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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 * Returns: false if a threaded handler is active.
72 *
73 * This function may be called - with care - from IRQ context.
74 */
75bool synchronize_hardirq(unsigned int irq)
76{
77 struct irq_desc *desc = irq_to_desc(irq);
78
79 if (desc) {
80 __synchronize_hardirq(desc);
81 return !atomic_read(&desc->threads_active);
82 }
83
84 return true;
85}
86EXPORT_SYMBOL(synchronize_hardirq);
87
88/**
89 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
90 * @irq: interrupt number to wait for
91 *
92 * This function waits for any pending IRQ handlers for this interrupt
93 * to complete before returning. If you use this function while
94 * holding a resource the IRQ handler may need you will deadlock.
95 *
96 * This function may be called - with care - from IRQ context.
97 */
98void synchronize_irq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc);
104 /*
105 * We made sure that no hardirq handler is
106 * running. Now verify that no threaded handlers are
107 * active.
108 */
109 wait_event(desc->wait_for_threads,
110 !atomic_read(&desc->threads_active));
111 }
112}
113EXPORT_SYMBOL(synchronize_irq);
114
115#ifdef CONFIG_SMP
116cpumask_var_t irq_default_affinity;
117
118static int __irq_can_set_affinity(struct irq_desc *desc)
119{
120 if (!desc || !irqd_can_balance(&desc->irq_data) ||
121 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
122 return 0;
123 return 1;
124}
125
126/**
127 * irq_can_set_affinity - Check if the affinity of a given irq can be set
128 * @irq: Interrupt to check
129 *
130 */
131int irq_can_set_affinity(unsigned int irq)
132{
133 return __irq_can_set_affinity(irq_to_desc(irq));
134}
135
136/**
137 * irq_set_thread_affinity - Notify irq threads to adjust affinity
138 * @desc: irq descriptor which has affitnity changed
139 *
140 * We just set IRQTF_AFFINITY and delegate the affinity setting
141 * to the interrupt thread itself. We can not call
142 * set_cpus_allowed_ptr() here as we hold desc->lock and this
143 * code can be called from hard interrupt context.
144 */
145void irq_set_thread_affinity(struct irq_desc *desc)
146{
147 struct irqaction *action;
148
149 for_each_action_of_desc(desc, action)
150 if (action->thread)
151 set_bit(IRQTF_AFFINITY, &action->thread_flags);
152}
153
154#ifdef CONFIG_GENERIC_PENDING_IRQ
155static inline bool irq_can_move_pcntxt(struct irq_data *data)
156{
157 return irqd_can_move_in_process_context(data);
158}
159static inline bool irq_move_pending(struct irq_data *data)
160{
161 return irqd_is_setaffinity_pending(data);
162}
163static inline void
164irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
165{
166 cpumask_copy(desc->pending_mask, mask);
167}
168static inline void
169irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
170{
171 cpumask_copy(mask, desc->pending_mask);
172}
173#else
174static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
175static inline bool irq_move_pending(struct irq_data *data) { return false; }
176static inline void
177irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
178static inline void
179irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
180#endif
181
182int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
183 bool force)
184{
185 struct irq_desc *desc = irq_data_to_desc(data);
186 struct irq_chip *chip = irq_data_get_irq_chip(data);
187 int ret;
188
189 ret = chip->irq_set_affinity(data, mask, force);
190 switch (ret) {
191 case IRQ_SET_MASK_OK:
192 case IRQ_SET_MASK_OK_DONE:
193 cpumask_copy(desc->irq_common_data.affinity, mask);
194 case IRQ_SET_MASK_OK_NOCOPY:
195 irq_set_thread_affinity(desc);
196 ret = 0;
197 }
198
199 return ret;
200}
201
202int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
203 bool force)
204{
205 struct irq_chip *chip = irq_data_get_irq_chip(data);
206 struct irq_desc *desc = irq_data_to_desc(data);
207 int ret = 0;
208
209 if (!chip || !chip->irq_set_affinity)
210 return -EINVAL;
211
212 if (irq_can_move_pcntxt(data)) {
213 ret = irq_do_set_affinity(data, mask, force);
214 } else {
215 irqd_set_move_pending(data);
216 irq_copy_pending(desc, mask);
217 }
218
219 if (desc->affinity_notify) {
220 kref_get(&desc->affinity_notify->kref);
221 schedule_work(&desc->affinity_notify->work);
222 }
223 irqd_set(data, IRQD_AFFINITY_SET);
224
225 return ret;
226}
227
228int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
229{
230 struct irq_desc *desc = irq_to_desc(irq);
231 unsigned long flags;
232 int ret;
233
234 if (!desc)
235 return -EINVAL;
236
237 raw_spin_lock_irqsave(&desc->lock, flags);
238 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
239 raw_spin_unlock_irqrestore(&desc->lock, flags);
240 return ret;
241}
242
243int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
244{
245 unsigned long flags;
246 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
247
248 if (!desc)
249 return -EINVAL;
250 desc->affinity_hint = m;
251 irq_put_desc_unlock(desc, flags);
252 /* set the initial affinity to prevent every interrupt being on CPU0 */
253 if (m)
254 __irq_set_affinity(irq, m, false);
255 return 0;
256}
257EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
258
259static void irq_affinity_notify(struct work_struct *work)
260{
261 struct irq_affinity_notify *notify =
262 container_of(work, struct irq_affinity_notify, work);
263 struct irq_desc *desc = irq_to_desc(notify->irq);
264 cpumask_var_t cpumask;
265 unsigned long flags;
266
267 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
268 goto out;
269
270 raw_spin_lock_irqsave(&desc->lock, flags);
271 if (irq_move_pending(&desc->irq_data))
272 irq_get_pending(cpumask, desc);
273 else
274 cpumask_copy(cpumask, desc->irq_common_data.affinity);
275 raw_spin_unlock_irqrestore(&desc->lock, flags);
276
277 notify->notify(notify, cpumask);
278
279 free_cpumask_var(cpumask);
280out:
281 kref_put(¬ify->kref, notify->release);
282}
283
284/**
285 * irq_set_affinity_notifier - control notification of IRQ affinity changes
286 * @irq: Interrupt for which to enable/disable notification
287 * @notify: Context for notification, or %NULL to disable
288 * notification. Function pointers must be initialised;
289 * the other fields will be initialised by this function.
290 *
291 * Must be called in process context. Notification may only be enabled
292 * after the IRQ is allocated and must be disabled before the IRQ is
293 * freed using free_irq().
294 */
295int
296irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
297{
298 struct irq_desc *desc = irq_to_desc(irq);
299 struct irq_affinity_notify *old_notify;
300 unsigned long flags;
301
302 /* The release function is promised process context */
303 might_sleep();
304
305 if (!desc)
306 return -EINVAL;
307
308 /* Complete initialisation of *notify */
309 if (notify) {
310 notify->irq = irq;
311 kref_init(¬ify->kref);
312 INIT_WORK(¬ify->work, irq_affinity_notify);
313 }
314
315 raw_spin_lock_irqsave(&desc->lock, flags);
316 old_notify = desc->affinity_notify;
317 desc->affinity_notify = notify;
318 raw_spin_unlock_irqrestore(&desc->lock, flags);
319
320 if (old_notify)
321 kref_put(&old_notify->kref, old_notify->release);
322
323 return 0;
324}
325EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
326
327#ifndef CONFIG_AUTO_IRQ_AFFINITY
328/*
329 * Generic version of the affinity autoselector.
330 */
331static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
332{
333 struct cpumask *set = irq_default_affinity;
334 int node = irq_desc_get_node(desc);
335
336 /* Excludes PER_CPU and NO_BALANCE interrupts */
337 if (!__irq_can_set_affinity(desc))
338 return 0;
339
340 /*
341 * Preserve an userspace affinity setup, but make sure that
342 * one of the targets is online.
343 */
344 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
345 if (cpumask_intersects(desc->irq_common_data.affinity,
346 cpu_online_mask))
347 set = desc->irq_common_data.affinity;
348 else
349 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
350 }
351
352 cpumask_and(mask, cpu_online_mask, set);
353 if (node != NUMA_NO_NODE) {
354 const struct cpumask *nodemask = cpumask_of_node(node);
355
356 /* make sure at least one of the cpus in nodemask is online */
357 if (cpumask_intersects(mask, nodemask))
358 cpumask_and(mask, mask, nodemask);
359 }
360 irq_do_set_affinity(&desc->irq_data, mask, false);
361 return 0;
362}
363#else
364/* Wrapper for ALPHA specific affinity selector magic */
365static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
366{
367 return irq_select_affinity(irq_desc_get_irq(d));
368}
369#endif
370
371/*
372 * Called when affinity is set via /proc/irq
373 */
374int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
375{
376 struct irq_desc *desc = irq_to_desc(irq);
377 unsigned long flags;
378 int ret;
379
380 raw_spin_lock_irqsave(&desc->lock, flags);
381 ret = setup_affinity(desc, mask);
382 raw_spin_unlock_irqrestore(&desc->lock, flags);
383 return ret;
384}
385
386#else
387static inline int
388setup_affinity(struct irq_desc *desc, struct cpumask *mask)
389{
390 return 0;
391}
392#endif
393
394/**
395 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
396 * @irq: interrupt number to set affinity
397 * @vcpu_info: vCPU specific data
398 *
399 * This function uses the vCPU specific data to set the vCPU
400 * affinity for an irq. The vCPU specific data is passed from
401 * outside, such as KVM. One example code path is as below:
402 * KVM -> IOMMU -> irq_set_vcpu_affinity().
403 */
404int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
405{
406 unsigned long flags;
407 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
408 struct irq_data *data;
409 struct irq_chip *chip;
410 int ret = -ENOSYS;
411
412 if (!desc)
413 return -EINVAL;
414
415 data = irq_desc_get_irq_data(desc);
416 chip = irq_data_get_irq_chip(data);
417 if (chip && chip->irq_set_vcpu_affinity)
418 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
419 irq_put_desc_unlock(desc, flags);
420
421 return ret;
422}
423EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
424
425void __disable_irq(struct irq_desc *desc)
426{
427 if (!desc->depth++)
428 irq_disable(desc);
429}
430
431static int __disable_irq_nosync(unsigned int irq)
432{
433 unsigned long flags;
434 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
435
436 if (!desc)
437 return -EINVAL;
438 __disable_irq(desc);
439 irq_put_desc_busunlock(desc, flags);
440 return 0;
441}
442
443/**
444 * disable_irq_nosync - disable an irq without waiting
445 * @irq: Interrupt to disable
446 *
447 * Disable the selected interrupt line. Disables and Enables are
448 * nested.
449 * Unlike disable_irq(), this function does not ensure existing
450 * instances of the IRQ handler have completed before returning.
451 *
452 * This function may be called from IRQ context.
453 */
454void disable_irq_nosync(unsigned int irq)
455{
456 __disable_irq_nosync(irq);
457}
458EXPORT_SYMBOL(disable_irq_nosync);
459
460/**
461 * disable_irq - disable an irq and wait for completion
462 * @irq: Interrupt to disable
463 *
464 * Disable the selected interrupt line. Enables and Disables are
465 * nested.
466 * This function waits for any pending IRQ handlers for this interrupt
467 * to complete before returning. If you use this function while
468 * holding a resource the IRQ handler may need you will deadlock.
469 *
470 * This function may be called - with care - from IRQ context.
471 */
472void disable_irq(unsigned int irq)
473{
474 if (!__disable_irq_nosync(irq))
475 synchronize_irq(irq);
476}
477EXPORT_SYMBOL(disable_irq);
478
479/**
480 * disable_hardirq - disables an irq and waits for hardirq completion
481 * @irq: Interrupt to disable
482 *
483 * Disable the selected interrupt line. Enables and Disables are
484 * nested.
485 * This function waits for any pending hard IRQ handlers for this
486 * interrupt to complete before returning. If you use this function while
487 * holding a resource the hard IRQ handler may need you will deadlock.
488 *
489 * When used to optimistically disable an interrupt from atomic context
490 * the return value must be checked.
491 *
492 * Returns: false if a threaded handler is active.
493 *
494 * This function may be called - with care - from IRQ context.
495 */
496bool disable_hardirq(unsigned int irq)
497{
498 if (!__disable_irq_nosync(irq))
499 return synchronize_hardirq(irq);
500
501 return false;
502}
503EXPORT_SYMBOL_GPL(disable_hardirq);
504
505void __enable_irq(struct irq_desc *desc)
506{
507 switch (desc->depth) {
508 case 0:
509 err_out:
510 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
511 irq_desc_get_irq(desc));
512 break;
513 case 1: {
514 if (desc->istate & IRQS_SUSPENDED)
515 goto err_out;
516 /* Prevent probing on this irq: */
517 irq_settings_set_noprobe(desc);
518 irq_enable(desc);
519 check_irq_resend(desc);
520 /* fall-through */
521 }
522 default:
523 desc->depth--;
524 }
525}
526
527/**
528 * enable_irq - enable handling of an irq
529 * @irq: Interrupt to enable
530 *
531 * Undoes the effect of one call to disable_irq(). If this
532 * matches the last disable, processing of interrupts on this
533 * IRQ line is re-enabled.
534 *
535 * This function may be called from IRQ context only when
536 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
537 */
538void enable_irq(unsigned int irq)
539{
540 unsigned long flags;
541 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
542
543 if (!desc)
544 return;
545 if (WARN(!desc->irq_data.chip,
546 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
547 goto out;
548
549 __enable_irq(desc);
550out:
551 irq_put_desc_busunlock(desc, flags);
552}
553EXPORT_SYMBOL(enable_irq);
554
555static int set_irq_wake_real(unsigned int irq, unsigned int on)
556{
557 struct irq_desc *desc = irq_to_desc(irq);
558 int ret = -ENXIO;
559
560 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
561 return 0;
562
563 if (desc->irq_data.chip->irq_set_wake)
564 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
565
566 return ret;
567}
568
569/**
570 * irq_set_irq_wake - control irq power management wakeup
571 * @irq: interrupt to control
572 * @on: enable/disable power management wakeup
573 *
574 * Enable/disable power management wakeup mode, which is
575 * disabled by default. Enables and disables must match,
576 * just as they match for non-wakeup mode support.
577 *
578 * Wakeup mode lets this IRQ wake the system from sleep
579 * states like "suspend to RAM".
580 */
581int irq_set_irq_wake(unsigned int irq, unsigned int on)
582{
583 unsigned long flags;
584 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
585 int ret = 0;
586
587 if (!desc)
588 return -EINVAL;
589
590 /* wakeup-capable irqs can be shared between drivers that
591 * don't need to have the same sleep mode behaviors.
592 */
593 if (on) {
594 if (desc->wake_depth++ == 0) {
595 ret = set_irq_wake_real(irq, on);
596 if (ret)
597 desc->wake_depth = 0;
598 else
599 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
600 }
601 } else {
602 if (desc->wake_depth == 0) {
603 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
604 } else if (--desc->wake_depth == 0) {
605 ret = set_irq_wake_real(irq, on);
606 if (ret)
607 desc->wake_depth = 1;
608 else
609 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
610 }
611 }
612 irq_put_desc_busunlock(desc, flags);
613 return ret;
614}
615EXPORT_SYMBOL(irq_set_irq_wake);
616
617/*
618 * Internal function that tells the architecture code whether a
619 * particular irq has been exclusively allocated or is available
620 * for driver use.
621 */
622int can_request_irq(unsigned int irq, unsigned long irqflags)
623{
624 unsigned long flags;
625 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
626 int canrequest = 0;
627
628 if (!desc)
629 return 0;
630
631 if (irq_settings_can_request(desc)) {
632 if (!desc->action ||
633 irqflags & desc->action->flags & IRQF_SHARED)
634 canrequest = 1;
635 }
636 irq_put_desc_unlock(desc, flags);
637 return canrequest;
638}
639
640int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
641{
642 struct irq_chip *chip = desc->irq_data.chip;
643 int ret, unmask = 0;
644
645 if (!chip || !chip->irq_set_type) {
646 /*
647 * IRQF_TRIGGER_* but the PIC does not support multiple
648 * flow-types?
649 */
650 pr_debug("No set_type function for IRQ %d (%s)\n",
651 irq_desc_get_irq(desc),
652 chip ? (chip->name ? : "unknown") : "unknown");
653 return 0;
654 }
655
656 flags &= IRQ_TYPE_SENSE_MASK;
657
658 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
659 if (!irqd_irq_masked(&desc->irq_data))
660 mask_irq(desc);
661 if (!irqd_irq_disabled(&desc->irq_data))
662 unmask = 1;
663 }
664
665 /* caller masked out all except trigger mode flags */
666 ret = chip->irq_set_type(&desc->irq_data, flags);
667
668 switch (ret) {
669 case IRQ_SET_MASK_OK:
670 case IRQ_SET_MASK_OK_DONE:
671 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
672 irqd_set(&desc->irq_data, flags);
673
674 case IRQ_SET_MASK_OK_NOCOPY:
675 flags = irqd_get_trigger_type(&desc->irq_data);
676 irq_settings_set_trigger_mask(desc, flags);
677 irqd_clear(&desc->irq_data, IRQD_LEVEL);
678 irq_settings_clr_level(desc);
679 if (flags & IRQ_TYPE_LEVEL_MASK) {
680 irq_settings_set_level(desc);
681 irqd_set(&desc->irq_data, IRQD_LEVEL);
682 }
683
684 ret = 0;
685 break;
686 default:
687 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
688 flags, irq_desc_get_irq(desc), chip->irq_set_type);
689 }
690 if (unmask)
691 unmask_irq(desc);
692 return ret;
693}
694
695#ifdef CONFIG_HARDIRQS_SW_RESEND
696int irq_set_parent(int irq, int parent_irq)
697{
698 unsigned long flags;
699 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
700
701 if (!desc)
702 return -EINVAL;
703
704 desc->parent_irq = parent_irq;
705
706 irq_put_desc_unlock(desc, flags);
707 return 0;
708}
709#endif
710
711/*
712 * Default primary interrupt handler for threaded interrupts. Is
713 * assigned as primary handler when request_threaded_irq is called
714 * with handler == NULL. Useful for oneshot interrupts.
