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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
29
30static int __init setup_forced_irqthreads(char *arg)
31{
32 static_branch_enable(&force_irqthreads_key);
33 return 0;
34}
35early_param("threadirqs", setup_forced_irqthreads);
36#endif
37
38static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
39{
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
41 bool inprogress;
42
43 do {
44 unsigned long flags;
45
46 /*
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
49 */
50 while (irqd_irq_inprogress(&desc->irq_data))
51 cpu_relax();
52
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
56
57 /*
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
61 */
62 if (!inprogress && sync_chip) {
63 /*
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
66 */
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
68 &inprogress);
69 }
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
71
72 /* Oops, that failed? */
73 } while (inprogress);
74}
75
76/**
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
79 *
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
84 * into account.
85 *
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
88 *
89 * Returns: false if a threaded handler is active.
90 *
91 * This function may be called - with care - from IRQ context.
92 *
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
96 * is the current CPU.
97 */
98bool synchronize_hardirq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
105 }
106
107 return true;
108}
109EXPORT_SYMBOL(synchronize_hardirq);
110
111static void __synchronize_irq(struct irq_desc *desc)
112{
113 __synchronize_hardirq(desc, true);
114 /*
115 * We made sure that no hardirq handler is running. Now verify that no
116 * threaded handlers are active.
117 */
118 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
119}
120
121/**
122 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
123 * @irq: interrupt number to wait for
124 *
125 * This function waits for any pending IRQ handlers for this interrupt
126 * to complete before returning. If you use this function while
127 * holding a resource the IRQ handler may need you will deadlock.
128 *
129 * Can only be called from preemptible code as it might sleep when
130 * an interrupt thread is associated to @irq.
131 *
132 * It optionally makes sure (when the irq chip supports that method)
133 * that the interrupt is not pending in any CPU and waiting for
134 * service.
135 */
136void synchronize_irq(unsigned int irq)
137{
138 struct irq_desc *desc = irq_to_desc(irq);
139
140 if (desc)
141 __synchronize_irq(desc);
142}
143EXPORT_SYMBOL(synchronize_irq);
144
145#ifdef CONFIG_SMP
146cpumask_var_t irq_default_affinity;
147
148static bool __irq_can_set_affinity(struct irq_desc *desc)
149{
150 if (!desc || !irqd_can_balance(&desc->irq_data) ||
151 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
152 return false;
153 return true;
154}
155
156/**
157 * irq_can_set_affinity - Check if the affinity of a given irq can be set
158 * @irq: Interrupt to check
159 *
160 */
161int irq_can_set_affinity(unsigned int irq)
162{
163 return __irq_can_set_affinity(irq_to_desc(irq));
164}
165
166/**
167 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
168 * @irq: Interrupt to check
169 *
170 * Like irq_can_set_affinity() above, but additionally checks for the
171 * AFFINITY_MANAGED flag.
172 */
173bool irq_can_set_affinity_usr(unsigned int irq)
174{
175 struct irq_desc *desc = irq_to_desc(irq);
176
177 return __irq_can_set_affinity(desc) &&
178 !irqd_affinity_is_managed(&desc->irq_data);
179}
180
181/**
182 * irq_set_thread_affinity - Notify irq threads to adjust affinity
183 * @desc: irq descriptor which has affinity changed
184 *
185 * We just set IRQTF_AFFINITY and delegate the affinity setting
186 * to the interrupt thread itself. We can not call
187 * set_cpus_allowed_ptr() here as we hold desc->lock and this
188 * code can be called from hard interrupt context.
189 */
190void irq_set_thread_affinity(struct irq_desc *desc)
191{
192 struct irqaction *action;
193
194 for_each_action_of_desc(desc, action) {
195 if (action->thread) {
196 set_bit(IRQTF_AFFINITY, &action->thread_flags);
197 wake_up_process(action->thread);
198 }
199 if (action->secondary && action->secondary->thread) {
200 set_bit(IRQTF_AFFINITY, &action->secondary->thread_flags);
201 wake_up_process(action->secondary->thread);
202 }
203 }
204}
205
206#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
207static void irq_validate_effective_affinity(struct irq_data *data)
208{
209 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
210 struct irq_chip *chip = irq_data_get_irq_chip(data);
211
212 if (!cpumask_empty(m))
213 return;
214 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
215 chip->name, data->irq);
216}
217#else
218static inline void irq_validate_effective_affinity(struct irq_data *data) { }
219#endif
220
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 const struct cpumask *prog_mask;
227 int ret;
228
229 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
230 static struct cpumask tmp_mask;
231
232 if (!chip || !chip->irq_set_affinity)
233 return -EINVAL;
234
235 raw_spin_lock(&tmp_mask_lock);
236 /*
237 * If this is a managed interrupt and housekeeping is enabled on
238 * it check whether the requested affinity mask intersects with
239 * a housekeeping CPU. If so, then remove the isolated CPUs from
240 * the mask and just keep the housekeeping CPU(s). This prevents
241 * the affinity setter from routing the interrupt to an isolated
242 * CPU to avoid that I/O submitted from a housekeeping CPU causes
243 * interrupts on an isolated one.
244 *
245 * If the masks do not intersect or include online CPU(s) then
246 * keep the requested mask. The isolated target CPUs are only
247 * receiving interrupts when the I/O operation was submitted
248 * directly from them.
249 *
250 * If all housekeeping CPUs in the affinity mask are offline, the
251 * interrupt will be migrated by the CPU hotplug code once a
252 * housekeeping CPU which belongs to the affinity mask comes
253 * online.
254 */
255 if (irqd_affinity_is_managed(data) &&
256 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
257 const struct cpumask *hk_mask;
258
259 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
260
261 cpumask_and(&tmp_mask, mask, hk_mask);
262 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
263 prog_mask = mask;
264 else
265 prog_mask = &tmp_mask;
266 } else {
267 prog_mask = mask;
268 }
269
270 /*
271 * Make sure we only provide online CPUs to the irqchip,
272 * unless we are being asked to force the affinity (in which
273 * case we do as we are told).
274 */
275 cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
276 if (!force && !cpumask_empty(&tmp_mask))
277 ret = chip->irq_set_affinity(data, &tmp_mask, force);
278 else if (force)
279 ret = chip->irq_set_affinity(data, mask, force);
280 else
281 ret = -EINVAL;
282
283 raw_spin_unlock(&tmp_mask_lock);
284
285 switch (ret) {
286 case IRQ_SET_MASK_OK:
287 case IRQ_SET_MASK_OK_DONE:
288 cpumask_copy(desc->irq_common_data.affinity, mask);
289 fallthrough;
290 case IRQ_SET_MASK_OK_NOCOPY:
291 irq_validate_effective_affinity(data);
292 irq_set_thread_affinity(desc);
293 ret = 0;
294 }
295
296 return ret;
297}
298
299#ifdef CONFIG_GENERIC_PENDING_IRQ
300static inline int irq_set_affinity_pending(struct irq_data *data,
301 const struct cpumask *dest)
302{
303 struct irq_desc *desc = irq_data_to_desc(data);
304
305 irqd_set_move_pending(data);
306 irq_copy_pending(desc, dest);
307 return 0;
308}
309#else
310static inline int irq_set_affinity_pending(struct irq_data *data,
311 const struct cpumask *dest)
312{
313 return -EBUSY;
314}
315#endif
316
317static int irq_try_set_affinity(struct irq_data *data,
318 const struct cpumask *dest, bool force)
319{
320 int ret = irq_do_set_affinity(data, dest, force);
321
322 /*
323 * In case that the underlying vector management is busy and the
324 * architecture supports the generic pending mechanism then utilize
325 * this to avoid returning an error to user space.
326 */
327 if (ret == -EBUSY && !force)
328 ret = irq_set_affinity_pending(data, dest);
329 return ret;
330}
331
332static bool irq_set_affinity_deactivated(struct irq_data *data,
333 const struct cpumask *mask)
334{
335 struct irq_desc *desc = irq_data_to_desc(data);
336
337 /*
338 * Handle irq chips which can handle affinity only in activated
339 * state correctly
340 *
341 * If the interrupt is not yet activated, just store the affinity
342 * mask and do not call the chip driver at all. On activation the
343 * driver has to make sure anyway that the interrupt is in a
344 * usable state so startup works.
345 */
346 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
347 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
348 return false;
349
350 cpumask_copy(desc->irq_common_data.affinity, mask);
351 irq_data_update_effective_affinity(data, mask);
352 irqd_set(data, IRQD_AFFINITY_SET);
353 return true;
354}
355
356int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
357 bool force)
358{
359 struct irq_chip *chip = irq_data_get_irq_chip(data);
360 struct irq_desc *desc = irq_data_to_desc(data);
361 int ret = 0;
362
363 if (!chip || !chip->irq_set_affinity)
364 return -EINVAL;
365
366 if (irq_set_affinity_deactivated(data, mask))
367 return 0;
368
369 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
370 ret = irq_try_set_affinity(data, mask, force);
371 } else {
372 irqd_set_move_pending(data);
373 irq_copy_pending(desc, mask);
374 }
375
376 if (desc->affinity_notify) {
377 kref_get(&desc->affinity_notify->kref);
378 if (!schedule_work(&desc->affinity_notify->work)) {
379 /* Work was already scheduled, drop our extra ref */
380 kref_put(&desc->affinity_notify->kref,
381 desc->affinity_notify->release);
382 }
383 }
384 irqd_set(data, IRQD_AFFINITY_SET);
385
386 return ret;
387}
388
389/**
390 * irq_update_affinity_desc - Update affinity management for an interrupt
391 * @irq: The interrupt number to update
392 * @affinity: Pointer to the affinity descriptor
393 *
394 * This interface can be used to configure the affinity management of
395 * interrupts which have been allocated already.
396 *
397 * There are certain limitations on when it may be used - attempts to use it
398 * for when the kernel is configured for generic IRQ reservation mode (in
399 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
400 * managed/non-managed interrupt accounting. In addition, attempts to use it on
401 * an interrupt which is already started or which has already been configured
402 * as managed will also fail, as these mean invalid init state or double init.
403 */
404int irq_update_affinity_desc(unsigned int irq,
405 struct irq_affinity_desc *affinity)
406{
407 struct irq_desc *desc;
408 unsigned long flags;
409 bool activated;
410 int ret = 0;
411
412 /*
413 * Supporting this with the reservation scheme used by x86 needs
414 * some more thought. Fail it for now.
415 */
416 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
417 return -EOPNOTSUPP;
418
419 desc = irq_get_desc_buslock(irq, &flags, 0);
420 if (!desc)
421 return -EINVAL;
422
423 /* Requires the interrupt to be shut down */
424 if (irqd_is_started(&desc->irq_data)) {
425 ret = -EBUSY;
426 goto out_unlock;
427 }
428
429 /* Interrupts which are already managed cannot be modified */
430 if (irqd_affinity_is_managed(&desc->irq_data)) {
431 ret = -EBUSY;
432 goto out_unlock;
433 }
434
435 /*
436 * Deactivate the interrupt. That's required to undo
437 * anything an earlier activation has established.
438 */
439 activated = irqd_is_activated(&desc->irq_data);
440 if (activated)
441 irq_domain_deactivate_irq(&desc->irq_data);
442
443 if (affinity->is_managed) {
444 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
445 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
446 }
447
448 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
449
450 /* Restore the activation state */
451 if (activated)
452 irq_domain_activate_irq(&desc->irq_data, false);
453
454out_unlock:
455 irq_put_desc_busunlock(desc, flags);
456 return ret;
457}
458
459static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
460 bool force)
461{
462 struct irq_desc *desc = irq_to_desc(irq);
463 unsigned long flags;
464 int ret;
465
466 if (!desc)
467 return -EINVAL;
468
469 raw_spin_lock_irqsave(&desc->lock, flags);
470 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
471 raw_spin_unlock_irqrestore(&desc->lock, flags);
472 return ret;
473}
474
475/**
476 * irq_set_affinity - Set the irq affinity of a given irq
477 * @irq: Interrupt to set affinity
478 * @cpumask: cpumask
479 *
480 * Fails if cpumask does not contain an online CPU
481 */
482int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
483{
484 return __irq_set_affinity(irq, cpumask, false);
485}
486EXPORT_SYMBOL_GPL(irq_set_affinity);
487
488/**
489 * irq_force_affinity - Force the irq affinity of a given irq
490 * @irq: Interrupt to set affinity
491 * @cpumask: cpumask
492 *
493 * Same as irq_set_affinity, but without checking the mask against
494 * online cpus.
495 *
496 * Solely for low level cpu hotplug code, where we need to make per
497 * cpu interrupts affine before the cpu becomes online.
498 */
499int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
500{
501 return __irq_set_affinity(irq, cpumask, true);
502}
503EXPORT_SYMBOL_GPL(irq_force_affinity);
504
505int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
506 bool setaffinity)
507{
508 unsigned long flags;
509 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
510
511 if (!desc)
512 return -EINVAL;
513 desc->affinity_hint = m;
514 irq_put_desc_unlock(desc, flags);
515 if (m && setaffinity)
516 __irq_set_affinity(irq, m, false);
517 return 0;
518}
519EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
520
521static void irq_affinity_notify(struct work_struct *work)
522{
523 struct irq_affinity_notify *notify =
524 container_of(work, struct irq_affinity_notify, work);
525 struct irq_desc *desc = irq_to_desc(notify->irq);
526 cpumask_var_t cpumask;
527 unsigned long flags;
528
529 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
530 goto out;
531
532 raw_spin_lock_irqsave(&desc->lock, flags);
533 if (irq_move_pending(&desc->irq_data))
534 irq_get_pending(cpumask, desc);
535 else
536 cpumask_copy(cpumask, desc->irq_common_data.affinity);
537 raw_spin_unlock_irqrestore(&desc->lock, flags);
538
539 notify->notify(notify, cpumask);
540
541 free_cpumask_var(cpumask);
542out:
543 kref_put(¬ify->kref, notify->release);
544}
545
546/**
547 * irq_set_affinity_notifier - control notification of IRQ affinity changes
548 * @irq: Interrupt for which to enable/disable notification
549 * @notify: Context for notification, or %NULL to disable
550 * notification. Function pointers must be initialised;
551 * the other fields will be initialised by this function.
552 *
553 * Must be called in process context. Notification may only be enabled
554 * after the IRQ is allocated and must be disabled before the IRQ is
555 * freed using free_irq().
556 */
557int
558irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
559{
560 struct irq_desc *desc = irq_to_desc(irq);
561 struct irq_affinity_notify *old_notify;
562 unsigned long flags;
563
564 /* The release function is promised process context */
565 might_sleep();
566
567 if (!desc || desc->istate & IRQS_NMI)
568 return -EINVAL;
569
570 /* Complete initialisation of *notify */
571 if (notify) {
572 notify->irq = irq;
573 kref_init(¬ify->kref);
574 INIT_WORK(¬ify->work, irq_affinity_notify);
575 }
576
577 raw_spin_lock_irqsave(&desc->lock, flags);
578 old_notify = desc->affinity_notify;
579 desc->affinity_notify = notify;
580 raw_spin_unlock_irqrestore(&desc->lock, flags);
581
582 if (old_notify) {
583 if (cancel_work_sync(&old_notify->work)) {
584 /* Pending work had a ref, put that one too */
585 kref_put(&old_notify->kref, old_notify->release);
586 }
587 kref_put(&old_notify->kref, old_notify->release);
588 }
589
590 return 0;
591}
592EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
593
594#ifndef CONFIG_AUTO_IRQ_AFFINITY
595/*
596 * Generic version of the affinity autoselector.
597 */
598int irq_setup_affinity(struct irq_desc *desc)
599{
600 struct cpumask *set = irq_default_affinity;
601 int ret, node = irq_desc_get_node(desc);
602 static DEFINE_RAW_SPINLOCK(mask_lock);
603 static struct cpumask mask;
604
605 /* Excludes PER_CPU and NO_BALANCE interrupts */
606 if (!__irq_can_set_affinity(desc))
607 return 0;
608
609 raw_spin_lock(&mask_lock);
610 /*
611 * Preserve the managed affinity setting and a userspace affinity
612 * setup, but make sure that one of the targets is online.
613 */
614 if (irqd_affinity_is_managed(&desc->irq_data) ||
615 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
616 if (cpumask_intersects(desc->irq_common_data.affinity,
617 cpu_online_mask))
618 set = desc->irq_common_data.affinity;
619 else
620 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
621 }
622
623 cpumask_and(&mask, cpu_online_mask, set);
624 if (cpumask_empty(&mask))
625 cpumask_copy(&mask, cpu_online_mask);
626
627 if (node != NUMA_NO_NODE) {
628 const struct cpumask *nodemask = cpumask_of_node(node);
629
630 /* make sure at least one of the cpus in nodemask is online */
631 if (cpumask_intersects(&mask, nodemask))
632 cpumask_and(&mask, &mask, nodemask);
633 }
634 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
635 raw_spin_unlock(&mask_lock);
636 return ret;
637}
638#else
639/* Wrapper for ALPHA specific affinity selector magic */
640int irq_setup_affinity(struct irq_desc *desc)
641{
642 return irq_select_affinity(irq_desc_get_irq(desc));
643}
644#endif /* CONFIG_AUTO_IRQ_AFFINITY */
645#endif /* CONFIG_SMP */
646
647
648/**
649 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
650 * @irq: interrupt number to set affinity
651 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
652 * specific data for percpu_devid interrupts
653 *
654 * This function uses the vCPU specific data to set the vCPU
655 * affinity for an irq. The vCPU specific data is passed from
656 * outside, such as KVM. One example code path is as below:
657 * KVM -> IOMMU -> irq_set_vcpu_affinity().
658 */
659int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
660{
661 unsigned long flags;
662 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
663 struct irq_data *data;
664 struct irq_chip *chip;
665 int ret = -ENOSYS;
666
667 if (!desc)
668 return -EINVAL;
669
670 data = irq_desc_get_irq_data(desc);
671 do {
672 chip = irq_data_get_irq_chip(data);
673 if (chip && chip->irq_set_vcpu_affinity)
674 break;
675#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
676 data = data->parent_data;
677#else
678 data = NULL;
679#endif
680 } while (data);
681
682 if (data)
683 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
684 irq_put_desc_unlock(desc, flags);
685
686 return ret;
687}
688EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
689
690void __disable_irq(struct irq_desc *desc)
691{
692 if (!desc->depth++)
693 irq_disable(desc);
694}
695
696static int __disable_irq_nosync(unsigned int irq)
697{
698 unsigned long flags;
699 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
700
701 if (!desc)
702 return -EINVAL;
703 __disable_irq(desc);
704 irq_put_desc_busunlock(desc, flags);
705 return 0;
706}
707
708/**
709 * disable_irq_nosync - disable an irq without waiting
710 * @irq: Interrupt to disable
711 *
712 * Disable the selected interrupt line. Disables and Enables are
713 * nested.
714 * Unlike disable_irq(), this function does not ensure existing
715 * instances of the IRQ handler have completed before returning.
716 *
717 * This function may be called from IRQ context.
718 */
719void disable_irq_nosync(unsigned int irq)
720{
721 __disable_irq_nosync(irq);
722}
723EXPORT_SYMBOL(disable_irq_nosync);
724
725/**
726 * disable_irq - disable an irq and wait for completion
727 * @irq: Interrupt to disable
728 *
729 * Disable the selected interrupt line. Enables and Disables are
730 * nested.
731 * This function waits for any pending IRQ handlers for this interrupt
732 * to complete before returning. If you use this function while
733 * holding a resource the IRQ handler may need you will deadlock.
734 *
735 * Can only be called from preemptible code as it might sleep when
736 * an interrupt thread is associated to @irq.
737 *
738 */
739void disable_irq(unsigned int irq)
740{
741 might_sleep();
742 if (!__disable_irq_nosync(irq))
743 synchronize_irq(irq);
744}
745EXPORT_SYMBOL(disable_irq);
746
747/**
748 * disable_hardirq - disables an irq and waits for hardirq completion
749 * @irq: Interrupt to disable
750 *
751 * Disable the selected interrupt line. Enables and Disables are
752 * nested.
753 * This function waits for any pending hard IRQ handlers for this
754 * interrupt to complete before returning. If you use this function while
755 * holding a resource the hard IRQ handler may need you will deadlock.
756 *
757 * When used to optimistically disable an interrupt from atomic context
758 * the return value must be checked.
759 *
760 * Returns: false if a threaded handler is active.
761 *
762 * This function may be called - with care - from IRQ context.
763 */
764bool disable_hardirq(unsigned int irq)
765{
766 if (!__disable_irq_nosync(irq))
767 return synchronize_hardirq(irq);
768
769 return false;
770}
771EXPORT_SYMBOL_GPL(disable_hardirq);
772
773/**
774 * disable_nmi_nosync - disable an nmi without waiting
775 * @irq: Interrupt to disable
776 *
777 * Disable the selected interrupt line. Disables and enables are
778 * nested.
779 * The interrupt to disable must have been requested through request_nmi.
780 * Unlike disable_nmi(), this function does not ensure existing
781 * instances of the IRQ handler have completed before returning.
782 */
783void disable_nmi_nosync(unsigned int irq)
784{
785 disable_irq_nosync(irq);
786}
787
788void __enable_irq(struct irq_desc *desc)
789{
790 switch (desc->depth) {
791 case 0:
792 err_out:
793 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
794 irq_desc_get_irq(desc));
795 break;
796 case 1: {
797 if (desc->istate & IRQS_SUSPENDED)
798 goto err_out;
799 /* Prevent probing on this irq: */
800 irq_settings_set_noprobe(desc);
801 /*
802 * Call irq_startup() not irq_enable() here because the
803 * interrupt might be marked NOAUTOEN. So irq_startup()
804 * needs to be invoked when it gets enabled the first
805 * time. If it was already started up, then irq_startup()
806 * will invoke irq_enable() under the hood.
