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 affinity changed
184 * We just set IRQTF_AFFINITY and delegate the affinity setting
185 * to the interrupt thread itself. We can not call
186 * set_cpus_allowed_ptr() here as we hold desc->lock and this
187 * code can be called from hard interrupt context.
189 void irq_set_thread_affinity(struct irq_desc *desc)
191 struct irqaction *action;
193 for_each_action_of_desc(desc, action)
195 set_bit(IRQTF_AFFINITY, &action->thread_flags);
198 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
199 static void irq_validate_effective_affinity(struct irq_data *data)
201 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
202 struct irq_chip *chip = irq_data_get_irq_chip(data);
204 if (!cpumask_empty(m))
206 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
207 chip->name, data->irq);
210 static inline void irq_init_effective_affinity(struct irq_data *data,
211 const struct cpumask *mask)
213 cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
216 static inline void irq_validate_effective_affinity(struct irq_data *data) { }
217 static inline void irq_init_effective_affinity(struct irq_data *data,
218 const struct cpumask *mask) { }
221 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
224 struct irq_desc *desc = irq_data_to_desc(data);
225 struct irq_chip *chip = irq_data_get_irq_chip(data);
228 if (!chip || !chip->irq_set_affinity)
232 * If this is a managed interrupt and housekeeping is enabled on
233 * it check whether the requested affinity mask intersects with
234 * a housekeeping CPU. If so, then remove the isolated CPUs from
235 * the mask and just keep the housekeeping CPU(s). This prevents
236 * the affinity setter from routing the interrupt to an isolated
237 * CPU to avoid that I/O submitted from a housekeeping CPU causes
238 * interrupts on an isolated one.
240 * If the masks do not intersect or include online CPU(s) then
241 * keep the requested mask. The isolated target CPUs are only
242 * receiving interrupts when the I/O operation was submitted
243 * directly from them.
245 * If all housekeeping CPUs in the affinity mask are offline, the
246 * interrupt will be migrated by the CPU hotplug code once a
247 * housekeeping CPU which belongs to the affinity mask comes
250 if (irqd_affinity_is_managed(data) &&
251 housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
252 const struct cpumask *hk_mask, *prog_mask;
254 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
255 static struct cpumask tmp_mask;
257 hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
259 raw_spin_lock(&tmp_mask_lock);
260 cpumask_and(&tmp_mask, mask, hk_mask);
261 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
264 prog_mask = &tmp_mask;
265 ret = chip->irq_set_affinity(data, prog_mask, force);
266 raw_spin_unlock(&tmp_mask_lock);
268 ret = chip->irq_set_affinity(data, mask, force);
271 case IRQ_SET_MASK_OK:
272 case IRQ_SET_MASK_OK_DONE:
273 cpumask_copy(desc->irq_common_data.affinity, mask);
275 case IRQ_SET_MASK_OK_NOCOPY:
276 irq_validate_effective_affinity(data);
277 irq_set_thread_affinity(desc);
284 #ifdef CONFIG_GENERIC_PENDING_IRQ
285 static inline int irq_set_affinity_pending(struct irq_data *data,
286 const struct cpumask *dest)
288 struct irq_desc *desc = irq_data_to_desc(data);
290 irqd_set_move_pending(data);
291 irq_copy_pending(desc, dest);
295 static inline int irq_set_affinity_pending(struct irq_data *data,
296 const struct cpumask *dest)
302 static int irq_try_set_affinity(struct irq_data *data,
303 const struct cpumask *dest, bool force)
305 int ret = irq_do_set_affinity(data, dest, force);
308 * In case that the underlying vector management is busy and the
309 * architecture supports the generic pending mechanism then utilize
310 * this to avoid returning an error to user space.
312 if (ret == -EBUSY && !force)
313 ret = irq_set_affinity_pending(data, dest);
317 static bool irq_set_affinity_deactivated(struct irq_data *data,
318 const struct cpumask *mask, bool force)
320 struct irq_desc *desc = irq_data_to_desc(data);
323 * Handle irq chips which can handle affinity only in activated
326 * If the interrupt is not yet activated, just store the affinity
327 * mask and do not call the chip driver at all. On activation the
328 * driver has to make sure anyway that the interrupt is in a
329 * usable state so startup works.
331 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
332 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
335 cpumask_copy(desc->irq_common_data.affinity, mask);
336 irq_init_effective_affinity(data, mask);
337 irqd_set(data, IRQD_AFFINITY_SET);
341 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
344 struct irq_chip *chip = irq_data_get_irq_chip(data);
345 struct irq_desc *desc = irq_data_to_desc(data);
348 if (!chip || !chip->irq_set_affinity)
351 if (irq_set_affinity_deactivated(data, mask, force))
354 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
355 ret = irq_try_set_affinity(data, mask, force);
357 irqd_set_move_pending(data);
358 irq_copy_pending(desc, mask);
361 if (desc->affinity_notify) {
362 kref_get(&desc->affinity_notify->kref);
363 if (!schedule_work(&desc->affinity_notify->work)) {
364 /* Work was already scheduled, drop our extra ref */
365 kref_put(&desc->affinity_notify->kref,
366 desc->affinity_notify->release);
369 irqd_set(data, IRQD_AFFINITY_SET);
375 * irq_update_affinity_desc - Update affinity management for an interrupt
376 * @irq: The interrupt number to update
377 * @affinity: Pointer to the affinity descriptor
379 * This interface can be used to configure the affinity management of
380 * interrupts which have been allocated already.
382 * There are certain limitations on when it may be used - attempts to use it
383 * for when the kernel is configured for generic IRQ reservation mode (in
384 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
385 * managed/non-managed interrupt accounting. In addition, attempts to use it on
386 * an interrupt which is already started or which has already been configured
387 * as managed will also fail, as these mean invalid init state or double init.
389 int irq_update_affinity_desc(unsigned int irq,
390 struct irq_affinity_desc *affinity)
392 struct irq_desc *desc;
398 * Supporting this with the reservation scheme used by x86 needs
399 * some more thought. Fail it for now.
401 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
404 desc = irq_get_desc_buslock(irq, &flags, 0);
408 /* Requires the interrupt to be shut down */
409 if (irqd_is_started(&desc->irq_data)) {
414 /* Interrupts which are already managed cannot be modified */
415 if (irqd_affinity_is_managed(&desc->irq_data)) {
421 * Deactivate the interrupt. That's required to undo
422 * anything an earlier activation has established.
424 activated = irqd_is_activated(&desc->irq_data);
426 irq_domain_deactivate_irq(&desc->irq_data);
428 if (affinity->is_managed) {
429 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
430 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
433 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
435 /* Restore the activation state */
437 irq_domain_activate_irq(&desc->irq_data, false);
440 irq_put_desc_busunlock(desc, flags);
444 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
446 struct irq_desc *desc = irq_to_desc(irq);
453 raw_spin_lock_irqsave(&desc->lock, flags);
454 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
455 raw_spin_unlock_irqrestore(&desc->lock, flags);
459 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
462 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
466 desc->affinity_hint = m;
467 irq_put_desc_unlock(desc, flags);
468 /* set the initial affinity to prevent every interrupt being on CPU0 */
470 __irq_set_affinity(irq, m, false);
473 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
475 static void irq_affinity_notify(struct work_struct *work)
477 struct irq_affinity_notify *notify =
478 container_of(work, struct irq_affinity_notify, work);
479 struct irq_desc *desc = irq_to_desc(notify->irq);
480 cpumask_var_t cpumask;
483 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
486 raw_spin_lock_irqsave(&desc->lock, flags);
487 if (irq_move_pending(&desc->irq_data))
488 irq_get_pending(cpumask, desc);
490 cpumask_copy(cpumask, desc->irq_common_data.affinity);
491 raw_spin_unlock_irqrestore(&desc->lock, flags);
493 notify->notify(notify, cpumask);
495 free_cpumask_var(cpumask);
497 kref_put(¬ify->kref, notify->release);
501 * irq_set_affinity_notifier - control notification of IRQ affinity changes
502 * @irq: Interrupt for which to enable/disable notification
503 * @notify: Context for notification, or %NULL to disable
504 * notification. Function pointers must be initialised;
505 * the other fields will be initialised by this function.
