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
= IS_ENABLED(CONFIG_IRQ_FORCED_THREADING_DEFAULT
);
29 static int __init
setup_forced_irqthreads(char *arg
)
31 force_irqthreads
= true;
34 static int __init
setup_no_irqthreads(char *arg
)
36 force_irqthreads
= false;
39 early_param("threadirqs", setup_forced_irqthreads
);
40 early_param("nothreadirqs", setup_no_irqthreads
);
43 static void __synchronize_hardirq(struct irq_desc
*desc
)
51 * Wait until we're out of the critical section. This might
52 * give the wrong answer due to the lack of memory barriers.
54 while (irqd_irq_inprogress(&desc
->irq_data
))
57 /* Ok, that indicated we're done: double-check carefully. */
58 raw_spin_lock_irqsave(&desc
->lock
, flags
);
59 inprogress
= irqd_irq_inprogress(&desc
->irq_data
);
60 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
62 /* Oops, that failed? */
67 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
68 * @irq: interrupt number to wait for
70 * This function waits for any pending hard IRQ handlers for this
71 * interrupt to complete before returning. If you use this
72 * function while holding a resource the IRQ handler may need you
73 * will deadlock. It does not take associated threaded handlers
76 * Do not use this for shutdown scenarios where you must be sure
77 * that all parts (hardirq and threaded handler) have completed.
79 * Returns: false if a threaded handler is active.
81 * This function may be called - with care - from IRQ context.
83 bool synchronize_hardirq(unsigned int irq
)
85 struct irq_desc
*desc
= irq_to_desc(irq
);
88 __synchronize_hardirq(desc
);
89 return !atomic_read(&desc
->threads_active
);
94 EXPORT_SYMBOL(synchronize_hardirq
);
97 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
98 * @irq: interrupt number to wait for
100 * This function waits for any pending IRQ handlers for this interrupt
101 * to complete before returning. If you use this function while
102 * holding a resource the IRQ handler may need you will deadlock.
104 * This function may be called - with care - from IRQ context.
106 void synchronize_irq(unsigned int irq
)
108 struct irq_desc
*desc
= irq_to_desc(irq
);
111 __synchronize_hardirq(desc
);
113 * We made sure that no hardirq handler is
114 * running. Now verify that no threaded handlers are
117 wait_event(desc
->wait_for_threads
,
118 !atomic_read(&desc
->threads_active
));
121 EXPORT_SYMBOL(synchronize_irq
);
124 cpumask_var_t irq_default_affinity
;
126 static bool __irq_can_set_affinity(struct irq_desc
*desc
)
128 if (!desc
|| !irqd_can_balance(&desc
->irq_data
) ||
129 !desc
->irq_data
.chip
|| !desc
->irq_data
.chip
->irq_set_affinity
)
135 * irq_can_set_affinity - Check if the affinity of a given irq can be set
136 * @irq: Interrupt to check
139 int irq_can_set_affinity(unsigned int irq
)
141 return __irq_can_set_affinity(irq_to_desc(irq
));
145 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
146 * @irq: Interrupt to check
148 * Like irq_can_set_affinity() above, but additionally checks for the
149 * AFFINITY_MANAGED flag.
151 bool irq_can_set_affinity_usr(unsigned int irq
)
153 struct irq_desc
*desc
= irq_to_desc(irq
);
155 return __irq_can_set_affinity(desc
) &&
156 !irqd_affinity_is_managed(&desc
->irq_data
);
160 * irq_set_thread_affinity - Notify irq threads to adjust affinity
161 * @desc: irq descriptor which has affitnity changed
163 * We just set IRQTF_AFFINITY and delegate the affinity setting
164 * to the interrupt thread itself. We can not call
165 * set_cpus_allowed_ptr() here as we hold desc->lock and this
166 * code can be called from hard interrupt context.
168 void irq_set_thread_affinity(struct irq_desc
*desc
)
170 struct irqaction
*action
;
172 for_each_action_of_desc(desc
, action
)
174 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
177 int irq_do_set_affinity(struct irq_data
*data
, const struct cpumask
*mask
,
180 struct irq_desc
*desc
= irq_data_to_desc(data
);
181 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
184 if (!chip
|| !chip
->irq_set_affinity
)
187 ret
= chip
->irq_set_affinity(data
, mask
, force
);
189 case IRQ_SET_MASK_OK
:
190 case IRQ_SET_MASK_OK_DONE
:
191 cpumask_copy(desc
->irq_common_data
.affinity
, mask
);
192 case IRQ_SET_MASK_OK_NOCOPY
:
193 irq_set_thread_affinity(desc
);
200 int irq_set_affinity_locked(struct irq_data
*data
, const struct cpumask
*mask
,
203 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
204 struct irq_desc
*desc
= irq_data_to_desc(data
);
207 if (!chip
|| !chip
->irq_set_affinity
)
210 if (irq_can_move_pcntxt(data
)) {
211 ret
= irq_do_set_affinity(data
, mask
, force
);
213 irqd_set_move_pending(data
);
214 irq_copy_pending(desc
, mask
);
217 if (desc
->affinity_notify
) {
218 kref_get(&desc
->affinity_notify
->kref
);
219 schedule_work(&desc
->affinity_notify
->work
);
221 irqd_set(data
, IRQD_AFFINITY_SET
);
226 int __irq_set_affinity(unsigned int irq
, const struct cpumask
*mask
, bool force
)
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
, force
);
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
);
250 /* set the initial affinity to prevent every interrupt being on CPU0 */
252 __irq_set_affinity(irq
, m
, false);
255 EXPORT_SYMBOL_GPL(irq_set_affinity_hint
);
257 static void irq_affinity_notify(struct work_struct
*work
)
259 struct irq_affinity_notify
*notify
=
260 container_of(work
, struct irq_affinity_notify
, work
);
261 struct irq_desc
*desc
= irq_to_desc(notify
->irq
);
262 cpumask_var_t cpumask
;
265 if (!desc
|| !alloc_cpumask_var(&cpumask
, GFP_KERNEL
))
268 raw_spin_lock_irqsave(&desc
->lock
, flags
);
269 if (irq_move_pending(&desc
->irq_data
))
270 irq_get_pending(cpumask
, desc
);
272 cpumask_copy(cpumask
, desc
->irq_common_data
.affinity
);
273 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
275 notify
->notify(notify
, cpumask
);
277 free_cpumask_var(cpumask
);
279 kref_put(¬ify
->kref
, notify
->release
);
283 * irq_set_affinity_notifier - control notification of IRQ affinity changes
284 * @irq: Interrupt for which to enable/disable notification
285 * @notify: Context for notification, or %NULL to disable
286 * notification. Function pointers must be initialised;
287 * the other fields will be initialised by this function.
289 * Must be called in process context. Notification may only be enabled
290 * after the IRQ is allocated and must be disabled before the IRQ is
291 * freed using free_irq().
