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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
28DEFINE_STATIC_KEY_FALSE(force_irqthreads_key);
29
30static int __init setup_forced_irqthreads(char *arg)
31{
32 static_branch_enable(&force_irqthreads_key);
33 return 0;
34}
35early_param("threadirqs", setup_forced_irqthreads);
36#endif
37
38static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
39{
40 struct irq_data *irqd = irq_desc_get_irq_data(desc);
41 bool inprogress;
42
43 do {
44 unsigned long flags;
45
46 /*
47 * Wait until we're out of the critical section. This might
48 * give the wrong answer due to the lack of memory barriers.
49 */
50 while (irqd_irq_inprogress(&desc->irq_data))
51 cpu_relax();
52
53 /* Ok, that indicated we're done: double-check carefully. */
54 raw_spin_lock_irqsave(&desc->lock, flags);
55 inprogress = irqd_irq_inprogress(&desc->irq_data);
56
57 /*
58 * If requested and supported, check at the chip whether it
59 * is in flight at the hardware level, i.e. already pending
60 * in a CPU and waiting for service and acknowledge.
61 */
62 if (!inprogress && sync_chip) {
63 /*
64 * Ignore the return code. inprogress is only updated
65 * when the chip supports it.
66 */
67 __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
68 &inprogress);
69 }
70 raw_spin_unlock_irqrestore(&desc->lock, flags);
71
72 /* Oops, that failed? */
73 } while (inprogress);
74}
75
76/**
77 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
78 * @irq: interrupt number to wait for
79 *
80 * This function waits for any pending hard IRQ handlers for this
81 * interrupt to complete before returning. If you use this
82 * function while holding a resource the IRQ handler may need you
83 * will deadlock. It does not take associated threaded handlers
84 * into account.
85 *
86 * Do not use this for shutdown scenarios where you must be sure
87 * that all parts (hardirq and threaded handler) have completed.
88 *
89 * Returns: false if a threaded handler is active.
90 *
91 * This function may be called - with care - from IRQ context.
92 *
93 * It does not check whether there is an interrupt in flight at the
94 * hardware level, but not serviced yet, as this might deadlock when
95 * called with interrupts disabled and the target CPU of the interrupt
96 * is the current CPU.
97 */
98bool synchronize_hardirq(unsigned int irq)
99{
100 struct irq_desc *desc = irq_to_desc(irq);
101
102 if (desc) {
103 __synchronize_hardirq(desc, false);
104 return !atomic_read(&desc->threads_active);
105 }
106
107 return true;
108}
109EXPORT_SYMBOL(synchronize_hardirq);
110
111/**
112 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
113 * @irq: interrupt number to wait for
114 *
115 * This function waits for any pending IRQ handlers for this interrupt
116 * to complete before returning. If you use this function while
117 * holding a resource the IRQ handler may need you will deadlock.
118 *
119 * Can only be called from preemptible code as it might sleep when
120 * an interrupt thread is associated to @irq.
121 *
122 * It optionally makes sure (when the irq chip supports that method)
123 * that the interrupt is not pending in any CPU and waiting for
124 * service.
125 */
126void synchronize_irq(unsigned int irq)
127{
128 struct irq_desc *desc = irq_to_desc(irq);
129
130 if (desc) {
131 __synchronize_hardirq(desc, true);
132 /*
133 * We made sure that no hardirq handler is
134 * running. Now verify that no threaded handlers are
135 * active.
136 */
137 wait_event(desc->wait_for_threads,
138 !atomic_read(&desc->threads_active));
139 }
140}
141EXPORT_SYMBOL(synchronize_irq);
142
143#ifdef CONFIG_SMP
144cpumask_var_t irq_default_affinity;
145
146static bool __irq_can_set_affinity(struct irq_desc *desc)
147{
148 if (!desc || !irqd_can_balance(&desc->irq_data) ||
149 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
150 return false;
151 return true;
152}
153
154/**
155 * irq_can_set_affinity - Check if the affinity of a given irq can be set
156 * @irq: Interrupt to check
157 *
158 */
159int irq_can_set_affinity(unsigned int irq)
160{
161 return __irq_can_set_affinity(irq_to_desc(irq));
162}
163
164/**
165 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
166 * @irq: Interrupt to check
167 *
168 * Like irq_can_set_affinity() above, but additionally checks for the
169 * AFFINITY_MANAGED flag.
170 */
171bool irq_can_set_affinity_usr(unsigned int irq)
172{
173 struct irq_desc *desc = irq_to_desc(irq);
174
175 return __irq_can_set_affinity(desc) &&
176 !irqd_affinity_is_managed(&desc->irq_data);
177}
178
179/**
180 * irq_set_thread_affinity - Notify irq threads to adjust affinity
181 * @desc: irq descriptor which has affinity changed
182 *
183 * We just set IRQTF_AFFINITY and delegate the affinity setting
184 * to the interrupt thread itself. We can not call
185 * set_cpus_allowed_ptr() here as we hold desc->lock and this
186 * code can be called from hard interrupt context.
187 */
188void irq_set_thread_affinity(struct irq_desc *desc)
189{
190 struct irqaction *action;
191
192 for_each_action_of_desc(desc, action)
193 if (action->thread)
194 set_bit(IRQTF_AFFINITY, &action->thread_flags);
195}
196
197#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
198static void irq_validate_effective_affinity(struct irq_data *data)
199{
200 const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
201 struct irq_chip *chip = irq_data_get_irq_chip(data);
202
203 if (!cpumask_empty(m))
204 return;
205 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
206 chip->name, data->irq);
207}
208#else
209static inline void irq_validate_effective_affinity(struct irq_data *data) { }
210#endif
211
212int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
213 bool force)
214{
215 struct irq_desc *desc = irq_data_to_desc(data);
216 struct irq_chip *chip = irq_data_get_irq_chip(data);
217 const struct cpumask *prog_mask;
218 int ret;
219
220 static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
221 static struct cpumask tmp_mask;
222
223 if (!chip || !chip->irq_set_affinity)
224 return -EINVAL;
225
226 raw_spin_lock(&tmp_mask_lock);
227 /*
228 * If this is a managed interrupt and housekeeping is enabled on
229 * it check whether the requested affinity mask intersects with
230 * a housekeeping CPU. If so, then remove the isolated CPUs from
231 * the mask and just keep the housekeeping CPU(s). This prevents
232 * the affinity setter from routing the interrupt to an isolated
233 * CPU to avoid that I/O submitted from a housekeeping CPU causes
234 * interrupts on an isolated one.
235 *
236 * If the masks do not intersect or include online CPU(s) then
237 * keep the requested mask. The isolated target CPUs are only
238 * receiving interrupts when the I/O operation was submitted
239 * directly from them.
240 *
241 * If all housekeeping CPUs in the affinity mask are offline, the
242 * interrupt will be migrated by the CPU hotplug code once a
243 * housekeeping CPU which belongs to the affinity mask comes
244 * online.
245 */
246 if (irqd_affinity_is_managed(data) &&
247 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
248 const struct cpumask *hk_mask;
249
250 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
251
252 cpumask_and(&tmp_mask, mask, hk_mask);
253 if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
254 prog_mask = mask;
255 else
256 prog_mask = &tmp_mask;
257 } else {
258 prog_mask = mask;
259 }
260
261 /*
262 * Make sure we only provide online CPUs to the irqchip,
263 * unless we are being asked to force the affinity (in which
264 * case we do as we are told).
265 */
266 cpumask_and(&tmp_mask, prog_mask, cpu_online_mask);
267 if (!force && !cpumask_empty(&tmp_mask))
268 ret = chip->irq_set_affinity(data, &tmp_mask, force);
269 else if (force)
270 ret = chip->irq_set_affinity(data, mask, force);
271 else
272 ret = -EINVAL;
273
274 raw_spin_unlock(&tmp_mask_lock);
275
276 switch (ret) {
277 case IRQ_SET_MASK_OK:
278 case IRQ_SET_MASK_OK_DONE:
279 cpumask_copy(desc->irq_common_data.affinity, mask);
280 fallthrough;
281 case IRQ_SET_MASK_OK_NOCOPY:
282 irq_validate_effective_affinity(data);
283 irq_set_thread_affinity(desc);
284 ret = 0;
285 }
286
287 return ret;
288}
289
290#ifdef CONFIG_GENERIC_PENDING_IRQ
291static inline int irq_set_affinity_pending(struct irq_data *data,
292 const struct cpumask *dest)
293{
294 struct irq_desc *desc = irq_data_to_desc(data);
295
296 irqd_set_move_pending(data);
297 irq_copy_pending(desc, dest);
298 return 0;
299}
300#else
301static inline int irq_set_affinity_pending(struct irq_data *data,
302 const struct cpumask *dest)
303{
304 return -EBUSY;
305}
306#endif
307
308static int irq_try_set_affinity(struct irq_data *data,
309 const struct cpumask *dest, bool force)
310{
311 int ret = irq_do_set_affinity(data, dest, force);
312
313 /*
314 * In case that the underlying vector management is busy and the
315 * architecture supports the generic pending mechanism then utilize
316 * this to avoid returning an error to user space.
317 */
318 if (ret == -EBUSY && !force)
319 ret = irq_set_affinity_pending(data, dest);
320 return ret;
321}
322
323static bool irq_set_affinity_deactivated(struct irq_data *data,
324 const struct cpumask *mask)
325{
326 struct irq_desc *desc = irq_data_to_desc(data);
327
328 /*
329 * Handle irq chips which can handle affinity only in activated
330 * state correctly
331 *
332 * If the interrupt is not yet activated, just store the affinity
333 * mask and do not call the chip driver at all. On activation the
334 * driver has to make sure anyway that the interrupt is in a
335 * usable state so startup works.
336 */
337 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
338 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
339 return false;
340
341 cpumask_copy(desc->irq_common_data.affinity, mask);
342 irq_data_update_effective_affinity(data, mask);
343 irqd_set(data, IRQD_AFFINITY_SET);
344 return true;
345}
346
347int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
348 bool force)
349{
350 struct irq_chip *chip = irq_data_get_irq_chip(data);
351 struct irq_desc *desc = irq_data_to_desc(data);
352 int ret = 0;
353
354 if (!chip || !chip->irq_set_affinity)
355 return -EINVAL;
356
357 if (irq_set_affinity_deactivated(data, mask))
358 return 0;
359
360 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
361 ret = irq_try_set_affinity(data, mask, force);
362 } else {
363 irqd_set_move_pending(data);
364 irq_copy_pending(desc, mask);
365 }
366
367 if (desc->affinity_notify) {
368 kref_get(&desc->affinity_notify->kref);
369 if (!schedule_work(&desc->affinity_notify->work)) {
370 /* Work was already scheduled, drop our extra ref */
371 kref_put(&desc->affinity_notify->kref,
372 desc->affinity_notify->release);
373 }
374 }
375 irqd_set(data, IRQD_AFFINITY_SET);
376
377 return ret;
378}
379
380/**
381 * irq_update_affinity_desc - Update affinity management for an interrupt
382 * @irq: The interrupt number to update
383 * @affinity: Pointer to the affinity descriptor
384 *
385 * This interface can be used to configure the affinity management of
386 * interrupts which have been allocated already.
387 *
388 * There are certain limitations on when it may be used - attempts to use it
389 * for when the kernel is configured for generic IRQ reservation mode (in
390 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
391 * managed/non-managed interrupt accounting. In addition, attempts to use it on
392 * an interrupt which is already started or which has already been configured
393 * as managed will also fail, as these mean invalid init state or double init.
394 */
395int irq_update_affinity_desc(unsigned int irq,
396 struct irq_affinity_desc *affinity)
397{
398 struct irq_desc *desc;
399 unsigned long flags;
400 bool activated;
401 int ret = 0;
402
403 /*
404 * Supporting this with the reservation scheme used by x86 needs
405 * some more thought. Fail it for now.
406 */
407 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
408 return -EOPNOTSUPP;
409
410 desc = irq_get_desc_buslock(irq, &flags, 0);
411 if (!desc)
412 return -EINVAL;
413
414 /* Requires the interrupt to be shut down */
415 if (irqd_is_started(&desc->irq_data)) {
416 ret = -EBUSY;
417 goto out_unlock;
418 }
419
420 /* Interrupts which are already managed cannot be modified */
421 if (irqd_affinity_is_managed(&desc->irq_data)) {
422 ret = -EBUSY;
423 goto out_unlock;
424 }
425
426 /*
427 * Deactivate the interrupt. That's required to undo
428 * anything an earlier activation has established.
429 */
430 activated = irqd_is_activated(&desc->irq_data);
431 if (activated)
432 irq_domain_deactivate_irq(&desc->irq_data);
433
434 if (affinity->is_managed) {
435 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
436 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
437 }
438
439 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
440
441 /* Restore the activation state */
442 if (activated)
443 irq_domain_activate_irq(&desc->irq_data, false);
444
445out_unlock:
446 irq_put_desc_busunlock(desc, flags);
447 return ret;
448}
449
450static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
451 bool force)
452{
453 struct irq_desc *desc = irq_to_desc(irq);
454 unsigned long flags;
455 int ret;
456
457 if (!desc)
458 return -EINVAL;
459
460 raw_spin_lock_irqsave(&desc->lock, flags);
461 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
462 raw_spin_unlock_irqrestore(&desc->lock, flags);
463 return ret;
464}
465
466/**
467 * irq_set_affinity - Set the irq affinity of a given irq
468 * @irq: Interrupt to set affinity
469 * @cpumask: cpumask
470 *
471 * Fails if cpumask does not contain an online CPU
472 */
473int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
474{
475 return __irq_set_affinity(irq, cpumask, false);
476}
477EXPORT_SYMBOL_GPL(irq_set_affinity);
478
479/**
480 * irq_force_affinity - Force the irq affinity of a given irq
481 * @irq: Interrupt to set affinity
482 * @cpumask: cpumask
483 *
484 * Same as irq_set_affinity, but without checking the mask against
485 * online cpus.
486 *
487 * Solely for low level cpu hotplug code, where we need to make per
488 * cpu interrupts affine before the cpu becomes online.
489 */
490int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
491{
492 return __irq_set_affinity(irq, cpumask, true);
493}
494EXPORT_SYMBOL_GPL(irq_force_affinity);
495
496int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
497 bool setaffinity)
498{
499 unsigned long flags;
500 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
501
502 if (!desc)
503 return -EINVAL;
504 desc->affinity_hint = m;
505 irq_put_desc_unlock(desc, flags);
506 if (m && setaffinity)
507 __irq_set_affinity(irq, m, false);
508 return 0;
509}
510EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
511
512static void irq_affinity_notify(struct work_struct *work)
513{
514 struct irq_affinity_notify *notify =
515 container_of(work, struct irq_affinity_notify, work);
516 struct irq_desc *desc = irq_to_desc(notify->irq);
517 cpumask_var_t cpumask;
518 unsigned long flags;
519
520 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
521 goto out;
522
523 raw_spin_lock_irqsave(&desc->lock, flags);
524 if (irq_move_pending(&desc->irq_data))
525 irq_get_pending(cpumask, desc);
526 else
527 cpumask_copy(cpumask, desc->irq_common_data.affinity);
528 raw_spin_unlock_irqrestore(&desc->lock, flags);
529
530 notify->notify(notify, cpumask);
531
532 free_cpumask_var(cpumask);
533out:
534 kref_put(¬ify->kref, notify->release);
535}
536
537/**
538 * irq_set_affinity_notifier - control notification of IRQ affinity changes
539 * @irq: Interrupt for which to enable/disable notification
540 * @notify: Context for notification, or %NULL to disable
541 * notification. Function pointers must be initialised;
542 * the other fields will be initialised by this function.
543 *
544 * Must be called in process context. Notification may only be enabled
545 * after the IRQ is allocated and must be disabled before the IRQ is
546 * freed using free_irq().
547 */
548int
549irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
550{
551 struct irq_desc *desc = irq_to_desc(irq);
552 struct irq_affinity_notify *old_notify;
553 unsigned long flags;
554
555 /* The release function is promised process context */
556 might_sleep();
557
558 if (!desc || desc->istate & IRQS_NMI)
559 return -EINVAL;
560
561 /* Complete initialisation of *notify */
562 if (notify) {
563 notify->irq = irq;
564 kref_init(¬ify->kref);
565 INIT_WORK(¬ify->work, irq_affinity_notify);
566 }
567
568 raw_spin_lock_irqsave(&desc->lock, flags);
569 old_notify = desc->affinity_notify;
570 desc->affinity_notify = notify;
571 raw_spin_unlock_irqrestore(&desc->lock, flags);
572
573 if (old_notify) {
574 if (cancel_work_sync(&old_notify->work)) {
575 /* Pending work had a ref, put that one too */
576 kref_put(&old_notify->kref, old_notify->release);
577 }
578 kref_put(&old_notify->kref, old_notify->release);
579 }
580
581 return 0;
582}
583EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
584
585#ifndef CONFIG_AUTO_IRQ_AFFINITY
586/*
587 * Generic version of the affinity autoselector.
588 */
589int irq_setup_affinity(struct irq_desc *desc)
590{
591 struct cpumask *set = irq_default_affinity;
592 int ret, node = irq_desc_get_node(desc);
593 static DEFINE_RAW_SPINLOCK(mask_lock);
594 static struct cpumask mask;
595
596 /* Excludes PER_CPU and NO_BALANCE interrupts */
597 if (!__irq_can_set_affinity(desc))
598 return 0;
599
600 raw_spin_lock(&mask_lock);
601 /*
602 * Preserve the managed affinity setting and a userspace affinity
603 * setup, but make sure that one of the targets is online.
604 */
605 if (irqd_affinity_is_managed(&desc->irq_data) ||
606 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
607 if (cpumask_intersects(desc->irq_common_data.affinity,
608 cpu_online_mask))
609 set = desc->irq_common_data.affinity;
610 else
611 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
612 }
613
614 cpumask_and(&mask, cpu_online_mask, set);
615 if (cpumask_empty(&mask))
616 cpumask_copy(&mask, cpu_online_mask);
617
618 if (node != NUMA_NO_NODE) {
619 const struct cpumask *nodemask = cpumask_of_node(node);
620
621 /* make sure at least one of the cpus in nodemask is online */
622 if (cpumask_intersects(&mask, nodemask))
623 cpumask_and(&mask, &mask, nodemask);
624 }
625 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
626 raw_spin_unlock(&mask_lock);
627 return ret;
628}
629#else
630/* Wrapper for ALPHA specific affinity selector magic */
631int irq_setup_affinity(struct irq_desc *desc)
632{
633 return irq_select_affinity(irq_desc_get_irq(desc));
634}
635#endif /* CONFIG_AUTO_IRQ_AFFINITY */
636#endif /* CONFIG_SMP */
637
638
639/**
640 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
641 * @irq: interrupt number to set affinity
642 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
643 * specific data for percpu_devid interrupts
644 *
645 * This function uses the vCPU specific data to set the vCPU
646 * affinity for an irq. The vCPU specific data is passed from
647 * outside, such as KVM. One example code path is as below:
648 * KVM -> IOMMU -> irq_set_vcpu_affinity().
649 */
650int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
651{
652 unsigned long flags;
653 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
654 struct irq_data *data;
655 struct irq_chip *chip;
656 int ret = -ENOSYS;
657
658 if (!desc)
659 return -EINVAL;
660
661 data = irq_desc_get_irq_data(desc);
662 do {
663 chip = irq_data_get_irq_chip(data);
664 if (chip && chip->irq_set_vcpu_affinity)
665 break;
666#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
667 data = data->parent_data;
668#else
669 data = NULL;
670#endif
671 } while (data);
672
673 if (data)
674 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
675 irq_put_desc_unlock(desc, flags);
676
677 return ret;
678}
679EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
680
681void __disable_irq(struct irq_desc *desc)
682{
683 if (!desc->depth++)
684 irq_disable(desc);
685}
686
687static int __disable_irq_nosync(unsigned int irq)
688{
689 unsigned long flags;
690 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
691
692 if (!desc)
693 return -EINVAL;
694 __disable_irq(desc);
695 irq_put_desc_busunlock(desc, flags);
696 return 0;
697}
698
699/**
700 * disable_irq_nosync - disable an irq without waiting
701 * @irq: Interrupt to disable
702 *
703 * Disable the selected interrupt line. Disables and Enables are
704 * nested.
705 * Unlike disable_irq(), this function does not ensure existing
706 * instances of the IRQ handler have completed before returning.
707 *
708 * This function may be called from IRQ context.
709 */
710void disable_irq_nosync(unsigned int irq)
711{
712 __disable_irq_nosync(irq);
713}
714EXPORT_SYMBOL(disable_irq_nosync);
715
716/**
717 * disable_irq - disable an irq and wait for completion
718 * @irq: Interrupt to disable
719 *
720 * Disable the selected interrupt line. Enables and Disables are
721 * nested.
722 * This function waits for any pending IRQ handlers for this interrupt
723 * to complete before returning. If you use this function while
724 * holding a resource the IRQ handler may need you will deadlock.
725 *
726 * This function may be called - with care - from IRQ context.
727 */
728void disable_irq(unsigned int irq)
729{
730 if (!__disable_irq_nosync(irq))
731 synchronize_irq(irq);
732}
733EXPORT_SYMBOL(disable_irq);
734
735/**
736 * disable_hardirq - disables an irq and waits for hardirq completion
737 * @irq: Interrupt to disable
738 *
739 * Disable the selected interrupt line. Enables and Disables are
740 * nested.
741 * This function waits for any pending hard IRQ handlers for this
742 * interrupt to complete before returning. If you use this function while
743 * holding a resource the hard IRQ handler may need you will deadlock.
