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
;
31 WARN(1, KERN_ERR
"Trying to initialize invalid IRQ%d\n", irq
);
35 /* Ensure we don't have left over values from a previous use of this irq */
36 desc
= irq_to_desc(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 cpus_setall(desc
->affinity
);
51 spin_unlock_irqrestore(&desc
->lock
, flags
);
55 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
56 * @irq: irq number to initialize
58 void dynamic_irq_cleanup(unsigned int irq
)
60 struct irq_desc
*desc
;
64 WARN(1, KERN_ERR
"Trying to cleanup invalid IRQ%d\n", irq
);
68 desc
= irq_to_desc(irq
);
69 spin_lock_irqsave(&desc
->lock
, flags
);
71 spin_unlock_irqrestore(&desc
->lock
, flags
);
72 WARN(1, KERN_ERR
"Destroying IRQ%d without calling free_irq\n",
76 desc
->msi_desc
= NULL
;
77 desc
->handler_data
= NULL
;
78 desc
->chip_data
= NULL
;
79 desc
->handle_irq
= handle_bad_irq
;
80 desc
->chip
= &no_irq_chip
;
81 spin_unlock_irqrestore(&desc
->lock
, flags
);
86 * set_irq_chip - set the irq chip for an irq
88 * @chip: pointer to irq chip description structure
90 int set_irq_chip(unsigned int irq
, struct irq_chip
*chip
)
92 struct irq_desc
*desc
;
96 WARN(1, KERN_ERR
"Trying to install chip for IRQ%d\n", irq
);
103 desc
= irq_to_desc(irq
);
104 spin_lock_irqsave(&desc
->lock
, flags
);
105 irq_chip_set_defaults(chip
);
107 spin_unlock_irqrestore(&desc
->lock
, flags
);
111 EXPORT_SYMBOL(set_irq_chip
);
114 * set_irq_type - set the irq trigger type for an irq
116 * @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
118 int set_irq_type(unsigned int irq
, unsigned int type
)
120 struct irq_desc
*desc
;
124 if (irq
>= nr_irqs
) {
125 printk(KERN_ERR
"Trying to set irq type for IRQ%d\n", irq
);
129 desc
= irq_to_desc(irq
);
130 if (type
== IRQ_TYPE_NONE
)
133 spin_lock_irqsave(&desc
->lock
, flags
);
134 ret
= __irq_set_trigger(desc
, irq
, flags
);
135 spin_unlock_irqrestore(&desc
->lock
, flags
);
138 EXPORT_SYMBOL(set_irq_type
);
141 * set_irq_data - set irq type data for an irq
142 * @irq: Interrupt number
143 * @data: Pointer to interrupt specific data
145 * Set the hardware irq controller data for an irq
147 int set_irq_data(unsigned int irq
, void *data
)
149 struct irq_desc
*desc
;
152 if (irq
>= nr_irqs
) {
154 "Trying to install controller data for IRQ%d\n", irq
);
158 desc
= irq_to_desc(irq
);
159 spin_lock_irqsave(&desc
->lock
, flags
);
160 desc
->handler_data
= data
;
161 spin_unlock_irqrestore(&desc
->lock
, flags
);
164 EXPORT_SYMBOL(set_irq_data
);
167 * set_irq_data - set irq type data for an irq
168 * @irq: Interrupt number
169 * @entry: Pointer to MSI descriptor data
171 * Set the hardware irq controller data for an irq
173 int set_irq_msi(unsigned int irq
, struct msi_desc
*entry
)
175 struct irq_desc
*desc
;
178 if (irq
>= nr_irqs
) {
180 "Trying to install msi data for IRQ%d\n", irq
);
183 desc
= irq_to_desc(irq
);
184 spin_lock_irqsave(&desc
->lock
, flags
);
185 desc
->msi_desc
= entry
;
188 spin_unlock_irqrestore(&desc
->lock
, flags
);
193 * set_irq_chip_data - set irq chip data for an irq
194 * @irq: Interrupt number
195 * @data: Pointer to chip specific data
197 * Set the hardware irq chip data for an irq
199 int set_irq_chip_data(unsigned int irq
, void *data
)
201 struct irq_desc
*desc
;
204 desc
= irq_to_desc(irq
);
205 if (irq
>= nr_irqs
|| !desc
->chip
) {
206 printk(KERN_ERR
"BUG: bad set_irq_chip_data(IRQ#%d)\n", irq
);
210 spin_lock_irqsave(&desc
->lock
, flags
);
211 desc
->chip_data
= data
;
212 spin_unlock_irqrestore(&desc
->lock
, flags
);
216 EXPORT_SYMBOL(set_irq_chip_data
);
219 * default enable function
221 static void default_enable(unsigned int irq
)
223 struct irq_desc
*desc
;
225 desc
= irq_to_desc(irq
