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Linux/kernel/irq/manage.c

  1 /*
  2  * linux/kernel/irq/manage.c
  3  *
  4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
  5  * Copyright (C) 2005-2006 Thomas Gleixner
  6  *
  7  * This file contains driver APIs to the irq subsystem.
  8  */
  9 
 10 #define pr_fmt(fmt) "genirq: " fmt
 11 
 12 #include <linux/irq.h>
 13 #include <linux/kthread.h>
 14 #include <linux/module.h>
 15 #include <linux/random.h>
 16 #include <linux/interrupt.h>
 17 #include <linux/slab.h>
 18 #include <linux/sched.h>
 19 #include <linux/sched/rt.h>
 20 #include <linux/task_work.h>
 21 
 22 #include "internals.h"
 23 
 24 #ifdef CONFIG_IRQ_FORCED_THREADING
 25 __read_mostly bool force_irqthreads;
 26 
 27 static int __init setup_forced_irqthreads(char *arg)
 28 {
 29         force_irqthreads = true;
 30         return 0;
 31 }
 32 early_param("threadirqs", setup_forced_irqthreads);
 33 #endif
 34 
 35 static void __synchronize_hardirq(struct irq_desc *desc)
 36 {
 37         bool inprogress;
 38 
 39         do {
 40                 unsigned long flags;
 41 
 42                 /*
 43                  * Wait until we're out of the critical section.  This might
 44                  * give the wrong answer due to the lack of memory barriers.
 45                  */
 46                 while (irqd_irq_inprogress(&desc->irq_data))
 47                         cpu_relax();
 48 
 49                 /* Ok, that indicated we're done: double-check carefully. */
 50                 raw_spin_lock_irqsave(&desc->lock, flags);
 51                 inprogress = irqd_irq_inprogress(&desc->irq_data);
 52                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 53 
 54                 /* Oops, that failed? */
 55         } while (inprogress);
 56 }
 57 
 58 /**
 59  *      synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
 60  *      @irq: interrupt number to wait for
 61  *
 62  *      This function waits for any pending hard IRQ handlers for this
 63  *      interrupt to complete before returning. If you use this
 64  *      function while holding a resource the IRQ handler may need you
 65  *      will deadlock. It does not take associated threaded handlers
 66  *      into account.
 67  *
 68  *      Do not use this for shutdown scenarios where you must be sure
 69  *      that all parts (hardirq and threaded handler) have completed.
 70  *
 71  *      Returns: false if a threaded handler is active.
 72  *
 73  *      This function may be called - with care - from IRQ context.
 74  */
 75 bool synchronize_hardirq(unsigned int irq)
 76 {
 77         struct irq_desc *desc = irq_to_desc(irq);
 78 
 79         if (desc) {
 80                 __synchronize_hardirq(desc);
 81                 return !atomic_read(&desc->threads_active);
 82         }
 83 
 84         return true;
 85 }
 86 EXPORT_SYMBOL(synchronize_hardirq);
 87 
 88 /**
 89  *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
 90  *      @irq: interrupt number to wait for
 91  *
 92  *      This function waits for any pending IRQ handlers for this interrupt
 93  *      to complete before returning. If you use this function while
 94  *      holding a resource the IRQ handler may need you will deadlock.
 95  *
 96  *      This function may be called - with care - from IRQ context.
 97  */
 98 void synchronize_irq(unsigned int irq)
 99 {
100         struct irq_desc *desc = irq_to_desc(irq);
101 
102         if (desc) {
103                 __synchronize_hardirq(desc);
104                 /*
105                  * We made sure that no hardirq handler is
106                  * running. Now verify that no threaded handlers are
107                  * active.
108                  */
109                 wait_event(desc->wait_for_threads,
110                            !atomic_read(&desc->threads_active));
111         }
112 }
113 EXPORT_SYMBOL(synchronize_irq);
114 
115 #ifdef CONFIG_SMP
116 cpumask_var_t irq_default_affinity;
117 
118 static bool __irq_can_set_affinity(struct irq_desc *desc)
119 {
120         if (!desc || !irqd_can_balance(&desc->irq_data) ||
121             !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
122                 return false;
123         return true;
124 }
125 
126 /**
127  *      irq_can_set_affinity - Check if the affinity of a given irq can be set
128  *      @irq:           Interrupt to check
129  *
130  */
131 int irq_can_set_affinity(unsigned int irq)
132 {
133         return __irq_can_set_affinity(irq_to_desc(irq));
134 }
135 
136 /**
137  * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
138  * @irq:        Interrupt to check
139  *
140  * Like irq_can_set_affinity() above, but additionally checks for the
141  * AFFINITY_MANAGED flag.
142  */
143 bool irq_can_set_affinity_usr(unsigned int irq)
144 {
145         struct irq_desc *desc = irq_to_desc(irq);
146 
147         return __irq_can_set_affinity(desc) &&
148                 !irqd_affinity_is_managed(&desc->irq_data);
149 }
150 
151 /**
152  *      irq_set_thread_affinity - Notify irq threads to adjust affinity
153  *      @desc:          irq descriptor which has affitnity changed
154  *
155  *      We just set IRQTF_AFFINITY and delegate the affinity setting
156  *      to the interrupt thread itself. We can not call
157  *      set_cpus_allowed_ptr() here as we hold desc->lock and this
158  *      code can be called from hard interrupt context.
159  */
160 void irq_set_thread_affinity(struct irq_desc *desc)
161 {
162         struct irqaction *action;
163 
164         for_each_action_of_desc(desc, action)
165                 if (action->thread)
166                         set_bit(IRQTF_AFFINITY, &action->thread_flags);
167 }
168 
169 #ifdef CONFIG_GENERIC_PENDING_IRQ
170 static inline bool irq_can_move_pcntxt(struct irq_data *data)
171 {
172         return irqd_can_move_in_process_context(data);
173 }
174 static inline bool irq_move_pending(struct irq_data *data)
175 {
176         return irqd_is_setaffinity_pending(data);
177 }
178 static inline void
179 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
180 {
181         cpumask_copy(desc->pending_mask, mask);
182 }
183 static inline void
184 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
185 {
186         cpumask_copy(mask, desc->pending_mask);
187 }
188 #else
189 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
190 static inline bool irq_move_pending(struct irq_data *data) { return false; }
191 static inline void
192 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
193 static inline void
194 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
195 #endif
196 
197 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
198                         bool force)
199 {
200         struct irq_desc *desc = irq_data_to_desc(data);
201         struct irq_chip *chip = irq_data_get_irq_chip(data);
202         int ret;
203 
204         ret = chip->irq_set_affinity(data, mask, force);
205         switch (ret) {
206         case IRQ_SET_MASK_OK:
207         case IRQ_SET_MASK_OK_DONE:
208                 cpumask_copy(desc->irq_common_data.affinity, mask);
209         case IRQ_SET_MASK_OK_NOCOPY:
210                 irq_set_thread_affinity(desc);
211                 ret = 0;
212         }
213 
214         return ret;
215 }
216 
217 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
218                             bool force)
219 {
220         struct irq_chip *chip = irq_data_get_irq_chip(data);
221         struct irq_desc *desc = irq_data_to_desc(data);
222         int ret = 0;
223 
224         if (!chip || !chip->irq_set_affinity)
225                 return -EINVAL;
226 
227         if (irq_can_move_pcntxt(data)) {
228                 ret = irq_do_set_affinity(data, mask, force);
229         } else {
230                 irqd_set_move_pending(data);
231                 irq_copy_pending(desc, mask);
232         }
233 
234         if (desc->affinity_notify) {
235                 kref_get(&desc->affinity_notify->kref);
236                 schedule_work(&desc->affinity_notify->work);
237         }
238         irqd_set(data, IRQD_AFFINITY_SET);
239 
240         return ret;
241 }
242 
243 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
244 {
245         struct irq_desc *desc = irq_to_desc(irq);
246         unsigned long flags;
247         int ret;
248 
249         if (!desc)
250                 return -EINVAL;
251 
252         raw_spin_lock_irqsave(&desc->lock, flags);
253         ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
254         raw_spin_unlock_irqrestore(&desc->lock, flags);
255         return ret;
256 }
257 
258 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
259 {
260         unsigned long flags;
261         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
262 
263         if (!desc)
264                 return -EINVAL;
265         desc->affinity_hint = m;
266         irq_put_desc_unlock(desc, flags);
267         /* set the initial affinity to prevent every interrupt being on CPU0 */
268         if (m)
269                 __irq_set_affinity(irq, m, false);
270         return 0;
271 }
272 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
273 
274 static void irq_affinity_notify(struct work_struct *work)
275 {
276         struct irq_affinity_notify *notify =
277                 container_of(work, struct irq_affinity_notify, work);
278         struct irq_desc *desc = irq_to_desc(notify->irq);
279         cpumask_var_t cpumask;
280         unsigned long flags;
281 
282         if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
283                 goto out;
284 
285         raw_spin_lock_irqsave(&desc->lock, flags);
286         if (irq_move_pending(&desc->irq_data))
287                 irq_get_pending(cpumask, desc);
288         else
289                 cpumask_copy(cpumask, desc->irq_common_data.affinity);
290         raw_spin_unlock_irqrestore(&desc->lock, flags);
291 
292         notify->notify(notify, cpumask);
293 
294         free_cpumask_var(cpumask);
295 out:
296         kref_put(&notify->kref, notify->release);
297 }
298 
299 /**
300  *      irq_set_affinity_notifier - control notification of IRQ affinity changes
301  *      @irq:           Interrupt for which to enable/disable notification
302  *      @notify:        Context for notification, or %NULL to disable
303  *                      notification.  Function pointers must be initialised;
304  *                      the other fields will be initialised by this function.
