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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
29
30static int __init setup_forced_irqthreads(char *arg)
31{
32 static_branch_enable(&force_irqthreads_key);
33 return 0;
34}
35early_param("threadirqs", setup_forced_irqthreads);
36#endif
37
38static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
39{
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
41 bool inprogress;
42
43 do {
44 unsigned long flags;
45
46 /*
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
49 */
50 while (irqd_irq_inprogress(&desc->irq_data))
51 cpu_relax();
52
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
56
57 /*
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
61 */
62 if (!inprogress && sync_chip) {
63 /*
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
66 */
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
68 &inprogress);
69 }
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
71
72 /* Oops, that failed? */
73 } while (inprogress);
74}
75
76/**
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
79 *
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
84 * into account.
85 *
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
88 *
89 * Returns: false if a threaded handler is active.
90 *
91 * This function may be called - with care - from IRQ context.
92 *
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
96 * is the current CPU.
97 */
98bool synchronize_hardirq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
105 }
106
107 return true;
108}
109EXPORT_SYMBOL(synchronize_hardirq);
110
111static void __synchronize_irq(struct irq_desc *desc)
112{
113 __synchronize_hardirq(desc, true);
114 /*
115 * We made sure that no hardirq handler is running. Now verify that no
116 * threaded handlers are active.
117 */
118 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
119}
120
121/**
122 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
123 * @irq: interrupt number to wait for
124 *
125 * This function waits for any pending IRQ handlers for this interrupt
126 * to complete before returning. If you use this function while
127 * holding a resource the IRQ handler may need you will deadlock.
128 *
129 * Can only be called from preemptible code as it might sleep when
130 * an interrupt thread is associated to @irq.
131 *
132 * It optionally makes sure (when the irq chip supports that method)
133 * that the interrupt is not pending in any CPU and waiting for
134 * service.
135 */
136void synchronize_irq(unsigned int irq)
137{
138 struct irq_desc *desc = irq_to_desc(irq);
139
140 if (desc)
141 __synchronize_irq(desc);
142}
143EXPORT_SYMBOL(synchronize_irq);
144
145#ifdef CONFIG_SMP
146cpumask_var_t irq_default_affinity;
147
148static bool __irq_can_set_affinity(struct irq_desc *desc)
149{
150 if (!desc || !irqd_can_balance(&desc->irq_data) ||
151 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
152 return false;
153 return true;
154}
155
156/**
157 * irq_can_set_affinity - Check if the affinity of a given irq can be set
158 * @irq: Interrupt to check
159 *
160 */
161int irq_can_set_affinity(unsigned int irq)
162{
163 return __irq_can_set_affinity(irq_to_desc(irq));
164}
165
166/**
167 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
168 * @irq: Interrupt to check
169 *
170 * Like irq_can_set_affinity() above, but additionally checks for the
171 * AFFINITY_MANAGED flag.
172 */
173bool irq_can_set_affinity_usr(unsigned int irq)
174{
175 struct irq_desc *desc = irq_to_desc(irq);
176
177 return __irq_can_set_affinity(desc) &&
178 !irqd_affinity_is_managed(&desc->irq_data);
179}
180
181/**
182 * irq_set_thread_affinity - Notify irq threads to adjust affinity
183 * @desc: irq descriptor which has affinity changed
184 *
185 * We just set IRQTF_AFFINITY and delegate the affinity setting
186 * to the interrupt thread itself. We can not call
187 * set_cpus_allowed_ptr() here as we hold desc->lock and this
188 * code can be called from hard interrupt context.
189 */
190void irq_set_thread_affinity(struct irq_desc *desc)
191{
192 struct irqaction *action;
193
194 for_each_action_of_desc(desc, action) {
195 if (action->thread)
196 set_bit(IRQTF_AFFINITY, &action->thread_flags);
197 if (action->secondary && action->secondary->thread)
198 set_bit(IRQTF_AFFINITY, &action->secondary->thread_flags);
199 }
200}
201
202#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
203static void irq_validate_effective_affinity(struct irq_data *data)
204{
205 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
206 struct irq_chip *chip = irq_data_get_irq_chip(data);
207
208 if (!cpumask_empty(m))
209 return;
210 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
211 chip->name, data->irq);
212}
213#else
214static inline void irq_validate_effective_affinity(struct irq_data *data) { }
215#endif
216
217int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
218 bool force)
219{
220 struct irq_desc *desc = irq_data_to_desc(data);
221 struct irq_chip *chip = irq_data_get_irq_chip(data);
222 const struct cpumask *prog_mask;
223 int ret;
224
225 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
226 static struct cpumask tmp_mask;
227
228 if (!chip || !chip->irq_set_affinity)
229 return -EINVAL;
230
231 raw_spin_lock(&tmp_mask_lock);
232 /*
233 * If this is a managed interrupt and housekeeping is enabled on
234 * it check whether the requested affinity mask intersects with
235 * a housekeeping CPU. If so, then remove the isolated CPUs from
236 * the mask and just keep the housekeeping CPU(s). This prevents
237 * the affinity setter from routing the interrupt to an isolated
238 * CPU to avoid that I/O submitted from a housekeeping CPU causes
239 * interrupts on an isolated one.
240 *
241 * If the masks do not intersect or include online CPU(s) then
242 * keep the requested mask. The isolated target CPUs are only
243 * receiving interrupts when the I/O operation was submitted
244 * directly from them.
245 *
246 * If all housekeeping CPUs in the affinity mask are offline, the
247 * interrupt will be migrated by the CPU hotplug code once a
248 * housekeeping CPU which belongs to the affinity mask comes
249 * online.
250 */
251 if (irqd_affinity_is_managed(data) &&
252 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
253 const struct cpumask *hk_mask;
254
255 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
256
257 cpumask_and(&tmp_mask, mask, hk_mask);
258 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
259 prog_mask = mask;
260 else
261 prog_mask = &tmp_mask;
262 } else {
263 prog_mask = mask;
264 }
265
266 /*
267 * Make sure we only provide online CPUs to the irqchip,
268 * unless we are being asked to force the affinity (in which
269 * case we do as we are told).
270 */
271 cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
272 if (!force && !cpumask_empty(&tmp_mask))
273 ret = chip->irq_set_affinity(data, &tmp_mask, force);
274 else if (force)
275 ret = chip->irq_set_affinity(data, mask, force);
276 else
277 ret = -EINVAL;
278
279 raw_spin_unlock(&tmp_mask_lock);
280
281 switch (ret) {
282 case IRQ_SET_MASK_OK:
283 case IRQ_SET_MASK_OK_DONE:
284 cpumask_copy(desc->irq_common_data.affinity, mask);
285 fallthrough;
286 case IRQ_SET_MASK_OK_NOCOPY:
287 irq_validate_effective_affinity(data);
288 irq_set_thread_affinity(desc);
289 ret = 0;
290 }
291
292 return ret;
293}
294
295#ifdef CONFIG_GENERIC_PENDING_IRQ
296static inline int irq_set_affinity_pending(struct irq_data *data,
297 const struct cpumask *dest)
298{
299 struct irq_desc *desc = irq_data_to_desc(data);
300
301 irqd_set_move_pending(data);
302 irq_copy_pending(desc, dest);
303 return 0;
304}
305#else
306static inline int irq_set_affinity_pending(struct irq_data *data,
307 const struct cpumask *dest)
308{
309 return -EBUSY;
310}
311#endif
312
313static int irq_try_set_affinity(struct irq_data *data,
314 const struct cpumask *dest, bool force)
315{
316 int ret = irq_do_set_affinity(data, dest, force);
317
318 /*
319 * In case that the underlying vector management is busy and the
320 * architecture supports the generic pending mechanism then utilize
321 * this to avoid returning an error to user space.
322 */
323 if (ret == -EBUSY && !force)
324 ret = irq_set_affinity_pending(data, dest);
325 return ret;
326}
327
328static bool irq_set_affinity_deactivated(struct irq_data *data,
329 const struct cpumask *mask)
330{
331 struct irq_desc *desc = irq_data_to_desc(data);
332
333 /*
334 * Handle irq chips which can handle affinity only in activated
335 * state correctly
336 *
337 * If the interrupt is not yet activated, just store the affinity
338 * mask and do not call the chip driver at all. On activation the
339 * driver has to make sure anyway that the interrupt is in a
340 * usable state so startup works.
341 */
342 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
343 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
344 return false;
345
346 cpumask_copy(desc->irq_common_data.affinity, mask);
347 irq_data_update_effective_affinity(data, mask);
348 irqd_set(data, IRQD_AFFINITY_SET);
349 return true;
350}
351
352int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
353 bool force)
354{
355 struct irq_chip *chip = irq_data_get_irq_chip(data);
356 struct irq_desc *desc = irq_data_to_desc(data);
357 int ret = 0;
358
359 if (!chip || !chip->irq_set_affinity)
360 return -EINVAL;
361
362 if (irq_set_affinity_deactivated(data, mask))
363 return 0;
364
365 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
366 ret = irq_try_set_affinity(data, mask, force);
367 } else {
368 irqd_set_move_pending(data);
369 irq_copy_pending(desc, mask);
370 }
371
372 if (desc->affinity_notify) {
373 kref_get(&desc->affinity_notify->kref);
374 if (!schedule_work(&desc->affinity_notify->work)) {
375 /* Work was already scheduled, drop our extra ref */
376 kref_put(&desc->affinity_notify->kref,
377 desc->affinity_notify->release);
378 }
379 }
380 irqd_set(data, IRQD_AFFINITY_SET);
381
382 return ret;
383}
384
385/**
386 * irq_update_affinity_desc - Update affinity management for an interrupt
387 * @irq: The interrupt number to update
388 * @affinity: Pointer to the affinity descriptor
389 *
390 * This interface can be used to configure the affinity management of
391 * interrupts which have been allocated already.
392 *
393 * There are certain limitations on when it may be used - attempts to use it
394 * for when the kernel is configured for generic IRQ reservation mode (in
395 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
396 * managed/non-managed interrupt accounting. In addition, attempts to use it on
397 * an interrupt which is already started or which has already been configured
398 * as managed will also fail, as these mean invalid init state or double init.
399 */
400int irq_update_affinity_desc(unsigned int irq,
401 struct irq_affinity_desc *affinity)
402{
403 struct irq_desc *desc;
404 unsigned long flags;
405 bool activated;
406 int ret = 0;
407
408 /*
409 * Supporting this with the reservation scheme used by x86 needs
410 * some more thought. Fail it for now.
411 */
412 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
413 return -EOPNOTSUPP;
414
415 desc = irq_get_desc_buslock(irq, &flags, 0);
416 if (!desc)
417 return -EINVAL;
418
419 /* Requires the interrupt to be shut down */
420 if (irqd_is_started(&desc->irq_data)) {
421 ret = -EBUSY;
422 goto out_unlock;
423 }
424
425 /* Interrupts which are already managed cannot be modified */
426 if (irqd_affinity_is_managed(&desc->irq_data)) {
427 ret = -EBUSY;
428 goto out_unlock;
429 }
430
431 /*
432 * Deactivate the interrupt. That's required to undo
433 * anything an earlier activation has established.
434 */
435 activated = irqd_is_activated(&desc->irq_data);
436 if (activated)
437 irq_domain_deactivate_irq(&desc->irq_data);
438
439 if (affinity->is_managed) {
440 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
441 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
442 }
443
444 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
445
446 /* Restore the activation state */
447 if (activated)
448 irq_domain_activate_irq(&desc->irq_data, false);
449
450out_unlock:
451 irq_put_desc_busunlock(desc, flags);
452 return ret;
453}
454
455static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
456 bool force)
457{
458 struct irq_desc *desc = irq_to_desc(irq);
459 unsigned long flags;
460 int ret;
461
462 if (!desc)
463 return -EINVAL;
464
465 raw_spin_lock_irqsave(&desc->lock, flags);
466 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
467 raw_spin_unlock_irqrestore(&desc->lock, flags);
468 return ret;
469}
470
471/**
472 * irq_set_affinity - Set the irq affinity of a given irq
473 * @irq: Interrupt to set affinity
474 * @cpumask: cpumask
475 *
476 * Fails if cpumask does not contain an online CPU
477 */
478int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
479{
480 return __irq_set_affinity(irq, cpumask, false);
481}
482EXPORT_SYMBOL_GPL(irq_set_affinity);
483
484/**
485 * irq_force_affinity - Force the irq affinity of a given irq
486 * @irq: Interrupt to set affinity
487 * @cpumask: cpumask
488 *
489 * Same as irq_set_affinity, but without checking the mask against
490 * online cpus.
491 *
492 * Solely for low level cpu hotplug code, where we need to make per
493 * cpu interrupts affine before the cpu becomes online.
494 */
495int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
496{
497 return __irq_set_affinity(irq, cpumask, true);
498}
499EXPORT_SYMBOL_GPL(irq_force_affinity);
500
501int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
502 bool setaffinity)
503{
504 unsigned long flags;
505 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
506
507 if (!desc)
508 return -EINVAL;
509 desc->affinity_hint = m;
510 irq_put_desc_unlock(desc, flags);
511 if (m && setaffinity)
512 __irq_set_affinity(irq, m, false);
513 return 0;
514}
515EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
516
517static void irq_affinity_notify(struct work_struct *work)
518{
519 struct irq_affinity_notify *notify =
520 container_of(work, struct irq_affinity_notify, work);
521 struct irq_desc *desc = irq_to_desc(notify->irq);
522 cpumask_var_t cpumask;
523 unsigned long flags;
524
525 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
526 goto out;
527
528 raw_spin_lock_irqsave(&desc->lock, flags);
529 if (irq_move_pending(&desc->irq_data))
530 irq_get_pending(cpumask, desc);
531 else
532 cpumask_copy(cpumask, desc->irq_common_data.affinity);
533 raw_spin_unlock_irqrestore(&desc->lock, flags);
534
535 notify->notify(notify, cpumask);
536
537 free_cpumask_var(cpumask);
538out:
539 kref_put(¬ify->kref, notify->release);
540}
541
542/**
543 * irq_set_affinity_notifier - control notification of IRQ affinity changes
544 * @irq: Interrupt for which to enable/disable notification
545 * @notify: Context for notification, or %NULL to disable
546 * notification. Function pointers must be initialised;
547 * the other fields will be initialised by this function.
548 *
549 * Must be called in process context. Notification may only be enabled
550 * after the IRQ is allocated and must be disabled before the IRQ is
551 * freed using free_irq().
552 */
553int
554irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
555{
556 struct irq_desc *desc = irq_to_desc(irq);
557 struct irq_affinity_notify *old_notify;
558 unsigned long flags;
559
560 /* The release function is promised process context */
561 might_sleep();
562
563 if (!desc || desc->istate & IRQS_NMI)
564 return -EINVAL;
565
566 /* Complete initialisation of *notify */
567 if (notify) {
568 notify->irq = irq;
569 kref_init(¬ify->kref);
570 INIT_WORK(¬ify->work, irq_affinity_notify);
571 }
572
573 raw_spin_lock_irqsave(&desc->lock, flags);
574 old_notify = desc->affinity_notify;
575 desc->affinity_notify = notify;
576 raw_spin_unlock_irqrestore(&desc->lock, flags);
577
578 if (old_notify) {
579 if (cancel_work_sync(&old_notify->work)) {
580 /* Pending work had a ref, put that one too */
581 kref_put(&old_notify->kref, old_notify->release);
582 }
583 kref_put(&old_notify->kref, old_notify->release);
584 }
585
586 return 0;
587}
588EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
589
590#ifndef CONFIG_AUTO_IRQ_AFFINITY
591/*
592 * Generic version of the affinity autoselector.
593 */
594int irq_setup_affinity(struct irq_desc *desc)
595{
596 struct cpumask *set = irq_default_affinity;
597 int ret, node = irq_desc_get_node(desc);
598 static DEFINE_RAW_SPINLOCK(mask_lock);
599 static struct cpumask mask;
600
601 /* Excludes PER_CPU and NO_BALANCE interrupts */
602 if (!__irq_can_set_affinity(desc))
603 return 0;
604
605 raw_spin_lock(&mask_lock);
606 /*
607 * Preserve the managed affinity setting and a userspace affinity
608 * setup, but make sure that one of the targets is online.
