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/irqdomain.h>
18 #include <linux/slab.h>
19 #include <linux/sched.h>
20 #include <linux/sched/rt.h>
21 #include <linux/sched/task.h>
22 #include <uapi/linux/sched/types.h>
23 #include <linux/task_work.h>
25 #include "internals.h"
27 #ifdef CONFIG_IRQ_FORCED_THREADING
28 __read_mostly
bool force_irqthreads
= IS_ENABLED(CONFIG_IRQ_FORCED_THREADING_DEFAULT
);
30 static int __init
setup_forced_irqthreads(char *arg
)
32 force_irqthreads
= true;
35 static int __init
setup_no_irqthreads(char *arg
)
37 force_irqthreads
= false;
40 early_param("threadirqs", setup_forced_irqthreads
);
41 early_param("nothreadirqs", setup_no_irqthreads
);
44 static void __synchronize_hardirq(struct irq_desc
*desc
)
52 * Wait until we're out of the critical section. This might
53 * give the wrong answer due to the lack of memory barriers.
55 while (irqd_irq_inprogress(&desc
->irq_data
))
58 /* Ok, that indicated we're done: double-check carefully. */
59 raw_spin_lock_irqsave(&desc
->lock
, flags
);
60 inprogress
= irqd_irq_inprogress(&desc
->irq_data
);
61 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
63 /* Oops, that failed? */
68 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
69 * @irq: interrupt number to wait for
71 * This function waits for any pending hard IRQ handlers for this
72 * interrupt to complete before returning. If you use this
73 * function while holding a resource the IRQ handler may need you
74 * will deadlock. It does not take associated threaded handlers
77 * Do not use this for shutdown scenarios where you must be sure
78 * that all parts (hardirq and threaded handler) have completed.
80 * Returns: false if a threaded handler is active.
82 * This function may be called - with care - from IRQ context.
84 bool synchronize_hardirq(unsigned int irq
)
86 struct irq_desc
*desc
= irq_to_desc(irq
);
89 __synchronize_hardirq(desc
);
90 return !atomic_read(&desc
->threads_active
);
95 EXPORT_SYMBOL(synchronize_hardirq
);
98 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
99 * @irq: interrupt number to wait for
101 * This function waits for any pending IRQ handlers for this interrupt
102 * to complete before returning. If you use this function while
103 * holding a resource the IRQ handler may need you will deadlock.
105 * This function may be called - with care - from IRQ context.
107 void synchronize_irq(unsigned int irq
)
109 struct irq_desc
*desc
= irq_to_desc(irq
);
112 __synchronize_hardirq(desc
);
114 * We made sure that no hardirq handler is
115 * running. Now verify that no threaded handlers are
118 wait_event(desc
->wait_for_threads
,
119 !atomic_read(&desc
->threads_active
));
122 EXPORT_SYMBOL(synchronize_irq
);
125 cpumask_var_t irq_default_affinity
;
127 static bool __irq_can_set_affinity(struct irq_desc
*desc
)
129 if (!desc
|| !irqd_can_balance(&desc
->irq_data
) ||
130 !desc
->irq_data
.chip
|| !desc
->irq_data
.chip
->irq_set_affinity
)
136 * irq_can_set_affinity - Check if the affinity of a given irq can be set
137 * @irq: Interrupt to check
140 int irq_can_set_affinity(unsigned int irq
)
142 return __irq_can_set_affinity(irq_to_desc(irq
));
146 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
147 * @irq: Interrupt to check
149 * Like irq_can_set_affinity() above, but additionally checks for the
150 * AFFINITY_MANAGED flag.
152 bool irq_can_set_affinity_usr(unsigned int irq
)
154 struct irq_desc
*desc
= irq_to_desc(irq
);
156 return __irq_can_set_affinity(desc
) &&
157 !irqd_affinity_is_managed(&desc
->irq_data
);
161 * irq_set_thread_affinity - Notify irq threads to adjust affinity
162 * @desc: irq descriptor which has affitnity changed
164 * We just set IRQTF_AFFINITY and delegate the affinity setting
165 * to the interrupt thread itself. We can not call
166 * set_cpus_allowed_ptr() here as we hold desc->lock and this
167 * code can be called from hard interrupt context.
169 void irq_set_thread_affinity(struct irq_desc
*desc
)
171 struct irqaction
*action
;
173 for_each_action_of_desc(desc
, action
)
175 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
178 static void irq_validate_effective_affinity(struct irq_data
*data
)
180 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
181 const struct cpumask
*m
= irq_data_get_effective_affinity_mask(data
);
182 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
184 if (!cpumask_empty(m
))
186 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
187 chip
->name
, data
->irq
);
191 int irq_do_set_affinity(struct irq_data
*data
, const struct cpumask
*mask
,
194 struct irq_desc
*desc
= irq_data_to_desc(data
);
195 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
198 if (!chip
|| !chip
->irq_set_affinity
)
201 ret
= chip
->irq_set_affinity(data
, mask
, force
);
203 case IRQ_SET_MASK_OK
:
204 case IRQ_SET_MASK_OK_DONE
:
205 cpumask_copy(desc
->irq_common_data
.affinity
, mask
);
206 case IRQ_SET_MASK_OK_NOCOPY
:
207 irq_validate_effective_affinity(data
);
208 irq_set_thread_affinity(desc
);
215 #ifdef CONFIG_GENERIC_PENDING_IRQ
216 static inline int irq_set_affinity_pending(struct irq_data
*data
,
217 const struct cpumask
*dest
)
219 struct irq_desc
*desc
= irq_data_to_desc(data
);
221 irqd_set_move_pending(data
);
222 irq_copy_pending(desc
, dest
);
226 static inline int irq_set_affinity_pending(struct irq_data
*data
,
227 const struct cpumask
*dest
)
233 static int irq_try_set_affinity(struct irq_data
*data
,
234 const struct cpumask
*dest
, bool force
)
236 int ret
= irq_do_set_affinity(data
, dest
, force
);
239 * In case that the underlying vector management is busy and the
240 * architecture supports the generic pending mechanism then utilize
241 * this to avoid returning an error to user space.
243 if (ret
== -EBUSY
&& !force
)
244 ret
= irq_set_affinity_pending(data
, dest
);
248 int irq_set_affinity_locked(struct irq_data
*data
, const struct cpumask
*mask
,
251 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
252 struct irq_desc
*desc
= irq_data_to_desc(data
);
255 if (!chip
|| !chip
->irq_set_affinity
)
258 if (irq_can_move_pcntxt(data
) && !irqd_is_setaffinity_pending(data
)) {
259 ret
= irq_try_set_affinity(data
, mask
, force
);
261 irqd_set_move_pending(data
);
262 irq_copy_pending(desc
, mask
);
265 if (desc
->affinity_notify
) {
266 kref_get(&desc
->affinity_notify
->kref
);
267 schedule_work(&desc
->affinity_notify
->work
);
269 irqd_set(data
, IRQD_AFFINITY_SET
);
274 int __irq_set_affinity(unsigned int irq
, const struct cpumask
*mask
, bool force
)
276 struct irq_desc
*desc
= irq_to_desc(irq
);
283 raw_spin_lock_irqsave(&desc
->lock
, flags
);
284 ret
= irq_set_affinity_locked(irq_desc_get_irq_data(desc
), mask
, force
);
285 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
289 int irq_set_affinity_hint(unsigned int irq
, const struct cpumask
*m
)
292 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
296 desc
->affinity_hint
= m
;
297 irq_put_desc_unlock(desc
, flags
);
298 /* set the initial affinity to prevent every interrupt being on CPU0 */
300 __irq_set_affinity(irq
, m
, false);
303 EXPORT_SYMBOL_GPL(irq_set_affinity_hint
);
305 static void irq_affinity_notify(struct work_struct
*work
)
307 struct irq_affinity_notify
*notify
=
308 container_of(work
, struct irq_affinity_notify
, work
);
309 struct irq_desc
*desc
= irq_to_desc(notify
->irq
);
310 cpumask_var_t cpumask
;
313 if (!desc
|| !alloc_cpumask_var(&cpumask
, GFP_KERNEL
))
316 raw_spin_lock_irqsave(&desc
->lock
, flags
);
317 if (irq_move_pending(&desc
->irq_data
))
318 irq_get_pending(cpumask
, desc
);
320 cpumask_copy(cpumask
, desc
->irq_common_data
.affinity
);
321 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
323 notify
->notify(notify
, cpumask
);
325 free_cpumask_var(cpumask
);
327 kref_put(¬ify
->kref
, notify
->release
);
331 * irq_set_affinity_notifier - control notification of IRQ affinity changes
332 * @irq: Interrupt for which to enable/disable notification
333 * @notify: Context for notification, or %NULL to disable
334 * notification. Function pointers must be initialised;
335 * the other fields will be initialised by this function.
