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1/*
2 * linux/kernel/irq/manage.c
3 *
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
6 *
7 * This file contains driver APIs to the irq subsystem.
8 */
9
10#define pr_fmt(fmt) "genirq: " fmt
11
12#include <linux/irq.h>
13#include <linux/kthread.h>
14#include <linux/module.h>
15#include <linux/random.h>
16#include <linux/interrupt.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/task_work.h>
21
22#include "internals.h"
23
24#ifdef CONFIG_IRQ_FORCED_THREADING
25__read_mostly bool force_irqthreads;
26
27static int __init setup_forced_irqthreads(char *arg)
28{
29 force_irqthreads = true;
30 return 0;
31}
32early_param("threadirqs", setup_forced_irqthreads);
33#endif
34
35static void __synchronize_hardirq(struct irq_desc *desc)
36{
37 bool inprogress;
38
39 do {
40 unsigned long flags;
41
42 /*
43 * Wait until we're out of the critical section. This might
44 * give the wrong answer due to the lack of memory barriers.
45 */
46 while (irqd_irq_inprogress(&desc->irq_data))
47 cpu_relax();
48
49 /* Ok, that indicated we're done: double-check carefully. */
50 raw_spin_lock_irqsave(&desc->lock, flags);
51 inprogress = irqd_irq_inprogress(&desc->irq_data);
52 raw_spin_unlock_irqrestore(&desc->lock, flags);
53
54 /* Oops, that failed? */
55 } while (inprogress);
56}
57
58/**
59 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
60 * @irq: interrupt number to wait for
61 *
62 * This function waits for any pending hard IRQ handlers for this
63 * interrupt to complete before returning. If you use this
64 * function while holding a resource the IRQ handler may need you
65 * will deadlock. It does not take associated threaded handlers
66 * into account.
67 *
68 * Do not use this for shutdown scenarios where you must be sure
69 * that all parts (hardirq and threaded handler) have completed.
70 *
71 * This function may be called - with care - from IRQ context.
72 */
73void synchronize_hardirq(unsigned int irq)
74{
75 struct irq_desc *desc = irq_to_desc(irq);
76
77 if (desc)
78 __synchronize_hardirq(desc);
79}
80EXPORT_SYMBOL(synchronize_hardirq);
81
82/**
83 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
84 * @irq: interrupt number to wait for
85 *
86 * This function waits for any pending IRQ handlers for this interrupt
87 * to complete before returning. If you use this function while
88 * holding a resource the IRQ handler may need you will deadlock.
89 *
90 * This function may be called - with care - from IRQ context.
91 */
92void synchronize_irq(unsigned int irq)
93{
94 struct irq_desc *desc = irq_to_desc(irq);
95
96 if (desc) {
97 __synchronize_hardirq(desc);
98 /*
99 * We made sure that no hardirq handler is
100 * running. Now verify that no threaded handlers are
101 * active.
102 */
103 wait_event(desc->wait_for_threads,
104 !atomic_read(&desc->threads_active));
105 }
106}
107EXPORT_SYMBOL(synchronize_irq);
108
109#ifdef CONFIG_SMP
110cpumask_var_t irq_default_affinity;
111
112/**
113 * irq_can_set_affinity - Check if the affinity of a given irq can be set
114 * @irq: Interrupt to check
115 *
116 */
117int irq_can_set_affinity(unsigned int irq)
118{
119 struct irq_desc *desc = irq_to_desc(irq);
120
121 if (!desc || !irqd_can_balance(&desc->irq_data) ||
122 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
123 return 0;
124
125 return 1;
126}
127
128/**
129 * irq_set_thread_affinity - Notify irq threads to adjust affinity
130 * @desc: irq descriptor which has affitnity changed
131 *
132 * We just set IRQTF_AFFINITY and delegate the affinity setting
133 * to the interrupt thread itself. We can not call
134 * set_cpus_allowed_ptr() here as we hold desc->lock and this
135 * code can be called from hard interrupt context.
136 */
137void irq_set_thread_affinity(struct irq_desc *desc)
138{
139 struct irqaction *action = desc->action;
140
141 while (action) {
142 if (action->thread)
143 set_bit(IRQTF_AFFINITY, &action->thread_flags);
144 action = action->next;
145 }
146}
147
148#ifdef CONFIG_GENERIC_PENDING_IRQ
149static inline bool irq_can_move_pcntxt(struct irq_data *data)
150{
151 return irqd_can_move_in_process_context(data);
152}
153static inline bool irq_move_pending(struct irq_data *data)
154{
155 return irqd_is_setaffinity_pending(data);
156}
157static inline void
158irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
159{
160 cpumask_copy(desc->pending_mask, mask);
161}
162static inline void
163irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
164{
165 cpumask_copy(mask, desc->pending_mask);
166}
167#else
168static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
169static inline bool irq_move_pending(struct irq_data *data) { return false; }
170static inline void
171irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
172static inline void
173irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
174#endif
175
176int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
177 bool force)
178{
179 struct irq_desc *desc = irq_data_to_desc(data);
180 struct irq_chip *chip = irq_data_get_irq_chip(data);
181 int ret;
182
183 ret = chip->irq_set_affinity(data, mask, force);
184 switch (ret) {
185 case IRQ_SET_MASK_OK:
186 cpumask_copy(data->affinity, mask);
187 case IRQ_SET_MASK_OK_NOCOPY:
188 irq_set_thread_affinity(desc);
189 ret = 0;
190 }
191
192 return ret;
193}
194
195int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
196 bool force)
197{
198 struct irq_chip *chip = irq_data_get_irq_chip(data);
199 struct irq_desc *desc = irq_data_to_desc(data);
200 int ret = 0;
201
202 if (!chip || !chip->irq_set_affinity)
203 return -EINVAL;
204
205 if (irq_can_move_pcntxt(data)) {
206 ret = irq_do_set_affinity(data, mask, force);
207 } else {
208 irqd_set_move_pending(data);
209 irq_copy_pending(desc, mask);
210 }
211
212 if (desc->affinity_notify) {
213 kref_get(&desc->affinity_notify->kref);
214 schedule_work(&desc->affinity_notify->work);
215 }
216 irqd_set(data, IRQD_AFFINITY_SET);
217
218 return ret;
219}
220
221int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
222{
223 struct irq_desc *desc = irq_to_desc(irq);
224 unsigned long flags;
225 int ret;
226
227 if (!desc)
228 return -EINVAL;
229
230 raw_spin_lock_irqsave(&desc->lock, flags);
231 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
232 raw_spin_unlock_irqrestore(&desc->lock, flags);
233 return ret;
234}
235
236int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
237{
238 unsigned long flags;
239 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
240
241 if (!desc)
242 return -EINVAL;
243 desc->affinity_hint = m;
244 irq_put_desc_unlock(desc, flags);
245 return 0;
246}
247EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
248
249static void irq_affinity_notify(struct work_struct *work)
250{
251 struct irq_affinity_notify *notify =
252 container_of(work, struct irq_affinity_notify, work);
253 struct irq_desc *desc = irq_to_desc(notify->irq);
254 cpumask_var_t cpumask;
255 unsigned long flags;
256
257 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
258 goto out;
259
260 raw_spin_lock_irqsave(&desc->lock, flags);
261 if (irq_move_pending(&desc->irq_data))
262 irq_get_pending(cpumask, desc);
263 else
264 cpumask_copy(cpumask, desc->irq_data.affinity);
265 raw_spin_unlock_irqrestore(&desc->lock, flags);
266
267 notify->notify(notify, cpumask);
268
269 free_cpumask_var(cpumask);
270out:
271 kref_put(¬ify->kref, notify->release);
272}
273
274/**
275 * irq_set_affinity_notifier - control notification of IRQ affinity changes
276 * @irq: Interrupt for which to enable/disable notification
277 * @notify: Context for notification, or %NULL to disable
278 * notification. Function pointers must be initialised;
279 * the other fields will be initialised by this function.
280 *
281 * Must be called in process context. Notification may only be enabled
282 * after the IRQ is allocated and must be disabled before the IRQ is
283 * freed using free_irq().
284 */
285int
286irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
287{
288 struct irq_desc *desc = irq_to_desc(irq);
289 struct irq_affinity_notify *old_notify;
290 unsigned long flags;
291
292 /* The release function is promised process context */
293 might_sleep();
294
295 if (!desc)
296 return -EINVAL;
297
298 /* Complete initialisation of *notify */
299 if (notify) {
300 notify->irq = irq;
301 kref_init(¬ify->kref);
302 INIT_WORK(¬ify->work, irq_affinity_notify);
303 }
304
305 raw_spin_lock_irqsave(&desc->lock, flags);
306 old_notify = desc->affinity_notify;
307 desc->affinity_notify = notify;
308 raw_spin_unlock_irqrestore(&desc->lock, flags);
309
310 if (old_notify)
311 kref_put(&old_notify->kref, old_notify->release);
312
313 return 0;
314}
315EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
316
317#ifndef CONFIG_AUTO_IRQ_AFFINITY
318/*
319 * Generic version of the affinity autoselector.
320 */
321static int
322setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
323{
324 struct cpumask *set = irq_default_affinity;
325 int node = desc->irq_data.node;
326
327 /* Excludes PER_CPU and NO_BALANCE interrupts */
328 if (!irq_can_set_affinity(irq))
329 return 0;
330
331 /*
332 * Preserve an userspace affinity setup, but make sure that
333 * one of the targets is online.
334 */
335 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
336 if (cpumask_intersects(desc->irq_data.affinity,
337 cpu_online_mask))
338 set = desc->irq_data.affinity;
339 else
340 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
341 }
342
343 cpumask_and(mask, cpu_online_mask, set);
344 if (node != NUMA_NO_NODE) {
345 const struct cpumask *nodemask = cpumask_of_node(node);
346
347 /* make sure at least one of the cpus in nodemask is online */
348 if (cpumask_intersects(mask, nodemask))
349 cpumask_and(mask, mask, nodemask);
350 }
351 irq_do_set_affinity(&desc->irq_data, mask, false);
352 return 0;
353}
354#else
355static inline int
356setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
357{
358 return irq_select_affinity(irq);
359}
360#endif
361
362/*
363 * Called when affinity is set via /proc/irq
364 */
365int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
366{
367 struct irq_desc *desc = irq_to_desc(irq);
368 unsigned long flags;
369 int ret;
370
371 raw_spin_lock_irqsave(&desc->lock, flags);
372 ret = setup_affinity(irq, desc, mask);
373 raw_spin_unlock_irqrestore(&desc->lock, flags);
374 return ret;
375}
376
377#else
378static inline int
379setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
380{
381 return 0;
382}
383#endif
384
385void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
386{
387 if (suspend) {
388 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
389 return;
390 desc->istate |= IRQS_SUSPENDED;
391 }
392
393 if (!desc->depth++)
394 irq_disable(desc);
395}
396
397static int __disable_irq_nosync(unsigned int irq)
398{
399 unsigned long flags;
400 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
401
402 if (!desc)
403 return -EINVAL;
404 __disable_irq(desc, irq, false);
405 irq_put_desc_busunlock(desc, flags);
406 return 0;
407}
408
409/**
410 * disable_irq_nosync - disable an irq without waiting
411 * @irq: Interrupt to disable
412 *
413 * Disable the selected interrupt line. Disables and Enables are
414 * nested.
415 * Unlike disable_irq(), this function does not ensure existing
416 * instances of the IRQ handler have completed before returning.
417 *
418 * This function may be called from IRQ context.
419 */
420void disable_irq_nosync(unsigned int irq)
421{
422 __disable_irq_nosync(irq);
423}
424EXPORT_SYMBOL(disable_irq_nosync);
425
426/**
427 * disable_irq - disable an irq and wait for completion
428 * @irq: Interrupt to disable
429 *
430 * Disable the selected interrupt line. Enables and Disables are
431 * nested.
432 * This function waits for any pending IRQ handlers for this interrupt
433 * to complete before returning. If you use this function while
434 * holding a resource the IRQ handler may need you will deadlock.
435 *
436 * This function may be called - with care - from IRQ context.
437 */
438void disable_irq(unsigned int irq)
439{
440 if (!__disable_irq_nosync(irq))
441 synchronize_irq(irq);
442}
443EXPORT_SYMBOL(disable_irq);
444
445void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
446{
447 if (resume) {
448 if (!(desc->istate & IRQS_SUSPENDED)) {
449 if (!desc->action)
450 return;
451 if (!(desc->action->flags & IRQF_FORCE_RESUME))
452 return;
453 /* Pretend that it got disabled ! */
454 desc->depth++;
455 }
456 desc->istate &= ~IRQS_SUSPENDED;
457 }
458
459 switch (desc->depth) {
460 case 0:
461 err_out:
462 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
463 break;
464 case 1: {
465 if (desc->istate & IRQS_SUSPENDED)
466 goto err_out;
467 /* Prevent probing on this irq: */
468 irq_settings_set_noprobe(desc);
469 irq_enable(desc);
470 check_irq_resend(desc, irq);
471 /* fall-through */
472 }
473 default:
474 desc->depth--;
475 }
476}
477
478/**
479 * enable_irq - enable handling of an irq
480 * @irq: Interrupt to enable
481 *
482 * Undoes the effect of one call to disable_irq(). If this
483 * matches the last disable, processing of interrupts on this
484 * IRQ line is re-enabled.
485 *
486 * This function may be called from IRQ context only when
487 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
488 */
489void enable_irq(unsigned int irq)
490{
491 unsigned long flags;
492 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
493
494 if (!desc)
495 return;
496 if (WARN(!desc->irq_data.chip,
497 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
498 goto out;
499
500 __enable_irq(desc, irq, false);
501out:
502 irq_put_desc_busunlock(desc, flags);
503}
504EXPORT_SYMBOL(enable_irq);
505
506static int set_irq_wake_real(unsigned int irq, unsigned int on)
507{
508 struct irq_desc *desc = irq_to_desc(irq);
509 int ret = -ENXIO;
510
511 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
512 return 0;
513
514 if (desc->irq_data.chip->irq_set_wake)
515 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
516
517 return ret;
518}
519
520/**
521 * irq_set_irq_wake - control irq power management wakeup
522 * @irq: interrupt to control
523 * @on: enable/disable power management wakeup
524 *
525 * Enable/disable power management wakeup mode, which is
526 * disabled by default. Enables and disables must match,
527 * just as they match for non-wakeup mode support.
528 *
529 * Wakeup mode lets this IRQ wake the system from sleep
530 * states like "suspend to RAM".
531 */
532int irq_set_irq_wake(unsigned int irq, unsigned int on)
533{
534 unsigned long flags;
535 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
536 int ret = 0;
537
538 if (!desc)
539 return -EINVAL;
540
541 /* wakeup-capable irqs can be shared between drivers that
542 * don't need to have the same sleep mode behaviors.
