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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/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
29
30static int __init setup_forced_irqthreads(char *arg)
31{
32 static_branch_enable(&force_irqthreads_key);
33 return 0;
34}
35early_param("threadirqs", setup_forced_irqthreads);
36#endif
37
38static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
39{
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
41 bool inprogress;
42
43 do {
44 unsigned long flags;
45
46 /*
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
49 */
50 while (irqd_irq_inprogress(&desc->irq_data))
51 cpu_relax();
52
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
56
57 /*
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
61 */
62 if (!inprogress && sync_chip) {
63 /*
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
66 */
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
68 &inprogress);
69 }
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
71
72 /* Oops, that failed? */
73 } while (inprogress);
74}
75
76/**
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
79 *
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
84 * into account.
85 *
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
88 *
89 * Returns: false if a threaded handler is active.
90 *
91 * This function may be called - with care - from IRQ context.
92 *
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
96 * is the current CPU.
97 */
98bool synchronize_hardirq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
105 }
106
107 return true;
108}
109EXPORT_SYMBOL(synchronize_hardirq);
110
111static void __synchronize_irq(struct irq_desc *desc)
112{
113 __synchronize_hardirq(desc, true);
114 /*
115 * We made sure that no hardirq handler is running. Now verify that no
116 * threaded handlers are active.
117 */
118 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
119}
120
121/**
122 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
123 * @irq: interrupt number to wait for
124 *
125 * This function waits for any pending IRQ handlers for this interrupt
126 * to complete before returning. If you use this function while
127 * holding a resource the IRQ handler may need you will deadlock.
128 *
129 * Can only be called from preemptible code as it might sleep when
130 * an interrupt thread is associated to @irq.
131 *
132 * It optionally makes sure (when the irq chip supports that method)
133 * that the interrupt is not pending in any CPU and waiting for
134 * service.
135 */
136void synchronize_irq(unsigned int irq)
137{
138 struct irq_desc *desc = irq_to_desc(irq);
139
140 if (desc)
141 __synchronize_irq(desc);
142}
143EXPORT_SYMBOL(synchronize_irq);
144
145#ifdef CONFIG_SMP
146cpumask_var_t irq_default_affinity;
147
148static bool __irq_can_set_affinity(struct irq_desc *desc)
149{
150 if (!desc || !irqd_can_balance(&desc->irq_data) ||
151 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
152 return false;
153 return true;
154}
155
156/**
157 * irq_can_set_affinity - Check if the affinity of a given irq can be set
158 * @irq: Interrupt to check
159 *
160 */
161int irq_can_set_affinity(unsigned int irq)
162{
163 return __irq_can_set_affinity(irq_to_desc(irq));
164}
165
166/**
167 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
168 * @irq: Interrupt to check
169 *
170 * Like irq_can_set_affinity() above, but additionally checks for the
171 * AFFINITY_MANAGED flag.
172 */
173bool irq_can_set_affinity_usr(unsigned int irq)
174{
175 struct irq_desc *desc = irq_to_desc(irq);
176
177 return __irq_can_set_affinity(desc) &&
178 !irqd_affinity_is_managed(&desc->irq_data);
179}
180
181/**
182 * irq_set_thread_affinity - Notify irq threads to adjust affinity
183 * @desc: irq descriptor which has affinity changed
184 *
185 * We just set IRQTF_AFFINITY and delegate the affinity setting
186 * to the interrupt thread itself. We can not call
187 * set_cpus_allowed_ptr() here as we hold desc->lock and this
188 * code can be called from hard interrupt context.
189 */
190void irq_set_thread_affinity(struct irq_desc *desc)
191{
192 struct irqaction *action;
193
194 for_each_action_of_desc(desc, action) {
195 if (action->thread) {
196 set_bit(IRQTF_AFFINITY, &action->thread_flags);
197 wake_up_process(action->thread);
198 }
199 if (action->secondary && action->secondary->thread) {
200 set_bit(IRQTF_AFFINITY, &action->secondary->thread_flags);
201 wake_up_process(action->secondary->thread);
202 }
203 }
204}
205
206#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
207static void irq_validate_effective_affinity(struct irq_data *data)
208{
209 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
210 struct irq_chip *chip = irq_data_get_irq_chip(data);
211
212 if (!cpumask_empty(m))
213 return;
214 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
215 chip->name, data->irq);
216}
217#else
218static inline void irq_validate_effective_affinity(struct irq_data *data) { }
219#endif
220
221static DEFINE_PER_CPU(struct cpumask, __tmp_mask);
222
223int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
224 bool force)
225{
226 struct cpumask *tmp_mask = this_cpu_ptr(&__tmp_mask);
227 struct irq_desc *desc = irq_data_to_desc(data);
228 struct irq_chip *chip = irq_data_get_irq_chip(data);
229 const struct cpumask *prog_mask;
230 int ret;
231
232 if (!chip || !chip->irq_set_affinity)
233 return -EINVAL;
234
235 /*
236 * If this is a managed interrupt and housekeeping is enabled on
237 * it check whether the requested affinity mask intersects with
238 * a housekeeping CPU. If so, then remove the isolated CPUs from
239 * the mask and just keep the housekeeping CPU(s). This prevents
240 * the affinity setter from routing the interrupt to an isolated
241 * CPU to avoid that I/O submitted from a housekeeping CPU causes
242 * interrupts on an isolated one.
243 *
244 * If the masks do not intersect or include online CPU(s) then
245 * keep the requested mask. The isolated target CPUs are only
246 * receiving interrupts when the I/O operation was submitted
247 * directly from them.
248 *
249 * If all housekeeping CPUs in the affinity mask are offline, the
250 * interrupt will be migrated by the CPU hotplug code once a
251 * housekeeping CPU which belongs to the affinity mask comes
252 * online.
253 */
254 if (irqd_affinity_is_managed(data) &&
255 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
256 const struct cpumask *hk_mask;
257
258 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
259
260 cpumask_and(tmp_mask, mask, hk_mask);
261 if (!cpumask_intersects(tmp_mask, cpu_online_mask))
262 prog_mask = mask;
263 else
264 prog_mask = tmp_mask;
265 } else {
266 prog_mask = mask;
267 }
268
269 /*
270 * Make sure we only provide online CPUs to the irqchip,
271 * unless we are being asked to force the affinity (in which
272 * case we do as we are told).
273 */
274 cpumask_and(tmp_mask, prog_mask, cpu_online_mask);
275 if (!force && !cpumask_empty(tmp_mask))
276 ret = chip->irq_set_affinity(data, tmp_mask, force);
277 else if (force)
278 ret = chip->irq_set_affinity(data, mask, force);
279 else
280 ret = -EINVAL;
281
282 switch (ret) {
283 case IRQ_SET_MASK_OK:
284 case IRQ_SET_MASK_OK_DONE:
285 cpumask_copy(desc->irq_common_data.affinity, mask);
286 fallthrough;
287 case IRQ_SET_MASK_OK_NOCOPY:
288 irq_validate_effective_affinity(data);
289 irq_set_thread_affinity(desc);
290 ret = 0;
291 }
292
293 return ret;
294}
295
296#ifdef CONFIG_GENERIC_PENDING_IRQ
297static inline int irq_set_affinity_pending(struct irq_data *data,
298 const struct cpumask *dest)
299{
300 struct irq_desc *desc = irq_data_to_desc(data);
301
302 irqd_set_move_pending(data);
303 irq_copy_pending(desc, dest);
304 return 0;
305}
306#else
307static inline int irq_set_affinity_pending(struct irq_data *data,
308 const struct cpumask *dest)
309{
310 return -EBUSY;
311}
312#endif
313
314static int irq_try_set_affinity(struct irq_data *data,
315 const struct cpumask *dest, bool force)
316{
317 int ret = irq_do_set_affinity(data, dest, force);
318
319 /*
320 * In case that the underlying vector management is busy and the
321 * architecture supports the generic pending mechanism then utilize
322 * this to avoid returning an error to user space.
323 */
324 if (ret == -EBUSY && !force)
325 ret = irq_set_affinity_pending(data, dest);
326 return ret;
327}
328
329static bool irq_set_affinity_deactivated(struct irq_data *data,
330 const struct cpumask *mask)
331{
332 struct irq_desc *desc = irq_data_to_desc(data);
333
334 /*
335 * Handle irq chips which can handle affinity only in activated
336 * state correctly
337 *
338 * If the interrupt is not yet activated, just store the affinity
339 * mask and do not call the chip driver at all. On activation the
340 * driver has to make sure anyway that the interrupt is in a
341 * usable state so startup works.
342 */
343 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
344 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
345 return false;
346
347 cpumask_copy(desc->irq_common_data.affinity, mask);
348 irq_data_update_effective_affinity(data, mask);
349 irqd_set(data, IRQD_AFFINITY_SET);
350 return true;
351}
352
353int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
354 bool force)
355{
356 struct irq_chip *chip = irq_data_get_irq_chip(data);
357 struct irq_desc *desc = irq_data_to_desc(data);
358 int ret = 0;
359
360 if (!chip || !chip->irq_set_affinity)
361 return -EINVAL;
362
363 if (irq_set_affinity_deactivated(data, mask))
364 return 0;
365
366 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
367 ret = irq_try_set_affinity(data, mask, force);
368 } else {
369 irqd_set_move_pending(data);
370 irq_copy_pending(desc, mask);
371 }
372
373 if (desc->affinity_notify) {
374 kref_get(&desc->affinity_notify->kref);
375 if (!schedule_work(&desc->affinity_notify->work)) {
376 /* Work was already scheduled, drop our extra ref */
377 kref_put(&desc->affinity_notify->kref,
378 desc->affinity_notify->release);
379 }
380 }
381 irqd_set(data, IRQD_AFFINITY_SET);
382
383 return ret;
384}
385
386/**
387 * irq_update_affinity_desc - Update affinity management for an interrupt
388 * @irq: The interrupt number to update
389 * @affinity: Pointer to the affinity descriptor
390 *
391 * This interface can be used to configure the affinity management of
392 * interrupts which have been allocated already.
393 *
394 * There are certain limitations on when it may be used - attempts to use it
395 * for when the kernel is configured for generic IRQ reservation mode (in
396 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
397 * managed/non-managed interrupt accounting. In addition, attempts to use it on
398 * an interrupt which is already started or which has already been configured
399 * as managed will also fail, as these mean invalid init state or double init.
400 */
401int irq_update_affinity_desc(unsigned int irq,
402 struct irq_affinity_desc *affinity)
403{
404 struct irq_desc *desc;
405 unsigned long flags;
406 bool activated;
407 int ret = 0;
408
409 /*
410 * Supporting this with the reservation scheme used by x86 needs
411 * some more thought. Fail it for now.
