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/task_work.h>
22 #include "internals.h"
24 #ifdef CONFIG_IRQ_FORCED_THREADING
25 __read_mostly bool force_irqthreads;
27 static int __init setup_forced_irqthreads(char *arg)
29 force_irqthreads = true;
32 early_param("threadirqs", setup_forced_irqthreads);
35 static void __synchronize_hardirq(struct irq_desc *desc)
43 * Wait until we're out of the critical section. This might
44 * give the wrong answer due to the lack of memory barriers.
46 while (irqd_irq_inprogress(&desc->irq_data))
49 /* Ok, that indicated we're done: double-check carefully. */
50 raw_spin_lock_irqsave(&desc->lock, flags);
51 inprogress = irqd_irq_inprogress(&desc->irq_data);
52 raw_spin_unlock_irqrestore(&desc->lock, flags);
54 /* Oops, that failed? */
59 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
60 * @irq: interrupt number to wait for
62 * This function waits for any pending hard IRQ handlers for this
63 * interrupt to complete before returning. If you use this
64 * function while holding a resource the IRQ handler may need you
65 * will deadlock. It does not take associated threaded handlers
68 * Do not use this for shutdown scenarios where you must be sure
69 * that all parts (hardirq and threaded handler) have completed.
71 * This function may be called - with care - from IRQ context.
73 void synchronize_hardirq(unsigned int irq)
75 struct irq_desc *desc = irq_to_desc(irq);
78 __synchronize_hardirq(desc);
80 EXPORT_SYMBOL(synchronize_hardirq);
83 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
84 * @irq: interrupt number to wait for
86 * This function waits for any pending IRQ handlers for this interrupt
87 * to complete before returning. If you use this function while
88 * holding a resource the IRQ handler may need you will deadlock.
90 * This function may be called - with care - from IRQ context.
92 void synchronize_irq(unsigned int irq)
94 struct irq_desc *desc = irq_to_desc(irq);
97 __synchronize_hardirq(desc);
99 * We made sure that no hardirq handler is
100 * running. Now verify that no threaded handlers are
103 wait_event(desc->wait_for_threads,
104 !atomic_read(&desc->threads_active));
107 EXPORT_SYMBOL(synchronize_irq);
110 cpumask_var_t irq_default_affinity;
113 * irq_can_set_affinity - Check if the affinity of a given irq can be set
114 * @irq: Interrupt to check
117 int irq_can_set_affinity(unsigned int irq)
119 struct irq_desc *desc = irq_to_desc(irq);
121 if (!desc || !irqd_can_balance(&desc->irq_data) ||
122 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
129 * irq_set_thread_affinity - Notify irq threads to adjust affinity
130 * @desc: irq descriptor which has affitnity changed
132 * We just set IRQTF_AFFINITY and delegate the affinity setting
133 * to the interrupt thread itself. We can not call
134 * set_cpus_allowed_ptr() here as we hold desc->lock and this
135 * code can be called from hard interrupt context.
137 void irq_set_thread_affinity(struct irq_desc *desc)
139 struct irqaction *action = desc->action;
143 set_bit(IRQTF_AFFINITY, &action->thread_flags);
144 action = action->next;
148 #ifdef CONFIG_GENERIC_PENDING_IRQ
149 static inline bool irq_can_move_pcntxt(struct irq_data *data)
151 return irqd_can_move_in_process_context(data);
153 static inline bool irq_move_pending(struct irq_data *data)
155 return irqd_is_setaffinity_pending(data);
158 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
160 cpumask_copy(desc->pending_mask, mask);
163 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
165 cpumask_copy(mask, desc->pending_mask);
168 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
169 static inline bool irq_move_pending(struct irq_data *data) { return false; }
171 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
173 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
176 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
179 struct irq_desc *desc = irq_data_to_desc(data);
180 struct irq_chip *chip = irq_data_get_irq_chip(data);
183 ret = chip->irq_set_affinity(data, mask, false);
185 case IRQ_SET_MASK_OK:
186 cpumask_copy(data->affinity, mask);
187 case IRQ_SET_MASK_OK_NOCOPY:
188 irq_set_thread_affinity(desc);
195 int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
197 struct irq_chip *chip = irq_data_get_irq_chip(data);
198 struct irq_desc *desc = irq_data_to_desc(data);
201 if (!chip || !chip->irq_set_affinity)
204 if (irq_can_move_pcntxt(data)) {
205 ret = irq_do_set_affinity(data, mask, false);
207 irqd_set_move_pending(data);
208 irq_copy_pending(desc, mask);
211 if (desc->affinity_notify) {
212 kref_get(&desc->affinity_notify->kref);
213 schedule_work(&desc->affinity_notify->work);
215 irqd_set(data, IRQD_AFFINITY_SET);
221 * irq_set_affinity - Set the irq affinity of a given irq
222 * @irq: Interrupt to set affinity
226 int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
228 struct irq_desc *desc = irq_to_desc(irq);
235 raw_spin_lock_irqsave(&desc->lock, flags);
236 ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
237 raw_spin_unlock_irqrestore(&desc->lock, flags);
241 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
244 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
248 desc->affinity_hint = m;
249 irq_put_desc_unlock(desc, flags);
252 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
254 static void irq_affinity_notify(struct work_struct *work)
256 struct irq_affinity_notify *notify =
257 container_of(work, struct irq_affinity_notify, work);
258 struct irq_desc *desc = irq_to_desc(notify->irq);
259 cpumask_var_t cpumask;
262 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
265 raw_spin_lock_irqsave(&desc->lock, flags);
266 if (irq_move_pending(&desc->irq_data))
267 irq_get_pending(cpumask, desc);
269 cpumask_copy(cpumask, desc->irq_data.affinity);
270 raw_spin_unlock_irqrestore(&desc->lock, flags);
272 notify->notify(notify, cpumask);
274 free_cpumask_var(cpumask);
276 kref_put(¬ify->kref, notify->release);
280 * irq_set_affinity_notifier - control notification of IRQ affinity changes
281 * @irq: Interrupt for which to enable/disable notification
282 * @notify: Context for notification, or %NULL to disable
283 * notification. Function pointers must be initialised;
284 * the other fields will be initialised by this function.