744 *
745 * When used to optimistically disable an interrupt from atomic context
746 * the return value must be checked.
747 *
748 * Returns: false if a threaded handler is active.
749 *
750 * This function may be called - with care - from IRQ context.
751 */
752bool disable_hardirq(unsigned int irq)
753{
754 if (!__disable_irq_nosync(irq))
755 return synchronize_hardirq(irq);
756
757 return false;
758}
759EXPORT_SYMBOL_GPL(disable_hardirq);
760
761/**
762 * disable_nmi_nosync - disable an nmi without waiting
763 * @irq: Interrupt to disable
764 *
765 * Disable the selected interrupt line. Disables and enables are
766 * nested.
767 * The interrupt to disable must have been requested through request_nmi.
768 * Unlike disable_nmi(), this function does not ensure existing
769 * instances of the IRQ handler have completed before returning.
770 */
771void disable_nmi_nosync(unsigned int irq)
772{
773 disable_irq_nosync(irq);
774}
775
776void __enable_irq(struct irq_desc *desc)
777{
778 switch (desc->depth) {
779 case 0:
780 err_out:
781 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
782 irq_desc_get_irq(desc));
783 break;
784 case 1: {
785 if (desc->istate & IRQS_SUSPENDED)
786 goto err_out;
787 /* Prevent probing on this irq: */
788 irq_settings_set_noprobe(desc);
789 /*
790 * Call irq_startup() not irq_enable() here because the
791 * interrupt might be marked NOAUTOEN. So irq_startup()
792 * needs to be invoked when it gets enabled the first
793 * time. If it was already started up, then irq_startup()
794 * will invoke irq_enable() under the hood.
795 */
796 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
797 break;
798 }
799 default:
800 desc->depth--;
801 }
802}
803
804/**
805 * enable_irq - enable handling of an irq
806 * @irq: Interrupt to enable
807 *
808 * Undoes the effect of one call to disable_irq(). If this
809 * matches the last disable, processing of interrupts on this
810 * IRQ line is re-enabled.
811 *
812 * This function may be called from IRQ context only when
813 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
814 */
815void enable_irq(unsigned int irq)
816{
817 unsigned long flags;
818 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
819
820 if (!desc)
821 return;
822 if (WARN(!desc->irq_data.chip,
823 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
824 goto out;
825
826 __enable_irq(desc);
827out:
828 irq_put_desc_busunlock(desc, flags);
829}
830EXPORT_SYMBOL(enable_irq);
831
832/**
833 * enable_nmi - enable handling of an nmi
834 * @irq: Interrupt to enable
835 *
836 * The interrupt to enable must have been requested through request_nmi.
837 * Undoes the effect of one call to disable_nmi(). If this
838 * matches the last disable, processing of interrupts on this
839 * IRQ line is re-enabled.
840 */
841void enable_nmi(unsigned int irq)
842{
843 enable_irq(irq);
844}
845
846static int set_irq_wake_real(unsigned int irq, unsigned int on)
847{
848 struct irq_desc *desc = irq_to_desc(irq);
849 int ret = -ENXIO;
850
851 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
852 return 0;
853
854 if (desc->irq_data.chip->irq_set_wake)
855 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
856
857 return ret;
858}
859
860/**
861 * irq_set_irq_wake - control irq power management wakeup
862 * @irq: interrupt to control
863 * @on: enable/disable power management wakeup
864 *
865 * Enable/disable power management wakeup mode, which is
866 * disabled by default. Enables and disables must match,
867 * just as they match for non-wakeup mode support.
868 *
869 * Wakeup mode lets this IRQ wake the system from sleep
870 * states like "suspend to RAM".
871 *
872 * Note: irq enable/disable state is completely orthogonal
873 * to the enable/disable state of irq wake. An irq can be
874 * disabled with disable_irq() and still wake the system as
875 * long as the irq has wake enabled. If this does not hold,
876 * then the underlying irq chip and the related driver need
877 * to be investigated.
878 */
879int irq_set_irq_wake(unsigned int irq, unsigned int on)
880{
881 unsigned long flags;
882 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
883 int ret = 0;
884
885 if (!desc)
886 return -EINVAL;
887
888 /* Don't use NMIs as wake up interrupts please */
889 if (desc->istate & IRQS_NMI) {
890 ret = -EINVAL;
891 goto out_unlock;
892 }
893
894 /* wakeup-capable irqs can be shared between drivers that
895 * don't need to have the same sleep mode behaviors.
896 */
897 if (on) {
898 if (desc->wake_depth++ == 0) {
899 ret = set_irq_wake_real(irq, on);
900 if (ret)
901 desc->wake_depth = 0;
902 else
903 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
904 }
905 } else {
906 if (desc->wake_depth == 0) {
907 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
908 } else if (--desc->wake_depth == 0) {
909 ret = set_irq_wake_real(irq, on);
910 if (ret)
911 desc->wake_depth = 1;
912 else
913 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
914 }
915 }
916
917out_unlock:
918 irq_put_desc_busunlock(desc, flags);
919 return ret;
920}
921EXPORT_SYMBOL(irq_set_irq_wake);
922
923/*
924 * Internal function that tells the architecture code whether a
925 * particular irq has been exclusively allocated or is available
926 * for driver use.
927 */
928int can_request_irq(unsigned int irq, unsigned long irqflags)
929{
930 unsigned long flags;
931 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
932 int canrequest = 0;
933
934 if (!desc)
935 return 0;
936
937 if (irq_settings_can_request(desc)) {
938 if (!desc->action ||
939 irqflags & desc->action->flags & IRQF_SHARED)
940 canrequest = 1;
941 }
942 irq_put_desc_unlock(desc, flags);
943 return canrequest;
944}
945
946int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
947{
948 struct irq_chip *chip = desc->irq_data.chip;
949 int ret, unmask = 0;
950
951 if (!chip || !chip->irq_set_type) {
952 /*
953 * IRQF_TRIGGER_* but the PIC does not support multiple
954 * flow-types?
955 */
956 pr_debug("No set_type function for IRQ %d (%s)\n",
957 irq_desc_get_irq(desc),
958 chip ? (chip->name ? : "unknown") : "unknown");
959 return 0;
960 }
961
962 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
963 if (!irqd_irq_masked(&desc->irq_data))
964 mask_irq(desc);
965 if (!irqd_irq_disabled(&desc->irq_data))
966 unmask = 1;
967 }
968
969 /* Mask all flags except trigger mode */
970 flags &= IRQ_TYPE_SENSE_MASK;
971 ret = chip->irq_set_type(&desc->irq_data, flags);
972
973 switch (ret) {
974 case IRQ_SET_MASK_OK:
975 case IRQ_SET_MASK_OK_DONE:
976 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
977 irqd_set(&desc->irq_data, flags);
978 fallthrough;
979
980 case IRQ_SET_MASK_OK_NOCOPY:
981 flags = irqd_get_trigger_type(&desc->irq_data);
982 irq_settings_set_trigger_mask(desc, flags);
983 irqd_clear(&desc->irq_data, IRQD_LEVEL);
984 irq_settings_clr_level(desc);
985 if (flags & IRQ_TYPE_LEVEL_MASK) {
986 irq_settings_set_level(desc);
987 irqd_set(&desc->irq_data, IRQD_LEVEL);
988 }
989
990 ret = 0;
991 break;
992 default:
993 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
994 flags, irq_desc_get_irq(desc), chip->irq_set_type);
995 }
996 if (unmask)
997 unmask_irq(desc);
998 return ret;
999}
1000
1001#ifdef CONFIG_HARDIRQS_SW_RESEND
1002int irq_set_parent(int irq, int parent_irq)
1003{
1004 unsigned long flags;
1005 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1006
1007 if (!desc)
1008 return -EINVAL;
1009
1010 desc->parent_irq = parent_irq;
1011
1012 irq_put_desc_unlock(desc, flags);
1013 return 0;
1014}
1015EXPORT_SYMBOL_GPL(irq_set_parent);
1016#endif
1017
1018/*
1019 * Default primary interrupt handler for threaded interrupts. Is
1020 * assigned as primary handler when request_threaded_irq is called
1021 * with handler == NULL. Useful for oneshot interrupts.
1022 */
1023static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1024{
1025 return IRQ_WAKE_THREAD;
1026}
1027
1028/*
1029 * Primary handler for nested threaded interrupts. Should never be
1030 * called.
1031 */
1032static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1033{
1034 WARN(1, "Primary handler called for nested irq %d\n", irq);
1035 return IRQ_NONE;
1036}
1037
1038static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1039{
1040 WARN(1, "Secondary action handler called for irq %d\n", irq);
1041 return IRQ_NONE;
1042}
1043
1044static int irq_wait_for_interrupt(struct irqaction *action)
1045{
1046 for (;;) {
1047 set_current_state(TASK_INTERRUPTIBLE);
1048
1049 if (kthread_should_stop()) {
1050 /* may need to run one last time */
1051 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1052 &action->thread_flags)) {
1053 __set_current_state(TASK_RUNNING);
1054 return 0;
1055 }
1056 __set_current_state(TASK_RUNNING);
1057 return -1;
1058 }
1059
1060 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1061 &action->thread_flags)) {
1062 __set_current_state(TASK_RUNNING);
1063 return 0;
1064 }
1065 schedule();
1066 }
1067}
1068
1069/*
1070 * Oneshot interrupts keep the irq line masked until the threaded
1071 * handler finished. unmask if the interrupt has not been disabled and
1072 * is marked MASKED.
1073 */
1074static void irq_finalize_oneshot(struct irq_desc *desc,
1075 struct irqaction *action)
1076{
1077 if (!(desc->istate & IRQS_ONESHOT) ||
1078 action->handler == irq_forced_secondary_handler)
1079 return;
1080again:
1081 chip_bus_lock(desc);
1082 raw_spin_lock_irq(&desc->lock);
1083
1084 /*
1085 * Implausible though it may be we need to protect us against
1086 * the following scenario:
1087 *
1088 * The thread is faster done than the hard interrupt handler
1089 * on the other CPU. If we unmask the irq line then the
1090 * interrupt can come in again and masks the line, leaves due
1091 * to IRQS_INPROGRESS and the irq line is masked forever.
1092 *
1093 * This also serializes the state of shared oneshot handlers
1094 * versus "desc->threads_oneshot |= action->thread_mask;" in
1095 * irq_wake_thread(). See the comment there which explains the
1096 * serialization.
1097 */
1098 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1099 raw_spin_unlock_irq(&desc->lock);
1100 chip_bus_sync_unlock(desc);
1101 cpu_relax();
1102 goto again;
1103 }
1104
1105 /*
1106 * Now check again, whether the thread should run. Otherwise
1107 * we would clear the threads_oneshot bit of this thread which
1108 * was just set.
1109 */
1110 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1111 goto out_unlock;
1112
1113 desc->threads_oneshot &= ~action->thread_mask;
1114
1115 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1116 irqd_irq_masked(&desc->irq_data))
1117 unmask_threaded_irq(desc);
1118
1119out_unlock:
1120 raw_spin_unlock_irq(&desc->lock);
1121 chip_bus_sync_unlock(desc);
1122}
1123
1124#ifdef CONFIG_SMP
1125/*
1126 * Check whether we need to change the affinity of the interrupt thread.
1127 */
1128static void
1129irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1130{
1131 cpumask_var_t mask;
1132 bool valid = true;
1133
1134 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1135 return;
1136
1137 /*
1138 * In case we are out of memory we set IRQTF_AFFINITY again and
1139 * try again next time
1140 */
1141 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1142 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1143 return;
1144 }
1145
1146 raw_spin_lock_irq(&desc->lock);
1147 /*
1148 * This code is triggered unconditionally. Check the affinity
1149 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1150 */
1151 if (cpumask_available(desc->irq_common_data.affinity)) {
1152 const struct cpumask *m;
1153
1154 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1155 cpumask_copy(mask, m);
1156 } else {
1157 valid = false;
1158 }
1159 raw_spin_unlock_irq(&desc->lock);
1160
1161 if (valid)
1162 set_cpus_allowed_ptr(current, mask);
1163 free_cpumask_var(mask);
1164}
1165#else
1166static inline void
1167irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1168#endif
1169
1170/*
1171 * Interrupts which are not explicitly requested as threaded
1172 * interrupts rely on the implicit bh/preempt disable of the hard irq
1173 * context. So we need to disable bh here to avoid deadlocks and other
1174 * side effects.
1175 */
1176static irqreturn_t
1177irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1178{
1179 irqreturn_t ret;
1180
1181 local_bh_disable();
1182 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1183 local_irq_disable();
1184 ret = action->thread_fn(action->irq, action->dev_id);
1185 if (ret == IRQ_HANDLED)
1186 atomic_inc(&desc->threads_handled);
1187
1188 irq_finalize_oneshot(desc, action);
1189 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1190 local_irq_enable();
1191 local_bh_enable();
1192 return ret;
1193}
1194
1195/*
1196 * Interrupts explicitly requested as threaded interrupts want to be
1197 * preemptible - many of them need to sleep and wait for slow busses to
1198 * complete.
1199 */
1200static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1201 struct irqaction *action)
1202{
1203 irqreturn_t ret;
1204
1205 ret = action->thread_fn(action->irq, action->dev_id);
1206 if (ret == IRQ_HANDLED)
1207 atomic_inc(&desc->threads_handled);
1208
1209 irq_finalize_oneshot(desc, action);
1210 return ret;
1211}
1212
1213static void wake_threads_waitq(struct irq_desc *desc)
1214{
1215 if (atomic_dec_and_test(&desc->threads_active))
1216 wake_up(&desc->wait_for_threads);
1217}
1218
1219static void irq_thread_dtor(struct callback_head *unused)
1220{
1221 struct task_struct *tsk = current;
1222 struct irq_desc *desc;
1223 struct irqaction *action;
1224
1225 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1226 return;
1227
1228 action = kthread_data(tsk);
1229
1230 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1231 tsk->comm, tsk->pid, action->irq);
1232
1233
1234 desc = irq_to_desc(action->irq);
1235 /*
1236 * If IRQTF_RUNTHREAD is set, we need to decrement
1237 * desc->threads_active and wake possible waiters.
1238 */
1239 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1240 wake_threads_waitq(desc);
1241
1242 /* Prevent a stale desc->threads_oneshot */
1243 irq_finalize_oneshot(desc, action);
1244}
1245
1246static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1247{
1248 struct irqaction *secondary = action->secondary;
1249
1250 if (WARN_ON_ONCE(!secondary))
1251 return;
1252
1253 raw_spin_lock_irq(&desc->lock);
1254 __irq_wake_thread(desc, secondary);
1255 raw_spin_unlock_irq(&desc->lock);
1256}
1257
1258/*
1259 * Internal function to notify that a interrupt thread is ready.
1260 */
1261static void irq_thread_set_ready(struct irq_desc *desc,
1262 struct irqaction *action)
1263{
1264 set_bit(IRQTF_READY, &action->thread_flags);
1265 wake_up(&desc->wait_for_threads);
1266}
1267
1268/*
1269 * Internal function to wake up a interrupt thread and wait until it is
1270 * ready.
1271 */
1272static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1273 struct irqaction *action)
1274{
1275 if (!action || !action->thread)
1276 return;
1277
1278 wake_up_process(action->thread);
1279 wait_event(desc->wait_for_threads,
1280 test_bit(IRQTF_READY, &action->thread_flags));
1281}
1282
1283/*
1284 * Interrupt handler thread
1285 */
1286static int irq_thread(void *data)
1287{
1288 struct callback_head on_exit_work;
1289 struct irqaction *action = data;
1290 struct irq_desc *desc = irq_to_desc(action->irq);
1291 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1292 struct irqaction *action);
1293
1294 irq_thread_set_ready(desc, action);
1295
1296 sched_set_fifo(current);
1297
1298 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1299 &action->thread_flags))
1300 handler_fn = irq_forced_thread_fn;
1301 else
1302 handler_fn = irq_thread_fn;
1303
1304 init_task_work(&on_exit_work, irq_thread_dtor);
1305 task_work_add(current, &on_exit_work, TWA_NONE);
1306
1307 irq_thread_check_affinity(desc, action);
1308
1309 while (!irq_wait_for_interrupt(action)) {
1310 irqreturn_t action_ret;
1311
1312 irq_thread_check_affinity(desc, action);
1313
1314 action_ret = handler_fn(desc, action);
1315 if (action_ret == IRQ_WAKE_THREAD)
1316 irq_wake_secondary(desc, action);
1317
1318 wake_threads_waitq(desc);
1319 }
1320
1321 /*
1322 * This is the regular exit path. __free_irq() is stopping the
1323 * thread via kthread_stop() after calling
1324 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1325 * oneshot mask bit can be set.
1326 */
1327 task_work_cancel(current, irq_thread_dtor);
1328 return 0;
1329}
1330
1331/**
1332 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1333 * @irq: Interrupt line
1334 * @dev_id: Device identity for which the thread should be woken
1335 *
1336 */
1337void irq_wake_thread(unsigned int irq, void *dev_id)
1338{
1339 struct irq_desc *desc = irq_to_desc(irq);
1340 struct irqaction *action;
1341 unsigned long flags;
1342
1343 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1344 return;
1345
1346 raw_spin_lock_irqsave(&desc->lock, flags);
1347 for_each_action_of_desc(desc, action) {
1348 if (action->dev_id == dev_id) {
1349 if (action->thread)
1350 __irq_wake_thread(desc, action);
1351 break;
1352 }
1353 }
1354 raw_spin_unlock_irqrestore(&desc->lock, flags);
1355}
1356EXPORT_SYMBOL_GPL(irq_wake_thread);
1357
1358static int irq_setup_forced_threading(struct irqaction *new)
1359{
1360 if (!force_irqthreads())
1361 return 0;
1362 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1363 return 0;
1364
1365 /*
1366 * No further action required for interrupts which are requested as
1367 * threaded interrupts already
1368 */
1369 if (new->handler == irq_default_primary_handler)
1370 return 0;
1371
1372 new->flags |= IRQF_ONESHOT;
1373
1374 /*
1375 * Handle the case where we have a real primary handler and a
1376 * thread handler. We force thread them as well by creating a
1377 * secondary action.
1378 */
1379 if (new->handler && new->thread_fn) {
1380 /* Allocate the secondary action */
1381 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1382 if (!new->secondary)
1383 return -ENOMEM;
1384 new->secondary->handler = irq_forced_secondary_handler;
1385 new->secondary->thread_fn = new->thread_fn;
1386 new->secondary->dev_id = new->dev_id;
1387 new->secondary->irq = new->irq;
1388 new->secondary->name = new->name;
1389 }
1390 /* Deal with the primary handler */
1391 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1392 new->thread_fn = new->handler;
1393 new->handler = irq_default_primary_handler;
1394 return 0;
1395}
1396
1397static int irq_request_resources(struct irq_desc *desc)
1398{
1399 struct irq_data *d = &desc->irq_data;
1400 struct irq_chip *c = d->chip;
1401
1402 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1403}
1404
1405static void irq_release_resources(struct irq_desc *desc)
1406{
1407 struct irq_data *d = &desc->irq_data;
1408 struct irq_chip *c = d->chip;
1409
1410 if (c->irq_release_resources)
1411 c->irq_release_resources(d);
1412}
1413
1414static bool irq_supports_nmi(struct irq_desc *desc)
1415{
1416 struct irq_data *d = irq_desc_get_irq_data(desc);
1417
1418#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1419 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1420 if (d->parent_data)
1421 return false;
1422#endif
1423 /* Don't support NMIs for chips behind a slow bus */
1424 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1425 return false;
1426
1427 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1428}
1429
1430static int irq_nmi_setup(struct irq_desc *desc)
1431{
1432 struct irq_data *d = irq_desc_get_irq_data(desc);
1433 struct irq_chip *c = d->chip;
1434
1435 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1436}
1437
1438static void irq_nmi_teardown(struct irq_desc *desc)
1439{
1440 struct irq_data *d = irq_desc_get_irq_data(desc);
1441 struct irq_chip *c = d->chip;
1442
1443 if (c->irq_nmi_teardown)
1444 c->irq_nmi_teardown(d);
1445}
1446
1447static int
1448setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1449{
1450 struct task_struct *t;
1451
1452 if (!secondary) {
1453 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1454 new->name);
1455 } else {
1456 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1457 new->name);
1458 }
1459
1460 if (IS_ERR(t))
1461 return PTR_ERR(t);
1462
1463 /*
1464 * We keep the reference to the task struct even if
1465 * the thread dies to avoid that the interrupt code
1466 * references an already freed task_struct.
1467 */
1468 new->thread = get_task_struct(t);
1469 /*
1470 * Tell the thread to set its affinity. This is
1471 * important for shared interrupt handlers as we do
1472 * not invoke setup_affinity() for the secondary
1473 * handlers as everything is already set up. Even for
1474 * interrupts marked with IRQF_NO_BALANCE this is
1475 * correct as we want the thread to move to the cpu(s)
1476 * on which the requesting code placed the interrupt.
1477 */
1478 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1479 return 0;
1480}
1481
1482/*
1483 * Internal function to register an irqaction - typically used to
1484 * allocate special interrupts that are part of the architecture.
1485 *
1486 * Locking rules:
1487 *
1488 * desc->request_mutex Provides serialization against a concurrent free_irq()
1489 * chip_bus_lock Provides serialization for slow bus operations
1490 * desc->lock Provides serialization against hard interrupts
1491 *
1492 * chip_bus_lock and desc->lock are sufficient for all other management and
1493 * interrupt related functions. desc->request_mutex solely serializes
1494 * request/free_irq().
