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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
111/**
112 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
113 * @irq: interrupt number to wait for
114 *
115 * This function waits for any pending IRQ handlers for this interrupt
116 * to complete before returning. If you use this function while
117 * holding a resource the IRQ handler may need you will deadlock.
118 *
119 * Can only be called from preemptible code as it might sleep when
120 * an interrupt thread is associated to @irq.
121 *
122 * It optionally makes sure (when the irq chip supports that method)
123 * that the interrupt is not pending in any CPU and waiting for
124 * service.
125 */
126void synchronize_irq(unsigned int irq)
127{
128 struct irq_desc *desc = irq_to_desc(irq);
129
130 if (desc) {
131 __synchronize_hardirq(desc, true);
132 /*
133 * We made sure that no hardirq handler is
134 * running. Now verify that no threaded handlers are
135 * active.
136 */
137 wait_event(desc->wait_for_threads,
138 !atomic_read(&desc->threads_active));
139 }
140}
141EXPORT_SYMBOL(synchronize_irq);
142
143#ifdef CONFIG_SMP
144cpumask_var_t irq_default_affinity;
145
146static bool __irq_can_set_affinity(struct irq_desc *desc)
147{
148 if (!desc || !irqd_can_balance(&desc->irq_data) ||
149 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
150 return false;
151 return true;
152}
153
154/**
155 * irq_can_set_affinity - Check if the affinity of a given irq can be set
156 * @irq: Interrupt to check
157 *
158 */
159int irq_can_set_affinity(unsigned int irq)
160{
161 return __irq_can_set_affinity(irq_to_desc(irq));
162}
163
164/**
165 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
166 * @irq: Interrupt to check
167 *
168 * Like irq_can_set_affinity() above, but additionally checks for the
169 * AFFINITY_MANAGED flag.
170 */
171bool irq_can_set_affinity_usr(unsigned int irq)
172{
173 struct irq_desc *desc = irq_to_desc(irq);
174
175 return __irq_can_set_affinity(desc) &&
176 !irqd_affinity_is_managed(&desc->irq_data);
177}
178
179/**
180 * irq_set_thread_affinity - Notify irq threads to adjust affinity
181 * @desc: irq descriptor which has affinity changed
182 *
183 * We just set IRQTF_AFFINITY and delegate the affinity setting
184 * to the interrupt thread itself. We can not call
185 * set_cpus_allowed_ptr() here as we hold desc->lock and this
186 * code can be called from hard interrupt context.
187 */
188void irq_set_thread_affinity(struct irq_desc *desc)
189{
190 struct irqaction *action;
191
192 for_each_action_of_desc(desc, action)
193 if (action->thread)
194 set_bit(IRQTF_AFFINITY, &action->thread_flags);
195}
196
197#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
198static void irq_validate_effective_affinity(struct irq_data *data)
199{
200 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
201 struct irq_chip *chip = irq_data_get_irq_chip(data);
202
203 if (!cpumask_empty(m))
204 return;
205 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
206 chip->name, data->irq);
207}
208#else
209static inline void irq_validate_effective_affinity(struct irq_data *data) { }
210#endif
211
212int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
213 bool force)
214{
215 struct irq_desc *desc = irq_data_to_desc(data);
216 struct irq_chip *chip = irq_data_get_irq_chip(data);
217 const struct cpumask *prog_mask;
218 int ret;
219
220 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
221 static struct cpumask tmp_mask;
222
223 if (!chip || !chip->irq_set_affinity)
224 return -EINVAL;
225
226 raw_spin_lock(&tmp_mask_lock);
227 /*
228 * If this is a managed interrupt and housekeeping is enabled on
229 * it check whether the requested affinity mask intersects with
230 * a housekeeping CPU. If so, then remove the isolated CPUs from
231 * the mask and just keep the housekeeping CPU(s). This prevents
232 * the affinity setter from routing the interrupt to an isolated
233 * CPU to avoid that I/O submitted from a housekeeping CPU causes
234 * interrupts on an isolated one.
235 *
236 * If the masks do not intersect or include online CPU(s) then
237 * keep the requested mask. The isolated target CPUs are only
238 * receiving interrupts when the I/O operation was submitted
239 * directly from them.
240 *
241 * If all housekeeping CPUs in the affinity mask are offline, the
242 * interrupt will be migrated by the CPU hotplug code once a
243 * housekeeping CPU which belongs to the affinity mask comes
244 * online.
245 */
246 if (irqd_affinity_is_managed(data) &&
247 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
248 const struct cpumask *hk_mask;
249
250 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
251
252 cpumask_and(&tmp_mask, mask, hk_mask);
253 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
254 prog_mask = mask;
255 else
256 prog_mask = &tmp_mask;
257 } else {
258 prog_mask = mask;
259 }
260
261 /*
262 * Make sure we only provide online CPUs to the irqchip,
263 * unless we are being asked to force the affinity (in which
264 * case we do as we are told).
265 */
266 cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
267 if (!force && !cpumask_empty(&tmp_mask))
268 ret = chip->irq_set_affinity(data, &tmp_mask, force);
269 else if (force)
270 ret = chip->irq_set_affinity(data, mask, force);
271 else
272 ret = -EINVAL;
273
274 raw_spin_unlock(&tmp_mask_lock);
275
276 switch (ret) {
277 case IRQ_SET_MASK_OK:
278 case IRQ_SET_MASK_OK_DONE:
279 cpumask_copy(desc->irq_common_data.affinity, mask);
280 fallthrough;
281 case IRQ_SET_MASK_OK_NOCOPY:
282 irq_validate_effective_affinity(data);
283 irq_set_thread_affinity(desc);
284 ret = 0;
285 }
286
287 return ret;
288}
289
290#ifdef CONFIG_GENERIC_PENDING_IRQ
291static inline int irq_set_affinity_pending(struct irq_data *data,
292 const struct cpumask *dest)
293{
294 struct irq_desc *desc = irq_data_to_desc(data);
295
296 irqd_set_move_pending(data);
297 irq_copy_pending(desc, dest);
298 return 0;
299}
300#else
301static inline int irq_set_affinity_pending(struct irq_data *data,
302 const struct cpumask *dest)
303{
304 return -EBUSY;
305}
306#endif
307
308static int irq_try_set_affinity(struct irq_data *data,
309 const struct cpumask *dest, bool force)
310{
311 int ret = irq_do_set_affinity(data, dest, force);
312
313 /*
314 * In case that the underlying vector management is busy and the
315 * architecture supports the generic pending mechanism then utilize
316 * this to avoid returning an error to user space.
317 */
318 if (ret == -EBUSY && !force)
319 ret = irq_set_affinity_pending(data, dest);
320 return ret;
321}
322
323static bool irq_set_affinity_deactivated(struct irq_data *data,
324 const struct cpumask *mask)
325{
326 struct irq_desc *desc = irq_data_to_desc(data);
327
328 /*
329 * Handle irq chips which can handle affinity only in activated
330 * state correctly
331 *
332 * If the interrupt is not yet activated, just store the affinity
333 * mask and do not call the chip driver at all. On activation the
334 * driver has to make sure anyway that the interrupt is in a
335 * usable state so startup works.
336 */
337 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
338 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
339 return false;
340
341 cpumask_copy(desc->irq_common_data.affinity, mask);
342 irq_data_update_effective_affinity(data, mask);
343 irqd_set(data, IRQD_AFFINITY_SET);
344 return true;
345}
346
347int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
348 bool force)
349{
350 struct irq_chip *chip = irq_data_get_irq_chip(data);
351 struct irq_desc *desc = irq_data_to_desc(data);
352 int ret = 0;
353
354 if (!chip || !chip->irq_set_affinity)
355 return -EINVAL;
356
357 if (irq_set_affinity_deactivated(data, mask))
358 return 0;
359
360 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
361 ret = irq_try_set_affinity(data, mask, force);
362 } else {
363 irqd_set_move_pending(data);
364 irq_copy_pending(desc, mask);
365 }
366
367 if (desc->affinity_notify) {
368 kref_get(&desc->affinity_notify->kref);
369 if (!schedule_work(&desc->affinity_notify->work)) {
370 /* Work was already scheduled, drop our extra ref */
371 kref_put(&desc->affinity_notify->kref,
372 desc->affinity_notify->release);
373 }
374 }
375 irqd_set(data, IRQD_AFFINITY_SET);
376
377 return ret;
378}
379
380/**
381 * irq_update_affinity_desc - Update affinity management for an interrupt
382 * @irq: The interrupt number to update
383 * @affinity: Pointer to the affinity descriptor
384 *
385 * This interface can be used to configure the affinity management of
386 * interrupts which have been allocated already.
387 *
388 * There are certain limitations on when it may be used - attempts to use it
389 * for when the kernel is configured for generic IRQ reservation mode (in
390 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
391 * managed/non-managed interrupt accounting. In addition, attempts to use it on
392 * an interrupt which is already started or which has already been configured
393 * as managed will also fail, as these mean invalid init state or double init.
394 */
395int irq_update_affinity_desc(unsigned int irq,
396 struct irq_affinity_desc *affinity)
397{
398 struct irq_desc *desc;
399 unsigned long flags;
400 bool activated;
401 int ret = 0;
402
403 /*
404 * Supporting this with the reservation scheme used by x86 needs
405 * some more thought. Fail it for now.
406 */
407 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
408 return -EOPNOTSUPP;
409
410 desc = irq_get_desc_buslock(irq, &flags, 0);
411 if (!desc)
412 return -EINVAL;
413
414 /* Requires the interrupt to be shut down */
415 if (irqd_is_started(&desc->irq_data)) {
416 ret = -EBUSY;
417 goto out_unlock;
418 }
419
420 /* Interrupts which are already managed cannot be modified */
421 if (irqd_affinity_is_managed(&desc->irq_data)) {
422 ret = -EBUSY;
423 goto out_unlock;
424 }
425
426 /*
427 * Deactivate the interrupt. That's required to undo
428 * anything an earlier activation has established.
429 */
430 activated = irqd_is_activated(&desc->irq_data);
431 if (activated)
432 irq_domain_deactivate_irq(&desc->irq_data);
433
434 if (affinity->is_managed) {
435 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
436 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
437 }
438
439 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
440
441 /* Restore the activation state */
442 if (activated)
443 irq_domain_activate_irq(&desc->irq_data, false);
444
445out_unlock:
446 irq_put_desc_busunlock(desc, flags);
447 return ret;
448}
449
450static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
451 bool force)
452{
453 struct irq_desc *desc = irq_to_desc(irq);
454 unsigned long flags;
455 int ret;
456
457 if (!desc)
458 return -EINVAL;
459
460 raw_spin_lock_irqsave(&desc->lock, flags);
461 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
462 raw_spin_unlock_irqrestore(&desc->lock, flags);
463 return ret;
464}
465
466/**
467 * irq_set_affinity - Set the irq affinity of a given irq
468 * @irq: Interrupt to set affinity
469 * @cpumask: cpumask
470 *
471 * Fails if cpumask does not contain an online CPU
472 */
473int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
474{
475 return __irq_set_affinity(irq, cpumask, false);
476}
477EXPORT_SYMBOL_GPL(irq_set_affinity);
478
479/**
480 * irq_force_affinity - Force the irq affinity of a given irq
481 * @irq: Interrupt to set affinity
482 * @cpumask: cpumask
483 *
484 * Same as irq_set_affinity, but without checking the mask against
485 * online cpus.
486 *
487 * Solely for low level cpu hotplug code, where we need to make per
488 * cpu interrupts affine before the cpu becomes online.
489 */
490int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
491{
492 return __irq_set_affinity(irq, cpumask, true);
493}
494EXPORT_SYMBOL_GPL(irq_force_affinity);
495
496int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
497 bool setaffinity)
498{
499 unsigned long flags;
500 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
501
502 if (!desc)
503 return -EINVAL;
504 desc->affinity_hint = m;
505 irq_put_desc_unlock(desc, flags);
506 if (m && setaffinity)
507 __irq_set_affinity(irq, m, false);
508 return 0;
509}
510EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
511
512static void irq_affinity_notify(struct work_struct *work)
513{
514 struct irq_affinity_notify *notify =
515 container_of(work, struct irq_affinity_notify, work);
516 struct irq_desc *desc = irq_to_desc(notify->irq);
517 cpumask_var_t cpumask;
518 unsigned long flags;
519
520 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
521 goto out;
522
523 raw_spin_lock_irqsave(&desc->lock, flags);
524 if (irq_move_pending(&desc->irq_data))
525 irq_get_pending(cpumask, desc);
526 else
527 cpumask_copy(cpumask, desc->irq_common_data.affinity);
528 raw_spin_unlock_irqrestore(&desc->lock, flags);
529
530 notify->notify(notify, cpumask);
531
532 free_cpumask_var(cpumask);
533out:
534 kref_put(¬ify->kref, notify->release);
535}
536
537/**
538 * irq_set_affinity_notifier - control notification of IRQ affinity changes
539 * @irq: Interrupt for which to enable/disable notification
540 * @notify: Context for notification, or %NULL to disable
541 * notification. Function pointers must be initialised;
542 * the other fields will be initialised by this function.
543 *
544 * Must be called in process context. Notification may only be enabled
545 * after the IRQ is allocated and must be disabled before the IRQ is
546 * freed using free_irq().
547 */
548int
549irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
550{
551 struct irq_desc *desc = irq_to_desc(irq);
552 struct irq_affinity_notify *old_notify;
553 unsigned long flags;
554
555 /* The release function is promised process context */
556 might_sleep();
557
558 if (!desc || desc->istate & IRQS_NMI)
559 return -EINVAL;
560
561 /* Complete initialisation of *notify */
562 if (notify) {
563 notify->irq = irq;
564 kref_init(¬ify->kref);
565 INIT_WORK(¬ify->work, irq_affinity_notify);
566 }
567
568 raw_spin_lock_irqsave(&desc->lock, flags);
569 old_notify = desc->affinity_notify;
570 desc->affinity_notify = notify;
571 raw_spin_unlock_irqrestore(&desc->lock, flags);
572
573 if (old_notify) {
574 if (cancel_work_sync(&old_notify->work)) {
575 /* Pending work had a ref, put that one too */
576 kref_put(&old_notify->kref, old_notify->release);
577 }
578 kref_put(&old_notify->kref, old_notify->release);
579 }
580
581 return 0;
582}
583EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
584
585#ifndef CONFIG_AUTO_IRQ_AFFINITY
586/*
587 * Generic version of the affinity autoselector.
588 */
589int irq_setup_affinity(struct irq_desc *desc)
590{
591 struct cpumask *set = irq_default_affinity;
592 int ret, node = irq_desc_get_node(desc);
593 static DEFINE_RAW_SPINLOCK(mask_lock);
594 static struct cpumask mask;
595
596 /* Excludes PER_CPU and NO_BALANCE interrupts */
597 if (!__irq_can_set_affinity(desc))
598 return 0;
599
600 raw_spin_lock(&mask_lock);
601 /*
602 * Preserve the managed affinity setting and a userspace affinity
603 * setup, but make sure that one of the targets is online.
604 */
605 if (irqd_affinity_is_managed(&desc->irq_data) ||
606 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
607 if (cpumask_intersects(desc->irq_common_data.affinity,
608 cpu_online_mask))
609 set = desc->irq_common_data.affinity;
610 else
611 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
612 }
613
614 cpumask_and(&mask, cpu_online_mask, set);
615 if (cpumask_empty(&mask))
616 cpumask_copy(&mask, cpu_online_mask);
617
618 if (node != NUMA_NO_NODE) {
619 const struct cpumask *nodemask = cpumask_of_node(node);
620
621 /* make sure at least one of the cpus in nodemask is online */
622 if (cpumask_intersects(&mask, nodemask))
623 cpumask_and(&mask, &mask, nodemask);
624 }
625 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
626 raw_spin_unlock(&mask_lock);
627 return ret;
628}
629#else
630/* Wrapper for ALPHA specific affinity selector magic */
631int irq_setup_affinity(struct irq_desc *desc)
632{
633 return irq_select_affinity(irq_desc_get_irq(desc));
634}
635#endif /* CONFIG_AUTO_IRQ_AFFINITY */
636#endif /* CONFIG_SMP */
637
638
639/**
640 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
641 * @irq: interrupt number to set affinity
642 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
643 * specific data for percpu_devid interrupts
644 *
645 * This function uses the vCPU specific data to set the vCPU
646 * affinity for an irq. The vCPU specific data is passed from
647 * outside, such as KVM. One example code path is as below:
648 * KVM -> IOMMU -> irq_set_vcpu_affinity().
649 */
650int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
651{
652 unsigned long flags;
653 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
654 struct irq_data *data;
655 struct irq_chip *chip;
656 int ret = -ENOSYS;
657
658 if (!desc)
659 return -EINVAL;
660
661 data = irq_desc_get_irq_data(desc);
662 do {
663 chip = irq_data_get_irq_chip(data);
664 if (chip && chip->irq_set_vcpu_affinity)
665 break;
666#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
667 data = data->parent_data;
668#else
669 data = NULL;
670#endif
671 } while (data);
672
673 if (data)
674 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
675 irq_put_desc_unlock(desc, flags);
676
677 return ret;
678}
679EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
680
681void __disable_irq(struct irq_desc *desc)
682{
683 if (!desc->depth++)
684 irq_disable(desc);
685}
686
687static int __disable_irq_nosync(unsigned int irq)
688{
689 unsigned long flags;
690 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
691
692 if (!desc)
693 return -EINVAL;
694 __disable_irq(desc);
695 irq_put_desc_busunlock(desc, flags);
696 return 0;
697}
698
699/**
700 * disable_irq_nosync - disable an irq without waiting
701 * @irq: Interrupt to disable
702 *
703 * Disable the selected interrupt line. Disables and Enables are
704 * nested.
705 * Unlike disable_irq(), this function does not ensure existing
706 * instances of the IRQ handler have completed before returning.
707 *
708 * This function may be called from IRQ context.
709 */
710void disable_irq_nosync(unsigned int irq)
711{
712 __disable_irq_nosync(irq);
713}
714EXPORT_SYMBOL(disable_irq_nosync);
715
716/**
717 * disable_irq - disable an irq and wait for completion
718 * @irq: Interrupt to disable
719 *
720 * Disable the selected interrupt line. Enables and Disables are
721 * nested.
722 * This function waits for any pending IRQ handlers for this interrupt
723 * to complete before returning. If you use this function while
724 * holding a resource the IRQ handler may need you will deadlock.
725 *
726 * This function may be called - with care - from IRQ context.
727 */
728void disable_irq(unsigned int irq)
729{
730 if (!__disable_irq_nosync(irq))
731 synchronize_irq(irq);
732}
733EXPORT_SYMBOL(disable_irq);
734
735/**
736 * disable_hardirq - disables an irq and waits for hardirq completion
737 * @irq: Interrupt to disable
738 *
739 * Disable the selected interrupt line. Enables and Disables are
740 * nested.
741 * This function waits for any pending hard IRQ handlers for this
742 * interrupt to complete before returning. If you use this function while
743 * holding a resource the hard IRQ handler may need you will deadlock.
744 *
745 * When used to optimistically disable an interrupt from atomic context
746 * the return value must be checked.
747 *
748 * Returns: false if a threaded handler is active.
749 *
750 * This function may be called - with care - from IRQ context.
751 */
752bool disable_hardirq(unsigned int irq)
753{
754 if (!__disable_irq_nosync(irq))
755 return synchronize_hardirq(irq);
756
757 return false;
758}
759EXPORT_SYMBOL_GPL(disable_hardirq);
760
761/**
762 * disable_nmi_nosync - disable an nmi without waiting
763 * @irq: Interrupt to disable
764 *
765 * Disable the selected interrupt line. Disables and enables are
766 * nested.
767 * The interrupt to disable must have been requested through request_nmi.
768 * Unlike disable_nmi(), this function does not ensure existing
769 * instances of the IRQ handler have completed before returning.
770 */
771void disable_nmi_nosync(unsigned int irq)
772{
773 disable_irq_nosync(irq);
774}
775
776void __enable_irq(struct irq_desc *desc)
777{
778 switch (desc->depth) {
779 case 0:
780 err_out:
781 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
782 irq_desc_get_irq(desc));
783 break;
784 case 1: {
785 if (desc->istate & IRQS_SUSPENDED)
786 goto err_out;
787 /* Prevent probing on this irq: */
788 irq_settings_set_noprobe(desc);
789 /*
790 * Call irq_startup() not irq_enable() here because the
791 * interrupt might be marked NOAUTOEN. So irq_startup()
792 * needs to be invoked when it gets enabled the first
793 * time. If it was already started up, then irq_startup()
794 * will invoke irq_enable() under the hood.
795 */
796 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
797 break;
798 }
799 default:
800 desc->depth--;
801 }
802}
803
804/**
805 * enable_irq - enable handling of an irq
806 * @irq: Interrupt to enable
807 *
808 * Undoes the effect of one call to disable_irq(). If this
809 * matches the last disable, processing of interrupts on this
810 * IRQ line is re-enabled.
811 *
812 * This function may be called from IRQ context only when
813 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
814 */
815void enable_irq(unsigned int irq)
816{
817 unsigned long flags;
818 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
819
820 if (!desc)
821 return;
822 if (WARN(!desc->irq_data.chip,
823 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
824 goto out;
825
826 __enable_irq(desc);
827out:
828 irq_put_desc_busunlock(desc, flags);
829}
830EXPORT_SYMBOL(enable_irq);
831
832/**
833 * enable_nmi - enable handling of an nmi
834 * @irq: Interrupt to enable
835 *
836 * The interrupt to enable must have been requested through request_nmi.
