Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
29
30static int __init setup_forced_irqthreads(char *arg)
31{
32 static_branch_enable(&force_irqthreads_key);
33 return 0;
34}
35early_param("threadirqs", setup_forced_irqthreads);
36#endif
37
38static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
39{
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
41 bool inprogress;
42
43 do {
44 unsigned long flags;
45
46 /*
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
49 */
50 while (irqd_irq_inprogress(&desc->irq_data))
51 cpu_relax();
52
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
56
57 /*
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
61 */
62 if (!inprogress && sync_chip) {
63 /*
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
66 */
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
68 &inprogress);
69 }
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
71
72 /* Oops, that failed? */
73 } while (inprogress);
74}
75
76/**
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
79 *
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
84 * into account.
85 *
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
88 *
89 * Returns: false if a threaded handler is active.
90 *
91 * This function may be called - with care - from IRQ context.
92 *
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
96 * is the current CPU.
97 */
98bool synchronize_hardirq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
105 }
106
107 return true;
108}
109EXPORT_SYMBOL(synchronize_hardirq);
110
111/**
112 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
113 * @irq: interrupt number to wait for
114 *
115 * This function waits for any pending IRQ handlers for this interrupt
116 * to complete before returning. If you use this function while
117 * holding a resource the IRQ handler may need you will deadlock.
118 *
119 * Can only be called from preemptible code as it might sleep when
120 * an interrupt thread is associated to @irq.
121 *
122 * It optionally makes sure (when the irq chip supports that method)
123 * that the interrupt is not pending in any CPU and waiting for
124 * service.
125 */
126void synchronize_irq(unsigned int irq)
127{
128 struct irq_desc *desc = irq_to_desc(irq);
129
130 if (desc) {
131 __synchronize_hardirq(desc, true);
132 /*
133 * We made sure that no hardirq handler is
134 * running. Now verify that no threaded handlers are
135 * active.
136 */
137 wait_event(desc->wait_for_threads,
138 !atomic_read(&desc->threads_active));
139 }
140}
141EXPORT_SYMBOL(synchronize_irq);
142
143#ifdef CONFIG_SMP
144cpumask_var_t irq_default_affinity;
145
146static bool __irq_can_set_affinity(struct irq_desc *desc)
147{
148 if (!desc || !irqd_can_balance(&desc->irq_data) ||
149 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
150 return false;
151 return true;
152}
153
154/**
155 * irq_can_set_affinity - Check if the affinity of a given irq can be set
156 * @irq: Interrupt to check
157 *
158 */
159int irq_can_set_affinity(unsigned int irq)
160{
161 return __irq_can_set_affinity(irq_to_desc(irq));
162}
163
164/**
165 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
166 * @irq: Interrupt to check
167 *
168 * Like irq_can_set_affinity() above, but additionally checks for the
169 * AFFINITY_MANAGED flag.
170 */
171bool irq_can_set_affinity_usr(unsigned int irq)
172{
173 struct irq_desc *desc = irq_to_desc(irq);
174
175 return __irq_can_set_affinity(desc) &&
176 !irqd_affinity_is_managed(&desc->irq_data);
177}
178
179/**
180 * irq_set_thread_affinity - Notify irq threads to adjust affinity
181 * @desc: irq descriptor which has affinity changed
182 *
183 * We just set IRQTF_AFFINITY and delegate the affinity setting
184 * to the interrupt thread itself. We can not call
185 * set_cpus_allowed_ptr() here as we hold desc->lock and this
186 * code can be called from hard interrupt context.
187 */
188void irq_set_thread_affinity(struct irq_desc *desc)
189{
190 struct irqaction *action;
191
192 for_each_action_of_desc(desc, action)
193 if (action->thread)
194 set_bit(IRQTF_AFFINITY, &action->thread_flags);
195}
196
197#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
198static void irq_validate_effective_affinity(struct irq_data *data)
199{
200 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
201 struct irq_chip *chip = irq_data_get_irq_chip(data);
202
203 if (!cpumask_empty(m))
204 return;
205 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
206 chip->name, data->irq);
207}
208#else
209static inline void irq_validate_effective_affinity(struct irq_data *data) { }
210#endif
211
212int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
213 bool force)
214{
215 struct irq_desc *desc = irq_data_to_desc(data);
216 struct irq_chip *chip = irq_data_get_irq_chip(data);
217 const struct cpumask *prog_mask;
218 int ret;
219
220 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
221 static struct cpumask tmp_mask;
222
223 if (!chip || !chip->irq_set_affinity)
224 return -EINVAL;
225
226 raw_spin_lock(&tmp_mask_lock);
227 /*
228 * If this is a managed interrupt and housekeeping is enabled on
229 * it check whether the requested affinity mask intersects with
230 * a housekeeping CPU. If so, then remove the isolated CPUs from
231 * the mask and just keep the housekeeping CPU(s). This prevents
232 * the affinity setter from routing the interrupt to an isolated
233 * CPU to avoid that I/O submitted from a housekeeping CPU causes
234 * interrupts on an isolated one.
235 *
236 * If the masks do not intersect or include online CPU(s) then
237 * keep the requested mask. The isolated target CPUs are only
238 * receiving interrupts when the I/O operation was submitted
239 * directly from them.
240 *
241 * If all housekeeping CPUs in the affinity mask are offline, the
242 * interrupt will be migrated by the CPU hotplug code once a
243 * housekeeping CPU which belongs to the affinity mask comes
244 * online.
245 */
246 if (irqd_affinity_is_managed(data) &&
247 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
248 const struct cpumask *hk_mask;
249
250 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
251
252 cpumask_and(&tmp_mask, mask, hk_mask);
253 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
254 prog_mask = mask;
255 else
256 prog_mask = &tmp_mask;
257 } else {
258 prog_mask = mask;
259 }
260
261 /*
262 * Make sure we only provide online CPUs to the irqchip,
263 * unless we are being asked to force the affinity (in which
264 * case we do as we are told).
265 */
266 cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
267 if (!force && !cpumask_empty(&tmp_mask))
268 ret = chip->irq_set_affinity(data, &tmp_mask, force);
269 else if (force)
270 ret = chip->irq_set_affinity(data, mask, force);
271 else
272 ret = -EINVAL;
273
274 raw_spin_unlock(&tmp_mask_lock);
275
276 switch (ret) {
277 case IRQ_SET_MASK_OK:
278 case IRQ_SET_MASK_OK_DONE:
279 cpumask_copy(desc->irq_common_data.affinity, mask);
280 fallthrough;
281 case IRQ_SET_MASK_OK_NOCOPY:
282 irq_validate_effective_affinity(data);
283 irq_set_thread_affinity(desc);
284 ret = 0;
285 }
286
287 return ret;
288}
289
290#ifdef CONFIG_GENERIC_PENDING_IRQ
291static inline int irq_set_affinity_pending(struct irq_data *data,
292 const struct cpumask *dest)
293{
294 struct irq_desc *desc = irq_data_to_desc(data);
295
296 irqd_set_move_pending(data);
297 irq_copy_pending(desc, dest);
298 return 0;
299}
300#else
301static inline int irq_set_affinity_pending(struct irq_data *data,
302 const struct cpumask *dest)
303{
304 return -EBUSY;
305}
306#endif
307
308static int irq_try_set_affinity(struct irq_data *data,
309 const struct cpumask *dest, bool force)
310{
311 int ret = irq_do_set_affinity(data, dest, force);
312
313 /*
314 * In case that the underlying vector management is busy and the
315 * architecture supports the generic pending mechanism then utilize
316 * this to avoid returning an error to user space.
317 */
318 if (ret == -EBUSY && !force)
319 ret = irq_set_affinity_pending(data, dest);
320 return ret;
321}
322
323static bool irq_set_affinity_deactivated(struct irq_data *data,
324 const struct cpumask *mask)
325{
326 struct irq_desc *desc = irq_data_to_desc(data);
327
328 /*
329 * Handle irq chips which can handle affinity only in activated
330 * state correctly
331 *
332 * If the interrupt is not yet activated, just store the affinity
333 * mask and do not call the chip driver at all. On activation the
334 * driver has to make sure anyway that the interrupt is in a
335 * usable state so startup works.
336 */
337 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
338 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
339 return false;
340
341 cpumask_copy(desc->irq_common_data.affinity, mask);
342 irq_data_update_effective_affinity(data, mask);
343 irqd_set(data, IRQD_AFFINITY_SET);
344 return true;
345}
346
347int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
348 bool force)
349{
350 struct irq_chip *chip = irq_data_get_irq_chip(data);
351 struct irq_desc *desc = irq_data_to_desc(data);
352 int ret = 0;
353
354 if (!chip || !chip->irq_set_affinity)
355 return -EINVAL;
356
357 if (irq_set_affinity_deactivated(data, mask))
358 return 0;
359
360 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
361 ret = irq_try_set_affinity(data, mask, force);
362 } else {
363 irqd_set_move_pending(data);
364 irq_copy_pending(desc, mask);
365 }
366
367 if (desc->affinity_notify) {
368 kref_get(&desc->affinity_notify->kref);
369 if (!schedule_work(&desc->affinity_notify->work)) {
370 /* Work was already scheduled, drop our extra ref */
371 kref_put(&desc->affinity_notify->kref,
372 desc->affinity_notify->release);
373 }
374 }
375 irqd_set(data, IRQD_AFFINITY_SET);
376
377 return ret;
378}
379
380/**
381 * irq_update_affinity_desc - Update affinity management for an interrupt
382 * @irq: The interrupt number to update
383 * @affinity: Pointer to the affinity descriptor
384 *
385 * This interface can be used to configure the affinity management of
386 * interrupts which have been allocated already.
387 *
388 * There are certain limitations on when it may be used - attempts to use it
389 * for when the kernel is configured for generic IRQ reservation mode (in
390 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
391 * managed/non-managed interrupt accounting. In addition, attempts to use it on
392 * an interrupt which is already started or which has already been configured
393 * as managed will also fail, as these mean invalid init state or double init.
394 */
395int irq_update_affinity_desc(unsigned int irq,
396 struct irq_affinity_desc *affinity)
397{
398 struct irq_desc *desc;
399 unsigned long flags;
400 bool activated;
401 int ret = 0;
402
403 /*
404 * Supporting this with the reservation scheme used by x86 needs
405 * some more thought. Fail it for now.
406 */
407 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
408 return -EOPNOTSUPP;
409
410 desc = irq_get_desc_buslock(irq, &flags, 0);
411 if (!desc)
412 return -EINVAL;
413
414 /* Requires the interrupt to be shut down */
415 if (irqd_is_started(&desc->irq_data)) {
416 ret = -EBUSY;
417 goto out_unlock;
418 }
419
420 /* Interrupts which are already managed cannot be modified */
421 if (irqd_affinity_is_managed(&desc->irq_data)) {
422 ret = -EBUSY;
423 goto out_unlock;
424 }
425
426 /*
427 * Deactivate the interrupt. That's required to undo
428 * anything an earlier activation has established.
