570d1ea1db5daee44bff774b3e8cc8a37b717f1b
[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         /* first time to use this irq_desc */
31         desc = irq_to_desc_alloc(irq);
32         if (!desc) {
33                 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
34                 return;
35         }
36
37         /* Ensure we don't have left over values from a previous use of this irq */
38         spin_lock_irqsave(&desc->lock, flags);
39         desc->status = IRQ_DISABLED;
40         desc->chip = &no_irq_chip;
41         desc->handle_irq = handle_bad_irq;
42         desc->depth = 1;
43         desc->msi_desc = NULL;
44         desc->handler_data = NULL;
45         desc->chip_data = NULL;
46         desc->action = NULL;
47         desc->irq_count = 0;
48         desc->irqs_unhandled = 0;
49 #ifdef CONFIG_SMP
50         cpus_setall(desc->affinity);
51 #endif
52         spin_unlock_irqrestore(&desc->lock, flags);
53 }
54
55 /**
56  *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
57  *      @irq:   irq number to initialize
58  */
59 void dynamic_irq_cleanup(unsigned int irq)
60 {
61         struct irq_desc *desc;
62         unsigned long flags;
63
64         desc = irq_to_desc(irq);
65         if (!desc) {
66                 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
67                 return;
68         }
69
70         spin_lock_irqsave(&desc->lock, flags);
71         if (desc->action) {
72                 spin_unlock_irqrestore(&desc->lock, flags);
73                 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
74                         irq);
75                 return;
76         }
77         desc->msi_desc = NULL;
78         desc->handler_data = NULL;
79         desc->chip_data = NULL;
80         desc->handle_irq = handle_bad_irq;
81         desc->chip = &no_irq_chip;
82         spin_unlock_irqrestore(&desc->lock, flags);
83 }
84
85
86 /**
87  *      set_irq_chip - set the irq chip for an irq
88  *      @irq:   irq number
89  *      @chip:  pointer to irq chip description structure
90  */
91 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
92 {
93         struct irq_desc *desc;
94         unsigned long flags;
95
96         desc = irq_to_desc(irq);
97         if (!desc) {
98                 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
99                 return -EINVAL;
100         }
101
102         if (!chip)
103                 chip = &no_irq_chip;
104
105         spin_lock_irqsave(&desc->lock, flags);
106         irq_chip_set_defaults(chip);
107         desc->chip = chip;
108         spin_unlock_irqrestore(&desc->lock, flags);
109
110         return 0;
111 }
112 EXPORT_SYMBOL(set_irq_chip);
113
114 /**
115  *      set_irq_type - set the irq trigger type for an irq
116  *      @irq:   irq number
117  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
118  */
119 int set_irq_type(unsigned int irq, unsigned int type)
120 {
121         struct irq_desc *desc;
122         unsigned long flags;
123         int ret = -ENXIO;
124
125         desc = irq_to_desc(irq);
126         if (!desc) {
127                 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
128                 return -ENODEV;
129         }
130
131         if (type == IRQ_TYPE_NONE)
132                 return 0;
133
134         spin_lock_irqsave(&desc->lock, flags);
135         ret = __irq_set_trigger(desc, irq, flags);
136         spin_unlock_irqrestore(&desc->lock, flags);
137         return ret;
138 }
139 EXPORT_SYMBOL(set_irq_type);
140
141 /**
142  *      set_irq_data - set irq type data for an irq
143  *      @irq:   Interrupt number
144  *      @data:  Pointer to interrupt specific data
145  *
146  *      Set the hardware irq controller data for an irq
147  */
148 int set_irq_data(unsigned int irq, void *data)
149 {
150         struct irq_desc *desc;
151         unsigned long flags;
152
153         desc = irq_to_desc(irq);
154         if (!desc) {
155                 printk(KERN_ERR
156                        "Trying to install controller data for IRQ%d\n", irq);
157                 return -EINVAL;
158         }
159
160         spin_lock_irqsave(&desc->lock, flags);
161         desc->handler_data = data;
162         spin_unlock_irqrestore(&desc->lock, flags);
163         return 0;
164 }
165 EXPORT_SYMBOL(set_irq_data);
166
167 /**
168  *      set_irq_data - set irq type data for an irq
169  *      @irq:   Interrupt number
170  *      @entry: Pointer to MSI descriptor data
171  *
172  *      Set the hardware irq controller data for an irq
173  */
174 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
175 {
176         struct irq_desc *desc;
177         unsigned long flags;
178
179         desc = irq_to_desc(irq);
180         if (!desc) {
181                 printk(KERN_ERR
182                        "Trying to install msi data for IRQ%d\n", irq);
183                 return -EINVAL;
184         }
185
186         spin_lock_irqsave(&desc->lock, flags);
187         desc->msi_desc = entry;
188         if (entry)
189                 entry->irq = irq;
190         spin_unlock_irqrestore(&desc->lock, flags);