543 */
544 if (on) {
545 if (desc->wake_depth++ == 0) {
546 ret = set_irq_wake_real(irq, on);
547 if (ret)
548 desc->wake_depth = 0;
549 else
550 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
551 }
552 } else {
553 if (desc->wake_depth == 0) {
554 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
555 } else if (--desc->wake_depth == 0) {
556 ret = set_irq_wake_real(irq, on);
557 if (ret)
558 desc->wake_depth = 1;
559 else
560 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
561 }
562 }
563 irq_put_desc_busunlock(desc, flags);
564 return ret;
565}
566EXPORT_SYMBOL(irq_set_irq_wake);
567
568/*
569 * Internal function that tells the architecture code whether a
570 * particular irq has been exclusively allocated or is available
571 * for driver use.
572 */
573int can_request_irq(unsigned int irq, unsigned long irqflags)
574{
575 unsigned long flags;
576 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
577 int canrequest = 0;
578
579 if (!desc)
580 return 0;
581
582 if (irq_settings_can_request(desc)) {
583 if (!desc->action ||
584 irqflags & desc->action->flags & IRQF_SHARED)
585 canrequest = 1;
586 }
587 irq_put_desc_unlock(desc, flags);
588 return canrequest;
589}
590
591int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
592 unsigned long flags)
593{
594 struct irq_chip *chip = desc->irq_data.chip;
595 int ret, unmask = 0;
596
597 if (!chip || !chip->irq_set_type) {
598 /*
599 * IRQF_TRIGGER_* but the PIC does not support multiple
600 * flow-types?
601 */
602 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
603 chip ? (chip->name ? : "unknown") : "unknown");
604 return 0;
605 }
606
607 flags &= IRQ_TYPE_SENSE_MASK;
608
609 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
610 if (!irqd_irq_masked(&desc->irq_data))
611 mask_irq(desc);
612 if (!irqd_irq_disabled(&desc->irq_data))
613 unmask = 1;
614 }
615
616 /* caller masked out all except trigger mode flags */
617 ret = chip->irq_set_type(&desc->irq_data, flags);
618
619 switch (ret) {
620 case IRQ_SET_MASK_OK:
621 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
622 irqd_set(&desc->irq_data, flags);
623
624 case IRQ_SET_MASK_OK_NOCOPY:
625 flags = irqd_get_trigger_type(&desc->irq_data);
626 irq_settings_set_trigger_mask(desc, flags);
627 irqd_clear(&desc->irq_data, IRQD_LEVEL);
628 irq_settings_clr_level(desc);
629 if (flags & IRQ_TYPE_LEVEL_MASK) {
630 irq_settings_set_level(desc);
631 irqd_set(&desc->irq_data, IRQD_LEVEL);
632 }
633
634 ret = 0;
635 break;
636 default:
637 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
638 flags, irq, chip->irq_set_type);
639 }
640 if (unmask)
641 unmask_irq(desc);
642 return ret;
643}
644
645#ifdef CONFIG_HARDIRQS_SW_RESEND
646int irq_set_parent(int irq, int parent_irq)
647{
648 unsigned long flags;
649 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
650
651 if (!desc)
652 return -EINVAL;
653
654 desc->parent_irq = parent_irq;
655
656 irq_put_desc_unlock(desc, flags);
657 return 0;
658}
659#endif
660
661/*
662 * Default primary interrupt handler for threaded interrupts. Is
663 * assigned as primary handler when request_threaded_irq is called
664 * with handler == NULL. Useful for oneshot interrupts.
665 */
666static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
667{
668 return IRQ_WAKE_THREAD;
669}
670
671/*
672 * Primary handler for nested threaded interrupts. Should never be
673 * called.
674 */
675static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
676{
677 WARN(1, "Primary handler called for nested irq %d\n", irq);
678 return IRQ_NONE;
679}
680
681static int irq_wait_for_interrupt(struct irqaction *action)
682{
683 set_current_state(TASK_INTERRUPTIBLE);
684
685 while (!kthread_should_stop()) {
686
687 if (test_and_clear_bit(IRQTF_RUNTHREAD,
688 &action->thread_flags)) {
689 __set_current_state(TASK_RUNNING);
690 return 0;
691 }
692 schedule();
693 set_current_state(TASK_INTERRUPTIBLE);
694 }
695 __set_current_state(TASK_RUNNING);
696 return -1;
697}
698
699/*
700 * Oneshot interrupts keep the irq line masked until the threaded
701 * handler finished. unmask if the interrupt has not been disabled and
702 * is marked MASKED.
703 */
704static void irq_finalize_oneshot(struct irq_desc *desc,
705 struct irqaction *action)
706{
707 if (!(desc->istate & IRQS_ONESHOT))
708 return;
709again:
710 chip_bus_lock(desc);
711 raw_spin_lock_irq(&desc->lock);
712
713 /*
714 * Implausible though it may be we need to protect us against
715 * the following scenario:
716 *
717 * The thread is faster done than the hard interrupt handler
718 * on the other CPU. If we unmask the irq line then the
719 * interrupt can come in again and masks the line, leaves due
720 * to IRQS_INPROGRESS and the irq line is masked forever.
721 *
722 * This also serializes the state of shared oneshot handlers
723 * versus "desc->threads_onehsot |= action->thread_mask;" in
724 * irq_wake_thread(). See the comment there which explains the
725 * serialization.
726 */
727 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
728 raw_spin_unlock_irq(&desc->lock);
729 chip_bus_sync_unlock(desc);
730 cpu_relax();
731 goto again;
732 }
733
734 /*
735 * Now check again, whether the thread should run. Otherwise
736 * we would clear the threads_oneshot bit of this thread which
737 * was just set.
738 */
739 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
740 goto out_unlock;
741
742 desc->threads_oneshot &= ~action->thread_mask;
743
744 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
745 irqd_irq_masked(&desc->irq_data))
746 unmask_threaded_irq(desc);
747
748out_unlock:
749 raw_spin_unlock_irq(&desc->lock);
750 chip_bus_sync_unlock(desc);
751}
752
753#ifdef CONFIG_SMP
754/*
755 * Check whether we need to change the affinity of the interrupt thread.
756 */
757static void
758irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
759{
760 cpumask_var_t mask;
761 bool valid = true;
762
763 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
764 return;
765
766 /*
767 * In case we are out of memory we set IRQTF_AFFINITY again and
768 * try again next time
769 */
770 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
771 set_bit(IRQTF_AFFINITY, &action->thread_flags);
772 return;
773 }
774
775 raw_spin_lock_irq(&desc->lock);
776 /*
777 * This code is triggered unconditionally. Check the affinity
778 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
779 */
780 if (desc->irq_data.affinity)
781 cpumask_copy(mask, desc->irq_data.affinity);
782 else
783 valid = false;
784 raw_spin_unlock_irq(&desc->lock);
785
786 if (valid)
787 set_cpus_allowed_ptr(current, mask);
788 free_cpumask_var(mask);
789}
790#else
791static inline void
792irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
793#endif
794
795/*
796 * Interrupts which are not explicitely requested as threaded
797 * interrupts rely on the implicit bh/preempt disable of the hard irq
798 * context. So we need to disable bh here to avoid deadlocks and other
799 * side effects.
800 */
801static irqreturn_t
802irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
803{
804 irqreturn_t ret;
805
806 local_bh_disable();
807 ret = action->thread_fn(action->irq, action->dev_id);
808 irq_finalize_oneshot(desc, action);
809 local_bh_enable();
810 return ret;
811}
812
813/*
814 * Interrupts explicitly requested as threaded interrupts want to be
815 * preemtible - many of them need to sleep and wait for slow busses to
816 * complete.
817 */
818static irqreturn_t irq_thread_fn(struct irq_desc *desc,
819 struct irqaction *action)
820{
821 irqreturn_t ret;
822
823 ret = action->thread_fn(action->irq, action->dev_id);
824 irq_finalize_oneshot(desc, action);
825 return ret;
826}
827
828static void wake_threads_waitq(struct irq_desc *desc)
829{
830 if (atomic_dec_and_test(&desc->threads_active))
831 wake_up(&desc->wait_for_threads);
832}
833
834static void irq_thread_dtor(struct callback_head *unused)
835{
836 struct task_struct *tsk = current;
837 struct irq_desc *desc;
838 struct irqaction *action;
839
840 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
841 return;
842
843 action = kthread_data(tsk);
844
845 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
846 tsk->comm, tsk->pid, action->irq);
847
848
849 desc = irq_to_desc(action->irq);
850 /*
851 * If IRQTF_RUNTHREAD is set, we need to decrement
852 * desc->threads_active and wake possible waiters.
853 */
854 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
855 wake_threads_waitq(desc);
856
857 /* Prevent a stale desc->threads_oneshot */
858 irq_finalize_oneshot(desc, action);
859}
860
861/*
862 * Interrupt handler thread
863 */
864static int irq_thread(void *data)
865{
866 struct callback_head on_exit_work;
867 struct irqaction *action = data;
868 struct irq_desc *desc = irq_to_desc(action->irq);
869 irqreturn_t (*handler_fn)(struct irq_desc *desc,
870 struct irqaction *action);
871
872 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
873 &action->thread_flags))
874 handler_fn = irq_forced_thread_fn;
875 else
876 handler_fn = irq_thread_fn;
877
878 init_task_work(&on_exit_work, irq_thread_dtor);
879 task_work_add(current, &on_exit_work, false);
880
881 irq_thread_check_affinity(desc, action);
882
883 while (!irq_wait_for_interrupt(action)) {
884 irqreturn_t action_ret;
885
886 irq_thread_check_affinity(desc, action);
887
888 action_ret = handler_fn(desc, action);
889 if (!noirqdebug)
890 note_interrupt(action->irq, desc, action_ret);
891
892 wake_threads_waitq(desc);
893 }
894
895 /*
896 * This is the regular exit path. __free_irq() is stopping the
897 * thread via kthread_stop() after calling
898 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
899 * oneshot mask bit can be set. We cannot verify that as we
900 * cannot touch the oneshot mask at this point anymore as
901 * __setup_irq() might have given out currents thread_mask
902 * again.
903 */
904 task_work_cancel(current, irq_thread_dtor);
905 return 0;
906}
907
908/**
909 * irq_wake_thread - wake the irq thread for the action identified by dev_id
910 * @irq: Interrupt line
911 * @dev_id: Device identity for which the thread should be woken
912 *
913 */
914void irq_wake_thread(unsigned int irq, void *dev_id)
915{
916 struct irq_desc *desc = irq_to_desc(irq);
917 struct irqaction *action;
918 unsigned long flags;
919
920 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
921 return;
922
923 raw_spin_lock_irqsave(&desc->lock, flags);
924 for (action = desc->action; action; action = action->next) {
925 if (action->dev_id == dev_id) {
926 if (action->thread)
927 __irq_wake_thread(desc, action);
928 break;
929 }
930 }
931 raw_spin_unlock_irqrestore(&desc->lock, flags);
932}
933EXPORT_SYMBOL_GPL(irq_wake_thread);
934
935static void irq_setup_forced_threading(struct irqaction *new)
936{
937 if (!force_irqthreads)
938 return;
939 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
940 return;
941
942 new->flags |= IRQF_ONESHOT;
943
944 if (!new->thread_fn) {
945 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
946 new->thread_fn = new->handler;
947 new->handler = irq_default_primary_handler;
948 }
949}
950
951static int irq_request_resources(struct irq_desc *desc)
952{
953 struct irq_data *d = &desc->irq_data;
954 struct irq_chip *c = d->chip;
955
956 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
957}
958
959static void irq_release_resources(struct irq_desc *desc)
960{
961 struct irq_data *d = &desc->irq_data;
962 struct irq_chip *c = d->chip;
963
964 if (c->irq_release_resources)
965 c->irq_release_resources(d);
966}
967
968/*
969 * Internal function to register an irqaction - typically used to
970 * allocate special interrupts that are part of the architecture.
971 */
972static int
973__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
974{
975 struct irqaction *old, **old_ptr;
976 unsigned long flags, thread_mask = 0;
977 int ret, nested, shared = 0;
978 cpumask_var_t mask;
979
980 if (!desc)
981 return -EINVAL;
982
983 if (desc->irq_data.chip == &no_irq_chip)
984 return -ENOSYS;
985 if (!try_module_get(desc->owner))
986 return -ENODEV;
987
988 /*
989 * Check whether the interrupt nests into another interrupt
990 * thread.
991 */
992 nested = irq_settings_is_nested_thread(desc);
993 if (nested) {
994 if (!new->thread_fn) {
995 ret = -EINVAL;
996 goto out_mput;
997 }
998 /*
999 * Replace the primary handler which was provided from
1000 * the driver for non nested interrupt handling by the
1001 * dummy function which warns when called.
1002 */
1003 new->handler = irq_nested_primary_handler;
1004 } else {
1005 if (irq_settings_can_thread(desc))
1006 irq_setup_forced_threading(new);
1007 }
1008
1009 /*
1010 * Create a handler thread when a thread function is supplied
1011 * and the interrupt does not nest into another interrupt
1012 * thread.
1013 */
1014 if (new->thread_fn && !nested) {
1015 struct task_struct *t;
1016 static const struct sched_param param = {
1017 .sched_priority = MAX_USER_RT_PRIO/2,
1018 };
1019
1020 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1021 new->name);
1022 if (IS_ERR(t)) {
1023 ret = PTR_ERR(t);
1024 goto out_mput;
1025 }
1026
1027 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1028
1029 /*
1030 * We keep the reference to the task struct even if
1031 * the thread dies to avoid that the interrupt code
1032 * references an already freed task_struct.
1033 */
1034 get_task_struct(t);
1035 new->thread = t;
1036 /*
1037 * Tell the thread to set its affinity. This is
1038 * important for shared interrupt handlers as we do
1039 * not invoke setup_affinity() for the secondary
1040 * handlers as everything is already set up. Even for
1041 * interrupts marked with IRQF_NO_BALANCE this is
1042 * correct as we want the thread to move to the cpu(s)
1043 * on which the requesting code placed the interrupt.
1044 */
1045 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1046 }
1047
1048 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1049 ret = -ENOMEM;
1050 goto out_thread;
1051 }
1052
1053 /*
1054 * Drivers are often written to work w/o knowledge about the
1055 * underlying irq chip implementation, so a request for a
1056 * threaded irq without a primary hard irq context handler
1057 * requires the ONESHOT flag to be set. Some irq chips like
1058 * MSI based interrupts are per se one shot safe. Check the
1059 * chip flags, so we can avoid the unmask dance at the end of
1060 * the threaded handler for those.