609 */
610 if (irqd_affinity_is_managed(&desc->irq_data) ||
611 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
612 if (cpumask_intersects(desc->irq_common_data.affinity,
613 cpu_online_mask))
614 set = desc->irq_common_data.affinity;
615 else
616 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
617 }
618
619 cpumask_and(&mask, cpu_online_mask, set);
620 if (cpumask_empty(&mask))
621 cpumask_copy(&mask, cpu_online_mask);
622
623 if (node != NUMA_NO_NODE) {
624 const struct cpumask *nodemask = cpumask_of_node(node);
625
626 /* make sure at least one of the cpus in nodemask is online */
627 if (cpumask_intersects(&mask, nodemask))
628 cpumask_and(&mask, &mask, nodemask);
629 }
630 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
631 raw_spin_unlock(&mask_lock);
632 return ret;
633}
634#else
635/* Wrapper for ALPHA specific affinity selector magic */
636int irq_setup_affinity(struct irq_desc *desc)
637{
638 return irq_select_affinity(irq_desc_get_irq(desc));
639}
640#endif /* CONFIG_AUTO_IRQ_AFFINITY */
641#endif /* CONFIG_SMP */
642
643
644/**
645 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
646 * @irq: interrupt number to set affinity
647 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
648 * specific data for percpu_devid interrupts
649 *
650 * This function uses the vCPU specific data to set the vCPU
651 * affinity for an irq. The vCPU specific data is passed from
652 * outside, such as KVM. One example code path is as below:
653 * KVM -> IOMMU -> irq_set_vcpu_affinity().
654 */
655int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
656{
657 unsigned long flags;
658 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
659 struct irq_data *data;
660 struct irq_chip *chip;
661 int ret = -ENOSYS;
662
663 if (!desc)
664 return -EINVAL;
665
666 data = irq_desc_get_irq_data(desc);
667 do {
668 chip = irq_data_get_irq_chip(data);
669 if (chip && chip->irq_set_vcpu_affinity)
670 break;
671#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
672 data = data->parent_data;
673#else
674 data = NULL;
675#endif
676 } while (data);
677
678 if (data)
679 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
680 irq_put_desc_unlock(desc, flags);
681
682 return ret;
683}
684EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
685
686void __disable_irq(struct irq_desc *desc)
687{
688 if (!desc->depth++)
689 irq_disable(desc);
690}
691
692static int __disable_irq_nosync(unsigned int irq)
693{
694 unsigned long flags;
695 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
696
697 if (!desc)
698 return -EINVAL;
699 __disable_irq(desc);
700 irq_put_desc_busunlock(desc, flags);
701 return 0;
702}
703
704/**
705 * disable_irq_nosync - disable an irq without waiting
706 * @irq: Interrupt to disable
707 *
708 * Disable the selected interrupt line. Disables and Enables are
709 * nested.
710 * Unlike disable_irq(), this function does not ensure existing
711 * instances of the IRQ handler have completed before returning.
712 *
713 * This function may be called from IRQ context.
714 */
715void disable_irq_nosync(unsigned int irq)
716{
717 __disable_irq_nosync(irq);
718}
719EXPORT_SYMBOL(disable_irq_nosync);
720
721/**
722 * disable_irq - disable an irq and wait for completion
723 * @irq: Interrupt to disable
724 *
725 * Disable the selected interrupt line. Enables and Disables are
726 * nested.
727 * This function waits for any pending IRQ handlers for this interrupt
728 * to complete before returning. If you use this function while
729 * holding a resource the IRQ handler may need you will deadlock.
730 *
731 * Can only be called from preemptible code as it might sleep when
732 * an interrupt thread is associated to @irq.
733 *
734 */
735void disable_irq(unsigned int irq)
736{
737 might_sleep();
738 if (!__disable_irq_nosync(irq))
739 synchronize_irq(irq);
740}
741EXPORT_SYMBOL(disable_irq);
742
743/**
744 * disable_hardirq - disables an irq and waits for hardirq completion
745 * @irq: Interrupt to disable
746 *
747 * Disable the selected interrupt line. Enables and Disables are
748 * nested.
749 * This function waits for any pending hard IRQ handlers for this
750 * interrupt to complete before returning. If you use this function while
751 * holding a resource the hard IRQ handler may need you will deadlock.
752 *
753 * When used to optimistically disable an interrupt from atomic context
754 * the return value must be checked.
755 *
756 * Returns: false if a threaded handler is active.
757 *
758 * This function may be called - with care - from IRQ context.
759 */
760bool disable_hardirq(unsigned int irq)
761{
762 if (!__disable_irq_nosync(irq))
763 return synchronize_hardirq(irq);
764
765 return false;
766}
767EXPORT_SYMBOL_GPL(disable_hardirq);
768
769/**
770 * disable_nmi_nosync - disable an nmi without waiting
771 * @irq: Interrupt to disable
772 *
773 * Disable the selected interrupt line. Disables and enables are
774 * nested.
775 * The interrupt to disable must have been requested through request_nmi.
776 * Unlike disable_nmi(), this function does not ensure existing
777 * instances of the IRQ handler have completed before returning.
778 */
779void disable_nmi_nosync(unsigned int irq)
780{
781 disable_irq_nosync(irq);
782}
783
784void __enable_irq(struct irq_desc *desc)
785{
786 switch (desc->depth) {
787 case 0:
788 err_out:
789 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
790 irq_desc_get_irq(desc));
791 break;
792 case 1: {
793 if (desc->istate & IRQS_SUSPENDED)
794 goto err_out;
795 /* Prevent probing on this irq: */
796 irq_settings_set_noprobe(desc);
797 /*
798 * Call irq_startup() not irq_enable() here because the
799 * interrupt might be marked NOAUTOEN. So irq_startup()
800 * needs to be invoked when it gets enabled the first
801 * time. If it was already started up, then irq_startup()
802 * will invoke irq_enable() under the hood.
803 */
804 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
805 break;
806 }
807 default:
808 desc->depth--;
809 }
810}
811
812/**
813 * enable_irq - enable handling of an irq
814 * @irq: Interrupt to enable
815 *
816 * Undoes the effect of one call to disable_irq(). If this
817 * matches the last disable, processing of interrupts on this
818 * IRQ line is re-enabled.
819 *
820 * This function may be called from IRQ context only when
821 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
822 */
823void enable_irq(unsigned int irq)
824{
825 unsigned long flags;
826 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
827
828 if (!desc)
829 return;
830 if (WARN(!desc->irq_data.chip,
831 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
832 goto out;
833
834 __enable_irq(desc);
835out:
836 irq_put_desc_busunlock(desc, flags);
837}
838EXPORT_SYMBOL(enable_irq);
839
840/**
841 * enable_nmi - enable handling of an nmi
842 * @irq: Interrupt to enable
843 *
844 * The interrupt to enable must have been requested through request_nmi.
845 * Undoes the effect of one call to disable_nmi(). If this
846 * matches the last disable, processing of interrupts on this
847 * IRQ line is re-enabled.
848 */
849void enable_nmi(unsigned int irq)
850{
851 enable_irq(irq);
852}
853
854static int set_irq_wake_real(unsigned int irq, unsigned int on)
855{
856 struct irq_desc *desc = irq_to_desc(irq);
857 int ret = -ENXIO;
858
859 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
860 return 0;
861
862 if (desc->irq_data.chip->irq_set_wake)
863 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
864
865 return ret;
866}
867
868/**
869 * irq_set_irq_wake - control irq power management wakeup
870 * @irq: interrupt to control
871 * @on: enable/disable power management wakeup
872 *
873 * Enable/disable power management wakeup mode, which is
874 * disabled by default. Enables and disables must match,
875 * just as they match for non-wakeup mode support.
876 *
877 * Wakeup mode lets this IRQ wake the system from sleep
878 * states like "suspend to RAM".
879 *
880 * Note: irq enable/disable state is completely orthogonal
881 * to the enable/disable state of irq wake. An irq can be
882 * disabled with disable_irq() and still wake the system as
883 * long as the irq has wake enabled. If this does not hold,
884 * then the underlying irq chip and the related driver need
885 * to be investigated.
886 */
887int irq_set_irq_wake(unsigned int irq, unsigned int on)
888{
889 unsigned long flags;
890 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
891 int ret = 0;
892
893 if (!desc)
894 return -EINVAL;
895
896 /* Don't use NMIs as wake up interrupts please */
897 if (desc->istate & IRQS_NMI) {
898 ret = -EINVAL;
899 goto out_unlock;
900 }
901
902 /* wakeup-capable irqs can be shared between drivers that
903 * don't need to have the same sleep mode behaviors.
904 */
905 if (on) {
906 if (desc->wake_depth++ == 0) {
907 ret = set_irq_wake_real(irq, on);
908 if (ret)
909 desc->wake_depth = 0;
910 else
911 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
912 }
913 } else {
914 if (desc->wake_depth == 0) {
915 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
916 } else if (--desc->wake_depth == 0) {
917 ret = set_irq_wake_real(irq, on);
918 if (ret)
919 desc->wake_depth = 1;
920 else
921 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
922 }
923 }
924
925out_unlock:
926 irq_put_desc_busunlock(desc, flags);
927 return ret;
928}
929EXPORT_SYMBOL(irq_set_irq_wake);
930
931/*
932 * Internal function that tells the architecture code whether a
933 * particular irq has been exclusively allocated or is available
934 * for driver use.
935 */
936int can_request_irq(unsigned int irq, unsigned long irqflags)
937{
938 unsigned long flags;
939 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
940 int canrequest = 0;
941
942 if (!desc)
943 return 0;
944
945 if (irq_settings_can_request(desc)) {
946 if (!desc->action ||
947 irqflags & desc->action->flags & IRQF_SHARED)
948 canrequest = 1;
949 }
950 irq_put_desc_unlock(desc, flags);
951 return canrequest;
952}
953
954int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
955{
956 struct irq_chip *chip = desc->irq_data.chip;
957 int ret, unmask = 0;
958
959 if (!chip || !chip->irq_set_type) {
960 /*
961 * IRQF_TRIGGER_* but the PIC does not support multiple
962 * flow-types?
963 */
964 pr_debug("No set_type function for IRQ %d (%s)\n",
965 irq_desc_get_irq(desc),
966 chip ? (chip->name ? : "unknown") : "unknown");
967 return 0;
968 }
969
970 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
971 if (!irqd_irq_masked(&desc->irq_data))
972 mask_irq(desc);
973 if (!irqd_irq_disabled(&desc->irq_data))
974 unmask = 1;
975 }
976
977 /* Mask all flags except trigger mode */
978 flags &= IRQ_TYPE_SENSE_MASK;
979 ret = chip->irq_set_type(&desc->irq_data, flags);
980
981 switch (ret) {
982 case IRQ_SET_MASK_OK:
983 case IRQ_SET_MASK_OK_DONE:
984 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
985 irqd_set(&desc->irq_data, flags);
986 fallthrough;
987
988 case IRQ_SET_MASK_OK_NOCOPY:
989 flags = irqd_get_trigger_type(&desc->irq_data);
990 irq_settings_set_trigger_mask(desc, flags);
991 irqd_clear(&desc->irq_data, IRQD_LEVEL);
992 irq_settings_clr_level(desc);
993 if (flags & IRQ_TYPE_LEVEL_MASK) {
994 irq_settings_set_level(desc);
995 irqd_set(&desc->irq_data, IRQD_LEVEL);
996 }
997
998 ret = 0;
999 break;
1000 default:
1001 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
1002 flags, irq_desc_get_irq(desc), chip->irq_set_type);
1003 }
1004 if (unmask)
1005 unmask_irq(desc);
1006 return ret;
1007}
1008
1009#ifdef CONFIG_HARDIRQS_SW_RESEND
1010int irq_set_parent(int irq, int parent_irq)
1011{
1012 unsigned long flags;
1013 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1014
1015 if (!desc)
1016 return -EINVAL;
1017
1018 desc->parent_irq = parent_irq;
1019
1020 irq_put_desc_unlock(desc, flags);
1021 return 0;
1022}
1023EXPORT_SYMBOL_GPL(irq_set_parent);
1024#endif
1025
1026/*
1027 * Default primary interrupt handler for threaded interrupts. Is
1028 * assigned as primary handler when request_threaded_irq is called
1029 * with handler == NULL. Useful for oneshot interrupts.
1030 */
1031static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1032{
1033 return IRQ_WAKE_THREAD;
1034}
1035
1036/*
1037 * Primary handler for nested threaded interrupts. Should never be
1038 * called.
1039 */
1040static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1041{
1042 WARN(1, "Primary handler called for nested irq %d\n", irq);
1043 return IRQ_NONE;
1044}
1045
1046static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1047{
1048 WARN(1, "Secondary action handler called for irq %d\n", irq);
1049 return IRQ_NONE;
1050}
1051
1052static int irq_wait_for_interrupt(struct irqaction *action)
1053{
1054 for (;;) {
1055 set_current_state(TASK_INTERRUPTIBLE);
1056
1057 if (kthread_should_stop()) {
1058 /* may need to run one last time */
1059 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1060 &action->thread_flags)) {
1061 __set_current_state(TASK_RUNNING);
1062 return 0;
1063 }
1064 __set_current_state(TASK_RUNNING);
1065 return -1;
1066 }
1067
1068 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1069 &action->thread_flags)) {
1070 __set_current_state(TASK_RUNNING);
1071 return 0;
1072 }
1073 schedule();
1074 }
1075}
1076
1077/*
1078 * Oneshot interrupts keep the irq line masked until the threaded
1079 * handler finished. unmask if the interrupt has not been disabled and
1080 * is marked MASKED.
1081 */
1082static void irq_finalize_oneshot(struct irq_desc *desc,
1083 struct irqaction *action)
1084{
1085 if (!(desc->istate & IRQS_ONESHOT) ||
1086 action->handler == irq_forced_secondary_handler)
1087 return;
1088again:
1089 chip_bus_lock(desc);
1090 raw_spin_lock_irq(&desc->lock);
1091
1092 /*
1093 * Implausible though it may be we need to protect us against
1094 * the following scenario:
1095 *
1096 * The thread is faster done than the hard interrupt handler
1097 * on the other CPU. If we unmask the irq line then the
1098 * interrupt can come in again and masks the line, leaves due
1099 * to IRQS_INPROGRESS and the irq line is masked forever.
1100 *
1101 * This also serializes the state of shared oneshot handlers
1102 * versus "desc->threads_oneshot |= action->thread_mask;" in
1103 * irq_wake_thread(). See the comment there which explains the
1104 * serialization.
1105 */
1106 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1107 raw_spin_unlock_irq(&desc->lock);
1108 chip_bus_sync_unlock(desc);
1109 cpu_relax();
1110 goto again;
1111 }
1112
1113 /*
1114 * Now check again, whether the thread should run. Otherwise
1115 * we would clear the threads_oneshot bit of this thread which
1116 * was just set.
1117 */
1118 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1119 goto out_unlock;
1120
1121 desc->threads_oneshot &= ~action->thread_mask;
1122
1123 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1124 irqd_irq_masked(&desc->irq_data))
1125 unmask_threaded_irq(desc);
1126
1127out_unlock:
1128 raw_spin_unlock_irq(&desc->lock);
1129 chip_bus_sync_unlock(desc);
1130}
1131
1132#ifdef CONFIG_SMP
1133/*
1134 * Check whether we need to change the affinity of the interrupt thread.
1135 */
1136static void
1137irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1138{
1139 cpumask_var_t mask;
1140 bool valid = true;
1141
1142 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1143 return;
1144
1145 /*
1146 * In case we are out of memory we set IRQTF_AFFINITY again and
1147 * try again next time
1148 */
1149 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1150 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1151 return;
1152 }
1153
1154 raw_spin_lock_irq(&desc->lock);
1155 /*
1156 * This code is triggered unconditionally. Check the affinity
1157 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1158 */
1159 if (cpumask_available(desc->irq_common_data.affinity)) {
1160 const struct cpumask *m;
1161
1162 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1163 cpumask_copy(mask, m);
1164 } else {
1165 valid = false;
1166 }
1167 raw_spin_unlock_irq(&desc->lock);
1168
1169 if (valid)
1170 set_cpus_allowed_ptr(current, mask);
1171 free_cpumask_var(mask);
1172}
1173#else
1174static inline void
1175irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1176#endif
1177
1178/*
1179 * Interrupts which are not explicitly requested as threaded
1180 * interrupts rely on the implicit bh/preempt disable of the hard irq
1181 * context. So we need to disable bh here to avoid deadlocks and other
1182 * side effects.
1183 */
1184static irqreturn_t
1185irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1186{
1187 irqreturn_t ret;
1188
1189 local_bh_disable();
1190 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1191 local_irq_disable();
1192 ret = action->thread_fn(action->irq, action->dev_id);
1193 if (ret == IRQ_HANDLED)
1194 atomic_inc(&desc->threads_handled);
1195
1196 irq_finalize_oneshot(desc, action);
1197 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1198 local_irq_enable();
1199 local_bh_enable();
1200 return ret;
1201}
1202
1203/*
1204 * Interrupts explicitly requested as threaded interrupts want to be
1205 * preemptible - many of them need to sleep and wait for slow busses to
1206 * complete.