412 */
413 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
414 return -EOPNOTSUPP;
415
416 desc = irq_get_desc_buslock(irq, &flags, 0);
417 if (!desc)
418 return -EINVAL;
419
420 /* Requires the interrupt to be shut down */
421 if (irqd_is_started(&desc->irq_data)) {
422 ret = -EBUSY;
423 goto out_unlock;
424 }
425
426 /* Interrupts which are already managed cannot be modified */
427 if (irqd_affinity_is_managed(&desc->irq_data)) {
428 ret = -EBUSY;
429 goto out_unlock;
430 }
431
432 /*
433 * Deactivate the interrupt. That's required to undo
434 * anything an earlier activation has established.
435 */
436 activated = irqd_is_activated(&desc->irq_data);
437 if (activated)
438 irq_domain_deactivate_irq(&desc->irq_data);
439
440 if (affinity->is_managed) {
441 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
442 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
443 }
444
445 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
446
447 /* Restore the activation state */
448 if (activated)
449 irq_domain_activate_irq(&desc->irq_data, false);
450
451out_unlock:
452 irq_put_desc_busunlock(desc, flags);
453 return ret;
454}
455
456static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
457 bool force)
458{
459 struct irq_desc *desc = irq_to_desc(irq);
460 unsigned long flags;
461 int ret;
462
463 if (!desc)
464 return -EINVAL;
465
466 raw_spin_lock_irqsave(&desc->lock, flags);
467 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
468 raw_spin_unlock_irqrestore(&desc->lock, flags);
469 return ret;
470}
471
472/**
473 * irq_set_affinity - Set the irq affinity of a given irq
474 * @irq: Interrupt to set affinity
475 * @cpumask: cpumask
476 *
477 * Fails if cpumask does not contain an online CPU
478 */
479int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
480{
481 return __irq_set_affinity(irq, cpumask, false);
482}
483EXPORT_SYMBOL_GPL(irq_set_affinity);
484
485/**
486 * irq_force_affinity - Force the irq affinity of a given irq
487 * @irq: Interrupt to set affinity
488 * @cpumask: cpumask
489 *
490 * Same as irq_set_affinity, but without checking the mask against
491 * online cpus.
492 *
493 * Solely for low level cpu hotplug code, where we need to make per
494 * cpu interrupts affine before the cpu becomes online.
495 */
496int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
497{
498 return __irq_set_affinity(irq, cpumask, true);
499}
500EXPORT_SYMBOL_GPL(irq_force_affinity);
501
502int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
503 bool setaffinity)
504{
505 unsigned long flags;
506 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
507
508 if (!desc)
509 return -EINVAL;
510 desc->affinity_hint = m;
511 irq_put_desc_unlock(desc, flags);
512 if (m && setaffinity)
513 __irq_set_affinity(irq, m, false);
514 return 0;
515}
516EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
517
518static void irq_affinity_notify(struct work_struct *work)
519{
520 struct irq_affinity_notify *notify =
521 container_of(work, struct irq_affinity_notify, work);
522 struct irq_desc *desc = irq_to_desc(notify->irq);
523 cpumask_var_t cpumask;
524 unsigned long flags;
525
526 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
527 goto out;
528
529 raw_spin_lock_irqsave(&desc->lock, flags);
530 if (irq_move_pending(&desc->irq_data))
531 irq_get_pending(cpumask, desc);
532 else
533 cpumask_copy(cpumask, desc->irq_common_data.affinity);
534 raw_spin_unlock_irqrestore(&desc->lock, flags);
535
536 notify->notify(notify, cpumask);
537
538 free_cpumask_var(cpumask);
539out:
540 kref_put(¬ify->kref, notify->release);
541}
542
543/**
544 * irq_set_affinity_notifier - control notification of IRQ affinity changes
545 * @irq: Interrupt for which to enable/disable notification
546 * @notify: Context for notification, or %NULL to disable
547 * notification. Function pointers must be initialised;
548 * the other fields will be initialised by this function.
549 *
550 * Must be called in process context. Notification may only be enabled
551 * after the IRQ is allocated and must be disabled before the IRQ is
552 * freed using free_irq().
553 */
554int
555irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
556{
557 struct irq_desc *desc = irq_to_desc(irq);
558 struct irq_affinity_notify *old_notify;
559 unsigned long flags;
560
561 /* The release function is promised process context */
562 might_sleep();
563
564 if (!desc || irq_is_nmi(desc))
565 return -EINVAL;
566
567 /* Complete initialisation of *notify */
568 if (notify) {
569 notify->irq = irq;
570 kref_init(¬ify->kref);
571 INIT_WORK(¬ify->work, irq_affinity_notify);
572 }
573
574 raw_spin_lock_irqsave(&desc->lock, flags);
575 old_notify = desc->affinity_notify;
576 desc->affinity_notify = notify;
577 raw_spin_unlock_irqrestore(&desc->lock, flags);
578
579 if (old_notify) {
580 if (cancel_work_sync(&old_notify->work)) {
581 /* Pending work had a ref, put that one too */
582 kref_put(&old_notify->kref, old_notify->release);
583 }
584 kref_put(&old_notify->kref, old_notify->release);
585 }
586
587 return 0;
588}
589EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
590
591#ifndef CONFIG_AUTO_IRQ_AFFINITY
592/*
593 * Generic version of the affinity autoselector.
594 */
595int irq_setup_affinity(struct irq_desc *desc)
596{
597 struct cpumask *set = irq_default_affinity;
598 int ret, node = irq_desc_get_node(desc);
599 static DEFINE_RAW_SPINLOCK(mask_lock);
600 static struct cpumask mask;
601
602 /* Excludes PER_CPU and NO_BALANCE interrupts */
603 if (!__irq_can_set_affinity(desc))
604 return 0;
605
606 raw_spin_lock(&mask_lock);
607 /*
608 * Preserve the managed affinity setting and a userspace affinity
609 * setup, but make sure that one of the targets is online.
610 */
611 if (irqd_affinity_is_managed(&desc->irq_data) ||
612 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
613 if (cpumask_intersects(desc->irq_common_data.affinity,
614 cpu_online_mask))
615 set = desc->irq_common_data.affinity;
616 else
617 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
618 }
619
620 cpumask_and(&mask, cpu_online_mask, set);
621 if (cpumask_empty(&mask))
622 cpumask_copy(&mask, cpu_online_mask);
623
624 if (node != NUMA_NO_NODE) {
625 const struct cpumask *nodemask = cpumask_of_node(node);
626
627 /* make sure at least one of the cpus in nodemask is online */
628 if (cpumask_intersects(&mask, nodemask))
629 cpumask_and(&mask, &mask, nodemask);
630 }
631 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
632 raw_spin_unlock(&mask_lock);
633 return ret;
634}
635#else
636/* Wrapper for ALPHA specific affinity selector magic */
637int irq_setup_affinity(struct irq_desc *desc)
638{
639 return irq_select_affinity(irq_desc_get_irq(desc));
640}
641#endif /* CONFIG_AUTO_IRQ_AFFINITY */
642#endif /* CONFIG_SMP */
643
644
645/**
646 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
647 * @irq: interrupt number to set affinity
648 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
649 * specific data for percpu_devid interrupts
650 *
651 * This function uses the vCPU specific data to set the vCPU
652 * affinity for an irq. The vCPU specific data is passed from
653 * outside, such as KVM. One example code path is as below:
654 * KVM -> IOMMU -> irq_set_vcpu_affinity().
655 */
656int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
657{
658 unsigned long flags;
659 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
660 struct irq_data *data;
661 struct irq_chip *chip;
662 int ret = -ENOSYS;
663
664 if (!desc)
665 return -EINVAL;
666
667 data = irq_desc_get_irq_data(desc);
668 do {
669 chip = irq_data_get_irq_chip(data);
670 if (chip && chip->irq_set_vcpu_affinity)
671 break;
672#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
673 data = data->parent_data;
674#else
675 data = NULL;
676#endif
677 } while (data);
678
679 if (data)
680 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
681 irq_put_desc_unlock(desc, flags);
682
683 return ret;
684}
685EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
686
687void __disable_irq(struct irq_desc *desc)
688{
689 if (!desc->depth++)
690 irq_disable(desc);
691}
692
693static int __disable_irq_nosync(unsigned int irq)
694{
695 unsigned long flags;
696 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
697
698 if (!desc)
699 return -EINVAL;
700 __disable_irq(desc);
701 irq_put_desc_busunlock(desc, flags);
702 return 0;
703}
704
705/**
706 * disable_irq_nosync - disable an irq without waiting
707 * @irq: Interrupt to disable
708 *
709 * Disable the selected interrupt line. Disables and Enables are
710 * nested.
711 * Unlike disable_irq(), this function does not ensure existing
712 * instances of the IRQ handler have completed before returning.
713 *
714 * This function may be called from IRQ context.
715 */
716void disable_irq_nosync(unsigned int irq)
717{
718 __disable_irq_nosync(irq);
719}
720EXPORT_SYMBOL(disable_irq_nosync);
721
722/**
723 * disable_irq - disable an irq and wait for completion
724 * @irq: Interrupt to disable
725 *
726 * Disable the selected interrupt line. Enables and Disables are
727 * nested.
728 * This function waits for any pending IRQ handlers for this interrupt
729 * to complete before returning. If you use this function while
730 * holding a resource the IRQ handler may need you will deadlock.
731 *
732 * Can only be called from preemptible code as it might sleep when
733 * an interrupt thread is associated to @irq.
734 *
735 */
736void disable_irq(unsigned int irq)
737{
738 might_sleep();
739 if (!__disable_irq_nosync(irq))
740 synchronize_irq(irq);
741}
742EXPORT_SYMBOL(disable_irq);
743
744/**
745 * disable_hardirq - disables an irq and waits for hardirq completion
746 * @irq: Interrupt to disable
747 *
748 * Disable the selected interrupt line. Enables and Disables are
749 * nested.
750 * This function waits for any pending hard IRQ handlers for this
751 * interrupt to complete before returning. If you use this function while
752 * holding a resource the hard IRQ handler may need you will deadlock.
753 *
754 * When used to optimistically disable an interrupt from atomic context
755 * the return value must be checked.
756 *
757 * Returns: false if a threaded handler is active.
758 *
759 * This function may be called - with care - from IRQ context.
760 */
761bool disable_hardirq(unsigned int irq)
762{
763 if (!__disable_irq_nosync(irq))
764 return synchronize_hardirq(irq);
765
766 return false;
767}
768EXPORT_SYMBOL_GPL(disable_hardirq);
769
770/**
771 * disable_nmi_nosync - disable an nmi without waiting
772 * @irq: Interrupt to disable
773 *
774 * Disable the selected interrupt line. Disables and enables are
775 * nested.
776 * The interrupt to disable must have been requested through request_nmi.
777 * Unlike disable_nmi(), this function does not ensure existing
778 * instances of the IRQ handler have completed before returning.
779 */
780void disable_nmi_nosync(unsigned int irq)
781{
782 disable_irq_nosync(irq);
783}
784
785void __enable_irq(struct irq_desc *desc)
786{
787 switch (desc->depth) {
788 case 0:
789 err_out:
790 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
791 irq_desc_get_irq(desc));
792 break;
793 case 1: {
794 if (desc->istate & IRQS_SUSPENDED)
795 goto err_out;
796 /* Prevent probing on this irq: */
797 irq_settings_set_noprobe(desc);
798 /*
799 * Call irq_startup() not irq_enable() here because the
800 * interrupt might be marked NOAUTOEN so irq_startup()
801 * needs to be invoked when it gets enabled the first time.
