2 * linux/kernel/irq/manage.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
7 * This file contains driver APIs to the irq subsystem.
10 #define pr_fmt(fmt) "genirq: " fmt
12 #include <linux/irq.h>
13 #include <linux/kthread.h>
14 #include <linux/module.h>
15 #include <linux/random.h>
16 #include <linux/interrupt.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 <uapi/linux/sched/types.h>
22 #include <linux/task_work.h>
24 #include "internals.h"
26 #ifdef CONFIG_IRQ_FORCED_THREADING
27 __read_mostly bool force_irqthreads;
29 static int __init setup_forced_irqthreads(char *arg)
31 force_irqthreads = true;
34 early_param("threadirqs", setup_forced_irqthreads);
37 static void __synchronize_hardirq(struct irq_desc *desc)
45 * Wait until we're out of the critical section. This might
46 * give the wrong answer due to the lack of memory barriers.
48 while (irqd_irq_inprogress(&desc->irq_data))
51 /* Ok, that indicated we're done: double-check carefully. */
52 raw_spin_lock_irqsave(&desc->lock, flags);
53 inprogress = irqd_irq_inprogress(&desc->irq_data);
54 raw_spin_unlock_irqrestore(&desc->lock, flags);
56 /* Oops, that failed? */
61 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
62 * @irq: interrupt number to wait for
64 * This function waits for any pending hard IRQ handlers for this
65 * interrupt to complete before returning. If you use this
66 * function while holding a resource the IRQ handler may need you
67 * will deadlock. It does not take associated threaded handlers
70 * Do not use this for shutdown scenarios where you must be sure
71 * that all parts (hardirq and threaded handler) have completed.
73 * Returns: false if a threaded handler is active.
75 * This function may be called - with care - from IRQ context.
77 bool synchronize_hardirq(unsigned int irq)
79 struct irq_desc *desc = irq_to_desc(irq);
82 __synchronize_hardirq(desc);
83 return !atomic_read(&desc->threads_active);
88 EXPORT_SYMBOL(synchronize_hardirq);
91 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
92 * @irq: interrupt number to wait for
94 * This function waits for any pending IRQ handlers for this interrupt
95 * to complete before returning. If you use this function while
96 * holding a resource the IRQ handler may need you will deadlock.
98 * This function may be called - with care - from IRQ context.
100 void synchronize_irq(unsigned int irq)
102 struct irq_desc *desc = irq_to_desc(irq);
105 __synchronize_hardirq(desc);
107 * We made sure that no hardirq handler is
108 * running. Now verify that no threaded handlers are
111 wait_event(desc->wait_for_threads,
112 !atomic_read(&desc->threads_active));
115 EXPORT_SYMBOL(synchronize_irq);
118 cpumask_var_t irq_default_affinity;
120 static bool __irq_can_set_affinity(struct irq_desc *desc)
122 if (!desc || !irqd_can_balance(&desc->irq_data) ||
123 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
129 * irq_can_set_affinity - Check if the affinity of a given irq can be set
130 * @irq: Interrupt to check
133 int irq_can_set_affinity(unsigned int irq)
135 return __irq_can_set_affinity(irq_to_desc(irq));
139 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
140 * @irq: Interrupt to check
142 * Like irq_can_set_affinity() above, but additionally checks for the
143 * AFFINITY_MANAGED flag.
145 bool irq_can_set_affinity_usr(unsigned int irq)
147 struct irq_desc *desc = irq_to_desc(irq);
149 return __irq_can_set_affinity(desc) &&
150 !irqd_affinity_is_managed(&desc->irq_data);
154 * irq_set_thread_affinity - Notify irq threads to adjust affinity
155 * @desc: irq descriptor which has affitnity changed
157 * We just set IRQTF_AFFINITY and delegate the affinity setting
158 * to the interrupt thread itself. We can not call
159 * set_cpus_allowed_ptr() here as we hold desc->lock and this
160 * code can be called from hard interrupt context.
162 void irq_set_thread_affinity(struct irq_desc *desc)
164 struct irqaction *action;
166 for_each_action_of_desc(desc, action)
168 set_bit(IRQTF_AFFINITY, &action->thread_flags);
171 static void irq_validate_effective_affinity(struct irq_data *data)
173 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
174 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
175 struct irq_chip *chip = irq_data_get_irq_chip(data);
177 if (!cpumask_empty(m))
179 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
180 chip->name, data->irq);
184 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
187 struct irq_desc *desc = irq_data_to_desc(data);
188 struct irq_chip *chip = irq_data_get_irq_chip(data);
191 if (!chip || !chip->irq_set_affinity)
194 ret = chip->irq_set_affinity(data, mask, force);
196 case IRQ_SET_MASK_OK:
197 case IRQ_SET_MASK_OK_DONE:
198 cpumask_copy(desc->irq_common_data.affinity, mask);
199 case IRQ_SET_MASK_OK_NOCOPY:
200 irq_validate_effective_affinity(data);
201 irq_set_thread_affinity(desc);
208 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
211 struct irq_chip *chip = irq_data_get_irq_chip(data);
212 struct irq_desc *desc = irq_data_to_desc(data);
215 if (!chip || !chip->irq_set_affinity)
218 if (irq_can_move_pcntxt(data)) {
219 ret = irq_do_set_affinity(data, mask, force);
221 irqd_set_move_pending(data);
222 irq_copy_pending(desc, mask);
225 if (desc->affinity_notify) {
226 kref_get(&desc->affinity_notify->kref);
227 schedule_work(&desc->affinity_notify->work);
229 irqd_set(data, IRQD_AFFINITY_SET);
234 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
236 struct irq_desc *desc = irq_to_desc(irq);
243 raw_spin_lock_irqsave(&desc->lock, flags);
244 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
245 raw_spin_unlock_irqrestore(&desc->lock, flags);
249 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
252 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
256 desc->affinity_hint = m;
257 irq_put_desc_unlock(desc, flags);
258 /* set the initial affinity to prevent every interrupt being on CPU0 */
260 __irq_set_affinity(irq, m, false);
263 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
265 static void irq_affinity_notify(struct work_struct *work)
267 struct irq_affinity_notify *notify =
268 container_of(work, struct irq_affinity_notify, work);
269 struct irq_desc *desc = irq_to_desc(notify->irq);
270 cpumask_var_t cpumask;
273 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
276 raw_spin_lock_irqsave(&desc->lock, flags);
277 if (irq_move_pending(&desc->irq_data))
278 irq_get_pending(cpumask, desc);
280 cpumask_copy(cpumask, desc->irq_common_data.affinity);
281 raw_spin_unlock_irqrestore(&desc->lock, flags);
283 notify->notify(notify, cpumask);
285 free_cpumask_var(cpumask);
287 kref_put(¬ify->kref, notify->release);
291 * irq_set_affinity_notifier - control notification of IRQ affinity changes
292 * @irq: Interrupt for which to enable/disable notification
293 * @notify: Context for notification, or %NULL to disable
294 * notification. Function pointers must be initialised;
295 * the other fields will be initialised by this function.