715 */
716static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
717{
718 return IRQ_WAKE_THREAD;
719}
720
721/*
722 * Primary handler for nested threaded interrupts. Should never be
723 * called.
724 */
725static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
726{
727 WARN(1, "Primary handler called for nested irq %d\n", irq);
728 return IRQ_NONE;
729}
730
731static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
732{
733 WARN(1, "Secondary action handler called for irq %d\n", irq);
734 return IRQ_NONE;
735}
736
737static int irq_wait_for_interrupt(struct irqaction *action)
738{
739 set_current_state(TASK_INTERRUPTIBLE);
740
741 while (!kthread_should_stop()) {
742
743 if (test_and_clear_bit(IRQTF_RUNTHREAD,
744 &action->thread_flags)) {
745 __set_current_state(TASK_RUNNING);
746 return 0;
747 }
748 schedule();
749 set_current_state(TASK_INTERRUPTIBLE);
750 }
751 __set_current_state(TASK_RUNNING);
752 return -1;
753}
754
755/*
756 * Oneshot interrupts keep the irq line masked until the threaded
757 * handler finished. unmask if the interrupt has not been disabled and
758 * is marked MASKED.
759 */
760static void irq_finalize_oneshot(struct irq_desc *desc,
761 struct irqaction *action)
762{
763 if (!(desc->istate & IRQS_ONESHOT) ||
764 action->handler == irq_forced_secondary_handler)
765 return;
766again:
767 chip_bus_lock(desc);
768 raw_spin_lock_irq(&desc->lock);
769
770 /*
771 * Implausible though it may be we need to protect us against
772 * the following scenario:
773 *
774 * The thread is faster done than the hard interrupt handler
775 * on the other CPU. If we unmask the irq line then the
776 * interrupt can come in again and masks the line, leaves due
777 * to IRQS_INPROGRESS and the irq line is masked forever.
778 *
779 * This also serializes the state of shared oneshot handlers
780 * versus "desc->threads_onehsot |= action->thread_mask;" in
781 * irq_wake_thread(). See the comment there which explains the
782 * serialization.
783 */
784 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
785 raw_spin_unlock_irq(&desc->lock);
786 chip_bus_sync_unlock(desc);
787 cpu_relax();
788 goto again;
789 }
790
791 /*
792 * Now check again, whether the thread should run. Otherwise
793 * we would clear the threads_oneshot bit of this thread which
794 * was just set.
795 */
796 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
797 goto out_unlock;
798
799 desc->threads_oneshot &= ~action->thread_mask;
800
801 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
802 irqd_irq_masked(&desc->irq_data))
803 unmask_threaded_irq(desc);
804
805out_unlock:
806 raw_spin_unlock_irq(&desc->lock);
807 chip_bus_sync_unlock(desc);
808}
809
810#ifdef CONFIG_SMP
811/*
812 * Check whether we need to change the affinity of the interrupt thread.
813 */
814static void
815irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
816{
817 cpumask_var_t mask;
818 bool valid = true;
819
820 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
821 return;
822
823 /*
824 * In case we are out of memory we set IRQTF_AFFINITY again and
825 * try again next time
826 */
827 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
828 set_bit(IRQTF_AFFINITY, &action->thread_flags);
829 return;
830 }
831
832 raw_spin_lock_irq(&desc->lock);
833 /*
834 * This code is triggered unconditionally. Check the affinity
835 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
836 */
837 if (desc->irq_common_data.affinity)
838 cpumask_copy(mask, desc->irq_common_data.affinity);
839 else
840 valid = false;
841 raw_spin_unlock_irq(&desc->lock);
842
843 if (valid)
844 set_cpus_allowed_ptr(current, mask);
845 free_cpumask_var(mask);
846}
847#else
848static inline void
849irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
850#endif
851
852/*
853 * Interrupts which are not explicitely requested as threaded
854 * interrupts rely on the implicit bh/preempt disable of the hard irq
855 * context. So we need to disable bh here to avoid deadlocks and other
856 * side effects.
857 */
858static irqreturn_t
859irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
860{
861 irqreturn_t ret;
862
863 local_bh_disable();
864 ret = action->thread_fn(action->irq, action->dev_id);
865 irq_finalize_oneshot(desc, action);
866 local_bh_enable();
867 return ret;
868}
869
870/*
871 * Interrupts explicitly requested as threaded interrupts want to be
872 * preemtible - many of them need to sleep and wait for slow busses to
873 * complete.
874 */
875static irqreturn_t irq_thread_fn(struct irq_desc *desc,
876 struct irqaction *action)
877{
878 irqreturn_t ret;
879
880 ret = action->thread_fn(action->irq, action->dev_id);
881 irq_finalize_oneshot(desc, action);
882 return ret;
883}
884
885static void wake_threads_waitq(struct irq_desc *desc)
886{
887 if (atomic_dec_and_test(&desc->threads_active))
888 wake_up(&desc->wait_for_threads);
889}
890
891static void irq_thread_dtor(struct callback_head *unused)
892{
893 struct task_struct *tsk = current;
894 struct irq_desc *desc;
895 struct irqaction *action;
896
897 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
898 return;
899
900 action = kthread_data(tsk);
901
902 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
903 tsk->comm, tsk->pid, action->irq);
904
905
906 desc = irq_to_desc(action->irq);
907 /*
908 * If IRQTF_RUNTHREAD is set, we need to decrement
909 * desc->threads_active and wake possible waiters.
910 */
911 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
912 wake_threads_waitq(desc);
913
914 /* Prevent a stale desc->threads_oneshot */
915 irq_finalize_oneshot(desc, action);
916}
917
918static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
919{
920 struct irqaction *secondary = action->secondary;
921
922 if (WARN_ON_ONCE(!secondary))
923 return;
924
925 raw_spin_lock_irq(&desc->lock);
926 __irq_wake_thread(desc, secondary);
927 raw_spin_unlock_irq(&desc->lock);
928}
929
930/*
931 * Interrupt handler thread
932 */
933static int irq_thread(void *data)
934{
935 struct callback_head on_exit_work;
936 struct irqaction *action = data;
937 struct irq_desc *desc = irq_to_desc(action->irq);
938 irqreturn_t (*handler_fn)(struct irq_desc *desc,
939 struct irqaction *action);
940
941 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
942 &action->thread_flags))
943 handler_fn = irq_forced_thread_fn;
944 else
945 handler_fn = irq_thread_fn;
946
947 init_task_work(&on_exit_work, irq_thread_dtor);
948 task_work_add(current, &on_exit_work, false);
949
950 irq_thread_check_affinity(desc, action);
951
952 while (!irq_wait_for_interrupt(action)) {
953 irqreturn_t action_ret;
954
955 irq_thread_check_affinity(desc, action);
956
957 action_ret = handler_fn(desc, action);
958 if (action_ret == IRQ_HANDLED)
959 atomic_inc(&desc->threads_handled);
960 if (action_ret == IRQ_WAKE_THREAD)
961 irq_wake_secondary(desc, action);
962
963 wake_threads_waitq(desc);
964 }
965
966 /*
967 * This is the regular exit path. __free_irq() is stopping the
968 * thread via kthread_stop() after calling
969 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
970 * oneshot mask bit can be set. We cannot verify that as we
971 * cannot touch the oneshot mask at this point anymore as
972 * __setup_irq() might have given out currents thread_mask
973 * again.
974 */
975 task_work_cancel(current, irq_thread_dtor);
976 return 0;
977}
978
979/**
980 * irq_wake_thread - wake the irq thread for the action identified by dev_id
981 * @irq: Interrupt line
982 * @dev_id: Device identity for which the thread should be woken
983 *
984 */
985void irq_wake_thread(unsigned int irq, void *dev_id)
986{
987 struct irq_desc *desc = irq_to_desc(irq);
988 struct irqaction *action;
989 unsigned long flags;
990
991 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
992 return;
993
994 raw_spin_lock_irqsave(&desc->lock, flags);
995 for_each_action_of_desc(desc, action) {
996 if (action->dev_id == dev_id) {
997 if (action->thread)
998 __irq_wake_thread(desc, action);
999 break;
1000 }
1001 }
1002 raw_spin_unlock_irqrestore(&desc->lock, flags);
1003}
1004EXPORT_SYMBOL_GPL(irq_wake_thread);
1005
1006static int irq_setup_forced_threading(struct irqaction *new)
1007{
1008 if (!force_irqthreads)
1009 return 0;
1010 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1011 return 0;
1012
1013 new->flags |= IRQF_ONESHOT;
1014
1015 /*
1016 * Handle the case where we have a real primary handler and a
1017 * thread handler. We force thread them as well by creating a
1018 * secondary action.
1019 */
1020 if (new->handler != irq_default_primary_handler && new->thread_fn) {
1021 /* Allocate the secondary action */
1022 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1023 if (!new->secondary)
1024 return -ENOMEM;
1025 new->secondary->handler = irq_forced_secondary_handler;
1026 new->secondary->thread_fn = new->thread_fn;
1027 new->secondary->dev_id = new->dev_id;
1028 new->secondary->irq = new->irq;
1029 new->secondary->name = new->name;
1030 }
1031 /* Deal with the primary handler */
1032 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1033 new->thread_fn = new->handler;
1034 new->handler = irq_default_primary_handler;
1035 return 0;
1036}
1037
1038static int irq_request_resources(struct irq_desc *desc)
1039{
1040 struct irq_data *d = &desc->irq_data;
1041 struct irq_chip *c = d->chip;
1042
1043 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1044}
1045
1046static void irq_release_resources(struct irq_desc *desc)
1047{
1048 struct irq_data *d = &desc->irq_data;
1049 struct irq_chip *c = d->chip;
1050
1051 if (c->irq_release_resources)
1052 c->irq_release_resources(d);
1053}
1054
1055static int
1056setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1057{
1058 struct task_struct *t;
1059 struct sched_param param = {
1060 .sched_priority = MAX_USER_RT_PRIO/2,
1061 };
1062
1063 if (!secondary) {
1064 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1065 new->name);
1066 } else {
1067 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1068 new->name);
1069 param.sched_priority -= 1;
1070 }
1071
1072 if (IS_ERR(t))
1073 return PTR_ERR(t);
1074
1075 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m);
1076
1077 /*
1078 * We keep the reference to the task struct even if
1079 * the thread dies to avoid that the interrupt code
1080 * references an already freed task_struct.
1081 */
1082 get_task_struct(t);
1083 new->thread = t;
1084 /*
1085 * Tell the thread to set its affinity. This is
1086 * important for shared interrupt handlers as we do
1087 * not invoke setup_affinity() for the secondary
1088 * handlers as everything is already set up. Even for
1089 * interrupts marked with IRQF_NO_BALANCE this is
1090 * correct as we want the thread to move to the cpu(s)
1091 * on which the requesting code placed the interrupt.
1092 */
1093 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1094 return 0;
1095}
1096
1097/*
1098 * Internal function to register an irqaction - typically used to
1099 * allocate special interrupts that are part of the architecture.
1100 */
1101static int
1102__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1103{
1104 struct irqaction *old, **old_ptr;
1105 unsigned long flags, thread_mask = 0;
1106 int ret, nested, shared = 0;
1107 cpumask_var_t mask;
1108
1109 if (!desc)
1110 return -EINVAL;
1111
1112 if (desc->irq_data.chip == &no_irq_chip)
1113 return -ENOSYS;
1114 if (!try_module_get(desc->owner))
1115 return -ENODEV;
1116
1117 new->irq = irq;
1118
1119 /*
1120 * Check whether the interrupt nests into another interrupt
1121 * thread.
1122 */
1123 nested = irq_settings_is_nested_thread(desc);
1124 if (nested) {
1125 if (!new->thread_fn) {
1126 ret = -EINVAL;
1127 goto out_mput;
1128 }
1129 /*
1130 * Replace the primary handler which was provided from
1131 * the driver for non nested interrupt handling by the
1132 * dummy function which warns when called.
1133 */
1134 new->handler = irq_nested_primary_handler;
1135 } else {
1136 if (irq_settings_can_thread(desc)) {
1137 ret = irq_setup_forced_threading(new);
1138 if (ret)
1139 goto out_mput;
1140 }
1141 }
1142
1143 /*
1144 * Create a handler thread when a thread function is supplied
1145 * and the interrupt does not nest into another interrupt
1146 * thread.
1147 */
1148 if (new->thread_fn && !nested) {
1149 ret = setup_irq_thread(new, irq, false);
1150 if (ret)
1151 goto out_mput;
1152 if (new->secondary) {
1153 ret = setup_irq_thread(new->secondary, irq, true);
1154 if (ret)
1155 goto out_thread;
1156 }
1157 }
1158
1159 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1160 ret = -ENOMEM;
1161 goto out_thread;
1162 }
1163
1164 /*
1165 * Drivers are often written to work w/o knowledge about the
1166 * underlying irq chip implementation, so a request for a
1167 * threaded irq without a primary hard irq context handler
1168 * requires the ONESHOT flag to be set. Some irq chips like
1169 * MSI based interrupts are per se one shot safe. Check the
1170 * chip flags, so we can avoid the unmask dance at the end of
1171 * the threaded handler for those.
1172 */
1173 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1174 new->flags &= ~IRQF_ONESHOT;
1175
1176 /*
1177 * The following block of code has to be executed atomically
1178 */
1179 raw_spin_lock_irqsave(&desc->lock, flags);
1180 old_ptr = &desc->action;
1181 old = *old_ptr;
1182 if (old) {
1183 /*
1184 * Can't share interrupts unless both agree to and are
1185 * the same type (level, edge, polarity). So both flag
1186 * fields must have IRQF_SHARED set and the bits which
1187 * set the trigger type must match. Also all must
1188 * agree on ONESHOT.
1189 */
1190 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1191 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1192 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1193 goto mismatch;
1194
1195 /* All handlers must agree on per-cpuness */
1196 if ((old->flags & IRQF_PERCPU) !=
1197 (new->flags & IRQF_PERCPU))
1198 goto mismatch;
1199
1200 /* add new interrupt at end of irq queue */
1201 do {
1202 /*
1203 * Or all existing action->thread_mask bits,
1204 * so we can find the next zero bit for this
1205 * new action.
1206 */
1207 thread_mask |= old->thread_mask;
1208 old_ptr = &old->next;
1209 old = *old_ptr;
1210 } while (old);
1211 shared = 1;
1212 }
1213
1214 /*
1215 * Setup the thread mask for this irqaction for ONESHOT. For
1216 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1217 * conditional in irq_wake_thread().
1218 */
1219 if (new->flags & IRQF_ONESHOT) {
1220 /*
1221 * Unlikely to have 32 resp 64 irqs sharing one line,
1222 * but who knows.
1223 */
1224 if (thread_mask == ~0UL) {
1225 ret = -EBUSY;
1226 goto out_mask;
1227 }
1228 /*
1229 * The thread_mask for the action is or'ed to
1230 * desc->thread_active to indicate that the
1231 * IRQF_ONESHOT thread handler has been woken, but not
1232 * yet finished. The bit is cleared when a thread
1233 * completes. When all threads of a shared interrupt
1234 * line have completed desc->threads_active becomes
1235 * zero and the interrupt line is unmasked. See
1236 * handle.c:irq_wake_thread() for further information.
1237 *
1238 * If no thread is woken by primary (hard irq context)
1239 * interrupt handlers, then desc->threads_active is
1240 * also checked for zero to unmask the irq line in the
1241 * affected hard irq flow handlers
1242 * (handle_[fasteoi|level]_irq).
1243 *
1244 * The new action gets the first zero bit of
1245 * thread_mask assigned. See the loop above which or's
1246 * all existing action->thread_mask bits.
1247 */
1248 new->thread_mask = 1 << ffz(thread_mask);
1249
1250 } else if (new->handler == irq_default_primary_handler &&
1251 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1252 /*
1253 * The interrupt was requested with handler = NULL, so
1254 * we use the default primary handler for it. But it
1255 * does not have the oneshot flag set. In combination
1256 * with level interrupts this is deadly, because the
1257 * default primary handler just wakes the thread, then
1258 * the irq lines is reenabled, but the device still
1259 * has the level irq asserted. Rinse and repeat....
1260 *
1261 * While this works for edge type interrupts, we play
1262 * it safe and reject unconditionally because we can't
1263 * say for sure which type this interrupt really
1264 * has. The type flags are unreliable as the
1265 * underlying chip implementation can override them.
