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));
487 * Called when a bogus affinity is set via /proc/irq
489 int irq_select_affinity_usr(unsigned int irq)
491 struct irq_desc *desc = irq_to_desc(irq);
495 raw_spin_lock_irqsave(&desc->lock, flags);
496 ret = irq_setup_affinity(desc);
497 raw_spin_unlock_irqrestore(&desc->lock, flags);
503 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
504 * @irq: interrupt number to set affinity
505 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
506 * specific data for percpu_devid interrupts
508 * This function uses the vCPU specific data to set the vCPU
509 * affinity for an irq. The vCPU specific data is passed from
510 * outside, such as KVM. One example code path is as below:
511 * KVM -> IOMMU -> irq_set_vcpu_affinity().
513 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
516 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
517 struct irq_data *data;
518 struct irq_chip *chip;
524 data = irq_desc_get_irq_data(desc);
526 chip = irq_data_get_irq_chip(data);
527 if (chip && chip->irq_set_vcpu_affinity)
529 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
530 data = data->parent_data;
537 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
538 irq_put_desc_unlock(desc, flags);
542 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
544 void __disable_irq(struct irq_desc *desc)
550 static int __disable_irq_nosync(unsigned int irq)
553 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
558 irq_put_desc_busunlock(desc, flags);
563 * disable_irq_nosync - disable an irq without waiting
564 * @irq: Interrupt to disable
566 * Disable the selected interrupt line. Disables and Enables are
568 * Unlike disable_irq(), this function does not ensure existing
569 * instances of the IRQ handler have completed before returning.
571 * This function may be called from IRQ context.
573 void disable_irq_nosync(unsigned int irq)
575 __disable_irq_nosync(irq);
577 EXPORT_SYMBOL(disable_irq_nosync);
580 * disable_irq - disable an irq and wait for completion
581 * @irq: Interrupt to disable
583 * Disable the selected interrupt line. Enables and Disables are
585 * This function waits for any pending IRQ handlers for this interrupt
586 * to complete before returning. If you use this function while
587 * holding a resource the IRQ handler may need you will deadlock.
589 * This function may be called - with care - from IRQ context.
591 void disable_irq(unsigned int irq)
593 if (!__disable_irq_nosync(irq))
594 synchronize_irq(irq);
596 EXPORT_SYMBOL(disable_irq);
599 * disable_hardirq - disables an irq and waits for hardirq completion
600 * @irq: Interrupt to disable
602 * Disable the selected interrupt line. Enables and Disables are
604 * This function waits for any pending hard IRQ handlers for this
605 * interrupt to complete before returning. If you use this function while
606 * holding a resource the hard IRQ handler may need you will deadlock.
608 * When used to optimistically disable an interrupt from atomic context
609 * the return value must be checked.
611 * Returns: false if a threaded handler is active.
613 * This function may be called - with care - from IRQ context.
615 bool disable_hardirq(unsigned int irq)
617 if (!__disable_irq_nosync(irq))
618 return synchronize_hardirq(irq);
622 EXPORT_SYMBOL_GPL(disable_hardirq);
625 * disable_nmi_nosync - disable an nmi without waiting
626 * @irq: Interrupt to disable
628 * Disable the selected interrupt line. Disables and enables are
630 * The interrupt to disable must have been requested through request_nmi.
631 * Unlike disable_nmi(), this function does not ensure existing
632 * instances of the IRQ handler have completed before returning.
634 void disable_nmi_nosync(unsigned int irq)
636 disable_irq_nosync(irq);
639 void __enable_irq(struct irq_desc *desc)
641 switch (desc->depth) {
644 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
645 irq_desc_get_irq(desc));
648 if (desc->istate & IRQS_SUSPENDED)
650 /* Prevent probing on this irq: */
651 irq_settings_set_noprobe(desc);
653 * Call irq_startup() not irq_enable() here because the
654 * interrupt might be marked NOAUTOEN. So irq_startup()
655 * needs to be invoked when it gets enabled the first
656 * time. If it was already started up, then irq_startup()
657 * will invoke irq_enable() under the hood.
659 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
668 * enable_irq - enable handling of an irq
669 * @irq: Interrupt to enable
671 * Undoes the effect of one call to disable_irq(). If this
672 * matches the last disable, processing of interrupts on this
673 * IRQ line is re-enabled.
675 * This function may be called from IRQ context only when
676 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
678 void enable_irq(unsigned int irq)
681 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
685 if (WARN(!desc->irq_data.chip,
686 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
691 irq_put_desc_busunlock(desc, flags);
693 EXPORT_SYMBOL(enable_irq);
696 * enable_nmi - enable handling of an nmi
697 * @irq: Interrupt to enable
699 * The interrupt to enable must have been requested through request_nmi.
700 * Undoes the effect of one call to disable_nmi(). If this
701 * matches the last disable, processing of interrupts on this
702 * IRQ line is re-enabled.
704 void enable_nmi(unsigned int irq)
709 static int set_irq_wake_real(unsigned int irq, unsigned int on)
711 struct irq_desc *desc = irq_to_desc(irq);
714 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
717 if (desc->irq_data.chip->irq_set_wake)
718 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
724 * irq_set_irq_wake - control irq power management wakeup
725 * @irq: interrupt to control
726 * @on: enable/disable power management wakeup
728 * Enable/disable power management wakeup mode, which is
729 * disabled by default. Enables and disables must match,
730 * just as they match for non-wakeup mode support.
732 * Wakeup mode lets this IRQ wake the system from sleep
733 * states like "suspend to RAM".
735 int irq_set_irq_wake(unsigned int irq, unsigned int on)
738 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
744 /* Don't use NMIs as wake up interrupts please */
745 if (desc->istate & IRQS_NMI) {
750 /* wakeup-capable irqs can be shared between drivers that
751 * don't need to have the same sleep mode behaviors.