429 */
430 activated = irqd_is_activated(&desc->irq_data);
431 if (activated)
432 irq_domain_deactivate_irq(&desc->irq_data);
433
434 if (affinity->is_managed) {
435 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
436 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
437 }
438
439 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
440
441 /* Restore the activation state */
442 if (activated)
443 irq_domain_activate_irq(&desc->irq_data, false);
444
445out_unlock:
446 irq_put_desc_busunlock(desc, flags);
447 return ret;
448}
449
450static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
451 bool force)
452{
453 struct irq_desc *desc = irq_to_desc(irq);
454 unsigned long flags;
455 int ret;
456
457 if (!desc)
458 return -EINVAL;
459
460 raw_spin_lock_irqsave(&desc->lock, flags);
461 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
462 raw_spin_unlock_irqrestore(&desc->lock, flags);
463 return ret;
464}
465
466/**
467 * irq_set_affinity - Set the irq affinity of a given irq
468 * @irq: Interrupt to set affinity
469 * @cpumask: cpumask
470 *
471 * Fails if cpumask does not contain an online CPU
472 */
473int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
474{
475 return __irq_set_affinity(irq, cpumask, false);
476}
477EXPORT_SYMBOL_GPL(irq_set_affinity);
478
479/**
480 * irq_force_affinity - Force the irq affinity of a given irq
481 * @irq: Interrupt to set affinity
482 * @cpumask: cpumask
483 *
484 * Same as irq_set_affinity, but without checking the mask against
485 * online cpus.
486 *
487 * Solely for low level cpu hotplug code, where we need to make per
488 * cpu interrupts affine before the cpu becomes online.
489 */
490int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
491{
492 return __irq_set_affinity(irq, cpumask, true);
493}
494EXPORT_SYMBOL_GPL(irq_force_affinity);
495
496int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
497 bool setaffinity)
498{
499 unsigned long flags;
500 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
501
502 if (!desc)
503 return -EINVAL;
504 desc->affinity_hint = m;
505 irq_put_desc_unlock(desc, flags);
506 if (m && setaffinity)
507 __irq_set_affinity(irq, m, false);
508 return 0;
509}
510EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
511
512static void irq_affinity_notify(struct work_struct *work)
513{
514 struct irq_affinity_notify *notify =
515 container_of(work, struct irq_affinity_notify, work);
516 struct irq_desc *desc = irq_to_desc(notify->irq);
517 cpumask_var_t cpumask;
518 unsigned long flags;
519
520 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
521 goto out;
522
523 raw_spin_lock_irqsave(&desc->lock, flags);
524 if (irq_move_pending(&desc->irq_data))
525 irq_get_pending(cpumask, desc);
526 else
527 cpumask_copy(cpumask, desc->irq_common_data.affinity);
528 raw_spin_unlock_irqrestore(&desc->lock, flags);
529
530 notify->notify(notify, cpumask);
531
532 free_cpumask_var(cpumask);
533out:
534 kref_put(¬ify->kref, notify->release);
535}
536
537/**
538 * irq_set_affinity_notifier - control notification of IRQ affinity changes
539 * @irq: Interrupt for which to enable/disable notification
540 * @notify: Context for notification, or %NULL to disable
541 * notification. Function pointers must be initialised;
542 * the other fields will be initialised by this function.
543 *
544 * Must be called in process context. Notification may only be enabled
545 * after the IRQ is allocated and must be disabled before the IRQ is
546 * freed using free_irq().
547 */
548int
549irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
550{
551 struct irq_desc *desc = irq_to_desc(irq);
552 struct irq_affinity_notify *old_notify;
553 unsigned long flags;
554
555 /* The release function is promised process context */
556 might_sleep();
557
558 if (!desc || desc->istate & IRQS_NMI)
559 return -EINVAL;
560
561 /* Complete initialisation of *notify */
562 if (notify) {
563 notify->irq = irq;
564 kref_init(¬ify->kref);
565 INIT_WORK(¬ify->work, irq_affinity_notify);
566 }
567
568 raw_spin_lock_irqsave(&desc->lock, flags);
569 old_notify = desc->affinity_notify;
570 desc->affinity_notify = notify;
571 raw_spin_unlock_irqrestore(&desc->lock, flags);
572
573 if (old_notify) {
574 if (cancel_work_sync(&old_notify->work)) {
575 /* Pending work had a ref, put that one too */
576 kref_put(&old_notify->kref, old_notify->release);
577 }
578 kref_put(&old_notify->kref, old_notify->release);
579 }
580
581 return 0;
582}
583EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
584
585#ifndef CONFIG_AUTO_IRQ_AFFINITY
586/*
587 * Generic version of the affinity autoselector.
588 */
589int irq_setup_affinity(struct irq_desc *desc)
590{
591 struct cpumask *set = irq_default_affinity;
592 int ret, node = irq_desc_get_node(desc);
593 static DEFINE_RAW_SPINLOCK(mask_lock);
594 static struct cpumask mask;
595
596 /* Excludes PER_CPU and NO_BALANCE interrupts */
597 if (!__irq_can_set_affinity(desc))
598 return 0;
599
600 raw_spin_lock(&mask_lock);
601 /*
602 * Preserve the managed affinity setting and a userspace affinity
603 * setup, but make sure that one of the targets is online.
604 */
605 if (irqd_affinity_is_managed(&desc->irq_data) ||
606 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
607 if (cpumask_intersects(desc->irq_common_data.affinity,
608 cpu_online_mask))
609 set = desc->irq_common_data.affinity;
610 else
611 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
612 }
613
614 cpumask_and(&mask, cpu_online_mask, set);
615 if (cpumask_empty(&mask))
616 cpumask_copy(&mask, cpu_online_mask);
617
618 if (node != NUMA_NO_NODE) {
619 const struct cpumask *nodemask = cpumask_of_node(node);
620
621 /* make sure at least one of the cpus in nodemask is online */
622 if (cpumask_intersects(&mask, nodemask))
623 cpumask_and(&mask, &mask, nodemask);
624 }
625 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
626 raw_spin_unlock(&mask_lock);
627 return ret;
628}
629#else
630/* Wrapper for ALPHA specific affinity selector magic */
631int irq_setup_affinity(struct irq_desc *desc)
632{
633 return irq_select_affinity(irq_desc_get_irq(desc));
634}
635#endif /* CONFIG_AUTO_IRQ_AFFINITY */
636#endif /* CONFIG_SMP */
637
638
639/**
640 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
641 * @irq: interrupt number to set affinity
642 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
643 * specific data for percpu_devid interrupts
644 *
645 * This function uses the vCPU specific data to set the vCPU
646 * affinity for an irq. The vCPU specific data is passed from
647 * outside, such as KVM. One example code path is as below:
648 * KVM -> IOMMU -> irq_set_vcpu_affinity().
649 */
650int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
651{
652 unsigned long flags;
653 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
654 struct irq_data *data;
655 struct irq_chip *chip;
656 int ret = -ENOSYS;
657
658 if (!desc)
659 return -EINVAL;
660
661 data = irq_desc_get_irq_data(desc);
662 do {
663 chip = irq_data_get_irq_chip(data);
664 if (chip && chip->irq_set_vcpu_affinity)
665 break;
666#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
667 data = data->parent_data;
668#else
669 data = NULL;
670#endif
671 } while (data);
672
673 if (data)
674 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
675 irq_put_desc_unlock(desc, flags);
676
677 return ret;
678}
679EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
680
681void __disable_irq(struct irq_desc *desc)
682{
683 if (!desc->depth++)
684 irq_disable(desc);
685}
686
687static int __disable_irq_nosync(unsigned int irq)
688{
689 unsigned long flags;
690 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
691
692 if (!desc)
693 return -EINVAL;
694 __disable_irq(desc);
695 irq_put_desc_busunlock(desc, flags);
696 return 0;
697}
698
699/**
700 * disable_irq_nosync - disable an irq without waiting
701 * @irq: Interrupt to disable
702 *
703 * Disable the selected interrupt line. Disables and Enables are
704 * nested.
705 * Unlike disable_irq(), this function does not ensure existing
706 * instances of the IRQ handler have completed before returning.
707 *
708 * This function may be called from IRQ context.
709 */
710void disable_irq_nosync(unsigned int irq)
711{
712 __disable_irq_nosync(irq);
713}
714EXPORT_SYMBOL(disable_irq_nosync);
715
716/**
717 * disable_irq - disable an irq and wait for completion
718 * @irq: Interrupt to disable
719 *
720 * Disable the selected interrupt line. Enables and Disables are
721 * nested.
722 * This function waits for any pending IRQ handlers for this interrupt
723 * to complete before returning. If you use this function while
724 * holding a resource the IRQ handler may need you will deadlock.
725 *
726 * This function may be called - with care - from IRQ context.
727 */
728void disable_irq(unsigned int irq)
729{
730 if (!__disable_irq_nosync(irq))
731 synchronize_irq(irq);
732}
733EXPORT_SYMBOL(disable_irq);
734
735/**
736 * disable_hardirq - disables an irq and waits for hardirq completion
737 * @irq: Interrupt to disable
738 *
739 * Disable the selected interrupt line. Enables and Disables are
740 * nested.
741 * This function waits for any pending hard IRQ handlers for this
742 * interrupt to complete before returning. If you use this function while
743 * holding a resource the hard IRQ handler may need you will deadlock.
744 *
745 * When used to optimistically disable an interrupt from atomic context
746 * the return value must be checked.
747 *
748 * Returns: false if a threaded handler is active.
749 *
750 * This function may be called - with care - from IRQ context.
751 */
752bool disable_hardirq(unsigned int irq)
753{
754 if (!__disable_irq_nosync(irq))
755 return synchronize_hardirq(irq);
756
757 return false;
758}
759EXPORT_SYMBOL_GPL(disable_hardirq);
760
761/**
762 * disable_nmi_nosync - disable an nmi without waiting
763 * @irq: Interrupt to disable
764 *
765 * Disable the selected interrupt line. Disables and enables are
766 * nested.
767 * The interrupt to disable must have been requested through request_nmi.
768 * Unlike disable_nmi(), this function does not ensure existing
769 * instances of the IRQ handler have completed before returning.
770 */
771void disable_nmi_nosync(unsigned int irq)
772{
773 disable_irq_nosync(irq);
774}
775
776void __enable_irq(struct irq_desc *desc)
777{
778 switch (desc->depth) {
779 case 0:
780 err_out:
781 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
782 irq_desc_get_irq(desc));
783 break;
784 case 1: {
785 if (desc->istate & IRQS_SUSPENDED)
786 goto err_out;
787 /* Prevent probing on this irq: */
788 irq_settings_set_noprobe(desc);
789 /*
790 * Call irq_startup() not irq_enable() here because the
791 * interrupt might be marked NOAUTOEN. So irq_startup()
792 * needs to be invoked when it gets enabled the first
793 * time. If it was already started up, then irq_startup()
794 * will invoke irq_enable() under the hood.