1266 */
1267 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1268 irq);
1269 ret = -EINVAL;
1270 goto out_mask;
1271 }
1272
1273 if (!shared) {
1274 ret = irq_request_resources(desc);
1275 if (ret) {
1276 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1277 new->name, irq, desc->irq_data.chip->name);
1278 goto out_mask;
1279 }
1280
1281 init_waitqueue_head(&desc->wait_for_threads);
1282
1283 /* Setup the type (level, edge polarity) if configured: */
1284 if (new->flags & IRQF_TRIGGER_MASK) {
1285 ret = __irq_set_trigger(desc,
1286 new->flags & IRQF_TRIGGER_MASK);
1287
1288 if (ret)
1289 goto out_mask;
1290 }
1291
1292 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1293 IRQS_ONESHOT | IRQS_WAITING);
1294 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1295
1296 if (new->flags & IRQF_PERCPU) {
1297 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1298 irq_settings_set_per_cpu(desc);
1299 }
1300
1301 if (new->flags & IRQF_ONESHOT)
1302 desc->istate |= IRQS_ONESHOT;
1303
1304 if (irq_settings_can_autoenable(desc))
1305 irq_startup(desc, true);
1306 else
1307 /* Undo nested disables: */
1308 desc->depth = 1;
1309
1310 /* Exclude IRQ from balancing if requested */
1311 if (new->flags & IRQF_NOBALANCING) {
1312 irq_settings_set_no_balancing(desc);
1313 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1314 }
1315
1316 /* Set default affinity mask once everything is setup */
1317 setup_affinity(desc, mask);
1318
1319 } else if (new->flags & IRQF_TRIGGER_MASK) {
1320 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1321 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1322
1323 if (nmsk != omsk)
1324 /* hope the handler works with current trigger mode */
1325 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1326 irq, nmsk, omsk);
1327 }
1328
1329 *old_ptr = new;
1330
1331 irq_pm_install_action(desc, new);
1332
1333 /* Reset broken irq detection when installing new handler */
1334 desc->irq_count = 0;
1335 desc->irqs_unhandled = 0;
1336
1337 /*
1338 * Check whether we disabled the irq via the spurious handler
1339 * before. Reenable it and give it another chance.
1340 */
1341 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1342 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1343 __enable_irq(desc);
1344 }
1345
1346 raw_spin_unlock_irqrestore(&desc->lock, flags);
1347
1348 /*
1349 * Strictly no need to wake it up, but hung_task complains
1350 * when no hard interrupt wakes the thread up.
1351 */
1352 if (new->thread)
1353 wake_up_process(new->thread);
1354 if (new->secondary)
1355 wake_up_process(new->secondary->thread);
1356
1357 register_irq_proc(irq, desc);
1358 new->dir = NULL;
1359 register_handler_proc(irq, new);
1360 free_cpumask_var(mask);
1361
1362 return 0;
1363
1364mismatch:
1365 if (!(new->flags & IRQF_PROBE_SHARED)) {
1366 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1367 irq, new->flags, new->name, old->flags, old->name);
1368#ifdef CONFIG_DEBUG_SHIRQ
1369 dump_stack();
1370#endif
1371 }
1372 ret = -EBUSY;
1373
1374out_mask:
1375 raw_spin_unlock_irqrestore(&desc->lock, flags);
1376 free_cpumask_var(mask);
1377
1378out_thread:
1379 if (new->thread) {
1380 struct task_struct *t = new->thread;
1381
1382 new->thread = NULL;
1383 kthread_stop(t);
1384 put_task_struct(t);
1385 }
1386 if (new->secondary && new->secondary->thread) {
1387 struct task_struct *t = new->secondary->thread;
1388
1389 new->secondary->thread = NULL;
1390 kthread_stop(t);
1391 put_task_struct(t);
1392 }
1393out_mput:
1394 module_put(desc->owner);
1395 return ret;
1396}
1397
1398/**
1399 * setup_irq - setup an interrupt
1400 * @irq: Interrupt line to setup
1401 * @act: irqaction for the interrupt
1402 *
1403 * Used to statically setup interrupts in the early boot process.
1404 */
1405int setup_irq(unsigned int irq, struct irqaction *act)
1406{
1407 int retval;
1408 struct irq_desc *desc = irq_to_desc(irq);
1409
1410 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1411 return -EINVAL;
1412 chip_bus_lock(desc);
1413 retval = __setup_irq(irq, desc, act);
1414 chip_bus_sync_unlock(desc);
1415
1416 return retval;
1417}
1418EXPORT_SYMBOL_GPL(setup_irq);
1419
1420/*
1421 * Internal function to unregister an irqaction - used to free
1422 * regular and special interrupts that are part of the architecture.
1423 */
1424static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1425{
1426 struct irq_desc *desc = irq_to_desc(irq);
1427 struct irqaction *action, **action_ptr;
1428 unsigned long flags;
1429
1430 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1431
1432 if (!desc)
1433 return NULL;
1434
1435 chip_bus_lock(desc);
1436 raw_spin_lock_irqsave(&desc->lock, flags);
1437
1438 /*
1439 * There can be multiple actions per IRQ descriptor, find the right
1440 * one based on the dev_id:
1441 */
1442 action_ptr = &desc->action;
1443 for (;;) {
1444 action = *action_ptr;
1445
1446 if (!action) {
1447 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1448 raw_spin_unlock_irqrestore(&desc->lock, flags);
1449 chip_bus_sync_unlock(desc);
1450 return NULL;
1451 }
1452
1453 if (action->dev_id == dev_id)
1454 break;
1455 action_ptr = &action->next;
1456 }
1457
1458 /* Found it - now remove it from the list of entries: */
1459 *action_ptr = action->next;
1460
1461 irq_pm_remove_action(desc, action);
1462
1463 /* If this was the last handler, shut down the IRQ line: */
1464 if (!desc->action) {
1465 irq_settings_clr_disable_unlazy(desc);
1466 irq_shutdown(desc);
1467 irq_release_resources(desc);
1468 }
1469
1470#ifdef CONFIG_SMP
1471 /* make sure affinity_hint is cleaned up */
1472 if (WARN_ON_ONCE(desc->affinity_hint))
1473 desc->affinity_hint = NULL;
1474#endif
1475
1476 raw_spin_unlock_irqrestore(&desc->lock, flags);
1477 chip_bus_sync_unlock(desc);
1478
1479 unregister_handler_proc(irq, action);
1480
1481 /* Make sure it's not being used on another CPU: */
1482 synchronize_irq(irq);
1483
1484#ifdef CONFIG_DEBUG_SHIRQ
1485 /*
1486 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1487 * event to happen even now it's being freed, so let's make sure that
1488 * is so by doing an extra call to the handler ....
1489 *
1490 * ( We do this after actually deregistering it, to make sure that a
1491 * 'real' IRQ doesn't run in * parallel with our fake. )
1492 */
1493 if (action->flags & IRQF_SHARED) {
1494 local_irq_save(flags);
1495 action->handler(irq, dev_id);
1496 local_irq_restore(flags);
1497 }
1498#endif
1499
1500 if (action->thread) {
1501 kthread_stop(action->thread);
1502 put_task_struct(action->thread);
1503 if (action->secondary && action->secondary->thread) {
1504 kthread_stop(action->secondary->thread);
1505 put_task_struct(action->secondary->thread);
1506 }
1507 }
1508
1509 module_put(desc->owner);
1510 kfree(action->secondary);
1511 return action;
1512}
1513
1514/**
1515 * remove_irq - free an interrupt
1516 * @irq: Interrupt line to free
1517 * @act: irqaction for the interrupt
1518 *
1519 * Used to remove interrupts statically setup by the early boot process.
1520 */
1521void remove_irq(unsigned int irq, struct irqaction *act)
1522{
1523 struct irq_desc *desc = irq_to_desc(irq);
1524
1525 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1526 __free_irq(irq, act->dev_id);
1527}
1528EXPORT_SYMBOL_GPL(remove_irq);
1529
1530/**
1531 * free_irq - free an interrupt allocated with request_irq
1532 * @irq: Interrupt line to free
1533 * @dev_id: Device identity to free
1534 *
1535 * Remove an interrupt handler. The handler is removed and if the
1536 * interrupt line is no longer in use by any driver it is disabled.
1537 * On a shared IRQ the caller must ensure the interrupt is disabled
1538 * on the card it drives before calling this function. The function
1539 * does not return until any executing interrupts for this IRQ
1540 * have completed.
1541 *
1542 * This function must not be called from interrupt context.
1543 */
1544void free_irq(unsigned int irq, void *dev_id)
1545{
1546 struct irq_desc *desc = irq_to_desc(irq);
1547
1548 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1549 return;
1550
1551#ifdef CONFIG_SMP
1552 if (WARN_ON(desc->affinity_notify))
1553 desc->affinity_notify = NULL;
1554#endif
1555
1556 kfree(__free_irq(irq, dev_id));
1557}
1558EXPORT_SYMBOL(free_irq);
1559
1560/**
1561 * request_threaded_irq - allocate an interrupt line
1562 * @irq: Interrupt line to allocate
1563 * @handler: Function to be called when the IRQ occurs.
1564 * Primary handler for threaded interrupts
1565 * If NULL and thread_fn != NULL the default
1566 * primary handler is installed
1567 * @thread_fn: Function called from the irq handler thread
1568 * If NULL, no irq thread is created
1569 * @irqflags: Interrupt type flags
1570 * @devname: An ascii name for the claiming device
1571 * @dev_id: A cookie passed back to the handler function
1572 *
1573 * This call allocates interrupt resources and enables the
1574 * interrupt line and IRQ handling. From the point this
1575 * call is made your handler function may be invoked. Since
1576 * your handler function must clear any interrupt the board
1577 * raises, you must take care both to initialise your hardware
1578 * and to set up the interrupt handler in the right order.
1579 *
1580 * If you want to set up a threaded irq handler for your device
1581 * then you need to supply @handler and @thread_fn. @handler is
1582 * still called in hard interrupt context and has to check
1583 * whether the interrupt originates from the device. If yes it
1584 * needs to disable the interrupt on the device and return
1585 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1586 * @thread_fn. This split handler design is necessary to support
1587 * shared interrupts.
1588 *
1589 * Dev_id must be globally unique. Normally the address of the
1590 * device data structure is used as the cookie. Since the handler
1591 * receives this value it makes sense to use it.
1592 *
1593 * If your interrupt is shared you must pass a non NULL dev_id
1594 * as this is required when freeing the interrupt.
1595 *
1596 * Flags:
1597 *
1598 * IRQF_SHARED Interrupt is shared
1599 * IRQF_TRIGGER_* Specify active edge(s) or level
1600 *
1601 */
1602int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1603 irq_handler_t thread_fn, unsigned long irqflags,
1604 const char *devname, void *dev_id)
1605{
1606 struct irqaction *action;
1607 struct irq_desc *desc;
1608 int retval;
1609
1610 if (irq == IRQ_NOTCONNECTED)
1611 return -ENOTCONN;
1612
1613 /*
1614 * Sanity-check: shared interrupts must pass in a real dev-ID,
1615 * otherwise we'll have trouble later trying to figure out
1616 * which interrupt is which (messes up the interrupt freeing
1617 * logic etc).
1618 *
1619 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1620 * it cannot be set along with IRQF_NO_SUSPEND.
1621 */
1622 if (((irqflags & IRQF_SHARED) && !dev_id) ||
1623 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1624 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1625 return -EINVAL;
1626
1627 desc = irq_to_desc(irq);
1628 if (!desc)
1629 return -EINVAL;
1630
1631 if (!irq_settings_can_request(desc) ||
1632 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1633 return -EINVAL;
1634
1635 if (!handler) {
1636 if (!thread_fn)
1637 return -EINVAL;
1638 handler = irq_default_primary_handler;
1639 }
1640
1641 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1642 if (!action)
1643 return -ENOMEM;
1644
1645 action->handler = handler;
1646 action->thread_fn = thread_fn;
1647 action->flags = irqflags;
1648 action->name = devname;
1649 action->dev_id = dev_id;
1650
1651 chip_bus_lock(desc);
1652 retval = __setup_irq(irq, desc, action);
1653 chip_bus_sync_unlock(desc);
1654
1655 if (retval) {
1656 kfree(action->secondary);
1657 kfree(action);
1658 }
1659
1660#ifdef CONFIG_DEBUG_SHIRQ_FIXME
1661 if (!retval && (irqflags & IRQF_SHARED)) {
1662 /*
1663 * It's a shared IRQ -- the driver ought to be prepared for it
1664 * to happen immediately, so let's make sure....
1665 * We disable the irq to make sure that a 'real' IRQ doesn't
1666 * run in parallel with our fake.
1667 */
1668 unsigned long flags;
1669
1670 disable_irq(irq);
1671 local_irq_save(flags);
1672
1673 handler(irq, dev_id);
1674
1675 local_irq_restore(flags);
1676 enable_irq(irq);
1677 }
1678#endif
1679 return retval;
1680}
1681EXPORT_SYMBOL(request_threaded_irq);
1682
1683/**
1684 * request_any_context_irq - allocate an interrupt line
1685 * @irq: Interrupt line to allocate
1686 * @handler: Function to be called when the IRQ occurs.
1687 * Threaded handler for threaded interrupts.
1688 * @flags: Interrupt type flags
1689 * @name: An ascii name for the claiming device
1690 * @dev_id: A cookie passed back to the handler function
1691 *
1692 * This call allocates interrupt resources and enables the
1693 * interrupt line and IRQ handling. It selects either a
1694 * hardirq or threaded handling method depending on the
1695 * context.
1696 *
1697 * On failure, it returns a negative value. On success,
1698 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1699 */
1700int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1701 unsigned long flags, const char *name, void *dev_id)
1702{
1703 struct irq_desc *desc;
1704 int ret;
1705
1706 if (irq == IRQ_NOTCONNECTED)
1707 return -ENOTCONN;
1708
1709 desc = irq_to_desc(irq);
1710 if (!desc)
1711 return -EINVAL;
1712
1713 if (irq_settings_is_nested_thread(desc)) {
1714 ret = request_threaded_irq(irq, NULL, handler,
1715 flags, name, dev_id);
1716 return !ret ? IRQC_IS_NESTED : ret;
1717 }
1718
1719 ret = request_irq(irq, handler, flags, name, dev_id);
1720 return !ret ? IRQC_IS_HARDIRQ : ret;
1721}
1722EXPORT_SYMBOL_GPL(request_any_context_irq);
1723
1724void enable_percpu_irq(unsigned int irq, unsigned int type)
1725{
1726 unsigned int cpu = smp_processor_id();
1727 unsigned long flags;
1728 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1729
1730 if (!desc)
1731 return;
1732
1733 type &= IRQ_TYPE_SENSE_MASK;
1734 if (type != IRQ_TYPE_NONE) {
1735 int ret;
1736
1737 ret = __irq_set_trigger(desc, type);
1738
1739 if (ret) {
1740 WARN(1, "failed to set type for IRQ%d\n", irq);
1741 goto out;
1742 }
1743 }
1744
1745 irq_percpu_enable(desc, cpu);
1746out:
1747 irq_put_desc_unlock(desc, flags);
1748}
1749EXPORT_SYMBOL_GPL(enable_percpu_irq);
1750
1751/**
1752 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1753 * @irq: Linux irq number to check for
1754 *
1755 * Must be called from a non migratable context. Returns the enable
1756 * state of a per cpu interrupt on the current cpu.
1757 */
1758bool irq_percpu_is_enabled(unsigned int irq)
1759{
1760 unsigned int cpu = smp_processor_id();
1761 struct irq_desc *desc;
1762 unsigned long flags;
1763 bool is_enabled;
1764
1765 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1766 if (!desc)
1767 return false;
1768
1769 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1770 irq_put_desc_unlock(desc, flags);
1771
1772 return is_enabled;
1773}
1774EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1775
1776void disable_percpu_irq(unsigned int irq)
1777{
1778 unsigned int cpu = smp_processor_id();
1779 unsigned long flags;
1780 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1781
1782 if (!desc)
1783 return;
1784
1785 irq_percpu_disable(desc, cpu);
1786 irq_put_desc_unlock(desc, flags);
1787}
1788EXPORT_SYMBOL_GPL(disable_percpu_irq);
1789
1790/*
1791 * Internal function to unregister a percpu irqaction.
1792 */
1793static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1794{
1795 struct irq_desc *desc = irq_to_desc(irq);
1796 struct irqaction *action;
1797 unsigned long flags;
1798
1799 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1800
1801 if (!desc)
1802 return NULL;
1803
1804 raw_spin_lock_irqsave(&desc->lock, flags);
1805
1806 action = desc->action;
1807 if (!action || action->percpu_dev_id != dev_id) {
1808 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1809 goto bad;
1810 }
1811
1812 if (!cpumask_empty(desc->percpu_enabled)) {
1813 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1814 irq, cpumask_first(desc->percpu_enabled));
1815 goto bad;
1816 }
1817
1818 /* Found it - now remove it from the list of entries: */
1819 desc->action = NULL;
1820
1821 raw_spin_unlock_irqrestore(&desc->lock, flags);
1822
1823 unregister_handler_proc(irq, action);
1824
1825 module_put(desc->owner);
1826 return action;
1827
1828bad:
1829 raw_spin_unlock_irqrestore(&desc->lock, flags);
1830 return NULL;
1831}
1832
1833/**
1834 * remove_percpu_irq - free a per-cpu interrupt
1835 * @irq: Interrupt line to free
1836 * @act: irqaction for the interrupt
1837 *
1838 * Used to remove interrupts statically setup by the early boot process.
1839 */
1840void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1841{
1842 struct irq_desc *desc = irq_to_desc(irq);
1843
1844 if (desc && irq_settings_is_per_cpu_devid(desc))
1845 __free_percpu_irq(irq, act->percpu_dev_id);
1846}
1847
1848/**
1849 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1850 * @irq: Interrupt line to free
1851 * @dev_id: Device identity to free
1852 *
1853 * Remove a percpu interrupt handler. The handler is removed, but
1854 * the interrupt line is not disabled. This must be done on each
1855 * CPU before calling this function. The function does not return
1856 * until any executing interrupts for this IRQ have completed.