297 * Must be called in process context. Notification may only be enabled
298 * after the IRQ is allocated and must be disabled before the IRQ is
299 * freed using free_irq().
302 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
304 struct irq_desc *desc = irq_to_desc(irq);
305 struct irq_affinity_notify *old_notify;
308 /* The release function is promised process context */
314 /* Complete initialisation of *notify */
317 kref_init(¬ify->kref);
318 INIT_WORK(¬ify->work, irq_affinity_notify);
321 raw_spin_lock_irqsave(&desc->lock, flags);
322 old_notify = desc->affinity_notify;
323 desc->affinity_notify = notify;
324 raw_spin_unlock_irqrestore(&desc->lock, flags);
327 kref_put(&old_notify->kref, old_notify->release);
331 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
333 #ifndef CONFIG_AUTO_IRQ_AFFINITY
335 * Generic version of the affinity autoselector.
337 int irq_setup_affinity(struct irq_desc *desc)
339 struct cpumask *set = irq_default_affinity;
340 int ret, node = irq_desc_get_node(desc);
341 static DEFINE_RAW_SPINLOCK(mask_lock);
342 static struct cpumask mask;
344 /* Excludes PER_CPU and NO_BALANCE interrupts */
345 if (!__irq_can_set_affinity(desc))
348 raw_spin_lock(&mask_lock);
350 * Preserve the managed affinity setting and a userspace affinity
351 * setup, but make sure that one of the targets is online.
353 if (irqd_affinity_is_managed(&desc->irq_data) ||
354 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
355 if (cpumask_intersects(desc->irq_common_data.affinity,
357 set = desc->irq_common_data.affinity;
359 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
362 cpumask_and(&mask, cpu_online_mask, set);
363 if (node != NUMA_NO_NODE) {
364 const struct cpumask *nodemask = cpumask_of_node(node);
366 /* make sure at least one of the cpus in nodemask is online */
367 if (cpumask_intersects(&mask, nodemask))
368 cpumask_and(&mask, &mask, nodemask);
370 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
371 raw_spin_unlock(&mask_lock);
375 /* Wrapper for ALPHA specific affinity selector magic */
376 int irq_setup_affinity(struct irq_desc *desc)
378 return irq_select_affinity(irq_desc_get_irq(desc));
383 * Called when a bogus affinity is set via /proc/irq
385 int irq_select_affinity_usr(unsigned int irq)
387 struct irq_desc *desc = irq_to_desc(irq);
391 raw_spin_lock_irqsave(&desc->lock, flags);
392 ret = irq_setup_affinity(desc);
393 raw_spin_unlock_irqrestore(&desc->lock, flags);
399 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
400 * @irq: interrupt number to set affinity
401 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
402 * specific data for percpu_devid interrupts
404 * This function uses the vCPU specific data to set the vCPU
405 * affinity for an irq. The vCPU specific data is passed from
406 * outside, such as KVM. One example code path is as below:
407 * KVM -> IOMMU -> irq_set_vcpu_affinity().
409 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
412 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
413 struct irq_data *data;
414 struct irq_chip *chip;
420 data = irq_desc_get_irq_data(desc);
422 chip = irq_data_get_irq_chip(data);
423 if (chip && chip->irq_set_vcpu_affinity)
425 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
426 data = data->parent_data;
433 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
434 irq_put_desc_unlock(desc, flags);
438 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
440 void __disable_irq(struct irq_desc *desc)
446 static int __disable_irq_nosync(unsigned int irq)
449 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
454 irq_put_desc_busunlock(desc, flags);
459 * disable_irq_nosync - disable an irq without waiting
460 * @irq: Interrupt to disable
462 * Disable the selected interrupt line. Disables and Enables are
464 * Unlike disable_irq(), this function does not ensure existing
465 * instances of the IRQ handler have completed before returning.
467 * This function may be called from IRQ context.
469 void disable_irq_nosync(unsigned int irq)
471 __disable_irq_nosync(irq);
473 EXPORT_SYMBOL(disable_irq_nosync);
476 * disable_irq - disable an irq and wait for completion
477 * @irq: Interrupt to disable
479 * Disable the selected interrupt line. Enables and Disables are
481 * This function waits for any pending IRQ handlers for this interrupt
482 * to complete before returning. If you use this function while
483 * holding a resource the IRQ handler may need you will deadlock.
485 * This function may be called - with care - from IRQ context.
487 void disable_irq(unsigned int irq)
489 if (!__disable_irq_nosync(irq))
490 synchronize_irq(irq);
492 EXPORT_SYMBOL(disable_irq);
495 * disable_hardirq - disables an irq and waits for hardirq completion
496 * @irq: Interrupt to disable
498 * Disable the selected interrupt line. Enables and Disables are
500 * This function waits for any pending hard IRQ handlers for this
501 * interrupt to complete before returning. If you use this function while
502 * holding a resource the hard IRQ handler may need you will deadlock.
504 * When used to optimistically disable an interrupt from atomic context
505 * the return value must be checked.
507 * Returns: false if a threaded handler is active.
509 * This function may be called - with care - from IRQ context.
511 bool disable_hardirq(unsigned int irq)
513 if (!__disable_irq_nosync(irq))
514 return synchronize_hardirq(irq);
518 EXPORT_SYMBOL_GPL(disable_hardirq);
520 void __enable_irq(struct irq_desc *desc)
522 switch (desc->depth) {
525 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
526 irq_desc_get_irq(desc));
529 if (desc->istate & IRQS_SUSPENDED)
531 /* Prevent probing on this irq: */
532 irq_settings_set_noprobe(desc);
534 * Call irq_startup() not irq_enable() here because the
535 * interrupt might be marked NOAUTOEN. So irq_startup()
536 * needs to be invoked when it gets enabled the first
537 * time. If it was already started up, then irq_startup()
538 * will invoke irq_enable() under the hood.