802 * This is also required when __enable_irq() is invoked for
803 * a managed and shutdown interrupt from the S3 resume
804 * path.
805 *
806 * If it was already started up, then irq_startup() will
807 * invoke irq_enable() under the hood.
808 */
809 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
810 break;
811 }
812 default:
813 desc->depth--;
814 }
815}
816
817/**
818 * enable_irq - enable handling of an irq
819 * @irq: Interrupt to enable
820 *
821 * Undoes the effect of one call to disable_irq(). If this
822 * matches the last disable, processing of interrupts on this
823 * IRQ line is re-enabled.
824 *
825 * This function may be called from IRQ context only when
826 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
827 */
828void enable_irq(unsigned int irq)
829{
830 unsigned long flags;
831 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
832
833 if (!desc)
834 return;
835 if (WARN(!desc->irq_data.chip,
836 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
837 goto out;
838
839 __enable_irq(desc);
840out:
841 irq_put_desc_busunlock(desc, flags);
842}
843EXPORT_SYMBOL(enable_irq);
844
845/**
846 * enable_nmi - enable handling of an nmi
847 * @irq: Interrupt to enable
848 *
849 * The interrupt to enable must have been requested through request_nmi.
850 * Undoes the effect of one call to disable_nmi(). If this
851 * matches the last disable, processing of interrupts on this
852 * IRQ line is re-enabled.
853 */
854void enable_nmi(unsigned int irq)
855{
856 enable_irq(irq);
857}
858
859static int set_irq_wake_real(unsigned int irq, unsigned int on)
860{
861 struct irq_desc *desc = irq_to_desc(irq);
862 int ret = -ENXIO;
863
864 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
865 return 0;
866
867 if (desc->irq_data.chip->irq_set_wake)
868 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
869
870 return ret;
871}
872
873/**
874 * irq_set_irq_wake - control irq power management wakeup
875 * @irq: interrupt to control
876 * @on: enable/disable power management wakeup
877 *
878 * Enable/disable power management wakeup mode, which is
879 * disabled by default. Enables and disables must match,
880 * just as they match for non-wakeup mode support.
881 *
882 * Wakeup mode lets this IRQ wake the system from sleep
883 * states like "suspend to RAM".
884 *
885 * Note: irq enable/disable state is completely orthogonal
886 * to the enable/disable state of irq wake. An irq can be
887 * disabled with disable_irq() and still wake the system as
888 * long as the irq has wake enabled. If this does not hold,
889 * then the underlying irq chip and the related driver need
890 * to be investigated.
891 */
892int irq_set_irq_wake(unsigned int irq, unsigned int on)
893{
894 unsigned long flags;
895 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
896 int ret = 0;
897
898 if (!desc)
899 return -EINVAL;
900
901 /* Don't use NMIs as wake up interrupts please */
902 if (irq_is_nmi(desc)) {
903 ret = -EINVAL;
904 goto out_unlock;
905 }
906
907 /* wakeup-capable irqs can be shared between drivers that
908 * don't need to have the same sleep mode behaviors.
909 */
910 if (on) {
911 if (desc->wake_depth++ == 0) {
912 ret = set_irq_wake_real(irq, on);
913 if (ret)
914 desc->wake_depth = 0;
915 else
916 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
917 }
918 } else {
919 if (desc->wake_depth == 0) {
920 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
921 } else if (--desc->wake_depth == 0) {
922 ret = set_irq_wake_real(irq, on);
923 if (ret)
924 desc->wake_depth = 1;
925 else
926 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
927 }
928 }
929
930out_unlock:
931 irq_put_desc_busunlock(desc, flags);
932 return ret;
933}
934EXPORT_SYMBOL(irq_set_irq_wake);
935
936/*
937 * Internal function that tells the architecture code whether a
938 * particular irq has been exclusively allocated or is available
939 * for driver use.
940 */
941int can_request_irq(unsigned int irq, unsigned long irqflags)
942{
943 unsigned long flags;
944 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
945 int canrequest = 0;
946
947 if (!desc)
948 return 0;
949
950 if (irq_settings_can_request(desc)) {
951 if (!desc->action ||
952 irqflags & desc->action->flags & IRQF_SHARED)
953 canrequest = 1;
954 }
955 irq_put_desc_unlock(desc, flags);
956 return canrequest;
957}
958
959int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
960{
961 struct irq_chip *chip = desc->irq_data.chip;
962 int ret, unmask = 0;
963
964 if (!chip || !chip->irq_set_type) {
965 /*
966 * IRQF_TRIGGER_* but the PIC does not support multiple
967 * flow-types?
968 */
969 pr_debug("No set_type function for IRQ %d (%s)\n",
970 irq_desc_get_irq(desc),
971 chip ? (chip->name ? : "unknown") : "unknown");
972 return 0;
973 }
974
975 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
976 if (!irqd_irq_masked(&desc->irq_data))
977 mask_irq(desc);
978 if (!irqd_irq_disabled(&desc->irq_data))
979 unmask = 1;
980 }
981
982 /* Mask all flags except trigger mode */
983 flags &= IRQ_TYPE_SENSE_MASK;
984 ret = chip->irq_set_type(&desc->irq_data, flags);
985
986 switch (ret) {
987 case IRQ_SET_MASK_OK:
988 case IRQ_SET_MASK_OK_DONE:
989 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
990 irqd_set(&desc->irq_data, flags);
991 fallthrough;
992
993 case IRQ_SET_MASK_OK_NOCOPY:
994 flags = irqd_get_trigger_type(&desc->irq_data);
995 irq_settings_set_trigger_mask(desc, flags);
996 irqd_clear(&desc->irq_data, IRQD_LEVEL);
997 irq_settings_clr_level(desc);
998 if (flags & IRQ_TYPE_LEVEL_MASK) {
999 irq_settings_set_level(desc);
1000 irqd_set(&desc->irq_data, IRQD_LEVEL);
1001 }
1002
1003 ret = 0;
1004 break;
1005 default:
1006 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
1007 flags, irq_desc_get_irq(desc), chip->irq_set_type);
1008 }
1009 if (unmask)
1010 unmask_irq(desc);
1011 return ret;
1012}
1013
1014#ifdef CONFIG_HARDIRQS_SW_RESEND
1015int irq_set_parent(int irq, int parent_irq)
1016{
1017 unsigned long flags;
1018 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1019
1020 if (!desc)
1021 return -EINVAL;
1022
1023 desc->parent_irq = parent_irq;
1024
1025 irq_put_desc_unlock(desc, flags);
1026 return 0;
1027}
1028EXPORT_SYMBOL_GPL(irq_set_parent);
1029#endif
1030
1031/*
1032 * Default primary interrupt handler for threaded interrupts. Is
1033 * assigned as primary handler when request_threaded_irq is called
1034 * with handler == NULL. Useful for oneshot interrupts.
1035 */
1036static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1037{
1038 return IRQ_WAKE_THREAD;
1039}
1040
1041/*
1042 * Primary handler for nested threaded interrupts. Should never be
1043 * called.
1044 */
1045static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1046{
1047 WARN(1, "Primary handler called for nested irq %d\n", irq);
1048 return IRQ_NONE;
1049}
1050
1051static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1052{
1053 WARN(1, "Secondary action handler called for irq %d\n", irq);
1054 return IRQ_NONE;
1055}
1056
1057#ifdef CONFIG_SMP
1058/*
1059 * Check whether we need to change the affinity of the interrupt thread.
1060 */
1061static void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1062{
1063 cpumask_var_t mask;
1064 bool valid = false;
1065
1066 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1067 return;
1068
1069 __set_current_state(TASK_RUNNING);
1070
1071 /*
1072 * In case we are out of memory we set IRQTF_AFFINITY again and
1073 * try again next time
1074 */
1075 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1076 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1077 return;
1078 }
1079
1080 raw_spin_lock_irq(&desc->lock);
1081 /*
1082 * This code is triggered unconditionally. Check the affinity
1083 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1084 */
1085 if (cpumask_available(desc->irq_common_data.affinity)) {
1086 const struct cpumask *m;
1087
1088 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1089 cpumask_copy(mask, m);
1090 valid = true;
1091 }
1092 raw_spin_unlock_irq(&desc->lock);
1093
1094 if (valid)
1095 set_cpus_allowed_ptr(current, mask);
1096 free_cpumask_var(mask);
1097}
1098#else
1099static inline void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1100#endif
1101
1102static int irq_wait_for_interrupt(struct irq_desc *desc,
1103 struct irqaction *action)
1104{
1105 for (;;) {
1106 set_current_state(TASK_INTERRUPTIBLE);
1107 irq_thread_check_affinity(desc, action);
1108
1109 if (kthread_should_stop()) {
1110 /* may need to run one last time */
1111 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1112 &action->thread_flags)) {
1113 __set_current_state(TASK_RUNNING);
1114 return 0;
1115 }
1116 __set_current_state(TASK_RUNNING);
1117 return -1;
1118 }
1119
1120 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1121 &action->thread_flags)) {
1122 __set_current_state(TASK_RUNNING);
1123 return 0;
1124 }
1125 schedule();
1126 }
1127}
1128
1129/*
1130 * Oneshot interrupts keep the irq line masked until the threaded
1131 * handler finished. unmask if the interrupt has not been disabled and
1132 * is marked MASKED.
1133 */
1134static void irq_finalize_oneshot(struct irq_desc *desc,
1135 struct irqaction *action)
1136{
1137 if (!(desc->istate & IRQS_ONESHOT) ||
1138 action->handler == irq_forced_secondary_handler)
1139 return;
1140again:
1141 chip_bus_lock(desc);
1142 raw_spin_lock_irq(&desc->lock);
1143
1144 /*
1145 * Implausible though it may be we need to protect us against
1146 * the following scenario:
1147 *
1148 * The thread is faster done than the hard interrupt handler
1149 * on the other CPU. If we unmask the irq line then the
1150 * interrupt can come in again and masks the line, leaves due
1151 * to IRQS_INPROGRESS and the irq line is masked forever.
1152 *
1153 * This also serializes the state of shared oneshot handlers
1154 * versus "desc->threads_oneshot |= action->thread_mask;" in
1155 * irq_wake_thread(). See the comment there which explains the
1156 * serialization.
1157 */
1158 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1159 raw_spin_unlock_irq(&desc->lock);
1160 chip_bus_sync_unlock(desc);
1161 cpu_relax();
1162 goto again;
1163 }
1164
1165 /*
1166 * Now check again, whether the thread should run. Otherwise
1167 * we would clear the threads_oneshot bit of this thread which
1168 * was just set.