795 */
796 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
797 break;
798 }
799 default:
800 desc->depth--;
801 }
802}
803
804/**
805 * enable_irq - enable handling of an irq
806 * @irq: Interrupt to enable
807 *
808 * Undoes the effect of one call to disable_irq(). If this
809 * matches the last disable, processing of interrupts on this
810 * IRQ line is re-enabled.
811 *
812 * This function may be called from IRQ context only when
813 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
814 */
815void enable_irq(unsigned int irq)
816{
817 unsigned long flags;
818 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
819
820 if (!desc)
821 return;
822 if (WARN(!desc->irq_data.chip,
823 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
824 goto out;
825
826 __enable_irq(desc);
827out:
828 irq_put_desc_busunlock(desc, flags);
829}
830EXPORT_SYMBOL(enable_irq);
831
832/**
833 * enable_nmi - enable handling of an nmi
834 * @irq: Interrupt to enable
835 *
836 * The interrupt to enable must have been requested through request_nmi.
837 * Undoes the effect of one call to disable_nmi(). If this
838 * matches the last disable, processing of interrupts on this
839 * IRQ line is re-enabled.
840 */
841void enable_nmi(unsigned int irq)
842{
843 enable_irq(irq);
844}
845
846static int set_irq_wake_real(unsigned int irq, unsigned int on)
847{
848 struct irq_desc *desc = irq_to_desc(irq);
849 int ret = -ENXIO;
850
851 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
852 return 0;
853
854 if (desc->irq_data.chip->irq_set_wake)
855 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
856
857 return ret;
858}
859
860/**
861 * irq_set_irq_wake - control irq power management wakeup
862 * @irq: interrupt to control
863 * @on: enable/disable power management wakeup
864 *
865 * Enable/disable power management wakeup mode, which is
866 * disabled by default. Enables and disables must match,
867 * just as they match for non-wakeup mode support.
868 *
869 * Wakeup mode lets this IRQ wake the system from sleep
870 * states like "suspend to RAM".
871 *
872 * Note: irq enable/disable state is completely orthogonal
873 * to the enable/disable state of irq wake. An irq can be
874 * disabled with disable_irq() and still wake the system as
875 * long as the irq has wake enabled. If this does not hold,
876 * then the underlying irq chip and the related driver need
877 * to be investigated.
878 */
879int irq_set_irq_wake(unsigned int irq, unsigned int on)
880{
881 unsigned long flags;
882 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
883 int ret = 0;
884
885 if (!desc)
886 return -EINVAL;
887
888 /* Don't use NMIs as wake up interrupts please */
889 if (desc->istate & IRQS_NMI) {
890 ret = -EINVAL;
891 goto out_unlock;
892 }
893
894 /* wakeup-capable irqs can be shared between drivers that
895 * don't need to have the same sleep mode behaviors.
896 */
897 if (on) {
898 if (desc->wake_depth++ == 0) {
899 ret = set_irq_wake_real(irq, on);
900 if (ret)
901 desc->wake_depth = 0;
902 else
903 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
904 }
905 } else {
906 if (desc->wake_depth == 0) {
907 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
908 } else if (--desc->wake_depth == 0) {
909 ret = set_irq_wake_real(irq, on);
910 if (ret)
911 desc->wake_depth = 1;
912 else
913 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
914 }
915 }
916
917out_unlock:
918 irq_put_desc_busunlock(desc, flags);
919 return ret;
920}
921EXPORT_SYMBOL(irq_set_irq_wake);
922
923/*
924 * Internal function that tells the architecture code whether a
925 * particular irq has been exclusively allocated or is available
926 * for driver use.
927 */
928int can_request_irq(unsigned int irq, unsigned long irqflags)
929{
930 unsigned long flags;
931 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
932 int canrequest = 0;
933
934 if (!desc)
935 return 0;
936
937 if (irq_settings_can_request(desc)) {
938 if (!desc->action ||
939 irqflags & desc->action->flags & IRQF_SHARED)
940 canrequest = 1;
941 }
942 irq_put_desc_unlock(desc, flags);
943 return canrequest;
944}
945
946int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
947{
948 struct irq_chip *chip = desc->irq_data.chip;
949 int ret, unmask = 0;
950
951 if (!chip || !chip->irq_set_type) {
952 /*
953 * IRQF_TRIGGER_* but the PIC does not support multiple
954 * flow-types?
955 */
956 pr_debug("No set_type function for IRQ %d (%s)\n",
957 irq_desc_get_irq(desc),
958 chip ? (chip->name ? : "unknown") : "unknown");
959 return 0;
960 }
961
962 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
963 if (!irqd_irq_masked(&desc->irq_data))
964 mask_irq(desc);
965 if (!irqd_irq_disabled(&desc->irq_data))
966 unmask = 1;
967 }
968
969 /* Mask all flags except trigger mode */
970 flags &= IRQ_TYPE_SENSE_MASK;
971 ret = chip->irq_set_type(&desc->irq_data, flags);
972
973 switch (ret) {
974 case IRQ_SET_MASK_OK:
975 case IRQ_SET_MASK_OK_DONE:
976 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
977 irqd_set(&desc->irq_data, flags);
978 fallthrough;
979
980 case IRQ_SET_MASK_OK_NOCOPY:
981 flags = irqd_get_trigger_type(&desc->irq_data);
982 irq_settings_set_trigger_mask(desc, flags);
983 irqd_clear(&desc->irq_data, IRQD_LEVEL);
984 irq_settings_clr_level(desc);
985 if (flags & IRQ_TYPE_LEVEL_MASK) {
986 irq_settings_set_level(desc);
987 irqd_set(&desc->irq_data, IRQD_LEVEL);
988 }
989
990 ret = 0;
991 break;
992 default:
993 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
994 flags, irq_desc_get_irq(desc), chip->irq_set_type);
995 }
996 if (unmask)
997 unmask_irq(desc);
998 return ret;
999}
1000
1001#ifdef CONFIG_HARDIRQS_SW_RESEND
1002int irq_set_parent(int irq, int parent_irq)
1003{
1004 unsigned long flags;
1005 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1006
1007 if (!desc)
1008 return -EINVAL;
1009
1010 desc->parent_irq = parent_irq;
1011
1012 irq_put_desc_unlock(desc, flags);
1013 return 0;
1014}
1015EXPORT_SYMBOL_GPL(irq_set_parent);
1016#endif
1017
1018/*
1019 * Default primary interrupt handler for threaded interrupts. Is
1020 * assigned as primary handler when request_threaded_irq is called
1021 * with handler == NULL. Useful for oneshot interrupts.
1022 */
1023static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1024{
1025 return IRQ_WAKE_THREAD;
1026}
1027
1028/*
1029 * Primary handler for nested threaded interrupts. Should never be
1030 * called.
1031 */
1032static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1033{
1034 WARN(1, "Primary handler called for nested irq %d\n", irq);
1035 return IRQ_NONE;
1036}
1037
1038static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1039{
1040 WARN(1, "Secondary action handler called for irq %d\n", irq);
1041 return IRQ_NONE;
1042}
1043
1044static int irq_wait_for_interrupt(struct irqaction *action)
1045{
1046 for (;;) {
1047 set_current_state(TASK_INTERRUPTIBLE);
1048
1049 if (kthread_should_stop()) {
1050 /* may need to run one last time */
1051 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1052 &action->thread_flags)) {
1053 __set_current_state(TASK_RUNNING);
1054 return 0;
1055 }
1056 __set_current_state(TASK_RUNNING);
1057 return -1;
1058 }
1059
1060 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1061 &action->thread_flags)) {
1062 __set_current_state(TASK_RUNNING);
1063 return 0;
1064 }
1065 schedule();
1066 }
1067}
1068
1069/*
1070 * Oneshot interrupts keep the irq line masked until the threaded
1071 * handler finished. unmask if the interrupt has not been disabled and
1072 * is marked MASKED.
1073 */
1074static void irq_finalize_oneshot(struct irq_desc *desc,
1075 struct irqaction *action)
1076{
1077 if (!(desc->istate & IRQS_ONESHOT) ||
1078 action->handler == irq_forced_secondary_handler)
1079 return;
1080again:
1081 chip_bus_lock(desc);
1082 raw_spin_lock_irq(&desc->lock);
1083
1084 /*
1085 * Implausible though it may be we need to protect us against
1086 * the following scenario:
1087 *
1088 * The thread is faster done than the hard interrupt handler
1089 * on the other CPU. If we unmask the irq line then the
1090 * interrupt can come in again and masks the line, leaves due
1091 * to IRQS_INPROGRESS and the irq line is masked forever.
1092 *
1093 * This also serializes the state of shared oneshot handlers
1094 * versus "desc->threads_oneshot |= action->thread_mask;" in
1095 * irq_wake_thread(). See the comment there which explains the
1096 * serialization.
1097 */
1098 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1099 raw_spin_unlock_irq(&desc->lock);
1100 chip_bus_sync_unlock(desc);
1101 cpu_relax();
1102 goto again;
1103 }
1104
1105 /*
1106 * Now check again, whether the thread should run. Otherwise
1107 * we would clear the threads_oneshot bit of this thread which
1108 * was just set.
1109 */
1110 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1111 goto out_unlock;
1112
1113 desc->threads_oneshot &= ~action->thread_mask;
1114
1115 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1116 irqd_irq_masked(&desc->irq_data))
1117 unmask_threaded_irq(desc);
1118
1119out_unlock:
1120 raw_spin_unlock_irq(&desc->lock);
1121 chip_bus_sync_unlock(desc);
1122}
1123
1124#ifdef CONFIG_SMP
1125/*
1126 * Check whether we need to change the affinity of the interrupt thread.
1127 */
1128static void
1129irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1130{
1131 cpumask_var_t mask;
1132 bool valid = true;
1133
1134 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1135 return;
1136
1137 /*
1138 * In case we are out of memory we set IRQTF_AFFINITY again and
1139 * try again next time
1140 */
1141 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1142 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1143 return;
1144 }
1145
1146 raw_spin_lock_irq(&desc->lock);
1147 /*
1148 * This code is triggered unconditionally. Check the affinity
1149 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1150 */
1151 if (cpumask_available(desc->irq_common_data.affinity)) {
1152 const struct cpumask *m;
1153
1154 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1155 cpumask_copy(mask, m);
1156 } else {
1157 valid = false;
1158 }
1159 raw_spin_unlock_irq(&desc->lock);
1160
1161 if (valid)
1162 set_cpus_allowed_ptr(current, mask);
1163 free_cpumask_var(mask);
1164}
1165#else
1166static inline void
1167irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1168#endif
1169
1170/*
1171 * Interrupts which are not explicitly requested as threaded
1172 * interrupts rely on the implicit bh/preempt disable of the hard irq
1173 * context. So we need to disable bh here to avoid deadlocks and other
1174 * side effects.