540 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
549 * enable_irq - enable handling of an irq
550 * @irq: Interrupt to enable
552 * Undoes the effect of one call to disable_irq(). If this
553 * matches the last disable, processing of interrupts on this
554 * IRQ line is re-enabled.
556 * This function may be called from IRQ context only when
557 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
559 void enable_irq(unsigned int irq)
562 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
566 if (WARN(!desc->irq_data.chip,
567 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
572 irq_put_desc_busunlock(desc, flags);
574 EXPORT_SYMBOL(enable_irq);
576 static int set_irq_wake_real(unsigned int irq, unsigned int on)
578 struct irq_desc *desc = irq_to_desc(irq);
581 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
584 if (desc->irq_data.chip->irq_set_wake)
585 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
591 * irq_set_irq_wake - control irq power management wakeup
592 * @irq: interrupt to control
593 * @on: enable/disable power management wakeup
595 * Enable/disable power management wakeup mode, which is
596 * disabled by default. Enables and disables must match,
597 * just as they match for non-wakeup mode support.
599 * Wakeup mode lets this IRQ wake the system from sleep
600 * states like "suspend to RAM".
602 int irq_set_irq_wake(unsigned int irq, unsigned int on)
605 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
611 /* wakeup-capable irqs can be shared between drivers that
612 * don't need to have the same sleep mode behaviors.
615 if (desc->wake_depth++ == 0) {
616 ret = set_irq_wake_real(irq, on);
618 desc->wake_depth = 0;
620 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
623 if (desc->wake_depth == 0) {
624 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
625 } else if (--desc->wake_depth == 0) {
626 ret = set_irq_wake_real(irq, on);
628 desc->wake_depth = 1;
630 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
633 irq_put_desc_busunlock(desc, flags);
636 EXPORT_SYMBOL(irq_set_irq_wake);
639 * Internal function that tells the architecture code whether a
640 * particular irq has been exclusively allocated or is available
643 int can_request_irq(unsigned int irq, unsigned long irqflags)
646 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
652 if (irq_settings_can_request(desc)) {
654 irqflags & desc->action->flags & IRQF_SHARED)
657 irq_put_desc_unlock(desc, flags);
661 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
663 struct irq_chip *chip = desc->irq_data.chip;
666 if (!chip || !chip->irq_set_type) {
668 * IRQF_TRIGGER_* but the PIC does not support multiple
671 pr_debug("No set_type function for IRQ %d (%s)\n",
672 irq_desc_get_irq(desc),
673 chip ? (chip->name ? : "unknown") : "unknown");
677 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
678 if (!irqd_irq_masked(&desc->irq_data))
680 if (!irqd_irq_disabled(&desc->irq_data))
684 /* Mask all flags except trigger mode */
685 flags &= IRQ_TYPE_SENSE_MASK;
686 ret = chip->irq_set_type(&desc->irq_data, flags);
689 case IRQ_SET_MASK_OK:
690 case IRQ_SET_MASK_OK_DONE:
691 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
692 irqd_set(&desc->irq_data, flags);
694 case IRQ_SET_MASK_OK_NOCOPY:
695 flags = irqd_get_trigger_type(&desc->irq_data);
696 irq_settings_set_trigger_mask(desc, flags);
697 irqd_clear(&desc->irq_data, IRQD_LEVEL);
698 irq_settings_clr_level(desc);
699 if (flags & IRQ_TYPE_LEVEL_MASK) {
700 irq_settings_set_level(desc);
701 irqd_set(&desc->irq_data, IRQD_LEVEL);
707 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
708 flags, irq_desc_get_irq(desc), chip->irq_set_type);
715 #ifdef CONFIG_HARDIRQS_SW_RESEND
716 int irq_set_parent(int irq, int parent_irq)
719 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
724 desc->parent_irq = parent_irq;
726 irq_put_desc_unlock(desc, flags);
729 EXPORT_SYMBOL_GPL(irq_set_parent);
733 * Default primary interrupt handler for threaded interrupts. Is
734 * assigned as primary handler when request_threaded_irq is called
735 * with handler == NULL. Useful for oneshot interrupts.
737 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
739 return IRQ_WAKE_THREAD;
743 * Primary handler for nested threaded interrupts. Should never be
746 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
748 WARN(1, "Primary handler called for nested irq %d\n", irq);
752 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
754 WARN(1, "Secondary action handler called for irq %d\n", irq);
758 static int irq_wait_for_interrupt(struct irqaction *action)
760 set_current_state(TASK_INTERRUPTIBLE);
762 while (!kthread_should_stop()) {
764 if (test_and_clear_bit(IRQTF_RUNTHREAD,
765 &action->thread_flags)) {
766 __set_current_state(TASK_RUNNING);
770 set_current_state(TASK_INTERRUPTIBLE);
772 __set_current_state(TASK_RUNNING);
777 * Oneshot interrupts keep the irq line masked until the threaded
778 * handler finished. unmask if the interrupt has not been disabled and
781 static void irq_finalize_oneshot(struct irq_desc *desc,
782 struct irqaction *action)
784 if (!(desc->istate & IRQS_ONESHOT) ||
785 action->handler == irq_forced_secondary_handler)
789 raw_spin_lock_irq(&desc->lock);
792 * Implausible though it may be we need to protect us against
793 * the following scenario:
795 * The thread is faster done than the hard interrupt handler
796 * on the other CPU. If we unmask the irq line then the
797 * interrupt can come in again and masks the line, leaves due
798 * to IRQS_INPROGRESS and the irq line is masked forever.
800 * This also serializes the state of shared oneshot handlers
801 * versus "desc->threads_onehsot |= action->thread_mask;" in
802 * irq_wake_thread(). See the comment there which explains the
805 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
806 raw_spin_unlock_irq(&desc->lock);
807 chip_bus_sync_unlock(desc);
813 * Now check again, whether the thread should run. Otherwise
814 * we would clear the threads_oneshot bit of this thread which
817 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
820 desc->threads_oneshot &= ~action->thread_mask;
822 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
823 irqd_irq_masked(&desc->irq_data))
824 unmask_threaded_irq(desc);
827 raw_spin_unlock_irq(&desc->lock);
828 chip_bus_sync_unlock(desc);
833 * Check whether we need to change the affinity of the interrupt thread.