294 irq_set_affinity_notifier(unsigned int irq
, struct irq_affinity_notify
*notify
)
296 struct irq_desc
*desc
= irq_to_desc(irq
);
297 struct irq_affinity_notify
*old_notify
;
300 /* The release function is promised process context */
306 /* Complete initialisation of *notify */
309 kref_init(¬ify
->kref
);
310 INIT_WORK(¬ify
->work
, irq_affinity_notify
);
313 raw_spin_lock_irqsave(&desc
->lock
, flags
);
314 old_notify
= desc
->affinity_notify
;
315 desc
->affinity_notify
= notify
;
316 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
319 kref_put(&old_notify
->kref
, old_notify
->release
);
323 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier
);
325 #ifndef CONFIG_AUTO_IRQ_AFFINITY
327 * Generic version of the affinity autoselector.
329 int irq_setup_affinity(struct irq_desc
*desc
)
331 struct cpumask
*set
= irq_default_affinity
;
332 int ret
, node
= irq_desc_get_node(desc
);
333 static DEFINE_RAW_SPINLOCK(mask_lock
);
334 static struct cpumask mask
;
336 /* Excludes PER_CPU and NO_BALANCE interrupts */
337 if (!__irq_can_set_affinity(desc
))
340 raw_spin_lock(&mask_lock
);
342 * Preserve the managed affinity setting and a userspace affinity
343 * setup, but make sure that one of the targets is online.
345 if (irqd_affinity_is_managed(&desc
->irq_data
) ||
346 irqd_has_set(&desc
->irq_data
, IRQD_AFFINITY_SET
)) {
347 if (cpumask_intersects(desc
->irq_common_data
.affinity
,
349 set
= desc
->irq_common_data
.affinity
;
351 irqd_clear(&desc
->irq_data
, IRQD_AFFINITY_SET
);
354 cpumask_and(&mask
, cpu_online_mask
, set
);
355 if (node
!= NUMA_NO_NODE
) {
356 const struct cpumask
*nodemask
= cpumask_of_node(node
);
358 /* make sure at least one of the cpus in nodemask is online */
359 if (cpumask_intersects(&mask
, nodemask
))
360 cpumask_and(&mask
, &mask
, nodemask
);
362 ret
= irq_do_set_affinity(&desc
->irq_data
, &mask
, false);
363 raw_spin_unlock(&mask_lock
);
367 /* Wrapper for ALPHA specific affinity selector magic */
368 int irq_setup_affinity(struct irq_desc
*desc
)
370 return irq_select_affinity(irq_desc_get_irq(desc
));
375 * Called when a bogus affinity is set via /proc/irq
377 int irq_select_affinity_usr(unsigned int irq
)
379 struct irq_desc
*desc
= irq_to_desc(irq
);
383 raw_spin_lock_irqsave(&desc
->lock
, flags
);
384 ret
= irq_setup_affinity(desc
);
385 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
391 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
392 * @irq: interrupt number to set affinity
393 * @vcpu_info: vCPU specific data
395 * This function uses the vCPU specific data to set the vCPU
396 * affinity for an irq. The vCPU specific data is passed from
397 * outside, such as KVM. One example code path is as below:
398 * KVM -> IOMMU -> irq_set_vcpu_affinity().
400 int irq_set_vcpu_affinity(unsigned int irq
, void *vcpu_info
)
403 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
404 struct irq_data
*data
;
405 struct irq_chip
*chip
;
411 data
= irq_desc_get_irq_data(desc
);
412 chip
= irq_data_get_irq_chip(data
);
413 if (chip
&& chip
->irq_set_vcpu_affinity
)
414 ret
= chip
->irq_set_vcpu_affinity(data
, vcpu_info
);
415 irq_put_desc_unlock(desc
, flags
);
419 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity
);
421 void __disable_irq(struct irq_desc
*desc
)
427 static int __disable_irq_nosync(unsigned int irq
)
430 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
435 irq_put_desc_busunlock(desc
, flags
);
440 * disable_irq_nosync - disable an irq without waiting
441 * @irq: Interrupt to disable
443 * Disable the selected interrupt line. Disables and Enables are
445 * Unlike disable_irq(), this function does not ensure existing
446 * instances of the IRQ handler have completed before returning.
448 * This function may be called from IRQ context.
450 void disable_irq_nosync(unsigned int irq
)
452 __disable_irq_nosync(irq
);
454 EXPORT_SYMBOL(disable_irq_nosync
);
457 * disable_irq - disable an irq and wait for completion
458 * @irq: Interrupt to disable
460 * Disable the selected interrupt line. Enables and Disables are
462 * This function waits for any pending IRQ handlers for this interrupt
463 * to complete before returning. If you use this function while
464 * holding a resource the IRQ handler may need you will deadlock.
466 * This function may be called - with care - from IRQ context.
468 void disable_irq(unsigned int irq
)
470 if (!__disable_irq_nosync(irq
))
471 synchronize_irq(irq
);
473 EXPORT_SYMBOL(disable_irq
);
476 * disable_hardirq - disables an irq and waits for hardirq completion
477 * @irq: Interrupt to disable
479 * Disable the selected interrupt line. Enables and Disables are
481 * This function waits for any pending hard IRQ handlers for this
482 * interrupt to complete before returning. If you use this function while
483 * holding a resource the hard IRQ handler may need you will deadlock.
485 * When used to optimistically disable an interrupt from atomic context
486 * the return value must be checked.
488 * Returns: false if a threaded handler is active.
490 * This function may be called - with care - from IRQ context.
492 bool disable_hardirq(unsigned int irq
)
494 if (!__disable_irq_nosync(irq
))
495 return synchronize_hardirq(irq
);
499 EXPORT_SYMBOL_GPL(disable_hardirq
);
501 void __enable_irq(struct irq_desc
*desc
)
503 switch (desc
->depth
) {
506 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n",
507 irq_desc_get_irq(desc
));
510 if (desc
->istate
& IRQS_SUSPENDED
)
512 /* Prevent probing on this irq: */
513 irq_settings_set_noprobe(desc
);
515 * Call irq_startup() not irq_enable() here because the
516 * interrupt might be marked NOAUTOEN. So irq_startup()
517 * needs to be invoked when it gets enabled the first
518 * time. If it was already started up, then irq_startup()
519 * will invoke irq_enable() under the hood.
521 irq_startup(desc
, IRQ_RESEND
, IRQ_START_COND
);
530 * enable_irq - enable handling of an irq
531 * @irq: Interrupt to enable
533 * Undoes the effect of one call to disable_irq(). If this
534 * matches the last disable, processing of interrupts on this
535 * IRQ line is re-enabled.
537 * This function may be called from IRQ context only when
538 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
540 void enable_irq(unsigned int irq
)
543 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
547 if (WARN(!desc
->irq_data
.chip
,
548 KERN_ERR
"enable_irq before setup/request_irq: irq %u\n", irq
))
553 irq_put_desc_busunlock(desc
, flags
);
555 EXPORT_SYMBOL(enable_irq
);
557 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
559 struct irq_desc
*desc
= irq_to_desc(irq
);
562 if (irq_desc_get_chip(desc
)->flags
& IRQCHIP_SKIP_SET_WAKE
)
565 if (desc
->irq_data
.chip
->irq_set_wake
)
566 ret
= desc
->irq_data
.chip
->irq_set_wake(&desc
->irq_data
, on
);
572 * irq_set_irq_wake - control irq power management wakeup
573 * @irq: interrupt to control
574 * @on: enable/disable power management wakeup
576 * Enable/disable power management wakeup mode, which is
577 * disabled by default. Enables and disables must match,
578 * just as they match for non-wakeup mode support.