807 */
808 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
809 break;
810 }
811 default:
812 desc->depth--;
813 }
814}
815
816/**
817 * enable_irq - enable handling of an irq
818 * @irq: Interrupt to enable
819 *
820 * Undoes the effect of one call to disable_irq(). If this
821 * matches the last disable, processing of interrupts on this
822 * IRQ line is re-enabled.
823 *
824 * This function may be called from IRQ context only when
825 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
826 */
827void enable_irq(unsigned int irq)
828{
829 unsigned long flags;
830 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
831
832 if (!desc)
833 return;
834 if (WARN(!desc->irq_data.chip,
835 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
836 goto out;
837
838 __enable_irq(desc);
839out:
840 irq_put_desc_busunlock(desc, flags);
841}
842EXPORT_SYMBOL(enable_irq);
843
844/**
845 * enable_nmi - enable handling of an nmi
846 * @irq: Interrupt to enable
847 *
848 * The interrupt to enable must have been requested through request_nmi.
849 * Undoes the effect of one call to disable_nmi(). If this
850 * matches the last disable, processing of interrupts on this
851 * IRQ line is re-enabled.
852 */
853void enable_nmi(unsigned int irq)
854{
855 enable_irq(irq);
856}
857
858static int set_irq_wake_real(unsigned int irq, unsigned int on)
859{
860 struct irq_desc *desc = irq_to_desc(irq);
861 int ret = -ENXIO;
862
863 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
864 return 0;
865
866 if (desc->irq_data.chip->irq_set_wake)
867 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
868
869 return ret;
870}
871
872/**
873 * irq_set_irq_wake - control irq power management wakeup
874 * @irq: interrupt to control
875 * @on: enable/disable power management wakeup
876 *
877 * Enable/disable power management wakeup mode, which is
878 * disabled by default. Enables and disables must match,
879 * just as they match for non-wakeup mode support.
880 *
881 * Wakeup mode lets this IRQ wake the system from sleep
882 * states like "suspend to RAM".
883 *
884 * Note: irq enable/disable state is completely orthogonal
885 * to the enable/disable state of irq wake. An irq can be
886 * disabled with disable_irq() and still wake the system as
887 * long as the irq has wake enabled. If this does not hold,
888 * then the underlying irq chip and the related driver need
889 * to be investigated.
890 */
891int irq_set_irq_wake(unsigned int irq, unsigned int on)
892{
893 unsigned long flags;
894 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
895 int ret = 0;
896
897 if (!desc)
898 return -EINVAL;
899
900 /* Don't use NMIs as wake up interrupts please */
901 if (desc->istate & IRQS_NMI) {
902 ret = -EINVAL;
903 goto out_unlock;
904 }
905
906 /* wakeup-capable irqs can be shared between drivers that
907 * don't need to have the same sleep mode behaviors.
908 */
909 if (on) {
910 if (desc->wake_depth++ == 0) {
911 ret = set_irq_wake_real(irq, on);
912 if (ret)
913 desc->wake_depth = 0;
914 else
915 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
916 }
917 } else {
918 if (desc->wake_depth == 0) {
919 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
920 } else if (--desc->wake_depth == 0) {
921 ret = set_irq_wake_real(irq, on);
922 if (ret)
923 desc->wake_depth = 1;
924 else
925 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
926 }
927 }
928
929out_unlock:
930 irq_put_desc_busunlock(desc, flags);
931 return ret;
932}
933EXPORT_SYMBOL(irq_set_irq_wake);
934
935/*
936 * Internal function that tells the architecture code whether a
937 * particular irq has been exclusively allocated or is available
938 * for driver use.
939 */
940int can_request_irq(unsigned int irq, unsigned long irqflags)
941{
942 unsigned long flags;
943 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
944 int canrequest = 0;
945
946 if (!desc)
947 return 0;
948
949 if (irq_settings_can_request(desc)) {
950 if (!desc->action ||
951 irqflags & desc->action->flags & IRQF_SHARED)
952 canrequest = 1;
953 }
954 irq_put_desc_unlock(desc, flags);
955 return canrequest;
956}
957
958int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
959{
960 struct irq_chip *chip = desc->irq_data.chip;
961 int ret, unmask = 0;
962
963 if (!chip || !chip->irq_set_type) {
964 /*
965 * IRQF_TRIGGER_* but the PIC does not support multiple
966 * flow-types?
967 */
968 pr_debug("No set_type function for IRQ %d (%s)\n",
969 irq_desc_get_irq(desc),
970 chip ? (chip->name ? : "unknown") : "unknown");
971 return 0;
972 }
973
974 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
975 if (!irqd_irq_masked(&desc->irq_data))
976 mask_irq(desc);
977 if (!irqd_irq_disabled(&desc->irq_data))
978 unmask = 1;
979 }
980
981 /* Mask all flags except trigger mode */
982 flags &= IRQ_TYPE_SENSE_MASK;
983 ret = chip->irq_set_type(&desc->irq_data, flags);
984
985 switch (ret) {
986 case IRQ_SET_MASK_OK:
987 case IRQ_SET_MASK_OK_DONE:
988 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
989 irqd_set(&desc->irq_data, flags);
990 fallthrough;
991
992 case IRQ_SET_MASK_OK_NOCOPY:
993 flags = irqd_get_trigger_type(&desc->irq_data);
994 irq_settings_set_trigger_mask(desc, flags);
995 irqd_clear(&desc->irq_data, IRQD_LEVEL);
996 irq_settings_clr_level(desc);
997 if (flags & IRQ_TYPE_LEVEL_MASK) {
998 irq_settings_set_level(desc);
999 irqd_set(&desc->irq_data, IRQD_LEVEL);
1000 }
1001
1002 ret = 0;
1003 break;
1004 default:
1005 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
1006 flags, irq_desc_get_irq(desc), chip->irq_set_type);
1007 }
1008 if (unmask)
1009 unmask_irq(desc);
1010 return ret;
1011}
1012
1013#ifdef CONFIG_HARDIRQS_SW_RESEND
1014int irq_set_parent(int irq, int parent_irq)
1015{
1016 unsigned long flags;
1017 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1018
1019 if (!desc)
1020 return -EINVAL;
1021
1022 desc->parent_irq = parent_irq;
1023
1024 irq_put_desc_unlock(desc, flags);
1025 return 0;
1026}
1027EXPORT_SYMBOL_GPL(irq_set_parent);
1028#endif
1029
1030/*
1031 * Default primary interrupt handler for threaded interrupts. Is
1032 * assigned as primary handler when request_threaded_irq is called
1033 * with handler == NULL. Useful for oneshot interrupts.
1034 */
1035static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1036{
1037 return IRQ_WAKE_THREAD;
1038}
1039
1040/*
1041 * Primary handler for nested threaded interrupts. Should never be
1042 * called.
1043 */
1044static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1045{
1046 WARN(1, "Primary handler called for nested irq %d\n", irq);
1047 return IRQ_NONE;
1048}
1049
1050static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1051{
1052 WARN(1, "Secondary action handler called for irq %d\n", irq);
1053 return IRQ_NONE;
1054}
1055
1056#ifdef CONFIG_SMP
1057/*
1058 * Check whether we need to change the affinity of the interrupt thread.
1059 */
1060static void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1061{
1062 cpumask_var_t mask;
1063 bool valid = false;
1064
1065 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1066 return;
1067
1068 __set_current_state(TASK_RUNNING);
1069
1070 /*
1071 * In case we are out of memory we set IRQTF_AFFINITY again and
1072 * try again next time
1073 */
1074 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1075 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1076 return;
1077 }
1078
1079 raw_spin_lock_irq(&desc->lock);
1080 /*
1081 * This code is triggered unconditionally. Check the affinity
1082 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1083 */
1084 if (cpumask_available(desc->irq_common_data.affinity)) {
1085 const struct cpumask *m;
1086
1087 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1088 cpumask_copy(mask, m);
1089 valid = true;
1090 }
1091 raw_spin_unlock_irq(&desc->lock);
1092
1093 if (valid)
1094 set_cpus_allowed_ptr(current, mask);
1095 free_cpumask_var(mask);
1096}
1097#else
1098static inline void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1099#endif
1100
1101static int irq_wait_for_interrupt(struct irq_desc *desc,
1102 struct irqaction *action)
1103{
1104 for (;;) {
1105 set_current_state(TASK_INTERRUPTIBLE);
1106 irq_thread_check_affinity(desc, action);
1107
1108 if (kthread_should_stop()) {
1109 /* may need to run one last time */
1110 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1111 &action->thread_flags)) {
1112 __set_current_state(TASK_RUNNING);
1113 return 0;
1114 }
1115 __set_current_state(TASK_RUNNING);
1116 return -1;
1117 }
1118
1119 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1120 &action->thread_flags)) {
1121 __set_current_state(TASK_RUNNING);
1122 return 0;
1123 }
1124 schedule();
1125 }
1126}
1127
1128/*
1129 * Oneshot interrupts keep the irq line masked until the threaded
1130 * handler finished. unmask if the interrupt has not been disabled and
1131 * is marked MASKED.
1132 */
1133static void irq_finalize_oneshot(struct irq_desc *desc,
1134 struct irqaction *action)
1135{
1136 if (!(desc->istate & IRQS_ONESHOT) ||
1137 action->handler == irq_forced_secondary_handler)
1138 return;
1139again:
1140 chip_bus_lock(desc);
1141 raw_spin_lock_irq(&desc->lock);
1142
1143 /*
1144 * Implausible though it may be we need to protect us against
1145 * the following scenario:
1146 *
1147 * The thread is faster done than the hard interrupt handler
1148 * on the other CPU. If we unmask the irq line then the
1149 * interrupt can come in again and masks the line, leaves due
1150 * to IRQS_INPROGRESS and the irq line is masked forever.
1151 *
1152 * This also serializes the state of shared oneshot handlers
1153 * versus "desc->threads_oneshot |= action->thread_mask;" in
1154 * irq_wake_thread(). See the comment there which explains the
1155 * serialization.
1156 */
1157 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1158 raw_spin_unlock_irq(&desc->lock);
1159 chip_bus_sync_unlock(desc);
1160 cpu_relax();
1161 goto again;
1162 }
1163
1164 /*
1165 * Now check again, whether the thread should run. Otherwise
1166 * we would clear the threads_oneshot bit of this thread which
1167 * was just set.
1168 */
1169 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1170 goto out_unlock;
1171
1172 desc->threads_oneshot &= ~action->thread_mask;
1173
1174 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1175 irqd_irq_masked(&desc->irq_data))
1176 unmask_threaded_irq(desc);
1177
1178out_unlock:
1179 raw_spin_unlock_irq(&desc->lock);
1180 chip_bus_sync_unlock(desc);
1181}
1182
1183/*
1184 * Interrupts which are not explicitly requested as threaded
1185 * interrupts rely on the implicit bh/preempt disable of the hard irq
1186 * context. So we need to disable bh here to avoid deadlocks and other
1187 * side effects.
1188 */
1189static irqreturn_t
1190irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1191{
1192 irqreturn_t ret;
1193
1194 local_bh_disable();
1195 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1196 local_irq_disable();
1197 ret = action->thread_fn(action->irq, action->dev_id);
1198 if (ret == IRQ_HANDLED)
1199 atomic_inc(&desc->threads_handled);
1200
1201 irq_finalize_oneshot(desc, action);
1202 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1203 local_irq_enable();
1204 local_bh_enable();
1205 return ret;
1206}
1207
1208/*
1209 * Interrupts explicitly requested as threaded interrupts want to be
1210 * preemptible - many of them need to sleep and wait for slow busses to
1211 * complete.
1212 */
1213static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1214 struct irqaction *action)
1215{
1216 irqreturn_t ret;
1217
1218 ret = action->thread_fn(action->irq, action->dev_id);
1219 if (ret == IRQ_HANDLED)
1220 atomic_inc(&desc->threads_handled);
1221
1222 irq_finalize_oneshot(desc, action);
1223 return ret;
1224}
1225
1226void wake_threads_waitq(struct irq_desc *desc)
1227{
1228 if (atomic_dec_and_test(&desc->threads_active))
1229 wake_up(&desc->wait_for_threads);
1230}
1231
1232static void irq_thread_dtor(struct callback_head *unused)
1233{
1234 struct task_struct *tsk = current;
1235 struct irq_desc *desc;
1236 struct irqaction *action;
1237
1238 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1239 return;
1240
1241 action = kthread_data(tsk);
1242
1243 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1244 tsk->comm, tsk->pid, action->irq);
1245
1246
1247 desc = irq_to_desc(action->irq);
1248 /*
1249 * If IRQTF_RUNTHREAD is set, we need to decrement
1250 * desc->threads_active and wake possible waiters.
1251 */
1252 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1253 wake_threads_waitq(desc);
1254
1255 /* Prevent a stale desc->threads_oneshot */
1256 irq_finalize_oneshot(desc, action);
1257}
1258
1259static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1260{
1261 struct irqaction *secondary = action->secondary;
1262
1263 if (WARN_ON_ONCE(!secondary))
1264 return;
1265
1266 raw_spin_lock_irq(&desc->lock);
1267 __irq_wake_thread(desc, secondary);
1268 raw_spin_unlock_irq(&desc->lock);
1269}
1270
1271/*
1272 * Internal function to notify that a interrupt thread is ready.
1273 */
1274static void irq_thread_set_ready(struct irq_desc *desc,
1275 struct irqaction *action)
1276{
1277 set_bit(IRQTF_READY, &action->thread_flags);
1278 wake_up(&desc->wait_for_threads);
1279}
1280
1281/*
1282 * Internal function to wake up a interrupt thread and wait until it is
1283 * ready.
1284 */
1285static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1286 struct irqaction *action)
1287{
1288 if (!action || !action->thread)
1289 return;
1290
1291 wake_up_process(action->thread);
1292 wait_event(desc->wait_for_threads,
1293 test_bit(IRQTF_READY, &action->thread_flags));
1294}
1295
1296/*
1297 * Interrupt handler thread
1298 */
1299static int irq_thread(void *data)
1300{
1301 struct callback_head on_exit_work;
1302 struct irqaction *action = data;
1303 struct irq_desc *desc = irq_to_desc(action->irq);
1304 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1305 struct irqaction *action);
1306
1307 irq_thread_set_ready(desc, action);
1308
1309 sched_set_fifo(current);
1310
1311 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1312 &action->thread_flags))
1313 handler_fn = irq_forced_thread_fn;
1314 else
1315 handler_fn = irq_thread_fn;
1316
1317 init_task_work(&on_exit_work, irq_thread_dtor);
1318 task_work_add(current, &on_exit_work, TWA_NONE);
1319
1320 while (!irq_wait_for_interrupt(desc, action)) {
1321 irqreturn_t action_ret;
1322
1323 action_ret = handler_fn(desc, action);
1324 if (action_ret == IRQ_WAKE_THREAD)
1325 irq_wake_secondary(desc, action);
1326
1327 wake_threads_waitq(desc);
1328 }
1329
1330 /*
1331 * This is the regular exit path. __free_irq() is stopping the
1332 * thread via kthread_stop() after calling
1333 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1334 * oneshot mask bit can be set.
1335 */
1336 task_work_cancel(current, irq_thread_dtor);
1337 return 0;
1338}
1339
1340/**
1341 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1342 * @irq: Interrupt line
1343 * @dev_id: Device identity for which the thread should be woken
1344 *
1345 */
1346void irq_wake_thread(unsigned int irq, void *dev_id)
1347{
1348 struct irq_desc *desc = irq_to_desc(irq);
1349 struct irqaction *action;
1350 unsigned long flags;
1351
1352 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1353 return;
1354
1355 raw_spin_lock_irqsave(&desc->lock, flags);
1356 for_each_action_of_desc(desc, action) {
1357 if (action->dev_id == dev_id) {
1358 if (action->thread)
1359 __irq_wake_thread(desc, action);
1360 break;
1361 }
1362 }
1363 raw_spin_unlock_irqrestore(&desc->lock, flags);
1364}
1365EXPORT_SYMBOL_GPL(irq_wake_thread);
1366
1367static int irq_setup_forced_threading(struct irqaction *new)
1368{
1369 if (!force_irqthreads())
1370 return 0;
1371 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1372 return 0;
1373
1374 /*
1375 * No further action required for interrupts which are requested as
1376 * threaded interrupts already
1377 */
1378 if (new->handler == irq_default_primary_handler)
1379 return 0;
1380
1381 new->flags |= IRQF_ONESHOT;
1382
1383 /*
1384 * Handle the case where we have a real primary handler and a
1385 * thread handler. We force thread them as well by creating a
1386 * secondary action.
1387 */
1388 if (new->handler && new->thread_fn) {
1389 /* Allocate the secondary action */
1390 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1391 if (!new->secondary)
1392 return -ENOMEM;
1393 new->secondary->handler = irq_forced_secondary_handler;
1394 new->secondary->thread_fn = new->thread_fn;
1395 new->secondary->dev_id = new->dev_id;
1396 new->secondary->irq = new->irq;
1397 new->secondary->name = new->name;
1398 }
1399 /* Deal with the primary handler */
1400 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1401 new->thread_fn = new->handler;
1402 new->handler = irq_default_primary_handler;
1403 return 0;
1404}
1405
1406static int irq_request_resources(struct irq_desc *desc)
1407{
1408 struct irq_data *d = &desc->irq_data;
1409 struct irq_chip *c = d->chip;
1410
1411 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1412}
1413
1414static void irq_release_resources(struct irq_desc *desc)
1415{
1416 struct irq_data *d = &desc->irq_data;
1417 struct irq_chip *c = d->chip;
1418
1419 if (c->irq_release_resources)
1420 c->irq_release_resources(d);
1421}
1422
1423static bool irq_supports_nmi(struct irq_desc *desc)
1424{
1425 struct irq_data *d = irq_desc_get_irq_data(desc);
1426
1427#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1428 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1429 if (d->parent_data)
1430 return false;
1431#endif
1432 /* Don't support NMIs for chips behind a slow bus */
1433 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1434 return false;
1435
1436 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1437}
1438
1439static int irq_nmi_setup(struct irq_desc *desc)
1440{
1441 struct irq_data *d = irq_desc_get_irq_data(desc);
1442 struct irq_chip *c = d->chip;
1443
1444 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1445}
1446
1447static void irq_nmi_teardown(struct irq_desc *desc)
1448{
1449 struct irq_data *d = irq_desc_get_irq_data(desc);
1450 struct irq_chip *c = d->chip;
1451
1452 if (c->irq_nmi_teardown)
1453 c->irq_nmi_teardown(d);
1454}
1455
1456static int
1457setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1458{
1459 struct task_struct *t;
1460
1461 if (!secondary) {
1462 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1463 new->name);
1464 } else {
1465 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1466 new->name);
1467 }
1468
1469 if (IS_ERR(t))
1470 return PTR_ERR(t);
1471
1472 /*
1473 * We keep the reference to the task struct even if
1474 * the thread dies to avoid that the interrupt code
1475 * references an already freed task_struct.
1476 */
1477 new->thread = get_task_struct(t);
1478 /*
1479 * Tell the thread to set its affinity. This is
1480 * important for shared interrupt handlers as we do
1481 * not invoke setup_affinity() for the secondary
1482 * handlers as everything is already set up. Even for
1483 * interrupts marked with IRQF_NO_BALANCE this is
1484 * correct as we want the thread to move to the cpu(s)
1485 * on which the requesting code placed the interrupt.
1486 */
1487 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1488 return 0;
1489}
1490
1491/*
1492 * Internal function to register an irqaction - typically used to
1493 * allocate special interrupts that are part of the architecture.
1494 *
1495 * Locking rules:
1496 *
1497 * desc->request_mutex Provides serialization against a concurrent free_irq()
1498 * chip_bus_lock Provides serialization for slow bus operations
1499 * desc->lock Provides serialization against hard interrupts
1500 *
1501 * chip_bus_lock and desc->lock are sufficient for all other management and
1502 * interrupt related functions. desc->request_mutex solely serializes
1503 * request/free_irq().
1504 */
1505static int
1506__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1507{
1508 struct irqaction *old, **old_ptr;
1509 unsigned long flags, thread_mask = 0;
1510 int ret, nested, shared = 0;
1511
1512 if (!desc)
1513 return -EINVAL;
1514
1515 if (desc->irq_data.chip == &no_irq_chip)
1516 return -ENOSYS;
1517 if (!try_module_get(desc->owner))
1518 return -ENODEV;
1519
1520 new->irq = irq;
1521
1522 /*
1523 * If the trigger type is not specified by the caller,
1524 * then use the default for this interrupt.
1525 */
1526 if (!(new->flags & IRQF_TRIGGER_MASK))
1527 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1528
1529 /*
1530 * Check whether the interrupt nests into another interrupt
1531 * thread.
1532 */
1533 nested = irq_settings_is_nested_thread(desc);
1534 if (nested) {
1535 if (!new->thread_fn) {
1536 ret = -EINVAL;
1537 goto out_mput;
1538 }
1539 /*
1540 * Replace the primary handler which was provided from
1541 * the driver for non nested interrupt handling by the
1542 * dummy function which warns when called.
