~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/irq/manage.c

Version: ~ [ linux-5.3-rc8 ] ~ [ linux-5.2.13 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.71 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.142 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.191 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.191 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.73 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/sched/task.h>
 21 #include <uapi/linux/sched/types.h>
 22 #include <linux/task_work.h>
 23 
 24 #include "internals.h"
 25 
 26 #ifdef CONFIG_IRQ_FORCED_THREADING
 27 __read_mostly bool force_irqthreads;
 28 
 29 static int __init setup_forced_irqthreads(char *arg)
 30 {
 31         force_irqthreads = true;
 32         return 0;
 33 }
 34 early_param("threadirqs", setup_forced_irqthreads);
 35 #endif
 36 
 37 static void __synchronize_hardirq(struct irq_desc *desc)
 38 {
 39         bool inprogress;
 40 
 41         do {
 42                 unsigned long flags;
 43 
 44                 /*
 45                  * Wait until we're out of the critical section.  This might
 46                  * give the wrong answer due to the lack of memory barriers.
 47                  */
 48                 while (irqd_irq_inprogress(&desc->irq_data))
 49                         cpu_relax();
 50 
 51                 /* Ok, that indicated we're done: double-check carefully. */
 52                 raw_spin_lock_irqsave(&desc->lock, flags);
 53                 inprogress = irqd_irq_inprogress(&desc->irq_data);
 54                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 55 
 56                 /* Oops, that failed? */
 57         } while (inprogress);
 58 }
 59 
 60 /**
 61  *      synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
 62  *      @irq: interrupt number to wait for
 63  *
 64  *      This function waits for any pending hard IRQ handlers for this
 65  *      interrupt to complete before returning. If you use this
 66  *      function while holding a resource the IRQ handler may need you
 67  *      will deadlock. It does not take associated threaded handlers
 68  *      into account.
 69  *
 70  *      Do not use this for shutdown scenarios where you must be sure
 71  *      that all parts (hardirq and threaded handler) have completed.
 72  *
 73  *      Returns: false if a threaded handler is active.
 74  *
 75  *      This function may be called - with care - from IRQ context.
 76  */
 77 bool synchronize_hardirq(unsigned int irq)
 78 {
 79         struct irq_desc *desc = irq_to_desc(irq);
 80 
 81         if (desc) {
 82                 __synchronize_hardirq(desc);
 83                 return !atomic_read(&desc->threads_active);
 84         }
 85 
 86         return true;
 87 }
 88 EXPORT_SYMBOL(synchronize_hardirq);
 89 
 90 /**
 91  *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
 92  *      @irq: interrupt number to wait for
 93  *
 94  *      This function waits for any pending IRQ handlers for this interrupt
 95  *      to complete before returning. If you use this function while
 96  *      holding a resource the IRQ handler may need you will deadlock.
 97  *
 98  *      This function may be called - with care - from IRQ context.
 99  */
100 void synchronize_irq(unsigned int irq)
101 {
102         struct irq_desc *desc = irq_to_desc(irq);
103 
104         if (desc) {
105                 __synchronize_hardirq(desc);
106                 /*
107                  * We made sure that no hardirq handler is
108                  * running. Now verify that no threaded handlers are
109                  * active.
110                  */
111                 wait_event(desc->wait_for_threads,
112                            !atomic_read(&desc->threads_active));
113         }
114 }
115 EXPORT_SYMBOL(synchronize_irq);
116 
117 #ifdef CONFIG_SMP
118 cpumask_var_t irq_default_affinity;
119 
120 static bool __irq_can_set_affinity(struct irq_desc *desc)
121 {
122         if (!desc || !irqd_can_balance(&desc->irq_data) ||
123             !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
124                 return false;
125         return true;
126 }
127 
128 /**
129  *      irq_can_set_affinity - Check if the affinity of a given irq can be set
130  *      @irq:           Interrupt to check
131  *
132  */
133 int irq_can_set_affinity(unsigned int irq)
134 {
135         return __irq_can_set_affinity(irq_to_desc(irq));
136 }
137 
138 /**
139  * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
140  * @irq:        Interrupt to check
141  *
142  * Like irq_can_set_affinity() above, but additionally checks for the
143  * AFFINITY_MANAGED flag.
144  */
145 bool irq_can_set_affinity_usr(unsigned int irq)
146 {
147         struct irq_desc *desc = irq_to_desc(irq);
148 
149         return __irq_can_set_affinity(desc) &&
150                 !irqd_affinity_is_managed(&desc->irq_data);
151 }
152 
153 /**
154  *      irq_set_thread_affinity - Notify irq threads to adjust affinity
155  *      @desc:          irq descriptor which has affitnity changed
156  *
157  *      We just set IRQTF_AFFINITY and delegate the affinity setting
158  *      to the interrupt thread itself. We can not call
159  *      set_cpus_allowed_ptr() here as we hold desc->lock and this
160  *      code can be called from hard interrupt context.
161  */
162 void irq_set_thread_affinity(struct irq_desc *desc)
163 {
164         struct irqaction *action;
165 
166         for_each_action_of_desc(desc, action)
167                 if (action->thread)
168                         set_bit(IRQTF_AFFINITY, &action->thread_flags);
169 }
170 
171 static void irq_validate_effective_affinity(struct irq_data *data)
172 {
173 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
174         const struct cpumask *m = irq_data_get_effective_affinity_mask(data);
175         struct irq_chip *chip = irq_data_get_irq_chip(data);
176 
177         if (!cpumask_empty(m))
178                 return;
179         pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n",
180                      chip->name, data->irq);
181 #endif
182 }
183 
184 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
185                         bool force)
186 {
187         struct irq_desc *desc = irq_data_to_desc(data);
188         struct irq_chip *chip = irq_data_get_irq_chip(data);
189         int ret;
190 
191         if (!chip || !chip->irq_set_affinity)
192                 return -EINVAL;
193 
194         ret = chip->irq_set_affinity(data, mask, force);
195         switch (ret) {
196         case IRQ_SET_MASK_OK:
197         case IRQ_SET_MASK_OK_DONE:
198                 cpumask_copy(desc->irq_common_data.affinity, mask);
199         case IRQ_SET_MASK_OK_NOCOPY:
200                 irq_validate_effective_affinity(data);
201                 irq_set_thread_affinity(desc);
202                 ret = 0;
203         }
204 
205         return ret;
206 }
207 
208 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
209                             bool force)
210 {
211         struct irq_chip *chip = irq_data_get_irq_chip(data);
212         struct irq_desc *desc = irq_data_to_desc(data);
213         int ret = 0;
214 
215         if (!chip || !chip->irq_set_affinity)
216                 return -EINVAL;
217 
218         if (irq_can_move_pcntxt(data)) {
219                 ret = irq_do_set_affinity(data, mask, force);
220         } else {
221                 irqd_set_move_pending(data);
222                 irq_copy_pending(desc, mask);
223         }
224 
225         if (desc->affinity_notify) {
226                 kref_get(&desc->affinity_notify->kref);
227                 schedule_work(&desc->affinity_notify->work);
228         }
229         irqd_set(data, IRQD_AFFINITY_SET);
230 
231         return ret;
232 }
233 
234 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
235 {
236         struct irq_desc *desc = irq_to_desc(irq);
237         unsigned long flags;
238         int ret;
239 
240         if (!desc)
241                 return -EINVAL;
242 
243         raw_spin_lock_irqsave(&desc->lock, flags);
244         ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
245         raw_spin_unlock_irqrestore(&desc->lock, flags);
246         return ret;
247 }
248 
249 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
250 {
251         unsigned long flags;
252         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
253 
254         if (!desc)
255                 return -EINVAL;
256         desc->affinity_hint = m;
257         irq_put_desc_unlock(desc, flags);
258         /* set the initial affinity to prevent every interrupt being on CPU0 */
259         if (m)
260                 __irq_set_affinity(irq, m, false);
261         return 0;
262 }
263 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
264 
265 static void irq_affinity_notify(struct work_struct *work)
266 {
267         struct irq_affinity_notify *notify =
268                 container_of(work, struct irq_affinity_notify, work);
269         struct irq_desc *desc = irq_to_desc(notify->irq);
270         cpumask_var_t cpumask;
271         unsigned long flags;
272 
273         if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
274                 goto out;
275 
276         raw_spin_lock_irqsave(&desc->lock, flags);
277         if (irq_move_pending(&desc->irq_data))
278                 irq_get_pending(cpumask, desc);
279         else
280                 cpumask_copy(cpumask, desc->irq_common_data.affinity);
281         raw_spin_unlock_irqrestore(&desc->lock, flags);
282 
283         notify->notify(notify, cpumask);
284 
285         free_cpumask_var(cpumask);
286 out:
287         kref_put(&notify->kref, notify->release);
288 }
289 
290 /**
291  *      irq_set_affinity_notifier - control notification of IRQ affinity changes
292  *      @irq:           Interrupt for which to enable/disable notification
293  *      @notify:        Context for notification, or %NULL to disable
294  *                      notification.  Function pointers must be initialised;
295  *                      the other fields will be initialised by this function.