286 * Must be called in process context. Notification may only be enabled
287 * after the IRQ is allocated and must be disabled before the IRQ is
288 * freed using free_irq().
291 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
293 struct irq_desc *desc = irq_to_desc(irq);
294 struct irq_affinity_notify *old_notify;
297 /* The release function is promised process context */
303 /* Complete initialisation of *notify */
306 kref_init(¬ify->kref);
307 INIT_WORK(¬ify->work, irq_affinity_notify);
310 raw_spin_lock_irqsave(&desc->lock, flags);
311 old_notify = desc->affinity_notify;
312 desc->affinity_notify = notify;
313 raw_spin_unlock_irqrestore(&desc->lock, flags);
316 kref_put(&old_notify->kref, old_notify->release);
320 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
322 #ifndef CONFIG_AUTO_IRQ_AFFINITY
324 * Generic version of the affinity autoselector.
327 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
329 struct cpumask *set = irq_default_affinity;
330 int node = desc->irq_data.node;
332 /* Excludes PER_CPU and NO_BALANCE interrupts */
333 if (!irq_can_set_affinity(irq))
337 * Preserve an userspace affinity setup, but make sure that
338 * one of the targets is online.
340 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
341 if (cpumask_intersects(desc->irq_data.affinity,
343 set = desc->irq_data.affinity;
345 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
348 cpumask_and(mask, cpu_online_mask, set);
349 if (node != NUMA_NO_NODE) {
350 const struct cpumask *nodemask = cpumask_of_node(node);
352 /* make sure at least one of the cpus in nodemask is online */
353 if (cpumask_intersects(mask, nodemask))
354 cpumask_and(mask, mask, nodemask);
356 irq_do_set_affinity(&desc->irq_data, mask, false);
361 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
363 return irq_select_affinity(irq);
368 * Called when affinity is set via /proc/irq
370 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
372 struct irq_desc *desc = irq_to_desc(irq);
376 raw_spin_lock_irqsave(&desc->lock, flags);
377 ret = setup_affinity(irq, desc, mask);
378 raw_spin_unlock_irqrestore(&desc->lock, flags);
384 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
390 void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
393 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
395 desc->istate |= IRQS_SUSPENDED;
402 static int __disable_irq_nosync(unsigned int irq)
405 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
409 __disable_irq(desc, irq, false);
410 irq_put_desc_busunlock(desc, flags);
415 * disable_irq_nosync - disable an irq without waiting
416 * @irq: Interrupt to disable
418 * Disable the selected interrupt line. Disables and Enables are
420 * Unlike disable_irq(), this function does not ensure existing
421 * instances of the IRQ handler have completed before returning.
423 * This function may be called from IRQ context.
425 void disable_irq_nosync(unsigned int irq)
427 __disable_irq_nosync(irq);
429 EXPORT_SYMBOL(disable_irq_nosync);
432 * disable_irq - disable an irq and wait for completion
433 * @irq: Interrupt to disable
435 * Disable the selected interrupt line. Enables and Disables are
437 * This function waits for any pending IRQ handlers for this interrupt
438 * to complete before returning. If you use this function while
439 * holding a resource the IRQ handler may need you will deadlock.
441 * This function may be called - with care - from IRQ context.
443 void disable_irq(unsigned int irq)
445 if (!__disable_irq_nosync(irq))
446 synchronize_irq(irq);
448 EXPORT_SYMBOL(disable_irq);
450 void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
453 if (!(desc->istate & IRQS_SUSPENDED)) {
456 if (!(desc->action->flags & IRQF_FORCE_RESUME))
458 /* Pretend that it got disabled ! */
461 desc->istate &= ~IRQS_SUSPENDED;
464 switch (desc->depth) {
467 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
470 if (desc->istate & IRQS_SUSPENDED)
472 /* Prevent probing on this irq: */
473 irq_settings_set_noprobe(desc);
475 check_irq_resend(desc, irq);
484 * enable_irq - enable handling of an irq
485 * @irq: Interrupt to enable
487 * Undoes the effect of one call to disable_irq(). If this
488 * matches the last disable, processing of interrupts on this
489 * IRQ line is re-enabled.
