genirq: revert dynarray
[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(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         kstat_incr_irqs_this_cpu(irq, desc);
330
331         action = desc->action;
332         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
333                 goto out_unlock;
334
335         desc->status |= IRQ_INPROGRESS;
336         spin_unlock(&desc->lock);
337
338         action_ret = handle_IRQ_event(irq, action);
339         if (!noirqdebug)
340                 note_interrupt(irq, desc, action_ret);
341
342         spin_lock(&desc->lock);
343         desc->status &= ~IRQ_INPROGRESS;
344 out_unlock:
345         spin_unlock(&desc->lock);
346 }
347
348 /**
349  *      handle_level_irq - Level type irq handler
350  *      @irq:   the interrupt number
351  *      @desc:  the interrupt description structure for this irq
352  *
353  *      Level type interrupts are active as long as the hardware line has
354  *      the active level. This may require to mask the interrupt and unmask
355  *      it after the associated handler has acknowledged the device, so the
356  *      interrupt line is back to inactive.
357  */
358 void
359 handle_level_irq(unsigned int irq, struct irq_desc *desc)
360 {
361         struct irqaction *action;
362         irqreturn_t action_ret;
363
364         spin_lock(&desc->lock);
365         mask_ack_irq(desc, irq);
366
367         if (unlikely(desc->status & IRQ_INPROGRESS))
368                 goto out_unlock;
369         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
370         kstat_incr_irqs_this_cpu(irq, desc);
371
372         /*
373          * If its disabled or no action available
374          * keep it masked and get out of here
375          */
376         action = desc->action;
377         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
378                 goto out_unlock;
379
380         desc->status |= IRQ_INPROGRESS;
381         spin_unlock(&desc->lock);
382
383         action_ret = handle_IRQ_event(irq, action);
384         if (!noirqdebug)
385                 note_interrupt(irq, desc, action_ret);
386
387         spin_lock(&desc->lock);
388         desc->status &= ~IRQ_INPROGRESS;
389         if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
390                 desc->chip->unmask(irq);
391 out_unlock:
392         spin_unlock(&desc->lock);
393 }
394
395 /**
396  *      handle_fasteoi_irq - irq handler for transparent controllers
397  *      @irq:   the interrupt number
398  *      @desc:  the interrupt description structure for this irq
399  *
400  *      Only a single callback will be issued to the chip: an ->eoi()
401  *      call when the interrupt has been serviced. This enables support
402  *      for modern forms of interrupt handlers, which handle the flow
403  *      details in hardware, transparently.
404  */
405 void
406 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
407 {
408         struct irqaction *action;
409         irqreturn_t action_ret;
410
411         spin_lock(&desc->lock);
412
413         if (unlikely(desc->status & IRQ_INPROGRESS))
414                 goto out;
415
416         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
417         kstat_incr_irqs_this_cpu(irq, desc);
418
419         /*
420          * If its disabled or no action available
421          * then mask it and get out of here:
422          */
423         action = desc->action;
424         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
425                 desc->status |= IRQ_PENDING;
426                 if (desc->chip->mask)
427                         desc->chip->mask(irq);
428                 goto out;
429         }
430
431         desc->status |= IRQ_INPROGRESS;
432         desc->status &= ~IRQ_PENDING;
433         spin_unlock(&desc->lock);
434
435         action_ret = handle_IRQ_event(irq, action);
436         if (!noirqdebug)
437                 note_interrupt(irq, desc, action_ret);
438
439         spin_lock(&desc->lock);
440         desc->status &= ~IRQ_INPROGRESS;
441 out:
442         desc->chip->eoi(irq);
443
444         spin_unlock(&desc->lock);
445 }
446
447 /**
448  *      handle_edge_irq - edge type IRQ handler
449  *      @irq:   the interrupt number
450  *      @desc:  the interrupt description structure for this irq
451  *
452  *      Interrupt occures on the falling and/or rising edge of a hardware
453  *      signal. The occurence is latched into the irq controller hardware
454  *      and must be acked in order to be reenabled. After the ack another
455  *      interrupt can happen on the same source even before the first one
456  *      is handled by the assosiacted event handler. If this happens it
457  *      might be necessary to disable (mask) the interrupt depending on the
458  *      controller hardware. This requires to reenable the interrupt inside
459  *      of the loop which handles the interrupts which have arrived while
460  *      the handler was running. If all pending interrupts are handled, the
461  *      loop is left.