296  *
297  *      Must be called in process context.  Notification may only be enabled
298  *      after the IRQ is allocated and must be disabled before the IRQ is
299  *      freed using free_irq().
300  */
301 int
302 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
303 {
304         struct irq_desc *desc = irq_to_desc(irq);
305         struct irq_affinity_notify *old_notify;
306         unsigned long flags;
307 
308         /* The release function is promised process context */
309         might_sleep();
310 
311         if (!desc)
312                 return -EINVAL;
313 
314         /* Complete initialisation of *notify */
315         if (notify) {
316                 notify->irq = irq;
317                 kref_init(&notify->kref);
318                 INIT_WORK(&notify->work, irq_affinity_notify);
319         }
320 
321         raw_spin_lock_irqsave(&desc->lock, flags);
322         old_notify = desc->affinity_notify;
323         desc->affinity_notify = notify;
324         raw_spin_unlock_irqrestore(&desc->lock, flags);
325 
326         if (old_notify)
327                 kref_put(&old_notify->kref, old_notify->release);
328 
329         return 0;
330 }
331 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
332 
333 #ifndef CONFIG_AUTO_IRQ_AFFINITY
334 /*
335  * Generic version of the affinity autoselector.
336  */
337 int irq_setup_affinity(struct irq_desc *desc)
338 {
339         struct cpumask *set = irq_default_affinity;
340         int ret, node = irq_desc_get_node(desc);
341         static DEFINE_RAW_SPINLOCK(mask_lock);
342         static struct cpumask mask;
343 
344         /* Excludes PER_CPU and NO_BALANCE interrupts */
345         if (!__irq_can_set_affinity(desc))
346                 return 0;
347 
348         raw_spin_lock(&mask_lock);
349         /*
350          * Preserve the managed affinity setting and a userspace affinity
351          * setup, but make sure that one of the targets is online.
352          */
353         if (irqd_affinity_is_managed(&desc->irq_data) ||
354             irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
355                 if (cpumask_intersects(desc->irq_common_data.affinity,
356                                        cpu_online_mask))
357                         set = desc->irq_common_data.affinity;
358                 else
359                         irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
360         }
361 
362         cpumask_and(&mask, cpu_online_mask, set);
363         if (node != NUMA_NO_NODE) {
364                 const struct cpumask *nodemask = cpumask_of_node(node);
365 
366                 /* make sure at least one of the cpus in nodemask is online */
367                 if (cpumask_intersects(&mask, nodemask))
368                         cpumask_and(&mask, &mask, nodemask);
369         }
370         ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
371         raw_spin_unlock(&mask_lock);
372         return ret;
373 }
374 #else
375 /* Wrapper for ALPHA specific affinity selector magic */
376 int irq_setup_affinity(struct irq_desc *desc)
377 {
378         return irq_select_affinity(irq_desc_get_irq(desc));
379 }
380 #endif
381 
382 /*
383  * Called when a bogus affinity is set via /proc/irq
384  */
385 int irq_select_affinity_usr(unsigned int irq)
386 {
387         struct irq_desc *desc = irq_to_desc(irq);
388         unsigned long flags;
389         int ret;
390 
391         raw_spin_lock_irqsave(&desc->lock, flags);
392         ret = irq_setup_affinity(desc);
393         raw_spin_unlock_irqrestore(&desc->lock, flags);
394         return ret;
395 }
396 #endif
397 
398 /**
399  *      irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
400  *      @irq: interrupt number to set affinity
401  *      @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU
402  *                  specific data for percpu_devid interrupts
403  *
404  *      This function uses the vCPU specific data to set the vCPU
405  *      affinity for an irq. The vCPU specific data is passed from
406  *      outside, such as KVM. One example code path is as below:
407  *      KVM -> IOMMU -> irq_set_vcpu_affinity().
408  */
409 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
410 {
411         unsigned long flags;
412         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
413         struct irq_data *data;
414         struct irq_chip *chip;
415         int ret = -ENOSYS;
416 
417         if (!desc)
418                 return -EINVAL;
419 
420         data = irq_desc_get_irq_data(desc);
421         do {
422                 chip = irq_data_get_irq_chip(data);
423                 if (chip && chip->irq_set_vcpu_affinity)
424                         break;
425 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
426                 data = data->parent_data;
427 #else
428                 data = NULL;
429 #endif
430         } while (data);
431 
432         if (data)
433                 ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
434         irq_put_desc_unlock(desc, flags);
435 
436         return ret;
437 }
438 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
439 
440 void __disable_irq(struct irq_desc *desc)
441 {
442         if (!desc->depth++)
443                 irq_disable(desc);
444 }
445 
446 static int __disable_irq_nosync(unsigned int irq)
447 {
448         unsigned long flags;
449         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
450 
451         if (!desc)
452                 return -EINVAL;
453         __disable_irq(desc);
454         irq_put_desc_busunlock(desc, flags);
455         return 0;
456 }
457 
458 /**
459  *      disable_irq_nosync - disable an irq without waiting
460  *      @irq: Interrupt to disable
461  *
462  *      Disable the selected interrupt line.  Disables and Enables are
463  *      nested.
464  *      Unlike disable_irq(), this function does not ensure existing
465  *      instances of the IRQ handler have completed before returning.
466  *
467  *      This function may be called from IRQ context.
468  */
469 void disable_irq_nosync(unsigned int irq)
470 {
471         __disable_irq_nosync(irq);
472 }
473 EXPORT_SYMBOL(disable_irq_nosync);
474 
475 /**
476  *      disable_irq - disable an irq and wait for completion
477  *      @irq: Interrupt to disable
478  *
479  *      Disable the selected interrupt line.  Enables and Disables are
480  *      nested.
481  *      This function waits for any pending IRQ handlers for this interrupt
482  *      to complete before returning. If you use this function while
483  *      holding a resource the IRQ handler may need you will deadlock.
484  *
485  *      This function may be called - with care - from IRQ context.
486  */
487 void disable_irq(unsigned int irq)
488 {
489         if (!__disable_irq_nosync(irq))
490                 synchronize_irq(irq);
491 }
492 EXPORT_SYMBOL(disable_irq);
493 
494 /**
495  *      disable_hardirq - disables an irq and waits for hardirq completion
496  *      @irq: Interrupt to disable
497  *
498  *      Disable the selected interrupt line.  Enables and Disables are
499  *      nested.
500  *      This function waits for any pending hard IRQ handlers for this
501  *      interrupt to complete before returning. If you use this function while
502  *      holding a resource the hard IRQ handler may need you will deadlock.
503  *
504  *      When used to optimistically disable an interrupt from atomic context
505  *      the return value must be checked.
506  *
507  *      Returns: false if a threaded handler is active.
508  *
509  *      This function may be called - with care - from IRQ context.
510  */
511 bool disable_hardirq(unsigned int irq)
512 {
513         if (!__disable_irq_nosync(irq))
514                 return synchronize_hardirq(irq);
515 
516         return false;
517 }
518 EXPORT_SYMBOL_GPL(disable_hardirq);
519 
520 void __enable_irq(struct irq_desc *desc)
521 {
522         switch (desc->depth) {
523         case 0:
524  err_out:
525                 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
526                      irq_desc_get_irq(desc));
527                 break;
528         case 1: {
529                 if (desc->istate & IRQS_SUSPENDED)
530                         goto err_out;
531                 /* Prevent probing on this irq: */
532                 irq_settings_set_noprobe(desc);
533                 /*
534                  * Call irq_startup() not irq_enable() here because the
535                  * interrupt might be marked NOAUTOEN. So irq_startup()
536                  * needs to be invoked when it gets enabled the first
537                  * time. If it was already started up, then irq_startup()
538                  * will invoke irq_enable() under the hood.
539                  */
540                 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
541                 break;
542         }
543         default:
544                 desc->depth--;
545         }
546 }
547 
548 /**
549  *      enable_irq - enable handling of an irq
550  *      @irq: Interrupt to enable
551  *
552  *      Undoes the effect of one call to disable_irq().  If this
553  *      matches the last disable, processing of interrupts on this
554  *      IRQ line is re-enabled.
555  *
556  *      This function may be called from IRQ context only when
557  *      desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
558  */
559 void enable_irq(unsigned int irq)
560 {
561         unsigned long flags;
562         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
563 
564         if (!desc)
565                 return;
566         if (WARN(!desc->irq_data.chip,
567                  KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
568                 goto out;
569 
570         __enable_irq(desc);
571 out:
572         irq_put_desc_busunlock(desc, flags);
573 }
574 EXPORT_SYMBOL(enable_irq);
575 
576 static int set_irq_wake_real(unsigned int irq, unsigned int on)
577 {
578         struct irq_desc *desc = irq_to_desc(irq);
579         int ret = -ENXIO;
580 
581         if (irq_desc_get_chip(desc)->flags &  IRQCHIP_SKIP_SET_WAKE)
582                 return 0;
583 
584         if (desc->irq_data.chip->irq_set_wake)
585                 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
586 
587         return ret;
588 }
589 
590 /**
591  *      irq_set_irq_wake - control irq power management wakeup
592  *      @irq:   interrupt to control
593  *      @on:    enable/disable power management wakeup
594  *
595  *      Enable/disable power management wakeup mode, which is
596  *      disabled by default.  Enables and disables must match,
597  *      just as they match for non-wakeup mode support.