507 * Must be called in process context. Notification may only be enabled
508 * after the IRQ is allocated and must be disabled before the IRQ is
509 * freed using free_irq().
512 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
514 struct irq_desc *desc = irq_to_desc(irq);
515 struct irq_affinity_notify *old_notify;
518 /* The release function is promised process context */
521 if (!desc || desc->istate & IRQS_NMI)
524 /* Complete initialisation of *notify */
527 kref_init(¬ify->kref);
528 INIT_WORK(¬ify->work, irq_affinity_notify);
531 raw_spin_lock_irqsave(&desc->lock, flags);
532 old_notify = desc->affinity_notify;
533 desc->affinity_notify = notify;
534 raw_spin_unlock_irqrestore(&desc->lock, flags);
537 if (cancel_work_sync(&old_notify->work)) {
538 /* Pending work had a ref, put that one too */
539 kref_put(&old_notify->kref, old_notify->release);
541 kref_put(&old_notify->kref, old_notify->release);
546 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
548 #ifndef CONFIG_AUTO_IRQ_AFFINITY
550 * Generic version of the affinity autoselector.
552 int irq_setup_affinity(struct irq_desc *desc)
554 struct cpumask *set = irq_default_affinity;
555 int ret, node = irq_desc_get_node(desc);
556 static DEFINE_RAW_SPINLOCK(mask_lock);
557 static struct cpumask mask;
559 /* Excludes PER_CPU and NO_BALANCE interrupts */
560 if (!__irq_can_set_affinity(desc))
563 raw_spin_lock(&mask_lock);
565 * Preserve the managed affinity setting and a userspace affinity
566 * setup, but make sure that one of the targets is online.
568 if (irqd_affinity_is_managed(&desc->irq_data) ||
569 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
570 if (cpumask_intersects(desc->irq_common_data.affinity,
572 set = desc->irq_common_data.affinity;
574 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
577 cpumask_and(&mask, cpu_online_mask, set);
578 if (cpumask_empty(&mask))
579 cpumask_copy(&mask, cpu_online_mask);
581 if (node != NUMA_NO_NODE) {
582 const struct cpumask *nodemask = cpumask_of_node(node);
584 /* make sure at least one of the cpus in nodemask is online */
585 if (cpumask_intersects(&mask, nodemask))
586 cpumask_and(&mask, &mask, nodemask);
588 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
589 raw_spin_unlock(&mask_lock);
593 /* Wrapper for ALPHA specific affinity selector magic */
594 int irq_setup_affinity(struct irq_desc *desc)
596 return irq_select_affinity(irq_desc_get_irq(desc));
598 #endif /* CONFIG_AUTO_IRQ_AFFINITY */
599 #endif /* CONFIG_SMP */
603 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
604 * @irq: interrupt number to set affinity
605 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
606 * specific data for percpu_devid interrupts
608 * This function uses the vCPU specific data to set the vCPU
609 * affinity for an irq. The vCPU specific data is passed from
610 * outside, such as KVM. One example code path is as below:
611 * KVM -> IOMMU -> irq_set_vcpu_affinity().
613 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
616 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
617 struct irq_data *data;
618 struct irq_chip *chip;
624 data = irq_desc_get_irq_data(desc);
626 chip = irq_data_get_irq_chip(data);
627 if (chip && chip->irq_set_vcpu_affinity)
629 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
630 data = data->parent_data;
637 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
638 irq_put_desc_unlock(desc, flags);
642 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
644 void __disable_irq(struct irq_desc *desc)
650 static int __disable_irq_nosync(unsigned int irq)
653 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
658 irq_put_desc_busunlock(desc, flags);
663 * disable_irq_nosync - disable an irq without waiting
664 * @irq: Interrupt to disable
666 * Disable the selected interrupt line. Disables and Enables are
668 * Unlike disable_irq(), this function does not ensure existing
669 * instances of the IRQ handler have completed before returning.
671 * This function may be called from IRQ context.
673 void disable_irq_nosync(unsigned int irq)
675 __disable_irq_nosync(irq);
677 EXPORT_SYMBOL(disable_irq_nosync);
680 * disable_irq - disable an irq and wait for completion
681 * @irq: Interrupt to disable
683 * Disable the selected interrupt line. Enables and Disables are
685 * This function waits for any pending IRQ handlers for this interrupt
686 * to complete before returning. If you use this function while
687 * holding a resource the IRQ handler may need you will deadlock.
689 * This function may be called - with care - from IRQ context.
691 void disable_irq(unsigned int irq)
693 if (!__disable_irq_nosync(irq))
694 synchronize_irq(irq);
696 EXPORT_SYMBOL(disable_irq);
699 * disable_hardirq - disables an irq and waits for hardirq completion
700 * @irq: Interrupt to disable
702 * Disable the selected interrupt line. Enables and Disables are
704 * This function waits for any pending hard IRQ handlers for this
705 * interrupt to complete before returning. If you use this function while
706 * holding a resource the hard IRQ handler may need you will deadlock.
708 * When used to optimistically disable an interrupt from atomic context
709 * the return value must be checked.
711 * Returns: false if a threaded handler is active.
713 * This function may be called - with care - from IRQ context.
715 bool disable_hardirq(unsigned int irq)
717 if (!__disable_irq_nosync(irq))
718 return synchronize_hardirq(irq);
722 EXPORT_SYMBOL_GPL(disable_hardirq);
725 * disable_nmi_nosync - disable an nmi without waiting
726 * @irq: Interrupt to disable
728 * Disable the selected interrupt line. Disables and enables are
730 * The interrupt to disable must have been requested through request_nmi.
731 * Unlike disable_nmi(), this function does not ensure existing
732 * instances of the IRQ handler have completed before returning.
734 void disable_nmi_nosync(unsigned int irq)
736 disable_irq_nosync(irq);
739 void __enable_irq(struct irq_desc *desc)
741 switch (desc->depth) {
744 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
745 irq_desc_get_irq(desc));
748 if (desc->istate & IRQS_SUSPENDED)
750 /* Prevent probing on this irq: */
751 irq_settings_set_noprobe(desc);
753 * Call irq_startup() not irq_enable() here because the
754 * interrupt might be marked NOAUTOEN. So irq_startup()
755 * needs to be invoked when it gets enabled the first
756 * time. If it was already started up, then irq_startup()
757 * will invoke irq_enable() under the hood.
759 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
768 * enable_irq - enable handling of an irq
769 * @irq: Interrupt to enable
771 * Undoes the effect of one call to disable_irq(). If this
772 * matches the last disable, processing of interrupts on this
773 * IRQ line is re-enabled.
775 * This function may be called from IRQ context only when
776 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
778 void enable_irq(unsigned int irq)
781 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
785 if (WARN(!desc->irq_data.chip,
786 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
791 irq_put_desc_busunlock(desc, flags);
793 EXPORT_SYMBOL(enable_irq);
796 * enable_nmi - enable handling of an nmi
797 * @irq: Interrupt to enable
799 * The interrupt to enable must have been requested through request_nmi.
800 * Undoes the effect of one call to disable_nmi(). If this
801 * matches the last disable, processing of interrupts on this
802 * IRQ line is re-enabled.
804 void enable_nmi(unsigned int irq)
809 static int set_irq_wake_real(unsigned int irq, unsigned int on)
811 struct irq_desc *desc = irq_to_desc(irq);
814 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
817 if (desc->irq_data.chip->irq_set_wake)
818 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
824 * irq_set_irq_wake - control irq power management wakeup
825 * @irq: interrupt to control
826 * @on: enable/disable power management wakeup
828 * Enable/disable power management wakeup mode, which is
829 * disabled by default. Enables and disables must match,
830 * just as they match for non-wakeup mode support.
