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 : __read_mostly bool force_irqthreads;
29 : EXPORT_SYMBOL_GPL(force_irqthreads);
30 :
31 0 : static int __init setup_forced_irqthreads(char *arg)
32 : {
33 0 : force_irqthreads = true;
34 0 : return 0;
35 : }
36 : early_param("threadirqs", setup_forced_irqthreads);
37 : #endif
38 :
39 0 : static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip)
40 : {
41 0 : struct irq_data *irqd = irq_desc_get_irq_data(desc);
42 : bool inprogress;
43 :
44 : do {
45 : unsigned long flags;
46 :
47 : /*
48 : * Wait until we're out of the critical section. This might
49 : * give the wrong answer due to the lack of memory barriers.
50 : */
51 0 : while (irqd_irq_inprogress(&desc->irq_data))
52 0 : cpu_relax();
53 :
54 : /* Ok, that indicated we're done: double-check carefully. */
55 0 : raw_spin_lock_irqsave(&desc->lock, flags);
56 0 : inprogress = irqd_irq_inprogress(&desc->irq_data);
57 :
58 : /*
59 : * If requested and supported, check at the chip whether it
60 : * is in flight at the hardware level, i.e. already pending
61 : * in a CPU and waiting for service and acknowledge.
62 : */
63 0 : if (!inprogress && sync_chip) {
64 : /*
65 : * Ignore the return code. inprogress is only updated
66 : * when the chip supports it.
67 : */
68 0 : __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE,
69 : &inprogress);
70 : }
71 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
72 :
73 : /* Oops, that failed? */
74 0 : } while (inprogress);
75 0 : }
76 :
77 : /**
78 : * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
79 : * @irq: interrupt number to wait for
80 : *
81 : * This function waits for any pending hard IRQ handlers for this
82 : * interrupt to complete before returning. If you use this
83 : * function while holding a resource the IRQ handler may need you
84 : * will deadlock. It does not take associated threaded handlers
85 : * into account.
86 : *
87 : * Do not use this for shutdown scenarios where you must be sure
88 : * that all parts (hardirq and threaded handler) have completed.
89 : *
90 : * Returns: false if a threaded handler is active.
91 : *
92 : * This function may be called - with care - from IRQ context.
93 : *
94 : * It does not check whether there is an interrupt in flight at the
95 : * hardware level, but not serviced yet, as this might deadlock when
96 : * called with interrupts disabled and the target CPU of the interrupt
97 : * is the current CPU.
98 : */
99 0 : bool synchronize_hardirq(unsigned int irq)
100 : {
101 0 : struct irq_desc *desc = irq_to_desc(irq);
102 :
103 0 : if (desc) {
104 0 : __synchronize_hardirq(desc, false);
105 0 : return !atomic_read(&desc->threads_active);
106 : }
107 :
108 : return true;
109 : }
110 : EXPORT_SYMBOL(synchronize_hardirq);
111 :
112 : /**
113 : * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
114 : * @irq: interrupt number to wait for
115 : *
116 : * This function waits for any pending IRQ handlers for this interrupt
117 : * to complete before returning. If you use this function while
118 : * holding a resource the IRQ handler may need you will deadlock.
119 : *
120 : * Can only be called from preemptible code as it might sleep when
121 : * an interrupt thread is associated to @irq.
122 : *
123 : * It optionally makes sure (when the irq chip supports that method)
124 : * that the interrupt is not pending in any CPU and waiting for
125 : * service.
126 : */
127 0 : void synchronize_irq(unsigned int irq)
128 : {
129 0 : struct irq_desc *desc = irq_to_desc(irq);
130 :
131 0 : if (desc) {
132 0 : __synchronize_hardirq(desc, true);
133 : /*
134 : * We made sure that no hardirq handler is
135 : * running. Now verify that no threaded handlers are
136 : * active.
137 : */
138 0 : wait_event(desc->wait_for_threads,
139 : !atomic_read(&desc->threads_active));
140 : }
141 0 : }
142 : EXPORT_SYMBOL(synchronize_irq);
143 :
144 : #ifdef CONFIG_SMP
145 : cpumask_var_t irq_default_affinity;
146 :
147 4 : static bool __irq_can_set_affinity(struct irq_desc *desc)
148 : {
149 4 : if (!desc || !irqd_can_balance(&desc->irq_data) ||
150 4 : !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
151 1 : return false;
152 : return true;
153 : }
154 :
155 : /**
156 : * irq_can_set_affinity - Check if the affinity of a given irq can be set
157 : * @irq: Interrupt to check
158 : *
159 : */
160 0 : int irq_can_set_affinity(unsigned int irq)
161 : {
162 0 : return __irq_can_set_affinity(irq_to_desc(irq));
163 : }
164 :
165 : /**
166 : * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
167 : * @irq: Interrupt to check
168 : *
169 : * Like irq_can_set_affinity() above, but additionally checks for the
170 : * AFFINITY_MANAGED flag.
171 : */
172 0 : bool irq_can_set_affinity_usr(unsigned int irq)
173 : {
174 0 : struct irq_desc *desc = irq_to_desc(irq);
175 :
176 0 : return __irq_can_set_affinity(desc) &&
177 0 : !irqd_affinity_is_managed(&desc->irq_data);
178 : }
179 :
180 : /**
181 : * irq_set_thread_affinity - Notify irq threads to adjust affinity
182 : * @desc: irq descriptor which has affitnity changed
183 : *
184 : * We just set IRQTF_AFFINITY and delegate the affinity setting
185 : * to the interrupt thread itself. We can not call
186 : * set_cpus_allowed_ptr() here as we hold desc->lock and this
187 : * code can be called from hard interrupt context.
188 : */
189 3 : void irq_set_thread_affinity(struct irq_desc *desc)
190 : {
191 3 : struct irqaction *action;
192 :
193 3 : for_each_action_of_desc(desc, action)
194 0 : if (action->thread)
195 0 : set_bit(IRQTF_AFFINITY, &action->thread_flags);
196 3 : }
197 :
198 : #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
199 3 : static void irq_validate_effective_affinity(struct irq_data *data)
200 : {
201 3 : const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
202 3 : struct irq_chip *chip = irq_data_get_irq_chip(data);
203 :
204 3 : if (!cpumask_empty(m))
205 : return;
206 0 : pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
207 : chip->name, data->irq);
208 : }
209 :
210 0 : static inline void irq_init_effective_affinity(struct irq_data *data,
211 : const struct cpumask *mask)
212 : {
213 0 : cpumask_copy(irq_data_get_effective_affinity_mask(data), mask);
214 : }
215 : #else
216 : static inline void irq_validate_effective_affinity(struct irq_data *data) { }
217 : static inline void irq_init_effective_affinity(struct irq_data *data,
218 : const struct cpumask *mask) { }
219 : #endif
220 :
221 3 : int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
222 : bool force)
223 : {
224 3 : struct irq_desc *desc = irq_data_to_desc(data);
225 3 : struct irq_chip *chip = irq_data_get_irq_chip(data);
226 3 : int ret;
227 :
228 3 : if (!chip || !chip->irq_set_affinity)
229 : return -EINVAL;
230 :
231 : /*
232 : * If this is a managed interrupt and housekeeping is enabled on
233 : * it check whether the requested affinity mask intersects with
234 : * a housekeeping CPU. If so, then remove the isolated CPUs from
235 : * the mask and just keep the housekeeping CPU(s). This prevents
236 : * the affinity setter from routing the interrupt to an isolated
237 : * CPU to avoid that I/O submitted from a housekeeping CPU causes
238 : * interrupts on an isolated one.
239 : *
240 : * If the masks do not intersect or include online CPU(s) then
241 : * keep the requested mask. The isolated target CPUs are only
242 : * receiving interrupts when the I/O operation was submitted
243 : * directly from them.
244 : *
245 : * If all housekeeping CPUs in the affinity mask are offline, the
246 : * interrupt will be migrated by the CPU hotplug code once a
247 : * housekeeping CPU which belongs to the affinity mask comes
248 : * online.
249 : */
250 3 : if (irqd_affinity_is_managed(data) &&
251 3 : housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) {
252 : const struct cpumask *hk_mask, *prog_mask;
253 :
254 : static DEFINE_RAW_SPINLOCK(tmp_mask_lock);
255 : static struct cpumask tmp_mask;
256 :
257 : hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
258 :
259 : raw_spin_lock(&tmp_mask_lock);
260 : cpumask_and(&tmp_mask, mask, hk_mask);
261 : if (!cpumask_intersects(&tmp_mask, cpu_online_mask))
262 : prog_mask = mask;
263 : else
264 : prog_mask = &tmp_mask;
265 : ret = chip->irq_set_affinity(data, prog_mask, force);
266 : raw_spin_unlock(&tmp_mask_lock);
267 : } else {
268 3 : ret = chip->irq_set_affinity(data, mask, force);
269 : }
270 3 : switch (ret) {
271 3 : case IRQ_SET_MASK_OK:
272 : case IRQ_SET_MASK_OK_DONE:
273 3 : cpumask_copy(desc->irq_common_data.affinity, mask);
274 3 : fallthrough;
275 3 : case IRQ_SET_MASK_OK_NOCOPY:
276 3 : irq_validate_effective_affinity(data);
277 3 : irq_set_thread_affinity(desc);
278 3 : ret = 0;
279 : }
280 :
281 : return ret;
282 : }
283 :
284 : #ifdef CONFIG_GENERIC_PENDING_IRQ
285 0 : static inline int irq_set_affinity_pending(struct irq_data *data,
286 : const struct cpumask *dest)
287 : {
288 0 : struct irq_desc *desc = irq_data_to_desc(data);
289 :
290 0 : irqd_set_move_pending(data);
291 0 : irq_copy_pending(desc, dest);
292 0 : return 0;
293 : }
294 : #else
295 : static inline int irq_set_affinity_pending(struct irq_data *data,
296 : const struct cpumask *dest)
297 : {
298 : return -EBUSY;
299 : }
300 : #endif
301 :
302 0 : static int irq_try_set_affinity(struct irq_data *data,
303 : const struct cpumask *dest, bool force)
304 : {
305 0 : int ret = irq_do_set_affinity(data, dest, force);
306 :
307 : /*
308 : * In case that the underlying vector management is busy and the
309 : * architecture supports the generic pending mechanism then utilize
310 : * this to avoid returning an error to user space.
311 : */
312 0 : if (ret == -EBUSY && !force)
313 0 : ret = irq_set_affinity_pending(data, dest);
314 0 : return ret;
315 : }
316 :
317 0 : static bool irq_set_affinity_deactivated(struct irq_data *data,
318 : const struct cpumask *mask, bool force)
319 : {
320 0 : struct irq_desc *desc = irq_data_to_desc(data);
321 :
322 : /*
323 : * Handle irq chips which can handle affinity only in activated
324 : * state correctly
325 : *
326 : * If the interrupt is not yet activated, just store the affinity
327 : * mask and do not call the chip driver at all. On activation the
328 : * driver has to make sure anyway that the interrupt is in a
329 : * useable state so startup works.
330 : */
331 0 : if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) ||
332 0 : irqd_is_activated(data) || !irqd_affinity_on_activate(data))
333 : return false;
334 :
335 0 : cpumask_copy(desc->irq_common_data.affinity, mask);
336 0 : irq_init_effective_affinity(data, mask);
337 0 : irqd_set(data, IRQD_AFFINITY_SET);
338 0 : return true;
339 : }
340 :
341 0 : int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
342 : bool force)
343 : {
344 0 : struct irq_chip *chip = irq_data_get_irq_chip(data);
345 0 : struct irq_desc *desc = irq_data_to_desc(data);
346 0 : int ret = 0;
347 :
348 0 : if (!chip || !chip->irq_set_affinity)
349 : return -EINVAL;
350 :
351 0 : if (irq_set_affinity_deactivated(data, mask, force))
352 : return 0;
353 :
354 0 : if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) {
355 0 : ret = irq_try_set_affinity(data, mask, force);
356 : } else {
357 0 : irqd_set_move_pending(data);
358 0 : irq_copy_pending(desc, mask);
359 : }
360 :
361 0 : if (desc->affinity_notify) {
362 0 : kref_get(&desc->affinity_notify->kref);
363 0 : if (!schedule_work(&desc->affinity_notify->work)) {
364 : /* Work was already scheduled, drop our extra ref */
365 0 : kref_put(&desc->affinity_notify->kref,
366 0 : desc->affinity_notify->release);
367 : }
368 : }
369 0 : irqd_set(data, IRQD_AFFINITY_SET);
370 :
371 0 : return ret;
372 : }
373 :
374 : /**
375 : * irq_update_affinity_desc - Update affinity management for an interrupt
376 : * @irq: The interrupt number to update
377 : * @affinity: Pointer to the affinity descriptor
378 : *
379 : * This interface can be used to configure the affinity management of
380 : * interrupts which have been allocated already.