337 * Must be called in process context. Notification may only be enabled
338 * after the IRQ is allocated and must be disabled before the IRQ is
339 * freed using free_irq().
342 irq_set_affinity_notifier(unsigned int irq
, struct irq_affinity_notify
*notify
)
344 struct irq_desc
*desc
= irq_to_desc(irq
);
345 struct irq_affinity_notify
*old_notify
;
348 /* The release function is promised process context */
354 /* Complete initialisation of *notify */
357 kref_init(¬ify
->kref
);
358 INIT_WORK(¬ify
->work
, irq_affinity_notify
);
361 raw_spin_lock_irqsave(&desc
->lock
, flags
);
362 old_notify
= desc
->affinity_notify
;
363 desc
->affinity_notify
= notify
;
364 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
367 cancel_work_sync(&old_notify
->work
);
368 kref_put(&old_notify
->kref
, old_notify
->release
);
373 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier
);
375 #ifndef CONFIG_AUTO_IRQ_AFFINITY
377 * Generic version of the affinity autoselector.
379 int irq_setup_affinity(struct irq_desc
*desc
)
381 struct cpumask
*set
= irq_default_affinity
;
382 int ret
, node
= irq_desc_get_node(desc
);
383 static DEFINE_RAW_SPINLOCK(mask_lock
);
384 static struct cpumask mask
;
386 /* Excludes PER_CPU and NO_BALANCE interrupts */
387 if (!__irq_can_set_affinity(desc
))
390 raw_spin_lock(&mask_lock
);
392 * Preserve the managed affinity setting and a userspace affinity
393 * setup, but make sure that one of the targets is online.
395 if (irqd_affinity_is_managed(&desc
->irq_data
) ||
396 irqd_has_set(&desc
->irq_data
, IRQD_AFFINITY_SET
)) {
397 if (cpumask_intersects(desc
->irq_common_data
.affinity
,
399 set
= desc
->irq_common_data
.affinity
;
401 irqd_clear(&desc
->irq_data
, IRQD_AFFINITY_SET
);
404 cpumask_and(&mask
, cpu_online_mask
, set
);
405 if (cpumask_empty(&mask
))
406 cpumask_copy(&mask
, cpu_online_mask
);
408 if (node
!= NUMA_NO_NODE
) {
409 const struct cpumask
*nodemask
= cpumask_of_node(node
);
411 /* make sure at least one of the cpus in nodemask is online */
412 if (cpumask_intersects(&mask
, nodemask
))
413 cpumask_and(&mask
, &mask
, nodemask
);
415 ret
= irq_do_set_affinity(&desc
->irq_data
, &mask
, false);
416 raw_spin_unlock(&mask_lock
);
420 /* Wrapper for ALPHA specific affinity selector magic */
421 int irq_setup_affinity(struct irq_desc
*desc
)
423 return irq_select_affinity(irq_desc_get_irq(desc
));
428 * Called when a bogus affinity is set via /proc/irq
430 int irq_select_affinity_usr(unsigned int irq
)
432 struct irq_desc
*desc
= irq_to_desc(irq
);
436 raw_spin_lock_irqsave(&desc
->lock
, flags
);
437 ret
= irq_setup_affinity(desc
);
438 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
444 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
445 * @irq: interrupt number to set affinity
446 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
447 * specific data for percpu_devid interrupts
449 * This function uses the vCPU specific data to set the vCPU
450 * affinity for an irq. The vCPU specific data is passed from
451 * outside, such as KVM. One example code path is as below:
452 * KVM -> IOMMU -> irq_set_vcpu_affinity().
454 int irq_set_vcpu_affinity(unsigned int irq
, void *vcpu_info
)
457 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
458 struct irq_data
*data
;
459 struct irq_chip
*chip
;
465 data
= irq_desc_get_irq_data(desc
);
467 chip
= irq_data_get_irq_chip(data
);
468 if (chip
&& chip
->irq_set_vcpu_affinity
)
470 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
471 data
= data
->parent_data
;
478 ret
= chip
->irq_set_vcpu_affinity(data
, vcpu_info
);
479 irq_put_desc_unlock(desc
, flags
);
483 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity
);
485 void __disable_irq(struct irq_desc
*desc
)
491 static int __disable_irq_nosync(unsigned int irq
)
494 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
499 irq_put_desc_busunlock(desc
, flags
);
504 * disable_irq_nosync - disable an irq without waiting
505 * @irq: Interrupt to disable
507 * Disable the selected interrupt line. Disables and Enables are
509 * Unlike disable_irq(), this function does not ensure existing
510 * instances of the IRQ handler have completed before returning.
512 * This function may be called from IRQ context.
514 void disable_irq_nosync(unsigned int irq
)
516 __disable_irq_nosync(irq
);
518 EXPORT_SYMBOL(disable_irq_nosync
);
521 * disable_irq - disable an irq and wait for completion
522 * @irq: Interrupt to disable
524 * Disable the selected interrupt line. Enables and Disables are
526 * This function waits for any pending IRQ handlers for this interrupt
527 * to complete before returning. If you use this function while
528 * holding a resource the IRQ handler may need you will deadlock.
530 * This function may be called - with care - from IRQ context.
532 void disable_irq(unsigned int irq
)
534 if (!__disable_irq_nosync(irq
))
535 synchronize_irq(irq
);
537 EXPORT_SYMBOL(disable_irq
);
540 * disable_hardirq - disables an irq and waits for hardirq completion
541 * @irq: Interrupt to disable
543 * Disable the selected interrupt line. Enables and Disables are
545 * This function waits for any pending hard IRQ handlers for this
546 * interrupt to complete before returning. If you use this function while
547 * holding a resource the hard IRQ handler may need you will deadlock.
549 * When used to optimistically disable an interrupt from atomic context
550 * the return value must be checked.
552 * Returns: false if a threaded handler is active.
554 * This function may be called - with care - from IRQ context.
556 bool disable_hardirq(unsigned int irq
)
558 if (!__disable_irq_nosync(irq
))
559 return synchronize_hardirq(irq
);
563 EXPORT_SYMBOL_GPL(disable_hardirq
);
565 void __enable_irq(struct irq_desc
*desc
)
567 switch (desc
->depth
) {
570 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n",
571 irq_desc_get_irq(desc
));
574 if (desc
->istate
& IRQS_SUSPENDED
)
576 /* Prevent probing on this irq: */
577 irq_settings_set_noprobe(desc
);
579 * Call irq_startup() not irq_enable() here because the
580 * interrupt might be marked NOAUTOEN. So irq_startup()
581 * needs to be invoked when it gets enabled the first
582 * time. If it was already started up, then irq_startup()
583 * will invoke irq_enable() under the hood.