305  *
306  *      Must be called in process context.  Notification may only be enabled
307  *      after the IRQ is allocated and must be disabled before the IRQ is
308  *      freed using free_irq().
309  */
310 int
311 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
312 {
313         struct irq_desc *desc = irq_to_desc(irq);
314         struct irq_affinity_notify *old_notify;
315         unsigned long flags;
316 
317         /* The release function is promised process context */
318         might_sleep();
319 
320         if (!desc)
321                 return -EINVAL;
322 
323         /* Complete initialisation of *notify */
324         if (notify) {
325                 notify->irq = irq;
326                 kref_init(&notify->kref);
327                 INIT_WORK(&notify->work, irq_affinity_notify);
328         }
329 
330         raw_spin_lock_irqsave(&desc->lock, flags);
331         old_notify = desc->affinity_notify;
332         desc->affinity_notify = notify;
333         raw_spin_unlock_irqrestore(&desc->lock, flags);
334 
335         if (old_notify)
336                 kref_put(&old_notify->kref, old_notify->release);
337 
338         return 0;
339 }
340 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
341 
342 #ifndef CONFIG_AUTO_IRQ_AFFINITY
343 /*
344  * Generic version of the affinity autoselector.
345  */
346 static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
347 {
348         struct cpumask *set = irq_default_affinity;
349         int node = irq_desc_get_node(desc);
350 
351         /* Excludes PER_CPU and NO_BALANCE interrupts */
352         if (!__irq_can_set_affinity(desc))
353                 return 0;
354 
355         /*
356          * Preserve the managed affinity setting and an userspace affinity
357          * setup, but make sure that one of the targets is online.
358          */
359         if (irqd_affinity_is_managed(&desc->irq_data) ||
360             irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
361                 if (cpumask_intersects(desc->irq_common_data.affinity,
362                                        cpu_online_mask))
363                         set = desc->irq_common_data.affinity;
364                 else
365                         irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
366         }
367 
368         cpumask_and(mask, cpu_online_mask, set);
369         if (node != NUMA_NO_NODE) {
370                 const struct cpumask *nodemask = cpumask_of_node(node);
371 
372                 /* make sure at least one of the cpus in nodemask is online */
373                 if (cpumask_intersects(mask, nodemask))
374                         cpumask_and(mask, mask, nodemask);
375         }
376         irq_do_set_affinity(&desc->irq_data, mask, false);
377         return 0;
378 }
379 #else
380 /* Wrapper for ALPHA specific affinity selector magic */
381 static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
382 {
383         return irq_select_affinity(irq_desc_get_irq(d));
384 }
385 #endif
386 
387 /*
388  * Called when affinity is set via /proc/irq
389  */
390 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
391 {
392         struct irq_desc *desc = irq_to_desc(irq);
393         unsigned long flags;
394         int ret;
395 
396         raw_spin_lock_irqsave(&desc->lock, flags);
397         ret = setup_affinity(desc, mask);
398         raw_spin_unlock_irqrestore(&desc->lock, flags);
399         return ret;
400 }
401 
402 #else
403 static inline int
404 setup_affinity(struct irq_desc *desc, struct cpumask *mask)
405 {
406         return 0;
407 }
408 #endif
409 
410 /**
411  *      irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
412  *      @irq: interrupt number to set affinity
413  *      @vcpu_info: vCPU specific data
414  *
415  *      This function uses the vCPU specific data to set the vCPU
416  *      affinity for an irq. The vCPU specific data is passed from
417  *      outside, such as KVM. One example code path is as below:
418  *      KVM -> IOMMU -> irq_set_vcpu_affinity().
419  */
420 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
421 {
422         unsigned long flags;
423         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
424         struct irq_data *data;
425         struct irq_chip *chip;
426         int ret = -ENOSYS;
427 
428         if (!desc)
429                 return -EINVAL;
430 
431         data = irq_desc_get_irq_data(desc);
432         chip = irq_data_get_irq_chip(data);
433         if (chip && chip->irq_set_vcpu_affinity)
434                 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
435         irq_put_desc_unlock(desc, flags);
436 
437         return ret;
438 }
439 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
440 
441 void __disable_irq(struct irq_desc *desc)
442 {
443         if (!desc->depth++)
444                 irq_disable(desc);
445 }
446 
447 static int __disable_irq_nosync(unsigned int irq)
448 {
449         unsigned long flags;
450         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
451 
452         if (!desc)
453                 return -EINVAL;
454         __disable_irq(desc);
455         irq_put_desc_busunlock(desc, flags);
456         return 0;
457 }
458 
459 /**
460  *      disable_irq_nosync - disable an irq without waiting
461  *      @irq: Interrupt to disable
462  *
463  *      Disable the selected interrupt line.  Disables and Enables are
464  *      nested.
465  *      Unlike disable_irq(), this function does not ensure existing
466  *      instances of the IRQ handler have completed before returning.
467  *
468  *      This function may be called from IRQ context.
469  */
470 void disable_irq_nosync(unsigned int irq)
471 {
472         __disable_irq_nosync(irq);
473 }
474 EXPORT_SYMBOL(disable_irq_nosync);
475 
476 /**
477  *      disable_irq - disable an irq and wait for completion
478  *      @irq: Interrupt to disable
479  *
480  *      Disable the selected interrupt line.  Enables and Disables are
481  *      nested.
482  *      This function waits for any pending IRQ handlers for this interrupt
483  *      to complete before returning. If you use this function while
484  *      holding a resource the IRQ handler may need you will deadlock.
485  *
486  *      This function may be called - with care - from IRQ context.
487  */
488 void disable_irq(unsigned int irq)
489 {
490         if (!__disable_irq_nosync(irq))
491                 synchronize_irq(irq);
492 }
493 EXPORT_SYMBOL(disable_irq);
494 
495 /**
496  *      disable_hardirq - disables an irq and waits for hardirq completion
497  *      @irq: Interrupt to disable
498  *
499  *      Disable the selected interrupt line.  Enables and Disables are
500  *      nested.
501  *      This function waits for any pending hard IRQ handlers for this
502  *      interrupt to complete before returning. If you use this function while
503  *      holding a resource the hard IRQ handler may need you will deadlock.
504  *
505  *      When used to optimistically disable an interrupt from atomic context
506  *      the return value must be checked.
507  *
508  *      Returns: false if a threaded handler is active.
509  *
510  *      This function may be called - with care - from IRQ context.
511  */
512 bool disable_hardirq(unsigned int irq)
513 {
514         if (!__disable_irq_nosync(irq))
515                 return synchronize_hardirq(irq);
516 
517         return false;
518 }
519 EXPORT_SYMBOL_GPL(disable_hardirq);
520 
521 void __enable_irq(struct irq_desc *desc)
522 {
523         switch (desc->depth) {
524         case 0:
525  err_out:
526                 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
527                      irq_desc_get_irq(desc));
528                 break;
529         case 1: {
530                 if (desc->istate & IRQS_SUSPENDED)
531                         goto err_out;
532                 /* Prevent probing on this irq: */
533                 irq_settings_set_noprobe(desc);
534                 irq_enable(desc);
535                 check_irq_resend(desc);
536                 /* fall-through */
537         }
538         default:
539                 desc->depth--;
540         }
541 }
542 
543 /**
544  *      enable_irq - enable handling of an irq
545  *      @irq: Interrupt to enable
546  *
547  *      Undoes the effect of one call to disable_irq().  If this
548  *      matches the last disable, processing of interrupts on this
549  *      IRQ line is re-enabled.