1175 */
1176static irqreturn_t
1177irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1178{
1179 irqreturn_t ret;
1180
1181 local_bh_disable();
1182 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1183 local_irq_disable();
1184 ret = action->thread_fn(action->irq, action->dev_id);
1185 if (ret == IRQ_HANDLED)
1186 atomic_inc(&desc->threads_handled);
1187
1188 irq_finalize_oneshot(desc, action);
1189 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1190 local_irq_enable();
1191 local_bh_enable();
1192 return ret;
1193}
1194
1195/*
1196 * Interrupts explicitly requested as threaded interrupts want to be
1197 * preemptible - many of them need to sleep and wait for slow busses to
1198 * complete.
1199 */
1200static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1201 struct irqaction *action)
1202{
1203 irqreturn_t ret;
1204
1205 ret = action->thread_fn(action->irq, action->dev_id);
1206 if (ret == IRQ_HANDLED)
1207 atomic_inc(&desc->threads_handled);
1208
1209 irq_finalize_oneshot(desc, action);
1210 return ret;
1211}
1212
1213static void wake_threads_waitq(struct irq_desc *desc)
1214{
1215 if (atomic_dec_and_test(&desc->threads_active))
1216 wake_up(&desc->wait_for_threads);
1217}
1218
1219static void irq_thread_dtor(struct callback_head *unused)
1220{
1221 struct task_struct *tsk = current;
1222 struct irq_desc *desc;
1223 struct irqaction *action;
1224
1225 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1226 return;
1227
1228 action = kthread_data(tsk);
1229
1230 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1231 tsk->comm, tsk->pid, action->irq);
1232
1233
1234 desc = irq_to_desc(action->irq);
1235 /*
1236 * If IRQTF_RUNTHREAD is set, we need to decrement
1237 * desc->threads_active and wake possible waiters.
1238 */
1239 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1240 wake_threads_waitq(desc);
1241
1242 /* Prevent a stale desc->threads_oneshot */
1243 irq_finalize_oneshot(desc, action);
1244}
1245
1246static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1247{
1248 struct irqaction *secondary = action->secondary;
1249
1250 if (WARN_ON_ONCE(!secondary))
1251 return;
1252
1253 raw_spin_lock_irq(&desc->lock);
1254 __irq_wake_thread(desc, secondary);
1255 raw_spin_unlock_irq(&desc->lock);
1256}
1257
1258/*
1259 * Internal function to notify that a interrupt thread is ready.
1260 */
1261static void irq_thread_set_ready(struct irq_desc *desc,
1262 struct irqaction *action)
1263{
1264 set_bit(IRQTF_READY, &action->thread_flags);
1265 wake_up(&desc->wait_for_threads);
1266}
1267
1268/*
1269 * Internal function to wake up a interrupt thread and wait until it is
1270 * ready.
1271 */
1272static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1273 struct irqaction *action)
1274{
1275 if (!action || !action->thread)
1276 return;
1277
1278 wake_up_process(action->thread);
1279 wait_event(desc->wait_for_threads,
1280 test_bit(IRQTF_READY, &action->thread_flags));
1281}
1282
1283/*
1284 * Interrupt handler thread
1285 */
1286static int irq_thread(void *data)
1287{
1288 struct callback_head on_exit_work;
1289 struct irqaction *action = data;
1290 struct irq_desc *desc = irq_to_desc(action->irq);
1291 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1292 struct irqaction *action);
1293
1294 irq_thread_set_ready(desc, action);
1295
1296 sched_set_fifo(current);
1297
1298 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1299 &action->thread_flags))
1300 handler_fn = irq_forced_thread_fn;
1301 else
1302 handler_fn = irq_thread_fn;
1303
1304 init_task_work(&on_exit_work, irq_thread_dtor);
1305 task_work_add(current, &on_exit_work, TWA_NONE);
1306
1307 irq_thread_check_affinity(desc, action);
1308
1309 while (!irq_wait_for_interrupt(action)) {
1310 irqreturn_t action_ret;
1311
1312 irq_thread_check_affinity(desc, action);
1313
1314 action_ret = handler_fn(desc, action);
1315 if (action_ret == IRQ_WAKE_THREAD)
1316 irq_wake_secondary(desc, action);
1317
1318 wake_threads_waitq(desc);
1319 }
1320
1321 /*
1322 * This is the regular exit path. __free_irq() is stopping the
1323 * thread via kthread_stop() after calling
1324 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1325 * oneshot mask bit can be set.
1326 */
1327 task_work_cancel(current, irq_thread_dtor);
1328 return 0;
1329}
1330
1331/**
1332 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1333 * @irq: Interrupt line
1334 * @dev_id: Device identity for which the thread should be woken
1335 *
1336 */
1337void irq_wake_thread(unsigned int irq, void *dev_id)
1338{
1339 struct irq_desc *desc = irq_to_desc(irq);
1340 struct irqaction *action;
1341 unsigned long flags;
1342
1343 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1344 return;
1345
1346 raw_spin_lock_irqsave(&desc->lock, flags);
1347 for_each_action_of_desc(desc, action) {
1348 if (action->dev_id == dev_id) {
1349 if (action->thread)
1350 __irq_wake_thread(desc, action);
1351 break;
1352 }
1353 }
1354 raw_spin_unlock_irqrestore(&desc->lock, flags);
1355}
1356EXPORT_SYMBOL_GPL(irq_wake_thread);
1357
1358static int irq_setup_forced_threading(struct irqaction *new)
1359{
1360 if (!force_irqthreads())
1361 return 0;
1362 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1363 return 0;
1364
1365 /*
1366 * No further action required for interrupts which are requested as
1367 * threaded interrupts already
1368 */
1369 if (new->handler == irq_default_primary_handler)
1370 return 0;
1371
1372 new->flags |= IRQF_ONESHOT;
1373
1374 /*
1375 * Handle the case where we have a real primary handler and a
1376 * thread handler. We force thread them as well by creating a
1377 * secondary action.
1378 */
1379 if (new->handler && new->thread_fn) {
1380 /* Allocate the secondary action */
1381 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1382 if (!new->secondary)
1383 return -ENOMEM;
1384 new->secondary->handler = irq_forced_secondary_handler;
1385 new->secondary->thread_fn = new->thread_fn;
1386 new->secondary->dev_id = new->dev_id;
1387 new->secondary->irq = new->irq;
1388 new->secondary->name = new->name;
1389 }
1390 /* Deal with the primary handler */
1391 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1392 new->thread_fn = new->handler;
1393 new->handler = irq_default_primary_handler;
1394 return 0;
1395}
1396
1397static int irq_request_resources(struct irq_desc *desc)
1398{
1399 struct irq_data *d = &desc->irq_data;
1400 struct irq_chip *c = d->chip;
1401
1402 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1403}
1404
1405static void irq_release_resources(struct irq_desc *desc)
1406{
1407 struct irq_data *d = &desc->irq_data;
1408 struct irq_chip *c = d->chip;
1409
1410 if (c->irq_release_resources)
1411 c->irq_release_resources(d);
1412}
1413
1414static bool irq_supports_nmi(struct irq_desc *desc)
1415{
1416 struct irq_data *d = irq_desc_get_irq_data(desc);
1417
1418#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1419 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1420 if (d->parent_data)
1421 return false;
1422#endif
1423 /* Don't support NMIs for chips behind a slow bus */
1424 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1425 return false;
1426
1427 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1428}
1429
1430static int irq_nmi_setup(struct irq_desc *desc)
1431{
1432 struct irq_data *d = irq_desc_get_irq_data(desc);
1433 struct irq_chip *c = d->chip;
1434
1435 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1436}
1437
1438static void irq_nmi_teardown(struct irq_desc *desc)
1439{
1440 struct irq_data *d = irq_desc_get_irq_data(desc);
1441 struct irq_chip *c = d->chip;
1442
1443 if (c->irq_nmi_teardown)
1444 c->irq_nmi_teardown(d);
1445}
1446
1447static int
1448setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1449{
1450 struct task_struct *t;
1451
1452 if (!secondary) {
1453 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1454 new->name);
1455 } else {
1456 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1457 new->name);
1458 }
1459
1460 if (IS_ERR(t))
1461 return PTR_ERR(t);
1462
1463 /*
1464 * We keep the reference to the task struct even if
1465 * the thread dies to avoid that the interrupt code
1466 * references an already freed task_struct.
1467 */
1468 new->thread = get_task_struct(t);
1469 /*
1470 * Tell the thread to set its affinity. This is
1471 * important for shared interrupt handlers as we do
1472 * not invoke setup_affinity() for the secondary
1473 * handlers as everything is already set up. Even for
1474 * interrupts marked with IRQF_NO_BALANCE this is
1475 * correct as we want the thread to move to the cpu(s)
1476 * on which the requesting code placed the interrupt.
1477 */
1478 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1479 return 0;
1480}
1481
1482/*
1483 * Internal function to register an irqaction - typically used to
1484 * allocate special interrupts that are part of the architecture.
1485 *
1486 * Locking rules:
1487 *
1488 * desc->request_mutex Provides serialization against a concurrent free_irq()
1489 * chip_bus_lock Provides serialization for slow bus operations
1490 * desc->lock Provides serialization against hard interrupts
1491 *
1492 * chip_bus_lock and desc->lock are sufficient for all other management and
1493 * interrupt related functions. desc->request_mutex solely serializes
1494 * request/free_irq().
1495 */
1496static int
1497__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1498{
1499 struct irqaction *old, **old_ptr;
1500 unsigned long flags, thread_mask = 0;
1501 int ret, nested, shared = 0;
1502
1503 if (!desc)
1504 return -EINVAL;
1505
1506 if (desc->irq_data.chip == &no_irq_chip)
1507 return -ENOSYS;
1508 if (!try_module_get(desc->owner))
1509 return -ENODEV;
1510
1511 new->irq = irq;
1512
1513 /*
1514 * If the trigger type is not specified by the caller,
1515 * then use the default for this interrupt.
1516 */
1517 if (!(new->flags & IRQF_TRIGGER_MASK))
1518 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1519
1520 /*
1521 * Check whether the interrupt nests into another interrupt
1522 * thread.
1523 */
1524 nested = irq_settings_is_nested_thread(desc);
1525 if (nested) {
1526 if (!new->thread_fn) {
1527 ret = -EINVAL;
1528 goto out_mput;
1529 }
1530 /*
1531 * Replace the primary handler which was provided from
1532 * the driver for non nested interrupt handling by the
1533 * dummy function which warns when called.
1534 */
1535 new->handler = irq_nested_primary_handler;
1536 } else {
1537 if (irq_settings_can_thread(desc)) {
1538 ret = irq_setup_forced_threading(new);
1539 if (ret)
1540 goto out_mput;
1541 }
1542 }
1543
1544 /*
1545 * Create a handler thread when a thread function is supplied
1546 * and the interrupt does not nest into another interrupt
1547 * thread.
