Merge branch 'linus' into irq/genirq
[linux-2.6.git] / 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         type &= IRQ_TYPE_SENSE_MASK;
129         if (type == IRQ_TYPE_NONE)
130                 return 0;
131
132         spin_lock_irqsave(&desc->lock, flags);
133         ret = __irq_set_trigger(desc, irq, type);
134         spin_unlock_irqrestore(&desc->lock, flags);
135         return ret;
136 }
137 EXPORT_SYMBOL(set_irq_type);
138
139 /**
140  *      set_irq_data - set irq type data for an irq
141  *      @irq:   Interrupt number
142  *      @data:  Pointer to interrupt specific data
143  *
144  *      Set the hardware irq controller data for an irq
145  */
146 int set_irq_data(unsigned int irq, void *data)
147 {
148         struct irq_desc *desc = irq_to_desc(irq);
149         unsigned long flags;
150
151         if (!desc) {
152                 printk(KERN_ERR
153                        "Trying to install controller data for IRQ%d\n", irq);
154                 return -EINVAL;
155         }
156
157         spin_lock_irqsave(&desc->lock, flags);
158         desc->handler_data = data;
159         spin_unlock_irqrestore(&desc->lock, flags);
160         return 0;
161 }
162 EXPORT_SYMBOL(set_irq_data);
163
164 /**
165  *      set_irq_data - set irq type data for an irq
166  *      @irq:   Interrupt number
167  *      @entry: Pointer to MSI descriptor data
168  *
169  *      Set the hardware irq controller data for an irq
170  */
171 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
172 {
173         struct irq_desc *desc = irq_to_desc(irq);
174         unsigned long flags;
175
176         if (!desc) {
177                 printk(KERN_ERR
178                        "Trying to install msi data for IRQ%d\n", irq);
179                 return -EINVAL;
180         }
181
182         spin_lock_irqsave(&desc->lock, flags);
183         desc->msi_desc = entry;
184         if (entry)
185                 entry->irq = irq;
186         spin_unlock_irqrestore(&desc->lock, flags);
187         return 0;
188 }
189
190 /**
191  *      set_irq_chip_data - set irq chip data for an irq
192  *      @irq:   Interrupt number
193  *      @data:  Pointer to chip specific data
194  *
195  *      Set the hardware irq chip data for an irq
196  */
197 int set_irq_chip_data(unsigned int irq, void *data)
198 {
199         struct irq_desc *desc = irq_to_desc(irq);
200         unsigned long flags;
201
202         if (!desc) {
203                 printk(KERN_ERR
204                        "Trying to install chip data for IRQ%d\n", irq);
205                 return -EINVAL;
206         }
207
208         if (!desc->chip) {
209                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
210                 return -EINVAL;
211         }
212
213         spin_lock_irqsave(&desc->lock, flags);
214         desc->chip_data = data;
215         spin_unlock_irqrestore(&desc->lock, flags);
216
217         return 0;
218 }
219 EXPORT_SYMBOL(set_irq_chip_data);
220
221 /*
222  * default enable function
223  */
224 static void default_enable(unsigned int irq)
225 {
226         struct irq_desc *desc = irq_to_desc(irq);
227
228         desc->chip->unmask(irq);
229         desc->status &= ~IRQ_MASKED;
230 }
231
232 /*
233  * default disable function
234  */
235 static void default_disable(unsigned int irq)
236 {
237 }
238
239 /*
240  * default startup function
241  */
242 static unsigned int default_startup(unsigned int irq)
243 {
244         struct irq_desc *desc = irq_to_desc(irq);
245
246         desc->chip->enable(irq);
247         return 0;
248 }
249
250 /*
251  * default shutdown function
252  */
253 static void default_shutdown(unsigned int irq)
254 {
255         struct irq_desc *desc = irq_to_desc(irq);
256
257         desc->chip->mask(irq);
258         desc->status |= IRQ_MASKED;
259 }
260
261 /*
262  * Fixup enable/disable function pointers
263  */
264 void irq_chip_set_defaults(struct irq_chip *chip)
265 {
266         if (!chip->enable)
267                 chip->enable = default_enable;
268         if (!chip->disable)
269                 chip->disable = default_disable;
270         if (!chip->startup)
271                 chip->startup = default_startup;
272         /*
273          * We use chip->disable, when the user provided its own. When
274          * we have default_disable set for chip->disable, then we need
275          * to use default_shutdown, otherwise the irq line is not
276          * disabled on free_irq():
277          */
278         if (!chip->shutdown)
279                 chip->shutdown = chip->disable != default_disable ?