550  *
551  *      This function may be called from IRQ context only when
552  *      desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
553  */
554 void enable_irq(unsigned int irq)
555 {
556         unsigned long flags;
557         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
558 
559         if (!desc)
560                 return;
561         if (WARN(!desc->irq_data.chip,
562                  KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
563                 goto out;
564 
565         __enable_irq(desc);
566 out:
567         irq_put_desc_busunlock(desc, flags);
568 }
569 EXPORT_SYMBOL(enable_irq);
570 
571 static int set_irq_wake_real(unsigned int irq, unsigned int on)
572 {
573         struct irq_desc *desc = irq_to_desc(irq);
574         int ret = -ENXIO;
575 
576         if (irq_desc_get_chip(desc)->flags &  IRQCHIP_SKIP_SET_WAKE)
577                 return 0;
578 
579         if (desc->irq_data.chip->irq_set_wake)
580                 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
581 
582         return ret;
583 }
584 
585 /**
586  *      irq_set_irq_wake - control irq power management wakeup
587  *      @irq:   interrupt to control
588  *      @on:    enable/disable power management wakeup
589  *
590  *      Enable/disable power management wakeup mode, which is
591  *      disabled by default.  Enables and disables must match,
592  *      just as they match for non-wakeup mode support.
593  *
594  *      Wakeup mode lets this IRQ wake the system from sleep
595  *      states like "suspend to RAM".
596  */
597 int irq_set_irq_wake(unsigned int irq, unsigned int on)
598 {
599         unsigned long flags;
600         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
601         int ret = 0;
602 
603         if (!desc)
604                 return -EINVAL;
605 
606         /* wakeup-capable irqs can be shared between drivers that
607          * don't need to have the same sleep mode behaviors.
608          */
609         if (on) {
610                 if (desc->wake_depth++ == 0) {
611                         ret = set_irq_wake_real(irq, on);
612                         if (ret)
613                                 desc->wake_depth = 0;
614                         else
615                                 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
616                 }
617         } else {
618                 if (desc->wake_depth == 0) {
619                         WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
620                 } else if (--desc->wake_depth == 0) {
621                         ret = set_irq_wake_real(irq, on);
622                         if (ret)
623                                 desc->wake_depth = 1;
624                         else
625                                 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
626                 }
627         }
628         irq_put_desc_busunlock(desc, flags);
629         return ret;
630 }
631 EXPORT_SYMBOL(irq_set_irq_wake);
632 
633 /*
634  * Internal function that tells the architecture code whether a
635  * particular irq has been exclusively allocated or is available
636  * for driver use.
637  */
638 int can_request_irq(unsigned int irq, unsigned long irqflags)
639 {
640         unsigned long flags;
641         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
642         int canrequest = 0;
643 
644         if (!desc)
645                 return 0;
646 
647         if (irq_settings_can_request(desc)) {
648                 if (!desc->action ||
649                     irqflags & desc->action->flags & IRQF_SHARED)
650                         canrequest = 1;
651         }
652         irq_put_desc_unlock(desc, flags);
653         return canrequest;
654 }
655 
656 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
657 {
658         struct irq_chip *chip = desc->irq_data.chip;
659         int ret, unmask = 0;
660 
661         if (!chip || !chip->irq_set_type) {
662                 /*
663                  * IRQF_TRIGGER_* but the PIC does not support multiple
664                  * flow-types?
665                  */
666                 pr_debug("No set_type function for IRQ %d (%s)\n",
667                          irq_desc_get_irq(desc),
668                          chip ? (chip->name ? : "unknown") : "unknown");
669                 return 0;
670         }
671 
672         flags &= IRQ_TYPE_SENSE_MASK;
673 
674         if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
675                 if (!irqd_irq_masked(&desc->irq_data))
676                         mask_irq(desc);
677                 if (!irqd_irq_disabled(&desc->irq_data))
678                         unmask = 1;
679         }
680 
681         /* caller masked out all except trigger mode flags */
682         ret = chip->irq_set_type(&desc->irq_data, flags);
683 
684         switch (ret) {
685         case IRQ_SET_MASK_OK:
686         case IRQ_SET_MASK_OK_DONE:
687                 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
688                 irqd_set(&desc->irq_data, flags);
689 
690         case IRQ_SET_MASK_OK_NOCOPY:
691                 flags = irqd_get_trigger_type(&desc->irq_data);
692                 irq_settings_set_trigger_mask(desc, flags);
693                 irqd_clear(&desc->irq_data, IRQD_LEVEL);
694                 irq_settings_clr_level(desc);
695                 if (flags & IRQ_TYPE_LEVEL_MASK) {
696                         irq_settings_set_level(desc);
697                         irqd_set(&desc->irq_data, IRQD_LEVEL);
698                 }
699 
700                 ret = 0;
701                 break;
702         default:
703                 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
704                        flags, irq_desc_get_irq(desc), chip->irq_set_type);
705         }
706         if (unmask)
707                 unmask_irq(desc);
708         return ret;
709 }
710 
711 #ifdef CONFIG_HARDIRQS_SW_RESEND
712 int irq_set_parent(int irq, int parent_irq)
713 {
714         unsigned long flags;
715         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
716 
717         if (!desc)
718                 return -EINVAL;
719 
720         desc->parent_irq = parent_irq;
721 
722         irq_put_desc_unlock(desc, flags);
723         return 0;
724 }
725 #endif
726 
727 /*
728  * Default primary interrupt handler for threaded interrupts. Is
729  * assigned as primary handler when request_threaded_irq is called
730  * with handler == NULL. Useful for oneshot interrupts.
731  */
732 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
733 {
734         return IRQ_WAKE_THREAD;
735 }
736 
737 /*
738  * Primary handler for nested threaded interrupts. Should never be
739  * called.
740  */
741 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
742 {
743         WARN(1, "Primary handler called for nested irq %d\n", irq);
744         return IRQ_NONE;
745 }
746 
747 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
748 {
749         WARN(1, "Secondary action handler called for irq %d\n", irq);
750         return IRQ_NONE;
751 }
752 
753 static int irq_wait_for_interrupt(struct irqaction *action)
754 {
755         set_current_state(TASK_INTERRUPTIBLE);
756 
757         while (!kthread_should_stop()) {
758 
759                 if (test_and_clear_bit(IRQTF_RUNTHREAD,
760                                        &action->thread_flags)) {
761                         __set_current_state(TASK_RUNNING);
762                         return 0;
763                 }
764                 schedule();
765                 set_current_state(TASK_INTERRUPTIBLE);
766         }
767         __set_current_state(TASK_RUNNING);
768         return -1;
769 }
770 
771 /*
772  * Oneshot interrupts keep the irq line masked until the threaded
773  * handler finished. unmask if the interrupt has not been disabled and
774  * is marked MASKED.
775  */
776 static void irq_finalize_oneshot(struct irq_desc *desc,
777                                  struct irqaction *action)
778 {
779         if (!(desc->istate & IRQS_ONESHOT) ||
780             action->handler == irq_forced_secondary_handler)
781                 return;
782 again:
783         chip_bus_lock(desc);
784         raw_spin_lock_irq(&desc->lock);
785 
786         /*
787          * Implausible though it may be we need to protect us against
788          * the following scenario:
789          *
790          * The thread is faster done than the hard interrupt handler
791          * on the other CPU. If we unmask the irq line then the
792          * interrupt can come in again and masks the line, leaves due
793          * to IRQS_INPROGRESS and the irq line is masked forever.
794          *
795          * This also serializes the state of shared oneshot handlers
796          * versus "desc->threads_onehsot |= action->thread_mask;" in
797          * irq_wake_thread(). See the comment there which explains the
798          * serialization.
799          */
800         if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
801                 raw_spin_unlock_irq(&desc->lock);
802                 chip_bus_sync_unlock(desc);
803                 cpu_relax();
804                 goto again;
805         }
806 
807         /*
808          * Now check again, whether the thread should run. Otherwise
809          * we would clear the threads_oneshot bit of this thread which
810          * was just set.
