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/task_work.h>
21 #include "internals.h"
23 #ifdef CONFIG_IRQ_FORCED_THREADING
24 __read_mostly
bool force_irqthreads
;
26 static int __init
setup_forced_irqthreads(char *arg
)
28 force_irqthreads
= true;
31 early_param("threadirqs", setup_forced_irqthreads
);
35 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
36 * @irq: interrupt number to wait for
38 * This function waits for any pending IRQ handlers for this interrupt
39 * to complete before returning. If you use this function while
40 * holding a resource the IRQ handler may need you will deadlock.
42 * This function may be called - with care - from IRQ context.
44 void synchronize_irq(unsigned int irq
)
46 struct irq_desc
*desc
= irq_to_desc(irq
);
56 * Wait until we're out of the critical section. This might
57 * give the wrong answer due to the lack of memory barriers.
59 while (irqd_irq_inprogress(&desc
->irq_data
))
62 /* Ok, that indicated we're done: double-check carefully. */
63 raw_spin_lock_irqsave(&desc
->lock
, flags
);
64 inprogress
= irqd_irq_inprogress(&desc
->irq_data
);
65 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
67 /* Oops, that failed? */
71 * We made sure that no hardirq handler is running. Now verify
72 * that no threaded handlers are active.
74 wait_event(desc
->wait_for_threads
, !atomic_read(&desc
->threads_active
));
76 EXPORT_SYMBOL(synchronize_irq
);
79 cpumask_var_t irq_default_affinity
;
82 * irq_can_set_affinity - Check if the affinity of a given irq can be set
83 * @irq: Interrupt to check
86 int irq_can_set_affinity(unsigned int irq
)
88 struct irq_desc
*desc
= irq_to_desc(irq
);
90 if (!desc
|| !irqd_can_balance(&desc
->irq_data
) ||
91 !desc
->irq_data
.chip
|| !desc
->irq_data
.chip
->irq_set_affinity
)
98 * irq_set_thread_affinity - Notify irq threads to adjust affinity
99 * @desc: irq descriptor which has affitnity changed
101 * We just set IRQTF_AFFINITY and delegate the affinity setting
102 * to the interrupt thread itself. We can not call
103 * set_cpus_allowed_ptr() here as we hold desc->lock and this
104 * code can be called from hard interrupt context.
106 void irq_set_thread_affinity(struct irq_desc
*desc
)
108 struct irqaction
*action
= desc
->action
;
112 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
113 action
= action
->next
;
117 #ifdef CONFIG_GENERIC_PENDING_IRQ
118 static inline bool irq_can_move_pcntxt(struct irq_data
*data
)
120 return irqd_can_move_in_process_context(data
);
122 static inline bool irq_move_pending(struct irq_data
*data
)
124 return irqd_is_setaffinity_pending(data
);
127 irq_copy_pending(struct irq_desc
*desc
, const struct cpumask
*mask
)
129 cpumask_copy(desc
->pending_mask
, mask
);
132 irq_get_pending(struct cpumask
*mask
, struct irq_desc
*desc
)
134 cpumask_copy(mask
, desc
->pending_mask
);
137 static inline bool irq_can_move_pcntxt(struct irq_data
*data
) { return true; }
138 static inline bool irq_move_pending(struct irq_data
*data
) { return false; }
140 irq_copy_pending(struct irq_desc
*desc
, const struct cpumask
*mask
) { }
142 irq_get_pending(struct cpumask
*mask
, struct irq_desc
*desc
) { }
145 int __irq_set_affinity_locked(struct irq_data
*data
, const struct cpumask
*mask
)
147 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
148 struct irq_desc
*desc
= irq_data_to_desc(data
);
151 if (!chip
|| !chip
->irq_set_affinity
)
154 if (irq_can_move_pcntxt(data
)) {
155 ret
= chip
->irq_set_affinity(data
, mask
, false);
157 case IRQ_SET_MASK_OK
:
158 cpumask_copy(data
->affinity
, mask
);
159 case IRQ_SET_MASK_OK_NOCOPY
:
160 irq_set_thread_affinity(desc
);
164 irqd_set_move_pending(data
);
165 irq_copy_pending(desc
, mask
);
168 if (desc
->affinity_notify
) {
169 kref_get(&desc
->affinity_notify
->kref
);
170 schedule_work(&desc
->affinity_notify
->work
);
172 irqd_set(data
, IRQD_AFFINITY_SET
);
178 * irq_set_affinity - Set the irq affinity of a given irq
179 * @irq: Interrupt to set affinity
183 int irq_set_affinity(unsigned int irq
, const struct cpumask
*mask
)
185 struct irq_desc
*desc
= irq_to_desc(irq
);
192 raw_spin_lock_irqsave(&desc
->lock
, flags
);
193 ret
= __irq_set_affinity_locked(irq_desc_get_irq_data(desc
), mask
);
194 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
198 int irq_set_affinity_hint(unsigned int irq
, const struct cpumask
*m
)
201 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
205 desc
->affinity_hint
= m
;
206 irq_put_desc_unlock(desc
, flags
);
209 EXPORT_SYMBOL_GPL(irq_set_affinity_hint
);
211 static void irq_affinity_notify(struct work_struct
*work
)
213 struct irq_affinity_notify
*notify
=
214 container_of(work
, struct irq_affinity_notify
, work
);
215 struct irq_desc
*desc
= irq_to_desc(notify
->irq
);
216 cpumask_var_t cpumask
;
219 if (!desc
|| !alloc_cpumask_var(&cpumask
, GFP_KERNEL
))
222 raw_spin_lock_irqsave(&desc
->lock
, flags
);
223 if (irq_move_pending(&desc
->irq_data
))
224 irq_get_pending(cpumask
, desc
);
226 cpumask_copy(cpumask
, desc
->irq_data
.affinity
);
227 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
229 notify
->notify(notify
, cpumask
);
231 free_cpumask_var(cpumask
);
233 kref_put(¬ify
->kref
, notify
->release
);
237 * irq_set_affinity_notifier - control notification of IRQ affinity changes
238 * @irq: Interrupt for which to enable/disable notification
239 * @notify: Context for notification, or %NULL to disable
240 * notification. Function pointers must be initialised;
241 * the other fields will be initialised by this function.