585 irq_startup(desc
, IRQ_RESEND
, IRQ_START_FORCE
);
594 * enable_irq - enable handling of an irq
595 * @irq: Interrupt to enable
597 * Undoes the effect of one call to disable_irq(). If this
598 * matches the last disable, processing of interrupts on this
599 * IRQ line is re-enabled.
601 * This function may be called from IRQ context only when
602 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
604 void enable_irq(unsigned int irq
)
607 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
611 if (WARN(!desc
->irq_data
.chip
,
612 KERN_ERR
"enable_irq before setup/request_irq: irq %u\n", irq
))
617 irq_put_desc_busunlock(desc
, flags
);
619 EXPORT_SYMBOL(enable_irq
);
621 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
623 struct irq_desc
*desc
= irq_to_desc(irq
);
626 if (irq_desc_get_chip(desc
)->flags
& IRQCHIP_SKIP_SET_WAKE
)
629 if (desc
->irq_data
.chip
->irq_set_wake
)
630 ret
= desc
->irq_data
.chip
->irq_set_wake(&desc
->irq_data
, on
);
636 * irq_set_irq_wake - control irq power management wakeup
637 * @irq: interrupt to control
638 * @on: enable/disable power management wakeup
640 * Enable/disable power management wakeup mode, which is
641 * disabled by default. Enables and disables must match,
642 * just as they match for non-wakeup mode support.
644 * Wakeup mode lets this IRQ wake the system from sleep
645 * states like "suspend to RAM".
647 int irq_set_irq_wake(unsigned int irq
, unsigned int on
)
650 struct irq_desc
*desc
= irq_get_desc_buslock(irq
, &flags
, IRQ_GET_DESC_CHECK_GLOBAL
);
656 /* wakeup-capable irqs can be shared between drivers that
657 * don't need to have the same sleep mode behaviors.
660 if (desc
->wake_depth
++ == 0) {
661 ret
= set_irq_wake_real(irq
, on
);
663 desc
->wake_depth
= 0;
665 irqd_set(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
668 if (desc
->wake_depth
== 0) {
669 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
670 } else if (--desc
->wake_depth
== 0) {
671 ret
= set_irq_wake_real(irq
, on
);
673 desc
->wake_depth
= 1;
675 irqd_clear(&desc
->irq_data
, IRQD_WAKEUP_STATE
);
678 irq_put_desc_busunlock(desc
, flags
);
681 EXPORT_SYMBOL(irq_set_irq_wake
);
684 * Internal function that tells the architecture code whether a
685 * particular irq has been exclusively allocated or is available
688 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
691 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
697 if (irq_settings_can_request(desc
)) {
699 irqflags
& desc
->action
->flags
& IRQF_SHARED
)
702 irq_put_desc_unlock(desc
, flags
);
706 int __irq_set_trigger(struct irq_desc
*desc
, unsigned long flags
)
708 struct irq_chip
*chip
= desc
->irq_data
.chip
;
711 if (!chip
|| !chip
->irq_set_type
) {
713 * IRQF_TRIGGER_* but the PIC does not support multiple
716 pr_debug("No set_type function for IRQ %d (%s)\n",
717 irq_desc_get_irq(desc
),
718 chip
? (chip
->name
? : "unknown") : "unknown");
722 if (chip
->flags
& IRQCHIP_SET_TYPE_MASKED
) {
723 if (!irqd_irq_masked(&desc
->irq_data
))
725 if (!irqd_irq_disabled(&desc
->irq_data
))
729 /* Mask all flags except trigger mode */
730 flags
&= IRQ_TYPE_SENSE_MASK
;
731 ret
= chip
->irq_set_type(&desc
->irq_data
, flags
);
734 case IRQ_SET_MASK_OK
:
735 case IRQ_SET_MASK_OK_DONE
:
736 irqd_clear(&desc
->irq_data
, IRQD_TRIGGER_MASK
);
737 irqd_set(&desc
->irq_data
, flags
);
739 case IRQ_SET_MASK_OK_NOCOPY
:
740 flags
= irqd_get_trigger_type(&desc
->irq_data
);
741 irq_settings_set_trigger_mask(desc
, flags
);
742 irqd_clear(&desc
->irq_data
, IRQD_LEVEL
);
743 irq_settings_clr_level(desc
);
744 if (flags
& IRQ_TYPE_LEVEL_MASK
) {
745 irq_settings_set_level(desc
);
746 irqd_set(&desc
->irq_data
, IRQD_LEVEL
);
752 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
753 flags
, irq_desc_get_irq(desc
), chip
->irq_set_type
);
760 #ifdef CONFIG_HARDIRQS_SW_RESEND
761 int irq_set_parent(int irq
, int parent_irq
)
764 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, 0);
769 desc
->parent_irq
= parent_irq
;
771 irq_put_desc_unlock(desc
, flags
);
774 EXPORT_SYMBOL_GPL(irq_set_parent
);
778 * Default primary interrupt handler for threaded interrupts. Is
779 * assigned as primary handler when request_threaded_irq is called
780 * with handler == NULL. Useful for oneshot interrupts.
782 static irqreturn_t
irq_default_primary_handler(int irq
, void *dev_id
)
784 return IRQ_WAKE_THREAD
;
788 * Primary handler for nested threaded interrupts. Should never be
791 static irqreturn_t
irq_nested_primary_handler(int irq
, void *dev_id
)
793 WARN(1, "Primary handler called for nested irq %d\n", irq
);
797 static irqreturn_t
irq_forced_secondary_handler(int irq
, void *dev_id
)
799 WARN(1, "Secondary action handler called for irq %d\n", irq
);
803 static int irq_wait_for_interrupt(struct irqaction
*action
)
805 set_current_state(TASK_INTERRUPTIBLE
);
807 while (!kthread_should_stop()) {
809 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
810 &action
->thread_flags
)) {
811 __set_current_state(TASK_RUNNING
);
815 set_current_state(TASK_INTERRUPTIBLE
);
817 __set_current_state(TASK_RUNNING
);
822 * Oneshot interrupts keep the irq line masked until the threaded
823 * handler finished. unmask if the interrupt has not been disabled and
826 static void irq_finalize_oneshot(struct irq_desc
*desc
,
827 struct irqaction
*action
)
829 if (!(desc
->istate
& IRQS_ONESHOT
) ||
830 action
->handler
== irq_forced_secondary_handler
)
834 raw_spin_lock_irq(&desc
->lock
);
837 * Implausible though it may be we need to protect us against
838 * the following scenario:
840 * The thread is faster done than the hard interrupt handler
841 * on the other CPU. If we unmask the irq line then the
842 * interrupt can come in again and masks the line, leaves due
843 * to IRQS_INPROGRESS and the irq line is masked forever.
845 * This also serializes the state of shared oneshot handlers
846 * versus "desc->threads_onehsot |= action->thread_mask;" in
847 * irq_wake_thread(). See the comment there which explains the
850 if (unlikely(irqd_irq_inprogress(&desc
->irq_data
))) {
851 raw_spin_unlock_irq(&desc
->lock
);
852 chip_bus_sync_unlock(desc
);
858 * Now check again, whether the thread should run. Otherwise
859 * we would clear the threads_oneshot bit of this thread which
862 if (test_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
865 desc
->threads_oneshot
&= ~action
->thread_mask
;
867 if (!desc
->threads_oneshot
&& !irqd_irq_disabled(&desc
->irq_data
) &&
868 irqd_irq_masked(&desc
->irq_data
))
869 unmask_threaded_irq(desc
);
872 raw_spin_unlock_irq(&desc
->lock
);
873 chip_bus_sync_unlock(desc
);
878 * Check whether we need to change the affinity of the interrupt thread.