837 * Undoes the effect of one call to disable_nmi(). If this
838 * matches the last disable, processing of interrupts on this
839 * IRQ line is re-enabled.
840 */
841void enable_nmi(unsigned int irq)
842{
843 enable_irq(irq);
844}
845
846static int set_irq_wake_real(unsigned int irq, unsigned int on)
847{
848 struct irq_desc *desc = irq_to_desc(irq);
849 int ret = -ENXIO;
850
851 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
852 return 0;
853
854 if (desc->irq_data.chip->irq_set_wake)
855 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
856
857 return ret;
858}
859
860/**
861 * irq_set_irq_wake - control irq power management wakeup
862 * @irq: interrupt to control
863 * @on: enable/disable power management wakeup
864 *
865 * Enable/disable power management wakeup mode, which is
866 * disabled by default. Enables and disables must match,
867 * just as they match for non-wakeup mode support.
868 *
869 * Wakeup mode lets this IRQ wake the system from sleep
870 * states like "suspend to RAM".
871 *
872 * Note: irq enable/disable state is completely orthogonal
873 * to the enable/disable state of irq wake. An irq can be
874 * disabled with disable_irq() and still wake the system as
875 * long as the irq has wake enabled. If this does not hold,
876 * then the underlying irq chip and the related driver need
877 * to be investigated.
878 */
879int irq_set_irq_wake(unsigned int irq, unsigned int on)
880{
881 unsigned long flags;
882 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
883 int ret = 0;
884
885 if (!desc)
886 return -EINVAL;
887
888 /* Don't use NMIs as wake up interrupts please */
889 if (desc->istate & IRQS_NMI) {
890 ret = -EINVAL;
891 goto out_unlock;
892 }
893
894 /* wakeup-capable irqs can be shared between drivers that
895 * don't need to have the same sleep mode behaviors.
896 */
897 if (on) {
898 if (desc->wake_depth++ == 0) {
899 ret = set_irq_wake_real(irq, on);
900 if (ret)
901 desc->wake_depth = 0;
902 else
903 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
904 }
905 } else {
906 if (desc->wake_depth == 0) {
907 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
908 } else if (--desc->wake_depth == 0) {
909 ret = set_irq_wake_real(irq, on);
910 if (ret)
911 desc->wake_depth = 1;
912 else
913 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
914 }
915 }
916
917out_unlock:
918 irq_put_desc_busunlock(desc, flags);
919 return ret;
920}
921EXPORT_SYMBOL(irq_set_irq_wake);
922
923/*
924 * Internal function that tells the architecture code whether a
925 * particular irq has been exclusively allocated or is available
926 * for driver use.
927 */
928int can_request_irq(unsigned int irq, unsigned long irqflags)
929{
930 unsigned long flags;
931 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
932 int canrequest = 0;
933
934 if (!desc)
935 return 0;
936
937 if (irq_settings_can_request(desc)) {
938 if (!desc->action ||
939 irqflags & desc->action->flags & IRQF_SHARED)
940 canrequest = 1;
941 }
942 irq_put_desc_unlock(desc, flags);
943 return canrequest;
944}
945
946int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
947{
948 struct irq_chip *chip = desc->irq_data.chip;
949 int ret, unmask = 0;
950
951 if (!chip || !chip->irq_set_type) {
952 /*
953 * IRQF_TRIGGER_* but the PIC does not support multiple
954 * flow-types?
955 */
956 pr_debug("No set_type function for IRQ %d (%s)\n",
957 irq_desc_get_irq(desc),
958 chip ? (chip->name ? : "unknown") : "unknown");
959 return 0;
960 }
961
962 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
963 if (!irqd_irq_masked(&desc->irq_data))
964 mask_irq(desc);
965 if (!irqd_irq_disabled(&desc->irq_data))
966 unmask = 1;
967 }
968
969 /* Mask all flags except trigger mode */
970 flags &= IRQ_TYPE_SENSE_MASK;
971 ret = chip->irq_set_type(&desc->irq_data, flags);
972
973 switch (ret) {
974 case IRQ_SET_MASK_OK:
975 case IRQ_SET_MASK_OK_DONE:
976 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
977 irqd_set(&desc->irq_data, flags);
978 fallthrough;
979
980 case IRQ_SET_MASK_OK_NOCOPY:
981 flags = irqd_get_trigger_type(&desc->irq_data);
982 irq_settings_set_trigger_mask(desc, flags);
983 irqd_clear(&desc->irq_data, IRQD_LEVEL);
984 irq_settings_clr_level(desc);
985 if (flags & IRQ_TYPE_LEVEL_MASK) {
986 irq_settings_set_level(desc);
987 irqd_set(&desc->irq_data, IRQD_LEVEL);
988 }
989
990 ret = 0;
991 break;
992 default:
993 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
994 flags, irq_desc_get_irq(desc), chip->irq_set_type);
995 }
996 if (unmask)
997 unmask_irq(desc);
998 return ret;
999}
1000
1001#ifdef CONFIG_HARDIRQS_SW_RESEND
1002int irq_set_parent(int irq, int parent_irq)
1003{
1004 unsigned long flags;
1005 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1006
1007 if (!desc)
1008 return -EINVAL;
1009
1010 desc->parent_irq = parent_irq;
1011
1012 irq_put_desc_unlock(desc, flags);
1013 return 0;
1014}
1015EXPORT_SYMBOL_GPL(irq_set_parent);
1016#endif
1017
1018/*
1019 * Default primary interrupt handler for threaded interrupts. Is
1020 * assigned as primary handler when request_threaded_irq is called
1021 * with handler == NULL. Useful for oneshot interrupts.
1022 */
1023static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1024{
1025 return IRQ_WAKE_THREAD;
1026}
1027
1028/*
1029 * Primary handler for nested threaded interrupts. Should never be
1030 * called.
1031 */
1032static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1033{
1034 WARN(1, "Primary handler called for nested irq %d\n", irq);
1035 return IRQ_NONE;
1036}
1037
1038static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1039{
1040 WARN(1, "Secondary action handler called for irq %d\n", irq);
1041 return IRQ_NONE;
1042}
1043
1044static int irq_wait_for_interrupt(struct irqaction *action)
1045{
1046 for (;;) {
1047 set_current_state(TASK_INTERRUPTIBLE);
1048
1049 if (kthread_should_stop()) {
1050 /* may need to run one last time */
1051 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1052 &action->thread_flags)) {
1053 __set_current_state(TASK_RUNNING);
1054 return 0;
1055 }
1056 __set_current_state(TASK_RUNNING);
1057 return -1;
1058 }
1059
1060 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1061 &action->thread_flags)) {
1062 __set_current_state(TASK_RUNNING);
1063 return 0;
1064 }
1065 schedule();
1066 }
1067}
1068
1069/*
1070 * Oneshot interrupts keep the irq line masked until the threaded
1071 * handler finished. unmask if the interrupt has not been disabled and
1072 * is marked MASKED.
1073 */
1074static void irq_finalize_oneshot(struct irq_desc *desc,
1075 struct irqaction *action)
1076{
1077 if (!(desc->istate & IRQS_ONESHOT) ||
1078 action->handler == irq_forced_secondary_handler)
1079 return;
1080again:
1081 chip_bus_lock(desc);
1082 raw_spin_lock_irq(&desc->lock);
1083
1084 /*
1085 * Implausible though it may be we need to protect us against
1086 * the following scenario:
1087 *
1088 * The thread is faster done than the hard interrupt handler
1089 * on the other CPU. If we unmask the irq line then the
1090 * interrupt can come in again and masks the line, leaves due
1091 * to IRQS_INPROGRESS and the irq line is masked forever.
1092 *
1093 * This also serializes the state of shared oneshot handlers
1094 * versus "desc->threads_oneshot |= action->thread_mask;" in
1095 * irq_wake_thread(). See the comment there which explains the
1096 * serialization.
1097 */
1098 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1099 raw_spin_unlock_irq(&desc->lock);
1100 chip_bus_sync_unlock(desc);
1101 cpu_relax();
1102 goto again;
1103 }
1104
1105 /*
1106 * Now check again, whether the thread should run. Otherwise
1107 * we would clear the threads_oneshot bit of this thread which
1108 * was just set.
1109 */
1110 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1111 goto out_unlock;
1112
1113 desc->threads_oneshot &= ~action->thread_mask;
1114
1115 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1116 irqd_irq_masked(&desc->irq_data))
1117 unmask_threaded_irq(desc);
1118
1119out_unlock:
1120 raw_spin_unlock_irq(&desc->lock);
1121 chip_bus_sync_unlock(desc);
1122}
1123
1124#ifdef CONFIG_SMP
1125/*
1126 * Check whether we need to change the affinity of the interrupt thread.
1127 */
1128static void
1129irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1130{
1131 cpumask_var_t mask;
1132 bool valid = true;
1133
1134 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1135 return;
1136
1137 /*
1138 * In case we are out of memory we set IRQTF_AFFINITY again and
1139 * try again next time
1140 */
1141 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1142 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1143 return;
1144 }
1145
1146 raw_spin_lock_irq(&desc->lock);
1147 /*
1148 * This code is triggered unconditionally. Check the affinity
1149 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1150 */
1151 if (cpumask_available(desc->irq_common_data.affinity)) {
1152 const struct cpumask *m;
1153
1154 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1155 cpumask_copy(mask, m);
1156 } else {
1157 valid = false;
1158 }
1159 raw_spin_unlock_irq(&desc->lock);
1160
1161 if (valid)
1162 set_cpus_allowed_ptr(current, mask);
1163 free_cpumask_var(mask);
1164}
1165#else
1166static inline void
1167irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1168#endif
1169
1170/*
1171 * Interrupts which are not explicitly requested as threaded
1172 * interrupts rely on the implicit bh/preempt disable of the hard irq
1173 * context. So we need to disable bh here to avoid deadlocks and other
1174 * side effects.
1175 */
1176static irqreturn_t
1177irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1178{
1179 irqreturn_t ret;
1180
1181 local_bh_disable();
1182 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1183 local_irq_disable();
1184 ret = action->thread_fn(action->irq, action->dev_id);
1185 if (ret == IRQ_HANDLED)
1186 atomic_inc(&desc->threads_handled);
1187
1188 irq_finalize_oneshot(desc, action);
1189 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1190 local_irq_enable();
1191 local_bh_enable();
1192 return ret;
1193}
1194
1195/*
1196 * Interrupts explicitly requested as threaded interrupts want to be
1197 * preemptible - many of them need to sleep and wait for slow busses to
1198 * complete.
1199 */
1200static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1201 struct irqaction *action)
1202{
1203 irqreturn_t ret;
1204
1205 ret = action->thread_fn(action->irq, action->dev_id);
1206 if (ret == IRQ_HANDLED)
1207 atomic_inc(&desc->threads_handled);
1208
1209 irq_finalize_oneshot(desc, action);
1210 return ret;
1211}
1212
1213static void wake_threads_waitq(struct irq_desc *desc)
1214{
1215 if (atomic_dec_and_test(&desc->threads_active))
1216 wake_up(&desc->wait_for_threads);
1217}
1218
1219static void irq_thread_dtor(struct callback_head *unused)
1220{
1221 struct task_struct *tsk = current;
1222 struct irq_desc *desc;
1223 struct irqaction *action;
1224
1225 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1226 return;
1227
1228 action = kthread_data(tsk);
1229
1230 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1231 tsk->comm, tsk->pid, action->irq);
1232
1233
1234 desc = irq_to_desc(action->irq);
1235 /*
1236 * If IRQTF_RUNTHREAD is set, we need to decrement
1237 * desc->threads_active and wake possible waiters.
1238 */
1239 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1240 wake_threads_waitq(desc);
1241
1242 /* Prevent a stale desc->threads_oneshot */
1243 irq_finalize_oneshot(desc, action);
1244}
1245
1246static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1247{
1248 struct irqaction *secondary = action->secondary;
1249
1250 if (WARN_ON_ONCE(!secondary))
1251 return;
1252
1253 raw_spin_lock_irq(&desc->lock);
1254 __irq_wake_thread(desc, secondary);
1255 raw_spin_unlock_irq(&desc->lock);
1256}
1257
1258/*
1259 * Internal function to notify that a interrupt thread is ready.
1260 */
1261static void irq_thread_set_ready(struct irq_desc *desc,
1262 struct irqaction *action)
1263{
1264 set_bit(IRQTF_READY, &action->thread_flags);
1265 wake_up(&desc->wait_for_threads);
1266}
1267
1268/*
1269 * Internal function to wake up a interrupt thread and wait until it is
1270 * ready.
1271 */
1272static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1273 struct irqaction *action)
1274{
1275 if (!action || !action->thread)
1276 return;
1277
1278 wake_up_process(action->thread);
1279 wait_event(desc->wait_for_threads,
1280 test_bit(IRQTF_READY, &action->thread_flags));
1281}
1282
1283/*
1284 * Interrupt handler thread
1285 */
1286static int irq_thread(void *data)
1287{
1288 struct callback_head on_exit_work;
1289 struct irqaction *action = data;
1290 struct irq_desc *desc = irq_to_desc(action->irq);
1291 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1292 struct irqaction *action);
1293
1294 irq_thread_set_ready(desc, action);
1295
1296 sched_set_fifo(current);
1297
1298 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1299 &action->thread_flags))
1300 handler_fn = irq_forced_thread_fn;
1301 else
1302 handler_fn = irq_thread_fn;
1303
1304 init_task_work(&on_exit_work, irq_thread_dtor);
1305 task_work_add(current, &on_exit_work, TWA_NONE);
1306
1307 irq_thread_check_affinity(desc, action);
1308
1309 while (!irq_wait_for_interrupt(action)) {
1310 irqreturn_t action_ret;
1311
1312 irq_thread_check_affinity(desc, action);
1313
1314 action_ret = handler_fn(desc, action);
1315 if (action_ret == IRQ_WAKE_THREAD)
1316 irq_wake_secondary(desc, action);
1317
1318 wake_threads_waitq(desc);
1319 }
1320
1321 /*
1322 * This is the regular exit path. __free_irq() is stopping the
1323 * thread via kthread_stop() after calling
1324 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1325 * oneshot mask bit can be set.
1326 */
1327 task_work_cancel(current, irq_thread_dtor);
1328 return 0;
1329}
1330
1331/**
1332 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1333 * @irq: Interrupt line
1334 * @dev_id: Device identity for which the thread should be woken
1335 *
1336 */
1337void irq_wake_thread(unsigned int irq, void *dev_id)
1338{
1339 struct irq_desc *desc = irq_to_desc(irq);
1340 struct irqaction *action;
1341 unsigned long flags;
1342
1343 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1344 return;
1345
1346 raw_spin_lock_irqsave(&desc->lock, flags);
1347 for_each_action_of_desc(desc, action) {
1348 if (action->dev_id == dev_id) {
1349 if (action->thread)
1350 __irq_wake_thread(desc, action);
1351 break;
1352 }
1353 }
1354 raw_spin_unlock_irqrestore(&desc->lock, flags);
1355}
1356EXPORT_SYMBOL_GPL(irq_wake_thread);
1357
1358static int irq_setup_forced_threading(struct irqaction *new)
1359{
1360 if (!force_irqthreads())
1361 return 0;
1362 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1363 return 0;
1364
1365 /*
1366 * No further action required for interrupts which are requested as
1367 * threaded interrupts already
1368 */
1369 if (new->handler == irq_default_primary_handler)
1370 return 0;
1371
1372 new->flags |= IRQF_ONESHOT;
1373
1374 /*
1375 * Handle the case where we have a real primary handler and a
1376 * thread handler. We force thread them as well by creating a
1377 * secondary action.
1378 */
1379 if (new->handler && new->thread_fn) {
1380 /* Allocate the secondary action */
1381 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1382 if (!new->secondary)
1383 return -ENOMEM;
1384 new->secondary->handler = irq_forced_secondary_handler;
1385 new->secondary->thread_fn = new->thread_fn;
1386 new->secondary->dev_id = new->dev_id;
1387 new->secondary->irq = new->irq;
1388 new->secondary->name = new->name;
1389 }
1390 /* Deal with the primary handler */
1391 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1392 new->thread_fn = new->handler;
1393 new->handler = irq_default_primary_handler;
1394 return 0;
1395}
1396
1397static int irq_request_resources(struct irq_desc *desc)
1398{
1399 struct irq_data *d = &desc->irq_data;
1400 struct irq_chip *c = d->chip;
1401
1402 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1403}
1404
1405static void irq_release_resources(struct irq_desc *desc)
1406{
1407 struct irq_data *d = &desc->irq_data;
1408 struct irq_chip *c = d->chip;
1409
1410 if (c->irq_release_resources)
1411 c->irq_release_resources(d);
1412}
1413
1414static bool irq_supports_nmi(struct irq_desc *desc)
1415{
1416 struct irq_data *d = irq_desc_get_irq_data(desc);
1417
1418#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1419 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1420 if (d->parent_data)
1421 return false;
1422#endif
1423 /* Don't support NMIs for chips behind a slow bus */
1424 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1425 return false;
1426
1427 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1428}
1429
1430static int irq_nmi_setup(struct irq_desc *desc)
1431{
1432 struct irq_data *d = irq_desc_get_irq_data(desc);
1433 struct irq_chip *c = d->chip;
1434
1435 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1436}
1437
1438static void irq_nmi_teardown(struct irq_desc *desc)
1439{
1440 struct irq_data *d = irq_desc_get_irq_data(desc);
1441 struct irq_chip *c = d->chip;
1442
1443 if (c->irq_nmi_teardown)
1444 c->irq_nmi_teardown(d);
1445}
1446
1447static int
1448setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1449{
1450 struct task_struct *t;
1451
1452 if (!secondary) {
1453 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1454 new->name);
1455 } else {
1456 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1457 new->name);
1458 }
1459
1460 if (IS_ERR(t))
1461 return PTR_ERR(t);
1462
1463 /*
1464 * We keep the reference to the task struct even if
1465 * the thread dies to avoid that the interrupt code
1466 * references an already freed task_struct.
1467 */
1468 new->thread = get_task_struct(t);
1469 /*
1470 * Tell the thread to set its affinity. This is
1471 * important for shared interrupt handlers as we do
1472 * not invoke setup_affinity() for the secondary
1473 * handlers as everything is already set up. Even for
1474 * interrupts marked with IRQF_NO_BALANCE this is
1475 * correct as we want the thread to move to the cpu(s)
1476 * on which the requesting code placed the interrupt.
1477 */
1478 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1479 return 0;
1480}
1481
1482/*
1483 * Internal function to register an irqaction - typically used to
1484 * allocate special interrupts that are part of the architecture.
1485 *
1486 * Locking rules:
1487 *
1488 * desc->request_mutex Provides serialization against a concurrent free_irq()
1489 * chip_bus_lock Provides serialization for slow bus operations
1490 * desc->lock Provides serialization against hard interrupts
1491 *
1492 * chip_bus_lock and desc->lock are sufficient for all other management and
1493 * interrupt related functions. desc->request_mutex solely serializes
1494 * request/free_irq().
1495 */
1496static int
1497__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1498{
1499 struct irqaction *old, **old_ptr;
1500 unsigned long flags, thread_mask = 0;
1501 int ret, nested, shared = 0;
1502
1503 if (!desc)
1504 return -EINVAL;
1505
1506 if (desc->irq_data.chip == &no_irq_chip)
1507 return -ENOSYS;
1508 if (!try_module_get(desc->owner))
1509 return -ENODEV;
1510
1511 new->irq = irq;
1512
1513 /*
1514 * If the trigger type is not specified by the caller,
1515 * then use the default for this interrupt.
1516 */
1517 if (!(new->flags & IRQF_TRIGGER_MASK))
1518 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1519
1520 /*
1521 * Check whether the interrupt nests into another interrupt
1522 * thread.
1523 */
1524 nested = irq_settings_is_nested_thread(desc);
1525 if (nested) {
1526 if (!new->thread_fn) {
1527 ret = -EINVAL;
1528 goto out_mput;
1529 }
1530 /*
1531 * Replace the primary handler which was provided from
1532 * the driver for non nested interrupt handling by the
1533 * dummy function which warns when called.
1534 */
1535 new->handler = irq_nested_primary_handler;
1536 } else {
1537 if (irq_settings_can_thread(desc)) {
1538 ret = irq_setup_forced_threading(new);
1539 if (ret)
1540 goto out_mput;
1541 }
1542 }
1543
1544 /*
1545 * Create a handler thread when a thread function is supplied
1546 * and the interrupt does not nest into another interrupt
1547 * thread.
1548 */
1549 if (new->thread_fn && !nested) {
1550 ret = setup_irq_thread(new, irq, false);
1551 if (ret)
1552 goto out_mput;
1553 if (new->secondary) {
1554 ret = setup_irq_thread(new->secondary, irq, true);
1555 if (ret)
1556 goto out_thread;
1557 }
1558 }
1559
1560 /*
1561 * Drivers are often written to work w/o knowledge about the
1562 * underlying irq chip implementation, so a request for a
1563 * threaded irq without a primary hard irq context handler
1564 * requires the ONESHOT flag to be set. Some irq chips like
1565 * MSI based interrupts are per se one shot safe. Check the
1566 * chip flags, so we can avoid the unmask dance at the end of
1567 * the threaded handler for those.