1061 */
1062 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1063 new->flags &= ~IRQF_ONESHOT;
1064
1065 /*
1066 * The following block of code has to be executed atomically
1067 */
1068 raw_spin_lock_irqsave(&desc->lock, flags);
1069 old_ptr = &desc->action;
1070 old = *old_ptr;
1071 if (old) {
1072 /*
1073 * Can't share interrupts unless both agree to and are
1074 * the same type (level, edge, polarity). So both flag
1075 * fields must have IRQF_SHARED set and the bits which
1076 * set the trigger type must match. Also all must
1077 * agree on ONESHOT.
1078 */
1079 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1080 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1081 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1082 goto mismatch;
1083
1084 /* All handlers must agree on per-cpuness */
1085 if ((old->flags & IRQF_PERCPU) !=
1086 (new->flags & IRQF_PERCPU))
1087 goto mismatch;
1088
1089 /* add new interrupt at end of irq queue */
1090 do {
1091 /*
1092 * Or all existing action->thread_mask bits,
1093 * so we can find the next zero bit for this
1094 * new action.
1095 */
1096 thread_mask |= old->thread_mask;
1097 old_ptr = &old->next;
1098 old = *old_ptr;
1099 } while (old);
1100 shared = 1;
1101 }
1102
1103 /*
1104 * Setup the thread mask for this irqaction for ONESHOT. For
1105 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1106 * conditional in irq_wake_thread().
1107 */
1108 if (new->flags & IRQF_ONESHOT) {
1109 /*
1110 * Unlikely to have 32 resp 64 irqs sharing one line,
1111 * but who knows.
1112 */
1113 if (thread_mask == ~0UL) {
1114 ret = -EBUSY;
1115 goto out_mask;
1116 }
1117 /*
1118 * The thread_mask for the action is or'ed to
1119 * desc->thread_active to indicate that the
1120 * IRQF_ONESHOT thread handler has been woken, but not
1121 * yet finished. The bit is cleared when a thread
1122 * completes. When all threads of a shared interrupt
1123 * line have completed desc->threads_active becomes
1124 * zero and the interrupt line is unmasked. See
1125 * handle.c:irq_wake_thread() for further information.
1126 *
1127 * If no thread is woken by primary (hard irq context)
1128 * interrupt handlers, then desc->threads_active is
1129 * also checked for zero to unmask the irq line in the
1130 * affected hard irq flow handlers
1131 * (handle_[fasteoi|level]_irq).
1132 *
1133 * The new action gets the first zero bit of
1134 * thread_mask assigned. See the loop above which or's
1135 * all existing action->thread_mask bits.
1136 */
1137 new->thread_mask = 1 << ffz(thread_mask);
1138
1139 } else if (new->handler == irq_default_primary_handler &&
1140 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1141 /*
1142 * The interrupt was requested with handler = NULL, so
1143 * we use the default primary handler for it. But it
1144 * does not have the oneshot flag set. In combination
1145 * with level interrupts this is deadly, because the
1146 * default primary handler just wakes the thread, then
1147 * the irq lines is reenabled, but the device still
1148 * has the level irq asserted. Rinse and repeat....
1149 *
1150 * While this works for edge type interrupts, we play
1151 * it safe and reject unconditionally because we can't
1152 * say for sure which type this interrupt really
1153 * has. The type flags are unreliable as the
1154 * underlying chip implementation can override them.
1155 */
1156 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1157 irq);
1158 ret = -EINVAL;
1159 goto out_mask;
1160 }
1161
1162 if (!shared) {
1163 ret = irq_request_resources(desc);
1164 if (ret) {
1165 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1166 new->name, irq, desc->irq_data.chip->name);
1167 goto out_mask;
1168 }
1169
1170 init_waitqueue_head(&desc->wait_for_threads);
1171
1172 /* Setup the type (level, edge polarity) if configured: */
1173 if (new->flags & IRQF_TRIGGER_MASK) {
1174 ret = __irq_set_trigger(desc, irq,
1175 new->flags & IRQF_TRIGGER_MASK);
1176
1177 if (ret)
1178 goto out_mask;
1179 }
1180
1181 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1182 IRQS_ONESHOT | IRQS_WAITING);
1183 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1184
1185 if (new->flags & IRQF_PERCPU) {
1186 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1187 irq_settings_set_per_cpu(desc);
1188 }
1189
1190 if (new->flags & IRQF_ONESHOT)
1191 desc->istate |= IRQS_ONESHOT;
1192
1193 if (irq_settings_can_autoenable(desc))
1194 irq_startup(desc, true);
1195 else
1196 /* Undo nested disables: */
1197 desc->depth = 1;
1198
1199 /* Exclude IRQ from balancing if requested */
1200 if (new->flags & IRQF_NOBALANCING) {
1201 irq_settings_set_no_balancing(desc);
1202 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1203 }
1204
1205 /* Set default affinity mask once everything is setup */
1206 setup_affinity(irq, desc, mask);
1207
1208 } else if (new->flags & IRQF_TRIGGER_MASK) {
1209 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1210 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1211
1212 if (nmsk != omsk)
1213 /* hope the handler works with current trigger mode */
1214 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1215 irq, nmsk, omsk);
1216 }
1217
1218 new->irq = irq;
1219 *old_ptr = new;
1220
1221 /* Reset broken irq detection when installing new handler */
1222 desc->irq_count = 0;
1223 desc->irqs_unhandled = 0;
1224
1225 /*
1226 * Check whether we disabled the irq via the spurious handler
1227 * before. Reenable it and give it another chance.
1228 */
1229 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1230 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1231 __enable_irq(desc, irq, false);
1232 }
1233
1234 raw_spin_unlock_irqrestore(&desc->lock, flags);
1235
1236 /*
1237 * Strictly no need to wake it up, but hung_task complains
1238 * when no hard interrupt wakes the thread up.
1239 */
1240 if (new->thread)
1241 wake_up_process(new->thread);
1242
1243 register_irq_proc(irq, desc);
1244 new->dir = NULL;
1245 register_handler_proc(irq, new);
1246 free_cpumask_var(mask);
1247
1248 return 0;
1249
1250mismatch:
1251 if (!(new->flags & IRQF_PROBE_SHARED)) {
1252 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1253 irq, new->flags, new->name, old->flags, old->name);
1254#ifdef CONFIG_DEBUG_SHIRQ
1255 dump_stack();
1256#endif
1257 }
1258 ret = -EBUSY;
1259
1260out_mask:
1261 raw_spin_unlock_irqrestore(&desc->lock, flags);
1262 free_cpumask_var(mask);
1263
1264out_thread:
1265 if (new->thread) {
1266 struct task_struct *t = new->thread;
1267
1268 new->thread = NULL;
1269 kthread_stop(t);
1270 put_task_struct(t);
1271 }
1272out_mput:
1273 module_put(desc->owner);
1274 return ret;
1275}
1276
1277/**
1278 * setup_irq - setup an interrupt
1279 * @irq: Interrupt line to setup
1280 * @act: irqaction for the interrupt
1281 *
1282 * Used to statically setup interrupts in the early boot process.
1283 */
1284int setup_irq(unsigned int irq, struct irqaction *act)
1285{
1286 int retval;
1287 struct irq_desc *desc = irq_to_desc(irq);
1288
1289 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1290 return -EINVAL;
1291 chip_bus_lock(desc);
1292 retval = __setup_irq(irq, desc, act);
1293 chip_bus_sync_unlock(desc);
1294
1295 return retval;
1296}
1297EXPORT_SYMBOL_GPL(setup_irq);
1298
1299/*
1300 * Internal function to unregister an irqaction - used to free
1301 * regular and special interrupts that are part of the architecture.
1302 */
1303static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1304{
1305 struct irq_desc *desc = irq_to_desc(irq);
1306 struct irqaction *action, **action_ptr;
1307 unsigned long flags;
1308
1309 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1310
1311 if (!desc)
1312 return NULL;
1313
1314 raw_spin_lock_irqsave(&desc->lock, flags);
1315
1316 /*
1317 * There can be multiple actions per IRQ descriptor, find the right
1318 * one based on the dev_id:
1319 */
1320 action_ptr = &desc->action;
1321 for (;;) {
1322 action = *action_ptr;
1323
1324 if (!action) {
1325 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1326 raw_spin_unlock_irqrestore(&desc->lock, flags);
1327
1328 return NULL;
1329 }
1330
1331 if (action->dev_id == dev_id)
1332 break;
1333 action_ptr = &action->next;
1334 }
1335
1336 /* Found it - now remove it from the list of entries: */
1337 *action_ptr = action->next;
1338
1339 /* If this was the last handler, shut down the IRQ line: */
1340 if (!desc->action) {
1341 irq_shutdown(desc);
1342 irq_release_resources(desc);
1343 }
1344
1345#ifdef CONFIG_SMP
1346 /* make sure affinity_hint is cleaned up */
1347 if (WARN_ON_ONCE(desc->affinity_hint))
1348 desc->affinity_hint = NULL;
1349#endif
1350
1351 raw_spin_unlock_irqrestore(&desc->lock, flags);
1352
1353 unregister_handler_proc(irq, action);
1354
1355 /* Make sure it's not being used on another CPU: */
1356 synchronize_irq(irq);
1357
1358#ifdef CONFIG_DEBUG_SHIRQ
1359 /*
1360 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1361 * event to happen even now it's being freed, so let's make sure that
1362 * is so by doing an extra call to the handler ....
1363 *
1364 * ( We do this after actually deregistering it, to make sure that a
1365 * 'real' IRQ doesn't run in * parallel with our fake. )
1366 */
1367 if (action->flags & IRQF_SHARED) {
1368 local_irq_save(flags);
1369 action->handler(irq, dev_id);
1370 local_irq_restore(flags);
1371 }
1372#endif
1373
1374 if (action->thread) {
1375 kthread_stop(action->thread);
1376 put_task_struct(action->thread);
1377 }
1378
1379 module_put(desc->owner);
1380 return action;
1381}
1382
1383/**
1384 * remove_irq - free an interrupt
1385 * @irq: Interrupt line to free
1386 * @act: irqaction for the interrupt
1387 *
1388 * Used to remove interrupts statically setup by the early boot process.
1389 */
1390void remove_irq(unsigned int irq, struct irqaction *act)
1391{
1392 struct irq_desc *desc = irq_to_desc(irq);
1393
1394 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1395 __free_irq(irq, act->dev_id);
1396}
1397EXPORT_SYMBOL_GPL(remove_irq);
1398
1399/**
1400 * free_irq - free an interrupt allocated with request_irq
1401 * @irq: Interrupt line to free
1402 * @dev_id: Device identity to free
1403 *
1404 * Remove an interrupt handler. The handler is removed and if the
1405 * interrupt line is no longer in use by any driver it is disabled.
1406 * On a shared IRQ the caller must ensure the interrupt is disabled
1407 * on the card it drives before calling this function. The function
1408 * does not return until any executing interrupts for this IRQ
1409 * have completed.
1410 *
1411 * This function must not be called from interrupt context.
1412 */
1413void free_irq(unsigned int irq, void *dev_id)
1414{
1415 struct irq_desc *desc = irq_to_desc(irq);
1416
1417 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1418 return;
1419
1420#ifdef CONFIG_SMP
1421 if (WARN_ON(desc->affinity_notify))
1422 desc->affinity_notify = NULL;
1423#endif
1424
1425 chip_bus_lock(desc);
1426 kfree(__free_irq(irq, dev_id));
1427 chip_bus_sync_unlock(desc);
1428}
1429EXPORT_SYMBOL(free_irq);
1430
1431/**
1432 * request_threaded_irq - allocate an interrupt line
1433 * @irq: Interrupt line to allocate
1434 * @handler: Function to be called when the IRQ occurs.
1435 * Primary handler for threaded interrupts
1436 * If NULL and thread_fn != NULL the default
1437 * primary handler is installed
1438 * @thread_fn: Function called from the irq handler thread
1439 * If NULL, no irq thread is created
1440 * @irqflags: Interrupt type flags
1441 * @devname: An ascii name for the claiming device
1442 * @dev_id: A cookie passed back to the handler function
1443 *
1444 * This call allocates interrupt resources and enables the
1445 * interrupt line and IRQ handling. From the point this
1446 * call is made your handler function may be invoked. Since
1447 * your handler function must clear any interrupt the board
1448 * raises, you must take care both to initialise your hardware
1449 * and to set up the interrupt handler in the right order.
1450 *
1451 * If you want to set up a threaded irq handler for your device
1452 * then you need to supply @handler and @thread_fn. @handler is
1453 * still called in hard interrupt context and has to check
1454 * whether the interrupt originates from the device. If yes it
1455 * needs to disable the interrupt on the device and return
1456 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1457 * @thread_fn. This split handler design is necessary to support
1458 * shared interrupts.
1459 *
1460 * Dev_id must be globally unique. Normally the address of the
1461 * device data structure is used as the cookie. Since the handler
1462 * receives this value it makes sense to use it.
1463 *
1464 * If your interrupt is shared you must pass a non NULL dev_id
1465 * as this is required when freeing the interrupt.
1466 *
1467 * Flags:
1468 *
1469 * IRQF_SHARED Interrupt is shared
1470 * IRQF_TRIGGER_* Specify active edge(s) or level
1471 *
1472 */
1473int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1474 irq_handler_t thread_fn, unsigned long irqflags,
1475 const char *devname, void *dev_id)
1476{
1477 struct irqaction *action;
1478 struct irq_desc *desc;
1479 int retval;
1480
1481 /*
1482 * Sanity-check: shared interrupts must pass in a real dev-ID,
1483 * otherwise we'll have trouble later trying to figure out
1484 * which interrupt is which (messes up the interrupt freeing
1485 * logic etc).
1486 */
1487 if ((irqflags & IRQF_SHARED) && !dev_id)
1488 return -EINVAL;
1489
1490 desc = irq_to_desc(irq);
1491 if (!desc)
1492 return -EINVAL;
1493
1494 if (!irq_settings_can_request(desc) ||
1495 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1496 return -EINVAL;
1497
1498 if (!handler) {
1499 if (!thread_fn)
1500 return -EINVAL;
1501 handler = irq_default_primary_handler;
1502 }
1503
1504 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1505 if (!action)
1506 return -ENOMEM;
1507
1508 action->handler = handler;
1509 action->thread_fn = thread_fn;
1510 action->flags = irqflags;
1511 action->name = devname;
1512 action->dev_id = dev_id;
1513
1514 chip_bus_lock(desc);
1515 retval = __setup_irq(irq, desc, action);
1516 chip_bus_sync_unlock(desc);
1517
1518 if (retval)
1519 kfree(action);
1520
1521#ifdef CONFIG_DEBUG_SHIRQ_FIXME
1522 if (!retval && (irqflags & IRQF_SHARED)) {
1523 /*
1524 * It's a shared IRQ -- the driver ought to be prepared for it
1525 * to happen immediately, so let's make sure....
