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