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