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 DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
30 static int __init setup_forced_irqthreads(char *arg)
32 static_branch_enable(&force_irqthreads_key);
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 affinity 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 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
198 static void irq_validate_effective_affinity(struct irq_data *data)
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);
209 static inline void irq_init_effective_affinity(struct irq_data *data,
210 const struct cpumask *mask)
212 cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
215 static inline void irq_validate_effective_affinity(struct irq_data *data) { }
216 static inline void irq_init_effective_affinity(struct irq_data *data,
217 const struct cpumask *mask) { }
220 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
223 struct irq_desc *desc = irq_data_to_desc(data);
224 struct irq_chip *chip = irq_data_get_irq_chip(data);
227 if (!chip || !chip->irq_set_affinity)
231 * If this is a managed interrupt and housekeeping is enabled on
232 * it check whether the requested affinity mask intersects with
233 * a housekeeping CPU. If so, then remove the isolated CPUs from
234 * the mask and just keep the housekeeping CPU(s). This prevents
235 * the affinity setter from routing the interrupt to an isolated
236 * CPU to avoid that I/O submitted from a housekeeping CPU causes
237 * interrupts on an isolated one.
239 * If the masks do not intersect or include online CPU(s) then
240 * keep the requested mask. The isolated target CPUs are only
241 * receiving interrupts when the I/O operation was submitted
242 * directly from them.
244 * If all housekeeping CPUs in the affinity mask are offline, the
245 * interrupt will be migrated by the CPU hotplug code once a
246 * housekeeping CPU which belongs to the affinity mask comes
249 if (irqd_affinity_is_managed(data) &&
250 housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
251 const struct cpumask *hk_mask, *prog_mask;
253 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
254 static struct cpumask tmp_mask;
256 hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
258 raw_spin_lock(&tmp_mask_lock);
259 cpumask_and(&tmp_mask, mask, hk_mask);
260 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
263 prog_mask = &tmp_mask;
264 ret = chip->irq_set_affinity(data, prog_mask, force);
265 raw_spin_unlock(&tmp_mask_lock);
267 ret = chip->irq_set_affinity(data, mask, force);
270 case IRQ_SET_MASK_OK:
271 case IRQ_SET_MASK_OK_DONE:
272 cpumask_copy(desc->irq_common_data.affinity, mask);
274 case IRQ_SET_MASK_OK_NOCOPY:
275 irq_validate_effective_affinity(data);
276 irq_set_thread_affinity(desc);
283 #ifdef CONFIG_GENERIC_PENDING_IRQ
284 static inline int irq_set_affinity_pending(struct irq_data *data,
285 const struct cpumask *dest)
287 struct irq_desc *desc = irq_data_to_desc(data);
289 irqd_set_move_pending(data);
290 irq_copy_pending(desc, dest);
294 static inline int irq_set_affinity_pending(struct irq_data *data,
295 const struct cpumask *dest)
301 static int irq_try_set_affinity(struct irq_data *data,
302 const struct cpumask *dest, bool force)
304 int ret = irq_do_set_affinity(data, dest, force);
307 * In case that the underlying vector management is busy and the
308 * architecture supports the generic pending mechanism then utilize
309 * this to avoid returning an error to user space.
311 if (ret == -EBUSY && !force)
312 ret = irq_set_affinity_pending(data, dest);
316 static bool irq_set_affinity_deactivated(struct irq_data *data,
317 const struct cpumask *mask, bool force)
319 struct irq_desc *desc = irq_data_to_desc(data);
322 * Handle irq chips which can handle affinity only in activated
325 * If the interrupt is not yet activated, just store the affinity
326 * mask and do not call the chip driver at all. On activation the
327 * driver has to make sure anyway that the interrupt is in a
328 * usable state so startup works.
330 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
331 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
334 cpumask_copy(desc->irq_common_data.affinity, mask);
335 irq_init_effective_affinity(data, mask);
336 irqd_set(data, IRQD_AFFINITY_SET);
340 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
343 struct irq_chip *chip = irq_data_get_irq_chip(data);
344 struct irq_desc *desc = irq_data_to_desc(data);
347 if (!chip || !chip->irq_set_affinity)
350 if (irq_set_affinity_deactivated(data, mask, force))
353 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
354 ret = irq_try_set_affinity(data, mask, force);
356 irqd_set_move_pending(data);
357 irq_copy_pending(desc, mask);
360 if (desc->affinity_notify) {
361 kref_get(&desc->affinity_notify->kref);
362 if (!schedule_work(&desc->affinity_notify->work)) {
363 /* Work was already scheduled, drop our extra ref */
364 kref_put(&desc->affinity_notify->kref,
365 desc->affinity_notify->release);
368 irqd_set(data, IRQD_AFFINITY_SET);
374 * irq_update_affinity_desc - Update affinity management for an interrupt
375 * @irq: The interrupt number to update
376 * @affinity: Pointer to the affinity descriptor
378 * This interface can be used to configure the affinity management of
379 * interrupts which have been allocated already.
381 * There are certain limitations on when it may be used - attempts to use it
382 * for when the kernel is configured for generic IRQ reservation mode (in
383 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
384 * managed/non-managed interrupt accounting. In addition, attempts to use it on
385 * an interrupt which is already started or which has already been configured
386 * as managed will also fail, as these mean invalid init state or double init.
388 int irq_update_affinity_desc(unsigned int irq,
389 struct irq_affinity_desc *affinity)
391 struct irq_desc *desc;
397 * Supporting this with the reservation scheme used by x86 needs
398 * some more thought. Fail it for now.
400 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
403 desc = irq_get_desc_buslock(irq, &flags, 0);
407 /* Requires the interrupt to be shut down */
408 if (irqd_is_started(&desc->irq_data)) {
413 /* Interrupts which are already managed cannot be modified */
414 if (irqd_affinity_is_managed(&desc->irq_data)) {
420 * Deactivate the interrupt. That's required to undo
421 * anything an earlier activation has established.
423 activated = irqd_is_activated(&desc->irq_data);
425 irq_domain_deactivate_irq(&desc->irq_data);
427 if (affinity->is_managed) {
428 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
429 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
432 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
434 /* Restore the activation state */
436 irq_domain_activate_irq(&desc->irq_data, false);
439 irq_put_desc_busunlock(desc, flags);
443 static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
446 struct irq_desc *desc = irq_to_desc(irq);
453 raw_spin_lock_irqsave(&desc->lock, flags);
454 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
455 raw_spin_unlock_irqrestore(&desc->lock, flags);
460 * irq_set_affinity - Set the irq affinity of a given irq
461 * @irq: Interrupt to set affinity
464 * Fails if cpumask does not contain an online CPU
466 int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
468 return __irq_set_affinity(irq, cpumask, false);
470 EXPORT_SYMBOL_GPL(irq_set_affinity);
473 * irq_force_affinity - Force the irq affinity of a given irq
474 * @irq: Interrupt to set affinity
477 * Same as irq_set_affinity, but without checking the mask against
480 * Solely for low level cpu hotplug code, where we need to make per
481 * cpu interrupts affine before the cpu becomes online.
483 int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
485 return __irq_set_affinity(irq, cpumask, true);
487 EXPORT_SYMBOL_GPL(irq_force_affinity);
489 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
492 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
496 desc->affinity_hint = m;
497 irq_put_desc_unlock(desc, flags);
498 /* set the initial affinity to prevent every interrupt being on CPU0 */
500 __irq_set_affinity(irq, m, false);
503 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
505 static void irq_affinity_notify(struct work_struct *work)
507 struct irq_affinity_notify *notify =
508 container_of(work, struct irq_affinity_notify, work);
509 struct irq_desc *desc = irq_to_desc(notify->irq);
510 cpumask_var_t cpumask;
513 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
516 raw_spin_lock_irqsave(&desc->lock, flags);
517 if (irq_move_pending(&desc->irq_data))
518 irq_get_pending(cpumask, desc);
520 cpumask_copy(cpumask, desc->irq_common_data.affinity);
521 raw_spin_unlock_irqrestore(&desc->lock, flags);
523 notify->notify(notify, cpumask);
525 free_cpumask_var(cpumask);
527 kref_put(¬ify->kref, notify->release);
531 * irq_set_affinity_notifier - control notification of IRQ affinity changes
532 * @irq: Interrupt for which to enable/disable notification
533 * @notify: Context for notification, or %NULL to disable
534 * notification. Function pointers must be initialised;
535 * the other fields will be initialised by this function.
