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 static void irq_validate_effective_affinity(struct irq_data *data)
200 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
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);
211 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
214 struct irq_desc *desc = irq_data_to_desc(data);
215 struct irq_chip *chip = irq_data_get_irq_chip(data);
218 if (!chip || !chip->irq_set_affinity)
222 * If this is a managed interrupt and housekeeping is enabled on
223 * it check whether the requested affinity mask intersects with
224 * a housekeeping CPU. If so, then remove the isolated CPUs from
225 * the mask and just keep the housekeeping CPU(s). This prevents
226 * the affinity setter from routing the interrupt to an isolated
227 * CPU to avoid that I/O submitted from a housekeeping CPU causes
228 * interrupts on an isolated one.
230 * If the masks do not intersect or include online CPU(s) then
231 * keep the requested mask. The isolated target CPUs are only
232 * receiving interrupts when the I/O operation was submitted
233 * directly from them.
235 * If all housekeeping CPUs in the affinity mask are offline, the
236 * interrupt will be migrated by the CPU hotplug code once a
237 * housekeeping CPU which belongs to the affinity mask comes
240 if (irqd_affinity_is_managed(data) &&
241 housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
242 const struct cpumask *hk_mask, *prog_mask;
244 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
245 static struct cpumask tmp_mask;
247 hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
249 raw_spin_lock(&tmp_mask_lock);
250 cpumask_and(&tmp_mask, mask, hk_mask);
251 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
254 prog_mask = &tmp_mask;
255 ret = chip->irq_set_affinity(data, prog_mask, force);
256 raw_spin_unlock(&tmp_mask_lock);
258 ret = chip->irq_set_affinity(data, mask, force);
261 case IRQ_SET_MASK_OK:
262 case IRQ_SET_MASK_OK_DONE:
263 cpumask_copy(desc->irq_common_data.affinity, mask);
265 case IRQ_SET_MASK_OK_NOCOPY:
266 irq_validate_effective_affinity(data);
267 irq_set_thread_affinity(desc);
274 #ifdef CONFIG_GENERIC_PENDING_IRQ
275 static inline int irq_set_affinity_pending(struct irq_data *data,
276 const struct cpumask *dest)
278 struct irq_desc *desc = irq_data_to_desc(data);
280 irqd_set_move_pending(data);
281 irq_copy_pending(desc, dest);
285 static inline int irq_set_affinity_pending(struct irq_data *data,
286 const struct cpumask *dest)
292 static int irq_try_set_affinity(struct irq_data *data,
293 const struct cpumask *dest, bool force)
295 int ret = irq_do_set_affinity(data, dest, force);
298 * In case that the underlying vector management is busy and the
299 * architecture supports the generic pending mechanism then utilize
300 * this to avoid returning an error to user space.
302 if (ret == -EBUSY && !force)
303 ret = irq_set_affinity_pending(data, dest);
307 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
310 struct irq_chip *chip = irq_data_get_irq_chip(data);
311 struct irq_desc *desc = irq_data_to_desc(data);
314 if (!chip || !chip->irq_set_affinity)
317 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
318 ret = irq_try_set_affinity(data, mask, force);
320 irqd_set_move_pending(data);
321 irq_copy_pending(desc, mask);
324 if (desc->affinity_notify) {
325 kref_get(&desc->affinity_notify->kref);
326 schedule_work(&desc->affinity_notify->work);
328 irqd_set(data, IRQD_AFFINITY_SET);
333 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
335 struct irq_desc *desc = irq_to_desc(irq);
342 raw_spin_lock_irqsave(&desc->lock, flags);
343 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
344 raw_spin_unlock_irqrestore(&desc->lock, flags);
348 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
351 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
355 desc->affinity_hint = m;
356 irq_put_desc_unlock(desc, flags);
357 /* set the initial affinity to prevent every interrupt being on CPU0 */
359 __irq_set_affinity(irq, m, false);
362 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
364 static void irq_affinity_notify(struct work_struct *work)
366 struct irq_affinity_notify *notify =
367 container_of(work, struct irq_affinity_notify, work);
368 struct irq_desc *desc = irq_to_desc(notify->irq);
369 cpumask_var_t cpumask;
372 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
375 raw_spin_lock_irqsave(&desc->lock, flags);
376 if (irq_move_pending(&desc->irq_data))
377 irq_get_pending(cpumask, desc);
379 cpumask_copy(cpumask, desc->irq_common_data.affinity);
380 raw_spin_unlock_irqrestore(&desc->lock, flags);
382 notify->notify(notify, cpumask);
384 free_cpumask_var(cpumask);
386 kref_put(¬ify->kref, notify->release);
390 * irq_set_affinity_notifier - control notification of IRQ affinity changes
391 * @irq: Interrupt for which to enable/disable notification
392 * @notify: Context for notification, or %NULL to disable
393 * notification. Function pointers must be initialised;
394 * the other fields will be initialised by this function.
396 * Must be called in process context. Notification may only be enabled
397 * after the IRQ is allocated and must be disabled before the IRQ is
398 * freed using free_irq().
401 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
403 struct irq_desc *desc = irq_to_desc(irq);
404 struct irq_affinity_notify *old_notify;
407 /* The release function is promised process context */
410 if (!desc || desc->istate & IRQS_NMI)
413 /* Complete initialisation of *notify */
416 kref_init(¬ify->kref);
417 INIT_WORK(¬ify->work, irq_affinity_notify);
420 raw_spin_lock_irqsave(&desc->lock, flags);
421 old_notify = desc->affinity_notify;
422 desc->affinity_notify = notify;
423 raw_spin_unlock_irqrestore(&desc->lock, flags);
426 cancel_work_sync(&old_notify->work);
427 kref_put(&old_notify->kref, old_notify->release);
432 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
434 #ifndef CONFIG_AUTO_IRQ_AFFINITY
436 * Generic version of the affinity autoselector.
438 int irq_setup_affinity(struct irq_desc *desc)
440 struct cpumask *set = irq_default_affinity;
441 int ret, node = irq_desc_get_node(desc);
442 static DEFINE_RAW_SPINLOCK(mask_lock);
443 static struct cpumask mask;
445 /* Excludes PER_CPU and NO_BALANCE interrupts */
446 if (!__irq_can_set_affinity(desc))
449 raw_spin_lock(&mask_lock);
451 * Preserve the managed affinity setting and a userspace affinity
452 * setup, but make sure that one of the targets is online.
454 if (irqd_affinity_is_managed(&desc->irq_data) ||
455 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
456 if (cpumask_intersects(desc->irq_common_data.affinity,
458 set = desc->irq_common_data.affinity;
460 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
463 cpumask_and(&mask, cpu_online_mask, set);
464 if (cpumask_empty(&mask))
465 cpumask_copy(&mask, cpu_online_mask);
467 if (node != NUMA_NO_NODE) {
468 const struct cpumask *nodemask = cpumask_of_node(node);
470 /* make sure at least one of the cpus in nodemask is online */
471 if (cpumask_intersects(&mask, nodemask))
472 cpumask_and(&mask, &mask, nodemask);
474 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
475 raw_spin_unlock(&mask_lock);
479 /* Wrapper for ALPHA specific affinity selector magic */
480 int irq_setup_affinity(struct irq_desc *desc)
482 return irq_select_affinity(irq_desc_get_irq(desc));
484 #endif /* CONFIG_AUTO_IRQ_AFFINITY */
485 #endif /* CONFIG_SMP */
489 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
490 * @irq: interrupt number to set affinity
491 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
492 * specific data for percpu_devid interrupts
494 * This function uses the vCPU specific data to set the vCPU
495 * affinity for an irq. The vCPU specific data is passed from
496 * outside, such as KVM. One example code path is as below:
497 * KVM -> IOMMU -> irq_set_vcpu_affinity().