1495 */
1496static int
1497__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1498{
1499 struct irqaction *old, **old_ptr;
1500 unsigned long flags, thread_mask = 0;
1501 int ret, nested, shared = 0;
1502
1503 if (!desc)
1504 return -EINVAL;
1505
1506 if (desc->irq_data.chip == &no_irq_chip)
1507 return -ENOSYS;
1508 if (!try_module_get(desc->owner))
1509 return -ENODEV;
1510
1511 new->irq = irq;
1512
1513 /*
1514 * If the trigger type is not specified by the caller,
1515 * then use the default for this interrupt.
1516 */
1517 if (!(new->flags & IRQF_TRIGGER_MASK))
1518 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1519
1520 /*
1521 * Check whether the interrupt nests into another interrupt
1522 * thread.
1523 */
1524 nested = irq_settings_is_nested_thread(desc);
1525 if (nested) {
1526 if (!new->thread_fn) {
1527 ret = -EINVAL;
1528 goto out_mput;
1529 }
1530 /*
1531 * Replace the primary handler which was provided from
1532 * the driver for non nested interrupt handling by the
1533 * dummy function which warns when called.
1534 */
1535 new->handler = irq_nested_primary_handler;
1536 } else {
1537 if (irq_settings_can_thread(desc)) {
1538 ret = irq_setup_forced_threading(new);
1539 if (ret)
1540 goto out_mput;
1541 }
1542 }
1543
1544 /*
1545 * Create a handler thread when a thread function is supplied
1546 * and the interrupt does not nest into another interrupt
1547 * thread.
1548 */
1549 if (new->thread_fn && !nested) {
1550 ret = setup_irq_thread(new, irq, false);
1551 if (ret)
1552 goto out_mput;
1553 if (new->secondary) {
1554 ret = setup_irq_thread(new->secondary, irq, true);
1555 if (ret)
1556 goto out_thread;
1557 }
1558 }
1559
1560 /*
1561 * Drivers are often written to work w/o knowledge about the
1562 * underlying irq chip implementation, so a request for a
1563 * threaded irq without a primary hard irq context handler
1564 * requires the ONESHOT flag to be set. Some irq chips like
1565 * MSI based interrupts are per se one shot safe. Check the
1566 * chip flags, so we can avoid the unmask dance at the end of
1567 * the threaded handler for those.
1568 */
1569 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1570 new->flags &= ~IRQF_ONESHOT;
1571
1572 /*
1573 * Protects against a concurrent __free_irq() call which might wait
1574 * for synchronize_hardirq() to complete without holding the optional
1575 * chip bus lock and desc->lock. Also protects against handing out
1576 * a recycled oneshot thread_mask bit while it's still in use by
1577 * its previous owner.
1578 */
1579 mutex_lock(&desc->request_mutex);
1580
1581 /*
1582 * Acquire bus lock as the irq_request_resources() callback below
1583 * might rely on the serialization or the magic power management
1584 * functions which are abusing the irq_bus_lock() callback,
1585 */
1586 chip_bus_lock(desc);
1587
1588 /* First installed action requests resources. */
1589 if (!desc->action) {
1590 ret = irq_request_resources(desc);
1591 if (ret) {
1592 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1593 new->name, irq, desc->irq_data.chip->name);
1594 goto out_bus_unlock;
1595 }
1596 }
1597
1598 /*
1599 * The following block of code has to be executed atomically
1600 * protected against a concurrent interrupt and any of the other
1601 * management calls which are not serialized via
1602 * desc->request_mutex or the optional bus lock.
1603 */
1604 raw_spin_lock_irqsave(&desc->lock, flags);
1605 old_ptr = &desc->action;
1606 old = *old_ptr;
1607 if (old) {
1608 /*
1609 * Can't share interrupts unless both agree to and are
1610 * the same type (level, edge, polarity). So both flag
1611 * fields must have IRQF_SHARED set and the bits which
1612 * set the trigger type must match. Also all must
1613 * agree on ONESHOT.
1614 * Interrupt lines used for NMIs cannot be shared.
1615 */
1616 unsigned int oldtype;
1617
1618 if (desc->istate & IRQS_NMI) {
1619 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1620 new->name, irq, desc->irq_data.chip->name);
1621 ret = -EINVAL;
1622 goto out_unlock;
1623 }
1624
1625 /*
1626 * If nobody did set the configuration before, inherit
1627 * the one provided by the requester.
1628 */
1629 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1630 oldtype = irqd_get_trigger_type(&desc->irq_data);
1631 } else {
1632 oldtype = new->flags & IRQF_TRIGGER_MASK;
1633 irqd_set_trigger_type(&desc->irq_data, oldtype);
1634 }
1635
1636 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1637 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1638 ((old->flags ^ new->flags) & IRQF_ONESHOT))
1639 goto mismatch;
1640
1641 /* All handlers must agree on per-cpuness */
1642 if ((old->flags & IRQF_PERCPU) !=
1643 (new->flags & IRQF_PERCPU))
1644 goto mismatch;
1645
1646 /* add new interrupt at end of irq queue */
1647 do {
1648 /*
1649 * Or all existing action->thread_mask bits,
1650 * so we can find the next zero bit for this
1651 * new action.
1652 */
1653 thread_mask |= old->thread_mask;
1654 old_ptr = &old->next;
1655 old = *old_ptr;
1656 } while (old);
1657 shared = 1;
1658 }
1659
1660 /*
1661 * Setup the thread mask for this irqaction for ONESHOT. For
1662 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1663 * conditional in irq_wake_thread().
1664 */
1665 if (new->flags & IRQF_ONESHOT) {
1666 /*
1667 * Unlikely to have 32 resp 64 irqs sharing one line,
1668 * but who knows.
1669 */
1670 if (thread_mask == ~0UL) {
1671 ret = -EBUSY;
1672 goto out_unlock;
1673 }
1674 /*
1675 * The thread_mask for the action is or'ed to
1676 * desc->thread_active to indicate that the
1677 * IRQF_ONESHOT thread handler has been woken, but not
1678 * yet finished. The bit is cleared when a thread
1679 * completes. When all threads of a shared interrupt
1680 * line have completed desc->threads_active becomes
1681 * zero and the interrupt line is unmasked. See
1682 * handle.c:irq_wake_thread() for further information.
1683 *
1684 * If no thread is woken by primary (hard irq context)
1685 * interrupt handlers, then desc->threads_active is
1686 * also checked for zero to unmask the irq line in the
1687 * affected hard irq flow handlers
1688 * (handle_[fasteoi|level]_irq).
1689 *
1690 * The new action gets the first zero bit of
1691 * thread_mask assigned. See the loop above which or's
1692 * all existing action->thread_mask bits.
1693 */
1694 new->thread_mask = 1UL << ffz(thread_mask);
1695
1696 } else if (new->handler == irq_default_primary_handler &&
1697 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1698 /*
1699 * The interrupt was requested with handler = NULL, so
1700 * we use the default primary handler for it. But it
1701 * does not have the oneshot flag set. In combination
1702 * with level interrupts this is deadly, because the
1703 * default primary handler just wakes the thread, then
1704 * the irq lines is reenabled, but the device still
1705 * has the level irq asserted. Rinse and repeat....
1706 *
1707 * While this works for edge type interrupts, we play
1708 * it safe and reject unconditionally because we can't
1709 * say for sure which type this interrupt really
1710 * has. The type flags are unreliable as the
1711 * underlying chip implementation can override them.
1712 */
1713 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1714 new->name, irq);
1715 ret = -EINVAL;
1716 goto out_unlock;
1717 }
1718
1719 if (!shared) {
1720 /* Setup the type (level, edge polarity) if configured: */
1721 if (new->flags & IRQF_TRIGGER_MASK) {
1722 ret = __irq_set_trigger(desc,
1723 new->flags & IRQF_TRIGGER_MASK);
1724
1725 if (ret)
1726 goto out_unlock;
1727 }
1728
1729 /*
1730 * Activate the interrupt. That activation must happen
1731 * independently of IRQ_NOAUTOEN. request_irq() can fail
1732 * and the callers are supposed to handle
1733 * that. enable_irq() of an interrupt requested with
1734 * IRQ_NOAUTOEN is not supposed to fail. The activation
1735 * keeps it in shutdown mode, it merily associates
1736 * resources if necessary and if that's not possible it
1737 * fails. Interrupts which are in managed shutdown mode
1738 * will simply ignore that activation request.
1739 */
1740 ret = irq_activate(desc);
1741 if (ret)
1742 goto out_unlock;
1743
1744 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1745 IRQS_ONESHOT | IRQS_WAITING);
1746 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1747
1748 if (new->flags & IRQF_PERCPU) {
1749 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1750 irq_settings_set_per_cpu(desc);
1751 if (new->flags & IRQF_NO_DEBUG)
1752 irq_settings_set_no_debug(desc);
1753 }
1754
1755 if (noirqdebug)
1756 irq_settings_set_no_debug(desc);
1757
1758 if (new->flags & IRQF_ONESHOT)
1759 desc->istate |= IRQS_ONESHOT;
1760
1761 /* Exclude IRQ from balancing if requested */
1762 if (new->flags & IRQF_NOBALANCING) {
1763 irq_settings_set_no_balancing(desc);
1764 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1765 }
1766
1767 if (!(new->flags & IRQF_NO_AUTOEN) &&
1768 irq_settings_can_autoenable(desc)) {
1769 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1770 } else {
1771 /*
1772 * Shared interrupts do not go well with disabling
1773 * auto enable. The sharing interrupt might request
1774 * it while it's still disabled and then wait for
1775 * interrupts forever.
1776 */
1777 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1778 /* Undo nested disables: */
1779 desc->depth = 1;
1780 }
1781
1782 } else if (new->flags & IRQF_TRIGGER_MASK) {
1783 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1784 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1785
1786 if (nmsk != omsk)
1787 /* hope the handler works with current trigger mode */
1788 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1789 irq, omsk, nmsk);
1790 }
1791
1792 *old_ptr = new;
1793
1794 irq_pm_install_action(desc, new);
1795
1796 /* Reset broken irq detection when installing new handler */
1797 desc->irq_count = 0;
1798 desc->irqs_unhandled = 0;
1799
1800 /*
1801 * Check whether we disabled the irq via the spurious handler
1802 * before. Reenable it and give it another chance.
1803 */
1804 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1805 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1806 __enable_irq(desc);
1807 }
1808
1809 raw_spin_unlock_irqrestore(&desc->lock, flags);
1810 chip_bus_sync_unlock(desc);
1811 mutex_unlock(&desc->request_mutex);
1812
1813 irq_setup_timings(desc, new);
1814
1815 wake_up_and_wait_for_irq_thread_ready(desc, new);
1816 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1817
1818 register_irq_proc(irq, desc);
1819 new->dir = NULL;
1820 register_handler_proc(irq, new);
1821 return 0;
1822
1823mismatch:
1824 if (!(new->flags & IRQF_PROBE_SHARED)) {
1825 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1826 irq, new->flags, new->name, old->flags, old->name);
1827#ifdef CONFIG_DEBUG_SHIRQ
1828 dump_stack();
1829#endif
1830 }
1831 ret = -EBUSY;
1832
1833out_unlock:
1834 raw_spin_unlock_irqrestore(&desc->lock, flags);
1835
1836 if (!desc->action)
1837 irq_release_resources(desc);
1838out_bus_unlock:
1839 chip_bus_sync_unlock(desc);
1840 mutex_unlock(&desc->request_mutex);
1841
1842out_thread:
1843 if (new->thread) {
1844 struct task_struct *t = new->thread;
1845
1846 new->thread = NULL;
1847 kthread_stop(t);
1848 put_task_struct(t);
1849 }
1850 if (new->secondary && new->secondary->thread) {
1851 struct task_struct *t = new->secondary->thread;
1852
1853 new->secondary->thread = NULL;
1854 kthread_stop(t);
1855 put_task_struct(t);
1856 }
1857out_mput:
1858 module_put(desc->owner);
1859 return ret;
1860}
1861
1862/*
1863 * Internal function to unregister an irqaction - used to free
1864 * regular and special interrupts that are part of the architecture.
1865 */
1866static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1867{
1868 unsigned irq = desc->irq_data.irq;
1869 struct irqaction *action, **action_ptr;
1870 unsigned long flags;
1871
1872 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1873
1874 mutex_lock(&desc->request_mutex);
1875 chip_bus_lock(desc);
1876 raw_spin_lock_irqsave(&desc->lock, flags);
1877
1878 /*
1879 * There can be multiple actions per IRQ descriptor, find the right
1880 * one based on the dev_id:
1881 */
1882 action_ptr = &desc->action;
1883 for (;;) {
1884 action = *action_ptr;
1885
1886 if (!action) {
1887 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1888 raw_spin_unlock_irqrestore(&desc->lock, flags);
1889 chip_bus_sync_unlock(desc);
1890 mutex_unlock(&desc->request_mutex);
1891 return NULL;
1892 }
1893
1894 if (action->dev_id == dev_id)
1895 break;
1896 action_ptr = &action->next;
1897 }
1898
1899 /* Found it - now remove it from the list of entries: */
1900 *action_ptr = action->next;
1901
1902 irq_pm_remove_action(desc, action);
1903
1904 /* If this was the last handler, shut down the IRQ line: */
1905 if (!desc->action) {
1906 irq_settings_clr_disable_unlazy(desc);
1907 /* Only shutdown. Deactivate after synchronize_hardirq() */
1908 irq_shutdown(desc);
1909 }
1910
1911#ifdef CONFIG_SMP
1912 /* make sure affinity_hint is cleaned up */
1913 if (WARN_ON_ONCE(desc->affinity_hint))
1914 desc->affinity_hint = NULL;
1915#endif
1916
1917 raw_spin_unlock_irqrestore(&desc->lock, flags);
1918 /*
1919 * Drop bus_lock here so the changes which were done in the chip
1920 * callbacks above are synced out to the irq chips which hang
1921 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1922 *
1923 * Aside of that the bus_lock can also be taken from the threaded
1924 * handler in irq_finalize_oneshot() which results in a deadlock
1925 * because kthread_stop() would wait forever for the thread to
1926 * complete, which is blocked on the bus lock.
1927 *
1928 * The still held desc->request_mutex() protects against a
1929 * concurrent request_irq() of this irq so the release of resources
1930 * and timing data is properly serialized.
1931 */
1932 chip_bus_sync_unlock(desc);
1933
1934 unregister_handler_proc(irq, action);
1935
1936 /*
1937 * Make sure it's not being used on another CPU and if the chip
1938 * supports it also make sure that there is no (not yet serviced)
1939 * interrupt in flight at the hardware level.
1940 */
1941 __synchronize_hardirq(desc, true);
1942
1943#ifdef CONFIG_DEBUG_SHIRQ
1944 /*
1945 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1946 * event to happen even now it's being freed, so let's make sure that
1947 * is so by doing an extra call to the handler ....
1948 *
1949 * ( We do this after actually deregistering it, to make sure that a
1950 * 'real' IRQ doesn't run in parallel with our fake. )
1951 */
1952 if (action->flags & IRQF_SHARED) {
1953 local_irq_save(flags);
1954 action->handler(irq, dev_id);
1955 local_irq_restore(flags);
1956 }
1957#endif
1958
1959 /*
1960 * The action has already been removed above, but the thread writes
1961 * its oneshot mask bit when it completes. Though request_mutex is
1962 * held across this which prevents __setup_irq() from handing out
1963 * the same bit to a newly requested action.
1964 */
1965 if (action->thread) {
1966 kthread_stop(action->thread);
1967 put_task_struct(action->thread);
1968 if (action->secondary && action->secondary->thread) {
1969 kthread_stop(action->secondary->thread);
1970 put_task_struct(action->secondary->thread);
1971 }
1972 }
1973
1974 /* Last action releases resources */
1975 if (!desc->action) {
1976 /*
1977 * Reacquire bus lock as irq_release_resources() might
1978 * require it to deallocate resources over the slow bus.
1979 */
1980 chip_bus_lock(desc);
1981 /*
1982 * There is no interrupt on the fly anymore. Deactivate it
1983 * completely.
1984 */
1985 raw_spin_lock_irqsave(&desc->lock, flags);
1986 irq_domain_deactivate_irq(&desc->irq_data);
1987 raw_spin_unlock_irqrestore(&desc->lock, flags);
1988
1989 irq_release_resources(desc);
1990 chip_bus_sync_unlock(desc);
1991 irq_remove_timings(desc);
1992 }
1993
1994 mutex_unlock(&desc->request_mutex);
1995
1996 irq_chip_pm_put(&desc->irq_data);
1997 module_put(desc->owner);
1998 kfree(action->secondary);
1999 return action;
2000}
2001
2002/**
2003 * free_irq - free an interrupt allocated with request_irq
2004 * @irq: Interrupt line to free
2005 * @dev_id: Device identity to free
2006 *
2007 * Remove an interrupt handler. The handler is removed and if the
2008 * interrupt line is no longer in use by any driver it is disabled.
2009 * On a shared IRQ the caller must ensure the interrupt is disabled
2010 * on the card it drives before calling this function. The function
2011 * does not return until any executing interrupts for this IRQ
2012 * have completed.
2013 *
2014 * This function must not be called from interrupt context.
2015 *
2016 * Returns the devname argument passed to request_irq.
2017 */
2018const void *free_irq(unsigned int irq, void *dev_id)
2019{
2020 struct irq_desc *desc = irq_to_desc(irq);
2021 struct irqaction *action;
2022 const char *devname;
2023
2024 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2025 return NULL;
2026
2027#ifdef CONFIG_SMP
2028 if (WARN_ON(desc->affinity_notify))
2029 desc->affinity_notify = NULL;
2030#endif
2031
2032 action = __free_irq(desc, dev_id);
2033
2034 if (!action)
2035 return NULL;
2036
2037 devname = action->name;
2038 kfree(action);
2039 return devname;
2040}
2041EXPORT_SYMBOL(free_irq);
2042
2043/* This function must be called with desc->lock held */
2044static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2045{
2046 const char *devname = NULL;
2047
2048 desc->istate &= ~IRQS_NMI;
2049
2050 if (!WARN_ON(desc->action == NULL)) {
2051 irq_pm_remove_action(desc, desc->action);
2052 devname = desc->action->name;
2053 unregister_handler_proc(irq, desc->action);
2054
2055 kfree(desc->action);
2056 desc->action = NULL;
2057 }
2058
2059 irq_settings_clr_disable_unlazy(desc);
2060 irq_shutdown_and_deactivate(desc);
2061
2062 irq_release_resources(desc);
2063
2064 irq_chip_pm_put(&desc->irq_data);
2065 module_put(desc->owner);
2066
2067 return devname;
2068}
2069
2070const void *free_nmi(unsigned int irq, void *dev_id)
2071{
2072 struct irq_desc *desc = irq_to_desc(irq);
2073 unsigned long flags;
2074 const void *devname;
2075
2076 if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2077 return NULL;
2078
2079 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2080 return NULL;
2081
2082 /* NMI still enabled */
2083 if (WARN_ON(desc->depth == 0))
2084 disable_nmi_nosync(irq);
2085
2086 raw_spin_lock_irqsave(&desc->lock, flags);
2087
2088 irq_nmi_teardown(desc);
2089 devname = __cleanup_nmi(irq, desc);
2090
2091 raw_spin_unlock_irqrestore(&desc->lock, flags);
2092
2093 return devname;
2094}
2095
2096/**
2097 * request_threaded_irq - allocate an interrupt line
2098 * @irq: Interrupt line to allocate
2099 * @handler: Function to be called when the IRQ occurs.
2100 * Primary handler for threaded interrupts.
2101 * If handler is NULL and thread_fn != NULL
2102 * the default primary handler is installed.
2103 * @thread_fn: Function called from the irq handler thread
2104 * If NULL, no irq thread is created
2105 * @irqflags: Interrupt type flags
2106 * @devname: An ascii name for the claiming device
2107 * @dev_id: A cookie passed back to the handler function
2108 *
2109 * This call allocates interrupt resources and enables the
2110 * interrupt line and IRQ handling. From the point this
2111 * call is made your handler function may be invoked. Since
2112 * your handler function must clear any interrupt the board
2113 * raises, you must take care both to initialise your hardware
2114 * and to set up the interrupt handler in the right order.
2115 *
2116 * If you want to set up a threaded irq handler for your device
2117 * then you need to supply @handler and @thread_fn. @handler is
2118 * still called in hard interrupt context and has to check
2119 * whether the interrupt originates from the device. If yes it
2120 * needs to disable the interrupt on the device and return
2121 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2122 * @thread_fn. This split handler design is necessary to support
2123 * shared interrupts.
2124 *
2125 * Dev_id must be globally unique. Normally the address of the
2126 * device data structure is used as the cookie. Since the handler
2127 * receives this value it makes sense to use it.
2128 *
2129 * If your interrupt is shared you must pass a non NULL dev_id
2130 * as this is required when freeing the interrupt.
2131 *
2132 * Flags:
2133 *
2134 * IRQF_SHARED Interrupt is shared
2135 * IRQF_TRIGGER_* Specify active edge(s) or level
2136 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2137 */
2138int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2139 irq_handler_t thread_fn, unsigned long irqflags,
2140 const char *devname, void *dev_id)
2141{
2142 struct irqaction *action;
2143 struct irq_desc *desc;
2144 int retval;
2145
2146 if (irq == IRQ_NOTCONNECTED)
2147 return -ENOTCONN;
2148
2149 /*
2150 * Sanity-check: shared interrupts must pass in a real dev-ID,
2151 * otherwise we'll have trouble later trying to figure out
2152 * which interrupt is which (messes up the interrupt freeing
2153 * logic etc).