811          */
812         if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
813                 goto out_unlock;
814 
815         desc->threads_oneshot &= ~action->thread_mask;
816 
817         if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
818             irqd_irq_masked(&desc->irq_data))
819                 unmask_threaded_irq(desc);
820 
821 out_unlock:
822         raw_spin_unlock_irq(&desc->lock);
823         chip_bus_sync_unlock(desc);
824 }
825 
826 #ifdef CONFIG_SMP
827 /*
828  * Check whether we need to change the affinity of the interrupt thread.
829  */
830 static void
831 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
832 {
833         cpumask_var_t mask;
834         bool valid = true;
835 
836         if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
837                 return;
838 
839         /*
840          * In case we are out of memory we set IRQTF_AFFINITY again and
841          * try again next time
842          */
843         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
844                 set_bit(IRQTF_AFFINITY, &action->thread_flags);
845                 return;
846         }
847 
848         raw_spin_lock_irq(&desc->lock);
849         /*
850          * This code is triggered unconditionally. Check the affinity
851          * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
852          */
853         if (desc->irq_common_data.affinity)
854                 cpumask_copy(mask, desc->irq_common_data.affinity);
855         else
856                 valid = false;
857         raw_spin_unlock_irq(&desc->lock);
858 
859         if (valid)
860                 set_cpus_allowed_ptr(current, mask);
861         free_cpumask_var(mask);
862 }
863 #else
864 static inline void
865 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
866 #endif
867 
868 /*
869  * Interrupts which are not explicitely requested as threaded
870  * interrupts rely on the implicit bh/preempt disable of the hard irq
871  * context. So we need to disable bh here to avoid deadlocks and other
872  * side effects.
873  */
874 static irqreturn_t
875 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
876 {
877         irqreturn_t ret;
878 
879         local_bh_disable();
880         ret = action->thread_fn(action->irq, action->dev_id);
881         irq_finalize_oneshot(desc, action);
882         local_bh_enable();
883         return ret;
884 }
885 
886 /*
887  * Interrupts explicitly requested as threaded interrupts want to be
888  * preemtible - many of them need to sleep and wait for slow busses to
889  * complete.
890  */
891 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
892                 struct irqaction *action)
893 {
894         irqreturn_t ret;
895 
896         ret = action->thread_fn(action->irq, action->dev_id);
897         irq_finalize_oneshot(desc, action);
898         return ret;
899 }
900 
901 static void wake_threads_waitq(struct irq_desc *desc)
902 {
903         if (atomic_dec_and_test(&desc->threads_active))
904                 wake_up(&desc->wait_for_threads);
905 }
906 
907 static void irq_thread_dtor(struct callback_head *unused)
908 {
909         struct task_struct *tsk = current;
910         struct irq_desc *desc;
911         struct irqaction *action;
912 
913         if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
914                 return;
915 
916         action = kthread_data(tsk);
917 
918         pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
919                tsk->comm, tsk->pid, action->irq);
920 
921 
922         desc = irq_to_desc(action->irq);
923         /*
924          * If IRQTF_RUNTHREAD is set, we need to decrement
925          * desc->threads_active and wake possible waiters.
926          */
927         if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
928                 wake_threads_waitq(desc);
929 
930         /* Prevent a stale desc->threads_oneshot */
931         irq_finalize_oneshot(desc, action);
932 }
933 
934 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
935 {
936         struct irqaction *secondary = action->secondary;
937 
938         if (WARN_ON_ONCE(!secondary))
939                 return;
940 
941         raw_spin_lock_irq(&desc->lock);
942         __irq_wake_thread(desc, secondary);
943         raw_spin_unlock_irq(&desc->lock);
944 }
945 
946 /*
947  * Interrupt handler thread
948  */
949 static int irq_thread(void *data)
950 {
951         struct callback_head on_exit_work;
952         struct irqaction *action = data;
953         struct irq_desc *desc = irq_to_desc(action->irq);
954         irqreturn_t (*handler_fn)(struct irq_desc *desc,
955                         struct irqaction *action);
956 
957         if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
958                                         &action->thread_flags))
959                 handler_fn = irq_forced_thread_fn;
960         else
961                 handler_fn = irq_thread_fn;
962 
963         init_task_work(&on_exit_work, irq_thread_dtor);
964         task_work_add(current, &on_exit_work, false);
965 
966         irq_thread_check_affinity(desc, action);
967 
968         while (!irq_wait_for_interrupt(action)) {
969                 irqreturn_t action_ret;
970 
971                 irq_thread_check_affinity(desc, action);
972 
973                 action_ret = handler_fn(desc, action);
974                 if (action_ret == IRQ_HANDLED)
975                         atomic_inc(&desc->threads_handled);
976                 if (action_ret == IRQ_WAKE_THREAD)
977                         irq_wake_secondary(desc, action);
978 
979                 wake_threads_waitq(desc);
980         }
981 
982         /*
983          * This is the regular exit path. __free_irq() is stopping the
984          * thread via kthread_stop() after calling
985          * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
986          * oneshot mask bit can be set. We cannot verify that as we
987          * cannot touch the oneshot mask at this point anymore as
988          * __setup_irq() might have given out currents thread_mask
989          * again.
990          */
991         task_work_cancel(current, irq_thread_dtor);
992         return 0;
993 }
994 
995 /**
996  *      irq_wake_thread - wake the irq thread for the action identified by dev_id
997  *      @irq:           Interrupt line
998  *      @dev_id:        Device identity for which the thread should be woken
999  *
1000  */
1001 void irq_wake_thread(unsigned int irq, void *dev_id)
1002 {
1003         struct irq_desc *desc = irq_to_desc(irq);
1004         struct irqaction *action;
1005         unsigned long flags;
1006 
1007         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1008                 return;
1009 
1010         raw_spin_lock_irqsave(&desc->lock, flags);
1011         for_each_action_of_desc(desc, action) {
1012                 if (action->dev_id == dev_id) {
1013                         if (action->thread)
1014                                 __irq_wake_thread(desc, action);
1015                         break;
1016                 }
1017         }
1018         raw_spin_unlock_irqrestore(&desc->lock, flags);
1019 }
1020 EXPORT_SYMBOL_GPL(irq_wake_thread);
1021 
1022 static int irq_setup_forced_threading(struct irqaction *new)
1023 {
1024         if (!force_irqthreads)
1025                 return 0;
1026         if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1027                 return 0;
1028 
1029         new->flags |= IRQF_ONESHOT;
1030 
1031         /*
1032          * Handle the case where we have a real primary handler and a
1033          * thread handler. We force thread them as well by creating a
1034          * secondary action.
1035          */
1036         if (new->handler != irq_default_primary_handler && new->thread_fn) {
1037                 /* Allocate the secondary action */
1038                 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1039                 if (!new->secondary)
1040                         return -ENOMEM;
1041                 new->secondary->handler = irq_forced_secondary_handler;
1042                 new->secondary->thread_fn = new->thread_fn;
1043                 new->secondary->dev_id = new->dev_id;
1044                 new->secondary->irq = new->irq;
1045                 new->secondary->name = new->name;
1046         }
1047         /* Deal with the primary handler */
1048         set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1049         new->thread_fn = new->handler;
1050         new->handler = irq_default_primary_handler;
1051         return 0;
1052 }
1053 
1054 static int irq_request_resources(struct irq_desc *desc)
1055 {
1056         struct irq_data *d = &desc->irq_data;
1057         struct irq_chip *c = d->chip;
1058 
1059         return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1060 }
1061 
1062 static void irq_release_resources(struct irq_desc *desc)
1063 {
1064         struct irq_data *d = &desc->irq_data;
1065         struct irq_chip *c = d->chip;
1066 
1067         if (c->irq_release_resources)
1068                 c->irq_release_resources(d);
1069 }
1070 
1071 static int
1072 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1073 {
1074         struct task_struct *t;
1075         struct sched_param param = {
1076                 .sched_priority = MAX_USER_RT_PRIO/2,
1077         };
1078 
1079         if (!secondary) {
1080                 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1081                                    new->name);
1082         } else {
1083                 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1084                                    new->name);
1085                 param.sched_priority -= 1;
1086         }
1087 
1088         if (IS_ERR(t))
1089                 return PTR_ERR(t);
1090 
1091         sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
1092 
1093         /*
1094          * We keep the reference to the task struct even if
1095          * the thread dies to avoid that the interrupt code
1096          * references an already freed task_struct.