1548 */
1549 if (new->thread_fn && !nested) {
1550 ret = setup_irq_thread(new, irq, false);
1551 if (ret)
1552 goto out_mput;
1553 if (new->secondary) {
1554 ret = setup_irq_thread(new->secondary, irq, true);
1555 if (ret)
1556 goto out_thread;
1557 }
1558 }
1559
1560 /*
1561 * Drivers are often written to work w/o knowledge about the
1562 * underlying irq chip implementation, so a request for a
1563 * threaded irq without a primary hard irq context handler
1564 * requires the ONESHOT flag to be set. Some irq chips like
1565 * MSI based interrupts are per se one shot safe. Check the
1566 * chip flags, so we can avoid the unmask dance at the end of
1567 * the threaded handler for those.
1568 */
1569 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1570 new->flags &= ~IRQF_ONESHOT;
1571
1572 /*
1573 * Protects against a concurrent __free_irq() call which might wait
1574 * for synchronize_hardirq() to complete without holding the optional
1575 * chip bus lock and desc->lock. Also protects against handing out
1576 * a recycled oneshot thread_mask bit while it's still in use by
1577 * its previous owner.
1578 */
1579 mutex_lock(&desc->request_mutex);
1580
1581 /*
1582 * Acquire bus lock as the irq_request_resources() callback below
1583 * might rely on the serialization or the magic power management
1584 * functions which are abusing the irq_bus_lock() callback,
1585 */
1586 chip_bus_lock(desc);
1587
1588 /* First installed action requests resources. */
1589 if (!desc->action) {
1590 ret = irq_request_resources(desc);
1591 if (ret) {
1592 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1593 new->name, irq, desc->irq_data.chip->name);
1594 goto out_bus_unlock;
1595 }
1596 }
1597
1598 /*
1599 * The following block of code has to be executed atomically
1600 * protected against a concurrent interrupt and any of the other
1601 * management calls which are not serialized via
1602 * desc->request_mutex or the optional bus lock.
1603 */
1604 raw_spin_lock_irqsave(&desc->lock, flags);
1605 old_ptr = &desc->action;
1606 old = *old_ptr;
1607 if (old) {
1608 /*
1609 * Can't share interrupts unless both agree to and are
1610 * the same type (level, edge, polarity). So both flag
1611 * fields must have IRQF_SHARED set and the bits which
1612 * set the trigger type must match. Also all must
1613 * agree on ONESHOT.
1614 * Interrupt lines used for NMIs cannot be shared.
1615 */
1616 unsigned int oldtype;
1617
1618 if (desc->istate & IRQS_NMI) {
1619 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1620 new->name, irq, desc->irq_data.chip->name);
1621 ret = -EINVAL;
1622 goto out_unlock;
1623 }
1624
1625 /*
1626 * If nobody did set the configuration before, inherit
1627 * the one provided by the requester.
1628 */
1629 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1630 oldtype = irqd_get_trigger_type(&desc->irq_data);
1631 } else {
1632 oldtype = new->flags & IRQF_TRIGGER_MASK;
1633 irqd_set_trigger_type(&desc->irq_data, oldtype);
1634 }
1635
1636 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1637 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1638 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1639 goto mismatch;
1640
1641 /* All handlers must agree on per-cpuness */
1642 if ((old->flags & IRQF_PERCPU) !=
1643 (new->flags & IRQF_PERCPU))
1644 goto mismatch;
1645
1646 /* add new interrupt at end of irq queue */
1647 do {
1648 /*
1649 * Or all existing action->thread_mask bits,
1650 * so we can find the next zero bit for this
1651 * new action.
1652 */
1653 thread_mask |= old->thread_mask;
1654 old_ptr = &old->next;
1655 old = *old_ptr;
1656 } while (old);
1657 shared = 1;
1658 }
1659
1660 /*
1661 * Setup the thread mask for this irqaction for ONESHOT. For
1662 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1663 * conditional in irq_wake_thread().
1664 */
1665 if (new->flags & IRQF_ONESHOT) {
1666 /*
1667 * Unlikely to have 32 resp 64 irqs sharing one line,
1668 * but who knows.
1669 */
1670 if (thread_mask == ~0UL) {
1671 ret = -EBUSY;
1672 goto out_unlock;
1673 }
1674 /*
1675 * The thread_mask for the action is or'ed to
1676 * desc->thread_active to indicate that the
1677 * IRQF_ONESHOT thread handler has been woken, but not
1678 * yet finished. The bit is cleared when a thread
1679 * completes. When all threads of a shared interrupt
1680 * line have completed desc->threads_active becomes
1681 * zero and the interrupt line is unmasked. See
1682 * handle.c:irq_wake_thread() for further information.
1683 *
1684 * If no thread is woken by primary (hard irq context)
1685 * interrupt handlers, then desc->threads_active is
1686 * also checked for zero to unmask the irq line in the
1687 * affected hard irq flow handlers
1688 * (handle_[fasteoi|level]_irq).
1689 *
1690 * The new action gets the first zero bit of
1691 * thread_mask assigned. See the loop above which or's
1692 * all existing action->thread_mask bits.
1693 */
1694 new->thread_mask = 1UL << ffz(thread_mask);
1695
1696 } else if (new->handler == irq_default_primary_handler &&
1697 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1698 /*
1699 * The interrupt was requested with handler = NULL, so
1700 * we use the default primary handler for it. But it
1701 * does not have the oneshot flag set. In combination
1702 * with level interrupts this is deadly, because the
1703 * default primary handler just wakes the thread, then
1704 * the irq lines is reenabled, but the device still
1705 * has the level irq asserted. Rinse and repeat....
1706 *
1707 * While this works for edge type interrupts, we play
1708 * it safe and reject unconditionally because we can't
1709 * say for sure which type this interrupt really
1710 * has. The type flags are unreliable as the
1711 * underlying chip implementation can override them.
1712 */
1713 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1714 new->name, irq);
1715 ret = -EINVAL;
1716 goto out_unlock;
1717 }
1718
1719 if (!shared) {
1720 /* Setup the type (level, edge polarity) if configured: */
1721 if (new->flags & IRQF_TRIGGER_MASK) {
1722 ret = __irq_set_trigger(desc,
1723 new->flags & IRQF_TRIGGER_MASK);
1724
1725 if (ret)
1726 goto out_unlock;
1727 }
1728
1729 /*
1730 * Activate the interrupt. That activation must happen
1731 * independently of IRQ_NOAUTOEN. request_irq() can fail
1732 * and the callers are supposed to handle
1733 * that. enable_irq() of an interrupt requested with
1734 * IRQ_NOAUTOEN is not supposed to fail. The activation
1735 * keeps it in shutdown mode, it merily associates
1736 * resources if necessary and if that's not possible it
1737 * fails. Interrupts which are in managed shutdown mode
1738 * will simply ignore that activation request.
1739 */
1740 ret = irq_activate(desc);
1741 if (ret)
1742 goto out_unlock;
1743
1744 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1745 IRQS_ONESHOT | IRQS_WAITING);
1746 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1747
1748 if (new->flags & IRQF_PERCPU) {
1749 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1750 irq_settings_set_per_cpu(desc);
1751 if (new->flags & IRQF_NO_DEBUG)
1752 irq_settings_set_no_debug(desc);
1753 }
1754
1755 if (noirqdebug)
1756 irq_settings_set_no_debug(desc);
1757
1758 if (new->flags & IRQF_ONESHOT)
1759 desc->istate |= IRQS_ONESHOT;
1760
1761 /* Exclude IRQ from balancing if requested */
1762 if (new->flags & IRQF_NOBALANCING) {
1763 irq_settings_set_no_balancing(desc);
1764 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1765 }
1766
1767 if (!(new->flags & IRQF_NO_AUTOEN) &&
1768 irq_settings_can_autoenable(desc)) {
1769 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1770 } else {
1771 /*
1772 * Shared interrupts do not go well with disabling
1773 * auto enable. The sharing interrupt might request
1774 * it while it's still disabled and then wait for
1775 * interrupts forever.
1776 */
1777 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1778 /* Undo nested disables: */
1779 desc->depth = 1;
1780 }
1781
1782 } else if (new->flags & IRQF_TRIGGER_MASK) {
1783 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1784 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1785
1786 if (nmsk != omsk)
1787 /* hope the handler works with current trigger mode */
1788 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1789 irq, omsk, nmsk);
1790 }
1791
1792 *old_ptr = new;
1793
1794 irq_pm_install_action(desc, new);
1795
1796 /* Reset broken irq detection when installing new handler */
1797 desc->irq_count = 0;
1798 desc->irqs_unhandled = 0;
1799
1800 /*
1801 * Check whether we disabled the irq via the spurious handler
1802 * before. Reenable it and give it another chance.
1803 */
1804 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1805 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1806 __enable_irq(desc);
1807 }
1808
1809 raw_spin_unlock_irqrestore(&desc->lock, flags);
1810 chip_bus_sync_unlock(desc);
1811 mutex_unlock(&desc->request_mutex);
1812
1813 irq_setup_timings(desc, new);
1814
1815 wake_up_and_wait_for_irq_thread_ready(desc, new);
1816 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1817
1818 register_irq_proc(irq, desc);
1819 new->dir = NULL;
1820 register_handler_proc(irq, new);
1821 return 0;
1822
1823mismatch:
1824 if (!(new->flags & IRQF_PROBE_SHARED)) {
1825 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1826 irq, new->flags, new->name, old->flags, old->name);
1827#ifdef CONFIG_DEBUG_SHIRQ
1828 dump_stack();
1829#endif
1830 }
1831 ret = -EBUSY;
1832
1833out_unlock:
1834 raw_spin_unlock_irqrestore(&desc->lock, flags);
1835
1836 if (!desc->action)
1837 irq_release_resources(desc);
1838out_bus_unlock:
1839 chip_bus_sync_unlock(desc);
1840 mutex_unlock(&desc->request_mutex);
1841
1842out_thread:
1843 if (new->thread) {
1844 struct task_struct *t = new->thread;
1845
1846 new->thread = NULL;
1847 kthread_stop(t);
1848 put_task_struct(t);
1849 }
1850 if (new->secondary && new->secondary->thread) {
1851 struct task_struct *t = new->secondary->thread;
1852
1853 new->secondary->thread = NULL;
1854 kthread_stop(t);
1855 put_task_struct(t);
1856 }
1857out_mput:
1858 module_put(desc->owner);
1859 return ret;
1860}
1861
1862/*
1863 * Internal function to unregister an irqaction - used to free
1864 * regular and special interrupts that are part of the architecture.