381 : *
382 : * There are certain limitations on when it may be used - attempts to use it
383 : * for when the kernel is configured for generic IRQ reservation mode (in
384 : * config GENERIC_IRQ_RESERVATION_MODE) will fail, as it may conflict with
385 : * managed/non-managed interrupt accounting. In addition, attempts to use it on
386 : * an interrupt which is already started or which has already been configured
387 : * as managed will also fail, as these mean invalid init state or double init.
388 : */
389 0 : int irq_update_affinity_desc(unsigned int irq,
390 : struct irq_affinity_desc *affinity)
391 : {
392 0 : struct irq_desc *desc;
393 0 : unsigned long flags;
394 0 : bool activated;
395 0 : int ret = 0;
396 :
397 : /*
398 : * Supporting this with the reservation scheme used by x86 needs
399 : * some more thought. Fail it for now.
400 : */
401 0 : if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
402 0 : return -EOPNOTSUPP;
403 :
404 : desc = irq_get_desc_buslock(irq, &flags, 0);
405 : if (!desc)
406 : return -EINVAL;
407 :
408 : /* Requires the interrupt to be shut down */
409 : if (irqd_is_started(&desc->irq_data)) {
410 : ret = -EBUSY;
411 : goto out_unlock;
412 : }
413 :
414 : /* Interrupts which are already managed cannot be modified */
415 : if (irqd_affinity_is_managed(&desc->irq_data)) {
416 : ret = -EBUSY;
417 : goto out_unlock;
418 : }
419 :
420 : /*
421 : * Deactivate the interrupt. That's required to undo
422 : * anything an earlier activation has established.
423 : */
424 : activated = irqd_is_activated(&desc->irq_data);
425 : if (activated)
426 : irq_domain_deactivate_irq(&desc->irq_data);
427 :
428 : if (affinity->is_managed) {
429 : irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
430 : irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
431 : }
432 :
433 : cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
434 :
435 : /* Restore the activation state */
436 : if (activated)
437 : irq_domain_activate_irq(&desc->irq_data, false);
438 :
439 : out_unlock:
440 : irq_put_desc_busunlock(desc, flags);
441 : return ret;
442 : }
443 :
444 0 : int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
445 : {
446 0 : struct irq_desc *desc = irq_to_desc(irq);
447 0 : unsigned long flags;
448 0 : int ret;
449 :
450 0 : if (!desc)
451 : return -EINVAL;
452 :
453 0 : raw_spin_lock_irqsave(&desc->lock, flags);
454 0 : ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
455 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
456 0 : return ret;
457 : }
458 :
459 0 : int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
460 : {
461 0 : unsigned long flags;
462 0 : struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
463 :
464 0 : if (!desc)
465 : return -EINVAL;
466 0 : desc->affinity_hint = m;
467 0 : irq_put_desc_unlock(desc, flags);
468 : /* set the initial affinity to prevent every interrupt being on CPU0 */
469 0 : if (m)
470 0 : __irq_set_affinity(irq, m, false);
471 : return 0;
472 : }
473 : EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
474 :
475 0 : static void irq_affinity_notify(struct work_struct *work)
476 : {
477 0 : struct irq_affinity_notify *notify =
478 0 : container_of(work, struct irq_affinity_notify, work);
479 0 : struct irq_desc *desc = irq_to_desc(notify->irq);
480 0 : cpumask_var_t cpumask;
481 0 : unsigned long flags;
482 :
483 0 : if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
484 0 : goto out;
485 :
486 0 : raw_spin_lock_irqsave(&desc->lock, flags);
487 0 : if (irq_move_pending(&desc->irq_data))
488 0 : irq_get_pending(cpumask, desc);
489 : else
490 0 : cpumask_copy(cpumask, desc->irq_common_data.affinity);
491 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
492 :
493 0 : notify->notify(notify, cpumask);
494 :
495 0 : free_cpumask_var(cpumask);
496 0 : out:
497 0 : kref_put(¬ify->kref, notify->release);
498 0 : }
499 :
500 : /**
501 : * irq_set_affinity_notifier - control notification of IRQ affinity changes
502 : * @irq: Interrupt for which to enable/disable notification
503 : * @notify: Context for notification, or %NULL to disable
504 : * notification. Function pointers must be initialised;
505 : * the other fields will be initialised by this function.
506 : *
507 : * Must be called in process context. Notification may only be enabled
508 : * after the IRQ is allocated and must be disabled before the IRQ is
509 : * freed using free_irq().
510 : */
511 : int
512 0 : irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
513 : {
514 0 : struct irq_desc *desc = irq_to_desc(irq);
515 0 : struct irq_affinity_notify *old_notify;
516 0 : unsigned long flags;
517 :
518 : /* The release function is promised process context */
519 0 : might_sleep();
520 :
521 0 : if (!desc || desc->istate & IRQS_NMI)
522 : return -EINVAL;
523 :
524 : /* Complete initialisation of *notify */
525 0 : if (notify) {
526 0 : notify->irq = irq;
527 0 : kref_init(¬ify->kref);
528 0 : INIT_WORK(¬ify->work, irq_affinity_notify);
529 : }
530 :
531 0 : raw_spin_lock_irqsave(&desc->lock, flags);
532 0 : old_notify = desc->affinity_notify;
533 0 : desc->affinity_notify = notify;
534 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
535 :
536 0 : if (old_notify) {
537 0 : if (cancel_work_sync(&old_notify->work)) {
538 : /* Pending work had a ref, put that one too */
539 0 : kref_put(&old_notify->kref, old_notify->release);
540 : }
541 0 : kref_put(&old_notify->kref, old_notify->release);
542 : }
543 :
544 : return 0;
545 : }
546 : EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
547 :
548 : #ifndef CONFIG_AUTO_IRQ_AFFINITY
549 : /*
550 : * Generic version of the affinity autoselector.
551 : */
552 4 : int irq_setup_affinity(struct irq_desc *desc)
553 : {
554 4 : struct cpumask *set = irq_default_affinity;
555 4 : int ret, node = irq_desc_get_node(desc);
556 4 : static DEFINE_RAW_SPINLOCK(mask_lock);
557 4 : static struct cpumask mask;
558 :
559 : /* Excludes PER_CPU and NO_BALANCE interrupts */
560 4 : if (!__irq_can_set_affinity(desc))
561 : return 0;
562 :
563 3 : raw_spin_lock(&mask_lock);
564 : /*
565 : * Preserve the managed affinity setting and a userspace affinity
566 : * setup, but make sure that one of the targets is online.
567 : */
568 3 : if (irqd_affinity_is_managed(&desc->irq_data) ||
569 3 : irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
570 0 : if (cpumask_intersects(desc->irq_common_data.affinity,
571 : cpu_online_mask))
572 0 : set = desc->irq_common_data.affinity;
573 : else
574 0 : irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
575 : }
576 :
577 3 : cpumask_and(&mask, cpu_online_mask, set);
578 3 : if (cpumask_empty(&mask))
579 0 : cpumask_copy(&mask, cpu_online_mask);
580 :
581 3 : if (node != NUMA_NO_NODE) {
582 3 : const struct cpumask *nodemask = cpumask_of_node(node);
583 :
584 : /* make sure at least one of the cpus in nodemask is online */
585 3 : if (cpumask_intersects(&mask, nodemask))
586 3 : cpumask_and(&mask, &mask, nodemask);
587 : }
588 3 : ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
589 3 : raw_spin_unlock(&mask_lock);
590 3 : return ret;
591 : }
592 : #else
593 : /* Wrapper for ALPHA specific affinity selector magic */
594 : int irq_setup_affinity(struct irq_desc *desc)
595 : {
596 : return irq_select_affinity(irq_desc_get_irq(desc));
597 : }
598 : #endif /* CONFIG_AUTO_IRQ_AFFINITY */
599 : #endif /* CONFIG_SMP */
600 :
601 :
602 : /**
603 : * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
604 : * @irq: interrupt number to set affinity
605 : * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
606 : * specific data for percpu_devid interrupts
607 : *
608 : * This function uses the vCPU specific data to set the vCPU
609 : * affinity for an irq. The vCPU specific data is passed from
610 : * outside, such as KVM. One example code path is as below:
611 : * KVM -> IOMMU -> irq_set_vcpu_affinity().
612 : */
613 0 : int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
614 : {
615 0 : unsigned long flags;
616 0 : struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
617 0 : struct irq_data *data;
618 0 : struct irq_chip *chip;
619 0 : int ret = -ENOSYS;
620 :
621 0 : if (!desc)
622 : return -EINVAL;
623 :
624 0 : data = irq_desc_get_irq_data(desc);
625 0 : do {
626 0 : chip = irq_data_get_irq_chip(data);
627 0 : if (chip && chip->irq_set_vcpu_affinity)
628 : break;
629 : #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
630 0 : data = data->parent_data;
631 : #else
632 : data = NULL;
633 : #endif
634 0 : } while (data);
635 :
636 0 : if (data)
637 0 : ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
638 0 : irq_put_desc_unlock(desc, flags);
639 :
640 0 : return ret;
641 : }
642 : EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
643 :
644 0 : void __disable_irq(struct irq_desc *desc)
645 : {
646 0 : if (!desc->depth++)
647 0 : irq_disable(desc);
648 0 : }
649 :
650 0 : static int __disable_irq_nosync(unsigned int irq)
651 : {
652 0 : unsigned long flags;
653 0 : struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
654 :
655 0 : if (!desc)
656 : return -EINVAL;
657 0 : __disable_irq(desc);
658 0 : irq_put_desc_busunlock(desc, flags);
659 0 : return 0;
660 : }
661 :
662 : /**
663 : * disable_irq_nosync - disable an irq without waiting
664 : * @irq: Interrupt to disable
665 : *
666 : * Disable the selected interrupt line. Disables and Enables are
667 : * nested.
668 : * Unlike disable_irq(), this function does not ensure existing
669 : * instances of the IRQ handler have completed before returning.
670 : *
671 : * This function may be called from IRQ context.
672 : */
673 0 : void disable_irq_nosync(unsigned int irq)
674 : {
675 0 : __disable_irq_nosync(irq);
676 0 : }
677 : EXPORT_SYMBOL(disable_irq_nosync);
678 :
679 : /**
680 : * disable_irq - disable an irq and wait for completion
681 : * @irq: Interrupt to disable
682 : *
683 : * Disable the selected interrupt line. Enables and Disables are
684 : * nested.
685 : * This function waits for any pending IRQ handlers for this interrupt
686 : * to complete before returning. If you use this function while
687 : * holding a resource the IRQ handler may need you will deadlock.
688 : *
689 : * This function may be called - with care - from IRQ context.
690 : */
691 0 : void disable_irq(unsigned int irq)
692 : {
693 0 : if (!__disable_irq_nosync(irq))
694 0 : synchronize_irq(irq);
695 0 : }
696 : EXPORT_SYMBOL(disable_irq);
697 :
698 : /**
699 : * disable_hardirq - disables an irq and waits for hardirq completion
700 : * @irq: Interrupt to disable
701 : *
702 : * Disable the selected interrupt line. Enables and Disables are
703 : * nested.
704 : * This function waits for any pending hard IRQ handlers for this
705 : * interrupt to complete before returning. If you use this function while
706 : * holding a resource the hard IRQ handler may need you will deadlock.
707 : *
708 : * When used to optimistically disable an interrupt from atomic context
709 : * the return value must be checked.
710 : *
711 : * Returns: false if a threaded handler is active.
712 : *
713 : * This function may be called - with care - from IRQ context.
714 : */
715 0 : bool disable_hardirq(unsigned int irq)
716 : {
717 0 : if (!__disable_irq_nosync(irq))
718 0 : return synchronize_hardirq(irq);
719 :
720 : return false;
721 : }
722 : EXPORT_SYMBOL_GPL(disable_hardirq);
723 :
724 : /**
725 : * disable_nmi_nosync - disable an nmi without waiting
726 : * @irq: Interrupt to disable
727 : *
728 : * Disable the selected interrupt line. Disables and enables are
729 : * nested.
730 : * The interrupt to disable must have been requested through request_nmi.
731 : * Unlike disable_nmi(), this function does not ensure existing
732 : * instances of the IRQ handler have completed before returning.
733 : */
734 0 : void disable_nmi_nosync(unsigned int irq)
735 : {
736 0 : disable_irq_nosync(irq);
737 0 : }
738 :
739 0 : void __enable_irq(struct irq_desc *desc)
740 : {
741 0 : switch (desc->depth) {
742 : case 0:
743 0 : err_out:
744 0 : WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
745 : irq_desc_get_irq(desc));
746 0 : break;
747 0 : case 1: {
748 0 : if (desc->istate & IRQS_SUSPENDED)
749 0 : goto err_out;
750 : /* Prevent probing on this irq: */
751 0 : irq_settings_set_noprobe(desc);
752 : /*
753 : * Call irq_startup() not irq_enable() here because the
754 : * interrupt might be marked NOAUTOEN. So irq_startup()
755 : * needs to be invoked when it gets enabled the first
756 : * time. If it was already started up, then irq_startup()
757 : * will invoke irq_enable() under the hood.