537 * Must be called in process context. Notification may only be enabled
538 * after the IRQ is allocated and must be disabled before the IRQ is
539 * freed using free_irq().
542 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
544 struct irq_desc *desc = irq_to_desc(irq);
545 struct irq_affinity_notify *old_notify;
548 /* The release function is promised process context */
551 if (!desc || desc->istate & IRQS_NMI)
554 /* Complete initialisation of *notify */
557 kref_init(¬ify->kref);
558 INIT_WORK(¬ify->work, irq_affinity_notify);
561 raw_spin_lock_irqsave(&desc->lock, flags);
562 old_notify = desc->affinity_notify;
563 desc->affinity_notify = notify;
564 raw_spin_unlock_irqrestore(&desc->lock, flags);
567 if (cancel_work_sync(&old_notify->work)) {
568 /* Pending work had a ref, put that one too */
569 kref_put(&old_notify->kref, old_notify->release);
571 kref_put(&old_notify->kref, old_notify->release);
576 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
578 #ifndef CONFIG_AUTO_IRQ_AFFINITY
580 * Generic version of the affinity autoselector.
582 int irq_setup_affinity(struct irq_desc *desc)
584 struct cpumask *set = irq_default_affinity;
585 int ret, node = irq_desc_get_node(desc);
586 static DEFINE_RAW_SPINLOCK(mask_lock);
587 static struct cpumask mask;
589 /* Excludes PER_CPU and NO_BALANCE interrupts */
590 if (!__irq_can_set_affinity(desc))
593 raw_spin_lock(&mask_lock);
595 * Preserve the managed affinity setting and a userspace affinity
596 * setup, but make sure that one of the targets is online.
598 if (irqd_affinity_is_managed(&desc->irq_data) ||
599 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
600 if (cpumask_intersects(desc->irq_common_data.affinity,
602 set = desc->irq_common_data.affinity;
604 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
607 cpumask_and(&mask, cpu_online_mask, set);
608 if (cpumask_empty(&mask))
609 cpumask_copy(&mask, cpu_online_mask);
611 if (node != NUMA_NO_NODE) {
612 const struct cpumask *nodemask = cpumask_of_node(node);
614 /* make sure at least one of the cpus in nodemask is online */
615 if (cpumask_intersects(&mask, nodemask))
616 cpumask_and(&mask, &mask, nodemask);
618 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
619 raw_spin_unlock(&mask_lock);
623 /* Wrapper for ALPHA specific affinity selector magic */
624 int irq_setup_affinity(struct irq_desc *desc)
626 return irq_select_affinity(irq_desc_get_irq(desc));
628 #endif /* CONFIG_AUTO_IRQ_AFFINITY */
629 #endif /* CONFIG_SMP */
633 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
634 * @irq: interrupt number to set affinity
635 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
636 * specific data for percpu_devid interrupts
638 * This function uses the vCPU specific data to set the vCPU
639 * affinity for an irq. The vCPU specific data is passed from
640 * outside, such as KVM. One example code path is as below:
641 * KVM -> IOMMU -> irq_set_vcpu_affinity().
643 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
646 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
647 struct irq_data *data;
648 struct irq_chip *chip;
654 data = irq_desc_get_irq_data(desc);
656 chip = irq_data_get_irq_chip(data);
657 if (chip && chip->irq_set_vcpu_affinity)
659 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
660 data = data->parent_data;
667 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
668 irq_put_desc_unlock(desc, flags);
672 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
674 void __disable_irq(struct irq_desc *desc)
680 static int __disable_irq_nosync(unsigned int irq)
683 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
688 irq_put_desc_busunlock(desc, flags);
693 * disable_irq_nosync - disable an irq without waiting
694 * @irq: Interrupt to disable
696 * Disable the selected interrupt line. Disables and Enables are
698 * Unlike disable_irq(), this function does not ensure existing
699 * instances of the IRQ handler have completed before returning.
701 * This function may be called from IRQ context.
703 void disable_irq_nosync(unsigned int irq)
705 __disable_irq_nosync(irq);
707 EXPORT_SYMBOL(disable_irq_nosync);
710 * disable_irq - disable an irq and wait for completion
711 * @irq: Interrupt to disable
713 * Disable the selected interrupt line. Enables and Disables are
715 * This function waits for any pending IRQ handlers for this interrupt
716 * to complete before returning. If you use this function while
717 * holding a resource the IRQ handler may need you will deadlock.
719 * This function may be called - with care - from IRQ context.
721 void disable_irq(unsigned int irq)
723 if (!__disable_irq_nosync(irq))
724 synchronize_irq(irq);
726 EXPORT_SYMBOL(disable_irq);
729 * disable_hardirq - disables an irq and waits for hardirq completion
730 * @irq: Interrupt to disable
732 * Disable the selected interrupt line. Enables and Disables are
734 * This function waits for any pending hard IRQ handlers for this
735 * interrupt to complete before returning. If you use this function while
736 * holding a resource the hard IRQ handler may need you will deadlock.
738 * When used to optimistically disable an interrupt from atomic context
739 * the return value must be checked.
741 * Returns: false if a threaded handler is active.
743 * This function may be called - with care - from IRQ context.
745 bool disable_hardirq(unsigned int irq)
747 if (!__disable_irq_nosync(irq))
748 return synchronize_hardirq(irq);
752 EXPORT_SYMBOL_GPL(disable_hardirq);
755 * disable_nmi_nosync - disable an nmi without waiting
756 * @irq: Interrupt to disable
758 * Disable the selected interrupt line. Disables and enables are
760 * The interrupt to disable must have been requested through request_nmi.
761 * Unlike disable_nmi(), this function does not ensure existing
762 * instances of the IRQ handler have completed before returning.
764 void disable_nmi_nosync(unsigned int irq)
766 disable_irq_nosync(irq);
769 void __enable_irq(struct irq_desc *desc)
771 switch (desc->depth) {
774 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
775 irq_desc_get_irq(desc));
778 if (desc->istate & IRQS_SUSPENDED)
780 /* Prevent probing on this irq: */
781 irq_settings_set_noprobe(desc);
783 * Call irq_startup() not irq_enable() here because the
784 * interrupt might be marked NOAUTOEN. So irq_startup()
785 * needs to be invoked when it gets enabled the first
786 * time. If it was already started up, then irq_startup()
787 * will invoke irq_enable() under the hood.
789 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
798 * enable_irq - enable handling of an irq
799 * @irq: Interrupt to enable
801 * Undoes the effect of one call to disable_irq(). If this
802 * matches the last disable, processing of interrupts on this
803 * IRQ line is re-enabled.
805 * This function may be called from IRQ context only when
806 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
808 void enable_irq(unsigned int irq)
811 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
815 if (WARN(!desc->irq_data.chip,
816 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
821 irq_put_desc_busunlock(desc, flags);
823 EXPORT_SYMBOL(enable_irq);
826 * enable_nmi - enable handling of an nmi
827 * @irq: Interrupt to enable
829 * The interrupt to enable must have been requested through request_nmi.
830 * Undoes the effect of one call to disable_nmi(). If this
831 * matches the last disable, processing of interrupts on this
832 * IRQ line is re-enabled.
834 void enable_nmi(unsigned int irq)
839 static int set_irq_wake_real(unsigned int irq, unsigned int on)
841 struct irq_desc *desc = irq_to_desc(irq);
844 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
847 if (desc->irq_data.chip->irq_set_wake)
848 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
854 * irq_set_irq_wake - control irq power management wakeup
855 * @irq: interrupt to control
856 * @on: enable/disable power management wakeup
858 * Enable/disable power management wakeup mode, which is
859 * disabled by default. Enables and disables must match,
860 * just as they match for non-wakeup mode support.