1857 *
1858 * This function must not be called from interrupt context.
1859 */
1860void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1861{
1862 struct irq_desc *desc = irq_to_desc(irq);
1863
1864 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1865 return;
1866
1867 chip_bus_lock(desc);
1868 kfree(__free_percpu_irq(irq, dev_id));
1869 chip_bus_sync_unlock(desc);
1870}
1871EXPORT_SYMBOL_GPL(free_percpu_irq);
1872
1873/**
1874 * setup_percpu_irq - setup a per-cpu interrupt
1875 * @irq: Interrupt line to setup
1876 * @act: irqaction for the interrupt
1877 *
1878 * Used to statically setup per-cpu interrupts in the early boot process.
1879 */
1880int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1881{
1882 struct irq_desc *desc = irq_to_desc(irq);
1883 int retval;
1884
1885 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1886 return -EINVAL;
1887 chip_bus_lock(desc);
1888 retval = __setup_irq(irq, desc, act);
1889 chip_bus_sync_unlock(desc);
1890
1891 return retval;
1892}
1893
1894/**
1895 * request_percpu_irq - allocate a percpu interrupt line
1896 * @irq: Interrupt line to allocate
1897 * @handler: Function to be called when the IRQ occurs.
1898 * @devname: An ascii name for the claiming device
1899 * @dev_id: A percpu cookie passed back to the handler function
1900 *
1901 * This call allocates interrupt resources and enables the
1902 * interrupt on the local CPU. If the interrupt is supposed to be
1903 * enabled on other CPUs, it has to be done on each CPU using
1904 * enable_percpu_irq().
1905 *
1906 * Dev_id must be globally unique. It is a per-cpu variable, and
1907 * the handler gets called with the interrupted CPU's instance of
1908 * that variable.
1909 */
1910int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1911 const char *devname, void __percpu *dev_id)
1912{
1913 struct irqaction *action;
1914 struct irq_desc *desc;
1915 int retval;
1916
1917 if (!dev_id)
1918 return -EINVAL;
1919
1920 desc = irq_to_desc(irq);
1921 if (!desc || !irq_settings_can_request(desc) ||
1922 !irq_settings_is_per_cpu_devid(desc))
1923 return -EINVAL;
1924
1925 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1926 if (!action)
1927 return -ENOMEM;
1928
1929 action->handler = handler;
1930 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1931 action->name = devname;
1932 action->percpu_dev_id = dev_id;
1933
1934 chip_bus_lock(desc);
1935 retval = __setup_irq(irq, desc, action);
1936 chip_bus_sync_unlock(desc);
1937
1938 if (retval)
1939 kfree(action);
1940
1941 return retval;
1942}
1943EXPORT_SYMBOL_GPL(request_percpu_irq);
1944
1945/**
1946 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
1947 * @irq: Interrupt line that is forwarded to a VM
1948 * @which: One of IRQCHIP_STATE_* the caller wants to know about
1949 * @state: a pointer to a boolean where the state is to be storeed
1950 *
1951 * This call snapshots the internal irqchip state of an
1952 * interrupt, returning into @state the bit corresponding to
1953 * stage @which
1954 *
1955 * This function should be called with preemption disabled if the
1956 * interrupt controller has per-cpu registers.
1957 */
1958int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
1959 bool *state)
1960{
1961 struct irq_desc *desc;
1962 struct irq_data *data;
1963 struct irq_chip *chip;
1964 unsigned long flags;
1965 int err = -EINVAL;
1966
1967 desc = irq_get_desc_buslock(irq, &flags, 0);
1968 if (!desc)
1969 return err;
1970
1971 data = irq_desc_get_irq_data(desc);
1972
1973 do {
1974 chip = irq_data_get_irq_chip(data);
1975 if (chip->irq_get_irqchip_state)
1976 break;
1977#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1978 data = data->parent_data;
1979#else
1980 data = NULL;
1981#endif
1982 } while (data);
1983
1984 if (data)
1985 err = chip->irq_get_irqchip_state(data, which, state);
1986
1987 irq_put_desc_busunlock(desc, flags);
1988 return err;
1989}
1990EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
1991
1992/**
1993 * irq_set_irqchip_state - set the state of a forwarded interrupt.
1994 * @irq: Interrupt line that is forwarded to a VM
1995 * @which: State to be restored (one of IRQCHIP_STATE_*)
1996 * @val: Value corresponding to @which
1997 *
1998 * This call sets the internal irqchip state of an interrupt,
1999 * depending on the value of @which.
2000 *
2001 * This function should be called with preemption disabled if the
2002 * interrupt controller has per-cpu registers.
2003 */
2004int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2005 bool val)
2006{
2007 struct irq_desc *desc;
2008 struct irq_data *data;
2009 struct irq_chip *chip;
2010 unsigned long flags;
2011 int err = -EINVAL;
2012
2013 desc = irq_get_desc_buslock(irq, &flags, 0);
2014 if (!desc)
2015 return err;
2016
2017 data = irq_desc_get_irq_data(desc);
2018
2019 do {
2020 chip = irq_data_get_irq_chip(data);
2021 if (chip->irq_set_irqchip_state)
2022 break;
2023#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2024 data = data->parent_data;
2025#else
2026 data = NULL;
2027#endif
2028 } while (data);
2029
2030 if (data)
2031 err = chip->irq_set_irqchip_state(data, which, val);
2032
2033 irq_put_desc_busunlock(desc, flags);
2034 return err;
2035}
2036EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
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)
28__read_mostly bool force_irqthreads;
29EXPORT_SYMBOL_GPL(force_irqthreads);
30
31static int __init setup_forced_irqthreads(char *arg)
32{
33 force_irqthreads = true;
34 return 0;
35}
36early_param("threadirqs", setup_forced_irqthreads);
37#endif
38
39static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
40{
41 struct irq_data *irqd = irq_desc_get_irq_data(desc);
42 bool inprogress;
43
44 do {
45 unsigned long flags;
46
47 /*
48 * Wait until we're out of the critical section. This might
49 * give the wrong answer due to the lack of memory barriers.
50 */
51 while (irqd_irq_inprogress(&desc->irq_data))
52 cpu_relax();
53
54 /* Ok, that indicated we're done: double-check carefully. */
55 raw_spin_lock_irqsave(&desc->lock, flags);
56 inprogress = irqd_irq_inprogress(&desc->irq_data);
57
58 /*
59 * If requested and supported, check at the chip whether it
60 * is in flight at the hardware level, i.e. already pending
61 * in a CPU and waiting for service and acknowledge.
62 */
63 if (!inprogress && sync_chip) {
64 /*
65 * Ignore the return code. inprogress is only updated
66 * when the chip supports it.
67 */
68 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
69 &inprogress);
70 }
71 raw_spin_unlock_irqrestore(&desc->lock, flags);
72
73 /* Oops, that failed? */
74 } while (inprogress);
75}
76
77/**
78 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
79 * @irq: interrupt number to wait for
80 *
81 * This function waits for any pending hard IRQ handlers for this
82 * interrupt to complete before returning. If you use this
83 * function while holding a resource the IRQ handler may need you
84 * will deadlock. It does not take associated threaded handlers
85 * into account.
86 *
87 * Do not use this for shutdown scenarios where you must be sure
88 * that all parts (hardirq and threaded handler) have completed.
89 *
90 * Returns: false if a threaded handler is active.
91 *
92 * This function may be called - with care - from IRQ context.
93 *
94 * It does not check whether there is an interrupt in flight at the
95 * hardware level, but not serviced yet, as this might deadlock when
96 * called with interrupts disabled and the target CPU of the interrupt
97 * is the current CPU.
98 */
99bool synchronize_hardirq(unsigned int irq)
100{
101 struct irq_desc *desc = irq_to_desc(irq);
102
103 if (desc) {
104 __synchronize_hardirq(desc, false);
105 return !atomic_read(&desc->threads_active);
106 }
107
108 return true;
109}
110EXPORT_SYMBOL(synchronize_hardirq);
111
112/**
113 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
114 * @irq: interrupt number to wait for
115 *
116 * This function waits for any pending IRQ handlers for this interrupt
117 * to complete before returning. If you use this function while
118 * holding a resource the IRQ handler may need you will deadlock.
119 *
120 * Can only be called from preemptible code as it might sleep when
121 * an interrupt thread is associated to @irq.
122 *
123 * It optionally makes sure (when the irq chip supports that method)
124 * that the interrupt is not pending in any CPU and waiting for
125 * service.
126 */
127void synchronize_irq(unsigned int irq)
128{
129 struct irq_desc *desc = irq_to_desc(irq);
130
131 if (desc) {
132 __synchronize_hardirq(desc, true);
133 /*
134 * We made sure that no hardirq handler is
135 * running. Now verify that no threaded handlers are
136 * active.
137 */
138 wait_event(desc->wait_for_threads,
139 !atomic_read(&desc->threads_active));
140 }
141}
142EXPORT_SYMBOL(synchronize_irq);
143
144#ifdef CONFIG_SMP
145cpumask_var_t irq_default_affinity;
146
147static bool __irq_can_set_affinity(struct irq_desc *desc)
148{
149 if (!desc || !irqd_can_balance(&desc->irq_data) ||
150 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
151 return false;
152 return true;
153}
154
155/**
156 * irq_can_set_affinity - Check if the affinity of a given irq can be set
157 * @irq: Interrupt to check
158 *
159 */
160int irq_can_set_affinity(unsigned int irq)
161{
162 return __irq_can_set_affinity(irq_to_desc(irq));
163}
164
165/**
166 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
167 * @irq: Interrupt to check
168 *
169 * Like irq_can_set_affinity() above, but additionally checks for the
170 * AFFINITY_MANAGED flag.
171 */
172bool irq_can_set_affinity_usr(unsigned int irq)
173{
174 struct irq_desc *desc = irq_to_desc(irq);
175
176 return __irq_can_set_affinity(desc) &&
177 !irqd_affinity_is_managed(&desc->irq_data);
178}
179
180/**
181 * irq_set_thread_affinity - Notify irq threads to adjust affinity
182 * @desc: irq descriptor which has affitnity changed
183 *
184 * We just set IRQTF_AFFINITY and delegate the affinity setting
185 * to the interrupt thread itself. We can not call
186 * set_cpus_allowed_ptr() here as we hold desc->lock and this
187 * code can be called from hard interrupt context.
188 */
189void irq_set_thread_affinity(struct irq_desc *desc)
190{
191 struct irqaction *action;
192
193 for_each_action_of_desc(desc, action)
194 if (action->thread)
195 set_bit(IRQTF_AFFINITY, &action->thread_flags);
196}
197
198#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
199static void irq_validate_effective_affinity(struct irq_data *data)
200{
201 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
202 struct irq_chip *chip = irq_data_get_irq_chip(data);
203
204 if (!cpumask_empty(m))
205 return;
206 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
207 chip->name, data->irq);
208}
209
210static inline void irq_init_effective_affinity(struct irq_data *data,
211 const struct cpumask *mask)
212{
213 cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
214}
215#else
216static inline void irq_validate_effective_affinity(struct irq_data *data) { }
217static inline void irq_init_effective_affinity(struct irq_data *data,
218 const struct cpumask *mask) { }
219#endif
220
221int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
222 bool force)
223{
224 struct irq_desc *desc = irq_data_to_desc(data);
225 struct irq_chip *chip = irq_data_get_irq_chip(data);
226 int ret;
227
228 if (!chip || !chip->irq_set_affinity)
229 return -EINVAL;
230
231 /*
232 * If this is a managed interrupt and housekeeping is enabled on
233 * it check whether the requested affinity mask intersects with
234 * a housekeeping CPU. If so, then remove the isolated CPUs from
235 * the mask and just keep the housekeeping CPU(s). This prevents
236 * the affinity setter from routing the interrupt to an isolated
237 * CPU to avoid that I/O submitted from a housekeeping CPU causes
238 * interrupts on an isolated one.
239 *
240 * If the masks do not intersect or include online CPU(s) then
241 * keep the requested mask. The isolated target CPUs are only
242 * receiving interrupts when the I/O operation was submitted
243 * directly from them.
244 *
245 * If all housekeeping CPUs in the affinity mask are offline, the
246 * interrupt will be migrated by the CPU hotplug code once a
247 * housekeeping CPU which belongs to the affinity mask comes
248 * online.
249 */
250 if (irqd_affinity_is_managed(data) &&
251 housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
252 const struct cpumask *hk_mask, *prog_mask;
253
254 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
255 static struct cpumask tmp_mask;
256
257 hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
258
259 raw_spin_lock(&tmp_mask_lock);
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 ret = chip->irq_set_affinity(data, prog_mask, force);
266 raw_spin_unlock(&tmp_mask_lock);
267 } else {
268 ret = chip->irq_set_affinity(data, mask, force);
269 }
270 switch (ret) {
271 case IRQ_SET_MASK_OK:
272 case IRQ_SET_MASK_OK_DONE:
273 cpumask_copy(desc->irq_common_data.affinity, mask);
274 fallthrough;
275 case IRQ_SET_MASK_OK_NOCOPY:
276 irq_validate_effective_affinity(data);
277 irq_set_thread_affinity(desc);
278 ret = 0;
279 }
280
281 return ret;
282}
283
284#ifdef CONFIG_GENERIC_PENDING_IRQ
285static inline int irq_set_affinity_pending(struct irq_data *data,
286 const struct cpumask *dest)
287{
288 struct irq_desc *desc = irq_data_to_desc(data);
289
290 irqd_set_move_pending(data);
291 irq_copy_pending(desc, dest);
292 return 0;
293}
294#else
295static inline int irq_set_affinity_pending(struct irq_data *data,
296 const struct cpumask *dest)
297{
298 return -EBUSY;
299}
300#endif
301
302static int irq_try_set_affinity(struct irq_data *data,
303 const struct cpumask *dest, bool force)
304{
305 int ret = irq_do_set_affinity(data, dest, force);
306
307 /*
308 * In case that the underlying vector management is busy and the
309 * architecture supports the generic pending mechanism then utilize
310 * this to avoid returning an error to user space.
311 */
312 if (ret == -EBUSY && !force)
313 ret = irq_set_affinity_pending(data, dest);
314 return ret;
315}
316
317static bool irq_set_affinity_deactivated(struct irq_data *data,
318 const struct cpumask *mask, bool force)
319{
320 struct irq_desc *desc = irq_data_to_desc(data);
321
322 /*
323 * Handle irq chips which can handle affinity only in activated
324 * state correctly
325 *
326 * If the interrupt is not yet activated, just store the affinity
327 * mask and do not call the chip driver at all. On activation the
328 * driver has to make sure anyway that the interrupt is in a
329 * useable state so startup works.
330 */
331 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
332 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
333 return false;
334
335 cpumask_copy(desc->irq_common_data.affinity, mask);
336 irq_init_effective_affinity(data, mask);
337 irqd_set(data, IRQD_AFFINITY_SET);
338 return true;
339}
340
341int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
342 bool force)
343{
344 struct irq_chip *chip = irq_data_get_irq_chip(data);
345 struct irq_desc *desc = irq_data_to_desc(data);
346 int ret = 0;
347
348 if (!chip || !chip->irq_set_affinity)
349 return -EINVAL;
350
351 if (irq_set_affinity_deactivated(data, mask, force))
352 return 0;
353
354 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
355 ret = irq_try_set_affinity(data, mask, force);
356 } else {
357 irqd_set_move_pending(data);
358 irq_copy_pending(desc, mask);
359 }
360
361 if (desc->affinity_notify) {
362 kref_get(&desc->affinity_notify->kref);
363 if (!schedule_work(&desc->affinity_notify->work)) {
364 /* Work was already scheduled, drop our extra ref */
365 kref_put(&desc->affinity_notify->kref,
366 desc->affinity_notify->release);
367 }
368 }
369 irqd_set(data, IRQD_AFFINITY_SET);
370
371 return ret;
372}
373
374int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
375{
376 struct irq_desc *desc = irq_to_desc(irq);
377 unsigned long flags;
378 int ret;
379
380 if (!desc)
381 return -EINVAL;
382
383 raw_spin_lock_irqsave(&desc->lock, flags);
384 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
385 raw_spin_unlock_irqrestore(&desc->lock, flags);
386 return ret;
387}
388
389int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
390{
391 unsigned long flags;
392 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
393
394 if (!desc)
395 return -EINVAL;
396 desc->affinity_hint = m;
397 irq_put_desc_unlock(desc, flags);
398 /* set the initial affinity to prevent every interrupt being on CPU0 */
399 if (m)
400 __irq_set_affinity(irq, m, false);
401 return 0;
402}
403EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
404
405static void irq_affinity_notify(struct work_struct *work)
406{
407 struct irq_affinity_notify *notify =
408 container_of(work, struct irq_affinity_notify, work);
409 struct irq_desc *desc = irq_to_desc(notify->irq);
410 cpumask_var_t cpumask;
411 unsigned long flags;
412
413 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
414 goto out;
415
416 raw_spin_lock_irqsave(&desc->lock, flags);
417 if (irq_move_pending(&desc->irq_data))
418 irq_get_pending(cpumask, desc);
419 else
420 cpumask_copy(cpumask, desc->irq_common_data.affinity);
421 raw_spin_unlock_irqrestore(&desc->lock, flags);
422
423 notify->notify(notify, cpumask);
424
425 free_cpumask_var(cpumask);
426out:
427 kref_put(¬ify->kref, notify->release);
428}
429
430/**
431 * irq_set_affinity_notifier - control notification of IRQ affinity changes
432 * @irq: Interrupt for which to enable/disable notification
433 * @notify: Context for notification, or %NULL to disable
434 * notification. Function pointers must be initialised;
435 * the other fields will be initialised by this function.