1865 */
1866static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1867{
1868 unsigned irq = desc->irq_data.irq;
1869 struct irqaction *action, **action_ptr;
1870 unsigned long flags;
1871
1872 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1873
1874 mutex_lock(&desc->request_mutex);
1875 chip_bus_lock(desc);
1876 raw_spin_lock_irqsave(&desc->lock, flags);
1877
1878 /*
1879 * There can be multiple actions per IRQ descriptor, find the right
1880 * one based on the dev_id:
1881 */
1882 action_ptr = &desc->action;
1883 for (;;) {
1884 action = *action_ptr;
1885
1886 if (!action) {
1887 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1888 raw_spin_unlock_irqrestore(&desc->lock, flags);
1889 chip_bus_sync_unlock(desc);
1890 mutex_unlock(&desc->request_mutex);
1891 return NULL;
1892 }
1893
1894 if (action->dev_id == dev_id)
1895 break;
1896 action_ptr = &action->next;
1897 }
1898
1899 /* Found it - now remove it from the list of entries: */
1900 *action_ptr = action->next;
1901
1902 irq_pm_remove_action(desc, action);
1903
1904 /* If this was the last handler, shut down the IRQ line: */
1905 if (!desc->action) {
1906 irq_settings_clr_disable_unlazy(desc);
1907 /* Only shutdown. Deactivate after synchronize_hardirq() */
1908 irq_shutdown(desc);
1909 }
1910
1911#ifdef CONFIG_SMP
1912 /* make sure affinity_hint is cleaned up */
1913 if (WARN_ON_ONCE(desc->affinity_hint))
1914 desc->affinity_hint = NULL;
1915#endif
1916
1917 raw_spin_unlock_irqrestore(&desc->lock, flags);
1918 /*
1919 * Drop bus_lock here so the changes which were done in the chip
1920 * callbacks above are synced out to the irq chips which hang
1921 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1922 *
1923 * Aside of that the bus_lock can also be taken from the threaded
1924 * handler in irq_finalize_oneshot() which results in a deadlock
1925 * because kthread_stop() would wait forever for the thread to
1926 * complete, which is blocked on the bus lock.
1927 *
1928 * The still held desc->request_mutex() protects against a
1929 * concurrent request_irq() of this irq so the release of resources
1930 * and timing data is properly serialized.
1931 */
1932 chip_bus_sync_unlock(desc);
1933
1934 unregister_handler_proc(irq, action);
1935
1936 /*
1937 * Make sure it's not being used on another CPU and if the chip
1938 * supports it also make sure that there is no (not yet serviced)
1939 * interrupt in flight at the hardware level.
1940 */
1941 __synchronize_hardirq(desc, true);
1942
1943#ifdef CONFIG_DEBUG_SHIRQ
1944 /*
1945 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1946 * event to happen even now it's being freed, so let's make sure that
1947 * is so by doing an extra call to the handler ....
1948 *
1949 * ( We do this after actually deregistering it, to make sure that a
1950 * 'real' IRQ doesn't run in parallel with our fake. )
1951 */
1952 if (action->flags & IRQF_SHARED) {
1953 local_irq_save(flags);
1954 action->handler(irq, dev_id);
1955 local_irq_restore(flags);
1956 }
1957#endif
1958
1959 /*
1960 * The action has already been removed above, but the thread writes
1961 * its oneshot mask bit when it completes. Though request_mutex is
1962 * held across this which prevents __setup_irq() from handing out
1963 * the same bit to a newly requested action.
1964 */
1965 if (action->thread) {
1966 kthread_stop(action->thread);
1967 put_task_struct(action->thread);
1968 if (action->secondary && action->secondary->thread) {
1969 kthread_stop(action->secondary->thread);
1970 put_task_struct(action->secondary->thread);
1971 }
1972 }
1973
1974 /* Last action releases resources */
1975 if (!desc->action) {
1976 /*
1977 * Reacquire bus lock as irq_release_resources() might
1978 * require it to deallocate resources over the slow bus.
1979 */
1980 chip_bus_lock(desc);
1981 /*
1982 * There is no interrupt on the fly anymore. Deactivate it
1983 * completely.
1984 */
1985 raw_spin_lock_irqsave(&desc->lock, flags);
1986 irq_domain_deactivate_irq(&desc->irq_data);
1987 raw_spin_unlock_irqrestore(&desc->lock, flags);
1988
1989 irq_release_resources(desc);
1990 chip_bus_sync_unlock(desc);
1991 irq_remove_timings(desc);
1992 }
1993
1994 mutex_unlock(&desc->request_mutex);
1995
1996 irq_chip_pm_put(&desc->irq_data);
1997 module_put(desc->owner);
1998 kfree(action->secondary);
1999 return action;
2000}
2001
2002/**
2003 * free_irq - free an interrupt allocated with request_irq
2004 * @irq: Interrupt line to free
2005 * @dev_id: Device identity to free
2006 *
2007 * Remove an interrupt handler. The handler is removed and if the
2008 * interrupt line is no longer in use by any driver it is disabled.
2009 * On a shared IRQ the caller must ensure the interrupt is disabled
2010 * on the card it drives before calling this function. The function
2011 * does not return until any executing interrupts for this IRQ
2012 * have completed.
2013 *
2014 * This function must not be called from interrupt context.
2015 *
2016 * Returns the devname argument passed to request_irq.
2017 */
2018const void *free_irq(unsigned int irq, void *dev_id)
2019{
2020 struct irq_desc *desc = irq_to_desc(irq);
2021 struct irqaction *action;
2022 const char *devname;
2023
2024 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2025 return NULL;
2026
2027#ifdef CONFIG_SMP
2028 if (WARN_ON(desc->affinity_notify))
2029 desc->affinity_notify = NULL;
2030#endif
2031
2032 action = __free_irq(desc, dev_id);
2033
2034 if (!action)
2035 return NULL;
2036
2037 devname = action->name;
2038 kfree(action);
2039 return devname;
2040}
2041EXPORT_SYMBOL(free_irq);
2042
2043/* This function must be called with desc->lock held */
2044static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2045{
2046 const char *devname = NULL;
2047
2048 desc->istate &= ~IRQS_NMI;
2049
2050 if (!WARN_ON(desc->action == NULL)) {
2051 irq_pm_remove_action(desc, desc->action);
2052 devname = desc->action->name;
2053 unregister_handler_proc(irq, desc->action);
2054
2055 kfree(desc->action);
2056 desc->action = NULL;
2057 }
2058
2059 irq_settings_clr_disable_unlazy(desc);
2060 irq_shutdown_and_deactivate(desc);
2061
2062 irq_release_resources(desc);
2063
2064 irq_chip_pm_put(&desc->irq_data);
2065 module_put(desc->owner);
2066
2067 return devname;
2068}
2069
2070const void *free_nmi(unsigned int irq, void *dev_id)
2071{
2072 struct irq_desc *desc = irq_to_desc(irq);
2073 unsigned long flags;
2074 const void *devname;
2075
2076 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2077 return NULL;
2078
2079 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2080 return NULL;
2081
2082 /* NMI still enabled */
2083 if (WARN_ON(desc->depth == 0))
2084 disable_nmi_nosync(irq);
2085
2086 raw_spin_lock_irqsave(&desc->lock, flags);
2087
2088 irq_nmi_teardown(desc);
2089 devname = __cleanup_nmi(irq, desc);
2090
2091 raw_spin_unlock_irqrestore(&desc->lock, flags);
2092
2093 return devname;
2094}
2095
2096/**
2097 * request_threaded_irq - allocate an interrupt line
2098 * @irq: Interrupt line to allocate
2099 * @handler: Function to be called when the IRQ occurs.
2100 * Primary handler for threaded interrupts.
2101 * If handler is NULL and thread_fn != NULL
2102 * the default primary handler is installed.
2103 * @thread_fn: Function called from the irq handler thread
2104 * If NULL, no irq thread is created
2105 * @irqflags: Interrupt type flags
2106 * @devname: An ascii name for the claiming device
2107 * @dev_id: A cookie passed back to the handler function
2108 *
2109 * This call allocates interrupt resources and enables the
2110 * interrupt line and IRQ handling. From the point this
2111 * call is made your handler function may be invoked. Since
2112 * your handler function must clear any interrupt the board
2113 * raises, you must take care both to initialise your hardware
2114 * and to set up the interrupt handler in the right order.
2115 *
2116 * If you want to set up a threaded irq handler for your device
2117 * then you need to supply @handler and @thread_fn. @handler is
2118 * still called in hard interrupt context and has to check
2119 * whether the interrupt originates from the device. If yes it
2120 * needs to disable the interrupt on the device and return
2121 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2122 * @thread_fn. This split handler design is necessary to support
2123 * shared interrupts.
2124 *
2125 * Dev_id must be globally unique. Normally the address of the
2126 * device data structure is used as the cookie. Since the handler
2127 * receives this value it makes sense to use it.
2128 *
2129 * If your interrupt is shared you must pass a non NULL dev_id
2130 * as this is required when freeing the interrupt.
2131 *
2132 * Flags:
2133 *
2134 * IRQF_SHARED Interrupt is shared
2135 * IRQF_TRIGGER_* Specify active edge(s) or level
2136 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2137 */
2138int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2139 irq_handler_t thread_fn, unsigned long irqflags,
2140 const char *devname, void *dev_id)
2141{
2142 struct irqaction *action;
2143 struct irq_desc *desc;
2144 int retval;
2145
2146 if (irq == IRQ_NOTCONNECTED)
2147 return -ENOTCONN;
2148
2149 /*
2150 * Sanity-check: shared interrupts must pass in a real dev-ID,
2151 * otherwise we'll have trouble later trying to figure out
2152 * which interrupt is which (messes up the interrupt freeing
2153 * logic etc).
2154 *
2155 * Also shared interrupts do not go well with disabling auto enable.
2156 * The sharing interrupt might request it while it's still disabled
2157 * and then wait for interrupts forever.
2158 *
2159 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2160 * it cannot be set along with IRQF_NO_SUSPEND.
2161 */
2162 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2163 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2164 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2165 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2166 return -EINVAL;
2167
2168 desc = irq_to_desc(irq);
2169 if (!desc)
2170 return -EINVAL;
2171
2172 if (!irq_settings_can_request(desc) ||
2173 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2174 return -EINVAL;
2175
2176 if (!handler) {
2177 if (!thread_fn)
2178 return -EINVAL;
2179 handler = irq_default_primary_handler;
2180 }
2181
2182 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2183 if (!action)
2184 return -ENOMEM;
2185
2186 action->handler = handler;
2187 action->thread_fn = thread_fn;
2188 action->flags = irqflags;
2189 action->name = devname;
2190 action->dev_id = dev_id;
2191
2192 retval = irq_chip_pm_get(&desc->irq_data);
2193 if (retval < 0) {
2194 kfree(action);
2195 return retval;
2196 }
2197
2198 retval = __setup_irq(irq, desc, action);
2199
2200 if (retval) {
2201 irq_chip_pm_put(&desc->irq_data);
2202 kfree(action->secondary);
2203 kfree(action);
2204 }
2205
2206#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2207 if (!retval && (irqflags & IRQF_SHARED)) {
2208 /*
2209 * It's a shared IRQ -- the driver ought to be prepared for it
2210 * to happen immediately, so let's make sure....