1169 */
1170 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1171 goto out_unlock;
1172
1173 desc->threads_oneshot &= ~action->thread_mask;
1174
1175 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1176 irqd_irq_masked(&desc->irq_data))
1177 unmask_threaded_irq(desc);
1178
1179out_unlock:
1180 raw_spin_unlock_irq(&desc->lock);
1181 chip_bus_sync_unlock(desc);
1182}
1183
1184/*
1185 * Interrupts which are not explicitly requested as threaded
1186 * interrupts rely on the implicit bh/preempt disable of the hard irq
1187 * context. So we need to disable bh here to avoid deadlocks and other
1188 * side effects.
1189 */
1190static irqreturn_t
1191irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1192{
1193 irqreturn_t ret;
1194
1195 local_bh_disable();
1196 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1197 local_irq_disable();
1198 ret = action->thread_fn(action->irq, action->dev_id);
1199 if (ret == IRQ_HANDLED)
1200 atomic_inc(&desc->threads_handled);
1201
1202 irq_finalize_oneshot(desc, action);
1203 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1204 local_irq_enable();
1205 local_bh_enable();
1206 return ret;
1207}
1208
1209/*
1210 * Interrupts explicitly requested as threaded interrupts want to be
1211 * preemptible - many of them need to sleep and wait for slow busses to
1212 * complete.
1213 */
1214static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1215 struct irqaction *action)
1216{
1217 irqreturn_t ret;
1218
1219 ret = action->thread_fn(action->irq, action->dev_id);
1220 if (ret == IRQ_HANDLED)
1221 atomic_inc(&desc->threads_handled);
1222
1223 irq_finalize_oneshot(desc, action);
1224 return ret;
1225}
1226
1227void wake_threads_waitq(struct irq_desc *desc)
1228{
1229 if (atomic_dec_and_test(&desc->threads_active))
1230 wake_up(&desc->wait_for_threads);
1231}
1232
1233static void irq_thread_dtor(struct callback_head *unused)
1234{
1235 struct task_struct *tsk = current;
1236 struct irq_desc *desc;
1237 struct irqaction *action;
1238
1239 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1240 return;
1241
1242 action = kthread_data(tsk);
1243
1244 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1245 tsk->comm, tsk->pid, action->irq);
1246
1247
1248 desc = irq_to_desc(action->irq);
1249 /*
1250 * If IRQTF_RUNTHREAD is set, we need to decrement
1251 * desc->threads_active and wake possible waiters.
1252 */
1253 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1254 wake_threads_waitq(desc);
1255
1256 /* Prevent a stale desc->threads_oneshot */
1257 irq_finalize_oneshot(desc, action);
1258}
1259
1260static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1261{
1262 struct irqaction *secondary = action->secondary;
1263
1264 if (WARN_ON_ONCE(!secondary))
1265 return;
1266
1267 raw_spin_lock_irq(&desc->lock);
1268 __irq_wake_thread(desc, secondary);
1269 raw_spin_unlock_irq(&desc->lock);
1270}
1271
1272/*
1273 * Internal function to notify that a interrupt thread is ready.
1274 */
1275static void irq_thread_set_ready(struct irq_desc *desc,
1276 struct irqaction *action)
1277{
1278 set_bit(IRQTF_READY, &action->thread_flags);
1279 wake_up(&desc->wait_for_threads);
1280}
1281
1282/*
1283 * Internal function to wake up a interrupt thread and wait until it is
1284 * ready.
1285 */
1286static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1287 struct irqaction *action)
1288{
1289 if (!action || !action->thread)
1290 return;
1291
1292 wake_up_process(action->thread);
1293 wait_event(desc->wait_for_threads,
1294 test_bit(IRQTF_READY, &action->thread_flags));
1295}
1296
1297/*
1298 * Interrupt handler thread
1299 */
1300static int irq_thread(void *data)
1301{
1302 struct callback_head on_exit_work;
1303 struct irqaction *action = data;
1304 struct irq_desc *desc = irq_to_desc(action->irq);
1305 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1306 struct irqaction *action);
1307
1308 irq_thread_set_ready(desc, action);
1309
1310 sched_set_fifo(current);
1311
1312 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1313 &action->thread_flags))
1314 handler_fn = irq_forced_thread_fn;
1315 else
1316 handler_fn = irq_thread_fn;
1317
1318 init_task_work(&on_exit_work, irq_thread_dtor);
1319 task_work_add(current, &on_exit_work, TWA_NONE);
1320
1321 while (!irq_wait_for_interrupt(desc, action)) {
1322 irqreturn_t action_ret;
1323
1324 action_ret = handler_fn(desc, action);
1325 if (action_ret == IRQ_WAKE_THREAD)
1326 irq_wake_secondary(desc, action);
1327
1328 wake_threads_waitq(desc);
1329 }
1330
1331 /*
1332 * This is the regular exit path. __free_irq() is stopping the
1333 * thread via kthread_stop() after calling
1334 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1335 * oneshot mask bit can be set.
1336 */
1337 task_work_cancel_func(current, irq_thread_dtor);
1338 return 0;
1339}
1340
1341/**
1342 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1343 * @irq: Interrupt line
1344 * @dev_id: Device identity for which the thread should be woken
1345 *
1346 */
1347void irq_wake_thread(unsigned int irq, void *dev_id)
1348{
1349 struct irq_desc *desc = irq_to_desc(irq);
1350 struct irqaction *action;
1351 unsigned long flags;
1352
1353 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1354 return;
1355
1356 raw_spin_lock_irqsave(&desc->lock, flags);
1357 for_each_action_of_desc(desc, action) {
1358 if (action->dev_id == dev_id) {
1359 if (action->thread)
1360 __irq_wake_thread(desc, action);
1361 break;
1362 }
1363 }
1364 raw_spin_unlock_irqrestore(&desc->lock, flags);
1365}
1366EXPORT_SYMBOL_GPL(irq_wake_thread);
1367
1368static int irq_setup_forced_threading(struct irqaction *new)
1369{
1370 if (!force_irqthreads())
1371 return 0;
1372 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1373 return 0;
1374
1375 /*
1376 * No further action required for interrupts which are requested as
1377 * threaded interrupts already
1378 */
1379 if (new->handler == irq_default_primary_handler)
1380 return 0;
1381
1382 new->flags |= IRQF_ONESHOT;
1383
1384 /*
1385 * Handle the case where we have a real primary handler and a
1386 * thread handler. We force thread them as well by creating a
1387 * secondary action.
1388 */
1389 if (new->handler && new->thread_fn) {
1390 /* Allocate the secondary action */
1391 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1392 if (!new->secondary)
1393 return -ENOMEM;
1394 new->secondary->handler = irq_forced_secondary_handler;
1395 new->secondary->thread_fn = new->thread_fn;
1396 new->secondary->dev_id = new->dev_id;
1397 new->secondary->irq = new->irq;
1398 new->secondary->name = new->name;
1399 }
1400 /* Deal with the primary handler */
1401 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1402 new->thread_fn = new->handler;
1403 new->handler = irq_default_primary_handler;
1404 return 0;
1405}
1406
1407static int irq_request_resources(struct irq_desc *desc)
1408{
1409 struct irq_data *d = &desc->irq_data;
1410 struct irq_chip *c = d->chip;
1411
1412 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1413}
1414
1415static void irq_release_resources(struct irq_desc *desc)
1416{
1417 struct irq_data *d = &desc->irq_data;
1418 struct irq_chip *c = d->chip;
1419
1420 if (c->irq_release_resources)
1421 c->irq_release_resources(d);
1422}
1423
1424static bool irq_supports_nmi(struct irq_desc *desc)
1425{
1426 struct irq_data *d = irq_desc_get_irq_data(desc);
1427
1428#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1429 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1430 if (d->parent_data)
1431 return false;
1432#endif
1433 /* Don't support NMIs for chips behind a slow bus */
1434 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1435 return false;
1436
1437 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1438}
1439
1440static int irq_nmi_setup(struct irq_desc *desc)
1441{
1442 struct irq_data *d = irq_desc_get_irq_data(desc);
1443 struct irq_chip *c = d->chip;
1444
1445 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1446}
1447
1448static void irq_nmi_teardown(struct irq_desc *desc)
1449{
1450 struct irq_data *d = irq_desc_get_irq_data(desc);
1451 struct irq_chip *c = d->chip;
1452
1453 if (c->irq_nmi_teardown)
1454 c->irq_nmi_teardown(d);
1455}
1456
1457static int
1458setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1459{
1460 struct task_struct *t;
1461
1462 if (!secondary) {
1463 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1464 new->name);
1465 } else {
1466 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1467 new->name);
1468 }
1469
1470 if (IS_ERR(t))
1471 return PTR_ERR(t);
1472
1473 /*
1474 * We keep the reference to the task struct even if
1475 * the thread dies to avoid that the interrupt code
1476 * references an already freed task_struct.
1477 */
1478 new->thread = get_task_struct(t);
1479 /*
1480 * Tell the thread to set its affinity. This is
1481 * important for shared interrupt handlers as we do
1482 * not invoke setup_affinity() for the secondary
1483 * handlers as everything is already set up. Even for
1484 * interrupts marked with IRQF_NO_BALANCE this is
1485 * correct as we want the thread to move to the cpu(s)
1486 * on which the requesting code placed the interrupt.
1487 */
1488 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1489 return 0;
1490}
1491
1492/*
1493 * Internal function to register an irqaction - typically used to
1494 * allocate special interrupts that are part of the architecture.
1495 *
1496 * Locking rules:
1497 *
1498 * desc->request_mutex Provides serialization against a concurrent free_irq()
1499 * chip_bus_lock Provides serialization for slow bus operations
1500 * desc->lock Provides serialization against hard interrupts
1501 *
1502 * chip_bus_lock and desc->lock are sufficient for all other management and
1503 * interrupt related functions. desc->request_mutex solely serializes
1504 * request/free_irq().
1505 */
1506static int
1507__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1508{
1509 struct irqaction *old, **old_ptr;
1510 unsigned long flags, thread_mask = 0;
1511 int ret, nested, shared = 0;
1512
1513 if (!desc)
1514 return -EINVAL;
1515
1516 if (desc->irq_data.chip == &no_irq_chip)
1517 return -ENOSYS;
1518 if (!try_module_get(desc->owner))
1519 return -ENODEV;
1520
1521 new->irq = irq;
1522
1523 /*
1524 * If the trigger type is not specified by the caller,
1525 * then use the default for this interrupt.
1526 */
1527 if (!(new->flags & IRQF_TRIGGER_MASK))
1528 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1529
1530 /*
1531 * Check whether the interrupt nests into another interrupt
1532 * thread.
1533 */
1534 nested = irq_settings_is_nested_thread(desc);
1535 if (nested) {
1536 if (!new->thread_fn) {
1537 ret = -EINVAL;
1538 goto out_mput;
1539 }
1540 /*
1541 * Replace the primary handler which was provided from
1542 * the driver for non nested interrupt handling by the
1543 * dummy function which warns when called.