1526 * We disable the irq to make sure that a 'real' IRQ doesn't
1527 * run in parallel with our fake.
1528 */
1529 unsigned long flags;
1530
1531 disable_irq(irq);
1532 local_irq_save(flags);
1533
1534 handler(irq, dev_id);
1535
1536 local_irq_restore(flags);
1537 enable_irq(irq);
1538 }
1539#endif
1540 return retval;
1541}
1542EXPORT_SYMBOL(request_threaded_irq);
1543
1544/**
1545 * request_any_context_irq - allocate an interrupt line
1546 * @irq: Interrupt line to allocate
1547 * @handler: Function to be called when the IRQ occurs.
1548 * Threaded handler for threaded interrupts.
1549 * @flags: Interrupt type flags
1550 * @name: An ascii name for the claiming device
1551 * @dev_id: A cookie passed back to the handler function
1552 *
1553 * This call allocates interrupt resources and enables the
1554 * interrupt line and IRQ handling. It selects either a
1555 * hardirq or threaded handling method depending on the
1556 * context.
1557 *
1558 * On failure, it returns a negative value. On success,
1559 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1560 */
1561int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1562 unsigned long flags, const char *name, void *dev_id)
1563{
1564 struct irq_desc *desc = irq_to_desc(irq);
1565 int ret;
1566
1567 if (!desc)
1568 return -EINVAL;
1569
1570 if (irq_settings_is_nested_thread(desc)) {
1571 ret = request_threaded_irq(irq, NULL, handler,
1572 flags, name, dev_id);
1573 return !ret ? IRQC_IS_NESTED : ret;
1574 }
1575
1576 ret = request_irq(irq, handler, flags, name, dev_id);
1577 return !ret ? IRQC_IS_HARDIRQ : ret;
1578}
1579EXPORT_SYMBOL_GPL(request_any_context_irq);
1580
1581void enable_percpu_irq(unsigned int irq, unsigned int type)
1582{
1583 unsigned int cpu = smp_processor_id();
1584 unsigned long flags;
1585 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1586
1587 if (!desc)
1588 return;
1589
1590 type &= IRQ_TYPE_SENSE_MASK;
1591 if (type != IRQ_TYPE_NONE) {
1592 int ret;
1593
1594 ret = __irq_set_trigger(desc, irq, type);
1595
1596 if (ret) {
1597 WARN(1, "failed to set type for IRQ%d\n", irq);
1598 goto out;
1599 }
1600 }
1601
1602 irq_percpu_enable(desc, cpu);
1603out:
1604 irq_put_desc_unlock(desc, flags);
1605}
1606EXPORT_SYMBOL_GPL(enable_percpu_irq);
1607
1608void disable_percpu_irq(unsigned int irq)
1609{
1610 unsigned int cpu = smp_processor_id();
1611 unsigned long flags;
1612 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1613
1614 if (!desc)
1615 return;
1616
1617 irq_percpu_disable(desc, cpu);
1618 irq_put_desc_unlock(desc, flags);
1619}
1620EXPORT_SYMBOL_GPL(disable_percpu_irq);
1621
1622/*
1623 * Internal function to unregister a percpu irqaction.
1624 */
1625static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1626{
1627 struct irq_desc *desc = irq_to_desc(irq);
1628 struct irqaction *action;
1629 unsigned long flags;
1630
1631 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1632
1633 if (!desc)
1634 return NULL;
1635
1636 raw_spin_lock_irqsave(&desc->lock, flags);
1637
1638 action = desc->action;
1639 if (!action || action->percpu_dev_id != dev_id) {
1640 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1641 goto bad;
1642 }
1643
1644 if (!cpumask_empty(desc->percpu_enabled)) {
1645 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1646 irq, cpumask_first(desc->percpu_enabled));
1647 goto bad;
1648 }
1649
1650 /* Found it - now remove it from the list of entries: */
1651 desc->action = NULL;
1652
1653 raw_spin_unlock_irqrestore(&desc->lock, flags);
1654
1655 unregister_handler_proc(irq, action);
1656
1657 module_put(desc->owner);
1658 return action;
1659
1660bad:
1661 raw_spin_unlock_irqrestore(&desc->lock, flags);
1662 return NULL;
1663}
1664
1665/**
1666 * remove_percpu_irq - free a per-cpu interrupt
1667 * @irq: Interrupt line to free
1668 * @act: irqaction for the interrupt
1669 *
1670 * Used to remove interrupts statically setup by the early boot process.
1671 */
1672void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1673{
1674 struct irq_desc *desc = irq_to_desc(irq);
1675
1676 if (desc && irq_settings_is_per_cpu_devid(desc))
1677 __free_percpu_irq(irq, act->percpu_dev_id);
1678}
1679
1680/**
1681 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1682 * @irq: Interrupt line to free
1683 * @dev_id: Device identity to free
1684 *
1685 * Remove a percpu interrupt handler. The handler is removed, but
1686 * the interrupt line is not disabled. This must be done on each
1687 * CPU before calling this function. The function does not return
1688 * until any executing interrupts for this IRQ have completed.
1689 *
1690 * This function must not be called from interrupt context.
1691 */
1692void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1693{
1694 struct irq_desc *desc = irq_to_desc(irq);
1695
1696 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1697 return;
1698
1699 chip_bus_lock(desc);
1700 kfree(__free_percpu_irq(irq, dev_id));
1701 chip_bus_sync_unlock(desc);
1702}
1703
1704/**
1705 * setup_percpu_irq - setup a per-cpu interrupt
1706 * @irq: Interrupt line to setup
1707 * @act: irqaction for the interrupt
1708 *
1709 * Used to statically setup per-cpu interrupts in the early boot process.
1710 */
1711int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1712{
1713 struct irq_desc *desc = irq_to_desc(irq);
1714 int retval;
1715
1716 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1717 return -EINVAL;
1718 chip_bus_lock(desc);
1719 retval = __setup_irq(irq, desc, act);
1720 chip_bus_sync_unlock(desc);
1721
1722 return retval;
1723}
1724
1725/**
1726 * request_percpu_irq - allocate a percpu interrupt line
1727 * @irq: Interrupt line to allocate
1728 * @handler: Function to be called when the IRQ occurs.
1729 * @devname: An ascii name for the claiming device
1730 * @dev_id: A percpu cookie passed back to the handler function
1731 *
1732 * This call allocates interrupt resources, but doesn't
1733 * automatically enable the interrupt. It has to be done on each
1734 * CPU using enable_percpu_irq().
1735 *
1736 * Dev_id must be globally unique. It is a per-cpu variable, and
1737 * the handler gets called with the interrupted CPU's instance of
1738 * that variable.
1739 */
1740int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1741 const char *devname, void __percpu *dev_id)
1742{
1743 struct irqaction *action;
1744 struct irq_desc *desc;
1745 int retval;
1746
1747 if (!dev_id)
1748 return -EINVAL;
1749
1750 desc = irq_to_desc(irq);
1751 if (!desc || !irq_settings_can_request(desc) ||
1752 !irq_settings_is_per_cpu_devid(desc))
1753 return -EINVAL;
1754
1755 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1756 if (!action)
1757 return -ENOMEM;
1758
1759 action->handler = handler;
1760 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1761 action->name = devname;
1762 action->percpu_dev_id = dev_id;
1763
1764 chip_bus_lock(desc);
1765 retval = __setup_irq(irq, desc, action);
1766 chip_bus_sync_unlock(desc);
1767
1768 if (retval)
1769 kfree(action);
1770
1771 return retval;
1772}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/slab.h>
17#include <linux/sched.h>
18#include <linux/sched/rt.h>
19#include <linux/sched/task.h>
20#include <uapi/linux/sched/types.h>
21#include <linux/task_work.h>
22
23#include "internals.h"
24
25#ifdef CONFIG_IRQ_FORCED_THREADING
26__read_mostly bool force_irqthreads;
27
28static int __init setup_forced_irqthreads(char *arg)
29{
30 force_irqthreads = true;
31 return 0;
32}
33early_param("threadirqs", setup_forced_irqthreads);
34#endif
35
36static void __synchronize_hardirq(struct irq_desc *desc)
37{
38 bool inprogress;
39
40 do {
41 unsigned long flags;
42
43 /*
44 * Wait until we're out of the critical section. This might
45 * give the wrong answer due to the lack of memory barriers.
46 */
47 while (irqd_irq_inprogress(&desc->irq_data))
48 cpu_relax();
49
50 /* Ok, that indicated we're done: double-check carefully. */
51 raw_spin_lock_irqsave(&desc->lock, flags);
52 inprogress = irqd_irq_inprogress(&desc->irq_data);
53 raw_spin_unlock_irqrestore(&desc->lock, flags);
54
55 /* Oops, that failed? */
56 } while (inprogress);
57}
58
59/**
60 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
61 * @irq: interrupt number to wait for
62 *
63 * This function waits for any pending hard IRQ handlers for this
64 * interrupt to complete before returning. If you use this
65 * function while holding a resource the IRQ handler may need you
66 * will deadlock. It does not take associated threaded handlers
67 * into account.
68 *
69 * Do not use this for shutdown scenarios where you must be sure
70 * that all parts (hardirq and threaded handler) have completed.
71 *
72 * Returns: false if a threaded handler is active.
73 *
74 * This function may be called - with care - from IRQ context.
75 */
76bool synchronize_hardirq(unsigned int irq)
77{
78 struct irq_desc *desc = irq_to_desc(irq);
79
80 if (desc) {
81 __synchronize_hardirq(desc);
82 return !atomic_read(&desc->threads_active);
83 }
84
85 return true;
86}
87EXPORT_SYMBOL(synchronize_hardirq);
88
89/**
90 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
91 * @irq: interrupt number to wait for
92 *
93 * This function waits for any pending IRQ handlers for this interrupt
94 * to complete before returning. If you use this function while
95 * holding a resource the IRQ handler may need you will deadlock.
96 *
97 * This function may be called - with care - from IRQ context.
98 */
99void synchronize_irq(unsigned int irq)
100{
101 struct irq_desc *desc = irq_to_desc(irq);
102
103 if (desc) {
104 __synchronize_hardirq(desc);
105 /*
106 * We made sure that no hardirq handler is
107 * running. Now verify that no threaded handlers are
108 * active.
109 */
110 wait_event(desc->wait_for_threads,
111 !atomic_read(&desc->threads_active));
112 }
113}
114EXPORT_SYMBOL(synchronize_irq);
115
116#ifdef CONFIG_SMP
117cpumask_var_t irq_default_affinity;
118
119static bool __irq_can_set_affinity(struct irq_desc *desc)
120{
121 if (!desc || !irqd_can_balance(&desc->irq_data) ||
122 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
123 return false;
124 return true;
125}
126
127/**
128 * irq_can_set_affinity - Check if the affinity of a given irq can be set
129 * @irq: Interrupt to check
130 *
131 */
132int irq_can_set_affinity(unsigned int irq)
133{
134 return __irq_can_set_affinity(irq_to_desc(irq));
135}
136
137/**
138 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
139 * @irq: Interrupt to check
140 *
141 * Like irq_can_set_affinity() above, but additionally checks for the
142 * AFFINITY_MANAGED flag.
143 */
144bool irq_can_set_affinity_usr(unsigned int irq)
145{
146 struct irq_desc *desc = irq_to_desc(irq);
147
148 return __irq_can_set_affinity(desc) &&
149 !irqd_affinity_is_managed(&desc->irq_data);
150}
151
152/**
153 * irq_set_thread_affinity - Notify irq threads to adjust affinity
154 * @desc: irq descriptor which has affitnity changed
155 *
156 * We just set IRQTF_AFFINITY and delegate the affinity setting
157 * to the interrupt thread itself. We can not call
158 * set_cpus_allowed_ptr() here as we hold desc->lock and this
159 * code can be called from hard interrupt context.
160 */
161void irq_set_thread_affinity(struct irq_desc *desc)
162{
163 struct irqaction *action;
164
165 for_each_action_of_desc(desc, action)
166 if (action->thread)
167 set_bit(IRQTF_AFFINITY, &action->thread_flags);
168}
169
170static void irq_validate_effective_affinity(struct irq_data *data)
171{
172#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
173 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
174 struct irq_chip *chip = irq_data_get_irq_chip(data);
175
176 if (!cpumask_empty(m))
177 return;
178 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
179 chip->name, data->irq);
180#endif
181}
182
183int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
184 bool force)
185{
186 struct irq_desc *desc = irq_data_to_desc(data);
187 struct irq_chip *chip = irq_data_get_irq_chip(data);
188 int ret;
189
190 if (!chip || !chip->irq_set_affinity)
191 return -EINVAL;
192
193 ret = chip->irq_set_affinity(data, mask, force);
194 switch (ret) {
195 case IRQ_SET_MASK_OK:
196 case IRQ_SET_MASK_OK_DONE:
197 cpumask_copy(desc->irq_common_data.affinity, mask);
198 case IRQ_SET_MASK_OK_NOCOPY:
199 irq_validate_effective_affinity(data);
200 irq_set_thread_affinity(desc);
201 ret = 0;
202 }
203
204 return ret;
205}
206
207int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
208 bool force)
209{
210 struct irq_chip *chip = irq_data_get_irq_chip(data);
211 struct irq_desc *desc = irq_data_to_desc(data);
212 int ret = 0;
213
214 if (!chip || !chip->irq_set_affinity)
215 return -EINVAL;
216
217 if (irq_can_move_pcntxt(data)) {
218 ret = irq_do_set_affinity(data, mask, force);
219 } else {
220 irqd_set_move_pending(data);
221 irq_copy_pending(desc, mask);
222 }
223
224 if (desc->affinity_notify) {
225 kref_get(&desc->affinity_notify->kref);
226 schedule_work(&desc->affinity_notify->work);
227 }
228 irqd_set(data, IRQD_AFFINITY_SET);
229
230 return ret;
231}
232
233int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
234{
235 struct irq_desc *desc = irq_to_desc(irq);
236 unsigned long flags;
237 int ret;
238
239 if (!desc)
240 return -EINVAL;
241
242 raw_spin_lock_irqsave(&desc->lock, flags);
243 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
244 raw_spin_unlock_irqrestore(&desc->lock, flags);
245 return ret;
246}
247
248int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
249{
250 unsigned long flags;
251 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
252
253 if (!desc)
254 return -EINVAL;
255 desc->affinity_hint = m;
256 irq_put_desc_unlock(desc, flags);
257 /* set the initial affinity to prevent every interrupt being on CPU0 */
258 if (m)
259 __irq_set_affinity(irq, m, false);
260 return 0;
261}
262EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
263
264static void irq_affinity_notify(struct work_struct *work)
265{
266 struct irq_affinity_notify *notify =
267 container_of(work, struct irq_affinity_notify, work);
268 struct irq_desc *desc = irq_to_desc(notify->irq);
269 cpumask_var_t cpumask;
270 unsigned long flags;
271
272 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
273 goto out;
274
275 raw_spin_lock_irqsave(&desc->lock, flags);
276 if (irq_move_pending(&desc->irq_data))
277 irq_get_pending(cpumask, desc);
278 else
279 cpumask_copy(cpumask, desc->irq_common_data.affinity);
280 raw_spin_unlock_irqrestore(&desc->lock, flags);
281
282 notify->notify(notify, cpumask);
283
284 free_cpumask_var(cpumask);
285out:
286 kref_put(¬ify->kref, notify->release);
287}
288
289/**
290 * irq_set_affinity_notifier - control notification of IRQ affinity changes
291 * @irq: Interrupt for which to enable/disable notification
292 * @notify: Context for notification, or %NULL to disable
293 * notification. Function pointers must be initialised;
294 * the other fields will be initialised by this function.