2211 * We disable the irq to make sure that a 'real' IRQ doesn't
2212 * run in parallel with our fake.
2213 */
2214 unsigned long flags;
2215
2216 disable_irq(irq);
2217 local_irq_save(flags);
2218
2219 handler(irq, dev_id);
2220
2221 local_irq_restore(flags);
2222 enable_irq(irq);
2223 }
2224#endif
2225 return retval;
2226}
2227EXPORT_SYMBOL(request_threaded_irq);
2228
2229/**
2230 * request_any_context_irq - allocate an interrupt line
2231 * @irq: Interrupt line to allocate
2232 * @handler: Function to be called when the IRQ occurs.
2233 * Threaded handler for threaded interrupts.
2234 * @flags: Interrupt type flags
2235 * @name: An ascii name for the claiming device
2236 * @dev_id: A cookie passed back to the handler function
2237 *
2238 * This call allocates interrupt resources and enables the
2239 * interrupt line and IRQ handling. It selects either a
2240 * hardirq or threaded handling method depending on the
2241 * context.
2242 *
2243 * On failure, it returns a negative value. On success,
2244 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2245 */
2246int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2247 unsigned long flags, const char *name, void *dev_id)
2248{
2249 struct irq_desc *desc;
2250 int ret;
2251
2252 if (irq == IRQ_NOTCONNECTED)
2253 return -ENOTCONN;
2254
2255 desc = irq_to_desc(irq);
2256 if (!desc)
2257 return -EINVAL;
2258
2259 if (irq_settings_is_nested_thread(desc)) {
2260 ret = request_threaded_irq(irq, NULL, handler,
2261 flags, name, dev_id);
2262 return !ret ? IRQC_IS_NESTED : ret;
2263 }
2264
2265 ret = request_irq(irq, handler, flags, name, dev_id);
2266 return !ret ? IRQC_IS_HARDIRQ : ret;
2267}
2268EXPORT_SYMBOL_GPL(request_any_context_irq);
2269
2270/**
2271 * request_nmi - allocate an interrupt line for NMI delivery
2272 * @irq: Interrupt line to allocate
2273 * @handler: Function to be called when the IRQ occurs.
2274 * Threaded handler for threaded interrupts.
2275 * @irqflags: Interrupt type flags
2276 * @name: An ascii name for the claiming device
2277 * @dev_id: A cookie passed back to the handler function
2278 *
2279 * This call allocates interrupt resources and enables the
2280 * interrupt line and IRQ handling. It sets up the IRQ line
2281 * to be handled as an NMI.
2282 *
2283 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2284 * cannot be threaded.
2285 *
2286 * Interrupt lines requested for NMI delivering must produce per cpu
2287 * interrupts and have auto enabling setting disabled.
2288 *
2289 * Dev_id must be globally unique. Normally the address of the
2290 * device data structure is used as the cookie. Since the handler
2291 * receives this value it makes sense to use it.
2292 *
2293 * If the interrupt line cannot be used to deliver NMIs, function
2294 * will fail and return a negative value.
2295 */
2296int request_nmi(unsigned int irq, irq_handler_t handler,
2297 unsigned long irqflags, const char *name, void *dev_id)
2298{
2299 struct irqaction *action;
2300 struct irq_desc *desc;
2301 unsigned long flags;
2302 int retval;
2303
2304 if (irq == IRQ_NOTCONNECTED)
2305 return -ENOTCONN;
2306
2307 /* NMI cannot be shared, used for Polling */
2308 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2309 return -EINVAL;
2310
2311 if (!(irqflags & IRQF_PERCPU))
2312 return -EINVAL;
2313
2314 if (!handler)
2315 return -EINVAL;
2316
2317 desc = irq_to_desc(irq);
2318
2319 if (!desc || (irq_settings_can_autoenable(desc) &&
2320 !(irqflags & IRQF_NO_AUTOEN)) ||
2321 !irq_settings_can_request(desc) ||
2322 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2323 !irq_supports_nmi(desc))
2324 return -EINVAL;
2325
2326 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2327 if (!action)
2328 return -ENOMEM;
2329
2330 action->handler = handler;
2331 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2332 action->name = name;
2333 action->dev_id = dev_id;
2334
2335 retval = irq_chip_pm_get(&desc->irq_data);
2336 if (retval < 0)
2337 goto err_out;
2338
2339 retval = __setup_irq(irq, desc, action);
2340 if (retval)
2341 goto err_irq_setup;
2342
2343 raw_spin_lock_irqsave(&desc->lock, flags);
2344
2345 /* Setup NMI state */
2346 desc->istate |= IRQS_NMI;
2347 retval = irq_nmi_setup(desc);
2348 if (retval) {
2349 __cleanup_nmi(irq, desc);
2350 raw_spin_unlock_irqrestore(&desc->lock, flags);
2351 return -EINVAL;
2352 }
2353
2354 raw_spin_unlock_irqrestore(&desc->lock, flags);
2355
2356 return 0;
2357
2358err_irq_setup:
2359 irq_chip_pm_put(&desc->irq_data);
2360err_out:
2361 kfree(action);
2362
2363 return retval;
2364}
2365
2366void enable_percpu_irq(unsigned int irq, unsigned int type)
2367{
2368 unsigned int cpu = smp_processor_id();
2369 unsigned long flags;
2370 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2371
2372 if (!desc)
2373 return;
2374
2375 /*
2376 * If the trigger type is not specified by the caller, then
2377 * use the default for this interrupt.
2378 */
2379 type &= IRQ_TYPE_SENSE_MASK;
2380 if (type == IRQ_TYPE_NONE)
2381 type = irqd_get_trigger_type(&desc->irq_data);
2382
2383 if (type != IRQ_TYPE_NONE) {
2384 int ret;
2385
2386 ret = __irq_set_trigger(desc, type);
2387
2388 if (ret) {
2389 WARN(1, "failed to set type for IRQ%d\n", irq);
2390 goto out;
2391 }
2392 }
2393
2394 irq_percpu_enable(desc, cpu);
2395out:
2396 irq_put_desc_unlock(desc, flags);
2397}
2398EXPORT_SYMBOL_GPL(enable_percpu_irq);
2399
2400void enable_percpu_nmi(unsigned int irq, unsigned int type)
2401{
2402 enable_percpu_irq(irq, type);
2403}
2404
2405/**
2406 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2407 * @irq: Linux irq number to check for
2408 *
2409 * Must be called from a non migratable context. Returns the enable
2410 * state of a per cpu interrupt on the current cpu.
2411 */
2412bool irq_percpu_is_enabled(unsigned int irq)
2413{
2414 unsigned int cpu = smp_processor_id();
2415 struct irq_desc *desc;
2416 unsigned long flags;
2417 bool is_enabled;
2418
2419 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2420 if (!desc)
2421 return false;
2422
2423 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2424 irq_put_desc_unlock(desc, flags);
2425
2426 return is_enabled;
2427}
2428EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2429
2430void disable_percpu_irq(unsigned int irq)
2431{
2432 unsigned int cpu = smp_processor_id();
2433 unsigned long flags;
2434 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2435
2436 if (!desc)
2437 return;
2438
2439 irq_percpu_disable(desc, cpu);
2440 irq_put_desc_unlock(desc, flags);
2441}
2442EXPORT_SYMBOL_GPL(disable_percpu_irq);
2443
2444void disable_percpu_nmi(unsigned int irq)
2445{
2446 disable_percpu_irq(irq);
2447}
2448
2449/*
2450 * Internal function to unregister a percpu irqaction.
2451 */
2452static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2453{
2454 struct irq_desc *desc = irq_to_desc(irq);
2455 struct irqaction *action;
2456 unsigned long flags;
2457
2458 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2459
2460 if (!desc)
2461 return NULL;
2462
2463 raw_spin_lock_irqsave(&desc->lock, flags);
2464
2465 action = desc->action;
2466 if (!action || action->percpu_dev_id != dev_id) {
2467 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2468 goto bad;
2469 }
2470
2471 if (!cpumask_empty(desc->percpu_enabled)) {
2472 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2473 irq, cpumask_first(desc->percpu_enabled));
2474 goto bad;
2475 }
2476
2477 /* Found it - now remove it from the list of entries: */
2478 desc->action = NULL;
2479
2480 desc->istate &= ~IRQS_NMI;
2481
2482 raw_spin_unlock_irqrestore(&desc->lock, flags);
2483
2484 unregister_handler_proc(irq, action);
2485
2486 irq_chip_pm_put(&desc->irq_data);
2487 module_put(desc->owner);
2488 return action;
2489
2490bad:
2491 raw_spin_unlock_irqrestore(&desc->lock, flags);
2492 return NULL;
2493}
2494
2495/**
2496 * remove_percpu_irq - free a per-cpu interrupt
2497 * @irq: Interrupt line to free
2498 * @act: irqaction for the interrupt
2499 *
2500 * Used to remove interrupts statically setup by the early boot process.
2501 */
2502void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2503{
2504 struct irq_desc *desc = irq_to_desc(irq);
2505
2506 if (desc && irq_settings_is_per_cpu_devid(desc))
2507 __free_percpu_irq(irq, act->percpu_dev_id);
2508}
2509
2510/**
2511 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2512 * @irq: Interrupt line to free
2513 * @dev_id: Device identity to free
2514 *
2515 * Remove a percpu interrupt handler. The handler is removed, but
2516 * the interrupt line is not disabled. This must be done on each
2517 * CPU before calling this function. The function does not return
2518 * until any executing interrupts for this IRQ have completed.
2519 *
2520 * This function must not be called from interrupt context.
2521 */
2522void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2523{
2524 struct irq_desc *desc = irq_to_desc(irq);
2525
2526 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2527 return;
2528
2529 chip_bus_lock(desc);
2530 kfree(__free_percpu_irq(irq, dev_id));
2531 chip_bus_sync_unlock(desc);
2532}
2533EXPORT_SYMBOL_GPL(free_percpu_irq);
2534
2535void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2536{
2537 struct irq_desc *desc = irq_to_desc(irq);
2538
2539 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2540 return;
2541
2542 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2543 return;
2544
2545 kfree(__free_percpu_irq(irq, dev_id));
2546}
2547
2548/**
2549 * setup_percpu_irq - setup a per-cpu interrupt
2550 * @irq: Interrupt line to setup
2551 * @act: irqaction for the interrupt
2552 *
2553 * Used to statically setup per-cpu interrupts in the early boot process.