758 : */
759 0 : irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
760 0 : break;
761 : }
762 0 : default:
763 0 : desc->depth--;
764 : }
765 0 : }
766 :
767 : /**
768 : * enable_irq - enable handling of an irq
769 : * @irq: Interrupt to enable
770 : *
771 : * Undoes the effect of one call to disable_irq(). If this
772 : * matches the last disable, processing of interrupts on this
773 : * IRQ line is re-enabled.
774 : *
775 : * This function may be called from IRQ context only when
776 : * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
777 : */
778 0 : void enable_irq(unsigned int irq)
779 : {
780 0 : unsigned long flags;
781 0 : struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
782 :
783 0 : if (!desc)
784 0 : return;
785 0 : if (WARN(!desc->irq_data.chip,
786 : KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
787 0 : goto out;
788 :
789 0 : __enable_irq(desc);
790 0 : out:
791 0 : irq_put_desc_busunlock(desc, flags);
792 : }
793 : EXPORT_SYMBOL(enable_irq);
794 :
795 : /**
796 : * enable_nmi - enable handling of an nmi
797 : * @irq: Interrupt to enable
798 : *
799 : * The interrupt to enable must have been requested through request_nmi.
800 : * Undoes the effect of one call to disable_nmi(). If this
801 : * matches the last disable, processing of interrupts on this
802 : * IRQ line is re-enabled.
803 : */
804 0 : void enable_nmi(unsigned int irq)
805 : {
806 0 : enable_irq(irq);
807 0 : }
808 :
809 0 : static int set_irq_wake_real(unsigned int irq, unsigned int on)
810 : {
811 0 : struct irq_desc *desc = irq_to_desc(irq);
812 0 : int ret = -ENXIO;
813 :
814 0 : if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE)
815 : return 0;
816 :
817 0 : if (desc->irq_data.chip->irq_set_wake)
818 0 : ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
819 :
820 : return ret;
821 : }
822 :
823 : /**
824 : * irq_set_irq_wake - control irq power management wakeup
825 : * @irq: interrupt to control
826 : * @on: enable/disable power management wakeup
827 : *
828 : * Enable/disable power management wakeup mode, which is
829 : * disabled by default. Enables and disables must match,
830 : * just as they match for non-wakeup mode support.
831 : *
832 : * Wakeup mode lets this IRQ wake the system from sleep
833 : * states like "suspend to RAM".
834 : *
835 : * Note: irq enable/disable state is completely orthogonal
836 : * to the enable/disable state of irq wake. An irq can be
837 : * disabled with disable_irq() and still wake the system as
838 : * long as the irq has wake enabled. If this does not hold,
839 : * then the underlying irq chip and the related driver need
840 : * to be investigated.
841 : */
842 0 : int irq_set_irq_wake(unsigned int irq, unsigned int on)
843 : {
844 0 : unsigned long flags;
845 0 : struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
846 0 : int ret = 0;
847 :
848 0 : if (!desc)
849 : return -EINVAL;
850 :
851 : /* Don't use NMIs as wake up interrupts please */
852 0 : if (desc->istate & IRQS_NMI) {
853 0 : ret = -EINVAL;
854 0 : goto out_unlock;
855 : }
856 :
857 : /* wakeup-capable irqs can be shared between drivers that
858 : * don't need to have the same sleep mode behaviors.
859 : */
860 0 : if (on) {
861 0 : if (desc->wake_depth++ == 0) {
862 0 : ret = set_irq_wake_real(irq, on);
863 0 : if (ret)
864 0 : desc->wake_depth = 0;
865 : else
866 0 : irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
867 : }
868 : } else {
869 0 : if (desc->wake_depth == 0) {
870 0 : WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
871 0 : } else if (--desc->wake_depth == 0) {
872 0 : ret = set_irq_wake_real(irq, on);
873 0 : if (ret)
874 0 : desc->wake_depth = 1;
875 : else
876 0 : irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
877 : }
878 : }
879 :
880 0 : out_unlock:
881 0 : irq_put_desc_busunlock(desc, flags);
882 0 : return ret;
883 : }
884 : EXPORT_SYMBOL(irq_set_irq_wake);
885 :
886 : /*
887 : * Internal function that tells the architecture code whether a
888 : * particular irq has been exclusively allocated or is available
889 : * for driver use.
890 : */
891 0 : int can_request_irq(unsigned int irq, unsigned long irqflags)
892 : {
893 0 : unsigned long flags;
894 0 : struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
895 0 : int canrequest = 0;
896 :
897 0 : if (!desc)
898 : return 0;
899 :
900 0 : if (irq_settings_can_request(desc)) {
901 0 : if (!desc->action ||
902 0 : irqflags & desc->action->flags & IRQF_SHARED)
903 0 : canrequest = 1;
904 : }
905 0 : irq_put_desc_unlock(desc, flags);
906 0 : return canrequest;
907 : }
908 :
909 0 : int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
910 : {
911 0 : struct irq_chip *chip = desc->irq_data.chip;
912 0 : int ret, unmask = 0;
913 :
914 0 : if (!chip || !chip->irq_set_type) {
915 : /*
916 : * IRQF_TRIGGER_* but the PIC does not support multiple
917 : * flow-types?
918 : */
919 : pr_debug("No set_type function for IRQ %d (%s)\n",
920 : irq_desc_get_irq(desc),
921 : chip ? (chip->name ? : "unknown") : "unknown");
922 : return 0;
923 : }
924 :
925 0 : if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
926 0 : if (!irqd_irq_masked(&desc->irq_data))
927 0 : mask_irq(desc);
928 0 : if (!irqd_irq_disabled(&desc->irq_data))
929 0 : unmask = 1;
930 : }
931 :
932 : /* Mask all flags except trigger mode */
933 0 : flags &= IRQ_TYPE_SENSE_MASK;
934 0 : ret = chip->irq_set_type(&desc->irq_data, flags);
935 :
936 0 : switch (ret) {
937 0 : case IRQ_SET_MASK_OK:
938 : case IRQ_SET_MASK_OK_DONE:
939 0 : irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
940 0 : irqd_set(&desc->irq_data, flags);
941 0 : fallthrough;
942 :
943 0 : case IRQ_SET_MASK_OK_NOCOPY:
944 0 : flags = irqd_get_trigger_type(&desc->irq_data);
945 0 : irq_settings_set_trigger_mask(desc, flags);
946 0 : irqd_clear(&desc->irq_data, IRQD_LEVEL);
947 0 : irq_settings_clr_level(desc);
948 0 : if (flags & IRQ_TYPE_LEVEL_MASK) {
949 0 : irq_settings_set_level(desc);
950 0 : irqd_set(&desc->irq_data, IRQD_LEVEL);
951 : }
952 :
953 : ret = 0;
954 : break;
955 0 : default:
956 0 : pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n",
957 : flags, irq_desc_get_irq(desc), chip->irq_set_type);
958 : }
959 0 : if (unmask)
960 0 : unmask_irq(desc);
961 : return ret;
962 : }
963 :
964 : #ifdef CONFIG_HARDIRQS_SW_RESEND
965 0 : int irq_set_parent(int irq, int parent_irq)
966 : {
967 0 : unsigned long flags;
968 0 : struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
969 :
970 0 : if (!desc)
971 : return -EINVAL;
972 :
973 0 : desc->parent_irq = parent_irq;
974 :
975 0 : irq_put_desc_unlock(desc, flags);
976 0 : return 0;
977 : }
978 : EXPORT_SYMBOL_GPL(irq_set_parent);
979 : #endif
980 :
981 : /*
982 : * Default primary interrupt handler for threaded interrupts. Is
983 : * assigned as primary handler when request_threaded_irq is called
984 : * with handler == NULL. Useful for oneshot interrupts.
985 : */
986 0 : static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
987 : {
988 0 : return IRQ_WAKE_THREAD;
989 : }
990 :
991 : /*
992 : * Primary handler for nested threaded interrupts. Should never be
993 : * called.
994 : */
995 0 : static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
996 : {
997 0 : WARN(1, "Primary handler called for nested irq %d\n", irq);
998 0 : return IRQ_NONE;
999 : }
1000 :
1001 0 : static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
1002 : {
1003 0 : WARN(1, "Secondary action handler called for irq %d\n", irq);
1004 0 : return IRQ_NONE;
1005 : }
1006 :
1007 0 : static int irq_wait_for_interrupt(struct irqaction *action)
1008 : {
1009 0 : for (;;) {
1010 0 : set_current_state(TASK_INTERRUPTIBLE);
1011 :
1012 0 : if (kthread_should_stop()) {
1013 : /* may need to run one last time */
1014 0 : if (test_and_clear_bit(IRQTF_RUNTHREAD,
1015 0 : &action->thread_flags)) {
1016 0 : __set_current_state(TASK_RUNNING);
1017 0 : return 0;
1018 : }
1019 0 : __set_current_state(TASK_RUNNING);
1020 0 : return -1;
1021 : }
1022 :
1023 0 : if (test_and_clear_bit(IRQTF_RUNTHREAD,
1024 0 : &action->thread_flags)) {
1025 0 : __set_current_state(TASK_RUNNING);
1026 0 : return 0;
1027 : }
1028 0 : schedule();
1029 : }
1030 : }
1031 :
1032 : /*
1033 : * Oneshot interrupts keep the irq line masked until the threaded
1034 : * handler finished. unmask if the interrupt has not been disabled and
1035 : * is marked MASKED.
1036 : */
1037 0 : static void irq_finalize_oneshot(struct irq_desc *desc,
1038 : struct irqaction *action)
1039 : {
1040 0 : if (!(desc->istate & IRQS_ONESHOT) ||
1041 0 : action->handler == irq_forced_secondary_handler)
1042 : return;
1043 0 : again:
1044 0 : chip_bus_lock(desc);
1045 0 : raw_spin_lock_irq(&desc->lock);
1046 :
1047 : /*
1048 : * Implausible though it may be we need to protect us against
1049 : * the following scenario:
1050 : *
1051 : * The thread is faster done than the hard interrupt handler
1052 : * on the other CPU. If we unmask the irq line then the
1053 : * interrupt can come in again and masks the line, leaves due
1054 : * to IRQS_INPROGRESS and the irq line is masked forever.
1055 : *
1056 : * This also serializes the state of shared oneshot handlers
1057 : * versus "desc->threads_onehsot |= action->thread_mask;" in
1058 : * irq_wake_thread(). See the comment there which explains the
1059 : * serialization.
1060 : */
1061 0 : if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
1062 0 : raw_spin_unlock_irq(&desc->lock);
1063 0 : chip_bus_sync_unlock(desc);
1064 0 : cpu_relax();
1065 0 : goto again;
1066 : }
1067 :
1068 : /*
1069 : * Now check again, whether the thread should run. Otherwise
1070 : * we would clear the threads_oneshot bit of this thread which
1071 : * was just set.
1072 : */
1073 0 : if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1074 0 : goto out_unlock;
1075 :
1076 0 : desc->threads_oneshot &= ~action->thread_mask;
1077 :
1078 0 : if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
1079 0 : irqd_irq_masked(&desc->irq_data))
1080 0 : unmask_threaded_irq(desc);
1081 :
1082 0 : out_unlock:
1083 0 : raw_spin_unlock_irq(&desc->lock);
1084 0 : chip_bus_sync_unlock(desc);
1085 : }
1086 :
1087 : #ifdef CONFIG_SMP
1088 : /*
1089 : * Check whether we need to change the affinity of the interrupt thread.
1090 : */
1091 : static void
1092 0 : irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
1093 : {
1094 0 : cpumask_var_t mask;
1095 0 : bool valid = true;
1096 :
1097 0 : if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
1098 0 : return;
1099 :
1100 : /*
1101 : * In case we are out of memory we set IRQTF_AFFINITY again and
1102 : * try again next time
1103 : */
1104 0 : if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1105 : set_bit(IRQTF_AFFINITY, &action->thread_flags);
1106 : return;
1107 : }
1108 :
1109 0 : raw_spin_lock_irq(&desc->lock);
1110 : /*
1111 : * This code is triggered unconditionally. Check the affinity
1112 : * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
1113 : */
1114 0 : if (cpumask_available(desc->irq_common_data.affinity)) {
1115 0 : const struct cpumask *m;
1116 :
1117 0 : m = irq_data_get_effective_affinity_mask(&desc->irq_data);
1118 0 : cpumask_copy(mask, m);
1119 : } else {
1120 : valid = false;
1121 : }
1122 0 : raw_spin_unlock_irq(&desc->lock);
1123 :
1124 0 : if (valid)
1125 0 : set_cpus_allowed_ptr(current, mask);
1126 0 : free_cpumask_var(mask);
1127 : }
1128 : #else
1129 : static inline void
1130 : irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
1131 : #endif
1132 :
1133 : /*
1134 : * Interrupts which are not explicitly requested as threaded
1135 : * interrupts rely on the implicit bh/preempt disable of the hard irq
1136 : * context. So we need to disable bh here to avoid deadlocks and other
1137 : * side effects.