295 *
296 * Must be called in process context. Notification may only be enabled
297 * after the IRQ is allocated and must be disabled before the IRQ is
298 * freed using free_irq().
299 */
300int
301irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
302{
303 struct irq_desc *desc = irq_to_desc(irq);
304 struct irq_affinity_notify *old_notify;
305 unsigned long flags;
306
307 /* The release function is promised process context */
308 might_sleep();
309
310 if (!desc)
311 return -EINVAL;
312
313 /* Complete initialisation of *notify */
314 if (notify) {
315 notify->irq = irq;
316 kref_init(¬ify->kref);
317 INIT_WORK(¬ify->work, irq_affinity_notify);
318 }
319
320 raw_spin_lock_irqsave(&desc->lock, flags);
321 old_notify = desc->affinity_notify;
322 desc->affinity_notify = notify;
323 raw_spin_unlock_irqrestore(&desc->lock, flags);
324
325 if (old_notify)
326 kref_put(&old_notify->kref, old_notify->release);
327
328 return 0;
329}
330EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
331
332#ifndef CONFIG_AUTO_IRQ_AFFINITY
333/*
334 * Generic version of the affinity autoselector.
335 */
336int irq_setup_affinity(struct irq_desc *desc)
337{
338 struct cpumask *set = irq_default_affinity;
339 int ret, node = irq_desc_get_node(desc);
340 static DEFINE_RAW_SPINLOCK(mask_lock);
341 static struct cpumask mask;
342
343 /* Excludes PER_CPU and NO_BALANCE interrupts */
344 if (!__irq_can_set_affinity(desc))
345 return 0;
346
347 raw_spin_lock(&mask_lock);
348 /*
349 * Preserve the managed affinity setting and a userspace affinity
350 * setup, but make sure that one of the targets is online.
351 */
352 if (irqd_affinity_is_managed(&desc->irq_data) ||
353 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
354 if (cpumask_intersects(desc->irq_common_data.affinity,
355 cpu_online_mask))
356 set = desc->irq_common_data.affinity;
357 else
358 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
359 }
360
361 cpumask_and(&mask, cpu_online_mask, set);
362 if (node != NUMA_NO_NODE) {
363 const struct cpumask *nodemask = cpumask_of_node(node);
364
365 /* make sure at least one of the cpus in nodemask is online */
366 if (cpumask_intersects(&mask, nodemask))
367 cpumask_and(&mask, &mask, nodemask);
368 }
369 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
370 raw_spin_unlock(&mask_lock);
371 return ret;
372}
373#else
374/* Wrapper for ALPHA specific affinity selector magic */
375int irq_setup_affinity(struct irq_desc *desc)
376{
377 return irq_select_affinity(irq_desc_get_irq(desc));
378}
379#endif
380
381/*
382 * Called when a bogus affinity is set via /proc/irq
383 */
384int irq_select_affinity_usr(unsigned int irq)
385{
386 struct irq_desc *desc = irq_to_desc(irq);
387 unsigned long flags;
388 int ret;
389
390 raw_spin_lock_irqsave(&desc->lock, flags);
391 ret = irq_setup_affinity(desc);
392 raw_spin_unlock_irqrestore(&desc->lock, flags);
393 return ret;
394}
395#endif
396
397/**
398 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
399 * @irq: interrupt number to set affinity
400 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
401 * specific data for percpu_devid interrupts
402 *
403 * This function uses the vCPU specific data to set the vCPU
404 * affinity for an irq. The vCPU specific data is passed from
405 * outside, such as KVM. One example code path is as below:
406 * KVM -> IOMMU -> irq_set_vcpu_affinity().
407 */
408int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
409{
410 unsigned long flags;
411 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
412 struct irq_data *data;
413 struct irq_chip *chip;
414 int ret = -ENOSYS;
415
416 if (!desc)
417 return -EINVAL;
418
419 data = irq_desc_get_irq_data(desc);
420 do {
421 chip = irq_data_get_irq_chip(data);
422 if (chip && chip->irq_set_vcpu_affinity)
423 break;
424#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
425 data = data->parent_data;
426#else
427 data = NULL;
428#endif
429 } while (data);
430
431 if (data)
432 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
433 irq_put_desc_unlock(desc, flags);
434
435 return ret;
436}
437EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
438
439void __disable_irq(struct irq_desc *desc)
440{
441 if (!desc->depth++)
442 irq_disable(desc);
443}
444
445static int __disable_irq_nosync(unsigned int irq)
446{
447 unsigned long flags;
448 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
449
450 if (!desc)
451 return -EINVAL;
452 __disable_irq(desc);
453 irq_put_desc_busunlock(desc, flags);
454 return 0;
455}
456
457/**
458 * disable_irq_nosync - disable an irq without waiting
459 * @irq: Interrupt to disable
460 *
461 * Disable the selected interrupt line. Disables and Enables are
462 * nested.
463 * Unlike disable_irq(), this function does not ensure existing
464 * instances of the IRQ handler have completed before returning.
465 *
466 * This function may be called from IRQ context.
467 */
468void disable_irq_nosync(unsigned int irq)
469{
470 __disable_irq_nosync(irq);
471}
472EXPORT_SYMBOL(disable_irq_nosync);
473
474/**
475 * disable_irq - disable an irq and wait for completion
476 * @irq: Interrupt to disable
477 *
478 * Disable the selected interrupt line. Enables and Disables are
479 * nested.
480 * This function waits for any pending IRQ handlers for this interrupt
481 * to complete before returning. If you use this function while
482 * holding a resource the IRQ handler may need you will deadlock.
483 *
484 * This function may be called - with care - from IRQ context.
485 */
486void disable_irq(unsigned int irq)
487{
488 if (!__disable_irq_nosync(irq))
489 synchronize_irq(irq);
490}
491EXPORT_SYMBOL(disable_irq);
492
493/**
494 * disable_hardirq - disables an irq and waits for hardirq completion
495 * @irq: Interrupt to disable
496 *
497 * Disable the selected interrupt line. Enables and Disables are
498 * nested.
499 * This function waits for any pending hard IRQ handlers for this
500 * interrupt to complete before returning. If you use this function while
501 * holding a resource the hard IRQ handler may need you will deadlock.
502 *
503 * When used to optimistically disable an interrupt from atomic context
504 * the return value must be checked.
505 *
506 * Returns: false if a threaded handler is active.
507 *
508 * This function may be called - with care - from IRQ context.
509 */
510bool disable_hardirq(unsigned int irq)
511{
512 if (!__disable_irq_nosync(irq))
513 return synchronize_hardirq(irq);
514
515 return false;
516}
517EXPORT_SYMBOL_GPL(disable_hardirq);
518
519void __enable_irq(struct irq_desc *desc)
520{
521 switch (desc->depth) {
522 case 0:
523 err_out:
524 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
525 irq_desc_get_irq(desc));
526 break;
527 case 1: {
528 if (desc->istate & IRQS_SUSPENDED)
529 goto err_out;
530 /* Prevent probing on this irq: */
531 irq_settings_set_noprobe(desc);
532 /*
533 * Call irq_startup() not irq_enable() here because the
534 * interrupt might be marked NOAUTOEN. So irq_startup()
535 * needs to be invoked when it gets enabled the first
536 * time. If it was already started up, then irq_startup()
537 * will invoke irq_enable() under the hood.
538 */
539 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
540 break;
541 }
542 default:
543 desc->depth--;
544 }
545}
546
547/**
548 * enable_irq - enable handling of an irq
549 * @irq: Interrupt to enable
550 *
551 * Undoes the effect of one call to disable_irq(). If this
552 * matches the last disable, processing of interrupts on this
553 * IRQ line is re-enabled.
554 *
555 * This function may be called from IRQ context only when
556 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
557 */
558void enable_irq(unsigned int irq)
559{
560 unsigned long flags;
561 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
562
563 if (!desc)
564 return;
565 if (WARN(!desc->irq_data.chip,
566 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
567 goto out;
568
569 __enable_irq(desc);
570out:
571 irq_put_desc_busunlock(desc, flags);
572}
573EXPORT_SYMBOL(enable_irq);
574
575static int set_irq_wake_real(unsigned int irq, unsigned int on)
576{
577 struct irq_desc *desc = irq_to_desc(irq);
578 int ret = -ENXIO;
579
580 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
581 return 0;
582
583 if (desc->irq_data.chip->irq_set_wake)
584 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
585
586 return ret;
587}
588
589/**
590 * irq_set_irq_wake - control irq power management wakeup
591 * @irq: interrupt to control
592 * @on: enable/disable power management wakeup
593 *
594 * Enable/disable power management wakeup mode, which is
595 * disabled by default. Enables and disables must match,
596 * just as they match for non-wakeup mode support.
597 *
598 * Wakeup mode lets this IRQ wake the system from sleep
599 * states like "suspend to RAM".
600 */
601int irq_set_irq_wake(unsigned int irq, unsigned int on)
602{
603 unsigned long flags;
604 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
605 int ret = 0;
606
607 if (!desc)
608 return -EINVAL;
609
610 /* wakeup-capable irqs can be shared between drivers that
611 * don't need to have the same sleep mode behaviors.
612 */
613 if (on) {
614 if (desc->wake_depth++ == 0) {
615 ret = set_irq_wake_real(irq, on);
616 if (ret)
617 desc->wake_depth = 0;
618 else
619 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
620 }
621 } else {
622 if (desc->wake_depth == 0) {
623 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
624 } else if (--desc->wake_depth == 0) {
625 ret = set_irq_wake_real(irq, on);
626 if (ret)
627 desc->wake_depth = 1;
628 else
629 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
630 }
631 }
632 irq_put_desc_busunlock(desc, flags);
633 return ret;
634}
635EXPORT_SYMBOL(irq_set_irq_wake);
636
637/*
638 * Internal function that tells the architecture code whether a
639 * particular irq has been exclusively allocated or is available
640 * for driver use.
641 */
642int can_request_irq(unsigned int irq, unsigned long irqflags)
643{
644 unsigned long flags;
645 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
646 int canrequest = 0;
647
648 if (!desc)
649 return 0;
650
651 if (irq_settings_can_request(desc)) {
652 if (!desc->action ||
653 irqflags & desc->action->flags & IRQF_SHARED)
654 canrequest = 1;
655 }
656 irq_put_desc_unlock(desc, flags);
657 return canrequest;
658}
659
660int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
661{
662 struct irq_chip *chip = desc->irq_data.chip;
663 int ret, unmask = 0;
664
665 if (!chip || !chip->irq_set_type) {
666 /*
667 * IRQF_TRIGGER_* but the PIC does not support multiple
668 * flow-types?
669 */
670 pr_debug("No set_type function for IRQ %d (%s)\n",
671 irq_desc_get_irq(desc),
672 chip ? (chip->name ? : "unknown") : "unknown");
673 return 0;
674 }
675
676 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
677 if (!irqd_irq_masked(&desc->irq_data))
678 mask_irq(desc);
679 if (!irqd_irq_disabled(&desc->irq_data))
680 unmask = 1;
681 }
682
683 /* Mask all flags except trigger mode */
684 flags &= IRQ_TYPE_SENSE_MASK;
685 ret = chip->irq_set_type(&desc->irq_data, flags);
686
687 switch (ret) {
688 case IRQ_SET_MASK_OK:
689 case IRQ_SET_MASK_OK_DONE:
690 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
691 irqd_set(&desc->irq_data, flags);
692
693 case IRQ_SET_MASK_OK_NOCOPY:
694 flags = irqd_get_trigger_type(&desc->irq_data);
695 irq_settings_set_trigger_mask(desc, flags);
696 irqd_clear(&desc->irq_data, IRQD_LEVEL);
697 irq_settings_clr_level(desc);
698 if (flags & IRQ_TYPE_LEVEL_MASK) {
699 irq_settings_set_level(desc);
700 irqd_set(&desc->irq_data, IRQD_LEVEL);
701 }
702
703 ret = 0;
704 break;
705 default:
706 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
707 flags, irq_desc_get_irq(desc), chip->irq_set_type);
708 }
709 if (unmask)
710 unmask_irq(desc);
711 return ret;
712}
713
714#ifdef CONFIG_HARDIRQS_SW_RESEND
715int irq_set_parent(int irq, int parent_irq)
716{
717 unsigned long flags;
718 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
719
720 if (!desc)
721 return -EINVAL;
722
723 desc->parent_irq = parent_irq;
724
725 irq_put_desc_unlock(desc, flags);
726 return 0;
727}
728EXPORT_SYMBOL_GPL(irq_set_parent);
729#endif
730
731/*
732 * Default primary interrupt handler for threaded interrupts. Is
733 * assigned as primary handler when request_threaded_irq is called
734 * with handler == NULL. Useful for oneshot interrupts.
735 */
736static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
737{
738 return IRQ_WAKE_THREAD;
739}
740
741/*
742 * Primary handler for nested threaded interrupts. Should never be
743 * called.
744 */
745static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
746{
747 WARN(1, "Primary handler called for nested irq %d\n", irq);
748 return IRQ_NONE;
749}
750
751static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
752{
753 WARN(1, "Secondary action handler called for irq %d\n", irq);
754 return IRQ_NONE;
755}
756
757static int irq_wait_for_interrupt(struct irqaction *action)
758{
759 set_current_state(TASK_INTERRUPTIBLE);
760
761 while (!kthread_should_stop()) {
762
763 if (test_and_clear_bit(IRQTF_RUNTHREAD,
764 &action->thread_flags)) {
765 __set_current_state(TASK_RUNNING);
766 return 0;
767 }
768 schedule();
769 set_current_state(TASK_INTERRUPTIBLE);
770 }
771 __set_current_state(TASK_RUNNING);
772 return -1;
773}
774
775/*
776 * Oneshot interrupts keep the irq line masked until the threaded
777 * handler finished. unmask if the interrupt has not been disabled and
778 * is marked MASKED.