1568 */
1569 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1570 new->flags &= ~IRQF_ONESHOT;
1571
1572 /*
1573 * Protects against a concurrent __free_irq() call which might wait
1574 * for synchronize_hardirq() to complete without holding the optional
1575 * chip bus lock and desc->lock. Also protects against handing out
1576 * a recycled oneshot thread_mask bit while it's still in use by
1577 * its previous owner.
1578 */
1579 mutex_lock(&desc->request_mutex);
1580
1581 /*
1582 * Acquire bus lock as the irq_request_resources() callback below
1583 * might rely on the serialization or the magic power management
1584 * functions which are abusing the irq_bus_lock() callback,
1585 */
1586 chip_bus_lock(desc);
1587
1588 /* First installed action requests resources. */
1589 if (!desc->action) {
1590 ret = irq_request_resources(desc);
1591 if (ret) {
1592 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1593 new->name, irq, desc->irq_data.chip->name);
1594 goto out_bus_unlock;
1595 }
1596 }
1597
1598 /*
1599 * The following block of code has to be executed atomically
1600 * protected against a concurrent interrupt and any of the other
1601 * management calls which are not serialized via
1602 * desc->request_mutex or the optional bus lock.
1603 */
1604 raw_spin_lock_irqsave(&desc->lock, flags);
1605 old_ptr = &desc->action;
1606 old = *old_ptr;
1607 if (old) {
1608 /*
1609 * Can't share interrupts unless both agree to and are
1610 * the same type (level, edge, polarity). So both flag
1611 * fields must have IRQF_SHARED set and the bits which
1612 * set the trigger type must match. Also all must
1613 * agree on ONESHOT.
1614 * Interrupt lines used for NMIs cannot be shared.
1615 */
1616 unsigned int oldtype;
1617
1618 if (desc->istate & IRQS_NMI) {
1619 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1620 new->name, irq, desc->irq_data.chip->name);
1621 ret = -EINVAL;
1622 goto out_unlock;
1623 }
1624
1625 /*
1626 * If nobody did set the configuration before, inherit
1627 * the one provided by the requester.
1628 */
1629 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1630 oldtype = irqd_get_trigger_type(&desc->irq_data);
1631 } else {
1632 oldtype = new->flags & IRQF_TRIGGER_MASK;
1633 irqd_set_trigger_type(&desc->irq_data, oldtype);
1634 }
1635
1636 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1637 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1638 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1639 goto mismatch;
1640
1641 /* All handlers must agree on per-cpuness */
1642 if ((old->flags & IRQF_PERCPU) !=
1643 (new->flags & IRQF_PERCPU))
1644 goto mismatch;
1645
1646 /* add new interrupt at end of irq queue */
1647 do {
1648 /*
1649 * Or all existing action->thread_mask bits,
1650 * so we can find the next zero bit for this
1651 * new action.
1652 */
1653 thread_mask |= old->thread_mask;
1654 old_ptr = &old->next;
1655 old = *old_ptr;
1656 } while (old);
1657 shared = 1;
1658 }
1659
1660 /*
1661 * Setup the thread mask for this irqaction for ONESHOT. For
1662 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1663 * conditional in irq_wake_thread().
1664 */
1665 if (new->flags & IRQF_ONESHOT) {
1666 /*
1667 * Unlikely to have 32 resp 64 irqs sharing one line,
1668 * but who knows.
1669 */
1670 if (thread_mask == ~0UL) {
1671 ret = -EBUSY;
1672 goto out_unlock;
1673 }
1674 /*
1675 * The thread_mask for the action is or'ed to
1676 * desc->thread_active to indicate that the
1677 * IRQF_ONESHOT thread handler has been woken, but not
1678 * yet finished. The bit is cleared when a thread
1679 * completes. When all threads of a shared interrupt
1680 * line have completed desc->threads_active becomes
1681 * zero and the interrupt line is unmasked. See
1682 * handle.c:irq_wake_thread() for further information.
1683 *
1684 * If no thread is woken by primary (hard irq context)
1685 * interrupt handlers, then desc->threads_active is
1686 * also checked for zero to unmask the irq line in the
1687 * affected hard irq flow handlers
1688 * (handle_[fasteoi|level]_irq).
1689 *
1690 * The new action gets the first zero bit of
1691 * thread_mask assigned. See the loop above which or's
1692 * all existing action->thread_mask bits.
1693 */
1694 new->thread_mask = 1UL << ffz(thread_mask);
1695
1696 } else if (new->handler == irq_default_primary_handler &&
1697 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1698 /*
1699 * The interrupt was requested with handler = NULL, so
1700 * we use the default primary handler for it. But it
1701 * does not have the oneshot flag set. In combination
1702 * with level interrupts this is deadly, because the
1703 * default primary handler just wakes the thread, then
1704 * the irq lines is reenabled, but the device still
1705 * has the level irq asserted. Rinse and repeat....
1706 *
1707 * While this works for edge type interrupts, we play
1708 * it safe and reject unconditionally because we can't
1709 * say for sure which type this interrupt really
1710 * has. The type flags are unreliable as the
1711 * underlying chip implementation can override them.
1712 */
1713 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1714 new->name, irq);
1715 ret = -EINVAL;
1716 goto out_unlock;
1717 }
1718
1719 if (!shared) {
1720 /* Setup the type (level, edge polarity) if configured: */
1721 if (new->flags & IRQF_TRIGGER_MASK) {
1722 ret = __irq_set_trigger(desc,
1723 new->flags & IRQF_TRIGGER_MASK);
1724
1725 if (ret)
1726 goto out_unlock;
1727 }
1728
1729 /*
1730 * Activate the interrupt. That activation must happen
1731 * independently of IRQ_NOAUTOEN. request_irq() can fail
1732 * and the callers are supposed to handle
1733 * that. enable_irq() of an interrupt requested with
1734 * IRQ_NOAUTOEN is not supposed to fail. The activation
1735 * keeps it in shutdown mode, it merily associates
1736 * resources if necessary and if that's not possible it
1737 * fails. Interrupts which are in managed shutdown mode
1738 * will simply ignore that activation request.
1739 */
1740 ret = irq_activate(desc);
1741 if (ret)
1742 goto out_unlock;
1743
1744 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1745 IRQS_ONESHOT | IRQS_WAITING);
1746 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1747
1748 if (new->flags & IRQF_PERCPU) {
1749 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1750 irq_settings_set_per_cpu(desc);
1751 if (new->flags & IRQF_NO_DEBUG)
1752 irq_settings_set_no_debug(desc);
1753 }
1754
1755 if (noirqdebug)
1756 irq_settings_set_no_debug(desc);
1757
1758 if (new->flags & IRQF_ONESHOT)
1759 desc->istate |= IRQS_ONESHOT;
1760
1761 /* Exclude IRQ from balancing if requested */
1762 if (new->flags & IRQF_NOBALANCING) {
1763 irq_settings_set_no_balancing(desc);
1764 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1765 }
1766
1767 if (!(new->flags & IRQF_NO_AUTOEN) &&
1768 irq_settings_can_autoenable(desc)) {
1769 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1770 } else {
1771 /*
1772 * Shared interrupts do not go well with disabling
1773 * auto enable. The sharing interrupt might request
1774 * it while it's still disabled and then wait for
1775 * interrupts forever.
1776 */
1777 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1778 /* Undo nested disables: */
1779 desc->depth = 1;
1780 }
1781
1782 } else if (new->flags & IRQF_TRIGGER_MASK) {
1783 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1784 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1785
1786 if (nmsk != omsk)
1787 /* hope the handler works with current trigger mode */
1788 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1789 irq, omsk, nmsk);
1790 }
1791
1792 *old_ptr = new;
1793
1794 irq_pm_install_action(desc, new);
1795
1796 /* Reset broken irq detection when installing new handler */
1797 desc->irq_count = 0;
1798 desc->irqs_unhandled = 0;
1799
1800 /*
1801 * Check whether we disabled the irq via the spurious handler
1802 * before. Reenable it and give it another chance.
1803 */
1804 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1805 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1806 __enable_irq(desc);
1807 }
1808
1809 raw_spin_unlock_irqrestore(&desc->lock, flags);
1810 chip_bus_sync_unlock(desc);
1811 mutex_unlock(&desc->request_mutex);
1812
1813 irq_setup_timings(desc, new);
1814
1815 wake_up_and_wait_for_irq_thread_ready(desc, new);
1816 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1817
1818 register_irq_proc(irq, desc);
1819 new->dir = NULL;
1820 register_handler_proc(irq, new);
1821 return 0;
1822
1823mismatch:
1824 if (!(new->flags & IRQF_PROBE_SHARED)) {
1825 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1826 irq, new->flags, new->name, old->flags, old->name);
1827#ifdef CONFIG_DEBUG_SHIRQ
1828 dump_stack();
1829#endif
1830 }
1831 ret = -EBUSY;
1832
1833out_unlock:
1834 raw_spin_unlock_irqrestore(&desc->lock, flags);
1835
1836 if (!desc->action)
1837 irq_release_resources(desc);
1838out_bus_unlock:
1839 chip_bus_sync_unlock(desc);
1840 mutex_unlock(&desc->request_mutex);
1841
1842out_thread:
1843 if (new->thread) {
1844 struct task_struct *t = new->thread;
1845
1846 new->thread = NULL;
1847 kthread_stop(t);
1848 put_task_struct(t);
1849 }
1850 if (new->secondary && new->secondary->thread) {
1851 struct task_struct *t = new->secondary->thread;
1852
1853 new->secondary->thread = NULL;
1854 kthread_stop(t);
1855 put_task_struct(t);
1856 }
1857out_mput:
1858 module_put(desc->owner);
1859 return ret;
1860}
1861
1862/*
1863 * Internal function to unregister an irqaction - used to free
1864 * regular and special interrupts that are part of the architecture.
1865 */
1866static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1867{
1868 unsigned irq = desc->irq_data.irq;
1869 struct irqaction *action, **action_ptr;
1870 unsigned long flags;
1871
1872 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1873
1874 mutex_lock(&desc->request_mutex);
1875 chip_bus_lock(desc);
1876 raw_spin_lock_irqsave(&desc->lock, flags);
1877
1878 /*
1879 * There can be multiple actions per IRQ descriptor, find the right
1880 * one based on the dev_id:
1881 */
1882 action_ptr = &desc->action;
1883 for (;;) {
1884 action = *action_ptr;
1885
1886 if (!action) {
1887 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1888 raw_spin_unlock_irqrestore(&desc->lock, flags);
1889 chip_bus_sync_unlock(desc);
1890 mutex_unlock(&desc->request_mutex);
1891 return NULL;
1892 }
1893
1894 if (action->dev_id == dev_id)
1895 break;
1896 action_ptr = &action->next;
1897 }
1898
1899 /* Found it - now remove it from the list of entries: */
1900 *action_ptr = action->next;
1901
1902 irq_pm_remove_action(desc, action);
1903
1904 /* If this was the last handler, shut down the IRQ line: */
1905 if (!desc->action) {
1906 irq_settings_clr_disable_unlazy(desc);
1907 /* Only shutdown. Deactivate after synchronize_hardirq() */
1908 irq_shutdown(desc);
1909 }
1910
1911#ifdef CONFIG_SMP
1912 /* make sure affinity_hint is cleaned up */
1913 if (WARN_ON_ONCE(desc->affinity_hint))
1914 desc->affinity_hint = NULL;
1915#endif
1916
1917 raw_spin_unlock_irqrestore(&desc->lock, flags);
1918 /*
1919 * Drop bus_lock here so the changes which were done in the chip
1920 * callbacks above are synced out to the irq chips which hang
1921 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1922 *
1923 * Aside of that the bus_lock can also be taken from the threaded
1924 * handler in irq_finalize_oneshot() which results in a deadlock
1925 * because kthread_stop() would wait forever for the thread to
1926 * complete, which is blocked on the bus lock.
1927 *
1928 * The still held desc->request_mutex() protects against a
1929 * concurrent request_irq() of this irq so the release of resources
1930 * and timing data is properly serialized.
1931 */
1932 chip_bus_sync_unlock(desc);
1933
1934 unregister_handler_proc(irq, action);
1935
1936 /*
1937 * Make sure it's not being used on another CPU and if the chip
1938 * supports it also make sure that there is no (not yet serviced)
1939 * interrupt in flight at the hardware level.
1940 */
1941 __synchronize_hardirq(desc, true);
1942
1943#ifdef CONFIG_DEBUG_SHIRQ
1944 /*
1945 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1946 * event to happen even now it's being freed, so let's make sure that
1947 * is so by doing an extra call to the handler ....
1948 *
1949 * ( We do this after actually deregistering it, to make sure that a
1950 * 'real' IRQ doesn't run in parallel with our fake. )
1951 */
1952 if (action->flags & IRQF_SHARED) {
1953 local_irq_save(flags);
1954 action->handler(irq, dev_id);
1955 local_irq_restore(flags);
1956 }
1957#endif
1958
1959 /*
1960 * The action has already been removed above, but the thread writes
1961 * its oneshot mask bit when it completes. Though request_mutex is
1962 * held across this which prevents __setup_irq() from handing out
1963 * the same bit to a newly requested action.
1964 */
1965 if (action->thread) {
1966 kthread_stop(action->thread);
1967 put_task_struct(action->thread);
1968 if (action->secondary && action->secondary->thread) {
1969 kthread_stop(action->secondary->thread);
1970 put_task_struct(action->secondary->thread);
1971 }
1972 }
1973
1974 /* Last action releases resources */
1975 if (!desc->action) {
1976 /*
1977 * Reacquire bus lock as irq_release_resources() might
1978 * require it to deallocate resources over the slow bus.
1979 */
1980 chip_bus_lock(desc);
1981 /*
1982 * There is no interrupt on the fly anymore. Deactivate it
1983 * completely.
1984 */
1985 raw_spin_lock_irqsave(&desc->lock, flags);
1986 irq_domain_deactivate_irq(&desc->irq_data);
1987 raw_spin_unlock_irqrestore(&desc->lock, flags);
1988
1989 irq_release_resources(desc);
1990 chip_bus_sync_unlock(desc);
1991 irq_remove_timings(desc);
1992 }
1993
1994 mutex_unlock(&desc->request_mutex);
1995
1996 irq_chip_pm_put(&desc->irq_data);
1997 module_put(desc->owner);
1998 kfree(action->secondary);
1999 return action;
2000}
2001
2002/**
2003 * free_irq - free an interrupt allocated with request_irq
2004 * @irq: Interrupt line to free
2005 * @dev_id: Device identity to free
2006 *
2007 * Remove an interrupt handler. The handler is removed and if the
2008 * interrupt line is no longer in use by any driver it is disabled.
2009 * On a shared IRQ the caller must ensure the interrupt is disabled
2010 * on the card it drives before calling this function. The function
2011 * does not return until any executing interrupts for this IRQ
2012 * have completed.
2013 *
2014 * This function must not be called from interrupt context.
2015 *
2016 * Returns the devname argument passed to request_irq.
2017 */
2018const void *free_irq(unsigned int irq, void *dev_id)
2019{
2020 struct irq_desc *desc = irq_to_desc(irq);
2021 struct irqaction *action;
2022 const char *devname;
2023
2024 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2025 return NULL;
2026
2027#ifdef CONFIG_SMP
2028 if (WARN_ON(desc->affinity_notify))
2029 desc->affinity_notify = NULL;
2030#endif
2031
2032 action = __free_irq(desc, dev_id);
2033
2034 if (!action)
2035 return NULL;
2036
2037 devname = action->name;
2038 kfree(action);
2039 return devname;
2040}
2041EXPORT_SYMBOL(free_irq);
2042
2043/* This function must be called with desc->lock held */
2044static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2045{
2046 const char *devname = NULL;
2047
2048 desc->istate &= ~IRQS_NMI;
2049
2050 if (!WARN_ON(desc->action == NULL)) {
2051 irq_pm_remove_action(desc, desc->action);
2052 devname = desc->action->name;
2053 unregister_handler_proc(irq, desc->action);
2054
2055 kfree(desc->action);
2056 desc->action = NULL;
2057 }
2058
2059 irq_settings_clr_disable_unlazy(desc);
2060 irq_shutdown_and_deactivate(desc);
2061
2062 irq_release_resources(desc);
2063
2064 irq_chip_pm_put(&desc->irq_data);
2065 module_put(desc->owner);
2066
2067 return devname;
2068}
2069
2070const void *free_nmi(unsigned int irq, void *dev_id)
2071{
2072 struct irq_desc *desc = irq_to_desc(irq);
2073 unsigned long flags;
2074 const void *devname;
2075
2076 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2077 return NULL;
2078
2079 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2080 return NULL;
2081
2082 /* NMI still enabled */
2083 if (WARN_ON(desc->depth == 0))
2084 disable_nmi_nosync(irq);
2085
2086 raw_spin_lock_irqsave(&desc->lock, flags);
2087
2088 irq_nmi_teardown(desc);
2089 devname = __cleanup_nmi(irq, desc);
2090
2091 raw_spin_unlock_irqrestore(&desc->lock, flags);
2092
2093 return devname;
2094}
2095
2096/**
2097 * request_threaded_irq - allocate an interrupt line
2098 * @irq: Interrupt line to allocate
2099 * @handler: Function to be called when the IRQ occurs.
2100 * Primary handler for threaded interrupts.
2101 * If handler is NULL and thread_fn != NULL
2102 * the default primary handler is installed.
2103 * @thread_fn: Function called from the irq handler thread
2104 * If NULL, no irq thread is created
2105 * @irqflags: Interrupt type flags
2106 * @devname: An ascii name for the claiming device
2107 * @dev_id: A cookie passed back to the handler function
2108 *
2109 * This call allocates interrupt resources and enables the
2110 * interrupt line and IRQ handling. From the point this
2111 * call is made your handler function may be invoked. Since
2112 * your handler function must clear any interrupt the board
2113 * raises, you must take care both to initialise your hardware
2114 * and to set up the interrupt handler in the right order.
2115 *
2116 * If you want to set up a threaded irq handler for your device
2117 * then you need to supply @handler and @thread_fn. @handler is
2118 * still called in hard interrupt context and has to check
2119 * whether the interrupt originates from the device. If yes it
2120 * needs to disable the interrupt on the device and return
2121 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2122 * @thread_fn. This split handler design is necessary to support
2123 * shared interrupts.
2124 *
2125 * Dev_id must be globally unique. Normally the address of the
2126 * device data structure is used as the cookie. Since the handler
2127 * receives this value it makes sense to use it.
2128 *
2129 * If your interrupt is shared you must pass a non NULL dev_id
2130 * as this is required when freeing the interrupt.
2131 *
2132 * Flags:
2133 *
2134 * IRQF_SHARED Interrupt is shared
2135 * IRQF_TRIGGER_* Specify active edge(s) or level
2136 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2137 */
2138int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2139 irq_handler_t thread_fn, unsigned long irqflags,
2140 const char *devname, void *dev_id)
2141{
2142 struct irqaction *action;
2143 struct irq_desc *desc;
2144 int retval;
2145
2146 if (irq == IRQ_NOTCONNECTED)
2147 return -ENOTCONN;
2148
2149 /*
2150 * Sanity-check: shared interrupts must pass in a real dev-ID,
2151 * otherwise we'll have trouble later trying to figure out
2152 * which interrupt is which (messes up the interrupt freeing
2153 * logic etc).
2154 *
2155 * Also shared interrupts do not go well with disabling auto enable.
2156 * The sharing interrupt might request it while it's still disabled
2157 * and then wait for interrupts forever.
2158 *
2159 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2160 * it cannot be set along with IRQF_NO_SUSPEND.
2161 */
2162 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2163 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2164 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2165 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2166 return -EINVAL;
2167
2168 desc = irq_to_desc(irq);
2169 if (!desc)
2170 return -EINVAL;
2171
2172 if (!irq_settings_can_request(desc) ||
2173 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2174 return -EINVAL;
2175
2176 if (!handler) {
2177 if (!thread_fn)
2178 return -EINVAL;
2179 handler = irq_default_primary_handler;
2180 }
2181
2182 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2183 if (!action)
2184 return -ENOMEM;
2185
2186 action->handler = handler;
2187 action->thread_fn = thread_fn;
2188 action->flags = irqflags;
2189 action->name = devname;
2190 action->dev_id = dev_id;
2191
2192 retval = irq_chip_pm_get(&desc->irq_data);
2193 if (retval < 0) {
2194 kfree(action);
2195 return retval;
2196 }
2197
2198 retval = __setup_irq(irq, desc, action);
2199
2200 if (retval) {
2201 irq_chip_pm_put(&desc->irq_data);
2202 kfree(action->secondary);
2203 kfree(action);
2204 }
2205
2206#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2207 if (!retval && (irqflags & IRQF_SHARED)) {
2208 /*
2209 * It's a shared IRQ -- the driver ought to be prepared for it
2210 * to happen immediately, so let's make sure....
2211 * We disable the irq to make sure that a 'real' IRQ doesn't
2212 * run in parallel with our fake.
2213 */
2214 unsigned long flags;
2215
2216 disable_irq(irq);
2217 local_irq_save(flags);
2218
2219 handler(irq, dev_id);
2220
2221 local_irq_restore(flags);
2222 enable_irq(irq);
2223 }
2224#endif
2225 return retval;
2226}
2227EXPORT_SYMBOL(request_threaded_irq);
2228
2229/**
2230 * request_any_context_irq - allocate an interrupt line
2231 * @irq: Interrupt line to allocate
2232 * @handler: Function to be called when the IRQ occurs.
2233 * Threaded handler for threaded interrupts.
