2 * linux/kernel/irq/chip.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
7 * This file contains the core interrupt handling code, for irq-chip
10 * Detailed information is available in Documentation/DocBook/genericirq
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>
19 #include "internals.h"
22 * dynamic_irq_init - initialize a dynamically allocated irq
23 * @irq: irq number to initialize
25 void dynamic_irq_init(unsigned int irq
)
27 struct irq_desc
*desc
;
30 desc
= irq_to_desc(irq
);
32 WARN(1, KERN_ERR
"Trying to initialize invalid IRQ%d\n", irq
);
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
;
42 desc
->msi_desc
= NULL
;
43 desc
->handler_data
= NULL
;
44 desc
->chip_data
= NULL
;
47 desc
->irqs_unhandled
= 0;
49 cpumask_setall(desc
->affinity
);
50 #ifdef CONFIG_GENERIC_PENDING_IRQ
51 cpumask_clear(desc
->pending_mask
);
54 spin_unlock_irqrestore(&desc
->lock
, flags
);
58 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
59 * @irq: irq number to initialize
61 void dynamic_irq_cleanup(unsigned int irq
)
63 struct irq_desc
*desc
= irq_to_desc(irq
);
67 WARN(1, KERN_ERR
"Trying to cleanup invalid IRQ%d\n", irq
);
71 spin_lock_irqsave(&desc
->lock
, flags
);
73 spin_unlock_irqrestore(&desc
->lock
, flags
);
74 WARN(1, KERN_ERR
"Destroying IRQ%d without calling free_irq\n",
78 desc
->msi_desc
= NULL
;
79 desc
->handler_data
= NULL
;
80 desc
->chip_data
= NULL
;
81 desc
->handle_irq
= handle_bad_irq
;
82 desc
->chip
= &no_irq_chip
;
84 clear_kstat_irqs(desc
);
85 spin_unlock_irqrestore(&desc
->lock
, flags
);
90 * set_irq_chip - set the irq chip for an irq
92 * @chip: pointer to irq chip description structure
94 int set_irq_chip(unsigned int irq
, struct irq_chip
*chip
)
96 struct irq_desc
*desc
= irq_to_desc(irq
);
100 WARN(1, KERN_ERR
"Trying to install chip for IRQ%d\n", irq
);
107 spin_lock_irqsave(&desc
->lock
, flags
);
108 irq_chip_set_defaults(chip
);
110 spin_unlock_irqrestore(&desc
->lock
, flags
);
114 EXPORT_SYMBOL(set_irq_chip
);
117 * set_irq_type - set the irq trigger type for an irq
119 * @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
121 int set_irq_type(unsigned int irq
, unsigned int type
)
123 struct irq_desc
*desc
= irq_to_desc(irq
);
128 printk(KERN_ERR
"Trying to set irq type for IRQ%d\n", irq
);
132 type
&= IRQ_TYPE_SENSE_MASK
;
133 if (type
== IRQ_TYPE_NONE
)
136 spin_lock_irqsave(&desc
->lock
, flags
);
137 ret
= __irq_set_trigger(desc
, irq
, type
);
138 spin_unlock_irqrestore(&desc
->lock
, flags
);
141 EXPORT_SYMBOL(set_irq_type
);
144 * set_irq_data - set irq type data for an irq
145 * @irq: Interrupt number
146 * @data: Pointer to interrupt specific data
148 * Set the hardware irq controller data for an irq
150 int set_irq_data(unsigned int irq
, void *data
)
152 struct irq_desc
*desc
= irq_to_desc(irq
);
157 "Trying to install controller data for IRQ%d\n", irq
);
161 spin_lock_irqsave(&desc
->lock
, flags
);
162 desc
->handler_data
= data
;