499 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
502 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
503 struct irq_data *data;
504 struct irq_chip *chip;
510 data = irq_desc_get_irq_data(desc);
512 chip = irq_data_get_irq_chip(data);
513 if (chip && chip->irq_set_vcpu_affinity)
515 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
516 data = data->parent_data;
523 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
524 irq_put_desc_unlock(desc, flags);
528 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
530 void __disable_irq(struct irq_desc *desc)
536 static int __disable_irq_nosync(unsigned int irq)
539 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
544 irq_put_desc_busunlock(desc, flags);
549 * disable_irq_nosync - disable an irq without waiting
550 * @irq: Interrupt to disable
552 * Disable the selected interrupt line. Disables and Enables are
554 * Unlike disable_irq(), this function does not ensure existing
555 * instances of the IRQ handler have completed before returning.
557 * This function may be called from IRQ context.
559 void disable_irq_nosync(unsigned int irq)
561 __disable_irq_nosync(irq);
563 EXPORT_SYMBOL(disable_irq_nosync);
566 * disable_irq - disable an irq and wait for completion
567 * @irq: Interrupt to disable
569 * Disable the selected interrupt line. Enables and Disables are
571 * This function waits for any pending IRQ handlers for this interrupt
572 * to complete before returning. If you use this function while
573 * holding a resource the IRQ handler may need you will deadlock.
575 * This function may be called - with care - from IRQ context.
577 void disable_irq(unsigned int irq)
579 if (!__disable_irq_nosync(irq))
580 synchronize_irq(irq);
582 EXPORT_SYMBOL(disable_irq);
585 * disable_hardirq - disables an irq and waits for hardirq completion
586 * @irq: Interrupt to disable
588 * Disable the selected interrupt line. Enables and Disables are
590 * This function waits for any pending hard IRQ handlers for this
591 * interrupt to complete before returning. If you use this function while
592 * holding a resource the hard IRQ handler may need you will deadlock.
594 * When used to optimistically disable an interrupt from atomic context
595 * the return value must be checked.
597 * Returns: false if a threaded handler is active.
599 * This function may be called - with care - from IRQ context.
601 bool disable_hardirq(unsigned int irq)
603 if (!__disable_irq_nosync(irq))
604 return synchronize_hardirq(irq);
608 EXPORT_SYMBOL_GPL(disable_hardirq);
611 * disable_nmi_nosync - disable an nmi without waiting
612 * @irq: Interrupt to disable
614 * Disable the selected interrupt line. Disables and enables are
616 * The interrupt to disable must have been requested through request_nmi.
617 * Unlike disable_nmi(), this function does not ensure existing
618 * instances of the IRQ handler have completed before returning.
620 void disable_nmi_nosync(unsigned int irq)
622 disable_irq_nosync(irq);
625 void __enable_irq(struct irq_desc *desc)
627 switch (desc->depth) {
630 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
631 irq_desc_get_irq(desc));
634 if (desc->istate & IRQS_SUSPENDED)
636 /* Prevent probing on this irq: */
637 irq_settings_set_noprobe(desc);
639 * Call irq_startup() not irq_enable() here because the
640 * interrupt might be marked NOAUTOEN. So irq_startup()
641 * needs to be invoked when it gets enabled the first
642 * time. If it was already started up, then irq_startup()
643 * will invoke irq_enable() under the hood.
645 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
654 * enable_irq - enable handling of an irq
655 * @irq: Interrupt to enable
657 * Undoes the effect of one call to disable_irq(). If this
658 * matches the last disable, processing of interrupts on this
659 * IRQ line is re-enabled.
661 * This function may be called from IRQ context only when
662 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
664 void enable_irq(unsigned int irq)
667 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
671 if (WARN(!desc->irq_data.chip,
672 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
677 irq_put_desc_busunlock(desc, flags);
679 EXPORT_SYMBOL(enable_irq);
682 * enable_nmi - enable handling of an nmi
683 * @irq: Interrupt to enable
685 * The interrupt to enable must have been requested through request_nmi.
686 * Undoes the effect of one call to disable_nmi(). If this
687 * matches the last disable, processing of interrupts on this
688 * IRQ line is re-enabled.
690 void enable_nmi(unsigned int irq)
695 static int set_irq_wake_real(unsigned int irq, unsigned int on)
697 struct irq_desc *desc = irq_to_desc(irq);
700 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
703 if (desc->irq_data.chip->irq_set_wake)
704 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
710 * irq_set_irq_wake - control irq power management wakeup
711 * @irq: interrupt to control
712 * @on: enable/disable power management wakeup
714 * Enable/disable power management wakeup mode, which is
715 * disabled by default. Enables and disables must match,
716 * just as they match for non-wakeup mode support.
718 * Wakeup mode lets this IRQ wake the system from sleep
719 * states like "suspend to RAM".
721 * Note: irq enable/disable state is completely orthogonal
722 * to the enable/disable state of irq wake. An irq can be
723 * disabled with disable_irq() and still wake the system as
724 * long as the irq has wake enabled. If this does not hold,
725 * then the underlying irq chip and the related driver need
726 * to be investigated.
728 int irq_set_irq_wake(unsigned int irq, unsigned int on)
731 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
737 /* Don't use NMIs as wake up interrupts please */
738 if (desc->istate & IRQS_NMI) {
743 /* wakeup-capable irqs can be shared between drivers that
744 * don't need to have the same sleep mode behaviors.
747 if (desc->wake_depth++ == 0) {
748 ret = set_irq_wake_real(irq, on);
750 desc->wake_depth = 0;
752 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
755 if (desc->wake_depth == 0) {
756 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
757 } else if (--desc->wake_depth == 0) {
758 ret = set_irq_wake_real(irq, on);
760 desc->wake_depth = 1;
762 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
767 irq_put_desc_busunlock(desc, flags);
770 EXPORT_SYMBOL(irq_set_irq_wake);
773 * Internal function that tells the architecture code whether a
774 * particular irq has been exclusively allocated or is available
777 int can_request_irq(unsigned int irq, unsigned long irqflags)
780 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
786 if (irq_settings_can_request(desc)) {
788 irqflags & desc->action->flags & IRQF_SHARED)
791 irq_put_desc_unlock(desc, flags);
795 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
797 struct irq_chip *chip = desc->irq_data.chip;
800 if (!chip || !chip->irq_set_type) {
802 * IRQF_TRIGGER_* but the PIC does not support multiple
805 pr_debug("No set_type function for IRQ %d (%s)\n",
806 irq_desc_get_irq(desc),
807 chip ? (chip->name ? : "unknown") : "unknown");
811 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
812 if (!irqd_irq_masked(&desc->irq_data))
814 if (!irqd_irq_disabled(&desc->irq_data))
818 /* Mask all flags except trigger mode */
819 flags &= IRQ_TYPE_SENSE_MASK;
820 ret = chip->irq_set_type(&desc->irq_data, flags);
823 case IRQ_SET_MASK_OK:
824 case IRQ_SET_MASK_OK_DONE:
825 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
826 irqd_set(&desc->irq_data, flags);
829 case IRQ_SET_MASK_OK_NOCOPY:
830 flags = irqd_get_trigger_type(&desc->irq_data);
831 irq_settings_set_trigger_mask(desc, flags);
832 irqd_clear(&desc->irq_data, IRQD_LEVEL);
833 irq_settings_clr_level(desc);
834 if (flags & IRQ_TYPE_LEVEL_MASK) {
835 irq_settings_set_level(desc);
836 irqd_set(&desc->irq_data, IRQD_LEVEL);
842 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
843 flags, irq_desc_get_irq(desc), chip->irq_set_type);
850 #ifdef CONFIG_HARDIRQS_SW_RESEND
851 int irq_set_parent(int irq, int parent_irq)
854 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
859 desc->parent_irq = parent_irq;
861 irq_put_desc_unlock(desc, flags);
864 EXPORT_SYMBOL_GPL(irq_set_parent);
868 * Default primary interrupt handler for threaded interrupts. Is
869 * assigned as primary handler when request_threaded_irq is called
870 * with handler == NULL. Useful for oneshot interrupts.