881 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
)
886 if (!test_and_clear_bit(IRQTF_AFFINITY
, &action
->thread_flags
))
890 * In case we are out of memory we set IRQTF_AFFINITY again and
891 * try again next time
893 if (!alloc_cpumask_var(&mask
, GFP_KERNEL
)) {
894 set_bit(IRQTF_AFFINITY
, &action
->thread_flags
);
898 raw_spin_lock_irq(&desc
->lock
);
900 * This code is triggered unconditionally. Check the affinity
901 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
903 if (cpumask_available(desc
->irq_common_data
.affinity
))
904 cpumask_copy(mask
, desc
->irq_common_data
.affinity
);
907 raw_spin_unlock_irq(&desc
->lock
);
910 set_cpus_allowed_ptr(current
, mask
);
911 free_cpumask_var(mask
);
915 irq_thread_check_affinity(struct irq_desc
*desc
, struct irqaction
*action
) { }
919 * Interrupts which are not explicitely requested as threaded
920 * interrupts rely on the implicit bh/preempt disable of the hard irq
921 * context. So we need to disable bh here to avoid deadlocks and other
925 irq_forced_thread_fn(struct irq_desc
*desc
, struct irqaction
*action
)
930 ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
931 if (ret
== IRQ_HANDLED
)
932 atomic_inc(&desc
->threads_handled
);
934 irq_finalize_oneshot(desc
, action
);
940 * Interrupts explicitly requested as threaded interrupts want to be
941 * preemtible - many of them need to sleep and wait for slow busses to
944 static irqreturn_t
irq_thread_fn(struct irq_desc
*desc
,
945 struct irqaction
*action
)
949 ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
950 if (ret
== IRQ_HANDLED
)
951 atomic_inc(&desc
->threads_handled
);
953 irq_finalize_oneshot(desc
, action
);
957 static void wake_threads_waitq(struct irq_desc
*desc
)
959 if (atomic_dec_and_test(&desc
->threads_active
))
960 wake_up(&desc
->wait_for_threads
);
963 static void irq_thread_dtor(struct callback_head
*unused
)
965 struct task_struct
*tsk
= current
;
966 struct irq_desc
*desc
;
967 struct irqaction
*action
;
969 if (WARN_ON_ONCE(!(current
->flags
& PF_EXITING
)))
972 action
= kthread_data(tsk
);
974 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
975 tsk
->comm
, tsk
->pid
, action
->irq
);
978 desc
= irq_to_desc(action
->irq
);
980 * If IRQTF_RUNTHREAD is set, we need to decrement
981 * desc->threads_active and wake possible waiters.
983 if (test_and_clear_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
))
984 wake_threads_waitq(desc
);
986 /* Prevent a stale desc->threads_oneshot */
987 irq_finalize_oneshot(desc
, action
);
990 static void irq_wake_secondary(struct irq_desc
*desc
, struct irqaction
*action
)
992 struct irqaction
*secondary
= action
->secondary
;
994 if (WARN_ON_ONCE(!secondary
))
997 raw_spin_lock_irq(&desc
->lock
);
998 __irq_wake_thread(desc
, secondary
);
999 raw_spin_unlock_irq(&desc
->lock
);
1003 * Interrupt handler thread
1005 static int irq_thread(void *data
)
1007 struct callback_head on_exit_work
;
1008 struct irqaction
*action
= data
;
1009 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
1010 irqreturn_t (*handler_fn
)(struct irq_desc
*desc
,
1011 struct irqaction
*action
);
1013 if (force_irqthreads
&& test_bit(IRQTF_FORCED_THREAD
,
1014 &action
->thread_flags
))
1015 handler_fn
= irq_forced_thread_fn
;
1017 handler_fn
= irq_thread_fn
;
1019 init_task_work(&on_exit_work
, irq_thread_dtor
);
1020 task_work_add(current
, &on_exit_work
, false);
1022 irq_thread_check_affinity(desc
, action
);
1024 while (!irq_wait_for_interrupt(action
)) {
1025 irqreturn_t action_ret
;
1027 irq_thread_check_affinity(desc
, action
);
1029 action_ret
= handler_fn(desc
, action
);
1030 if (action_ret
== IRQ_WAKE_THREAD
)
1031 irq_wake_secondary(desc
, action
);
1033 wake_threads_waitq(desc
);
1037 * This is the regular exit path. __free_irq() is stopping the
1038 * thread via kthread_stop() after calling
1039 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
1040 * oneshot mask bit can be set. We cannot verify that as we
1041 * cannot touch the oneshot mask at this point anymore as
1042 * __setup_irq() might have given out currents thread_mask
1045 task_work_cancel(current
, irq_thread_dtor
);
1050 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1051 * @irq: Interrupt line
1052 * @dev_id: Device identity for which the thread should be woken
1055 void irq_wake_thread(unsigned int irq
, void *dev_id
)
1057 struct irq_desc
*desc
= irq_to_desc(irq
);
1058 struct irqaction
*action
;
1059 unsigned long flags
;
1061 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1064 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1065 for_each_action_of_desc(desc
, action
) {
1066 if (action
->dev_id
== dev_id
) {
1068 __irq_wake_thread(desc
, action
);
1072 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1074 EXPORT_SYMBOL_GPL(irq_wake_thread
);
1076 static int irq_setup_forced_threading(struct irqaction
*new)
1078 if (!force_irqthreads
)
1080 if (new->flags
& (IRQF_NO_THREAD
| IRQF_PERCPU
| IRQF_ONESHOT
))
1084 * No further action required for interrupts which are requested as
1085 * threaded interrupts already
1087 if (new->handler
== irq_default_primary_handler
)
1090 new->flags
|= IRQF_ONESHOT
;
1093 * Handle the case where we have a real primary handler and a
1094 * thread handler. We force thread them as well by creating a
1097 if (new->handler
&& new->thread_fn
) {
1098 /* Allocate the secondary action */
1099 new->secondary
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1100 if (!new->secondary
)
1102 new->secondary
->handler
= irq_forced_secondary_handler
;
1103 new->secondary
->thread_fn
= new->thread_fn
;
1104 new->secondary
->dev_id
= new->dev_id
;
1105 new->secondary
->irq
= new->irq
;
1106 new->secondary
->name
= new->name
;
1108 /* Deal with the primary handler */
1109 set_bit(IRQTF_FORCED_THREAD
, &new->thread_flags
);
1110 new->thread_fn
= new->handler
;
1111 new->handler
= irq_default_primary_handler
;
1115 static int irq_request_resources(struct irq_desc
*desc
)
1117 struct irq_data
*d
= &desc
->irq_data
;
1118 struct irq_chip
*c
= d
->chip
;
1120 return c
->irq_request_resources
? c
->irq_request_resources(d
) : 0;
1123 static void irq_release_resources(struct irq_desc
*desc
)
1125 struct irq_data
*d
= &desc
->irq_data
;
1126 struct irq_chip
*c
= d
->chip
;
1128 if (c
->irq_release_resources
)
1129 c
->irq_release_resources(d
);
1133 setup_irq_thread(struct irqaction
*new, unsigned int irq
, bool secondary
)
1135 struct task_struct
*t
;
1136 struct sched_param param
= {
1137 .sched_priority
= MAX_USER_RT_PRIO
/2,
1141 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
1144 t
= kthread_create(irq_thread
, new, "irq/%d-s-%s", irq
,
1146 param
.sched_priority
-= 1;
1152 sched_setscheduler_nocheck(t
, SCHED_FIFO
, ¶m
);
1155 * We keep the reference to the task struct even if
1156 * the thread dies to avoid that the interrupt code
1157 * references an already freed task_struct.