191         return 0;
192 }
193
194 /**
195  *      set_irq_chip_data - set irq chip data for an irq
196  *      @irq:   Interrupt number
197  *      @data:  Pointer to chip specific data
198  *
199  *      Set the hardware irq chip data for an irq
200  */
201 int set_irq_chip_data(unsigned int irq, void *data)
202 {
203         struct irq_desc *desc;
204         unsigned long flags;
205
206         desc = irq_to_desc(irq);
207         if (!desc) {
208                 printk(KERN_ERR
209                        "Trying to install chip data for IRQ%d\n", irq);
210                 return -EINVAL;
211         }
212
213         if (!desc->chip) {
214                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
215                 return -EINVAL;
216         }
217
218         spin_lock_irqsave(&desc->lock, flags);
219         desc->chip_data = data;
220         spin_unlock_irqrestore(&desc->lock, flags);
221
222         return 0;
223 }
224 EXPORT_SYMBOL(set_irq_chip_data);
225
226 /*
227  * default enable function
228  */
229 static void default_enable(unsigned int irq)
230 {
231         struct irq_desc *desc;
232
233         desc = irq_to_desc(irq);
234         desc->chip->unmask(irq);
235         desc->status &= ~IRQ_MASKED;
236 }
237
238 /*
239  * default disable function
240  */
241 static void default_disable(unsigned int irq)
242 {
243 }
244
245 /*
246  * default startup function
247  */
248 static unsigned int default_startup(unsigned int irq)
249 {
250         struct irq_desc *desc;
251
252         desc = irq_to_desc(irq);
253         desc->chip->enable(irq);
254
255         return 0;
256 }
257
258 /*
259  * default shutdown function
260  */
261 static void default_shutdown(unsigned int irq)
262 {
263         struct irq_desc *desc;
264
265         desc = irq_to_desc(irq);
266         desc->chip->mask(irq);
267         desc->status |= IRQ_MASKED;
268 }
269
270 /*
271  * Fixup enable/disable function pointers
272  */
273 void irq_chip_set_defaults(struct irq_chip *chip)
274 {
275         if (!chip->enable)
276                 chip->enable = default_enable;
277         if (!chip->disable)
278                 chip->disable = default_disable;
279         if (!chip->startup)
280                 chip->startup = default_startup;
281         /*
282          * We use chip->disable, when the user provided its own. When
283          * we have default_disable set for chip->disable, then we need
284          * to use default_shutdown, otherwise the irq line is not
285          * disabled on free_irq():
286          */
287         if (!chip->shutdown)
288                 chip->shutdown = chip->disable != default_disable ?
289                         chip->disable : default_shutdown;
290         if (!chip->name)
291                 chip->name = chip->typename;
292         if (!chip->end)
293                 chip->end = dummy_irq_chip.end;
294 }
295
296 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
297 {
298         if (desc->chip->mask_ack)
299                 desc->chip->mask_ack(irq);
300         else {
301                 desc->chip->mask(irq);
302                 desc->chip->ack(irq);
303         }
304 }
305
306 /**
307  *      handle_simple_irq - Simple and software-decoded IRQs.
308  *      @irq:   the interrupt number
309  *      @desc:  the interrupt description structure for this irq
310  *
311  *      Simple interrupts are either sent from a demultiplexing interrupt
312  *      handler or come from hardware, where no interrupt hardware control
313  *      is necessary.
314  *
315  *      Note: The caller is expected to handle the ack, clear, mask and
316  *      unmask issues if necessary.
317  */
318 void
319 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
320 {
321         struct irqaction *action;
322         irqreturn_t action_ret;
323
324         spin_lock(&desc->lock);
325
326         if (unlikely(desc->status & IRQ_INPROGRESS))
327                 goto out_unlock;
328         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
329 #ifdef CONFIG_HAVE_DYN_ARRAY
330         kstat_irqs_this_cpu(desc)++;
331 #else
332         kstat_irqs_this_cpu(irq)++;
333 #endif
334
335         action = desc->action;
336         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
337                 goto out_unlock;
338
339         desc->status |= IRQ_INPROGRESS;
340         spin_unlock(&desc->lock);
341
342         action_ret = handle_IRQ_event(irq, action);
343         if (!noirqdebug)
344                 note_interrupt(irq, desc, action_ret);
345
346         spin_lock(&desc->lock);
347         desc->status &= ~IRQ_INPROGRESS;
348 out_unlock:
349         spin_unlock(&desc->lock);
350 }
351
352 /**
353  *      handle_level_irq - Level type irq handler
354  *      @irq:   the interrupt number
355  *      @desc:  the interrupt description structure for this irq
356  *
357  *      Level type interrupts are active as long as the hardware line has
358  *      the active level. This may require to mask the interrupt and unmask
359  *      it after the associated handler has acknowledged the device, so the
360  *      interrupt line is back to inactive.