832 * Wakeup mode lets this IRQ wake the system from sleep
833 * states like "suspend to RAM".
835 * Note: irq enable/disable state is completely orthogonal
836 * to the enable/disable state of irq wake. An irq can be
837 * disabled with disable_irq() and still wake the system as
838 * long as the irq has wake enabled. If this does not hold,
839 * then the underlying irq chip and the related driver need
840 * to be investigated.
842 int irq_set_irq_wake(unsigned int irq, unsigned int on)
845 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
851 /* Don't use NMIs as wake up interrupts please */
852 if (desc->istate & IRQS_NMI) {
857 /* wakeup-capable irqs can be shared between drivers that
858 * don't need to have the same sleep mode behaviors.
861 if (desc->wake_depth++ == 0) {
862 ret = set_irq_wake_real(irq, on);
864 desc->wake_depth = 0;
866 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
869 if (desc->wake_depth == 0) {
870 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
871 } else if (--desc->wake_depth == 0) {
872 ret = set_irq_wake_real(irq, on);
874 desc->wake_depth = 1;
876 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
881 irq_put_desc_busunlock(desc, flags);
884 EXPORT_SYMBOL(irq_set_irq_wake);
887 * Internal function that tells the architecture code whether a
888 * particular irq has been exclusively allocated or is available
891 int can_request_irq(unsigned int irq, unsigned long irqflags)
894 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
900 if (irq_settings_can_request(desc)) {
902 irqflags & desc->action->flags & IRQF_SHARED)
905 irq_put_desc_unlock(desc, flags);
909 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
911 struct irq_chip *chip = desc->irq_data.chip;
914 if (!chip || !chip->irq_set_type) {
916 * IRQF_TRIGGER_* but the PIC does not support multiple
919 pr_debug("No set_type function for IRQ %d (%s)\n",
920 irq_desc_get_irq(desc),
921 chip ? (chip->name ? : "unknown") : "unknown");
925 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
926 if (!irqd_irq_masked(&desc->irq_data))
928 if (!irqd_irq_disabled(&desc->irq_data))
932 /* Mask all flags except trigger mode */
933 flags &= IRQ_TYPE_SENSE_MASK;
934 ret = chip->irq_set_type(&desc->irq_data, flags);
937 case IRQ_SET_MASK_OK:
938 case IRQ_SET_MASK_OK_DONE:
939 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
940 irqd_set(&desc->irq_data, flags);
943 case IRQ_SET_MASK_OK_NOCOPY:
944 flags = irqd_get_trigger_type(&desc->irq_data);
945 irq_settings_set_trigger_mask(desc, flags);
946 irqd_clear(&desc->irq_data, IRQD_LEVEL);
947 irq_settings_clr_level(desc);
948 if (flags & IRQ_TYPE_LEVEL_MASK) {
949 irq_settings_set_level(desc);
950 irqd_set(&desc->irq_data, IRQD_LEVEL);
956 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
957 flags, irq_desc_get_irq(desc), chip->irq_set_type);
964 #ifdef CONFIG_HARDIRQS_SW_RESEND
965 int irq_set_parent(int irq, int parent_irq)
968 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
973 desc->parent_irq = parent_irq;
975 irq_put_desc_unlock(desc, flags);
978 EXPORT_SYMBOL_GPL(irq_set_parent);
982 * Default primary interrupt handler for threaded interrupts. Is
983 * assigned as primary handler when request_threaded_irq is called
984 * with handler == NULL. Useful for oneshot interrupts.
986 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
988 return IRQ_WAKE_THREAD;
992 * Primary handler for nested threaded interrupts. Should never be
995 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
997 WARN(1, "Primary handler called for nested irq %d\n", irq);
1001 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1003 WARN(1, "Secondary action handler called for irq %d\n", irq);
1007 static int irq_wait_for_interrupt(struct irqaction *action)
1010 set_current_state(TASK_INTERRUPTIBLE);
1012 if (kthread_should_stop()) {
1013 /* may need to run one last time */
1014 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1015 &action->thread_flags)) {
1016 __set_current_state(TASK_RUNNING);
1019 __set_current_state(TASK_RUNNING);
1023 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1024 &action->thread_flags)) {
1025 __set_current_state(TASK_RUNNING);
1033 * Oneshot interrupts keep the irq line masked until the threaded
1034 * handler finished. unmask if the interrupt has not been disabled and
1037 static void irq_finalize_oneshot(struct irq_desc *desc,
1038 struct irqaction *action)
1040 if (!(desc->istate & IRQS_ONESHOT) ||
1041 action->handler == irq_forced_secondary_handler)
1044 chip_bus_lock(desc);
1045 raw_spin_lock_irq(&desc->lock);
1048 * Implausible though it may be we need to protect us against
1049 * the following scenario:
1051 * The thread is faster done than the hard interrupt handler
1052 * on the other CPU. If we unmask the irq line then the
1053 * interrupt can come in again and masks the line, leaves due
1054 * to IRQS_INPROGRESS and the irq line is masked forever.
1056 * This also serializes the state of shared oneshot handlers
1057 * versus "desc->threads_oneshot |= action->thread_mask;" in
1058 * irq_wake_thread(). See the comment there which explains the
1061 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1062 raw_spin_unlock_irq(&desc->lock);
1063 chip_bus_sync_unlock(desc);
1069 * Now check again, whether the thread should run. Otherwise
1070 * we would clear the threads_oneshot bit of this thread which
1073 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1076 desc->threads_oneshot &= ~action->thread_mask;
1078 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1079 irqd_irq_masked(&desc->irq_data))
1080 unmask_threaded_irq(desc);
1083 raw_spin_unlock_irq(&desc->lock);
1084 chip_bus_sync_unlock(desc);
1089 * Check whether we need to change the affinity of the interrupt thread.
1092 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1097 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1101 * In case we are out of memory we set IRQTF_AFFINITY again and
1102 * try again next time
1104 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1105 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1109 raw_spin_lock_irq(&desc->lock);
1111 * This code is triggered unconditionally. Check the affinity
1112 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1114 if (cpumask_available(desc->irq_common_data.affinity)) {
1115 const struct cpumask *m;
1117 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1118 cpumask_copy(mask, m);
1122 raw_spin_unlock_irq(&desc->lock);
1125 set_cpus_allowed_ptr(current, mask);
1126 free_cpumask_var(mask);
1130 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1134 * Interrupts which are not explicitly requested as threaded
1135 * interrupts rely on the implicit bh/preempt disable of the hard irq
1136 * context. So we need to disable bh here to avoid deadlocks and other
1140 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1145 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1146 local_irq_disable();
1147 ret = action->thread_fn(action->irq, action->dev_id);
1148 if (ret == IRQ_HANDLED)
1149 atomic_inc(&desc->threads_handled);
1151 irq_finalize_oneshot(desc, action);
1152 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1159 * Interrupts explicitly requested as threaded interrupts want to be
1160 * preemptible - many of them need to sleep and wait for slow busses to
1163 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1164 struct irqaction *action)
1168 ret = action->thread_fn(action->irq, action->dev_id);
1169 if (ret == IRQ_HANDLED)
1170 atomic_inc(&desc->threads_handled);
1172 irq_finalize_oneshot(desc, action);
1176 static void wake_threads_waitq(struct irq_desc *desc)
1178 if (atomic_dec_and_test(&desc->threads_active))
1179 wake_up(&desc->wait_for_threads);
1182 static void irq_thread_dtor(struct callback_head *unused)
1184 struct task_struct *tsk = current;
1185 struct irq_desc *desc;
1186 struct irqaction *action;
1188 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1191 action = kthread_data(tsk);
1193 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1194 tsk->comm, tsk->pid, action->irq);
1197 desc = irq_to_desc(action->irq);
1199 * If IRQTF_RUNTHREAD is set, we need to decrement
1200 * desc->threads_active and wake possible waiters.