1097          */
1098         get_task_struct(t);
1099         new->thread = t;
1100         /*
1101          * Tell the thread to set its affinity. This is
1102          * important for shared interrupt handlers as we do
1103          * not invoke setup_affinity() for the secondary
1104          * handlers as everything is already set up. Even for
1105          * interrupts marked with IRQF_NO_BALANCE this is
1106          * correct as we want the thread to move to the cpu(s)
1107          * on which the requesting code placed the interrupt.
1108          */
1109         set_bit(IRQTF_AFFINITY, &new->thread_flags);
1110         return 0;
1111 }
1112 
1113 /*
1114  * Internal function to register an irqaction - typically used to
1115  * allocate special interrupts that are part of the architecture.
1116  */
1117 static int
1118 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1119 {
1120         struct irqaction *old, **old_ptr;
1121         unsigned long flags, thread_mask = 0;
1122         int ret, nested, shared = 0;
1123         cpumask_var_t mask;
1124 
1125         if (!desc)
1126                 return -EINVAL;
1127 
1128         if (desc->irq_data.chip == &no_irq_chip)
1129                 return -ENOSYS;
1130         if (!try_module_get(desc->owner))
1131                 return -ENODEV;
1132 
1133         new->irq = irq;
1134 
1135         /*
1136          * If the trigger type is not specified by the caller,
1137          * then use the default for this interrupt.
1138          */
1139         if (!(new->flags & IRQF_TRIGGER_MASK))
1140                 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1141 
1142         /*
1143          * Check whether the interrupt nests into another interrupt
1144          * thread.
1145          */
1146         nested = irq_settings_is_nested_thread(desc);
1147         if (nested) {
1148                 if (!new->thread_fn) {
1149                         ret = -EINVAL;
1150                         goto out_mput;
1151                 }
1152                 /*
1153                  * Replace the primary handler which was provided from
1154                  * the driver for non nested interrupt handling by the
1155                  * dummy function which warns when called.
1156                  */
1157                 new->handler = irq_nested_primary_handler;
1158         } else {
1159                 if (irq_settings_can_thread(desc)) {
1160                         ret = irq_setup_forced_threading(new);
1161                         if (ret)
1162                                 goto out_mput;
1163                 }
1164         }
1165 
1166         /*
1167          * Create a handler thread when a thread function is supplied
1168          * and the interrupt does not nest into another interrupt
1169          * thread.
1170          */
1171         if (new->thread_fn && !nested) {
1172                 ret = setup_irq_thread(new, irq, false);
1173                 if (ret)
1174                         goto out_mput;
1175                 if (new->secondary) {
1176                         ret = setup_irq_thread(new->secondary, irq, true);
1177                         if (ret)
1178                                 goto out_thread;
1179                 }
1180         }
1181 
1182         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1183                 ret = -ENOMEM;
1184                 goto out_thread;
1185         }
1186 
1187         /*
1188          * Drivers are often written to work w/o knowledge about the
1189          * underlying irq chip implementation, so a request for a
1190          * threaded irq without a primary hard irq context handler
1191          * requires the ONESHOT flag to be set. Some irq chips like
1192          * MSI based interrupts are per se one shot safe. Check the
1193          * chip flags, so we can avoid the unmask dance at the end of
1194          * the threaded handler for those.
1195          */
1196         if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1197                 new->flags &= ~IRQF_ONESHOT;
1198 
1199         /*
1200          * The following block of code has to be executed atomically
1201          */
1202         raw_spin_lock_irqsave(&desc->lock, flags);
1203         old_ptr = &desc->action;
1204         old = *old_ptr;
1205         if (old) {
1206                 /*
1207                  * Can't share interrupts unless both agree to and are
1208                  * the same type (level, edge, polarity). So both flag
1209                  * fields must have IRQF_SHARED set and the bits which
1210                  * set the trigger type must match. Also all must
1211                  * agree on ONESHOT.
1212                  */
1213                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1214                     ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1215                     ((old->flags ^ new->flags) & IRQF_ONESHOT))
1216                         goto mismatch;
1217 
1218                 /* All handlers must agree on per-cpuness */
1219                 if ((old->flags & IRQF_PERCPU) !=
1220                     (new->flags & IRQF_PERCPU))
1221                         goto mismatch;
1222 
1223                 /* add new interrupt at end of irq queue */
1224                 do {
1225                         /*
1226                          * Or all existing action->thread_mask bits,
1227                          * so we can find the next zero bit for this
1228                          * new action.
1229                          */
1230                         thread_mask |= old->thread_mask;
1231                         old_ptr = &old->next;
1232                         old = *old_ptr;
1233                 } while (old);
1234                 shared = 1;
1235         }
1236 
1237         /*
1238          * Setup the thread mask for this irqaction for ONESHOT. For
1239          * !ONESHOT irqs the thread mask is 0 so we can avoid a
1240          * conditional in irq_wake_thread().
1241          */
1242         if (new->flags & IRQF_ONESHOT) {
1243                 /*
1244                  * Unlikely to have 32 resp 64 irqs sharing one line,
1245                  * but who knows.
1246                  */
1247                 if (thread_mask == ~0UL) {
1248                         ret = -EBUSY;
1249                         goto out_mask;
1250                 }
1251                 /*
1252                  * The thread_mask for the action is or'ed to
1253                  * desc->thread_active to indicate that the
1254                  * IRQF_ONESHOT thread handler has been woken, but not
1255                  * yet finished. The bit is cleared when a thread
1256                  * completes. When all threads of a shared interrupt
1257                  * line have completed desc->threads_active becomes
1258                  * zero and the interrupt line is unmasked. See
1259                  * handle.c:irq_wake_thread() for further information.
1260                  *
1261                  * If no thread is woken by primary (hard irq context)
1262                  * interrupt handlers, then desc->threads_active is
1263                  * also checked for zero to unmask the irq line in the
1264                  * affected hard irq flow handlers
1265                  * (handle_[fasteoi|level]_irq).
1266                  *
1267                  * The new action gets the first zero bit of
1268                  * thread_mask assigned. See the loop above which or's
1269                  * all existing action->thread_mask bits.
1270                  */
1271                 new->thread_mask = 1 << ffz(thread_mask);
1272 
1273         } else if (new->handler == irq_default_primary_handler &&
1274                    !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1275                 /*
1276                  * The interrupt was requested with handler = NULL, so
1277                  * we use the default primary handler for it. But it
1278                  * does not have the oneshot flag set. In combination
1279                  * with level interrupts this is deadly, because the
1280                  * default primary handler just wakes the thread, then
1281                  * the irq lines is reenabled, but the device still
1282                  * has the level irq asserted. Rinse and repeat....
1283                  *
1284                  * While this works for edge type interrupts, we play
1285                  * it safe and reject unconditionally because we can't
1286                  * say for sure which type this interrupt really
1287                  * has. The type flags are unreliable as the
1288                  * underlying chip implementation can override them.
1289                  */
1290                 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1291                        irq);
1292                 ret = -EINVAL;
1293                 goto out_mask;
1294         }
1295 
1296         if (!shared) {
1297                 ret = irq_request_resources(desc);
1298                 if (ret) {
1299                         pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1300                                new->name, irq, desc->irq_data.chip->name);
1301                         goto out_mask;
1302                 }
1303 
1304                 init_waitqueue_head(&desc->wait_for_threads);
1305 
1306                 /* Setup the type (level, edge polarity) if configured: */
1307                 if (new->flags & IRQF_TRIGGER_MASK) {
1308                         ret = __irq_set_trigger(desc,
1309                                                 new->flags & IRQF_TRIGGER_MASK);
1310 
1311                         if (ret)
1312                                 goto out_mask;
1313                 }
1314 
1315                 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1316                                   IRQS_ONESHOT | IRQS_WAITING);
1317                 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1318 
1319                 if (new->flags & IRQF_PERCPU) {
1320                         irqd_set(&desc->irq_data, IRQD_PER_CPU);
1321                         irq_settings_set_per_cpu(desc);
1322                 }
1323 
1324                 if (new->flags & IRQF_ONESHOT)
1325                         desc->istate |= IRQS_ONESHOT;
1326 
1327                 if (irq_settings_can_autoenable(desc))
1328                         irq_startup(desc, true);
1329                 else
1330                         /* Undo nested disables: */
1331                         desc->depth = 1;
1332 
1333                 /* Exclude IRQ from balancing if requested */
1334                 if (new->flags & IRQF_NOBALANCING) {
1335                         irq_settings_set_no_balancing(desc);
1336                         irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1337                 }
1338 
1339                 /* Set default affinity mask once everything is setup */
1340                 setup_affinity(desc, mask);
1341 
1342         } else if (new->flags & IRQF_TRIGGER_MASK) {
1343                 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1344                 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1345 
1346                 if (nmsk != omsk)
1347                         /* hope the handler works with current  trigger mode */
1348                         pr_warn("irq %d uses trigger mode %u; requested %u\n",
1349                                 irq, nmsk, omsk);
1350         }
1351 
1352         *old_ptr = new;
1353 
1354         irq_pm_install_action(desc, new);
1355 
1356         /* Reset broken irq detection when installing new handler */
1357         desc->irq_count = 0;
1358         desc->irqs_unhandled = 0;
1359 
1360         /*
1361          * Check whether we disabled the irq via the spurious handler
1362          * before. Reenable it and give it another chance.