1543 */
1544 new->handler = irq_nested_primary_handler;
1545 } else {
1546 if (irq_settings_can_thread(desc)) {
1547 ret = irq_setup_forced_threading(new);
1548 if (ret)
1549 goto out_mput;
1550 }
1551 }
1552
1553 /*
1554 * Create a handler thread when a thread function is supplied
1555 * and the interrupt does not nest into another interrupt
1556 * thread.
1557 */
1558 if (new->thread_fn && !nested) {
1559 ret = setup_irq_thread(new, irq, false);
1560 if (ret)
1561 goto out_mput;
1562 if (new->secondary) {
1563 ret = setup_irq_thread(new->secondary, irq, true);
1564 if (ret)
1565 goto out_thread;
1566 }
1567 }
1568
1569 /*
1570 * Drivers are often written to work w/o knowledge about the
1571 * underlying irq chip implementation, so a request for a
1572 * threaded irq without a primary hard irq context handler
1573 * requires the ONESHOT flag to be set. Some irq chips like
1574 * MSI based interrupts are per se one shot safe. Check the
1575 * chip flags, so we can avoid the unmask dance at the end of
1576 * the threaded handler for those.
1577 */
1578 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1579 new->flags &= ~IRQF_ONESHOT;
1580
1581 /*
1582 * Protects against a concurrent __free_irq() call which might wait
1583 * for synchronize_hardirq() to complete without holding the optional
1584 * chip bus lock and desc->lock. Also protects against handing out
1585 * a recycled oneshot thread_mask bit while it's still in use by
1586 * its previous owner.
1587 */
1588 mutex_lock(&desc->request_mutex);
1589
1590 /*
1591 * Acquire bus lock as the irq_request_resources() callback below
1592 * might rely on the serialization or the magic power management
1593 * functions which are abusing the irq_bus_lock() callback,
1594 */
1595 chip_bus_lock(desc);
1596
1597 /* First installed action requests resources. */
1598 if (!desc->action) {
1599 ret = irq_request_resources(desc);
1600 if (ret) {
1601 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1602 new->name, irq, desc->irq_data.chip->name);
1603 goto out_bus_unlock;
1604 }
1605 }
1606
1607 /*
1608 * The following block of code has to be executed atomically
1609 * protected against a concurrent interrupt and any of the other
1610 * management calls which are not serialized via
1611 * desc->request_mutex or the optional bus lock.
1612 */
1613 raw_spin_lock_irqsave(&desc->lock, flags);
1614 old_ptr = &desc->action;
1615 old = *old_ptr;
1616 if (old) {
1617 /*
1618 * Can't share interrupts unless both agree to and are
1619 * the same type (level, edge, polarity). So both flag
1620 * fields must have IRQF_SHARED set and the bits which
1621 * set the trigger type must match. Also all must
1622 * agree on ONESHOT.
1623 * Interrupt lines used for NMIs cannot be shared.
1624 */
1625 unsigned int oldtype;
1626
1627 if (desc->istate & IRQS_NMI) {
1628 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1629 new->name, irq, desc->irq_data.chip->name);
1630 ret = -EINVAL;
1631 goto out_unlock;
1632 }
1633
1634 /*
1635 * If nobody did set the configuration before, inherit
1636 * the one provided by the requester.
1637 */
1638 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1639 oldtype = irqd_get_trigger_type(&desc->irq_data);
1640 } else {
1641 oldtype = new->flags & IRQF_TRIGGER_MASK;
1642 irqd_set_trigger_type(&desc->irq_data, oldtype);
1643 }
1644
1645 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1646 (oldtype != (new->flags & IRQF_TRIGGER_MASK)))
1647 goto mismatch;
1648
1649 if ((old->flags & IRQF_ONESHOT) &&
1650 (new->flags & IRQF_COND_ONESHOT))
1651 new->flags |= IRQF_ONESHOT;
1652 else if ((old->flags ^ new->flags) & IRQF_ONESHOT)
1653 goto mismatch;
1654
1655 /* All handlers must agree on per-cpuness */
1656 if ((old->flags & IRQF_PERCPU) !=
1657 (new->flags & IRQF_PERCPU))
1658 goto mismatch;
1659
1660 /* add new interrupt at end of irq queue */
1661 do {
1662 /*
1663 * Or all existing action->thread_mask bits,
1664 * so we can find the next zero bit for this
1665 * new action.
1666 */
1667 thread_mask |= old->thread_mask;
1668 old_ptr = &old->next;
1669 old = *old_ptr;
1670 } while (old);
1671 shared = 1;
1672 }
1673
1674 /*
1675 * Setup the thread mask for this irqaction for ONESHOT. For
1676 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1677 * conditional in irq_wake_thread().
1678 */
1679 if (new->flags & IRQF_ONESHOT) {
1680 /*
1681 * Unlikely to have 32 resp 64 irqs sharing one line,
1682 * but who knows.
1683 */
1684 if (thread_mask == ~0UL) {
1685 ret = -EBUSY;
1686 goto out_unlock;
1687 }
1688 /*
1689 * The thread_mask for the action is or'ed to
1690 * desc->thread_active to indicate that the
1691 * IRQF_ONESHOT thread handler has been woken, but not
1692 * yet finished. The bit is cleared when a thread
1693 * completes. When all threads of a shared interrupt
1694 * line have completed desc->threads_active becomes
1695 * zero and the interrupt line is unmasked. See
1696 * handle.c:irq_wake_thread() for further information.
1697 *
1698 * If no thread is woken by primary (hard irq context)
1699 * interrupt handlers, then desc->threads_active is
1700 * also checked for zero to unmask the irq line in the
1701 * affected hard irq flow handlers
1702 * (handle_[fasteoi|level]_irq).
1703 *
1704 * The new action gets the first zero bit of
1705 * thread_mask assigned. See the loop above which or's
1706 * all existing action->thread_mask bits.
1707 */
1708 new->thread_mask = 1UL << ffz(thread_mask);
1709
1710 } else if (new->handler == irq_default_primary_handler &&
1711 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1712 /*
1713 * The interrupt was requested with handler = NULL, so
1714 * we use the default primary handler for it. But it
1715 * does not have the oneshot flag set. In combination
1716 * with level interrupts this is deadly, because the
1717 * default primary handler just wakes the thread, then
1718 * the irq lines is reenabled, but the device still
1719 * has the level irq asserted. Rinse and repeat....
1720 *
1721 * While this works for edge type interrupts, we play
1722 * it safe and reject unconditionally because we can't
1723 * say for sure which type this interrupt really
1724 * has. The type flags are unreliable as the
1725 * underlying chip implementation can override them.
1726 */
1727 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1728 new->name, irq);
1729 ret = -EINVAL;
1730 goto out_unlock;
1731 }
1732
1733 if (!shared) {
1734 /* Setup the type (level, edge polarity) if configured: */
1735 if (new->flags & IRQF_TRIGGER_MASK) {
1736 ret = __irq_set_trigger(desc,
1737 new->flags & IRQF_TRIGGER_MASK);
1738
1739 if (ret)
1740 goto out_unlock;
1741 }
1742
1743 /*
1744 * Activate the interrupt. That activation must happen
1745 * independently of IRQ_NOAUTOEN. request_irq() can fail
1746 * and the callers are supposed to handle
1747 * that. enable_irq() of an interrupt requested with
1748 * IRQ_NOAUTOEN is not supposed to fail. The activation
1749 * keeps it in shutdown mode, it merily associates
1750 * resources if necessary and if that's not possible it
1751 * fails. Interrupts which are in managed shutdown mode
1752 * will simply ignore that activation request.
1753 */
1754 ret = irq_activate(desc);
1755 if (ret)
1756 goto out_unlock;
1757
1758 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1759 IRQS_ONESHOT | IRQS_WAITING);
1760 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1761
1762 if (new->flags & IRQF_PERCPU) {
1763 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1764 irq_settings_set_per_cpu(desc);
1765 if (new->flags & IRQF_NO_DEBUG)
1766 irq_settings_set_no_debug(desc);
1767 }
1768
1769 if (noirqdebug)
1770 irq_settings_set_no_debug(desc);
1771
1772 if (new->flags & IRQF_ONESHOT)
1773 desc->istate |= IRQS_ONESHOT;
1774
1775 /* Exclude IRQ from balancing if requested */
1776 if (new->flags & IRQF_NOBALANCING) {
1777 irq_settings_set_no_balancing(desc);
1778 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1779 }
1780
1781 if (!(new->flags & IRQF_NO_AUTOEN) &&
1782 irq_settings_can_autoenable(desc)) {
1783 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1784 } else {
1785 /*
1786 * Shared interrupts do not go well with disabling
1787 * auto enable. The sharing interrupt might request
1788 * it while it's still disabled and then wait for
1789 * interrupts forever.
1790 */
1791 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1792 /* Undo nested disables: */
1793 desc->depth = 1;
1794 }
1795
1796 } else if (new->flags & IRQF_TRIGGER_MASK) {
1797 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1798 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1799
1800 if (nmsk != omsk)
1801 /* hope the handler works with current trigger mode */
1802 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1803 irq, omsk, nmsk);
1804 }
1805
1806 *old_ptr = new;
1807
1808 irq_pm_install_action(desc, new);
1809
1810 /* Reset broken irq detection when installing new handler */
1811 desc->irq_count = 0;
1812 desc->irqs_unhandled = 0;
1813
1814 /*
1815 * Check whether we disabled the irq via the spurious handler
1816 * before. Reenable it and give it another chance.
1817 */
1818 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1819 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1820 __enable_irq(desc);
1821 }
1822
1823 raw_spin_unlock_irqrestore(&desc->lock, flags);
1824 chip_bus_sync_unlock(desc);
1825 mutex_unlock(&desc->request_mutex);
1826
1827 irq_setup_timings(desc, new);
1828
1829 wake_up_and_wait_for_irq_thread_ready(desc, new);
1830 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1831
1832 register_irq_proc(irq, desc);
1833 new->dir = NULL;
1834 register_handler_proc(irq, new);
1835 return 0;
1836
1837mismatch:
1838 if (!(new->flags & IRQF_PROBE_SHARED)) {
1839 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1840 irq, new->flags, new->name, old->flags, old->name);
1841#ifdef CONFIG_DEBUG_SHIRQ
1842 dump_stack();
1843#endif
1844 }
1845 ret = -EBUSY;
1846
1847out_unlock:
1848 raw_spin_unlock_irqrestore(&desc->lock, flags);
1849
1850 if (!desc->action)
1851 irq_release_resources(desc);
1852out_bus_unlock:
1853 chip_bus_sync_unlock(desc);
1854 mutex_unlock(&desc->request_mutex);
1855
1856out_thread:
1857 if (new->thread) {
1858 struct task_struct *t = new->thread;
1859
1860 new->thread = NULL;
1861 kthread_stop_put(t);
1862 }
1863 if (new->secondary && new->secondary->thread) {
1864 struct task_struct *t = new->secondary->thread;
1865
1866 new->secondary->thread = NULL;
1867 kthread_stop_put(t);
1868 }
1869out_mput:
1870 module_put(desc->owner);
1871 return ret;
1872}
1873
1874/*
1875 * Internal function to unregister an irqaction - used to free
1876 * regular and special interrupts that are part of the architecture.
1877 */
1878static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1879{
1880 unsigned irq = desc->irq_data.irq;
1881 struct irqaction *action, **action_ptr;
1882 unsigned long flags;
1883
1884 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1885
1886 mutex_lock(&desc->request_mutex);
1887 chip_bus_lock(desc);
1888 raw_spin_lock_irqsave(&desc->lock, flags);
1889
1890 /*
1891 * There can be multiple actions per IRQ descriptor, find the right
1892 * one based on the dev_id:
1893 */
1894 action_ptr = &desc->action;
1895 for (;;) {
1896 action = *action_ptr;
1897
1898 if (!action) {
1899 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1900 raw_spin_unlock_irqrestore(&desc->lock, flags);
1901 chip_bus_sync_unlock(desc);
1902 mutex_unlock(&desc->request_mutex);
1903 return NULL;
1904 }
1905
1906 if (action->dev_id == dev_id)
1907 break;
1908 action_ptr = &action->next;
1909 }
1910
1911 /* Found it - now remove it from the list of entries: */
1912 *action_ptr = action->next;
1913
1914 irq_pm_remove_action(desc, action);
1915
1916 /* If this was the last handler, shut down the IRQ line: */
1917 if (!desc->action) {
1918 irq_settings_clr_disable_unlazy(desc);
1919 /* Only shutdown. Deactivate after synchronize_hardirq() */
1920 irq_shutdown(desc);
1921 }
1922
1923#ifdef CONFIG_SMP
1924 /* make sure affinity_hint is cleaned up */
1925 if (WARN_ON_ONCE(desc->affinity_hint))
1926 desc->affinity_hint = NULL;
1927#endif
1928
1929 raw_spin_unlock_irqrestore(&desc->lock, flags);
1930 /*
1931 * Drop bus_lock here so the changes which were done in the chip
1932 * callbacks above are synced out to the irq chips which hang
1933 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1934 *
1935 * Aside of that the bus_lock can also be taken from the threaded
1936 * handler in irq_finalize_oneshot() which results in a deadlock
1937 * because kthread_stop() would wait forever for the thread to
1938 * complete, which is blocked on the bus lock.
1939 *
1940 * The still held desc->request_mutex() protects against a
1941 * concurrent request_irq() of this irq so the release of resources
1942 * and timing data is properly serialized.
1943 */
1944 chip_bus_sync_unlock(desc);
1945
1946 unregister_handler_proc(irq, action);
1947
1948 /*
1949 * Make sure it's not being used on another CPU and if the chip
1950 * supports it also make sure that there is no (not yet serviced)
1951 * interrupt in flight at the hardware level.
1952 */
1953 __synchronize_irq(desc);
1954
1955#ifdef CONFIG_DEBUG_SHIRQ
1956 /*
1957 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1958 * event to happen even now it's being freed, so let's make sure that
1959 * is so by doing an extra call to the handler ....
1960 *
1961 * ( We do this after actually deregistering it, to make sure that a
1962 * 'real' IRQ doesn't run in parallel with our fake. )
1963 */
1964 if (action->flags & IRQF_SHARED) {
1965 local_irq_save(flags);
1966 action->handler(irq, dev_id);
1967 local_irq_restore(flags);
1968 }
1969#endif
1970
1971 /*
1972 * The action has already been removed above, but the thread writes
1973 * its oneshot mask bit when it completes. Though request_mutex is
1974 * held across this which prevents __setup_irq() from handing out
1975 * the same bit to a newly requested action.
1976 */
1977 if (action->thread) {
1978 kthread_stop_put(action->thread);
1979 if (action->secondary && action->secondary->thread)
1980 kthread_stop_put(action->secondary->thread);
1981 }
1982
1983 /* Last action releases resources */
1984 if (!desc->action) {
1985 /*
1986 * Reacquire bus lock as irq_release_resources() might
1987 * require it to deallocate resources over the slow bus.
1988 */
1989 chip_bus_lock(desc);
1990 /*
1991 * There is no interrupt on the fly anymore. Deactivate it
1992 * completely.
1993 */
1994 raw_spin_lock_irqsave(&desc->lock, flags);
1995 irq_domain_deactivate_irq(&desc->irq_data);
1996 raw_spin_unlock_irqrestore(&desc->lock, flags);
1997
1998 irq_release_resources(desc);
1999 chip_bus_sync_unlock(desc);
2000 irq_remove_timings(desc);
2001 }
2002
2003 mutex_unlock(&desc->request_mutex);
2004
2005 irq_chip_pm_put(&desc->irq_data);
2006 module_put(desc->owner);
2007 kfree(action->secondary);
2008 return action;
2009}
2010
2011/**
2012 * free_irq - free an interrupt allocated with request_irq
2013 * @irq: Interrupt line to free
2014 * @dev_id: Device identity to free
2015 *
2016 * Remove an interrupt handler. The handler is removed and if the
2017 * interrupt line is no longer in use by any driver it is disabled.
2018 * On a shared IRQ the caller must ensure the interrupt is disabled
2019 * on the card it drives before calling this function. The function
2020 * does not return until any executing interrupts for this IRQ
2021 * have completed.
2022 *
2023 * This function must not be called from interrupt context.
2024 *
2025 * Returns the devname argument passed to request_irq.
2026 */
2027const void *free_irq(unsigned int irq, void *dev_id)
2028{
2029 struct irq_desc *desc = irq_to_desc(irq);
2030 struct irqaction *action;
2031 const char *devname;
2032
2033 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2034 return NULL;
2035
2036#ifdef CONFIG_SMP
2037 if (WARN_ON(desc->affinity_notify))
2038 desc->affinity_notify = NULL;
2039#endif
2040
2041 action = __free_irq(desc, dev_id);
2042
2043 if (!action)
2044 return NULL;
2045
2046 devname = action->name;
2047 kfree(action);
2048 return devname;
2049}
2050EXPORT_SYMBOL(free_irq);
2051
2052/* This function must be called with desc->lock held */
2053static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2054{
2055 const char *devname = NULL;
2056
2057 desc->istate &= ~IRQS_NMI;
2058
2059 if (!WARN_ON(desc->action == NULL)) {
2060 irq_pm_remove_action(desc, desc->action);
2061 devname = desc->action->name;
2062 unregister_handler_proc(irq, desc->action);
2063
2064 kfree(desc->action);
2065 desc->action = NULL;
2066 }
2067
2068 irq_settings_clr_disable_unlazy(desc);
2069 irq_shutdown_and_deactivate(desc);
2070
2071 irq_release_resources(desc);
2072
2073 irq_chip_pm_put(&desc->irq_data);
2074 module_put(desc->owner);
2075
2076 return devname;
2077}
2078
2079const void *free_nmi(unsigned int irq, void *dev_id)
2080{
2081 struct irq_desc *desc = irq_to_desc(irq);
2082 unsigned long flags;
2083 const void *devname;
2084
2085 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2086 return NULL;
2087
2088 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2089 return NULL;
2090
2091 /* NMI still enabled */
2092 if (WARN_ON(desc->depth == 0))
2093 disable_nmi_nosync(irq);
2094
2095 raw_spin_lock_irqsave(&desc->lock, flags);
2096
2097 irq_nmi_teardown(desc);
2098 devname = __cleanup_nmi(irq, desc);
2099
2100 raw_spin_unlock_irqrestore(&desc->lock, flags);
2101
2102 return devname;
2103}
2104
2105/**
2106 * request_threaded_irq - allocate an interrupt line
2107 * @irq: Interrupt line to allocate
2108 * @handler: Function to be called when the IRQ occurs.
2109 * Primary handler for threaded interrupts.
2110 * If handler is NULL and thread_fn != NULL
2111 * the default primary handler is installed.
2112 * @thread_fn: Function called from the irq handler thread
2113 * If NULL, no irq thread is created
2114 * @irqflags: Interrupt type flags
2115 * @devname: An ascii name for the claiming device
2116 * @dev_id: A cookie passed back to the handler function
2117 *
2118 * This call allocates interrupt resources and enables the
2119 * interrupt line and IRQ handling. From the point this
2120 * call is made your handler function may be invoked. Since
2121 * your handler function must clear any interrupt the board
2122 * raises, you must take care both to initialise your hardware
2123 * and to set up the interrupt handler in the right order.
2124 *
2125 * If you want to set up a threaded irq handler for your device
2126 * then you need to supply @handler and @thread_fn. @handler is
2127 * still called in hard interrupt context and has to check
2128 * whether the interrupt originates from the device. If yes it
2129 * needs to disable the interrupt on the device and return
2130 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2131 * @thread_fn. This split handler design is necessary to support
2132 * shared interrupts.
2133 *
2134 * Dev_id must be globally unique. Normally the address of the
2135 * device data structure is used as the cookie. Since the handler
2136 * receives this value it makes sense to use it.
2137 *
2138 * If your interrupt is shared you must pass a non NULL dev_id
2139 * as this is required when freeing the interrupt.
2140 *
2141 * Flags:
2142 *
2143 * IRQF_SHARED Interrupt is shared
2144 * IRQF_TRIGGER_* Specify active edge(s) or level
2145 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2146 */
2147int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2148 irq_handler_t thread_fn, unsigned long irqflags,
2149 const char *devname, void *dev_id)
2150{
2151 struct irqaction *action;
2152 struct irq_desc *desc;
2153 int retval;
2154
2155 if (irq == IRQ_NOTCONNECTED)
2156 return -ENOTCONN;
2157
2158 /*
2159 * Sanity-check: shared interrupts must pass in a real dev-ID,
2160 * otherwise we'll have trouble later trying to figure out
2161 * which interrupt is which (messes up the interrupt freeing
2162 * logic etc).
2163 *
2164 * Also shared interrupts do not go well with disabling auto enable.
2165 * The sharing interrupt might request it while it's still disabled
2166 * and then wait for interrupts forever.
2167 *
2168 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2169 * it cannot be set along with IRQF_NO_SUSPEND.
2170 */
2171 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2172 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2173 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2174 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2175 return -EINVAL;
2176
2177 desc = irq_to_desc(irq);
2178 if (!desc)
2179 return -EINVAL;
2180
2181 if (!irq_settings_can_request(desc) ||
2182 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2183 return -EINVAL;
2184
2185 if (!handler) {
2186 if (!thread_fn)
2187 return -EINVAL;
2188 handler = irq_default_primary_handler;
2189 }
2190
2191 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2192 if (!action)
2193 return -ENOMEM;
2194
2195 action->handler = handler;
2196 action->thread_fn = thread_fn;
2197 action->flags = irqflags;
2198 action->name = devname;
2199 action->dev_id = dev_id;
2200
2201 retval = irq_chip_pm_get(&desc->irq_data);
2202 if (retval < 0) {
2203 kfree(action);
2204 return retval;
2205 }
2206
2207 retval = __setup_irq(irq, desc, action);
2208
2209 if (retval) {
2210 irq_chip_pm_put(&desc->irq_data);
2211 kfree(action->secondary);
2212 kfree(action);
2213 }
2214
2215#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2216 if (!retval && (irqflags & IRQF_SHARED)) {
2217 /*
2218 * It's a shared IRQ -- the driver ought to be prepared for it
2219 * to happen immediately, so let's make sure....