1544 */
1545 new->handler = irq_nested_primary_handler;
1546 } else {
1547 if (irq_settings_can_thread(desc)) {
1548 ret = irq_setup_forced_threading(new);
1549 if (ret)
1550 goto out_mput;
1551 }
1552 }
1553
1554 /*
1555 * Create a handler thread when a thread function is supplied
1556 * and the interrupt does not nest into another interrupt
1557 * thread.
1558 */
1559 if (new->thread_fn && !nested) {
1560 ret = setup_irq_thread(new, irq, false);
1561 if (ret)
1562 goto out_mput;
1563 if (new->secondary) {
1564 ret = setup_irq_thread(new->secondary, irq, true);
1565 if (ret)
1566 goto out_thread;
1567 }
1568 }
1569
1570 /*
1571 * Drivers are often written to work w/o knowledge about the
1572 * underlying irq chip implementation, so a request for a
1573 * threaded irq without a primary hard irq context handler
1574 * requires the ONESHOT flag to be set. Some irq chips like
1575 * MSI based interrupts are per se one shot safe. Check the
1576 * chip flags, so we can avoid the unmask dance at the end of
1577 * the threaded handler for those.
1578 */
1579 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1580 new->flags &= ~IRQF_ONESHOT;
1581
1582 /*
1583 * Protects against a concurrent __free_irq() call which might wait
1584 * for synchronize_hardirq() to complete without holding the optional
1585 * chip bus lock and desc->lock. Also protects against handing out
1586 * a recycled oneshot thread_mask bit while it's still in use by
1587 * its previous owner.
1588 */
1589 mutex_lock(&desc->request_mutex);
1590
1591 /*
1592 * Acquire bus lock as the irq_request_resources() callback below
1593 * might rely on the serialization or the magic power management
1594 * functions which are abusing the irq_bus_lock() callback,
1595 */
1596 chip_bus_lock(desc);
1597
1598 /* First installed action requests resources. */
1599 if (!desc->action) {
1600 ret = irq_request_resources(desc);
1601 if (ret) {
1602 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1603 new->name, irq, desc->irq_data.chip->name);
1604 goto out_bus_unlock;
1605 }
1606 }
1607
1608 /*
1609 * The following block of code has to be executed atomically
1610 * protected against a concurrent interrupt and any of the other
1611 * management calls which are not serialized via
1612 * desc->request_mutex or the optional bus lock.
1613 */
1614 raw_spin_lock_irqsave(&desc->lock, flags);
1615 old_ptr = &desc->action;
1616 old = *old_ptr;
1617 if (old) {
1618 /*
1619 * Can't share interrupts unless both agree to and are
1620 * the same type (level, edge, polarity). So both flag
1621 * fields must have IRQF_SHARED set and the bits which
1622 * set the trigger type must match. Also all must
1623 * agree on ONESHOT.
1624 * Interrupt lines used for NMIs cannot be shared.
1625 */
1626 unsigned int oldtype;
1627
1628 if (irq_is_nmi(desc)) {
1629 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1630 new->name, irq, desc->irq_data.chip->name);
1631 ret = -EINVAL;
1632 goto out_unlock;
1633 }
1634
1635 /*
1636 * If nobody did set the configuration before, inherit
1637 * the one provided by the requester.
1638 */
1639 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1640 oldtype = irqd_get_trigger_type(&desc->irq_data);
1641 } else {
1642 oldtype = new->flags & IRQF_TRIGGER_MASK;
1643 irqd_set_trigger_type(&desc->irq_data, oldtype);
1644 }
1645
1646 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1647 (oldtype != (new->flags & IRQF_TRIGGER_MASK)))
1648 goto mismatch;
1649
1650 if ((old->flags & IRQF_ONESHOT) &&
1651 (new->flags & IRQF_COND_ONESHOT))
1652 new->flags |= IRQF_ONESHOT;
1653 else if ((old->flags ^ new->flags) & IRQF_ONESHOT)
1654 goto mismatch;
1655
1656 /* All handlers must agree on per-cpuness */
1657 if ((old->flags & IRQF_PERCPU) !=
1658 (new->flags & IRQF_PERCPU))
1659 goto mismatch;
1660
1661 /* add new interrupt at end of irq queue */
1662 do {
1663 /*
1664 * Or all existing action->thread_mask bits,
1665 * so we can find the next zero bit for this
1666 * new action.
1667 */
1668 thread_mask |= old->thread_mask;
1669 old_ptr = &old->next;
1670 old = *old_ptr;
1671 } while (old);
1672 shared = 1;
1673 }
1674
1675 /*
1676 * Setup the thread mask for this irqaction for ONESHOT. For
1677 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1678 * conditional in irq_wake_thread().
1679 */
1680 if (new->flags & IRQF_ONESHOT) {
1681 /*
1682 * Unlikely to have 32 resp 64 irqs sharing one line,
1683 * but who knows.
1684 */
1685 if (thread_mask == ~0UL) {
1686 ret = -EBUSY;
1687 goto out_unlock;
1688 }
1689 /*
1690 * The thread_mask for the action is or'ed to
1691 * desc->thread_active to indicate that the
1692 * IRQF_ONESHOT thread handler has been woken, but not
1693 * yet finished. The bit is cleared when a thread
1694 * completes. When all threads of a shared interrupt
1695 * line have completed desc->threads_active becomes
1696 * zero and the interrupt line is unmasked. See
1697 * handle.c:irq_wake_thread() for further information.
1698 *
1699 * If no thread is woken by primary (hard irq context)
1700 * interrupt handlers, then desc->threads_active is
1701 * also checked for zero to unmask the irq line in the
1702 * affected hard irq flow handlers
1703 * (handle_[fasteoi|level]_irq).
1704 *
1705 * The new action gets the first zero bit of
1706 * thread_mask assigned. See the loop above which or's
1707 * all existing action->thread_mask bits.
1708 */
1709 new->thread_mask = 1UL << ffz(thread_mask);
1710
1711 } else if (new->handler == irq_default_primary_handler &&
1712 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1713 /*
1714 * The interrupt was requested with handler = NULL, so
1715 * we use the default primary handler for it. But it
1716 * does not have the oneshot flag set. In combination
1717 * with level interrupts this is deadly, because the
1718 * default primary handler just wakes the thread, then
1719 * the irq lines is reenabled, but the device still
1720 * has the level irq asserted. Rinse and repeat....
1721 *
1722 * While this works for edge type interrupts, we play
1723 * it safe and reject unconditionally because we can't
1724 * say for sure which type this interrupt really
1725 * has. The type flags are unreliable as the
1726 * underlying chip implementation can override them.
1727 */
1728 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1729 new->name, irq);
1730 ret = -EINVAL;
1731 goto out_unlock;
1732 }
1733
1734 if (!shared) {
1735 /* Setup the type (level, edge polarity) if configured: */
1736 if (new->flags & IRQF_TRIGGER_MASK) {
1737 ret = __irq_set_trigger(desc,
1738 new->flags & IRQF_TRIGGER_MASK);
1739
1740 if (ret)
1741 goto out_unlock;
1742 }
1743
1744 /*
1745 * Activate the interrupt. That activation must happen
1746 * independently of IRQ_NOAUTOEN. request_irq() can fail
1747 * and the callers are supposed to handle
1748 * that. enable_irq() of an interrupt requested with
1749 * IRQ_NOAUTOEN is not supposed to fail. The activation
1750 * keeps it in shutdown mode, it merily associates
1751 * resources if necessary and if that's not possible it
1752 * fails. Interrupts which are in managed shutdown mode
1753 * will simply ignore that activation request.
1754 */
1755 ret = irq_activate(desc);
1756 if (ret)
1757 goto out_unlock;
1758
1759 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1760 IRQS_ONESHOT | IRQS_WAITING);
1761 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1762
1763 if (new->flags & IRQF_PERCPU) {
1764 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1765 irq_settings_set_per_cpu(desc);
1766 if (new->flags & IRQF_NO_DEBUG)
1767 irq_settings_set_no_debug(desc);
1768 }
1769
1770 if (noirqdebug)
1771 irq_settings_set_no_debug(desc);
1772
1773 if (new->flags & IRQF_ONESHOT)
1774 desc->istate |= IRQS_ONESHOT;
1775
1776 /* Exclude IRQ from balancing if requested */
1777 if (new->flags & IRQF_NOBALANCING) {
1778 irq_settings_set_no_balancing(desc);
1779 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1780 }
1781
1782 if (!(new->flags & IRQF_NO_AUTOEN) &&
1783 irq_settings_can_autoenable(desc)) {
1784 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1785 } else {
1786 /*
1787 * Shared interrupts do not go well with disabling
1788 * auto enable. The sharing interrupt might request
1789 * it while it's still disabled and then wait for
1790 * interrupts forever.
1791 */
1792 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1793 /* Undo nested disables: */
1794 desc->depth = 1;
1795 }
1796
1797 } else if (new->flags & IRQF_TRIGGER_MASK) {
1798 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1799 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1800
1801 if (nmsk != omsk)
1802 /* hope the handler works with current trigger mode */
1803 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1804 irq, omsk, nmsk);
1805 }
1806
1807 *old_ptr = new;
1808
1809 irq_pm_install_action(desc, new);
1810
1811 /* Reset broken irq detection when installing new handler */
1812 desc->irq_count = 0;
1813 desc->irqs_unhandled = 0;
1814
1815 /*
1816 * Check whether we disabled the irq via the spurious handler
1817 * before. Reenable it and give it another chance.
1818 */
1819 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1820 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1821 __enable_irq(desc);
1822 }
1823
1824 raw_spin_unlock_irqrestore(&desc->lock, flags);
1825 chip_bus_sync_unlock(desc);
1826 mutex_unlock(&desc->request_mutex);
1827
1828 irq_setup_timings(desc, new);
1829
1830 wake_up_and_wait_for_irq_thread_ready(desc, new);
1831 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1832
1833 register_irq_proc(irq, desc);
1834 new->dir = NULL;
1835 register_handler_proc(irq, new);
1836 return 0;
1837
1838mismatch:
1839 if (!(new->flags & IRQF_PROBE_SHARED)) {
1840 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1841 irq, new->flags, new->name, old->flags, old->name);
1842#ifdef CONFIG_DEBUG_SHIRQ
1843 dump_stack();
1844#endif
1845 }
1846 ret = -EBUSY;
1847
1848out_unlock:
1849 raw_spin_unlock_irqrestore(&desc->lock, flags);
1850
1851 if (!desc->action)
1852 irq_release_resources(desc);
1853out_bus_unlock:
1854 chip_bus_sync_unlock(desc);
1855 mutex_unlock(&desc->request_mutex);
1856
1857out_thread:
1858 if (new->thread) {
1859 struct task_struct *t = new->thread;
1860
1861 new->thread = NULL;
1862 kthread_stop_put(t);
1863 }
1864 if (new->secondary && new->secondary->thread) {
1865 struct task_struct *t = new->secondary->thread;
1866
1867 new->secondary->thread = NULL;
1868 kthread_stop_put(t);
1869 }
1870out_mput:
1871 module_put(desc->owner);
1872 return ret;
1873}
1874
1875/*
1876 * Internal function to unregister an irqaction - used to free
1877 * regular and special interrupts that are part of the architecture.