598  *
599  *      Wakeup mode lets this IRQ wake the system from sleep
600  *      states like "suspend to RAM".
601  */
602 int irq_set_irq_wake(unsigned int irq, unsigned int on)
603 {
604         unsigned long flags;
605         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
606         int ret = 0;
607 
608         if (!desc)
609                 return -EINVAL;
610 
611         /* wakeup-capable irqs can be shared between drivers that
612          * don't need to have the same sleep mode behaviors.
613          */
614         if (on) {
615                 if (desc->wake_depth++ == 0) {
616                         ret = set_irq_wake_real(irq, on);
617                         if (ret)
618                                 desc->wake_depth = 0;
619                         else
620                                 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
621                 }
622         } else {
623                 if (desc->wake_depth == 0) {
624                         WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
625                 } else if (--desc->wake_depth == 0) {
626                         ret = set_irq_wake_real(irq, on);
627                         if (ret)
628                                 desc->wake_depth = 1;
629                         else
630                                 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
631                 }
632         }
633         irq_put_desc_busunlock(desc, flags);
634         return ret;
635 }
636 EXPORT_SYMBOL(irq_set_irq_wake);
637 
638 /*
639  * Internal function that tells the architecture code whether a
640  * particular irq has been exclusively allocated or is available
641  * for driver use.
642  */
643 int can_request_irq(unsigned int irq, unsigned long irqflags)
644 {
645         unsigned long flags;
646         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
647         int canrequest = 0;
648 
649         if (!desc)
650                 return 0;
651 
652         if (irq_settings_can_request(desc)) {
653                 if (!desc->action ||
654                     irqflags & desc->action->flags & IRQF_SHARED)
655                         canrequest = 1;
656         }
657         irq_put_desc_unlock(desc, flags);
658         return canrequest;
659 }
660 
661 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
662 {
663         struct irq_chip *chip = desc->irq_data.chip;
664         int ret, unmask = 0;
665 
666         if (!chip || !chip->irq_set_type) {
667                 /*
668                  * IRQF_TRIGGER_* but the PIC does not support multiple
669                  * flow-types?
670                  */
671                 pr_debug("No set_type function for IRQ %d (%s)\n",
672                          irq_desc_get_irq(desc),
673                          chip ? (chip->name ? : "unknown") : "unknown");
674                 return 0;
675         }
676 
677         if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
678                 if (!irqd_irq_masked(&desc->irq_data))
679                         mask_irq(desc);
680                 if (!irqd_irq_disabled(&desc->irq_data))
681                         unmask = 1;
682         }
683 
684         /* Mask all flags except trigger mode */
685         flags &= IRQ_TYPE_SENSE_MASK;
686         ret = chip->irq_set_type(&desc->irq_data, flags);
687 
688         switch (ret) {
689         case IRQ_SET_MASK_OK:
690         case IRQ_SET_MASK_OK_DONE:
691                 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
692                 irqd_set(&desc->irq_data, flags);
693 
694         case IRQ_SET_MASK_OK_NOCOPY:
695                 flags = irqd_get_trigger_type(&desc->irq_data);
696                 irq_settings_set_trigger_mask(desc, flags);
697                 irqd_clear(&desc->irq_data, IRQD_LEVEL);
698                 irq_settings_clr_level(desc);
699                 if (flags & IRQ_TYPE_LEVEL_MASK) {
700                         irq_settings_set_level(desc);
701                         irqd_set(&desc->irq_data, IRQD_LEVEL);
702                 }
703 
704                 ret = 0;
705                 break;
706         default:
707                 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
708                        flags, irq_desc_get_irq(desc), chip->irq_set_type);
709         }
710         if (unmask)
711                 unmask_irq(desc);
712         return ret;
713 }
714 
715 #ifdef CONFIG_HARDIRQS_SW_RESEND
716 int irq_set_parent(int irq, int parent_irq)
717 {
718         unsigned long flags;
719         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
720 
721         if (!desc)
722                 return -EINVAL;
723 
724         desc->parent_irq = parent_irq;
725 
726         irq_put_desc_unlock(desc, flags);
727         return 0;
728 }
729 EXPORT_SYMBOL_GPL(irq_set_parent);
730 #endif
731 
732 /*
733  * Default primary interrupt handler for threaded interrupts. Is
734  * assigned as primary handler when request_threaded_irq is called
735  * with handler == NULL. Useful for oneshot interrupts.
736  */
737 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
738 {
739         return IRQ_WAKE_THREAD;
740 }
741 
742 /*
743  * Primary handler for nested threaded interrupts. Should never be
744  * called.
745  */
746 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
747 {
748         WARN(1, "Primary handler called for nested irq %d\n", irq);
749         return IRQ_NONE;
750 }
751 
752 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
753 {
754         WARN(1, "Secondary action handler called for irq %d\n", irq);
755         return IRQ_NONE;
756 }
757 
758 static int irq_wait_for_interrupt(struct irqaction *action)
759 {
760         set_current_state(TASK_INTERRUPTIBLE);
761 
762         while (!kthread_should_stop()) {
763 
764                 if (test_and_clear_bit(IRQTF_RUNTHREAD,
765                                        &action->thread_flags)) {
766                         __set_current_state(TASK_RUNNING);
767                         return 0;
768                 }
769                 schedule();
770                 set_current_state(TASK_INTERRUPTIBLE);
771         }
772         __set_current_state(TASK_RUNNING);
773         return -1;
774 }
775 
776 /*
777  * Oneshot interrupts keep the irq line masked until the threaded
778  * handler finished. unmask if the interrupt has not been disabled and
779  * is marked MASKED.
780  */
781 static void irq_finalize_oneshot(struct irq_desc *desc,
782                                  struct irqaction *action)
783 {
784         if (!(desc->istate & IRQS_ONESHOT) ||
785             action->handler == irq_forced_secondary_handler)
786                 return;
787 again:
788         chip_bus_lock(desc);
789         raw_spin_lock_irq(&desc->lock);
790 
791         /*
792          * Implausible though it may be we need to protect us against
793          * the following scenario:
794          *
795          * The thread is faster done than the hard interrupt handler
796          * on the other CPU. If we unmask the irq line then the
797          * interrupt can come in again and masks the line, leaves due
798          * to IRQS_INPROGRESS and the irq line is masked forever.
799          *
800          * This also serializes the state of shared oneshot handlers
801          * versus "desc->threads_onehsot |= action->thread_mask;" in
802          * irq_wake_thread(). See the comment there which explains the
803          * serialization.
804          */
805         if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
806                 raw_spin_unlock_irq(&desc->lock);
807                 chip_bus_sync_unlock(desc);
808                 cpu_relax();
809                 goto again;
810         }
811 
812         /*
813          * Now check again, whether the thread should run. Otherwise
814          * we would clear the threads_oneshot bit of this thread which
815          * was just set.
816          */
817         if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
818                 goto out_unlock;
819 
820         desc->threads_oneshot &= ~action->thread_mask;
821 
822         if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
823             irqd_irq_masked(&desc->irq_data))
824                 unmask_threaded_irq(desc);
825 
826 out_unlock:
827         raw_spin_unlock_irq(&desc->lock);
828         chip_bus_sync_unlock(desc);
829 }
830 
831 #ifdef CONFIG_SMP
832 /*
833  * Check whether we need to change the affinity of the interrupt thread.
834  */
835 static void
836 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
837 {
838         cpumask_var_t mask;
839         bool valid = true;
840 
841         if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
842                 return;
843 
844         /*
845          * In case we are out of memory we set IRQTF_AFFINITY again and
846          * try again next time
847          */
848         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
849                 set_bit(IRQTF_AFFINITY, &action->thread_flags);
850                 return;
851         }
852 
853         raw_spin_lock_irq(&desc->lock);
854         /*
855          * This code is triggered unconditionally. Check the affinity
856          * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
857          */
858         if (cpumask_available(desc->irq_common_data.affinity))
859                 cpumask_copy(mask, desc->irq_common_data.affinity);
860         else
861                 valid = false;
862         raw_spin_unlock_irq(&desc->lock);
863 
864         if (valid)
865                 set_cpus_allowed_ptr(current, mask);
866         free_cpumask_var(mask);
867 }
868 #else
869 static inline void
870 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
871 #endif
872 
873 /*
874  * Interrupts which are not explicitely requested as threaded
875  * interrupts rely on the implicit bh/preempt disable of the hard irq
876  * context. So we need to disable bh here to avoid deadlocks and other
877  * side effects.