163 spin_unlock_irqrestore(&desc
->lock
, flags
);
166 EXPORT_SYMBOL(set_irq_data
);
169 * set_irq_data - set irq type data for an irq
170 * @irq: Interrupt number
171 * @entry: Pointer to MSI descriptor data
173 * Set the hardware irq controller data for an irq
175 int set_irq_msi(unsigned int irq
, struct msi_desc
*entry
)
177 struct irq_desc
*desc
= irq_to_desc(irq
);
182 "Trying to install msi data for IRQ%d\n", irq
);
186 spin_lock_irqsave(&desc
->lock
, flags
);
187 desc
->msi_desc
= entry
;
190 spin_unlock_irqrestore(&desc
->lock
, flags
);
195 * set_irq_chip_data - set irq chip data for an irq
196 * @irq: Interrupt number
197 * @data: Pointer to chip specific data
199 * Set the hardware irq chip data for an irq
201 int set_irq_chip_data(unsigned int irq
, void *data
)
203 struct irq_desc
*desc
= irq_to_desc(irq
);
208 "Trying to install chip data for IRQ%d\n", irq
);
213 printk(KERN_ERR
"BUG: bad set_irq_chip_data(IRQ#%d)\n", irq
);
217 spin_lock_irqsave(&desc
->lock
, flags
);
218 desc
->chip_data
= data
;
219 spin_unlock_irqrestore(&desc
->lock
, flags
);
223 EXPORT_SYMBOL(set_irq_chip_data
);
226 * set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
228 * @irq: Interrupt number
229 * @nest: 0 to clear / 1 to set the IRQ_NESTED_THREAD flag
231 * The IRQ_NESTED_THREAD flag indicates that on
232 * request_threaded_irq() no separate interrupt thread should be
233 * created for the irq as the handler are called nested in the
234 * context of a demultiplexing interrupt handler thread.
236 void set_irq_nested_thread(unsigned int irq
, int nest
)
238 struct irq_desc
*desc
= irq_to_desc(irq
);
244 spin_lock_irqsave(&desc
->lock
, flags
);
246 desc
->status
|= IRQ_NESTED_THREAD
;
248 desc
->status
&= ~IRQ_NESTED_THREAD
;
249 spin_unlock_irqrestore(&desc
->lock
, flags
);
251 EXPORT_SYMBOL_GPL(set_irq_nested_thread
);
254 * default enable function
256 static void default_enable(unsigned int irq
)
258 struct irq_desc
*desc
= irq_to_desc(irq
);
260 desc
->chip
->unmask(irq
);
261 desc
->status
&= ~IRQ_MASKED
;
265 * default disable function
267 static void default_disable(unsigned int irq
)
272 * default startup function
274 static unsigned int default_startup(unsigned int irq
)
276 struct irq_desc
*desc
= irq_to_desc(irq
);
278 desc
->chip
->enable(irq
);
283 * default shutdown function
285 static void default_shutdown(unsigned int irq
)
287 struct irq_desc
*desc
= irq_to_desc(irq
);
289 desc
->chip
->mask(irq
);
290 desc
->status
|= IRQ_MASKED
;
294 * Fixup enable/disable function pointers
296 void irq_chip_set_defaults(struct irq_chip
*chip
)
299 chip
->enable
= default_enable
;
301 chip
->disable
= default_disable
;
303 chip
->startup
= default_startup
;
305 * We use chip->disable, when the user provided its own. When
306 * we have default_disable set for chip->disable, then we need
307 * to use default_shutdown, otherwise the irq line is not
308 * disabled on free_irq():
311 chip
->shutdown
= chip
->disable
!= default_disable
?