243 * Must be called in process context. Notification may only be enabled
244 * after the IRQ is allocated and must be disabled before the IRQ is
245 * freed using free_irq().
248 irq_set_affinity_notifier(unsigned int irq
, struct irq_affinity_notify
*notify
)
250 struct irq_desc
*desc
= irq_to_desc(irq
);
251 struct irq_affinity_notify
*old_notify
;
254 /* The release function is promised process context */
260 /* Complete initialisation of *notify */
263 kref_init(¬ify
->kref
);
264 INIT_WORK(¬ify
->work
, irq_affinity_notify
);
267 raw_spin_lock_irqsave(&desc
->lock
, flags
);
268 old_notify
= desc
->affinity_notify
;
269 desc
->affinity_notify
= notify
;
270 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
273 kref_put(&old_notify
->kref
, old_notify
->release
);
277 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier
);
279 #ifndef CONFIG_AUTO_IRQ_AFFINITY
281 * Generic version of the affinity autoselector.
284 setup_affinity(unsigned int irq
, struct irq_desc
*desc
, struct cpumask
*mask
)
286 struct irq_chip
*chip
= irq_desc_get_chip(desc
);
287 struct cpumask
*set
= irq_default_affinity
;
288 int ret
, node
= desc
->irq_data
.node
;
290 /* Excludes PER_CPU and NO_BALANCE interrupts */
291 if (!irq_can_set_affinity(irq
))
295 * Preserve an userspace affinity setup, but make sure that
296 * one of the targets is online.
298 if (irqd_has_set(&desc
->irq_data
, IRQD_AFFINITY_SET
)) {
299 if (cpumask_intersects(desc
->irq_data
.affinity
,
301 set
= desc
->irq_data
.affinity
;
303 irqd_clear(&desc
->irq_data
, IRQD_AFFINITY_SET
);
306 cpumask_and(mask
, cpu_online_mask
, set
);
307 if (node
!= NUMA_NO_NODE
) {
308 const struct cpumask
*nodemask
= cpumask_of_node(node
);
310 /* make sure at least one of the cpus in nodemask is online */
311 if (cpumask_intersects(mask
, nodemask
))
312 cpumask_and(mask
, mask
, nodemask
);
314 ret
= chip
->irq_set_affinity(&desc
->irq_data
, mask
, false);
316 case IRQ_SET_MASK_OK
:
317 cpumask_copy(desc
->irq_data
.affinity
, mask
);
318 case IRQ_SET_MASK_OK_NOCOPY
:
319 irq_set_thread_affinity(desc
);
325 setup_affinity(unsigned int irq
, struct irq_desc
*d
, struct cpumask
*mask
)
327 return irq_select_affinity(irq
);
332 * Called when affinity is set via /proc/irq
334 int irq_select_affinity_usr(unsigned int irq
, struct cpumask
*mask
)
336 struct irq_desc
*desc
= irq_to_desc(irq
);
340 raw_spin_lock_irqsave(&desc
->lock
, flags
);
341 ret
= setup_affinity(irq
, desc
, mask
);
342 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
348 setup_affinity(unsigned int irq
, struct irq_desc
*desc
, struct cpumask
*mask
)
354 void __disable_irq(struct irq_desc
*desc
, unsigned int irq
, bool suspend
)
357 if (!desc
->action
|| (desc
->action
->flags
& IRQF_NO_SUSPEND
))
359 desc
->istate
|= IRQS_SUSPENDED
;
366 static int __disable_irq_nosync(unsigned int irq
)
369 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
373 __disable_irq(desc
, irq
, false);
374 irq_put_desc_busunlock(desc
, flags
);
379 * disable_irq_nosync - disable an irq without waiting
380 * @irq: Interrupt to disable
382 * Disable the selected interrupt line. Disables and Enables are
384 * Unlike disable_irq(), this function does not ensure existing
385 * instances of the IRQ handler have completed before returning.
387 * This function may be called from IRQ context.
389 void disable_irq_nosync(unsigned int irq
)
391 __disable_irq_nosync(irq
);
393 EXPORT_SYMBOL(disable_irq_nosync
);
396 * disable_irq - disable an irq and wait for completion
397 * @irq: Interrupt to disable
399 * Disable the selected interrupt line. Enables and Disables are
401 * This function waits for any pending IRQ handlers for this interrupt
402 * to complete before returning. If you use this function while
403 * holding a resource the IRQ handler may need you will deadlock.
405 * This function may be called - with care - from IRQ context.