361  */
362 void
363 handle_level_irq(unsigned int irq, struct irq_desc *desc)
364 {
365         struct irqaction *action;
366         irqreturn_t action_ret;
367
368         spin_lock(&desc->lock);
369         mask_ack_irq(desc, irq);
370
371         if (unlikely(desc->status & IRQ_INPROGRESS))
372                 goto out_unlock;
373         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
374 #ifdef CONFIG_HAVE_DYN_ARRAY
375         kstat_irqs_this_cpu(desc)++;
376 #else
377         kstat_irqs_this_cpu(irq)++;
378 #endif
379
380         /*
381          * If its disabled or no action available
382          * keep it masked and get out of here
383          */
384         action = desc->action;
385         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
386                 goto out_unlock;
387
388         desc->status |= IRQ_INPROGRESS;
389         spin_unlock(&desc->lock);
390
391         action_ret = handle_IRQ_event(irq, action);
392         if (!noirqdebug)
393                 note_interrupt(irq, desc, action_ret);
394
395         spin_lock(&desc->lock);
396         desc->status &= ~IRQ_INPROGRESS;
397         if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
398                 desc->chip->unmask(irq);
399 out_unlock:
400         spin_unlock(&desc->lock);
401 }
402
403 /**
404  *      handle_fasteoi_irq - irq handler for transparent controllers
405  *      @irq:   the interrupt number
406  *      @desc:  the interrupt description structure for this irq
407  *
408  *      Only a single callback will be issued to the chip: an ->eoi()
409  *      call when the interrupt has been serviced. This enables support
410  *      for modern forms of interrupt handlers, which handle the flow
411  *      details in hardware, transparently.
412  */
413 void
414 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
415 {
416         struct irqaction *action;
417         irqreturn_t action_ret;
418
419         spin_lock(&desc->lock);
420
421         if (unlikely(desc->status & IRQ_INPROGRESS))
422                 goto out;
423
424         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
425 #ifdef CONFIG_HAVE_DYN_ARRAY
426         kstat_irqs_this_cpu(desc)++;
427 #else
428         kstat_irqs_this_cpu(irq)++;
429 #endif
430
431         /*
432          * If its disabled or no action available
433          * then mask it and get out of here:
434          */
435         action = desc->action;
436         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
437                 desc->status |= IRQ_PENDING;
438                 if (desc->chip->mask)
439                         desc->chip->mask(irq);
440                 goto out;
441         }
442
443         desc->status |= IRQ_INPROGRESS;
444         desc->status &= ~IRQ_PENDING;
445         spin_unlock(&desc->lock);
446
447         action_ret = handle_IRQ_event(irq, action);
448         if (!noirqdebug)
449                 note_interrupt(irq, desc, action_ret);
450
451         spin_lock(&desc->lock);
452         desc->status &= ~IRQ_INPROGRESS;
453 out:
454         desc->chip->eoi(irq);
455
456         spin_unlock(&desc->lock);
457 }
458
459 /**
460  *      handle_edge_irq - edge type IRQ handler
461  *      @irq:   the interrupt number
462  *      @desc:  the interrupt description structure for this irq
463  *
464  *      Interrupt occures on the falling and/or rising edge of a hardware
465  *      signal. The occurence is latched into the irq controller hardware
466  *      and must be acked in order to be reenabled. After the ack another
467  *      interrupt can happen on the same source even before the first one
468  *      is handled by the assosiacted event handler. If this happens it
469  *      might be necessary to disable (mask) the interrupt depending on the
470  *      controller hardware. This requires to reenable the interrupt inside
471  *      of the loop which handles the interrupts which have arrived while
472  *      the handler was running. If all pending interrupts are handled, the
473  *      loop is left.
474  */
475 void
476 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
477 {
478         spin_lock(&desc->lock);
479
480         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
481
482         /*
483          * If we're currently running this IRQ, or its disabled,
484          * we shouldn't process the IRQ. Mark it pending, handle
485          * the necessary masking and go out
486          */
487         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
488                     !desc->action)) {
489                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
490                 mask_ack_irq(desc, irq);
491                 goto out_unlock;
492         }
493 #ifdef CONFIG_HAVE_DYN_ARRAY
494         kstat_irqs_this_cpu(desc)++;
495 #else
496         kstat_irqs_this_cpu(irq)++;
497 #endif
498
499         /* Start handling the irq */
500         desc->chip->ack(irq);
501
502         /* Mark the IRQ currently in progress.*/
503         desc->status |= IRQ_INPROGRESS;
504
505         do {
506                 struct irqaction *action = desc->action;
507                 irqreturn_t action_ret;
508
509                 if (unlikely(!action)) {
510                         desc->chip->mask(irq);
511                         goto out_unlock;
512                 }
513
514                 /*
515                  * When another irq arrived while we were handling
516                  * one, we could have masked the irq.