862 * Wakeup mode lets this IRQ wake the system from sleep
863 * states like "suspend to RAM".
865 * Note: irq enable/disable state is completely orthogonal
866 * to the enable/disable state of irq wake. An irq can be
867 * disabled with disable_irq() and still wake the system as
868 * long as the irq has wake enabled. If this does not hold,
869 * then the underlying irq chip and the related driver need
870 * to be investigated.
872 int irq_set_irq_wake(unsigned int irq, unsigned int on)
875 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
881 /* Don't use NMIs as wake up interrupts please */
882 if (desc->istate & IRQS_NMI) {
887 /* wakeup-capable irqs can be shared between drivers that
888 * don't need to have the same sleep mode behaviors.
891 if (desc->wake_depth++ == 0) {
892 ret = set_irq_wake_real(irq, on);
894 desc->wake_depth = 0;
896 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
899 if (desc->wake_depth == 0) {
900 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
901 } else if (--desc->wake_depth == 0) {
902 ret = set_irq_wake_real(irq, on);
904 desc->wake_depth = 1;
906 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
911 irq_put_desc_busunlock(desc, flags);
914 EXPORT_SYMBOL(irq_set_irq_wake);
917 * Internal function that tells the architecture code whether a
918 * particular irq has been exclusively allocated or is available
921 int can_request_irq(unsigned int irq, unsigned long irqflags)
924 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
930 if (irq_settings_can_request(desc)) {
932 irqflags & desc->action->flags & IRQF_SHARED)
935 irq_put_desc_unlock(desc, flags);
939 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
941 struct irq_chip *chip = desc->irq_data.chip;
944 if (!chip || !chip->irq_set_type) {
946 * IRQF_TRIGGER_* but the PIC does not support multiple
949 pr_debug("No set_type function for IRQ %d (%s)\n",
950 irq_desc_get_irq(desc),
951 chip ? (chip->name ? : "unknown") : "unknown");
955 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
956 if (!irqd_irq_masked(&desc->irq_data))
958 if (!irqd_irq_disabled(&desc->irq_data))
962 /* Mask all flags except trigger mode */
963 flags &= IRQ_TYPE_SENSE_MASK;
964 ret = chip->irq_set_type(&desc->irq_data, flags);
967 case IRQ_SET_MASK_OK:
968 case IRQ_SET_MASK_OK_DONE:
969 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
970 irqd_set(&desc->irq_data, flags);
973 case IRQ_SET_MASK_OK_NOCOPY:
974 flags = irqd_get_trigger_type(&desc->irq_data);
975 irq_settings_set_trigger_mask(desc, flags);
976 irqd_clear(&desc->irq_data, IRQD_LEVEL);
977 irq_settings_clr_level(desc);
978 if (flags & IRQ_TYPE_LEVEL_MASK) {
979 irq_settings_set_level(desc);
980 irqd_set(&desc->irq_data, IRQD_LEVEL);
986 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
987 flags, irq_desc_get_irq(desc), chip->irq_set_type);
994 #ifdef CONFIG_HARDIRQS_SW_RESEND
995 int irq_set_parent(int irq, int parent_irq)
998 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1003 desc->parent_irq = parent_irq;
1005 irq_put_desc_unlock(desc, flags);
1008 EXPORT_SYMBOL_GPL(irq_set_parent);
1012 * Default primary interrupt handler for threaded interrupts. Is
1013 * assigned as primary handler when request_threaded_irq is called
1014 * with handler == NULL. Useful for oneshot interrupts.
1016 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1018 return IRQ_WAKE_THREAD;
1022 * Primary handler for nested threaded interrupts. Should never be
1025 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1027 WARN(1, "Primary handler called for nested irq %d\n", irq);
1031 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1033 WARN(1, "Secondary action handler called for irq %d\n", irq);
1037 static int irq_wait_for_interrupt(struct irqaction *action)
1040 set_current_state(TASK_INTERRUPTIBLE);
1042 if (kthread_should_stop()) {
1043 /* may need to run one last time */
1044 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1045 &action->thread_flags)) {
1046 __set_current_state(TASK_RUNNING);
1049 __set_current_state(TASK_RUNNING);
1053 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1054 &action->thread_flags)) {
1055 __set_current_state(TASK_RUNNING);
1063 * Oneshot interrupts keep the irq line masked until the threaded
1064 * handler finished. unmask if the interrupt has not been disabled and
1067 static void irq_finalize_oneshot(struct irq_desc *desc,
1068 struct irqaction *action)
1070 if (!(desc->istate & IRQS_ONESHOT) ||
1071 action->handler == irq_forced_secondary_handler)
1074 chip_bus_lock(desc);
1075 raw_spin_lock_irq(&desc->lock);
1078 * Implausible though it may be we need to protect us against
1079 * the following scenario:
1081 * The thread is faster done than the hard interrupt handler
1082 * on the other CPU. If we unmask the irq line then the
1083 * interrupt can come in again and masks the line, leaves due
1084 * to IRQS_INPROGRESS and the irq line is masked forever.
1086 * This also serializes the state of shared oneshot handlers
1087 * versus "desc->threads_oneshot |= action->thread_mask;" in
1088 * irq_wake_thread(). See the comment there which explains the
1091 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1092 raw_spin_unlock_irq(&desc->lock);
1093 chip_bus_sync_unlock(desc);
1099 * Now check again, whether the thread should run. Otherwise
1100 * we would clear the threads_oneshot bit of this thread which
1103 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1106 desc->threads_oneshot &= ~action->thread_mask;
1108 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1109 irqd_irq_masked(&desc->irq_data))
1110 unmask_threaded_irq(desc);
1113 raw_spin_unlock_irq(&desc->lock);
1114 chip_bus_sync_unlock(desc);
1119 * Check whether we need to change the affinity of the interrupt thread.
1122 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1127 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1131 * In case we are out of memory we set IRQTF_AFFINITY again and
1132 * try again next time
1134 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1135 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1139 raw_spin_lock_irq(&desc->lock);
1141 * This code is triggered unconditionally. Check the affinity
1142 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1144 if (cpumask_available(desc->irq_common_data.affinity)) {
1145 const struct cpumask *m;
1147 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1148 cpumask_copy(mask, m);
1152 raw_spin_unlock_irq(&desc->lock);
1155 set_cpus_allowed_ptr(current, mask);
1156 free_cpumask_var(mask);
1160 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1164 * Interrupts which are not explicitly requested as threaded
1165 * interrupts rely on the implicit bh/preempt disable of the hard irq
1166 * context. So we need to disable bh here to avoid deadlocks and other
1170 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1175 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1176 local_irq_disable();
1177 ret = action->thread_fn(action->irq, action->dev_id);
1178 if (ret == IRQ_HANDLED)
1179 atomic_inc(&desc->threads_handled);
1181 irq_finalize_oneshot(desc, action);
1182 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1189 * Interrupts explicitly requested as threaded interrupts want to be
1190 * preemptible - many of them need to sleep and wait for slow busses to
1193 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1194 struct irqaction *action)
1198 ret = action->thread_fn(action->irq, action->dev_id);
1199 if (ret == IRQ_HANDLED)
1200 atomic_inc(&desc->threads_handled);
1202 irq_finalize_oneshot(desc, action);
1206 static void wake_threads_waitq(struct irq_desc *desc)
1208 if (atomic_dec_and_test(&desc->threads_active))
1209 wake_up(&desc->wait_for_threads);
1212 static void irq_thread_dtor(struct callback_head *unused)
1214 struct task_struct *tsk = current;
1215 struct irq_desc *desc;
1216 struct irqaction *action;
1218 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1221 action = kthread_data(tsk);
1223 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1224 tsk->comm, tsk->pid, action->irq);
1227 desc = irq_to_desc(action->irq);
1229 * If IRQTF_RUNTHREAD is set, we need to decrement
1230 * desc->threads_active and wake possible waiters.
