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