1162 * Tell the thread to set its affinity. This is
1163 * important for shared interrupt handlers as we do
1164 * not invoke setup_affinity() for the secondary
1165 * handlers as everything is already set up. Even for
1166 * interrupts marked with IRQF_NO_BALANCE this is
1167 * correct as we want the thread to move to the cpu(s)
1168 * on which the requesting code placed the interrupt.
1170 set_bit(IRQTF_AFFINITY
, &new->thread_flags
);
1175 * Internal function to register an irqaction - typically used to
1176 * allocate special interrupts that are part of the architecture.
1180 * desc->request_mutex Provides serialization against a concurrent free_irq()
1181 * chip_bus_lock Provides serialization for slow bus operations
1182 * desc->lock Provides serialization against hard interrupts
1184 * chip_bus_lock and desc->lock are sufficient for all other management and
1185 * interrupt related functions. desc->request_mutex solely serializes
1186 * request/free_irq().
1189 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
1191 struct irqaction
*old
, **old_ptr
;
1192 unsigned long flags
, thread_mask
= 0;
1193 int ret
, nested
, shared
= 0;
1198 if (desc
->irq_data
.chip
== &no_irq_chip
)
1200 if (!try_module_get(desc
->owner
))
1206 * If the trigger type is not specified by the caller,
1207 * then use the default for this interrupt.
1209 if (!(new->flags
& IRQF_TRIGGER_MASK
))
1210 new->flags
|= irqd_get_trigger_type(&desc
->irq_data
);
1213 * Check whether the interrupt nests into another interrupt
1216 nested
= irq_settings_is_nested_thread(desc
);
1218 if (!new->thread_fn
) {
1223 * Replace the primary handler which was provided from
1224 * the driver for non nested interrupt handling by the
1225 * dummy function which warns when called.
1227 new->handler
= irq_nested_primary_handler
;
1229 if (irq_settings_can_thread(desc
)) {
1230 ret
= irq_setup_forced_threading(new);
1237 * Create a handler thread when a thread function is supplied
1238 * and the interrupt does not nest into another interrupt
1241 if (new->thread_fn
&& !nested
) {
1242 ret
= setup_irq_thread(new, irq
, false);
1245 if (new->secondary
) {
1246 ret
= setup_irq_thread(new->secondary
, irq
, true);
1253 * Drivers are often written to work w/o knowledge about the
1254 * underlying irq chip implementation, so a request for a
1255 * threaded irq without a primary hard irq context handler
1256 * requires the ONESHOT flag to be set. Some irq chips like
1257 * MSI based interrupts are per se one shot safe. Check the
1258 * chip flags, so we can avoid the unmask dance at the end of
1259 * the threaded handler for those.
1261 if (desc
->irq_data
.chip
->flags
& IRQCHIP_ONESHOT_SAFE
)
1262 new->flags
&= ~IRQF_ONESHOT
;
1265 * Protects against a concurrent __free_irq() call which might wait
1266 * for synchronize_irq() to complete without holding the optional
1267 * chip bus lock and desc->lock.
1269 mutex_lock(&desc
->request_mutex
);
1272 * Acquire bus lock as the irq_request_resources() callback below
1273 * might rely on the serialization or the magic power management
1274 * functions which are abusing the irq_bus_lock() callback,
1276 chip_bus_lock(desc
);
1278 /* First installed action requests resources. */
1279 if (!desc
->action
) {
1280 ret
= irq_request_resources(desc
);
1282 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1283 new->name
, irq
, desc
->irq_data
.chip
->name
);
1284 goto out_bus_unlock
;
1289 * The following block of code has to be executed atomically
1290 * protected against a concurrent interrupt and any of the other
1291 * management calls which are not serialized via
1292 * desc->request_mutex or the optional bus lock.
1294 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1295 old_ptr
= &desc
->action
;
1299 * Can't share interrupts unless both agree to and are
1300 * the same type (level, edge, polarity). So both flag
1301 * fields must have IRQF_SHARED set and the bits which
1302 * set the trigger type must match. Also all must
1305 unsigned int oldtype
;
1308 * If nobody did set the configuration before, inherit
1309 * the one provided by the requester.
1311 if (irqd_trigger_type_was_set(&desc
->irq_data
)) {
1312 oldtype
= irqd_get_trigger_type(&desc
->irq_data
);
1314 oldtype
= new->flags
& IRQF_TRIGGER_MASK
;
1315 irqd_set_trigger_type(&desc
->irq_data
, oldtype
);
1318 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
1319 (oldtype
!= (new->flags
& IRQF_TRIGGER_MASK
)) ||
1320 ((old
->flags
^ new->flags
) & IRQF_ONESHOT
))
1323 /* All handlers must agree on per-cpuness */
1324 if ((old
->flags
& IRQF_PERCPU
) !=
1325 (new->flags
& IRQF_PERCPU
))
1328 /* add new interrupt at end of irq queue */
1331 * Or all existing action->thread_mask bits,
1332 * so we can find the next zero bit for this
1335 thread_mask
|= old
->thread_mask
;
1336 old_ptr
= &old
->next
;
1343 * Setup the thread mask for this irqaction for ONESHOT. For
1344 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1345 * conditional in irq_wake_thread().
1347 if (new->flags
& IRQF_ONESHOT
) {
1349 * Unlikely to have 32 resp 64 irqs sharing one line,
1352 if (thread_mask
== ~0UL) {
1357 * The thread_mask for the action is or'ed to
1358 * desc->thread_active to indicate that the
1359 * IRQF_ONESHOT thread handler has been woken, but not
1360 * yet finished. The bit is cleared when a thread
1361 * completes. When all threads of a shared interrupt
1362 * line have completed desc->threads_active becomes
1363 * zero and the interrupt line is unmasked. See
1364 * handle.c:irq_wake_thread() for further information.
1366 * If no thread is woken by primary (hard irq context)
1367 * interrupt handlers, then desc->threads_active is
1368 * also checked for zero to unmask the irq line in the
1369 * affected hard irq flow handlers
1370 * (handle_[fasteoi|level]_irq).
1372 * The new action gets the first zero bit of
1373 * thread_mask assigned. See the loop above which or's
1374 * all existing action->thread_mask bits.
1376 new->thread_mask
= 1UL << ffz(thread_mask
);
1378 } else if (new->handler
== irq_default_primary_handler
&&
1379 !(desc
->irq_data
.chip
->flags
& IRQCHIP_ONESHOT_SAFE
)) {
1381 * The interrupt was requested with handler = NULL, so
1382 * we use the default primary handler for it. But it
1383 * does not have the oneshot flag set. In combination
1384 * with level interrupts this is deadly, because the
1385 * default primary handler just wakes the thread, then
1386 * the irq lines is reenabled, but the device still
1387 * has the level irq asserted. Rinse and repeat....
1389 * While this works for edge type interrupts, we play
1390 * it safe and reject unconditionally because we can't
1391 * say for sure which type this interrupt really
1392 * has. The type flags are unreliable as the
1393 * underlying chip implementation can override them.
1395 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1402 init_waitqueue_head(&desc
->wait_for_threads
);
1404 /* Setup the type (level, edge polarity) if configured: */
1405 if (new->flags
& IRQF_TRIGGER_MASK
) {
1406 ret
= __irq_set_trigger(desc
,
1407 new->flags
& IRQF_TRIGGER_MASK
);
1414 * Activate the interrupt. That activation must happen
1415 * independently of IRQ_NOAUTOEN. request_irq() can fail
1416 * and the callers are supposed to handle
1417 * that. enable_irq() of an interrupt requested with
1418 * IRQ_NOAUTOEN is not supposed to fail. The activation
1419 * keeps it in shutdown mode, it merily associates
1420 * resources if necessary and if that's not possible it
1421 * fails. Interrupts which are in managed shutdown mode
1422 * will simply ignore that activation request.