580 * Wakeup mode lets this IRQ wake the system from sleep
581 * states like "suspend to RAM".
583 int irq_set_irq_wake(unsigned int irq
, unsigned int on
)
586 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
592 /* wakeup-capable irqs can be shared between drivers that
593 * don't need to have the same sleep mode behaviors.
596 if (desc
->wake_depth
++ == 0) {
597 ret
= set_irq_wake_real(irq
, on
);
599 desc
->wake_depth
= 0;
601 irqd_set(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
604 if (desc
->wake_depth
== 0) {
605 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
606 } else if (--desc
->wake_depth
== 0) {
607 ret
= set_irq_wake_real(irq
, on
);
609 desc
->wake_depth
= 1;
611 irqd_clear(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
614 irq_put_desc_busunlock(desc
, flags
);
617 EXPORT_SYMBOL(irq_set_irq_wake
);
620 * Internal function that tells the architecture code whether a
621 * particular irq has been exclusively allocated or is available
624 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
627 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
633 if (irq_settings_can_request(desc
)) {
635 irqflags
& desc
->action
->flags
& IRQF_SHARED
)
638 irq_put_desc_unlock(desc
, flags
);
642 int __irq_set_trigger(struct irq_desc
*desc
, unsigned long flags
)
644 struct irq_chip
*chip
= desc
->irq_data
.chip
;
647 if (!chip
|| !chip
->irq_set_type
) {
649 * IRQF_TRIGGER_* but the PIC does not support multiple
652 pr_debug("No set_type function for IRQ %d (%s)\n",
653 irq_desc_get_irq(desc
),
654 chip
? (chip
->name
? : "unknown") : "unknown");
658 if (chip
->flags
& IRQCHIP_SET_TYPE_MASKED
) {
659 if (!irqd_irq_masked(&desc
->irq_data
))
661 if (!irqd_irq_disabled(&desc
->irq_data
))
665 /* Mask all flags except trigger mode */
666 flags
&= IRQ_TYPE_SENSE_MASK
;
667 ret
= chip
->irq_set_type(&desc
->irq_data
, flags
);
670 case IRQ_SET_MASK_OK
:
671 case IRQ_SET_MASK_OK_DONE
:
672 irqd_clear(&desc
->irq_data
, IRQD_TRIGGER_MASK
);
673 irqd_set(&desc
->irq_data
, flags
);
675 case IRQ_SET_MASK_OK_NOCOPY
:
676 flags
= irqd_get_trigger_type(&desc
->irq_data
);
677 irq_settings_set_trigger_mask(desc
, flags
);
678 irqd_clear(&desc
->irq_data
, IRQD_LEVEL
);
679 irq_settings_clr_level(desc
);
680 if (flags
& IRQ_TYPE_LEVEL_MASK
) {
681 irq_settings_set_level(desc
);
682 irqd_set(&desc
->irq_data
, IRQD_LEVEL
);
688 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
689 flags
, irq_desc_get_irq(desc
), chip
->irq_set_type
);
696 #ifdef CONFIG_HARDIRQS_SW_RESEND
697 int irq_set_parent(int irq
, int parent_irq
)
700 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
705 desc
->parent_irq
= parent_irq
;
707 irq_put_desc_unlock(desc
, flags
);
710 EXPORT_SYMBOL_GPL(irq_set_parent
);
714 * Default primary interrupt handler for threaded interrupts. Is
715 * assigned as primary handler when request_threaded_irq is called
716 * with handler == NULL. Useful for oneshot interrupts.
718 static irqreturn_t
irq_default_primary_handler(int irq
, void *dev_id
)
720 return IRQ_WAKE_THREAD
;
724 * Primary handler for nested threaded interrupts. Should never be
727 static irqreturn_t
irq_nested_primary_handler(int irq
, void *dev_id
)
729 WARN(1, "Primary handler called for nested irq %d\n", irq
);
733 static irqreturn_t
irq_forced_secondary_handler(int irq
, void *dev_id
)
735 WARN(1, "Secondary action handler called for irq %d\n", irq
);
739 static int irq_wait_for_interrupt(struct irqaction
*action
)
741 set_current_state(TASK_INTERRUPTIBLE
);
743 while (!kthread_should_stop()) {
745 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
746 &action
->thread_flags
)) {
747 __set_current_state(TASK_RUNNING
);
751 set_current_state(TASK_INTERRUPTIBLE
);
753 __set_current_state(TASK_RUNNING
);
758 * Oneshot interrupts keep the irq line masked until the threaded
759 * handler finished. unmask if the interrupt has not been disabled and
762 static void irq_finalize_oneshot(struct irq_desc
*desc
,
763 struct irqaction
*action
)
765 if (!(desc
->istate
& IRQS_ONESHOT
) ||
766 action
->handler
== irq_forced_secondary_handler
)
770 raw_spin_lock_irq(&desc
->lock
);
773 * Implausible though it may be we need to protect us against
774 * the following scenario:
776 * The thread is faster done than the hard interrupt handler
777 * on the other CPU. If we unmask the irq line then the
778 * interrupt can come in again and masks the line, leaves due
779 * to IRQS_INPROGRESS and the irq line is masked forever.
781 * This also serializes the state of shared oneshot handlers
782 * versus "desc->threads_onehsot |= action->thread_mask;" in
783 * irq_wake_thread(). See the comment there which explains the
786 if (unlikely(irqd_irq_inprogress(&desc
->irq_data
))) {
787 raw_spin_unlock_irq(&desc
->lock
);
788 chip_bus_sync_unlock(desc
);
794 * Now check again, whether the thread should run. Otherwise
795 * we would clear the threads_oneshot bit of this thread which
798 if (test_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
801 desc
->threads_oneshot
&= ~action
->thread_mask
;
803 if (!desc
->threads_oneshot
&& !irqd_irq_disabled(&desc
->irq_data
) &&
804 irqd_irq_masked(&desc
->irq_data
))
805 unmask_threaded_irq(desc
);
808 raw_spin_unlock_irq(&desc
->lock
);
809 chip_bus_sync_unlock(desc
);
814 * Check whether we need to change the affinity of the interrupt thread.