872 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
874 return IRQ_WAKE_THREAD;
878 * Primary handler for nested threaded interrupts. Should never be
881 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
883 WARN(1, "Primary handler called for nested irq %d\n", irq);
887 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
889 WARN(1, "Secondary action handler called for irq %d\n", irq);
893 static int irq_wait_for_interrupt(struct irqaction *action)
896 set_current_state(TASK_INTERRUPTIBLE);
898 if (kthread_should_stop()) {
899 /* may need to run one last time */
900 if (test_and_clear_bit(IRQTF_RUNTHREAD,
901 &action->thread_flags)) {
902 __set_current_state(TASK_RUNNING);
905 __set_current_state(TASK_RUNNING);
909 if (test_and_clear_bit(IRQTF_RUNTHREAD,
910 &action->thread_flags)) {
911 __set_current_state(TASK_RUNNING);
919 * Oneshot interrupts keep the irq line masked until the threaded
920 * handler finished. unmask if the interrupt has not been disabled and
923 static void irq_finalize_oneshot(struct irq_desc *desc,
924 struct irqaction *action)
926 if (!(desc->istate & IRQS_ONESHOT) ||
927 action->handler == irq_forced_secondary_handler)
931 raw_spin_lock_irq(&desc->lock);
934 * Implausible though it may be we need to protect us against
935 * the following scenario:
937 * The thread is faster done than the hard interrupt handler
938 * on the other CPU. If we unmask the irq line then the
939 * interrupt can come in again and masks the line, leaves due
940 * to IRQS_INPROGRESS and the irq line is masked forever.
942 * This also serializes the state of shared oneshot handlers
943 * versus "desc->threads_onehsot |= action->thread_mask;" in
944 * irq_wake_thread(). See the comment there which explains the
947 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
948 raw_spin_unlock_irq(&desc->lock);
949 chip_bus_sync_unlock(desc);
955 * Now check again, whether the thread should run. Otherwise
956 * we would clear the threads_oneshot bit of this thread which
959 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
962 desc->threads_oneshot &= ~action->thread_mask;
964 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
965 irqd_irq_masked(&desc->irq_data))
966 unmask_threaded_irq(desc);
969 raw_spin_unlock_irq(&desc->lock);
970 chip_bus_sync_unlock(desc);
975 * Check whether we need to change the affinity of the interrupt thread.
978 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
983 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
987 * In case we are out of memory we set IRQTF_AFFINITY again and
988 * try again next time
990 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
991 set_bit(IRQTF_AFFINITY, &action->thread_flags);
995 raw_spin_lock_irq(&desc->lock);
997 * This code is triggered unconditionally. Check the affinity
998 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1000 if (cpumask_available(desc->irq_common_data.affinity)) {
1001 const struct cpumask *m;
1003 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1004 cpumask_copy(mask, m);
1008 raw_spin_unlock_irq(&desc->lock);
1011 set_cpus_allowed_ptr(current, mask);
1012 free_cpumask_var(mask);
1016 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1020 * Interrupts which are not explicitly requested as threaded
1021 * interrupts rely on the implicit bh/preempt disable of the hard irq
1022 * context. So we need to disable bh here to avoid deadlocks and other
1026 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1031 ret = action->thread_fn(action->irq, action->dev_id);
1032 if (ret == IRQ_HANDLED)
1033 atomic_inc(&desc->threads_handled);
1035 irq_finalize_oneshot(desc, action);
1041 * Interrupts explicitly requested as threaded interrupts want to be
1042 * preemtible - many of them need to sleep and wait for slow busses to
1045 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1046 struct irqaction *action)
1050 ret = action->thread_fn(action->irq, action->dev_id);
1051 if (ret == IRQ_HANDLED)
1052 atomic_inc(&desc->threads_handled);
1054 irq_finalize_oneshot(desc, action);
1058 static void wake_threads_waitq(struct irq_desc *desc)
1060 if (atomic_dec_and_test(&desc->threads_active))
1061 wake_up(&desc->wait_for_threads);
1064 static void irq_thread_dtor(struct callback_head *unused)
1066 struct task_struct *tsk = current;
1067 struct irq_desc *desc;
1068 struct irqaction *action;
1070 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1073 action = kthread_data(tsk);
1075 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1076 tsk->comm, tsk->pid, action->irq);
1079 desc = irq_to_desc(action->irq);
1081 * If IRQTF_RUNTHREAD is set, we need to decrement
1082 * desc->threads_active and wake possible waiters.
1084 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1085 wake_threads_waitq(desc);
1087 /* Prevent a stale desc->threads_oneshot */
1088 irq_finalize_oneshot(desc, action);
1091 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1093 struct irqaction *secondary = action->secondary;
1095 if (WARN_ON_ONCE(!secondary))
1098 raw_spin_lock_irq(&desc->lock);
1099 __irq_wake_thread(desc, secondary);
1100 raw_spin_unlock_irq(&desc->lock);
1104 * Interrupt handler thread
1106 static int irq_thread(void *data)
1108 struct callback_head on_exit_work;
1109 struct irqaction *action = data;
1110 struct irq_desc *desc = irq_to_desc(action->irq);
1111 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1112 struct irqaction *action);
1114 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1115 &action->thread_flags))
1116 handler_fn = irq_forced_thread_fn;
1118 handler_fn = irq_thread_fn;
1120 init_task_work(&on_exit_work, irq_thread_dtor);
1121 task_work_add(current, &on_exit_work, false);
1123 irq_thread_check_affinity(desc, action);
1125 while (!irq_wait_for_interrupt(action)) {
1126 irqreturn_t action_ret;
1128 irq_thread_check_affinity(desc, action);
1130 action_ret = handler_fn(desc, action);
1131 if (action_ret == IRQ_WAKE_THREAD)
1132 irq_wake_secondary(desc, action);
1134 wake_threads_waitq(desc);
1138 * This is the regular exit path. __free_irq() is stopping the
1139 * thread via kthread_stop() after calling
1140 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1141 * oneshot mask bit can be set.