754 if (desc->wake_depth++ == 0) {
755 ret = set_irq_wake_real(irq, on);
757 desc->wake_depth = 0;
759 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
762 if (desc->wake_depth == 0) {
763 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
764 } else if (--desc->wake_depth == 0) {
765 ret = set_irq_wake_real(irq, on);
767 desc->wake_depth = 1;
769 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
774 irq_put_desc_busunlock(desc, flags);
777 EXPORT_SYMBOL(irq_set_irq_wake);
780 * Internal function that tells the architecture code whether a
781 * particular irq has been exclusively allocated or is available
784 int can_request_irq(unsigned int irq, unsigned long irqflags)
787 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
793 if (irq_settings_can_request(desc)) {
795 irqflags & desc->action->flags & IRQF_SHARED)
798 irq_put_desc_unlock(desc, flags);
802 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
804 struct irq_chip *chip = desc->irq_data.chip;
807 if (!chip || !chip->irq_set_type) {
809 * IRQF_TRIGGER_* but the PIC does not support multiple
812 pr_debug("No set_type function for IRQ %d (%s)\n",
813 irq_desc_get_irq(desc),
814 chip ? (chip->name ? : "unknown") : "unknown");
818 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
819 if (!irqd_irq_masked(&desc->irq_data))
821 if (!irqd_irq_disabled(&desc->irq_data))
825 /* Mask all flags except trigger mode */
826 flags &= IRQ_TYPE_SENSE_MASK;
827 ret = chip->irq_set_type(&desc->irq_data, flags);
830 case IRQ_SET_MASK_OK:
831 case IRQ_SET_MASK_OK_DONE:
832 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
833 irqd_set(&desc->irq_data, flags);
836 case IRQ_SET_MASK_OK_NOCOPY:
837 flags = irqd_get_trigger_type(&desc->irq_data);
838 irq_settings_set_trigger_mask(desc, flags);
839 irqd_clear(&desc->irq_data, IRQD_LEVEL);
840 irq_settings_clr_level(desc);
841 if (flags & IRQ_TYPE_LEVEL_MASK) {
842 irq_settings_set_level(desc);
843 irqd_set(&desc->irq_data, IRQD_LEVEL);
849 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
850 flags, irq_desc_get_irq(desc), chip->irq_set_type);
857 #ifdef CONFIG_HARDIRQS_SW_RESEND
858 int irq_set_parent(int irq, int parent_irq)
861 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
866 desc->parent_irq = parent_irq;
868 irq_put_desc_unlock(desc, flags);
871 EXPORT_SYMBOL_GPL(irq_set_parent);
875 * Default primary interrupt handler for threaded interrupts. Is
876 * assigned as primary handler when request_threaded_irq is called
877 * with handler == NULL. Useful for oneshot interrupts.
879 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
881 return IRQ_WAKE_THREAD;
885 * Primary handler for nested threaded interrupts. Should never be
888 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
890 WARN(1, "Primary handler called for nested irq %d\n", irq);
894 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
896 WARN(1, "Secondary action handler called for irq %d\n", irq);
900 static int irq_wait_for_interrupt(struct irqaction *action)
903 set_current_state(TASK_INTERRUPTIBLE);
905 if (kthread_should_stop()) {
906 /* may need to run one last time */
907 if (test_and_clear_bit(IRQTF_RUNTHREAD,
908 &action->thread_flags)) {
909 __set_current_state(TASK_RUNNING);
912 __set_current_state(TASK_RUNNING);
916 if (test_and_clear_bit(IRQTF_RUNTHREAD,
917 &action->thread_flags)) {
918 __set_current_state(TASK_RUNNING);
926 * Oneshot interrupts keep the irq line masked until the threaded
927 * handler finished. unmask if the interrupt has not been disabled and
930 static void irq_finalize_oneshot(struct irq_desc *desc,
931 struct irqaction *action)
933 if (!(desc->istate & IRQS_ONESHOT) ||
934 action->handler == irq_forced_secondary_handler)
938 raw_spin_lock_irq(&desc->lock);
941 * Implausible though it may be we need to protect us against
942 * the following scenario:
944 * The thread is faster done than the hard interrupt handler
945 * on the other CPU. If we unmask the irq line then the
946 * interrupt can come in again and masks the line, leaves due
947 * to IRQS_INPROGRESS and the irq line is masked forever.
949 * This also serializes the state of shared oneshot handlers
950 * versus "desc->threads_onehsot |= action->thread_mask;" in
951 * irq_wake_thread(). See the comment there which explains the
954 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
955 raw_spin_unlock_irq(&desc->lock);
956 chip_bus_sync_unlock(desc);
962 * Now check again, whether the thread should run. Otherwise
963 * we would clear the threads_oneshot bit of this thread which
966 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
969 desc->threads_oneshot &= ~action->thread_mask;
971 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
972 irqd_irq_masked(&desc->irq_data))
973 unmask_threaded_irq(desc);
976 raw_spin_unlock_irq(&desc->lock);
977 chip_bus_sync_unlock(desc);
982 * Check whether we need to change the affinity of the interrupt thread.
985 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
990 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
994 * In case we are out of memory we set IRQTF_AFFINITY again and
995 * try again next time
997 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
998 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1002 raw_spin_lock_irq(&desc->lock);
1004 * This code is triggered unconditionally. Check the affinity
1005 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1007 if (cpumask_available(desc->irq_common_data.affinity)) {
1008 const struct cpumask *m;
1010 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1011 cpumask_copy(mask, m);
1015 raw_spin_unlock_irq(&desc->lock);
1018 set_cpus_allowed_ptr(current, mask);
1019 free_cpumask_var(mask);
1023 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1027 * Interrupts which are not explicitly requested as threaded
1028 * interrupts rely on the implicit bh/preempt disable of the hard irq
1029 * context. So we need to disable bh here to avoid deadlocks and other
1033 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1038 ret = action->thread_fn(action->irq, action->dev_id);
1039 if (ret == IRQ_HANDLED)
1040 atomic_inc(&desc->threads_handled);
1042 irq_finalize_oneshot(desc, action);
1048 * Interrupts explicitly requested as threaded interrupts want to be
1049 * preemtible - many of them need to sleep and wait for slow busses to
1052 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1053 struct irqaction *action)
1057 ret = action->thread_fn(action->irq, action->dev_id);
1058 if (ret == IRQ_HANDLED)
1059 atomic_inc(&desc->threads_handled);
1061 irq_finalize_oneshot(desc, action);
1065 static void wake_threads_waitq(struct irq_desc *desc)
1067 if (atomic_dec_and_test(&desc->threads_active))
1068 wake_up(&desc->wait_for_threads);
1071 static void irq_thread_dtor(struct callback_head *unused)
1073 struct task_struct *tsk = current;
1074 struct irq_desc *desc;
1075 struct irqaction *action;
1077 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1080 action = kthread_data(tsk);
1082 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1083 tsk->comm, tsk->pid, action->irq);
1086 desc = irq_to_desc(action->irq);
1088 * If IRQTF_RUNTHREAD is set, we need to decrement
1089 * desc->threads_active and wake possible waiters.