407 void disable_irq(unsigned int irq
)
409 if (!__disable_irq_nosync(irq
))
410 synchronize_irq(irq
);
412 EXPORT_SYMBOL(disable_irq
);
414 void __enable_irq(struct irq_desc
*desc
, unsigned int irq
, bool resume
)
417 if (!(desc
->istate
& IRQS_SUSPENDED
)) {
420 if (!(desc
->action
->flags
& IRQF_FORCE_RESUME
))
422 /* Pretend that it got disabled ! */
425 desc
->istate
&= ~IRQS_SUSPENDED
;
428 switch (desc
->depth
) {
431 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n", irq
);
434 if (desc
->istate
& IRQS_SUSPENDED
)
436 /* Prevent probing on this irq: */
437 irq_settings_set_noprobe(desc
);
439 check_irq_resend(desc
, irq
);
448 * enable_irq - enable handling of an irq
449 * @irq: Interrupt to enable
451 * Undoes the effect of one call to disable_irq(). If this
452 * matches the last disable, processing of interrupts on this
453 * IRQ line is re-enabled.
455 * This function may be called from IRQ context only when
456 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
458 void enable_irq(unsigned int irq
)
461 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
465 if (WARN(!desc
->irq_data
.chip
,
466 KERN_ERR
"enable_irq before setup/request_irq: irq %u\n", irq
))
469 __enable_irq(desc
, irq
, false);
471 irq_put_desc_busunlock(desc
, flags
);
473 EXPORT_SYMBOL(enable_irq
);
475 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
477 struct irq_desc
*desc
= irq_to_desc(irq
);
480 if (irq_desc_get_chip(desc
)->flags
& IRQCHIP_SKIP_SET_WAKE
)
483 if (desc
->irq_data
.chip
->irq_set_wake
)
484 ret
= desc
->irq_data
.chip
->irq_set_wake(&desc
->irq_data
, on
);
490 * irq_set_irq_wake - control irq power management wakeup
491 * @irq: interrupt to control
492 * @on: enable/disable power management wakeup
494 * Enable/disable power management wakeup mode, which is
495 * disabled by default. Enables and disables must match,
496 * just as they match for non-wakeup mode support.
498 * Wakeup mode lets this IRQ wake the system from sleep
499 * states like "suspend to RAM".
501 int irq_set_irq_wake(unsigned int irq
, unsigned int on
)
504 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
510 /* wakeup-capable irqs can be shared between drivers that
511 * don't need to have the same sleep mode behaviors.
514 if (desc
->wake_depth
++ == 0) {
515 ret
= set_irq_wake_real(irq
, on
);
517 desc
->wake_depth
= 0;
519 irqd_set(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
522 if (desc
->wake_depth
== 0) {
523 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
524 } else if (--desc
->wake_depth
== 0) {
525 ret
= set_irq_wake_real(irq
, on
);
527 desc
->wake_depth
= 1;
529 irqd_clear(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
532 irq_put_desc_busunlock(desc
, flags
);
535 EXPORT_SYMBOL(irq_set_irq_wake
);
538 * Internal function that tells the architecture code whether a
539 * particular irq has been exclusively allocated or is available
542 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
545 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
551 if (irq_settings_can_request(desc
)) {
553 if (irqflags
& desc
->action
->flags
& IRQF_SHARED
)
556 irq_put_desc_unlock(desc
, flags
);
560 int __irq_set_trigger(struct irq_desc
*desc
, unsigned int irq
,
563 struct irq_chip
*chip
= desc
->irq_data
.chip
;
566 if (!chip
|| !chip
->irq_set_type
) {
568 * IRQF_TRIGGER_* but the PIC does not support multiple
571 pr_debug("No set_type function for IRQ %d (%s)\n", irq
,
572 chip
? (chip
->name
? : "unknown") : "unknown");
576 flags
&= IRQ_TYPE_SENSE_MASK
;
578 if (chip
->flags
& IRQCHIP_SET_TYPE_MASKED
) {
579 if (!irqd_irq_masked(&desc
->irq_data
))
581 if (!irqd_irq_disabled(&desc
->irq_data
))
585 /* caller masked out all except trigger mode flags */
586 ret
= chip
->irq_set_type(&desc
->irq_data
, flags
);
589 case IRQ_SET_MASK_OK
:
590 irqd_clear(&desc
->irq_data
, IRQD_TRIGGER_MASK
);
591 irqd_set(&desc
->irq_data
, flags
);
593 case IRQ_SET_MASK_OK_NOCOPY
:
594 flags
= irqd_get_trigger_type(&desc
->irq_data
);
595 irq_settings_set_trigger_mask(desc
, flags
);
596 irqd_clear(&desc
->irq_data
, IRQD_LEVEL
);
597 irq_settings_clr_level(desc
);
598 if (flags
& IRQ_TYPE_LEVEL_MASK
) {
599 irq_settings_set_level(desc
);
600 irqd_set(&desc
->irq_data
, IRQD_LEVEL
);
606 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
607 flags
, irq
, chip
->irq_set_type
);
615 * Default primary interrupt handler for threaded interrupts. Is
616 * assigned as primary handler when request_threaded_irq is called
617 * with handler == NULL. Useful for oneshot interrupts.