2220 * We disable the irq to make sure that a 'real' IRQ doesn't
2221 * run in parallel with our fake.
2222 */
2223 unsigned long flags;
2224
2225 disable_irq(irq);
2226 local_irq_save(flags);
2227
2228 handler(irq, dev_id);
2229
2230 local_irq_restore(flags);
2231 enable_irq(irq);
2232 }
2233#endif
2234 return retval;
2235}
2236EXPORT_SYMBOL(request_threaded_irq);
2237
2238/**
2239 * request_any_context_irq - allocate an interrupt line
2240 * @irq: Interrupt line to allocate
2241 * @handler: Function to be called when the IRQ occurs.
2242 * Threaded handler for threaded interrupts.
2243 * @flags: Interrupt type flags
2244 * @name: An ascii name for the claiming device
2245 * @dev_id: A cookie passed back to the handler function
2246 *
2247 * This call allocates interrupt resources and enables the
2248 * interrupt line and IRQ handling. It selects either a
2249 * hardirq or threaded handling method depending on the
2250 * context.
2251 *
2252 * On failure, it returns a negative value. On success,
2253 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2254 */
2255int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2256 unsigned long flags, const char *name, void *dev_id)
2257{
2258 struct irq_desc *desc;
2259 int ret;
2260
2261 if (irq == IRQ_NOTCONNECTED)
2262 return -ENOTCONN;
2263
2264 desc = irq_to_desc(irq);
2265 if (!desc)
2266 return -EINVAL;
2267
2268 if (irq_settings_is_nested_thread(desc)) {
2269 ret = request_threaded_irq(irq, NULL, handler,
2270 flags, name, dev_id);
2271 return !ret ? IRQC_IS_NESTED : ret;
2272 }
2273
2274 ret = request_irq(irq, handler, flags, name, dev_id);
2275 return !ret ? IRQC_IS_HARDIRQ : ret;
2276}
2277EXPORT_SYMBOL_GPL(request_any_context_irq);
2278
2279/**
2280 * request_nmi - allocate an interrupt line for NMI delivery
2281 * @irq: Interrupt line to allocate
2282 * @handler: Function to be called when the IRQ occurs.
2283 * Threaded handler for threaded interrupts.
2284 * @irqflags: Interrupt type flags
2285 * @name: An ascii name for the claiming device
2286 * @dev_id: A cookie passed back to the handler function
2287 *
2288 * This call allocates interrupt resources and enables the
2289 * interrupt line and IRQ handling. It sets up the IRQ line
2290 * to be handled as an NMI.
2291 *
2292 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2293 * cannot be threaded.
2294 *
2295 * Interrupt lines requested for NMI delivering must produce per cpu
2296 * interrupts and have auto enabling setting disabled.
2297 *
2298 * Dev_id must be globally unique. Normally the address of the
2299 * device data structure is used as the cookie. Since the handler
2300 * receives this value it makes sense to use it.
2301 *
2302 * If the interrupt line cannot be used to deliver NMIs, function
2303 * will fail and return a negative value.
2304 */
2305int request_nmi(unsigned int irq, irq_handler_t handler,
2306 unsigned long irqflags, const char *name, void *dev_id)
2307{
2308 struct irqaction *action;
2309 struct irq_desc *desc;
2310 unsigned long flags;
2311 int retval;
2312
2313 if (irq == IRQ_NOTCONNECTED)
2314 return -ENOTCONN;
2315
2316 /* NMI cannot be shared, used for Polling */
2317 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2318 return -EINVAL;
2319
2320 if (!(irqflags & IRQF_PERCPU))
2321 return -EINVAL;
2322
2323 if (!handler)
2324 return -EINVAL;
2325
2326 desc = irq_to_desc(irq);
2327
2328 if (!desc || (irq_settings_can_autoenable(desc) &&
2329 !(irqflags & IRQF_NO_AUTOEN)) ||
2330 !irq_settings_can_request(desc) ||
2331 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2332 !irq_supports_nmi(desc))
2333 return -EINVAL;
2334
2335 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2336 if (!action)
2337 return -ENOMEM;
2338
2339 action->handler = handler;
2340 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2341 action->name = name;
2342 action->dev_id = dev_id;
2343
2344 retval = irq_chip_pm_get(&desc->irq_data);
2345 if (retval < 0)
2346 goto err_out;
2347
2348 retval = __setup_irq(irq, desc, action);
2349 if (retval)
2350 goto err_irq_setup;
2351
2352 raw_spin_lock_irqsave(&desc->lock, flags);
2353
2354 /* Setup NMI state */
2355 desc->istate |= IRQS_NMI;
2356 retval = irq_nmi_setup(desc);
2357 if (retval) {
2358 __cleanup_nmi(irq, desc);
2359 raw_spin_unlock_irqrestore(&desc->lock, flags);
2360 return -EINVAL;
2361 }
2362
2363 raw_spin_unlock_irqrestore(&desc->lock, flags);
2364
2365 return 0;
2366
2367err_irq_setup:
2368 irq_chip_pm_put(&desc->irq_data);
2369err_out:
2370 kfree(action);
2371
2372 return retval;
2373}
2374
2375void enable_percpu_irq(unsigned int irq, unsigned int type)
2376{
2377 unsigned int cpu = smp_processor_id();
2378 unsigned long flags;
2379 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2380
2381 if (!desc)
2382 return;
2383
2384 /*
2385 * If the trigger type is not specified by the caller, then
2386 * use the default for this interrupt.
2387 */
2388 type &= IRQ_TYPE_SENSE_MASK;
2389 if (type == IRQ_TYPE_NONE)
2390 type = irqd_get_trigger_type(&desc->irq_data);
2391
2392 if (type != IRQ_TYPE_NONE) {
2393 int ret;
2394
2395 ret = __irq_set_trigger(desc, type);
2396
2397 if (ret) {
2398 WARN(1, "failed to set type for IRQ%d\n", irq);
2399 goto out;
2400 }
2401 }
2402
2403 irq_percpu_enable(desc, cpu);
2404out:
2405 irq_put_desc_unlock(desc, flags);
2406}
2407EXPORT_SYMBOL_GPL(enable_percpu_irq);
2408
2409void enable_percpu_nmi(unsigned int irq, unsigned int type)
2410{
2411 enable_percpu_irq(irq, type);
2412}
2413
2414/**
2415 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2416 * @irq: Linux irq number to check for
2417 *
2418 * Must be called from a non migratable context. Returns the enable
2419 * state of a per cpu interrupt on the current cpu.
2420 */
2421bool irq_percpu_is_enabled(unsigned int irq)
2422{
2423 unsigned int cpu = smp_processor_id();
2424 struct irq_desc *desc;
2425 unsigned long flags;
2426 bool is_enabled;
2427
2428 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2429 if (!desc)
2430 return false;
2431
2432 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2433 irq_put_desc_unlock(desc, flags);
2434
2435 return is_enabled;
2436}
2437EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2438
2439void disable_percpu_irq(unsigned int irq)
2440{
2441 unsigned int cpu = smp_processor_id();
2442 unsigned long flags;
2443 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2444
2445 if (!desc)
2446 return;
2447
2448 irq_percpu_disable(desc, cpu);
2449 irq_put_desc_unlock(desc, flags);
2450}
2451EXPORT_SYMBOL_GPL(disable_percpu_irq);
2452
2453void disable_percpu_nmi(unsigned int irq)
2454{
2455 disable_percpu_irq(irq);
2456}
2457
2458/*
2459 * Internal function to unregister a percpu irqaction.
2460 */
2461static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2462{
2463 struct irq_desc *desc = irq_to_desc(irq);
2464 struct irqaction *action;
2465 unsigned long flags;
2466
2467 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2468
2469 if (!desc)
2470 return NULL;
2471
2472 raw_spin_lock_irqsave(&desc->lock, flags);
2473
2474 action = desc->action;
2475 if (!action || action->percpu_dev_id != dev_id) {
2476 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2477 goto bad;
2478 }
2479
2480 if (!cpumask_empty(desc->percpu_enabled)) {
2481 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2482 irq, cpumask_first(desc->percpu_enabled));
2483 goto bad;
2484 }
2485
2486 /* Found it - now remove it from the list of entries: */
2487 desc->action = NULL;
2488
2489 desc->istate &= ~IRQS_NMI;
2490
2491 raw_spin_unlock_irqrestore(&desc->lock, flags);
2492
2493 unregister_handler_proc(irq, action);
2494
2495 irq_chip_pm_put(&desc->irq_data);
2496 module_put(desc->owner);
2497 return action;
2498
2499bad:
2500 raw_spin_unlock_irqrestore(&desc->lock, flags);
2501 return NULL;
2502}
2503
2504/**
2505 * remove_percpu_irq - free a per-cpu interrupt
2506 * @irq: Interrupt line to free
2507 * @act: irqaction for the interrupt
2508 *
2509 * Used to remove interrupts statically setup by the early boot process.
2510 */
2511void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2512{
2513 struct irq_desc *desc = irq_to_desc(irq);
2514
2515 if (desc && irq_settings_is_per_cpu_devid(desc))
2516 __free_percpu_irq(irq, act->percpu_dev_id);
2517}
2518
2519/**
2520 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2521 * @irq: Interrupt line to free
2522 * @dev_id: Device identity to free
2523 *
2524 * Remove a percpu interrupt handler. The handler is removed, but
2525 * the interrupt line is not disabled. This must be done on each
2526 * CPU before calling this function. The function does not return
2527 * until any executing interrupts for this IRQ have completed.
2528 *
2529 * This function must not be called from interrupt context.
2530 */
2531void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2532{
2533 struct irq_desc *desc = irq_to_desc(irq);
2534
2535 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2536 return;
2537
2538 chip_bus_lock(desc);
2539 kfree(__free_percpu_irq(irq, dev_id));
2540 chip_bus_sync_unlock(desc);
2541}
2542EXPORT_SYMBOL_GPL(free_percpu_irq);
2543
2544void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2545{
2546 struct irq_desc *desc = irq_to_desc(irq);
2547
2548 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2549 return;
2550
2551 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2552 return;
2553
2554 kfree(__free_percpu_irq(irq, dev_id));
2555}
2556
2557/**
2558 * setup_percpu_irq - setup a per-cpu interrupt
2559 * @irq: Interrupt line to setup
2560 * @act: irqaction for the interrupt
2561 *
2562 * Used to statically setup per-cpu interrupts in the early boot process.
2563 */
2564int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2565{
2566 struct irq_desc *desc = irq_to_desc(irq);
2567 int retval;
2568
2569 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2570 return -EINVAL;
2571
2572 retval = irq_chip_pm_get(&desc->irq_data);
2573 if (retval < 0)
2574 return retval;
2575
2576 retval = __setup_irq(irq, desc, act);
2577
2578 if (retval)
2579 irq_chip_pm_put(&desc->irq_data);
2580
2581 return retval;
2582}
2583
2584/**
2585 * __request_percpu_irq - allocate a percpu interrupt line
2586 * @irq: Interrupt line to allocate
2587 * @handler: Function to be called when the IRQ occurs.
2588 * @flags: Interrupt type flags (IRQF_TIMER only)
2589 * @devname: An ascii name for the claiming device
2590 * @dev_id: A percpu cookie passed back to the handler function
2591 *
2592 * This call allocates interrupt resources and enables the
2593 * interrupt on the local CPU. If the interrupt is supposed to be
2594 * enabled on other CPUs, it has to be done on each CPU using
2595 * enable_percpu_irq().
2596 *
2597 * Dev_id must be globally unique. It is a per-cpu variable, and
2598 * the handler gets called with the interrupted CPU's instance of
2599 * that variable.
2600 */
2601int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2602 unsigned long flags, const char *devname,
2603 void __percpu *dev_id)
2604{
2605 struct irqaction *action;
2606 struct irq_desc *desc;
2607 int retval;
2608
2609 if (!dev_id)
2610 return -EINVAL;
2611
2612 desc = irq_to_desc(irq);
2613 if (!desc || !irq_settings_can_request(desc) ||
2614 !irq_settings_is_per_cpu_devid(desc))
2615 return -EINVAL;
2616
2617 if (flags && flags != IRQF_TIMER)
2618 return -EINVAL;
2619
2620 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2621 if (!action)
2622 return -ENOMEM;
2623
2624 action->handler = handler;
2625 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2626 action->name = devname;
2627 action->percpu_dev_id = dev_id;
2628
2629 retval = irq_chip_pm_get(&desc->irq_data);
2630 if (retval < 0) {
2631 kfree(action);
2632 return retval;
2633 }
2634
2635 retval = __setup_irq(irq, desc, action);
2636
2637 if (retval) {
2638 irq_chip_pm_put(&desc->irq_data);
2639 kfree(action);
2640 }
2641
2642 return retval;
2643}
2644EXPORT_SYMBOL_GPL(__request_percpu_irq);
2645
2646/**
2647 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2648 * @irq: Interrupt line to allocate
2649 * @handler: Function to be called when the IRQ occurs.
2650 * @name: An ascii name for the claiming device
2651 * @dev_id: A percpu cookie passed back to the handler function
2652 *
2653 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2654 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2655 * being enabled on the same CPU by using enable_percpu_nmi().
2656 *
2657 * Dev_id must be globally unique. It is a per-cpu variable, and
2658 * the handler gets called with the interrupted CPU's instance of
2659 * that variable.
2660 *
2661 * Interrupt lines requested for NMI delivering should have auto enabling
2662 * setting disabled.
2663 *
2664 * If the interrupt line cannot be used to deliver NMIs, function
2665 * will fail returning a negative value.
2666 */
2667int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2668 const char *name, void __percpu *dev_id)
2669{
2670 struct irqaction *action;
2671 struct irq_desc *desc;
2672 unsigned long flags;
2673 int retval;
2674
2675 if (!handler)
2676 return -EINVAL;
2677
2678 desc = irq_to_desc(irq);
2679
2680 if (!desc || !irq_settings_can_request(desc) ||
2681 !irq_settings_is_per_cpu_devid(desc) ||
2682 irq_settings_can_autoenable(desc) ||
2683 !irq_supports_nmi(desc))
2684 return -EINVAL;
2685
2686 /* The line cannot already be NMI */
2687 if (desc->istate & IRQS_NMI)
2688 return -EINVAL;
2689
2690 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2691 if (!action)
2692 return -ENOMEM;
2693
2694 action->handler = handler;
2695 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2696 | IRQF_NOBALANCING;
2697 action->name = name;
2698 action->percpu_dev_id = dev_id;
2699
2700 retval = irq_chip_pm_get(&desc->irq_data);
2701 if (retval < 0)
2702 goto err_out;
2703
2704 retval = __setup_irq(irq, desc, action);
2705 if (retval)
2706 goto err_irq_setup;
2707
2708 raw_spin_lock_irqsave(&desc->lock, flags);
2709 desc->istate |= IRQS_NMI;
2710 raw_spin_unlock_irqrestore(&desc->lock, flags);
2711
2712 return 0;
2713
2714err_irq_setup:
2715 irq_chip_pm_put(&desc->irq_data);
2716err_out:
2717 kfree(action);
2718
2719 return retval;
2720}
2721
2722/**
2723 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2724 * @irq: Interrupt line to prepare for NMI delivery
2725 *
2726 * This call prepares an interrupt line to deliver NMI on the current CPU,
2727 * before that interrupt line gets enabled with enable_percpu_nmi().
2728 *
2729 * As a CPU local operation, this should be called from non-preemptible
2730 * context.
2731 *
2732 * If the interrupt line cannot be used to deliver NMIs, function
2733 * will fail returning a negative value.
2734 */
2735int prepare_percpu_nmi(unsigned int irq)
2736{
2737 unsigned long flags;
2738 struct irq_desc *desc;
2739 int ret = 0;
2740
2741 WARN_ON(preemptible());
2742
2743 desc = irq_get_desc_lock(irq, &flags,
2744 IRQ_GET_DESC_CHECK_PERCPU);
2745 if (!desc)
2746 return -EINVAL;
2747
2748 if (WARN(!(desc->istate & IRQS_NMI),
2749 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2750 irq)) {
2751 ret = -EINVAL;
2752 goto out;
2753 }
2754
2755 ret = irq_nmi_setup(desc);
2756 if (ret) {
2757 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2758 goto out;
2759 }
2760
2761out:
2762 irq_put_desc_unlock(desc, flags);
2763 return ret;
2764}
2765
2766/**
2767 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2768 * @irq: Interrupt line from which CPU local NMI configuration should be
2769 * removed
2770 *
2771 * This call undoes the setup done by prepare_percpu_nmi().
2772 *
2773 * IRQ line should not be enabled for the current CPU.
2774 *
2775 * As a CPU local operation, this should be called from non-preemptible
2776 * context.
2777 */
2778void teardown_percpu_nmi(unsigned int irq)
2779{
2780 unsigned long flags;
2781 struct irq_desc *desc;
2782
2783 WARN_ON(preemptible());
2784
2785 desc = irq_get_desc_lock(irq, &flags,
2786 IRQ_GET_DESC_CHECK_PERCPU);
2787 if (!desc)
2788 return;
2789
2790 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2791 goto out;
2792
2793 irq_nmi_teardown(desc);
2794out:
2795 irq_put_desc_unlock(desc, flags);
2796}
2797
2798int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2799 bool *state)
2800{
2801 struct irq_chip *chip;
2802 int err = -EINVAL;
2803
2804 do {
2805 chip = irq_data_get_irq_chip(data);
2806 if (WARN_ON_ONCE(!chip))
2807 return -ENODEV;
2808 if (chip->irq_get_irqchip_state)
2809 break;
2810#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2811 data = data->parent_data;
2812#else
2813 data = NULL;
2814#endif
2815 } while (data);
2816
2817 if (data)
2818 err = chip->irq_get_irqchip_state(data, which, state);
2819 return err;
2820}
2821
2822/**
2823 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2824 * @irq: Interrupt line that is forwarded to a VM
2825 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2826 * @state: a pointer to a boolean where the state is to be stored
2827 *
2828 * This call snapshots the internal irqchip state of an
2829 * interrupt, returning into @state the bit corresponding to
2830 * stage @which
2831 *
2832 * This function should be called with preemption disabled if the
2833 * interrupt controller has per-cpu registers.
2834 */
2835int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2836 bool *state)
2837{
2838 struct irq_desc *desc;
2839 struct irq_data *data;
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 err = __irq_get_irqchip_state(data, which, state);
2850
2851 irq_put_desc_busunlock(desc, flags);
2852 return err;
2853}
2854EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2855
2856/**
2857 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2858 * @irq: Interrupt line that is forwarded to a VM
2859 * @which: State to be restored (one of IRQCHIP_STATE_*)
2860 * @val: Value corresponding to @which
2861 *
2862 * This call sets the internal irqchip state of an interrupt,
2863 * depending on the value of @which.
2864 *
2865 * This function should be called with migration disabled if the
2866 * interrupt controller has per-cpu registers.
2867 */
2868int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2869 bool val)
2870{
2871 struct irq_desc *desc;
2872 struct irq_data *data;
2873 struct irq_chip *chip;
2874 unsigned long flags;
2875 int err = -EINVAL;
2876
2877 desc = irq_get_desc_buslock(irq, &flags, 0);
2878 if (!desc)
2879 return err;
2880
2881 data = irq_desc_get_irq_data(desc);
2882
2883 do {
2884 chip = irq_data_get_irq_chip(data);
2885 if (WARN_ON_ONCE(!chip)) {
2886 err = -ENODEV;
2887 goto out_unlock;
2888 }
2889 if (chip->irq_set_irqchip_state)
2890 break;
2891#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2892 data = data->parent_data;
2893#else
2894 data = NULL;
2895#endif
2896 } while (data);
2897
2898 if (data)
2899 err = chip->irq_set_irqchip_state(data, which, val);
2900
2901out_unlock:
2902 irq_put_desc_busunlock(desc, flags);
2903 return err;
2904}
2905EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2906
2907/**
2908 * irq_has_action - Check whether an interrupt is requested
2909 * @irq: The linux irq number
2910 *
2911 * Returns: A snapshot of the current state
2912 */
2913bool irq_has_action(unsigned int irq)
2914{
2915 bool res;
2916
2917 rcu_read_lock();
2918 res = irq_desc_has_action(irq_to_desc(irq));
2919 rcu_read_unlock();
2920 return res;
2921}
2922EXPORT_SYMBOL_GPL(irq_has_action);
2923
2924/**
2925 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2926 * @irq: The linux irq number
2927 * @bitmask: The bitmask to evaluate
2928 *
2929 * Returns: True if one of the bits in @bitmask is set
2930 */
2931bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2932{
2933 struct irq_desc *desc;
2934 bool res = false;
2935
2936 rcu_read_lock();
2937 desc = irq_to_desc(irq);
2938 if (desc)
2939 res = !!(desc->status_use_accessors & bitmask);
2940 rcu_read_unlock();
2941 return res;
2942}
2943EXPORT_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)
28DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
29
30static int __init setup_forced_irqthreads(char *arg)
31{
32 static_branch_enable(&force_irqthreads_key);
33 return 0;
34}
35early_param("threadirqs", setup_forced_irqthreads);
36#endif
37
38static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
39{
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
41 bool inprogress;
42
43 do {
44 unsigned long flags;
45
46 /*
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
49 */
50 while (irqd_irq_inprogress(&desc->irq_data))
51 cpu_relax();
52
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
56
57 /*
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
61 */
62 if (!inprogress && sync_chip) {
63 /*
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
66 */
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
68 &inprogress);
69 }
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
71
72 /* Oops, that failed? */
73 } while (inprogress);
74}
75
76/**
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
79 *
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
84 * into account.