1091 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1092 wake_threads_waitq(desc);
1094 /* Prevent a stale desc->threads_oneshot */
1095 irq_finalize_oneshot(desc, action);
1098 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1100 struct irqaction *secondary = action->secondary;
1102 if (WARN_ON_ONCE(!secondary))
1105 raw_spin_lock_irq(&desc->lock);
1106 __irq_wake_thread(desc, secondary);
1107 raw_spin_unlock_irq(&desc->lock);
1111 * Interrupt handler thread
1113 static int irq_thread(void *data)
1115 struct callback_head on_exit_work;
1116 struct irqaction *action = data;
1117 struct irq_desc *desc = irq_to_desc(action->irq);
1118 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1119 struct irqaction *action);
1121 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1122 &action->thread_flags))
1123 handler_fn = irq_forced_thread_fn;
1125 handler_fn = irq_thread_fn;
1127 init_task_work(&on_exit_work, irq_thread_dtor);
1128 task_work_add(current, &on_exit_work, false);
1130 irq_thread_check_affinity(desc, action);
1132 while (!irq_wait_for_interrupt(action)) {
1133 irqreturn_t action_ret;
1135 irq_thread_check_affinity(desc, action);
1137 action_ret = handler_fn(desc, action);
1138 if (action_ret == IRQ_WAKE_THREAD)
1139 irq_wake_secondary(desc, action);
1141 wake_threads_waitq(desc);
1145 * This is the regular exit path. __free_irq() is stopping the
1146 * thread via kthread_stop() after calling
1147 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1148 * oneshot mask bit can be set.
1150 task_work_cancel(current, irq_thread_dtor);
1155 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1156 * @irq: Interrupt line
1157 * @dev_id: Device identity for which the thread should be woken
1160 void irq_wake_thread(unsigned int irq, void *dev_id)
1162 struct irq_desc *desc = irq_to_desc(irq);
1163 struct irqaction *action;
1164 unsigned long flags;
1166 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1169 raw_spin_lock_irqsave(&desc->lock, flags);
1170 for_each_action_of_desc(desc, action) {
1171 if (action->dev_id == dev_id) {
1173 __irq_wake_thread(desc, action);
1177 raw_spin_unlock_irqrestore(&desc->lock, flags);
1179 EXPORT_SYMBOL_GPL(irq_wake_thread);
1181 static int irq_setup_forced_threading(struct irqaction *new)
1183 if (!force_irqthreads)
1185 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1189 * No further action required for interrupts which are requested as
1190 * threaded interrupts already
1192 if (new->handler == irq_default_primary_handler)
1195 new->flags |= IRQF_ONESHOT;
1198 * Handle the case where we have a real primary handler and a
1199 * thread handler. We force thread them as well by creating a
1202 if (new->handler && new->thread_fn) {
1203 /* Allocate the secondary action */
1204 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1205 if (!new->secondary)
1207 new->secondary->handler = irq_forced_secondary_handler;
1208 new->secondary->thread_fn = new->thread_fn;
1209 new->secondary->dev_id = new->dev_id;
1210 new->secondary->irq = new->irq;
1211 new->secondary->name = new->name;
1213 /* Deal with the primary handler */
1214 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1215 new->thread_fn = new->handler;
1216 new->handler = irq_default_primary_handler;
1220 static int irq_request_resources(struct irq_desc *desc)
1222 struct irq_data *d = &desc->irq_data;
1223 struct irq_chip *c = d->chip;
1225 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1228 static void irq_release_resources(struct irq_desc *desc)
1230 struct irq_data *d = &desc->irq_data;
1231 struct irq_chip *c = d->chip;
1233 if (c->irq_release_resources)
1234 c->irq_release_resources(d);
1237 static bool irq_supports_nmi(struct irq_desc *desc)
1239 struct irq_data *d = irq_desc_get_irq_data(desc);
1241 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1242 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1246 /* Don't support NMIs for chips behind a slow bus */
1247 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1250 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1253 static int irq_nmi_setup(struct irq_desc *desc)
1255 struct irq_data *d = irq_desc_get_irq_data(desc);
1256 struct irq_chip *c = d->chip;
1258 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1261 static void irq_nmi_teardown(struct irq_desc *desc)
1263 struct irq_data *d = irq_desc_get_irq_data(desc);
1264 struct irq_chip *c = d->chip;
1266 if (c->irq_nmi_teardown)
1267 c->irq_nmi_teardown(d);
1271 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1273 struct task_struct *t;
1274 struct sched_param param = {
1275 .sched_priority = MAX_USER_RT_PRIO/2,
1279 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1282 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1284 param.sched_priority -= 1;
1290 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1293 * We keep the reference to the task struct even if
1294 * the thread dies to avoid that the interrupt code
1295 * references an already freed task_struct.
1297 new->thread = get_task_struct(t);
1299 * Tell the thread to set its affinity. This is
1300 * important for shared interrupt handlers as we do
1301 * not invoke setup_affinity() for the secondary
1302 * handlers as everything is already set up. Even for
1303 * interrupts marked with IRQF_NO_BALANCE this is
1304 * correct as we want the thread to move to the cpu(s)
1305 * on which the requesting code placed the interrupt.
1307 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1312 * Internal function to register an irqaction - typically used to
1313 * allocate special interrupts that are part of the architecture.
1317 * desc->request_mutex Provides serialization against a concurrent free_irq()
1318 * chip_bus_lock Provides serialization for slow bus operations
1319 * desc->lock Provides serialization against hard interrupts
1321 * chip_bus_lock and desc->lock are sufficient for all other management and
1322 * interrupt related functions. desc->request_mutex solely serializes
1323 * request/free_irq().
1326 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1328 struct irqaction *old, **old_ptr;
1329 unsigned long flags, thread_mask = 0;
1330 int ret, nested, shared = 0;
1335 if (desc->irq_data.chip == &no_irq_chip)
1337 if (!try_module_get(desc->owner))
1343 * If the trigger type is not specified by the caller,
1344 * then use the default for this interrupt.
1346 if (!(new->flags & IRQF_TRIGGER_MASK))
1347 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1350 * Check whether the interrupt nests into another interrupt
1353 nested = irq_settings_is_nested_thread(desc);
1355 if (!new->thread_fn) {
1360 * Replace the primary handler which was provided from
1361 * the driver for non nested interrupt handling by the
1362 * dummy function which warns when called.
1364 new->handler = irq_nested_primary_handler;
1366 if (irq_settings_can_thread(desc)) {
1367 ret = irq_setup_forced_threading(new);
1374 * Create a handler thread when a thread function is supplied
1375 * and the interrupt does not nest into another interrupt
1378 if (new->thread_fn && !nested) {
1379 ret = setup_irq_thread(new, irq, false);
1382 if (new->secondary) {
1383 ret = setup_irq_thread(new->secondary, irq, true);
1390 * Drivers are often written to work w/o knowledge about the
1391 * underlying irq chip implementation, so a request for a
1392 * threaded irq without a primary hard irq context handler
1393 * requires the ONESHOT flag to be set. Some irq chips like
1394 * MSI based interrupts are per se one shot safe. Check the
1395 * chip flags, so we can avoid the unmask dance at the end of
1396 * the threaded handler for those.