2234 * @flags: Interrupt type flags
2235 * @name: An ascii name for the claiming device
2236 * @dev_id: A cookie passed back to the handler function
2237 *
2238 * This call allocates interrupt resources and enables the
2239 * interrupt line and IRQ handling. It selects either a
2240 * hardirq or threaded handling method depending on the
2241 * context.
2242 *
2243 * On failure, it returns a negative value. On success,
2244 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2245 */
2246int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2247 unsigned long flags, const char *name, void *dev_id)
2248{
2249 struct irq_desc *desc;
2250 int ret;
2251
2252 if (irq == IRQ_NOTCONNECTED)
2253 return -ENOTCONN;
2254
2255 desc = irq_to_desc(irq);
2256 if (!desc)
2257 return -EINVAL;
2258
2259 if (irq_settings_is_nested_thread(desc)) {
2260 ret = request_threaded_irq(irq, NULL, handler,
2261 flags, name, dev_id);
2262 return !ret ? IRQC_IS_NESTED : ret;
2263 }
2264
2265 ret = request_irq(irq, handler, flags, name, dev_id);
2266 return !ret ? IRQC_IS_HARDIRQ : ret;
2267}
2268EXPORT_SYMBOL_GPL(request_any_context_irq);
2269
2270/**
2271 * request_nmi - allocate an interrupt line for NMI delivery
2272 * @irq: Interrupt line to allocate
2273 * @handler: Function to be called when the IRQ occurs.
2274 * Threaded handler for threaded interrupts.
2275 * @irqflags: Interrupt type flags
2276 * @name: An ascii name for the claiming device
2277 * @dev_id: A cookie passed back to the handler function
2278 *
2279 * This call allocates interrupt resources and enables the
2280 * interrupt line and IRQ handling. It sets up the IRQ line
2281 * to be handled as an NMI.
2282 *
2283 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2284 * cannot be threaded.
2285 *
2286 * Interrupt lines requested for NMI delivering must produce per cpu
2287 * interrupts and have auto enabling setting disabled.
2288 *
2289 * Dev_id must be globally unique. Normally the address of the
2290 * device data structure is used as the cookie. Since the handler
2291 * receives this value it makes sense to use it.
2292 *
2293 * If the interrupt line cannot be used to deliver NMIs, function
2294 * will fail and return a negative value.
2295 */
2296int request_nmi(unsigned int irq, irq_handler_t handler,
2297 unsigned long irqflags, const char *name, void *dev_id)
2298{
2299 struct irqaction *action;
2300 struct irq_desc *desc;
2301 unsigned long flags;
2302 int retval;
2303
2304 if (irq == IRQ_NOTCONNECTED)
2305 return -ENOTCONN;
2306
2307 /* NMI cannot be shared, used for Polling */
2308 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2309 return -EINVAL;
2310
2311 if (!(irqflags & IRQF_PERCPU))
2312 return -EINVAL;
2313
2314 if (!handler)
2315 return -EINVAL;
2316
2317 desc = irq_to_desc(irq);
2318
2319 if (!desc || (irq_settings_can_autoenable(desc) &&
2320 !(irqflags & IRQF_NO_AUTOEN)) ||
2321 !irq_settings_can_request(desc) ||
2322 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2323 !irq_supports_nmi(desc))
2324 return -EINVAL;
2325
2326 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2327 if (!action)
2328 return -ENOMEM;
2329
2330 action->handler = handler;
2331 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2332 action->name = name;
2333 action->dev_id = dev_id;
2334
2335 retval = irq_chip_pm_get(&desc->irq_data);
2336 if (retval < 0)
2337 goto err_out;
2338
2339 retval = __setup_irq(irq, desc, action);
2340 if (retval)
2341 goto err_irq_setup;
2342
2343 raw_spin_lock_irqsave(&desc->lock, flags);
2344
2345 /* Setup NMI state */
2346 desc->istate |= IRQS_NMI;
2347 retval = irq_nmi_setup(desc);
2348 if (retval) {
2349 __cleanup_nmi(irq, desc);
2350 raw_spin_unlock_irqrestore(&desc->lock, flags);
2351 return -EINVAL;
2352 }
2353
2354 raw_spin_unlock_irqrestore(&desc->lock, flags);
2355
2356 return 0;
2357
2358err_irq_setup:
2359 irq_chip_pm_put(&desc->irq_data);
2360err_out:
2361 kfree(action);
2362
2363 return retval;
2364}
2365
2366void enable_percpu_irq(unsigned int irq, unsigned int type)
2367{
2368 unsigned int cpu = smp_processor_id();
2369 unsigned long flags;
2370 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2371
2372 if (!desc)
2373 return;
2374
2375 /*
2376 * If the trigger type is not specified by the caller, then
2377 * use the default for this interrupt.
2378 */
2379 type &= IRQ_TYPE_SENSE_MASK;
2380 if (type == IRQ_TYPE_NONE)
2381 type = irqd_get_trigger_type(&desc->irq_data);
2382
2383 if (type != IRQ_TYPE_NONE) {
2384 int ret;
2385
2386 ret = __irq_set_trigger(desc, type);
2387
2388 if (ret) {
2389 WARN(1, "failed to set type for IRQ%d\n", irq);
2390 goto out;
2391 }
2392 }
2393
2394 irq_percpu_enable(desc, cpu);
2395out:
2396 irq_put_desc_unlock(desc, flags);
2397}
2398EXPORT_SYMBOL_GPL(enable_percpu_irq);
2399
2400void enable_percpu_nmi(unsigned int irq, unsigned int type)
2401{
2402 enable_percpu_irq(irq, type);
2403}
2404
2405/**
2406 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2407 * @irq: Linux irq number to check for
2408 *
2409 * Must be called from a non migratable context. Returns the enable
2410 * state of a per cpu interrupt on the current cpu.
2411 */
2412bool irq_percpu_is_enabled(unsigned int irq)
2413{
2414 unsigned int cpu = smp_processor_id();
2415 struct irq_desc *desc;
2416 unsigned long flags;
2417 bool is_enabled;
2418
2419 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2420 if (!desc)
2421 return false;
2422
2423 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2424 irq_put_desc_unlock(desc, flags);
2425
2426 return is_enabled;
2427}
2428EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2429
2430void disable_percpu_irq(unsigned int irq)
2431{
2432 unsigned int cpu = smp_processor_id();
2433 unsigned long flags;
2434 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2435
2436 if (!desc)
2437 return;
2438
2439 irq_percpu_disable(desc, cpu);
2440 irq_put_desc_unlock(desc, flags);
2441}
2442EXPORT_SYMBOL_GPL(disable_percpu_irq);
2443
2444void disable_percpu_nmi(unsigned int irq)
2445{
2446 disable_percpu_irq(irq);
2447}
2448
2449/*
2450 * Internal function to unregister a percpu irqaction.
2451 */
2452static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2453{
2454 struct irq_desc *desc = irq_to_desc(irq);
2455 struct irqaction *action;
2456 unsigned long flags;
2457
2458 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2459
2460 if (!desc)
2461 return NULL;
2462
2463 raw_spin_lock_irqsave(&desc->lock, flags);
2464
2465 action = desc->action;
2466 if (!action || action->percpu_dev_id != dev_id) {
2467 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2468 goto bad;
2469 }
2470
2471 if (!cpumask_empty(desc->percpu_enabled)) {
2472 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2473 irq, cpumask_first(desc->percpu_enabled));
2474 goto bad;
2475 }
2476
2477 /* Found it - now remove it from the list of entries: */
2478 desc->action = NULL;
2479
2480 desc->istate &= ~IRQS_NMI;
2481
2482 raw_spin_unlock_irqrestore(&desc->lock, flags);
2483
2484 unregister_handler_proc(irq, action);
2485
2486 irq_chip_pm_put(&desc->irq_data);
2487 module_put(desc->owner);
2488 return action;
2489
2490bad:
2491 raw_spin_unlock_irqrestore(&desc->lock, flags);
2492 return NULL;
2493}
2494
2495/**
2496 * remove_percpu_irq - free a per-cpu interrupt
2497 * @irq: Interrupt line to free
2498 * @act: irqaction for the interrupt
2499 *
2500 * Used to remove interrupts statically setup by the early boot process.
2501 */
2502void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2503{
2504 struct irq_desc *desc = irq_to_desc(irq);
2505
2506 if (desc && irq_settings_is_per_cpu_devid(desc))
2507 __free_percpu_irq(irq, act->percpu_dev_id);
2508}
2509
2510/**
2511 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2512 * @irq: Interrupt line to free
2513 * @dev_id: Device identity to free
2514 *
2515 * Remove a percpu interrupt handler. The handler is removed, but
2516 * the interrupt line is not disabled. This must be done on each
2517 * CPU before calling this function. The function does not return
2518 * until any executing interrupts for this IRQ have completed.
2519 *
2520 * This function must not be called from interrupt context.
2521 */
2522void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2523{
2524 struct irq_desc *desc = irq_to_desc(irq);
2525
2526 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2527 return;
2528
2529 chip_bus_lock(desc);
2530 kfree(__free_percpu_irq(irq, dev_id));
2531 chip_bus_sync_unlock(desc);
2532}
2533EXPORT_SYMBOL_GPL(free_percpu_irq);
2534
2535void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2536{
2537 struct irq_desc *desc = irq_to_desc(irq);
2538
2539 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2540 return;
2541
2542 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2543 return;
2544
2545 kfree(__free_percpu_irq(irq, dev_id));
2546}
2547
2548/**
2549 * setup_percpu_irq - setup a per-cpu interrupt
2550 * @irq: Interrupt line to setup
2551 * @act: irqaction for the interrupt
2552 *
2553 * Used to statically setup per-cpu interrupts in the early boot process.
2554 */
2555int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2556{
2557 struct irq_desc *desc = irq_to_desc(irq);
2558 int retval;
2559
2560 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2561 return -EINVAL;
2562
2563 retval = irq_chip_pm_get(&desc->irq_data);
2564 if (retval < 0)
2565 return retval;
2566
2567 retval = __setup_irq(irq, desc, act);
2568
2569 if (retval)
2570 irq_chip_pm_put(&desc->irq_data);
2571
2572 return retval;
2573}
2574
2575/**
2576 * __request_percpu_irq - allocate a percpu interrupt line
2577 * @irq: Interrupt line to allocate
2578 * @handler: Function to be called when the IRQ occurs.
2579 * @flags: Interrupt type flags (IRQF_TIMER only)
2580 * @devname: An ascii name for the claiming device
2581 * @dev_id: A percpu cookie passed back to the handler function
2582 *
2583 * This call allocates interrupt resources and enables the
2584 * interrupt on the local CPU. If the interrupt is supposed to be
2585 * enabled on other CPUs, it has to be done on each CPU using
2586 * enable_percpu_irq().
2587 *
2588 * Dev_id must be globally unique. It is a per-cpu variable, and
2589 * the handler gets called with the interrupted CPU's instance of
2590 * that variable.
2591 */
2592int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2593 unsigned long flags, const char *devname,
2594 void __percpu *dev_id)
2595{
2596 struct irqaction *action;
2597 struct irq_desc *desc;
2598 int retval;
2599
2600 if (!dev_id)
2601 return -EINVAL;
2602
2603 desc = irq_to_desc(irq);
2604 if (!desc || !irq_settings_can_request(desc) ||
2605 !irq_settings_is_per_cpu_devid(desc))
2606 return -EINVAL;
2607
2608 if (flags && flags != IRQF_TIMER)
2609 return -EINVAL;
2610
2611 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2612 if (!action)
2613 return -ENOMEM;
2614
2615 action->handler = handler;
2616 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2617 action->name = devname;
2618 action->percpu_dev_id = dev_id;
2619
2620 retval = irq_chip_pm_get(&desc->irq_data);
2621 if (retval < 0) {
2622 kfree(action);
2623 return retval;
2624 }
2625
2626 retval = __setup_irq(irq, desc, action);
2627
2628 if (retval) {
2629 irq_chip_pm_put(&desc->irq_data);
2630 kfree(action);
2631 }
2632
2633 return retval;
2634}
2635EXPORT_SYMBOL_GPL(__request_percpu_irq);
2636
2637/**
2638 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2639 * @irq: Interrupt line to allocate
2640 * @handler: Function to be called when the IRQ occurs.
2641 * @name: An ascii name for the claiming device
2642 * @dev_id: A percpu cookie passed back to the handler function
2643 *
2644 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2645 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2646 * being enabled on the same CPU by using enable_percpu_nmi().
2647 *
2648 * Dev_id must be globally unique. It is a per-cpu variable, and
2649 * the handler gets called with the interrupted CPU's instance of
2650 * that variable.
2651 *
2652 * Interrupt lines requested for NMI delivering should have auto enabling
2653 * setting disabled.
2654 *
2655 * If the interrupt line cannot be used to deliver NMIs, function
2656 * will fail returning a negative value.
2657 */
2658int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2659 const char *name, void __percpu *dev_id)
2660{
2661 struct irqaction *action;
2662 struct irq_desc *desc;
2663 unsigned long flags;
2664 int retval;
2665
2666 if (!handler)
2667 return -EINVAL;
2668
2669 desc = irq_to_desc(irq);
2670
2671 if (!desc || !irq_settings_can_request(desc) ||
2672 !irq_settings_is_per_cpu_devid(desc) ||
2673 irq_settings_can_autoenable(desc) ||
2674 !irq_supports_nmi(desc))
2675 return -EINVAL;
2676
2677 /* The line cannot already be NMI */
2678 if (desc->istate & IRQS_NMI)
2679 return -EINVAL;
2680
2681 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2682 if (!action)
2683 return -ENOMEM;
2684
2685 action->handler = handler;
2686 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2687 | IRQF_NOBALANCING;
2688 action->name = name;
2689 action->percpu_dev_id = dev_id;
2690
2691 retval = irq_chip_pm_get(&desc->irq_data);
2692 if (retval < 0)
2693 goto err_out;
2694
2695 retval = __setup_irq(irq, desc, action);
2696 if (retval)
2697 goto err_irq_setup;
2698
2699 raw_spin_lock_irqsave(&desc->lock, flags);
2700 desc->istate |= IRQS_NMI;
2701 raw_spin_unlock_irqrestore(&desc->lock, flags);
2702
2703 return 0;
2704
2705err_irq_setup:
2706 irq_chip_pm_put(&desc->irq_data);
2707err_out:
2708 kfree(action);
2709
2710 return retval;
2711}
2712
2713/**
2714 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2715 * @irq: Interrupt line to prepare for NMI delivery
2716 *
2717 * This call prepares an interrupt line to deliver NMI on the current CPU,
2718 * before that interrupt line gets enabled with enable_percpu_nmi().
2719 *
2720 * As a CPU local operation, this should be called from non-preemptible
2721 * context.
2722 *
2723 * If the interrupt line cannot be used to deliver NMIs, function
2724 * will fail returning a negative value.
2725 */
2726int prepare_percpu_nmi(unsigned int irq)
2727{
2728 unsigned long flags;
2729 struct irq_desc *desc;
2730 int ret = 0;
2731
2732 WARN_ON(preemptible());
2733
2734 desc = irq_get_desc_lock(irq, &flags,
2735 IRQ_GET_DESC_CHECK_PERCPU);
2736 if (!desc)
2737 return -EINVAL;
2738
2739 if (WARN(!(desc->istate & IRQS_NMI),
2740 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2741 irq)) {
2742 ret = -EINVAL;
2743 goto out;
2744 }
2745
2746 ret = irq_nmi_setup(desc);
2747 if (ret) {
2748 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2749 goto out;
2750 }
2751
2752out:
2753 irq_put_desc_unlock(desc, flags);
2754 return ret;
2755}
2756
2757/**
2758 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2759 * @irq: Interrupt line from which CPU local NMI configuration should be
2760 * removed
2761 *
2762 * This call undoes the setup done by prepare_percpu_nmi().
2763 *
2764 * IRQ line should not be enabled for the current CPU.
2765 *
2766 * As a CPU local operation, this should be called from non-preemptible
2767 * context.
2768 */
2769void teardown_percpu_nmi(unsigned int irq)
2770{
2771 unsigned long flags;
2772 struct irq_desc *desc;
2773
2774 WARN_ON(preemptible());
2775
2776 desc = irq_get_desc_lock(irq, &flags,
2777 IRQ_GET_DESC_CHECK_PERCPU);
2778 if (!desc)
2779 return;
2780
2781 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2782 goto out;
2783
2784 irq_nmi_teardown(desc);
2785out:
2786 irq_put_desc_unlock(desc, flags);
2787}
2788
2789int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2790 bool *state)
2791{
2792 struct irq_chip *chip;
2793 int err = -EINVAL;
2794
2795 do {
2796 chip = irq_data_get_irq_chip(data);
2797 if (WARN_ON_ONCE(!chip))
2798 return -ENODEV;
2799 if (chip->irq_get_irqchip_state)
2800 break;
2801#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2802 data = data->parent_data;
2803#else
2804 data = NULL;
2805#endif
2806 } while (data);
2807
2808 if (data)
2809 err = chip->irq_get_irqchip_state(data, which, state);
2810 return err;
2811}
2812
2813/**
2814 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2815 * @irq: Interrupt line that is forwarded to a VM
2816 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2817 * @state: a pointer to a boolean where the state is to be stored
2818 *
2819 * This call snapshots the internal irqchip state of an
2820 * interrupt, returning into @state the bit corresponding to
2821 * stage @which
2822 *
2823 * This function should be called with preemption disabled if the
2824 * interrupt controller has per-cpu registers.
2825 */
2826int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2827 bool *state)
2828{
2829 struct irq_desc *desc;
2830 struct irq_data *data;
2831 unsigned long flags;
2832 int err = -EINVAL;
2833
2834 desc = irq_get_desc_buslock(irq, &flags, 0);
2835 if (!desc)
2836 return err;
2837
2838 data = irq_desc_get_irq_data(desc);
2839
2840 err = __irq_get_irqchip_state(data, which, state);
2841
2842 irq_put_desc_busunlock(desc, flags);
2843 return err;
2844}
2845EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2846
2847/**
2848 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2849 * @irq: Interrupt line that is forwarded to a VM
2850 * @which: State to be restored (one of IRQCHIP_STATE_*)
2851 * @val: Value corresponding to @which
2852 *
2853 * This call sets the internal irqchip state of an interrupt,
2854 * depending on the value of @which.
2855 *
2856 * This function should be called with migration disabled if the
2857 * interrupt controller has per-cpu registers.
2858 */
2859int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2860 bool val)
2861{
2862 struct irq_desc *desc;
2863 struct irq_data *data;
2864 struct irq_chip *chip;
2865 unsigned long flags;
2866 int err = -EINVAL;
2867
2868 desc = irq_get_desc_buslock(irq, &flags, 0);
2869 if (!desc)
2870 return err;
2871
2872 data = irq_desc_get_irq_data(desc);
2873
2874 do {
2875 chip = irq_data_get_irq_chip(data);
2876 if (WARN_ON_ONCE(!chip)) {
2877 err = -ENODEV;
2878 goto out_unlock;
2879 }
2880 if (chip->irq_set_irqchip_state)
2881 break;
2882#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2883 data = data->parent_data;
2884#else
2885 data = NULL;
2886#endif
2887 } while (data);
2888
2889 if (data)
2890 err = chip->irq_set_irqchip_state(data, which, val);
2891
2892out_unlock:
2893 irq_put_desc_busunlock(desc, flags);
2894 return err;
2895}
2896EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2897
2898/**
2899 * irq_has_action - Check whether an interrupt is requested
2900 * @irq: The linux irq number
2901 *
2902 * Returns: A snapshot of the current state
2903 */
2904bool irq_has_action(unsigned int irq)
2905{
2906 bool res;
2907
2908 rcu_read_lock();
2909 res = irq_desc_has_action(irq_to_desc(irq));
2910 rcu_read_unlock();
2911 return res;
2912}
2913EXPORT_SYMBOL_GPL(irq_has_action);
2914
2915/**
2916 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2917 * @irq: The linux irq number
2918 * @bitmask: The bitmask to evaluate
2919 *
2920 * Returns: True if one of the bits in @bitmask is set
2921 */
2922bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2923{
2924 struct irq_desc *desc;
2925 bool res = false;
2926
2927 rcu_read_lock();
2928 desc = irq_to_desc(irq);
2929 if (desc)
2930 res = !!(desc->status_use_accessors & bitmask);
2931 rcu_read_unlock();
2932 return res;
2933}
2934EXPORT_SYMBOL_GPL(irq_check_status_bit);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28__read_mostly bool force_irqthreads;
29EXPORT_SYMBOL_GPL(force_irqthreads);
30
31static int __init setup_forced_irqthreads(char *arg)
32{
33 force_irqthreads = true;
34 return 0;
35}
36early_param("threadirqs", setup_forced_irqthreads);
37#endif
38
39static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
40{
41 struct irq_data *irqd = irq_desc_get_irq_data(desc);
42 bool inprogress;
43
44 do {
45 unsigned long flags;
46
47 /*
48 * Wait until we're out of the critical section. This might
49 * give the wrong answer due to the lack of memory barriers.
50 */
51 while (irqd_irq_inprogress(&desc->irq_data))
52 cpu_relax();
53
54 /* Ok, that indicated we're done: double-check carefully. */
55 raw_spin_lock_irqsave(&desc->lock, flags);
56 inprogress = irqd_irq_inprogress(&desc->irq_data);
57
58 /*
59 * If requested and supported, check at the chip whether it
60 * is in flight at the hardware level, i.e. already pending
61 * in a CPU and waiting for service and acknowledge.