85 *
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
88 *
89 * Returns: false if a threaded handler is active.
90 *
91 * This function may be called - with care - from IRQ context.
92 *
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
96 * is the current CPU.
97 */
98bool synchronize_hardirq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
105 }
106
107 return true;
108}
109EXPORT_SYMBOL(synchronize_hardirq);
110
111static void __synchronize_irq(struct irq_desc *desc)
112{
113 __synchronize_hardirq(desc, true);
114 /*
115 * We made sure that no hardirq handler is running. Now verify that no
116 * threaded handlers are active.
117 */
118 wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
119}
120
121/**
122 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
123 * @irq: interrupt number to wait for
124 *
125 * This function waits for any pending IRQ handlers for this interrupt
126 * to complete before returning. If you use this function while
127 * holding a resource the IRQ handler may need you will deadlock.
128 *
129 * Can only be called from preemptible code as it might sleep when
130 * an interrupt thread is associated to @irq.
131 *
132 * It optionally makes sure (when the irq chip supports that method)
133 * that the interrupt is not pending in any CPU and waiting for
134 * service.
135 */
136void synchronize_irq(unsigned int irq)
137{
138 struct irq_desc *desc = irq_to_desc(irq);
139
140 if (desc)
141 __synchronize_irq(desc);
142}
143EXPORT_SYMBOL(synchronize_irq);
144
145#ifdef CONFIG_SMP
146cpumask_var_t irq_default_affinity;
147
148static bool __irq_can_set_affinity(struct irq_desc *desc)
149{
150 if (!desc || !irqd_can_balance(&desc->irq_data) ||
151 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
152 return false;
153 return true;
154}
155
156/**
157 * irq_can_set_affinity - Check if the affinity of a given irq can be set
158 * @irq: Interrupt to check
159 *
160 */
161int irq_can_set_affinity(unsigned int irq)
162{
163 return __irq_can_set_affinity(irq_to_desc(irq));
164}
165
166/**
167 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
168 * @irq: Interrupt to check
169 *
170 * Like irq_can_set_affinity() above, but additionally checks for the
171 * AFFINITY_MANAGED flag.
172 */
173bool irq_can_set_affinity_usr(unsigned int irq)
174{
175 struct irq_desc *desc = irq_to_desc(irq);
176
177 return __irq_can_set_affinity(desc) &&
178 !irqd_affinity_is_managed(&desc->irq_data);
179}
180
181/**
182 * irq_set_thread_affinity - Notify irq threads to adjust affinity
183 * @desc: irq descriptor which has affinity changed
184 *
185 * We just set IRQTF_AFFINITY and delegate the affinity setting
186 * to the interrupt thread itself. We can not call
187 * set_cpus_allowed_ptr() here as we hold desc->lock and this
188 * code can be called from hard interrupt context.
189 */
190void irq_set_thread_affinity(struct irq_desc *desc)
191{
192 struct irqaction *action;
193
194 for_each_action_of_desc(desc, action) {
195 if (action->thread)
196 set_bit(IRQTF_AFFINITY, &action->thread_flags);
197 if (action->secondary && action->secondary->thread)
198 set_bit(IRQTF_AFFINITY, &action->secondary->thread_flags);
199 }
200}
201
202#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
203static void irq_validate_effective_affinity(struct irq_data *data)
204{
205 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
206 struct irq_chip *chip = irq_data_get_irq_chip(data);
207
208 if (!cpumask_empty(m))
209 return;
210 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
211 chip->name, data->irq);
212}
213#else
214static inline void irq_validate_effective_affinity(struct irq_data *data) { }
215#endif
216
217int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
218 bool force)
219{
220 struct irq_desc *desc = irq_data_to_desc(data);
221 struct irq_chip *chip = irq_data_get_irq_chip(data);
222 const struct cpumask *prog_mask;
223 int ret;
224
225 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
226 static struct cpumask tmp_mask;
227
228 if (!chip || !chip->irq_set_affinity)
229 return -EINVAL;
230
231 raw_spin_lock(&tmp_mask_lock);
232 /*
233 * If this is a managed interrupt and housekeeping is enabled on
234 * it check whether the requested affinity mask intersects with
235 * a housekeeping CPU. If so, then remove the isolated CPUs from
236 * the mask and just keep the housekeeping CPU(s). This prevents
237 * the affinity setter from routing the interrupt to an isolated
238 * CPU to avoid that I/O submitted from a housekeeping CPU causes
239 * interrupts on an isolated one.
240 *
241 * If the masks do not intersect or include online CPU(s) then
242 * keep the requested mask. The isolated target CPUs are only
243 * receiving interrupts when the I/O operation was submitted
244 * directly from them.
245 *
246 * If all housekeeping CPUs in the affinity mask are offline, the
247 * interrupt will be migrated by the CPU hotplug code once a
248 * housekeeping CPU which belongs to the affinity mask comes
249 * online.
250 */
251 if (irqd_affinity_is_managed(data) &&
252 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
253 const struct cpumask *hk_mask;
254
255 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
256
257 cpumask_and(&tmp_mask, mask, hk_mask);
258 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
259 prog_mask = mask;
260 else
261 prog_mask = &tmp_mask;
262 } else {
263 prog_mask = mask;
264 }
265
266 /*
267 * Make sure we only provide online CPUs to the irqchip,
268 * unless we are being asked to force the affinity (in which
269 * case we do as we are told).
270 */
271 cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
272 if (!force && !cpumask_empty(&tmp_mask))
273 ret = chip->irq_set_affinity(data, &tmp_mask, force);
274 else if (force)
275 ret = chip->irq_set_affinity(data, mask, force);
276 else
277 ret = -EINVAL;
278
279 raw_spin_unlock(&tmp_mask_lock);
280
281 switch (ret) {
282 case IRQ_SET_MASK_OK:
283 case IRQ_SET_MASK_OK_DONE:
284 cpumask_copy(desc->irq_common_data.affinity, mask);
285 fallthrough;
286 case IRQ_SET_MASK_OK_NOCOPY:
287 irq_validate_effective_affinity(data);
288 irq_set_thread_affinity(desc);
289 ret = 0;
290 }
291
292 return ret;
293}
294
295#ifdef CONFIG_GENERIC_PENDING_IRQ
296static inline int irq_set_affinity_pending(struct irq_data *data,
297 const struct cpumask *dest)
298{
299 struct irq_desc *desc = irq_data_to_desc(data);
300
301 irqd_set_move_pending(data);
302 irq_copy_pending(desc, dest);
303 return 0;
304}
305#else
306static inline int irq_set_affinity_pending(struct irq_data *data,
307 const struct cpumask *dest)
308{
309 return -EBUSY;
310}
311#endif
312
313static int irq_try_set_affinity(struct irq_data *data,
314 const struct cpumask *dest, bool force)
315{
316 int ret = irq_do_set_affinity(data, dest, force);
317
318 /*
319 * In case that the underlying vector management is busy and the
320 * architecture supports the generic pending mechanism then utilize
321 * this to avoid returning an error to user space.
322 */
323 if (ret == -EBUSY && !force)
324 ret = irq_set_affinity_pending(data, dest);
325 return ret;
326}
327
328static bool irq_set_affinity_deactivated(struct irq_data *data,
329 const struct cpumask *mask)
330{
331 struct irq_desc *desc = irq_data_to_desc(data);
332
333 /*
334 * Handle irq chips which can handle affinity only in activated
335 * state correctly
336 *
337 * If the interrupt is not yet activated, just store the affinity
338 * mask and do not call the chip driver at all. On activation the
339 * driver has to make sure anyway that the interrupt is in a
340 * usable state so startup works.
341 */
342 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
343 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
344 return false;
345
346 cpumask_copy(desc->irq_common_data.affinity, mask);
347 irq_data_update_effective_affinity(data, mask);
348 irqd_set(data, IRQD_AFFINITY_SET);
349 return true;
350}
351
352int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
353 bool force)
354{
355 struct irq_chip *chip = irq_data_get_irq_chip(data);
356 struct irq_desc *desc = irq_data_to_desc(data);
357 int ret = 0;
358
359 if (!chip || !chip->irq_set_affinity)
360 return -EINVAL;
361
362 if (irq_set_affinity_deactivated(data, mask))
363 return 0;
364
365 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
366 ret = irq_try_set_affinity(data, mask, force);
367 } else {
368 irqd_set_move_pending(data);
369 irq_copy_pending(desc, mask);
370 }
371
372 if (desc->affinity_notify) {
373 kref_get(&desc->affinity_notify->kref);
374 if (!schedule_work(&desc->affinity_notify->work)) {
375 /* Work was already scheduled, drop our extra ref */
376 kref_put(&desc->affinity_notify->kref,
377 desc->affinity_notify->release);
378 }
379 }
380 irqd_set(data, IRQD_AFFINITY_SET);
381
382 return ret;
383}
384
385/**
386 * irq_update_affinity_desc - Update affinity management for an interrupt
387 * @irq: The interrupt number to update
388 * @affinity: Pointer to the affinity descriptor
389 *
390 * This interface can be used to configure the affinity management of
391 * interrupts which have been allocated already.
392 *
393 * There are certain limitations on when it may be used - attempts to use it
394 * for when the kernel is configured for generic IRQ reservation mode (in
395 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
396 * managed/non-managed interrupt accounting. In addition, attempts to use it on
397 * an interrupt which is already started or which has already been configured
398 * as managed will also fail, as these mean invalid init state or double init.
399 */
400int irq_update_affinity_desc(unsigned int irq,
401 struct irq_affinity_desc *affinity)
402{
403 struct irq_desc *desc;
404 unsigned long flags;
405 bool activated;
406 int ret = 0;
407
408 /*
409 * Supporting this with the reservation scheme used by x86 needs
410 * some more thought. Fail it for now.
411 */
412 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
413 return -EOPNOTSUPP;
414
415 desc = irq_get_desc_buslock(irq, &flags, 0);
416 if (!desc)
417 return -EINVAL;
418
419 /* Requires the interrupt to be shut down */
420 if (irqd_is_started(&desc->irq_data)) {
421 ret = -EBUSY;
422 goto out_unlock;
423 }
424
425 /* Interrupts which are already managed cannot be modified */
426 if (irqd_affinity_is_managed(&desc->irq_data)) {
427 ret = -EBUSY;
428 goto out_unlock;
429 }
430
431 /*
432 * Deactivate the interrupt. That's required to undo
433 * anything an earlier activation has established.
434 */
435 activated = irqd_is_activated(&desc->irq_data);
436 if (activated)
437 irq_domain_deactivate_irq(&desc->irq_data);
438
439 if (affinity->is_managed) {
440 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
441 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
442 }
443
444 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
445
446 /* Restore the activation state */
447 if (activated)
448 irq_domain_activate_irq(&desc->irq_data, false);
449
450out_unlock:
451 irq_put_desc_busunlock(desc, flags);
452 return ret;
453}
454
455static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
456 bool force)
457{
458 struct irq_desc *desc = irq_to_desc(irq);
459 unsigned long flags;
460 int ret;
461
462 if (!desc)
463 return -EINVAL;
464
465 raw_spin_lock_irqsave(&desc->lock, flags);
466 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
467 raw_spin_unlock_irqrestore(&desc->lock, flags);
468 return ret;
469}
470
471/**
472 * irq_set_affinity - Set the irq affinity of a given irq
473 * @irq: Interrupt to set affinity
474 * @cpumask: cpumask
475 *
476 * Fails if cpumask does not contain an online CPU
477 */
478int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
479{
480 return __irq_set_affinity(irq, cpumask, false);
481}
482EXPORT_SYMBOL_GPL(irq_set_affinity);
483
484/**
485 * irq_force_affinity - Force the irq affinity of a given irq
486 * @irq: Interrupt to set affinity
487 * @cpumask: cpumask
488 *
489 * Same as irq_set_affinity, but without checking the mask against
490 * online cpus.
491 *
492 * Solely for low level cpu hotplug code, where we need to make per
493 * cpu interrupts affine before the cpu becomes online.
494 */
495int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
496{
497 return __irq_set_affinity(irq, cpumask, true);
498}
499EXPORT_SYMBOL_GPL(irq_force_affinity);
500
501int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
502 bool setaffinity)
503{
504 unsigned long flags;
505 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
506
507 if (!desc)
508 return -EINVAL;
509 desc->affinity_hint = m;
510 irq_put_desc_unlock(desc, flags);
511 if (m && setaffinity)
512 __irq_set_affinity(irq, m, false);
513 return 0;
514}
515EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
516
517static void irq_affinity_notify(struct work_struct *work)
518{
519 struct irq_affinity_notify *notify =
520 container_of(work, struct irq_affinity_notify, work);
521 struct irq_desc *desc = irq_to_desc(notify->irq);
522 cpumask_var_t cpumask;
523 unsigned long flags;
524
525 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
526 goto out;
527
528 raw_spin_lock_irqsave(&desc->lock, flags);
529 if (irq_move_pending(&desc->irq_data))
530 irq_get_pending(cpumask, desc);
531 else
532 cpumask_copy(cpumask, desc->irq_common_data.affinity);
533 raw_spin_unlock_irqrestore(&desc->lock, flags);
534
535 notify->notify(notify, cpumask);
536
537 free_cpumask_var(cpumask);
538out:
539 kref_put(¬ify->kref, notify->release);
540}
541
542/**
543 * irq_set_affinity_notifier - control notification of IRQ affinity changes
544 * @irq: Interrupt for which to enable/disable notification
545 * @notify: Context for notification, or %NULL to disable
546 * notification. Function pointers must be initialised;
547 * the other fields will be initialised by this function.
548 *
549 * Must be called in process context. Notification may only be enabled
550 * after the IRQ is allocated and must be disabled before the IRQ is
551 * freed using free_irq().
552 */
553int
554irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
555{
556 struct irq_desc *desc = irq_to_desc(irq);
557 struct irq_affinity_notify *old_notify;
558 unsigned long flags;
559
560 /* The release function is promised process context */
561 might_sleep();
562
563 if (!desc || desc->istate & IRQS_NMI)
564 return -EINVAL;
565
566 /* Complete initialisation of *notify */
567 if (notify) {
568 notify->irq = irq;
569 kref_init(¬ify->kref);
570 INIT_WORK(¬ify->work, irq_affinity_notify);
571 }
572
573 raw_spin_lock_irqsave(&desc->lock, flags);
574 old_notify = desc->affinity_notify;
575 desc->affinity_notify = notify;
576 raw_spin_unlock_irqrestore(&desc->lock, flags);
577
578 if (old_notify) {
579 if (cancel_work_sync(&old_notify->work)) {
580 /* Pending work had a ref, put that one too */
581 kref_put(&old_notify->kref, old_notify->release);
582 }
583 kref_put(&old_notify->kref, old_notify->release);
584 }
585
586 return 0;
587}
588EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
589
590#ifndef CONFIG_AUTO_IRQ_AFFINITY
591/*
592 * Generic version of the affinity autoselector.
593 */
594int irq_setup_affinity(struct irq_desc *desc)
595{
596 struct cpumask *set = irq_default_affinity;
597 int ret, node = irq_desc_get_node(desc);
598 static DEFINE_RAW_SPINLOCK(mask_lock);
599 static struct cpumask mask;
600
601 /* Excludes PER_CPU and NO_BALANCE interrupts */
602 if (!__irq_can_set_affinity(desc))
603 return 0;
604
605 raw_spin_lock(&mask_lock);
606 /*
607 * Preserve the managed affinity setting and a userspace affinity
608 * setup, but make sure that one of the targets is online.
609 */
610 if (irqd_affinity_is_managed(&desc->irq_data) ||
611 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
612 if (cpumask_intersects(desc->irq_common_data.affinity,
613 cpu_online_mask))
614 set = desc->irq_common_data.affinity;
615 else
616 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
617 }
618
619 cpumask_and(&mask, cpu_online_mask, set);
620 if (cpumask_empty(&mask))
621 cpumask_copy(&mask, cpu_online_mask);
622
623 if (node != NUMA_NO_NODE) {
624 const struct cpumask *nodemask = cpumask_of_node(node);
625
626 /* make sure at least one of the cpus in nodemask is online */
627 if (cpumask_intersects(&mask, nodemask))
628 cpumask_and(&mask, &mask, nodemask);
629 }
630 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
631 raw_spin_unlock(&mask_lock);
632 return ret;
633}
634#else
635/* Wrapper for ALPHA specific affinity selector magic */
636int irq_setup_affinity(struct irq_desc *desc)
637{
638 return irq_select_affinity(irq_desc_get_irq(desc));
639}
640#endif /* CONFIG_AUTO_IRQ_AFFINITY */
641#endif /* CONFIG_SMP */
642
643
644/**
645 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
646 * @irq: interrupt number to set affinity
647 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
648 * specific data for percpu_devid interrupts
649 *
650 * This function uses the vCPU specific data to set the vCPU
651 * affinity for an irq. The vCPU specific data is passed from
652 * outside, such as KVM. One example code path is as below:
653 * KVM -> IOMMU -> irq_set_vcpu_affinity().
654 */
655int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
656{
657 unsigned long flags;
658 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
659 struct irq_data *data;
660 struct irq_chip *chip;
661 int ret = -ENOSYS;
662
663 if (!desc)
664 return -EINVAL;
665
666 data = irq_desc_get_irq_data(desc);
667 do {
668 chip = irq_data_get_irq_chip(data);
669 if (chip && chip->irq_set_vcpu_affinity)
670 break;
671#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
672 data = data->parent_data;
673#else
674 data = NULL;
675#endif
676 } while (data);
677
678 if (data)
679 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
680 irq_put_desc_unlock(desc, flags);
681
682 return ret;
683}
684EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
685
686void __disable_irq(struct irq_desc *desc)
687{
688 if (!desc->depth++)
689 irq_disable(desc);
690}
691
692static int __disable_irq_nosync(unsigned int irq)
693{
694 unsigned long flags;
695 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
696
697 if (!desc)
698 return -EINVAL;
699 __disable_irq(desc);
700 irq_put_desc_busunlock(desc, flags);
701 return 0;
702}
703
704/**
705 * disable_irq_nosync - disable an irq without waiting
706 * @irq: Interrupt to disable
707 *
708 * Disable the selected interrupt line. Disables and Enables are
709 * nested.
710 * Unlike disable_irq(), this function does not ensure existing
711 * instances of the IRQ handler have completed before returning.
712 *
713 * This function may be called from IRQ context.
714 */
715void disable_irq_nosync(unsigned int irq)
716{
717 __disable_irq_nosync(irq);
718}
719EXPORT_SYMBOL(disable_irq_nosync);
720
721/**
722 * disable_irq - disable an irq and wait for completion
723 * @irq: Interrupt to disable
724 *
725 * Disable the selected interrupt line. Enables and Disables are
726 * nested.
727 * This function waits for any pending IRQ handlers for this interrupt
728 * to complete before returning. If you use this function while
729 * holding a resource the IRQ handler may need you will deadlock.
730 *
731 * Can only be called from preemptible code as it might sleep when
732 * an interrupt thread is associated to @irq.
733 *
734 */
735void disable_irq(unsigned int irq)
736{
737 might_sleep();
738 if (!__disable_irq_nosync(irq))
739 synchronize_irq(irq);
740}
741EXPORT_SYMBOL(disable_irq);
742
743/**
744 * disable_hardirq - disables an irq and waits for hardirq completion
745 * @irq: Interrupt to disable
746 *
747 * Disable the selected interrupt line. Enables and Disables are
748 * nested.
749 * This function waits for any pending hard IRQ handlers for this
750 * interrupt to complete before returning. If you use this function while
751 * holding a resource the hard IRQ handler may need you will deadlock.
752 *
753 * When used to optimistically disable an interrupt from atomic context
754 * the return value must be checked.
755 *
756 * Returns: false if a threaded handler is active.
757 *
758 * This function may be called - with care - from IRQ context.
759 */
760bool disable_hardirq(unsigned int irq)
761{
762 if (!__disable_irq_nosync(irq))
763 return synchronize_hardirq(irq);
764
765 return false;
766}
767EXPORT_SYMBOL_GPL(disable_hardirq);
768
769/**
770 * disable_nmi_nosync - disable an nmi without waiting
771 * @irq: Interrupt to disable
772 *
773 * Disable the selected interrupt line. Disables and enables are
774 * nested.
775 * The interrupt to disable must have been requested through request_nmi.
776 * Unlike disable_nmi(), this function does not ensure existing
777 * instances of the IRQ handler have completed before returning.