1398 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1399 new->flags &= ~IRQF_ONESHOT;
1402 * Protects against a concurrent __free_irq() call which might wait
1403 * for synchronize_hardirq() to complete without holding the optional
1404 * chip bus lock and desc->lock. Also protects against handing out
1405 * a recycled oneshot thread_mask bit while it's still in use by
1406 * its previous owner.
1408 mutex_lock(&desc->request_mutex);
1411 * Acquire bus lock as the irq_request_resources() callback below
1412 * might rely on the serialization or the magic power management
1413 * functions which are abusing the irq_bus_lock() callback,
1415 chip_bus_lock(desc);
1417 /* First installed action requests resources. */
1418 if (!desc->action) {
1419 ret = irq_request_resources(desc);
1421 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1422 new->name, irq, desc->irq_data.chip->name);
1423 goto out_bus_unlock;
1428 * The following block of code has to be executed atomically
1429 * protected against a concurrent interrupt and any of the other
1430 * management calls which are not serialized via
1431 * desc->request_mutex or the optional bus lock.
1433 raw_spin_lock_irqsave(&desc->lock, flags);
1434 old_ptr = &desc->action;
1438 * Can't share interrupts unless both agree to and are
1439 * the same type (level, edge, polarity). So both flag
1440 * fields must have IRQF_SHARED set and the bits which
1441 * set the trigger type must match. Also all must
1443 * Interrupt lines used for NMIs cannot be shared.
1445 unsigned int oldtype;
1447 if (desc->istate & IRQS_NMI) {
1448 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1449 new->name, irq, desc->irq_data.chip->name);
1455 * If nobody did set the configuration before, inherit
1456 * the one provided by the requester.
1458 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1459 oldtype = irqd_get_trigger_type(&desc->irq_data);
1461 oldtype = new->flags & IRQF_TRIGGER_MASK;
1462 irqd_set_trigger_type(&desc->irq_data, oldtype);
1465 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1466 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1467 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1470 /* All handlers must agree on per-cpuness */
1471 if ((old->flags & IRQF_PERCPU) !=
1472 (new->flags & IRQF_PERCPU))
1475 /* add new interrupt at end of irq queue */
1478 * Or all existing action->thread_mask bits,
1479 * so we can find the next zero bit for this
1482 thread_mask |= old->thread_mask;
1483 old_ptr = &old->next;
1490 * Setup the thread mask for this irqaction for ONESHOT. For
1491 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1492 * conditional in irq_wake_thread().
1494 if (new->flags & IRQF_ONESHOT) {
1496 * Unlikely to have 32 resp 64 irqs sharing one line,
1499 if (thread_mask == ~0UL) {
1504 * The thread_mask for the action is or'ed to
1505 * desc->thread_active to indicate that the
1506 * IRQF_ONESHOT thread handler has been woken, but not
1507 * yet finished. The bit is cleared when a thread
1508 * completes. When all threads of a shared interrupt
1509 * line have completed desc->threads_active becomes
1510 * zero and the interrupt line is unmasked. See
1511 * handle.c:irq_wake_thread() for further information.
1513 * If no thread is woken by primary (hard irq context)
1514 * interrupt handlers, then desc->threads_active is
1515 * also checked for zero to unmask the irq line in the
1516 * affected hard irq flow handlers
1517 * (handle_[fasteoi|level]_irq).
1519 * The new action gets the first zero bit of
1520 * thread_mask assigned. See the loop above which or's
1521 * all existing action->thread_mask bits.
1523 new->thread_mask = 1UL << ffz(thread_mask);
1525 } else if (new->handler == irq_default_primary_handler &&
1526 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1528 * The interrupt was requested with handler = NULL, so
1529 * we use the default primary handler for it. But it
1530 * does not have the oneshot flag set. In combination
1531 * with level interrupts this is deadly, because the
1532 * default primary handler just wakes the thread, then
1533 * the irq lines is reenabled, but the device still
1534 * has the level irq asserted. Rinse and repeat....
1536 * While this works for edge type interrupts, we play
1537 * it safe and reject unconditionally because we can't
1538 * say for sure which type this interrupt really
1539 * has. The type flags are unreliable as the
1540 * underlying chip implementation can override them.
1542 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1549 init_waitqueue_head(&desc->wait_for_threads);
1551 /* Setup the type (level, edge polarity) if configured: */
1552 if (new->flags & IRQF_TRIGGER_MASK) {
1553 ret = __irq_set_trigger(desc,
1554 new->flags & IRQF_TRIGGER_MASK);
1561 * Activate the interrupt. That activation must happen
1562 * independently of IRQ_NOAUTOEN. request_irq() can fail
1563 * and the callers are supposed to handle
1564 * that. enable_irq() of an interrupt requested with
1565 * IRQ_NOAUTOEN is not supposed to fail. The activation
1566 * keeps it in shutdown mode, it merily associates
1567 * resources if necessary and if that's not possible it
1568 * fails. Interrupts which are in managed shutdown mode
1569 * will simply ignore that activation request.
1571 ret = irq_activate(desc);
1575 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1576 IRQS_ONESHOT | IRQS_WAITING);
1577 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1579 if (new->flags & IRQF_PERCPU) {
1580 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1581 irq_settings_set_per_cpu(desc);
1584 if (new->flags & IRQF_ONESHOT)
1585 desc->istate |= IRQS_ONESHOT;
1587 /* Exclude IRQ from balancing if requested */
1588 if (new->flags & IRQF_NOBALANCING) {
1589 irq_settings_set_no_balancing(desc);
1590 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1593 if (irq_settings_can_autoenable(desc)) {
1594 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1597 * Shared interrupts do not go well with disabling
1598 * auto enable. The sharing interrupt might request
1599 * it while it's still disabled and then wait for
1600 * interrupts forever.
1602 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1603 /* Undo nested disables: */
1607 } else if (new->flags & IRQF_TRIGGER_MASK) {
1608 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1609 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1612 /* hope the handler works with current trigger mode */
1613 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1619 irq_pm_install_action(desc, new);
1621 /* Reset broken irq detection when installing new handler */
1622 desc->irq_count = 0;
1623 desc->irqs_unhandled = 0;
1626 * Check whether we disabled the irq via the spurious handler
1627 * before. Reenable it and give it another chance.