1143 task_work_cancel(current, irq_thread_dtor);
1148 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1149 * @irq: Interrupt line
1150 * @dev_id: Device identity for which the thread should be woken
1153 void irq_wake_thread(unsigned int irq, void *dev_id)
1155 struct irq_desc *desc = irq_to_desc(irq);
1156 struct irqaction *action;
1157 unsigned long flags;
1159 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1162 raw_spin_lock_irqsave(&desc->lock, flags);
1163 for_each_action_of_desc(desc, action) {
1164 if (action->dev_id == dev_id) {
1166 __irq_wake_thread(desc, action);
1170 raw_spin_unlock_irqrestore(&desc->lock, flags);
1172 EXPORT_SYMBOL_GPL(irq_wake_thread);
1174 static int irq_setup_forced_threading(struct irqaction *new)
1176 if (!force_irqthreads)
1178 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1182 * No further action required for interrupts which are requested as
1183 * threaded interrupts already
1185 if (new->handler == irq_default_primary_handler)
1188 new->flags |= IRQF_ONESHOT;
1191 * Handle the case where we have a real primary handler and a
1192 * thread handler. We force thread them as well by creating a
1195 if (new->handler && new->thread_fn) {
1196 /* Allocate the secondary action */
1197 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1198 if (!new->secondary)
1200 new->secondary->handler = irq_forced_secondary_handler;
1201 new->secondary->thread_fn = new->thread_fn;
1202 new->secondary->dev_id = new->dev_id;
1203 new->secondary->irq = new->irq;
1204 new->secondary->name = new->name;
1206 /* Deal with the primary handler */
1207 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1208 new->thread_fn = new->handler;
1209 new->handler = irq_default_primary_handler;
1213 static int irq_request_resources(struct irq_desc *desc)
1215 struct irq_data *d = &desc->irq_data;
1216 struct irq_chip *c = d->chip;
1218 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1221 static void irq_release_resources(struct irq_desc *desc)
1223 struct irq_data *d = &desc->irq_data;
1224 struct irq_chip *c = d->chip;
1226 if (c->irq_release_resources)
1227 c->irq_release_resources(d);
1230 static bool irq_supports_nmi(struct irq_desc *desc)
1232 struct irq_data *d = irq_desc_get_irq_data(desc);
1234 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1235 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1239 /* Don't support NMIs for chips behind a slow bus */
1240 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1243 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1246 static int irq_nmi_setup(struct irq_desc *desc)
1248 struct irq_data *d = irq_desc_get_irq_data(desc);
1249 struct irq_chip *c = d->chip;
1251 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1254 static void irq_nmi_teardown(struct irq_desc *desc)
1256 struct irq_data *d = irq_desc_get_irq_data(desc);
1257 struct irq_chip *c = d->chip;
1259 if (c->irq_nmi_teardown)
1260 c->irq_nmi_teardown(d);
1264 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1266 struct task_struct *t;
1267 struct sched_param param = {
1268 .sched_priority = MAX_USER_RT_PRIO/2,
1272 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1275 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1277 param.sched_priority -= 1;
1283 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1286 * We keep the reference to the task struct even if
1287 * the thread dies to avoid that the interrupt code
1288 * references an already freed task_struct.
1290 new->thread = get_task_struct(t);
1292 * Tell the thread to set its affinity. This is
1293 * important for shared interrupt handlers as we do
1294 * not invoke setup_affinity() for the secondary
1295 * handlers as everything is already set up. Even for
1296 * interrupts marked with IRQF_NO_BALANCE this is
1297 * correct as we want the thread to move to the cpu(s)
1298 * on which the requesting code placed the interrupt.
1300 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1305 * Internal function to register an irqaction - typically used to
1306 * allocate special interrupts that are part of the architecture.
1310 * desc->request_mutex Provides serialization against a concurrent free_irq()
1311 * chip_bus_lock Provides serialization for slow bus operations
1312 * desc->lock Provides serialization against hard interrupts
1314 * chip_bus_lock and desc->lock are sufficient for all other management and
1315 * interrupt related functions. desc->request_mutex solely serializes
1316 * request/free_irq().
1319 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1321 struct irqaction *old, **old_ptr;
1322 unsigned long flags, thread_mask = 0;
1323 int ret, nested, shared = 0;
1328 if (desc->irq_data.chip == &no_irq_chip)
1330 if (!try_module_get(desc->owner))
1336 * If the trigger type is not specified by the caller,
1337 * then use the default for this interrupt.
1339 if (!(new->flags & IRQF_TRIGGER_MASK))
1340 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1343 * Check whether the interrupt nests into another interrupt
1346 nested = irq_settings_is_nested_thread(desc);
1348 if (!new->thread_fn) {
1353 * Replace the primary handler which was provided from
1354 * the driver for non nested interrupt handling by the
1355 * dummy function which warns when called.
1357 new->handler = irq_nested_primary_handler;
1359 if (irq_settings_can_thread(desc)) {
1360 ret = irq_setup_forced_threading(new);
1367 * Create a handler thread when a thread function is supplied
1368 * and the interrupt does not nest into another interrupt
1371 if (new->thread_fn && !nested) {
1372 ret = setup_irq_thread(new, irq, false);
1375 if (new->secondary) {
1376 ret = setup_irq_thread(new->secondary, irq, true);
1383 * Drivers are often written to work w/o knowledge about the
1384 * underlying irq chip implementation, so a request for a
1385 * threaded irq without a primary hard irq context handler
1386 * requires the ONESHOT flag to be set. Some irq chips like
1387 * MSI based interrupts are per se one shot safe. Check the
1388 * chip flags, so we can avoid the unmask dance at the end of
1389 * the threaded handler for those.
1391 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1392 new->flags &= ~IRQF_ONESHOT;
1395 * Protects against a concurrent __free_irq() call which might wait
1396 * for synchronize_hardirq() to complete without holding the optional
1397 * chip bus lock and desc->lock. Also protects against handing out
1398 * a recycled oneshot thread_mask bit while it's still in use by
1399 * its previous owner.
1401 mutex_lock(&desc->request_mutex);
1404 * Acquire bus lock as the irq_request_resources() callback below
1405 * might rely on the serialization or the magic power management
1406 * functions which are abusing the irq_bus_lock() callback,
1408 chip_bus_lock(desc);
1410 /* First installed action requests resources. */
1411 if (!desc->action) {
1412 ret = irq_request_resources(desc);
1414 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1415 new->name, irq, desc->irq_data.chip->name);
1416 goto out_bus_unlock;
1421 * The following block of code has to be executed atomically
1422 * protected against a concurrent interrupt and any of the other
1423 * management calls which are not serialized via
1424 * desc->request_mutex or the optional bus lock.
1426 raw_spin_lock_irqsave(&desc->lock, flags);
1427 old_ptr = &desc->action;
1431 * Can't share interrupts unless both agree to and are
1432 * the same type (level, edge, polarity). So both flag
1433 * fields must have IRQF_SHARED set and the bits which
1434 * set the trigger type must match. Also all must
1436 * Interrupt lines used for NMIs cannot be shared.
1438 unsigned int oldtype;
1440 if (desc->istate & IRQS_NMI) {
1441 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1442 new->name, irq, desc->irq_data.chip->name);
1448 * If nobody did set the configuration before, inherit
1449 * the one provided by the requester.
1451 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1452 oldtype = irqd_get_trigger_type(&desc->irq_data);
1454 oldtype = new->flags & IRQF_TRIGGER_MASK;
1455 irqd_set_trigger_type(&desc->irq_data, oldtype);
1458 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1459 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1460 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1463 /* All handlers must agree on per-cpuness */
1464 if ((old->flags & IRQF_PERCPU) !=
1465 (new->flags & IRQF_PERCPU))
1468 /* add new interrupt at end of irq queue */
1471 * Or all existing action->thread_mask bits,
1472 * so we can find the next zero bit for this
1475 thread_mask |= old->thread_mask;
1476 old_ptr = &old->next;
1483 * Setup the thread mask for this irqaction for ONESHOT. For
1484 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1485 * conditional in irq_wake_thread().