280                         chip->disable : default_shutdown;
281         if (!chip->name)
282                 chip->name = chip->typename;
283         if (!chip->end)
284                 chip->end = dummy_irq_chip.end;
285 }
286
287 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
288 {
289         if (desc->chip->mask_ack)
290                 desc->chip->mask_ack(irq);
291         else {
292                 desc->chip->mask(irq);
293                 if (desc->chip->ack)
294                         desc->chip->ack(irq);
295         }
296 }
297
298 /**
299  *      handle_simple_irq - Simple and software-decoded IRQs.
300  *      @irq:   the interrupt number
301  *      @desc:  the interrupt description structure for this irq
302  *
303  *      Simple interrupts are either sent from a demultiplexing interrupt
304  *      handler or come from hardware, where no interrupt hardware control
305  *      is necessary.
306  *
307  *      Note: The caller is expected to handle the ack, clear, mask and
308  *      unmask issues if necessary.
309  */
310 void
311 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
312 {
313         struct irqaction *action;
314         irqreturn_t action_ret;
315
316         spin_lock(&desc->lock);
317
318         if (unlikely(desc->status & IRQ_INPROGRESS))
319                 goto out_unlock;
320         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
321         kstat_incr_irqs_this_cpu(irq, desc);
322
323         action = desc->action;
324         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
325                 goto out_unlock;
326
327         desc->status |= IRQ_INPROGRESS;
328         spin_unlock(&desc->lock);
329
330         action_ret = handle_IRQ_event(irq, action);
331         if (!noirqdebug)
332                 note_interrupt(irq, desc, action_ret);
333
334         spin_lock(&desc->lock);
335         desc->status &= ~IRQ_INPROGRESS;
336 out_unlock:
337         spin_unlock(&desc->lock);
338 }
339
340 /**
341  *      handle_level_irq - Level type irq handler
342  *      @irq:   the interrupt number
343  *      @desc:  the interrupt description structure for this irq
344  *
345  *      Level type interrupts are active as long as the hardware line has
346  *      the active level. This may require to mask the interrupt and unmask
347  *      it after the associated handler has acknowledged the device, so the
348  *      interrupt line is back to inactive.
349  */
350 void
351 handle_level_irq(unsigned int irq, struct irq_desc *desc)
352 {
353         struct irqaction *action;
354         irqreturn_t action_ret;
355
356         spin_lock(&desc->lock);
357         mask_ack_irq(desc, irq);
358         desc = irq_remap_to_desc(irq, desc);
359
360         if (unlikely(desc->status & IRQ_INPROGRESS))
361                 goto out_unlock;
362         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
363         kstat_incr_irqs_this_cpu(irq, desc);
364
365         /*
366          * If its disabled or no action available
367          * keep it masked and get out of here
368          */
369         action = desc->action;
370         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
371                 goto out_unlock;
372
373         desc->status |= IRQ_INPROGRESS;
374         spin_unlock(&desc->lock);
375
376         action_ret = handle_IRQ_event(irq, action);
377         if (!noirqdebug)
378                 note_interrupt(irq, desc, action_ret);
379
380         spin_lock(&desc->lock);
381         desc->status &= ~IRQ_INPROGRESS;
382         if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
383                 desc->chip->unmask(irq);
384 out_unlock:
385         spin_unlock(&desc->lock);
386 }
387
388 /**
389  *      handle_fasteoi_irq - irq handler for transparent controllers
390  *      @irq:   the interrupt number
391  *      @desc:  the interrupt description structure for this irq
392  *
393  *      Only a single callback will be issued to the chip: an ->eoi()
394  *      call when the interrupt has been serviced. This enables support
395  *      for modern forms of interrupt handlers, which handle the flow
396  *      details in hardware, transparently.