817 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
)
822 if (!test_and_clear_bit(IRQTF_AFFINITY
, &action
->thread_flags
))
826 * In case we are out of memory we set IRQTF_AFFINITY again and
827 * try again next time
829 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
830 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
834 raw_spin_lock_irq(&desc
->lock
);
836 * This code is triggered unconditionally. Check the affinity
837 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
839 if (cpumask_available(desc
->irq_common_data
.affinity
))
840 cpumask_copy(mask
, desc
->irq_common_data
.affinity
);
843 raw_spin_unlock_irq(&desc
->lock
);
846 set_cpus_allowed_ptr(current
, mask
);
847 free_cpumask_var(mask
);
851 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
) { }
855 * Interrupts which are not explicitely requested as threaded
856 * interrupts rely on the implicit bh/preempt disable of the hard irq
857 * context. So we need to disable bh here to avoid deadlocks and other
861 irq_forced_thread_fn(struct irq_desc
*desc
, struct irqaction
*action
)
866 ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
867 irq_finalize_oneshot(desc
, action
);
873 * Interrupts explicitly requested as threaded interrupts want to be
874 * preemtible - many of them need to sleep and wait for slow busses to
877 static irqreturn_t
irq_thread_fn(struct irq_desc
*desc
,
878 struct irqaction
*action
)
882 ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
883 irq_finalize_oneshot(desc
, action
);
887 static void wake_threads_waitq(struct irq_desc
*desc
)
889 if (atomic_dec_and_test(&desc
->threads_active
))
890 wake_up(&desc
->wait_for_threads
);
893 static void irq_thread_dtor(struct callback_head
*unused
)
895 struct task_struct
*tsk
= current
;
896 struct irq_desc
*desc
;
897 struct irqaction
*action
;
899 if (WARN_ON_ONCE(!(current
->flags
& PF_EXITING
)))
902 action
= kthread_data(tsk
);
904 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
905 tsk
->comm
, tsk
->pid
, action
->irq
);
908 desc
= irq_to_desc(action
->irq
);
910 * If IRQTF_RUNTHREAD is set, we need to decrement
911 * desc->threads_active and wake possible waiters.
913 if (test_and_clear_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
914 wake_threads_waitq(desc
);
916 /* Prevent a stale desc->threads_oneshot */
917 irq_finalize_oneshot(desc
, action
);
920 static void irq_wake_secondary(struct irq_desc
*desc
, struct irqaction
*action
)
922 struct irqaction
*secondary
= action
->secondary
;
924 if (WARN_ON_ONCE(!secondary
))
927 raw_spin_lock_irq(&desc
->lock
);
928 __irq_wake_thread(desc
, secondary
);
929 raw_spin_unlock_irq(&desc
->lock
);
933 * Interrupt handler thread
935 static int irq_thread(void *data
)
937 struct callback_head on_exit_work
;
938 struct irqaction
*action
= data
;
939 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
940 irqreturn_t (*handler_fn
)(struct irq_desc
*desc
,
941 struct irqaction
*action
);
943 if (force_irqthreads
&& test_bit(IRQTF_FORCED_THREAD
,
944 &action
->thread_flags
))
945 handler_fn
= irq_forced_thread_fn
;
947 handler_fn
= irq_thread_fn
;
949 init_task_work(&on_exit_work
, irq_thread_dtor
);
950 task_work_add(current
, &on_exit_work
, false);
952 irq_thread_check_affinity(desc
, action
);
954 while (!irq_wait_for_interrupt(action
)) {
955 irqreturn_t action_ret
;
957 irq_thread_check_affinity(desc
, action
);
959 action_ret
= handler_fn(desc
, action
);
960 if (action_ret
== IRQ_HANDLED
)
961 atomic_inc(&desc
->threads_handled
);
962 if (action_ret
== IRQ_WAKE_THREAD
)
963 irq_wake_secondary(desc
, action
);
965 wake_threads_waitq(desc
);
969 * This is the regular exit path. __free_irq() is stopping the
970 * thread via kthread_stop() after calling
971 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
972 * oneshot mask bit can be set. We cannot verify that as we
973 * cannot touch the oneshot mask at this point anymore as
974 * __setup_irq() might have given out currents thread_mask
977 task_work_cancel(current
, irq_thread_dtor
);
982 * irq_wake_thread - wake the irq thread for the action identified by dev_id
983 * @irq: Interrupt line
984 * @dev_id: Device identity for which the thread should be woken
987 void irq_wake_thread(unsigned int irq
, void *dev_id
)
989 struct irq_desc
*desc
= irq_to_desc(irq
);
990 struct irqaction
*action
;
993 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
996 raw_spin_lock_irqsave(&desc
->lock
, flags
);
997 for_each_action_of_desc(desc
, action
) {
998 if (action
->dev_id
== dev_id
) {
1000 __irq_wake_thread(desc
, action
);
1004 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1006 EXPORT_SYMBOL_GPL(irq_wake_thread
);
1008 static int irq_setup_forced_threading(struct irqaction
*new)
1010 if (!force_irqthreads
)
1012 if (new->flags
& (IRQF_NO_THREAD
| IRQF_PERCPU
| IRQF_ONESHOT
))
1015 new->flags
|= IRQF_ONESHOT
;
1018 * Handle the case where we have a real primary handler and a
1019 * thread handler. We force thread them as well by creating a
1022 if (new->handler
!= irq_default_primary_handler
&& new->thread_fn
) {
1023 /* Allocate the secondary action */
1024 new->secondary
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1025 if (!new->secondary
)
1027 new->secondary
->handler
= irq_forced_secondary_handler
;
1028 new->secondary
->thread_fn
= new->thread_fn
;
1029 new->secondary
->dev_id
= new->dev_id
;
1030 new->secondary
->irq
= new->irq
;
1031 new->secondary
->name
= new->name
;
1033 /* Deal with the primary handler */
1034 set_bit(IRQTF_FORCED_THREAD
, &new->thread_flags
);
1035 new->thread_fn
= new->handler
;
1036 new->handler
= irq_default_primary_handler
;
1040 static int irq_request_resources(struct irq_desc
*desc
)
1042 struct irq_data
*d
= &desc
->irq_data
;
1043 struct irq_chip
*c
= d
->chip
;
1045 return c
->irq_request_resources
? c
->irq_request_resources(d
) : 0;
1048 static void irq_release_resources(struct irq_desc
*desc
)
1050 struct irq_data
*d
= &desc
->irq_data
;
1051 struct irq_chip
*c
= d
->chip
;
1053 if (c
->irq_release_resources
)
1054 c
->irq_release_resources(d
);
1058 setup_irq_thread(struct irqaction
*new, unsigned int irq
, bool secondary
)
1060 struct task_struct
*t
;
1061 struct sched_param param
= {
1062 .sched_priority
= MAX_USER_RT_PRIO
/2,
1066 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
1069 t
= kthread_create(irq_thread
, new, "irq/%d-s-%s", irq
,
1071 param
.sched_priority
-= 1;
1077 sched_setscheduler_nocheck(t
, SCHED_FIFO
, ¶m
);
1080 * We keep the reference to the task struct even if
1081 * the thread dies to avoid that the interrupt code
1082 * references an already freed task_struct.
1087 * Tell the thread to set its affinity. This is
1088 * important for shared interrupt handlers as we do
1089 * not invoke setup_affinity() for the secondary
1090 * handlers as everything is already set up. Even for
1091 * interrupts marked with IRQF_NO_BALANCE this is
1092 * correct as we want the thread to move to the cpu(s)
1093 * on which the requesting code placed the interrupt.
1095 set_bit(IRQTF_AFFINITY
, &new->thread_flags
);
1100 * Internal function to register an irqaction - typically used to
1101 * allocate special interrupts that are part of the architecture.
1105 * desc->request_mutex Provides serialization against a concurrent free_irq()
1106 * chip_bus_lock Provides serialization for slow bus operations
1107 * desc->lock Provides serialization against hard interrupts
1109 * chip_bus_lock and desc->lock are sufficient for all other management and
1110 * interrupt related functions. desc->request_mutex solely serializes
1111 * request/free_irq().