619 static irqreturn_t
irq_default_primary_handler(int irq
, void *dev_id
)
621 return IRQ_WAKE_THREAD
;
625 * Primary handler for nested threaded interrupts. Should never be
628 static irqreturn_t
irq_nested_primary_handler(int irq
, void *dev_id
)
630 WARN(1, "Primary handler called for nested irq %d\n", irq
);
634 static int irq_wait_for_interrupt(struct irqaction
*action
)
636 set_current_state(TASK_INTERRUPTIBLE
);
638 while (!kthread_should_stop()) {
640 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
641 &action
->thread_flags
)) {
642 __set_current_state(TASK_RUNNING
);
646 set_current_state(TASK_INTERRUPTIBLE
);
648 __set_current_state(TASK_RUNNING
);
653 * Oneshot interrupts keep the irq line masked until the threaded
654 * handler finished. unmask if the interrupt has not been disabled and
657 static void irq_finalize_oneshot(struct irq_desc
*desc
,
658 struct irqaction
*action
)
660 if (!(desc
->istate
& IRQS_ONESHOT
))
664 raw_spin_lock_irq(&desc
->lock
);
667 * Implausible though it may be we need to protect us against
668 * the following scenario:
670 * The thread is faster done than the hard interrupt handler
671 * on the other CPU. If we unmask the irq line then the
672 * interrupt can come in again and masks the line, leaves due
673 * to IRQS_INPROGRESS and the irq line is masked forever.
675 * This also serializes the state of shared oneshot handlers
676 * versus "desc->threads_onehsot |= action->thread_mask;" in
677 * irq_wake_thread(). See the comment there which explains the
680 if (unlikely(irqd_irq_inprogress(&desc
->irq_data
))) {
681 raw_spin_unlock_irq(&desc
->lock
);
682 chip_bus_sync_unlock(desc
);
688 * Now check again, whether the thread should run. Otherwise
689 * we would clear the threads_oneshot bit of this thread which
692 if (test_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
695 desc
->threads_oneshot
&= ~action
->thread_mask
;
697 if (!desc
->threads_oneshot
&& !irqd_irq_disabled(&desc
->irq_data
) &&
698 irqd_irq_masked(&desc
->irq_data
))
702 raw_spin_unlock_irq(&desc
->lock
);
703 chip_bus_sync_unlock(desc
);
708 * Check whether we need to chasnge the affinity of the interrupt thread.
711 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
)
715 if (!test_and_clear_bit(IRQTF_AFFINITY
, &action
->thread_flags
))
719 * In case we are out of memory we set IRQTF_AFFINITY again and
720 * try again next time
722 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
723 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
727 raw_spin_lock_irq(&desc
->lock
);
728 cpumask_copy(mask
, desc
->irq_data
.affinity
);
729 raw_spin_unlock_irq(&desc
->lock
);
731 set_cpus_allowed_ptr(current
, mask
);
732 free_cpumask_var(mask
);
736 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
) { }
740 * Interrupts which are not explicitely requested as threaded
741 * interrupts rely on the implicit bh/preempt disable of the hard irq
742 * context. So we need to disable bh here to avoid deadlocks and other
746 irq_forced_thread_fn(struct irq_desc
*desc
, struct irqaction
*action
)
751 ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
752 irq_finalize_oneshot(desc
, action
);
758 * Interrupts explicitely requested as threaded interupts want to be
759 * preemtible - many of them need to sleep and wait for slow busses to
762 static irqreturn_t
irq_thread_fn(struct irq_desc
*desc
,
763 struct irqaction
*action
)
767 ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
768 irq_finalize_oneshot(desc
, action
);
772 static void wake_threads_waitq(struct irq_desc
*desc
)
774 if (atomic_dec_and_test(&desc
->threads_active
) &&
775 waitqueue_active(&desc
->wait_for_threads
))
776 wake_up(&desc
->wait_for_threads
);
779 static void irq_thread_dtor(struct task_work
*unused
)
781 struct task_struct
*tsk
= current
;
782 struct irq_desc
*desc
;
783 struct irqaction
*action
;
785 if (WARN_ON_ONCE(!(current
->flags
& PF_EXITING
)))
788 action
= kthread_data(tsk
);
790 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
791 tsk
->comm
? tsk
->comm
: "", tsk
->pid
, action
->irq
);
794 desc
= irq_to_desc(action
->irq
);
796 * If IRQTF_RUNTHREAD is set, we need to decrement
797 * desc->threads_active and wake possible waiters.
799 if (test_and_clear_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
800 wake_threads_waitq(desc
);
802 /* Prevent a stale desc->threads_oneshot */
803 irq_finalize_oneshot(desc
, action
);
807 * Interrupt handler thread
809 static int irq_thread(void *data
)
811 struct task_work on_exit_work
;
812 static const struct sched_param param
= {
813 .sched_priority
= MAX_USER_RT_PRIO
/2,
815 struct irqaction
*action
= data
;
816 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
817 irqreturn_t (*handler_fn
)(struct irq_desc
*desc
,
818 struct irqaction
*action
);
820 if (force_irqthreads
&& test_bit(IRQTF_FORCED_THREAD
,
821 &action
->thread_flags
))
822 handler_fn
= irq_forced_thread_fn
;
824 handler_fn
= irq_thread_fn
;
826 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
828 init_task_work(&on_exit_work
, irq_thread_dtor
, NULL
);
829 task_work_add(current
, &on_exit_work
, false);
831 while (!irq_wait_for_interrupt(action
)) {
832 irqreturn_t action_ret
;
834 irq_thread_check_affinity(desc
, action
);
836 action_ret
= handler_fn(desc
, action
);
838 note_interrupt(action
->irq
, desc
, action_ret
);
840 wake_threads_waitq(desc
);
844 * This is the regular exit path. __free_irq() is stopping the
845 * thread via kthread_stop() after calling
846 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
847 * oneshot mask bit can be set. We cannot verify that as we
848 * cannot touch the oneshot mask at this point anymore as
849 * __setup_irq() might have given out currents thread_mask
852 task_work_cancel(current
, irq_thread_dtor
);
856 static void irq_setup_forced_threading(struct irqaction
*new)
858 if (!force_irqthreads
)
860 if (new->flags
& (IRQF_NO_THREAD
| IRQF_PERCPU
| IRQF_ONESHOT
))
863 new->flags
|= IRQF_ONESHOT
;
865 if (!new->thread_fn
) {
866 set_bit(IRQTF_FORCED_THREAD
, &new->thread_flags
);
867 new->thread_fn
= new->handler
;
868 new->handler
= irq_default_primary_handler
;
873 * Internal function to register an irqaction - typically used to
874 * allocate special interrupts that are part of the architecture.