1629 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1630 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1634 raw_spin_unlock_irqrestore(&desc->lock, flags);
1635 chip_bus_sync_unlock(desc);
1636 mutex_unlock(&desc->request_mutex);
1638 irq_setup_timings(desc, new);
1641 * Strictly no need to wake it up, but hung_task complains
1642 * when no hard interrupt wakes the thread up.
1645 wake_up_process(new->thread);
1647 wake_up_process(new->secondary->thread);
1649 register_irq_proc(irq, desc);
1651 register_handler_proc(irq, new);
1655 if (!(new->flags & IRQF_PROBE_SHARED)) {
1656 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1657 irq, new->flags, new->name, old->flags, old->name);
1658 #ifdef CONFIG_DEBUG_SHIRQ
1665 raw_spin_unlock_irqrestore(&desc->lock, flags);
1668 irq_release_resources(desc);
1670 chip_bus_sync_unlock(desc);
1671 mutex_unlock(&desc->request_mutex);
1675 struct task_struct *t = new->thread;
1681 if (new->secondary && new->secondary->thread) {
1682 struct task_struct *t = new->secondary->thread;
1684 new->secondary->thread = NULL;
1689 module_put(desc->owner);
1694 * setup_irq - setup an interrupt
1695 * @irq: Interrupt line to setup
1696 * @act: irqaction for the interrupt
1698 * Used to statically setup interrupts in the early boot process.
1700 int setup_irq(unsigned int irq, struct irqaction *act)
1703 struct irq_desc *desc = irq_to_desc(irq);
1705 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1708 retval = irq_chip_pm_get(&desc->irq_data);
1712 retval = __setup_irq(irq, desc, act);
1715 irq_chip_pm_put(&desc->irq_data);
1719 EXPORT_SYMBOL_GPL(setup_irq);
1722 * Internal function to unregister an irqaction - used to free
1723 * regular and special interrupts that are part of the architecture.
1725 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1727 unsigned irq = desc->irq_data.irq;
1728 struct irqaction *action, **action_ptr;
1729 unsigned long flags;
1731 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1733 mutex_lock(&desc->request_mutex);
1734 chip_bus_lock(desc);
1735 raw_spin_lock_irqsave(&desc->lock, flags);
1738 * There can be multiple actions per IRQ descriptor, find the right
1739 * one based on the dev_id:
1741 action_ptr = &desc->action;
1743 action = *action_ptr;
1746 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1747 raw_spin_unlock_irqrestore(&desc->lock, flags);
1748 chip_bus_sync_unlock(desc);
1749 mutex_unlock(&desc->request_mutex);
1753 if (action->dev_id == dev_id)
1755 action_ptr = &action->next;
1758 /* Found it - now remove it from the list of entries: */
1759 *action_ptr = action->next;
1761 irq_pm_remove_action(desc, action);
1763 /* If this was the last handler, shut down the IRQ line: */
1764 if (!desc->action) {
1765 irq_settings_clr_disable_unlazy(desc);
1766 /* Only shutdown. Deactivate after synchronize_hardirq() */
1771 /* make sure affinity_hint is cleaned up */
1772 if (WARN_ON_ONCE(desc->affinity_hint))
1773 desc->affinity_hint = NULL;
1776 raw_spin_unlock_irqrestore(&desc->lock, flags);
1778 * Drop bus_lock here so the changes which were done in the chip
1779 * callbacks above are synced out to the irq chips which hang
1780 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1782 * Aside of that the bus_lock can also be taken from the threaded
1783 * handler in irq_finalize_oneshot() which results in a deadlock
1784 * because kthread_stop() would wait forever for the thread to
1785 * complete, which is blocked on the bus lock.
1787 * The still held desc->request_mutex() protects against a
1788 * concurrent request_irq() of this irq so the release of resources
1789 * and timing data is properly serialized.
1791 chip_bus_sync_unlock(desc);
1793 unregister_handler_proc(irq, action);
1796 * Make sure it's not being used on another CPU and if the chip
1797 * supports it also make sure that there is no (not yet serviced)
1798 * interrupt in flight at the hardware level.
1800 __synchronize_hardirq(desc, true);
1802 #ifdef CONFIG_DEBUG_SHIRQ
1804 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1805 * event to happen even now it's being freed, so let's make sure that
1806 * is so by doing an extra call to the handler ....
1808 * ( We do this after actually deregistering it, to make sure that a
1809 * 'real' IRQ doesn't run in parallel with our fake. )
1811 if (action->flags & IRQF_SHARED) {
1812 local_irq_save(flags);
1813 action->handler(irq, dev_id);
1814 local_irq_restore(flags);
1819 * The action has already been removed above, but the thread writes
1820 * its oneshot mask bit when it completes. Though request_mutex is
1821 * held across this which prevents __setup_irq() from handing out
1822 * the same bit to a newly requested action.
1824 if (action->thread) {
1825 kthread_stop(action->thread);
1826 put_task_struct(action->thread);
1827 if (action->secondary && action->secondary->thread) {
1828 kthread_stop(action->secondary->thread);
1829 put_task_struct(action->secondary->thread);
1833 /* Last action releases resources */
1834 if (!desc->action) {
1836 * Reaquire bus lock as irq_release_resources() might
1837 * require it to deallocate resources over the slow bus.
1839 chip_bus_lock(desc);
1841 * There is no interrupt on the fly anymore. Deactivate it
1844 raw_spin_lock_irqsave(&desc->lock, flags);
1845 irq_domain_deactivate_irq(&desc->irq_data);
1846 raw_spin_unlock_irqrestore(&desc->lock, flags);
1848 irq_release_resources(desc);
1849 chip_bus_sync_unlock(desc);
1850 irq_remove_timings(desc);
1853 mutex_unlock(&desc->request_mutex);
1855 irq_chip_pm_put(&desc->irq_data);
1856 module_put(desc->owner);
1857 kfree(action->secondary);
1862 * remove_irq - free an interrupt
1863 * @irq: Interrupt line to free
1864 * @act: irqaction for the interrupt
1866 * Used to remove interrupts statically setup by the early boot process.
1868 void remove_irq(unsigned int irq, struct irqaction *act)
1870 struct irq_desc *desc = irq_to_desc(irq);
1872 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1873 __free_irq(desc, act->dev_id);
1875 EXPORT_SYMBOL_GPL(remove_irq);
1878 * free_irq - free an interrupt allocated with request_irq
1879 * @irq: Interrupt line to free
1880 * @dev_id: Device identity to free
1882 * Remove an interrupt handler. The handler is removed and if the
1883 * interrupt line is no longer in use by any driver it is disabled.