836 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
841 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
845 * In case we are out of memory we set IRQTF_AFFINITY again and
846 * try again next time
848 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
849 set_bit(IRQTF_AFFINITY, &action->thread_flags);
853 raw_spin_lock_irq(&desc->lock);
855 * This code is triggered unconditionally. Check the affinity
856 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
858 if (cpumask_available(desc->irq_common_data.affinity)) {
859 const struct cpumask *m;
861 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
862 cpumask_copy(mask, m);
866 raw_spin_unlock_irq(&desc->lock);
869 set_cpus_allowed_ptr(current, mask);
870 free_cpumask_var(mask);
874 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
878 * Interrupts which are not explicitely requested as threaded
879 * interrupts rely on the implicit bh/preempt disable of the hard irq
880 * context. So we need to disable bh here to avoid deadlocks and other
884 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
889 ret = action->thread_fn(action->irq, action->dev_id);
890 irq_finalize_oneshot(desc, action);
896 * Interrupts explicitly requested as threaded interrupts want to be
897 * preemtible - many of them need to sleep and wait for slow busses to
900 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
901 struct irqaction *action)
905 ret = action->thread_fn(action->irq, action->dev_id);
906 irq_finalize_oneshot(desc, action);
910 static void wake_threads_waitq(struct irq_desc *desc)
912 if (atomic_dec_and_test(&desc->threads_active))
913 wake_up(&desc->wait_for_threads);
916 static void irq_thread_dtor(struct callback_head *unused)
918 struct task_struct *tsk = current;
919 struct irq_desc *desc;
920 struct irqaction *action;
922 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
925 action = kthread_data(tsk);
927 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
928 tsk->comm, tsk->pid, action->irq);
931 desc = irq_to_desc(action->irq);
933 * If IRQTF_RUNTHREAD is set, we need to decrement
934 * desc->threads_active and wake possible waiters.
936 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
937 wake_threads_waitq(desc);
939 /* Prevent a stale desc->threads_oneshot */
940 irq_finalize_oneshot(desc, action);
943 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
945 struct irqaction *secondary = action->secondary;
947 if (WARN_ON_ONCE(!secondary))
950 raw_spin_lock_irq(&desc->lock);
951 __irq_wake_thread(desc, secondary);
952 raw_spin_unlock_irq(&desc->lock);
956 * Interrupt handler thread
958 static int irq_thread(void *data)
960 struct callback_head on_exit_work;
961 struct irqaction *action = data;
962 struct irq_desc *desc = irq_to_desc(action->irq);
963 irqreturn_t (*handler_fn)(struct irq_desc *desc,
964 struct irqaction *action);
966 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
967 &action->thread_flags))
968 handler_fn = irq_forced_thread_fn;
970 handler_fn = irq_thread_fn;
972 init_task_work(&on_exit_work, irq_thread_dtor);
973 task_work_add(current, &on_exit_work, false);
975 irq_thread_check_affinity(desc, action);
977 while (!irq_wait_for_interrupt(action)) {
978 irqreturn_t action_ret;
980 irq_thread_check_affinity(desc, action);
982 action_ret = handler_fn(desc, action);
983 if (action_ret == IRQ_HANDLED)
984 atomic_inc(&desc->threads_handled);
985 if (action_ret == IRQ_WAKE_THREAD)
986 irq_wake_secondary(desc, action);
988 wake_threads_waitq(desc);
992 * This is the regular exit path. __free_irq() is stopping the
993 * thread via kthread_stop() after calling
994 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
995 * oneshot mask bit can be set. We cannot verify that as we
996 * cannot touch the oneshot mask at this point anymore as
997 * __setup_irq() might have given out currents thread_mask
1000 task_work_cancel(current, irq_thread_dtor);
1005 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1006 * @irq: Interrupt line
1007 * @dev_id: Device identity for which the thread should be woken
1010 void irq_wake_thread(unsigned int irq, void *dev_id)
1012 struct irq_desc *desc = irq_to_desc(irq);
1013 struct irqaction *action;
1014 unsigned long flags;
1016 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1019 raw_spin_lock_irqsave(&desc->lock, flags);
1020 for_each_action_of_desc(desc, action) {
1021 if (action->dev_id == dev_id) {
1023 __irq_wake_thread(desc, action);
1027 raw_spin_unlock_irqrestore(&desc->lock, flags);
1029 EXPORT_SYMBOL_GPL(irq_wake_thread);
1031 static int irq_setup_forced_threading(struct irqaction *new)
1033 if (!force_irqthreads)
1035 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1038 new->flags |= IRQF_ONESHOT;
1041 * Handle the case where we have a real primary handler and a
1042 * thread handler. We force thread them as well by creating a
1045 if (new->handler != irq_default_primary_handler && new->thread_fn) {
1046 /* Allocate the secondary action */
1047 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1048 if (!new->secondary)
1050 new->secondary->handler = irq_forced_secondary_handler;
1051 new->secondary->thread_fn = new->thread_fn;
1052 new->secondary->dev_id = new->dev_id;
1053 new->secondary->irq = new->irq;
1054 new->secondary->name = new->name;
1056 /* Deal with the primary handler */
1057 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1058 new->thread_fn = new->handler;
1059 new->handler = irq_default_primary_handler;
1063 static int irq_request_resources(struct irq_desc *desc)
1065 struct irq_data *d = &desc->irq_data;
1066 struct irq_chip *c = d->chip;
1068 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1071 static void irq_release_resources(struct irq_desc *desc)
1073 struct irq_data *d = &desc->irq_data;
1074 struct irq_chip *c = d->chip;
1076 if (c->irq_release_resources)
1077 c->irq_release_resources(d);
1081 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1083 struct task_struct *t;
1084 struct sched_param param = {
1085 .sched_priority = MAX_USER_RT_PRIO/2,
1089 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1092 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1094 param.sched_priority -= 1;
1100 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1103 * We keep the reference to the task struct even if
1104 * the thread dies to avoid that the interrupt code
1105 * references an already freed task_struct.
1110 * Tell the thread to set its affinity. This is
1111 * important for shared interrupt handlers as we do
1112 * not invoke setup_affinity() for the secondary
1113 * handlers as everything is already set up. Even for
1114 * interrupts marked with IRQF_NO_BALANCE this is
1115 * correct as we want the thread to move to the cpu(s)
1116 * on which the requesting code placed the interrupt.
1118 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1123 * Internal function to register an irqaction - typically used to
1124 * allocate special interrupts that are part of the architecture.
1128 * desc->request_mutex Provides serialization against a concurrent free_irq()
1129 * chip_bus_lock Provides serialization for slow bus operations
1130 * desc->lock Provides serialization against hard interrupts
1132 * chip_bus_lock and desc->lock are sufficient for all other management and
1133 * interrupt related functions. desc->request_mutex solely serializes
1134 * request/free_irq().