779 */
780static void irq_finalize_oneshot(struct irq_desc *desc,
781 struct irqaction *action)
782{
783 if (!(desc->istate & IRQS_ONESHOT) ||
784 action->handler == irq_forced_secondary_handler)
785 return;
786again:
787 chip_bus_lock(desc);
788 raw_spin_lock_irq(&desc->lock);
789
790 /*
791 * Implausible though it may be we need to protect us against
792 * the following scenario:
793 *
794 * The thread is faster done than the hard interrupt handler
795 * on the other CPU. If we unmask the irq line then the
796 * interrupt can come in again and masks the line, leaves due
797 * to IRQS_INPROGRESS and the irq line is masked forever.
798 *
799 * This also serializes the state of shared oneshot handlers
800 * versus "desc->threads_onehsot |= action->thread_mask;" in
801 * irq_wake_thread(). See the comment there which explains the
802 * serialization.
803 */
804 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
805 raw_spin_unlock_irq(&desc->lock);
806 chip_bus_sync_unlock(desc);
807 cpu_relax();
808 goto again;
809 }
810
811 /*
812 * Now check again, whether the thread should run. Otherwise
813 * we would clear the threads_oneshot bit of this thread which
814 * was just set.
815 */
816 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
817 goto out_unlock;
818
819 desc->threads_oneshot &= ~action->thread_mask;
820
821 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
822 irqd_irq_masked(&desc->irq_data))
823 unmask_threaded_irq(desc);
824
825out_unlock:
826 raw_spin_unlock_irq(&desc->lock);
827 chip_bus_sync_unlock(desc);
828}
829
830#ifdef CONFIG_SMP
831/*
832 * Check whether we need to change the affinity of the interrupt thread.
833 */
834static void
835irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
836{
837 cpumask_var_t mask;
838 bool valid = true;
839
840 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
841 return;
842
843 /*
844 * In case we are out of memory we set IRQTF_AFFINITY again and
845 * try again next time
846 */
847 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
848 set_bit(IRQTF_AFFINITY, &action->thread_flags);
849 return;
850 }
851
852 raw_spin_lock_irq(&desc->lock);
853 /*
854 * This code is triggered unconditionally. Check the affinity
855 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
856 */
857 if (cpumask_available(desc->irq_common_data.affinity)) {
858 const struct cpumask *m;
859
860 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
861 cpumask_copy(mask, m);
862 } else {
863 valid = false;
864 }
865 raw_spin_unlock_irq(&desc->lock);
866
867 if (valid)
868 set_cpus_allowed_ptr(current, mask);
869 free_cpumask_var(mask);
870}
871#else
872static inline void
873irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
874#endif
875
876/*
877 * Interrupts which are not explicitely requested as threaded
878 * interrupts rely on the implicit bh/preempt disable of the hard irq
879 * context. So we need to disable bh here to avoid deadlocks and other
880 * side effects.
881 */
882static irqreturn_t
883irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
884{
885 irqreturn_t ret;
886
887 local_bh_disable();
888 ret = action->thread_fn(action->irq, action->dev_id);
889 irq_finalize_oneshot(desc, action);
890 local_bh_enable();
891 return ret;
892}
893
894/*
895 * Interrupts explicitly requested as threaded interrupts want to be
896 * preemtible - many of them need to sleep and wait for slow busses to
897 * complete.
898 */
899static irqreturn_t irq_thread_fn(struct irq_desc *desc,
900 struct irqaction *action)
901{
902 irqreturn_t ret;
903
904 ret = action->thread_fn(action->irq, action->dev_id);
905 irq_finalize_oneshot(desc, action);
906 return ret;
907}
908
909static void wake_threads_waitq(struct irq_desc *desc)
910{
911 if (atomic_dec_and_test(&desc->threads_active))
912 wake_up(&desc->wait_for_threads);
913}
914
915static void irq_thread_dtor(struct callback_head *unused)
916{
917 struct task_struct *tsk = current;
918 struct irq_desc *desc;
919 struct irqaction *action;
920
921 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
922 return;
923
924 action = kthread_data(tsk);
925
926 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
927 tsk->comm, tsk->pid, action->irq);
928
929
930 desc = irq_to_desc(action->irq);
931 /*
932 * If IRQTF_RUNTHREAD is set, we need to decrement
933 * desc->threads_active and wake possible waiters.
934 */
935 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
936 wake_threads_waitq(desc);
937
938 /* Prevent a stale desc->threads_oneshot */
939 irq_finalize_oneshot(desc, action);
940}
941
942static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
943{
944 struct irqaction *secondary = action->secondary;
945
946 if (WARN_ON_ONCE(!secondary))
947 return;
948
949 raw_spin_lock_irq(&desc->lock);
950 __irq_wake_thread(desc, secondary);
951 raw_spin_unlock_irq(&desc->lock);
952}
953
954/*
955 * Interrupt handler thread
956 */
957static int irq_thread(void *data)
958{
959 struct callback_head on_exit_work;
960 struct irqaction *action = data;
961 struct irq_desc *desc = irq_to_desc(action->irq);
962 irqreturn_t (*handler_fn)(struct irq_desc *desc,
963 struct irqaction *action);
964
965 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
966 &action->thread_flags))
967 handler_fn = irq_forced_thread_fn;
968 else
969 handler_fn = irq_thread_fn;
970
971 init_task_work(&on_exit_work, irq_thread_dtor);
972 task_work_add(current, &on_exit_work, false);
973
974 irq_thread_check_affinity(desc, action);
975
976 while (!irq_wait_for_interrupt(action)) {
977 irqreturn_t action_ret;
978
979 irq_thread_check_affinity(desc, action);
980
981 action_ret = handler_fn(desc, action);
982 if (action_ret == IRQ_HANDLED)
983 atomic_inc(&desc->threads_handled);
984 if (action_ret == IRQ_WAKE_THREAD)
985 irq_wake_secondary(desc, action);
986
987 wake_threads_waitq(desc);
988 }
989
990 /*
991 * This is the regular exit path. __free_irq() is stopping the
992 * thread via kthread_stop() after calling
993 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
994 * oneshot mask bit can be set. We cannot verify that as we
995 * cannot touch the oneshot mask at this point anymore as
996 * __setup_irq() might have given out currents thread_mask
997 * again.
998 */
999 task_work_cancel(current, irq_thread_dtor);
1000 return 0;
1001}
1002
1003/**
1004 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1005 * @irq: Interrupt line
1006 * @dev_id: Device identity for which the thread should be woken
1007 *
1008 */
1009void irq_wake_thread(unsigned int irq, void *dev_id)
1010{
1011 struct irq_desc *desc = irq_to_desc(irq);
1012 struct irqaction *action;
1013 unsigned long flags;
1014
1015 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1016 return;
1017
1018 raw_spin_lock_irqsave(&desc->lock, flags);
1019 for_each_action_of_desc(desc, action) {
1020 if (action->dev_id == dev_id) {
1021 if (action->thread)
1022 __irq_wake_thread(desc, action);
1023 break;
1024 }
1025 }
1026 raw_spin_unlock_irqrestore(&desc->lock, flags);
1027}
1028EXPORT_SYMBOL_GPL(irq_wake_thread);
1029
1030static int irq_setup_forced_threading(struct irqaction *new)
1031{
1032 if (!force_irqthreads)
1033 return 0;
1034 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1035 return 0;
1036
1037 new->flags |= IRQF_ONESHOT;
1038
1039 /*
1040 * Handle the case where we have a real primary handler and a
1041 * thread handler. We force thread them as well by creating a
1042 * secondary action.
1043 */
1044 if (new->handler != irq_default_primary_handler && new->thread_fn) {
1045 /* Allocate the secondary action */
1046 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1047 if (!new->secondary)
1048 return -ENOMEM;
1049 new->secondary->handler = irq_forced_secondary_handler;
1050 new->secondary->thread_fn = new->thread_fn;
1051 new->secondary->dev_id = new->dev_id;
1052 new->secondary->irq = new->irq;
1053 new->secondary->name = new->name;
1054 }
1055 /* Deal with the primary handler */
1056 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1057 new->thread_fn = new->handler;
1058 new->handler = irq_default_primary_handler;
1059 return 0;
1060}
1061
1062static int irq_request_resources(struct irq_desc *desc)
1063{
1064 struct irq_data *d = &desc->irq_data;
1065 struct irq_chip *c = d->chip;
1066
1067 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1068}
1069
1070static void irq_release_resources(struct irq_desc *desc)
1071{
1072 struct irq_data *d = &desc->irq_data;
1073 struct irq_chip *c = d->chip;
1074
1075 if (c->irq_release_resources)
1076 c->irq_release_resources(d);
1077}
1078
1079static int
1080setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1081{
1082 struct task_struct *t;
1083 struct sched_param param = {
1084 .sched_priority = MAX_USER_RT_PRIO/2,
1085 };
1086
1087 if (!secondary) {
1088 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1089 new->name);
1090 } else {
1091 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1092 new->name);
1093 param.sched_priority -= 1;
1094 }
1095
1096 if (IS_ERR(t))
1097 return PTR_ERR(t);
1098
1099 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1100
1101 /*
1102 * We keep the reference to the task struct even if
1103 * the thread dies to avoid that the interrupt code
1104 * references an already freed task_struct.
1105 */
1106 get_task_struct(t);
1107 new->thread = t;
1108 /*
1109 * Tell the thread to set its affinity. This is
1110 * important for shared interrupt handlers as we do
1111 * not invoke setup_affinity() for the secondary
1112 * handlers as everything is already set up. Even for
1113 * interrupts marked with IRQF_NO_BALANCE this is
1114 * correct as we want the thread to move to the cpu(s)
1115 * on which the requesting code placed the interrupt.
1116 */
1117 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1118 return 0;
1119}
1120
1121/*
1122 * Internal function to register an irqaction - typically used to
1123 * allocate special interrupts that are part of the architecture.
1124 *
1125 * Locking rules:
1126 *
1127 * desc->request_mutex Provides serialization against a concurrent free_irq()
1128 * chip_bus_lock Provides serialization for slow bus operations
1129 * desc->lock Provides serialization against hard interrupts
1130 *
1131 * chip_bus_lock and desc->lock are sufficient for all other management and
1132 * interrupt related functions. desc->request_mutex solely serializes
1133 * request/free_irq().
1134 */
1135static int
1136__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1137{
1138 struct irqaction *old, **old_ptr;
1139 unsigned long flags, thread_mask = 0;
1140 int ret, nested, shared = 0;
1141
1142 if (!desc)
1143 return -EINVAL;
1144
1145 if (desc->irq_data.chip == &no_irq_chip)
1146 return -ENOSYS;
1147 if (!try_module_get(desc->owner))
1148 return -ENODEV;
1149
1150 new->irq = irq;
1151
1152 /*
1153 * If the trigger type is not specified by the caller,
1154 * then use the default for this interrupt.
1155 */
1156 if (!(new->flags & IRQF_TRIGGER_MASK))
1157 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1158
1159 /*
1160 * Check whether the interrupt nests into another interrupt
1161 * thread.
1162 */
1163 nested = irq_settings_is_nested_thread(desc);
1164 if (nested) {
1165 if (!new->thread_fn) {
1166 ret = -EINVAL;
1167 goto out_mput;
1168 }
1169 /*
1170 * Replace the primary handler which was provided from
1171 * the driver for non nested interrupt handling by the
1172 * dummy function which warns when called.
1173 */
1174 new->handler = irq_nested_primary_handler;
1175 } else {
1176 if (irq_settings_can_thread(desc)) {
1177 ret = irq_setup_forced_threading(new);
1178 if (ret)
1179 goto out_mput;
1180 }
1181 }
1182
1183 /*
1184 * Create a handler thread when a thread function is supplied
1185 * and the interrupt does not nest into another interrupt
1186 * thread.
1187 */
1188 if (new->thread_fn && !nested) {
1189 ret = setup_irq_thread(new, irq, false);
1190 if (ret)
1191 goto out_mput;
1192 if (new->secondary) {
1193 ret = setup_irq_thread(new->secondary, irq, true);
1194 if (ret)
1195 goto out_thread;
1196 }
1197 }
1198
1199 /*
1200 * Drivers are often written to work w/o knowledge about the
1201 * underlying irq chip implementation, so a request for a
1202 * threaded irq without a primary hard irq context handler
1203 * requires the ONESHOT flag to be set. Some irq chips like
1204 * MSI based interrupts are per se one shot safe. Check the
1205 * chip flags, so we can avoid the unmask dance at the end of
1206 * the threaded handler for those.
1207 */
1208 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1209 new->flags &= ~IRQF_ONESHOT;
1210
1211 /*
1212 * Protects against a concurrent __free_irq() call which might wait
1213 * for synchronize_irq() to complete without holding the optional
1214 * chip bus lock and desc->lock.
1215 */
1216 mutex_lock(&desc->request_mutex);
1217
1218 /*
1219 * Acquire bus lock as the irq_request_resources() callback below
1220 * might rely on the serialization or the magic power management
1221 * functions which are abusing the irq_bus_lock() callback,
1222 */
1223 chip_bus_lock(desc);
1224
1225 /* First installed action requests resources. */
1226 if (!desc->action) {
1227 ret = irq_request_resources(desc);
1228 if (ret) {
1229 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1230 new->name, irq, desc->irq_data.chip->name);
1231 goto out_bus_unlock;
1232 }
1233 }
1234
1235 /*
1236 * The following block of code has to be executed atomically
1237 * protected against a concurrent interrupt and any of the other
1238 * management calls which are not serialized via
1239 * desc->request_mutex or the optional bus lock.
1240 */
1241 raw_spin_lock_irqsave(&desc->lock, flags);
1242 old_ptr = &desc->action;
1243 old = *old_ptr;
1244 if (old) {
1245 /*
1246 * Can't share interrupts unless both agree to and are
1247 * the same type (level, edge, polarity). So both flag
1248 * fields must have IRQF_SHARED set and the bits which
1249 * set the trigger type must match. Also all must
1250 * agree on ONESHOT.
1251 */
1252 unsigned int oldtype;
1253
1254 /*
1255 * If nobody did set the configuration before, inherit
1256 * the one provided by the requester.