312 chip
->disable
: default_shutdown
;
314 chip
->name
= chip
->typename
;
316 chip
->end
= dummy_irq_chip
.end
;
319 static inline void mask_ack_irq(struct irq_desc
*desc
, int irq
)
321 if (desc
->chip
->mask_ack
)
322 desc
->chip
->mask_ack(irq
);
324 desc
->chip
->mask(irq
);
326 desc
->chip
->ack(irq
);
331 * handle_nested_irq - Handle a nested irq from a irq thread
332 * @irq: the interrupt number
334 * Handle interrupts which are nested into a threaded interrupt
335 * handler. The handler function is called inside the calling
338 void handle_nested_irq(unsigned int irq
)
340 struct irq_desc
*desc
= irq_to_desc(irq
);
341 struct irqaction
*action
;
342 irqreturn_t action_ret
;
346 spin_lock_irq(&desc
->lock
);
348 kstat_incr_irqs_this_cpu(irq
, desc
);
350 action
= desc
->action
;
351 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
)))
354 desc
->status
|= IRQ_INPROGRESS
;
355 spin_unlock_irq(&desc
->lock
);
357 action_ret
= action
->thread_fn(action
->irq
, action
->dev_id
);
359 note_interrupt(irq
, desc
, action_ret
);
361 spin_lock_irq(&desc
->lock
);
362 desc
->status
&= ~IRQ_INPROGRESS
;
365 spin_unlock_irq(&desc
->lock
);
367 EXPORT_SYMBOL_GPL(handle_nested_irq
);
370 * handle_simple_irq - Simple and software-decoded IRQs.
371 * @irq: the interrupt number
372 * @desc: the interrupt description structure for this irq
374 * Simple interrupts are either sent from a demultiplexing interrupt
375 * handler or come from hardware, where no interrupt hardware control
378 * Note: The caller is expected to handle the ack, clear, mask and
379 * unmask issues if necessary.
382 handle_simple_irq(unsigned int irq
, struct irq_desc
*desc
)
384 struct irqaction
*action
;
385 irqreturn_t action_ret
;
387 spin_lock(&desc
->lock
);
389 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
391 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
392 kstat_incr_irqs_this_cpu(irq
, desc
);
394 action
= desc
->action
;
395 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
)))
398 desc
->status
|= IRQ_INPROGRESS
;
399 spin_unlock(&desc
->lock
);
401 action_ret
= handle_IRQ_event(irq
, action
);
403 note_interrupt(irq
, desc
, action_ret
);
405 spin_lock(&desc
->lock
);
406 desc
->status
&= ~IRQ_INPROGRESS
;
408 spin_unlock(&desc
->lock
);
412 * handle_level_irq - Level type irq handler
413 * @irq: the interrupt number
414 * @desc: the interrupt description structure for this irq
416 * Level type interrupts are active as long as the hardware line has
417 * the active level. This may require to mask the interrupt and unmask
418 * it after the associated handler has acknowledged the device, so the
419 * interrupt line is back to inactive.
422 handle_level_irq(unsigned int irq
, struct irq_desc
*desc
)
424 struct irqaction
*action
;
425 irqreturn_t action_ret
;
427 spin_lock(&desc
->lock
);
428 mask_ack_irq(desc
, irq
);
430 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
432 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
433 kstat_incr_irqs_this_cpu(irq
, desc
);
436 * If its disabled or no action available
437 * keep it masked and get out of here
439 action
= desc
->action
;
440 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
)))
443 desc
->status
|= IRQ_INPROGRESS
;
444 spin_unlock(&desc
->lock
);
446 action_ret
= handle_IRQ_event(irq
, action
);
448 note_interrupt(irq
, desc
, action_ret
);
450 spin_lock(&desc
->lock
);
451 desc
->status
&= ~IRQ_INPROGRESS
;
453 if (unlikely(desc
->status
& IRQ_ONESHOT
))
454 desc
->status
|= IRQ_MASKED
;
455 else if (!(desc
->status
& IRQ_DISABLED
) && desc
->chip
->unmask
)
456 desc
->chip
->unmask(irq
);
458 spin_unlock(&desc
->lock
);
460 EXPORT_SYMBOL_GPL(handle_level_irq
);
463 * handle_fasteoi_irq - irq handler for transparent controllers
464 * @irq: the interrupt number
465 * @desc: the interrupt description structure for this irq
467 * Only a single callback will be issued to the chip: an ->eoi()
468 * call when the interrupt has been serviced. This enables support
469 * for modern forms of interrupt handlers, which handle the flow
470 * details in hardware, transparently.