1138 : */
1139 : static irqreturn_t
1140 0 : irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
1141 : {
1142 0 : irqreturn_t ret;
1143 :
1144 0 : local_bh_disable();
1145 0 : ret = action->thread_fn(action->irq, action->dev_id);
1146 0 : if (ret == IRQ_HANDLED)
1147 0 : atomic_inc(&desc->threads_handled);
1148 :
1149 0 : irq_finalize_oneshot(desc, action);
1150 0 : local_bh_enable();
1151 0 : return ret;
1152 : }
1153 :
1154 : /*
1155 : * Interrupts explicitly requested as threaded interrupts want to be
1156 : * preemtible - many of them need to sleep and wait for slow busses to
1157 : * complete.
1158 : */
1159 0 : static irqreturn_t irq_thread_fn(struct irq_desc *desc,
1160 : struct irqaction *action)
1161 : {
1162 0 : irqreturn_t ret;
1163 :
1164 0 : ret = action->thread_fn(action->irq, action->dev_id);
1165 0 : if (ret == IRQ_HANDLED)
1166 0 : atomic_inc(&desc->threads_handled);
1167 :
1168 0 : irq_finalize_oneshot(desc, action);
1169 0 : return ret;
1170 : }
1171 :
1172 0 : static void wake_threads_waitq(struct irq_desc *desc)
1173 : {
1174 0 : if (atomic_dec_and_test(&desc->threads_active))
1175 0 : wake_up(&desc->wait_for_threads);
1176 0 : }
1177 :
1178 0 : static void irq_thread_dtor(struct callback_head *unused)
1179 : {
1180 0 : struct task_struct *tsk = current;
1181 0 : struct irq_desc *desc;
1182 0 : struct irqaction *action;
1183 :
1184 0 : if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
1185 : return;
1186 :
1187 0 : action = kthread_data(tsk);
1188 :
1189 0 : pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
1190 : tsk->comm, tsk->pid, action->irq);
1191 :
1192 :
1193 0 : desc = irq_to_desc(action->irq);
1194 : /*
1195 : * If IRQTF_RUNTHREAD is set, we need to decrement
1196 : * desc->threads_active and wake possible waiters.
1197 : */
1198 0 : if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
1199 0 : wake_threads_waitq(desc);
1200 :
1201 : /* Prevent a stale desc->threads_oneshot */
1202 0 : irq_finalize_oneshot(desc, action);
1203 : }
1204 :
1205 0 : static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
1206 : {
1207 0 : struct irqaction *secondary = action->secondary;
1208 :
1209 0 : if (WARN_ON_ONCE(!secondary))
1210 : return;
1211 :
1212 0 : raw_spin_lock_irq(&desc->lock);
1213 0 : __irq_wake_thread(desc, secondary);
1214 0 : raw_spin_unlock_irq(&desc->lock);
1215 : }
1216 :
1217 : /*
1218 : * Interrupt handler thread
1219 : */
1220 0 : static int irq_thread(void *data)
1221 : {
1222 0 : struct callback_head on_exit_work;
1223 0 : struct irqaction *action = data;
1224 0 : struct irq_desc *desc = irq_to_desc(action->irq);
1225 0 : irqreturn_t (*handler_fn)(struct irq_desc *desc,
1226 : struct irqaction *action);
1227 :
1228 0 : if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
1229 0 : &action->thread_flags))
1230 : handler_fn = irq_forced_thread_fn;
1231 : else
1232 : handler_fn = irq_thread_fn;
1233 :
1234 0 : init_task_work(&on_exit_work, irq_thread_dtor);
1235 0 : task_work_add(current, &on_exit_work, TWA_NONE);
1236 :
1237 0 : irq_thread_check_affinity(desc, action);
1238 :
1239 0 : while (!irq_wait_for_interrupt(action)) {
1240 0 : irqreturn_t action_ret;
1241 :
1242 0 : irq_thread_check_affinity(desc, action);
1243 :
1244 0 : action_ret = handler_fn(desc, action);
1245 0 : if (action_ret == IRQ_WAKE_THREAD)
1246 0 : irq_wake_secondary(desc, action);
1247 :
1248 0 : wake_threads_waitq(desc);
1249 : }
1250 :
1251 : /*
1252 : * This is the regular exit path. __free_irq() is stopping the
1253 : * thread via kthread_stop() after calling
1254 : * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the
1255 : * oneshot mask bit can be set.
1256 : */
1257 0 : task_work_cancel(current, irq_thread_dtor);
1258 0 : return 0;
1259 : }
1260 :
1261 : /**
1262 : * irq_wake_thread - wake the irq thread for the action identified by dev_id
1263 : * @irq: Interrupt line
1264 : * @dev_id: Device identity for which the thread should be woken
1265 : *
1266 : */
1267 0 : void irq_wake_thread(unsigned int irq, void *dev_id)
1268 : {
1269 0 : struct irq_desc *desc = irq_to_desc(irq);
1270 0 : struct irqaction *action;
1271 0 : unsigned long flags;
1272 :
1273 0 : if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1274 : return;
1275 :
1276 0 : raw_spin_lock_irqsave(&desc->lock, flags);
1277 0 : for_each_action_of_desc(desc, action) {
1278 0 : if (action->dev_id == dev_id) {
1279 0 : if (action->thread)
1280 0 : __irq_wake_thread(desc, action);
1281 : break;
1282 : }
1283 : }
1284 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
1285 : }
1286 : EXPORT_SYMBOL_GPL(irq_wake_thread);
1287 :
1288 4 : static int irq_setup_forced_threading(struct irqaction *new)
1289 : {
1290 4 : if (!force_irqthreads)
1291 : return 0;
1292 0 : if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1293 : return 0;
1294 :
1295 : /*
1296 : * No further action required for interrupts which are requested as
1297 : * threaded interrupts already
1298 : */
1299 0 : if (new->handler == irq_default_primary_handler)
1300 : return 0;
1301 :
1302 0 : new->flags |= IRQF_ONESHOT;
1303 :
1304 : /*
1305 : * Handle the case where we have a real primary handler and a
1306 : * thread handler. We force thread them as well by creating a
1307 : * secondary action.
1308 : */
1309 0 : if (new->handler && new->thread_fn) {
1310 : /* Allocate the secondary action */
1311 0 : new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1312 0 : if (!new->secondary)
1313 : return -ENOMEM;
1314 0 : new->secondary->handler = irq_forced_secondary_handler;
1315 0 : new->secondary->thread_fn = new->thread_fn;
1316 0 : new->secondary->dev_id = new->dev_id;
1317 0 : new->secondary->irq = new->irq;
1318 0 : new->secondary->name = new->name;
1319 : }
1320 : /* Deal with the primary handler */
1321 0 : set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1322 0 : new->thread_fn = new->handler;
1323 0 : new->handler = irq_default_primary_handler;
1324 0 : return 0;
1325 : }
1326 :
1327 4 : static int irq_request_resources(struct irq_desc *desc)
1328 : {
1329 4 : struct irq_data *d = &desc->irq_data;
1330 4 : struct irq_chip *c = d->chip;
1331 :
1332 0 : return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1333 : }
1334 :
1335 0 : static void irq_release_resources(struct irq_desc *desc)
1336 : {
1337 0 : struct irq_data *d = &desc->irq_data;
1338 0 : struct irq_chip *c = d->chip;
1339 :
1340 0 : if (c->irq_release_resources)
1341 0 : c->irq_release_resources(d);
1342 : }
1343 :
1344 0 : static bool irq_supports_nmi(struct irq_desc *desc)
1345 : {
1346 0 : struct irq_data *d = irq_desc_get_irq_data(desc);
1347 :
1348 : #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1349 : /* Only IRQs directly managed by the root irqchip can be set as NMI */
1350 0 : if (d->parent_data)
1351 : return false;
1352 : #endif
1353 : /* Don't support NMIs for chips behind a slow bus */
1354 0 : if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock)
1355 : return false;
1356 :
1357 0 : return d->chip->flags & IRQCHIP_SUPPORTS_NMI;
1358 : }
1359 :
1360 0 : static int irq_nmi_setup(struct irq_desc *desc)
1361 : {
1362 0 : struct irq_data *d = irq_desc_get_irq_data(desc);
1363 0 : struct irq_chip *c = d->chip;
1364 :
1365 0 : return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL;
1366 : }
1367 :
1368 0 : static void irq_nmi_teardown(struct irq_desc *desc)
1369 : {
1370 0 : struct irq_data *d = irq_desc_get_irq_data(desc);
1371 0 : struct irq_chip *c = d->chip;
1372 :
1373 0 : if (c->irq_nmi_teardown)
1374 0 : c->irq_nmi_teardown(d);
1375 : }
1376 :
1377 : static int
1378 0 : setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1379 : {
1380 0 : struct task_struct *t;
1381 :
1382 0 : if (!secondary) {
1383 0 : t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1384 : new->name);
1385 : } else {
1386 0 : t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1387 : new->name);
1388 : }
1389 :
1390 0 : if (IS_ERR(t))
1391 0 : return PTR_ERR(t);
1392 :
1393 0 : sched_set_fifo(t);
1394 :
1395 : /*
1396 : * We keep the reference to the task struct even if
1397 : * the thread dies to avoid that the interrupt code
1398 : * references an already freed task_struct.
1399 : */
1400 0 : new->thread = get_task_struct(t);
1401 : /*
1402 : * Tell the thread to set its affinity. This is
1403 : * important for shared interrupt handlers as we do
1404 : * not invoke setup_affinity() for the secondary
1405 : * handlers as everything is already set up. Even for
1406 : * interrupts marked with IRQF_NO_BALANCE this is
1407 : * correct as we want the thread to move to the cpu(s)
1408 : * on which the requesting code placed the interrupt.
1409 : */
1410 0 : set_bit(IRQTF_AFFINITY, &new->thread_flags);
1411 0 : return 0;
1412 : }
1413 :
1414 : /*
1415 : * Internal function to register an irqaction - typically used to
1416 : * allocate special interrupts that are part of the architecture.
1417 : *
1418 : * Locking rules:
1419 : *
1420 : * desc->request_mutex Provides serialization against a concurrent free_irq()
1421 : * chip_bus_lock Provides serialization for slow bus operations
1422 : * desc->lock Provides serialization against hard interrupts
1423 : *
1424 : * chip_bus_lock and desc->lock are sufficient for all other management and
1425 : * interrupt related functions. desc->request_mutex solely serializes
1426 : * request/free_irq().
1427 : */
1428 : static int
1429 4 : __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1430 : {
1431 4 : struct irqaction *old, **old_ptr;
1432 4 : unsigned long flags, thread_mask = 0;
1433 4 : int ret, nested, shared = 0;
1434 :
1435 4 : if (!desc)
1436 : return -EINVAL;
1437 :
1438 4 : if (desc->irq_data.chip == &no_irq_chip)
1439 : return -ENOSYS;
1440 4 : if (!try_module_get(desc->owner))
1441 : return -ENODEV;
1442 :
1443 4 : new->irq = irq;
1444 :
1445 : /*
1446 : * If the trigger type is not specified by the caller,
1447 : * then use the default for this interrupt.
1448 : */
1449 4 : if (!(new->flags & IRQF_TRIGGER_MASK))
1450 4 : new->flags |= irqd_get_trigger_type(&desc->irq_data);
1451 :
1452 : /*
1453 : * Check whether the interrupt nests into another interrupt
1454 : * thread.
1455 : */
1456 4 : nested = irq_settings_is_nested_thread(desc);
1457 4 : if (nested) {
1458 0 : if (!new->thread_fn) {
1459 0 : ret = -EINVAL;
1460 0 : goto out_mput;
1461 : }
1462 : /*
1463 : * Replace the primary handler which was provided from
1464 : * the driver for non nested interrupt handling by the
1465 : * dummy function which warns when called.
1466 : */
1467 0 : new->handler = irq_nested_primary_handler;
1468 : } else {
1469 4 : if (irq_settings_can_thread(desc)) {
1470 4 : ret = irq_setup_forced_threading(new);
1471 4 : if (ret)
1472 0 : goto out_mput;
1473 : }
1474 : }
1475 :
1476 : /*
1477 : * Create a handler thread when a thread function is supplied
1478 : * and the interrupt does not nest into another interrupt
1479 : * thread.