877 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
879 struct irqaction
*old
, **old_ptr
;
880 unsigned long flags
, thread_mask
= 0;
881 int ret
, nested
, shared
= 0;
887 if (desc
->irq_data
.chip
== &no_irq_chip
)
889 if (!try_module_get(desc
->owner
))
892 * Some drivers like serial.c use request_irq() heavily,
893 * so we have to be careful not to interfere with a
896 if (new->flags
& IRQF_SAMPLE_RANDOM
) {
898 * This function might sleep, we want to call it first,
899 * outside of the atomic block.
900 * Yes, this might clear the entropy pool if the wrong
901 * driver is attempted to be loaded, without actually
902 * installing a new handler, but is this really a problem,
903 * only the sysadmin is able to do this.
905 rand_initialize_irq(irq
);
909 * Check whether the interrupt nests into another interrupt
912 nested
= irq_settings_is_nested_thread(desc
);
914 if (!new->thread_fn
) {
919 * Replace the primary handler which was provided from
920 * the driver for non nested interrupt handling by the
921 * dummy function which warns when called.
923 new->handler
= irq_nested_primary_handler
;
925 if (irq_settings_can_thread(desc
))
926 irq_setup_forced_threading(new);
930 * Create a handler thread when a thread function is supplied
931 * and the interrupt does not nest into another interrupt
934 if (new->thread_fn
&& !nested
) {
935 struct task_struct
*t
;
937 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
944 * We keep the reference to the task struct even if
945 * the thread dies to avoid that the interrupt code
946 * references an already freed task_struct.
952 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
958 * The following block of code has to be executed atomically
960 raw_spin_lock_irqsave(&desc
->lock
, flags
);
961 old_ptr
= &desc
->action
;
965 * Can't share interrupts unless both agree to and are
966 * the same type (level, edge, polarity). So both flag
967 * fields must have IRQF_SHARED set and the bits which
968 * set the trigger type must match. Also all must
971 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
972 ((old
->flags
^ new->flags
) & IRQF_TRIGGER_MASK
) ||
973 ((old
->flags
^ new->flags
) & IRQF_ONESHOT
))
976 /* All handlers must agree on per-cpuness */
977 if ((old
->flags
& IRQF_PERCPU
) !=
978 (new->flags
& IRQF_PERCPU
))
981 /* add new interrupt at end of irq queue */
984 * Or all existing action->thread_mask bits,
985 * so we can find the next zero bit for this
988 thread_mask
|= old
->thread_mask
;
989 old_ptr
= &old
->next
;
996 * Setup the thread mask for this irqaction for ONESHOT. For
997 * !ONESHOT irqs the thread mask is 0 so we can avoid a
998 * conditional in irq_wake_thread().
1000 if (new->flags
& IRQF_ONESHOT
) {
1002 * Unlikely to have 32 resp 64 irqs sharing one line,
1005 if (thread_mask
== ~0UL) {
1010 * The thread_mask for the action is or'ed to
1011 * desc->thread_active to indicate that the
1012 * IRQF_ONESHOT thread handler has been woken, but not
1013 * yet finished. The bit is cleared when a thread
1014 * completes. When all threads of a shared interrupt
1015 * line have completed desc->threads_active becomes
1016 * zero and the interrupt line is unmasked. See
1017 * handle.c:irq_wake_thread() for further information.
1019 * If no thread is woken by primary (hard irq context)
1020 * interrupt handlers, then desc->threads_active is
1021 * also checked for zero to unmask the irq line in the
1022 * affected hard irq flow handlers
1023 * (handle_[fasteoi|level]_irq).
1025 * The new action gets the first zero bit of
1026 * thread_mask assigned. See the loop above which or's
1027 * all existing action->thread_mask bits.
1029 new->thread_mask
= 1 << ffz(thread_mask
);
1031 } else if (new->handler
== irq_default_primary_handler
) {
1033 * The interrupt was requested with handler = NULL, so
1034 * we use the default primary handler for it. But it
1035 * does not have the oneshot flag set. In combination
1036 * with level interrupts this is deadly, because the
1037 * default primary handler just wakes the thread, then
1038 * the irq lines is reenabled, but the device still
1039 * has the level irq asserted. Rinse and repeat....
1041 * While this works for edge type interrupts, we play
1042 * it safe and reject unconditionally because we can't
1043 * say for sure which type this interrupt really
1044 * has. The type flags are unreliable as the
1045 * underlying chip implementation can override them.