473 handle_fasteoi_irq(unsigned int irq
, struct irq_desc
*desc
)
475 struct irqaction
*action
;
476 irqreturn_t action_ret
;
478 spin_lock(&desc
->lock
);
480 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
483 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
484 kstat_incr_irqs_this_cpu(irq
, desc
);
487 * If its disabled or no action available
488 * then mask it and get out of here:
490 action
= desc
->action
;
491 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
))) {
492 desc
->status
|= IRQ_PENDING
;
493 if (desc
->chip
->mask
)
494 desc
->chip
->mask(irq
);
498 desc
->status
|= IRQ_INPROGRESS
;
499 desc
->status
&= ~IRQ_PENDING
;
500 spin_unlock(&desc
->lock
);
502 action_ret
= handle_IRQ_event(irq
, action
);
504 note_interrupt(irq
, desc
, action_ret
);
506 spin_lock(&desc
->lock
);
507 desc
->status
&= ~IRQ_INPROGRESS
;
509 desc
->chip
->eoi(irq
);
511 spin_unlock(&desc
->lock
);
515 * handle_edge_irq - edge type IRQ handler
516 * @irq: the interrupt number
517 * @desc: the interrupt description structure for this irq
519 * Interrupt occures on the falling and/or rising edge of a hardware
520 * signal. The occurence is latched into the irq controller hardware
521 * and must be acked in order to be reenabled. After the ack another
522 * interrupt can happen on the same source even before the first one
523 * is handled by the assosiacted event handler. If this happens it
524 * might be necessary to disable (mask) the interrupt depending on the
525 * controller hardware. This requires to reenable the interrupt inside
526 * of the loop which handles the interrupts which have arrived while
527 * the handler was running. If all pending interrupts are handled, the
531 handle_edge_irq(unsigned int irq
, struct irq_desc
*desc
)
533 spin_lock(&desc
->lock
);
535 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
538 * If we're currently running this IRQ, or its disabled,
539 * we shouldn't process the IRQ. Mark it pending, handle
540 * the necessary masking and go out
542 if (unlikely((desc
->status
& (IRQ_INPROGRESS
| IRQ_DISABLED
)) ||
544 desc
->status
|= (IRQ_PENDING
| IRQ_MASKED
);
545 mask_ack_irq(desc
, irq
);
548 kstat_incr_irqs_this_cpu(irq
, desc
);
550 /* Start handling the irq */
551 if (unlikely(desc
->status
& IRQ_ONESHOT
)) {
552 desc
->status
|= IRQ_MASKED
;
553 mask_ack_irq(desc
, irq
);
556 desc
->chip
->ack(irq
);
559 /* Mark the IRQ currently in progress.*/
560 desc
->status
|= IRQ_INPROGRESS
;
563 struct irqaction
*action
= desc
->action
;
564 irqreturn_t action_ret
;
566 if (unlikely(!action
)) {
567 desc
->chip
->mask(irq
);
572 * When another irq arrived while we were handling
573 * one, we could have masked the irq.
574 * Renable it, if it was not disabled in meantime.
