arm: tegra: cardhu/enterprise: Remove pinmux conflicts
[linux-2.6.git] / 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 #include <linux/irq.h>
11 #include <linux/kthread.h>
12 #include <linux/module.h>
13 #include <linux/random.h>
14 #include <linux/interrupt.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
17
18 #include "internals.h"
19
20 #ifdef CONFIG_IRQ_FORCED_THREADING
21 __read_mostly bool force_irqthreads;
22
23 static int __init setup_forced_irqthreads(char *arg)
24 {
25         force_irqthreads = true;
26         return 0;
27 }
28 early_param("threadirqs", setup_forced_irqthreads);
29 #endif
30
31 /**
32  *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
33  *      @irq: interrupt number to wait for
34  *
35  *      This function waits for any pending IRQ handlers for this interrupt
36  *      to complete before returning. If you use this function while
37  *      holding a resource the IRQ handler may need you will deadlock.
38  *
39  *      This function may be called - with care - from IRQ context.
40  */
41 void synchronize_irq(unsigned int irq)
42 {
43         struct irq_desc *desc = irq_to_desc(irq);
44         bool inprogress;
45
46         if (!desc)
47                 return;
48
49         do {
50                 unsigned long flags;
51
52                 /*
53                  * Wait until we're out of the critical section.  This might
54                  * give the wrong answer due to the lack of memory barriers.
55                  */
56                 while (irqd_irq_inprogress(&desc->irq_data))
57                         cpu_relax();
58
59                 /* Ok, that indicated we're done: double-check carefully. */
60                 raw_spin_lock_irqsave(&desc->lock, flags);
61                 inprogress = irqd_irq_inprogress(&desc->irq_data);
62                 raw_spin_unlock_irqrestore(&desc->lock, flags);
63
64                 /* Oops, that failed? */
65         } while (inprogress);
66
67         /*
68          * We made sure that no hardirq handler is running. Now verify
69          * that no threaded handlers are active.
70          */
71         wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
72 }
73 EXPORT_SYMBOL(synchronize_irq);
74
75 #ifdef CONFIG_SMP
76 cpumask_var_t irq_default_affinity;
77
78 /**
79  *      irq_can_set_affinity - Check if the affinity of a given irq can be set
80  *      @irq:           Interrupt to check
81  *
82  */
83 int irq_can_set_affinity(unsigned int irq)
84 {
85         struct irq_desc *desc = irq_to_desc(irq);
86
87         if (!desc || !irqd_can_balance(&desc->irq_data) ||
88             !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
89                 return 0;
90
91         return 1;
92 }
93
94 /**
95  *      irq_set_thread_affinity - Notify irq threads to adjust affinity
96  *      @desc:          irq descriptor which has affitnity changed
97  *
98  *      We just set IRQTF_AFFINITY and delegate the affinity setting
99  *      to the interrupt thread itself. We can not call
100  *      set_cpus_allowed_ptr() here as we hold desc->lock and this
101  *      code can be called from hard interrupt context.
102  */
103 void irq_set_thread_affinity(struct irq_desc *desc)
104 {
105         struct irqaction *action = desc->action;
106
107         while (action) {
108                 if (action->thread)
109                         set_bit(IRQTF_AFFINITY, &action->thread_flags);
110                 action = action->next;
111         }
112 }
113
114 #ifdef CONFIG_GENERIC_PENDING_IRQ
115 static inline bool irq_can_move_pcntxt(struct irq_data *data)
116 {
117         return irqd_can_move_in_process_context(data);
118 }
119 static inline bool irq_move_pending(struct irq_data *data)
120 {
121         return irqd_is_setaffinity_pending(data);
122 }
123 static inline void
124 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
125 {
126         cpumask_copy(desc->pending_mask, mask);
127 }
128 static inline void
129 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
130 {
131         cpumask_copy(mask, desc->pending_mask);
132 }
133 #else
134 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
135 static inline bool irq_move_pending(struct irq_data *data) { return false; }
136 static inline void
137 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
138 static inline void
139 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
140 #endif
141
142 int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
143 {
144         struct irq_chip *chip = irq_data_get_irq_chip(data);
145         struct irq_desc *desc = irq_data_to_desc(data);
146         int ret = 0;
147
148         if (!chip || !chip->irq_set_affinity)
149                 return -EINVAL;
150
151         if (irq_can_move_pcntxt(data)) {
152                 ret = chip->irq_set_affinity(data, mask, false);
153                 switch (ret) {
154                 case IRQ_SET_MASK_OK:
155                         cpumask_copy(data->affinity, mask);
156                 case IRQ_SET_MASK_OK_NOCOPY:
157                         irq_set_thread_affinity(desc);
158                         ret = 0;
159                 }
160         } else {
161                 irqd_set_move_pending(data);
162                 irq_copy_pending(desc, mask);
163         }
164
165         if (desc->affinity_notify) {
166                 kref_get(&desc->affinity_notify->kref);
167                 schedule_work(&desc->affinity_notify->work);
168         }
169         irqd_set(data, IRQD_AFFINITY_SET);
170
171         return ret;
172 }
173
174 /**
175  *      irq_set_affinity - Set the irq affinity of a given irq
176  *      @irq:           Interrupt to set affinity
177  *      @mask:          cpumask
178  *
179  */
180 int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
181 {
182         struct irq_desc *desc = irq_to_desc(irq);
183         unsigned long flags;
184         int ret;
185
186         if (!desc)
187                 return -EINVAL;
188
189         raw_spin_lock_irqsave(&desc->lock, flags);
190         ret =  __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask);
191         raw_spin_unlock_irqrestore(&desc->lock, flags);
192         return ret;
193 }
194
195 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
196 {
197         unsigned long flags;
198         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
199
200         if (!desc)
201                 return -EINVAL;
202         desc->affinity_hint = m;
203         irq_put_desc_unlock(desc, flags);
204         return 0;
205 }
206 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
207
208 static void irq_affinity_notify(struct work_struct *work)
209 {
210         struct irq_affinity_notify *notify =
211                 container_of(work, struct irq_affinity_notify, work);
212         struct irq_desc *desc = irq_to_desc(notify->irq);
213         cpumask_var_t cpumask;
214         unsigned long flags;
215
216         if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
217                 goto out;
218
219         raw_spin_lock_irqsave(&desc->lock, flags);
220         if (irq_move_pending(&desc->irq_data))
221                 irq_get_pending(cpumask, desc);
222         else
223                 cpumask_copy(cpumask, desc->irq_data.affinity);
224         raw_spin_unlock_irqrestore(&desc->lock, flags);
225
226         notify->notify(notify, cpumask);
227
228         free_cpumask_var(cpumask);
229 out:
230         kref_put(&notify->kref, notify->release);
231 }
232
233 /**
234  *      irq_set_affinity_notifier - control notification of IRQ affinity changes
235  *      @irq:           Interrupt for which to enable/disable notification
236  *      @notify:        Context for notification, or %NULL to disable
237  *                      notification.  Function pointers must be initialised;
238  *                      the other fields will be initialised by this function.