1207 */
1208static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1209 struct irqaction *action)
1210{
1211 irqreturn_t ret;
1212
1213 ret = action->thread_fn(action->irq, action->dev_id);
1214 if (ret == IRQ_HANDLED)
1215 atomic_inc(&desc->threads_handled);
1216
1217 irq_finalize_oneshot(desc, action);
1218 return ret;
1219}
1220
1221void wake_threads_waitq(struct irq_desc *desc)
1222{
1223 if (atomic_dec_and_test(&desc->threads_active))
1224 wake_up(&desc->wait_for_threads);
1225}
1226
1227static void irq_thread_dtor(struct callback_head *unused)
1228{
1229 struct task_struct *tsk = current;
1230 struct irq_desc *desc;
1231 struct irqaction *action;
1232
1233 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1234 return;
1235
1236 action = kthread_data(tsk);
1237
1238 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1239 tsk->comm, tsk->pid, action->irq);
1240
1241
1242 desc = irq_to_desc(action->irq);
1243 /*
1244 * If IRQTF_RUNTHREAD is set, we need to decrement
1245 * desc->threads_active and wake possible waiters.
1246 */
1247 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1248 wake_threads_waitq(desc);
1249
1250 /* Prevent a stale desc->threads_oneshot */
1251 irq_finalize_oneshot(desc, action);
1252}
1253
1254static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1255{
1256 struct irqaction *secondary = action->secondary;
1257
1258 if (WARN_ON_ONCE(!secondary))
1259 return;
1260
1261 raw_spin_lock_irq(&desc->lock);
1262 __irq_wake_thread(desc, secondary);
1263 raw_spin_unlock_irq(&desc->lock);
1264}
1265
1266/*
1267 * Internal function to notify that a interrupt thread is ready.
1268 */
1269static void irq_thread_set_ready(struct irq_desc *desc,
1270 struct irqaction *action)
1271{
1272 set_bit(IRQTF_READY, &action->thread_flags);
1273 wake_up(&desc->wait_for_threads);
1274}
1275
1276/*
1277 * Internal function to wake up a interrupt thread and wait until it is
1278 * ready.
1279 */
1280static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1281 struct irqaction *action)
1282{
1283 if (!action || !action->thread)
1284 return;
1285
1286 wake_up_process(action->thread);
1287 wait_event(desc->wait_for_threads,
1288 test_bit(IRQTF_READY, &action->thread_flags));
1289}
1290
1291/*
1292 * Interrupt handler thread
1293 */
1294static int irq_thread(void *data)
1295{
1296 struct callback_head on_exit_work;
1297 struct irqaction *action = data;
1298 struct irq_desc *desc = irq_to_desc(action->irq);
1299 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1300 struct irqaction *action);
1301
1302 irq_thread_set_ready(desc, action);
1303
1304 sched_set_fifo(current);
1305
1306 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1307 &action->thread_flags))
1308 handler_fn = irq_forced_thread_fn;
1309 else
1310 handler_fn = irq_thread_fn;
1311
1312 init_task_work(&on_exit_work, irq_thread_dtor);
1313 task_work_add(current, &on_exit_work, TWA_NONE);
1314
1315 irq_thread_check_affinity(desc, action);
1316
1317 while (!irq_wait_for_interrupt(action)) {
1318 irqreturn_t action_ret;
1319
1320 irq_thread_check_affinity(desc, action);
1321
1322 action_ret = handler_fn(desc, action);
1323 if (action_ret == IRQ_WAKE_THREAD)
1324 irq_wake_secondary(desc, action);
1325
1326 wake_threads_waitq(desc);
1327 }
1328
1329 /*
1330 * This is the regular exit path. __free_irq() is stopping the
1331 * thread via kthread_stop() after calling
1332 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1333 * oneshot mask bit can be set.
1334 */
1335 task_work_cancel(current, irq_thread_dtor);
1336 return 0;
1337}
1338
1339/**
1340 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1341 * @irq: Interrupt line
1342 * @dev_id: Device identity for which the thread should be woken
1343 *
1344 */
1345void irq_wake_thread(unsigned int irq, void *dev_id)
1346{
1347 struct irq_desc *desc = irq_to_desc(irq);
1348 struct irqaction *action;
1349 unsigned long flags;
1350
1351 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1352 return;
1353
1354 raw_spin_lock_irqsave(&desc->lock, flags);
1355 for_each_action_of_desc(desc, action) {
1356 if (action->dev_id == dev_id) {
1357 if (action->thread)
1358 __irq_wake_thread(desc, action);
1359 break;
1360 }
1361 }
1362 raw_spin_unlock_irqrestore(&desc->lock, flags);
1363}
1364EXPORT_SYMBOL_GPL(irq_wake_thread);
1365
1366static int irq_setup_forced_threading(struct irqaction *new)
1367{
1368 if (!force_irqthreads())
1369 return 0;
1370 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1371 return 0;
1372
1373 /*
1374 * No further action required for interrupts which are requested as
1375 * threaded interrupts already
1376 */
1377 if (new->handler == irq_default_primary_handler)
1378 return 0;
1379
1380 new->flags |= IRQF_ONESHOT;
1381
1382 /*
1383 * Handle the case where we have a real primary handler and a
1384 * thread handler. We force thread them as well by creating a
1385 * secondary action.
1386 */
1387 if (new->handler && new->thread_fn) {
1388 /* Allocate the secondary action */
1389 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1390 if (!new->secondary)
1391 return -ENOMEM;
1392 new->secondary->handler = irq_forced_secondary_handler;
1393 new->secondary->thread_fn = new->thread_fn;
1394 new->secondary->dev_id = new->dev_id;
1395 new->secondary->irq = new->irq;
1396 new->secondary->name = new->name;
1397 }
1398 /* Deal with the primary handler */
1399 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1400 new->thread_fn = new->handler;
1401 new->handler = irq_default_primary_handler;
1402 return 0;
1403}
1404
1405static int irq_request_resources(struct irq_desc *desc)
1406{
1407 struct irq_data *d = &desc->irq_data;
1408 struct irq_chip *c = d->chip;
1409
1410 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1411}
1412
1413static void irq_release_resources(struct irq_desc *desc)
1414{
1415 struct irq_data *d = &desc->irq_data;
1416 struct irq_chip *c = d->chip;
1417
1418 if (c->irq_release_resources)
1419 c->irq_release_resources(d);
1420}
1421
1422static bool irq_supports_nmi(struct irq_desc *desc)
1423{
1424 struct irq_data *d = irq_desc_get_irq_data(desc);
1425
1426#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1427 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1428 if (d->parent_data)
1429 return false;
1430#endif
1431 /* Don't support NMIs for chips behind a slow bus */
1432 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1433 return false;
1434
1435 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1436}
1437
1438static int irq_nmi_setup(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 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1444}
1445
1446static void irq_nmi_teardown(struct irq_desc *desc)
1447{
1448 struct irq_data *d = irq_desc_get_irq_data(desc);
1449 struct irq_chip *c = d->chip;
1450
1451 if (c->irq_nmi_teardown)
1452 c->irq_nmi_teardown(d);
1453}
1454
1455static int
1456setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1457{
1458 struct task_struct *t;
1459
1460 if (!secondary) {
1461 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1462 new->name);
1463 } else {
1464 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1465 new->name);
1466 }
1467
1468 if (IS_ERR(t))
1469 return PTR_ERR(t);
1470
1471 /*
1472 * We keep the reference to the task struct even if
1473 * the thread dies to avoid that the interrupt code
1474 * references an already freed task_struct.
1475 */
1476 new->thread = get_task_struct(t);
1477 /*
1478 * Tell the thread to set its affinity. This is
1479 * important for shared interrupt handlers as we do
1480 * not invoke setup_affinity() for the secondary
1481 * handlers as everything is already set up. Even for
1482 * interrupts marked with IRQF_NO_BALANCE this is
1483 * correct as we want the thread to move to the cpu(s)
1484 * on which the requesting code placed the interrupt.
1485 */
1486 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1487 return 0;
1488}
1489
1490/*
1491 * Internal function to register an irqaction - typically used to
1492 * allocate special interrupts that are part of the architecture.
1493 *
1494 * Locking rules:
1495 *
1496 * desc->request_mutex Provides serialization against a concurrent free_irq()
1497 * chip_bus_lock Provides serialization for slow bus operations
1498 * desc->lock Provides serialization against hard interrupts
1499 *
1500 * chip_bus_lock and desc->lock are sufficient for all other management and
1501 * interrupt related functions. desc->request_mutex solely serializes
1502 * request/free_irq().
1503 */
1504static int
1505__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1506{
1507 struct irqaction *old, **old_ptr;
1508 unsigned long flags, thread_mask = 0;
1509 int ret, nested, shared = 0;
1510
1511 if (!desc)
1512 return -EINVAL;
1513
1514 if (desc->irq_data.chip == &no_irq_chip)
1515 return -ENOSYS;
1516 if (!try_module_get(desc->owner))
1517 return -ENODEV;
1518
1519 new->irq = irq;
1520
1521 /*
1522 * If the trigger type is not specified by the caller,
1523 * then use the default for this interrupt.
1524 */
1525 if (!(new->flags & IRQF_TRIGGER_MASK))
1526 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1527
1528 /*
1529 * Check whether the interrupt nests into another interrupt
1530 * thread.
1531 */
1532 nested = irq_settings_is_nested_thread(desc);
1533 if (nested) {
1534 if (!new->thread_fn) {
1535 ret = -EINVAL;
1536 goto out_mput;
1537 }
1538 /*
1539 * Replace the primary handler which was provided from
1540 * the driver for non nested interrupt handling by the
1541 * dummy function which warns when called.
1542 */
1543 new->handler = irq_nested_primary_handler;
1544 } else {
1545 if (irq_settings_can_thread(desc)) {
1546 ret = irq_setup_forced_threading(new);
1547 if (ret)
1548 goto out_mput;
1549 }
1550 }
1551
1552 /*
1553 * Create a handler thread when a thread function is supplied
1554 * and the interrupt does not nest into another interrupt
1555 * thread.
1556 */
1557 if (new->thread_fn && !nested) {
1558 ret = setup_irq_thread(new, irq, false);
1559 if (ret)
1560 goto out_mput;
1561 if (new->secondary) {
1562 ret = setup_irq_thread(new->secondary, irq, true);
1563 if (ret)
1564 goto out_thread;
1565 }
1566 }
1567
1568 /*
1569 * Drivers are often written to work w/o knowledge about the
1570 * underlying irq chip implementation, so a request for a
1571 * threaded irq without a primary hard irq context handler
1572 * requires the ONESHOT flag to be set. Some irq chips like
1573 * MSI based interrupts are per se one shot safe. Check the
1574 * chip flags, so we can avoid the unmask dance at the end of
1575 * the threaded handler for those.
1576 */
1577 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1578 new->flags &= ~IRQF_ONESHOT;
1579
1580 /*
1581 * Protects against a concurrent __free_irq() call which might wait
1582 * for synchronize_hardirq() to complete without holding the optional
1583 * chip bus lock and desc->lock. Also protects against handing out
1584 * a recycled oneshot thread_mask bit while it's still in use by
1585 * its previous owner.
1586 */
1587 mutex_lock(&desc->request_mutex);
1588
1589 /*
1590 * Acquire bus lock as the irq_request_resources() callback below
1591 * might rely on the serialization or the magic power management
1592 * functions which are abusing the irq_bus_lock() callback,
1593 */
1594 chip_bus_lock(desc);
1595
1596 /* First installed action requests resources. */
1597 if (!desc->action) {
1598 ret = irq_request_resources(desc);
1599 if (ret) {
1600 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1601 new->name, irq, desc->irq_data.chip->name);
1602 goto out_bus_unlock;
1603 }
1604 }
1605
1606 /*
1607 * The following block of code has to be executed atomically
1608 * protected against a concurrent interrupt and any of the other
1609 * management calls which are not serialized via
1610 * desc->request_mutex or the optional bus lock.
1611 */
1612 raw_spin_lock_irqsave(&desc->lock, flags);
1613 old_ptr = &desc->action;
1614 old = *old_ptr;
1615 if (old) {
1616 /*
1617 * Can't share interrupts unless both agree to and are
1618 * the same type (level, edge, polarity). So both flag
1619 * fields must have IRQF_SHARED set and the bits which
1620 * set the trigger type must match. Also all must
1621 * agree on ONESHOT.
1622 * Interrupt lines used for NMIs cannot be shared.
1623 */
1624 unsigned int oldtype;
1625
1626 if (desc->istate & IRQS_NMI) {
1627 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1628 new->name, irq, desc->irq_data.chip->name);
1629 ret = -EINVAL;
1630 goto out_unlock;
1631 }
1632
1633 /*
1634 * If nobody did set the configuration before, inherit
1635 * the one provided by the requester.
1636 */
1637 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1638 oldtype = irqd_get_trigger_type(&desc->irq_data);
1639 } else {
1640 oldtype = new->flags & IRQF_TRIGGER_MASK;
1641 irqd_set_trigger_type(&desc->irq_data, oldtype);
1642 }
1643
1644 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1645 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1646 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1647 goto mismatch;
1648
1649 /* All handlers must agree on per-cpuness */
1650 if ((old->flags & IRQF_PERCPU) !=
1651 (new->flags & IRQF_PERCPU))
1652 goto mismatch;
1653
1654 /* add new interrupt at end of irq queue */
1655 do {
1656 /*
1657 * Or all existing action->thread_mask bits,
1658 * so we can find the next zero bit for this
1659 * new action.
1660 */
1661 thread_mask |= old->thread_mask;
1662 old_ptr = &old->next;
1663 old = *old_ptr;
1664 } while (old);
1665 shared = 1;
1666 }
1667
1668 /*
1669 * Setup the thread mask for this irqaction for ONESHOT. For
1670 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1671 * conditional in irq_wake_thread().
1672 */
1673 if (new->flags & IRQF_ONESHOT) {
1674 /*
1675 * Unlikely to have 32 resp 64 irqs sharing one line,
1676 * but who knows.
1677 */
1678 if (thread_mask == ~0UL) {
1679 ret = -EBUSY;
1680 goto out_unlock;
1681 }
1682 /*
1683 * The thread_mask for the action is or'ed to
1684 * desc->thread_active to indicate that the
1685 * IRQF_ONESHOT thread handler has been woken, but not
1686 * yet finished. The bit is cleared when a thread
1687 * completes. When all threads of a shared interrupt
1688 * line have completed desc->threads_active becomes
1689 * zero and the interrupt line is unmasked. See
1690 * handle.c:irq_wake_thread() for further information.
1691 *
1692 * If no thread is woken by primary (hard irq context)
1693 * interrupt handlers, then desc->threads_active is
1694 * also checked for zero to unmask the irq line in the
1695 * affected hard irq flow handlers
1696 * (handle_[fasteoi|level]_irq).
1697 *
1698 * The new action gets the first zero bit of
1699 * thread_mask assigned. See the loop above which or's
1700 * all existing action->thread_mask bits.
1701 */
1702 new->thread_mask = 1UL << ffz(thread_mask);
1703
1704 } else if (new->handler == irq_default_primary_handler &&
1705 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1706 /*
1707 * The interrupt was requested with handler = NULL, so
1708 * we use the default primary handler for it. But it
1709 * does not have the oneshot flag set. In combination
1710 * with level interrupts this is deadly, because the
1711 * default primary handler just wakes the thread, then
1712 * the irq lines is reenabled, but the device still
1713 * has the level irq asserted. Rinse and repeat....
1714 *
1715 * While this works for edge type interrupts, we play
1716 * it safe and reject unconditionally because we can't
1717 * say for sure which type this interrupt really
1718 * has. The type flags are unreliable as the
1719 * underlying chip implementation can override them.
1720 */
1721 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1722 new->name, irq);
1723 ret = -EINVAL;
1724 goto out_unlock;
1725 }
1726
1727 if (!shared) {
1728 /* Setup the type (level, edge polarity) if configured: */
1729 if (new->flags & IRQF_TRIGGER_MASK) {
1730 ret = __irq_set_trigger(desc,
1731 new->flags & IRQF_TRIGGER_MASK);
1732
1733 if (ret)
1734 goto out_unlock;
1735 }
1736
1737 /*
1738 * Activate the interrupt. That activation must happen
1739 * independently of IRQ_NOAUTOEN. request_irq() can fail
1740 * and the callers are supposed to handle
1741 * that. enable_irq() of an interrupt requested with
1742 * IRQ_NOAUTOEN is not supposed to fail. The activation
1743 * keeps it in shutdown mode, it merily associates
1744 * resources if necessary and if that's not possible it
1745 * fails. Interrupts which are in managed shutdown mode
1746 * will simply ignore that activation request.