1884 * On a shared IRQ the caller must ensure the interrupt is disabled
1885 * on the card it drives before calling this function. The function
1886 * does not return until any executing interrupts for this IRQ
1889 * This function must not be called from interrupt context.
1891 * Returns the devname argument passed to request_irq.
1893 const void *free_irq(unsigned int irq, void *dev_id)
1895 struct irq_desc *desc = irq_to_desc(irq);
1896 struct irqaction *action;
1897 const char *devname;
1899 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1903 if (WARN_ON(desc->affinity_notify))
1904 desc->affinity_notify = NULL;
1907 action = __free_irq(desc, dev_id);
1912 devname = action->name;
1916 EXPORT_SYMBOL(free_irq);
1918 /* This function must be called with desc->lock held */
1919 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1921 const char *devname = NULL;
1923 desc->istate &= ~IRQS_NMI;
1925 if (!WARN_ON(desc->action == NULL)) {
1926 irq_pm_remove_action(desc, desc->action);
1927 devname = desc->action->name;
1928 unregister_handler_proc(irq, desc->action);
1930 kfree(desc->action);
1931 desc->action = NULL;
1934 irq_settings_clr_disable_unlazy(desc);
1935 irq_shutdown_and_deactivate(desc);
1937 irq_release_resources(desc);
1939 irq_chip_pm_put(&desc->irq_data);
1940 module_put(desc->owner);
1945 const void *free_nmi(unsigned int irq, void *dev_id)
1947 struct irq_desc *desc = irq_to_desc(irq);
1948 unsigned long flags;
1949 const void *devname;
1951 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1954 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1957 /* NMI still enabled */
1958 if (WARN_ON(desc->depth == 0))
1959 disable_nmi_nosync(irq);
1961 raw_spin_lock_irqsave(&desc->lock, flags);
1963 irq_nmi_teardown(desc);
1964 devname = __cleanup_nmi(irq, desc);
1966 raw_spin_unlock_irqrestore(&desc->lock, flags);
1972 * request_threaded_irq - allocate an interrupt line
1973 * @irq: Interrupt line to allocate
1974 * @handler: Function to be called when the IRQ occurs.
1975 * Primary handler for threaded interrupts
1976 * If NULL and thread_fn != NULL the default
1977 * primary handler is installed
1978 * @thread_fn: Function called from the irq handler thread
1979 * If NULL, no irq thread is created
1980 * @irqflags: Interrupt type flags
1981 * @devname: An ascii name for the claiming device
1982 * @dev_id: A cookie passed back to the handler function
1984 * This call allocates interrupt resources and enables the
1985 * interrupt line and IRQ handling. From the point this
1986 * call is made your handler function may be invoked. Since
1987 * your handler function must clear any interrupt the board
1988 * raises, you must take care both to initialise your hardware
1989 * and to set up the interrupt handler in the right order.
1991 * If you want to set up a threaded irq handler for your device
1992 * then you need to supply @handler and @thread_fn. @handler is
1993 * still called in hard interrupt context and has to check
1994 * whether the interrupt originates from the device. If yes it
1995 * needs to disable the interrupt on the device and return
1996 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1997 * @thread_fn. This split handler design is necessary to support
1998 * shared interrupts.
2000 * Dev_id must be globally unique. Normally the address of the
2001 * device data structure is used as the cookie. Since the handler
2002 * receives this value it makes sense to use it.
2004 * If your interrupt is shared you must pass a non NULL dev_id
2005 * as this is required when freeing the interrupt.
2009 * IRQF_SHARED Interrupt is shared
2010 * IRQF_TRIGGER_* Specify active edge(s) or level
2013 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2014 irq_handler_t thread_fn, unsigned long irqflags,
2015 const char *devname, void *dev_id)
2017 struct irqaction *action;
2018 struct irq_desc *desc;
2021 if (irq == IRQ_NOTCONNECTED)
2025 * Sanity-check: shared interrupts must pass in a real dev-ID,
2026 * otherwise we'll have trouble later trying to figure out
2027 * which interrupt is which (messes up the interrupt freeing
2030 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2031 * it cannot be set along with IRQF_NO_SUSPEND.
2033 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2034 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2035 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2038 desc = irq_to_desc(irq);
2042 if (!irq_settings_can_request(desc) ||
2043 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2049 handler = irq_default_primary_handler;
2052 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2056 action->handler = handler;
2057 action->thread_fn = thread_fn;
2058 action->flags = irqflags;
2059 action->name = devname;
2060 action->dev_id = dev_id;
2062 retval = irq_chip_pm_get(&desc->irq_data);
2068 retval = __setup_irq(irq, desc, action);
2071 irq_chip_pm_put(&desc->irq_data);
2072 kfree(action->secondary);
2076 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2077 if (!retval && (irqflags & IRQF_SHARED)) {
2079 * It's a shared IRQ -- the driver ought to be prepared for it
2080 * to happen immediately, so let's make sure....
2081 * We disable the irq to make sure that a 'real' IRQ doesn't
2082 * run in parallel with our fake.
2084 unsigned long flags;
2087 local_irq_save(flags);
2089 handler(irq, dev_id);
2091 local_irq_restore(flags);
2097 EXPORT_SYMBOL(request_threaded_irq);
2100 * request_any_context_irq - allocate an interrupt line
2101 * @irq: Interrupt line to allocate
2102 * @handler: Function to be called when the IRQ occurs.
2103 * Threaded handler for threaded interrupts.
2104 * @flags: Interrupt type flags
2105 * @name: An ascii name for the claiming device
2106 * @dev_id: A cookie passed back to the handler function
2108 * This call allocates interrupt resources and enables the
2109 * interrupt line and IRQ handling. It selects either a
2110 * hardirq or threaded handling method depending on the
2113 * On failure, it returns a negative value. On success,
2114 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2116 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2117 unsigned long flags, const char *name, void *dev_id)
2119 struct irq_desc *desc;
2122 if (irq == IRQ_NOTCONNECTED)
2125 desc = irq_to_desc(irq);
2129 if (irq_settings_is_nested_thread(desc)) {
2130 ret = request_threaded_irq(irq, NULL, handler,
2131 flags, name, dev_id);
2132 return !ret ? IRQC_IS_NESTED : ret;
2135 ret = request_irq(irq, handler, flags, name, dev_id);
2136 return !ret ? IRQC_IS_HARDIRQ : ret;
2138 EXPORT_SYMBOL_GPL(request_any_context_irq);
2141 * request_nmi - allocate an interrupt line for NMI delivery
2142 * @irq: Interrupt line to allocate
2143 * @handler: Function to be called when the IRQ occurs.