);
226 desc
->chip
->unmask(irq
);
227 desc
->status
&= ~IRQ_MASKED
;
231 * default disable function
233 static void default_disable(unsigned int irq
)
238 * default startup function
240 static unsigned int default_startup(unsigned int irq
)
242 struct irq_desc
*desc
;
244 desc
= irq_to_desc(irq
);
245 desc
->chip
->enable(irq
);
251 * default shutdown function
253 static void default_shutdown(unsigned int irq
)
255 struct irq_desc
*desc
;
257 desc
= irq_to_desc(irq
);
258 desc
->chip
->mask(irq
);
259 desc
->status
|= IRQ_MASKED
;
263 * Fixup enable/disable function pointers
265 void irq_chip_set_defaults(struct irq_chip
*chip
)
268 chip
->enable
= default_enable
;
270 chip
->disable
= default_disable
;
272 chip
->startup
= default_startup
;
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():
280 chip
->shutdown
= chip
->disable
!= default_disable
?
281 chip
->disable
: default_shutdown
;
283 chip
->name
= chip
->typename
;
285 chip
->end
= dummy_irq_chip
.end
;
288 static inline void mask_ack_irq(struct irq_desc
*desc
, int irq
)
290 if (desc
->chip
->mask_ack
)
291 desc
->chip
->mask_ack(irq
);
293 desc
->chip
->mask(irq
);
294 desc
->chip
->ack(irq
);
299 * handle_simple_irq - Simple and software-decoded IRQs.
300 * @irq: the interrupt number
301 * @desc: the interrupt description structure for this irq
303 * Simple interrupts are either sent from a demultiplexing interrupt
304 * handler or come from hardware, where no interrupt hardware control
307 * Note: The caller is expected to handle the ack, clear, mask and
308 * unmask issues if necessary.
311 handle_simple_irq(unsigned int irq
, struct irq_desc
*desc
)
313 struct irqaction
*action
;
314 irqreturn_t action_ret
;
316 spin_lock(&desc
->lock
);
318 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
320 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
321 kstat_irqs_this_cpu(desc
)++;
323 action
= desc
->action
;
324 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
)))
327 desc
->status
|= IRQ_INPROGRESS
;
328 spin_unlock(&desc
->lock
);
330 action_ret
= handle_IRQ_event(irq
, action
);
332 note_interrupt(irq
, desc
, action_ret
);
334 spin_lock(&desc
->lock
);
335 desc
->status
&= ~IRQ_INPROGRESS
;
337 spin_unlock(&desc
->lock
);
341 * handle_level_irq - Level type irq handler
342 * @irq: the interrupt number
343 * @desc: the interrupt description structure for this irq
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.
351 handle_level_irq(unsigned int irq
, struct irq_desc
*desc
)
353 struct irqaction
*action
;
354 irqreturn_t action_ret
;
356 spin_lock(&desc
->lock
);
357 mask_ack_irq(desc
, irq
);
359 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
361 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
362 kstat_irqs_this_cpu(desc
)++;
365 * If its disabled or no action available
366 * keep it masked and get out of here
368 action
= desc
->action
;
369 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
)))
372 desc
->status
|= IRQ_INPROGRESS
;
373 spin_unlock(&desc
->lock
);
375 action_ret
= handle_IRQ_event(irq
, action
);
377 note_interrupt(irq
, desc
, action_ret
);
379 spin_lock(&desc
->lock
);
380 desc
->status
&= ~IRQ_INPROGRESS
;
381 if (!(desc
->status
& IRQ_DISABLED
) && desc
->chip
->unmask
)
382 desc
->chip
->unmask(irq
);
384 spin_unlock(&desc
->lock
);
388 * handle_fasteoi_irq - irq handler for transparent controllers
389 * @irq: the interrupt number
390 * @desc: the interrupt description structure for this irq
392 * Only a single callback will be issued to the chip: an ->eoi()
393 * call when the interrupt has been serviced. This enables support
394 * for modern forms of interrupt handlers, which handle the flow
395 * details in hardware, transparently.