1878 */
1879static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1880{
1881 unsigned irq = desc->irq_data.irq;
1882 struct irqaction *action, **action_ptr;
1883 unsigned long flags;
1884
1885 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1886
1887 mutex_lock(&desc->request_mutex);
1888 chip_bus_lock(desc);
1889 raw_spin_lock_irqsave(&desc->lock, flags);
1890
1891 /*
1892 * There can be multiple actions per IRQ descriptor, find the right
1893 * one based on the dev_id:
1894 */
1895 action_ptr = &desc->action;
1896 for (;;) {
1897 action = *action_ptr;
1898
1899 if (!action) {
1900 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1901 raw_spin_unlock_irqrestore(&desc->lock, flags);
1902 chip_bus_sync_unlock(desc);
1903 mutex_unlock(&desc->request_mutex);
1904 return NULL;
1905 }
1906
1907 if (action->dev_id == dev_id)
1908 break;
1909 action_ptr = &action->next;
1910 }
1911
1912 /* Found it - now remove it from the list of entries: */
1913 *action_ptr = action->next;
1914
1915 irq_pm_remove_action(desc, action);
1916
1917 /* If this was the last handler, shut down the IRQ line: */
1918 if (!desc->action) {
1919 irq_settings_clr_disable_unlazy(desc);
1920 /* Only shutdown. Deactivate after synchronize_hardirq() */
1921 irq_shutdown(desc);
1922 }
1923
1924#ifdef CONFIG_SMP
1925 /* make sure affinity_hint is cleaned up */
1926 if (WARN_ON_ONCE(desc->affinity_hint))
1927 desc->affinity_hint = NULL;
1928#endif
1929
1930 raw_spin_unlock_irqrestore(&desc->lock, flags);
1931 /*
1932 * Drop bus_lock here so the changes which were done in the chip
1933 * callbacks above are synced out to the irq chips which hang
1934 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1935 *
1936 * Aside of that the bus_lock can also be taken from the threaded
1937 * handler in irq_finalize_oneshot() which results in a deadlock
1938 * because kthread_stop() would wait forever for the thread to
1939 * complete, which is blocked on the bus lock.
1940 *
1941 * The still held desc->request_mutex() protects against a
1942 * concurrent request_irq() of this irq so the release of resources
1943 * and timing data is properly serialized.
1944 */
1945 chip_bus_sync_unlock(desc);
1946
1947 unregister_handler_proc(irq, action);
1948
1949 /*
1950 * Make sure it's not being used on another CPU and if the chip
1951 * supports it also make sure that there is no (not yet serviced)
1952 * interrupt in flight at the hardware level.
1953 */
1954 __synchronize_irq(desc);
1955
1956#ifdef CONFIG_DEBUG_SHIRQ
1957 /*
1958 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1959 * event to happen even now it's being freed, so let's make sure that
1960 * is so by doing an extra call to the handler ....
1961 *
1962 * ( We do this after actually deregistering it, to make sure that a
1963 * 'real' IRQ doesn't run in parallel with our fake. )
1964 */
1965 if (action->flags & IRQF_SHARED) {
1966 local_irq_save(flags);
1967 action->handler(irq, dev_id);
1968 local_irq_restore(flags);
1969 }
1970#endif
1971
1972 /*
1973 * The action has already been removed above, but the thread writes
1974 * its oneshot mask bit when it completes. Though request_mutex is
1975 * held across this which prevents __setup_irq() from handing out
1976 * the same bit to a newly requested action.
1977 */
1978 if (action->thread) {
1979 kthread_stop_put(action->thread);
1980 if (action->secondary && action->secondary->thread)
1981 kthread_stop_put(action->secondary->thread);
1982 }
1983
1984 /* Last action releases resources */
1985 if (!desc->action) {
1986 /*
1987 * Reacquire bus lock as irq_release_resources() might
1988 * require it to deallocate resources over the slow bus.
1989 */
1990 chip_bus_lock(desc);
1991 /*
1992 * There is no interrupt on the fly anymore. Deactivate it
1993 * completely.
1994 */
1995 raw_spin_lock_irqsave(&desc->lock, flags);
1996 irq_domain_deactivate_irq(&desc->irq_data);
1997 raw_spin_unlock_irqrestore(&desc->lock, flags);
1998
1999 irq_release_resources(desc);
2000 chip_bus_sync_unlock(desc);
2001 irq_remove_timings(desc);
2002 }
2003
2004 mutex_unlock(&desc->request_mutex);
2005
2006 irq_chip_pm_put(&desc->irq_data);
2007 module_put(desc->owner);
2008 kfree(action->secondary);
2009 return action;
2010}
2011
2012/**
2013 * free_irq - free an interrupt allocated with request_irq
2014 * @irq: Interrupt line to free
2015 * @dev_id: Device identity to free
2016 *
2017 * Remove an interrupt handler. The handler is removed and if the
2018 * interrupt line is no longer in use by any driver it is disabled.
2019 * On a shared IRQ the caller must ensure the interrupt is disabled
2020 * on the card it drives before calling this function. The function
2021 * does not return until any executing interrupts for this IRQ
2022 * have completed.
2023 *
2024 * This function must not be called from interrupt context.
2025 *
2026 * Returns the devname argument passed to request_irq.
2027 */
2028const void *free_irq(unsigned int irq, void *dev_id)
2029{
2030 struct irq_desc *desc = irq_to_desc(irq);
2031 struct irqaction *action;
2032 const char *devname;
2033
2034 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2035 return NULL;
2036
2037#ifdef CONFIG_SMP
2038 if (WARN_ON(desc->affinity_notify))
2039 desc->affinity_notify = NULL;
2040#endif
2041
2042 action = __free_irq(desc, dev_id);
2043
2044 if (!action)
2045 return NULL;
2046
2047 devname = action->name;
2048 kfree(action);
2049 return devname;
2050}
2051EXPORT_SYMBOL(free_irq);
2052
2053/* This function must be called with desc->lock held */
2054static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2055{
2056 const char *devname = NULL;
2057
2058 desc->istate &= ~IRQS_NMI;
2059
2060 if (!WARN_ON(desc->action == NULL)) {
2061 irq_pm_remove_action(desc, desc->action);
2062 devname = desc->action->name;
2063 unregister_handler_proc(irq, desc->action);
2064
2065 kfree(desc->action);
2066 desc->action = NULL;
2067 }
2068
2069 irq_settings_clr_disable_unlazy(desc);
2070 irq_shutdown_and_deactivate(desc);
2071
2072 irq_release_resources(desc);
2073
2074 irq_chip_pm_put(&desc->irq_data);
2075 module_put(desc->owner);
2076
2077 return devname;
2078}
2079
2080const void *free_nmi(unsigned int irq, void *dev_id)
2081{
2082 struct irq_desc *desc = irq_to_desc(irq);
2083 unsigned long flags;
2084 const void *devname;
2085
2086 if (!desc || WARN_ON(!irq_is_nmi(desc)))
2087 return NULL;
2088
2089 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2090 return NULL;
2091
2092 /* NMI still enabled */
2093 if (WARN_ON(desc->depth == 0))
2094 disable_nmi_nosync(irq);
2095
2096 raw_spin_lock_irqsave(&desc->lock, flags);
2097
2098 irq_nmi_teardown(desc);
2099 devname = __cleanup_nmi(irq, desc);
2100
2101 raw_spin_unlock_irqrestore(&desc->lock, flags);
2102
2103 return devname;
2104}
2105
2106/**
2107 * request_threaded_irq - allocate an interrupt line
2108 * @irq: Interrupt line to allocate
2109 * @handler: Function to be called when the IRQ occurs.
2110 * Primary handler for threaded interrupts.
2111 * If handler is NULL and thread_fn != NULL
2112 * the default primary handler is installed.
2113 * @thread_fn: Function called from the irq handler thread
2114 * If NULL, no irq thread is created
2115 * @irqflags: Interrupt type flags
2116 * @devname: An ascii name for the claiming device
2117 * @dev_id: A cookie passed back to the handler function
2118 *
2119 * This call allocates interrupt resources and enables the
2120 * interrupt line and IRQ handling. From the point this
2121 * call is made your handler function may be invoked. Since
2122 * your handler function must clear any interrupt the board
2123 * raises, you must take care both to initialise your hardware
2124 * and to set up the interrupt handler in the right order.
2125 *
2126 * If you want to set up a threaded irq handler for your device
2127 * then you need to supply @handler and @thread_fn. @handler is
2128 * still called in hard interrupt context and has to check
2129 * whether the interrupt originates from the device. If yes it
2130 * needs to disable the interrupt on the device and return
2131 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2132 * @thread_fn. This split handler design is necessary to support
2133 * shared interrupts.
2134 *
2135 * Dev_id must be globally unique. Normally the address of the
2136 * device data structure is used as the cookie. Since the handler
2137 * receives this value it makes sense to use it.
2138 *
2139 * If your interrupt is shared you must pass a non NULL dev_id
2140 * as this is required when freeing the interrupt.
2141 *
2142 * Flags:
2143 *
2144 * IRQF_SHARED Interrupt is shared
2145 * IRQF_TRIGGER_* Specify active edge(s) or level
2146 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2147 */
2148int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2149 irq_handler_t thread_fn, unsigned long irqflags,
2150 const char *devname, void *dev_id)
2151{
2152 struct irqaction *action;
2153 struct irq_desc *desc;
2154 int retval;
2155
2156 if (irq == IRQ_NOTCONNECTED)
2157 return -ENOTCONN;
2158
2159 /*
2160 * Sanity-check: shared interrupts must pass in a real dev-ID,
2161 * otherwise we'll have trouble later trying to figure out
2162 * which interrupt is which (messes up the interrupt freeing
2163 * logic etc).
2164 *
2165 * Also shared interrupts do not go well with disabling auto enable.
2166 * The sharing interrupt might request it while it's still disabled
2167 * and then wait for interrupts forever.
2168 *
2169 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2170 * it cannot be set along with IRQF_NO_SUSPEND.
2171 */
2172 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2173 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2174 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2175 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2176 return -EINVAL;
2177
2178 desc = irq_to_desc(irq);
2179 if (!desc)
2180 return -EINVAL;
2181
2182 if (!irq_settings_can_request(desc) ||
2183 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2184 return -EINVAL;
2185
2186 if (!handler) {
2187 if (!thread_fn)
2188 return -EINVAL;
2189 handler = irq_default_primary_handler;
2190 }
2191
2192 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2193 if (!action)
2194 return -ENOMEM;
2195
2196 action->handler = handler;
2197 action->thread_fn = thread_fn;
2198 action->flags = irqflags;
2199 action->name = devname;
2200 action->dev_id = dev_id;
2201
2202 retval = irq_chip_pm_get(&desc->irq_data);
2203 if (retval < 0) {
2204 kfree(action);
2205 return retval;
2206 }
2207
2208 retval = __setup_irq(irq, desc, action);
2209
2210 if (retval) {
2211 irq_chip_pm_put(&desc->irq_data);
2212 kfree(action->secondary);
2213 kfree(action);
2214 }
2215
2216#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2217 if (!retval && (irqflags & IRQF_SHARED)) {
2218 /*
2219 * It's a shared IRQ -- the driver ought to be prepared for it
2220 * to happen immediately, so let's make sure....