1114 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
1116 struct irqaction
*old
, **old_ptr
;
1117 unsigned long flags
, thread_mask
= 0;
1118 int ret
, nested
, shared
= 0;
1123 if (desc
->irq_data
.chip
== &no_irq_chip
)
1125 if (!try_module_get(desc
->owner
))
1131 * If the trigger type is not specified by the caller,
1132 * then use the default for this interrupt.
1134 if (!(new->flags
& IRQF_TRIGGER_MASK
))
1135 new->flags
|= irqd_get_trigger_type(&desc
->irq_data
);
1138 * Check whether the interrupt nests into another interrupt
1141 nested
= irq_settings_is_nested_thread(desc
);
1143 if (!new->thread_fn
) {
1148 * Replace the primary handler which was provided from
1149 * the driver for non nested interrupt handling by the
1150 * dummy function which warns when called.
1152 new->handler
= irq_nested_primary_handler
;
1154 if (irq_settings_can_thread(desc
)) {
1155 ret
= irq_setup_forced_threading(new);
1162 * Create a handler thread when a thread function is supplied
1163 * and the interrupt does not nest into another interrupt
1166 if (new->thread_fn
&& !nested
) {
1167 ret
= setup_irq_thread(new, irq
, false);
1170 if (new->secondary
) {
1171 ret
= setup_irq_thread(new->secondary
, irq
, true);
1178 * Drivers are often written to work w/o knowledge about the
1179 * underlying irq chip implementation, so a request for a
1180 * threaded irq without a primary hard irq context handler
1181 * requires the ONESHOT flag to be set. Some irq chips like
1182 * MSI based interrupts are per se one shot safe. Check the
1183 * chip flags, so we can avoid the unmask dance at the end of
1184 * the threaded handler for those.
1186 if (desc
->irq_data
.chip
->flags
& IRQCHIP_ONESHOT_SAFE
)
1187 new->flags
&= ~IRQF_ONESHOT
;
1190 * Protects against a concurrent __free_irq() call which might wait
1191 * for synchronize_irq() to complete without holding the optional
1192 * chip bus lock and desc->lock.
1194 mutex_lock(&desc
->request_mutex
);
1197 * Acquire bus lock as the irq_request_resources() callback below
1198 * might rely on the serialization or the magic power management
1199 * functions which are abusing the irq_bus_lock() callback,
1201 chip_bus_lock(desc
);
1203 /* First installed action requests resources. */
1204 if (!desc
->action
) {
1205 ret
= irq_request_resources(desc
);
1207 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1208 new->name
, irq
, desc
->irq_data
.chip
->name
);
1209 goto out_bus_unlock
;
1214 * The following block of code has to be executed atomically
1215 * protected against a concurrent interrupt and any of the other
1216 * management calls which are not serialized via
1217 * desc->request_mutex or the optional bus lock.
1219 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1220 old_ptr
= &desc
->action
;
1224 * Can't share interrupts unless both agree to and are
1225 * the same type (level, edge, polarity). So both flag
1226 * fields must have IRQF_SHARED set and the bits which
1227 * set the trigger type must match. Also all must
1230 unsigned int oldtype
= irqd_get_trigger_type(&desc
->irq_data
);
1232 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
1233 (oldtype
!= (new->flags
& IRQF_TRIGGER_MASK
)) ||
1234 ((old
->flags
^ new->flags
) & IRQF_ONESHOT
))
1237 /* All handlers must agree on per-cpuness */
1238 if ((old
->flags
& IRQF_PERCPU
) !=
1239 (new->flags
& IRQF_PERCPU
))
1242 /* add new interrupt at end of irq queue */
1245 * Or all existing action->thread_mask bits,
1246 * so we can find the next zero bit for this
1249 thread_mask
|= old
->thread_mask
;
1250 old_ptr
= &old
->next
;
1257 * Setup the thread mask for this irqaction for ONESHOT. For
1258 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1259 * conditional in irq_wake_thread().
1261 if (new->flags
& IRQF_ONESHOT
) {
1263 * Unlikely to have 32 resp 64 irqs sharing one line,
1266 if (thread_mask
== ~0UL) {
1271 * The thread_mask for the action is or'ed to
1272 * desc->thread_active to indicate that the
1273 * IRQF_ONESHOT thread handler has been woken, but not
1274 * yet finished. The bit is cleared when a thread
1275 * completes. When all threads of a shared interrupt
1276 * line have completed desc->threads_active becomes
1277 * zero and the interrupt line is unmasked. See
1278 * handle.c:irq_wake_thread() for further information.
1280 * If no thread is woken by primary (hard irq context)
1281 * interrupt handlers, then desc->threads_active is
1282 * also checked for zero to unmask the irq line in the
1283 * affected hard irq flow handlers
1284 * (handle_[fasteoi|level]_irq).
1286 * The new action gets the first zero bit of
1287 * thread_mask assigned. See the loop above which or's
1288 * all existing action->thread_mask bits.
1290 new->thread_mask
= 1 << ffz(thread_mask
);
1292 } else if (new->handler
== irq_default_primary_handler
&&
1293 !(desc
->irq_data
.chip
->flags
& IRQCHIP_ONESHOT_SAFE
)) {
1295 * The interrupt was requested with handler = NULL, so
1296 * we use the default primary handler for it. But it
1297 * does not have the oneshot flag set. In combination
1298 * with level interrupts this is deadly, because the
1299 * default primary handler just wakes the thread, then
1300 * the irq lines is reenabled, but the device still
1301 * has the level irq asserted. Rinse and repeat....
1303 * While this works for edge type interrupts, we play
1304 * it safe and reject unconditionally because we can't
1305 * say for sure which type this interrupt really
1306 * has. The type flags are unreliable as the
1307 * underlying chip implementation can override them.
1309 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1316 init_waitqueue_head(&desc
->wait_for_threads
);
1318 /* Setup the type (level, edge polarity) if configured: */
1319 if (new->flags
& IRQF_TRIGGER_MASK
) {
1320 ret
= __irq_set_trigger(desc
,
1321 new->flags
& IRQF_TRIGGER_MASK
);
1327 desc
->istate
&= ~(IRQS_AUTODETECT
| IRQS_SPURIOUS_DISABLED
| \
1328 IRQS_ONESHOT
| IRQS_WAITING
);
1329 irqd_clear(&desc
->irq_data
, IRQD_IRQ_INPROGRESS
);
1331 if (new->flags
& IRQF_PERCPU
) {
1332 irqd_set(&desc
->irq_data
, IRQD_PER_CPU
);
1333 irq_settings_set_per_cpu(desc
);
1336 if (new->flags
& IRQF_ONESHOT
)
1337 desc
->istate
|= IRQS_ONESHOT
;
1339 /* Exclude IRQ from balancing if requested */
1340 if (new->flags
& IRQF_NOBALANCING
) {
1341 irq_settings_set_no_balancing(desc
);
1342 irqd_set(&desc
->irq_data
, IRQD_NO_BALANCING
);
1345 if (irq_settings_can_autoenable(desc
)) {
1346 irq_startup(desc
, IRQ_RESEND
, IRQ_START_COND
);
1349 * Shared interrupts do not go well with disabling
1350 * auto enable. The sharing interrupt might request
1351 * it while it's still disabled and then wait for
1352 * interrupts forever.