1480 : */
1481 4 : if (new->thread_fn && !nested) {
1482 0 : ret = setup_irq_thread(new, irq, false);
1483 0 : if (ret)
1484 0 : goto out_mput;
1485 0 : if (new->secondary) {
1486 0 : ret = setup_irq_thread(new->secondary, irq, true);
1487 0 : if (ret)
1488 0 : goto out_thread;
1489 : }
1490 : }
1491 :
1492 : /*
1493 : * Drivers are often written to work w/o knowledge about the
1494 : * underlying irq chip implementation, so a request for a
1495 : * threaded irq without a primary hard irq context handler
1496 : * requires the ONESHOT flag to be set. Some irq chips like
1497 : * MSI based interrupts are per se one shot safe. Check the
1498 : * chip flags, so we can avoid the unmask dance at the end of
1499 : * the threaded handler for those.
1500 : */
1501 4 : if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1502 0 : new->flags &= ~IRQF_ONESHOT;
1503 :
1504 : /*
1505 : * Protects against a concurrent __free_irq() call which might wait
1506 : * for synchronize_hardirq() to complete without holding the optional
1507 : * chip bus lock and desc->lock. Also protects against handing out
1508 : * a recycled oneshot thread_mask bit while it's still in use by
1509 : * its previous owner.
1510 : */
1511 4 : mutex_lock(&desc->request_mutex);
1512 :
1513 : /*
1514 : * Acquire bus lock as the irq_request_resources() callback below
1515 : * might rely on the serialization or the magic power management
1516 : * functions which are abusing the irq_bus_lock() callback,
1517 : */
1518 4 : chip_bus_lock(desc);
1519 :
1520 : /* First installed action requests resources. */
1521 4 : if (!desc->action) {
1522 4 : ret = irq_request_resources(desc);
1523 0 : if (ret) {
1524 0 : pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1525 : new->name, irq, desc->irq_data.chip->name);
1526 0 : goto out_bus_unlock;
1527 : }
1528 : }
1529 :
1530 : /*
1531 : * The following block of code has to be executed atomically
1532 : * protected against a concurrent interrupt and any of the other
1533 : * management calls which are not serialized via
1534 : * desc->request_mutex or the optional bus lock.
1535 : */
1536 4 : raw_spin_lock_irqsave(&desc->lock, flags);
1537 4 : old_ptr = &desc->action;
1538 4 : old = *old_ptr;
1539 4 : if (old) {
1540 : /*
1541 : * Can't share interrupts unless both agree to and are
1542 : * the same type (level, edge, polarity). So both flag
1543 : * fields must have IRQF_SHARED set and the bits which
1544 : * set the trigger type must match. Also all must
1545 : * agree on ONESHOT.
1546 : * Interrupt lines used for NMIs cannot be shared.
1547 : */
1548 0 : unsigned int oldtype;
1549 :
1550 0 : if (desc->istate & IRQS_NMI) {
1551 0 : pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
1552 : new->name, irq, desc->irq_data.chip->name);
1553 0 : ret = -EINVAL;
1554 0 : goto out_unlock;
1555 : }
1556 :
1557 : /*
1558 : * If nobody did set the configuration before, inherit
1559 : * the one provided by the requester.
1560 : */
1561 0 : if (irqd_trigger_type_was_set(&desc->irq_data)) {
1562 0 : oldtype = irqd_get_trigger_type(&desc->irq_data);
1563 : } else {
1564 0 : oldtype = new->flags & IRQF_TRIGGER_MASK;
1565 0 : irqd_set_trigger_type(&desc->irq_data, oldtype);
1566 : }
1567 :
1568 0 : if (!((old->flags & new->flags) & IRQF_SHARED) ||
1569 0 : (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1570 0 : ((old->flags ^ new->flags) & IRQF_ONESHOT))
1571 0 : goto mismatch;
1572 :
1573 : /* All handlers must agree on per-cpuness */
1574 0 : if ((old->flags & IRQF_PERCPU) !=
1575 : (new->flags & IRQF_PERCPU))
1576 0 : goto mismatch;
1577 :
1578 : /* add new interrupt at end of irq queue */
1579 0 : do {
1580 : /*
1581 : * Or all existing action->thread_mask bits,
1582 : * so we can find the next zero bit for this
1583 : * new action.
1584 : */
1585 0 : thread_mask |= old->thread_mask;
1586 0 : old_ptr = &old->next;
1587 0 : old = *old_ptr;
1588 0 : } while (old);
1589 : shared = 1;
1590 : }
1591 :
1592 : /*
1593 : * Setup the thread mask for this irqaction for ONESHOT. For
1594 : * !ONESHOT irqs the thread mask is 0 so we can avoid a
1595 : * conditional in irq_wake_thread().
1596 : */
1597 4 : if (new->flags & IRQF_ONESHOT) {
1598 : /*
1599 : * Unlikely to have 32 resp 64 irqs sharing one line,
1600 : * but who knows.
1601 : */
1602 0 : if (thread_mask == ~0UL) {
1603 0 : ret = -EBUSY;
1604 0 : goto out_unlock;
1605 : }
1606 : /*
1607 : * The thread_mask for the action is or'ed to
1608 : * desc->thread_active to indicate that the
1609 : * IRQF_ONESHOT thread handler has been woken, but not
1610 : * yet finished. The bit is cleared when a thread
1611 : * completes. When all threads of a shared interrupt
1612 : * line have completed desc->threads_active becomes
1613 : * zero and the interrupt line is unmasked. See
1614 : * handle.c:irq_wake_thread() for further information.
1615 : *
1616 : * If no thread is woken by primary (hard irq context)
1617 : * interrupt handlers, then desc->threads_active is
1618 : * also checked for zero to unmask the irq line in the
1619 : * affected hard irq flow handlers
1620 : * (handle_[fasteoi|level]_irq).
1621 : *
1622 : * The new action gets the first zero bit of
1623 : * thread_mask assigned. See the loop above which or's
1624 : * all existing action->thread_mask bits.
1625 : */
1626 0 : new->thread_mask = 1UL << ffz(thread_mask);
1627 :
1628 4 : } else if (new->handler == irq_default_primary_handler &&
1629 0 : !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1630 : /*
1631 : * The interrupt was requested with handler = NULL, so
1632 : * we use the default primary handler for it. But it
1633 : * does not have the oneshot flag set. In combination
1634 : * with level interrupts this is deadly, because the
1635 : * default primary handler just wakes the thread, then
1636 : * the irq lines is reenabled, but the device still
1637 : * has the level irq asserted. Rinse and repeat....
1638 : *
1639 : * While this works for edge type interrupts, we play
1640 : * it safe and reject unconditionally because we can't
1641 : * say for sure which type this interrupt really
1642 : * has. The type flags are unreliable as the
1643 : * underlying chip implementation can override them.
1644 : */
1645 0 : pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n",
1646 : new->name, irq);
1647 0 : ret = -EINVAL;
1648 0 : goto out_unlock;
1649 : }
1650 :
1651 4 : if (!shared) {
1652 4 : init_waitqueue_head(&desc->wait_for_threads);
1653 :
1654 : /* Setup the type (level, edge polarity) if configured: */
1655 4 : if (new->flags & IRQF_TRIGGER_MASK) {
1656 0 : ret = __irq_set_trigger(desc,
1657 : new->flags & IRQF_TRIGGER_MASK);
1658 :
1659 0 : if (ret)
1660 0 : goto out_unlock;
1661 : }
1662 :
1663 : /*
1664 : * Activate the interrupt. That activation must happen
1665 : * independently of IRQ_NOAUTOEN. request_irq() can fail
1666 : * and the callers are supposed to handle
1667 : * that. enable_irq() of an interrupt requested with
1668 : * IRQ_NOAUTOEN is not supposed to fail. The activation
1669 : * keeps it in shutdown mode, it merily associates
1670 : * resources if necessary and if that's not possible it
1671 : * fails. Interrupts which are in managed shutdown mode
1672 : * will simply ignore that activation request.
1673 : */
1674 4 : ret = irq_activate(desc);
1675 4 : if (ret)
1676 0 : goto out_unlock;
1677 :
1678 4 : desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1679 : IRQS_ONESHOT | IRQS_WAITING);
1680 4 : irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1681 :
1682 4 : if (new->flags & IRQF_PERCPU) {
1683 0 : irqd_set(&desc->irq_data, IRQD_PER_CPU);
1684 0 : irq_settings_set_per_cpu(desc);
1685 : }
1686 :
1687 4 : if (new->flags & IRQF_ONESHOT)
1688 0 : desc->istate |= IRQS_ONESHOT;
1689 :
1690 : /* Exclude IRQ from balancing if requested */
1691 4 : if (new->flags & IRQF_NOBALANCING) {
1692 0 : irq_settings_set_no_balancing(desc);
1693 0 : irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1694 : }
1695 :
1696 4 : if (irq_settings_can_autoenable(desc)) {
1697 4 : irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1698 : } else {
1699 : /*
1700 : * Shared interrupts do not go well with disabling
1701 : * auto enable. The sharing interrupt might request
1702 : * it while it's still disabled and then wait for
1703 : * interrupts forever.
1704 : */
1705 0 : WARN_ON_ONCE(new->flags & IRQF_SHARED);
1706 : /* Undo nested disables: */
1707 0 : desc->depth = 1;
1708 : }
1709 :
1710 0 : } else if (new->flags & IRQF_TRIGGER_MASK) {
1711 0 : unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1712 0 : unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1713 :
1714 0 : if (nmsk != omsk)
1715 : /* hope the handler works with current trigger mode */
1716 0 : pr_warn("irq %d uses trigger mode %u; requested %u\n",
1717 : irq, omsk, nmsk);
1718 : }
1719 :
1720 4 : *old_ptr = new;
1721 :
1722 4 : irq_pm_install_action(desc, new);
1723 :
1724 : /* Reset broken irq detection when installing new handler */
1725 4 : desc->irq_count = 0;
1726 4 : desc->irqs_unhandled = 0;
1727 :
1728 : /*
1729 : * Check whether we disabled the irq via the spurious handler
1730 : * before. Reenable it and give it another chance.
1731 : */
1732 4 : if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1733 0 : desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1734 0 : __enable_irq(desc);
1735 : }
1736 :
1737 4 : raw_spin_unlock_irqrestore(&desc->lock, flags);
1738 4 : chip_bus_sync_unlock(desc);
1739 4 : mutex_unlock(&desc->request_mutex);
1740 :
1741 4 : irq_setup_timings(desc, new);
1742 :
1743 : /*
1744 : * Strictly no need to wake it up, but hung_task complains
1745 : * when no hard interrupt wakes the thread up.
1746 : */
1747 4 : if (new->thread)
1748 0 : wake_up_process(new->thread);
1749 4 : if (new->secondary)
1750 0 : wake_up_process(new->secondary->thread);
1751 :
1752 4 : register_irq_proc(irq, desc);
1753 4 : new->dir = NULL;
1754 4 : register_handler_proc(irq, new);
1755 4 : return 0;
1756 :
1757 0 : mismatch:
1758 0 : if (!(new->flags & IRQF_PROBE_SHARED)) {
1759 0 : pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1760 : irq, new->flags, new->name, old->flags, old->name);
1761 : #ifdef CONFIG_DEBUG_SHIRQ
1762 : dump_stack();
1763 : #endif
1764 : }
1765 : ret = -EBUSY;
1766 :
1767 0 : out_unlock:
1768 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
1769 :
1770 0 : if (!desc->action)
1771 0 : irq_release_resources(desc);
1772 0 : out_bus_unlock:
1773 0 : chip_bus_sync_unlock(desc);
1774 0 : mutex_unlock(&desc->request_mutex);
1775 :
1776 0 : out_thread:
1777 0 : if (new->thread) {
1778 0 : struct task_struct *t = new->thread;
1779 :
1780 0 : new->thread = NULL;
1781 0 : kthread_stop(t);
1782 0 : put_task_struct(t);
1783 : }
1784 0 : if (new->secondary && new->secondary->thread) {
1785 0 : struct task_struct *t = new->secondary->thread;
1786 :
1787 0 : new->secondary->thread = NULL;
1788 0 : kthread_stop(t);
1789 0 : put_task_struct(t);
1790 : }
1791 0 : out_mput:
1792 0 : module_put(desc->owner);
1793 0 : return ret;
1794 : }
1795 :
1796 : /*
1797 : * Internal function to unregister an irqaction - used to free
1798 : * regular and special interrupts that are part of the architecture.