62 */
63 if (!inprogress && sync_chip) {
64 /*
65 * Ignore the return code. inprogress is only updated
66 * when the chip supports it.
67 */
68 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
69 &inprogress);
70 }
71 raw_spin_unlock_irqrestore(&desc->lock, flags);
72
73 /* Oops, that failed? */
74 } while (inprogress);
75}
76
77/**
78 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
79 * @irq: interrupt number to wait for
80 *
81 * This function waits for any pending hard IRQ handlers for this
82 * interrupt to complete before returning. If you use this
83 * function while holding a resource the IRQ handler may need you
84 * will deadlock. It does not take associated threaded handlers
85 * into account.
86 *
87 * Do not use this for shutdown scenarios where you must be sure
88 * that all parts (hardirq and threaded handler) have completed.
89 *
90 * Returns: false if a threaded handler is active.
91 *
92 * This function may be called - with care - from IRQ context.
93 *
94 * It does not check whether there is an interrupt in flight at the
95 * hardware level, but not serviced yet, as this might deadlock when
96 * called with interrupts disabled and the target CPU of the interrupt
97 * is the current CPU.
98 */
99bool synchronize_hardirq(unsigned int irq)
100{
101 struct irq_desc *desc = irq_to_desc(irq);
102
103 if (desc) {
104 __synchronize_hardirq(desc, false);
105 return !atomic_read(&desc->threads_active);
106 }
107
108 return true;
109}
110EXPORT_SYMBOL(synchronize_hardirq);
111
112/**
113 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
114 * @irq: interrupt number to wait for
115 *
116 * This function waits for any pending IRQ handlers for this interrupt
117 * to complete before returning. If you use this function while
118 * holding a resource the IRQ handler may need you will deadlock.
119 *
120 * Can only be called from preemptible code as it might sleep when
121 * an interrupt thread is associated to @irq.
122 *
123 * It optionally makes sure (when the irq chip supports that method)
124 * that the interrupt is not pending in any CPU and waiting for
125 * service.
126 */
127void synchronize_irq(unsigned int irq)
128{
129 struct irq_desc *desc = irq_to_desc(irq);
130
131 if (desc) {
132 __synchronize_hardirq(desc, true);
133 /*
134 * We made sure that no hardirq handler is
135 * running. Now verify that no threaded handlers are
136 * active.
137 */
138 wait_event(desc->wait_for_threads,
139 !atomic_read(&desc->threads_active));
140 }
141}
142EXPORT_SYMBOL(synchronize_irq);
143
144#ifdef CONFIG_SMP
145cpumask_var_t irq_default_affinity;
146
147static bool __irq_can_set_affinity(struct irq_desc *desc)
148{
149 if (!desc || !irqd_can_balance(&desc->irq_data) ||
150 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
151 return false;
152 return true;
153}
154
155/**
156 * irq_can_set_affinity - Check if the affinity of a given irq can be set
157 * @irq: Interrupt to check
158 *
159 */
160int irq_can_set_affinity(unsigned int irq)
161{
162 return __irq_can_set_affinity(irq_to_desc(irq));
163}
164
165/**
166 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
167 * @irq: Interrupt to check
168 *
169 * Like irq_can_set_affinity() above, but additionally checks for the
170 * AFFINITY_MANAGED flag.
171 */
172bool irq_can_set_affinity_usr(unsigned int irq)
173{
174 struct irq_desc *desc = irq_to_desc(irq);
175
176 return __irq_can_set_affinity(desc) &&
177 !irqd_affinity_is_managed(&desc->irq_data);
178}
179
180/**
181 * irq_set_thread_affinity - Notify irq threads to adjust affinity
182 * @desc: irq descriptor which has affinity changed
183 *
184 * We just set IRQTF_AFFINITY and delegate the affinity setting
185 * to the interrupt thread itself. We can not call
186 * set_cpus_allowed_ptr() here as we hold desc->lock and this
187 * code can be called from hard interrupt context.
188 */
189void irq_set_thread_affinity(struct irq_desc *desc)
190{
191 struct irqaction *action;
192
193 for_each_action_of_desc(desc, action)
194 if (action->thread)
195 set_bit(IRQTF_AFFINITY, &action->thread_flags);
196}
197
198#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
199static void irq_validate_effective_affinity(struct irq_data *data)
200{
201 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
202 struct irq_chip *chip = irq_data_get_irq_chip(data);
203
204 if (!cpumask_empty(m))
205 return;
206 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
207 chip->name, data->irq);
208}
209
210static inline void irq_init_effective_affinity(struct irq_data *data,
211 const struct cpumask *mask)
212{
213 cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
214}
215#else
216static inline void irq_validate_effective_affinity(struct irq_data *data) { }
217static inline void irq_init_effective_affinity(struct irq_data *data,
218 const struct cpumask *mask) { }
219#endif
220
221int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
222 bool force)
223{
224 struct irq_desc *desc = irq_data_to_desc(data);
225 struct irq_chip *chip = irq_data_get_irq_chip(data);
226 int ret;
227
228 if (!chip || !chip->irq_set_affinity)
229 return -EINVAL;
230
231 /*
232 * If this is a managed interrupt and housekeeping is enabled on
233 * it check whether the requested affinity mask intersects with
234 * a housekeeping CPU. If so, then remove the isolated CPUs from
235 * the mask and just keep the housekeeping CPU(s). This prevents
236 * the affinity setter from routing the interrupt to an isolated
237 * CPU to avoid that I/O submitted from a housekeeping CPU causes
238 * interrupts on an isolated one.
239 *
240 * If the masks do not intersect or include online CPU(s) then
241 * keep the requested mask. The isolated target CPUs are only
242 * receiving interrupts when the I/O operation was submitted
243 * directly from them.
244 *
245 * If all housekeeping CPUs in the affinity mask are offline, the
246 * interrupt will be migrated by the CPU hotplug code once a
247 * housekeeping CPU which belongs to the affinity mask comes
248 * online.
249 */
250 if (irqd_affinity_is_managed(data) &&
251 housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
252 const struct cpumask *hk_mask, *prog_mask;
253
254 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
255 static struct cpumask tmp_mask;
256
257 hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
258
259 raw_spin_lock(&tmp_mask_lock);
260 cpumask_and(&tmp_mask, mask, hk_mask);
261 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
262 prog_mask = mask;
263 else
264 prog_mask = &tmp_mask;
265 ret = chip->irq_set_affinity(data, prog_mask, force);
266 raw_spin_unlock(&tmp_mask_lock);
267 } else {
268 ret = chip->irq_set_affinity(data, mask, force);
269 }
270 switch (ret) {
271 case IRQ_SET_MASK_OK:
272 case IRQ_SET_MASK_OK_DONE:
273 cpumask_copy(desc->irq_common_data.affinity, mask);
274 fallthrough;
275 case IRQ_SET_MASK_OK_NOCOPY:
276 irq_validate_effective_affinity(data);
277 irq_set_thread_affinity(desc);
278 ret = 0;
279 }
280
281 return ret;
282}
283
284#ifdef CONFIG_GENERIC_PENDING_IRQ
285static inline int irq_set_affinity_pending(struct irq_data *data,
286 const struct cpumask *dest)
287{
288 struct irq_desc *desc = irq_data_to_desc(data);
289
290 irqd_set_move_pending(data);
291 irq_copy_pending(desc, dest);
292 return 0;
293}
294#else
295static inline int irq_set_affinity_pending(struct irq_data *data,
296 const struct cpumask *dest)
297{
298 return -EBUSY;
299}
300#endif
301
302static int irq_try_set_affinity(struct irq_data *data,
303 const struct cpumask *dest, bool force)
304{
305 int ret = irq_do_set_affinity(data, dest, force);
306
307 /*
308 * In case that the underlying vector management is busy and the
309 * architecture supports the generic pending mechanism then utilize
310 * this to avoid returning an error to user space.
311 */
312 if (ret == -EBUSY && !force)
313 ret = irq_set_affinity_pending(data, dest);
314 return ret;
315}
316
317static bool irq_set_affinity_deactivated(struct irq_data *data,
318 const struct cpumask *mask, bool force)
319{
320 struct irq_desc *desc = irq_data_to_desc(data);
321
322 /*
323 * Handle irq chips which can handle affinity only in activated
324 * state correctly
325 *
326 * If the interrupt is not yet activated, just store the affinity
327 * mask and do not call the chip driver at all. On activation the
328 * driver has to make sure anyway that the interrupt is in a
329 * usable state so startup works.
330 */
331 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
332 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
333 return false;
334
335 cpumask_copy(desc->irq_common_data.affinity, mask);
336 irq_init_effective_affinity(data, mask);
337 irqd_set(data, IRQD_AFFINITY_SET);
338 return true;
339}
340
341int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
342 bool force)
343{
344 struct irq_chip *chip = irq_data_get_irq_chip(data);
345 struct irq_desc *desc = irq_data_to_desc(data);
346 int ret = 0;
347
348 if (!chip || !chip->irq_set_affinity)
349 return -EINVAL;
350
351 if (irq_set_affinity_deactivated(data, mask, force))
352 return 0;
353
354 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
355 ret = irq_try_set_affinity(data, mask, force);
356 } else {
357 irqd_set_move_pending(data);
358 irq_copy_pending(desc, mask);
359 }
360
361 if (desc->affinity_notify) {
362 kref_get(&desc->affinity_notify->kref);
363 if (!schedule_work(&desc->affinity_notify->work)) {
364 /* Work was already scheduled, drop our extra ref */
365 kref_put(&desc->affinity_notify->kref,
366 desc->affinity_notify->release);
367 }
368 }
369 irqd_set(data, IRQD_AFFINITY_SET);
370
371 return ret;
372}
373
374/**
375 * irq_update_affinity_desc - Update affinity management for an interrupt
376 * @irq: The interrupt number to update
377 * @affinity: Pointer to the affinity descriptor
378 *
379 * This interface can be used to configure the affinity management of
380 * interrupts which have been allocated already.
381 *
382 * There are certain limitations on when it may be used - attempts to use it
383 * for when the kernel is configured for generic IRQ reservation mode (in
384 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
385 * managed/non-managed interrupt accounting. In addition, attempts to use it on
386 * an interrupt which is already started or which has already been configured
387 * as managed will also fail, as these mean invalid init state or double init.
388 */
389int irq_update_affinity_desc(unsigned int irq,
390 struct irq_affinity_desc *affinity)
391{
392 struct irq_desc *desc;
393 unsigned long flags;
394 bool activated;
395 int ret = 0;
396
397 /*
398 * Supporting this with the reservation scheme used by x86 needs
399 * some more thought. Fail it for now.
400 */
401 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
402 return -EOPNOTSUPP;
403
404 desc = irq_get_desc_buslock(irq, &flags, 0);
405 if (!desc)
406 return -EINVAL;
407
408 /* Requires the interrupt to be shut down */
409 if (irqd_is_started(&desc->irq_data)) {
410 ret = -EBUSY;
411 goto out_unlock;
412 }
413
414 /* Interrupts which are already managed cannot be modified */
415 if (irqd_affinity_is_managed(&desc->irq_data)) {
416 ret = -EBUSY;
417 goto out_unlock;
418 }
419
420 /*
421 * Deactivate the interrupt. That's required to undo
422 * anything an earlier activation has established.
423 */
424 activated = irqd_is_activated(&desc->irq_data);
425 if (activated)
426 irq_domain_deactivate_irq(&desc->irq_data);
427
428 if (affinity->is_managed) {
429 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
430 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
431 }
432
433 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
434
435 /* Restore the activation state */
436 if (activated)
437 irq_domain_activate_irq(&desc->irq_data, false);
438
439out_unlock:
440 irq_put_desc_busunlock(desc, flags);
441 return ret;
442}
443
444static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
445 bool force)
446{
447 struct irq_desc *desc = irq_to_desc(irq);
448 unsigned long flags;
449 int ret;
450
451 if (!desc)
452 return -EINVAL;
453
454 raw_spin_lock_irqsave(&desc->lock, flags);
455 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
456 raw_spin_unlock_irqrestore(&desc->lock, flags);
457 return ret;
458}
459
460/**
461 * irq_set_affinity - Set the irq affinity of a given irq
462 * @irq: Interrupt to set affinity
463 * @cpumask: cpumask
464 *
465 * Fails if cpumask does not contain an online CPU
466 */
467int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
468{
469 return __irq_set_affinity(irq, cpumask, false);
470}
471EXPORT_SYMBOL_GPL(irq_set_affinity);
472
473/**
474 * irq_force_affinity - Force the irq affinity of a given irq
475 * @irq: Interrupt to set affinity
476 * @cpumask: cpumask
477 *
478 * Same as irq_set_affinity, but without checking the mask against
479 * online cpus.
480 *
481 * Solely for low level cpu hotplug code, where we need to make per
482 * cpu interrupts affine before the cpu becomes online.
483 */
484int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
485{
486 return __irq_set_affinity(irq, cpumask, true);
487}
488EXPORT_SYMBOL_GPL(irq_force_affinity);
489
490int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
491{
492 unsigned long flags;
493 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
494
495 if (!desc)
496 return -EINVAL;
497 desc->affinity_hint = m;
498 irq_put_desc_unlock(desc, flags);
499 /* set the initial affinity to prevent every interrupt being on CPU0 */
500 if (m)
501 __irq_set_affinity(irq, m, false);
502 return 0;
503}
504EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
505
506static void irq_affinity_notify(struct work_struct *work)
507{
508 struct irq_affinity_notify *notify =
509 container_of(work, struct irq_affinity_notify, work);
510 struct irq_desc *desc = irq_to_desc(notify->irq);
511 cpumask_var_t cpumask;
512 unsigned long flags;
513
514 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
515 goto out;
516
517 raw_spin_lock_irqsave(&desc->lock, flags);
518 if (irq_move_pending(&desc->irq_data))
519 irq_get_pending(cpumask, desc);
520 else
521 cpumask_copy(cpumask, desc->irq_common_data.affinity);
522 raw_spin_unlock_irqrestore(&desc->lock, flags);
523
524 notify->notify(notify, cpumask);
525
526 free_cpumask_var(cpumask);
527out:
528 kref_put(¬ify->kref, notify->release);
529}
530
531/**
532 * irq_set_affinity_notifier - control notification of IRQ affinity changes
533 * @irq: Interrupt for which to enable/disable notification
534 * @notify: Context for notification, or %NULL to disable
535 * notification. Function pointers must be initialised;
536 * the other fields will be initialised by this function.
537 *
538 * Must be called in process context. Notification may only be enabled
539 * after the IRQ is allocated and must be disabled before the IRQ is
540 * freed using free_irq().
541 */
542int
543irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
544{
545 struct irq_desc *desc = irq_to_desc(irq);
546 struct irq_affinity_notify *old_notify;
547 unsigned long flags;
548
549 /* The release function is promised process context */
550 might_sleep();
551
552 if (!desc || desc->istate & IRQS_NMI)
553 return -EINVAL;
554
555 /* Complete initialisation of *notify */
556 if (notify) {
557 notify->irq = irq;
558 kref_init(¬ify->kref);
559 INIT_WORK(¬ify->work, irq_affinity_notify);
560 }
561
562 raw_spin_lock_irqsave(&desc->lock, flags);
563 old_notify = desc->affinity_notify;
564 desc->affinity_notify = notify;
565 raw_spin_unlock_irqrestore(&desc->lock, flags);
566
567 if (old_notify) {
568 if (cancel_work_sync(&old_notify->work)) {
569 /* Pending work had a ref, put that one too */
570 kref_put(&old_notify->kref, old_notify->release);
571 }
572 kref_put(&old_notify->kref, old_notify->release);
573 }
574
575 return 0;
576}
577EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
578
579#ifndef CONFIG_AUTO_IRQ_AFFINITY
580/*
581 * Generic version of the affinity autoselector.
582 */
583int irq_setup_affinity(struct irq_desc *desc)
584{
585 struct cpumask *set = irq_default_affinity;
586 int ret, node = irq_desc_get_node(desc);
587 static DEFINE_RAW_SPINLOCK(mask_lock);
588 static struct cpumask mask;
589
590 /* Excludes PER_CPU and NO_BALANCE interrupts */
591 if (!__irq_can_set_affinity(desc))
592 return 0;
593
594 raw_spin_lock(&mask_lock);
595 /*
596 * Preserve the managed affinity setting and a userspace affinity
597 * setup, but make sure that one of the targets is online.
598 */
599 if (irqd_affinity_is_managed(&desc->irq_data) ||
600 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
601 if (cpumask_intersects(desc->irq_common_data.affinity,
602 cpu_online_mask))
603 set = desc->irq_common_data.affinity;
604 else
605 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
606 }
607
608 cpumask_and(&mask, cpu_online_mask, set);
609 if (cpumask_empty(&mask))
610 cpumask_copy(&mask, cpu_online_mask);
611
612 if (node != NUMA_NO_NODE) {
613 const struct cpumask *nodemask = cpumask_of_node(node);
614
615 /* make sure at least one of the cpus in nodemask is online */
616 if (cpumask_intersects(&mask, nodemask))
617 cpumask_and(&mask, &mask, nodemask);
618 }
619 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
620 raw_spin_unlock(&mask_lock);
621 return ret;
622}
623#else
624/* Wrapper for ALPHA specific affinity selector magic */
625int irq_setup_affinity(struct irq_desc *desc)
626{
627 return irq_select_affinity(irq_desc_get_irq(desc));
628}
629#endif /* CONFIG_AUTO_IRQ_AFFINITY */
630#endif /* CONFIG_SMP */
631
632
633/**
634 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
635 * @irq: interrupt number to set affinity
636 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
637 * specific data for percpu_devid interrupts
638 *
639 * This function uses the vCPU specific data to set the vCPU
640 * affinity for an irq. The vCPU specific data is passed from
641 * outside, such as KVM. One example code path is as below:
642 * KVM -> IOMMU -> irq_set_vcpu_affinity().
643 */
644int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
645{
646 unsigned long flags;
647 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
648 struct irq_data *data;
649 struct irq_chip *chip;
650 int ret = -ENOSYS;
651
652 if (!desc)
653 return -EINVAL;
654
655 data = irq_desc_get_irq_data(desc);
656 do {
657 chip = irq_data_get_irq_chip(data);
658 if (chip && chip->irq_set_vcpu_affinity)
659 break;
660#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
661 data = data->parent_data;
662#else
663 data = NULL;
664#endif
665 } while (data);
666
667 if (data)
668 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
669 irq_put_desc_unlock(desc, flags);
670
671 return ret;
672}
673EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
674
675void __disable_irq(struct irq_desc *desc)
676{
677 if (!desc->depth++)
678 irq_disable(desc);
679}
680
681static int __disable_irq_nosync(unsigned int irq)
682{
683 unsigned long flags;
684 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
685
686 if (!desc)
687 return -EINVAL;
688 __disable_irq(desc);
689 irq_put_desc_busunlock(desc, flags);
690 return 0;
691}
692
693/**
694 * disable_irq_nosync - disable an irq without waiting
695 * @irq: Interrupt to disable
696 *
697 * Disable the selected interrupt line. Disables and Enables are
698 * nested.
699 * Unlike disable_irq(), this function does not ensure existing
700 * instances of the IRQ handler have completed before returning.
701 *
702 * This function may be called from IRQ context.
703 */
704void disable_irq_nosync(unsigned int irq)
705{
706 __disable_irq_nosync(irq);
707}
708EXPORT_SYMBOL(disable_irq_nosync);
709
710/**
711 * disable_irq - disable an irq and wait for completion
712 * @irq: Interrupt to disable
713 *
714 * Disable the selected interrupt line. Enables and Disables are
715 * nested.
716 * This function waits for any pending IRQ handlers for this interrupt
717 * to complete before returning. If you use this function while
718 * holding a resource the IRQ handler may need you will deadlock.
719 *
720 * This function may be called - with care - from IRQ context.
721 */
722void disable_irq(unsigned int irq)
723{
724 if (!__disable_irq_nosync(irq))
725 synchronize_irq(irq);
726}
727EXPORT_SYMBOL(disable_irq);
728
729/**
730 * disable_hardirq - disables an irq and waits for hardirq completion
731 * @irq: Interrupt to disable
732 *
733 * Disable the selected interrupt line. Enables and Disables are
734 * nested.
735 * This function waits for any pending hard IRQ handlers for this
736 * interrupt to complete before returning. If you use this function while
737 * holding a resource the hard IRQ handler may need you will deadlock.
738 *
739 * When used to optimistically disable an interrupt from atomic context
740 * the return value must be checked.
741 *
742 * Returns: false if a threaded handler is active.
743 *
744 * This function may be called - with care - from IRQ context.
745 */
746bool disable_hardirq(unsigned int irq)
747{
748 if (!__disable_irq_nosync(irq))
749 return synchronize_hardirq(irq);
750
751 return false;
752}
753EXPORT_SYMBOL_GPL(disable_hardirq);
754
755/**
756 * disable_nmi_nosync - disable an nmi without waiting
757 * @irq: Interrupt to disable
758 *
759 * Disable the selected interrupt line. Disables and enables are
760 * nested.
761 * The interrupt to disable must have been requested through request_nmi.
762 * Unlike disable_nmi(), this function does not ensure existing
763 * instances of the IRQ handler have completed before returning.