576 if (unlikely((desc
->status
&
577 (IRQ_PENDING
| IRQ_MASKED
| IRQ_DISABLED
)) ==
578 (IRQ_PENDING
| IRQ_MASKED
))) {
579 desc
->chip
->unmask(irq
);
580 desc
->status
&= ~IRQ_MASKED
;
583 desc
->status
&= ~IRQ_PENDING
;
584 spin_unlock(&desc
->lock
);
585 action_ret
= handle_IRQ_event(irq
, action
);
587 note_interrupt(irq
, desc
, action_ret
);
588 spin_lock(&desc
->lock
);
590 } while ((desc
->status
& (IRQ_PENDING
| IRQ_DISABLED
)) == IRQ_PENDING
);
592 desc
->status
&= ~IRQ_INPROGRESS
;
594 spin_unlock(&desc
->lock
);
598 * handle_percpu_IRQ - Per CPU local irq handler
599 * @irq: the interrupt number
600 * @desc: the interrupt description structure for this irq
602 * Per CPU interrupts on SMP machines without locking requirements
605 handle_percpu_irq(unsigned int irq
, struct irq_desc
*desc
)
607 irqreturn_t action_ret
;
609 kstat_incr_irqs_this_cpu(irq
, desc
);
612 desc
->chip
->ack(irq
);
614 action_ret
= handle_IRQ_event(irq
, desc
->action
);
616 note_interrupt(irq
, desc
, action_ret
);
619 desc
->chip
->eoi(irq
);
623 __set_irq_handler(unsigned int irq
, irq_flow_handler_t handle
, int is_chained
,
626 struct irq_desc
*desc
= irq_to_desc(irq
);
631 "Trying to install type control for IRQ%d\n", irq
);
636 handle
= handle_bad_irq
;
637 else if (desc
->chip
== &no_irq_chip
) {
638 printk(KERN_WARNING
"Trying to install %sinterrupt handler "
639 "for IRQ%d\n", is_chained
? "chained " : "", irq
);
641 * Some ARM implementations install a handler for really dumb
642 * interrupt hardware without setting an irq_chip. This worked
643 * with the ARM no_irq_chip but the check in setup_irq would
644 * prevent us to setup the interrupt at all. Switch it to
645 * dummy_irq_chip for easy transition.
647 desc
->chip
= &dummy_irq_chip
;
650 chip_bus_lock(irq
, desc
);
651 spin_lock_irqsave(&desc
->lock
, flags
);
654 if (handle
== handle_bad_irq
) {
655 if (desc
->chip
!= &no_irq_chip
)
656 mask_ack_irq(desc
, irq
);
657 desc
->status
|= IRQ_DISABLED
;
660 desc
->handle_irq
= handle
;
663 if (handle
!= handle_bad_irq
&& is_chained
) {
664 desc
->status
&= ~IRQ_DISABLED
;
665 desc
->status
|= IRQ_NOREQUEST
| IRQ_NOPROBE
;
667 desc
->chip
->startup(irq
);
669 spin_unlock_irqrestore(&desc
->lock
, flags
);
670 chip_bus_sync_unlock(irq
, desc
);
672 EXPORT_SYMBOL_GPL(__set_irq_handler
);
675 set_irq_chip_and_handler(unsigned int irq
, struct irq_chip
*chip
,
676 irq_flow_handler_t handle
)
678 set_irq_chip(irq
, chip
);
679 __set_irq_handler(irq
, handle
, 0, NULL
);
683 set_irq_chip_and_handler_name(unsigned int irq
, struct irq_chip
*chip
,
684 irq_flow_handler_t handle
, const char *name
)
686 set_irq_chip(irq
, chip
);
687 __set_irq_handler(irq
, handle
, 0, name
);
690 void __init
set_irq_noprobe(unsigned int irq
)
692 struct irq_desc
*desc
= irq_to_desc(irq
);
696 printk(KERN_ERR
"Trying to mark IRQ%d non-probeable\n", irq
);
700 spin_lock_irqsave(&desc
->lock
, flags
);
701 desc
->status
|= IRQ_NOPROBE
;
702 spin_unlock_irqrestore(&desc
->lock
, flags
);
705 void __init
set_irq_probe(unsigned int irq
)
707 struct irq_desc
*desc
= irq_to_desc(irq
);
711 printk(KERN_ERR
"Trying to mark IRQ%d probeable\n", irq
);
715 spin_lock_irqsave(&desc
->lock
, flags
);
716 desc
->status
&= ~IRQ_NOPROBE
;
717 spin_unlock_irqrestore(&desc
->lock
, flags
);