1232 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1233 wake_threads_waitq(desc);
1235 /* Prevent a stale desc->threads_oneshot */
1236 irq_finalize_oneshot(desc, action);
1239 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1241 struct irqaction *secondary = action->secondary;
1243 if (WARN_ON_ONCE(!secondary))
1246 raw_spin_lock_irq(&desc->lock);
1247 __irq_wake_thread(desc, secondary);
1248 raw_spin_unlock_irq(&desc->lock);
1252 * Interrupt handler thread
1254 static int irq_thread(void *data)
1256 struct callback_head on_exit_work;
1257 struct irqaction *action = data;
1258 struct irq_desc *desc = irq_to_desc(action->irq);
1259 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1260 struct irqaction *action);
1262 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1263 &action->thread_flags))
1264 handler_fn = irq_forced_thread_fn;
1266 handler_fn = irq_thread_fn;
1268 init_task_work(&on_exit_work, irq_thread_dtor);
1269 task_work_add(current, &on_exit_work, TWA_NONE);
1271 irq_thread_check_affinity(desc, action);
1273 while (!irq_wait_for_interrupt(action)) {
1274 irqreturn_t action_ret;
1276 irq_thread_check_affinity(desc, action);
1278 action_ret = handler_fn(desc, action);
1279 if (action_ret == IRQ_WAKE_THREAD)
1280 irq_wake_secondary(desc, action);
1282 wake_threads_waitq(desc);
1286 * This is the regular exit path. __free_irq() is stopping the
1287 * thread via kthread_stop() after calling
1288 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1289 * oneshot mask bit can be set.
1291 task_work_cancel(current, irq_thread_dtor);
1296 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1297 * @irq: Interrupt line
1298 * @dev_id: Device identity for which the thread should be woken
1301 void irq_wake_thread(unsigned int irq, void *dev_id)
1303 struct irq_desc *desc = irq_to_desc(irq);
1304 struct irqaction *action;
1305 unsigned long flags;
1307 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1310 raw_spin_lock_irqsave(&desc->lock, flags);
1311 for_each_action_of_desc(desc, action) {
1312 if (action->dev_id == dev_id) {
1314 __irq_wake_thread(desc, action);
1318 raw_spin_unlock_irqrestore(&desc->lock, flags);
1320 EXPORT_SYMBOL_GPL(irq_wake_thread);
1322 static int irq_setup_forced_threading(struct irqaction *new)
1324 if (!force_irqthreads())
1326 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1330 * No further action required for interrupts which are requested as
1331 * threaded interrupts already
1333 if (new->handler == irq_default_primary_handler)
1336 new->flags |= IRQF_ONESHOT;
1339 * Handle the case where we have a real primary handler and a
1340 * thread handler. We force thread them as well by creating a
1343 if (new->handler && new->thread_fn) {
1344 /* Allocate the secondary action */
1345 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1346 if (!new->secondary)
1348 new->secondary->handler = irq_forced_secondary_handler;
1349 new->secondary->thread_fn = new->thread_fn;
1350 new->secondary->dev_id = new->dev_id;
1351 new->secondary->irq = new->irq;
1352 new->secondary->name = new->name;
1354 /* Deal with the primary handler */
1355 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1356 new->thread_fn = new->handler;
1357 new->handler = irq_default_primary_handler;
1361 static int irq_request_resources(struct irq_desc *desc)
1363 struct irq_data *d = &desc->irq_data;
1364 struct irq_chip *c = d->chip;
1366 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1369 static void irq_release_resources(struct irq_desc *desc)
1371 struct irq_data *d = &desc->irq_data;
1372 struct irq_chip *c = d->chip;
1374 if (c->irq_release_resources)
1375 c->irq_release_resources(d);
1378 static bool irq_supports_nmi(struct irq_desc *desc)
1380 struct irq_data *d = irq_desc_get_irq_data(desc);
1382 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1383 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1387 /* Don't support NMIs for chips behind a slow bus */
1388 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1391 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1394 static int irq_nmi_setup(struct irq_desc *desc)
1396 struct irq_data *d = irq_desc_get_irq_data(desc);
1397 struct irq_chip *c = d->chip;
1399 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1402 static void irq_nmi_teardown(struct irq_desc *desc)
1404 struct irq_data *d = irq_desc_get_irq_data(desc);
1405 struct irq_chip *c = d->chip;
1407 if (c->irq_nmi_teardown)
1408 c->irq_nmi_teardown(d);
1412 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1414 struct task_struct *t;
1417 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1420 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1430 * We keep the reference to the task struct even if
1431 * the thread dies to avoid that the interrupt code
1432 * references an already freed task_struct.
1434 new->thread = get_task_struct(t);
1436 * Tell the thread to set its affinity. This is
1437 * important for shared interrupt handlers as we do
1438 * not invoke setup_affinity() for the secondary
1439 * handlers as everything is already set up. Even for
1440 * interrupts marked with IRQF_NO_BALANCE this is
1441 * correct as we want the thread to move to the cpu(s)
1442 * on which the requesting code placed the interrupt.
1444 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1449 * Internal function to register an irqaction - typically used to
1450 * allocate special interrupts that are part of the architecture.
1454 * desc->request_mutex Provides serialization against a concurrent free_irq()
1455 * chip_bus_lock Provides serialization for slow bus operations
1456 * desc->lock Provides serialization against hard interrupts
1458 * chip_bus_lock and desc->lock are sufficient for all other management and
1459 * interrupt related functions. desc->request_mutex solely serializes
1460 * request/free_irq().
1463 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1465 struct irqaction *old, **old_ptr;
1466 unsigned long flags, thread_mask = 0;
1467 int ret, nested, shared = 0;
1472 if (desc->irq_data.chip == &no_irq_chip)
1474 if (!try_module_get(desc->owner))
1480 * If the trigger type is not specified by the caller,
1481 * then use the default for this interrupt.
1483 if (!(new->flags & IRQF_TRIGGER_MASK))
1484 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1487 * Check whether the interrupt nests into another interrupt
1490 nested = irq_settings_is_nested_thread(desc);
1492 if (!new->thread_fn) {
1497 * Replace the primary handler which was provided from
1498 * the driver for non nested interrupt handling by the
1499 * dummy function which warns when called.
1501 new->handler = irq_nested_primary_handler;
1503 if (irq_settings_can_thread(desc)) {
1504 ret = irq_setup_forced_threading(new);
1511 * Create a handler thread when a thread function is supplied
1512 * and the interrupt does not nest into another interrupt
1515 if (new->thread_fn && !nested) {
1516 ret = setup_irq_thread(new, irq, false);
1519 if (new->secondary) {
1520 ret = setup_irq_thread(new->secondary, irq, true);
1527 * Drivers are often written to work w/o knowledge about the
1528 * underlying irq chip implementation, so a request for a
1529 * threaded irq without a primary hard irq context handler
1530 * requires the ONESHOT flag to be set. Some irq chips like
1531 * MSI based interrupts are per se one shot safe. Check the
1532 * chip flags, so we can avoid the unmask dance at the end of
1533 * the threaded handler for those.
1535 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1536 new->flags &= ~IRQF_ONESHOT;
1539 * Protects against a concurrent __free_irq() call which might wait
1540 * for synchronize_hardirq() to complete without holding the optional
1541 * chip bus lock and desc->lock. Also protects against handing out
1542 * a recycled oneshot thread_mask bit while it's still in use by
1543 * its previous owner.
1545 mutex_lock(&desc->request_mutex);
1548 * Acquire bus lock as the irq_request_resources() callback below
1549 * might rely on the serialization or the magic power management
1550 * functions which are abusing the irq_bus_lock() callback,
1552 chip_bus_lock(desc);
1554 /* First installed action requests resources. */
1555 if (!desc->action) {
1556 ret = irq_request_resources(desc);
1558 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1559 new->name, irq, desc->irq_data.chip->name);
1560 goto out_bus_unlock;
1565 * The following block of code has to be executed atomically
1566 * protected against a concurrent interrupt and any of the other
1567 * management calls which are not serialized via
1568 * desc->request_mutex or the optional bus lock.