1487 if (new->flags & IRQF_ONESHOT) {
1489 * Unlikely to have 32 resp 64 irqs sharing one line,
1492 if (thread_mask == ~0UL) {
1497 * The thread_mask for the action is or'ed to
1498 * desc->thread_active to indicate that the
1499 * IRQF_ONESHOT thread handler has been woken, but not
1500 * yet finished. The bit is cleared when a thread
1501 * completes. When all threads of a shared interrupt
1502 * line have completed desc->threads_active becomes
1503 * zero and the interrupt line is unmasked. See
1504 * handle.c:irq_wake_thread() for further information.
1506 * If no thread is woken by primary (hard irq context)
1507 * interrupt handlers, then desc->threads_active is
1508 * also checked for zero to unmask the irq line in the
1509 * affected hard irq flow handlers
1510 * (handle_[fasteoi|level]_irq).
1512 * The new action gets the first zero bit of
1513 * thread_mask assigned. See the loop above which or's
1514 * all existing action->thread_mask bits.
1516 new->thread_mask = 1UL << ffz(thread_mask);
1518 } else if (new->handler == irq_default_primary_handler &&
1519 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1521 * The interrupt was requested with handler = NULL, so
1522 * we use the default primary handler for it. But it
1523 * does not have the oneshot flag set. In combination
1524 * with level interrupts this is deadly, because the
1525 * default primary handler just wakes the thread, then
1526 * the irq lines is reenabled, but the device still
1527 * has the level irq asserted. Rinse and repeat....
1529 * While this works for edge type interrupts, we play
1530 * it safe and reject unconditionally because we can't
1531 * say for sure which type this interrupt really
1532 * has. The type flags are unreliable as the
1533 * underlying chip implementation can override them.
1535 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1542 init_waitqueue_head(&desc->wait_for_threads);
1544 /* Setup the type (level, edge polarity) if configured: */
1545 if (new->flags & IRQF_TRIGGER_MASK) {
1546 ret = __irq_set_trigger(desc,
1547 new->flags & IRQF_TRIGGER_MASK);
1554 * Activate the interrupt. That activation must happen
1555 * independently of IRQ_NOAUTOEN. request_irq() can fail
1556 * and the callers are supposed to handle
1557 * that. enable_irq() of an interrupt requested with
1558 * IRQ_NOAUTOEN is not supposed to fail. The activation
1559 * keeps it in shutdown mode, it merily associates
1560 * resources if necessary and if that's not possible it
1561 * fails. Interrupts which are in managed shutdown mode
1562 * will simply ignore that activation request.
1564 ret = irq_activate(desc);
1568 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1569 IRQS_ONESHOT | IRQS_WAITING);
1570 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1572 if (new->flags & IRQF_PERCPU) {
1573 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1574 irq_settings_set_per_cpu(desc);
1577 if (new->flags & IRQF_ONESHOT)
1578 desc->istate |= IRQS_ONESHOT;
1580 /* Exclude IRQ from balancing if requested */
1581 if (new->flags & IRQF_NOBALANCING) {
1582 irq_settings_set_no_balancing(desc);
1583 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1586 if (irq_settings_can_autoenable(desc)) {
1587 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1590 * Shared interrupts do not go well with disabling
1591 * auto enable. The sharing interrupt might request
1592 * it while it's still disabled and then wait for
1593 * interrupts forever.
1595 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1596 /* Undo nested disables: */
1600 } else if (new->flags & IRQF_TRIGGER_MASK) {
1601 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1602 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1605 /* hope the handler works with current trigger mode */
1606 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1612 irq_pm_install_action(desc, new);
1614 /* Reset broken irq detection when installing new handler */
1615 desc->irq_count = 0;
1616 desc->irqs_unhandled = 0;
1619 * Check whether we disabled the irq via the spurious handler
1620 * before. Reenable it and give it another chance.
1622 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1623 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1627 raw_spin_unlock_irqrestore(&desc->lock, flags);
1628 chip_bus_sync_unlock(desc);
1629 mutex_unlock(&desc->request_mutex);
1631 irq_setup_timings(desc, new);
1634 * Strictly no need to wake it up, but hung_task complains
1635 * when no hard interrupt wakes the thread up.
1638 wake_up_process(new->thread);
1640 wake_up_process(new->secondary->thread);
1642 register_irq_proc(irq, desc);
1644 register_handler_proc(irq, new);
1648 if (!(new->flags & IRQF_PROBE_SHARED)) {
1649 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1650 irq, new->flags, new->name, old->flags, old->name);
1651 #ifdef CONFIG_DEBUG_SHIRQ
1658 raw_spin_unlock_irqrestore(&desc->lock, flags);
1661 irq_release_resources(desc);
1663 chip_bus_sync_unlock(desc);
1664 mutex_unlock(&desc->request_mutex);
1668 struct task_struct *t = new->thread;
1674 if (new->secondary && new->secondary->thread) {
1675 struct task_struct *t = new->secondary->thread;
1677 new->secondary->thread = NULL;
1682 module_put(desc->owner);
1687 * setup_irq - setup an interrupt
1688 * @irq: Interrupt line to setup
1689 * @act: irqaction for the interrupt
1691 * Used to statically setup interrupts in the early boot process.
1693 int setup_irq(unsigned int irq, struct irqaction *act)
1696 struct irq_desc *desc = irq_to_desc(irq);
1698 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1701 retval = irq_chip_pm_get(&desc->irq_data);
1705 retval = __setup_irq(irq, desc, act);
1708 irq_chip_pm_put(&desc->irq_data);
1712 EXPORT_SYMBOL_GPL(setup_irq);
1715 * Internal function to unregister an irqaction - used to free
1716 * regular and special interrupts that are part of the architecture.
1718 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1720 unsigned irq = desc->irq_data.irq;
1721 struct irqaction *action, **action_ptr;
1722 unsigned long flags;
1724 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1726 mutex_lock(&desc->request_mutex);
1727 chip_bus_lock(desc);
1728 raw_spin_lock_irqsave(&desc->lock, flags);
1731 * There can be multiple actions per IRQ descriptor, find the right
1732 * one based on the dev_id:
1734 action_ptr = &desc->action;
1736 action = *action_ptr;
1739 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1740 raw_spin_unlock_irqrestore(&desc->lock, flags);
1741 chip_bus_sync_unlock(desc);
1742 mutex_unlock(&desc->request_mutex);
1746 if (action->dev_id == dev_id)
1748 action_ptr = &action->next;
1751 /* Found it - now remove it from the list of entries: */
1752 *action_ptr = action->next;
1754 irq_pm_remove_action(desc, action);
1756 /* If this was the last handler, shut down the IRQ line: */
1757 if (!desc->action) {
1758 irq_settings_clr_disable_unlazy(desc);
1759 /* Only shutdown. Deactivate after synchronize_hardirq() */
1764 /* make sure affinity_hint is cleaned up */
1765 if (WARN_ON_ONCE(desc->affinity_hint))
1766 desc->affinity_hint = NULL;
1769 raw_spin_unlock_irqrestore(&desc->lock, flags);
1771 * Drop bus_lock here so the changes which were done in the chip
1772 * callbacks above are synced out to the irq chips which hang
1773 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1775 * Aside of that the bus_lock can also be taken from the threaded
1776 * handler in irq_finalize_oneshot() which results in a deadlock
1777 * because kthread_stop() would wait forever for the thread to
1778 * complete, which is blocked on the bus lock.