1363          */
1364         if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1365                 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1366                 __enable_irq(desc);
1367         }
1368 
1369         raw_spin_unlock_irqrestore(&desc->lock, flags);
1370 
1371         /*
1372          * Strictly no need to wake it up, but hung_task complains
1373          * when no hard interrupt wakes the thread up.
1374          */
1375         if (new->thread)
1376                 wake_up_process(new->thread);
1377         if (new->secondary)
1378                 wake_up_process(new->secondary->thread);
1379 
1380         register_irq_proc(irq, desc);
1381         new->dir = NULL;
1382         register_handler_proc(irq, new);
1383         free_cpumask_var(mask);
1384 
1385         return 0;
1386 
1387 mismatch:
1388         if (!(new->flags & IRQF_PROBE_SHARED)) {
1389                 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1390                        irq, new->flags, new->name, old->flags, old->name);
1391 #ifdef CONFIG_DEBUG_SHIRQ
1392                 dump_stack();
1393 #endif
1394         }
1395         ret = -EBUSY;
1396 
1397 out_mask:
1398         raw_spin_unlock_irqrestore(&desc->lock, flags);
1399         free_cpumask_var(mask);
1400 
1401 out_thread:
1402         if (new->thread) {
1403                 struct task_struct *t = new->thread;
1404 
1405                 new->thread = NULL;
1406                 kthread_stop(t);
1407                 put_task_struct(t);
1408         }
1409         if (new->secondary && new->secondary->thread) {
1410                 struct task_struct *t = new->secondary->thread;
1411 
1412                 new->secondary->thread = NULL;
1413                 kthread_stop(t);
1414                 put_task_struct(t);
1415         }
1416 out_mput:
1417         module_put(desc->owner);
1418         return ret;
1419 }
1420 
1421 /**
1422  *      setup_irq - setup an interrupt
1423  *      @irq: Interrupt line to setup
1424  *      @act: irqaction for the interrupt
1425  *
1426  * Used to statically setup interrupts in the early boot process.
1427  */
1428 int setup_irq(unsigned int irq, struct irqaction *act)
1429 {
1430         int retval;
1431         struct irq_desc *desc = irq_to_desc(irq);
1432 
1433         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1434                 return -EINVAL;
1435 
1436         retval = irq_chip_pm_get(&desc->irq_data);
1437         if (retval < 0)
1438                 return retval;
1439 
1440         chip_bus_lock(desc);
1441         retval = __setup_irq(irq, desc, act);
1442         chip_bus_sync_unlock(desc);
1443 
1444         if (retval)
1445                 irq_chip_pm_put(&desc->irq_data);
1446 
1447         return retval;
1448 }
1449 EXPORT_SYMBOL_GPL(setup_irq);
1450 
1451 /*
1452  * Internal function to unregister an irqaction - used to free
1453  * regular and special interrupts that are part of the architecture.
1454  */
1455 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1456 {
1457         struct irq_desc *desc = irq_to_desc(irq);
1458         struct irqaction *action, **action_ptr;
1459         unsigned long flags;
1460 
1461         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1462 
1463         if (!desc)
1464                 return NULL;
1465 
1466         chip_bus_lock(desc);
1467         raw_spin_lock_irqsave(&desc->lock, flags);
1468 
1469         /*
1470          * There can be multiple actions per IRQ descriptor, find the right
1471          * one based on the dev_id:
1472          */
1473         action_ptr = &desc->action;
1474         for (;;) {
1475                 action = *action_ptr;
1476 
1477                 if (!action) {
1478                         WARN(1, "Trying to free already-free IRQ %d\n", irq);
1479                         raw_spin_unlock_irqrestore(&desc->lock, flags);
1480                         chip_bus_sync_unlock(desc);
1481                         return NULL;
1482                 }
1483 
1484                 if (action->dev_id == dev_id)
1485                         break;
1486                 action_ptr = &action->next;
1487         }
1488 
1489         /* Found it - now remove it from the list of entries: */
1490         *action_ptr = action->next;
1491 
1492         irq_pm_remove_action(desc, action);
1493 
1494         /* If this was the last handler, shut down the IRQ line: */
1495         if (!desc->action) {
1496                 irq_settings_clr_disable_unlazy(desc);
1497                 irq_shutdown(desc);
1498                 irq_release_resources(desc);
1499         }
1500 
1501 #ifdef CONFIG_SMP
1502         /* make sure affinity_hint is cleaned up */
1503         if (WARN_ON_ONCE(desc->affinity_hint))
1504                 desc->affinity_hint = NULL;
1505 #endif
1506 
1507         raw_spin_unlock_irqrestore(&desc->lock, flags);
1508         chip_bus_sync_unlock(desc);
1509 
1510         unregister_handler_proc(irq, action);
1511 
1512         /* Make sure it's not being used on another CPU: */
1513         synchronize_irq(irq);
1514 
1515 #ifdef CONFIG_DEBUG_SHIRQ
1516         /*
1517          * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1518          * event to happen even now it's being freed, so let's make sure that
1519          * is so by doing an extra call to the handler ....
1520          *
1521          * ( We do this after actually deregistering it, to make sure that a
1522          *   'real' IRQ doesn't run in * parallel with our fake. )
1523          */
1524         if (action->flags & IRQF_SHARED) {
1525                 local_irq_save(flags);
1526                 action->handler(irq, dev_id);
1527                 local_irq_restore(flags);
1528         }
1529 #endif
1530 
1531         if (action->thread) {
1532                 kthread_stop(action->thread);
1533                 put_task_struct(action->thread);
1534                 if (action->secondary && action->secondary->thread) {
1535                         kthread_stop(action->secondary->thread);
1536                         put_task_struct(action->secondary->thread);
1537                 }
1538         }
1539 
1540         irq_chip_pm_put(&desc->irq_data);
1541         module_put(desc->owner);
1542         kfree(action->secondary);
1543         return action;
1544 }
1545 
1546 /**
1547  *      remove_irq - free an interrupt
1548  *      @irq: Interrupt line to free
1549  *      @act: irqaction for the interrupt
1550  *
1551  * Used to remove interrupts statically setup by the early boot process.
1552  */
1553 void remove_irq(unsigned int irq, struct irqaction *act)
1554 {
1555         struct irq_desc *desc = irq_to_desc(irq);
1556 
1557         if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1558             __free_irq(irq, act->dev_id);
1559 }
1560 EXPORT_SYMBOL_GPL(remove_irq);
1561 
1562 /**
1563  *      free_irq - free an interrupt allocated with request_irq
1564  *      @irq: Interrupt line to free
1565  *      @dev_id: Device identity to free
1566  *
1567  *      Remove an interrupt handler. The handler is removed and if the
1568  *      interrupt line is no longer in use by any driver it is disabled.
1569  *      On a shared IRQ the caller must ensure the interrupt is disabled
1570  *      on the card it drives before calling this function. The function
1571  *      does not return until any executing interrupts for this IRQ
1572  *      have completed.
1573  *
1574  *      This function must not be called from interrupt context.
1575  */
1576 void free_irq(unsigned int irq, void *dev_id)
1577 {
1578         struct irq_desc *desc = irq_to_desc(irq);
1579 
1580         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1581                 return;
1582 
1583 #ifdef CONFIG_SMP
1584         if (WARN_ON(desc->affinity_notify))
1585                 desc->affinity_notify = NULL;
1586 #endif
1587 
1588         kfree(__free_irq(irq, dev_id));
1589 }
1590 EXPORT_SYMBOL(free_irq);
1591 
1592 /**
1593  *      request_threaded_irq - allocate an interrupt line
1594  *      @irq: Interrupt line to allocate
1595  *      @handler: Function to be called when the IRQ occurs.