1747 */
1748 ret = irq_activate(desc);
1749 if (ret)
1750 goto out_unlock;
1751
1752 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1753 IRQS_ONESHOT | IRQS_WAITING);
1754 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1755
1756 if (new->flags & IRQF_PERCPU) {
1757 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1758 irq_settings_set_per_cpu(desc);
1759 if (new->flags & IRQF_NO_DEBUG)
1760 irq_settings_set_no_debug(desc);
1761 }
1762
1763 if (noirqdebug)
1764 irq_settings_set_no_debug(desc);
1765
1766 if (new->flags & IRQF_ONESHOT)
1767 desc->istate |= IRQS_ONESHOT;
1768
1769 /* Exclude IRQ from balancing if requested */
1770 if (new->flags & IRQF_NOBALANCING) {
1771 irq_settings_set_no_balancing(desc);
1772 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1773 }
1774
1775 if (!(new->flags & IRQF_NO_AUTOEN) &&
1776 irq_settings_can_autoenable(desc)) {
1777 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1778 } else {
1779 /*
1780 * Shared interrupts do not go well with disabling
1781 * auto enable. The sharing interrupt might request
1782 * it while it's still disabled and then wait for
1783 * interrupts forever.
1784 */
1785 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1786 /* Undo nested disables: */
1787 desc->depth = 1;
1788 }
1789
1790 } else if (new->flags & IRQF_TRIGGER_MASK) {
1791 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1792 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1793
1794 if (nmsk != omsk)
1795 /* hope the handler works with current trigger mode */
1796 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1797 irq, omsk, nmsk);
1798 }
1799
1800 *old_ptr = new;
1801
1802 irq_pm_install_action(desc, new);
1803
1804 /* Reset broken irq detection when installing new handler */
1805 desc->irq_count = 0;
1806 desc->irqs_unhandled = 0;
1807
1808 /*
1809 * Check whether we disabled the irq via the spurious handler
1810 * before. Reenable it and give it another chance.
1811 */
1812 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1813 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1814 __enable_irq(desc);
1815 }
1816
1817 raw_spin_unlock_irqrestore(&desc->lock, flags);
1818 chip_bus_sync_unlock(desc);
1819 mutex_unlock(&desc->request_mutex);
1820
1821 irq_setup_timings(desc, new);
1822
1823 wake_up_and_wait_for_irq_thread_ready(desc, new);
1824 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1825
1826 register_irq_proc(irq, desc);
1827 new->dir = NULL;
1828 register_handler_proc(irq, new);
1829 return 0;
1830
1831mismatch:
1832 if (!(new->flags & IRQF_PROBE_SHARED)) {
1833 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1834 irq, new->flags, new->name, old->flags, old->name);
1835#ifdef CONFIG_DEBUG_SHIRQ
1836 dump_stack();
1837#endif
1838 }
1839 ret = -EBUSY;
1840
1841out_unlock:
1842 raw_spin_unlock_irqrestore(&desc->lock, flags);
1843
1844 if (!desc->action)
1845 irq_release_resources(desc);
1846out_bus_unlock:
1847 chip_bus_sync_unlock(desc);
1848 mutex_unlock(&desc->request_mutex);
1849
1850out_thread:
1851 if (new->thread) {
1852 struct task_struct *t = new->thread;
1853
1854 new->thread = NULL;
1855 kthread_stop_put(t);
1856 }
1857 if (new->secondary && new->secondary->thread) {
1858 struct task_struct *t = new->secondary->thread;
1859
1860 new->secondary->thread = NULL;
1861 kthread_stop_put(t);
1862 }
1863out_mput:
1864 module_put(desc->owner);
1865 return ret;
1866}
1867
1868/*
1869 * Internal function to unregister an irqaction - used to free
1870 * regular and special interrupts that are part of the architecture.
1871 */
1872static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1873{
1874 unsigned irq = desc->irq_data.irq;
1875 struct irqaction *action, **action_ptr;
1876 unsigned long flags;
1877
1878 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1879
1880 mutex_lock(&desc->request_mutex);
1881 chip_bus_lock(desc);
1882 raw_spin_lock_irqsave(&desc->lock, flags);
1883
1884 /*
1885 * There can be multiple actions per IRQ descriptor, find the right
1886 * one based on the dev_id:
1887 */
1888 action_ptr = &desc->action;
1889 for (;;) {
1890 action = *action_ptr;
1891
1892 if (!action) {
1893 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1894 raw_spin_unlock_irqrestore(&desc->lock, flags);
1895 chip_bus_sync_unlock(desc);
1896 mutex_unlock(&desc->request_mutex);
1897 return NULL;
1898 }
1899
1900 if (action->dev_id == dev_id)
1901 break;
1902 action_ptr = &action->next;
1903 }
1904
1905 /* Found it - now remove it from the list of entries: */
1906 *action_ptr = action->next;
1907
1908 irq_pm_remove_action(desc, action);
1909
1910 /* If this was the last handler, shut down the IRQ line: */
1911 if (!desc->action) {
1912 irq_settings_clr_disable_unlazy(desc);
1913 /* Only shutdown. Deactivate after synchronize_hardirq() */
1914 irq_shutdown(desc);
1915 }
1916
1917#ifdef CONFIG_SMP
1918 /* make sure affinity_hint is cleaned up */
1919 if (WARN_ON_ONCE(desc->affinity_hint))
1920 desc->affinity_hint = NULL;
1921#endif
1922
1923 raw_spin_unlock_irqrestore(&desc->lock, flags);
1924 /*
1925 * Drop bus_lock here so the changes which were done in the chip
1926 * callbacks above are synced out to the irq chips which hang
1927 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1928 *
1929 * Aside of that the bus_lock can also be taken from the threaded
1930 * handler in irq_finalize_oneshot() which results in a deadlock
1931 * because kthread_stop() would wait forever for the thread to
1932 * complete, which is blocked on the bus lock.
1933 *
1934 * The still held desc->request_mutex() protects against a
1935 * concurrent request_irq() of this irq so the release of resources
1936 * and timing data is properly serialized.
1937 */
1938 chip_bus_sync_unlock(desc);
1939
1940 unregister_handler_proc(irq, action);
1941
1942 /*
1943 * Make sure it's not being used on another CPU and if the chip
1944 * supports it also make sure that there is no (not yet serviced)
1945 * interrupt in flight at the hardware level.
1946 */
1947 __synchronize_irq(desc);
1948
1949#ifdef CONFIG_DEBUG_SHIRQ
1950 /*
1951 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1952 * event to happen even now it's being freed, so let's make sure that
1953 * is so by doing an extra call to the handler ....
1954 *
1955 * ( We do this after actually deregistering it, to make sure that a
1956 * 'real' IRQ doesn't run in parallel with our fake. )
1957 */
1958 if (action->flags & IRQF_SHARED) {
1959 local_irq_save(flags);
1960 action->handler(irq, dev_id);
1961 local_irq_restore(flags);
1962 }
1963#endif
1964
1965 /*
1966 * The action has already been removed above, but the thread writes
1967 * its oneshot mask bit when it completes. Though request_mutex is
1968 * held across this which prevents __setup_irq() from handing out
1969 * the same bit to a newly requested action.
1970 */
1971 if (action->thread) {
1972 kthread_stop_put(action->thread);
1973 if (action->secondary && action->secondary->thread)
1974 kthread_stop_put(action->secondary->thread);
1975 }
1976
1977 /* Last action releases resources */
1978 if (!desc->action) {
1979 /*
1980 * Reacquire bus lock as irq_release_resources() might
1981 * require it to deallocate resources over the slow bus.
1982 */
1983 chip_bus_lock(desc);
1984 /*
1985 * There is no interrupt on the fly anymore. Deactivate it
1986 * completely.
1987 */
1988 raw_spin_lock_irqsave(&desc->lock, flags);
1989 irq_domain_deactivate_irq(&desc->irq_data);
1990 raw_spin_unlock_irqrestore(&desc->lock, flags);
1991
1992 irq_release_resources(desc);
1993 chip_bus_sync_unlock(desc);
1994 irq_remove_timings(desc);
1995 }
1996
1997 mutex_unlock(&desc->request_mutex);
1998
1999 irq_chip_pm_put(&desc->irq_data);
2000 module_put(desc->owner);
2001 kfree(action->secondary);
2002 return action;
2003}
2004
2005/**
2006 * free_irq - free an interrupt allocated with request_irq
2007 * @irq: Interrupt line to free
2008 * @dev_id: Device identity to free
2009 *
2010 * Remove an interrupt handler. The handler is removed and if the
2011 * interrupt line is no longer in use by any driver it is disabled.
2012 * On a shared IRQ the caller must ensure the interrupt is disabled
2013 * on the card it drives before calling this function. The function
2014 * does not return until any executing interrupts for this IRQ
2015 * have completed.
2016 *
2017 * This function must not be called from interrupt context.
2018 *
2019 * Returns the devname argument passed to request_irq.
2020 */
2021const void *free_irq(unsigned int irq, void *dev_id)
2022{
2023 struct irq_desc *desc = irq_to_desc(irq);
2024 struct irqaction *action;
2025 const char *devname;
2026
2027 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2028 return NULL;
2029
2030#ifdef CONFIG_SMP
2031 if (WARN_ON(desc->affinity_notify))
2032 desc->affinity_notify = NULL;
2033#endif
2034
2035 action = __free_irq(desc, dev_id);
2036
2037 if (!action)
2038 return NULL;
2039
2040 devname = action->name;
2041 kfree(action);
2042 return devname;
2043}
2044EXPORT_SYMBOL(free_irq);
2045
2046/* This function must be called with desc->lock held */
2047static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2048{
2049 const char *devname = NULL;
2050
2051 desc->istate &= ~IRQS_NMI;
2052
2053 if (!WARN_ON(desc->action == NULL)) {
2054 irq_pm_remove_action(desc, desc->action);
2055 devname = desc->action->name;
2056 unregister_handler_proc(irq, desc->action);
2057
2058 kfree(desc->action);
2059 desc->action = NULL;
2060 }
2061
2062 irq_settings_clr_disable_unlazy(desc);
2063 irq_shutdown_and_deactivate(desc);
2064
2065 irq_release_resources(desc);
2066
2067 irq_chip_pm_put(&desc->irq_data);
2068 module_put(desc->owner);
2069
2070 return devname;
2071}
2072
2073const void *free_nmi(unsigned int irq, void *dev_id)
2074{
2075 struct irq_desc *desc = irq_to_desc(irq);
2076 unsigned long flags;
2077 const void *devname;
2078
2079 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2080 return NULL;
2081
2082 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2083 return NULL;
2084
2085 /* NMI still enabled */
2086 if (WARN_ON(desc->depth == 0))
2087 disable_nmi_nosync(irq);
2088
2089 raw_spin_lock_irqsave(&desc->lock, flags);
2090
2091 irq_nmi_teardown(desc);
2092 devname = __cleanup_nmi(irq, desc);
2093
2094 raw_spin_unlock_irqrestore(&desc->lock, flags);
2095
2096 return devname;
2097}
2098
2099/**
2100 * request_threaded_irq - allocate an interrupt line
2101 * @irq: Interrupt line to allocate
2102 * @handler: Function to be called when the IRQ occurs.
2103 * Primary handler for threaded interrupts.
2104 * If handler is NULL and thread_fn != NULL
2105 * the default primary handler is installed.
2106 * @thread_fn: Function called from the irq handler thread
2107 * If NULL, no irq thread is created
2108 * @irqflags: Interrupt type flags
2109 * @devname: An ascii name for the claiming device
2110 * @dev_id: A cookie passed back to the handler function
2111 *
2112 * This call allocates interrupt resources and enables the
2113 * interrupt line and IRQ handling. From the point this
2114 * call is made your handler function may be invoked. Since
2115 * your handler function must clear any interrupt the board
2116 * raises, you must take care both to initialise your hardware
2117 * and to set up the interrupt handler in the right order.
2118 *
2119 * If you want to set up a threaded irq handler for your device
2120 * then you need to supply @handler and @thread_fn. @handler is
2121 * still called in hard interrupt context and has to check
2122 * whether the interrupt originates from the device. If yes it
2123 * needs to disable the interrupt on the device and return
2124 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2125 * @thread_fn. This split handler design is necessary to support
2126 * shared interrupts.
2127 *
2128 * Dev_id must be globally unique. Normally the address of the
2129 * device data structure is used as the cookie. Since the handler
2130 * receives this value it makes sense to use it.
2131 *
2132 * If your interrupt is shared you must pass a non NULL dev_id
2133 * as this is required when freeing the interrupt.
2134 *
2135 * Flags:
2136 *
2137 * IRQF_SHARED Interrupt is shared
2138 * IRQF_TRIGGER_* Specify active edge(s) or level
2139 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2140 */
2141int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2142 irq_handler_t thread_fn, unsigned long irqflags,
2143 const char *devname, void *dev_id)
2144{
2145 struct irqaction *action;
2146 struct irq_desc *desc;
2147 int retval;
2148
2149 if (irq == IRQ_NOTCONNECTED)
2150 return -ENOTCONN;
2151
2152 /*
2153 * Sanity-check: shared interrupts must pass in a real dev-ID,
2154 * otherwise we'll have trouble later trying to figure out
2155 * which interrupt is which (messes up the interrupt freeing
2156 * logic etc).
2157 *
2158 * Also shared interrupts do not go well with disabling auto enable.
2159 * The sharing interrupt might request it while it's still disabled
2160 * and then wait for interrupts forever.
2161 *
2162 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2163 * it cannot be set along with IRQF_NO_SUSPEND.
2164 */
2165 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2166 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2167 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2168 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2169 return -EINVAL;
2170
2171 desc = irq_to_desc(irq);
2172 if (!desc)
2173 return -EINVAL;
2174
2175 if (!irq_settings_can_request(desc) ||
2176 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2177 return -EINVAL;
2178
2179 if (!handler) {
2180 if (!thread_fn)
2181 return -EINVAL;
2182 handler = irq_default_primary_handler;
2183 }
2184
2185 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2186 if (!action)
2187 return -ENOMEM;
2188
2189 action->handler = handler;
2190 action->thread_fn = thread_fn;
2191 action->flags = irqflags;
2192 action->name = devname;
2193 action->dev_id = dev_id;
2194
2195 retval = irq_chip_pm_get(&desc->irq_data);
2196 if (retval < 0) {
2197 kfree(action);
2198 return retval;
2199 }
2200
2201 retval = __setup_irq(irq, desc, action);
2202
2203 if (retval) {
2204 irq_chip_pm_put(&desc->irq_data);
2205 kfree(action->secondary);
2206 kfree(action);
2207 }
2208
2209#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2210 if (!retval && (irqflags & IRQF_SHARED)) {
2211 /*
2212 * It's a shared IRQ -- the driver ought to be prepared for it
2213 * to happen immediately, so let's make sure....
2214 * We disable the irq to make sure that a 'real' IRQ doesn't
2215 * run in parallel with our fake.
2216 */
2217 unsigned long flags;
2218
2219 disable_irq(irq);
2220 local_irq_save(flags);
2221
2222 handler(irq, dev_id);
2223
2224 local_irq_restore(flags);
2225 enable_irq(irq);
2226 }
2227#endif
2228 return retval;
2229}
2230EXPORT_SYMBOL(request_threaded_irq);
2231
2232/**
2233 * request_any_context_irq - allocate an interrupt line
2234 * @irq: Interrupt line to allocate
2235 * @handler: Function to be called when the IRQ occurs.
2236 * Threaded handler for threaded interrupts.
2237 * @flags: Interrupt type flags
2238 * @name: An ascii name for the claiming device
2239 * @dev_id: A cookie passed back to the handler function
2240 *
2241 * This call allocates interrupt resources and enables the
2242 * interrupt line and IRQ handling. It selects either a
2243 * hardirq or threaded handling method depending on the
2244 * context.
2245 *
2246 * On failure, it returns a negative value. On success,
2247 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2248 */
2249int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2250 unsigned long flags, const char *name, void *dev_id)
2251{
2252 struct irq_desc *desc;
2253 int ret;
2254
2255 if (irq == IRQ_NOTCONNECTED)
2256 return -ENOTCONN;
2257
2258 desc = irq_to_desc(irq);
2259 if (!desc)
2260 return -EINVAL;
2261
2262 if (irq_settings_is_nested_thread(desc)) {
2263 ret = request_threaded_irq(irq, NULL, handler,
2264 flags, name, dev_id);
2265 return !ret ? IRQC_IS_NESTED : ret;
2266 }
2267
2268 ret = request_irq(irq, handler, flags, name, dev_id);
2269 return !ret ? IRQC_IS_HARDIRQ : ret;
2270}
2271EXPORT_SYMBOL_GPL(request_any_context_irq);
2272
2273/**
2274 * request_nmi - allocate an interrupt line for NMI delivery
2275 * @irq: Interrupt line to allocate
2276 * @handler: Function to be called when the IRQ occurs.
2277 * Threaded handler for threaded interrupts.
