thread_active to indicate that the
1549 * IRQF_ONESHOT thread handler has been woken, but not
1550 * yet finished. The bit is cleared when a thread
1551 * completes. When all threads of a shared interrupt
1552 * line have completed desc->threads_active becomes
1553 * zero and the interrupt line is unmasked. See
1554 * handle.c:irq_wake_thread() for further information.
1556 * If no thread is woken by primary (hard irq context)
1557 * interrupt handlers, then desc->threads_active is
1558 * also checked for zero to unmask the irq line in the
1559 * affected hard irq flow handlers
1560 * (handle_[fasteoi|level]_irq).
1562 * The new action gets the first zero bit of
1563 * thread_mask assigned. See the loop above which or's
1564 * all existing action->thread_mask bits.
1566 new->thread_mask = 1UL << ffz(thread_mask);
1568 } else if (new->handler == irq_default_primary_handler &&
1569 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1571 * The interrupt was requested with handler = NULL, so
1572 * we use the default primary handler for it. But it
1573 * does not have the oneshot flag set. In combination
1574 * with level interrupts this is deadly, because the
1575 * default primary handler just wakes the thread, then
1576 * the irq lines is reenabled, but the device still
1577 * has the level irq asserted. Rinse and repeat....
1579 * While this works for edge type interrupts, we play
1580 * it safe and reject unconditionally because we can't
1581 * say for sure which type this interrupt really
1582 * has. The type flags are unreliable as the
1583 * underlying chip implementation can override them.
1585 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1592 init_waitqueue_head(&desc->wait_for_threads);
1594 /* Setup the type (level, edge polarity) if configured: */
1595 if (new->flags & IRQF_TRIGGER_MASK) {
1596 ret = __irq_set_trigger(desc,
1597 new->flags & IRQF_TRIGGER_MASK);
1604 * Activate the interrupt. That activation must happen
1605 * independently of IRQ_NOAUTOEN. request_irq() can fail
1606 * and the callers are supposed to handle
1607 * that. enable_irq() of an interrupt requested with
1608 * IRQ_NOAUTOEN is not supposed to fail. The activation
1609 * keeps it in shutdown mode, it merily associates
1610 * resources if necessary and if that's not possible it
1611 * fails. Interrupts which are in managed shutdown mode
1612 * will simply ignore that activation request.
1614 ret = irq_activate(desc);
1618 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1619 IRQS_ONESHOT | IRQS_WAITING);
1620 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1622 if (new->flags & IRQF_PERCPU) {
1623 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1624 irq_settings_set_per_cpu(desc);
1627 if (new->flags & IRQF_ONESHOT)
1628 desc->istate |= IRQS_ONESHOT;
1630 /* Exclude IRQ from balancing if requested */
1631 if (new->flags & IRQF_NOBALANCING) {
1632 irq_settings_set_no_balancing(desc);
1633 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1636 if (irq_settings_can_autoenable(desc)) {
1637 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1640 * Shared interrupts do not go well with disabling
1641 * auto enable. The sharing interrupt might request
1642 * it while it's still disabled and then wait for
1643 * interrupts forever.
1645 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1646 /* Undo nested disables: */
1650 } else if (new->flags & IRQF_TRIGGER_MASK) {
1651 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1652 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1655 /* hope the handler works with current trigger mode */
1656 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1662 irq_pm_install_action(desc, new);
1664 /* Reset broken irq detection when installing new handler */
1665 desc->irq_count = 0;
1666 desc->irqs_unhandled = 0;
1669 * Check whether we disabled the irq via the spurious handler
1670 * before. Reenable it and give it another chance.
1672 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1673 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1677 raw_spin_unlock_irqrestore(&desc->lock, flags);
1678 chip_bus_sync_unlock(desc);
1679 mutex_unlock(&desc->request_mutex);
1681 irq_setup_timings(desc, new);
1684 * Strictly no need to wake it up, but hung_task complains
1685 * when no hard interrupt wakes the thread up.