491 * This function may be called from IRQ context only when
492 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
494 void enable_irq(unsigned int irq)
497 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
501 if (WARN(!desc->irq_data.chip,
502 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
505 __enable_irq(desc, irq, false);
507 irq_put_desc_busunlock(desc, flags);
509 EXPORT_SYMBOL(enable_irq);
511 static int set_irq_wake_real(unsigned int irq, unsigned int on)
513 struct irq_desc *desc = irq_to_desc(irq);
516 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
519 if (desc->irq_data.chip->irq_set_wake)
520 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
526 * irq_set_irq_wake - control irq power management wakeup
527 * @irq: interrupt to control
528 * @on: enable/disable power management wakeup
530 * Enable/disable power management wakeup mode, which is
531 * disabled by default. Enables and disables must match,
532 * just as they match for non-wakeup mode support.
534 * Wakeup mode lets this IRQ wake the system from sleep
535 * states like "suspend to RAM".
537 int irq_set_irq_wake(unsigned int irq, unsigned int on)
540 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
546 /* wakeup-capable irqs can be shared between drivers that
547 * don't need to have the same sleep mode behaviors.
550 if (desc->wake_depth++ == 0) {
551 ret = set_irq_wake_real(irq, on);
553 desc->wake_depth = 0;
555 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
558 if (desc->wake_depth == 0) {
559 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
560 } else if (--desc->wake_depth == 0) {
561 ret = set_irq_wake_real(irq, on);
563 desc->wake_depth = 1;
565 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
568 irq_put_desc_busunlock(desc, flags);
571 EXPORT_SYMBOL(irq_set_irq_wake);
574 * Internal function that tells the architecture code whether a
575 * particular irq has been exclusively allocated or is available
578 int can_request_irq(unsigned int irq, unsigned long irqflags)
581 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
587 if (irq_settings_can_request(desc)) {
589 irqflags & desc->action->flags & IRQF_SHARED)
592 irq_put_desc_unlock(desc, flags);
596 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
599 struct irq_chip *chip = desc->irq_data.chip;
602 if (!chip || !chip->irq_set_type) {
604 * IRQF_TRIGGER_* but the PIC does not support multiple
607 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
608 chip ? (chip->name ? : "unknown") : "unknown");
612 flags &= IRQ_TYPE_SENSE_MASK;
614 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
615 if (!irqd_irq_masked(&desc->irq_data))
617 if (!irqd_irq_disabled(&desc->irq_data))
621 /* caller masked out all except trigger mode flags */
622 ret = chip->irq_set_type(&desc->irq_data, flags);
625 case IRQ_SET_MASK_OK:
626 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
627 irqd_set(&desc->irq_data, flags);
629 case IRQ_SET_MASK_OK_NOCOPY:
630 flags = irqd_get_trigger_type(&desc->irq_data);
631 irq_settings_set_trigger_mask(desc, flags);
632 irqd_clear(&desc->irq_data, IRQD_LEVEL);
633 irq_settings_clr_level(desc);
634 if (flags & IRQ_TYPE_LEVEL_MASK) {
635 irq_settings_set_level(desc);
636 irqd_set(&desc->irq_data, IRQD_LEVEL);
642 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
643 flags, irq, chip->irq_set_type);
650 #ifdef CONFIG_HARDIRQS_SW_RESEND
651 int irq_set_parent(int irq, int parent_irq)
654 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
659 desc->parent_irq = parent_irq;
661 irq_put_desc_unlock(desc, flags);
667 * Default primary interrupt handler for threaded interrupts. Is
668 * assigned as primary handler when request_threaded_irq is called
669 * with handler == NULL. Useful for oneshot interrupts.
671 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
673 return IRQ_WAKE_THREAD;
677 * Primary handler for nested threaded interrupts. Should never be
680 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
682 WARN(1, "Primary handler called for nested irq %d\n", irq);
686 static int irq_wait_for_interrupt(struct irqaction *action)
688 set_current_state(TASK_INTERRUPTIBLE);
690 while (!kthread_should_stop()) {
692 if (test_and_clear_bit(IRQTF_RUNTHREAD,
693 &action->thread_flags)) {
694 __set_current_state(TASK_RUNNING);
698 set_current_state(TASK_INTERRUPTIBLE);
700 __set_current_state(TASK_RUNNING);
705 * Oneshot interrupts keep the irq line masked until the threaded
706 * handler finished. unmask if the interrupt has not been disabled and
709 static void irq_finalize_oneshot(struct irq_desc *desc,
710 struct irqaction *action)
712 if (!(desc->istate & IRQS_ONESHOT))
716 raw_spin_lock_irq(&desc->lock);
719 * Implausible though it may be we need to protect us against
720 * the following scenario:
722 * The thread is faster done than the hard interrupt handler
723 * on the other CPU. If we unmask the irq line then the
724 * interrupt can come in again and masks the line, leaves due
725 * to IRQS_INPROGRESS and the irq line is masked forever.