1570 raw_spin_lock_irqsave(&desc->lock, flags);
1571 old_ptr = &desc->action;
1575 * Can't share interrupts unless both agree to and are
1576 * the same type (level, edge, polarity). So both flag
1577 * fields must have IRQF_SHARED set and the bits which
1578 * set the trigger type must match. Also all must
1580 * Interrupt lines used for NMIs cannot be shared.
1582 unsigned int oldtype;
1584 if (desc->istate & IRQS_NMI) {
1585 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1586 new->name, irq, desc->irq_data.chip->name);
1592 * If nobody did set the configuration before, inherit
1593 * the one provided by the requester.
1595 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1596 oldtype = irqd_get_trigger_type(&desc->irq_data);
1598 oldtype = new->flags & IRQF_TRIGGER_MASK;
1599 irqd_set_trigger_type(&desc->irq_data, oldtype);
1602 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1603 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1604 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1607 /* All handlers must agree on per-cpuness */
1608 if ((old->flags & IRQF_PERCPU) !=
1609 (new->flags & IRQF_PERCPU))
1612 /* add new interrupt at end of irq queue */
1615 * Or all existing action->thread_mask bits,
1616 * so we can find the next zero bit for this
1619 thread_mask |= old->thread_mask;
1620 old_ptr = &old->next;
1627 * Setup the thread mask for this irqaction for ONESHOT. For
1628 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1629 * conditional in irq_wake_thread().
1631 if (new->flags & IRQF_ONESHOT) {
1633 * Unlikely to have 32 resp 64 irqs sharing one line,
1636 if (thread_mask == ~0UL) {
1641 * The thread_mask for the action is or'ed to
1642 * desc->thread_active to indicate that the
1643 * IRQF_ONESHOT thread handler has been woken, but not
1644 * yet finished. The bit is cleared when a thread
1645 * completes. When all threads of a shared interrupt
1646 * line have completed desc->threads_active becomes
1647 * zero and the interrupt line is unmasked. See
1648 * handle.c:irq_wake_thread() for further information.
1650 * If no thread is woken by primary (hard irq context)
1651 * interrupt handlers, then desc->threads_active is
1652 * also checked for zero to unmask the irq line in the
1653 * affected hard irq flow handlers
1654 * (handle_[fasteoi|level]_irq).
1656 * The new action gets the first zero bit of
1657 * thread_mask assigned. See the loop above which or's
1658 * all existing action->thread_mask bits.
1660 new->thread_mask = 1UL << ffz(thread_mask);
1662 } else if (new->handler == irq_default_primary_handler &&
1663 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1665 * The interrupt was requested with handler = NULL, so
1666 * we use the default primary handler for it. But it
1667 * does not have the oneshot flag set. In combination
1668 * with level interrupts this is deadly, because the
1669 * default primary handler just wakes the thread, then
1670 * the irq lines is reenabled, but the device still
1671 * has the level irq asserted. Rinse and repeat....
1673 * While this works for edge type interrupts, we play
1674 * it safe and reject unconditionally because we can't
1675 * say for sure which type this interrupt really
1676 * has. The type flags are unreliable as the
1677 * underlying chip implementation can override them.
1679 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1686 init_waitqueue_head(&desc->wait_for_threads);
1688 /* Setup the type (level, edge polarity) if configured: */
1689 if (new->flags & IRQF_TRIGGER_MASK) {
1690 ret = __irq_set_trigger(desc,
1691 new->flags & IRQF_TRIGGER_MASK);
1698 * Activate the interrupt. That activation must happen
1699 * independently of IRQ_NOAUTOEN. request_irq() can fail
1700 * and the callers are supposed to handle
1701 * that. enable_irq() of an interrupt requested with
1702 * IRQ_NOAUTOEN is not supposed to fail. The activation
1703 * keeps it in shutdown mode, it merily associates
1704 * resources if necessary and if that's not possible it
1705 * fails. Interrupts which are in managed shutdown mode
1706 * will simply ignore that activation request.
1708 ret = irq_activate(desc);
1712 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1713 IRQS_ONESHOT | IRQS_WAITING);
1714 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1716 if (new->flags & IRQF_PERCPU) {
1717 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1718 irq_settings_set_per_cpu(desc);
1719 if (new->flags & IRQF_NO_DEBUG)
1720 irq_settings_set_no_debug(desc);
1724 irq_settings_set_no_debug(desc);
1726 if (new->flags & IRQF_ONESHOT)
1727 desc->istate |= IRQS_ONESHOT;
1729 /* Exclude IRQ from balancing if requested */
1730 if (new->flags & IRQF_NOBALANCING) {
1731 irq_settings_set_no_balancing(desc);
1732 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1735 if (!(new->flags & IRQF_NO_AUTOEN) &&
1736 irq_settings_can_autoenable(desc)) {
1737 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1740 * Shared interrupts do not go well with disabling
1741 * auto enable. The sharing interrupt might request
1742 * it while it's still disabled and then wait for
1743 * interrupts forever.
1745 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1746 /* Undo nested disables: */
1750 } else if (new->flags & IRQF_TRIGGER_MASK) {
1751 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1752 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1755 /* hope the handler works with current trigger mode */
1756 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1762 irq_pm_install_action(desc, new);
1764 /* Reset broken irq detection when installing new handler */
1765 desc->irq_count = 0;
1766 desc->irqs_unhandled = 0;
1769 * Check whether we disabled the irq via the spurious handler
1770 * before. Reenable it and give it another chance.
1772 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1773 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1777 raw_spin_unlock_irqrestore(&desc->lock, flags);
1778 chip_bus_sync_unlock(desc);
1779 mutex_unlock(&desc->request_mutex);
1781 irq_setup_timings(desc, new);
1784 * Strictly no need to wake it up, but hung_task complains
1785 * when no hard interrupt wakes the thread up.
1788 wake_up_process(new->thread);
1790 wake_up_process(new->secondary->thread);
1792 register_irq_proc(irq, desc);
1794 register_handler_proc(irq, new);
1798 if (!(new->flags & IRQF_PROBE_SHARED)) {
1799 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1800 irq, new->flags, new->name, old->flags, old->name);
1801 #ifdef CONFIG_DEBUG_SHIRQ
1808 raw_spin_unlock_irqrestore(&desc->lock, flags);
1811 irq_release_resources(desc);
1813 chip_bus_sync_unlock(desc);
1814 mutex_unlock(&desc->request_mutex);
1818 struct task_struct *t = new->thread;
1824 if (new->secondary && new->secondary->thread) {
1825 struct task_struct *t = new->secondary->thread;
1827 new->secondary->thread = NULL;
1832 module_put(desc->owner);
1837 * Internal function to unregister an irqaction - used to free
1838 * regular and special interrupts that are part of the architecture.
1840 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1842 unsigned irq = desc->irq_data.irq;
1843 struct irqaction *action, **action_ptr;
1844 unsigned long flags;
1846 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1848 mutex_lock(&desc->request_mutex);
1849 chip_bus_lock(desc);
1850 raw_spin_lock_irqsave(&desc->lock, flags);
1853 * There can be multiple actions per IRQ descriptor, find the right
1854 * one based on the dev_id:
1856 action_ptr = &desc->action;
1858 action = *action_ptr;
1861 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1862 raw_spin_unlock_irqrestore(&desc->lock, flags);
1863 chip_bus_sync_unlock(desc);
1864 mutex_unlock(&desc->request_mutex);
1868 if (action->dev_id == dev_id)
1870 action_ptr = &action->next;
1873 /* Found it - now remove it from the list of entries: */
1874 *action_ptr = action->next;
1876 irq_pm_remove_action(desc, action);
1878 /* If this was the last handler, shut down the IRQ line: */
1879 if (!desc->action) {
1880 irq_settings_clr_disable_unlazy(desc);
1881 /* Only shutdown. Deactivate after synchronize_hardirq() */
1886 /* make sure affinity_hint is cleaned up */
1887 if (WARN_ON_ONCE(desc->affinity_hint))
1888 desc->affinity_hint = NULL;
1891 raw_spin_unlock_irqrestore(&desc->lock, flags);
1893 * Drop bus_lock here so the changes which were done in the chip
1894 * callbacks above are synced out to the irq chips which hang
1895 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1897 * Aside of that the bus_lock can also be taken from the threaded
1898 * handler in irq_finalize_oneshot() which results in a deadlock
1899 * because kthread_stop() would wait forever for the thread to
1900 * complete, which is blocked on the bus lock.