1047 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1054 init_waitqueue_head(&desc
->wait_for_threads
);
1056 /* Setup the type (level, edge polarity) if configured: */
1057 if (new->flags
& IRQF_TRIGGER_MASK
) {
1058 ret
= __irq_set_trigger(desc
, irq
,
1059 new->flags
& IRQF_TRIGGER_MASK
);
1065 desc
->istate
&= ~(IRQS_AUTODETECT
| IRQS_SPURIOUS_DISABLED
| \
1066 IRQS_ONESHOT
| IRQS_WAITING
);
1067 irqd_clear(&desc
->irq_data
, IRQD_IRQ_INPROGRESS
);
1069 if (new->flags
& IRQF_PERCPU
) {
1070 irqd_set(&desc
->irq_data
, IRQD_PER_CPU
);
1071 irq_settings_set_per_cpu(desc
);
1074 if (new->flags
& IRQF_ONESHOT
)
1075 desc
->istate
|= IRQS_ONESHOT
;
1077 if (irq_settings_can_autoenable(desc
))
1078 irq_startup(desc
, true);
1080 /* Undo nested disables: */
1083 /* Exclude IRQ from balancing if requested */
1084 if (new->flags
& IRQF_NOBALANCING
) {
1085 irq_settings_set_no_balancing(desc
);
1086 irqd_set(&desc
->irq_data
, IRQD_NO_BALANCING
);
1089 /* Set default affinity mask once everything is setup */
1090 setup_affinity(irq
, desc
, mask
);
1092 } else if (new->flags
& IRQF_TRIGGER_MASK
) {
1093 unsigned int nmsk
= new->flags
& IRQF_TRIGGER_MASK
;
1094 unsigned int omsk
= irq_settings_get_trigger_mask(desc
);
1097 /* hope the handler works with current trigger mode */
1098 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1105 /* Reset broken irq detection when installing new handler */
1106 desc
->irq_count
= 0;
1107 desc
->irqs_unhandled
= 0;
1110 * Check whether we disabled the irq via the spurious handler
1111 * before. Reenable it and give it another chance.
1113 if (shared
&& (desc
->istate
& IRQS_SPURIOUS_DISABLED
)) {
1114 desc
->istate
&= ~IRQS_SPURIOUS_DISABLED
;
1115 __enable_irq(desc
, irq
, false);
1118 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1121 * Strictly no need to wake it up, but hung_task complains
1122 * when no hard interrupt wakes the thread up.
1125 wake_up_process(new->thread
);
1127 register_irq_proc(irq
, desc
);
1129 register_handler_proc(irq
, new);
1130 free_cpumask_var(mask
);
1135 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
1136 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1137 irq
, new->flags
, new->name
, old
->flags
, old
->name
);
1138 #ifdef CONFIG_DEBUG_SHIRQ
1145 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1146 free_cpumask_var(mask
);
1150 struct task_struct
*t
= new->thread
;
1157 module_put(desc
->owner
);
1162 * setup_irq - setup an interrupt
1163 * @irq: Interrupt line to setup
1164 * @act: irqaction for the interrupt
1166 * Used to statically setup interrupts in the early boot process.
1168 int setup_irq(unsigned int irq
, struct irqaction
*act
)
1171 struct irq_desc
*desc
= irq_to_desc(irq
);
1173 if (WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1175 chip_bus_lock(desc
);
1176 retval
= __setup_irq(irq
, desc
, act
);
1177 chip_bus_sync_unlock(desc
);
1181 EXPORT_SYMBOL_GPL(setup_irq
);
1184 * Internal function to unregister an irqaction - used to free
1185 * regular and special interrupts that are part of the architecture.
1187 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
1189 struct irq_desc
*desc
= irq_to_desc(irq
);
1190 struct irqaction
*action
, **action_ptr
;
1191 unsigned long flags
;
1193 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1198 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1201 * There can be multiple actions per IRQ descriptor, find the right
1202 * one based on the dev_id:
1204 action_ptr
= &desc
->action
;
1206 action
= *action_ptr
;
1209 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1210 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1215 if (action
->dev_id
== dev_id
)
1217 action_ptr
= &action
->next
;
1220 /* Found it - now remove it from the list of entries: */
1221 *action_ptr
= action
->next
;
1223 /* If this was the last handler, shut down the IRQ line: */
1228 /* make sure affinity_hint is cleaned up */
1229 if (WARN_ON_ONCE(desc
->affinity_hint
))
1230 desc
->affinity_hint
= NULL
;
1233 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1235 unregister_handler_proc(irq
, action
);
1237 /* Make sure it's not being used on another CPU: */
1238 synchronize_irq(irq
);
1240 #ifdef CONFIG_DEBUG_SHIRQ
1242 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1243 * event to happen even now it's being freed, so let's make sure that
1244 * is so by doing an extra call to the handler ....
1246 * ( We do this after actually deregistering it, to make sure that a
1247 * 'real' IRQ doesn't run in * parallel with our fake. )
1249 if (action
->flags
& IRQF_SHARED
) {
1250 local_irq_save(flags
);
1251 action
->handler(irq
, dev_id
);
1252 local_irq_restore(flags
);
1256 if (action
->thread
) {
1257 kthread_stop(action
->thread
);
1258 put_task_struct(action
->thread
);
1261 module_put(desc
->owner
);
1266 * remove_irq - free an interrupt
1267 * @irq: Interrupt line to free
1268 * @act: irqaction for the interrupt
1270 * Used to remove interrupts statically setup by the early boot process.