727 * This also serializes the state of shared oneshot handlers
728 * versus "desc->threads_onehsot |= action->thread_mask;" in
729 * irq_wake_thread(). See the comment there which explains the
732 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
733 raw_spin_unlock_irq(&desc->lock);
734 chip_bus_sync_unlock(desc);
740 * Now check again, whether the thread should run. Otherwise
741 * we would clear the threads_oneshot bit of this thread which
744 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
747 desc->threads_oneshot &= ~action->thread_mask;
749 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
750 irqd_irq_masked(&desc->irq_data))
751 unmask_threaded_irq(desc);
754 raw_spin_unlock_irq(&desc->lock);
755 chip_bus_sync_unlock(desc);
760 * Check whether we need to change the affinity of the interrupt thread.
763 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
768 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
772 * In case we are out of memory we set IRQTF_AFFINITY again and
773 * try again next time
775 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
776 set_bit(IRQTF_AFFINITY, &action->thread_flags);
780 raw_spin_lock_irq(&desc->lock);
782 * This code is triggered unconditionally. Check the affinity
783 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
785 if (desc->irq_data.affinity)
786 cpumask_copy(mask, desc->irq_data.affinity);
789 raw_spin_unlock_irq(&desc->lock);
792 set_cpus_allowed_ptr(current, mask);
793 free_cpumask_var(mask);
797 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
801 * Interrupts which are not explicitely requested as threaded
802 * interrupts rely on the implicit bh/preempt disable of the hard irq
803 * context. So we need to disable bh here to avoid deadlocks and other
807 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
812 ret = action->thread_fn(action->irq, action->dev_id);
813 irq_finalize_oneshot(desc, action);
819 * Interrupts explicitly requested as threaded interrupts want to be
820 * preemtible - many of them need to sleep and wait for slow busses to
823 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
824 struct irqaction *action)
828 ret = action->thread_fn(action->irq, action->dev_id);
829 irq_finalize_oneshot(desc, action);
833 static void wake_threads_waitq(struct irq_desc *desc)
835 if (atomic_dec_and_test(&desc->threads_active))
836 wake_up(&desc->wait_for_threads);
839 static void irq_thread_dtor(struct callback_head *unused)
841 struct task_struct *tsk = current;
842 struct irq_desc *desc;
843 struct irqaction *action;
845 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
848 action = kthread_data(tsk);
850 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
851 tsk->comm, tsk->pid, action->irq);
854 desc = irq_to_desc(action->irq);
856 * If IRQTF_RUNTHREAD is set, we need to decrement
857 * desc->threads_active and wake possible waiters.
859 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
860 wake_threads_waitq(desc);
862 /* Prevent a stale desc->threads_oneshot */
863 irq_finalize_oneshot(desc, action);
867 * Interrupt handler thread
869 static int irq_thread(void *data)
871 struct callback_head on_exit_work;
872 struct irqaction *action = data;
873 struct irq_desc *desc = irq_to_desc(action->irq);
874 irqreturn_t (*handler_fn)(struct irq_desc *desc,
875 struct irqaction *action);
877 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
878 &action->thread_flags))
879 handler_fn = irq_forced_thread_fn;
881 handler_fn = irq_thread_fn;
883 init_task_work(&on_exit_work, irq_thread_dtor);
884 task_work_add(current, &on_exit_work, false);
886 irq_thread_check_affinity(desc, action);
888 while (!irq_wait_for_interrupt(action)) {
889 irqreturn_t action_ret;
891 irq_thread_check_affinity(desc, action);
893 action_ret = handler_fn(desc, action);
895 note_interrupt(action->irq, desc, action_ret);
897 wake_threads_waitq(desc);
901 * This is the regular exit path. __free_irq() is stopping the
902 * thread via kthread_stop() after calling
903 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
904 * oneshot mask bit can be set. We cannot verify that as we
905 * cannot touch the oneshot mask at this point anymore as
906 * __setup_irq() might have given out currents thread_mask
909 task_work_cancel(current, irq_thread_dtor);
914 * irq_wake_thread - wake the irq thread for the action identified by dev_id
915 * @irq: Interrupt line
916 * @dev_id: Device identity for which the thread should be woken
919 void irq_wake_thread(unsigned int irq, void *dev_id)
921 struct irq_desc *desc = irq_to_desc(irq);
922 struct irqaction *action;
925 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
928 raw_spin_lock_irqsave(&desc->lock, flags);
929 for (action = desc->action; action; action = action->next) {
930 if (action->dev_id == dev_id) {
932 __irq_wake_thread(desc, action);
936 raw_spin_unlock_irqrestore(&desc->lock, flags);
938 EXPORT_SYMBOL_GPL(irq_wake_thread);
940 static void irq_setup_forced_threading(struct irqaction *new)
942 if (!force_irqthreads)
944 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
947 new->flags |= IRQF_ONESHOT;
949 if (!new->thread_fn) {
950 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
951 new->thread_fn = new->handler;
952 new->handler = irq_default_primary_handler;
956 static int irq_request_resources(struct irq_desc *desc)
958 struct irq_data *d = &desc->irq_data;
959 struct irq_chip *c = d->chip;
961 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
964 static void irq_release_resources(struct irq_desc *desc)
966 struct irq_data *d = &desc->irq_data;
967 struct irq_chip *c = d->chip;
969 if (c->irq_release_resources)
970 c->irq_release_resources(d);
974 * Internal function to register an irqaction - typically used to
975 * allocate special interrupts that are part of the architecture.