239  *
240  *      Must be called in process context.  Notification may only be enabled
241  *      after the IRQ is allocated and must be disabled before the IRQ is
242  *      freed using free_irq().
243  */
244 int
245 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
246 {
247         struct irq_desc *desc = irq_to_desc(irq);
248         struct irq_affinity_notify *old_notify;
249         unsigned long flags;
250
251         /* The release function is promised process context */
252         might_sleep();
253
254         if (!desc)
255                 return -EINVAL;
256
257         /* Complete initialisation of *notify */
258         if (notify) {
259                 notify->irq = irq;
260                 kref_init(&notify->kref);
261                 INIT_WORK(&notify->work, irq_affinity_notify);
262         }
263
264         raw_spin_lock_irqsave(&desc->lock, flags);
265         old_notify = desc->affinity_notify;
266         desc->affinity_notify = notify;
267         raw_spin_unlock_irqrestore(&desc->lock, flags);
268
269         if (old_notify)
270                 kref_put(&old_notify->kref, old_notify->release);
271
272         return 0;
273 }
274 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
275
276 #ifndef CONFIG_AUTO_IRQ_AFFINITY
277 /*
278  * Generic version of the affinity autoselector.
279  */
280 static int
281 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
282 {
283         struct irq_chip *chip = irq_desc_get_chip(desc);
284         struct cpumask *set = irq_default_affinity;
285         int ret;
286
287         /* Excludes PER_CPU and NO_BALANCE interrupts */
288         if (!irq_can_set_affinity(irq))
289                 return 0;
290
291         /*
292          * Preserve an userspace affinity setup, but make sure that
293          * one of the targets is online.
294          */
295         if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
296                 if (cpumask_intersects(desc->irq_data.affinity,
297                                        cpu_online_mask))
298                         set = desc->irq_data.affinity;
299                 else
300                         irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
301         }
302
303         cpumask_and(mask, cpu_online_mask, set);
304         ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
305         switch (ret) {
306         case IRQ_SET_MASK_OK:
307                 cpumask_copy(desc->irq_data.affinity, mask);
308         case IRQ_SET_MASK_OK_NOCOPY:
309                 irq_set_thread_affinity(desc);
310         }
311         return 0;
312 }
313 #else
314 static inline int
315 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
316 {
317         return irq_select_affinity(irq);
318 }
319 #endif
320
321 /*
322  * Called when affinity is set via /proc/irq
323  */
324 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
325 {
326         struct irq_desc *desc = irq_to_desc(irq);
327         unsigned long flags;
328         int ret;
329
330         raw_spin_lock_irqsave(&desc->lock, flags);
331         ret = setup_affinity(irq, desc, mask);
332         raw_spin_unlock_irqrestore(&desc->lock, flags);
333         return ret;
334 }
335
336 #else
337 static inline int
338 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
339 {
340         return 0;
341 }
342 #endif
343
344 void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
345 {
346         if (suspend) {
347                 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
348                         return;
349                 desc->istate |= IRQS_SUSPENDED;
350         }
351
352         if (!desc->depth++)
353                 irq_disable(desc);
354 }
355
356 static int __disable_irq_nosync(unsigned int irq)
357 {
358         unsigned long flags;
359         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
360
361         if (!desc)
362                 return -EINVAL;
363         __disable_irq(desc, irq, false);
364         irq_put_desc_busunlock(desc, flags);
365         return 0;
366 }
367
368 /**
369  *      disable_irq_nosync - disable an irq without waiting
370  *      @irq: Interrupt to disable
371  *
372  *      Disable the selected interrupt line.  Disables and Enables are
373  *      nested.
374  *      Unlike disable_irq(), this function does not ensure existing
375  *      instances of the IRQ handler have completed before returning.
376  *
377  *      This function may be called from IRQ context.
378  */
379 void disable_irq_nosync(unsigned int irq)
380 {
381         __disable_irq_nosync(irq);
382 }
383 EXPORT_SYMBOL(disable_irq_nosync);
384
385 /**
386  *      disable_irq - disable an irq and wait for completion
387  *      @irq: Interrupt to disable
388  *
389  *      Disable the selected interrupt line.  Enables and Disables are
390  *      nested.
391  *      This function waits for any pending IRQ handlers for this interrupt
392  *      to complete before returning. If you use this function while
393  *      holding a resource the IRQ handler may need you will deadlock.
394  *
395  *      This function may be called - with care - from IRQ context.
396  */
397 void disable_irq(unsigned int irq)
398 {
399         if (!__disable_irq_nosync(irq))
400                 synchronize_irq(irq);
401 }
402 EXPORT_SYMBOL(disable_irq);
403
404 void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
405 {
406         if (resume) {
407                 if (!(desc->istate & IRQS_SUSPENDED)) {
408                         if (!desc->action)
409                                 return;
410                         if (!(desc->action->flags & IRQF_FORCE_RESUME))
411                                 return;
412                         /* Pretend that it got disabled ! */
413                         desc->depth++;
414                 }
415                 desc->istate &= ~IRQS_SUSPENDED;
416         }
417
418         switch (desc->depth) {
419         case 0:
420  err_out:
421                 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
422                 break;
423         case 1: {
424                 if (desc->istate & IRQS_SUSPENDED)
425                         goto err_out;
426                 /* Prevent probing on this irq: */
427                 irq_settings_set_noprobe(desc);
428                 irq_enable(desc);
429                 check_irq_resend(desc, irq);
430                 /* fall-through */
431         }
432         default:
433                 desc->depth--;
434         }
435 }
436
437 /**
438  *      enable_irq - enable handling of an irq
439  *      @irq: Interrupt to enable
440  *
441  *      Undoes the effect of one call to disable_irq().  If this
442  *      matches the last disable, processing of interrupts on this
443  *      IRQ line is re-enabled.