1272 void remove_irq(unsigned int irq
, struct irqaction
*act
)
1274 struct irq_desc
*desc
= irq_to_desc(irq
);
1276 if (desc
&& !WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1277 __free_irq(irq
, act
->dev_id
);
1279 EXPORT_SYMBOL_GPL(remove_irq
);
1282 * free_irq - free an interrupt allocated with request_irq
1283 * @irq: Interrupt line to free
1284 * @dev_id: Device identity to free
1286 * Remove an interrupt handler. The handler is removed and if the
1287 * interrupt line is no longer in use by any driver it is disabled.
1288 * On a shared IRQ the caller must ensure the interrupt is disabled
1289 * on the card it drives before calling this function. The function
1290 * does not return until any executing interrupts for this IRQ
1293 * This function must not be called from interrupt context.
1295 void free_irq(unsigned int irq
, void *dev_id
)
1297 struct irq_desc
*desc
= irq_to_desc(irq
);
1299 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1303 if (WARN_ON(desc
->affinity_notify
))
1304 desc
->affinity_notify
= NULL
;
1307 chip_bus_lock(desc
);
1308 kfree(__free_irq(irq
, dev_id
));
1309 chip_bus_sync_unlock(desc
);
1311 EXPORT_SYMBOL(free_irq
);
1314 * request_threaded_irq - allocate an interrupt line
1315 * @irq: Interrupt line to allocate
1316 * @handler: Function to be called when the IRQ occurs.
1317 * Primary handler for threaded interrupts
1318 * If NULL and thread_fn != NULL the default
1319 * primary handler is installed
1320 * @thread_fn: Function called from the irq handler thread
1321 * If NULL, no irq thread is created
1322 * @irqflags: Interrupt type flags
1323 * @devname: An ascii name for the claiming device
1324 * @dev_id: A cookie passed back to the handler function
1326 * This call allocates interrupt resources and enables the
1327 * interrupt line and IRQ handling. From the point this
1328 * call is made your handler function may be invoked. Since
1329 * your handler function must clear any interrupt the board
1330 * raises, you must take care both to initialise your hardware
1331 * and to set up the interrupt handler in the right order.
1333 * If you want to set up a threaded irq handler for your device
1334 * then you need to supply @handler and @thread_fn. @handler is
1335 * still called in hard interrupt context and has to check
1336 * whether the interrupt originates from the device. If yes it
1337 * needs to disable the interrupt on the device and return
1338 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1339 * @thread_fn. This split handler design is necessary to support
1340 * shared interrupts.
1342 * Dev_id must be globally unique. Normally the address of the
1343 * device data structure is used as the cookie. Since the handler
1344 * receives this value it makes sense to use it.
1346 * If your interrupt is shared you must pass a non NULL dev_id
1347 * as this is required when freeing the interrupt.
1351 * IRQF_SHARED Interrupt is shared
1352 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
1353 * IRQF_TRIGGER_* Specify active edge(s) or level
1356 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
1357 irq_handler_t thread_fn
, unsigned long irqflags
,
1358 const char *devname
, void *dev_id
)
1360 struct irqaction
*action
;
1361 struct irq_desc
*desc
;
1365 * Sanity-check: shared interrupts must pass in a real dev-ID,
1366 * otherwise we'll have trouble later trying to figure out
1367 * which interrupt is which (messes up the interrupt freeing
1370 if ((irqflags
& IRQF_SHARED
) && !dev_id
)
1373 desc
= irq_to_desc(irq
);
1377 if (!irq_settings_can_request(desc
) ||
1378 WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1384 handler
= irq_default_primary_handler
;
1387 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1391 action
->handler
= handler
;
1392 action
->thread_fn
= thread_fn
;
1393 action
->flags
= irqflags
;
1394 action
->name
= devname
;
1395 action
->dev_id
= dev_id
;
1397 chip_bus_lock(desc
);
1398 retval
= __setup_irq(irq
, desc
, action
);
1399 chip_bus_sync_unlock(desc
);
1404 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1405 if (!retval
&& (irqflags
& IRQF_SHARED
)) {
1407 * It's a shared IRQ -- the driver ought to be prepared for it
1408 * to happen immediately, so let's make sure....
1409 * We disable the irq to make sure that a 'real' IRQ doesn't
1410 * run in parallel with our fake.
1412 unsigned long flags
;
1415 local_irq_save(flags
);
1417 handler(irq
, dev_id
);
1419 local_irq_restore(flags
);
1425 EXPORT_SYMBOL(request_threaded_irq
);
1428 * request_any_context_irq - allocate an interrupt line
1429 * @irq: Interrupt line to allocate
1430 * @handler: Function to be called when the IRQ occurs.
1431 * Threaded handler for threaded interrupts.