397  */
398 void
399 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
400 {
401         struct irqaction *action;
402         irqreturn_t action_ret;
403
404         spin_lock(&desc->lock);
405
406         if (unlikely(desc->status & IRQ_INPROGRESS))
407                 goto out;
408
409         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
410         kstat_incr_irqs_this_cpu(irq, desc);
411
412         /*
413          * If its disabled or no action available
414          * then mask it and get out of here:
415          */
416         action = desc->action;
417         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
418                 desc->status |= IRQ_PENDING;
419                 if (desc->chip->mask)
420                         desc->chip->mask(irq);
421                 goto out;
422         }
423
424         desc->status |= IRQ_INPROGRESS;
425         desc->status &= ~IRQ_PENDING;
426         spin_unlock(&desc->lock);
427
428         action_ret = handle_IRQ_event(irq, action);
429         if (!noirqdebug)
430                 note_interrupt(irq, desc, action_ret);
431
432         spin_lock(&desc->lock);
433         desc->status &= ~IRQ_INPROGRESS;
434 out:
435         desc->chip->eoi(irq);
436         desc = irq_remap_to_desc(irq, desc);
437
438         spin_unlock(&desc->lock);
439 }
440
441 /**
442  *      handle_edge_irq - edge type IRQ handler
443  *      @irq:   the interrupt number
444  *      @desc:  the interrupt description structure for this irq
445  *
446  *      Interrupt occures on the falling and/or rising edge of a hardware
447  *      signal. The occurence is latched into the irq controller hardware
448  *      and must be acked in order to be reenabled. After the ack another
449  *      interrupt can happen on the same source even before the first one
450  *      is handled by the assosiacted event handler. If this happens it
451  *      might be necessary to disable (mask) the interrupt depending on the
452  *      controller hardware. This requires to reenable the interrupt inside
453  *      of the loop which handles the interrupts which have arrived while
454  *      the handler was running. If all pending interrupts are handled, the
455  *      loop is left.
456  */
457 void
458 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
459 {
460         spin_lock(&desc->lock);
461
462         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
463
464         /*
465          * If we're currently running this IRQ, or its disabled,
466          * we shouldn't process the IRQ. Mark it pending, handle
467          * the necessary masking and go out
468          */
469         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
470                     !desc->action)) {
471                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
472                 mask_ack_irq(desc, irq);
473                 desc = irq_remap_to_desc(irq, desc);
474                 goto out_unlock;
475         }
476         kstat_incr_irqs_this_cpu(irq, desc);
477
478         /* Start handling the irq */
479         if (desc->chip->ack)
480                 desc->chip->ack(irq);
481         desc = irq_remap_to_desc(irq, desc);
482
483         /* Mark the IRQ currently in progress.*/
484         desc->status |= IRQ_INPROGRESS;
485
486         do {
487                 struct irqaction *action = desc->action;
488                 irqreturn_t action_ret;
489
490                 if (unlikely(!action)) {
491                         desc->chip->mask(irq);
492                         goto out_unlock;
493                 }
494
495                 /*
496                  * When another irq arrived while we were handling
497                  * one, we could have masked the irq.
498                  * Renable it, if it was not disabled in meantime.
