irq: clear kstat_irqs
[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         clear_kstat_irqs(desc);
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 = irq_to_desc(irq);
94         unsigned long flags;
95
96         if (!desc) {
97                 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
98                 return -EINVAL;
99         }
100
101         if (!chip)
102                 chip = &no_irq_chip;
103
104         spin_lock_irqsave(&desc->lock, flags);
105         irq_chip_set_defaults(chip);
106         desc->chip = chip;
107         spin_unlock_irqrestore(&desc->lock, flags);
108
109         return 0;
110 }
111 EXPORT_SYMBOL(set_irq_chip);
112
113 /**
114  *      set_irq_type - set the irq trigger type for an irq
115  *      @irq:   irq number
116  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
117  */
118 int set_irq_type(unsigned int irq, unsigned int type)
119 {
120         struct irq_desc *desc = irq_to_desc(irq);
121         unsigned long flags;
122         int ret = -ENXIO;
123
124         if (!desc) {
125                 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
126                 return -ENODEV;
127         }
128
129         type &= IRQ_TYPE_SENSE_MASK;
130         if (type == IRQ_TYPE_NONE)
131                 return 0;
132
133         spin_lock_irqsave(&desc->lock, flags);
134         ret = __irq_set_trigger(desc, irq, type);
135         spin_unlock_irqrestore(&desc->lock, flags);
136         return ret;
137 }
138 EXPORT_SYMBOL(set_irq_type);
139
140 /**
141  *      set_irq_data - set irq type data for an irq
142  *      @irq:   Interrupt number
143  *      @data:  Pointer to interrupt specific data
144  *
145  *      Set the hardware irq controller data for an irq
146  */
147 int set_irq_data(unsigned int irq, void *data)
148 {
149         struct irq_desc *desc = irq_to_desc(irq);
150         unsigned long flags;
151
152         if (!desc) {
153                 printk(KERN_ERR
154                        "Trying to install controller data for IRQ%d\n", irq);
155                 return -EINVAL;
156         }
157
158         spin_lock_irqsave(&desc->lock, flags);
159         desc->handler_data = data;
160         spin_unlock_irqrestore(&desc->lock, flags);
161         return 0;
162 }
163 EXPORT_SYMBOL(set_irq_data);
164
165 /**
166  *      set_irq_data - set irq type data for an irq
167  *      @irq:   Interrupt number
168  *      @entry: Pointer to MSI descriptor data
169  *
170  *      Set the hardware irq controller data for an irq
171  */
172 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
173 {
174         struct irq_desc *desc = irq_to_desc(irq);
175         unsigned long flags;
176
177         if (!desc) {
178                 printk(KERN_ERR
179                        "Trying to install msi data for IRQ%d\n", irq);
180                 return -EINVAL;
181         }
182
183         spin_lock_irqsave(&desc->lock, flags);
184         desc->msi_desc = entry;
185         if (entry)
186                 entry->irq = irq;
187         spin_unlock_irqrestore(&desc->lock, flags);
188         return 0;
189 }
190
191 /**
192  *      set_irq_chip_data - set irq chip data for an irq
193  *      @irq:   Interrupt number
194  *      @data:  Pointer to chip specific data
195  *
196  *      Set the hardware irq chip data for an irq
197  */
198 int set_irq_chip_data(unsigned int irq, void *data)
199 {
200         struct irq_desc *desc = irq_to_desc(irq);
201         unsigned long flags;
202
203         if (!desc) {
204                 printk(KERN_ERR
205                        "Trying to install chip data for IRQ%d\n", irq);
206                 return -EINVAL;
207         }
208
209         if (!desc->chip) {
210                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
211                 return -EINVAL;
212         }
213
214         spin_lock_irqsave(&desc->lock, flags);
215         desc->chip_data = data;
216         spin_unlock_irqrestore(&desc->lock, flags);
217
218         return 0;
219 }
220 EXPORT_SYMBOL(set_irq_chip_data);
221
222 /*
223  * default enable function
224  */
225 static void default_enable(unsigned int irq)
226 {
227         struct irq_desc *desc = irq_to_desc(irq);
228
229         desc->chip->unmask(irq);
230         desc->status &= ~IRQ_MASKED;
231 }
232
233 /*
234  * default disable function
235  */
236 static void default_disable(unsigned int irq)
237 {
238 }
239
240 /*
241  * default startup function
242  */
243 static unsigned int default_startup(unsigned int irq)
244 {
245         struct irq_desc *desc = irq_to_desc(irq);
246
247         desc->chip->enable(irq);
248         return 0;
249 }
250
251 /*
252  * default shutdown function
253  */
254 static void default_shutdown(unsigned int irq)
255 {
256         struct irq_desc *desc = irq_to_desc(irq);
257
258         desc->chip->mask(irq);
259         desc->status |= IRQ_MASKED;
260 }
261
262 /*
263  * Fixup enable/disable function pointers
264  */
265 void irq_chip_set_defaults(struct irq_chip *chip)
266 {
267         if (!chip->enable)
268                 chip->enable = default_enable;
269         if (!chip->disable)
270                 chip->disable = default_disable;
271         if (!chip->startup)
272                 chip->startup = default_startup;
273         /*
274          * We use chip->disable, when the user provided its own. When
275          * we have default_disable set for chip->disable, then we need
276          * to use default_shutdown, otherwise the irq line is not
277          * disabled on free_irq():
278          */
279         if (!chip->shutdown)
280                 chip->shutdown = chip->disable != default_disable ?