1902 * The still held desc->request_mutex() protects against a
1903 * concurrent request_irq() of this irq so the release of resources
1904 * and timing data is properly serialized.
1906 chip_bus_sync_unlock(desc);
1908 unregister_handler_proc(irq, action);
1911 * Make sure it's not being used on another CPU and if the chip
1912 * supports it also make sure that there is no (not yet serviced)
1913 * interrupt in flight at the hardware level.
1915 __synchronize_hardirq(desc, true);
1917 #ifdef CONFIG_DEBUG_SHIRQ
1919 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1920 * event to happen even now it's being freed, so let's make sure that
1921 * is so by doing an extra call to the handler ....
1923 * ( We do this after actually deregistering it, to make sure that a
1924 * 'real' IRQ doesn't run in parallel with our fake. )
1926 if (action->flags & IRQF_SHARED) {
1927 local_irq_save(flags);
1928 action->handler(irq, dev_id);
1929 local_irq_restore(flags);
1934 * The action has already been removed above, but the thread writes
1935 * its oneshot mask bit when it completes. Though request_mutex is
1936 * held across this which prevents __setup_irq() from handing out
1937 * the same bit to a newly requested action.
1939 if (action->thread) {
1940 kthread_stop(action->thread);
1941 put_task_struct(action->thread);
1942 if (action->secondary && action->secondary->thread) {
1943 kthread_stop(action->secondary->thread);
1944 put_task_struct(action->secondary->thread);
1948 /* Last action releases resources */
1949 if (!desc->action) {
1951 * Reacquire bus lock as irq_release_resources() might
1952 * require it to deallocate resources over the slow bus.
1954 chip_bus_lock(desc);
1956 * There is no interrupt on the fly anymore. Deactivate it
1959 raw_spin_lock_irqsave(&desc->lock, flags);
1960 irq_domain_deactivate_irq(&desc->irq_data);
1961 raw_spin_unlock_irqrestore(&desc->lock, flags);
1963 irq_release_resources(desc);
1964 chip_bus_sync_unlock(desc);
1965 irq_remove_timings(desc);
1968 mutex_unlock(&desc->request_mutex);
1970 irq_chip_pm_put(&desc->irq_data);
1971 module_put(desc->owner);
1972 kfree(action->secondary);
1977 * free_irq - free an interrupt allocated with request_irq
1978 * @irq: Interrupt line to free
1979 * @dev_id: Device identity to free
1981 * Remove an interrupt handler. The handler is removed and if the
1982 * interrupt line is no longer in use by any driver it is disabled.
1983 * On a shared IRQ the caller must ensure the interrupt is disabled
1984 * on the card it drives before calling this function. The function
1985 * does not return until any executing interrupts for this IRQ
1988 * This function must not be called from interrupt context.
1990 * Returns the devname argument passed to request_irq.
1992 const void *free_irq(unsigned int irq, void *dev_id)
1994 struct irq_desc *desc = irq_to_desc(irq);
1995 struct irqaction *action;
1996 const char *devname;
1998 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2002 if (WARN_ON(desc->affinity_notify))
2003 desc->affinity_notify = NULL;
2006 action = __free_irq(desc, dev_id);
2011 devname = action->name;
2015 EXPORT_SYMBOL(free_irq);
2017 /* This function must be called with desc->lock held */
2018 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2020 const char *devname = NULL;
2022 desc->istate &= ~IRQS_NMI;
2024 if (!WARN_ON(desc->action == NULL)) {
2025 irq_pm_remove_action(desc, desc->action);
2026 devname = desc->action->name;
2027 unregister_handler_proc(irq, desc->action);
2029 kfree(desc->action);
2030 desc->action = NULL;
2033 irq_settings_clr_disable_unlazy(desc);
2034 irq_shutdown_and_deactivate(desc);
2036 irq_release_resources(desc);
2038 irq_chip_pm_put(&desc->irq_data);
2039 module_put(desc->owner);
2044 const void *free_nmi(unsigned int irq, void *dev_id)
2046 struct irq_desc *desc = irq_to_desc(irq);
2047 unsigned long flags;
2048 const void *devname;
2050 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2053 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2056 /* NMI still enabled */
2057 if (WARN_ON(desc->depth == 0))
2058 disable_nmi_nosync(irq);
2060 raw_spin_lock_irqsave(&desc->lock, flags);
2062 irq_nmi_teardown(desc);
2063 devname = __cleanup_nmi(irq, desc);
2065 raw_spin_unlock_irqrestore(&desc->lock, flags);
2071 * request_threaded_irq - allocate an interrupt line
2072 * @irq: Interrupt line to allocate
2073 * @handler: Function to be called when the IRQ occurs.
2074 * Primary handler for threaded interrupts.
2075 * If handler is NULL and thread_fn != NULL
2076 * the default primary handler is installed.
2077 * @thread_fn: Function called from the irq handler thread
2078 * If NULL, no irq thread is created
2079 * @irqflags: Interrupt type flags
2080 * @devname: An ascii name for the claiming device
2081 * @dev_id: A cookie passed back to the handler function
2083 * This call allocates interrupt resources and enables the
2084 * interrupt line and IRQ handling. From the point this
2085 * call is made your handler function may be invoked. Since
2086 * your handler function must clear any interrupt the board
2087 * raises, you must take care both to initialise your hardware
2088 * and to set up the interrupt handler in the right order.
2090 * If you want to set up a threaded irq handler for your device
2091 * then you need to supply @handler and @thread_fn. @handler is
2092 * still called in hard interrupt context and has to check
2093 * whether the interrupt originates from the device. If yes it
2094 * needs to disable the interrupt on the device and return
2095 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2096 * @thread_fn. This split handler design is necessary to support
2097 * shared interrupts.
2099 * Dev_id must be globally unique. Normally the address of the
2100 * device data structure is used as the cookie. Since the handler
2101 * receives this value it makes sense to use it.
2103 * If your interrupt is shared you must pass a non NULL dev_id
2104 * as this is required when freeing the interrupt.
2108 * IRQF_SHARED Interrupt is shared
2109 * IRQF_TRIGGER_* Specify active edge(s) or level
2110 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2112 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2113 irq_handler_t thread_fn, unsigned long irqflags,
2114 const char *devname, void *dev_id)
2116 struct irqaction *action;
2117 struct irq_desc *desc;
2120 if (irq == IRQ_NOTCONNECTED)
2124 * Sanity-check: shared interrupts must pass in a real dev-ID,
2125 * otherwise we'll have trouble later trying to figure out
2126 * which interrupt is which (messes up the interrupt freeing
2129 * Also shared interrupts do not go well with disabling auto enable.
2130 * The sharing interrupt might request it while it's still disabled
2131 * and then wait for interrupts forever.
2133 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2134 * it cannot be set along with IRQF_NO_SUSPEND.
2136 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2137 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2138 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2139 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2142 desc = irq_to_desc(irq);
2146 if (!irq_settings_can_request(desc) ||
2147 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2153 handler = irq_default_primary_handler;
2156 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2160 action->handler = handler;
2161 action->thread_fn = thread_fn;
2162 action->flags = irqflags;
2163 action->name = devname;
2164 action->dev_id = dev_id;
2166 retval = irq_chip_pm_get(&desc->irq_data);
2172 retval = __setup_irq(irq, desc, action);
2175 irq_chip_pm_put(&desc->irq_data);
2176 kfree(action->secondary);
2180 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2181 if (!retval && (irqflags & IRQF_SHARED)) {
2183 * It's a shared IRQ -- the driver ought to be prepared for it
2184 * to happen immediately, so let's make sure....