2154 *
2155 * Also shared interrupts do not go well with disabling auto enable.
2156 * The sharing interrupt might request it while it's still disabled
2157 * and then wait for interrupts forever.
2158 *
2159 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2160 * it cannot be set along with IRQF_NO_SUSPEND.
2161 */
2162 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2163 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2164 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2165 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2166 return -EINVAL;
2167
2168 desc = irq_to_desc(irq);
2169 if (!desc)
2170 return -EINVAL;
2171
2172 if (!irq_settings_can_request(desc) ||
2173 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2174 return -EINVAL;
2175
2176 if (!handler) {
2177 if (!thread_fn)
2178 return -EINVAL;
2179 handler = irq_default_primary_handler;
2180 }
2181
2182 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2183 if (!action)
2184 return -ENOMEM;
2185
2186 action->handler = handler;
2187 action->thread_fn = thread_fn;
2188 action->flags = irqflags;
2189 action->name = devname;
2190 action->dev_id = dev_id;
2191
2192 retval = irq_chip_pm_get(&desc->irq_data);
2193 if (retval < 0) {
2194 kfree(action);
2195 return retval;
2196 }
2197
2198 retval = __setup_irq(irq, desc, action);
2199
2200 if (retval) {
2201 irq_chip_pm_put(&desc->irq_data);
2202 kfree(action->secondary);
2203 kfree(action);
2204 }
2205
2206#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2207 if (!retval && (irqflags & IRQF_SHARED)) {
2208 /*
2209 * It's a shared IRQ -- the driver ought to be prepared for it
2210 * to happen immediately, so let's make sure....
2211 * We disable the irq to make sure that a 'real' IRQ doesn't
2212 * run in parallel with our fake.
2213 */
2214 unsigned long flags;
2215
2216 disable_irq(irq);
2217 local_irq_save(flags);
2218
2219 handler(irq, dev_id);
2220
2221 local_irq_restore(flags);
2222 enable_irq(irq);
2223 }
2224#endif
2225 return retval;
2226}
2227EXPORT_SYMBOL(request_threaded_irq);
2228
2229/**
2230 * request_any_context_irq - allocate an interrupt line
2231 * @irq: Interrupt line to allocate
2232 * @handler: Function to be called when the IRQ occurs.
2233 * Threaded handler for threaded interrupts.
2234 * @flags: Interrupt type flags
2235 * @name: An ascii name for the claiming device
2236 * @dev_id: A cookie passed back to the handler function
2237 *
2238 * This call allocates interrupt resources and enables the
2239 * interrupt line and IRQ handling. It selects either a
2240 * hardirq or threaded handling method depending on the
2241 * context.
2242 *
2243 * On failure, it returns a negative value. On success,
2244 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2245 */
2246int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2247 unsigned long flags, const char *name, void *dev_id)
2248{
2249 struct irq_desc *desc;
2250 int ret;
2251
2252 if (irq == IRQ_NOTCONNECTED)
2253 return -ENOTCONN;
2254
2255 desc = irq_to_desc(irq);
2256 if (!desc)
2257 return -EINVAL;
2258
2259 if (irq_settings_is_nested_thread(desc)) {
2260 ret = request_threaded_irq(irq, NULL, handler,
2261 flags, name, dev_id);
2262 return !ret ? IRQC_IS_NESTED : ret;
2263 }
2264
2265 ret = request_irq(irq, handler, flags, name, dev_id);
2266 return !ret ? IRQC_IS_HARDIRQ : ret;
2267}
2268EXPORT_SYMBOL_GPL(request_any_context_irq);
2269
2270/**
2271 * request_nmi - allocate an interrupt line for NMI delivery
2272 * @irq: Interrupt line to allocate
2273 * @handler: Function to be called when the IRQ occurs.
2274 * Threaded handler for threaded interrupts.
2275 * @irqflags: Interrupt type flags
2276 * @name: An ascii name for the claiming device
2277 * @dev_id: A cookie passed back to the handler function
2278 *
2279 * This call allocates interrupt resources and enables the
2280 * interrupt line and IRQ handling. It sets up the IRQ line
2281 * to be handled as an NMI.
2282 *
2283 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2284 * cannot be threaded.
2285 *
2286 * Interrupt lines requested for NMI delivering must produce per cpu
2287 * interrupts and have auto enabling setting disabled.
2288 *
2289 * Dev_id must be globally unique. Normally the address of the
2290 * device data structure is used as the cookie. Since the handler
2291 * receives this value it makes sense to use it.
2292 *
2293 * If the interrupt line cannot be used to deliver NMIs, function
2294 * will fail and return a negative value.
2295 */
2296int request_nmi(unsigned int irq, irq_handler_t handler,
2297 unsigned long irqflags, const char *name, void *dev_id)
2298{
2299 struct irqaction *action;
2300 struct irq_desc *desc;
2301 unsigned long flags;
2302 int retval;
2303
2304 if (irq == IRQ_NOTCONNECTED)
2305 return -ENOTCONN;
2306
2307 /* NMI cannot be shared, used for Polling */
2308 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2309 return -EINVAL;
2310
2311 if (!(irqflags & IRQF_PERCPU))
2312 return -EINVAL;
2313
2314 if (!handler)
2315 return -EINVAL;
2316
2317 desc = irq_to_desc(irq);
2318
2319 if (!desc || (irq_settings_can_autoenable(desc) &&
2320 !(irqflags & IRQF_NO_AUTOEN)) ||
2321 !irq_settings_can_request(desc) ||
2322 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2323 !irq_supports_nmi(desc))
2324 return -EINVAL;
2325
2326 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2327 if (!action)
2328 return -ENOMEM;
2329
2330 action->handler = handler;
2331 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2332 action->name = name;
2333 action->dev_id = dev_id;
2334
2335 retval = irq_chip_pm_get(&desc->irq_data);
2336 if (retval < 0)
2337 goto err_out;
2338
2339 retval = __setup_irq(irq, desc, action);
2340 if (retval)
2341 goto err_irq_setup;
2342
2343 raw_spin_lock_irqsave(&desc->lock, flags);
2344
2345 /* Setup NMI state */
2346 desc->istate |= IRQS_NMI;
2347 retval = irq_nmi_setup(desc);
2348 if (retval) {
2349 __cleanup_nmi(irq, desc);
2350 raw_spin_unlock_irqrestore(&desc->lock, flags);
2351 return -EINVAL;
2352 }
2353
2354 raw_spin_unlock_irqrestore(&desc->lock, flags);
2355
2356 return 0;
2357
2358err_irq_setup:
2359 irq_chip_pm_put(&desc->irq_data);
2360err_out:
2361 kfree(action);
2362
2363 return retval;
2364}
2365
2366void enable_percpu_irq(unsigned int irq, unsigned int type)
2367{
2368 unsigned int cpu = smp_processor_id();
2369 unsigned long flags;
2370 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2371
2372 if (!desc)
2373 return;
2374
2375 /*
2376 * If the trigger type is not specified by the caller, then
2377 * use the default for this interrupt.
2378 */
2379 type &= IRQ_TYPE_SENSE_MASK;
2380 if (type == IRQ_TYPE_NONE)
2381 type = irqd_get_trigger_type(&desc->irq_data);
2382
2383 if (type != IRQ_TYPE_NONE) {
2384 int ret;
2385
2386 ret = __irq_set_trigger(desc, type);
2387
2388 if (ret) {
2389 WARN(1, "failed to set type for IRQ%d\n", irq);
2390 goto out;
2391 }
2392 }
2393
2394 irq_percpu_enable(desc, cpu);
2395out:
2396 irq_put_desc_unlock(desc, flags);
2397}
2398EXPORT_SYMBOL_GPL(enable_percpu_irq);
2399
2400void enable_percpu_nmi(unsigned int irq, unsigned int type)
2401{
2402 enable_percpu_irq(irq, type);
2403}
2404
2405/**
2406 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2407 * @irq: Linux irq number to check for
2408 *
2409 * Must be called from a non migratable context. Returns the enable
2410 * state of a per cpu interrupt on the current cpu.
2411 */
2412bool irq_percpu_is_enabled(unsigned int irq)
2413{
2414 unsigned int cpu = smp_processor_id();
2415 struct irq_desc *desc;
2416 unsigned long flags;
2417 bool is_enabled;
2418
2419 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2420 if (!desc)
2421 return false;
2422
2423 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2424 irq_put_desc_unlock(desc, flags);
2425
2426 return is_enabled;
2427}
2428EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2429
2430void disable_percpu_irq(unsigned int irq)
2431{
2432 unsigned int cpu = smp_processor_id();
2433 unsigned long flags;
2434 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2435
2436 if (!desc)
2437 return;
2438
2439 irq_percpu_disable(desc, cpu);
2440 irq_put_desc_unlock(desc, flags);
2441}
2442EXPORT_SYMBOL_GPL(disable_percpu_irq);
2443
2444void disable_percpu_nmi(unsigned int irq)
2445{
2446 disable_percpu_irq(irq);
2447}
2448
2449/*
2450 * Internal function to unregister a percpu irqaction.
2451 */
2452static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2453{
2454 struct irq_desc *desc = irq_to_desc(irq);
2455 struct irqaction *action;
2456 unsigned long flags;
2457
2458 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2459
2460 if (!desc)
2461 return NULL;
2462
2463 raw_spin_lock_irqsave(&desc->lock, flags);
2464
2465 action = desc->action;
2466 if (!action || action->percpu_dev_id != dev_id) {
2467 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2468 goto bad;
2469 }
2470
2471 if (!cpumask_empty(desc->percpu_enabled)) {
2472 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2473 irq, cpumask_first(desc->percpu_enabled));
2474 goto bad;
2475 }
2476
2477 /* Found it - now remove it from the list of entries: */
2478 desc->action = NULL;
2479
2480 desc->istate &= ~IRQS_NMI;
2481
2482 raw_spin_unlock_irqrestore(&desc->lock, flags);
2483
2484 unregister_handler_proc(irq, action);
2485
2486 irq_chip_pm_put(&desc->irq_data);
2487 module_put(desc->owner);
2488 return action;
2489
2490bad:
2491 raw_spin_unlock_irqrestore(&desc->lock, flags);
2492 return NULL;
2493}
2494
2495/**
2496 * remove_percpu_irq - free a per-cpu interrupt
2497 * @irq: Interrupt line to free
2498 * @act: irqaction for the interrupt
2499 *
2500 * Used to remove interrupts statically setup by the early boot process.
2501 */
2502void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2503{
2504 struct irq_desc *desc = irq_to_desc(irq);
2505
2506 if (desc && irq_settings_is_per_cpu_devid(desc))
2507 __free_percpu_irq(irq, act->percpu_dev_id);
2508}
2509
2510/**
2511 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2512 * @irq: Interrupt line to free
2513 * @dev_id: Device identity to free
2514 *
2515 * Remove a percpu interrupt handler. The handler is removed, but
2516 * the interrupt line is not disabled. This must be done on each
2517 * CPU before calling this function. The function does not return
2518 * until any executing interrupts for this IRQ have completed.
2519 *
2520 * This function must not be called from interrupt context.
2521 */
2522void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2523{
2524 struct irq_desc *desc = irq_to_desc(irq);
2525
2526 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2527 return;
2528
2529 chip_bus_lock(desc);
2530 kfree(__free_percpu_irq(irq, dev_id));
2531 chip_bus_sync_unlock(desc);
2532}
2533EXPORT_SYMBOL_GPL(free_percpu_irq);
2534
2535void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2536{
2537 struct irq_desc *desc = irq_to_desc(irq);
2538
2539 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2540 return;
2541
2542 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2543 return;
2544
2545 kfree(__free_percpu_irq(irq, dev_id));
2546}
2547
2548/**
2549 * setup_percpu_irq - setup a per-cpu interrupt
2550 * @irq: Interrupt line to setup
2551 * @act: irqaction for the interrupt
2552 *
2553 * Used to statically setup per-cpu interrupts in the early boot process.
2554 */
2555int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2556{
2557 struct irq_desc *desc = irq_to_desc(irq);
2558 int retval;
2559
2560 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2561 return -EINVAL;
2562
2563 retval = irq_chip_pm_get(&desc->irq_data);
2564 if (retval < 0)
2565 return retval;
2566
2567 retval = __setup_irq(irq, desc, act);
2568
2569 if (retval)
2570 irq_chip_pm_put(&desc->irq_data);
2571
2572 return retval;
2573}
2574
2575/**
2576 * __request_percpu_irq - allocate a percpu interrupt line
2577 * @irq: Interrupt line to allocate
2578 * @handler: Function to be called when the IRQ occurs.
2579 * @flags: Interrupt type flags (IRQF_TIMER only)
2580 * @devname: An ascii name for the claiming device
2581 * @dev_id: A percpu cookie passed back to the handler function
2582 *
2583 * This call allocates interrupt resources and enables the
2584 * interrupt on the local CPU. If the interrupt is supposed to be
2585 * enabled on other CPUs, it has to be done on each CPU using
2586 * enable_percpu_irq().
2587 *
2588 * Dev_id must be globally unique. It is a per-cpu variable, and
2589 * the handler gets called with the interrupted CPU's instance of
2590 * that variable.
2591 */
2592int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2593 unsigned long flags, const char *devname,
2594 void __percpu *dev_id)
2595{
2596 struct irqaction *action;
2597 struct irq_desc *desc;
2598 int retval;
2599
2600 if (!dev_id)
2601 return -EINVAL;
2602
2603 desc = irq_to_desc(irq);
2604 if (!desc || !irq_settings_can_request(desc) ||
2605 !irq_settings_is_per_cpu_devid(desc))
2606 return -EINVAL;
2607
2608 if (flags && flags != IRQF_TIMER)
2609 return -EINVAL;
2610
2611 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2612 if (!action)
2613 return -ENOMEM;
2614
2615 action->handler = handler;
2616 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2617 action->name = devname;
2618 action->percpu_dev_id = dev_id;
2619
2620 retval = irq_chip_pm_get(&desc->irq_data);
2621 if (retval < 0) {
2622 kfree(action);
2623 return retval;
2624 }
2625
2626 retval = __setup_irq(irq, desc, action);
2627
2628 if (retval) {
2629 irq_chip_pm_put(&desc->irq_data);
2630 kfree(action);
2631 }
2632
2633 return retval;
2634}
2635EXPORT_SYMBOL_GPL(__request_percpu_irq);
2636
2637/**
2638 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2639 * @irq: Interrupt line to allocate
2640 * @handler: Function to be called when the IRQ occurs.
2641 * @name: An ascii name for the claiming device
2642 * @dev_id: A percpu cookie passed back to the handler function
2643 *
2644 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2645 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2646 * being enabled on the same CPU by using enable_percpu_nmi().
2647 *
2648 * Dev_id must be globally unique. It is a per-cpu variable, and
2649 * the handler gets called with the interrupted CPU's instance of
2650 * that variable.
2651 *
2652 * Interrupt lines requested for NMI delivering should have auto enabling
2653 * setting disabled.
2654 *
2655 * If the interrupt line cannot be used to deliver NMIs, function
2656 * will fail returning a negative value.
2657 */
2658int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2659 const char *name, void __percpu *dev_id)
2660{
2661 struct irqaction *action;
2662 struct irq_desc *desc;
2663 unsigned long flags;
2664 int retval;
2665
2666 if (!handler)
2667 return -EINVAL;
2668
2669 desc = irq_to_desc(irq);
2670
2671 if (!desc || !irq_settings_can_request(desc) ||
2672 !irq_settings_is_per_cpu_devid(desc) ||
2673 irq_settings_can_autoenable(desc) ||
2674 !irq_supports_nmi(desc))
2675 return -EINVAL;
2676
2677 /* The line cannot already be NMI */
2678 if (desc->istate & IRQS_NMI)
2679 return -EINVAL;
2680
2681 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2682 if (!action)
2683 return -ENOMEM;
2684
2685 action->handler = handler;
2686 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2687 | IRQF_NOBALANCING;
2688 action->name = name;
2689 action->percpu_dev_id = dev_id;
2690
2691 retval = irq_chip_pm_get(&desc->irq_data);
2692 if (retval < 0)
2693 goto err_out;
2694
2695 retval = __setup_irq(irq, desc, action);
2696 if (retval)
2697 goto err_irq_setup;
2698
2699 raw_spin_lock_irqsave(&desc->lock, flags);
2700 desc->istate |= IRQS_NMI;
2701 raw_spin_unlock_irqrestore(&desc->lock, flags);
2702
2703 return 0;
2704
2705err_irq_setup:
2706 irq_chip_pm_put(&desc->irq_data);
2707err_out:
2708 kfree(action);
2709
2710 return retval;
2711}
2712
2713/**
2714 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2715 * @irq: Interrupt line to prepare for NMI delivery
2716 *
2717 * This call prepares an interrupt line to deliver NMI on the current CPU,
2718 * before that interrupt line gets enabled with enable_percpu_nmi().
2719 *
2720 * As a CPU local operation, this should be called from non-preemptible
2721 * context.
2722 *
2723 * If the interrupt line cannot be used to deliver NMIs, function
2724 * will fail returning a negative value.
2725 */
2726int prepare_percpu_nmi(unsigned int irq)
2727{
2728 unsigned long flags;
2729 struct irq_desc *desc;
2730 int ret = 0;
2731
2732 WARN_ON(preemptible());
2733
2734 desc = irq_get_desc_lock(irq, &flags,
2735 IRQ_GET_DESC_CHECK_PERCPU);
2736 if (!desc)
2737 return -EINVAL;
2738
2739 if (WARN(!(desc->istate & IRQS_NMI),
2740 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2741 irq)) {
2742 ret = -EINVAL;
2743 goto out;
2744 }
2745
2746 ret = irq_nmi_setup(desc);
2747 if (ret) {
2748 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2749 goto out;
2750 }
2751
2752out:
2753 irq_put_desc_unlock(desc, flags);
2754 return ret;
2755}
2756
2757/**
2758 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2759 * @irq: Interrupt line from which CPU local NMI configuration should be
2760 * removed
2761 *
2762 * This call undoes the setup done by prepare_percpu_nmi().
2763 *
2764 * IRQ line should not be enabled for the current CPU.
2765 *
2766 * As a CPU local operation, this should be called from non-preemptible
2767 * context.
2768 */
2769void teardown_percpu_nmi(unsigned int irq)
2770{
2771 unsigned long flags;
2772 struct irq_desc *desc;
2773
2774 WARN_ON(preemptible());
2775
2776 desc = irq_get_desc_lock(irq, &flags,
2777 IRQ_GET_DESC_CHECK_PERCPU);
2778 if (!desc)
2779 return;
2780
2781 if (WARN_ON(!(desc->istate & IRQS_NMI)))
2782 goto out;
2783
2784 irq_nmi_teardown(desc);
2785out:
2786 irq_put_desc_unlock(desc, flags);
2787}
2788
2789int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2790 bool *state)
2791{
2792 struct irq_chip *chip;
2793 int err = -EINVAL;
2794
2795 do {
2796 chip = irq_data_get_irq_chip(data);
2797 if (WARN_ON_ONCE(!chip))
2798 return -ENODEV;
2799 if (chip->irq_get_irqchip_state)
2800 break;
2801#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2802 data = data->parent_data;
2803#else
2804 data = NULL;
2805#endif
2806 } while (data);
2807
2808 if (data)
2809 err = chip->irq_get_irqchip_state(data, which, state);
2810 return err;
2811}
2812
2813/**
2814 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2815 * @irq: Interrupt line that is forwarded to a VM
2816 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2817 * @state: a pointer to a boolean where the state is to be stored
2818 *
2819 * This call snapshots the internal irqchip state of an
2820 * interrupt, returning into @state the bit corresponding to
2821 * stage @which
2822 *
2823 * This function should be called with preemption disabled if the
2824 * interrupt controller has per-cpu registers.
2825 */
2826int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2827 bool *state)
2828{
2829 struct irq_desc *desc;
2830 struct irq_data *data;
2831 unsigned long flags;
2832 int err = -EINVAL;
2833
2834 desc = irq_get_desc_buslock(irq, &flags, 0);
2835 if (!desc)
2836 return err;
2837
2838 data = irq_desc_get_irq_data(desc);
2839
2840 err = __irq_get_irqchip_state(data, which, state);
2841
2842 irq_put_desc_busunlock(desc, flags);
2843 return err;
2844}
2845EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2846
2847/**
2848 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2849 * @irq: Interrupt line that is forwarded to a VM
2850 * @which: State to be restored (one of IRQCHIP_STATE_*)
2851 * @val: Value corresponding to @which
2852 *
2853 * This call sets the internal irqchip state of an interrupt,
2854 * depending on the value of @which.
2855 *
2856 * This function should be called with migration disabled if the
2857 * interrupt controller has per-cpu registers.