1354 WARN_ON_ONCE(new->flags
& IRQF_SHARED
);
1355 /* Undo nested disables: */
1359 } else if (new->flags
& IRQF_TRIGGER_MASK
) {
1360 unsigned int nmsk
= new->flags
& IRQF_TRIGGER_MASK
;
1361 unsigned int omsk
= irqd_get_trigger_type(&desc
->irq_data
);
1364 /* hope the handler works with current trigger mode */
1365 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1371 irq_pm_install_action(desc
, new);
1373 /* Reset broken irq detection when installing new handler */
1374 desc
->irq_count
= 0;
1375 desc
->irqs_unhandled
= 0;
1378 * Check whether we disabled the irq via the spurious handler
1379 * before. Reenable it and give it another chance.
1381 if (shared
&& (desc
->istate
& IRQS_SPURIOUS_DISABLED
)) {
1382 desc
->istate
&= ~IRQS_SPURIOUS_DISABLED
;
1386 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1387 chip_bus_sync_unlock(desc
);
1388 mutex_unlock(&desc
->request_mutex
);
1390 irq_setup_timings(desc
, new);
1393 * Strictly no need to wake it up, but hung_task complains
1394 * when no hard interrupt wakes the thread up.
1397 wake_up_process(new->thread
);
1399 wake_up_process(new->secondary
->thread
);
1401 register_irq_proc(irq
, desc
);
1402 irq_add_debugfs_entry(irq
, desc
);
1404 register_handler_proc(irq
, new);
1408 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
1409 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1410 irq
, new->flags
, new->name
, old
->flags
, old
->name
);
1411 #ifdef CONFIG_DEBUG_SHIRQ
1418 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1421 irq_release_resources(desc
);
1423 chip_bus_sync_unlock(desc
);
1424 mutex_unlock(&desc
->request_mutex
);
1428 struct task_struct
*t
= new->thread
;
1434 if (new->secondary
&& new->secondary
->thread
) {
1435 struct task_struct
*t
= new->secondary
->thread
;
1437 new->secondary
->thread
= NULL
;
1442 module_put(desc
->owner
);
1447 * setup_irq - setup an interrupt
1448 * @irq: Interrupt line to setup
1449 * @act: irqaction for the interrupt
1451 * Used to statically setup interrupts in the early boot process.
1453 int setup_irq(unsigned int irq
, struct irqaction
*act
)
1456 struct irq_desc
*desc
= irq_to_desc(irq
);
1458 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1461 retval
= irq_chip_pm_get(&desc
->irq_data
);
1465 retval
= __setup_irq(irq
, desc
, act
);
1468 irq_chip_pm_put(&desc
->irq_data
);
1472 EXPORT_SYMBOL_GPL(setup_irq
);
1475 * Internal function to unregister an irqaction - used to free
1476 * regular and special interrupts that are part of the architecture.
1478 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
1480 struct irq_desc
*desc
= irq_to_desc(irq
);
1481 struct irqaction
*action
, **action_ptr
;
1482 unsigned long flags
;
1484 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1489 mutex_lock(&desc
->request_mutex
);
1490 chip_bus_lock(desc
);
1491 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1494 * There can be multiple actions per IRQ descriptor, find the right
1495 * one based on the dev_id:
1497 action_ptr
= &desc
->action
;
1499 action
= *action_ptr
;
1502 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1503 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1504 chip_bus_sync_unlock(desc
);
1505 mutex_unlock(&desc
->request_mutex
);
1509 if (action
->dev_id
== dev_id
)
1511 action_ptr
= &action
->next
;
1514 /* Found it - now remove it from the list of entries: */
1515 *action_ptr
= action
->next
;
1517 irq_pm_remove_action(desc
, action
);
1519 /* If this was the last handler, shut down the IRQ line: */
1520 if (!desc
->action
) {
1521 irq_settings_clr_disable_unlazy(desc
);
1526 /* make sure affinity_hint is cleaned up */
1527 if (WARN_ON_ONCE(desc
->affinity_hint
))
1528 desc
->affinity_hint
= NULL
;
1531 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1533 * Drop bus_lock here so the changes which were done in the chip
1534 * callbacks above are synced out to the irq chips which hang
1535 * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1537 * Aside of that the bus_lock can also be taken from the threaded
1538 * handler in irq_finalize_oneshot() which results in a deadlock
1539 * because synchronize_irq() would wait forever for the thread to
1540 * complete, which is blocked on the bus lock.
1542 * The still held desc->request_mutex() protects against a
1543 * concurrent request_irq() of this irq so the release of resources
1544 * and timing data is properly serialized.
1546 chip_bus_sync_unlock(desc
);
1548 unregister_handler_proc(irq
, action
);
1550 /* Make sure it's not being used on another CPU: */
1551 synchronize_irq(irq
);
1553 #ifdef CONFIG_DEBUG_SHIRQ
1555 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1556 * event to happen even now it's being freed, so let's make sure that
1557 * is so by doing an extra call to the handler ....
1559 * ( We do this after actually deregistering it, to make sure that a
1560 * 'real' IRQ doesn't run in * parallel with our fake. )
1562 if (action
->flags
& IRQF_SHARED
) {
1563 local_irq_save(flags
);
1564 action
->handler(irq
, dev_id
);
1565 local_irq_restore(flags
);
1569 if (action
->thread
) {
1570 kthread_stop(action
->thread
);
1571 put_task_struct(action
->thread
);
1572 if (action
->secondary
&& action
->secondary
->thread
) {
1573 kthread_stop(action
->secondary
->thread
);
1574 put_task_struct(action
->secondary
->thread
);
1578 /* Last action releases resources */
1579 if (!desc
->action
) {
1581 * Reaquire bus lock as irq_release_resources() might
1582 * require it to deallocate resources over the slow bus.
1584 chip_bus_lock(desc
);
1585 irq_release_resources(desc
);
1586 chip_bus_sync_unlock(desc
);
1587 irq_remove_timings(desc
);
1590 mutex_unlock(&desc
->request_mutex
);
1592 irq_chip_pm_put(&desc
->irq_data
);
1593 module_put(desc
->owner
);
1594 kfree(action
->secondary
);
1599 * remove_irq - free an interrupt
1600 * @irq: Interrupt line to free
1601 * @act: irqaction for the interrupt
1603 * Used to remove interrupts statically setup by the early boot process.
1605 void remove_irq(unsigned int irq
, struct irqaction
*act
)
1607 struct irq_desc
*desc
= irq_to_desc(irq
);
1609 if (desc
&& !WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1610 __free_irq(irq
, act
->dev_id
);
1612 EXPORT_SYMBOL_GPL(remove_irq
);
1615 * free_irq - free an interrupt allocated with request_irq
1616 * @irq: Interrupt line to free
1617 * @dev_id: Device identity to free
1619 * Remove an interrupt handler. The handler is removed and if the
1620 * interrupt line is no longer in use by any driver it is disabled.
1621 * On a shared IRQ the caller must ensure the interrupt is disabled
1622 * on the card it drives before calling this function. The function
1623 * does not return until any executing interrupts for this IRQ
1626 * This function must not be called from interrupt context.