1799 : */
1800 0 : static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
1801 : {
1802 0 : unsigned irq = desc->irq_data.irq;
1803 0 : struct irqaction *action, **action_ptr;
1804 0 : unsigned long flags;
1805 :
1806 0 : WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1807 :
1808 0 : mutex_lock(&desc->request_mutex);
1809 0 : chip_bus_lock(desc);
1810 0 : raw_spin_lock_irqsave(&desc->lock, flags);
1811 :
1812 : /*
1813 : * There can be multiple actions per IRQ descriptor, find the right
1814 : * one based on the dev_id:
1815 : */
1816 0 : action_ptr = &desc->action;
1817 0 : for (;;) {
1818 0 : action = *action_ptr;
1819 :
1820 0 : if (!action) {
1821 0 : WARN(1, "Trying to free already-free IRQ %d\n", irq);
1822 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
1823 0 : chip_bus_sync_unlock(desc);
1824 0 : mutex_unlock(&desc->request_mutex);
1825 0 : return NULL;
1826 : }
1827 :
1828 0 : if (action->dev_id == dev_id)
1829 : break;
1830 0 : action_ptr = &action->next;
1831 : }
1832 :
1833 : /* Found it - now remove it from the list of entries: */
1834 0 : *action_ptr = action->next;
1835 :
1836 0 : irq_pm_remove_action(desc, action);
1837 :
1838 : /* If this was the last handler, shut down the IRQ line: */
1839 0 : if (!desc->action) {
1840 0 : irq_settings_clr_disable_unlazy(desc);
1841 : /* Only shutdown. Deactivate after synchronize_hardirq() */
1842 0 : irq_shutdown(desc);
1843 : }
1844 :
1845 : #ifdef CONFIG_SMP
1846 : /* make sure affinity_hint is cleaned up */
1847 0 : if (WARN_ON_ONCE(desc->affinity_hint))
1848 0 : desc->affinity_hint = NULL;
1849 : #endif
1850 :
1851 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
1852 : /*
1853 : * Drop bus_lock here so the changes which were done in the chip
1854 : * callbacks above are synced out to the irq chips which hang
1855 : * behind a slow bus (I2C, SPI) before calling synchronize_hardirq().
1856 : *
1857 : * Aside of that the bus_lock can also be taken from the threaded
1858 : * handler in irq_finalize_oneshot() which results in a deadlock
1859 : * because kthread_stop() would wait forever for the thread to
1860 : * complete, which is blocked on the bus lock.
1861 : *
1862 : * The still held desc->request_mutex() protects against a
1863 : * concurrent request_irq() of this irq so the release of resources
1864 : * and timing data is properly serialized.
1865 : */
1866 0 : chip_bus_sync_unlock(desc);
1867 :
1868 0 : unregister_handler_proc(irq, action);
1869 :
1870 : /*
1871 : * Make sure it's not being used on another CPU and if the chip
1872 : * supports it also make sure that there is no (not yet serviced)
1873 : * interrupt in flight at the hardware level.
1874 : */
1875 0 : __synchronize_hardirq(desc, true);
1876 :
1877 : #ifdef CONFIG_DEBUG_SHIRQ
1878 : /*
1879 : * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1880 : * event to happen even now it's being freed, so let's make sure that
1881 : * is so by doing an extra call to the handler ....
1882 : *
1883 : * ( We do this after actually deregistering it, to make sure that a
1884 : * 'real' IRQ doesn't run in parallel with our fake. )
1885 : */
1886 : if (action->flags & IRQF_SHARED) {
1887 : local_irq_save(flags);
1888 : action->handler(irq, dev_id);
1889 : local_irq_restore(flags);
1890 : }
1891 : #endif
1892 :
1893 : /*
1894 : * The action has already been removed above, but the thread writes
1895 : * its oneshot mask bit when it completes. Though request_mutex is
1896 : * held across this which prevents __setup_irq() from handing out
1897 : * the same bit to a newly requested action.
1898 : */
1899 0 : if (action->thread) {
1900 0 : kthread_stop(action->thread);
1901 0 : put_task_struct(action->thread);
1902 0 : if (action->secondary && action->secondary->thread) {
1903 0 : kthread_stop(action->secondary->thread);
1904 0 : put_task_struct(action->secondary->thread);
1905 : }
1906 : }
1907 :
1908 : /* Last action releases resources */
1909 0 : if (!desc->action) {
1910 : /*
1911 : * Reaquire bus lock as irq_release_resources() might
1912 : * require it to deallocate resources over the slow bus.
1913 : */
1914 0 : chip_bus_lock(desc);
1915 : /*
1916 : * There is no interrupt on the fly anymore. Deactivate it
1917 : * completely.
1918 : */
1919 0 : raw_spin_lock_irqsave(&desc->lock, flags);
1920 0 : irq_domain_deactivate_irq(&desc->irq_data);
1921 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
1922 :
1923 0 : irq_release_resources(desc);
1924 0 : chip_bus_sync_unlock(desc);
1925 0 : irq_remove_timings(desc);
1926 : }
1927 :
1928 0 : mutex_unlock(&desc->request_mutex);
1929 :
1930 0 : irq_chip_pm_put(&desc->irq_data);
1931 0 : module_put(desc->owner);
1932 0 : kfree(action->secondary);
1933 0 : return action;
1934 : }
1935 :
1936 : /**
1937 : * free_irq - free an interrupt allocated with request_irq
1938 : * @irq: Interrupt line to free
1939 : * @dev_id: Device identity to free
1940 : *
1941 : * Remove an interrupt handler. The handler is removed and if the
1942 : * interrupt line is no longer in use by any driver it is disabled.
1943 : * On a shared IRQ the caller must ensure the interrupt is disabled
1944 : * on the card it drives before calling this function. The function
1945 : * does not return until any executing interrupts for this IRQ
1946 : * have completed.
1947 : *
1948 : * This function must not be called from interrupt context.
1949 : *
1950 : * Returns the devname argument passed to request_irq.
1951 : */
1952 0 : const void *free_irq(unsigned int irq, void *dev_id)
1953 : {
1954 0 : struct irq_desc *desc = irq_to_desc(irq);
1955 0 : struct irqaction *action;
1956 0 : const char *devname;
1957 :
1958 0 : if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1959 : return NULL;
1960 :
1961 : #ifdef CONFIG_SMP
1962 0 : if (WARN_ON(desc->affinity_notify))
1963 0 : desc->affinity_notify = NULL;
1964 : #endif
1965 :
1966 0 : action = __free_irq(desc, dev_id);
1967 :
1968 0 : if (!action)
1969 : return NULL;
1970 :
1971 0 : devname = action->name;
1972 0 : kfree(action);
1973 0 : return devname;
1974 : }
1975 : EXPORT_SYMBOL(free_irq);
1976 :
1977 : /* This function must be called with desc->lock held */
1978 0 : static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc)
1979 : {
1980 0 : const char *devname = NULL;
1981 :
1982 0 : desc->istate &= ~IRQS_NMI;
1983 :
1984 0 : if (!WARN_ON(desc->action == NULL)) {
1985 0 : irq_pm_remove_action(desc, desc->action);
1986 0 : devname = desc->action->name;
1987 0 : unregister_handler_proc(irq, desc->action);
1988 :
1989 0 : kfree(desc->action);
1990 0 : desc->action = NULL;
1991 : }
1992 :
1993 0 : irq_settings_clr_disable_unlazy(desc);
1994 0 : irq_shutdown_and_deactivate(desc);
1995 :
1996 0 : irq_release_resources(desc);
1997 :
1998 0 : irq_chip_pm_put(&desc->irq_data);
1999 0 : module_put(desc->owner);
2000 :
2001 0 : return devname;
2002 : }
2003 :
2004 0 : const void *free_nmi(unsigned int irq, void *dev_id)
2005 : {
2006 0 : struct irq_desc *desc = irq_to_desc(irq);
2007 0 : unsigned long flags;
2008 0 : const void *devname;
2009 :
2010 0 : if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
2011 : return NULL;
2012 :
2013 0 : if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2014 : return NULL;
2015 :
2016 : /* NMI still enabled */
2017 0 : if (WARN_ON(desc->depth == 0))
2018 0 : disable_nmi_nosync(irq);
2019 :
2020 0 : raw_spin_lock_irqsave(&desc->lock, flags);
2021 :
2022 0 : irq_nmi_teardown(desc);
2023 0 : devname = __cleanup_nmi(irq, desc);
2024 :
2025 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
2026 :
2027 0 : return devname;
2028 : }
2029 :
2030 : /**
2031 : * request_threaded_irq - allocate an interrupt line
2032 : * @irq: Interrupt line to allocate
2033 : * @handler: Function to be called when the IRQ occurs.
2034 : * Primary handler for threaded interrupts
2035 : * If NULL and thread_fn != NULL the default
2036 : * primary handler is installed
2037 : * @thread_fn: Function called from the irq handler thread
2038 : * If NULL, no irq thread is created
2039 : * @irqflags: Interrupt type flags
2040 : * @devname: An ascii name for the claiming device
2041 : * @dev_id: A cookie passed back to the handler function
2042 : *
2043 : * This call allocates interrupt resources and enables the
2044 : * interrupt line and IRQ handling. From the point this
2045 : * call is made your handler function may be invoked. Since
2046 : * your handler function must clear any interrupt the board
2047 : * raises, you must take care both to initialise your hardware
2048 : * and to set up the interrupt handler in the right order.
2049 : *
2050 : * If you want to set up a threaded irq handler for your device
2051 : * then you need to supply @handler and @thread_fn. @handler is
2052 : * still called in hard interrupt context and has to check
2053 : * whether the interrupt originates from the device. If yes it
2054 : * needs to disable the interrupt on the device and return
2055 : * IRQ_WAKE_THREAD which will wake up the handler thread and run
2056 : * @thread_fn. This split handler design is necessary to support
2057 : * shared interrupts.
2058 : *
2059 : * Dev_id must be globally unique. Normally the address of the
2060 : * device data structure is used as the cookie. Since the handler
2061 : * receives this value it makes sense to use it.
2062 : *
2063 : * If your interrupt is shared you must pass a non NULL dev_id
2064 : * as this is required when freeing the interrupt.
2065 : *
2066 : * Flags:
2067 : *
2068 : * IRQF_SHARED Interrupt is shared
2069 : * IRQF_TRIGGER_* Specify active edge(s) or level
2070 : *
2071 : */
2072 4 : int request_threaded_irq(unsigned int irq, irq_handler_t handler,
2073 : irq_handler_t thread_fn, unsigned long irqflags,
2074 : const char *devname, void *dev_id)
2075 : {
2076 4 : struct irqaction *action;
2077 4 : struct irq_desc *desc;
2078 4 : int retval;
2079 :
2080 4 : if (irq == IRQ_NOTCONNECTED)
2081 : return -ENOTCONN;
2082 :
2083 : /*
2084 : * Sanity-check: shared interrupts must pass in a real dev-ID,
2085 : * otherwise we'll have trouble later trying to figure out
2086 : * which interrupt is which (messes up the interrupt freeing
2087 : * logic etc).
2088 : *
2089 : * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
2090 : * it cannot be set along with IRQF_NO_SUSPEND.
2091 : */
2092 4 : if (((irqflags & IRQF_SHARED) && !dev_id) ||
2093 4 : (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
2094 4 : ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
2095 : return -EINVAL;
2096 :
2097 4 : desc = irq_to_desc(irq);
2098 4 : if (!desc)
2099 : return -EINVAL;
2100 :
2101 4 : if (!irq_settings_can_request(desc) ||
2102 4 : WARN_ON(irq_settings_is_per_cpu_devid(desc)))
2103 : return -EINVAL;
2104 :
2105 4 : if (!handler) {
2106 0 : if (!thread_fn)
2107 : return -EINVAL;
2108 : handler = irq_default_primary_handler;
2109 : }
2110 :
2111 4 : action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2112 4 : if (!action)
2113 : return -ENOMEM;
2114 :
2115 4 : action->handler = handler;
2116 4 : action->thread_fn = thread_fn;
2117 4 : action->flags = irqflags;
2118 4 : action->name = devname;
2119 4 : action->dev_id = dev_id;
2120 :
2121 4 : retval = irq_chip_pm_get(&desc->irq_data);
2122 4 : if (retval < 0) {
2123 0 : kfree(action);
2124 0 : return retval;
2125 : }
2126 :
2127 4 : retval = __setup_irq(irq, desc, action);
2128 :
2129 4 : if (retval) {
2130 0 : irq_chip_pm_put(&desc->irq_data);
2131 0 : kfree(action->secondary);
2132 0 : kfree(action);
2133 : }
2134 :
2135 : #ifdef CONFIG_DEBUG_SHIRQ_FIXME
2136 : if (!retval && (irqflags & IRQF_SHARED)) {
2137 : /*
2138 : * It's a shared IRQ -- the driver ought to be prepared for it
2139 : * to happen immediately, so let's make sure....
2140 : * We disable the irq to make sure that a 'real' IRQ doesn't
2141 : * run in parallel with our fake.
2142 : */
2143 : unsigned long flags;
2144 :
2145 : disable_irq(irq);
2146 : local_irq_save(flags);
2147 :
2148 : handler(irq, dev_id);
2149 :
2150 : local_irq_restore(flags);
2151 : enable_irq(irq);
2152 : }
2153 : #endif
2154 : return retval;
2155 : }
2156 : EXPORT_SYMBOL(request_threaded_irq);
2157 :
2158 : /**
2159 : * request_any_context_irq - allocate an interrupt line
2160 : * @irq: Interrupt line to allocate
2161 : * @handler: Function to be called when the IRQ occurs.