778 */
779void disable_nmi_nosync(unsigned int irq)
780{
781 disable_irq_nosync(irq);
782}
783
784void __enable_irq(struct irq_desc *desc)
785{
786 switch (desc->depth) {
787 case 0:
788 err_out:
789 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
790 irq_desc_get_irq(desc));
791 break;
792 case 1: {
793 if (desc->istate & IRQS_SUSPENDED)
794 goto err_out;
795 /* Prevent probing on this irq: */
796 irq_settings_set_noprobe(desc);
797 /*
798 * Call irq_startup() not irq_enable() here because the
799 * interrupt might be marked NOAUTOEN. So irq_startup()
800 * needs to be invoked when it gets enabled the first
801 * time. If it was already started up, then irq_startup()
802 * will invoke irq_enable() under the hood.
803 */
804 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
805 break;
806 }
807 default:
808 desc->depth--;
809 }
810}
811
812/**
813 * enable_irq - enable handling of an irq
814 * @irq: Interrupt to enable
815 *
816 * Undoes the effect of one call to disable_irq(). If this
817 * matches the last disable, processing of interrupts on this
818 * IRQ line is re-enabled.
819 *
820 * This function may be called from IRQ context only when
821 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
822 */
823void enable_irq(unsigned int irq)
824{
825 unsigned long flags;
826 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
827
828 if (!desc)
829 return;
830 if (WARN(!desc->irq_data.chip,
831 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
832 goto out;
833
834 __enable_irq(desc);
835out:
836 irq_put_desc_busunlock(desc, flags);
837}
838EXPORT_SYMBOL(enable_irq);
839
840/**
841 * enable_nmi - enable handling of an nmi
842 * @irq: Interrupt to enable
843 *
844 * The interrupt to enable must have been requested through request_nmi.
845 * Undoes the effect of one call to disable_nmi(). If this
846 * matches the last disable, processing of interrupts on this
847 * IRQ line is re-enabled.
848 */
849void enable_nmi(unsigned int irq)
850{
851 enable_irq(irq);
852}
853
854static int set_irq_wake_real(unsigned int irq, unsigned int on)
855{
856 struct irq_desc *desc = irq_to_desc(irq);
857 int ret = -ENXIO;
858
859 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
860 return 0;
861
862 if (desc->irq_data.chip->irq_set_wake)
863 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
864
865 return ret;
866}
867
868/**
869 * irq_set_irq_wake - control irq power management wakeup
870 * @irq: interrupt to control
871 * @on: enable/disable power management wakeup
872 *
873 * Enable/disable power management wakeup mode, which is
874 * disabled by default. Enables and disables must match,
875 * just as they match for non-wakeup mode support.
876 *
877 * Wakeup mode lets this IRQ wake the system from sleep
878 * states like "suspend to RAM".
879 *
880 * Note: irq enable/disable state is completely orthogonal
881 * to the enable/disable state of irq wake. An irq can be
882 * disabled with disable_irq() and still wake the system as
883 * long as the irq has wake enabled. If this does not hold,
884 * then the underlying irq chip and the related driver need
885 * to be investigated.
886 */
887int irq_set_irq_wake(unsigned int irq, unsigned int on)
888{
889 unsigned long flags;
890 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
891 int ret = 0;
892
893 if (!desc)
894 return -EINVAL;
895
896 /* Don't use NMIs as wake up interrupts please */
897 if (desc->istate & IRQS_NMI) {
898 ret = -EINVAL;
899 goto out_unlock;
900 }
901
902 /* wakeup-capable irqs can be shared between drivers that
903 * don't need to have the same sleep mode behaviors.
904 */
905 if (on) {
906 if (desc->wake_depth++ == 0) {
907 ret = set_irq_wake_real(irq, on);
908 if (ret)
909 desc->wake_depth = 0;
910 else
911 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
912 }
913 } else {
914 if (desc->wake_depth == 0) {
915 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
916 } else if (--desc->wake_depth == 0) {
917 ret = set_irq_wake_real(irq, on);
918 if (ret)
919 desc->wake_depth = 1;
920 else
921 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
922 }
923 }
924
925out_unlock:
926 irq_put_desc_busunlock(desc, flags);
927 return ret;
928}
929EXPORT_SYMBOL(irq_set_irq_wake);
930
931/*
932 * Internal function that tells the architecture code whether a
933 * particular irq has been exclusively allocated or is available
934 * for driver use.
935 */
936int can_request_irq(unsigned int irq, unsigned long irqflags)
937{
938 unsigned long flags;
939 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
940 int canrequest = 0;
941
942 if (!desc)
943 return 0;
944
945 if (irq_settings_can_request(desc)) {
946 if (!desc->action ||
947 irqflags & desc->action->flags & IRQF_SHARED)
948 canrequest = 1;
949 }
950 irq_put_desc_unlock(desc, flags);
951 return canrequest;
952}
953
954int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
955{
956 struct irq_chip *chip = desc->irq_data.chip;
957 int ret, unmask = 0;
958
959 if (!chip || !chip->irq_set_type) {
960 /*
961 * IRQF_TRIGGER_* but the PIC does not support multiple
962 * flow-types?
963 */
964 pr_debug("No set_type function for IRQ %d (%s)\n",
965 irq_desc_get_irq(desc),
966 chip ? (chip->name ? : "unknown") : "unknown");
967 return 0;
968 }
969
970 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
971 if (!irqd_irq_masked(&desc->irq_data))
972 mask_irq(desc);
973 if (!irqd_irq_disabled(&desc->irq_data))
974 unmask = 1;
975 }
976
977 /* Mask all flags except trigger mode */
978 flags &= IRQ_TYPE_SENSE_MASK;
979 ret = chip->irq_set_type(&desc->irq_data, flags);
980
981 switch (ret) {
982 case IRQ_SET_MASK_OK:
983 case IRQ_SET_MASK_OK_DONE:
984 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
985 irqd_set(&desc->irq_data, flags);
986 fallthrough;
987
988 case IRQ_SET_MASK_OK_NOCOPY:
989 flags = irqd_get_trigger_type(&desc->irq_data);
990 irq_settings_set_trigger_mask(desc, flags);
991 irqd_clear(&desc->irq_data, IRQD_LEVEL);
992 irq_settings_clr_level(desc);
993 if (flags & IRQ_TYPE_LEVEL_MASK) {
994 irq_settings_set_level(desc);
995 irqd_set(&desc->irq_data, IRQD_LEVEL);
996 }
997
998 ret = 0;
999 break;
1000 default:
1001 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
1002 flags, irq_desc_get_irq(desc), chip->irq_set_type);
1003 }
1004 if (unmask)
1005 unmask_irq(desc);
1006 return ret;
1007}
1008
1009#ifdef CONFIG_HARDIRQS_SW_RESEND
1010int irq_set_parent(int irq, int parent_irq)
1011{
1012 unsigned long flags;
1013 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1014
1015 if (!desc)
1016 return -EINVAL;
1017
1018 desc->parent_irq = parent_irq;
1019
1020 irq_put_desc_unlock(desc, flags);
1021 return 0;
1022}
1023EXPORT_SYMBOL_GPL(irq_set_parent);
1024#endif
1025
1026/*
1027 * Default primary interrupt handler for threaded interrupts. Is
1028 * assigned as primary handler when request_threaded_irq is called
1029 * with handler == NULL. Useful for oneshot interrupts.
1030 */
1031static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1032{
1033 return IRQ_WAKE_THREAD;
1034}
1035
1036/*
1037 * Primary handler for nested threaded interrupts. Should never be
1038 * called.
1039 */
1040static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1041{
1042 WARN(1, "Primary handler called for nested irq %d\n", irq);
1043 return IRQ_NONE;
1044}
1045
1046static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1047{
1048 WARN(1, "Secondary action handler called for irq %d\n", irq);
1049 return IRQ_NONE;
1050}
1051
1052static int irq_wait_for_interrupt(struct irqaction *action)
1053{
1054 for (;;) {
1055 set_current_state(TASK_INTERRUPTIBLE);
1056
1057 if (kthread_should_stop()) {
1058 /* may need to run one last time */
1059 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1060 &action->thread_flags)) {
1061 __set_current_state(TASK_RUNNING);
1062 return 0;
1063 }
1064 __set_current_state(TASK_RUNNING);
1065 return -1;
1066 }
1067
1068 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1069 &action->thread_flags)) {
1070 __set_current_state(TASK_RUNNING);
1071 return 0;
1072 }
1073 schedule();
1074 }
1075}
1076
1077/*
1078 * Oneshot interrupts keep the irq line masked until the threaded
1079 * handler finished. unmask if the interrupt has not been disabled and
1080 * is marked MASKED.
1081 */
1082static void irq_finalize_oneshot(struct irq_desc *desc,
1083 struct irqaction *action)
1084{
1085 if (!(desc->istate & IRQS_ONESHOT) ||
1086 action->handler == irq_forced_secondary_handler)
1087 return;
1088again:
1089 chip_bus_lock(desc);
1090 raw_spin_lock_irq(&desc->lock);
1091
1092 /*
1093 * Implausible though it may be we need to protect us against
1094 * the following scenario:
1095 *
1096 * The thread is faster done than the hard interrupt handler
1097 * on the other CPU. If we unmask the irq line then the
1098 * interrupt can come in again and masks the line, leaves due
1099 * to IRQS_INPROGRESS and the irq line is masked forever.
1100 *
1101 * This also serializes the state of shared oneshot handlers
1102 * versus "desc->threads_oneshot |= action->thread_mask;" in
1103 * irq_wake_thread(). See the comment there which explains the
1104 * serialization.
1105 */
1106 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1107 raw_spin_unlock_irq(&desc->lock);
1108 chip_bus_sync_unlock(desc);
1109 cpu_relax();
1110 goto again;
1111 }
1112
1113 /*
1114 * Now check again, whether the thread should run. Otherwise
1115 * we would clear the threads_oneshot bit of this thread which
1116 * was just set.
1117 */
1118 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1119 goto out_unlock;
1120
1121 desc->threads_oneshot &= ~action->thread_mask;
1122
1123 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1124 irqd_irq_masked(&desc->irq_data))
1125 unmask_threaded_irq(desc);
1126
1127out_unlock:
1128 raw_spin_unlock_irq(&desc->lock);
1129 chip_bus_sync_unlock(desc);
1130}
1131
1132#ifdef CONFIG_SMP
1133/*
1134 * Check whether we need to change the affinity of the interrupt thread.
1135 */
1136static void
1137irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1138{
1139 cpumask_var_t mask;
1140 bool valid = true;
1141
1142 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1143 return;
1144
1145 /*
1146 * In case we are out of memory we set IRQTF_AFFINITY again and
1147 * try again next time
1148 */
1149 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1150 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1151 return;
1152 }
1153
1154 raw_spin_lock_irq(&desc->lock);
1155 /*
1156 * This code is triggered unconditionally. Check the affinity
1157 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1158 */
1159 if (cpumask_available(desc->irq_common_data.affinity)) {
1160 const struct cpumask *m;
1161
1162 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1163 cpumask_copy(mask, m);
1164 } else {
1165 valid = false;
1166 }
1167 raw_spin_unlock_irq(&desc->lock);
1168
1169 if (valid)
1170 set_cpus_allowed_ptr(current, mask);
1171 free_cpumask_var(mask);
1172}
1173#else
1174static inline void
1175irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1176#endif
1177
1178/*
1179 * Interrupts which are not explicitly requested as threaded
1180 * interrupts rely on the implicit bh/preempt disable of the hard irq
1181 * context. So we need to disable bh here to avoid deadlocks and other
1182 * side effects.
1183 */
1184static irqreturn_t
1185irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1186{
1187 irqreturn_t ret;
1188
1189 local_bh_disable();
1190 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1191 local_irq_disable();
1192 ret = action->thread_fn(action->irq, action->dev_id);
1193 if (ret == IRQ_HANDLED)
1194 atomic_inc(&desc->threads_handled);
1195
1196 irq_finalize_oneshot(desc, action);
1197 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1198 local_irq_enable();
1199 local_bh_enable();
1200 return ret;
1201}
1202
1203/*
1204 * Interrupts explicitly requested as threaded interrupts want to be
1205 * preemptible - many of them need to sleep and wait for slow busses to
1206 * complete.
1207 */
1208static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1209 struct irqaction *action)
1210{
1211 irqreturn_t ret;
1212
1213 ret = action->thread_fn(action->irq, action->dev_id);
1214 if (ret == IRQ_HANDLED)
1215 atomic_inc(&desc->threads_handled);
1216
1217 irq_finalize_oneshot(desc, action);
1218 return ret;
1219}
1220
1221void wake_threads_waitq(struct irq_desc *desc)
1222{
1223 if (atomic_dec_and_test(&desc->threads_active))
1224 wake_up(&desc->wait_for_threads);
1225}
1226
1227static void irq_thread_dtor(struct callback_head *unused)
1228{
1229 struct task_struct *tsk = current;
1230 struct irq_desc *desc;
1231 struct irqaction *action;
1232
1233 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1234 return;
1235
1236 action = kthread_data(tsk);
1237
1238 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1239 tsk->comm, tsk->pid, action->irq);
1240
1241
1242 desc = irq_to_desc(action->irq);
1243 /*
1244 * If IRQTF_RUNTHREAD is set, we need to decrement
1245 * desc->threads_active and wake possible waiters.
1246 */
1247 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1248 wake_threads_waitq(desc);
1249
1250 /* Prevent a stale desc->threads_oneshot */
1251 irq_finalize_oneshot(desc, action);
1252}
1253
1254static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1255{
1256 struct irqaction *secondary = action->secondary;
1257
1258 if (WARN_ON_ONCE(!secondary))
1259 return;
1260
1261 raw_spin_lock_irq(&desc->lock);
1262 __irq_wake_thread(desc, secondary);
1263 raw_spin_unlock_irq(&desc->lock);
1264}
1265
1266/*
1267 * Internal function to notify that a interrupt thread is ready.
1268 */
1269static void irq_thread_set_ready(struct irq_desc *desc,
1270 struct irqaction *action)
1271{
1272 set_bit(IRQTF_READY, &action->thread_flags);
1273 wake_up(&desc->wait_for_threads);
1274}
1275
1276/*
1277 * Internal function to wake up a interrupt thread and wait until it is
1278 * ready.
1279 */
1280static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1281 struct irqaction *action)
1282{
1283 if (!action || !action->thread)
1284 return;
1285
1286 wake_up_process(action->thread);
1287 wait_event(desc->wait_for_threads,
1288 test_bit(IRQTF_READY, &action->thread_flags));
1289}
1290
1291/*
1292 * Interrupt handler thread
1293 */
1294static int irq_thread(void *data)
1295{
1296 struct callback_head on_exit_work;
1297 struct irqaction *action = data;
1298 struct irq_desc *desc = irq_to_desc(action->irq);
1299 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1300 struct irqaction *action);
1301
1302 irq_thread_set_ready(desc, action);
1303
1304 sched_set_fifo(current);
1305
1306 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1307 &action->thread_flags))
1308 handler_fn = irq_forced_thread_fn;
1309 else
1310 handler_fn = irq_thread_fn;
1311
1312 init_task_work(&on_exit_work, irq_thread_dtor);
1313 task_work_add(current, &on_exit_work, TWA_NONE);
1314
1315 irq_thread_check_affinity(desc, action);
1316
1317 while (!irq_wait_for_interrupt(action)) {
1318 irqreturn_t action_ret;
1319
1320 irq_thread_check_affinity(desc, action);
1321
1322 action_ret = handler_fn(desc, action);
1323 if (action_ret == IRQ_WAKE_THREAD)
1324 irq_wake_secondary(desc, action);
1325
1326 wake_threads_waitq(desc);
1327 }
1328
1329 /*
1330 * This is the regular exit path. __free_irq() is stopping the
1331 * thread via kthread_stop() after calling
1332 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1333 * oneshot mask bit can be set.
1334 */
1335 task_work_cancel(current, irq_thread_dtor);
1336 return 0;
1337}
1338
1339/**
1340 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1341 * @irq: Interrupt line
1342 * @dev_id: Device identity for which the thread should be woken
1343 *
1344 */
1345void irq_wake_thread(unsigned int irq, void *dev_id)
1346{
1347 struct irq_desc *desc = irq_to_desc(irq);
1348 struct irqaction *action;
1349 unsigned long flags;
1350
1351 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1352 return;
1353
1354 raw_spin_lock_irqsave(&desc->lock, flags);
1355 for_each_action_of_desc(desc, action) {
1356 if (action->dev_id == dev_id) {
1357 if (action->thread)
1358 __irq_wake_thread(desc, action);
1359 break;
1360 }
1361 }
1362 raw_spin_unlock_irqrestore(&desc->lock, flags);
1363}
1364EXPORT_SYMBOL_GPL(irq_wake_thread);
1365
1366static int irq_setup_forced_threading(struct irqaction *new)
1367{
1368 if (!force_irqthreads())
1369 return 0;
1370 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1371 return 0;
1372
1373 /*
1374 * No further action required for interrupts which are requested as
1375 * threaded interrupts already
1376 */
1377 if (new->handler == irq_default_primary_handler)
1378 return 0;
1379
1380 new->flags |= IRQF_ONESHOT;
1381
1382 /*
1383 * Handle the case where we have a real primary handler and a
1384 * thread handler. We force thread them as well by creating a
1385 * secondary action.
1386 */
1387 if (new->handler && new->thread_fn) {
1388 /* Allocate the secondary action */
1389 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1390 if (!new->secondary)
1391 return -ENOMEM;
1392 new->secondary->handler = irq_forced_secondary_handler;
1393 new->secondary->thread_fn = new->thread_fn;
1394 new->secondary->dev_id = new->dev_id;
1395 new->secondary->irq = new->irq;
1396 new->secondary->name = new->name;
1397 }
1398 /* Deal with the primary handler */
1399 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1400 new->thread_fn = new->handler;
1401 new->handler = irq_default_primary_handler;
1402 return 0;
1403}
1404
1405static int irq_request_resources(struct irq_desc *desc)
1406{
1407 struct irq_data *d = &desc->irq_data;
1408 struct irq_chip *c = d->chip;
1409
1410 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1411}
1412
1413static void irq_release_resources(struct irq_desc *desc)
1414{
1415 struct irq_data *d = &desc->irq_data;
1416 struct irq_chip *c = d->chip;
1417
1418 if (c->irq_release_resources)
1419 c->irq_release_resources(d);
1420}
1421
1422static bool irq_supports_nmi(struct irq_desc *desc)
1423{
1424 struct irq_data *d = irq_desc_get_irq_data(desc);
1425
1426#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1427 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1428 if (d->parent_data)
1429 return false;
1430#endif
1431 /* Don't support NMIs for chips behind a slow bus */
1432 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1433 return false;
1434
1435 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1436}
1437
1438static int irq_nmi_setup(struct irq_desc *desc)
1439{
1440 struct irq_data *d = irq_desc_get_irq_data(desc);
1441 struct irq_chip *c = d->chip;
1442
1443 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1444}
1445
1446static void irq_nmi_teardown(struct irq_desc *desc)
1447{
1448 struct irq_data *d = irq_desc_get_irq_data(desc);
1449 struct irq_chip *c = d->chip;
1450
1451 if (c->irq_nmi_teardown)
1452 c->irq_nmi_teardown(d);
1453}
1454
1455static int
1456setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1457{
1458 struct task_struct *t;
1459
1460 if (!secondary) {
1461 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1462 new->name);
1463 } else {
1464 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1465 new->name);
1466 }
1467
1468 if (IS_ERR(t))
1469 return PTR_ERR(t);
1470
1471 /*
1472 * We keep the reference to the task struct even if
1473 * the thread dies to avoid that the interrupt code
1474 * references an already freed task_struct.
1475 */
1476 new->thread = get_task_struct(t);
1477 /*
1478 * Tell the thread to set its affinity. This is
1479 * important for shared interrupt handlers as we do
1480 * not invoke setup_affinity() for the secondary
1481 * handlers as everything is already set up. Even for
1482 * interrupts marked with IRQF_NO_BALANCE this is
1483 * correct as we want the thread to move to the cpu(s)
1484 * on which the requesting code placed the interrupt.
1485 */
1486 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1487 return 0;
1488}
1489
1490/*
1491 * Internal function to register an irqaction - typically used to
1492 * allocate special interrupts that are part of the architecture.
1493 *
1494 * Locking rules:
1495 *
1496 * desc->request_mutex Provides serialization against a concurrent free_irq()
1497 * chip_bus_lock Provides serialization for slow bus operations
1498 * desc->lock Provides serialization against hard interrupts
1499 *
1500 * chip_bus_lock and desc->lock are sufficient for all other management and
1501 * interrupt related functions. desc->request_mutex solely serializes
1502 * request/free_irq().
1503 */
1504static int
1505__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1506{
1507 struct irqaction *old, **old_ptr;
1508 unsigned long flags, thread_mask = 0;
1509 int ret, nested, shared = 0;
1510
1511 if (!desc)
1512 return -EINVAL;
1513
1514 if (desc->irq_data.chip == &no_irq_chip)
1515 return -ENOSYS;
1516 if (!try_module_get(desc->owner))
1517 return -ENODEV;
1518
1519 new->irq = irq;
1520
1521 /*
1522 * If the trigger type is not specified by the caller,
1523 * then use the default for this interrupt.
1524 */
1525 if (!(new->flags & IRQF_TRIGGER_MASK))
1526 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1527
1528 /*
1529 * Check whether the interrupt nests into another interrupt
1530 * thread.
1531 */
1532 nested = irq_settings_is_nested_thread(desc);
1533 if (nested) {
1534 if (!new->thread_fn) {
1535 ret = -EINVAL;
1536 goto out_mput;
1537 }
1538 /*
1539 * Replace the primary handler which was provided from
1540 * the driver for non nested interrupt handling by the
1541 * dummy function which warns when called.