1628 * Returns the devname argument passed to request_irq.
1630 const void *free_irq(unsigned int irq
, void *dev_id
)
1632 struct irq_desc
*desc
= irq_to_desc(irq
);
1633 struct irqaction
*action
;
1634 const char *devname
;
1636 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1640 if (WARN_ON(desc
->affinity_notify
))
1641 desc
->affinity_notify
= NULL
;
1644 action
= __free_irq(irq
, dev_id
);
1645 devname
= action
->name
;
1649 EXPORT_SYMBOL(free_irq
);
1652 * request_threaded_irq - allocate an interrupt line
1653 * @irq: Interrupt line to allocate
1654 * @handler: Function to be called when the IRQ occurs.
1655 * Primary handler for threaded interrupts
1656 * If NULL and thread_fn != NULL the default
1657 * primary handler is installed
1658 * @thread_fn: Function called from the irq handler thread
1659 * If NULL, no irq thread is created
1660 * @irqflags: Interrupt type flags
1661 * @devname: An ascii name for the claiming device
1662 * @dev_id: A cookie passed back to the handler function
1664 * This call allocates interrupt resources and enables the
1665 * interrupt line and IRQ handling. From the point this
1666 * call is made your handler function may be invoked. Since
1667 * your handler function must clear any interrupt the board
1668 * raises, you must take care both to initialise your hardware
1669 * and to set up the interrupt handler in the right order.
1671 * If you want to set up a threaded irq handler for your device
1672 * then you need to supply @handler and @thread_fn. @handler is
1673 * still called in hard interrupt context and has to check
1674 * whether the interrupt originates from the device. If yes it
1675 * needs to disable the interrupt on the device and return
1676 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1677 * @thread_fn. This split handler design is necessary to support
1678 * shared interrupts.
1680 * Dev_id must be globally unique. Normally the address of the
1681 * device data structure is used as the cookie. Since the handler
1682 * receives this value it makes sense to use it.
1684 * If your interrupt is shared you must pass a non NULL dev_id
1685 * as this is required when freeing the interrupt.
1689 * IRQF_SHARED Interrupt is shared
1690 * IRQF_TRIGGER_* Specify active edge(s) or level
1693 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
1694 irq_handler_t thread_fn
, unsigned long irqflags
,
1695 const char *devname
, void *dev_id
)
1697 struct irqaction
*action
;
1698 struct irq_desc
*desc
;
1701 if (irq
== IRQ_NOTCONNECTED
)
1705 * Sanity-check: shared interrupts must pass in a real dev-ID,
1706 * otherwise we'll have trouble later trying to figure out
1707 * which interrupt is which (messes up the interrupt freeing
1710 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1711 * it cannot be set along with IRQF_NO_SUSPEND.
1713 if (((irqflags
& IRQF_SHARED
) && !dev_id
) ||
1714 (!(irqflags
& IRQF_SHARED
) && (irqflags
& IRQF_COND_SUSPEND
)) ||
1715 ((irqflags
& IRQF_NO_SUSPEND
) && (irqflags
& IRQF_COND_SUSPEND
)))
1718 desc
= irq_to_desc(irq
);
1722 if (!irq_settings_can_request(desc
) ||
1723 WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1729 handler
= irq_default_primary_handler
;
1732 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1736 action
->handler
= handler
;
1737 action
->thread_fn
= thread_fn
;
1738 action
->flags
= irqflags
;
1739 action
->name
= devname
;
1740 action
->dev_id
= dev_id
;
1742 retval
= irq_chip_pm_get(&desc
->irq_data
);
1748 retval
= __setup_irq(irq
, desc
, action
);
1751 irq_chip_pm_put(&desc
->irq_data
);
1752 kfree(action
->secondary
);
1756 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1757 if (!retval
&& (irqflags
& IRQF_SHARED
)) {
1759 * It's a shared IRQ -- the driver ought to be prepared for it
1760 * to happen immediately, so let's make sure....
1761 * We disable the irq to make sure that a 'real' IRQ doesn't
1762 * run in parallel with our fake.
1764 unsigned long flags
;
1767 local_irq_save(flags
);
1769 handler(irq
, dev_id
);
1771 local_irq_restore(flags
);
1777 EXPORT_SYMBOL(request_threaded_irq
);
1780 * request_any_context_irq - allocate an interrupt line
1781 * @irq: Interrupt line to allocate
1782 * @handler: Function to be called when the IRQ occurs.
1783 * Threaded handler for threaded interrupts.
1784 * @flags: Interrupt type flags
1785 * @name: An ascii name for the claiming device
1786 * @dev_id: A cookie passed back to the handler function
1788 * This call allocates interrupt resources and enables the
1789 * interrupt line and IRQ handling. It selects either a
1790 * hardirq or threaded handling method depending on the
1793 * On failure, it returns a negative value. On success,
1794 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1796 int request_any_context_irq(unsigned int irq
, irq_handler_t handler
,
1797 unsigned long flags
, const char *name
, void *dev_id
)
1799 struct irq_desc
*desc
;
1802 if (irq
== IRQ_NOTCONNECTED
)
1805 desc
= irq_to_desc(irq
);
1809 if (irq_settings_is_nested_thread(desc
)) {
1810 ret
= request_threaded_irq(irq
, NULL
, handler
,
1811 flags
, name
, dev_id
);
1812 return !ret
? IRQC_IS_NESTED
: ret
;
1815 ret
= request_irq(irq
, handler
, flags
, name
, dev_id
);
1816 return !ret
? IRQC_IS_HARDIRQ
: ret
;
1818 EXPORT_SYMBOL_GPL(request_any_context_irq
);
1820 void enable_percpu_irq(unsigned int irq
, unsigned int type
)
1822 unsigned int cpu
= smp_processor_id();
1823 unsigned long flags
;
1824 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1830 * If the trigger type is not specified by the caller, then
1831 * use the default for this interrupt.
1833 type
&= IRQ_TYPE_SENSE_MASK
;
1834 if (type
== IRQ_TYPE_NONE
)
1835 type
= irqd_get_trigger_type(&desc
->irq_data
);
1837 if (type
!= IRQ_TYPE_NONE
) {
1840 ret
= __irq_set_trigger(desc
, type
);
1843 WARN(1, "failed to set type for IRQ%d\n", irq
);
1848 irq_percpu_enable(desc
, cpu
);
1850 irq_put_desc_unlock(desc
, flags
);
1852 EXPORT_SYMBOL_GPL(enable_percpu_irq
);
1855 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1856 * @irq: Linux irq number to check for
1858 * Must be called from a non migratable context. Returns the enable
1859 * state of a per cpu interrupt on the current cpu.
1861 bool irq_percpu_is_enabled(unsigned int irq
)
1863 unsigned int cpu
= smp_processor_id();
1864 struct irq_desc
*desc
;
1865 unsigned long flags
;
1868 desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1872 is_enabled
= cpumask_test_cpu(cpu
, desc
->percpu_enabled
);
1873 irq_put_desc_unlock(desc
, flags
);
1877 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled
);
1879 void disable_percpu_irq(unsigned int irq
)
1881 unsigned int cpu
= smp_processor_id();
1882 unsigned long flags
;
1883 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1888 irq_percpu_disable(desc
, cpu
);
1889 irq_put_desc_unlock(desc
, flags
);
1891 EXPORT_SYMBOL_GPL(disable_percpu_irq
);
1894 * Internal function to unregister a percpu irqaction.