1257 */
1258 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1259 oldtype = irqd_get_trigger_type(&desc->irq_data);
1260 } else {
1261 oldtype = new->flags & IRQF_TRIGGER_MASK;
1262 irqd_set_trigger_type(&desc->irq_data, oldtype);
1263 }
1264
1265 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1266 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1267 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1268 goto mismatch;
1269
1270 /* All handlers must agree on per-cpuness */
1271 if ((old->flags & IRQF_PERCPU) !=
1272 (new->flags & IRQF_PERCPU))
1273 goto mismatch;
1274
1275 /* add new interrupt at end of irq queue */
1276 do {
1277 /*
1278 * Or all existing action->thread_mask bits,
1279 * so we can find the next zero bit for this
1280 * new action.
1281 */
1282 thread_mask |= old->thread_mask;
1283 old_ptr = &old->next;
1284 old = *old_ptr;
1285 } while (old);
1286 shared = 1;
1287 }
1288
1289 /*
1290 * Setup the thread mask for this irqaction for ONESHOT. For
1291 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1292 * conditional in irq_wake_thread().
1293 */
1294 if (new->flags & IRQF_ONESHOT) {
1295 /*
1296 * Unlikely to have 32 resp 64 irqs sharing one line,
1297 * but who knows.
1298 */
1299 if (thread_mask == ~0UL) {
1300 ret = -EBUSY;
1301 goto out_unlock;
1302 }
1303 /*
1304 * The thread_mask for the action is or'ed to
1305 * desc->thread_active to indicate that the
1306 * IRQF_ONESHOT thread handler has been woken, but not
1307 * yet finished. The bit is cleared when a thread
1308 * completes. When all threads of a shared interrupt
1309 * line have completed desc->threads_active becomes
1310 * zero and the interrupt line is unmasked. See
1311 * handle.c:irq_wake_thread() for further information.
1312 *
1313 * If no thread is woken by primary (hard irq context)
1314 * interrupt handlers, then desc->threads_active is
1315 * also checked for zero to unmask the irq line in the
1316 * affected hard irq flow handlers
1317 * (handle_[fasteoi|level]_irq).
1318 *
1319 * The new action gets the first zero bit of
1320 * thread_mask assigned. See the loop above which or's
1321 * all existing action->thread_mask bits.
1322 */
1323 new->thread_mask = 1UL << ffz(thread_mask);
1324
1325 } else if (new->handler == irq_default_primary_handler &&
1326 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1327 /*
1328 * The interrupt was requested with handler = NULL, so
1329 * we use the default primary handler for it. But it
1330 * does not have the oneshot flag set. In combination
1331 * with level interrupts this is deadly, because the
1332 * default primary handler just wakes the thread, then
1333 * the irq lines is reenabled, but the device still
1334 * has the level irq asserted. Rinse and repeat....
1335 *
1336 * While this works for edge type interrupts, we play
1337 * it safe and reject unconditionally because we can't
1338 * say for sure which type this interrupt really
1339 * has. The type flags are unreliable as the
1340 * underlying chip implementation can override them.
1341 */
1342 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1343 irq);
1344 ret = -EINVAL;
1345 goto out_unlock;
1346 }
1347
1348 if (!shared) {
1349 init_waitqueue_head(&desc->wait_for_threads);
1350
1351 /* Setup the type (level, edge polarity) if configured: */
1352 if (new->flags & IRQF_TRIGGER_MASK) {
1353 ret = __irq_set_trigger(desc,
1354 new->flags & IRQF_TRIGGER_MASK);
1355
1356 if (ret)
1357 goto out_unlock;
1358 }
1359
1360 /*
1361 * Activate the interrupt. That activation must happen
1362 * independently of IRQ_NOAUTOEN. request_irq() can fail
1363 * and the callers are supposed to handle
1364 * that. enable_irq() of an interrupt requested with
1365 * IRQ_NOAUTOEN is not supposed to fail. The activation
1366 * keeps it in shutdown mode, it merily associates
1367 * resources if necessary and if that's not possible it
1368 * fails. Interrupts which are in managed shutdown mode
1369 * will simply ignore that activation request.
1370 */
1371 ret = irq_activate(desc);
1372 if (ret)
1373 goto out_unlock;
1374
1375 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1376 IRQS_ONESHOT | IRQS_WAITING);
1377 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1378
1379 if (new->flags & IRQF_PERCPU) {
1380 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1381 irq_settings_set_per_cpu(desc);
1382 }
1383
1384 if (new->flags & IRQF_ONESHOT)
1385 desc->istate |= IRQS_ONESHOT;
1386
1387 /* Exclude IRQ from balancing if requested */
1388 if (new->flags & IRQF_NOBALANCING) {
1389 irq_settings_set_no_balancing(desc);
1390 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1391 }
1392
1393 if (irq_settings_can_autoenable(desc)) {
1394 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1395 } else {
1396 /*
1397 * Shared interrupts do not go well with disabling
1398 * auto enable. The sharing interrupt might request
1399 * it while it's still disabled and then wait for
1400 * interrupts forever.
1401 */
1402 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1403 /* Undo nested disables: */
1404 desc->depth = 1;
1405 }
1406
1407 } else if (new->flags & IRQF_TRIGGER_MASK) {
1408 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1409 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1410
1411 if (nmsk != omsk)
1412 /* hope the handler works with current trigger mode */
1413 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1414 irq, omsk, nmsk);
1415 }
1416
1417 *old_ptr = new;
1418
1419 irq_pm_install_action(desc, new);
1420
1421 /* Reset broken irq detection when installing new handler */
1422 desc->irq_count = 0;
1423 desc->irqs_unhandled = 0;
1424
1425 /*
1426 * Check whether we disabled the irq via the spurious handler
1427 * before. Reenable it and give it another chance.
1428 */
1429 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1430 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1431 __enable_irq(desc);
1432 }
1433
1434 raw_spin_unlock_irqrestore(&desc->lock, flags);
1435 chip_bus_sync_unlock(desc);
1436 mutex_unlock(&desc->request_mutex);
1437
1438 irq_setup_timings(desc, new);
1439
1440 /*
1441 * Strictly no need to wake it up, but hung_task complains
1442 * when no hard interrupt wakes the thread up.
1443 */
1444 if (new->thread)
1445 wake_up_process(new->thread);
1446 if (new->secondary)
1447 wake_up_process(new->secondary->thread);
1448
1449 register_irq_proc(irq, desc);
1450 new->dir = NULL;
1451 register_handler_proc(irq, new);
1452 return 0;
1453
1454mismatch:
1455 if (!(new->flags & IRQF_PROBE_SHARED)) {
1456 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1457 irq, new->flags, new->name, old->flags, old->name);
1458#ifdef CONFIG_DEBUG_SHIRQ
1459 dump_stack();
1460#endif
1461 }
1462 ret = -EBUSY;
1463
1464out_unlock:
1465 raw_spin_unlock_irqrestore(&desc->lock, flags);
1466
1467 if (!desc->action)
1468 irq_release_resources(desc);
1469out_bus_unlock:
1470 chip_bus_sync_unlock(desc);
1471 mutex_unlock(&desc->request_mutex);
1472
1473out_thread:
1474 if (new->thread) {
1475 struct task_struct *t = new->thread;
1476
1477 new->thread = NULL;
1478 kthread_stop(t);
1479 put_task_struct(t);
1480 }
1481 if (new->secondary && new->secondary->thread) {
1482 struct task_struct *t = new->secondary->thread;
1483
1484 new->secondary->thread = NULL;
1485 kthread_stop(t);
1486 put_task_struct(t);
1487 }
1488out_mput:
1489 module_put(desc->owner);
1490 return ret;
1491}
1492
1493/**
1494 * setup_irq - setup an interrupt
1495 * @irq: Interrupt line to setup
1496 * @act: irqaction for the interrupt
1497 *
1498 * Used to statically setup interrupts in the early boot process.
1499 */
1500int setup_irq(unsigned int irq, struct irqaction *act)
1501{
1502 int retval;
1503 struct irq_desc *desc = irq_to_desc(irq);
1504
1505 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1506 return -EINVAL;
1507
1508 retval = irq_chip_pm_get(&desc->irq_data);
1509 if (retval < 0)
1510 return retval;
1511
1512 retval = __setup_irq(irq, desc, act);
1513
1514 if (retval)
1515 irq_chip_pm_put(&desc->irq_data);
1516
1517 return retval;
1518}
1519EXPORT_SYMBOL_GPL(setup_irq);
1520
1521/*
1522 * Internal function to unregister an irqaction - used to free
1523 * regular and special interrupts that are part of the architecture.
1524 */
1525static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1526{
1527 unsigned irq = desc->irq_data.irq;
1528 struct irqaction *action, **action_ptr;
1529 unsigned long flags;
1530
1531 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1532
1533 if (!desc)
1534 return NULL;
1535
1536 mutex_lock(&desc->request_mutex);
1537 chip_bus_lock(desc);
1538 raw_spin_lock_irqsave(&desc->lock, flags);
1539
1540 /*
1541 * There can be multiple actions per IRQ descriptor, find the right
1542 * one based on the dev_id:
1543 */
1544 action_ptr = &desc->action;
1545 for (;;) {
1546 action = *action_ptr;
1547
1548 if (!action) {
1549 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1550 raw_spin_unlock_irqrestore(&desc->lock, flags);
1551 chip_bus_sync_unlock(desc);
1552 mutex_unlock(&desc->request_mutex);
1553 return NULL;
1554 }
1555
1556 if (action->dev_id == dev_id)
1557 break;
1558 action_ptr = &action->next;
1559 }
1560
1561 /* Found it - now remove it from the list of entries: */
1562 *action_ptr = action->next;
1563
1564 irq_pm_remove_action(desc, action);
1565
1566 /* If this was the last handler, shut down the IRQ line: */
1567 if (!desc->action) {
1568 irq_settings_clr_disable_unlazy(desc);
1569 irq_shutdown(desc);
1570 }
1571
1572#ifdef CONFIG_SMP
1573 /* make sure affinity_hint is cleaned up */
1574 if (WARN_ON_ONCE(desc->affinity_hint))
1575 desc->affinity_hint = NULL;
1576#endif
1577
1578 raw_spin_unlock_irqrestore(&desc->lock, flags);
1579 /*
1580 * Drop bus_lock here so the changes which were done in the chip
1581 * callbacks above are synced out to the irq chips which hang
1582 * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1583 *
1584 * Aside of that the bus_lock can also be taken from the threaded
1585 * handler in irq_finalize_oneshot() which results in a deadlock
1586 * because synchronize_irq() would wait forever for the thread to
1587 * complete, which is blocked on the bus lock.
1588 *
1589 * The still held desc->request_mutex() protects against a
1590 * concurrent request_irq() of this irq so the release of resources
1591 * and timing data is properly serialized.
1592 */
1593 chip_bus_sync_unlock(desc);
1594
1595 unregister_handler_proc(irq, action);
1596
1597 /* Make sure it's not being used on another CPU: */
1598 synchronize_irq(irq);
1599
1600#ifdef CONFIG_DEBUG_SHIRQ
1601 /*
1602 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1603 * event to happen even now it's being freed, so let's make sure that
1604 * is so by doing an extra call to the handler ....
1605 *
1606 * ( We do this after actually deregistering it, to make sure that a
1607 * 'real' IRQ doesn't run in * parallel with our fake. )
1608 */
1609 if (action->flags & IRQF_SHARED) {
1610 local_irq_save(flags);
1611 action->handler(irq, dev_id);
1612 local_irq_restore(flags);
1613 }
1614#endif
1615
1616 if (action->thread) {
1617 kthread_stop(action->thread);
1618 put_task_struct(action->thread);
1619 if (action->secondary && action->secondary->thread) {
1620 kthread_stop(action->secondary->thread);
1621 put_task_struct(action->secondary->thread);
1622 }
1623 }
1624
1625 /* Last action releases resources */
1626 if (!desc->action) {
1627 /*
1628 * Reaquire bus lock as irq_release_resources() might
1629 * require it to deallocate resources over the slow bus.
1630 */
1631 chip_bus_lock(desc);
1632 irq_release_resources(desc);
1633 chip_bus_sync_unlock(desc);
1634 irq_remove_timings(desc);
1635 }
1636
1637 mutex_unlock(&desc->request_mutex);
1638
1639 irq_chip_pm_put(&desc->irq_data);
1640 module_put(desc->owner);
1641 kfree(action->secondary);
1642 return action;
1643}
1644
1645/**
1646 * remove_irq - free an interrupt
1647 * @irq: Interrupt line to free
1648 * @act: irqaction for the interrupt
1649 *
1650 * Used to remove interrupts statically setup by the early boot process.
1651 */
1652void remove_irq(unsigned int irq, struct irqaction *act)
1653{
1654 struct irq_desc *desc = irq_to_desc(irq);
1655
1656 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1657 __free_irq(desc, act->dev_id);
1658}
1659EXPORT_SYMBOL_GPL(remove_irq);
1660
1661/**
1662 * free_irq - free an interrupt allocated with request_irq
1663 * @irq: Interrupt line to free
1664 * @dev_id: Device identity to free
1665 *
1666 * Remove an interrupt handler. The handler is removed and if the
1667 * interrupt line is no longer in use by any driver it is disabled.
1668 * On a shared IRQ the caller must ensure the interrupt is disabled
1669 * on the card it drives before calling this function. The function
1670 * does not return until any executing interrupts for this IRQ
1671 * have completed.
1672 *
1673 * This function must not be called from interrupt context.
1674 *
1675 * Returns the devname argument passed to request_irq.
1676 */
1677const void *free_irq(unsigned int irq, void *dev_id)
1678{
1679 struct irq_desc *desc = irq_to_desc(irq);
1680 struct irqaction *action;
1681 const char *devname;
1682
1683 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1684 return NULL;
1685
1686#ifdef CONFIG_SMP
1687 if (WARN_ON(desc->affinity_notify))
1688 desc->affinity_notify = NULL;
1689#endif
1690
1691 action = __free_irq(desc, dev_id);
1692
1693 if (!action)
1694 return NULL;
1695
1696 devname = action->name;
1697 kfree(action);
1698 return devname;
1699}
1700EXPORT_SYMBOL(free_irq);
1701
1702/**
1703 * request_threaded_irq - allocate an interrupt line
1704 * @irq: Interrupt line to allocate
1705 * @handler: Function to be called when the IRQ occurs.
1706 * Primary handler for threaded interrupts
1707 * If NULL and thread_fn != NULL the default
1708 * primary handler is installed
1709 * @thread_fn: Function called from the irq handler thread
1710 * If NULL, no irq thread is created
1711 * @irqflags: Interrupt type flags
1712 * @devname: An ascii name for the claiming device
1713 * @dev_id: A cookie passed back to the handler function
1714 *
1715 * This call allocates interrupt resources and enables the
1716 * interrupt line and IRQ handling. From the point this
1717 * call is made your handler function may be invoked. Since
1718 * your handler function must clear any interrupt the board
1719 * raises, you must take care both to initialise your hardware
1720 * and to set up the interrupt handler in the right order.