2278 * @irqflags: Interrupt type flags
2279 * @name: An ascii name for the claiming device
2280 * @dev_id: A cookie passed back to the handler function
2281 *
2282 * This call allocates interrupt resources and enables the
2283 * interrupt line and IRQ handling. It sets up the IRQ line
2284 * to be handled as an NMI.
2285 *
2286 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2287 * cannot be threaded.
2288 *
2289 * Interrupt lines requested for NMI delivering must produce per cpu
2290 * interrupts and have auto enabling setting disabled.
2291 *
2292 * Dev_id must be globally unique. Normally the address of the
2293 * device data structure is used as the cookie. Since the handler
2294 * receives this value it makes sense to use it.
2295 *
2296 * If the interrupt line cannot be used to deliver NMIs, function
2297 * will fail and return a negative value.
2298 */
2299int request_nmi(unsigned int irq, irq_handler_t handler,
2300 unsigned long irqflags, const char *name, void *dev_id)
2301{
2302 struct irqaction *action;
2303 struct irq_desc *desc;
2304 unsigned long flags;
2305 int retval;
2306
2307 if (irq == IRQ_NOTCONNECTED)
2308 return -ENOTCONN;
2309
2310 /* NMI cannot be shared, used for Polling */
2311 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2312 return -EINVAL;
2313
2314 if (!(irqflags & IRQF_PERCPU))
2315 return -EINVAL;
2316
2317 if (!handler)
2318 return -EINVAL;
2319
2320 desc = irq_to_desc(irq);
2321
2322 if (!desc || (irq_settings_can_autoenable(desc) &&
2323 !(irqflags & IRQF_NO_AUTOEN)) ||
2324 !irq_settings_can_request(desc) ||
2325 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2326 !irq_supports_nmi(desc))
2327 return -EINVAL;
2328
2329 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2330 if (!action)
2331 return -ENOMEM;
2332
2333 action->handler = handler;
2334 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2335 action->name = name;
2336 action->dev_id = dev_id;
2337
2338 retval = irq_chip_pm_get(&desc->irq_data);
2339 if (retval < 0)
2340 goto err_out;
2341
2342 retval = __setup_irq(irq, desc, action);
2343 if (retval)
2344 goto err_irq_setup;
2345
2346 raw_spin_lock_irqsave(&desc->lock, flags);
2347
2348 /* Setup NMI state */
2349 desc->istate |= IRQS_NMI;
2350 retval = irq_nmi_setup(desc);
2351 if (retval) {
2352 __cleanup_nmi(irq, desc);
2353 raw_spin_unlock_irqrestore(&desc->lock, flags);
2354 return -EINVAL;
2355 }
2356
2357 raw_spin_unlock_irqrestore(&desc->lock, flags);
2358
2359 return 0;
2360
2361err_irq_setup:
2362 irq_chip_pm_put(&desc->irq_data);
2363err_out:
2364 kfree(action);
2365
2366 return retval;
2367}
2368
2369void enable_percpu_irq(unsigned int irq, unsigned int type)
2370{
2371 unsigned int cpu = smp_processor_id();
2372 unsigned long flags;
2373 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2374
2375 if (!desc)
2376 return;
2377
2378 /*
2379 * If the trigger type is not specified by the caller, then
2380 * use the default for this interrupt.
2381 */
2382 type &= IRQ_TYPE_SENSE_MASK;
2383 if (type == IRQ_TYPE_NONE)
2384 type = irqd_get_trigger_type(&desc->irq_data);
2385
2386 if (type != IRQ_TYPE_NONE) {
2387 int ret;
2388
2389 ret = __irq_set_trigger(desc, type);
2390
2391 if (ret) {
2392 WARN(1, "failed to set type for IRQ%d\n", irq);
2393 goto out;
2394 }
2395 }
2396
2397 irq_percpu_enable(desc, cpu);
2398out:
2399 irq_put_desc_unlock(desc, flags);
2400}
2401EXPORT_SYMBOL_GPL(enable_percpu_irq);
2402
2403void enable_percpu_nmi(unsigned int irq, unsigned int type)
2404{
2405 enable_percpu_irq(irq, type);
2406}
2407
2408/**
2409 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2410 * @irq: Linux irq number to check for
2411 *
2412 * Must be called from a non migratable context. Returns the enable
2413 * state of a per cpu interrupt on the current cpu.
2414 */
2415bool irq_percpu_is_enabled(unsigned int irq)
2416{
2417 unsigned int cpu = smp_processor_id();
2418 struct irq_desc *desc;
2419 unsigned long flags;
2420 bool is_enabled;
2421
2422 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2423 if (!desc)
2424 return false;
2425
2426 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2427 irq_put_desc_unlock(desc, flags);
2428
2429 return is_enabled;
2430}
2431EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2432
2433void disable_percpu_irq(unsigned int irq)
2434{
2435 unsigned int cpu = smp_processor_id();
2436 unsigned long flags;
2437 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2438
2439 if (!desc)
2440 return;
2441
2442 irq_percpu_disable(desc, cpu);
2443 irq_put_desc_unlock(desc, flags);
2444}
2445EXPORT_SYMBOL_GPL(disable_percpu_irq);
2446
2447void disable_percpu_nmi(unsigned int irq)
2448{
2449 disable_percpu_irq(irq);
2450}
2451
2452/*
2453 * Internal function to unregister a percpu irqaction.
2454 */
2455static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2456{
2457 struct irq_desc *desc = irq_to_desc(irq);
2458 struct irqaction *action;
2459 unsigned long flags;
2460
2461 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2462
2463 if (!desc)
2464 return NULL;
2465
2466 raw_spin_lock_irqsave(&desc->lock, flags);
2467
2468 action = desc->action;
2469 if (!action || action->percpu_dev_id != dev_id) {
2470 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2471 goto bad;
2472 }
2473
2474 if (!cpumask_empty(desc->percpu_enabled)) {
2475 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2476 irq, cpumask_first(desc->percpu_enabled));
2477 goto bad;
2478 }
2479
2480 /* Found it - now remove it from the list of entries: */
2481 desc->action = NULL;
2482
2483 desc->istate &= ~IRQS_NMI;
2484
2485 raw_spin_unlock_irqrestore(&desc->lock, flags);
2486
2487 unregister_handler_proc(irq, action);
2488
2489 irq_chip_pm_put(&desc->irq_data);
2490 module_put(desc->owner);
2491 return action;
2492
2493bad:
2494 raw_spin_unlock_irqrestore(&desc->lock, flags);
2495 return NULL;
2496}
2497
2498/**
2499 * remove_percpu_irq - free a per-cpu interrupt
2500 * @irq: Interrupt line to free
2501 * @act: irqaction for the interrupt
2502 *
2503 * Used to remove interrupts statically setup by the early boot process.
2504 */
2505void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2506{
2507 struct irq_desc *desc = irq_to_desc(irq);
2508
2509 if (desc && irq_settings_is_per_cpu_devid(desc))
2510 __free_percpu_irq(irq, act->percpu_dev_id);
2511}
2512
2513/**
2514 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2515 * @irq: Interrupt line to free
2516 * @dev_id: Device identity to free
2517 *
2518 * Remove a percpu interrupt handler. The handler is removed, but
2519 * the interrupt line is not disabled. This must be done on each
2520 * CPU before calling this function. The function does not return
2521 * until any executing interrupts for this IRQ have completed.
2522 *
2523 * This function must not be called from interrupt context.
2524 */
2525void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2526{
2527 struct irq_desc *desc = irq_to_desc(irq);
2528
2529 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2530 return;
2531
2532 chip_bus_lock(desc);
2533 kfree(__free_percpu_irq(irq, dev_id));
2534 chip_bus_sync_unlock(desc);
2535}
2536EXPORT_SYMBOL_GPL(free_percpu_irq);
2537
2538void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2539{
2540 struct irq_desc *desc = irq_to_desc(irq);
2541
2542 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2543 return;
2544
2545 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2546 return;
2547
2548 kfree(__free_percpu_irq(irq, dev_id));
2549}
2550
2551/**
2552 * setup_percpu_irq - setup a per-cpu interrupt
2553 * @irq: Interrupt line to setup
2554 * @act: irqaction for the interrupt
2555 *
2556 * Used to statically setup per-cpu interrupts in the early boot process.
2557 */
2558int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2559{
2560 struct irq_desc *desc = irq_to_desc(irq);
2561 int retval;
2562
2563 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2564 return -EINVAL;
2565
2566 retval = irq_chip_pm_get(&desc->irq_data);
2567 if (retval < 0)
2568 return retval;
2569
2570 retval = __setup_irq(irq, desc, act);
2571
2572 if (retval)
2573 irq_chip_pm_put(&desc->irq_data);
2574
2575 return retval;
2576}
2577
2578/**
2579 * __request_percpu_irq - allocate a percpu interrupt line
2580 * @irq: Interrupt line to allocate
2581 * @handler: Function to be called when the IRQ occurs.
2582 * @flags: Interrupt type flags (IRQF_TIMER only)
2583 * @devname: An ascii name for the claiming device
2584 * @dev_id: A percpu cookie passed back to the handler function
2585 *
2586 * This call allocates interrupt resources and enables the
2587 * interrupt on the local CPU. If the interrupt is supposed to be
2588 * enabled on other CPUs, it has to be done on each CPU using
2589 * enable_percpu_irq().
2590 *
2591 * Dev_id must be globally unique. It is a per-cpu variable, and
2592 * the handler gets called with the interrupted CPU's instance of
2593 * that variable.
2594 */
2595int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2596 unsigned long flags, const char *devname,
2597 void __percpu *dev_id)
2598{
2599 struct irqaction *action;
2600 struct irq_desc *desc;
2601 int retval;
2602
2603 if (!dev_id)
2604 return -EINVAL;
2605
2606 desc = irq_to_desc(irq);
2607 if (!desc || !irq_settings_can_request(desc) ||
2608 !irq_settings_is_per_cpu_devid(desc))
2609 return -EINVAL;
2610
2611 if (flags && flags != IRQF_TIMER)
2612 return -EINVAL;
2613
2614 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2615 if (!action)
2616 return -ENOMEM;
2617
2618 action->handler = handler;
2619 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2620 action->name = devname;
2621 action->percpu_dev_id = dev_id;
2622
2623 retval = irq_chip_pm_get(&desc->irq_data);
2624 if (retval < 0) {
2625 kfree(action);
2626 return retval;
2627 }
2628
2629 retval = __setup_irq(irq, desc, action);
2630
2631 if (retval) {
2632 irq_chip_pm_put(&desc->irq_data);
2633 kfree(action);
2634 }
2635
2636 return retval;
2637}
2638EXPORT_SYMBOL_GPL(__request_percpu_irq);
2639
2640/**
2641 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2642 * @irq: Interrupt line to allocate
2643 * @handler: Function to be called when the IRQ occurs.
2644 * @name: An ascii name for the claiming device
2645 * @dev_id: A percpu cookie passed back to the handler function
2646 *
2647 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2648 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2649 * being enabled on the same CPU by using enable_percpu_nmi().
2650 *
2651 * Dev_id must be globally unique. It is a per-cpu variable, and
2652 * the handler gets called with the interrupted CPU's instance of
2653 * that variable.
2654 *
2655 * Interrupt lines requested for NMI delivering should have auto enabling
2656 * setting disabled.
2657 *
2658 * If the interrupt line cannot be used to deliver NMIs, function
2659 * will fail returning a negative value.
2660 */
2661int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2662 const char *name, void __percpu *dev_id)
2663{
2664 struct irqaction *action;
2665 struct irq_desc *desc;
2666 unsigned long flags;
2667 int retval;
2668
2669 if (!handler)
2670 return -EINVAL;
2671
2672 desc = irq_to_desc(irq);
2673
2674 if (!desc || !irq_settings_can_request(desc) ||
2675 !irq_settings_is_per_cpu_devid(desc) ||
2676 irq_settings_can_autoenable(desc) ||
2677 !irq_supports_nmi(desc))
2678 return -EINVAL;
2679
2680 /* The line cannot already be NMI */
2681 if (desc->istate & IRQS_NMI)
2682 return -EINVAL;
2683
2684 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2685 if (!action)
2686 return -ENOMEM;
2687
2688 action->handler = handler;
2689 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2690 | IRQF_NOBALANCING;
2691 action->name = name;
2692 action->percpu_dev_id = dev_id;
2693
2694 retval = irq_chip_pm_get(&desc->irq_data);
2695 if (retval < 0)
2696 goto err_out;
2697
2698 retval = __setup_irq(irq, desc, action);
2699 if (retval)
2700 goto err_irq_setup;
2701
2702 raw_spin_lock_irqsave(&desc->lock, flags);
2703 desc->istate |= IRQS_NMI;
2704 raw_spin_unlock_irqrestore(&desc->lock, flags);
2705
2706 return 0;
2707
2708err_irq_setup:
2709 irq_chip_pm_put(&desc->irq_data);
2710err_out:
2711 kfree(action);
2712
2713 return retval;
2714}
2715
2716/**
2717 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2718 * @irq: Interrupt line to prepare for NMI delivery
2719 *
2720 * This call prepares an interrupt line to deliver NMI on the current CPU,
2721 * before that interrupt line gets enabled with enable_percpu_nmi().
2722 *
2723 * As a CPU local operation, this should be called from non-preemptible
2724 * context.
2725 *
2726 * If the interrupt line cannot be used to deliver NMIs, function
2727 * will fail returning a negative value.
2728 */
2729int prepare_percpu_nmi(unsigned int irq)
2730{
2731 unsigned long flags;
2732 struct irq_desc *desc;
2733 int ret = 0;
2734
2735 WARN_ON(preemptible());
2736
2737 desc = irq_get_desc_lock(irq, &flags,
2738 IRQ_GET_DESC_CHECK_PERCPU);
2739 if (!desc)
2740 return -EINVAL;
2741
2742 if (WARN(!(desc->istate & IRQS_NMI),
2743 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2744 irq)) {
2745 ret = -EINVAL;
2746 goto out;
2747 }
2748
2749 ret = irq_nmi_setup(desc);
2750 if (ret) {
2751 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2752 goto out;
2753 }
2754
2755out:
2756 irq_put_desc_unlock(desc, flags);
2757 return ret;
2758}
2759
2760/**
2761 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2762 * @irq: Interrupt line from which CPU local NMI configuration should be
2763 * removed
2764 *
2765 * This call undoes the setup done by prepare_percpu_nmi().
2766 *
2767 * IRQ line should not be enabled for the current CPU.
2768 *
2769 * As a CPU local operation, this should be called from non-preemptible
2770 * context.
2771 */
2772void teardown_percpu_nmi(unsigned int irq)
2773{
2774 unsigned long flags;
2775 struct irq_desc *desc;
2776
2777 WARN_ON(preemptible());
2778
2779 desc = irq_get_desc_lock(irq, &flags,
2780 IRQ_GET_DESC_CHECK_PERCPU);
2781 if (!desc)
2782 return;
2783
2784 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2785 goto out;
2786
2787 irq_nmi_teardown(desc);
2788out:
2789 irq_put_desc_unlock(desc, flags);
2790}
2791
2792int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2793 bool *state)
2794{
2795 struct irq_chip *chip;
2796 int err = -EINVAL;
2797
2798 do {
2799 chip = irq_data_get_irq_chip(data);
2800 if (WARN_ON_ONCE(!chip))
2801 return -ENODEV;
2802 if (chip->irq_get_irqchip_state)
2803 break;
2804#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2805 data = data->parent_data;
2806#else
2807 data = NULL;
2808#endif
2809 } while (data);
2810
2811 if (data)
2812 err = chip->irq_get_irqchip_state(data, which, state);
2813 return err;
2814}
2815
2816/**
2817 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2818 * @irq: Interrupt line that is forwarded to a VM
2819 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2820 * @state: a pointer to a boolean where the state is to be stored
2821 *
2822 * This call snapshots the internal irqchip state of an
2823 * interrupt, returning into @state the bit corresponding to
2824 * stage @which
2825 *
2826 * This function should be called with preemption disabled if the
2827 * interrupt controller has per-cpu registers.
2828 */
2829int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2830 bool *state)
2831{
2832 struct irq_desc *desc;
2833 struct irq_data *data;
2834 unsigned long flags;
2835 int err = -EINVAL;
2836
2837 desc = irq_get_desc_buslock(irq, &flags, 0);
2838 if (!desc)
2839 return err;
2840
2841 data = irq_desc_get_irq_data(desc);
2842
2843 err = __irq_get_irqchip_state(data, which, state);
2844
2845 irq_put_desc_busunlock(desc, flags);
2846 return err;
2847}
2848EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2849
2850/**
2851 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2852 * @irq: Interrupt line that is forwarded to a VM
2853 * @which: State to be restored (one of IRQCHIP_STATE_*)
2854 * @val: Value corresponding to @which
2855 *
2856 * This call sets the internal irqchip state of an interrupt,
2857 * depending on the value of @which.