436 *
437 * Must be called in process context. Notification may only be enabled
438 * after the IRQ is allocated and must be disabled before the IRQ is
439 * freed using free_irq().
440 */
441int
442irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
443{
444 struct irq_desc *desc = irq_to_desc(irq);
445 struct irq_affinity_notify *old_notify;
446 unsigned long flags;
447
448 /* The release function is promised process context */
449 might_sleep();
450
451 if (!desc || desc->istate & IRQS_NMI)
452 return -EINVAL;
453
454 /* Complete initialisation of *notify */
455 if (notify) {
456 notify->irq = irq;
457 kref_init(¬ify->kref);
458 INIT_WORK(¬ify->work, irq_affinity_notify);
459 }
460
461 raw_spin_lock_irqsave(&desc->lock, flags);
462 old_notify = desc->affinity_notify;
463 desc->affinity_notify = notify;
464 raw_spin_unlock_irqrestore(&desc->lock, flags);
465
466 if (old_notify) {
467 if (cancel_work_sync(&old_notify->work)) {
468 /* Pending work had a ref, put that one too */
469 kref_put(&old_notify->kref, old_notify->release);
470 }
471 kref_put(&old_notify->kref, old_notify->release);
472 }
473
474 return 0;
475}
476EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
477
478#ifndef CONFIG_AUTO_IRQ_AFFINITY
479/*
480 * Generic version of the affinity autoselector.
481 */
482int irq_setup_affinity(struct irq_desc *desc)
483{
484 struct cpumask *set = irq_default_affinity;
485 int ret, node = irq_desc_get_node(desc);
486 static DEFINE_RAW_SPINLOCK(mask_lock);
487 static struct cpumask mask;
488
489 /* Excludes PER_CPU and NO_BALANCE interrupts */
490 if (!__irq_can_set_affinity(desc))
491 return 0;
492
493 raw_spin_lock(&mask_lock);
494 /*
495 * Preserve the managed affinity setting and a userspace affinity
496 * setup, but make sure that one of the targets is online.
497 */
498 if (irqd_affinity_is_managed(&desc->irq_data) ||
499 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
500 if (cpumask_intersects(desc->irq_common_data.affinity,
501 cpu_online_mask))
502 set = desc->irq_common_data.affinity;
503 else
504 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
505 }
506
507 cpumask_and(&mask, cpu_online_mask, set);
508 if (cpumask_empty(&mask))
509 cpumask_copy(&mask, cpu_online_mask);
510
511 if (node != NUMA_NO_NODE) {
512 const struct cpumask *nodemask = cpumask_of_node(node);
513
514 /* make sure at least one of the cpus in nodemask is online */
515 if (cpumask_intersects(&mask, nodemask))
516 cpumask_and(&mask, &mask, nodemask);
517 }
518 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
519 raw_spin_unlock(&mask_lock);
520 return ret;
521}
522#else
523/* Wrapper for ALPHA specific affinity selector magic */
524int irq_setup_affinity(struct irq_desc *desc)
525{
526 return irq_select_affinity(irq_desc_get_irq(desc));
527}
528#endif /* CONFIG_AUTO_IRQ_AFFINITY */
529#endif /* CONFIG_SMP */
530
531
532/**
533 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
534 * @irq: interrupt number to set affinity
535 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
536 * specific data for percpu_devid interrupts
537 *
538 * This function uses the vCPU specific data to set the vCPU
539 * affinity for an irq. The vCPU specific data is passed from
540 * outside, such as KVM. One example code path is as below:
541 * KVM -> IOMMU -> irq_set_vcpu_affinity().
542 */
543int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
544{
545 unsigned long flags;
546 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
547 struct irq_data *data;
548 struct irq_chip *chip;
549 int ret = -ENOSYS;
550
551 if (!desc)
552 return -EINVAL;
553
554 data = irq_desc_get_irq_data(desc);
555 do {
556 chip = irq_data_get_irq_chip(data);
557 if (chip && chip->irq_set_vcpu_affinity)
558 break;
559#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
560 data = data->parent_data;
561#else
562 data = NULL;
563#endif
564 } while (data);
565
566 if (data)
567 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
568 irq_put_desc_unlock(desc, flags);
569
570 return ret;
571}
572EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
573
574void __disable_irq(struct irq_desc *desc)
575{
576 if (!desc->depth++)
577 irq_disable(desc);
578}
579
580static int __disable_irq_nosync(unsigned int irq)
581{
582 unsigned long flags;
583 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
584
585 if (!desc)
586 return -EINVAL;
587 __disable_irq(desc);
588 irq_put_desc_busunlock(desc, flags);
589 return 0;
590}
591
592/**
593 * disable_irq_nosync - disable an irq without waiting
594 * @irq: Interrupt to disable
595 *
596 * Disable the selected interrupt line. Disables and Enables are
597 * nested.
598 * Unlike disable_irq(), this function does not ensure existing
599 * instances of the IRQ handler have completed before returning.
600 *
601 * This function may be called from IRQ context.
602 */
603void disable_irq_nosync(unsigned int irq)
604{
605 __disable_irq_nosync(irq);
606}
607EXPORT_SYMBOL(disable_irq_nosync);
608
609/**
610 * disable_irq - disable an irq and wait for completion
611 * @irq: Interrupt to disable
612 *
613 * Disable the selected interrupt line. Enables and Disables are
614 * nested.
615 * This function waits for any pending IRQ handlers for this interrupt
616 * to complete before returning. If you use this function while
617 * holding a resource the IRQ handler may need you will deadlock.
618 *
619 * This function may be called - with care - from IRQ context.
620 */
621void disable_irq(unsigned int irq)
622{
623 if (!__disable_irq_nosync(irq))
624 synchronize_irq(irq);
625}
626EXPORT_SYMBOL(disable_irq);
627
628/**
629 * disable_hardirq - disables an irq and waits for hardirq completion
630 * @irq: Interrupt to disable
631 *
632 * Disable the selected interrupt line. Enables and Disables are
633 * nested.
634 * This function waits for any pending hard IRQ handlers for this
635 * interrupt to complete before returning. If you use this function while
636 * holding a resource the hard IRQ handler may need you will deadlock.
637 *
638 * When used to optimistically disable an interrupt from atomic context
639 * the return value must be checked.
640 *
641 * Returns: false if a threaded handler is active.
642 *
643 * This function may be called - with care - from IRQ context.
644 */
645bool disable_hardirq(unsigned int irq)
646{
647 if (!__disable_irq_nosync(irq))
648 return synchronize_hardirq(irq);
649
650 return false;
651}
652EXPORT_SYMBOL_GPL(disable_hardirq);
653
654/**
655 * disable_nmi_nosync - disable an nmi without waiting
656 * @irq: Interrupt to disable
657 *
658 * Disable the selected interrupt line. Disables and enables are
659 * nested.
660 * The interrupt to disable must have been requested through request_nmi.
661 * Unlike disable_nmi(), this function does not ensure existing
662 * instances of the IRQ handler have completed before returning.
663 */
664void disable_nmi_nosync(unsigned int irq)
665{
666 disable_irq_nosync(irq);
667}
668
669void __enable_irq(struct irq_desc *desc)
670{
671 switch (desc->depth) {
672 case 0:
673 err_out:
674 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
675 irq_desc_get_irq(desc));
676 break;
677 case 1: {
678 if (desc->istate & IRQS_SUSPENDED)
679 goto err_out;
680 /* Prevent probing on this irq: */
681 irq_settings_set_noprobe(desc);
682 /*
683 * Call irq_startup() not irq_enable() here because the
684 * interrupt might be marked NOAUTOEN. So irq_startup()
685 * needs to be invoked when it gets enabled the first
686 * time. If it was already started up, then irq_startup()
687 * will invoke irq_enable() under the hood.
688 */
689 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
690 break;
691 }
692 default:
693 desc->depth--;
694 }
695}
696
697/**
698 * enable_irq - enable handling of an irq
699 * @irq: Interrupt to enable
700 *
701 * Undoes the effect of one call to disable_irq(). If this
702 * matches the last disable, processing of interrupts on this
703 * IRQ line is re-enabled.
704 *
705 * This function may be called from IRQ context only when
706 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
707 */
708void enable_irq(unsigned int irq)
709{
710 unsigned long flags;
711 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
712
713 if (!desc)
714 return;
715 if (WARN(!desc->irq_data.chip,
716 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
717 goto out;
718
719 __enable_irq(desc);
720out:
721 irq_put_desc_busunlock(desc, flags);
722}
723EXPORT_SYMBOL(enable_irq);
724
725/**
726 * enable_nmi - enable handling of an nmi
727 * @irq: Interrupt to enable
728 *
729 * The interrupt to enable must have been requested through request_nmi.
730 * Undoes the effect of one call to disable_nmi(). If this
731 * matches the last disable, processing of interrupts on this
732 * IRQ line is re-enabled.
733 */
734void enable_nmi(unsigned int irq)
735{
736 enable_irq(irq);
737}
738
739static int set_irq_wake_real(unsigned int irq, unsigned int on)
740{
741 struct irq_desc *desc = irq_to_desc(irq);
742 int ret = -ENXIO;
743
744 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
745 return 0;
746
747 if (desc->irq_data.chip->irq_set_wake)
748 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
749
750 return ret;
751}
752
753/**
754 * irq_set_irq_wake - control irq power management wakeup
755 * @irq: interrupt to control
756 * @on: enable/disable power management wakeup
757 *
758 * Enable/disable power management wakeup mode, which is
759 * disabled by default. Enables and disables must match,
760 * just as they match for non-wakeup mode support.
761 *
762 * Wakeup mode lets this IRQ wake the system from sleep
763 * states like "suspend to RAM".
764 *
765 * Note: irq enable/disable state is completely orthogonal
766 * to the enable/disable state of irq wake. An irq can be
767 * disabled with disable_irq() and still wake the system as
768 * long as the irq has wake enabled. If this does not hold,
769 * then the underlying irq chip and the related driver need
770 * to be investigated.
771 */
772int irq_set_irq_wake(unsigned int irq, unsigned int on)
773{
774 unsigned long flags;
775 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
776 int ret = 0;
777
778 if (!desc)
779 return -EINVAL;
780
781 /* Don't use NMIs as wake up interrupts please */
782 if (desc->istate & IRQS_NMI) {
783 ret = -EINVAL;
784 goto out_unlock;
785 }
786
787 /* wakeup-capable irqs can be shared between drivers that
788 * don't need to have the same sleep mode behaviors.
789 */
790 if (on) {
791 if (desc->wake_depth++ == 0) {
792 ret = set_irq_wake_real(irq, on);
793 if (ret)
794 desc->wake_depth = 0;
795 else
796 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
797 }
798 } else {
799 if (desc->wake_depth == 0) {
800 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
801 } else if (--desc->wake_depth == 0) {
802 ret = set_irq_wake_real(irq, on);
803 if (ret)
804 desc->wake_depth = 1;
805 else
806 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
807 }
808 }
809
810out_unlock:
811 irq_put_desc_busunlock(desc, flags);
812 return ret;
813}
814EXPORT_SYMBOL(irq_set_irq_wake);
815
816/*
817 * Internal function that tells the architecture code whether a
818 * particular irq has been exclusively allocated or is available
819 * for driver use.
820 */
821int can_request_irq(unsigned int irq, unsigned long irqflags)
822{
823 unsigned long flags;
824 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
825 int canrequest = 0;
826
827 if (!desc)
828 return 0;
829
830 if (irq_settings_can_request(desc)) {
831 if (!desc->action ||
832 irqflags & desc->action->flags & IRQF_SHARED)
833 canrequest = 1;
834 }
835 irq_put_desc_unlock(desc, flags);
836 return canrequest;
837}
838
839int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
840{
841 struct irq_chip *chip = desc->irq_data.chip;
842 int ret, unmask = 0;
843
844 if (!chip || !chip->irq_set_type) {
845 /*
846 * IRQF_TRIGGER_* but the PIC does not support multiple
847 * flow-types?
848 */
849 pr_debug("No set_type function for IRQ %d (%s)\n",
850 irq_desc_get_irq(desc),
851 chip ? (chip->name ? : "unknown") : "unknown");
852 return 0;
853 }
854
855 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
856 if (!irqd_irq_masked(&desc->irq_data))
857 mask_irq(desc);
858 if (!irqd_irq_disabled(&desc->irq_data))
859 unmask = 1;
860 }
861
862 /* Mask all flags except trigger mode */
863 flags &= IRQ_TYPE_SENSE_MASK;
864 ret = chip->irq_set_type(&desc->irq_data, flags);
865
866 switch (ret) {
867 case IRQ_SET_MASK_OK:
868 case IRQ_SET_MASK_OK_DONE:
869 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
870 irqd_set(&desc->irq_data, flags);
871 fallthrough;
872
873 case IRQ_SET_MASK_OK_NOCOPY:
874 flags = irqd_get_trigger_type(&desc->irq_data);
875 irq_settings_set_trigger_mask(desc, flags);
876 irqd_clear(&desc->irq_data, IRQD_LEVEL);
877 irq_settings_clr_level(desc);
878 if (flags & IRQ_TYPE_LEVEL_MASK) {
879 irq_settings_set_level(desc);
880 irqd_set(&desc->irq_data, IRQD_LEVEL);
881 }
882
883 ret = 0;
884 break;
885 default:
886 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
887 flags, irq_desc_get_irq(desc), chip->irq_set_type);
888 }
889 if (unmask)
890 unmask_irq(desc);
891 return ret;
892}
893
894#ifdef CONFIG_HARDIRQS_SW_RESEND
895int irq_set_parent(int irq, int parent_irq)
896{
897 unsigned long flags;
898 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
899
900 if (!desc)
901 return -EINVAL;
902
903 desc->parent_irq = parent_irq;
904
905 irq_put_desc_unlock(desc, flags);
906 return 0;
907}
908EXPORT_SYMBOL_GPL(irq_set_parent);
909#endif
910
911/*
912 * Default primary interrupt handler for threaded interrupts. Is
913 * assigned as primary handler when request_threaded_irq is called
914 * with handler == NULL. Useful for oneshot interrupts.
915 */
916static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
917{
918 return IRQ_WAKE_THREAD;
919}
920
921/*
922 * Primary handler for nested threaded interrupts. Should never be
923 * called.
924 */
925static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
926{
927 WARN(1, "Primary handler called for nested irq %d\n", irq);
928 return IRQ_NONE;
929}
930
931static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
932{
933 WARN(1, "Secondary action handler called for irq %d\n", irq);
934 return IRQ_NONE;
935}
936
937static int irq_wait_for_interrupt(struct irqaction *action)
938{
939 for (;;) {
940 set_current_state(TASK_INTERRUPTIBLE);
941
942 if (kthread_should_stop()) {
943 /* may need to run one last time */
944 if (test_and_clear_bit(IRQTF_RUNTHREAD,
945 &action->thread_flags)) {
946 __set_current_state(TASK_RUNNING);
947 return 0;
948 }
949 __set_current_state(TASK_RUNNING);
950 return -1;
951 }
952
953 if (test_and_clear_bit(IRQTF_RUNTHREAD,
954 &action->thread_flags)) {
955 __set_current_state(TASK_RUNNING);
956 return 0;
957 }
958 schedule();
959 }
960}
961
962/*
963 * Oneshot interrupts keep the irq line masked until the threaded
964 * handler finished. unmask if the interrupt has not been disabled and
965 * is marked MASKED.
966 */
967static void irq_finalize_oneshot(struct irq_desc *desc,
968 struct irqaction *action)
969{
970 if (!(desc->istate & IRQS_ONESHOT) ||
971 action->handler == irq_forced_secondary_handler)
972 return;
973again:
974 chip_bus_lock(desc);
975 raw_spin_lock_irq(&desc->lock);
976
977 /*
978 * Implausible though it may be we need to protect us against
979 * the following scenario:
980 *
981 * The thread is faster done than the hard interrupt handler
982 * on the other CPU. If we unmask the irq line then the
983 * interrupt can come in again and masks the line, leaves due
984 * to IRQS_INPROGRESS and the irq line is masked forever.
985 *
986 * This also serializes the state of shared oneshot handlers
987 * versus "desc->threads_onehsot |= action->thread_mask;" in
988 * irq_wake_thread(). See the comment there which explains the
989 * serialization.
990 */
991 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
992 raw_spin_unlock_irq(&desc->lock);
993 chip_bus_sync_unlock(desc);
994 cpu_relax();
995 goto again;
996 }
997
998 /*
999 * Now check again, whether the thread should run. Otherwise
1000 * we would clear the threads_oneshot bit of this thread which
1001 * was just set.
1002 */
1003 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1004 goto out_unlock;
1005
1006 desc->threads_oneshot &= ~action->thread_mask;
1007
1008 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1009 irqd_irq_masked(&desc->irq_data))
1010 unmask_threaded_irq(desc);
1011
1012out_unlock:
1013 raw_spin_unlock_irq(&desc->lock);
1014 chip_bus_sync_unlock(desc);
1015}
1016
1017#ifdef CONFIG_SMP
1018/*
1019 * Check whether we need to change the affinity of the interrupt thread.
