genirq: Provide compat handling for chip->set_affinity()
[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 /**
21  *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
22  *      @irq: interrupt number to wait for
23  *
24  *      This function waits for any pending IRQ handlers for this interrupt
25  *      to complete before returning. If you use this function while
26  *      holding a resource the IRQ handler may need you will deadlock.
27  *
28  *      This function may be called - with care - from IRQ context.
29  */
30 void synchronize_irq(unsigned int irq)
31 {
32         struct irq_desc *desc = irq_to_desc(irq);
33         unsigned int status;
34
35         if (!desc)
36                 return;
37
38         do {
39                 unsigned long flags;
40
41                 /*
42                  * Wait until we're out of the critical section.  This might
43                  * give the wrong answer due to the lack of memory barriers.
44                  */
45                 while (desc->status & IRQ_INPROGRESS)
46                         cpu_relax();
47
48                 /* Ok, that indicated we're done: double-check carefully. */
49                 raw_spin_lock_irqsave(&desc->lock, flags);
50                 status = desc->status;
51                 raw_spin_unlock_irqrestore(&desc->lock, flags);
52
53                 /* Oops, that failed? */
54         } while (status & IRQ_INPROGRESS);
55
56         /*
57          * We made sure that no hardirq handler is running. Now verify
58          * that no threaded handlers are active.
59          */
60         wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
61 }
62 EXPORT_SYMBOL(synchronize_irq);
63
64 #ifdef CONFIG_SMP
65 cpumask_var_t irq_default_affinity;
66
67 /**
68  *      irq_can_set_affinity - Check if the affinity of a given irq can be set
69  *      @irq:           Interrupt to check
70  *
71  */
72 int irq_can_set_affinity(unsigned int irq)
73 {
74         struct irq_desc *desc = irq_to_desc(irq);
75
76         if (CHECK_IRQ_PER_CPU(desc->status) || !desc->irq_data.chip ||
77             !desc->irq_data.chip->irq_set_affinity)
78                 return 0;
79
80         return 1;
81 }
82
83 /**
84  *      irq_set_thread_affinity - Notify irq threads to adjust affinity
85  *      @desc:          irq descriptor which has affitnity changed
86  *
87  *      We just set IRQTF_AFFINITY and delegate the affinity setting
88  *      to the interrupt thread itself. We can not call
89  *      set_cpus_allowed_ptr() here as we hold desc->lock and this
90  *      code can be called from hard interrupt context.
91  */
92 void irq_set_thread_affinity(struct irq_desc *desc)
93 {
94         struct irqaction *action = desc->action;
95
96         while (action) {
97                 if (action->thread)
98                         set_bit(IRQTF_AFFINITY, &action->thread_flags);
99                 action = action->next;
100         }
101 }
102
103 /**
104  *      irq_set_affinity - Set the irq affinity of a given irq
105  *      @irq:           Interrupt to set affinity
106  *      @cpumask:       cpumask
107  *
108  */
109 int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
110 {
111         struct irq_desc *desc = irq_to_desc(irq);
112         struct irq_chip *chip = desc->irq_data.chip;
113         unsigned long flags;
114
115         if (!chip->irq_set_affinity)
116                 return -EINVAL;
117
118         raw_spin_lock_irqsave(&desc->lock, flags);
119
120 #ifdef CONFIG_GENERIC_PENDING_IRQ
121         if (desc->status & IRQ_MOVE_PCNTXT) {
122                 if (!chip->irq_set_affinity(&desc->irq_data, cpumask, false)) {
123                         cpumask_copy(desc->irq_data.affinity, cpumask);
124                         irq_set_thread_affinity(desc);
125                 }
126         }
127         else {
128                 desc->status |= IRQ_MOVE_PENDING;
129                 cpumask_copy(desc->pending_mask, cpumask);
130         }
131 #else
132         if (!chip->irq_set_affinity(&desc->irq_data, cpumask, false)) {
133                 cpumask_copy(desc->irq_data.affinity, cpumask);
134                 irq_set_thread_affinity(desc);
135         }
136 #endif
137         desc->status |= IRQ_AFFINITY_SET;
138         raw_spin_unlock_irqrestore(&desc->lock, flags);
139         return 0;
140 }
141
142 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
143 {
144         struct irq_desc *desc = irq_to_desc(irq);
145         unsigned long flags;
146
147         if (!desc)
148                 return -EINVAL;
149
150         raw_spin_lock_irqsave(&desc->lock, flags);
151         desc->affinity_hint = m;
152         raw_spin_unlock_irqrestore(&desc->lock, flags);
153
154         return 0;
155 }
156 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
157
158 #ifndef CONFIG_AUTO_IRQ_AFFINITY
159 /*
160  * Generic version of the affinity autoselector.