1424 ret
= irq_activate(desc
);
1428 desc
->istate
&= ~(IRQS_AUTODETECT
| IRQS_SPURIOUS_DISABLED
| \
1429 IRQS_ONESHOT
| IRQS_WAITING
);
1430 irqd_clear(&desc
->irq_data
, IRQD_IRQ_INPROGRESS
);
1432 if (new->flags
& IRQF_PERCPU
) {
1433 irqd_set(&desc
->irq_data
, IRQD_PER_CPU
);
1434 irq_settings_set_per_cpu(desc
);
1437 if (new->flags
& IRQF_ONESHOT
)
1438 desc
->istate
|= IRQS_ONESHOT
;
1440 /* Exclude IRQ from balancing if requested */
1441 if (new->flags
& IRQF_NOBALANCING
) {
1442 irq_settings_set_no_balancing(desc
);
1443 irqd_set(&desc
->irq_data
, IRQD_NO_BALANCING
);
1446 if (irq_settings_can_autoenable(desc
)) {
1447 irq_startup(desc
, IRQ_RESEND
, IRQ_START_COND
);
1450 * Shared interrupts do not go well with disabling
1451 * auto enable. The sharing interrupt might request
1452 * it while it's still disabled and then wait for
1453 * interrupts forever.
1455 WARN_ON_ONCE(new->flags
& IRQF_SHARED
);
1456 /* Undo nested disables: */
1460 } else if (new->flags
& IRQF_TRIGGER_MASK
) {
1461 unsigned int nmsk
= new->flags
& IRQF_TRIGGER_MASK
;
1462 unsigned int omsk
= irqd_get_trigger_type(&desc
->irq_data
);
1465 /* hope the handler works with current trigger mode */
1466 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1472 irq_pm_install_action(desc
, new);
1474 /* Reset broken irq detection when installing new handler */
1475 desc
->irq_count
= 0;
1476 desc
->irqs_unhandled
= 0;
1479 * Check whether we disabled the irq via the spurious handler
1480 * before. Reenable it and give it another chance.
1482 if (shared
&& (desc
->istate
& IRQS_SPURIOUS_DISABLED
)) {
1483 desc
->istate
&= ~IRQS_SPURIOUS_DISABLED
;
1487 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1488 chip_bus_sync_unlock(desc
);
1489 mutex_unlock(&desc
->request_mutex
);
1491 irq_setup_timings(desc
, new);
1494 * Strictly no need to wake it up, but hung_task complains
1495 * when no hard interrupt wakes the thread up.
1498 wake_up_process(new->thread
);
1500 wake_up_process(new->secondary
->thread
);
1502 register_irq_proc(irq
, desc
);
1504 register_handler_proc(irq
, new);
1508 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
1509 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1510 irq
, new->flags
, new->name
, old
->flags
, old
->name
);
1511 #ifdef CONFIG_DEBUG_SHIRQ
1518 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1521 irq_release_resources(desc
);
1523 chip_bus_sync_unlock(desc
);
1524 mutex_unlock(&desc
->request_mutex
);
1528 struct task_struct
*t
= new->thread
;
1534 if (new->secondary
&& new->secondary
->thread
) {
1535 struct task_struct
*t
= new->secondary
->thread
;
1537 new->secondary
->thread
= NULL
;
1542 module_put(desc
->owner
);
1547 * setup_irq - setup an interrupt
1548 * @irq: Interrupt line to setup
1549 * @act: irqaction for the interrupt
1551 * Used to statically setup interrupts in the early boot process.
1553 int setup_irq(unsigned int irq
, struct irqaction
*act
)
1556 struct irq_desc
*desc
= irq_to_desc(irq
);
1558 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1561 retval
= irq_chip_pm_get(&desc
->irq_data
);
1565 retval
= __setup_irq(irq
, desc
, act
);
1568 irq_chip_pm_put(&desc
->irq_data
);
1572 EXPORT_SYMBOL_GPL(setup_irq
);
1575 * Internal function to unregister an irqaction - used to free
1576 * regular and special interrupts that are part of the architecture.
1578 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
1580 struct irq_desc
*desc
= irq_to_desc(irq
);
1581 struct irqaction
*action
, **action_ptr
;
1582 unsigned long flags
;
1584 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
1589 mutex_lock(&desc
->request_mutex
);
1590 chip_bus_lock(desc
);
1591 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1594 * There can be multiple actions per IRQ descriptor, find the right
1595 * one based on the dev_id:
1597 action_ptr
= &desc
->action
;
1599 action
= *action_ptr
;
1602 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
1603 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1604 chip_bus_sync_unlock(desc
);
1605 mutex_unlock(&desc
->request_mutex
);
1609 if (action
->dev_id
== dev_id
)
1611 action_ptr
= &action
->next
;
1614 /* Found it - now remove it from the list of entries: */
1615 *action_ptr
= action
->next
;
1617 irq_pm_remove_action(desc
, action
);
1619 /* If this was the last handler, shut down the IRQ line: */
1620 if (!desc
->action
) {
1621 irq_settings_clr_disable_unlazy(desc
);
1622 /* Only shutdown. Deactivate after synchronize_hardirq() */
1627 /* make sure affinity_hint is cleaned up */
1628 if (WARN_ON_ONCE(desc
->affinity_hint
))
1629 desc
->affinity_hint
= NULL
;
1632 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1634 * Drop bus_lock here so the changes which were done in the chip
1635 * callbacks above are synced out to the irq chips which hang
1636 * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1638 * Aside of that the bus_lock can also be taken from the threaded
1639 * handler in irq_finalize_oneshot() which results in a deadlock
1640 * because synchronize_irq() would wait forever for the thread to
1641 * complete, which is blocked on the bus lock.
1643 * The still held desc->request_mutex() protects against a
1644 * concurrent request_irq() of this irq so the release of resources
1645 * and timing data is properly serialized.
1647 chip_bus_sync_unlock(desc
);
1649 unregister_handler_proc(irq
, action
);
1651 /* Make sure it's not being used on another CPU: */
1652 synchronize_irq(irq
);
1654 #ifdef CONFIG_DEBUG_SHIRQ
1656 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1657 * event to happen even now it's being freed, so let's make sure that
1658 * is so by doing an extra call to the handler ....
1660 * ( We do this after actually deregistering it, to make sure that a
1661 * 'real' IRQ doesn't run in * parallel with our fake. )
1663 if (action
->flags
& IRQF_SHARED
) {
1664 local_irq_save(flags
);
1665 action
->handler(irq
, dev_id
);
1666 local_irq_restore(flags
);
1670 if (action
->thread
) {
1671 kthread_stop(action
->thread
);
1672 put_task_struct(action
->thread
);
1673 if (action
->secondary
&& action
->secondary
->thread
) {
1674 kthread_stop(action
->secondary
->thread
);
1675 put_task_struct(action
->secondary
->thread
);
1679 /* Last action releases resources */
1680 if (!desc
->action
) {
1682 * Reaquire bus lock as irq_release_resources() might
1683 * require it to deallocate resources over the slow bus.
1685 chip_bus_lock(desc
);
1687 * There is no interrupt on the fly anymore. Deactivate it
1690 raw_spin_lock_irqsave(&desc
->lock
, flags
);
1691 irq_domain_deactivate_irq(&desc
->irq_data
);
1692 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
1694 irq_release_resources(desc
);
1695 chip_bus_sync_unlock(desc
);
1696 irq_remove_timings(desc
);
1699 mutex_unlock(&desc
->request_mutex
);
1701 irq_chip_pm_put(&desc
->irq_data
);
1702 module_put(desc
->owner
);
1703 kfree(action
->secondary
);
1708 * remove_irq - free an interrupt
1709 * @irq: Interrupt line to free
1710 * @act: irqaction for the interrupt
1712 * Used to remove interrupts statically setup by the early boot process.