2144 * Threaded handler for threaded interrupts.
2145 * @irqflags: Interrupt type flags
2146 * @name: An ascii name for the claiming device
2147 * @dev_id: A cookie passed back to the handler function
2149 * This call allocates interrupt resources and enables the
2150 * interrupt line and IRQ handling. It sets up the IRQ line
2151 * to be handled as an NMI.
2153 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2154 * cannot be threaded.
2156 * Interrupt lines requested for NMI delivering must produce per cpu
2157 * interrupts and have auto enabling setting disabled.
2159 * Dev_id must be globally unique. Normally the address of the
2160 * device data structure is used as the cookie. Since the handler
2161 * receives this value it makes sense to use it.
2163 * If the interrupt line cannot be used to deliver NMIs, function
2164 * will fail and return a negative value.
2166 int request_nmi(unsigned int irq, irq_handler_t handler,
2167 unsigned long irqflags, const char *name, void *dev_id)
2169 struct irqaction *action;
2170 struct irq_desc *desc;
2171 unsigned long flags;
2174 if (irq == IRQ_NOTCONNECTED)
2177 /* NMI cannot be shared, used for Polling */
2178 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2181 if (!(irqflags & IRQF_PERCPU))
2187 desc = irq_to_desc(irq);
2189 if (!desc || irq_settings_can_autoenable(desc) ||
2190 !irq_settings_can_request(desc) ||
2191 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2192 !irq_supports_nmi(desc))
2195 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2199 action->handler = handler;
2200 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2201 action->name = name;
2202 action->dev_id = dev_id;
2204 retval = irq_chip_pm_get(&desc->irq_data);
2208 retval = __setup_irq(irq, desc, action);
2212 raw_spin_lock_irqsave(&desc->lock, flags);
2214 /* Setup NMI state */
2215 desc->istate |= IRQS_NMI;
2216 retval = irq_nmi_setup(desc);
2218 __cleanup_nmi(irq, desc);
2219 raw_spin_unlock_irqrestore(&desc->lock, flags);
2223 raw_spin_unlock_irqrestore(&desc->lock, flags);
2228 irq_chip_pm_put(&desc->irq_data);
2235 void enable_percpu_irq(unsigned int irq, unsigned int type)
2237 unsigned int cpu = smp_processor_id();
2238 unsigned long flags;
2239 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2245 * If the trigger type is not specified by the caller, then
2246 * use the default for this interrupt.
2248 type &= IRQ_TYPE_SENSE_MASK;
2249 if (type == IRQ_TYPE_NONE)
2250 type = irqd_get_trigger_type(&desc->irq_data);
2252 if (type != IRQ_TYPE_NONE) {
2255 ret = __irq_set_trigger(desc, type);
2258 WARN(1, "failed to set type for IRQ%d\n", irq);
2263 irq_percpu_enable(desc, cpu);
2265 irq_put_desc_unlock(desc, flags);
2267 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2269 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2271 enable_percpu_irq(irq, type);
2275 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2276 * @irq: Linux irq number to check for
2278 * Must be called from a non migratable context. Returns the enable
2279 * state of a per cpu interrupt on the current cpu.
2281 bool irq_percpu_is_enabled(unsigned int irq)
2283 unsigned int cpu = smp_processor_id();
2284 struct irq_desc *desc;
2285 unsigned long flags;
2288 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2292 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2293 irq_put_desc_unlock(desc, flags);
2297 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2299 void disable_percpu_irq(unsigned int irq)
2301 unsigned int cpu = smp_processor_id();
2302 unsigned long flags;
2303 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2308 irq_percpu_disable(desc, cpu);
2309 irq_put_desc_unlock(desc, flags);
2311 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2313 void disable_percpu_nmi(unsigned int irq)
2315 disable_percpu_irq(irq);
2319 * Internal function to unregister a percpu irqaction.
2321 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2323 struct irq_desc *desc = irq_to_desc(irq);
2324 struct irqaction *action;
2325 unsigned long flags;
2327 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2332 raw_spin_lock_irqsave(&desc->lock, flags);
2334 action = desc->action;
2335 if (!action || action->percpu_dev_id != dev_id) {
2336 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2340 if (!cpumask_empty(desc->percpu_enabled)) {
2341 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2342 irq, cpumask_first(desc->percpu_enabled));
2346 /* Found it - now remove it from the list of entries: */
2347 desc->action = NULL;
2349 desc->istate &= ~IRQS_NMI;
2351 raw_spin_unlock_irqrestore(&desc->lock, flags);
2353 unregister_handler_proc(irq, action);
2355 irq_chip_pm_put(&desc->irq_data);
2356 module_put(desc->owner);
2360 raw_spin_unlock_irqrestore(&desc->lock, flags);
2365 * remove_percpu_irq - free a per-cpu interrupt
2366 * @irq: Interrupt line to free
2367 * @act: irqaction for the interrupt
2369 * Used to remove interrupts statically setup by the early boot process.
2371 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2373 struct irq_desc *desc = irq_to_desc(irq);
2375 if (desc && irq_settings_is_per_cpu_devid(desc))
2376 __free_percpu_irq(irq, act->percpu_dev_id);
2380 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2381 * @irq: Interrupt line to free
2382 * @dev_id: Device identity to free
2384 * Remove a percpu interrupt handler. The handler is removed, but
2385 * the interrupt line is not disabled. This must be done on each
2386 * CPU before calling this function. The function does not return
2387 * until any executing interrupts for this IRQ have completed.
2389 * This function must not be called from interrupt context.
2391 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2393 struct irq_desc *desc = irq_to_desc(irq);
2395 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2398 chip_bus_lock(desc);
2399 kfree(__free_percpu_irq(irq, dev_id));
2400 chip_bus_sync_unlock(desc);
2402 EXPORT_SYMBOL_GPL(free_percpu_irq);
2404 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2406 struct irq_desc *desc = irq_to_desc(irq);
2408 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2411 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2414 kfree(__free_percpu_irq(irq, dev_id));
2418 * setup_percpu_irq - setup a per-cpu interrupt
2419 * @irq: Interrupt line to setup
2420 * @act: irqaction for the interrupt
2422 * Used to statically setup per-cpu interrupts in the early boot process.
2424 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2426 struct irq_desc *desc = irq_to_desc(irq);
2429 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2432 retval = irq_chip_pm_get(&desc->irq_data);
2436 retval = __setup_irq(irq, desc, act);
2439 irq_chip_pm_put(&desc->irq_data);
2445 * __request_percpu_irq - allocate a percpu interrupt line
2446 * @irq: Interrupt line to allocate
2447 * @handler: Function to be called when the IRQ occurs.