398 handle_fasteoi_irq(unsigned int irq
, struct irq_desc
*desc
)
400 struct irqaction
*action
;
401 irqreturn_t action_ret
;
403 spin_lock(&desc
->lock
);
405 if (unlikely(desc
->status
& IRQ_INPROGRESS
))
408 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
409 kstat_irqs_this_cpu(desc
)++;
412 * If its disabled or no action available
413 * then mask it and get out of here:
415 action
= desc
->action
;
416 if (unlikely(!action
|| (desc
->status
& IRQ_DISABLED
))) {
417 desc
->status
|= IRQ_PENDING
;
418 if (desc
->chip
->mask
)
419 desc
->chip
->mask(irq
);
423 desc
->status
|= IRQ_INPROGRESS
;
424 desc
->status
&= ~IRQ_PENDING
;
425 spin_unlock(&desc
->lock
);
427 action_ret
= handle_IRQ_event(irq
, action
);
429 note_interrupt(irq
, desc
, action_ret
);
431 spin_lock(&desc
->lock
);
432 desc
->status
&= ~IRQ_INPROGRESS
;
434 desc
->chip
->eoi(irq
);
436 spin_unlock(&desc
->lock
);
440 * handle_edge_irq - edge type IRQ handler
441 * @irq: the interrupt number
442 * @desc: the interrupt description structure for this irq
444 * Interrupt occures on the falling and/or rising edge of a hardware
445 * signal. The occurence is latched into the irq controller hardware
446 * and must be acked in order to be reenabled. After the ack another
447 * interrupt can happen on the same source even before the first one
448 * is handled by the assosiacted event handler. If this happens it
449 * might be necessary to disable (mask) the interrupt depending on the
450 * controller hardware. This requires to reenable the interrupt inside
451 * of the loop which handles the interrupts which have arrived while
452 * the handler was running. If all pending interrupts are handled, the
456 handle_edge_irq(unsigned int irq
, struct irq_desc
*desc
)
458 spin_lock(&desc
->lock
);
460 desc
->status
&= ~(IRQ_REPLAY
| IRQ_WAITING
);
463 * If we're currently running this IRQ, or its disabled,
464 * we shouldn't process the IRQ. Mark it pending, handle
465 * the necessary masking and go out
467 if (unlikely((desc
->status
& (IRQ_INPROGRESS
| IRQ_DISABLED
)) ||
469 desc
->status
|= (IRQ_PENDING
| IRQ_MASKED
);
470 mask_ack_irq(desc
, irq
);
474 kstat_irqs_this_cpu(desc
)++;
476 /* Start handling the irq */
477 desc
->chip
->ack(irq
);
479 /* Mark the IRQ currently in progress.*/
480 desc
->status
|= IRQ_INPROGRESS
;
483 struct irqaction
*action
= desc
->action
;
484 irqreturn_t action_ret
;
486 if (unlikely(!action
)) {
487 desc
->chip
->mask(irq
);
492 * When another irq arrived while we were handling
493 * one, we could have masked the irq.
494 * Renable it, if it was not disabled in meantime.