1780 * The still held desc->request_mutex() protects against a
1781 * concurrent request_irq() of this irq so the release of resources
1782 * and timing data is properly serialized.
1784 chip_bus_sync_unlock(desc);
1786 unregister_handler_proc(irq, action);
1789 * Make sure it's not being used on another CPU and if the chip
1790 * supports it also make sure that there is no (not yet serviced)
1791 * interrupt in flight at the hardware level.
1793 __synchronize_hardirq(desc, true);
1795 #ifdef CONFIG_DEBUG_SHIRQ
1797 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1798 * event to happen even now it's being freed, so let's make sure that
1799 * is so by doing an extra call to the handler ....
1801 * ( We do this after actually deregistering it, to make sure that a
1802 * 'real' IRQ doesn't run in parallel with our fake. )
1804 if (action->flags & IRQF_SHARED) {
1805 local_irq_save(flags);
1806 action->handler(irq, dev_id);
1807 local_irq_restore(flags);
1812 * The action has already been removed above, but the thread writes
1813 * its oneshot mask bit when it completes. Though request_mutex is
1814 * held across this which prevents __setup_irq() from handing out
1815 * the same bit to a newly requested action.
1817 if (action->thread) {
1818 kthread_stop(action->thread);
1819 put_task_struct(action->thread);
1820 if (action->secondary && action->secondary->thread) {
1821 kthread_stop(action->secondary->thread);
1822 put_task_struct(action->secondary->thread);
1826 /* Last action releases resources */
1827 if (!desc->action) {
1829 * Reaquire bus lock as irq_release_resources() might
1830 * require it to deallocate resources over the slow bus.
1832 chip_bus_lock(desc);
1834 * There is no interrupt on the fly anymore. Deactivate it
1837 raw_spin_lock_irqsave(&desc->lock, flags);
1838 irq_domain_deactivate_irq(&desc->irq_data);
1839 raw_spin_unlock_irqrestore(&desc->lock, flags);
1841 irq_release_resources(desc);
1842 chip_bus_sync_unlock(desc);
1843 irq_remove_timings(desc);
1846 mutex_unlock(&desc->request_mutex);
1848 irq_chip_pm_put(&desc->irq_data);
1849 module_put(desc->owner);
1850 kfree(action->secondary);
1855 * remove_irq - free an interrupt
1856 * @irq: Interrupt line to free
1857 * @act: irqaction for the interrupt
1859 * Used to remove interrupts statically setup by the early boot process.
1861 void remove_irq(unsigned int irq, struct irqaction *act)
1863 struct irq_desc *desc = irq_to_desc(irq);
1865 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1866 __free_irq(desc, act->dev_id);
1868 EXPORT_SYMBOL_GPL(remove_irq);
1871 * free_irq - free an interrupt allocated with request_irq
1872 * @irq: Interrupt line to free
1873 * @dev_id: Device identity to free
1875 * Remove an interrupt handler. The handler is removed and if the
1876 * interrupt line is no longer in use by any driver it is disabled.
1877 * On a shared IRQ the caller must ensure the interrupt is disabled
1878 * on the card it drives before calling this function. The function
1879 * does not return until any executing interrupts for this IRQ
1882 * This function must not be called from interrupt context.
1884 * Returns the devname argument passed to request_irq.
1886 const void *free_irq(unsigned int irq, void *dev_id)
1888 struct irq_desc *desc = irq_to_desc(irq);
1889 struct irqaction *action;
1890 const char *devname;
1892 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1896 if (WARN_ON(desc->affinity_notify))
1897 desc->affinity_notify = NULL;
1900 action = __free_irq(desc, dev_id);
1905 devname = action->name;
1909 EXPORT_SYMBOL(free_irq);
1911 /* This function must be called with desc->lock held */
1912 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1914 const char *devname = NULL;
1916 desc->istate &= ~IRQS_NMI;
1918 if (!WARN_ON(desc->action == NULL)) {
1919 irq_pm_remove_action(desc, desc->action);
1920 devname = desc->action->name;
1921 unregister_handler_proc(irq, desc->action);
1923 kfree(desc->action);
1924 desc->action = NULL;
1927 irq_settings_clr_disable_unlazy(desc);
1928 irq_shutdown_and_deactivate(desc);
1930 irq_release_resources(desc);
1932 irq_chip_pm_put(&desc->irq_data);
1933 module_put(desc->owner);
1938 const void *free_nmi(unsigned int irq, void *dev_id)
1940 struct irq_desc *desc = irq_to_desc(irq);
1941 unsigned long flags;
1942 const void *devname;
1944 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1947 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1950 /* NMI still enabled */
1951 if (WARN_ON(desc->depth == 0))
1952 disable_nmi_nosync(irq);
1954 raw_spin_lock_irqsave(&desc->lock, flags);
1956 irq_nmi_teardown(desc);
1957 devname = __cleanup_nmi(irq, desc);
1959 raw_spin_unlock_irqrestore(&desc->lock, flags);
1965 * request_threaded_irq - allocate an interrupt line
1966 * @irq: Interrupt line to allocate
1967 * @handler: Function to be called when the IRQ occurs.
1968 * Primary handler for threaded interrupts
1969 * If NULL and thread_fn != NULL the default
1970 * primary handler is installed
1971 * @thread_fn: Function called from the irq handler thread
1972 * If NULL, no irq thread is created
1973 * @irqflags: Interrupt type flags
1974 * @devname: An ascii name for the claiming device
1975 * @dev_id: A cookie passed back to the handler function
1977 * This call allocates interrupt resources and enables the
1978 * interrupt line and IRQ handling. From the point this
1979 * call is made your handler function may be invoked. Since
1980 * your handler function must clear any interrupt the board
1981 * raises, you must take care both to initialise your hardware
1982 * and to set up the interrupt handler in the right order.
1984 * If you want to set up a threaded irq handler for your device
1985 * then you need to supply @handler and @thread_fn. @handler is
1986 * still called in hard interrupt context and has to check
1987 * whether the interrupt originates from the device. If yes it
1988 * needs to disable the interrupt on the device and return
1989 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1990 * @thread_fn. This split handler design is necessary to support
1991 * shared interrupts.
1993 * Dev_id must be globally unique. Normally the address of the
1994 * device data structure is used as the cookie. Since the handler
1995 * receives this value it makes sense to use it.
1997 * If your interrupt is shared you must pass a non NULL dev_id
1998 * as this is required when freeing the interrupt.
2002 * IRQF_SHARED Interrupt is shared
2003 * IRQF_TRIGGER_* Specify active edge(s) or level
2006 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2007 irq_handler_t thread_fn, unsigned long irqflags,
2008 const char *devname, void *dev_id)
2010 struct irqaction *action;
2011 struct irq_desc *desc;
2014 if (irq == IRQ_NOTCONNECTED)
2018 * Sanity-check: shared interrupts must pass in a real dev-ID,
2019 * otherwise we'll have trouble later trying to figure out
2020 * which interrupt is which (messes up the interrupt freeing
2023 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2024 * it cannot be set along with IRQF_NO_SUSPEND.
2026 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2027 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2028 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2031 desc = irq_to_desc(irq);
2035 if (!irq_settings_can_request(desc) ||
2036 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2042 handler = irq_default_primary_handler;
2045 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2049 action->handler = handler;
2050 action->thread_fn = thread_fn;
2051 action->flags = irqflags;
2052 action->name = devname;
2053 action->dev_id = dev_id;
2055 retval = irq_chip_pm_get(&desc->irq_data);
2061 retval = __setup_irq(irq, desc, action);
2064 irq_chip_pm_put(&desc->irq_data);
2065 kfree(action->secondary);
2069 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2070 if (!retval && (irqflags & IRQF_SHARED)) {
2072 * It's a shared IRQ -- the driver ought to be prepared for it
2073 * to happen immediately, so let's make sure....