2185 * We disable the irq to make sure that a 'real' IRQ doesn't
2186 * run in parallel with our fake.
2188 unsigned long flags;
2191 local_irq_save(flags);
2193 handler(irq, dev_id);
2195 local_irq_restore(flags);
2201 EXPORT_SYMBOL(request_threaded_irq);
2204 * request_any_context_irq - allocate an interrupt line
2205 * @irq: Interrupt line to allocate
2206 * @handler: Function to be called when the IRQ occurs.
2207 * Threaded handler for threaded interrupts.
2208 * @flags: Interrupt type flags
2209 * @name: An ascii name for the claiming device
2210 * @dev_id: A cookie passed back to the handler function
2212 * This call allocates interrupt resources and enables the
2213 * interrupt line and IRQ handling. It selects either a
2214 * hardirq or threaded handling method depending on the
2217 * On failure, it returns a negative value. On success,
2218 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2220 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2221 unsigned long flags, const char *name, void *dev_id)
2223 struct irq_desc *desc;
2226 if (irq == IRQ_NOTCONNECTED)
2229 desc = irq_to_desc(irq);
2233 if (irq_settings_is_nested_thread(desc)) {
2234 ret = request_threaded_irq(irq, NULL, handler,
2235 flags, name, dev_id);
2236 return !ret ? IRQC_IS_NESTED : ret;
2239 ret = request_irq(irq, handler, flags, name, dev_id);
2240 return !ret ? IRQC_IS_HARDIRQ : ret;
2242 EXPORT_SYMBOL_GPL(request_any_context_irq);
2245 * request_nmi - allocate an interrupt line for NMI delivery
2246 * @irq: Interrupt line to allocate
2247 * @handler: Function to be called when the IRQ occurs.
2248 * Threaded handler for threaded interrupts.
2249 * @irqflags: Interrupt type flags
2250 * @name: An ascii name for the claiming device
2251 * @dev_id: A cookie passed back to the handler function
2253 * This call allocates interrupt resources and enables the
2254 * interrupt line and IRQ handling. It sets up the IRQ line
2255 * to be handled as an NMI.
2257 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2258 * cannot be threaded.
2260 * Interrupt lines requested for NMI delivering must produce per cpu
2261 * interrupts and have auto enabling setting disabled.
2263 * Dev_id must be globally unique. Normally the address of the
2264 * device data structure is used as the cookie. Since the handler
2265 * receives this value it makes sense to use it.
2267 * If the interrupt line cannot be used to deliver NMIs, function
2268 * will fail and return a negative value.
2270 int request_nmi(unsigned int irq, irq_handler_t handler,
2271 unsigned long irqflags, const char *name, void *dev_id)
2273 struct irqaction *action;
2274 struct irq_desc *desc;
2275 unsigned long flags;
2278 if (irq == IRQ_NOTCONNECTED)
2281 /* NMI cannot be shared, used for Polling */
2282 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2285 if (!(irqflags & IRQF_PERCPU))
2291 desc = irq_to_desc(irq);
2293 if (!desc || (irq_settings_can_autoenable(desc) &&
2294 !(irqflags & IRQF_NO_AUTOEN)) ||
2295 !irq_settings_can_request(desc) ||
2296 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2297 !irq_supports_nmi(desc))
2300 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2304 action->handler = handler;
2305 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2306 action->name = name;
2307 action->dev_id = dev_id;
2309 retval = irq_chip_pm_get(&desc->irq_data);
2313 retval = __setup_irq(irq, desc, action);
2317 raw_spin_lock_irqsave(&desc->lock, flags);
2319 /* Setup NMI state */
2320 desc->istate |= IRQS_NMI;
2321 retval = irq_nmi_setup(desc);
2323 __cleanup_nmi(irq, desc);
2324 raw_spin_unlock_irqrestore(&desc->lock, flags);
2328 raw_spin_unlock_irqrestore(&desc->lock, flags);
2333 irq_chip_pm_put(&desc->irq_data);
2340 void enable_percpu_irq(unsigned int irq, unsigned int type)
2342 unsigned int cpu = smp_processor_id();
2343 unsigned long flags;
2344 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2350 * If the trigger type is not specified by the caller, then
2351 * use the default for this interrupt.
2353 type &= IRQ_TYPE_SENSE_MASK;
2354 if (type == IRQ_TYPE_NONE)
2355 type = irqd_get_trigger_type(&desc->irq_data);
2357 if (type != IRQ_TYPE_NONE) {
2360 ret = __irq_set_trigger(desc, type);
2363 WARN(1, "failed to set type for IRQ%d\n", irq);
2368 irq_percpu_enable(desc, cpu);
2370 irq_put_desc_unlock(desc, flags);
2372 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2374 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2376 enable_percpu_irq(irq, type);
2380 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2381 * @irq: Linux irq number to check for
2383 * Must be called from a non migratable context. Returns the enable
2384 * state of a per cpu interrupt on the current cpu.
2386 bool irq_percpu_is_enabled(unsigned int irq)
2388 unsigned int cpu = smp_processor_id();
2389 struct irq_desc *desc;
2390 unsigned long flags;
2393 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2397 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2398 irq_put_desc_unlock(desc, flags);
2402 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2404 void disable_percpu_irq(unsigned int irq)
2406 unsigned int cpu = smp_processor_id();
2407 unsigned long flags;
2408 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2413 irq_percpu_disable(desc, cpu);
2414 irq_put_desc_unlock(desc, flags);
2416 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2418 void disable_percpu_nmi(unsigned int irq)
2420 disable_percpu_irq(irq);
2424 * Internal function to unregister a percpu irqaction.
2426 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2428 struct irq_desc *desc = irq_to_desc(irq);
2429 struct irqaction *action;
2430 unsigned long flags;
2432 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2437 raw_spin_lock_irqsave(&desc->lock, flags);
2439 action = desc->action;
2440 if (!action || action->percpu_dev_id != dev_id) {
2441 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2445 if (!cpumask_empty(desc->percpu_enabled)) {
2446 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2447 irq, cpumask_first(desc->percpu_enabled));
2451 /* Found it - now remove it from the list of entries: */
2452 desc->action = NULL;
2454 desc->istate &= ~IRQS_NMI;
2456 raw_spin_unlock_irqrestore(&desc->lock, flags);
2458 unregister_handler_proc(irq, action);
2460 irq_chip_pm_put(&desc->irq_data);
2461 module_put(desc->owner);
2465 raw_spin_unlock_irqrestore(&desc->lock, flags);
2470 * remove_percpu_irq - free a per-cpu interrupt
2471 * @irq: Interrupt line to free
2472 * @act: irqaction for the interrupt
2474 * Used to remove interrupts statically setup by the early boot process.
2476 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2478 struct irq_desc *desc = irq_to_desc(irq);
2480 if (desc && irq_settings_is_per_cpu_devid(desc))
2481 __free_percpu_irq(irq, act->percpu_dev_id);
2485 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2486 * @irq: Interrupt line to free
2487 * @dev_id: Device identity to free
2489 * Remove a percpu interrupt handler. The handler is removed, but
2490 * the interrupt line is not disabled. This must be done on each
2491 * CPU before calling this function. The function does not return
2492 * until any executing interrupts for this IRQ have completed.
2494 * This function must not be called from interrupt context.
2496 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2498 struct irq_desc *desc = irq_to_desc(irq);
2500 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2503 chip_bus_lock(desc);
2504 kfree(__free_percpu_irq(irq, dev_id));
2505 chip_bus_sync_unlock(desc);
2507 EXPORT_SYMBOL_GPL(free_percpu_irq);
2509 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2511 struct irq_desc *desc = irq_to_desc(irq);
2513 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2516 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2519 kfree(__free_percpu_irq(irq, dev_id));
2523 * setup_percpu_irq - setup a per-cpu interrupt
2524 * @irq: Interrupt line to setup
2525 * @act: irqaction for the interrupt
2527 * Used to statically setup per-cpu interrupts in the early boot process.