1202 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1203 wake_threads_waitq(desc);
1205 /* Prevent a stale desc->threads_oneshot */
1206 irq_finalize_oneshot(desc, action);
1209 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1211 struct irqaction *secondary = action->secondary;
1213 if (WARN_ON_ONCE(!secondary))
1216 raw_spin_lock_irq(&desc->lock);
1217 __irq_wake_thread(desc, secondary);
1218 raw_spin_unlock_irq(&desc->lock);
1222 * Interrupt handler thread
1224 static int irq_thread(void *data)
1226 struct callback_head on_exit_work;
1227 struct irqaction *action = data;
1228 struct irq_desc *desc = irq_to_desc(action->irq);
1229 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1230 struct irqaction *action);
1232 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1233 &action->thread_flags))
1234 handler_fn = irq_forced_thread_fn;
1236 handler_fn = irq_thread_fn;
1238 init_task_work(&on_exit_work, irq_thread_dtor);
1239 task_work_add(current, &on_exit_work, TWA_NONE);
1241 irq_thread_check_affinity(desc, action);
1243 while (!irq_wait_for_interrupt(action)) {
1244 irqreturn_t action_ret;
1246 irq_thread_check_affinity(desc, action);
1248 action_ret = handler_fn(desc, action);
1249 if (action_ret == IRQ_WAKE_THREAD)
1250 irq_wake_secondary(desc, action);
1252 wake_threads_waitq(desc);
1256 * This is the regular exit path. __free_irq() is stopping the
1257 * thread via kthread_stop() after calling
1258 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1259 * oneshot mask bit can be set.
1261 task_work_cancel(current, irq_thread_dtor);
1266 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1267 * @irq: Interrupt line
1268 * @dev_id: Device identity for which the thread should be woken
1271 void irq_wake_thread(unsigned int irq, void *dev_id)
1273 struct irq_desc *desc = irq_to_desc(irq);
1274 struct irqaction *action;
1275 unsigned long flags;
1277 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1280 raw_spin_lock_irqsave(&desc->lock, flags);
1281 for_each_action_of_desc(desc, action) {
1282 if (action->dev_id == dev_id) {
1284 __irq_wake_thread(desc, action);
1288 raw_spin_unlock_irqrestore(&desc->lock, flags);
1290 EXPORT_SYMBOL_GPL(irq_wake_thread);
1292 static int irq_setup_forced_threading(struct irqaction *new)
1294 if (!force_irqthreads)
1296 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1300 * No further action required for interrupts which are requested as
1301 * threaded interrupts already
1303 if (new->handler == irq_default_primary_handler)
1306 new->flags |= IRQF_ONESHOT;
1309 * Handle the case where we have a real primary handler and a
1310 * thread handler. We force thread them as well by creating a
1313 if (new->handler && new->thread_fn) {
1314 /* Allocate the secondary action */
1315 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1316 if (!new->secondary)
1318 new->secondary->handler = irq_forced_secondary_handler;
1319 new->secondary->thread_fn = new->thread_fn;
1320 new->secondary->dev_id = new->dev_id;
1321 new->secondary->irq = new->irq;
1322 new->secondary->name = new->name;
1324 /* Deal with the primary handler */
1325 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1326 new->thread_fn = new->handler;
1327 new->handler = irq_default_primary_handler;
1331 static int irq_request_resources(struct irq_desc *desc)
1333 struct irq_data *d = &desc->irq_data;
1334 struct irq_chip *c = d->chip;
1336 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1339 static void irq_release_resources(struct irq_desc *desc)
1341 struct irq_data *d = &desc->irq_data;
1342 struct irq_chip *c = d->chip;
1344 if (c->irq_release_resources)
1345 c->irq_release_resources(d);
1348 static bool irq_supports_nmi(struct irq_desc *desc)
1350 struct irq_data *d = irq_desc_get_irq_data(desc);
1352 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1353 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1357 /* Don't support NMIs for chips behind a slow bus */
1358 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1361 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1364 static int irq_nmi_setup(struct irq_desc *desc)
1366 struct irq_data *d = irq_desc_get_irq_data(desc);
1367 struct irq_chip *c = d->chip;
1369 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1372 static void irq_nmi_teardown(struct irq_desc *desc)
1374 struct irq_data *d = irq_desc_get_irq_data(desc);
1375 struct irq_chip *c = d->chip;
1377 if (c->irq_nmi_teardown)
1378 c->irq_nmi_teardown(d);
1382 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1384 struct task_struct *t;
1387 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1390 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1400 * We keep the reference to the task struct even if
1401 * the thread dies to avoid that the interrupt code
1402 * references an already freed task_struct.
1404 new->thread = get_task_struct(t);
1406 * Tell the thread to set its affinity. This is
1407 * important for shared interrupt handlers as we do
1408 * not invoke setup_affinity() for the secondary
1409 * handlers as everything is already set up. Even for
1410 * interrupts marked with IRQF_NO_BALANCE this is
1411 * correct as we want the thread to move to the cpu(s)
1412 * on which the requesting code placed the interrupt.
1414 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1419 * Internal function to register an irqaction - typically used to
1420 * allocate special interrupts that are part of the architecture.
1424 * desc->request_mutex Provides serialization against a concurrent free_irq()
1425 * chip_bus_lock Provides serialization for slow bus operations
1426 * desc->lock Provides serialization against hard interrupts
1428 * chip_bus_lock and desc->lock are sufficient for all other management and
1429 * interrupt related functions. desc->request_mutex solely serializes
1430 * request/free_irq().
1433 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1435 struct irqaction *old, **old_ptr;
1436 unsigned long flags, thread_mask = 0;
1437 int ret, nested, shared = 0;
1442 if (desc->irq_data.chip == &no_irq_chip)
1444 if (!try_module_get(desc->owner))
1450 * If the trigger type is not specified by the caller,
1451 * then use the default for this interrupt.
1453 if (!(new->flags & IRQF_TRIGGER_MASK))
1454 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1457 * Check whether the interrupt nests into another interrupt
1460 nested = irq_settings_is_nested_thread(desc);
1462 if (!new->thread_fn) {
1467 * Replace the primary handler which was provided from
1468 * the driver for non nested interrupt handling by the
1469 * dummy function which warns when called.
1471 new->handler = irq_nested_primary_handler;
1473 if (irq_settings_can_thread(desc)) {
1474 ret = irq_setup_forced_threading(new);
1481 * Create a handler thread when a thread function is supplied
1482 * and the interrupt does not nest into another interrupt
1485 if (new->thread_fn && !nested) {
1486 ret = setup_irq_thread(new, irq, false);
1489 if (new->secondary) {
1490 ret = setup_irq_thread(new->secondary, irq, true);
1497 * Drivers are often written to work w/o knowledge about the
1498 * underlying irq chip implementation, so a request for a
1499 * threaded irq without a primary hard irq context handler
1500 * requires the ONESHOT flag to be set. Some irq chips like
1501 * MSI based interrupts are per se one shot safe. Check the
1502 * chip flags, so we can avoid the unmask dance at the end of
1503 * the threaded handler for those.
1505 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1506 new->flags &= ~IRQF_ONESHOT;
1509 * Protects against a concurrent __free_irq() call which might wait
1510 * for synchronize_hardirq() to complete without holding the optional
1511 * chip bus lock and desc->lock. Also protects against handing out
1512 * a recycled oneshot thread_mask bit while it's still in use by
1513 * its previous owner.
1515 mutex_lock(&desc->request_mutex);
1518 * Acquire bus lock as the irq_request_resources() callback below
1519 * might rely on the serialization or the magic power management
1520 * functions which are abusing the irq_bus_lock() callback,
1522 chip_bus_lock(desc);
1524 /* First installed action requests resources. */
1525 if (!desc->action) {
1526 ret = irq_request_resources(desc);
1528 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1529 new->name, irq, desc->irq_data.chip->name);
1530 goto out_bus_unlock;
1535 * The following block of code has to be executed atomically
1536 * protected against a concurrent interrupt and any of the other
1537 * management calls which are not serialized via
1538 * desc->request_mutex or the optional bus lock.