517                  * Renable it, if it was not disabled in meantime.
518                  */
519                 if (unlikely((desc->status &
520                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
521                               (IRQ_PENDING | IRQ_MASKED))) {
522                         desc->chip->unmask(irq);
523                         desc->status &= ~IRQ_MASKED;
524                 }
525
526                 desc->status &= ~IRQ_PENDING;
527                 spin_unlock(&desc->lock);
528                 action_ret = handle_IRQ_event(irq, action);
529                 if (!noirqdebug)
530                         note_interrupt(irq, desc, action_ret);
531                 spin_lock(&desc->lock);
532
533         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
534
535         desc->status &= ~IRQ_INPROGRESS;
536 out_unlock:
537         spin_unlock(&desc->lock);
538 }
539
540 /**
541  *      handle_percpu_IRQ - Per CPU local irq handler
542  *      @irq:   the interrupt number
543  *      @desc:  the interrupt description structure for this irq
544  *
545  *      Per CPU interrupts on SMP machines without locking requirements
546  */
547 void
548 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
549 {
550         irqreturn_t action_ret;
551
552 #ifdef CONFIG_HAVE_DYN_ARRAY
553         kstat_irqs_this_cpu(desc)++;
554 #else
555         kstat_irqs_this_cpu(irq)++;
556 #endif
557
558         if (desc->chip->ack)
559                 desc->chip->ack(irq);
560
561         action_ret = handle_IRQ_event(irq, desc->action);
562         if (!noirqdebug)
563                 note_interrupt(irq, desc, action_ret);
564
565         if (desc->chip->eoi)
566                 desc->chip->eoi(irq);
567 }
568
569 void
570 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
571                   const char *name)
572 {
573         struct irq_desc *desc;
574         unsigned long flags;
575
576         desc = irq_to_desc(irq);
577         if (!desc) {
578                 printk(KERN_ERR
579                        "Trying to install type control for IRQ%d\n", irq);
580                 return;
581         }
582
583         if (!handle)
584                 handle = handle_bad_irq;
585         else if (desc->chip == &no_irq_chip) {
586                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
587                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
588                 /*
589                  * Some ARM implementations install a handler for really dumb
590                  * interrupt hardware without setting an irq_chip. This worked
591                  * with the ARM no_irq_chip but the check in setup_irq would
592                  * prevent us to setup the interrupt at all. Switch it to
593                  * dummy_irq_chip for easy transition.
594                  */
595                 desc->chip = &dummy_irq_chip;
596         }
597
598         spin_lock_irqsave(&desc->lock, flags);
599
600         /* Uninstall? */
601         if (handle == handle_bad_irq) {
602                 if (desc->chip != &no_irq_chip)
603                         mask_ack_irq(desc, irq);
604                 desc->status |= IRQ_DISABLED;
605                 desc->depth = 1;
606         }
607         desc->handle_irq = handle;
608         desc->name = name;
609
610         if (handle != handle_bad_irq && is_chained) {
611                 desc->status &= ~IRQ_DISABLED;
612                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
613                 desc->depth = 0;
614                 desc->chip->startup(irq);
615         }
616         spin_unlock_irqrestore(&desc->lock, flags);
617 }
618
619 void
620 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
621                          irq_flow_handler_t handle)
622 {
623         set_irq_chip(irq, chip);
624         __set_irq_handler(irq, handle, 0, NULL);
625 }
626
627 void
628 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
629                               irq_flow_handler_t handle, const char *name)
630 {
631         set_irq_chip(irq, chip);
632         __set_irq_handler(irq, handle, 0, name);
633 }
634
635 void __init set_irq_noprobe(unsigned int irq)
636 {
637         struct irq_desc *desc;
638         unsigned long flags;
639
640         desc = irq_to_desc(irq);
641         if (!desc) {
642                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
643
644                 return;
645         }
646
647         spin_lock_irqsave(&desc->lock, flags);
648         desc->status |= IRQ_NOPROBE;
649         spin_unlock_irqrestore(&desc->lock, flags);
650 }
651
652 void __init set_irq_probe(unsigned int irq)
653 {
654         struct irq_desc *desc;
655         unsigned long flags;
656
657         desc = irq_to_desc(irq);
658         if (!desc) {
659                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
660
661                 return;
662         }
663
664         spin_lock_irqsave(&desc->lock, flags);
665         desc->status &= ~IRQ_NOPROBE;
666         spin_unlock_irqrestore(&desc->lock, flags);
667 }