444  *
445  *      This function may be called from IRQ context only when
446  *      desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
447  */
448 void enable_irq(unsigned int irq)
449 {
450         unsigned long flags;
451         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
452
453         if (!desc)
454                 return;
455         if (WARN(!desc->irq_data.chip,
456                  KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
457                 goto out;
458
459         __enable_irq(desc, irq, false);
460 out:
461         irq_put_desc_busunlock(desc, flags);
462 }
463 EXPORT_SYMBOL(enable_irq);
464
465 static int set_irq_wake_real(unsigned int irq, unsigned int on)
466 {
467         struct irq_desc *desc = irq_to_desc(irq);
468         int ret = -ENXIO;
469
470         if (irq_desc_get_chip(desc)->flags &  IRQCHIP_SKIP_SET_WAKE)
471                 return 0;
472
473         if (desc->irq_data.chip->irq_set_wake)
474                 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
475
476         return ret;
477 }
478
479 /**
480  *      irq_set_irq_wake - control irq power management wakeup
481  *      @irq:   interrupt to control
482  *      @on:    enable/disable power management wakeup
483  *
484  *      Enable/disable power management wakeup mode, which is
485  *      disabled by default.  Enables and disables must match,
486  *      just as they match for non-wakeup mode support.
487  *
488  *      Wakeup mode lets this IRQ wake the system from sleep
489  *      states like "suspend to RAM".
490  */
491 int irq_set_irq_wake(unsigned int irq, unsigned int on)
492 {
493         unsigned long flags;
494         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
495         int ret = 0;
496
497         if (!desc)
498                 return -EINVAL;
499
500         /* wakeup-capable irqs can be shared between drivers that
501          * don't need to have the same sleep mode behaviors.
502          */
503         if (on) {
504                 if (desc->wake_depth++ == 0) {
505                         ret = set_irq_wake_real(irq, on);
506                         if (ret)
507                                 desc->wake_depth = 0;
508                         else
509                                 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
510                 }
511         } else {
512                 if (desc->wake_depth == 0) {
513                         WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
514                 } else if (--desc->wake_depth == 0) {
515                         ret = set_irq_wake_real(irq, on);
516                         if (ret)
517                                 desc->wake_depth = 1;
518                         else
519                                 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
520                 }
521         }
522         irq_put_desc_busunlock(desc, flags);
523         return ret;
524 }
525 EXPORT_SYMBOL(irq_set_irq_wake);
526
527 /*
528  * Internal function that tells the architecture code whether a
529  * particular irq has been exclusively allocated or is available
530  * for driver use.
531  */
532 int can_request_irq(unsigned int irq, unsigned long irqflags)
533 {
534         unsigned long flags;
535         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
536         int canrequest = 0;
537
538         if (!desc)
539                 return 0;
540
541         if (irq_settings_can_request(desc)) {
542                 if (desc->action)
543                         if (irqflags & desc->action->flags & IRQF_SHARED)
544                                 canrequest =1;
545         }
546         irq_put_desc_unlock(desc, flags);
547         return canrequest;
548 }
549
550 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
551                       unsigned long flags)
552 {
553         struct irq_chip *chip = desc->irq_data.chip;
554         int ret, unmask = 0;
555
556         if (!chip || !chip->irq_set_type) {
557                 /*
558                  * IRQF_TRIGGER_* but the PIC does not support multiple
559                  * flow-types?
560                  */
561                 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
562                                 chip ? (chip->name ? : "unknown") : "unknown");
563                 return 0;
564         }
565
566         flags &= IRQ_TYPE_SENSE_MASK;
567
568         if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
569                 if (!irqd_irq_masked(&desc->irq_data))
570                         mask_irq(desc);
571                 if (!irqd_irq_disabled(&desc->irq_data))
572                         unmask = 1;
573         }
574
575         /* caller masked out all except trigger mode flags */
576         ret = chip->irq_set_type(&desc->irq_data, flags);
577
578         switch (ret) {
579         case IRQ_SET_MASK_OK:
580                 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
581                 irqd_set(&desc->irq_data, flags);
582
583         case IRQ_SET_MASK_OK_NOCOPY:
584                 flags = irqd_get_trigger_type(&desc->irq_data);
585                 irq_settings_set_trigger_mask(desc, flags);
586                 irqd_clear(&desc->irq_data, IRQD_LEVEL);
587                 irq_settings_clr_level(desc);
588                 if (flags & IRQ_TYPE_LEVEL_MASK) {
589                         irq_settings_set_level(desc);
590                         irqd_set(&desc->irq_data, IRQD_LEVEL);
591                 }
592
593                 ret = 0;
594                 break;
595         default:
596                 pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
597                        flags, irq, chip->irq_set_type);
598         }
599         if (unmask)
600                 unmask_irq(desc);
601         return ret;
602 }
603
604 /*
605  * Default primary interrupt handler for threaded interrupts. Is
606  * assigned as primary handler when request_threaded_irq is called
607  * with handler == NULL. Useful for oneshot interrupts.
608  */
609 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
610 {
611         return IRQ_WAKE_THREAD;
612 }
613
614 /*
615  * Primary handler for nested threaded interrupts. Should never be
616  * called.
617  */
618 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
619 {
620         WARN(1, "Primary handler called for nested irq %d\n", irq);
621         return IRQ_NONE;
622 }
623
624 static int irq_wait_for_interrupt(struct irqaction *action)
625 {
626         set_current_state(TASK_INTERRUPTIBLE);
627
628         while (!kthread_should_stop()) {
629
630                 if (test_and_clear_bit(IRQTF_RUNTHREAD,
631                                        &action->thread_flags)) {
632                         __set_current_state(TASK_RUNNING);
633                         return 0;
634                 }
635                 schedule();
636                 set_current_state(TASK_INTERRUPTIBLE);
637         }
638         __set_current_state(TASK_RUNNING);
639         return -1;
640 }
641
642 /*
643  * Oneshot interrupts keep the irq line masked until the threaded
644  * handler finished. unmask if the interrupt has not been disabled and
645  * is marked MASKED.
646  */
647 static void irq_finalize_oneshot(struct irq_desc *desc,
648                                  struct irqaction *action, bool force)
649 {
650         if (!(desc->istate & IRQS_ONESHOT))
651                 return;
652 again:
653         chip_bus_lock(desc);
654         raw_spin_lock_irq(&desc->lock);
655
656         /*
657          * Implausible though it may be we need to protect us against
658          * the following scenario:
659          *
660          * The thread is faster done than the hard interrupt handler
661          * on the other CPU. If we unmask the irq line then the
662          * interrupt can come in again and masks the line, leaves due
663          * to IRQS_INPROGRESS and the irq line is masked forever.