2858 */
2859int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2860 bool val)
2861{
2862 struct irq_desc *desc;
2863 struct irq_data *data;
2864 struct irq_chip *chip;
2865 unsigned long flags;
2866 int err = -EINVAL;
2867
2868 desc = irq_get_desc_buslock(irq, &flags, 0);
2869 if (!desc)
2870 return err;
2871
2872 data = irq_desc_get_irq_data(desc);
2873
2874 do {
2875 chip = irq_data_get_irq_chip(data);
2876 if (WARN_ON_ONCE(!chip)) {
2877 err = -ENODEV;
2878 goto out_unlock;
2879 }
2880 if (chip->irq_set_irqchip_state)
2881 break;
2882#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2883 data = data->parent_data;
2884#else
2885 data = NULL;
2886#endif
2887 } while (data);
2888
2889 if (data)
2890 err = chip->irq_set_irqchip_state(data, which, val);
2891
2892out_unlock:
2893 irq_put_desc_busunlock(desc, flags);
2894 return err;
2895}
2896EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2897
2898/**
2899 * irq_has_action - Check whether an interrupt is requested
2900 * @irq: The linux irq number
2901 *
2902 * Returns: A snapshot of the current state
2903 */
2904bool irq_has_action(unsigned int irq)
2905{
2906 bool res;
2907
2908 rcu_read_lock();
2909 res = irq_desc_has_action(irq_to_desc(irq));
2910 rcu_read_unlock();
2911 return res;
2912}
2913EXPORT_SYMBOL_GPL(irq_has_action);
2914
2915/**
2916 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2917 * @irq: The linux irq number
2918 * @bitmask: The bitmask to evaluate
2919 *
2920 * Returns: True if one of the bits in @bitmask is set
2921 */
2922bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2923{
2924 struct irq_desc *desc;
2925 bool res = false;
2926
2927 rcu_read_lock();
2928 desc = irq_to_desc(irq);
2929 if (desc)
2930 res = !!(desc->status_use_accessors & bitmask);
2931 rcu_read_unlock();
2932 return res;
2933}
2934EXPORT_SYMBOL_GPL(irq_check_status_bit);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4 * Copyright (C) 2005-2006 Thomas Gleixner
5 *
6 * This file contains driver APIs to the irq subsystem.
7 */
8
9#define pr_fmt(fmt) "genirq: " fmt
10
11#include <linux/irq.h>
12#include <linux/kthread.h>
13#include <linux/module.h>
14#include <linux/random.h>
15#include <linux/interrupt.h>
16#include <linux/irqdomain.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/sched/rt.h>
20#include <linux/sched/task.h>
21#include <linux/sched/isolation.h>
22#include <uapi/linux/sched/types.h>
23#include <linux/task_work.h>
24
25#include "internals.h"
26
27#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT)
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
221static DEFINE_PER_CPU(struct cpumask, __tmp_mask);
222
223int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
224 bool force)
225{
226 struct cpumask *tmp_mask = this_cpu_ptr(&__tmp_mask);
227 struct irq_desc *desc = irq_data_to_desc(data);
228 struct irq_chip *chip = irq_data_get_irq_chip(data);
229 const struct cpumask *prog_mask;
230 int ret;
231
232 if (!chip || !chip->irq_set_affinity)
233 return -EINVAL;
234
235 /*
236 * If this is a managed interrupt and housekeeping is enabled on
237 * it check whether the requested affinity mask intersects with
238 * a housekeeping CPU. If so, then remove the isolated CPUs from
239 * the mask and just keep the housekeeping CPU(s). This prevents
240 * the affinity setter from routing the interrupt to an isolated
241 * CPU to avoid that I/O submitted from a housekeeping CPU causes
242 * interrupts on an isolated one.
243 *
244 * If the masks do not intersect or include online CPU(s) then
245 * keep the requested mask. The isolated target CPUs are only
246 * receiving interrupts when the I/O operation was submitted
247 * directly from them.
248 *
249 * If all housekeeping CPUs in the affinity mask are offline, the
250 * interrupt will be migrated by the CPU hotplug code once a
251 * housekeeping CPU which belongs to the affinity mask comes
252 * online.
253 */
254 if (irqd_affinity_is_managed(data) &&
255 housekeeping_enabled(HK_TYPE_MANAGED_IRQ)) {
256 const struct cpumask *hk_mask;
257
258 hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ);
259
260 cpumask_and(tmp_mask, mask, hk_mask);
261 if (!cpumask_intersects(tmp_mask, cpu_online_mask))
262 prog_mask = mask;
263 else
264 prog_mask = tmp_mask;
265 } else {
266 prog_mask = mask;
267 }
268
269 /*
270 * Make sure we only provide online CPUs to the irqchip,
271 * unless we are being asked to force the affinity (in which
272 * case we do as we are told).
273 */
274 cpumask_and(tmp_mask, prog_mask, cpu_online_mask);
275 if (!force && !cpumask_empty(tmp_mask))
276 ret = chip->irq_set_affinity(data, tmp_mask, force);
277 else if (force)
278 ret = chip->irq_set_affinity(data, mask, force);
279 else
280 ret = -EINVAL;
281
282 switch (ret) {
283 case IRQ_SET_MASK_OK:
284 case IRQ_SET_MASK_OK_DONE:
285 cpumask_copy(desc->irq_common_data.affinity, mask);
286 fallthrough;
287 case IRQ_SET_MASK_OK_NOCOPY:
288 irq_validate_effective_affinity(data);
289 irq_set_thread_affinity(desc);
290 ret = 0;
291 }
292
293 return ret;
294}
295
296#ifdef CONFIG_GENERIC_PENDING_IRQ
297static inline int irq_set_affinity_pending(struct irq_data *data,
298 const struct cpumask *dest)
299{
300 struct irq_desc *desc = irq_data_to_desc(data);
301
302 irqd_set_move_pending(data);
303 irq_copy_pending(desc, dest);
304 return 0;
305}
306#else
307static inline int irq_set_affinity_pending(struct irq_data *data,
308 const struct cpumask *dest)
309{
310 return -EBUSY;
311}
312#endif
313
314static int irq_try_set_affinity(struct irq_data *data,
315 const struct cpumask *dest, bool force)
316{
317 int ret = irq_do_set_affinity(data, dest, force);
318
319 /*
320 * In case that the underlying vector management is busy and the
321 * architecture supports the generic pending mechanism then utilize
322 * this to avoid returning an error to user space.
323 */
324 if (ret == -EBUSY && !force)
325 ret = irq_set_affinity_pending(data, dest);
326 return ret;
327}
328
329static bool irq_set_affinity_deactivated(struct irq_data *data,
330 const struct cpumask *mask)
331{
332 struct irq_desc *desc = irq_data_to_desc(data);
333
334 /*
335 * Handle irq chips which can handle affinity only in activated
336 * state correctly
337 *
338 * If the interrupt is not yet activated, just store the affinity
339 * mask and do not call the chip driver at all. On activation the
340 * driver has to make sure anyway that the interrupt is in a
341 * usable state so startup works.
342 */
343 if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
344 irqd_is_activated(data) || !irqd_affinity_on_activate(data))
345 return false;
346
347 cpumask_copy(desc->irq_common_data.affinity, mask);
348 irq_data_update_effective_affinity(data, mask);
349 irqd_set(data, IRQD_AFFINITY_SET);
350 return true;
351}
352
353int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
354 bool force)
355{
356 struct irq_chip *chip = irq_data_get_irq_chip(data);
357 struct irq_desc *desc = irq_data_to_desc(data);
358 int ret = 0;
359
360 if (!chip || !chip->irq_set_affinity)
361 return -EINVAL;
362
363 if (irq_set_affinity_deactivated(data, mask))
364 return 0;
365
366 if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
367 ret = irq_try_set_affinity(data, mask, force);
368 } else {
369 irqd_set_move_pending(data);
370 irq_copy_pending(desc, mask);
371 }
372
373 if (desc->affinity_notify) {
374 kref_get(&desc->affinity_notify->kref);
375 if (!schedule_work(&desc->affinity_notify->work)) {
376 /* Work was already scheduled, drop our extra ref */
377 kref_put(&desc->affinity_notify->kref,
378 desc->affinity_notify->release);
379 }
380 }
381 irqd_set(data, IRQD_AFFINITY_SET);
382
383 return ret;
384}
385
386/**
387 * irq_update_affinity_desc - Update affinity management for an interrupt
388 * @irq: The interrupt number to update
389 * @affinity: Pointer to the affinity descriptor
390 *
391 * This interface can be used to configure the affinity management of
392 * interrupts which have been allocated already.
393 *
394 * There are certain limitations on when it may be used - attempts to use it
395 * for when the kernel is configured for generic IRQ reservation mode (in
396 * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
397 * managed/non-managed interrupt accounting. In addition, attempts to use it on
398 * an interrupt which is already started or which has already been configured
399 * as managed will also fail, as these mean invalid init state or double init.
400 */
401int irq_update_affinity_desc(unsigned int irq,
402 struct irq_affinity_desc *affinity)
403{
404 struct irq_desc *desc;
405 unsigned long flags;
406 bool activated;
407 int ret = 0;
408
409 /*
410 * Supporting this with the reservation scheme used by x86 needs
411 * some more thought. Fail it for now.
412 */
413 if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
414 return -EOPNOTSUPP;
415
416 desc = irq_get_desc_buslock(irq, &flags, 0);
417 if (!desc)
418 return -EINVAL;
419
420 /* Requires the interrupt to be shut down */
421 if (irqd_is_started(&desc->irq_data)) {
422 ret = -EBUSY;
423 goto out_unlock;
424 }
425
426 /* Interrupts which are already managed cannot be modified */
427 if (irqd_affinity_is_managed(&desc->irq_data)) {
428 ret = -EBUSY;
429 goto out_unlock;
430 }
431
432 /*
433 * Deactivate the interrupt. That's required to undo
434 * anything an earlier activation has established.
435 */
436 activated = irqd_is_activated(&desc->irq_data);
437 if (activated)
438 irq_domain_deactivate_irq(&desc->irq_data);
439
440 if (affinity->is_managed) {
441 irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
442 irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
443 }
444
445 cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
446
447 /* Restore the activation state */
448 if (activated)
449 irq_domain_activate_irq(&desc->irq_data, false);
450
451out_unlock:
452 irq_put_desc_busunlock(desc, flags);
453 return ret;
454}
455
456static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,
457 bool force)
458{
459 struct irq_desc *desc = irq_to_desc(irq);
460 unsigned long flags;
461 int ret;
462
463 if (!desc)
464 return -EINVAL;
465
466 raw_spin_lock_irqsave(&desc->lock, flags);
467 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
468 raw_spin_unlock_irqrestore(&desc->lock, flags);
469 return ret;
470}
471
472/**
473 * irq_set_affinity - Set the irq affinity of a given irq
474 * @irq: Interrupt to set affinity
475 * @cpumask: cpumask
476 *
477 * Fails if cpumask does not contain an online CPU
478 */
479int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
480{
481 return __irq_set_affinity(irq, cpumask, false);
482}
483EXPORT_SYMBOL_GPL(irq_set_affinity);
484
485/**
486 * irq_force_affinity - Force the irq affinity of a given irq
487 * @irq: Interrupt to set affinity
488 * @cpumask: cpumask
489 *
490 * Same as irq_set_affinity, but without checking the mask against
491 * online cpus.
492 *
493 * Solely for low level cpu hotplug code, where we need to make per
494 * cpu interrupts affine before the cpu becomes online.
495 */
496int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
497{
498 return __irq_set_affinity(irq, cpumask, true);
499}
500EXPORT_SYMBOL_GPL(irq_force_affinity);
501
502int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
503 bool setaffinity)
504{
505 unsigned long flags;
506 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
507
508 if (!desc)
509 return -EINVAL;
510 desc->affinity_hint = m;
511 irq_put_desc_unlock(desc, flags);
512 if (m && setaffinity)
513 __irq_set_affinity(irq, m, false);
514 return 0;
515}
516EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
517
518static void irq_affinity_notify(struct work_struct *work)
519{
520 struct irq_affinity_notify *notify =
521 container_of(work, struct irq_affinity_notify, work);
522 struct irq_desc *desc = irq_to_desc(notify->irq);
523 cpumask_var_t cpumask;
524 unsigned long flags;
525
526 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
527 goto out;
528
529 raw_spin_lock_irqsave(&desc->lock, flags);
530 if (irq_move_pending(&desc->irq_data))
531 irq_get_pending(cpumask, desc);
532 else
533 cpumask_copy(cpumask, desc->irq_common_data.affinity);
534 raw_spin_unlock_irqrestore(&desc->lock, flags);
535
536 notify->notify(notify, cpumask);
537
538 free_cpumask_var(cpumask);
539out:
540 kref_put(¬ify->kref, notify->release);
541}
542
543/**
544 * irq_set_affinity_notifier - control notification of IRQ affinity changes
545 * @irq: Interrupt for which to enable/disable notification
546 * @notify: Context for notification, or %NULL to disable
547 * notification. Function pointers must be initialised;
548 * the other fields will be initialised by this function.
549 *
550 * Must be called in process context. Notification may only be enabled
551 * after the IRQ is allocated and must be disabled before the IRQ is
552 * freed using free_irq().
553 */
554int
555irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
556{
557 struct irq_desc *desc = irq_to_desc(irq);
558 struct irq_affinity_notify *old_notify;
559 unsigned long flags;
560
561 /* The release function is promised process context */
562 might_sleep();
563
564 if (!desc || irq_is_nmi(desc))
565 return -EINVAL;
566
567 /* Complete initialisation of *notify */
568 if (notify) {
569 notify->irq = irq;
570 kref_init(¬ify->kref);
571 INIT_WORK(¬ify->work, irq_affinity_notify);
572 }
573
574 raw_spin_lock_irqsave(&desc->lock, flags);
575 old_notify = desc->affinity_notify;
576 desc->affinity_notify = notify;
577 raw_spin_unlock_irqrestore(&desc->lock, flags);
578
579 if (old_notify) {
580 if (cancel_work_sync(&old_notify->work)) {
581 /* Pending work had a ref, put that one too */
582 kref_put(&old_notify->kref, old_notify->release);
583 }
584 kref_put(&old_notify->kref, old_notify->release);
585 }
586
587 return 0;
588}
589EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
590
591#ifndef CONFIG_AUTO_IRQ_AFFINITY
592/*
593 * Generic version of the affinity autoselector.
594 */
595int irq_setup_affinity(struct irq_desc *desc)
596{
597 struct cpumask *set = irq_default_affinity;
598 int ret, node = irq_desc_get_node(desc);
599 static DEFINE_RAW_SPINLOCK(mask_lock);
600 static struct cpumask mask;
601
602 /* Excludes PER_CPU and NO_BALANCE interrupts */
603 if (!__irq_can_set_affinity(desc))
604 return 0;
605
606 raw_spin_lock(&mask_lock);
607 /*
608 * Preserve the managed affinity setting and a userspace affinity
609 * setup, but make sure that one of the targets is online.
610 */
611 if (irqd_affinity_is_managed(&desc->irq_data) ||
612 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
613 if (cpumask_intersects(desc->irq_common_data.affinity,
614 cpu_online_mask))
615 set = desc->irq_common_data.affinity;
616 else
617 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
618 }
619
620 cpumask_and(&mask, cpu_online_mask, set);
621 if (cpumask_empty(&mask))
622 cpumask_copy(&mask, cpu_online_mask);
623
624 if (node != NUMA_NO_NODE) {
625 const struct cpumask *nodemask = cpumask_of_node(node);
626
627 /* make sure at least one of the cpus in nodemask is online */
628 if (cpumask_intersects(&mask, nodemask))
629 cpumask_and(&mask, &mask, nodemask);
630 }
631 ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
632 raw_spin_unlock(&mask_lock);
633 return ret;
634}
635#else
636/* Wrapper for ALPHA specific affinity selector magic */
637int irq_setup_affinity(struct irq_desc *desc)
638{
639 return irq_select_affinity(irq_desc_get_irq(desc));
640}
641#endif /* CONFIG_AUTO_IRQ_AFFINITY */
642#endif /* CONFIG_SMP */
643
644
645/**
646 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
647 * @irq: interrupt number to set affinity
648 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
649 * specific data for percpu_devid interrupts
650 *
651 * This function uses the vCPU specific data to set the vCPU
652 * affinity for an irq. The vCPU specific data is passed from
653 * outside, such as KVM. One example code path is as below:
654 * KVM -> IOMMU -> irq_set_vcpu_affinity().
655 */
656int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
657{
658 unsigned long flags;
659 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
660 struct irq_data *data;
661 struct irq_chip *chip;
662 int ret = -ENOSYS;
663
664 if (!desc)
665 return -EINVAL;
666
667 data = irq_desc_get_irq_data(desc);
668 do {
669 chip = irq_data_get_irq_chip(data);
670 if (chip && chip->irq_set_vcpu_affinity)
671 break;
672#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
673 data = data->parent_data;
674#else
675 data = NULL;
676#endif
677 } while (data);
678
679 if (data)
680 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
681 irq_put_desc_unlock(desc, flags);
682
683 return ret;
684}
685EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
686
687void __disable_irq(struct irq_desc *desc)
688{
689 if (!desc->depth++)
690 irq_disable(desc);
691}
692
693static int __disable_irq_nosync(unsigned int irq)
694{
695 unsigned long flags;
696 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
697
698 if (!desc)
699 return -EINVAL;
700 __disable_irq(desc);
701 irq_put_desc_busunlock(desc, flags);
702 return 0;
703}
704
705/**
706 * disable_irq_nosync - disable an irq without waiting
707 * @irq: Interrupt to disable
708 *
709 * Disable the selected interrupt line. Disables and Enables are
710 * nested.
711 * Unlike disable_irq(), this function does not ensure existing
712 * instances of the IRQ handler have completed before returning.
713 *
714 * This function may be called from IRQ context.
715 */
716void disable_irq_nosync(unsigned int irq)
717{
718 __disable_irq_nosync(irq);
719}
720EXPORT_SYMBOL(disable_irq_nosync);
721
722/**
723 * disable_irq - disable an irq and wait for completion
724 * @irq: Interrupt to disable
725 *
726 * Disable the selected interrupt line. Enables and Disables are
727 * nested.
728 * This function waits for any pending IRQ handlers for this interrupt
729 * to complete before returning. If you use this function while
730 * holding a resource the IRQ handler may need you will deadlock.
731 *
732 * Can only be called from preemptible code as it might sleep when
733 * an interrupt thread is associated to @irq.
734 *
735 */
736void disable_irq(unsigned int irq)
737{
738 might_sleep();
739 if (!__disable_irq_nosync(irq))
740 synchronize_irq(irq);
741}
742EXPORT_SYMBOL(disable_irq);
743
744/**
745 * disable_hardirq - disables an irq and waits for hardirq completion
746 * @irq: Interrupt to disable
747 *
748 * Disable the selected interrupt line. Enables and Disables are
749 * nested.
750 * This function waits for any pending hard IRQ handlers for this
751 * interrupt to complete before returning. If you use this function while
752 * holding a resource the hard IRQ handler may need you will deadlock.
753 *
754 * When used to optimistically disable an interrupt from atomic context
755 * the return value must be checked.
756 *
757 * Returns: false if a threaded handler is active.
758 *
759 * This function may be called - with care - from IRQ context.
760 */
761bool disable_hardirq(unsigned int irq)
762{
763 if (!__disable_irq_nosync(irq))
764 return synchronize_hardirq(irq);
765
766 return false;
767}
768EXPORT_SYMBOL_GPL(disable_hardirq);
769
770/**
771 * disable_nmi_nosync - disable an nmi without waiting
772 * @irq: Interrupt to disable
773 *
774 * Disable the selected interrupt line. Disables and enables are
775 * nested.
776 * The interrupt to disable must have been requested through request_nmi.
777 * Unlike disable_nmi(), this function does not ensure existing
778 * instances of the IRQ handler have completed before returning.
779 */
780void disable_nmi_nosync(unsigned int irq)
781{
782 disable_irq_nosync(irq);
783}
784
785void __enable_irq(struct irq_desc *desc)
786{
787 switch (desc->depth) {
788 case 0:
789 err_out:
790 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
791 irq_desc_get_irq(desc));
792 break;
793 case 1: {
794 if (desc->istate & IRQS_SUSPENDED)
795 goto err_out;
796 /* Prevent probing on this irq: */
797 irq_settings_set_noprobe(desc);
798 /*
799 * Call irq_startup() not irq_enable() here because the
800 * interrupt might be marked NOAUTOEN so irq_startup()
801 * needs to be invoked when it gets enabled the first time.
802 * This is also required when __enable_irq() is invoked for
803 * a managed and shutdown interrupt from the S3 resume
804 * path.
805 *
806 * If it was already started up, then irq_startup() will
807 * invoke irq_enable() under the hood.
808 */
809 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
810 break;
811 }
812 default:
813 desc->depth--;
814 }
815}
816
817/**
818 * enable_irq - enable handling of an irq
819 * @irq: Interrupt to enable
820 *
821 * Undoes the effect of one call to disable_irq(). If this
822 * matches the last disable, processing of interrupts on this
823 * IRQ line is re-enabled.
824 *
825 * This function may be called from IRQ context only when
826 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
827 */
828void enable_irq(unsigned int irq)
829{
830 unsigned long flags;
831 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
832
833 if (!desc)
834 return;
835 if (WARN(!desc->irq_data.chip,
836 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
837 goto out;
838
839 __enable_irq(desc);
840out:
841 irq_put_desc_busunlock(desc, flags);
842}
843EXPORT_SYMBOL(enable_irq);
844
845/**
846 * enable_nmi - enable handling of an nmi
847 * @irq: Interrupt to enable
848 *
849 * The interrupt to enable must have been requested through request_nmi.
850 * Undoes the effect of one call to disable_nmi(). If this
851 * matches the last disable, processing of interrupts on this
852 * IRQ line is re-enabled.
853 */
854void enable_nmi(unsigned int irq)
855{
856 enable_irq(irq);
857}
858
859static int set_irq_wake_real(unsigned int irq, unsigned int on)
860{
861 struct irq_desc *desc = irq_to_desc(irq);
862 int ret = -ENXIO;
863
864 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
865 return 0;
866
867 if (desc->irq_data.chip->irq_set_wake)
868 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
869
870 return ret;
871}
872
873/**
874 * irq_set_irq_wake - control irq power management wakeup
875 * @irq: interrupt to control
876 * @on: enable/disable power management wakeup
877 *
878 * Enable/disable power management wakeup mode, which is
879 * disabled by default. Enables and disables must match,
880 * just as they match for non-wakeup mode support.