764 */
765void disable_nmi_nosync(unsigned int irq)
766{
767 disable_irq_nosync(irq);
768}
769
770void __enable_irq(struct irq_desc *desc)
771{
772 switch (desc->depth) {
773 case 0:
774 err_out:
775 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
776 irq_desc_get_irq(desc));
777 break;
778 case 1: {
779 if (desc->istate & IRQS_SUSPENDED)
780 goto err_out;
781 /* Prevent probing on this irq: */
782 irq_settings_set_noprobe(desc);
783 /*
784 * Call irq_startup() not irq_enable() here because the
785 * interrupt might be marked NOAUTOEN. So irq_startup()
786 * needs to be invoked when it gets enabled the first
787 * time. If it was already started up, then irq_startup()
788 * will invoke irq_enable() under the hood.
789 */
790 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
791 break;
792 }
793 default:
794 desc->depth--;
795 }
796}
797
798/**
799 * enable_irq - enable handling of an irq
800 * @irq: Interrupt to enable
801 *
802 * Undoes the effect of one call to disable_irq(). If this
803 * matches the last disable, processing of interrupts on this
804 * IRQ line is re-enabled.
805 *
806 * This function may be called from IRQ context only when
807 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
808 */
809void enable_irq(unsigned int irq)
810{
811 unsigned long flags;
812 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
813
814 if (!desc)
815 return;
816 if (WARN(!desc->irq_data.chip,
817 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
818 goto out;
819
820 __enable_irq(desc);
821out:
822 irq_put_desc_busunlock(desc, flags);
823}
824EXPORT_SYMBOL(enable_irq);
825
826/**
827 * enable_nmi - enable handling of an nmi
828 * @irq: Interrupt to enable
829 *
830 * The interrupt to enable must have been requested through request_nmi.
831 * Undoes the effect of one call to disable_nmi(). If this
832 * matches the last disable, processing of interrupts on this
833 * IRQ line is re-enabled.
834 */
835void enable_nmi(unsigned int irq)
836{
837 enable_irq(irq);
838}
839
840static int set_irq_wake_real(unsigned int irq, unsigned int on)
841{
842 struct irq_desc *desc = irq_to_desc(irq);
843 int ret = -ENXIO;
844
845 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
846 return 0;
847
848 if (desc->irq_data.chip->irq_set_wake)
849 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
850
851 return ret;
852}
853
854/**
855 * irq_set_irq_wake - control irq power management wakeup
856 * @irq: interrupt to control
857 * @on: enable/disable power management wakeup
858 *
859 * Enable/disable power management wakeup mode, which is
860 * disabled by default. Enables and disables must match,
861 * just as they match for non-wakeup mode support.
862 *
863 * Wakeup mode lets this IRQ wake the system from sleep
864 * states like "suspend to RAM".
865 *
866 * Note: irq enable/disable state is completely orthogonal
867 * to the enable/disable state of irq wake. An irq can be
868 * disabled with disable_irq() and still wake the system as
869 * long as the irq has wake enabled. If this does not hold,
870 * then the underlying irq chip and the related driver need
871 * to be investigated.
872 */
873int irq_set_irq_wake(unsigned int irq, unsigned int on)
874{
875 unsigned long flags;
876 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
877 int ret = 0;
878
879 if (!desc)
880 return -EINVAL;
881
882 /* Don't use NMIs as wake up interrupts please */
883 if (desc->istate & IRQS_NMI) {
884 ret = -EINVAL;
885 goto out_unlock;
886 }
887
888 /* wakeup-capable irqs can be shared between drivers that
889 * don't need to have the same sleep mode behaviors.
890 */
891 if (on) {
892 if (desc->wake_depth++ == 0) {
893 ret = set_irq_wake_real(irq, on);
894 if (ret)
895 desc->wake_depth = 0;
896 else
897 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
898 }
899 } else {
900 if (desc->wake_depth == 0) {
901 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
902 } else if (--desc->wake_depth == 0) {
903 ret = set_irq_wake_real(irq, on);
904 if (ret)
905 desc->wake_depth = 1;
906 else
907 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
908 }
909 }
910
911out_unlock:
912 irq_put_desc_busunlock(desc, flags);
913 return ret;
914}
915EXPORT_SYMBOL(irq_set_irq_wake);
916
917/*
918 * Internal function that tells the architecture code whether a
919 * particular irq has been exclusively allocated or is available
920 * for driver use.
921 */
922int can_request_irq(unsigned int irq, unsigned long irqflags)
923{
924 unsigned long flags;
925 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
926 int canrequest = 0;
927
928 if (!desc)
929 return 0;
930
931 if (irq_settings_can_request(desc)) {
932 if (!desc->action ||
933 irqflags & desc->action->flags & IRQF_SHARED)
934 canrequest = 1;
935 }
936 irq_put_desc_unlock(desc, flags);
937 return canrequest;
938}
939
940int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
941{
942 struct irq_chip *chip = desc->irq_data.chip;
943 int ret, unmask = 0;
944
945 if (!chip || !chip->irq_set_type) {
946 /*
947 * IRQF_TRIGGER_* but the PIC does not support multiple
948 * flow-types?
949 */
950 pr_debug("No set_type function for IRQ %d (%s)\n",
951 irq_desc_get_irq(desc),
952 chip ? (chip->name ? : "unknown") : "unknown");
953 return 0;
954 }
955
956 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
957 if (!irqd_irq_masked(&desc->irq_data))
958 mask_irq(desc);
959 if (!irqd_irq_disabled(&desc->irq_data))
960 unmask = 1;
961 }
962
963 /* Mask all flags except trigger mode */
964 flags &= IRQ_TYPE_SENSE_MASK;
965 ret = chip->irq_set_type(&desc->irq_data, flags);
966
967 switch (ret) {
968 case IRQ_SET_MASK_OK:
969 case IRQ_SET_MASK_OK_DONE:
970 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
971 irqd_set(&desc->irq_data, flags);
972 fallthrough;
973
974 case IRQ_SET_MASK_OK_NOCOPY:
975 flags = irqd_get_trigger_type(&desc->irq_data);
976 irq_settings_set_trigger_mask(desc, flags);
977 irqd_clear(&desc->irq_data, IRQD_LEVEL);
978 irq_settings_clr_level(desc);
979 if (flags & IRQ_TYPE_LEVEL_MASK) {
980 irq_settings_set_level(desc);
981 irqd_set(&desc->irq_data, IRQD_LEVEL);
982 }
983
984 ret = 0;
985 break;
986 default:
987 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
988 flags, irq_desc_get_irq(desc), chip->irq_set_type);
989 }
990 if (unmask)
991 unmask_irq(desc);
992 return ret;
993}
994
995#ifdef CONFIG_HARDIRQS_SW_RESEND
996int irq_set_parent(int irq, int parent_irq)
997{
998 unsigned long flags;
999 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1000
1001 if (!desc)
1002 return -EINVAL;
1003
1004 desc->parent_irq = parent_irq;
1005
1006 irq_put_desc_unlock(desc, flags);
1007 return 0;
1008}
1009EXPORT_SYMBOL_GPL(irq_set_parent);
1010#endif
1011
1012/*
1013 * Default primary interrupt handler for threaded interrupts. Is
1014 * assigned as primary handler when request_threaded_irq is called
1015 * with handler == NULL. Useful for oneshot interrupts.
1016 */
1017static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1018{
1019 return IRQ_WAKE_THREAD;
1020}
1021
1022/*
1023 * Primary handler for nested threaded interrupts. Should never be
1024 * called.
1025 */
1026static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1027{
1028 WARN(1, "Primary handler called for nested irq %d\n", irq);
1029 return IRQ_NONE;
1030}
1031
1032static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1033{
1034 WARN(1, "Secondary action handler called for irq %d\n", irq);
1035 return IRQ_NONE;
1036}
1037
1038static int irq_wait_for_interrupt(struct irqaction *action)
1039{
1040 for (;;) {
1041 set_current_state(TASK_INTERRUPTIBLE);
1042
1043 if (kthread_should_stop()) {
1044 /* may need to run one last time */
1045 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1046 &action->thread_flags)) {
1047 __set_current_state(TASK_RUNNING);
1048 return 0;
1049 }
1050 __set_current_state(TASK_RUNNING);
1051 return -1;
1052 }
1053
1054 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1055 &action->thread_flags)) {
1056 __set_current_state(TASK_RUNNING);
1057 return 0;
1058 }
1059 schedule();
1060 }
1061}
1062
1063/*
1064 * Oneshot interrupts keep the irq line masked until the threaded
1065 * handler finished. unmask if the interrupt has not been disabled and
1066 * is marked MASKED.
1067 */
1068static void irq_finalize_oneshot(struct irq_desc *desc,
1069 struct irqaction *action)
1070{
1071 if (!(desc->istate & IRQS_ONESHOT) ||
1072 action->handler == irq_forced_secondary_handler)
1073 return;
1074again:
1075 chip_bus_lock(desc);
1076 raw_spin_lock_irq(&desc->lock);
1077
1078 /*
1079 * Implausible though it may be we need to protect us against
1080 * the following scenario:
1081 *
1082 * The thread is faster done than the hard interrupt handler
1083 * on the other CPU. If we unmask the irq line then the
1084 * interrupt can come in again and masks the line, leaves due
1085 * to IRQS_INPROGRESS and the irq line is masked forever.
1086 *
1087 * This also serializes the state of shared oneshot handlers
1088 * versus "desc->threads_oneshot |= action->thread_mask;" in
1089 * irq_wake_thread(). See the comment there which explains the
1090 * serialization.
1091 */
1092 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1093 raw_spin_unlock_irq(&desc->lock);
1094 chip_bus_sync_unlock(desc);
1095 cpu_relax();
1096 goto again;
1097 }
1098
1099 /*
1100 * Now check again, whether the thread should run. Otherwise
1101 * we would clear the threads_oneshot bit of this thread which
1102 * was just set.
1103 */
1104 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1105 goto out_unlock;
1106
1107 desc->threads_oneshot &= ~action->thread_mask;
1108
1109 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1110 irqd_irq_masked(&desc->irq_data))
1111 unmask_threaded_irq(desc);
1112
1113out_unlock:
1114 raw_spin_unlock_irq(&desc->lock);
1115 chip_bus_sync_unlock(desc);
1116}
1117
1118#ifdef CONFIG_SMP
1119/*
1120 * Check whether we need to change the affinity of the interrupt thread.
1121 */
1122static void
1123irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1124{
1125 cpumask_var_t mask;
1126 bool valid = true;
1127
1128 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1129 return;
1130
1131 /*
1132 * In case we are out of memory we set IRQTF_AFFINITY again and
1133 * try again next time
1134 */
1135 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1136 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1137 return;
1138 }
1139
1140 raw_spin_lock_irq(&desc->lock);
1141 /*
1142 * This code is triggered unconditionally. Check the affinity
1143 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1144 */
1145 if (cpumask_available(desc->irq_common_data.affinity)) {
1146 const struct cpumask *m;
1147
1148 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1149 cpumask_copy(mask, m);
1150 } else {
1151 valid = false;
1152 }
1153 raw_spin_unlock_irq(&desc->lock);
1154
1155 if (valid)
1156 set_cpus_allowed_ptr(current, mask);
1157 free_cpumask_var(mask);
1158}
1159#else
1160static inline void
1161irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1162#endif
1163
1164/*
1165 * Interrupts which are not explicitly requested as threaded
1166 * interrupts rely on the implicit bh/preempt disable of the hard irq
1167 * context. So we need to disable bh here to avoid deadlocks and other
1168 * side effects.
1169 */
1170static irqreturn_t
1171irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1172{
1173 irqreturn_t ret;
1174
1175 local_bh_disable();
1176 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1177 local_irq_disable();
1178 ret = action->thread_fn(action->irq, action->dev_id);
1179 if (ret == IRQ_HANDLED)
1180 atomic_inc(&desc->threads_handled);
1181
1182 irq_finalize_oneshot(desc, action);
1183 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1184 local_irq_enable();
1185 local_bh_enable();
1186 return ret;
1187}
1188
1189/*
1190 * Interrupts explicitly requested as threaded interrupts want to be
1191 * preemptible - many of them need to sleep and wait for slow busses to
1192 * complete.
1193 */
1194static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1195 struct irqaction *action)
1196{
1197 irqreturn_t ret;
1198
1199 ret = action->thread_fn(action->irq, action->dev_id);
1200 if (ret == IRQ_HANDLED)
1201 atomic_inc(&desc->threads_handled);
1202
1203 irq_finalize_oneshot(desc, action);
1204 return ret;
1205}
1206
1207static void wake_threads_waitq(struct irq_desc *desc)
1208{
1209 if (atomic_dec_and_test(&desc->threads_active))
1210 wake_up(&desc->wait_for_threads);
1211}
1212
1213static void irq_thread_dtor(struct callback_head *unused)
1214{
1215 struct task_struct *tsk = current;
1216 struct irq_desc *desc;
1217 struct irqaction *action;
1218
1219 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1220 return;
1221
1222 action = kthread_data(tsk);
1223
1224 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1225 tsk->comm, tsk->pid, action->irq);
1226
1227
1228 desc = irq_to_desc(action->irq);
1229 /*
1230 * If IRQTF_RUNTHREAD is set, we need to decrement
1231 * desc->threads_active and wake possible waiters.
1232 */
1233 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1234 wake_threads_waitq(desc);
1235
1236 /* Prevent a stale desc->threads_oneshot */
1237 irq_finalize_oneshot(desc, action);
1238}
1239
1240static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1241{
1242 struct irqaction *secondary = action->secondary;
1243
1244 if (WARN_ON_ONCE(!secondary))
1245 return;
1246
1247 raw_spin_lock_irq(&desc->lock);
1248 __irq_wake_thread(desc, secondary);
1249 raw_spin_unlock_irq(&desc->lock);
1250}
1251
1252/*
1253 * Interrupt handler thread
1254 */
1255static int irq_thread(void *data)
1256{
1257 struct callback_head on_exit_work;
1258 struct irqaction *action = data;
1259 struct irq_desc *desc = irq_to_desc(action->irq);
1260 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1261 struct irqaction *action);
1262
1263 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1264 &action->thread_flags))
1265 handler_fn = irq_forced_thread_fn;
1266 else
1267 handler_fn = irq_thread_fn;
1268
1269 init_task_work(&on_exit_work, irq_thread_dtor);
1270 task_work_add(current, &on_exit_work, TWA_NONE);
1271
1272 irq_thread_check_affinity(desc, action);
1273
1274 while (!irq_wait_for_interrupt(action)) {
1275 irqreturn_t action_ret;
1276
1277 irq_thread_check_affinity(desc, action);
1278
1279 action_ret = handler_fn(desc, action);
1280 if (action_ret == IRQ_WAKE_THREAD)
1281 irq_wake_secondary(desc, action);
1282
1283 wake_threads_waitq(desc);
1284 }
1285
1286 /*
1287 * This is the regular exit path. __free_irq() is stopping the
1288 * thread via kthread_stop() after calling
1289 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1290 * oneshot mask bit can be set.
1291 */
1292 task_work_cancel(current, irq_thread_dtor);
1293 return 0;
1294}
1295
1296/**
1297 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1298 * @irq: Interrupt line
1299 * @dev_id: Device identity for which the thread should be woken
1300 *
1301 */
1302void irq_wake_thread(unsigned int irq, void *dev_id)
1303{
1304 struct irq_desc *desc = irq_to_desc(irq);
1305 struct irqaction *action;
1306 unsigned long flags;
1307
1308 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1309 return;
1310
1311 raw_spin_lock_irqsave(&desc->lock, flags);
1312 for_each_action_of_desc(desc, action) {
1313 if (action->dev_id == dev_id) {
1314 if (action->thread)
1315 __irq_wake_thread(desc, action);
1316 break;
1317 }
1318 }
1319 raw_spin_unlock_irqrestore(&desc->lock, flags);
1320}
1321EXPORT_SYMBOL_GPL(irq_wake_thread);
1322
1323static int irq_setup_forced_threading(struct irqaction *new)
1324{
1325 if (!force_irqthreads)
1326 return 0;
1327 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1328 return 0;
1329
1330 /*
1331 * No further action required for interrupts which are requested as
1332 * threaded interrupts already
1333 */
1334 if (new->handler == irq_default_primary_handler)
1335 return 0;
1336
1337 new->flags |= IRQF_ONESHOT;
1338
1339 /*
1340 * Handle the case where we have a real primary handler and a
1341 * thread handler. We force thread them as well by creating a
1342 * secondary action.
1343 */
1344 if (new->handler && new->thread_fn) {
1345 /* Allocate the secondary action */
1346 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1347 if (!new->secondary)
1348 return -ENOMEM;
1349 new->secondary->handler = irq_forced_secondary_handler;
1350 new->secondary->thread_fn = new->thread_fn;
1351 new->secondary->dev_id = new->dev_id;
1352 new->secondary->irq = new->irq;
1353 new->secondary->name = new->name;
1354 }
1355 /* Deal with the primary handler */
1356 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1357 new->thread_fn = new->handler;
1358 new->handler = irq_default_primary_handler;
1359 return 0;
1360}
1361
1362static int irq_request_resources(struct irq_desc *desc)
1363{
1364 struct irq_data *d = &desc->irq_data;
1365 struct irq_chip *c = d->chip;
1366
1367 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1368}
1369
1370static void irq_release_resources(struct irq_desc *desc)
1371{
1372 struct irq_data *d = &desc->irq_data;
1373 struct irq_chip *c = d->chip;
1374
1375 if (c->irq_release_resources)
1376 c->irq_release_resources(d);
1377}
1378
1379static bool irq_supports_nmi(struct irq_desc *desc)
1380{
1381 struct irq_data *d = irq_desc_get_irq_data(desc);
1382
1383#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1384 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1385 if (d->parent_data)
1386 return false;
1387#endif
1388 /* Don't support NMIs for chips behind a slow bus */
1389 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1390 return false;
1391
1392 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1393}
1394
1395static int irq_nmi_setup(struct irq_desc *desc)
1396{
1397 struct irq_data *d = irq_desc_get_irq_data(desc);
1398 struct irq_chip *c = d->chip;
1399
1400 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1401}
1402
1403static void irq_nmi_teardown(struct irq_desc *desc)
1404{
1405 struct irq_data *d = irq_desc_get_irq_data(desc);
1406 struct irq_chip *c = d->chip;
1407
1408 if (c->irq_nmi_teardown)
1409 c->irq_nmi_teardown(d);
1410}
1411
1412static int
1413setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1414{
1415 struct task_struct *t;
1416
1417 if (!secondary) {
1418 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1419 new->name);
1420 } else {
1421 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1422 new->name);
1423 }
1424
1425 if (IS_ERR(t))
1426 return PTR_ERR(t);
1427
1428 sched_set_fifo(t);
1429
1430 /*
1431 * We keep the reference to the task struct even if
1432 * the thread dies to avoid that the interrupt code
1433 * references an already freed task_struct.
1434 */
1435 new->thread = get_task_struct(t);
1436 /*
1437 * Tell the thread to set its affinity. This is
1438 * important for shared interrupt handlers as we do
1439 * not invoke setup_affinity() for the secondary
1440 * handlers as everything is already set up. Even for
1441 * interrupts marked with IRQF_NO_BALANCE this is
1442 * correct as we want the thread to move to the cpu(s)
1443 * on which the requesting code placed the interrupt.
1444 */
1445 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1446 return 0;
1447}
1448
1449/*
1450 * Internal function to register an irqaction - typically used to
1451 * allocate special interrupts that are part of the architecture.
1452 *
1453 * Locking rules:
1454 *
1455 * desc->request_mutex Provides serialization against a concurrent free_irq()
1456 * chip_bus_lock Provides serialization for slow bus operations
1457 * desc->lock Provides serialization against hard interrupts
1458 *
1459 * chip_bus_lock and desc->lock are sufficient for all other management and
1460 * interrupt related functions. desc->request_mutex solely serializes
1461 * request/free_irq().
1462 */
1463static int
1464__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1465{
1466 struct irqaction *old, **old_ptr;
1467 unsigned long flags, thread_mask = 0;
1468 int ret, nested, shared = 0;
1469
1470 if (!desc)
1471 return -EINVAL;
1472
1473 if (desc->irq_data.chip == &no_irq_chip)
1474 return -ENOSYS;
1475 if (!try_module_get(desc->owner))
1476 return -ENODEV;
1477
1478 new->irq = irq;
1479
1480 /*
1481 * If the trigger type is not specified by the caller,
1482 * then use the default for this interrupt.
1483 */
1484 if (!(new->flags & IRQF_TRIGGER_MASK))
1485 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1486
1487 /*
1488 * Check whether the interrupt nests into another interrupt
1489 * thread.
1490 */
1491 nested = irq_settings_is_nested_thread(desc);
1492 if (nested) {
1493 if (!new->thread_fn) {
1494 ret = -EINVAL;
1495 goto out_mput;
1496 }
1497 /*
1498 * Replace the primary handler which was provided from
1499 * the driver for non nested interrupt handling by the
1500 * dummy function which warns when called.
1501 */
1502 new->handler = irq_nested_primary_handler;
1503 } else {
1504 if (irq_settings_can_thread(desc)) {
1505 ret = irq_setup_forced_threading(new);
1506 if (ret)
1507 goto out_mput;
1508 }
1509 }
1510
1511 /*
1512 * Create a handler thread when a thread function is supplied
1513 * and the interrupt does not nest into another interrupt
1514 * thread.