978 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
980 struct irqaction *old, **old_ptr;
981 unsigned long flags, thread_mask = 0;
982 int ret, nested, shared = 0;
988 if (desc->irq_data.chip == &no_irq_chip)
990 if (!try_module_get(desc->owner))
994 * Check whether the interrupt nests into another interrupt
997 nested = irq_settings_is_nested_thread(desc);
999 if (!new->thread_fn) {
1004 * Replace the primary handler which was provided from
1005 * the driver for non nested interrupt handling by the
1006 * dummy function which warns when called.
1008 new->handler = irq_nested_primary_handler;
1010 if (irq_settings_can_thread(desc))
1011 irq_setup_forced_threading(new);
1015 * Create a handler thread when a thread function is supplied
1016 * and the interrupt does not nest into another interrupt
1019 if (new->thread_fn && !nested) {
1020 struct task_struct *t;
1021 static const struct sched_param param = {
1022 .sched_priority = MAX_USER_RT_PRIO/2,
1025 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1032 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1035 * We keep the reference to the task struct even if
1036 * the thread dies to avoid that the interrupt code
1037 * references an already freed task_struct.
1042 * Tell the thread to set its affinity. This is
1043 * important for shared interrupt handlers as we do
1044 * not invoke setup_affinity() for the secondary
1045 * handlers as everything is already set up. Even for
1046 * interrupts marked with IRQF_NO_BALANCE this is
1047 * correct as we want the thread to move to the cpu(s)
1048 * on which the requesting code placed the interrupt.
1050 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1053 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1059 * Drivers are often written to work w/o knowledge about the
1060 * underlying irq chip implementation, so a request for a
1061 * threaded irq without a primary hard irq context handler
1062 * requires the ONESHOT flag to be set. Some irq chips like
1063 * MSI based interrupts are per se one shot safe. Check the
1064 * chip flags, so we can avoid the unmask dance at the end of
1065 * the threaded handler for those.
1067 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1068 new->flags &= ~IRQF_ONESHOT;
1071 * The following block of code has to be executed atomically
1073 raw_spin_lock_irqsave(&desc->lock, flags);
1074 old_ptr = &desc->action;
1078 * Can't share interrupts unless both agree to and are
1079 * the same type (level, edge, polarity). So both flag
1080 * fields must have IRQF_SHARED set and the bits which
1081 * set the trigger type must match. Also all must
1084 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1085 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1086 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1089 /* All handlers must agree on per-cpuness */
1090 if ((old->flags & IRQF_PERCPU) !=
1091 (new->flags & IRQF_PERCPU))
1094 /* add new interrupt at end of irq queue */
1097 * Or all existing action->thread_mask bits,
1098 * so we can find the next zero bit for this
1101 thread_mask |= old->thread_mask;
1102 old_ptr = &old->next;
1109 * Setup the thread mask for this irqaction for ONESHOT. For
1110 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1111 * conditional in irq_wake_thread().
1113 if (new->flags & IRQF_ONESHOT) {
1115 * Unlikely to have 32 resp 64 irqs sharing one line,
1118 if (thread_mask == ~0UL) {
1123 * The thread_mask for the action is or'ed to
1124 * desc->thread_active to indicate that the
1125 * IRQF_ONESHOT thread handler has been woken, but not
1126 * yet finished. The bit is cleared when a thread
1127 * completes. When all threads of a shared interrupt
1128 * line have completed desc->threads_active becomes
1129 * zero and the interrupt line is unmasked. See
1130 * handle.c:irq_wake_thread() for further information.
1132 * If no thread is woken by primary (hard irq context)
1133 * interrupt handlers, then desc->threads_active is
1134 * also checked for zero to unmask the irq line in the
1135 * affected hard irq flow handlers
1136 * (handle_[fasteoi|level]_irq).
1138 * The new action gets the first zero bit of
1139 * thread_mask assigned. See the loop above which or's
1140 * all existing action->thread_mask bits.
1142 new->thread_mask = 1 << ffz(thread_mask);
1144 } else if (new->handler == irq_default_primary_handler &&
1145 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1147 * The interrupt was requested with handler = NULL, so
1148 * we use the default primary handler for it. But it
1149 * does not have the oneshot flag set. In combination
1150 * with level interrupts this is deadly, because the
1151 * default primary handler just wakes the thread, then
1152 * the irq lines is reenabled, but the device still
1153 * has the level irq asserted. Rinse and repeat....