1540 raw_spin_lock_irqsave(&desc->lock, flags);
1541 old_ptr = &desc->action;
1545 * Can't share interrupts unless both agree to and are
1546 * the same type (level, edge, polarity). So both flag
1547 * fields must have IRQF_SHARED set and the bits which
1548 * set the trigger type must match. Also all must
1550 * Interrupt lines used for NMIs cannot be shared.
1552 unsigned int oldtype;
1554 if (desc->istate & IRQS_NMI) {
1555 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1556 new->name, irq, desc->irq_data.chip->name);
1562 * If nobody did set the configuration before, inherit
1563 * the one provided by the requester.
1565 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1566 oldtype = irqd_get_trigger_type(&desc->irq_data);
1568 oldtype = new->flags & IRQF_TRIGGER_MASK;
1569 irqd_set_trigger_type(&desc->irq_data, oldtype);
1572 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1573 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1574 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1577 /* All handlers must agree on per-cpuness */
1578 if ((old->flags & IRQF_PERCPU) !=
1579 (new->flags & IRQF_PERCPU))
1582 /* add new interrupt at end of irq queue */
1585 * Or all existing action->thread_mask bits,
1586 * so we can find the next zero bit for this
1589 thread_mask |= old->thread_mask;
1590 old_ptr = &old->next;
1597 * Setup the thread mask for this irqaction for ONESHOT. For
1598 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1599 * conditional in irq_wake_thread().
1601 if (new->flags & IRQF_ONESHOT) {
1603 * Unlikely to have 32 resp 64 irqs sharing one line,
1606 if (thread_mask == ~0UL) {
1611 * The thread_mask for the action is or'ed to
1612 * desc->thread_active to indicate that the
1613 * IRQF_ONESHOT thread handler has been woken, but not
1614 * yet finished. The bit is cleared when a thread
1615 * completes. When all threads of a shared interrupt
1616 * line have completed desc->threads_active becomes
1617 * zero and the interrupt line is unmasked. See
1618 * handle.c:irq_wake_thread() for further information.
1620 * If no thread is woken by primary (hard irq context)
1621 * interrupt handlers, then desc->threads_active is
1622 * also checked for zero to unmask the irq line in the
1623 * affected hard irq flow handlers
1624 * (handle_[fasteoi|level]_irq).
1626 * The new action gets the first zero bit of
1627 * thread_mask assigned. See the loop above which or's
1628 * all existing action->thread_mask bits.
1630 new->thread_mask = 1UL << ffz(thread_mask);
1632 } else if (new->handler == irq_default_primary_handler &&
1633 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1635 * The interrupt was requested with handler = NULL, so
1636 * we use the default primary handler for it. But it
1637 * does not have the oneshot flag set. In combination
1638 * with level interrupts this is deadly, because the
1639 * default primary handler just wakes the thread, then
1640 * the irq lines is reenabled, but the device still
1641 * has the level irq asserted. Rinse and repeat....
1643 * While this works for edge type interrupts, we play
1644 * it safe and reject unconditionally because we can't
1645 * say for sure which type this interrupt really
1646 * has. The type flags are unreliable as the
1647 * underlying chip implementation can override them.
1649 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1656 init_waitqueue_head(&desc->wait_for_threads);
1658 /* Setup the type (level, edge polarity) if configured: */
1659 if (new->flags & IRQF_TRIGGER_MASK) {
1660 ret = __irq_set_trigger(desc,
1661 new->flags & IRQF_TRIGGER_MASK);
1668 * Activate the interrupt. That activation must happen
1669 * independently of IRQ_NOAUTOEN. request_irq() can fail
1670 * and the callers are supposed to handle
1671 * that. enable_irq() of an interrupt requested with
1672 * IRQ_NOAUTOEN is not supposed to fail. The activation
1673 * keeps it in shutdown mode, it merily associates
1674 * resources if necessary and if that's not possible it
1675 * fails. Interrupts which are in managed shutdown mode
1676 * will simply ignore that activation request.
1678 ret = irq_activate(desc);
1682 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1683 IRQS_ONESHOT | IRQS_WAITING);
1684 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1686 if (new->flags & IRQF_PERCPU) {
1687 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1688 irq_settings_set_per_cpu(desc);
1691 if (new->flags & IRQF_ONESHOT)
1692 desc->istate |= IRQS_ONESHOT;
1694 /* Exclude IRQ from balancing if requested */
1695 if (new->flags & IRQF_NOBALANCING) {
1696 irq_settings_set_no_balancing(desc);
1697 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1700 if (!(new->flags & IRQF_NO_AUTOEN) &&
1701 irq_settings_can_autoenable(desc)) {
1702 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1705 * Shared interrupts do not go well with disabling
1706 * auto enable. The sharing interrupt might request
1707 * it while it's still disabled and then wait for
1708 * interrupts forever.
1710 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1711 /* Undo nested disables: */
1715 } else if (new->flags & IRQF_TRIGGER_MASK) {
1716 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1717 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1720 /* hope the handler works with current trigger mode */
1721 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1727 irq_pm_install_action(desc, new);
1729 /* Reset broken irq detection when installing new handler */
1730 desc->irq_count = 0;
1731 desc->irqs_unhandled = 0;
1734 * Check whether we disabled the irq via the spurious handler
1735 * before. Reenable it and give it another chance.
1737 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1738 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1742 raw_spin_unlock_irqrestore(&desc->lock, flags);
1743 chip_bus_sync_unlock(desc);
1744 mutex_unlock(&desc->request_mutex);
1746 irq_setup_timings(desc, new);
1749 * Strictly no need to wake it up, but hung_task complains
1750 * when no hard interrupt wakes the thread up.
1753 wake_up_process(new->thread);
1755 wake_up_process(new->secondary->thread);
1757 register_irq_proc(irq, desc);
1759 register_handler_proc(irq, new);
1763 if (!(new->flags & IRQF_PROBE_SHARED)) {
1764 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1765 irq, new->flags, new->name, old->flags, old->name);
1766 #ifdef CONFIG_DEBUG_SHIRQ
1773 raw_spin_unlock_irqrestore(&desc->lock, flags);
1776 irq_release_resources(desc);
1778 chip_bus_sync_unlock(desc);
1779 mutex_unlock(&desc->request_mutex);
1783 struct task_struct *t = new->thread;
1789 if (new->secondary && new->secondary->thread) {
1790 struct task_struct *t = new->secondary->thread;
1792 new->secondary->thread = NULL;
1797 module_put(desc->owner);
1802 * Internal function to unregister an irqaction - used to free
1803 * regular and special interrupts that are part of the architecture.
1805 static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1807 unsigned irq = desc->irq_data.irq;
1808 struct irqaction *action, **action_ptr;
1809 unsigned long flags;
1811 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1813 mutex_lock(&desc->request_mutex);
1814 chip_bus_lock(desc);
1815 raw_spin_lock_irqsave(&desc->lock, flags);
1818 * There can be multiple actions per IRQ descriptor, find the right
1819 * one based on the dev_id:
1821 action_ptr = &desc->action;
1823 action = *action_ptr;
1826 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1827 raw_spin_unlock_irqrestore(&desc->lock, flags);
1828 chip_bus_sync_unlock(desc);
1829 mutex_unlock(&desc->request_mutex);
1833 if (action->dev_id == dev_id)
1835 action_ptr = &action->next;
1838 /* Found it - now remove it from the list of entries: */
1839 *action_ptr = action->next;
1841 irq_pm_remove_action(desc, action);
1843 /* If this was the last handler, shut down the IRQ line: */
1844 if (!desc->action) {
1845 irq_settings_clr_disable_unlazy(desc);
1846 /* Only shutdown. Deactivate after synchronize_hardirq() */
1851 /* make sure affinity_hint is cleaned up */
1852 if (WARN_ON_ONCE(desc->affinity_hint))
1853 desc->affinity_hint = NULL;
1856 raw_spin_unlock_irqrestore(&desc->lock, flags);
1858 * Drop bus_lock here so the changes which were done in the chip
1859 * callbacks above are synced out to the irq chips which hang
1860 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1862 * Aside of that the bus_lock can also be taken from the threaded
1863 * handler in irq_finalize_oneshot() which results in a deadlock
1864 * because kthread_stop() would wait forever for the thread to
1865 * complete, which is blocked on the bus lock.