2858 *
2859 * This function should be called with migration disabled if the
2860 * interrupt controller has per-cpu registers.
2861 */
2862int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2863 bool val)
2864{
2865 struct irq_desc *desc;
2866 struct irq_data *data;
2867 struct irq_chip *chip;
2868 unsigned long flags;
2869 int err = -EINVAL;
2870
2871 desc = irq_get_desc_buslock(irq, &flags, 0);
2872 if (!desc)
2873 return err;
2874
2875 data = irq_desc_get_irq_data(desc);
2876
2877 do {
2878 chip = irq_data_get_irq_chip(data);
2879 if (WARN_ON_ONCE(!chip)) {
2880 err = -ENODEV;
2881 goto out_unlock;
2882 }
2883 if (chip->irq_set_irqchip_state)
2884 break;
2885#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2886 data = data->parent_data;
2887#else
2888 data = NULL;
2889#endif
2890 } while (data);
2891
2892 if (data)
2893 err = chip->irq_set_irqchip_state(data, which, val);
2894
2895out_unlock:
2896 irq_put_desc_busunlock(desc, flags);
2897 return err;
2898}
2899EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2900
2901/**
2902 * irq_has_action - Check whether an interrupt is requested
2903 * @irq: The linux irq number
2904 *
2905 * Returns: A snapshot of the current state
2906 */
2907bool irq_has_action(unsigned int irq)
2908{
2909 bool res;
2910
2911 rcu_read_lock();
2912 res = irq_desc_has_action(irq_to_desc(irq));
2913 rcu_read_unlock();
2914 return res;
2915}
2916EXPORT_SYMBOL_GPL(irq_has_action);
2917
2918/**
2919 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2920 * @irq: The linux irq number
2921 * @bitmask: The bitmask to evaluate
2922 *
2923 * Returns: True if one of the bits in @bitmask is set
2924 */
2925bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2926{
2927 struct irq_desc *desc;
2928 bool res = false;
2929
2930 rcu_read_lock();
2931 desc = irq_to_desc(irq);
2932 if (desc)
2933 res = !!(desc->status_use_accessors & bitmask);
2934 rcu_read_unlock();
2935 return res;
2936}
2937EXPORT_SYMBOL_GPL(irq_check_status_bit);
1/*
2 * linux/kernel/irq/manage.c
3 *
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
6 *
7 * This file contains driver APIs to the irq subsystem.
8 */
9
10#define pr_fmt(fmt) "genirq: " fmt
11
12#include <linux/irq.h>
13#include <linux/kthread.h>
14#include <linux/module.h>
15#include <linux/random.h>
16#include <linux/interrupt.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/task_work.h>
20
21#include "internals.h"
22
23#ifdef CONFIG_IRQ_FORCED_THREADING
24__read_mostly bool force_irqthreads;
25
26static int __init setup_forced_irqthreads(char *arg)
27{
28 force_irqthreads = true;
29 return 0;
30}
31early_param("threadirqs", setup_forced_irqthreads);
32#endif
33
34/**
35 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
36 * @irq: interrupt number to wait for
37 *
38 * This function waits for any pending IRQ handlers for this interrupt
39 * to complete before returning. If you use this function while
40 * holding a resource the IRQ handler may need you will deadlock.
41 *
42 * This function may be called - with care - from IRQ context.
43 */
44void synchronize_irq(unsigned int irq)
45{
46 struct irq_desc *desc = irq_to_desc(irq);
47 bool inprogress;
48
49 if (!desc)
50 return;
51
52 do {
53 unsigned long flags;
54
55 /*
56 * Wait until we're out of the critical section. This might
57 * give the wrong answer due to the lack of memory barriers.
58 */
59 while (irqd_irq_inprogress(&desc->irq_data))
60 cpu_relax();
61
62 /* Ok, that indicated we're done: double-check carefully. */
63 raw_spin_lock_irqsave(&desc->lock, flags);
64 inprogress = irqd_irq_inprogress(&desc->irq_data);
65 raw_spin_unlock_irqrestore(&desc->lock, flags);
66
67 /* Oops, that failed? */
68 } while (inprogress);
69
70 /*
71 * We made sure that no hardirq handler is running. Now verify
72 * that no threaded handlers are active.
73 */
74 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
75}
76EXPORT_SYMBOL(synchronize_irq);
77
78#ifdef CONFIG_SMP
79cpumask_var_t irq_default_affinity;
80
81/**
82 * irq_can_set_affinity - Check if the affinity of a given irq can be set
83 * @irq: Interrupt to check
84 *
85 */
86int irq_can_set_affinity(unsigned int irq)
87{
88 struct irq_desc *desc = irq_to_desc(irq);
89
90 if (!desc || !irqd_can_balance(&desc->irq_data) ||
91 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
92 return 0;
93
94 return 1;
95}
96
97/**
98 * irq_set_thread_affinity - Notify irq threads to adjust affinity
99 * @desc: irq descriptor which has affitnity changed
100 *
101 * We just set IRQTF_AFFINITY and delegate the affinity setting
102 * to the interrupt thread itself. We can not call
103 * set_cpus_allowed_ptr() here as we hold desc->lock and this
104 * code can be called from hard interrupt context.
105 */
106void irq_set_thread_affinity(struct irq_desc *desc)
107{
108 struct irqaction *action = desc->action;
109
110 while (action) {
111 if (action->thread)
112 set_bit(IRQTF_AFFINITY, &action->thread_flags);
113 action = action->next;
114 }
115}
116
117#ifdef CONFIG_GENERIC_PENDING_IRQ
118static inline bool irq_can_move_pcntxt(struct irq_data *data)
119{
120 return irqd_can_move_in_process_context(data);
121}
122static inline bool irq_move_pending(struct irq_data *data)
123{
124 return irqd_is_setaffinity_pending(data);
125}
126static inline void
127irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
128{
129 cpumask_copy(desc->pending_mask, mask);
130}
131static inline void
132irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
133{
134 cpumask_copy(mask, desc->pending_mask);
135}
136#else
137static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
138static inline bool irq_move_pending(struct irq_data *data) { return false; }
139static inline void
140irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
141static inline void
142irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
143#endif
144
145int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
146 bool force)
147{
148 struct irq_desc *desc = irq_data_to_desc(data);
149 struct irq_chip *chip = irq_data_get_irq_chip(data);
150 int ret;
151
152 ret = chip->irq_set_affinity(data, mask, false);
153 switch (ret) {
154 case IRQ_SET_MASK_OK:
155 cpumask_copy(data->affinity, mask);
156 case IRQ_SET_MASK_OK_NOCOPY:
157 irq_set_thread_affinity(desc);
158 ret = 0;
159 }
160
161 return ret;
162}
163
164int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
165{
166 struct irq_chip *chip = irq_data_get_irq_chip(data);
167 struct irq_desc *desc = irq_data_to_desc(data);
168 int ret = 0;
169
170 if (!chip || !chip->irq_set_affinity)
171 return -EINVAL;
172
173 if (irq_can_move_pcntxt(data)) {
174 ret = irq_do_set_affinity(data, mask, false);
175 } else {
176 irqd_set_move_pending(data);
177 irq_copy_pending(desc, mask);
178 }
179
180 if (desc->affinity_notify) {
181 kref_get(&desc->affinity_notify->kref);
182 schedule_work(&desc->affinity_notify->work);
183 }
184 irqd_set(data, IRQD_AFFINITY_SET);
185
186 return ret;
187}
188
189/**
190 * irq_set_affinity - Set the irq affinity of a given irq
191 * @irq: Interrupt to set affinity
192 * @mask: cpumask
193 *
194 */
195int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
196{
197 struct irq_desc *desc = irq_to_desc(irq);
198 unsigned long flags;
199 int ret;
200
201 if (!desc)
202 return -EINVAL;
203
204 raw_spin_lock_irqsave(&desc->lock, flags);
205 ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
206 raw_spin_unlock_irqrestore(&desc->lock, flags);
207 return ret;
208}
209
210int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
211{
212 unsigned long flags;
213 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
214
215 if (!desc)
216 return -EINVAL;
217 desc->affinity_hint = m;
218 irq_put_desc_unlock(desc, flags);
219 return 0;
220}
221EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
222
223static void irq_affinity_notify(struct work_struct *work)
224{
225 struct irq_affinity_notify *notify =
226 container_of(work, struct irq_affinity_notify, work);
227 struct irq_desc *desc = irq_to_desc(notify->irq);
228 cpumask_var_t cpumask;
229 unsigned long flags;
230
231 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
232 goto out;
233
234 raw_spin_lock_irqsave(&desc->lock, flags);
235 if (irq_move_pending(&desc->irq_data))
236 irq_get_pending(cpumask, desc);
237 else
238 cpumask_copy(cpumask, desc->irq_data.affinity);
239 raw_spin_unlock_irqrestore(&desc->lock, flags);
240
241 notify->notify(notify, cpumask);
242
243 free_cpumask_var(cpumask);
244out:
245 kref_put(¬ify->kref, notify->release);
246}
247
248/**
249 * irq_set_affinity_notifier - control notification of IRQ affinity changes
250 * @irq: Interrupt for which to enable/disable notification
251 * @notify: Context for notification, or %NULL to disable
252 * notification. Function pointers must be initialised;
253 * the other fields will be initialised by this function.
254 *
255 * Must be called in process context. Notification may only be enabled
256 * after the IRQ is allocated and must be disabled before the IRQ is
257 * freed using free_irq().
258 */
259int
260irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
261{
262 struct irq_desc *desc = irq_to_desc(irq);
263 struct irq_affinity_notify *old_notify;
264 unsigned long flags;
265
266 /* The release function is promised process context */
267 might_sleep();
268
269 if (!desc)
270 return -EINVAL;
271
272 /* Complete initialisation of *notify */
273 if (notify) {
274 notify->irq = irq;
275 kref_init(¬ify->kref);
276 INIT_WORK(¬ify->work, irq_affinity_notify);
277 }
278
279 raw_spin_lock_irqsave(&desc->lock, flags);
280 old_notify = desc->affinity_notify;
281 desc->affinity_notify = notify;
282 raw_spin_unlock_irqrestore(&desc->lock, flags);
283
284 if (old_notify)
285 kref_put(&old_notify->kref, old_notify->release);
286
287 return 0;
288}
289EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
290
291#ifndef CONFIG_AUTO_IRQ_AFFINITY
292/*
293 * Generic version of the affinity autoselector.
294 */
295static int
296setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
297{
298 struct cpumask *set = irq_default_affinity;
299 int node = desc->irq_data.node;
300
301 /* Excludes PER_CPU and NO_BALANCE interrupts */
302 if (!irq_can_set_affinity(irq))
303 return 0;
304
305 /*
306 * Preserve an userspace affinity setup, but make sure that
307 * one of the targets is online.
308 */
309 if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
310 if (cpumask_intersects(desc->irq_data.affinity,
311 cpu_online_mask))
312 set = desc->irq_data.affinity;
313 else
314 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
315 }
316
317 cpumask_and(mask, cpu_online_mask, set);
318 if (node != NUMA_NO_NODE) {
319 const struct cpumask *nodemask = cpumask_of_node(node);
320
321 /* make sure at least one of the cpus in nodemask is online */
322 if (cpumask_intersects(mask, nodemask))
323 cpumask_and(mask, mask, nodemask);
324 }
325 irq_do_set_affinity(&desc->irq_data, mask, false);
326 return 0;
327}
328#else
329static inline int
330setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
331{
332 return irq_select_affinity(irq);
333}
334#endif
335
336/*
337 * Called when affinity is set via /proc/irq
338 */
339int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
340{
341 struct irq_desc *desc = irq_to_desc(irq);
342 unsigned long flags;
343 int ret;
344
345 raw_spin_lock_irqsave(&desc->lock, flags);
346 ret = setup_affinity(irq, desc, mask);
347 raw_spin_unlock_irqrestore(&desc->lock, flags);
348 return ret;
349}
350
351#else
352static inline int
353setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
354{
355 return 0;
356}
357#endif
358
359void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
360{
361 if (suspend) {
362 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
363 return;
364 desc->istate |= IRQS_SUSPENDED;
365 }
366
367 if (!desc->depth++)
368 irq_disable(desc);
369}
370
371static int __disable_irq_nosync(unsigned int irq)
372{
373 unsigned long flags;
374 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
375
376 if (!desc)
377 return -EINVAL;
378 __disable_irq(desc, irq, false);
379 irq_put_desc_busunlock(desc, flags);
380 return 0;
381}
382
383/**
384 * disable_irq_nosync - disable an irq without waiting
385 * @irq: Interrupt to disable
386 *
387 * Disable the selected interrupt line. Disables and Enables are
388 * nested.
389 * Unlike disable_irq(), this function does not ensure existing
390 * instances of the IRQ handler have completed before returning.
391 *
392 * This function may be called from IRQ context.
393 */
394void disable_irq_nosync(unsigned int irq)
395{
396 __disable_irq_nosync(irq);
397}
398EXPORT_SYMBOL(disable_irq_nosync);
399
400/**
401 * disable_irq - disable an irq and wait for completion
402 * @irq: Interrupt to disable
403 *
404 * Disable the selected interrupt line. Enables and Disables are
405 * nested.
406 * This function waits for any pending IRQ handlers for this interrupt
407 * to complete before returning. If you use this function while
408 * holding a resource the IRQ handler may need you will deadlock.
409 *
410 * This function may be called - with care - from IRQ context.
411 */
412void disable_irq(unsigned int irq)
413{
414 if (!__disable_irq_nosync(irq))
415 synchronize_irq(irq);
416}
417EXPORT_SYMBOL(disable_irq);
418
419void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
420{
421 if (resume) {
422 if (!(desc->istate & IRQS_SUSPENDED)) {
423 if (!desc->action)
424 return;
425 if (!(desc->action->flags & IRQF_FORCE_RESUME))
426 return;
427 /* Pretend that it got disabled ! */
428 desc->depth++;
429 }
430 desc->istate &= ~IRQS_SUSPENDED;
431 }
432
433 switch (desc->depth) {
434 case 0:
435 err_out:
436 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
437 break;
438 case 1: {
439 if (desc->istate & IRQS_SUSPENDED)
440 goto err_out;
441 /* Prevent probing on this irq: */
442 irq_settings_set_noprobe(desc);
443 irq_enable(desc);
444 check_irq_resend(desc, irq);
445 /* fall-through */
446 }
447 default:
448 desc->depth--;
449 }
450}
451
452/**
453 * enable_irq - enable handling of an irq
454 * @irq: Interrupt to enable
455 *
456 * Undoes the effect of one call to disable_irq(). If this
457 * matches the last disable, processing of interrupts on this
458 * IRQ line is re-enabled.
459 *
460 * This function may be called from IRQ context only when
461 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
462 */
463void enable_irq(unsigned int irq)
464{
465 unsigned long flags;
466 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
467
468 if (!desc)
469 return;
470 if (WARN(!desc->irq_data.chip,
471 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
472 goto out;
473
474 __enable_irq(desc, irq, false);
475out:
476 irq_put_desc_busunlock(desc, flags);
477}
478EXPORT_SYMBOL(enable_irq);
479
480static int set_irq_wake_real(unsigned int irq, unsigned int on)
481{
482 struct irq_desc *desc = irq_to_desc(irq);
483 int ret = -ENXIO;
484
485 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
486 return 0;
487
488 if (desc->irq_data.chip->irq_set_wake)
489 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
490
491 return ret;
492}
493
494/**
495 * irq_set_irq_wake - control irq power management wakeup
496 * @irq: interrupt to control
497 * @on: enable/disable power management wakeup
498 *
499 * Enable/disable power management wakeup mode, which is
500 * disabled by default. Enables and disables must match,
501 * just as they match for non-wakeup mode support.
502 *
503 * Wakeup mode lets this IRQ wake the system from sleep
504 * states like "suspend to RAM".
505 */
506int irq_set_irq_wake(unsigned int irq, unsigned int on)
507{
508 unsigned long flags;
509 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
510 int ret = 0;
511
512 if (!desc)
513 return -EINVAL;
514
515 /* wakeup-capable irqs can be shared between drivers that
516 * don't need to have the same sleep mode behaviors.
517 */
518 if (on) {
519 if (desc->wake_depth++ == 0) {
520 ret = set_irq_wake_real(irq, on);
521 if (ret)
522 desc->wake_depth = 0;
523 else
524 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
525 }
526 } else {
527 if (desc->wake_depth == 0) {
528 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
529 } else if (--desc->wake_depth == 0) {
530 ret = set_irq_wake_real(irq, on);
531 if (ret)
532 desc->wake_depth = 1;
533 else
534 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
535 }
536 }
537 irq_put_desc_busunlock(desc, flags);
538 return ret;
539}
540EXPORT_SYMBOL(irq_set_irq_wake);
541
542/*
543 * Internal function that tells the architecture code whether a
544 * particular irq has been exclusively allocated or is available
545 * for driver use.