878  */
879 static irqreturn_t
880 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
881 {
882         irqreturn_t ret;
883 
884         local_bh_disable();
885         ret = action->thread_fn(action->irq, action->dev_id);
886         irq_finalize_oneshot(desc, action);
887         local_bh_enable();
888         return ret;
889 }
890 
891 /*
892  * Interrupts explicitly requested as threaded interrupts want to be
893  * preemtible - many of them need to sleep and wait for slow busses to
894  * complete.
895  */
896 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
897                 struct irqaction *action)
898 {
899         irqreturn_t ret;
900 
901         ret = action->thread_fn(action->irq, action->dev_id);
902         irq_finalize_oneshot(desc, action);
903         return ret;
904 }
905 
906 static void wake_threads_waitq(struct irq_desc *desc)
907 {
908         if (atomic_dec_and_test(&desc->threads_active))
909                 wake_up(&desc->wait_for_threads);
910 }
911 
912 static void irq_thread_dtor(struct callback_head *unused)
913 {
914         struct task_struct *tsk = current;
915         struct irq_desc *desc;
916         struct irqaction *action;
917 
918         if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
919                 return;
920 
921         action = kthread_data(tsk);
922 
923         pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
924                tsk->comm, tsk->pid, action->irq);
925 
926 
927         desc = irq_to_desc(action->irq);
928         /*
929          * If IRQTF_RUNTHREAD is set, we need to decrement
930          * desc->threads_active and wake possible waiters.
931          */
932         if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
933                 wake_threads_waitq(desc);
934 
935         /* Prevent a stale desc->threads_oneshot */
936         irq_finalize_oneshot(desc, action);
937 }
938 
939 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
940 {
941         struct irqaction *secondary = action->secondary;
942 
943         if (WARN_ON_ONCE(!secondary))
944                 return;
945 
946         raw_spin_lock_irq(&desc->lock);
947         __irq_wake_thread(desc, secondary);
948         raw_spin_unlock_irq(&desc->lock);
949 }
950 
951 /*
952  * Interrupt handler thread
953  */
954 static int irq_thread(void *data)
955 {
956         struct callback_head on_exit_work;
957         struct irqaction *action = data;
958         struct irq_desc *desc = irq_to_desc(action->irq);
959         irqreturn_t (*handler_fn)(struct irq_desc *desc,
960                         struct irqaction *action);
961 
962         if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
963                                         &action->thread_flags))
964                 handler_fn = irq_forced_thread_fn;
965         else
966                 handler_fn = irq_thread_fn;
967 
968         init_task_work(&on_exit_work, irq_thread_dtor);
969         task_work_add(current, &on_exit_work, false);
970 
971         irq_thread_check_affinity(desc, action);
972 
973         while (!irq_wait_for_interrupt(action)) {
974                 irqreturn_t action_ret;
975 
976                 irq_thread_check_affinity(desc, action);
977 
978                 action_ret = handler_fn(desc, action);
979                 if (action_ret == IRQ_HANDLED)
980                         atomic_inc(&desc->threads_handled);
981                 if (action_ret == IRQ_WAKE_THREAD)
982                         irq_wake_secondary(desc, action);
983 
984                 wake_threads_waitq(desc);
985         }
986 
987         /*
988          * This is the regular exit path. __free_irq() is stopping the
989          * thread via kthread_stop() after calling
990          * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
991          * oneshot mask bit can be set. We cannot verify that as we
992          * cannot touch the oneshot mask at this point anymore as
993          * __setup_irq() might have given out currents thread_mask
994          * again.
995          */
996         task_work_cancel(current, irq_thread_dtor);
997         return 0;
998 }
999 
1000 /**
1001  *      irq_wake_thread - wake the irq thread for the action identified by dev_id
1002  *      @irq:           Interrupt line
1003  *      @dev_id:        Device identity for which the thread should be woken
1004  *
1005  */
1006 void irq_wake_thread(unsigned int irq, void *dev_id)
1007 {
1008         struct irq_desc *desc = irq_to_desc(irq);
1009         struct irqaction *action;
1010         unsigned long flags;
1011 
1012         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1013                 return;
1014 
1015         raw_spin_lock_irqsave(&desc->lock, flags);
1016         for_each_action_of_desc(desc, action) {
1017                 if (action->dev_id == dev_id) {
1018                         if (action->thread)
1019                                 __irq_wake_thread(desc, action);
1020                         break;
1021                 }
1022         }
1023         raw_spin_unlock_irqrestore(&desc->lock, flags);
1024 }
1025 EXPORT_SYMBOL_GPL(irq_wake_thread);
1026 
1027 static int irq_setup_forced_threading(struct irqaction *new)
1028 {
1029         if (!force_irqthreads)
1030                 return 0;
1031         if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1032                 return 0;
1033 
1034         new->flags |= IRQF_ONESHOT;
1035 
1036         /*
1037          * Handle the case where we have a real primary handler and a
1038          * thread handler. We force thread them as well by creating a
1039          * secondary action.
1040          */
1041         if (new->handler != irq_default_primary_handler && new->thread_fn) {
1042                 /* Allocate the secondary action */
1043                 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1044                 if (!new->secondary)
1045                         return -ENOMEM;
1046                 new->secondary->handler = irq_forced_secondary_handler;
1047                 new->secondary->thread_fn = new->thread_fn;
1048                 new->secondary->dev_id = new->dev_id;
1049                 new->secondary->irq = new->irq;
1050                 new->secondary->name = new->name;
1051         }
1052         /* Deal with the primary handler */
1053         set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1054         new->thread_fn = new->handler;
1055         new->handler = irq_default_primary_handler;
1056         return 0;
1057 }
1058 
1059 static int irq_request_resources(struct irq_desc *desc)
1060 {
1061         struct irq_data *d = &desc->irq_data;
1062         struct irq_chip *c = d->chip;
1063 
1064         return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1065 }
1066 
1067 static void irq_release_resources(struct irq_desc *desc)
1068 {
1069         struct irq_data *d = &desc->irq_data;
1070         struct irq_chip *c = d->chip;
1071 
1072         if (c->irq_release_resources)
1073                 c->irq_release_resources(d);
1074 }
1075 
1076 static int
1077 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1078 {
1079         struct task_struct *t;
1080         struct sched_param param = {
1081                 .sched_priority = MAX_USER_RT_PRIO/2,
1082         };
1083 
1084         if (!secondary) {
1085                 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1086                                    new->name);
1087         } else {
1088                 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1089                                    new->name);
1090                 param.sched_priority -= 1;
1091         }
1092 
1093         if (IS_ERR(t))
1094                 return PTR_ERR(t);
1095 
1096         sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
1097 
1098         /*
1099          * We keep the reference to the task struct even if
1100          * the thread dies to avoid that the interrupt code
1101          * references an already freed task_struct.
1102          */
1103         get_task_struct(t);
1104         new->thread = t;
1105         /*
1106          * Tell the thread to set its affinity. This is
1107          * important for shared interrupt handlers as we do
1108          * not invoke setup_affinity() for the secondary
1109          * handlers as everything is already set up. Even for
1110          * interrupts marked with IRQF_NO_BALANCE this is
1111          * correct as we want the thread to move to the cpu(s)
1112          * on which the requesting code placed the interrupt.
1113          */
1114         set_bit(IRQTF_AFFINITY, &new->thread_flags);
1115         return 0;
1116 }
1117 
1118 /*
1119  * Internal function to register an irqaction - typically used to
1120  * allocate special interrupts that are part of the architecture.
1121  *
1122  * Locking rules:
1123  *
1124  * desc->request_mutex  Provides serialization against a concurrent free_irq()
1125  *   chip_bus_lock      Provides serialization for slow bus operations
1126  *     desc->lock       Provides serialization against hard interrupts
1127  *
1128  * chip_bus_lock and desc->lock are sufficient for all other management and
1129  * interrupt related functions. desc->request_mutex solely serializes
1130  * request/free_irq().
1131  */
1132 static int
1133 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1134 {
1135         struct irqaction *old, **old_ptr;
1136         unsigned long flags, thread_mask = 0;
1137         int ret, nested, shared = 0;
1138 
1139         if (!desc)
1140                 return -EINVAL;
1141 
1142         if (desc->irq_data.chip == &no_irq_chip)
1143                 return -ENOSYS;
1144         if (!try_module_get(desc->owner))
1145                 return -ENODEV;
1146 
1147         new->irq = irq;
1148 
1149         /*
1150          * If the trigger type is not specified by the caller,
1151          * then use the default for this interrupt.
1152          */
1153         if (!(new->flags & IRQF_TRIGGER_MASK))
1154                 new->flags |= irqd_get_trigger_type(&desc->irq_data);
1155 
1156         /*
1157          * Check whether the interrupt nests into another interrupt
1158          * thread.