1867 * The still held desc->request_mutex() protects against a
1868 * concurrent request_irq() of this irq so the release of resources
1869 * and timing data is properly serialized.
1871 chip_bus_sync_unlock(desc);
1873 unregister_handler_proc(irq, action);
1876 * Make sure it's not being used on another CPU and if the chip
1877 * supports it also make sure that there is no (not yet serviced)
1878 * interrupt in flight at the hardware level.
1880 __synchronize_hardirq(desc, true);
1882 #ifdef CONFIG_DEBUG_SHIRQ
1884 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1885 * event to happen even now it's being freed, so let's make sure that
1886 * is so by doing an extra call to the handler ....
1888 * ( We do this after actually deregistering it, to make sure that a
1889 * 'real' IRQ doesn't run in parallel with our fake. )
1891 if (action->flags & IRQF_SHARED) {
1892 local_irq_save(flags);
1893 action->handler(irq, dev_id);
1894 local_irq_restore(flags);
1899 * The action has already been removed above, but the thread writes
1900 * its oneshot mask bit when it completes. Though request_mutex is
1901 * held across this which prevents __setup_irq() from handing out
1902 * the same bit to a newly requested action.
1904 if (action->thread) {
1905 kthread_stop(action->thread);
1906 put_task_struct(action->thread);
1907 if (action->secondary && action->secondary->thread) {
1908 kthread_stop(action->secondary->thread);
1909 put_task_struct(action->secondary->thread);
1913 /* Last action releases resources */
1914 if (!desc->action) {
1916 * Reacquire bus lock as irq_release_resources() might
1917 * require it to deallocate resources over the slow bus.
1919 chip_bus_lock(desc);
1921 * There is no interrupt on the fly anymore. Deactivate it
1924 raw_spin_lock_irqsave(&desc->lock, flags);
1925 irq_domain_deactivate_irq(&desc->irq_data);
1926 raw_spin_unlock_irqrestore(&desc->lock, flags);
1928 irq_release_resources(desc);
1929 chip_bus_sync_unlock(desc);
1930 irq_remove_timings(desc);
1933 mutex_unlock(&desc->request_mutex);
1935 irq_chip_pm_put(&desc->irq_data);
1936 module_put(desc->owner);
1937 kfree(action->secondary);
1942 * free_irq - free an interrupt allocated with request_irq
1943 * @irq: Interrupt line to free
1944 * @dev_id: Device identity to free
1946 * Remove an interrupt handler. The handler is removed and if the
1947 * interrupt line is no longer in use by any driver it is disabled.
1948 * On a shared IRQ the caller must ensure the interrupt is disabled
1949 * on the card it drives before calling this function. The function
1950 * does not return until any executing interrupts for this IRQ
1953 * This function must not be called from interrupt context.
1955 * Returns the devname argument passed to request_irq.
1957 const void *free_irq(unsigned int irq, void *dev_id)
1959 struct irq_desc *desc = irq_to_desc(irq);
1960 struct irqaction *action;
1961 const char *devname;
1963 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1967 if (WARN_ON(desc->affinity_notify))
1968 desc->affinity_notify = NULL;
1971 action = __free_irq(desc, dev_id);
1976 devname = action->name;
1980 EXPORT_SYMBOL(free_irq);
1982 /* This function must be called with desc->lock held */
1983 static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1985 const char *devname = NULL;
1987 desc->istate &= ~IRQS_NMI;
1989 if (!WARN_ON(desc->action == NULL)) {
1990 irq_pm_remove_action(desc, desc->action);
1991 devname = desc->action->name;
1992 unregister_handler_proc(irq, desc->action);
1994 kfree(desc->action);
1995 desc->action = NULL;
1998 irq_settings_clr_disable_unlazy(desc);
1999 irq_shutdown_and_deactivate(desc);
2001 irq_release_resources(desc);
2003 irq_chip_pm_put(&desc->irq_data);
2004 module_put(desc->owner);
2009 const void *free_nmi(unsigned int irq, void *dev_id)
2011 struct irq_desc *desc = irq_to_desc(irq);
2012 unsigned long flags;
2013 const void *devname;
2015 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2018 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2021 /* NMI still enabled */
2022 if (WARN_ON(desc->depth == 0))
2023 disable_nmi_nosync(irq);
2025 raw_spin_lock_irqsave(&desc->lock, flags);
2027 irq_nmi_teardown(desc);
2028 devname = __cleanup_nmi(irq, desc);
2030 raw_spin_unlock_irqrestore(&desc->lock, flags);
2036 * request_threaded_irq - allocate an interrupt line
2037 * @irq: Interrupt line to allocate
2038 * @handler: Function to be called when the IRQ occurs.
2039 * Primary handler for threaded interrupts
2040 * If NULL and thread_fn != NULL the default
2041 * primary handler is installed
2042 * @thread_fn: Function called from the irq handler thread
2043 * If NULL, no irq thread is created
2044 * @irqflags: Interrupt type flags
2045 * @devname: An ascii name for the claiming device
2046 * @dev_id: A cookie passed back to the handler function
2048 * This call allocates interrupt resources and enables the
2049 * interrupt line and IRQ handling. From the point this
2050 * call is made your handler function may be invoked. Since
2051 * your handler function must clear any interrupt the board
2052 * raises, you must take care both to initialise your hardware
2053 * and to set up the interrupt handler in the right order.
2055 * If you want to set up a threaded irq handler for your device
2056 * then you need to supply @handler and @thread_fn. @handler is
2057 * still called in hard interrupt context and has to check
2058 * whether the interrupt originates from the device. If yes it
2059 * needs to disable the interrupt on the device and return
2060 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2061 * @thread_fn. This split handler design is necessary to support
2062 * shared interrupts.
2064 * Dev_id must be globally unique. Normally the address of the
2065 * device data structure is used as the cookie. Since the handler
2066 * receives this value it makes sense to use it.
2068 * If your interrupt is shared you must pass a non NULL dev_id
2069 * as this is required when freeing the interrupt.
2073 * IRQF_SHARED Interrupt is shared
2074 * IRQF_TRIGGER_* Specify active edge(s) or level
2077 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2078 irq_handler_t thread_fn, unsigned long irqflags,
2079 const char *devname, void *dev_id)
2081 struct irqaction *action;
2082 struct irq_desc *desc;
2085 if (irq == IRQ_NOTCONNECTED)
2089 * Sanity-check: shared interrupts must pass in a real dev-ID,
2090 * otherwise we'll have trouble later trying to figure out
2091 * which interrupt is which (messes up the interrupt freeing
2094 * Also shared interrupts do not go well with disabling auto enable.
2095 * The sharing interrupt might request it while it's still disabled
2096 * and then wait for interrupts forever.
2098 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2099 * it cannot be set along with IRQF_NO_SUSPEND.
2101 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2102 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2103 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2104 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2107 desc = irq_to_desc(irq);
2111 if (!irq_settings_can_request(desc) ||
2112 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2118 handler = irq_default_primary_handler;
2121 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2125 action->handler = handler;
2126 action->thread_fn = thread_fn;
2127 action->flags = irqflags;
2128 action->name = devname;
2129 action->dev_id = dev_id;
2131 retval = irq_chip_pm_get(&desc->irq_data);
2137 retval = __setup_irq(irq, desc, action);
2140 irq_chip_pm_put(&desc->irq_data);
2141 kfree(action->secondary);
2145 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2146 if (!retval && (irqflags & IRQF_SHARED)) {
2148 * It's a shared IRQ -- the driver ought to be prepared for it
2149 * to happen immediately, so let's make sure....