881 *
882 * Wakeup mode lets this IRQ wake the system from sleep
883 * states like "suspend to RAM".
884 *
885 * Note: irq enable/disable state is completely orthogonal
886 * to the enable/disable state of irq wake. An irq can be
887 * disabled with disable_irq() and still wake the system as
888 * long as the irq has wake enabled. If this does not hold,
889 * then the underlying irq chip and the related driver need
890 * to be investigated.
891 */
892int irq_set_irq_wake(unsigned int irq, unsigned int on)
893{
894 unsigned long flags;
895 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
896 int ret = 0;
897
898 if (!desc)
899 return -EINVAL;
900
901 /* Don't use NMIs as wake up interrupts please */
902 if (irq_is_nmi(desc)) {
903 ret = -EINVAL;
904 goto out_unlock;
905 }
906
907 /* wakeup-capable irqs can be shared between drivers that
908 * don't need to have the same sleep mode behaviors.
909 */
910 if (on) {
911 if (desc->wake_depth++ == 0) {
912 ret = set_irq_wake_real(irq, on);
913 if (ret)
914 desc->wake_depth = 0;
915 else
916 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
917 }
918 } else {
919 if (desc->wake_depth == 0) {
920 WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
921 } else if (--desc->wake_depth == 0) {
922 ret = set_irq_wake_real(irq, on);
923 if (ret)
924 desc->wake_depth = 1;
925 else
926 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
927 }
928 }
929
930out_unlock:
931 irq_put_desc_busunlock(desc, flags);
932 return ret;
933}
934EXPORT_SYMBOL(irq_set_irq_wake);
935
936/*
937 * Internal function that tells the architecture code whether a
938 * particular irq has been exclusively allocated or is available
939 * for driver use.
940 */
941int can_request_irq(unsigned int irq, unsigned long irqflags)
942{
943 unsigned long flags;
944 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
945 int canrequest = 0;
946
947 if (!desc)
948 return 0;
949
950 if (irq_settings_can_request(desc)) {
951 if (!desc->action ||
952 irqflags & desc->action->flags & IRQF_SHARED)
953 canrequest = 1;
954 }
955 irq_put_desc_unlock(desc, flags);
956 return canrequest;
957}
958
959int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
960{
961 struct irq_chip *chip = desc->irq_data.chip;
962 int ret, unmask = 0;
963
964 if (!chip || !chip->irq_set_type) {
965 /*
966 * IRQF_TRIGGER_* but the PIC does not support multiple
967 * flow-types?
968 */
969 pr_debug("No set_type function for IRQ %d (%s)\n",
970 irq_desc_get_irq(desc),
971 chip ? (chip->name ? : "unknown") : "unknown");
972 return 0;
973 }
974
975 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
976 if (!irqd_irq_masked(&desc->irq_data))
977 mask_irq(desc);
978 if (!irqd_irq_disabled(&desc->irq_data))
979 unmask = 1;
980 }
981
982 /* Mask all flags except trigger mode */
983 flags &= IRQ_TYPE_SENSE_MASK;
984 ret = chip->irq_set_type(&desc->irq_data, flags);
985
986 switch (ret) {
987 case IRQ_SET_MASK_OK:
988 case IRQ_SET_MASK_OK_DONE:
989 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
990 irqd_set(&desc->irq_data, flags);
991 fallthrough;
992
993 case IRQ_SET_MASK_OK_NOCOPY:
994 flags = irqd_get_trigger_type(&desc->irq_data);
995 irq_settings_set_trigger_mask(desc, flags);
996 irqd_clear(&desc->irq_data, IRQD_LEVEL);
997 irq_settings_clr_level(desc);
998 if (flags & IRQ_TYPE_LEVEL_MASK) {
999 irq_settings_set_level(desc);
1000 irqd_set(&desc->irq_data, IRQD_LEVEL);
1001 }
1002
1003 ret = 0;
1004 break;
1005 default:
1006 pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
1007 flags, irq_desc_get_irq(desc), chip->irq_set_type);
1008 }
1009 if (unmask)
1010 unmask_irq(desc);
1011 return ret;
1012}
1013
1014#ifdef CONFIG_HARDIRQS_SW_RESEND
1015int irq_set_parent(int irq, int parent_irq)
1016{
1017 unsigned long flags;
1018 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
1019
1020 if (!desc)
1021 return -EINVAL;
1022
1023 desc->parent_irq = parent_irq;
1024
1025 irq_put_desc_unlock(desc, flags);
1026 return 0;
1027}
1028EXPORT_SYMBOL_GPL(irq_set_parent);
1029#endif
1030
1031/*
1032 * Default primary interrupt handler for threaded interrupts. Is
1033 * assigned as primary handler when request_threaded_irq is called
1034 * with handler == NULL. Useful for oneshot interrupts.
1035 */
1036static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
1037{
1038 return IRQ_WAKE_THREAD;
1039}
1040
1041/*
1042 * Primary handler for nested threaded interrupts. Should never be
1043 * called.
1044 */
1045static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
1046{
1047 WARN(1, "Primary handler called for nested irq %d\n", irq);
1048 return IRQ_NONE;
1049}
1050
1051static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1052{
1053 WARN(1, "Secondary action handler called for irq %d\n", irq);
1054 return IRQ_NONE;
1055}
1056
1057#ifdef CONFIG_SMP
1058/*
1059 * Check whether we need to change the affinity of the interrupt thread.
1060 */
1061static void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1062{
1063 cpumask_var_t mask;
1064 bool valid = false;
1065
1066 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1067 return;
1068
1069 __set_current_state(TASK_RUNNING);
1070
1071 /*
1072 * In case we are out of memory we set IRQTF_AFFINITY again and
1073 * try again next time
1074 */
1075 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1076 set_bit(IRQTF_AFFINITY, &action->thread_flags);
1077 return;
1078 }
1079
1080 raw_spin_lock_irq(&desc->lock);
1081 /*
1082 * This code is triggered unconditionally. Check the affinity
1083 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1084 */
1085 if (cpumask_available(desc->irq_common_data.affinity)) {
1086 const struct cpumask *m;
1087
1088 m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1089 cpumask_copy(mask, m);
1090 valid = true;
1091 }
1092 raw_spin_unlock_irq(&desc->lock);
1093
1094 if (valid)
1095 set_cpus_allowed_ptr(current, mask);
1096 free_cpumask_var(mask);
1097}
1098#else
1099static inline void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1100#endif
1101
1102static int irq_wait_for_interrupt(struct irq_desc *desc,
1103 struct irqaction *action)
1104{
1105 for (;;) {
1106 set_current_state(TASK_INTERRUPTIBLE);
1107 irq_thread_check_affinity(desc, action);
1108
1109 if (kthread_should_stop()) {
1110 /* may need to run one last time */
1111 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1112 &action->thread_flags)) {
1113 __set_current_state(TASK_RUNNING);
1114 return 0;
1115 }
1116 __set_current_state(TASK_RUNNING);
1117 return -1;
1118 }
1119
1120 if (test_and_clear_bit(IRQTF_RUNTHREAD,
1121 &action->thread_flags)) {
1122 __set_current_state(TASK_RUNNING);
1123 return 0;
1124 }
1125 schedule();
1126 }
1127}
1128
1129/*
1130 * Oneshot interrupts keep the irq line masked until the threaded
1131 * handler finished. unmask if the interrupt has not been disabled and
1132 * is marked MASKED.
1133 */
1134static void irq_finalize_oneshot(struct irq_desc *desc,
1135 struct irqaction *action)
1136{
1137 if (!(desc->istate & IRQS_ONESHOT) ||
1138 action->handler == irq_forced_secondary_handler)
1139 return;
1140again:
1141 chip_bus_lock(desc);
1142 raw_spin_lock_irq(&desc->lock);
1143
1144 /*
1145 * Implausible though it may be we need to protect us against
1146 * the following scenario:
1147 *
1148 * The thread is faster done than the hard interrupt handler
1149 * on the other CPU. If we unmask the irq line then the
1150 * interrupt can come in again and masks the line, leaves due
1151 * to IRQS_INPROGRESS and the irq line is masked forever.
1152 *
1153 * This also serializes the state of shared oneshot handlers
1154 * versus "desc->threads_oneshot |= action->thread_mask;" in
1155 * irq_wake_thread(). See the comment there which explains the
1156 * serialization.
1157 */
1158 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1159 raw_spin_unlock_irq(&desc->lock);
1160 chip_bus_sync_unlock(desc);
1161 cpu_relax();
1162 goto again;
1163 }
1164
1165 /*
1166 * Now check again, whether the thread should run. Otherwise
1167 * we would clear the threads_oneshot bit of this thread which
1168 * was just set.
1169 */
1170 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1171 goto out_unlock;
1172
1173 desc->threads_oneshot &= ~action->thread_mask;
1174
1175 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1176 irqd_irq_masked(&desc->irq_data))
1177 unmask_threaded_irq(desc);
1178
1179out_unlock:
1180 raw_spin_unlock_irq(&desc->lock);
1181 chip_bus_sync_unlock(desc);
1182}
1183
1184/*
1185 * Interrupts which are not explicitly requested as threaded
1186 * interrupts rely on the implicit bh/preempt disable of the hard irq
1187 * context. So we need to disable bh here to avoid deadlocks and other
1188 * side effects.
1189 */
1190static irqreturn_t
1191irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1192{
1193 irqreturn_t ret;
1194
1195 local_bh_disable();
1196 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1197 local_irq_disable();
1198 ret = action->thread_fn(action->irq, action->dev_id);
1199 if (ret == IRQ_HANDLED)
1200 atomic_inc(&desc->threads_handled);
1201
1202 irq_finalize_oneshot(desc, action);
1203 if (!IS_ENABLED(CONFIG_PREEMPT_RT))
1204 local_irq_enable();
1205 local_bh_enable();
1206 return ret;
1207}
1208
1209/*
1210 * Interrupts explicitly requested as threaded interrupts want to be
1211 * preemptible - many of them need to sleep and wait for slow busses to
1212 * complete.
1213 */
1214static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1215 struct irqaction *action)
1216{
1217 irqreturn_t ret;
1218
1219 ret = action->thread_fn(action->irq, action->dev_id);
1220 if (ret == IRQ_HANDLED)
1221 atomic_inc(&desc->threads_handled);
1222
1223 irq_finalize_oneshot(desc, action);
1224 return ret;
1225}
1226
1227void wake_threads_waitq(struct irq_desc *desc)
1228{
1229 if (atomic_dec_and_test(&desc->threads_active))
1230 wake_up(&desc->wait_for_threads);
1231}
1232
1233static void irq_thread_dtor(struct callback_head *unused)
1234{
1235 struct task_struct *tsk = current;
1236 struct irq_desc *desc;
1237 struct irqaction *action;
1238
1239 if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1240 return;
1241
1242 action = kthread_data(tsk);
1243
1244 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1245 tsk->comm, tsk->pid, action->irq);
1246
1247
1248 desc = irq_to_desc(action->irq);
1249 /*
1250 * If IRQTF_RUNTHREAD is set, we need to decrement
1251 * desc->threads_active and wake possible waiters.
1252 */
1253 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1254 wake_threads_waitq(desc);
1255
1256 /* Prevent a stale desc->threads_oneshot */
1257 irq_finalize_oneshot(desc, action);
1258}
1259
1260static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1261{
1262 struct irqaction *secondary = action->secondary;
1263
1264 if (WARN_ON_ONCE(!secondary))
1265 return;
1266
1267 raw_spin_lock_irq(&desc->lock);
1268 __irq_wake_thread(desc, secondary);
1269 raw_spin_unlock_irq(&desc->lock);
1270}
1271
1272/*
1273 * Internal function to notify that a interrupt thread is ready.
1274 */
1275static void irq_thread_set_ready(struct irq_desc *desc,
1276 struct irqaction *action)
1277{
1278 set_bit(IRQTF_READY, &action->thread_flags);
1279 wake_up(&desc->wait_for_threads);
1280}
1281
1282/*
1283 * Internal function to wake up a interrupt thread and wait until it is
1284 * ready.
1285 */
1286static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
1287 struct irqaction *action)
1288{
1289 if (!action || !action->thread)
1290 return;
1291
1292 wake_up_process(action->thread);
1293 wait_event(desc->wait_for_threads,
1294 test_bit(IRQTF_READY, &action->thread_flags));
1295}
1296
1297/*
1298 * Interrupt handler thread
1299 */
1300static int irq_thread(void *data)
1301{
1302 struct callback_head on_exit_work;
1303 struct irqaction *action = data;
1304 struct irq_desc *desc = irq_to_desc(action->irq);
1305 irqreturn_t (*handler_fn)(struct irq_desc *desc,
1306 struct irqaction *action);
1307
1308 irq_thread_set_ready(desc, action);
1309
1310 sched_set_fifo(current);
1311
1312 if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
1313 &action->thread_flags))
1314 handler_fn = irq_forced_thread_fn;
1315 else
1316 handler_fn = irq_thread_fn;
1317
1318 init_task_work(&on_exit_work, irq_thread_dtor);
1319 task_work_add(current, &on_exit_work, TWA_NONE);
1320
1321 while (!irq_wait_for_interrupt(desc, action)) {
1322 irqreturn_t action_ret;
1323
1324 action_ret = handler_fn(desc, action);
1325 if (action_ret == IRQ_WAKE_THREAD)
1326 irq_wake_secondary(desc, action);
1327
1328 wake_threads_waitq(desc);
1329 }
1330
1331 /*
1332 * This is the regular exit path. __free_irq() is stopping the
1333 * thread via kthread_stop() after calling
1334 * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1335 * oneshot mask bit can be set.
1336 */
1337 task_work_cancel_func(current, irq_thread_dtor);
1338 return 0;
1339}
1340
1341/**
1342 * irq_wake_thread - wake the irq thread for the action identified by dev_id
1343 * @irq: Interrupt line
1344 * @dev_id: Device identity for which the thread should be woken
1345 *
1346 */
1347void irq_wake_thread(unsigned int irq, void *dev_id)
1348{
1349 struct irq_desc *desc = irq_to_desc(irq);
1350 struct irqaction *action;
1351 unsigned long flags;
1352
1353 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1354 return;
1355
1356 raw_spin_lock_irqsave(&desc->lock, flags);
1357 for_each_action_of_desc(desc, action) {
1358 if (action->dev_id == dev_id) {
1359 if (action->thread)
1360 __irq_wake_thread(desc, action);
1361 break;
1362 }
1363 }
1364 raw_spin_unlock_irqrestore(&desc->lock, flags);
1365}
1366EXPORT_SYMBOL_GPL(irq_wake_thread);
1367
1368static int irq_setup_forced_threading(struct irqaction *new)
1369{
1370 if (!force_irqthreads())
1371 return 0;
1372 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1373 return 0;
1374
1375 /*
1376 * No further action required for interrupts which are requested as
1377 * threaded interrupts already
1378 */
1379 if (new->handler == irq_default_primary_handler)
1380 return 0;
1381
1382 new->flags |= IRQF_ONESHOT;
1383
1384 /*
1385 * Handle the case where we have a real primary handler and a
1386 * thread handler. We force thread them as well by creating a
1387 * secondary action.
1388 */
1389 if (new->handler && new->thread_fn) {
1390 /* Allocate the secondary action */
1391 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1392 if (!new->secondary)
1393 return -ENOMEM;
1394 new->secondary->handler = irq_forced_secondary_handler;
1395 new->secondary->thread_fn = new->thread_fn;
1396 new->secondary->dev_id = new->dev_id;
1397 new->secondary->irq = new->irq;
1398 new->secondary->name = new->name;
1399 }
1400 /* Deal with the primary handler */
1401 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1402 new->thread_fn = new->handler;
1403 new->handler = irq_default_primary_handler;
1404 return 0;
1405}
1406
1407static int irq_request_resources(struct irq_desc *desc)
1408{
1409 struct irq_data *d = &desc->irq_data;
1410 struct irq_chip *c = d->chip;
1411
1412 return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1413}
1414
1415static void irq_release_resources(struct irq_desc *desc)
1416{
1417 struct irq_data *d = &desc->irq_data;
1418 struct irq_chip *c = d->chip;
1419
1420 if (c->irq_release_resources)
1421 c->irq_release_resources(d);
1422}
1423
1424static bool irq_supports_nmi(struct irq_desc *desc)
1425{
1426 struct irq_data *d = irq_desc_get_irq_data(desc);
1427
1428#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1429 /* Only IRQs directly managed by the root irqchip can be set as NMI */
1430 if (d->parent_data)
1431 return false;
1432#endif
1433 /* Don't support NMIs for chips behind a slow bus */
1434 if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1435 return false;
1436
1437 return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1438}
1439
1440static int irq_nmi_setup(struct irq_desc *desc)
1441{
1442 struct irq_data *d = irq_desc_get_irq_data(desc);
1443 struct irq_chip *c = d->chip;
1444
1445 return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1446}
1447
1448static void irq_nmi_teardown(struct irq_desc *desc)
1449{
1450 struct irq_data *d = irq_desc_get_irq_data(desc);
1451 struct irq_chip *c = d->chip;
1452
1453 if (c->irq_nmi_teardown)
1454 c->irq_nmi_teardown(d);
1455}
1456
1457static int
1458setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1459{
1460 struct task_struct *t;
1461
1462 if (!secondary) {
1463 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1464 new->name);
1465 } else {
1466 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1467 new->name);
1468 }
1469
1470 if (IS_ERR(t))
1471 return PTR_ERR(t);
1472
1473 /*
1474 * We keep the reference to the task struct even if
1475 * the thread dies to avoid that the interrupt code
1476 * references an already freed task_struct.
1477 */
1478 new->thread = get_task_struct(t);
1479 /*
1480 * Tell the thread to set its affinity. This is
1481 * important for shared interrupt handlers as we do
1482 * not invoke setup_affinity() for the secondary
1483 * handlers as everything is already set up. Even for
1484 * interrupts marked with IRQF_NO_BALANCE this is
1485 * correct as we want the thread to move to the cpu(s)
1486 * on which the requesting code placed the interrupt.
1487 */
1488 set_bit(IRQTF_AFFINITY, &new->thread_flags);
1489 return 0;
1490}
1491
1492/*
1493 * Internal function to register an irqaction - typically used to
1494 * allocate special interrupts that are part of the architecture.
1495 *
1496 * Locking rules:
1497 *
1498 * desc->request_mutex Provides serialization against a concurrent free_irq()
1499 * chip_bus_lock Provides serialization for slow bus operations
1500 * desc->lock Provides serialization against hard interrupts
1501 *
1502 * chip_bus_lock and desc->lock are sufficient for all other management and
1503 * interrupt related functions. desc->request_mutex solely serializes
1504 * request/free_irq().
1505 */
1506static int
1507__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1508{
1509 struct irqaction *old, **old_ptr;
1510 unsigned long flags, thread_mask = 0;
1511 int ret, nested, shared = 0;
1512
1513 if (!desc)
1514 return -EINVAL;
1515
1516 if (desc->irq_data.chip == &no_irq_chip)
1517 return -ENOSYS;
1518 if (!try_module_get(desc->owner))
1519 return -ENODEV;
1520
1521 new->irq = irq;
1522
1523 /*
1524 * If the trigger type is not specified by the caller,
1525 * then use the default for this interrupt.
1526 */
1527 if (!(new->flags & IRQF_TRIGGER_MASK))
1528 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1529
1530 /*
1531 * Check whether the interrupt nests into another interrupt
1532 * thread.
1533 */
1534 nested = irq_settings_is_nested_thread(desc);
1535 if (nested) {
1536 if (!new->thread_fn) {
1537 ret = -EINVAL;
1538 goto out_mput;
1539 }
1540 /*
1541 * Replace the primary handler which was provided from
1542 * the driver for non nested interrupt handling by the
1543 * dummy function which warns when called.
1544 */
1545 new->handler = irq_nested_primary_handler;
1546 } else {
1547 if (irq_settings_can_thread(desc)) {
1548 ret = irq_setup_forced_threading(new);
1549 if (ret)
1550 goto out_mput;
1551 }
1552 }
1553
1554 /*
1555 * Create a handler thread when a thread function is supplied
1556 * and the interrupt does not nest into another interrupt
1557 * thread.
1558 */
1559 if (new->thread_fn && !nested) {
1560 ret = setup_irq_thread(new, irq, false);
1561 if (ret)
1562 goto out_mput;
1563 if (new->secondary) {
1564 ret = setup_irq_thread(new->secondary, irq, true);
1565 if (ret)
1566 goto out_thread;
1567 }
1568 }
1569
1570 /*
1571 * Drivers are often written to work w/o knowledge about the
1572 * underlying irq chip implementation, so a request for a
1573 * threaded irq without a primary hard irq context handler
1574 * requires the ONESHOT flag to be set. Some irq chips like
1575 * MSI based interrupts are per se one shot safe. Check the
1576 * chip flags, so we can avoid the unmask dance at the end of
1577 * the threaded handler for those.
1578 */
1579 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1580 new->flags &= ~IRQF_ONESHOT;
1581
1582 /*
1583 * Protects against a concurrent __free_irq() call which might wait
1584 * for synchronize_hardirq() to complete without holding the optional
1585 * chip bus lock and desc->lock. Also protects against handing out
1586 * a recycled oneshot thread_mask bit while it's still in use by
1587 * its previous owner.