1137 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1139 struct irqaction *old, **old_ptr;
1140 unsigned long flags, thread_mask = 0;
1141 int ret, nested, shared = 0;
1146 if (desc->irq_data.chip == &no_irq_chip)
1148 if (!try_module_get(desc->owner))
1154 * If the trigger type is not specified by the caller,
1155 * then use the default for this interrupt.
1157 if (!(new->flags & IRQF_TRIGGER_MASK))
1158 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1161 * Check whether the interrupt nests into another interrupt
1164 nested = irq_settings_is_nested_thread(desc);
1166 if (!new->thread_fn) {
1171 * Replace the primary handler which was provided from
1172 * the driver for non nested interrupt handling by the
1173 * dummy function which warns when called.
1175 new->handler = irq_nested_primary_handler;
1177 if (irq_settings_can_thread(desc)) {
1178 ret = irq_setup_forced_threading(new);
1185 * Create a handler thread when a thread function is supplied
1186 * and the interrupt does not nest into another interrupt
1189 if (new->thread_fn && !nested) {
1190 ret = setup_irq_thread(new, irq, false);
1193 if (new->secondary) {
1194 ret = setup_irq_thread(new->secondary, irq, true);
1201 * Drivers are often written to work w/o knowledge about the
1202 * underlying irq chip implementation, so a request for a
1203 * threaded irq without a primary hard irq context handler
1204 * requires the ONESHOT flag to be set. Some irq chips like
1205 * MSI based interrupts are per se one shot safe. Check the
1206 * chip flags, so we can avoid the unmask dance at the end of
1207 * the threaded handler for those.
1209 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1210 new->flags &= ~IRQF_ONESHOT;
1213 * Protects against a concurrent __free_irq() call which might wait
1214 * for synchronize_irq() to complete without holding the optional
1215 * chip bus lock and desc->lock.
1217 mutex_lock(&desc->request_mutex);
1220 * Acquire bus lock as the irq_request_resources() callback below
1221 * might rely on the serialization or the magic power management
1222 * functions which are abusing the irq_bus_lock() callback,
1224 chip_bus_lock(desc);
1226 /* First installed action requests resources. */
1227 if (!desc->action) {
1228 ret = irq_request_resources(desc);
1230 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1231 new->name, irq, desc->irq_data.chip->name);
1232 goto out_bus_unlock;
1237 * The following block of code has to be executed atomically
1238 * protected against a concurrent interrupt and any of the other
1239 * management calls which are not serialized via
1240 * desc->request_mutex or the optional bus lock.
1242 raw_spin_lock_irqsave(&desc->lock, flags);
1243 old_ptr = &desc->action;
1247 * Can't share interrupts unless both agree to and are
1248 * the same type (level, edge, polarity). So both flag
1249 * fields must have IRQF_SHARED set and the bits which
1250 * set the trigger type must match. Also all must
1253 unsigned int oldtype;
1256 * If nobody did set the configuration before, inherit
1257 * the one provided by the requester.
1259 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1260 oldtype = irqd_get_trigger_type(&desc->irq_data);
1262 oldtype = new->flags & IRQF_TRIGGER_MASK;
1263 irqd_set_trigger_type(&desc->irq_data, oldtype);
1266 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1267 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1268 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1271 /* All handlers must agree on per-cpuness */
1272 if ((old->flags & IRQF_PERCPU) !=
1273 (new->flags & IRQF_PERCPU))
1276 /* add new interrupt at end of irq queue */
1279 * Or all existing action->thread_mask bits,
1280 * so we can find the next zero bit for this
1283 thread_mask |= old->thread_mask;
1284 old_ptr = &old->next;
1291 * Setup the thread mask for this irqaction for ONESHOT. For
1292 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1293 * conditional in irq_wake_thread().
1295 if (new->flags & IRQF_ONESHOT) {
1297 * Unlikely to have 32 resp 64 irqs sharing one line,
1300 if (thread_mask == ~0UL) {
1305 * The thread_mask for the action is or'ed to
1306 * desc->thread_active to indicate that the
1307 * IRQF_ONESHOT thread handler has been woken, but not
1308 * yet finished. The bit is cleared when a thread
1309 * completes. When all threads of a shared interrupt
1310 * line have completed desc->threads_active becomes
1311 * zero and the interrupt line is unmasked. See
1312 * handle.c:irq_wake_thread() for further information.
1314 * If no thread is woken by primary (hard irq context)
1315 * interrupt handlers, then desc->threads_active is
1316 * also checked for zero to unmask the irq line in the
1317 * affected hard irq flow handlers
1318 * (handle_[fasteoi|level]_irq).
1320 * The new action gets the first zero bit of
1321 * thread_mask assigned. See the loop above which or's
1322 * all existing action->thread_mask bits.
1324 new->thread_mask = 1UL << ffz(thread_mask);
1326 } else if (new->handler == irq_default_primary_handler &&
1327 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1329 * The interrupt was requested with handler = NULL, so
1330 * we use the default primary handler for it. But it
1331 * does not have the oneshot flag set. In combination
1332 * with level interrupts this is deadly, because the
1333 * default primary handler just wakes the thread, then
1334 * the irq lines is reenabled, but the device still
1335 * has the level irq asserted. Rinse and repeat....
1337 * While this works for edge type interrupts, we play
1338 * it safe and reject unconditionally because we can't
1339 * say for sure which type this interrupt really
1340 * has. The type flags are unreliable as the
1341 * underlying chip implementation can override them.
1343 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1350 init_waitqueue_head(&desc->wait_for_threads);
1352 /* Setup the type (level, edge polarity) if configured: */
1353 if (new->flags & IRQF_TRIGGER_MASK) {
1354 ret = __irq_set_trigger(desc,
1355 new->flags & IRQF_TRIGGER_MASK);
1362 * Activate the interrupt. That activation must happen
1363 * independently of IRQ_NOAUTOEN. request_irq() can fail
1364 * and the callers are supposed to handle
1365 * that. enable_irq() of an interrupt requested with
1366 * IRQ_NOAUTOEN is not supposed to fail. The activation
1367 * keeps it in shutdown mode, it merily associates
1368 * resources if necessary and if that's not possible it
1369 * fails. Interrupts which are in managed shutdown mode
1370 * will simply ignore that activation request.