2162 : * Threaded handler for threaded interrupts.
2163 : * @flags: Interrupt type flags
2164 : * @name: An ascii name for the claiming device
2165 : * @dev_id: A cookie passed back to the handler function
2166 : *
2167 : * This call allocates interrupt resources and enables the
2168 : * interrupt line and IRQ handling. It selects either a
2169 : * hardirq or threaded handling method depending on the
2170 : * context.
2171 : *
2172 : * On failure, it returns a negative value. On success,
2173 : * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
2174 : */
2175 0 : int request_any_context_irq(unsigned int irq, irq_handler_t handler,
2176 : unsigned long flags, const char *name, void *dev_id)
2177 : {
2178 0 : struct irq_desc *desc;
2179 0 : int ret;
2180 :
2181 0 : if (irq == IRQ_NOTCONNECTED)
2182 : return -ENOTCONN;
2183 :
2184 0 : desc = irq_to_desc(irq);
2185 0 : if (!desc)
2186 : return -EINVAL;
2187 :
2188 0 : if (irq_settings_is_nested_thread(desc)) {
2189 0 : ret = request_threaded_irq(irq, NULL, handler,
2190 : flags, name, dev_id);
2191 0 : return !ret ? IRQC_IS_NESTED : ret;
2192 : }
2193 :
2194 0 : ret = request_irq(irq, handler, flags, name, dev_id);
2195 0 : return !ret ? IRQC_IS_HARDIRQ : ret;
2196 : }
2197 : EXPORT_SYMBOL_GPL(request_any_context_irq);
2198 :
2199 : /**
2200 : * request_nmi - allocate an interrupt line for NMI delivery
2201 : * @irq: Interrupt line to allocate
2202 : * @handler: Function to be called when the IRQ occurs.
2203 : * Threaded handler for threaded interrupts.
2204 : * @irqflags: Interrupt type flags
2205 : * @name: An ascii name for the claiming device
2206 : * @dev_id: A cookie passed back to the handler function
2207 : *
2208 : * This call allocates interrupt resources and enables the
2209 : * interrupt line and IRQ handling. It sets up the IRQ line
2210 : * to be handled as an NMI.
2211 : *
2212 : * An interrupt line delivering NMIs cannot be shared and IRQ handling
2213 : * cannot be threaded.
2214 : *
2215 : * Interrupt lines requested for NMI delivering must produce per cpu
2216 : * interrupts and have auto enabling setting disabled.
2217 : *
2218 : * Dev_id must be globally unique. Normally the address of the
2219 : * device data structure is used as the cookie. Since the handler
2220 : * receives this value it makes sense to use it.
2221 : *
2222 : * If the interrupt line cannot be used to deliver NMIs, function
2223 : * will fail and return a negative value.
2224 : */
2225 0 : int request_nmi(unsigned int irq, irq_handler_t handler,
2226 : unsigned long irqflags, const char *name, void *dev_id)
2227 : {
2228 0 : struct irqaction *action;
2229 0 : struct irq_desc *desc;
2230 0 : unsigned long flags;
2231 0 : int retval;
2232 :
2233 0 : if (irq == IRQ_NOTCONNECTED)
2234 : return -ENOTCONN;
2235 :
2236 : /* NMI cannot be shared, used for Polling */
2237 0 : if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL))
2238 : return -EINVAL;
2239 :
2240 0 : if (!(irqflags & IRQF_PERCPU))
2241 : return -EINVAL;
2242 :
2243 0 : if (!handler)
2244 : return -EINVAL;
2245 :
2246 0 : desc = irq_to_desc(irq);
2247 :
2248 0 : if (!desc || irq_settings_can_autoenable(desc) ||
2249 0 : !irq_settings_can_request(desc) ||
2250 0 : WARN_ON(irq_settings_is_per_cpu_devid(desc)) ||
2251 0 : !irq_supports_nmi(desc))
2252 : return -EINVAL;
2253 :
2254 0 : action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2255 0 : if (!action)
2256 : return -ENOMEM;
2257 :
2258 0 : action->handler = handler;
2259 0 : action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING;
2260 0 : action->name = name;
2261 0 : action->dev_id = dev_id;
2262 :
2263 0 : retval = irq_chip_pm_get(&desc->irq_data);
2264 0 : if (retval < 0)
2265 0 : goto err_out;
2266 :
2267 0 : retval = __setup_irq(irq, desc, action);
2268 0 : if (retval)
2269 0 : goto err_irq_setup;
2270 :
2271 0 : raw_spin_lock_irqsave(&desc->lock, flags);
2272 :
2273 : /* Setup NMI state */
2274 0 : desc->istate |= IRQS_NMI;
2275 0 : retval = irq_nmi_setup(desc);
2276 0 : if (retval) {
2277 0 : __cleanup_nmi(irq, desc);
2278 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
2279 0 : return -EINVAL;
2280 : }
2281 :
2282 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
2283 :
2284 0 : return 0;
2285 :
2286 0 : err_irq_setup:
2287 0 : irq_chip_pm_put(&desc->irq_data);
2288 0 : err_out:
2289 0 : kfree(action);
2290 :
2291 0 : return retval;
2292 : }
2293 :
2294 0 : void enable_percpu_irq(unsigned int irq, unsigned int type)
2295 : {
2296 0 : unsigned int cpu = smp_processor_id();
2297 0 : unsigned long flags;
2298 0 : struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2299 :
2300 0 : if (!desc)
2301 0 : return;
2302 :
2303 : /*
2304 : * If the trigger type is not specified by the caller, then
2305 : * use the default for this interrupt.
2306 : */
2307 0 : type &= IRQ_TYPE_SENSE_MASK;
2308 0 : if (type == IRQ_TYPE_NONE)
2309 0 : type = irqd_get_trigger_type(&desc->irq_data);
2310 :
2311 0 : if (type != IRQ_TYPE_NONE) {
2312 0 : int ret;
2313 :
2314 0 : ret = __irq_set_trigger(desc, type);
2315 :
2316 0 : if (ret) {
2317 0 : WARN(1, "failed to set type for IRQ%d\n", irq);
2318 0 : goto out;
2319 : }
2320 : }
2321 :
2322 0 : irq_percpu_enable(desc, cpu);
2323 0 : out:
2324 0 : irq_put_desc_unlock(desc, flags);
2325 : }
2326 : EXPORT_SYMBOL_GPL(enable_percpu_irq);
2327 :
2328 0 : void enable_percpu_nmi(unsigned int irq, unsigned int type)
2329 : {
2330 0 : enable_percpu_irq(irq, type);
2331 0 : }
2332 :
2333 : /**
2334 : * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
2335 : * @irq: Linux irq number to check for
2336 : *
2337 : * Must be called from a non migratable context. Returns the enable
2338 : * state of a per cpu interrupt on the current cpu.
2339 : */
2340 0 : bool irq_percpu_is_enabled(unsigned int irq)
2341 : {
2342 0 : unsigned int cpu = smp_processor_id();
2343 0 : struct irq_desc *desc;
2344 0 : unsigned long flags;
2345 0 : bool is_enabled;
2346 :
2347 0 : desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2348 0 : if (!desc)
2349 : return false;
2350 :
2351 0 : is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
2352 0 : irq_put_desc_unlock(desc, flags);
2353 :
2354 0 : return is_enabled;
2355 : }
2356 : EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
2357 :
2358 0 : void disable_percpu_irq(unsigned int irq)
2359 : {
2360 0 : unsigned int cpu = smp_processor_id();
2361 0 : unsigned long flags;
2362 0 : struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
2363 :
2364 0 : if (!desc)
2365 0 : return;
2366 :
2367 0 : irq_percpu_disable(desc, cpu);
2368 0 : irq_put_desc_unlock(desc, flags);
2369 : }
2370 : EXPORT_SYMBOL_GPL(disable_percpu_irq);
2371 :
2372 0 : void disable_percpu_nmi(unsigned int irq)
2373 : {
2374 0 : disable_percpu_irq(irq);
2375 0 : }
2376 :
2377 : /*
2378 : * Internal function to unregister a percpu irqaction.
2379 : */
2380 0 : static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2381 : {
2382 0 : struct irq_desc *desc = irq_to_desc(irq);
2383 0 : struct irqaction *action;
2384 0 : unsigned long flags;
2385 :
2386 0 : WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
2387 :
2388 0 : if (!desc)
2389 : return NULL;
2390 :
2391 0 : raw_spin_lock_irqsave(&desc->lock, flags);
2392 :
2393 0 : action = desc->action;
2394 0 : if (!action || action->percpu_dev_id != dev_id) {
2395 0 : WARN(1, "Trying to free already-free IRQ %d\n", irq);
2396 0 : goto bad;
2397 : }
2398 :
2399 0 : if (!cpumask_empty(desc->percpu_enabled)) {
2400 0 : WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
2401 : irq, cpumask_first(desc->percpu_enabled));
2402 0 : goto bad;
2403 : }
2404 :
2405 : /* Found it - now remove it from the list of entries: */
2406 0 : desc->action = NULL;
2407 :
2408 0 : desc->istate &= ~IRQS_NMI;
2409 :
2410 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
2411 :
2412 0 : unregister_handler_proc(irq, action);
2413 :
2414 0 : irq_chip_pm_put(&desc->irq_data);
2415 0 : module_put(desc->owner);
2416 0 : return action;
2417 :
2418 0 : bad:
2419 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
2420 0 : return NULL;
2421 : }
2422 :
2423 : /**
2424 : * remove_percpu_irq - free a per-cpu interrupt
2425 : * @irq: Interrupt line to free
2426 : * @act: irqaction for the interrupt
2427 : *
2428 : * Used to remove interrupts statically setup by the early boot process.
2429 : */
2430 0 : void remove_percpu_irq(unsigned int irq, struct irqaction *act)
2431 : {
2432 0 : struct irq_desc *desc = irq_to_desc(irq);
2433 :
2434 0 : if (desc && irq_settings_is_per_cpu_devid(desc))
2435 0 : __free_percpu_irq(irq, act->percpu_dev_id);
2436 0 : }
2437 :
2438 : /**
2439 : * free_percpu_irq - free an interrupt allocated with request_percpu_irq
2440 : * @irq: Interrupt line to free
2441 : * @dev_id: Device identity to free
2442 : *
2443 : * Remove a percpu interrupt handler. The handler is removed, but
2444 : * the interrupt line is not disabled. This must be done on each
2445 : * CPU before calling this function. The function does not return
2446 : * until any executing interrupts for this IRQ have completed.
2447 : *
2448 : * This function must not be called from interrupt context.
2449 : */
2450 0 : void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2451 : {
2452 0 : struct irq_desc *desc = irq_to_desc(irq);
2453 :
2454 0 : if (!desc || !irq_settings_is_per_cpu_devid(desc))
2455 : return;
2456 :
2457 0 : chip_bus_lock(desc);
2458 0 : kfree(__free_percpu_irq(irq, dev_id));
2459 0 : chip_bus_sync_unlock(desc);
2460 : }
2461 : EXPORT_SYMBOL_GPL(free_percpu_irq);
2462 :
2463 0 : void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
2464 : {
2465 0 : struct irq_desc *desc = irq_to_desc(irq);
2466 :
2467 0 : if (!desc || !irq_settings_is_per_cpu_devid(desc))
2468 : return;
2469 :
2470 0 : if (WARN_ON(!(desc->istate & IRQS_NMI)))
2471 : return;
2472 :
2473 0 : kfree(__free_percpu_irq(irq, dev_id));
2474 : }
2475 :
2476 : /**
2477 : * setup_percpu_irq - setup a per-cpu interrupt
2478 : * @irq: Interrupt line to setup
2479 : * @act: irqaction for the interrupt
2480 : *
2481 : * Used to statically setup per-cpu interrupts in the early boot process.
2482 : */
2483 0 : int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2484 : {
2485 0 : struct irq_desc *desc = irq_to_desc(irq);
2486 0 : int retval;
2487 :
2488 0 : if (!desc || !irq_settings_is_per_cpu_devid(desc))
2489 : return -EINVAL;
2490 :
2491 0 : retval = irq_chip_pm_get(&desc->irq_data);
2492 0 : if (retval < 0)
2493 : return retval;
2494 :
2495 0 : retval = __setup_irq(irq, desc, act);
2496 :
2497 0 : if (retval)
2498 0 : irq_chip_pm_put(&desc->irq_data);
2499 :
2500 : return retval;
2501 : }
2502 :
2503 : /**
2504 : * __request_percpu_irq - allocate a percpu interrupt line
2505 : * @irq: Interrupt line to allocate
2506 : * @handler: Function to be called when the IRQ occurs.