664          *
665          * This also serializes the state of shared oneshot handlers
666          * versus "desc->threads_onehsot |= action->thread_mask;" in
667          * irq_wake_thread(). See the comment there which explains the
668          * serialization.
669          */
670         if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
671                 raw_spin_unlock_irq(&desc->lock);
672                 chip_bus_sync_unlock(desc);
673                 cpu_relax();
674                 goto again;
675         }
676
677         /*
678          * Now check again, whether the thread should run. Otherwise
679          * we would clear the threads_oneshot bit of this thread which
680          * was just set.
681          */
682         if (!force && test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
683                 goto out_unlock;
684
685         desc->threads_oneshot &= ~action->thread_mask;
686
687         if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
688             irqd_irq_masked(&desc->irq_data))
689                 unmask_irq(desc);
690
691 out_unlock:
692         raw_spin_unlock_irq(&desc->lock);
693         chip_bus_sync_unlock(desc);
694 }
695
696 #ifdef CONFIG_SMP
697 /*
698  * Check whether we need to chasnge the affinity of the interrupt thread.
699  */
700 static void
701 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
702 {
703         cpumask_var_t mask;
704
705         if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
706                 return;
707
708         /*
709          * In case we are out of memory we set IRQTF_AFFINITY again and
710          * try again next time
711          */
712         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
713                 set_bit(IRQTF_AFFINITY, &action->thread_flags);
714                 return;
715         }
716
717         raw_spin_lock_irq(&desc->lock);
718         cpumask_copy(mask, desc->irq_data.affinity);
719         raw_spin_unlock_irq(&desc->lock);
720
721         set_cpus_allowed_ptr(current, mask);
722         free_cpumask_var(mask);
723 }
724 #else
725 static inline void
726 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
727 #endif
728
729 /*
730  * Interrupts which are not explicitely requested as threaded
731  * interrupts rely on the implicit bh/preempt disable of the hard irq
732  * context. So we need to disable bh here to avoid deadlocks and other
733  * side effects.
734  */
735 static irqreturn_t
736 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
737 {
738         irqreturn_t ret;
739
740         local_bh_disable();
741         ret = action->thread_fn(action->irq, action->dev_id);
742         irq_finalize_oneshot(desc, action, false);
743         local_bh_enable();
744         return ret;
745 }
746
747 /*
748  * Interrupts explicitely requested as threaded interupts want to be
749  * preemtible - many of them need to sleep and wait for slow busses to
750  * complete.
751  */
752 static irqreturn_t irq_thread_fn(struct irq_desc *desc,
753                 struct irqaction *action)
754 {
755         irqreturn_t ret;
756
757         ret = action->thread_fn(action->irq, action->dev_id);
758         irq_finalize_oneshot(desc, action, false);
759         return ret;
760 }
761
762 /*
763  * Interrupt handler thread
764  */
765 static int irq_thread(void *data)
766 {
767         static const struct sched_param param = {
768                 .sched_priority = MAX_USER_RT_PRIO/2,
769         };
770         struct irqaction *action = data;
771         struct irq_desc *desc = irq_to_desc(action->irq);
772         irqreturn_t (*handler_fn)(struct irq_desc *desc,
773                         struct irqaction *action);
774         int wake;
775
776         if (force_irqthreads & test_bit(IRQTF_FORCED_THREAD,
777                                         &action->thread_flags))
778                 handler_fn = irq_forced_thread_fn;
779         else
780                 handler_fn = irq_thread_fn;
781
782         sched_setscheduler(current, SCHED_FIFO, &param);
783         current->irqaction = action;
784
785         while (!irq_wait_for_interrupt(action)) {
786
787                 irq_thread_check_affinity(desc, action);
788
789                 atomic_inc(&desc->threads_active);
790
791                 raw_spin_lock_irq(&desc->lock);
792                 if (unlikely(irqd_irq_disabled(&desc->irq_data))) {
793                         /*
794                          * CHECKME: We might need a dedicated
795                          * IRQ_THREAD_PENDING flag here, which
796                          * retriggers the thread in check_irq_resend()
797                          * but AFAICT IRQS_PENDING should be fine as it
798                          * retriggers the interrupt itself --- tglx
799                          */
800                         desc->istate |= IRQS_PENDING;
801                         raw_spin_unlock_irq(&desc->lock);
802                 } else {
803                         irqreturn_t action_ret;
804
805                         raw_spin_unlock_irq(&desc->lock);
806                         action_ret = handler_fn(desc, action);
807                         if (!noirqdebug)
808                                 note_interrupt(action->irq, desc, action_ret);
809                 }
810
811                 wake = atomic_dec_and_test(&desc->threads_active);
812
813                 if (wake && waitqueue_active(&desc->wait_for_threads))
814                         wake_up(&desc->wait_for_threads);
815         }
816
817         /* Prevent a stale desc->threads_oneshot */
818         irq_finalize_oneshot(desc, action, true);
819
820         /*
821          * Clear irqaction. Otherwise exit_irq_thread() would make
822          * fuzz about an active irq thread going into nirvana.
823          */
824         current->irqaction = NULL;
825         return 0;
826 }
827
828 /*
829  * Called from do_exit()
830  */
831 void exit_irq_thread(void)
832 {
833         struct task_struct *tsk = current;
834         struct irq_desc *desc;
835
836         if (!tsk->irqaction)
837                 return;
838
839         printk(KERN_ERR
840                "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
841                tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
842
843         desc = irq_to_desc(tsk->irqaction->irq);
844
845         /*
846          * Prevent a stale desc->threads_oneshot. Must be called
847          * before setting the IRQTF_DIED flag.
848          */
849         irq_finalize_oneshot(desc, tsk->irqaction, true);
850
851         /*
852          * Set the THREAD DIED flag to prevent further wakeups of the
853          * soon to be gone threaded handler.
854          */
855         set_bit(IRQTF_DIED, &tsk->irqaction->flags);
856 }
857
858 static void irq_setup_forced_threading(struct irqaction *new)
859 {
860         if (!force_irqthreads)
861                 return;
862         if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
863                 return;
864
865         new->flags |= IRQF_ONESHOT;
866
867         if (!new->thread_fn) {
868                 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
869                 new->thread_fn = new->handler;
870                 new->handler = irq_default_primary_handler;
871         }
872 }
873
874 /*
875  * Internal function to register an irqaction - typically used to
876  * allocate special interrupts that are part of the architecture.