2221 * We disable the irq to make sure that a 'real' IRQ doesn't
2222 * run in parallel with our fake.
2223 */
2224 unsigned long flags;
2225
2226 disable_irq(irq);
2227 local_irq_save(flags);
2228
2229 handler(irq, dev_id);
2230
2231 local_irq_restore(flags);
2232 enable_irq(irq);
2233 }
2234#endif
2235 return retval;
2236}
2237EXPORT_SYMBOL(request_threaded_irq);
2238
2239/**
2240 * request_any_context_irq - allocate an interrupt line
2241 * @irq: Interrupt line to allocate
2242 * @handler: Function to be called when the IRQ occurs.
2243 * Threaded handler for threaded interrupts.
2244 * @flags: Interrupt type flags
2245 * @name: An ascii name for the claiming device
2246 * @dev_id: A cookie passed back to the handler function
2247 *
2248 * This call allocates interrupt resources and enables the
2249 * interrupt line and IRQ handling. It selects either a
2250 * hardirq or threaded handling method depending on the
2251 * context.
2252 *
2253 * On failure, it returns a negative value. On success,
2254 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2255 */
2256int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2257 unsigned long flags, const char *name, void *dev_id)
2258{
2259 struct irq_desc *desc;
2260 int ret;
2261
2262 if (irq == IRQ_NOTCONNECTED)
2263 return -ENOTCONN;
2264
2265 desc = irq_to_desc(irq);
2266 if (!desc)
2267 return -EINVAL;
2268
2269 if (irq_settings_is_nested_thread(desc)) {
2270 ret = request_threaded_irq(irq, NULL, handler,
2271 flags, name, dev_id);
2272 return !ret ? IRQC_IS_NESTED : ret;
2273 }
2274
2275 ret = request_irq(irq, handler, flags, name, dev_id);
2276 return !ret ? IRQC_IS_HARDIRQ : ret;
2277}
2278EXPORT_SYMBOL_GPL(request_any_context_irq);
2279
2280/**
2281 * request_nmi - allocate an interrupt line for NMI delivery
2282 * @irq: Interrupt line to allocate
2283 * @handler: Function to be called when the IRQ occurs.
2284 * Threaded handler for threaded interrupts.
2285 * @irqflags: Interrupt type flags
2286 * @name: An ascii name for the claiming device
2287 * @dev_id: A cookie passed back to the handler function
2288 *
2289 * This call allocates interrupt resources and enables the
2290 * interrupt line and IRQ handling. It sets up the IRQ line
2291 * to be handled as an NMI.
2292 *
2293 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2294 * cannot be threaded.
2295 *
2296 * Interrupt lines requested for NMI delivering must produce per cpu
2297 * interrupts and have auto enabling setting disabled.
2298 *
2299 * Dev_id must be globally unique. Normally the address of the
2300 * device data structure is used as the cookie. Since the handler
2301 * receives this value it makes sense to use it.
2302 *
2303 * If the interrupt line cannot be used to deliver NMIs, function
2304 * will fail and return a negative value.
2305 */
2306int request_nmi(unsigned int irq, irq_handler_t handler,
2307 unsigned long irqflags, const char *name, void *dev_id)
2308{
2309 struct irqaction *action;
2310 struct irq_desc *desc;
2311 unsigned long flags;
2312 int retval;
2313
2314 if (irq == IRQ_NOTCONNECTED)
2315 return -ENOTCONN;
2316
2317 /* NMI cannot be shared, used for Polling */
2318 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2319 return -EINVAL;
2320
2321 if (!(irqflags & IRQF_PERCPU))
2322 return -EINVAL;
2323
2324 if (!handler)
2325 return -EINVAL;
2326
2327 desc = irq_to_desc(irq);
2328
2329 if (!desc || (irq_settings_can_autoenable(desc) &&
2330 !(irqflags & IRQF_NO_AUTOEN)) ||
2331 !irq_settings_can_request(desc) ||
2332 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2333 !irq_supports_nmi(desc))
2334 return -EINVAL;
2335
2336 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2337 if (!action)
2338 return -ENOMEM;
2339
2340 action->handler = handler;
2341 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2342 action->name = name;
2343 action->dev_id = dev_id;
2344
2345 retval = irq_chip_pm_get(&desc->irq_data);
2346 if (retval < 0)
2347 goto err_out;
2348
2349 retval = __setup_irq(irq, desc, action);
2350 if (retval)
2351 goto err_irq_setup;
2352
2353 raw_spin_lock_irqsave(&desc->lock, flags);
2354
2355 /* Setup NMI state */
2356 desc->istate |= IRQS_NMI;
2357 retval = irq_nmi_setup(desc);
2358 if (retval) {
2359 __cleanup_nmi(irq, desc);
2360 raw_spin_unlock_irqrestore(&desc->lock, flags);
2361 return -EINVAL;
2362 }
2363
2364 raw_spin_unlock_irqrestore(&desc->lock, flags);
2365
2366 return 0;
2367
2368err_irq_setup:
2369 irq_chip_pm_put(&desc->irq_data);
2370err_out:
2371 kfree(action);
2372
2373 return retval;
2374}
2375
2376void enable_percpu_irq(unsigned int irq, unsigned int type)
2377{
2378 unsigned int cpu = smp_processor_id();
2379 unsigned long flags;
2380 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2381
2382 if (!desc)
2383 return;
2384
2385 /*
2386 * If the trigger type is not specified by the caller, then
2387 * use the default for this interrupt.
2388 */
2389 type &= IRQ_TYPE_SENSE_MASK;
2390 if (type == IRQ_TYPE_NONE)
2391 type = irqd_get_trigger_type(&desc->irq_data);
2392
2393 if (type != IRQ_TYPE_NONE) {
2394 int ret;
2395
2396 ret = __irq_set_trigger(desc, type);
2397
2398 if (ret) {
2399 WARN(1, "failed to set type for IRQ%d\n", irq);
2400 goto out;
2401 }
2402 }
2403
2404 irq_percpu_enable(desc, cpu);
2405out:
2406 irq_put_desc_unlock(desc, flags);
2407}
2408EXPORT_SYMBOL_GPL(enable_percpu_irq);
2409
2410void enable_percpu_nmi(unsigned int irq, unsigned int type)
2411{
2412 enable_percpu_irq(irq, type);
2413}
2414
2415/**
2416 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2417 * @irq: Linux irq number to check for
2418 *
2419 * Must be called from a non migratable context. Returns the enable
2420 * state of a per cpu interrupt on the current cpu.
2421 */
2422bool irq_percpu_is_enabled(unsigned int irq)
2423{
2424 unsigned int cpu = smp_processor_id();
2425 struct irq_desc *desc;
2426 unsigned long flags;
2427 bool is_enabled;
2428
2429 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2430 if (!desc)
2431 return false;
2432
2433 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2434 irq_put_desc_unlock(desc, flags);
2435
2436 return is_enabled;
2437}
2438EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2439
2440void disable_percpu_irq(unsigned int irq)
2441{
2442 unsigned int cpu = smp_processor_id();
2443 unsigned long flags;
2444 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2445
2446 if (!desc)
2447 return;
2448
2449 irq_percpu_disable(desc, cpu);
2450 irq_put_desc_unlock(desc, flags);
2451}
2452EXPORT_SYMBOL_GPL(disable_percpu_irq);
2453
2454void disable_percpu_nmi(unsigned int irq)
2455{
2456 disable_percpu_irq(irq);
2457}
2458
2459/*
2460 * Internal function to unregister a percpu irqaction.
2461 */
2462static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2463{
2464 struct irq_desc *desc = irq_to_desc(irq);
2465 struct irqaction *action;
2466 unsigned long flags;
2467
2468 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2469
2470 if (!desc)
2471 return NULL;
2472
2473 raw_spin_lock_irqsave(&desc->lock, flags);
2474
2475 action = desc->action;
2476 if (!action || action->percpu_dev_id != dev_id) {
2477 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2478 goto bad;
2479 }
2480
2481 if (!cpumask_empty(desc->percpu_enabled)) {
2482 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2483 irq, cpumask_first(desc->percpu_enabled));
2484 goto bad;
2485 }
2486
2487 /* Found it - now remove it from the list of entries: */
2488 desc->action = NULL;
2489
2490 desc->istate &= ~IRQS_NMI;
2491
2492 raw_spin_unlock_irqrestore(&desc->lock, flags);
2493
2494 unregister_handler_proc(irq, action);
2495
2496 irq_chip_pm_put(&desc->irq_data);
2497 module_put(desc->owner);
2498 return action;
2499
2500bad:
2501 raw_spin_unlock_irqrestore(&desc->lock, flags);
2502 return NULL;
2503}
2504
2505/**
2506 * remove_percpu_irq - free a per-cpu interrupt
2507 * @irq: Interrupt line to free
2508 * @act: irqaction for the interrupt
2509 *
2510 * Used to remove interrupts statically setup by the early boot process.
2511 */
2512void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2513{
2514 struct irq_desc *desc = irq_to_desc(irq);
2515
2516 if (desc && irq_settings_is_per_cpu_devid(desc))
2517 __free_percpu_irq(irq, act->percpu_dev_id);
2518}
2519
2520/**
2521 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2522 * @irq: Interrupt line to free
2523 * @dev_id: Device identity to free
2524 *
2525 * Remove a percpu interrupt handler. The handler is removed, but
2526 * the interrupt line is not disabled. This must be done on each
2527 * CPU before calling this function. The function does not return
2528 * until any executing interrupts for this IRQ have completed.
2529 *
2530 * This function must not be called from interrupt context.
2531 */
2532void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2533{
2534 struct irq_desc *desc = irq_to_desc(irq);
2535
2536 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2537 return;
2538
2539 chip_bus_lock(desc);
2540 kfree(__free_percpu_irq(irq, dev_id));
2541 chip_bus_sync_unlock(desc);
2542}
2543EXPORT_SYMBOL_GPL(free_percpu_irq);
2544
2545void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2546{
2547 struct irq_desc *desc = irq_to_desc(irq);
2548
2549 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2550 return;
2551
2552 if (WARN_ON(!irq_is_nmi(desc)))
2553 return;
2554
2555 kfree(__free_percpu_irq(irq, dev_id));
2556}
2557
2558/**
2559 * setup_percpu_irq - setup a per-cpu interrupt
2560 * @irq: Interrupt line to setup
2561 * @act: irqaction for the interrupt
2562 *
2563 * Used to statically setup per-cpu interrupts in the early boot process.