1372 ret = irq_activate(desc);
1376 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1377 IRQS_ONESHOT | IRQS_WAITING);
1378 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1380 if (new->flags & IRQF_PERCPU) {
1381 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1382 irq_settings_set_per_cpu(desc);
1385 if (new->flags & IRQF_ONESHOT)
1386 desc->istate |= IRQS_ONESHOT;
1388 /* Exclude IRQ from balancing if requested */
1389 if (new->flags & IRQF_NOBALANCING) {
1390 irq_settings_set_no_balancing(desc);
1391 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1394 if (irq_settings_can_autoenable(desc)) {
1395 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1398 * Shared interrupts do not go well with disabling
1399 * auto enable. The sharing interrupt might request
1400 * it while it's still disabled and then wait for
1401 * interrupts forever.
1403 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1404 /* Undo nested disables: */
1408 } else if (new->flags & IRQF_TRIGGER_MASK) {
1409 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1410 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1413 /* hope the handler works with current trigger mode */
1414 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1420 irq_pm_install_action(desc, new);
1422 /* Reset broken irq detection when installing new handler */
1423 desc->irq_count = 0;
1424 desc->irqs_unhandled = 0;
1427 * Check whether we disabled the irq via the spurious handler
1428 * before. Reenable it and give it another chance.
1430 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1431 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1435 raw_spin_unlock_irqrestore(&desc->lock, flags);
1436 chip_bus_sync_unlock(desc);
1437 mutex_unlock(&desc->request_mutex);
1439 irq_setup_timings(desc, new);
1442 * Strictly no need to wake it up, but hung_task complains
1443 * when no hard interrupt wakes the thread up.
1446 wake_up_process(new->thread);
1448 wake_up_process(new->secondary->thread);
1450 register_irq_proc(irq, desc);
1452 register_handler_proc(irq, new);
1456 if (!(new->flags & IRQF_PROBE_SHARED)) {
1457 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1458 irq, new->flags, new->name, old->flags, old->name);
1459 #ifdef CONFIG_DEBUG_SHIRQ
1466 raw_spin_unlock_irqrestore(&desc->lock, flags);
1469 irq_release_resources(desc);
1471 chip_bus_sync_unlock(desc);
1472 mutex_unlock(&desc->request_mutex);
1476 struct task_struct *t = new->thread;
1482 if (new->secondary && new->secondary->thread) {
1483 struct task_struct *t = new->secondary->thread;
1485 new->secondary->thread = NULL;
1490 module_put(desc->owner);
1495 * setup_irq - setup an interrupt
1496 * @irq: Interrupt line to setup
1497 * @act: irqaction for the interrupt
1499 * Used to statically setup interrupts in the early boot process.
1501 int setup_irq(unsigned int irq, struct irqaction *act)
1504 struct irq_desc *desc = irq_to_desc(irq);
1506 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1509 retval = irq_chip_pm_get(&desc->irq_data);
1513 retval = __setup_irq(irq, desc, act);
1516 irq_chip_pm_put(&desc->irq_data);
1520 EXPORT_SYMBOL_GPL(setup_irq);
1523 * Internal function to unregister an irqaction - used to free
1524 * regular and special interrupts that are part of the architecture.
1526 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1528 struct irq_desc *desc = irq_to_desc(irq);
1529 struct irqaction *action, **action_ptr;
1530 unsigned long flags;
1532 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1537 mutex_lock(&desc->request_mutex);
1538 chip_bus_lock(desc);
1539 raw_spin_lock_irqsave(&desc->lock, flags);
1542 * There can be multiple actions per IRQ descriptor, find the right
1543 * one based on the dev_id:
1545 action_ptr = &desc->action;
1547 action = *action_ptr;
1550 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1551 raw_spin_unlock_irqrestore(&desc->lock, flags);
1552 chip_bus_sync_unlock(desc);
1553 mutex_unlock(&desc->request_mutex);
1557 if (action->dev_id == dev_id)
1559 action_ptr = &action->next;
1562 /* Found it - now remove it from the list of entries: */
1563 *action_ptr = action->next;
1565 irq_pm_remove_action(desc, action);
1567 /* If this was the last handler, shut down the IRQ line: */
1568 if (!desc->action) {
1569 irq_settings_clr_disable_unlazy(desc);
1574 /* make sure affinity_hint is cleaned up */
1575 if (WARN_ON_ONCE(desc->affinity_hint))
1576 desc->affinity_hint = NULL;
1579 raw_spin_unlock_irqrestore(&desc->lock, flags);
1581 * Drop bus_lock here so the changes which were done in the chip
1582 * callbacks above are synced out to the irq chips which hang
1583 * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1585 * Aside of that the bus_lock can also be taken from the threaded
1586 * handler in irq_finalize_oneshot() which results in a deadlock
1587 * because synchronize_irq() would wait forever for the thread to
1588 * complete, which is blocked on the bus lock.
1590 * The still held desc->request_mutex() protects against a
1591 * concurrent request_irq() of this irq so the release of resources
1592 * and timing data is properly serialized.
1594 chip_bus_sync_unlock(desc);
1596 unregister_handler_proc(irq, action);
1598 /* Make sure it's not being used on another CPU: */
1599 synchronize_irq(irq);
1601 #ifdef CONFIG_DEBUG_SHIRQ
1603 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1604 * event to happen even now it's being freed, so let's make sure that
1605 * is so by doing an extra call to the handler ....
1607 * ( We do this after actually deregistering it, to make sure that a
1608 * 'real' IRQ doesn't run in * parallel with our fake. )
1610 if (action->flags & IRQF_SHARED) {
1611 local_irq_save(flags);
1612 action->handler(irq, dev_id);
1613 local_irq_restore(flags);
1617 if (action->thread) {
1618 kthread_stop(action->thread);
1619 put_task_struct(action->thread);
1620 if (action->secondary && action->secondary->thread) {
1621 kthread_stop(action->secondary->thread);
1622 put_task_struct(action->secondary->thread);
1626 /* Last action releases resources */
1627 if (!desc->action) {
1629 * Reaquire bus lock as irq_release_resources() might
1630 * require it to deallocate resources over the slow bus.
1632 chip_bus_lock(desc);
1633 irq_release_resources(desc);
1634 chip_bus_sync_unlock(desc);
1635 irq_remove_timings(desc);
1638 mutex_unlock(&desc->request_mutex);
1640 irq_chip_pm_put(&desc->irq_data);
1641 module_put(desc->owner);
1642 kfree(action->secondary);
1647 * remove_irq - free an interrupt
1648 * @irq: Interrupt line to free
1649 * @act: irqaction for the interrupt
1651 * Used to remove interrupts statically setup by the early boot process.