1542 */
1543 new->handler = irq_nested_primary_handler;
1544 } else {
1545 if (irq_settings_can_thread(desc)) {
1546 ret = irq_setup_forced_threading(new);
1547 if (ret)
1548 goto out_mput;
1549 }
1550 }
1551
1552 /*
1553 * Create a handler thread when a thread function is supplied
1554 * and the interrupt does not nest into another interrupt
1555 * thread.
1556 */
1557 if (new->thread_fn && !nested) {
1558 ret = setup_irq_thread(new, irq, false);
1559 if (ret)
1560 goto out_mput;
1561 if (new->secondary) {
1562 ret = setup_irq_thread(new->secondary, irq, true);
1563 if (ret)
1564 goto out_thread;
1565 }
1566 }
1567
1568 /*
1569 * Drivers are often written to work w/o knowledge about the
1570 * underlying irq chip implementation, so a request for a
1571 * threaded irq without a primary hard irq context handler
1572 * requires the ONESHOT flag to be set. Some irq chips like
1573 * MSI based interrupts are per se one shot safe. Check the
1574 * chip flags, so we can avoid the unmask dance at the end of
1575 * the threaded handler for those.
1576 */
1577 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1578 new->flags &= ~IRQF_ONESHOT;
1579
1580 /*
1581 * Protects against a concurrent __free_irq() call which might wait
1582 * for synchronize_hardirq() to complete without holding the optional
1583 * chip bus lock and desc->lock. Also protects against handing out
1584 * a recycled oneshot thread_mask bit while it's still in use by
1585 * its previous owner.
1586 */
1587 mutex_lock(&desc->request_mutex);
1588
1589 /*
1590 * Acquire bus lock as the irq_request_resources() callback below
1591 * might rely on the serialization or the magic power management
1592 * functions which are abusing the irq_bus_lock() callback,
1593 */
1594 chip_bus_lock(desc);
1595
1596 /* First installed action requests resources. */
1597 if (!desc->action) {
1598 ret = irq_request_resources(desc);
1599 if (ret) {
1600 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1601 new->name, irq, desc->irq_data.chip->name);
1602 goto out_bus_unlock;
1603 }
1604 }
1605
1606 /*
1607 * The following block of code has to be executed atomically
1608 * protected against a concurrent interrupt and any of the other
1609 * management calls which are not serialized via
1610 * desc->request_mutex or the optional bus lock.
1611 */
1612 raw_spin_lock_irqsave(&desc->lock, flags);
1613 old_ptr = &desc->action;
1614 old = *old_ptr;
1615 if (old) {
1616 /*
1617 * Can't share interrupts unless both agree to and are
1618 * the same type (level, edge, polarity). So both flag
1619 * fields must have IRQF_SHARED set and the bits which
1620 * set the trigger type must match. Also all must
1621 * agree on ONESHOT.
1622 * Interrupt lines used for NMIs cannot be shared.
1623 */
1624 unsigned int oldtype;
1625
1626 if (desc->istate & IRQS_NMI) {
1627 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1628 new->name, irq, desc->irq_data.chip->name);
1629 ret = -EINVAL;
1630 goto out_unlock;
1631 }
1632
1633 /*
1634 * If nobody did set the configuration before, inherit
1635 * the one provided by the requester.
1636 */
1637 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1638 oldtype = irqd_get_trigger_type(&desc->irq_data);
1639 } else {
1640 oldtype = new->flags & IRQF_TRIGGER_MASK;
1641 irqd_set_trigger_type(&desc->irq_data, oldtype);
1642 }
1643
1644 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1645 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1646 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1647 goto mismatch;
1648
1649 /* All handlers must agree on per-cpuness */
1650 if ((old->flags & IRQF_PERCPU) !=
1651 (new->flags & IRQF_PERCPU))
1652 goto mismatch;
1653
1654 /* add new interrupt at end of irq queue */
1655 do {
1656 /*
1657 * Or all existing action->thread_mask bits,
1658 * so we can find the next zero bit for this
1659 * new action.
1660 */
1661 thread_mask |= old->thread_mask;
1662 old_ptr = &old->next;
1663 old = *old_ptr;
1664 } while (old);
1665 shared = 1;
1666 }
1667
1668 /*
1669 * Setup the thread mask for this irqaction for ONESHOT. For
1670 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1671 * conditional in irq_wake_thread().
1672 */
1673 if (new->flags & IRQF_ONESHOT) {
1674 /*
1675 * Unlikely to have 32 resp 64 irqs sharing one line,
1676 * but who knows.
1677 */
1678 if (thread_mask == ~0UL) {
1679 ret = -EBUSY;
1680 goto out_unlock;
1681 }
1682 /*
1683 * The thread_mask for the action is or'ed to
1684 * desc->thread_active to indicate that the
1685 * IRQF_ONESHOT thread handler has been woken, but not
1686 * yet finished. The bit is cleared when a thread
1687 * completes. When all threads of a shared interrupt
1688 * line have completed desc->threads_active becomes
1689 * zero and the interrupt line is unmasked. See
1690 * handle.c:irq_wake_thread() for further information.
1691 *
1692 * If no thread is woken by primary (hard irq context)
1693 * interrupt handlers, then desc->threads_active is
1694 * also checked for zero to unmask the irq line in the
1695 * affected hard irq flow handlers
1696 * (handle_[fasteoi|level]_irq).
1697 *
1698 * The new action gets the first zero bit of
1699 * thread_mask assigned. See the loop above which or's
1700 * all existing action->thread_mask bits.
1701 */
1702 new->thread_mask = 1UL << ffz(thread_mask);
1703
1704 } else if (new->handler == irq_default_primary_handler &&
1705 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1706 /*
1707 * The interrupt was requested with handler = NULL, so
1708 * we use the default primary handler for it. But it
1709 * does not have the oneshot flag set. In combination
1710 * with level interrupts this is deadly, because the
1711 * default primary handler just wakes the thread, then
1712 * the irq lines is reenabled, but the device still
1713 * has the level irq asserted. Rinse and repeat....
1714 *
1715 * While this works for edge type interrupts, we play
1716 * it safe and reject unconditionally because we can't
1717 * say for sure which type this interrupt really
1718 * has. The type flags are unreliable as the
1719 * underlying chip implementation can override them.
1720 */
1721 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1722 new->name, irq);
1723 ret = -EINVAL;
1724 goto out_unlock;
1725 }
1726
1727 if (!shared) {
1728 /* Setup the type (level, edge polarity) if configured: */
1729 if (new->flags & IRQF_TRIGGER_MASK) {
1730 ret = __irq_set_trigger(desc,
1731 new->flags & IRQF_TRIGGER_MASK);
1732
1733 if (ret)
1734 goto out_unlock;
1735 }
1736
1737 /*
1738 * Activate the interrupt. That activation must happen
1739 * independently of IRQ_NOAUTOEN. request_irq() can fail
1740 * and the callers are supposed to handle
1741 * that. enable_irq() of an interrupt requested with
1742 * IRQ_NOAUTOEN is not supposed to fail. The activation
1743 * keeps it in shutdown mode, it merily associates
1744 * resources if necessary and if that's not possible it
1745 * fails. Interrupts which are in managed shutdown mode
1746 * will simply ignore that activation request.
1747 */
1748 ret = irq_activate(desc);
1749 if (ret)
1750 goto out_unlock;
1751
1752 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1753 IRQS_ONESHOT | IRQS_WAITING);
1754 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1755
1756 if (new->flags & IRQF_PERCPU) {
1757 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1758 irq_settings_set_per_cpu(desc);
1759 if (new->flags & IRQF_NO_DEBUG)
1760 irq_settings_set_no_debug(desc);
1761 }
1762
1763 if (noirqdebug)
1764 irq_settings_set_no_debug(desc);
1765
1766 if (new->flags & IRQF_ONESHOT)
1767 desc->istate |= IRQS_ONESHOT;
1768
1769 /* Exclude IRQ from balancing if requested */
1770 if (new->flags & IRQF_NOBALANCING) {
1771 irq_settings_set_no_balancing(desc);
1772 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1773 }
1774
1775 if (!(new->flags & IRQF_NO_AUTOEN) &&
1776 irq_settings_can_autoenable(desc)) {
1777 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1778 } else {
1779 /*
1780 * Shared interrupts do not go well with disabling
1781 * auto enable. The sharing interrupt might request
1782 * it while it's still disabled and then wait for
1783 * interrupts forever.
1784 */
1785 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1786 /* Undo nested disables: */
1787 desc->depth = 1;
1788 }
1789
1790 } else if (new->flags & IRQF_TRIGGER_MASK) {
1791 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1792 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1793
1794 if (nmsk != omsk)
1795 /* hope the handler works with current trigger mode */
1796 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1797 irq, omsk, nmsk);
1798 }
1799
1800 *old_ptr = new;
1801
1802 irq_pm_install_action(desc, new);
1803
1804 /* Reset broken irq detection when installing new handler */
1805 desc->irq_count = 0;
1806 desc->irqs_unhandled = 0;
1807
1808 /*
1809 * Check whether we disabled the irq via the spurious handler
1810 * before. Reenable it and give it another chance.
1811 */
1812 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1813 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1814 __enable_irq(desc);
1815 }
1816
1817 raw_spin_unlock_irqrestore(&desc->lock, flags);
1818 chip_bus_sync_unlock(desc);
1819 mutex_unlock(&desc->request_mutex);
1820
1821 irq_setup_timings(desc, new);
1822
1823 wake_up_and_wait_for_irq_thread_ready(desc, new);
1824 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1825
1826 register_irq_proc(irq, desc);
1827 new->dir = NULL;
1828 register_handler_proc(irq, new);
1829 return 0;
1830
1831mismatch:
1832 if (!(new->flags & IRQF_PROBE_SHARED)) {
1833 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1834 irq, new->flags, new->name, old->flags, old->name);
1835#ifdef CONFIG_DEBUG_SHIRQ
1836 dump_stack();
1837#endif
1838 }
1839 ret = -EBUSY;
1840
1841out_unlock:
1842 raw_spin_unlock_irqrestore(&desc->lock, flags);
1843
1844 if (!desc->action)
1845 irq_release_resources(desc);
1846out_bus_unlock:
1847 chip_bus_sync_unlock(desc);
1848 mutex_unlock(&desc->request_mutex);
1849
1850out_thread:
1851 if (new->thread) {
1852 struct task_struct *t = new->thread;
1853
1854 new->thread = NULL;
1855 kthread_stop_put(t);
1856 }
1857 if (new->secondary && new->secondary->thread) {
1858 struct task_struct *t = new->secondary->thread;
1859
1860 new->secondary->thread = NULL;
1861 kthread_stop_put(t);
1862 }
1863out_mput:
1864 module_put(desc->owner);
1865 return ret;
1866}
1867
1868/*
1869 * Internal function to unregister an irqaction - used to free
1870 * regular and special interrupts that are part of the architecture.
1871 */
1872static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1873{
1874 unsigned irq = desc->irq_data.irq;
1875 struct irqaction *action, **action_ptr;
1876 unsigned long flags;
1877
1878 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1879
1880 mutex_lock(&desc->request_mutex);
1881 chip_bus_lock(desc);
1882 raw_spin_lock_irqsave(&desc->lock, flags);
1883
1884 /*
1885 * There can be multiple actions per IRQ descriptor, find the right
1886 * one based on the dev_id:
1887 */
1888 action_ptr = &desc->action;
1889 for (;;) {
1890 action = *action_ptr;
1891
1892 if (!action) {
1893 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1894 raw_spin_unlock_irqrestore(&desc->lock, flags);
1895 chip_bus_sync_unlock(desc);
1896 mutex_unlock(&desc->request_mutex);
1897 return NULL;
1898 }
1899
1900 if (action->dev_id == dev_id)
1901 break;
1902 action_ptr = &action->next;
1903 }
1904
1905 /* Found it - now remove it from the list of entries: */
1906 *action_ptr = action->next;
1907
1908 irq_pm_remove_action(desc, action);
1909
1910 /* If this was the last handler, shut down the IRQ line: */
1911 if (!desc->action) {
1912 irq_settings_clr_disable_unlazy(desc);
1913 /* Only shutdown. Deactivate after synchronize_hardirq() */
1914 irq_shutdown(desc);
1915 }
1916
1917#ifdef CONFIG_SMP
1918 /* make sure affinity_hint is cleaned up */
1919 if (WARN_ON_ONCE(desc->affinity_hint))
1920 desc->affinity_hint = NULL;
1921#endif
1922
1923 raw_spin_unlock_irqrestore(&desc->lock, flags);
1924 /*
1925 * Drop bus_lock here so the changes which were done in the chip
1926 * callbacks above are synced out to the irq chips which hang
1927 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1928 *
1929 * Aside of that the bus_lock can also be taken from the threaded
1930 * handler in irq_finalize_oneshot() which results in a deadlock
1931 * because kthread_stop() would wait forever for the thread to
1932 * complete, which is blocked on the bus lock.
1933 *
1934 * The still held desc->request_mutex() protects against a
1935 * concurrent request_irq() of this irq so the release of resources
1936 * and timing data is properly serialized.
1937 */
1938 chip_bus_sync_unlock(desc);
1939
1940 unregister_handler_proc(irq, action);
1941
1942 /*
1943 * Make sure it's not being used on another CPU and if the chip
1944 * supports it also make sure that there is no (not yet serviced)
1945 * interrupt in flight at the hardware level.
1946 */
1947 __synchronize_irq(desc);
1948
1949#ifdef CONFIG_DEBUG_SHIRQ
1950 /*
1951 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1952 * event to happen even now it's being freed, so let's make sure that
1953 * is so by doing an extra call to the handler ....
1954 *
1955 * ( We do this after actually deregistering it, to make sure that a
1956 * 'real' IRQ doesn't run in parallel with our fake. )
1957 */
1958 if (action->flags & IRQF_SHARED) {
1959 local_irq_save(flags);
1960 action->handler(irq, dev_id);
1961 local_irq_restore(flags);
1962 }
1963#endif
1964
1965 /*
1966 * The action has already been removed above, but the thread writes
1967 * its oneshot mask bit when it completes. Though request_mutex is
1968 * held across this which prevents __setup_irq() from handing out
1969 * the same bit to a newly requested action.
1970 */
1971 if (action->thread) {
1972 kthread_stop_put(action->thread);
1973 if (action->secondary && action->secondary->thread)
1974 kthread_stop_put(action->secondary->thread);
1975 }
1976
1977 /* Last action releases resources */
1978 if (!desc->action) {
1979 /*
1980 * Reacquire bus lock as irq_release_resources() might
1981 * require it to deallocate resources over the slow bus.
1982 */
1983 chip_bus_lock(desc);
1984 /*
1985 * There is no interrupt on the fly anymore. Deactivate it
1986 * completely.
1987 */
1988 raw_spin_lock_irqsave(&desc->lock, flags);
1989 irq_domain_deactivate_irq(&desc->irq_data);
1990 raw_spin_unlock_irqrestore(&desc->lock, flags);
1991
1992 irq_release_resources(desc);
1993 chip_bus_sync_unlock(desc);
1994 irq_remove_timings(desc);
1995 }
1996
1997 mutex_unlock(&desc->request_mutex);
1998
1999 irq_chip_pm_put(&desc->irq_data);
2000 module_put(desc->owner);
2001 kfree(action->secondary);
2002 return action;
2003}
2004
2005/**
2006 * free_irq - free an interrupt allocated with request_irq
2007 * @irq: Interrupt line to free
2008 * @dev_id: Device identity to free
2009 *
2010 * Remove an interrupt handler. The handler is removed and if the
2011 * interrupt line is no longer in use by any driver it is disabled.
2012 * On a shared IRQ the caller must ensure the interrupt is disabled
2013 * on the card it drives before calling this function. The function
2014 * does not return until any executing interrupts for this IRQ
2015 * have completed.
2016 *
2017 * This function must not be called from interrupt context.
2018 *
2019 * Returns the devname argument passed to request_irq.
2020 */
2021const void *free_irq(unsigned int irq, void *dev_id)
2022{
2023 struct irq_desc *desc = irq_to_desc(irq);
2024 struct irqaction *action;
2025 const char *devname;
2026
2027 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2028 return NULL;
2029
2030#ifdef CONFIG_SMP
2031 if (WARN_ON(desc->affinity_notify))
2032 desc->affinity_notify = NULL;
2033#endif
2034
2035 action = __free_irq(desc, dev_id);
2036
2037 if (!action)
2038 return NULL;
2039
2040 devname = action->name;
2041 kfree(action);
2042 return devname;
2043}
2044EXPORT_SYMBOL(free_irq);
2045
2046/* This function must be called with desc->lock held */
2047static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2048{
2049 const char *devname = NULL;
2050
2051 desc->istate &= ~IRQS_NMI;
2052
2053 if (!WARN_ON(desc->action == NULL)) {
2054 irq_pm_remove_action(desc, desc->action);
2055 devname = desc->action->name;
2056 unregister_handler_proc(irq, desc->action);
2057
2058 kfree(desc->action);
2059 desc->action = NULL;
2060 }
2061
2062 irq_settings_clr_disable_unlazy(desc);
2063 irq_shutdown_and_deactivate(desc);
2064
2065 irq_release_resources(desc);
2066
2067 irq_chip_pm_put(&desc->irq_data);
2068 module_put(desc->owner);
2069
2070 return devname;
2071}
2072
2073const void *free_nmi(unsigned int irq, void *dev_id)
2074{
2075 struct irq_desc *desc = irq_to_desc(irq);
2076 unsigned long flags;
2077 const void *devname;
2078
2079 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2080 return NULL;
2081
2082 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2083 return NULL;
2084
2085 /* NMI still enabled */
2086 if (WARN_ON(desc->depth == 0))
2087 disable_nmi_nosync(irq);
2088
2089 raw_spin_lock_irqsave(&desc->lock, flags);
2090
2091 irq_nmi_teardown(desc);
2092 devname = __cleanup_nmi(irq, desc);
2093
2094 raw_spin_unlock_irqrestore(&desc->lock, flags);
2095
2096 return devname;
2097}
2098
2099/**
2100 * request_threaded_irq - allocate an interrupt line
2101 * @irq: Interrupt line to allocate
2102 * @handler: Function to be called when the IRQ occurs.
2103 * Primary handler for threaded interrupts.
2104 * If handler is NULL and thread_fn != NULL
2105 * the default primary handler is installed.
2106 * @thread_fn: Function called from the irq handler thread
2107 * If NULL, no irq thread is created
2108 * @irqflags: Interrupt type flags
2109 * @devname: An ascii name for the claiming device
2110 * @dev_id: A cookie passed back to the handler function
2111 *
2112 * This call allocates interrupt resources and enables the
2113 * interrupt line and IRQ handling. From the point this
2114 * call is made your handler function may be invoked. Since
2115 * your handler function must clear any interrupt the board
2116 * raises, you must take care both to initialise your hardware
2117 * and to set up the interrupt handler in the right order.
2118 *
2119 * If you want to set up a threaded irq handler for your device
2120 * then you need to supply @handler and @thread_fn. @handler is
2121 * still called in hard interrupt context and has to check
2122 * whether the interrupt originates from the device. If yes it
2123 * needs to disable the interrupt on the device and return
2124 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2125 * @thread_fn. This split handler design is necessary to support
2126 * shared interrupts.
2127 *
2128 * Dev_id must be globally unique. Normally the address of the
2129 * device data structure is used as the cookie. Since the handler
2130 * receives this value it makes sense to use it.
2131 *
2132 * If your interrupt is shared you must pass a non NULL dev_id
2133 * as this is required when freeing the interrupt.
2134 *
2135 * Flags:
2136 *
2137 * IRQF_SHARED Interrupt is shared
2138 * IRQF_TRIGGER_* Specify active edge(s) or level
2139 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2140 */
2141int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2142 irq_handler_t thread_fn, unsigned long irqflags,
2143 const char *devname, void *dev_id)
2144{
2145 struct irqaction *action;
2146 struct irq_desc *desc;
2147 int retval;
2148
2149 if (irq == IRQ_NOTCONNECTED)
2150 return -ENOTCONN;
2151
2152 /*
2153 * Sanity-check: shared interrupts must pass in a real dev-ID,
2154 * otherwise we'll have trouble later trying to figure out
2155 * which interrupt is which (messes up the interrupt freeing
2156 * logic etc).
2157 *
2158 * Also shared interrupts do not go well with disabling auto enable.
2159 * The sharing interrupt might request it while it's still disabled
2160 * and then wait for interrupts forever.
2161 *
2162 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2163 * it cannot be set along with IRQF_NO_SUSPEND.
2164 */
2165 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2166 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2167 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2168 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2169 return -EINVAL;
2170
2171 desc = irq_to_desc(irq);
2172 if (!desc)
2173 return -EINVAL;
2174
2175 if (!irq_settings_can_request(desc) ||
2176 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2177 return -EINVAL;
2178
2179 if (!handler) {
2180 if (!thread_fn)
2181 return -EINVAL;
2182 handler = irq_default_primary_handler;
2183 }
2184
2185 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2186 if (!action)
2187 return -ENOMEM;
2188
2189 action->handler = handler;
2190 action->thread_fn = thread_fn;
2191 action->flags = irqflags;
2192 action->name = devname;
2193 action->dev_id = dev_id;
2194
2195 retval = irq_chip_pm_get(&desc->irq_data);
2196 if (retval < 0) {
2197 kfree(action);
2198 return retval;
2199 }
2200
2201 retval = __setup_irq(irq, desc, action);
2202
2203 if (retval) {
2204 irq_chip_pm_put(&desc->irq_data);
2205 kfree(action->secondary);
2206 kfree(action);
2207 }
2208
2209#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2210 if (!retval && (irqflags & IRQF_SHARED)) {
2211 /*
2212 * It's a shared IRQ -- the driver ought to be prepared for it
2213 * to happen immediately, so let's make sure....