2074 * We disable the irq to make sure that a 'real' IRQ doesn't
2075 * run in parallel with our fake.
2077 unsigned long flags;
2080 local_irq_save(flags);
2082 handler(irq, dev_id);
2084 local_irq_restore(flags);
2090 EXPORT_SYMBOL(request_threaded_irq);
2093 * request_any_context_irq - allocate an interrupt line
2094 * @irq: Interrupt line to allocate
2095 * @handler: Function to be called when the IRQ occurs.
2096 * Threaded handler for threaded interrupts.
2097 * @flags: Interrupt type flags
2098 * @name: An ascii name for the claiming device
2099 * @dev_id: A cookie passed back to the handler function
2101 * This call allocates interrupt resources and enables the
2102 * interrupt line and IRQ handling. It selects either a
2103 * hardirq or threaded handling method depending on the
2106 * On failure, it returns a negative value. On success,
2107 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2109 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2110 unsigned long flags, const char *name, void *dev_id)
2112 struct irq_desc *desc;
2115 if (irq == IRQ_NOTCONNECTED)
2118 desc = irq_to_desc(irq);
2122 if (irq_settings_is_nested_thread(desc)) {
2123 ret = request_threaded_irq(irq, NULL, handler,
2124 flags, name, dev_id);
2125 return !ret ? IRQC_IS_NESTED : ret;
2128 ret = request_irq(irq, handler, flags, name, dev_id);
2129 return !ret ? IRQC_IS_HARDIRQ : ret;
2131 EXPORT_SYMBOL_GPL(request_any_context_irq);
2134 * request_nmi - allocate an interrupt line for NMI delivery
2135 * @irq: Interrupt line to allocate
2136 * @handler: Function to be called when the IRQ occurs.
2137 * Threaded handler for threaded interrupts.
2138 * @irqflags: Interrupt type flags
2139 * @name: An ascii name for the claiming device
2140 * @dev_id: A cookie passed back to the handler function
2142 * This call allocates interrupt resources and enables the
2143 * interrupt line and IRQ handling. It sets up the IRQ line
2144 * to be handled as an NMI.
2146 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2147 * cannot be threaded.
2149 * Interrupt lines requested for NMI delivering must produce per cpu
2150 * interrupts and have auto enabling setting disabled.
2152 * Dev_id must be globally unique. Normally the address of the
2153 * device data structure is used as the cookie. Since the handler
2154 * receives this value it makes sense to use it.
2156 * If the interrupt line cannot be used to deliver NMIs, function
2157 * will fail and return a negative value.
2159 int request_nmi(unsigned int irq, irq_handler_t handler,
2160 unsigned long irqflags, const char *name, void *dev_id)
2162 struct irqaction *action;
2163 struct irq_desc *desc;
2164 unsigned long flags;
2167 if (irq == IRQ_NOTCONNECTED)
2170 /* NMI cannot be shared, used for Polling */
2171 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2174 if (!(irqflags & IRQF_PERCPU))
2180 desc = irq_to_desc(irq);
2182 if (!desc || irq_settings_can_autoenable(desc) ||
2183 !irq_settings_can_request(desc) ||
2184 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2185 !irq_supports_nmi(desc))
2188 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2192 action->handler = handler;
2193 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2194 action->name = name;
2195 action->dev_id = dev_id;
2197 retval = irq_chip_pm_get(&desc->irq_data);
2201 retval = __setup_irq(irq, desc, action);
2205 raw_spin_lock_irqsave(&desc->lock, flags);
2207 /* Setup NMI state */
2208 desc->istate |= IRQS_NMI;
2209 retval = irq_nmi_setup(desc);
2211 __cleanup_nmi(irq, desc);
2212 raw_spin_unlock_irqrestore(&desc->lock, flags);
2216 raw_spin_unlock_irqrestore(&desc->lock, flags);
2221 irq_chip_pm_put(&desc->irq_data);
2228 void enable_percpu_irq(unsigned int irq, unsigned int type)
2230 unsigned int cpu = smp_processor_id();
2231 unsigned long flags;
2232 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2238 * If the trigger type is not specified by the caller, then
2239 * use the default for this interrupt.
2241 type &= IRQ_TYPE_SENSE_MASK;
2242 if (type == IRQ_TYPE_NONE)
2243 type = irqd_get_trigger_type(&desc->irq_data);
2245 if (type != IRQ_TYPE_NONE) {
2248 ret = __irq_set_trigger(desc, type);
2251 WARN(1, "failed to set type for IRQ%d\n", irq);
2256 irq_percpu_enable(desc, cpu);
2258 irq_put_desc_unlock(desc, flags);
2260 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2262 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2264 enable_percpu_irq(irq, type);
2268 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2269 * @irq: Linux irq number to check for
2271 * Must be called from a non migratable context. Returns the enable
2272 * state of a per cpu interrupt on the current cpu.
2274 bool irq_percpu_is_enabled(unsigned int irq)
2276 unsigned int cpu = smp_processor_id();
2277 struct irq_desc *desc;
2278 unsigned long flags;
2281 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2285 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2286 irq_put_desc_unlock(desc, flags);
2290 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2292 void disable_percpu_irq(unsigned int irq)
2294 unsigned int cpu = smp_processor_id();
2295 unsigned long flags;
2296 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2301 irq_percpu_disable(desc, cpu);
2302 irq_put_desc_unlock(desc, flags);
2304 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2306 void disable_percpu_nmi(unsigned int irq)
2308 disable_percpu_irq(irq);
2312 * Internal function to unregister a percpu irqaction.
2314 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2316 struct irq_desc *desc = irq_to_desc(irq);
2317 struct irqaction *action;
2318 unsigned long flags;
2320 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2325 raw_spin_lock_irqsave(&desc->lock, flags);
2327 action = desc->action;
2328 if (!action || action->percpu_dev_id != dev_id) {
2329 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2333 if (!cpumask_empty(desc->percpu_enabled)) {
2334 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2335 irq, cpumask_first(desc->percpu_enabled));
2339 /* Found it - now remove it from the list of entries: */
2340 desc->action = NULL;
2342 desc->istate &= ~IRQS_NMI;
2344 raw_spin_unlock_irqrestore(&desc->lock, flags);
2346 unregister_handler_proc(irq, action);
2348 irq_chip_pm_put(&desc->irq_data);
2349 module_put(desc->owner);
2353 raw_spin_unlock_irqrestore(&desc->lock, flags);
2358 * remove_percpu_irq - free a per-cpu interrupt
2359 * @irq: Interrupt line to free
2360 * @act: irqaction for the interrupt
2362 * Used to remove interrupts statically setup by the early boot process.
2364 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2366 struct irq_desc *desc = irq_to_desc(irq);
2368 if (desc && irq_settings_is_per_cpu_devid(desc))
2369 __free_percpu_irq(irq, act->percpu_dev_id);
2373 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2374 * @irq: Interrupt line to free
2375 * @dev_id: Device identity to free
2377 * Remove a percpu interrupt handler. The handler is removed, but
2378 * the interrupt line is not disabled. This must be done on each
2379 * CPU before calling this function. The function does not return
2380 * until any executing interrupts for this IRQ have completed.
2382 * This function must not be called from interrupt context.