1596  *                Primary handler for threaded interrupts
1597  *                If NULL and thread_fn != NULL the default
1598  *                primary handler is installed
1599  *      @thread_fn: Function called from the irq handler thread
1600  *                  If NULL, no irq thread is created
1601  *      @irqflags: Interrupt type flags
1602  *      @devname: An ascii name for the claiming device
1603  *      @dev_id: A cookie passed back to the handler function
1604  *
1605  *      This call allocates interrupt resources and enables the
1606  *      interrupt line and IRQ handling. From the point this
1607  *      call is made your handler function may be invoked. Since
1608  *      your handler function must clear any interrupt the board
1609  *      raises, you must take care both to initialise your hardware
1610  *      and to set up the interrupt handler in the right order.
1611  *
1612  *      If you want to set up a threaded irq handler for your device
1613  *      then you need to supply @handler and @thread_fn. @handler is
1614  *      still called in hard interrupt context and has to check
1615  *      whether the interrupt originates from the device. If yes it
1616  *      needs to disable the interrupt on the device and return
1617  *      IRQ_WAKE_THREAD which will wake up the handler thread and run
1618  *      @thread_fn. This split handler design is necessary to support
1619  *      shared interrupts.
1620  *
1621  *      Dev_id must be globally unique. Normally the address of the
1622  *      device data structure is used as the cookie. Since the handler
1623  *      receives this value it makes sense to use it.
1624  *
1625  *      If your interrupt is shared you must pass a non NULL dev_id
1626  *      as this is required when freeing the interrupt.
1627  *
1628  *      Flags:
1629  *
1630  *      IRQF_SHARED             Interrupt is shared
1631  *      IRQF_TRIGGER_*          Specify active edge(s) or level
1632  *
1633  */
1634 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1635                          irq_handler_t thread_fn, unsigned long irqflags,
1636                          const char *devname, void *dev_id)
1637 {
1638         struct irqaction *action;
1639         struct irq_desc *desc;
1640         int retval;
1641 
1642         if (irq == IRQ_NOTCONNECTED)
1643                 return -ENOTCONN;
1644 
1645         /*
1646          * Sanity-check: shared interrupts must pass in a real dev-ID,
1647          * otherwise we'll have trouble later trying to figure out
1648          * which interrupt is which (messes up the interrupt freeing
1649          * logic etc).
1650          *
1651          * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1652          * it cannot be set along with IRQF_NO_SUSPEND.
1653          */
1654         if (((irqflags & IRQF_SHARED) && !dev_id) ||
1655             (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1656             ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1657                 return -EINVAL;
1658 
1659         desc = irq_to_desc(irq);
1660         if (!desc)
1661                 return -EINVAL;
1662 
1663         if (!irq_settings_can_request(desc) ||
1664             WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1665                 return -EINVAL;
1666 
1667         if (!handler) {
1668                 if (!thread_fn)
1669                         return -EINVAL;
1670                 handler = irq_default_primary_handler;
1671         }
1672 
1673         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1674         if (!action)
1675                 return -ENOMEM;
1676 
1677         action->handler = handler;
1678         action->thread_fn = thread_fn;
1679         action->flags = irqflags;
1680         action->name = devname;
1681         action->dev_id = dev_id;
1682 
1683         retval = irq_chip_pm_get(&desc->irq_data);
1684         if (retval < 0) {
1685                 kfree(action);
1686                 return retval;
1687         }
1688 
1689         chip_bus_lock(desc);
1690         retval = __setup_irq(irq, desc, action);
1691         chip_bus_sync_unlock(desc);
1692 
1693         if (retval) {
1694                 irq_chip_pm_put(&desc->irq_data);
1695                 kfree(action->secondary);
1696                 kfree(action);
1697         }
1698 
1699 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1700         if (!retval && (irqflags & IRQF_SHARED)) {
1701                 /*
1702                  * It's a shared IRQ -- the driver ought to be prepared for it
1703                  * to happen immediately, so let's make sure....
1704                  * We disable the irq to make sure that a 'real' IRQ doesn't
1705                  * run in parallel with our fake.
1706                  */
1707                 unsigned long flags;
1708 
1709                 disable_irq(irq);
1710                 local_irq_save(flags);
1711 
1712                 handler(irq, dev_id);
1713 
1714                 local_irq_restore(flags);
1715                 enable_irq(irq);
1716         }
1717 #endif
1718         return retval;
1719 }
1720 EXPORT_SYMBOL(request_threaded_irq);
1721 
1722 /**
1723  *      request_any_context_irq - allocate an interrupt line
1724  *      @irq: Interrupt line to allocate
1725  *      @handler: Function to be called when the IRQ occurs.
1726  *                Threaded handler for threaded interrupts.
1727  *      @flags: Interrupt type flags
1728  *      @name: An ascii name for the claiming device
1729  *      @dev_id: A cookie passed back to the handler function
1730  *
1731  *      This call allocates interrupt resources and enables the
1732  *      interrupt line and IRQ handling. It selects either a
1733  *      hardirq or threaded handling method depending on the
1734  *      context.
1735  *
1736  *      On failure, it returns a negative value. On success,
1737  *      it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1738  */
1739 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1740                             unsigned long flags, const char *name, void *dev_id)
1741 {
1742         struct irq_desc *desc;
1743         int ret;
1744 
1745         if (irq == IRQ_NOTCONNECTED)
1746                 return -ENOTCONN;
1747 
1748         desc = irq_to_desc(irq);
1749         if (!desc)
1750                 return -EINVAL;
1751 
1752         if (irq_settings_is_nested_thread(desc)) {
1753                 ret = request_threaded_irq(irq, NULL, handler,
1754                                            flags, name, dev_id);
1755                 return !ret ? IRQC_IS_NESTED : ret;
1756         }
1757 
1758         ret = request_irq(irq, handler, flags, name, dev_id);
1759         return !ret ? IRQC_IS_HARDIRQ : ret;
1760 }
1761 EXPORT_SYMBOL_GPL(request_any_context_irq);
1762 
1763 void enable_percpu_irq(unsigned int irq, unsigned int type)
1764 {
1765         unsigned int cpu = smp_processor_id();
1766         unsigned long flags;
1767         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1768 
1769         if (!desc)
1770                 return;
1771 
1772         /*
1773          * If the trigger type is not specified by the caller, then
1774          * use the default for this interrupt.
1775          */
1776         type &= IRQ_TYPE_SENSE_MASK;
1777         if (type == IRQ_TYPE_NONE)
1778                 type = irqd_get_trigger_type(&desc->irq_data);
1779 
1780         if (type != IRQ_TYPE_NONE) {
1781                 int ret;
1782 
1783                 ret = __irq_set_trigger(desc, type);
1784 
1785                 if (ret) {
1786                         WARN(1, "failed to set type for IRQ%d\n", irq);
1787                         goto out;
1788                 }
1789         }
1790 
1791         irq_percpu_enable(desc, cpu);
1792 out:
1793         irq_put_desc_unlock(desc, flags);
1794 }
1795 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1796 
1797 /**
1798  * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1799  * @irq:        Linux irq number to check for
1800  *
1801  * Must be called from a non migratable context. Returns the enable
1802  * state of a per cpu interrupt on the current cpu.
1803  */
1804 bool irq_percpu_is_enabled(unsigned int irq)
1805 {
1806         unsigned int cpu = smp_processor_id();
1807         struct irq_desc *desc;
1808         unsigned long flags;
1809         bool is_enabled;
1810 
1811         desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1812         if (!desc)
1813                 return false;
1814 
1815         is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1816         irq_put_desc_unlock(desc, flags);
1817 
1818         return is_enabled;
1819 }
1820 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1821 
1822 void disable_percpu_irq(unsigned int irq)
1823 {
1824         unsigned int cpu = smp_processor_id();
1825         unsigned long flags;
1826         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1827 
1828         if (!desc)
1829                 return;
1830 
1831         irq_percpu_disable(desc, cpu);
1832         irq_put_desc_unlock(desc, flags);
1833 }
1834 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1835 
1836 /*
1837  * Internal function to unregister a percpu irqaction.