1020 */
1021static void
1022irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1023{
1024 cpumask_var_t mask;
1025 bool valid = true;
1026
1027 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1028 return;
1029
1030 /*
1031 * In case we are out of memory we set IRQTF_AFFINITY again and
1032 * try again next time
1033 */
1034 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1035 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1036 return;
1037 }
1038
1039 raw_spin_lock_irq(&desc->lock);
1040 /*
1041 * This code is triggered unconditionally. Check the affinity
1042 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1043 */
1044 if (cpumask_available(desc->irq_common_data.affinity)) {
1045 const struct cpumask *m;
1046
1047 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1048 cpumask_copy(mask, m);
1049 } else {
1050 valid = false;
1051 }
1052 raw_spin_unlock_irq(&desc->lock);
1053
1054 if (valid)
1055 set_cpus_allowed_ptr(current, mask);
1056 free_cpumask_var(mask);
1057}
1058#else
1059static inline void
1060irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1061#endif
1062
1063/*
1064 * Interrupts which are not explicitly requested as threaded
1065 * interrupts rely on the implicit bh/preempt disable of the hard irq
1066 * context. So we need to disable bh here to avoid deadlocks and other
1067 * side effects.
1068 */
1069static irqreturn_t
1070irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1071{
1072 irqreturn_t ret;
1073
1074 local_bh_disable();
1075 ret = action->thread_fn(action->irq, action->dev_id);
1076 if (ret == IRQ_HANDLED)
1077 atomic_inc(&desc->threads_handled);
1078
1079 irq_finalize_oneshot(desc, action);
1080 local_bh_enable();
1081 return ret;
1082}
1083
1084/*
1085 * Interrupts explicitly requested as threaded interrupts want to be
1086 * preemtible - many of them need to sleep and wait for slow busses to
1087 * complete.
1088 */
1089static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1090 struct irqaction *action)
1091{
1092 irqreturn_t ret;
1093
1094 ret = action->thread_fn(action->irq, action->dev_id);
1095 if (ret == IRQ_HANDLED)
1096 atomic_inc(&desc->threads_handled);
1097
1098 irq_finalize_oneshot(desc, action);
1099 return ret;
1100}
1101
1102static void wake_threads_waitq(struct irq_desc *desc)
1103{
1104 if (atomic_dec_and_test(&desc->threads_active))
1105 wake_up(&desc->wait_for_threads);
1106}
1107
1108static void irq_thread_dtor(struct callback_head *unused)
1109{
1110 struct task_struct *tsk = current;
1111 struct irq_desc *desc;
1112 struct irqaction *action;
1113
1114 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1115 return;
1116
1117 action = kthread_data(tsk);
1118
1119 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1120 tsk->comm, tsk->pid, action->irq);
1121
1122
1123 desc = irq_to_desc(action->irq);
1124 /*
1125 * If IRQTF_RUNTHREAD is set, we need to decrement
1126 * desc->threads_active and wake possible waiters.
1127 */
1128 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1129 wake_threads_waitq(desc);
1130
1131 /* Prevent a stale desc->threads_oneshot */
1132 irq_finalize_oneshot(desc, action);
1133}
1134
1135static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1136{
1137 struct irqaction *secondary = action->secondary;
1138
1139 if (WARN_ON_ONCE(!secondary))
1140 return;
1141
1142 raw_spin_lock_irq(&desc->lock);
1143 __irq_wake_thread(desc, secondary);
1144 raw_spin_unlock_irq(&desc->lock);
1145}
1146
1147/*
1148 * Interrupt handler thread
1149 */
1150static int irq_thread(void *data)
1151{
1152 struct callback_head on_exit_work;
1153 struct irqaction *action = data;
1154 struct irq_desc *desc = irq_to_desc(action->irq);
1155 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1156 struct irqaction *action);
1157
1158 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1159 &action->thread_flags))
1160 handler_fn = irq_forced_thread_fn;
1161 else
1162 handler_fn = irq_thread_fn;
1163
1164 init_task_work(&on_exit_work, irq_thread_dtor);
1165 task_work_add(current, &on_exit_work, false);
1166
1167 irq_thread_check_affinity(desc, action);
1168
1169 while (!irq_wait_for_interrupt(action)) {
1170 irqreturn_t action_ret;
1171
1172 irq_thread_check_affinity(desc, action);
1173
1174 action_ret = handler_fn(desc, action);
1175 if (action_ret == IRQ_WAKE_THREAD)
1176 irq_wake_secondary(desc, action);
1177
1178 wake_threads_waitq(desc);
1179 }
1180
1181 /*
1182 * This is the regular exit path. __free_irq() is stopping the
1183 * thread via kthread_stop() after calling
1184 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1185 * oneshot mask bit can be set.
1186 */
1187 task_work_cancel(current, irq_thread_dtor);
1188 return 0;
1189}
1190
1191/**
1192 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1193 * @irq: Interrupt line
1194 * @dev_id: Device identity for which the thread should be woken
1195 *
1196 */
1197void irq_wake_thread(unsigned int irq, void *dev_id)
1198{
1199 struct irq_desc *desc = irq_to_desc(irq);
1200 struct irqaction *action;
1201 unsigned long flags;
1202
1203 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1204 return;
1205
1206 raw_spin_lock_irqsave(&desc->lock, flags);
1207 for_each_action_of_desc(desc, action) {
1208 if (action->dev_id == dev_id) {
1209 if (action->thread)
1210 __irq_wake_thread(desc, action);
1211 break;
1212 }
1213 }
1214 raw_spin_unlock_irqrestore(&desc->lock, flags);
1215}
1216EXPORT_SYMBOL_GPL(irq_wake_thread);
1217
1218static int irq_setup_forced_threading(struct irqaction *new)
1219{
1220 if (!force_irqthreads)
1221 return 0;
1222 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1223 return 0;
1224
1225 /*
1226 * No further action required for interrupts which are requested as
1227 * threaded interrupts already
1228 */
1229 if (new->handler == irq_default_primary_handler)
1230 return 0;
1231
1232 new->flags |= IRQF_ONESHOT;
1233
1234 /*
1235 * Handle the case where we have a real primary handler and a
1236 * thread handler. We force thread them as well by creating a
1237 * secondary action.
1238 */
1239 if (new->handler && new->thread_fn) {
1240 /* Allocate the secondary action */
1241 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1242 if (!new->secondary)
1243 return -ENOMEM;
1244 new->secondary->handler = irq_forced_secondary_handler;
1245 new->secondary->thread_fn = new->thread_fn;
1246 new->secondary->dev_id = new->dev_id;
1247 new->secondary->irq = new->irq;
1248 new->secondary->name = new->name;
1249 }
1250 /* Deal with the primary handler */
1251 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1252 new->thread_fn = new->handler;
1253 new->handler = irq_default_primary_handler;
1254 return 0;
1255}
1256
1257static int irq_request_resources(struct irq_desc *desc)
1258{
1259 struct irq_data *d = &desc->irq_data;
1260 struct irq_chip *c = d->chip;
1261
1262 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1263}
1264
1265static void irq_release_resources(struct irq_desc *desc)
1266{
1267 struct irq_data *d = &desc->irq_data;
1268 struct irq_chip *c = d->chip;
1269
1270 if (c->irq_release_resources)
1271 c->irq_release_resources(d);
1272}
1273
1274static bool irq_supports_nmi(struct irq_desc *desc)
1275{
1276 struct irq_data *d = irq_desc_get_irq_data(desc);
1277
1278#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1279 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1280 if (d->parent_data)
1281 return false;
1282#endif
1283 /* Don't support NMIs for chips behind a slow bus */
1284 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1285 return false;
1286
1287 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1288}
1289
1290static int irq_nmi_setup(struct irq_desc *desc)
1291{
1292 struct irq_data *d = irq_desc_get_irq_data(desc);
1293 struct irq_chip *c = d->chip;
1294
1295 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1296}
1297
1298static void irq_nmi_teardown(struct irq_desc *desc)
1299{
1300 struct irq_data *d = irq_desc_get_irq_data(desc);
1301 struct irq_chip *c = d->chip;
1302
1303 if (c->irq_nmi_teardown)
1304 c->irq_nmi_teardown(d);
1305}
1306
1307static int
1308setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1309{
1310 struct task_struct *t;
1311
1312 if (!secondary) {
1313 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1314 new->name);
1315 } else {
1316 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1317 new->name);
1318 }
1319
1320 if (IS_ERR(t))
1321 return PTR_ERR(t);
1322
1323 sched_set_fifo(t);
1324
1325 /*
1326 * We keep the reference to the task struct even if
1327 * the thread dies to avoid that the interrupt code
1328 * references an already freed task_struct.
1329 */
1330 new->thread = get_task_struct(t);
1331 /*
1332 * Tell the thread to set its affinity. This is
1333 * important for shared interrupt handlers as we do
1334 * not invoke setup_affinity() for the secondary
1335 * handlers as everything is already set up. Even for
1336 * interrupts marked with IRQF_NO_BALANCE this is
1337 * correct as we want the thread to move to the cpu(s)
1338 * on which the requesting code placed the interrupt.
1339 */
1340 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1341 return 0;
1342}
1343
1344/*
1345 * Internal function to register an irqaction - typically used to
1346 * allocate special interrupts that are part of the architecture.
1347 *
1348 * Locking rules:
1349 *
1350 * desc->request_mutex Provides serialization against a concurrent free_irq()
1351 * chip_bus_lock Provides serialization for slow bus operations
1352 * desc->lock Provides serialization against hard interrupts
1353 *
1354 * chip_bus_lock and desc->lock are sufficient for all other management and
1355 * interrupt related functions. desc->request_mutex solely serializes
1356 * request/free_irq().
1357 */
1358static int
1359__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1360{
1361 struct irqaction *old, **old_ptr;
1362 unsigned long flags, thread_mask = 0;
1363 int ret, nested, shared = 0;
1364
1365 if (!desc)
1366 return -EINVAL;
1367
1368 if (desc->irq_data.chip == &no_irq_chip)
1369 return -ENOSYS;
1370 if (!try_module_get(desc->owner))
1371 return -ENODEV;
1372
1373 new->irq = irq;
1374
1375 /*
1376 * If the trigger type is not specified by the caller,
1377 * then use the default for this interrupt.
1378 */
1379 if (!(new->flags & IRQF_TRIGGER_MASK))
1380 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1381
1382 /*
1383 * Check whether the interrupt nests into another interrupt
1384 * thread.
1385 */
1386 nested = irq_settings_is_nested_thread(desc);
1387 if (nested) {
1388 if (!new->thread_fn) {
1389 ret = -EINVAL;
1390 goto out_mput;
1391 }
1392 /*
1393 * Replace the primary handler which was provided from
1394 * the driver for non nested interrupt handling by the
1395 * dummy function which warns when called.
1396 */
1397 new->handler = irq_nested_primary_handler;
1398 } else {
1399 if (irq_settings_can_thread(desc)) {
1400 ret = irq_setup_forced_threading(new);
1401 if (ret)
1402 goto out_mput;
1403 }
1404 }
1405
1406 /*
1407 * Create a handler thread when a thread function is supplied
1408 * and the interrupt does not nest into another interrupt
1409 * thread.
1410 */
1411 if (new->thread_fn && !nested) {
1412 ret = setup_irq_thread(new, irq, false);
1413 if (ret)
1414 goto out_mput;
1415 if (new->secondary) {
1416 ret = setup_irq_thread(new->secondary, irq, true);
1417 if (ret)
1418 goto out_thread;
1419 }
1420 }
1421
1422 /*
1423 * Drivers are often written to work w/o knowledge about the
1424 * underlying irq chip implementation, so a request for a
1425 * threaded irq without a primary hard irq context handler
1426 * requires the ONESHOT flag to be set. Some irq chips like
1427 * MSI based interrupts are per se one shot safe. Check the
1428 * chip flags, so we can avoid the unmask dance at the end of
1429 * the threaded handler for those.
1430 */
1431 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1432 new->flags &= ~IRQF_ONESHOT;
1433
1434 /*
1435 * Protects against a concurrent __free_irq() call which might wait
1436 * for synchronize_hardirq() to complete without holding the optional
1437 * chip bus lock and desc->lock. Also protects against handing out
1438 * a recycled oneshot thread_mask bit while it's still in use by
1439 * its previous owner.
1440 */
1441 mutex_lock(&desc->request_mutex);
1442
1443 /*
1444 * Acquire bus lock as the irq_request_resources() callback below
1445 * might rely on the serialization or the magic power management
1446 * functions which are abusing the irq_bus_lock() callback,
1447 */
1448 chip_bus_lock(desc);
1449
1450 /* First installed action requests resources. */
1451 if (!desc->action) {
1452 ret = irq_request_resources(desc);
1453 if (ret) {
1454 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1455 new->name, irq, desc->irq_data.chip->name);
1456 goto out_bus_unlock;
1457 }
1458 }
1459
1460 /*
1461 * The following block of code has to be executed atomically
1462 * protected against a concurrent interrupt and any of the other
1463 * management calls which are not serialized via
1464 * desc->request_mutex or the optional bus lock.
1465 */
1466 raw_spin_lock_irqsave(&desc->lock, flags);
1467 old_ptr = &desc->action;
1468 old = *old_ptr;
1469 if (old) {
1470 /*
1471 * Can't share interrupts unless both agree to and are
1472 * the same type (level, edge, polarity). So both flag
1473 * fields must have IRQF_SHARED set and the bits which
1474 * set the trigger type must match. Also all must
1475 * agree on ONESHOT.
1476 * Interrupt lines used for NMIs cannot be shared.
1477 */
1478 unsigned int oldtype;
1479
1480 if (desc->istate & IRQS_NMI) {
1481 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1482 new->name, irq, desc->irq_data.chip->name);
1483 ret = -EINVAL;
1484 goto out_unlock;
1485 }
1486
1487 /*
1488 * If nobody did set the configuration before, inherit
1489 * the one provided by the requester.
1490 */
1491 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1492 oldtype = irqd_get_trigger_type(&desc->irq_data);
1493 } else {
1494 oldtype = new->flags & IRQF_TRIGGER_MASK;
1495 irqd_set_trigger_type(&desc->irq_data, oldtype);
1496 }
1497
1498 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1499 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1500 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1501 goto mismatch;
1502
1503 /* All handlers must agree on per-cpuness */
1504 if ((old->flags & IRQF_PERCPU) !=
1505 (new->flags & IRQF_PERCPU))
1506 goto mismatch;
1507
1508 /* add new interrupt at end of irq queue */
1509 do {
1510 /*
1511 * Or all existing action->thread_mask bits,
1512 * so we can find the next zero bit for this
1513 * new action.
1514 */
1515 thread_mask |= old->thread_mask;
1516 old_ptr = &old->next;
1517 old = *old_ptr;
1518 } while (old);
1519 shared = 1;
1520 }
1521
1522 /*
1523 * Setup the thread mask for this irqaction for ONESHOT. For
1524 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1525 * conditional in irq_wake_thread().
1526 */
1527 if (new->flags & IRQF_ONESHOT) {
1528 /*
1529 * Unlikely to have 32 resp 64 irqs sharing one line,
1530 * but who knows.
1531 */
1532 if (thread_mask == ~0UL) {
1533 ret = -EBUSY;
1534 goto out_unlock;
1535 }
1536 /*
1537 * The thread_mask for the action is or'ed to
1538 * desc->thread_active to indicate that the
1539 * IRQF_ONESHOT thread handler has been woken, but not
1540 * yet finished. The bit is cleared when a thread
1541 * completes. When all threads of a shared interrupt
1542 * line have completed desc->threads_active becomes
1543 * zero and the interrupt line is unmasked. See
1544 * handle.c:irq_wake_thread() for further information.
1545 *
1546 * If no thread is woken by primary (hard irq context)
1547 * interrupt handlers, then desc->threads_active is
1548 * also checked for zero to unmask the irq line in the
1549 * affected hard irq flow handlers
1550 * (handle_[fasteoi|level]_irq).
1551 *
1552 * The new action gets the first zero bit of
1553 * thread_mask assigned. See the loop above which or's
1554 * all existing action->thread_mask bits.
1555 */
1556 new->thread_mask = 1UL << ffz(thread_mask);
1557
1558 } else if (new->handler == irq_default_primary_handler &&
1559 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1560 /*
1561 * The interrupt was requested with handler = NULL, so
1562 * we use the default primary handler for it. But it
1563 * does not have the oneshot flag set. In combination
1564 * with level interrupts this is deadly, because the
1565 * default primary handler just wakes the thread, then
1566 * the irq lines is reenabled, but the device still
1567 * has the level irq asserted. Rinse and repeat....
1568 *
1569 * While this works for edge type interrupts, we play
1570 * it safe and reject unconditionally because we can't
1571 * say for sure which type this interrupt really
1572 * has. The type flags are unreliable as the
1573 * underlying chip implementation can override them.
1574 */
1575 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1576 new->name, irq);
1577 ret = -EINVAL;
1578 goto out_unlock;
1579 }
1580
1581 if (!shared) {
1582 init_waitqueue_head(&desc->wait_for_threads);
1583
1584 /* Setup the type (level, edge polarity) if configured: */
1585 if (new->flags & IRQF_TRIGGER_MASK) {
1586 ret = __irq_set_trigger(desc,
1587 new->flags & IRQF_TRIGGER_MASK);
1588
1589 if (ret)
1590 goto out_unlock;
1591 }
1592
1593 /*
1594 * Activate the interrupt. That activation must happen
1595 * independently of IRQ_NOAUTOEN. request_irq() can fail
1596 * and the callers are supposed to handle
1597 * that. enable_irq() of an interrupt requested with
1598 * IRQ_NOAUTOEN is not supposed to fail. The activation
1599 * keeps it in shutdown mode, it merily associates
1600 * resources if necessary and if that's not possible it
1601 * fails. Interrupts which are in managed shutdown mode
1602 * will simply ignore that activation request.