1714 void remove_irq(unsigned int irq
, struct irqaction
*act
)
1716 struct irq_desc
*desc
= irq_to_desc(irq
);
1718 if (desc
&& !WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1719 __free_irq(irq
, act
->dev_id
);
1721 EXPORT_SYMBOL_GPL(remove_irq
);
1724 * free_irq - free an interrupt allocated with request_irq
1725 * @irq: Interrupt line to free
1726 * @dev_id: Device identity to free
1728 * Remove an interrupt handler. The handler is removed and if the
1729 * interrupt line is no longer in use by any driver it is disabled.
1730 * On a shared IRQ the caller must ensure the interrupt is disabled
1731 * on the card it drives before calling this function. The function
1732 * does not return until any executing interrupts for this IRQ
1735 * This function must not be called from interrupt context.
1737 * Returns the devname argument passed to request_irq.
1739 const void *free_irq(unsigned int irq
, void *dev_id
)
1741 struct irq_desc
*desc
= irq_to_desc(irq
);
1742 struct irqaction
*action
;
1743 const char *devname
;
1745 if (!desc
|| WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1749 if (WARN_ON(desc
->affinity_notify
))
1750 desc
->affinity_notify
= NULL
;
1753 action
= __free_irq(irq
, dev_id
);
1758 devname
= action
->name
;
1762 EXPORT_SYMBOL(free_irq
);
1765 * request_threaded_irq - allocate an interrupt line
1766 * @irq: Interrupt line to allocate
1767 * @handler: Function to be called when the IRQ occurs.
1768 * Primary handler for threaded interrupts
1769 * If NULL and thread_fn != NULL the default
1770 * primary handler is installed
1771 * @thread_fn: Function called from the irq handler thread
1772 * If NULL, no irq thread is created
1773 * @irqflags: Interrupt type flags
1774 * @devname: An ascii name for the claiming device
1775 * @dev_id: A cookie passed back to the handler function
1777 * This call allocates interrupt resources and enables the
1778 * interrupt line and IRQ handling. From the point this
1779 * call is made your handler function may be invoked. Since
1780 * your handler function must clear any interrupt the board
1781 * raises, you must take care both to initialise your hardware
1782 * and to set up the interrupt handler in the right order.
1784 * If you want to set up a threaded irq handler for your device
1785 * then you need to supply @handler and @thread_fn. @handler is
1786 * still called in hard interrupt context and has to check
1787 * whether the interrupt originates from the device. If yes it
1788 * needs to disable the interrupt on the device and return
1789 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1790 * @thread_fn. This split handler design is necessary to support
1791 * shared interrupts.
1793 * Dev_id must be globally unique. Normally the address of the
1794 * device data structure is used as the cookie. Since the handler
1795 * receives this value it makes sense to use it.
1797 * If your interrupt is shared you must pass a non NULL dev_id
1798 * as this is required when freeing the interrupt.
1802 * IRQF_SHARED Interrupt is shared
1803 * IRQF_TRIGGER_* Specify active edge(s) or level
1806 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
1807 irq_handler_t thread_fn
, unsigned long irqflags
,
1808 const char *devname
, void *dev_id
)
1810 struct irqaction
*action
;
1811 struct irq_desc
*desc
;
1814 if (irq
== IRQ_NOTCONNECTED
)
1818 * Sanity-check: shared interrupts must pass in a real dev-ID,
1819 * otherwise we'll have trouble later trying to figure out
1820 * which interrupt is which (messes up the interrupt freeing
1823 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1824 * it cannot be set along with IRQF_NO_SUSPEND.
1826 if (((irqflags
& IRQF_SHARED
) && !dev_id
) ||
1827 (!(irqflags
& IRQF_SHARED
) && (irqflags
& IRQF_COND_SUSPEND
)) ||
1828 ((irqflags
& IRQF_NO_SUSPEND
) && (irqflags
& IRQF_COND_SUSPEND
)))
1831 desc
= irq_to_desc(irq
);
1835 if (!irq_settings_can_request(desc
) ||
1836 WARN_ON(irq_settings_is_per_cpu_devid(desc
)))
1842 handler
= irq_default_primary_handler
;
1845 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
1849 action
->handler
= handler
;
1850 action
->thread_fn
= thread_fn
;
1851 action
->flags
= irqflags
;
1852 action
->name
= devname
;
1853 action
->dev_id
= dev_id
;
1855 retval
= irq_chip_pm_get(&desc
->irq_data
);
1861 retval
= __setup_irq(irq
, desc
, action
);
1864 irq_chip_pm_put(&desc
->irq_data
);
1865 kfree(action
->secondary
);
1869 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1870 if (!retval
&& (irqflags
& IRQF_SHARED
)) {
1872 * It's a shared IRQ -- the driver ought to be prepared for it
1873 * to happen immediately, so let's make sure....
1874 * We disable the irq to make sure that a 'real' IRQ doesn't
1875 * run in parallel with our fake.
1877 unsigned long flags
;
1880 local_irq_save(flags
);
1882 handler(irq
, dev_id
);
1884 local_irq_restore(flags
);
1890 EXPORT_SYMBOL(request_threaded_irq
);
1893 * request_any_context_irq - allocate an interrupt line
1894 * @irq: Interrupt line to allocate
1895 * @handler: Function to be called when the IRQ occurs.
1896 * Threaded handler for threaded interrupts.
1897 * @flags: Interrupt type flags
1898 * @name: An ascii name for the claiming device
1899 * @dev_id: A cookie passed back to the handler function
1901 * This call allocates interrupt resources and enables the
1902 * interrupt line and IRQ handling. It selects either a
1903 * hardirq or threaded handling method depending on the
1906 * On failure, it returns a negative value. On success,
1907 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1909 int request_any_context_irq(unsigned int irq
, irq_handler_t handler
,
1910 unsigned long flags
, const char *name
, void *dev_id
)
1912 struct irq_desc
*desc
;
1915 if (irq
== IRQ_NOTCONNECTED
)
1918 desc
= irq_to_desc(irq
);
1922 if (irq_settings_is_nested_thread(desc
)) {
1923 ret
= request_threaded_irq(irq
, NULL
, handler
,
1924 flags
, name
, dev_id
);
1925 return !ret
? IRQC_IS_NESTED
: ret
;
1928 ret
= request_irq(irq
, handler
, flags
, name
, dev_id
);
1929 return !ret
? IRQC_IS_HARDIRQ
: ret
;
1931 EXPORT_SYMBOL_GPL(request_any_context_irq
);
1933 void enable_percpu_irq(unsigned int irq
, unsigned int type
)
1935 unsigned int cpu
= smp_processor_id();
1936 unsigned long flags
;
1937 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1943 * If the trigger type is not specified by the caller, then
1944 * use the default for this interrupt.
1946 type
&= IRQ_TYPE_SENSE_MASK
;
1947 if (type
== IRQ_TYPE_NONE
)
1948 type
= irqd_get_trigger_type(&desc
->irq_data
);
1950 if (type
!= IRQ_TYPE_NONE
) {
1953 ret
= __irq_set_trigger(desc
, type
);
1956 WARN(1, "failed to set type for IRQ%d\n", irq
);
1961 irq_percpu_enable(desc
, cpu
);
1963 irq_put_desc_unlock(desc
, flags
);
1965 EXPORT_SYMBOL_GPL(enable_percpu_irq
);
1968 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1969 * @irq: Linux irq number to check for
1971 * Must be called from a non migratable context. Returns the enable
1972 * state of a per cpu interrupt on the current cpu.