1159          */
1160         nested = irq_settings_is_nested_thread(desc);
1161         if (nested) {
1162                 if (!new->thread_fn) {
1163                         ret = -EINVAL;
1164                         goto out_mput;
1165                 }
1166                 /*
1167                  * Replace the primary handler which was provided from
1168                  * the driver for non nested interrupt handling by the
1169                  * dummy function which warns when called.
1170                  */
1171                 new->handler = irq_nested_primary_handler;
1172         } else {
1173                 if (irq_settings_can_thread(desc)) {
1174                         ret = irq_setup_forced_threading(new);
1175                         if (ret)
1176                                 goto out_mput;
1177                 }
1178         }
1179 
1180         /*
1181          * Create a handler thread when a thread function is supplied
1182          * and the interrupt does not nest into another interrupt
1183          * thread.
1184          */
1185         if (new->thread_fn && !nested) {
1186                 ret = setup_irq_thread(new, irq, false);
1187                 if (ret)
1188                         goto out_mput;
1189                 if (new->secondary) {
1190                         ret = setup_irq_thread(new->secondary, irq, true);
1191                         if (ret)
1192                                 goto out_thread;
1193                 }
1194         }
1195 
1196         /*
1197          * Drivers are often written to work w/o knowledge about the
1198          * underlying irq chip implementation, so a request for a
1199          * threaded irq without a primary hard irq context handler
1200          * requires the ONESHOT flag to be set. Some irq chips like
1201          * MSI based interrupts are per se one shot safe. Check the
1202          * chip flags, so we can avoid the unmask dance at the end of
1203          * the threaded handler for those.
1204          */
1205         if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1206                 new->flags &= ~IRQF_ONESHOT;
1207 
1208         /*
1209          * Protects against a concurrent __free_irq() call which might wait
1210          * for synchronize_irq() to complete without holding the optional
1211          * chip bus lock and desc->lock.
1212          */
1213         mutex_lock(&desc->request_mutex);
1214 
1215         /*
1216          * Acquire bus lock as the irq_request_resources() callback below
1217          * might rely on the serialization or the magic power management
1218          * functions which are abusing the irq_bus_lock() callback,
1219          */
1220         chip_bus_lock(desc);
1221 
1222         /* First installed action requests resources. */
1223         if (!desc->action) {
1224                 ret = irq_request_resources(desc);
1225                 if (ret) {
1226                         pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1227                                new->name, irq, desc->irq_data.chip->name);
1228                         goto out_bus_unlock;
1229                 }
1230         }
1231 
1232         /*
1233          * The following block of code has to be executed atomically
1234          * protected against a concurrent interrupt and any of the other
1235          * management calls which are not serialized via
1236          * desc->request_mutex or the optional bus lock.
1237          */
1238         raw_spin_lock_irqsave(&desc->lock, flags);
1239         old_ptr = &desc->action;
1240         old = *old_ptr;
1241         if (old) {
1242                 /*
1243                  * Can't share interrupts unless both agree to and are
1244                  * the same type (level, edge, polarity). So both flag
1245                  * fields must have IRQF_SHARED set and the bits which
1246                  * set the trigger type must match. Also all must
1247                  * agree on ONESHOT.
1248                  */
1249                 unsigned int oldtype;
1250 
1251                 /*
1252                  * If nobody did set the configuration before, inherit
1253                  * the one provided by the requester.
1254                  */
1255                 if (irqd_trigger_type_was_set(&desc->irq_data)) {
1256                         oldtype = irqd_get_trigger_type(&desc->irq_data);
1257                 } else {
1258                         oldtype = new->flags & IRQF_TRIGGER_MASK;
1259                         irqd_set_trigger_type(&desc->irq_data, oldtype);
1260                 }
1261 
1262                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
1263                     (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
1264                     ((old->flags ^ new->flags) & IRQF_ONESHOT))
1265                         goto mismatch;
1266 
1267                 /* All handlers must agree on per-cpuness */
1268                 if ((old->flags & IRQF_PERCPU) !=
1269                     (new->flags & IRQF_PERCPU))
1270                         goto mismatch;
1271 
1272                 /* add new interrupt at end of irq queue */
1273                 do {
1274                         /*
1275                          * Or all existing action->thread_mask bits,
1276                          * so we can find the next zero bit for this
1277                          * new action.
1278                          */
1279                         thread_mask |= old->thread_mask;
1280                         old_ptr = &old->next;
1281                         old = *old_ptr;
1282                 } while (old);
1283                 shared = 1;
1284         }
1285 
1286         /*
1287          * Setup the thread mask for this irqaction for ONESHOT. For
1288          * !ONESHOT irqs the thread mask is 0 so we can avoid a
1289          * conditional in irq_wake_thread().
1290          */
1291         if (new->flags & IRQF_ONESHOT) {
1292                 /*
1293                  * Unlikely to have 32 resp 64 irqs sharing one line,
1294                  * but who knows.
1295                  */
1296                 if (thread_mask == ~0UL) {
1297                         ret = -EBUSY;
1298                         goto out_unlock;
1299                 }
1300                 /*
1301                  * The thread_mask for the action is or'ed to
1302                  * desc->thread_active to indicate that the
1303                  * IRQF_ONESHOT thread handler has been woken, but not
1304                  * yet finished. The bit is cleared when a thread
1305                  * completes. When all threads of a shared interrupt
1306                  * line have completed desc->threads_active becomes
1307                  * zero and the interrupt line is unmasked. See
1308                  * handle.c:irq_wake_thread() for further information.
1309                  *
1310                  * If no thread is woken by primary (hard irq context)
1311                  * interrupt handlers, then desc->threads_active is
1312                  * also checked for zero to unmask the irq line in the
1313                  * affected hard irq flow handlers
1314                  * (handle_[fasteoi|level]_irq).
1315                  *
1316                  * The new action gets the first zero bit of
1317                  * thread_mask assigned. See the loop above which or's
1318                  * all existing action->thread_mask bits.
1319                  */
1320                 new->thread_mask = 1UL << ffz(thread_mask);
1321 
1322         } else if (new->handler == irq_default_primary_handler &&
1323                    !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1324                 /*
1325                  * The interrupt was requested with handler = NULL, so
1326                  * we use the default primary handler for it. But it
1327                  * does not have the oneshot flag set. In combination
1328                  * with level interrupts this is deadly, because the
1329                  * default primary handler just wakes the thread, then
1330                  * the irq lines is reenabled, but the device still
1331                  * has the level irq asserted. Rinse and repeat....
1332                  *
1333                  * While this works for edge type interrupts, we play
1334                  * it safe and reject unconditionally because we can't
1335                  * say for sure which type this interrupt really
1336                  * has. The type flags are unreliable as the
1337                  * underlying chip implementation can override them.
1338                  */
1339                 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1340                        irq);
1341                 ret = -EINVAL;
1342                 goto out_unlock;
1343         }
1344 
1345         if (!shared) {
1346                 init_waitqueue_head(&desc->wait_for_threads);
1347 
1348                 /* Setup the type (level, edge polarity) if configured: */
1349                 if (new->flags & IRQF_TRIGGER_MASK) {
1350                         ret = __irq_set_trigger(desc,
1351                                                 new->flags & IRQF_TRIGGER_MASK);
1352 
1353                         if (ret)
1354                                 goto out_unlock;
1355                 }
1356 
1357                 /*
1358                  * Activate the interrupt. That activation must happen
1359                  * independently of IRQ_NOAUTOEN. request_irq() can fail
1360                  * and the callers are supposed to handle
1361                  * that. enable_irq() of an interrupt requested with
1362                  * IRQ_NOAUTOEN is not supposed to fail. The activation
1363                  * keeps it in shutdown mode, it merily associates
1364                  * resources if necessary and if that's not possible it
1365                  * fails. Interrupts which are in managed shutdown mode
1366                  * will simply ignore that activation request.
1367                  */
1368                 ret = irq_activate(desc);
1369                 if (ret)
1370                         goto out_unlock;
1371 
1372                 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1373                                   IRQS_ONESHOT | IRQS_WAITING);
1374                 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1375 
1376                 if (new->flags & IRQF_PERCPU) {
1377                         irqd_set(&desc->irq_data, IRQD_PER_CPU);
1378                         irq_settings_set_per_cpu(desc);
1379                 }
1380 
1381                 if (new->flags & IRQF_ONESHOT)
1382                         desc->istate |= IRQS_ONESHOT;
1383 
1384                 /* Exclude IRQ from balancing if requested */
1385                 if (new->flags & IRQF_NOBALANCING) {
1386                         irq_settings_set_no_balancing(desc);
1387                         irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1388                 }
1389 
1390                 if (irq_settings_can_autoenable(desc)) {
1391                         irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
1392                 } else {
1393                         /*
1394                          * Shared interrupts do not go well with disabling
1395                          * auto enable. The sharing interrupt might request
1396                          * it while it's still disabled and then wait for
1397                          * interrupts forever.