1155 * While this works for edge type interrupts, we play
1156 * it safe and reject unconditionally because we can't
1157 * say for sure which type this interrupt really
1158 * has. The type flags are unreliable as the
1159 * underlying chip implementation can override them.
1161 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1168 ret = irq_request_resources(desc);
1170 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1171 new->name, irq, desc->irq_data.chip->name);
1175 init_waitqueue_head(&desc->wait_for_threads);
1177 /* Setup the type (level, edge polarity) if configured: */
1178 if (new->flags & IRQF_TRIGGER_MASK) {
1179 ret = __irq_set_trigger(desc, irq,
1180 new->flags & IRQF_TRIGGER_MASK);
1186 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1187 IRQS_ONESHOT | IRQS_WAITING);
1188 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1190 if (new->flags & IRQF_PERCPU) {
1191 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1192 irq_settings_set_per_cpu(desc);
1195 if (new->flags & IRQF_ONESHOT)
1196 desc->istate |= IRQS_ONESHOT;
1198 if (irq_settings_can_autoenable(desc))
1199 irq_startup(desc, true);
1201 /* Undo nested disables: */
1204 /* Exclude IRQ from balancing if requested */
1205 if (new->flags & IRQF_NOBALANCING) {
1206 irq_settings_set_no_balancing(desc);
1207 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1210 /* Set default affinity mask once everything is setup */
1211 setup_affinity(irq, desc, mask);
1213 } else if (new->flags & IRQF_TRIGGER_MASK) {
1214 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1215 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1218 /* hope the handler works with current trigger mode */
1219 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1226 /* Reset broken irq detection when installing new handler */
1227 desc->irq_count = 0;
1228 desc->irqs_unhandled = 0;
1231 * Check whether we disabled the irq via the spurious handler
1232 * before. Reenable it and give it another chance.
1234 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1235 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1236 __enable_irq(desc, irq, false);
1239 raw_spin_unlock_irqrestore(&desc->lock, flags);
1242 * Strictly no need to wake it up, but hung_task complains
1243 * when no hard interrupt wakes the thread up.
1246 wake_up_process(new->thread);
1248 register_irq_proc(irq, desc);
1250 register_handler_proc(irq, new);
1251 free_cpumask_var(mask);
1256 if (!(new->flags & IRQF_PROBE_SHARED)) {
1257 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1258 irq, new->flags, new->name, old->flags, old->name);
1259 #ifdef CONFIG_DEBUG_SHIRQ
1266 raw_spin_unlock_irqrestore(&desc->lock, flags);
1267 free_cpumask_var(mask);
1271 struct task_struct *t = new->thread;
1278 module_put(desc->owner);
1283 * setup_irq - setup an interrupt
1284 * @irq: Interrupt line to setup
1285 * @act: irqaction for the interrupt
1287 * Used to statically setup interrupts in the early boot process.
1289 int setup_irq(unsigned int irq, struct irqaction *act)
1292 struct irq_desc *desc = irq_to_desc(irq);
1294 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1296 chip_bus_lock(desc);
1297 retval = __setup_irq(irq, desc, act);
1298 chip_bus_sync_unlock(desc);
1302 EXPORT_SYMBOL_GPL(setup_irq);
1305 * Internal function to unregister an irqaction - used to free
1306 * regular and special interrupts that are part of the architecture.
1308 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1310 struct irq_desc *desc = irq_to_desc(irq);
1311 struct irqaction *action, **action_ptr;
1312 unsigned long flags;
1314 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1319 raw_spin_lock_irqsave(&desc->lock, flags);
1322 * There can be multiple actions per IRQ descriptor, find the right
1323 * one based on the dev_id:
1325 action_ptr = &desc->action;
1327 action = *action_ptr;
1330 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1331 raw_spin_unlock_irqrestore(&desc->lock, flags);
1336 if (action->dev_id == dev_id)
1338 action_ptr = &action->next;
1341 /* Found it - now remove it from the list of entries: */
1342 *action_ptr = action->next;
1344 /* If this was the last handler, shut down the IRQ line: */
1345 if (!desc->action) {
1347 irq_release_resources(desc);
1351 /* make sure affinity_hint is cleaned up */
1352 if (WARN_ON_ONCE(desc->affinity_hint))
1353 desc->affinity_hint = NULL;
1356 raw_spin_unlock_irqrestore(&desc->lock, flags);
1358 unregister_handler_proc(irq, action);
1360 /* Make sure it's not being used on another CPU: */
1361 synchronize_irq(irq);
1363 #ifdef CONFIG_DEBUG_SHIRQ
1365 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1366 * event to happen even now it's being freed, so let's make sure that
1367 * is so by doing an extra call to the handler ....
1369 * ( We do this after actually deregistering it, to make sure that a
1370 * 'real' IRQ doesn't run in * parallel with our fake. )
1372 if (action->flags & IRQF_SHARED) {
1373 local_irq_save(flags);
1374 action->handler(irq, dev_id);
1375 local_irq_restore(flags);
1379 if (action->thread) {
1380 kthread_stop(action->thread);
1381 put_task_struct(action->thread);
1384 module_put(desc->owner);
1389 * remove_irq - free an interrupt
1390 * @irq: Interrupt line to free
1391 * @act: irqaction for the interrupt
1393 * Used to remove interrupts statically setup by the early boot process.