1653 void remove_irq(unsigned int irq, struct irqaction *act)
1655 struct irq_desc *desc = irq_to_desc(irq);
1657 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1658 __free_irq(irq, act->dev_id);
1660 EXPORT_SYMBOL_GPL(remove_irq);
1663 * free_irq - free an interrupt allocated with request_irq
1664 * @irq: Interrupt line to free
1665 * @dev_id: Device identity to free
1667 * Remove an interrupt handler. The handler is removed and if the
1668 * interrupt line is no longer in use by any driver it is disabled.
1669 * On a shared IRQ the caller must ensure the interrupt is disabled
1670 * on the card it drives before calling this function. The function
1671 * does not return until any executing interrupts for this IRQ
1674 * This function must not be called from interrupt context.
1676 * Returns the devname argument passed to request_irq.
1678 const void *free_irq(unsigned int irq, void *dev_id)
1680 struct irq_desc *desc = irq_to_desc(irq);
1681 struct irqaction *action;
1682 const char *devname;
1684 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1688 if (WARN_ON(desc->affinity_notify))
1689 desc->affinity_notify = NULL;
1692 action = __free_irq(irq, dev_id);
1697 devname = action->name;
1701 EXPORT_SYMBOL(free_irq);
1704 * request_threaded_irq - allocate an interrupt line
1705 * @irq: Interrupt line to allocate
1706 * @handler: Function to be called when the IRQ occurs.
1707 * Primary handler for threaded interrupts
1708 * If NULL and thread_fn != NULL the default
1709 * primary handler is installed
1710 * @thread_fn: Function called from the irq handler thread
1711 * If NULL, no irq thread is created
1712 * @irqflags: Interrupt type flags
1713 * @devname: An ascii name for the claiming device
1714 * @dev_id: A cookie passed back to the handler function
1716 * This call allocates interrupt resources and enables the
1717 * interrupt line and IRQ handling. From the point this
1718 * call is made your handler function may be invoked. Since
1719 * your handler function must clear any interrupt the board
1720 * raises, you must take care both to initialise your hardware
1721 * and to set up the interrupt handler in the right order.
1723 * If you want to set up a threaded irq handler for your device
1724 * then you need to supply @handler and @thread_fn. @handler is
1725 * still called in hard interrupt context and has to check
1726 * whether the interrupt originates from the device. If yes it
1727 * needs to disable the interrupt on the device and return
1728 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1729 * @thread_fn. This split handler design is necessary to support
1730 * shared interrupts.
1732 * Dev_id must be globally unique. Normally the address of the
1733 * device data structure is used as the cookie. Since the handler
1734 * receives this value it makes sense to use it.
1736 * If your interrupt is shared you must pass a non NULL dev_id
1737 * as this is required when freeing the interrupt.
1741 * IRQF_SHARED Interrupt is shared
1742 * IRQF_TRIGGER_* Specify active edge(s) or level
1745 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1746 irq_handler_t thread_fn, unsigned long irqflags,
1747 const char *devname, void *dev_id)
1749 struct irqaction *action;
1750 struct irq_desc *desc;
1753 if (irq == IRQ_NOTCONNECTED)
1757 * Sanity-check: shared interrupts must pass in a real dev-ID,
1758 * otherwise we'll have trouble later trying to figure out
1759 * which interrupt is which (messes up the interrupt freeing
1762 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1763 * it cannot be set along with IRQF_NO_SUSPEND.
1765 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1766 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1767 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1770 desc = irq_to_desc(irq);
1774 if (!irq_settings_can_request(desc) ||
1775 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1781 handler = irq_default_primary_handler;
1784 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1788 action->handler = handler;
1789 action->thread_fn = thread_fn;
1790 action->flags = irqflags;
1791 action->name = devname;
1792 action->dev_id = dev_id;
1794 retval = irq_chip_pm_get(&desc->irq_data);
1800 retval = __setup_irq(irq, desc, action);
1803 irq_chip_pm_put(&desc->irq_data);
1804 kfree(action->secondary);
1808 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1809 if (!retval && (irqflags & IRQF_SHARED)) {
1811 * It's a shared IRQ -- the driver ought to be prepared for it
1812 * to happen immediately, so let's make sure....
1813 * We disable the irq to make sure that a 'real' IRQ doesn't
1814 * run in parallel with our fake.
1816 unsigned long flags;
1819 local_irq_save(flags);
1821 handler(irq, dev_id);
1823 local_irq_restore(flags);
1829 EXPORT_SYMBOL(request_threaded_irq);
1832 * request_any_context_irq - allocate an interrupt line
1833 * @irq: Interrupt line to allocate
1834 * @handler: Function to be called when the IRQ occurs.
1835 * Threaded handler for threaded interrupts.
1836 * @flags: Interrupt type flags
1837 * @name: An ascii name for the claiming device
1838 * @dev_id: A cookie passed back to the handler function
1840 * This call allocates interrupt resources and enables the
1841 * interrupt line and IRQ handling. It selects either a
1842 * hardirq or threaded handling method depending on the
1845 * On failure, it returns a negative value. On success,
1846 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1848 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1849 unsigned long flags, const char *name, void *dev_id)
1851 struct irq_desc *desc;
1854 if (irq == IRQ_NOTCONNECTED)
1857 desc = irq_to_desc(irq);
1861 if (irq_settings_is_nested_thread(desc)) {
1862 ret = request_threaded_irq(irq, NULL, handler,
1863 flags, name, dev_id);
1864 return !ret ? IRQC_IS_NESTED : ret;
1867 ret = request_irq(irq, handler, flags, name, dev_id);
1868 return !ret ? IRQC_IS_HARDIRQ : ret;
1870 EXPORT_SYMBOL_GPL(request_any_context_irq);
1872 void enable_percpu_irq(unsigned int irq, unsigned int type)
1874 unsigned int cpu = smp_processor_id();
1875 unsigned long flags;
1876 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1882 * If the trigger type is not specified by the caller, then
1883 * use the default for this interrupt.
1885 type &= IRQ_TYPE_SENSE_MASK;
1886 if (type == IRQ_TYPE_NONE)
1887 type = irqd_get_trigger_type(&desc->irq_data);
1889 if (type != IRQ_TYPE_NONE) {
1892 ret = __irq_set_trigger(desc, type);
1895 WARN(1, "failed to set type for IRQ%d\n", irq);
1900 irq_percpu_enable(desc, cpu);
1902 irq_put_desc_unlock(desc, flags);
1904 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1907 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1908 * @irq: Linux irq number to check for
1910 * Must be called from a non migratable context. Returns the enable
1911 * state of a per cpu interrupt on the current cpu.