1398                          */
1399                         WARN_ON_ONCE(new->flags & IRQF_SHARED);
1400                         /* Undo nested disables: */
1401                         desc->depth = 1;
1402                 }
1403 
1404         } else if (new->flags & IRQF_TRIGGER_MASK) {
1405                 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1406                 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);
1407 
1408                 if (nmsk != omsk)
1409                         /* hope the handler works with current  trigger mode */
1410                         pr_warn("irq %d uses trigger mode %u; requested %u\n",
1411                                 irq, omsk, nmsk);
1412         }
1413 
1414         *old_ptr = new;
1415 
1416         irq_pm_install_action(desc, new);
1417 
1418         /* Reset broken irq detection when installing new handler */
1419         desc->irq_count = 0;
1420         desc->irqs_unhandled = 0;
1421 
1422         /*
1423          * Check whether we disabled the irq via the spurious handler
1424          * before. Reenable it and give it another chance.
1425          */
1426         if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1427                 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1428                 __enable_irq(desc);
1429         }
1430 
1431         raw_spin_unlock_irqrestore(&desc->lock, flags);
1432         chip_bus_sync_unlock(desc);
1433         mutex_unlock(&desc->request_mutex);
1434 
1435         irq_setup_timings(desc, new);
1436 
1437         /*
1438          * Strictly no need to wake it up, but hung_task complains
1439          * when no hard interrupt wakes the thread up.
1440          */
1441         if (new->thread)
1442                 wake_up_process(new->thread);
1443         if (new->secondary)
1444                 wake_up_process(new->secondary->thread);
1445 
1446         register_irq_proc(irq, desc);
1447         new->dir = NULL;
1448         register_handler_proc(irq, new);
1449         return 0;
1450 
1451 mismatch:
1452         if (!(new->flags & IRQF_PROBE_SHARED)) {
1453                 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1454                        irq, new->flags, new->name, old->flags, old->name);
1455 #ifdef CONFIG_DEBUG_SHIRQ
1456                 dump_stack();
1457 #endif
1458         }
1459         ret = -EBUSY;
1460 
1461 out_unlock:
1462         raw_spin_unlock_irqrestore(&desc->lock, flags);
1463 
1464         if (!desc->action)
1465                 irq_release_resources(desc);
1466 out_bus_unlock:
1467         chip_bus_sync_unlock(desc);
1468         mutex_unlock(&desc->request_mutex);
1469 
1470 out_thread:
1471         if (new->thread) {
1472                 struct task_struct *t = new->thread;
1473 
1474                 new->thread = NULL;
1475                 kthread_stop(t);
1476                 put_task_struct(t);
1477         }
1478         if (new->secondary && new->secondary->thread) {
1479                 struct task_struct *t = new->secondary->thread;
1480 
1481                 new->secondary->thread = NULL;
1482                 kthread_stop(t);
1483                 put_task_struct(t);
1484         }
1485 out_mput:
1486         module_put(desc->owner);
1487         return ret;
1488 }
1489 
1490 /**
1491  *      setup_irq - setup an interrupt
1492  *      @irq: Interrupt line to setup
1493  *      @act: irqaction for the interrupt
1494  *
1495  * Used to statically setup interrupts in the early boot process.
1496  */
1497 int setup_irq(unsigned int irq, struct irqaction *act)
1498 {
1499         int retval;
1500         struct irq_desc *desc = irq_to_desc(irq);
1501 
1502         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1503                 return -EINVAL;
1504 
1505         retval = irq_chip_pm_get(&desc->irq_data);
1506         if (retval < 0)
1507                 return retval;
1508 
1509         retval = __setup_irq(irq, desc, act);
1510 
1511         if (retval)
1512                 irq_chip_pm_put(&desc->irq_data);
1513 
1514         return retval;
1515 }
1516 EXPORT_SYMBOL_GPL(setup_irq);
1517 
1518 /*
1519  * Internal function to unregister an irqaction - used to free
1520  * regular and special interrupts that are part of the architecture.
1521  */
1522 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1523 {
1524         struct irq_desc *desc = irq_to_desc(irq);
1525         struct irqaction *action, **action_ptr;
1526         unsigned long flags;
1527 
1528         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1529 
1530         if (!desc)
1531                 return NULL;
1532 
1533         mutex_lock(&desc->request_mutex);
1534         chip_bus_lock(desc);
1535         raw_spin_lock_irqsave(&desc->lock, flags);
1536 
1537         /*
1538          * There can be multiple actions per IRQ descriptor, find the right
1539          * one based on the dev_id:
1540          */
1541         action_ptr = &desc->action;
1542         for (;;) {
1543                 action = *action_ptr;
1544 
1545                 if (!action) {
1546                         WARN(1, "Trying to free already-free IRQ %d\n", irq);
1547                         raw_spin_unlock_irqrestore(&desc->lock, flags);
1548                         chip_bus_sync_unlock(desc);
1549                         mutex_unlock(&desc->request_mutex);
1550                         return NULL;
1551                 }
1552 
1553                 if (action->dev_id == dev_id)
1554                         break;
1555                 action_ptr = &action->next;
1556         }
1557 
1558         /* Found it - now remove it from the list of entries: */
1559         *action_ptr = action->next;
1560 
1561         irq_pm_remove_action(desc, action);
1562 
1563         /* If this was the last handler, shut down the IRQ line: */
1564         if (!desc->action) {
1565                 irq_settings_clr_disable_unlazy(desc);
1566                 irq_shutdown(desc);
1567         }
1568 
1569 #ifdef CONFIG_SMP
1570         /* make sure affinity_hint is cleaned up */
1571         if (WARN_ON_ONCE(desc->affinity_hint))
1572                 desc->affinity_hint = NULL;
1573 #endif
1574 
1575         raw_spin_unlock_irqrestore(&desc->lock, flags);
1576         /*
1577          * Drop bus_lock here so the changes which were done in the chip
1578          * callbacks above are synced out to the irq chips which hang
1579          * behind a slow bus (I2C, SPI) before calling synchronize_irq().
1580          *
1581          * Aside of that the bus_lock can also be taken from the threaded
1582          * handler in irq_finalize_oneshot() which results in a deadlock
1583          * because synchronize_irq() would wait forever for the thread to
1584          * complete, which is blocked on the bus lock.
1585          *
1586          * The still held desc->request_mutex() protects against a
1587          * concurrent request_irq() of this irq so the release of resources
1588          * and timing data is properly serialized.
1589          */
1590         chip_bus_sync_unlock(desc);
1591 
1592         unregister_handler_proc(irq, action);
1593 
1594         /* Make sure it's not being used on another CPU: */
1595         synchronize_irq(irq);
1596 
1597 #ifdef CONFIG_DEBUG_SHIRQ
1598         /*
1599          * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1600          * event to happen even now it's being freed, so let's make sure that
1601          * is so by doing an extra call to the handler ....
1602          *
1603          * ( We do this after actually deregistering it, to make sure that a
1604          *   'real' IRQ doesn't run in * parallel with our fake. )
1605          */
1606         if (action->flags & IRQF_SHARED) {
1607                 local_irq_save(flags);
1608                 action->handler(irq, dev_id);
1609                 local_irq_restore(flags);
1610         }
1611 #endif
1612 
1613         if (action->thread) {
1614                 kthread_stop(action->thread);
1615                 put_task_struct(action->thread);
1616                 if (action->secondary && action->secondary->thread) {
1617                         kthread_stop(action->secondary->thread);
1618                         put_task_struct(action->secondary->thread);
1619                 }
1620         }
1621 
1622         /* Last action releases resources */
1623         if (!desc->action) {
1624                 /*
1625                  * Reaquire bus lock as irq_release_resources() might
1626                  * require it to deallocate resources over the slow bus.
1627                  */
1628                 chip_bus_lock(desc);
1629                 irq_release_resources(desc);
1630                 chip_bus_sync_unlock(desc);
1631                 irq_remove_timings(desc);
1632         }
1633 
1634         mutex_unlock(&desc->request_mutex);
1635 
1636         irq_chip_pm_put(&desc->irq_data);
1637         module_put(desc->owner);
1638         kfree(action->secondary);
1639         return action;
1640 }
1641 
1642 /**
1643  *      remove_irq - free an interrupt
1644  *      @irq: Interrupt line to free
1645  *      @act: irqaction for the interrupt
1646  *
1647  * Used to remove interrupts statically setup by the early boot process.
1648  */
1649 void remove_irq(unsigned int irq, struct irqaction *act)
1650 {
1651         struct irq_desc *desc = irq_to_desc(irq);
1652 
1653         if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1654                 __free_irq(irq, act->dev_id);
1655 }
1656 EXPORT_SYMBOL_GPL(remove_irq);
1657 
1658 /**
1659  *      free_irq - free an interrupt allocated with request_irq
1660  *      @irq: Interrupt line to free
1661  *      @dev_id: Device identity to free
1662  *
1663  *      Remove an interrupt handler. The handler is removed and if the
1664  *      interrupt line is no longer in use by any driver it is disabled.