2384 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2386 struct irq_desc *desc = irq_to_desc(irq);
2388 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2391 chip_bus_lock(desc);
2392 kfree(__free_percpu_irq(irq, dev_id));
2393 chip_bus_sync_unlock(desc);
2395 EXPORT_SYMBOL_GPL(free_percpu_irq);
2397 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2399 struct irq_desc *desc = irq_to_desc(irq);
2401 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2404 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2407 kfree(__free_percpu_irq(irq, dev_id));
2411 * setup_percpu_irq - setup a per-cpu interrupt
2412 * @irq: Interrupt line to setup
2413 * @act: irqaction for the interrupt
2415 * Used to statically setup per-cpu interrupts in the early boot process.
2417 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2419 struct irq_desc *desc = irq_to_desc(irq);
2422 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2425 retval = irq_chip_pm_get(&desc->irq_data);
2429 retval = __setup_irq(irq, desc, act);
2432 irq_chip_pm_put(&desc->irq_data);
2438 * __request_percpu_irq - allocate a percpu interrupt line
2439 * @irq: Interrupt line to allocate
2440 * @handler: Function to be called when the IRQ occurs.
2441 * @flags: Interrupt type flags (IRQF_TIMER only)
2442 * @devname: An ascii name for the claiming device
2443 * @dev_id: A percpu cookie passed back to the handler function
2445 * This call allocates interrupt resources and enables the
2446 * interrupt on the local CPU. If the interrupt is supposed to be
2447 * enabled on other CPUs, it has to be done on each CPU using
2448 * enable_percpu_irq().
2450 * Dev_id must be globally unique. It is a per-cpu variable, and
2451 * the handler gets called with the interrupted CPU's instance of
2454 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2455 unsigned long flags, const char *devname,
2456 void __percpu *dev_id)
2458 struct irqaction *action;
2459 struct irq_desc *desc;
2465 desc = irq_to_desc(irq);
2466 if (!desc || !irq_settings_can_request(desc) ||
2467 !irq_settings_is_per_cpu_devid(desc))
2470 if (flags && flags != IRQF_TIMER)
2473 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2477 action->handler = handler;
2478 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2479 action->name = devname;
2480 action->percpu_dev_id = dev_id;
2482 retval = irq_chip_pm_get(&desc->irq_data);
2488 retval = __setup_irq(irq, desc, action);
2491 irq_chip_pm_put(&desc->irq_data);
2497 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2500 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2501 * @irq: Interrupt line to allocate
2502 * @handler: Function to be called when the IRQ occurs.
2503 * @name: An ascii name for the claiming device
2504 * @dev_id: A percpu cookie passed back to the handler function
2506 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2507 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2508 * being enabled on the same CPU by using enable_percpu_nmi().
2510 * Dev_id must be globally unique. It is a per-cpu variable, and
2511 * the handler gets called with the interrupted CPU's instance of
2514 * Interrupt lines requested for NMI delivering should have auto enabling
2517 * If the interrupt line cannot be used to deliver NMIs, function
2518 * will fail returning a negative value.
2520 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2521 const char *name, void __percpu *dev_id)
2523 struct irqaction *action;
2524 struct irq_desc *desc;
2525 unsigned long flags;
2531 desc = irq_to_desc(irq);
2533 if (!desc || !irq_settings_can_request(desc) ||
2534 !irq_settings_is_per_cpu_devid(desc) ||
2535 irq_settings_can_autoenable(desc) ||
2536 !irq_supports_nmi(desc))
2539 /* The line cannot already be NMI */
2540 if (desc->istate & IRQS_NMI)
2543 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2547 action->handler = handler;
2548 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2550 action->name = name;
2551 action->percpu_dev_id = dev_id;
2553 retval = irq_chip_pm_get(&desc->irq_data);
2557 retval = __setup_irq(irq, desc, action);
2561 raw_spin_lock_irqsave(&desc->lock, flags);
2562 desc->istate |= IRQS_NMI;
2563 raw_spin_unlock_irqrestore(&desc->lock, flags);
2568 irq_chip_pm_put(&desc->irq_data);
2576 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2577 * @irq: Interrupt line to prepare for NMI delivery
2579 * This call prepares an interrupt line to deliver NMI on the current CPU,
2580 * before that interrupt line gets enabled with enable_percpu_nmi().
2582 * As a CPU local operation, this should be called from non-preemptible
2585 * If the interrupt line cannot be used to deliver NMIs, function
2586 * will fail returning a negative value.
2588 int prepare_percpu_nmi(unsigned int irq)
2590 unsigned long flags;
2591 struct irq_desc *desc;
2594 WARN_ON(preemptible());
2596 desc = irq_get_desc_lock(irq, &flags,
2597 IRQ_GET_DESC_CHECK_PERCPU);
2601 if (WARN(!(desc->istate & IRQS_NMI),
2602 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2608 ret = irq_nmi_setup(desc);
2610 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2615 irq_put_desc_unlock(desc, flags);
2620 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2621 * @irq: Interrupt line from which CPU local NMI configuration should be
2624 * This call undoes the setup done by prepare_percpu_nmi().
2626 * IRQ line should not be enabled for the current CPU.
2628 * As a CPU local operation, this should be called from non-preemptible
2631 void teardown_percpu_nmi(unsigned int irq)
2633 unsigned long flags;
2634 struct irq_desc *desc;
2636 WARN_ON(preemptible());
2638 desc = irq_get_desc_lock(irq, &flags,
2639 IRQ_GET_DESC_CHECK_PERCPU);
2643 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2646 irq_nmi_teardown(desc);
2648 irq_put_desc_unlock(desc, flags);
2651 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2654 struct irq_chip *chip;
2658 chip = irq_data_get_irq_chip(data);
2659 if (chip->irq_get_irqchip_state)
2661 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2662 data = data->parent_data;
2669 err = chip->irq_get_irqchip_state(data, which, state);
2674 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2675 * @irq: Interrupt line that is forwarded to a VM
2676 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2677 * @state: a pointer to a boolean where the state is to be storeed
2679 * This call snapshots the internal irqchip state of an
2680 * interrupt, returning into @state the bit corresponding to
2683 * This function should be called with preemption disabled if the
2684 * interrupt controller has per-cpu registers.
2686 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2689 struct irq_desc *desc;
2690 struct irq_data *data;
2691 unsigned long flags;
2694 desc = irq_get_desc_buslock(irq, &flags, 0);
2698 data = irq_desc_get_irq_data(desc);
2700 err = __irq_get_irqchip_state(data, which, state);
2702 irq_put_desc_busunlock(desc, flags);
2705 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2708 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2709 * @irq: Interrupt line that is forwarded to a VM
2710 * @which: State to be restored (one of IRQCHIP_STATE_*)
2711 * @val: Value corresponding to @which
2713 * This call sets the internal irqchip state of an interrupt,
2714 * depending on the value of @which.
2716 * This function should be called with preemption disabled if the
2717 * interrupt controller has per-cpu registers.
2719 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2722 struct irq_desc *desc;
2723 struct irq_data *data;
2724 struct irq_chip *chip;
2725 unsigned long flags;
2728 desc = irq_get_desc_buslock(irq, &flags, 0);
2732 data = irq_desc_get_irq_data(desc);
2735 chip = irq_data_get_irq_chip(data);
2736 if (chip->irq_set_irqchip_state)
2738 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2739 data = data->parent_data;
2746 err = chip->irq_set_irqchip_state(data, which, val);
2748 irq_put_desc_busunlock(desc, flags);
2751 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);