1603 */
1604 ret = irq_activate(desc);
1605 if (ret)
1606 goto out_unlock;
1607
1608 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1609 IRQS_ONESHOT | IRQS_WAITING);
1610 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1611
1612 if (new->flags & IRQF_PERCPU) {
1613 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1614 irq_settings_set_per_cpu(desc);
1615 }
1616
1617 if (new->flags & IRQF_ONESHOT)
1618 desc->istate |= IRQS_ONESHOT;
1619
1620 /* Exclude IRQ from balancing if requested */
1621 if (new->flags & IRQF_NOBALANCING) {
1622 irq_settings_set_no_balancing(desc);
1623 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1624 }
1625
1626 if (irq_settings_can_autoenable(desc)) {
1627 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1628 } else {
1629 /*
1630 * Shared interrupts do not go well with disabling
1631 * auto enable. The sharing interrupt might request
1632 * it while it's still disabled and then wait for
1633 * interrupts forever.
1634 */
1635 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1636 /* Undo nested disables: */
1637 desc->depth = 1;
1638 }
1639
1640 } else if (new->flags & IRQF_TRIGGER_MASK) {
1641 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1642 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1643
1644 if (nmsk != omsk)
1645 /* hope the handler works with current trigger mode */
1646 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1647 irq, omsk, nmsk);
1648 }
1649
1650 *old_ptr = new;
1651
1652 irq_pm_install_action(desc, new);
1653
1654 /* Reset broken irq detection when installing new handler */
1655 desc->irq_count = 0;
1656 desc->irqs_unhandled = 0;
1657
1658 /*
1659 * Check whether we disabled the irq via the spurious handler
1660 * before. Reenable it and give it another chance.
1661 */
1662 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1663 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1664 __enable_irq(desc);
1665 }
1666
1667 raw_spin_unlock_irqrestore(&desc->lock, flags);
1668 chip_bus_sync_unlock(desc);
1669 mutex_unlock(&desc->request_mutex);
1670
1671 irq_setup_timings(desc, new);
1672
1673 /*
1674 * Strictly no need to wake it up, but hung_task complains
1675 * when no hard interrupt wakes the thread up.
1676 */
1677 if (new->thread)
1678 wake_up_process(new->thread);
1679 if (new->secondary)
1680 wake_up_process(new->secondary->thread);
1681
1682 register_irq_proc(irq, desc);
1683 new->dir = NULL;
1684 register_handler_proc(irq, new);
1685 return 0;
1686
1687mismatch:
1688 if (!(new->flags & IRQF_PROBE_SHARED)) {
1689 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1690 irq, new->flags, new->name, old->flags, old->name);
1691#ifdef CONFIG_DEBUG_SHIRQ
1692 dump_stack();
1693#endif
1694 }
1695 ret = -EBUSY;
1696
1697out_unlock:
1698 raw_spin_unlock_irqrestore(&desc->lock, flags);
1699
1700 if (!desc->action)
1701 irq_release_resources(desc);
1702out_bus_unlock:
1703 chip_bus_sync_unlock(desc);
1704 mutex_unlock(&desc->request_mutex);
1705
1706out_thread:
1707 if (new->thread) {
1708 struct task_struct *t = new->thread;
1709
1710 new->thread = NULL;
1711 kthread_stop(t);
1712 put_task_struct(t);
1713 }
1714 if (new->secondary && new->secondary->thread) {
1715 struct task_struct *t = new->secondary->thread;
1716
1717 new->secondary->thread = NULL;
1718 kthread_stop(t);
1719 put_task_struct(t);
1720 }
1721out_mput:
1722 module_put(desc->owner);
1723 return ret;
1724}
1725
1726/*
1727 * Internal function to unregister an irqaction - used to free
1728 * regular and special interrupts that are part of the architecture.
1729 */
1730static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1731{
1732 unsigned irq = desc->irq_data.irq;
1733 struct irqaction *action, **action_ptr;
1734 unsigned long flags;
1735
1736 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1737
1738 mutex_lock(&desc->request_mutex);
1739 chip_bus_lock(desc);
1740 raw_spin_lock_irqsave(&desc->lock, flags);
1741
1742 /*
1743 * There can be multiple actions per IRQ descriptor, find the right
1744 * one based on the dev_id:
1745 */
1746 action_ptr = &desc->action;
1747 for (;;) {
1748 action = *action_ptr;
1749
1750 if (!action) {
1751 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1752 raw_spin_unlock_irqrestore(&desc->lock, flags);
1753 chip_bus_sync_unlock(desc);
1754 mutex_unlock(&desc->request_mutex);
1755 return NULL;
1756 }
1757
1758 if (action->dev_id == dev_id)
1759 break;
1760 action_ptr = &action->next;
1761 }
1762
1763 /* Found it - now remove it from the list of entries: */
1764 *action_ptr = action->next;
1765
1766 irq_pm_remove_action(desc, action);
1767
1768 /* If this was the last handler, shut down the IRQ line: */
1769 if (!desc->action) {
1770 irq_settings_clr_disable_unlazy(desc);
1771 /* Only shutdown. Deactivate after synchronize_hardirq() */
1772 irq_shutdown(desc);
1773 }
1774
1775#ifdef CONFIG_SMP
1776 /* make sure affinity_hint is cleaned up */
1777 if (WARN_ON_ONCE(desc->affinity_hint))
1778 desc->affinity_hint = NULL;
1779#endif
1780
1781 raw_spin_unlock_irqrestore(&desc->lock, flags);
1782 /*
1783 * Drop bus_lock here so the changes which were done in the chip
1784 * callbacks above are synced out to the irq chips which hang
1785 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1786 *
1787 * Aside of that the bus_lock can also be taken from the threaded
1788 * handler in irq_finalize_oneshot() which results in a deadlock
1789 * because kthread_stop() would wait forever for the thread to
1790 * complete, which is blocked on the bus lock.
1791 *
1792 * The still held desc->request_mutex() protects against a
1793 * concurrent request_irq() of this irq so the release of resources
1794 * and timing data is properly serialized.
1795 */
1796 chip_bus_sync_unlock(desc);
1797
1798 unregister_handler_proc(irq, action);
1799
1800 /*
1801 * Make sure it's not being used on another CPU and if the chip
1802 * supports it also make sure that there is no (not yet serviced)
1803 * interrupt in flight at the hardware level.
1804 */
1805 __synchronize_hardirq(desc, true);
1806
1807#ifdef CONFIG_DEBUG_SHIRQ
1808 /*
1809 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1810 * event to happen even now it's being freed, so let's make sure that
1811 * is so by doing an extra call to the handler ....
1812 *
1813 * ( We do this after actually deregistering it, to make sure that a
1814 * 'real' IRQ doesn't run in parallel with our fake. )
1815 */
1816 if (action->flags & IRQF_SHARED) {
1817 local_irq_save(flags);
1818 action->handler(irq, dev_id);
1819 local_irq_restore(flags);
1820 }
1821#endif
1822
1823 /*
1824 * The action has already been removed above, but the thread writes
1825 * its oneshot mask bit when it completes. Though request_mutex is
1826 * held across this which prevents __setup_irq() from handing out
1827 * the same bit to a newly requested action.
1828 */
1829 if (action->thread) {
1830 kthread_stop(action->thread);
1831 put_task_struct(action->thread);
1832 if (action->secondary && action->secondary->thread) {
1833 kthread_stop(action->secondary->thread);
1834 put_task_struct(action->secondary->thread);
1835 }
1836 }
1837
1838 /* Last action releases resources */
1839 if (!desc->action) {
1840 /*
1841 * Reaquire bus lock as irq_release_resources() might
1842 * require it to deallocate resources over the slow bus.
1843 */
1844 chip_bus_lock(desc);
1845 /*
1846 * There is no interrupt on the fly anymore. Deactivate it
1847 * completely.
1848 */
1849 raw_spin_lock_irqsave(&desc->lock, flags);
1850 irq_domain_deactivate_irq(&desc->irq_data);
1851 raw_spin_unlock_irqrestore(&desc->lock, flags);
1852
1853 irq_release_resources(desc);
1854 chip_bus_sync_unlock(desc);
1855 irq_remove_timings(desc);
1856 }
1857
1858 mutex_unlock(&desc->request_mutex);
1859
1860 irq_chip_pm_put(&desc->irq_data);
1861 module_put(desc->owner);
1862 kfree(action->secondary);
1863 return action;
1864}
1865
1866/**
1867 * free_irq - free an interrupt allocated with request_irq
1868 * @irq: Interrupt line to free
1869 * @dev_id: Device identity to free
1870 *
1871 * Remove an interrupt handler. The handler is removed and if the
1872 * interrupt line is no longer in use by any driver it is disabled.
1873 * On a shared IRQ the caller must ensure the interrupt is disabled
1874 * on the card it drives before calling this function. The function
1875 * does not return until any executing interrupts for this IRQ
1876 * have completed.
1877 *
1878 * This function must not be called from interrupt context.
1879 *
1880 * Returns the devname argument passed to request_irq.
1881 */
1882const void *free_irq(unsigned int irq, void *dev_id)
1883{
1884 struct irq_desc *desc = irq_to_desc(irq);
1885 struct irqaction *action;
1886 const char *devname;
1887
1888 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1889 return NULL;
1890
1891#ifdef CONFIG_SMP
1892 if (WARN_ON(desc->affinity_notify))
1893 desc->affinity_notify = NULL;
1894#endif
1895
1896 action = __free_irq(desc, dev_id);
1897
1898 if (!action)
1899 return NULL;
1900
1901 devname = action->name;
1902 kfree(action);
1903 return devname;
1904}
1905EXPORT_SYMBOL(free_irq);
1906
1907/* This function must be called with desc->lock held */
1908static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1909{
1910 const char *devname = NULL;
1911
1912 desc->istate &= ~IRQS_NMI;
1913
1914 if (!WARN_ON(desc->action == NULL)) {
1915 irq_pm_remove_action(desc, desc->action);
1916 devname = desc->action->name;
1917 unregister_handler_proc(irq, desc->action);
1918
1919 kfree(desc->action);
1920 desc->action = NULL;
1921 }
1922
1923 irq_settings_clr_disable_unlazy(desc);
1924 irq_shutdown_and_deactivate(desc);
1925
1926 irq_release_resources(desc);
1927
1928 irq_chip_pm_put(&desc->irq_data);
1929 module_put(desc->owner);
1930
1931 return devname;
1932}
1933
1934const void *free_nmi(unsigned int irq, void *dev_id)
1935{
1936 struct irq_desc *desc = irq_to_desc(irq);
1937 unsigned long flags;
1938 const void *devname;
1939
1940 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
1941 return NULL;
1942
1943 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1944 return NULL;
1945
1946 /* NMI still enabled */
1947 if (WARN_ON(desc->depth == 0))
1948 disable_nmi_nosync(irq);
1949
1950 raw_spin_lock_irqsave(&desc->lock, flags);
1951
1952 irq_nmi_teardown(desc);
1953 devname = __cleanup_nmi(irq, desc);
1954
1955 raw_spin_unlock_irqrestore(&desc->lock, flags);
1956
1957 return devname;
1958}
1959
1960/**
1961 * request_threaded_irq - allocate an interrupt line
1962 * @irq: Interrupt line to allocate
1963 * @handler: Function to be called when the IRQ occurs.
1964 * Primary handler for threaded interrupts
1965 * If NULL and thread_fn != NULL the default
1966 * primary handler is installed
1967 * @thread_fn: Function called from the irq handler thread
1968 * If NULL, no irq thread is created
1969 * @irqflags: Interrupt type flags
1970 * @devname: An ascii name for the claiming device
1971 * @dev_id: A cookie passed back to the handler function
1972 *
1973 * This call allocates interrupt resources and enables the
1974 * interrupt line and IRQ handling. From the point this
1975 * call is made your handler function may be invoked. Since
1976 * your handler function must clear any interrupt the board
1977 * raises, you must take care both to initialise your hardware
1978 * and to set up the interrupt handler in the right order.
1979 *
1980 * If you want to set up a threaded irq handler for your device
1981 * then you need to supply @handler and @thread_fn. @handler is
1982 * still called in hard interrupt context and has to check
1983 * whether the interrupt originates from the device. If yes it
1984 * needs to disable the interrupt on the device and return
1985 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1986 * @thread_fn. This split handler design is necessary to support
1987 * shared interrupts.
1988 *
1989 * Dev_id must be globally unique. Normally the address of the
1990 * device data structure is used as the cookie. Since the handler
1991 * receives this value it makes sense to use it.
1992 *
1993 * If your interrupt is shared you must pass a non NULL dev_id
1994 * as this is required when freeing the interrupt.
1995 *
1996 * Flags:
1997 *
1998 * IRQF_SHARED Interrupt is shared
1999 * IRQF_TRIGGER_* Specify active edge(s) or level
2000 *
2001 */
2002int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2003 irq_handler_t thread_fn, unsigned long irqflags,
2004 const char *devname, void *dev_id)
2005{
2006 struct irqaction *action;
2007 struct irq_desc *desc;
2008 int retval;
2009
2010 if (irq == IRQ_NOTCONNECTED)
2011 return -ENOTCONN;
2012
2013 /*
2014 * Sanity-check: shared interrupts must pass in a real dev-ID,
2015 * otherwise we'll have trouble later trying to figure out
2016 * which interrupt is which (messes up the interrupt freeing
2017 * logic etc).
2018 *
2019 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2020 * it cannot be set along with IRQF_NO_SUSPEND.
2021 */
2022 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2023 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2024 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2025 return -EINVAL;
2026
2027 desc = irq_to_desc(irq);
2028 if (!desc)
2029 return -EINVAL;
2030
2031 if (!irq_settings_can_request(desc) ||
2032 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2033 return -EINVAL;
2034
2035 if (!handler) {
2036 if (!thread_fn)
2037 return -EINVAL;
2038 handler = irq_default_primary_handler;
2039 }
2040
2041 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2042 if (!action)
2043 return -ENOMEM;
2044
2045 action->handler = handler;
2046 action->thread_fn = thread_fn;
2047 action->flags = irqflags;
2048 action->name = devname;
2049 action->dev_id = dev_id;
2050
2051 retval = irq_chip_pm_get(&desc->irq_data);
2052 if (retval < 0) {
2053 kfree(action);
2054 return retval;
2055 }
2056
2057 retval = __setup_irq(irq, desc, action);
2058
2059 if (retval) {
2060 irq_chip_pm_put(&desc->irq_data);
2061 kfree(action->secondary);
2062 kfree(action);
2063 }
2064
2065#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2066 if (!retval && (irqflags & IRQF_SHARED)) {
2067 /*
2068 * It's a shared IRQ -- the driver ought to be prepared for it
2069 * to happen immediately, so let's make sure....
2070 * We disable the irq to make sure that a 'real' IRQ doesn't
2071 * run in parallel with our fake.
2072 */
2073 unsigned long flags;
2074
2075 disable_irq(irq);
2076 local_irq_save(flags);
2077
2078 handler(irq, dev_id);
2079
2080 local_irq_restore(flags);
2081 enable_irq(irq);
2082 }
2083#endif
2084 return retval;
2085}
2086EXPORT_SYMBOL(request_threaded_irq);
2087
2088/**
2089 * request_any_context_irq - allocate an interrupt line
2090 * @irq: Interrupt line to allocate
2091 * @handler: Function to be called when the IRQ occurs.
2092 * Threaded handler for threaded interrupts.
2093 * @flags: Interrupt type flags
2094 * @name: An ascii name for the claiming device
2095 * @dev_id: A cookie passed back to the handler function
2096 *
2097 * This call allocates interrupt resources and enables the
2098 * interrupt line and IRQ handling. It selects either a
2099 * hardirq or threaded handling method depending on the
2100 * context.
2101 *
2102 * On failure, it returns a negative value. On success,
2103 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2104 */
2105int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2106 unsigned long flags, const char *name, void *dev_id)
2107{
2108 struct irq_desc *desc;
2109 int ret;
2110
2111 if (irq == IRQ_NOTCONNECTED)
2112 return -ENOTCONN;
2113
2114 desc = irq_to_desc(irq);
2115 if (!desc)
2116 return -EINVAL;
2117
2118 if (irq_settings_is_nested_thread(desc)) {
2119 ret = request_threaded_irq(irq, NULL, handler,
2120 flags, name, dev_id);
2121 return !ret ? IRQC_IS_NESTED : ret;
2122 }
2123
2124 ret = request_irq(irq, handler, flags, name, dev_id);
2125 return !ret ? IRQC_IS_HARDIRQ : ret;
2126}
2127EXPORT_SYMBOL_GPL(request_any_context_irq);
2128
2129/**
2130 * request_nmi - allocate an interrupt line for NMI delivery
2131 * @irq: Interrupt line to allocate
2132 * @handler: Function to be called when the IRQ occurs.
2133 * Threaded handler for threaded interrupts.
2134 * @irqflags: Interrupt type flags
2135 * @name: An ascii name for the claiming device
2136 * @dev_id: A cookie passed back to the handler function
2137 *
2138 * This call allocates interrupt resources and enables the
2139 * interrupt line and IRQ handling. It sets up the IRQ line
2140 * to be handled as an NMI.
2141 *
2142 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2143 * cannot be threaded.
2144 *
2145 * Interrupt lines requested for NMI delivering must produce per cpu
2146 * interrupts and have auto enabling setting disabled.