2150 * We disable the irq to make sure that a 'real' IRQ doesn't
2151 * run in parallel with our fake.
2153 unsigned long flags;
2156 local_irq_save(flags);
2158 handler(irq, dev_id);
2160 local_irq_restore(flags);
2166 EXPORT_SYMBOL(request_threaded_irq);
2169 * request_any_context_irq - allocate an interrupt line
2170 * @irq: Interrupt line to allocate
2171 * @handler: Function to be called when the IRQ occurs.
2172 * Threaded handler for threaded interrupts.
2173 * @flags: Interrupt type flags
2174 * @name: An ascii name for the claiming device
2175 * @dev_id: A cookie passed back to the handler function
2177 * This call allocates interrupt resources and enables the
2178 * interrupt line and IRQ handling. It selects either a
2179 * hardirq or threaded handling method depending on the
2182 * On failure, it returns a negative value. On success,
2183 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2185 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2186 unsigned long flags, const char *name, void *dev_id)
2188 struct irq_desc *desc;
2191 if (irq == IRQ_NOTCONNECTED)
2194 desc = irq_to_desc(irq);
2198 if (irq_settings_is_nested_thread(desc)) {
2199 ret = request_threaded_irq(irq, NULL, handler,
2200 flags, name, dev_id);
2201 return !ret ? IRQC_IS_NESTED : ret;
2204 ret = request_irq(irq, handler, flags, name, dev_id);
2205 return !ret ? IRQC_IS_HARDIRQ : ret;
2207 EXPORT_SYMBOL_GPL(request_any_context_irq);
2210 * request_nmi - allocate an interrupt line for NMI delivery
2211 * @irq: Interrupt line to allocate
2212 * @handler: Function to be called when the IRQ occurs.
2213 * Threaded handler for threaded interrupts.
2214 * @irqflags: Interrupt type flags
2215 * @name: An ascii name for the claiming device
2216 * @dev_id: A cookie passed back to the handler function
2218 * This call allocates interrupt resources and enables the
2219 * interrupt line and IRQ handling. It sets up the IRQ line
2220 * to be handled as an NMI.
2222 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2223 * cannot be threaded.
2225 * Interrupt lines requested for NMI delivering must produce per cpu
2226 * interrupts and have auto enabling setting disabled.
2228 * Dev_id must be globally unique. Normally the address of the
2229 * device data structure is used as the cookie. Since the handler
2230 * receives this value it makes sense to use it.
2232 * If the interrupt line cannot be used to deliver NMIs, function
2233 * will fail and return a negative value.
2235 int request_nmi(unsigned int irq, irq_handler_t handler,
2236 unsigned long irqflags, const char *name, void *dev_id)
2238 struct irqaction *action;
2239 struct irq_desc *desc;
2240 unsigned long flags;
2243 if (irq == IRQ_NOTCONNECTED)
2246 /* NMI cannot be shared, used for Polling */
2247 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2250 if (!(irqflags & IRQF_PERCPU))
2256 desc = irq_to_desc(irq);
2258 if (!desc || (irq_settings_can_autoenable(desc) &&
2259 !(irqflags & IRQF_NO_AUTOEN)) ||
2260 !irq_settings_can_request(desc) ||
2261 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2262 !irq_supports_nmi(desc))
2265 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2269 action->handler = handler;
2270 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2271 action->name = name;
2272 action->dev_id = dev_id;
2274 retval = irq_chip_pm_get(&desc->irq_data);
2278 retval = __setup_irq(irq, desc, action);
2282 raw_spin_lock_irqsave(&desc->lock, flags);
2284 /* Setup NMI state */
2285 desc->istate |= IRQS_NMI;
2286 retval = irq_nmi_setup(desc);
2288 __cleanup_nmi(irq, desc);
2289 raw_spin_unlock_irqrestore(&desc->lock, flags);
2293 raw_spin_unlock_irqrestore(&desc->lock, flags);
2298 irq_chip_pm_put(&desc->irq_data);
2305 void enable_percpu_irq(unsigned int irq, unsigned int type)
2307 unsigned int cpu = smp_processor_id();
2308 unsigned long flags;
2309 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2315 * If the trigger type is not specified by the caller, then
2316 * use the default for this interrupt.
2318 type &= IRQ_TYPE_SENSE_MASK;
2319 if (type == IRQ_TYPE_NONE)
2320 type = irqd_get_trigger_type(&desc->irq_data);
2322 if (type != IRQ_TYPE_NONE) {
2325 ret = __irq_set_trigger(desc, type);
2328 WARN(1, "failed to set type for IRQ%d\n", irq);
2333 irq_percpu_enable(desc, cpu);
2335 irq_put_desc_unlock(desc, flags);
2337 EXPORT_SYMBOL_GPL(enable_percpu_irq);
2339 void enable_percpu_nmi(unsigned int irq, unsigned int type)
2341 enable_percpu_irq(irq, type);
2345 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2346 * @irq: Linux irq number to check for
2348 * Must be called from a non migratable context. Returns the enable
2349 * state of a per cpu interrupt on the current cpu.
2351 bool irq_percpu_is_enabled(unsigned int irq)
2353 unsigned int cpu = smp_processor_id();
2354 struct irq_desc *desc;
2355 unsigned long flags;
2358 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2362 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2363 irq_put_desc_unlock(desc, flags);
2367 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2369 void disable_percpu_irq(unsigned int irq)
2371 unsigned int cpu = smp_processor_id();
2372 unsigned long flags;
2373 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2378 irq_percpu_disable(desc, cpu);
2379 irq_put_desc_unlock(desc, flags);
2381 EXPORT_SYMBOL_GPL(disable_percpu_irq);
2383 void disable_percpu_nmi(unsigned int irq)
2385 disable_percpu_irq(irq);
2389 * Internal function to unregister a percpu irqaction.
2391 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2393 struct irq_desc *desc = irq_to_desc(irq);
2394 struct irqaction *action;
2395 unsigned long flags;
2397 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2402 raw_spin_lock_irqsave(&desc->lock, flags);
2404 action = desc->action;
2405 if (!action || action->percpu_dev_id != dev_id) {
2406 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2410 if (!cpumask_empty(desc->percpu_enabled)) {
2411 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2412 irq, cpumask_first(desc->percpu_enabled));
2416 /* Found it - now remove it from the list of entries: */
2417 desc->action = NULL;
2419 desc->istate &= ~IRQS_NMI;
2421 raw_spin_unlock_irqrestore(&desc->lock, flags);
2423 unregister_handler_proc(irq, action);
2425 irq_chip_pm_put(&desc->irq_data);
2426 module_put(desc->owner);
2430 raw_spin_unlock_irqrestore(&desc->lock, flags);
2435 * remove_percpu_irq - free a per-cpu interrupt
2436 * @irq: Interrupt line to free
2437 * @act: irqaction for the interrupt
2439 * Used to remove interrupts statically setup by the early boot process.
2441 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2443 struct irq_desc *desc = irq_to_desc(irq);
2445 if (desc && irq_settings_is_per_cpu_devid(desc))
2446 __free_percpu_irq(irq, act->percpu_dev_id);
2450 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2451 * @irq: Interrupt line to free
2452 * @dev_id: Device identity to free
2454 * Remove a percpu interrupt handler. The handler is removed, but
2455 * the interrupt line is not disabled. This must be done on each
2456 * CPU before calling this function. The function does not return
2457 * until any executing interrupts for this IRQ have completed.
2459 * This function must not be called from interrupt context.
2461 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2463 struct irq_desc *desc = irq_to_desc(irq);
2465 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2468 chip_bus_lock(desc);
2469 kfree(__free_percpu_irq(irq, dev_id));
2470 chip_bus_sync_unlock(desc);
2472 EXPORT_SYMBOL_GPL(free_percpu_irq);
2474 void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2476 struct irq_desc *desc = irq_to_desc(irq);
2478 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2481 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2484 kfree(__free_percpu_irq(irq, dev_id));
2488 * setup_percpu_irq - setup a per-cpu interrupt
2489 * @irq: Interrupt line to setup
2490 * @act: irqaction for the interrupt
2492 * Used to statically setup per-cpu interrupts in the early boot process.