2564 */
2565int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2566{
2567 struct irq_desc *desc = irq_to_desc(irq);
2568 int retval;
2569
2570 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2571 return -EINVAL;
2572
2573 retval = irq_chip_pm_get(&desc->irq_data);
2574 if (retval < 0)
2575 return retval;
2576
2577 retval = __setup_irq(irq, desc, act);
2578
2579 if (retval)
2580 irq_chip_pm_put(&desc->irq_data);
2581
2582 return retval;
2583}
2584
2585/**
2586 * __request_percpu_irq - allocate a percpu interrupt line
2587 * @irq: Interrupt line to allocate
2588 * @handler: Function to be called when the IRQ occurs.
2589 * @flags: Interrupt type flags (IRQF_TIMER only)
2590 * @devname: An ascii name for the claiming device
2591 * @dev_id: A percpu cookie passed back to the handler function
2592 *
2593 * This call allocates interrupt resources and enables the
2594 * interrupt on the local CPU. If the interrupt is supposed to be
2595 * enabled on other CPUs, it has to be done on each CPU using
2596 * enable_percpu_irq().
2597 *
2598 * Dev_id must be globally unique. It is a per-cpu variable, and
2599 * the handler gets called with the interrupted CPU's instance of
2600 * that variable.
2601 */
2602int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2603 unsigned long flags, const char *devname,
2604 void __percpu *dev_id)
2605{
2606 struct irqaction *action;
2607 struct irq_desc *desc;
2608 int retval;
2609
2610 if (!dev_id)
2611 return -EINVAL;
2612
2613 desc = irq_to_desc(irq);
2614 if (!desc || !irq_settings_can_request(desc) ||
2615 !irq_settings_is_per_cpu_devid(desc))
2616 return -EINVAL;
2617
2618 if (flags && flags != IRQF_TIMER)
2619 return -EINVAL;
2620
2621 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2622 if (!action)
2623 return -ENOMEM;
2624
2625 action->handler = handler;
2626 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2627 action->name = devname;
2628 action->percpu_dev_id = dev_id;
2629
2630 retval = irq_chip_pm_get(&desc->irq_data);
2631 if (retval < 0) {
2632 kfree(action);
2633 return retval;
2634 }
2635
2636 retval = __setup_irq(irq, desc, action);
2637
2638 if (retval) {
2639 irq_chip_pm_put(&desc->irq_data);
2640 kfree(action);
2641 }
2642
2643 return retval;
2644}
2645EXPORT_SYMBOL_GPL(__request_percpu_irq);
2646
2647/**
2648 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2649 * @irq: Interrupt line to allocate
2650 * @handler: Function to be called when the IRQ occurs.
2651 * @name: An ascii name for the claiming device
2652 * @dev_id: A percpu cookie passed back to the handler function
2653 *
2654 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2655 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2656 * being enabled on the same CPU by using enable_percpu_nmi().
2657 *
2658 * Dev_id must be globally unique. It is a per-cpu variable, and
2659 * the handler gets called with the interrupted CPU's instance of
2660 * that variable.
2661 *
2662 * Interrupt lines requested for NMI delivering should have auto enabling
2663 * setting disabled.
2664 *
2665 * If the interrupt line cannot be used to deliver NMIs, function
2666 * will fail returning a negative value.
2667 */
2668int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2669 const char *name, void __percpu *dev_id)
2670{
2671 struct irqaction *action;
2672 struct irq_desc *desc;
2673 unsigned long flags;
2674 int retval;
2675
2676 if (!handler)
2677 return -EINVAL;
2678
2679 desc = irq_to_desc(irq);
2680
2681 if (!desc || !irq_settings_can_request(desc) ||
2682 !irq_settings_is_per_cpu_devid(desc) ||
2683 irq_settings_can_autoenable(desc) ||
2684 !irq_supports_nmi(desc))
2685 return -EINVAL;
2686
2687 /* The line cannot already be NMI */
2688 if (irq_is_nmi(desc))
2689 return -EINVAL;
2690
2691 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2692 if (!action)
2693 return -ENOMEM;
2694
2695 action->handler = handler;
2696 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2697 | IRQF_NOBALANCING;
2698 action->name = name;
2699 action->percpu_dev_id = dev_id;
2700
2701 retval = irq_chip_pm_get(&desc->irq_data);
2702 if (retval < 0)
2703 goto err_out;
2704
2705 retval = __setup_irq(irq, desc, action);
2706 if (retval)
2707 goto err_irq_setup;
2708
2709 raw_spin_lock_irqsave(&desc->lock, flags);
2710 desc->istate |= IRQS_NMI;
2711 raw_spin_unlock_irqrestore(&desc->lock, flags);
2712
2713 return 0;
2714
2715err_irq_setup:
2716 irq_chip_pm_put(&desc->irq_data);
2717err_out:
2718 kfree(action);
2719
2720 return retval;
2721}
2722
2723/**
2724 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2725 * @irq: Interrupt line to prepare for NMI delivery
2726 *
2727 * This call prepares an interrupt line to deliver NMI on the current CPU,
2728 * before that interrupt line gets enabled with enable_percpu_nmi().
2729 *
2730 * As a CPU local operation, this should be called from non-preemptible
2731 * context.
2732 *
2733 * If the interrupt line cannot be used to deliver NMIs, function
2734 * will fail returning a negative value.
2735 */
2736int prepare_percpu_nmi(unsigned int irq)
2737{
2738 unsigned long flags;
2739 struct irq_desc *desc;
2740 int ret = 0;
2741
2742 WARN_ON(preemptible());
2743
2744 desc = irq_get_desc_lock(irq, &flags,
2745 IRQ_GET_DESC_CHECK_PERCPU);
2746 if (!desc)
2747 return -EINVAL;
2748
2749 if (WARN(!irq_is_nmi(desc),
2750 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2751 irq)) {
2752 ret = -EINVAL;
2753 goto out;
2754 }
2755
2756 ret = irq_nmi_setup(desc);
2757 if (ret) {
2758 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2759 goto out;
2760 }
2761
2762out:
2763 irq_put_desc_unlock(desc, flags);
2764 return ret;
2765}
2766
2767/**
2768 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2769 * @irq: Interrupt line from which CPU local NMI configuration should be
2770 * removed
2771 *
2772 * This call undoes the setup done by prepare_percpu_nmi().
2773 *
2774 * IRQ line should not be enabled for the current CPU.
2775 *
2776 * As a CPU local operation, this should be called from non-preemptible
2777 * context.
2778 */
2779void teardown_percpu_nmi(unsigned int irq)
2780{
2781 unsigned long flags;
2782 struct irq_desc *desc;
2783
2784 WARN_ON(preemptible());
2785
2786 desc = irq_get_desc_lock(irq, &flags,
2787 IRQ_GET_DESC_CHECK_PERCPU);
2788 if (!desc)
2789 return;
2790
2791 if (WARN_ON(!irq_is_nmi(desc)))
2792 goto out;
2793
2794 irq_nmi_teardown(desc);
2795out:
2796 irq_put_desc_unlock(desc, flags);
2797}
2798
2799int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2800 bool *state)
2801{
2802 struct irq_chip *chip;
2803 int err = -EINVAL;
2804
2805 do {
2806 chip = irq_data_get_irq_chip(data);
2807 if (WARN_ON_ONCE(!chip))
2808 return -ENODEV;
2809 if (chip->irq_get_irqchip_state)
2810 break;
2811#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2812 data = data->parent_data;
2813#else
2814 data = NULL;
2815#endif
2816 } while (data);
2817
2818 if (data)
2819 err = chip->irq_get_irqchip_state(data, which, state);
2820 return err;
2821}
2822
2823/**
2824 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2825 * @irq: Interrupt line that is forwarded to a VM
2826 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2827 * @state: a pointer to a boolean where the state is to be stored
2828 *
2829 * This call snapshots the internal irqchip state of an
2830 * interrupt, returning into @state the bit corresponding to
2831 * stage @which
2832 *
2833 * This function should be called with preemption disabled if the
2834 * interrupt controller has per-cpu registers.
2835 */
2836int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2837 bool *state)
2838{
2839 struct irq_desc *desc;
2840 struct irq_data *data;
2841 unsigned long flags;
2842 int err = -EINVAL;
2843
2844 desc = irq_get_desc_buslock(irq, &flags, 0);
2845 if (!desc)
2846 return err;
2847
2848 data = irq_desc_get_irq_data(desc);
2849
2850 err = __irq_get_irqchip_state(data, which, state);
2851
2852 irq_put_desc_busunlock(desc, flags);
2853 return err;
2854}
2855EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2856
2857/**
2858 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2859 * @irq: Interrupt line that is forwarded to a VM
2860 * @which: State to be restored (one of IRQCHIP_STATE_*)
2861 * @val: Value corresponding to @which
2862 *
2863 * This call sets the internal irqchip state of an interrupt,
2864 * depending on the value of @which.
2865 *
2866 * This function should be called with migration disabled if the
2867 * interrupt controller has per-cpu registers.
2868 */
2869int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2870 bool val)
2871{
2872 struct irq_desc *desc;
2873 struct irq_data *data;
2874 struct irq_chip *chip;
2875 unsigned long flags;
2876 int err = -EINVAL;
2877
2878 desc = irq_get_desc_buslock(irq, &flags, 0);
2879 if (!desc)
2880 return err;
2881
2882 data = irq_desc_get_irq_data(desc);
2883
2884 do {
2885 chip = irq_data_get_irq_chip(data);
2886 if (WARN_ON_ONCE(!chip)) {
2887 err = -ENODEV;
2888 goto out_unlock;
2889 }
2890 if (chip->irq_set_irqchip_state)
2891 break;
2892#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2893 data = data->parent_data;
2894#else
2895 data = NULL;
2896#endif
2897 } while (data);
2898
2899 if (data)
2900 err = chip->irq_set_irqchip_state(data, which, val);
2901
2902out_unlock:
2903 irq_put_desc_busunlock(desc, flags);
2904 return err;
2905}
2906EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2907
2908/**
2909 * irq_has_action - Check whether an interrupt is requested
2910 * @irq: The linux irq number
2911 *
2912 * Returns: A snapshot of the current state
2913 */
2914bool irq_has_action(unsigned int irq)
2915{
2916 bool res;
2917
2918 rcu_read_lock();
2919 res = irq_desc_has_action(irq_to_desc(irq));
2920 rcu_read_unlock();
2921 return res;
2922}
2923EXPORT_SYMBOL_GPL(irq_has_action);
2924
2925/**
2926 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2927 * @irq: The linux irq number
2928 * @bitmask: The bitmask to evaluate
2929 *
2930 * Returns: True if one of the bits in @bitmask is set
2931 */
2932bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2933{
2934 struct irq_desc *desc;
2935 bool res = false;
2936
2937 rcu_read_lock();
2938 desc = irq_to_desc(irq);
2939 if (desc)
2940 res = !!(desc->status_use_accessors & bitmask);
2941 rcu_read_unlock();
2942 return res;
2943}
2944EXPORT_SYMBOL_GPL(irq_check_status_bit);