546 */
547int can_request_irq(unsigned int irq, unsigned long irqflags)
548{
549 unsigned long flags;
550 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
551 int canrequest = 0;
552
553 if (!desc)
554 return 0;
555
556 if (irq_settings_can_request(desc)) {
557 if (desc->action)
558 if (irqflags & desc->action->flags & IRQF_SHARED)
559 canrequest =1;
560 }
561 irq_put_desc_unlock(desc, flags);
562 return canrequest;
563}
564
565int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
566 unsigned long flags)
567{
568 struct irq_chip *chip = desc->irq_data.chip;
569 int ret, unmask = 0;
570
571 if (!chip || !chip->irq_set_type) {
572 /*
573 * IRQF_TRIGGER_* but the PIC does not support multiple
574 * flow-types?
575 */
576 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
577 chip ? (chip->name ? : "unknown") : "unknown");
578 return 0;
579 }
580
581 flags &= IRQ_TYPE_SENSE_MASK;
582
583 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
584 if (!irqd_irq_masked(&desc->irq_data))
585 mask_irq(desc);
586 if (!irqd_irq_disabled(&desc->irq_data))
587 unmask = 1;
588 }
589
590 /* caller masked out all except trigger mode flags */
591 ret = chip->irq_set_type(&desc->irq_data, flags);
592
593 switch (ret) {
594 case IRQ_SET_MASK_OK:
595 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
596 irqd_set(&desc->irq_data, flags);
597
598 case IRQ_SET_MASK_OK_NOCOPY:
599 flags = irqd_get_trigger_type(&desc->irq_data);
600 irq_settings_set_trigger_mask(desc, flags);
601 irqd_clear(&desc->irq_data, IRQD_LEVEL);
602 irq_settings_clr_level(desc);
603 if (flags & IRQ_TYPE_LEVEL_MASK) {
604 irq_settings_set_level(desc);
605 irqd_set(&desc->irq_data, IRQD_LEVEL);
606 }
607
608 ret = 0;
609 break;
610 default:
611 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
612 flags, irq, chip->irq_set_type);
613 }
614 if (unmask)
615 unmask_irq(desc);
616 return ret;
617}
618
619/*
620 * Default primary interrupt handler for threaded interrupts. Is
621 * assigned as primary handler when request_threaded_irq is called
622 * with handler == NULL. Useful for oneshot interrupts.
623 */
624static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
625{
626 return IRQ_WAKE_THREAD;
627}
628
629/*
630 * Primary handler for nested threaded interrupts. Should never be
631 * called.
632 */
633static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
634{
635 WARN(1, "Primary handler called for nested irq %d\n", irq);
636 return IRQ_NONE;
637}
638
639static int irq_wait_for_interrupt(struct irqaction *action)
640{
641 set_current_state(TASK_INTERRUPTIBLE);
642
643 while (!kthread_should_stop()) {
644
645 if (test_and_clear_bit(IRQTF_RUNTHREAD,
646 &action->thread_flags)) {
647 __set_current_state(TASK_RUNNING);
648 return 0;
649 }
650 schedule();
651 set_current_state(TASK_INTERRUPTIBLE);
652 }
653 __set_current_state(TASK_RUNNING);
654 return -1;
655}
656
657/*
658 * Oneshot interrupts keep the irq line masked until the threaded
659 * handler finished. unmask if the interrupt has not been disabled and
660 * is marked MASKED.
661 */
662static void irq_finalize_oneshot(struct irq_desc *desc,
663 struct irqaction *action)
664{
665 if (!(desc->istate & IRQS_ONESHOT))
666 return;
667again:
668 chip_bus_lock(desc);
669 raw_spin_lock_irq(&desc->lock);
670
671 /*
672 * Implausible though it may be we need to protect us against
673 * the following scenario:
674 *
675 * The thread is faster done than the hard interrupt handler
676 * on the other CPU. If we unmask the irq line then the
677 * interrupt can come in again and masks the line, leaves due
678 * to IRQS_INPROGRESS and the irq line is masked forever.
679 *
680 * This also serializes the state of shared oneshot handlers
681 * versus "desc->threads_onehsot |= action->thread_mask;" in
682 * irq_wake_thread(). See the comment there which explains the
683 * serialization.
684 */
685 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
686 raw_spin_unlock_irq(&desc->lock);
687 chip_bus_sync_unlock(desc);
688 cpu_relax();
689 goto again;
690 }
691
692 /*
693 * Now check again, whether the thread should run. Otherwise
694 * we would clear the threads_oneshot bit of this thread which
695 * was just set.
696 */
697 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
698 goto out_unlock;
699
700 desc->threads_oneshot &= ~action->thread_mask;
701
702 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
703 irqd_irq_masked(&desc->irq_data))
704 unmask_irq(desc);
705
706out_unlock:
707 raw_spin_unlock_irq(&desc->lock);
708 chip_bus_sync_unlock(desc);
709}
710
711#ifdef CONFIG_SMP
712/*
713 * Check whether we need to chasnge the affinity of the interrupt thread.
714 */
715static void
716irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
717{
718 cpumask_var_t mask;
719
720 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
721 return;
722
723 /*
724 * In case we are out of memory we set IRQTF_AFFINITY again and
725 * try again next time
726 */
727 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
728 set_bit(IRQTF_AFFINITY, &action->thread_flags);
729 return;
730 }
731
732 raw_spin_lock_irq(&desc->lock);
733 cpumask_copy(mask, desc->irq_data.affinity);
734 raw_spin_unlock_irq(&desc->lock);
735
736 set_cpus_allowed_ptr(current, mask);
737 free_cpumask_var(mask);
738}
739#else
740static inline void
741irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
742#endif
743
744/*
745 * Interrupts which are not explicitely requested as threaded
746 * interrupts rely on the implicit bh/preempt disable of the hard irq
747 * context. So we need to disable bh here to avoid deadlocks and other
748 * side effects.
749 */
750static irqreturn_t
751irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
752{
753 irqreturn_t ret;
754
755 local_bh_disable();
756 ret = action->thread_fn(action->irq, action->dev_id);
757 irq_finalize_oneshot(desc, action);
758 local_bh_enable();
759 return ret;
760}
761
762/*
763 * Interrupts explicitely requested as threaded interupts want to be
764 * preemtible - many of them need to sleep and wait for slow busses to
765 * complete.
766 */
767static irqreturn_t irq_thread_fn(struct irq_desc *desc,
768 struct irqaction *action)
769{
770 irqreturn_t ret;
771
772 ret = action->thread_fn(action->irq, action->dev_id);
773 irq_finalize_oneshot(desc, action);
774 return ret;
775}
776
777static void wake_threads_waitq(struct irq_desc *desc)
778{
779 if (atomic_dec_and_test(&desc->threads_active) &&
780 waitqueue_active(&desc->wait_for_threads))
781 wake_up(&desc->wait_for_threads);
782}
783
784static void irq_thread_dtor(struct task_work *unused)
785{
786 struct task_struct *tsk = current;
787 struct irq_desc *desc;
788 struct irqaction *action;
789
790 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
791 return;
792
793 action = kthread_data(tsk);
794
795 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
796 tsk->comm ? tsk->comm : "", tsk->pid, action->irq);
797
798
799 desc = irq_to_desc(action->irq);
800 /*
801 * If IRQTF_RUNTHREAD is set, we need to decrement
802 * desc->threads_active and wake possible waiters.
803 */
804 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
805 wake_threads_waitq(desc);
806
807 /* Prevent a stale desc->threads_oneshot */
808 irq_finalize_oneshot(desc, action);
809}
810
811/*
812 * Interrupt handler thread
813 */
814static int irq_thread(void *data)
815{
816 struct task_work on_exit_work;
817 static const struct sched_param param = {
818 .sched_priority = MAX_USER_RT_PRIO/2,
819 };
820 struct irqaction *action = data;
821 struct irq_desc *desc = irq_to_desc(action->irq);
822 irqreturn_t (*handler_fn)(struct irq_desc *desc,
823 struct irqaction *action);
824
825 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
826 &action->thread_flags))
827 handler_fn = irq_forced_thread_fn;
828 else
829 handler_fn = irq_thread_fn;
830
831 sched_setscheduler(current, SCHED_FIFO, ¶m);
832
833 init_task_work(&on_exit_work, irq_thread_dtor, NULL);
834 task_work_add(current, &on_exit_work, false);
835
836 while (!irq_wait_for_interrupt(action)) {
837 irqreturn_t action_ret;
838
839 irq_thread_check_affinity(desc, action);
840
841 action_ret = handler_fn(desc, action);
842 if (!noirqdebug)
843 note_interrupt(action->irq, desc, action_ret);
844
845 wake_threads_waitq(desc);
846 }
847
848 /*
849 * This is the regular exit path. __free_irq() is stopping the
850 * thread via kthread_stop() after calling
851 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
852 * oneshot mask bit can be set. We cannot verify that as we
853 * cannot touch the oneshot mask at this point anymore as
854 * __setup_irq() might have given out currents thread_mask
855 * again.
856 */
857 task_work_cancel(current, irq_thread_dtor);
858 return 0;
859}
860
861static void irq_setup_forced_threading(struct irqaction *new)
862{
863 if (!force_irqthreads)
864 return;
865 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
866 return;
867
868 new->flags |= IRQF_ONESHOT;
869
870 if (!new->thread_fn) {
871 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
872 new->thread_fn = new->handler;
873 new->handler = irq_default_primary_handler;
874 }
875}
876
877/*
878 * Internal function to register an irqaction - typically used to
879 * allocate special interrupts that are part of the architecture.
880 */
881static int
882__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
883{
884 struct irqaction *old, **old_ptr;
885 unsigned long flags, thread_mask = 0;
886 int ret, nested, shared = 0;
887 cpumask_var_t mask;
888
889 if (!desc)
890 return -EINVAL;
891
892 if (desc->irq_data.chip == &no_irq_chip)
893 return -ENOSYS;
894 if (!try_module_get(desc->owner))
895 return -ENODEV;
896
897 /*
898 * Check whether the interrupt nests into another interrupt
899 * thread.
900 */
901 nested = irq_settings_is_nested_thread(desc);
902 if (nested) {
903 if (!new->thread_fn) {
904 ret = -EINVAL;
905 goto out_mput;
906 }
907 /*
908 * Replace the primary handler which was provided from
909 * the driver for non nested interrupt handling by the
910 * dummy function which warns when called.
911 */
912 new->handler = irq_nested_primary_handler;
913 } else {
914 if (irq_settings_can_thread(desc))
915 irq_setup_forced_threading(new);
916 }
917
918 /*
919 * Create a handler thread when a thread function is supplied
920 * and the interrupt does not nest into another interrupt
921 * thread.
922 */
923 if (new->thread_fn && !nested) {
924 struct task_struct *t;
925
926 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
927 new->name);
928 if (IS_ERR(t)) {
929 ret = PTR_ERR(t);
930 goto out_mput;
931 }
932 /*
933 * We keep the reference to the task struct even if
934 * the thread dies to avoid that the interrupt code
935 * references an already freed task_struct.
936 */
937 get_task_struct(t);
938 new->thread = t;
939 }
940
941 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
942 ret = -ENOMEM;
943 goto out_thread;
944 }
945
946 /*
947 * The following block of code has to be executed atomically
948 */
949 raw_spin_lock_irqsave(&desc->lock, flags);
950 old_ptr = &desc->action;
951 old = *old_ptr;
952 if (old) {
953 /*
954 * Can't share interrupts unless both agree to and are
955 * the same type (level, edge, polarity). So both flag
956 * fields must have IRQF_SHARED set and the bits which
957 * set the trigger type must match. Also all must
958 * agree on ONESHOT.
959 */
960 if (!((old->flags & new->flags) & IRQF_SHARED) ||
961 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
962 ((old->flags ^ new->flags) & IRQF_ONESHOT))
963 goto mismatch;
964
965 /* All handlers must agree on per-cpuness */
966 if ((old->flags & IRQF_PERCPU) !=
967 (new->flags & IRQF_PERCPU))
968 goto mismatch;
969
970 /* add new interrupt at end of irq queue */
971 do {
972 /*
973 * Or all existing action->thread_mask bits,
974 * so we can find the next zero bit for this
975 * new action.
976 */
977 thread_mask |= old->thread_mask;
978 old_ptr = &old->next;
979 old = *old_ptr;
980 } while (old);
981 shared = 1;
982 }
983
984 /*
985 * Setup the thread mask for this irqaction for ONESHOT. For
986 * !ONESHOT irqs the thread mask is 0 so we can avoid a
987 * conditional in irq_wake_thread().
988 */
989 if (new->flags & IRQF_ONESHOT) {
990 /*
991 * Unlikely to have 32 resp 64 irqs sharing one line,
992 * but who knows.
993 */
994 if (thread_mask == ~0UL) {
995 ret = -EBUSY;
996 goto out_mask;
997 }
998 /*
999 * The thread_mask for the action is or'ed to
1000 * desc->thread_active to indicate that the
1001 * IRQF_ONESHOT thread handler has been woken, but not
1002 * yet finished. The bit is cleared when a thread
1003 * completes. When all threads of a shared interrupt
1004 * line have completed desc->threads_active becomes
1005 * zero and the interrupt line is unmasked. See
1006 * handle.c:irq_wake_thread() for further information.
1007 *
1008 * If no thread is woken by primary (hard irq context)
1009 * interrupt handlers, then desc->threads_active is
1010 * also checked for zero to unmask the irq line in the
1011 * affected hard irq flow handlers
1012 * (handle_[fasteoi|level]_irq).
1013 *
1014 * The new action gets the first zero bit of
1015 * thread_mask assigned. See the loop above which or's
1016 * all existing action->thread_mask bits.
1017 */
1018 new->thread_mask = 1 << ffz(thread_mask);
1019
1020 } else if (new->handler == irq_default_primary_handler) {
1021 /*
1022 * The interrupt was requested with handler = NULL, so
1023 * we use the default primary handler for it. But it
1024 * does not have the oneshot flag set. In combination
1025 * with level interrupts this is deadly, because the
1026 * default primary handler just wakes the thread, then
1027 * the irq lines is reenabled, but the device still
1028 * has the level irq asserted. Rinse and repeat....
1029 *
1030 * While this works for edge type interrupts, we play
1031 * it safe and reject unconditionally because we can't
1032 * say for sure which type this interrupt really
1033 * has. The type flags are unreliable as the
1034 * underlying chip implementation can override them.
1035 */
1036 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1037 irq);
1038 ret = -EINVAL;
1039 goto out_mask;
1040 }
1041
1042 if (!shared) {
1043 init_waitqueue_head(&desc->wait_for_threads);
1044
1045 /* Setup the type (level, edge polarity) if configured: */
1046 if (new->flags & IRQF_TRIGGER_MASK) {
1047 ret = __irq_set_trigger(desc, irq,
1048 new->flags & IRQF_TRIGGER_MASK);
1049
1050 if (ret)
1051 goto out_mask;
1052 }
1053
1054 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1055 IRQS_ONESHOT | IRQS_WAITING);
1056 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1057
1058 if (new->flags & IRQF_PERCPU) {
1059 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1060 irq_settings_set_per_cpu(desc);
1061 }
1062
1063 if (new->flags & IRQF_ONESHOT)
1064 desc->istate |= IRQS_ONESHOT;
1065
1066 if (irq_settings_can_autoenable(desc))
1067 irq_startup(desc, true);
1068 else
1069 /* Undo nested disables: */
1070 desc->depth = 1;
1071
1072 /* Exclude IRQ from balancing if requested */
1073 if (new->flags & IRQF_NOBALANCING) {
1074 irq_settings_set_no_balancing(desc);
1075 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1076 }
1077
1078 /* Set default affinity mask once everything is setup */
1079 setup_affinity(irq, desc, mask);
1080
1081 } else if (new->flags & IRQF_TRIGGER_MASK) {
1082 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1083 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1084
1085 if (nmsk != omsk)
1086 /* hope the handler works with current trigger mode */
1087 pr_warning("irq %d uses trigger mode %u; requested %u\n",
1088 irq, nmsk, omsk);
1089 }
1090
1091 new->irq = irq;
1092 *old_ptr = new;
1093
1094 /* Reset broken irq detection when installing new handler */
1095 desc->irq_count = 0;
1096 desc->irqs_unhandled = 0;
1097
1098 /*
1099 * Check whether we disabled the irq via the spurious handler
1100 * before. Reenable it and give it another chance.