499                  */
500                 if (unlikely((desc->status &
501                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
502                               (IRQ_PENDING | IRQ_MASKED))) {
503                         desc->chip->unmask(irq);
504                         desc->status &= ~IRQ_MASKED;
505                 }
506
507                 desc->status &= ~IRQ_PENDING;
508                 spin_unlock(&desc->lock);
509                 action_ret = handle_IRQ_event(irq, action);
510                 if (!noirqdebug)
511                         note_interrupt(irq, desc, action_ret);
512                 spin_lock(&desc->lock);
513
514         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
515
516         desc->status &= ~IRQ_INPROGRESS;
517 out_unlock:
518         spin_unlock(&desc->lock);
519 }
520
521 /**
522  *      handle_percpu_IRQ - Per CPU local irq handler
523  *      @irq:   the interrupt number
524  *      @desc:  the interrupt description structure for this irq
525  *
526  *      Per CPU interrupts on SMP machines without locking requirements
527  */
528 void
529 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
530 {
531         irqreturn_t action_ret;
532
533         kstat_incr_irqs_this_cpu(irq, desc);
534
535         if (desc->chip->ack)
536                 desc->chip->ack(irq);
537
538         action_ret = handle_IRQ_event(irq, desc->action);
539         if (!noirqdebug)
540                 note_interrupt(irq, desc, action_ret);
541
542         if (desc->chip->eoi) {
543                 desc->chip->eoi(irq);
544                 desc = irq_remap_to_desc(irq, desc);
545         }
546 }
547
548 void
549 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
550                   const char *name)
551 {
552         struct irq_desc *desc = irq_to_desc(irq);
553         unsigned long flags;
554
555         if (!desc) {
556                 printk(KERN_ERR
557                        "Trying to install type control for IRQ%d\n", irq);
558                 return;
559         }
560
561         if (!handle)
562                 handle = handle_bad_irq;
563         else if (desc->chip == &no_irq_chip) {
564                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
565                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
566                 /*
567                  * Some ARM implementations install a handler for really dumb
568                  * interrupt hardware without setting an irq_chip. This worked
569                  * with the ARM no_irq_chip but the check in setup_irq would
570                  * prevent us to setup the interrupt at all. Switch it to
571                  * dummy_irq_chip for easy transition.
572                  */
573                 desc->chip = &dummy_irq_chip;
574         }
575
576         spin_lock_irqsave(&desc->lock, flags);
577
578         /* Uninstall? */
579         if (handle == handle_bad_irq) {
580                 if (desc->chip != &no_irq_chip) {
581                         mask_ack_irq(desc, irq);
582                         desc = irq_remap_to_desc(irq, desc);
583                 }
584                 desc->status |= IRQ_DISABLED;
585                 desc->depth = 1;
586         }
587         desc->handle_irq = handle;
588         desc->name = name;
589
590         if (handle != handle_bad_irq && is_chained) {
591                 desc->status &= ~IRQ_DISABLED;
592                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
593                 desc->depth = 0;
594                 desc->chip->startup(irq);
595         }
596         spin_unlock_irqrestore(&desc->lock, flags);
597 }
598
599 void
600 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
601                          irq_flow_handler_t handle)
602 {
603         set_irq_chip(irq, chip);
604         __set_irq_handler(irq, handle, 0, NULL);
605 }
606
607 void
608 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
609                               irq_flow_handler_t handle, const char *name)
610 {
611         set_irq_chip(irq, chip);
612         __set_irq_handler(irq, handle, 0, name);
613 }
614
615 void __init set_irq_noprobe(unsigned int irq)
616 {
617         struct irq_desc *desc = irq_to_desc(irq);
618         unsigned long flags;
619
620         if (!desc) {
621                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
622                 return;
623         }
624
625         spin_lock_irqsave(&desc->lock, flags);
626         desc->status |= IRQ_NOPROBE;
627         spin_unlock_irqrestore(&desc->lock, flags);
628 }
629
630 void __init set_irq_probe(unsigned int irq)
631 {
632         struct irq_desc *desc = irq_to_desc(irq);
633         unsigned long flags;
634
635         if (!desc) {
636                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
637                 return;
638         }
639
640         spin_lock_irqsave(&desc->lock, flags);
641         desc->status &= ~IRQ_NOPROBE;
642         spin_unlock_irqrestore(&desc->lock, flags);
643 }