877  */
878 static int
879 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
880 {
881         struct irqaction *old, **old_ptr;
882         const char *old_name = NULL;
883         unsigned long flags, thread_mask = 0;
884         int ret, nested, shared = 0;
885         cpumask_var_t mask;
886
887         if (!desc)
888                 return -EINVAL;
889
890         if (desc->irq_data.chip == &no_irq_chip)
891                 return -ENOSYS;
892         if (!try_module_get(desc->owner))
893                 return -ENODEV;
894         /*
895          * Some drivers like serial.c use request_irq() heavily,
896          * so we have to be careful not to interfere with a
897          * running system.
898          */
899         if (new->flags & IRQF_SAMPLE_RANDOM) {
900                 /*
901                  * This function might sleep, we want to call it first,
902                  * outside of the atomic block.
903                  * Yes, this might clear the entropy pool if the wrong
904                  * driver is attempted to be loaded, without actually
905                  * installing a new handler, but is this really a problem,
906                  * only the sysadmin is able to do this.
907                  */
908                 rand_initialize_irq(irq);
909         }
910
911         /*
912          * Check whether the interrupt nests into another interrupt
913          * thread.
914          */
915         nested = irq_settings_is_nested_thread(desc);
916         if (nested) {
917                 if (!new->thread_fn) {
918                         ret = -EINVAL;
919                         goto out_mput;
920                 }
921                 /*
922                  * Replace the primary handler which was provided from
923                  * the driver for non nested interrupt handling by the
924                  * dummy function which warns when called.
925                  */
926                 new->handler = irq_nested_primary_handler;
927         } else {
928                 if (irq_settings_can_thread(desc))
929                         irq_setup_forced_threading(new);
930         }
931
932         /*
933          * Create a handler thread when a thread function is supplied
934          * and the interrupt does not nest into another interrupt
935          * thread.
936          */
937         if (new->thread_fn && !nested) {
938                 struct task_struct *t;
939
940                 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
941                                    new->name);
942                 if (IS_ERR(t)) {
943                         ret = PTR_ERR(t);
944                         goto out_mput;
945                 }
946                 /*
947                  * We keep the reference to the task struct even if
948                  * the thread dies to avoid that the interrupt code
949                  * references an already freed task_struct.
950                  */
951                 get_task_struct(t);
952                 new->thread = t;
953         }
954
955         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
956                 ret = -ENOMEM;
957                 goto out_thread;
958         }
959
960         /*
961          * The following block of code has to be executed atomically
962          */
963         raw_spin_lock_irqsave(&desc->lock, flags);
964         old_ptr = &desc->action;
965         old = *old_ptr;
966         if (old) {
967                 /*
968                  * Can't share interrupts unless both agree to and are
969                  * the same type (level, edge, polarity). So both flag
970                  * fields must have IRQF_SHARED set and the bits which
971                  * set the trigger type must match. Also all must
972                  * agree on ONESHOT.
973                  */
974                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
975                     ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
976                     ((old->flags ^ new->flags) & IRQF_ONESHOT)) {
977                         old_name = old->name;
978                         goto mismatch;
979                 }
980
981                 /* All handlers must agree on per-cpuness */
982                 if ((old->flags & IRQF_PERCPU) !=
983                     (new->flags & IRQF_PERCPU))
984                         goto mismatch;
985
986                 /* add new interrupt at end of irq queue */
987                 do {
988                         /*
989                          * Or all existing action->thread_mask bits,
990                          * so we can find the next zero bit for this
991                          * new action.
992                          */
993                         thread_mask |= old->thread_mask;
994                         old_ptr = &old->next;
995                         old = *old_ptr;
996                 } while (old);
997                 shared = 1;
998         }
999
1000         /*
1001          * Setup the thread mask for this irqaction for ONESHOT. For
1002          * !ONESHOT irqs the thread mask is 0 so we can avoid a
1003          * conditional in irq_wake_thread().
1004          */
1005         if (new->flags & IRQF_ONESHOT) {
1006                 /*
1007                  * Unlikely to have 32 resp 64 irqs sharing one line,
1008                  * but who knows.
1009                  */
1010                 if (thread_mask == ~0UL) {
1011                         ret = -EBUSY;
1012                         goto out_mask;
1013                 }
1014                 /*
1015                  * The thread_mask for the action is or'ed to
1016                  * desc->thread_active to indicate that the
1017                  * IRQF_ONESHOT thread handler has been woken, but not
1018                  * yet finished. The bit is cleared when a thread
1019                  * completes. When all threads of a shared interrupt
1020                  * line have completed desc->threads_active becomes
1021                  * zero and the interrupt line is unmasked. See
1022                  * handle.c:irq_wake_thread() for further information.
1023                  *
1024                  * If no thread is woken by primary (hard irq context)
1025                  * interrupt handlers, then desc->threads_active is
1026                  * also checked for zero to unmask the irq line in the
1027                  * affected hard irq flow handlers
1028                  * (handle_[fasteoi|level]_irq).
1029                  *
1030                  * The new action gets the first zero bit of
1031                  * thread_mask assigned. See the loop above which or's
1032                  * all existing action->thread_mask bits.
1033                  */
1034                 new->thread_mask = 1 << ffz(thread_mask);
1035         }
1036
1037         if (!shared) {
1038                 init_waitqueue_head(&desc->wait_for_threads);
1039
1040                 /* Setup the type (level, edge polarity) if configured: */
1041                 if (new->flags & IRQF_TRIGGER_MASK) {
1042                         ret = __irq_set_trigger(desc, irq,
1043                                         new->flags & IRQF_TRIGGER_MASK);
1044
1045                         if (ret)
1046                                 goto out_mask;
1047                 }
1048
1049                 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1050                                   IRQS_ONESHOT | IRQS_WAITING);
1051                 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1052
1053                 if (new->flags & IRQF_PERCPU) {
1054                         irqd_set(&desc->irq_data, IRQD_PER_CPU);
1055                         irq_settings_set_per_cpu(desc);
1056                 }
1057
1058                 if (new->flags & IRQF_ONESHOT)
1059                         desc->istate |= IRQS_ONESHOT;
1060
1061                 if (irq_settings_can_autoenable(desc))
1062                         irq_startup(desc, true);
1063                 else
1064                         /* Undo nested disables: */
1065                         desc->depth = 1;
1066
1067                 /* Exclude IRQ from balancing if requested */
1068                 if (new->flags & IRQF_NOBALANCING) {
1069                         irq_settings_set_no_balancing(desc);
1070                         irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1071                 }
1072
1073                 /* Set default affinity mask once everything is setup */
1074                 setup_affinity(irq, desc, mask);
1075
1076         } else if (new->flags & IRQF_TRIGGER_MASK) {
1077                 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1078                 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1079
1080                 if (nmsk != omsk)
1081                         /* hope the handler works with current  trigger mode */
1082                         pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
1083                                    irq, nmsk, omsk);
1084         }
1085
1086         new->irq = irq;
1087         *old_ptr = new;
1088
1089         /* Reset broken irq detection when installing new handler */
1090         desc->irq_count = 0;
1091         desc->irqs_unhandled = 0;
1092
1093         /*
1094          * Check whether we disabled the irq via the spurious handler
1095          * before. Reenable it and give it another chance.