496 if (unlikely((desc
->status
&
497 (IRQ_PENDING
| IRQ_MASKED
| IRQ_DISABLED
)) ==
498 (IRQ_PENDING
| IRQ_MASKED
))) {
499 desc
->chip
->unmask(irq
);
500 desc
->status
&= ~IRQ_MASKED
;
503 desc
->status
&= ~IRQ_PENDING
;
504 spin_unlock(&desc
->lock
);
505 action_ret
= handle_IRQ_event(irq
, action
);
507 note_interrupt(irq
, desc
, action_ret
);
508 spin_lock(&desc
->lock
);
510 } while ((desc
->status
& (IRQ_PENDING
| IRQ_DISABLED
)) == IRQ_PENDING
);
512 desc
->status
&= ~IRQ_INPROGRESS
;
514 spin_unlock(&desc
->lock
);
518 * handle_percpu_IRQ - Per CPU local irq handler
519 * @irq: the interrupt number
520 * @desc: the interrupt description structure for this irq
522 * Per CPU interrupts on SMP machines without locking requirements
525 handle_percpu_irq(unsigned int irq
, struct irq_desc
*desc
)
527 irqreturn_t action_ret
;
529 kstat_irqs_this_cpu(desc
)++;
532 desc
->chip
->ack(irq
);
534 action_ret
= handle_IRQ_event(irq
, desc
->action
);
536 note_interrupt(irq
, desc
, action_ret
);
539 desc
->chip
->eoi(irq
);
543 __set_irq_handler(unsigned int irq
, irq_flow_handler_t handle
, int is_chained
,
546 struct irq_desc
*desc
;
549 if (irq
>= nr_irqs
) {
551 "Trying to install type control for IRQ%d\n", irq
);
555 desc
= irq_to_desc(irq
);
558 handle
= handle_bad_irq
;
559 else if (desc
->chip
== &no_irq_chip
) {
560 printk(KERN_WARNING
"Trying to install %sinterrupt handler "
561 "for IRQ%d\n", is_chained
? "chained " : "", irq
);
563 * Some ARM implementations install a handler for really dumb
564 * interrupt hardware without setting an irq_chip. This worked
565 * with the ARM no_irq_chip but the check in setup_irq would
566 * prevent us to setup the interrupt at all. Switch it to
567 * dummy_irq_chip for easy transition.
569 desc
->chip
= &dummy_irq_chip
;
572 spin_lock_irqsave(&desc
->lock
, flags
);
575 if (handle
== handle_bad_irq
) {
576 if (desc
->chip
!= &no_irq_chip
)
577 mask_ack_irq(desc
, irq
);
578 desc
->status
|= IRQ_DISABLED
;
581 desc
->handle_irq
= handle
;
584 if (handle
!= handle_bad_irq
&& is_chained
) {
585 desc
->status
&= ~IRQ_DISABLED
;
586 desc
->status
|= IRQ_NOREQUEST
| IRQ_NOPROBE
;
588 desc
->chip
->startup(irq
);
590 spin_unlock_irqrestore(&desc
->lock
, flags
);
594 set_irq_chip_and_handler(unsigned int irq
, struct irq_chip
*chip
,
595 irq_flow_handler_t handle
)
597 set_irq_chip(irq
, chip
);
598 __set_irq_handler(irq
, handle
, 0, NULL
);
602 set_irq_chip_and_handler_name(unsigned int irq
, struct irq_chip
*chip
,
603 irq_flow_handler_t handle
, const char *name
)
605 set_irq_chip(irq
, chip
);
606 __set_irq_handler(irq
, handle
, 0, name
);
609 void __init
set_irq_noprobe(unsigned int irq
)
611 struct irq_desc
*desc
;
614 if (irq
>= nr_irqs
) {
615 printk(KERN_ERR
"Trying to mark IRQ%d non-probeable\n", irq
);
620 desc
= irq_to_desc(irq
);
622 spin_lock_irqsave(&desc
->lock
, flags
);
623 desc
->status
|= IRQ_NOPROBE
;
624 spin_unlock_irqrestore(&desc
->lock
, flags
);
627 void __init
set_irq_probe(unsigned int irq
)
629 struct irq_desc
*desc
;
632 if (irq
>= nr_irqs
) {
633 printk(KERN_ERR
"Trying to mark IRQ%d probeable\n", irq
);
638 desc
= irq_to_desc(irq
);
640 spin_lock_irqsave(&desc
->lock
, flags
);
641 desc
->status
&= ~IRQ_NOPROBE
;
642 spin_unlock_irqrestore(&desc
->lock
, flags
);