1101 */
1102 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1103 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1104 __enable_irq(desc, irq, false);
1105 }
1106
1107 raw_spin_unlock_irqrestore(&desc->lock, flags);
1108
1109 /*
1110 * Strictly no need to wake it up, but hung_task complains
1111 * when no hard interrupt wakes the thread up.
1112 */
1113 if (new->thread)
1114 wake_up_process(new->thread);
1115
1116 register_irq_proc(irq, desc);
1117 new->dir = NULL;
1118 register_handler_proc(irq, new);
1119 free_cpumask_var(mask);
1120
1121 return 0;
1122
1123mismatch:
1124 if (!(new->flags & IRQF_PROBE_SHARED)) {
1125 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1126 irq, new->flags, new->name, old->flags, old->name);
1127#ifdef CONFIG_DEBUG_SHIRQ
1128 dump_stack();
1129#endif
1130 }
1131 ret = -EBUSY;
1132
1133out_mask:
1134 raw_spin_unlock_irqrestore(&desc->lock, flags);
1135 free_cpumask_var(mask);
1136
1137out_thread:
1138 if (new->thread) {
1139 struct task_struct *t = new->thread;
1140
1141 new->thread = NULL;
1142 kthread_stop(t);
1143 put_task_struct(t);
1144 }
1145out_mput:
1146 module_put(desc->owner);
1147 return ret;
1148}
1149
1150/**
1151 * setup_irq - setup an interrupt
1152 * @irq: Interrupt line to setup
1153 * @act: irqaction for the interrupt
1154 *
1155 * Used to statically setup interrupts in the early boot process.
1156 */
1157int setup_irq(unsigned int irq, struct irqaction *act)
1158{
1159 int retval;
1160 struct irq_desc *desc = irq_to_desc(irq);
1161
1162 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1163 return -EINVAL;
1164 chip_bus_lock(desc);
1165 retval = __setup_irq(irq, desc, act);
1166 chip_bus_sync_unlock(desc);
1167
1168 return retval;
1169}
1170EXPORT_SYMBOL_GPL(setup_irq);
1171
1172/*
1173 * Internal function to unregister an irqaction - used to free
1174 * regular and special interrupts that are part of the architecture.
1175 */
1176static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1177{
1178 struct irq_desc *desc = irq_to_desc(irq);
1179 struct irqaction *action, **action_ptr;
1180 unsigned long flags;
1181
1182 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1183
1184 if (!desc)
1185 return NULL;
1186
1187 raw_spin_lock_irqsave(&desc->lock, flags);
1188
1189 /*
1190 * There can be multiple actions per IRQ descriptor, find the right
1191 * one based on the dev_id:
1192 */
1193 action_ptr = &desc->action;
1194 for (;;) {
1195 action = *action_ptr;
1196
1197 if (!action) {
1198 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1199 raw_spin_unlock_irqrestore(&desc->lock, flags);
1200
1201 return NULL;
1202 }
1203
1204 if (action->dev_id == dev_id)
1205 break;
1206 action_ptr = &action->next;
1207 }
1208
1209 /* Found it - now remove it from the list of entries: */
1210 *action_ptr = action->next;
1211
1212 /* If this was the last handler, shut down the IRQ line: */
1213 if (!desc->action)
1214 irq_shutdown(desc);
1215
1216#ifdef CONFIG_SMP
1217 /* make sure affinity_hint is cleaned up */
1218 if (WARN_ON_ONCE(desc->affinity_hint))
1219 desc->affinity_hint = NULL;
1220#endif
1221
1222 raw_spin_unlock_irqrestore(&desc->lock, flags);
1223
1224 unregister_handler_proc(irq, action);
1225
1226 /* Make sure it's not being used on another CPU: */
1227 synchronize_irq(irq);
1228
1229#ifdef CONFIG_DEBUG_SHIRQ
1230 /*
1231 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1232 * event to happen even now it's being freed, so let's make sure that
1233 * is so by doing an extra call to the handler ....
1234 *
1235 * ( We do this after actually deregistering it, to make sure that a
1236 * 'real' IRQ doesn't run in * parallel with our fake. )
1237 */
1238 if (action->flags & IRQF_SHARED) {
1239 local_irq_save(flags);
1240 action->handler(irq, dev_id);
1241 local_irq_restore(flags);
1242 }
1243#endif
1244
1245 if (action->thread) {
1246 kthread_stop(action->thread);
1247 put_task_struct(action->thread);
1248 }
1249
1250 module_put(desc->owner);
1251 return action;
1252}
1253
1254/**
1255 * remove_irq - free an interrupt
1256 * @irq: Interrupt line to free
1257 * @act: irqaction for the interrupt
1258 *
1259 * Used to remove interrupts statically setup by the early boot process.
1260 */
1261void remove_irq(unsigned int irq, struct irqaction *act)
1262{
1263 struct irq_desc *desc = irq_to_desc(irq);
1264
1265 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1266 __free_irq(irq, act->dev_id);
1267}
1268EXPORT_SYMBOL_GPL(remove_irq);
1269
1270/**
1271 * free_irq - free an interrupt allocated with request_irq
1272 * @irq: Interrupt line to free
1273 * @dev_id: Device identity to free
1274 *
1275 * Remove an interrupt handler. The handler is removed and if the
1276 * interrupt line is no longer in use by any driver it is disabled.
1277 * On a shared IRQ the caller must ensure the interrupt is disabled
1278 * on the card it drives before calling this function. The function
1279 * does not return until any executing interrupts for this IRQ
1280 * have completed.
1281 *
1282 * This function must not be called from interrupt context.
1283 */
1284void free_irq(unsigned int irq, void *dev_id)
1285{
1286 struct irq_desc *desc = irq_to_desc(irq);
1287
1288 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1289 return;
1290
1291#ifdef CONFIG_SMP
1292 if (WARN_ON(desc->affinity_notify))
1293 desc->affinity_notify = NULL;
1294#endif
1295
1296 chip_bus_lock(desc);
1297 kfree(__free_irq(irq, dev_id));
1298 chip_bus_sync_unlock(desc);
1299}
1300EXPORT_SYMBOL(free_irq);
1301
1302/**
1303 * request_threaded_irq - allocate an interrupt line
1304 * @irq: Interrupt line to allocate
1305 * @handler: Function to be called when the IRQ occurs.
1306 * Primary handler for threaded interrupts
1307 * If NULL and thread_fn != NULL the default
1308 * primary handler is installed
1309 * @thread_fn: Function called from the irq handler thread
1310 * If NULL, no irq thread is created
1311 * @irqflags: Interrupt type flags
1312 * @devname: An ascii name for the claiming device
1313 * @dev_id: A cookie passed back to the handler function
1314 *
1315 * This call allocates interrupt resources and enables the
1316 * interrupt line and IRQ handling. From the point this
1317 * call is made your handler function may be invoked. Since
1318 * your handler function must clear any interrupt the board
1319 * raises, you must take care both to initialise your hardware
1320 * and to set up the interrupt handler in the right order.
1321 *
1322 * If you want to set up a threaded irq handler for your device
1323 * then you need to supply @handler and @thread_fn. @handler is
1324 * still called in hard interrupt context and has to check
1325 * whether the interrupt originates from the device. If yes it
1326 * needs to disable the interrupt on the device and return
1327 * IRQ_WAKE_THREAD which will wake up the handler thread and run
1328 * @thread_fn. This split handler design is necessary to support
1329 * shared interrupts.
1330 *
1331 * Dev_id must be globally unique. Normally the address of the
1332 * device data structure is used as the cookie. Since the handler
1333 * receives this value it makes sense to use it.
1334 *
1335 * If your interrupt is shared you must pass a non NULL dev_id
1336 * as this is required when freeing the interrupt.
1337 *
1338 * Flags:
1339 *
1340 * IRQF_SHARED Interrupt is shared
1341 * IRQF_TRIGGER_* Specify active edge(s) or level
1342 *
1343 */
1344int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1345 irq_handler_t thread_fn, unsigned long irqflags,
1346 const char *devname, void *dev_id)
1347{
1348 struct irqaction *action;
1349 struct irq_desc *desc;
1350 int retval;
1351
1352 /*
1353 * Sanity-check: shared interrupts must pass in a real dev-ID,
1354 * otherwise we'll have trouble later trying to figure out
1355 * which interrupt is which (messes up the interrupt freeing
1356 * logic etc).
1357 */
1358 if ((irqflags & IRQF_SHARED) && !dev_id)
1359 return -EINVAL;
1360
1361 desc = irq_to_desc(irq);
1362 if (!desc)
1363 return -EINVAL;
1364
1365 if (!irq_settings_can_request(desc) ||
1366 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1367 return -EINVAL;
1368
1369 if (!handler) {
1370 if (!thread_fn)
1371 return -EINVAL;
1372 handler = irq_default_primary_handler;
1373 }
1374
1375 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1376 if (!action)
1377 return -ENOMEM;
1378
1379 action->handler = handler;
1380 action->thread_fn = thread_fn;
1381 action->flags = irqflags;
1382 action->name = devname;
1383 action->dev_id = dev_id;
1384
1385 chip_bus_lock(desc);
1386 retval = __setup_irq(irq, desc, action);
1387 chip_bus_sync_unlock(desc);
1388
1389 if (retval)
1390 kfree(action);
1391
1392#ifdef CONFIG_DEBUG_SHIRQ_FIXME
1393 if (!retval && (irqflags & IRQF_SHARED)) {
1394 /*
1395 * It's a shared IRQ -- the driver ought to be prepared for it
1396 * to happen immediately, so let's make sure....
1397 * We disable the irq to make sure that a 'real' IRQ doesn't
1398 * run in parallel with our fake.
1399 */
1400 unsigned long flags;
1401
1402 disable_irq(irq);
1403 local_irq_save(flags);
1404
1405 handler(irq, dev_id);
1406
1407 local_irq_restore(flags);
1408 enable_irq(irq);
1409 }
1410#endif
1411 return retval;
1412}
1413EXPORT_SYMBOL(request_threaded_irq);
1414
1415/**
1416 * request_any_context_irq - allocate an interrupt line
1417 * @irq: Interrupt line to allocate
1418 * @handler: Function to be called when the IRQ occurs.
1419 * Threaded handler for threaded interrupts.
1420 * @flags: Interrupt type flags
1421 * @name: An ascii name for the claiming device
1422 * @dev_id: A cookie passed back to the handler function
1423 *
1424 * This call allocates interrupt resources and enables the
1425 * interrupt line and IRQ handling. It selects either a
1426 * hardirq or threaded handling method depending on the
1427 * context.
1428 *
1429 * On failure, it returns a negative value. On success,
1430 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1431 */
1432int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1433 unsigned long flags, const char *name, void *dev_id)
1434{
1435 struct irq_desc *desc = irq_to_desc(irq);
1436 int ret;
1437
1438 if (!desc)
1439 return -EINVAL;
1440
1441 if (irq_settings_is_nested_thread(desc)) {
1442 ret = request_threaded_irq(irq, NULL, handler,
1443 flags, name, dev_id);
1444 return !ret ? IRQC_IS_NESTED : ret;
1445 }
1446
1447 ret = request_irq(irq, handler, flags, name, dev_id);
1448 return !ret ? IRQC_IS_HARDIRQ : ret;
1449}
1450EXPORT_SYMBOL_GPL(request_any_context_irq);
1451
1452void enable_percpu_irq(unsigned int irq, unsigned int type)
1453{
1454 unsigned int cpu = smp_processor_id();
1455 unsigned long flags;
1456 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1457
1458 if (!desc)
1459 return;
1460
1461 type &= IRQ_TYPE_SENSE_MASK;
1462 if (type != IRQ_TYPE_NONE) {
1463 int ret;
1464
1465 ret = __irq_set_trigger(desc, irq, type);
1466
1467 if (ret) {
1468 WARN(1, "failed to set type for IRQ%d\n", irq);
1469 goto out;
1470 }
1471 }
1472
1473 irq_percpu_enable(desc, cpu);
1474out:
1475 irq_put_desc_unlock(desc, flags);
1476}
1477
1478void disable_percpu_irq(unsigned int irq)
1479{
1480 unsigned int cpu = smp_processor_id();
1481 unsigned long flags;
1482 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1483
1484 if (!desc)
1485 return;
1486
1487 irq_percpu_disable(desc, cpu);
1488 irq_put_desc_unlock(desc, flags);
1489}
1490
1491/*
1492 * Internal function to unregister a percpu irqaction.
1493 */
1494static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1495{
1496 struct irq_desc *desc = irq_to_desc(irq);
1497 struct irqaction *action;
1498 unsigned long flags;
1499
1500 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1501
1502 if (!desc)
1503 return NULL;
1504
1505 raw_spin_lock_irqsave(&desc->lock, flags);
1506
1507 action = desc->action;
1508 if (!action || action->percpu_dev_id != dev_id) {
1509 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1510 goto bad;
1511 }
1512
1513 if (!cpumask_empty(desc->percpu_enabled)) {
1514 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1515 irq, cpumask_first(desc->percpu_enabled));
1516 goto bad;
1517 }
1518
1519 /* Found it - now remove it from the list of entries: */
1520 desc->action = NULL;
1521
1522 raw_spin_unlock_irqrestore(&desc->lock, flags);
1523
1524 unregister_handler_proc(irq, action);
1525
1526 module_put(desc->owner);
1527 return action;
1528
1529bad:
1530 raw_spin_unlock_irqrestore(&desc->lock, flags);
1531 return NULL;
1532}
1533
1534/**
1535 * remove_percpu_irq - free a per-cpu interrupt
1536 * @irq: Interrupt line to free
1537 * @act: irqaction for the interrupt
1538 *
1539 * Used to remove interrupts statically setup by the early boot process.
1540 */
1541void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1542{
1543 struct irq_desc *desc = irq_to_desc(irq);
1544
1545 if (desc && irq_settings_is_per_cpu_devid(desc))
1546 __free_percpu_irq(irq, act->percpu_dev_id);
1547}
1548
1549/**
1550 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
1551 * @irq: Interrupt line to free
1552 * @dev_id: Device identity to free
1553 *
1554 * Remove a percpu interrupt handler. The handler is removed, but
1555 * the interrupt line is not disabled. This must be done on each
1556 * CPU before calling this function. The function does not return
1557 * until any executing interrupts for this IRQ have completed.
1558 *
1559 * This function must not be called from interrupt context.
1560 */
1561void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1562{
1563 struct irq_desc *desc = irq_to_desc(irq);
1564
1565 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1566 return;
1567
1568 chip_bus_lock(desc);
1569 kfree(__free_percpu_irq(irq, dev_id));
1570 chip_bus_sync_unlock(desc);
1571}
1572
1573/**
1574 * setup_percpu_irq - setup a per-cpu interrupt
1575 * @irq: Interrupt line to setup
1576 * @act: irqaction for the interrupt
1577 *
1578 * Used to statically setup per-cpu interrupts in the early boot process.
1579 */
1580int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1581{
1582 struct irq_desc *desc = irq_to_desc(irq);
1583 int retval;
1584
1585 if (!desc || !irq_settings_is_per_cpu_devid(desc))
1586 return -EINVAL;
1587 chip_bus_lock(desc);
1588 retval = __setup_irq(irq, desc, act);
1589 chip_bus_sync_unlock(desc);
1590
1591 return retval;
1592}
1593
1594/**
1595 * request_percpu_irq - allocate a percpu interrupt line
1596 * @irq: Interrupt line to allocate
1597 * @handler: Function to be called when the IRQ occurs.
1598 * @devname: An ascii name for the claiming device
1599 * @dev_id: A percpu cookie passed back to the handler function
1600 *
1601 * This call allocates interrupt resources, but doesn't
1602 * automatically enable the interrupt. It has to be done on each
1603 * CPU using enable_percpu_irq().
1604 *
1605 * Dev_id must be globally unique. It is a per-cpu variable, and
1606 * the handler gets called with the interrupted CPU's instance of
1607 * that variable.
1608 */
1609int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1610 const char *devname, void __percpu *dev_id)
1611{
1612 struct irqaction *action;
1613 struct irq_desc *desc;
1614 int retval;
1615
1616 if (!dev_id)
1617 return -EINVAL;
1618
1619 desc = irq_to_desc(irq);
1620 if (!desc || !irq_settings_can_request(desc) ||
1621 !irq_settings_is_per_cpu_devid(desc))
1622 return -EINVAL;
1623
1624 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1625 if (!action)
1626 return -ENOMEM;
1627
1628 action->handler = handler;
1629 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1630 action->name = devname;
1631 action->percpu_dev_id = dev_id;
1632
1633 chip_bus_lock(desc);
1634 retval = __setup_irq(irq, desc, action);
1635 chip_bus_sync_unlock(desc);
1636
1637 if (retval)
1638 kfree(action);
1639
1640 return retval;
1641}