1096          */
1097         if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1098                 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1099                 __enable_irq(desc, irq, false);
1100         }
1101
1102         raw_spin_unlock_irqrestore(&desc->lock, flags);
1103
1104         /*
1105          * Strictly no need to wake it up, but hung_task complains
1106          * when no hard interrupt wakes the thread up.
1107          */
1108         if (new->thread)
1109                 wake_up_process(new->thread);
1110
1111         register_irq_proc(irq, desc);
1112         new->dir = NULL;
1113         register_handler_proc(irq, new);
1114         free_cpumask_var(mask);
1115
1116         return 0;
1117
1118 mismatch:
1119 #ifdef CONFIG_DEBUG_SHIRQ
1120         if (!(new->flags & IRQF_PROBE_SHARED)) {
1121                 printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
1122                 if (old_name)
1123                         printk(KERN_ERR "current handler: %s\n", old_name);
1124                 dump_stack();
1125         }
1126 #endif
1127         ret = -EBUSY;
1128
1129 out_mask:
1130         raw_spin_unlock_irqrestore(&desc->lock, flags);
1131         free_cpumask_var(mask);
1132
1133 out_thread:
1134         if (new->thread) {
1135                 struct task_struct *t = new->thread;
1136
1137                 new->thread = NULL;
1138                 if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
1139                         kthread_stop(t);
1140                 put_task_struct(t);
1141         }
1142 out_mput:
1143         module_put(desc->owner);
1144         return ret;
1145 }
1146
1147 /**
1148  *      setup_irq - setup an interrupt
1149  *      @irq: Interrupt line to setup
1150  *      @act: irqaction for the interrupt
1151  *
1152  * Used to statically setup interrupts in the early boot process.
1153  */
1154 int setup_irq(unsigned int irq, struct irqaction *act)
1155 {
1156         int retval;
1157         struct irq_desc *desc = irq_to_desc(irq);
1158
1159         if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1160                 return -EINVAL;
1161         chip_bus_lock(desc);
1162         retval = __setup_irq(irq, desc, act);
1163         chip_bus_sync_unlock(desc);
1164
1165         return retval;
1166 }
1167 EXPORT_SYMBOL_GPL(setup_irq);
1168
1169 /*
1170  * Internal function to unregister an irqaction - used to free
1171  * regular and special interrupts that are part of the architecture.
1172  */
1173 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1174 {
1175         struct irq_desc *desc = irq_to_desc(irq);
1176         struct irqaction *action, **action_ptr;
1177         unsigned long flags;
1178
1179         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1180
1181         if (!desc)
1182                 return NULL;
1183
1184         raw_spin_lock_irqsave(&desc->lock, flags);
1185
1186         /*
1187          * There can be multiple actions per IRQ descriptor, find the right
1188          * one based on the dev_id:
1189          */
1190         action_ptr = &desc->action;
1191         for (;;) {
1192                 action = *action_ptr;
1193
1194                 if (!action) {
1195                         WARN(1, "Trying to free already-free IRQ %d\n", irq);
1196                         raw_spin_unlock_irqrestore(&desc->lock, flags);
1197
1198                         return NULL;
1199                 }
1200
1201                 if (action->dev_id == dev_id)
1202                         break;
1203                 action_ptr = &action->next;
1204         }
1205
1206         /* Found it - now remove it from the list of entries: */
1207         *action_ptr = action->next;
1208
1209         /* Currently used only by UML, might disappear one day: */
1210 #ifdef CONFIG_IRQ_RELEASE_METHOD
1211         if (desc->irq_data.chip->release)
1212                 desc->irq_data.chip->release(irq, dev_id);
1213 #endif
1214
1215         /* If this was the last handler, shut down the IRQ line: */
1216         if (!desc->action)
1217                 irq_shutdown(desc);
1218
1219 #ifdef CONFIG_SMP
1220         /* make sure affinity_hint is cleaned up */
1221         if (WARN_ON_ONCE(desc->affinity_hint))
1222                 desc->affinity_hint = NULL;
1223 #endif
1224
1225         raw_spin_unlock_irqrestore(&desc->lock, flags);
1226
1227         unregister_handler_proc(irq, action);
1228
1229         /* Make sure it's not being used on another CPU: */
1230         synchronize_irq(irq);
1231
1232 #ifdef CONFIG_DEBUG_SHIRQ
1233         /*
1234          * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1235          * event to happen even now it's being freed, so let's make sure that
1236          * is so by doing an extra call to the handler ....
1237          *
1238          * ( We do this after actually deregistering it, to make sure that a
1239          *   'real' IRQ doesn't run in * parallel with our fake. )
1240          */
1241         if (action->flags & IRQF_SHARED) {
1242                 local_irq_save(flags);
1243                 action->handler(irq, dev_id);
1244                 local_irq_restore(flags);
1245         }
1246 #endif
1247
1248         if (action->thread) {
1249                 if (!test_bit(IRQTF_DIED, &action->thread_flags))
1250                         kthread_stop(action->thread);
1251                 put_task_struct(action->thread);
1252         }
1253
1254         module_put(desc->owner);
1255         return action;
1256 }
1257
1258 /**
1259  *      remove_irq - free an interrupt
1260  *      @irq: Interrupt line to free
1261  *      @act: irqaction for the interrupt
1262  *
1263  * Used to remove interrupts statically setup by the early boot process.