1974 bool irq_percpu_is_enabled(unsigned int irq
)
1976 unsigned int cpu
= smp_processor_id();
1977 struct irq_desc
*desc
;
1978 unsigned long flags
;
1981 desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
1985 is_enabled
= cpumask_test_cpu(cpu
, desc
->percpu_enabled
);
1986 irq_put_desc_unlock(desc
, flags
);
1990 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled
);
1992 void disable_percpu_irq(unsigned int irq
)
1994 unsigned int cpu
= smp_processor_id();
1995 unsigned long flags
;
1996 struct irq_desc
*desc
= irq_get_desc_lock(irq
, &flags
, IRQ_GET_DESC_CHECK_PERCPU
);
2001 irq_percpu_disable(desc
, cpu
);
2002 irq_put_desc_unlock(desc
, flags
);
2004 EXPORT_SYMBOL_GPL(disable_percpu_irq
);
2007 * Internal function to unregister a percpu irqaction.
2009 static struct irqaction
*__free_percpu_irq(unsigned int irq
, void __percpu
*dev_id
)
2011 struct irq_desc
*desc
= irq_to_desc(irq
);
2012 struct irqaction
*action
;
2013 unsigned long flags
;
2015 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
2020 raw_spin_lock_irqsave(&desc
->lock
, flags
);
2022 action
= desc
->action
;
2023 if (!action
|| action
->percpu_dev_id
!= dev_id
) {
2024 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
2028 if (!cpumask_empty(desc
->percpu_enabled
)) {
2029 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2030 irq
, cpumask_first(desc
->percpu_enabled
));
2034 /* Found it - now remove it from the list of entries: */
2035 desc
->action
= NULL
;
2037 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
2039 unregister_handler_proc(irq
, action
);
2041 irq_chip_pm_put(&desc
->irq_data
);
2042 module_put(desc
->owner
);
2046 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
2051 * remove_percpu_irq - free a per-cpu interrupt
2052 * @irq: Interrupt line to free
2053 * @act: irqaction for the interrupt
2055 * Used to remove interrupts statically setup by the early boot process.
2057 void remove_percpu_irq(unsigned int irq
, struct irqaction
*act
)
2059 struct irq_desc
*desc
= irq_to_desc(irq
);
2061 if (desc
&& irq_settings_is_per_cpu_devid(desc
))
2062 __free_percpu_irq(irq
, act
->percpu_dev_id
);
2066 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2067 * @irq: Interrupt line to free
2068 * @dev_id: Device identity to free
2070 * Remove a percpu interrupt handler. The handler is removed, but
2071 * the interrupt line is not disabled. This must be done on each
2072 * CPU before calling this function. The function does not return
2073 * until any executing interrupts for this IRQ have completed.
2075 * This function must not be called from interrupt context.
2077 void free_percpu_irq(unsigned int irq
, void __percpu
*dev_id
)
2079 struct irq_desc
*desc
= irq_to_desc(irq
);
2081 if (!desc
|| !irq_settings_is_per_cpu_devid(desc
))
2084 chip_bus_lock(desc
);
2085 kfree(__free_percpu_irq(irq
, dev_id
));
2086 chip_bus_sync_unlock(desc
);
2088 EXPORT_SYMBOL_GPL(free_percpu_irq
);
2091 * setup_percpu_irq - setup a per-cpu interrupt
2092 * @irq: Interrupt line to setup
2093 * @act: irqaction for the interrupt
2095 * Used to statically setup per-cpu interrupts in the early boot process.
2097 int setup_percpu_irq(unsigned int irq
, struct irqaction
*act
)
2099 struct irq_desc
*desc
= irq_to_desc(irq
);
2102 if (!desc
|| !irq_settings_is_per_cpu_devid(desc
))
2105 retval
= irq_chip_pm_get(&desc
->irq_data
);
2109 retval
= __setup_irq(irq
, desc
, act
);
2112 irq_chip_pm_put(&desc
->irq_data
);
2118 * __request_percpu_irq - allocate a percpu interrupt line
2119 * @irq: Interrupt line to allocate
2120 * @handler: Function to be called when the IRQ occurs.
2121 * @flags: Interrupt type flags (IRQF_TIMER only)
2122 * @devname: An ascii name for the claiming device
2123 * @dev_id: A percpu cookie passed back to the handler function
2125 * This call allocates interrupt resources and enables the
2126 * interrupt on the local CPU. If the interrupt is supposed to be
2127 * enabled on other CPUs, it has to be done on each CPU using
2128 * enable_percpu_irq().
2130 * Dev_id must be globally unique. It is a per-cpu variable, and
2131 * the handler gets called with the interrupted CPU's instance of
2134 int __request_percpu_irq(unsigned int irq
, irq_handler_t handler
,
2135 unsigned long flags
, const char *devname
,
2136 void __percpu
*dev_id
)
2138 struct irqaction
*action
;
2139 struct irq_desc
*desc
;
2145 desc
= irq_to_desc(irq
);
2146 if (!desc
|| !irq_settings_can_request(desc
) ||
2147 !irq_settings_is_per_cpu_devid(desc
))
2150 if (flags
&& flags
!= IRQF_TIMER
)
2153 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
2157 action
->handler
= handler
;
2158 action
->flags
= flags
| IRQF_PERCPU
| IRQF_NO_SUSPEND
;
2159 action
->name
= devname
;
2160 action
->percpu_dev_id
= dev_id
;
2162 retval
= irq_chip_pm_get(&desc
->irq_data
);
2168 retval
= __setup_irq(irq
, desc
, action
);
2171 irq_chip_pm_put(&desc
->irq_data
);
2177 EXPORT_SYMBOL_GPL(__request_percpu_irq
);
2180 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2181 * @irq: Interrupt line that is forwarded to a VM
2182 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2183 * @state: a pointer to a boolean where the state is to be storeed
2185 * This call snapshots the internal irqchip state of an
2186 * interrupt, returning into @state the bit corresponding to
2189 * This function should be called with preemption disabled if the
2190 * interrupt controller has per-cpu registers.
2192 int irq_get_irqchip_state(unsigned int irq
, enum irqchip_irq_state which
,
2195 struct irq_desc
*desc
;
2196 struct irq_data
*data
;
2197 struct irq_chip
*chip
;
2198 unsigned long flags
;
2201 desc
= irq_get_desc_buslock(irq
, &flags
, 0);
2205 data
= irq_desc_get_irq_data(desc
);
2208 chip
= irq_data_get_irq_chip(data
);
2209 if (chip
->irq_get_irqchip_state
)
2211 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2212 data
= data
->parent_data
;
2219 err
= chip
->irq_get_irqchip_state(data
, which
, state
);
2221 irq_put_desc_busunlock(desc
, flags
);
2224 EXPORT_SYMBOL_GPL(irq_get_irqchip_state
);
2227 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2228 * @irq: Interrupt line that is forwarded to a VM
2229 * @which: State to be restored (one of IRQCHIP_STATE_*)
2230 * @val: Value corresponding to @which
2232 * This call sets the internal irqchip state of an interrupt,
2233 * depending on the value of @which.
2235 * This function should be called with preemption disabled if the
2236 * interrupt controller has per-cpu registers.
2238 int irq_set_irqchip_state(unsigned int irq
, enum irqchip_irq_state which
,
2241 struct irq_desc
*desc
;
2242 struct irq_data
*data
;
2243 struct irq_chip
*chip
;
2244 unsigned long flags
;
2247 desc
= irq_get_desc_buslock(irq
, &flags
, 0);
2251 data
= irq_desc_get_irq_data(desc
);
2254 chip
= irq_data_get_irq_chip(data
);
2255 if (chip
->irq_set_irqchip_state
)
2257 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2258 data
= data
->parent_data
;
2265 err
= chip
->irq_set_irqchip_state(data
, which
, val
);
2267 irq_put_desc_busunlock(desc
, flags
);
2270 EXPORT_SYMBOL_GPL(irq_set_irqchip_state
);