1665  *      On a shared IRQ the caller must ensure the interrupt is disabled
1666  *      on the card it drives before calling this function. The function
1667  *      does not return until any executing interrupts for this IRQ
1668  *      have completed.
1669  *
1670  *      This function must not be called from interrupt context.
1671  *
1672  *      Returns the devname argument passed to request_irq.
1673  */
1674 const void *free_irq(unsigned int irq, void *dev_id)
1675 {
1676         struct irq_desc *desc = irq_to_desc(irq);
1677         struct irqaction *action;
1678         const char *devname;
1679 
1680         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1681                 return NULL;
1682 
1683 #ifdef CONFIG_SMP
1684         if (WARN_ON(desc->affinity_notify))
1685                 desc->affinity_notify = NULL;
1686 #endif
1687 
1688         action = __free_irq(irq, dev_id);
1689 
1690         if (!action)
1691                 return NULL;
1692 
1693         devname = action->name;
1694         kfree(action);
1695         return devname;
1696 }
1697 EXPORT_SYMBOL(free_irq);
1698 
1699 /**
1700  *      request_threaded_irq - allocate an interrupt line
1701  *      @irq: Interrupt line to allocate
1702  *      @handler: Function to be called when the IRQ occurs.
1703  *                Primary handler for threaded interrupts
1704  *                If NULL and thread_fn != NULL the default
1705  *                primary handler is installed
1706  *      @thread_fn: Function called from the irq handler thread
1707  *                  If NULL, no irq thread is created
1708  *      @irqflags: Interrupt type flags
1709  *      @devname: An ascii name for the claiming device
1710  *      @dev_id: A cookie passed back to the handler function
1711  *
1712  *      This call allocates interrupt resources and enables the
1713  *      interrupt line and IRQ handling. From the point this
1714  *      call is made your handler function may be invoked. Since
1715  *      your handler function must clear any interrupt the board
1716  *      raises, you must take care both to initialise your hardware
1717  *      and to set up the interrupt handler in the right order.
1718  *
1719  *      If you want to set up a threaded irq handler for your device
1720  *      then you need to supply @handler and @thread_fn. @handler is
1721  *      still called in hard interrupt context and has to check
1722  *      whether the interrupt originates from the device. If yes it
1723  *      needs to disable the interrupt on the device and return
1724  *      IRQ_WAKE_THREAD which will wake up the handler thread and run
1725  *      @thread_fn. This split handler design is necessary to support
1726  *      shared interrupts.
1727  *
1728  *      Dev_id must be globally unique. Normally the address of the
1729  *      device data structure is used as the cookie. Since the handler
1730  *      receives this value it makes sense to use it.
1731  *
1732  *      If your interrupt is shared you must pass a non NULL dev_id
1733  *      as this is required when freeing the interrupt.
1734  *
1735  *      Flags:
1736  *
1737  *      IRQF_SHARED             Interrupt is shared
1738  *      IRQF_TRIGGER_*          Specify active edge(s) or level
1739  *
1740  */
1741 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1742                          irq_handler_t thread_fn, unsigned long irqflags,
1743                          const char *devname, void *dev_id)
1744 {
1745         struct irqaction *action;
1746         struct irq_desc *desc;
1747         int retval;
1748 
1749         if (irq == IRQ_NOTCONNECTED)
1750                 return -ENOTCONN;
1751 
1752         /*
1753          * Sanity-check: shared interrupts must pass in a real dev-ID,
1754          * otherwise we'll have trouble later trying to figure out
1755          * which interrupt is which (messes up the interrupt freeing
1756          * logic etc).
1757          *
1758          * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1759          * it cannot be set along with IRQF_NO_SUSPEND.
1760          */
1761         if (((irqflags & IRQF_SHARED) && !dev_id) ||
1762             (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1763             ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1764                 return -EINVAL;
1765 
1766         desc = irq_to_desc(irq);
1767         if (!desc)
1768                 return -EINVAL;
1769 
1770         if (!irq_settings_can_request(desc) ||
1771             WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1772                 return -EINVAL;
1773 
1774         if (!handler) {
1775                 if (!thread_fn)
1776                         return -EINVAL;
1777                 handler = irq_default_primary_handler;
1778         }
1779 
1780         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1781         if (!action)
1782                 return -ENOMEM;
1783 
1784         action->handler = handler;
1785         action->thread_fn = thread_fn;
1786         action->flags = irqflags;
1787         action->name = devname;
1788         action->dev_id = dev_id;
1789 
1790         retval = irq_chip_pm_get(&desc->irq_data);
1791         if (retval < 0) {
1792                 kfree(action);
1793                 return retval;
1794         }
1795 
1796         retval = __setup_irq(irq, desc, action);
1797 
1798         if (retval) {
1799                 irq_chip_pm_put(&desc->irq_data);
1800                 kfree(action->secondary);
1801                 kfree(action);
1802         }
1803 
1804 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1805         if (!retval && (irqflags & IRQF_SHARED)) {
1806                 /*
1807                  * It's a shared IRQ -- the driver ought to be prepared for it
1808                  * to happen immediately, so let's make sure....
1809                  * We disable the irq to make sure that a 'real' IRQ doesn't
1810                  * run in parallel with our fake.
1811                  */
1812                 unsigned long flags;
1813 
1814                 disable_irq(irq);
1815                 local_irq_save(flags);
1816 
1817                 handler(irq, dev_id);
1818 
1819                 local_irq_restore(flags);
1820                 enable_irq(irq);
1821         }
1822 #endif
1823         return retval;
1824 }
1825 EXPORT_SYMBOL(request_threaded_irq);
1826 
1827 /**
1828  *      request_any_context_irq - allocate an interrupt line
1829  *      @irq: Interrupt line to allocate
1830  *      @handler: Function to be called when the IRQ occurs.
1831  *                Threaded handler for threaded interrupts.
1832  *      @flags: Interrupt type flags
1833  *      @name: An ascii name for the claiming device
1834  *      @dev_id: A cookie passed back to the handler function
1835  *
1836  *      This call allocates interrupt resources and enables the
1837  *      interrupt line and IRQ handling. It selects either a
1838  *      hardirq or threaded handling method depending on the
1839  *      context.
1840  *
1841  *      On failure, it returns a negative value. On success,
1842  *      it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1843  */
1844 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1845                             unsigned long flags, const char *name, void *dev_id)
1846 {
1847         struct irq_desc *desc;
1848         int ret;
1849 
1850         if (irq == IRQ_NOTCONNECTED)
1851                 return -ENOTCONN;
1852 
1853         desc = irq_to_desc(irq);
1854         if (!desc)
1855                 return -EINVAL;
1856 
1857         if (irq_settings_is_nested_thread(desc)) {
1858                 ret = request_threaded_irq(irq, NULL, handler,
1859                                            flags, name, dev_id);
1860                 return !ret ? IRQC_IS_NESTED : ret;
1861         }
1862 
1863         ret = request_irq(irq, handler, flags, name, dev_id);
1864         return !ret ? IRQC_IS_HARDIRQ : ret;
1865 }
1866 EXPORT_SYMBOL_GPL(request_any_context_irq);
1867 
1868 void enable_percpu_irq(unsigned int irq, unsigned int type)
1869 {
1870         unsigned int cpu = smp_processor_id();
1871         unsigned long flags;
1872         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1873 
1874         if (!desc)
1875                 return;
1876 
1877         /*
1878          * If the trigger type is not specified by the caller, then
1879          * use the default for this interrupt.
1880          */
1881         type &= IRQ_TYPE_SENSE_MASK;
1882         if (type == IRQ_TYPE_NONE)
1883                 type = irqd_get_trigger_type(&desc->irq_data);
1884 
1885         if (type != IRQ_TYPE_NONE) {
1886                 int ret;
1887 
1888                 ret = __irq_set_trigger(desc, type);
1889 
1890                 if (ret) {
1891                         WARN(1, "failed to set type for IRQ%d\n", irq);
1892                         goto out;
1893                 }
1894         }
1895 
1896         irq_percpu_enable(desc, cpu);
1897 out:
1898         irq_put_desc_unlock(desc, flags);
1899 }
1900 EXPORT_SYMBOL_GPL(enable_percpu_irq);
1901 
1902 /**
1903  * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1904  * @irq:        Linux irq number to check for
1905  *
1906  * Must be called from a non migratable context. Returns the enable
1907  * state of a per cpu interrupt on the current cpu.
1908  */
1909 bool irq_percpu_is_enabled(unsigned int irq)
1910 {
1911         unsigned int cpu = smp_processor_id();
1912         struct irq_desc *desc;
1913         unsigned long flags;
1914         bool is_enabled;
1915 
1916         desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1917         if (!desc)
1918                 return false;
1919 
1920         is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1921         irq_put_desc_unlock(desc, flags);
1922 
1923         return is_enabled;
1924 }
1925 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1926 
1927 void disable_percpu_irq(unsigned int irq)
1928 {
1929         unsigned int cpu = smp_processor_id();
1930         unsigned long flags;
1931         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1932 
1933         if (!desc)
1934                 return;
1935 
1936         irq_percpu_disable(desc, cpu);
1937         irq_put_desc_unlock(desc, flags);
1938 }
1939 EXPORT_SYMBOL_GPL(disable_percpu_irq);
1940 
1941 /*
1942  * Internal function to unregister a percpu irqaction.