1896 static struct irqaction
*__free_percpu_irq(unsigned int irq
, void __percpu
*dev_id
)
1898 struct irq_desc
*desc
= irq_to_desc(irq
);
1899 struct irqaction
*action
;
1900 unsigned long flags
;
1902 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1907 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1909 action
= desc
->action
;
1910 if (!action
|| action
->percpu_dev_id
!= dev_id
) {
1911 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1915 if (!cpumask_empty(desc
->percpu_enabled
)) {
1916 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1917 irq
, cpumask_first(desc
->percpu_enabled
));
1921 /* Found it - now remove it from the list of entries: */
1922 desc
->action
= NULL
;
1924 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1926 unregister_handler_proc(irq
, action
);
1928 irq_chip_pm_put(&desc
->irq_data
);
1929 module_put(desc
->owner
);
1933 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1938 * remove_percpu_irq - free a per-cpu interrupt
1939 * @irq: Interrupt line to free
1940 * @act: irqaction for the interrupt
1942 * Used to remove interrupts statically setup by the early boot process.
1944 void remove_percpu_irq(unsigned int irq
, struct irqaction
*act
)
1946 struct irq_desc
*desc
= irq_to_desc(irq
);
1948 if (desc
&& irq_settings_is_per_cpu_devid(desc
))
1949 __free_percpu_irq(irq
, act
->percpu_dev_id
);
1953 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1954 * @irq: Interrupt line to free
1955 * @dev_id: Device identity to free
1957 * Remove a percpu interrupt handler. The handler is removed, but
1958 * the interrupt line is not disabled. This must be done on each
1959 * CPU before calling this function. The function does not return
1960 * until any executing interrupts for this IRQ have completed.
1962 * This function must not be called from interrupt context.
1964 void free_percpu_irq(unsigned int irq
, void __percpu
*dev_id
)
1966 struct irq_desc
*desc
= irq_to_desc(irq
);
1968 if (!desc
|| !irq_settings_is_per_cpu_devid(desc
))
1971 chip_bus_lock(desc
);
1972 kfree(__free_percpu_irq(irq
, dev_id
));
1973 chip_bus_sync_unlock(desc
);
1975 EXPORT_SYMBOL_GPL(free_percpu_irq
);
1978 * setup_percpu_irq - setup a per-cpu interrupt
1979 * @irq: Interrupt line to setup
1980 * @act: irqaction for the interrupt
1982 * Used to statically setup per-cpu interrupts in the early boot process.
1984 int setup_percpu_irq(unsigned int irq
, struct irqaction
*act
)
1986 struct irq_desc
*desc
= irq_to_desc(irq
);
1989 if (!desc
|| !irq_settings_is_per_cpu_devid(desc
))
1992 retval
= irq_chip_pm_get(&desc
->irq_data
);
1996 retval
= __setup_irq(irq
, desc
, act
);
1999 irq_chip_pm_put(&desc
->irq_data
);
2005 * __request_percpu_irq - allocate a percpu interrupt line
2006 * @irq: Interrupt line to allocate
2007 * @handler: Function to be called when the IRQ occurs.
2008 * @flags: Interrupt type flags (IRQF_TIMER only)
2009 * @devname: An ascii name for the claiming device
2010 * @dev_id: A percpu cookie passed back to the handler function
2012 * This call allocates interrupt resources and enables the
2013 * interrupt on the local CPU. If the interrupt is supposed to be
2014 * enabled on other CPUs, it has to be done on each CPU using
2015 * enable_percpu_irq().
2017 * Dev_id must be globally unique. It is a per-cpu variable, and
2018 * the handler gets called with the interrupted CPU's instance of
2021 int __request_percpu_irq(unsigned int irq
, irq_handler_t handler
,
2022 unsigned long flags
, const char *devname
,
2023 void __percpu
*dev_id
)
2025 struct irqaction
*action
;
2026 struct irq_desc
*desc
;
2032 desc
= irq_to_desc(irq
);
2033 if (!desc
|| !irq_settings_can_request(desc
) ||
2034 !irq_settings_is_per_cpu_devid(desc
))
2037 if (flags
&& flags
!= IRQF_TIMER
)
2040 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
2044 action
->handler
= handler
;
2045 action
->flags
= flags
| IRQF_PERCPU
| IRQF_NO_SUSPEND
;
2046 action
->name
= devname
;
2047 action
->percpu_dev_id
= dev_id
;
2049 retval
= irq_chip_pm_get(&desc
->irq_data
);
2055 retval
= __setup_irq(irq
, desc
, action
);
2058 irq_chip_pm_put(&desc
->irq_data
);
2064 EXPORT_SYMBOL_GPL(__request_percpu_irq
);
2067 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2068 * @irq: Interrupt line that is forwarded to a VM
2069 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2070 * @state: a pointer to a boolean where the state is to be storeed
2072 * This call snapshots the internal irqchip state of an
2073 * interrupt, returning into @state the bit corresponding to
2076 * This function should be called with preemption disabled if the
2077 * interrupt controller has per-cpu registers.
2079 int irq_get_irqchip_state(unsigned int irq
, enum irqchip_irq_state which
,
2082 struct irq_desc
*desc
;
2083 struct irq_data
*data
;
2084 struct irq_chip
*chip
;
2085 unsigned long flags
;
2088 desc
= irq_get_desc_buslock(irq
, &flags
, 0);
2092 data
= irq_desc_get_irq_data(desc
);
2095 chip
= irq_data_get_irq_chip(data
);
2096 if (chip
->irq_get_irqchip_state
)
2098 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2099 data
= data
->parent_data
;
2106 err
= chip
->irq_get_irqchip_state(data
, which
, state
);
2108 irq_put_desc_busunlock(desc
, flags
);
2111 EXPORT_SYMBOL_GPL(irq_get_irqchip_state
);
2114 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2115 * @irq: Interrupt line that is forwarded to a VM
2116 * @which: State to be restored (one of IRQCHIP_STATE_*)
2117 * @val: Value corresponding to @which
2119 * This call sets the internal irqchip state of an interrupt,
2120 * depending on the value of @which.
2122 * This function should be called with preemption disabled if the
2123 * interrupt controller has per-cpu registers.
2125 int irq_set_irqchip_state(unsigned int irq
, enum irqchip_irq_state which
,
2128 struct irq_desc
*desc
;
2129 struct irq_data
*data
;
2130 struct irq_chip
*chip
;
2131 unsigned long flags
;
2134 desc
= irq_get_desc_buslock(irq
, &flags
, 0);
2138 data
= irq_desc_get_irq_data(desc
);
2141 chip
= irq_data_get_irq_chip(data
);
2142 if (chip
->irq_set_irqchip_state
)
2144 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2145 data
= data
->parent_data
;
2152 err
= chip
->irq_set_irqchip_state(data
, which
, val
);
2154 irq_put_desc_busunlock(desc
, flags
);
2157 EXPORT_SYMBOL_GPL(irq_set_irqchip_state
);