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