1515 */
1516 if (new->thread_fn && !nested) {
1517 ret = setup_irq_thread(new, irq, false);
1518 if (ret)
1519 goto out_mput;
1520 if (new->secondary) {
1521 ret = setup_irq_thread(new->secondary, irq, true);
1522 if (ret)
1523 goto out_thread;
1524 }
1525 }
1526
1527 /*
1528 * Drivers are often written to work w/o knowledge about the
1529 * underlying irq chip implementation, so a request for a
1530 * threaded irq without a primary hard irq context handler
1531 * requires the ONESHOT flag to be set. Some irq chips like
1532 * MSI based interrupts are per se one shot safe. Check the
1533 * chip flags, so we can avoid the unmask dance at the end of
1534 * the threaded handler for those.
1535 */
1536 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1537 new->flags &= ~IRQF_ONESHOT;
1538
1539 /*
1540 * Protects against a concurrent __free_irq() call which might wait
1541 * for synchronize_hardirq() to complete without holding the optional
1542 * chip bus lock and desc->lock. Also protects against handing out
1543 * a recycled oneshot thread_mask bit while it's still in use by
1544 * its previous owner.
1545 */
1546 mutex_lock(&desc->request_mutex);
1547
1548 /*
1549 * Acquire bus lock as the irq_request_resources() callback below
1550 * might rely on the serialization or the magic power management
1551 * functions which are abusing the irq_bus_lock() callback,
1552 */
1553 chip_bus_lock(desc);
1554
1555 /* First installed action requests resources. */
1556 if (!desc->action) {
1557 ret = irq_request_resources(desc);
1558 if (ret) {
1559 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1560 new->name, irq, desc->irq_data.chip->name);
1561 goto out_bus_unlock;
1562 }
1563 }
1564
1565 /*
1566 * The following block of code has to be executed atomically
1567 * protected against a concurrent interrupt and any of the other
1568 * management calls which are not serialized via
1569 * desc->request_mutex or the optional bus lock.
1570 */
1571 raw_spin_lock_irqsave(&desc->lock, flags);
1572 old_ptr = &desc->action;
1573 old = *old_ptr;
1574 if (old) {
1575 /*
1576 * Can't share interrupts unless both agree to and are
1577 * the same type (level, edge, polarity). So both flag
1578 * fields must have IRQF_SHARED set and the bits which
1579 * set the trigger type must match. Also all must
1580 * agree on ONESHOT.
1581 * Interrupt lines used for NMIs cannot be shared.
1582 */
1583 unsigned int oldtype;
1584
1585 if (desc->istate & IRQS_NMI) {
1586 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1587 new->name, irq, desc->irq_data.chip->name);
1588 ret = -EINVAL;
1589 goto out_unlock;
1590 }
1591
1592 /*
1593 * If nobody did set the configuration before, inherit
1594 * the one provided by the requester.
1595 */
1596 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1597 oldtype = irqd_get_trigger_type(&desc->irq_data);
1598 } else {
1599 oldtype = new->flags & IRQF_TRIGGER_MASK;
1600 irqd_set_trigger_type(&desc->irq_data, oldtype);
1601 }
1602
1603 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1604 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1605 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1606 goto mismatch;
1607
1608 /* All handlers must agree on per-cpuness */
1609 if ((old->flags & IRQF_PERCPU) !=
1610 (new->flags & IRQF_PERCPU))
1611 goto mismatch;
1612
1613 /* add new interrupt at end of irq queue */
1614 do {
1615 /*
1616 * Or all existing action->thread_mask bits,
1617 * so we can find the next zero bit for this
1618 * new action.
1619 */
1620 thread_mask |= old->thread_mask;
1621 old_ptr = &old->next;
1622 old = *old_ptr;
1623 } while (old);
1624 shared = 1;
1625 }
1626
1627 /*
1628 * Setup the thread mask for this irqaction for ONESHOT. For
1629 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1630 * conditional in irq_wake_thread().
1631 */
1632 if (new->flags & IRQF_ONESHOT) {
1633 /*
1634 * Unlikely to have 32 resp 64 irqs sharing one line,
1635 * but who knows.
1636 */
1637 if (thread_mask == ~0UL) {
1638 ret = -EBUSY;
1639 goto out_unlock;
1640 }
1641 /*
1642 * The thread_mask for the action is or'ed to
1643 * desc->thread_active to indicate that the
1644 * IRQF_ONESHOT thread handler has been woken, but not
1645 * yet finished. The bit is cleared when a thread
1646 * completes. When all threads of a shared interrupt
1647 * line have completed desc->threads_active becomes
1648 * zero and the interrupt line is unmasked. See
1649 * handle.c:irq_wake_thread() for further information.
1650 *
1651 * If no thread is woken by primary (hard irq context)
1652 * interrupt handlers, then desc->threads_active is
1653 * also checked for zero to unmask the irq line in the
1654 * affected hard irq flow handlers
1655 * (handle_[fasteoi|level]_irq).
1656 *
1657 * The new action gets the first zero bit of
1658 * thread_mask assigned. See the loop above which or's
1659 * all existing action->thread_mask bits.
1660 */
1661 new->thread_mask = 1UL << ffz(thread_mask);
1662
1663 } else if (new->handler == irq_default_primary_handler &&
1664 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1665 /*
1666 * The interrupt was requested with handler = NULL, so
1667 * we use the default primary handler for it. But it
1668 * does not have the oneshot flag set. In combination
1669 * with level interrupts this is deadly, because the
1670 * default primary handler just wakes the thread, then
1671 * the irq lines is reenabled, but the device still
1672 * has the level irq asserted. Rinse and repeat....
1673 *
1674 * While this works for edge type interrupts, we play
1675 * it safe and reject unconditionally because we can't
1676 * say for sure which type this interrupt really
1677 * has. The type flags are unreliable as the
1678 * underlying chip implementation can override them.
1679 */
1680 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1681 new->name, irq);
1682 ret = -EINVAL;
1683 goto out_unlock;
1684 }
1685
1686 if (!shared) {
1687 init_waitqueue_head(&desc->wait_for_threads);
1688
1689 /* Setup the type (level, edge polarity) if configured: */
1690 if (new->flags & IRQF_TRIGGER_MASK) {
1691 ret = __irq_set_trigger(desc,
1692 new->flags & IRQF_TRIGGER_MASK);
1693
1694 if (ret)
1695 goto out_unlock;
1696 }
1697
1698 /*
1699 * Activate the interrupt. That activation must happen
1700 * independently of IRQ_NOAUTOEN. request_irq() can fail
1701 * and the callers are supposed to handle
1702 * that. enable_irq() of an interrupt requested with
1703 * IRQ_NOAUTOEN is not supposed to fail. The activation
1704 * keeps it in shutdown mode, it merily associates
1705 * resources if necessary and if that's not possible it
1706 * fails. Interrupts which are in managed shutdown mode
1707 * will simply ignore that activation request.
1708 */
1709 ret = irq_activate(desc);
1710 if (ret)
1711 goto out_unlock;
1712
1713 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1714 IRQS_ONESHOT | IRQS_WAITING);
1715 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1716
1717 if (new->flags & IRQF_PERCPU) {
1718 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1719 irq_settings_set_per_cpu(desc);
1720 if (new->flags & IRQF_NO_DEBUG)
1721 irq_settings_set_no_debug(desc);
1722 }
1723
1724 if (noirqdebug)
1725 irq_settings_set_no_debug(desc);
1726
1727 if (new->flags & IRQF_ONESHOT)
1728 desc->istate |= IRQS_ONESHOT;
1729
1730 /* Exclude IRQ from balancing if requested */
1731 if (new->flags & IRQF_NOBALANCING) {
1732 irq_settings_set_no_balancing(desc);
1733 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1734 }
1735
1736 if (!(new->flags & IRQF_NO_AUTOEN) &&
1737 irq_settings_can_autoenable(desc)) {
1738 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1739 } else {
1740 /*
1741 * Shared interrupts do not go well with disabling
1742 * auto enable. The sharing interrupt might request
1743 * it while it's still disabled and then wait for
1744 * interrupts forever.
1745 */
1746 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1747 /* Undo nested disables: */
1748 desc->depth = 1;
1749 }
1750
1751 } else if (new->flags & IRQF_TRIGGER_MASK) {
1752 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1753 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1754
1755 if (nmsk != omsk)
1756 /* hope the handler works with current trigger mode */
1757 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1758 irq, omsk, nmsk);
1759 }
1760
1761 *old_ptr = new;
1762
1763 irq_pm_install_action(desc, new);
1764
1765 /* Reset broken irq detection when installing new handler */
1766 desc->irq_count = 0;
1767 desc->irqs_unhandled = 0;
1768
1769 /*
1770 * Check whether we disabled the irq via the spurious handler
1771 * before. Reenable it and give it another chance.
1772 */
1773 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1774 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1775 __enable_irq(desc);
1776 }
1777
1778 raw_spin_unlock_irqrestore(&desc->lock, flags);
1779 chip_bus_sync_unlock(desc);
1780 mutex_unlock(&desc->request_mutex);
1781
1782 irq_setup_timings(desc, new);
1783
1784 /*
1785 * Strictly no need to wake it up, but hung_task complains
1786 * when no hard interrupt wakes the thread up.
1787 */
1788 if (new->thread)
1789 wake_up_process(new->thread);
1790 if (new->secondary)
1791 wake_up_process(new->secondary->thread);
1792
1793 register_irq_proc(irq, desc);
1794 new->dir = NULL;
1795 register_handler_proc(irq, new);
1796 return 0;
1797
1798mismatch:
1799 if (!(new->flags & IRQF_PROBE_SHARED)) {
1800 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1801 irq, new->flags, new->name, old->flags, old->name);
1802#ifdef CONFIG_DEBUG_SHIRQ
1803 dump_stack();
1804#endif
1805 }
1806 ret = -EBUSY;
1807
1808out_unlock:
1809 raw_spin_unlock_irqrestore(&desc->lock, flags);
1810
1811 if (!desc->action)
1812 irq_release_resources(desc);
1813out_bus_unlock:
1814 chip_bus_sync_unlock(desc);
1815 mutex_unlock(&desc->request_mutex);
1816
1817out_thread:
1818 if (new->thread) {
1819 struct task_struct *t = new->thread;
1820
1821 new->thread = NULL;
1822 kthread_stop(t);
1823 put_task_struct(t);
1824 }
1825 if (new->secondary && new->secondary->thread) {
1826 struct task_struct *t = new->secondary->thread;
1827
1828 new->secondary->thread = NULL;
1829 kthread_stop(t);
1830 put_task_struct(t);
1831 }
1832out_mput:
1833 module_put(desc->owner);
1834 return ret;
1835}
1836
1837/*
1838 * Internal function to unregister an irqaction - used to free
1839 * regular and special interrupts that are part of the architecture.
1840 */
1841static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1842{
1843 unsigned irq = desc->irq_data.irq;
1844 struct irqaction *action, **action_ptr;
1845 unsigned long flags;
1846
1847 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1848
1849 mutex_lock(&desc->request_mutex);
1850 chip_bus_lock(desc);
1851 raw_spin_lock_irqsave(&desc->lock, flags);
1852
1853 /*
1854 * There can be multiple actions per IRQ descriptor, find the right
1855 * one based on the dev_id:
1856 */
1857 action_ptr = &desc->action;
1858 for (;;) {
1859 action = *action_ptr;
1860
1861 if (!action) {
1862 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1863 raw_spin_unlock_irqrestore(&desc->lock, flags);
1864 chip_bus_sync_unlock(desc);
1865 mutex_unlock(&desc->request_mutex);
1866 return NULL;
1867 }
1868
1869 if (action->dev_id == dev_id)
1870 break;
1871 action_ptr = &action->next;
1872 }
1873
1874 /* Found it - now remove it from the list of entries: */
1875 *action_ptr = action->next;
1876
1877 irq_pm_remove_action(desc, action);
1878
1879 /* If this was the last handler, shut down the IRQ line: */
1880 if (!desc->action) {
1881 irq_settings_clr_disable_unlazy(desc);
1882 /* Only shutdown. Deactivate after synchronize_hardirq() */
1883 irq_shutdown(desc);
1884 }
1885
1886#ifdef CONFIG_SMP
1887 /* make sure affinity_hint is cleaned up */
1888 if (WARN_ON_ONCE(desc->affinity_hint))
1889 desc->affinity_hint = NULL;
1890#endif
1891
1892 raw_spin_unlock_irqrestore(&desc->lock, flags);
1893 /*
1894 * Drop bus_lock here so the changes which were done in the chip
1895 * callbacks above are synced out to the irq chips which hang
1896 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1897 *
1898 * Aside of that the bus_lock can also be taken from the threaded
1899 * handler in irq_finalize_oneshot() which results in a deadlock
1900 * because kthread_stop() would wait forever for the thread to
1901 * complete, which is blocked on the bus lock.
1902 *
1903 * The still held desc->request_mutex() protects against a
1904 * concurrent request_irq() of this irq so the release of resources
1905 * and timing data is properly serialized.
1906 */
1907 chip_bus_sync_unlock(desc);
1908
1909 unregister_handler_proc(irq, action);
1910
1911 /*
1912 * Make sure it's not being used on another CPU and if the chip
1913 * supports it also make sure that there is no (not yet serviced)
1914 * interrupt in flight at the hardware level.
1915 */
1916 __synchronize_hardirq(desc, true);
1917
1918#ifdef CONFIG_DEBUG_SHIRQ
1919 /*
1920 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1921 * event to happen even now it's being freed, so let's make sure that
1922 * is so by doing an extra call to the handler ....
1923 *
1924 * ( We do this after actually deregistering it, to make sure that a
1925 * 'real' IRQ doesn't run in parallel with our fake. )
1926 */
1927 if (action->flags & IRQF_SHARED) {
1928 local_irq_save(flags);
1929 action->handler(irq, dev_id);
1930 local_irq_restore(flags);
1931 }
1932#endif
1933
1934 /*
1935 * The action has already been removed above, but the thread writes
1936 * its oneshot mask bit when it completes. Though request_mutex is
1937 * held across this which prevents __setup_irq() from handing out
1938 * the same bit to a newly requested action.
1939 */
1940 if (action->thread) {
1941 kthread_stop(action->thread);
1942 put_task_struct(action->thread);
1943 if (action->secondary && action->secondary->thread) {
1944 kthread_stop(action->secondary->thread);
1945 put_task_struct(action->secondary->thread);
1946 }
1947 }
1948
1949 /* Last action releases resources */
1950 if (!desc->action) {
1951 /*
1952 * Reacquire bus lock as irq_release_resources() might
1953 * require it to deallocate resources over the slow bus.
1954 */
1955 chip_bus_lock(desc);
1956 /*
1957 * There is no interrupt on the fly anymore. Deactivate it
1958 * completely.
1959 */
1960 raw_spin_lock_irqsave(&desc->lock, flags);
1961 irq_domain_deactivate_irq(&desc->irq_data);
1962 raw_spin_unlock_irqrestore(&desc->lock, flags);
1963
1964 irq_release_resources(desc);
1965 chip_bus_sync_unlock(desc);
1966 irq_remove_timings(desc);
1967 }
1968
1969 mutex_unlock(&desc->request_mutex);
1970
1971 irq_chip_pm_put(&desc->irq_data);
1972 module_put(desc->owner);
1973 kfree(action->secondary);
1974 return action;
1975}
1976
1977/**
1978 * free_irq - free an interrupt allocated with request_irq
1979 * @irq: Interrupt line to free
1980 * @dev_id: Device identity to free
1981 *
1982 * Remove an interrupt handler. The handler is removed and if the
1983 * interrupt line is no longer in use by any driver it is disabled.
1984 * On a shared IRQ the caller must ensure the interrupt is disabled
1985 * on the card it drives before calling this function. The function
1986 * does not return until any executing interrupts for this IRQ
1987 * have completed.
1988 *
1989 * This function must not be called from interrupt context.
1990 *
1991 * Returns the devname argument passed to request_irq.
1992 */
1993const void *free_irq(unsigned int irq, void *dev_id)
1994{
1995 struct irq_desc *desc = irq_to_desc(irq);
1996 struct irqaction *action;
1997 const char *devname;
1998
1999 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2000 return NULL;
2001
2002#ifdef CONFIG_SMP
2003 if (WARN_ON(desc->affinity_notify))
2004 desc->affinity_notify = NULL;
2005#endif
2006
2007 action = __free_irq(desc, dev_id);
2008
2009 if (!action)
2010 return NULL;
2011
2012 devname = action->name;
2013 kfree(action);
2014 return devname;
2015}
2016EXPORT_SYMBOL(free_irq);
2017
2018/* This function must be called with desc->lock held */
2019static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2020{
2021 const char *devname = NULL;
2022
2023 desc->istate &= ~IRQS_NMI;
2024
2025 if (!WARN_ON(desc->action == NULL)) {
2026 irq_pm_remove_action(desc, desc->action);
2027 devname = desc->action->name;
2028 unregister_handler_proc(irq, desc->action);
2029
2030 kfree(desc->action);
2031 desc->action = NULL;
2032 }
2033
2034 irq_settings_clr_disable_unlazy(desc);
2035 irq_shutdown_and_deactivate(desc);
2036
2037 irq_release_resources(desc);
2038
2039 irq_chip_pm_put(&desc->irq_data);
2040 module_put(desc->owner);
2041
2042 return devname;
2043}
2044
2045const void *free_nmi(unsigned int irq, void *dev_id)
2046{
2047 struct irq_desc *desc = irq_to_desc(irq);
2048 unsigned long flags;
2049 const void *devname;
2050
2051 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2052 return NULL;
2053
2054 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2055 return NULL;
2056
2057 /* NMI still enabled */
2058 if (WARN_ON(desc->depth == 0))
2059 disable_nmi_nosync(irq);
2060
2061 raw_spin_lock_irqsave(&desc->lock, flags);
2062
2063 irq_nmi_teardown(desc);
2064 devname = __cleanup_nmi(irq, desc);
2065
2066 raw_spin_unlock_irqrestore(&desc->lock, flags);
2067
2068 return devname;
2069}
2070
2071/**
2072 * request_threaded_irq - allocate an interrupt line
2073 * @irq: Interrupt line to allocate
2074 * @handler: Function to be called when the IRQ occurs.
2075 * Primary handler for threaded interrupts
2076 * If NULL and thread_fn != NULL the default
2077 * primary handler is installed
2078 * @thread_fn: Function called from the irq handler thread
2079 * If NULL, no irq thread is created
2080 * @irqflags: Interrupt type flags
2081 * @devname: An ascii name for the claiming device
2082 * @dev_id: A cookie passed back to the handler function
2083 *
2084 * This call allocates interrupt resources and enables the
2085 * interrupt line and IRQ handling. From the point this
2086 * call is made your handler function may be invoked. Since
2087 * your handler function must clear any interrupt the board
2088 * raises, you must take care both to initialise your hardware
2089 * and to set up the interrupt handler in the right order.
2090 *
2091 * If you want to set up a threaded irq handler for your device
2092 * then you need to supply @handler and @thread_fn. @handler is
2093 * still called in hard interrupt context and has to check
2094 * whether the interrupt originates from the device. If yes it
2095 * needs to disable the interrupt on the device and return
2096 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2097 * @thread_fn. This split handler design is necessary to support
2098 * shared interrupts.
2099 *
2100 * Dev_id must be globally unique. Normally the address of the
2101 * device data structure is used as the cookie. Since the handler
2102 * receives this value it makes sense to use it.
2103 *
2104 * If your interrupt is shared you must pass a non NULL dev_id
2105 * as this is required when freeing the interrupt.
2106 *
2107 * Flags:
2108 *
2109 * IRQF_SHARED Interrupt is shared
2110 * IRQF_TRIGGER_* Specify active edge(s) or level
2111 *
2112 */
2113int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2114 irq_handler_t thread_fn, unsigned long irqflags,
2115 const char *devname, void *dev_id)
2116{
2117 struct irqaction *action;
2118 struct irq_desc *desc;
2119 int retval;
2120
2121 if (irq == IRQ_NOTCONNECTED)
2122 return -ENOTCONN;
2123
2124 /*
2125 * Sanity-check: shared interrupts must pass in a real dev-ID,
2126 * otherwise we'll have trouble later trying to figure out
2127 * which interrupt is which (messes up the interrupt freeing
2128 * logic etc).
2129 *
2130 * Also shared interrupts do not go well with disabling auto enable.
2131 * The sharing interrupt might request it while it's still disabled
2132 * and then wait for interrupts forever.
2133 *
2134 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2135 * it cannot be set along with IRQF_NO_SUSPEND.
2136 */
2137 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2138 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2139 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2140 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2141 return -EINVAL;
2142
2143 desc = irq_to_desc(irq);
2144 if (!desc)
2145 return -EINVAL;
2146
2147 if (!irq_settings_can_request(desc) ||
2148 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2149 return -EINVAL;
2150
2151 if (!handler) {
2152 if (!thread_fn)
2153 return -EINVAL;
2154 handler = irq_default_primary_handler;
2155 }
2156
2157 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2158 if (!action)
2159 return -ENOMEM;
2160
2161 action->handler = handler;
2162 action->thread_fn = thread_fn;
2163 action->flags = irqflags;
2164 action->name = devname;
2165 action->dev_id = dev_id;
2166
2167 retval = irq_chip_pm_get(&desc->irq_data);
2168 if (retval < 0) {
2169 kfree(action);
2170 return retval;
2171 }
2172
2173 retval = __setup_irq(irq, desc, action);
2174
2175 if (retval) {
2176 irq_chip_pm_put(&desc->irq_data);
2177 kfree(action->secondary);
2178 kfree(action);
2179 }
2180
2181#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2182 if (!retval && (irqflags & IRQF_SHARED)) {
2183 /*
2184 * It's a shared IRQ -- the driver ought to be prepared for it
2185 * to happen immediately, so let's make sure....