1588 */
1589 mutex_lock(&desc->request_mutex);
1590
1591 /*
1592 * Acquire bus lock as the irq_request_resources() callback below
1593 * might rely on the serialization or the magic power management
1594 * functions which are abusing the irq_bus_lock() callback,
1595 */
1596 chip_bus_lock(desc);
1597
1598 /* First installed action requests resources. */
1599 if (!desc->action) {
1600 ret = irq_request_resources(desc);
1601 if (ret) {
1602 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1603 new->name, irq, desc->irq_data.chip->name);
1604 goto out_bus_unlock;
1605 }
1606 }
1607
1608 /*
1609 * The following block of code has to be executed atomically
1610 * protected against a concurrent interrupt and any of the other
1611 * management calls which are not serialized via
1612 * desc->request_mutex or the optional bus lock.
1613 */
1614 raw_spin_lock_irqsave(&desc->lock, flags);
1615 old_ptr = &desc->action;
1616 old = *old_ptr;
1617 if (old) {
1618 /*
1619 * Can't share interrupts unless both agree to and are
1620 * the same type (level, edge, polarity). So both flag
1621 * fields must have IRQF_SHARED set and the bits which
1622 * set the trigger type must match. Also all must
1623 * agree on ONESHOT.
1624 * Interrupt lines used for NMIs cannot be shared.
1625 */
1626 unsigned int oldtype;
1627
1628 if (irq_is_nmi(desc)) {
1629 pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1630 new->name, irq, desc->irq_data.chip->name);
1631 ret = -EINVAL;
1632 goto out_unlock;
1633 }
1634
1635 /*
1636 * If nobody did set the configuration before, inherit
1637 * the one provided by the requester.
1638 */
1639 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1640 oldtype = irqd_get_trigger_type(&desc->irq_data);
1641 } else {
1642 oldtype = new->flags & IRQF_TRIGGER_MASK;
1643 irqd_set_trigger_type(&desc->irq_data, oldtype);
1644 }
1645
1646 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1647 (oldtype != (new->flags & IRQF_TRIGGER_MASK)))
1648 goto mismatch;
1649
1650 if ((old->flags & IRQF_ONESHOT) &&
1651 (new->flags & IRQF_COND_ONESHOT))
1652 new->flags |= IRQF_ONESHOT;
1653 else if ((old->flags ^ new->flags) & IRQF_ONESHOT)
1654 goto mismatch;
1655
1656 /* All handlers must agree on per-cpuness */
1657 if ((old->flags & IRQF_PERCPU) !=
1658 (new->flags & IRQF_PERCPU))
1659 goto mismatch;
1660
1661 /* add new interrupt at end of irq queue */
1662 do {
1663 /*
1664 * Or all existing action->thread_mask bits,
1665 * so we can find the next zero bit for this
1666 * new action.
1667 */
1668 thread_mask |= old->thread_mask;
1669 old_ptr = &old->next;
1670 old = *old_ptr;
1671 } while (old);
1672 shared = 1;
1673 }
1674
1675 /*
1676 * Setup the thread mask for this irqaction for ONESHOT. For
1677 * !ONESHOT irqs the thread mask is 0 so we can avoid a
1678 * conditional in irq_wake_thread().
1679 */
1680 if (new->flags & IRQF_ONESHOT) {
1681 /*
1682 * Unlikely to have 32 resp 64 irqs sharing one line,
1683 * but who knows.
1684 */
1685 if (thread_mask == ~0UL) {
1686 ret = -EBUSY;
1687 goto out_unlock;
1688 }
1689 /*
1690 * The thread_mask for the action is or'ed to
1691 * desc->thread_active to indicate that the
1692 * IRQF_ONESHOT thread handler has been woken, but not
1693 * yet finished. The bit is cleared when a thread
1694 * completes. When all threads of a shared interrupt
1695 * line have completed desc->threads_active becomes
1696 * zero and the interrupt line is unmasked. See
1697 * handle.c:irq_wake_thread() for further information.
1698 *
1699 * If no thread is woken by primary (hard irq context)
1700 * interrupt handlers, then desc->threads_active is
1701 * also checked for zero to unmask the irq line in the
1702 * affected hard irq flow handlers
1703 * (handle_[fasteoi|level]_irq).
1704 *
1705 * The new action gets the first zero bit of
1706 * thread_mask assigned. See the loop above which or's
1707 * all existing action->thread_mask bits.
1708 */
1709 new->thread_mask = 1UL << ffz(thread_mask);
1710
1711 } else if (new->handler == irq_default_primary_handler &&
1712 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1713 /*
1714 * The interrupt was requested with handler = NULL, so
1715 * we use the default primary handler for it. But it
1716 * does not have the oneshot flag set. In combination
1717 * with level interrupts this is deadly, because the
1718 * default primary handler just wakes the thread, then
1719 * the irq lines is reenabled, but the device still
1720 * has the level irq asserted. Rinse and repeat....
1721 *
1722 * While this works for edge type interrupts, we play
1723 * it safe and reject unconditionally because we can't
1724 * say for sure which type this interrupt really
1725 * has. The type flags are unreliable as the
1726 * underlying chip implementation can override them.
1727 */
1728 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1729 new->name, irq);
1730 ret = -EINVAL;
1731 goto out_unlock;
1732 }
1733
1734 if (!shared) {
1735 /* Setup the type (level, edge polarity) if configured: */
1736 if (new->flags & IRQF_TRIGGER_MASK) {
1737 ret = __irq_set_trigger(desc,
1738 new->flags & IRQF_TRIGGER_MASK);
1739
1740 if (ret)
1741 goto out_unlock;
1742 }
1743
1744 /*
1745 * Activate the interrupt. That activation must happen
1746 * independently of IRQ_NOAUTOEN. request_irq() can fail
1747 * and the callers are supposed to handle
1748 * that. enable_irq() of an interrupt requested with
1749 * IRQ_NOAUTOEN is not supposed to fail. The activation
1750 * keeps it in shutdown mode, it merily associates
1751 * resources if necessary and if that's not possible it
1752 * fails. Interrupts which are in managed shutdown mode
1753 * will simply ignore that activation request.
1754 */
1755 ret = irq_activate(desc);
1756 if (ret)
1757 goto out_unlock;
1758
1759 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1760 IRQS_ONESHOT | IRQS_WAITING);
1761 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1762
1763 if (new->flags & IRQF_PERCPU) {
1764 irqd_set(&desc->irq_data, IRQD_PER_CPU);
1765 irq_settings_set_per_cpu(desc);
1766 if (new->flags & IRQF_NO_DEBUG)
1767 irq_settings_set_no_debug(desc);
1768 }
1769
1770 if (noirqdebug)
1771 irq_settings_set_no_debug(desc);
1772
1773 if (new->flags & IRQF_ONESHOT)
1774 desc->istate |= IRQS_ONESHOT;
1775
1776 /* Exclude IRQ from balancing if requested */
1777 if (new->flags & IRQF_NOBALANCING) {
1778 irq_settings_set_no_balancing(desc);
1779 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1780 }
1781
1782 if (!(new->flags & IRQF_NO_AUTOEN) &&
1783 irq_settings_can_autoenable(desc)) {
1784 irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1785 } else {
1786 /*
1787 * Shared interrupts do not go well with disabling
1788 * auto enable. The sharing interrupt might request
1789 * it while it's still disabled and then wait for
1790 * interrupts forever.
1791 */
1792 WARN_ON_ONCE(new->flags & IRQF_SHARED);
1793 /* Undo nested disables: */
1794 desc->depth = 1;
1795 }
1796
1797 } else if (new->flags & IRQF_TRIGGER_MASK) {
1798 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1799 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1800
1801 if (nmsk != omsk)
1802 /* hope the handler works with current trigger mode */
1803 pr_warn("irq %d uses trigger mode %u; requested %u\n",
1804 irq, omsk, nmsk);
1805 }
1806
1807 *old_ptr = new;
1808
1809 irq_pm_install_action(desc, new);
1810
1811 /* Reset broken irq detection when installing new handler */
1812 desc->irq_count = 0;
1813 desc->irqs_unhandled = 0;
1814
1815 /*
1816 * Check whether we disabled the irq via the spurious handler
1817 * before. Reenable it and give it another chance.
1818 */
1819 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1820 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1821 __enable_irq(desc);
1822 }
1823
1824 raw_spin_unlock_irqrestore(&desc->lock, flags);
1825 chip_bus_sync_unlock(desc);
1826 mutex_unlock(&desc->request_mutex);
1827
1828 irq_setup_timings(desc, new);
1829
1830 wake_up_and_wait_for_irq_thread_ready(desc, new);
1831 wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
1832
1833 register_irq_proc(irq, desc);
1834 new->dir = NULL;
1835 register_handler_proc(irq, new);
1836 return 0;
1837
1838mismatch:
1839 if (!(new->flags & IRQF_PROBE_SHARED)) {
1840 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1841 irq, new->flags, new->name, old->flags, old->name);
1842#ifdef CONFIG_DEBUG_SHIRQ
1843 dump_stack();
1844#endif
1845 }
1846 ret = -EBUSY;
1847
1848out_unlock:
1849 raw_spin_unlock_irqrestore(&desc->lock, flags);
1850
1851 if (!desc->action)
1852 irq_release_resources(desc);
1853out_bus_unlock:
1854 chip_bus_sync_unlock(desc);
1855 mutex_unlock(&desc->request_mutex);
1856
1857out_thread:
1858 if (new->thread) {
1859 struct task_struct *t = new->thread;
1860
1861 new->thread = NULL;
1862 kthread_stop_put(t);
1863 }
1864 if (new->secondary && new->secondary->thread) {
1865 struct task_struct *t = new->secondary->thread;
1866
1867 new->secondary->thread = NULL;
1868 kthread_stop_put(t);
1869 }
1870out_mput:
1871 module_put(desc->owner);
1872 return ret;
1873}
1874
1875/*
1876 * Internal function to unregister an irqaction - used to free
1877 * regular and special interrupts that are part of the architecture.
1878 */
1879static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1880{
1881 unsigned irq = desc->irq_data.irq;
1882 struct irqaction *action, **action_ptr;
1883 unsigned long flags;
1884
1885 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1886
1887 mutex_lock(&desc->request_mutex);
1888 chip_bus_lock(desc);
1889 raw_spin_lock_irqsave(&desc->lock, flags);
1890
1891 /*
1892 * There can be multiple actions per IRQ descriptor, find the right
1893 * one based on the dev_id:
1894 */
1895 action_ptr = &desc->action;
1896 for (;;) {
1897 action = *action_ptr;
1898
1899 if (!action) {
1900 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1901 raw_spin_unlock_irqrestore(&desc->lock, flags);
1902 chip_bus_sync_unlock(desc);
1903 mutex_unlock(&desc->request_mutex);
1904 return NULL;
1905 }
1906
1907 if (action->dev_id == dev_id)
1908 break;
1909 action_ptr = &action->next;
1910 }
1911
1912 /* Found it - now remove it from the list of entries: */
1913 *action_ptr = action->next;
1914
1915 irq_pm_remove_action(desc, action);
1916
1917 /* If this was the last handler, shut down the IRQ line: */
1918 if (!desc->action) {
1919 irq_settings_clr_disable_unlazy(desc);
1920 /* Only shutdown. Deactivate after synchronize_hardirq() */
1921 irq_shutdown(desc);
1922 }
1923
1924#ifdef CONFIG_SMP
1925 /* make sure affinity_hint is cleaned up */
1926 if (WARN_ON_ONCE(desc->affinity_hint))
1927 desc->affinity_hint = NULL;
1928#endif
1929
1930 raw_spin_unlock_irqrestore(&desc->lock, flags);
1931 /*
1932 * Drop bus_lock here so the changes which were done in the chip
1933 * callbacks above are synced out to the irq chips which hang
1934 * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1935 *
1936 * Aside of that the bus_lock can also be taken from the threaded
1937 * handler in irq_finalize_oneshot() which results in a deadlock
1938 * because kthread_stop() would wait forever for the thread to
1939 * complete, which is blocked on the bus lock.
1940 *
1941 * The still held desc->request_mutex() protects against a
1942 * concurrent request_irq() of this irq so the release of resources
1943 * and timing data is properly serialized.
1944 */
1945 chip_bus_sync_unlock(desc);
1946
1947 unregister_handler_proc(irq, action);
1948
1949 /*
1950 * Make sure it's not being used on another CPU and if the chip
1951 * supports it also make sure that there is no (not yet serviced)
1952 * interrupt in flight at the hardware level.
1953 */
1954 __synchronize_irq(desc);
1955
1956#ifdef CONFIG_DEBUG_SHIRQ
1957 /*
1958 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1959 * event to happen even now it's being freed, so let's make sure that
1960 * is so by doing an extra call to the handler ....
1961 *
1962 * ( We do this after actually deregistering it, to make sure that a
1963 * 'real' IRQ doesn't run in parallel with our fake. )
1964 */
1965 if (action->flags & IRQF_SHARED) {
1966 local_irq_save(flags);
1967 action->handler(irq, dev_id);
1968 local_irq_restore(flags);
1969 }
1970#endif
1971
1972 /*
1973 * The action has already been removed above, but the thread writes
1974 * its oneshot mask bit when it completes. Though request_mutex is
1975 * held across this which prevents __setup_irq() from handing out
1976 * the same bit to a newly requested action.
1977 */
1978 if (action->thread) {
1979 kthread_stop_put(action->thread);
1980 if (action->secondary && action->secondary->thread)
1981 kthread_stop_put(action->secondary->thread);
1982 }
1983
1984 /* Last action releases resources */
1985 if (!desc->action) {
1986 /*
1987 * Reacquire bus lock as irq_release_resources() might
1988 * require it to deallocate resources over the slow bus.
1989 */
1990 chip_bus_lock(desc);
1991 /*
1992 * There is no interrupt on the fly anymore. Deactivate it
1993 * completely.
1994 */
1995 raw_spin_lock_irqsave(&desc->lock, flags);
1996 irq_domain_deactivate_irq(&desc->irq_data);
1997 raw_spin_unlock_irqrestore(&desc->lock, flags);
1998
1999 irq_release_resources(desc);
2000 chip_bus_sync_unlock(desc);
2001 irq_remove_timings(desc);
2002 }
2003
2004 mutex_unlock(&desc->request_mutex);
2005
2006 irq_chip_pm_put(&desc->irq_data);
2007 module_put(desc->owner);
2008 kfree(action->secondary);
2009 return action;
2010}
2011
2012/**
2013 * free_irq - free an interrupt allocated with request_irq
2014 * @irq: Interrupt line to free
2015 * @dev_id: Device identity to free
2016 *
2017 * Remove an interrupt handler. The handler is removed and if the
2018 * interrupt line is no longer in use by any driver it is disabled.
2019 * On a shared IRQ the caller must ensure the interrupt is disabled
2020 * on the card it drives before calling this function. The function
2021 * does not return until any executing interrupts for this IRQ
2022 * have completed.
2023 *
2024 * This function must not be called from interrupt context.
2025 *
2026 * Returns the devname argument passed to request_irq.
2027 */
2028const void *free_irq(unsigned int irq, void *dev_id)
2029{
2030 struct irq_desc *desc = irq_to_desc(irq);
2031 struct irqaction *action;
2032 const char *devname;
2033
2034 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2035 return NULL;
2036
2037#ifdef CONFIG_SMP
2038 if (WARN_ON(desc->affinity_notify))
2039 desc->affinity_notify = NULL;
2040#endif
2041
2042 action = __free_irq(desc, dev_id);
2043
2044 if (!action)
2045 return NULL;
2046
2047 devname = action->name;
2048 kfree(action);
2049 return devname;
2050}
2051EXPORT_SYMBOL(free_irq);
2052
2053/* This function must be called with desc->lock held */
2054static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
2055{
2056 const char *devname = NULL;
2057
2058 desc->istate &= ~IRQS_NMI;
2059
2060 if (!WARN_ON(desc->action == NULL)) {
2061 irq_pm_remove_action(desc, desc->action);
2062 devname = desc->action->name;
2063 unregister_handler_proc(irq, desc->action);
2064
2065 kfree(desc->action);
2066 desc->action = NULL;
2067 }
2068
2069 irq_settings_clr_disable_unlazy(desc);
2070 irq_shutdown_and_deactivate(desc);
2071
2072 irq_release_resources(desc);
2073
2074 irq_chip_pm_put(&desc->irq_data);
2075 module_put(desc->owner);
2076
2077 return devname;
2078}
2079
2080const void *free_nmi(unsigned int irq, void *dev_id)
2081{
2082 struct irq_desc *desc = irq_to_desc(irq);
2083 unsigned long flags;
2084 const void *devname;
2085
2086 if (!desc || WARN_ON(!irq_is_nmi(desc)))
2087 return NULL;
2088
2089 if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2090 return NULL;
2091
2092 /* NMI still enabled */
2093 if (WARN_ON(desc->depth == 0))
2094 disable_nmi_nosync(irq);
2095
2096 raw_spin_lock_irqsave(&desc->lock, flags);
2097
2098 irq_nmi_teardown(desc);
2099 devname = __cleanup_nmi(irq, desc);
2100
2101 raw_spin_unlock_irqrestore(&desc->lock, flags);
2102
2103 return devname;
2104}
2105
2106/**
2107 * request_threaded_irq - allocate an interrupt line
2108 * @irq: Interrupt line to allocate
2109 * @handler: Function to be called when the IRQ occurs.
2110 * Primary handler for threaded interrupts.
2111 * If handler is NULL and thread_fn != NULL
2112 * the default primary handler is installed.
2113 * @thread_fn: Function called from the irq handler thread
2114 * If NULL, no irq thread is created
2115 * @irqflags: Interrupt type flags
2116 * @devname: An ascii name for the claiming device
2117 * @dev_id: A cookie passed back to the handler function
2118 *
2119 * This call allocates interrupt resources and enables the
2120 * interrupt line and IRQ handling. From the point this
2121 * call is made your handler function may be invoked. Since
2122 * your handler function must clear any interrupt the board
2123 * raises, you must take care both to initialise your hardware
2124 * and to set up the interrupt handler in the right order.
2125 *
2126 * If you want to set up a threaded irq handler for your device
2127 * then you need to supply @handler and @thread_fn. @handler is
2128 * still called in hard interrupt context and has to check
2129 * whether the interrupt originates from the device. If yes it
2130 * needs to disable the interrupt on the device and return
2131 * IRQ_WAKE_THREAD which will wake up the handler thread and run
2132 * @thread_fn. This split handler design is necessary to support
2133 * shared interrupts.
2134 *
2135 * Dev_id must be globally unique. Normally the address of the
2136 * device data structure is used as the cookie. Since the handler
2137 * receives this value it makes sense to use it.
2138 *
2139 * If your interrupt is shared you must pass a non NULL dev_id
2140 * as this is required when freeing the interrupt.
2141 *
2142 * Flags:
2143 *
2144 * IRQF_SHARED Interrupt is shared
2145 * IRQF_TRIGGER_* Specify active edge(s) or level
2146 * IRQF_ONESHOT Run thread_fn with interrupt line masked
2147 */
2148int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2149 irq_handler_t thread_fn, unsigned long irqflags,
2150 const char *devname, void *dev_id)
2151{
2152 struct irqaction *action;
2153 struct irq_desc *desc;
2154 int retval;
2155
2156 if (irq == IRQ_NOTCONNECTED)
2157 return -ENOTCONN;
2158
2159 /*
2160 * Sanity-check: shared interrupts must pass in a real dev-ID,
2161 * otherwise we'll have trouble later trying to figure out
2162 * which interrupt is which (messes up the interrupt freeing
2163 * logic etc).
2164 *
2165 * Also shared interrupts do not go well with disabling auto enable.
2166 * The sharing interrupt might request it while it's still disabled
2167 * and then wait for interrupts forever.
2168 *
2169 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2170 * it cannot be set along with IRQF_NO_SUSPEND.
2171 */
2172 if (((irqflags & IRQF_SHARED) && !dev_id) ||
2173 ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) ||
2174 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2175 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2176 return -EINVAL;
2177
2178 desc = irq_to_desc(irq);
2179 if (!desc)
2180 return -EINVAL;
2181
2182 if (!irq_settings_can_request(desc) ||
2183 WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2184 return -EINVAL;
2185
2186 if (!handler) {
2187 if (!thread_fn)
2188 return -EINVAL;
2189 handler = irq_default_primary_handler;
2190 }
2191
2192 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2193 if (!action)
2194 return -ENOMEM;
2195
2196 action->handler = handler;
2197 action->thread_fn = thread_fn;
2198 action->flags = irqflags;
2199 action->name = devname;
2200 action->dev_id = dev_id;
2201
2202 retval = irq_chip_pm_get(&desc->irq_data);
2203 if (retval < 0) {
2204 kfree(action);
2205 return retval;
2206 }
2207
2208 retval = __setup_irq(irq, desc, action);
2209
2210 if (retval) {
2211 irq_chip_pm_put(&desc->irq_data);
2212 kfree(action->secondary);
2213 kfree(action);
2214 }
2215
2216#ifdef CONFIG_DEBUG_SHIRQ_FIXME
2217 if (!retval && (irqflags & IRQF_SHARED)) {
2218 /*
2219 * It's a shared IRQ -- the driver ought to be prepared for it
2220 * to happen immediately, so let's make sure....
2221 * We disable the irq to make sure that a 'real' IRQ doesn't
2222 * run in parallel with our fake.