1395 void remove_irq(unsigned int irq, struct irqaction *act)
1397 struct irq_desc *desc = irq_to_desc(irq);
1399 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1400 __free_irq(irq, act->dev_id);
1402 EXPORT_SYMBOL_GPL(remove_irq);
1405 * free_irq - free an interrupt allocated with request_irq
1406 * @irq: Interrupt line to free
1407 * @dev_id: Device identity to free
1409 * Remove an interrupt handler. The handler is removed and if the
1410 * interrupt line is no longer in use by any driver it is disabled.
1411 * On a shared IRQ the caller must ensure the interrupt is disabled
1412 * on the card it drives before calling this function. The function
1413 * does not return until any executing interrupts for this IRQ
1416 * This function must not be called from interrupt context.
1418 void free_irq(unsigned int irq, void *dev_id)
1420 struct irq_desc *desc = irq_to_desc(irq);
1422 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1426 if (WARN_ON(desc->affinity_notify))
1427 desc->affinity_notify = NULL;
1430 chip_bus_lock(desc);
1431 kfree(__free_irq(irq, dev_id));
1432 chip_bus_sync_unlock(desc);
1434 EXPORT_SYMBOL(free_irq);
1437 * request_threaded_irq - allocate an interrupt line
1438 * @irq: Interrupt line to allocate
1439 * @handler: Function to be called when the IRQ occurs.
1440 * Primary handler for threaded interrupts
1441 * If NULL and thread_fn != NULL the default
1442 * primary handler is installed
1443 * @thread_fn: Function called from the irq handler thread
1444 * If NULL, no irq thread is created
1445 * @irqflags: Interrupt type flags
1446 * @devname: An ascii name for the claiming device
1447 * @dev_id: A cookie passed back to the handler function
1449 * This call allocates interrupt resources and enables the
1450 * interrupt line and IRQ handling. From the point this
1451 * call is made your handler function may be invoked. Since
1452 * your handler function must clear any interrupt the board
1453 * raises, you must take care both to initialise your hardware
1454 * and to set up the interrupt handler in the right order.
1456 * If you want to set up a threaded irq handler for your device
1457 * then you need to supply @handler and @thread_fn. @handler is
1458 * still called in hard interrupt context and has to check
1459 * whether the interrupt originates from the device. If yes it
1460 * needs to disable the interrupt on the device and return
1461 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1462 * @thread_fn. This split handler design is necessary to support
1463 * shared interrupts.
1465 * Dev_id must be globally unique. Normally the address of the
1466 * device data structure is used as the cookie. Since the handler
1467 * receives this value it makes sense to use it.
1469 * If your interrupt is shared you must pass a non NULL dev_id
1470 * as this is required when freeing the interrupt.
1474 * IRQF_SHARED Interrupt is shared
1475 * IRQF_TRIGGER_* Specify active edge(s) or level
1478 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1479 irq_handler_t thread_fn, unsigned long irqflags,
1480 const char *devname, void *dev_id)
1482 struct irqaction *action;
1483 struct irq_desc *desc;
1487 * Sanity-check: shared interrupts must pass in a real dev-ID,
1488 * otherwise we'll have trouble later trying to figure out
1489 * which interrupt is which (messes up the interrupt freeing
1492 if ((irqflags & IRQF_SHARED) && !dev_id)
1495 desc = irq_to_desc(irq);
1499 if (!irq_settings_can_request(desc) ||
1500 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1506 handler = irq_default_primary_handler;
1509 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1513 action->handler = handler;
1514 action->thread_fn = thread_fn;
1515 action->flags = irqflags;
1516 action->name = devname;
1517 action->dev_id = dev_id;
1519 chip_bus_lock(desc);
1520 retval = __setup_irq(irq, desc, action);
1521 chip_bus_sync_unlock(desc);
1526 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1527 if (!retval && (irqflags & IRQF_SHARED)) {
1529 * It's a shared IRQ -- the driver ought to be prepared for it
1530 * to happen immediately, so let's make sure....
1531 * We disable the irq to make sure that a 'real' IRQ doesn't
1532 * run in parallel with our fake.
1534 unsigned long flags;
1537 local_irq_save(flags);
1539 handler(irq, dev_id);
1541 local_irq_restore(flags);
1547 EXPORT_SYMBOL(request_threaded_irq);
1550 * request_any_context_irq - allocate an interrupt line
1551 * @irq: Interrupt line to allocate
1552 * @handler: Function to be called when the IRQ occurs.
1553 * Threaded handler for threaded interrupts.