161  */
162 static int setup_affinity(unsigned int irq, struct irq_desc *desc)
163 {
164         if (!irq_can_set_affinity(irq))
165                 return 0;
166
167         /*
168          * Preserve an userspace affinity setup, but make sure that
169          * one of the targets is online.
170          */
171         if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
172                 if (cpumask_any_and(desc->irq_data.affinity, cpu_online_mask)
173                     < nr_cpu_ids)
174                         goto set_affinity;
175                 else
176                         desc->status &= ~IRQ_AFFINITY_SET;
177         }
178
179         cpumask_and(desc->irq_data.affinity, cpu_online_mask, irq_default_affinity);
180 set_affinity:
181         desc->irq_data.chip->irq_set_affinity(&desc->irq_data, desc->irq_data.affinity, false);
182
183         return 0;
184 }
185 #else
186 static inline int setup_affinity(unsigned int irq, struct irq_desc *d)
187 {
188         return irq_select_affinity(irq);
189 }
190 #endif
191
192 /*
193  * Called when affinity is set via /proc/irq
194  */
195 int irq_select_affinity_usr(unsigned int irq)
196 {
197         struct irq_desc *desc = irq_to_desc(irq);
198         unsigned long flags;
199         int ret;
200
201         raw_spin_lock_irqsave(&desc->lock, flags);
202         ret = setup_affinity(irq, desc);
203         if (!ret)
204                 irq_set_thread_affinity(desc);
205         raw_spin_unlock_irqrestore(&desc->lock, flags);
206
207         return ret;
208 }
209
210 #else
211 static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
212 {
213         return 0;
214 }
215 #endif
216
217 void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
218 {
219         if (suspend) {
220                 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
221                         return;
222                 desc->status |= IRQ_SUSPENDED;
223         }
224
225         if (!desc->depth++) {
226                 desc->status |= IRQ_DISABLED;
227                 desc->irq_data.chip->irq_disable(&desc->irq_data);
228         }
229 }
230
231 /**
232  *      disable_irq_nosync - disable an irq without waiting
233  *      @irq: Interrupt to disable
234  *
235  *      Disable the selected interrupt line.  Disables and Enables are
236  *      nested.
237  *      Unlike disable_irq(), this function does not ensure existing
238  *      instances of the IRQ handler have completed before returning.
239  *
240  *      This function may be called from IRQ context.
241  */
242 void disable_irq_nosync(unsigned int irq)
243 {
244         struct irq_desc *desc = irq_to_desc(irq);
245         unsigned long flags;
246
247         if (!desc)
248                 return;
249
250         chip_bus_lock(desc);
251         raw_spin_lock_irqsave(&desc->lock, flags);
252         __disable_irq(desc, irq, false);
253         raw_spin_unlock_irqrestore(&desc->lock, flags);
254         chip_bus_sync_unlock(desc);
255 }
256 EXPORT_SYMBOL(disable_irq_nosync);
257
258 /**
259  *      disable_irq - disable an irq and wait for completion
260  *      @irq: Interrupt to disable
261  *
262  *      Disable the selected interrupt line.  Enables and Disables are
263  *      nested.
264  *      This function waits for any pending IRQ handlers for this interrupt
265  *      to complete before returning. If you use this function while
266  *      holding a resource the IRQ handler may need you will deadlock.
267  *
268  *      This function may be called - with care - from IRQ context.
269  */
270 void disable_irq(unsigned int irq)
271 {
272         struct irq_desc *desc = irq_to_desc(irq);
273
274         if (!desc)
275                 return;
276
277         disable_irq_nosync(irq);
278         if (desc->action)
279                 synchronize_irq(irq);
280 }
281 EXPORT_SYMBOL(disable_irq);
282
283 void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
284 {
285         if (resume)
286                 desc->status &= ~IRQ_SUSPENDED;
287
288         switch (desc->depth) {
289         case 0:
290  err_out:
291                 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
292                 break;
293         case 1: {
294                 unsigned int status = desc->status & ~IRQ_DISABLED;
295
296                 if (desc->status & IRQ_SUSPENDED)
297                         goto err_out;
298                 /* Prevent probing on this irq: */
299                 desc->status = status | IRQ_NOPROBE;
300                 check_irq_resend(desc, irq);
301                 /* fall-through */
302         }
303         default:
304                 desc->depth--;
305         }
306 }
307
308 /**
309  *      enable_irq - enable handling of an irq
310  *      @irq: Interrupt to enable
311  *
312  *      Undoes the effect of one call to disable_irq().  If this
313  *      matches the last disable, processing of interrupts on this
314  *      IRQ line is re-enabled.
315  *
316  *      This function may be called from IRQ context only when
317  *      desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
318  */
319 void enable_irq(unsigned int irq)
320 {
321         struct irq_desc *desc = irq_to_desc(irq);
322         unsigned long flags;
323
324         if (!desc)
325                 return;
326
327         chip_bus_lock(desc);
328         raw_spin_lock_irqsave(&desc->lock, flags);
329         __enable_irq(desc, irq, false);
330         raw_spin_unlock_irqrestore(&desc->lock, flags);
331         chip_bus_sync_unlock(desc);
332 }
333 EXPORT_SYMBOL(enable_irq);
334
335 static int set_irq_wake_real(unsigned int irq, unsigned int on)
336 {
337         struct irq_desc *desc = irq_to_desc(irq);
338         int ret = -ENXIO;
339
340         if (desc->irq_data.chip->set_wake)
341                 ret = desc->irq_data.chip->set_wake(irq, on);
342
343         return ret;
344 }
345
346 /**
347  *      set_irq_wake - control irq power management wakeup
348  *      @irq:   interrupt to control
349  *      @on:    enable/disable power management wakeup
350  *
351  *      Enable/disable power management wakeup mode, which is
352  *      disabled by default.  Enables and disables must match,
353  *      just as they match for non-wakeup mode support.
354  *
355  *      Wakeup mode lets this IRQ wake the system from sleep
356  *      states like "suspend to RAM".
357  */
358 int set_irq_wake(unsigned int irq, unsigned int on)
359 {
360         struct irq_desc *desc = irq_to_desc(irq);
361         unsigned long flags;
362         int ret = 0;
363
364         /* wakeup-capable irqs can be shared between drivers that
365          * don't need to have the same sleep mode behaviors.
366          */
367         raw_spin_lock_irqsave(&desc->lock, flags);
368         if (on) {
369                 if (desc->wake_depth++ == 0) {
370                         ret = set_irq_wake_real(irq, on);
371                         if (ret)
372                                 desc->wake_depth = 0;
373                         else
374                                 desc->status |= IRQ_WAKEUP;
375                 }
376         } else {
377                 if (desc->wake_depth == 0) {
378                         WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
379                 } else if (--desc->wake_depth == 0) {
380                         ret = set_irq_wake_real(irq, on);
381                         if (ret)
382                                 desc->wake_depth = 1;
383                         else
384                                 desc->status &= ~IRQ_WAKEUP;
385                 }
386         }
387
388         raw_spin_unlock_irqrestore(&desc->lock, flags);
389         return ret;
390 }
391 EXPORT_SYMBOL(set_irq_wake);
392
393 /*
394  * Internal function that tells the architecture code whether a
395  * particular irq has been exclusively allocated or is available
396  * for driver use.
397  */
398 int can_request_irq(unsigned int irq, unsigned long irqflags)
399 {
400         struct irq_desc *desc = irq_to_desc(irq);
401         struct irqaction *action;
402         unsigned long flags;
403
404         if (!desc)
405                 return 0;
406
407         if (desc->status & IRQ_NOREQUEST)
408                 return 0;
409
410         raw_spin_lock_irqsave(&desc->lock, flags);
411         action = desc->action;
412         if (action)
413                 if (irqflags & action->flags & IRQF_SHARED)
414                         action = NULL;
415
416         raw_spin_unlock_irqrestore(&desc->lock, flags);
417
418         return !action;
419 }
420
421 void compat_irq_chip_set_default_handler(struct irq_desc *desc)
422 {
423         /*
424          * If the architecture still has not overriden
425          * the flow handler then zap the default. This
426          * should catch incorrect flow-type setting.
427          */
428         if (desc->handle_irq == &handle_bad_irq)
429                 desc->handle_irq = NULL;
430 }
431
432 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
433                 unsigned long flags)
434 {
435         int ret;
436         struct irq_chip *chip = desc->irq_data.chip;
437
438         if (!chip || !chip->set_type) {
439                 /*
440                  * IRQF_TRIGGER_* but the PIC does not support multiple
441                  * flow-types?
442                  */
443                 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
444                                 chip ? (chip->name ? : "unknown") : "unknown");
445                 return 0;
446         }
447
448         /* caller masked out all except trigger mode flags */
449         ret = chip->set_type(irq, flags);
450
451         if (ret)
452                 pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
453                                 (int)flags, irq, chip->set_type);
454         else {
455                 if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
456                         flags |= IRQ_LEVEL;
457                 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
458                 desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK);
459                 desc->status |= flags;
460
461                 if (chip != desc->irq_data.chip)
462                         irq_chip_set_defaults(desc->irq_data.chip);
463         }
464
465         return ret;
466 }
467
468 /*
469  * Default primary interrupt handler for threaded interrupts. Is
470  * assigned as primary handler when request_threaded_irq is called
471  * with handler == NULL. Useful for oneshot interrupts.
472  */
473 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
474 {
475         return IRQ_WAKE_THREAD;
476 }
477
478 /*
479  * Primary handler for nested threaded interrupts. Should never be
480  * called.
481  */
482 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
483 {
484         WARN(1, "Primary handler called for nested irq %d\n", irq);
485         return IRQ_NONE;
486 }
487
488 static int irq_wait_for_interrupt(struct irqaction *action)
489 {
490         while (!kthread_should_stop()) {
491                 set_current_state(TASK_INTERRUPTIBLE);
492
493                 if (test_and_clear_bit(IRQTF_RUNTHREAD,
494                                        &action->thread_flags)) {
495                         __set_current_state(TASK_RUNNING);
496                         return 0;
497                 }
498                 schedule();
499         }
500         return -1;
501 }
502
503 /*
504  * Oneshot interrupts keep the irq line masked until the threaded
505  * handler finished. unmask if the interrupt has not been disabled and
506  * is marked MASKED.
507  */
508 static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc)
509 {
510 again:
511         chip_bus_lock(desc);
512         raw_spin_lock_irq(&desc->lock);
513
514         /*
515          * Implausible though it may be we need to protect us against
516          * the following scenario:
517          *
518          * The thread is faster done than the hard interrupt handler
519          * on the other CPU. If we unmask the irq line then the
520          * interrupt can come in again and masks the line, leaves due
521          * to IRQ_INPROGRESS and the irq line is masked forever.
522          */
523         if (unlikely(desc->status & IRQ_INPROGRESS)) {
524                 raw_spin_unlock_irq(&desc->lock);
525                 chip_bus_sync_unlock(desc);
526                 cpu_relax();
527                 goto again;
528         }
529
530         if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) {
531                 desc->status &= ~IRQ_MASKED;
532                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
533         }
534         raw_spin_unlock_irq(&desc->lock);
535         chip_bus_sync_unlock(desc);
536 }
537
538 #ifdef CONFIG_SMP
539 /*
540  * Check whether we need to change the affinity of the interrupt thread.
541  */
542 static void
543 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
544 {
545         cpumask_var_t mask;
546
547         if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
548                 return;
549
550         /*
551          * In case we are out of memory we set IRQTF_AFFINITY again and
552          * try again next time
553          */
554         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
555                 set_bit(IRQTF_AFFINITY, &action->thread_flags);
556                 return;
557         }
558
559         raw_spin_lock_irq(&desc->lock);
560         cpumask_copy(mask, desc->irq_data.affinity);
561         raw_spin_unlock_irq(&desc->lock);
562
563         set_cpus_allowed_ptr(current, mask);
564         free_cpumask_var(mask);
565 }
566 #else
567 static inline void
568 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
569 #endif
570
571 /*
572  * Interrupt handler thread
573  */
574 static int irq_thread(void *data)
575 {
576         struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
577         struct irqaction *action = data;
578         struct irq_desc *desc = irq_to_desc(action->irq);
579         int wake, oneshot = desc->status & IRQ_ONESHOT;
580
581         sched_setscheduler(current, SCHED_FIFO, &param);
582         current->irqaction = action;
583
584         while (!irq_wait_for_interrupt(action)) {
585
586                 irq_thread_check_affinity(desc, action);
587
588                 atomic_inc(&desc->threads_active);
589
590                 raw_spin_lock_irq(&desc->lock);
591                 if (unlikely(desc->status & IRQ_DISABLED)) {
592                         /*
593                          * CHECKME: We might need a dedicated
594                          * IRQ_THREAD_PENDING flag here, which
595                          * retriggers the thread in check_irq_resend()
596                          * but AFAICT IRQ_PENDING should be fine as it
597                          * retriggers the interrupt itself --- tglx
598                          */
599                         desc->status |= IRQ_PENDING;
600                         raw_spin_unlock_irq(&desc->lock);
601                 } else {
602                         raw_spin_unlock_irq(&desc->lock);
603
604                         action->thread_fn(action->irq, action->dev_id);
605
606                         if (oneshot)
607                                 irq_finalize_oneshot(action->irq, desc);
608                 }
609
610                 wake = atomic_dec_and_test(&desc->threads_active);
611
612                 if (wake && waitqueue_active(&desc->wait_for_threads))
613                         wake_up(&desc->wait_for_threads);
614         }
615
616         /*
617          * Clear irqaction. Otherwise exit_irq_thread() would make
618          * fuzz about an active irq thread going into nirvana.
619          */
620         current->irqaction = NULL;
621         return 0;
622 }
623
624 /*
625  * Called from do_exit()
626  */
627 void exit_irq_thread(void)
628 {
629         struct task_struct *tsk = current;
630
631         if (!tsk->irqaction)
632                 return;
633
634         printk(KERN_ERR
635                "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
636                tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
637
638         /*
639          * Set the THREAD DIED flag to prevent further wakeups of the
640          * soon to be gone threaded handler.
641          */
642         set_bit(IRQTF_DIED, &tsk->irqaction->flags);
643 }
644
645 /*
646  * Internal function to register an irqaction - typically used to
647  * allocate special interrupts that are part of the architecture.
648  */
649 static int
650 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
651 {
652         struct irqaction *old, **old_ptr;
653         const char *old_name = NULL;
654         unsigned long flags;
655         int nested, shared = 0;
656         int ret;
657
658         if (!desc)
659                 return -EINVAL;
660
661         if (desc->irq_data.chip == &no_irq_chip)
662                 return -ENOSYS;
663         /*
664          * Some drivers like serial.c use request_irq() heavily,
665          * so we have to be careful not to interfere with a
666          * running system.
667          */
668         if (new->flags & IRQF_SAMPLE_RANDOM) {
669                 /*
670                  * This function might sleep, we want to call it first,
671                  * outside of the atomic block.
672                  * Yes, this might clear the entropy pool if the wrong
673                  * driver is attempted to be loaded, without actually
674                  * installing a new handler, but is this really a problem,
675                  * only the sysadmin is able to do this.
676                  */
677                 rand_initialize_irq(irq);
678         }
679
680         /* Oneshot interrupts are not allowed with shared */
681         if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED))
682                 return -EINVAL;
683
684         /*
685          * Check whether the interrupt nests into another interrupt
686          * thread.
687          */
688         nested = desc->status & IRQ_NESTED_THREAD;
689         if (nested) {
690                 if (!new->thread_fn)
691                         return -EINVAL;
692                 /*
693                  * Replace the primary handler which was provided from
694                  * the driver for non nested interrupt handling by the
695                  * dummy function which warns when called.
696                  */
697                 new->handler = irq_nested_primary_handler;
698         }
699
700         /*
701          * Create a handler thread when a thread function is supplied
702          * and the interrupt does not nest into another interrupt
703          * thread.
704          */
705         if (new->thread_fn && !nested) {
706                 struct task_struct *t;
707
708                 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
709                                    new->name);
710                 if (IS_ERR(t))
711                         return PTR_ERR(t);
712                 /*
713                  * We keep the reference to the task struct even if
714                  * the thread dies to avoid that the interrupt code
715                  * references an already freed task_struct.
716                  */
717                 get_task_struct(t);
718                 new->thread = t;
719         }
720
721         /*
722          * The following block of code has to be executed atomically
723          */
724         raw_spin_lock_irqsave(&desc->lock, flags);
725         old_ptr = &desc->action;
726         old = *old_ptr;
727         if (old) {
728                 /*
729                  * Can't share interrupts unless both agree to and are
730                  * the same type (level, edge, polarity). So both flag
731                  * fields must have IRQF_SHARED set and the bits which
732                  * set the trigger type must match.
733                  */
734                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
735                     ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) {
736                         old_name = old->name;
737                         goto mismatch;
738                 }
739
740 #if defined(CONFIG_IRQ_PER_CPU)
741                 /* All handlers must agree on per-cpuness */
742                 if ((old->flags & IRQF_PERCPU) !=
743                     (new->flags & IRQF_PERCPU))
744                         goto mismatch;
745 #endif
746
747                 /* add new interrupt at end of irq queue */
748                 do {
749                         old_ptr = &old->next;
750                         old = *old_ptr;
751                 } while (old);
752                 shared = 1;
753         }
754
755         if (!shared) {
756                 irq_chip_set_defaults(desc->irq_data.chip);
757
758                 init_waitqueue_head(&desc->wait_for_threads);
759
760                 /* Setup the type (level, edge polarity) if configured: */
761                 if (new->flags & IRQF_TRIGGER_MASK) {
762                         ret = __irq_set_trigger(desc, irq,
763                                         new->flags & IRQF_TRIGGER_MASK);
764
765                         if (ret)
766                                 goto out_thread;
767                 } else
768                         compat_irq_chip_set_default_handler(desc);
769 #if defined(CONFIG_IRQ_PER_CPU)
770                 if (new->flags & IRQF_PERCPU)
771                         desc->status |= IRQ_PER_CPU;
772 #endif
773
774                 desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_ONESHOT |
775                                   IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
776
777                 if (new->flags & IRQF_ONESHOT)
778                         desc->status |= IRQ_ONESHOT;
779
780                 if (!(desc->status & IRQ_NOAUTOEN)) {
781                         desc->depth = 0;
782                         desc->status &= ~IRQ_DISABLED;
783                         desc->irq_data.chip->irq_startup(&desc->irq_data);
784                 } else
785                         /* Undo nested disables: */
786                         desc->depth = 1;
787
788                 /* Exclude IRQ from balancing if requested */
789                 if (new->flags & IRQF_NOBALANCING)
790                         desc->status |= IRQ_NO_BALANCING;
791
792                 /* Set default affinity mask once everything is setup */
793                 setup_affinity(irq, desc);
794
795         } else if ((new->flags & IRQF_TRIGGER_MASK)
796                         && (new->flags & IRQF_TRIGGER_MASK)
797                                 != (desc->status & IRQ_TYPE_SENSE_MASK)) {
798                 /* hope the handler works with the actual trigger mode... */
799                 pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
800                                 irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK),
801                                 (int)(new->flags & IRQF_TRIGGER_MASK));
802         }
803
804         new->irq = irq;
805         *old_ptr = new;
806
807         /* Reset broken irq detection when installing new handler */
808         desc->irq_count = 0;
809         desc->irqs_unhandled = 0;
810
811         /*
812          * Check whether we disabled the irq via the spurious handler
813          * before. Reenable it and give it another chance.
814          */
815         if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
816                 desc->status &= ~IRQ_SPURIOUS_DISABLED;
817                 __enable_irq(desc, irq, false);
818         }
819
820         raw_spin_unlock_irqrestore(&desc->lock, flags);
821
822         /*
823          * Strictly no need to wake it up, but hung_task complains
824          * when no hard interrupt wakes the thread up.
825          */
826         if (new->thread)
827                 wake_up_process(new->thread);
828
829         register_irq_proc(irq, desc);
830         new->dir = NULL;
831         register_handler_proc(irq, new);
832
833         return 0;
834
835 mismatch:
836 #ifdef CONFIG_DEBUG_SHIRQ
837         if (!(new->flags & IRQF_PROBE_SHARED)) {
838                 printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
839                 if (old_name)
840                         printk(KERN_ERR "current handler: %s\n", old_name);
841                 dump_stack();
842         }
843 #endif
844         ret = -EBUSY;
845
846 out_thread:
847         raw_spin_unlock_irqrestore(&desc->lock, flags);
848         if (new->thread) {
849                 struct task_struct *t = new->thread;
850
851                 new->thread = NULL;
852                 if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
853                         kthread_stop(t);
854                 put_task_struct(t);
855         }
856         return ret;
857 }
858
859 /**
860  *      setup_irq - setup an interrupt
861  *      @irq: Interrupt line to setup
862  *      @act: irqaction for the interrupt
863  *
864  * Used to statically setup interrupts in the early boot process.
865  */
866 int setup_irq(unsigned int irq, struct irqaction *act)
867 {
868         struct irq_desc *desc = irq_to_desc(irq);
869
870         return __setup_irq(irq, desc, act);
871 }
872 EXPORT_SYMBOL_GPL(setup_irq);
873
874  /*
875  * Internal function to unregister an irqaction - used to free
876  * regular and special interrupts that are part of the architecture.
877  */
878 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
879 {
880         struct irq_desc *desc = irq_to_desc(irq);
881         struct irqaction *action, **action_ptr;
882         unsigned long flags;
883
884         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
885
886         if (!desc)
887                 return NULL;
888
889         raw_spin_lock_irqsave(&desc->lock, flags);
890
891         /*
892          * There can be multiple actions per IRQ descriptor, find the right
893          * one based on the dev_id:
894          */
895         action_ptr = &desc->action;
896         for (;;) {
897                 action = *action_ptr;
898
899                 if (!action) {
900                         WARN(1, "Trying to free already-free IRQ %d\n", irq);
901                         raw_spin_unlock_irqrestore(&desc->lock, flags);
902
903                         return NULL;
904                 }
905
906                 if (action->dev_id == dev_id)
907                         break;
908                 action_ptr = &action->next;
909         }
910
911         /* Found it - now remove it from the list of entries: */
912         *action_ptr = action->next;
913
914         /* Currently used only by UML, might disappear one day: */
915 #ifdef CONFIG_IRQ_RELEASE_METHOD
916         if (desc->irq_data.chip->release)
917                 desc->irq_data.chip->release(irq, dev_id);
918 #endif
919
920         /* If this was the last handler, shut down the IRQ line: */
921         if (!desc->action) {
922                 desc->status |= IRQ_DISABLED;
923                 if (desc->irq_data.chip->irq_shutdown)
924                         desc->irq_data.chip->irq_shutdown(&desc->irq_data);
925                 else
926                         desc->irq_data.chip->irq_disable(&desc->irq_data);
927         }
928
929 #ifdef CONFIG_SMP
930         /* make sure affinity_hint is cleaned up */
931         if (WARN_ON_ONCE(desc->affinity_hint))
932                 desc->affinity_hint = NULL;
933 #endif
934
935         raw_spin_unlock_irqrestore(&desc->lock, flags);
936
937         unregister_handler_proc(irq, action);
938
939         /* Make sure it's not being used on another CPU: */
940         synchronize_irq(irq);
941
942 #ifdef CONFIG_DEBUG_SHIRQ
943         /*
944          * It's a shared IRQ -- the driver ought to be prepared for an IRQ
945          * event to happen even now it's being freed, so let's make sure that
946          * is so by doing an extra call to the handler ....
947          *
948          * ( We do this after actually deregistering it, to make sure that a
949          *   'real' IRQ doesn't run in * parallel with our fake. )
950          */
951         if (action->flags & IRQF_SHARED) {
952                 local_irq_save(flags);
953                 action->handler(irq, dev_id);
954                 local_irq_restore(flags);
955         }
956 #endif
957
958         if (action->thread) {
959                 if (!test_bit(IRQTF_DIED, &action->thread_flags))
960                         kthread_stop(action->thread);
961                 put_task_struct(action->thread);
962         }
963
964         return action;
965 }
966
967 /**
968  *      remove_irq - free an interrupt
969  *      @irq: Interrupt line to free
970  *      @act: irqaction for the interrupt
971  *
972  * Used to remove interrupts statically setup by the early boot process.
973  */
974 void remove_irq(unsigned int irq, struct irqaction *act)
975 {
976         __free_irq(irq, act->dev_id);
977 }
978 EXPORT_SYMBOL_GPL(remove_irq);
979
980 /**
981  *      free_irq - free an interrupt allocated with request_irq
982  *      @irq: Interrupt line to free
983  *      @dev_id: Device identity to free
984  *
985  *      Remove an interrupt handler. The handler is removed and if the
986  *      interrupt line is no longer in use by any driver it is disabled.
987  *      On a shared IRQ the caller must ensure the interrupt is disabled
988  *      on the card it drives before calling this function. The function
989  *      does not return until any executing interrupts for this IRQ
990  *      have completed.
991  *
992  *      This function must not be called from interrupt context.
993  */
994 void free_irq(unsigned int irq, void *dev_id)
995 {
996         struct irq_desc *desc = irq_to_desc(irq);
997
998         if (!desc)
999                 return;
1000
1001         chip_bus_lock(desc);
1002         kfree(__free_irq(irq, dev_id));
1003         chip_bus_sync_unlock(desc);
1004 }
1005 EXPORT_SYMBOL(free_irq);
1006
1007 /**
1008  *      request_threaded_irq - allocate an interrupt line
1009  *      @irq: Interrupt line to allocate
1010  *      @handler: Function to be called when the IRQ occurs.
1011  *                Primary handler for threaded interrupts
1012  *                If NULL and thread_fn != NULL the default
1013  *                primary handler is installed
1014  *      @thread_fn: Function called from the irq handler thread
1015  *                  If NULL, no irq thread is created
1016  *      @irqflags: Interrupt type flags
1017  *      @devname: An ascii name for the claiming device
1018  *      @dev_id: A cookie passed back to the handler function
1019  *
1020  *      This call allocates interrupt resources and enables the
1021  *      interrupt line and IRQ handling. From the point this
1022  *      call is made your handler function may be invoked. Since
1023  *      your handler function must clear any interrupt the board
1024  *      raises, you must take care both to initialise your hardware
1025  *      and to set up the interrupt handler in the right order.