1264  */
1265 void remove_irq(unsigned int irq, struct irqaction *act)
1266 {
1267         struct irq_desc *desc = irq_to_desc(irq);
1268
1269         if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1270             __free_irq(irq, act->dev_id);
1271 }
1272 EXPORT_SYMBOL_GPL(remove_irq);
1273
1274 /**
1275  *      free_irq - free an interrupt allocated with request_irq
1276  *      @irq: Interrupt line to free
1277  *      @dev_id: Device identity to free
1278  *
1279  *      Remove an interrupt handler. The handler is removed and if the
1280  *      interrupt line is no longer in use by any driver it is disabled.
1281  *      On a shared IRQ the caller must ensure the interrupt is disabled
1282  *      on the card it drives before calling this function. The function
1283  *      does not return until any executing interrupts for this IRQ
1284  *      have completed.
1285  *
1286  *      This function must not be called from interrupt context.
1287  */
1288 void free_irq(unsigned int irq, void *dev_id)
1289 {
1290         struct irq_desc *desc = irq_to_desc(irq);
1291
1292         if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1293                 return;
1294
1295 #ifdef CONFIG_SMP
1296         if (WARN_ON(desc->affinity_notify))
1297                 desc->affinity_notify = NULL;
1298 #endif
1299
1300         chip_bus_lock(desc);
1301         kfree(__free_irq(irq, dev_id));
1302         chip_bus_sync_unlock(desc);
1303 }
1304 EXPORT_SYMBOL(free_irq);
1305
1306 /**
1307  *      request_threaded_irq - allocate an interrupt line
1308  *      @irq: Interrupt line to allocate
1309  *      @handler: Function to be called when the IRQ occurs.
1310  *                Primary handler for threaded interrupts
1311  *                If NULL and thread_fn != NULL the default
1312  *                primary handler is installed
1313  *      @thread_fn: Function called from the irq handler thread
1314  *                  If NULL, no irq thread is created
1315  *      @irqflags: Interrupt type flags
1316  *      @devname: An ascii name for the claiming device
1317  *      @dev_id: A cookie passed back to the handler function
1318  *
1319  *      This call allocates interrupt resources and enables the
1320  *      interrupt line and IRQ handling. From the point this
1321  *      call is made your handler function may be invoked. Since
1322  *      your handler function must clear any interrupt the board
1323  *      raises, you must take care both to initialise your hardware
1324  *      and to set up the interrupt handler in the right order.
1325  *
1326  *      If you want to set up a threaded irq handler for your device
1327  *      then you need to supply @handler and @thread_fn. @handler is
1328  *      still called in hard interrupt context and has to check
1329  *      whether the interrupt originates from the device. If yes it
1330  *      needs to disable the interrupt on the device and return
1331  *      IRQ_WAKE_THREAD which will wake up the handler thread and run
1332  *      @thread_fn. This split handler design is necessary to support
1333  *      shared interrupts.
1334  *
1335  *      Dev_id must be globally unique. Normally the address of the
1336  *      device data structure is used as the cookie. Since the handler
1337  *      receives this value it makes sense to use it.
1338  *
1339  *      If your interrupt is shared you must pass a non NULL dev_id
1340  *      as this is required when freeing the interrupt.
1341  *
1342  *      Flags:
1343  *
1344  *      IRQF_SHARED             Interrupt is shared
1345  *      IRQF_SAMPLE_RANDOM      The interrupt can be used for entropy
1346  *      IRQF_TRIGGER_*          Specify active edge(s) or level
1347  *
1348  */
1349 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1350                          irq_handler_t thread_fn, unsigned long irqflags,
1351                          const char *devname, void *dev_id)
1352 {
1353         struct irqaction *action;
1354         struct irq_desc *desc;
1355         int retval;
1356
1357         /*
1358          * Sanity-check: shared interrupts must pass in a real dev-ID,
1359          * otherwise we'll have trouble later trying to figure out
1360          * which interrupt is which (messes up the interrupt freeing
1361          * logic etc).
1362          */
1363         if ((irqflags & IRQF_SHARED) && !dev_id)
1364                 return -EINVAL;
1365
1366         desc = irq_to_desc(irq);
1367         if (!desc)
1368                 return -EINVAL;
1369
1370         if (!irq_settings_can_request(desc) ||
1371             WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1372                 return -EINVAL;
1373
1374         if (!handler) {
1375                 if (!thread_fn)
1376                         return -EINVAL;
1377                 handler = irq_default_primary_handler;
1378         }
1379
1380         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1381         if (!action)
1382                 return -ENOMEM;
1383
1384         action->handler = handler;
1385         action->thread_fn = thread_fn;
1386         action->flags = irqflags;
1387         action->name = devname;
1388         action->dev_id = dev_id;
1389
1390         chip_bus_lock(desc);
1391         retval = __setup_irq(irq, desc, action);
1392         chip_bus_sync_unlock(desc);
1393
1394         if (retval)
1395                 kfree(action);
1396
1397 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1398         if (!retval && (irqflags & IRQF_SHARED)) {
1399                 /*
1400                  * It's a shared IRQ -- the driver ought to be prepared for it
1401                  * to happen immediately, so let's make sure....
1402                  * We disable the irq to make sure that a 'real' IRQ doesn't
1403                  * run in parallel with our fake.
1404                  */
1405                 unsigned long flags;
1406
1407                 disable_irq(irq);
1408                 local_irq_save(flags);
1409
1410                 handler(irq, dev_id);
1411
1412                 local_irq_restore(flags);
1413                 enable_irq(irq);
1414         }
1415 #endif
1416         return retval;
1417 }
1418 EXPORT_SYMBOL(request_threaded_irq);
1419
1420 /**
1421  *      request_any_context_irq - allocate an interrupt line
1422  *      @irq: Interrupt line to allocate
1423  *      @handler: Function to be called when the IRQ occurs.
1424  *                Threaded handler for threaded interrupts.
1425  *      @flags: Interrupt type flags
1426  *      @name: An ascii name for the claiming device
1427  *      @dev_id: A cookie passed back to the handler function
1428  *
1429  *      This call allocates interrupt resources and enables the
1430  *      interrupt line and IRQ handling. It selects either a
1431  *      hardirq or threaded handling method depending on the
1432  *      context.