2223 */
2224 unsigned long flags;
2225
2226 disable_irq(irq);
2227 local_irq_save(flags);
2228
2229 handler(irq, dev_id);
2230
2231 local_irq_restore(flags);
2232 enable_irq(irq);
2233 }
2234#endif
2235 return retval;
2236}
2237EXPORT_SYMBOL(request_threaded_irq);
2238
2239/**
2240 * request_any_context_irq - allocate an interrupt line
2241 * @irq: Interrupt line to allocate
2242 * @handler: Function to be called when the IRQ occurs.
2243 * Threaded handler for threaded interrupts.
2244 * @flags: Interrupt type flags
2245 * @name: An ascii name for the claiming device
2246 * @dev_id: A cookie passed back to the handler function
2247 *
2248 * This call allocates interrupt resources and enables the
2249 * interrupt line and IRQ handling. It selects either a
2250 * hardirq or threaded handling method depending on the
2251 * context.
2252 *
2253 * On failure, it returns a negative value. On success,
2254 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2255 */
2256int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2257 unsigned long flags, const char *name, void *dev_id)
2258{
2259 struct irq_desc *desc;
2260 int ret;
2261
2262 if (irq == IRQ_NOTCONNECTED)
2263 return -ENOTCONN;
2264
2265 desc = irq_to_desc(irq);
2266 if (!desc)
2267 return -EINVAL;
2268
2269 if (irq_settings_is_nested_thread(desc)) {
2270 ret = request_threaded_irq(irq, NULL, handler,
2271 flags, name, dev_id);
2272 return !ret ? IRQC_IS_NESTED : ret;
2273 }
2274
2275 ret = request_irq(irq, handler, flags, name, dev_id);
2276 return !ret ? IRQC_IS_HARDIRQ : ret;
2277}
2278EXPORT_SYMBOL_GPL(request_any_context_irq);
2279
2280/**
2281 * request_nmi - allocate an interrupt line for NMI delivery
2282 * @irq: Interrupt line to allocate
2283 * @handler: Function to be called when the IRQ occurs.
2284 * Threaded handler for threaded interrupts.
2285 * @irqflags: Interrupt type flags
2286 * @name: An ascii name for the claiming device
2287 * @dev_id: A cookie passed back to the handler function
2288 *
2289 * This call allocates interrupt resources and enables the
2290 * interrupt line and IRQ handling. It sets up the IRQ line
2291 * to be handled as an NMI.
2292 *
2293 * An interrupt line delivering NMIs cannot be shared and IRQ handling
2294 * cannot be threaded.
2295 *
2296 * Interrupt lines requested for NMI delivering must produce per cpu
2297 * interrupts and have auto enabling setting disabled.
2298 *
2299 * Dev_id must be globally unique. Normally the address of the
2300 * device data structure is used as the cookie. Since the handler
2301 * receives this value it makes sense to use it.
2302 *
2303 * If the interrupt line cannot be used to deliver NMIs, function
2304 * will fail and return a negative value.
2305 */
2306int request_nmi(unsigned int irq, irq_handler_t handler,
2307 unsigned long irqflags, const char *name, void *dev_id)
2308{
2309 struct irqaction *action;
2310 struct irq_desc *desc;
2311 unsigned long flags;
2312 int retval;
2313
2314 if (irq == IRQ_NOTCONNECTED)
2315 return -ENOTCONN;
2316
2317 /* NMI cannot be shared, used for Polling */
2318 if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2319 return -EINVAL;
2320
2321 if (!(irqflags & IRQF_PERCPU))
2322 return -EINVAL;
2323
2324 if (!handler)
2325 return -EINVAL;
2326
2327 desc = irq_to_desc(irq);
2328
2329 if (!desc || (irq_settings_can_autoenable(desc) &&
2330 !(irqflags & IRQF_NO_AUTOEN)) ||
2331 !irq_settings_can_request(desc) ||
2332 WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2333 !irq_supports_nmi(desc))
2334 return -EINVAL;
2335
2336 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2337 if (!action)
2338 return -ENOMEM;
2339
2340 action->handler = handler;
2341 action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2342 action->name = name;
2343 action->dev_id = dev_id;
2344
2345 retval = irq_chip_pm_get(&desc->irq_data);
2346 if (retval < 0)
2347 goto err_out;
2348
2349 retval = __setup_irq(irq, desc, action);
2350 if (retval)
2351 goto err_irq_setup;
2352
2353 raw_spin_lock_irqsave(&desc->lock, flags);
2354
2355 /* Setup NMI state */
2356 desc->istate |= IRQS_NMI;
2357 retval = irq_nmi_setup(desc);
2358 if (retval) {
2359 __cleanup_nmi(irq, desc);
2360 raw_spin_unlock_irqrestore(&desc->lock, flags);
2361 return -EINVAL;
2362 }
2363
2364 raw_spin_unlock_irqrestore(&desc->lock, flags);
2365
2366 return 0;
2367
2368err_irq_setup:
2369 irq_chip_pm_put(&desc->irq_data);
2370err_out:
2371 kfree(action);
2372
2373 return retval;
2374}
2375
2376void enable_percpu_irq(unsigned int irq, unsigned int type)
2377{
2378 unsigned int cpu = smp_processor_id();
2379 unsigned long flags;
2380 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2381
2382 if (!desc)
2383 return;
2384
2385 /*
2386 * If the trigger type is not specified by the caller, then
2387 * use the default for this interrupt.
2388 */
2389 type &= IRQ_TYPE_SENSE_MASK;
2390 if (type == IRQ_TYPE_NONE)
2391 type = irqd_get_trigger_type(&desc->irq_data);
2392
2393 if (type != IRQ_TYPE_NONE) {
2394 int ret;
2395
2396 ret = __irq_set_trigger(desc, type);
2397
2398 if (ret) {
2399 WARN(1, "failed to set type for IRQ%d\n", irq);
2400 goto out;
2401 }
2402 }
2403
2404 irq_percpu_enable(desc, cpu);
2405out:
2406 irq_put_desc_unlock(desc, flags);
2407}
2408EXPORT_SYMBOL_GPL(enable_percpu_irq);
2409
2410void enable_percpu_nmi(unsigned int irq, unsigned int type)
2411{
2412 enable_percpu_irq(irq, type);
2413}
2414
2415/**
2416 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2417 * @irq: Linux irq number to check for
2418 *
2419 * Must be called from a non migratable context. Returns the enable
2420 * state of a per cpu interrupt on the current cpu.
2421 */
2422bool irq_percpu_is_enabled(unsigned int irq)
2423{
2424 unsigned int cpu = smp_processor_id();
2425 struct irq_desc *desc;
2426 unsigned long flags;
2427 bool is_enabled;
2428
2429 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2430 if (!desc)
2431 return false;
2432
2433 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2434 irq_put_desc_unlock(desc, flags);
2435
2436 return is_enabled;
2437}
2438EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2439
2440void disable_percpu_irq(unsigned int irq)
2441{
2442 unsigned int cpu = smp_processor_id();
2443 unsigned long flags;
2444 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2445
2446 if (!desc)
2447 return;
2448
2449 irq_percpu_disable(desc, cpu);
2450 irq_put_desc_unlock(desc, flags);
2451}
2452EXPORT_SYMBOL_GPL(disable_percpu_irq);
2453
2454void disable_percpu_nmi(unsigned int irq)
2455{
2456 disable_percpu_irq(irq);
2457}
2458
2459/*
2460 * Internal function to unregister a percpu irqaction.
2461 */
2462static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2463{
2464 struct irq_desc *desc = irq_to_desc(irq);
2465 struct irqaction *action;
2466 unsigned long flags;
2467
2468 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2469
2470 if (!desc)
2471 return NULL;
2472
2473 raw_spin_lock_irqsave(&desc->lock, flags);
2474
2475 action = desc->action;
2476 if (!action || action->percpu_dev_id != dev_id) {
2477 WARN(1, "Trying to free already-free IRQ %d\n", irq);
2478 goto bad;
2479 }
2480
2481 if (!cpumask_empty(desc->percpu_enabled)) {
2482 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2483 irq, cpumask_first(desc->percpu_enabled));
2484 goto bad;
2485 }
2486
2487 /* Found it - now remove it from the list of entries: */
2488 desc->action = NULL;
2489
2490 desc->istate &= ~IRQS_NMI;
2491
2492 raw_spin_unlock_irqrestore(&desc->lock, flags);
2493
2494 unregister_handler_proc(irq, action);
2495
2496 irq_chip_pm_put(&desc->irq_data);
2497 module_put(desc->owner);
2498 return action;
2499
2500bad:
2501 raw_spin_unlock_irqrestore(&desc->lock, flags);
2502 return NULL;
2503}
2504
2505/**
2506 * remove_percpu_irq - free a per-cpu interrupt
2507 * @irq: Interrupt line to free
2508 * @act: irqaction for the interrupt
2509 *
2510 * Used to remove interrupts statically setup by the early boot process.
2511 */
2512void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2513{
2514 struct irq_desc *desc = irq_to_desc(irq);
2515
2516 if (desc && irq_settings_is_per_cpu_devid(desc))
2517 __free_percpu_irq(irq, act->percpu_dev_id);
2518}
2519
2520/**
2521 * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2522 * @irq: Interrupt line to free
2523 * @dev_id: Device identity to free
2524 *
2525 * Remove a percpu interrupt handler. The handler is removed, but
2526 * the interrupt line is not disabled. This must be done on each
2527 * CPU before calling this function. The function does not return
2528 * until any executing interrupts for this IRQ have completed.
2529 *
2530 * This function must not be called from interrupt context.
2531 */
2532void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2533{
2534 struct irq_desc *desc = irq_to_desc(irq);
2535
2536 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2537 return;
2538
2539 chip_bus_lock(desc);
2540 kfree(__free_percpu_irq(irq, dev_id));
2541 chip_bus_sync_unlock(desc);
2542}
2543EXPORT_SYMBOL_GPL(free_percpu_irq);
2544
2545void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2546{
2547 struct irq_desc *desc = irq_to_desc(irq);
2548
2549 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2550 return;
2551
2552 if (WARN_ON(!irq_is_nmi(desc)))
2553 return;
2554
2555 kfree(__free_percpu_irq(irq, dev_id));
2556}
2557
2558/**
2559 * setup_percpu_irq - setup a per-cpu interrupt
2560 * @irq: Interrupt line to setup
2561 * @act: irqaction for the interrupt
2562 *
2563 * Used to statically setup per-cpu interrupts in the early boot process.
2564 */
2565int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2566{
2567 struct irq_desc *desc = irq_to_desc(irq);
2568 int retval;
2569
2570 if (!desc || !irq_settings_is_per_cpu_devid(desc))
2571 return -EINVAL;
2572
2573 retval = irq_chip_pm_get(&desc->irq_data);
2574 if (retval < 0)
2575 return retval;
2576
2577 retval = __setup_irq(irq, desc, act);
2578
2579 if (retval)
2580 irq_chip_pm_put(&desc->irq_data);
2581
2582 return retval;
2583}
2584
2585/**
2586 * __request_percpu_irq - allocate a percpu interrupt line
2587 * @irq: Interrupt line to allocate
2588 * @handler: Function to be called when the IRQ occurs.
2589 * @flags: Interrupt type flags (IRQF_TIMER only)
2590 * @devname: An ascii name for the claiming device
2591 * @dev_id: A percpu cookie passed back to the handler function
2592 *
2593 * This call allocates interrupt resources and enables the
2594 * interrupt on the local CPU. If the interrupt is supposed to be
2595 * enabled on other CPUs, it has to be done on each CPU using
2596 * enable_percpu_irq().
2597 *
2598 * Dev_id must be globally unique. It is a per-cpu variable, and
2599 * the handler gets called with the interrupted CPU's instance of
2600 * that variable.
2601 */
2602int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2603 unsigned long flags, const char *devname,
2604 void __percpu *dev_id)
2605{
2606 struct irqaction *action;
2607 struct irq_desc *desc;
2608 int retval;
2609
2610 if (!dev_id)
2611 return -EINVAL;
2612
2613 desc = irq_to_desc(irq);
2614 if (!desc || !irq_settings_can_request(desc) ||
2615 !irq_settings_is_per_cpu_devid(desc))
2616 return -EINVAL;
2617
2618 if (flags && flags != IRQF_TIMER)
2619 return -EINVAL;
2620
2621 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2622 if (!action)
2623 return -ENOMEM;
2624
2625 action->handler = handler;
2626 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2627 action->name = devname;
2628 action->percpu_dev_id = dev_id;
2629
2630 retval = irq_chip_pm_get(&desc->irq_data);
2631 if (retval < 0) {
2632 kfree(action);
2633 return retval;
2634 }
2635
2636 retval = __setup_irq(irq, desc, action);
2637
2638 if (retval) {
2639 irq_chip_pm_put(&desc->irq_data);
2640 kfree(action);
2641 }
2642
2643 return retval;
2644}
2645EXPORT_SYMBOL_GPL(__request_percpu_irq);
2646
2647/**
2648 * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2649 * @irq: Interrupt line to allocate
2650 * @handler: Function to be called when the IRQ occurs.
2651 * @name: An ascii name for the claiming device
2652 * @dev_id: A percpu cookie passed back to the handler function
2653 *
2654 * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2655 * have to be setup on each CPU by calling prepare_percpu_nmi() before
2656 * being enabled on the same CPU by using enable_percpu_nmi().
2657 *
2658 * Dev_id must be globally unique. It is a per-cpu variable, and
2659 * the handler gets called with the interrupted CPU's instance of
2660 * that variable.
2661 *
2662 * Interrupt lines requested for NMI delivering should have auto enabling
2663 * setting disabled.
2664 *
2665 * If the interrupt line cannot be used to deliver NMIs, function
2666 * will fail returning a negative value.
2667 */
2668int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2669 const char *name, void __percpu *dev_id)
2670{
2671 struct irqaction *action;
2672 struct irq_desc *desc;
2673 unsigned long flags;
2674 int retval;
2675
2676 if (!handler)
2677 return -EINVAL;
2678
2679 desc = irq_to_desc(irq);
2680
2681 if (!desc || !irq_settings_can_request(desc) ||
2682 !irq_settings_is_per_cpu_devid(desc) ||
2683 irq_settings_can_autoenable(desc) ||
2684 !irq_supports_nmi(desc))
2685 return -EINVAL;
2686
2687 /* The line cannot already be NMI */
2688 if (irq_is_nmi(desc))
2689 return -EINVAL;
2690
2691 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2692 if (!action)
2693 return -ENOMEM;
2694
2695 action->handler = handler;
2696 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2697 | IRQF_NOBALANCING;
2698 action->name = name;
2699 action->percpu_dev_id = dev_id;
2700
2701 retval = irq_chip_pm_get(&desc->irq_data);
2702 if (retval < 0)
2703 goto err_out;
2704
2705 retval = __setup_irq(irq, desc, action);
2706 if (retval)
2707 goto err_irq_setup;
2708
2709 raw_spin_lock_irqsave(&desc->lock, flags);
2710 desc->istate |= IRQS_NMI;
2711 raw_spin_unlock_irqrestore(&desc->lock, flags);
2712
2713 return 0;
2714
2715err_irq_setup:
2716 irq_chip_pm_put(&desc->irq_data);
2717err_out:
2718 kfree(action);
2719
2720 return retval;
2721}
2722
2723/**
2724 * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2725 * @irq: Interrupt line to prepare for NMI delivery
2726 *
2727 * This call prepares an interrupt line to deliver NMI on the current CPU,
2728 * before that interrupt line gets enabled with enable_percpu_nmi().
2729 *
2730 * As a CPU local operation, this should be called from non-preemptible
2731 * context.
2732 *
2733 * If the interrupt line cannot be used to deliver NMIs, function
2734 * will fail returning a negative value.
2735 */
2736int prepare_percpu_nmi(unsigned int irq)
2737{
2738 unsigned long flags;
2739 struct irq_desc *desc;
2740 int ret = 0;
2741
2742 WARN_ON(preemptible());
2743
2744 desc = irq_get_desc_lock(irq, &flags,
2745 IRQ_GET_DESC_CHECK_PERCPU);
2746 if (!desc)
2747 return -EINVAL;
2748
2749 if (WARN(!irq_is_nmi(desc),
2750 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2751 irq)) {
2752 ret = -EINVAL;
2753 goto out;
2754 }
2755
2756 ret = irq_nmi_setup(desc);
2757 if (ret) {
2758 pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2759 goto out;
2760 }
2761
2762out:
2763 irq_put_desc_unlock(desc, flags);
2764 return ret;
2765}
2766
2767/**
2768 * teardown_percpu_nmi - undoes NMI setup of IRQ line
2769 * @irq: Interrupt line from which CPU local NMI configuration should be
2770 * removed
2771 *
2772 * This call undoes the setup done by prepare_percpu_nmi().
2773 *
2774 * IRQ line should not be enabled for the current CPU.
2775 *
2776 * As a CPU local operation, this should be called from non-preemptible
2777 * context.
2778 */
2779void teardown_percpu_nmi(unsigned int irq)
2780{
2781 unsigned long flags;
2782 struct irq_desc *desc;
2783
2784 WARN_ON(preemptible());
2785
2786 desc = irq_get_desc_lock(irq, &flags,
2787 IRQ_GET_DESC_CHECK_PERCPU);
2788 if (!desc)
2789 return;
2790
2791 if (WARN_ON(!irq_is_nmi(desc)))
2792 goto out;
2793
2794 irq_nmi_teardown(desc);
2795out:
2796 irq_put_desc_unlock(desc, flags);
2797}
2798
2799int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2800 bool *state)
2801{
2802 struct irq_chip *chip;
2803 int err = -EINVAL;
2804
2805 do {
2806 chip = irq_data_get_irq_chip(data);
2807 if (WARN_ON_ONCE(!chip))
2808 return -ENODEV;
2809 if (chip->irq_get_irqchip_state)
2810 break;
2811#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2812 data = data->parent_data;
2813#else
2814 data = NULL;
2815#endif
2816 } while (data);
2817
2818 if (data)
2819 err = chip->irq_get_irqchip_state(data, which, state);
2820 return err;
2821}
2822
2823/**
2824 * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2825 * @irq: Interrupt line that is forwarded to a VM
2826 * @which: One of IRQCHIP_STATE_* the caller wants to know about
2827 * @state: a pointer to a boolean where the state is to be stored
2828 *
2829 * This call snapshots the internal irqchip state of an
2830 * interrupt, returning into @state the bit corresponding to
2831 * stage @which
2832 *
2833 * This function should be called with preemption disabled if the
2834 * interrupt controller has per-cpu registers.
2835 */
2836int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2837 bool *state)
2838{
2839 struct irq_desc *desc;
2840 struct irq_data *data;
2841 unsigned long flags;
2842 int err = -EINVAL;
2843
2844 desc = irq_get_desc_buslock(irq, &flags, 0);
2845 if (!desc)
2846 return err;
2847
2848 data = irq_desc_get_irq_data(desc);
2849
2850 err = __irq_get_irqchip_state(data, which, state);
2851
2852 irq_put_desc_busunlock(desc, flags);
2853 return err;
2854}
2855EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2856
2857/**
2858 * irq_set_irqchip_state - set the state of a forwarded interrupt.
2859 * @irq: Interrupt line that is forwarded to a VM
2860 * @which: State to be restored (one of IRQCHIP_STATE_*)
2861 * @val: Value corresponding to @which
2862 *
2863 * This call sets the internal irqchip state of an interrupt,
2864 * depending on the value of @which.
2865 *
2866 * This function should be called with migration disabled if the
2867 * interrupt controller has per-cpu registers.
2868 */
2869int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2870 bool val)
2871{
2872 struct irq_desc *desc;
2873 struct irq_data *data;
2874 struct irq_chip *chip;
2875 unsigned long flags;
2876 int err = -EINVAL;
2877
2878 desc = irq_get_desc_buslock(irq, &flags, 0);
2879 if (!desc)
2880 return err;
2881
2882 data = irq_desc_get_irq_data(desc);
2883
2884 do {
2885 chip = irq_data_get_irq_chip(data);
2886 if (WARN_ON_ONCE(!chip)) {
2887 err = -ENODEV;
2888 goto out_unlock;
2889 }
2890 if (chip->irq_set_irqchip_state)
2891 break;
2892#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2893 data = data->parent_data;
2894#else
2895 data = NULL;
2896#endif
2897 } while (data);
2898
2899 if (data)
2900 err = chip->irq_set_irqchip_state(data, which, val);
2901
2902out_unlock:
2903 irq_put_desc_busunlock(desc, flags);
2904 return err;
2905}
2906EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2907
2908/**
2909 * irq_has_action - Check whether an interrupt is requested
2910 * @irq: The linux irq number
2911 *
2912 * Returns: A snapshot of the current state
2913 */
2914bool irq_has_action(unsigned int irq)
2915{
2916 bool res;
2917
2918 rcu_read_lock();
2919 res = irq_desc_has_action(irq_to_desc(irq));
2920 rcu_read_unlock();
2921 return res;
2922}
2923EXPORT_SYMBOL_GPL(irq_has_action);
2924
2925/**
2926 * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2927 * @irq: The linux irq number
2928 * @bitmask: The bitmask to evaluate
2929 *
2930 * Returns: True if one of the bits in @bitmask is set
2931 */
2932bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2933{
2934 struct irq_desc *desc;
2935 bool res = false;
2936
2937 rcu_read_lock();
2938 desc = irq_to_desc(irq);
2939 if (desc)
2940 res = !!(desc->status_use_accessors & bitmask);
2941 rcu_read_unlock();
2942 return res;
2943}
2944EXPORT_SYMBOL_GPL(irq_check_status_bit);