281                         chip->disable : default_shutdown;
282         if (!chip->name)
283                 chip->name = chip->typename;
284         if (!chip->end)
285                 chip->end = dummy_irq_chip.end;
286 }
287
288 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
289 {
290         if (desc->chip->mask_ack)
291                 desc->chip->mask_ack(irq);
292         else {
293                 desc->chip->mask(irq);
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         desc->chip->ack(irq);
480         desc = irq_remap_to_desc(irq, desc);
481
482         /* Mark the IRQ currently in progress.*/
483         desc->status |= IRQ_INPROGRESS;
484
485         do {
486                 struct irqaction *action = desc->action;
487                 irqreturn_t action_ret;
488
489                 if (unlikely(!action)) {
490                         desc->chip->mask(irq);
491                         goto out_unlock;
492                 }
493
494                 /*
495                  * When another irq arrived while we were handling
496                  * one, we could have masked the irq.
497                  * Renable it, if it was not disabled in meantime.
498                  */
499                 if (unlikely((desc->status &
500                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
501                               (IRQ_PENDING | IRQ_MASKED))) {
502                         desc->chip->unmask(irq);
503                         desc->status &= ~IRQ_MASKED;
504                 }
505
506                 desc->status &= ~IRQ_PENDING;
507                 spin_unlock(&desc->lock);
508                 action_ret = handle_IRQ_event(irq, action);
509                 if (!noirqdebug)
510                         note_interrupt(irq, desc, action_ret);
511                 spin_lock(&desc->lock);
512
513         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
514
515         desc->status &= ~IRQ_INPROGRESS;
516 out_unlock:
517         spin_unlock(&desc->lock);
518 }
519
520 /**
521  *      handle_percpu_IRQ - Per CPU local irq handler
522  *      @irq:   the interrupt number
523  *      @desc:  the interrupt description structure for this irq
524  *
525  *      Per CPU interrupts on SMP machines without locking requirements
526  */
527 void
528 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
529 {
530         irqreturn_t action_ret;
531
532         kstat_incr_irqs_this_cpu(irq, desc);
533
534         if (desc->chip->ack)
535                 desc->chip->ack(irq);
536
537         action_ret = handle_IRQ_event(irq, desc->action);
538         if (!noirqdebug)
539                 note_interrupt(irq, desc, action_ret);
540
541         if (desc->chip->eoi) {
542                 desc->chip->eoi(irq);
543                 desc = irq_remap_to_desc(irq, desc);
544         }
545 }
546
547 void
548 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
549                   const char *name)
550 {
551         struct irq_desc *desc = irq_to_desc(irq);
552         unsigned long flags;
553
554         if (!desc) {
555                 printk(KERN_ERR
556                        "Trying to install type control for IRQ%d\n", irq);
557                 return;
558         }
559
560         if (!handle)
561                 handle = handle_bad_irq;
562         else if (desc->chip == &no_irq_chip) {
563                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
564                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
565                 /*
566                  * Some ARM implementations install a handler for really dumb
567                  * interrupt hardware without setting an irq_chip. This worked
568                  * with the ARM no_irq_chip but the check in setup_irq would
569                  * prevent us to setup the interrupt at all. Switch it to
570                  * dummy_irq_chip for easy transition.
571                  */
572                 desc->chip = &dummy_irq_chip;
573         }
574
575         spin_lock_irqsave(&desc->lock, flags);
576
577         /* Uninstall? */
578         if (handle == handle_bad_irq) {
579                 if (desc->chip != &no_irq_chip) {
580                         mask_ack_irq(desc, irq);
581                         desc = irq_remap_to_desc(irq, desc);
582                 }
583                 desc->status |= IRQ_DISABLED;
584                 desc->depth = 1;
585         }
586         desc->handle_irq = handle;
587         desc->name = name;
588
589         if (handle != handle_bad_irq && is_chained) {
590                 desc->status &= ~IRQ_DISABLED;
591                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
592                 desc->depth = 0;
593                 desc->chip->startup(irq);
594         }
595         spin_unlock_irqrestore(&desc->lock, flags);
596 }
597
598 void
599 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
600                          irq_flow_handler_t handle)
601 {
602         set_irq_chip(irq, chip);
603         __set_irq_handler(irq, handle, 0, NULL);
604 }
605
606 void
607 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
608                               irq_flow_handler_t handle, const char *name)
609 {
610         set_irq_chip(irq, chip);
611         __set_irq_handler(irq, handle, 0, name);
612 }
613
614 void __init set_irq_noprobe(unsigned int irq)
615 {
616         struct irq_desc *desc = irq_to_desc(irq);
617         unsigned long flags;
618
619         if (!desc) {
620                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
621                 return;
622         }
623
624         spin_lock_irqsave(&desc->lock, flags);
625         desc->status |= IRQ_NOPROBE;
626         spin_unlock_irqrestore(&desc->lock, flags);
627 }
628
629 void __init set_irq_probe(unsigned int irq)
630 {
631         struct irq_desc *desc = irq_to_desc(irq);
632         unsigned long flags;
633
634         if (!desc) {
635                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
636                 return;
637         }
638
639         spin_lock_irqsave(&desc->lock, flags);
640         desc->status &= ~IRQ_NOPROBE;
641         spin_unlock_irqrestore(&desc->lock, flags);
642 }