1432 * @flags: Interrupt type flags
1433 * @name: An ascii name for the claiming device
1434 * @dev_id: A cookie passed back to the handler function
1436 * This call allocates interrupt resources and enables the
1437 * interrupt line and IRQ handling. It selects either a
1438 * hardirq or threaded handling method depending on the
1441 * On failure, it returns a negative value. On success,
1442 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1444 int request_any_context_irq(unsigned int irq
, irq_handler_t handler
,
1445 unsigned long flags
, const char *name
, void *dev_id
)
1447 struct irq_desc
*desc
= irq_to_desc(irq
);
1453 if (irq_settings_is_nested_thread(desc
)) {
1454 ret
= request_threaded_irq(irq
, NULL
, handler
,
1455 flags
, name
, dev_id
);
1456 return !ret
? IRQC_IS_NESTED
: ret
;
1459 ret
= request_irq(irq
, handler
, flags
, name
, dev_id
);
1460 return !ret
? IRQC_IS_HARDIRQ
: ret
;
1462 EXPORT_SYMBOL_GPL(request_any_context_irq
);
1464 void enable_percpu_irq(unsigned int irq
, unsigned int type
)
1466 unsigned int cpu
= smp_processor_id();
1467 unsigned long flags
;
1468 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1473 type
&= IRQ_TYPE_SENSE_MASK
;
1474 if (type
!= IRQ_TYPE_NONE
) {
1477 ret
= __irq_set_trigger(desc
, irq
, type
);
1480 WARN(1, "failed to set type for IRQ%d\n", irq
);
1485 irq_percpu_enable(desc
, cpu
);
1487 irq_put_desc_unlock(desc
, flags
);
1490 void disable_percpu_irq(unsigned int irq
)
1492 unsigned int cpu
= smp_processor_id();
1493 unsigned long flags
;
1494 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1499 irq_percpu_disable(desc
, cpu
);
1500 irq_put_desc_unlock(desc
, flags
);
1504 * Internal function to unregister a percpu irqaction.
1506 static struct irqaction
*__free_percpu_irq(unsigned int irq
, void __percpu
*dev_id
)
1508 struct irq_desc
*desc
= irq_to_desc(irq
);
1509 struct irqaction
*action
;
1510 unsigned long flags
;
1512 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1517 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1519 action
= desc
->action
;
1520 if (!action
|| action
->percpu_dev_id
!= dev_id
) {
1521 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1525 if (!cpumask_empty(desc
->percpu_enabled
)) {
1526 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1527 irq
, cpumask_first(desc
->percpu_enabled
));
1531 /* Found it - now remove it from the list of entries: */
1532 desc
->action
= NULL
;
1534 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1536 unregister_handler_proc(irq
, action
);
1538 module_put(desc
->owner
);
1542 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1547 * remove_percpu_irq - free a per-cpu interrupt
1548 * @irq: Interrupt line to free
1549 * @act: irqaction for the interrupt
1551 * Used to remove interrupts statically setup by the early boot process.
1553 void remove_percpu_irq(unsigned int irq
, struct irqaction
*act
)
1555 struct irq_desc
*desc
= irq_to_desc(irq
);
1557 if (desc
&& irq_settings_is_per_cpu_devid(desc
))
1558 __free_percpu_irq(irq
, act
->percpu_dev_id
);
1562 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1563 * @irq: Interrupt line to free
1564 * @dev_id: Device identity to free
1566 * Remove a percpu interrupt handler. The handler is removed, but
1567 * the interrupt line is not disabled. This must be done on each
1568 * CPU before calling this function. The function does not return
1569 * until any executing interrupts for this IRQ have completed.
1571 * This function must not be called from interrupt context.
1573 void free_percpu_irq(unsigned int irq
, void __percpu
*dev_id
)
1575 struct irq_desc
*desc
= irq_to_desc(irq
);
1577 if (!desc
|| !irq_settings_is_per_cpu_devid(desc
))
1580 chip_bus_lock(desc
);
1581 kfree(__free_percpu_irq(irq
, dev_id
));
1582 chip_bus_sync_unlock(desc
);
1586 * setup_percpu_irq - setup a per-cpu interrupt
1587 * @irq: Interrupt line to setup
1588 * @act: irqaction for the interrupt
1590 * Used to statically setup per-cpu interrupts in the early boot process.
1592 int setup_percpu_irq(unsigned int irq
, struct irqaction
*act
)
1594 struct irq_desc
*desc
= irq_to_desc(irq
);
1597 if (!desc
|| !irq_settings_is_per_cpu_devid(desc
))
1599 chip_bus_lock(desc
);
1600 retval
= __setup_irq(irq
, desc
, act
);
1601 chip_bus_sync_unlock(desc
);
1607 * request_percpu_irq - allocate a percpu interrupt line
1608 * @irq: Interrupt line to allocate
1609 * @handler: Function to be called when the IRQ occurs.
1610 * @devname: An ascii name for the claiming device
1611 * @dev_id: A percpu cookie passed back to the handler function
1613 * This call allocates interrupt resources, but doesn't
1614 * automatically enable the interrupt. It has to be done on each
1615 * CPU using enable_percpu_irq().
1617 * Dev_id must be globally unique. It is a per-cpu variable, and
1618 * the handler gets called with the interrupted CPU's instance of
1621 int request_percpu_irq(unsigned int irq
, irq_handler_t handler
,
1622 const char *devname
, void __percpu
*dev_id
)
1624 struct irqaction
*action
;
1625 struct irq_desc
*desc
;
1631 desc
= irq_to_desc(irq
);
1632 if (!desc
|| !irq_settings_can_request(desc
) ||
1633 !irq_settings_is_per_cpu_devid(desc
))
1636 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1640 action
->handler
= handler
;
1641 action
->flags
= IRQF_PERCPU
| IRQF_NO_SUSPEND
;
1642 action
->name
= devname
;
1643 action
->percpu_dev_id
= dev_id
;
1645 chip_bus_lock(desc
);
1646 retval
= __setup_irq(irq
, desc
, action
);
1647 chip_bus_sync_unlock(desc
);