1554 * @flags: Interrupt type flags
1555 * @name: An ascii name for the claiming device
1556 * @dev_id: A cookie passed back to the handler function
1558 * This call allocates interrupt resources and enables the
1559 * interrupt line and IRQ handling. It selects either a
1560 * hardirq or threaded handling method depending on the
1563 * On failure, it returns a negative value. On success,
1564 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1566 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1567 unsigned long flags, const char *name, void *dev_id)
1569 struct irq_desc *desc = irq_to_desc(irq);
1575 if (irq_settings_is_nested_thread(desc)) {
1576 ret = request_threaded_irq(irq, NULL, handler,
1577 flags, name, dev_id);
1578 return !ret ? IRQC_IS_NESTED : ret;
1581 ret = request_irq(irq, handler, flags, name, dev_id);
1582 return !ret ? IRQC_IS_HARDIRQ : ret;
1584 EXPORT_SYMBOL_GPL(request_any_context_irq);
1586 void enable_percpu_irq(unsigned int irq, unsigned int type)
1588 unsigned int cpu = smp_processor_id();
1589 unsigned long flags;
1590 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1595 type &= IRQ_TYPE_SENSE_MASK;
1596 if (type != IRQ_TYPE_NONE) {
1599 ret = __irq_set_trigger(desc, irq, type);
1602 WARN(1, "failed to set type for IRQ%d\n", irq);
1607 irq_percpu_enable(desc, cpu);
1609 irq_put_desc_unlock(desc, flags);
1611 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1613 void disable_percpu_irq(unsigned int irq)
1615 unsigned int cpu = smp_processor_id();
1616 unsigned long flags;
1617 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1622 irq_percpu_disable(desc, cpu);
1623 irq_put_desc_unlock(desc, flags);
1625 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1628 * Internal function to unregister a percpu irqaction.
1630 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1632 struct irq_desc *desc = irq_to_desc(irq);
1633 struct irqaction *action;
1634 unsigned long flags;
1636 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1641 raw_spin_lock_irqsave(&desc->lock, flags);
1643 action = desc->action;
1644 if (!action || action->percpu_dev_id != dev_id) {
1645 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1649 if (!cpumask_empty(desc->percpu_enabled)) {
1650 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1651 irq, cpumask_first(desc->percpu_enabled));
1655 /* Found it - now remove it from the list of entries: */
1656 desc->action = NULL;
1658 raw_spin_unlock_irqrestore(&desc->lock, flags);
1660 unregister_handler_proc(irq, action);
1662 module_put(desc->owner);
1666 raw_spin_unlock_irqrestore(&desc->lock, flags);
1671 * remove_percpu_irq - free a per-cpu interrupt
1672 * @irq: Interrupt line to free
1673 * @act: irqaction for the interrupt
1675 * Used to remove interrupts statically setup by the early boot process.
1677 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1679 struct irq_desc *desc = irq_to_desc(irq);
1681 if (desc && irq_settings_is_per_cpu_devid(desc))
1682 __free_percpu_irq(irq, act->percpu_dev_id);
1686 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1687 * @irq: Interrupt line to free
1688 * @dev_id: Device identity to free
1690 * Remove a percpu interrupt handler. The handler is removed, but
1691 * the interrupt line is not disabled. This must be done on each
1692 * CPU before calling this function. The function does not return
1693 * until any executing interrupts for this IRQ have completed.
1695 * This function must not be called from interrupt context.
1697 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1699 struct irq_desc *desc = irq_to_desc(irq);
1701 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1704 chip_bus_lock(desc);
1705 kfree(__free_percpu_irq(irq, dev_id));
1706 chip_bus_sync_unlock(desc);
1710 * setup_percpu_irq - setup a per-cpu interrupt
1711 * @irq: Interrupt line to setup
1712 * @act: irqaction for the interrupt
1714 * Used to statically setup per-cpu interrupts in the early boot process.
1716 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1718 struct irq_desc *desc = irq_to_desc(irq);
1721 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1723 chip_bus_lock(desc);
1724 retval = __setup_irq(irq, desc, act);
1725 chip_bus_sync_unlock(desc);
1731 * request_percpu_irq - allocate a percpu interrupt line
1732 * @irq: Interrupt line to allocate
1733 * @handler: Function to be called when the IRQ occurs.
1734 * @devname: An ascii name for the claiming device
1735 * @dev_id: A percpu cookie passed back to the handler function
1737 * This call allocates interrupt resources, but doesn't
1738 * automatically enable the interrupt. It has to be done on each
1739 * CPU using enable_percpu_irq().
1741 * Dev_id must be globally unique. It is a per-cpu variable, and
1742 * the handler gets called with the interrupted CPU's instance of
1745 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1746 const char *devname, void __percpu *dev_id)
1748 struct irqaction *action;
1749 struct irq_desc *desc;
1755 desc = irq_to_desc(irq);
1756 if (!desc || !irq_settings_can_request(desc) ||
1757 !irq_settings_is_per_cpu_devid(desc))
1760 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1764 action->handler = handler;
1765 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1766 action->name = devname;
1767 action->percpu_dev_id = dev_id;
1769 chip_bus_lock(desc);
1770 retval = __setup_irq(irq, desc, action);
1771 chip_bus_sync_unlock(desc);