2186 * We disable the irq to make sure that a 'real' IRQ doesn't
2187 * run in parallel with our fake.
2188 */
2189 unsigned long flags;
2190
2191 disable_irq(irq);
2192 local_irq_save(flags);
2193
2194 handler(irq, dev_id);
2195
2196 local_irq_restore(flags);
2197 enable_irq(irq);
2198 }
2199#endif
2200 return retval;
2201}
2202EXPORT_SYMBOL(request_threaded_irq);
2203
2204/**
2205 * request_any_context_irq - allocate an interrupt line
2206 * @irq: Interrupt line to allocate
2207 * @handler: Function to be called when the IRQ occurs.
2208 * Threaded handler for threaded interrupts.
2209 * @flags: Interrupt type flags
2210 * @name: An ascii name for the claiming device
2211 * @dev_id: A cookie passed back to the handler function
2212 *
2213 * This call allocates interrupt resources and enables the
2214 * interrupt line and IRQ handling. It selects either a
2215 * hardirq or threaded handling method depending on the
2216 * context.
2217 *
2218 * On failure, it returns a negative value. On success,
2219 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2220 */
2221int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2222 unsigned long flags, const char *name, void *dev_id)
2223{
2224 struct irq_desc *desc;
2225 int ret;
2226
2227 if (irq == IRQ_NOTCONNECTED)
2228 return -ENOTCONN;
2229
2230 desc = irq_to_desc(irq);
2231 if (!desc)
2232 return -EINVAL;
2233
2234 if (irq_settings_is_nested_thread(desc)) {
2235 ret = request_threaded_irq(irq, NULL, handler,
2236 flags, name, dev_id);
2237 return !ret ? IRQC_IS_NESTED : ret;
2238 }
2239
2240 ret = request_irq(irq, handler, flags, name, dev_id);
2241 return !ret ? IRQC_IS_HARDIRQ : ret;
2242}
2243EXPORT_SYMBOL_GPL(request_any_context_irq);
2244
2245/**
2246 * request_nmi - allocate an interrupt line for NMI delivery
2247 * @irq: Interrupt line to allocate
2248 * @handler: Function to be called when the IRQ occurs.
2249 * Threaded handler for threaded interrupts.
2250 * @irqflags: Interrupt type flags
2251 * @name: An ascii name for the claiming device
2252 * @dev_id: A cookie passed back to the handler function
2253 *
2254 * This call allocates interrupt resources and enables the
2255 * interrupt line and IRQ handling. It sets up the IRQ line
2256 * to be handled as an NMI.
2257 *
2258 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2259 * cannot be threaded.
2260 *
2261 * Interrupt lines requested for NMI delivering must produce per cpu
2262 * interrupts and have auto enabling setting disabled.
2263 *
2264 * Dev_id must be globally unique. Normally the address of the
2265 * device data structure is used as the cookie. Since the handler
2266 * receives this value it makes sense to use it.
2267 *
2268 * If the interrupt line cannot be used to deliver NMIs, function
2269 * will fail and return a negative value.
2270 */
2271int request_nmi(unsigned int irq, irq_handler_t handler,
2272 unsigned long irqflags, const char *name, void *dev_id)
2273{
2274 struct irqaction *action;
2275 struct irq_desc *desc;
2276 unsigned long flags;
2277 int retval;
2278
2279 if (irq == IRQ_NOTCONNECTED)
2280 return -ENOTCONN;
2281
2282 /* NMI cannot be shared, used for Polling */
2283 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2284 return -EINVAL;
2285
2286 if (!(irqflags & IRQF_PERCPU))
2287 return -EINVAL;
2288
2289 if (!handler)
2290 return -EINVAL;
2291
2292 desc = irq_to_desc(irq);
2293
2294 if (!desc || (irq_settings_can_autoenable(desc) &&
2295 !(irqflags & IRQF_NO_AUTOEN)) ||
2296 !irq_settings_can_request(desc) ||
2297 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2298 !irq_supports_nmi(desc))
2299 return -EINVAL;
2300
2301 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2302 if (!action)
2303 return -ENOMEM;
2304
2305 action->handler = handler;
2306 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2307 action->name = name;
2308 action->dev_id = dev_id;
2309
2310 retval = irq_chip_pm_get(&desc->irq_data);
2311 if (retval < 0)
2312 goto err_out;
2313
2314 retval = __setup_irq(irq, desc, action);
2315 if (retval)
2316 goto err_irq_setup;
2317
2318 raw_spin_lock_irqsave(&desc->lock, flags);
2319
2320 /* Setup NMI state */
2321 desc->istate |= IRQS_NMI;
2322 retval = irq_nmi_setup(desc);
2323 if (retval) {
2324 __cleanup_nmi(irq, desc);
2325 raw_spin_unlock_irqrestore(&desc->lock, flags);
2326 return -EINVAL;
2327 }
2328
2329 raw_spin_unlock_irqrestore(&desc->lock, flags);
2330
2331 return 0;
2332
2333err_irq_setup:
2334 irq_chip_pm_put(&desc->irq_data);
2335err_out:
2336 kfree(action);
2337
2338 return retval;
2339}
2340
2341void enable_percpu_irq(unsigned int irq, unsigned int type)
2342{
2343 unsigned int cpu = smp_processor_id();
2344 unsigned long flags;
2345 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2346
2347 if (!desc)
2348 return;
2349
2350 /*
2351 * If the trigger type is not specified by the caller, then
2352 * use the default for this interrupt.
2353 */
2354 type &= IRQ_TYPE_SENSE_MASK;
2355 if (type == IRQ_TYPE_NONE)
2356 type = irqd_get_trigger_type(&desc->irq_data);
2357
2358 if (type != IRQ_TYPE_NONE) {
2359 int ret;
2360
2361 ret = __irq_set_trigger(desc, type);
2362
2363 if (ret) {
2364 WARN(1, "failed to set type for IRQ%d\n", irq);
2365 goto out;
2366 }
2367 }
2368
2369 irq_percpu_enable(desc, cpu);
2370out:
2371 irq_put_desc_unlock(desc, flags);
2372}
2373EXPORT_SYMBOL_GPL(enable_percpu_irq);
2374
2375void enable_percpu_nmi(unsigned int irq, unsigned int type)
2376{
2377 enable_percpu_irq(irq, type);
2378}
2379
2380/**
2381 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2382 * @irq: Linux irq number to check for
2383 *
2384 * Must be called from a non migratable context. Returns the enable
2385 * state of a per cpu interrupt on the current cpu.
2386 */
2387bool irq_percpu_is_enabled(unsigned int irq)
2388{
2389 unsigned int cpu = smp_processor_id();
2390 struct irq_desc *desc;
2391 unsigned long flags;
2392 bool is_enabled;
2393
2394 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2395 if (!desc)
2396 return false;
2397
2398 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2399 irq_put_desc_unlock(desc, flags);
2400
2401 return is_enabled;
2402}
2403EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2404
2405void disable_percpu_irq(unsigned int irq)
2406{
2407 unsigned int cpu = smp_processor_id();
2408 unsigned long flags;
2409 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2410
2411 if (!desc)
2412 return;
2413
2414 irq_percpu_disable(desc, cpu);
2415 irq_put_desc_unlock(desc, flags);
2416}
2417EXPORT_SYMBOL_GPL(disable_percpu_irq);
2418
2419void disable_percpu_nmi(unsigned int irq)
2420{
2421 disable_percpu_irq(irq);
2422}
2423
2424/*
2425 * Internal function to unregister a percpu irqaction.
2426 */
2427static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2428{
2429 struct irq_desc *desc = irq_to_desc(irq);
2430 struct irqaction *action;
2431 unsigned long flags;
2432
2433 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2434
2435 if (!desc)
2436 return NULL;
2437
2438 raw_spin_lock_irqsave(&desc->lock, flags);
2439
2440 action = desc->action;
2441 if (!action || action->percpu_dev_id != dev_id) {
2442 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2443 goto bad;
2444 }
2445
2446 if (!cpumask_empty(desc->percpu_enabled)) {
2447 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2448 irq, cpumask_first(desc->percpu_enabled));
2449 goto bad;
2450 }
2451
2452 /* Found it - now remove it from the list of entries: */
2453 desc->action = NULL;
2454
2455 desc->istate &= ~IRQS_NMI;
2456
2457 raw_spin_unlock_irqrestore(&desc->lock, flags);
2458
2459 unregister_handler_proc(irq, action);
2460
2461 irq_chip_pm_put(&desc->irq_data);
2462 module_put(desc->owner);
2463 return action;
2464
2465bad:
2466 raw_spin_unlock_irqrestore(&desc->lock, flags);
2467 return NULL;
2468}
2469
2470/**
2471 * remove_percpu_irq - free a per-cpu interrupt
2472 * @irq: Interrupt line to free
2473 * @act: irqaction for the interrupt
2474 *
2475 * Used to remove interrupts statically setup by the early boot process.
2476 */
2477void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2478{
2479 struct irq_desc *desc = irq_to_desc(irq);
2480
2481 if (desc && irq_settings_is_per_cpu_devid(desc))
2482 __free_percpu_irq(irq, act->percpu_dev_id);
2483}
2484
2485/**
2486 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2487 * @irq: Interrupt line to free
2488 * @dev_id: Device identity to free
2489 *
2490 * Remove a percpu interrupt handler. The handler is removed, but
2491 * the interrupt line is not disabled. This must be done on each
2492 * CPU before calling this function. The function does not return
2493 * until any executing interrupts for this IRQ have completed.
2494 *
2495 * This function must not be called from interrupt context.
2496 */
2497void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2498{
2499 struct irq_desc *desc = irq_to_desc(irq);
2500
2501 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2502 return;
2503
2504 chip_bus_lock(desc);
2505 kfree(__free_percpu_irq(irq, dev_id));
2506 chip_bus_sync_unlock(desc);
2507}
2508EXPORT_SYMBOL_GPL(free_percpu_irq);
2509
2510void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2511{
2512 struct irq_desc *desc = irq_to_desc(irq);
2513
2514 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2515 return;
2516
2517 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2518 return;
2519
2520 kfree(__free_percpu_irq(irq, dev_id));
2521}
2522
2523/**
2524 * setup_percpu_irq - setup a per-cpu interrupt
2525 * @irq: Interrupt line to setup
2526 * @act: irqaction for the interrupt
2527 *
2528 * Used to statically setup per-cpu interrupts in the early boot process.
2529 */
2530int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2531{
2532 struct irq_desc *desc = irq_to_desc(irq);
2533 int retval;
2534
2535 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2536 return -EINVAL;
2537
2538 retval = irq_chip_pm_get(&desc->irq_data);
2539 if (retval < 0)
2540 return retval;
2541
2542 retval = __setup_irq(irq, desc, act);
2543
2544 if (retval)
2545 irq_chip_pm_put(&desc->irq_data);
2546
2547 return retval;
2548}
2549
2550/**
2551 * __request_percpu_irq - allocate a percpu interrupt line
2552 * @irq: Interrupt line to allocate
2553 * @handler: Function to be called when the IRQ occurs.
2554 * @flags: Interrupt type flags (IRQF_TIMER only)
2555 * @devname: An ascii name for the claiming device
2556 * @dev_id: A percpu cookie passed back to the handler function
2557 *
2558 * This call allocates interrupt resources and enables the
2559 * interrupt on the local CPU. If the interrupt is supposed to be
2560 * enabled on other CPUs, it has to be done on each CPU using
2561 * enable_percpu_irq().
2562 *
2563 * Dev_id must be globally unique. It is a per-cpu variable, and
2564 * the handler gets called with the interrupted CPU's instance of
2565 * that variable.
2566 */
2567int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2568 unsigned long flags, const char *devname,
2569 void __percpu *dev_id)
2570{
2571 struct irqaction *action;
2572 struct irq_desc *desc;
2573 int retval;
2574
2575 if (!dev_id)
2576 return -EINVAL;
2577
2578 desc = irq_to_desc(irq);
2579 if (!desc || !irq_settings_can_request(desc) ||
2580 !irq_settings_is_per_cpu_devid(desc))
2581 return -EINVAL;
2582
2583 if (flags && flags != IRQF_TIMER)
2584 return -EINVAL;
2585
2586 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2587 if (!action)
2588 return -ENOMEM;
2589
2590 action->handler = handler;
2591 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2592 action->name = devname;
2593 action->percpu_dev_id = dev_id;
2594
2595 retval = irq_chip_pm_get(&desc->irq_data);
2596 if (retval < 0) {
2597 kfree(action);
2598 return retval;
2599 }
2600
2601 retval = __setup_irq(irq, desc, action);
2602
2603 if (retval) {
2604 irq_chip_pm_put(&desc->irq_data);
2605 kfree(action);
2606 }
2607
2608 return retval;
2609}
2610EXPORT_SYMBOL_GPL(__request_percpu_irq);
2611
2612/**
2613 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2614 * @irq: Interrupt line to allocate
2615 * @handler: Function to be called when the IRQ occurs.
2616 * @name: An ascii name for the claiming device
2617 * @dev_id: A percpu cookie passed back to the handler function
2618 *
2619 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2620 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2621 * being enabled on the same CPU by using enable_percpu_nmi().
2622 *
2623 * Dev_id must be globally unique. It is a per-cpu variable, and
2624 * the handler gets called with the interrupted CPU's instance of
2625 * that variable.
2626 *
2627 * Interrupt lines requested for NMI delivering should have auto enabling
2628 * setting disabled.
2629 *
2630 * If the interrupt line cannot be used to deliver NMIs, function
2631 * will fail returning a negative value.
2632 */
2633int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2634 const char *name, void __percpu *dev_id)
2635{
2636 struct irqaction *action;
2637 struct irq_desc *desc;
2638 unsigned long flags;
2639 int retval;
2640
2641 if (!handler)
2642 return -EINVAL;
2643
2644 desc = irq_to_desc(irq);
2645
2646 if (!desc || !irq_settings_can_request(desc) ||
2647 !irq_settings_is_per_cpu_devid(desc) ||
2648 irq_settings_can_autoenable(desc) ||
2649 !irq_supports_nmi(desc))
2650 return -EINVAL;
2651
2652 /* The line cannot already be NMI */
2653 if (desc->istate & IRQS_NMI)
2654 return -EINVAL;
2655
2656 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2657 if (!action)
2658 return -ENOMEM;
2659
2660 action->handler = handler;
2661 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2662 | IRQF_NOBALANCING;
2663 action->name = name;
2664 action->percpu_dev_id = dev_id;
2665
2666 retval = irq_chip_pm_get(&desc->irq_data);
2667 if (retval < 0)
2668 goto err_out;
2669
2670 retval = __setup_irq(irq, desc, action);
2671 if (retval)
2672 goto err_irq_setup;
2673
2674 raw_spin_lock_irqsave(&desc->lock, flags);
2675 desc->istate |= IRQS_NMI;
2676 raw_spin_unlock_irqrestore(&desc->lock, flags);
2677
2678 return 0;
2679
2680err_irq_setup:
2681 irq_chip_pm_put(&desc->irq_data);
2682err_out:
2683 kfree(action);
2684
2685 return retval;
2686}
2687
2688/**
2689 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2690 * @irq: Interrupt line to prepare for NMI delivery
2691 *
2692 * This call prepares an interrupt line to deliver NMI on the current CPU,
2693 * before that interrupt line gets enabled with enable_percpu_nmi().
2694 *
2695 * As a CPU local operation, this should be called from non-preemptible
2696 * context.
2697 *
2698 * If the interrupt line cannot be used to deliver NMIs, function
2699 * will fail returning a negative value.
2700 */
2701int prepare_percpu_nmi(unsigned int irq)
2702{
2703 unsigned long flags;
2704 struct irq_desc *desc;
2705 int ret = 0;
2706
2707 WARN_ON(preemptible());
2708
2709 desc = irq_get_desc_lock(irq, &flags,
2710 IRQ_GET_DESC_CHECK_PERCPU);
2711 if (!desc)
2712 return -EINVAL;
2713
2714 if (WARN(!(desc->istate & IRQS_NMI),
2715 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2716 irq)) {
2717 ret = -EINVAL;
2718 goto out;
2719 }
2720
2721 ret = irq_nmi_setup(desc);
2722 if (ret) {
2723 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2724 goto out;
2725 }
2726
2727out:
2728 irq_put_desc_unlock(desc, flags);
2729 return ret;
2730}
2731
2732/**
2733 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2734 * @irq: Interrupt line from which CPU local NMI configuration should be
2735 * removed
2736 *
2737 * This call undoes the setup done by prepare_percpu_nmi().
2738 *
2739 * IRQ line should not be enabled for the current CPU.
2740 *
2741 * As a CPU local operation, this should be called from non-preemptible
2742 * context.
2743 */
2744void teardown_percpu_nmi(unsigned int irq)
2745{
2746 unsigned long flags;
2747 struct irq_desc *desc;
2748
2749 WARN_ON(preemptible());
2750
2751 desc = irq_get_desc_lock(irq, &flags,
2752 IRQ_GET_DESC_CHECK_PERCPU);
2753 if (!desc)
2754 return;
2755
2756 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2757 goto out;
2758
2759 irq_nmi_teardown(desc);
2760out:
2761 irq_put_desc_unlock(desc, flags);
2762}
2763
2764int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2765 bool *state)
2766{
2767 struct irq_chip *chip;
2768 int err = -EINVAL;
2769
2770 do {
2771 chip = irq_data_get_irq_chip(data);
2772 if (WARN_ON_ONCE(!chip))
2773 return -ENODEV;
2774 if (chip->irq_get_irqchip_state)
2775 break;
2776#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2777 data = data->parent_data;
2778#else
2779 data = NULL;
2780#endif
2781 } while (data);
2782
2783 if (data)
2784 err = chip->irq_get_irqchip_state(data, which, state);
2785 return err;
2786}
2787
2788/**
2789 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2790 * @irq: Interrupt line that is forwarded to a VM
2791 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2792 * @state: a pointer to a boolean where the state is to be stored
2793 *
2794 * This call snapshots the internal irqchip state of an
2795 * interrupt, returning into @state the bit corresponding to
2796 * stage @which
2797 *
2798 * This function should be called with preemption disabled if the
2799 * interrupt controller has per-cpu registers.
2800 */
2801int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2802 bool *state)
2803{
2804 struct irq_desc *desc;
2805 struct irq_data *data;
2806 unsigned long flags;
2807 int err = -EINVAL;
2808
2809 desc = irq_get_desc_buslock(irq, &flags, 0);
2810 if (!desc)
2811 return err;
2812
2813 data = irq_desc_get_irq_data(desc);
2814
2815 err = __irq_get_irqchip_state(data, which, state);
2816
2817 irq_put_desc_busunlock(desc, flags);
2818 return err;
2819}
2820EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2821
2822/**
2823 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2824 * @irq: Interrupt line that is forwarded to a VM
2825 * @which: State to be restored (one of IRQCHIP_STATE_*)
2826 * @val: Value corresponding to @which
2827 *
2828 * This call sets the internal irqchip state of an interrupt,
2829 * depending on the value of @which.
2830 *
2831 * This function should be called with preemption disabled if the
2832 * interrupt controller has per-cpu registers.
2833 */
2834int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2835 bool val)
2836{
2837 struct irq_desc *desc;
2838 struct irq_data *data;
2839 struct irq_chip *chip;
2840 unsigned long flags;
2841 int err = -EINVAL;
2842
2843 desc = irq_get_desc_buslock(irq, &flags, 0);
2844 if (!desc)
2845 return err;
2846
2847 data = irq_desc_get_irq_data(desc);
2848
2849 do {
2850 chip = irq_data_get_irq_chip(data);
2851 if (WARN_ON_ONCE(!chip)) {
2852 err = -ENODEV;
2853 goto out_unlock;
2854 }
2855 if (chip->irq_set_irqchip_state)
2856 break;
2857#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2858 data = data->parent_data;
2859#else
2860 data = NULL;
2861#endif
2862 } while (data);
2863
2864 if (data)
2865 err = chip->irq_set_irqchip_state(data, which, val);
2866
2867out_unlock:
2868 irq_put_desc_busunlock(desc, flags);
2869 return err;
2870}
2871EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2872
2873/**
2874 * irq_has_action - Check whether an interrupt is requested
2875 * @irq: The linux irq number
2876 *
2877 * Returns: A snapshot of the current state
2878 */
2879bool irq_has_action(unsigned int irq)
2880{
2881 bool res;
2882
2883 rcu_read_lock();
2884 res = irq_desc_has_action(irq_to_desc(irq));
2885 rcu_read_unlock();
2886 return res;
2887}
2888EXPORT_SYMBOL_GPL(irq_has_action);
2889
2890/**
2891 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2892 * @irq: The linux irq number
2893 * @bitmask: The bitmask to evaluate
2894 *
2895 * Returns: True if one of the bits in @bitmask is set
2896 */
2897bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2898{
2899 struct irq_desc *desc;
2900 bool res = false;
2901
2902 rcu_read_lock();
2903 desc = irq_to_desc(irq);
2904 if (desc)
2905 res = !!(desc->status_use_accessors & bitmask);
2906 rcu_read_unlock();
2907 return res;
2908}
2909EXPORT_SYMBOL_GPL(irq_check_status_bit);