2494 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2496 struct irq_desc *desc = irq_to_desc(irq);
2499 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2502 retval = irq_chip_pm_get(&desc->irq_data);
2506 retval = __setup_irq(irq, desc, act);
2509 irq_chip_pm_put(&desc->irq_data);
2515 * __request_percpu_irq - allocate a percpu interrupt line
2516 * @irq: Interrupt line to allocate
2517 * @handler: Function to be called when the IRQ occurs.
2518 * @flags: Interrupt type flags (IRQF_TIMER only)
2519 * @devname: An ascii name for the claiming device
2520 * @dev_id: A percpu cookie passed back to the handler function
2522 * This call allocates interrupt resources and enables the
2523 * interrupt on the local CPU. If the interrupt is supposed to be
2524 * enabled on other CPUs, it has to be done on each CPU using
2525 * enable_percpu_irq().
2527 * Dev_id must be globally unique. It is a per-cpu variable, and
2528 * the handler gets called with the interrupted CPU's instance of
2531 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2532 unsigned long flags, const char *devname,
2533 void __percpu *dev_id)
2535 struct irqaction *action;
2536 struct irq_desc *desc;
2542 desc = irq_to_desc(irq);
2543 if (!desc || !irq_settings_can_request(desc) ||
2544 !irq_settings_is_per_cpu_devid(desc))
2547 if (flags && flags != IRQF_TIMER)
2550 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2554 action->handler = handler;
2555 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2556 action->name = devname;
2557 action->percpu_dev_id = dev_id;
2559 retval = irq_chip_pm_get(&desc->irq_data);
2565 retval = __setup_irq(irq, desc, action);
2568 irq_chip_pm_put(&desc->irq_data);
2574 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2577 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2578 * @irq: Interrupt line to allocate
2579 * @handler: Function to be called when the IRQ occurs.
2580 * @name: An ascii name for the claiming device
2581 * @dev_id: A percpu cookie passed back to the handler function
2583 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2584 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2585 * being enabled on the same CPU by using enable_percpu_nmi().
2587 * Dev_id must be globally unique. It is a per-cpu variable, and
2588 * the handler gets called with the interrupted CPU's instance of
2591 * Interrupt lines requested for NMI delivering should have auto enabling
2594 * If the interrupt line cannot be used to deliver NMIs, function
2595 * will fail returning a negative value.
2597 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2598 const char *name, void __percpu *dev_id)
2600 struct irqaction *action;
2601 struct irq_desc *desc;
2602 unsigned long flags;
2608 desc = irq_to_desc(irq);
2610 if (!desc || !irq_settings_can_request(desc) ||
2611 !irq_settings_is_per_cpu_devid(desc) ||
2612 irq_settings_can_autoenable(desc) ||
2613 !irq_supports_nmi(desc))
2616 /* The line cannot already be NMI */
2617 if (desc->istate & IRQS_NMI)
2620 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2624 action->handler = handler;
2625 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2627 action->name = name;
2628 action->percpu_dev_id = dev_id;
2630 retval = irq_chip_pm_get(&desc->irq_data);
2634 retval = __setup_irq(irq, desc, action);
2638 raw_spin_lock_irqsave(&desc->lock, flags);
2639 desc->istate |= IRQS_NMI;
2640 raw_spin_unlock_irqrestore(&desc->lock, flags);
2645 irq_chip_pm_put(&desc->irq_data);
2653 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2654 * @irq: Interrupt line to prepare for NMI delivery
2656 * This call prepares an interrupt line to deliver NMI on the current CPU,
2657 * before that interrupt line gets enabled with enable_percpu_nmi().
2659 * As a CPU local operation, this should be called from non-preemptible
2662 * If the interrupt line cannot be used to deliver NMIs, function
2663 * will fail returning a negative value.
2665 int prepare_percpu_nmi(unsigned int irq)
2667 unsigned long flags;
2668 struct irq_desc *desc;
2671 WARN_ON(preemptible());
2673 desc = irq_get_desc_lock(irq, &flags,
2674 IRQ_GET_DESC_CHECK_PERCPU);
2678 if (WARN(!(desc->istate & IRQS_NMI),
2679 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2685 ret = irq_nmi_setup(desc);
2687 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2692 irq_put_desc_unlock(desc, flags);
2697 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2698 * @irq: Interrupt line from which CPU local NMI configuration should be
2701 * This call undoes the setup done by prepare_percpu_nmi().
2703 * IRQ line should not be enabled for the current CPU.
2705 * As a CPU local operation, this should be called from non-preemptible
2708 void teardown_percpu_nmi(unsigned int irq)
2710 unsigned long flags;
2711 struct irq_desc *desc;
2713 WARN_ON(preemptible());
2715 desc = irq_get_desc_lock(irq, &flags,
2716 IRQ_GET_DESC_CHECK_PERCPU);
2720 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2723 irq_nmi_teardown(desc);
2725 irq_put_desc_unlock(desc, flags);
2728 int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2731 struct irq_chip *chip;
2735 chip = irq_data_get_irq_chip(data);
2736 if (WARN_ON_ONCE(!chip))
2738 if (chip->irq_get_irqchip_state)
2740 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2741 data = data->parent_data;
2748 err = chip->irq_get_irqchip_state(data, which, state);
2753 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2754 * @irq: Interrupt line that is forwarded to a VM
2755 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2756 * @state: a pointer to a boolean where the state is to be stored
2758 * This call snapshots the internal irqchip state of an
2759 * interrupt, returning into @state the bit corresponding to
2762 * This function should be called with preemption disabled if the
2763 * interrupt controller has per-cpu registers.
2765 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2768 struct irq_desc *desc;
2769 struct irq_data *data;
2770 unsigned long flags;
2773 desc = irq_get_desc_buslock(irq, &flags, 0);
2777 data = irq_desc_get_irq_data(desc);
2779 err = __irq_get_irqchip_state(data, which, state);
2781 irq_put_desc_busunlock(desc, flags);
2784 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2787 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2788 * @irq: Interrupt line that is forwarded to a VM
2789 * @which: State to be restored (one of IRQCHIP_STATE_*)
2790 * @val: Value corresponding to @which
2792 * This call sets the internal irqchip state of an interrupt,
2793 * depending on the value of @which.
2795 * This function should be called with preemption disabled if the
2796 * interrupt controller has per-cpu registers.
2798 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2801 struct irq_desc *desc;
2802 struct irq_data *data;
2803 struct irq_chip *chip;
2804 unsigned long flags;
2807 desc = irq_get_desc_buslock(irq, &flags, 0);
2811 data = irq_desc_get_irq_data(desc);
2814 chip = irq_data_get_irq_chip(data);
2815 if (WARN_ON_ONCE(!chip)) {
2819 if (chip->irq_set_irqchip_state)
2821 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2822 data = data->parent_data;
2829 err = chip->irq_set_irqchip_state(data, which, val);
2832 irq_put_desc_busunlock(desc, flags);
2835 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2838 * irq_has_action - Check whether an interrupt is requested
2839 * @irq: The linux irq number
2841 * Returns: A snapshot of the current state
2843 bool irq_has_action(unsigned int irq)
2848 res = irq_desc_has_action(irq_to_desc(irq));
2852 EXPORT_SYMBOL_GPL(irq_has_action);
2855 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2856 * @irq: The linux irq number
2857 * @bitmask: The bitmask to evaluate
2859 * Returns: True if one of the bits in @bitmask is set
2861 bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2863 struct irq_desc *desc;
2867 desc = irq_to_desc(irq);
2869 res = !!(desc->status_use_accessors & bitmask);
2873 EXPORT_SYMBOL_GPL(irq_check_status_bit);