1943  */
1944 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1945 {
1946         struct irq_desc *desc = irq_to_desc(irq);
1947         struct irqaction *action;
1948         unsigned long flags;
1949 
1950         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1951 
1952         if (!desc)
1953                 return NULL;
1954 
1955         raw_spin_lock_irqsave(&desc->lock, flags);
1956 
1957         action = desc->action;
1958         if (!action || action->percpu_dev_id != dev_id) {
1959                 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1960                 goto bad;
1961         }
1962 
1963         if (!cpumask_empty(desc->percpu_enabled)) {
1964                 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1965                      irq, cpumask_first(desc->percpu_enabled));
1966                 goto bad;
1967         }
1968 
1969         /* Found it - now remove it from the list of entries: */
1970         desc->action = NULL;
1971 
1972         raw_spin_unlock_irqrestore(&desc->lock, flags);
1973 
1974         unregister_handler_proc(irq, action);
1975 
1976         irq_chip_pm_put(&desc->irq_data);
1977         module_put(desc->owner);
1978         return action;
1979 
1980 bad:
1981         raw_spin_unlock_irqrestore(&desc->lock, flags);
1982         return NULL;
1983 }
1984 
1985 /**
1986  *      remove_percpu_irq - free a per-cpu interrupt
1987  *      @irq: Interrupt line to free
1988  *      @act: irqaction for the interrupt
1989  *
1990  * Used to remove interrupts statically setup by the early boot process.
1991  */
1992 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1993 {
1994         struct irq_desc *desc = irq_to_desc(irq);
1995 
1996         if (desc && irq_settings_is_per_cpu_devid(desc))
1997             __free_percpu_irq(irq, act->percpu_dev_id);
1998 }
1999 
2000 /**
2001  *      free_percpu_irq - free an interrupt allocated with request_percpu_irq
2002  *      @irq: Interrupt line to free
2003  *      @dev_id: Device identity to free
2004  *
2005  *      Remove a percpu interrupt handler. The handler is removed, but
2006  *      the interrupt line is not disabled. This must be done on each
2007  *      CPU before calling this function. The function does not return
2008  *      until any executing interrupts for this IRQ have completed.
2009  *
2010  *      This function must not be called from interrupt context.
2011  */
2012 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
2013 {
2014         struct irq_desc *desc = irq_to_desc(irq);
2015 
2016         if (!desc || !irq_settings_is_per_cpu_devid(desc))
2017                 return;
2018 
2019         chip_bus_lock(desc);
2020         kfree(__free_percpu_irq(irq, dev_id));
2021         chip_bus_sync_unlock(desc);
2022 }
2023 EXPORT_SYMBOL_GPL(free_percpu_irq);
2024 
2025 /**
2026  *      setup_percpu_irq - setup a per-cpu interrupt
2027  *      @irq: Interrupt line to setup
2028  *      @act: irqaction for the interrupt
2029  *
2030  * Used to statically setup per-cpu interrupts in the early boot process.
2031  */
2032 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
2033 {
2034         struct irq_desc *desc = irq_to_desc(irq);
2035         int retval;
2036 
2037         if (!desc || !irq_settings_is_per_cpu_devid(desc))
2038                 return -EINVAL;
2039 
2040         retval = irq_chip_pm_get(&desc->irq_data);
2041         if (retval < 0)
2042                 return retval;
2043 
2044         retval = __setup_irq(irq, desc, act);
2045 
2046         if (retval)
2047                 irq_chip_pm_put(&desc->irq_data);
2048 
2049         return retval;
2050 }
2051 
2052 /**
2053  *      __request_percpu_irq - allocate a percpu interrupt line
2054  *      @irq: Interrupt line to allocate
2055  *      @handler: Function to be called when the IRQ occurs.
2056  *      @flags: Interrupt type flags (IRQF_TIMER only)
2057  *      @devname: An ascii name for the claiming device
2058  *      @dev_id: A percpu cookie passed back to the handler function
2059  *
2060  *      This call allocates interrupt resources and enables the
2061  *      interrupt on the local CPU. If the interrupt is supposed to be
2062  *      enabled on other CPUs, it has to be done on each CPU using
2063  *      enable_percpu_irq().
2064  *
2065  *      Dev_id must be globally unique. It is a per-cpu variable, and
2066  *      the handler gets called with the interrupted CPU's instance of
2067  *      that variable.
2068  */
2069 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
2070                          unsigned long flags, const char *devname,
2071                          void __percpu *dev_id)
2072 {
2073         struct irqaction *action;
2074         struct irq_desc *desc;
2075         int retval;
2076 
2077         if (!dev_id)
2078                 return -EINVAL;
2079 
2080         desc = irq_to_desc(irq);
2081         if (!desc || !irq_settings_can_request(desc) ||
2082             !irq_settings_is_per_cpu_devid(desc))
2083                 return -EINVAL;
2084 
2085         if (flags && flags != IRQF_TIMER)
2086                 return -EINVAL;
2087 
2088         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
2089         if (!action)
2090                 return -ENOMEM;
2091 
2092         action->handler = handler;
2093         action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
2094         action->name = devname;
2095         action->percpu_dev_id = dev_id;
2096 
2097         retval = irq_chip_pm_get(&desc->irq_data);
2098         if (retval < 0) {
2099                 kfree(action);
2100                 return retval;
2101         }
2102 
2103         retval = __setup_irq(irq, desc, action);
2104 
2105         if (retval) {
2106                 irq_chip_pm_put(&desc->irq_data);
2107                 kfree(action);
2108         }
2109 
2110         return retval;
2111 }
2112 EXPORT_SYMBOL_GPL(__request_percpu_irq);
2113 
2114 /**
2115  *      irq_get_irqchip_state - returns the irqchip state of a interrupt.
2116  *      @irq: Interrupt line that is forwarded to a VM
2117  *      @which: One of IRQCHIP_STATE_* the caller wants to know about
2118  *      @state: a pointer to a boolean where the state is to be storeed
2119  *
2120  *      This call snapshots the internal irqchip state of an
2121  *      interrupt, returning into @state the bit corresponding to
2122  *      stage @which
2123  *
2124  *      This function should be called with preemption disabled if the
2125  *      interrupt controller has per-cpu registers.
2126  */
2127 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2128                           bool *state)
2129 {
2130         struct irq_desc *desc;
2131         struct irq_data *data;
2132         struct irq_chip *chip;
2133         unsigned long flags;
2134         int err = -EINVAL;
2135 
2136         desc = irq_get_desc_buslock(irq, &flags, 0);
2137         if (!desc)
2138                 return err;
2139 
2140         data = irq_desc_get_irq_data(desc);
2141 
2142         do {
2143                 chip = irq_data_get_irq_chip(data);
2144                 if (chip->irq_get_irqchip_state)
2145                         break;
2146 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2147                 data = data->parent_data;
2148 #else
2149                 data = NULL;
2150 #endif
2151         } while (data);
2152 
2153         if (data)
2154                 err = chip->irq_get_irqchip_state(data, which, state);
2155 
2156         irq_put_desc_busunlock(desc, flags);
2157         return err;
2158 }
2159 EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2160 
2161 /**
2162  *      irq_set_irqchip_state - set the state of a forwarded interrupt.
2163  *      @irq: Interrupt line that is forwarded to a VM
2164  *      @which: State to be restored (one of IRQCHIP_STATE_*)
2165  *      @val: Value corresponding to @which
2166  *
2167  *      This call sets the internal irqchip state of an interrupt,
2168  *      depending on the value of @which.
2169  *
2170  *      This function should be called with preemption disabled if the
2171  *      interrupt controller has per-cpu registers.
2172  */
2173 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2174                           bool val)
2175 {
2176         struct irq_desc *desc;
2177         struct irq_data *data;
2178         struct irq_chip *chip;
2179         unsigned long flags;
2180         int err = -EINVAL;
2181 
2182         desc = irq_get_desc_buslock(irq, &flags, 0);
2183         if (!desc)
2184                 return err;
2185 
2186         data = irq_desc_get_irq_data(desc);
2187 
2188         do {
2189                 chip = irq_data_get_irq_chip(data);
2190                 if (chip->irq_set_irqchip_state)
2191                         break;
2192 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2193                 data = data->parent_data;
2194 #else
2195                 data = NULL;
2196 #endif
2197         } while (data);
2198 
2199         if (data)
2200                 err = chip->irq_set_irqchip_state(data, which, val);
2201 
2202         irq_put_desc_busunlock(desc, flags);
2203         return err;
2204 }
2205 EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2206 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp