Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux...
[linux-2.6] / kernel / irq / chip.c
1 /*
2  * linux/kernel/irq/chip.c
3  *
4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
6  *
7  * This file contains the core interrupt handling code, for irq-chip
8  * based architectures.
9  *
10  * Detailed information is available in Documentation/DocBook/genericirq
11  */
12
13 #include <linux/irq.h>
14 #include <linux/msi.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel_stat.h>
18
19 #include "internals.h"
20
21 /**
22  *      dynamic_irq_init - initialize a dynamically allocated irq
23  *      @irq:   irq number to initialize
24  */
25 void dynamic_irq_init(unsigned int irq)
26 {
27         struct irq_desc *desc;
28         unsigned long flags;
29
30         desc = irq_to_desc(irq);
31         if (!desc) {
32                 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
33                 return;
34         }
35
36         /* Ensure we don't have left over values from a previous use of this irq */
37         spin_lock_irqsave(&desc->lock, flags);
38         desc->status = IRQ_DISABLED;
39         desc->chip = &no_irq_chip;
40         desc->handle_irq = handle_bad_irq;
41         desc->depth = 1;
42         desc->msi_desc = NULL;
43         desc->handler_data = NULL;
44         desc->chip_data = NULL;
45         desc->action = NULL;
46         desc->irq_count = 0;
47         desc->irqs_unhandled = 0;
48 #ifdef CONFIG_SMP
49         cpumask_setall(&desc->affinity);
50 #endif
51         spin_unlock_irqrestore(&desc->lock, flags);
52 }
53
54 /**
55  *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
56  *      @irq:   irq number to initialize
57  */
58 void dynamic_irq_cleanup(unsigned int irq)
59 {
60         struct irq_desc *desc = irq_to_desc(irq);
61         unsigned long flags;
62
63         if (!desc) {
64                 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
65                 return;
66         }
67
68         spin_lock_irqsave(&desc->lock, flags);
69         if (desc->action) {
70                 spin_unlock_irqrestore(&desc->lock, flags);
71                 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
72                         irq);
73                 return;
74         }
75         desc->msi_desc = NULL;
76         desc->handler_data = NULL;
77         desc->chip_data = NULL;
78         desc->handle_irq = handle_bad_irq;
79         desc->chip = &no_irq_chip;
80         desc->name = NULL;
81         spin_unlock_irqrestore(&desc->lock, flags);
82 }
83
84
85 /**
86  *      set_irq_chip - set the irq chip for an irq
87  *      @irq:   irq number
88  *      @chip:  pointer to irq chip description structure
89  */
90 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
91 {
92         struct irq_desc *desc = irq_to_desc(irq);
93         unsigned long flags;
94
95         if (!desc) {
96                 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
97                 return -EINVAL;
98         }
99
100         if (!chip)
101                 chip = &no_irq_chip;
102
103         spin_lock_irqsave(&desc->lock, flags);
104         irq_chip_set_defaults(chip);
105         desc->chip = chip;
106         spin_unlock_irqrestore(&desc->lock, flags);
107
108         return 0;
109 }
110 EXPORT_SYMBOL(set_irq_chip);
111
112 /**
113  *      set_irq_type - set the irq trigger type for an irq
114  *      @irq:   irq number
115  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
116  */
117 int set_irq_type(unsigned int irq, unsigned int type)
118 {
119         struct irq_desc *desc = irq_to_desc(irq);
120         unsigned long flags;
121         int ret = -ENXIO;
122
123         if (!desc) {
124                 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
125                 return -ENODEV;
126         }
127
128         if (type == IRQ_TYPE_NONE)
129                 return 0;
130
131         spin_lock_irqsave(&desc->lock, flags);
132         ret = __irq_set_trigger(desc, irq, type);
133         spin_unlock_irqrestore(&desc->lock, flags);
134         return ret;
135 }
136 EXPORT_SYMBOL(set_irq_type);
137
138 /**
139  *      set_irq_data - set irq type data for an irq
140  *      @irq:   Interrupt number
141  *      @data:  Pointer to interrupt specific data
142  *
143  *      Set the hardware irq controller data for an irq
144  */
145 int set_irq_data(unsigned int irq, void *data)
146 {
147         struct irq_desc *desc = irq_to_desc(irq);
148         unsigned long flags;
149
150         if (!desc) {
151                 printk(KERN_ERR
152                        "Trying to install controller data for IRQ%d\n", irq);
153                 return -EINVAL;
154         }
155
156         spin_lock_irqsave(&desc->lock, flags);
157         desc->handler_data = data;
158         spin_unlock_irqrestore(&desc->lock, flags);
159         return 0;
160 }
161 EXPORT_SYMBOL(set_irq_data);
162
163 /**
164  *      set_irq_data - set irq type data for an irq
165  *      @irq:   Interrupt number
166  *      @entry: Pointer to MSI descriptor data
167  *
168  *      Set the hardware irq controller data for an irq
169  */
170 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
171 {
172         struct irq_desc *desc = irq_to_desc(irq);
173         unsigned long flags;
174
175         if (!desc) {
176                 printk(KERN_ERR
177                        "Trying to install msi data for IRQ%d\n", irq);
178                 return -EINVAL;
179         }
180
181         spin_lock_irqsave(&desc->lock, flags);
182         desc->msi_desc = entry;
183         if (entry)
184                 entry->irq = irq;
185         spin_unlock_irqrestore(&desc->lock, flags);
186         return 0;
187 }
188
189 /**
190  *      set_irq_chip_data - set irq chip data for an irq
191  *      @irq:   Interrupt number
192  *      @data:  Pointer to chip specific data
193  *
194  *      Set the hardware irq chip data for an irq
195  */
196 int set_irq_chip_data(unsigned int irq, void *data)
197 {
198         struct irq_desc *desc = irq_to_desc(irq);
199         unsigned long flags;
200
201         if (!desc) {
202                 printk(KERN_ERR
203                        "Trying to install chip data for IRQ%d\n", irq);
204                 return -EINVAL;
205         }
206
207         if (!desc->chip) {
208                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
209                 return -EINVAL;
210         }
211
212         spin_lock_irqsave(&desc->lock, flags);
213         desc->chip_data = data;
214         spin_unlock_irqrestore(&desc->lock, flags);
215
216         return 0;
217 }
218 EXPORT_SYMBOL(set_irq_chip_data);
219
220 /*
221  * default enable function
222  */
223 static void default_enable(unsigned int irq)
224 {
225         struct irq_desc *desc = irq_to_desc(irq);
226
227         desc->chip->unmask(irq);
228         desc->status &= ~IRQ_MASKED;
229 }
230
231 /*
232  * default disable function
233  */
234 static void default_disable(unsigned int irq)
235 {
236 }
237
238 /*
239  * default startup function
240  */
241 static unsigned int default_startup(unsigned int irq)
242 {
243         struct irq_desc *desc = irq_to_desc(irq);
244
245         desc->chip->enable(irq);
246         return 0;
247 }
248
249 /*
250  * default shutdown function
251  */
252 static void default_shutdown(unsigned int irq)
253 {
254         struct irq_desc *desc = irq_to_desc(irq);
255
256         desc->chip->mask(irq);
257         desc->status |= IRQ_MASKED;
258 }
259
260 /*
261  * Fixup enable/disable function pointers
262  */
263 void irq_chip_set_defaults(struct irq_chip *chip)
264 {
265         if (!chip->enable)
266                 chip->enable = default_enable;
267         if (!chip->disable)
268                 chip->disable = default_disable;
269         if (!chip->startup)
270                 chip->startup = default_startup;
271         /*
272          * We use chip->disable, when the user provided its own. When
273          * we have default_disable set for chip->disable, then we need
274          * to use default_shutdown, otherwise the irq line is not
275          * disabled on free_irq():
276          */
277         if (!chip->shutdown)
278                 chip->shutdown = chip->disable != default_disable ?
279                         chip->disable : default_shutdown;
280         if (!chip->name)
281                 chip->name = chip->typename;
282         if (!chip->end)
283                 chip->end = dummy_irq_chip.end;
284 }
285
286 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
287 {
288         if (desc->chip->mask_ack)
289                 desc->chip->mask_ack(irq);
290         else {
291                 desc->chip->mask(irq);
292                 desc->chip->ack(irq);
293         }
294 }
295
296 /**
297  *      handle_simple_irq - Simple and software-decoded IRQs.
298  *      @irq:   the interrupt number
299  *      @desc:  the interrupt description structure for this irq
300  *
301  *      Simple interrupts are either sent from a demultiplexing interrupt
302  *      handler or come from hardware, where no interrupt hardware control
303  *      is necessary.
304  *
305  *      Note: The caller is expected to handle the ack, clear, mask and
306  *      unmask issues if necessary.
307  */
308 void
309 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
310 {
311         struct irqaction *action;
312         irqreturn_t action_ret;
313
314         spin_lock(&desc->lock);
315
316         if (unlikely(desc->status & IRQ_INPROGRESS))
317                 goto out_unlock;
318         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
319         kstat_incr_irqs_this_cpu(irq, desc);
320
321         action = desc->action;
322         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
323                 goto out_unlock;
324
325         desc->status |= IRQ_INPROGRESS;
326         spin_unlock(&desc->lock);
327
328         action_ret = handle_IRQ_event(irq, action);
329         if (!noirqdebug)
330                 note_interrupt(irq, desc, action_ret);
331
332         spin_lock(&desc->lock);
333         desc->status &= ~IRQ_INPROGRESS;
334 out_unlock:
335         spin_unlock(&desc->lock);
336 }
337
338 /**
339  *      handle_level_irq - Level type irq handler
340  *      @irq:   the interrupt number
341  *      @desc:  the interrupt description structure for this irq
342  *
343  *      Level type interrupts are active as long as the hardware line has
344  *      the active level. This may require to mask the interrupt and unmask
345  *      it after the associated handler has acknowledged the device, so the
346  *      interrupt line is back to inactive.
347  */
348 void
349 handle_level_irq(unsigned int irq, struct irq_desc *desc)
350 {
351         struct irqaction *action;
352         irqreturn_t action_ret;
353
354         spin_lock(&desc->lock);
355         mask_ack_irq(desc, irq);
356
357         if (unlikely(desc->status & IRQ_INPROGRESS))
358                 goto out_unlock;
359         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
360         kstat_incr_irqs_this_cpu(irq, desc);
361
362         /*
363          * If its disabled or no action available
364          * keep it masked and get out of here
365          */
366         action = desc->action;
367         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
368                 goto out_unlock;
369
370         desc->status |= IRQ_INPROGRESS;
371         spin_unlock(&desc->lock);
372
373         action_ret = handle_IRQ_event(irq, action);
374         if (!noirqdebug)
375                 note_interrupt(irq, desc, action_ret);
376
377         spin_lock(&desc->lock);
378         desc->status &= ~IRQ_INPROGRESS;
379         if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
380                 desc->chip->unmask(irq);
381 out_unlock:
382         spin_unlock(&desc->lock);
383 }
384
385 /**
386  *      handle_fasteoi_irq - irq handler for transparent controllers
387  *      @irq:   the interrupt number
388  *      @desc:  the interrupt description structure for this irq
389  *
390  *      Only a single callback will be issued to the chip: an ->eoi()
391  *      call when the interrupt has been serviced. This enables support
392  *      for modern forms of interrupt handlers, which handle the flow
393  *      details in hardware, transparently.
394  */
395 void
396 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
397 {
398         struct irqaction *action;
399         irqreturn_t action_ret;
400
401         spin_lock(&desc->lock);
402
403         if (unlikely(desc->status & IRQ_INPROGRESS))
404                 goto out;
405
406         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
407         kstat_incr_irqs_this_cpu(irq, desc);
408
409         /*
410          * If its disabled or no action available
411          * then mask it and get out of here:
412          */
413         action = desc->action;
414         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
415                 desc->status |= IRQ_PENDING;
416                 if (desc->chip->mask)
417                         desc->chip->mask(irq);
418                 goto out;
419         }
420
421         desc->status |= IRQ_INPROGRESS;
422         desc->status &= ~IRQ_PENDING;
423         spin_unlock(&desc->lock);
424
425         action_ret = handle_IRQ_event(irq, action);
426         if (!noirqdebug)
427                 note_interrupt(irq, desc, action_ret);
428
429         spin_lock(&desc->lock);
430         desc->status &= ~IRQ_INPROGRESS;
431 out:
432         desc->chip->eoi(irq);
433
434         spin_unlock(&desc->lock);
435 }
436
437 /**
438  *      handle_edge_irq - edge type IRQ handler
439  *      @irq:   the interrupt number
440  *      @desc:  the interrupt description structure for this irq
441  *
442  *      Interrupt occures on the falling and/or rising edge of a hardware
443  *      signal. The occurence is latched into the irq controller hardware
444  *      and must be acked in order to be reenabled. After the ack another
445  *      interrupt can happen on the same source even before the first one
446  *      is handled by the assosiacted event handler. If this happens it
447  *      might be necessary to disable (mask) the interrupt depending on the
448  *      controller hardware. This requires to reenable the interrupt inside
449  *      of the loop which handles the interrupts which have arrived while
450  *      the handler was running. If all pending interrupts are handled, the
451  *      loop is left.
452  */
453 void
454 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
455 {
456         spin_lock(&desc->lock);
457
458         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
459
460         /*
461          * If we're currently running this IRQ, or its disabled,
462          * we shouldn't process the IRQ. Mark it pending, handle
463          * the necessary masking and go out
464          */
465         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
466                     !desc->action)) {
467                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
468                 mask_ack_irq(desc, irq);
469                 goto out_unlock;
470         }
471         kstat_incr_irqs_this_cpu(irq, desc);
472
473         /* Start handling the irq */
474         desc->chip->ack(irq);
475
476         /* Mark the IRQ currently in progress.*/
477         desc->status |= IRQ_INPROGRESS;
478
479         do {
480                 struct irqaction *action = desc->action;
481                 irqreturn_t action_ret;
482
483                 if (unlikely(!action)) {
484                         desc->chip->mask(irq);
485                         goto out_unlock;
486                 }
487
488                 /*
489                  * When another irq arrived while we were handling
490                  * one, we could have masked the irq.
491                  * Renable it, if it was not disabled in meantime.
492                  */
493                 if (unlikely((desc->status &
494                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
495                               (IRQ_PENDING | IRQ_MASKED))) {
496                         desc->chip->unmask(irq);
497                         desc->status &= ~IRQ_MASKED;
498                 }
499
500                 desc->status &= ~IRQ_PENDING;
501                 spin_unlock(&desc->lock);
502                 action_ret = handle_IRQ_event(irq, action);
503                 if (!noirqdebug)
504                         note_interrupt(irq, desc, action_ret);
505                 spin_lock(&desc->lock);
506
507         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
508
509         desc->status &= ~IRQ_INPROGRESS;
510 out_unlock:
511         spin_unlock(&desc->lock);
512 }
513
514 /**
515  *      handle_percpu_IRQ - Per CPU local irq handler
516  *      @irq:   the interrupt number
517  *      @desc:  the interrupt description structure for this irq
518  *
519  *      Per CPU interrupts on SMP machines without locking requirements
520  */
521 void
522 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
523 {
524         irqreturn_t action_ret;
525
526         kstat_incr_irqs_this_cpu(irq, desc);
527
528         if (desc->chip->ack)
529                 desc->chip->ack(irq);
530
531         action_ret = handle_IRQ_event(irq, desc->action);
532         if (!noirqdebug)
533                 note_interrupt(irq, desc, action_ret);
534
535         if (desc->chip->eoi)
536                 desc->chip->eoi(irq);
537 }
538
539 void
540 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
541                   const char *name)
542 {
543         struct irq_desc *desc = irq_to_desc(irq);
544         unsigned long flags;
545
546         if (!desc) {
547                 printk(KERN_ERR
548                        "Trying to install type control for IRQ%d\n", irq);
549                 return;
550         }
551
552         if (!handle)
553                 handle = handle_bad_irq;
554         else if (desc->chip == &no_irq_chip) {
555                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
556                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
557                 /*
558                  * Some ARM implementations install a handler for really dumb
559                  * interrupt hardware without setting an irq_chip. This worked
560                  * with the ARM no_irq_chip but the check in setup_irq would
561                  * prevent us to setup the interrupt at all. Switch it to
562                  * dummy_irq_chip for easy transition.
563                  */
564                 desc->chip = &dummy_irq_chip;
565         }
566
567         spin_lock_irqsave(&desc->lock, flags);
568
569         /* Uninstall? */
570         if (handle == handle_bad_irq) {
571                 if (desc->chip != &no_irq_chip)
572                         mask_ack_irq(desc, irq);
573                 desc->status |= IRQ_DISABLED;
574                 desc->depth = 1;
575         }
576         desc->handle_irq = handle;
577         desc->name = name;
578
579         if (handle != handle_bad_irq && is_chained) {
580                 desc->status &= ~IRQ_DISABLED;
581                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
582                 desc->depth = 0;
583                 desc->chip->startup(irq);
584         }
585         spin_unlock_irqrestore(&desc->lock, flags);
586 }
587
588 void
589 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
590                          irq_flow_handler_t handle)
591 {
592         set_irq_chip(irq, chip);
593         __set_irq_handler(irq, handle, 0, NULL);
594 }
595
596 void
597 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
598                               irq_flow_handler_t handle, const char *name)
599 {
600         set_irq_chip(irq, chip);
601         __set_irq_handler(irq, handle, 0, name);
602 }
603
604 void __init set_irq_noprobe(unsigned int irq)
605 {
606         struct irq_desc *desc = irq_to_desc(irq);
607         unsigned long flags;
608
609         if (!desc) {
610                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
611                 return;
612         }
613
614         spin_lock_irqsave(&desc->lock, flags);
615         desc->status |= IRQ_NOPROBE;
616         spin_unlock_irqrestore(&desc->lock, flags);
617 }
618
619 void __init set_irq_probe(unsigned int irq)
620 {
621         struct irq_desc *desc = irq_to_desc(irq);
622         unsigned long flags;
623
624         if (!desc) {
625                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
626                 return;
627         }
628
629         spin_lock_irqsave(&desc->lock, flags);
630         desc->status &= ~IRQ_NOPROBE;
631         spin_unlock_irqrestore(&desc->lock, flags);
632 }