2507 : * @flags: Interrupt type flags (IRQF_TIMER only)
2508 : * @devname: An ascii name for the claiming device
2509 : * @dev_id: A percpu cookie passed back to the handler function
2510 : *
2511 : * This call allocates interrupt resources and enables the
2512 : * interrupt on the local CPU. If the interrupt is supposed to be
2513 : * enabled on other CPUs, it has to be done on each CPU using
2514 : * enable_percpu_irq().
2515 : *
2516 : * Dev_id must be globally unique. It is a per-cpu variable, and
2517 : * the handler gets called with the interrupted CPU's instance of
2518 : * that variable.
2519 : */
2520 0 : int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2521 : unsigned long flags, const char *devname,
2522 : void __percpu *dev_id)
2523 : {
2524 0 : struct irqaction *action;
2525 0 : struct irq_desc *desc;
2526 0 : int retval;
2527 :
2528 0 : if (!dev_id)
2529 : return -EINVAL;
2530 :
2531 0 : desc = irq_to_desc(irq);
2532 0 : if (!desc || !irq_settings_can_request(desc) ||
2533 0 : !irq_settings_is_per_cpu_devid(desc))
2534 : return -EINVAL;
2535 :
2536 0 : if (flags && flags != IRQF_TIMER)
2537 : return -EINVAL;
2538 :
2539 0 : action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2540 0 : if (!action)
2541 : return -ENOMEM;
2542 :
2543 0 : action->handler = handler;
2544 0 : action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2545 0 : action->name = devname;
2546 0 : action->percpu_dev_id = dev_id;
2547 :
2548 0 : retval = irq_chip_pm_get(&desc->irq_data);
2549 0 : if (retval < 0) {
2550 0 : kfree(action);
2551 0 : return retval;
2552 : }
2553 :
2554 0 : retval = __setup_irq(irq, desc, action);
2555 :
2556 0 : if (retval) {
2557 0 : irq_chip_pm_put(&desc->irq_data);
2558 0 : kfree(action);
2559 : }
2560 :
2561 : return retval;
2562 : }
2563 : EXPORT_SYMBOL_GPL(__request_percpu_irq);
2564 :
2565 : /**
2566 : * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery
2567 : * @irq: Interrupt line to allocate
2568 : * @handler: Function to be called when the IRQ occurs.
2569 : * @name: An ascii name for the claiming device
2570 : * @dev_id: A percpu cookie passed back to the handler function
2571 : *
2572 : * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
2573 : * have to be setup on each CPU by calling prepare_percpu_nmi() before
2574 : * being enabled on the same CPU by using enable_percpu_nmi().
2575 : *
2576 : * Dev_id must be globally unique. It is a per-cpu variable, and
2577 : * the handler gets called with the interrupted CPU's instance of
2578 : * that variable.
2579 : *
2580 : * Interrupt lines requested for NMI delivering should have auto enabling
2581 : * setting disabled.
2582 : *
2583 : * If the interrupt line cannot be used to deliver NMIs, function
2584 : * will fail returning a negative value.
2585 : */
2586 0 : int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
2587 : const char *name, void __percpu *dev_id)
2588 : {
2589 0 : struct irqaction *action;
2590 0 : struct irq_desc *desc;
2591 0 : unsigned long flags;
2592 0 : int retval;
2593 :
2594 0 : if (!handler)
2595 : return -EINVAL;
2596 :
2597 0 : desc = irq_to_desc(irq);
2598 :
2599 0 : if (!desc || !irq_settings_can_request(desc) ||
2600 0 : !irq_settings_is_per_cpu_devid(desc) ||
2601 0 : irq_settings_can_autoenable(desc) ||
2602 0 : !irq_supports_nmi(desc))
2603 : return -EINVAL;
2604 :
2605 : /* The line cannot already be NMI */
2606 0 : if (desc->istate & IRQS_NMI)
2607 : return -EINVAL;
2608 :
2609 0 : action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2610 0 : if (!action)
2611 : return -ENOMEM;
2612 :
2613 0 : action->handler = handler;
2614 0 : action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
2615 : | IRQF_NOBALANCING;
2616 0 : action->name = name;
2617 0 : action->percpu_dev_id = dev_id;
2618 :
2619 0 : retval = irq_chip_pm_get(&desc->irq_data);
2620 0 : if (retval < 0)
2621 0 : goto err_out;
2622 :
2623 0 : retval = __setup_irq(irq, desc, action);
2624 0 : if (retval)
2625 0 : goto err_irq_setup;
2626 :
2627 0 : raw_spin_lock_irqsave(&desc->lock, flags);
2628 0 : desc->istate |= IRQS_NMI;
2629 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
2630 :
2631 0 : return 0;
2632 :
2633 0 : err_irq_setup:
2634 0 : irq_chip_pm_put(&desc->irq_data);
2635 0 : err_out:
2636 0 : kfree(action);
2637 :
2638 0 : return retval;
2639 : }
2640 :
2641 : /**
2642 : * prepare_percpu_nmi - performs CPU local setup for NMI delivery
2643 : * @irq: Interrupt line to prepare for NMI delivery
2644 : *
2645 : * This call prepares an interrupt line to deliver NMI on the current CPU,
2646 : * before that interrupt line gets enabled with enable_percpu_nmi().
2647 : *
2648 : * As a CPU local operation, this should be called from non-preemptible
2649 : * context.
2650 : *
2651 : * If the interrupt line cannot be used to deliver NMIs, function
2652 : * will fail returning a negative value.
2653 : */
2654 0 : int prepare_percpu_nmi(unsigned int irq)
2655 : {
2656 0 : unsigned long flags;
2657 0 : struct irq_desc *desc;
2658 0 : int ret = 0;
2659 :
2660 0 : WARN_ON(preemptible());
2661 :
2662 0 : desc = irq_get_desc_lock(irq, &flags,
2663 : IRQ_GET_DESC_CHECK_PERCPU);
2664 0 : if (!desc)
2665 : return -EINVAL;
2666 :
2667 0 : if (WARN(!(desc->istate & IRQS_NMI),
2668 : KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
2669 : irq)) {
2670 0 : ret = -EINVAL;
2671 0 : goto out;
2672 : }
2673 :
2674 0 : ret = irq_nmi_setup(desc);
2675 0 : if (ret) {
2676 0 : pr_err("Failed to setup NMI delivery: irq %u\n", irq);
2677 0 : goto out;
2678 : }
2679 :
2680 0 : out:
2681 0 : irq_put_desc_unlock(desc, flags);
2682 0 : return ret;
2683 : }
2684 :
2685 : /**
2686 : * teardown_percpu_nmi - undoes NMI setup of IRQ line
2687 : * @irq: Interrupt line from which CPU local NMI configuration should be
2688 : * removed
2689 : *
2690 : * This call undoes the setup done by prepare_percpu_nmi().
2691 : *
2692 : * IRQ line should not be enabled for the current CPU.
2693 : *
2694 : * As a CPU local operation, this should be called from non-preemptible
2695 : * context.
2696 : */
2697 0 : void teardown_percpu_nmi(unsigned int irq)
2698 : {
2699 0 : unsigned long flags;
2700 0 : struct irq_desc *desc;
2701 :
2702 0 : WARN_ON(preemptible());
2703 :
2704 0 : desc = irq_get_desc_lock(irq, &flags,
2705 : IRQ_GET_DESC_CHECK_PERCPU);
2706 0 : if (!desc)
2707 0 : return;
2708 :
2709 0 : if (WARN_ON(!(desc->istate & IRQS_NMI)))
2710 0 : goto out;
2711 :
2712 0 : irq_nmi_teardown(desc);
2713 0 : out:
2714 0 : irq_put_desc_unlock(desc, flags);
2715 : }
2716 :
2717 0 : int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
2718 : bool *state)
2719 : {
2720 0 : struct irq_chip *chip;
2721 0 : int err = -EINVAL;
2722 :
2723 0 : do {
2724 0 : chip = irq_data_get_irq_chip(data);
2725 0 : if (WARN_ON_ONCE(!chip))
2726 : return -ENODEV;
2727 0 : if (chip->irq_get_irqchip_state)
2728 : break;
2729 : #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2730 0 : data = data->parent_data;
2731 : #else
2732 : data = NULL;
2733 : #endif
2734 0 : } while (data);
2735 :
2736 0 : if (data)
2737 0 : err = chip->irq_get_irqchip_state(data, which, state);
2738 : return err;
2739 : }
2740 :
2741 : /**
2742 : * irq_get_irqchip_state - returns the irqchip state of a interrupt.
2743 : * @irq: Interrupt line that is forwarded to a VM
2744 : * @which: One of IRQCHIP_STATE_* the caller wants to know about
2745 : * @state: a pointer to a boolean where the state is to be storeed
2746 : *
2747 : * This call snapshots the internal irqchip state of an
2748 : * interrupt, returning into @state the bit corresponding to
2749 : * stage @which
2750 : *
2751 : * This function should be called with preemption disabled if the
2752 : * interrupt controller has per-cpu registers.
2753 : */
2754 0 : int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2755 : bool *state)
2756 : {
2757 0 : struct irq_desc *desc;
2758 0 : struct irq_data *data;
2759 0 : unsigned long flags;
2760 0 : int err = -EINVAL;
2761 :
2762 0 : desc = irq_get_desc_buslock(irq, &flags, 0);
2763 0 : if (!desc)
2764 : return err;
2765 :
2766 0 : data = irq_desc_get_irq_data(desc);
2767 :
2768 0 : err = __irq_get_irqchip_state(data, which, state);
2769 :
2770 0 : irq_put_desc_busunlock(desc, flags);
2771 0 : return err;
2772 : }
2773 : EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2774 :
2775 : /**
2776 : * irq_set_irqchip_state - set the state of a forwarded interrupt.
2777 : * @irq: Interrupt line that is forwarded to a VM
2778 : * @which: State to be restored (one of IRQCHIP_STATE_*)
2779 : * @val: Value corresponding to @which
2780 : *
2781 : * This call sets the internal irqchip state of an interrupt,
2782 : * depending on the value of @which.
2783 : *
2784 : * This function should be called with preemption disabled if the
2785 : * interrupt controller has per-cpu registers.
2786 : */
2787 0 : int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2788 : bool val)
2789 : {
2790 0 : struct irq_desc *desc;
2791 0 : struct irq_data *data;
2792 0 : struct irq_chip *chip;
2793 0 : unsigned long flags;
2794 0 : int err = -EINVAL;
2795 :
2796 0 : desc = irq_get_desc_buslock(irq, &flags, 0);
2797 0 : if (!desc)
2798 : return err;
2799 :
2800 0 : data = irq_desc_get_irq_data(desc);
2801 :
2802 0 : do {
2803 0 : chip = irq_data_get_irq_chip(data);
2804 0 : if (WARN_ON_ONCE(!chip)) {
2805 0 : err = -ENODEV;
2806 0 : goto out_unlock;
2807 : }
2808 0 : if (chip->irq_set_irqchip_state)
2809 : break;
2810 : #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2811 0 : data = data->parent_data;
2812 : #else
2813 : data = NULL;
2814 : #endif
2815 0 : } while (data);
2816 :
2817 0 : if (data)
2818 0 : err = chip->irq_set_irqchip_state(data, which, val);
2819 :
2820 0 : out_unlock:
2821 0 : irq_put_desc_busunlock(desc, flags);
2822 0 : return err;
2823 : }
2824 : EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2825 :
2826 : /**
2827 : * irq_has_action - Check whether an interrupt is requested
2828 : * @irq: The linux irq number
2829 : *
2830 : * Returns: A snapshot of the current state
2831 : */
2832 0 : bool irq_has_action(unsigned int irq)
2833 : {
2834 0 : bool res;
2835 :
2836 0 : rcu_read_lock();
2837 0 : res = irq_desc_has_action(irq_to_desc(irq));
2838 0 : rcu_read_unlock();
2839 0 : return res;
2840 : }
2841 : EXPORT_SYMBOL_GPL(irq_has_action);
2842 :
2843 : /**
2844 : * irq_check_status_bit - Check whether bits in the irq descriptor status are set
2845 : * @irq: The linux irq number
2846 : * @bitmask: The bitmask to evaluate
2847 : *
2848 : * Returns: True if one of the bits in @bitmask is set
2849 : */
2850 0 : bool irq_check_status_bit(unsigned int irq, unsigned int bitmask)
2851 : {
2852 0 : struct irq_desc *desc;
2853 0 : bool res = false;
2854 :
2855 0 : rcu_read_lock();
2856 0 : desc = irq_to_desc(irq);
2857 0 : if (desc)
2858 0 : res = !!(desc->status_use_accessors & bitmask);
2859 0 : rcu_read_unlock();
2860 0 : return res;
2861 : }
2862 : EXPORT_SYMBOL_GPL(irq_check_status_bit);
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