1433  *
1434  *      On failure, it returns a negative value. On success,
1435  *      it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1436  */
1437 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1438                             unsigned long flags, const char *name, void *dev_id)
1439 {
1440         struct irq_desc *desc = irq_to_desc(irq);
1441         int ret;
1442
1443         if (!desc)
1444                 return -EINVAL;
1445
1446         if (irq_settings_is_nested_thread(desc)) {
1447                 ret = request_threaded_irq(irq, NULL, handler,
1448                                            flags, name, dev_id);
1449                 return !ret ? IRQC_IS_NESTED : ret;
1450         }
1451
1452         ret = request_irq(irq, handler, flags, name, dev_id);
1453         return !ret ? IRQC_IS_HARDIRQ : ret;
1454 }
1455 EXPORT_SYMBOL_GPL(request_any_context_irq);
1456
1457 void enable_percpu_irq(unsigned int irq, unsigned int type)
1458 {
1459         unsigned int cpu = smp_processor_id();
1460         unsigned long flags;
1461         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1462
1463         if (!desc)
1464                 return;
1465
1466         type &= IRQ_TYPE_SENSE_MASK;
1467         if (type != IRQ_TYPE_NONE) {
1468                 int ret;
1469
1470                 ret = __irq_set_trigger(desc, irq, type);
1471
1472                 if (ret) {
1473                         WARN(1, "failed to set type for IRQ%d\n", irq);
1474                         goto out;
1475                 }
1476         }
1477
1478         irq_percpu_enable(desc, cpu);
1479 out:
1480         irq_put_desc_unlock(desc, flags);
1481 }
1482
1483 void disable_percpu_irq(unsigned int irq)
1484 {
1485         unsigned int cpu = smp_processor_id();
1486         unsigned long flags;
1487         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1488
1489         if (!desc)
1490                 return;
1491
1492         irq_percpu_disable(desc, cpu);
1493         irq_put_desc_unlock(desc, flags);
1494 }
1495
1496 /*
1497  * Internal function to unregister a percpu irqaction.
1498  */
1499 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1500 {
1501         struct irq_desc *desc = irq_to_desc(irq);
1502         struct irqaction *action;
1503         unsigned long flags;
1504
1505         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1506
1507         if (!desc)
1508                 return NULL;
1509
1510         raw_spin_lock_irqsave(&desc->lock, flags);
1511
1512         action = desc->action;
1513         if (!action || action->percpu_dev_id != dev_id) {
1514                 WARN(1, "Trying to free already-free IRQ %d\n", irq);
1515                 goto bad;
1516         }
1517
1518         if (!cpumask_empty(desc->percpu_enabled)) {
1519                 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1520                      irq, cpumask_first(desc->percpu_enabled));
1521                 goto bad;
1522         }
1523
1524         /* Found it - now remove it from the list of entries: */
1525         desc->action = NULL;
1526
1527         raw_spin_unlock_irqrestore(&desc->lock, flags);
1528
1529         unregister_handler_proc(irq, action);
1530
1531         module_put(desc->owner);
1532         return action;
1533
1534 bad:
1535         raw_spin_unlock_irqrestore(&desc->lock, flags);
1536         return NULL;
1537 }
1538
1539 /**
1540  *      remove_percpu_irq - free a per-cpu interrupt
1541  *      @irq: Interrupt line to free
1542  *      @act: irqaction for the interrupt
1543  *
1544  * Used to remove interrupts statically setup by the early boot process.
1545  */
1546 void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1547 {
1548         struct irq_desc *desc = irq_to_desc(irq);
1549
1550         if (desc && irq_settings_is_per_cpu_devid(desc))
1551             __free_percpu_irq(irq, act->percpu_dev_id);
1552 }
1553
1554 /**
1555  *      free_percpu_irq - free an interrupt allocated with request_percpu_irq
1556  *      @irq: Interrupt line to free
1557  *      @dev_id: Device identity to free
1558  *
1559  *      Remove a percpu interrupt handler. The handler is removed, but
1560  *      the interrupt line is not disabled. This must be done on each
1561  *      CPU before calling this function. The function does not return
1562  *      until any executing interrupts for this IRQ have completed.
1563  *
1564  *      This function must not be called from interrupt context.
1565  */
1566 void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1567 {
1568         struct irq_desc *desc = irq_to_desc(irq);
1569
1570         if (!desc || !irq_settings_is_per_cpu_devid(desc))
1571                 return;
1572
1573         chip_bus_lock(desc);
1574         kfree(__free_percpu_irq(irq, dev_id));
1575         chip_bus_sync_unlock(desc);
1576 }
1577
1578 /**
1579  *      setup_percpu_irq - setup a per-cpu interrupt
1580  *      @irq: Interrupt line to setup
1581  *      @act: irqaction for the interrupt
1582  *
1583  * Used to statically setup per-cpu interrupts in the early boot process.
1584  */
1585 int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1586 {
1587         struct irq_desc *desc = irq_to_desc(irq);
1588         int retval;
1589
1590         if (!desc || !irq_settings_is_per_cpu_devid(desc))
1591                 return -EINVAL;
1592         chip_bus_lock(desc);
1593         retval = __setup_irq(irq, desc, act);
1594         chip_bus_sync_unlock(desc);
1595
1596         return retval;
1597 }
1598
1599 /**
1600  *      request_percpu_irq - allocate a percpu interrupt line
1601  *      @irq: Interrupt line to allocate
1602  *      @handler: Function to be called when the IRQ occurs.
1603  *      @devname: An ascii name for the claiming device
1604  *      @dev_id: A percpu cookie passed back to the handler function
1605  *
1606  *      This call allocates interrupt resources, but doesn't
1607  *      automatically enable the interrupt. It has to be done on each
1608  *      CPU using enable_percpu_irq().
1609  *
1610  *      Dev_id must be globally unique. It is a per-cpu variable, and
1611  *      the handler gets called with the interrupted CPU's instance of
1612  *      that variable.
1613  */
1614 int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1615                        const char *devname, void __percpu *dev_id)
1616 {
1617         struct irqaction *action;
1618         struct irq_desc *desc;
1619         int retval;
1620
1621         if (!dev_id)
1622                 return -EINVAL;
1623
1624         desc = irq_to_desc(irq);
1625         if (!desc || !irq_settings_can_request(desc) ||
1626             !irq_settings_is_per_cpu_devid(desc))
1627                 return -EINVAL;
1628
1629         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1630         if (!action)
1631                 return -ENOMEM;
1632
1633         action->handler = handler;
1634         action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1635         action->name = devname;
1636         action->percpu_dev_id = dev_id;
1637
1638         chip_bus_lock(desc);
1639         retval = __setup_irq(irq, desc, action);
1640         chip_bus_sync_unlock(desc);
1641
1642         if (retval)
1643                 kfree(action);
1644
1645         return retval;
1646 }