1688 wake_up_process(new->thread);
1690 wake_up_process(new->secondary->thread);
1692 register_irq_proc(irq, desc);
1694 register_handler_proc(irq, new);
1698 if (!(new->flags & IRQF_PROBE_SHARED)) {
1699 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1700 irq, new->flags, new->name, old->flags, old->name);
1701 #ifdef CONFIG_DEBUG_SHIRQ
1708 raw_spin_unlock_irqrestore(&desc->lock, flags);
1711 irq_release_resources(desc);
1713 chip_bus_sync_unlock(desc);
1714 mutex_unlock(&desc->request_mutex);
1718 struct task_struct *t = new->thread;
1724 if (new->secondary && new->secondary->thread) {
1725 struct task_struct *t = new->secondary->thread;
1727 new->secondary->thread = NULL;
1732 module_put(desc->owner);
1737 * Internal function to unregister an irqaction - used to free
1738 * regular and special interrupts that are part of the architecture.
1740 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1742 unsigned irq = desc->irq_data.irq;
1743 struct irqaction *action, **action_ptr;
1744 unsigned long flags;
1746 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1748 mutex_lock(&desc->request_mutex);
1749 chip_bus_lock(desc);
1750 raw_spin_lock_irqsave(&desc->lock, flags);
1753 * There can be multiple actions per IRQ descriptor, find the right
1754 * one based on the dev_id:
1756 action_ptr = &desc->action;
1758 action = *action_ptr;
1761 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1762 raw_spin_unlock_irqrestore(&desc->lock, flags);
1763 chip_bus_sync_unlock(desc);
1764 mutex_unlock(&desc->request_mutex);
1768 if (action->dev_id == dev_id)
1770 action_ptr = &action->next;
1773 /* Found it - now remove it from the list of entries: */
1774 *action_ptr = action->next;
1776 irq_pm_remove_action(desc, action);
1778 /* If this was the last handler, shut down the IRQ line: */
1779 if (!desc->action) {
1780 irq_settings_clr_disable_unlazy(desc);
1781 /* Only shutdown. Deactivate after synchronize_hardirq() */
1786 /* make sure affinity_hint is cleaned up */
1787 if (WARN_ON_ONCE(desc->affinity_hint))
1788 desc->affinity_hint = NULL;
1791 raw_spin_unlock_irqrestore(&desc->lock, flags);
1793 * Drop bus_lock here so the changes which were done in the chip
1794 * callbacks above are synced out to the irq chips which hang
1795 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1797 * Aside of that the bus_lock can also be taken from the threaded
1798 * handler in irq_finalize_oneshot() which results in a deadlock
1799 * because kthread_stop() would wait forever for the thread to
1800 * complete, which is blocked on the bus lock.
1802 * The still held desc->request_mutex() protects against a
1803 * concurrent request_irq() of this irq so the release of resources
1804 * and timing data is properly serialized.
1806 chip_bus_sync_unlock(desc);
1808 unregister_handler_proc(irq, action);
1811 * Make sure it's not being used on another CPU and if the chip
1812 * supports it also make sure that there is no (not yet serviced)
1813 * interrupt in flight at the hardware level.
1815 __synchronize_hardirq(desc, true);
1817 #ifdef CONFIG_DEBUG_SHIRQ
1819 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1820 * event to happen even now it's being freed, so let's make sure that
1821 * is so by doing an extra call to the handler ....
1823 * ( We do this after actually deregistering it, to make sure that a
1824 * 'real' IRQ doesn't run in parallel with our fake. )
1826 if (action->flags & IRQF_SHARED) {
1827 local_irq_save(flags);
1828 action->handler(irq, dev_id);
1829 local_irq_restore(flags);
1834 * The action has already been removed above, but the thread writes
1835 * its oneshot mask bit when it completes. Though request_mutex is
1836 * held across this which prevents __setup_irq() from handing out
1837 * the same bit to a newly requested action.
1839 if (action->thread) {
1840 kthread_stop(action->thread);
1841 put_task_struct(action->thread);
1842 if (action->secondary && action->secondary->thread) {
1843 kthread_stop(action->secondary->thread);
1844 put_task_struct(action->secondary->thread);
1848 /* Last action releases resources */
1849 if (!desc->action) {
1851 * Reaquire bus lock as irq_release_resources() might
1852 * require it to deallocate resources over the slow bus.
1854 chip_bus_lock(desc);
1856 * There is no interrupt on the fly anymore. Deactivate it
1859 raw_spin_lock_irqsave(&desc->lock, flags);
1860 irq_domain_deactivate_irq(&desc->irq_data);
1861 raw_spin_unlock_irqrestore(&desc->lock, flags);
1863 irq_release_resources(desc);
1864 chip_bus_sync_unlock(desc);
1865 irq_remove_timings(desc);
1868 mutex_unlock(&desc->request_mutex);
1870 irq_chip_pm_put(&desc->irq_data);
1871 module_put(desc->owner);
1872 kfree(action->secondary);
1877 * free_irq - free an interrupt allocated with request_irq
1878 * @irq: Interrupt line to free
1879 * @dev_id: Device identity to free
1881 * Remove an interrupt handler. The handler is removed and if the
1882 * interrupt line is no longer in use by any driver it is disabled.
1883 * On a shared IRQ the caller must ensure the interrupt is disabled
1884 * on the card it drives before calling this function. The function
1885 * does not return until any executing interrupts for this IRQ
1888 * This function must not be called from interrupt context.
1890 * Returns the devname argument passed to request_irq.
1892 const void *free_irq(unsigned int irq, void *dev_id)
1894 struct irq_desc *desc = irq_to_desc(irq);
1895 struct irqaction *action;
1896 const char *devname;
1898 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1902 if (WARN_ON(desc->affinity_notify))
1903 desc->affinity_notify = NULL;
1906 action = __free_irq(desc, dev_id);
1911 devname = action->name;
1915 EXPORT_SYMBOL(free_irq);
1917 /* This function must be called with desc->lock held */
1918 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1920 const char *devname = NULL;
1922 desc->istate &= ~IRQS_NMI;
1924 if (!WARN_ON(desc->action == NULL)) {
1925 irq_pm_remove_action(desc, desc->action);
1926 devname = desc->action->name;
1927 unregister_handler_proc(irq, desc->action);
1929 kfree(desc->action);
1930 desc->action = NULL;
1933 irq_settings_clr_disable_unlazy(desc);
1934 irq_shutdown_and_deactivate(desc);
1936 irq_release_resources(desc);
1938 irq_chip_pm_put(&desc->irq_data);
1939 module_put(desc->owner);
1944 const void *free_nmi(unsigned int irq, void *dev_id)
1946 struct irq_desc *desc = irq_to_desc(irq);
1947 unsigned long flags;
1948 const void *devname;
1950 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1953 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1956 /* NMI still enabled */
1957 if (WARN_ON(desc->depth == 0))
1958 disable_nmi_nosync(irq);
1960 raw_spin_lock_irqsave(&desc->lock, flags);
1962 irq_nmi_teardown(desc);
1963 devname = __cleanup_nmi(irq, desc);
1965 raw_spin_unlock_irqrestore(&desc->lock, flags);
1971 * request_threaded_irq - allocate an interrupt line
1972 * @irq: Interrupt line to allocate
1973 * @handler: Function to be called when the IRQ occurs.
1974 * Primary handler for threaded interrupts
1975 * If NULL and thread_fn != NULL the default
1976 * primary handler is installed
1977 * @thread_fn: Function called from the irq handler thread
1978 * If NULL, no irq thread is created
1979 * @irqflags: Interrupt type flags
1980 * @devname: An ascii name for the claiming device
1981 * @dev_id: A cookie passed back to the handler function
1983 * This call allocates interrupt resources and enables the
1984 * interrupt line and IRQ handling. From the point this
1985 * call is made your handler function may be invoked. Since
1986 * your handler function must clear any interrupt the board
1987 * raises, you must take care both to initialise your hardware
1988 * and to set up the interrupt handler in the right order.
1990 * If you want to set up a threaded irq handler for your device
1991 * then you need to supply @handler and @thread_fn. @handler is
1992 * still called in hard interrupt context and has to check
1993 * whether the interrupt originates from the device. If yes it
1994 * needs to disable the interrupt on the device and return
1995 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1996 * @thread_fn. This split handler design is necessary to support
1997 * shared interrupts.
1999 * Dev_id must be globally unique. Normally the address of the
2000 * device data structure is used as the cookie. Since the handler
2001 * receives this value it makes sense to use it.
2003 * If your interrupt is shared you must pass a non NULL dev_id
2004 * as this is required when freeing the interrupt.
2008 * IRQF_SHARED Interrupt is shared
2009 * IRQF_TRIGGER_* Specify active edge(s) or level
2012 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2013 irq_handler_t thread_fn, unsigned long irqflags,
2014 const char *devname, void *dev_id)
2016 struct irqaction *action;
2017 struct irq_desc *desc;
2020 if (irq == IRQ_NOTCONNECTED)
2024 * Sanity-check: shared interrupts must pass in a real dev-ID,
2025 * otherwise we'll have trouble later trying to figure out
2026 * which interrupt is which (messes up the interrupt freeing
2029 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2030 * it cannot be set along with IRQF_NO_SUSPEND.
2032 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2033 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2034 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2037 desc = irq_to_desc(irq);
2041 if (!irq_settings_can_request(desc) ||
2042 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2048 handler = irq_default_primary_handler;
2051 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2055 action->handler = handler;
2056 action->thread_fn = thread_fn;
2057 action->flags = irqflags;
2058 action->name = devname;
2059 action->dev_id = dev_id;
2061 retval = irq_chip_pm_get(&desc->irq_data);
2067 retval = __setup_irq(irq, desc, action);
2070 irq_chip_pm_put(&desc->irq_data);
2071 kfree(action->secondary);
2075 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2076 if (!retval && (irqflags & IRQF_SHARED)) {
2078 * It's a shared IRQ -- the driver ought to be prepared for it
2079 * to happen immediately, so let's make sure....
2080 * We disable the irq to make sure that a 'real' IRQ doesn't
2081 * run in parallel with our fake.
2083 unsigned long flags;
2086 local_irq_save(flags);
2088 handler(irq, dev_id);
2090 local_irq_restore(flags);
2096 EXPORT_SYMBOL(request_threaded_irq);
2099 * request_any_context_irq - allocate an interrupt line
2100 * @irq: Interrupt line to allocate
2101 * @handler: Function to be called when the IRQ occurs.
2102 * Threaded handler for threaded interrupts.
2103 * @flags: Interrupt type flags
2104 * @name: An ascii name for the claiming device
2105 * @dev_id: A cookie passed back to the handler function
2107 * This call allocates interrupt resources and enables the
2108 * interrupt line and IRQ handling. It selects either a
2109 * hardirq or threaded handling method depending on the
2112 * On failure, it returns a negative value. On success,
2113 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2115 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2116 unsigned long flags, const char *name, void *dev_id)
2118 struct irq_desc *desc;
2121 if (irq == IRQ_NOTCONNECTED)
2124 desc = irq_to_desc(irq);
2128 if (irq_settings_is_nested_thread(desc)) {
2129 ret = request_threaded_irq(irq, NULL, handler,
2130 flags, name, dev_id);
2131 return !ret ? IRQC_IS_NESTED : ret;
2134 ret = request_irq(irq, handler, flags, name, dev_id);
2135 return !ret ? IRQC_IS_HARDIRQ : ret;
2137 EXPORT_SYMBOL_GPL(request_any_context_irq);
2140 * request_nmi - allocate an interrupt line for NMI delivery
2141 * @irq: Interrupt line to allocate
2142 * @handler: Function to be called when the IRQ occurs.
2143 * Threaded handler for threaded interrupts.
2144 * @irqflags: Interrupt type flags
2145 * @name: An ascii name for the claiming device
2146 * @dev_id: A cookie passed back to the handler function
2148 * This call allocates interrupt resources and enables the
2149 * interrupt line and IRQ handling. It sets up the IRQ line
2150 * to be handled as an NMI.
2152 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2153 * cannot be threaded.
2155 * Interrupt lines requested for NMI delivering must produce per cpu
2156 * interrupts and have auto enabling setting disabled.
2158 * Dev_id must be globally unique. Normally the address of the
2159 * device data structure is used as the cookie. Since the handler
2160 * receives this value it makes sense to use it.
2162 * If the interrupt line cannot be used to deliver NMIs, function
2163 * will fail and return a negative value.
2165 int request_nmi(unsigned int irq, irq_handler_t handler,
2166 unsigned long irqflags, const char *name, void *dev_id)
2168 struct irqaction *action;
2169 struct irq_desc *desc;
2170 unsigned long flags;
2173 if (irq == IRQ_NOTCONNECTED)
2176 /* NMI cannot be shared, used for Polling */
2177 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2180 if (!(irqflags & IRQF_PERCPU))
2186 desc = irq_to_desc(irq);
2188 if (!desc || irq_settings_can_autoenable(desc) ||
2189 !irq_settings_can_request(desc) ||
2190 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2191 !irq_supports_nmi(desc))
2194 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2198 action->handler = handler;
2199 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2200 action->name = name;
2201 action->dev_id = dev_id;
2203 retval = irq_chip_pm_get(&desc->irq_data);
2207 retval = __setup_irq(irq, desc, action);
2211 raw_spin_lock_irqsave(&desc->lock, flags);
2213 /* Setup NMI state */
2214 desc->istate |= IRQS_NMI;
2215 retval = irq_nmi_setup(desc);
2217 __cleanup_nmi(irq, desc);
2218 raw_spin_unlock_irqrestore(&desc->lock, flags);
2222 raw_spin_unlock_irqrestore(&desc->lock, flags);
2227 irq_chip_pm_put(&desc->irq_data);
2234 void enable_percpu_irq(unsigned int irq, unsigned int type)
2236 unsigned int cpu = smp_processor_id();
2237 unsigned long flags;
2238 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2244 * If the trigger type is not specified by the caller, then
2245 * use the default for this interrupt.
2247 type &= IRQ_TYPE_SENSE_MASK;
2248 if (type == IRQ_TYPE_NONE)
2249 type = irqd_get_trigger_type(&desc->irq_data);
2251 if (type != IRQ_TYPE_NONE) {
2254 ret = __irq_set_trigger(desc, type);
2257 WARN(1, "failed to set type for IRQ%d\n", irq);
2262 irq_percpu_enable(desc, cpu);
2264 irq_put_desc_unlock(desc, flags);
2266 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2268 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2270 enable_percpu_irq(irq, type);
2274 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2275 * @irq: Linux irq number to check for
2277 * Must be called from a non migratable context. Returns the enable
2278 * state of a per cpu interrupt on the current cpu.
2280 bool irq_percpu_is_enabled(unsigned int irq)
2282 unsigned int cpu = smp_processor_id();
2283 struct irq_desc *desc;
2284 unsigned long flags;
2287 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2291 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2292 irq_put_desc_unlock(desc, flags);
2296 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2298 void disable_percpu_irq(unsigned int irq)
2300 unsigned int cpu = smp_processor_id();
2301 unsigned long flags;
2302 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2307 irq_percpu_disable(desc, cpu);
2308 irq_put_desc_unlock(desc, flags);
2310 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2312 void disable_percpu_nmi(unsigned int irq)
2314 disable_percpu_irq(irq);
2318 * Internal function to unregister a percpu irqaction.
2320 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2322 struct irq_desc *desc = irq_to_desc(irq);
2323 struct irqaction *action;
2324 unsigned long flags;
2326 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2331 raw_spin_lock_irqsave(&desc->lock, flags);
2333 action = desc->action;
2334 if (!action || action->percpu_dev_id != dev_id) {
2335 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2339 if (!cpumask_empty(desc->percpu_enabled)) {
2340 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2341 irq, cpumask_first(desc->percpu_enabled));
2345 /* Found it - now remove it from the list of entries: */
2346 desc->action = NULL;
2348 desc->istate &= ~IRQS_NMI;
2350 raw_spin_unlock_irqrestore(&desc->lock, flags);
2352 unregister_handler_proc(irq, action);
2354 irq_chip_pm_put(&desc->irq_data);
2355 module_put(desc->owner);
2359 raw_spin_unlock_irqrestore(&desc->lock, flags);
2364 * remove_percpu_irq - free a per-cpu interrupt
2365 * @irq: Interrupt line to free
2366 * @act: irqaction for the interrupt
2368 * Used to remove interrupts statically setup by the early boot process.
2370 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2372 struct irq_desc *desc = irq_to_desc(irq);
2374 if (desc && irq_settings_is_per_cpu_devid(desc))
2375 __free_percpu_irq(irq, act->percpu_dev_id);
2379 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2380 * @irq: Interrupt line to free
2381 * @dev_id: Device identity to free
2383 * Remove a percpu interrupt handler. The handler is removed, but
2384 * the interrupt line is not disabled. This must be done on each
2385 * CPU before calling this function. The function does not return
2386 * until any executing interrupts for this IRQ have completed.
2388 * This function must not be called from interrupt context.
2390 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2392 struct irq_desc *desc = irq_to_desc(irq);
2394 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2397 chip_bus_lock(desc);
2398 kfree(__free_percpu_irq(irq, dev_id));
2399 chip_bus_sync_unlock(desc);
2401 EXPORT_SYMBOL_GPL(free_percpu_irq);
2403 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2405 struct irq_desc *desc = irq_to_desc(irq);
2407 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2410 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2413 kfree(__free_percpu_irq(irq, dev_id));
2417 * setup_percpu_irq - setup a per-cpu interrupt
2418 * @irq: Interrupt line to setup
2419 * @act: irqaction for the interrupt
2421 * Used to statically setup per-cpu interrupts in the early boot process.
2423 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2425 struct irq_desc *desc = irq_to_desc(irq);
2428 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2431 retval = irq_chip_pm_get(&desc->irq_data);
2435 retval = __setup_irq(irq, desc, act);
2438 irq_chip_pm_put(&desc->irq_data);
2444 * __request_percpu_irq - allocate a percpu interrupt line
2445 * @irq: Interrupt line to allocate
2446 * @handler: Function to be called when the IRQ occurs.
2447 * @flags: Interrupt type flags (IRQF_TIMER only)
2448 * @devname: An ascii name for the claiming device
2449 * @dev_id: A percpu cookie passed back to the handler function
2451 * This call allocates interrupt resources and enables the
2452 * interrupt on the local CPU. If the interrupt is supposed to be
2453 * enabled on other CPUs, it has to be done on each CPU using
2454 * enable_percpu_irq().
2456 * Dev_id must be globally unique. It is a per-cpu variable, and
2457 * the handler gets called with the interrupted CPU's instance of
2460 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2461 unsigned long flags, const char *devname,
2462 void __percpu *dev_id)
2464 struct irqaction *action;
2465 struct irq_desc *desc;
2471 desc = irq_to_desc(irq);
2472 if (!desc || !irq_settings_can_request(desc) ||
2473 !irq_settings_is_per_cpu_devid(desc))
2476 if (flags && flags != IRQF_TIMER)
2479 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2483 action->handler = handler;
2484 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2485 action->name = devname;
2486 action->percpu_dev_id = dev_id;
2488 retval = irq_chip_pm_get(&desc->irq_data);
2494 retval = __setup_irq(irq, desc, action);
2497 irq_chip_pm_put(&desc->irq_data);
2503 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2506 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2507 * @irq: Interrupt line to allocate
2508 * @handler: Function to be called when the IRQ occurs.
2509 * @name: An ascii name for the claiming device
2510 * @dev_id: A percpu cookie passed back to the handler function
2512 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2513 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2514 * being enabled on the same CPU by using enable_percpu_nmi().
2516 * Dev_id must be globally unique. It is a per-cpu variable, and
2517 * the handler gets called with the interrupted CPU's instance of
2520 * Interrupt lines requested for NMI delivering should have auto enabling
2523 * If the interrupt line cannot be used to deliver NMIs, function
2524 * will fail returning a negative value.
2526 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2527 const char *name, void __percpu *dev_id)
2529 struct irqaction *action;
2530 struct irq_desc *desc;
2531 unsigned long flags;
2537 desc = irq_to_desc(irq);
2539 if (!desc || !irq_settings_can_request(desc) ||
2540 !irq_settings_is_per_cpu_devid(desc) ||
2541 irq_settings_can_autoenable(desc) ||
2542 !irq_supports_nmi(desc))
2545 /* The line cannot already be NMI */
2546 if (desc->istate & IRQS_NMI)
2549 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2553 action->handler = handler;
2554 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2556 action->name = name;
2557 action->percpu_dev_id = dev_id;
2559 retval = irq_chip_pm_get(&desc->irq_data);
2563 retval = __setup_irq(irq, desc, action);
2567 raw_spin_lock_irqsave(&desc->lock, flags);
2568 desc->istate |= IRQS_NMI;
2569 raw_spin_unlock_irqrestore(&desc->lock, flags);
2574 irq_chip_pm_put(&desc->irq_data);
2582 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2583 * @irq: Interrupt line to prepare for NMI delivery
2585 * This call prepares an interrupt line to deliver NMI on the current CPU,
2586 * before that interrupt line gets enabled with enable_percpu_nmi().
2588 * As a CPU local operation, this should be called from non-preemptible
2591 * If the interrupt line cannot be used to deliver NMIs, function
2592 * will fail returning a negative value.
2594 int prepare_percpu_nmi(unsigned int irq)
2596 unsigned long flags;
2597 struct irq_desc *desc;
2600 WARN_ON(preemptible());
2602 desc = irq_get_desc_lock(irq, &flags,
2603 IRQ_GET_DESC_CHECK_PERCPU);
2607 if (WARN(!(desc->istate & IRQS_NMI),
2608 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2614 ret = irq_nmi_setup(desc);
2616 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2621 irq_put_desc_unlock(desc, flags);
2626 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2627 * @irq: Interrupt line from which CPU local NMI configuration should be
2630 * This call undoes the setup done by prepare_percpu_nmi().
2632 * IRQ line should not be enabled for the current CPU.
2634 * As a CPU local operation, this should be called from non-preemptible
2637 void teardown_percpu_nmi(unsigned int irq)
2639 unsigned long flags;
2640 struct irq_desc *desc;
2642 WARN_ON(preemptible());
2644 desc = irq_get_desc_lock(irq, &flags,
2645 IRQ_GET_DESC_CHECK_PERCPU);
2649 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2652 irq_nmi_teardown(desc);
2654 irq_put_desc_unlock(desc, flags);
2657 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2660 struct irq_chip *chip;
2664 chip = irq_data_get_irq_chip(data);
2665 if (WARN_ON_ONCE(!chip))
2667 if (chip->irq_get_irqchip_state)
2669 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2670 data = data->parent_data;
2677 err = chip->irq_get_irqchip_state(data, which, state);
2682 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2683 * @irq: Interrupt line that is forwarded to a VM
2684 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2685 * @state: a pointer to a boolean where the state is to be storeed
2687 * This call snapshots the internal irqchip state of an
2688 * interrupt, returning into @state the bit corresponding to
2691 * This function should be called with preemption disabled if the
2692 * interrupt controller has per-cpu registers.
2694 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2697 struct irq_desc *desc;
2698 struct irq_data *data;
2699 unsigned long flags;
2702 desc = irq_get_desc_buslock(irq, &flags, 0);
2706 data = irq_desc_get_irq_data(desc);
2708 err = __irq_get_irqchip_state(data, which, state);
2710 irq_put_desc_busunlock(desc, flags);
2713 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2716 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2717 * @irq: Interrupt line that is forwarded to a VM
2718 * @which: State to be restored (one of IRQCHIP_STATE_*)
2719 * @val: Value corresponding to @which
2721 * This call sets the internal irqchip state of an interrupt,
2722 * depending on the value of @which.
2724 * This function should be called with migration disabled if the
2725 * interrupt controller has per-cpu registers.
2727 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2730 struct irq_desc *desc;
2731 struct irq_data *data;
2732 struct irq_chip *chip;
2733 unsigned long flags;
2736 desc = irq_get_desc_buslock(irq, &flags, 0);
2740 data = irq_desc_get_irq_data(desc);
2743 chip = irq_data_get_irq_chip(data);
2744 if (WARN_ON_ONCE(!chip)) {
2748 if (chip->irq_set_irqchip_state)
2750 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2751 data = data->parent_data;
2758 err = chip->irq_set_irqchip_state(data, which, val);
2761 irq_put_desc_busunlock(desc, flags);
2764 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);