2554 */
2555int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2556{
2557 struct irq_desc *desc = irq_to_desc(irq);
2558 int retval;
2559
2560 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2561 return -EINVAL;
2562
2563 retval = irq_chip_pm_get(&desc->irq_data);
2564 if (retval < 0)
2565 return retval;
2566
2567 retval = __setup_irq(irq, desc, act);
2568
2569 if (retval)
2570 irq_chip_pm_put(&desc->irq_data);
2571
2572 return retval;
2573}
2574
2575/**
2576 * __request_percpu_irq - allocate a percpu interrupt line
2577 * @irq: Interrupt line to allocate
2578 * @handler: Function to be called when the IRQ occurs.
2579 * @flags: Interrupt type flags (IRQF_TIMER only)
2580 * @devname: An ascii name for the claiming device
2581 * @dev_id: A percpu cookie passed back to the handler function
2582 *
2583 * This call allocates interrupt resources and enables the
2584 * interrupt on the local CPU. If the interrupt is supposed to be
2585 * enabled on other CPUs, it has to be done on each CPU using
2586 * enable_percpu_irq().
2587 *
2588 * Dev_id must be globally unique. It is a per-cpu variable, and
2589 * the handler gets called with the interrupted CPU's instance of
2590 * that variable.
2591 */
2592int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2593 unsigned long flags, const char *devname,
2594 void __percpu *dev_id)
2595{
2596 struct irqaction *action;
2597 struct irq_desc *desc;
2598 int retval;
2599
2600 if (!dev_id)
2601 return -EINVAL;
2602
2603 desc = irq_to_desc(irq);
2604 if (!desc || !irq_settings_can_request(desc) ||
2605 !irq_settings_is_per_cpu_devid(desc))
2606 return -EINVAL;
2607
2608 if (flags && flags != IRQF_TIMER)
2609 return -EINVAL;
2610
2611 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2612 if (!action)
2613 return -ENOMEM;
2614
2615 action->handler = handler;
2616 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2617 action->name = devname;
2618 action->percpu_dev_id = dev_id;
2619
2620 retval = irq_chip_pm_get(&desc->irq_data);
2621 if (retval < 0) {
2622 kfree(action);
2623 return retval;
2624 }
2625
2626 retval = __setup_irq(irq, desc, action);
2627
2628 if (retval) {
2629 irq_chip_pm_put(&desc->irq_data);
2630 kfree(action);
2631 }
2632
2633 return retval;
2634}
2635EXPORT_SYMBOL_GPL(__request_percpu_irq);
2636
2637/**
2638 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2639 * @irq: Interrupt line to allocate
2640 * @handler: Function to be called when the IRQ occurs.
2641 * @name: An ascii name for the claiming device
2642 * @dev_id: A percpu cookie passed back to the handler function
2643 *
2644 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2645 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2646 * being enabled on the same CPU by using enable_percpu_nmi().
2647 *
2648 * Dev_id must be globally unique. It is a per-cpu variable, and
2649 * the handler gets called with the interrupted CPU's instance of
2650 * that variable.
2651 *
2652 * Interrupt lines requested for NMI delivering should have auto enabling
2653 * setting disabled.
2654 *
2655 * If the interrupt line cannot be used to deliver NMIs, function
2656 * will fail returning a negative value.
2657 */
2658int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2659 const char *name, void __percpu *dev_id)
2660{
2661 struct irqaction *action;
2662 struct irq_desc *desc;
2663 unsigned long flags;
2664 int retval;
2665
2666 if (!handler)
2667 return -EINVAL;
2668
2669 desc = irq_to_desc(irq);
2670
2671 if (!desc || !irq_settings_can_request(desc) ||
2672 !irq_settings_is_per_cpu_devid(desc) ||
2673 irq_settings_can_autoenable(desc) ||
2674 !irq_supports_nmi(desc))
2675 return -EINVAL;
2676
2677 /* The line cannot already be NMI */
2678 if (desc->istate & IRQS_NMI)
2679 return -EINVAL;
2680
2681 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2682 if (!action)
2683 return -ENOMEM;
2684
2685 action->handler = handler;
2686 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2687 | IRQF_NOBALANCING;
2688 action->name = name;
2689 action->percpu_dev_id = dev_id;
2690
2691 retval = irq_chip_pm_get(&desc->irq_data);
2692 if (retval < 0)
2693 goto err_out;
2694
2695 retval = __setup_irq(irq, desc, action);
2696 if (retval)
2697 goto err_irq_setup;
2698
2699 raw_spin_lock_irqsave(&desc->lock, flags);
2700 desc->istate |= IRQS_NMI;
2701 raw_spin_unlock_irqrestore(&desc->lock, flags);
2702
2703 return 0;
2704
2705err_irq_setup:
2706 irq_chip_pm_put(&desc->irq_data);
2707err_out:
2708 kfree(action);
2709
2710 return retval;
2711}
2712
2713/**
2714 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2715 * @irq: Interrupt line to prepare for NMI delivery
2716 *
2717 * This call prepares an interrupt line to deliver NMI on the current CPU,
2718 * before that interrupt line gets enabled with enable_percpu_nmi().
2719 *
2720 * As a CPU local operation, this should be called from non-preemptible
2721 * context.
2722 *
2723 * If the interrupt line cannot be used to deliver NMIs, function
2724 * will fail returning a negative value.
2725 */
2726int prepare_percpu_nmi(unsigned int irq)
2727{
2728 unsigned long flags;
2729 struct irq_desc *desc;
2730 int ret = 0;
2731
2732 WARN_ON(preemptible());
2733
2734 desc = irq_get_desc_lock(irq, &flags,
2735 IRQ_GET_DESC_CHECK_PERCPU);
2736 if (!desc)
2737 return -EINVAL;
2738
2739 if (WARN(!(desc->istate & IRQS_NMI),
2740 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2741 irq)) {
2742 ret = -EINVAL;
2743 goto out;
2744 }
2745
2746 ret = irq_nmi_setup(desc);
2747 if (ret) {
2748 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2749 goto out;
2750 }
2751
2752out:
2753 irq_put_desc_unlock(desc, flags);
2754 return ret;
2755}
2756
2757/**
2758 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2759 * @irq: Interrupt line from which CPU local NMI configuration should be
2760 * removed
2761 *
2762 * This call undoes the setup done by prepare_percpu_nmi().
2763 *
2764 * IRQ line should not be enabled for the current CPU.
2765 *
2766 * As a CPU local operation, this should be called from non-preemptible
2767 * context.
2768 */
2769void teardown_percpu_nmi(unsigned int irq)
2770{
2771 unsigned long flags;
2772 struct irq_desc *desc;
2773
2774 WARN_ON(preemptible());
2775
2776 desc = irq_get_desc_lock(irq, &flags,
2777 IRQ_GET_DESC_CHECK_PERCPU);
2778 if (!desc)
2779 return;
2780
2781 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2782 goto out;
2783
2784 irq_nmi_teardown(desc);
2785out:
2786 irq_put_desc_unlock(desc, flags);
2787}
2788
2789int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2790 bool *state)
2791{
2792 struct irq_chip *chip;
2793 int err = -EINVAL;
2794
2795 do {
2796 chip = irq_data_get_irq_chip(data);
2797 if (WARN_ON_ONCE(!chip))
2798 return -ENODEV;
2799 if (chip->irq_get_irqchip_state)
2800 break;
2801#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2802 data = data->parent_data;
2803#else
2804 data = NULL;
2805#endif
2806 } while (data);
2807
2808 if (data)
2809 err = chip->irq_get_irqchip_state(data, which, state);
2810 return err;
2811}
2812
2813/**
2814 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2815 * @irq: Interrupt line that is forwarded to a VM
2816 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2817 * @state: a pointer to a boolean where the state is to be stored
2818 *
2819 * This call snapshots the internal irqchip state of an
2820 * interrupt, returning into @state the bit corresponding to
2821 * stage @which
2822 *
2823 * This function should be called with preemption disabled if the
2824 * interrupt controller has per-cpu registers.
2825 */
2826int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2827 bool *state)
2828{
2829 struct irq_desc *desc;
2830 struct irq_data *data;
2831 unsigned long flags;
2832 int err = -EINVAL;
2833
2834 desc = irq_get_desc_buslock(irq, &flags, 0);
2835 if (!desc)
2836 return err;
2837
2838 data = irq_desc_get_irq_data(desc);
2839
2840 err = __irq_get_irqchip_state(data, which, state);
2841
2842 irq_put_desc_busunlock(desc, flags);
2843 return err;
2844}
2845EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2846
2847/**
2848 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2849 * @irq: Interrupt line that is forwarded to a VM
2850 * @which: State to be restored (one of IRQCHIP_STATE_*)
2851 * @val: Value corresponding to @which
2852 *
2853 * This call sets the internal irqchip state of an interrupt,
2854 * depending on the value of @which.
2855 *
2856 * This function should be called with migration disabled if the
2857 * interrupt controller has per-cpu registers.
2858 */
2859int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2860 bool val)
2861{
2862 struct irq_desc *desc;
2863 struct irq_data *data;
2864 struct irq_chip *chip;
2865 unsigned long flags;
2866 int err = -EINVAL;
2867
2868 desc = irq_get_desc_buslock(irq, &flags, 0);
2869 if (!desc)
2870 return err;
2871
2872 data = irq_desc_get_irq_data(desc);
2873
2874 do {
2875 chip = irq_data_get_irq_chip(data);
2876 if (WARN_ON_ONCE(!chip)) {
2877 err = -ENODEV;
2878 goto out_unlock;
2879 }
2880 if (chip->irq_set_irqchip_state)
2881 break;
2882#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2883 data = data->parent_data;
2884#else
2885 data = NULL;
2886#endif
2887 } while (data);
2888
2889 if (data)
2890 err = chip->irq_set_irqchip_state(data, which, val);
2891
2892out_unlock:
2893 irq_put_desc_busunlock(desc, flags);
2894 return err;
2895}
2896EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2897
2898/**
2899 * irq_has_action - Check whether an interrupt is requested
2900 * @irq: The linux irq number
2901 *
2902 * Returns: A snapshot of the current state
2903 */
2904bool irq_has_action(unsigned int irq)
2905{
2906 bool res;
2907
2908 rcu_read_lock();
2909 res = irq_desc_has_action(irq_to_desc(irq));
2910 rcu_read_unlock();
2911 return res;
2912}
2913EXPORT_SYMBOL_GPL(irq_has_action);
2914
2915/**
2916 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2917 * @irq: The linux irq number
2918 * @bitmask: The bitmask to evaluate
2919 *
2920 * Returns: True if one of the bits in @bitmask is set
2921 */
2922bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2923{
2924 struct irq_desc *desc;
2925 bool res = false;
2926
2927 rcu_read_lock();
2928 desc = irq_to_desc(irq);
2929 if (desc)
2930 res = !!(desc->status_use_accessors & bitmask);
2931 rcu_read_unlock();
2932 return res;
2933}
2934EXPORT_SYMBOL_GPL(irq_check_status_bit);
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);