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