1721 *
1722 * If you want to set up a threaded irq handler for your device
1723 * then you need to supply @handler and @thread_fn. @handler is
1724 * still called in hard interrupt context and has to check
1725 * whether the interrupt originates from the device. If yes it
1726 * needs to disable the interrupt on the device and return
1727 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1728 * @thread_fn. This split handler design is necessary to support
1729 * shared interrupts.
1730 *
1731 * Dev_id must be globally unique. Normally the address of the
1732 * device data structure is used as the cookie. Since the handler
1733 * receives this value it makes sense to use it.
1734 *
1735 * If your interrupt is shared you must pass a non NULL dev_id
1736 * as this is required when freeing the interrupt.
1737 *
1738 * Flags:
1739 *
1740 * IRQF_SHARED Interrupt is shared
1741 * IRQF_TRIGGER_* Specify active edge(s) or level
1742 *
1743 */
1744int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1745 irq_handler_t thread_fn, unsigned long irqflags,
1746 const char *devname, void *dev_id)
1747{
1748 struct irqaction *action;
1749 struct irq_desc *desc;
1750 int retval;
1751
1752 if (irq == IRQ_NOTCONNECTED)
1753 return -ENOTCONN;
1754
1755 /*
1756 * Sanity-check: shared interrupts must pass in a real dev-ID,
1757 * otherwise we'll have trouble later trying to figure out
1758 * which interrupt is which (messes up the interrupt freeing
1759 * logic etc).
1760 *
1761 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1762 * it cannot be set along with IRQF_NO_SUSPEND.
1763 */
1764 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1765 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1766 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1767 return -EINVAL;
1768
1769 desc = irq_to_desc(irq);
1770 if (!desc)
1771 return -EINVAL;
1772
1773 if (!irq_settings_can_request(desc) ||
1774 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1775 return -EINVAL;
1776
1777 if (!handler) {
1778 if (!thread_fn)
1779 return -EINVAL;
1780 handler = irq_default_primary_handler;
1781 }
1782
1783 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1784 if (!action)
1785 return -ENOMEM;
1786
1787 action->handler = handler;
1788 action->thread_fn = thread_fn;
1789 action->flags = irqflags;
1790 action->name = devname;
1791 action->dev_id = dev_id;
1792
1793 retval = irq_chip_pm_get(&desc->irq_data);
1794 if (retval < 0) {
1795 kfree(action);
1796 return retval;
1797 }
1798
1799 retval = __setup_irq(irq, desc, action);
1800
1801 if (retval) {
1802 irq_chip_pm_put(&desc->irq_data);
1803 kfree(action->secondary);
1804 kfree(action);
1805 }
1806
1807#ifdef CONFIG_DEBUG_SHIRQ_FIXME
1808 if (!retval && (irqflags & IRQF_SHARED)) {
1809 /*
1810 * It's a shared IRQ -- the driver ought to be prepared for it
1811 * to happen immediately, so let's make sure....
1812 * We disable the irq to make sure that a 'real' IRQ doesn't
1813 * run in parallel with our fake.
1814 */
1815 unsigned long flags;
1816
1817 disable_irq(irq);
1818 local_irq_save(flags);
1819
1820 handler(irq, dev_id);
1821
1822 local_irq_restore(flags);
1823 enable_irq(irq);
1824 }
1825#endif
1826 return retval;
1827}
1828EXPORT_SYMBOL(request_threaded_irq);
1829
1830/**
1831 * request_any_context_irq - allocate an interrupt line
1832 * @irq: Interrupt line to allocate
1833 * @handler: Function to be called when the IRQ occurs.
1834 * Threaded handler for threaded interrupts.
1835 * @flags: Interrupt type flags
1836 * @name: An ascii name for the claiming device
1837 * @dev_id: A cookie passed back to the handler function
1838 *
1839 * This call allocates interrupt resources and enables the
1840 * interrupt line and IRQ handling. It selects either a
1841 * hardirq or threaded handling method depending on the
1842 * context.
1843 *
1844 * On failure, it returns a negative value. On success,
1845 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1846 */
1847int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1848 unsigned long flags, const char *name, void *dev_id)
1849{
1850 struct irq_desc *desc;
1851 int ret;
1852
1853 if (irq == IRQ_NOTCONNECTED)
1854 return -ENOTCONN;
1855
1856 desc = irq_to_desc(irq);
1857 if (!desc)
1858 return -EINVAL;
1859
1860 if (irq_settings_is_nested_thread(desc)) {
1861 ret = request_threaded_irq(irq, NULL, handler,
1862 flags, name, dev_id);
1863 return !ret ? IRQC_IS_NESTED : ret;
1864 }
1865
1866 ret = request_irq(irq, handler, flags, name, dev_id);
1867 return !ret ? IRQC_IS_HARDIRQ : ret;
1868}
1869EXPORT_SYMBOL_GPL(request_any_context_irq);
1870
1871void enable_percpu_irq(unsigned int irq, unsigned int type)
1872{
1873 unsigned int cpu = smp_processor_id();
1874 unsigned long flags;
1875 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1876
1877 if (!desc)
1878 return;
1879
1880 /*
1881 * If the trigger type is not specified by the caller, then
1882 * use the default for this interrupt.
1883 */
1884 type &= IRQ_TYPE_SENSE_MASK;
1885 if (type == IRQ_TYPE_NONE)
1886 type = irqd_get_trigger_type(&desc->irq_data);
1887
1888 if (type != IRQ_TYPE_NONE) {
1889 int ret;
1890
1891 ret = __irq_set_trigger(desc, type);
1892
1893 if (ret) {
1894 WARN(1, "failed to set type for IRQ%d\n", irq);
1895 goto out;
1896 }
1897 }
1898
1899 irq_percpu_enable(desc, cpu);
1900out:
1901 irq_put_desc_unlock(desc, flags);
1902}
1903EXPORT_SYMBOL_GPL(enable_percpu_irq);
1904
1905/**
1906 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1907 * @irq: Linux irq number to check for
1908 *
1909 * Must be called from a non migratable context. Returns the enable
1910 * state of a per cpu interrupt on the current cpu.
1911 */
1912bool irq_percpu_is_enabled(unsigned int irq)
1913{
1914 unsigned int cpu = smp_processor_id();
1915 struct irq_desc *desc;
1916 unsigned long flags;
1917 bool is_enabled;
1918
1919 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1920 if (!desc)
1921 return false;
1922
1923 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1924 irq_put_desc_unlock(desc, flags);
1925
1926 return is_enabled;
1927}
1928EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1929
1930void disable_percpu_irq(unsigned int irq)
1931{
1932 unsigned int cpu = smp_processor_id();
1933 unsigned long flags;
1934 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1935
1936 if (!desc)
1937 return;
1938
1939 irq_percpu_disable(desc, cpu);
1940 irq_put_desc_unlock(desc, flags);
1941}
1942EXPORT_SYMBOL_GPL(disable_percpu_irq);
1943
1944/*
1945 * Internal function to unregister a percpu irqaction.
1946 */
1947static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1948{
1949 struct irq_desc *desc = irq_to_desc(irq);
1950 struct irqaction *action;
1951 unsigned long flags;
1952
1953 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1954
1955 if (!desc)
1956 return NULL;
1957
1958 raw_spin_lock_irqsave(&desc->lock, flags);
1959
1960 action = desc->action;
1961 if (!action || action->percpu_dev_id != dev_id) {
1962 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1963 goto bad;
1964 }
1965
1966 if (!cpumask_empty(desc->percpu_enabled)) {
1967 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1968 irq, cpumask_first(desc->percpu_enabled));
1969 goto bad;
1970 }
1971
1972 /* Found it - now remove it from the list of entries: */
1973 desc->action = NULL;
1974
1975 raw_spin_unlock_irqrestore(&desc->lock, flags);
1976
1977 unregister_handler_proc(irq, action);
1978
1979 irq_chip_pm_put(&desc->irq_data);
1980 module_put(desc->owner);
1981 return action;
1982
1983bad:
1984 raw_spin_unlock_irqrestore(&desc->lock, flags);
1985 return NULL;
1986}
1987
1988/**
1989 * remove_percpu_irq - free a per-cpu interrupt
1990 * @irq: Interrupt line to free
1991 * @act: irqaction for the interrupt
1992 *
1993 * Used to remove interrupts statically setup by the early boot process.
1994 */
1995void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1996{
1997 struct irq_desc *desc = irq_to_desc(irq);
1998
1999 if (desc && irq_settings_is_per_cpu_devid(desc))
2000 __free_percpu_irq(irq, act->percpu_dev_id);
2001}
2002
2003/**
2004 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2005 * @irq: Interrupt line to free
2006 * @dev_id: Device identity to free
2007 *
2008 * Remove a percpu interrupt handler. The handler is removed, but
2009 * the interrupt line is not disabled. This must be done on each
2010 * CPU before calling this function. The function does not return
2011 * until any executing interrupts for this IRQ have completed.
2012 *
2013 * This function must not be called from interrupt context.
2014 */
2015void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2016{
2017 struct irq_desc *desc = irq_to_desc(irq);
2018
2019 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2020 return;
2021
2022 chip_bus_lock(desc);
2023 kfree(__free_percpu_irq(irq, dev_id));
2024 chip_bus_sync_unlock(desc);
2025}
2026EXPORT_SYMBOL_GPL(free_percpu_irq);
2027
2028/**
2029 * setup_percpu_irq - setup a per-cpu interrupt
2030 * @irq: Interrupt line to setup
2031 * @act: irqaction for the interrupt
2032 *
2033 * Used to statically setup per-cpu interrupts in the early boot process.
2034 */
2035int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2036{
2037 struct irq_desc *desc = irq_to_desc(irq);
2038 int retval;
2039
2040 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2041 return -EINVAL;
2042
2043 retval = irq_chip_pm_get(&desc->irq_data);
2044 if (retval < 0)
2045 return retval;
2046
2047 retval = __setup_irq(irq, desc, act);
2048
2049 if (retval)
2050 irq_chip_pm_put(&desc->irq_data);
2051
2052 return retval;
2053}
2054
2055/**
2056 * __request_percpu_irq - allocate a percpu interrupt line
2057 * @irq: Interrupt line to allocate
2058 * @handler: Function to be called when the IRQ occurs.
2059 * @flags: Interrupt type flags (IRQF_TIMER only)
2060 * @devname: An ascii name for the claiming device
2061 * @dev_id: A percpu cookie passed back to the handler function
2062 *
2063 * This call allocates interrupt resources and enables the
2064 * interrupt on the local CPU. If the interrupt is supposed to be
2065 * enabled on other CPUs, it has to be done on each CPU using
2066 * enable_percpu_irq().
2067 *
2068 * Dev_id must be globally unique. It is a per-cpu variable, and
2069 * the handler gets called with the interrupted CPU's instance of
2070 * that variable.
2071 */
2072int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2073 unsigned long flags, const char *devname,
2074 void __percpu *dev_id)
2075{
2076 struct irqaction *action;
2077 struct irq_desc *desc;
2078 int retval;
2079
2080 if (!dev_id)
2081 return -EINVAL;
2082
2083 desc = irq_to_desc(irq);
2084 if (!desc || !irq_settings_can_request(desc) ||
2085 !irq_settings_is_per_cpu_devid(desc))
2086 return -EINVAL;
2087
2088 if (flags && flags != IRQF_TIMER)
2089 return -EINVAL;
2090
2091 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2092 if (!action)
2093 return -ENOMEM;
2094
2095 action->handler = handler;
2096 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2097 action->name = devname;
2098 action->percpu_dev_id = dev_id;
2099
2100 retval = irq_chip_pm_get(&desc->irq_data);
2101 if (retval < 0) {
2102 kfree(action);
2103 return retval;
2104 }
2105
2106 retval = __setup_irq(irq, desc, action);
2107
2108 if (retval) {
2109 irq_chip_pm_put(&desc->irq_data);
2110 kfree(action);
2111 }
2112
2113 return retval;
2114}
2115EXPORT_SYMBOL_GPL(__request_percpu_irq);
2116
2117/**
2118 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2119 * @irq: Interrupt line that is forwarded to a VM
2120 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2121 * @state: a pointer to a boolean where the state is to be storeed
2122 *
2123 * This call snapshots the internal irqchip state of an
2124 * interrupt, returning into @state the bit corresponding to
2125 * stage @which
2126 *
2127 * This function should be called with preemption disabled if the
2128 * interrupt controller has per-cpu registers.
2129 */
2130int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2131 bool *state)
2132{
2133 struct irq_desc *desc;
2134 struct irq_data *data;
2135 struct irq_chip *chip;
2136 unsigned long flags;
2137 int err = -EINVAL;
2138
2139 desc = irq_get_desc_buslock(irq, &flags, 0);
2140 if (!desc)
2141 return err;
2142
2143 data = irq_desc_get_irq_data(desc);
2144
2145 do {
2146 chip = irq_data_get_irq_chip(data);
2147 if (chip->irq_get_irqchip_state)
2148 break;
2149#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2150 data = data->parent_data;
2151#else
2152 data = NULL;
2153#endif
2154 } while (data);
2155
2156 if (data)
2157 err = chip->irq_get_irqchip_state(data, which, state);
2158
2159 irq_put_desc_busunlock(desc, flags);
2160 return err;
2161}
2162EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2163
2164/**
2165 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2166 * @irq: Interrupt line that is forwarded to a VM
2167 * @which: State to be restored (one of IRQCHIP_STATE_*)
2168 * @val: Value corresponding to @which
2169 *
2170 * This call sets the internal irqchip state of an interrupt,
2171 * depending on the value of @which.
2172 *
2173 * This function should be called with preemption disabled if the
2174 * interrupt controller has per-cpu registers.
2175 */
2176int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2177 bool val)
2178{
2179 struct irq_desc *desc;
2180 struct irq_data *data;
2181 struct irq_chip *chip;
2182 unsigned long flags;
2183 int err = -EINVAL;
2184
2185 desc = irq_get_desc_buslock(irq, &flags, 0);
2186 if (!desc)
2187 return err;
2188
2189 data = irq_desc_get_irq_data(desc);
2190
2191 do {
2192 chip = irq_data_get_irq_chip(data);
2193 if (chip->irq_set_irqchip_state)
2194 break;
2195#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2196 data = data->parent_data;
2197#else
2198 data = NULL;
2199#endif
2200 } while (data);
2201
2202 if (data)
2203 err = chip->irq_set_irqchip_state(data, which, val);
2204
2205 irq_put_desc_busunlock(desc, flags);
2206 return err;
2207}
2208EXPORT_SYMBOL_GPL(irq_set_irqchip_state);