1838  */
1839 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1840 {
1841         struct irq_desc *desc = irq_to_desc(irq);
1842         struct irqaction *action;
1843         unsigned long flags;
1844 
1845         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1846 
1847         if (!desc)
1848                 return NULL;
1849 
1850         raw_spin_lock_irqsave(&desc->lock, flags);
1851 
1852         action = desc->action;
1853         if (!action || action->percpu_dev_id != dev_id) {
1854                 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1855                 goto bad;
1856         }
1857 
1858         if (!cpumask_empty(desc->percpu_enabled)) {
1859                 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1860                      irq, cpumask_first(desc->percpu_enabled));
1861                 goto bad;
1862         }
1863 
1864         /* Found it - now remove it from the list of entries: */
1865         desc->action = NULL;
1866 
1867         raw_spin_unlock_irqrestore(&desc->lock, flags);
1868 
1869         unregister_handler_proc(irq, action);
1870 
1871         irq_chip_pm_put(&desc->irq_data);
1872         module_put(desc->owner);
1873         return action;
1874 
1875 bad:
1876         raw_spin_unlock_irqrestore(&desc->lock, flags);
1877         return NULL;
1878 }
1879 
1880 /**
1881  *      remove_percpu_irq - free a per-cpu interrupt
1882  *      @irq: Interrupt line to free
1883  *      @act: irqaction for the interrupt
1884  *
1885  * Used to remove interrupts statically setup by the early boot process.
1886  */
1887 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1888 {
1889         struct irq_desc *desc = irq_to_desc(irq);
1890 
1891         if (desc && irq_settings_is_per_cpu_devid(desc))
1892             __free_percpu_irq(irq, act->percpu_dev_id);
1893 }
1894 
1895 /**
1896  *      free_percpu_irq - free an interrupt allocated with request_percpu_irq
1897  *      @irq: Interrupt line to free
1898  *      @dev_id: Device identity to free
1899  *
1900  *      Remove a percpu interrupt handler. The handler is removed, but
1901  *      the interrupt line is not disabled. This must be done on each
1902  *      CPU before calling this function. The function does not return
1903  *      until any executing interrupts for this IRQ have completed.
1904  *
1905  *      This function must not be called from interrupt context.
1906  */
1907 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1908 {
1909         struct irq_desc *desc = irq_to_desc(irq);
1910 
1911         if (!desc || !irq_settings_is_per_cpu_devid(desc))
1912                 return;
1913 
1914         chip_bus_lock(desc);
1915         kfree(__free_percpu_irq(irq, dev_id));
1916         chip_bus_sync_unlock(desc);
1917 }
1918 EXPORT_SYMBOL_GPL(free_percpu_irq);
1919 
1920 /**
1921  *      setup_percpu_irq - setup a per-cpu interrupt
1922  *      @irq: Interrupt line to setup
1923  *      @act: irqaction for the interrupt
1924  *
1925  * Used to statically setup per-cpu interrupts in the early boot process.
1926  */
1927 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1928 {
1929         struct irq_desc *desc = irq_to_desc(irq);
1930         int retval;
1931 
1932         if (!desc || !irq_settings_is_per_cpu_devid(desc))
1933                 return -EINVAL;
1934 
1935         retval = irq_chip_pm_get(&desc->irq_data);
1936         if (retval < 0)
1937                 return retval;
1938 
1939         chip_bus_lock(desc);
1940         retval = __setup_irq(irq, desc, act);
1941         chip_bus_sync_unlock(desc);
1942 
1943         if (retval)
1944                 irq_chip_pm_put(&desc->irq_data);
1945 
1946         return retval;
1947 }
1948 
1949 /**
1950  *      request_percpu_irq - allocate a percpu interrupt line
1951  *      @irq: Interrupt line to allocate
1952  *      @handler: Function to be called when the IRQ occurs.
1953  *      @devname: An ascii name for the claiming device
1954  *      @dev_id: A percpu cookie passed back to the handler function
1955  *
1956  *      This call allocates interrupt resources and enables the
1957  *      interrupt on the local CPU. If the interrupt is supposed to be
1958  *      enabled on other CPUs, it has to be done on each CPU using
1959  *      enable_percpu_irq().
1960  *
1961  *      Dev_id must be globally unique. It is a per-cpu variable, and
1962  *      the handler gets called with the interrupted CPU's instance of
1963  *      that variable.
1964  */
1965 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1966                        const char *devname, void __percpu *dev_id)
1967 {
1968         struct irqaction *action;
1969         struct irq_desc *desc;
1970         int retval;
1971 
1972         if (!dev_id)
1973                 return -EINVAL;
1974 
1975         desc = irq_to_desc(irq);
1976         if (!desc || !irq_settings_can_request(desc) ||
1977             !irq_settings_is_per_cpu_devid(desc))
1978                 return -EINVAL;
1979 
1980         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1981         if (!action)
1982                 return -ENOMEM;
1983 
1984         action->handler = handler;
1985         action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1986         action->name = devname;
1987         action->percpu_dev_id = dev_id;
1988 
1989         retval = irq_chip_pm_get(&desc->irq_data);
1990         if (retval < 0) {
1991                 kfree(action);
1992                 return retval;
1993         }
1994 
1995         chip_bus_lock(desc);
1996         retval = __setup_irq(irq, desc, action);
1997         chip_bus_sync_unlock(desc);
1998 
1999         if (retval) {
2000                 irq_chip_pm_put(&desc->irq_data);
2001                 kfree(action);
2002         }
2003 
2004         return retval;
2005 }
2006 EXPORT_SYMBOL_GPL(request_percpu_irq);
2007 
2008 /**
2009  *      irq_get_irqchip_state - returns the irqchip state of a interrupt.
2010  *      @irq: Interrupt line that is forwarded to a VM
2011  *      @which: One of IRQCHIP_STATE_* the caller wants to know about
2012  *      @state: a pointer to a boolean where the state is to be storeed
2013  *
2014  *      This call snapshots the internal irqchip state of an
2015  *      interrupt, returning into @state the bit corresponding to
2016  *      stage @which
2017  *
2018  *      This function should be called with preemption disabled if the
2019  *      interrupt controller has per-cpu registers.
2020  */
2021 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2022                           bool *state)
2023 {
2024         struct irq_desc *desc;
2025         struct irq_data *data;
2026         struct irq_chip *chip;
2027         unsigned long flags;
2028         int err = -EINVAL;
2029 
2030         desc = irq_get_desc_buslock(irq, &flags, 0);
2031         if (!desc)
2032                 return err;
2033 
2034         data = irq_desc_get_irq_data(desc);
2035 
2036         do {
2037                 chip = irq_data_get_irq_chip(data);
2038                 if (chip->irq_get_irqchip_state)
2039                         break;
2040 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2041                 data = data->parent_data;
2042 #else
2043                 data = NULL;
2044 #endif
2045         } while (data);
2046 
2047         if (data)
2048                 err = chip->irq_get_irqchip_state(data, which, state);
2049 
2050         irq_put_desc_busunlock(desc, flags);
2051         return err;
2052 }
2053 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2054 
2055 /**
2056  *      irq_set_irqchip_state - set the state of a forwarded interrupt.
2057  *      @irq: Interrupt line that is forwarded to a VM
2058  *      @which: State to be restored (one of IRQCHIP_STATE_*)
2059  *      @val: Value corresponding to @which
2060  *
2061  *      This call sets the internal irqchip state of an interrupt,
2062  *      depending on the value of @which.
2063  *
2064  *      This function should be called with preemption disabled if the
2065  *      interrupt controller has per-cpu registers.
2066  */
2067 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2068                           bool val)
2069 {
2070         struct irq_desc *desc;
2071         struct irq_data *data;
2072         struct irq_chip *chip;
2073         unsigned long flags;
2074         int err = -EINVAL;
2075 
2076         desc = irq_get_desc_buslock(irq, &flags, 0);
2077         if (!desc)
2078                 return err;
2079 
2080         data = irq_desc_get_irq_data(desc);
2081 
2082         do {
2083                 chip = irq_data_get_irq_chip(data);
2084                 if (chip->irq_set_irqchip_state)
2085                         break;
2086 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2087                 data = data->parent_data;
2088 #else
2089                 data = NULL;
2090 #endif
2091         } while (data);
2092 
2093         if (data)
2094                 err = chip->irq_set_irqchip_state(data, which, val);
2095 
2096         irq_put_desc_busunlock(desc, flags);
2097         return err;
2098 }
2099 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2100 

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