2448 * @flags: Interrupt type flags (IRQF_TIMER only)
2449 * @devname: An ascii name for the claiming device
2450 * @dev_id: A percpu cookie passed back to the handler function
2452 * This call allocates interrupt resources and enables the
2453 * interrupt on the local CPU. If the interrupt is supposed to be
2454 * enabled on other CPUs, it has to be done on each CPU using
2455 * enable_percpu_irq().
2457 * Dev_id must be globally unique. It is a per-cpu variable, and
2458 * the handler gets called with the interrupted CPU's instance of
2461 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2462 unsigned long flags, const char *devname,
2463 void __percpu *dev_id)
2465 struct irqaction *action;
2466 struct irq_desc *desc;
2472 desc = irq_to_desc(irq);
2473 if (!desc || !irq_settings_can_request(desc) ||
2474 !irq_settings_is_per_cpu_devid(desc))
2477 if (flags && flags != IRQF_TIMER)
2480 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2484 action->handler = handler;
2485 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2486 action->name = devname;
2487 action->percpu_dev_id = dev_id;
2489 retval = irq_chip_pm_get(&desc->irq_data);
2495 retval = __setup_irq(irq, desc, action);
2498 irq_chip_pm_put(&desc->irq_data);
2504 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2507 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2508 * @irq: Interrupt line to allocate
2509 * @handler: Function to be called when the IRQ occurs.
2510 * @name: An ascii name for the claiming device
2511 * @dev_id: A percpu cookie passed back to the handler function
2513 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2514 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2515 * being enabled on the same CPU by using enable_percpu_nmi().
2517 * Dev_id must be globally unique. It is a per-cpu variable, and
2518 * the handler gets called with the interrupted CPU's instance of
2521 * Interrupt lines requested for NMI delivering should have auto enabling
2524 * If the interrupt line cannot be used to deliver NMIs, function
2525 * will fail returning a negative value.
2527 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2528 const char *name, void __percpu *dev_id)
2530 struct irqaction *action;
2531 struct irq_desc *desc;
2532 unsigned long flags;
2538 desc = irq_to_desc(irq);
2540 if (!desc || !irq_settings_can_request(desc) ||
2541 !irq_settings_is_per_cpu_devid(desc) ||
2542 irq_settings_can_autoenable(desc) ||
2543 !irq_supports_nmi(desc))
2546 /* The line cannot already be NMI */
2547 if (desc->istate & IRQS_NMI)
2550 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2554 action->handler = handler;
2555 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2557 action->name = name;
2558 action->percpu_dev_id = dev_id;
2560 retval = irq_chip_pm_get(&desc->irq_data);
2564 retval = __setup_irq(irq, desc, action);
2568 raw_spin_lock_irqsave(&desc->lock, flags);
2569 desc->istate |= IRQS_NMI;
2570 raw_spin_unlock_irqrestore(&desc->lock, flags);
2575 irq_chip_pm_put(&desc->irq_data);
2583 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2584 * @irq: Interrupt line to prepare for NMI delivery
2586 * This call prepares an interrupt line to deliver NMI on the current CPU,
2587 * before that interrupt line gets enabled with enable_percpu_nmi().
2589 * As a CPU local operation, this should be called from non-preemptible
2592 * If the interrupt line cannot be used to deliver NMIs, function
2593 * will fail returning a negative value.
2595 int prepare_percpu_nmi(unsigned int irq)
2597 unsigned long flags;
2598 struct irq_desc *desc;
2601 WARN_ON(preemptible());
2603 desc = irq_get_desc_lock(irq, &flags,
2604 IRQ_GET_DESC_CHECK_PERCPU);
2608 if (WARN(!(desc->istate & IRQS_NMI),
2609 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2615 ret = irq_nmi_setup(desc);
2617 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2622 irq_put_desc_unlock(desc, flags);
2627 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2628 * @irq: Interrupt line from which CPU local NMI configuration should be
2631 * This call undoes the setup done by prepare_percpu_nmi().
2633 * IRQ line should not be enabled for the current CPU.
2635 * As a CPU local operation, this should be called from non-preemptible
2638 void teardown_percpu_nmi(unsigned int irq)
2640 unsigned long flags;
2641 struct irq_desc *desc;
2643 WARN_ON(preemptible());
2645 desc = irq_get_desc_lock(irq, &flags,
2646 IRQ_GET_DESC_CHECK_PERCPU);
2650 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2653 irq_nmi_teardown(desc);
2655 irq_put_desc_unlock(desc, flags);
2658 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2661 struct irq_chip *chip;
2665 chip = irq_data_get_irq_chip(data);
2666 if (chip->irq_get_irqchip_state)
2668 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2669 data = data->parent_data;
2676 err = chip->irq_get_irqchip_state(data, which, state);
2681 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2682 * @irq: Interrupt line that is forwarded to a VM
2683 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2684 * @state: a pointer to a boolean where the state is to be storeed
2686 * This call snapshots the internal irqchip state of an
2687 * interrupt, returning into @state the bit corresponding to
2690 * This function should be called with preemption disabled if the
2691 * interrupt controller has per-cpu registers.
2693 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2696 struct irq_desc *desc;
2697 struct irq_data *data;
2698 unsigned long flags;
2701 desc = irq_get_desc_buslock(irq, &flags, 0);
2705 data = irq_desc_get_irq_data(desc);
2707 err = __irq_get_irqchip_state(data, which, state);
2709 irq_put_desc_busunlock(desc, flags);
2712 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2715 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2716 * @irq: Interrupt line that is forwarded to a VM
2717 * @which: State to be restored (one of IRQCHIP_STATE_*)
2718 * @val: Value corresponding to @which
2720 * This call sets the internal irqchip state of an interrupt,
2721 * depending on the value of @which.
2723 * This function should be called with preemption disabled if the
2724 * interrupt controller has per-cpu registers.
2726 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2729 struct irq_desc *desc;
2730 struct irq_data *data;
2731 struct irq_chip *chip;
2732 unsigned long flags;
2735 desc = irq_get_desc_buslock(irq, &flags, 0);
2739 data = irq_desc_get_irq_data(desc);
2742 chip = irq_data_get_irq_chip(data);
2743 if (chip->irq_set_irqchip_state)
2745 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2746 data = data->parent_data;
2753 err = chip->irq_set_irqchip_state(data, which, val);
2755 irq_put_desc_busunlock(desc, flags);
2758 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);