2529 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2531 struct irq_desc *desc = irq_to_desc(irq);
2534 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2537 retval = irq_chip_pm_get(&desc->irq_data);
2541 retval = __setup_irq(irq, desc, act);
2544 irq_chip_pm_put(&desc->irq_data);
2550 * __request_percpu_irq - allocate a percpu interrupt line
2551 * @irq: Interrupt line to allocate
2552 * @handler: Function to be called when the IRQ occurs.
2553 * @flags: Interrupt type flags (IRQF_TIMER only)
2554 * @devname: An ascii name for the claiming device
2555 * @dev_id: A percpu cookie passed back to the handler function
2557 * This call allocates interrupt resources and enables the
2558 * interrupt on the local CPU. If the interrupt is supposed to be
2559 * enabled on other CPUs, it has to be done on each CPU using
2560 * enable_percpu_irq().
2562 * Dev_id must be globally unique. It is a per-cpu variable, and
2563 * the handler gets called with the interrupted CPU's instance of
2566 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2567 unsigned long flags, const char *devname,
2568 void __percpu *dev_id)
2570 struct irqaction *action;
2571 struct irq_desc *desc;
2577 desc = irq_to_desc(irq);
2578 if (!desc || !irq_settings_can_request(desc) ||
2579 !irq_settings_is_per_cpu_devid(desc))
2582 if (flags && flags != IRQF_TIMER)
2585 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2589 action->handler = handler;
2590 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2591 action->name = devname;
2592 action->percpu_dev_id = dev_id;
2594 retval = irq_chip_pm_get(&desc->irq_data);
2600 retval = __setup_irq(irq, desc, action);
2603 irq_chip_pm_put(&desc->irq_data);
2609 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2612 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2613 * @irq: Interrupt line to allocate
2614 * @handler: Function to be called when the IRQ occurs.
2615 * @name: An ascii name for the claiming device
2616 * @dev_id: A percpu cookie passed back to the handler function
2618 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2619 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2620 * being enabled on the same CPU by using enable_percpu_nmi().
2622 * Dev_id must be globally unique. It is a per-cpu variable, and
2623 * the handler gets called with the interrupted CPU's instance of
2626 * Interrupt lines requested for NMI delivering should have auto enabling
2629 * If the interrupt line cannot be used to deliver NMIs, function
2630 * will fail returning a negative value.
2632 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2633 const char *name, void __percpu *dev_id)
2635 struct irqaction *action;
2636 struct irq_desc *desc;
2637 unsigned long flags;
2643 desc = irq_to_desc(irq);
2645 if (!desc || !irq_settings_can_request(desc) ||
2646 !irq_settings_is_per_cpu_devid(desc) ||
2647 irq_settings_can_autoenable(desc) ||
2648 !irq_supports_nmi(desc))
2651 /* The line cannot already be NMI */
2652 if (desc->istate & IRQS_NMI)
2655 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2659 action->handler = handler;
2660 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2662 action->name = name;
2663 action->percpu_dev_id = dev_id;
2665 retval = irq_chip_pm_get(&desc->irq_data);
2669 retval = __setup_irq(irq, desc, action);
2673 raw_spin_lock_irqsave(&desc->lock, flags);
2674 desc->istate |= IRQS_NMI;
2675 raw_spin_unlock_irqrestore(&desc->lock, flags);
2680 irq_chip_pm_put(&desc->irq_data);
2688 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2689 * @irq: Interrupt line to prepare for NMI delivery
2691 * This call prepares an interrupt line to deliver NMI on the current CPU,
2692 * before that interrupt line gets enabled with enable_percpu_nmi().
2694 * As a CPU local operation, this should be called from non-preemptible
2697 * If the interrupt line cannot be used to deliver NMIs, function
2698 * will fail returning a negative value.
2700 int prepare_percpu_nmi(unsigned int irq)
2702 unsigned long flags;
2703 struct irq_desc *desc;
2706 WARN_ON(preemptible());
2708 desc = irq_get_desc_lock(irq, &flags,
2709 IRQ_GET_DESC_CHECK_PERCPU);
2713 if (WARN(!(desc->istate & IRQS_NMI),
2714 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2720 ret = irq_nmi_setup(desc);
2722 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2727 irq_put_desc_unlock(desc, flags);
2732 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2733 * @irq: Interrupt line from which CPU local NMI configuration should be
2736 * This call undoes the setup done by prepare_percpu_nmi().
2738 * IRQ line should not be enabled for the current CPU.
2740 * As a CPU local operation, this should be called from non-preemptible
2743 void teardown_percpu_nmi(unsigned int irq)
2745 unsigned long flags;
2746 struct irq_desc *desc;
2748 WARN_ON(preemptible());
2750 desc = irq_get_desc_lock(irq, &flags,
2751 IRQ_GET_DESC_CHECK_PERCPU);
2755 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2758 irq_nmi_teardown(desc);
2760 irq_put_desc_unlock(desc, flags);
2763 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2766 struct irq_chip *chip;
2770 chip = irq_data_get_irq_chip(data);
2771 if (WARN_ON_ONCE(!chip))
2773 if (chip->irq_get_irqchip_state)
2775 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2776 data = data->parent_data;
2783 err = chip->irq_get_irqchip_state(data, which, state);
2788 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2789 * @irq: Interrupt line that is forwarded to a VM
2790 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2791 * @state: a pointer to a boolean where the state is to be stored
2793 * This call snapshots the internal irqchip state of an
2794 * interrupt, returning into @state the bit corresponding to
2797 * This function should be called with preemption disabled if the
2798 * interrupt controller has per-cpu registers.
2800 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2803 struct irq_desc *desc;
2804 struct irq_data *data;
2805 unsigned long flags;
2808 desc = irq_get_desc_buslock(irq, &flags, 0);
2812 data = irq_desc_get_irq_data(desc);
2814 err = __irq_get_irqchip_state(data, which, state);
2816 irq_put_desc_busunlock(desc, flags);
2819 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2822 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2823 * @irq: Interrupt line that is forwarded to a VM
2824 * @which: State to be restored (one of IRQCHIP_STATE_*)
2825 * @val: Value corresponding to @which
2827 * This call sets the internal irqchip state of an interrupt,
2828 * depending on the value of @which.
2830 * This function should be called with preemption disabled if the
2831 * interrupt controller has per-cpu registers.
2833 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2836 struct irq_desc *desc;
2837 struct irq_data *data;
2838 struct irq_chip *chip;
2839 unsigned long flags;
2842 desc = irq_get_desc_buslock(irq, &flags, 0);
2846 data = irq_desc_get_irq_data(desc);
2849 chip = irq_data_get_irq_chip(data);
2850 if (WARN_ON_ONCE(!chip)) {
2854 if (chip->irq_set_irqchip_state)
2856 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2857 data = data->parent_data;
2864 err = chip->irq_set_irqchip_state(data, which, val);
2867 irq_put_desc_busunlock(desc, flags);
2870 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2873 * irq_has_action - Check whether an interrupt is requested
2874 * @irq: The linux irq number
2876 * Returns: A snapshot of the current state
2878 bool irq_has_action(unsigned int irq)
2883 res = irq_desc_has_action(irq_to_desc(irq));
2887 EXPORT_SYMBOL_GPL(irq_has_action);
2890 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2891 * @irq: The linux irq number
2892 * @bitmask: The bitmask to evaluate
2894 * Returns: True if one of the bits in @bitmask is set
2896 bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2898 struct irq_desc *desc;
2902 desc = irq_to_desc(irq);
2904 res = !!(desc->status_use_accessors & bitmask);
2908 EXPORT_SYMBOL_GPL(irq_check_status_bit);