1026  *
1027  *      If you want to set up a threaded irq handler for your device
1028  *      then you need to supply @handler and @thread_fn. @handler ist
1029  *      still called in hard interrupt context and has to check
1030  *      whether the interrupt originates from the device. If yes it
1031  *      needs to disable the interrupt on the device and return
1032  *      IRQ_WAKE_THREAD which will wake up the handler thread and run
1033  *      @thread_fn. This split handler design is necessary to support
1034  *      shared interrupts.
1035  *
1036  *      Dev_id must be globally unique. Normally the address of the
1037  *      device data structure is used as the cookie. Since the handler
1038  *      receives this value it makes sense to use it.
1039  *
1040  *      If your interrupt is shared you must pass a non NULL dev_id
1041  *      as this is required when freeing the interrupt.
1042  *
1043  *      Flags:
1044  *
1045  *      IRQF_SHARED             Interrupt is shared
1046  *      IRQF_SAMPLE_RANDOM      The interrupt can be used for entropy
1047  *      IRQF_TRIGGER_*          Specify active edge(s) or level
1048  *
1049  */
1050 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1051                          irq_handler_t thread_fn, unsigned long irqflags,
1052                          const char *devname, void *dev_id)
1053 {
1054         struct irqaction *action;
1055         struct irq_desc *desc;
1056         int retval;
1057
1058         /*
1059          * Sanity-check: shared interrupts must pass in a real dev-ID,
1060          * otherwise we'll have trouble later trying to figure out
1061          * which interrupt is which (messes up the interrupt freeing
1062          * logic etc).
1063          */
1064         if ((irqflags & IRQF_SHARED) && !dev_id)
1065                 return -EINVAL;
1066
1067         desc = irq_to_desc(irq);
1068         if (!desc)
1069                 return -EINVAL;
1070
1071         if (desc->status & IRQ_NOREQUEST)
1072                 return -EINVAL;
1073
1074         if (!handler) {
1075                 if (!thread_fn)
1076                         return -EINVAL;
1077                 handler = irq_default_primary_handler;
1078         }
1079
1080         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1081         if (!action)
1082                 return -ENOMEM;
1083
1084         action->handler = handler;
1085         action->thread_fn = thread_fn;
1086         action->flags = irqflags;
1087         action->name = devname;
1088         action->dev_id = dev_id;
1089
1090         chip_bus_lock(desc);
1091         retval = __setup_irq(irq, desc, action);
1092         chip_bus_sync_unlock(desc);
1093
1094         if (retval)
1095                 kfree(action);
1096
1097 #ifdef CONFIG_DEBUG_SHIRQ
1098         if (!retval && (irqflags & IRQF_SHARED)) {
1099                 /*
1100                  * It's a shared IRQ -- the driver ought to be prepared for it
1101                  * to happen immediately, so let's make sure....
1102                  * We disable the irq to make sure that a 'real' IRQ doesn't
1103                  * run in parallel with our fake.
1104                  */
1105                 unsigned long flags;
1106
1107                 disable_irq(irq);
1108                 local_irq_save(flags);
1109
1110                 handler(irq, dev_id);
1111
1112                 local_irq_restore(flags);
1113                 enable_irq(irq);
1114         }
1115 #endif
1116         return retval;
1117 }
1118 EXPORT_SYMBOL(request_threaded_irq);
1119
1120 /**
1121  *      request_any_context_irq - allocate an interrupt line
1122  *      @irq: Interrupt line to allocate
1123  *      @handler: Function to be called when the IRQ occurs.
1124  *                Threaded handler for threaded interrupts.
1125  *      @flags: Interrupt type flags
1126  *      @name: An ascii name for the claiming device
1127  *      @dev_id: A cookie passed back to the handler function
1128  *
1129  *      This call allocates interrupt resources and enables the
1130  *      interrupt line and IRQ handling. It selects either a
1131  *      hardirq or threaded handling method depending on the
1132  *      context.
1133  *
1134  *      On failure, it returns a negative value. On success,
1135  *      it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1136  */
1137 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1138                             unsigned long flags, const char *name, void *dev_id)
1139 {
1140         struct irq_desc *desc = irq_to_desc(irq);
1141         int ret;
1142
1143         if (!desc)
1144                 return -EINVAL;
1145
1146         if (desc->status & IRQ_NESTED_THREAD) {
1147                 ret = request_threaded_irq(irq, NULL, handler,
1148                                            flags, name, dev_id);
1149                 return !ret ? IRQC_IS_NESTED : ret;
1150         }
1151
1152         ret = request_irq(irq, handler, flags, name, dev_id);
1153         return !ret ? IRQC_IS_HARDIRQ : ret;
1154 }
1155 EXPORT_SYMBOL_GPL(request_any_context_irq);