2147 *
2148 * Dev_id must be globally unique. Normally the address of the
2149 * device data structure is used as the cookie. Since the handler
2150 * receives this value it makes sense to use it.
2151 *
2152 * If the interrupt line cannot be used to deliver NMIs, function
2153 * will fail and return a negative value.
2154 */
2155int request_nmi(unsigned int irq, irq_handler_t handler,
2156 unsigned long irqflags, const char *name, void *dev_id)
2157{
2158 struct irqaction *action;
2159 struct irq_desc *desc;
2160 unsigned long flags;
2161 int retval;
2162
2163 if (irq == IRQ_NOTCONNECTED)
2164 return -ENOTCONN;
2165
2166 /* NMI cannot be shared, used for Polling */
2167 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2168 return -EINVAL;
2169
2170 if (!(irqflags & IRQF_PERCPU))
2171 return -EINVAL;
2172
2173 if (!handler)
2174 return -EINVAL;
2175
2176 desc = irq_to_desc(irq);
2177
2178 if (!desc || irq_settings_can_autoenable(desc) ||
2179 !irq_settings_can_request(desc) ||
2180 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2181 !irq_supports_nmi(desc))
2182 return -EINVAL;
2183
2184 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2185 if (!action)
2186 return -ENOMEM;
2187
2188 action->handler = handler;
2189 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2190 action->name = name;
2191 action->dev_id = dev_id;
2192
2193 retval = irq_chip_pm_get(&desc->irq_data);
2194 if (retval < 0)
2195 goto err_out;
2196
2197 retval = __setup_irq(irq, desc, action);
2198 if (retval)
2199 goto err_irq_setup;
2200
2201 raw_spin_lock_irqsave(&desc->lock, flags);
2202
2203 /* Setup NMI state */
2204 desc->istate |= IRQS_NMI;
2205 retval = irq_nmi_setup(desc);
2206 if (retval) {
2207 __cleanup_nmi(irq, desc);
2208 raw_spin_unlock_irqrestore(&desc->lock, flags);
2209 return -EINVAL;
2210 }
2211
2212 raw_spin_unlock_irqrestore(&desc->lock, flags);
2213
2214 return 0;
2215
2216err_irq_setup:
2217 irq_chip_pm_put(&desc->irq_data);
2218err_out:
2219 kfree(action);
2220
2221 return retval;
2222}
2223
2224void enable_percpu_irq(unsigned int irq, unsigned int type)
2225{
2226 unsigned int cpu = smp_processor_id();
2227 unsigned long flags;
2228 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2229
2230 if (!desc)
2231 return;
2232
2233 /*
2234 * If the trigger type is not specified by the caller, then
2235 * use the default for this interrupt.
2236 */
2237 type &= IRQ_TYPE_SENSE_MASK;
2238 if (type == IRQ_TYPE_NONE)
2239 type = irqd_get_trigger_type(&desc->irq_data);
2240
2241 if (type != IRQ_TYPE_NONE) {
2242 int ret;
2243
2244 ret = __irq_set_trigger(desc, type);
2245
2246 if (ret) {
2247 WARN(1, "failed to set type for IRQ%d\n", irq);
2248 goto out;
2249 }
2250 }
2251
2252 irq_percpu_enable(desc, cpu);
2253out:
2254 irq_put_desc_unlock(desc, flags);
2255}
2256EXPORT_SYMBOL_GPL(enable_percpu_irq);
2257
2258void enable_percpu_nmi(unsigned int irq, unsigned int type)
2259{
2260 enable_percpu_irq(irq, type);
2261}
2262
2263/**
2264 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2265 * @irq: Linux irq number to check for
2266 *
2267 * Must be called from a non migratable context. Returns the enable
2268 * state of a per cpu interrupt on the current cpu.
2269 */
2270bool irq_percpu_is_enabled(unsigned int irq)
2271{
2272 unsigned int cpu = smp_processor_id();
2273 struct irq_desc *desc;
2274 unsigned long flags;
2275 bool is_enabled;
2276
2277 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2278 if (!desc)
2279 return false;
2280
2281 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2282 irq_put_desc_unlock(desc, flags);
2283
2284 return is_enabled;
2285}
2286EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2287
2288void disable_percpu_irq(unsigned int irq)
2289{
2290 unsigned int cpu = smp_processor_id();
2291 unsigned long flags;
2292 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2293
2294 if (!desc)
2295 return;
2296
2297 irq_percpu_disable(desc, cpu);
2298 irq_put_desc_unlock(desc, flags);
2299}
2300EXPORT_SYMBOL_GPL(disable_percpu_irq);
2301
2302void disable_percpu_nmi(unsigned int irq)
2303{
2304 disable_percpu_irq(irq);
2305}
2306
2307/*
2308 * Internal function to unregister a percpu irqaction.
2309 */
2310static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2311{
2312 struct irq_desc *desc = irq_to_desc(irq);
2313 struct irqaction *action;
2314 unsigned long flags;
2315
2316 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2317
2318 if (!desc)
2319 return NULL;
2320
2321 raw_spin_lock_irqsave(&desc->lock, flags);
2322
2323 action = desc->action;
2324 if (!action || action->percpu_dev_id != dev_id) {
2325 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2326 goto bad;
2327 }
2328
2329 if (!cpumask_empty(desc->percpu_enabled)) {
2330 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2331 irq, cpumask_first(desc->percpu_enabled));
2332 goto bad;
2333 }
2334
2335 /* Found it - now remove it from the list of entries: */
2336 desc->action = NULL;
2337
2338 desc->istate &= ~IRQS_NMI;
2339
2340 raw_spin_unlock_irqrestore(&desc->lock, flags);
2341
2342 unregister_handler_proc(irq, action);
2343
2344 irq_chip_pm_put(&desc->irq_data);
2345 module_put(desc->owner);
2346 return action;
2347
2348bad:
2349 raw_spin_unlock_irqrestore(&desc->lock, flags);
2350 return NULL;
2351}
2352
2353/**
2354 * remove_percpu_irq - free a per-cpu interrupt
2355 * @irq: Interrupt line to free
2356 * @act: irqaction for the interrupt
2357 *
2358 * Used to remove interrupts statically setup by the early boot process.
2359 */
2360void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2361{
2362 struct irq_desc *desc = irq_to_desc(irq);
2363
2364 if (desc && irq_settings_is_per_cpu_devid(desc))
2365 __free_percpu_irq(irq, act->percpu_dev_id);
2366}
2367
2368/**
2369 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2370 * @irq: Interrupt line to free
2371 * @dev_id: Device identity to free
2372 *
2373 * Remove a percpu interrupt handler. The handler is removed, but
2374 * the interrupt line is not disabled. This must be done on each
2375 * CPU before calling this function. The function does not return
2376 * until any executing interrupts for this IRQ have completed.
2377 *
2378 * This function must not be called from interrupt context.
2379 */
2380void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2381{
2382 struct irq_desc *desc = irq_to_desc(irq);
2383
2384 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2385 return;
2386
2387 chip_bus_lock(desc);
2388 kfree(__free_percpu_irq(irq, dev_id));
2389 chip_bus_sync_unlock(desc);
2390}
2391EXPORT_SYMBOL_GPL(free_percpu_irq);
2392
2393void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2394{
2395 struct irq_desc *desc = irq_to_desc(irq);
2396
2397 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2398 return;
2399
2400 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2401 return;
2402
2403 kfree(__free_percpu_irq(irq, dev_id));
2404}
2405
2406/**
2407 * setup_percpu_irq - setup a per-cpu interrupt
2408 * @irq: Interrupt line to setup
2409 * @act: irqaction for the interrupt
2410 *
2411 * Used to statically setup per-cpu interrupts in the early boot process.
2412 */
2413int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2414{
2415 struct irq_desc *desc = irq_to_desc(irq);
2416 int retval;
2417
2418 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2419 return -EINVAL;
2420
2421 retval = irq_chip_pm_get(&desc->irq_data);
2422 if (retval < 0)
2423 return retval;
2424
2425 retval = __setup_irq(irq, desc, act);
2426
2427 if (retval)
2428 irq_chip_pm_put(&desc->irq_data);
2429
2430 return retval;
2431}
2432
2433/**
2434 * __request_percpu_irq - allocate a percpu interrupt line
2435 * @irq: Interrupt line to allocate
2436 * @handler: Function to be called when the IRQ occurs.
2437 * @flags: Interrupt type flags (IRQF_TIMER only)
2438 * @devname: An ascii name for the claiming device
2439 * @dev_id: A percpu cookie passed back to the handler function
2440 *
2441 * This call allocates interrupt resources and enables the
2442 * interrupt on the local CPU. If the interrupt is supposed to be
2443 * enabled on other CPUs, it has to be done on each CPU using
2444 * enable_percpu_irq().
2445 *
2446 * Dev_id must be globally unique. It is a per-cpu variable, and
2447 * the handler gets called with the interrupted CPU's instance of
2448 * that variable.
2449 */
2450int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2451 unsigned long flags, const char *devname,
2452 void __percpu *dev_id)
2453{
2454 struct irqaction *action;
2455 struct irq_desc *desc;
2456 int retval;
2457
2458 if (!dev_id)
2459 return -EINVAL;
2460
2461 desc = irq_to_desc(irq);
2462 if (!desc || !irq_settings_can_request(desc) ||
2463 !irq_settings_is_per_cpu_devid(desc))
2464 return -EINVAL;
2465
2466 if (flags && flags != IRQF_TIMER)
2467 return -EINVAL;
2468
2469 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2470 if (!action)
2471 return -ENOMEM;
2472
2473 action->handler = handler;
2474 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2475 action->name = devname;
2476 action->percpu_dev_id = dev_id;
2477
2478 retval = irq_chip_pm_get(&desc->irq_data);
2479 if (retval < 0) {
2480 kfree(action);
2481 return retval;
2482 }
2483
2484 retval = __setup_irq(irq, desc, action);
2485
2486 if (retval) {
2487 irq_chip_pm_put(&desc->irq_data);
2488 kfree(action);
2489 }
2490
2491 return retval;
2492}
2493EXPORT_SYMBOL_GPL(__request_percpu_irq);
2494
2495/**
2496 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2497 * @irq: Interrupt line to allocate
2498 * @handler: Function to be called when the IRQ occurs.
2499 * @name: An ascii name for the claiming device
2500 * @dev_id: A percpu cookie passed back to the handler function
2501 *
2502 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2503 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2504 * being enabled on the same CPU by using enable_percpu_nmi().
2505 *
2506 * Dev_id must be globally unique. It is a per-cpu variable, and
2507 * the handler gets called with the interrupted CPU's instance of
2508 * that variable.
2509 *
2510 * Interrupt lines requested for NMI delivering should have auto enabling
2511 * setting disabled.
2512 *
2513 * If the interrupt line cannot be used to deliver NMIs, function
2514 * will fail returning a negative value.
2515 */
2516int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2517 const char *name, void __percpu *dev_id)
2518{
2519 struct irqaction *action;
2520 struct irq_desc *desc;
2521 unsigned long flags;
2522 int retval;
2523
2524 if (!handler)
2525 return -EINVAL;
2526
2527 desc = irq_to_desc(irq);
2528
2529 if (!desc || !irq_settings_can_request(desc) ||
2530 !irq_settings_is_per_cpu_devid(desc) ||
2531 irq_settings_can_autoenable(desc) ||
2532 !irq_supports_nmi(desc))
2533 return -EINVAL;
2534
2535 /* The line cannot already be NMI */
2536 if (desc->istate & IRQS_NMI)
2537 return -EINVAL;
2538
2539 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2540 if (!action)
2541 return -ENOMEM;
2542
2543 action->handler = handler;
2544 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2545 | IRQF_NOBALANCING;
2546 action->name = name;
2547 action->percpu_dev_id = dev_id;
2548
2549 retval = irq_chip_pm_get(&desc->irq_data);
2550 if (retval < 0)
2551 goto err_out;
2552
2553 retval = __setup_irq(irq, desc, action);
2554 if (retval)
2555 goto err_irq_setup;
2556
2557 raw_spin_lock_irqsave(&desc->lock, flags);
2558 desc->istate |= IRQS_NMI;
2559 raw_spin_unlock_irqrestore(&desc->lock, flags);
2560
2561 return 0;
2562
2563err_irq_setup:
2564 irq_chip_pm_put(&desc->irq_data);
2565err_out:
2566 kfree(action);
2567
2568 return retval;
2569}
2570
2571/**
2572 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2573 * @irq: Interrupt line to prepare for NMI delivery
2574 *
2575 * This call prepares an interrupt line to deliver NMI on the current CPU,
2576 * before that interrupt line gets enabled with enable_percpu_nmi().
2577 *
2578 * As a CPU local operation, this should be called from non-preemptible
2579 * context.
2580 *
2581 * If the interrupt line cannot be used to deliver NMIs, function
2582 * will fail returning a negative value.
2583 */
2584int prepare_percpu_nmi(unsigned int irq)
2585{
2586 unsigned long flags;
2587 struct irq_desc *desc;
2588 int ret = 0;
2589
2590 WARN_ON(preemptible());
2591
2592 desc = irq_get_desc_lock(irq, &flags,
2593 IRQ_GET_DESC_CHECK_PERCPU);
2594 if (!desc)
2595 return -EINVAL;
2596
2597 if (WARN(!(desc->istate & IRQS_NMI),
2598 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2599 irq)) {
2600 ret = -EINVAL;
2601 goto out;
2602 }
2603
2604 ret = irq_nmi_setup(desc);
2605 if (ret) {
2606 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2607 goto out;
2608 }
2609
2610out:
2611 irq_put_desc_unlock(desc, flags);
2612 return ret;
2613}
2614
2615/**
2616 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2617 * @irq: Interrupt line from which CPU local NMI configuration should be
2618 * removed
2619 *
2620 * This call undoes the setup done by prepare_percpu_nmi().
2621 *
2622 * IRQ line should not be enabled for the current CPU.
2623 *
2624 * As a CPU local operation, this should be called from non-preemptible
2625 * context.
2626 */
2627void teardown_percpu_nmi(unsigned int irq)
2628{
2629 unsigned long flags;
2630 struct irq_desc *desc;
2631
2632 WARN_ON(preemptible());
2633
2634 desc = irq_get_desc_lock(irq, &flags,
2635 IRQ_GET_DESC_CHECK_PERCPU);
2636 if (!desc)
2637 return;
2638
2639 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2640 goto out;
2641
2642 irq_nmi_teardown(desc);
2643out:
2644 irq_put_desc_unlock(desc, flags);
2645}
2646
2647int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2648 bool *state)
2649{
2650 struct irq_chip *chip;
2651 int err = -EINVAL;
2652
2653 do {
2654 chip = irq_data_get_irq_chip(data);
2655 if (WARN_ON_ONCE(!chip))
2656 return -ENODEV;
2657 if (chip->irq_get_irqchip_state)
2658 break;
2659#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2660 data = data->parent_data;
2661#else
2662 data = NULL;
2663#endif
2664 } while (data);
2665
2666 if (data)
2667 err = chip->irq_get_irqchip_state(data, which, state);
2668 return err;
2669}
2670
2671/**
2672 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2673 * @irq: Interrupt line that is forwarded to a VM
2674 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2675 * @state: a pointer to a boolean where the state is to be storeed
2676 *
2677 * This call snapshots the internal irqchip state of an
2678 * interrupt, returning into @state the bit corresponding to
2679 * stage @which
2680 *
2681 * This function should be called with preemption disabled if the
2682 * interrupt controller has per-cpu registers.
2683 */
2684int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2685 bool *state)
2686{
2687 struct irq_desc *desc;
2688 struct irq_data *data;
2689 unsigned long flags;
2690 int err = -EINVAL;
2691
2692 desc = irq_get_desc_buslock(irq, &flags, 0);
2693 if (!desc)
2694 return err;
2695
2696 data = irq_desc_get_irq_data(desc);
2697
2698 err = __irq_get_irqchip_state(data, which, state);
2699
2700 irq_put_desc_busunlock(desc, flags);
2701 return err;
2702}
2703EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2704
2705/**
2706 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2707 * @irq: Interrupt line that is forwarded to a VM
2708 * @which: State to be restored (one of IRQCHIP_STATE_*)
2709 * @val: Value corresponding to @which
2710 *
2711 * This call sets the internal irqchip state of an interrupt,
2712 * depending on the value of @which.
2713 *
2714 * This function should be called with preemption disabled if the
2715 * interrupt controller has per-cpu registers.
2716 */
2717int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2718 bool val)
2719{
2720 struct irq_desc *desc;
2721 struct irq_data *data;
2722 struct irq_chip *chip;
2723 unsigned long flags;
2724 int err = -EINVAL;
2725
2726 desc = irq_get_desc_buslock(irq, &flags, 0);
2727 if (!desc)
2728 return err;
2729
2730 data = irq_desc_get_irq_data(desc);
2731
2732 do {
2733 chip = irq_data_get_irq_chip(data);
2734 if (WARN_ON_ONCE(!chip)) {
2735 err = -ENODEV;
2736 goto out_unlock;
2737 }
2738 if (chip->irq_set_irqchip_state)
2739 break;
2740#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2741 data = data->parent_data;
2742#else
2743 data = NULL;
2744#endif
2745 } while (data);
2746
2747 if (data)
2748 err = chip->irq_set_irqchip_state(data, which, val);
2749
2750out_unlock:
2751 irq_put_desc_busunlock(desc, flags);
2752 return err;
2753}
2754EXPORT_SYMBOL_GPL(irq_set_irqchip_state);