2214 * We disable the irq to make sure that a 'real' IRQ doesn't
2215 * run in parallel with our fake.
2216 */
2217 unsigned long flags;
2218
2219 disable_irq(irq);
2220 local_irq_save(flags);
2221
2222 handler(irq, dev_id);
2223
2224 local_irq_restore(flags);
2225 enable_irq(irq);
2226 }
2227#endif
2228 return retval;
2229}
2230EXPORT_SYMBOL(request_threaded_irq);
2231
2232/**
2233 * request_any_context_irq - allocate an interrupt line
2234 * @irq: Interrupt line to allocate
2235 * @handler: Function to be called when the IRQ occurs.
2236 * Threaded handler for threaded interrupts.
2237 * @flags: Interrupt type flags
2238 * @name: An ascii name for the claiming device
2239 * @dev_id: A cookie passed back to the handler function
2240 *
2241 * This call allocates interrupt resources and enables the
2242 * interrupt line and IRQ handling. It selects either a
2243 * hardirq or threaded handling method depending on the
2244 * context.
2245 *
2246 * On failure, it returns a negative value. On success,
2247 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2248 */
2249int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2250 unsigned long flags, const char *name, void *dev_id)
2251{
2252 struct irq_desc *desc;
2253 int ret;
2254
2255 if (irq == IRQ_NOTCONNECTED)
2256 return -ENOTCONN;
2257
2258 desc = irq_to_desc(irq);
2259 if (!desc)
2260 return -EINVAL;
2261
2262 if (irq_settings_is_nested_thread(desc)) {
2263 ret = request_threaded_irq(irq, NULL, handler,
2264 flags, name, dev_id);
2265 return !ret ? IRQC_IS_NESTED : ret;
2266 }
2267
2268 ret = request_irq(irq, handler, flags, name, dev_id);
2269 return !ret ? IRQC_IS_HARDIRQ : ret;
2270}
2271EXPORT_SYMBOL_GPL(request_any_context_irq);
2272
2273/**
2274 * request_nmi - allocate an interrupt line for NMI delivery
2275 * @irq: Interrupt line to allocate
2276 * @handler: Function to be called when the IRQ occurs.
2277 * Threaded handler for threaded interrupts.
2278 * @irqflags: Interrupt type flags
2279 * @name: An ascii name for the claiming device
2280 * @dev_id: A cookie passed back to the handler function
2281 *
2282 * This call allocates interrupt resources and enables the
2283 * interrupt line and IRQ handling. It sets up the IRQ line
2284 * to be handled as an NMI.
2285 *
2286 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2287 * cannot be threaded.
2288 *
2289 * Interrupt lines requested for NMI delivering must produce per cpu
2290 * interrupts and have auto enabling setting disabled.
2291 *
2292 * Dev_id must be globally unique. Normally the address of the
2293 * device data structure is used as the cookie. Since the handler
2294 * receives this value it makes sense to use it.
2295 *
2296 * If the interrupt line cannot be used to deliver NMIs, function
2297 * will fail and return a negative value.
2298 */
2299int request_nmi(unsigned int irq, irq_handler_t handler,
2300 unsigned long irqflags, const char *name, void *dev_id)
2301{
2302 struct irqaction *action;
2303 struct irq_desc *desc;
2304 unsigned long flags;
2305 int retval;
2306
2307 if (irq == IRQ_NOTCONNECTED)
2308 return -ENOTCONN;
2309
2310 /* NMI cannot be shared, used for Polling */
2311 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2312 return -EINVAL;
2313
2314 if (!(irqflags & IRQF_PERCPU))
2315 return -EINVAL;
2316
2317 if (!handler)
2318 return -EINVAL;
2319
2320 desc = irq_to_desc(irq);
2321
2322 if (!desc || (irq_settings_can_autoenable(desc) &&
2323 !(irqflags & IRQF_NO_AUTOEN)) ||
2324 !irq_settings_can_request(desc) ||
2325 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2326 !irq_supports_nmi(desc))
2327 return -EINVAL;
2328
2329 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2330 if (!action)
2331 return -ENOMEM;
2332
2333 action->handler = handler;
2334 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2335 action->name = name;
2336 action->dev_id = dev_id;
2337
2338 retval = irq_chip_pm_get(&desc->irq_data);
2339 if (retval < 0)
2340 goto err_out;
2341
2342 retval = __setup_irq(irq, desc, action);
2343 if (retval)
2344 goto err_irq_setup;
2345
2346 raw_spin_lock_irqsave(&desc->lock, flags);
2347
2348 /* Setup NMI state */
2349 desc->istate |= IRQS_NMI;
2350 retval = irq_nmi_setup(desc);
2351 if (retval) {
2352 __cleanup_nmi(irq, desc);
2353 raw_spin_unlock_irqrestore(&desc->lock, flags);
2354 return -EINVAL;
2355 }
2356
2357 raw_spin_unlock_irqrestore(&desc->lock, flags);
2358
2359 return 0;
2360
2361err_irq_setup:
2362 irq_chip_pm_put(&desc->irq_data);
2363err_out:
2364 kfree(action);
2365
2366 return retval;
2367}
2368
2369void enable_percpu_irq(unsigned int irq, unsigned int type)
2370{
2371 unsigned int cpu = smp_processor_id();
2372 unsigned long flags;
2373 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2374
2375 if (!desc)
2376 return;
2377
2378 /*
2379 * If the trigger type is not specified by the caller, then
2380 * use the default for this interrupt.
2381 */
2382 type &= IRQ_TYPE_SENSE_MASK;
2383 if (type == IRQ_TYPE_NONE)
2384 type = irqd_get_trigger_type(&desc->irq_data);
2385
2386 if (type != IRQ_TYPE_NONE) {
2387 int ret;
2388
2389 ret = __irq_set_trigger(desc, type);
2390
2391 if (ret) {
2392 WARN(1, "failed to set type for IRQ%d\n", irq);
2393 goto out;
2394 }
2395 }
2396
2397 irq_percpu_enable(desc, cpu);
2398out:
2399 irq_put_desc_unlock(desc, flags);
2400}
2401EXPORT_SYMBOL_GPL(enable_percpu_irq);
2402
2403void enable_percpu_nmi(unsigned int irq, unsigned int type)
2404{
2405 enable_percpu_irq(irq, type);
2406}
2407
2408/**
2409 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2410 * @irq: Linux irq number to check for
2411 *
2412 * Must be called from a non migratable context. Returns the enable
2413 * state of a per cpu interrupt on the current cpu.
2414 */
2415bool irq_percpu_is_enabled(unsigned int irq)
2416{
2417 unsigned int cpu = smp_processor_id();
2418 struct irq_desc *desc;
2419 unsigned long flags;
2420 bool is_enabled;
2421
2422 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2423 if (!desc)
2424 return false;
2425
2426 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2427 irq_put_desc_unlock(desc, flags);
2428
2429 return is_enabled;
2430}
2431EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2432
2433void disable_percpu_irq(unsigned int irq)
2434{
2435 unsigned int cpu = smp_processor_id();
2436 unsigned long flags;
2437 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2438
2439 if (!desc)
2440 return;
2441
2442 irq_percpu_disable(desc, cpu);
2443 irq_put_desc_unlock(desc, flags);
2444}
2445EXPORT_SYMBOL_GPL(disable_percpu_irq);
2446
2447void disable_percpu_nmi(unsigned int irq)
2448{
2449 disable_percpu_irq(irq);
2450}
2451
2452/*
2453 * Internal function to unregister a percpu irqaction.
2454 */
2455static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2456{
2457 struct irq_desc *desc = irq_to_desc(irq);
2458 struct irqaction *action;
2459 unsigned long flags;
2460
2461 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2462
2463 if (!desc)
2464 return NULL;
2465
2466 raw_spin_lock_irqsave(&desc->lock, flags);
2467
2468 action = desc->action;
2469 if (!action || action->percpu_dev_id != dev_id) {
2470 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2471 goto bad;
2472 }
2473
2474 if (!cpumask_empty(desc->percpu_enabled)) {
2475 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2476 irq, cpumask_first(desc->percpu_enabled));
2477 goto bad;
2478 }
2479
2480 /* Found it - now remove it from the list of entries: */
2481 desc->action = NULL;
2482
2483 desc->istate &= ~IRQS_NMI;
2484
2485 raw_spin_unlock_irqrestore(&desc->lock, flags);
2486
2487 unregister_handler_proc(irq, action);
2488
2489 irq_chip_pm_put(&desc->irq_data);
2490 module_put(desc->owner);
2491 return action;
2492
2493bad:
2494 raw_spin_unlock_irqrestore(&desc->lock, flags);
2495 return NULL;
2496}
2497
2498/**
2499 * remove_percpu_irq - free a per-cpu interrupt
2500 * @irq: Interrupt line to free
2501 * @act: irqaction for the interrupt
2502 *
2503 * Used to remove interrupts statically setup by the early boot process.
2504 */
2505void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2506{
2507 struct irq_desc *desc = irq_to_desc(irq);
2508
2509 if (desc && irq_settings_is_per_cpu_devid(desc))
2510 __free_percpu_irq(irq, act->percpu_dev_id);
2511}
2512
2513/**
2514 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2515 * @irq: Interrupt line to free
2516 * @dev_id: Device identity to free
2517 *
2518 * Remove a percpu interrupt handler. The handler is removed, but
2519 * the interrupt line is not disabled. This must be done on each
2520 * CPU before calling this function. The function does not return
2521 * until any executing interrupts for this IRQ have completed.
2522 *
2523 * This function must not be called from interrupt context.
2524 */
2525void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2526{
2527 struct irq_desc *desc = irq_to_desc(irq);
2528
2529 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2530 return;
2531
2532 chip_bus_lock(desc);
2533 kfree(__free_percpu_irq(irq, dev_id));
2534 chip_bus_sync_unlock(desc);
2535}
2536EXPORT_SYMBOL_GPL(free_percpu_irq);
2537
2538void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2539{
2540 struct irq_desc *desc = irq_to_desc(irq);
2541
2542 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2543 return;
2544
2545 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2546 return;
2547
2548 kfree(__free_percpu_irq(irq, dev_id));
2549}
2550
2551/**
2552 * setup_percpu_irq - setup a per-cpu interrupt
2553 * @irq: Interrupt line to setup
2554 * @act: irqaction for the interrupt
2555 *
2556 * Used to statically setup per-cpu interrupts in the early boot process.
2557 */
2558int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2559{
2560 struct irq_desc *desc = irq_to_desc(irq);
2561 int retval;
2562
2563 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2564 return -EINVAL;
2565
2566 retval = irq_chip_pm_get(&desc->irq_data);
2567 if (retval < 0)
2568 return retval;
2569
2570 retval = __setup_irq(irq, desc, act);
2571
2572 if (retval)
2573 irq_chip_pm_put(&desc->irq_data);
2574
2575 return retval;
2576}
2577
2578/**
2579 * __request_percpu_irq - allocate a percpu interrupt line
2580 * @irq: Interrupt line to allocate
2581 * @handler: Function to be called when the IRQ occurs.
2582 * @flags: Interrupt type flags (IRQF_TIMER only)
2583 * @devname: An ascii name for the claiming device
2584 * @dev_id: A percpu cookie passed back to the handler function
2585 *
2586 * This call allocates interrupt resources and enables the
2587 * interrupt on the local CPU. If the interrupt is supposed to be
2588 * enabled on other CPUs, it has to be done on each CPU using
2589 * enable_percpu_irq().
2590 *
2591 * Dev_id must be globally unique. It is a per-cpu variable, and
2592 * the handler gets called with the interrupted CPU's instance of
2593 * that variable.
2594 */
2595int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2596 unsigned long flags, const char *devname,
2597 void __percpu *dev_id)
2598{
2599 struct irqaction *action;
2600 struct irq_desc *desc;
2601 int retval;
2602
2603 if (!dev_id)
2604 return -EINVAL;
2605
2606 desc = irq_to_desc(irq);
2607 if (!desc || !irq_settings_can_request(desc) ||
2608 !irq_settings_is_per_cpu_devid(desc))
2609 return -EINVAL;
2610
2611 if (flags && flags != IRQF_TIMER)
2612 return -EINVAL;
2613
2614 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2615 if (!action)
2616 return -ENOMEM;
2617
2618 action->handler = handler;
2619 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2620 action->name = devname;
2621 action->percpu_dev_id = dev_id;
2622
2623 retval = irq_chip_pm_get(&desc->irq_data);
2624 if (retval < 0) {
2625 kfree(action);
2626 return retval;
2627 }
2628
2629 retval = __setup_irq(irq, desc, action);
2630
2631 if (retval) {
2632 irq_chip_pm_put(&desc->irq_data);
2633 kfree(action);
2634 }
2635
2636 return retval;
2637}
2638EXPORT_SYMBOL_GPL(__request_percpu_irq);
2639
2640/**
2641 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2642 * @irq: Interrupt line to allocate
2643 * @handler: Function to be called when the IRQ occurs.
2644 * @name: An ascii name for the claiming device
2645 * @dev_id: A percpu cookie passed back to the handler function
2646 *
2647 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2648 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2649 * being enabled on the same CPU by using enable_percpu_nmi().
2650 *
2651 * Dev_id must be globally unique. It is a per-cpu variable, and
2652 * the handler gets called with the interrupted CPU's instance of
2653 * that variable.
2654 *
2655 * Interrupt lines requested for NMI delivering should have auto enabling
2656 * setting disabled.
2657 *
2658 * If the interrupt line cannot be used to deliver NMIs, function
2659 * will fail returning a negative value.
2660 */
2661int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2662 const char *name, void __percpu *dev_id)
2663{
2664 struct irqaction *action;
2665 struct irq_desc *desc;
2666 unsigned long flags;
2667 int retval;
2668
2669 if (!handler)
2670 return -EINVAL;
2671
2672 desc = irq_to_desc(irq);
2673
2674 if (!desc || !irq_settings_can_request(desc) ||
2675 !irq_settings_is_per_cpu_devid(desc) ||
2676 irq_settings_can_autoenable(desc) ||
2677 !irq_supports_nmi(desc))
2678 return -EINVAL;
2679
2680 /* The line cannot already be NMI */
2681 if (desc->istate & IRQS_NMI)
2682 return -EINVAL;
2683
2684 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2685 if (!action)
2686 return -ENOMEM;
2687
2688 action->handler = handler;
2689 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2690 | IRQF_NOBALANCING;
2691 action->name = name;
2692 action->percpu_dev_id = dev_id;
2693
2694 retval = irq_chip_pm_get(&desc->irq_data);
2695 if (retval < 0)
2696 goto err_out;
2697
2698 retval = __setup_irq(irq, desc, action);
2699 if (retval)
2700 goto err_irq_setup;
2701
2702 raw_spin_lock_irqsave(&desc->lock, flags);
2703 desc->istate |= IRQS_NMI;
2704 raw_spin_unlock_irqrestore(&desc->lock, flags);
2705
2706 return 0;
2707
2708err_irq_setup:
2709 irq_chip_pm_put(&desc->irq_data);
2710err_out:
2711 kfree(action);
2712
2713 return retval;
2714}
2715
2716/**
2717 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2718 * @irq: Interrupt line to prepare for NMI delivery
2719 *
2720 * This call prepares an interrupt line to deliver NMI on the current CPU,
2721 * before that interrupt line gets enabled with enable_percpu_nmi().
2722 *
2723 * As a CPU local operation, this should be called from non-preemptible
2724 * context.
2725 *
2726 * If the interrupt line cannot be used to deliver NMIs, function
2727 * will fail returning a negative value.
2728 */
2729int prepare_percpu_nmi(unsigned int irq)
2730{
2731 unsigned long flags;
2732 struct irq_desc *desc;
2733 int ret = 0;
2734
2735 WARN_ON(preemptible());
2736
2737 desc = irq_get_desc_lock(irq, &flags,
2738 IRQ_GET_DESC_CHECK_PERCPU);
2739 if (!desc)
2740 return -EINVAL;
2741
2742 if (WARN(!(desc->istate & IRQS_NMI),
2743 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2744 irq)) {
2745 ret = -EINVAL;
2746 goto out;
2747 }
2748
2749 ret = irq_nmi_setup(desc);
2750 if (ret) {
2751 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2752 goto out;
2753 }
2754
2755out:
2756 irq_put_desc_unlock(desc, flags);
2757 return ret;
2758}
2759
2760/**
2761 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2762 * @irq: Interrupt line from which CPU local NMI configuration should be
2763 * removed
2764 *
2765 * This call undoes the setup done by prepare_percpu_nmi().
2766 *
2767 * IRQ line should not be enabled for the current CPU.
2768 *
2769 * As a CPU local operation, this should be called from non-preemptible
2770 * context.
2771 */
2772void teardown_percpu_nmi(unsigned int irq)
2773{
2774 unsigned long flags;
2775 struct irq_desc *desc;
2776
2777 WARN_ON(preemptible());
2778
2779 desc = irq_get_desc_lock(irq, &flags,
2780 IRQ_GET_DESC_CHECK_PERCPU);
2781 if (!desc)
2782 return;
2783
2784 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2785 goto out;
2786
2787 irq_nmi_teardown(desc);
2788out:
2789 irq_put_desc_unlock(desc, flags);
2790}
2791
2792int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2793 bool *state)
2794{
2795 struct irq_chip *chip;
2796 int err = -EINVAL;
2797
2798 do {
2799 chip = irq_data_get_irq_chip(data);
2800 if (WARN_ON_ONCE(!chip))
2801 return -ENODEV;
2802 if (chip->irq_get_irqchip_state)
2803 break;
2804#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2805 data = data->parent_data;
2806#else
2807 data = NULL;
2808#endif
2809 } while (data);
2810
2811 if (data)
2812 err = chip->irq_get_irqchip_state(data, which, state);
2813 return err;
2814}
2815
2816/**
2817 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2818 * @irq: Interrupt line that is forwarded to a VM
2819 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2820 * @state: a pointer to a boolean where the state is to be stored
2821 *
2822 * This call snapshots the internal irqchip state of an
2823 * interrupt, returning into @state the bit corresponding to
2824 * stage @which
2825 *
2826 * This function should be called with preemption disabled if the
2827 * interrupt controller has per-cpu registers.
2828 */
2829int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2830 bool *state)
2831{
2832 struct irq_desc *desc;
2833 struct irq_data *data;
2834 unsigned long flags;
2835 int err = -EINVAL;
2836
2837 desc = irq_get_desc_buslock(irq, &flags, 0);
2838 if (!desc)
2839 return err;
2840
2841 data = irq_desc_get_irq_data(desc);
2842
2843 err = __irq_get_irqchip_state(data, which, state);
2844
2845 irq_put_desc_busunlock(desc, flags);
2846 return err;
2847}
2848EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2849
2850/**
2851 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2852 * @irq: Interrupt line that is forwarded to a VM
2853 * @which: State to be restored (one of IRQCHIP_STATE_*)
2854 * @val: Value corresponding to @which
2855 *
2856 * This call sets the internal irqchip state of an interrupt,
2857 * depending on the value of @which.
2858 *
2859 * This function should be called with migration disabled if the
2860 * interrupt controller has per-cpu registers.
2861 */
2862int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2863 bool val)
2864{
2865 struct irq_desc *desc;
2866 struct irq_data *data;
2867 struct irq_chip *chip;
2868 unsigned long flags;
2869 int err = -EINVAL;
2870
2871 desc = irq_get_desc_buslock(irq, &flags, 0);
2872 if (!desc)
2873 return err;
2874
2875 data = irq_desc_get_irq_data(desc);
2876
2877 do {
2878 chip = irq_data_get_irq_chip(data);
2879 if (WARN_ON_ONCE(!chip)) {
2880 err = -ENODEV;
2881 goto out_unlock;
2882 }
2883 if (chip->irq_set_irqchip_state)
2884 break;
2885#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2886 data = data->parent_data;
2887#else
2888 data = NULL;
2889#endif
2890 } while (data);
2891
2892 if (data)
2893 err = chip->irq_set_irqchip_state(data, which, val);
2894
2895out_unlock:
2896 irq_put_desc_busunlock(desc, flags);
2897 return err;
2898}
2899EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2900
2901/**
2902 * irq_has_action - Check whether an interrupt is requested
2903 * @irq: The linux irq number
2904 *
2905 * Returns: A snapshot of the current state
2906 */
2907bool irq_has_action(unsigned int irq)
2908{
2909 bool res;
2910
2911 rcu_read_lock();
2912 res = irq_desc_has_action(irq_to_desc(irq));
2913 rcu_read_unlock();
2914 return res;
2915}
2916EXPORT_SYMBOL_GPL(irq_has_action);
2917
2918/**
2919 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2920 * @irq: The linux irq number
2921 * @bitmask: The bitmask to evaluate
2922 *
2923 * Returns: True if one of the bits in @bitmask is set
2924 */
2925bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2926{
2927 struct irq_desc *desc;
2928 bool res = false;
2929
2930 rcu_read_lock();
2931 desc = irq_to_desc(irq);
2932 if (desc)
2933 res = !!(desc->status_use_accessors & bitmask);
2934 rcu_read_unlock();
2935 return res;
2936}
2937EXPORT_SYMBOL_GPL(irq_check_status_bit);