1913 bool irq_percpu_is_enabled(unsigned int irq)
1915 unsigned int cpu = smp_processor_id();
1916 struct irq_desc *desc;
1917 unsigned long flags;
1920 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1924 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1925 irq_put_desc_unlock(desc, flags);
1929 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1931 void disable_percpu_irq(unsigned int irq)
1933 unsigned int cpu = smp_processor_id();
1934 unsigned long flags;
1935 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1940 irq_percpu_disable(desc, cpu);
1941 irq_put_desc_unlock(desc, flags);
1943 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1946 * Internal function to unregister a percpu irqaction.
1948 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1950 struct irq_desc *desc = irq_to_desc(irq);
1951 struct irqaction *action;
1952 unsigned long flags;
1954 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1959 raw_spin_lock_irqsave(&desc->lock, flags);
1961 action = desc->action;
1962 if (!action || action->percpu_dev_id != dev_id) {
1963 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1967 if (!cpumask_empty(desc->percpu_enabled)) {
1968 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1969 irq, cpumask_first(desc->percpu_enabled));
1973 /* Found it - now remove it from the list of entries: */
1974 desc->action = NULL;
1976 raw_spin_unlock_irqrestore(&desc->lock, flags);
1978 unregister_handler_proc(irq, action);
1980 irq_chip_pm_put(&desc->irq_data);
1981 module_put(desc->owner);
1985 raw_spin_unlock_irqrestore(&desc->lock, flags);
1990 * remove_percpu_irq - free a per-cpu interrupt
1991 * @irq: Interrupt line to free
1992 * @act: irqaction for the interrupt
1994 * Used to remove interrupts statically setup by the early boot process.
1996 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1998 struct irq_desc *desc = irq_to_desc(irq);
2000 if (desc && irq_settings_is_per_cpu_devid(desc))
2001 __free_percpu_irq(irq, act->percpu_dev_id);
2005 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2006 * @irq: Interrupt line to free
2007 * @dev_id: Device identity to free
2009 * Remove a percpu interrupt handler. The handler is removed, but
2010 * the interrupt line is not disabled. This must be done on each
2011 * CPU before calling this function. The function does not return
2012 * until any executing interrupts for this IRQ have completed.
2014 * This function must not be called from interrupt context.
2016 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2018 struct irq_desc *desc = irq_to_desc(irq);
2020 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2023 chip_bus_lock(desc);
2024 kfree(__free_percpu_irq(irq, dev_id));
2025 chip_bus_sync_unlock(desc);
2027 EXPORT_SYMBOL_GPL(free_percpu_irq);
2030 * setup_percpu_irq - setup a per-cpu interrupt
2031 * @irq: Interrupt line to setup
2032 * @act: irqaction for the interrupt
2034 * Used to statically setup per-cpu interrupts in the early boot process.
2036 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2038 struct irq_desc *desc = irq_to_desc(irq);
2041 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2044 retval = irq_chip_pm_get(&desc->irq_data);
2048 retval = __setup_irq(irq, desc, act);
2051 irq_chip_pm_put(&desc->irq_data);
2057 * __request_percpu_irq - allocate a percpu interrupt line
2058 * @irq: Interrupt line to allocate
2059 * @handler: Function to be called when the IRQ occurs.
2060 * @flags: Interrupt type flags (IRQF_TIMER only)
2061 * @devname: An ascii name for the claiming device
2062 * @dev_id: A percpu cookie passed back to the handler function
2064 * This call allocates interrupt resources and enables the
2065 * interrupt on the local CPU. If the interrupt is supposed to be
2066 * enabled on other CPUs, it has to be done on each CPU using
2067 * enable_percpu_irq().
2069 * Dev_id must be globally unique. It is a per-cpu variable, and
2070 * the handler gets called with the interrupted CPU's instance of
2073 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2074 unsigned long flags, const char *devname,
2075 void __percpu *dev_id)
2077 struct irqaction *action;
2078 struct irq_desc *desc;
2084 desc = irq_to_desc(irq);
2085 if (!desc || !irq_settings_can_request(desc) ||
2086 !irq_settings_is_per_cpu_devid(desc))
2089 if (flags && flags != IRQF_TIMER)
2092 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2096 action->handler = handler;
2097 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2098 action->name = devname;
2099 action->percpu_dev_id = dev_id;
2101 retval = irq_chip_pm_get(&desc->irq_data);
2107 retval = __setup_irq(irq, desc, action);
2110 irq_chip_pm_put(&desc->irq_data);
2116 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2119 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2120 * @irq: Interrupt line that is forwarded to a VM
2121 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2122 * @state: a pointer to a boolean where the state is to be storeed
2124 * This call snapshots the internal irqchip state of an
2125 * interrupt, returning into @state the bit corresponding to
2128 * This function should be called with preemption disabled if the
2129 * interrupt controller has per-cpu registers.
2131 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2134 struct irq_desc *desc;
2135 struct irq_data *data;
2136 struct irq_chip *chip;
2137 unsigned long flags;
2140 desc = irq_get_desc_buslock(irq, &flags, 0);
2144 data = irq_desc_get_irq_data(desc);
2147 chip = irq_data_get_irq_chip(data);
2148 if (chip->irq_get_irqchip_state)
2150 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2151 data = data->parent_data;
2158 err = chip->irq_get_irqchip_state(data, which, state);
2160 irq_put_desc_busunlock(desc, flags);
2163 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2166 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2167 * @irq: Interrupt line that is forwarded to a VM
2168 * @which: State to be restored (one of IRQCHIP_STATE_*)
2169 * @val: Value corresponding to @which
2171 * This call sets the internal irqchip state of an interrupt,
2172 * depending on the value of @which.
2174 * This function should be called with preemption disabled if the
2175 * interrupt controller has per-cpu registers.
2177 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2180 struct irq_desc *desc;
2181 struct irq_data *data;
2182 struct irq_chip *chip;
2183 unsigned long flags;
2186 desc = irq_get_desc_buslock(irq, &flags, 0);
2190 data = irq_desc_get_irq_data(desc);
2193 chip = irq_data_get_irq_chip(data);
2194 if (chip->irq_set_irqchip_state)
2196 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2197 data = data->parent_data;
2204 err = chip->irq_set_irqchip_state(data, which, val);
2206 irq_put_desc_busunlock(desc, flags);
2209 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);