462  */
463 void
464 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
465 {
466         spin_lock(&desc->lock);
467
468         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
469
470         /*
471          * If we're currently running this IRQ, or its disabled,
472          * we shouldn't process the IRQ. Mark it pending, handle
473          * the necessary masking and go out
474          */
475         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
476                     !desc->action)) {
477                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
478                 mask_ack_irq(desc, irq);
479                 goto out_unlock;
480         }
481         kstat_incr_irqs_this_cpu(irq, desc);
482
483         /* Start handling the irq */
484         desc->chip->ack(irq);
485
486         /* Mark the IRQ currently in progress.*/
487         desc->status |= IRQ_INPROGRESS;
488
489         do {
490                 struct irqaction *action = desc->action;
491                 irqreturn_t action_ret;
492
493                 if (unlikely(!action)) {
494                         desc->chip->mask(irq);
495                         goto out_unlock;
496                 }
497
498                 /*
499                  * When another irq arrived while we were handling
500                  * one, we could have masked the irq.
501                  * Renable it, if it was not disabled in meantime.
502                  */
503                 if (unlikely((desc->status &
504                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
505                               (IRQ_PENDING | IRQ_MASKED))) {
506                         desc->chip->unmask(irq);
507                         desc->status &= ~IRQ_MASKED;
508                 }
509
510                 desc->status &= ~IRQ_PENDING;
511                 spin_unlock(&desc->lock);
512                 action_ret = handle_IRQ_event(irq, action);
513                 if (!noirqdebug)
514                         note_interrupt(irq, desc, action_ret);
515                 spin_lock(&desc->lock);
516
517         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
518
519         desc->status &= ~IRQ_INPROGRESS;
520 out_unlock:
521         spin_unlock(&desc->lock);
522 }
523
524 /**
525  *      handle_percpu_IRQ - Per CPU local irq handler
526  *      @irq:   the interrupt number
527  *      @desc:  the interrupt description structure for this irq
528  *
529  *      Per CPU interrupts on SMP machines without locking requirements
530  */
531 void
532 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
533 {
534         irqreturn_t action_ret;
535
536         kstat_incr_irqs_this_cpu(irq, desc);
537
538         if (desc->chip->ack)
539                 desc->chip->ack(irq);
540
541         action_ret = handle_IRQ_event(irq, desc->action);
542         if (!noirqdebug)
543                 note_interrupt(irq, desc, action_ret);
544
545         if (desc->chip->eoi)
546                 desc->chip->eoi(irq);
547 }
548
549 void
550 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
551                   const char *name)
552 {
553         struct irq_desc *desc;
554         unsigned long flags;
555
556         desc = irq_to_desc(irq);
557         if (!desc) {
558                 printk(KERN_ERR
559                        "Trying to install type control for IRQ%d\n", irq);
560                 return;
561         }
562
563         if (!handle)
564                 handle = handle_bad_irq;
565         else if (desc->chip == &no_irq_chip) {
566                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
567                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
568                 /*
569                  * Some ARM implementations install a handler for really dumb
570                  * interrupt hardware without setting an irq_chip. This worked
571                  * with the ARM no_irq_chip but the check in setup_irq would
572                  * prevent us to setup the interrupt at all. Switch it to
573                  * dummy_irq_chip for easy transition.
574                  */
575                 desc->chip = &dummy_irq_chip;
576         }
577
578         spin_lock_irqsave(&desc->lock, flags);
579
580         /* Uninstall? */
581         if (handle == handle_bad_irq) {
582                 if (desc->chip != &no_irq_chip)
583                         mask_ack_irq(desc, irq);
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;
618         unsigned long flags;
619
620         desc = irq_to_desc(irq);
621         if (!desc) {
622                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
623
624                 return;
625         }
626
627         spin_lock_irqsave(&desc->lock, flags);
628         desc->status |= IRQ_NOPROBE;
629         spin_unlock_irqrestore(&desc->lock, flags);
630 }
631
632 void __init set_irq_probe(unsigned int irq)
633 {
634         struct irq_desc *desc;
635         unsigned long flags;
636
637         desc = irq_to_desc(irq);
638         if (!desc) {
639                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
640
641                 return;
642         }
643
644         spin_lock_irqsave(&desc->lock, flags);
645         desc->status &= ~IRQ_NOPROBE;
646         spin_unlock_irqrestore(&desc->lock, flags);
647 }